全文获取类型
收费全文 | 392篇 |
免费 | 27篇 |
专业分类
419篇 |
出版年
2023年 | 1篇 |
2022年 | 6篇 |
2021年 | 11篇 |
2020年 | 4篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 8篇 |
2016年 | 9篇 |
2015年 | 14篇 |
2014年 | 12篇 |
2013年 | 27篇 |
2012年 | 20篇 |
2011年 | 30篇 |
2010年 | 18篇 |
2009年 | 16篇 |
2008年 | 12篇 |
2007年 | 17篇 |
2006年 | 21篇 |
2005年 | 18篇 |
2004年 | 15篇 |
2003年 | 17篇 |
2002年 | 21篇 |
2001年 | 12篇 |
2000年 | 7篇 |
1999年 | 10篇 |
1998年 | 2篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1990年 | 2篇 |
1989年 | 5篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 2篇 |
1985年 | 8篇 |
1984年 | 6篇 |
1983年 | 1篇 |
1982年 | 3篇 |
1981年 | 4篇 |
1980年 | 4篇 |
1979年 | 5篇 |
1978年 | 2篇 |
1977年 | 2篇 |
1976年 | 1篇 |
1975年 | 5篇 |
1974年 | 2篇 |
1973年 | 6篇 |
1972年 | 2篇 |
排序方式: 共有419条查询结果,搜索用时 15 毫秒
21.
Maliandi MV Busi MV Clemente M Zabaleta EJ Araya A Gomez-Casati DF 《Protein expression and purification》2007,51(2):157-161
Frataxin, a nuclear-encoded mitochondrial protein, has been proposed to participate in Fe-S cluster assembly, mitochondrial energy metabolism, respiration, and iron homeostasis. However, its precise function remains elusive. Frataxin is highly conserved in living organisms with no major structural changes, in particular at the C-terminal protein domain, suggesting that it plays a key function in all organisms. Recently, a plant gene, AtFH, with significant homology to other members of the frataxin family has been described. To gain insight on the frataxin role in plants, the frataxin domain was expressed in Escherichia coli BL21-codonPlus (DE3)-RIL cells and purified using a Ni-chelating column. The purified protein, added to a mixture containing Fe(II) and H2O2, attenuates the Fenton reaction indicating that the recombinant plant frataxin is functional. The procedure described here produced high yield of 99% pure protein through only one chromatographic step, suitable for further structure-function studies. 相似文献
22.
Kanbe Y Kim MH Nishimoto M Ohtake Y Yoneya T Ohizumi I Tsunenari T Taniguchi K Kaiho S Nabuchi Y Araya H Kawata S Morikawa K Jo JC Kwon HA Lim HS Kim HY 《Bioorganic & medicinal chemistry letters》2006,16(18):4959-4964
In order to develop orally active pure antiestrogens, we incorporated the carboxy-containing side chains into the 7alpha-position of the steroid scaffold and found that 17-keto derivative CH4893237 (12b) functioned as a pure antiestrogen with its oral activity much superior to clinically used pure antiestrogen, ICI182,780. Results from the pharmacokinetic evaluation indicated that the potent antiestrogen activity at oral dosing in mice attributed to both improved absorption from the intestinal wall and metabolic stability in liver. 相似文献
23.
24.
25.
26.
Perales M Parisi G Fornasari MS Colaneri A Villarreal F González-Schain N Echave J Gómez-Casati D Braun HP Araya A Zabaleta E 《Plant molecular biology》2004,56(6):947-957
We report the identification by two hybrid screens of two novel similar proteins, called Arabidopsis thaliana gamma carbonic anhydrase like1 and 2 (AtCAL1 and AtCAL2), that interact specifically with putative Arabidopsis thaliana gamma Carbonic Anhydrase (AtCA) proteins in plant mitochondria. The interaction region that was located in the N-terminal 150 amino acids of mature AtCA and AtCA like proteins represents a new interaction domain. In vitro experiments indicate that these proteins are imported into mitochondria and are associated with mitochondrial complex I as AtCAs. All plant species analyzed contain both AtCA and AtCAL sequences indicating that these genes were conserved throughout plant evolution. Structural modeling of AtCAL sequences show a deviation of functionally important active site residues with respect to CAs but could form active interfaces in the interaction with AtCAs. We postulate a CA complex tightly associated to plant mitochondrial complex. 相似文献
27.
Pérez C González FE Pavez V Araya AV Aguirre A Cruzat A Contreras-Levicoy J Dotte A Aravena O Salazar L Catalán D Cuenca J Ferreira A Schiattino I Aguillón JC 《European cytokine network》2004,15(4):364-370
Several single-nucleotide polymorphisms (SNPs) have been identified in the TNF-alpha gene promoter. The transition G-->A at position -308 generates the TNF-alpha1 (G/G) and TNF-alpha2 (G/A or A/A) alleles, where the polymorphic TNF-alpha2 allele is associated with a high, in vitro TNF-alpha expression and an increased susceptibility to diverse illnesses. Here we study the association of the -308 TNF-alpha SNP with the susceptibility for developing aggressive periodontitis (AP), AP combined with type 1 diabetes mellitus (DM) and DM. We also explore the TNF-alpha capability expression and the presence of the -308 polymorphism. For this purpose we recruited 27 individuals with AP (AP+ group), 27 individuals with AP combined with DM (AP+/DM+ group), and 27 individuals with DM without signs of periodontitis upon clinical examination (DM+ group). The control group was comprised of 30 subjects. Genotyping for TNF-alpha promoter was performed by PCR-RFLP analysis. For TNF-alpha expression we used a blood culture system. 相似文献
28.
29.
Orellana M Varela N Guajardo V Araya J Rodrigo R 《Comparative biochemistry and physiology. Toxicology & pharmacology : CBP》2002,131(2):161-166
Cytochrome P450-dependent oxidation of lauric acid, p-nitrophenol and ethanol by liver microsomal fractions were studied in control rats and in animals given either ethanol, red wine, or alcohol-free red wine for 10 weeks. Ethanol increased the total cytochrome P450 and the isoenzyme 2E1 content, as well as the p-nitrophenol hydroxylation and ethanol oxidation. These effects of ethanol treatment were attenuated by red wine administration. Red wine increased the total antioxidant capacity of plasma, whereas the alcohol-free red wine decreased the cytochrome P450 content and decreased the oxidation of lauric acid, p-nitrophenol and ethanol to values lower than control. It is concluded that red wine administration attenuates the ethanol-induced enhancement in liver microsomal parameters dependent on cytochrome P450 2E1 activity, an affect that seems to be accomplished by the non-alcoholic constituents of red wine known to have antioxidant properties. 相似文献
30.
Tantibhedhyangkul J Weerachatyanukul W Carmona E Xu H Anupriwan A Michaud D Tanphaichitr N 《Biology of reproduction》2002,67(1):212-219
We have previously described the zonae pellucidae (ZP) binding ability of a pig sperm surface protein, P68. Our recent results on peptide sequencing of 3 P68 tryptic peptides and molecular cloning of pig testis arylsulfatase A (AS-A) revealed the identity of P68 as AS-A. In this report, we demonstrate the presence of AS-A on the mouse sperm surface and its role in ZP binding. Using anti-AS-A antibody, we have shown by immunoblotting that AS-A was present in a Triton X-100 extract of mouse sperm. The presence of AS-A on the sperm plasma membrane was conclusively demonstrated by indirect immunofluorescence, immunogold electron microscopy, and AS-A's desulfation activity on live mouse sperm. The AS-A remained on the head surface of in vivo capacitated sperm, as revealed by positive immunofluorescent staining of oviductal/uterine sperm. Significantly, the role of mouse sperm surface AS-A on ZP binding was demonstrated by dose-dependent decreases of sperm-ZP binding on sperm pretreatment with anti-AS-A IgG/Fab. Furthermore, Alexa-430 conjugated AS-A bound to mouse ZP of unfertilized eggs but not to fertilized ones, and this level of binding increased and approached saturation with increasing Alexa-430 AS-A concentrations. Moreover, in vivo fertilization was markedly decreased when mouse sperm pretreated with anti-AS-A IgG were artificially inseminated into females. All of these results designated a new function for AS-A in mouse gamete interaction. 相似文献