全文获取类型
收费全文 | 2014篇 |
免费 | 147篇 |
国内免费 | 2篇 |
出版年
2023年 | 11篇 |
2022年 | 20篇 |
2021年 | 60篇 |
2020年 | 35篇 |
2019年 | 28篇 |
2018年 | 52篇 |
2017年 | 44篇 |
2016年 | 53篇 |
2015年 | 87篇 |
2014年 | 94篇 |
2013年 | 125篇 |
2012年 | 164篇 |
2011年 | 145篇 |
2010年 | 85篇 |
2009年 | 65篇 |
2008年 | 97篇 |
2007年 | 71篇 |
2006年 | 78篇 |
2005年 | 74篇 |
2004年 | 62篇 |
2003年 | 66篇 |
2002年 | 47篇 |
2001年 | 40篇 |
2000年 | 32篇 |
1999年 | 25篇 |
1998年 | 14篇 |
1997年 | 17篇 |
1995年 | 10篇 |
1994年 | 13篇 |
1992年 | 36篇 |
1991年 | 24篇 |
1990年 | 23篇 |
1989年 | 22篇 |
1988年 | 15篇 |
1987年 | 23篇 |
1986年 | 13篇 |
1985年 | 24篇 |
1984年 | 29篇 |
1983年 | 16篇 |
1982年 | 16篇 |
1981年 | 18篇 |
1979年 | 24篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1975年 | 12篇 |
1974年 | 14篇 |
1973年 | 10篇 |
1969年 | 13篇 |
1968年 | 10篇 |
1966年 | 10篇 |
排序方式: 共有2163条查询结果,搜索用时 15 毫秒
161.
Studies in newborn humans have demonstrated alteration in the lipid, phospholipid and cholesterol content when compared with age-matched control. Membrane bound (Na+ + K+)ATPase activity is found to be significantly increased in jaundiced neonates. Alteration in membrane permeability characteristics in jaundiced neonates causes severe microenvironmental changes in red blood cell profile. 相似文献
162.
Hendriks E van Deursen FJ Wilson J Sarkar M Timms M Matthews KR 《Biochemical Society transactions》2000,28(5):531-536
Differentiation between bloodstream and tsetse midgut procyclic forms during the life cycle of the African trypanosome is an attractive model for the analysis of stage-regulated events. In particular, this transformation occurs synchronously, there are well-defined markers for stage-regulated processes and cell lines with specific defects in differentiation have been identified. This combination of tools, combined with the developing Trypanosoma brucei genome database is allowing its underlying controls to be investigated at the molecular and cytological levels. This paper examines some recent discoveries that illuminate some of the key events during trypanosome life-cycle progression. 相似文献
163.
The immunosuppressive drug cyclosporin A (CsA) inhibited the hCRT-1 cDNA-induced creatine uptake in Xenopus oocytes and the endogenous creatine uptake in cultured C(2)C(12) muscle cells in a dose- and time-dependent manner. FK506, another potent immunosuppressant, was unable to mimic the effect of CsA suggesting that the inhibitory effect of CsA was specific. To delineate the mechanism underlying, we investigated the effect of CsA on the K(m) and V(max) of creatine transport and also on the cell surface distribution of the creatine transporter. Although CsA treatment did not affect the K(m) (20-24 microm) for creatine, it significantly decreased the V(max) of creatine uptake in both oocytes and muscle cells. CsA treatment reduced the cell surface expression level of the creatine transporter in the muscle cells by approximately 60% without significantly altering its total expression level, and the reduction in the cell surface expression paralleled the decrease in creatine uptake. Taken together, our results suggest that CsA inhibited creatine uptake by altering the surface abundance of the creatine transporter. We propose that CsA impairs the targeting of the creatine transporter by inhibiting the function of an associated cyclophilin, resulting in an apparent loss in surface expression of the creatine transporter. Our results also suggest that prolonged exposure to CsA may result in chronically creatine-depleted muscle, which may be a cause for the development of CsA-associated clinical myopathies in organ transplant patients. 相似文献
164.
165.
B. K. Gupta U. K. Sarkar S. K. Bhardwaj A. Pal 《Zeitschrift fur angewandte Ichthyologie》2011,27(3):962-964
The present study describes the condition factor, length‐weight and length‐length relationships for an endangered freshwater fish species Ompok pabda (Hamilton) of the family Siluridae from the River Gomti in Northern India. The values of regression parameter b ranged from 2.81 to 3.32 (r2 > 0.90). During the pre‐monsoon, the allometric coefficient b of the LWR was close to isometric value (b = 3.08) allometric (b = 2.87), although it suggested negative allometric growth in monsoon periods while positive growth in post‐monsoon. The condition factor values ranged from 0.672 to 0.744. Results of the present study could be useful to help in conservation and sustainable fisheries management of this endangered species. 相似文献
166.
Ranju Chowdhury Paulo J.C. Favas J. Pratas M. P. Jonathan P. Sankar Ganesh Santosh Kumar Sarkar 《International journal of phytoremediation》2015,17(9):885-894
The work investigates on the potential of ten mangrove species for absorption, accumulation and partitioning of trace metal(loid)s in individual plant tissues (leaves, bark and root/pneumatophore) at two study sites of Indian Sundarban Wetland. The metal(loid) concentration in host sediments and their geochemical characteristics were also considered. Mangrove sediments showed unique potential in many- fold increase for most metal(loid)s than plant tissues due to their inherent physicochemical properties. The ranges of concentration of trace metal(loid)s for As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb and Zn in plant tissue were 0.006–0.31, 0.02–2.97, 0.10–4.80, 0.13–6.49, 4.46–48.30, 9.2–938.1, 0.02–0.13, 9.8–1726, 11–5.41, 0.04–7.64, 3.81–52.20 μg g ?1respectively. The bio- concentration factor (BCF) showed its maximum value (15.5) in Excoecaria agallocha for Cd, suggesting that it can be considered as a high-efficient plant for heavy metal bioaccumulation. Among all metals, Cd and Zn were highly bioaccumulated in E. agallocha (2.97 and 52.2 μg g ?1 respectively. Our findings suggest that the species may be classified as efficient metal trap for Cd in aerial parts, as indicated by higher metal accumulation in the leaves combined with BCF and translocation factor (TF) values. 相似文献
167.
168.
Qian Shu Nicholas J. Lennemann Saumendra N. Sarkar Yoel Sadovsky Carolyn B. Coyne 《PLoS pathogens》2015,11(9)
Interferon stimulated genes (ISGs) target viruses at various stages of their infectious life cycles, including at the earliest stage of viral entry. Here we identify ArfGAP with dual pleckstrin homology (PH) domains 2 (ADAP2) as a gene upregulated by type I IFN treatment in a STAT1-dependent manner. ADAP2 functions as a GTPase-activating protein (GAP) for Arf6 and binds to phosphatidylinositol 3,4,5-trisphosphate (PI(3,4,5)P3) and PI(3,4)P2. We show that overexpression of ADAP2 suppresses dengue virus (DENV) and vesicular stomatitis virus (VSV) infection in an Arf6 GAP activity-dependent manner, while exerting no effect on coxsackievirus B (CVB) or Sendai virus (SeV) replication. We further show that ADAP2 expression induces macropinocytosis and that ADAP2 strongly associates with actin-enriched membrane ruffles and with Rab8a- and LAMP1-, but not EEA1- or Rab7-, positive vesicles. Utilizing two techniques—light-sensitive neutral red (NR)-containing DENV and fluorescence assays for virus internalization—we show that ADAP2 primarily restricts DENV infection at the stage of virion entry and/or intracellular trafficking and that incoming DENV and VSV particles associate with ADAP2 during their entry. Taken together, this study identifies ADAP2 as an ISG that exerts antiviral effects against RNA viruses by altering Arf6-mediated trafficking to disrupt viral entry. 相似文献
169.
Naresh Sahebrao Nagpure Iliyas Rashid Ajey Kumar Pathak Mahender Singh Rameshwar Pati Shri Prakash Singh Uttam Kumar Sarkar 《PloS one》2015,10(8)
Mitochondrial genome sequences have been widely used for evolutionary and phylogenetic studies. Among vertebrates, fish are an important, diverse group, and their mitogenome sequences are growing rapidly in public repositories. To facilitate mitochondrial genome analysis and to explore the valuable genetic information, we developed the Fish Mitogenome Resource (FMiR) database to provide a workbench for mitogenome annotation, species identification and microsatellite marker mining. The microsatellites are also known as simple sequence repeats (SSRs) and used as molecular markers in studies on population genetics, gene duplication and marker assisted selection. Here, easy-to-use tools have been implemented for mining SSRs and for designing primers to identify species/habitat specific markers. In addition, FMiR can analyze complete or partial mitochondrial genome sequence to identify species and to deduce relational distances among sequences across species. The database presently contains curated mitochondrial genomes from 1302 fish species belonging to 297 families and 47 orders reported from saltwater and freshwater ecosystems. In addition, the database covers information on fish species such as conservation status, ecosystem, family, distribution and occurrence downloaded from the FishBase and IUCN Red List databases. Those fish information have been used to browse mitogenome information for the species belonging to a particular category. The database is scalable in terms of content and inclusion of other analytical modules. The FMiR is running under Linux operating platform on high performance server accessible at URL http://mail.nbfgr.res.in/fmir. 相似文献
170.
Dan Yu George Makkar Tuo Dong Dudley K. Strickland Rajabrata Sarkar Thomas Stacey Monahan 《PloS one》2015,10(11)