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   772篇
  免费   69篇
耳鼻咽喉   4篇
儿科学   38篇
妇产科学   10篇
基础医学   89篇
口腔科学   15篇
临床医学   83篇
内科学   184篇
皮肤病学   78篇
神经病学   72篇
特种医学   11篇
外科学   77篇
综合类   1篇
预防医学   68篇
眼科学   11篇
药学   25篇
肿瘤学   75篇
  2022年   7篇
  2021年   10篇
  2020年   10篇
  2019年   12篇
  2018年   18篇
  2017年   22篇
  2016年   17篇
  2015年   16篇
  2014年   25篇
  2013年   35篇
  2012年   40篇
  2011年   32篇
  2010年   20篇
  2009年   14篇
  2008年   29篇
  2007年   38篇
  2006年   37篇
  2005年   37篇
  2004年   35篇
  2003年   39篇
  2002年   46篇
  2001年   35篇
  2000年   28篇
  1999年   24篇
  1998年   15篇
  1997年   7篇
  1996年   11篇
  1995年   6篇
  1994年   11篇
  1993年   3篇
  1992年   9篇
  1991年   13篇
  1990年   15篇
  1989年   18篇
  1988年   7篇
  1987年   12篇
  1986年   14篇
  1985年   4篇
  1984年   3篇
  1983年   3篇
  1982年   4篇
  1979年   5篇
  1977年   2篇
  1975年   4篇
  1974年   14篇
  1973年   4篇
  1970年   9篇
  1967年   6篇
  1966年   2篇
  1965年   3篇
排序方式: 共有841条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: Studies of the association between indoor allergen exposure and the development of allergic diseases have often measured allergen exposure at one point in time. OBJECTIVE: We investigated the variability of house dust mite (Der p 1, Der f 1) and cat (Fel d 1) allergen in Dutch homes over a period of 8 years. METHODS: Data were obtained in the Dutch PIAMA birth cohort study. Dust from the child's mattress, the parents' mattress and the living room floor was collected at four points in time, when the child was 3 months, 4, 6 and 8 years old. Dust samples were analysed for Der p 1, Der f 1 and Fel d 1 by sandwich enzyme immuno assay. RESULTS: Mite allergen concentrations for the child's mattress, the parents' mattress and the living room floor were moderately correlated between time-points. Agreement was better for cat allergen. For Der p 1 and Der f 1 on the child's mattress, the within-home variance was close to or smaller than the between-home variance in most cases. For Fel d 1, the within-home variance was almost always smaller than the between-home variance. Results were similar for allergen levels expressed per gram of dust and allergen levels expressed per square metre of the sampled surface. Variance ratios were smaller when samples were taken at shorter time intervals than at longer time intervals. CONCLUSION: Over a period of 4 years, mite and cat allergens measured in house dust are sufficiently stable to use single measurements with confidence in epidemiological studies. The within-home variance was larger when samples were taken 8 years apart so that over such long periods, repetition of sampling is recommended.  相似文献   
2.
3.
4.
5.
In a study of two groups of nine allergic asthmatic children, consisting of one group with (group I) and one group without (group II) increased nocturnal airflow obstruction, we determined whether an increase in vagal activity, or inflammatory mediators like histamine are responsible for the nocturnal increase in airflow obstruction. The results of investigations in the two groups of asthmatics were compared to the results of an age matched control group. Forced expiratory volume in one second (FEV1) and electrocardiogram recordings of one minute were obtained every 4 hours during 24 hours. Heart rate and sinus arrhythmia gap were used to express vagal activity indirectly. N-methylhistamine was determined in urine samples collected in periods of 4 hours between the measurements. In group I, overall N-methylhistamine excretion was on a higher level than in both other groups, and was significantly higher overnight. Parasympathetic stimulation did not seem of importance to the increase of airflow obstruction at night.This study was supported by a grant from the Nederlands Astma Fonds.  相似文献   
6.
7.
PURPOSE: To determine the feasibility, toxicity, and immunologic effects of vaccination with autologous tumor cells retrovirally transduced with the GM-CSF gene, we performed a phase I/II vaccination study in stage IV metastatic melanoma patients. PATIENTS AND METHODS: Sixty-four patients were randomly assigned to receive three vaccinations of high-dose or low-dose tumor cells at 3-week intervals. Tumor cell vaccine preparation succeeded for 56 patients (88%), but because of progressive disease, the well-tolerated vaccination was completed in only 28 patients. We analyzed the priming of T cells against melanoma antigens, MART-1, tyrosinase, gp100, MAGE-A1, and MAGE-A3 using human leukocyte antigen/peptide tetramers and functional assays. RESULTS: The high-dose vaccination induced the infiltration of T cells into the tumor tissue. Three of 14 patients receiving the high-dose vaccine showed an increase in MART-1- or gp100-specific T cells in the peripheral blood during vaccination. Six patients experienced disease-free survival for more than 5 years, and two of these patients developed vitiligo at multiple sites after vaccination. MART-1- and gp100-specific T cells were found infiltrating in vitiligo skin. Upon vaccination, the T cells acquired an effector phenotype and produced interferon-gamma on specific antigenic stimulation. CONCLUSION: We conclude that vaccination with GM-CSF-transduced autologous tumor cells has limited toxicity and can enhance T-cell activation against melanocyte differentiation antigens, which can lead to vitiligo. Whether the induction of autoimmune vitiligo may prolong disease-free survival of metastatic melanoma patients who are surgically rendered as having no evidence of disease before vaccination is worthy of further investigation.  相似文献   
8.
9.
Between 1973–1987, 40 patients (51 joints) underwent 71 surgical procedures on the temporomandibular joint (TMJ). Indications for surgery included painful TM dysfunction, not alleviated by conservative treatment of at least 12 months' duration, or complete anterior disk dislocation not responding to conservative treatment for three to six months. The incidence of surgical treatment in the period 1983–1987 was 4.1% in a group of 679 patients. The mean follow-up is 5.8 years (range 1–15 years).

At the follow-up examination (37/51) 72.5% of the treated joints appeared to have an excellent or good result; however, 14/51 joints had one or more reoperations (= 14/40 patients: 35%).

The first surgical procedure on the TMJ resulted in an excellent or good result in 29/51 (57%) joints: 6/14 (= 42.9%) high condylectomies; 5/8 (= 62.5%) high condylectomies with a plication procedure; 15/24 (= 62.5%) plication procedure only; 2/2 silastic implants. After one or more reoperations, these figures improved to 10/14 (71%) high condylectomies, 7/8 (87.5%) high condylectomies with a plication procedure, 17/24 (70.8%) plication procedures.

Radiographic changes, including flattening of the condyle, lack of condylar contour, erosion, sclerosis, subcondral cysts, and osteophytes were seen in all (16/16) patients in which a high condylectomy was performed. Out of 22 joints in which only a disk repositioning and plication procedure was performed, only 4/22 showed radiographic changes. The radiographic status was not correlated to the clinical picture at the time of the follow-up examination.  相似文献   
10.
Objectives: Visual media influence the general public's perceptions and attitudes regarding people with mental conditions. This qualitative study investigates the depiction accuracy of dementia's clinical features in motion pictures.Method: Using the search terms ‘dementia’, ‘Alzheimer's disease’ and ‘senility’ movies with release dates between January 2000 and March 2012 were sought on the Internet Movie Database. Based on four selection criteria 23 movies were included. Independently, three researchers watched all movies, scored symptoms, capacities, and behaviors. Scores were discussed and refined during consensus meetings, resulting in a taxonomy of clinical features.Results: Various features are found, most often cognitive symptoms. Behavioral features are also shown – retiring behavior more than agitation – and various emotions, but physical symptoms are rarely depicted. Capacities are infrequently presented and are unrealistic in several of the movies.Conclusion: The clinical picture of dementia portrayed in fictional movies is mild and may be misleading.  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