全文获取类型
收费全文 | 344篇 |
免费 | 28篇 |
出版年
2022年 | 3篇 |
2018年 | 3篇 |
2016年 | 4篇 |
2015年 | 8篇 |
2014年 | 9篇 |
2013年 | 21篇 |
2012年 | 21篇 |
2011年 | 19篇 |
2010年 | 19篇 |
2009年 | 14篇 |
2008年 | 8篇 |
2007年 | 15篇 |
2006年 | 17篇 |
2005年 | 14篇 |
2004年 | 14篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 14篇 |
2000年 | 13篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 3篇 |
1995年 | 4篇 |
1992年 | 3篇 |
1991年 | 2篇 |
1990年 | 3篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 6篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1966年 | 2篇 |
1951年 | 4篇 |
1927年 | 2篇 |
1925年 | 2篇 |
1920年 | 2篇 |
1917年 | 2篇 |
1914年 | 2篇 |
1912年 | 3篇 |
1911年 | 7篇 |
1910年 | 2篇 |
1909年 | 4篇 |
1908年 | 5篇 |
1907年 | 3篇 |
1906年 | 4篇 |
1905年 | 3篇 |
排序方式: 共有372条查询结果,搜索用时 218 毫秒
51.
52.
53.
54.
55.
56.
The relationships between uric acid and chronic disease risk factors such as metabolic syndrome, type 2 diabetes mellitus, and hypertension have been studied in adults. However, whether these relationships exist in adolescents is unknown. We randomly selected 8,005 subjects who were between 10 to 15 years old at baseline. Measurements of uric acid were used to predict the future occurrence of metabolic syndrome, hypertension, and type 2 diabetes. In total, 5,748 adolescents were enrolled and followed for a median of 7.2 years. Using cutoff points of uric acid for males and females (7.3 and 6.2 mg/dl, respectively), a high level of uric acid was either the second or third best predictor for hypertension in both genders (hazard ratio: 2.920 for males, 5.222 for females; p<0.05). However, uric acid levels failed to predict type 2 diabetes mellitus, and only predicted metabolic syndrome in males (hazard ratio: 1.658; p<0.05). The same results were found in multivariate adjusted analysis. In conclusion, a high level of uric acid indicated a higher likelihood of developing hypertension in both genders and metabolic syndrome in males after 10 years of follow-up. However, uric acid levels did not affect the occurrence of type 2 diabetes in both genders. 相似文献
57.
Negative regulation of yeast telomerase activity through an interaction with an upstream region of the DNA primer. 总被引:10,自引:5,他引:5
下载免费PDF全文
![点击此处可从《Nucleic acids research》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A number of published studies indicate that telomerase may interact with oligonucleotide primers in a bipartite manner, with the 3'-end of the primer positioned at the catalytic site of the enzyme and a more 5' region of the primer binding to a second or 'anchor' site of the enzyme. We systematically investigated the effects of mutations in the DNA primer on overall binding and polymerization by yeast telomerase. Our studies indicate that there is sequence-specific interaction between telomerase and a substantial region of the DNA primer. Mutations in the 3'-most positions of the primer reduced polymerization, yet had little effect on overall binding affinity. In contrast, mutations around the -20 position reduced binding affinity but had no effect on polymerization. Most strikingly, mutations centered around the -12 position of the DNA primer reduced overall binding affinity but dramatically enhanced primer extension, as well as primer cleavage. This finding suggests that reduced interaction with the -12 region of the DNA primer can facilitate a step in the catalytic region of yeast telomerase that leads to greater polymerization. A tripartite model of interaction between primer and telomerase is proposed to account for the distinct effects of mutations in different regions of the DNA primer. 相似文献
58.
59.
60.