全文获取类型
收费全文 | 1095篇 |
免费 | 27篇 |
出版年
2022年 | 7篇 |
2021年 | 14篇 |
2019年 | 15篇 |
2018年 | 18篇 |
2017年 | 18篇 |
2016年 | 27篇 |
2015年 | 14篇 |
2014年 | 26篇 |
2013年 | 28篇 |
2012年 | 40篇 |
2011年 | 47篇 |
2010年 | 38篇 |
2009年 | 25篇 |
2008年 | 45篇 |
2007年 | 38篇 |
2006年 | 37篇 |
2005年 | 42篇 |
2004年 | 46篇 |
2003年 | 47篇 |
2002年 | 57篇 |
2001年 | 29篇 |
2000年 | 36篇 |
1999年 | 27篇 |
1997年 | 7篇 |
1992年 | 17篇 |
1991年 | 28篇 |
1990年 | 21篇 |
1989年 | 24篇 |
1988年 | 21篇 |
1987年 | 12篇 |
1986年 | 18篇 |
1985年 | 15篇 |
1984年 | 13篇 |
1983年 | 18篇 |
1980年 | 6篇 |
1979年 | 12篇 |
1978年 | 11篇 |
1977年 | 7篇 |
1976年 | 11篇 |
1975年 | 14篇 |
1974年 | 13篇 |
1973年 | 15篇 |
1972年 | 12篇 |
1971年 | 12篇 |
1970年 | 9篇 |
1969年 | 8篇 |
1968年 | 11篇 |
1967年 | 8篇 |
1966年 | 12篇 |
1965年 | 14篇 |
排序方式: 共有1122条查询结果,搜索用时 234 毫秒
21.
I I Fomicheva D K Tsertsvadze O Iu Volkova N A Popova S I Smirnykh N A Kisteneva V F KuznetsovKNKudashev Iu D Kaveshnikov 《Genetika》1991,27(5):895-902
110 ranch-raised minks were injected with the Aleutian disease virus. Allotypes of constant regions of gamma-heavy chains of the mink immunoglobulins secreted have been analysed during 3 months. Activation of the expression of two markers (H3 and/or H4) up to minor or to nominal level (above 200 micrograms/ml) was observed. No such enhancement of expression of two other allotypes (H6 and H8) was found. The results suggest that the expression of two mink immunoglobulin CH genes induced by viral infection has allotype-specific regulation. 相似文献
22.
Changes in the polypeptide patterns of barley seedlings exposed to jasmonic Acid and salinity 总被引:2,自引:1,他引:1
Soluble and thylakoid membrane proteins of jasmonic acid (JA)-treated and salt-stressed barley (Hordeum vulgare L.) seedlings were investigated using 15% sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. High JA concentrations induced marked quantitative and qualitative changes in polypeptide profiles concerning mainly the proteins with approximately equal mobility, as in NaCl-stressed plants. The most obvious increase in thylakoid polypeptide band intensity was at 55 to 57 kilodaltons (kD). The relative share of some polypeptides with apparent molecular masses above 66 kD and of polypeptides with lower molecular masses in the region of 20.5 to 15 kD was enhanced. At the same time, one new band at 31 to 31.5 kD was well expressed at 25 and 250 micromolar JA concentrations and became discernible in the 100 micromolar NaCl-treated plants. The intensity of some polypeptides of soluble proteins (molecular masses of 60, 47, 37, 30, and 23.4 kD) increased with increasing JA concentration, whereas the intensities of other polypeptide bands (55, 21.4, and 15 kD) decreased. Enhanced levels of 60-, 47-, 34-, and 30-kD polypeptides and reduced levels of 55- and 15-kD polypeptides were present in NaCl-treated plants. The appearance of one new polypeptide, of 25.1 kD, was observed only in NaCl-treated plants. At 100 millimolar NaCl, an eightfold increase in proline content was observed while at 250 micromolar JA, the proline content was threefold over the control. It is hypothesized that exogenously applied jasmonates act as stress agents. As such, they provoke alterations in the proline content and they can modulate typical stress responses by induction of stress proteins. 相似文献
23.
I I Fomicheva N A Popova D K Tservadze O Iu Volkova T I Kochlashvili O K Baranov 《Genetika》1990,26(1):109-113
IgG polymorphism (allotypes H3, H4, H6 and H8 of constant region of the gamma-chain) was investigated in healthy and affected with Aleutian disease (AD) minks from two Siberian and one Danish populations. In all three populations, the expression of H3 and H4 allotypes was strongly associated with AD. Among the AD minks the frequency of H6, H8 phenotype was found to be decreased, whereas the frequency of H3, H4, H6, H8 phenotype was significantly increased. At the same time, the populational distribution of the rest phenotypes was similar among healthy and AD minks. The H3, H4, H6, H8 minks showed the highest pathomorphological characteristics of AD. Based on the data concerning mink H3 and H4, and human Gm allotypes, their role as possible genetic markers for hereditary susceptibility to distinct disease is discussed. 相似文献
24.
The effect of cAMP on the parameters characterizing the development of luminescence in Photobacterium belozerskii is discussed. An addition of cAMP to the culture medium shortened the latent time of luminescence development by 3--6 hours. The intensity of bacterial luminescence increased with a varying rate. During luminescence enhancement the rate of luciferase synthesis increased by a factor of 10 to 10(3). The rate of luciferase synthesis and the maxiumum level of bacterial luminescence when cultivated in the glycerol medium containing arginine and proline increased under the influence of cAMP by 100 and 40 times, respectively. After an addition to cAMP into the glucose medium these parameters of luminescence development increased only when the medium contained arginine. After an addition of cAMP into the glycerol medium the rate of bacterial growth increased two-fold. Possible mechanisms regulating luminescence development and cAMP involvement in these processes are discussed. 相似文献
25.
Yu. I. Arshavskii M. B. Berkinblit L. B. Popova O. I. Fukson V. S. Yakobson 《Neurophysiology》1979,11(6):438-444
The effect of the central analgesic fentanyl on evoked potentials and responses of single Purkinje cells in the cerebellar cortex to stimulation of the sensomotor cortex and of somatic nerves was investigated in unanesthetized cats. Injection of fentanyl in an analgesic dose (10–30 µg/kg, intravenously) had no appreciable effect on evoked potentials and led only to very slight changes in spontaneous activity and responses of Purkinje cells. As a rule fentanyl, in a dose of 30 µg/kg, depressed, but in a dose of 10 µg/kg, facilitated responses and spontaneous activity of Purkinje cells. This effect of fentanyl is negligible compared with the action of barbiturate anesthetics on responses of cerebellar cortical neurons. Consequently, fentanyl can be used for analgesia during electrophysiological investigations of the cerebellar cortex in unanesthetized cats.Institute for Problems in Information Transmission, Academy of Sciences of the USSR, Moscow. M. V. Lomonosov Moscow State University. Translated from Neirofiziologiya, Vol. 11, No. 6, pp. 585–592, November–December, 1979. 相似文献
26.
27.
A V Nikitin L N Makarovskaia I P Fomina L P Ivanitskaia G O Popova N N Vinidchenko Ia N Korganov L E Bodunkova 《Antibiotiki i khimioterapii͡a》1991,36(5):23-25
The combined effect of rifampicin and a microbial peptidoglycan was studied in multifactorial experiments on noninbred mice with plague infection. The effect of rifampicin and the immunomodulator was shown to be synergistic. The results of the multifactorial experiments provided designing of polynomial statistic models of the second order characterizing the animal survival rate and mean life-span and plotting of nomograms or equal level lines useful in optimization of the combined therapy parameters. 相似文献
28.
V V Revin S A Kasatkin G N Cherkasova V T Nikolaev N S Iamashkina M N Chabushkina O A Popova V F Belianina 《Antibiotiki i khimioterapii͡a》1991,36(1):5-8
Influence of the quality of the fats used on their utilization in the process of cephalosporin C fermentation and accumulation was studied. A decrease in the level of all the fractions of the fatty acids was observed during the fermentation process. The antibiotic yield with the use of oxidized fats was lower. Treatment of the fats with gaseous nitrogen prevented their oxidation. It was supposed that the decreased yields of the antibiotic were associated with the influence of the oxidized fats on the biosynthetic processes. 相似文献
29.
L T Kushashvili A K Zhuravlev A G Borodkin G V Popova A D Nekliudov 《Antibiotiki i khimioterapii͡a》1988,33(1):16-22
The process of asymmetric deacylation of an acetyl derivative of 5-benzyl hydroxytryptophan racemate in the presence of native microbial aminoacylase was studied. The effect of pH, temperature, concentration of the enzyme and substrate were investigated. Conditions for preparation and isolation of individual amino acids were defined by optimization of N-Ac-DU-5-BOT hydrolysis. 相似文献
30.
V M Gagarinova E B Chepik E P Korneeva O M Litvinova T I Orlova N B Rumel' A K Golovanova M M Shvager T L Popova E A Smorodintseva 《Zhurnal mikrobiologii, epidemiologii, i immunobiologii》1990,(12):34-37
In the summer of 1986 the epidemic, whose etiological agents were influenza viruses A (H1N1) and respiratory syncytial virus, was registered among the population of Novoshakhtinsk. In a number of mines 15.3-16.7% of the employees were affected. Influenza viruses A (H1N1) proved to be closely related in their antigenic and biological properties to viruses isolated in the USSR in March-June 1986, as well as to viruses A (H1N1), the etiological agents of the epidemic which developed in the USSR in October-December 1986. 相似文献