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   222210篇
  免费   17771篇
  国内免费   7119篇
耳鼻咽喉   1336篇
儿科学   7678篇
妇产科学   1554篇
基础医学   19554篇
口腔科学   4604篇
临床医学   23493篇
内科学   55951篇
皮肤病学   2746篇
神经病学   26148篇
特种医学   6349篇
外国民族医学   5篇
外科学   16901篇
综合类   30278篇
现状与发展   31篇
一般理论   9篇
预防医学   18716篇
眼科学   2395篇
药学   15285篇
  191篇
中国医学   10053篇
肿瘤学   3823篇
  2024年   656篇
  2023年   4679篇
  2022年   8400篇
  2021年   11887篇
  2020年   11174篇
  2019年   8454篇
  2018年   8376篇
  2017年   8284篇
  2016年   8614篇
  2015年   8320篇
  2014年   15703篇
  2013年   17142篇
  2012年   12821篇
  2011年   13877篇
  2010年   10959篇
  2009年   10509篇
  2008年   10504篇
  2007年   10171篇
  2006年   9064篇
  2005年   7479篇
  2004年   6372篇
  2003年   5481篇
  2002年   4620篇
  2001年   4000篇
  2000年   3327篇
  1999年   2846篇
  1998年   2737篇
  1997年   2417篇
  1996年   2151篇
  1995年   1948篇
  1994年   1799篇
  1993年   1549篇
  1992年   1495篇
  1991年   1309篇
  1990年   1041篇
  1989年   890篇
  1988年   811篇
  1987年   744篇
  1986年   641篇
  1985年   743篇
  1984年   622篇
  1983年   383篇
  1982年   452篇
  1981年   376篇
  1980年   285篇
  1979年   252篇
  1978年   190篇
  1977年   167篇
  1976年   141篇
  1975年   56篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
111.
BackgroundPercutaneous endoscopic gastrostomy (PEG) is required for Levodopa/Carbidopa Intestinal Gel (LCIG) delivery in patients with advanced Parkinson's disease (PD) as well as for enteral feeding in a variety of neurological disorders. Buried Bumper Syndrome (BBS) is a serious complication of PEG. The frequency of BBS in patients receiving LCIG treatment has never been reported.ObjectivesTo compare the frequency of BBS in patients on LCIG treatment or on enteral feeding over the past 12 years and identify possible risk factors.MethodsWe reviewed prospectively recorded data from 2009 to 2020 on two case-series: LCIG-treated PD patients and non-PD patients on enteral nutrition. We identified all BBS incidences. Patients’ characteristics, clinical manifestations, BBS management, possible risk factors and outcomes were analyzed.ResultsDuring the 12 years, 35 PD patients underwent PEG insertion for LCIG infusion, and 123 non-PD patients for nutritional support. There were eight cases of BBS in six PD patients (17.1%). Six of them were effectively managed without treatment discontinuation. Of the enteral feeding patients, only one developed BBS (0.8%) (p < 0.001). We identified inappropriate PEG site aftercare, weight gain, early onset PD, longer survival, treatment duration, dementia and PEG system design as potential risk factors for BBS development.ConclusionsBBS occurs more frequently in LCIG patients than in patients receiving enteral feeding. If detected early, it can be successfully managed, and serious sequalae or treatment discontinuation can be avoided. Regular endoscopic follow-up visits of LCIG-treated patients and increased awareness in patients and clinicians are recommended.  相似文献   
112.
SARS-CoV-2 pandemic has changed across the last 2 years. The development and approval of SARS-CoV-2 vaccines and the emergence of new variants has opened up a new scenario. On this regard, Spanish Society of Nephrology (S.E.N.) Council considers that an update of the previous recommendations should be performed. In the present statement, and taking into account the current epidemiological situation, are included updated recommendations of protection and isolation for patients on dialysis programs.  相似文献   
113.
114.
115.
彭瑶  胡立  蒲虹 《中国热带医学》2019,19(7):696-699
目的 分析HBV患者YKL-40、CA19-9、GP73水平差异及与患者病情轻重程度的相关性,探讨HBV患者病情的判定指标。方法 选取2015年5月—2018年5月收治的100例HBV患者,其中慢性HBV感染组40例、慢性乙型肝炎组36例、HBV相关肝硬化组24例,同期选择我院健康体检的健康者50例作为健康对照组;检测患者血中YKL-40、CA19-9、GP73水平;分析HBV感染患者血清YKL-40、CA19-9、GP73水平与病情轻重程度的相关性。结果 慢性HBV感染、慢性乙型肝炎及HBV相关肝硬化患者血中YKL-40水平分别为(36.38±4.19)ng/mL 、(49.02±4.32)ng/mL、(65.14±5.21)ng/mL ,CA19-9分别为(12.03±1.03)KU/L、(13.84±0.98)KU/L、(16.94±0.81)KU/L,GP73分别为(47.22±5.38)ng/mL 、(98.53±10.24)ng/mL 、(229.85±12.19)ng/mL,均明显高于对照组的(28.19±3.27)ng/mL 、(7.34±0.92)KU/L 、(30.93±3.89)ng/mL,均P=0.000 0。随着慢性HBV感染者、慢性乙型肝炎患者和不同HBV相关肝硬化患者肝脏炎症及纤维化程度加重,患者血中YKL-40、CA19-9和GP73也随之显著增加,均P=0.000 0;YKL-40、CA19-9和GP73均是影响HBV感染患者体内炎症坏死及肝脏纤维化的独立性影响因素,差异有统计学意义(P<0.05)。结论 HBV感染患者血清中YKL-40、CA19-9、GP73水平是HBV感染患者病情轻重程度的独立性影响因素。  相似文献   
116.
ObjectivesAs more countries are implementing measures to address Alzheimer’s disease (AD), it is essential to update the available knowledge on the relationship between economic status and mortality in patients with AD. This study examined the influence of economic status on mortality in Japanese individuals with AD using a medical claims dataset.DesignThis was a retrospective cohort study.Setting and ParticipantsMedical claims data from April 2014 to March 2019 were obtained from 13 local cities participating in the Longevity Improvement and Fair Evidence study. The inclusion criteria were patients aged 65 years and older who were newly diagnosed with AD during the study period.MethodsThe outcome was death during the follow-up period. We assessed economic status by household income (middle to high income and low income); data were obtained from the use of the Medical Expenditure Ceiling Application and Standard Copayment Reduction Card (fee reduction card) when receiving an AD diagnosis, as an indicator of low-income status. We performed multivariate Cox proportional hazards analyses to examine the relationship between economic status and mortality; the model was adjusted for age, sex, the Charlson comorbidity index, and antidementia drug use.ResultsWe identified 39,081 newly diagnosed patients with AD from the Longevity Improvement and Fair Evidence study database (mean age, 83.6 years; female, 67.1%). Of these, 3189 individuals were identified as having a low-income status. After adjusting for possible confounders, low-income status was associated with mortality (hazard ratio, 1.95; 95% confidence interval, 1.84–2.07).Conclusions and ImplicationsLow-income status was associated with substantially poorer prognoses in new AD cases, indicating a need for a thorough examination of medical and nursing care services utilized by low-income individuals with AD and to explore improvement strategies.  相似文献   
117.
118.
难治性胃食管反流病是临床疑难病,症状反复,缠绵难愈,治疗棘手。中医药治疗“反酸”“吞酸”证历久源远,充分挖掘古籍,深研病机,提炼治法,发挥中医药特色,对治疗本病意义深远。  相似文献   
119.
120.
BackgroundCoronary artery bypass grafting (CABG) improves survival in patients with heart failure and severely reduced left ventricular systolic function (LVEF). Limited data exist regarding adverse cardiovascular event rates after CABG in patients with heart failure with midrange ejection fraction (HFmrEF; LVEF > 40% and < 55%).MethodsWe analyzed data on isolated CABG patients from the Veterans Affairs national database (2010-2019). We stratified patients into control (normal LVEF and no heart failure), HFmrEF, and heart failure with reduced LVEF (HFrEF) groups. We compared all-cause mortality and heart failure hospitalization rates between groups with a Cox model and recurrent events analysis, respectively.ResultsIn 6533 veterans, HFmrEF and HFrEF was present in 1715 (26.3%) and 566 (8.6%) respectively; the control group had 4252 (65.1%) patients. HFrEF patients were more likely to have diabetes mellitus (59%), insulin therapy (36%), and previous myocardial infarction (31%). Anemia was more prevalent in patients with HFrEF (49%) as was a lower serum albumin (mean, 3.6 mg/dL). Compared with the control group, a higher risk of death was observed in the HFmrEF (hazard ratio [HR], 1.3 [1.2-1.5)] and HFrEF (HR, 1.5 [1.2-1.7]) groups. HFmrEF patients had the higher risk of myocardial infarction (subdistribution HR, 1.2 [1-1.6]; P = .04). Risk of heart failure hospitalization was higher in patients with HFmrEF (HR, 4.1 [3.5-4.7]) and patients with HFrEF (HR, 7.2 [6.2-8.5]).ConclusionsHeart failure with midrange ejection fraction negatively affects survival after CABG. These patients also experience higher rates myocardial infarction and heart failure hospitalization.  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