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   60225篇
  免费   3536篇
  国内免费   44篇
耳鼻咽喉   894篇
儿科学   1832篇
妇产科学   1410篇
基础医学   9053篇
口腔科学   2204篇
临床医学   5676篇
内科学   10927篇
皮肤病学   1485篇
神经病学   6467篇
特种医学   2773篇
外科学   8371篇
综合类   204篇
一般理论   32篇
预防医学   4018篇
眼科学   1171篇
药学   4052篇
中国医学   87篇
肿瘤学   3149篇
  2023年   323篇
  2022年   240篇
  2021年   542篇
  2020年   594篇
  2019年   644篇
  2018年   1306篇
  2017年   1114篇
  2016年   1453篇
  2015年   1176篇
  2014年   1383篇
  2013年   2512篇
  2012年   3181篇
  2011年   3579篇
  2010年   1888篇
  2009年   1254篇
  2008年   3565篇
  2007年   3718篇
  2006年   3508篇
  2005年   3427篇
  2004年   3324篇
  2003年   3330篇
  2002年   3243篇
  2001年   2613篇
  2000年   3288篇
  1999年   1801篇
  1998年   602篇
  1997年   510篇
  1996年   388篇
  1995年   324篇
  1994年   335篇
  1993年   321篇
  1992年   350篇
  1991年   284篇
  1990年   277篇
  1989年   354篇
  1988年   275篇
  1987年   277篇
  1986年   268篇
  1985年   317篇
  1984年   347篇
  1983年   299篇
  1982年   268篇
  1981年   237篇
  1980年   215篇
  1979年   276篇
  1978年   188篇
  1977年   208篇
  1976年   198篇
  1975年   178篇
  1973年   180篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
In a prospective, randomized multicenter trial, 175 patients with abdominal aortic aneurysms were treated by conventional operation. Two types of polyester prostheses (Gelsoft Plus, Vascute Terumo Corp., Hamburg, Germany or Microvel, Boston Scientific, Ratingen, Germany) were selected randomly for implantation. Diameters ranged from 14 to 20 mm. The diameters of the grafts were measured by ultrasound postoperatively, as well as 6, 12, and 24 months after operation. Local and systemic complications were recorded. Dilation of the main body of the “Gelsoft plus” prosthesis was 19% within the first 12 months and 30% for the Microvel prosthesis. Extreme dilation was not observed. Thus, vascular prostheses must be chosen small enough and the dilation of 20–30% should be considered. The most frequent complication was incisional hernia (32%).  相似文献   
52.
BACKGROUND AND PURPOSE: The efficacy of radiation treatment (RT) for plantar heel pain has been reported repeatedly. Yet, the results referring to the pain relief rate, to long-term effects and prognostic factors are not consistent. In this paper, the effectiveness (pain relief rate and long-term results) and prognostic factors of RT for plantar heel pain have been investigated. PATIENTS AND METHODS: From January 2000 to October 2000, 62 patients (73 heels) with painful plantar heel spurs and a minimum pain history of 3 months were treated and evaluated in a prospective study. Mean age was 54 years (range 28-84 years). All patients were treated with a total dose of 5 Gy in seven fractions (= one series), given twice a week at a single-dose sequence of 0.25-0.25-0.5-1.0-1.0-1.0-1.0 Gy (10-MV photons, source-skin distance [SSD] 100 cm, direct portal, field size 12 x 17 cm). The mean duration of heel pain before RT was 26 weeks (= 6.5 months; range 3-120 months). By means of a visual analog scale (VAS) the patients had to self-assess the quantity of their heel pain once before, three times during and four times after RT at a longterm median follow-up of 28 and 40 months. Additionally, the patients had to assess their mechanical heel stress extent during RT. Effectiveness was estimated according to the patients' judgment of pain reduction. RESULTS: A significant reduction of heel pain extent measured by VAS has been observed already during the RT series (before RT: 6.3 +/- 1.5 vs. 3.8 +/- 2.1 at the end of RT; p < 0.001). 6 weeks after RT (FU 1) pain reduction (> 20%) was achieved in 60 heels (82.3%; n = 73), in 64 heels (91.4%; n = 70) after a mean follow-up of 28 months (FU 2), and in 61 heels (89.7%; n = 68) after a mean follow-up of 40 months (FU 3), respectively. Sufficient pain relief (> 80% compared to initial extent) was observed in 18/73 heels (24.6%) at FU 1 (FU 2: 42/70; 60.0%; FU 3: 37/68; 54.4%), including 13/73 heels (17.8%) with complete pain relief (FU 2: 39/70; 55.7%; FU 3: 36/68; 52.9%). Partial improvement (50-80% pain reduction) was observed in 27/73 heels (37.0%) at FU 1 (FU 2: 14/70; 20.0%; FU 3: 15/68; 22.1%), and minor partial improvement (20-50% pain reduction) in 15/73 heels (20.5%) at FU 1 (FU 2: 8/70; 11.4%; FU 3: 9/68; 13.2%), respectively. No change was seen in 13/73 heels (17.8%) at FU 1 (FU 2: 6/70; 8.6%; FU 3: 7/68; 10.3%). Older patients (p = 0.04) and patients who avoided heel stress during the period of RT (p < 0.01) demonstrated a better short-term response (FU 1); both effects were lost 28 and 40 months after RT. Moreover, significant differences in the extent of heel pain reduction by RT were observed in dependence on previous pain duration (at FU 2-3). CONCLUSION: The results confirm the high efficacy of RT in painful plantar spur and add new aspects to formerly published data concerning the time course of changes in heel pain reduction. Pain relief can be expected during and shortly after RT. In addition, the initial success can be transformed into effective long-term results > 2 years after RT; however, further improvement is not to be expected. As a new prognostic factor, the reduction of mechanical heel stress during RT may ameliorate the short-term results, whereas short heel pain history improves the long-term results. Especially for older patients, RT should be taken into consideration as primary treatment.  相似文献   
53.
54.
Isolated fractures of the metacarpal and phalangeal bones are common injuries of the upper extremities. They usually occur at the age of 10–40, whereas the highest incidence is observed in childhood. The results of treatment have an important impact for the practical value of the hand. This article aims to give a brief overview of the different fracture types and their treatment options.  相似文献   
55.
56.
57.

Background  

Hip dislocation in children with cerebral palsy (CP) is a common and severe problem. The dislocation can be avoided, by screening and preventive treatment of children with hips at risk. The aim of this study was to analyse the characteristics of children with CP who develop hip displacement, in order to optimise a hip surveillance programme.  相似文献   
58.
The first part of this serial paper dealt with the medical criteria used in evaluation of the clinical picture caused by physical stress and the evaluation of other candidate causes and was published in issue no. 3/2005 (pp. 711–752) of Trauma and Berufskrankheit. This follow-up paper (II) presents criteria to be used in the evaluation of whether it is necessary to give up the occupations putting the spine at risk and in estimation of the degree of disability.  相似文献   
59.
A recently introduced setup to measure the dynamic interfacial tension of expanding drops was used to compare the adsorption behaviour of a series of lipids at the electrified water∣dichloroethane interface. Phospholipids with saturated carbon chains of different length (DMPC, DPPC, DSPC, DAPC, DBPC), an unsaturated phospholipid (DOPC) and an ethanolamine (DSPE) were compared. It was found that the adsorption decreases with increasing chain length. Also, the increase of the flow rate reduces the degree of adsorption effectively. On the timescale of the experiments, the DSPE, DAPC and DBPC adsorption showed no potential dependence, whereas the adsorption of DOPC was stronger than that of the saturated lipids. Adsorption was modelled using the Langmuir adsorption isotherm; the potential dependence of adsorption is discussed.  相似文献   
60.
Contact urticaria from protein hydrolysates in hair conditioners   总被引:1,自引:0,他引:1  
Protein hydrolysates (PHs) are added to hair-care products (to "repair" broken hair), soaps, bath gels, creams, etc. From one to 22 PHs used in hair-care products (collagen, keratin, elastin, milk, wheat, almond, and silk) were tested in three patient groups: A) 11 hairdressers with hand dermatitis B) 2160 consecutive adults with suspected allergic respiratory disease subjected to routine skin prick tests C) 28 adults with atopic dermatitis.
In group A, all the 22 PHs were tested with scratch and patch tests. In groups B and C, one to three PHs were tested with prick tests. Positive scratch/prick test reactions were seen in 12 patients from three PHs altogether. All were women with atopic dermatitis, and all reacted to at least hydroxypropyl trimonium hydroly:ed collagen (Crotein Q"). In three patients, prick and open tests with a hair conditioner containing Crotein Q were performed with positive results. One patient reported contact urticaria on her hands, and two reported acute urticaria on their head, face, and upper body from a hair conditioner containing Crotein Q. In seven of the eight studied sera, specific IgE to Crotein Q was detected. In conclusion, PHs of hair cosmetics can cause contact urticaria, especially in patients with atopic dermatitis.  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