全文获取类型
收费全文 | 388篇 |
免费 | 5篇 |
专业分类
393篇 |
出版年
2021年 | 4篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 5篇 |
2014年 | 9篇 |
2013年 | 17篇 |
2012年 | 11篇 |
2011年 | 10篇 |
2010年 | 13篇 |
2009年 | 8篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 14篇 |
2005年 | 12篇 |
2004年 | 11篇 |
2003年 | 5篇 |
2002年 | 15篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 10篇 |
1998年 | 4篇 |
1997年 | 10篇 |
1996年 | 3篇 |
1993年 | 5篇 |
1992年 | 9篇 |
1991年 | 5篇 |
1990年 | 18篇 |
1989年 | 15篇 |
1988年 | 17篇 |
1987年 | 10篇 |
1986年 | 7篇 |
1985年 | 10篇 |
1984年 | 4篇 |
1983年 | 7篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 5篇 |
1974年 | 3篇 |
1973年 | 6篇 |
1972年 | 6篇 |
1971年 | 2篇 |
1970年 | 4篇 |
1969年 | 6篇 |
1968年 | 9篇 |
1967年 | 9篇 |
1965年 | 3篇 |
排序方式: 共有393条查询结果,搜索用时 0 毫秒
1.
N V Guliaeva O L Levina I P Levina 《Biulleten' eksperimental'no? biologii i meditsiny》1985,100(8):204-206
Male albino rats were exposed to daily emotional painful stress (EPS) for 4 weeks. The arterial blood pressure of the stressed animals increased and the dynamics of the heart rate changed after functional loading (hypokinesis during one or two hours) as compared with the control group. The increase of the heart weight and activation of cytochrome oxidase activity in the cerebral cortex and hippocampus of rats exposed to EPS were also demonstrated. The use of 20% ethyl alcohol instead of drinking water during EPS partially prevented vegetative disturbances and activation of hippocampal cytochrome oxidase and fully prevented the heart hypertrophy and activation of the enzyme in the cortex. Alcoholization resulted in the increased weight of the spleen and brown adipose tissue and thymus involution. A possible mechanism of the antistress action of alcohol linked with normalization of intensified lipid peroxidation under stress is discussed. 相似文献
2.
V. P. Shevchenko I. Yu. Nagaev I. S. Levina L. E. Kulikova N. F. Myasoedov A. V. Kamernitzky 《Russian Journal of Bioorganic Chemistry》2010,36(2):263-268
1,2-Tritium-labeled 3-(O-carboxypropyl)- and 3-(O-carbomethoxypropyl)-oximes of 6α-methyl-16α,17α-cyclohexanopregn-4-ene-3,20-diones were obtained by the homogeneous catalytic
hydrogenation of 1,2-dehydroprecursors with gaseous tritium and the subsequent separation of the resulting mixtures by HPLC.
The specific radioactivities of 50–55 Ci/mmol were prepared using tris-(triphenylphosphine)-rhodium chloride. 相似文献
3.
M. N. Repkova A. S. Levina A. A. Seryapina N. V. Shikina E. V. Bessudnova V. F. Zarytova A. L. Markel 《Biochemistry. Biokhimii?a》2017,82(4):454-457
TiO2-based nanocomposites were prepared to deliver oligonucleotides into cells. The nanocomposites were designed by the immobilization of polylysine-containing oligonucleotides on TiO2-nanoparticles (TiO2·PL-DNA). We showed for the first time the possibility of using the proposed nanocomposites for treatment of hypertensive disease by introducing them into hypertensive ISIAH rats developed as a model of stress-sensitive arterial hypertension. The mRNA of the gene encoding angiotensin I-converting enzyme (ACE1) involved in the synthesis of angiotensin II was chosen as a target. Administration (intraperitoneal injection and inhalation) of the nanocomposite showed a significant (by 20-30 mm Hg) decrease in systolic blood pressure when the nanocomposite contained the ACE1 gene-targeted oligonucleotide. When using the oligonucleotide with a random sequence, no effect was observed. Further development and improvement of the inhalation nanocomposite drug delivery to systemic hypertensive disease treatment promises new possibilities for clinical practice. 相似文献
4.
Summary Variable selection for clustering is an important and challenging problem in high‐dimensional data analysis. Existing variable selection methods for model‐based clustering select informative variables in a “one‐in‐all‐out” manner; that is, a variable is selected if at least one pair of clusters is separable by this variable and removed if it cannot separate any of the clusters. In many applications, however, it is of interest to further establish exactly which clusters are separable by each informative variable. To address this question, we propose a pairwise variable selection method for high‐dimensional model‐based clustering. The method is based on a new pairwise penalty. Results on simulated and real data show that the new method performs better than alternative approaches that use ?1 and ?∞ penalties and offers better interpretation. 相似文献
5.
Annenkov VV Levina AS Danilovtseva EN Filina EA Mikhaleva EA Zarytova VF 《Bioorganicheskaia khimiia》2006,32(5):511-519
A new type of coating for manufacturing DNA chips was constructed of the basis of an organic-inorganic nanocomposite based on the polyvinylbutyral-tetraethoxysilane copolymer. The organosilicon composite was functionalized by introduction of ethanolamine vinyl ether copolymers, which contain amino groups and anchor vinyloxide units capable of reacting with silanol groups of the nanocomposite. The resulting coatings form a film on glass slides with a high surface density of amino groups (up to 700 groups/nm2) suitable for three-dimensional immobilization of oligonucleotides. The use of bifunctional reagents (e.g., phenylene diisothiocyanate) for the attachment of oligonucleotides bearing amino linkers to the amino-containing surface provides an immobilization density of 0.5-1.6 pmol/mm2. Immobilization with a higher density (10-12 pmol/mm2) was achieved for attachment to amino-containing glass slides upon the use of oligonucleotides containing selectively activated terminal phosphate groups. The activation of oligonucleotides was carried out with the triphenylphosphine-dithiodipyridine pair in the presence of dimethylaminopyridine N-oxide. The resulting DNA chips were shown to be useful in principle for DNA detection. 相似文献
6.
Korolenko TA Levina OA Falameeva OV Tolochko ZS Spiridonov VK Andreeva EM Il'nitskaia SI Kaledin VI 《Rossi?skii fiziologicheski? zhurnal imeni I.M. Sechenova / Rossi?skaia akademiia nauk》2003,89(4):420-426
Serpin alpha-1-proteinase inhibitor have been studied in human subjects and in mice of different lines as acute phase reactant and during tumor development. In humans, there was no difference of serpin activity between men and women. Increased activity was noted in men with acute trauma (acute phase reaction). Comparatively to male, in female mice of different lines decreased activity of serum alpha-1-proteinase inhibitor, was shown. There was no increase of alpha-1-proteinase inhibitor activity during inflammation induced by zymosan administration in mice. alpha-1-proteinase inhibitor belongs to acute phase reactants in humans but not in mice; for mice alpha-2-macroglobulin is a more typical acute phase reactant as compared to alpha-1-proteinase inhibitor. Murine tumor development (hepatoma HA-1, lymphosarcoma LS, Lewis lung adenocarcinoma) was followed by a decreased activity of serum alpha-1-proteinase inhibitor both in successfully treated and untreated groups. According to data of literature, similar dated were obtained in humans with tumors. It was suggested that changes of expressiln of alpha-1-proteinase inhibitor by tumors and its secretion were involved in decreased activity of alpha-1-proteinase inhibitor. 相似文献
7.
8.
9.
10.