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   56269篇
  免费   5376篇
  国内免费   3649篇
耳鼻咽喉   430篇
儿科学   681篇
妇产科学   375篇
基础医学   4717篇
口腔科学   1449篇
临床医学   6845篇
内科学   5977篇
皮肤病学   710篇
神经病学   2050篇
特种医学   2686篇
外国民族医学   20篇
外科学   6816篇
综合类   13228篇
现状与发展   13篇
一般理论   8篇
预防医学   4914篇
眼科学   972篇
药学   5951篇
  58篇
中国医学   4028篇
肿瘤学   3366篇
  2024年   94篇
  2023年   661篇
  2022年   1335篇
  2021年   2291篇
  2020年   2080篇
  2019年   1443篇
  2018年   1599篇
  2017年   1678篇
  2016年   1413篇
  2015年   2517篇
  2014年   3399篇
  2013年   3654篇
  2012年   5210篇
  2011年   5597篇
  2010年   4601篇
  2009年   4078篇
  2008年   4148篇
  2007年   3785篇
  2006年   3656篇
  2005年   2988篇
  2004年   2101篇
  2003年   1736篇
  2002年   1366篇
  2001年   971篇
  2000年   810篇
  1999年   565篇
  1998年   303篇
  1997年   295篇
  1996年   183篇
  1995年   162篇
  1994年   163篇
  1993年   87篇
  1992年   70篇
  1991年   66篇
  1990年   39篇
  1989年   33篇
  1988年   30篇
  1987年   22篇
  1986年   21篇
  1985年   6篇
  1984年   6篇
  1983年   2篇
  1982年   3篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1973年   4篇
  1972年   3篇
  1955年   2篇
  1947年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Recent epidemiological studies suggested that proton pump inhibitor (PPI) use was associated with an increased risk of biliary tract cancer (BTC), however, confounders were not adequately controlled. Our study aimed to evaluate PPI use and subsequent risk of BTC and its subtypes in three well-established cohorts. We conducted a pooled analysis of the subjects free of cancers in UK Biobank (n = 463 643), Nurses' Health Study (NHS, n = 80 235) and NHS II (n = 95 869). Propensity score weighted Cox models were used to estimate marginal HRs of PPIs use on BTC risk, accounting for potential confounders. We documented 284 BTC cases in UK Biobank (median follow-up: 7.6 years), and 91 cases in NHS and NHS II cohorts (median follow-up: 15.8 years). In UK biobank, PPI users had a 96% higher risk of BTC compared to nonusers in crude model (HR 1.96, 95% CI 1.44-2.66), but the effect was attenuated to null after adjusting for potential confounders (HR 0.95, 95% CI 0.60-1.49). PPI use was not associated with risk of BTC in the pooled analysis of three cohorts (HR 0.93, 95% CI 0.60-1.43). We also observed no associations between PPI use with risk of intrahepatic (HR 1.00, 95% CI 0.49-2.04), extrahepatic bile duct (HR 1.09, 95% CI 0.52-2.27) and gallbladder cancers (HR 0.66, 95% CI 0.26-1.66) in UK Biobank. In summary, regular use of PPIs was not associated with the risk of BTC and its subtypes.  相似文献   
3.
目的研究腹腔镜经脐单一部位幽门环肌切开术治疗小儿先天性肥厚性幽门狭窄的临床效果。方法100例小儿先天性肥厚性幽门狭窄患儿作为研究对象,按照随机方式分为观察组和对照组,每组50例。对照组采用腹腔镜幽门环肌切开术治疗,观察组采用腹腔镜经脐单一部位幽门环肌切开术治疗。观察记录患儿的手术结果及随访结果,并比较两组患儿手术时间、术后住院时间。结果手术过程顺利,100例患儿均成功完成手术,无一例中转开腹手术,无并发症发生。观察组患儿术后6 h将胃管取下,少量喂入温水后逐渐过渡到喂糖水、喂奶;对照组患儿术后24 h开始逐渐进食。患儿术后进行6个月的延续性随访,观察组患儿切口恢复美观,已经无法观察到切口瘢痕,两组患儿的生长发育均显示正常状态。观察组患儿手术时间(21.23±1.65)min及术后住院时间(5.58±1.98)d均显著短于对照组的(38.44±1.23)min、(9.67±1.22)d,差异具有统计学意义(P<0.05)。结论先天性肥厚性幽门狭窄患儿采用腹腔镜经脐单一部位幽门环肌切开术治疗,手术效果良好,手术创伤小而且安全。  相似文献   
4.
5.
The research and development of penicillin started with difficulty before 1949 and achieved certain results. In 1951, after the founding of the People's Republic of China, Zhang Weishen, as the only Chinese scientist who had been trained and worked in a penicillin research and development center in the United States for many years, overcame many difficulties and returned to China. In 1953, with the efforts of Zhang Weishen and his colleagues, China realized the industrialized production of penicillin, alleviating the urgent needs of the masses. Antibiotics has also become the first discipline to achieve major scientific and technological achievements after the founding of the New China. In the mid-1950s, the technical breakthrough in the localization of lactose substitutes marked the localization of the raw materials of the penicillin-producing culture medium, which paved the way for the industrialized production of penicillin with Chinese characteristics. Antibiotics have become one of the most widely used and affordable drugs for hundreds of millions of patients in China, and China has since ended the humiliating history of the “Sick Man of East Asia".  相似文献   
6.
7.
8.
9.
BackgroundComminuted patellar fractures are not rare, and the ideal treatment method remains controversial. The present study was conducted to evaluate effects and compare complications of two different methods used to treat comminuted patellar fractures.MethodsFrom March 2010 to August 2016, 102 cases of 34-C2 or 34-C3 comminuted patellar fractures were treated at our hospital, wherein patients received two different treatments: titanium cable tension band with cerclage method (group A) and intrafragmentary screws with X-shaped plating technique (group B). At follow-ups, articular step-off, range of motion (ROM), Lysholm scores, time of union, and complications were recorded and analyzed. Radiographic and clinical data as well as rate of complications were statistically analyzed.ResultsIn total, 87 patients were included in the final analysis (n = 47 in group A and n = 40 in group B). No significant differences were noted in terms of cost of implant, age, gender, rate of 34-C3 fractures, rate of layered inferior pole fractures, postoperative articular step-off and union time. At 2-year follow-up, average Lysholm scores, ROM and rate of complications were (89.0 ± 4.5), (122°±12°) and (27.7%) in group A and (90.2 ± 3.9), (124°±11°) and (17.5%) in group B, respectively, with no significant differences (p > 0.05). The mean time of surgery in group B was shorter than that in group A with significant difference (p < 0.05).ConclusionsTreatment using the intrafragmentary screws and plate method for amenable comminuted patellar fractures achieved similar complication rate and favorable functional outcomes at the 2-year follow-up, which was comparable to the titanium cable tension band with cerclage method. Thus, the intrafragmentary screws and plate method is effective, safe and convenient for 34-C2/C3 comminuted patellar fractures, especially appropriate for patients with layered fragments.  相似文献   
10.
目的探讨球囊辅助内镜下逆行胰胆管造影术(BAE-ERCP)治疗胆总管/胰-空肠吻合口狭窄后对复发再狭窄的影响。方法以2016年10月至2017年5月于焦作市第二人民医院行BAE+ERCP治疗的78例胆总管/胰-空肠吻合口狭窄患者作为研究对象进行回顾性分析,根据患者术后随访3年的调查,将发生胆总管/胰-空肠吻合口再狭窄的患者列为复发组,未发生胆总管/胰-空肠吻合口再狭窄的患者列为正常组,分析术后复发率情况,并对比两组患者入院时的临床资料、手术相关资料,采用二元Logistic回归分析术后再狭窄的影响因素。结果78例胆总管/胰-空肠吻合口狭窄患者中,术后3年内共发生胆总管/胰-空肠吻合口再狭窄25例,复发率为32.05%,其中一年内复发15例,复发率为19.23%。分组后,经二元Logistic回归分析显示,术后CT检查见吻合部腰状线、原发病术后至BAE-ERCP间隔时间长是影响BAE-ERCP术后胆总管/胰-空肠吻合口再狭窄的独立危险因素(O^R=1.552/1.782,P=0.011/0.004)。结论BAE-ERCP治疗胆总管/胰-空肠吻合口狭窄后1年或3年内均有一定的吻合口再狭窄率,通过观察术后吻合口狭窄恢复情况可判断吻合口再狭窄风险,而通过尽早进行首次BAE-ERCP治疗也可降低吻合口再狭窄的风险。  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