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   623篇
  免费   55篇
  国内免费   2篇
耳鼻咽喉   3篇
儿科学   31篇
妇产科学   7篇
基础医学   85篇
口腔科学   17篇
临床医学   87篇
内科学   122篇
皮肤病学   9篇
神经病学   28篇
特种医学   12篇
外科学   63篇
综合类   17篇
预防医学   44篇
眼科学   38篇
药学   72篇
中国医学   6篇
肿瘤学   39篇
  2023年   4篇
  2022年   3篇
  2021年   33篇
  2020年   15篇
  2019年   16篇
  2018年   23篇
  2017年   13篇
  2016年   17篇
  2015年   39篇
  2014年   19篇
  2013年   34篇
  2012年   37篇
  2011年   41篇
  2010年   22篇
  2009年   20篇
  2008年   23篇
  2007年   44篇
  2006年   37篇
  2005年   32篇
  2004年   51篇
  2003年   29篇
  2002年   32篇
  2001年   8篇
  2000年   8篇
  1999年   3篇
  1994年   4篇
  1993年   2篇
  1992年   8篇
  1991年   5篇
  1990年   3篇
  1989年   5篇
  1988年   5篇
  1984年   2篇
  1983年   4篇
  1982年   1篇
  1981年   1篇
  1979年   5篇
  1978年   5篇
  1977年   1篇
  1976年   4篇
  1975年   4篇
  1974年   4篇
  1971年   2篇
  1968年   1篇
  1963年   1篇
  1947年   1篇
  1940年   1篇
  1935年   1篇
  1934年   2篇
  1933年   1篇
排序方式: 共有680条查询结果,搜索用时 15 毫秒
1.
Clear‐cell carcinoma (CCC) is an uncommon malignant tumor of minor salivary glands. It characteristically has a low‐grade morphology and a favorable outcome by most reports. An EWSR1‐ATF1 fusion can be detected in the majority of cases. We present a rare case of CCC, which had an aggressive course with the development of cutaneous metastases. Practicing dermatopathologists should be aware of this tumor given its low‐grade appearance and histopathologic resemblance to other primary cutaneous adnexal and metastatic neoplasms.  相似文献   
2.
In low and middle-income countries mammographic breast cancer screening is prohibitively expensive and a cheaper alternative option is to use ultrasound as the primary screening test. In 2009, China launched a breast cancer screening programme for rural women aged 35–64 years with clinical breast examination coupled with ultrasound as the primary tool. Our study aimed to analyse the cost-effectiveness of breast screening compared to no screening among Chinese rural women. We developed a Markov model to estimate the lifetime costs and effects for rural women aged 35 years from a societal perspective. Asymptomatic women in the intervention arm were screened every 3 years before age 64 years. Breast cancer in the non-screening arm can only be diagnosed on presentation of symptoms. Parameter uncertainty was explored using one-way and probabilistic sensitivity analyses. Compared to no screening, breast cancer screening cost $186.7 more and led to a loss of 0.20 quality-adjusted life years (QALYs). Breast screening was more expensive and did harm to health among rural women with an incremental cost-effectiveness ratio (ICER) of $-916/QALY. The sensitivity analysis identified utility loss from false positives as the factor that most influenced the results, but this did not affect the conclusions. In a rural setting with such low breast cancer incidence, screening for asymptomatic disease is not cost-effective with current screening tools. Priority should be given to ensure that symptomatic women have proper access to diagnosis and treatment at an early stage as this will lead to mortality reductions without the usual screening harms.  相似文献   
3.

Objectives

To model the relationship between the three-level (3L) and the five-level (5L) EuroQol five-dimensional questionnaire and examine how differences have an impact on cost effectiveness in case studies.

Methods

We used two data sets that included the 3L and 5L versions from the same respondents. The EuroQol Group data set (n = 3551) included patients with different diseases and a healthy cohort. The National Data Bank data set included patients with rheumatoid disease (n = 5205). We estimated a system of ordinal regressions in each data set using copula models to link responses of the 3L instrument to those of the 5L instrument and its UK tariff, and vice versa. Results were applied to nine cost-effectiveness studies.

Results

Best-fitting models differed between the EuroQol Group and the National Data Bank data sets in terms of the explanatory variables, copulas, and coefficients. In both cases, the coefficients of the covariates and latent factors between the 3L and the 5L instruments were significantly different, indicating that moving between instruments is not simply a uniform re-alignment of the response levels for most dimensions. In the case studies, moving from the 3L to the 5L caused a decrease of up to 87% in incremental quality-adjusted life-years gained from effective technologies in almost all cases. Incremental cost-effectiveness ratios increased, often substantially. Conversely, one technology with a significant mortality gain saw increased incremental quality-adjusted life-years.

Conclusions

The 5L shifts mean utility scores up the utility scale toward full health and compresses them into a smaller range, compared with the 3L. Improvements in quality of life are valued less using the 5L than using the 3L. The 3L and the 5L can produce substantially different estimates of cost effectiveness. There is no simple proportional adjustment that can be made to reconcile these differences.  相似文献   
4.
The purpose of this study was to compare the levels of Lactobacilli (LB) and Streptococcus mutans (SM) colony forming units (CFU) in the saliva of subjects before and after orthodontic appliance placement. This was a controlled, prospective two-group, two-measurement, clinical trial performed on 64 study patients, 12-15 years old. Subjects in the experimental group were sampled for LB and SM in stimulated saliva collected on the same day but prior to band and bracket placement. The subjects in the control group were sampled on their first screening appointment two months prior to band and bracket placement. The second samples of LB and SM were taken from the experimental and control groups after two months. Saliva was transferred to a selective agar carrier and incubated for 48 hours at 37 degrees C / 99 degrees F. LB and SM colonies forming units were compared with standard densities. The experimental group wearing orthodontic appliances had significantly higher mean LB CFU counts than the control group at the 2 month follow-up (3.25 vs. 2.57, p = 0.0036). The two groups, however, did not show any difference in mean SM CFU counts at the 2 month follow-up (3.0 vs. 3.1, p = 0.66). The results of this study showed that a higher number of CFUs of LB were associated with the group wearing orthodontic appliances after two months and may play a role in the increased levels of plaque seen in many orthodontic patients.  相似文献   
5.
Trapani  D.  Giugliano  F.  Uliano  J.  Zia  V. A. A.  Marra  A.  Viale  G.  Ferraro  E.  Esposito  A.  Criscitiello  C.  D’amico  P.  Curigliano  G. 《Breast cancer research and treatment》2021,187(2):323-337
Breast Cancer Research and Treatment - Breast cancer (BC) is a leading cause of morbidity, disability, and mortality in women, worldwide; triple-negative BC (TNBC) is a subtype traditionally...  相似文献   
6.
Introduction: Combination therapy with BRAF and MEK inhibitors is a recommended treatment strategy for metastatic melanoma patients with BRAFV600 mutations. This treatment provides significant response rates and little added toxicity, with relatively improved survival outcomes compared to RAF/MEK inhibitor monotherapy and chemotherapy.

Areas covered: This review covers the pharmacology, efficacy, and toxicity data derived from clinical studies of dabrafenib, trametinib, and the combination thereof. The major downfall of combiDT is the limited durability of response, which is largely due to acquired resistance in the MAPK pathway.

Expert opinion: Future directions of combiDT concentrate on further combinations with immunotherapy or other targeted inhibitors, referred to triple-agent therapy, which may be essential to improving durability of responses and overcoming resistance.  相似文献   
7.
8.
9.
10.
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