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   39865篇
  免费   3000篇
  国内免费   1715篇
耳鼻咽喉   361篇
儿科学   525篇
妇产科学   414篇
基础医学   6246篇
口腔科学   3125篇
临床医学   4722篇
内科学   5207篇
皮肤病学   764篇
神经病学   1793篇
特种医学   1887篇
外国民族医学   8篇
外科学   5611篇
综合类   5023篇
现状与发展   10篇
预防医学   1189篇
眼科学   627篇
药学   3414篇
  10篇
中国医学   1395篇
肿瘤学   2249篇
  2024年   111篇
  2023年   586篇
  2022年   984篇
  2021年   1300篇
  2020年   1321篇
  2019年   1283篇
  2018年   1312篇
  2017年   1254篇
  2016年   1308篇
  2015年   1403篇
  2014年   2431篇
  2013年   3470篇
  2012年   2095篇
  2011年   2437篇
  2010年   1898篇
  2009年   1933篇
  2008年   2020篇
  2007年   2050篇
  2006年   1832篇
  2005年   1679篇
  2004年   1480篇
  2003年   1298篇
  2002年   1000篇
  2001年   902篇
  2000年   682篇
  1999年   655篇
  1998年   539篇
  1997年   514篇
  1996年   457篇
  1995年   405篇
  1994年   375篇
  1993年   293篇
  1992年   299篇
  1991年   280篇
  1990年   236篇
  1989年   239篇
  1988年   228篇
  1987年   203篇
  1986年   171篇
  1985年   232篇
  1984年   177篇
  1983年   134篇
  1982年   169篇
  1981年   175篇
  1980年   159篇
  1979年   122篇
  1978年   89篇
  1977年   83篇
  1976年   96篇
  1975年   37篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
21.
朱国献  徐梁 《中国美容医学》2007,16(11):1511-1512
目的:探求上唇外侧组织瓣在修复较大面积下唇缺损中的作用。方法:根据患者下唇缺损情况,设计上唇外侧组织瓣,旋转后插入缺损组织,同时在缺损吻合处,将上层外侧旋转瓣内侧粘膜肌肉向外牵拉形成部分新的红唇,然后逐层相对缝合,修复缺损。结果:自2003年1月应用此方法修复患者6例,术后随访1~2年,唇部外形好,无流涎,无口闭合不全,效果满意。  相似文献   
22.
BACKGROUND: Moderate hypothermia is one of the effective therapeutic methods for head injury in recent years, there are many mechanisms of moderate hypothermia for brain protection, and its influence on cerebral oxygenation is also one of them. OBJECTIVE: To observe the influence of moderate hypothermia on cerebral oxygenation of animals with acute intracranial hypertension, and further investigate the protective mechanism of moderate hypothermia. DESIGN: A randomized controlled trial. SETTING: Department of Neurosurgery, Renji Hospital affiliated to the Medical College of Shanghai Jiao Tong University. MATERIALS: Twenty healthy little pigs, either male or female, weighing 4.5–5.5 kg, were used. Neurotrend-typed multiparameter monitoring system (Diametrics Company, British); CMA/100 micro-injection pump (Carnegie Company, Sweden). METHODS: The experiment was conducted in the Changzheng Hospital affiliated to the Second Military Medical University of Chinese PLA in November, 2001. The pigs were randomized into two groups: the normothermia group (control group, n =10) and moderate hypothermia group (n =10). ① Bilateral femoral arteries were separated, one was connected to pressometer for monitoring mean arterial pressure (MEP), and the other for analysis of blood gases [including peripheral blood pH value, arterial partial pressure of carbon dioxide (PaCO2), arterial partial pressure of carbon dioxide (PaCO2), HCO3–]. ② Rectal temperature was monitored with mercurial thermometer. ③ Intracranial pressure was monitored using Camino optic ICP probe placed in the subdural space. ④ Neurotrend multiparameter monitoring sensor was inserted into the white matter for about 4 cm to determine cerebral perfusion pressure (CPP, CPP=MAP(ICP), brain tissue partial oxygen pressure (PO2), partial pressure of carbon dioxide (PCO2), HCO3– and brain temperature. The rectal temperature of animals in the moderate hypothermia group was lowered to 34 ℃ using ice bags, and the body temperature was maintained at 33–35 ℃ for 2 hours. The changes of the parameters were observed continuously, and the pigs in the normothermia group were not treated with cooling. MAIN OUTCOME MEASURES: ① MAP, ICP, rectal temperature, CCP; Indexes of cerebral oxygenation detected with Neurotrend-typed multiparameter monitoring system; ② Results of blood gases analysis in the moderate hypothermia group. RESULTS: All the 20 pigs were involved in the analysis of results. ① MAP, ICP, rectal temperature, CCP and indexes of cerebral oxygenation: In the moderate hypothermia group, the ICP after cooling was obviously lower than that before cooling [(3.31±1.19), (5.33±0.95) kPa, P < 0.05], CCP was higher, brain tissue PCO2 [(12.03±1.73), (10.59±2.01) kPa, P < 0.05], and brain tissue pH value was higher [(7.03±1.63), (9.40±1.30) kPa, P < 0.05], whereas the brain temperature was decreased as compared with that before cooling [(34.9±0.3), (37.2±0.2) ℃, P < 0.05]. ② Results of blood gases analysis in the moderate hypothermia group: There were no significant differences in the parameters of peripheral arterial blood gases analysis before and after cooling in the moderate hypothermia group (P > 0.05) CONCLUSION: Moderate hypothermia will not impair the cerebral oxygenation, and it can reduce brain tissue CO2 and decrease brain tissue acidosis.  相似文献   
23.
封闭式负压引流治疗软组织感染   总被引:3,自引:0,他引:3  
目的探讨封闭式负压引流治疗软组织感染的疗效。方法应用封闭式负压引流治疗开放性骨折发生软组织感染18例。结果18例均获随访,时间6个月-1年6个月。软组织感染均愈合,骨折正常愈合12例,延迟愈合6例,无慢性骨感染发生。结论封闭式负压引流治疗软组织感染,可短期控制感染,为进一步治疗创造条件,尤其适用于深部软组织感染患者。手术简单,疗效可靠,适合基层医院应用。  相似文献   
24.
Conjugated linoleic acid (CLA) is a unique lipid that elicits dramatic reductions in adiposity in several animal models when included at < or = 1% of the diet. Despite a flurry of investigations, the precise mechanisms by which conjugated linoleic acid elicits its dramatic effects in adipose tissue and liver are still largely unknown. In vivo and in vitro analyses of physiological modifications imparted by conjugated linoleic acid on protein and gene expression suggest that conjugated linoleic acid exerts its de-lipidating effects by modulating energy expenditure, apoptosis, fatty acid oxidation, lipolysis, stromal vascular cell differentiation and lipogenesis. The purpose of this review shall be to examine the recent advances and insights into conjugated linoleic acid's effects on obesity and lipid metabolism, specifically focused on changes in gene expression and physiology of liver and adipose tissue.  相似文献   
25.
瘦蛋白 (leptin)是由肥胖基因编码、脂肪细胞分泌的一种分子量为 16kDa的蛋白质 ,是一种重要的代谢调节信号 ,对人和动物的采食量、能量代谢、繁殖性能等具有重要调节功能 ,对人肥胖病的治疗和改善动物的生产性能、胴体组成等有良好的潜在应用前景 .主要概述了瘦蛋白基因的克隆、转录、表达调控以及瘦蛋白受体与信号转导等分子生物学特性  相似文献   
26.
Abstract Fifty moderate to severe hallux valgus deformities were corrected with a distal soft tissue realignment and proximal crescentic metatarsal osteotomy. With an average follow-up of 5.6 years, 40 feet (80%) were pain free and 42 (84%) caused no functional limitation. The average hallux valgus angle improved from 38.2° preoperatively to 12.4° at follow-up. The average intermetatarsal angle improved from 15.4° to 6.8°. The arch of motion of the first metatarsophalangeal joint was 75° preoperatively and 62° at follow-up. According to the AOFAS scoring system, 29 results (58%) were excellent, 14 (28%) good, 2 (4%) fair and 5 (10%) poor. The 5 poor results were attributed to recurrence of hallux valgus (2 cases), stiffness (1), hallux varus (1) and malunion of the osteotomy in dorsiflexion (1). The incidences of hallux varus and malunion in dorsiflexion were 8% and 14%, respectively. This technique is valuable in correction of moderate to severe hallux valgus deformities.  相似文献   
27.
The purpose of this study is to assess the sensitivity and specificity of magnetic resonance imaging (MRI) in the diagnosis of anterolateral impingement of the ankle and to assess the most helpful sequence in making the diagnosis. Twenty-four patients who had undergone ankle arthroscopy were chosen. Twelve patients had arthroscopically documented anterolateral impingement, and 12 patients with no impingement on arthroscopy served as controls. Two musculoskeletal radiologists and an orthopedic surgeon, blinded to the operative diagnosis, retrospectively reviewed selective MRI images in the sagittal, axial, and coronal planes. The sensitivities and specificities were calculated for all 3 reviewers. The Kendall coefficient of concordance was calculated for overall agreement among reviewers. Sensitivities varied from 0.75 to 0.83, whereas specificities varied from 0.75 to 1.00. Using the Fisher exact test of contingency, the sensitivities and specificities showed that all reviewers' interpretations were statistically significant with P = .039, .001, and .012, respectively. The axial images were felt to be most helpful in making the diagnosis. The physicians felt that the sagittal images were helpful in 67%, 83%, and 100%, respectively. MRI is a useful tool that can aid the clinician in the diagnosis of anterolateral impingement of the ankle. T1 sagittal images demonstrating displacement of the normal fat signal anterior to the fibula by scar can be useful and help to confirm the diagnosis.  相似文献   
28.
研究了聚环氧氯丙烷(PECHCH)/N(4-乙氧基苄叉)4-丁基苯胺(EBBA)复合膜对氧气和氮气的透过性和选择性。用示差扫描量热计(DSC)、解偏振光强仪(DLI和偏光显微镜考察了复合膜的形态结构。结果表明,当PECH/EBBA复合膜处于液晶的向列相转变温度时,有较高的气体透过性和选择性。发现只有复合膜中EBBA含量在30wt%以上,PECH和EBBA呈非均相混合时,才有较明显的富氧效果。当EBBA含量达50wt%时,氧氮分离系数α=3.78。  相似文献   
29.
田勇 《中国骨伤》2007,20(10):622-622
自1999年1月-2005年3月,应用胫前肌瓣修复胫骨骨髓炎合并软组织缺损13例,同时辅以中药治疗,获得较满意的效果,现报告如下。1临床资料本组13例,男9例,女4例;年龄1867岁,平均32岁。致伤原因:车祸伤6例,挤压伤4例,烧伤1例,坠落伤2例。胫骨上1/3段1例,中1/3段2例,下1/3段5例,中下2/3段5例。病程12d30个月,外露骨有干燥、硬化、发白、变黑,周围有肉芽、瘢痕组织、脓性分泌物等。外露骨纵形长0·68·0cm,皮肤缺损面积最大为4cm×10cm。2治疗方法2·1手术方法在硬膜外麻醉下,股部上止血带,术区常规消毒。首先切除溃疡及外露胫骨周围瘢痕,清除髓腔内分泌物及  相似文献   
30.
目的:基于累及头颈部淋巴组织病变的临床不典型性,旨在探讨MRI对其进行鉴别诊断的客观依据。方法:对本组22例可疑累及头颈部淋巴组织的各类病变进行MRI检查并与病理学结果进行对照。结果:MRI对本组22例累及淋巴组织病变的诊断与病理学诊断的符合率(21/22)约为95%。结论:MRI是对累及头颈部淋巴组织病变的重要检查手段,并能为明确其诊断提供客观依据。  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