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   30876篇
  免费   3544篇
  国内免费   512篇
耳鼻咽喉   183篇
儿科学   897篇
妇产科学   636篇
基础医学   3076篇
口腔科学   455篇
临床医学   4086篇
内科学   2733篇
皮肤病学   174篇
神经病学   1452篇
特种医学   685篇
外国民族医学   2篇
外科学   9431篇
综合类   4283篇
现状与发展   1篇
预防医学   1915篇
眼科学   204篇
药学   2592篇
  39篇
中国医学   1067篇
肿瘤学   1021篇
  2024年   151篇
  2023年   532篇
  2022年   858篇
  2021年   1154篇
  2020年   1212篇
  2019年   1543篇
  2018年   1986篇
  2017年   1090篇
  2016年   1052篇
  2015年   970篇
  2014年   2152篇
  2013年   2203篇
  2012年   1583篇
  2011年   1880篇
  2010年   1630篇
  2009年   1525篇
  2008年   1388篇
  2007年   1295篇
  2006年   1291篇
  2005年   1182篇
  2004年   946篇
  2003年   734篇
  2002年   650篇
  2001年   517篇
  2000年   599篇
  1999年   525篇
  1998年   532篇
  1997年   346篇
  1996年   327篇
  1995年   259篇
  1994年   283篇
  1993年   301篇
  1992年   357篇
  1991年   183篇
  1990年   266篇
  1989年   128篇
  1988年   228篇
  1987年   165篇
  1986年   131篇
  1985年   150篇
  1984年   119篇
  1983年   75篇
  1982年   106篇
  1981年   55篇
  1980年   46篇
  1979年   45篇
  1978年   44篇
  1977年   26篇
  1976年   35篇
  1975年   22篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
输尿管上段结石为临床中常见泌尿系结石类型之一,如不能及时诊治,可引起重度积水、泌尿系感染,甚至脓毒血症,对患者肾功能、健康造成严重影响。随着微创治疗技术在泌尿系结石中应用,微创治疗方法能降低对患者造成治疗性创伤,降低相关并发症发生率,促进患者康复,了解临床中微创治疗输尿管上段结石方法,对临床中合理治疗输尿管上段结石有重要价值。  相似文献   
2.
Introduction: In men, lower urinary tract symptoms (LUTS) are primarily attributed to benign prostatic hyperplasia (BPH). Therapeutic options are targeted to relax prostate smooth muscle and/or reduce prostate enlargement.

Areas covered: This article reviews the major preclinical and clinical data on PDE5 inhibitors with a specific focus on tadalafil. It includes details of the role of the nitric oxide (NO)-cyclic guanosine monophosphate (cGMP) – PDE5 pathway in the LUT organs (bladder and prostate) in addition to the available data on tadalafil in patients with LUTS secondary to BPH with or without erectile dysfunction (ED).

Expert opinion: Preclinical and clinical data have clearly demonstrated that PDE5 inhibitors induce bladder and prostate relaxation, which contributes to the improvement seen in storage symptoms in both animal models of bladder and prostate hypercontractility. Tadalafil is effective both as a monotherapy and add-on therapy in patients with LUTS secondary to BPH. Furthermore, as LUTS-BPH and ED are urological disorders that commonly coexist in aging men, tadalafil is more advantageous than α1-adrenoceptors and should be used as the first option. Tadalafil is a safe and tolerable therapy and unlike α1- adrenoceptors and 5-alpha reductase inhibitors, which can cause sexual dysfunctions, tadalafil improves sexual function.  相似文献   

3.
4.
《Vaccine》2020,38(45):7118-7128
IntroductionToward the Global Vaccine Action Plan 2020 goal, almost 90% of countries have established a National Immunization Technical Advisory Group (NITAG). However, little is known about NITAG's contributions to governance.MethodsIn 2017–2018, a two-step, qualitative retrospective study was conducted. Jordan (JO), Argentina (AR), and South Africa (SA) were selected owing to government-financed NITAGs from middle-income countries (MICs), geographic diversity, and a vaccine introduction with NITAG support. Country case studies were developed, collecting data through desk review and face-to-face key informant interviews (KIIs) from Ministry of Health (MoH) and NITAG. Case studies were analyzed together, to assess governance applying the European Observatory on Health Systems and Policies framework focusing on transparency, accountability, participation, integrity, and policy capacity (TAPIC).ResultsDocument review and 53 KII (22 AR, 20 SA, 11 JO) showed NITAGs played a pivotal role as advisors promoting a culture of evidence-informed policies. NITAGs strengthened governance, although practices varied among countries. Meetings were conducted behind-closed-doors, participation restricted to members, only in one country agendas, and recommendations were public (AR). To increase participation, policy capacity, and transparency, countries considered adding experts in communications, advocacy, and economics. AR and SA contemplated including community members. NITAGs functioned autonomously from the government, with no established internal or external monitoring or supervision. NITAG meeting minutes allowed the review of integrity, adherence to terms of reference, standard operating procedures, and conflict of interest (CoI). For the most part, NITAGs abided by their mandates. Significant issues were related to the level of MoH support and oversight of CoI declaration and documentation.ConclusionsSystematically implementing governance approaches could improve processes, better tailor policies, and implementation. The long-term survival and resilience of NITAGs in these countries showed they play a significant role in strengthening governance. Lessons learned could be useful to those promoting country-driven evidence-informed decision-making.  相似文献   
5.
《Clinical neurophysiology》2020,131(1):259-264
ObjectivesFasciculation potentials (FP) are an important consideration in the electrophysiological diagnosis of ALS. Muscle ultrasonography (MUS) has a higher sensitivity in detecting fasciculations than electromyography (EMG), while in some cases, it is unable to detect EMG-detected fasciculations. We aimed to investigate the differences of FP between the muscles with and without MUS-detected fasciculations (MUS-fas).MethodsThirty-one consecutive patients with sporadic ALS were prospectively recruited and in those, both needle EMG and MUS were performed. Analyses of the amplitude, duration, and number of phases of EMG-detected FPs were performed for seven muscles per patient, and results were compared between the muscles with and without MUS-fas in the total cohort.ResultsThe mean amplitude and phase number of FP were significantly lower in patients with EMG-detected FP alone (0.39 ± 0.25 mV and 3.21 ± 0.88, respectively) than in those with both FP and MUS-fas (1.22 ± 0.92 mV and 3.74 ± 1.39, respectively; p < 0.0001 and p = 0.017, Welch’s t-test).ConclusionSmall FP may be undetectable with MUS. MUS cannot replace EMG in the diagnostic approach for ALS.SignificanceClinicians should use a combination of EMG and MUS for the detection and quantitative analysis of fasciculation in ALS.  相似文献   
6.
PurposeTo determine if cone-beam CT and digital subtraction angiography analysis of pelvic arterial anatomy has predictive value for radiation exposure and technical success of prostatic artery embolization (PAE).Materials and MethodsThis prospective, nonrandomized, single-center study included 104 consecutive patients with lower urinary tract symptoms secondary to benign prostatic hyperplasia. Cone-beam CT was performed in 160/208 (76.9%) hemipelves to determine prostatic artery (PA) origin. Classification of pelvic arterial tortuosity was possible in 73/104 (70.2%) patients. Learning curves of 2 interventionalists who performed 86.5% of PAEs were analyzed.ResultsTortuosity of pelvic arteries was classified as mild in 25 (34.2%) patients median age 64 years, moderate in 40 (54.8%) patients median age 69 years, and severe in 8 (11.0%) patients median age 70 years (mild vs moderate, P = .002; mild vs severe, P = .019); median fluoroscopy times were 24, 36, and 46 minutes (P = .008, P = .023); median contrast volumes were 105, 122.5, and 142 mL (P = .029, P = .064); and bilateral PAE rates were 84.0%, 77.5%, and 62.5% (P = .437), respectively. PA origin from superior vesical artery was most frequent (27.5%) and showed higher dose area product (median 402.4 vs 218 Gy ∙ cm2, P = .033) and fluoroscopy time (median 42.5 vs 27 min, P = .01) compared with PA origin from obturator artery, which was least frequent. Interventionalist experience revealed significant impact on procedure times (median 159 vs 130 min, P = .006).ConclusionsTortuosity of pelvic arteries was more frequent in older patients and predicted worse technical outcomes of PAE. PA origin from obturator artery was associated with lower dose area product and fluoroscopy time, especially compared with PA origin from superior vesical artery. Interventionalist experience showed significant influence on technical outcome.  相似文献   
7.
目的观察循经艾灸预防乳腺癌患者根治术后上肢水肿的效果。方法采用便利抽样法选取乳腺外科乳腺癌根治术的患者150例,随机分为对照组和观察组,每组75例。对照组行常规护理,观察组在对照组基础上在手术侧上肢循经艾灸。于术前1 d、术后第14天和术后1个月,测量两组患者患侧上肢水肿程度。结果观察组术后患侧上肢水肿发生率低于对照组(P<0.05)。结论术后循经艾灸可有效预防乳腺癌根治术后患侧上肢水肿,提高患者舒适度。  相似文献   
8.
9.
10.
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