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   22249篇
  免费   2881篇
  国内免费   455篇
耳鼻咽喉   131篇
儿科学   790篇
妇产科学   385篇
基础医学   1705篇
口腔科学   209篇
临床医学   2503篇
内科学   5601篇
皮肤病学   348篇
神经病学   1533篇
特种医学   369篇
外科学   2249篇
综合类   1746篇
现状与发展   1篇
一般理论   5篇
预防医学   5059篇
眼科学   773篇
药学   935篇
  3篇
中国医学   226篇
肿瘤学   1014篇
  2024年   39篇
  2023年   426篇
  2022年   201篇
  2021年   470篇
  2020年   444篇
  2019年   215篇
  2018年   779篇
  2017年   774篇
  2016年   833篇
  2015年   804篇
  2014年   743篇
  2013年   998篇
  2012年   1263篇
  2011年   2041篇
  2010年   1238篇
  2009年   1021篇
  2008年   1151篇
  2007年   1155篇
  2006年   965篇
  2005年   1089篇
  2004年   1884篇
  2003年   1677篇
  2002年   1208篇
  2001年   945篇
  2000年   504篇
  1999年   476篇
  1998年   412篇
  1997年   343篇
  1996年   162篇
  1995年   119篇
  1994年   112篇
  1993年   143篇
  1992年   125篇
  1991年   87篇
  1990年   87篇
  1989年   73篇
  1988年   63篇
  1987年   53篇
  1986年   46篇
  1985年   32篇
  1984年   24篇
  1983年   19篇
  1982年   20篇
  1981年   22篇
  1980年   14篇
  1977年   13篇
  1975年   13篇
  1974年   18篇
  1968年   17篇
  1928年   13篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
应用自体颅骨碎片及骨屑对60例在造成颅骨缺损术同时行颅骨缺损修补术。缺损面积直径最小者2cm,最大者10cm。术后随访1个月至5年,病人颅骨缺损修补处外观正常,无凹陷,触之硬,与正常颅骨处类似。6个月拍X线片示颅骨修补处类似正常颅骨形态。  相似文献   
102.
用化学发光法检测粒细胞吞噬功能具有灵敏、准确、快速等优点。用我校同位素实验室LS3801型液体闪烁分析仪,全部使用国产试剂,建立了分离的中性粒细胞化学发光测定法,并对影响因素作了初步观察和探讨。实验表明,此法既可用于中性粒细胞吞噬杀菌功能机理研究,亦可用于临床监测。对糖尿病人粒细胞功能化学发光测定结果,显示了此法应用的潜力。  相似文献   
103.
We investigated the natural history of atopic dermatitis (AD) in a population-based birth cohort and assessed whether children at risk of visible eczema at 5 years of age can be identified from total immunoglobulin E (IgE) levels measured at 8, 12 and 18 months. AD data collected included a whole body examination for visible eczema at 49 months (4 years) and 61 months (5 years) of age and parent completed questionnaire data throughout their early lives. Children were divided into four groups based on their natural history of early AD: persistent (AD at 1, 6, 18, 30 and 42 months, n  = 34), intermittent early onset (before 18  months of age, n  = 495), intermittent late onset (18–42 months of age, n  = 273) and unaffected ( n  = 429). Visible eczema at 5 years of age was present in 12.2% (117/957) (95% confidence interval [CI] 10.1–14.3%) of the children. Levels of total IgE at 8, 12 and 18 months of age were associated with early onset of AD, but not with AD of later onset. For all four natural history groups, the geometric mean total IgE at 12 months was higher in those who subsequently had visible eczema than those who did not. However, the degree of overlap was such that total IgE at 12 months of age was a poor predictor of eczema at age five. A cutoff point of 78 kU/l had the highest positive predictive value for visible eczema at 5 years of age of 28.6%, with a sensitivity of 12% and specificity of 95%.  相似文献   
104.
105.
第二足趾跖侧菱形皮瓣转移改形法再造拇指   总被引:5,自引:0,他引:5  
目的介绍第二足趾跖侧菱形皮瓣转移改形再造拇指的方法。方法用传统方法切取第二足趾后,于第二足趾近段跖侧设计菱形皮瓣,用180°逆形转移或向远侧直接推进的方法将皮瓣嵌入第二足趾跖侧狭细处,以改善其外形。结果临床应用6例,再造拇指全部存活。术后随访3~24个月,再造拇指外形美观,感觉运动恢复满意。结论用第二足趾跖侧菱形皮瓣转移改形法再造拇指,能明显改善第二足趾的外形,使再造拇指更美观。  相似文献   
106.
OBJECTIVE: We reviewed recent literature to assess the impact of hospital caseload, surgeon's caseload and education on long-term outcome following colorectal cancer surgery. METHOD: We searched the MEDLINE and Cochrane Library databases for relevant literature starting from 1992. We selected hospital caseload, surgeon's caseload and surgeon's education, type of hospital, and surgeon's experience as variables of interest. Measures of outcome were recurrence-free survival and overall survival, and for rectal cancer frequency of permanent stoma. We reviewed the 34 studies according to tumour location: colonic cancer, rectal cancer, or colorectal cancer. We described the studies individually and performed a meta-analysis whenever it was considered appropriate. RESULTS: For colonic cancer, overall survival improved with increasing hospital caseload, odds ratio (OR) 1.22 [95% confidence interval (CI) 1.16-1.28], and surgeon's education. For rectal cancer, overall survival improved with increasing hospital caseload, OR 1.38 (95% CI 1.19-1.60), and, possibly by surgeon' education and experience. Cancer-free survival was strongly influenced by surgeon's education. The colostomy rate was less in high caseload hospitals, OR 0.76 (95% CI 0.68-0.85). For colorectal cancer, overall survival improved with surgeon's education. CONCLUSION: The data have provided evidence that long-term survival following colorectal cancer surgery in general improved significantly with increasing hospital caseload and surgeon's education.  相似文献   
107.
目的:观察卡巴胆碱(carbachol,Car)对酵母多糖致多器官功能障碍综合征(MODS)小鼠多脏器功能和结构损伤的防护作用。方法:采用腹腔注射酵母多糖的方法复制小鼠MODS模型。雄性C57BL/6小鼠随机分为正常对照组(n=10),MODS 6、24、48 h组(n=30)和MODS Car 6、24、48 h防治组(n=30)。MODS组在致伤后腹腔注入生理盐水;MODS Car防治组在致伤前24 h内分3次灌胃注入卡巴胆碱。观察酵母多糖致伤后早期(48h内)动物死亡率,检测各组血丙氨酸转氨酶活性、尿素氮和肌酐水平,镜下观察致伤后48 h动物肝、肺、肾、心等脏器的组织病理学改变。结果:在酵母多糖致伤后48h内,MODS组小鼠死亡率达26.6%,MODS Car防治组的小鼠死亡率为10.0%。MODS组小鼠血浆ALT、BUN和Cr在伤后6h升高,而同时间点经卡巴胆碱预处理的小鼠血浆ALT、BUN和Cr仅略有升高,明显低于MODS组。光镜下观察发现,MODS组小鼠肝脏、肺脏、肾脏和心脏发生明显的病理改变,主要表现为脏器实质细胞浊肿、变性,间质充血、水肿和炎性细胞浸润,而卡巴胆碱防治组小鼠上述病变明显减轻。结论:预防性给予卡巴胆碱可以降低MODS急性期动物的死亡率,减轻脏器功能和结构的损伤,对急性炎症期的脏器损伤具有保护作用。  相似文献   
108.
109.
Background Poor co‐ordination of services can have severe consequences for disadvantaged children with complex needs. Since 2003 national and local governments in England embarked on sweeping reforms aimed at improving and integrating local health, education and social services for children. These were to be organized locally by children's trusts and piloted by 35 children's trust pathfinders. Methods This study described and compared the experience of integrating children's services in all 35 children's trust pathfinders, covering 20% of children in England. It had a prospective mixed‐methods design. Over 3 years we interviewed 147 managers and professionals working in the children's trusts, including 172 semi‐structured interviews, carried out two questionnaire surveys of the 35 children's trusts and analysed official documents. Results In most areas different agencies jointly commissioned children's services, especially for mental health, disabilities and multi‐purpose children's centres, and increasingly pooled finances. Provision of multi‐agency and multi‐professional services was increasing. Professionals generally supported these changes but found them stressful. All children's trusts appointed directors of children's services and established boards representing multiple agencies. Systems for sharing information about individual children were mostly in place but were still underused. Health services were generally less involved in joint work than were local authorities' education and social care services, with notable exceptions. Areas where local authorities and health authorities shared geographical boundaries made most progress. Some children's trusts made few changes beyond their statutory obligations. Conclusion Children's trusts enabled major changes to services in areas where local actors and organizations were motivated and empowered. In other areas the remit of children's trusts was often too broad and vague to overcome entrenched organizational and professional divisions and interests. Policymakers need to balance facilitation of change in areas with dynamic change agents with methods for ensuring that dormant areas and agencies are not left behind.  相似文献   
110.
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