Добірка наукової літератури з теми "COFI study"

Оформте джерело за APA, MLA, Chicago, Harvard та іншими стилями

Оберіть тип джерела:

Ознайомтеся зі списками актуальних статей, книг, дисертацій, тез та інших наукових джерел на тему "COFI study".

Біля кожної праці в переліку літератури доступна кнопка «Додати до бібліографії». Скористайтеся нею – і ми автоматично оформимо бібліографічне посилання на обрану працю в потрібному вам стилі цитування: APA, MLA, «Гарвард», «Чикаго», «Ванкувер» тощо.

Також ви можете завантажити повний текст наукової публікації у форматі «.pdf» та прочитати онлайн анотацію до роботи, якщо відповідні параметри наявні в метаданих.

Статті в журналах з теми "COFI study"

1

Rêgo, Carla, Luís Pereira-da-Silva, and Ricardo Ferreira. "CoFI - Consenso Sobre Fórmulas Infantis: A Opinião de Peritos Portugueses sobre a Sua Composição e Indicações." Acta Médica Portuguesa 31, no. 12 (December 28, 2018): 754. http://dx.doi.org/10.20344/amp.10620.

Повний текст джерела
Анотація:
Introduction: Breastfeeding has unique health benefits. Exclusive breastfeeding is recommended during the first six months of life and should be maintained during complementary feeding. Alternatively, infant formulas, which are designed to mimic human breastmilk to promote similar metabolic and growth profiles, can be used. This study aimed to assess the opinion of Portuguese paediatricians with expertise in nutrition on the composition, benefits and indications of commercialised infant formulas.Material and Methods: A survey based on the Delphi method with application of a questionnaire developed by a scientific committee was issued to a panel of paediatricians with expertise in nutrition. An initial questionnaire that included 65 items covering 11 areas was administered in two rounds.Results: Twenty-one experts participated, and the final response rate was 87.5%. The panel was in agreement in 68.3% of the enquired items, namely that infant formulas should be used only when breastfeeding is not possible. Notwithstanding, the opinion of the panel was heterogeneous on a number of issues, particularly those related to the advantages and indications of ‘special’ or modified infant formulas (partially hydrolysed formulas and anti-colic, anti-constipation and anti-regurgitation formulas) and of young child formulas (‘growing-up formulas’).Discussion: A wide consensus was recorded on the nutritional quality, food safety and indications attributed to commercialized infant formulas.Conclusion: The opinion of Portuguese experts was consensual in most of the enquired topics. The absence of consensus was mostly related to issues that remain under debate in the literature and lack robust scientific evidence.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Kawahara, Kazuki, Hiroya Oki, Shunsuke Fukakusa, Takahiro Maruno, Yuji Kobayashi, Daisuke Motooka, Tooru Taniguchi, et al. "Cloning, expression, purification, crystallization and X-ray crystallographic analysis of CofB, the minor pilin subunit of CFA/III from human enterotoxigenicEscherichia coli." Acta Crystallographica Section F Structural Biology Communications 71, no. 6 (May 20, 2015): 663–67. http://dx.doi.org/10.1107/s2053230x15005890.

Повний текст джерела
Анотація:
Colonization factor antigen III (CFA/III) is one of the virulence factors of human enterotoxigenicEscherichia coli(ETEC) that forms the long, thin, proteinaceous fibres of type IV pili through assembly of its major and minor subunits CofA and CofB, respectively. The crystal structure of CofA has recently been reported; however, the lack of structural information for CofB, the largest among the known type IV pilin subunits, hampers a comprehensive understanding of CFA/III pili. In this study, constructs of wild-type CofB with an N-terminal truncation and the corresponding SeMet derivative were cloned, expressed, purified and crystallized. The crystals belonged to the rhombohedral space groupR32, with unit-cell parametersa=b= 103.97,c= 364.57 Å for the wild-type construct anda=b= 103.47,c= 362.08 Å for the SeMet-derivatized form. Although the diffraction quality of these crystals was initially very poor, dehydration of the crystals substantially improved the resolution limit from ∼4.0 to ∼2.0 Å. The initial phase was solved by the single-wavelength anomalous dispersion (SAD) method using a dehydrated SeMet CofB crystal, which resulted in an interpretable electron-density map.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Miglietta, E., A. Lasalvia, P. Sara, G. Zanatta, S. Zoppei, G. Dimitri, C. Comacchio, et al. "Admission to In-patient Psychiatric Care in the Veneto Region (Italy), Specialisation vs. Personal Continuity of Care Approach. Preliminary Findings from the COFI Study-Italian Sites." European Psychiatry 41, S1 (April 2017): S619. http://dx.doi.org/10.1016/j.eurpsy.2017.01.992.

Повний текст джерела
Анотація:
IntroductionIn Italy, considerable variations exist in the organisation of out- and in-patient mental health care. One main issue is whether to prioritise specialisation (distinct clinicians for inpatient and outpatient care) or personal continuity of care (same primary clinician for a given patient within the two settings).AimsTo study the use of psychiatric in-patient units in the Veneto region (Italy) and to evaluate differences between personal continuity of care and specialization systems.MethodsStudy conducted in the context of the COFI, multisite naturalistic EU-funded research aiming to compare the two care approaches in 5 European countries. In Italy, baseline data collection was carried out in 14 in-patient units. Data on hospitalisation, diagnosis, severity of the illness (Clinical Global Impression Scale- CGI) and patients’ appraisal of inpatient care (Client Assessment of Treatment Scale- CAT) were collected.ResultsOverall, 1118 patients were assessed. Most frequent diagnostic categories were mood (41.6%) and psychotic (38.3%) disorders, while anxiety disorders were less represented (11.9%). The majority of patients were at least at their second admission (69.4%) and had been voluntary admitted (91.5%). Length of stay and CGI scores were significantly higher for patients with mood and psychotic disorders. No difference in CGI score between the two systems was found. Patients in the continuity of care systems reported higher level of satisfaction with initial treatment and longer hospital stay (P < .001).ConclusionsThese preliminary findings suggest higher service satisfaction for personal continuity system, possibly reflecting a more individualised and comprehensive focus on the patient's needs, rather than on symptoms reduction only.Disclosure of interestThe authors have not supplied their declaration of competing interest.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Miller, Anastasia. "Emergency medical service personnel injury and fatality in the United States." Journal of Epidemiological Research 4, no. 2 (May 23, 2018): 9. http://dx.doi.org/10.5430/jer.v4n2p9.

Повний текст джерела
Анотація:
Introduction: Emergency Medical Services (EMS) personnel comprise an intricate part of the public safety net in the US. The purpose of this study was to synthesize data sources to understand the major workplace dangers facing EMS providers. Methods: This study examined four data sources: The BLS Census of Fatal Occupational Injuries (CFOI), BLS Survey of Occupational Injuries and Illnesses (SOII), Firefighter Fatalities and Statistics from USFA, and the EMS Voluntary Event Notification Tool (E.V.E.N.T.). Characteristics of the most common causes of injury and fatalities were described and compared. Results: SOII reports covered 13 years and 64,780 nonfatal reported cases. COFI covered 12 years and 149 fatalities. 111 fatalities from the USFA dataset who had been identified as EMS in some manner in their rank between 2003-2016 were inspected. 21 cases where a firefighter died in the course of providing EMS/patient care were also identified and discussed. All events submitted to E.V.E.N.T. were read and categorized. 214 events were identified as near-miss EMS provider injuries and included in the study. Conclusions: The biggest mortal threat to private EMS personnel is vehicular incidents. Among firefighters/EMTs Heart Attacks was the most common nature of death. The biggest nonfatal concerns are violence, slips, trips, and falls, and overexertion in addition to vehicular incidents. Most violent events were the result of a patient with a Temporarily Altered Mental Status. There is clearly a need for further research to develop evidence-based methods and policies to reduce injury and death in EMS personnel from an agency level.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

SIDDIQUI, SHAMOON AHMAD. "DFT STUDY OF COFn(n = 1-6) NANO CLUSTERS: AN INVESTIGATION OF SUPERHALOGEN PROPERTIES." Journal of Theoretical and Computational Chemistry 11, no. 04 (July 16, 2012): 723–34. http://dx.doi.org/10.1142/s0219633612500484.

Повний текст джерела
Анотація:
Superhalogen properties of CoFn (n = 1 - 6) clusters have been investigated using density functional theory. These calculations reveal the unusual properties of a Cobalt (Co) atom interacting with fluorine (F) atoms. Up to six F atoms are bound to a single Co atom, which results in increase of electron affinities as successive fluorine atoms are attached, reaching a peak value of 7.43 eV for CoF5 . The large HOMO–LUMO energy gap, both in neutral and anionic form, further provide evidence of their stability. These unusual properties brought about by involvement of inner shell 3d-electrons, which not only allow CoFn (n = 1 - 6) clusters to belong to the class of superhalogens but also show that its valence can exceed the nominal value of 2 or 3.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Sesé, Lucile, Hilario Nunes, Vincent Cottin, Shreosi Sanyal, Morgane Didier, Zohra Carton, Dominique Israel-Biet, et al. "Role of atmospheric pollution on the natural history of idiopathic pulmonary fibrosis." Thorax 73, no. 2 (August 10, 2017): 145–50. http://dx.doi.org/10.1136/thoraxjnl-2017-209967.

Повний текст джерела
Анотація:
IntroductionIdiopathic pulmonary fibrosis (IPF) has an unpredictable course corresponding to various profiles: stability, physiological disease progression and rapid decline. A minority of patients experience acute exacerbations (AEs). A recent study suggested that ozone and nitrogen dioxide might contribute to the occurrence of AE. We hypothesised that outdoor air pollution might influence the natural history of IPF.MethodsPatients were selected from the French cohort COhorte FIbrose (COFI), a national multicentre longitudinal prospective cohort of IPF (n=192). Air pollutant levels were assigned to each patient from the air quality monitoring station closest to the patient’s geocoded residence. Cox proportional hazards model was used to evaluate the impact of air pollution on AE, disease progression and death.ResultsOnset of AEs was significantly associated with an increased mean level of ozone in the six preceding weeks, with an HR of 1.47 (95% CI 1.13 to 1.92) per 10 µg/m3 (p=0.005). Cumulative levels of exposure to particulate matter PM10 and PM2.5 were above WHO recommendations in 34% and 100% of patients, respectively. Mortality was significantly associated with increased levels of exposure to PM10 (HR=2.01, 95% CI 1.07 to 3.77) per 10 µg/m3 (p=0.03), and PM2.5 (HR=7.93, 95% CI 2.93 to 21.33) per 10 µg/m3 (p<0.001).ConclusionThis study suggests that air pollution has a negative impact on IPF outcomes, corroborating the role of ozone on AEs and establishing, for the first time, the potential role of long-term exposure to PM10 and PM2.5 on overall mortality.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

caslan, Fethiye, Ekrem Cicek, Sumeyra Gungoren, Meryem Kutuk, and Ali Tufan. "Peer bullying, anxiety, and depression levels among Turkish children with Childhood Onset Fluency Disorder (COFD): A single-center, case-control study." Psychiatry and Behavioral Sciences 12, no. 3 (2022): 99. http://dx.doi.org/10.5455/pbs.20220412092734.

Повний текст джерела
Анотація:
Objective: Childhood Onset Fluency Disorder (COFD) is associated with elevated levels of emotional/ behavioral problems and peer bullying. Studies on Turkish children with COFD are limited. We aimed to evaluate rates of peer bullying and its relationships with stuttering severity and symptoms of depression and anxiety among Turkish children with COFD. Method: Forty 8-12 years old children with COFD without comorbid neurological/ medical disorders and 36 age- and gender-matched controls were evaluated with self-report scales for depression, trait/ state anxiety and peer bullying. Stuttering severity was evaluated with Stuttering Severity Instrument-4. Multivariate and bivariate analyses were used in comparisons. P was set at 0.05. Results: COFD group had significantly elevated depression and state anxiety scores while trait anxiety was elevated but at trend levels. 52.5 % of children with COFD was bullied while this rate was 27.8 % for controls (Odds Ratio= 2.9). Bullying was not related with gender, self-reported symptoms and stuttering severity. Conclusion: Standardized trainings/practices should be introduced among Turkish speech and language therapists to screen and address peer bullying, depression, and anxiety among children with COFD in collaboration with child and adolescent psychiatrists.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Zhou, Chuncheng, Nan Hu, Jianlin Wu, and Jibao Gu. "A new scale to measure cross-organizational cultural intelligence." Chinese Management Studies 12, no. 3 (August 6, 2018): 658–79. http://dx.doi.org/10.1108/cms-10-2017-0309.

Повний текст джерела
Анотація:
Purpose Cross-organizational cultural intelligence (COCI) is conceptualized as an ability of individuals to interact effectively with persons from different organizational cultures. To deal with culture differences in cross-organizational context, organizations need to select employees with high COCI. This study aims to develop an instrument to measure employees’ COCI in a cross-organizational context. Design/methodology/approach The present study was conducted in three steps to develop a scale to measure COCI. First, 39 statements were identified based on a series of interviews. Then, via a survey of 275 part-time MBA students, 18 statements were categorized into four dimensions, namely, cognition, motivation, collaborative communication and behavioral adaptability. Finally, convergent, discriminant, predictive and incremental validity of the scale were tested. Findings This study extends the cultural intelligence to the cross-organizational context. The COCI concept provides theoretical support for cultural intelligence research in the cross-organizational context. Therefore, the present study broadens the research field of cultural intelligence. A four-dimensional scale was developed to measure COCI, which includes cognition, motivation, collaborative communication and behavioral adaptability. High COCI can enhance employee’s performance in a cross-organizational context. Research limitations/implications This study still has several limitations. First, the self-report questionnaire indicated that the relationship between COCI and other constructs may be stronger because of single-source, self-reported data collection. Second, the new scale was developed in China. Although some respondents came from foreign companies, most surveyed employees belonged to Chinese enterprises. Based on the current results, COCI scale exhibits promise as a measurable criterion, but it requires more refinement and validation. Additional work in this area can explore factors that can influence or improve individual COCI. A theoretical network of COCI that includes predictors, consequences, mediators and moderators by theoretical research can be established. Practical implications The COCI scale can be used in organizational management. Also, the COCI scale can help organizations understand the meanings of the employees’ COCI and select employees with high COCI during the recruitment. It makes managers easier to choose qualified candidates for inter-organizational projects. Beyond that, organizations can develop employees’ COCI according to the proposed four dimensions. Originality/value The development of the valid COCI scale will facilitate future research on boundary spanning. The COCI scale can measure individual cultural intelligence in a cross-organizational context. The present study has verified that COCI is different from emotional intelligence and provided a new perspective to explore the importance of individual ability in boundary-spanning activities. The instrumental support can help researchers effectively understand COCI and explore its potentials in boundary-spanning activities.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Chirita, M., G. Robins, R. L. Stamps, R. Sooryakumar, M. E. Filipkowski, C. J. Gutierrez, and G. A. Prinz. "Brillouin light scattering study of magnetic coupling in CoFe/Mn/CoFe." Physical Review B 58, no. 2 (July 1, 1998): 869–76. http://dx.doi.org/10.1103/physrevb.58.869.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Chen, S. Y., Y. D. Yao, and J. M. Wu. "Magnetoresistance study and interlayer coupling of CoFe/Os/CoFe thin films." Journal of Magnetism and Magnetic Materials 304, no. 1 (September 2006): e37-e40. http://dx.doi.org/10.1016/j.jmmm.2006.02.068.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Дисертації з теми "COFI study"

1

Moreno, Ana Carolina Ramos. "Caracterização molecular do gene fliC de Escherichia coli enterotoxigênica pela análise de seu polimorfismo de restrição." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/9/9136/tde-04022015-091115/.

Повний текст джерела
Анотація:
Neste estudo, mostramos a possibilidade de identificação dos AgH de ETEC pela caracterização molecular do gene fliC pela análise de seu polimorfismo de restrição. Um único alelo de fliC de ETEC foi encontrado para cada antígeno flagelar, utilizando-se a endonuclease RsaI, com exceção do H21. Além de cepas móveis, isolados imóveis também puderam ser caracterizados por essa técnica molecular. A alta tipabilidade da PCR-RFLP foi comprovada por meio de sua aplicação não só a amostras de ETEC com AgH previamente desconhecidos, mas também a outras linhagens de E. coli. Observamos que após identificação do antígeno flagelar das amostras de ETEC pela PCR-RFLP, a determinação do antígeno somático pôde ser direcionada, diminuindo assim, o número de anti-soros utilizados para a pesquisa do AgO. A técnica de PCR-RFLP, em nosso estudo, mostrou uma sensibilidade de 83% e 100% de especificidade. Esta técnica foi mais rápida na identificação do AgH de E. coli (2 dias) em comparação à sorologia clássica (7 ou mais dias, dependendo da motilidade da cepa). Acreditamos que o método de soroaglutinação para determinação do AgH será substituído rapidamente pela PCR-RFLP. Contudo, a soro aglutinação não poderá ser totalmente dispensada em curto prazo. No futuro, com o perfil molecular obtido dos alelos de cepas procedentes de estudos epidemiológicos, novos padrões serão definidos para as cepas diarreiogênicas de E. coli, permitindo o abandono da sorologia para AgH.
In this study, we showed that the H antigens of ETEC can be characterised by restriction analysis of the polymorphism of the fliC gene. Only one allele of the fliC gene of ETEC was found for each flagellar antigen when restriction endonuclease RsaI was used, with the exception of H21 . Additionally, non-motile strains could also be characterised using this molecular technique. The high typeability of this technique was demonstrated by the fact that it can not only be applied to ETEC samples with previously unknown H antigens but also to all other lineages belonging to the E. coli species. Moreover, the determination of the somatic antigen was guided by the identification of the flagellar antigen of ETEC strains by PCR-RFLP, thus reducing the number of anti-AgO sera used. In this study, the PCR-RFLP technique showed a sensitivity of 83% and a specificity of 100%. This technique proved to be quicker for the identification of the E. coli AgH, taking 2 days to complete, in comparison to the 7 or more days necessary when using classic serotyping. We believe that the determination of the AgH by seroagglutination will soon be substituted by the PCR-RFLP technique. However, serotyping will still have to be used in the short run, for further studies involving PCR-RFLP must be carried out. In the future, with the determination of the molecular profiles of alleles of strains obtained in epidemiological studies, new patterns will have been described for the diarrhoeagenic strains of E. coli, thus permitting the abandonment of AgH serotyping for good.
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Kaczanowska, Magdalena. "Study of the link between translation termination and ribosome biogenesis /." Stockholm : Institutionen för genetik, mikrobiologi och toxikologi, Univ, 2004. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-288.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Brown, Angela. "An ecotoxicogenomic study in Escherichia coli K12-MG1655." Thesis, University of Newcastle Upon Tyne, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.417436.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Liu, Guowen. "A study of the Escherichia coli cell cycle." Thesis, University of Edinburgh, 2000. http://hdl.handle.net/1842/12440.

Повний текст джерела
Анотація:
The ftsK gene of Escherichia coli encodes a 147kDa peptide, which consists of three distinct domains; namely a conserved N-terminal domain, a proline and glutamine rich region, and a C-terminal domain with consensus nucleotide-binding pocket (Begg et al., 1995). The N-terminus is essential for cell division (Begg et al., 1995; Draper et al 1998; Wang and Lutkenhaus 1998) and targets the whole protein to the septum (Yu et al., 1998 and Wang and Lutkenhaus, 1998). It was found in this thesis that depletion of the C-terminal domain resulted in the appearance of cells with abnormally located chromosomes and also in cell division-dependent SOS induction. Further study in this thesis showed that it was required only for chromosomal dimer resolution. The phenomenon of cell division-dependent SOS induction in FtsK-depleted GLC600 cells suggested that chromosome partition mutants should have continuous SOS induction. A study of the mutants obtained in this way showed that the RuvABC proteins, which are required for the resolution of recombination intermediates, are involved in chromosome partition. Over-expression of RuvAB could cause inhibition of cell division even in recA- cells, slow down the elongation of chromosome replication and cause the repression of transcription of cell division genes in the 2min region of the E. coli chromosome. To confirm that cell division and chromosome replication are coupled, nalidixic acid treatment and thymine starvation were used to block chromosome replication and it was found that cell division was coupled with chromosome replication at the level of transcription. It was also found that over-expression of DsbB, a protein required for protein disulfide bond formation in E. coli (Bardwell et al., 1993), resulted in the loss of the rod shape of E. coli cells. Over-expression of another gene named friL caused inhibition of cell division at a very early stage. It is proposed that FriL might be a regulator of cell division.
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Jepson, Alys Katherine. "E. coli motility and growth : a biophysical study." Thesis, University of Edinburgh, 2014. http://hdl.handle.net/1842/10484.

Повний текст джерела
Анотація:
This thesis comprises two parts, both concerned with the study of Escherichia coli bacterial suspensions. The first part investigates E. coli motility whilst the second part explores E. coli growth in the presence of the antimicrobial peptide pexiganan. In Part 1 I measure the three-dimensional diffusion of non-motile cells in an active suspension of E. coli, using Differential Dynamic Microscopy (DDM). It is found that tracer diffusivity is enhanced linearly as a function of the bath activity, defined as the product of the number density of active bacteria and their average speed. The absolute enhancement is measured to be 1:8 ± 0:1 times smaller that that published previously in the vicinity of a surface, in agreement with theoretical predictions of enhanced diffusion by far-field advection. The diffusivities of non-motile mutants with and without paralysed flagella are enhanced to the same extent, despite a difference in hydrodynamic radii. In addition, the protocol for growing, preparing and measuring motile E. coli is optimised using DDM. In Part 2 I investigate how E. coli density in liquid media supplemented with pexiganan influences the measurement of its Minimum Inhibitory Concentration (MIC). Growth curves, peptide bioassays and single cell microscopy are used. It is found that population density drops rapidly when pexiganan is introduced, but regrowth occurs within 24 hours at sub-MIC concentrations. The shape of the density curve is explained by peptide depletion linked to cell death and immediate recovery of cells exposed to the peptide. As expected from these findings, the system displays a substantial inoculum effect, quantified with a fitted power law. Substantial variation is seen between replicate MIC assays; an inherent property of the system which derives from the drop to small numbers of viable cells before regrowth. Finally, I show that DDM measurements of E. coli motility in antimicrobial peptides can provide an alternative, high-throughput density curve.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Maderbocus, Riyaz. "A study of outer membrane biogenesis in E. coli." Thesis, University of Birmingham, 2013. http://etheses.bham.ac.uk//id/eprint/4098/.

Повний текст джерела
Анотація:
The outer membrane (OM) of Escherichia coli is an essential organelle. The OM allows E. coli to interact with its environment and has a critical function as a barrier to prevent the entry of toxic molecules into the cell. The OM is composed of phospholipids, lipoproteins, outer membrane β-barrel proteins (OMPs) and lipopolysaccharide (LPS). The correct ratio of these components is needed to ensure proper OM barrier function is maintained. Assembly of OMPs is performed by the Bam (β-barrel assembly machinery) complex, lipoproteins by the Lol (Localisation of lipoproteins) pathway and LPS by the Lpt (LPS transport) pathway. The factors responsible for the assembly of phospholipids at the OM are unknown. This study presents two key areas in understanding OM biogenesis. Firstly, a comprehensive mutagenesis screen was performed on the Bam complex member BamE. This analysis along with the structure of BamE has indicated crucial regions for BamE function. Secondly, we have performed a structure and function analysis on the previously uncharacterised protein, YraP. The structure of YraP has been solved and represents a novel fold. Additionally, we have obtained some functional evidence that suggest that YraP is involved in phospholipid biogenesis in the OM.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Zheng, Yunan. "Study of Allosteric Regulation of Escherichia coli Aspartate Transcarbamoylase." Thesis, Boston College, 2013. http://hdl.handle.net/2345/3683.

Повний текст джерела
Анотація:
Thesis advisor: Evan R. Kantrowitz
For nearly 60 years the ATP activation and the CTP inhibition of Escherichia coli aspartate transcarbamoylase (ATCase) has been the textbook example of allosteric regulation. We present kinetic data and 5 X-ray structures determined in the absence and presence of a Mg2+ concentration within the physiological range. In the presence of 2 mM divalent cations (Mg2+, Ca2+, Zn2+) CTP does not significantly inhibit the enzyme while the allosteric activation by ATP is enhanced. The data suggest that the actual allosteric inhibitor in vivo of ATCase is the combination of CTP, UTP and a M2+ cation and the actual allosteric activator is ATP and M2+ or ATP, GTP and M2+. The structural data reveals that two NTPs can bind to each allosteric site with a Mg2+ ion acting as a bridge between the triphosphates. Thus the regulation of ATCase is far more complex than previously believed and calls many previous studies into question. The X-ray structures reveal the catalytic chains undergo essentially no alternations, however, several regions of the regulatory chains undergo significant structural changes. Most significant is that the N-terminal regions of the regulatory chains exist in different conformations in the allosterically activated and inhibited forms of the enzyme. Here, a new model of allosteric regulation is proposed
Thesis (MS) — Boston College, 2013
Submitted to: Boston College. Graduate School of Arts and Sciences
Discipline: Chemistry
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Hidalgo, González Ricardo. "Infrared spectroelectrochemical study of E. coli NiFe hydrogenase 1." Thesis, University of Oxford, 2016. https://ora.ox.ac.uk/objects/uuid:2cd6fb00-ba61-4697-9fef-64d395db29e0.

Повний текст джерела
Анотація:
This thesis investigates the catalytic mechanism of NiFe hydrogenases. The specific enzyme studied in this work, E. coli Hyd-1, is an efficient catalyst for H2 oxidation even in the presence of O2. A method for studying the chemistry of the active site of this enzyme, under catalytic conditions, is developed. The combination of IR spectroscopy with protein film electrochemistry in situ is demonstrated. This was achieved by adsorbing the hydrogenase on a high surface area carbon nanoparticle electrode; and by the design of a spectroelectrochemical flow cell that provides efficient mass transport conditions. A complete redox characterisation of the active site for a hydrogenase immobilised on a carbon electrode is described for the first time. The study of the effect of pH on the distribution of redox states demonstrates the existence of a pH equilibrium between the Ni-C and the Ni-L states. It is shown that the active site responds to the pH of the external solution, and that the increase in pH acts as a driving force that removes the proton further away from the active site. Studies under electrocatalytic conditions provides direct evidence of intermediates of the catalytic cycle. The role of Ni-SI, Ni-R, and Ni-C is confirmed. Furthermore, Ni-L is detected under turnover conditions and therefore shown to be an important intermediate in the cycle. The detection of different protonation states of Ni-L and Ni-R is proposed to provide information on the transport of the protons as they start to move away from the active site. In the investigation of O2 inhibition, Ni-B (detected spectroscopically) is directly related to the loss in activity upon the attack of O2 for the first time. Also, the formation of solely Ni-B from the reaction with O2 (no other O2-damaged species are detected) provides further evidence on the ability of O2-tolerant hydrogenases of having an effective mechanism for dealing with O2 tolerance. A thorough study on the interaction of CO with Hyd-1 proves unequivocally that this O2-tolerant hydrogenase does bind CO, and that CO does inhibit its catalytic activity (both H2 and H+ reduction). This helps clarify how CO interacts with O2-tolerant hydrogenases. Overall, the work in this thesis contributed to the understanding of key mechanistic aspects in O2-tolerant hydrogenases. The technique for combining protein film electrochemistry with IR spectroscopy in situ shall provide valuable opportunities for providing new insight into the mechanisms of hydrogenases and other metalloenzymes that bind small molecules.
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Pg, Hj Besar Dk Hjh Siti Norainna. "Engaging higher education students with social media : MIB module case study." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/engaging-higher-education-students-with-social-mediamib-module-case-study(a3b1b263-7e9d-44ec-a9cc-93f7840c4f31).html.

Повний текст джерела
Анотація:
This thesis reports on a study which investigated the application of social media in teaching Malay Islamic Monarchy (MIB) in a University of Brunei. The aim was to complement the on-campus delivery of this module, encourage student engagement and produce more active than passive learners. However, tensions existed between social media and the content of the course because of the potential of social media to drown and influence Bruneian Malay cultures and Islamic beliefs in a way that is not consistent with MIB. A questionnaire to 362 undergraduate students at the University of Brunei Darussalam taking the PB1501 MIB module in the semester 1 2012/2013 provided an initial sense of social media use and expectations. Six MIB teachers were also selected to represent different perspective of using social media in MIB module. Furthermore, the observation of ten MIB Facebook groups spaces and content analysis of ten MIB Facebook groups' transcripts produced information on teaching and learning activities as well as findings as to how teachers facilitate student engagement. The findings of the study indicate that whilst social media is a tool that should be able to solve the pedagogical problems in the MIB course, at the same time cultural obstacles are perceived by some teachers in this particular setting, impacting on its acceptance. Findings suggest that the implementation of social media such as Facebook in order to solve a pedagogical problem have raised tensions in this specific cultural environment. The research also shows the MIB teachers have mixed feelings about the fact that social media could complement MIB education. A way of conceiving the tensions between these issues is provided by the Technological Pedagogical Content Knowledge (TPACK) framework developed by Koehler and Mishra (2009), which is used to understand teacher decisions with respect to MIB, MIB pedagogy and social media (TPACK). This shows the connections and interactions between the content of MIB, the MIB pedagogy and social media.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Huen, Shing-yan Michael. "A mechanistic study of lambdaphage-mediated recombination in E. coli." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B35321854.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Книги з теми "COFI study"

1

United States. Interstate Commerce Commission. Office of Transportation Analysis, ed. Railroad TOFC/COFC monitoring study. Washington, D.C: Office of Transportation Analysis, Interstate Commerce Commission, 1985.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Luigi, Castagna, ed. Nove studi sui cori tragici di Seneca. Milano: Vita e pensiero, 1996.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Khine, Aye Aye. Binding and internalization study of Escherichia coli produced verotoxin 1. Ottawa: National Library of Canada = Bibliothèque nationale du Canada, 1993.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Kemp, E. Helen. A study of the "ompT" gene of "Escherichia coli" K-12. [s.l.]: typescript, 1988.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Clark, Melanie L. A synoptic study of fecal-indicator bacteria in the Wind River, Bighorn River, and Goose Creek basins, Wyoming, June-July 2000. Cheyenne, Wyo: U.S. Dept. of the Interior, U.S. Geological Survey, 2003.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Clark, Melanie L. A synoptic study of fecal-indicator bacteria in the Wind River, Bighorn River, and Goose Creek basins, Wyoming, June-July 2000. Cheyenne, Wyo: U.S. Dept. of the Interior, U.S. Geological Survey, 2003.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Page, Lisa Jacqueline. Formate-dependent nitrite reduction in Escherichia coli: A physiological, biochemical and genetic study. Birmingham: University of Birmingham, 1991.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Potter, Laura Christine. A genetic and physiological study of the periplasmic nitrate reductase of escherichia coli. Birmingham: University of Birmingham, 1999.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Riordan, Denise Catherine Rose. A study on the survival of Escherichia coli O157:H7 in fermented meat. [s.l: The Author], 1998.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Williams, Roy Martin. A study of transcription activation by the cyclic AMP receptor protein of Escherichia coli. Birmingham: University of Birmingham, 1993.

Знайти повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Частини книг з теми "COFI study"

1

Pitout, Johann D. D. "Escherichia Coli." In Molecular Techniques for the Study of Hospital-Acquired Infection, 179–92. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2011. http://dx.doi.org/10.1002/9781118063842.ch11.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Gross, Carol, Deborah Cowing, James Erickson, Alan Grossman, David Straus, William Walter, and Yan-Ning Zhou. "Regulation of the Heat-Shock Response in Escherichia coli." In New Frontiers in the Study of Gene Functions, 21–32. Boston, MA: Springer US, 1987. http://dx.doi.org/10.1007/978-1-4613-1845-3_2.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Costanza, Jole, Luca Zammataro, and Giuseppe Nicosia. "Programming Living Machines: The Case Study of Escherichia Coli." In Biomimetic and Biohybrid Systems, 377–79. Cham: Springer International Publishing, 2014. http://dx.doi.org/10.1007/978-3-319-09435-9_35.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Sillen, Alain, Jens Hennecke, Rudi Glockshuber, and Yves Engelborghs. "Fluorescence Study of the DsbA Protein from Escherichia Coli." In Topics in Fluorescence Spectroscopy, 103–21. Boston, MA: Springer US, 2002. http://dx.doi.org/10.1007/0-306-47102-7_6.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Yamauchi, Taro, Yumiko Otsuka, and Lina Agestika. "Influence of Water, Sanitation, and Hygiene (WASH) on Children’s Health in an Urban Slum in Indonesia." In Global Environmental Studies, 101–27. Singapore: Springer Nature Singapore, 2022. http://dx.doi.org/10.1007/978-981-16-7711-3_7.

Повний текст джерела
Анотація:
AbstractUnsafe drinking water, poor sanitation, and inadequate hygiene are key contributors to deteriorating child health in low- and middle-income countries. This chapter focuses on (1) evaluating child health and nutritional status; (2) clarifying the factors contributing to undernutrition and diarrhea prevalence by focusing on water, sanitation, and hygiene (WASH); and (3) evaluating fecal contamination and children’s hand hygiene. The study was conducted at a preschool and two elementary schools in densely populated Bandung, Indonesia, targeting children and their caretakers, using anthropometric measurements, handwashing observation, hand bacteria testing, and questionnaires. The results showed that not using a towel after handwashing was significantly associated with increased risk of stunting. Children from households using tap water instead of tank water as drinking water suffered from increased risk of stunting and thinness. Moreover, children from households using open containers for water storage were associated with increased risk of diarrhea. Most children (98.7%) had hand fecal contamination, with girls having significantly less Escherichia coli (E. coli) than boys. E. coli counts were negatively correlated with handwashing technique, handwashing with soap, and a developed WASH index. The findings suggest that successful home drinking water management and proper personal hygiene practices are important for attaining better child health.
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Dhang, Partho, Philip Koehler, Roberto Pereira, and Daniel D. Dye II. "Flies." In Key questions in urban pest management: a study and revision guide, 39–46. Wallingford: CABI, 2022. http://dx.doi.org/10.1079/9781800620179.0005.

Повний текст джерела
Анотація:
Abstract This book chapter discusses flies. Filth-breeding flies are usually broken down by the pest management industry into large flies and small flies. The most common fly is the house fly, and its larvae develop in farm animal manure and decaying plant material. It is important to understand the conditions where filth-breeding fly larvae develop in order to control them in urban settings. Some of the large flies of importance are the house fly, blow fly and flesh fly. Small flies are sometimes called gnats and develop in places like drains, residues of organic matter and food waste. Other fly larvae, like blow flies and flesh flies, develop in decaying meat, dead animals, and high protein decaying waste. Apart from houseflies, the most important flies to the urban pest management industry are the filth-breeding flies. With livestock and poultry production being concentrated into small areas near urban centers, house flies can develop in manure piles and migrate into residences and commercial establishments. The filth-breeding flies are considered very important disease transmitting flies throughout most parts of the world. The food source for filth-breeding fly larvae is usually decaying plant and animal matter. They pick up disease organisms on their bodies or orally, and then move them to human food by contact with their contaminated bodies or by regurgitation of pathogens. The ability of adult flies to move rapidly from decaying plant and animal materials make them important mechanical disease vectors. The important pathogens mechanically transmitted by flies are food poisoning bacteria (Shigella, Salmonella, E. coli) and cholera.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Ran, Zhilin, Zhe Wang, Meng Yao, and Shaofeng Li. "Study on the Inactivation of E. coli in Water by UV-LED." In Sustainable Development of Water and Environment, 19–28. Cham: Springer International Publishing, 2019. http://dx.doi.org/10.1007/978-3-030-16729-5_3.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Hao, Zhiqi, Shaolin Chen, and David B. Wilson. "Study of cadmium uptake and accumulation in Lactobacillus plantarum and Escherichia coli." In Global Environmental Biotechnology, 83–92. Dordrecht: Springer Netherlands, 1997. http://dx.doi.org/10.1007/978-94-017-1711-3_8.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Mo, Yirong, Zexing Cao, and Yuchun Lin. "Transport Mechanism in the Escherichia coli Ammonia Channel AmtB: A Computational Study." In Challenges and Advances in Computational Chemistry and Physics, 397–429. Dordrecht: Springer Netherlands, 2010. http://dx.doi.org/10.1007/978-90-481-3034-4_15.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Giuliodori, Anna Maria. "Cold Shock Response inEscherichia Coli: a Model System to Study Posttranscriptional Regulation." In Stress and Environmental Regulation of Gene Expression and Adaptation in Bacteria, 859–72. Hoboken, NJ, USA: John Wiley & Sons, Inc., 2016. http://dx.doi.org/10.1002/9781119004813.ch84.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.

Тези доповідей конференцій з теми "COFI study"

1

Ali, Noor Subhi, Rafid A. Abdulkareem, and Rasha Subhi Ali. "Study of diarrheageneic E. coli in Iraqi children." In 3RD INTERNATIONAL SCIENTIFIC CONFERENCE OF ALKAFEEL UNIVERSITY (ISCKU 2021). AIP Publishing, 2022. http://dx.doi.org/10.1063/5.0067848.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Daineko, A. V., A. B. Bulatovski, and A. I. Zinchenko. "STUDY ON POTENTIAL ENGINEERING OF ESCHERICHIA COLI XANTHOSE PHOSPHORYLASE STRAIN-PRODUCER." In SAKHAROV READINGS 2021: ENVIRONMENTAL PROBLEMS OF THE XXI CENTURY. International Sakharov Environmental Institute of Belarusian State University, 2021. http://dx.doi.org/10.46646/sakh-2021-2-38-41.

Повний текст джерела
Анотація:
Genetic engineering is an actively developing branch of modern biotechnology. Using the methods of genetic engineering, it is possible to construct new forms of microorganisms that can synthesize a variety of substances, including enzymes. Xanthosine phosphorylase is the second purine nucleoside phosphorylase (PNP-II) in E. coli. This enzyme performs both reactions of phosphorolysis and the synthesis of purine deoxy / ribonucleosides. Due to this ability, xanthosine phosphorylase can catalyze the reaction of the formation of nicotinamide riboside. This substance is a precursor of the most important coenzyme NAD+ in the body, which plays a key role in the aging process. As a result of the study, a new strain of E. coli pET42a-xapA was constructed. This strain produces the protein xanthosine phosphorylase.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Wang, Hengyu, Jeong-Hwan Kim, Min Zou, Steve Tung, and Jin-Woo Kim. "The Effect of Surface Nano/Micro-Texturing on Escherichia Coli Cell Adhesion." In 2008 Second International Conference on Integration and Commercialization of Micro and Nanosystems. ASMEDC, 2008. http://dx.doi.org/10.1115/micronano2008-70146.

Повний текст джерела
Анотація:
Control of cell-to-surface adhesion has significant impacts on various biological and biomedical applications. In this study, the adhesion of Escherichia coli (E. coli) cells on nano/micro-textured surfaces produced by a unique surface texturing technique, aluminum-induced crystallization (AIC) of amorphous silicon (a-Si), was studied in order to control E. coli cell adhesion on glass substrates in an E. coli-based whole-cell chemical sensor. It was found that textured surfaces significantly enhanced cell-to-surface adhesion. Among the textured surfaces, nano/micro-textured surfaces showed advantage over micro-textured surfaces on the cell-to-surface adhesion. Study of the cell-to-surface adhesion mechanism suggests that the cell adhesion efficiency was controlled by the particle density of the textured surfaces.
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Al-Asmar, Jawaher, Sara Rashwan, and Layla Kamareddine. "The use of Drosophila Melanogaster as a Model Organism to study the effect of Bacterial Infection on Host Survival and Metabolism." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2020. http://dx.doi.org/10.29117/quarfe.2020.0186.

Повний текст джерела
Анотація:
Enterobacteriaceae, a large family of facultative anaerobic bacteria, encloses a broad spectrum of bacterial species including Escherichia coli, Salmonella enterica, and Shigella sonnei, that produce enterotoxins and cause gastrointestinal tract diseases. While much is known about the regulation and function of enterotoxins within the intestine of the host; the lack of cheap, practical, and genetically tractable model organisms has restricted the investigation of others facets of this host-pathogen interaction. Our group, among others, has employed Drosophila melanogaster, as a model organism to shed more light on some aspects of host-pathogen interplays. In this project, we addressed the effect of Escherichia coli, Salmonella enterica, and Shigella sonnei infection on altering the metabolic homeostasis of the host. Drosophila melanogaster flies were orally infected with Escherichia coli, Salmonella enterica, or Shigella sonnei, a method that mimics the natural route used by enteric pathogens to gain access to the gastrointestinal tract in humans. The results of our study revealed that both Escherichia coli and Shigella sonnei pathogens were capable of colonizing the host gut, resulting in a reduction in the life span of the infected host. Escherichia coli and Shigella sonnei infected flies also exhibited altered metabolic profiles including lipid droplets deprivation from their fat body (normal lipid storage organ in flies), irregular accumulation of lipid droplets in their gut, and significant elevation of systemic glucose and triglyceride levels. These metabolic alterations could be mechanistically attributed to the differential down-regulation in the expression of metabolic peptide hormones (Allatostatin A, Diuretic hormone 31, and Tachykinin) detected in the gut of Escherichia coli and Shigella sonnei infected flies. Salmonella enterica; however, was unable to colonize the gut of the host; and therefore, Salmonella enterica infected flies exhibited a relatively normal metabolic status as that of non infected flies. Gaining a proper mechanistic understanding of infection-induced metabolic alterations helps in modulating the pathogenesis of gastrointestinal tract diseases in a host and opens up for promising therapeutic approaches for infection induced metabolic disorders
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Thoriqoh, Hanifatun Nisa Ath, Budi Haryanto, and Ela Laelasari. "The Association between Food Hygiene and the Escherichia Coli Contamination on School Snack at Elementary School in Cakung Subdistrict, East Jakarta." In The 7th International Conference on Public Health 2020. Masters Program in Public Health, Universitas Sebelas Maret, 2020. http://dx.doi.org/10.26911/the7thicph.02.13.

Повний текст джерела
Анотація:
Background: Unsafe food hygiene poses threats for becoming disease transmission. The most common of foodborne pathogenic bacteria is Escherichia coli. The purpose of this study was to examine the association between food hygiene and the contamination of escherichia coli bacteria on school snack. Subejcts and Method: A cross-sectional study was conducted in Cakung, East Jakarta from December 2016 to January 2017. A sample of 60 food handlers from a total of 147 foods handlers’ population was selected by cluster sampling. The dependent variable was E. coli bateria. The independent variables were proper hand washing, food serving aids, proper equipment washing, types of selling facilities, sanitation facilities, the placement of cooked food, and food preparation. The data were collected by laboratory test result and questionnaire. The data were analyzed by multiple logistic regressions. Results: As many as 45% of the positive snacks were contaminated with E. coli bacteria. E. coli bacterial contamination on food was related to the practice of using food serving aids (OR= 5.00; 95% CI= 1.19 to 20.92; p= 0.044), a place to store cooked food (OR= 6.11; 95% CI = 1.73 to 21.59; p = 0.007) and method of presentation (OR = 7.14; 95% CI = 1.43 to 35.57; p = 0.002). Conclusion: The incidence of Escherichia coli contamination on food is related to the practice of using food serving aids, the placement of cooked food and food serving. Keywords: Escherichia coli, school snack Corresponden: Hanifatun Nisa Ath Thoriqoh. Public Health Postgraduate Study Program, Faculty of Public Health, University of Indonesia, Depok, West Java. Email: hanifatunnisa10@gmail.com. Mobile: 081808157745. DOI: https://doi.org/10.26911/the7thicph.02.13
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Lee, HyunWook, Corina Sandu, and Carvel Holton. "Wheel-Rail Dynamic Model and Stochastic Analysis of the Friction in the Contact Patch." In 2010 Joint Rail Conference. ASMEDC, 2010. http://dx.doi.org/10.1115/jrc2010-36229.

Повний текст джерела
Анотація:
The coefficient of friction (CoF) is one of the most important parameters for characterizing the contact between the wheel and the rail. The assumption of a constant CoF is still used in most theoretical studies, although experimental work indicates that the CoF depends on material and dynamic parameters. In the real world, accurate estimation of the CoF is not simple due to various uncertainties. In this paper we present a new 3D nonlinear dry CoF model at the wheel-rail contact. In addition, a stochastic analysis using the polynomial chaos theory is performed with the CoF model. The maximum amplitude of rail roughness and the lateral displacement of the wheel are considered as uncertain parameters in this study. One of the novelties in this study is that our CoF model captures the maximum CoF value (an initial peak) when the wheel starts to move. The stochastic analysis results show that the CoF probability density function (PDF) of a combination of two uncertain parameters has wider PDF ranges than the PDF obtained for only one uncertain parameter. The current work demonstrates that the CoF is strongly affected by the stochastic variation of dynamic parameters. In reality, the CoF is critical to rail tractive performance and efficiency. Thus, the PDF distribution of the CoF must be accounted for in the design of the wheel-rail system.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

Handoko, Budi Basuki, and Rini Dharmastiti. "Numerical Study on the Effects of Coefficient of Friction to the Dynamic Sliding Contact between Bearing and Talar Components of Metal on Polymer Total Ankle Replacement Implants." In International Conference on Mechanical Engineering. Switzerland: Trans Tech Publications Ltd, 2023. http://dx.doi.org/10.4028/p-s80w27.

Повний текст джерела
Анотація:
Coefficient of friction (cof) is an important variable when dealing with con-tact between mechanical parts. It depends on various tribological variables and the value can be determined only by experiments. Cof correlates with the wear of material and this is a severe problem in biomedical engineering. This research numerically studied the effects of cof between talar and bear-ing in the total ankle replacement (TAR) implants. The aim is to evaluate the contact situations affected by cof. The TAR models consist of cobalt chrome (CoCr) alloy and ultra high molecular weight polyethylene (UHMWPE) bio-materials. Five cof values of the dry, lubricated and frictionless TAR me-chanical contacts under ankle gait load were examined. The models use a fixed 1 mm element size for UHMWPE bearing component and four element sizes for the talar component, range from 1 mm to 0.4 mm. Results show that, 1) higher cof induces higher contact pressure, 2) contact stress is not af-fected by cof, 3) proper talar element size is 0.4 mm and 4) frictionless model can be used for the TAR contact mechanic computation. Frictionless model calculates equal contact stress and lower contact pressures with an error of 2.68 % compared to the smooth model.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Beechert, Jacqueline. "Study of Al-26 in the COSI 2016 Superpressure Balloon Flight." In 37th International Cosmic Ray Conference. Trieste, Italy: Sissa Medialab, 2021. http://dx.doi.org/10.22323/1.395.0611.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Johar, Alreem, Najlaa Al-Thani, Sara Al-Hadidi, Elyes Dlissi, Mahmoud Mahoud, and Nahla Eltai. "Antibiotic Resistance and Virulence Gene Patterns Associated with Avian Pathogenic Escherichia coli from Broiler Chickens in Qatar." In Qatar University Annual Research Forum & Exhibition. Qatar University Press, 2021. http://dx.doi.org/10.29117/quarfe.2021.0102.

Повний текст джерела
Анотація:
Introduction: Avian Pathogenic Escherichia coli (APEC) is the contributing agent behind the avian infectious disease colibacillosis, which causes substantial fatalities in poultry industries that significantly impact the economy and food safety. Several virulence genes have been shown to be concomitant with the extra-intestinal survival of APEC. This study investigates the antibiotic resistance patterns and APEC‐associated virulence genes content in Escherichia coli (E. coli) isolated from non‐healthy and healthy broiler chickens from a commercial poultry farm in Qatar. Material and Methods: 158 E. coli strains were isolated from 47 chickens from five different organs (air sac, cloacal, kidney, liver, and trachea). Genomic DNA was extracted from E. coli using the QIAamp Pathogen Mini Kit. Multiplex PCR was executed to detect tsh, iucD, ompT, hlyF, iroN, iss, vat, cvi/cva genes associated with PPEC. Antibiotic susceptibility testing was performed using the standard Kirby-Bauer disk and E-test. Amplified virulence genes detected were sequenced and analyzed. Graph Pad version 8 and PAST software version 4.03 were used for statistical and clustering analysis. The chi-square test was performed on all data to compare the antibiotic resistance and virulence gene patterns between non-healthy and healthy chicken samples Results: 65% of the isolated bacteria were APEC strains containing five or more virulence genes, and 34% were non‐pathogenic E. coli (NPEC) strains. The genes ompT, hlyF, iroN, tsh, vat, iss, cvi/cva, and iucD were significantly prevalent in all APEC strains. E. coli isolates showed 96% resistance to at least one of the 18 antibiotics, with high resistance to ampicillin, cephalothin, ciprofloxacin, tetracycline, and fosfomycin. Conclusions: Our findings indicate high antibiotic resistance prevalence in non-healthy and healthy chicken carcasses. Such resistant E. coli can spread to humans. Hence, special programs are required to monitor the use of antibiotics in chicken production in Qatar.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Xu, Songbo, Aydar Akchurin, X. W. Tangpong, Tian Liu, Weston Wood, and Wei-Hong Zhong. "Comparison of Tribological Performances of High Density Polyethylene Enhanced With Carbon Nanofibers." In ASME 2012 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/imece2012-86150.

Повний текст джерела
Анотація:
High density polyethylene (HDPE) is widely used as bearing material in industrial application because of its low friction and high wear resistance properties. Carbon nanofiber (CNF) reinforced HDPE nanocomposites are promising materials for biomedical applications as well, such as being the bearing materials in total joint replacements. The main objective of the present study is to investigate how the wear of HDPE can be altered by the addition of either pristine or silane treated CNFs at different loading levels (0.5 wt.% and 3 wt.%). Two types of silane coating thicknesses, 2.8 nm and 46 nm, were applied on the surfaces of oxidized CNFs to improve the interfacial bonding strength between the CNFs and the matrix. The CNF/HDPE nanocomposites were prepared through melt mixing and hot-pressing. The coefficients of friction (COFs) and wear rates of the neat HDPE and CNF/HDPE nanocomposites were determined using a pin-on-disc tribometer under dry sliding conditions. The microstructures of the worn surfaces of the nanocomposites were characterized using both scanning electron microscope (SEM) and optical microscope to analyze their wear mechanisms. Compared with the neat HDPE, the COF of the nanocomposites were reduced. The nanocomposite reinforced with CNFs coated with the thicker silane coating (46 nm) at 0.5 wt.% loading level was found to yield the highest wear resistance with a wear rate reduction of nearly 68% compared to the neat HDPE.
Стилі APA, Harvard, Vancouver, ISO та ін.

Звіти організацій з теми "COFI study"

1

Smiley, Daniel. A genetic and physiological study of an arsenite resistant, uncoupled mutant of Escherichia coli. Portland State University Library, January 2000. http://dx.doi.org/10.15760/etd.3124.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
2

Willis, C., F. Jorgensen, S. A. Cawthraw, H. Aird, S. Lai, M. Chattaway, I. Lock, E. Quill, and G. Raykova. A survey of Salmonella, Escherichia coli (E. coli) and antimicrobial resistance in frozen, part-cooked, breaded or battered poultry products on retail sale in the United Kingdom. Food Standards Agency, May 2022. http://dx.doi.org/10.46756/sci.fsa.xvu389.

Повний текст джерела
Анотація:
Frozen, breaded, ready-to-cook chicken products have been implicated in outbreaks of salmonellosis. Some of these outbreaks can be large. For example, one outbreak of Salmonella Enteritidis involved 193 people in nine countries between 2018 and 2020, of which 122 cases were in the UK. These ready-to-cook products have a browned, cooked external appearance, which may be perceived as ready-to-eat, leading to mishandling or undercooking by consumers. Continuing concerns about these products led FSA to initiate a short-term (four month), cross-sectional surveillance study undertaken in 2021 to determine the prevalence of Salmonella spp., Escherichia coli and antimicrobial resistance (AMR) in frozen, breaded or battered chicken products on retail sale in the UK. This study sought to obtain data on AMR levels in Salmonella and E. coli in these products, in line with a number of other FSA instigated studies of the incidence and nature of AMR in the UK food chain, for example, the systematic review (2016). Between the beginning of April and the end of July 2021, 310 samples of frozen, breaded or battered chicken products containing either raw or partly cooked chicken, were collected using representative sampling of retailers in England, Wales, Scotland and Northern Ireland based on market share data. Samples included domestically produced and imported chicken products and were tested for E. coli (including extended-spectrum beta-lactamase (ESBL)-producing, colistin-resistant and carbapenem-resistant E. coli) and Salmonella spp. One isolate of each bacterial type from each contaminated sample was randomly selected for additional AMR testing to determine the minimum inhibitory concentration (MIC) for a range of antimicrobials. More detailed analysis based on Whole Genome Sequencing (WGS) data was used to further characterise Salmonella spp. isolates and allow the identification of potential links with human isolates. Salmonella spp. were detected in 5 (1.6%) of the 310 samples and identified as Salmonella Infantis (in three samples) and S. Java (in two samples). One of the S. Infantis isolates fell into the same genetic cluster as S. Infantis isolates from three recent human cases of infection; the second fell into another cluster containing two recent cases of infection. Countries of origin recorded on the packaging of the five Salmonella contaminated samples were Hungary (n=1), Ireland (n=2) and the UK (n=2). One S. Infantis isolate was multi-drug resistant (i.e. resistant to three different classes of antimicrobials), while the other Salmonella isolates were each resistant to at least one of the classes of antimicrobials tested. E. coli was detected in 113 samples (36.4%), with counts ranging from <3 to >1100 MPN (Most Probable Number)/g. Almost half of the E. coli isolates (44.5%) were susceptible to all antimicrobials tested. Multi-drug resistance was detected in 20.0% of E. coli isolates. E. coli isolates demonstrating the ESBL (but not AmpC) phenotype were detected in 15 of the 310 samples (4.8%) and the AmpC phenotype alone was detected in two of the 310 samples (0.6%) of chicken samples. Polymerase Chain Reaction (PCR) testing showed that five of the 15 (33.3%) ESBL-producing E. coli carried blaCTX-M genes (CTX-M-1, CTX-M-55 or CTX-M-15), which confer resistance to third generation cephalosporin antimicrobials. One E. coli isolate demonstrated resistance to colistin and was found to possess the mcr-1 gene. The five Salmonella-positive samples recovered from this study, and 20 similar Salmonella-positive samples from a previous UKHSA (2020/2021) study (which had been stored frozen), were subjected to the cooking procedures described on the sample product packaging for fan assisted ovens. No Salmonella were detected in any of these 25 samples after cooking. The current survey provides evidence of the presence of Salmonella in frozen, breaded and battered chicken products in the UK food chain, although at a considerably lower incidence than reported in an earlier (2020/2021) study carried out by PHE/UKHSA as part of an outbreak investigation where Salmonella prevalence was found to be 8.8%. The current survey also provides data on the prevalence of specified AMR bacteria found in the tested chicken products on retail sale in the UK. It will contribute to monitoring trends in AMR prevalence over time within the UK, support comparisons with data from other countries, and provide a baseline against which to monitor the impact of future interventions. While AMR activity was observed in some of the E. coli and Salmonella spp. examined in this study, the risk of acquiring AMR bacteria from consumption of these processed chicken products is low if the products are cooked thoroughly and handled hygienically.
Стилі APA, Harvard, Vancouver, ISO та ін.
3

Selinder, T. I., T. A. Roberts, D. J. Miller, M. A. Beno, G. S. Knapp, K. E. Gray, S. Ogawa, J. A. Fair, and D. B. Fraser. In situ x-ray diffraction study of CoSi{sub 2} formation during annealing of a Co/Ti bilayer on Si*(100). Office of Scientific and Technical Information (OSTI), June 1995. http://dx.doi.org/10.2172/70779.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
4

Weinberg, Zwi G., Adegbola Adesogan, Itzhak Mizrahi, Shlomo Sela, Kwnag Jeong, and Diwakar Vyas. effect of selected lactic acid bacteria on the microbial composition and on the survival of pathogens in the rumen in context with their probiotic effects on ruminants. United States Department of Agriculture, January 2014. http://dx.doi.org/10.32747/2014.7598162.bard.

Повний текст джерела
Анотація:
This research project was performed in context of the apparent probiotic effect of selected lactic acid bacteria (LAB) silage inoculants on the performance of ruminants (improved feed intake, faster live-weight gain, higher milk yields and improved feed efficiency). The overall objective was to find out how LAB affect ruminant performance. The project included several “chapters” as follows: 1. The effect of LAB silage inoculants on the survival of detrimental bacteria in rumen fluid, in vitro study (Weinberg et al., The Volcani Center). An in vitro model was developed to study the interaction between selected LAB and an E. coli strain tagged with green fluorescence protein (GFP) in buffered RF. Results indicated that both LAB inoculants and E. coli survived in the RF for several days; both LAB inoculants and LAB-treated silages did not affect survival of E. coli in rumen fluid in vitro. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the performance of high-lactating cows (Weinberg et al., The Volcani Center). Treatments included control (no additive), Lacobacillusbuchneri40788 (LB), Lactobacillus plantarumMTD1 40027 (LP) and Pediococcuspentosaceus30168 (PP), each applied at 10⁶ cfu/g FM. The silages were included in the TMR of 32 high milking Holstein cows in a controlled feeding experiment. All baled silages were of good quality. The LB silage had the numerically highest acetic acid and were the most stable upon aerobic exposure. The cows fed the LB silages had the highest daily milk yields, percent milk fat and protein. The microbiome of baled wheat silages and changes during ensiling of wheat and corn (Sela et al., The Volcani Center). Bacterial community of the baled silages was dominated mainly of two genera in total, dominated by Lactobacillus and Clostridium_sensu_stricto_12 with 300 other genera at very low abundance. Fungal community was composed mainly of two genera in total, dominated by Candida and Monascuswith 20 other genera at very low abundance. In addition, changes in the microbiome during ensiling of wheat and corn with and without addition of L. plantarumMTD1 was studied in mini-silos. Overall 236 bacterial genera were identified in the fresh corn but after 3 months Lactobacillus outnumbered all other species by acquiring 95% of relative abundance. The wheat silage samples are still under analysis. The effect of applying LAB inoculants at ensiling on survival of E. coli O157:H7 in alfalfa and corn silages(Adesogan et al., University of Florida). E. coli (10⁵ cfu/g) was applied to fresh alfalfa and corn at ensiling with or without L. plantarumor L. buchneri. The pathogen was added again after about 3 moths at the beginning of an aerobic exposure period. The inoculants resulted in faster decrease in pH as compared with the control (no additives) or E. coli alone and therefore, the pathogen was eliminated faster from these silages. After aerobic exposure the pathogen was not detected in the LAB treated silages, whereas it was still present in the E. coli alone samples. 5. The effect of feeding corn silage treated with or without L. buchnerion shedding of E. coli O157:H7 by dairy cows (Adesogan et al., UFL). BARD Report - Project 4704 Page 2 of 12 Five hundred cows from the dairy herd of the University of Florida were screened for E. coli shedding, out of which 14 low and 13 high shedders were selected. These cows were fed a total mixed ration (TMR) which was inoculated with E. coli O157:H7 for 21 days. The TMR included corn silage treated with or without L. buchneri. The inoculated silages were more stable upon aerobic exposure than the control silages; the silage inoculant had no significant effect on any milk or cow blood parameters. However, the silage inoculant tended to reduce shedding of E. coli regardless of high or low shedders (p = 0.06). 6. The effect of feeding baled wheat silages treated with or without three selected LAB silage inoculants on the rumen microbiome (Mizrahi et al., BGU). Rumen fluid was sampled throughout the feeding experiment in which inoculated wheat silages were included in the rations. Microbial DNA was subsequently purified from each sample and the 16S rRNA was sequenced, thus obtaining an overview of the microbiome and its dynamic changes for each experimental treatment. We observed an increase in OTU richness in the group which received the baled silage inoculated with Lactobacillus Plantarum(LP). In contrast the group fed Lactobacillus buchneri(LB) inoculated silage resulted in a significant decrease in richness. Lower OTU richness was recently associated in lactating cows with higher performance (Ben Shabatet al., 2016). No significant clustering could be observed between the different inoculation treatments and the control in non metric multi-dimentional scaling, suggesting that the effect of the treatments is not the result of an overall modulation of the microbiome composition but possibly the result of more discrete interactions. Significant phylum level changes in composition also indicates that no broad changes in taxa identity and composition occurred under any treatment A more discrete modulation could be observed in the fold change of several taxonomic groups (genus level analysis), unique to each treatment, before and after the treatment. Of particular interest is the LB treated group, in which several taxa significantly decreased in abundance. BARD Report - Project 4704 Page 3 of 12
Стилі APA, Harvard, Vancouver, ISO та ін.
5

Mattie, David R., Jonathon M. Hurley, Edward S. Riccio, and Teresa R. Sterner. Acute Dermal Irritation Study and Salmonella-Escherichia coli/Microsome Plate Incorporation Assay of Hydroprocessed Esters and Fatty Acids (HEFA) Bio-Based Jet Fuels. Fort Belvoir, VA: Defense Technical Information Center, January 2013. http://dx.doi.org/10.21236/ada584649.

Повний текст джерела
Стилі APA, Harvard, Vancouver, ISO та ін.
6

Sellgren, Katelyn, Christopher Gregory, Michael Hunt, Ashkay Raut, Brian Hawkins, Charles Parker, Ethan Klem, Jeffrey Piascik, and Brian Stoner. Development of an Electrochemical Process for Blackwater Disinfection in a Freestanding, Additive-Free Toilet. RTI Press, April 2017. http://dx.doi.org/10.3768/rtipress.2017.rr.0031.1704.

Повний текст джерела
Анотація:
Electrochemical disinfection has gained interest as an alternative to conventional wastewater treatment because of its high effectiveness and environmental compatibility. Two and a half billion people currently live without improved sanitation facilities. Our research efforts are focused on developing and implementing a freestanding, additive-free toilet system that treats and recycles blackwater on site. In this study, we sought to apply electrochemical disinfection to blackwater. We compared commercially available boron-doped diamond (BDD) and mixed metal oxide (MMO) electrodes for disinfection efficiency in E. coli–inoculated model wastewater. The MMO electrodes were found to be more efficient and thus selected for further study with blackwater. The energy required for disinfection by the MMO electrodes increased with the conductivity of the medium, decreased with increased temperature, and was independent of the applied voltage. Fecal contamination considerably increased the energy required for blackwater disinfection compared to model wastewater, demonstrating the need for testing in effluents representing the conditions of the final application.
Стилі APA, Harvard, Vancouver, ISO та ін.
7

McCarthy, Noel, Eileen Taylor, Martin Maiden, Alison Cody, Melissa Jansen van Rensburg, Margaret Varga, Sophie Hedges, et al. Enhanced molecular-based (MLST/whole genome) surveillance and source attribution of Campylobacter infections in the UK. Food Standards Agency, July 2021. http://dx.doi.org/10.46756/sci.fsa.ksj135.

Повний текст джерела
Анотація:
This human campylobacteriosis sentinel surveillance project was based at two sites in Oxfordshire and North East England chosen (i) to be representative of the English population on the Office for National Statistics urban-rural classification and (ii) to provide continuity with genetic surveillance started in Oxfordshire in October 2003. Between October 2015 and September 2018 epidemiological questionnaires and genome sequencing of isolates from human cases was accompanied by sampling and genome sequencing of isolates from possible food animal sources. The principal aim was to estimate the contributions of the main sources of human infection and to identify any changes over time. An extension to the project focussed on antimicrobial resistance in study isolates and older archived isolates. These older isolates were from earlier years at the Oxfordshire site and the earliest available coherent set of isolates from the national archive at Public Health England (1997/8). The aim of this additional work was to analyse the emergence of the antimicrobial resistance that is now present among human isolates and to describe and compare antimicrobial resistance in recent food animal isolates. Having identified the presence of bias in population genetic attribution, and that this was not addressed in the published literature, this study developed an approach to adjust for bias in population genetic attribution, and an alternative approach to attribution using sentinel types. Using these approaches the study estimated that approximately 70% of Campylobacter jejuni and just under 50% of C. coli infection in our sample was linked to the chicken source and that this was relatively stable over time. Ruminants were identified as the second most common source for C. jejuni and the most common for C. coli where there was also some evidence for pig as a source although less common than ruminant or chicken. These genomic attributions of themselves make no inference on routes of transmission. However, those infected with isolates genetically typical of chicken origin were substantially more likely to have eaten chicken than those infected with ruminant types. Consumption of lamb’s liver was very strongly associated with infection by a strain genetically typical of a ruminant source. These findings support consumption of these foods as being important in the transmission of these infections and highlight a potentially important role for lamb’s liver consumption as a source of Campylobacter infection. Antimicrobial resistance was predicted from genomic data using a pipeline validated by Public Health England and using BIGSdb software. In C. jejuni this showed a nine-fold increase in resistance to fluoroquinolones from 1997 to 2018. Tetracycline resistance was also common, with higher initial resistance (1997) and less substantial change over time. Resistance to aminoglycosides or macrolides remained low in human cases across all time periods. Among C. jejuni food animal isolates, fluoroquinolone resistance was common among isolates from chicken and substantially less common among ruminants, ducks or pigs. Tetracycline resistance was common across chicken, duck and pig but lower among ruminant origin isolates. In C. coli resistance to all four antimicrobial classes rose from low levels in 1997. The fluoroquinolone rise appears to have levelled off earlier and among animals, levels are high in duck as well as chicken isolates, although based on small sample sizes, macrolide and aminoglycoside resistance, was substantially higher than for C. jejuni among humans and highest among pig origin isolates. Tetracycline resistance is high in isolates from pigs and the very small sample from ducks. Antibiotic use following diagnosis was relatively high (43.4%) among respondents in the human surveillance study. Moreover, it varied substantially across sites and was highest among non-elderly adults compared to older adults or children suggesting opportunities for improved antimicrobial stewardship. The study also found evidence for stable lineages over time across human and source animal species as well as some tighter genomic clusters that may represent outbreaks. The genomic dataset will allow extensive further work beyond the specific goals of the study. This has been made accessible on the web, with access supported by data visualisation tools.
Стилі APA, Harvard, Vancouver, ISO та ін.
8

Choudhary, Ruplal, Victor Rodov, Punit Kohli, John D. Haddock, and Samir Droby. Antimicrobial and antioxidant functionalized nanoparticles for enhancing food safety and quality: proof of concept. United States Department of Agriculture, September 2012. http://dx.doi.org/10.32747/2012.7597912.bard.

Повний текст джерела
Анотація:
General concept. The reported 1-year study tested the feasibility ofpreparing antimicrobial and antioxidant nanoparticlesfunctionalized with natural phenolic compounds, as a first step to reach the ultimate goal - improving safely and quality of foods by developing novel antimicrobial and antioxidant food-contacting materials. The secondary objectives of the study were (a) selecting the most promising phenoliccompounds, (b) building nanoparticles with the selected phenolicgrafted on their Surface, and (c) testing antimicrobial and antioxidant properties of these particles. The study was expected to provide a " go/no go" decision as concerning the prospects of phenolic- bound nanoparticles as antimicrobial and antioxidant agents. Results. In course of the feasibility study, curucminwas chosen as the most promising phenoliccompound due to its high antibacterial activity exceeding other tested compounds by at leas one order of magnitude. Lipsome-typephospholipid/polydiacetylene(PDA) nanoparticlesfunctionalizedwith curcuminwere successfully built. The pitfall of limited curcumin amount that could be covalently bound to theparticle surface was circumvented by inclusion of curcunun in the liposome body. It was suggested onthe basis of fluorescence spectroscopy that curcuminwas bound by hydrophobic forces in the bi1ayer periphery of the Liposomesand therefore mightexert a contact effect on microorganisms. The curcumin­ functionalizednanoparticles(CFN) were shown to have a strong bactericidal activity towards both Gram-negative (E. coli) and Gram-positive (B. ce,·e11s) bacteria, but only limited effect against yeast. Furthermore, beyond the originallyplanned objectives, preliminary trials showed that CFN could be bound to silanized glass surface rendering aנבtiנnicrobial activity to the glass. Tnaddition, the particles showed antioxidantcapacity. Tberefore, it ,vas co11cluded tlוattlוeaims of tlוefeasibility study bad been successfully reached an
Стилі APA, Harvard, Vancouver, ISO та ін.
9

Jorgensen, Frieda, John Rodgers, Daisy Duncan, Joanna Lawes, Charles Byrne, and Craig Swift. Levels and trends of antimicrobial resistance in Campylobacter spp. from chicken in the UK. Food Standards Agency, September 2022. http://dx.doi.org/10.46756/sci.fsa.dud728.

Повний текст джерела
Анотація:
Campylobacter spp. are the most common bacterial cause of foodborne illness in the UK, with chicken considered to be the most important vehicle of transmission for this organism. It is estimated there are 500,000 cases of campylobacteriosis in the UK annually, with Campylobacter jejuni (C. jejuni) and Campylobacter coli (C. coli) accounting for approximately 91% and 8 % of infections, respectively. Although severe infection in humans is uncommon, treatment is seldom needed for human infection but usually involves the administration of a macrolide (e.g., azithromycin) or a fluoroquinolone (e.g., ciprofloxacin). An increased rate of resistance in Campylobacter in chicken to such antimicrobials could limit effective treatment options for human infections and it is therefore important to monitor changes in rates of resistance over time. In this report we analysed trends in antimicrobial resistance (AMR) in C. jejuni and C. coli isolated from chicken in the UK. The chicken samples were from chicken reared for meat (ie. broiler chicken as opposed to layer chicken (ie. egg-laying chicken)) and included chicken sampled at slaughterhouses as well as from retail stores in the UK. Datasets included AMR results from retail surveys of Campylobacter spp. on chicken sampled in the UK from various projects in the time period from 2001 to 2020. In the retail surveys, samples were obtained from stores including major and minor retail stores throughout the UK (in proportion to the population size of each nation) and Campylobacter spp. testing was performed using standard methods with the majority of isolates obtained from direct culture on standard media (mCCDA). Data from national scale surveys of broiler chicken, sampling caecal contents and carcase neckskins at slaughterhouses, undertaken by APHA in 2007/2008, and between 2012 and 2018 were also included in the study. In the APHA-led surveys, Campylobacter were isolated using standard culture methods (culture onto mCCDA) and antimicrobial susceptibility testing was performed by a standard microbroth dilution method to determine the minimum inhibitory concentration (MIC) of isolates. Care was taken when comparing data from different studies as there had been changes to the threshold used to determine if an isolate was susceptible or resistant to an antimicrobial in a small number of scenarios. Harmonised thresholds (using epidemiological cut-off (ECOFF) values) were employed to assess AMR with appropriate adjustments made where required to allow meaningful comparisons of resistance prevalence over time. Data from additional isolates where resistance to antimicrobials were predicted from genome sequence data were also considered.
Стилі APA, Harvard, Vancouver, ISO та ін.
10

Choudhary, Ruplal, Victor Rodov, Punit Kohli, Elena Poverenov, John Haddock, and Moshe Shemesh. Antimicrobial functionalized nanoparticles for enhancing food safety and quality. United States Department of Agriculture, January 2013. http://dx.doi.org/10.32747/2013.7598156.bard.

Повний текст джерела
Анотація:
Original objectives The general goal of the project was to utilize the bactericidal potential of curcumin- functionalizednanostructures (CFN) for reinforcement of food safety by developing active antimicrobial food-contact surfaces. In order to reach the goal, the following secondary tasks were pursued: (a) further enhancement of the CFN activity based on understanding their mode of action; (b) preparing efficient antimicrobial surfaces, investigating and optimizing their performance; (c) testing the efficacy of the antimicrobial surfaces in real food trials. Background to the topic The project dealt with reducing microbial food spoilage and safety hazards. Cross-contamination through food-contact surfaces is one of the major safety concerns, aggravated by bacterial biofilm formation. The project implemented nanotech methods to develop novel antimicrobial food-contact materials based on natural compounds. Food-grade phenylpropanoidcurcumin was chosen as the most promising active principle for this research. Major conclusions, solutions, achievements In agreement with the original plan, the following research tasks were performed. Optimization of particles structure and composition. Three types of curcumin-functionalizednanostructures were developed and tested: liposome-type polydiacetylenenanovesicles, surface- stabilized nanoparticles and methyl-β-cyclodextrin inclusion complexes (MBCD). The three types had similar minimal inhibitory concentration but different mode of action. Nanovesicles and inclusion complexes were bactericidal while the nanoparticlesbacteriostatic. The difference might be due to different paths of curcumin penetration into bacterial cell. Enhancing the antimicrobial efficacy of CFN by photosensitization. Light exposure strengthened the bactericidal efficacy of curcumin-MBCD inclusion complexes approximately three-fold and enhanced the bacterial death on curcumin-coated plastic surfaces. Investigating the mode of action of CFN. Toxicoproteomic study revealed oxidative stress in curcumin-treated cells of E. coli. In the dark, this effect was alleviated by cellular adaptive responses. Under light, the enhanced ROS burst overrode the cellular adaptive mechanisms, disrupted the iron metabolism and synthesis of Fe-S clusters, eventually leading to cell death. Developing industrially-feasible methods of binding CFN to food-contact surfaces. CFN binding methods were developed for various substrates: covalent binding (binding nanovesicles to glass, plastic and metal), sonochemical impregnation (binding nanoparticles to plastics) and electrostatic layer-by-layer coating (binding inclusion complexes to glass and plastics). Investigating the performance of CFN-coated surfaces. Flexible and rigid plastic materials and glass coated with CFN demonstrated bactericidal activity towards Gram-negative (E. coli) and Gram-positive (Bac. cereus) bacteria. In addition, CFN-impregnated plastic material inhibited bacterial attachment and biofilm development. Testing the efficacy of CFN in food preservation trials. Efficient cold pasteurization of tender coconut water inoculated with E. coli and Listeriamonocytogeneswas performed by circulation through a column filled with CFN-coated glass beads. Combination of curcumin coating with blue light prevented bacterial cross contamination of fresh-cut melons through plastic surfaces contaminated with E. coli or Bac. licheniformis. Furthermore, coating of strawberries with CFN reduced fruit spoilage during simulated transportation extending the shelf life by 2-3 days. Implications, both scientific and agricultural BARD Report - Project4680 Page 2 of 17 Antimicrobial food-contact nanomaterials based on natural active principles will preserve food quality and ensure safety. Understanding mode of antimicrobial action of curcumin will allow enhancing its dark efficacy, e.g. by targeting the microbial cellular adaptation mechanisms.
Стилі APA, Harvard, Vancouver, ISO та ін.
Ми пропонуємо знижки на всі преміум-плани для авторів, чиї праці увійшли до тематичних добірок літератури. Зв'яжіться з нами, щоб отримати унікальний промокод!

До бібліографії