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   12421篇
  免费   953篇
  国内免费   3篇
耳鼻咽喉   111篇
儿科学   419篇
妇产科学   311篇
基础医学   1618篇
口腔科学   415篇
临床医学   1350篇
内科学   2247篇
皮肤病学   244篇
神经病学   1211篇
特种医学   539篇
外科学   1563篇
综合类   51篇
一般理论   9篇
预防医学   1258篇
眼科学   88篇
药学   956篇
中国医学   12篇
肿瘤学   975篇
  2023年   102篇
  2022年   44篇
  2021年   154篇
  2020年   185篇
  2019年   200篇
  2018年   379篇
  2017年   359篇
  2016年   345篇
  2015年   300篇
  2014年   320篇
  2013年   666篇
  2012年   851篇
  2011年   930篇
  2010年   437篇
  2009年   304篇
  2008年   875篇
  2007年   954篇
  2006年   812篇
  2005年   749篇
  2004年   681篇
  2003年   721篇
  2002年   650篇
  2001年   361篇
  2000年   465篇
  1999年   246篇
  1998年   84篇
  1997年   54篇
  1996年   48篇
  1995年   64篇
  1994年   63篇
  1993年   44篇
  1992年   65篇
  1991年   37篇
  1990年   50篇
  1989年   50篇
  1988年   57篇
  1987年   49篇
  1986年   41篇
  1985年   57篇
  1984年   74篇
  1983年   53篇
  1982年   62篇
  1981年   55篇
  1980年   38篇
  1979年   30篇
  1978年   27篇
  1977年   21篇
  1975年   21篇
  1974年   22篇
  1973年   26篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Tamoxifen prevents recurrence of breast cancer and is suggested for preventive risk-reducing therapy. Tamoxifen reduces mammographic density, a proxy for therapy response, but little is known about its effects in remodelling normal breast tissue. Our study, a substudy within the double-blinded dose-determination trial KARISMA, investigated tamoxifen-specific changes in breast tissue composition and histological markers in healthy women. We included 83 healthy women randomised to 6 months daily intake of 20, 10, 5, 2.5, 1 mg of tamoxifen or placebo. The groups were combined to “no dose” (0-1 mg), “low-dose” (2.5-5 mg) or “high-dose” (10-20 mg) of tamoxifen. Ultrasound-guided biopsies were collected before and after tamoxifen exposure. In each biopsy, epithelial, stromal and adipose tissues was quantified, and expression of epithelial and stromal Ki67, oestrogen receptor (ER) and progesterone receptor (PR) analysed. Mammographic density using STRATUS was measured at baseline and end-of-tamoxifen-exposure. We found that different doses of tamoxifen reduced mammographic density and glandular-epithelial area in premenopausal women and associated with reduced epithelium and increased adipose tissue. High-dose tamoxifen also decreased epithelial ER and PR expressions in premenopausal women. Premenopausal women with the greatest reduction in proliferation also had the greatest epithelial reduction. In postmenopausal women, high-dose tamoxifen decreased the epithelial area with no measurable density decrease. Tamoxifen at both low and high doses influences breast tissue composition and expression of histological markers in the normal breast. Our findings connect epithelial proliferation with tissue remodelling in premenopausal women and provide novel insights to understanding biological mechanisms of primary prevention with tamoxifen.  相似文献   
2.
3.
Annals of Nuclear Medicine - The Response Evaluation Criteria In Solid Tumors (RECIST) is the most used radiological method for evaluating response after peptide receptor radionuclide therapy...  相似文献   
4.
5.

Aims

To examine the influence of pre-existing psychiatric disorder on the choice of treatment in patients with gynaecological cancer.

Materials and methods

The analyses were based on all patients who underwent surgical treatment for endometrial, ovarian or cervical cancer who were registered in the Danish Gynecological Cancer Database in the years 2007–2014 (3059 patients with ovarian cancer, 5100 patients with endometrial cancer and 1150 with cervical cancer). Logistic regression model and Cox regression model, adjusted for relevant confounders, were used to estimate the effect of pre-existing psychiatric disorder on the course of cancer treatment. Our outcomes were (i) presurgical oncological treatment, (ii) macroradical surgery for patients with ovarian cancer, (iii) radiation/chemotherapy within 30 days and 100 days after surgery and (iv) time from surgery to first oncological treatment.

Results

In the group of patients with ovarian cancer, more patients with a psychiatric disorder received macroradical surgery versus patients without a psychiatric disorder, corresponding to an adjusted odds ratio of 1.24 (95% confidence interval 0.62–2.41) and the chance for having oncological treatment within 100 days was odds ratio = 1.26 (95% confidence interval 0.77–2.10). As for patients with endometrial cancer, all outcome estimates were close to unity. The adjusted odds ratio for oncological treatment within 30 days after surgery in patients with cervical cancer with a history of psychiatric disorder was 0.20 (95% confidence interval 0.03–1.54).

Conclusions

We did not find any significant differences in the treatment of ovarian and endometrial cancer in patients with pre-existing psychiatric diagnoses. When it comes to oncological treatment, we suggest that increased attention should be paid to patients with cervical cancer having a pre-existing psychiatric diagnosis.  相似文献   
6.
7.
Transforaminal injections are sometimes used for the diagnosis and treatment of painful conditions in the lumbar and to a lesser degree in the cervical spine. The technique is most often used when investigating/treating radiculopathy caused by degenerative disease. But how selective are the nerve root blocks? What possible structures other than the intended nerve root are affected from such injections? This study was undertaken in order to try to answer these questions, as no study focusing on the possible spread from the transforaminal selective nerve root blocks in the cervical spine has been performed earlier. In three groups of patients, each group including three patients, we injected three different volumes (0.6, 1.1 and 1.7 ml) with a transforaminal technique in the cervical spine. In all the injections, a small amount of contrast media was added. The spread of the injections were then investigated using multi-slice computed tomography with reconstructions. The imaging revealed a possible effect on other nerve roots than the intended ones when a larger volume was used for the root blocks. The spread was related to the injected volume as well as to local anatomy (size of foraminal area). In this study, only 0.6-ml injections could be accepted for being selective enough for diagnostic investigations.  相似文献   
8.
Summary Maximal oxygen uptake was assessed in 101 randomly selected 8 and 13 year old children. In both age groups a significantly higher aerobic capacity was found in boys than in girls, both in absolute terms and when maximal oxygen uptake was related to body weight, lean body mass and lean leg volume. Among girls, maximal oxygen uptake per kg body weight was lower in the older than in the younger (p<0.05). Estimation of spontaneous physical activity, by means of a questionnaire and the actometry method, indicated that physical activity was greater in children with a high than in those with a low aerobic capacity.  相似文献   
9.
This paper presents a new outline for psychotherapy with personsn with anorexia nervosa. ‘Model on mentalisation’ is the intellectual and empirical framework for this contribution. Mentalisation is defined as the ability to understand feelings, cognitions, intentions and meaning in oneself and in others. The capacity to understand oneself and others is a key determinant of self‐organisation and affect regulation, and is acquired in early attachment relationships. Impaired mentalisation is documented and described as a central psychopathological feature in anorexia nervosa. Psychotherapeutic enterprise with individuals with compromised mentalising capacity should be an activity that is specifically focused on the rehabilitation of this function, with special emphasis on how the body is representing mental states. The paper describes psychotherapeutic goals, stances and techniques. It is intended that this outline will be further developed into manuals as a basis for therapy, training and research. Copyright © 2007 John Wiley & Sons, Ltd and Eating Disorders Association.  相似文献   
10.
Background Chromium allergy has traditionally been caused by occupational skin contact with cement. In 1983, Danish legislation made the addition of ferrous sulphate compulsory in cement to reduce the water‐soluble chromium content to not more than 2 ppm. An effect from this intervention has previously been demonstrated among Danish construction workers. Objectives To investigate the development of chromium allergy among patients with dermatitis tested between 1985 and 2007 in Denmark. Furthermore, to determine causative exposures in patients with chromium allergy. Patients and methods A retrospective analysis of patch test data was performed (n = 16 228) and charts from patients with chromium allergy were reviewed. Comparisons were made using a χ2 test. Logistic regression analyses were used to test for associations. Results The prevalence of chromium allergy decreased significantly from 3·6% in 1985 to 1% in 1995 (Ptrend < 0·001) but increased to 3·3% in 2007 (Ptrend < 0·001). The frequency of clinically relevant cement exposure decreased significantly among patients with chromium allergy from 12·7% in 1989–1994 to 3·0% (P < 0·01) in 1995–2007, whereas the frequency of relevant leather exposure increased significantly from 24·1% during 1989–1994 to 45·5% during 1995–2007 (P < 0·02). Conclusions Chromium allergy is currently increasing in Denmark due to leather exposure.  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