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991.
Tomomi Dan Hajime Ikeda Yuki Mitsui Yuji Isagi Hiroaki Setoguchi 《Conservation Genetics》2009,10(4):859-867
Continental island systems harbour relict biota and populations that might have migrated during glacial periods due to the
formation of landbridges. Here we analysed the genetic structure of relict populations of the temperate plant Shortia rotundifolia on the subtropical island of Iriomotejima, Japan. This plant, which inhabits riparian environments, is designated “near threatened”.
Only five extant populations have been found on the island. Our analyses of 10 nuclear microsatellite loci detected genetic
diversity of H
E = 0.488 and H
O = 0.358 for all populations of S. rotundifolia on the island. A high inbreeding coefficient for all populations together (F
IS = 0.316) and each population separately (F
IS = 0.258–0.497) might be attributable to crossing among closely related descendants within a population, an idea that is supported
by the relatedness coefficient. These results and an examination of the populations’ demographic histories suggest that the
extant populations on Iriomotejima have not experienced a recent population bottleneck. The five extant populations were genetically
differentiated (F
ST = 0.283; P < 0.001), suggesting low seed dispersal by gravity and/or low pollen flow via pollinators in the riparian environment. In
addition, population differentiation was not related to genetic distance, implying that at one time, ancestral populations
might have been distributed over a wider area of the island. However, population fragmentation and range contraction might
have occurred at random during the postglacial period. 相似文献
992.
Candidia barbata is an endemic cyprinid fish in Taiwan and suffers habitat destruction caused by human overexploitation. In this study, a
total of 14 polymorphic microsatellite loci from C. barbata were isolated and characterized using an optimized protocol to construct a microsatellite-enriched genomic library. The analysis
of variability was performed in 30 specimens of Taiwan. The mean number of alleles across loci was 4.92 ± 1.44. The levels
of expected and observed heterozygosities varied from 0.1266 to 0.5079, and from 0.0667 to 0.9667, respectively. Frequencies
of null alleles of the 14 loci are not significantly greater than zero. No linkage disequilibrium was detected between loci
in either population. 相似文献
993.
Hiroaki Setoguchi Yuki Mitsui Hajime Ikeda Naofumi Nomura Atsushi Tamura 《Conservation Genetics》2009,10(3):705-707
Nine microsatellite loci were isolated and characterized for the endangered and tertiary relict perennial herb, Tricyrtis ishiiana. The number of alleles ranged from 2 to 33. The expected (H
E) and observed (H
O) heterozygosities were 0.207–0.944 and 0.215–0.813, respectively, from 96 individuals on one population. Five loci exhibited
significantly fewer heterozygotes than expected under Hardy–Weinberg equilibrium (P < 0.05). These primers amplifying microsatellites in this species may provide a useful tool for population genetics to establish
conservation strategy. 相似文献
994.
John C. Marshall Jr. Bruce A. Kingsbury Dennis J. Minchella 《Conservation Genetics》2009,10(2):465-476
Habitat loss and isolation is pervasive in the Midwest U.S. Wetlands are experiencing particularly dramatic declines, yet
there is a paucity of information on the genetic impacts of these losses to obligate wetland vertebrates. We quantified the
genetic variation of extant populations of a shallow wetland specialist and evaluated potential reductions in population size
(i.e. bottlenecks) using seven polymorphic microsatellite DNA markers. We analyzed 228 copperbelly water snakes (Nerodia erythrogaster neglecta), representing populations from three states. Moderate genetic differentiation exists among all three regions (F
ST = 0.12, P < 0.001), with evidence for low levels of differentiation within the federally protected Ohio region (F
ST = 0.025, P = 0.007), and moderate to strong differentiation within the Indiana region (F
ST = 0.23, P < 0.001). Furthermore, Bayesian clustering (i.e. STRUCTURE) supports the separation of the Indiana sites, both from each
other and from all other sampling sites. However, it does not support the separation of the Ohio sites from the Kentucky sites.
Differentiation among sampling sites did not appear to be related to geographic distance, but rather depended on the quality
of terrestrial corridors used for dispersal. Mode shifts in allele frequencies and excess heterozygosity tests were negative,
while M-ratio tests were nearly all positive, indicating the likelihood of historical rather than contemporary population bottlenecks.
However, potential subspecific intergradation in the Kentucky region may have artificially lowered the M-ratio, and we suggest caution when using the M-ratio approach if intergradation is suspected. Our results have conservation implications for wetland management and management
of the copperbelly populations, and emphasizes the importance of protecting wetland complexes. 相似文献
995.
Kuo-Hsiung Wang Ming-Jou Wu Tzen-Yuh Chiang Chang-Hung Chou 《Conservation Genetics》2009,10(4):1163-1165
Euphrasia nankotaizanensis is an endangered flowering plant distributed restrictedly on rocky slope of high mountain peaks in central and northern Taiwan.
In order to undertake a conservation program, especially given impacts of the global warming, it is essential to evaluate
its genetic diversity and population structure. We described nine novel microsatellite primer pairs in E. nankotaizanensis and also examined its relative E. transmorrisonensis. The number of alleles per locus ranged from 7 to 29. Expected (H
E) and observed (H
O) heterozygosities ranged from 0.83 to 0.98 and 0.00 to 0.95, respectively. Eight of the nine microsatellite loci displayed
significant departures from Hardy–Weinberg expectations, likely due to the loss of habitats and the small population size.
Significant linkage disequilibrium (LD) was detected in most loci. Cross-species amplification of microsatellites took place
at five loci. These primers may provide a tool for understanding the demography and population structure of Euphrasia species in Taiwan.
Kuo-Hsiung Wang, Ming-Jou Wu, and Tzen-Yuh Chiang contributed equally to this work. 相似文献
996.
Panyu Hua Tingting Guo Wenchao Liu Shuyi Zhang Stephen J. Rossiter 《Conservation Genetics》2009,10(3):597-600
We used the enriched genomic library method to isolate and characterize dinucleotide microsatellite loci in the least horseshoe
bat, Rhinolophus pusillus. Seventeen loci were obtained and tested on 31 individuals sampled from Guangxi Province in southern China. Thirteen of these
markers were polymorphic with expected heterozygosity ranging from 0.821 to 0.909. A total of 164 alleles were detected and
the number of alleles per locus ranged from 9 to 16 (mean 12.6). These polymorphic markers will be used to assess population
structure in R. pusillus. In addition, successful cross-amplification in five congeneric bat species suggests most of these markers will also be useful
for studying related species. 相似文献
997.
The intermediate horseshoe bat (Rhinolophus affinis) is a widespread species in Southeast Asia. We developed 19 novel microsatellite loci from an enriched genomic library of
the bat, and tested their polymorphism using a single population from Guangdong province, southern China. The number of alleles
ranged from 3 to 15 per locus with the expected and observed heterozygosity ranging from 0.397 to 0.920 and 0.280–0.926, respectively.
Three markers significantly deviated from the Hardy-Weinberg expectations after Bonferroni correction and no linkage disequilibrium
was detected in any of loci. These microsatellite loci will be useful in studying the phylogeography of this species. 相似文献
998.
柔嫩艾美尔球虫EST序列中SSR的获取及分析 总被引:1,自引:0,他引:1
对柔嫩艾美尔球虫EST—SSR进行生物信息学分析,共获取Eimeria tenella EST序列34074条,总长度为16.45Mb,小于12bpSSR的ESTs达7651条,从中获得SSR序列19576条、总长度为0.35Mb,EST—SSRs的频率是48.00%,平均相隔S40bp出现一个长度不小于12bp的SSR。在E.tenella的核苷酸重复基元中,2、3、4、5、6和7bp重复序列在基因组中出现的种类分别有11种472条、49种14710条、31种525条、13种25条、21种43条和15种400条,3碱基重复序列是最丰富的重复单元,占总数的75.14%。各种SSRs中富含G、C碱基的重复单元以GCA出现频率最多(28.63%),次为AGC(17.59%),GCT(8.76%),TGC(7.62%),CTG(7.15%)。 相似文献
999.
1000.
M L Bermingham S C Bishop J A Woolliams R Pong-Wong A R Allen S H McBride J J Ryder D M Wright R A Skuce S WJ McDowell E J Glass 《Heredity》2014,112(5):543-551
Tuberculosis (TB) caused by Mycobacterium bovis is a re-emerging disease of
livestock that is of major economic importance worldwide, as well as being a zoonotic
risk. There is significant heritability for host resistance to bovine TB (bTB) in dairy
cattle. To identify resistance loci for bTB, we undertook a genome-wide association study
in female Holstein–Friesian cattle with 592 cases and 559 age-matched controls from
case herds. Cases and controls were categorised into distinct phenotypes: skin test and
lesion positive vs skin test negative on multiple occasions, respectively. These animals
were genotyped with the Illumina BovineHD 700K BeadChip. Genome-wide rapid association
using linear and logistic mixed models and regression (GRAMMAR), regional heritability
mapping (RHM) and haplotype-sharing analysis identified two novel resistance loci that
attained chromosome-wise significance, protein tyrosine phosphatase receptor T
(PTPRT; P=4.8 × 10−7) and myosin
IIIB (MYO3B; P=5.4 × 10−6). We estimated
that 21% of the phenotypic variance in TB resistance could be explained by all of
the informative single-nucleotide polymorphisms, of which the region encompassing the
PTPRT gene accounted for 6.2% of the variance and a further 3.6%
was associated with a putative copy number variant in MYO3B. The results from
this study add to our understanding of variation in host control of infection and suggest
that genetic marker-based selection for resistance to bTB has the potential to make a
significant contribution to bTB control. 相似文献