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181.
Effect of resistant starch from corn or rice on glucose control,colonic events,and blood lipid concentrations in streptozotocin-induced diabetic rats 总被引:11,自引:0,他引:11
To examine the effect of two types of resistant starch on blood glucose and insulin levels, colonic events, hypolipidemic actions and humoral immune responses, Sprague-Dawley streptozotocin-induced diabetic rats were fed diet containing resistant starch from corn or rice. The marked body weight loss by inducing diabetes was not recovered by feeding resistant starch, even though there are no differences in food intakes compared to the non-diabetic control rats. No significant effect of resistant starch feeding on blood glucose and insulin was found. Even though the length of small intestines, and cecum, colon and rectum together with the tissue weight of cecum were not affected by feeding resistant starch, the intestinal transit time was markedly shortened by both types of resistant starch and resistant starch from corn had a more pronounced effect. The short chain fatty acids in the intestinal contents did not appear to be different among the groups. Nonetheless, both of resistant starch from corn and rice significantly lowered plasma total lipid and cholesterol concentrations compared to the diabetic control. The total liver cholesterol lowering effect was observed with resistant starch from rice. Neither immunoglobulin G nor C(3) were influenced by resistant starch. 相似文献
182.
The present study was undertaken to examine the role of reactive oxygen species (ROS) and glutathione (GSH) in glia cells using human glioma cell line A172 cells. HgCl2 caused the loss of cell viability in a dose-dependent manner. HgCl2-induced loss of cell viability was not affected by H2O2 scavengers catalase and pyruvate, a superoxide scavenger superoxide dismutase, a peroxynitrite scavenger uric acid, and an inhibitor of nitric oxide NG-nitro-arginine Methyl ester. HgCl2 did not cause changes in DCF fluorescence, an H2O2-sensitive fluorescent dye. The loss of cell viability was significantly prevented by the hydroxyl radical scavengers dimethylthiourea and thiourea, but it was not affected by antioxidants DPPD and Trlox. HgCl2-induced loss of cell viability was accompanied by a significant reduction in GSH content. The GSH depletion was almost completely prevented by thiols dithiothreitol and GSH, whereas the loss of viability was partially prevented by these agents. Incubation of cells with 0.2 mM buthionine sulfoximine for 24 hr, a selective inhibitor of -glutamylcysteine synthetase, resulted in 56% reduction in GSH content without any change in cell viability. HgCl2 resulted in 34% reduction in GSH content, which was accompanied by 59% loss of cell viability. These results suggest that HgCl2-induced cell death is not associated with generation of H2O2 and ROS-induced lipid peroxidation. In addition, these data suggest that the depletion of endogenous GSH itself may not play a critical role in the HgCl2-induced cytotoxicity in human glioma cells. 相似文献
183.
Human neutrophil elastase (HNE, EC 3. 4. 21. 37) is a causative factor of inflammatory diseases, including emphysema and rheumatoid arthritis. Enzymatic characterization is important for the development of new drugs involved in the regulation of this enzyme. In this study, we investigated the enzymatic and biochemical properties of five different elastolytic enzymes, with a molecular mass between 24 kDa and 72 kDa. Three elastases, molecular masses of 27, 29, 31 kDa, might be elastase isozymes that have the same NH2-terminal amino acid sequences of Ile-Val-Gly-Gly-Arg-Arg-Ala. The 24-kDa enzyme, which showed the identical NH2-terminal amino acid sequences to elastase, was a degraded fragment of native elastase. The elastolytic activity was conserved at the 6/7 domain of the NH2-terminal region. The inhibitory characteristics of PMSF, DipF were the same as those of native elastases. The 72-kDa molecule, which showed elastolytic activity, might be a trimer formed between native elastases (31 kDa and 29 kDa) and a cathepsin G-like enzyme, which did not show elastolytic activity but enhanced the elastolytic activity of neutrophil elastase. Although this cathepsin G-like enzyme showed weak cathepsin G activity, it has distinguishable NH2-terminal sequences of Ile-Val-Gly-Gly-Ser-Arg-Ala- from those of elastase or cathepsin G. The potentiation of elastolytic activity could be a result of the trimerization of native elastase with a cathepsin G-like enzyme, and was then weakly inhibited by serine protease inhibitors, such as PMSF, DipF. Therefore, we suggest the cathepsin G-like enzyme to be a novel enzyme, which has an important role in the development of inflammation. 相似文献
184.
185.
Corneal endothelial cells (CE cells) inhibit antigen- and mitogen-activated lymphocyte proliferation assays, although interleukin 2 receptor (IL-2R) expression and responsiveness to exogenous IL-2 are unaffected. To examine this activity further, co-cultures of CE cells and T cell clones were studied. CE cells inhibited IL-2 and IL-4 production by T cells stimulated with Ag and APC, but not IL-5 or IL-6 production. CE cells also inhibited NFAT-driven lacZ reporter gene production following Ag stimulation of transfected KZO T hybridoma cells. Conversely, stimulation of IL-2 production by ionomycin, with or without PMA, was unaffected by the CE cells. Preincubation of KZO hybridoma or Jurkat cells with CE cells, or CE cell-conditioned culture supernatant, inhibited the intracellular calcium ([Ca(2+)](i)) increase induced by TCR ligation, but not the [Ca(2+)](i)increase induced by ionomycin or thapsigargin. The inhibitory effect was independent of APC and did not act by blocking costimulation, since IL-2 production stimulated by immobilized anti-CD3 alone was also inhibited by CE cells. The supernatant factor was heat labile. This novel activity is unlike other immunoregulatory molecules, including transforming growth factor beta (TGF-beta) and may contribute to local immune privilege. 相似文献
186.
Light-induced dynamic changes of NADPH fluorescence in Synechocystis PCC 6803 and its ndhB-defective mutant M55 总被引:1,自引:0,他引:1
Blue-green fluorescence emission of intact cells of Synechocystis PCC6803 and of its ndhB-defective mutant M55 was measured with a standard pulse-amplitude-modulation chlorophyll fluorometer equipped with a new type of emitter-detector unit featuring pulse-modulated UV-A measuring light and a photomultiplier detector. A special illumination program of repetitive saturating light pulses with intermittent dark periods (10 s light, 40 s dark) was applied to elicit dynamic fluorescence changes under conditions of quasi-stationary illumination. The observed effects of artificial electron acceptors and inhibitors on the responses of wild-type and mutant M55 cells lead to the conclusion that changes of NAD(P)H fluorescence are measured. In control samples, a rapid phase of light-driven NADP reduction is overlapped by a somewhat slower phase of NADPH oxidation which is suppressed by iodoacetic acid and, hence, appears to reflect NADPH oxidation by the Calvin cycle. Mercury chloride transforms the light-driven positive response into a negative one, suggesting that inhibition of NADP reduction at the acceptor side of PSI leads to reduction of molecular oxygen, with the hydrogen peroxide formed (via superoxide) causing rapid oxidation of NADPH. The new fluorescence approach opens the way for new insights into the complex interactions between photosynthetic and respiratory pathways in cyanobacteria. 相似文献
187.
Qiao-Ning Liu Rui-Sang Liu Yi-Hua Wang Zhi-Yuan Mi Dong-Sheng Li Jian-Jiang Zhong Ya-Jie Tang 《Bioresource technology》2009,100(14):3644-3649
For the first time, a fed-batch fermentation process of Tuber melanosporum was developed for the efficient production of bioactive mycelia and Tuber polysaccharides. Each 1.67 g/L of peptone and 8.33 g/L of yeast extract were added on day 3, 6, and 9, respectively, and sucrose was fed to maintain its concentration around 35–5 g/L when its residual level decreased to 10–5 g/L. Then, the maximal biomass, the production of extracellular polysaccharides (EPS) and intracellular polysaccharides (IPS) reached 53.72 ± 2.57 g DW/L, 7.09 ± 0.62 and 4.43 ± 0.21 g/L, respectively. Compared with the batch culture conducted in the enriched medium, the biomass, the production of EPS and IPS were enhanced by 55.8%, 222.3% and 103.2%, respectively. Not only the cell density but also the production of EPS and IPS were the highest ever reported in truffle fermentation, and the biomass was also the highest as ever reported in mushroom fermentation. 相似文献
188.
Jian Zhang Sha Li Lu Li Meng Li Chongye Guo Jun Yao Shuangli Mi 《基因组蛋白质组与生物信息学报(英文版)》2015,13(1):17-24
Exosomes are 40–100 nm nano-sized vesicles that are released from many cell types into the extracellular space. Such vesicles are widely distributed in various body fluids. Recently,m RNAs and micro RNAs(mi RNAs) have been identified in exosomes, which can be taken up by neighboring or distant cells and subsequently modulate recipient cells. This suggests an active sorting mechanism of exosomal mi RNAs, since the mi RNA profiles of exosomes may differ from those of the parent cells. Exosomal mi RNAs play an important role in disease progression, and can stimulate angiogenesis and facilitate metastasis in cancers. In this review, we will introduce the origin and the trafficking of exosomes between cells, display current research on the sorting mechanism of exosomal mi RNAs, and briefly describe how exosomes and their mi RNAs function in recipient cells.Finally, we will discuss the potential applications of these mi RNA-containing vesicles in clinical settings. 相似文献
189.
目的:观察创伤后应激障碍(PTSD)对慢性不可预见性应激(CUS)抑郁模型的影响。方法:采用足底电击的方法建立大鼠创伤后应激障碍模型。成年雄性S-D大鼠40只随机分为四组(n=10):对照组(C组)、PTSD组、CUS组、PTSD+CUS组(P+C组)。在1、7、14、21天测量大鼠体重,并行糖水偏好和强迫游泳实验,在7、14、21天做条件性恐惧实验。结果:与C组相比,CUS组和P+C组体重增加缓慢,PTSD组体重正常。CUS组于第21天出现糖水消耗比例降低,强迫游泳不动时间增加。P+C组于第14天即出现上述抑郁表现。条件性恐惧实验中,PTSD组与PTSD+CUS组僵直时间显著增加,CUS组无明显变化。结论:创伤后应激障碍的动物更易产生抑郁表现。 相似文献
190.
Zhong-Jia Ding Xin Chen Xiao-Xu Tang Xi Wang Yong-Li Song Xiao-Dong Chen Wen-Juan Mi Jian Wang Ying Lin Fu-Quan Chen Jian-Hua Qiu 《PloS one》2015,10(4)