全文获取类型
收费全文 | 114篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
系统科学 | 3篇 |
现状及发展 | 32篇 |
研究方法 | 32篇 |
综合类 | 47篇 |
自然研究 | 3篇 |
出版年
2018年 | 1篇 |
2016年 | 1篇 |
2014年 | 4篇 |
2013年 | 1篇 |
2012年 | 4篇 |
2011年 | 14篇 |
2010年 | 7篇 |
2008年 | 12篇 |
2007年 | 8篇 |
2006年 | 12篇 |
2005年 | 7篇 |
2004年 | 6篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2000年 | 2篇 |
1999年 | 1篇 |
1982年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1970年 | 2篇 |
1968年 | 1篇 |
1967年 | 2篇 |
1966年 | 2篇 |
1964年 | 1篇 |
1962年 | 1篇 |
1961年 | 1篇 |
1960年 | 1篇 |
排序方式: 共有117条查询结果,搜索用时 218 毫秒
1.
Rodney G.Downey ;Judith Egan ;Michael R.Fellows ;Frances A.Rosamond ;Peter Shaw 《清华大学学报》2014,(4):329-337
The main purpose of this paper is to exposit two very different, but very general, motivational schemes in the art of parameterization and a concrete example connecting them. We introduce a dynamic version of the DOMINATING SET problem and prove that it is fixed-parameter tractable(FPT). The problem is motivated by settings where problem instances evolve. It also arises in the quest to improve a natural greedy heuristic for the DOMINATING SET problem. 相似文献
2.
PNPLA1 mutations cause autosomal recessive congenital ichthyosis in golden retriever dogs and humans
Grall A Guaguère E Planchais S Grond S Bourrat E Hausser I Hitte C Le Gallo M Derbois C Kim GJ Lagoutte L Degorce-Rubiales F Radner FP Thomas A Küry S Bensignor E Fontaine J Pin D Zimmermann R Zechner R Lathrop M Galibert F André C Fischer J 《Nature genetics》2012,44(2):140-147
Ichthyoses comprise a heterogeneous group of genodermatoses characterized by abnormal desquamation over the whole body, for which the genetic causes of several human forms remain unknown. We used a spontaneous dog model in the golden retriever breed, which is affected by a lamellar ichthyosis resembling human autosomal recessive congenital ichthyoses (ARCI), to carry out a genome-wide association study. We identified a homozygous insertion-deletion (indel) mutation in PNPLA1 that leads to a premature stop codon in all affected golden retriever dogs. We subsequently found one missense and one nonsense mutation in the catalytic domain of human PNPLA1 in six individuals with ARCI from two families. Further experiments highlighted the importance of PNPLA1 in the formation of the epidermal lipid barrier. This study identifies a new gene involved in human ichthyoses and provides insights into the localization and function of this yet uncharacterized member of the PNPLA protein family. 相似文献
3.
Diatoms epiphytic on Phragmites australis (Cav.) Trin. ex Steaded stems were collected from a single clone at the southern end of Provo Bay, Utah Lake, Utah. Diatom populations from both living and dead stem sections were analyzed. Species diversity in each sample was high, indicating that the stems provide a relatively stable habitat for diatom epiphytes. Of the 23 genera found, only Gomphonema and Navicula showed significant trends toward stem preference. The diatoms in this study support the current view that Utah Lake is a slightly saline, eutrophic system. 相似文献
4.
5.
G. Oster Judith S. Bellin B. Holmström 《Cellular and molecular life sciences : CMLS》1962,18(6):249-253
Résumé Le spectre d'absorption, les caractéristiques luminescentes et photochimiques de la riboflavine sont présentés. L'interprétation des données expérimentales d'autres auteurs sur la décomposition photochimique de l'eau sensibilisée par la riboflavine est critiquée. Il faut distinguer deux cas: dans les réactions photochimiques qui ont lieu en l'absence de donneurs d'électrons ajoutés, la portion ribosique de la riboflavine se comporte en donneuse d'électrons et elle est détruité. Par contre, en présence de donneurs d'électrons adjoutés, la riboflavine agit comme véritable photosensibilisateur et n'est pas consumée dans l'ensemble de la réaction photochimique. 相似文献
6.
7.
Jacqueline Moron Janine Rondest Judith Polonsky 《Cellular and molecular life sciences : CMLS》1966,22(8):511-512
Summary The biosynthesis of glaucarubinone (IXa) and glaucarubolone (IXb), the bitter constituents ofSimarouba glauca (Simaroubaceae), has been investigated with the help of [2-14C] mevalonic acid lactone. The results so far obtained are consistent with the scheme involving a tetracyclic triterpene of the apoeuphol type as a precursor of these bitter substances.
Avec la collaboration technique de Mlle A.Merrien. 相似文献
Avec la collaboration technique de Mlle A.Merrien. 相似文献
8.
Association scan of 14,500 nonsynonymous SNPs in four diseases identifies autoimmunity variants 总被引:2,自引:0,他引:2
Wellcome Trust Case Control Consortium;Australo-Anglo-American Spondylitis Consortium 《Nature genetics》2007,39(11):1329-1337
We have genotyped 14,436 nonsynonymous SNPs (nsSNPs) and 897 major histocompatibility complex (MHC) tag SNPs from 1,000 independent cases of ankylosing spondylitis (AS), autoimmune thyroid disease (AITD), multiple sclerosis (MS) and breast cancer (BC). Comparing these data against a common control dataset derived from 1,500 randomly selected healthy British individuals, we report initial association and independent replication in a North American sample of two new loci related to ankylosing spondylitis, ARTS1 and IL23R, and confirmation of the previously reported association of AITD with TSHR and FCRL3. These findings, enabled in part by increased statistical power resulting from the expansion of the control reference group to include individuals from the other disease groups, highlight notable new possibilities for autoimmune regulation and suggest that IL23R may be a common susceptibility factor for the major 'seronegative' diseases. 相似文献
9.
A. D. Landman L. M. Sanford B. E. Howland C. Dawes E. T. Pritchard 《Cellular and molecular life sciences : CMLS》1976,32(7):940-941
Summary Testosterone has been detected in whole human saliva. Levels averaged (±SE) 295±36 and 195±25 pg/ml in adult males and females, respectively, and usually were undetectable in children. In adult males, the excretion of testosterone in saliva appeared to follow a circadian rhythm.Acknowledgments. This study was supported by grant No. MA-4454 from the Medical Research Council of Canada. The authors wish to thank Mr.D. B. Beaton for excellent technical assistance. 相似文献
10.