全文获取类型
收费全文 | 59篇 |
免费 | 1篇 |
出版年
2021年 | 1篇 |
2017年 | 1篇 |
2014年 | 2篇 |
2013年 | 1篇 |
2012年 | 3篇 |
2010年 | 3篇 |
2009年 | 3篇 |
2008年 | 6篇 |
2007年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 2篇 |
1995年 | 2篇 |
1993年 | 1篇 |
1990年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1971年 | 1篇 |
1959年 | 2篇 |
1958年 | 2篇 |
1957年 | 4篇 |
1956年 | 3篇 |
1954年 | 1篇 |
1953年 | 3篇 |
1952年 | 1篇 |
1950年 | 1篇 |
1949年 | 1篇 |
1948年 | 1篇 |
1947年 | 2篇 |
排序方式: 共有60条查询结果,搜索用时 593 毫秒
21.
22.
Ajay K Mishra Amita Mishra HK Kehri Bechan Sharma Abhay K Pandey 《Annals of clinical microbiology and antimicrobials》2009,8(1):1-7
Background
Enteric fever is an endemic problem in Nepal and Widal agglutination test is widely used for its diagnosis but a normal baseline titer in healthy population and cutoff values have not been established.Methods
We measured average baseline antibody titers against "O" and "H" antigens of Salmonella enterica serotype Typhi and "H" antigens of serotypes Paratyphi A and Paratyphi B among apparently healthy blood donors in Nepal. The antibody titers were measured using Standard Widal Confirmatory Quantitative Tube test.Results
Among the 100 blood samples collected from healthy volunteers, 62 individuals had significant antibody titers (≥ 1:20) against one of the four antigens against S. enterica. Among 54 samples with an anti-O titer against serotype Typhi, 15 and 36 samples had titers of ≥ 1:60 and ≥ 1:40, respectively. A significant proportion (12% of all) had anti-O titer of ≥ 1:80. Similarly, among the 59 samples demonstrating anti-H titers of ≥ 1:20 to S. enterica serotype Typhi, 29 had a titer of ≥ 1:80 and 12 had 1:160. For S. enterica serotypes Paratyphi A and B, anti-H titers of ≥ 1:20 were found only in 12% and 3%, respectively, of all samples tested.Conclusion
When a single Widal agglutination titer is used for the diagnosis of enteric fever, it will be more appropriate to change the currently used cutoff levels against S. enterica serotype Typhi to > 1:80 for anti-O and > 1:160 for anti-H titers for Nepal. 相似文献23.
The northeast region of India, considered as 'hot spot' of biodiversity, having unique ecological environment with hot and high-humidity conditions, has given rise to the world's hottest chilli, 'Bhut Jolokia', which is at least two times hotter than Red Savina Habanero in terms of Scoville heat units (SHU). This study was undertaken to determine the distinctiveness of 'Bhut Jolokia' from Capsicum frutescens or Capsicum chinense through sequencing of the ribosomal RNA (rRNA) gene-internal transcribed ((ITS) region along with its phylogenetic analysis. Although a compensatory base change (CBC) in the ITS2 region was not observed between the closely related species of C. frutescens and C. chinense when compared with Bhut Jolokia; phylogenetic analysis using ITS1, 5.8S and ITS2 sequences indicated a distinct clade for all the accessions of 'Bhut Joloikia', while C. frutescens and C. chinense occupied discrete lineages. Further, a unique 13-base deletion was observed in all the representative accessions of 'Bhut Jolokia', making it distinct from all other members within the genus and beyond. The degree of genetic variations along with its extreme pungency might be related to ambient environmental factors of northeastern India. 相似文献
24.
25.
The sensitivity of annual grassland carbon cycling to the quantity and timing of rainfall 总被引:1,自引:0,他引:1
WENDY W. CHOU WHENDEE L. SILVER RANDALL D. JACKSON† REW W. THOMPSON BARBARA ALLEN-DIAZ 《Global Change Biology》2008,14(6):1382-1394
Global climate models predict significant changes to the rainfall regimes of the grassland biome, where C cycling is particularly sensitive to the amount and timing of precipitation. We explored the effects of both natural interannual rainfall variability and experimental rainfall additions on net C storage and loss in annual grasslands. Soil respiration and net primary productivity (NPP) were measured in treatment and control plots over four growing seasons (water years, or WYs) that varied in wet‐season length and the quantity of rainfall. In treatment plots, we increased total rainfall by 50% above ambient levels and simulated one early‐ and one late‐season storm. The early‐ and late‐season rain events significantly increased soil respiration for 2–4 weeks after wetting, while augmentation of wet‐season rainfall had no significant effect. Interannual variability in precipitation had large and significant effects on C cycling. We observed a significant positive relationship between annual rainfall and aboveground NPP across the study (P=0.01, r2=0.69). Changes in the seasonal timing of rainfall significantly affected soil respiration. Abundant rainfall late in the wet season in WY 2004, a year with average total rainfall, led to greater net ecosystem C losses due to a ~50% increase in soil respiration relative to other years. Our results suggest that C cycling in annual grasslands will be less sensitive to changes in rainfall quantity and more affected by altered seasonal timing of rainfall, with a longer or later wet season resulting in significant C losses from annual grasslands. 相似文献
26.
SILVER HK 《California medicine》1952,76(3):162-164
There are two forms of Mediterranean anemia, one mild, the other severe. The major variety is characterized by pronounced anemia and systemic changes. In the minor form, usually there is no anemia or other clinical abnormality. The milder disease is relatively common in Italians, but both forms may occur in persons of non-Mediterranean ancestry, as well as in those who come from areas adjoining the Mediterranean Sea. Diagnosis of the disease is made on the basis of history, clinical observation, roentgen studies of the bones, and exceptionally painstaking laboratory tests. Periodic transfusions of whole blood are necessary for persons with the more severe form of the disease. 相似文献
27.
28.
29.
30.