全文获取类型
收费全文 | 214篇 |
免费 | 15篇 |
国内免费 | 2篇 |
出版年
2022年 | 2篇 |
2021年 | 4篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 3篇 |
2017年 | 7篇 |
2016年 | 3篇 |
2015年 | 6篇 |
2014年 | 9篇 |
2013年 | 14篇 |
2012年 | 16篇 |
2011年 | 11篇 |
2010年 | 17篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 6篇 |
2006年 | 11篇 |
2005年 | 12篇 |
2004年 | 5篇 |
2003年 | 2篇 |
2002年 | 9篇 |
2001年 | 2篇 |
2000年 | 6篇 |
1999年 | 4篇 |
1998年 | 7篇 |
1997年 | 7篇 |
1996年 | 6篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1992年 | 3篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1988年 | 4篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1975年 | 1篇 |
1973年 | 2篇 |
1972年 | 3篇 |
1969年 | 3篇 |
1965年 | 2篇 |
排序方式: 共有231条查询结果,搜索用时 109 毫秒
101.
102.
H?Bukulmez AL?Matthews CM?Sullivan C?Chen MJ?Kraay RC?Elston RW?Moskowitz VM?Goldberg ML?WarmanEmail author 《Arthritis research & therapy》2005,8(1):R25
In order to determine whether there is a genetic component to hip or knee joint failure due to idiopathic osteoarthritis (OA),
we invited patients (probands) undergoing hip or knee arthroplasty for management of idiopathic OA to provide detailed family
histories regarding the prevalence of idiopathic OA requiring joint replacement in their siblings. We also invited their spouses
to provide detailed family histories about their siblings to serve as a control group. In the probands, we confirmed the diagnosis
of idiopathic OA using American College of Rheumatology criteria. The cohorts included the siblings of 635 probands undergoing
total hip replacement, the siblings of 486 probands undergoing total knee replacement, and the siblings of 787 spouses. We
compared the prevalence of arthroplasty for idiopathic OA among the siblings of the probands with that among the siblings
of the spouses, and we used logistic regression to identify independent risk factors for hip and knee arthroplasty in the
siblings. Familial aggregation for hip arthroplasty, but not for knee arthroplasty, was observed after controlling for age
and sex, suggesting a genetic contribution to end-stage hip OA but not to end-stage knee OA. We conclude that attempts to
identify genes that predispose to idiopathic OA resulting in joint failure are more likely to be successful in patients with
hip OA than in those with knee OA. 相似文献
103.
In the pathogenesis of Parkinson’s disease and Huntington’s disease excitotoxicity may play an important role. The common
toxin model for Parkinson’s disease is MPTP, while for Huntington’s disease it is 3-NP. These toxins inhibit the mitochondrial
respiratory chain, resulting in an energy deficit. In the central nervous system, the amino acids act as neurotransmitters
and neuromodulators. The energy deficit caused by these neurotoxins may alter the concentrations of amino acids. Thus, it
can be claimed that the aminoacidergic neurotransmission can be changed by neurotoxins. To test this hypothesis we studied
the amino acid concentrations in different brain regions following MPTP or 3-NP administration. The two toxins were found
to produce similar changes. We detected marked decreases in most of the amino acid concentrations in the striatum and in the
cortex, while the levels in the cerebellum increased significantly. The decreased amino acid levels can be explained by the
reduced levels of ATP produced by these neurotoxins. In the cerebellum, where there is no detectable ATP loss, the elevated
amino acid levels may reflect a compensation of the altered neurotransmission. 相似文献
104.
Rapid evolution of immunoglobulin superfamily C2 domains expressed in immune system cells 总被引:6,自引:3,他引:3
To test the hypothesis that proteins expressed in cells of the vertebrate
immune system evolve unusually rapidly, 107 orthologous immunoglobulin C2
domains were compared between human and murine rodent. The analysis showed
that the rate of nonsynonymous (amino-acid- altering) nucleotide
substitution in these domains was correlated with factors associated with
protein structure and with breadth of tissue expression, as well as with
the rate of synonymous substitution. However, when such factors were
controlled for statistically, there remained a strong positive association
between expression in the immune system and nonsynonymous rate, with the
highest rates being seen in genes expressed in the immune system only.
Certain immune system genes are known to be subject to positive selection
favoring diversity at the amino acid level; most of these genes encode
receptors that interact directly with foreign antigens. The observed
acceleration of the rate of nonsynonymous evolution in C2 domains of immune
system proteins may be explained by either (1) reduced constraint at the
amino acid level on molecules interacting with immune system receptors that
are themselves evolving rapidly due to positive diversifying selection or
(2) positive selection favoring amino acid changes correlated with changes
in the immune system receptors.
相似文献
105.
Summary When inoculated at high cell densities, three strains of Pseudomonas cepacia degraded the polycyclic aromatic hydrocarbons (PAHs) benzo[a]pyrene, dibenz[a,h]anthracene and coronene as sole carbon and energy sources. After 63 days incubation, there was a 20 to 30% decrease in the concentration of benzo[a]pyrene and dibenz[a,h]anthracene and a 65 to 70% decrease in coronene concentration. The three strains were also able to degrade all the PAHs simultaneously in a PAH substrate mixture containing three-, four-, five- and seven-benzene ring compounds. Furthermore, improved degradation of the five- and seven-ring PAHs was observed when low molecular weight PAHs were present. 相似文献
106.
107.
OMAR HAMARSHEH WOLFGANG PRESBER ZIAD ABDEEN SAMER SAWALHA AHMAD AL‐LAHEM GABRIELE SCHOENIAN 《Molecular ecology resources》2006,6(3):826-828
Phlebotomus papatasi is a proven vector of Leishmania major which is one of the causative agents of cutaneous leishmaniasis in the Old World. Although it has a wide geographical range, its population structure is not yet well understood. In an effort to better understand the population dynamics of this vector, we developed a panel of di‐ and trinucleotide microsatellite markers, using a magnetic bead hybridization enrichment protocol. These microsatellite loci showed three to seven alleles with an expected heterozygosity range between 0.702 and 0.876. The level of polymorphisms found in this study suggests that these microsatellite loci can be used for population analysis of P. papatasi. 相似文献
108.
LIQIONG LI WEIBO SONG KHALED A. S. AL‐RASHEID ALAN WARREN ZICONG LI YUAN XU CHEN SHAO 《Zoological Journal of the Linnean Society》2010,158(2):231-243
The morphology and morphogenesis of a new marine hypotrichous ciliate Pseudoamphisiella elongata sp. nov. isolated from mussel‐farming waters near Qingdao, China, are described based on living and protargol‐impregnated specimens. Morphologically, the new species can be distinguished from its known congeners by its elongate body shape, narrow oral field, having fewer dorsal kineties and caudal cirri, more marginal cirri, and differentiated pretransverse cirri. The identification as a new species is firmly supported by the sequences of the small subunit ribosomal rRNA (SSU rRNA) gene, compared with other known Pseudoamphisiella species, and the phylogenetic analysis. The morphogenetic characteristics can be summarized as follows: (1) the parental adoral zone of membranelles and undulating membranes are entirely rebuilt by the oral primordium, which develops de novo in the outermost region of the cortex; (2) the oral primordium in the opisthe and the frontoventral–transverse (FVT) anlagen in both dividers are formed independently on the cell surface; (3) an ‘extra’ marginal anlage originates to the right of the right marginal anlage, and develops into two or three ‘extra’ marginal cirri; (4) the FVT anlagen develop in the primary mode, and the last FVT streak contributes two migratory cirri (frontoterminal cirri), which are probably resorbed; (5) the right marginal anlagen in both dividers occur close together, independent of the old structure. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 158 , 231–243. 相似文献
109.
110.
Julie A Pattemore James K Hane Angela H Williams Bree AL Wilson Ben J Stodart Gavin J Ash 《BMC genomics》2014,15(1)