全文获取类型
收费全文 | 15476篇 |
免费 | 1409篇 |
国内免费 | 1465篇 |
专业分类
18350篇 |
出版年
2024年 | 41篇 |
2023年 | 203篇 |
2022年 | 430篇 |
2021年 | 660篇 |
2020年 | 524篇 |
2019年 | 616篇 |
2018年 | 561篇 |
2017年 | 445篇 |
2016年 | 629篇 |
2015年 | 974篇 |
2014年 | 1097篇 |
2013年 | 1153篇 |
2012年 | 1505篇 |
2011年 | 1319篇 |
2010年 | 821篇 |
2009年 | 744篇 |
2008年 | 888篇 |
2007年 | 768篇 |
2006年 | 758篇 |
2005年 | 604篇 |
2004年 | 497篇 |
2003年 | 444篇 |
2002年 | 383篇 |
2001年 | 227篇 |
2000年 | 214篇 |
1999年 | 206篇 |
1998年 | 154篇 |
1997年 | 123篇 |
1996年 | 101篇 |
1995年 | 108篇 |
1994年 | 113篇 |
1993年 | 73篇 |
1992年 | 99篇 |
1991年 | 84篇 |
1990年 | 62篇 |
1989年 | 66篇 |
1988年 | 51篇 |
1987年 | 46篇 |
1986年 | 49篇 |
1985年 | 50篇 |
1984年 | 38篇 |
1983年 | 31篇 |
1982年 | 36篇 |
1981年 | 25篇 |
1980年 | 24篇 |
1978年 | 24篇 |
1976年 | 25篇 |
1975年 | 23篇 |
1974年 | 19篇 |
1973年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Jiajia Ma Zijia Ren Yang Ma Lu Xu Ying Zhao Chaogu Zheng Yinghui Fang Ting Xue Baolin Sun Weihua Xiao 《The Journal of biological chemistry》2009,284(50):34600-34606
52.
53.
Rodearmel SJ Wyatt HR Barry MJ Dong F Pan D Israel RG Cho SS McBurney MI Hill JO 《Obesity (Silver Spring, Md.)》2006,14(8):1392-1401
Objective: Preventing weight gain in adults and excessive weight gain in children is a high priority. We evaluated the ability of a family‐based program aimed at increasing steps and cereal consumption (for breakfast and snacks) to reduce weight gain in children and adults. Research Methods and Procedures: Families (n = 105) with at least one 8‐ to 12‐year‐old child who was at‐risk‐for‐overweight or overweight (designated as the target child) were recruited for the study. Eighty‐two families were randomly assigned to receive the family‐based intervention and 23 families to the control condition. The 13‐week intervention consisted of specific increases in daily steps (an additional 2000 steps/d) and consumption of 2 servings/d of ready‐to‐eat cereal. Results: The intervention was successful in increasing walking (steps) and cereal consumption. The intervention had positive, significant effects on percentage BMI‐for‐age and percentage body fat for target children and weight, BMI, and percentage body fat for parents. On further analysis, the positive effects of the intervention were seen largely in target girls and moms, rather than in target boys and dads. Discussion: This family‐based weight gain prevention program based on small changes holds promise for reducing excessive weight gain in families and especially in growing overweight children. 相似文献
54.
Zhang Hao Qing Zhao Xue Qiang Chen Yi Ling Zhang Ling Yu Shen Ren Fang 《Plant and Soil》2019,439(1-2):293-308
Plant and Soil - Biocrusts are important functional units in dryland ecosystems. Regarded as ecosystem engineers, cyanobacteria in biocrusts contribute several major physico-chemical and biological... 相似文献
55.
56.
57.
This article summarizes the current understanding of known variant forms of the MGMT gene that encode an altered protein. Epidemiological studies have been carried out to test whether these alterations are associated with altered cancer risk. Laboratory studies using recombinant proteins and cells expressing the known variants have investigated the possible effects of these sequence alterations on the ability of the encoded O(6)-alkylguanine-DNA alkyltransferase protein to protect cells from alkylation damage and to respond to therapeutic inactivators currently undergoing trials for cancer chemotherapy. 相似文献
58.
The resonant recognition model (RRM) predicts amino acid residues in highly conserved regions of the hormone prolactin (PRL) 总被引:2,自引:0,他引:2
The resonant recognition model (RRM) is a model which treats the protein sequence as a discrete signal. It has been shown previously that certain periodicities (frequencies) in this signal characterise protein biological function. The RRM was employed to determine the characteristic frequencies of the hormone prolactin (PRL), and to identify amino acids ('hot spots') mostly contributing to these frequencies and thus proposed to mostly contribute to the biological function. The predicted 'hot spot' amino acids, Phe-19, Ser-26, Ser-33, Phe-37, Phe-40, Gly-47, Gly-49, Phe-50, Ser-61, Gly-129, Arg-176, Arg-177, Cys-191 and Arg-192 are found in the highly conserved amino-terminal and C-terminus regions of PRL. Our predictions agree with previous experimentally tested residues by site-direct mutagenesis and photoaffinity labelling. 相似文献
59.
Chiakang Ho Ya Gao Danning Zheng Yanjun Liu Shengzhou Shan Bin Fang Yixuan Zhao Dingzhong Song Yifan Zhang Qingfeng Li 《Journal of cellular and molecular medicine》2019,23(8):5108-5118
Obesity and its associated metabolic disorders such as diabetes, hepatic steatosis and chronic heart diseases are affecting billions of individuals. However there is no satisfactory drug to treat such diseases. In this study, we found that alisol A, a major active triterpene isolated from the Chinese traditional medicine Rhizoma Alismatis, could significantly attenuate high‐fat‐diet‐induced obesity. Our biochemical detection demonstrated that alisol A remarkably decreased lipid levels, alleviated glucose metabolism disorders and insulin resistance in high‐fat‐diet‐induced obese mice. We also found that alisol A reduced hepatic steatosis and improved liver function in the obese mice model.In addition, protein expression investigation revealed that alisol A had an active effect on AMPK/ACC/SREBP‐1c pathway. As suggested by the molecular docking study, such bioactivity of alisol A may result from its selective binding to the catalytic region of AMPK.Therefore, we believe that Alisol A could serve as a promising agent for treatment of obesity and its related metabolic diseases. 相似文献