全文获取类型
收费全文 | 283篇 |
免费 | 22篇 |
国内免费 | 38篇 |
出版年
2012年 | 24篇 |
2011年 | 29篇 |
2010年 | 7篇 |
2009年 | 8篇 |
2008年 | 28篇 |
2007年 | 21篇 |
2006年 | 19篇 |
2005年 | 18篇 |
2004年 | 10篇 |
2003年 | 13篇 |
2002年 | 15篇 |
2001年 | 13篇 |
2000年 | 13篇 |
1999年 | 3篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 4篇 |
1994年 | 2篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1984年 | 1篇 |
1980年 | 1篇 |
1978年 | 2篇 |
1973年 | 1篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1967年 | 2篇 |
1966年 | 1篇 |
1963年 | 1篇 |
1960年 | 1篇 |
1959年 | 3篇 |
1958年 | 9篇 |
1957年 | 7篇 |
1956年 | 6篇 |
1955年 | 6篇 |
1954年 | 6篇 |
1953年 | 12篇 |
1952年 | 5篇 |
1951年 | 3篇 |
1950年 | 4篇 |
1949年 | 7篇 |
1948年 | 9篇 |
1946年 | 1篇 |
1945年 | 1篇 |
1943年 | 1篇 |
排序方式: 共有343条查询结果,搜索用时 15 毫秒
1.
2.
3.
MethodsforHandy,RapidIsolationofHighQualityRNAbyGuanadiumThioeyauateDuJianYuanYanhuaMaShenglinDongZhiwei(BeijingInstituteforCancerResearchBeijing100034)硫氰胍是一种有效的蛋白变性剂。早在1979年,Chirgwin等就利用氯化铯/硫氰胍超离心技术成功地从RNA酶富集的胰脏组织中提取出未降解的RNA分子[2],从而使它成为抑制RNA酶的首选药物并得到广泛使用,但受到超速离心设备的限制。1983年,Cathala报道了氯化锂/硫氰胍RNA提取法[1]。该方法操作简便,获得的RNA质量很高,但所需时间较长。为了能在短时间内更快… 相似文献
4.
保证项目审议的公正性是自然科学基金工作的生命线,也是国家自然科学基金委员会取得各学术机构和科学家们信任的根基。国家自然科学基金委员会自成立以来,坚持“依靠专家,发扬民主,择优资助,公正合理”的十六字方针,在各个运行环节上采取了一系列措施,力图在基金项目的审议方面做到公正合理。将这些措施介绍给大家,可以作为引玉之砖,更广泛地吸取专家们的意见,以期在这方面做得更好。 相似文献
5.
6.
7.
宋光江 李桂信 李启清 孙安堂 宋兴军 杜克明 刘京升SONG Guang-Jiang LI Gui-Xin LI Qi-Qing SUN An-Tang SONG Xing-Jun DU Ke-Ming LIU Jiang-Sheng 《遗传》1995,17(4):1-3
CT所见肝脏肿大占据左右上腹,纠正了既往把肝左叶当做脾大的结论;B超发现前所没有报道的二尖瓣赘生物将给患者终生致残;标准品DS行双向电泳,首次发现其分离为DS1与GS2两个斑点;杂合子、患者尿GAG均出现DS1斑点,而正常人则不出现。实验显示,DS1的出现在杂合子检出和患者确诊上有重要意义。 相似文献
8.
NICOLAS HARMEL RAKI ALMOHAMAD MARIE-LAURE FAUCONNIER PATRICK DU JARDIN FRANCOIS VERHEGGEN MICHEL MARLIER ERIC HAUBRUGE FREDERIC FRANCIS 《Insect Science》2007,14(1):57-63
To cope with pathogen and insect attacks, plants develop different mechanisms of defence, in both direct (physical and chemical) and indirect ways (attractive volatiles to entomophagous beneficials). Plants are then able to express traits that facilitate "top-down" control of pests by attracting herbivore predators. Here we investigate the indirect defence mechanism of potato plants by analyzing the volatile patterns of both healthy and aphid- infested plants. Important changes in the emitted terpene pattern by the Myzus persicae infested host plant were observed. Using Solid Phase MicroExtraction (SPME) and GC-MS, the (E)-fl-farnesene (EBF) appeared to be emitted by aphid-infested potato and not by healthy plants. To assess the infochemical role of these volatile releases after aphid damage on the aphidophagous predators Episyrphus balteams, the hoverfly foraging behavior was assessed using the Observer 5.0 software (Noldus, Wageningen, The Netherlands). Aphidfree potato plants were also used as a control volatile source in the predator behavioral study. While aphid-infested plants induced efficient searching and acceptation behaviors leading to egg-laying, no kairomonal effect of healthy potato plants was observed, leading to longer immobility durations and shorter searching periods in the net cage. High oviposition rate of E. balteatus was observed when aphid-infested potato was used (mean of 48.9 eggs per laying and per female). On the other hand, no egg was produced by the hoverfly on healthy aphid-free plants. The E. balteatus foraging and reproductive behaviors according to the volatile emission from aphid-infested plants are discussed in relation to the potential use of active infochemical molecules in integrated aphid pest management. 相似文献
9.
Won M Park SK Hoe KL Jang YJ Chung KS Kim DU Kim HB Yoo HS 《Biochemical and biophysical research communications》2001,282(1):10-15
The Rkp1/Cpc2, a fission yeast RACK1 homolog, interacted with Pck2, one of the known PKC homologs, in vivo and in vitro. The rkp1-deletion mutants (Deltarkp1) are elongated and the pck2-deletion mutant (Deltapck2) showed abnormal morphology. The double-deletion mutant (Deltarkp1Deltapck2) showed more aberrant cell shapes and was sensitive to high salt concentration. Both Deltarkp1 and Deltapck2 cells were sensitive to latrunculin B (Lat B) which inhibits actin polymerization. The cells expressing the human RACK1 homolog complemented the latrunculin B sensitivity of Deltarkp1 indicating that human RACK1 is a functional homolog of Rkp1/Cpc2. We propose that Rkp1/Cpc2 may function as a receptor for Pck2 in the regulation of actin cytoskeleton organization during cell wall synthesis and morphogenesis of Schizosaccharomyces pombe. 相似文献
10.
Kim DU Roh TY Lee J Noh JY Jang YJ Hoe KL Yoo HS Choi MU 《Biochimica et biophysica acta》1999,1437(3):409-414
We cloned and expressed a full-length cDNA encoding a phospholipase D of type alpha (PLDalpha) from cabbage. Analysis of the cDNA predicted an 812-amino-acid protein of 92.0 kDa. The deduced amino acid sequence of cabbage PLD has 83% and 80% identity with Arabidopsis PLDalpha and castor bean PLD, respectively. Expression of this cDNA clone in E. coli shows a functional PLD activity similar to that of the natural PLD. 相似文献