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   3762篇
  免费   219篇
  国内免费   42篇
耳鼻咽喉   83篇
儿科学   7篇
妇产科学   34篇
基础医学   149篇
口腔科学   2380篇
临床医学   92篇
内科学   44篇
皮肤病学   10篇
神经病学   33篇
特种医学   46篇
外科学   432篇
综合类   405篇
预防医学   73篇
眼科学   59篇
药学   103篇
中国医学   13篇
肿瘤学   60篇
  2024年   9篇
  2023年   82篇
  2022年   76篇
  2021年   128篇
  2020年   119篇
  2019年   147篇
  2018年   149篇
  2017年   90篇
  2016年   129篇
  2015年   152篇
  2014年   256篇
  2013年   261篇
  2012年   218篇
  2011年   222篇
  2010年   198篇
  2009年   186篇
  2008年   183篇
  2007年   177篇
  2006年   188篇
  2005年   146篇
  2004年   126篇
  2003年   124篇
  2002年   93篇
  2001年   91篇
  2000年   80篇
  1999年   51篇
  1998年   49篇
  1997年   55篇
  1996年   46篇
  1995年   25篇
  1994年   13篇
  1993年   23篇
  1992年   17篇
  1991年   10篇
  1990年   11篇
  1989年   7篇
  1988年   8篇
  1987年   14篇
  1986年   6篇
  1985年   8篇
  1984年   8篇
  1983年   5篇
  1982年   9篇
  1980年   5篇
  1979年   4篇
  1978年   4篇
  1977年   5篇
  1976年   3篇
  1975年   2篇
  1974年   3篇
排序方式: 共有4023条查询结果,搜索用时 93 毫秒
31.
牙列缺失后,由于未及时的进行全口义齿修复,常常造成上下颌骨及上下颌弓在形状、大小、位置等方面的不协调,表现为异常颌位,给全口义齿的修复带来一系列的不便,使全口义齿的修复难以达到理想的修复效果。为获得满意的修复效果,异常颌位的排牙成了关键的一步,它不能按常规的排牙方法来进行,必须根据患者的具体情况作适当的调整。只有这样,才有利于全口义齿的固位和稳定,有利于全口义齿功能发挥。  相似文献   
32.
Permeability of the soft tissue-bone system surrounding artificial joints fixed in cancellous bone was measured in four adult dogs after implants had been in place 2 months. Fluid was forced through a cavity formed by removal of the implant, the cavity was capped with a stopper to allow for pressure generation. Surface permeability of the 2-month-old implant cavity was 45 times less than the permeability of freshly drilled holes in cancellous bone. A mathematical model of a rigid implant resting on a biphasic solid-fluid layer showed the fluid carried 90% of the load when the implant cavity permeability was assumed, but only 27% when the freshly drilled permeability was used. The results suggest caution in interpreting finite-element models with bonded interfaces and suggest a possible role of the fluid in biological response at the interface.  相似文献   
33.
羧甲基壳聚糖作为植入可降解缓释微球辅料的实验研究   总被引:6,自引:0,他引:6  
羧甲基壳聚糖作为一种高分子材料 ,具有良好的组织相容性和生物可降解性。本实验试图利用羧甲基壳聚糖作为植入环丙沙星微球的缓释辅料 ,并探索这一剂型的制备工艺、结构形态和体外释药特性。首先我们采用乳化交联技术制备微球 ;然后用扫描电子显微镜、红外光谱、及示差热分析等方法研究微球的结构和形态 ;建立体外持续流动释放系统初步检测微球的体外释放特性。实验结果发现 :微球的结构和形态受制备工艺条件如温度、离子强度、搅拌速度等因素的影响 ;一定工艺条件下制备的环丙沙星微球的体外释放时间可达 7d以上 ,释放行为符合 Higuchi方程。因此 ,我们认为 :羧甲基壳聚糖可作为环丙沙星可降解植入微球的缓释辅料 ;乳化交联技术是制备这一微球的有效方法 ,工艺简单、稳定  相似文献   
34.
目的 :通过对清洁前后的义齿表面进行细菌培养 ,了解加酶义齿清洁剂对口腔厌氧菌的杀菌效果。方法 :从临床选取 8付正在使用的全口义齿 ,随机分为两组 ,其中一组浸泡在加酶义齿清洁剂中 ,另一组不做任何处理 ,再从义齿表面取菌 ,比较细菌培养结果。结果使用加酶义齿清洁剂组经菌落计数lg均值为 0 ;未使用加酶义齿清洁剂组菌落计数lg均值为 3 .4 4。统计学结果表明 :使用加酶义齿清洁剂组与未使用加酶义齿清洁剂组相比较 ,菌落计数有极显著性差异 (P <0 .0 0 1)。结论加酶义齿清洁剂对义齿表面的口腔厌氧菌具有杀灭作用  相似文献   
35.
IntroductionThyroid cancer is the most common type of malignant endocrine cancer. Differentiated thyroid cancer, which includes papillary and follicular cancers, represents majority (90%) of all thyroid cancers and has a favorable prognosis.However, a minority of patients develops loco-regional recurrence.Case reportWe report here a rare case of a 63 years-old man who underwent total thyroidectomy in 2015 for multinodular goiter whose histopathological examination revealed a papillary thyroid carcinoma. He received 6 weeks later a 100 mCi of radioactive iodine therapy. In 2017, he was admitted for multiple cervical lymph nodes with high serum thyroglobulin level (234 ng/mL) which required a bilateral central and lateral neck dissection. He was readmitted in 2019 for multiple subcutaneous neck nodules with high serum thyroglobulin level (197 ng/mL). The histopathological examination of the excised nodules revealed a papillary thyroid carcinoma. The patient showed no sign of recurrence after 2 years follow-up.ConclusionLocal soft tissue recurrence followed surgical implantation should be suspected when nodules are determined alongside the thyroid after previous thyroid surgery. Therapy for these soft tissue implants may be difficult; a comprehensive long-term postoperative evaluation should be completed to minimize the risk of recurrence in cervical soft tissue.  相似文献   
36.
This study is based on an evaluation of patients' opinions of their dentures by means of a questionnaire. The patients had been provided with complete dentures at a university clinic. Of the original sample (n = 139) a test group of 92 patients remained available for the actual study 5 yr after treatment. The replies in the questionnaire were subjected to statistical processing and interpretation. Six clusters could be defined and these were introduced as "scales" representing the patients' score on a specific type of complaint. Apart from the six scales a score was achieved for each patient's overall satisfaction. The correlations between the various scales were calculated with the aid of a computer program. Finally, cross-tabulation was used to see if any significant (inter)correlations could be proved between complaints, satisfaction, and some of the patients' social data. It could be concluded that a correlation exists between complaints of pain and of functional aspects on the one hand and vague complaints on the other hand. There is also a correlation between complaints of looseness of the maxillary denture and complaints about aesthetic factors. Well-fitting and well-functioning dentures, absence of pain, and a socially acceptable appearance contribute much to the patients' satisfaction with dentures. Social variables such as type of insurance (public or private) and marital status influence denture appreciation to a certain extent.  相似文献   
37.
本文讨论了常规设计的游离端义齿存在的问题,并对Kratochvil提出的RPI卡环,结合力学知识,提出了RPI卡环在游离端义齿应用中的优缺点,并通过典型病例介绍和对20名病例随访分析表明,用RPI卡环修复游离端牙齿缺失,可获得较好的临床效果。  相似文献   
38.
为探讨前牙321缺失中不同种植基桩数目对Ni-Cr合金种植固定桥桥支架适合性的影响,采用三维坐标测量法,对3组分别含有1、2、3个种植基桩的五单位双端固定桥试件进行测量.结果显示选择不同的种植基桩数目对同一长度的铸件的精度有差别,含2个基桩的试件精度最高.固位体的理论边缘间隙值在50~150μm,理论浮升量在100~250μm.  相似文献   
39.
This paper describes a technique of using Medpor porous high-density polyethylene implants for nasal reconstruction and chin augmentation. This biocompatible material has been used successfully during the last decade for various applications in the reconstruction of the facial skeleton. Among its most frequent uses are repair of the orbital floor and reconstruction of the burned ear, which became standard methods at many centers. Relatively little experience is, at present, on hand concerning the use of porous polyethylene in reconstruction of the nasal framework. Twenty-three consecutive, difficult nasal reconstructions were performed using this method since 1996. Patients were followed up for from 1 to 3 years (mean, 2 years). The results were durable and stable over the time. Eight patients had saddle nose deformity and 15 had catastrophe noses, mostly referrals, previously operated on from one to four times. My aesthetic goals were correction of the depressed nasal dorsum, creation of an acceptable nasal dorsum in the thick and/or twisted noses, and tip elevation. For nasal applications Medpor is available as a strut or sheet. Its body, once implanted, becomes rapidly vascularized and both soft tissue ingrowth and collagen deposition occur. This was confirmed by the microscopic investigation of biopsies. One patient of Vietnamese origin had an aesthetically pleasing result, but her family refused to accept her westernized nose. This gave me a unique opportunity to study the whole Medpor implant 6 months after implantation. There were two complications, one small implant exposure and one low-virulent infection involving the nasal tip. Following revision and antibiotic treatment, both patients healed without sequel. All reconstructions were successful in restoring nasal aesthetics and function. Four patients underwent chin augmentations with an uneventful clinical course.  相似文献   
40.
The aim of this investigation was to explore the relative importance of psychologic variables in explaining the degree of denture satisfaction in full denture patients. A group of 125 patients who were on a waiting list to have new dentures constructed participated in this study. The patients completed the Dutch version of the Hopkins Symptom Checklist, the Dutch Personality Inventory, a denture satisfaction questionnaire and a denture complaint questionnaire. No relation was found between the personality variables and denture satisfaction as measured by the denture satisfaction questionnaire. When the different aspects of denture satisfaction were measured by means of complaint scales, satisfaction was related to personality traits. Functional complaints of the mandibular denture and complaints about a hollow face were related to the personality trait "extraversion-introversion". Vague denture complaints and complaints about a bulbous face were related to "neuroticism".  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