全文获取类型
收费全文 | 4071876篇 |
免费 | 301680篇 |
国内免费 | 10213篇 |
专业分类
耳鼻咽喉 | 57472篇 |
儿科学 | 130346篇 |
妇产科学 | 111125篇 |
基础医学 | 568460篇 |
口腔科学 | 116940篇 |
临床医学 | 375161篇 |
内科学 | 789274篇 |
皮肤病学 | 91239篇 |
神经病学 | 337997篇 |
特种医学 | 158541篇 |
外国民族医学 | 1438篇 |
外科学 | 610010篇 |
综合类 | 91174篇 |
现状与发展 | 6篇 |
一般理论 | 1720篇 |
预防医学 | 325251篇 |
眼科学 | 94693篇 |
药学 | 301251篇 |
11篇 | |
中国医学 | 7983篇 |
肿瘤学 | 213677篇 |
出版年
2018年 | 43661篇 |
2017年 | 33588篇 |
2016年 | 38158篇 |
2015年 | 43064篇 |
2014年 | 60631篇 |
2013年 | 92053篇 |
2012年 | 122327篇 |
2011年 | 129806篇 |
2010年 | 77838篇 |
2009年 | 74422篇 |
2008年 | 121821篇 |
2007年 | 129406篇 |
2006年 | 131155篇 |
2005年 | 126801篇 |
2004年 | 122199篇 |
2003年 | 117809篇 |
2002年 | 114653篇 |
2001年 | 187045篇 |
2000年 | 192534篇 |
1999年 | 163293篇 |
1998年 | 48481篇 |
1997年 | 43265篇 |
1996年 | 42903篇 |
1995年 | 41613篇 |
1994年 | 38636篇 |
1993年 | 36149篇 |
1992年 | 129754篇 |
1991年 | 125525篇 |
1990年 | 121333篇 |
1989年 | 117245篇 |
1988年 | 108365篇 |
1987年 | 106747篇 |
1986年 | 100817篇 |
1985年 | 96579篇 |
1984年 | 72640篇 |
1983年 | 62030篇 |
1982年 | 37355篇 |
1981年 | 33615篇 |
1979年 | 66747篇 |
1978年 | 47233篇 |
1977年 | 40022篇 |
1976年 | 37492篇 |
1975年 | 39595篇 |
1974年 | 47988篇 |
1973年 | 45810篇 |
1972年 | 43106篇 |
1971年 | 39923篇 |
1970年 | 37306篇 |
1969年 | 35274篇 |
1968年 | 32452篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
161.
C. O. Onyeaso BDS FWACS M. O. Arowojolu BDS FWACS J. O. Taiwo BDS MSc DDPH RCS Eng 《American journal of orthodontics and dentofacial orthopedics》2003,124(6):714-720
This prospective clinic-based study evaluated the pretreatment periodontal status of the orthodontic patients seen at the University College Hospital, Ibadan, Nigeria, and assessed the relationship between dental aesthetic index (DAI) scores and periodontal status according to community periodontal index of treatment needs (CPITN) scores. One hundred forty five patients-70 (48.3%) males and 75 (51.7%) females from 6 to 45 years (mean 15.8 +/- 7.5)-were seen. World Health Organization (WHO) guidelines were followed in the examination and reporting of the periodontal status, and DAI scores were assessed based on WHO guidelines. The chi-square test was used to determine the association between the DAI and the CPITN scores. Most patients were in the 6-15 (55.9%) or 16-25 (35.9%) age groups. Based on the WHO preferred cumulative calculations of treatment need (TN), 35.2% of the patients had TN 0, 64.9% had TN 1, 24.9% had TN 2, and only 0.7% had TN 3. The relationship between DAI scores and periodontal treatment needs was not statistically significant (P >.05). Although many patients were yet to attain the WHO goal of no more than 1 sextant affected by bleeding or calculus at the age of 15, over one third had satisfactory periodontal health. 相似文献
162.
163.
164.
Four clinical trials of porcine islet transplantation have been reported, and there are verbal reports that clinical trials on much larger scales are continuing in centers in China and Russia. The four reported trials are briefly reviewed and, in the light of the present status of experimental islet xenotransplantation, consideration is given to whether such trials are currently justified. The Ethics Committee of the International Xenotransplantation Association has (1) emphasized the need for encouraging studies in non-human primates before clinical trials should be undertaken, (2) mandatory monitoring for the transfer of porcine microorganisms, and (3) careful regulation and oversight by recognized bodies. Other aspects of the topic, such as the need for informed consent, are briefly discussed. We conclude that, at the present time, more data documenting convincing efficacy, focused on clinically applicable immunosuppressive regimens, are needed to justify the initiation of closely monitored clinical trials. A clinical trial may then be justified even though the potential risk to the patients, and possibly for society, will not be zero. 相似文献
165.
M. Lenartowicz M. Kowal D. Buda-Lewandowska J. Styrna 《Journal of inherited metabolic disease》2003,25(8):647-659
Summary: The mosaic (Atp7a
mo-ms
) is an X-linked, lethal mutation in mice. In mosaic mutant males, many clinical features characteristic of defective copper metabolism have been observed and they die at the age of 15 days, exhibiting strongsimilarities to the brindled and macular mutants. About 4% of the mutant males live to sexual maturity and some of them are fertile. In this paper, alterationsin the structure of the kidney from adult mutants are described. Owing to an inherited defect of efflux, copper is accumulated in the kidney of the mutants up to a toxic level and this leads to severe damage of the renal cortex. Pathological changes in the kidney mostly affected the structure of the renal corpuscle and renaltubules. 相似文献
166.
Colin J McKay 《World journal of surgery》2006,30(12):2234-2235
167.
B Nkgudi K A Robertson J Volmink B M Mayosi 《Suid-Afrikaanse tydskrif vir geneeskunde》2006,96(3):206-208
OBJECTIVE: To determine whether under-reporting of rheumatic fever occurs at hospital, municipal, provincial and national levels of the South African health system. BACKGROUND: Information on the incidence of rheumatic fever (RF) and the prevalence of rheumatic heart disease (RHD) is required for the prevention of valvular heart disease in developing countries. In South Africa, RF was made a notifiable condition in 1989. It has recently been suggested that the reporting of RF cases may be incomplete, possibly because of underreporting by health care professionals and deficient administration of the disease notification system in South Africa. METHOD AND RESULTS: We assessed whether underreporting of RF cases occurs by comparing the numbers of RF cases reported per year at hospital, municipal, provincial and national levels from 1990 to 2004. There was a fall in the number of RF cases reported per year at national and provincial level over the 15 years of observation. A detailed analysis of the number of RF cases reported at hospital, municipal and provincial level for a 5-year period showed that more cases were diagnosed in one hospital (serving a smaller population) than were captured at municipal and provincial level (serving a larger population), suggesting underreporting by health care professionals. There were discrepancies in the number of cases reported at municipal, provincial and national level, suggesting poor administration of the notification system. CONCLUSION: There appears to be underreporting of RF cases by health care professionals, and poor administration of the RF notification system. Health care professionals need to be educated about the statutory requirement to notify all RF cases in South Africa. An effective national disease notification system is required. 相似文献
168.
169.
Claire M Rickard Brigit L Roberts Jonathon Foote Matthew R McGrail 《Dimensions of critical care nursing》2006,25(5):234-242
Research coordinators in intensive care are a growing specialty about which little is known. This cross-sectional study surveyed the Australia and New Zealand Intensive Care Research Coordinators' Group (n = 49) regarding demographics, education, employment history, job structure, and role content. Most research coordinators were highly qualified and experienced nurses who undertake pharmaceutical trials, multicenter projects, departmental medical and nursing research, audits and data registries, and their own projects. 相似文献
170.
Gabi Mueller Claudio Perret Christina M Spengler 《Journal of rehabilitation medicine》2006,38(6):381-386
OBJECTIVE: Respiratory muscle endurance of able-bodied persons, assessed by normocapnic hyperpnoea at 70% of their maximal voluntary ventilation, usually ranges from 10 to 20 minutes. The aim of this study was to determine the level of ventilation that patients with paraplegia and tetraplegia can sustain for 10-20 minutes to later be used as the guideline for respiratory muscle endurance training. DESIGN: Pilot study; cross-over setting. SUBJECTS: Two groups, 8 patients with paraplegia and 6 with tetraplegia. METHODS: Respiratory muscle endurance tests were performed at 3 different intensities of normocapnic hyperpnoea, i.e. 20%, 40% and 60% maximal voluntary ventilation. Subjects performed partial re-breathing from a bag to assure normocapnia. Respiratory endurance was separately analysed for patients with paraplegia and tetraplegia. RESULTS: Mean respiratory endurance times were 46.0, 18.9 and 4.2 minutes at 20%, 40% and 60% maximal voluntary ventilation in patients with tetraplegia and 51.8, 38.8 and 12.2 minutes in patients with paraplegia. The duration differed significantly at 60% maximal voluntary ventilation between the groups. CONCLUSION: Minute ventilation to perform respiratory muscle endurance training can be set at around 40% of maximal voluntary ventilation for patients with tetraplegia and around 60% of maximal voluntary ventilation for patients with paraplegia, as these levels can be sustained for 10-20 minutes. 相似文献