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   88268篇
  免费   8076篇
  国内免费   6536篇
耳鼻咽喉   712篇
儿科学   922篇
妇产科学   1057篇
基础医学   10789篇
口腔科学   1655篇
临床医学   12049篇
内科学   13250篇
皮肤病学   836篇
神经病学   4804篇
特种医学   3215篇
外国民族医学   61篇
外科学   8606篇
综合类   15100篇
现状与发展   30篇
一般理论   3篇
预防医学   5244篇
眼科学   2568篇
药学   9108篇
  68篇
中国医学   4906篇
肿瘤学   7897篇
  2024年   469篇
  2023年   1686篇
  2022年   3862篇
  2021年   4687篇
  2020年   3568篇
  2019年   3082篇
  2018年   3144篇
  2017年   2919篇
  2016年   2635篇
  2015年   4137篇
  2014年   4927篇
  2013年   4191篇
  2012年   6321篇
  2011年   7128篇
  2010年   4270篇
  2009年   3256篇
  2008年   4189篇
  2007年   4483篇
  2006年   4417篇
  2005年   4544篇
  2004年   2787篇
  2003年   2548篇
  2002年   2223篇
  2001年   1906篇
  2000年   2143篇
  1999年   2499篇
  1998年   1663篇
  1997年   1582篇
  1996年   1211篇
  1995年   1059篇
  1994年   885篇
  1993年   604篇
  1992年   714篇
  1991年   611篇
  1990年   554篇
  1989年   475篇
  1988年   396篇
  1987年   350篇
  1986年   247篇
  1985年   192篇
  1984年   93篇
  1983年   77篇
  1982年   41篇
  1981年   45篇
  1980年   29篇
  1979年   30篇
  1965年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Zusammenfassung Eine neu aufgetretene Dyspnoesymptomatik und eine symmetrische, apikal betonte retikulonodul?re Zeichnungsvermehrung im R?ntgen-Thorax bei jungen rauchenden Erwachsenen müssen an das seltene Krankheitsbild der pulmonalen Histiocytosis X denken lassen. Klinischer Befund, laborchemische- und Lungenfunktionsuntersuchungen zeigen unspezifische Befunde. Neue radiologische Verfahren wie die hochaufl?sende Computertomographie (HRCT) leisten bei gezielter Indikationsstellung eine entscheidende differentialdiagnostische Hilfestellung. Dieser Fall verdeutlicht die M?glichkeit einer Diagnosesicherung durch transbronchiale Biopsien unter Verzicht auf offene Lungenbiopsien. Eine ambulante Diagnostik war m?glich, das h?here Risiko eines operativen Eingriffes konnte vermieden werden. Die Indikation zur Therapie ist nicht gesichert und wird daher durch den Grad der subjektiven bzw. funktionellen Einschr?nkung sowie den Verlauf bestimmt.  相似文献   
12.
Twenty five cases, including 26 eyes with retinal vein occlusion (RVO) were examined by means of the electro-oculogram. The results showed that 23 of the 26 eyes suffering from RVO exhibited abnormalities of the electro-oculogram (EOG). The potential difference and Arden ratio in the RVO eyes were lower than those in the normal eyes (P<0.01). The more the visual acuity of ill eyes was decreased, the higher the abnormal rate of EOG in ill eyes was. 14 eyes had the visual acuity less than 0.1, whose EOGs were abnortmal. Six eyes had the visual acuity from 0. 2 to 0. 4, in which the EOGs of 5 eyes were abnormal. Six eyes had the visual acuity more than 0. 5, a-mong which the EOGs of 4 eyes were abnormal. Based on the above observations, it may be considered that the circulatory disturbance resulting from RVO damages not only the internal layer but also the external layer of the retina. We suggest that EOG is a useful method for distingquishing lesions caused by RVO and may reflect the functional condition  相似文献   
13.
分别采用联合火箭免疫电泳技术和酶法对49例冠心病患者和50例健康人血清载脂蛋白 A_1(apoA_1),载脂蛋白 B_(100)(apoB_(100)),以及血清总胆固醇(TC)、甘油三酯(TG),高密度脂蛋白胆固醇(HDL—ch)的含量进行了测定。结果冠心病患者血清 apoB_(100)(0.99±0.26g/L)明显高于健康人(0.62±0.18g/L);而apoA_1/apoB_(100)比值(1.22±0.35)则明显低于健康人(2.12±0.49);TC,TG,HDL-ch 的含量亦有统计学意义。提示,在预示冠心病危险因素的各种脂类及脂蛋白中,以 apoB_(100)增高 apoA_1/apoB_(100)比值降低最为灵敏,最为准确,且高于单纯测定TC,TG 和 HDL-ch。  相似文献   
14.
Four cases of microtia association with hemifacial aplasia were repaired by one-stage reconstruction. The operations included external ear reconstruction and correction of facial deformity with free vascularized dermis fat flaps. All were successful, the results were satisfied. The method and the device of the operation are described in detail. The advantages of the technique are discussed.  相似文献   
15.
周桂平 《护理研究》2007,21(32):2939-2939
皮肤慢性溃疡是较难治愈的疾病,自2003年采用橡皮生肌膏外用配合氦氖激光照射治疗皮肤溃疡取得良好疗效。现报告如下。1病例介绍[例1]病人,男,45岁。5年前因外伤致足跟部皮肤破损并感染,经各种治疗无效,伤口长年不愈,于2005年3月12日来我院就诊。查体:全身情况尚好,左足跟可见3  相似文献   
16.
OBJECTIVE: To evaluate the effect of hyperfractionated radiation therapy and concomitant chemotherapy for inoperable stage III non-small cell lung cancer (NSCLC). METHODS: Seventy patients were randomized equally into two group. The therapy group received radiotherapy with hyperfractionated radiation therapy combined with concomitant chemotherapy, and the control group was treated with chemotherapy only. RESULT: The overall response rate, including the rate of both complete (CR) and partial responses (PR), in the therapy group was 60.0% with a CR rate of 8.6%. The overall response rate in the control group was 40.0% with a CR rate of 5.7%. The difference in overall response rate was statistically significant between the two groups (P<0.05). The median survival time, 1- and 2-years survival rate were 12.8 months, 48.6%, and 25.7%, respectively, in the hyperfractionated radiotherapy group, and 9.4 months, 34.3%, and 17.1%, respectively, in the chemotherapeutic group (P 0.031). The major toxic effects of the chemotherapy were myelosuppression and radiation esophagitis. CONCLUSION: Hyperfractionated radiation therapy plus concomitant chemotherapy with paclitaxel for inoperable stage III NSCLC improves the short-term response of the patients, but fail to raise the survival rate.  相似文献   
17.
Background: Volatile anesthetic preconditioning (APC) protects against myocardial ischemia-reperfusion (IR) injury, but the precise mechanisms underlying this phenomenon remain undefined. To investigate the molecular mechanism of APC in myocardial protection, the activation of nuclear factor (NF) [kappa]B and its regulated inflammatory mediators expression were examined in the current study.

Methods: Hearts from male rats were isolated, Langendorff perfused, and randomly assigned to one of three groups: (1) the control group: hearts were continuously perfused for 130 min; (2) the IR group: 30 min of equilibration, 15 min of baseline, 25 min of ischemia, 60 min of reperfusion; and (3) the APC + IR group: 30 min of equilibration, 10 min of sevoflurane exposure and a 5-min washout, 25 min of global ischemia, 60 min of reperfusion. Tissue samples were acquired at the end of reperfusion. NF-[kappa]B activity was determined by electrophoretic mobility shift assay. The NF-[kappa]B inhibitor, I[kappa]B-[alpha], was determined by Western blot analysis. Myocardial inflammatory mediators, including tumor necrosis factor [alpha], interleukin 1, intercellular adhesion molecule 1, and inducible nitric oxide synthase, were also assessed by Western blot analysis.

Results: Nuclear factor [kappa]B-DNA binding activity was significantly increased at the end of reperfusion in rat myocardium, and cytosolic I[kappa]B-[alpha] was decreased. Supershift assay revealed the involvement of NF-[kappa]B p65 and p50 subunits. APC with sevoflurane attenuated NF-[kappa]B activation and reduced the expression of tumor necrosis factor [alpha], interleukin 1, intercellular adhesion molecule 1, and inducible nitric oxide synthase. APC also reduced infarct size and creatine kinase release and improved myocardial left ventricular developed pressure during IR.  相似文献   

18.
邹柳红  周淑梅 《护理研究》2007,21(13):1218-1219
不动杆菌为条件致病菌,致病力不强,一般情况下很少引起感染,但当机体抵抗力降低或正常免疫屏障被破坏时可引发疾病,确切的致病因子目前尚无定论[1].我院于2005年8月24日收治1例因乙酸钙不动杆菌所致角膜溃疡病人,经过及时、有效的治疗及精心护理,取得了较好的疗效,现将其护理总结如下.  相似文献   
19.
豚鼠内耳磁微粒栓塞缺血模型初探   总被引:3,自引:0,他引:3  
OBJECTIVE: To set up an inner ear ischemic model in guinea pig with ferromagnetic embolism. METHODS: A magnet was fitted in the external auditory canal and carbonyl iron filings (1%, 1 ml/kg) was injected into jugular, then the inner ear vessels were obstructed by ferromagnetic spheres. Cochlear blood flow (CBF) and number of red blood cells in the stria vessels were used to detect the model's ischemia of cochleae. The slice of temple bone and basal membrane stained by silver nitrate were used for inner ear's histopathological observations. RESULTS: The iron spheres were amassed in the one and two-day-later's model of inner ear vessels, which resulted in embolism. The number of red blood cells in the stria vessels decreased and then recovered to normal level after 4 days, but the CBF decreased to 50% +/- 10% of basic level immediately and recovered to 99% +/- 41% 4 days later. Scattered lesion of out hair cell cilium could be seen in cochleae in eight-day-later's model, and degenerations in different degree were found in vascular stria. CONCLUSION: The methods of inner ear ischemic model with ferromagnetic embolism could be practical and the decrease of CBF was reversible, so it may be an ideal model for studying some ischemic inner ear diseases and evaluating the effects of therapeutic drugs.  相似文献   
20.
The measurement of amniotic fluid (AF) acetylcholinesterase isoenzyme (AChEI) is a relatively new method for early diagnosis of open neural tube defects (NTDs). As quantitative methods are of unproven reliability at present, the authors used a high resolving power qualitative method-vertical slab polyaerylamide gel electrophoresis. The benefits of this technique are: simplicity of operation, accuracy, unsophisticated equipment, and easily available reagents. Combined results of 9 NTDs studies revealed that samples from early pregnancy gave more accurate results than those from late pregnancy.  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