全文获取类型
收费全文 | 8773篇 |
免费 | 1359篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 170篇 |
儿科学 | 88篇 |
妇产科学 | 86篇 |
基础医学 | 172篇 |
口腔科学 | 6607篇 |
临床医学 | 536篇 |
内科学 | 708篇 |
皮肤病学 | 194篇 |
神经病学 | 89篇 |
特种医学 | 24篇 |
外科学 | 721篇 |
综合类 | 28篇 |
一般理论 | 21篇 |
预防医学 | 228篇 |
眼科学 | 26篇 |
药学 | 335篇 |
肿瘤学 | 121篇 |
出版年
2023年 | 340篇 |
2020年 | 104篇 |
2018年 | 217篇 |
2017年 | 328篇 |
2016年 | 376篇 |
2015年 | 451篇 |
2014年 | 471篇 |
2013年 | 481篇 |
2012年 | 230篇 |
2011年 | 234篇 |
2010年 | 391篇 |
2009年 | 582篇 |
2008年 | 238篇 |
2007年 | 197篇 |
2006年 | 196篇 |
2005年 | 151篇 |
2004年 | 134篇 |
2003年 | 192篇 |
2002年 | 146篇 |
2001年 | 200篇 |
2000年 | 170篇 |
1999年 | 210篇 |
1998年 | 307篇 |
1997年 | 302篇 |
1996年 | 311篇 |
1995年 | 266篇 |
1994年 | 245篇 |
1993年 | 192篇 |
1992年 | 222篇 |
1991年 | 170篇 |
1990年 | 172篇 |
1989年 | 121篇 |
1988年 | 152篇 |
1987年 | 125篇 |
1986年 | 100篇 |
1985年 | 105篇 |
1984年 | 112篇 |
1983年 | 100篇 |
1982年 | 95篇 |
1981年 | 71篇 |
1980年 | 50篇 |
1979年 | 47篇 |
1978年 | 55篇 |
1977年 | 45篇 |
1975年 | 36篇 |
1958年 | 49篇 |
1957年 | 50篇 |
1956年 | 42篇 |
1955年 | 45篇 |
1954年 | 38篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
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
43.
PETER B. AMSTERDAM M.D. JAMES E. TCHENG M.D. 《Journal of interventional cardiology》1997,10(4):249-263
A large body of evidence supports the critical role of thrombus formation in the pathogenesis of acute MI as well as the early ischemic complications after percutaneous coronary interventions. Both platelets and the plasma proteins involved in fibrin formation are intimately involved in the thrombotic process. Recently, pharmacological agents that hinder fibrin formation and platelet activation or aggregation have been developed. These drugs are being tested in patients with acute MI, in conjunction with thrombolytic agents, and in patients undergoing percutaneous coronary interventions. So far, the antiplatelet agents appear very promising in the area of percutaneous coronary intervention. Information on their role in acute myocardial infarction is still too preliminary to draw conclusions. Results with antithrombin agents have been less promising. This article will briefly describe the mechanisms of thrombus formation, detail the mechanism of action of available antithrombotic pharmacological agents, and review recent clinical trials of these agents. 相似文献
44.
45.
NAVIN C. NANDA M.D. SAYED MOHAMMED ABD-EL RAHMAN M.D. GAJENDRA KHATRI M.D. GOPAL AGRAWAL M.D. ADEL A. EL-SAYED M.D. HASSAN A. SHEHATA HASSANIAN M.D. MOHAMMAD KAMRAN M.D. JAMES KIRKLIN M.D. DAVID C. McGIFFIN M.D. WILLIAM L. HOLMAN M.D. ALBERT D. PACIFICO M.D. 《Echocardiography (Mount Kisco, N.Y.)》1995,12(6):619-628
In the present study, we compared three-dimensionally (3-D) reconstructed images with multiplane two-dimensional (2-D) transesophageal echocardiographic (TEE) images in 17 patients with various cardiac masses and defects. To overcome the problem of making measurements from 3-D reconstructed images, we carefully "dissected" the 3-D dataset using paraplane and anyplane 2-D sections, which were then used to obtain the maximum sizes of the cardiac masses and defects. Of the 15 vegetations and 9 abscesses detected by 3-D TEE in 7 patients, only 8 (53%) vegetations and 4 (44%) abscesses were detected by multiplane 2-D TEE (P < 0.02). Also, the exact anatomical location, shape, geometry, and extent of various cardiac masses and defects were more clearly delineated by 3-D than 2-D TEE. The maximum dimensions of cardiac masses and defects were larger by 3-D than by 2-D TEE in 17 (89%) of the 19 lesions available for comparison (P < 0.002). In addition, 3-D TEE correlated more closely than 2-D TEE when compared to surgical measurements in three patients in whom they were available. Thus, it would appear that in several instances, the exact size of the cardiac lesion could only be assessed by analysis of the 3-D volumetric dataset. Out preliminary study has demonstrated the superiority of transesophageal 3-D reconstruction over multiplane 2-D TEE in both qualitative and quantitative assessment of various cardiac mass lesions and pathological defects. 相似文献
46.
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
47.
Pia Andersson RDH Ingalill R. Hallberg RNT PhD Stefan Renvert DDS PhD 《Special care in dentistry》2002,22(5):181-186
The aim of this study was to test the inter-rater reliability of a revised oral assessment guide (ROAG) for patients residing in a geriatric rehabilitation ward. A consecutive sample of 140 patients was recruited for the study. Oral assessments were performed for 133 newly admitted patients by one registered nurse (RN) during a period of six months. A dental hygienist (DH) carried out 103 oral assessments during the same half-year. For 66 patients, the RN and the DH performed independent assessments. There was an agreement between the RN and the DH in the majority of the independent assessments, except for tongue and teeth/dentures. The percentage agreement exceeded 80 percent. Inter-rater agreement measured by Cohen's Kappa coefficient ranged from moderate to very good and percentage agreement had a range of 58 to 91 percent. The agreement was highest in assessment of voice and swallowing (91%). Assessments of teeth and dentures seemed to be most difficult for the RN to evaluate. ROAG was found to be a clinically useful assessment tool. Additional education and training is needed to improve the reliability of the oral assessments and should include continuous support from a dental hygienist as well as a pictorial manual on how to use the ROAG. 相似文献
48.
49.
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
50.