全文获取类型
收费全文 | 331篇 |
免费 | 30篇 |
国内免费 | 303篇 |
出版年
2023年 | 8篇 |
2021年 | 12篇 |
2020年 | 2篇 |
2019年 | 5篇 |
2018年 | 15篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 15篇 |
2014年 | 35篇 |
2013年 | 34篇 |
2012年 | 15篇 |
2011年 | 13篇 |
2010年 | 3篇 |
2009年 | 8篇 |
2008年 | 48篇 |
2007年 | 48篇 |
2006年 | 20篇 |
2005年 | 67篇 |
2004年 | 39篇 |
2003年 | 5篇 |
2002年 | 7篇 |
2001年 | 30篇 |
2000年 | 9篇 |
1999年 | 24篇 |
1998年 | 28篇 |
1997年 | 16篇 |
1996年 | 22篇 |
1995年 | 21篇 |
1994年 | 12篇 |
1993年 | 16篇 |
1991年 | 2篇 |
1989年 | 2篇 |
1985年 | 2篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1966年 | 1篇 |
1965年 | 1篇 |
1959年 | 5篇 |
1958年 | 8篇 |
1957年 | 5篇 |
1956年 | 4篇 |
1955年 | 5篇 |
1954年 | 7篇 |
1953年 | 3篇 |
1952年 | 8篇 |
1951年 | 6篇 |
1950年 | 4篇 |
1949年 | 1篇 |
1948年 | 2篇 |
排序方式: 共有664条查询结果,搜索用时 31 毫秒
41.
小鼠基因组研究进展李善如1,2王冬平1陈永福2(1.军事医学科学院实验动物中心,北京100071)(2.中国农业大学生物学院,北京100094)TheDevelopmentofMouseGenomeResearchLIShanru1,2WANGDon... 相似文献
42.
一种简单、经济的植物RNA抽提方法 总被引:3,自引:0,他引:3
孟玲 谭德勇 王焕效 吕朝晖 王晓燕 周翔MENG Ling TAN De-yong WANG Huan-xiao LV Zhao-hui WANG Xiao-yan ZHOU Xiang 《遗传》1998,20(4):28-30
一种简单、经济的植物RNA抽提方法孟玲谭德勇王焕效吕朝晖王晓燕周翔(云南大学生物系,昆明650091)ASimpleEconomicalMethodfortheIsolationofPlantRNAMENGLingTANDeyongWANGHuanx... 相似文献
43.
Yin-ping LU Bao-ju WANG Ji-hua DONG Zhao LIU Shi-he GUAN Meng-ji LU Dong-liang YANG 《Virologica Sinica》2007,22(3):193-198
Guanylate binding protein-1(GBP-1)is an interferon-induced protein.To observe its antiviral effect against Hepatitis B virus(HBV)and Coxsackie virus B3(CVB3),we constructed an eukaryotic expression vector of human GBP-1(hGBP-1).Full-length encoding sequence of hGBP-1 was amplified by long chain RT-PCR and inserted into a pCR2.1 vector,then subcloned into a pCDNA3.1(-)vector.Recombinant hGBP-1 plasmids and pHBV1.3 carrying 1.3-fold genome of HBV were contransfected into HepG2 cells,and inhibition effect of hGBP-1 against HBV replication was observed.Hela cells transfected with recombinant hGBP-1 plasmids were challenged with CVB3,and viral yield in cultures were detected.The results indicated that recombinant eukaryotic expression plasmid of hGBP-1 was constructed successfully and the hGBP-1 gene carried in this plasmid could be efficiently expressed in HepG2 cells and Hela cells.hGBP-1 inhibit CVB3 but not HBV replication in vitro.These results demonstrate that hGBP-1 mediates an antiviral effect against CVB3 but not HBV and perhaps plays an important role in the interferon-mediated antiviral response against CVB3. 相似文献
44.
Xue-mei ZHANG Yan-chun CHE Jing-jing WANG Long-ding LIU Ming-xue XIE Qi-han LI 《Virologica Sinica》2007,22(1):41-45
The genome of a new SV40 strain (SV-IMB) isolated from a rhesus monkey was completely sequenced and compared with other isolates. The results showed that the whole genome contains 5246bp, and the average identity of SV-IMB was 98.1% as compared to other SV40 isolates. Its regulatory region is composed of a complete enhancer and a defective enhancer. Amino acid changes occurred to some extent in both the large T antigen (T-Ag) and VP1 region. The findings demonstrate that the SV-IMB is a new SV40 isolate. 相似文献
45.
Jiang-guo ZHANG Xiao-min QIN Xiao-jing WANG Wei-ming YAN Chuan-long ZHU Xiao-ping LUO Qin NING 《Virologica Sinica》2007,22(5):339-346
To study the contribution of T cell subsets in the pathogenesis of Murine hepatitis virus Type 3(MHV-3) induced chronic viral hepatitis in C3H/Hej mice,ninety C3H/Hej mice were chosen to individually receive 10 plaque forming units(PFU)of MHV-3 intraperitoneally.The changes of virus titer and pathology in liver tissue were examined by standard plaque assay and by the hematoxylin/eosin(HE) staining method from 2 days post MHV-3 infection.The ratios of T cell subsets including CD3 CD4 CD8-,CD3 CD4-CD8 ,CD3 CD4-CD8-,CD3 CD4 CD25 ,CD3 CD4 CD25-and CD3 CD4-CD25 T lymphocyte of total T lymphocytes in blood,spleen and liver were examined at 0,2,4,6,8,10,12,15,20,25,30,40 days post MHV-3 infection by flow cytosorting.We observed that the virus titer raised and showed persistent virus duplications and inflammatory changes in the livers of C3H/Hej mice from 2 days post MHV-3 infection.The double negative T cell(DN Treg cell) and CD4 CD25 T cell ratios increased significantly from 2 days post MHV-3 infection in C3H/Hej mice,and CD3 CD4 CD8-,CD3 CD4-CD8 ,CD3 CD4 CD25-and CD3 CD4-CD25 T cell ratios decreased accordingly.In conclusion,the changes of virus titer and pathology in the livers of C3H/Hej mice post MHV-3 suggest their contribution to viral persistence.Further characterizations of DN Treg cells are that infection indicates that MHV-3 could induce the chronic inflammation in livers of C3H/Hej mice.The increase of the DN Treg cell and CD4 CD25 T cell ratios in C3H/Hej mice post MHV-3 infection suggests that DN Treg cells and CD4 CD25 T cells may both have important suppressive immunomodulation functions in the development of chronic viral hepatitis and have important roles in the virus persistent infection.Further characterizations of DNT cell and CD4 CD25 T cell are under investigation. 相似文献
46.
Gender and genetic strain are two prominent variants that influence drug abuse. Although certain sexrelated behavioral responses have been previously characterized in ICR mice, little is known about the effects of sex on morphine-induced behavioral responses in this outbred strain. Therefore, in this study, we investigated the sex differences of morphine-induced locomotion, anxiety-like and social behaviors in ICR mice. After morphine or saline exposure for four consecutive days(twice daily), increased locomotion, more time spent in the central area, as well as attenuated rearing and self-grooming behaviors were found in morphine-treated females in an open field; no differences were found in locomotion and the time spent in the central area between male and female controls. When interacting with the samesex individuals, female controls were engaged in more social investigation, following, body contacting and self-grooming behaviors than controls; morphine exposure reduced contacting and self-grooming behaviors in females; in contrast, these effects were not found in males. These results indicate that female ICR mice are more prosocial and are more susceptible to morphine exposure than males. 相似文献
47.
48.
Guang-Xuan Tan Zhi-Yong Xiong Hua-Jun Jin Gang Li Li-Li Zhu Li-Hui Shu Guang-Cun He 《植物学报(英文版)》2006,48(9):1077-1083
In the genus Oryza, interspecific hybrids are useful bridges for transferring the desired genes from wild species to cultivated rice (Oryza sativa L.). In the present study, hybrids between O. sativa (AA genome) and three Chinese wild rices, namely O. rufipogon (AA genome), O. officinalis (CC genome), and O. meyeriana (GG genome), were produced. Agricultural traits of the F1 hybrids surveyed were intermediate between their parents and appreciably resembled wild rice parents. Except for the O. sativa × O. rufipogon hybrid, the other F1 hybrids were completely sterile. Genomic in situ hybridization (GISH) was used for hybrid verification. Wild rice genomic DNAs were used as probes and cultivated rice DNA was used as a block. With the exception of O. rufipogon chromosomes, this method distinguished the other two wild rice and cultivated rice chromosomes at the stage of mitotic metaphase with different blocking ratios. The results suggest that a more distant phylogenetic relationship exists between O. meyeriana and O. sativa and that O. rufipogon and O. sativa share a high degree of sequence homology. The average mitotic chromosome length of O. officinalis and O. meyeriana was 1.25- and 1.51-fold that of O. sativa, respectively. 4',6'-Diamidino- 2-phenylindole staining showed that the chromosomes of O. officinalis and O. meyeriana harbored more heterochromatin, suggesting that the C and G genomes were amplified with repetitive sequences compared with the A genome. Although chromocenters formed by chromatin compaction were detected with wild rice-specific signals corresponding to the C and G genomes in discrete domains of the F1 hybrid interphase nuclei, the size and number of O. meyeriana chromocenters were bigger and greater than those of O. officinalis. The present results provide an important understanding of the genomic relationships and a tool for the transfer of useful genes from three native wild rice species in China to cultivars. 相似文献
49.
XIAO-PING WANG FENG GE FANG-SEN XUE 《Insect Science》2006,13(3):189-193
The cabbage beetle, Colaphellus bowringiBaly (Coleoptera: Chrysomelidae), is a serious pest of crucifers in China, undergoing an imaginal summer and winter diapause in the soil. The effects of host plants on diapause incidence were tested in the beetle. The ratio of adults entering diapause was significantly low when they fed on the mature leaves of Chinese cabbage Shanghaiqin (Brassica chinesis var communis) than those feeding on Chinese cabbage Suzhouqin (Brassica chinesis var communis), radish (Raphanus sativus var longipinnatus) and stem mustard (Brassicajuncea vat tumida) at 25℃ combined with 13:11 (L: D) h. Fewer adults entered diapause on young leaves compared to physiologically aged and mature radish leaves at 25℃ combined with 13:11 (L: D) h. The effect of host plant species on diapause induction was also evident under continuously dark rearing conditions or at different photoperiods. These experimental results demonstrate that host plant mediation of diapause induction exists in the cabbage beetle. However, at temperatures ≤20℃ or photoperiods of 16:8 (L: D) h combined with 25℃, all individuals entered diapause regardless of the host plants, indicating that the effects of host plants on diapause induction could be expressed only within a limited range of temperatures and photoperiods. 相似文献
50.
Zhe REN Chuan-hai ZHANG Lian-jun WANG Yun-xia CUI Ren-bin QI Chong-ren YANG Ying-jun ZHANG Xiao-yi WEI Da-xiang LU** Yi-fei WANG ** 《Virologica Sinica》2010,(2)
Herpes simplex virus type 1 (HSV-1) is a commonly occurring human pathogen worldwide. There is an urgent need to discover and develop new alternative agents for the management of HSV-1 infection. Tripterygium hypoglaucum (level) Hutch (Celastraceae) is a traditional Chinese medicine plant with many pharmacological activities such as anti-inflammation, anti-tumor and antifertility. The usual medicinal part is the roots which contain about a 1% yield of alkaloids. A crude total alkaloids extract was prepared ... 相似文献