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   5266篇
  免费   448篇
  国内免费   10篇
耳鼻咽喉   52篇
儿科学   142篇
妇产科学   99篇
基础医学   679篇
口腔科学   109篇
临床医学   497篇
内科学   1086篇
皮肤病学   111篇
神经病学   511篇
特种医学   170篇
外国民族医学   6篇
外科学   829篇
综合类   123篇
一般理论   8篇
预防医学   450篇
眼科学   206篇
药学   313篇
中国医学   16篇
肿瘤学   317篇
  2022年   33篇
  2021年   92篇
  2020年   44篇
  2019年   80篇
  2018年   97篇
  2017年   68篇
  2016年   64篇
  2015年   76篇
  2014年   120篇
  2013年   217篇
  2012年   273篇
  2011年   296篇
  2010年   170篇
  2009年   155篇
  2008年   259篇
  2007年   285篇
  2006年   280篇
  2005年   293篇
  2004年   297篇
  2003年   287篇
  2002年   269篇
  2001年   57篇
  2000年   61篇
  1999年   67篇
  1998年   61篇
  1997年   44篇
  1996年   46篇
  1995年   53篇
  1994年   54篇
  1993年   65篇
  1992年   48篇
  1991年   34篇
  1990年   42篇
  1989年   36篇
  1988年   30篇
  1987年   37篇
  1986年   36篇
  1985年   42篇
  1984年   57篇
  1983年   49篇
  1982年   46篇
  1981年   62篇
  1980年   54篇
  1979年   46篇
  1978年   48篇
  1977年   48篇
  1976年   35篇
  1975年   34篇
  1974年   38篇
  1973年   37篇
排序方式: 共有5724条查询结果,搜索用时 421 毫秒
11.
This paper is based on a prospective survey covering 275,600 sight tests by optometrists in England and Wales. It analyses the age and sex distribution of 1402 referrals for suspected glaucoma and 456 confirmed cases of the disease. The proportion of sight tests which led to a confirmed case increased with age, for both sexes, to a maximum at approximately 70 years, and then tended to decline. Cases of glaucoma in people aged 36-51 years accounted for about a tenth of the total, which is more than is generally recognized. Wider adoption of routine tonometry for middle aged people would help to ensure that these cases are detected at an early stage. Confirmed cases of glaucoma in which raised intraocular pressure had not been given as a reason for referral, i.e. probable low tension glaucomas, increased from 5% of patients < 51 years old to 13% of patients > 75 years old. Glaucoma was found to be much more common in men.  相似文献   
12.
Between 1970 and 1990, 104 patients with squamous cell carcinoma (SCC) of the tonsil were treated. The median age was 58 years and 80% of patients were males. Distribution among clinical stages was: stage I, 19 patients; stage II, 12 patients; stage III, 23 patients; and stage IV, 48 patients. More than 70% of patients had initial radiotherapy as definitive treatment irrespective of stage, reflecting the treatment philosophy over much of this period. The overall survival rate was 26% at 5 years, with survival being significantly affected by T stage, clinical stage and age. Clinical node status did not significantly affect survival rates. Good local control of T1N0 cancers was achieved with radiotherapy alone, but patients with more advanced cancers did poorly. We have now moved away from a non-selective policy and use initial surgery combined with postoperative radiotherapy in most patients, reserving radiotherapy alone for mainly early tonsil cancers.  相似文献   
13.
14.
15.
Background: Intravenous infusion of lidocaine decreases postoperative pain and speeds the return of bowel function. The authors therefore tested the hypothesis that perioperative lidocaine infusion facilitates acute rehabilitation protocol in patients undergoing laparoscopic colectomy.

Methods: Forty patients scheduled to undergo laparoscopic colectomy were randomly allocated to receive intravenous lidocaine (bolus injection of 1.5 mg/kg lidocaine at induction of anesthesia, then a continuous infusion of 2 mg [middle dot] kg-1 [middle dot] h-1 intraoperatively and 1.33 mg [middle dot] kg-1 [middle dot] h-1 for 24 h postoperatively) or an equal volume of saline. All patients received similar intensive postoperative rehabilitation. Postoperative pain scores, opioid consumption, and fatigue scores were measured. Times to first flatus, defecation, and hospital discharge were recorded. Postoperative endocrine (cortisol and catecholamines) and metabolic (leukocytes, C-reactive protein, and glucose) responses were measured for 48 h. Data (presented as median [25-75% interquartile range], lidocaine vs. saline groups) were analyzed using Mann-Whitney tests. P < 0.05 was considered statistically significant.

Results: Patient demographics were similar in the two groups. Times to first flatus (17 [11-24] vs. 28 [25-33] h; P < 0.001), defecation (28 [24-37] vs. 51 [41-70] h; P = 0.001), and hospital discharge (2 [2-3] vs. 3 [3-4] days; P = 0.001) were significantly shorter in patients who received lidocaine. Lidocaine significantly reduced opioid consumption (8 [5-18] vs. 22 [14-36] mg; P = 0.005) and postoperative pain and fatigue scores. In contrast, endocrine and metabolic responses were similar in the two groups.  相似文献   

16.
BACKGROUND: Basal cell carcinoma (BCC) is the most common type of skin cancer. One of the main problems with BCC is the risk of local recurrence of the tumor after treatment. This is mainly due to its irregular outgrowths, which cannot be detected clinically. OBJECTIVE: To better understand the tumor morphology and growth pattern of BCC, we tried to develop a method that provides a precise three-dimensional model of the tumor. METHODS: Because Mohs surgery provides the best overview of the tumor and the tumor margins (both lateral and in depth), the reconstruction was based on slides from Mohs surgery. After digitization and processing of the slides, the tumor was then surrounded by a Mohs surgeon on a computer screen. These selections (lines) were used for a three-dimensional reconstruction of the tumor using MedSurf3D software. RESULTS: This method allows three-dimensional reconstruction of any given BCC. The MedSurf3D software enables visualization of a three-dimensional model of the tissue, which is removed during the surgical procedure. CONCLUSIONS: Three-dimensional reconstruction is a fascinating tool that might improve our understanding of the behavior, growth pattern, and tumor morphology of BCCs. This technique might also be useful in other fields of cutaneous oncology, such as the calculation of the tumor volume of melanomas.  相似文献   
17.
18.
Gelrite, a heteropolysaccharide that forms a gel in the presence of cations, was tested in humans for its efficacy as an ophthalmic vehicle by a nonivasive fluorometric technique. Fluorescein was used as the tracer, and its concentration in the anterior chamber was used as the principal measure of bioavailability. The gel afforded a twofold increase in penetration of fluorescein compared with an isotonic buffer solution; this increase is slightly more than can be obtained with simple viscous vehicles. The increase in penetration caused by Gelrite was confirmed by measurements of the contact time of fluorescein in the tear film with the cornea. Earlier experiments with scintigraphy suggested a considerably greater contact time of fluorescein with the cornea when Gelrite was used. However, this increased contact time may be because the technique also measures radioactive tracer that had dried out on the lid margins. Accordingly, significant quantities of fluorescein could be eluted from the lids after the penetration experiments were completed.  相似文献   
19.
The following is a full account of a paper presented at the conference 'Think Global Act Local' held on 29 November 2002 to mark the launch by the four Health and Social Services Boards of the Children's Services Plans 2002-2005. In this paper, I provide a voluntary sector perspective on the changes in the past 3 years in the process of children's services planning, the unique contribution this planning process has to make and the challenges ahead.  相似文献   
20.
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