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   363篇
  免费   8篇
  国内免费   33篇
耳鼻咽喉   1篇
儿科学   11篇
妇产科学   2篇
基础医学   37篇
口腔科学   6篇
临床医学   50篇
内科学   81篇
皮肤病学   4篇
神经病学   10篇
特种医学   4篇
外科学   36篇
综合类   97篇
预防医学   10篇
眼科学   3篇
药学   34篇
中国医学   4篇
肿瘤学   14篇
  2021年   2篇
  2020年   5篇
  2018年   3篇
  2017年   1篇
  2016年   3篇
  2015年   1篇
  2014年   5篇
  2013年   10篇
  2012年   2篇
  2011年   6篇
  2010年   6篇
  2009年   13篇
  2008年   10篇
  2007年   16篇
  2006年   9篇
  2005年   10篇
  2004年   7篇
  2003年   20篇
  2002年   15篇
  2001年   19篇
  2000年   15篇
  1999年   14篇
  1998年   21篇
  1997年   11篇
  1996年   15篇
  1995年   9篇
  1994年   13篇
  1993年   3篇
  1992年   10篇
  1991年   12篇
  1990年   8篇
  1989年   8篇
  1988年   15篇
  1987年   12篇
  1986年   7篇
  1985年   14篇
  1984年   9篇
  1983年   5篇
  1982年   9篇
  1981年   9篇
  1980年   5篇
  1979年   6篇
  1978年   2篇
  1977年   3篇
  1976年   3篇
  1975年   1篇
  1973年   1篇
  1971年   1篇
排序方式: 共有404条查询结果,搜索用时 0 毫秒
11.
作者以健康杂种犬13只,随机分为两组进行实验,并观察60例手术病人,结果提示:测定血清CK-MB活性在心脏直视手术心肌缺血期间可做为评定心肌保护方法的指标之一。  相似文献   
12.
分析血清电解质、肌酸激酶同工酶(CKBB)及血乳酸水平与新生儿缺氧缺血性脑病严重程度的相关性。80例缺氧缺血性脑病患儿中轻度患儿27例、中度患儿26例、重度患儿27例。以本院同期健康的足月新生儿60例为对照组。结果显示与对照组新生儿比较,观察组新生儿氯离子及钙离子水平明显降低(P<0.05),CKBB和血乳酸水平明显升高(P<0.05);重度患儿的氯离子及钙离子水平明显低于中度患儿和轻度患儿(P<0.05),CKBB和血乳酸水平明显高于中度患儿和轻度患儿(P<0.05);血清中氯离子和钙离子与缺氧缺血性脑病严重程度呈现负相关性(P<0.05),但CKBB和血乳酸与缺氧缺血性脑病严重程度呈明显的正相关性(P<0.05)。结果说明血清氯离子和钙离子、CKBB及血乳酸水平与新生儿缺氧缺血性脑病严重程度呈明显的相关性。  相似文献   
13.
An immunoinhibition method for the assay of creatine kinase(CK) isoenzymes by continuous monitoring of the ATP formationin the CK reaction by a purified firefly luciferase reagenthas been developed. The sensitivity of the firefly assay ofATP makes it possible to assay CK-B subunit activity (CK-B)in serum down to 1 U/l. In healthy individuals CK-B varied between 2 and 12, mean 3U/l. A wide range of CK-B activity was observed after acutemyocardial infarction (AMI), intramuscular injection and surgerywith overlapping between these different categories. Thereforethe maximal change in CK-B activity (CK-B) was studied in 98patients admitted to a coronary care unit. In all 57 patientswithout a subsequent diagnosis of AMI according to conventionalcriteria CK-B was < 5 U/l. In all 41 patients with AMI CK-Bwas 5 U/l. In all healthy individuals CK-B was < 2 U/l.CK-B 5 U/l was found after i.m. injection and different kindsof surgery in three out of 60 patients. Thus, the present method for determination of CK activity hasbeen shown to possess high precision in low activities, to beas rapid as conventional methods and to be simple enough tobe used in a routine laboratory. With these properties the methodshould be suited for early diagnosis and early exclusion ofeven very small AMIs.  相似文献   
14.
目的探讨急性心肌梗死(AMI)患者血清可溶性凝集素样氧化型低密度脂蛋白受体-1(sLOX-1)和心肌型肌酸激酶同工酶(CK-MB)水平及意义。方法选取AMI患者120例(AMI组),同时选取健康体检者120例作为对照组,检测血清sLOX-1、CK-MB水平。结果AMI组患者血清sLOX-1、CK-MB水平明显高于对照组(P<0.05);AMI组左室舒张末期容积指数(LVEDVI)、左室收缩末期容积指数(LVESVI)和左室射血分数(LVEF)分别为(73.39±2.29)mL/m^2、(38.83±9.28)mL/m^2和(47.88±8.29)%;血清sLOX-1、CK-MB与LVEDVI、LVESVI和LVEF未见明显相关性(P>0.05);AMI组重度狭窄患者血清sLOX-1、CK-MB明显高于轻度和中度狭窄患者(P<0.05);中度狭窄患者血清sLOX-1、CK-MB明显高于轻度狭窄患者(P<0.05);血清sLOX-1、CK-MB与Gensini评分呈正相关(G=0.339和0.252,P<0.05),血清sLOX-1与CK-MB呈正相关(r=0.301,P<0.05)。结论急性心肌梗死患者血清SLOX-1、CK-MB水平升高,与冠状动脉狭窄程度有一定相关性。  相似文献   
15.
目的:通过对不同宿主华支睾吸虫的同工酶研究,了解其在不同宿主中的变化情况.方法:应用浓度梯度聚丙烯酰胺凝胶板状电泳(CG-PAGE)对50 d虫体的乳酸脱氢酶(LDH)、苹果酸脱氢酶(MDH)、酯酶(EST)、过氧化物酶(PO)进行电泳观察,通过凝胶成像软件对酶(蛋白)带的迁移率、相对浓度分布、光密度等结果进行分析.结果:来自不同宿主(大鼠、犬、豚鼠、兔、猫)的虫体主要酶带特征基本相同,但次要酶带存在一定差异.结论:不同宿主的华支睾吸虫同工酶存在着一定的变化,实验结果为华支睾吸虫在不同宿主中的发育、生理、生化提供实验资料.  相似文献   
16.
An isoelectric focusing technique for the separation of alkaline phosphatase isoenzymes on cellulose acetate membrane is described. Optimal conditions for isoelectric focusing were established by changing ampholine concentration and focusing conditions. Bone, liver, intestinal, and placental isoenzymes can be resolved into vacious sub-bands in a pH range of 4.1 to 5.2. These sub-bands were correlated with the findings of electrophoretic isoenzyme separation. The whole procedure proves very simple to perform and comparatively time saving (4 h). This procedure may help clarify the problems of ALP isoenzyme differention when electrophoretic patterns are unresolved.  相似文献   
17.
目的 观察心肌肌钙蛋白I(cTnI)和CK -MB在冠状动脉旁路移植术 (CABG)围术期变化 ,以判断心肌损伤状况。方法  19例CABG病人 ,其中 3例同时行左室室壁瘤切除。平均体外循环时间12 1min ,阻断升主动脉 5 6min。灌注冷血停跳液保护心肌 ,平均每例搭桥 3 2支。围术期 2 0个时间点取静脉血标本 ,留血浆测cTnI和CK MB。术前及术后第 7d作标准 12导联心电图 (ECG)。结果 cTnI术前 5例升高者 ,停机后全部升高 ,第 8h达高峰 ,术后第 7d有 7例 (36 8% )仍高于正常 ;CK MB阻断升主动脉前正常 ,停机后升高 ,第 6h达高峰 ,术后第 2d全部恢复正常 ;2例发生围术期心梗 (PMI)者 ,整个围术期cTnI高于无PMI者 ;cTnI阻断升主动脉前已升高者 ,术后升高更显著。结论 cTnI与CK MB在CABG术后变化规律相似 ,但cTnI高于正常的持续时间长于CK MB ,有利于回顾性诊断 ;若阻断升主动脉前cTnI已升高 ,术后水平更高 ;cTnI诊断心肌损伤敏感性高于CK -MB。  相似文献   
18.
Lycopene is widely used as a dietary supplement. However, the effects of lycopene on cytochrome P450 (CYP) enzymes or P-glycoprotein (P-gp) are not comprehensive. The present study was performed to investigate the effects of lycopene on the CYP enzymes and P-gp activity. A cocktail method was used to evaluate the activities of CYP3A4, CYP2C9, CYP2C19, CYP2D6 and CYP2E1. Caco-2 cell monolayer model was carried out to assay lycopene on P-gp activity. The results indicated that lycopene had a moderate inhibitory effect on CYP2E1, with IC50 value of 43.65?μM, whereas no inhibitory effects on CYP3A4, CYP2C19, CYP2D6 and CYP2E1, with IC50 values all over 100?μM. In addition, lycopene showed almost no inhibitory effect on rhodamine-123 efflux and uptake (p?>?.05), indicated no effects on P-gp activity. In conclusion, there should be required attention when lycopene are coadministered with other drugs that are metabolised by CYP2E1.  相似文献   
19.
Summary A new method for the separation of isoenzymes of-glutamyl-transpeptidase is described, using electrophoresis on acetate cellulose gel and a developing solution composed by-glutamyl-naphthylamide, and a colored diazonium compound.The method permits the separation of up to four different isoenzymes, which we called-GT1,-GT2,-GT3,-GT4, the first two showing an electrophoretic migration similar to that of 1- and 2-globulins and the other two to that of-globulins.The present technique has proved its usefulness in detecting isoenzymes in serum with values of total-glutamyl-transpeptidase higher than 80 U/L.The application of this method in 52 patients with different types of biliary obstruction and hepatocellular damage has shown that it provides new possibilities in differential diagnosis.  相似文献   
20.
Summary Alterations of myocardial mechanical catecholamine responsiveness by swimming training (2×90 min/day, 4 weeks) were examined in 13-week-old spontaneously hypertensive male rats (SHR). The relationships between myocardial mechanical catecholamine responsiveness and ventricular -adrenoceptors as well as myosin isoenzyme pattern were also examined. Compared with sedentary controls, trained rats showed a greater responsiveness to isoproterenol (10–6 mol/l) on isometric tension (T) and its first derivative (dT/dt) (T:0.45±0.55 vs. –0.15±0.11 10–2 N/mm2, p<0.01, dT/dt: 17.1±10.1 vs. 8.3±3.6 10–2 N/mm2·s, p<0.05). In sedentary SHR, dT/dtmax increased significantly, whereas developed tension decreased slightly, coupled with a decrease of time to peak tension by high dose (10–6 mol/l) isoproterenol. Therefore, it can be stated that dT/dt is a better indicator for catecholamine sensitivity than isometric tension. -adrenoceptor density ([3H]-dihydroalprenolol binding) decreased significantly in trained rats (68.7±7.62 vs. 102.4±4.37 fmol/mg protein, p<0.01) with no significant difference in KD values (4.61±2.26 vs. 6.11±1.94 nM, ns). In addition, myosin isoenzyme pattern revealed by pyrophosphate gel electrophoresis shifted towards VM-1 after swimming training. The increased catecholamine sensitivity of fast contracting myocardium is, in principle, compatible with the assumption of cAMP-dependent regulation of myofibrillar ATPase activity (21) or cross bridge kinetics (9), although other postreceptor processes should also be taken into consideration for the increased catecholamine sensitivity.Supported by the Deutsche Forschungsgemeinschaft  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