全文获取类型
收费全文 | 412篇 |
免费 | 1篇 |
国内免费 | 1篇 |
专业分类
系统科学 | 3篇 |
理论与方法论 | 1篇 |
现状及发展 | 231篇 |
研究方法 | 43篇 |
综合类 | 129篇 |
自然研究 | 7篇 |
出版年
2017年 | 5篇 |
2016年 | 4篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 3篇 |
2012年 | 26篇 |
2011年 | 22篇 |
2010年 | 5篇 |
2008年 | 14篇 |
2007年 | 15篇 |
2006年 | 16篇 |
2005年 | 12篇 |
2004年 | 9篇 |
2003年 | 12篇 |
2002年 | 9篇 |
2001年 | 6篇 |
2000年 | 5篇 |
1999年 | 8篇 |
1996年 | 3篇 |
1995年 | 3篇 |
1992年 | 12篇 |
1990年 | 4篇 |
1989年 | 5篇 |
1988年 | 5篇 |
1987年 | 4篇 |
1985年 | 14篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 4篇 |
1980年 | 3篇 |
1979年 | 9篇 |
1978年 | 5篇 |
1977年 | 5篇 |
1975年 | 6篇 |
1974年 | 8篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1971年 | 15篇 |
1970年 | 9篇 |
1969年 | 7篇 |
1968年 | 13篇 |
1967年 | 11篇 |
1966年 | 7篇 |
1965年 | 11篇 |
1964年 | 11篇 |
1963年 | 5篇 |
1962年 | 3篇 |
1961年 | 3篇 |
1956年 | 4篇 |
1955年 | 3篇 |
排序方式: 共有414条查询结果,搜索用时 15 毫秒
41.
Somatic histone H3 alterations in pediatric diffuse intrinsic pontine gliomas and non-brainstem glioblastomas 总被引:1,自引:0,他引:1
Wu G Broniscer A McEachron TA Lu C Paugh BS Becksfort J Qu C Ding L Huether R Parker M Zhang J Gajjar A Dyer MA Mullighan CG Gilbertson RJ Mardis ER Wilson RK Downing JR Ellison DW Zhang J Baker SJ;St. Jude Children's Research Hospital–Washington University Pediatric Cancer Genome Project 《Nature genetics》2012,44(3):251-253
To identify somatic mutations in pediatric diffuse intrinsic pontine glioma (DIPG), we performed whole-genome sequencing of DNA from seven DIPGs and matched germline tissue and targeted sequencing of an additional 43 DIPGs and 36 non-brainstem pediatric glioblastomas (non-BS-PGs). We found that 78% of DIPGs and 22% of non-BS-PGs contained a mutation in H3F3A, encoding histone H3.3, or in the related HIST1H3B, encoding histone H3.1, that caused a p.Lys27Met amino acid substitution in each protein. An additional 14% of non-BS-PGs had somatic mutations in H3F3A causing a p.Gly34Arg alteration. 相似文献
42.
Lifestyle transitions in plant pathogenic Colletotrichum fungi deciphered by genome and transcriptome analyses 总被引:8,自引:0,他引:8
RJ O'Connell MR Thon S Hacquard SG Amyotte J Kleemann MF Torres U Damm EA Buiate L Epstein N Alkan J Altmüller L Alvarado-Balderrama CA Bauser C Becker BW Birren Z Chen J Choi JA Crouch JP Duvick MA Farman P Gan D Heiman B Henrissat RJ Howard M Kabbage C Koch B Kracher Y Kubo AD Law MH Lebrun YH Lee I Miyara N Moore U Neumann K Nordström DG Panaccione R Panstruga M Place RH Proctor D Prusky G Rech R Reinhardt JA Rollins S Rounsley CL Schardl DC Schwartz N Shenoy K Shirasu UR Sikhakolli K Stüber 《Nature genetics》2012,44(9):1060-1065
43.
Two non-standard techniques – the Rasch Model and Nonlinear Principal Components Analysis – originally proposed in other fields are presented and discussed to measure the opinion of European citizens about utilities. The Eurobarometer survey data are thus considered. The potential of both methods and their complementary use are highlighted; in particular the methods allow the questionnaire to be calibrated, the role of different services and aspects of service to be established, and the consumer satisfaction to be assessed and compared among European countries, different years and services. 相似文献
44.
A. Bertolini R. Poggioli W. Ferrari 《Cellular and molecular life sciences : CMLS》1979,35(9):1216-1217
Summary The injection of ACTH 1–24 into the cerebral ventricles in rats markedly reduces the reaction time in the hotplate test and the nociception threshold in the tail-stimulation test. Morphine antagonizes and naloxone potentiates this hyperalgesic effect of ACTH. It is proposed that ACTH peptides play a physiological role in nociception. 相似文献
45.
46.
St. Szára 《Cellular and molecular life sciences : CMLS》1956,12(11):441-442
Zusammenfassung Es wird festgestellt, dass Dimethyltryptamin — bei normalen Versuchspersonen — eine dem Meskalin und dem LSD-25 ähnliche psychotische Wirkung hat. Der durch Dimethyltryptamin induzierte Zustand beginnt schon 3–5 min nach Injektion und verschwindet bereits nach 1 h. Der Urin der Versuchspersonen wurde papier-chromatographisch und kolorimetrisch auf Indolverbindungen geprüft. 3-Indolylessigsäure wird als hauptsächlichstes Abbauprodukt des Dimethyltryptamins gefunden, wovon der grösste Teil in alkali-labiler Form gebunden ist. Die Menge der ausgeschiedenen 5-Hydroxy-indolylessigsäure ist nach dem Versuch wesentlich grösser als vorher. Die Stoffwechselzusammenhänge mit dem psychotischen Zustand werden diskutiert. 相似文献
47.
Zusammenfassung Die bisherigen Angaben eines reichen organischen säurelöslichen Phosphatgehalts der Erythrozyten können für junge Tiere nicht verallgemeinert werden.Bei zahlreichen Säugerarten zeigen die Erythrocyten der Neugeborenen infolge einer sehr niedrigen Konzentration von Phosphoglycerinsäure einen Gehalt an organischem, säurelöslichem Phosphat, der unter demjenigen des ausgewachsenen Tieres liegt.Wir stellen weiterhin fest, dass die bedeutenden Spezies-Unterschiede der Adulttiere in frühen Ontogenesephasen kaum hervortreten. 相似文献
48.
D. Stürchler 《Cellular and molecular life sciences : CMLS》1984,40(12):1357-1362
Summary Malaria prevention is a main challenge for physicians, nurses, health officers and tour operators. The attack rate of malaria in travellers is 1–10/10,000 departures, and the case fatality rate of imported malaria is around 0.5/100. Travellers should be informed about the risk they are going to take, how to protect against mosquito bites, about the antimalarials they will have to take and about what to do when a malaria breakthrough should occur.The 4-aminoquinolines (chloroquine, amodiaquine) remain the drug of choice for the prevention ofPlasmodium vivax and of sensitiveP. falciparum infections. The problem is to find an effective and safe drug combination for travellers to areas whereP. falciparum is either resistant to chloroquine, to Fansidar (the combination of pyrimethamine plus sulfadoxine) or to both. These travellers will probably best be protected by an individually tailored drug combination, which includes amodiaquine or mefloquine as baseline drugs, and a supplementation with Fansidar, Maloprim (the combination of pyrimethamine with dapsone), paludrine or an antibiotic. 相似文献
49.
Vasopressin analogues with selective pressor activity 总被引:2,自引:0,他引:2
50.
E. Stöcker W. Liebscher H. -W. Altmann 《Cellular and molecular life sciences : CMLS》1967,23(9):718-719
Summary During the first wave of parenchymal liver regeneration in adult rats after partial hepatectomy, the cellular synthesis and migration of RNA and the metabolism of protein were studied by autoradiography following an injection of3H-cytidine or3H-l-phenylalanine and double injections of 1 of these precursors +3H-thymidine. The following results were obtained: the synthesis and migration of RNA and the metabolism of protein are enhanced under these conditions of proliferation. In spite of this, the relation of metabolic activity in nucleolus, karyoplasm and cytoplasm remains constant. By double injection techniques it is proved that no differences exist in migration of RNA into the cytoplasm and cytoplasmic protein synthesis between cells with or without DNA synthesizing nuclei.
Mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献
Mit Unterstützung der Deutschen Forschungsgemeinschaft. 相似文献