全文获取类型
收费全文 | 442篇 |
免费 | 14篇 |
国内免费 | 1篇 |
专业分类
457篇 |
出版年
2021年 | 7篇 |
2019年 | 5篇 |
2018年 | 11篇 |
2017年 | 12篇 |
2016年 | 10篇 |
2015年 | 6篇 |
2014年 | 8篇 |
2013年 | 18篇 |
2012年 | 13篇 |
2011年 | 13篇 |
2010年 | 9篇 |
2009年 | 19篇 |
2008年 | 18篇 |
2007年 | 34篇 |
2006年 | 30篇 |
2005年 | 15篇 |
2004年 | 12篇 |
2003年 | 17篇 |
2002年 | 16篇 |
2001年 | 13篇 |
2000年 | 18篇 |
1999年 | 8篇 |
1998年 | 7篇 |
1997年 | 4篇 |
1996年 | 4篇 |
1995年 | 6篇 |
1994年 | 2篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 12篇 |
1989年 | 11篇 |
1988年 | 8篇 |
1987年 | 6篇 |
1986年 | 7篇 |
1985年 | 6篇 |
1984年 | 2篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 4篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 4篇 |
1974年 | 4篇 |
1973年 | 4篇 |
1972年 | 4篇 |
1971年 | 3篇 |
1970年 | 2篇 |
1969年 | 8篇 |
1968年 | 3篇 |
1967年 | 2篇 |
排序方式: 共有457条查询结果,搜索用时 9 毫秒
1.
2.
The extended pattern of multiple esterase forms has been revealed in the hemolymph of wax moth Galleria mellonellalarvae infected by the fungi Metarhizium anisopliae, Beauveria bassianaor Paecilomyces fumoso-roseus. The total esterase activity of the hemolymph also increases during mycosis. Mechanical damage of the cuticle, treatment with deltamethrin, and chilling of the caterpillars induced similar changes in the hemolymph pattern of esterase activity. Presumably, the changed spectrum and activity of the hemolymph esterases during mycosis is due to the damaged cuticle and epidermis cells. 相似文献
3.
4.
5.
6.
Morphofunctional regularities of formation and development of the blood microcirculatory bed in the human tongue have been studied in the prenatal period of morphogenesis. 119 human embryos and fetuses at the age of 5 weeks--9 months have been investigated. A complex of methods have been used: common histological (hematoxylin--eosin, after van Gieson and Mallory), injection of the lingual vessels with 20% suspension of Indian ink--gelatin, transmissive electron microscopy. General regularities of organogenesis, stages of the blood microcirculatory bed development and peculiarities of the process on formation of the primary protocapillary lingual blood bed are revealed. Regularities in structure of the terminal vascular constructions are studied for each structural element of the organ--mucosal membrane, muscles, glands, lingual tonsil. For these elements at the ultrastructural level certain features of the organic specificity in the structure of the blood microcirculatory bed links are determined. 相似文献
7.
Microwave effect on calcium current of the dialysed snail neurons was investigated. Isolated neurons were irradiated by unmodulated and modulated microwaves (900 MHz) with modulation frequency 0,5 divided by 1000 Hz and SAR = 0,1 divided by 20 W/kg. Calcium current increase was shown to be induced by microwave heating. The current increments were proportional to SAR. Microwave effects on the charge distribution of the cell membrane surface and other non-thermal special microwave effects were not detected. 相似文献
8.
S I Alekseev 《Biochimica et biophysica acta》1992,1110(2):178-184
The effect of sulfhydryl reagents on macroscopic inactivation of A-current in internally perfused Lymnaea neurons under voltage-clamp conditions was investigated. It was found that the binding of Hg2+ rather than PHMB with channel proteins resulted in a strong decrease of the peak current and the inactivation rate. Hg2+ markedly influenced the steady-state inactivation but did not change the rate of recovery from inactivation. It was found that both reagents reacted with the same groups of the channel protein and that those are most likely sulfhydryl groups. These groups seemed not to be involved in the gating charge movement. Hg2+ ions can immobilize some part of the gating charge thereby resulting in strong changes of the steady-state inactivation. 相似文献
9.
The effects of a continuous wave or pulse-modulated, 900 MHz microwave field were studied by in vitro assays of rat chemoreceptors. The pulsed field was modulated as rectangular waves at rates of 1, 6, 16, 32, 75, or 100 pps. The pulse-period to pulse-duration ratio was 5 in all cases, and specific absorption rates (SARs) ranged from 0.5 to 18 W/kg. Binding of ligands to cell membranes was differentially affected by exposure to microwaves. For example, binding of H3-glutamic acid to hippocampal cells was not altered by a 15 min exposure to a continuous wave field at 1 W/kg, but binding of H3-dihydroalprenolol to liver-cell membranes of neonates underwent a fivefold decrease under the same field conditions. This effect was not dependent on modulation or on a change in the constant of stimulus-receptor binding but depended on a shedding of the membrane's receptor elements into solution. The magnitude of inhibition correlated with the oxygen concentration in the exposed suspension. Antioxidants (dithiothreitol and ionol) inhibited the shedding of receptor elements. The microwave exposure did not cause an accumulation of products from the peroxidation of lipids (POL). Ascorbate-dependent or non-enzymatic POL was not responsible for the inhibition, and POL was not found in other model systems. However, enzymatic POL mechanisms in localized areas of receptor binding remain a possibility. © 1994 Wiley-Liss, Inc. 相似文献
10.
Effects of non-thermal plasma on mammalian cells 总被引:1,自引:0,他引:1
Kalghatgi S Kelly CM Cerchar E Torabi B Alekseev O Fridman A Friedman G Azizkhan-Clifford J 《PloS one》2011,6(1):e16270
Thermal plasmas and lasers have been widely used in medicine to cut, ablate and cauterize tissues through heating; in contrast, non-thermal plasma produces no heat, so its effects can be selective. In order to exploit the potential for clinical applications, including wound healing, sterilization, blood coagulation, and cancer treatment, a mechanistic understanding of the interaction of non-thermal plasma with living tissues is required. Using mammalian cells in culture, it is shown here that non-thermal plasma created by dielectric barrier discharge (DBD) has dose-dependent effects that range from increasing cell proliferation to inducing apoptosis. It is also shown that these effects are primarily due to formation of intracellular reactive oxygen species (ROS). We have utilized γ-H2AX to detect DNA damage induced by non-thermal plasma and found that it is initiated by production of active neutral species that most likely induce formation of organic peroxides in cell medium. Phosphorylation of H2AX following non-thermal plasma treatment is ATR dependent and ATM independent, suggesting that plasma treatment may lead to replication arrest or formation of single-stranded DNA breaks; however, plasma does not lead to formation of bulky adducts/thymine dimers. 相似文献