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   1072篇
  免费   85篇
  国内免费   17篇
耳鼻咽喉   3篇
儿科学   81篇
妇产科学   8篇
基础医学   107篇
口腔科学   26篇
临床医学   75篇
内科学   216篇
皮肤病学   27篇
神经病学   25篇
特种医学   132篇
外科学   111篇
综合类   135篇
预防医学   67篇
眼科学   5篇
药学   55篇
中国医学   39篇
肿瘤学   62篇
  2023年   8篇
  2022年   15篇
  2021年   23篇
  2020年   20篇
  2019年   16篇
  2018年   19篇
  2017年   14篇
  2016年   19篇
  2015年   27篇
  2014年   42篇
  2013年   39篇
  2012年   47篇
  2011年   49篇
  2010年   71篇
  2009年   62篇
  2008年   26篇
  2007年   30篇
  2006年   43篇
  2005年   32篇
  2004年   20篇
  2003年   26篇
  2002年   12篇
  2001年   15篇
  2000年   10篇
  1999年   21篇
  1998年   47篇
  1997年   59篇
  1996年   51篇
  1995年   38篇
  1994年   32篇
  1993年   33篇
  1992年   12篇
  1991年   8篇
  1990年   16篇
  1989年   25篇
  1988年   21篇
  1987年   17篇
  1986年   16篇
  1985年   11篇
  1984年   13篇
  1983年   5篇
  1982年   10篇
  1981年   9篇
  1980年   13篇
  1979年   3篇
  1977年   6篇
  1976年   6篇
  1975年   2篇
  1958年   4篇
  1957年   2篇
排序方式: 共有1174条查询结果,搜索用时 15 毫秒
991.
Sarkar  A; Yang  P; Fan  YH; Mu  ZM; Hauptmann  R; Adolf  GR; Stass  SA; Chang  KS 《Blood》1994,84(1):279-286
  相似文献   
992.
Cimo  PL; Gerber  SA 《Blood》1979,54(5):1101-1108
2-Aminoethylisothiouronium bromide (AET) increases the sensitivity of blood cells to complement-mediated immune lysis. We compared the sensitivities of untreated or AET-treated platelets to immune lysis induced by different types of platelet antibody in the 51Cr platelet lysis test. AET platelets were 8-16 times more sensitive to autoantibody and alloantibody, but 8-16 times less sensitive to drug- dependent antibody. AET-platelets bound similar amounts of alloantibody but less drug-dependent antibody, and they lysed at higher complement dilutions than did untreated platelets. AET-platelets detected 10 of 25 autoantibodies, 9 of 9 alloantibodies, and 5 of 8 drug-dependent antibodies. Untreated platelets detected 1 of 25, 6 of 9, and 7 of 8 of these respective platelet antibodies. The use of AET-platelets in the 51Cr platelet lysis test increases its sensitivity for detecting non- drug-dependent platelet antibodies. AET-platelets resemble paroxysmal nocturnal hemoglobinuria (PNH) platelets in their enhanced sensitivity to complement-mediated lysis. They differ from PNH platelets in their insensitivity to immune lysis induced by drug-dependent antibodies and, in this respect, are similar to Bernard-Soulier syndrome platelets.  相似文献   
993.
Riddler  SA; Breinig  MC; McKnight  JL 《Blood》1994,84(3):972-984
Epstein-Barr virus (EBV)-associated posttransplant lymphoproliferative disease (PTLD) is an uncommon but potentially fatal complication of immunosuppression in solid-organ transplant recipients. A semiquantitative DNA polymerase chain reaction assay was developed to amplify a unique 269-bp region of the EBNA-1 gene in peripheral blood lymphocytes (PBL) using the primers described by Telenti et al (J Clin Microbiol 28:2187, 1990). Serial samples were studied from 23 transplant recipients, 12 of whom were diagnosed with PTLD. The majority of transplant recipients who were EBV seropositive at the time of transplant surgery and who did not develop PTLD (5 of 7, 71%) exhibited less than a 10-fold increase in the levels of EBV-infected PBL over the 0.1 to 5 EBV genomes/10(6) PBL observed in immunocompetent EBV seropositive controls. Transplant recipients who were seronegative at the time of transplantation and who underwent a primary EBV infection but did not develop PTLD exhibited a reduced capacity to control viremia because the levels of EBV-infected PBL were up to 400 times greater than the 1.0 to 50 EBV genomes/10(6) PBL observed in individuals undergoing acute infectious mononucleosis (Rocci et al: N Engl J Med 296:132, 1977). However, all transplant recipients who developed PTLD exhibited a marked elevation of EBV-infected PBL independent of their serologic state at the time of transplantation. Six of the 10 transplant recipients with PTLD exhibited > or = 300,000 EBV genomes/10(5) PBL, two exhibited 10,000 to 50,000 EBV-infected genomes/10(5) PBL, and one each exhibited 2,500 and 500 EBV genomes/10(5) PBL. However, the latter two samples were obtained 4 to 5 weeks after the diagnosis of PTLD and may reflect a decrease in viral load resulting from immunomodulation. Marked decreases in the levels of EBV nuclear antigen-1 (EBNA-1), EBNA-2, and EBNA-LP antibodies correlated with the increase in EBV-infected PBL. Hence, a quantitative difference in circulating EBV viral load and EBNA antibody levels is evident between transplant recipients with and without PTLD and may be useful as a noninvasive prognostic marker with which to monitor and/or predict the development of PTLD.  相似文献   
994.
Hoppe  RT; Kushlan  P; Kaplan  HS; Rosenberg  SA; Brown  BW 《Blood》1981,58(3):592-598
Between 1975 and 1978, 51 patients with favorable histology non- Hodgkin's lymphomas, pathologic stage III-IV, were treated prospectively on a randomized treatment protocol. Treatment options were single alkylating agent chemotherapy, combination chemotherapy with cyclophosphamide, vincristine, and prednisone (CVP), or fractionated whole body irradiation followed by low dose involved field irradiation. The median follow-up interval in this group of patients is not 41 mo. Actuarial survival is excellent, 84% at 4 yr for the entire group, with similar survival observed for each of the three treatment options. Initial complete remission rates (64%, 88%, and 71%) were not significantly different in the three treatment arms. Frequent relapse after initial remission induction was noted, however, with a freedom from relapse at 4 yr of only 25%. The toxicities of the three therapies were acceptable. Acute complications of therapy were most numerous in the group of patients treated with CVP; however, long-term hematologic depression was most commonly observed in patients treated with whole body irradiation. In general, hematologic complications were more frequent among patients who had marrow involvement and intact spleens at the time of initial therapy. The relationship of this study to other clinical trials in the management of patients with advanced stage favorable histology lymphomas and its implications for future clinical trials are discussed.  相似文献   
995.
A staphylococcal slide test for detection of antineutrophil antibodies   总被引:1,自引:0,他引:1  
Harmon  DC; Weitzman  SA; Stossel  TP 《Blood》1980,56(1):64-69
We describe a simple test for direct or indrect detection of antineutrophil antibodies. Sensitized leukocytes adherent to glass slides and fixed with paraformaldehyde can be stored in buffer for at least 3 wk. Killed Cowan I staphylococci, containing protein A, bind to sensitized but not control cells, and binding is ascertainable by light microscopy. Indirect tests were positive for 39/41 patients suspected of having immune neutropenia and found to have antineutrophil antibodies by an indirect radiochemical opsonic method. Fifty-four control sera from healthy persons, patients with bone marrow failure, or with immune complex diseases without neutropenia, gave negative indirect tests. Direct tests for cell-bound antibody could be done even during severe neutropenia by reacting fixed autologous cells with staphylococci in the absence of added serum. In some patients only the direct test was positive.  相似文献   
996.

INTRODUCTION

Between 4% and 13% of patients with operable pancreatic malignancy are found unresectable at the time of surgery. Double bypass is a good option for fit patients but it is associated with high risk of postoperative complications. The aim of this study was to identify pre-operatively which patients undergoing double bypass are at high risk of complications and to assess their long-term outcome.

METHODS

Of the 576 patients undergoing pancreatic resections between 2006 and 2011, 50 patients who underwent a laparotomy for a planned pancreaticoduodenectomy had a double bypass procedure for inoperable disease. Demographic data, risk factors for postoperative complications and pre-operative anaesthetic assessment data including the Portsmouth Physiological and Operative Severity Score for the enUmeration of Mortality and morbidity (P-POSSUM) and cardiopulmonary exercise testing (CPET) were collected.

RESULTS

Fifty patients (33 men and 17 women) were included in the study. The median patient age was 64 years (range: 39–79 years). The complication rate was 50% and the in-hospital mortality rate was 4%. The P-POSSUM physiology subscore and low anaerobic threshold at CPET were significantly associated with postoperative complications (p=0.005 and p=0.016 respectively) but they were unable to predict them. Overall long-term survival was significantly shorter in patients with postoperative complications (9 vs 18 months). Postoperative complications were independently associated with poorer long-term survival (p=0.003, odds ratio: 3.261).

CONCLUSIONS

P-POSSUM and CPET are associated with postoperative complications but the possibility of using them for risk prediction requires further research. However, postoperative complications following double bypass have a significant impact on long-term survival and this type of surgery should therefore only be performed in specialised centres.  相似文献   
997.
Objective To investigate the effect of substitutive reconstruction of long urethral stricture on male erectile function. Methods From January 2007 to January 2009, 23 patients with anterior or posterior long urethral stricture were accepted for a variety of onlay substitutive procedures, including lingual mucosa, perputial skin, and mid-scrotal skin. During the follow-up, data from the International Index of Erectile Function-5 (ⅡEF-5) questionnaire and the Quality of Life (QOL) questionnaire as well as maximal flow rate were recorded. All data were compared with those obtained before surgery. Results Significant improvement in QOL (1.22 ± 1.40, 1.82 ± 1. 17,2.07± 0.46) and maximal flow rate (22.46± 4.65, 23.81 ± 6.22, 21.52 ±7.44 ) could be observed 3, 6 and 12 months after surgery compared with those before surgery (5. 22 ± 0. 75, 3. 93 ± 3. 62)(P<0.01). No significant differences in the responses to the ⅡEF-5 questionnaire were observed among all patients during the follow-up (P>0. 05). At the 3, 6 and 12 months after procedure,scores of ⅡEF-5 in patients with anterior urethral stricture ( 17.79 ± 6.42, 16. 57 ± 4. 78, 16.01 ±3.85) were significantly higher than those with posterior urethral stricture (11.67 ± 2.59, 12.35 ±1.83,13. 19±1.67, P<0.05). In patients with posterior urethral stricture, the multiple linear regression showed that age, time interval of injury and length of stricture were related to the ⅡEF-5score (P<0.05). Conclusions Substitutive reconstruction for treating the long urethral stricture has little effect on male erectile function. But the location of stricture, especially extended to posterior urethra, may have impact on the erectile function.  相似文献   
998.
目的探讨甲氨蝶呤序贯米非司酮对剖宫产术后子宫切口妊娠的疗效。方法将2001年1月至2010年12月10年间采取甲氨蝶呤单药治疗患者35例作为A组,甲氨蝶呤序贯米非司酮治疗患者41例作为B组,对治疗效果进行回顾性分析。结果 A组26例治愈,治愈率为74.28%;B组患者38例治愈,治愈率为92.68%,两组患者在治愈率之间比较存在显著性差异,具有统计学意义(P<0.05)。结论采取甲氨蝶呤序贯米非司酮方法治疗剖宫产术后子宫切口妊娠效果满意,疗效优于单纯应用甲氨蝶呤,可作为临床首选治疗方案。  相似文献   
999.
Objective To investigate the effect of substitutive reconstruction of long urethral stricture on male erectile function. Methods From January 2007 to January 2009, 23 patients with anterior or posterior long urethral stricture were accepted for a variety of onlay substitutive procedures, including lingual mucosa, perputial skin, and mid-scrotal skin. During the follow-up, data from the International Index of Erectile Function-5 (ⅡEF-5) questionnaire and the Quality of Life (QOL) questionnaire as well as maximal flow rate were recorded. All data were compared with those obtained before surgery. Results Significant improvement in QOL (1.22 ± 1.40, 1.82 ± 1. 17,2.07± 0.46) and maximal flow rate (22.46± 4.65, 23.81 ± 6.22, 21.52 ±7.44 ) could be observed 3, 6 and 12 months after surgery compared with those before surgery (5. 22 ± 0. 75, 3. 93 ± 3. 62)(P<0.01). No significant differences in the responses to the ⅡEF-5 questionnaire were observed among all patients during the follow-up (P>0. 05). At the 3, 6 and 12 months after procedure,scores of ⅡEF-5 in patients with anterior urethral stricture ( 17.79 ± 6.42, 16. 57 ± 4. 78, 16.01 ±3.85) were significantly higher than those with posterior urethral stricture (11.67 ± 2.59, 12.35 ±1.83,13. 19±1.67, P<0.05). In patients with posterior urethral stricture, the multiple linear regression showed that age, time interval of injury and length of stricture were related to the ⅡEF-5score (P<0.05). Conclusions Substitutive reconstruction for treating the long urethral stricture has little effect on male erectile function. But the location of stricture, especially extended to posterior urethra, may have impact on the erectile function.  相似文献   
1000.
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