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   199896篇
  免费   15868篇
  国内免费   10820篇
耳鼻咽喉   1818篇
儿科学   2433篇
妇产科学   3908篇
基础医学   23060篇
口腔科学   3417篇
临床医学   25307篇
内科学   32459篇
皮肤病学   2323篇
神经病学   11094篇
特种医学   6932篇
外国民族医学   70篇
外科学   21822篇
综合类   27724篇
现状与发展   34篇
一般理论   35篇
预防医学   12305篇
眼科学   5473篇
药学   19604篇
  197篇
中国医学   9093篇
肿瘤学   17476篇
  2024年   2402篇
  2023年   3788篇
  2022年   7237篇
  2021年   9475篇
  2020年   7303篇
  2019年   6530篇
  2018年   6450篇
  2017年   5694篇
  2016年   5423篇
  2015年   8220篇
  2014年   10156篇
  2013年   9476篇
  2012年   14113篇
  2011年   15384篇
  2010年   9459篇
  2009年   7526篇
  2008年   10227篇
  2007年   10244篇
  2006年   9924篇
  2005年   9844篇
  2004年   6877篇
  2003年   6146篇
  2002年   5237篇
  2001年   4784篇
  2000年   4903篇
  1999年   5103篇
  1998年   2864篇
  1997年   2943篇
  1996年   2263篇
  1995年   2067篇
  1994年   1820篇
  1993年   1202篇
  1992年   1842篇
  1991年   1593篇
  1990年   1319篇
  1989年   1153篇
  1988年   1022篇
  1987年   927篇
  1986年   762篇
  1985年   586篇
  1984年   392篇
  1983年   302篇
  1982年   178篇
  1981年   164篇
  1980年   152篇
  1979年   188篇
  1978年   113篇
  1977年   84篇
  1974年   91篇
  1973年   82篇
排序方式: 共有10000条查询结果,搜索用时 125 毫秒
101.
目的 介绍自行研制的带控制阀种植牙手术骨粉收集器,并观察其临床应用效果.方法 选取2008年5月至2009年10月38例牙种植患者,应用自制的骨粉收集器收集种植窝制备时产生的骨碎屑,并将其用于修复种植体周围骨缺损,其中开窗式骨缺损29处,唇颊(舌)侧种植体颈部角形缺损23处.结果 所有病例术后均无创口感染及裂开,原缺损处局部形态饱满,牙龈无明显退缩,X线片示种植体与周围牙槽骨形成良好的骨结合.结论 应用自制骨粉收集器收集的骨粉修复种植体周围小型骨缺损效果良好,使用方便,具有良好的应用前景.
Abstract:
Objective To introduce a self-developed bone collector designed by the authors and evaluate its effect in clinical application. Methods A self-developed bone collector was used in 38 patients who underwent the dental implant operation from May 2008 to October 2009. During the operation the bone particles were harvested, which was used for the reconstruction of the bone defects around the implant simultaneously. The defects were fenestrate in 29 regions and triangle in 23 regions on buccal or lingual side of the dental implants. Results All cases had no surgical wound infection and dehiscence 7-10 days after operation. Three to six months after implantation, the X-ray showed that all the dental implants had perfect osseointergration and the alveolar bone were successfully augmented. Conclusions Bone debris harvested by self-developed bone collector could repair small peri-implant bone defects, which is simple to use in clinic.  相似文献   
102.
37 cases of mandible of Neolithic adult that both sexes without missing teeth,alveolar bone were studied.The result showed that the location of the mental foramen below the apex of the lower second premolar was the most common(67.97%) in the modern adult,and the location of the mental foramen below between the apex of the lower second premolar and the first molar was the most common (64.86%) in the neolithic adult.  相似文献   
103.
Osteopontin (OPN) is a non-collagenous extracellular matrix (ECM) protein expressed and secreted by several human cancers. This study investigated the expression pattern of OPN during development of oral squamous-cell carcinoma by using 7,12-dimethylbenz[a]anthracene (DMBA)-induced squamous-cell carcinomas in buccal pouch of syrian golden hamsters. We first identified the hamster OPN cDNA sequence by screening of a hamster calvariae cDNA library with a rat OPN cDNA probe. The resulting 1,449 bp of hamster OPN cDNA led to a deduced protein sequence of 305 amino acids containing several putative binding sites to integrins, CD44 receptors, calcium ions and hydroxyapatite, as well as multiple sites for phosphorylation, glycosylation and sulphation. Hamster OPN cDNA was then used as a probe to analyze the expression of OPN mRNA by Northern blot and in situ hybridization analyses of normal and malignant tissues. OPN mRNA was detected in several non-mineralized tissues as well as in mineralized tissues, but was not present in normal hamster buccal epithelium. DMBA-treated hamster buccal pouches expressed OPN mRNA as early as 4 weeks and displayed the highest level of expression at 15 weeks. The specimens treated with DMBA for 15 weeks exhibited histological features of squamous-cell carcinoma, presented microcrystalline deposits and showed OPN expression associated with malignant epithelium and tumor-associated macrophages. To summarize, our results suggest that buccal-pouch carcinogenesis of Syrian golden hamster may constitute an excellent experimental model to study the mechanisms by which OPN is associated with oral cancer pathogenesis, and to validate OPN-based therapeutic approaches to ameliorate oral cancer progression and metastasis.  相似文献   
104.
目的 比较超短波加离子导入疗法(A组)与电刺激加离子导入疗法(B组)治疗创伤性面瘫的效果。方法 对39例创伤性面神经损伤患者进行临床对照研究,通过量化面神经功能评价、神经电图检查及面神经功能的主观评价比较面神经损伤的治疗效果。结果 创伤性面瘫以青年男性多见,损伤程度以中、重度为主;对于神经损伤轻、中度患者,A组与B组均能促进神经恢复,B组神经功能开始恢复时间早于A组。对于神经损伤重度患者,A组与B组神经恢复率高于对照组,两组均不能减少并发症出现率。结论 超短波加离子导入疗法与电刺激加离子导入疗法均能促进面神经损伤的恢复,但对于减少并发症发生率并无帮助。  相似文献   
105.
对与口腔科常用合金材料有关的9种金属离子(Fe、Ni、Ti、Mn、Mo、Cu、Co、Cr、V)的细胞毒性进行了测定和比较。将L-929细胞培养7天后,求得各种离子不同浓度时的细胞相对增殖率,并转换成六级评分以评价试料的毒性程度。结果表明:在0.5~10ppm离子浓度范围,Mo离子无明显毒性;Mn离子虽有一定毒性,但其浓度变化对毒性程度无影响,V离子显示了较强的毒性;其它离子的毒性则随浓度改变而有不同程度的变化。  相似文献   
106.
铸造义齿中网状支架的设计李景辉,宋培智,陈官辉,季秋杰,卢玉春,高银凤在可摘局部义齿修复中,网状支架的合理设计既增加了义齿的强度,又具有传递咬力、分散力、保护口腔内软硬组织的功能[1]。常用形态为园孔形、方格形、楼梯的,网状形、三角形、倒锥形、栅栏形...  相似文献   
107.
Over a 10-year period (1982–1991), a total of 150 patients divided into two groups with varying degrees of oral submucous fibrosis (OSF) were treated by either medical or surgical therapies. Medical treatment involved (a) conservative oral administration of vitamin B-complex, buflomedial hydrochloride and topical triamcinolone acetonide 0.1%, or (b) conventional submucosal injections of a combination of dexamethasone and hyaluronidase, or (c) a combination of both (a) and (b). The surgical group was treated by the excision of fibrotic tissues and covering the defect with split-thickness skin, fresh human amnion, or buccal fat pad (BFP) grafts. Treatment was chosen according to the stage of clinical progression to gain maximal interincisal distance (ID). The cases were followed up by monthly examinations for at least two years, or when possible even longer. A combination of (a) and (b) medical treatment was satisfactory in cases of mild impairment (ID > 20 mm) but in the long term it led to symptomatic relief only. Surgical therapy, on the other hand, when accepted by the patients, led to a significant improvement of trismus in cases of severe limitation (ID < 20 mm). Following this strategy, an additional ID increase was observed in all patients. BFP grafting was particularly successful in diminishing scarring after two years as compared with the other two grafts. Together with a cessation of the betel quid chewing habit before and after therapy, these treatment regimens combined with daily mouth opening exercises were found to be necessary to manage OSF cases in early and advanced stages of progression.  相似文献   
108.
109.
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