全文获取类型
收费全文 | 741篇 |
免费 | 57篇 |
出版年
2023年 | 4篇 |
2022年 | 7篇 |
2021年 | 20篇 |
2020年 | 18篇 |
2019年 | 12篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 36篇 |
2015年 | 30篇 |
2014年 | 35篇 |
2013年 | 56篇 |
2012年 | 57篇 |
2011年 | 59篇 |
2010年 | 39篇 |
2009年 | 26篇 |
2008年 | 39篇 |
2007年 | 46篇 |
2006年 | 34篇 |
2005年 | 27篇 |
2004年 | 31篇 |
2003年 | 25篇 |
2002年 | 23篇 |
2001年 | 10篇 |
1999年 | 13篇 |
1998年 | 4篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1993年 | 6篇 |
1992年 | 3篇 |
1991年 | 8篇 |
1990年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 4篇 |
1985年 | 2篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 10篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1975年 | 10篇 |
1974年 | 8篇 |
1973年 | 7篇 |
1972年 | 3篇 |
1971年 | 2篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有798条查询结果,搜索用时 15 毫秒
61.
Anjana Bhardwaj Nivetha Ganesan Kazunoshin Tachibana Kimal Rajapakshe Constance T. Albarracin Preethi H. Gunaratne Cristian Coarfa Isabelle Bedrosian 《PloS one》2015,10(5)
IntroductionAnnexin A1 (ANXA1) is an anti-inflammatory protein reported to play a role in cell proliferation and apoptosis, and to be deregulated in breast cancer. The exact role of annexin A1 in the biology of breast cancer remains unclear. We hypothesized that the annexin A1 plays an oncogenic role in basal subtype of breast cancer by modulating key growth pathway(s).MethodsBy mining the Cancer Genome Atlas (TCGA)-Breast Cancer dataset and manipulating annexin A1 levels in breast cancer cell lines, we studied the role of annexin A1 in breast cancer and underlying signaling pathways.ResultsOur in-silico analysis of TCGA-breast cancer dataset demonstrated that annexin A1 mRNA expression is higher in basal subtype compared to luminal and HER2 subtypes. Within the basal subtype, patients show significantly poorer overall survival associated with higher expression of annexin A1. In both TCGA patient samples and cell lines, annexin A1 levels were significantly higher in basal-like breast cancer than luminal and Her2/neu-positive breast cancer. Stable annexin A1 knockdown in TNBC cell lines suppressed the mTOR-S6 pathway likely through activation of AMPK but had no impact on the MAPK, c-Met, and EGFR pathways. In a cell migration assay, annexin A1-depleted TNBC cells showed delayed migration as compared to wild-type cells, which could be responsible for poor patient prognosis in basal like breast cancers that are known to express higher annexin A1.ConclusionsOur data suggest that annexin A1 is prognostic only in patients with basal like breast cancer. This appears to be in part due to the role of annexin A1 in activating mTOR-pS6 pathway. 相似文献
62.
In Vivo Assessment of Cold Tolerance through Chlorophyll-a Fluorescence in Transgenic Zoysiagrass Expressing Mutant Phytochrome A 总被引:1,自引:0,他引:1
Mayank Anand Gururani Jelli Venkatesh Markkandan Ganesan Reto J?rg Strasser Yunjeong Han Jeong-Il Kim Hyo-Yeon Lee Pill-Soon Song 《PloS one》2015,10(5)
Chlorophyll-a fluorescence analysis provides relevant information about the physiology of plants growing under abiotic stress. In this study, we evaluated the influence of cold stress on the photosynthetic machinery of transgenic turfgrass, Zoysia japonica, expressing oat phytochrome A (PhyA) or a hyperactive mutant phytochrome A (S599A) with post-translational phosphorylation blocked. Biochemical analysis of zoysiagrass subjected to cold stress revealed reduced levels of hydrogen peroxide, increased proline accumulation, and enhanced specific activities of antioxidant enzymes compared to those of control plants. Detailed analyses of the chlorophyll-a fluorescence data through the so-called OJIP test exhibited a marked difference in the physiological status among transgenic and control plants. Overall, these findings suggest an enhanced level of cold tolerance in S599A zoysiagrass cultivars as reflected in the biochemical and physiological analyses. Further, we propose that chlorophyll-a fluorescence analysis using OJIP test is an efficient tool in determining the physiological status of plants under cold stress conditions. 相似文献
63.
Jaideep Banerjee Piya Das Ghatak Sashwati Roy Savita Khanna Craig Hemann Binbin Deng Amitava Das Jay L. Zweier Daniel Wozniak Chandan K. Sen 《PloS one》2015,10(3)
Pseudomonas aeruginosa biofilm is commonly associated with chronic wound infection. A FDA approved wireless electroceutical dressing (WED), which in the presence of conductive wound exudate gets activated to generate electric field (0.3–0.9V), was investigated for its anti-biofilm properties. Growth of pathogenic P. aeruginosa strain PAO1 in LB media was markedly arrested in the presence of the WED. Scanning electron microscopy demonstrated that WED markedly disrupted biofilm integrity in a setting where silver dressing was ineffective. Biofilm thickness and number of live bacterial cells were decreased in the presence of WED. Quorum sensing genes lasR and rhlR and activity of electric field sensitive enzyme, glycerol-3-phosphate dehydrogenase was also repressed by WED. This work provides first electron paramagnetic resonance spectroscopy evidence demonstrating that WED serves as a spontaneous source of reactive oxygen species. Redox-sensitive multidrug efflux systems mexAB and mexEF were repressed by WED. Taken together, these observations provide first evidence supporting the anti-biofilm properties of WED. 相似文献
64.
65.
66.
Amylase inhibitor producing actinobacteria were isolated and characterized from terrestrial environment and there is no much
report found from marine environment, hence in the present study, 17 strains isolated from the rhizosphere sediments of mangroves
were tested for their amylase inhibition ability. Seawater requirement test for the growth of actinobacteria found that the
strains SSR-3, SSR-12 and SSR-16 requires at least 50% and SSR-6 requires at least 25% seawater for their growth. The inhibition
activity of both prokaryotic and eukaryotic amylase was tested by using Bacillus subtilis and Aspergillus niger. The maximum amylase activity (40mm) produced by the A. niger was taken as positive control, when the test actinobacteria strains grown in the medium they inhibited amylase activity and
was evidenced by the reduction in inhibition zone (14–37 mm) similarly the amylase produced by the Bacillus subtilis was also recorded maximum (35 mm) amylase activity and was taken as positive control, and the test atinobacterial strains
reduced enzyme action(12–33 mm) it varied levals. This indicates that the actinobacteria strains were controlled amylase enzyme
activity in both the cases. The strain SSR-10 was highly effective and SSR-8 was less effective in inhibiting eukaryotic amylase
produced by A. niger. The strain SSR-2 was effective and SSR-6 showed very less effect in inhibiting the prokaryotic amylase produced by the B subtilis. 相似文献
67.
Copper has been used as a disinfectant since ancient times and recent research has demonstrated that antimicrobial copper surfaces may have practical applications in healthcare and related areas. The present study was carried out to establish the effects of temperature and pH on inactivation and sub-lethal injury of Escherichia coli in water stored in a copper vessel, to determine the operational limits of the process in terms of these variables. To investigate the effects of temperature, a bacterial suspension at pH 7.0 was stored for up to 48 h in copper vessels at 5, 15, 25 and 35°C. For pH, a bacterial suspension was stored at 30°C for up to 48 h in copper vessels at pH 6.0, 7.0, 8.0 and 9.0. Both temperature and pH had substantial effects on inactivation and injury, with the fastest inactivation observed at elevated temperature and at pH values furthest from neutrality, while the greatest amount of sub-lethal injury, manifest as sensitivity to conventional aerobic enumeration, was observed at a temperature of 35°C. These findings have important implications for the practical application of copper-based water disinfection methods, in terms of their likely efficacy under environmental conditions. 相似文献
68.
69.
Thanemozhi G Natarajan Bhaskar V Kallakury Christine E Sheehan Margaret B Bartlett Natarajan Ganesan Anju Preet Jeffrey S Ross Kevin T FitzGerald 《Cancer cell international》2010,10(1):13
Background
MLL2, an epigenetic regulator in mammalian cells, mediates histone 3 lysine 4 tri-methylation (H3K4me3) through the formation of a multiprotein complex. MLL2 shares a high degree of structural similarity with MLL, which is frequently disrupted in leukemias via chromosomal translocations. However, this structural similarity is not accompanied by functional equivalence. In light of this difference, and previous reports on involvement of epigenetic regulators in malignancies, we investigated MLL2 expression in established cell lines from breast and colon tissues. We then investigated MLL2 in solid tumors of breast and colon by immunohistochemistry, and evaluated potential associations with established clinicopathologic variables. 相似文献70.