全文获取类型
收费全文 | 654篇 |
免费 | 46篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 14篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 8篇 |
2017年 | 9篇 |
2016年 | 16篇 |
2015年 | 24篇 |
2014年 | 28篇 |
2013年 | 30篇 |
2012年 | 39篇 |
2011年 | 51篇 |
2010年 | 36篇 |
2009年 | 35篇 |
2008年 | 46篇 |
2007年 | 34篇 |
2006年 | 39篇 |
2005年 | 45篇 |
2004年 | 46篇 |
2003年 | 30篇 |
2002年 | 37篇 |
2001年 | 7篇 |
2000年 | 5篇 |
1999年 | 4篇 |
1998年 | 5篇 |
1997年 | 5篇 |
1996年 | 9篇 |
1995年 | 4篇 |
1994年 | 4篇 |
1993年 | 9篇 |
1992年 | 4篇 |
1990年 | 4篇 |
1986年 | 5篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 7篇 |
1980年 | 6篇 |
1979年 | 4篇 |
1978年 | 3篇 |
1977年 | 2篇 |
1976年 | 6篇 |
1975年 | 3篇 |
1972年 | 1篇 |
1971年 | 1篇 |
1969年 | 1篇 |
1963年 | 1篇 |
1957年 | 1篇 |
排序方式: 共有700条查询结果,搜索用时 31 毫秒
191.
Identification of RNA editing sites in the SNP database 总被引:3,自引:0,他引:3
Eisenberg E Adamsky K Cohen L Amariglio N Hirshberg A Rechavi G Levanon EY 《Nucleic acids research》2005,33(14):4612-4617
The relationship between human inherited genomic variations and phenotypic differences has been the focus of much research effort in recent years. These studies benefit from millions of single-nucleotide polymorphism (SNP) records available in public databases, such as dbSNP. The importance of identifying false dbSNP records increases with the growing role played by SNPs in linkage analysis for disease traits. In particular, the emerging understanding of the abundance of DNA and RNA editing calls for a careful distinction between inherited SNPs and somatic DNA and RNA modifications. In order to demonstrate that some of the SNP database records are actually somatic modification, we focus on one type of these modifications, namely A-to-I RNA editing, and present evidence for hundreds of dbSNP records that are actually editing sites. We provide a list of 102 RNA editing sites previously annotated in dbSNP database as SNPs, and experimentally validate seven of these. Interestingly, we show how dbSNP can serve as a starting point to look for new editing sites. Our results, for this particular type of RNA editing, demonstrate the need for a careful analysis of SNP databases in light of the increasing recognition of the significance of somatic sequence modifications. 相似文献
192.
Bester E Wolfaardt G Joubert L Garny K Saftic S 《Applied and environmental microbiology》2005,71(12):7792-7798
Biofilm cells differ phenotypically from their free-floating counterparts. Differential growth rates in biofilms are often referred to, particularly in response to limited diffusion of oxygen and nutrients. We observed growth rates of attached Pseudomonas sp. strain CT07 cells that were notably higher than the maximum specific growth rate measured in batch culture. Despite dilution rates in continuous flow cells that exceeded the maximum planktonic specific growth rate by 58 times, sampling of the effluent revealed >10(9) cells ml(-1), suggesting that biofilms function as a source of planktonic cells through high cell yield and detachment. Further investigation demonstrated considerable planktonic cell yield from biofilms as young as 6 h, indicating that detachment is not limited to established biofilms. These biofilm-detached cells were more sensitive to a commercial biocide than associated biofilm- and chemostat-cultivated populations, implying that detached biofilm cells exhibit a character that is distinct from that of attached and planktonic cell populations. 相似文献
193.
Glucosamine 6-phosphate is converted to fructose 6-phosphate and ammonia by the action of the enzyme glucosamine 6-phosphate deaminase, NagB. This reaction is the final step in the specific GlcNAc utilization pathway and thus decides the metabolic fate of GlcNAc. Sequence analyses suggest that the NagB "superfamily" consists of three main clusters: multimeric and allosterically regulated glucosamine-6-phosphate deaminases (exemplified by Escherichia coli NagB), phosphogluconolactonases, and monomeric hexosamine-6-phosphate deaminases. Here we present the three-dimensional structure and kinetics of the first member of this latter group, the glucosamine-6-phosphate deaminase, NagB, from Bacillus subtilis. The structures were determined in ligand-complexed forms at resolutions around 1.4 Angstroms. BsuNagB is monomeric in solution and as a consequence is active (k(cat) 28 s(-1), K(m(app)) 0.13 mM) without the need for allosteric activators. A decrease in activity at high substrate concentrations may reflect substrate inhibition (with K(i) of approximately 4 mM). The structure completes the NagB superfamily structural landscape and thus allows further interrogation of genomic data in terms of the regulation of NagB and the metabolic fate(s) of glucosamine 6-phosphate. 相似文献
194.
CLASP1 and CLASP2 bind to EB1 and regulate microtubule plus-end dynamics at the cell cortex 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《The Journal of cell biology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Mimori-Kiyosue Y Grigoriev I Lansbergen G Sasaki H Matsui C Severin F Galjart N Grosveld F Vorobjev I Tsukita S Akhmanova A 《The Journal of cell biology》2005,168(1):141-153
CLIP-associating protein (CLASP) 1 and CLASP2 are mammalian microtubule (MT) plus-end binding proteins, which associate with CLIP-170 and CLIP-115. Using RNA interference in HeLa cells, we show that the two CLASPs play redundant roles in regulating the density, length distribution and stability of interphase MTs. In HeLa cells, both CLASPs concentrate on the distal MT ends in a narrow region at the cell margin. CLASPs stabilize MTs by promoting pauses and restricting MT growth and shortening episodes to this peripheral cell region. We demonstrate that the middle part of CLASPs binds directly to EB1 and to MTs. Furthermore, we show that the association of CLASP2 with the cell cortex is MT independent and relies on its COOH-terminal domain. Both EB1- and cortex-binding domains of CLASP are required to promote MT stability. We propose that CLASPs can mediate interactions between MT plus ends and the cell cortex and act as local rescue factors, possibly through forming a complex with EB1 at MT tips. 相似文献
195.
Boskovic R Rudic N Danieliewska-Nikiel B Navioz Y Koren G 《Birth defects research. Part A, Clinical and molecular teratology》2004,70(8):528-530
BACKGROUND: Case-control studies have suggested that the nausea and vomiting of pregnancy (NVP) may have a protective effect against specific malformations. These suggestions have been interpreted as if the lack of NVP may put mothers at an increased teratogenic risk. METHODS: A prospective, cohort-controlled study was done comparing pregnancy outcome in women not experiencing NVP with those experiencing NVP at two levels of clinical severity. Women who called the Motherisk program about first-trimester exposure to drugs and who had not experienced NVP were included as the study group. The NVP Healthline enrolled two control groups of women with NVP treated with a doxylamine-pyridoxine combination for morning sickness. These women were exposed during the first trimester of gestation to either higher than the standard dose (5-12 tablets/day) or a standard dose (1-4 tablets/day) of doxylamine-pyridoxine. The women in all three groups were followed up four to six months after the expected date of birth to ascertain pregnancy outcomes and child health. RESULTS: There were no major malformations among offspring of 130 women not experiencing NVP. There were two major malformations among 246 women experiencing NVP. The two control groups of women with NVP had similar distributions of gestational ages, birth rates, as well as rates of miscarriages and stillbirths, as in the no-NVP group. CONCLUSIONS: This study did not show an association between lack of NVP and an increase in the overall rates of major malformations. 相似文献
196.
197.
Gideon A. Erkenswick Mrinalini Watsa Alfonso S. Gozalo Shay Dudaie Lindsey Bailey Kudakwashe S. Muranda Alaa Kuziez Patricia G. Parker 《American journal of primatology》2019,81(12)
The establishment of baseline data on parasites from wild primates is essential to understand how changes in habitat or climatic disturbances will impact parasite–host relationships. In nature, multiparasitic infections of primates usually fluctuate temporally and seasonally, implying that the acquisition of reliable data must occur over time. Individual parasite infection data from two wild populations of New World primates, the saddleback (Leontocebus weddelli) and emperor (Saguinus imperator) tamarin, were collected over 3 years to establish baseline levels of helminth prevalence and parasite species richness (PSR). Secondarily, we explored variation in parasite prevalence across age and sex classes, test nonrandom associations of parasite co‐occurrence, and assess the relationship between group size and PSR. From 288 fecal samples across 105 individuals (71 saddleback and 34 emperor tamarins), 10 parasite taxa were identified by light microscopy following centrifugation and ethyl‐acetate sedimentation. Of these taxa, none were host‐specific, Dicrocoeliidae and Cestoda prevalences differed between host species, Prosthenorchis and Strongylida were the most prevalent. Host age was positively associated with Prosthenorchis ova and filariform larva, but negatively with cestode and the Rhabditoidea ova. We detected no differences between expected and observed levels of co‐infection, nor between group size and parasite species richness over 30 group‐years. Logistic models of individual infection status did not identify a sex bias; however, age and species predicted the presence of four and three parasite taxa, respectively, with saddleback tamarins exhibiting higher PSR. Now that we have reliable baseline data for future monitoring of these populations, next steps involve the molecular characterization of these parasites, and exploration of linkages with health parameters. 相似文献
198.
199.
200.
Vivek Jain Wei Chang Dathan M. Byonanebye Asiphas Owaraganise Ellon Twinomuhwezi Gideon Amanyire Douglas Black Elliot Marseille Moses R. Kamya Diane V. Havlir James G. Kahn 《PloS one》2015,10(12)