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   55032篇
  免费   4139篇
  国内免费   1588篇
耳鼻咽喉   436篇
儿科学   1732篇
妇产科学   1732篇
基础医学   6328篇
口腔科学   1236篇
临床医学   8102篇
内科学   6858篇
皮肤病学   679篇
神经病学   2405篇
特种医学   2572篇
外国民族医学   20篇
外科学   3890篇
综合类   10944篇
现状与发展   11篇
一般理论   2篇
预防医学   3736篇
眼科学   1018篇
药学   2911篇
  79篇
中国医学   1525篇
肿瘤学   4543篇
  2024年   146篇
  2023年   801篇
  2022年   1754篇
  2021年   2275篇
  2020年   2342篇
  2019年   1821篇
  2018年   1747篇
  2017年   1740篇
  2016年   2115篇
  2015年   1922篇
  2014年   3505篇
  2013年   3599篇
  2012年   3065篇
  2011年   3407篇
  2010年   2651篇
  2009年   2686篇
  2008年   2584篇
  2007年   2831篇
  2006年   2634篇
  2005年   2279篇
  2004年   1985篇
  2003年   1759篇
  2002年   1438篇
  2001年   1310篇
  2000年   992篇
  1999年   836篇
  1998年   733篇
  1997年   717篇
  1996年   633篇
  1995年   572篇
  1994年   517篇
  1993年   459篇
  1992年   370篇
  1991年   359篇
  1990年   314篇
  1989年   252篇
  1988年   286篇
  1987年   230篇
  1986年   181篇
  1985年   197篇
  1984年   128篇
  1983年   86篇
  1982年   98篇
  1981年   89篇
  1980年   80篇
  1979年   69篇
  1978年   43篇
  1977年   25篇
  1976年   29篇
  1975年   29篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Current medical procedures used in prenatal screening and diagnosis of handicapping conditions are reviewed. These strategies include ultrasound, amniocentesis, chorionic villus biopsy, restriction enzyme analysis, maternal serum analysis, fetoscopy, and fetal serum analysis. Along with an explanation of each method, advantages, disadvantages, and risks involved with each are provided. An understanding of these procedures by medical and educational personnel is encouraged, and the potential benefits of prenatal identification of handicapping conditions are emphasized.  相似文献   
72.
目的:探讨良恶性肝外胆管梗阻病变的CT表现及其诊断意义。方法:回顾经手术病理证实的肝外胆管梗阻病变76例(良性34例,恶性42例)。结果:肝内胆管呈枯枝状轻中度扩张,肝内外胆管不一致扩张(内轻外重),肝外胆管远段梗阻,梗阻部胆管呈削尖状狭窄,肝外胆管壁呈弥漫环形增厚,对良性梗阻的诊断有重要意义。肝内胆管呈软藤状重度扩张,肝外胆管中段梗阻,梗阻部胆管呈伴或不伴肿块的截断型或突然狭窄型,肝外胆管壁局限不规则增厚,高度揭示恶性梗阻。结论:良恶性肝外胆管梗阻病变均有特征性CT表现,通过分析胆管形态和临床资料基本能判断梗阻的性质。  相似文献   
73.
脾脏钝伤的CT诊断   总被引:2,自引:1,他引:1  
本文回顾性分析了32例脾脏钝伤CT平扫的表现;对脾损伤进行CT分类;指出腹腔积血和脾周血块(“哨兵血块征”)在诊断脾损伤方面的作用。CT平扫诊断钝性脾脏损伤是一种敏感、可靠的方法,可帮助外科医生制订治疗方案。CT平扫诊断钝性脾损伤的灵敏度为94%,诊断正确率为91%  相似文献   
74.
目的 探讨结石性肠梗阻的诊断及治疗。方法 比较腹部平片和B超的术前诊断率。随访患者以了解不同手术方法的得失。结果 腹部平片术前诊断率为22%,辅以B超则上升为66%。4例Ⅰ期手术和3例Ⅱ期手术患者无死亡。无胆管炎发作。结论 仅靠腹部平片易漏诊,辅以B超则能提高术前诊断率。争取回期手术切除胆囊、闭合胆肠瘘,如有困难,则动员患者6-8周后Ⅱ期手术。  相似文献   
75.
Abstract Perioscan requires a plaque sample to detect the presence of enzymes capable of degrading N-benzoyl-DL-arginine-2-naphthylamide (BANA) from relatively few anaerobic periodontal pathogens. Periocheck assays the presence of neutral proteases in crevicular fluid. The aim of this study was to compare these test kits with traditional clinical methods of detecting periodontal disease and to monitor the ability of the kits to reflect the response to initial therapy. 19 patients with moderately severe chronic periodontitis were seen before and after a course of oral hygiene and root instrumentation consisting of 4 appointments. Clinical measurements and test assays were collected at 5 diseased sites and 2 healthy sites in each subject. Complete data from 125 sites were available for statistical analysis. At baseline Periocheck had a sensitivity of 88% and a specificity of 61% whereas Perioscan had a sensitivity of 99% and a specificity of 55%, when related to the clinical diagnosis. A composite clinical assessment, based on improvement or deterioration of one whole unit change of the subjective clinical indices and 2mm changes or greater in probing depth or probing attachment level, revealed 75 sites which improved following treatment, whereas 45 sites did not change and 5 sites deteriorated. The probability that the tests agreed with the clinical outcome after treatment, was calculated as 50.4% for Periocheck and 52% for Perioscan. The diagnostic kits did not reliably reflect the clinical assessment of periodontal disease in the cross sectional study, or the outcome following treatment.  相似文献   
76.
The objective of this article is to describe various radiographic projections which can be used during endodontic therapy. Changes to the angulation of the X-ray beam in relation to the teeth and film can help diagnosis and treatment by producing images which provide additional information not always visible on radiographs taken with standard angulations. For example, changes in angulation can be useful to determine the number and curvature of roots and canals, to identify superimposed roots and to distinguish between anatomical landmarks and apical pathology. Although use of such techniques increases the diagnostic yield of films, it must be appreciated that such views lead to images that are less distinct because of inherent image distortion. Nevertheless, use of the various techniques during endodontics can provide substantial benefit for clinicians in their daily practice.  相似文献   
77.
A critical incident study in child health   总被引:3,自引:0,他引:3  
The critical incident technique is an objective method of analysing doctors' professional behaviour. It extracts the skills which should be taught and assessed in any training programme. In such a study in child health, 438 incidents were collected from general practitioners, paediatricians and others, and analysed according to the problem, the disease, the setting, the skill and the attitude involved. Most of the problems concerned non-specific symptoms (e.g. 'unwell baby', 'fever') and the main skill categories (each with many subheadings) were clinical management (especially at home), the diagnostic process and interpersonal skills. Training of doctors in child health should emphasize the competencies highlighted in this study.  相似文献   
78.
The efficacy of radiology in evaluating dysphagia was studied in 86 patients by comparison to endoscopic findings. In the 66 patients with endoscopic abnormalities radiology was correct in 54, for a sensitivity of 82%. Sensitivity of radiology improved to 95% if mild esophagitis was excluded. In the 20 patients with normal endoscopy, radiology was normal in 18 (90%). Thus radiology proved to be a reliable means of evaluating the esophagus in patients with dysphagia.  相似文献   
79.
原发性甲状腺功能亢进症合并甲状腺癌18例分析   总被引:1,自引:0,他引:1  
目的:探讨原发性甲状腺功能亢进症(甲亢)合并甲状腺癌(甲癌)的诊断和治疗。方法:回顾分析1990年1月于2000年1月手术治疗18例甲亢合并甲癌患者的临床资料,结果:微小癌占83%(15/18)。术前彩超检查15例,14例发现可疑结节;13例行癌侧叶全切除和对侧叶次全切除术,5例行双侧叶次全切除术,其中3例同时行颈淋巴结清扫术,1例二次行颈淋巴结清扫术。随访16例,平均随访7年,1例死于癌肺转移,余者仍存活,结论:术前常规彩超检查发现可疑结节有助于术中冰冻切片病理检查,手术治疗应兼顾甲亢和甲癌。  相似文献   
80.
本文对95例肾病综合征进行分析,探讨了性别、年龄、发病迁延时间、浮肿、蛋白尿、血尿、血压、尿素氮、血浆蛋白、血浆胆固醇、免疫球蛋白、补体C_3与激素反应及分型的关系。认为下列综合分析可做为判定难治性肾病综合征的参考。难治性肾病多分布在7岁以上,激素治疗4~8周血浆蛋白尚未恢复,尿镜检反复出现红细胞及颗粒管型,血清r—球蛋白不低,而补体C_3降低,提示难治性肾病。各种感染常常是造成肾病综合心难以控制,甚至死亡的重要因素。  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