全文获取类型
收费全文 | 23025篇 |
免费 | 1582篇 |
国内免费 | 47篇 |
专业分类
耳鼻咽喉 | 384篇 |
儿科学 | 686篇 |
妇产科学 | 413篇 |
基础医学 | 3261篇 |
口腔科学 | 356篇 |
临床医学 | 2206篇 |
内科学 | 4708篇 |
皮肤病学 | 893篇 |
神经病学 | 2358篇 |
特种医学 | 865篇 |
外国民族医学 | 2篇 |
外科学 | 3476篇 |
综合类 | 215篇 |
一般理论 | 5篇 |
预防医学 | 1608篇 |
眼科学 | 368篇 |
药学 | 1454篇 |
中国医学 | 34篇 |
肿瘤学 | 1362篇 |
出版年
2023年 | 114篇 |
2022年 | 115篇 |
2021年 | 328篇 |
2020年 | 212篇 |
2019年 | 280篇 |
2018年 | 624篇 |
2017年 | 428篇 |
2016年 | 541篇 |
2015年 | 593篇 |
2014年 | 585篇 |
2013年 | 930篇 |
2012年 | 1551篇 |
2011年 | 1588篇 |
2010年 | 763篇 |
2009年 | 623篇 |
2008年 | 1222篇 |
2007年 | 1333篇 |
2006年 | 1277篇 |
2005年 | 1202篇 |
2004年 | 1144篇 |
2003年 | 1044篇 |
2002年 | 1018篇 |
2001年 | 587篇 |
2000年 | 563篇 |
1999年 | 554篇 |
1998年 | 167篇 |
1997年 | 125篇 |
1996年 | 104篇 |
1995年 | 121篇 |
1994年 | 121篇 |
1993年 | 96篇 |
1992年 | 254篇 |
1991年 | 292篇 |
1990年 | 237篇 |
1989年 | 236篇 |
1988年 | 202篇 |
1987年 | 213篇 |
1986年 | 200篇 |
1985年 | 211篇 |
1984年 | 138篇 |
1983年 | 141篇 |
1981年 | 95篇 |
1979年 | 140篇 |
1978年 | 101篇 |
1977年 | 93篇 |
1975年 | 117篇 |
1974年 | 122篇 |
1973年 | 101篇 |
1972年 | 111篇 |
1971年 | 99篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
Item CB Stöckler-Ipsiroglu S Willheim C Mühl A Bodamer OA 《Molecular genetics and metabolism》2005,86(1-2):328-334
Guanidinoacetate methyltransferase (GAMT) deficiency is an autosomal recessive error of creatine synthesis characterized by cerebral creatine deficiency, accumulation of guanidinoacetate, mental retardation, epilepsy, and extrapyramidal symptoms. To date, 14 mutations of the GAMT gene in 27 patients have been reported. Mutation analysis was done using direct sequencing of PCR products and denaturing gradient gel electrophoresis in combination with direct sequencing. In contrast, we evaluated the efficiency of a newly developed DHPLC method to detect mutations in the GAMT gene by analysing DNA from 14 GAMT patients with known mutations. PCR amplification of both patient and control DNA was followed by formation of homoduplices and heteroduplices, and their detection by DHPLC. DHPLC identified all mutations tested and is the preferred choice of analytical method. 相似文献
102.
After injecting a horseradish peroxidase (HRP) solution into the vestibular apparatus in goldfish (Carassius auratus), cells in the medulla oblongata exhibited retrogradely transported HRP reaction product. These labeled cells were confined to 3 nuclei, i.e. the nucleus motorius tegmenti of Bartelmez (with the most prominent labeled cell groups), the ventral vestibular nucleus (Dieter's nucleus) and the medial vestibular nucleus. We consider these labeled cells to be the origin of the efferent innervation to the vestibular apparatus in goldfish. Neurons providing efferent innervation to the sensory periphery in the nucleus motorius tegmenti have, as yet, not been described. 相似文献
103.
The repeated administration of the antidepressant maprotiline to adult rats caused the formation of myeloid bodies in the liver. In situ and in the cell-free state they were shown by acid phosphatase cytochemistry to represent lysosomes. When cytoplasmic extracts of the livers of control and treated animals were subjected to velocity-centrifugation in shallow sucrose gradients, it was found that after drug treatment the peak activities of a series of acid hydrolases were (reversibly) displaced to lower sucrose densities. This behaviour was most likely related to the accumulation of phospholipid-rich material within the myeloid bodies. The subcellular distribution, the level in mitochondria-rich fractions, and some kinetic parameters of the various acid hydrolase activities were not appreciably altered by the medication. The diminished structure-linked latency of a number of acid hydrolases, the greater susceptibility to the influence of Triton X-100 and to a hypoosmotic environment, and the occurrence of structurally damaged particles indicated that the myeloid bodies are more fragile than the lysosomes of control livers. 相似文献
104.
Hubacek JA Stüber F Fröhlich D Book M Wetegrove S Rothe G Schmitz G 《Genes and immunity》2000,1(6):405-407
Sepsis is characterised by a systemic inflammatory response to bacterial products during infection, which interestingly both in humans and animal models is gender associated with a higher susceptibility of males than females. The CD14 receptor is involved in activation of cells by lipopolysaccharides released from Gram-negative bacteria and, as recently shown, also by products of Gram-positive bacteria (e.g., peptidoglycans and lipoteichoic acid). The functional relevance of a C(-159)T CD14 polymorphism recently has been shown based on correlation of the T allele to higher plasma levels of soluble CD14, and higher membrane expression on monocytes. We, therefore, now analysed this CD14 polymorphism in 204 patients with severe sepsis and 247 controls. No significant difference of allele frequencies was observed between sepsis patients and controls neither for males nor females. Mortality also was not associated with the polymorphism studied. This may suggest that other mechanisms for lipopolysaccharide recognition, such as the recently described Toll-like receptors are important for inflammatory cell activation in sepsis. 相似文献
105.
102T/C polymorphism of serotonin receptor type 2A gene is not associated with schizophrenia in either Chinese or British populations 总被引:7,自引:0,他引:7
He L Li T Melville C Liu S Feng GY Gu NF Fox H Shaw D Breen G Liu X Sham P Brown J Collier D St Clair D 《American journal of medical genetics》1999,88(1):95-98
Several pieces of evidence implicate serotonin receptors in the aetiology of schizophrenia, and recently a number of studies have reported a genetic association between the 102T/C polymorphism of serotonin receptor type 2A gene and schizophrenia. Unfortunately a number of failures to replicate these positive associations in both Caucasian and Chinese populations have also been reported. We have examined the 102T/C polymorphism by PCR amplification and restriction analysis of DNA from: 202 schizophrenics and 202 controls from Shanghai; 112 schizophrenics and 224 parents from Chengdu, Cina; and 253 schizophrenics and 244 controls from the the UK. We find no evidence of association or transmission disequilibrium between the 102T/C polymorphism and schizophrenia in any of the groups we have examined. We conclude that either the original positive reports occurred by chance or any effect must be minimal, and urge caution in interpreting small positive results derived using data from different centres. 相似文献
106.
107.
The genome of equine arteritis virus (EAV) produces a 3 coterminal-nested set of six subgenomic (sg) viral RNAs during virus replication cycle, and each set possesses a common leader sequence of 206 nucleotides (nt) in length derived from the 5 end of the viral genome. Given the presence of the leader region within both genomic and sg mRNAs, it is likely to contain cis-acting signals that may interact with cellular or viral proteins for RNA synthesis. Gel mobility shift assays indicated that proteins in Vero cell cytoplasmic extracts formed complexes with the positive (+) and negative (-) strands of the EAV leader RNA. Several cell proteins with molecular masses ranging from 74 to 31 kDa and 58 to 32 kDa were detected in UV-induced cross-linking assays with the EAV leader RNA (+) and (-) strands, respectively. In both cases, intense bands were observed at the 58–52 kDa molecular weight markers. Results from competition gel mobility shift assays using overlapping cold RNA probes spanning the leader RNA (+) strand indicated that nt 140–206 are not necessary for binding to cell proteins. 相似文献
108.
Lee YJ Hohoff C Domschke K Sand P Kuhlenbäumer G Schirmacher A Freitag CM Meyer J Stöber G Franke P Nöthen MM Fritze J Fimmers R Garritsen HS Stögbauer F Deckert J 《Neuroscience letters》2005,377(1):40-43
Several biochemical and pharmacological studies suggest that the catecholaminergic system involving the norepinephrine transporter (NET) is relevant for the pathogenesis of panic disorder. Three single nucleotide polymorphisms in the promoter or untranslated 5' region of the NET gene were investigated by means of RFLP analysis in a sample of 115 German patients with panic disorder and 115 matched controls. Statistical analysis failed to show association with the overall diagnosis of panic disorder. In the subgroup of patients with panic disorder without agoraphobia, however, two polymorphisms were found to be associated with the disease (G/C (rs2397771): p < 0.05; T/C (rs2242446): p < 0.01). While our data do not support a major function of the NET gene in the development of panic disorder, it may play a role in the subgroup of panic disorder without agoraphobia. 相似文献
109.
Plamont MA Chasseigneaux S Delasnerie-Lauprêtre N Beaudry P Peoc'h K Laplanche JL 《Neuroscience letters》2003,344(2):132-134
Prion diseases are characterized by the accumulation in the brain of a misfolded and protease-resistant form of the prion protein (PrP(c)). PrP(c) contains an amyloidogenic, neurotoxic sequence that is essential for conversion into PrP(Sc), the pathological isoform. During normal processing, PrP(c) is cleaved at a site within this sequence, and this cleavage is thought to destroy the amyloidogenic potential of the protein. ADAM10, a disintegrin and metalloprotease that plays a key role in the pathogenesis of Alzheimer's disease, was recently shown to use PrP(c) as a substrate. We investigated whether variability in the ADAM10 gene could contribute to the pathogenesis of Creutzfeldt-Jakob disease (CJD), by analyzing a single nucleotide polymorphism (SNP) within ADAM10, as a genetic marker potentially in linkage disequilibrium with a functional polymorphism, in patients with sporadic or variant CJD. We observed no significant differences in ADAM10 genotype or allele frequencies between CJD patients and healthy individuals. Moreover, the distribution of ADAM10 SNP genotypes and alleles did not differ between groups of patients based on genotype at the polymorphic codon 129 of the prion protein gene--the sole major genetic risk factor for CJD identified to date. Our data indicate that ADAM10 is unlikely to confer genetic susceptibility to CJD. 相似文献
110.