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   243792篇
  免费   15303篇
  国内免费   1007篇
耳鼻咽喉   2687篇
儿科学   6208篇
妇产科学   4599篇
基础医学   30644篇
口腔科学   4508篇
临床医学   24768篇
内科学   51340篇
皮肤病学   3606篇
神经病学   24371篇
特种医学   10581篇
外国民族医学   15篇
外科学   38126篇
综合类   2583篇
现状与发展   1篇
一般理论   180篇
预防医学   17001篇
眼科学   5735篇
药学   16093篇
  1篇
中国医学   329篇
肿瘤学   16726篇
  2023年   1362篇
  2022年   2274篇
  2021年   5468篇
  2020年   3103篇
  2019年   5161篇
  2018年   6189篇
  2017年   4577篇
  2016年   5051篇
  2015年   5930篇
  2014年   8573篇
  2013年   11554篇
  2012年   17695篇
  2011年   18400篇
  2010年   10318篇
  2009年   9564篇
  2008年   16250篇
  2007年   17060篇
  2006年   16593篇
  2005年   16386篇
  2004年   15411篇
  2003年   14068篇
  2002年   13520篇
  2001年   2271篇
  2000年   1736篇
  1999年   2324篇
  1998年   2894篇
  1997年   2317篇
  1996年   1975篇
  1995年   1828篇
  1994年   1568篇
  1993年   1534篇
  1992年   1131篇
  1991年   1074篇
  1990年   920篇
  1989年   872篇
  1988年   772篇
  1987年   727篇
  1986年   723篇
  1985年   776篇
  1984年   981篇
  1983年   869篇
  1982年   1083篇
  1981年   1008篇
  1980年   867篇
  1979年   540篇
  1978年   543篇
  1977年   488篇
  1976年   451篇
  1975年   356篇
  1974年   359篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
The parents of a deceased accident victim who had carried a donor card have recently founded the British Organ Donor Society to serve as a support and self help group for donor families, to act as a voice on their behalf, and to promote the carrying of donor cards. O'Donnell describes the initiative taken by the Evans family, calls for a public campaign to increase the use of donor cards, and encourages physicians to adopt a more positive attitude toward approaching the families of potential donors for permission to remove organs.  相似文献   
992.
Summary Twenty-six adult patients with astrocytomas were treated with BCNU (1,3-bis(2-chloroethyl)-1-nitrosourea) 180–240 mg/m2 1.V. every 6–9 weeks, with metronidazole 1.5 g/m2 p. o. 12 h and 1 h before BCNU and again 6 h and 24 h after BCNU. Of twenty-two evaluable patients, 9 (41%) responded with evidence of reduced tumor size on CT scan, 3 (14%) stabilized and 10 (45%) failed. Patients with no prior chemotherapy or radiotherapy, good performance. status, low grade tumors, and age 50 years had the highest response rates, although differences were not statistically significant. Median survival and duration of response have not been reached with a median follow-up time of ten months. Hematological toxicity was dose-limiting and was probably not augmented by the metronidazole. There was one death from infection that was possibly drug-related. Gastrointestinal toxicity was substantial, and was probably increased by the metronidazole.While the combination of BCNU and metronidazole were tolerable, the response rate seen was no higher than that noted for BCNU alone, and further studies using this dose-schedule are not recommended in astrocytomas.Presented at the 13th International Congress of Chemotherapy, Vienna Austria, August 1983.  相似文献   
993.
Thirty-four consenting patients received VM-26 50–100 mg/m2 I.V. before surgical resection of intracerebral tumor, and drug was measured using a high pressure liquid chromatographic technique. Sufficient tumor for analysis was obtained from 29 patients. Brain metastases (13 patients) had higher concentrations of V M-26 than did gliomas (13 patients). Concentrations were comparable in brain metastases and meningiomas (3 patients). Prolonged (24 h) infusion of V M-26 did not appear to result in higher tumor drug concentrations in 5 patients than did rapid (1 h) infusion in 24 patients. Pretreatment with Amphotericin-B 10 mg/m2 12 h and 1 h before VM-26 did not appear to have any effect on VM-26 uptake into 4 intracerebral tumors, although data were limited, and VM-26 concentrations were very high in 1 metastasis. Pretreatment with oral glycerol 500 mg/kg 18 h, 12 h, 6 h, and immediately before I.V. VM-26 may have resulted in increased penetration of VM-26 into 9 tumors, although confirmation is required. Amphotericin-B, glycerol, and operative conditions did not appear to alter VM-26 plasma pharmacokinetics.VM-26 4-demethylepipodophyllotoxin 9-(4-6-O-thenylidene-B-D-glucopyranoside) - VP-16 4-demethylepipodophyllotoxin 9-(4-6-O-ethylidene-B-D-glucopyranoside) Presented in Part at the 74th Annual Meeting of the American Association for Cancer Research, San Diego, California, May 25–28, 183(1).  相似文献   
994.
Quality of Life Research - This study aimed to investigate changes over time in quality of life, perceived stress, and serious psychological distress for individuals diagnosed with COVID-19 in an...  相似文献   
995.
Journal of Public Health - To determine whether statistically distinct classes of smokers exist according to mental health (MH) diagnoses within primary care and to evaluate whether class...  相似文献   
996.
Journal of Occupational Rehabilitation - Purpose: To compare the frequency of General Practitioner (GP) services and the time between first and last GP services (service duration) provided to...  相似文献   
997.
Critically ill patients in the intensive care unit (ICU) have a high risk of developing malnutrition, and this is associated with poorer clinical outcomes. In clinical practice, nutrition, including enteral nutrition (EN), is often not prioritized. Resulting from this, risks and safety issues for patients and healthcare professionals can emerge. The aim of this literature review, inspired by the Rapid Review Guidebook by Dobbins, 2017, was to identify risks and safety issues for patient safety in the management of EN in critically ill patients in the ICU. Three databases were used to identify studies between 2009 and 2020. We assessed 3495 studies for eligibility and included 62 in our narrative synthesis. Several risks and problems were identified: No use of clinical assessment or screening nutrition assessment, inadequate tube management, missing energy target, missing a nutritionist, bad hygiene and handling, wrong time management and speed, nutritional interruptions, wrong body position, gastrointestinal complication and infections, missing or not using guidelines, understaffing, and lack of education. Raising awareness of these risks is a central aspect in patient safety in ICU. Clinical experts can use a checklist with 12 identified top risks and the recommendations drawn up to carry out their own risk analysis in clinical practice.  相似文献   
998.
Alcohol and physical inactivity are risk factors for a variety of cancer types. However, alcohol use often co-occurs with physical activity (PA), which could mitigate the cancer-prevention benefits of PA. Alcohol is integrated into the culture of one of the most popular physical activities for adults in the United States (U.S.), golf. This study examined how alcohol use was associated with total PA, golf-specific PA, and motives for golfing in a national sample of golfers in the U.S. Adult golfers (n = 338; 51% male, 81% White, 46 ± 14.4 years) self-reported alcohol use, golfing behavior and motives, and PA. Most (84%) golfers consumed alcohol, averaging 7.91 servings/week. Golf participation, including days/week, holes/week, and practice hours/week, was not associated with alcohol use. Golfers with stronger social motives were 60% more likely to consume alcohol. Weekly walking (incident risk ratio (IRR) = 7.30), moderate-to-vigorous PA (MVPA; IRR = 5.04), and total PA (IRR = 4.14) were associated with more alcohol servings/week. Golfers’ alcohol use may be higher than the general adult population in the U.S. and contributes 775 extra kilocalories/week, a surplus that may offset PA-related energy expenditure and cancer-protective effects. Alcohol use interventions targeting golfers may facilitate weight loss and reduce cancer risk, especially for golfers motivated by social status.  相似文献   
999.
1000.
Maternal and Child Health Journal - Each year, 3% of infants in the Unites States (US) are born with congenital anomalies, including 3000 with neural tube defects. Multivitamins (MVIs) including...  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