首页 | 官方网站   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   25878篇
  免费   2351篇
  国内免费   2072篇
医药卫生   30301篇
  2024年   64篇
  2023年   368篇
  2022年   595篇
  2021年   1216篇
  2020年   960篇
  2019年   849篇
  2018年   885篇
  2017年   760篇
  2016年   799篇
  2015年   1145篇
  2014年   1418篇
  2013年   1274篇
  2012年   1778篇
  2011年   2045篇
  2010年   1298篇
  2009年   1027篇
  2008年   1364篇
  2007年   1422篇
  2006年   1339篇
  2005年   1375篇
  2004年   875篇
  2003年   974篇
  2002年   757篇
  2001年   638篇
  2000年   690篇
  1999年   796篇
  1998年   473篇
  1997年   479篇
  1996年   338篇
  1995年   315篇
  1994年   323篇
  1993年   178篇
  1992年   262篇
  1991年   225篇
  1990年   179篇
  1989年   178篇
  1988年   143篇
  1987年   115篇
  1986年   96篇
  1985年   99篇
  1984年   38篇
  1983年   20篇
  1982年   18篇
  1981年   16篇
  1980年   8篇
  1979年   31篇
  1977年   6篇
  1976年   5篇
  1971年   4篇
  1933年   4篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
121.
目的:了解流通领域中阿莫西林制剂的质量状况。方法:在全省各市县的部分医药经营企业,抽取阿莫西林胶囊及干糖浆共54批样品,按国家药品标准进行全检后,对其检验结果进行统计分析。结果:不合格的项目有含量、胶囊剂溶出度、干糖浆粒度。该药物制剂的标示百分含量普遍偏低。结论:影响该产品质量的主要项目是含量和溶出度,含量偏低的主要原因是厂家的低限投料,应予以充分重视。  相似文献   
122.
Sixty-seven cases of chronic hepatitis were treated with Radix Astragali. After treatment (2-month course), the clinical improvement rate in 38 cases of the Stagnation of the Liver-Qi and Deficiency of the Spleen type was 92.1%, and in 26 cases of the Deficiency of Liver Yin and Kidney Yin type was 88.5%, more effective than in the control group (P<0.05). The regulative effect to the levels of serum hormone was observed in the patients of the Stagnation of the Liver-Qi and Deficiency of the Spleen type treated with this medicine. The results showed that the levels of serum triiodothyronine, estradiol (female) and testosterone (male) were increased after treatment (1.40±1.38 ng/dl, 129.30±1.23 pg/ml and 496.24±1.47 ng/dl). Pre-treatment levels were 1.22±1.49 ng/dl, 104.60±1.45 pg/ml and 398. 17±1.55 ng/dl respectively (P<0.05); however, the level of serum prolactin (2.75±4.46 ng/ml) was lower after treatment than before treatment (3.20±3.82 ng/ml,P<0.05). No obvious changes were observed in the levels of serum follicle stimulating hormone, luteinizing hormone, thyroid stimulating hormone, thyroxine, triiodothyronine uptake ratio and cortisol after treatment.  相似文献   
123.
本文就宁夏医学院附属医院肿瘤外科1984~1994年6月收治的603例胃癌中的5例残胃癌患者,结合文献对其发病年龄,部位,发病率,生物学行为、临床表现、早期诊断以及残胃癌与胃大部切除术式的关系等进行了探讨,认为:1.以外科手术为主的综合治疗是残胃癌的治疗原则;2.定期随诊是早期发现残胃癌的关键,3.B-Ⅰ式吻合或Roux-en-Y式吻台取代B-Ⅱ式吻合,可避免十二指肠液返流入残胃,减缓残胃癌的发生。  相似文献   
124.
梁彩云 《医学信息》2007,20(4):309-310
目的探讨脾切除术后暴发性感染的临床的特点。方法对6例OPSI患者的原发疾病、临床特点及其病原学进行分析。结果4例原发疾病属于造血系统疾病,1例脾功能亢进,1例外伤性脾破裂;所有病例均起病急促而凶猛、病情迅速恶化,于短期内出现休克及DIC;所有病例血细菌培养均阳性,3例为G 球菌,2例为G-杆菌,1例为G-杆菌合并霉菌感染;经强有力地抗感染治疗5例痊愈,1例死亡。结论OPSI病情凶险,死亡率高,尤其是血液病患者OPSI发生率较高,医生在行脾脏切除时应慎重。  相似文献   
125.
Microtubules were purified by using two cycles of assembly and disassembly processes on fresh brain homogenates from 30 guinea pigs. The yield was about 60 mg. The effect of tetrandrine on tubulin was determined by spectrophotometric analysis and electron microscopy. In addition, we used the indirect immunofluorescent method including tubulin antibody to locate the presence of microtubules in 3T3 cells by fluorescence microscopy. The effects of colchicine and P204 were studied for comparison at the same time. The results showed that colchicine can effectively depolymerize microtubules, while tetrandrine showed aggregation, and in a different manner. The shape and structure of microtubules were definitely destroyed by colchicine, but were not affected by P204 which protected against the destructive effect of tetrandrine. This result indicated the safety of using a combination of P204 and tetrandrine in the treatment of silicosis.  相似文献   
126.
目的:观察糖基化终末产物(AGEs)对大鼠肾系膜细胞纤溶酶原激活物抑制物-1(PAI-1)表达的影响及其与细胞外基质(ECM)成分含量的关系。方法:体外培养正常大鼠肾系膜细胞,分别用糖化牛血清白蛋白(AGEs)及未经糖化的牛血清白蛋白(BSA)处理,以常规培养的肾系膜细胞作为对照,检测不同时间、不同浓度AGEs对纤维连接蛋白(FN)、Ⅳ型胶原、PAI-1表达的影响。MTT法检测AGEs对系膜细胞增殖的作用,ELISA测定条件培养基中FN、Ⅳ型胶原及PAI-1蛋白含量,逆转录聚合酶链式反应(RT—PCR)检测系膜细胞PAI-1 mRNA的表达。结果:与相应浓度的BSA比较,AGEs(0—200mg/L)对系膜细胞增殖无明显影响,但可不同程度地刺激系膜细胞FN、Ⅳ型胶原、PAI-1蛋白的产生。RT—PCR检测显示,给予AGEs(100mg/L)的系膜细胞PAI-1 mRNA的表达明显增加(P〈0.01)。结论:AGEs促进系膜细胞PAI—1的表达,提示AGEs通过上调PAI-1的表达而减少细胞外基质降解,可能是糖尿病肾病细胞外基质积聚的原因之一。  相似文献   
127.

Background  

Yunnan province is located in south western China and is one of the poorest provinces of the country. This study examines the premature mortality burden from common causes of deaths among an urban region, suburban region and rural region of Kunming, the capital of Yunnan.  相似文献   
128.
The interaction of irradiation, Misonidazole (MISO), and hyperthermia was studied in a C3H mouse mammary carcinoma and its surrounding skin in vivo. MISO (0.5-1.0 mg/g) was injected 30 min before irradiation. Hyperthermia (41.5 degrees-43.5 degrees C for 60 min) was given either simultaneously, 0.5 hr, or 4 hr after X rays. The results were evaluated as the radiation dose to achieve tumor control (TCD50) or moist desquamation of the skin (DD50) in half of the treated animals. A therapeutic gain was found when the enhancement in tumors were greater than that found in skin. The combination of simultaneous heat and irradiation caused great enhancement in radiation response, but with no therapeutic gain. A slightly lower enhancement of the damage in both tissues was found with a 30 min interval between irradiation and hyperthermia, whereas heat 4 hr after X rays gave a small, but significant therapeutic gain. MISO significantly enhanced the response in tumors but not in skin. Combined trimodality treatment with MISO, irradiation, and hyperthermia resulted in enhancement ratios up to 15, dependent on temperature, radiation-heat interval, and to a lesser extent the MISO dose. The enhancement was for all schedules most pronounced in the tumors, resulting in an improved therapeutic effect. The combination of MISO and hyperthermia may be a valuable addition to radiotherapy, especially if heat and irradiation can be applied with close interval and with one of the modalities given selectively to the tumor.  相似文献   
129.
Infection of CBA mice with Plasmodium berghei ANKA results in severe malaria, which is characterized by mortality 6 to 10 days after infection and is associated with alterations of the brain microcirculation. These alterations consist of (i) intravascular sequestration of monocytes, (ii) an increase in vascular permeability as documented by Evans blue diffusion, and (iii) microhemorrhages. This syndrome may be due to an increase of production of tumor necrosis factor alpha which upregulates the endothelial expression of ICAM-1 and thus leads to adhesion of CD11a/CD18 (LFA-1)-bearing cells. During severe malaria, we found an important sequestration of the CD11a-bearing polymorphonuclear neutrophil leukocytes (PMN) in the lung but not in the brain. Treatment with a monoclonal antibody (MAb) against PMN, which induces profound neutropenia, prevented mortality and Evans blue diffusion in the brain and the lung, while it unexpectedly increased the occurrence of microhemorrhages. The anti-PMN MAb abolished PMN sequestration in the lung and also partially decreased monocyte sequestration in the brain and the lung. Treatment with an anti-CD11a MAb also prevented mortality, Evans blue diffusion, and PMN and monocyte sequestration. This study shows that PMN contribute to the mortality and the microvascular lesions resulting from severe malaria. This may be due to their CD11a-dependent sequestration in the lung and also to their indirect influence on vascular permeability and the sequestration of monocytes.  相似文献   
130.
RolesofDNApolymeraseβonrepairofDNAdamagedbyγ-raysirradiationCaiJianming(蔡建明);ZhengXiulong(郑秀龙);LuoChengji(罗成基);GaoJianguo(高建国...  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-23

京公网安备 11010802026262号