全文获取类型
收费全文 | 12392篇 |
免费 | 573篇 |
国内免费 | 99篇 |
专业分类
耳鼻咽喉 | 124篇 |
儿科学 | 394篇 |
妇产科学 | 246篇 |
基础医学 | 1405篇 |
口腔科学 | 305篇 |
临床医学 | 872篇 |
内科学 | 2769篇 |
皮肤病学 | 256篇 |
神经病学 | 1066篇 |
特种医学 | 509篇 |
外科学 | 1465篇 |
综合类 | 95篇 |
一般理论 | 5篇 |
预防医学 | 1486篇 |
眼科学 | 579篇 |
药学 | 971篇 |
中国医学 | 21篇 |
肿瘤学 | 496篇 |
出版年
2023年 | 35篇 |
2022年 | 23篇 |
2021年 | 110篇 |
2020年 | 65篇 |
2019年 | 105篇 |
2018年 | 182篇 |
2017年 | 114篇 |
2016年 | 125篇 |
2015年 | 158篇 |
2014年 | 194篇 |
2013年 | 271篇 |
2012年 | 789篇 |
2011年 | 955篇 |
2010年 | 333篇 |
2009年 | 257篇 |
2008年 | 896篇 |
2007年 | 962篇 |
2006年 | 964篇 |
2005年 | 1012篇 |
2004年 | 961篇 |
2003年 | 876篇 |
2002年 | 782篇 |
2001年 | 596篇 |
2000年 | 654篇 |
1999年 | 320篇 |
1998年 | 121篇 |
1997年 | 108篇 |
1996年 | 102篇 |
1995年 | 81篇 |
1994年 | 55篇 |
1993年 | 69篇 |
1992年 | 70篇 |
1991年 | 56篇 |
1990年 | 53篇 |
1989年 | 81篇 |
1988年 | 76篇 |
1987年 | 51篇 |
1986年 | 38篇 |
1985年 | 39篇 |
1984年 | 30篇 |
1983年 | 24篇 |
1982年 | 26篇 |
1981年 | 25篇 |
1980年 | 26篇 |
1979年 | 22篇 |
1978年 | 12篇 |
1977年 | 22篇 |
1976年 | 18篇 |
1975年 | 20篇 |
1974年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
81.
Roca A Quintó L Abacassamo F Loscertales MP Gómez-Olivé FX Fenwick F Cane PA Saiz JC Toms G Alonso PL 《Journal of medical virology》2003,69(4):579-587
Serological responses have been studied in respiratory syncytial virus (RSV) infected children < 1 year of age attending the outpatient department of the Manhiça District Hospital (Mozambique). Molecular characterization of viral RNA in nasopharyngeal aspirates from the infected children indicated a high level of genetic uniformity among the infecting viruses, all of which belonged to a single genotype of RSV group A. A representative virus strain, Moz00, was isolated from one of the infants and was used, together with the group A strain A2 and the group B strain 8/60, as antigens in the quantification of infant antibody responses. In this study, 97.5% (39/40) and 96.4% (27/28) of infected children produced an antibody response against Moz00 detected by the membrane fluorescent antibody test (MFAT) and the neutralization test (NT), respectively. Seroconversion rates decreased when the A2 and 8/60 strains were used as antigen in MFAT (95.4% and 88.2%, respectively) or NT (81.8% and 54.5%, respectively), indicating that antibody responses had both group‐ and strain‐specific components. Antibodies in convalescent sera of infected children were compared with maternally derived antibodies detected in a group of children also < 1 year of age, but with no evidence of RSV infection. The convalescent sera exhibited reduced neutralizing capacity when the 8/60 strain was used as antigen (P = 0.028), suggesting that the infant antibody response lacks neutralizing capacity against strains of the heterologous virus group. Restricted cross‐reactivity and neutralizing capacity of antibodies generated by young children might be expected to induce only moderate protection in subsequent epidemics against genetically distant strains. J. Med. Virol. 69:579–587, 2003. © 2003 Wiley‐Liss, Inc. 相似文献
82.
A novel frame shift mutation in the HMG box of the SRY gene in a patient with complete 46,XY pure gonadal dysgenesis. 总被引:1,自引:0,他引:1
Richard Kellermayer László Halvax Márta Czakó Mohammad Shahid Varinderpal S Dhillon Syed Akhtar Husain Norbert Süle Eva G?m?ri Mariann Mammel Gy?rgy Kosztolányi 《Diagnostic molecular pathology》2005,14(3):159-163
Pure gonadal dysgenesis or Swyer syndrome is a sex-reversal disorder resulting from embryonic testicular regression sequences especially during the first few weeks of fetal life and is induced by mutations in the SRY gene. In the present report, we describe a nonmosaic XY sex-reversed female with pure gonadal dysgenesis. Molecular analysis using sequential PCR to detect Y chromosomal microdeletions showed the presence of SRY, ZFY and AZFa, b and c regions. Automated sequencing of the SRY region revealed a new mutation (deletion of A (adenine) in codon 82 at position +244), leading to a frame shift mutation within the helix I of the HMG-box domain. This mutation generates a truncated protein and is very likely to produce an impairment of SRY DNA binding activity. The present findings further support the functional importance of the putative DNA binding activity of the SRY HMG-box domain. 相似文献
83.
Y.?P.?Wang X.?X.?Zhao K.?Sonntag P.?Wehling R.?J.?SnowdonEmail author 《Chromosome research》2005,13(8):819-826
Genomic in-situ hybridization (GISH) was applied to study the behaviour of addition chromosomes in first and second backcross (BC) progenies
of hybrids between Brassica napus ssp. napus L. (AACC, 2n = 38) and Sinapis alba L. (SS, 2n = 24) produced by electrofusion. With GISH using genomic DNA of S. alba was used as probe it was possible to clearly distinguish both of the parental genomes and effectively monitor the fate of
S. alba chromosomes in the BC1 and BC2 progenies. GISH analysis confirmed the sesquidiploid genome composition (AACCS) of the BC1 progenies, which contained 38 chromosomes from B. napus and 12 chromosomes from S. alba. Genome painting in the pollen mother cells (PMCs) of the BC1 plants revealed intergenomic association between B. napus and S. alba chromosomes, whereby a maximum of 4 trivalents between AC and S chromosomes were identified at metaphase I. In the BC2 progenies, aneuploids with different numbers of additional chromosomes from S. alba, ranging from 1 to 7, were confirmed. Three putative monosomic alien addition lines were characterized, and the results are
discussed with respect to the potential for intergenomic chromosome recombination. 相似文献
84.
Francesca Fernandez Teresa Esposito Rod A Lea Natalie J Colson Alfredo Ciccodicola Fernando Gianfrancesco Lyn R Griffiths 《BMC medical genetics》2008,9(1):109
Background
Migraine is a neurological disorder characterized by recurrent attacks of severe headache, affecting around 12% of Caucasian populations. It is well known that migraine has a strong genetic component, although the number and type of genes involved is still unclear. Prior linkage studies have reported mapping of a migraine gene to chromosome Xq 24–28, a region containing a cluster of genes for GABA A receptors (GABRE, GABRA3, GABRQ), which are potential candidate genes for migraine. The GABA neurotransmitter has been implicated in migraine pathophysiology previously; however its exact role has not yet been established, although GABA receptors agonists have been the target of therapeutic developments. The aim of the present research is to investigate the role of the potential candidate genes reported on chromosome Xq 24–28 region in migraine susceptibility. In this study, we have focused on the subunit GABA A receptors type ε (GABRE) and type θ (GABRQ) genes and their involvement in migraine. 相似文献85.
Summary 1. Action-concentration curves have been plotted for the stimulation of the cat's superior cervical ganglion by acetylcholine. The free and the innervated receptors of the postsynaptic membrane, described by the authors, have been studied separately from this point of view.2. In the case of both the free and the innervated receptors, the action-concentration curves were similar in shape to the enzyme-substrate curve of cholinesterase. Analyzing these curves by the method of Lineweaver and Burk, in the case of free receptors, the dissociation constants of acetylcholine turned out to be: with stimulating RS complexes: 5.4·10–6–2.1·10–5M, with inhibitory RS
2 complexes: 3.2·10–5 – 5.2·10–5 M. The pertaining values for innervated receptors were 3.45 · 10–5 and 2.22 · 10–4 M, respectively.3. The parallelisms and divergences between the cholinesterase and acetylcholine-receptor functions are discussed.With 4 Figures in the Text 相似文献
86.
Hypolaetin-8-glucoside, a flavonoid isolated from SIDERITIS MUGRONENSIS possessing anti-inflammatory activity inhibited dose-dependently the human PRP aggregation induced by ADP with a IC (50) = 2.4 x 10 (-4) M. This action does not seem to be related to cyclo-oxygenase, as this flavonoid is not an inhibitor and even is able to act as a cofactor for this enzyme. 相似文献
87.
Aris A Bonnin JO Solé JO Padró JM Bartomeus F Molet J Oliver B Caralps JM 《Texas Heart Institute journal / from the Texas Heart Institute of St. Luke's Episcopal Hospital, Texas Children's Hospital》1986,13(3):313-319
We report two patients with coarctation of the aorta who were admitted to the hospital with ruptured cerebral artery aneurysms. In both patients, we surgically treated the coarctation and later repaired the intracranial lesion. One patient, a 34-year-old woman, is alive and well after 3 years; whereas, the other, a 19-year-old man, did not survive. We discuss the sequence for surgery, which continues to be subjected to debate. 相似文献
88.
JS Tsang Chi Chung Foo Jeremy Yip Hok Kwok Choi Wai Lun Law Oswens Siu Hung Lo 《The surgeon》2021,19(3):150-155
IntroductionThe difference in outcome between right (RCD) and left colonic diverticulitis (LCD) is not well established. The aim of this study was to analyse the presentation and surgical outcome of RCD versus left-sided disease following emergency surgery.MethodWe conducted a retrospective review of patients presenting with acute diverticulitis over a 10-year period from 2004 to 2014 to a tertiary unit. Patient demographics, Hinchey classification, need for emergency surgery, perioperative outcome and recurrence were evaluated.ResultsIn total 360 patients presented with acute diverticulitis, 218 (61%) were right-sided and 142 (39%) were left-sided. The mean age (57 yrs vs 68 yrs) and median length of stay (4 days vs 5 days) were significantly less in RCD (p < 0.001). The need for emergency surgery was similar between RCD and LCD (30.7% vs 23.2%, p = 0.12). Sixty-seven (31%) patients with RCD required emergency surgery, 42 (62.7%) of these were based on a presumptive diagnosis of appendicitis and underwent laparoscopic appendicectomy only. Operative morbidity (10.4% vs 51.5%, p < 0.001) and mortality were significantly higher in LCD (1.5% v 15.2%, p = 0.007). Subgroup analysis of non-appendicectomy, RCD patients, showed LCD were more likely to require surgery (11.5% vs 23.2%, p = 0.003). There was no difference in recurrence (p = 0.6).ConclusionRight colonic diverticulitis patients are younger and disease course is more benign compared to LCD. Presentation can be confused with appendicitis without proper imaging. In the rare cases where emergency surgery is required, RCD is associated with a lower operative morbidity and mortality compared to left-sided disease. 相似文献
89.
The desert locust Schistocerca gregaria contains a relatively simple but abundant gut microbiota which originated from the insect's diet. The gut bacterial population is dominated by Enterobacteriaceae with a major component of enterococci. Microbial metabolism of secondary plant chemicals in the locust gut produces phenolics useful to the locust host. Some products are antimicrobial and contribute to host defense against pathogens, others are employed by the host as components of the aggregation pheromone. This dual benefit suggests a closer degree of integration between the locust and its microbial community than was previously suspected. 相似文献
90.
Espinet B Solé F Pedro C Garcia M Bellosillo B Salido M Florensa L Camacho FI Baró T Lloreta J Serrano S 《Human pathology》2005,36(11):1232-1237
Mantle cell lymphoma (MCL) is a B-cell neoplasm with a relatively aggressive clinical course. There is a very small subgroup of patients who present with atypical lymphocytes in peripheral blood, with or without lymphocytosis, lymphadenopathy, or splenomegaly, and with an indolent clinical course. They frequently show mutated IgV(H) genes and CD5 negativity. We report an asymptomatic elderly patient who presented with a single submandibular lymphadenopathy. The biopsy showed immunophenotype and t(11;14)(q13;q32) consistent with MCL. The abnormal lymphoid population was also detected in peripheral blood and bone marrow. The patient has remained asymptomatic for 5 years without receiving any therapy. It is uncertain whether these cases represent an early-stage event in the development or an indolent form of MCL. The existence of such asymptomatic patients with an indolent clinical course should induce a strict clinical judgment in terms of therapeutic decisions. 相似文献