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931.
We developed eight PCR?primer pairs of polymorphic microsatellite loci for the túngara frog Physalaemus pustulosus. Genomic libraries were enriched for one of four microsatellite repeat sequences (CAn, GAn, ATGn and TAGAn). Following characterization of microsatellite loci by sequencing, primers were designed and PCR conditions optimized. Microsatellite PCR‐amplification was tested in 37 frogs from 8 populations in Costa Rica and Panama. Primer sequences, PCR conditions, allelelic diversities and observed as well as expected heterozygosities in the screened populations are described. 相似文献
932.
933.
Annette AM Gerritsen Rob JPM Scholten Willem JJ Assendelft Herman Kuiper Henrica CW de Vet Lex M Bouter 《BMC neurology》2001,1(1):8-7
Background
Carpal tunnel syndrome is a common disorder, which can be treated with surgery or conservative options. However, there is insufficient evidence and no consensus among physicians with regard to the preferred treatment for carpal tunnel syndrome. Therefore, a randomized controlled trial is conducted to compare the short- and long-term efficacy of surgery and splinting in patients with carpal tunnel syndrome. An attempt is also made to avoid the (methodological) limitations encountered in earlier trials on the efficacy of various treatment options for carpal tunnel syndrome. 相似文献934.
M. E. Lucero W. Mueller J. Hubstenberger G. C. Phillips M. A. O’Connell 《In vitro cellular & developmental biology. Plant》1999,35(6):480-486
Summary Cell suspension cultures of Datura innoxia were incubated in the presence of the nitro-substituted explosives 2,4,6-trinitrotoluene (TNT), 1,3,5-trinitro-1,3,5-triazine
(RDX), and 1,3,5,7-tetranitro-1,3,5,7-tetraazocyclooctane (HMX). Cellular tolerance levels and TNT biotransformation kinetics
were examined. Tolerance to TNT varied as cell suspensions aged. Concentrations of RDX or HMX in excess of reported solubility
limits produced no observable changes in cell viability. GC/MS analysis of TNT-treated cell media and cell lysates revealed
rapid removal of TNT. Within 12 h, less than 1% of the initial TNT remained in the growth medium. Aminodinitrotoluenes (ADNTs),
known metabolites of TNT, accumulated transiently in cell lysates, and to a lesser extent in cell media. ADNT concentrations
started to decrease after 3 h. After 12 h, less than 5% of the initial TNT could be detected as ADNT. Total ADNTs never exceeded
26% of initial TNT, suggesting that additional biotransformation steps also occurred. No other nitroaromatics were detected.
A pseudo-first order rate constant for TNT clearance was calculated, k=0.40 h−1. D. innoxia cell suspension cultures demonstrated virtually complete clearance of TNT and of subsequent ADNT metabolites in less than
12 h. This rapid metabolism of nitroaromatics by the Datura cell suspension system indicates the utility of this system for further molecular and biochemical studies. 相似文献
935.
A gene for autosomal recessive symmetrical spastic cerebral palsy maps to chromosome 2q24-25.
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D P McHale S Mitchell S Bundey L Moynihan D A Campbell C G Woods N J Lench R F Mueller A F Markham 《American journal of human genetics》1999,64(2):526-532
Cerebral palsy has an incidence of approximately 1/500 births, although this varies between different ethnic groups. Genetic forms of the disease account for approximately 1%-2% of cases in most countries but contribute a larger proportion in populations with extensive inbreeding. We have clinically characterized consanguineous families with multiple children affected by symmetrical spastic cerebral palsy, to locate recessive genes responsible for this condition. The eight families studied were identified from databases of patients in different regions of the United Kingdom. After ascertainment and clinical assessment, we performed a genomewide search for linkage, using 290 polymorphic DNA markers. In three families, a region of homozygosity at chromosome 2q24-q25 was identified between the markers D2S124 and D2S148. The largest family gave a maximum LOD score of 3.0, by multipoint analysis (HOMOZ). The maximum combined multipoint LOD score for the three families was 5.75. The minimum region of homozygosity is approximately 5 cM between the markers D2S124 and D2S2284. We have shown that a proportion of autosomal recessive symmetrical spastic cerebral palsy maps to chromosome 2q24-25. The identification of genes involved in the etiology of cerebral palsy may lead to improved management of this clinically intractable condition. 相似文献
936.
Ranjan Deka Mark D. Shriver Ling Mei Yu Elisa Mueller Heidreich Li Jin Yixi Zhong Stephen T. Mcgarvey Shyam Swarup Agarwal Clareann H. Bunker Tetsuro Miki Joachim Hundrieser Shih-Jiun Yin Salmo Raskin Ramiro Barrantes Robert E. Ferrell Ranajit Chakraborty 《Journal of genetics》1999,78(2):99-121
We have analysed genetic variation at 23 microsatellite loci in a global sample of 16 ethnically and geographically diverse
human populations. On the basis of their ancestral heritage and geographic locations, the studied populations can be divided
into five major groups, viz. African, Caucasian, Asian Mongoloid, American Indian and Pacific Islander. With respect to the
distribution of alleles at the 23 loci, large variability exists among the examined populations. However, with the exception
of the American Indians and the Pacific Islanders, populations within a continental group show a greater degree of similarity.
Phylogenetic analyses based on allele frequencies at the examined loci show that the first split of the present-day human
populations had occurred between the Africans and all of the non-African populations, lending support to an African origin
of modern human populations. Gene diversity analyses show that the coefficient of gene diversity estimated from the 23 loci
is, in general, larger for populations that have remained isolated and probably of smaller effective sizes, such as the American
Indians and the Pacific Islanders. These analyses also demonstrate that the component of total gene diversity, which is attributed
to variation between groups of populations, is significantly larger than that among populations within each group. The empirical
data presented in this work and their analyses reaffirm that evolutionary histories and the extent of genetic variation among
human populations can be studied using microsatellite loci. 相似文献
937.
Swapnil Tichkule Simone M. Cacci Guy Robinson Rachel M. Chalmers Ivo Mueller Samantha J. Emery-Corbin Daniel Eibach Kevin M. Tyler Cock van Oosterhout Aaron R. Jex 《Molecular biology and evolution》2022,39(4)
Cryptosporidiosis is a major global health problem and a primary cause of diarrhea, particularly in young children in low- and middle-income countries (LMICs). The zoonotic Cryptosporidium parvum and anthroponotic Cryptosporidium hominis cause most human infections. Here, we present a comprehensive whole-genome study of C. hominis, comprising 114 isolates from 16 countries within five continents. We detect two lineages with distinct biology and demography, which diverged circa 500 years ago. We consider these lineages two subspecies and propose the names C. hominis hominis and C. hominis aquapotentis (gp60 subtype IbA10G2). In our study, C. h. hominis is almost exclusively represented by isolates from LMICs in Africa and Asia and appears to have undergone recent population contraction. In contrast, C. h. aquapotentis was found in high-income countries, mainly in Europe, North America, and Oceania, and appears to be expanding. Notably, C. h. aquapotentis is associated with high rates of direct human-to-human transmission, which may explain its success in countries with well-developed environmental sanitation infrastructure. Intriguingly, we detected genomic regions of introgression following secondary contact between the subspecies. This resulted in high diversity and divergence in genomic islands of putative virulence genes, including muc5 (CHUDEA2_430) and a hypothetical protein (CHUDEA6_5270). This diversity is maintained by balancing selection, suggesting a co-evolutionary arms race with the host. Finally, we find that recent gene flow from C. h. aquapotentis to C. h. hominis, likely associated with increased human migration, maybe driving the evolution of more virulent C. hominis variants. 相似文献
938.
939.
T2Rs function as bitter taste receptors 总被引:49,自引:0,他引:49
Bitter taste perception provides animals with critical protection against ingestion of poisonous compounds. In the accompanying paper, we report the characterization of a large family of putative mammalian taste receptors (T2Rs). Here we use a heterologous expression system to show that specific T2Rs function as bitter taste receptors. A mouse T2R (mT2R-5) responds to the bitter tastant cycloheximide, and a human and a mouse receptor (hT2R-4 and mT2R-8) responded to denatonium and 6-n-propyl-2-thiouracil. Mice strains deficient in their ability to detect cycloheximide have amino acid substitutions in the mT2R-5 gene; these changes render the receptor significantly less responsive to cycloheximide. We also expressed mT2R-5 in insect cells and demonstrate specific tastant-dependent activation of gustducin, a G protein implicated in bitter signaling. Since a single taste receptor cell expresses a large repertoire of T2Rs, these findings provide a plausible explanation for the uniform bitter taste that is evoked by many structurally unrelated toxic compounds. 相似文献
940.