全文获取类型
收费全文 | 141篇 |
免费 | 12篇 |
出版年
2023年 | 2篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 1篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 10篇 |
2013年 | 14篇 |
2012年 | 12篇 |
2011年 | 10篇 |
2010年 | 10篇 |
2009年 | 6篇 |
2008年 | 6篇 |
2007年 | 7篇 |
2006年 | 13篇 |
2005年 | 12篇 |
2004年 | 2篇 |
2003年 | 6篇 |
2002年 | 3篇 |
2001年 | 2篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1998年 | 1篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1984年 | 1篇 |
1972年 | 1篇 |
1968年 | 2篇 |
排序方式: 共有153条查询结果,搜索用时 15 毫秒
61.
Edwards T Smith J Sturrock HJ Kur LW Sabasio A Finn TP Lado M Haddad D Kolaczinski JH 《PLoS neglected tropical diseases》2012,6(4):e1585
Background
Large parts of South Sudan are thought to be trachoma-endemic but baseline data are limited. This study aimed to estimate prevalence for planning trachoma interventions in Unity State, to identify risk factors and to investigate the effect of different sampling approaches on study conclusions.Methods and Findings
The survey area was defined as one domain of eight counties in Unity State. Across the area, 40 clusters (villages) were randomly selected proportional to the county population size in a population-based prevalence survey. The simplified grading scheme was used to classify clinical signs of trachoma. The unadjusted prevalence of trachoma inflammation-follicular (TF) in children aged 1–9 years was 70.5% (95% CI: 68.6–72.3). After adjusting for age, sex, county and clustering of cases at household and village level the prevalence was 71.0% (95% CI: 69.9–72.1). The prevalence of trachomatous trichiasis (TT) in adults was 15.1% (95% CI: 13.4–17.0) and 13.5% (95% CI: 12.0–15.1) before and after adjustment, respectively. We estimate that 700,000 people (the entire population of Unity State) require antibiotic treatment and approximately 54,178 people require TT surgery. Risk factor analyses confirmed child-level associations with TF and highlighted that older adults living in poverty are at higher risk of TT. Conditional simulations, testing the alternatives of sampling 20 or 60 villages over the same area, indicated that sampling of only 20 villages would have provided an acceptable level of precision for state-level prevalence estimation to inform intervention decisions in this hyperendemic setting.Conclusion
Trachoma poses an enormous burden on the population of Unity State. Comprehensive control is urgently required to avoid preventable blindness and should be initiated across the state now. In other parts of South Sudan suspected to be highly trachoma endemic, counties should be combined into larger survey areas to generate the baseline data required to initiate interventions. 相似文献62.
63.
Wang W Préville P Morin N Mounir S Cai W Siddiqui MA 《Bioorganic & medicinal chemistry letters》2000,10(11):1151-1154
An in vitro assay based on the expression of Fluci reporter gene under the translational control of HCV IRES was used to evaluate and screen compound libraries. A structure-activity relationship study on a phenazine hit was conducted. Our data suggest that an intact phenazine or phenazine-like core with two distal polar substitutions is crucial for potency. 相似文献
64.
Thirteen Cuvier’s gazelles were relocated to a 6-ha acclimatization enclosure in Boukornine National Park (Boukornine NP)
in Tunisia, where they are part of a reintroduction project. To determine the degree of adaptation and habitat use under the
new conditions, the acclimatization enclosure was divided into 6 sections according to topography, plant cover and plant species
in the area. Signs of gazelle activity were coded as feeding site, paths, passages, feces and resting places. Sampling was
done in spring, summer and autumn from September 2000 to July 2001. Multivariate analysis using PATN analysis and Χ2 distribution tests were used to analyze the data. Multivariate analysis yielded 5 groups of biotopes according to the above
variables. The Χ2 distribution test showed the significant effect of each variable on the presence of signs of gazelles. Cuvier’s gazelles
prefer areas with low and west to north facing slopes and scant plant cover; animals are attracted to the proximity of the
fence as the limit of their territory and even though the presence of humans does not represent a disturbance, gazelles select
areas far (> 50 m) from the supplementary feeding and water supply for their activities. 相似文献
65.
Small heat shock proteins (sHsps) are a ubiquitous part of the machinery that maintains cellular protein homeostasis by acting as molecular chaperones. sHsps bind to and prevent the aggregation of partially folded substrate proteins in an ATP-independent manner. sHsps are dynamic, forming an ensemble of structures from dimers to large oligomers through concentration-dependent equilibrium dissociation. Based on structural studies and mutagenesis experiments, it is proposed that the dimer is the smallest active chaperone unit, while larger oligomers may act as storage depots for sHsps or play additional roles in chaperone function. The complexity and dynamic nature of their structural organization has made elucidation of their chaperone function challenging. HspB1 and HspB5 are two canonical human sHsps that vary in sequence and are expressed in a wide variety of tissues. In order to determine the role of the dimer in chaperone activity, glutathione-S-transferase (GST) was genetically linked as a fusion protein to the N-terminus regions of both HspB1 and HspB5 (also known as Hsp27 and αB-crystallin, respectively) proteins in order to constrain oligomer formation of HspB1 and HspB5, by using GST, since it readily forms a dimeric structure. We monitored the chaperone activity of these fusion proteins, which suggest they primarily form dimers and monomers and function as active molecular chaperones. Furthermore, the two different fusion proteins exhibit different chaperone activity for two model substrate proteins, citrate synthase (CS) and malate dehydrogenase (MDH). GST-HspB1 prevents more aggregation of MDH compared to GST-HspB5 and wild type HspB1. However, when CS is the substrate, both GST-HspB1 and GST-HspB5 are equally effective chaperones. Furthermore, wild type proteins do not display equal activity toward the substrates, suggesting that each sHsp exhibits different substrate specificity. Thus, substrate specificity, as described here for full-length GST fusion proteins with MDH and CS, is modulated by both sHsp oligomeric conformation and by variations of sHsp sequences. 相似文献
66.
Mustafa A. S. Gouda Prof. Mounir A. I. Salem Prof. Magda I. Marzouk Prof. Naglaa F. H. Mahmoud Dr. Mahmoud F. Ismail 《化学与生物多样性》2023,20(7):e202300706
N′-[(4-Chloro-2-oxo-2H-chromen-3-yl)methylene]-2-cyanoacetohydrazide ( 3 ) was synthesized in excellent yield from the condensation of 4-Chloro-2-oxo-2H-chromene-3-carbaldehyde with cyanoacetohydrazide. Compound 3 was utilized as a building block to synthesize novel coumarin and heterocycle-fused coumarin derivatives. The chemical structures of all the new coumarin compounds were identified by spectral analyses. Some of the new coumarins compounds were screened in human cancer cell lines (HEPG-2, MCF-7, HCT-116 and PC-3) to learn about their cytotoxic effects in addition to the study of their DNA damage and antioxidant activity. Three of these compounds exhibited remarkable antioxidant and anti-proliferative activities. Moreover, they have the capability to protect DNA from damage induced by bleomycin. Molecular docking, DFT and molecular electrostatic potential studies were performed on the compounds in vitro. 相似文献
67.
68.
Nitraria retusa and Atriplex halimus (xero-halophytes) plants were grown in the range 0–800 mM NaCl while Medicago arborea (glycophyte) in 0–300 mM NaCl. Salt stress caused a marked decrease in osmotic potential and a significant accumulation of
Na+ and Cl− in leaves of both species. Moderate salinity had a stimulating effect on growth rate, net CO2 assimilation, transpiration and stomatal conductance for the xero-halophytic species. At higher salinities, these physiological
parameters decreased significantly, and their percentages of reduction were higher in A. halimus than in N. retusa whereas, in M. arborea they decreased linearly with salinity. Nitraria retusa PSII photochemistry and carotenoid content were unaffected by salinity, but a reduction in chlorophyll content was observed
at 800 mM NaCl. Similar results were found in A. halimus, but with a decrease in the efficiency of PSII (F′v/F′m) occurred at 800 mM. Conversely, in M. arborea plants we observed a significant reduction in pigment concentrations and chlorophyll fluorescence parameters. The marked
toxic effect of Na+ and/or Cl− observed in M. arborea indicates that salt damage effect could be attributed to ions’ toxicity, and that the reduction in photosynthesis is most
probably due to damages in the photosynthetic apparatus rather than factors affecting stomatal closure. For the two halophyte
species, it appears that there is occurrence of co-limitation of photosynthesis by stomatal and non-stomatal factors. Our
results suggest that both N. retusa and A. halimus show high tolerance to both high salinity and photoinhibition while M. arborea was considered as a slightly salt tolerant species. 相似文献
69.
70.
Archie C. A. Clements Lucia W. Kur Gideon Gatpan Jeremiah M. Ngondi Paul M. Emerson Mounir Lado Anthony Sabasio Jan H. Kolaczinski 《PLoS neglected tropical diseases》2010,4(8)