全文获取类型
收费全文 | 2105篇 |
免费 | 221篇 |
国内免费 | 9篇 |
专业分类
2335篇 |
出版年
2022年 | 27篇 |
2021年 | 33篇 |
2020年 | 25篇 |
2019年 | 47篇 |
2018年 | 43篇 |
2017年 | 54篇 |
2016年 | 58篇 |
2015年 | 86篇 |
2014年 | 90篇 |
2013年 | 124篇 |
2012年 | 116篇 |
2011年 | 135篇 |
2010年 | 99篇 |
2009年 | 84篇 |
2008年 | 93篇 |
2007年 | 106篇 |
2006年 | 105篇 |
2005年 | 96篇 |
2004年 | 86篇 |
2003年 | 64篇 |
2002年 | 74篇 |
2001年 | 62篇 |
2000年 | 64篇 |
1999年 | 49篇 |
1998年 | 23篇 |
1997年 | 17篇 |
1996年 | 14篇 |
1995年 | 19篇 |
1994年 | 11篇 |
1993年 | 10篇 |
1992年 | 46篇 |
1991年 | 30篇 |
1990年 | 27篇 |
1989年 | 34篇 |
1988年 | 25篇 |
1987年 | 19篇 |
1986年 | 17篇 |
1985年 | 26篇 |
1984年 | 16篇 |
1983年 | 18篇 |
1981年 | 8篇 |
1980年 | 13篇 |
1979年 | 8篇 |
1978年 | 15篇 |
1975年 | 10篇 |
1974年 | 12篇 |
1973年 | 17篇 |
1972年 | 11篇 |
1971年 | 7篇 |
1968年 | 8篇 |
排序方式: 共有2335条查询结果,搜索用时 15 毫秒
991.
992.
993.
Mei Zhuang Wuwen Zhang Nuo Cheng Ling Zhou Dan Liu Hua Yan Ge Fang Boon Chin Heng Yan Sun Guoqing Tong 《Acta biochimica et biophysica Sinica》2022,(1):148-151
Due to the influence of various social and environmental factors,the incidence of infertility is increasing,and the application of assisted reproductive technol... 相似文献
994.
Anne Dallas Heini Ilves Han Ma Daniel J. Chin Ian MacLachlan Klaus Klumpp Brian H. Johnston 《Journal of virology》2014,88(9):4647-4656
995.
Chin Fung Kelvin Kan Amar Bahadur Singh Diana M. Stafforini Salman Azhar Jingwen Liu 《Journal of lipid research》2014,55(8):1657-1667
ACSL4 is a member of the long-chain acyl-CoA synthetase (ACSL) family with a marked preference for arachidonic acid (AA) as its substrate. Although an association between elevated levels of ACSL4 and hepatosteatosis has been reported, the function of ACSL4 in hepatic FA metabolism and the regulation of its functional expression in the liver remain poorly defined. Here we provide evidence that AA selectively downregulates ACSL4 protein expression in hepatic cells. AA treatment decreased the half-life of ACSL4 protein in HepG2 cells by approximately 4-fold (from 17.3 ± 1.8 h to 4.2 ± 0.4 h) without causing apoptosis. The inhibitory action of AA on ACSL4 protein stability could not be prevented by rosiglitazone or inhibitors that interfere with the cellular pathways involved in AA metabolism to biologically active compounds. In contrast, treatment of cells with inhibitors specific for the proteasomal degradation pathway largely prevented the AA-induced ACSL4 degradation. We further show that ACSL4 is intrinsically ubiquitinated and that AA treatment can enhance its ubiquitination. Collectively, our studies have identified a novel substrate-induced posttranslational regulatory mechanism by which AA downregulates ACSL4 protein expression in hepatic cells. 相似文献
996.
997.
998.
999.
Advances in fluorescence live cell imaging over the last decade have revolutionized cell biology by providing access to single-cell information in space and time. One current limitation of live-cell imaging is the lack of automated procedures to analyze single-cell data in large cell populations. Most commercially available image processing softwares do not have built-in image segmentation tools that can automatically and accurately extract single-cell data in a time series. Consequently, individual cells are usually identified manually, a process which is time consuming and inherently low-throughput. We have developed a MATLAB-based image segmentation algorithm that reliably detects individual cells in dense populations and measures their fluorescence intensity over time. To demonstrate the value of this algorithm, we measured store-operated calcium entry (SOCE) in hundreds of individual cells. Rapid access to single-cell calcium signals in large populations allowed us to precisely determine the relationship between SOCE activity and STIM1 levels, a key component of SOCE. Our image processing tool can in principle be applied to a wide range of live-cell imaging modalities and cell-based drug screening platforms. 相似文献
1000.
Wai Kiong Ng Jin Wang Kwek Aaron Yuen Chin Lee Tan Reginald Tan 《AAPS PharmSciTech》2010,11(1):159-167
The purpose of this research was to investigate why and how mechanical milling results in an unexpected shift in differential
scanning calorimetry (DSC) measured fusion enthalpy (∆fus
H) and melting point (T
m) of adipic acid, a pharmaceutical excipient. Hyper differential scanning calorimetry (hyper-DSC) was used to characterize
adipic acid before and after ball-milling. An experimental study was conducted to evaluate previous postulations such as electrostatic
charging using the Faraday cage method, crystallinity loss using powder X-ray diffraction (PXRD), thermal annealing using
DSC, impurities removal using thermal gravimetric analysis (TGA) and Karl Fischer titration. DSC thermograms showed that after
milling, the values of ∆fus
H and T
m were increased by approximately 9% and 5 K, respectively. Previous suggestions of increased electrostatic attraction, change
in particle size distribution, and thermal annealing during measurements did not explain the differences. Instead, theoretical
analysis and experimental findings suggested that the residual solvent (water) plays a key role. Water entrapped as inclusions
inside adipic acid during solution crystallization was partially evaporated by localized heating at the cleaved surfaces during
milling. The correlation between the removal of water and melting properties measured was shown via drying and crystallization
experiments. These findings show that milling can reduce residual solvent content and causes a shift in DSC results. 相似文献