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   620篇
  免费   37篇
  国内免费   7篇
耳鼻咽喉   2篇
儿科学   30篇
妇产科学   1篇
基础医学   57篇
口腔科学   33篇
临床医学   68篇
内科学   137篇
皮肤病学   17篇
神经病学   9篇
特种医学   103篇
外科学   59篇
综合类   24篇
预防医学   41篇
眼科学   4篇
药学   52篇
中国医学   1篇
肿瘤学   26篇
  2021年   15篇
  2020年   5篇
  2019年   5篇
  2018年   9篇
  2017年   4篇
  2016年   12篇
  2015年   13篇
  2014年   12篇
  2013年   30篇
  2012年   29篇
  2011年   12篇
  2010年   27篇
  2009年   26篇
  2008年   11篇
  2007年   10篇
  2006年   20篇
  2005年   15篇
  2004年   8篇
  2003年   13篇
  2002年   13篇
  2001年   10篇
  2000年   14篇
  1999年   22篇
  1998年   37篇
  1997年   25篇
  1996年   21篇
  1995年   13篇
  1994年   22篇
  1993年   23篇
  1992年   8篇
  1991年   7篇
  1990年   9篇
  1989年   20篇
  1988年   16篇
  1987年   13篇
  1986年   19篇
  1985年   9篇
  1984年   10篇
  1983年   6篇
  1982年   9篇
  1981年   12篇
  1980年   12篇
  1978年   5篇
  1977年   5篇
  1976年   9篇
  1975年   3篇
  1974年   5篇
  1972年   2篇
  1966年   2篇
  1955年   1篇
排序方式: 共有664条查询结果,搜索用时 15 毫秒
71.
Addition of prostaglandins of the E series (PGE1, PGE2) in methylcellulose cultures of murine marrow results in a dose-dependent inhibition of the cloning efficiency of both BFU-E and CFU-C. However, CFU-E growth is unaffected. The inhibitory action of PGE is progressively overcome by increasing amounts of colony-stimulating factor (CSF), and with some limitations, also of erythropoietin (Ep). Addition of PGF2 alpha' associated or not with indomethacin, does not exert any significant effect on these hemopoietic precursors. In an attempt to unvail the mechanism(s) underlying these phenomena, dibutyryl-cyclic AMP (db-cAMP), theophylline (an inhibitor of phosphodiesterase), or theophylline + PGE were plated at various concentrations. Both db-cAMP and theophylline induce an inhibitory influence on both BFU-E and CFU-C growth, which mimicks that by PGEs; additionally, theophylline potentiates the inhibitory action of PGE1. In all these studies, the CFU-E number was not significantly modified. PGE action on BFU-E proliferation is clearly species-dependent, since PGE1 addition to human marrow methylcellulose cultures induces a significant enhancement of the number of both BFU-E and CFU-E derived colonies. This action was abolished upon removal of adherent cells, thus suggesting that PGE1 evokes a release of factor(s) enhancing human erythroid colony growth by adherent cells.  相似文献   
72.
A canine model of hemophilic (factor VIII:C deficiency) bleeding   总被引:8,自引:4,他引:8  
Giles  AR; Tinlin  S; Greenwood  R 《Blood》1982,60(3):727-730
A model of bleeding due to clotting factor deficiency has been developed in dogs. Normal and hemophilic (factor VIII:C deficient) animals were used. Bleeding was induced in lightly anesthetized animals by severing the apex of the nail cuticle using a guillotine device. In normal animals, bleeding usually ceased spontaneously after 2-8 min. In contrast, in hemophilic animals, bleeding continued for up to 20 min and necessitated either cauterization or the application of topical thrombin to achieve hemostasis. Pretreatment of the hemophilic animals with canine cryoprecipitate corrected the cuticle bleeding time to within the range noted for normal animals. The method is simple and reproducible and has the advantage that a number of observations can be made sequentially on the same animal. Rebleeding of the cauterized cuticle of the hemophilic animals did not usually occur. This model has considerable potential for the preclinical testing of products considered to bypass or replace factor VIII:C in patients with acquired inhibitors of factor VIII:C and may be adapted to the study of other mechanisms involved in normal and abnormal hemostasis.  相似文献   
73.
Telischi  M; Patel  AR; Zafar  M; Hoiberg  R 《Blood》1977,50(4):743-748
Since microaggregates have been implicated in posttransfusion pulmonary insufficiency, their elimination has become an active concern in blood transfusion. Various types of filters, as well as frozen-preserved erythrocytes, have been used to provide blood relatively low in microaggregates. We have counted particles in frozen-stored blood before deglycerolization, after washing in each of three cell processing systems, and after filtration through a 40-micrometer filter. Washing frozen erythrocytes reduced the total particle counts by an average of 89%. Slight differences were found among the three blood processors with respect to particle removal. Passing washed blood through a 40-micrometer filter did not result in significant further reduction in particle counts. Hence, the use of such filters in a frozen-preserved blood system is not warranted.  相似文献   
74.
75.
Purpose.?The aim of the study was to evaluate which factors are associated with the use of healthcare a long time after severe burn injury.

Method.?After a review process based on clinical reasoning, 69 former burn patients out of a consecutive group treated at the Uppsala Burn Unit from 1980?–?1995 were visited in their homes and their use of care and support was assessed in a semi-structured interview. Post-burn health was assessed with the Burn-Specific Health Scale-Brief (BSHS-B) and personality was assessed with the Swedish universities Scales of Personality (SSP).

Results.?The participants were injured on average eight years previously. Thirty-four had current contact with healthcare due to their burn injury and had significantly lower scores on three BSHS-B-domains: Simple Abilities, Work and Hand function, and significantly higher scores for the SSP-domain Neuroticism and the SSP-scales Stress Susceptibility, Lack of Assertiveness, and lower scores for Social Desirability. There was no relation to age, gender, time since injury, length of stay, or to the surface area burned.

Conclusions.?A routine screening of personality traits as a supplement to long-term follow-ups may help in identifying the patient's need for care.  相似文献   
76.
77.
自1994年以来,我院采用改良的尿道拖人术治疗外伤性后尿道狭窄22例,取得满意疗效,现报道如下。l临床资料本组病例均为男性,为严重车祸伤或高处跌伤致骨盆骨折所致,年龄则一46岁,平均35岁。临床症状有尿道四溢血、尿摊留、腹胀、肛周青紫肿胀,有休克者2例,合并直肠损伤2例,磅眈破裂6例。术中发现前列腺尖游离者4例。所有病例不能将导尿管插入膀跳,而均行单纯“耻骨上膀胜造疾术”,有膀脱破裂者行“膀脱破裂修补术”,有直肠损伤者,行“乙状结肠造疫术”。患者于术后3-6个月来院行尿道重建术。术前常规尿道造影,显示膜部尿道狭…  相似文献   
78.
High serum fluoride (F-) in patients with chronic renal failure (CRF) and end-stage renal disease (ESRD) is associated with risk of renal osteodystrophy and other bone changes. This study was done to determine F- in normal healthy controls and patients with ESRD on haemodialysis (HD) or peritoneal dialysis (PD). Seventeen healthy controls (12 males, 5 females) and 39 ESRD patients on dialysis (17 males, 22 females) were recruited in the study in a community with 47.4 +/- 3.28 microM/l (range 44-51 microM/l) of F- content in drinking water. Control subjects showed a mean serum F- concentration of 1.08 +/- 0.350 microM/l. Males in control group showed slightly higher F- levels (1.15 +/- 0.334, range 0.55-1.9 microM/l) than females (0.92 +/- 0.370, range 0.6-1.5 microM/l). Mean serum F- concentration did not correlate significantly with age and sex among control subjects, whereas such correlation was observed in patients with ESRD on dialysis. Mean serum F- concentration was significantly higher in patients on dialysis (2.67 +/- 1.09, range 0.8-5.2 microM/l) than normal controls. When grouped according to sex, the mean serum F- concentration in males (3.05 +/- 1.04, range 1.8-5.2 microM/l) was significantly higher than females (2.38 +/- 1.08, range 0.8-5.2 microM/l). When patients were grouped according to age, it was observed that F- concentration was significantly higher in patients with age groups 21-70 (2.86 +/- 1.05) than those with age group 13-20 years (1.42 +/- 0.531). Thus F- concentration correlated with age and sex, being higher in males and above 20 years. Despite appreciable clearance of F- (39-90%) across the peritoneum, patients on CAPD showed higher serum F- concentration than those on HD (3.1 +/- 1.97 vs 2.5 +/- 1.137 microM/l). Of the total 39 patients on dialysis 39% had their serum F- concentration above 3.0 microM/l, posing the risk of renal osteodystrophy.   相似文献   
79.
80.
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