全文获取类型
收费全文 | 6045篇 |
免费 | 455篇 |
国内免费 | 3篇 |
出版年
2023年 | 28篇 |
2022年 | 22篇 |
2021年 | 68篇 |
2020年 | 53篇 |
2019年 | 62篇 |
2018年 | 167篇 |
2017年 | 125篇 |
2016年 | 185篇 |
2015年 | 329篇 |
2014年 | 339篇 |
2013年 | 431篇 |
2012年 | 506篇 |
2011年 | 484篇 |
2010年 | 321篇 |
2009年 | 242篇 |
2008年 | 397篇 |
2007年 | 400篇 |
2006年 | 387篇 |
2005年 | 378篇 |
2004年 | 326篇 |
2003年 | 312篇 |
2002年 | 272篇 |
2001年 | 43篇 |
2000年 | 47篇 |
1999年 | 50篇 |
1998年 | 40篇 |
1997年 | 35篇 |
1996年 | 26篇 |
1995年 | 27篇 |
1994年 | 16篇 |
1993年 | 27篇 |
1992年 | 24篇 |
1991年 | 16篇 |
1990年 | 26篇 |
1989年 | 15篇 |
1988年 | 24篇 |
1987年 | 14篇 |
1986年 | 26篇 |
1985年 | 13篇 |
1984年 | 20篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 11篇 |
1980年 | 8篇 |
1979年 | 13篇 |
1978年 | 16篇 |
1977年 | 9篇 |
1974年 | 11篇 |
1973年 | 10篇 |
1968年 | 10篇 |
排序方式: 共有6503条查询结果,搜索用时 15 毫秒
971.
972.
973.
The mechanisms by which peptidergic signals are terminated have been the center of multiple studies leading to the discoveries of novel proteolytic activities. When studying the catabolic fate of neurotensin (NT) in brain and gastrointestinal tract, we detected a novel activity belonging to the metallopeptidases class and apparently distinct from previously known enzymes. Purification and cloning confirmed that this NT-degrading neutral metalloendopeptidase activity was indeed original. It was named endopeptidase 3.4.24.16 according to the IUBMB nomenclature and later, referred to as neurolysin. This review tells the history of neurolysin from its initial detection to its purification, cloning, design of specific inhibitors as well as in vitro and in vivo pharmacological studies aimed at delineating its role in the control of NT function. Finally, we discuss very recent advances suggesting a potential role of neurolysin in pathologies. 相似文献
974.
975.
Dávid Kurszán Jász Ágnes Lilla Szilágyi Eszter Tuboly Bálint Baráth Anett Roxána Márton Petra Varga Gabriella Varga Dániel Érces Árpád Mohácsi Anna Szabó Renáta Bozó Kamilla Gömöri Anikó Görbe Mihály Boros Petra Hartmann 《Journal of cellular and molecular medicine》2021,25(11):5113-5123
Albeit previous experiments suggest potential anti-inflammatory effect of exogenous methane (CH4) in various organs, the mechanism of its bioactivity is not entirely understood. We aimed to investigate the potential mitochondrial effects and the underlying mechanisms of CH4 in rat cardiomyocytes and mitochondria under simulated ischaemia/reperfusion (sI/R) conditions. Three-day-old cultured cardiomyocytes were treated with 2.2% CH4-artificial air mixture during 2-hour-long reoxygenation following 4-hour-long anoxia (sI/R and sI/R + CH4, n = 6-6), with normoxic groups serving as controls (SH and SH + CH4; n = 6-6). Mitochondrial functions were investigated with high-resolution respirometry, and mitochondrial membrane injury was detected by cytochrome c release and apoptotic characteristics by using TUNEL staining. CH4 admixture had no effect on complex II (CII)-linked respiration under normoxia but significantly decreased the complex I (CI)-linked oxygen consumption. Nevertheless, addition of CH4 in the sI/R + CH4 group significantly reduced the respiratory activity of CII in contrast to CI and the CH4 treatment diminished mitochondrial H2O2 production. Substrate-induced changes to membrane potential were partially preserved by CH4, and additionally, cytochrome c release and apoptosis of cardiomyocytes were reduced in the CH4-treated group. In conclusion, the addition of CH4 decreases mitochondrial ROS generation via blockade of electron transport at CI and reduces anoxia-reoxygenation-induced mitochondrial dysfunction and cardiomyocyte injury in vitro. 相似文献
976.
Ross A. Robinson Samuel C. Griffiths Lieke L. van de Haar Tomas Malinauskas Eljo Y. van Battum Pavol Zelina Rebekka A. Schwab Dimple Karia Lina Malinauskaite Sara Brignani Marleen H. van den Munkhof Özge Düdükcü Anna A. De Ruiter Dianne M.A. Van den Heuvel Benjamin Bishop Jonathan Elegheert A. Radu Aricescu R. Jeroen Pasterkamp Christian Siebold 《Cell》2021,184(8):2103-2120.e31
- Download : Download high-res image (287KB)
- Download : Download full-size image
977.
Charlotte Bernard Bixente Dilharreguy Michèle Allard Hélène Amieva Fabrice Bonnet Frédéric Dauchy Carinne Greib Patrick Dehail Gwéna?lle Catheline for the ANRS CO Aquitaine cohort study group 《PloS one》2013,8(7)
Motor impairment is highly prevalent in HIV-infected patients. Here, we assess associations between peripheral muscular deficits as evaluated by the 5 sit-to-stand test (5STS) and structural integrity of the motor system at a central level. Eighty-six HIV-infected patients receiving combination antiretroviral therapy and with no major cerebral events, underwent an MRI scan and the 5STS. Out of 86 participants, forty presented a score greater than two standard deviations above mean normative scores calculated for the 5STS and were therefore considered as motor-impaired. MRI-structural cerebral parameters were compared to the unimpaired participants. Fractional Anisotropy (FA), Axial Diffusivity (AD) and Radial Diffusivity (RD), reflecting microstructural integrity, were extracted from Diffusion-Tensor MRI. Global and regional cerebral volumes or thicknesses were extracted from 3D-T1 morphological MRI. Whereas the two groups did not differ for any HIV variables, voxel-wise analysis revealed that motor-impaired participants present low FA values in various cortico-motor tracts and low AD in left cortico-spinal tract. However, they did not present reduced volumes or thicknesses of the precentral cortices compared to unimpaired participants. The absence of alterations in cortical regions holding motor-neurons might argue against neurodegenerative process as an explanation of White Matter (WM) disorganization. 相似文献
978.
979.
Jacek Najda Jan Gmiński Marian Dróżdż Alojzy danch 《Biological trace element research》1993,37(2-3):107-114
The influence of silicon treatment on the levels of calcium and magnesium in blood serum and tissues was studied in rats.
The concentrations of both elements were estimated in samples of sera and tissues of rats receiving per os a soluble, inorganic
silicon compound—sodium metasilicate nonahydrate (Na2SiO3·9H2O (REACHIM, USSR)), dissolved in the animals' drinking water. A decrease of magnesium concentration in serum was observed
with accompanying elevation of registered calcemia. Moreover, a reduction of tissue calcium levels was found with a simultaneous
increase of magnesium tissue pool.
The results provide evidence for silicon involvement in mineral metabolism. It could result in a modification of pathological
processes concerning bone tissue. 相似文献
980.