全文获取类型
收费全文 | 305篇 |
免费 | 19篇 |
出版年
2021年 | 4篇 |
2020年 | 3篇 |
2018年 | 2篇 |
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 15篇 |
2014年 | 18篇 |
2013年 | 22篇 |
2012年 | 19篇 |
2011年 | 17篇 |
2010年 | 7篇 |
2009年 | 15篇 |
2008年 | 16篇 |
2007年 | 14篇 |
2006年 | 15篇 |
2005年 | 16篇 |
2004年 | 11篇 |
2003年 | 8篇 |
2002年 | 5篇 |
2001年 | 15篇 |
2000年 | 10篇 |
1999年 | 6篇 |
1998年 | 12篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 4篇 |
1994年 | 5篇 |
1993年 | 2篇 |
1992年 | 2篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1985年 | 3篇 |
1984年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1974年 | 2篇 |
1973年 | 1篇 |
1971年 | 2篇 |
1970年 | 2篇 |
1969年 | 2篇 |
1968年 | 1篇 |
1967年 | 1篇 |
1966年 | 1篇 |
排序方式: 共有324条查询结果,搜索用时 15 毫秒
1.
Anna Romanowska Ewa Katzenellenbogen Magorzata Kuakowska rzej Gamian Danuta Witkowska Marian Mulczyk Elbieta Romanowska 《FEMS microbiology letters》1988,47(3):151-155
Abstract Lipopolysaccharides (LPS) of 33 strains of Hafnia alvei were isolated and purified. LPS content of the dry bacterial mass ranged from 1.2 to 4.5%. All examined lipopolysaccharides contained glucose, glucosamine, heptose, 3-deoxy-octulosonic acid and often galactose. Rhamnose, mannose, galactosamine, mannosamine and unidentified amino sugars were found in some H. alvei strains. Sialic acid was present in LPS of one strain. d -3-Hydroxybutyryl groups also were identified in lipopolysaccharides of 5 strains of this genus.
SDS-PAGE of the lipopolysaccharides was presented in the paper. According to these results two core types exist in H. alvei . 相似文献
SDS-PAGE of the lipopolysaccharides was presented in the paper. According to these results two core types exist in H. alvei . 相似文献
2.
A study of intermediates involved in the folding pathway for recombinant human macrophage colony-stimulating factor (M-CSF): evidence for two distinct folding pathways. 总被引:2,自引:1,他引:1 下载免费PDF全文
J. A. Wilkins J. Cone Z. I. Randhawa D. Wood M. K. Warren H. E. Witkowska 《Protein science : a publication of the Protein Society》1993,2(2):244-254
The folding pathway for a 150-amino acid recombinant form of the dimeric cytokine human macrophage colony-stimulating factor (M-CSF) has been studied. All 14 cysteine residues in the biologically active homodimer are involved in disulfide linkages. The structural characteristics of folding intermediates blocked with iodoacetamide reveal a rapid formation of a small amount of a non-native dimeric intermediate species followed by a slow progression via both monomeric and dimeric intermediates to the native dimer. The transition from monomer to fully folded dimer is complete within 25 h at room temperature at pH 9.0. The blocked intermediates are stable under conditions of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and thus represent various dimeric and folded monomeric species of the protein with different numbers of disulfide bridges. Peptide mapping and electrospray ionization mass spectrometry revealed that a folded monomeric species of M-CSF contained three of the four native disulfide bridges, and this folded monomer also showed some biological activity in a cell-based assay. The results presented here strongly suggest that M-CSF can fold via two different pathways, one involving monomeric intermediates and another involving only dimeric intermediates. 相似文献
3.
M Witkowska 《Polski tygodnik lekarski (Warsaw, Poland : 1960)》1992,47(40-41):936-940
Mechanism of action, hemodynamic effects, efficacy of both shortterm and chronic administration of available inotropic drugs are discussed. An emphasis is on the possible mechanism of detrimental sequelae of the chronic inotropic stimulation of the failing heart. 相似文献
4.
The purpose of the present study was to demonstrate visually and localize the presence of serotonin (5-HT) in the ovary and oviduct of the domestic hen using a histochemical Falck-Hillarp method. Experiments were carried out on White Leghorn laying hens with no egg in the shell gland. The specific yellow fluorescence, indicating the presence of 5-HT, was found both in the ovary and all examined oviductal parts. The strongest fluorescence was present in the ovarian stroma containing small follicles with a diameter under 4 mm. In the wall of the largest preovulatory follicle a very strong fluorescence was located mainly in the theca layer. In the oviductal parts, the intensity of 5-HT fluorescence in the infundibulum and magnum was fairly strong, whereas in the isthmus and shell gland it was weak. Fluorescence seen in the infundibulum, magnum, and isthmus was primarily localized along the luminal borders of the fold surface epithelium. In the shell gland 5-HT fluorescence was found within the uterine folds, especially in the tubular glands. Moreover, the presence of an egg in the definite oviductal segment (infundibulum or isthmus) increased the intensity of yellow fluorescence in this part. 相似文献
5.
6.
The effect of neurotensin on submaximally-stimulated hepatobiliary and pancreatic secretion was studied in 6 healthy subjects. An intravenous infusion of neurotensin 1.4 ± 0.3 pmol/kg/min, designed to reproduce plasma neurotensin immunoreactivity levels within the physiological range, produced a significant increase in pancreatic bicarbonate output. Plasma concentrations of pancreatic polypeptide rose by 83 ± 16 pmol/l and were associated with a small reduction in trypsin, but no significant change in bilirubin outputs. 相似文献
7.
8.
9.
10.
AB Zarafi AM Emechebe AD Akpa O Alabi 《Archives Of Phytopathology And Plant Protection》2013,46(4):261-268
Pearl millet downy mildew (DM) incidence, severity and yield losses of two pearl millet varieties (local and improved) due to the disease were determined in the field. Significant differences in the disease incidence and severity were recorded in the plots sown with metalaxyl-treated seeds and those sown with non-treated seeds, indicating the efficacy of the fungicide on the fungus. Yield losses due to non-treatment of seeds with metalaxyl was 40.88 and 45.39% in a local variety and 43.00 and 18.60% in an improved variety in the 2000 and 2001 cropping seasons respectively. Significant differences between plots sown with metalaxyl-treated and those sown with non-treated seeds were obtained for other yield components such as 1000-grains weight, panicle length and weight. 相似文献