全文获取类型
收费全文 | 1884篇 |
免费 | 143篇 |
国内免费 | 119篇 |
出版年
2023年 | 14篇 |
2022年 | 63篇 |
2021年 | 81篇 |
2020年 | 48篇 |
2019年 | 82篇 |
2018年 | 82篇 |
2017年 | 67篇 |
2016年 | 72篇 |
2015年 | 94篇 |
2014年 | 116篇 |
2013年 | 120篇 |
2012年 | 171篇 |
2011年 | 139篇 |
2010年 | 107篇 |
2009年 | 78篇 |
2008年 | 88篇 |
2007年 | 73篇 |
2006年 | 80篇 |
2005年 | 56篇 |
2004年 | 45篇 |
2003年 | 53篇 |
2002年 | 51篇 |
2001年 | 38篇 |
2000年 | 37篇 |
1999年 | 36篇 |
1998年 | 14篇 |
1997年 | 24篇 |
1996年 | 14篇 |
1995年 | 18篇 |
1994年 | 14篇 |
1993年 | 14篇 |
1992年 | 19篇 |
1991年 | 28篇 |
1990年 | 12篇 |
1989年 | 13篇 |
1988年 | 5篇 |
1987年 | 14篇 |
1986年 | 6篇 |
1985年 | 6篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 3篇 |
1980年 | 4篇 |
1979年 | 3篇 |
1978年 | 3篇 |
1975年 | 3篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1971年 | 4篇 |
1967年 | 3篇 |
排序方式: 共有2146条查询结果,搜索用时 31 毫秒
1.
Plant and Soil - Agricultural practices often have persistent effects on soil physicochemical properties and soil biota, which can feedback to influence plant performance. We investigated... 相似文献
2.
Wei Liu Yaoting Sun Weigang Ge Fangfei Zhang Lin Gan Yi Zhu Tiannan Guo Kexin Liu 《Molecular & cellular proteomics : MCP》2022,21(2):100187
Drug resistance is a critical obstacle to effective treatment in patients with chronic myeloid leukemia. To understand the underlying resistance mechanisms in response to imatinib mesylate (IMA) and adriamycin (ADR), the parental K562 cells were treated with low doses of IMA or ADR for 2 months to generate derivative cells with mild, intermediate, and severe resistance to the drugs as defined by their increasing resistance index. PulseDIA-based (DIA [data-independent acquisition]) quantitative proteomics was then employed to reveal the proteome changes in these resistant cells. In total, 7082 proteins from 98,232 peptides were identified and quantified from the dataset using four DIA software tools including OpenSWATH, Spectronaut, DIA-NN, and EncyclopeDIA. Sirtuin signaling pathway was found to be significantly enriched in both ADR-resistant and IMA-resistant K562 cells. In particular, isocitrate dehydrogenase (NADP(+)) 2 was identified as a potential drug target correlated with the drug resistance phenotype, and its inhibition by the antagonist AGI-6780 reversed the acquired resistance in K562 cells to either ADR or IMA. Together, our study has implicated isocitrate dehydrogenase (NADP(+)) 2 as a potential target that can be therapeutically leveraged to alleviate the drug resistance in K562 cells when treated with IMA and ADR. 相似文献
3.
Aurin tricarboxylic acid, the anti-AIDS compound, prevents the binding of interferon-alpha to its receptor 总被引:2,自引:0,他引:2
Y X Gan J L Weaver P S Pine K C Zoon A Aszalos 《Biochemical and biophysical research communications》1990,172(3):1298-1303
Binding of HIV to its receptor, the CD4 molecule of lymphocytes, can be prevented by chemical agents. These agents could be considered as potential anti-AIDS drugs. We have shown that aurin tricarboxylic acid (ATA, 3 microM) specifically blocks the binding of gp120, the HIV coat protein, to the CD4 molecule. We have also found that ATA prevents the binding of interferon-alpha to its receptor in a dose-dependent manner (12-50 microM range). Membrane potential shift, associated with binding of interferon-alpha to its receptor, was also blocked by ATA in a dose-dependent fashion. Our results indicate that potential anti-AIDS drugs should be screened for such undesired side effects. 相似文献
4.
Abdulrazak Osama Han Ming Gan Cindy Shuan Ju Teh Kien-Pong Yap Kwai-Lin Thong 《Journal of bacteriology》2012,194(24):6933
The genome sequence analysis of a clinical Vibrio cholerae VC35 strain from an outbreak case in Malaysia indicates multiple genes involved in host adaptation and a novel Na+-driven multidrug efflux pump-coding gene in the genome of Vibrio cholerae with the highest similarity to VMA_001754 of Vibrio mimicus VMA223. 相似文献
5.
Experiments have shown that the block of proventriculus develops in 1.1 to 1.5% of individuals of the flea Neopsylla abagaitui infected with plague microbe. These insects transmit the agent during bloodsucking to different plague carriers (Citellus dauricus, C. undulatus, Meriones unguiculatus, Microtus gregalis). The plague microbe is preserved in fleas for 65 days (the observation period). 相似文献
6.
MacELISA、RPHI和IFAT用于流行性出血热早期诊断的比较 总被引:2,自引:0,他引:2
比较了IgM捕获ELISA(MacELISA)、反向间接血凝抑制试验(RPHI)和间接免疫荧光抗体试验(IFAT)检测流行性出血热(EHF)病人血清特异性抗体的结果。MacELISA对急性期血清IgM抗体的阳性检出率与RPHI对总抗体的阳性检出率相近,两法都具有较高的敏感性。而IFAT检测IgG抗体的阳性率则较低。总抗体滴度(RPHI)与IgG抗体滴度(IFAT)相关(r=0.542,P<0.01),而与IgM抗体滴度(MacELISA)无明显相关(r<0.1)。但进一步研究发现,3日内血清IgM抗体滴度与总抗体滴度(RPHI)存在相关关系(r=0.701,P<0.01),表明IgM抗体可能也与发病初期RPHI的较高的阳性检出率有关。本工作表明,MacELISA作为一种早期诊断方法具有高度的特异性和敏感性,而RPHI操作简便、快速、敏感性高,但存在一定的非特异性。研究还发现,流行区临床诊断为EHF的病人,IFAT(IgG)和RPHI检测均阳性,而MacELISA(IgM)阴性,提示用RPHI进行血清学诊断时,检查双份血清是必要的。 相似文献
7.
流行性出血热病毒R22株cDNA克隆及其特异性鉴定 总被引:3,自引:0,他引:3
用家鼠型流行性出血热病毒R22株RNA,经polyA接尾,以Oligo-dT做引物,合成cDNA。用pUC18为载体转染E.coli Mc1061,建立cDNA克隆。再经菌落杂交,选择病毒特异性的5个阳性克隆制成缺口翻译探针,与病毒RNA3个片段进行反杂交,确定RNA片段的特异性。结果表明,3个克隆为中(M)片段的cDNA,另两个分别为大(L)和小(S)片段cDNA。核苷酸序列分析证明,克隆的DNA中含病毒特异的核苷酸序列。 相似文献
8.
红腹锦鸡和白腹锦鸡卵壳的超微结构 总被引:18,自引:2,他引:16
本文报道了锦鸡属——白腹锦鸡和红腹锦鸡卵壳的气孔、外壳膜、锥体层、木栅层的超微结构。并对两者的卵壳进行了比较。 相似文献
9.
用~(14)C-Pro和~3H_2-Tyr离体暗培养黄瓜子叶,发现细胞质、SECW和RCW中的Hyp/Pro和Idt/Tyr都随时间呈线性增加。这两种比值后两者高于前者,而两种比值增加速度之比在胞质部分最大、RCW中最小。表明在胞质和胞壁中都有Pro羟化和Tyr异联化过程,但羟化作用主要发生在胞质中,异联化主要在RCW中。 理化处理(高渗溶液和CHM)和放射性示踪证明胞质中存在HRGP库;它被分泌到胞壁后,先以离子键与壁结合,后转变为共价键与壁结合的伸展素。 相似文献
10.
Cells-precursors of haemopoietic microenvironment, as well as osteogenic cells-precursors, indicated with heterotopic transplantation of mouse bone marrow, can repair sublethal radiation damages. Thymectomy of the bone-marrow donors does not influence this capacity of the stromal precursors. 相似文献