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   1125篇
  免费   5篇
  国内免费   5篇
耳鼻咽喉   10篇
儿科学   33篇
妇产科学   9篇
基础医学   270篇
口腔科学   4篇
临床医学   25篇
内科学   163篇
皮肤病学   13篇
神经病学   101篇
特种医学   40篇
外科学   74篇
综合类   20篇
预防医学   22篇
眼科学   10篇
药学   279篇
中国医学   9篇
肿瘤学   53篇
  2023年   11篇
  2022年   26篇
  2020年   6篇
  2019年   9篇
  2018年   7篇
  2014年   8篇
  2013年   19篇
  2012年   8篇
  2011年   9篇
  2010年   8篇
  2009年   8篇
  2008年   4篇
  2007年   8篇
  2006年   18篇
  2005年   53篇
  2004年   73篇
  2003年   52篇
  2002年   8篇
  2001年   24篇
  2000年   24篇
  1999年   26篇
  1998年   15篇
  1997年   19篇
  1996年   29篇
  1995年   46篇
  1994年   51篇
  1993年   51篇
  1992年   37篇
  1991年   36篇
  1990年   23篇
  1989年   31篇
  1988年   26篇
  1987年   27篇
  1986年   19篇
  1985年   22篇
  1984年   30篇
  1983年   7篇
  1982年   21篇
  1981年   23篇
  1980年   22篇
  1979年   26篇
  1978年   21篇
  1977年   24篇
  1976年   27篇
  1975年   16篇
  1974年   13篇
  1973年   20篇
  1972年   11篇
  1971年   13篇
  1969年   4篇
排序方式: 共有1135条查询结果,搜索用时 15 毫秒
1.
目的探讨高能聚焦超声刀加氟脲嘧啶、四氢叶酸治疗晚期胰腺癌临床疗效及毒副作用。方法30例经病理学或细胞学确诊的晚期胰腺癌病人先用高能聚焦超声刀(HIFU)治疗,再予氟脲嘧啶、四氢叶酸联合化疗。氟脲嘧啶500mg/m^2加入5%GNS500ml静滴持续6小时以每天1次连用5天,CF(四氢叶酸)100mg/m^2加入生理盐水250ml静滴每天1次连用5天,28天为1周期,至少治疗2个周期。结果CR1例;PR9例;MR9例;NC5例;PD6例。总有效率63%。毒副作用主要消化道反应,其他副作用轻微。结论应用HIFU局部治疗胰腺癌同时合用四氢叶酸加氟脲嘧啶全身化疗近期疗效提高明显,止痛明显达75%,副反应小,值得应用。  相似文献   
2.
从语法角度归纳了医学科技论文中冠词的使用规律,以期减少英语医学科技论文中冠词的衍缺现象。  相似文献   
3.
人前列腺癌细胞PC-3M亚系u-PAR基因与蛋白质表达   总被引:4,自引:0,他引:4  
为研究与人前列腺癌细胞(PC-3M)侵袭能力相关的靶分子,采用有限稀释法分离单克隆细胞株,并应用单层细胞侵袭等实验鉴定各亚系的体外侵袭能力;借助RT-PCR和免疫组化的方法,分别在转录和翻译水平检测5株侵袭能力不同的PC-3M亚系尿激酶型纤溶酶原激活物受体(u-PAR)的表达。结果显示,高侵袭亚系-u-PAR基因mRNA的表达和蛋白质水平均明显高于低侵袭亚系,提示;PC-3M亚系u-PAR的高表达与其较强的侵袭能力密切相关,而u-PAR可能是抑制高侵袭亚系侵袭效应的一个重要靶分子。  相似文献   
4.
Summary The present study was designed to clarify whether or not a difference between arterial and venous lactate (u50422055h6rl568/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0">lactate) levels is useful for evaluation of mitochondrial function in ischemia-reperfused myocardium. In the first experiment, 12 dogs were divided into 2 groups: 10-min occlusion of the left anterior descending coronary artery (LAD) followed by 10-min reperfusion, or 30-min occlusion followed by 40-min reperfusion, were performed. The lactate levels in the femoral artery and the great cardiac vein were measured enzymatically. u50422055h6rl568/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0">Lactate was reversed immediately after occlusion. Ten min and 20 min were required for the recovery of u50422055h6rl568/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0">lactate in the 10-min-occlusion with 10-min-reperfusion, and 30-min-occlusion with 40-min-reperfusion groups, respectively. In the second experiment, 36 dogs were divided into 6 groups: 10-min occlusion of LAD; 10-min occlusion with 10-min reperfusion; 30-min occlusion; and 30-min occlusion with 10-, 20-, or 40-min reperfusion were performed. Mitochondria from normal and occluded or reperfused areas were prepared, and the respiratory function of the mitochondria was measured polarographically. No significant decreases in the mitochondrial function were observed in the 10-min-occlusion, and 10-min-occlusion with 10-min-reperfusion groups. On the other hand, respiratory function of mitochondria was impaired by 30-min occlusion and was not improved by 10- or 20-min reperfusion. Significant recovery in the mitochondrial function was observed after 40-min reperfusion. That is, differing recovery time courses between u50422055h6rl568/xxlarge916.gif" alt="Delta" align="BASELINE" BORDER="0">lactate and the mitochondrial function were observed.  相似文献   
5.
Summary The size of the neuronal and non-neuronal histamine pools in the brain of three different strains of rats was measured by assuming that the u57/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-fluoromethylhistidine-induced maximal decrement of histamine represents the size of the neuronal pool. Although the total histamine levels in the brain showed a considerable interstrain variation, no significant interstrain difference was observed in the neuronal histamine level. These results suggest that the size of the neuronal histamine pool in the brain is relatively stable, whereas the size of the non-neuronal histamine pool is variable.  相似文献   
6.
Summary Impairment of skeletal muscle function is the common feature of distinct clinical forms of glycogenosis type II. In the present study, muscle cultures from different patients were used to investigate the cause of clinical heterogeneity and the feasibility of enzyme replacement therapy. The activity of acid u0864817np01rk54/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-glucosidase appears to be the primary factor in determining the extent of lysosomal glycogen storage in muscle, and thereby the clinical severity of the disease. Neutral u0864817np01rk54/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-glucosidases do not seem influencial. Correction of the enzymatic defect was achieved in skeletal muscle cultures from patients by administration of a u0864817np01rk54/xxlarge8220.gif" alt="ldquo" align="MIDDLE" BORDER="0">high-uptakeu0864817np01rk54/xxlarge8221.gif" alt="rdquo" align="MIDDLE" BORDER="0"> form of acid u0864817np01rk54/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">-glucosidase, purified from human urine. The enzyme reaches the lysosomes, including the glycogen storage vacuoles, and the lysosomal glycogen content is reduced to control level. In normal muscle cells 20% of the total cellular glycogen pool is segregated in lysosomal compartments. This percentage is higher than in fibroblasts, which may partly explain why muscles are more prone to store glycogen. The relevance of this study for enzyme therapy is discussed.  相似文献   
7.
Five aliphatic 5u1m1u/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">-esters of 5-iodo-2u1m1u/xxlarge8242.gif" alt="prime" align="BASELINE" BORDER="0">deoxyuridine (IDU) were synthesized via an acid chloride alcoholysis reaction. The solubility in pH 7.4 phosphate buffer, lipophilicity as determined by partition experiments in octanol/pH 7.4 buffer, and cytotoxicity of these potential prodrugs were evaluated. The esters showed a 43- to 250-fold increase in lipophilicity and a 1.6- to 14-fold decrease in aqueous solubility relative to IDU. At a concentration of 50 µM, all esters showed reduced cytotoxicity toward uninfected Vero cells relative to IDU.  相似文献   
8.
In order to clarify the etiology of a dose-related increase in the incidence of tubular cell adenocarcinomas of the kidney in male rats, the nephrotoxicity of p-dichlorobenzene (p-DCB) was investigated in a subchronic study. Groups of ten male and ten female Fischer 344 rats were dosed by gavage with 0 (controls), 75, 150, 300 or 600 mg p-DCB/kg/day in corn oil. Half of the animals were sacrificed after 4 weeks and the remainder after 13 weeks. Increased urinary LDH and epithelial cell excretion and exacerbation of hyaline droplet accumulation in the cytoplasm of renal cortical cells were observed in male rats over the entire dose range investigated. Tubular single cell necrosis, dilated tubules with granular cast formation in the outer zone of the medulla, were evident in male rats after 4 and 13 weeks of treatment with doses of 150–600 mg/kg/day. In female rats there was no indication of a nephrotoxic action of p-DCB. The effects on the kidney, both in their morphological characteristics and the fact that they occur exclusively in male animals, correspond to the light hydrocarbon nephropathy observed as a result of short-term treatment with a number of aliphatic and cyclic hydrocarbons. The development of cortical renal tumors seems to be associated with this kind of kidney damage which is unique to male rats. The literature on this subject generally regards these renal effects as not predictive for man.  相似文献   
9.
10.
Summary We measured u82776564551531p/xxlarge945.gif" alt="agr" align="BASELINE" BORDER="0">ub>2ub>-plasmin inhibitor-plasmin complexes (PI-PC) in plasma of patients with systemic lupus erythematosus (SLE) to examine the plasminogen activation in SLE. The plasma PI-PC level in 23 patients with SLE was significantly higher than that in 18 normal subjects (P<0.001) and the SLE patients with nephrotic syndrome had higher plasma PI-PC levels than those without nephrotic syndrome (P<0.01). In addition, the plasma PI-PC level was significantly correlated with the level of plasma C3 breakdown products (iC3b/C3dg) in the patients with SLE (r=0.53, P<0.01). These results suggest that plasminogen is activated in plasma of patients with SLE and that the plasminogen activation may be associated with the activation of complement in SLE.  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