全文获取类型
收费全文 | 2905篇 |
免费 | 154篇 |
专业分类
3059篇 |
出版年
2023年 | 9篇 |
2022年 | 17篇 |
2021年 | 39篇 |
2020年 | 17篇 |
2019年 | 30篇 |
2018年 | 49篇 |
2017年 | 26篇 |
2016年 | 55篇 |
2015年 | 86篇 |
2014年 | 107篇 |
2013年 | 186篇 |
2012年 | 231篇 |
2011年 | 212篇 |
2010年 | 129篇 |
2009年 | 111篇 |
2008年 | 202篇 |
2007年 | 207篇 |
2006年 | 185篇 |
2005年 | 172篇 |
2004年 | 203篇 |
2003年 | 169篇 |
2002年 | 197篇 |
2001年 | 20篇 |
2000年 | 23篇 |
1999年 | 26篇 |
1998年 | 31篇 |
1997年 | 33篇 |
1996年 | 39篇 |
1995年 | 30篇 |
1994年 | 31篇 |
1993年 | 25篇 |
1992年 | 17篇 |
1991年 | 21篇 |
1990年 | 13篇 |
1989年 | 13篇 |
1988年 | 12篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 4篇 |
1984年 | 3篇 |
1983年 | 10篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 10篇 |
1979年 | 6篇 |
1976年 | 2篇 |
1975年 | 2篇 |
1974年 | 4篇 |
1970年 | 2篇 |
1969年 | 2篇 |
排序方式: 共有3059条查询结果,搜索用时 9 毫秒
141.
142.
The involvement of protein phosphatases in the activation of superoxide (O2-)- generating enzyme in human neutrophils was examined using calyculin A, an inhibitor of protein phosphatase type 1 and 2A. Calyculin A inhibited the phorbol myristate acetate (PMA)- and opsonized zymosan (OZ)-activated O2- generation by human neutrophils. This inhibitory effect of calyculin A on PMA-activated O2- generation was reversed by the addition of KT5926, a specific inhibitor of myosin light chain kinase and Ca2+/calmodulin-dependent protein kinase II. These results suggest that the addition of calyculin A may cause hyperphosphorylation of some protein(s) that plays a crucial role in the PMA-dependent activation of O2- generating enzyme, and that this protein hyperphosphorylation may be evoked by a KT5926-sensitive kinase or its downstream kinase. Whereas two-dimensional analysis involving 32P revealed that calyculin A caused the hyperphosphorylation of many proteins, KT5926 mainly reduced the calyculin A-induced hyperphosphorylation of a 67 kDa protein in activated neutrophils, suggesting that the hyperphosphorylation of the 67 kDa protein might inhibit the PMA-dependent activation of NADPH oxidase. The 67 kDa cytosolic protein was moderately phosphorylated on the addition of PMA. On the other hand, in the absence of calyculin A, KT5926 inhibited both PMA-induced O2- generation and phosphorylation of the 67 kDa protein. Amino acid sequence analysis of peptides derived from the 67 kDa protein revealed that the 67 kDa protein was identical to L-plastin, an actin-bundling protein. We conclude that optimally phosphorylated L-plastin may play some crucial role in the activation of NADPH oxidase. 相似文献
143.
Bach1 functions as a hypoxia-inducible repressor for the heme oxygenase-1 gene in human cells 总被引:4,自引:0,他引:4
144.
Thermophilic aerobic composting is a widely practiced method for the disposal of exhaust materials. We isolated a thermophilic bacteria strain from a compost sample under aerobic conditions at 60 degrees C. On the basis of its 16S rRNA sequence and physiological characteristics, this strain was identified as Bacillus thermodenitrificans OHT-1. An 18-subunit oligonucleotide probe for 16S rRNA, labeled with fluorescein isothiocyanate, was developed for the detection of B. thermodenitrificans. Spores and vegetative cells of B. thermodenitrificans OHT-1 were detected in liquid culture and laboratory compost by whole cell hybridization using this oligonucleotide probe. The results obtained by whole cell hybridization were evaluated in growth experiments of B. thermodenitrificans OHT-1 in laboratory compost and were used to enumerate spores and vegetative cells. 相似文献
145.
Martsev SP Dubnovitsky AP Vlasov AP Hoshino M Hasegawa K Naiki H Goto Y 《Biochemistry》2002,41(10):3389-3395
The recombinant V(L) domain that represents the variable part of the light chain (type kappa) of mouse monoclonal antibody F11 directed against human spleen ferritin was found to form amyloid fibrils at acidic pH as evidenced by electron microscopy, thioflavin T binding, and apple-green birefringence after Congo red staining. This is the first demonstration of amyloid fibril formation of the mouse V(L) domain. To understand the mechanism of acidic pH-induced amyloid fibril formation, conformational changes of the V(L) domain were studied by one-dimensional NMR, differential scanning calorimetry, analytical ultracentrifugation, hydrophobic dye binding, far-UV circular dichroism, and tryptophan fluorescence. The results indicated accumulation of two intermediate states during acid unfolding, which might be responsible for amyloid fibril formation. The more structured intermediate that exhibited maximal accumulation at pH 3 retained the nativelike secondary structure and a hydrophobic core, but exposed hydrophobic surfaces that bind 8-anilino-1-naphthalenesulfonate. Below pH 2, a more disordered intermediate with dequenched tryptophan fluorescence but still retaining the beta-sheet structure accumulated. The optimal pH of amyloid fibril formation (i.e., pH 4) was close to the optimal pH of the accumulation of the nativelike intermediate, suggesting that the amyloid fibrils might be formed through this intermediate. 相似文献
146.
Noda M Yamashita S Takahashi N Eto K Shen LM Izumi K Daniel S Tsubamoto Y Nemoto T Iino M Kasai H Sharp GW Kadowaki T 《The Journal of biological chemistry》2002,277(44):41817-41826
147.
Disruption of adiponectin causes insulin resistance and neointimal formation 总被引:110,自引:0,他引:110
Kubota N Terauchi Y Yamauchi T Kubota T Moroi M Matsui J Eto K Yamashita T Kamon J Satoh H Yano W Froguel P Nagai R Kimura S Kadowaki T Noda T 《The Journal of biological chemistry》2002,277(29):25863-25866
The adipocyte-derived hormone adiponectin has been proposed to play important roles in the regulation of energy homeostasis and insulin sensitivity, and it has been reported to exhibit putative antiatherogenic properties in vitro. In this study we generated adiponectin-deficient mice to directly investigate whether adiponectin has a physiological protective role against diabetes and atherosclerosis in vivo. Heterozygous adiponectin-deficient (adipo(+/-)) mice showed mild insulin resistance, while homozygous adiponectin-deficient (adipo(-/-)) mice showed moderate insulin resistance with glucose intolerance despite body weight gain similar to that of wild-type mice. Moreover, adipo(-/-) mice showed 2-fold more neointimal formation in response to external vascular cuff injury than wild-type mice (p = 0.01). This study provides the first direct evidence that adiponectin plays a protective role against insulin resistance and atherosclerosis in vivo. 相似文献
148.
Phagocytes play a central role in the host defense system, and the relationship between the mechanism of their activation and cytoskeletal reorganization has been studied. We have previously reported a possible involvement of cofilin, an actin-binding protein, in phagocyte functions through its phosphorylation/dephosphorylation and translocation to the plasma membrane regions. In this work, we have obtained a new line of evidence showing an important role of cofilin in phagocyte functions using the mouse macrophage cell line J774.1 and an antisense oligonucleotide to cofilin. Upon stimulation with opsonized zymosan (OZ), cofilin was phosphorylated, and it accumulated around phagocytic vesicles. As the antisense oligonucleotide to cofilin, a 20-mer S-oligo corresponding to the sequence including the AUG translational initiation site was found to be effective. In the cells treated with the antisense oligonucleotide, the amount of cofilin was less than 30% of that in the control cells, and the level of F-actin was two or three times higher than that in the control cells before and throughout the cell activation. In the antisense oligonucleotide-treated cells, OZ-triggered superoxide production was three times faster than that in the control cells. Furthermore, phagocytosis of OZ was enhanced by the antisense. These results show that cofilin plays an essential role in the control of phagocyte function through regulation of actin filament dynamics. 相似文献
149.
150.