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   606篇
  免费   22篇
  国内免费   26篇
儿科学   21篇
妇产科学   12篇
基础医学   86篇
口腔科学   27篇
临床医学   86篇
内科学   95篇
皮肤病学   3篇
神经病学   31篇
特种医学   63篇
外科学   92篇
综合类   9篇
预防医学   38篇
眼科学   10篇
药学   51篇
肿瘤学   30篇
  2021年   4篇
  2020年   2篇
  2019年   4篇
  2018年   9篇
  2017年   5篇
  2016年   8篇
  2015年   9篇
  2014年   11篇
  2013年   23篇
  2012年   11篇
  2011年   10篇
  2010年   14篇
  2009年   15篇
  2008年   16篇
  2007年   34篇
  2006年   14篇
  2005年   18篇
  2004年   23篇
  2003年   19篇
  2002年   17篇
  2001年   17篇
  2000年   22篇
  1999年   15篇
  1998年   20篇
  1997年   16篇
  1996年   23篇
  1995年   22篇
  1994年   15篇
  1993年   22篇
  1992年   17篇
  1991年   18篇
  1990年   29篇
  1989年   22篇
  1988年   28篇
  1987年   11篇
  1986年   11篇
  1985年   18篇
  1984年   6篇
  1983年   5篇
  1982年   6篇
  1981年   4篇
  1980年   6篇
  1979年   6篇
  1978年   4篇
  1977年   2篇
  1976年   5篇
  1975年   2篇
  1971年   3篇
  1969年   3篇
  1918年   1篇
排序方式: 共有654条查询结果,搜索用时 31 毫秒
41.
Morphometric analysis was performed on 22 radical prostatectomy specimens of clinical stage A1 and 22 specimens of stage A2 prostate cancers. Of 44 stage A cancers (86%), 38 arose in the transition zone of the prostate, while only 6 were peripheral zone tumors. The subclassification into stages A1 and A2 based on the percentage of cancer in the transurethral resection specimen was not able reliably to separate patients with high-volume stage A cancer from those with low-volume stage A cancer. The same was true when the patients were subclassified according to the criteria of the TNM system (TNM 1987). However, all cases (n = 6) with Gleason grade 4 elements in the TUR chips had relatively high-volume residual TUR cancer (greater than or equal to 1.7 cm3) in the radical specimen. Unsuspected cancers unrelated to the incidental prostate cancer were found in 73% of the specimens. The vast majority (87%) were peripheral zone cancers. Eight unsuspected cancers were larger than the Stage A cancer, but only 2 of the 8 were larger than 1 cm3. Our data suggest that the subclassification of stage A into stages A1 and A2 or the subclassification according to the TNM criteria (TNM 1987) does not reliably separate patients who are at risk of cancer progression. Further diagnostic procedures are necessary in these patients. Post-TUR serum PSA levels (Yang) provided valuable additional information in this series. Post-TUR PSA levels increased with increasing residual cancer volume in the prostate. Below a post-TUR PSA of 1 ng/ml, total residual cancer volume was less than 0.4 cm3 in 7 of 8 cases.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   
42.
Anti-Sc1 was detected in a gravida-2 patient at 12 weeks' gestation. At 29 weeks, the antibody was found to be of the IgG3 subclass with a titer of 16, score 36, by the indirect antiglobulin test, and it produced 7 percent lysis by antibody-dependent cellular cytotoxicity (ADCC) assay, a finding that suggested an unaffected fetus. The titer remained constant throughout the pregnancy, as did the IgG subclass and activity in the ADCC assay. At delivery of the full-term infant, the cord hemoglobin was 13.5 g per dL and the direct antiglobulin test was positive (3+) with anti-IgG. The infant did not require transfusion. A sample taken 9 weeks after delivery showed 44 percent lysis in the ADCC assay. The anti-Sc1 titer was 32, score 65.  相似文献   
43.
新型人工肝--分子吸附再循环系统及其临床应用   总被引:8,自引:0,他引:8  
到目前为止,急慢性重型肝炎的治疗仍强调基础护理和一般的支持对症处理,缺乏清除肝脏毒素和促进肝细胞再生的有效手段。虽然血液透析、灌流和血浆置换已被用于重型肝炎的治疗,但其临床疗效尚未被公认。与上述血液净化方法不同的是,新型人工肝——分子吸附再循环系统在有效清除水溶性中小毒素分子的同时,还可以选择性清除亲脂性及与血浆白蛋白相结合的毒素分子,并保留血液中有用的重要营养物质和蛋白质。本文对这一新型人工肝支持系统的基本原理、使用方法、不良反应及临床应用研究进展作了综述。  相似文献   
44.

Background  

Agitated or violent patients constitute 10% of all emergency psychiatric treatment. Management guidelines, the preferred treatment of clinicians and clinical practice all differ. Systematic reviews show that all relevant studies are small and none are likely to have adequate power to show true differences between treatments. Worldwide, current treatment is not based on evidence from randomised trials. In Brazil, the combination haloperidol-promethazine is frequently used, but no studies involving this mix exist.  相似文献   
45.
In this study, eight institutionalized males received a 0.12% chlorhexidine gluconate spray twice daily. A second group of eight males received a placebo spray in the same manner. The results indicated that pump-administered chlorhexidine spray can effectively reduce plaque and gingivitis in patients with mental retardation who are unable to brush their own teeth  相似文献   
46.
肺源性心脏病急性发作期免疫功能的改变   总被引:3,自引:0,他引:3  
目的:观察肺源性心脏病(简称肺心病)急性发作期患者免疫功能的变化。方法:选择南华大学附属第一医院2004-11/2006-01收治慢性肺心病急性发作期患者60例为肺心病组,于急性加重期入院第2天7:00,空腹抽取静脉血,采用流式细胞仪检测T细胞亚群CD3 、CD4 、CD8 及自然杀伤细胞活性,免疫浊度法检测体液免疫指标(IgG,IgM,IgA及补体C3)。以同期60例健康体检者为对照。结果:120例是否受试者均进入结果分析。①T细胞亚群:肺心病组CD3 ,CD4 水平低于对照组(0.52±0.06,0.62±0.04;0.32±0.06,0.41±0.06;P均<0.05),CD4 /CD8 高于对照组(1.96±0.26,1.84±0.78,P<0.05)。②免疫血清指标:肺心病组IgA、补体C3及自然杀伤细胞活性低于对照组[(1.26±0.74),(2.45±0.85)g/L;(6200±217),(9960±302)mg/L;0.34±0.08,0.57±0.07;P均<0.05]。结论:肺源性心脏病急性发作期患者的细胞免疫和体液免疫功能均受损,尤以细胞免疫功能受损更突出,且与病情呈平行关系。  相似文献   
47.

Study Design

Clinical measurement.

Introduction

Individuals with carpal tunnel syndrome (CTS) sometimes exhibit weakness of palmar abduction strength (TAS). Reliable assessment of this strength in both subjects with and without CTS with the commonly available Microfet 2 is not known.

Purpose of the Study

The purpose of this study was to determine the intrarater and interrater reliabilities of a handheld dynamometric (HHD) method to assess TAS in individuals with and without CTS using the commercially available MicroFET2 and to examine the association between TAS in individuals with CTS and the Carpal Tunnel Symptom Questionnaire (CTSQ) scores.

Methods

In 2 different study phases, individuals with and without CTS were assessed for TAS by 2 different examiners. The CTSQ was administered to the individuals with CTS.

Results

Intrarater and interrater reliability coefficients (0.89-0.93 and 0.82-0.90, respectively) were excellent in individuals with and without CTS. Weak negative correlations were found between TAS and overall CTSQ and symptom severity subscale scores, and a moderate negative correlation was found between TAS and functional Status Subscale score.

Discussion

This HHD method of reliably assessing TAS better quantifies deficits and progress than traditional manual muscle testing for muscle grades greater than 3/5.

Conclusion

This method of HHD reliably quantifies TAS but is more reliable with the same than different raters.  相似文献   
48.
A 7-year-old, 17-kg child with chronic granulomatous disease and nocardial pneumonia and osteomyelitis did not respond to antibiotic therapy and developed multiple red cell (RBC) alloantibodies (anti-c, -E, and -Jka). To provide daily granulocyte concentrates, a method was devised to reduce the number of incompatible RBCs per transfusion. Leukapheresis was done with hydroxyethyl starch, and the apheresis product was allowed to sediment by gravity in a plasma expressor for 90 minutes. The leukocyte-rich plasma was separated from the sedimented RBCs by transfer to a satellite bag, and the volume of the product was reduced by centrifugation to approximately 80 ml. RBC content was reduced from 29 +/- 7 to 2.5 +/- 1.0 ml (n = 22, p less than 0.01) and was accompanied by a 70 percent recovery of white cells (range, 49-90%). The final product contained 1.6 +/- 1.0 X 10(10) granulocytes. There were no clinical or laboratory signs of hemolysis during the course of 46 granulocyte transfusions, 37 of which were derived from c-, E-, or Jka-positive donors. The size of most apheresis donor pools is insufficient to provide phenotypically matched granulocyte concentrates daily for patients with RBC alloimmunization. The rapid, simple method described here may allow daily therapy with mismatched concentrates to be administered safely to such patients.  相似文献   
49.
50.
The effect of prestorage irradiation on posttransfusion red cell survival   总被引:1,自引:0,他引:1  
Transfusion-associated graft-versus-host disease (TA-GVHD) may occur whenever immunologically competent allogeneic lymphocytes are transfused to an immunocompromised recipient. Irradiation of blood components eliminates the risk of TA-GVHD but may damage the cellular elements in the transfused component, particularly if the cells are stored for prolonged periods in the irradiated state. To study the effect of irradiation on long-term storage of red cells, AS-1 red cells from eight normal subjects were prepared on two occasions. On one occasion, the units were stored as standard AS-1 red cells for 42 days at 4 degrees C; on the other, they were exposed to 3000 cGy radiation within 4 hours of collection and then were stored as AS-1 red cells for 42 days at 4 degrees C. The donations were at least 12 weeks apart. Irradiated units demonstrated significant elevations in poststorage plasma hemoglobin (Hb) (623 +/- 206 vs. 429 +/- 194 g/dL [6230 +/- 2060 vs. 4290 +/- 1940 g/L], p less than 0.02) and plasma potassium (78 +/- 4 vs. 43 +/- 9 mEq/L [78 +/- 4 vs. 43 +/- 9 mmol/L], p less than 0.01) and significant decreases in red cell ATP (1.9 +/- 0.2 vs. 2.1 +/- 0.3 microM/g Hb, p less than 0.04) and 24-hour posttransfusion red cell recovery (68.5 vs. 78.4%, p less than 0.02), as compared to nonirradiated units. It can be concluded that irradiation with 3000 cGy damages red cells and that long-term storage in the irradiated state may enhance this damage. Red cells should not be stored for 42 days after irradiation with 3000 cGy.  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