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   45167篇
  免费   1964篇
  国内免费   188篇
耳鼻咽喉   533篇
儿科学   892篇
妇产科学   4094篇
基础医学   5572篇
口腔科学   1073篇
临床医学   5264篇
内科学   7389篇
皮肤病学   673篇
神经病学   3522篇
特种医学   1601篇
外科学   5599篇
综合类   992篇
一般理论   9篇
预防医学   2935篇
眼科学   731篇
药学   3343篇
中国医学   377篇
肿瘤学   2720篇
  2024年   9篇
  2023年   1124篇
  2022年   1574篇
  2021年   1857篇
  2020年   1851篇
  2019年   1271篇
  2018年   1500篇
  2017年   1316篇
  2016年   1306篇
  2015年   1504篇
  2014年   3505篇
  2013年   2813篇
  2012年   2711篇
  2011年   2398篇
  2010年   2579篇
  2009年   2362篇
  2008年   2098篇
  2007年   1960篇
  2006年   1721篇
  2005年   1583篇
  2004年   1396篇
  2003年   1206篇
  2002年   1201篇
  2001年   1168篇
  2000年   1030篇
  1999年   991篇
  1998年   459篇
  1997年   351篇
  1996年   402篇
  1995年   288篇
  1994年   175篇
  1993年   138篇
  1992年   401篇
  1991年   308篇
  1990年   246篇
  1989年   130篇
  1988年   124篇
  1987年   36篇
  1985年   16篇
  1984年   29篇
  1983年   18篇
  1982年   14篇
  1981年   19篇
  1980年   12篇
  1979年   13篇
  1978年   11篇
  1977年   12篇
  1976年   19篇
  1975年   10篇
  1974年   9篇
排序方式: 共有10000条查询结果,搜索用时 437 毫秒
1.
2.
《Clinical therapeutics》2022,44(3):403-417.e6
PurposeEntecavir (ETV) and tenofovir disoproxil fumarate (TDF) are both recommended as first-line treatments for patients with chronic hepatitis B virus (CHB) infection according to international HBV treatment guidelines. However, recent studies reported conflicting results regarding the preferred antiviral in the prevention of hepatocellular carcinoma (HCC). This cohort study aimed to investigate this issue by using Taiwan's National Health Insurance Research Database, wherein a “finite” but not life-long treatment policy was applied.MethodsFrom January 2008 to December 2013, a total of 12,388 consecutive adult patients with CHB who received a finite course of TDF treatment (n = 1250) or ETV treatment (n = 11,138) were analyzed through screening for study eligibility followed by the 1:4 propensity score matching method.FindingsIn the entire cohort, the annual incidence and survival between the ETV and TDF groups were not significantly different regarding HCC occurrence (2.05 vs 2.74 per 100 patient-years [PY]; P = 0.055; hazard ratio [HR], 0.975; log-rank, P = 0.966), cirrhosis-related complications (1.9 vs 2.4 per 100 PY; P = 0.149; HR, 0.869; log-rank, P = 0.388), or all-cause mortality (2.16 vs 1.6 per 100 PY; P = 0.119; HR, 0.831; log-rank, P = 0.342), respectively. Propensity score matching analyses yielded similar results regarding HCC occurrence, cirrhosis-related complications, and all-cause mortality. In addition, these findings were consistently reproduced in the subgroups of patients with chronic hepatitis and cirrhosis that developed before antiviral treatment.ImplicationsETV and TDF did not significantly differ in prevention of HCC occurrence or reduction of cirrhosis-related complications and all-cause mortality in patients with CHB receiving a finite period of treatment.  相似文献   
3.
4.
5.
《Autoimmunity reviews》2022,21(9):103143
Autoimmune diseases (AID) are increasingly prevalent conditions which comprise more than 100 distinct clinical entities that are responsible for a great disease burden worldwide. The early recognition of these diseases is key for preventing their complications and for tailoring proper management. In most cases, autoantibodies, regardless of their potential pathogenetic role, can be detected in the serum of patients with AID, helping clinicians in making a definitive diagnosis and allowing screening strategies for early -and sometimes pre-clinical- diagnosis. Despite their undoubted crucial role, in a minority of cases, patients with AID may not show any autoantibody, a condition that is referred to as seronegative AID. Suboptimal accuracy of the available laboratory tests, antibody absorption, immunosuppressive therapy, immunodeficiencies, antigen exhaustion, and immunosenescence are the main possible determinants of seronegative AID. Indeed, in seronegative AID, the diagnosis is more challenging and must rely on clinical features and on other available tests, often including histopathological evaluation and radiological diagnostic tests. In this review, we critically dissect, in a narrative fashion, the possible causes of seronegativity, as well as the diagnostic and management implications, in several AID including autoimmune gastritis, celiac disease, autoimmune liver disease, rheumatoid arthritis, autoimmune encephalitis, myasthenia gravis, Sjögren’s syndrome, antiphospholipid syndrome, and autoimmune thyroid diseases.  相似文献   
6.
《Explore (New York, N.Y.)》2022,18(6):683-687
Background and aims Electroconvulsive therapy (ECT) is considered a safe, effective, and significant treatment in patients suffering from a major depressive disorder. Anxiety caused by this invasive treatment may impose several side effects on patients. The purpose of this study was to evaluate the effectiveness of aromatherapy with inhaled lavender essential oil and breathing exercises on ECT-related anxiety in depressed patients.Methods In this randomized controlled clinical trial, 90 depressed patients were selected and divided into three groups: aromatherapy, breathing exercise, and routine care using a random allocation method. Before undergoing ECT, the aromatherapy group was exposed to the inhaled lavender essential oil (n = 30), the breathing exercise group performed the breathing exercises (n = 30), and the routine care group received routine care (n = 30). Before (20 min) and after the intervention (30 min later), patients' anxiety was assessed using Beck Anxiety Inventory.Results After the intervention, the results revealed that anxiety score changes were statistically significant among the three groups (p < 0.001). In addition, it was found that the patients’ mean anxiety scores significantly decreased in the aromatherapy and breathing exercise groups compared to with the pre-intervention scores (p < 0.001).Conclusion Aromatherapy with inhaled lavender essential oil and breathing exercises can be considered by clinical nurses as simple, applicable, and effective interventions to reduce ECT-related anxiety in depressed patients.  相似文献   
7.
BackgroundOptimal timing to initiate mechanical circulatory support (MCS) in patients with ST-elevation myocardial infarction (STEMI) complicated by cardiogenic shock (CS) remains unclear with studies showing conflicting results on whether to start before or after primary percutaneous coronary intervention (PPCI). This study aims to examine the association between mortality and MCS initiated before vs after PPCI in patients with STEMI complicated by CS.MethodsWe systematically searched PubMed, Embase, and Scopus for abstracts and full-text articles from inception to October 2021. Studies were included if they evaluated the association of mortality in patients who initiated MCS (specifically intra-aortic balloon pump (IABP), Impella, and venoarterial extracorporeal membrane oxygenation (VA-ECMO)) before PPCI versus after PPCI, specifically in patients with STEMI complicated by CS. Data were integrated using the random-effects models.ResultsTen studies involving 1,352 patients (956, 203, and 193 patients underwent IABP, Impella, and VA-ECMO respectively) with STEMI complicated by CS were included. There was no difference in mortality using IABP before or after PPCI ([OR] 1.77, 95% CI 0.77–1.61, I2 = 27%, p = 0.57). Nevertheless, Impella and VA-ECMO started before PPCI were significantly associated with a reduced risk of mortality compared to that started after PPCI ([OR] 0.49, 95% CI 0.26–0.92, I2 = 0%, p = 0.03 and [OR] 0.29, 95% CI 0.14–0.62, I2 = 0%, p = 0.001, respectively).ConclusionsIn patients with STEMI complicated by CS undergoing PPCI, the use of IMPELLA or VA-ECMO prior to PPCI significantly decreased mortality, in contrast to IABP, in which no difference in mortality was found between using it before or after PPCI. More rigorous studies are needed to clarify this association.  相似文献   
8.
9.
BackgroundPancreatic ductal adenocarcinoma (PDAC) has poor survival. Current treatments offer little likelihood of cure or long-term survival. This systematic review evaluates prognostic models predicting overall survival in patients diagnosed with PDAC.MethodsWe conducted a comprehensive search of eight electronic databases from their date of inception through to December 2019. Studies that published models predicting survival in patients with PDAC were identified.Results3297 studies were identified; 187 full-text articles were retrieved and 54 studies of 49 unique prognostic models were included. Of these, 28 (57.1%) were conducted in patients with advanced disease, 17 (34.7%) with resectable disease, and four (8.2%) in all patients. 34 (69.4%) models were validated, and 35 (71.4%) reported model discrimination, with only five models reporting values >0.70 in both derivation and validation cohorts. Many (n = 27) had a moderate to high risk of bias and most (n = 33) were developed using retrospective data. No variables were unanimously found to be predictive of survival when included in more than one study.ConclusionMost prognostic models were developed using retrospective data and performed poorly. Future research should validate instruments performing well locally in international cohorts and investigate other potential predictors of survival.  相似文献   
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