全文获取类型
收费全文 | 773篇 |
免费 | 62篇 |
出版年
2021年 | 12篇 |
2019年 | 10篇 |
2018年 | 12篇 |
2017年 | 6篇 |
2016年 | 10篇 |
2015年 | 19篇 |
2014年 | 30篇 |
2013年 | 28篇 |
2012年 | 39篇 |
2011年 | 45篇 |
2010年 | 22篇 |
2009年 | 21篇 |
2008年 | 32篇 |
2007年 | 33篇 |
2006年 | 36篇 |
2005年 | 31篇 |
2004年 | 31篇 |
2003年 | 30篇 |
2002年 | 33篇 |
2001年 | 22篇 |
2000年 | 21篇 |
1999年 | 16篇 |
1998年 | 14篇 |
1997年 | 10篇 |
1995年 | 7篇 |
1994年 | 4篇 |
1993年 | 5篇 |
1992年 | 13篇 |
1991年 | 13篇 |
1990年 | 8篇 |
1989年 | 13篇 |
1988年 | 11篇 |
1987年 | 27篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 5篇 |
1982年 | 9篇 |
1981年 | 9篇 |
1980年 | 7篇 |
1979年 | 16篇 |
1978年 | 9篇 |
1977年 | 12篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 6篇 |
1973年 | 6篇 |
1972年 | 5篇 |
1971年 | 10篇 |
1968年 | 5篇 |
排序方式: 共有835条查询结果,搜索用时 15 毫秒
91.
Jean-Malo Couzigou Vladimir Zhukov Samuel Mondy Ghada Abu el Heba Viviane Cosson T.H. Noel Ellis Mike Ambrose Jiangqi Wen Million Tadege Igor Tikhonovich Kirankumar S. Mysore Joanna Putterill Julie Hofer Alexei Y. Borisov Pascal Ratet 《The Plant cell》2012,24(11):4498-4510
During their symbiotic interaction with rhizobia, legume plants develop symbiosis-specific organs on their roots, called nodules, that house nitrogen-fixing bacteria. The molecular mechanisms governing the identity and maintenance of these organs are unknown. Using Medicago truncatula nodule root (noot) mutants and pea (Pisum sativum) cochleata (coch) mutants, which are characterized by the abnormal development of roots from the nodule, we identified the NOOT and COCH genes as being necessary for the robust maintenance of nodule identity throughout the nodule developmental program. NOOT and COCH are Arabidopsis thaliana BLADE-ON-PETIOLE orthologs, and we have shown that their functions in leaf and flower development are conserved in M. truncatula and pea. The identification of these two genes defines a clade in the BTB/POZ-ankyrin domain proteins that shares conserved functions in eudicot organ development and suggests that NOOT and COCH were recruited to repress root identity in the legume symbiotic organ. 相似文献
92.
93.
Aines Castro-Prieto Bettina Wachter Joerg Melzheimer Susanne Thalwitzer Heribert Hofer Simone Sommer 《PloS one》2012,7(11)
Background
Genes under selection provide ecologically important information useful for conservation issues. Major histocompatibility complex (MHC) class I and II genes are essential for the immune defence against pathogens from intracellular (e.g. viruses) and extracellular (e.g. helminths) origins, respectively. Serosurvey studies in Namibian cheetahs (Acinonyx juabuts) revealed higher exposure to viral pathogens in individuals from north-central than east-central regions. Here we examined whether the observed differences in exposure to viruses influence the patterns of genetic variation and differentiation at MHC loci in 88 free-ranging Namibian cheetahs.Methodology/Principal Findings
Genetic variation at MHC I and II loci was assessed through single-stranded conformation polymorphism (SSCP) analysis and sequencing. While the overall allelic diversity did not differ, we observed a high genetic differentiation at MHC class I loci between cheetahs from north-central and east-central Namibia. No such differentiation in MHC class II and neutral markers were found.Conclusions/Significance
Our results suggest that MHC class I variation mirrors the variation in selection pressure imposed by viruses in free-ranging cheetahs across Namibian farmland. This is of high significance for future management and conservation programs of this species. 相似文献94.
Isabella Maiellaro Konstantinos Lefkimmiatis Mary Pat Moyer Silvana Curci Aldebaran M. Hofer 《Journal of cellular and molecular medicine》2012,16(11):2715-2725
Diverse pathophysiological processes (e.g. obesity, lifespan determination, addiction and male fertility) have been linked to the expression of specific isoforms of the adenylyl cyclases (AC1‐AC10), the enzymes that generate cyclic AMP (cAMP). Our laboratory recently discovered a new mode of cAMP production, prominent in certain cell types, that is stimulated by any manoeuvre causing reduction of free [Ca2+] within the lumen of the endoplasmic reticulum (ER) calcium store. Activation of this ‘store‐operated’ pathway requires the ER Ca2+ sensor, STIM1, but the identity of the enzymes responsible for cAMP production and how this process is regulated is unknown. Here, we used sensitive FRET‐based sensors for cAMP in single cells combined with silencing and overexpression approaches to show that store‐operated cAMP production occurred preferentially via the isoform AC3 in NCM460 colonic epithelial cells. Ca2+ entry via the plasma membrane Ca2+ channel, Orai1, suppressed cAMP production, independent of store refilling. These findings are an important first step towards defining the functional significance and to identify the protein composition of this novel Ca2+/cAMP crosstalk system. 相似文献
95.
Kiesewetter S Köpsel A Mai K Stroux A Bobbert T Spranger J Köpp W Deter HC Kallenbach-Dermutz B 《BioPsychoSocial medicine》2012,6(1):3
Background & Aims
The long-term success of life-style interventions in the treatment of obesity is limited. Although psychological factors have been suggested to modify therapeutic effects, specifically the implications of attachment styles and the patient-therapist relationship have not been examined in detail yet. 相似文献96.
97.
98.
T Hofer P Spielmann P Stengel B Stier D M Katschinski I Desbaillets M Gassmann R H Wenger 《Biochemical and biophysical research communications》2001,288(4):757-764
The PAS domain is a versatile protein fold found in many archaeal, bacterial, and plant proteins capable of sensing environmental changes in light intensity, oxygen concentration, and redox potentials. The oxygen sensor FixL from Rhizobium species contains a heme-bearing PAS domain and a histidine kinase domain that couples sensing to signaling. We identified a novel mammalian PAS protein (PASKIN) containing a domain architecture resembling FixL. PASKIN is encoded by an evolutionarily conserved single-copy gene which is ubiquitously expressed. The human PASKIN and mouse Paskin genes show a conserved intron-exon structure and share their promoter regions with another ubiquitously expressed gene that encodes a regulator of protein phosphatase-1. The 144-kDa PASKIN protein contains a PAS region homologous to the FixL PAS domain and a serine/threonine kinase domain which might be involved in signaling. Thus, PASKIN is likely to function as a mammalian PAS sensor protein. 相似文献
99.
100.