首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   5552篇
  免费   291篇
  国内免费   191篇
耳鼻咽喉   97篇
儿科学   58篇
妇产科学   50篇
基础医学   895篇
口腔科学   118篇
临床医学   632篇
内科学   1101篇
皮肤病学   126篇
神经病学   462篇
特种医学   391篇
外科学   741篇
综合类   62篇
预防医学   230篇
眼科学   68篇
药学   520篇
中国医学   80篇
肿瘤学   403篇
  2023年   45篇
  2022年   168篇
  2021年   241篇
  2020年   113篇
  2019年   126篇
  2018年   158篇
  2017年   128篇
  2016年   196篇
  2015年   351篇
  2014年   360篇
  2013年   418篇
  2012年   578篇
  2011年   552篇
  2010年   284篇
  2009年   269篇
  2008年   329篇
  2007年   355篇
  2006年   259篇
  2005年   173篇
  2004年   116篇
  2003年   100篇
  2002年   93篇
  2001年   85篇
  2000年   75篇
  1999年   53篇
  1998年   61篇
  1997年   37篇
  1996年   37篇
  1995年   31篇
  1994年   29篇
  1993年   25篇
  1992年   21篇
  1991年   12篇
  1990年   15篇
  1989年   19篇
  1988年   25篇
  1987年   14篇
  1986年   5篇
  1985年   8篇
  1984年   3篇
  1983年   3篇
  1982年   5篇
  1981年   7篇
  1980年   8篇
  1978年   3篇
  1977年   5篇
  1976年   5篇
  1975年   5篇
  1958年   14篇
  1955年   4篇
排序方式: 共有6034条查询结果,搜索用时 15 毫秒
991.
There are no surrogate markers for the development of postherpetic neuralgia (PHN) in patients with herpes zoster (HZ). All patients with HZ were prospectively enrolled to evaluate the associations of saliva varicella zoster virus (VZV) DNA persistence and VZV-specific cell-mediated immunity (CMI) with the development of PHN. Slow clearers were defined if salivary VZV DNA persisted after day 15. Salivary VZV was detected in 60 (85.7%) of a total of 70 patients with HZ on initial presentation. Of 38 patients for whom follow-up saliva samples were available, 26 (68.4%) were classified as rapid clearers and 12 (31.6%) as slow cleares. Initial VZV-specific CMI was lower in slow clearers than rapid clearers (median 45 vs 158 spot forming cells/10 6 cells, P = .02). Of the 70 patients with HZ, 22 (31.4%) eventually developed PHN. Multivariate analysis showed that slow clearers (OR, 15.7, P = .01) and lower initial VZV-specific CMI (OR, 13.8, P = .04) were independent predictors of the development of PHN, after adjustment for age and immunocompromised status. Initial low VZV CMI response and persistence of VZV DNA in saliva may be associated with the development of PHN.  相似文献   
992.
OBJECTIVE: To evaluate the effect of interferon-alpha2B on mumps orchitis, often caused by postpubertal mumps and which can result in permanent testicular atrophy. PATIENTS AND METHODS: The study included 21 patients with mumps orchitis, treated between May 1990 and June 1997. Patients were randomly assigned into two groups: in group 1, 13 patients received therapy with interferon-alpha2B (3 x 10(6) IU per day) and group 2 did not, acting as controls. All were evaluated by measurements of testis size, mumps virus titre, hormone level and semen analysis. RESULTS: In group 1, the patients' symptoms resolved within 2-3 days and the volume of the testes returned to normal within 11 days; there was no testicular atrophy in any patient during the follow-up. However, asthenospermia continued to be detected in four patients (unilateral in two, bilateral in two). In group 2, the patients' symptoms resolved within 5-6 days and the volume of the testes returned to normal within 10 days; testes atrophied in three patients (unilateral in two, bilateral in one) during the follow-up. Asthenospermia continued in four patients (unilateral in two, bilateral in two). CONCLUSION: These results suggest that treatment with systemic interferon-alpha2B is effective in preventing testicular atrophy when combined with standard symptomatic treatment.  相似文献   
993.
Vesico-ureteric reflux: occurrence and long-term risks   总被引:1,自引:0,他引:1  
The prevalence of vesico-ureteric reflux in the general population is unknown, but it is increased in risk groups, such as children with symptomatic urinary tract infection, schoolgirls with asymptomatic bacteriuria, first-degree relatives of patients with reflux and children with prenatal dilatation of their upper urinary tract. Children and adults with pyelonephritic renal scarring are at risk of serious long-term complications, e.g. hypertension and renal failure. Modern paediatric care, with early detection and treatment of urinary tract infections and reflux during childhood and adolescence, may improve long-term prognosis. In the adult patient with established pyelonephritic renal scarring, careful control of hypertension may retard the rate of progression, and angiotensin converting enzyme inhibitors may have renal protective properties.  相似文献   
994.
We investigated the developmental changes of detergent-insoluble characteristics of NMDA and AMPA receptor subunits in the synaptic membranes prepared from the rat cerebral cortex. At postnatal day (PND) 1, the majority of NMDAR1 and NMDAR2B subunits of NMDA receptors in the synaptic membranes were insoluble to the treatment of 1% Triton X-100. The detergent-insoluble properties of both subunits were not significantly changed during postnatal development. At PND 1, about 45% of GluR1 and 10% of GluR2/3 subunits of AMPA receptors in the synaptic membrane were insoluble to Triton X-100, whereas 70% of GluR1 and 56% of GluR2/3 subunits were insoluble at PND 22. These findings indicate that the postsynaptic clustering of NMDA and AMPA receptors during development seems to be differentially regulated in vivo.  相似文献   
995.
We present autopsy findings of a 22-year-old man who developed chest pain 5 days after the first dose of the BNT162b2 mRNA vaccine and died 7 hours later. Histological examination of the heart revealed isolated atrial myocarditis, with neutrophil and histiocyte predominance. Immunohistochemical C4d staining revealed scattered single-cell necrosis of myocytes which was not accompanied by inflammatory infiltrates. Extensive contraction band necrosis was observed in the atria and ventricles. There was no evidence of microthrombosis or infection in the heart and other organs. The primary cause of death was determined to be myocarditis, causally-associated with the BNT162b2 vaccine.  相似文献   
996.
997.
肝硬变和肝细胞癌组织中CD54,CD80,CD86和HLA-ABC的表达   总被引:7,自引:7,他引:0  
目的探讨CD54,CD80,CD86和HLA-ABC在肝硬变的免疫损伤和抗肝癌免疫中的意义.方法用免疫组化方法检测CD54,CD80,CD86和HLA-ABC在肝硬变(n=30)和肝癌(n=48)中的表达、定位和分布.结果在LC中,CD54阳性率为40%(12/30),CD80为50%(15/30),CD86为37%(11/30),HLA-ABC为63%(19/30);在HCC中,CD54阳性率为77%(37/48),CD80为19%(9/47),CD86为13%(6/47),HLA-ABC为30%(12/40);在癌周围组织(PCT)中,CD54为阴性,CD80阳性率为44%(14/32),CD86为47%(15/32),HLA-ABC为53%(17/32).统计学处理显示,在LC中,CD54阳性率显著低于HCC(P<0.01);CD80(P<0.01),CD86(P<0.05)和HLA-ABC(P<0.01)均显著高于HCC;而与PCT无显著差别.在HCC中,CD80(P<0.05),CD86(P<0.01),HLA-ABC(P<0.05),均显著低于PCT.结论 CD54,CD80,CD86和HLA-ABC在LC和HCC中的同时足量表达有可能引起肝细胞损伤和有效抗肿瘤免疫应答,而CD80,CD86表达的缺失或不足可能是HCC产生免疫逃避的主要原因.  相似文献   
998.
Background/AimsThe mucoprotective drug rebamipide is used to treat gastritis and peptic ulcers. We compared the efficacy of Mucosta (rebamipide 100 mg) and its new formulation, AD-203 (rebamipide 150 mg), in treating erosive gastritis.MethodsThis double-blind, active control, noninferiority, multicenter, phase 3 clinical trial randomly assigned 475 patients with endoscopically proven erosive gastritis to two groups AD-203 twice daily or Mucosta thrice daily for 2 weeks. The intention-to-treat (ITT) analysis included 454 patients (AD-203, n=229; Mucosta, n=225), and the per-protocol (PP) analysis included 439 patients (AD-203, n=224; Mucosta, n=215). The posttreatment assessments included the primary (erosion improvement rate) and secondary endpoints (erosion and edema cure rates; improvement rates of redness, hemorrhage, and gastrointestinal symptoms). Drug-related adverse events were evaluated.ResultsAccording to the ITT analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta-treated patients were 39.7% and 43.8%, respectively. According to the PP analysis, the erosion improvement rates (posttreatment) in AD-203-treated and Mucosta-treated patients were 39.3% and 43.7%, respectively. The one-sided 97.5% lower limit for the improvement rate difference between the study groups was −4.01% (95% confidence interval [CI], –13.09% to 5.06%) in the ITT analysis and −4.44% (95% CI, –13.65% to 4.78%) in the PP analysis. The groups did not significantly differ in the secondary endpoints in either analysis. Twenty-four AD-203-treated and 20 Mucosta-treated patients reported adverse events but no serious adverse drug reactions; both groups presented similar adverse event rates.ConclusionsThe new formulation of rebamipide 150 mg (AD-203) twice daily was not inferior to rebamipide 100 mg (Mucosta) thrice daily. Both formulations showed a similar efficacy in treating erosive gastritis.  相似文献   
999.
1000.
Various studies have highlighted the importance of ethnic differences. The consideration of ethnic differences in the field of individualized pharmacotherapy is imperative. Therefore, various organizations and networks across countries should aim to conduct multicountry and multiregional clinical trials (MRCTs). If there is solid evidence available to evaluate the existence of ethnic differences between the same regional areas, it will lead to an increase in the efficiency of drug development. The purpose of this paper was to compare the approval dosing regimen among four Asian countries (Korea, Japan, China, and Taiwan) and elucidate the readiness and current status of the implementation of the International Conference on Harmonization (ICH) E17 guidelines on MRCTs. Reducing unnecessary clinical trials via multinational clinical trials in East Asian countries is also suggested. The approved dosing regimens for some drugs in the four Asian countries were similar; however, some differences might be caused by differences in legislation, even though there were no ethnic differences. This indicates that there are several roles to be expected of the Asia Clinical Pharmacology study network for exploratory MRCTs, which would lead to the accumulation of evidence for MRCTs, ultimately accelerating the efficiency of drug development in East Asian countries. The exposure of the new treatment to the necessary patients through collaborative research coordination and simultaneous multinational subject recruitment would serve its role in providing East Asia with specific personalized medicine with a high treatment success rate.

Study Highlights
  • WHAT IS THE CURRENT KNOWLEDGE ON THE TOPIC?
There is an increased need to consider ethnic differences in drug development. Simultaneously, the demand for conducting multicountry and multiregional clinical trials (MRCTs) has significantly increased.
  • WHAT QUESTION DID THIS STUDY ADDRESS?
This study addresses the current status of ethnic sensitivity in Asia, suggesting specific therapeutic areas that require ethnic sensitivity evaluation in the early phases.
  • WHAT DOES THIS STUDY ADD TO OUR KNOWLEDGE?
This study focuses on the current status of ethnic sensitivity among four Asian countries (Korea, Japan, China, and Taiwan) based on comparisons of their approved dosing regimens. Differences in approved dosing regimens are potentially a result of differences in legislation despite having no ethnic differences.
  • HOW MIGHT THIS CHANGE CLINICAL PHARMACOLOGY OR TRANSLATIONAL SCIENCE?
It proposes the establishment of an Asia Clinical Pharmacology study network comprising Asian investigators in the field of clinical pharmacology and therapeutics to support the implementation of International Conference on Harmonization (ICH) E17 guidelines. This would lead to the accumulation of evidence for the ethnic sensitivity of MRCTs ultimately accelerating the efficiency of drug development in Asian countries.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号