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排序方式: 共有6945条查询结果,搜索用时 15 毫秒
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Wendy A. Douglass Robert H. Hyland Christopher D. Buckley Aymen Al-Shamkhani Jacqueline M. Shaw Sarah L. Scarth David L. Simmons S.K.Alex Law 《FEBS letters》1998,440(3):125
The cysteine-rich region (CRR) of the β2 integrin subunit was replaced by that of β1 to give the chimera β2NV1. β2NV1 can combine with αL to form a variant leukocyte-function-associated antigen (LFA)-1 on COS cell surface, suggesting that the specificity of the β2 interaction with αL does not lie in the CRR. Unlike those expressing wild-type LFA-1, COS cells expressing αLβ2NV1 are constitutively active in intercellular adhesion molecule (ICAM)-1 adhesion. These results suggest that activation of LFA-1 involves the release of an intramolecular constraint, which is maintained, in part, by the authentic β2 CRR. 相似文献
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Duangta Pawa Rebecca Firestone Sindh Ratchasi Olivia Dowling Yaowalak Jittakoat Alex Duke Gary Mundy 《PloS one》2013,8(10)
Transgender women are particularly at risk of HIV infection, but little evidence exists on effective HIV prevention strategies with this population. We evaluated whether Sisters, a peer-led program for transgender women, could reduce HIV risks in Pattaya, Thailand. The study used time-location sampling to recruit 308 transgender women in Pattaya into a behavioral survey in 2011. Coarsened exact matching was used to create statistically equivalent groups of program participants and non-participants, based on factors influencing likelihood of program participation. Using multivariable logistic regression, we estimated effects of any program participation and participation by delivery channel on: condom use at last sex; consistent condom and condom/water-based lubricant use in the past 3 months with commercial, casual, and regular partners; and receipt of HIV testing in the past 6 months. Program coverage reached 75% of the population. In a matched sub-sample (n = 238), participation in outreach was associated with consistent condom/water-based lubricant use with commercial partners (AOR 3.22, 95% CI 1.64–6.31). Attendance at the Sisters drop-in center was associated with receiving an HIV test (AOR 2.58, 95% CI 1.47–4.52). Dedicated transgender-friendly programs are effective at reducing HIV risks and require expansion to better serve this key population and improve HIV prevention strategies. 相似文献
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Kimberly A. Aeling Kirsty A. Salmon José M. Laplaza Ling Li Jennifer R. Headman Alex H. Hutagalung Stephen Picataggio 《Journal of industrial microbiology & biotechnology》2012,39(11):1597-1604
We have integrated and coordinately expressed in Saccharomyces cerevisiae a xylose isomerase and cellobiose phosphorylase from Ruminococcus flavefaciens that enables fermentation of glucose, xylose, and cellobiose under completely anaerobic conditions. The native xylose isomerase was active in cell-free extracts from yeast transformants containing a single integrated copy of the gene. We improved the activity of the enzyme and its affinity for xylose by modifications to the 5′-end of the gene, site-directed mutagenesis, and codon optimization. The improved enzyme, designated RfCO*, demonstrated a 4.8-fold increase in activity compared to the native xylose isomerase, with a Km for xylose of 66.7?mM and a specific activity of 1.41?μmol/min/mg. In comparison, the native xylose isomerase was found to have a Km for xylose of 117.1?mM and a specific activity of 0.29?μmol/min/mg. The coordinate over-expression of RfCO* along with cellobiose phosphorylase, cellobiose transporters, the endogenous genes GAL2 and XKS1, and disruption of the native PHO13 and GRE3 genes allowed the fermentation of glucose, xylose, and cellobiose under completely anaerobic conditions. Interestingly, this strain was unable to utilize xylose or cellobiose as a sole carbon source for growth under anaerobic conditions, thus minimizing yield loss to biomass formation and maximizing ethanol yield during their fermentation. 相似文献
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Aging of the global world population both in developed and developing countries, an unbalanced male-female ratio within this elderly population, increasing populations – including elderly – within urban areas, all will have a marked effect on the practice of dentistry. Furthermore, major epidemiological changes occurring in the dental field, including an increasing dentition life expectancy, increasing root caries prevalence, decreasing coronal caries rates in children, and the relative increase in the prevalence of periodontal problems will have further impact on the dental care system. Major changes need to be anticipated both at the level of the care provider, including the dentist, the hygienist and the dental assistant, and at the level of the potential patient, especially among the geriatric population, if the profession is to be prepared to adequately address these issues. 相似文献
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Paul L. Wood Tadimeti S. Rao Smriti Iyengar Thomas Lanthorn Joseph Monahan Alex Cordi Eric Sun Michael Vazquez Nancy Gray Patricia Contreras 《Neurochemical research》1990,15(2):217-230
Conclusions Current neurochemical studies of the NMDA receptor macromolecular complex are yielding new insights into the interactions of the subunits of this complex and the associated potential clinical benefits of selective modulation of these subnits. Such studies offer the great potential for a new generation of pharmacotherapies for a wide range of CNS disorders, including stroke, a condition for which there is currently no effective pharmacological treatment. However, it is essential to understand that the first generation products in this area may not be optimal pharmacotherapies, such that haracterization of possible receptor subtypes and understanding the molecular biology of the component proteins of the receptor complex will be crucial in the design of the optimal pharmacological modulators of the NMDA receptor complex.Special issue dedicated to Dr. Erminio Costa 相似文献
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A system for the inducible secretion of proteins from Bacillus subtilis during logarithmic growth 总被引:1,自引:0,他引:1
Alex Edelman Gwennaël Joliff ré Klier Georges Rapoport 《FEMS microbiology letters》1988,52(1-2):117-120
Abstract A Bacillus subtilis-Escherichia coli shuttle vector was constructed containing the B. subtilis levansucrase gene promoter and region encoding its signal sequence.
A site for the restriction enzyme Nae I was included to facilitate precise translational fusions to the DNA encoding the levansucrase signal sequence. Fusions of TEM β-lactamase to this construct displayed sucrose-inducible expression and secretion of B. subtilis . 相似文献
A site for the restriction enzyme Nae I was included to facilitate precise translational fusions to the DNA encoding the levansucrase signal sequence. Fusions of TEM β-lactamase to this construct displayed sucrose-inducible expression and secretion of B. subtilis . 相似文献