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   500篇
  免费   20篇
  国内免费   18篇
耳鼻咽喉   1篇
儿科学   23篇
妇产科学   6篇
基础医学   46篇
口腔科学   18篇
临床医学   63篇
内科学   106篇
皮肤病学   3篇
神经病学   26篇
特种医学   131篇
外科学   21篇
综合类   9篇
预防医学   19篇
眼科学   3篇
药学   42篇
肿瘤学   21篇
  2022年   1篇
  2021年   3篇
  2020年   1篇
  2019年   1篇
  2018年   8篇
  2017年   6篇
  2016年   6篇
  2015年   4篇
  2014年   7篇
  2013年   13篇
  2012年   9篇
  2011年   10篇
  2010年   10篇
  2009年   17篇
  2008年   5篇
  2007年   21篇
  2006年   12篇
  2005年   16篇
  2004年   12篇
  2003年   3篇
  2002年   6篇
  2001年   8篇
  2000年   9篇
  1999年   8篇
  1998年   33篇
  1997年   18篇
  1996年   24篇
  1995年   19篇
  1994年   22篇
  1993年   13篇
  1992年   6篇
  1991年   6篇
  1990年   15篇
  1989年   24篇
  1988年   29篇
  1987年   15篇
  1986年   19篇
  1985年   16篇
  1984年   13篇
  1983年   8篇
  1982年   9篇
  1981年   5篇
  1980年   14篇
  1979年   9篇
  1978年   5篇
  1977年   8篇
  1976年   9篇
  1973年   1篇
  1969年   1篇
  1947年   1篇
排序方式: 共有538条查询结果,搜索用时 15 毫秒
101.
102.
There have been publically expressed concerns about the costs and allocation of neonatal and perinatal health care resources in Canada and elsewhere for the past 15 years. This paper reports information from a symposium held during the 1996 Canadian Paediatric Society (CPS) annual meeting sponsored by the CPS Section on Perinatal Medicine. Experts in perinatal epidemiology, health care economics, public policy and finance, and consumer perspectives on the outcomes of neonatal and perinatal intensive care explored the following questions: How should the need for health care resources in the neonatal and perinatal area be objectively determined? When there are competing needs between the maternal-newborn area and other areas, how should these be rationalized? What evidence should be used (or should be available) to support the present use of resources? What evidence should be available (or is needed) to change or introduce new uses of resources? The conclusions indicated that there are no generally accepted methods to determine the allocation of health care resources but that considerations need to include population characteristics, desired outcomes, achievable results, values, ethics, legalities, cost-benefit analyses and political objectives. Information from families and adolescents who required the use of high technology and/or high cost programs will contribute individual, family and societal values that complement cost-efficacy analyses.  相似文献   
103.
自Lane等 1997年详细报道了HSCTGR后 ,一直没有该肿瘤转移潜能的证据 ,该文报道 1例 2 8岁女性右上臂三角肌内HSCTGR(8 7cm× 5 5cm× 4 0cm大小 ) ,术后 4年右肺转移 ,并于 6年后行肺部手术 ,取出 0 6cm~ 1 2cm大小转移性结节 3枚。肿瘤从大体形态到超微结构及免疫组化表现与前文相似。本文总结出该病光镜下由梭形细胞为主 ,构成 3种图像 :①纤维瘤样区 ,为肿瘤的主要成分 ,无核分裂象 ;②细胞区 ,细胞丰富 ,核浓染 ,胶原减少 ,罕见核分裂象 ;③特征性病变 (有诊断意义 ) ,即由丰富细胞核环绕的玻璃样变小体 …  相似文献   
104.
105.
This study aimed to explore the therapeutic mechanism of intravenous immunoglobulin (IVIG) for Kawasaki disease (KD). Peripheral blood lymphocytes (PBLs) obtained from 26 children with KD and 20 age-matched healthy children were stimulated with anti-CD3 monoclonal antibody (mAb), and the percentage of apoptotic cells and DNA fragmentation were assayed at 0, 12, 24, 48 and 72 h in vitro. The patients were divided into two groups: one treated with aspirin combined with IVIG (n = 16) and one treated with aspirin alone (n = 10). PBLs were stimulated by phytohaemagglutinin to evaluate the lymphocyte proliferative response. Compared with normal controls, the apoptotic cell percentage and the DNA fragmentation were markedly decreased (p < 0.001) and delayed in PBLs from KD patients. After IVIG treatment, the decreased percentage of apoptotic cell and delayed DNA fragmentation were restored to the state of the normal controls, accompanied by a fast clinical remission compared with the aspirin-alone group. The lymphocyte proliferative response was also decreased 3-5 d after IVIG therapy (p < 0.001). Conclusion: The results suggest that decreased PBL apoptosis may be involved in the pathogenesis of KD. The therapeutic mechanism of IVIG in KD may be partially due to the reversal of the inhibited lymphocyte apoptosis, and may have implications for other autoimmune diseases with inefficient lymphocyte apoptosis.  相似文献   
106.
Human red cells (RBCs) were collected in CPDA-1 and then freeze-dried in lyoprotective solution. The lyophilized RBCs were then stored at -20 degrees C for 7 days. At the end of the storage period, the lyophilized RBCs were rehydrated and washed in dextrose saline. The washed, reconstituted, lyophilized RBCs were resuspended in final wash solutions of ADSOL, CPDA-1, or a special additive solution containing glucose, citrate, phosphate, adenine, and mannitol, and then they were stored at 4 degrees C for an additional 7 days. The main purpose of this study was to determine whether human RBCs can be lyophilized in such a manner that normal metabolic, rheologic, and cellular properties are maintained during rehydration and subsequent storage in standard blood bank preservative solutions. Our results show that reconstituted, lyophilized RBCs maintained levels of ATP, 2,3 DPG, lactate, and cellular properties that are equal to or better than those in control nonlyophilized RBCs stored for a comparable period in CPDA-1. Reconstituted, lyophilized RBCs stored at 4 degrees C after rehydration also show better maintenance of ATP, 2,3 DPG, and lactate than do control RBCs stored in the same preservative solutions for comparable periods.  相似文献   
107.
Chew  CA; May  CR 《Family practice》1997,14(6):461-465
  相似文献   
108.
羽叶三七叶中甙类成分的研究   总被引:3,自引:0,他引:3  
从羽叶三七叶中分离到十三种甙类成分,经FAB-MS,13CNMR谱,双照射1HN-MR谱,1H-1H COSY谱及与标准品直接对照,证明十一种为已知化合物,分别为人参皂甙F1(Ⅰ),F2(Ⅱ),F3(Ⅲ),Rg2(Ⅳ),Ra(Ⅴ),Rd(Ⅵ),Rb1(Ⅷ),Rb3(Ⅷ),24(S)-假人参甙F11(Ⅸ),人参黄酮(Ⅹ)和珠子参甙F1(Ⅺ);另外两种为新的达玛烷型皂甙,命名为羽叶三七甙F1(Ⅻ)和F2(ⅫⅠ),并确定其化学结构。同时修正珠子参甙F3的结构。进一步阐明人参黄酮甙结构中的两个糖的连接方式。  相似文献   
109.
Incidence of red cell antibodies after multiple blood transfusion   总被引:3,自引:0,他引:3  
A retrospective study was performed to estimate the frequency of alloimmunization against red cell (RBC) antigens in a multiply transfused group. Patients (n = 186) were studied who had received at least six blood transfusions during a period of at least 3 months. Some 6944 units of blood were transfused. One hundred forty patients had hematologic disorders. The patients' sera were investigated every 3 months with indirect antiglobulin tests and enzyme-treated RBCs. Twenty-two patients (11.8%) made 33 antibodies. Seven patients made more than one antibody. Eight of the 22 patients (36.4%) made their first antibody before or at the 10th transfusion. The risk of immunization increased with the number of transfusions. Influence of gender and age was not demonstrable. Nor was a relationship demonstrated between blood transfusion reactions and RBC antibody formation; no delayed hemolytic transfusion reactions occurred. Anti-E was demonstrated in 12 patients and anti-K in 15. When the gene frequencies were taken into account, it appeared that anti-E was made by 11.5 percent of E-negative patients, most of whom were immunized after an estimated three transfusions with E-positive blood. Anti-K was made by 8.7 percent of the K-negative patients, after an estimated 2.1 units of K-positive blood. It might be desirable to match red cell units for the E and K antigens in patients at relatively high risk. These are primarily patients who have already formed an antibody and are going to receive many transfusions and women of childbearing age who are to receive more than 4 units of blood.  相似文献   
110.
We describe a young man who developed extensive hypothalamicdysfunction including diabetes insipidus, adipsia, hyperprolactinaemia,and poikiliothermia together with central sleep apnoea followingexposure to toluene.  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