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181.
60Co事故受照人员远期细胞遗传学效应观察   总被引:4,自引:1,他引:3  
对三例钴源事故受照人员照后6(7)年和11(12)年两次细胞遗传学随访结果表明,两次随访受照者染色体畸变率分别为4.29%和3.63%,均显著高于对照组(P<0.01),但两次随访间未见显著差异(P>0.05),而且第一次随访染色体畸变是以双+环和无着丝粒断片为主,第二次随访是以易位、缺失和倒位为主;两次随访受照者微核率分别为4.17‰和1.17‰,第二次随访微核率明显下降(P<0.01)。提示随着照后时间推移, 非稳定性染色体畸变逐渐丢失,稳定性染色体畸变仍保持在较高水平。 Abstract: The analyses of chromosome aberrations and micronuclei in peripheral blood lymphocyte were performed in 3 cases exposed to 60Co radiation accident in 6(7) years and 11(12) years after irradiation. The results show that the frequencies of chromosome aberrations in exposed cases were 4.29% in 6(7) years and 3.63% in 11(12) years after irradiation, respectively, and the difference was not significant in the two times follow-up study. Most of the chromosome aberrations were acentric and dicentric chromosomes in first time follow-up study, and translocation, deletion and inversion chromosomes in second time follow-up one. The frequencies of micronuclei in exposed group were 4.17‰ and 1.17‰ in the two times follow-up study, respectively, and the rates of micronuclei in second time follow-up study were much lower than that in first one. The results indicated that the unstable type aberrations were gradually lost as time goes on ,and the level of stable type aberration was of high degree.  相似文献   
182.
撒坝猪血清酯酶多态性与繁殖性能关系的研究   总被引:5,自引:2,他引:3  
采用垂直板聚丙烯酰胺凝胶电泳法(PAGE), 对115头撒坝猪的血清酯酶(ES)多态性进行了检测,计算了该位点的基因型频率、基因频率和位点多态杂合度(h),并用二因素有互作的最小二乘模型对血清酯酶多态性与繁殖性能的关系进行了分析。结果表明,撒坝猪血清酯酶3种基因型AA、AB和BB的频率分别为0.2696、0.5826和0.1478。两个等位基因A和B的基因频率分别为0.5609和0.4391。该位点的杂合度为0.4926。在3种基因型中,不同基因型母猪的繁殖性能在产仔数、仔猪初生窝重、20日龄窝重、断奶仔猪数和断奶窝重等性状上存在着显著差异(P<0.05);公、母猪不同基因型交配组合在产仔数、断奶仔猪数、仔猪断奶体重和断奶窝重等性状上亦有显著差异(P<0.05)。显示出猪的血清酯酶多态性可望作为繁殖性能选种的遗传标记。 Abstract: Serum esterase polymorphisms of 115 Saba pigs were investigated by using the method of vertical polyacrylamide gel electrophoresis. The genotype frequency, gene frequency and heterozygosity of this locus were calculated. The relationship between the serum esterase polymorphism and reproductive performance was analyzed by the least square analysis of two factors (ES genotype of boar and sow) with interaction. The results demonstrated that the genotype frequency of AA, ABandBBwas 0.2696, 0.5826 and 0.1478 respectively, the gene frequency of the alleleAandBwas 0.5609 and 0.4391 respectively. The heterozygosity of this locus was 0.4926. There are significant differences (P<0.05) on litter size, litter weight at birth, litter weight at 20 days, litter size at weaning and litter weight at weaning of different genotypic sows. The significant differences (P<0.05) were showed on litter size, litter size at weaning, weaning weight and litter weight at weaning of different genotypic mating combinations. It indicated that the serum esterase polymorphism was expected to be the genetic marker of pig reproductive performance.  相似文献   
183.
184.
The selective degradation of many short一lived or abnormal Proteins in eukaryotic cells 15 carried out by the ubiquitin system.In this Pathway,Proteins are targeted for degradation by covalent ligation to ubiquitin,a highly conserved 76一resid…  相似文献   
185.
Leber氏病的mtDNA突变   总被引:3,自引:2,他引:1  
Leber氏病是一种典型的母系遗传病,表现为急性、亚急性视神经萎缩,Wallace于1988年首次证实了此病患者中存在mtDNA的特异性改变—Wallace突变。我们研究了8个独立来源的中国汉族人Leber氏病患者,其中在4个患者中找到了mtDNA的Wallace突变,支持了Wallac。关于Leber氏病发病机理的假说。  相似文献   
186.
染色体组在整个细胞周期中是连续存在的。但在光镜下观察,绝大多数真核细胞的间期核仅能见到网状的结构——染色质,只有当细胞进入有丝分裂期才出现凝聚和盘绕成棒状的染色体。然而,运用体细胞融合技术使有丝分裂的细胞和问期细胞相融合,将会导致间期核的染色质凝聚为染色体样的结构。1970年  相似文献   
187.
The molecular mechanisms of plant recognition, colonization, and nutrient exchange between diazotrophic endophytes and plants are scarcely known. Herbaspirillum seropedicae is an endophytic bacterium capable of colonizing intercellular spaces of grasses such as rice and sugar cane. The genome of H. seropedicae strain SmR1 was sequenced and annotated by The Paraná State Genome Programme--GENOPAR. The genome is composed of a circular chromosome of 5,513,887 bp and contains a total of 4,804 genes. The genome sequence revealed that H. seropedicae is a highly versatile microorganism with capacity to metabolize a wide range of carbon and nitrogen sources and with possession of four distinct terminal oxidases. The genome contains a multitude of protein secretion systems, including type I, type II, type III, type V, and type VI secretion systems, and type IV pili, suggesting a high potential to interact with host plants. H. seropedicae is able to synthesize indole acetic acid as reflected by the four IAA biosynthetic pathways present. A gene coding for ACC deaminase, which may be involved in modulating the associated plant ethylene-signaling pathway, is also present. Genes for hemagglutinins/hemolysins/adhesins were found and may play a role in plant cell surface adhesion. These features may endow H. seropedicae with the ability to establish an endophytic life-style in a large number of plant species.  相似文献   
188.
The objectives of this study were to determine the interval from ovulation to deviation and the diameter of the dominant (DF) and largest subordinate (SF) follicles at deviation in buffalo (Bubalus bubalis) heifers. Two methods of evaluation (observed vs. calculated) were used. FSH and LH profiles encompassing follicle deviation (Experiment 1), and the follicular diameter when the DF acquired ovulatory capacity (Experiment 2) were also determined. The time of deviation and the diameter of the DF and the largest SF at deviation did not differ between observed and calculated methods. Overall, follicle deviation occurred 2.6 ± 0.2d (mean ± SEM) after ovulation, and the diameters of the DF and SF at deviation were 7.2 ± 0.2 and 6.4 ± 0.2mm, respectively. No changes in plasma levels of FSH or LH were observed (P=0.32 and P=0.96, respectively). Experiment 2 was conducted in two phases according to the diameter of the DF during the first wave of follicular development at the time of LH challenge (25mg of pLH). In the first phase, follicles ranging from 5.0 to 6.0mm (n=7), 6.1 to 7.0mm (n=11), or 7.1 to 8.0mm (n=9) were used, and in the second phase, follicles ranging from 7.0 to 8.4mm (n=10), 8.5 to 10.0mm (n=10), or 10.1 to 12.0mm (n=9) of diameter were used. After the pLH treatment, the DF was monitored by ultrasonography every 12h for 48h. No ovulations occurred in heifers in the first phase. However, in the second phase, an effect of follicular diameter was observed on ovulation rate [7.0-8.4mm (0.0%, 0/10), 8.5-10.0mm (50.0%, 5/10), and 10.0-12.0mm (55.6%, 5/9)]. In summary, follicle deviation occurred 2.6d after ovulation in buffalo (B. bubalis) heifers, when the diameters of the DF and SF were 7.2 and 6.4mm, respectively. No significant changes in plasma concentrations of FSH or LH were detected. Finally, the acquisition of ovulatory capacity occurred when the DF reached 8.5mm in diameter.  相似文献   
189.
190.
A clone (LP001) expressing a new lipase gene was isolated from a metagenomic library of the Brazilian Atlantic Forest soil. The DNA insert of LP001 was fully sequenced, and 38 ORFs were identified. Comparison of ORFs, %G + C content and gene organization with sequenced bacterial genomes suggested that the fosmid DNA insert belongs to an organism of the Acidobacteria phylum. Protein domain analysis and inactivation by transposon insertion showed that the protein encoded by ORF29 was responsible for the lipase activity and was named LipAAc. The purified LipAAc lipase was capable of hydrolyzing a broad range of substrates, showing the highest activity against p-nitrophenol (pNP) decanoate. The lipase was active over a pH range of 5.0-10.0 and was insensitive to divalent cations. LipAAc is moderately thermostable with optimum temperature between 50 and 60 °C and was thermally activated (80% activity increase) after 1 h incubation at 50 °C. Phylogenetic analysis suggested that the LipAAc is a member of family I of bacterial lipases and clusters with other moderately thermostable lipases of this group. Comparisons of the DNA insert of fosmid LP001 with other acidobacterial genomes and sequence database suggest that lipAAc gene has a fungal origin and was acquired by horizontal transfer.  相似文献   
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