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211.
212.
Hui Zhu Yugui Cui Jin Xie Ling Chen Xiangxiang Chen Xuejiang Guo Yefei Zhu Xinghai Wang Jiansun Tong Zuomin Zhou Yue Jia Yan‐he Lue Amiya Sinha Hikim Christina Wang Ronald S. Swerdloff Jiahao Sha 《Proteomics》2010,10(19):3480-3493
Mild testicular heating safely and reversibly suppresses spermatogenesis. In this study, we attempted to clarify the underlying molecular mechanism(s) involved in heat‐induced spermatogenesis suppression in human testis. We conducted global proteomic analyses of human testicular biopsies before, and at 2 and 9 wk after heat treatment. Thirty‐one and Twenty‐six known proteins were identified with significant differential expression at 2 and 9 wk after heat treatment, respectively. These were used to characterize the cellular and molecular events in the testes when seminiferous epithelia became damaged (2 wk) and recovered (9 wk). At 2 wk post‐treatment, the changed expression of a series of proteins could promote apoptosis or suppress proliferation and cell survival. At 9 wk post‐treatment, the changed expression of proteins mainly promoted cell proliferation, differentiation and survival, but resisted cell apoptosis. Among those heat‐regulated proteins, HNRNPH1 was selected for the further functional study. We found that HNRNPH1 was an anti‐apoptosis protein that could regulate the expression of other heat‐induced proteins. In conclusion, heat‐induced reversible suppression of spermatogenesis occurred by modulating the expression of proteins related to proliferation, differentiation, apoptosis and cell survival pathways. These differentially expressed proteins were found to be key molecular targets affecting spermatogenesis after heat treatment. 相似文献
213.
214.
Chunbin Zou Yan Chen Rebecca M. Smith Courtney Snavely Jin Li Tiffany A. Coon Bill B. Chen Yutong Zhao Rama K. Mallampalli 《The Journal of biological chemistry》2013,288(9):6306-6316
Histone acetyltransferase binding to origin recognition complex (HBO1) plays a crucial role in DNA replication licensing and cell proliferation, yet its molecular regulation in cells is relatively unknown. Here an uncharacterized protein, Fbxw15, directly interacts with HBO1, a labile protein (t½ = ∼3 h), to mediate its ubiquitination (Lys338) and degradation in the cytoplasm. Fbxw15-mediated HBO1 depletion required mitogen-activated protein kinase 1 (Mek1), which was sufficient to trigger HBO1 phosphorylation and degradation in cells. Mek1 ability to produce HBO1 degradation was blocked by Fbxw15 silencing. Lipopolysaccharide induced HBO1 degradation, an effect abrogated by Fbxw15 or Mek1 cellular depletion. Modulation of Fbxw15 levels was able to differentially regulate histone H3K14 acetylation and cellular proliferation by altering HBO1 levels. These studies authenticate Fbxw15 as a ubiquitin E3 ligase subunit that mediates endotoxin-induced HBO1 depletion in cells, thereby controlling cell replicative capacity. 相似文献
215.
SIRT1 expression is refractory to hypoxia and inflammatory cytokines in nucleus pulposus cells: Novel regulation by HIF‐1α and NF‐κB signaling 下载免费PDF全文
216.
Quercetin and other flavonoids have been reported to exhibit both antioxidant and pro‐oxidant properties. Most studies about the pro‐oxidative ability were conducted in the presence of metal ions, and the essential functional moiety of quercetin responsible for the pro‐oxidative effect is still unclear. In this study, we evaluated the pro‐oxidative abilities in the absence of metal ions of two quercetin derivatives, i.e., quercetin‐3′‐O‐β‐D ‐glucoside ( 1 ) and quercetin‐3‐O‐β‐D ‐glucoside ( 2 ), by assessing DNA cleavage and HO.‐radical production. The binding mode between these compounds and DNA was studied by fluorescence and viscometric titrations. The results showed that 1 can efficiently induce oxidative damage to plasmid DNA, while 2 shows poor activity. Both 1 and 2 bind to DNA via groove‐binding. These results proved that the α‐hydroxy‐β‐oxo‐α,β‐enone moiety contributes to the pro‐oxidative activity of quercetin. 相似文献
217.
目的 探讨结核杆菌感染与恶性肿瘤的关系。方法 采用多聚酶链反应(PCR) 技术检测两种恶性肿瘤组织中结核杆菌DNA(TB- DNA) 。结果41 例恶性肿瘤组织中检出TB- DNA 阳性患者8 例,占19.5 % ,且TB-DNA 阳性患者肿瘤发病部位基本与结核病的好发部位一致。结论 结核杆菌感染可能与一些恶性肿瘤存在特殊相关性。 相似文献
218.
Flaviviral NS2B is a required cofactor for NS3 serine protease activity and plays an important role in promoting functional NS2B-NS3 protease configuration and maintaining critical interactions with protease catalysis substrates. The residues D80DDG in West Nile virus (WNV) NS2B are important for protease activity. To investigate the effects of D80DDG in NS2B on protease activity and viral replication, the negatively charged region D80DD and the conserved residue G83 of NS2B were mutated (D80DD/E80EE, D80DD/K80KK, D80DD/A80AA, G83F, G83S, G83D, G83K, and G83A), and NS3 D75A was designated as the negative control. The effects of the mutations on NS2B-NS3 activity, viral translation, and viral RNA replication were analyzed using kinetic analysis of site-directed enzymes and a transient replicon assay. All substitutions resulted in significantly decreased enzyme activity and blocked RNA replication. The negative charge of D80DD is not important for maintaining NS2B function, but side chain changes in G83 have dramatic effects on protease activity and RNA replication. These results demonstrate that NS2B is important for viral replication and that D80DD and G83 substitutions prevent replication; they will be useful for understanding the relationship between NS2B and NS3. 相似文献
219.
Sun Y Li T Chen H Zhang K Zheng K Mu Y Yan G Li W Shen J Luo G 《The Journal of biological chemistry》2004,279(36):37235-37240
Glutathione peroxidase (GPX) is one of the most crucial antioxidant enzymes in a variety of organisms. Here we described a new strategy for generating a novel GPX mimic by combination of a phage-displayed random 15-mer peptide library followed by computer-aided rational design and chemical mutation. The novel GPX mimic is a homodimer consisting of a 15-mer selenopeptide with an appropriate catalytic center, a specific binding site for substrates, and high catalytic efficiency. Its steady state kinetics was also studied, and the values of k(cat)/K(m)(GSH) and k(cat)/ K(mH(2)O(2)) were found to be similar to that of native GPX and the highest among the existing GPX mimics. Moreover, the novel GPX mimic was confirmed to have a strong antioxidant ability to inhibit lipid peroxidation by measuring the content of malondialdehyde, cell viability, and lactate dehydrogenase activity. Importantly, the novel GPX mimic can penetrate into the cell membrane because of its small molecular size. These characteristics endue the novel mimic with potential perspective for pharmaceutical applications. 相似文献
220.
Effects of Irrigation and Nitrogen on the Performance of Aerobic Rice in Northern China 总被引:1,自引:0,他引:1
Chang-Ying Xue Xiao-Guang Yang B.A.M. Bouman Wei Deng Qiu-Ping Zhang Jie Yang Wei-Xiong Yan Tian-Yi Zhang A-Ji Rouzi Hua-Qi Wang Pu Wang 《植物学报(英文版)》2008,50(12):1589-1600
Aerobic rice is a new production system in which specially-developed varieties are grown under non-flooded, non-puddled, and non-saturated soil conditions. In 2003-2004, irrigation x Nitrogen experiments were carried out near Beijing using variety HD297. Water treatments included four irrigation levels, and Nitrogen treatments included different fertilizer N application rates and different numbers of N splits. The highest yields were 4460 kg/ha with 688 mm of total (rain plus irrigation) water input in 2003 and 6 026 kg/ha with 705 mm of water input in 2004. Because of the quite even distribution of rainfall in both years, the four irrigation treatments did not result in large differences of soil water conditions. There were few significant effects of irrigation on biomass accumulation, but yield increased with the total amount of water applied. High yields coincided with high harvest index and high percentages of grain filling. The application of fertilizer N either reduced biomass and yield or kept it at the same level as 0 N and consistently reduced the percentage grain filling and 1 000-grain weight. With the highest water application, five splits of N gave higher yield than three splits, whereas three splits gave higher yield than five splits with lower water applications. 相似文献