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   12911篇
  免费   1108篇
  国内免费   300篇
耳鼻咽喉   68篇
儿科学   527篇
妇产科学   250篇
基础医学   1227篇
口腔科学   5159篇
临床医学   954篇
内科学   960篇
皮肤病学   66篇
神经病学   297篇
特种医学   299篇
外国民族医学   1篇
外科学   1243篇
综合类   1636篇
预防医学   821篇
眼科学   155篇
药学   526篇
  7篇
中国医学   62篇
肿瘤学   61篇
  2024年   24篇
  2023年   234篇
  2022年   253篇
  2021年   430篇
  2020年   475篇
  2019年   472篇
  2018年   420篇
  2017年   433篇
  2016年   497篇
  2015年   473篇
  2014年   802篇
  2013年   998篇
  2012年   723篇
  2011年   831篇
  2010年   720篇
  2009年   625篇
  2008年   612篇
  2007年   622篇
  2006年   559篇
  2005年   507篇
  2004年   427篇
  2003年   405篇
  2002年   332篇
  2001年   253篇
  2000年   235篇
  1999年   190篇
  1998年   210篇
  1997年   174篇
  1996年   153篇
  1995年   132篇
  1994年   108篇
  1993年   104篇
  1992年   104篇
  1991年   84篇
  1990年   82篇
  1989年   57篇
  1988年   69篇
  1987年   56篇
  1986年   62篇
  1985年   53篇
  1984年   53篇
  1983年   33篇
  1982年   42篇
  1981年   34篇
  1980年   24篇
  1979年   26篇
  1978年   19篇
  1977年   18篇
  1976年   20篇
  1975年   21篇
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
61.
目的 :观察高血压患者在监护拔牙过程中血压、心率、心电图变化及手术应激反应的年龄差异 ,探讨安全科学的监护方法。方法 :对 739例高血压患者监护拔牙的临床资料进行回顾性分析。观察高血压患者和不同年龄组高血压患者麻醉前、中、后 ,拔牙中、拔牙后 ,血压、心率变化。结果 :高血压组血压、心率比对照组显著增高、加快 (P <0 .0 1) ;80岁以上年龄组收缩压显著升高 (P <0 .0 1) ,4 9岁以下年龄组收缩压显著降低 (P <0 .0 5 ,P <0 .0 1)。结论 :各种高血压患者特别是高龄高血压患者 ,在分时安全管理下可以接受无痛拔牙。  相似文献   
62.
邓凯雄  张丹 《中国美容医学》2006,15(10):1185-1186,I0007,I0008
目的:了解经固定矫治的正畸患者在牙齿美白治疗后牙齿表面中部出现较规则斑块的成因。方法:分别对正畸及非正畸治疗患者、正畸治疗前后拔除的离体牙进行牙齿美白治疗,对牙列组进行视觉对比,对离体牙组进行扫描电镜对比。结果:经正畸治疗的牙列在美白治疗后牙面有色斑存在,而正畸治疗后拔除的离体牙的扫描电镜结果则显示有釉质-树脂突嵌合层存在。结论:经正畸治疗后牙齿表层的釉质-树脂突嵌合层是导致牙面出现色斑的原因。  相似文献   
63.
腓动脉皮支逆行岛状皮瓣的解剖与应用改进   总被引:6,自引:0,他引:6  
目的探讨腓动脉皮支逆行岛状皮瓣的解剖学基础及临床应用效果。方法采用新鲜及防腐尸体下肢共25肢,对腓动脉皮支进行解剖学观测。于2003年9月~2005年6月收治足跖趾关节处软组织缺损患者10例,男8例,女2例。年龄21~55岁。其中背侧6例,跖侧4例,缺损范围10cm×6cm~15cm×10cm。应用带有外踝上11.0±1.7cm腓动脉固定皮支的腓动脉皮支逆行岛状皮瓣修复,皮瓣范围11.0cm×6.5cm~16.0cm×11.0cm。供区6例直接减张缝合,4例行自体游离皮片覆盖。结果解剖学观测外踝上11.0±1.7cm自腓动脉发出一固定皮支,起始点直径1.45±0.12mm,入深筋膜点距腓肠神经营养血管皮瓣轴线15.70±1.20mm。10例患者术后皮瓣均成活,血运良好,无静脉回流障碍;供区愈合良好。术后获随访6~12个月,皮瓣外形良好,质地、色泽与周边相似,足功能恢复良好,两点辨别觉11~18mm。结论腓动脉皮支逆行岛状皮瓣经改进后血运好,逆转距离长,修复范围大,操作简便,为临床修复足中远端软组织缺损提供了一种新方法。  相似文献   
64.
The purpose of the study was to examine the relationship between the longitudinal development of incisal tooth wear and periodontal conditions in 51 persons. Stone casts obtained at the ages of 15 and 27 yr were used to assess incisal wear according to a graded scale, the Incisal wear Index (Iwl). The wear increase after 12 yr, ΔIwI, was related to the various health index scores at the age of 15 yr, including the Plaque Index (PII) and Gingival Index (GI) systems. The chi-square tests showed a statistically significant association between AIwI and periodontal condition in 15-yr-olds. Thus, relatively low P1I and GI values were accompanied by relatively high AIwI values. It was concluded that in 15-yr-olds, P1I and GI levels are clinical predictors of future wear (ΔIwI) of maxillary and mandibular central incisors. Pocket depth (PD) was a less valuable clinical predictor of such wear.  相似文献   
65.
Difficulties with tooth protectors in endotracheal intubation   总被引:1,自引:0,他引:1  
The suitability of three tooth protectors for routine use during endotracheal intubation was studied in 300 consecutive patients undergoing elective operations under general anaesthesia. The main disadvantages of the protectors were lack of space and the consequent difficulty of guiding the endotracheal tube into the larynx, and poor visibility, especially when the Camo protector was used. These difficulties could be avoided in most cases by cutting off the right angle of the Camo protector. The less experienced anaesthesiologists especially had difficulties with the protectors: 20% of patients in the Camo group were considered impossible to intubate unless the protector was removed. The silicone inlay of the Camo protector melts and becomes adhesive at body temperature, which makes its prolonged use hazardous. Two patients lost a maxillary incisor despite the proper use of a protector (Denex). Thus the use of a tooth protector alone does not guarantee avoidance of dental trauma. Better results could be obtained by improving the design of the protectors and by careful pre-anaesthetic dental examination.  相似文献   
66.
目的 探讨先天性心脏病合并右上腔静脉缺如及永存左上腔静脉畸形的治疗方法。方法 手术治疗2例,在全麻体外循环下行矫治术。1例采用左上腔静脉直接插管法,1例采用心内冠状静脉窦插管法。结果 2例均治愈,远期无心律失常发生。结论 先天性心脏病中,左上腔静脉合并右上腔静脉缺如非常少见,认识不足,是造成漏诊的主要原因。术中应根据情况酌情处理,但无论采取哪种方法,一定要注意对冠状静脉窦口的保护及左上腔静脉引流的通畅。  相似文献   
67.
Limb-body wall complex is a malformation of body and limbs with craniofacial defects. We describe here the epidemiology of this complex using the population-based registry data in the Kanagawa Birth Defects Monitoring Program during the period 1982–1991. Eleven infants (11/428,599 births) with the complex were ascertained in the study. The incidence and spectrum of the defects observed in our cases were similar to those of other studies. The parental ages in the study group were not significantly different from those in the general population. No teratogenic agents and factors were identified in the present study. Most cases were diagnosed prenatally. © 1994 Wiley-Liss, Inc.  相似文献   
68.
10 patients with chronic adult periodontitis who had greater than 1 tooth with infra-bony pockets were treated at the test defects by periodontal flap procedures with implantation of hydroxylapatite particles; the control defects were treated by the same surgical procedures but without the implant. A total of 58 test defects and 59 control defects were treated. Each defect had measurements carried out at given sites on the involved tooth surfaces, the sites being considered for subsequent tabulation purposes under the category of shallow (less than 3 mm) moderate (3-6 mm) and deep (greater than 6 mm) initial pocket depths. There were 146 and 152 shallow sites, 216 and 241 moderate sites and 140 and 133 deep sites, at test and control sites, respectively. Measurements of recession, probing pocket depths and probing attachment levels were made at 6 months and 1, 2, 3 and 4 years. At all sites over the period of the study, for the moderate and deep initial pockets there was a significant reduction in probing depths and an increase in the probing attachment levels. At the 4th year of assessment for the initially deep pockets, the reduction in probing depths was significantly greater for the sites treated with the implant material. In view of the difficult clinical problem posed by the treatment of teeth with deeper periodontal bone defects, further research using either this type of implant material or similar material should be considered.  相似文献   
69.
A Japanese girl was referred to Osaka University Dental Hospital for examination of a tooth-like structure that had erupted following spontaneous exfoliation of a natal tooth in the lower left primary central incisor region. The structure had erupted at 6 months of age, and radiographic and clinical examination showed composition of pulp and dentin, but no enamel. On histological examination, the majority of the dentin area had a tubular dentin-like appearance, while the outer area of the root appeared to be composed of an osteodentin-like substance. Most of the dentin was covered by cementum. These findings suggest that the structure had originated from a developing remnant of the extracted natal tooth, which must have remained in the gingival tissues. We termed this calcified structure a residual natal tooth.  相似文献   
70.
Abstract Background: In recent years, biomaterials are being found and frequently utilized in bone defects. They have also gained significant precedence in hand surgery. Objectives: The respective requirements for such replacement material will be cited and acknowledged in this article. The individual material groups will also be referred to in this review. An introduction to some of the customary bone replacement materials will be cited and concluded with a corresponding recommendation. Conclusion: The implantation of autologous cancellous bone is still regarded today as the “gold standard”. Nevertheless, the usage of bone replacement material can be an enormous advantage in certain indications. The original article can be found online at There was an error in the author’s affiliation and the address for correspondence was incomplete. Please note the correct institution and complete address: Department of Orthopedics and Traumatology, Hand-, Foot- and Reconstructive Surgery, Kreiskrankenhaus Gummersbach GmbH, Germany. Alexander von Friesen, MD Department of Orthopedics and Traumatology, Hand-, Foot- and Reconstructive Surgery Kreiskrankenhaus Gummersbach GmbH Wilhelm-Breckow-Allee 20 51643 Gummersbach Germany Phone (+49/2261) 171-575, Fax -449 e-mail: Friesen@kkh-gummersbach.de  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