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   44350篇
  免费   3802篇
  国内免费   3041篇
耳鼻咽喉   354篇
儿科学   670篇
妇产科学   626篇
基础医学   5502篇
口腔科学   704篇
临床医学   5867篇
内科学   7278篇
皮肤病学   461篇
神经病学   2770篇
特种医学   1379篇
外国民族医学   17篇
外科学   4876篇
综合类   6767篇
现状与发展   5篇
一般理论   7篇
预防医学   2673篇
眼科学   1210篇
药学   4416篇
  31篇
中国医学   1855篇
肿瘤学   3725篇
  2024年   140篇
  2023年   668篇
  2022年   1713篇
  2021年   2180篇
  2020年   1595篇
  2019年   1532篇
  2018年   1596篇
  2017年   1373篇
  2016年   1280篇
  2015年   1912篇
  2014年   2382篇
  2013年   2152篇
  2012年   3219篇
  2011年   3444篇
  2010年   2054篇
  2009年   1682篇
  2008年   2329篇
  2007年   2361篇
  2006年   2226篇
  2005年   2238篇
  2004年   1521篇
  2003年   1473篇
  2002年   1247篇
  2001年   1104篇
  2000年   1123篇
  1999年   1227篇
  1998年   654篇
  1997年   713篇
  1996年   528篇
  1995年   478篇
  1994年   411篇
  1993年   296篇
  1992年   365篇
  1991年   319篇
  1990年   270篇
  1989年   238篇
  1988年   219篇
  1987年   188篇
  1986年   168篇
  1985年   123篇
  1984年   69篇
  1983年   78篇
  1982年   47篇
  1981年   53篇
  1980年   29篇
  1979年   44篇
  1978年   20篇
  1977年   17篇
  1974年   18篇
  1973年   16篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
唐省三  马亚珍 《陕西医学杂志》2005,34(8):918-920,963
目的:研究灯盏花素(Bre)对大鼠脑缺血-再灌注引起脑损伤的保护作用。方法:实验选用40只雄性Wistar大鼠,大鼠被随机分成5组:假手术组、对照组、硫酸镁(Mg-SO4)治疗组、灯盏花素治疗和组。自大鼠颈总动脉插入尼龙线栓栓塞大脑中动脉,造成大脑缺血,拔出线栓实现再灌注。脑缺血10min后给予75mg/kg和50mg/kgBre及30mg/kgMgSO4,分别于脑缺血1h,再灌注2h,5h和23h分别进行神经病学评分,并于脑缺血1h,再灌注23h时测定脑梗死面积,用TUNEL法和免疫组化法分别检测脑组织凋亡细胞和Caspase-3阳性细胞的变化。结果:灯盏花素降低脑缺血-再灌注大鼠神经病学评分,缩小脑梗死面积,降低脑组织凋亡细胞和Caspase-3阳性细胞数量,其作用强于硫酸镁。结论:灯盏花素通过抑制细胞凋亡可显著保护大脑缺血-再灌注引起的脑损伤,其作用优于单用硫酸镁。  相似文献   
32.
Summary We prospectively examined bone growth patterns in 894 children aged 6–17 years at the baseline visit, with a 6-year follow-up. Results show bone “tracking” over a six-year interval and sexual dimorphism of bone attained levels and timing of peak bone growth. Our findings underscore childhood and adolescence as critical periods for building bone and developing gender differences. Introduction Bone growth patterns were prospectively examined in 894 Chinese children (496 males), aged 6–17 yrs, from a population-based twin cohort. Whole-body bone area (BA), bone mineral content (BMC), and bone mineral density (BMD) were measured by DEXA at baseline and a 6-yr follow-up. Methods Graphic smoothing plots and generalized estimating equations were used to model bone attained levels, growth, and “tracking”. Results Attained levels of BMC and BA increased curvilinearly with age. Male attained levels were higher than females after age ∼15 yr, but BMD was lower between 13–17 yrs (Tanner stage I to IV). In both genders, peak BMC and BMD growth lagged ∼2 yrs behind peak BA growth, which lagged 2 yrs behind peak height growth. Peak bone growth occurred 1–3 yrs later in males. Over the 6-yr follow-up, all bone measurements “tracked”, but “shifting” across ranks also occurred, and baseline tertile ranking influenced bone growth. Females with early menarche had higher attained levels than females with late menarche at age 12–13 yrs. Conclusion Our findings confirm and expand previous studies on peak bone growth conducted in Caucasian cohorts, particularly sexually dimorphic and maturational effects. The significant “tracking” of bone measurements in this 6-yr follow-up study underscores the importance that osteoporosis prevention should begin in childhood and adolescence. Fengxiu Ouyang and Binyan Wang contributed equally to this article. Source(s) of support: This study is supported in part by grant R01 HD049059, R01 HL0864619 and R01 AR045651 from the National Institute of Health and by the Food Allergy Project.  相似文献   
33.
34.
Chronic, recurrent, multifocal osteomyelitis (CRMO) is an obscure disease of bone, occurring in children. It appears to be an inflammatory condition with no obvious microbiological cause. Current treatments of antibiotics and anti-inflammatory medication appear to have limited success. This case report looks at two separate cases of CRMO where partial resection of the affected bone—the clavicle—leads to complete resolution of symptoms and regrowth of the excised bone.  相似文献   
35.
没有监督的权力会导致腐败,这是一个显而易见的道理。尽管每一组织、机构、行业乃至个人都必须建立和遵从各自的行业道德和职业操守,但保证每个社会单元都能进退有序,除了建章立制的条令约束,更需要来自第三方的行之有效的监管。事关民生疾苦的医疗卫生无疑首当其冲。  相似文献   
36.
早期糖尿病视网膜病变的视网膜电图分析   总被引:1,自引:0,他引:1  
目的 分析早期糖尿病视网膜病变(DR)的闪光视网膜电图(F—ERG)和视网膜电图震荡电位(OPs)各参数的变化特点,寻找反映早期DR的敏感指标。方法 对16例(32只眼)正常人进行OPs和F-ERG检测。对27例(53只眼)糖尿病病人进行眼底荧光血管造影(FFA)、OPs和F—ERG检测。结果 OPs中Os波幅、O4波幅、OPs总波幅及F-ERG中b波峰潜时较其他指标敏感,其中O4波幅和b波峰潜时为最敏感指标,但均不能反映早期DR的严重程度。结论 OPs的O4波幅和F—ERG的b波峰潜时可作为早期糖尿病视网膜病变诊断的敏感指标。  相似文献   
37.
OBJECTIVES: Local anaesthetic infiltration into the carotid sinus during carotid endarterectomy (CEA) has been recommended to minimise blood pressure fluctuations but its use remains controversial. The aim of this meta-analysis was to determine whether intra-operative administration of local anaesthetic reduces the incidence of haemodynamic instability following CEA. MATERIALS AND METHODS: A search of the Medline, Pubmed and Embase databases and the Current Controlled Trials register identified four trials, which met the pre-defined inclusion criteria for data extraction. Pooled odds ratios with 95 per cent confidence intervals (c.i.) for the development of post-operative hypotension and hypertension were calculated using a random-effects model. RESULTS: Outcomes of 432 patients were studied. Local anaesthetic blockade of the carotid sinus was associated with a pooled odds ratio of 1.25 (95 per cent c.i. 0.496 to 3.15); p=0.216) and 1.28 (95 per cent c.i. 0.699 to 2.33; p=0.428) for the development of post-operative hypotension and hypertension respectively. Although none reach significance there was a trend towards increased risk of developing a complication in those patients who received local anaesthetic. CONCLUSIONS: There are insufficient data to determine the role of intra-operative local anaesthetic administration in reducing post-operative blood pressure lability following CEA. Conversely, the possibility of harm cannot be excluded on the basis of the currently available data.  相似文献   
38.
应用前列腺素E1注射治疗勃起功能障碍8年经验   总被引:1,自引:0,他引:1  
目的观察前列腺素E1(PGE1)注射治疗勃起功能障碍(ED)的长期疗效、副作用及预后。方法使用PGE1行阴茎海绵体注射,阴茎硬度检查仪(Rigiscan)连续记录1h,并根据观察结果,调查PGE1注射剂量,确定每例患者合适的注射量,掌握注射方法后回家自行注射。共筛选出ED患者410例,随访患者阴茎勃起情况、药量调整和副作用。结果410例ED患者中,心理性139例,静脉性83例,动脉性36例,神经性78例,混合性74例。对治疗满意的患者有256例(62.44%),其中21例(5.1%)在使用PGE15次后停用,并能达到满意的性生活而治愈。293例(71.46%)患者自述注射时有胀痛感。171例(43.17%)因疼痛(105例)、操作不便(25例)、副作用顾虑(37例)和其他原因(4例)而于6个月后放弃治疗。204例(49.76%)患者使用时间已超过1年,24例(5.85%)患者使用时间已超过5年,7例(1.7%)使用已有8年。未发现阴茎异常勃起和阴茎海绵体纤维化。注射损伤阴茎表面血管致瘀斑者有20例。有27例患者失访。结论PGE1是治疗ED的一种安全有效的药物,可以长期使用。其最常见的副作用是阴茎疼痛。Rigiscan能帮助确定PGE1的注射剂量。  相似文献   
39.
Purpose Post operative monitoring is crucial for the success of microsurgical free tissue transfer. Sophisticated and expensive methods are available for monitoring. We propose a novel technique using digital photography and the internet as a reliable and cost effective method to monitor free tissue transfers. Methods 163 micro‐vascular procedures were monitored using this technique over 8 months. Serial photographs taken to show flap color. Capillary refill time, pin prick‐ bleed time and color and hand held Doppler signal was recorded in the movie mode of a standard 5 mega pixel camera with duration of 15 seconds. Data was sent to the surgeon at regular intervals and or as deemed necessary. Results Analysis of the 67 cases is presented. 5 re‐explorations were done. The early diagnosis of venous congestion was possible using this technique. Timely intervention contributed to the success of the re‐explorations and these flaps could be salvaged. The file size of images was in the range of 1 MB–6 MB. The file size of an entire set of images ranged about 7 MB–9 MB. These were sent across the ADSL internet lines. Conclusion The use of the digital images and the internet allow reconstructive surgeons to have a reliable picture of the state of their free tissue transfers. This permits decrease in observer error and saves valuable time which otherwise needs to be spent to verify situations of doubt and offers an ideal solution to the logistic problem of having to visit the patient in case of doubt.  相似文献   
40.
目的 探讨实时双平面超声心动图的临床应用价值。方法 对 83例受检者进行实时双平面超声 (BP)检查 ,其中男 46例 ,女 3 7例 ,平均年龄 2 0 92± 19 16岁。正常人 10例 ,先天性心脏病 44例 ,心瓣膜病 2 6例 ,其他心脏病变3例。结果 实时双平面超声有助于理解心脏立体解剖 ;能通过有限的声窗获得更多的切面 ,并可显示常规经胸超声不易得到的切面 ;多切面显示心脏瓣膜及其病变 ,有利于获得瓣膜狭窄或关闭不全的最佳观察平面 ;多切面显示房、室间隔缺损 ,便于寻找缺损的最佳显示切面以及与毗邻结构的关系。房、室间隔缺损BP、2DE测值与手术测值均有良好相关性 ;室间隔缺损BP测值与手术测值无显著性差异 ;BP、2DE均有低估房间隔缺损大小的倾向。实时双平面超声能同时显示复杂先心病的多种解剖畸形 ,有利于确定房室连接 ;辨认主、肺动脉。结论 实时双平面超声有其独特的优势 ,可为心血管疾病的准确诊断提供更多的信息。  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