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   56239篇
  免费   3533篇
  国内免费   110篇
耳鼻咽喉   554篇
儿科学   2385篇
妇产科学   1528篇
基础医学   7018篇
口腔科学   611篇
临床医学   8614篇
内科学   9625篇
皮肤病学   760篇
神经病学   5364篇
特种医学   1014篇
外国民族医学   1篇
外科学   4673篇
综合类   600篇
一般理论   109篇
预防医学   7798篇
眼科学   785篇
药学   3666篇
中国医学   61篇
肿瘤学   4716篇
  2023年   290篇
  2022年   439篇
  2021年   1029篇
  2020年   702篇
  2019年   1063篇
  2018年   1217篇
  2017年   990篇
  2016年   1076篇
  2015年   1250篇
  2014年   1727篇
  2013年   2746篇
  2012年   3963篇
  2011年   4281篇
  2010年   2372篇
  2009年   2142篇
  2008年   3856篇
  2007年   4099篇
  2006年   3952篇
  2005年   4093篇
  2004年   3896篇
  2003年   3655篇
  2002年   3364篇
  2001年   487篇
  2000年   356篇
  1999年   486篇
  1998年   691篇
  1997年   611篇
  1996年   485篇
  1995年   486篇
  1994年   431篇
  1993年   344篇
  1992年   253篇
  1991年   217篇
  1990年   190篇
  1989年   200篇
  1988年   196篇
  1987年   179篇
  1986年   173篇
  1985年   171篇
  1984年   192篇
  1983年   176篇
  1982年   217篇
  1981年   210篇
  1980年   156篇
  1979年   99篇
  1978年   119篇
  1977年   58篇
  1976年   72篇
  1975年   51篇
  1974年   82篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
A case-control study of larynx cancer was conducted within a cohort of automobile workers exposed to metal working fluids, commonly referred to as machining fluids (MF). Results are based on 108 cases of larynx cancer and 5:1 matched controls. Risks associated with specific types of MF, as well as specific components of the fluids were evaluated. Based on a retrospective exposure assessment, lifetime exposures to straight and soluble fluids, grinding particulate, biocides, selected metals, sulfur, and chlorine were examined. Exposure to asbestos and acid mists at two of the three study sites was also characterized. Results suggest that straight mineral oils are associated with almost a two-fold excess in larynx cancer risk. There was also evidence of an association with elemental sulfur, commonly added to straight MF to improve the integrity of the materials under extreme pressure and heat. It is not clear whether sulfur is causally related to an excess relative risk of larynx cancer or whether the observed association is the result of unmeasured confounding by another contaminant or process feature. For example, the high stress operations that require MF enriched with sulfur are also more likely to produce polycyclic aromatic hydrocarbons (PAHs) during the process. Thus, the observed association with sulfur may be due to an association with PAH. The finding of excess risk of laryngeal cancer associated with MF is consistent with several previous reports in the literature. This is the first study, however, to distinguish straight mineral oils from other types of MF. Based on these findings, a general reduction in concentrations of straight mineral oil particulate in occupational environments would be prudent.  相似文献   
82.
Methicillin-resistant Staphylococcus aureus (MRSA) has traditionally been a nosocomial pathogen. However, several recent studies have noted community-acquired MRSA among young, healthy patients with no risk factors or healthcare system exposure. We report the transmission of a strain of community-acquired MRSA in our neonatal intensive care unit.  相似文献   
83.
84.
A review of the literature on gender identity disorders is integrated with a case study presentation of a psychiatrically disturbed nineteen-year-old transvestite youth. Accommodations and interventions made both with this patient and in the day care program for psychiatrically disturbed youths that allowed him to live at home and be maintained despite severe pathology are discussed. Amaro Reyes, M.D. was formerly an attending Psychiatrist in the Community Division of Bronx Children's Psychiatric Center  相似文献   
85.
During an exposure monitoring study, 78 saw maintenance tradesmen were randomly assigned to be interviewed about their exposures using one of two questionnaire formats: open-ended and partly prompted questions about five categories of materials; and detailed prompting about 75 agents. The more open-ended questionnaire elicited fewer exposure responses overall, but more responses about agents not included on the detailed questionnaire. Composite materials and trade name products were more frequently cited as exposures than individual metals or compounds. Validity of responses was ascertained using air measurements (individual metals) or observations of the employees (composite materials). Sums of sensitivities and specificities were very low (near 1.0) for most of the metals for both types of questionnaire. For composite materials, validity improved substantially. Sensitivities with the partly prompted format (0.44–0.85) were always lower than with detailed prompting (0.80–1.00). Specificities were usually, but not always, higher with partial prompting (0.66–0.92) than with detailed prompting (0.18–0.86). Selection of questionnaire format for an epidemiologic study would depend on the likely prevalence of exposure in controls and the effects of trade-offs in sensitivity and specificity.  相似文献   
86.
87.
88.
The effect of weight loss with anorectic medications on sleep apnea, non-insulin-dependent diabetes, and steatohepatitis is illustrated in three cases from practice in a clinical nutrition setting. Prevention of obesity, a chronic disorder, is preferable, but when obesity becomes a major obstacle in the care of patients with respiratory, cardiovascular, and metabolic disorders and osteoarthritis, an intense course of weight reduction using anorectic medications under medical and dietetic guidance is essential for patients' survival and reduction of medical cost.  相似文献   
89.
We reviewed plain radiographs of 215 pediatric patients with surgically proven appendicitis to study the value of plain radiography for diagnosis.  相似文献   
90.
OBJECTIVE: Our objective was to assess the effectiveness of skin care protocols, including a body wash and skin protectant, on skin breakdown in 2 nursing homes. DESIGN: This was a quasi-experimental pretest/posttest design study.Setting and subjects Adult residents (n = 136) of 2 skilled nursing homes consented to participate in this study. Seventy percent were women; the sample average age of 82 years. INSTRUMENTS: A researcher-designed data recording form documented resident demographics, incidence and type of skin breakdown or pressure ulcer, presence of urinary or fecal incontinence, and assessment of the effectiveness of body wash and skin protectant. METHODS: Baseline data on prevalence of pressure ulcers and skin protocol were collected weekly for a 3-month period followed by a week-long educational program by the researchers about skin care and the body wash and skin protectant. During the 3-month trial with the body wash and skin protectant incorporated into routine care, research assistants recorded resident data weekly and researchers again assessed prevalence and incidence of pressure ulcers and skin breakdown weekly. RESULTS: Incorporation of a body wash and skin protectant into a skin care prevention and early intervention protocol in 2 nursing homes documented a decrease in skin breakdowns from 68 pre-intervention to 40 postintervention; the decrease in agency B was statistically significant. There was a statistically significant decrease in stage I and II pressure ulcer incidence overall (pre-intervention = 19.9%, postintervention = 8.1%). Nurses evaluated the body wash and skin protectant as effective for 98% of the time used. CONCLUSION: Implementation of a protocol for skin care along with staff education, including the prophylactic use of a body wash and skin protectant, reduced the incidence of skin breakdown, including pressure ulcers and perineal dermatitis, in 2 long-term care facilities.  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