全文获取类型
收费全文 | 1811篇 |
免费 | 13篇 |
国内免费 | 2篇 |
专业分类
系统科学 | 48篇 |
理论与方法论 | 21篇 |
现状及发展 | 1204篇 |
研究方法 | 73篇 |
综合类 | 408篇 |
自然研究 | 72篇 |
出版年
2020年 | 14篇 |
2018年 | 32篇 |
2017年 | 28篇 |
2016年 | 35篇 |
2015年 | 30篇 |
2014年 | 14篇 |
2013年 | 23篇 |
2012年 | 49篇 |
2011年 | 83篇 |
2010年 | 23篇 |
2009年 | 16篇 |
2008年 | 40篇 |
2007年 | 35篇 |
2006年 | 55篇 |
2005年 | 50篇 |
2004年 | 36篇 |
2003年 | 44篇 |
2002年 | 42篇 |
2001年 | 30篇 |
2000年 | 16篇 |
1999年 | 19篇 |
1992年 | 18篇 |
1991年 | 17篇 |
1985年 | 14篇 |
1984年 | 27篇 |
1983年 | 14篇 |
1982年 | 16篇 |
1981年 | 21篇 |
1979年 | 35篇 |
1978年 | 30篇 |
1977年 | 40篇 |
1976年 | 36篇 |
1975年 | 29篇 |
1974年 | 36篇 |
1973年 | 46篇 |
1972年 | 42篇 |
1971年 | 38篇 |
1970年 | 65篇 |
1969年 | 55篇 |
1968年 | 86篇 |
1967年 | 64篇 |
1966年 | 47篇 |
1965年 | 46篇 |
1964年 | 42篇 |
1963年 | 20篇 |
1962年 | 24篇 |
1961年 | 17篇 |
1959年 | 15篇 |
1958年 | 12篇 |
1957年 | 13篇 |
排序方式: 共有1826条查询结果,搜索用时 0 毫秒
91.
92.
Elizabeth Knyihár 《Cellular and molecular life sciences : CMLS》1971,27(10):1205-1207
Zusammenfassung Fluorid-resistente saure Phosphatase wird aus den kleinen (dunklen) Nervenzellen des Spinalganglions mittels axoplasmatischer Strömung durch die Hinterwurzeln in die Rolando-Substanz des Rückenmarkes transportiert, wo das Enzym in den Nervendendigungen eine freie axoplasmatische Lokalisation aufweist. 相似文献
93.
G. Szabó Elisabeth Anda E. Vándor 《Cellular and molecular life sciences : CMLS》1972,28(12):1429-1430
Zusammenfassung Nach 3 1/2 stündiger Muskelischämie wurde bei Hunden mit Ductus thoracicus-Fistel eine signifikante Zunahme der Milchsäuredehydrogenase-Aktivität im Blutserum und in der Lymphe der anoxischen Extremität bei gleichzeitiger signifikanter arterovenöser Aktivitätsdifferenz beobachtet. Auch Muskelarbeit verursachte eine Erhöhung der Enzymaktivität im Serum und in der Lymphe. Durch Unterbrechen der Verbindung zwischen Venen und Lymphsystem konnte das direkte Eindringen des Enzymproteins in die Blutkapillaren bewiesen werden. 相似文献
94.
J. Řeháček 《Cellular and molecular life sciences : CMLS》1971,27(9):1103-1104
Zusammenfassung Die kontinuierliche Desintegration von Hefen und Bakterien mit Hilfe einer horizontalen, schnellaufenden Labor-Kugelmühle wird beschrieben, deren Arbeitsprinzip auf industrielle Desintegrationsverfahren anwendbar ist. 相似文献
95.
Understanding why some cellular components are conserved across species but others evolve rapidly is a key question of modern biology. Here we show that in Saccharomyces cerevisiae, proteins organized in cohesive patterns of interactions are conserved to a substantially higher degree than those that do not participate in such motifs. We find that the conservation of proteins in distinct topological motifs correlates with the interconnectedness and function of that motif and also depends on the structure of the overall interactome topology. These findings indicate that motifs may represent evolutionary conserved topological units of cellular networks molded in accordance with the specific biological function in which they participate. 相似文献
96.
The Ras family of GTPases in cancer cell invasion 总被引:3,自引:0,他引:3
Hernández-Alcoceba R del Peso L Lacal JC 《Cellular and molecular life sciences : CMLS》2000,57(1):65-76
The ability of tumoral cells to invade surrounding tissues is a prerequisite for metastasis. This is the most life-threatening
event of tumor progression, and so research is intensely focused on elucidating the mechanisms responsible for invasion and
metastasis. The Ras superfamily of GTPases comprises several subfamilies of small GTP-binding proteins whose functions include
the control of proliferation, differentiation, and apoptosis, as well as cytoskeleton organization. The development of metastasis
is a multistep process that requires coordinated activation of proliferation, motility, changes in normal cell-to-cell and
cell-to-substrate contacts, degradation of extracellular matrix, inhibition of apoptosis, and adaptation to an inappropriate
tissue environment. Several members of the Ras superfamily of proteins have been implicated in these processes. The present
review summarizes the current knowledge in this field. 相似文献
97.
A. Fernández-Guasti K. Larsson C. Beyer 《Cellular and molecular life sciences : CMLS》1985,41(11):1414-1416
Summary Intracerebral infusion of (+) bicuculline methiodide, but not of its (–) isomer, in the preoptic area, stimulated masculine sexual behavior in rat as evidenced by a decrease in the number of intromissions preceding ejaculation and a shortening of the ejaculation latency and postejaculatory interval. Data suggest a role of the GABAergic system in mediating masculine sexual behavior.Acknowledgments. Authors wish to thank Ms Elisabeth Wallin for excellent technical assistance and Ms Madelene Kröning for preparing the figures. 相似文献
98.
Postel-Vinay S Véron AS Tirode F Pierron G Reynaud S Kovar H Oberlin O Lapouble E Ballet S Lucchesi C Kontny U González-Neira A Picci P Alonso J Patino-Garcia A de Paillerets BB Laud K Dina C Froguel P Clavel-Chapelon F Doz F Michon J Chanock SJ Thomas G Cox DG Delattre O 《Nature genetics》2012,44(3):323-327
Ewing sarcoma, a pediatric tumor characterized by EWSR1-ETS fusions, is predominantly observed in populations of European ancestry. We performed a genome-wide association study (GWAS) of 401 French individuals with Ewing sarcoma, 684 unaffected French individuals and 3,668 unaffected individuals of European descent and living in the United States. We identified candidate risk loci at 1p36.22, 10q21 and 15q15. We replicated these loci in two independent sets of cases and controls. Joint analysis identified associations with rs9430161 (P = 1.4 × 10(-20); odds ratio (OR) = 2.2) located 25 kb upstream of TARDBP, rs224278 (P = 4.0 × 10(-17); OR = 1.7) located 5 kb upstream of EGR2 and, to a lesser extent, rs4924410 at 15q15 (P = 6.6 × 10(-9); OR = 1.5). The major risk haplotypes were less prevalent in Africans, suggesting that these loci could contribute to geographical differences in Ewing sarcoma incidence. TARDBP shares structural similarities with EWSR1 and FUS, which encode RNA binding proteins, and EGR2 is a target gene of EWSR1-ETS. Variants at these loci were associated with expression levels of TARDBP, ADO (encoding cysteamine dioxygenase) and EGR2. 相似文献
99.
K. Barnet J. Pekárek J. Švejcar J. Johanovský 《Cellular and molecular life sciences : CMLS》1971,27(2):206-207
Zusammenfassung Supernatanten aus Kulturen überempfindlicher Lymphozyten und dem spezifischen Antigen mit MIF-Aktivität können die Entstehung der Pseudopodien normaler Makrophagen verhindern und zeigen nach längerem Kultivieren zuweilen toxische Eigenschaften. 相似文献
100.
Summary The effects of dosage and of cadmium pretreatment on the binding of cadmium in rat bile were studied. With increasing dose a higher cumulative biliary excretion of Cd was observed and a higher percentage of the Cd was excreted in a low-molecular-weight form. On the other hand, after cadmium pretreatment, a decrease in the cumulative biliary excretion of cadmium was observed but a greater percentage of that excreted into the bile was bound to high molecular weight compounds. 相似文献