全文获取类型
收费全文 | 841篇 |
免费 | 110篇 |
专业分类
951篇 |
出版年
2020年 | 10篇 |
2019年 | 11篇 |
2018年 | 8篇 |
2017年 | 16篇 |
2016年 | 9篇 |
2015年 | 25篇 |
2014年 | 21篇 |
2013年 | 25篇 |
2012年 | 22篇 |
2011年 | 24篇 |
2010年 | 23篇 |
2009年 | 18篇 |
2008年 | 25篇 |
2007年 | 31篇 |
2006年 | 26篇 |
2005年 | 31篇 |
2004年 | 23篇 |
2003年 | 19篇 |
2002年 | 19篇 |
2001年 | 20篇 |
2000年 | 18篇 |
1999年 | 23篇 |
1998年 | 10篇 |
1996年 | 10篇 |
1995年 | 10篇 |
1992年 | 12篇 |
1991年 | 23篇 |
1990年 | 10篇 |
1988年 | 14篇 |
1987年 | 12篇 |
1986年 | 16篇 |
1985年 | 11篇 |
1984年 | 23篇 |
1983年 | 12篇 |
1982年 | 15篇 |
1980年 | 9篇 |
1979年 | 21篇 |
1977年 | 9篇 |
1976年 | 17篇 |
1975年 | 16篇 |
1974年 | 17篇 |
1973年 | 15篇 |
1972年 | 14篇 |
1971年 | 17篇 |
1970年 | 19篇 |
1969年 | 13篇 |
1968年 | 14篇 |
1967年 | 12篇 |
1966年 | 12篇 |
1965年 | 9篇 |
排序方式: 共有951条查询结果,搜索用时 0 毫秒
41.
42.
Cyclocarya paliurus (Batalin) Iljinskaya, an endemic tree of China and the sole living species of a very distinctive genus of Juglandaceae, is described, and an overview of its phylogenetic relationships and fossil record is provided. Fossil occurrences of Cyclocarya indicate that the genus was already differentiated around 55 million years ago and was once widespread in the Northern Hemisphere. The current restriction of Cyclocarya to China is the result of regional extinction in North America and Europe during the Cenozoic. 相似文献
43.
44.
45.
Arkan Abadi Justin D. Crane Daniel Ogborn Bart Hettinga Mahmood Akhtar Andrew Stokl Lauren MacNeil Adeel Safdar Mark Tarnopolsky 《PloS one》2013,8(4)
Antioxidant supplements are widely consumed by the general public; however, their effects of on exercise performance are controversial. The aim of this study was to examine the effects of an antioxidant cocktail (α-lipoic acid, vitamin E and coenzyme Q10) on exercise performance, muscle function and training adaptations in mice. C57Bl/J6 mice were placed on antioxidant supplement or placebo-control diets (n = 36/group) and divided into trained (8 wks treadmill running) (n = 12/group) and untrained groups (n = 24/group). Antioxidant supplementation had no effect on the running performance of trained mice nor did it affect training adaptations; however, untrained female mice that received antioxidants performed significantly better than placebo-control mice (p ≤ 0.05). Furthermore, antioxidant-supplemented females (untrained) showed elevated respiratory capacity in freshly excised muscle fibers (quadriceps femoris) (p ≤ 0.05), reduced oxidative damage to muscle proteins (p ≤ 0.05), and increased expression of mitochondrial proteins (p ≤ 0.05) compared to placebo-controls. These changes were attributed to increased expression of proliferator-activated receptor gamma coactivator 1α (PGC-1α) (p ≤ 0.05) via activation of AMP-activated protein kinase (AMPK) (p ≤ 0.05) by antioxidant supplementation. Overall, these results indicate that this antioxidant supplement exerts gender specific effects; augmenting performance and mitochondrial function in untrained females, but does not attenuate training adaptations. 相似文献
46.
47.
Linda M. Delahanty Thomas A. Wadden Pamela J. Goodwin Catherine M. Alfano Cynthia A. Thomson Melinda L. Irwin Marian L. Neuhouser Tracy E. Crane Elizabeth Frank Patricia A. Spears Bonnie P. Gillis Dawn L. Hershman Electra D. Paskett Judith Hopkins Vanessa Bernstein Vered Stearns Julia White Clifford Hudis Eric P. Winer Lisa A. Carey Ann H. Partridge Jennifer A. Ligibel 《Obesity (Silver Spring, Md.)》2022,30(1):28-38
48.
Prakash C. Misra Theodore A. Craig Frederick L. Crane 《Journal of bioenergetics and biomembranes》1984,16(2):143-152
Carrot (Daucus carota L.) cells grown in suspension culture oxidized exogeneous NADH. The NADH oxidation was able to stimulate K+ (86Rb+) transport into cells, but it did not affect sucrose transport.N,N'-Dicyclohexyl-carbodiimide, diethylstilbestrol, and oligomycin, which only partially inhibited NADH oxidation, almost completely collapsed the K+ (86Rb+) transport. Vanadate, which is less effective as an ion transport inhibitor, was less effective in inhibiting the NADH-driven transport of K+ (86Rb+).p-Fluormethoxycarbonylcyanide phenylhydrazone inhibits the K+ transport over 90% including that induced by NADH. The results are interpreted as evidence that a plasma membrane redox system in root cells is closely associated with the ATPase which can drive K+ transport. Because of the inhibitor effects, it appears that membrane components common to the redox system and ATPase function in the transport of K+. 相似文献
49.
Calmodulin antagonists inhibit electron transport in photosystem II of spinach chloroplasts 总被引:3,自引:0,他引:3
R Barr K S Troxel F L Crane 《Biochemical and biophysical research communications》1982,104(4):1182-1188
Chlorpromazine, phenothiazine and trifluoperazine, known as calmodulin antagonists, inhibit electron transport in Photosystem II of spinach chloroplasts in concentrations from 20–500 μM. The inhibition site is located on the diphenyl carbazide to indophenol pathway in Tris-treated chloroplasts, indicating that water oxidation is not affected by these drugs. Ca2+ ions, bound to chloroplast membranes before the addition of calmodulin antagonists, can protect against inhibition up to 25% of the electron transport rate. In presence of A23187, the Ca2+-specific ionophore, Ca2+ ions provide less protection against inhibition by the 3 calmodulin antagonists used. A possible role of a calmodulin-like protein in spinach chloroplasts is postulated. 相似文献
50.
Many of the latest trends in vaccine development are dependent on immunological adjuvants that mediate and promote a wide variety of immune responses. One promising adjuvant candidate, monophosphoryl lipid A (MPL) immunostimulant, is being investigated with many of these new vaccine approaches in either preclinical or clinical trials. This is possible because different vehicle formulations can significantly influence the type of immunological response MPL promotes. Procedures are provided for formulating MPL in an aqueous vehicle or an oil-in-water emulsion. These two MPL formulations can be beneficial for most vaccine approaches being investigated today. 相似文献