全文获取类型
收费全文 | 9180篇 |
免费 | 734篇 |
国内免费 | 6篇 |
出版年
2023年 | 45篇 |
2022年 | 77篇 |
2021年 | 195篇 |
2020年 | 106篇 |
2019年 | 121篇 |
2018年 | 193篇 |
2017年 | 177篇 |
2016年 | 288篇 |
2015年 | 498篇 |
2014年 | 568篇 |
2013年 | 583篇 |
2012年 | 806篇 |
2011年 | 745篇 |
2010年 | 456篇 |
2009年 | 367篇 |
2008年 | 529篇 |
2007年 | 515篇 |
2006年 | 489篇 |
2005年 | 408篇 |
2004年 | 416篇 |
2003年 | 319篇 |
2002年 | 303篇 |
2001年 | 134篇 |
2000年 | 114篇 |
1999年 | 121篇 |
1998年 | 70篇 |
1997年 | 56篇 |
1996年 | 54篇 |
1995年 | 45篇 |
1994年 | 55篇 |
1993年 | 41篇 |
1992年 | 73篇 |
1991年 | 60篇 |
1990年 | 65篇 |
1989年 | 52篇 |
1988年 | 52篇 |
1987年 | 42篇 |
1986年 | 44篇 |
1985年 | 36篇 |
1984年 | 43篇 |
1983年 | 36篇 |
1982年 | 34篇 |
1980年 | 27篇 |
1979年 | 29篇 |
1978年 | 28篇 |
1977年 | 32篇 |
1974年 | 26篇 |
1970年 | 25篇 |
1969年 | 31篇 |
1968年 | 30篇 |
排序方式: 共有9920条查询结果,搜索用时 15 毫秒
1.
2.
Shailesh Kumar Atma P. Dwivedi Vivek Kr. Kashyap A.K. Saxena A.K. Dwivedi Ranjana Srivastava Devi P. Sahu 《Bioorganic & medicinal chemistry letters》2013,23(8):2404-2407
Synthesis of a library of novel trans 6-methoxy-1,1-dimethyl-2-phenyl-3-aryl-2,3-dihydro-1H-inden-4-yloxy alkyl amines and their antimycobacterial activity against drug sensitive and multidrug resistant strains of Mycobacterium tuberculosis have been reported. All the new compounds in the series exhibited MIC between 1.56 and 6.25 μg/ml. Two compounds 1i and 1j with low MIC and low cytotoxicity showed significant reduction in CFU in infected mouse macrophages at 1× MIC concentration. The compound 1i inhibited the growth of M. tuberculosis in mice at 100 mg/kg dose with 1.35 log10 reduction of CFU in lungs tissue and was active against non-replicating Mycobacterium tuberculosis under anaerobic condition. 相似文献
3.
Shira Weingarten-Gabbay Susan Klaeger Siranush Sarkizova Leah R. Pearlman Da-Yuan Chen Kathleen M.E. Gallagher Matthew R. Bauer Hannah B. Taylor W. Augustine Dunn Christina Tarr John Sidney Suzanna Rachimi Hasahn L. Conway Katelin Katsis Yuntong Wang Del Leistritz-Edwards Melissa R. Durkin Christopher H. Tomkins-Tinch Pardis C. Sabeti 《Cell》2021,184(15):3962-3980.e17
4.
5.
J. Dierschke T. Krüger F. Hüttmann F. Bairlein Kerstin Müller G. Scheiffarth H. -W. Helb W. Irsch W. Lantermann B. Haubitz W. Winkel und J. Haffer 《Journal of Ornithology》2003,144(4):484-498
Ohne Zusammenfassung 相似文献
6.
Michael D. Jensen Ji?í Bajnárek Sang Yeoup Lee Soren Nielsen Christina Koutsari 《Journal of lipid research》2009,50(9):1863-1869
The relationship between overnight postabsorptive (fasting) respiratory exchange ratio (RER) and plasma FFA concentrations was addressed using data from three separate protocols, each of which involved careful control of the antecedent diet. Protocol 1 examined the relationship between fasting RER and the previous daytime RER. In Protocol 2 fasting, RER and plasma palmitate concentrations were measured in 29 women and 31 men (body mass index <30 kg·m−2). Protocol 3 analyzed data from Nielsen et al. (Nielsen, S., Z. K. Guo, J. B. Albu, S. Klein, P. C. O''Brien, M. D. Jensen. 2003. Energy expenditure, sex and endogenous fuel availability in humans. J. Clin. Invest. 111: 981-988.) to understand how fasting RER and palmitate concentrations relate within individuals during four consecutive measurements. The results were as follows: 1) Fasting RER was correlated (r = 0.74, P < 0.001) with the previous day''s average RER, and less so with RER variability. 2) Fasting RER was correlated (r = −0.39, P = 0.007) with fasting plasma palmitate concentrations. 3) The pattern of the RER/palmitate relationship was similar within individuals and between individuals; a negative slope was observed significantly more often than a positive slope (χ2 test; P < 0.001). Our findings suggest that, despite a fixed food quotient, the slight departures from energy equilibrium in a controlled General Clinical Research Center environment can effect plasma FFA concentrations. We suggest that including indirect calorimetry as part of FFA metabolism studies may aid in data interpretation. 相似文献
7.
8.
Kazazoglou Theodosia Panagiotou Christina Mihailidou Chrysovalantou Kokkinopoulou Ioanna Papadopoulou Anna Moutsatsou Paraskevi 《Molecular and cellular biochemistry》2021,476(12):4471-4485
Molecular and Cellular Biochemistry - Glucocorticoids (GCs) regulate astrocyte function, while glutamine synthetase (GS), an enzyme highly expressed in astrocytes, is one of the most remarkable... 相似文献
9.
DNA was efficiently and quantitatively isolated from extremely small quantities of mycelia (0.1–10 mg) of different phytopathogenic
moulds by grinding freeze-dried mycelia with glass beads and then using a commercial DNA extraction kit. The efficiency of
disruption of the mycelia and the quantitative DNA extraction was proved by microscopy and the quantification of isolated
DNA by real time PCR.
Presented at the 27th Mykotoxin-Workshop, Dortmund, Germany, June 13–15, 2005
Financial support: German Research Foundation (DFG grant Pr 708/2). J.M. thanks the Cusanuswerk for a doctoral scholarship 相似文献
10.
Plant chloroplasts are not only the main cellular location for storage of elemental iron (Fe), but also the main site for Fe, which is incorporated into chlorophyll, haem and the photosynthetic machinery. How plants measure internal Fe levels is unknown. We describe here a new Fe‐dependent response, a change in the period of the circadian clock. In Arabidopsis, the period lengthens when Fe becomes limiting, and gradually shortens as external Fe levels increase. Etiolated seedlings or light‐grown plants treated with plastid translation inhibitors do not respond to changes in Fe supply, pointing to developed chloroplasts as central hubs for circadian Fe sensing. Phytochrome‐deficient mutants maintain a short period even under Fe deficiency, stressing the role of early light signalling in coupling the clock to Fe responses. Further mutant and pharmacological analyses suggest that known players in plastid‐to‐nucleus signalling do not directly participate in Fe sensing. We propose that the sensor governing circadian Fe responses defines a new retrograde pathway that involves a plastid‐encoded protein that depends on phytochromes and the functional state of chloroplasts. 相似文献