全文获取类型
收费全文 | 769篇 |
免费 | 123篇 |
专业分类
892篇 |
出版年
2021年 | 6篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 10篇 |
2016年 | 13篇 |
2015年 | 21篇 |
2014年 | 28篇 |
2013年 | 33篇 |
2012年 | 43篇 |
2011年 | 32篇 |
2010年 | 22篇 |
2009年 | 29篇 |
2008年 | 33篇 |
2007年 | 23篇 |
2006年 | 31篇 |
2005年 | 28篇 |
2004年 | 18篇 |
2003年 | 19篇 |
2002年 | 27篇 |
2001年 | 36篇 |
2000年 | 38篇 |
1999年 | 26篇 |
1998年 | 21篇 |
1997年 | 7篇 |
1996年 | 12篇 |
1995年 | 9篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 21篇 |
1991年 | 22篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 20篇 |
1987年 | 17篇 |
1986年 | 13篇 |
1985年 | 13篇 |
1984年 | 8篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1980年 | 8篇 |
1979年 | 6篇 |
1976年 | 9篇 |
1974年 | 5篇 |
1973年 | 4篇 |
1971年 | 5篇 |
1969年 | 5篇 |
1964年 | 5篇 |
1961年 | 4篇 |
1951年 | 4篇 |
1917年 | 6篇 |
排序方式: 共有892条查询结果,搜索用时 0 毫秒
1.
Published gene frequency data, checked for consistency of allele definitions across laboratories and for comparability of
geographically identical samples, were pooled into a data set containing frequencies at nine loci for each of 20 populations
that encompassed 10 macaque species. Genetic distances were calculated by the methods of Kidd and Cavalli-Sforza (1974). These
distances were used to construct phylogenetic trees and to evaluate the relationships between divergence times and effective
population sizes. Inter-and intraspecific genetic distances and the groupings defined by phenetic tree analyses support Fooden’s
(1976) classification of the genus Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows
us to explain Macacainto four species groups. A paleozoogeographical model of Asia including the known times of major sea-level changes allows
us to explain qualitatively the inferred evolutionary relationships among macaque species. Many assumptions are required in
order to estimate the variables necessary in the quantitative prediction of genetic differences for a comparison between any
two populations. Examination of those assumptions demonstrates the need for more accurate genetic as well as paleozoogeographic
information.
An erratum to this article is available at . 相似文献
2.
Monomorphism in humans and sequence differences among higher primates for a sequence tagged site (STS) in homeo box cluster 2 as assayed by denaturing gradient electrophoresis. 总被引:2,自引:2,他引:0 下载免费PDF全文
G Ruano M R Gray T Miki A C Ferguson-Smith F H Ruddle K K Kidd 《Nucleic acids research》1990,18(5):1314
3.
A refined linkage map for DNA markers around the pericentromeric region of chromosome 10 总被引:3,自引:0,他引:3
J S Wu S Myers N Carson J R Kidd L Anderson C M Castiglione L S Hoyle J B Lichter V P Sukhatme N E Simpson 《Genomics》1990,8(3):461-468
A refined genetic linkage map for the pericentromeric region of human chromosome 10 has been constructed from data on 12 distinct polymorphic DNA loci as well as the locus for multiple endocrine neoplasia type 2A (MEN 2A), a dominantly inherited cancer syndrome. The map extends from D10S24 (at 10p13-p12.2) to D10S3 (at 10q21-q23) and is about 70 cM long. Overall, higher female than male recombination frequencies were observed for this region, with the most remarkable female excess in the immediate vicinity of the centromere, as previously reported. Most of the DNA markers in this map are highly informative for linkage and the majority of the interlocus intervals are no more than 6 cM apart. Thus this map should provide a fine framework for future efforts in more detailed mapping studies around the centromeric area. A set of ordered cross-overs identified in this work is a valuable resource for rapidly and accurately localizing new DNA clones isolated from the pericentromeric region. 相似文献
4.
5.
Predicting genotypes at loci for autosomal recessive disorders using linked genetic markers: application to Wilson's disease 总被引:4,自引:0,他引:4
Lindsay A. Farrer Batsheva Bonne-Tamir Moshe Frydman Abraham Magazanik Kenneth K. Kidd Anne M. Bowcock Luigi L. Cavalli-Sforza 《Human genetics》1988,79(2):109-117
Summary Recently, the Wilson's disease locus (WND) has been mapped to the long arm of chromosome 13. We have analyzed segregation of serveral chromosome 13 markers flanking the WND locus and used multipoint linkage analysis to determine the most likely WND genotype of each of 57 unaffected individuals in 5 Wilson's disease families. Approximately 46% of these could be classified as carrier (heterozygote), homozygous normal, or homozygous affected (not yet symptomatic) with a probability of at least 90%, while 77% could be classified with a probability of at least 80%. Our results demonstrate that even though there is a significant decrease on average in serum copper concentration in Wilson's disease heterozygotes compared to normal homozygotes, other sources of variation in serum copper concentration are much greater and preclude use of serum copper to detect heterozygotes for Wilson's disease. Subsequent analyses showed that a familial component, independent of WND genotype, is the major factor accounting for variation in ceruloplasmin levels among unaffected individuals; age is another factor accounting for more variation in copper levels among unaffected individuals than WND genotype. 相似文献
6.
Richard B. Marchase Vincent J. Kidd Angel A. Rivera Michael G. Humphreys-Beher 《Journal of cellular biochemistry》1988,36(4):453-465
Rat parotid gland acinar cells stimulated to divide by a chronic regimen of isoproterenol demonstrate a dramatic increase in the synthesis of the glycosyltransferase 4β-galactosyltransferase. A plasma membrane localization for much of the increase in 4β-galactosyltransferase was determined by density gradient membrane fractionation. Golgi-enriched fractions showed no increase in specific activity, while plasma membrane activity increased 40-fold. This selective increase at the cell surface was confirmed by immunofluorescence of intact, nonpermeabilized cells from treated glands, using a monospecific antibody prepared against the purified bovine milk transferase. In detergent-permeabilized cells staining of nontreated cells was seen only as groups of perinuclear vesicles, presumed to be Golgi apparatus. In isoproterenol-treated and permcabilized cells both presumptive Golgi and cell surface staining was apparent. Enzyme assays performed on intact cells established that the enzyme's active site was oriented to the exterior of the cells. The transferase could be detected as early as 3 hr after the primary challenge with isoproterenol. Pretrcatment of rats with cycloheximide prevented its appearance. 相似文献
7.
T Miki I Nishisho H Tateishi Y Chen J R Kidd J Wu D Pravtcheva A J Pakstis S Takai F H Ruddle 《Genomics》1988,3(1):78-81
The locus recognized by the probe OS-3 is assigned to chromosome 10 both by Southern blot analysis of a panel of somatic cell hybrid DNAs and by genetic linkage to markers already assigned to chromosome 10. In Caucasians this probe recognizes a three-allele TaqI RFLP as well as two-allele BanII and RsaI RFLPs which are both in strong linkage disequilibrium with each other and with the TaqI RFLP. The D10S20 locus defined by this probe maps 5.5 cM distal to D10S4 on the long arm of chromosome 10. Because this human clone hybridizes with mouse genomic DNA, it will be useful in comparative mapping studies. 相似文献
8.
A linkage group of five DNA markers on human chromosome 10 总被引:3,自引:0,他引:3
Five chromosome 10 DNA markers (D10S1, D10S3, D10S4, D10S5, and RBP3) were typed in five large pedigrees with multiple endocrine neoplasia type 2A (MEN-2A) and in five non-MEN-2A pedigrees. Linkage analyses showed that these loci and the locus for MEN-2A (MEN2A) are in one linkage group spanning at least 70 cM. The order of the marker loci is RBP3-D10S5-D10S3-D10S1-D10S4, with interlocus recombination frequencies of 7, 13-19, 19, and 19%, respectively, all on the same side of MEN2A. Analyses of sex-specific recombination frequencies indicated no significant differences between males and females for any of the map intervals studied. Previous localization of D10S5 and RBP3 to the proximal region of the long arm and the pericentric region, respectively, comparison of results with other studies, and our preliminary results with other chromosome 10 markers suggest that the D10S4 end of the map extends into the long arm. Our linkage map has been constructed using only two- and three-locus analyses. It will be possible to combine our results with those of other groups to construct a more detailed and accurate genetic map of chromosome 10. 相似文献
9.
Beta beta homodimers exist in native rabbit skeletal muscle tropomyosin and increase after denaturation-renaturation. 总被引:1,自引:1,他引:0 下载免费PDF全文
M. E. Holtzer S. G. Kidd D. L. Crimmins A. Holtzer 《Protein science : a publication of the Protein Society》1992,1(3):335-341
Native tropomyosin from rabbit skeletal muscle (RSTm) consists mainly of alpha alpha and alpha beta coiled coils (alpha/beta approximately 3-4/1). In some extant studies, no beta beta molecules have been found. In this study, RSTm from several different preparations was disulfide cross-linked, both preparation and cross-linking being done under nondenaturing conditions. The cross-linked product was assayed for the presence of beta beta molecules cross-linked at both C36 and C190 (beta = beta). In such cross-linked RSTm, 3-8% beta = beta is detected by sodium dodecyl sulfate polyacrylamide gel electrophoresis, C4 reversed-phase high-performance liquid chromatography, and a free-solution capillary electrophoresis experiment. This percentage becomes approximately 4-10% beta beta when corrected for incomplete double cross-linking and is independent of protein concentration (0.1-10.0 mg/mL), indicating that the observed beta beta species are not artifacts due to intermolecular cross-linking. Upon denaturation and subsequent renaturation either by heating to 55 degrees C or by incubating at 45 degrees C followed by quenching to room temperature, or by guanidine hydrochloride exposure followed by phased renaturation by dialysis, the fraction of beta beta increases, indicating that the reassociation favors homodimer formation somewhat over random association. This result differs from the random association observed when the sulfhydryl on one of the chains is carboxyamidomethylated (Holtzer, M.E., Breiner, T., & Holtzer, A., 1984, Biopolymers 23, 1811-1833), and from the overwhelming heterodimer preferences reported for tropomyosins from other organisms (Lehrer, S.S., Qian, Y., & Hvidt, S., 1989, Science 246, 926-928; Lehrer, S.S. & Qian, Y., 1990, J. Biol. Chem. 265, 1134-1138). 相似文献
10.