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   67126篇
  免费   7286篇
  国内免费   4959篇
耳鼻咽喉   812篇
儿科学   1025篇
妇产科学   610篇
基础医学   6366篇
口腔科学   1320篇
临床医学   8877篇
内科学   8198篇
皮肤病学   863篇
神经病学   2669篇
特种医学   2460篇
外国民族医学   16篇
外科学   5888篇
综合类   14657篇
现状与发展   21篇
一般理论   2篇
预防医学   6155篇
眼科学   1661篇
药学   7752篇
  99篇
中国医学   4987篇
肿瘤学   4933篇
  2024年   363篇
  2023年   1242篇
  2022年   3319篇
  2021年   4046篇
  2020年   3393篇
  2019年   2347篇
  2018年   2517篇
  2017年   2511篇
  2016年   2198篇
  2015年   3535篇
  2014年   4252篇
  2013年   4299篇
  2012年   5842篇
  2011年   6123篇
  2010年   4404篇
  2009年   3629篇
  2008年   3876篇
  2007年   3676篇
  2006年   3366篇
  2005年   2930篇
  2004年   1913篇
  2003年   1766篇
  2002年   1308篇
  2001年   1072篇
  2000年   963篇
  1999年   901篇
  1998年   521篇
  1997年   527篇
  1996年   390篇
  1995年   397篇
  1994年   300篇
  1993年   177篇
  1992年   202篇
  1991年   218篇
  1990年   164篇
  1989年   159篇
  1988年   110篇
  1987年   112篇
  1986年   95篇
  1985年   67篇
  1984年   53篇
  1983年   24篇
  1982年   20篇
  1981年   16篇
  1980年   9篇
  1979年   16篇
  1978年   2篇
  1975年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
The diagnosis of autoimmune bullous diseases is based on clinical observation and on the presence of autoantibodies directed to molecules involved in the adhesion systems of the skin. Immunofluorescence assays are the currently accepted method for detection of autoantibodies; such assays depend greatly on the skill of operators and are difficult to standardize. Recombinant desmoglein-1 (Dsg1), Dsg3, and BP180 peptides, the main autoantigens in pemphigus or bullous pemphigoid, have been used to develop new quantitative enzyme immunoassays (EIA) for the detection of specific antibodies. The present study was undertaken to evaluate the sensitivity and specificity of these immunoassays and to determine the correlation between the results and the clinical aspects of diseases. Serum samples from patients with pemphigus vulgaris, pemphigus foliaceus, bullous pemphigoid, or mucous membrane pemphigoid, from healthy individuals, and from patients with unrelated autoimmune conditions were tested. Anti-desmoglein reactivity was detected in all the patients with pemphigus and in none of the controls. Patients with the more benign form of cutaneous disease had anti-Dsg1 antibodies, while patients with deeper cutaneous lesions or with mucosal involvement had anti-Dsg3 reactivity also, or exclusively. The BP180-based assay was positive for 66.6% of patients with bullous pemphigoid and for none of the patients with mucous membrane pemphigoid, and no reactivity was detected in the control sera. In conclusion, the anti-Dsg1 and anti-Dsg3 assays are useful in the diagnosis of pemphigus and provide information on the clinical phenotype of the disease. However, the sensitivity of EIA for detection of autoantibodies in bullous pemphigoid should be improved by the use of additional antigens or epitopes.  相似文献   
62.
"Spontaneous" remission of leukemia has been observed in both humans and animals. Bierman et al2 in 1953 reported 11 cases of remis- sion in acute lymphoblastic leukemia (ALL) of childhood following acute infectious disease. In 1979 we saw a case of ALL remission in a child following a severe attack of respiratory infection.  相似文献   
63.
64.
65.
Renin- angiotensin system( RAS) candidat-ing gene,such as angiotensinogen( Ag T) as wellas angiotensin- converting enzyme( ACE) genepolymorphism were thought to have positive association with various cardiovasculardiseases.In1 992 ,Jeunemaitre[1] detected a microsatellitepolymorphism in the region of the an-giotensinogen gene which has linked to occur-rence of essential hypertension.Further analysisled to detection of several mutations in the cod-ing region of angiotensinogen gene[2 ] . Ma…  相似文献   
66.
口腔链球丙酮酸氧化酶的克隆和序列分析   总被引:1,自引:0,他引:1  
目的 阐明血链球菌产生过氧化氢及其调节的分子机理。方法 根据已知的肺炎链球菌丙酮酸氧化酶基因(spxB)序列设计PCR引物,扩增血链球菌ATCC10557的丙酮酸氧化酶基因,以pUC18及M13mp18、M13mp19为载体进行克隆和亚克隆,并进行序列分析。结果 成功地从血链球菌ATCC10557扩增出丙酮酸氧化酶基因,获得该基因的全部序列(1788bp),具有完整的开放读框,能编码591个氨基酸的多肽。结论 血链球菌丙酮酸氧化酶基因的克隆和序列分析,为进一步研究调节血链球菌产生过氧化氢的分子机理打下了基础。  相似文献   
67.
The aim of this study is to investigate the effect of electro-acupuncture treatment in acute phase of cerebral infarction on the motor functions. In this randomly controlled trial, 86 patients were allocated to two groups, the experimental group given clinical and electro-acupuncture treatments for a period of 4 weeks, and the control group given clinical treatment plus active and/or passive functional exercise. The result showed that the level of impairment and disability in both groups were improvement according to the Chinese Stroke Scale, Brunnstrom-Fugl-Meyer score, and Barthel Index throughout the study and 3 months after. The motor functions and the activities of daily living (ADL) were improved significantly in the electro-acupuncture group as compared with the control group (P < 0.05). Also, the results showed greater reduction of neurological deficit in the electro-acupuncture group than in the control group. CONCLUSION: Early acupuncture treatment for acute stroke patients may improve motor functions, and consequently the activities of daily living.  相似文献   
68.
普罗布考对体外培养的主动脉平滑肌细胞NF-κB活性的影响   总被引:1,自引:0,他引:1  
目的:观察普罗布考(probucol )对血管平滑肌细胞(VSMCs)核因子κB(NF-κB)活性的调控作用,以探讨probucol在 动脉粥样硬化(AS)和经皮腔内冠状动脉成形术后再狭窄(RS)防治中的某些可能的作用机 制。方法:采用电泳迁移位移测定法观察probucol对VSMCs NF-κB活 性的影响。结果:H2O2或胎牛血清(NCS)处理VSMCs 72 h后,NF -κB活性均明显增强;而加入100 μmol/L probucol 后,NF-κB活性受到部分抑制,抑 制率分别为37.1%和14.8%。结论:Probucol 抑制NCS、H2O2诱导 的VSMCs NF-κB的活性,可能是其临床有效防治RS及AS的作用机制之一。  相似文献   
69.
目的 云南个旧及宣威地区是云南省肺癌的两大点状高发区 ,个旧以矿工为高发人群 ,宣威以农民为高发 ,该两地区肺癌发生的病因已初步阐明 ,本研究旨在深入探讨其发病的分子生物学基础。方法 对 2 6例个旧矿工肺癌患者 ,15例宣威农民肺癌患者 ,应用聚合酶链反应 -单链构象多态性法研究 p5 3第 5至第 8外显子突变 ,并对有突变的个体进行测序。结果 发现云锡矿工肺癌患者中有 13例、宣威农民肺癌患者中有 4例发生 p5 3突变 ,应用 DNA测序 ,发现云锡矿工肺癌中有 1例于第 135位密码子发生突变 ,由 GCC→ GTC,导致氨基酸改变 ,由丙氨酸→缬氨酸 (Ala→ Val) ,宣威农民肺癌患者中有 1例于 2 47位密码子突变 ,由 AAC→ TTC,导致氨基酸发生改变 ,由天冬酰氨→苯丙氨酸 (Asn→ Phe)。结论  p5 3突变在云锡矿工肺癌和宣威农民肺癌中较常发生 ,并发现两例新的突变位点。 p5 3突变与病人的年龄、性别、坑龄及组织学分类无明显联系  相似文献   
70.
Haibin  Wei  Lin  Qian  Junxiu  Wu  Heng  Wang  Qi  Zhang  Yanpeng  Wang  Dahong  Zhang 《Lasers in medical science》2021,36(6):1191-1200

The benefit of transurethral laser prostatectomy over open simple prostatectomy (OSP) is controversial in aged symptomatic benign prostatic hyperplasia (BPH) patients with large volume prostates, and the aim of this study is to compare the safety and efficiency of these two methods. Meta-analysis was applied using the Review Manager V5.3 software and the retrieved randomized controlled clinical trials (RCTs) comparing transurethral laser prostatectomy with OSP were analyzed for the treatment of large volume prostates from 2000 to 2019 in PubMed, Web of Science, Cochrane, and EMBASE datasets. Five RCTs assessing transurethral laser prostatectomy versus OSP were considered suitable for this meta-analysis, which included a total of 448 patients, with 232 patients undergoing laser and 216 patients undergoing OSP. Compared with OSP, although transurethral laser prostatectomy required a longer operative time (weighted mean difference (WMD) 27.49 mins; 95% confidence interval (CI) 16.54–38.44; P?<?0.00001) and obtained a less resected prostate weight (WMD ??11.72 g; 95% CI ??21.75 to ??1.70; P?=?0.02), patients undergoing laser prostatectomy benefited from significantly less hemoglobin decline (??0.97 g/dL; 95% CI ??1.31 to ??0.64; P?<?0.00001), shorter time of catheterization (WMD ??3.67 days; 95% CI ??5.60 to ??1.75; P?=?0.0002), shorter length of hospital stay (WMD ??4.75 days; 95% CI ??6.57 to ??2.93; P?<?0.00001), and less blood transfusion (odds ratio 0.10; 95% CI 0.03 to 0.35; P?=?0.0003). During postoperative follow-up, no significant difference was observed between the two groups in IPSS, QoL, Qmax, and PVR. Both transurethral laser prostatectomy and OSP are safe and effective for large prostates that require prostate resection. Taking into account of less blood loss, shorter catheterization time and hospital stay, and less blood transfusion, transurethral laser prostatectomy may be a better treatment for patients with large prostates.

  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