Thèses sur le sujet « P-length »

Thanks to the Cambridge Structural Database, in this thesis work has been selected several uranyl’s ion crystal structures, which share interactions between uranyl’s oxygen and block p elements, or hydrogen. These interactions belong to hydrogen bond, chalcogen and halogen bond or, in a more generic way, short contact interactions. In order to select the structures, the research fields were limited for certain elements to a value within their Van der Waals peak. It was evaluated the influence that these interactions provide to the uranyl’s ion bond length (U=Oyl) from two points of view: a) by considering the type of interacting element and b) by considering the type of donor atom in equatorial position. The data collected were also used to verify the existence of a trend that correlates the interaction length, or nature of equatorial ligands, to the uranyl’s bond length. A comparation between the IR and Raman data, provided by the original works, completes the overview. In conclusion, the main synthetic routes to achieve the structures analysed in this research were highlighted.

Dissertação de Mestrado em Desenvolvimento e Perturbações da Linguagem na Criança
A Extensão Média do Enunciado (EME) é um índice que resulta do rácio entre o número de morfemas (EME-m) ou número de palavras (EME-p) e o número de enunciados produzidos pela criança. Este índice tem vindo a ser estudado e utilizado em diferentes países e línguas, e, apesar de muitos estudos o apontarem como um bom indicador de desenvolvimento gramatical e linguístico, outros são controversos, principalmente quando aplicados a línguas com morfologia flexional mais rica, como o caso do português. Dada a escassez de dados para o português europeu, confinados a duas faixas etárias, e atendendo às evidências de que a EME-m e a EME-p apresentam uma boa correlação, neste estudo procurou-se analisar a EME-p, dos três aos sete anos. Os principais objetivos da presente dissertação são verificar se a EME-p será um bom indicador de desenvolvimento gramatical e linguístico, através da sua correlação com a idade e analisando diferenças entre faixas etárias, entre contextos de discurso (narrativo e espontâneo) e o nível de escolaridade (pré-escolar e escolar). Participaram no estudo cinquenta crianças, monolingues do português europeu e com desenvolvimento típico de linguagem, a frequentar centros educativos do Concelho de Santa Comba Dão. Foram gravadas, em dois momentos, amostras de discurso, espontâneo e narrativo, perfazendo, pelo menos, cem enunciados, que, posteriormente, foram transcritos através do Software Computerized Language Analysis (CLAN), que também realizou, de forma automática, o cálculo da EME-p. Os resultados indicam uma associação forte entre a idade e a EME-p, apesar de não existirem diferenças entre todas as faixas etárias, e uma correlação positiva entre a EME-p e o desenvolvimento da linguagem de crianças monolingues do português europeu. O valor da EME-p em discurso narrativo é estatisticamente superior ao seu valor em discurso espontâneo e o grupo em idade pré-escolar apresentou menor desempenho do que o grupo escolar. Em suma, considera-se que a EME-p pode fornecer informação pertinente sobre o desenvolvimento expressivo morfossintático da criança, contudo não poderão ser considerados valores padrão nem se poderá utilizar este índice como critério de diagnóstico.
The Mean Length of Utterance (MLU) is an index that results from the ratio between the number of morphemes (MLUm) or number of words (MLUw) and the number of utterances produced by the child. This index has been studied and used in different countries and languages and although many studies tell us that it is a good grammatical and linguistic development indicator, others are controversial, especially when applied to languages with richer inflectional morphology, such as Portuguese. Given the lack of data for European Portuguese confined to two age groups, and given the evidence that MLUm and MLUw have a good correlation, in this study we tried to analyze the MLUw in a group from three to seven years old. The main objectives of this dissertation are to check if the MLUw is a good indicator of grammatical and linguistic development, verifying its correlation with age and analyzing differences between age groups, discourse contexts (narrative and spontaneous) and the level of education (pre -school and school-age). In this study participated fifty children. They all were monolingual speakers of European Portuguese with typical language development, attending educational centers of the municipality of Santa Comba Dão. Speech samples were recorded in two different moments, in spontaneous speech and narrative context, making at least an hundred utterances which were later transcribed through Computerized Language Analysis Program (CLAN) which also calculated automatically the MLUw. The results indicate a strong association between age and the MLUw, although there are no significant differences between all age groups, and a positive correlation between MLUw and the development of European Portuguese children. The value of the MLUw in narrative discourse is statistically higher than in spontaneous speech and the group of pre-school age showed lower performance than the school-age group. In short, it is considered that the MLUw can provide relevant information on child development of morphosyntactic expressive competence, but cannot be considered as normative data or for diagnostic criterion.

La tesi studia la relazione intercorrente tra le decisioni di product line length e le performance aziendali. Si esaminano le determinanti delle decisioni di product line length e si opera una review della letteratura che ha studiato il legame tra product line e performance. L'analisi empirica si focalizza su un'eccellenza del "made in Italy": la piastrella di ceramica.

There have been very few measurements of the total cross section for n-p scattering below 500 keV. In order to differentiate among NN potential models, improved cross section data between 20 and 600 keV are required. We measured the n-p and n-C total cross sections in this energy region by transmission; a collimated neutron beam was passed through CH2 and C samples and transmitted neutrons were detected by a BC-501A deuterated liquid scintillator. Cross sections were obtained by taking the ratios of normalized neutron yields with the samples in the beam and with no sample in the beam. Both better precision and larger range between 90 keV and 1.8 MeV results are presented. The parameters resulting from fitting effective range theory to the data for n-p scattering are in good agreement with parameters determined from previous fits.

Neurotrophins and their receptors are key molecules in the development of the
nervous system. Neurotrophin-3 binds preferentially to its high-affinity receptor
NTRK3, which exists in two major isoforms in humans, the full-length kinaseactive
form (150 kDa) and a truncated non-catalytic form (50 kDa). The two
variants show different 3'UTR regions, indicating that they might be differentially
regulated at the post-transcriptional level. In this work we explore how
microRNAs take part in the regulation of full-length and truncated NTRK3,
demonstrating that the two isoforms are targeted by different sets of microRNAs.
We analyze the physiological consequences of the overexpression of some of the
regulating microRNAs in human neuroblastoma cells. Finally, we provide
preliminary evidence for a possible involvement of miR-124 - a microRNA with no
putative target site in either NTRK3 isoform - in the control of the alternative
spicing of NTRK3 through the downregulation of the splicing repressor PTBP1.
Las neurotrofinas y sus receptores constituyen una familia de factores cruciales
para el desarrollo del sistema nervioso. La neurotrofina 3 ejerce su función
principalmente a través de una unión de gran afinidad al receptor NTRK3, del cual
se conocen dos isoformas principales, una larga de 150KDa con actividad de tipo
tirosina kinasa y una truncada de 50KDa sin dicha actividad. Estas dos isoformas
no comparten la misma región 3'UTR, lo que sugiere la existencia de una
regulación postranscripcional diferente. En el presente trabajo se ha explorado
como los microRNAs intervienen en la regulación de NTRK3, demostrando que las
dos isoformas son reguladas por diferentes miRNAs. Se han analizado las
consecuencias fisiológicas de la sobrexpresión de dichos microRNAs utilizando
células de neuroblastoma. Finalmente, se ha estudiado la posible implicación del
microRNA miR-124 en el control del splicing alternativo de NTRK3 a través de la
regulación de represor de splicing PTBP1.

碩士
國立高雄師範大學
數學研究所
86
A p-group G of order pn is said to be of maximal class if it has nilpotent class n-1. Most groups we consider here are p-groups of maximal class. The study of derived length m(p) of a p-group of maximal class is mostly contributed by N. Blackburn. In 1958, N. Blackburn showed that m(2)=2;m(3)=2;m(5)=3. In 1962, J.L. Alperin showed that "To every prime p there exist an integer m(p) such that if G is a p-group of maximal class then the derived length of G is at most m(p)". In this thesis, we shall study the case p = 7 and p=11.

The study of conjugated polymers, in particular PPV derivatives, continues to fascinate researchers both from the standpoint of developing new routes to control their structure and photophysical properties; this is also driven by the immense potential since this class of polymers has demonstrated in the context of various devices, such as LEDs, photovoltaics, FETs, etc. Also, there has been great interest in utilizing conjugated polymers in developing sensory devices. This thesis has examined a few interesting aspects that could be used to control the structure and consequently the photophysical properties of PPV derivatives. The first chapter of this thesis provides a brief introduction to conjugated polymers, with an emphasis on PPV based polymers, different synthetic methodologies for their preparation, previous attempts to obtain PPV with controlled conjugation length, and also a brief discussion of conjugated polymer nanoparticles (CPNs) and their preparation by various methods. The second chapter deals with the preparation of conjugated polymer (MEHPPV) nanoparticles by reprecipitation method and utilization of these nanoparticles in detection of nitro explosives in aqueous medium. Nanoparticles of MEHPPV with different sizes were prepared by a simple precipitation method from a THF solution into water. Although these nanoparticles were prepared from very hydrophobic MEHPPV, these nanoparticles were reasonably stable in aqueous medium, especially when their sizes were relatively small; their UV-visible and fluorescence spectra could be readily recorded using simple solution methods. The sizes could be controlled by varying the concentration of the polymer solution used. The CPNs are spherical particles as confirmed by atomic force microscopy (AFM). The emission maximum of the nanoparticles is red shifted compared to a solution of the polymer. The fluorescence spectrum of this aqueous nanoparticle dispersion exhibited very high sensitivity to electron-deficient aromatic compounds, in particular the explosive TNT; the CPNs were able to sense nanomolar concentrations of the explosives. Stern-Volmer constant (KSV) is higher for 2,4,6-trinitro toluene (TNT) than any other analytes studied. Among the different sized nanoparticles studied the bigger one showed highest quenching efficiency. Electron-deficient aromatic molecules were shown to quench the fluorescence of the nanoparticles, possibly by excited state electron transfer mechanism; this hypothesis was supported by quenching experiments carried out using a variety of nitro-aromatic molecules with varying reduction potentials, in addition to a few electron-rich aromatic molecules. A fairly good correlation between the quenching efficiency of the analyte and its reduction potential was noticed; however, in a few instances this correlation failed. This suggested that a second factor, namely the solubility of the analyte in water (its hydrophobicity) also is a key factor as this governs the tendency of the analyte to adsorb on the nanoparticle surface, which clearly is the first step in the quenching process. In the third chapter synthesis and characterization of MEHPPV with reduced conjugation length by utilizing the concept of conjugation breaking using non-coplanar entities are presented. MEHPPV with reduced conjugation length was prepared by incorporating non-coplanar entities, such as biphenyl and binaphthyl units, along the polymer backbone. Both Gilch and Witting-Horner methods were successfully utilized to prepare copolymers; the former approach permitted the variation of the level of the twisted comonomer incorporation, whereas the latter approach only provided an alternating copolymer. Although biphenyl based monomers could not be homopolymerized by Gilch method, it was possible to prepare copolymers using xylylene type comonomers. The polymers prepared by the Gilch method are random copolymers; the solubility decreases with increase in the amount of biphenyl incorporation, which was ascribed to the presence of a substantial fraction of longer conjugated segments in such random copolymers. The non-coplanar entities cause truncation of conjugation length in MEHPPV, as evident from their absorption spectra. The copolymers prepared via the Gilch method exhibited a blue shift of about 57 and 20 nm in the absorption and emission, respectively; while the alternating copolymers prepared by Wittig-Horner-Emmons method exhibited a larger blue-shift of about 84 and 54 nm clearly implying a significantly larger reduction in the conjugation length. The copolymers prepared by Wittig-Horner-Emmons method are alternating in nature and therefore leads to a greater reduction in conjugation length; this was evident from the substantially higher blue-shift in the absorption and fluorescence spectra. An interesting feature in the alternating copolymers is the distinct difference in the relative changes in the absorption and emission spectra of the biphenyl and binaphthyl containing copolymers, which appear to suggest in the latter case there is a greater extent of planarization of the excited state. Both these systems provided some useful insights into the various factors that govern the photophysical properties of this class of truncated conjugated polymers. Further examination of this aspect could reveal some other unique features of these copolymers. In the fourth chapter, an approach to prepare copolymer precursors to unsubstituted PPV that holds the potential to control conjugation length is described. The precursor copolymers were prepared by changing the monomer feed ratio of the two monomers, viz. dithiocarbamate (DTC) and xanthate, using the Gilch copolymerization to generate the precursors having varying extents of DTC and xanthate groups. The percentage composition of the precursor copolymers was calculated using 1H NMR and compared with the values calculated from thermogram; the copolymer composition varies linearly with monomers feed suggesting that any desired composition can be readily accessed. Thermogravimetric analysis (TGA) of the precursors, as a preliminary study to examine the possibility of selective elimination of one of these groups to generate conjugated polymers with varying conjugation lengths, demonstrates that a certain level of selectivity in thermal elimination can be achieved because of the distinctly different thermal labilities of the xanthate and DTC groups. These studies clearly suggest that fine-tuning of the thermally eliminatable groups, specifically using xanthate and DTC, could serve as a useful approach to vary the conjugation length of unsubstituted PPVs, which could have important implication in device fabrication. Clearly further work is needed to characterize the selectively eliminated polymers using other spectroscopic methods, such as UV-visible and fluorescence, before device work could be taken up.

碩士
國立高雄師範大學
電子工程學系
107
In this work, P-type Tri-Gate FinFETs were investigated by using hot carrier effect (HCE) with different work functions, channel length and fin numbers. Under thermal equilibrium, the larger band bending could be found with the increasing of metal work function thus cause the increasing of saturation current and reduction of threshold voltage. For the high work function device, the increasing of metal ions in the gate electrode would enhance the probability of interface traps generation under hot carrier injection. As a result, the degradation of reliability is more significant. On the other hand, the increased saturation current and the reduced threshold voltage could be observed with the reduction of channel length. By the way, the worse reliability for the short channel device is suggested due to the enhanced lateral electric field thus cause more interface traps generated after hot carrier stress. With the increasing of fin numbers, the more severe compressive stress caused by Contact Etch Stop Layer (CESL) would enhance hole mobility. For the short channel device, the multi-fin device shows poor reliability. On the other hand, for the long-channel devices, the multi-fin devices show better reliability than the single-fin sample. It is suggested that the effect of compressive stress is more obvious for the short channel device.

In vivo production of medium-chain-length poly(3-hydroxyalkanoates) (MCL-PHA) containing a side chain carboxyl group from azelaic acid (AzA), a nine-carbon α,ω-dicarboxylic acid, was investigated using Pseudomonas citronellolis DSM 50332 in a phosphate (P)-limited chemostat. Co-feeding with nonanoic acid (NA) and inhibition of β-oxidation with acrylic acid (AA) were strategies that were used to stimulate the incorporation of carboxylated monomers, but both were unsuccessful. P. citronellolis DSM50332 was capable of growing on AzA as a sole source of carbon and energy, indicating that enzymes in β-oxidation utilized AzA and its derivatives. However, the MCL-PHA produced from AzA comprised 3-hydroxyoctanoate (C8) and 3-hydroxydecanoate (C10) monomers, which was consistent with precursor supplied via the de novo fatty acid biosynthesis pathway. This evidence suggests that one or more of 3-ketoacyl-CoA reductase (FabG), enoyl-CoA hydratase (PhaJ) and PHA synthase (PhaC) of this organism do not have the low specificity required to utilize a carboxylated substrate. Future work involving mutations may broaden the substrate specificity of these key enzymes to overcome this obstacle. Two-stage high-cell density carbon (C)-limited chemostat cultivation of P. putida KT2440 was examined for MCL-PHA production from nonanoic acid (NA) at high intracellular polymer content and volumetric productivity. Growth conditions stimulating good PHA production were first established in single-stage chemostat, which yielded 63.1 wt% PHA containing 90 mol% C9 units and a productivity of 1.52 g L-1h-1 at a dilution rate of 0.30 h-1. This productivity was higher than any value reported in literature for continuous MCL-PHA production systems and comparable to the upper range of fed-batch results. Two-stage production yielded promising results, notably the increase in polymer content from the first to second stage. However, complications involving foaming and an unexplained decline in PHA content adversely affected system performance. The best PHA content and overall productivity were 58.5 wt% and 0.76 g L-1h-1, respectively. Nonetheless, the results demonstrate the potential to achieve high PHA content without the need for pure oxygen at high dilution rates, warranting further investigation focusing on the optimization of growth conditions.
Thesis (Master, Chemical Engineering) -- Queen's University, 2011-12-19 15:48:21.808

碩士
明新科技大學
電子工程系碩士班
106
In today's nano-process era, component sizes are getting smaller and smaller, and electronic products are required to have high performance, low cost, and small size. In order to achieve the above requirements, it is imperative to find better components than the conventional two-dimensional MOSFETs. Here we find three-dimensional fin field-effect transistors (FinFETs). In deep nanometer applications, It is a very good component, but due to the large amount of manufacturing, many details need attention so as not to affect the performance and yield of IC products. FinFETs have been widely used in advanced nano-processes, such as TSMC, Intel, and Samsung, which are the three most focused manufacturing companies in the world. These companies are using FinFET components for their maximum performance. In the semiconductor device manufacturing process, the FinFET has a relatively good control over the channel compared with the conventional transistor, which can effectively reduce the leakage current and improve the short-channel effect. In our experimental measurement study, we used the p-type FinFET (pFinFET) as the main DUT. Use a fixed frontal (layout) channel width W=0.115μm, but the channel length L is different, including (0.12μm, 0.16μm, 0.24μm, 0.5μm, 2μm, 10μm) Make measurements. Observe Drain-induced barrier lowering (DIBL) and source/sink during measurements at different temperatures or at different source/drain extensions (LSDE) What are the different changes in the Punch-through effect? Measurements have revealed that for pFinFETs, the length of the components is reduced, DIBL is significantly increased, and the penetration effect is also significant. At increasing temperatures, the strong DIBL effect at LSDE = 60 nm was found to be 75oC rather than 125oC. In addition, at room temperature, the DIBL and penetration effects of LSDE=60nm and 160nm are compared. At LSDE=60nm, there is no orderly trend change when there is a regular LSDE=160nm, which may also be larger with LSDE=160nm. As a result, the resistance of the source/drain is more difficult to control evenly than to affect the two effects.

碩士
中原大學
化學研究所
101
Glycolipid compounds GPS-1 (18), GS (18), and GO (18) synthesized in our laboratory , we found that GPS-3 (18) than the other two high GS (18) and GO (18). After comparing the three structural differences, we GPS-1 (18) is the lead compound (lead compound), Synthesized a series ofsaturated fatty acids with differrent carbon number of glycolipid compoundsGPS-1 series, explore a systematic relationship between the structure andbiological activity (structure-acti- vety relationship, SAR). GPS-1 series of compounds is N-acetyl glucosamine (glucosamine) as a starting material, via a plurality of oxide acetylation (per-O-acetylation), cyclization reaction (cyclization), glycosylation reaction (glycosylation) , N-tertiary-butoxycarbonyl-amidation reaction (amidization) and the hydrogenation reaction (hydrogenation) and other five steps to prepare the compound GS-5.Compound GS-5 and then with FMOC-L-proline (Fmoc-L-Proline) conductedamidation reaction (amidization), then de 9-fluorenyl methoxycarbonyl(fluorenylmethyloxycarbonyl, Fmoc) reacts with different unsaturated carboxylic acid amide having a carbon number of the amination reaction, and thedeacetylation reaction to tert-butoxycarbonyl (t-butyloxycarbonyl, Boc) reaction, the five-step reaction to obtain the target GPS-1. Activity test parts: for a single dose (10 μM) of the activity test, we found thispart of a series of compounds has a significant inhibitory effect, but some with no apparent biological significance, and not because of the length of the carbon chain showed a correlation , visibility, influence the activity of the carbon chain is not the main reason. In addition, we have also done a multiple dose (10,20,30 μM) activity test and found that this series of compounds at concentrationsincrease, the correct time will increase its inhibitory activity.

Different oil-containing substrates, namely, used cooking oil (UCO), fatty acids-byproduct from biodiesel production (FAB) and olive oil deodorizer distillate (OODD) were tested as inexpensive carbon sources for the production of polyhydroxyalkanoates (PHA) using twelve bacterial strains, in batch experiments. The OODD and FAB were exploited for the first time as alternative substrates for PHA production. Among the tested bacterial strains, Cupriavidus necator and Pseudomonas resinovorans exhibited the most promising results, producing poly-3-hydroxybutyrate, P(3HB), form UCO and OODD and mcl-PHA mainly composed of 3-hydroxyoctanoate (3HO) and 3-hydroxydecanoate (3HD) monomers from OODD, respectively. Afterwards, these bacterial strains were cultivated in bioreactor. C. necator were cultivated in bioreactor using UCO as carbon source. Different feeding strategies were tested for the bioreactor cultivation of C. necator, namely, batch, exponential feeding and DO-stat mode. The highest overall PHA productivity (12.6±0.78 g L-1 day-1) was obtained using DO-stat mode. Apparently, the different feeding regimes had no impact on polymer thermal properties. However, differences in polymer‟s molecular mass distribution were observed. C. necator was also tested in batch and fed-batch modes using a different type of oil-containing substrate, extracted from spent coffee grounds (SCG) by super critical carbon dioxide (sc-CO2). Under fed-batch mode (DO-stat), the overall PHA productivity were 4.7 g L-1 day-1 with a storage yield of 0.77 g g-1. Results showed that SCG can be a bioresource for production of PHA with interesting properties. Furthermore, P. resinovorans was cultivated using OODD as substrate in bioreactor under fed-batch mode (pulse feeding regime). The polymer was highly amorphous, as shown by its low crystallinity of 6±0.2%, with low melting and glass transition temperatures of 36±1.2 and -16±0.8 ºC, respectively. Due to its sticky behavior at room temperature, adhesiveness and mechanical properties were also studied. Its shear bond strength for wood (67±9.4 kPa) and glass (65±7.3 kPa) suggests it may be used for the development of biobased glues. Bioreactor operation and monitoring with oil-containing substrates is very challenging, since this substrate is water immiscible. Thus, near-infrared spectroscopy (NIR) was implemented for online monitoring of the C. necator cultivation with UCO, using a transflectance probe. Partial least squares (PLS) regression was applied to relate NIR spectra with biomass, UCO and PHA concentrations in the broth. The NIR predictions were compared with values obtained by offline reference methods. Prediction errors to these parameters were 1.18 g L-1, 2.37 g L-1 and 1.58 g L-1 for biomass, UCO and PHA, respectively, which indicates the suitability of the NIR spectroscopy method for online monitoring and as a method to assist bioreactor control. UCO and OODD are low cost substrates with potential to be used in PHA batch and fed-batch production. The use of NIR in this bioprocess also opened an opportunity for optimization and control of PHA production process.

Skin tissue engineering represents an important tool in various fields such as cosmetic testing and regenerative medicine. The possibility of reproducing in vitro the fundamental properties of in vivo skin introduces new opportunities for creating knowledge. One of the techniques employed is the production of scaffolds to harbor cells, allowing for their proliferation and differentiation into functional tissues. These scaffolds must have certain characteristics, such as biocompatibility, biodegradability, appropriate physico-chemical and mechanical properties, ease of production and cost-effectiveness, all dependent on the material chosen. Thus, polyhydroxyalkanoates (PHAs) represent a potential scaffold material due to all of their relevant characteristics for biomedical applications. Also, the exopolysaccharide FucoPol can be incorporated with PHA as a blend or coating, possibly introducing bioactivity to the scaffolds. Therefore, the aim of this work was the production of scaffolds for reconstruction of human dermis, through the emulsion templating method, resulting in porous constructs that were tested with human dermal fibroblasts (HDFn). The scaffolds obtained in this work were based on P(HBHVHHx), a PHA composed of 51 wt% 3-hydroxybutyrate, 18 wt% 3-hydroxyvalerate and 31 wt% 3-hydroxyhexanoate, and had a porous structure with some interconnected pores. The scaffolds produced through emulsion with water had mechanical, thermal and physical properties comparable with the scaffolds produced through emulsion with FucoPol solution, both of them suitable for skin tissue engineering. These scaffolds were tested with HDFn to assess their bioactivity. In both the cells were able to adhere, proliferate and differentiate, showing possible extracellular matrix (ECM) deposition. The eight-day assay revealed increased cellular growth and organized ECM deposition in the scaffolds with FucoPol compared to the ones without. The fourteen-day assay confirmed pore geometry as the limiting factor for the full invasion of the scaffolds. This work demonstrated the potential of naturally derived P(HBHVHHx)/FucoPol scaffolds for the reconstruction of human dermis.
A engenharia de tecidos da pele representa uma ferramenta importante em várias áreas, como a cosmética e a medicina regenerativa. A possibilidade de reproduzir in vitro as propriedades fundamentais da pele in vivo, introduz oportunidades para criar conhecimento. Uma das técnicas aplicada é o desenvolvimento de scaffolds para cultura celular, permitindo a sua proliferação e diferenciação em tecidos funcionais. Estes scaffolds devem possuir certas características, tais como biocompatibilidade, biodegradibilidade, propriedades físico-químicas e mecânicas apropriadas, facilidade de produção e custo-eficácia, todas dependentes do material escolhido. Assim, os polihidroxialcanoatos (PHAs) representam um potencial material para este efeito, devido a todas as suas características relevantes para aplicações biomédicas. Adicionalmente, o exopolissacárido FucoPol pode ser incorporado como uma mistura ou revestimento do scaffold de PHA, possivelmente introduzindo bioatividade. O objetivo deste trabalho foi produzir scaffolds para reconstrução da derme humana, através da técnica de emulsão, resultando em estruturas porosas que foram testadas in vitro com fibroblastos humanos (HDFn). Os scaffolds de PHA produzidos, com composição monomérica 51 wt% 3-hidroxibutirato, 18 wt% 3-hidroxivalerato e 31 wt% 3-hidroxihexanoato, resultaram numa estrutura porosa com alguns poros interconectados. A emulsão com água resultou em scaffolds com propriedades mecânicas, térmicas e físicas comparáveis aos obtidos através de emulsão com solução aquosa de FucoPol, sendo ambos adequados para a aplicação pretendida. Estes scaffolds foram testados com HDFn para avaliar a bioactividade. Em ambos as células conseguiram aderir, proliferar e diferenciar, com possível deposição de matriz extracelular (ECM). O ensaio de oito dias revelou um aumento no crescimento celular e deposição organizada de ECM nos scaffolds com FucoPol em detrimento dos scaffolds sem FucoPol. O ensaio de catorze dias confirmou a geometria dos poros como sendo o fator limitante para a invasão completa dos scaffolds. Este trabalho demonstrou o potencial de scaffolds P(HBHVHHx)/FucoPol para a reconstrução de derme humana.

Diversos estudos têm demonstrado que o nascimento pré-termo pode levar a alterações no desenvolvimento neurológico e a consequentes compromissos, nomeadamente do processamento e desenvolvimento linguístico. O presente estudo visa investigar se as crianças de nascimento muito prematuro a prematuro ligeiro (28 a 36 semanas) apresentam valores de Extensão Média do Enunciado em palavras (EME-p) mais baixos do que os considerados de referência aos 4 e 5 anos. Pretende-se também verificar no grupo de crianças prematuras se o número de semanas gestacionais e o peso à nascença influenciam os valores da EME-p e se existem diferenças condicionadas pelo género. Participaram no estudo 19 crianças prematuras (9 rapazes e 10 raparigas) matriculadas em jardins-de-infância da área da Grande Lisboa. O discurso destas crianças foi gravado durante 30 minutos e posteriormente transcrito para o software ELAN 4.1.2 para ser devidamente analisado. Verificou-se que os valores da EME-p de crianças prematuras são inferiores aos valores de referência aos 4 e 5 anos. Tanto o tempo de gestação como o peso à nascença se correlacionam de forma positiva e significativa com a EME-p. Não foram verificadas diferenças condicionadas pelo género nem pela escolaridade dos pais.
Several studies have shown that preterm birth can lead to abnormal neurological development that often leads to a compromise of processing and language development. Some studies also show that factors such as birth weight, parents' education and gender can significantly influence the language development of preterm infants. This work aims to verify whether children from very preterm birth to late preterm birth (28-36 weeks) present values of Mean Length of Utterance in words (MLU-w) lower than those considered in reference to the 4 and 5 years. We also intend to verify the group of premature children is the number of gestational weeks and birth weight influence the values of MLU-w and if there are differences conditioned by gender. Participated in this study 19 premature infants (9 boys and 10 girls) enrolled in kindergartens of the Greater Lisbon area. The speech of these children was recorded for 30 minutes and subsequently transcribed for ELAN 4.1.2 software to be properly analyzed. It was found that the values of MLU-w of preterm infants are lower than the reference values at 4 and 5 years. Both gestational age as birth weight correlated positively and significantly with the MLU-w. No differences conditioned by gender or by parental education were found.