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   37809篇
  免费   2886篇
  国内免费   119篇
耳鼻咽喉   364篇
儿科学   1039篇
妇产科学   667篇
基础医学   5477篇
口腔科学   649篇
临床医学   3972篇
内科学   8103篇
皮肤病学   774篇
神经病学   3889篇
特种医学   1389篇
外国民族医学   11篇
外科学   5213篇
综合类   435篇
一般理论   30篇
预防医学   3069篇
眼科学   729篇
药学   2652篇
中国医学   93篇
肿瘤学   2259篇
  2023年   309篇
  2022年   501篇
  2021年   975篇
  2020年   674篇
  2019年   901篇
  2018年   1070篇
  2017年   854篇
  2016年   966篇
  2015年   1017篇
  2014年   1388篇
  2013年   1712篇
  2012年   2693篇
  2011年   2799篇
  2010年   1583篇
  2009年   1309篇
  2008年   2139篇
  2007年   2289篇
  2006年   2180篇
  2005年   1974篇
  2004年   1868篇
  2003年   1573篇
  2002年   1465篇
  2001年   610篇
  2000年   610篇
  1999年   555篇
  1998年   338篇
  1997年   255篇
  1996年   254篇
  1995年   227篇
  1994年   190篇
  1993年   147篇
  1992年   322篇
  1991年   296篇
  1990年   306篇
  1989年   244篇
  1988年   248篇
  1987年   276篇
  1986年   287篇
  1985年   271篇
  1984年   226篇
  1983年   177篇
  1982年   127篇
  1979年   239篇
  1978年   160篇
  1977年   138篇
  1976年   120篇
  1974年   131篇
  1973年   138篇
  1972年   121篇
  1971年   121篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
961.
Infantile pyknocytosis is a rare cause of neonatal jaundice and hemolytic anemia. We report on two cases in twin girls that were diagnosed on peripheral blood smear reading. Pyknocytosis should be considered in cases of early unexplained severe hemolytic anemia, and systematic peripheral smear review performed. Its management consists of phototherapy and RBC transfusion.  相似文献   
962.
Objectives To explore the effect of aging on cardiac toxicity specifically the interaction of age and antipsychotic drugs to alter the QT interval. Methods The Medline databases were searched using the OvidSP platforms with the search strategy: "QT interval" or "QT" and "age" or "aging". The entry criteria were: over 10,000 apparently healthy individuals with data on both sexes; QT interval corrected for heart rate (QTc) and an expression of its variance for multiple age decades extending into the older ages. Results QTc increased in duration with increasing age. Considering a modest one SD increment in QTc in the normal population, the addition of Chlorpromazine produced a QTc on average greater than 450 ms for ages 70 years and older. Risperidone, that did not on average alter QTc, would be expected to produce a QTc of 450 ms in persons in their mid 70 years under some circumstances. QTc prolongation 〉 500 ms with antipsychotic drugs is more likely for persons with QTc initially at the 99th percentile. It may occur with Haloperidol which does not on average alter QTc. Conclusions The range of values for the QT interval in apparently normal older men or women, when combined with the range of expected QT interval changes induced by antipsychotic drugs, can readily be associated with prolonged QTc. Individuals with QTc at the 99th percentile may have serious QTc prolongation with antipsychotic drugs even those that are not usually associated with QTc prolongation.  相似文献   
963.
School‐age children have attracted relatively little attention as a group in need of special measures to protect them against malaria. However, increasing success in lowering the level of malaria transmission in many previously highly endemic areas will result in children acquiring immunity to malaria later in life than has been the case in the past. Thus, it can be anticipated that in the coming years there will be an increase in the incidence of both uncomplicated and severe malaria in school‐age children in many previously highly endemic areas. In this review, which focuses primarily on Africa, recent data on the prevalence of malaria parasitaemia and on the incidence of clinical malaria in African school‐age children are presented and evidence that malaria adversely effects school performance is reviewed. Long‐lasting insecticide treated bednets (LLIN) are an effective method of malaria control but several studies have shown that school‐age children use LLINs less frequently than other population groups. Antimalarial drugs are being used in different ways to control malaria in school‐age children including screening and treatment and intermittent preventive treatment. Some studies of chemoprevention in school‐age children have shown reductions in anaemia and improved school performance but this has not been the case in all trials and more research is needed to identify the situations in which chemoprevention is likely to be most effective and, in these situations, which type of intervention should be used. In the longer term, malaria vaccines may have an important role in protecting this important section of the community from malaria. Regardless of the control approach selected, it is important this is incorporated into the overall programme of measures being undertaken to enhance the health of African school‐age children.  相似文献   
964.
965.
Objectives: Isolated intrahepatic recurrence is noted in up to 40% of patients following curative liver resection for colorectal liver metastases (CLM). The aims of this study were to analyse the outcomes of repeat hepatectomy for recurrent CLM and to identify factors predicting survival.Methods: Data for all liver resections for CLM carried out at one centre between 1998 and 2011 were analysed.Results: A total of 1027 liver resections were performed for CLM. Of these, 58 were repeat liver resections performed in 53 patients. Median time intervals were 10.5 months between the primary resection and first hepatectomy, and 15.4 months between the first and repeat hepatectomies. The median tumour size was 3.0 cm and the median number of tumours was one. Six patients had a positive margin (R1) resection following first hepatectomy. There were no perioperative deaths. Significant complications included transient liver dysfunction in one and bile leak in two patients. Rates of 1-, 3-and 5-year overall survival following repeat liver resection were 85%, 61% and 52%, respectively, at a median follow-up of 23 months. R1 resection at first hepatectomy (P = 0.002), a shorter time interval between the first and second hepatectomies (P = 0.02) and the presence of extrahepatic disease (P = 0.02) were associated with significantly worse overall survival.Conclusions: Repeat resection of CLM is safe and can achieve longterm survival in carefully selected patients. A preoperative knowledge of poor prognostic factors helps to facilitate better patient selection.  相似文献   
966.

Objectives

Total pancreatectomy (TP) is associated with significant morbidity and mortality. The severity of postoperative diabetes and existence of ‘brittle diabetes’ are unclear. This study sought to identify quality of life (QoL) and diabetes-specific outcomes after TP.

Methods

Patients who underwent TP were matched for age, sex and duration of diabetes with patients with type 1 diabetes. General QoL was assessed using the European Organization for Research and Treatment of Cancer (EORTC) core quality of life questionnaire QLQ-C30 and the PAN26 tool. Diabetes-specific outcomes were assessed using the Problem Areas in Diabetes (PAID) tool and an assessment of diabetes-specific complications and outcomes.

Results

A total of 123 patients underwent TP; 88 died (none of diabetic complications) and two were lost to follow-up. Of the remaining 33 patients, 28 returned questionnaires. Fourteen general and pancreas-specific QoL measurements were all significantly worse amongst the TP cohort (QLQ-C30 + PAN26). However, when diabetes-specific outcomes were compared using the PAID tool, only one of 20 was significantly worse. HbA1c values were comparable (P = 0.299), as were diabetes-related complications such as hypoglycaemic attacks and organ dysfunction.

Conclusions

Total pancreatectomy is associated with impaired QoL on general measures compared with that in type 1 diabetes patients. Importantly, however, there was almost no significant difference in diabetes-specific outcomes as assessed by a diabetes-specific questionnaire, or in diabetes control. This study does not support the existence of ‘brittle diabetes’ after TP.  相似文献   
967.
968.
969.
970.
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