全文获取类型
收费全文 | 63834篇 |
免费 | 4111篇 |
国内免费 | 138篇 |
专业分类
耳鼻咽喉 | 575篇 |
儿科学 | 2550篇 |
妇产科学 | 1688篇 |
基础医学 | 8190篇 |
口腔科学 | 846篇 |
临床医学 | 9215篇 |
内科学 | 11631篇 |
皮肤病学 | 1002篇 |
神经病学 | 5999篇 |
特种医学 | 1188篇 |
外国民族医学 | 4篇 |
外科学 | 5743篇 |
综合类 | 624篇 |
一般理论 | 111篇 |
预防医学 | 8576篇 |
眼科学 | 890篇 |
药学 | 4028篇 |
中国医学 | 120篇 |
肿瘤学 | 5103篇 |
出版年
2023年 | 344篇 |
2022年 | 543篇 |
2021年 | 1284篇 |
2020年 | 845篇 |
2019年 | 1299篇 |
2018年 | 1524篇 |
2017年 | 1176篇 |
2016年 | 1268篇 |
2015年 | 1435篇 |
2014年 | 1983篇 |
2013年 | 3116篇 |
2012年 | 4424篇 |
2011年 | 4817篇 |
2010年 | 2685篇 |
2009年 | 2398篇 |
2008年 | 4256篇 |
2007年 | 4506篇 |
2006年 | 4368篇 |
2005年 | 4437篇 |
2004年 | 4205篇 |
2003年 | 3985篇 |
2002年 | 3645篇 |
2001年 | 719篇 |
2000年 | 624篇 |
1999年 | 709篇 |
1998年 | 753篇 |
1997年 | 657篇 |
1996年 | 530篇 |
1995年 | 527篇 |
1994年 | 464篇 |
1993年 | 377篇 |
1992年 | 370篇 |
1991年 | 333篇 |
1990年 | 300篇 |
1989年 | 270篇 |
1988年 | 256篇 |
1987年 | 224篇 |
1986年 | 227篇 |
1985年 | 231篇 |
1984年 | 233篇 |
1983年 | 204篇 |
1982年 | 239篇 |
1981年 | 220篇 |
1980年 | 165篇 |
1979年 | 113篇 |
1978年 | 135篇 |
1977年 | 61篇 |
1976年 | 71篇 |
1974年 | 86篇 |
1973年 | 60篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
101.
The effectiveness of educational activities on changing the handwashing habits of preschool children was evaluated using parental surveys and direct observations. Baseline handwashing behaviors were observed and recorded, and parents completed a pre-intervention survey. After interventions were administered, post-intervention data was collected on preschoolers' handwashing habits. Children participated in one, three or five handwashing intervention activities. Results of this study indicate that the educational activities implemented resulted in increased knowledge of the importance of proper handwashing and in positive changes in the children's handwashing habits, particularly for the children who participated in all five interventions. 相似文献
102.
Melissa Kang Diana Bernard Michael Booth Susan Quine Garth Alperstein Tim Usherwood David Bennett 《The British journal of general practice》2003,53(497):947-952
BACKGROUND: To adequately address the complex health needs of young people, their access to services, and the quality of services received, must be improved. AIMS: To explore the barriers to service provision for young people and to identify the training needs of primary healthcare service providers in New South Wales (NSW), Australia. DESIGN OF STUDY: A cross-sectional, qualitative study of the perspectives of a range of health service providers. SETTING: A range of primary healthcare organisations across NSW. METHODS: Samples of general practitioners (GPs), youth health workers, youth health coordinators, and community health centre staff were drawn from urban and rural clusters across NSW. Focus groups and interviews were used to identify barriers to service provision and the training needs of service providers. Data were tape recorded, transcribed, and analysed. RESULTS: Barriers to service provision among GPs and community health centre staff included inadequate time, flexibility, skills, and confidence in working with young people, and poor linkages with other relevant services. Training needs included better knowledge of and skills in adolescent health requirements, working with adolescents, and working with other services. Barriers to service provision for youth health workers and coordinators included lack of financial resources and infrastructure. There were few linkages between groups of service providers. CONCLUSION: Models of service provision that allow stronger linkages between service providers, sufficient time for consultation with young people, adequate training and support of health professionals, and flexibility of service provision, including outreach, should be explored and evaluated. 相似文献
103.
104.
Chris Chase Robert F Dougherty Nicola Ray Susan Fowler John Stein 《Optometry and vision science》2007,84(3):229-236
PURPOSE: Many behavioral studies have found impaired perception of dynamic visual stimuli in dyslexia and several neuroimaging studies have found reduced activation of the human motion area MT+ in dyslexia. These results are often interpreted as a magnocellular (MC) deficit in dyslexia. It has also been claimed that colored filters can help dyslexics to read. One defining feature of the MC-pathway is a greater weight for L-cone input than M-cone input, and at most very weak S-cone input. We measured the subjective speed matches between L-, M-, and S-cone isolating stimuli in good and poor readers. METHODS: Subjects performed a speed-matching task with drifting cone-isolating stimuli to find the point of subjective equality between two drifting patterns. Such a task is known to activate cortical area MT+, presumably via the MC-pathway. RESULTS: L- to M-cone speed-match ratios were negatively correlated with single-word (r=-0.46) and irregular-word reading (r=-0.56) but not with non-word reading. CONCLUSIONS: Results suggest that relative L-cone sensitivity within the MC-pathway may limit orthographic reading performance. 相似文献
105.
Dominic O''Sullivan Susan Hooper Lisa McNally Daryll Jagger 《European journal of dental education》2007,11(1):54-59
In 2000, the University of Bristol Dental School Division of Restorative Dentistry carried out a review of the assessment methods used within the undergraduate programme. Following this review, a number of key recommendations were made and the system of formative assessment within the division was changed. Audits were conducted immediately prior to the introduction of the new system and 2 years after it had been introduced, the results of these audits are presented. There was no change in the number of failed appointments between the initial audit and the second audit. There was a reduction in the number of patients treated by more than one student from 25% to 14% (approximating to 3% if student withdrawal from the course is taken into account). The length of time taken to complete treatment reduced between the two audits with more than half of all patients having their treatment completed within 3 months of their initial examination in the second audit. Ninety-five percent of treatment plans were completed in the second audit compared with only 62% in the first audit. In the second audit, the outstanding 5% of cases were signed off as incomplete for satisfactory reasons by the member of supervisory staff (e.g. patients who had moved away or were discharged due to poor attendance). Student comments were mostly positive, the small number of negative comments related to some students being confused by the paperwork in the new system. The overall process has been an extremely positive experience which has resulted in an assessment system with increased clarity which appears to have reduced the stress levels reported by the undergraduate students on the programme and improved the quality of patient care within restorative dentistry. 相似文献
106.
Deacon E. Harle Keri Davies Rakhee Shah Syma Hussain Susan Cowling Tejinder K. Panesar Jonathan Bourton Bruce J. W. Evans 《Ophthalmic & physiological optics》2007,27(1):100-105
Despite the current popularity of binocular indirect ophthalmoscopy, direct ophthalmoscopes are still commonly used by clinicians for fundus examination. They are considered to be expensive, however, and it has been suggested that this cost can prevent their use by healthcare professionals in developing countries. The Optyse Lens Free Ophthalmoscope is a novel direct ophthalmoscope, without a lens focus system, that allows for comparatively inexpensive manufacture and supply. We compared the clarity of view with the Optyse to that with standard direct ophthalmoscopes, over a sequential cohort of patients with a variety of refractive errors and ocular conditions. The grade of clarity of view with the Optyse Lens Free Ophthalmoscope was less than conventional ophthalmoscopes (Wilcoxon signed rank test, p < 0.0001). This grade of clarity of view was not associated with the ametropia of the ophthalmoscopic observation (Spearman r < or = 0.03, p > or = 0.28) but was with the presence of cataracts (chi2 test, p < 0.0001) with both the Optyse and the conventional ophthalmoscopes. Despite its limitations, the retinal view with Optyse was often within acceptable clinical limits suggesting that this relatively inexpensive ophthalmoscope may have a place when cost prohibits any other type of ophthalmoscope use. 相似文献
107.
108.
109.
Long-term effects of cochlear implants in children. 总被引:5,自引:0,他引:5
Susan B Waltzman Noel L Cohen Janet Green J Thomas Roland 《Otolaryngology--head and neck surgery》2002,126(5):505-511
OBJECTIVE: Since 1987, when the use of multichannel cochlear implants was initiated in children, candidacy has expanded; many thousands of children have received these devices, and results have revealed a wide range of performance. However, few long-term studies exist on a large population of these children. There have been concerns expressed that cochlear implant function might degrade over time, that devices and electrodes might migrate and extrude in the growing child, or that there might even be a deleterious effect of long-term stimulation of the cochlear nerve. The purpose of this study was to explore the long-term effects of implantation as a function of performance over time, reimplantation, and educational factors. STUDY DESIGN AND SETTING: We studied 81 children who received implants at a major academic medical center and were followed for 5 to 13 years. RESULTS: Results revealed significant gains in speech perception, use of oral language, and ability to function in a mainstream environment. There was no decrease in performance over time and no significant incidence of device or electrode migration or extrusion, and device failure did not cause a deterioration in long-term outcome. CONCLUSIONS: Multichannel cochlear implants in children provide perception, linguistic, and educational advantages, which are not adversely affected by long-term electrical stimulation. 相似文献
110.
The addition of candesartan cilexetil (Atacand®, Amias®, Biopress®, Kenzen®, Ratacand®) to standard therapy for chronic heart failure (CHF) provided important clinical benefits at little or no additional cost in France, Germany, and the UK, according to a detailed economic analysis focusing on major cardiovascular events and prospectively collected resource-use data from the CHARM-Added and CHARM-Alternative trials in patients with CHF and left ventricular (LV) systolic dysfunction. Results of a corresponding cost-effectiveness analysis showed that candesartan cilexetil was either dominant over placebo or was associated with small incremental costs per life-year gained, depending on the country and whether individual trial or pooled data were used. Preliminary data from a US cost-effectiveness analysis based on CHARM data also showed favorable results for candesartan cilexetil.Two cost-effectiveness analyses of candesartan cilexetil in hypertension have been published, both conducted in Sweden. Data from the SCOPE trial in elderly patients with hypertension, which showed a significant reduction in nonfatal stroke with candesartan cilexetil-based therapy versus non-candesartan cilexetil-based treatment, were incorporated into a Markov model and an incremental cost-effectiveness ratio of €12 824 per quality-adjusted life-year (QALY) gained was calculated (2001 value). Another modelled cost-effectiveness analysis of candesartan cilexetil was based on the ALPINE trial, in which the incidence of new-onset diabetes was significantly lower in patients with newly diagnosed hypertension who were randomized to candesartan cilexetil (with or without felodipine) than among those who received hydrochlorothiazide (with or without atenolol). Although candesartan cilexetil was dominant over hydrochlorothiazide, the ALPINE cost-effectiveness analysis relied on a small number of clinical events and did not evaluate the incremental cost of candesartan cilexetil per life-year or QALY gained.In conclusion, despite some inherent limitations, economic analyses incorporating CHARM data and conducted primarily in Europe have shown that candesartan cilexetil appears to be cost effective when added to standard CHF treatment in patients with CHF and compromized LV systolic function. The use of candesartan cilexetil as part of antihypertensive therapy in elderly patients with elevated blood pressure was also deemed to be cost effective in a Swedish analysis, primarily resulting from a reduced risk of nonfatal stroke (as shown in the SCOPE study); however, the generalizability of results to other contexts has not been established. Cost-effectiveness analyses comparing candesartan cilexetil with ACE inhibitors or other angiotensin receptor blockers in CHF or hypertension are lacking, and results reported for candesartan cilexetil in a Swedish economic analysis of ALPINE data focusing on outcomes for diabetes require confirmation and extension. 相似文献