全文获取类型
收费全文 | 1481篇 |
免费 | 35篇 |
专业分类
1516篇 |
出版年
2022年 | 10篇 |
2021年 | 18篇 |
2020年 | 18篇 |
2019年 | 14篇 |
2018年 | 30篇 |
2017年 | 31篇 |
2016年 | 33篇 |
2015年 | 26篇 |
2014年 | 39篇 |
2013年 | 58篇 |
2012年 | 59篇 |
2011年 | 74篇 |
2010年 | 47篇 |
2009年 | 45篇 |
2008年 | 79篇 |
2007年 | 85篇 |
2006年 | 58篇 |
2005年 | 49篇 |
2004年 | 58篇 |
2003年 | 55篇 |
2002年 | 55篇 |
2001年 | 47篇 |
2000年 | 28篇 |
1999年 | 36篇 |
1994年 | 7篇 |
1992年 | 25篇 |
1991年 | 30篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 23篇 |
1987年 | 21篇 |
1986年 | 19篇 |
1985年 | 27篇 |
1984年 | 16篇 |
1983年 | 12篇 |
1982年 | 9篇 |
1979年 | 15篇 |
1978年 | 12篇 |
1976年 | 9篇 |
1975年 | 20篇 |
1974年 | 15篇 |
1973年 | 12篇 |
1972年 | 12篇 |
1971年 | 14篇 |
1970年 | 8篇 |
1969年 | 12篇 |
1968年 | 9篇 |
1967年 | 15篇 |
1966年 | 13篇 |
1965年 | 9篇 |
排序方式: 共有1516条查询结果,搜索用时 15 毫秒
51.
Electron-microscopic and electron-cytochemical method were used to indicate the capability of Pseudomonas mallei (str. N 10230) to produce extracellular slime during the agent growth on the meat-peptone agar. In case of guinea pigs infection the agent forms a capsule that defends the pathogen from phagocytosis. 相似文献
52.
Popov A. Yu. Tretinnikov P. V. Gusakov E. Z. Simonchik L. V. 《Plasma Physics Reports》2020,46(1):35-40
Plasma Physics Reports - The expression is obtained for the high-frequency quadratic susceptibility of the strongly inhomogeneous magnetoactive plasma, which describes the nonlinear coupling... 相似文献
53.
Russian Journal of Plant Physiology - Changes in the activity of superoxide dismutase (SOD), ascorbate peroxidase (APX), and catalase (CAT) for the plants Nicotiana tabacum L. and Secale cereale L.... 相似文献
54.
Demin Konstantin A. Refeld Aleksandr G. Bogdanova Anna A. Prazdnova Evgenya V. Popov Igor V. Kutsevalova Olga Yu. Ermakov Alexey M. Bren Anzhelica B. Rudoy Dmitry V. Chistyakov Vladimir A. Weeks Richard Chikindas Michael L. 《Probiotics and antimicrobial proteins》2021,13(4):926-948
Probiotics and Antimicrobial Proteins - Pathogenic Candida and infections caused by those species are now considered as a serious threat to public health. The treatment of candidiasis is... 相似文献
55.
Russian Journal of Plant Physiology - Changes in invertase activities were studied upon hardening of chilling-sensitive (Nicotiana tabacum L.) and cold-resistant (Arabidopsis thaliana Heynh. (L.))... 相似文献
56.
I. N. Bolotov A. A. Makhrov Yu. V. Bespalaya I. V. Vikhrev O. V. Aksenova P. E. Aspholm M. Yu. Gofarov A. N. Ostrovskii I. Yu. Popov I. S. Pal’tser M. Rudzite M. Rudzitis I. S. Voroshilova S. E. Sokolova 《Biology Bulletin》2013,40(2):221-231
This paper continues a discussion on the number of pearl mussel species of the genus Margaritifera in northern Europe. A biometric study of 1711 pearl mussel Margaritifera margaritifera shells from 15 rivers in Russia and Latvia (basins of the White and Baltic seas) has been conducted. All the examined samples fall into two groups: the northern group (with the shells more flattened on average, f. margaritifera) and the southern one (with more convex shells, f. elongata); the boundary between these groups is at 63° N. Analysis of intrapopulation variation has shown that the samples contain individuals that correspond to f. margaritifera, f. elongata, and f. borealis. However, any hiatus between these forms is absent in all the samples, and individuals belonging to two intermediate forms are rather frequent. The hypothesis on the species specificity of the shell valve frontal section has not been confirmed based on examination of large shell samples. The pearl mussels inhabiting rivers of Northern Europe belong to a single species, M. margaritifera. 相似文献
57.
Alexander V. Kachur Anatoliy V. Popov Joel S. Karp E. James Delikatny 《Cell biochemistry and biophysics》2013,66(1):1-5
We report a reaction of direct electrophilic fluorination of phenolsulfonphthalein at mild conditions. This reaction affords the synthesis of novel positron-emitting 18F-labeled pH indicators. These compounds are useful for non-invasive in vivo pH measurement in biological objects. 相似文献
58.
D. V. Popov R. A. Zinovkin E. M. Karger O. S. Tarasova O. L. Vinogradova 《Human physiology》2013,39(2):190-195
It is well recognized that PGC-1α protein is a key regulator of mitochondrial biogenesis. Mechanical and metabolic perturbations in a skeletal muscle during and after aerobic exercise lead to an increased expression of PGC-1α gene. This increased expression of PGC-1α gene after exercise depends on the relative workload intensity and does not depend on the fitness level. The goal of this study was to compare mRNA expression of PGC-1α, TFAM, and TFB2M regulators of mitochondrial biogenesis and FOXO1 and Atrogin-1 proteolysis-related genes in a skeletal muscle of untrained and trained men after aerobic exercise with the same relative workload. This study showed that PGC-1α gene expression after exercise was the same in the two groups, but the expression of TFAM and TFB2M genes was higher in untrained muscles than in trained ones. In contrast, the expression of FOXO1 and Atrogin-1 genes increased only in the muscles of trained men. 相似文献
59.
A. M. Popov A. N. Osipov E. A. Korepanova O. N. Krivoshapko A. A. Artyukov 《Biophysics》2013,58(5):607-615
Rosmarinic acid is found in many species of different families of higher plants and its chemical structure is phenol propanoid with various biological activity. In this paper, we conducted a comparative study of antioxidant (radical-scavenging) properties of rosmarinic acid in systems of 2,2tāzo-bis(2-methylpropionamidin)dihydrochloride-luminol and hemoglobin-hydrogen peroxide-luminol, determined its protective potential in preventing peroxidation of linoleic acid, and evaluated the effect on the permeability of planar bilayer lipid membranes. Linoleic acid peroxidation was assessed by iron-thiocyanate method. In these studies, trolox was used as a reference antioxidant, and ascorbic acid, and dihydroquercetin were taken as standards. Rosmarinic acid is significantly superior to trolox, ascorbic acid and dihydroquercetin in the tests for antioxidant activity in the systems studied, as well as in inhibition of linoleic acid peroxidation. According to their activity the investigated substances can be arranged in the following order: rosmarinic acid > dihydroquercetin trolox > ascorbic acid. Rosmarinic acid does not cause significant changes in the permeability of planar bilayer membranes in a dose range of 0.5 to 10 μg/mL. Antioxidant activity of rosmarinic acid is due to the neutralization of reactive oxygen species and/or luminol radicals generated in model systems. The observed features of the antioxidant and membrane activity of rosmarinic acid, which may underlie the previously mentioned pharmacological effects are discussed. 相似文献
60.
Myung-Chul Chung Aarthi Narayanan Taissia G. Popova Fatah Kashanchi Charles L. Bailey Serguei G. Popov 《Biochemical and biophysical research communications》2013,430(1):125-130
Bacillus anthracis, a causative agent of anthrax, is able to germinate and survive within macrophages. A recent study suggested that B. anthracis-derived nitric oxide (bNO) is a key aspect of bacterial defense that protects bacterial DNA from oxidative burst in the macrophages. However, the virulent effect of bNO in host cells has not been investigated. Here, we report that bNO contributes macrophage killing by S-nitrosylation of bioenergetic-relating proteins within mitochondria. Toxigenic Sterne induces expression of the bnos gene and produces bNO during early stage of infection. Nitroso-proteomic analysis coupled with a biotin-switch technique demonstrated that toxigenic infection induces protein S-nitrosylation in B. anthracis-susceptible RAW264.7. For each target enzyme tested (complex I, complex III and complex IV), infection by B. anthracis Sterne caused enzyme inhibition. Nω-nitro-l-arginine methyl ester, a NO synthase inhibitor, reduced S-nitrosylation and partially restored cell viability evaluated by intracellular ATP levels in macrophages. Our data suggest that bNO leads to energy depletion driven by impaired mitochondrial bioenergetic machinery that ultimately contributes to macrophage death. This novel mechanism of anthrax pathogenesis may offer specific approach to the development of therapeutics. 相似文献