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   2596142篇
  免费   198646篇
  国内免费   5658篇
耳鼻咽喉   36166篇
儿科学   85119篇
妇产科学   72822篇
基础医学   372724篇
口腔科学   71198篇
临床医学   232357篇
内科学   511766篇
皮肤病学   57161篇
神经病学   213553篇
特种医学   99687篇
外国民族医学   799篇
外科学   392353篇
综合类   56737篇
现状与发展   7篇
一般理论   980篇
预防医学   200583篇
眼科学   59941篇
药学   189247篇
  2篇
中国医学   5436篇
肿瘤学   141808篇
  2019年   21120篇
  2018年   29517篇
  2017年   22262篇
  2016年   25434篇
  2015年   28926篇
  2014年   40539篇
  2013年   60922篇
  2012年   83549篇
  2011年   88954篇
  2010年   52372篇
  2009年   49471篇
  2008年   83581篇
  2007年   89464篇
  2006年   89806篇
  2005年   87789篇
  2004年   84394篇
  2003年   80642篇
  2002年   78588篇
  2001年   115375篇
  2000年   117755篇
  1999年   99488篇
  1998年   30425篇
  1997年   27263篇
  1996年   27019篇
  1995年   25611篇
  1994年   23565篇
  1993年   22099篇
  1992年   77237篇
  1991年   74796篇
  1990年   72761篇
  1989年   70199篇
  1988年   64856篇
  1987年   63531篇
  1986年   60048篇
  1985年   57470篇
  1984年   43837篇
  1983年   37708篇
  1982年   23562篇
  1981年   20958篇
  1979年   39841篇
  1978年   28522篇
  1977年   24103篇
  1976年   22813篇
  1975年   24229篇
  1974年   28753篇
  1973年   27646篇
  1972年   26036篇
  1971年   23882篇
  1970年   22494篇
  1969年   21319篇
排序方式: 共有10000条查询结果,搜索用时 46 毫秒
51.
52.

Objective

Comparative survival between neoadjuvant chemotherapy and adjuvant chemotherapy for patients with cT2-4N0-1M0 non–small cell lung cancer has not been extensively studied.

Methods

Patients with cT2-4N0-1M0 non–small cell lung cancer who received platinum-based chemotherapy were retrospectively identified. Exclusion criteria included stage IV disease, induction radiotherapy, and targeted therapy. The primary end point was disease-free survival. Secondary end points were overall survival, chemotherapy tolerance, and ability of Response Evaluation Criteria In Solid Tumors response to predict survival. Survival was estimated using the Kaplan–Meier method, compared using the log-rank test and Cox proportional hazards models, and stratified using matched pairs after propensity score matching.

Results

In total, 330 patients met the inclusion criteria (n = 92/group after propensity-score matching; median follow-up, 42 months). Five-year disease-free survival was 49% (95% confidence interval, 39-61) for neoadjuvant chemotherapy versus 48% (95% confidence interval, 38-61) for adjuvant chemotherapy (P = .70). On multivariable analysis, disease-free survival was not associated with neoadjuvant chemotherapy or adjuvant chemotherapy (hazard ratio, 1.1; 95% confidence interval, 0.64-1.90; P = .737), nor was overall survival (hazard ratio, 1.21; 95% confidence interval, 0.63-2.30; P = .572). The neoadjuvant chemotherapy group was more likely to receive full doses and cycles of chemotherapy (P = .014/0.005) and had fewer grade 3 or greater toxicities (P = .001). Response Evaluation Criteria In Solid Tumors response to neoadjuvant chemotherapy was associated with disease-free survival (P = .035); 15% of patients receiving neoadjuvant chemotherapy (14/92) had a major pathologic response.

Conclusions

Timing of chemotherapy, before or after surgery, is not associated with an improvement in overall or disease-free survival among patients with cT2-4N0-1M0 non–small cell lung cancer who undergo complete surgical resection.  相似文献   
53.
Metabolism describes the series of chemical reactions that are concerned with the provision of energy to biological systems. They may be divided into reactions involved in energy yield (catabolism: demand exceeds supply), and energy storage (anabolism: supply exceeds demand). Regulation of these pathways is critical for homeostasis, and derangements in metabolism are seen in a wide variety of pathological processes. Understanding metabolism is key to the treatment of many diseases, notably diabetes, as well as underpinning clinical nutritional support.  相似文献   
54.
55.
56.
57.
58.
We report on a child with several café au lait spots in association with a lumbar lipomeningomyelocele as an apparently new association. Cutaneous markers, the identification of which plays a crucial role in the early diagnosis and management of spinal malformations, can accompany occult spinal dysraphism. Herein we report a case of lumbar lipomeningomyelocele associated with an overlying café au lait spot that served as a marker of occult spinal dysraphism. The patient also had segmental café au lait spots on the face, making the association unique.  相似文献   
59.
60.
Pediatric trachyonychia is an acquired nail disease that can cause distress to families. It is a poorly understood disease, and long‐term follow‐up data are lacking. We present an institutional review of 11 children with isolated pediatric trachyonychia followed over time. Children with the diagnosis of pediatric trachyonychia were identified and invited to participate. Pictures were taken on follow‐up and a questionnaire was answered. Exclusion criteria include having another diagnosis at the initial visit that causes nail dystrophy. Eleven patients with the diagnosis of pediatric trachyonychia were available for follow‐up. The mean age of appearance was 2.7 years (range 2–7 yrs) and the average follow‐up was 66 months (range 10–126 mos). Nine patients were treated with potent topical corticosteroids, one used only petrolatum, and one took vitamin supplements. One patient was found to have an additional skin and hair diagnosis of alopecia areata on follow‐up. On follow‐up, 82% noted improvement of the nails, whereas 18% noted no change. A majority of cases of pediatric trachyonychia are isolated and improve with time, regardless of treatment.  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