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   540篇
  免费   32篇
  国内免费   19篇
儿科学   37篇
妇产科学   14篇
基础医学   61篇
口腔科学   8篇
临床医学   72篇
内科学   75篇
皮肤病学   13篇
神经病学   36篇
特种医学   112篇
外科学   76篇
综合类   10篇
预防医学   21篇
眼科学   9篇
药学   17篇
中国医学   2篇
肿瘤学   28篇
  2020年   5篇
  2019年   7篇
  2018年   10篇
  2017年   5篇
  2016年   6篇
  2015年   8篇
  2014年   10篇
  2013年   14篇
  2012年   9篇
  2011年   15篇
  2010年   15篇
  2009年   23篇
  2008年   14篇
  2007年   23篇
  2006年   11篇
  2005年   8篇
  2004年   4篇
  2003年   11篇
  2002年   10篇
  2001年   12篇
  2000年   6篇
  1999年   11篇
  1998年   31篇
  1997年   39篇
  1996年   28篇
  1995年   18篇
  1994年   17篇
  1993年   17篇
  1991年   6篇
  1990年   11篇
  1989年   23篇
  1988年   14篇
  1987年   13篇
  1986年   11篇
  1985年   12篇
  1984年   7篇
  1983年   8篇
  1982年   7篇
  1980年   11篇
  1977年   7篇
  1976年   7篇
  1975年   7篇
  1974年   8篇
  1973年   11篇
  1972年   5篇
  1970年   4篇
  1969年   5篇
  1968年   3篇
  1967年   7篇
  1966年   3篇
排序方式: 共有591条查询结果,搜索用时 45 毫秒
71.
72.
73.
Various mucocutaneous reactions have been reported with the use of systemic docetaxel. We describe a 47-year-old man who developed a persistent serpentine supravenous hyperpigmented eruption (PSSHE), beginning at the site of docetaxel injection and spreading along the superficial venous network in the anterior aspect of the right forearm and distal arm. The eruption occurred after the first infusion of docetaxel following insufficient venous washing. A second infusion was administered through a vein in the other forearm, but this time, abundant venous washing was performed and a similar eruption did not occur. To our knowledge, this is the second report of docetaxel-induced supravenous discoloration and we discussed the terminology and mechanism of this unique reaction.  相似文献   
74.
When performing skin biopsy using the skin biopsy punch, it is recommended that Terson lens capsule forceps be used as an aid to avoid crush artifact. This is because secure yet gentle purchase of the specimen is allowed by a row of small inwardly directed tines that arise from the 2.5 mm horizontally placed grasping blades, which are inserted into the incision created by a 3mm biopsy punch. The instrument also has the extra advantages of being in the correct working position when held with the hand in the resting position between prone and supine, of allowing an uninterrupted line of vision to the wound during use and is of a shape that minimizes unintentional contact with tissue.  相似文献   
75.
The mode of inheritance of insufficient phenytoin p-hydroxylation was studied in the family of a patient who had previously suffered from a phenytoin intoxication caused by insufficient metabolism of this drug. This family was compared with a control group. The rate of phenytoin metabolism was derived from the phenytoin/metabolite ratio in serum 6 hours after an oral test dose of 300 mg phenytoin. The propositus, a brother and a sister, were very slow metabolizers of phenytoin, with a metabolic ratio of approximately 20. In the other individuals, 22 family members of the second generation and 37 control subjects, a metabolic ratio of 4.7 +/- 2.2 (mean +/- SD; n = 59) was found. When comparing the members of the second generation (F2) with the control group, two statistically significantly different groups appear to exist: F2, with a metabolic ratio of 6.6 +/- 1.7 (mean +/- SD; n = 22), and the control group, with a metabolic ratio of 3.7 +/- 1.8 (mean +/- SD; n = 37) (p less than 0.001). Based on these results the mode of inheritance of this defect seems to be autosomal recessive.  相似文献   
76.
目的:跟踪测试优秀女子赛艇运动员比赛前后血乳酸、血尿素及血清肌酸激酶的变化,探讨女子赛艇运动员机体能量物质代谢和赛后疲劳恢复的特点。方法:选取2005-07/09湖北省水上运动中心优秀女子运动员14名,其中国家健将级运动员7名,国家一级运动员7名;平均年龄(22±4)岁,训练年限(4.1±1.4)年,身高(174.2±3.1)cm,体质量(68.6±4.7)kg。14名运动员分别于2000m划艇比赛当日晨空腹、赛前15min、赛后5min,1h及24h抽取指尖血60μL,进行血乳酸、血尿素、血清肌酸激酶检测。结果:14名运动员全部进入结果分析。①比赛前后运动员血乳酸水平的变化:运动员空腹血乳酸水平为(1.22±0.45)mmol/L,赛前15min为(2.89±0.49)mmol/L。赛后5min血乳酸浓度高达(11.51±1.72)mmol/L,与空腹水平比较差异有显著性意义(t=3.077,P<0.01)。赛后24h血乳酸浓度显著下降至(1.76±0.24)mmol/L,与空腹水平基本接近(t=0.027,P>0.05)。②比赛前后运动员血尿素水平的变化:与空腹血尿素水平比较,运动员赛后5min血尿素浓度明显升高[(5.45±0.47),(6.13±1.00)mmol/L;t=2.416,P<0.05]。赛后24h血尿素浓度下降至(5.94±0.85)mmol/L,仍高于空腹水平(t=2.682,P<0.05)。③比赛前后运动员血清肌酸激酶活性的变化:与赛前比较,运动员赛后5min血清肌酸激酶活性明显升高[(3.38±1.58),(6.13±3.25)nkat/L;t=4.968,P<0.01]。赛后1h血清肌酸激酶活性开始下降,至赛后24h与赛前基本相似(t=1.537,P>0.05)。结论:①赛后5min血乳酸、血尿素、血清肌酸激酶活性显著高于赛前,赛后1h血乳酸消除迅速,但仍未恢复到正常水平。提示赛艇是一种以糖酵解系统为主、无氧 有氧代谢混合型供能的运动项目。②赛艇比赛使酸性产物生成增多,血乳酸、血尿素、血清肌酸激酶可作为运动强度和机能恢复的指标。③赛艇比赛后至少24h内,机体处于蛋白质降解增强状态,建议恢复期增加饮食糖和蛋白质摄入量,以促进合成代谢,加快功能恢复过程。  相似文献   
77.
A murine hybridoma clone is described that grows continuously in culture and produces a monoclonal antibody we have called Royal Free Monoclonal Antibody to factor IX No. 1 (RFF-IX/1). This has high affinity for a coagulation site on factor IX. RFF-IX/1 immobilised on sepharose can be used to deplete factor IX from normal human plasma. This immunoaffinity depleted plasma is indistinguishable from severe Christmas disease plasma and can be used as the substrate in a one stage coagulation assay for factor IX. The affinity column has high capacity and can be regenerated so that large scale production from normal plasma of factor IX deficient plasma as a diagnostic reagent is now feasible.  相似文献   
78.
Hasan  AA; Cines  DB; Ngaiza  JR; Jaffe  EA; Schmaier  AH 《Blood》1995,85(11):3134-3143
An important biologic function of high-molecular-weight kininogen (HK) is to deliver bradykinin (BK) to its cellular receptors. Internalization and degradation of HK may provide a mechanism by which endothelial cells modulate the production of BK and control its activities. Therefore, we investigated the binding and subsequent distribution of biotinylated-HK (biotin-HK) associated with human umbilical vein endothelial cells (HUVEC). HUVEC bound 3 to 4 times more HK and with greater avidity at 1 to 3 hours at 37 degrees C than at 4 degrees C (Bmax = 1.0 +/- 0.02 x 10(7) molecules/cell, kd = 7 +/- 3 nmol/L v Bmax = 2.6 +/- 0.2 x 10(6) molecules/cell, kd = 46 +/- 8 nmol/L). However, there was no evidence that the difference was caused by internalization of HK at the higher temperature. First, the same amount of biotin-HK was associated with nonpermeabilized and permeabilized HUVEC using buffers containing 20 to 50 mumol/L zinc ion in the absence or presence of 2 mmol/L calcium ion. Second, binding of biotin-HK to HUVEC was approximately 92% reversible at 1 hour when the cells were maintained at both 37 degrees C and 4 degrees C. Third, neither chloroquine nor primaquine altered the amount of biotin-HK bound to HUVEC. Fourth, biotin-HK bound to HUVEC was almost completely removed by pronase. Fifth, the nonpermeable dye, crystal violet, almost completely quenched the fluorescence signal emitted by HUVEC-associated fluorescein isothiocyanate (FITC) HK. Finally, the localization of HUVEC-bound FITC-HK was restricted to the membrane as shown by laser scanning confocal microscopy. The expression of HK binding sites had an absolute requirement for metabolic energy, but was not dependent on new protein synthesis. Membrane-bound HK contributed to the anticoagulant nature of endothelial cells by blocking human alpha-thrombin binding and its resultant induction of prostacyclin formation. These studies indicate that HK is not internalized by HUVEC, but remains primarily on cell surfaces to be accessible for BK liberation and to modulate the binding and actions of alpha-thrombin.  相似文献   
79.
Schmaier  AH; Smith  PM; Purdon  AD; White  JG; Colman  RW 《Blood》1986,67(1):119-130
High mol wt kininogen (HMWK), the major cofactor-substrate of the contact phase of coagulation, is contained within and secreted by platelets. Studies have been performed to localize platelet HMWK in both the unstimulated and activated platelet and to ascertain the effect of platelet enzymes on HMWK itself. On platelet subcellular fractionation, platelet HMWK was localized to alpha-granules, and platelets from a patient with a deficiency of these granules (gray platelet syndrome) had 28% normal platelet HMWK. Platelet HMWK, in addition to being secreted from the platelet, was also localized to the surface of the platelet when activated. Using a competitive enzyme- linked immunosorbent assay for HMWK as an indirect antibody consumption assay, the external membrane of thrombin-activated platelets as well as the releasate from these stimulated platelets had 17 ng HMWK antigen/10(8) platelets available, whereas unstimulated platelets and their supernatant had only 4.9 and 4.2 ng HMWK/10(8) platelets present, respectively. The anti-HMWK antibody consumption by activated normal platelets was specific for membrane-expressed platelet HMWK, since activated platelets from a patient with total kininogen deficiency did not adsorb the anti-HMWK antibody. Enzymes in the cytosolic fraction of platelets cleaved 125I-HMWK (mol wt 120,000) into a mol wt 100,000 polypeptide as well as smaller products at mol wt 74,000, mol wt 62,000, mol wt 47,000, and a few components below mol wt 45,000. No cleavage products were observed when DFP and leupeptin were present. The cleavage of HMWK was specifically prevented by inhibitors of calcium-activated cysteine proteases (leupeptin, N-ethylmaleimide, iodoacetamide, and EDTA) but not by inhibitors of serine proteases (DFP, benzamidine, soybean trypsin inhibitor, or aprotinin). Platelet cytosol increased the coagulant activity of exogenous purified HMWK with maximum HMWK coagulant activity (35-fold) occurring within ten minutes of exposure to platelet cytosol. Treatment of platelet cytosol with leupeptin prevented the increase in the coagulant activity of exogenous HMWK. These studies indicate that activated platelets express platelet HMWK on their external membrane and platelet enzymes can cleave and increase the coagulant activity of exogenous HMWK.  相似文献   
80.
Human myeloperoxidase gene expression in acute leukemia   总被引:2,自引:0,他引:2  
Zaki  SR; Austin  GE; Swan  D; Srinivasan  A; Ragab  AH; Chan  WC 《Blood》1989,74(6):2096-2102
  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