全文获取类型
收费全文 | 63315篇 |
免费 | 4584篇 |
国内免费 | 334篇 |
专业分类
耳鼻咽喉 | 635篇 |
儿科学 | 1602篇 |
妇产科学 | 1539篇 |
基础医学 | 7844篇 |
口腔科学 | 1537篇 |
临床医学 | 6358篇 |
内科学 | 14384篇 |
皮肤病学 | 809篇 |
神经病学 | 4999篇 |
特种医学 | 1916篇 |
外国民族医学 | 2篇 |
外科学 | 9740篇 |
综合类 | 1010篇 |
现状与发展 | 1篇 |
一般理论 | 103篇 |
预防医学 | 5253篇 |
眼科学 | 1859篇 |
药学 | 4428篇 |
中国医学 | 139篇 |
肿瘤学 | 4075篇 |
出版年
2023年 | 292篇 |
2022年 | 463篇 |
2021年 | 1156篇 |
2020年 | 724篇 |
2019年 | 1011篇 |
2018年 | 1244篇 |
2017年 | 847篇 |
2016年 | 968篇 |
2015年 | 1136篇 |
2014年 | 1774篇 |
2013年 | 2809篇 |
2012年 | 3775篇 |
2011年 | 4115篇 |
2010年 | 2346篇 |
2009年 | 2191篇 |
2008年 | 4008篇 |
2007年 | 4192篇 |
2006年 | 4020篇 |
2005年 | 4114篇 |
2004年 | 3842篇 |
2003年 | 3454篇 |
2002年 | 3415篇 |
2001年 | 730篇 |
2000年 | 623篇 |
1999年 | 723篇 |
1998年 | 741篇 |
1997年 | 609篇 |
1996年 | 492篇 |
1995年 | 491篇 |
1994年 | 466篇 |
1993年 | 440篇 |
1992年 | 531篇 |
1991年 | 509篇 |
1990年 | 417篇 |
1989年 | 439篇 |
1988年 | 396篇 |
1987年 | 373篇 |
1986年 | 355篇 |
1985年 | 419篇 |
1984年 | 432篇 |
1983年 | 394篇 |
1982年 | 528篇 |
1981年 | 443篇 |
1980年 | 485篇 |
1979年 | 301篇 |
1978年 | 321篇 |
1977年 | 321篇 |
1976年 | 261篇 |
1975年 | 287篇 |
1974年 | 246篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
72.
Glenn A Pacio Paul Visintainer George Maguire Gary P Wormser John Raffalli Marisa A Montecalvo 《Infection control and hospital epidemiology》2003,24(4):246-250
OBJECTIVE: To determine the natural history of colonization with vancomycin-resistant enterococci (VRE), methicillin-resistant Staphylococcus aureus (MRSA), and resistant gram-negative bacilli among long-term-care facility (LTCF) residents. DESIGN: Observational cohort study. SETTING: A 355-bed LTCF with a ventilator unit and a subacute unit. PARTICIPANTS: Residents with colonization or infection with VRE, MRSA, or resistant gram-negative bacilli housed at the LTCF between December 1, 1999, and February 29, 2000. METHODS: Cultures of clinical and surveillance sites were performed at regular intervals. Charts were reviewed for clinical characteristics associated with clearance of colonization. Kaplan-Meier curves were constructed to analyze the number of days to clearance of colonization. RESULTS: Forty-nine residents had 65 episodes of colonization (27 VRE, 30 MRSA, and 8 resistant gram-negative bacilli). Eighteen (28%) of the episodes cleared. The clearance rate was 2.7 episodes per 1,000 person-days. Clearance occurred significantly more often with resistant gram-negative bacilli colonization compared with VRE or MRSA colonization (6 [75%] vs 12 [21%]; P = .007; relative risk, 4.17; 95% confidence interval, 1.26 to 11.8). There was a trend toward longer use of antimicrobial agents among residents with persistent colonization. Infections occurred most frequently with MRSA. The urinary tract was the most common site of infection. CONCLUSION: Among LTCF residents, colonization with resistant gram-negative bacilli is four times more likely to clear than colonization with VRE or MRSA. Performance of surveillance cultures at regular intervals may reduce the need for contact precautions for LTCF residents with resistant gram-negative bacilli colonization. 相似文献
73.
The purpose of this study is to identify correlates of dental student stress. Associations between characteristics of dental students and their stress levels are examined, along with the association of stress with drug use and health problems. A total of 300 out of 315 dental students completed a questionnaire that measured the frequency and stressfulness of 31 stressors; drug use; health problems; and student characteristics including Type A behavior, career commitment, demographics, and lifestyle variables. Characteristics that were associated with a higher stress level were a higher level of Type A behavior and lower level of career commitment. Greater stress was also associated with a greater frequency of health problems. The results suggest an interactional stress model in which the personalities and attitudes of students are important mediators of the stress response. 相似文献
74.
Martin V. Pusic MD George S. Pachev PhD Wendy A. MacDonald MD 《Academic emergency medicine》2007,14(2):138-148
Objectives
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
To explore medical students' use of computer tutorials embedded in a busy clinical setting; to demonstrate that such tutorials can increase knowledge gain over and above that attributable to the clinical rotation itself.
Methods
Six tutorials were installed on a computer placed in a central area in an emergency department. Each tutorial was made up of between 33 and 85 screens of information that include text, graphics, animations, and questions. They were designed to be brief (10 minutes), focused, interactive, and immediately relevant. The authors evaluated the intervention using quantitative research methods, including usage tracking, surveys of faculty and students, and a randomized pretest-posttest study.
Results
Over 46 weeks, 95 medical students used the tutorials 544 times, for an overall average of 1.7 times a day. The median time spent on completed tutorials was 11 minutes (average [SD], 14 [±12] minutes). Seventy-four students completed the randomized study. They completed 65% of the assigned tutorials, resulting in improved examination scores compared with the control (effect size, 0.39; 95% confidence interval = 0.15 to 0.62). Students were positively disposed to the tutorials, ranking them as "valuable." Fifty-four percent preferred the tutorials to small group teaching sessions with a preceptor. The faculty was also positive about the tutorials, although they did not appear to integrate the tutorials directly into their teaching.
Conclusions
Medical students on rotation in a busy clinical setting can and will use appropriately presented computer tutorials. The tutorials are effective in raising examination scores. 相似文献
75.
76.
Effect of pregnancy on panic attacks 总被引:1,自引:0,他引:1
Three women with panic disorder showed marked improvement in their panic symptoms during pregnancy. Such effects might be due to pregnancy's blunting of the sympathoadrenal response to simple physiologic stimuli, effects on barbiturate receptors, or improvement in psychological functioning. 相似文献
77.
This report describes a technique in which deep-seated CNS neoplasms, the volume and shape of which had been determined and stereotactically localized by computer reconstruction of CT data, were vaporized with a carbon dioxide laser attached to a stereotactic frame. The clinical results with 6 patients treated by this technique are presented. 相似文献
78.
L C Ang D G Munoz D Shul D H George 《Brain research. Developmental brain research》1991,61(1):103-109
SMI-32, an antibody which recognizes the non-phosphorylated epitopes on the neurofilament proteins was used to study the morphological changes in the human striate cortex during postnatal development. Striate cortices from 12 autopsied patients with ages ranging from 1 day to 70 years were obtained. Using the avidin-biotin-peroxidase method, the first SMI-32 immunoreactive neurons were identified at sublayers Vb/VIa on the first postnatal day. At 5 months, the next group of neurons to develop immunoreactivity were in IVb. By 15 months, SMI-32 immunoreactive neurons were observed at III, IVa, IVb, V and VI. The changes in SMI-32 immunoreactivity (ir) were stabilized from 3 years and after. The SMI-32 ir in the striate cortex could be a useful morphological correlate for studying developmental diseases affecting the neocortex. 相似文献
79.
80.