全文获取类型
收费全文 | 792203篇 |
免费 | 89132篇 |
国内免费 | 583篇 |
专业分类
881918篇 |
出版年
2018年 | 6865篇 |
2016年 | 9309篇 |
2015年 | 13139篇 |
2014年 | 15159篇 |
2013年 | 21797篇 |
2012年 | 24314篇 |
2011年 | 24820篇 |
2010年 | 16615篇 |
2009年 | 15280篇 |
2008年 | 21803篇 |
2007年 | 22799篇 |
2006年 | 21015篇 |
2005年 | 20357篇 |
2004年 | 20154篇 |
2003年 | 19425篇 |
2002年 | 18859篇 |
2001年 | 34076篇 |
2000年 | 34282篇 |
1999年 | 27585篇 |
1998年 | 10074篇 |
1997年 | 10475篇 |
1996年 | 10071篇 |
1995年 | 9239篇 |
1994年 | 9258篇 |
1993年 | 9093篇 |
1992年 | 22938篇 |
1991年 | 22357篇 |
1990年 | 22069篇 |
1989年 | 21776篇 |
1988年 | 20046篇 |
1987年 | 19147篇 |
1986年 | 17633篇 |
1985年 | 17900篇 |
1984年 | 15000篇 |
1983年 | 13004篇 |
1982年 | 10176篇 |
1981年 | 9174篇 |
1980年 | 8550篇 |
1979年 | 14320篇 |
1978年 | 11197篇 |
1977年 | 10443篇 |
1976年 | 9859篇 |
1975年 | 10556篇 |
1974年 | 11465篇 |
1973年 | 11262篇 |
1972年 | 10415篇 |
1971年 | 9505篇 |
1970年 | 8054篇 |
1969年 | 8011篇 |
1968年 | 7256篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
961.
962.
963.
Confluent rabbit corneal endothelial cells incubated in the absence of serum do not produce fibrinogen. When exogenous fibronectin is added to these cultures, fibrinogen production is observed. Fibronectin concentrations stimulate fibrinogen synthesis by endothelial cells in a dose-response fashion. This direct interaction of fibronectin and fibrinogen may be important in both wound healing processes and pathological states. 相似文献
964.
E C Chew 《Acta anatomica》1980,108(2):156-159
Tannic acid was found to fix and stain glycocalyx heavily. After removal of the major component of surface glycopeptides by trypsin, the surface coat was stained vaguely, and after the treatment with collagenase, the surface coat was moderately stained. It is concluded that tannic acid stained non-specific surface glycopeptides. 相似文献
965.
Contrary to results published recently, we observe three, rather than two, phenotypes for the enzyme glucosephosphate isomerase (EC 5.3.1.9) from sheep. The phenotypic electrophoretic patterns conform to the patterns observed for this dimeric enzyme in other species. Genotype frequencies in a flock of Southdowns do not deviate significantly from those predicted under the assumption of the Hardy-Weinberg equilibrium. A remarkable observation is that the electrophoretically distinct phenotypes of GPI are largely or entirely obliterated by the addition of 1-10 mmol/l MgCl2 to the electrophoretic buffers. Modification of the usual staining recipe for GPI result in greater resolution and shorter staining times. 相似文献
966.
967.
Zusammenfassung Eine Reihe von Rhodopseudomonas palustris-Stämmen aus verschiedenen Herkünften wurden vergleichend unter Verwendung folgender Merkmale untersucht: Substratverwertung, in vivo-Absorptionsspektrum und Serologie der O-Antigene. Die gegen 2 Stämme gerichteten Antiseren zeigen hohe Spezifität. Die Verwendbarkeit der serologischen Kreuzreaktion für taxonomische Untersuchungen bei photosynthetischen Bakterien wird diskutiert.
Im Text verwendete Abkürzungen LPS Lipopolysaccharid - R Rhodospirillum - Rps. Rhodopseudomonas - i.m. intramuskulär - s.c. subcutan - i.v. intravenös 相似文献
On the taxonomy of Rhodopseudomonas palustris
Summary Strains of Rhodopseudomonas palustris isolated from different habitats were compared with respect to their taxonomic features. All strains grew very well on formiate, acetate, propionate, butyrate, aspartate, inositol, ethanol, fructose, and p-amino-benzoate, respectively, as single carbon source. Most of the strains were able to use benzoic acid or glucose, too. But alanine was not found to be a good substrate. The maxima of the bacteriochlorophyll in-vivo-absorption spectra were estimated to be 376, 589, 802–805, and 858–875 nm. The shift of the infrared peak in the different strains is loosely correlated with the change of the carotenoid in vivo spectrum, the maxima of which were measured to be 470–480 nm (shoulder) 495–505 nm, and 520–545 nm (shoulder). Antisera were prepared against the strains 1e5 and 11/1. It was demonstrated that these antisera were directed against the lipopolysaccharides (O-antigen) of these bacteria. The antigen of 1e5 does not cross react with the antigen of 11/1. Strain 1e5 is the only one of 17 strains tested which is sensitive to the bacteriophage Rp1. The antigen of this strain cross reacted only with the antigen of strain K1. In contrast, the antigen of strain 11/1 cross reacted in some degree with most of the tested strains of Rps. palustris. No or very weak cross reaction was observed between the antigens of Rps. palustris (1e5, 11/1) and Rps. capsulata, Rps. spheroides, or R. rubrum, respectively. In contrast to 11/1 only heat-killed cells of strain 1e5 were agglutinated by anti-1e5.
Im Text verwendete Abkürzungen LPS Lipopolysaccharid - R Rhodospirillum - Rps. Rhodopseudomonas - i.m. intramuskulär - s.c. subcutan - i.v. intravenös 相似文献
968.
A search for differences due to ANS staining (hydrophobia), Con A and PNA binding capacity, and birefringence was carried out on stratified epithelia of rat skin and human breast cells (HBC) in culture. Microfluorimetric measurements confirm that the ANS fluorescence of the stratum corneum from adults is higher than that of newborns. HBC exhibited an unexpected deep ANS-fluorescence. Differences in the binding capacity of the epithelial layers to Con A and PNA were detected with advancing age. Retardation measurements revealed that the form birefringence of the stratum corneum is higher in adult animals specially as revealed by the fact that its form birefringence curve branch from n = 1.414 to n = 1.479 is steeper, i.e. depict higher values. The strong birefringence of the cytoplasmic tonofilaments presented by cultured human breast cells was considered an unexpected finding and attributed to changes that the cells underwent following the in vitro conditions. 相似文献
969.
970.