全文获取类型
收费全文 | 53863篇 |
免费 | 8537篇 |
国内免费 | 114篇 |
专业分类
耳鼻咽喉 | 798篇 |
儿科学 | 2194篇 |
妇产科学 | 1833篇 |
基础医学 | 5300篇 |
口腔科学 | 1480篇 |
临床医学 | 8007篇 |
内科学 | 12876篇 |
皮肤病学 | 1003篇 |
神经病学 | 5210篇 |
特种医学 | 964篇 |
外科学 | 5424篇 |
综合类 | 370篇 |
现状与发展 | 3篇 |
一般理论 | 74篇 |
预防医学 | 8419篇 |
眼科学 | 813篇 |
药学 | 2681篇 |
中国医学 | 35篇 |
肿瘤学 | 5030篇 |
出版年
2024年 | 178篇 |
2023年 | 1568篇 |
2022年 | 1142篇 |
2021年 | 2574篇 |
2020年 | 2290篇 |
2019年 | 2060篇 |
2018年 | 2931篇 |
2017年 | 2421篇 |
2016年 | 2812篇 |
2015年 | 2824篇 |
2014年 | 3836篇 |
2013年 | 4537篇 |
2012年 | 4197篇 |
2011年 | 3994篇 |
2010年 | 2794篇 |
2009年 | 2949篇 |
2008年 | 2834篇 |
2007年 | 2718篇 |
2006年 | 2645篇 |
2005年 | 2109篇 |
2004年 | 1788篇 |
2003年 | 1443篇 |
2002年 | 1299篇 |
2001年 | 406篇 |
2000年 | 332篇 |
1999年 | 414篇 |
1998年 | 547篇 |
1997年 | 383篇 |
1996年 | 346篇 |
1995年 | 303篇 |
1994年 | 254篇 |
1993年 | 204篇 |
1992年 | 162篇 |
1991年 | 135篇 |
1990年 | 147篇 |
1989年 | 111篇 |
1988年 | 90篇 |
1987年 | 72篇 |
1986年 | 84篇 |
1985年 | 76篇 |
1984年 | 71篇 |
1983年 | 63篇 |
1982年 | 40篇 |
1981年 | 34篇 |
1980年 | 45篇 |
1979年 | 28篇 |
1978年 | 28篇 |
1977年 | 28篇 |
1975年 | 22篇 |
1972年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 312 毫秒
141.
Jean-Pierre Chanoine MD PhD Sarah Hampl MD FAAP Craig Jensen MD Mark Boldrin MS Jonathan Hauptman MD 李呈亿 《美国医学会杂志》2006,25(1):34-43
背景:儿童和青少年超重和肥胖正迅速增加。在该人群,单纯行为疗法减肥及维持体重下降的效果有限,但是对药物治疗尚未进行广泛的研究。
目的:确定奥利州他(Orlistat)在青少年体重治疗方面的效果及其安个性。
设计、地点和病例:于美国和加拿大32个中心、539例肥胖青少年(12—16岁;体重指数[body mass index,BMI]在第95百分化之上≥2单位)进行的多ln0、54剧(2000年8月至2002年10月)随机双盲研究。
干预:给予奥利司他(n=357)或安慰剂(n=182)120mg,每口3次,持续1年;加适度低热卡饮食(脂肪占30%)、运动和行为治疗。
主要观察指标:BMI变化;二级指标包括腰围和髋用、体重下降、脂质测量以及机体对口服葡萄糖的血糖和胰岛素反心。
结果:至12周时,两组BMI均有下降;此后,奥利司他组体重维持稳定而安慰剂组则超过基线。研究结束时,奥利司他组BMI下降0.55。而安慰剂组则增加0.31(P=0.001)。与安慰剂组的15.7%相比,奥利司他组26.5%的病例BMI下降≥5%(P=0.005);BMI下降≥10%者分别为4.5%和13.3%(P=0.002)。在研究结束时,奥利司他组体重增加0.53kg,安慰剂组增加3.14kg(P〈0.001)。双能X线吸收测量娃示,这种差异可用脂肪体再的变化解释。奥利司他组腰围下降,安慰剂组腰围上升(-1.33cm比+0.12cm;P〈0.05)。奥利司他组发生轻至中度胃肠道不良事件者为9%-50%,安慰剂组为1%~13%。
结论:与安慰剂比较,奥利司他与饮食、运动和行为改善联合可显著改善肥胖青少年体重的治疗。在这个青少年人群,连续使用奥利司他1年并无重要安全问题,尽管奥利司他组胃肠道不良事件较为常见。 相似文献
142.
This study was undertaken to examine the beliefs and practices of dietitians in relation to cancer risk reduction through nutrition. Respondents to the national survey (N=384, 70 percent) were similar in demographic, educational, and professional characteristics to the American Dietetic Association census data. They reported a strong preventive health orientation: mean performance on 10 preventive health behaviors was 77.5 on a 100 point scale. Half (53 percent) believed cancer would be serious if they developed it, 47 percent believed it was not likely that they would. About 20 percent of the respondents felt that the role of nutrition in cancer etiology was unclear. Dietitians believed strong research support existed for increasing whole grains, fruits and vegetables, and fiber to reduce cancer risk but that little evidence supported use of dietary supplements. Dietitians regularly practiced 75 percent of nutrition recommendations they believed to be effective in reducing cancer risk. Beliefs about the effectiveness of a recommendation accounted for the largest percentage of variance on nutritional practices. While dietitians reported many preventive health practices, including following nutrition recommendations, they seemed to be doing so for reasons other than preventing cancer.Nancie S. Merlino is Assistant Professor, Nutrition and Food Science, Wayne State University, Detroit, MI 48202 and James H. Price, Professor of Health Promotion, Department of Health Promotion, University of Toledo, Toledo, OH 43606.Acknowledgement goes to Stephen Jurs, PhD; Fredrick Andres, PhD; and John Kish, PhD for assistance in design and analysis. 相似文献
143.
144.
Priscilla LeMone DSN RN Donna Jones MPH RN 《International journal of nursing terminologies and classifications》1997,8(3):120-128
TOPIC. Nursing assessment of altered sexuality.
PURPOSE. To review salient factors affecting assessment and objective measures available for use in assessment.
SOURCE. Literature specific to nursing assessment of sexuality and to instruments measuring altered sexuality.
CONCLUSIONS. Many standards of care include the assessment of sexuality, and nurses believe it to be an important aspect of care. However, the assessment of altered sexuality does not often occur in actual practice. The use of an objective measure of sexuality is recommended for both initial and on-going assessments in acute-care and community-based settings. 相似文献
PURPOSE. To review salient factors affecting assessment and objective measures available for use in assessment.
SOURCE. Literature specific to nursing assessment of sexuality and to instruments measuring altered sexuality.
CONCLUSIONS. Many standards of care include the assessment of sexuality, and nurses believe it to be an important aspect of care. However, the assessment of altered sexuality does not often occur in actual practice. The use of an objective measure of sexuality is recommended for both initial and on-going assessments in acute-care and community-based settings. 相似文献
145.
146.
Valerie L. Blanco RDH MS Steven M. Levy DDS MPH Ronald L. Ettinger BDS MDS DDSc Henrietta Logan PhD Kathleen C. Buckwalter PhD RN 《Special care in dentistry》1997,17(4):129-132
Little is known about oral health care behaviors of community-dwelling, cognitively impaired elderly (CIE) persons. Few studies have been conducted regarding the actual provision of oral care for CIE persons or the attitudes and concerns about oral health among their caregivers. The CIE person's ability to perform self-care decreases over time, and the role of the caregiver in daily oral care becomes increasingly important. The purpose of this pilot study was to explore the attitudes toward oral health and identify related concerns among caregivers who care for community-dwelling CIE persons. Caregivers were surveyed by means of a self-administered, mailed questionnaire. To maintain confidentiality, an intermediary was used for recruitment and data collection. Overall, 148 caregivers were invited by an intermediary to participate in the survey; only 21 (14%) consented to participate and returned the questionnaire. This paper discusses some of the numerous methodological challenges identified when an attempt was made to survey caregivers' attitudes toward and barriers to providing oral care for a dependent CIE. 相似文献
147.
James D. Bader DDS MPH Mark S. Scurria DDS Daniel A. Shugars DDS PhD 《The Journal of rural health》1994,10(1):26-30
There have been few reports of relative rates of provision of dental health services in rural and urban settings, a comparative measure of access to care in these populations. One part of a statewide survey of active North Carolina general dentists (n=959, response rate=47%) was designed to quantify provision of prosthetic services. To determine contrasting rural and urban rates, responses were analyzed according to dentists'self-report of practice city size using analysis of covariance with percent of insured patients in the practice as the covariate. Mean per-patient-visit rates for crowns, fixed partial dentures, removable partial dentures, and extractions, as well as the distributions of treatment following tooth extraction, differed by city size, with practitioners in the smallest cities reporting treatment distributions reflecting more frequent loss of teeth and less frequent replacement. These differences in patterns of prosthetic care echo the limited existing information describing oral health status, provider supply, and receipt of care, all of which suggest that differential levels of access to care exist and lead to differences in oral health outcomes. 相似文献
148.
LAUREL MELLIN MA RD MARY CROUGHAN-MINIHANE PhD LARRY DICKEY MD MSW MPH 《Journal of the American Dietetic Association》1997,97(10):1133-1138
This study describes changes observed during a 2-year period in participants enrolled in The Solution Method, a developmental skills training program for adult weight management. This Intervention is the adult application of a model of treatment previously used only in the management of pediatric obesity (The Shapedown Program). Developmental skills training integrates understandings and methods from developmental, family systems, biomedical, genetic, and behavioral theories of the etiology of obesity. Twenty-two subjects (mean age=43.4±8.5 years and mean body mass index=33.1+5.3) completed a group intervention based on this method, which was conducted by a registered dietitian and a mental health professional. Questionnaire responses indicated the extent to which their weight was a medical and/ or psychosocial risk. Subjects attended 2-hour weekly sessions for an average of 18 weeks during which they were trained in six developmental skills: strong nurturing, effective limits, body pride, good health, balanced eating, and mastery living. Data, which were collected at the beginning of treatment and at 3, 6, 12, and 24 months, included weight, blood pressure, 7-day exercise recalls, and responses to depression and functioning (psychosocial, vocational, and economic) questionnaires. Participants’ weights decreased throughout the 2-year period of the study: mean weight change was −4.2 kg (3 months), −6.0 kg (6 months), −7.0 kg (12 months), and −7.9 kg (24 months). In addition, compared with baseline values, systolic and diastolic blood pressure, exercise, and depression improved throughout the study period. These improvements were statistically significant at 24 months for weight (p<.01), systolic blood pressure (p<.02), diastolic blood pressure (p<.001), and exercise (p<.001); the results were not statistically significant for depression. Most participants reported improvement in a broad range of aspects of functioning. We conclude that this application of developmental skills training for adult weight management may produce significant long-term beneficial effects. J Am Diet Assoc. 1997;97:1133–1138. 相似文献
149.
Models of Parkinson's disease. 总被引:2,自引:0,他引:2
Parkinson's disease (PD) is a heterogenous disease likely to be caused by more than one specific aetiological factor. In rare familial cases of PD with similar clinical features to the idiopathic form of the disease, the underlying genetic cause has been identified. These PD-associated genes have been manipulated to create animal and cell culture models of the disease that have helped to further our understanding of the pathogenesis of PD, particularly concerning causes of the selective loss of dopaminergic neurons at the molecular level. In addition, these models will aid the future development of rational therapeutic strategies. This study briefly reviews toxin-induced models and the genetics of PD. It focuses on recently developed animal models of PD, as well as in vitro approaches to model the disease. 相似文献
150.
Computer-Assisted Instruction Improves Clinical Reasoning Skills of Dietetics Students 总被引:1,自引:0,他引:1
MARTHA A. RAIDL PhD RD OLIVIA BENNETT WOOD MPH RD JAMES D. LEHMAN PhD WILLIAM D. EVERS PhD RD 《Journal of the American Dietetic Association》1995,95(8)
Objective The effects of a computer-assisted instruction (CAI) tutorial program on learning clinical reasoning skills were compared in undergraduate dietetics students.Design A drill-and-practice program to control for time on task, a tutorial program, and a simulation program, as the test vehicle, were developed. The tutorial and simulation programs presented data on a patient with cardiovascular disease.Setting Subjects were tested in 30 undergraduate dietetics programs.Subjects Participants were 413 undergraduate diet therapy students enrolled in a coordinated program in dietetics (CPD) or a didactic program in dietetics (DPD).Intervention After completion of lectures on cardiovascular disease, subjects were given the drill-and-practice program plus a simulation test (group 1), the tutorial plus a simulation test (group 2), or the simulation test only (group 3).Main outcome measures Scores on the simulation test were compared. Variables included type of CAI, dietetics program, year in school, computer experience, and experience using a medical chart. Mastery of objectives related to lower- and higher-level clinical reasoning skills introduced in the tutorial program was compared.Statistical analysis One-way analysis of variance and Student-Newman Keuls tests were conducted to determine any differences among the three groups. Reliability was determined using the Kuder-Richardson Formula 20.Results The reliability coefficient of the simulation test was 0.93. Group 2 scored higher on the simulation test than group 1 or group 3. As a group, the CPD students scored higher than the DPD students. When CPD and DPD students were divided into the three experimental groups, there was no significant difference between the CPD and DPD student simulation scores. Group 2 mastered all objectives for lower-level reasoning skills and the higher-level decision-making objective better than groups 1 and 3.Applications/conclusions A computer tutorial program enhanced clinical reasoning skills in undergraduate dietetics students. This type of program could be used to supplement many topics taught in diet therapy and provide DPD students with experiential learning before their clinical intern practicums. J Am Diet Assoc. 1995; 95:868–873. 相似文献