全文获取类型
收费全文 | 708767篇 |
免费 | 48943篇 |
国内免费 | 1308篇 |
专业分类
耳鼻咽喉 | 9181篇 |
儿科学 | 23423篇 |
妇产科学 | 17671篇 |
基础医学 | 110725篇 |
口腔科学 | 19990篇 |
临床医学 | 63958篇 |
内科学 | 134770篇 |
皮肤病学 | 16199篇 |
神经病学 | 49553篇 |
特种医学 | 25882篇 |
外国民族医学 | 76篇 |
外科学 | 104841篇 |
综合类 | 14947篇 |
现状与发展 | 2篇 |
一般理论 | 160篇 |
预防医学 | 51731篇 |
眼科学 | 16480篇 |
药学 | 54149篇 |
3篇 | |
中国医学 | 2369篇 |
肿瘤学 | 42908篇 |
出版年
2021年 | 5493篇 |
2018年 | 7929篇 |
2017年 | 6144篇 |
2016年 | 6872篇 |
2015年 | 7610篇 |
2014年 | 10373篇 |
2013年 | 15499篇 |
2012年 | 20681篇 |
2011年 | 21719篇 |
2010年 | 12843篇 |
2009年 | 12049篇 |
2008年 | 20172篇 |
2007年 | 21673篇 |
2006年 | 22019篇 |
2005年 | 20573篇 |
2004年 | 20115篇 |
2003年 | 19046篇 |
2002年 | 18530篇 |
2001年 | 36380篇 |
2000年 | 36950篇 |
1999年 | 30418篇 |
1998年 | 7898篇 |
1997年 | 6680篇 |
1996年 | 6983篇 |
1995年 | 6642篇 |
1994年 | 6107篇 |
1993年 | 5600篇 |
1992年 | 22999篇 |
1991年 | 22954篇 |
1990年 | 22329篇 |
1989年 | 22104篇 |
1988年 | 20060篇 |
1987年 | 19439篇 |
1986年 | 18482篇 |
1985年 | 17318篇 |
1984年 | 12711篇 |
1983年 | 10757篇 |
1982年 | 5932篇 |
1979年 | 11548篇 |
1978年 | 8153篇 |
1977年 | 6847篇 |
1976年 | 6605篇 |
1975年 | 7281篇 |
1974年 | 8514篇 |
1973年 | 8157篇 |
1972年 | 7669篇 |
1971年 | 7141篇 |
1970年 | 6896篇 |
1969年 | 6317篇 |
1968年 | 5786篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Bone stock preservation is crucial when performing total hip replacement in young patients. The aim is to save good bone stock
for a possible revision procedure. Furthermore, there is an increasing demand from young and active patients to receive a
new joint which allows a normal or nearly normal life style. With this in mind, we began, in 1993, to develop a new femoral
implant. The purpose of this ultra-short stem was a physiologic strain distribution on the proximal femur with a proximal
load transfer from the implant to the femoral bone. Main features were an almost complete absence of the diaphyseal portion
of the stem, a well defined lateral flare with load transfer on the lateral column of the femur, and a very high femoral neck
cut. These innovations resulted in a conservative implant on both the bone stock and the soft tissues. This implant, in the
first years, was recommended only for young and active patients. Over the last thirteen years, this project has undergone
several modifications but the basic principles of the implant have remained the same. In the present review, we present the
rationale, the surgical technique and the clinical and experimental results so far obtained with this implant. 相似文献
92.
Sugar and tooth decays are bound closely. The mechanisms of destruction of the tooth from the glycolyse are known. The role played by the food in the development of the caries is unique. Foods sweetened of all ways, rich in sucrose are responsible of the intervening of the carious lesions. The transformation of the fermentable sugars in lactic with the absence of hygiene and the action conjugated of the bacteria leads to tooth decays in temporary and permanent denture that evolve very quickly in the absence of treatment. Reasons for which the authors put in evidence in this survey, the influence of the food sweetened on the teeth at the children while showing the cases of caries and its complications due to the excessive consumption of fermentable hydrates of carbon. 相似文献
93.
Mani N Pavuluri Megan Marlow O'Connor Erin M Harral Melissa Moss John A Sweeney 《Neuropsychopharmacology》2006,60(9):951-956
BACKGROUND: Previous research has demonstrated that academic and neuropsychological functions are compromised in pediatric bipolar disorder (PBD). Investigation of the degree to which neuropsychological deficits might contribute to those academic problems is needed to aid in the recognition and intervention for school achievement difficulties in PBD. METHODS: A sample of 55 children and adolescents with PBD with and without attention-deficit/hyperactivity disorder (ADHD) (PBD group, n = 28; PBD+ADHD group, n = 27) were tested with a computerized neurocognitive battery and standardized neuropsychological tests. Age range of subjects was 7-17 years, with the mean age of 11.97 (3.18) years. Parents completed a structured questionnaire on school and academic functioning. RESULTS: Logistic regression analyses indicated that executive function, attention, working memory, and verbal memory scores were poorer in those with a history of reading/writing difficulties. A separate logistic regression analysis found that attentional dysfunction predicted math difficulties. These relationships between neuropsychological function and academic difficulties were not different in those with PBD+ADHD than in those with PBD alone. CONCLUSIONS: In PBD neuropsychological deficits in the areas of attention, working memory, and organization/problem solving skills all contribute to academic difficulties. Early identification and intervention for these difficulties might help prevent lower academic achievement in PBD. 相似文献
94.
95.
96.
Baha’ N. Noureddin Christiane E. Al-Haddad Ziad Bashshur Bared Safieh-Garabedian 《Albrecht von Graefes Archiv fur klinische und experimentelle Ophthalmologie》2006,244(6):750-752
Background The objective was to measure the plasma concentrations of thymulin and nerve growth factor (NGF) in a group of patients with primary open angle glaucoma (POAG) and compare them with age- and sex-matched normal controls.Methods Twenty-eight patients newly diagnosed with POAG who were not undergoing treatment were compared with the same number of age- and sex-matched healthy controls. Blood samples were drawn into heparinized tubes and plasma samples were collected for the determination of the concentrations of thymulin and NGF, using specific enzyme-linked immunosorbent assay (ELISA). The Student’s t test was used to perform the necessary statistical analysis of the results.Results Seventeen women and 11 men were enrolled in each of the two groups (study and control), with a mean age of 63.7 (SD 10.3) years in the former and 63.3 (SD 9.6) years in the latter. There was a highly significant (p<0.001) elevation in the thymulin levels in POAG patients compared with the control group. However, no significant difference was observed when comparing the plasma NGF levels.Conclusion This is the first report to measure plasma thymulin levels in glaucoma patients. The significant results point the possible role of this immunomodulator in the pathogenesis of primary open angle glaucoma. The potential role of NGF seems to be less likely. These findings warrant further investigation. 相似文献
97.
Flavia M. N. P. Aslanian Maria Teresa Q. Marques Haroldo J. Matos Luciane F. S. Pontes Luis Cristvo S. Porto Lucia M. S. Azevedo Absalom L. Filgueira 《Journal der Deutschen Dermatologischen Gesellschaft》2006,4(10):842-847
Background: Lichen sclerosus (LS) has been identified with increased frequency in families,often associated with HLA markers, mainly DQ7. A genetic co‐etiology seems likely in this setting. Moreover, there is an association of LS with autoimmune disorders, such as the presence of anti‐thyroid peroxidase autoantibodies (anti‐TPO), a hallmark of autoimmune thyroid diseases. Patients and Methods: In 3 families affected by LS, we verified their HLA markers, and identified previously undiagnosed cases of LS and autoimmune disorders. 30 individuals were examined with history, skin biopsy, HLA class I and II typing by PCR‐SSP, and measurement of anti‐TPO, free thyroxine and thyroidstimulating hormones (TSH) levels. Results: There were 8 cases of LS, 50 % of them anti‐TPO+. Autoimmune disorders were found in 40 % (total) and in 87.5 % of those affected. Most common HLA markers were B*15, B*57, CW*03, CW*07, CW*18, DRB1*04, DRB1*07, DRB4*. The three latter have been previously associated with LS. Conclusion: New cases of LS and autoimmune disorders can be detected in first degree relatives of patients with LS. The presence of anti‐TPO antibodies strongly suggests autoimmune thyroiditis. There is intra‐familial association between the haplotype HLA‐B*15 ‐DRB1*04 ‐DRB4* and anti‐TPO,emphasizing their link with thyroiditis. New familial approaches might help to make clear the pathogenesis of LS and its association with autoimmune diseases. 相似文献
98.
Carmine Nieuwstraten N Renee Labiris Anne Holbrook 《Revue canadienne de psychiatrie》2006,51(5):300-316
OBJECTIVE: Antidepressants are commonly used drugs with potential for numerous drug interactions. This study aims to systematically review the literature on drug interactions with antidepressants. METHODS: We searched MEDLINE (1966 to November 2003) and EMBASE (1980 to 2003), using the heading drug interactions combined with individual antidepressant names. We restricted searches to English-language articles and human studies. We screened drug interaction texts and review articles for relevant studies. We included articles reporting original human data on drug interactions with antidepressants commonly used in North America. Articles were independently evaluated by 2 reviewers on clinical effect, clinical significance, and quality of evidence. Discrepancies were resolved by consensus. RESULTS: There were 904 eligible interactions, involving 9509 patients, for a total of 598 summary interactions. Of these, 439 (73%) demonstrated an interaction, 148 (25%) had no effect, and 11 (2%) had conflicting evidence. For 510 interactions (85%), the quality of evidence was poor. It was fair for 67 (11%) interactions and good for 10 (2%) interactions. There were no interactions with excellent quality of evidence. There were 145 (24%) interactions of major clinical significance. These were predominantly hypertensive emergencies and serotonin syndrome. Most interacting drugs had central nervous system (CNS) activity. As expected, monoamine oxidase inhibitors (MAOIs) appear to be the most problematic family in terms of potential for serious drug interactions. CONCLUSIONS: Drug interactions with antidepressants are an important cause for concern, but this concern is based primarily on poor evidence. We recommend caution when combining antidepressants with other CNS drugs, particularly when coadministering MAOIs with other substances. 相似文献
99.
N Simelela 《International journal of gynaecology and obstetrics》2006,94(3):292-300
Preventing unintended pregnancies through access to modern family planning could avert 20-35% of maternal deaths, saving the lives of more than 100,000 women each year. Obstacles to wider access still exist, but they may be overcome by overt policy commitment to reproductive health services, partnership between stakeholders, community involvement and quality programs. 相似文献
100.