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121.
Mitochondrial DNA (mtDNA) fragments that contained cox2 or atp6 loci were cloned from three accessions of wild soybean (Glycine soja) in order to understand the evolutionary changes of mitochondrial genomes in the genus Glycine subgenus Soja. Cox2 was cloned as a single configuration, while atp6 was cloned as either one or two configurations from each accession. Structural variations were detected in the 5′ upstream
region of cox2 and in both the 5′ upstream and 3′ downstream regions of atp6. These variations appeared to be the results of recombination events. A comparison of the mtDNA fragments previously cloned
from a cultivated soybean (G. max) and a wild soybean revealed various sites of recombination, as well as various combinations of the 5′ and 3′ regions, at
the cox2 and atp6 loci. Some of the cloned fragments were found to contain a set of repeated sequences, namely 299-bp and 23-bp repeats in
the 5′ region of cox2 or atp6, which were interspersed in the mitochondrial genome in the subgenus Soja. Recombination events involving the 299-bp or 23-bp repeated sequences were shown to account for the generation of structural
variations in the 5′ regions of these loci.
Received: 21 March / 4 August 1998 相似文献
122.
Sun X Rokuhara A Tanaka E Gad A Mutou H Matsumoto A Yoshizawa K Kiyosawa K 《Journal of medical virology》2005,76(2):170-175
One hundred and forty four patients with chronic hepatitis B were tested to identify new mutations associated with hepatitis B e antigen (HBeAg) negativity, using a full genome sequence analysis. All the patients were Chinese and had hepatitis B virus infection of genotype C. Patients with none of the pre-core or core promoter mutations were significantly (P < 0.001) less common in the group with anti-HBe (13%) than in the group with HBeAg (56%). The complete nucleotide sequence was determined in four anti-HBe-positive patients who had neither pre-core nor core promoter mutations and in five HBeAg-positive patients who also had neither of these mutations (the groups were matched for age and sex). Six mutations were found to be significantly more common in the former group than in the latter: G529A (3/4 vs. 0/5), C934A (4/4 vs. 1/5), A1053G (4/4 vs. 1/5), G1915T/A (4/4 vs. 0/5), T2005C/A (4/4 vs. 0/5), and C3026T (3/4 vs. 0/5). Three of the six mutations were significantly more common in the four anti-HBe-positive patients who had neither pre-core nor core promoter mutations, compared to 11 HBeAg-positive patients who had pre-core and core promoter mutations, and also compared to 15 anti-HBe-positive patients who had pre-core and core promoter mutations, suggesting further the specificity of these mutations. Of the six mutations, two resulted in amino acid substitution in the polymerase protein, and one is located near the enhancer I region. The results suggest that the six newly discovered mutations are associated with HBeAg negativity. 相似文献
123.
Summary The host-vector system of an n-lkaneassimilating-yeast, Candida maltosa, which we previously constructed using an autonomously replicating sequence (ARS) region isolated from the genome of this yeast, utilizes C. maltosa J288 (leu2
–) as a host. As this host had a serious growth defect on n-alkane, we developed an improved host-vector system using C. maltosa CHI (his) as host. The vectors were constructed with the Candida ARS region and a DNA fragment isolated from the genome of C. maltosa. Since this DNA fragment could complement histidine auxotrophy of both C. maltosa CH1 and S. cerevisiae (hiss
–), we termed the gene contained in this DNA fragment C-HIS5. The vectors were characterized in terms of transformation frequency and stability, and the nucleotide sequence of C-HISS was determined. The deduced amino acid sequence (389 residues) shared 51% homology with that of HISS of S. cerevisiae (384 residues; Nishiwaki et al. 1987). 相似文献
124.
The nucleotide sequence of RNA segment 3 of A/FPV/Rostock/34 (H7N1), an avian strain of influenza A virus, has been determined from a cloned DNA copy. Segment 3 codes for the PA polypeptide and the sequence specifies an acidic polypeptide of 716 amino acid residues. Comparison of the sequence with the corresponding segment of two human strains A/PR/8/34 and A/NT/60/68 indicates significant divergence of the avian sequence from the human sequences at the nucleotide level. At the amino acid level there is considerably greater homology between the avian and human strains. This presumably reflects a constraint on divergence of the PA polypeptide imposed by a common functional requirement of PA in all influenza virus strains. 相似文献
125.
126.
构建7q32区域鼻咽癌和正常鼻咽上皮细胞部分基因的表达图谱 总被引:7,自引:2,他引:7
目的构建7q32区域鼻咽癌细胞和组织及原代培养人正常鼻咽上皮细胞的部分基因表达图谱。方法通过差异RT-PCR和Northern杂交的方法检测定位于7q32区域的20个EST在鼻咽癌细胞和鼻咽癌组织及原代培养人正常鼻咽上皮细胞mRNA的表达水平。结果8个EST在鼻咽癌细胞HNE1和原代培养人正常鼻咽上皮细胞中表达量较一致,7个EST在两种细胞中均无表达,3个EST(W72688、H19830、AA130630)在鼻咽癌细胞株中表达上调,而2个EST(AA070437、H90882)在原代培养人鼻咽上皮细胞中表达上调。在13例鼻咽癌活检组织中30.7%(4/13)的AA070437表达下调,77%(10/13)的W72688和77%(10/13)的H19830表达上升。结论构建了7q32区域鼻咽癌细胞和组织及原代培养人正常鼻咽上皮细胞部分基因表达图谱,并初步认为A070437的表达下调和W72688、H19830的过表达与鼻咽癌的发生有关。 相似文献
127.
Ertunc D Aban M Tok EC Tamer L Arslan M Dilek S 《Human reproduction (Oxford, England)》2005,20(8):2157-2161
BACKGROUND: Glutathione-S-tranferase (GST) is the part of the key phase II detoxifying enzyme system. Many studies have investigated the role of GSTM1 and GSTT1 gene polymorphisms in endometriosis. Although GSTP1 was found to be one of the most abundant types of GST in genital system, there are insufficient data about the importance of the role of GSTP1 gene polymorphism in endometriosis. METHODS: This case-control study involved 150 patients with endometriosis and 150 controls. The frequency of GSTP1 single nucleotide polymorphisms was evaluated using PCR and melting curve analysis. RESULTS: The proportion of GSTP1 ile/ile tended to be higher in patients with endometriosis than control group, although the difference was not significant [odds ratio (OR)=1.53; 95% confidence interval (CI)=0.95-2.46]. In contrast, GSTP1 val/val was significantly higher in control patients and seems protective for endometriosis (OR=0.10; 95% CI=0.02-0.42). CONCLUSION: The results of this study suggest that GSTP1 polymorphism might modulate the risk of endometriosis with significantly decreased risk for GSTP1 val/val and marginally increased risk for GSTP1 ile/ile. Further studies on not only the disease processes but also normal distribution of the enzyme in female genital tract may provide better understanding about the role of GST types and their polymorphs in endometriosis. 相似文献
128.
9株YONBAN相关TTV变异株全基因序列测定及其结构、分型的研究 总被引:1,自引:2,他引:1
目的:对9个TTV新分离株全基因序列测定,基因结构及基因分型的研究。方法:从9名TTV第4基因群感染阳性的婴儿血清中抽提取其DNA,用long inverted PCR扩增出全基因组,克隆和测定全基因组序列,并对测序结果进行计算机分析。结果:首次次测定了TTV第4基因群共9个新分离株的全基因序列,其中8个分离株代表核基因群首次报道的8个新基因型。结论:TTV基因组核酸序列具有高度异质性及基因型的高度多样性,但是,其独特的转录特性和基因组的基本结构在各自的基因群及基因型中十分保守。 相似文献
129.
Analysis of the HIV-1 V3 quasispecies present in an individual at the time of seroconversion was carried out. The polymerase chain reaction (PCR) was used to amplify proviral HIV-1 DNA extracted from peripheral blood mononuclear cells from a patient who was viraemic (p24 = 15 pg/ml) and had an equivocal HIV-1 antibody status. The PCR products were cloned and the DNA sequence determined for 15 clones. These data showed that the V3 region contained only limited sequence heterogeneity with a major variant accounting for 66% of the protein quasispecies present. The protein sequence of the principal neutralising domain on all species contained the relatively rare GPGKTL motif rather than GPGRAF. The relevance of these data for early stages of HIV infection are discussed. 相似文献
130.
Katsoulidou A Paraskevis D Anastassopoulou CG Chryssou SE Sypsa V Boletis J Malliori M Karafoulidou A Tassopoulos NC Hatzakis A 《Journal of medical virology》2001,65(2):423-429
The prevalence of TT virus (TTV) infection in various population groups from Athens, Greece, was assessed by the polymerase chain reaction (PCR) using two primer sets from distinct regions of the genome: the conventional set derived from the open reading frame-1 (ORF-1) and the new, highly sensitive set targeting the region that includes the TATA signal localized upstream of ORF-2. Based on both primer sets, TTV DNA was detected in 42/50 (84.0%) healthy individuals, 42/50 (84.0%) chronic hepatitis C patients, 31/39 (79.5%) acute non-A-E hepatitis patients (group I), 14/16 (87.5%) renal failure patients with acute non-A-E hepatitis (group II), 47/50 (94.0%) intravenous drug users (IVDU), 36/50 (72.0%) hemophiliacs, and 21/31 (67.7%) hemodialysis patients. The presence of TTV was not associated with any particular risk group, and no differences were observed in relation to demographic, biochemical and virological characteristics between TTV DNA-positive and -negative patients. TTV did not seem to have a profound effect on the course of chronic C or acute non-A-E hepatitis either. Phylogenetic analysis revealed that TTV strains circulating in the greater metropolitan area of Athens belong not only to the G1 and G2 genotypes that are encountered worldwide, but also to G3 and to G5 that are found mainly in Europe and Asia, respectively. Further studies will shed light on the role of this highly prevalent virus. 相似文献