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   22275篇
  免费   1471篇
  国内免费   921篇
耳鼻咽喉   109篇
儿科学   255篇
妇产科学   296篇
基础医学   4855篇
口腔科学   287篇
临床医学   2167篇
内科学   3960篇
皮肤病学   425篇
神经病学   494篇
特种医学   390篇
外国民族医学   9篇
外科学   2507篇
综合类   3441篇
现状与发展   8篇
预防医学   1143篇
眼科学   165篇
药学   1110篇
  2篇
中国医学   212篇
肿瘤学   2832篇
  2024年   16篇
  2023年   273篇
  2022年   400篇
  2021年   709篇
  2020年   561篇
  2019年   560篇
  2018年   586篇
  2017年   557篇
  2016年   566篇
  2015年   634篇
  2014年   1028篇
  2013年   1107篇
  2012年   960篇
  2011年   1215篇
  2010年   978篇
  2009年   996篇
  2008年   1056篇
  2007年   1204篇
  2006年   1086篇
  2005年   1061篇
  2004年   913篇
  2003年   790篇
  2002年   836篇
  2001年   743篇
  2000年   645篇
  1999年   576篇
  1998年   542篇
  1997年   516篇
  1996年   437篇
  1995年   338篇
  1994年   380篇
  1993年   331篇
  1992年   260篇
  1991年   221篇
  1990年   262篇
  1989年   165篇
  1988年   161篇
  1987年   119篇
  1986年   104篇
  1985年   183篇
  1984年   132篇
  1983年   91篇
  1982年   86篇
  1981年   75篇
  1980年   59篇
  1979年   49篇
  1978年   35篇
  1977年   23篇
  1976年   23篇
  1974年   4篇
排序方式: 共有10000条查询结果,搜索用时 718 毫秒
991.
992.
993.
994.
995.
996.
ObjectiveTo test the hypothesis that sexual dysfunction in elderly men with benign prostatic hyperplasia leads to prostatic inflammation, diagnosed by prostatic fluid interleukin-8 (IL-8), which lowers the positive predictive value of prostate-specific antigen (PSA).MethodsOverall, 160 men with lower urinary tract symptoms between 50 and 75 years of age with an elevated PSA level of more than 4 ng/ml with normal digital rectal examination and 50 age-matched controls with normal PSA level were prospectively evaluated for prostatic fluid IL-8 levels. Erectile dysfunction was measured by self-administered questionnaire of the Sexual Health Inventory for Men. Total and free serum PSA levels and IL-8 in prostatic fluid were measured 6 to 8 weeks after a course of 400 mg of ofloxacin and 20 mg of piroxicam given daily for 2 weeks. Transrectal ultrasonography–guided biopsy was done only when PSA level did not decrease less than 4 ng/ml.ResultsMean ages of patients and controls were 63.18 (standard deviation [SD]±7.10) and 60.18 (SD+6.02) years, respectively. Mean concentration of IL-8 in prostatic fluid of the patients was significantly higher, i.e., 6678 pg/ml (SD±1985.7) than in control, i.e., 1543 pg/ml (SD±375.7) (P<0.001). Following anti-inflammatory treatment, there was a significant decrease in the mean level of IL-8 from baseline to 5622 pg/ml (SD±1870.66) (P<0.001). Corresponding to this, a significant decrease was noted in total PSA levels to less than 4 ng/ml in 105 (65.62%) patients. Men with the highest levels of IL-8 had a greater degree of erectile dysfunction.ConclusionMen with symptomatic benign prostatic hyperplasia and erectile dysfunction had significant inflammation of the prostate to cause spurious rise in PSA level resulting in an unnecessary biopsy.  相似文献   
997.
ObjectivesIn patients with a rising prostate-specific antigen (PSA) level during treatment with androgen deprivation therapy, identification of men who progress to bone metastasis and death remains problematic. Accurate risk stratification models are needed to better predict risk for bone metastasis and death among patients with castration-resistant prostate cancer (CRPC). This study evaluates whether alkaline phosphatase (AP) kinetics predicts bone metastasis and death in patients with CRPC.Methods and materialsA retrospective cohort study of 9,547 patients who underwent treatment for prostate cancer was conducted using the Center for Prostate Disease Research Multi-center National Database. From the entire cohort, 347 were found to have CRPC and, of those, 165 had 2 or more AP measurements during follow-up. To determine the AP velocity (APV), the slope of the linear regression line of all AP values was plotted over time. Rapid APV was defined as the uppermost quartile of APV values, which was found to be ≥6.3 IU/l/y. CRPC was defined as 2 consecutive rising PSA values after achieving a PSA nadir<4 ng/ml and documented testosterone values less than 50 ng/dl. The primary study outcomes included bone metastasis–free survival (BMFS) and overall survival (OS).ResultsRapid APV and PSA doubling time (PSADT) less than 10 months were strong predictors of both BMFS and OS in a multivariable analysis. Faster PSADT was a stronger predictor for BMFS (odds ratio [OR] = 12.1, P<0.0001 vs. OR = 2.7, P = 0.011), whereas rapid APV was a stronger predictor of poorer OS (OR = 5.11, P = 0.0001 vs. OR = 3.98, P = 0.0034). In those with both a rapid APV and a faster PSADT, the odds of developing bone metastasis and death exceeded 50%.ConclusionAPV is an independent predictor of OS and BMFS in patients with CRPC. APV, in conjunction with PSA-based clinical parameters, may be used to better identify patients with CRPC who are at the highest risk of metastasis and death. These findings need validation in prospective studies.  相似文献   
998.
ObjectivesIn May 2012, United States Preventive Services Task Force (USPSTF) finalized its recommendation against prostate-specific antigen (PSA) screening in all men. We aimed to assess trends in PSA screening frequency amongst primary care physicians (PCPs) surrounding the May 2012 USPSTF recommendation.Methods and materialsThe electronic data warehouse was used to identify men aged between 40 and 79 years with no history of prostate cancer or urology visit who were evaluated by an internal medicine or family practice physician between 2007 and 2012. Analyses were directed toward PSA testing within 6-month time period from June to November, with particular focus on the 2011 (pre-USPSTF recommendation) and 2012 (post-USPSTF recommendation) cohorts. The primary outcome measure was proportion of men with at least 1 PSA test during the 6-month pre- and post-USPSTF recommendation periods.ResultsA total of 112,221 men met inclusion criteria. There was a significant decrease in screening frequency between the 2011 and 2012 cohorts (8.6% vs. 7.6%, P = 0.0001; adjusted odds ratio 0.89, 95% confidence interval 0.83–0.95). This decrease was most evident amongst patients aged 40 to 49 years (5.6% vs. 4.6%, P = 0.004) and 70 to 79 years (7.9% vs. 6.2%, P = 0.01). A significant decrease was also observed in patients with highest previous PSA value<1.0 (P<0.0001) and 1.0 to 2.49 ng/ml (P = 0.0074).ConclusionsSince the USPSTF recommendation was finalized, there is evidence of continuing decreases in PSA testing by PCPs. PCPs may be shifting toward more selective screening practices, as decreases in screening are most pronounced in the youngest and oldest patients and in those with history of PSA values<2.5 ng/ml.  相似文献   
999.
Use of intermittent androgen‐deprivation therapy (IADT) in patients with prostate cancer has been evaluated in several studies, in an attempt to delay the development of castration resistance and reduce side‐effects associated with ADT. However it is still not clear whether survival is adversely affected in patients treated with IADT. In this review, we explore the available data in an attempt to identify the most suitable candidate patients for IADT, and discuss factors that may inform appropriate patient stratification. ADT is first‐line treatment for advanced/metastatic prostate cancer and is also recommended for use with definitive radiotherapy for high‐risk localised prostate cancer. The changes in hormone levels induced by ADT can lead to short‐ and long‐term side‐effects which, although treatable in most cases, can significantly reduce the tolerability of ADT treatment. IADT has been investigated in several phase II and phase III studies in patients with locally advanced or metastatic prostate cancer, in an attempt to delay time to tumour progression and reduce the side‐effect burden of ADT. In selected patient groups IADT is no less effective than continuous ADT, ameliorating the impact of ADT‐related side‐effects, and, to a degree, their impact on patient health‐related quality of life (HRQL). Further comparative study is required, particularly in relation to HRQL and long‐term complications associated with ADT.  相似文献   
1000.
目的 将国产乙型肝炎病毒前S1抗原化学发光检测试剂与ELISA试剂进行临床比对评价.方法 收集临床乙肝患者的血清标本452份,分别用乙型肝炎病毒前S1抗原化学发光检测试剂与ELISA试剂进行检测.与ELISA试剂比对,计算化学发光检测试剂的特异度、灵敏度以及总符合率.并计算Kappa值,比较二者结果一致性.结果 与ELISA试剂比对,化学发光检测试剂的特异度为99.4%,灵敏度为100%,总符合率为99.8%,Kappa值为0.995,一致性强度为最强.结论 快速、特异、敏感的前S1抗原化学发光免疫检测试剂适合在临床上推广应用.  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