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Helin, S., E. Arponen, J. Rajander, J. Aromaa, S. Johansson, and O. Solin. "Increased target volume and hydrogen content in [11C]CH4 production." Helmholtz-Zentrum Dresden - Rossendorf, 2015. http://nbn-resolving.de/urn:nbn:de:bsz:d120-qucosa-166344.
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Introduction
High starting radioactivity is usually advantageous for producing radiopharmaceuticals with high specific radioactivity. However, the [11C]CH4 yields from N2-H2 gas target fall short from theoretical amounts, as calculated from the cross section for the well-known 14N(p,α)11C nuclear reaction1. The beneficial effect of increased target chamber temperature on [11C]CH4 yields has recently been brought forward by us2 and others3. In addition to the temperature effect, our attention has also been on the hydrogen content factor.
This study intends to examine the N2-H2 target performance in a substantially larger target chamber and at higher temperatures than our setup before and compare the results to the existing data.
Materials and Methods
Aluminium bodied custom design target chamber is used in fixed 17 MeV proton beam irradiations. Target chamber is equipped with heating elements and cooling circuit for temperature control. In addition to the target chamber body temperature, the target gas loading pressure and irradiation current can be varied.
The irradiation product is collected into an ad-sorbent trap that was immersed in a liquid argon cooling bath within a dose calibrator.
Results and Conclusion
Pursued data will show [11C]CH4 saturation yields (Ysat [GBq/µA]) at different irradiation and target parameters.
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Rêgo, de Vasconcelos Bruna. "Phosphates-based catalysts for synthetic gas (syngas) production using CO2 and CH4." Thesis, Ecole nationale des Mines d'Albi-Carmaux, 2016. http://www.theses.fr/2016EMAC0004/document.
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Parmi les produits issus de la biomasse ou de la transformation des déchets organiques, le CO2 et le CH4 sont des intermédiaires chimiques importants qui ont de forts impacts environnementaux. En effet, ils sont les principaux gaz responsables de l'effet de serre et leur atténuation est un enjeu majeur. Une voie intéressante pour la valorisation de ces gaz est le reformage à sec du méthane (DRM), qui convertit le CO2 et le CH4 en gaz de synthèse (mélange d'hydrogène et de monoxyde de carbone). Ce mélange peut être utilisé pour plusieurs applications telles que la production de méthanol, d'éther diméthylique, d'hydrogène et des hydrocarbures liquides. Malgré cet intérêt, l'exploitation du DRM à l'échelle industrielle n'a pas encore vu le jour. La raison principale est la désactivation rapide des catalyseurs en raison des conditions sévères de fonctionnement du procédé (température élevée, dépôt de carbone). Cette thèse porte sur le développement de nouveaux catalyseurs à base de phosphate de calcium (CaP) dopés avec des métaux de transition pour la valorisation du CO2 et du CH4 en gaz de synthèse par DRM. Les CaP sont utilisés car ils possèdent des propriétés avantageuses en catalyse hétérogène comme la présence simultanée de sites acides et basiques, bonne stabilité thermique, large gamme de surface spécifique ... Dans un premier temps, des études sur les méthodes de synthèse de catalyseurs et sur la performance de différents métaux de transition (Zn, Fe, Co, Cu, Ni) ont été effectuées dans le but de sélectionner le catalyseur et sa méthode de préparation. Un réacteur à lit fixe capable de fonctionner à hautes température et pression a ensuite été testé pour un long temps de réaction afin d'évaluer correctement la performance des catalyseurs préparés. Ensuite, une étude paramétrique détaillée a été menée. L'influence des paramètres tels que le prétraitement des catalyseurs, la température (T = 400-700°C) et la pression (P = 1-25bar) de la réaction et les différents supports (hydroxyapatite, alumine) ont été étudiés. Enfin, la stabilité thermique et catalytique a été étudiée durant 300h de réaction. Les catalyseurs à base de CaP ont montré des rendements plus élevés en gaz de synthèse en comparaison aux catalyseurs commerciaux. Ces catalyseurs sont donc compétitifs dans les mêmes conditions opératoires (T = 700°C, P = 1bar, WHSV = 12272mLh-1gcat-1, t = 300h). Ce travail a montré l'intérêt des catalyseurs à base de CaP pour des processus à haute température, tel que le reformage à sec du méthane<br>Among the products resulting from biomass or organic waste transformation, CO2 and CH4 are important chemical intermediates. They also have a strong environmental impact since they are primarily responsible for the greenhouse effect and their mitigation is a key issue. An attractive way of valorization of such gases is the dry reforming of methane (DRM), which converts CO2 and CH4 into syngas (mixture of hydrogen and carbon monoxide). This mixture can be used for several applications, such as the production of methanol, dimethyl ether, hydrogen and liquid hydrocarbons. Despite such interest, the exploitation of DRM on industrial scale has not emerged yet. The main reason is the rapid deactivation of the catalysts due to the severe operating conditions of the process (high temperature, carbon deposition). This thesis focuses on the development of new catalysts based on calcium phosphate (CaP) doped with transition metals for the valorization of CO2 and CH4 through DRM. Actually,CaP has advantageous properties in heterogeneous catalysis, as the simultaneous presence of acid and basic sites, good thermal stability, and wide range of surface area... Initially, a study on the catalyst synthesis methods and an investigation of the performance of different transition metals (Zn, Fe, Co, Cu, Ni) were carried out in order to select the catalyst system and the preparation method. Secondly, a fixed-bed reactor capable of operating at high temperature and pressure and for log time on stream was built and implemented during this work in order to properly evaluate the performance of the preparedcatalysts. Then, a detailed parametric study was conducted. The influence of parameters such as catalyst pre-treatment, temperature (T = 400-700°C) and pressure (P = 1-25bar) of the reaction and support (hydroxyapatite, alumina-based supports) were investigated. Finally, the catalytic stability was studied for 300h of time on stream (TOS). The CaP catalysts showing higher yields on syngas were compared to commercial catalysts. Our catalysts showed to be competitive in the same operating conditions (T = 700°C, P = 1bar, WHSV = 12272mLh-1gcat-1,TOS = 300h). This work shows the interest of CaP catalysts for high temperature process, such as dry reforming of methane
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GOMEZ, CAMACHO CARLOS ENRIQUE. "Enhancement of bioenergy production (H2 + CH4) from organic waste in anaerobic fermentation processes." Doctoral thesis, Politecnico di Torino, 2019. http://hdl.handle.net/11583/2738393.
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YAMASHITA, Hiroshi. "Numerical Study on NOx Production of Transitional Fuel Jet Diffusion Flame." The Japan Society of Mechanical Engineers, 2000. http://hdl.handle.net/2237/8999.
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Gregoire, Manon. "Valorisation catalytique du CO2 via l’hydrogénation pour la production de méthane." Electronic Thesis or Diss., Littoral, 2024. http://www.theses.fr/2024DUNK0713.
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Cette étude porte sur la valorisation du CO2 par le procédé de méthanation. Elle vise à développer des matériaux catalytiques efficaces et stables pour cette réaction. L’espèce active utilisée dans différentes familles de matériaux sera le nickel. Dans un premier temps, nous avons focalisé notre travail sur des catalyseurs au nickel supporté sur différentes silices afin d’étudier l’influence de la taille des particules. Le premier, Ni/SiO2 est le catalyseur classiquement utilisé de Ni sur de la silice commerciale avec des tailles de particules métalliques d’environ 12 nm assez élevées et situées principalement à l’extérieur de la silice. Le second, Ni/IWI, possède des NPs de Ni confinées dans les mésopores de la SBA-15 avec une taille moyenne de 9 nm. Le troisième, Ni/MIA, avec des NPs de Ni confinées dans les micropores de la SBA-15 et une taille moyenne de 3 nm. Les meilleures performances catalytiques sont obtenues avec le catalyseur Ni/MIA avec un rendement maximal de 86 % à 430 °C. Il offre donc un grand potentiel d'utilisation en raison de sa capacité à résister au frittage dû au confinement des nanoparticules de Ni. Ensuite, une série de x%Ni/Phyllo (avec x = 5 %, 10 %, 20 % et 40 % de Ni) a été synthétisée afin d’étudier l’influence de la teneur en Ni. Les tests catalytiques ont montré que 20%Ni/Phyllo avait des activités catalytiques intéressantes. Afin d’étudier l’influence de la température de réduction des phyllosilicates sur la réaction de méthanation, ce matériau a été réduit à plusieurs températures et c’est la réduction à 800 °C qui a permis de meilleures performances catalytiques, avec un rendement en CH4 de 91 % à 375 °C. De plus, le matériau n’a montré aucune désactivation après 48 h. Par la suite, la composition gazeuse et la durée de réduction ont été étudiées sur des matériaux réduits à plus basses températures. Cependant, les résultats n’ont pas été concluants. Enfin, plusieurs séries de pérovskites, qui ont un grand nombre de propriétés intéressantes pour la réaction de méthanation, ont été synthétisées à partir de LaNiO3, en modifiant les cations A et B et la stœchiométrie du lanthane. Le cation B offrant les meilleures performances catalytiques est le nickel et la stœchiométrie idéal pour le lanthane est 0,9. En revanche, la substitution du cation A par d’autres éléments alcalino-terreux, comme le strontium et le calcium, peut être bénéfique (80 % à 330 °C pour La0,9Sr0,1NiO3). Pour finir le cation A a été substitué totalement et le calcium offre des résultats prometteurs avec un rendement en CH4 de 89 % à 300 °C grâce à la présence de carbonates<br>This study focuses on the recovery of CO2 by the methanation process. It aims to develop efficient and stable catalytic materials for this reaction. First, we focused our work on nickel catalysts supported on different silicas in order to study the influence of particle size. The first, Ni/SiO2 is the conventionally used nickel catalyst on commercial silica with metal particle sizes of about 12 nm quite high and located mainly outside the silica. The second, Ni/IWI, has Ni NPs confined in the mesopores of SBA-15 with an average size of 9 nm. The third, Ni/MIA, with NI NPs confined in the micropores of SBA-15 and an average size of 3 nm. The best catalytic performance is achieved with the Ni/MIA catalyst with a maximum efficiency of 86 % at 430 °C. It therefore offers great potential for use due to its ability to resist sintering due to the confinement of Ni nanoparticles. Then, a series of x%Ni/Phyllo (with x = 5 %, 10 %, 20 % and 40 % nickel) was synthesized in order to study the influence of Ni content. Catalytic tests showed that 20%Ni/Phyllo had interesting catalytic activities. In order to study the influence of the phyllosilicate reduction temperature on the methanation reaction, this material was reduced to several temperatures and it was the reduction to 800 °C that allowed better catalytic performance, with a CH4 yield of 92 % at 350 °C. Post-test characterizations do not show particle sintering or carbon formation on the surface of the materials. In addition, the material showed no deactivation after 48 hours. Subsequently, the gaseous composition and reduction duration were studied on reduced materials at lower temperatures in order to approximate the performance of a reduced material at 800 °C. However, the results were inconclusive. Finally, several series of perovskites have been synthesized. Indeed, these materials offer a large number of interesting properties for the methanation reaction. A number of perovskites have been synthesized from LaNiO3, completely or partially modifying the A and B cations and modifying the lanthanum stoichiometry. The B cation with the best catalytic performance is nickel and the ideal stoichiometry for lanthanum is 0.9. On the other hand, substituting the A cation with other alkaline earth elements may be beneficial. Indeed, strontium, sodium and calcium increase the catalytic performance up to 80 % at 330 °C for La0.9Sr0.1NiO3. Finally, cation A has been completely substituted and calcium offers promising results thanks to the presence of carbonates. It has therefore been calcined at a lower temperature in order to promote the formation of carbonates and allows a CH4 yield of 89 % at 300 °C
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Chhajed, Pawan. "Diffusion Characterization of Coal for Enhanced Coalbed Methane Production." OpenSIUC, 2011. https://opensiuc.lib.siu.edu/theses/645.
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This thesis explores the concept of displacement of sorbed methane and enhancement of methane recovery by injection of CO2 into coal, while sequestering CO2. The objective of this study was to investigate the diffusion behavior of San Juan Basin coal under single and competitive gas environments. The movement of gas in a coalbed reservoir starts in the coal matrix with diffusion towards the naturally occurring cleat network surrounding the matrix blocks. The gas production potential from coalbed reservoirs under different gas environments was, therefore, estimated by studying the diffusion behavior of the coal type. The results clearly showed that the rate of diffusion increases with decreasing reservoir pressure, the increase being exponential at low/very low pressure. As a final step, a simulation study was carried out using the experimental results to predict long-term gas production from coalbed reservoirs with and without CO2 injection. This was followed by a preliminary economic analysis in order to estimate the feasibility of enhanced recovery method by CO2 injection by calculating the net present value of a project with and without carbon credits. The results showed that it is possible to obtain significant improvement in methane recovery by CO2 injection. However, it becomes economically feasible only with carbon credits.
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Hao, Yushan. "Characterization of Peat Bog CO2 and CH4 Production Potentials in relation to Peat Physico-chemical Properties and Vegetation Composition." The Ohio State University, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=osu1562338709421684.
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Filho, Adibe Luiz Abdalla. "Produção de gases, síntese microbiana pelo radiofósforo e digestibilidade do babaçu e mofumbo em dietas de ovinos." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/64/64133/tde-05052015-094343/.
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Quando a escassez de alimentos em pastagens naturais compromete a alimentação animal, os pequenos ruminantes podem incorporar em suas dietas as folhas de outras plantas, como árvores e arbustos, muitas delas ricas em metabólitos secundários como taninos e que ainda carecem de estudos acerca de seus efeitos na produtividade animal. Com o objetivo de verificar a possibilidade de utilização das folhas de Orbignya phalerata (Babaçu) e Combretum leprosum (Mofumbo) na alimentação e avaliar o efeito da inclusão na produção de ovinos, dois estudos foram conduzidos no Laboratório de Nutrição Animal do Centro de Energia Nuclear na Agricultura da Universidade de São Paulo, Piracicaba (LANA/CENA-USP). Um primeiro estudo avaliou as variáveis de desempenho, parâmetros bioquímicos e hematológicos, estimativas de síntese de proteína microbiana, digestibilidade aparente dos nutrientes e produção entérica de metano (CH4) dos animais. O segundo estudo avaliou as características de carcaça, coloração e perfil de ácidos graxos da carne dos ovinos machos utilizados no primeiro estudo. Os tratamentos experimentais testados foram dietas, com relação concentrado:volumoso de 50:50, elaboradas com base na utilização das folhas das plantas como substituição de 30 % do feno de Cynodon dactylon (Tifton-85), resultando em três tratamentos: Controle (sem substituição do feno), Babaçu e Mofumbo. No primeiro estudo, foram utilizados 24 ovinos Santa Inês, em um delineamento experimental casualizado com oito repetições para cada tratamento e 48 dias de período experimental avaliando o desempenho dos ovinos. Também nesse período, um ensaio in vitro de síntese de proteína microbiana foi realizado utilizando o radiofósforo em cinco inóculos de cada tratamento. Após o experimento de desempenho, durante nove dias, seis animais de cada tratamento foram alocados em gaiolas metabólicas para a determinação da digestibilidade aparente dos nutrientes, a síntese de proteína microbiana e o balanço de nitrogênio. Simultaneamente foi quantificada a produção de CH4 entérico in vivo. Os ovinos do tratamento Controle apresentaram maior (P < 0,05) digestibilidade aparente da fibra em detergente ácido. A produção entérica de CH4 dos ovinos do tratamento Mofumbo não diferiu do tratamento Controle e foi menor (P < 0,05) que a dos ovinos do tratamento Babaçu. No segundo estudo, os cinco animais machos de cada tratamento foram encaminhados para abate e procedeu-se a avaliação da carcaça, dos componentes não carcaça e a coloração e perfil de ácidos graxos na carne. Não foram observadas diferenças (P > 0,10) nos resultados da avaliação da carcaça, dos componentes não carcaça, coloração e total de ácidos graxos. O tratamento Mofumbo apresentou maiores (P < 0,10) valores da estimativa de atividade da enzima ?9-dessaturase C16. Efeito linear significativo (P = 0,01) foi observado quando se analisou a estimativa de atividade da enzima ?9-dessaturase C18 e os teores de TC nas dietas. A inclusão das folhas do Babaçu e Mofumbo não apresentou efeitos deletérios à saúde dos animais, não comprometeu o desempenho, potencial de produção e qualidade da carne dos ovinos, tendo o Mofumbo inclusive apresentado potencial mitigador de CH4, indicando que podem ser utilizadas como ingredientes na composição de dietas para ovinos<br>When food shortages in natural pastures is committed to animal nutrition, small ruminants can incorporate into their diets the leaves of other plants, such as trees and shrubs, many of them rich in secondary metabolites such as tannins and which still lack of studies about its effect on animal productivity. In order to verify the possibility of using leaves of Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) in feed and to evaluate the effect of their inclusion in the sheep production system, two studies were conducted at the Animal Nutrition Laboratory of Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba (LANA/CENA-USP). The first study evaluated the performance variables, biochemical and hematological parameters and also determined the microbial protein synthesis, nutrient apparent digestibility and enteric production of methane (CH4). The second study assessed the carcass characteristics, fatty acid profile and meat color of male sheep used in the first study. The experimental treatments were diets with forages to concentrate rate of 50:50, drawn up on the basis of using the leaves of the experimental plants replacing 30% of the Cynodon dactylon (Tifton-85) hay, resulting in three treatments: Control (no hay replacement), Babassu and Mofumbo. In the first study, there were used 24 Santa Inês sheep, in a randomized experimental design with eight repetitions for each treatment and 48 days of trial period. Also during this period, an in vitro microbial protein synthesis was performed using the radio phosphorus using five different inocula of each studied treatment. After this period, for nine days, six animals from each treatment were allocated in metabolic cages for determining the nutrient apparent digestibility, microbial protein synthesis and nitrogen balance. Simultaneously it was quantified the enteric CH4 production in vivo. The Control group showed greater (P < 0.05) apparent digestibility of acid detergent fiber. Enteric CH4 production of sheep fed with Mofumbo leaves did not differ from the Control group but was lower (P < 0.05) than the sheep fed Babassu leaves. In the second study, the five male animals of each treatment were sent to slaughter and to precede the assessment of carcass, not carcass components and color and fatty acid profile in the meat. The results of the assessment of carcass, not carcass components, color and overall fatty acids showed no differences between the treatments. Mofumbo treated sheep showed greater (P < 0.10) values of the ?9-desaturase C16 enzyme activity. Significant linear effect (P = 0.01) was observed when it analyzed the enzyme activity estimation ?9-desaturase C18 and TC levels in the diets. The inclusion of Babassu and Mofumbo leaves shown no negative effects on animal health, did not compromise the performance, production potencial or meat quality of the animals, having Mofumbo also presented CH4 mitigating potencial, indicating that those plants can be used as ingredients in the composition of sheep diets
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Wei, Tzu-Hsiang Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Transient production of biopharmaceutical proteins." Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2009. http://handle.unsw.edu.au/1959.4/43708.
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The creation of stable mammalian cell lines for biopharmaceutical production often require several months, and is unfavourable for the rapid production of multiple drug candidates for screening in the early stages of development. Biopharmaceutical production by transient transfection provides a possible alternative of quickly producing these early stage drug candidates. The Epi-CHO transient expression system, which consists of a Chinese hamster ovary (CHO) cell line (CHO-T) expressing the murine polyomavirus Large T-Antigen (LT), emonstrated enhanced transient recombinant protein production. The aim of this study was to prolong transient recombinant protein prod.Jction of the Epi-CHO expression system by creating a CHO cell line expressing both LT and EBNA1 (ECHO-T). The pEBNA1-LT expression vector encoding LT and EBNA1 was constructed and transfected into CHO-K1. A total of 20 clones were isolated from the antibioticresistant pool and screened for the expression of functional LT and EBNA1. PCR analysis showed 16 of the 20 clones was positive for EBNA1 and LT DNA. Of the 16 clones, six were positive for EBNA1 and LT expression by RT-PCR. Detection of LT and EBNA1 by immunofluorescence showed positive staining for the P7-G3 clone. Western blotting suggested the P7-G3 clone was: positive for EBNA1, and clones P3-C7 and P7-E2 were positive for LT. A plasmid replication assay confirmed the expression of functional LT in all six clones. Plasmid maintenance assay confirmed clone P7-G3 as the ECHO-T clones to express functional EBNA1. The P7-G3 clone demonstrated prolonged and sustained transient recombinant protein expression when compared to CHO-T. The P7-G3 clone achieved sustained transient protein expression for 32 days in the absence of selection, the longest currently reported for CHO cells.
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Kunaparaju, Raj Kumar Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Epi-CHO, an episomal expression system for recombinant protein production in CHO cells." Publisher:University of New South Wales. Biotechnology & Biomolecular Sciences, 2008. http://handle.unsw.edu.au/1959.4/41499.
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The current project is to develop a transient expression system for Chinese Hamster Ovary (CHO) cells based on autonomous replication and retention of plasmid DNA. The expression system, named Epi-CHO comprises (1) a recombinant CHO-K1 cell line encoding the Polyoma (Py) virus large T-Antigen (PyLT-Ag), and (2) a DNA expression vector, pPy/EBV encoding the Py Origin (PyOri) for autonomous replication and encoding the Epstein-Barr virus (EBV), Nuclear Antigen-1 (EBNA-1) and EBV Origin of replication (OriP) for plasmid retention. The CHO-K1 cell line expressing PyLT-Ag, named CHO-T was adapted to suspension growth in serum-free media (EXCELL-302) to facilitate large scale transient transfection and recombinant (r) protein production. PyLT-Ag-expressed in CHO-T supported replication of PyOri-containing plasmids and enhanced growth and r- protein production. A scalable cationic lipid based transfection was optimised for CHO-T cells using LipofectAMINE-2000??. Destabilised Enhanced Green Fluorescence Protein (D2EGFP) and Human Growth Hormone (HGH) were used as reporter proteins to demonstrate transgene expression and productivity. Transfection of CHO-T cells with the vector pPy/EBV encoding D2EGFP showed prolonged and enhanced EGFP expression, and transfection with pPy/EBV encoding HGH resulted in a final concentration of 75 mg/L of HGH in culture supernatant 11 days following transfection.
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Lima, e. Castro Paula Maria. "Optimisation of CHO cell growth and recombinant interferon-γ production". Thesis, University College London (University of London), 1993. http://discovery.ucl.ac.uk/1317969/.
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The optimisation of recombinant protein production by animal cell cultures is important for the economic feasibility of these processes. Simultaneously with product yield, product authenticity is a crucial aspect to consider as it may per se affect the therapeutic value of such proteins. More defined culture media are being developed, particularly to ensure batch product consistency. A Chinese Hamster Ovary cell line (CHO 320) producing human interferon-γ (IFN-γ), a glycosylated protein, was chosen to investigate the effects of the culture environment on (I) cell growth, (2) product yield and (3) product authenticity. A statistical approach was used to identify important culture components for cell growth and IFN-γ production. When the concentration of the resulting positive variables was initially increased in culture, improvements of approximately 40% in both of these parameters were achieved; the glycosylation of IFN-γ was not affected. The former analysis also indicated that different stimuli were required for growth and production. Fed-batch feeding of glucose and glutamine, components depleted early from culture, did not prolong cell growth or IFN-γ production but the initial glycosylation pattern of IFN-γ was a function of glutamine concentration. Bovine serum albumin (BSA) was shown to have important role(s) in culture and cell growth was not possible in its absence. Pluronic F68, alone or in combination with a lipid mixture or linoleic acid, was able to restore cell growth in low BSA (1 mg/ml) cultures. However, IFN-γ production was significantly reduced and the extent of IFN-γ glycosylation also changed. These effects were related to: (1) BSA concentration, (2) BSA type, and ultimately, (3) lipid composition of the culture. The results reported in this thesis exhibit the necessity to consider the effects of the culture environment not only on cell growth and product yield but also on product authenticity throughout any optimisation process.
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Akin, Ilina V. "Measurement Of The Cross Section Ratio Chi-c2/chi-c1 For Prompt Chi-c Production With Cms Experiment." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614979/index.pdf.
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The prompt production of &chi<br>c quarkonia is studied in proton-proton collisions at 7 TeV, using
data collected by CMS in 2011 corresponding to an integrated luminosity of 4.6 fb
&minus<br>1. The
&chi<br>c mesons are reconstructed through their radiative decays to J/&psi<br>and photon with J/&psi<br>&rarr<br>&mu<br>+&mu<br>&minus<br>. The photons are reconstructed through their conversion in electron-positron pairs in
the tracking detector which gives a mass resolution sufficient for resolving these states. The
ratio of the prompt production cross sections for the &chi<br>c1 and &chi<br>c2 states, &sigma<br>(&chi<br>c2)/&sigma<br>(&chi<br>c1), has
been determined as a function of the J/&psi<br>transverse momentum between 7 and 25 GeV/c.
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Lemoigne, Yves. "Hadro-production d'états CHI du charmonium auprès du SPS." Paris 11, 1987. http://www.theses.fr/1987PA112333.
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L’observation d’états CHI du charmonium en hadro-production, nécessite une résolution très fine pour séparer des états de masses très proches (45 MeV entre deux états CHI de masse supérieure à 3510 MeV). L’expérience WA11 a pu séparer les états CHI(3510) et CHI(3555), mesurer leur section efficace en production π – bérylium à 185 GeV / c et chiffrer la contribution de ces états à la production du J /ψ (17,7 % et 12,8 % ). L’étude détaillée qui a été menée sur les événements CHI(3555) n’est pratiquement produit que par fusion gluon – gluon, alors que le CHI(3510) est issu également des fusions quark – antiquark légers et gluon – gluon. Il se trouve que les différents graphes envisageables, tant en conservation de couleur qu’en évaporation de couleur, semblent contribuer à la production d’états de charmonium, dans des rapports simples donnés par des règles de comptage (∝s², ∝s³,…etc. ). A partir de nos données, à 185 GeV /c, et en utilisant des fonctions de structure usuelles (par exemple, celles de DUKE – OWENS), on peut alors calculer les caractéristiques de la π – production des J/ψ, des CHI ₁ et des CHI ₂, à d’autres énergies du S. P. S… Ces calculs donnent des résultats comparables aux observations des groupes « Ω » (pour le J/ψ) et « GAMS » (pour les CHI) réalisées vers 40 GeV/c<br>The observation of hadroproduced charmonium CHI states requires a good resolution to disentangle states of similar masses (45 MeV of difference for masses larger than 3500 MeV). The WA11 experiment was able to distinguish the two CHI (3510) and CHI(3555) states, measure their cross – sections in π – beryllium at 185 GeV/c and give a ratio of contribution of this to J /ψ production (17,7 % and 12,8 % respectively). A refined analysis of CHI – states events has shown different processes the π – production of these states. At 185 GeV/c, the CHI (3555) comes mainly from gluon – gluon fusion, but the x(3510) is equally produced by quark – antiquark fusion and gluon – gluon fusion. One finds that different graphs can be envisaged, both in colour conservation as well as in colour evaporation, to contribute to charmonium state production given by simple counting rules (∝s², ∝s³,…etc. ). Using our data at 185 GeV/c and the usual structure function (like the DUKE – OWEN’s ones), we are able to compute the J/ ψ, CHI₁ and CHI ² π – production at any other S. P. S. Energy. This calculation gives values in agreement with results from the « Ω » group (for CHI), at GeV/c
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Connolly, Helen. "The formation of halocarbons by marine organisms." Thesis, Bangor University, 1990. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.280676.
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Szula, Ewa. "Metabolic profiling and imaging of CHO cells for fusion protein production." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/metabolic-profiling-and-imaging-of-cho-cells-for-fusion-protein-production(ec83142c-0d97-437e-8d0f-d767887bcde5).html.
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Fc-fusion proteins (e.g. EPO-Fc) are the most often created fusion proteins due to their beneficial biological and pharmacological properties. The economic success of Fc-fusion proteins and other biopharmaceuticals production however, greatly depends on a robust, low-cost and highly effective protein mammalian cell extraction system . Understanding of how cells respond to a protein production environment based on metabolic profiles provides new goals for bioengineering of cell lines for best performance in biomanufacturing. Furthermore, insights on how individual cell metabolism and therefore phenotype, respond to cell microenvironment allows the underlying biological mechanisms to be explored in greater detail. This study focused on the application of mass spectrometry (MS) technologies, combining the analysis of metabolic profiles of cells extracts by GC-MS and MALDI-MS and spatial visualisation and distribution of metabolites within cells producing the fusion protein by MALDI-MSI and SIMS imaging. The analysis of external and internal metabolome profiles of cells producing the protein showed an extended effect of EPO-Fc fusion protein production on cell metabolism. The findings indicate that changes observed in EPO-Fc producing cells are related to enhanced protein and lipid synthesis highlighting that these cells are in a state of increased metabolic activity with the protein exocytosis into growth medium. Moreover, the composition of lipid bilayer of induced cells seemed to be different to non-induced cells. These findings were confirmed with the analysis of EPO-Fc induced cells using MS metabolic imaging. Multivariate analysis highlighted a number of metabolites that were significantly influenced by the protein expression when compared to control cells. The major metabolic changes in induced cells were those related to lipid metabolism. The information about metabolic changes in tetracycline-induced cells obtained from the analysis of cell populations was further supported with the analysis based on single-cell studies. Single-cell based studies also proved that investigations of individual cells provide additional insights about changes in metabolism of induced cells that can be referred to a unique, single cell and its phenotype. The analysis of CHO cells revealed a high level of heterogeneity within a cell population. Different cell phenotype and hence, metabolite content allowed for correlation between cell locations and their metabolite characteristics, specific for each type of cells. This project has successfully shown combination of bio-analytical techniques to investigate external and internal metabolome changes related to a fusion protein production in mammalian cells. Additionally, the significance of single cell approaches in metabolomics has also been highlighted, providing insights into the sub-cellular distribution of metabolites in cells producing EPO-Fc and information on the level of heterogeneity within a cell population. A multidimensional approach for metabolic profiling and future technological improvements of single-cell platforms are required to provide improved data acquisition and data analysis in order to better understand unknown processes involved in cell metabolism.
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Yang, Ming. "Ammonia effects on CHO cell growth, metabolism, erythropoietin production and glycosylation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/NQ56157.pdf.
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Hanson, Eleanor. "The epigenetics (histone PTMs) of therapeutic protein production in CHO cells." Thesis, University of Sheffield, 2019. http://etheses.whiterose.ac.uk/22945/.
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Chinese hamster ovary (CHO) cells are an important host cell system for the manufacturing of biopharmaceuticals. Epigenetics have been shown to have an important role in controlling gene expression in CHO cells, and thus affect the rate of protein production. It is hoped that by understanding the role of epigenetics in CHO cells improvements can be made in the production of biopharmaceuticals. In this work we have studied how histone PTMs differ between cell lines and throughout culture. These changes have then been correlated with growth rate, cell size and specific productivity. Mass spectrometry (MS) has been used as an unbiased quantitative technique to study how histone PTMs differ between four cell lines and throughout cell culture. The data generated in this study is the first global analysis of histone PTMs in CHO cells to date. The relative abundances of histone PTM were compared across different CHO-S and CHO-K1 cell lines with different productivities. Similar patterns of histone PTMs were observed. The most abundant modifications identified included H3K9me3, H4K20me2 and H3K27me1. Furthermore the results show no significant differences between different clones within a lineage, but the abundance of H3K23ac differed between lineages. In addition, the relative abundances of histone PTM for the different cell lines were compared throughout batch culture. Over 20 proteoforms were identified having different abundances at different stages of culture. The most prominent change was on H4K20 where methylation was progressive. The majority of the modifications that changed were associated with quiescence such as H3K9me3K14ac and H3K27me3 which increased through culture. Given that changes occurred through culture these were then correlated with the cellular phenotypes of growth rate, cell size and specific productivity. H3K27me3 and acetylation of H4 which correlated with growth rate were identified as possible engineering targets. Finally alterations to the epigenetic profile of CHO cells were made by small molecule inhibitors targeting methyltransferases and Histone deacetylases with the aim of improving specific productivity and growth rates of CHO cells. The results showed that addition of the small molecules inhibitors affected the growth rate through altering the epigenetic profile but in an unpredictable manner as multiple modification need to be altered to successfully alter the phenotype.
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Maria, Sophie. "Développement d'un bioprocédé continu couplant la production et la purification d'un anticorps recombinant." Thesis, Bordeaux, 2017. http://www.theses.fr/2017BORD0898/document.
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Les anticorps monoclonaux sont une classe de bio médicaments en plein essor. Leur production est largement étudiée afin d’obtenir des rendements de plus en plus élevés et de réduire les coûts. Cette thèse décrit le développement d’un procédé complet en continu, de la production d’anticorps recombinants par des cellules mammifères jusqu’à leur purification. L’objectif est de coupler la culture cellulaire en mode perfusion à la purification par chromatographie semi-continue. Le développement du procédé se fait en bioréacteur avec une lignée de cellules d’ovaires de hamster chinois (CHO-DP12) transformée pour produire un anticorps anti-Interleukine 8 utilisée, comme modèle. Après adaptation, les cellules ont été cultivées en mode batch afin de connaitre le comportement de la lignée en environnement contrôlé. Ensuite, un procédé de perfusion de 2L de culture avec recyclage cellulaire a été mis en place. Le principal enjeu est de maintenir un état stationnaire avec une concentration cellulaire constante et déterminer le débit optimal d’alimentation spécifique par cellule (CSPR). Plusieurs méthodes ont été testées et comparées pour la détermination de ce CSPR optimal. Le procédé de culture en perfusion a ensuite été maintenu pendant 24 jours à des concentrations cellulaires de 10, 20 et 40 millions de cellules par mililitres. Les anticorps produit par différents modes de culture ont été caractérisés (batch, fed-batch et perfusion). Les N-glycosylations, les variants de charge ainsi que la thermo-stabilité des anticorps ont été étudiés. Les résultats montrent que les anticorps produits présentent des caractéristiques similaires quel que soit le mode de production.Pour la purification, une étude préliminaire a permis de caractériser le comportement du filtrat sur la résine chromatographique d’affinité MabSelect Sure LX en chromatographie classique. Un procédé semi-continu a été simulé grâce au logiciel BioSC® Predict puis testé et optimisé sur le chromatographe BioSC®. Il comprend la purification de l’anticorps mais aussi les étapes de nettoyages et de sanitisation. Un premier essai de couplage production/purification a pu être réalisé avec succès pendant 32h et a permis d’obtenir un niveau de pureté similaire à la chromatographie classique. La productivité a été augmentée de 23% (en grammes d’anticorps purifié par litre de résine et par jour) et le volume de tampon utilisé a été réduit de 25%. De plus, le couplage production/purification a permis de s’affranchir du stockage de volumes importants de filtrat (7,2L de filtrat par jour de production en perfusion). Enfin, une étude de coût de production, à l’échelle « laboratoire », a été réalisée afin de déterminer, en fonction de la productivité du clone et de la quantité d’anticorps à produire, la différence de rentabilité entre une production en batch ou en perfusion à différents CSPR<br>Monoclonal antibodies are a biopharmaceuticals class of growing interest. Their production is widely studied to obtain higher yields and to reduce costs. This thesis describes the development of a complete continuous process, from the production of recombinant antibodies by mammalian cells until their purification. The objective is to connect cell culture in perfusion mode to a semi-continuous chromatographic purification. The development of the process was done in a bioreactor with a Chinese hamster ovary cell line (CHO-DP12) transformed to produce an anti-interleukin-8 antibody used as a cell model. After adaptation, the cells were cultured in batch mode in order to study the behavior of the cell line in controlled environment. Then, a 2L culture perfusion process with cell recycling was set up. The main challenge is to maintain a steady state with constant cell concentration and to determine the optimal cell-specific perfusion rate (CSPR). Several methods were tested and compared for the determination of this optimal CSPR. The perfusion process was maintained for 24 days at cell concentrations of 10, 20 and 40 million cells per mililiters. The antibody produced by different culture methods was compared (batch, fed-batch and perfusion). The N-glycosylations, the charge variants as well as the thermo-stability of the antibody were studied. The results show that the produced antibody have similar characteristics whatever the chosen production mode. For purification process, we performed a preliminary study to characterize the behavior of the supernatant on the chromatographic affinity resin MabSelect Sure LX. A semi-continuous process was simulated through BioSC® Predict software and then tested and optimized on the BioSC® chromatograph. It includes antibody purification but also cleaning and sanitizing steps. A first production/purification coupling test was successfully carried out for 32 h. It provides antibodies at a purity level similar to that of the conventional chromatography. Productivity was increased by 23% (in grams of purified antibody per liter of resin per day) and the volume of buffer used was reduced by 25%. In addition, production/purification coupling prevented storage of large volumes of supernatant (7,2L of supernatant per production day in perfusion mode). Finally, a cost-of-production study, at research scale, was carried out to determine, depending on the productivity of the clone and the antibodies amount, the difference of costs between batch or perfusion production according to different CSPRs
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Porncharoennop, Chompoonuth. "Metabolite profiling associated with productive recombinant CHO cell culture." Thesis, University of Manchester, 2017. https://www.research.manchester.ac.uk/portal/en/theses/metabolite-profiling-associated-with-productive-recombinant-cho-cell-culture(3bb6bdaf-d8dc-4249-b77b-159e9e77307a).html.
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A positive correlation between the flux of TCA cycle and productivity of Chinese Hamster Ovary (CHO) cells has been reported. Earlier work in this laboratory revealed that supplementation with nutrients that enter the TCA cycle (combination of glucose (Glc), pyruvate (Py), aspartate (Asp), asparagine (Asn) and glutamate (Glu)) significantly increased maximum viable cell density and antibody production of recombinant CHO cells. Increased amounts of extracellular citrate was associated with feeding conditions. It was hypothesized that increased flux through the TCA cycle and related metabolism was linked to enhanced growth and/or productivity of CHO cells. Therefore, the aim of this thesis is to clarify these relationships to provide routes to improve the efficiency of CHO cells by nutrient supplementation and metabolic engineering. The relationship between growth, antibody production and metabolite profiles of CHO-LB01 cells was examined in response to individual supplementation with Asn, Asp, Glu, Py and β-hydroxybutyrate (HB). Feeding HB significantly increased antibody titre while Asn feeding increased maximum cell density but led to earlier cell death. Both nutrients increased the amounts of TCA cycle intermediates and decreased the amounts of lactate, glycerol, sorbitol and amino acids. Moreover, oxygen consumption rate was increased in the presence of Asn or HB. This finding inferred that increased production of the TCA cycle intermediates in cells fed Asn or HB correlated with enhanced flux of the TCA cycle leading to enhanced oxidative metabolism. Combination of Asn or HB with Glc further improved cell growth, increased antibody titre and enhanced metabolic responses to feeds (TCA cycle intermediates). Based on these results, inhibition of sorbitol production using chemical reagent (EPBC) and siRNA designed against Akr1b1 and overexpression of malate dehydrogenase II (MDH II) were undertaken in order to increased flow of carbon atoms to TCA cycle and/or increased flux in the TCA cycle, respectively. Inhibition of sorbitol production was achieved in the presence of EBPC but there was no improvement of cell culture performance and accumulation of TCA cycle intermediates remained the same. CHO cells transfected with exogenous Mdh2 did not show improved cell culture performance. Whilst stable clones exhibited variable MDH II expression at protein level (and antibody titre), overexpression of exogenous MDH II could not be confirmed by Western blot. One CHO-MDH II clone showed greater antibody titre and exhibited similar metabolite profiling with cells fed Asn or HB. This contrasted to the majority of clones that were low producers. Comparison by RNA-Seq transcriptomic profiling of high- and low-producing CHO-MDH II clones showed that the majority of differentially expressed genes were genes related to cytoskeleton-related element and cell signaling pathways. Overall, these results confirmed the relationship between increased the amount of TCA cycle intermediates and increased antibody production. Increased amount of TCA cycle intermediates could result in increased the flow of TCA cycle lead to enhance energy and antibody production. In addition, this work represents the first study on addition of HB offers a simple effective strategy to increase antibody production.
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Ottosson, Anton. "Integration of Hydrogen Production via Water Electrolysis at a CHP Plant : A feasibility study." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-83717.
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Hydrogen gas (H2), that is not produced from fossil oil or natural gas, is expected to become a cornerstone in the energy transition strategy in Europe. The recent years, technological and economic advances in the electrolyzer area, along with political and corporate support, have put H2 at the forefront of many countries’ climate change agenda. Consequently, green H2 is poised to play a large role in the coming energy transition to combat climate change. The possible advantages of integrating H2 production with a combined heat and power plant, or CHP, is investigated in this study. More precisely, the water electrolysis is carried out based on the purified flue gas condensate water and excess heat is recovered as district heating. A comparison of today’s three most common electrolyzer technologies was made, where Proton Exchange Membrane, or PEM, technology was chosen for this project, mainly for its high purity of H2 gas, robust construction, and the ability to run it as a fuel cell. Based on a mass and energy balance, a model including the integration of a PEM with a generic CHP plant was developed. The model was made modifiable, making it possible to change governing parameters, to be able to investigate different possible scenarios. Production flows, losses and other relevant data was calculated from the model. Operational data for the PEM electrolyzer were collected from several manufacturers where a mean value of the data was used as a base-case for the calculations. Based on literature and consulting experts, several assumptions were made, for example the selling price of H2 and the price for electricity. From the base-case were two cases made: a linear and non-linear case. The linear case uses the same input data each year for 20 years, while the non-linear case uses a changing input data each year for 20 years. Calculations were based on an electrolyzer size of 1,4 MW, where auxiliary equipment consumed additional 0,04 MW, resulting in a total energy consumption of 1,44 MW. An operational temperature of 80°C was assumed along with an operational pressure of 5 and 30 bar for the anode and cathode respectively. This resulted in an H2 production flow of 26 kg/h, a process water requirement of 0,2 m3/h, and a possible heat recovery amount of 0,34 MWh with a relevant temperature for the use in district heating. The study shows that the condensate-water at E.ON could provide for ~4000 hours of operation in the wintertime. To enable full operation all year around, a purchase of tap water would be necessary. The economical calculations resulted in an H2 production cost of 53 SEK/kg for the linear case and 58 SEK/kg for the non-linear case. The linear case showed a positive internal rate of return, or IRR, of 1,7%, while the non-linear case resulted in IRR < -25%. A sensitive analysis was made to examine governing parameters. The results of the sensitivity analysis showed that the largest driving variables, that significantly affect the IRR, are the price for electricity and the selling price for H2. The largest OPEX cost was found to be the price of electricity. The results showed that it is feasible to produce H2 at E.ON Örebro in a resource efficient way under certain circumstances, correlated to the electricity and H2 market. With a low electricity price and a selling price of ~50 SEK/kg for H2, good profitability is expected. It is also clear that future work should focus the areas of O2 usage, infrastructure, and market investigation for a more definitive conclusion.
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Melchior, Frédéric. "Obtention et production d'anticorps monoclonaux pour la détéction directe d'alcaligenes eutrophus CH34." Metz, 1998. http://docnum.univ-lorraine.fr/public/UPV-M/Theses/1998/Melchior.Frederic.SMZ9844.pdf.
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Alcaligenes eutrophus CH34, bactérie à gram négatif et ayant un métabolisme chimiolithotrophe facultatif, possède deux mégaplasmides pMOL28 et pMOL30 de résistances aux métaux lourds (Cd, Zn, Co, Ni, Cu, Tl, chromates, Hg et Pb. Des membranes externes de cette bactérie, cultivée avec (0,0096 g/l) ou sans fer, ont été isolées par la méthode de Forsberg et al. (1970) légèrement modifiée par Falla et al. (1990). Des marqueurs spécifiques, KDO (3-céto-2-déoxyoctonate) et SDH (succinate déshydrogénase), de la membrane externe et de la membrane cytoplasmique respectivement ont été dosés. Ils indiquent que la membrane externe a été séparée avec un bon rendement (> 90%) et sans contamination par la membrane cytoplasmique. Une étude électrophorétique de cette enveloppe bactérienne a révélé qu'en absence de fer, cinq protéines de 80, 63,5, 63, 41 et 29 kDa étaient surexprimées. Les membranes externes de bactéries cultivées en absence de fer ont permis d'immuniser des souris afin de produire des anticorps monoclonaux. Un total de 200 hybridomes producteurs d'anticorps ont été testés en ELISA. La plupart d'entre eux présentaient des réactions croisées avec Escherichia coli ou Klebsiella aerogenes. Deux d'entre eux, les hybridomes B5/7 et B5/9, produisent des anticorps monoclonaux spécifiques d'Alcaligenes eutrophus CH34. Une analyse en Western blot a indiqué que ces derniers reconnaissaient une protéine spécifique d'un poids moléculaire d'environ 41 kDa. Une étude en immunofluorescence a montré que cette protéine était exposée sur la surface de la membrane externe. L'ensemble de ces résultats suggère que cette protéine est impliquée dans le mécanisme de transport du fer. La présence des deux megaplasmides est requise pour l'expression de cette dernière. Cela semble suggérer un premier lien entre le mécanisme de résistance aux métaux lourds et le transport du fer chez alcaligenes eutrophus CH34
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MELCHIOR, FREDERIC Bauda Pascale. "OBTENTION ET PRODUCTION D'ANTICORPS MONOCLONAUX POUR LA DETECTION DIRECTE D'ALCALIGENES EUTROPHUS CH34 /." [S.l.] : [s.n.], 1998. ftp://ftp.scd.univ-metz.fr/pub/Theses/1998/Melchior.Frederic.SMZ9844.pdf.
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Michel, Johannes. "The Sustainability of Decentralized Bioenergy Production : Case Study: The 'Bioenergy Village' Bollewick." Thesis, Uppsala universitet, Institutionen för geovetenskaper, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-194437.
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The concept of Sustainable Development is an interdisciplinary science. Transcending various academic fields the concept shows paths how the needs of present and future generations can be met through economic development on a finite natural resource base. Global warming and rising sea levels are just two of a series of phenomena that are directly attributable to human-induced increasing greenhouse gas levels in the atmosphere as consequence of the combustion of fossil fuels. Therefore, reducing greenhouse gas emissions through the use of renewable resources such as bioenergy are of vital importance if detrimental environmental effects are to be mitigated. The production of biogas in a decentralized context is receiving much attention in Germany as a means to reduce greenhouse gases and to counteract correlated negative environmental effects, respectively. In addition, socio-economic benefits such as local employment creation have the potential to empower rural communities. Subsidised by the German Renewable Sources Act and its various remuneration schemes, two 500kWel CHP biogas plants are producing through anaerobic digestion of maize silage and manure electricity and heat in the East German village Bollewick, which is the case study. The sustainability of this decentralized system is analyzed by applying a set of indicators. Socio-economic benefits for the population, economic efficiency of the digestion process and impacts of substrate costs on the profitability, greenhouse gas emissions due to land use change and biodiversity loss being some of these indicators. The thesis concludes that none of the sustainability indicators are sufficiently fulfilled in Bollewick. Especially the cultivation of the energy crop maize has despite crop rotations immense negative environmental effects. Therefore, the decentralized biogas production in the rurally coined village Bollewick is not sustainable.
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Sallent, Roger. "Return temperature influence of a district heating network on the CHP plant production costs." Thesis, University of Gävle, University of Gävle, Department of Technology and Built Environment, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-4989.
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<p><strong></strong>The aim of this Project is to study the influence of high return temperatures in district heating on the costs for heat and power production in a CHP plant.When the temperatures of the water coming back to the heating plant are so high, the overall performance of heat and power production is decreased and, consequently, also the production costs. Along the project, the influence of this temperature on the different parts of a CHP plant are analysed as well as the economical impact it has. At the same time, some general impacts on the entire network are mentioned.</p><p> </p><p>A real network is used in this project, and it is the net of district heating in Gävle (Sweden), and the most of the study is focus in its bigger combined heat and power production plant (CHP), called Johannes.</p>
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Jonckeau, Agathe. "Production, purification et caractérisation d’une gonadotropine chorionique équine recombinante à usage vétérinaire." Thesis, Bordeaux, 2016. http://www.theses.fr/2016BORD0208.
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Des hormones gonadotropiques sont utilisées pour la maîtrise de la reproduction dans le domaine vétérinaire. Ces hormones sont actuellement extraites de tissus ou de fluides animaux. L’entreprise CEVA Santé Animale a récemment fait le choix stratégique de produire ces hormones par voie recombinante. L’objectif de cette étude était d’obtenir une gonadotropine chorionique équine recombinante, reCG, pure et biologiquement active, à partir d’une lignée de cellules mammifères CHO. Les étapes de production, de purification et de caractérisation de l’hormone recombinante ont été développées. Les cellules CHO ont été cultivées en fiole d’Erlenmeyer dans différents milieux de culture. Le suivi de la croissance cellulaire et de la quantité d’hormone produite a permis de sélectionner deux milieux. Le procédé de production, avec ces deux milieux, a été optimisé en bioréacteur en contrôlant les paramètres de culture (température, pH). Les protéines produites dans le surnageant, de ces deux cultures, ont été nommées reCG 1 et reCG 2. Un procédé de purification en 3 étapes a été mis au point pour la reCG 1. Plusieurs résines et conditions chromatographiques ont été criblées en microplaques. Les résines multimodales utilisées ont permis d’éliminer des contaminants majeurs grâce à leur sélectivité. Les agrégats de la reCG ont été éliminés grâce à une résine anionique. Le procédé de purification global a été validé pour la reCG 1 et la reCG 2. Il a permis d’obtenir une pureté de 98 % avec un rendement de 80 %. L’activité biologique de la reCG 1 et la reCG 2, in vitro et in vivo, est comparable à celle de la protéine naturelle. L’activité biologique in vivo des reCG est cohérente avec l’étude réalisée sur les glycosylations des hormones et notamment avec leur degré de sialylation<br>The gonadotrophic hormones are used for reproduction control in farming animals. Up to now, these hormones were extracted from animal fluids or tissues. The company CEVA Santé Animal has recently decided to produce recombinant versions of these hormones. The objective of this study was to obtain a pure and biologically active recombinant equine chorionic gonadotropin (reCG) after expression in CHO mammalian cells. The production, purification and characterization steps have been developed. CHO cells were grown in Erlenmeyer flasks with different culture media. Two media were selected based on their cell growth potency and of the amount of reCG produced. By using a bioreactor to control key parameters (temperature, pH), the production process was then optimized. The recombinant proteins that accumulated in the supernatant of the two conditions were called reCG 1 and reCG 2. A 3-steps purification process was then developed using reCG 1. Several resins and chromatographic conditions were screened in microplates. Multimodal resins were used to eliminate the main contaminants thanks to their selectivity. reCG aggregates were efficiently eliminated by a chromatographic step with an anionic resin. The overall purification process was finally validated for reCG 1 and reCG 2. Purity and yield were respectively, 98 % and 80 % for the two reCG. We verified that the in vitro and in vivo activities of reCG 1 and reCG 2 were comparable to those of the CG extracted from natural sources. The in vivo assays also confirmed previous studies showing that the degree of glycosylation of an hormone, and most notably their level of sialytation, is important for their biological activity
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Lamotte, Damien. "Production et glycosylation de l'interféron-gamma humain par des cellules CHO cultivées en bioréacteurs discontinus et perfusés : influence des conditions opératoires et du potentiel de glycosylation des cellules." Vandoeuvre-les-Nancy, INPL, 1997. http://www.theses.fr/1997INPL061N.
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L’objectif général de ce travail est l'étude de la production et de la glycosylation de l'interféron-gamma humain recombinant (IFN) exprimé par différentes lignées de cellules animales CHO (Chinese Hamster Ovary) cultivées en bioréacteurs discontinus et perfusés. La première partie traite de l'influence de l'intégration du gène de l'[alpha]2,6-sialyltransferase ([alpha]2,6-ST) dans une lignée CHO produisant l'IFN sur les cinétiques de cultures en réacteurs discontinus (croissance cellulaire, consommation des nutriments et production d'IFN), et sur l'état de glycosylation de la glycoprotéine produite. La modification de la cellule permet d'accroitre la sialylation globale de l'IFN et de lier des acides sialiques en position [alpha]2,6 sans compromettre les capacités de croissance et de production de la cellule. La deuxième partie concerne l'influence de certains composants du milieu de culture lors de cultures discontinues. Le sérum de veau fœtal (10%) augmente les concentrations maximales en cellules et en IFN, mais altère dramatiquement la structure polypeptique et glycannique de l'IFN. L'ajout de butyrate de sodium (1 mM) en cours de phase de croissance augmente fortement la production d'IFN. De plus, lors de la culture de la lignée modifiée pour l'expression de l'[alpha]2,6-ST, le butyrate accroit la sialylation totale ainsi que le pourcentage d'acides sialiques lies en position [alpha]2,6. La troisième partie étudie la possibilité de produire l'IFN dans un réacteur perfusé muni d'un décanteur cellulaire interne. Cette configuration permet la rétention totale des cellules et la production d'IFN pendant plus de 1000 heures. La densité cellulaire et la production volumique d'IFN sont respectivement 3 et 8 fois plus importantes qu'en culture discontinue. Ce mode perfusé présente également l'avantage, par rapport au mode discontinu, de stabiliser l'hétérogénéité de la glycosylation de l'IFN.
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Binge, Alexandra. "Development of endogenous and synthetic CHO promoter expression systems for recombinant protein production." Thesis, University of Kent, 2018. https://kar.kent.ac.uk/66640/.
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Chinese hamster ovary (CHO) cells are the most commonly used mammalian cell expression system for the industrial production of biotherapeutic recombinant proteins. Mammalian expression systems are a popular choice for the production of complex biopharmaceuticals due to their ability to correctly fold and assemble recombinant proteins and to carry out necessary human-like post-translational modifications. Traditionally, viral promoters are used to drive transgene expression in mammalian cells. This study reports on the investigation of endogenous CHO promoters as potential alternatives to the commonly used strong viral promoters such as SV40 and CMV. Although these promoters provide high recombinant gene expression, this is not always favourable as constitutive transgene over expression can ultimately lead to cellular stress. Furthermore, viral promoters have been reported to undergo silencing mechanisms over long culture periods, compromising product titers. Endogenous and synthetic CHO putative promoter sequences were investigated for their abilities to drive reporter and recombinant gene expression both in stable and transient systems. Initially a panel of ten putative promoters were identified from the literature, these being identified for this study as the associated gene or protein had been reported to have high transcript or protein amounts in CHO cells. The sequence 400 bp upstream of the transcript or translation start site of these genes was cloned into a promoterless eGFP reporter vector and their ability to drive transient gene expression examined. The ability of these putative promoters to drive eGFP expression was generally inferior to that of the viral SV40 promoter and always many-fold lower than that observed from the viral CMV with enhancer promoter. Regions 2 kb upstream from the transcript or translation site for each gene were then cloned into the promoterless eGFP reporter system to assess for promoter activity further upstream. For one of the 2 kb sequences, eGFP expression was enhanced above that observed from the equivalent 400 bp sequence and was greater than that from the SV40 promoter. A further nine target putative promoters were then identified from published RNAseq studies and sequences 500 bp upstream of the transcriptional start site of identified genes were cloned. Of the nine 500 bp sequences, three displayed promoter activity equivalent to or above that of SV40 and so regions 2 kb upstream of the transcriptional start site of these genes were investigated for further promoter activity. The use of the 2 kb segments resulted in an increase in stable but not transient eGFP expression from that observed from the 500 bp sequences alone. When placed directly downstream of the CMV enhancer two of the 2 kb sequences showed higher eGFP expression than when the CMV enhancer was not present. The CMV enhancer had no impact when upstream of the two other 2 kb sequences investigated showing this to be a sequence dependent effect. The 2 kb sequence which exhibited the strongest promoter activity of targets when driving transient eGFP expression, in addition to the two sequences with the CMV enhancer which showed enhanced transient eGFP expression, were investigated for their ability to drive IgG heavy and light chain, and hence IgG, stable expression in CHO cells compared to the CMV promoter with enhancer. Upon generation of pools and mini pools stably producing IgG under the control of the various promoters, the CHO endogenous 2 kb promoter outperformed the synthetic candidates, the CMV with enhancer and an industrially relevant control promoter. Indeed, the endogenous CHO promoter sequence was shown to achieve product titers of up to 3-fold greater than those from the commonly used CMV promoter with enhancer in CHO cells, demonstrating the potential for endogenous promoters to replace typically used viral promoters for recombinant gene expression. Further, colonies emerged faster after transfection and selection when using this promoter compared to the others investigated and a larger range of higher-expressing pools were available for investigation. In summary, this study has identified an endogenous CHO promoter sequence able to drive IgG expression beyond that of current widely used viral promoters and has generated additional promoters exhibiting a range of abilities to drive recombinant gene expression to varying amounts that could be applied to cell engineering approaches in the future.
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De, Villiers Ann-Marie. "Production and glycosylation of a recombinant protein from Chinese hamster ovary (CHO) cells." Thesis, Stellenbosch : Stellenbosch University, 2012. http://hdl.handle.net/10019.1/71663.
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Thesis (MScEng)--Stellenbosch University, 2012.<br>ENGLISH ABSTRACT: Recombinant glycoproteins are important biopharmaceuticals, providing solutions for numerous previously untreatable illnesses, in everything from cancer to infertility. Most recombinant biopharmaceuticals are produced in mammalian cells due to their ability to provide the correct post-translational processing for use in humans. The post-translation processing influences many of the protein’s properties including pharmacokinetics, bioactivity, secretion, half-life, solubility, recognition and antigenicity. The aim of this thesis is to further study the upstream production of a glycosylated recombinant protein produced by Chinese hamster ovary (CHO) cells on production scale within the confines of an existing process.
The process in question uses adherent CHO cells to produce a glycosylated recombinant hormone. As with most recombinant protein production processes, this process has two sections to the upstream production: a seed train to grow enough cells to inoculate production, and a production section, which focuses on the production of a recombinant protein. The seed train is predominantly conducted in roller bottles, while the production section takes place in perfusion bioreactors, where the cells are attached to microcarriers, with spin-filters for cell retention. The whole process uses medium with serum.
There are two process challenges regarding an existing recombinant-protein production process:
1. The gradual increase, over the past several campaigns, of the final population doubling level of the cells (which must remain within certain specified limits) at the end of the seed train.
2. The low glycosylation levels of the product seen in certain campaigns, which meant that a certain number of final product batches were below the specified acceptable glycosylation limits.
Following a literature survey several controlled process variables were chosen for investigation and hypotheses made on their effect on the seed train or glycosylation.
To investigate their effect on the PDL and cell growth in the seed train:
- Medium volume: decreasing the medium volume will yield a lower PDL due to slower cell growth caused by lower glucose availability.
- Seeding density: if cells obtain confluence by the time they are harvested, decreasing the seeding density will yield a higher PDL.
- Cultivation temperature: decreasing the temperature ought to decrease the growth rate.
- Medium feed temperature: there will be no significant difference to the cell culture when pre-heated or cold medium is used. Aeration: using vent caps will increase the oxygen content of the medium in the roller bottles and the cell growth, yielding a higher PDL.
To investigate their effect on glycosylation during production:
- pH: better glycosylation will be seen at pH 6.9, than at pH 6.7.
- Perfusion rate: a higher perfusion rate will lead to better glycosylation due to increased glucose and glutamine concentrations.
In the seed train, the only factor that significantly influenced the final PDL was the seeding density. Cell growth was inhibited once cells reached confluence, so lowering the seeding density lead to a higher PDL. It is recommended to use a high seeding density to ensure a lower PDL.
Historic data indicated that the seeding density was not the cause of the apparent increase of the final PDL, as all previous campaigns had been seeded with a high seeding density. What then became apparent was that the final PDL remained relatively constant during a campaign and that the increase in final PDL occurred between campaigns. It appears that the apparent increase in the final PDL is due to differences in cell counting between operators as each new campaign was managed by different operators. It is recommended that a mechanical cell counter be used to verify cells counts and to maintain a standard between campaigns.
In the bioreactors, varying the pH proved to have no significant effect on the glycosylation levels. However, both the initial perfusion rate and the specific perfusion rate proved to be important from both historical data and the data generated during these experiments.
Lower levels of the initial perfusion rate lead to better glycosylation and it is recommended that an initial perfusion rate of 1.0 volumes/day be used. The relationship between the specific perfusion rate and the glycosylation appears to be non-linear and requires further study, for now it is recommended that the specific perfusion rate be kept below 0.3 volumes/day/109 cells.
Probable reasons for the unsatisfactory glycosylation seen in certain runs could also be proposed from these two factors:
• RP33-133 : Very high specific perfusion rate
• RP32-135 : High initial perfusion rate and very high specific perfusion rate
• RP32-138 : High initial perfusion rate
• RP33-139 : High initial perfusion rate
Further research is recommended into the effect of the specific perfusion rate as well as the specific glucose consumption rate and the specific glutamine concentration on the glycosylation.<br>AFRIKAANSE OPSOMMING: Rekombinante glikoproteïene is baie belangrike biofarmaseutiese produkte wat oplossings bied vir talle voorheen ongeneeslike siektes in alles van kanker tot onvrugbaarheid. Meeste rekombinante farmaseutiese produkte word gemaak deur diere-selle as gevolg van hulle bevoegtheid om die korrekte na-translasie stappe te volg sodat die produkte in mense gebruik kan word. Die na-translasie stappe beïnvloed baie van die proteïene se karaktertreke insluitende die farmakokinetika, bioaktiwiteit, uitskeiding, half-leeftyd, oplosbaarheid, herkenbaarheid and antigeniciteit. Die doel van hierdie tesis is om die stroomop produksie van ‘n rekombinante glikoproteïene vervaardig deur Chinese hamster ovariale (CHO) selle verder te bestudeer binne die grense van ‘n bestaande proses op grootskaalse vlak.
Die huidige proses gebruik CHO selle om ‘n rekombinante glikohormoon te produseer. Soos meeste prosesse wat rekombinante proteïene produseer bestaan die stroomop gedeelte van die proses uit twee dele: ‘n saad trein wat genoeg selle maak vir produksie en ‘n produksie gedeelte wat fokus op die vervaardiging van die glikoproteïen. Die saad trein bestaan hoofsaaklik uit roller bottels terwyl produksie plaasvind in perfusie bioreaktors waar die selle op “microcarriers” groei, met spin-filters om die selle binne die bioreaktors te hou; die hele proses gebruik medium met serum.
Daar is twee probleme in die stroomop gedeelte van die bestaande proses:
1. Die geleidelike toename oor die afgelope paar jaar van die finale verdubbelingsvlak van die selle aan die einde van die saad trein
2. Die lae glukosilering van die eindproduk wat veroorsaak dat sekere lotnommers buite spesifikasie is
Na ‘n literatuur studie, was seker beheerde proses parameters gekies om verder te bestudeer en hipotesisse gemaak oor hulle effek op die saad trein of die vlak van glukosilering.
Die volgende faktore is bestudeer vir hulle effek op die finale verdubbelingsvlak van die selle in die saad trein:
- Medium volume: ‘n laer medium volume sal lei tot a laer verdubbelingsvlak van die selle as gevolg van stadige groei
- Konsentrasie van selle vir inokulasie: as die selle konfluent is teen die tyd wat hulle versamel word sal ‘n laer konsentrasie selle lei tot ’n hoër verdubellingsvlak.
- Temperatuur: laer temperatuur behoort te lei tot ‘n stadiger groei koers van die selle
- Medium voer-temperatuur: die voer-temperatuur van die medium sal geen beduidende verskil maak
- Belugting: die gebruik van “vent-caps” sal die suurstof inhoud van die roller bottels verhoog
Die volgende faktore is bestudeer vir hulle effek op die glukosilering tydens produksie:
- pH: beter glukosilering word verwag by by pH 6.9 dan by pH 6.7
- Perfusie koers: ‘n hoër perfusie koers sal lei tot beter glukosilering as gevolg van hoër glukose en glutamien konsentrasies
Die konsentrasie van die selle wat gebruik word vir inokulasie blyk die enigste faktor te wees wat die finale verdubbelingsvlak van die selle en die groei van die selle in die saad trein beïnvloed het. Die groei van die selle was beprek wanneer die selle konfluent geraak het en dus het ‘n laër sel konsentrasie by inokulasie gelei tot ‘n hoër sel verdubbelingsvlak. Dit word aanbeveel dat ‘n hoë sel konsentrasie by inokulasie gebruik word.
Die geleidelike toename van die finale verdubbelingsvlak van die selle in die saad trein is waarskynlik as gevolg van die variasie in sel tellings tussen verskillende operateurs eerder as as gevolg van die beheerde proses parameters. Dit word aanbeveel dat ‘n meganiese sel-teller gebruik word om die verskil in sel tellings tussen operateurs te kontroleer en om ‘n standaard te handhaaf tussen produksie lotte.
In die bioreaktors, het die pH geen beduidende invloed gehad op die glukosilering maar uit historiese data en die huidige data van hierdie eksperimente blyk albei die begin perfusie koers en die spesifieke perfusie koers ‘n belangrike invloed te hê op die glukosilering.
Laër vlakke van die begin perfusie koers lei tot beter glikosilsie en dit word aanbeveel dat elke produksielot ‘n begin perfusie koers het van 1.0 volume/dag. Die verhouding tussen die glukosilering en die spesifieke perfusie koers blyk om nie-liniêr te wees nie. Nog navorsing hieroor word aanbeveel, maar vir nou word dit aanbeveel dat die spesifieke perfusie koers onder 0.3 volumes/dag/109 selle gehou word. Hierde twee faktore blyk die oorsaak te wees vir die lae glukosilering wat in sekere produksielopies gevind was:
• RP33-133 : baie hoë spesifieke perfusie koers
• RP32-135 : hoë begin perfusie koers en baie hoe spesifieke perfusie koers
• RP32-138 : hoë begin perfusie koers
• RP33-139 : hoë begin perfusie koers
Dit word aanbeveel dat verdere navorsing gedoen word op die effek van die spesifieke perfusie koers asook die spesifieke koers van glukose verbruik en die spesifieke glutamien konsentrasie op die glukosilering van die produk.
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Stevens, Kristoffer. "Integratedenergy storage system for optimal energy production : A case study on Johannes CHP biofuel plant." Thesis, Högskolan i Gävle, Avdelningen för bygg- energi- och miljöteknik, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:hig:diva-14906.
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This project served to analyze the effects that energy storage can have on energy production. The study was aimed at Johannes CHP bio fuel. Johannes produces electricity for the SE3 region and heat for the district heating in Gävle. The electricity market is the main driving factor for energy production. It is ideal for Johannes to produce as much electricity as possible during high Elspot prices. Two accumulator tanks are already installed at Johannes so the surplus of heat can be stored from high electrical production. This study served to utilize the planning horizons for the future Elspot prices. The two forecasting methods presented are the 12 hour prices presented by Nord pool and the four day forecast predicted by ARIMA modeling. Several different energy storage technologies were theoretically discussed after which Gravity Potential Module, latent heat storage using phase change materials and open accumulator tanks were analyzed. The ideal system proved to be utilizing the four day ARIMA modeled forecast with a storage system consisting of Gravity Potential Module and latent heat storage. The system resulted in a gross profit of 1.4 million SEK and an increased average electrical production efficiency of .02% during 2011.
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Bjørnstad, Pål Marius. "Central exclusive production of χ mesons at LHCb". Thesis, University of Manchester, 2013. https://www.research.manchester.ac.uk/portal/en/theses/central-exclusive-production-of-chi-mesons-at-lhcb(64c3f7d8-3c71-4e4b-a592-69a6e27424d7).html.
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The LHCb experiment is a forward spectrometer at the Large Hadron Collider, covering a range of pseudorapidity 1:9 < η < 4:9. It has a very precise vertex detector called the VELO, near the interaction point. The monitoring software for the VELO is discussed in this thesis. In proton-proton interactions, Central Exclusive Production (CEP) is a process where the protons remain intact after the interaction, and an additional simple central system is produced. CEP processes are selected experimentally by requiring that there is no activity in the detector apart from the central system. The installation of additional detectors to increase the sensitivity at small angles from the beam axis is discussed. A geometrical description of the region of the LHC up to 100mon each side of the LHCb interaction point is developed. Simulated forward shower counters are added to the model, and the efficiencies of the detectors are measured.
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Goulart, Dickson C. "J/PSI production via chi sub C decays in fixed target proton-nucleus collisions." Cincinnati, Ohio University of Cincinnati, 2004. http://www.ohiolink.edu/etd/view.cgi?acc%5Fnum=ucin1100189506.
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Huang, Edwin P. C. Biotechnology & Biomolecular Sciences Faculty of Science UNSW. "Recombinant protein production utilising a metallothionein expression system and a Super-CHO cell line." Awarded by:University of New South Wales. School of Biotechnology and Biomolecular Sciences, 2006. http://handle.unsw.edu.au/1959.4/24940.
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A novel metal-inducible and amplifiable metallothionein (MT) expression system, pNK, was firstly optimised and characterised for the production of a reporter protein, human growth hormone (hGH) in a suspension CHO cell line grown in a serum-free media. The pNK-based hGH production was demonstrated in cadmium-free condition under various fermentation modes (batch, fed-batch and perfusion) and scales (flask to bench-top bioreactor). Improvement of specific productivity of recombinant protein from pNK was shown to be possible by addition of butyrate or substrate substitution of glutamine by glutamate. Combination of fed-batch and butyrate addition strategies resulted in more than one gram per litre of hGH being obtained from the pNK expression system in a bioreactor. In the second part of the project, based on a statistical approach suggested by Plackett-Burman (P-B), a chemically-defined and protein-free medium, named Super-CHO protein-free (SPF), was developed to support a Super-CHO cell line, C2.8-325, to grow as a single-cell suspension culture with comparable growth rate and viable cell number as observed in a commercial medium containing undefined additives. Using Dulbecco's Modified Eagle's Medium/Ham's F12 1:1 mixture (DMEM/F12) as the basal medium, a P-B design matrix screened 10 nutritional components. Components shown potentially beneficial for cell growth rate and viable cell number were supplemented to DMEM/F12 to formulate the SPF medium. Finally, the pNK expression system and the Super-CHO cell line were applied simultaneously in an attempt to express a humanised anti-CD48 monoclonal antibody (MAb), IgG1-N2A (N2A-MAb). This aimed to test C2.8-SPF grown in newly developed SPF medium for transfection, clone development and recombinant protein production. A stable and N2A-MAb expressing C2.8-SPF cell line was successfully constructed, and N2A MAb expression was subsequently amplified and demonstrated in various cultivation scales (flask and bioreactor). This project demonstrated that the novel metal-inducible and - amplifiable mammalian expression system, pNK, and the novel mammalian host cell-line, Super-CHO C2.8-SPF, capable of growing as a single-cell suspension culture in a chemically-defined protein-free medium, SPF, could be utilised in combination to provide a new, low-cost, and regulatory-compliant recombinant protein expression platform, suitable for the biopharmaceutical industry to use in the manufacture of therapeutic recombinant proteins.
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Almanan, Maha. "CD4+ T cell Production of IL-10 and Regulation of Immune Responses in Aging." University of Cincinnati / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1535466924008943.
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Achaica, Santos Angelica, Huamanchumo Jackeline Liz Arce, Salcedo Angel De Jesús Calle, Huamán Rocio del Pilar Silva, and Xiuwen Zhou. "Hao Hao Chi." Bachelor's thesis, Universidad Peruana de Ciencias Aplicadas (UPC), 2020. http://hdl.handle.net/10757/654898.
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El trabajo realizado presenta un modelo de negocio que pertenece a la industria de alimentos y bebidas, y se dedicará a la producción y comercialización de bocaditos chinos congelados y empaquetados al vacío en el departamento de Lima, Perú. Mediante la recopilación de información obtenida del análisis PESTEL, se determinó la situación actual de los factores Macroentorno del país para estar preparados ante situaciones inusuales. Asimismo, se consideró relevante el estudio de las cinco fuerzas de Porter para abordar los factores de Microentorno que tiene relación con la industria que deseamos ingresar, esta fase permite conocer el comportamiento y el poder de negociación de ciertos factores como los clientes, proveedores y la competencia. Además, se hizo un estudio minucioso del mercado con entrevistas a profundidad y encuestas al consumidor final, dueños o colaboradores de los restaurantes chifas y otros negocios similares, a fin de definir la idea de negocio y las verdaderas necesidades de nuestro público objetivo para dar el enfoque correcto y tomar las decisiones empresariales más adecuadas.
Toda actividad relacionada con la producción, tales como: la elaboración, conservación, distribución e inversión de activos, son analizados en relación a la demanda y según la capacidad proyectada del establecimiento, por ende, el sabor, la calidad y presentación de los bocaditos serán producidos según las exigencias del público objetivo.<br>The work carried out presents a business model that belongs to the food and beverage industry, and will be dedicated to the production and marketing of frozen and vacuum-packed Chinese snacks in the department of Lima, Peru. Through the compilation of information obtained from the PESTEL analysis, the current situation of the country's Macroenvironment factors was determined to be prepared for unusual situations. Likewise, the study of Porter's five forces was considered relevant to address the Microenvironment factors that are related to the industry we wish to enter, this phase allows knowing the behavior and bargaining power of certain factors such as customers, suppliers and the competition. In addition, a thorough study of the market was carried out with in-depth interviews and surveys of the final consumer, owners or collaborators of chifas restaurants and other similar businesses, in order to define the business idea and the true needs of our target audience to give the correct approach and make the most appropriate business decisions.
All activities related to production, such as: the preparation, conservation, distribution and investment of assets, are analyzed in relation to demand and according to the projected capacity of the establishment, therefore, the taste, quality and presentation of the snacks will be produced according to the demands of the target audience.<br>Trabajo de investigación
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Vidlund, Anna. "Sustainable production of bio-energy products in the sawmill industry." Licentiate thesis, KTH, Chemical Engineering and Technology, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-1734.
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<p>One of the great challenges facing society is to convert theglobal energy system to a sustainable process. Currently, 80%of the world´s energy is supplied through the combustionof fossil fuels. Not only are the fossil resources limited, theutilisation also increases the level of greenhouse gases in theatmosphere. The convertion to a sustainable energy system isproblematic since the technology needed to exploit mostnon-fossil energy sources is not yet fully developed, e.g.solar energy. Biofuel is an available renewable energy sourcewhich is already widely used in many countries. If an effectiveswitch-over from fossil fuels to biofuels is to be realised,biofuels must be viewed as a limited resource. Consequently, itis important that the handling, upgrading and utilisationprocesses involving biofuels are efficient so that itspotential can be fully exploited.</p><p>This thesis considers efficient biofuel utilisation andupgrading within the sawmill industry. The goal has been toanalyse not only the technical opportunities for energy savingsin the sawmill industry, but also to analyse the costeffectiveness and environmental impact of studied measures. Theheat demand of the sawmill industry is almost completelycovered by its own by-products; primarily bark, sawdust andwood chips. The increased demand and improved economic value ofwoody biofuels on the market is thus an incentive for thesawmill industry to place more focus on energy issues. Thesawmill industry also has a more or less constant heat loadover the year, which is a beneficial factor for integrationwith district heating networks, biofuel upgrading plants andcombined heat and power plants.</p><p>The conclusion of the study is that a variety of energyproducts such as heat, unrefined biofuel, pellets andelectricity can be efficiently produced in the sawmill industryand sold for profit to external customers. The payback periodsfor the proposed investments are moderate and both theemissions of volatile organic compounds and global CO2 aredecreased. Should the proposed measures be fully implemented atSwedish sawmills, about 2.8 TWh of biofuel could be savedannually, 0.5 TWh of waste heat could be sold as districtheating and 0.8 TWh of green electricity could be produced.Language: English</p><p><b>Keywords:</b>Sawmill industry, energy efficiency, heatrecovery, integration, biofuel, upgrading, district heating,fuel pellets, CHP, VOC, CO2</p>
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Lipscomb, Matthew L. "Perfusion cultures of recombinant CHO cells: Effects on specific productivity, production stability, and protein glycosylation." Diss., Connect to online resource, 2005. http://wwwlib.umi.com/dissertations/fullcit/3165829.
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Fox, Stephen Richard. "Active hypothermic growth : a novel means for increasing total recombinant protein production by CHO cells." Thesis, Massachusetts Institute of Technology, 2005. http://hdl.handle.net/1721.1/32333.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2005.<br>Includes bibliographical references (p. 225-240).<br>Recombinant human glycoproteins produced by Chinese Hamster Ovary (CHO) cells are an important class of therapeutic molecules and investigating means of improving the production rate and product quality of these glycoproteins is therefore of great interest. Culturing CHO cells under mild hypothermia (30-33 ⁰C) leads to growth arrest in the G₀/G₁ phase of the cell cycle and, in some cases, causes an increase in specific productivity of recombinant protein, as was shown here for the model CHO cell line producing human interferon-gamma (IFN-[gamma]). Controlled proliferation, achieved by inducing growth arrest in the G₀/G₁ phase by chemical, environmental or genetic means, is commonly used to increase CHO specific productivity and thus there is speculation that enhanced hypothermic productivity is due to growth arrest. However, it was proven here that the positive effect of hypothermia on recombinant protein production is due to elevated IFN-[gamma] mRNA levels instead. At both 32 ⁰C and 37 ⁰C, specific productivity is growth-associated, increasing as the percentage of cells in the S phase increased, demonstrating that a cell line can be both a growth-associated producer and have enhanced productivity under hypothermic conditions. It was hypothesized that the best production platform would be cells actively growing at low temperature and this was proven to be the case using two different methods, namely growth factor supplementation and selection of cells capable of hypothermic growth. Both methods gave multi-fold increases in total IFN-y production compared to the 32 ⁰C and 37 ⁰C controls, thereby validating the novel culture strategy of active hypothermic growth.<br>(cont.) Cells capable of achieving significant hypothermic growth were also isolated for the non-recombinant CHO-KI cell line and are now available for the future production of any recombinant protein. Glycoprotein quality is partially assessed by the level of glycosylation and IFN-[gamma] contains two potential N-linked glycosylation sites. This thesis gives the first report of a detrimental effect of hypothermic culture on glycosylation, showing a 4-5% decrease in the end-of-batch percentage of 2-sites occupied glycoforms relative to the 37 ⁰C control. However, this negative effect is completely eliminated by culturing under perfusion conditions.<br>by Stephen Richard Fox.<br>Ph.D.
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ÖHMAN, AXEL. "Green hydrogen production at Igelsta CHP plant : A techno-economic assessment conducted at Söderenergi AB." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-299434.
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The energy transition taking place in various parts of the world will have many effects on the current energy systems as an increasing amount of intermittent power supply gets installed every year. In Sweden, just as many other countries, this will cause both challenges and opportunities for today´s energy producers. Challenges that may arise along with an increasingly fluctuating electricity production include both power deficits at certain times and regions but also hours of over-production which can cause electricity prices to drop significantly. Such challenges will have to be met by both dispatchable power generation and dynamic consumption. Conversely, actors prepared to adapt to the new climate by implementing new technologies or innovative business models could benefit from the transition towards a fully renewable energy system. This thesis evaluates the techno-economic potential of green hydrogen production at a combined heat and power plant with the objective to provide decision support to a district heat and electricity producer in Sweden. It was in the company’s interest to investigate how hydrogen production could help reduce the production cost of district heat as well as contribute to the reduction of greenhouse gases. In the project, two separate business models: Power-to-gas and Power-to-power were evaluated on the basis of technical and economic performance and environmental impact. To do this, a mathematical model of the CHP plant and the hydrogen systems was developed in Python which optimizes the operation based on costs. The business models were then simulated for two different years with each year representing a distinctly different electricity market situation. The main conclusions of the study show that Power-to-gas could already be profitable at a hydrogen retail price of 40 SEK per kg, which is the projected retail price for the transportation sector. The demand today is however limited but is expected to grow fast in the near future, especially within heavy transportation. Another limiting factor for hydrogen production showed to be the availability of storage space, as hydrogen gas even at pressures up to 200 bar require large volumes. Power-to-power for frequency regulation was found to not be economically justifiable as the revenue for providing grid services could not outweigh the high investment costs for any of the simulated years. This resulted in a high levelized cost of energy at over 3000 SEK per MWh which was mostly due to the low capacity factor of the power-to-power system. Finally, green hydrogen has the potential of replacing fossil fuels in sectors that is difficult to reach with electricity, for example long-haul road transport or the shipping industry. Therefore, green hydrogen production in large scale could help decarbonize many of society’s fossil-heavy segments. By also serving as a grid-balancer, hydrogen production in a power-to-gas process has the potential of becoming an important part of a renewable energy system.<br>Energiomställningen som äger rum i olika delar av världen kommer att ha många effekter på de nuvarande energisystemen eftersom en ökande mängd väderberoende kraftproduktion installeras varje år. I Sverige, precis som många andra länder, kommer detta att medföra både utmaningar och möjligheter för dagens energiproducenter. Utmaningar som kan uppstå tillsammans med en alltmer fluktuerande elproduktion inkluderar både kraftunderskott vid vissa tider och regioner men också timmar av överproduktion som kan få elpriserna att sjunka avsevärt. Sådana utmaningar måste mötas av både planerbar kraftproduktion och dynamisk konsumtion. Omvänt kan aktörer som är beredda att anpassa sig till det nya klimatet genom att implementera ny teknik eller innovativa affärsmodeller dra nytta av övergången till ett helt förnybart energisystem. Denna rapport utvärderar den tekno-ekonomiska potentialen för produktion av grön vätgas vid ett kraftvärmeverk med målet att ge beslutsstöd till en fjärrvärme- och elproducent i Sverige. Det var i företagets intresse att undersöka hur vätgasproduktion kan bidra till att sänka produktionskostnaden för fjärrvärme samt bidra till att minska växthusgaser. I projektet utvärderades två separata affärsmodeller: Power-to-gas och Power-to-power baserat på teknisk och ekonomisk prestanda samt miljöpåverkan. För att kunna göra detta utvecklades en matematisk modell i Python av kraftvärmeverket och vätgassystemen som optimerar driften baserat på kostnader. Affärsmodellerna simulerades sedan för två olika års elpriser för att undersöka modellens prestanda i olika typer av elmarknader. De viktigaste slutsatserna i studien visar att Power-to-gas redan kan vara lönsamt till ett vätgaspris på 40 SEK per kg, vilket är det förväntade marknadspriset på grön vätgas for transportsektorn. Efterfrågan är idag begränsad men förväntas växa snabbt inom en snar framtid, särskilt inom tung transport. En annan begränsande faktor för vätgasproduktion visade sig vara tillgången på lagringsutrymme, eftersom vätgas även vid tryck upp till 200 bar kräver stora volymer. Power-to-power för frekvensreglering visade sig inte vara ekonomiskt försvarbart, eftersom intäkterna för att tillhandahålla nättjänster inte kunde uppväga de höga investeringskostnaderna under några av de simulerade åren. Detta resulterade i en hög LCOE på över 3000 SEK per MWh, vilket främst berodde på Power-to-power-systemets låga utnyttjandegrad. Slutligen kan det sägas att grön vätgas har stor potential att ersätta fossila bränslen i sektorer som är svåra att elektrifiera, exempelvis tunga vägtransporter eller sjöfart. Därför kan storskalig grön vätgasproduktion hjälpa till att dekarbonisera många av samhällets fossiltunga segment. Genom att dessutom fungera som balansering har väteproduktion i en Power-to-gas-process potential att bli en viktig del av ett system med stor andel förnybar energi.
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Le, Floch François. "Production et glycosylation d'EPO par cellules CHO : caractérisation par électrophorèse capillaire au cours de procédés discontinus." Vandoeuvre-les-Nancy, INPL, 2003. http://docnum.univ-lorraine.fr/public/INPL_T_2003_LE_FLOCH_F.pdf.
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Ce travail a pour objectif d'améliorer la maîtrise de la glycosylation des protéines recombinantes produites par culture de cellules animales, ceci par l'étude de l'influence du procédé de culture sur la structure glycannique d'une protéine modèle: l'érythopoi͏̈étine (EPO) produite par cellules CHO. La construction du système d'étude a d'abord nécessité plusieurs étapes: la génération d'un clone CHO producteur d'EPO performant, la mise au point d'une méthode de purification de la protéine par immuno- affinité et l'adaptation d'une technique d'analyse de la glycosylation aux contraintes de notre système. Deux paramètres particuliers du procédé de culture ont donc été plus précisément étudiés au cours de ce travail: l'avancement de la culture et la présence de sérum dans le milieu. L'étude du suivi de la glycosylation de l'EPO en cours de culture discontinue avec sérum a mis en évidence une désialylation progressive de la protéine durant la deuxième partie de la culture, de même qu'une lyse cellulaire importante. Une activité sialidasique significative ayant également été observée simultanément, une dégradation enzymatique faisant suite à la lyse cellulaire semble être à l'origine de ce phénomène en présence de sérum. Après adaptation des cellules au milieu sans sérum, la désialylation de l'EPO s'est par contre révélée stable tout au long des cultures réalisées en l'absence de sérum. L'étude de la glycosylation de l'EPO produite en présence de sérum par des cellules adaptées à la culture sans sérum a montré que la désialylation de l'EPO était directement liée à la présence de sérum, et non à la procédure d'adaptation des cellules au milieu sans sérum. En conclusion, cette étude a mis en évidence l'influence significative que pouvait avoir certains paramètres du procédé de culture sur la qualité de l'EPO produite par notre système<br>The scope of this work is to improve the control of the glycosylation of recombinant proteins produced by animal cell culture by studying the influence of the culture process on the glycan structure of a model protein : CHO cell produced EPO. For building the system, several step were necessary : the generation of a high-EPO-producer CHO cell clone, the set-up of an immuno-affinity purification method and the adaptation of a technique for analysis of protein glycosylation to our system constraints. Then, two parameters of the culture process were studied more precisely : the culture time and the presence of serum. By monitoring EP9 glycosylation in the course of serum-containing batch cultures, we observed a progressive desialylation of the protein during the second part of the culture and an important cell lysis. Since a significative siaiidase activitv was also found in the same time, this phenomenon seemed to be induced by an enzymatic degradation following cell lysis in serum-containing cultures. On the other band, after serum-free adaptation, EPO sialylation was found constant during the whole serum-free cultures. Anaiysis of EPO glycosylation produced in serum-containing medium by serum-free adapted cells showed that the occurring desialylation was directly linked to the presence of serum and not to the serum-free adaptation procedure. To conclude, this work clearly shows the important influence of sorne process parameters on the quality of EPO when produced in our system
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Mathias, Sven [Verfasser]. "Identification, characterization and removal of intracellular secretion bottlenecks in industrial CHO production cell lines / Sven Mathias." Ulm : Universität Ulm, 2021. http://d-nb.info/1239737203/34.
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Abajyan, Anaida. "Characterization of altered cytokine production by memory CD4 T cells in NZBxW murine model of SLE." Doctoral thesis, Humboldt-Universität zu Berlin, 2019. http://dx.doi.org/10.18452/20094.
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Der systemische Lupus erythematodes (SLE) ist eine Autoimmunerkrankung, bei der eine Vielzahl an Organen betroffen sein kann. Hierbei spielen T-Zellen mit gestörter Zytokinproduktion, insbesondere von IL-2 und IFN-γ, eine besondere Rolle. Mit Fortschreiten der Krankheit sinkt die Anzahl an IL-2-Produzenten und gleichzeitig steigt die Anzahl an IFN-γ-Produzenten. Während die Rolle von IFN-γ in SLE bisher kontrovers diskutiert wird, wirkt sich die verringerte Produktion von IL-2 beispielsweise negativ auf regulatorische T-Zellen aus, was zur Pathogenese der Krankheit beiträgt.
In dieser Arbeit erfolgte eine Charakterisierung der Zytokinproduzierenden CD4+ Gedächtnis-T-Zellen in erkrankten NZBxW Mäusen, einem Modell für SLE. Anhand der Produktion von IL-2 und/oder IFN-γ wurde dabei in DN (IFN-γ—IL-2— doppelt negative), IL-2 SP (IFN-γ—IL-2+ einzelpositive), DP (IFN-γ+IL-2+ doppelt positive) und IFN-γ SP (IFN-γ+IL-2— einzelpositive) Zellen unterschieden. Ein mehrstufiges Verfahren der Zellsortierung ermöglichte die Isolierung der vier Zellpopulationen. Genexpressionsanalysen legten offen, dass die während der Krankheit vermehrt vorkommende Population der IFN-γ SP Zellen im Vergleich zu DP Zellen deutliche Unterschiede in ihrem Genexpressionsmuster aufweist. IFN-γ SP Zellen exprimieren u.a. verstärkt Chemokinrezeptoren, co-stimulatorische und co-inhibitorische Moleküle, sowie Apoptose-Marker und zeigen eine verminderte Produktion von Effektorzytokinen. Weiterführende funktionelle Analysen untermauerten die Expressionsdaten und zeigten eine verminderte Proliferationsfähigkeit und verstärkte Apoptose der IFN-γ SP Zellen. Die Daten zeigen, dass der Phänotyp der IFN-γ SP Zellen in erkrankten NZBxW Lupus-Mäusen gestört ist, wodurch die IFN-γ SP Zellen zur Erkrankung beitragen könnten.<br>Systemic lupus erythematosus (SLE) is an autoimmune disease, which can affect almost every organ system of the body. Thereby altered cytokine production by T cells plays an important role in the pathogenesis of the disease. With disease progression, production of IL-2 decreases and production of IFN-γ increases. It has been shown that IL-2 deficiency affects Treg homeostasis in SLE and thus contributes to its pathogenesis. The role of IFN-γ in SLE is, however, controversial.
In this work, a comprehensive characterization of four subpopulations of memory CD4 T cells of diseased NZBxW lupus-prone mice was performed. These cell subsets are DN (IFN-γ—IL-2— double negative), IL-2 SP (IFN-γ—IL-2+ single positive), DP (IFN-γ+IL-2+ double positive) and IFN-γ SP (IFN-γ+IL-2—single positive) cells. A multi-step cell sorting procedure was used to isolate these cell subsets. The data showed that IFN-γ SP cells were characterized by a different gene expression profile than DP cells. In detail, IFN-γ SP cells revealed an enhanced expression of chemokine receptors, co-stimulatory and co-inhibitory molecules as well as apoptosis markers and decreased production of effector cytokines. In addition, functional analyses showed that IFN-γ SP cells were tended to increased apoptosis and decreased proliferation. These data show an altered phenotype of IFN-γ SP cells of diseased NZBxW lupus-prone mice, which might be important for the disease pathogenesis at least in this animal model of SLE.
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Daianova, Lilia. "Lignocellulosic Ethanol Production Potential and Regional Transportation Fuel Demand." Licentiate thesis, Mälardalens högskola, Akademin för hållbar samhälls- och teknikutveckling, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:mdh:diva-13176.
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Road traffic dominates in domestic Swedish transportation and is highly dependent on fossil fuels, petrol and diesel. Currently, the use of renewable fuels in transportation accounts for less than 6% of the total energy use in transport. The demand for bioethanol to fuel transportation is growing and cannot be met through current domestic production alone. Lignocellulosic ethanol derived from agricultural crop residues may be a feasible alternative source of ethanol for securing a consistent regional fuel supply in Swedish climatic conditions. This licentiate thesis focuses on regional transport fuel supply by considering local small-scale ethanol production from straw. It presents the results of investigations of regional transport fuel supply with respect to minimising regional CO2 emissions, cost estimates for transport fuel supply, and the availability of lignocellulosic resources for small-scale ethanol production. Regional transport fuel demand between the present and 2020 is also estimated. The results presented here show that significant bioethanol can be produced from the straw and Salix available in the studied regions and that this is sufficient to meet the regions’ current ethanol fuel demand. A cost optimisation model for regional transport fuel supply is developed and applied for two cases in one study region, one when the ethanol production plant is integrated with an existing CHP plant (polygeneration), and one with a standalone ethanol production plant. The results of the optimisation model show that in both cases the changes in ethanol production costs have the biggest influence on the cost of supplying the regional passenger car fleet with transport fuel, followed by the petrol price and straw production costs. By integrating the ethanol production process with a CHP plant, the costs of supplying regional passenger car fleet with transport fuel can be reduced by up to a third. Moreover, replacing petrol fuel with ethanol can cut regional CO2 emissions from transportation by half.
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Pereira, João Nuno dos Santos. "Establishing a high titer transient gene expression process in conditioned media for CHO-DG44 cells." Master's thesis, Faculdade de Ciências e Tecnologia, 2011. http://hdl.handle.net/10362/6149.
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Dissertação para obtenção do Grau de Mestre em
Biotecnologia<br>Transient gene expression (TGE) allows for fast protein production in mammalian cells and has become a very important technology in the product development pipeline of biopharmaceuticals. Polyethylenimine (PEI) mediated, high-density transfections have allowed for transient processes exceeding ~300mg/L in CHO-DG44 cells. As such, the bottleneck of TGE is no more in the titers, but in the scale-up to volumes higher than 1L, because of the need for a medium exchange before transfection. It is known that if the transfection is done in a running culture, without a medium exchange (i.e in conditioned medium), the yields obtained are very low (~5 mg/L). In CHO-DG44 cells, this problem was explored from the point of view of transfection efficiency, gene delivery and transcription. A new insight is presented in this work: The low productivities are not due to a deficient gene delivery, but instead, to lower mRNA levels that we hypothesize to be related to a lower gene accessibility of the transfected plasmid. Further, the yields were improved from ~5mg/L to ~90mg/L (18-fold) by optimizing the conditions for transfecting in conditioned medium and utilizing sodium butyrate as a transcription enhancer. These results are expected to open paths for the successful scale-up of TGE.
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Elshereef, Abdalla Adel Sabry Abdelrazik Mohamed [Verfasser]. "Optimization of transient protein production by chemically transfected CHO suspension cells / Abdalla Adel Sabry Abdelrazik Mohamed Elshereef." Hannover : Technische Informationsbibliothek (TIB), 2018. http://d-nb.info/1166088472/34.
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Betts, Zeynep. "Assessment of the influence of chromatin elements on stability of recombinant protein production in amplified CHO cells." Thesis, University of Manchester, 2012. https://www.research.manchester.ac.uk/portal/en/theses/assessment-of-the-influence-of-chromatin-elements-on-stability-of-recombinant-protein-production-in-amplified-cho-cells(c7045083-e47b-4e64-8d96-71e59babd14d).html.
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Therapeutic proteins require proper folding and post-translational modifications (PTMs) to be effective and biologically active. Chinese hamster ovary (CHO) cells are the most frequently used host for commercial production of therapeutic proteins and DHFR-mediated gene amplification is extensively applied to generate cell lines with increased protein production. However, decreased protein productivity is observed unpredictably during the time required for scale-up with consequences for yield, time, finance and regulatory approval. Ubiquitous Chromatin Opening Elements (UCOEs) are DNA elements naturally found upstream of specific housekeeping genes, which are proposed to maintain open chromatin structure, supporting stable and high-level transgene expression by prevention of transgene silencing. In this study we have examined the interaction between UCOE and DHFR-linked amplification in relation to cell expression stability. CHO-DG44 cell lines were engineered to express erythropoietin (EPO) or a green fluorescent protein (GFP) from constructs with or without the inclusion of a UCOE. Cell lines were amplified in the presence of 250 nM metotrexate (MTX) and were then grown continuously for over 70 days in the presence and absence of MTX. Growth characteristics, protein expression, plasmid copy numbers, mRNA expression, karyotype and recombinant gene localisation (by fluorescent in situ hybridisation - FISH) were assessed for cells at stages throughout the period of long-term culture. In summary the inclusion of UCOE elements generated cells that; • achieved higher cell densities and exhibited increased production of recombinant mRNA/cell and protein yield • allowed isolation of greater numbers of high producing clones • resulted in greater mRNA recovery/recombinant gene copy• retained stable mRNA and protein expression after amplification provided MTX was present (but not in the absence of MTX when instability was observed) • exhibited a more consistent karyotype and no abnormal chromosomal rearrangements. It was concluded that the inclusion of UCOEs within expression constructs offer significant advantages for certainty of cell line generation (and the number of recovered clones for more detailed characterisation/optimisation) and that UCOEs are compatible with DHFR amplification protocols. The data suggested that enhanced cell line recovery by transcriptional enhancement of selection markers, such as DHFR.
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Elshereef, Abdalla [Verfasser]. "Optimization of transient protein production by chemically transfected CHO suspension cells / Abdalla Adel Sabry Abdelrazik Mohamed Elshereef." Hannover : Technische Informationsbibliothek (TIB), 2018. http://d-nb.info/1166088472/34.
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Agha, Mujtaba Hassan. "Integrated management of energy and production : scheduling of batch process and Combined Heat & Power (CHP) plant." Thesis, Toulouse, INPT, 2009. http://www.theses.fr/2009INPT050G/document.
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Dans un contexte de développement durable, la question énergétique constitue un des problèmes majeurs des décennies à venir. Bien que la solution pour faire face à la raréfaction de certaines ressources, l'augmentation globale de la demande l'augmentation des émissions de CO2, réside dans le développement des énergies renouvelables, il est clair que ces nouvelles technologies ne seront matures que dans plusieurs décennies. A court terme, les énergies fossiles demeureront la source principale d'énergie primaire. Il est donc essentiel de promouvoir de nouvelles méthodologies permettant une utilisation plus rationnelle de l'énergie. Dans le secteur industriel, le développement de centrales de production d'utilités sur le site industriel (en général des centrales de cogénération) contribue grandement à l'amélioration de l'efficacité énergétique des procédés. Traditionnellement, la gestion de ce type de système repose sur une approche séquentielle : ordonnancement de l'atelier de production, calcul des besoins énergétiques et planification de la centrale de cogénération. Toutefois, dans ce type d'approche, l'accent est mis avant tout sur l'atelier de production, la centrale de cogénération étant considérée comme une unité esclave. Pour améliorer le processus de décision, cette thèse développe une approche intégrée pour l'ordonnancement simultanée et cohérent des ateliers de production et des centrales de production d'utilités. La méthodologie proposée repose sur une formulation MILP à temps discret. Par ailleurs, une extension du formalisme RTN a été développée : les ERTN ("Extended Resource Task Network"). Celui-ci permet d'une part, de décrire de manière systématique les recettes et d'autre part, permet une modélisation explicite et générique des différents types de systèmes dont notamment les centrales d'utilités. Les résultats montrent que l'approche intégrée permet d'obtenir une réduction notable du coût énergétique grâce une meilleure coordination des activités de production et de fabrication d'utilités. En effet, les tâches de production sont ordonnancées de manière à consommer sur les mêmes périodes les utilités générées simultanément par la centrale de cogénération, conduisant ainsi à une réduction significative du rapport quantité de biens fabriqués / quantité de carburant consommé et des émissions de gaz à effet de serre<br>The issue of energy has emerged as one of the greatest challenges facing the mankind. The search is on for finding alternative sources of energy that will replace fossil fuels as the primary source of energy. However, for the foreseeable future, fossil fuels will remain the main source of energy. Therefore, it is of paramount importance to devise methodologies for more rational use of energy in all walks of human life. In the industrial perspective, the deployment of site utility system (generally CHP plants) provides a great potential source for energy savings. However, the management of such type of industrial units is traditionally carried out using sequential three step approach: scheduling of the production plant, estimation of the utility needs of production plant and finally scheduling of the site utility system. In this kind of approach, all the focus is placed on the production plant and the utility system is treated as its subsidiary. To improve the decision-making process, this thesis proposes an integrated approach which addresses this imbalance by carrying out simultaneous and coherent scheduling of batch production plant and site utility system. The proposed methodology relies on discrete time modeling and uses Mixed Integer Linear Programming (MILP). Moreover, to permit an efficient and generic formulation of various kinds of industrial problems, a new scheduling framework called Extended Resource Task Network (ERTN) has been developed. The ERTN framework (an extension of existing RTN framework) allows for accurate representation and scheduling of any type of production plant and any type of site utility system. The results show that the integrated approach leads to better synchronization between production plant and site utility system. Thereby, the integrated approach leads to significant reduction in energy costs and decrease in harmful gas emissions
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STRIPPOLI, LAURA. "Transposon-based technology enhances the generation of stable and high-producing CHO clones for industrial production of recombinant proteins and antibodies." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2015. http://hdl.handle.net/10281/68384.
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Proteine ricombinanti e anticorpi sono reagenti chiave per lo sviluppo di saggi immunodiagnostici. Tuttavia proteine che hanno modifiche post-transcrizionali complesse o più subunità, come gli anticorpi, sono raramente espresse in microrganismi. Infatti, per ottenere una corretta conformazione sono necessarie le modifiche post-transcrizionali tipiche delle cellule di mammifero. Negli ultimi anni sono stati sviluppati diversi metodi per il trasferimento genico, ma nonostante ciò è ancora difficile ottenere linee cellulari stabili e altamente produttive. Le strategie convenzionali si basano sull’integrazione spontanea di DNA episomale e perciò hanno una bassa efficienza di generazione di cloni e, spesso, una scarsa espressione del transgene a causa di effetti posizionali e del silenziamento di transgeni integrati come concatameri.Per superare questi limiti, ho valutato le potenzialità dell’utilizzo dei trasposoni piggyBac come nuovo metodo per veicolare transgeni. I sistemi basati sui trasposoni sfruttano la capacità dell’enzima trasposasi di catalizzare in trans l’integrazione del transgene in regioni genomiche attivamente trascritte. Per studiare questo sistema e confrontarlo con i vettori tradizionali ho clonato, in entrambi i plasmidi, due proteine modello, il fibroblast growth factor 23 (hFGF23) e un anticorpo ricombinante per la produzione in cellule CHO (chinese hamster ovary). I risultati ottenuti hanno dimostrato che la trasposizione aumenta la frequenza di generazione di linee cellulari stabili di circa 15 volte rispetto alla trasfezione di plasmidi standard. Inoltre, lo screening dei cloni è facilitato perchè la generazione di linee cellulari stabili è più rapida e la frequenza di cloni produttivi è maggiore. Infine ho dimostrato che la frequenza di cloni altamente produttivi è influenzata dalla forza del promotore clonato nel PB. Grazie a questo sistema, ho generato linee cellulari in grado di esprimere l’hFGF23 con una resa media di 35 mg/L in colture batch. La proteina purificata è stata correttamente riconosciuta da un test immunodiagnostico (DiaSorin) con risultati paragonabili ad un hFGF23 ricombinante commerciale. In seguito ho valutato l'utilizzo del sistema dei trasposoni per la generazione di anticorpi ricombinanti. Dopo l'identificazione delle regioni variabili della catena pesante (HC) e leggera (LC) di una immunoglobulina IgG2a murina sviluppata con la tecnologia dell’ibridoma, ho generato un anticorpo chimerico IgG1. A tal scopo, le sequenze variabili sono state clonate a monte delle sequenze costanti della rispettive catene e poi inserite o in vettori standard o nei trasposoni per la co-espressione in cellule CHO. I risultati ottenuti hanno evidenziato i vantaggi dell’uso del sistema dei trasposoni PB per integrare stabilmente due transgeni con un’unica trasfezione, mantenendo un rapporto molare appropriato come richiesto per la corretta formazione di anticorpi (sbilanciato a favore di LC). Le integrazioni casuali, tipiche delle trasfezioni con plasmidi standard, hanno creato difficoltà nella co-espressione dei transgeni, infatti l’80% dei cloni aveva una produttività molto bassa. Al contrario, le integrazioni mediate dalla trasposasi PB hanno aumentato il numero di cloni altamente produttivi. Infine, l'immunoglobulina IgG1 chimerica è stata purificata e ha mostrato affinità e prestazioni immunochimiche paragonabili a quelle dell'anticorpo IgG2a prodotto dall’ibridoma originale, confermando le potenzialità del nostro sistema. In conclusione, questa tesi dimostra che il sistema basato sui trasposoni PB può essere considerato una rapida ed efficace alternativa al metodo standard per la generazione di linee cellulari stabili capaci di produrre alte rese di reagenti critici per applicazioni diagnostiche.<br>Recombinant proteins and antibodies are the key reagents for development of diagnostic immunoassays. Recombinant proteins are commonly produced in both prokaryotic and eukaryotic microorganism because they allow high productivity with rapidity and low costs.
However, complex proteins that contain posttranslational modifications, several disulphide bonds or multiple subunits, such as antibodies, are challenging to be expressed in these hosts. Indeed, to obtain properly folded and functional complex biomolecules it is required
the posttranscriptional metabolic machinery only available in mammalian cells. Although different approaches for gene transfer have been developed in the last 15 years, it is still difficult to obtain stable, high-producing cell lines for industrial applications. Conventional
methods, based on spontaneous integration of episomal DNA, often result in low efficiency of clone establishment and in low transgene expression mainly due to plasmid concatemers silencing and/or positional effects. To overcome these limitations, in my thesis project, I
evaluated the potentiality of using an improved PiggyBac (PB) transposon system as new molecular tool for transgene delivery. Transposon-based approaches rely on the ability of transposase enzyme to catalyze single transgene integration into actively transcribed
regions of genome. In order to assess the suitability of PB transposon vectors compared to conventional methods, two different model proteins, the human fibroblast growth factor 23 (hFGF23) and one mouse recombinant antibody, have been cloned into both expression
plasmids and produced in CHO (Chinese Hamster Ovary) cells.
A preliminary comparison between the two expression systems demonstrated that PB transposition increased the frequency of stable cell lines generation up to 10-15 fold compared to standard plasmid transfection. Cell lines establishment was faster and the frequency of high-producing clones was enhanced, thus reducing the extent of clones screening to recover the best performing cell lines. In addition, I also evaluated that changing PB promoter strength affected the frequency of high-producing clones. Taking advantages from these results, I was able to generate CHO cell lines expressing hFGF23 protein with an average yield of 35 mg/L in batch culture. The obtained purified protein was correctly detected by an automated chemiluminescence immunoassay (DiaSorin) with results comparable to a commercial available mammalian recombinant hFGF23 protein and it resulted biologically active when tested in a cell proliferation assay.
Then I evaluated the application of PB transposon system for the generation of recombinant antibodies. After identification of heavy and light chain variable regions from an IgG2a mouse immunoglobulin developed by hybridoma technology, I have generated a
chimeric IgG1 antibody by cloning mouse variable regions upstream of mouse heavy and light chain constant sequences. The ensuing full length sequences were cloned into standard vectors and transposon for co-expression in CHO cells. In these set of experiments, my results highlighted the advantages of using PB transposon to stably integrate, in one transfection step, two different transgenes with an appropriate molar ratio (light/heavy chain ratio unbalanced in favour of light chian), as required for proper antibody assembly. Random integrations, typical of standard plasmid transfections, showed difficulties in fine tuning of co-transfected transgenes expression, resulting in 80% of clones with very low productivity. In contrast, integrations mediated by PB transposase increased the number of high producing clones. The chimeric IgG1 immunoglobulin, purified from the best producing clone, showed affinity and immunochemical performances comparable to
that of the parental hybridoma IgG2a antibody, confirming the potentiality of our system. In conclusion, my work demonstrates that the PB transposon system is a quick and powerful alternative to standard method for generation of stable, high-producing recombinant mammalian cell lines to generate critical reagents useful for diagnostic applications.
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Saunders, Fay Louise. "An investigation into the role of chromatin modifying elements on the production of recombinant antibodies from CHO Cells." Thesis, Open University, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.533111.
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Bydén, William, and David Fridlund. "Carbon Negative Heat and Power with Biochar Production : An Economic Analysis of a Combined Pyrolysis and CHP plant." Thesis, KTH, Skolan för industriell teknik och management (ITM), 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-279608.
Full textAbstract:
On the fourth of November 2016, The Paris Agreement entered into force, stating that nations worldwide should pursue efforts to limit the global temperature increase to 1,5 °C. Since then, the Intergovernmental Panel on Climate Change has specified that carbon dioxide removal, such as biochar sequestration, is necessary to achieve this goal. Biochar is a solid and porous material, rich in carbon, produced when biomass undergoes a process called pyrolysis and can, if buried in soil, sequester carbon for hundreds or even thousands of years while at the same time acting as a soil amendment. When biomass is pyrolyzed to produce biochar, a pyrolysis gas is also produced, which can be used to generate both heat and electricity. This thesis investigates if constructing and operating a plant, called a combined pyrolysis and CHP plant, which combines biochar production with heat and electricity generation, could be economically feasible and thus be an effective method for carbon dioxide removal. The findings show that constructing and operating a combined pyrolysis and CHP plant can be economically feasible. However, the economic feasibility is greatly affected by the price of biochar as a soil amendment product. The biochar market is also an undeveloped market, making price estimates of biochar far from accurate. Another factor that could significantly affect the economic feasibility of the plant is the fraction of carbon in biochar, which can be accounted for as sequestered. A higher fraction means that significantly more governmental support can be given to provide financing of the plant as well as potential revenue from carbon credits could increase. The capital cost of constructing the plant is also a factor with high uncertainty, which has a substantial effect on the economic feasibility. From this thesis, it is concluded that more research regarding the biochar market, as well as the capital costs of constructing the plant, is needed. More research could further ascertain whether or not the plant could be economically feasible and thus, an effective method for carbon dioxide removal.<br>Den fjärde november 2016 trädde Parisavtalet i kraft vilket uppgav att länder över hela världen ska sträva efter att begränsa den globala temperaturökningen till 1,5 grader Celsius. I enlighet med detta mål har FN:s mellanstatliga klimatpanel, IPCC, specificerat att koldioxidavlägsnande åtgärder, såsom kolinlagring genom produktion av biokol, är nödvändigt. Biokol är ett fast och poröst material, rikt på kol, som produceras när biomassa genomgår en process som kallas pyrolys. Om biokol blandas ner i jord kan det binda kol i hundratals eller tusentals år samtidigt som det fungerar som jordförbättrare. När biomassa pyrolyseras produceras också en pyrolysgas som kan användas för att generera värme och elektricitet. Det här examensarbetet undersöker om det kan vara ekonomiskt genomförbart att bygga och driva en anläggning, benämnd en kombinerad pyrolys- och kraftvärmeanläggning, som kombinerar biokolsproduktion med värme- och elproduktion för att avlägsna koldioxid från atmosfären. Resultaten från arbetet visar att det kan vara ekonomiskt genomförbart att bygga och driva en kombinerad pyrolys- och kraftvärmeanläggning. Den ekonomiska genomförbarheten påverkas dock i hög grad av priset på biokol som jordförbättringsprodukt. Marknaden för biokol är dessutom outvecklad vilket gör att priset för biokol osäkert. En annan faktor som i hög grad skulle kunna påverka den ekonomiska genomförbarheten för anläggningen är andelen kol i biokol som kan anses vara lagrad. En högre andel innebär att betydligt mer statligt stöd kan ges för att finansiera anläggningen samt att potentiella intäkter från kolkrediter kan öka. Kapitalkostnaderna för att bygga anläggningen är också en faktor med hög osäkerhet som har stor effekt på den ekonomiska genomförbarheten. Från detta examensarbete dras slutsatsen att mer forskning kring biokolsmarknaden samt kring kapitalkostnaderna för att bygga anläggningen behövs. Detta behövs för att ytterligare fastställa den ekonomiska genomförbarheten hos en sådan anläggning för att avlägsna koldioxid från atmosfären.