全文获取类型
收费全文 | 60561篇 |
免费 | 4387篇 |
国内免费 | 135篇 |
专业分类
耳鼻咽喉 | 675篇 |
儿科学 | 2166篇 |
妇产科学 | 1460篇 |
基础医学 | 7531篇 |
口腔科学 | 840篇 |
临床医学 | 9026篇 |
内科学 | 10963篇 |
皮肤病学 | 688篇 |
神经病学 | 5472篇 |
特种医学 | 1666篇 |
外国民族医学 | 2篇 |
外科学 | 6384篇 |
综合类 | 883篇 |
一般理论 | 60篇 |
预防医学 | 7750篇 |
眼科学 | 1255篇 |
药学 | 3843篇 |
中国医学 | 63篇 |
肿瘤学 | 4356篇 |
出版年
2023年 | 431篇 |
2022年 | 586篇 |
2021年 | 1220篇 |
2020年 | 811篇 |
2019年 | 1312篇 |
2018年 | 1531篇 |
2017年 | 1133篇 |
2016年 | 1199篇 |
2015年 | 1366篇 |
2014年 | 1893篇 |
2013年 | 2883篇 |
2012年 | 4195篇 |
2011年 | 4411篇 |
2010年 | 2375篇 |
2009年 | 2200篇 |
2008年 | 3886篇 |
2007年 | 3951篇 |
2006年 | 3841篇 |
2005年 | 3731篇 |
2004年 | 3528篇 |
2003年 | 3184篇 |
2002年 | 3065篇 |
2001年 | 774篇 |
2000年 | 771篇 |
1999年 | 775篇 |
1998年 | 670篇 |
1997年 | 562篇 |
1996年 | 447篇 |
1995年 | 415篇 |
1994年 | 405篇 |
1993年 | 400篇 |
1992年 | 529篇 |
1991年 | 531篇 |
1990年 | 482篇 |
1989年 | 479篇 |
1988年 | 418篇 |
1987年 | 397篇 |
1986年 | 408篇 |
1985年 | 392篇 |
1984年 | 339篇 |
1983年 | 268篇 |
1982年 | 243篇 |
1981年 | 232篇 |
1980年 | 205篇 |
1979年 | 222篇 |
1978年 | 173篇 |
1977年 | 178篇 |
1975年 | 138篇 |
1974年 | 150篇 |
1973年 | 145篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
Jill Macleod Clark PhD BSc RGN Jill Maben MSc BA RGN Karen Jones BA RHV RGN 《Journal of advanced nursing》1997,26(1):161-168
This is the first of two papers which address aspects of the findings of a large scale study commissioned by the English National Board which set out to examine the impact of Project 2000 on perceptions of the philosophy and practice of nursing. The findings presented here suggest that there have been fundamental shifts in perceptions of the nature and discipline of nursing. Students and diplomates of the course perceive themselves as knowledgeable doers, with their practice well grounded in theory and research. They value the interpersonal skills teaching and place the patient firmly at the centre of care delivery, viewing the patient holistically and being prepared to be fierce patient advocates where necessary. It is difficult to determine the extent to which these shifts can be attributed to the Project 2000 course, although the Project 2000 approach to education appears to be an important factor. 相似文献
72.
Jonathan Cook Neil Prose Mitchell Heflin 《Dermatologic surgery》2003,29(9):1994; author reply 1994-1994; author reply 1995
73.
74.
75.
Lorien Abroms Cynthia M Jorgensen Brian G Southwell Alan C Geller Karen M Emmons 《Health education & behavior》2003,30(1):29-43
This study employs focus group methodology to explore gender differences in sunscreen use. Guided by the theory of reasoned action, males and females were found to differ on each of the following constructs: behavior, behavioral beliefs, and normative beliefs. Males and females differed in their sunscreen use, with females adopting a more preventive style of sunscreen use and males a more reactive style. Males and females differed in their salient beliefs that motivated their sunscreen use, many of which were related to traditional American gender roles. In addition, although males and females were aware of both positive and negative sources of normative beliefs regarding sunscreen use, females received more encouragement from their mothers and peers than males. Findings are discussed in terms of their implications for the design of future interventions. 相似文献
76.
Multiplex PCR analysis of in vivo-arising deletion mutations in the hprt gene of human T-lymphocytes
James C. Fuscoe Lisa J. Zimmerman Karen Harrington-Brock Martha M. Moore 《Environmental and molecular mutagenesis》1994,23(2):89-95
A multiplex polymerase chain reaction (PCR) procedure was adapted for the rapid and efficient evaluation of deletions of the hypoxanthine guanine phosphoribosyltransferase (hprt) gene in human T-lymphocytes. The hprt clonal assay was used to isolate in vivo-arising hprt-deficient T-cells from six healthy males. Mutant frequencies ranged from 9-27 × 10?6. Simple crude cellular extracts from 223 mutants were analyzed for hprt gene deletion. Sixteen (7.2%) were found to be due to total gene deletion and 22 (9.9%) were due to partial gene deletion. The relatively high frequency of total gene deletions was caused by replicate isolates of a single mutational event as shown by single-strand conformation polymorphism (SSCP) analysis of rearranged T-cell receptor (TCR)-γ genes. Eighteen of the 22 partial hprt gene deletion mutants were determined to be of independent origin based on a unique hprt mutation or SSCP-TCR-γ pattern. One-half (9/18) of the partial deletion mutants involved all or part of exon 4 alone, suggesting that this region of the hprt gene is prone to deletion. The small deletions effecting exon 1 (1 mutant), exon 2 (2 mutants), and exon 4 (6 mutants) would not have been detected by conventional Southern blot analysis and may represent a new, previously unrecognized class of mutations. The ready isolation of such intragenic deletions will allow the characterization of breakpoint junctions and may provide insights into the important processes of DNA breakage and rejoining. © 1994 Wiley-Liss, Inc. 相似文献
77.
78.
This study examined the potential beneficial effects of the addition of a second-generation sulfonylurea to insulin therapy for poorly controlled type II diabetes. A randomized, double-blind, crossover experimental design was utilized in 16 type II diabetic patients for a period of eight months. Treatment with glyburide, 20 mg/d (plus insulin), compared with placebo (plus insulin) resulted in a significant reduction in mean basal glucose (232 +/- 12 vs 262 +/- 11 mg/dL [12.8 vs 14.4 mmol/L]) and hemoglobin A1C (10.2% +/- 0.5% vs 10.9% +/- 03%) concentrations. Concomitant with this change, basal C-peptide and free insulin values increased with glyburide therapy, but this pharmacological agent did not alter the ability of the patient's erythrocytes to bind insulin. We conclude that in type II diabetic subjects receiving more than 28 units of insulin per day, the addition of glyburide results in a marginal, but statistically significant improvement in basal glucose concentration, but not in glucose tolerance as assessed by integrated glucose concentration. Whether this small improvement in glycemia is worth the additional cost of sulfonylureas or the risk of drug side effects is not known. 相似文献
79.
A study was undertaken to determine the adequacy of vascularised jejunum to provide stable mucosal cover over a non-biological mandibular substitute. Employing a canine model, composite intra-oral bone-mucosal defects were created and reconstructed with a metal plate covered by a microvascular jejunal patch. These were followed for six months and were assessed clinically, histologically and radiologically. Rapid mucosal healing occurred in all cases. The autografts conformed to the contour of the prosthesis and adequate tongue mobility was preserved. All mandibles remained stable throughout the follow-up period. Histologically, short villi covered the jejunal grafts to three months whilst at six months both normal and abnormal jejunal mucosal morphology was evident. 相似文献
80.
B J Zeeman G M Mitchell A E Olazabal P A Collopy W A Morrison B M O'Brien 《British journal of plastic surgery》1988,41(5):509-514
The significance of resection length on patency rate, and the histopathology, of microsurgically repaired avulsed blood vessels was examined at 3 weeks in two groups of experimentally avulsed rabbit femoral arteries repaired by different surgeons and in a single series of avulsed and repaired veins. All veins were patent 3 weeks after avulsion and microsurgical repair. Histopathology indicated that the vast majority of lesions in veins were removed at resection. Surgeon A achieved 75% patent arteries and Surgeon B achieved 100% arterial patency (resecting 3.7 mm more on average than Surgeon A). Histopathology revealed numerous luminal circumferential lesions remained in the avulsed artery wall following resection. These lesions were sites of smooth muscle cell proliferation and neointima formation. Although similar arterial damage occurs in human avulsion, considerably lower patency rates are achieved for human arterial avulsion repair than were reported in this experimental study. Factors in addition to vessel wall damage must therefore be involved in thrombosis and occlusion of repaired avulsed arteries. Such factors might be lengthy ischaemia time and severe spasm. 相似文献