全文获取类型
收费全文 | 355篇 |
免费 | 44篇 |
出版年
2020年 | 3篇 |
2019年 | 4篇 |
2018年 | 4篇 |
2017年 | 5篇 |
2016年 | 5篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 14篇 |
2011年 | 13篇 |
2010年 | 13篇 |
2009年 | 9篇 |
2008年 | 15篇 |
2007年 | 19篇 |
2006年 | 9篇 |
2005年 | 12篇 |
2004年 | 12篇 |
2003年 | 14篇 |
2002年 | 10篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 10篇 |
1998年 | 8篇 |
1997年 | 8篇 |
1996年 | 5篇 |
1995年 | 7篇 |
1994年 | 6篇 |
1993年 | 7篇 |
1992年 | 12篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 9篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 5篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 4篇 |
1980年 | 6篇 |
1979年 | 7篇 |
1978年 | 6篇 |
1977年 | 6篇 |
1976年 | 3篇 |
1962年 | 2篇 |
1959年 | 2篇 |
1945年 | 2篇 |
1944年 | 2篇 |
1887年 | 4篇 |
排序方式: 共有399条查询结果,搜索用时 46 毫秒
171.
Vibeke Secher Dam Donna MB Boedtkjer Christian Aalkjaer Vladimir Matchkov 《Channels (Austin, Tex.)》2014,8(4):361-369
The presence of Ca2+-activated Cl– currents (ICl(Ca)) in vascular smooth muscle cells (VSMCs) is well established. ICl(Ca) are supposedly important for arterial contraction by linking changes in [Ca2+]i and membrane depolarization. Bestrophins and some members of the TMEM16 protein family were recently associated with ICl(Ca). Two distinct ICl(Ca) are characterized in VSMCs; the cGMP-dependent ICl(Ca) dependent upon bestrophin expression and the ‘classical’ Ca2+-activated Cl– current, which is bestrophin-independent. Interestingly, TMEM16A is essential for both the cGMP-dependent and the classical ICl(Ca). Furthermore, TMEM16A has a role in arterial contraction while bestrophins do not. TMEM16A’s role in the contractile response cannot be explained however only by a simple suppression of the depolarization by Cl– channels. It is suggested that TMEM16A expression modulates voltage-gated Ca2+ influx in a voltage-independent manner and recent studies also demonstrate a complex role of TMEM16A in modulating other membrane proteins. 相似文献
172.
Samson Mani Katarzyna Szymańska Cyrille Cuenin David Zaridze Karen Balassiano Sheila CS Lima Elena Matos Alexander Daudt Sergio Koifman Victor Wunsch Filho Ana MB Menezes Maria Paula Curado Gilles Ferro Thomas Vaissière Bakary S Sylla Massimo Tommasino Luis Felipe Ribeiro Pinto Paolo Boffetta Pierre Hainaut Paul Brennan Zdenko Herceg 《Epigenetics》2012,7(3):270-277
Cancers of the upper aerodigestive tract (UADT) are common forms of malignancy associated with tobacco and alcohol exposures, although human papillomavirus and nutritional deficiency are also important risk factors. While somatically acquired DNA methylation changes have been associated with UADT cancers, what triggers these events and precise epigenetic targets are poorly understood. In this study, we applied quantitative profiling of DNA methylation states in a panel of cancer-associated genes to a case-control study of UADT cancers. Our analyses revealed a high frequency of aberrant hypermethylation of several genes, including MYOD1, CHRNA3 and MTHFR in UADT tumors, whereas CDKN2A was moderately hypermethylated. Among differentially methylated genes, we identified a new gene (the nicotinic acetycholine receptor gene) as target of aberrant hypermethylation in UADT cancers, suggesting that epigenetic deregulation of nicotinic acetycholine receptors in non-neuronal tissues may promote the development of UADT cancers. Importantly, we found that sex and age is strongly associated with the methylation states, whereas tobacco smoking and alcohol intake may also influence the methylation levels in specific genes. This study identifies aberrant DNA methylation patterns in UADT cancers and suggests a potential mechanism by which environmental factors may deregulate key cellular genes involved in tumor suppression and contribute to UADT cancers.Key words: DNA methylation, upper aerodigestive tract, cancer, risk factors, biomarkers 相似文献
173.
The development expression of alpha-, mu- and pi-class glutathione S-transferases in human liver 总被引:1,自引:0,他引:1
R C Strange A F Howie R Hume B Matharoo J Bell C Hiley P Jones G J Beckett 《Biochimica et biophysica acta》1989,993(2-3):186-190
The developmental expression of the alpha, mu and pi class glutathione S-transferases has been defined in human liver using radioimmunoassay and immunohistochemistry. Expression of alpha and mu class isoenzymes increased significantly at birth, while that of the pi isoenzyme declined during the first trimester. Mu-class isoenzymes (GST1 1, GST1 2, GST1 2-1) were expressed in hepatocytes but not in other liver cell types. 相似文献
174.
175.
176.
The human glutathione S-transferases. Immunohistochemical studies of the developmental expression of Alpha- and Pi-class isoenzymes in liver. 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《The Biochemical journal》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Immunohistochemical studies of the developmental expression of the Alpha- and Pi-class glutathione S-transferases in human liver have shown that the Pi enzyme is expressed in bile-duct epithelium and some hepatocytes but not in haematopoietic cells. This locus is down-regulated during gestation in hepatocytes but not in epithelium. The enzymes of the Alpha set were also found in only some hepatocytes, and it appears that many cells express neither these nor the Pi forms. 相似文献
177.
178.
179.
Studies on the developmental expression of glutathione S-transferase isoenzymes in human heart and diaphragm 总被引:2,自引:0,他引:2
P A Hirrell R Hume A A Fryer M F Collins R Drew A R Bradwell R C Strange 《Biochimica et biophysica acta》1987,915(3):371-377
The developmental expression of the basic, near-neutral and acidic isoenzymes of glutathione S-transferase (RX:glutathione R-transferase, EC 2.5.1.18) has been studied in heart and diaphragm. Neither these enzymes nor the putative muscle-specific GST4 isoenzyme demonstrated any developmental trends in expression. In vitro hybridisation and SDS-discontinuous polyacrylamide gel electrophoresis were used to show that the GST4 isoenzyme is a homodimer composed of monomers that have a slightly larger molecular weight than the near-neutral isoenzyme. The sensitivity of GST4 to inhibitors also appeared similar to that of the GST1 2 isoenzyme. Immunodiffusion and immunoblotting techniques were used to show that the acidic enzyme in muscle is immunologically identical to that in other tissues. 相似文献
180.