全文获取类型
收费全文 | 2178722篇 |
免费 | 168500篇 |
国内免费 | 5185篇 |
专业分类
耳鼻咽喉 | 28913篇 |
儿科学 | 73418篇 |
妇产科学 | 62058篇 |
基础医学 | 312846篇 |
口腔科学 | 60021篇 |
临床医学 | 197219篇 |
内科学 | 427622篇 |
皮肤病学 | 50425篇 |
神经病学 | 177272篇 |
特种医学 | 83026篇 |
外国民族医学 | 752篇 |
外科学 | 324549篇 |
综合类 | 51728篇 |
现状与发展 | 3篇 |
一般理论 | 819篇 |
预防医学 | 172509篇 |
眼科学 | 49920篇 |
药学 | 155062篇 |
4篇 | |
中国医学 | 4863篇 |
肿瘤学 | 119378篇 |
出版年
2019年 | 17089篇 |
2018年 | 24279篇 |
2017年 | 18661篇 |
2016年 | 21167篇 |
2015年 | 23716篇 |
2014年 | 33233篇 |
2013年 | 50123篇 |
2012年 | 67147篇 |
2011年 | 71367篇 |
2010年 | 42213篇 |
2009年 | 40139篇 |
2008年 | 66290篇 |
2007年 | 70197篇 |
2006年 | 71127篇 |
2005年 | 68683篇 |
2004年 | 66170篇 |
2003年 | 63266篇 |
2002年 | 61093篇 |
2001年 | 105588篇 |
2000年 | 108216篇 |
1999年 | 90158篇 |
1998年 | 25498篇 |
1997年 | 23017篇 |
1996年 | 23052篇 |
1995年 | 22042篇 |
1994年 | 20213篇 |
1993年 | 18919篇 |
1992年 | 69433篇 |
1991年 | 66942篇 |
1990年 | 64909篇 |
1989年 | 62164篇 |
1988年 | 56751篇 |
1987年 | 56276篇 |
1986年 | 52558篇 |
1985年 | 50360篇 |
1984年 | 38159篇 |
1983年 | 32198篇 |
1982年 | 19559篇 |
1981年 | 17461篇 |
1979年 | 34397篇 |
1978年 | 24479篇 |
1977年 | 20489篇 |
1976年 | 19332篇 |
1975年 | 20067篇 |
1974年 | 24328篇 |
1973年 | 23434篇 |
1972年 | 21734篇 |
1971年 | 19992篇 |
1970年 | 18887篇 |
1969年 | 17489篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
62.
JM Martín† L Calduch† C Monteagudo‡ I Molina† D Ramón† V Alonso† E Jordᆠ《Journal of the European Academy of Dermatology and Venereology》2006,20(4):428-431
Cutaneous plasmacytosis is a rare disorder characterized by a benign proliferation of mature plasma cells that appears as multiple dark-brown to purplish skin lesions, often associated with polyclonal hypergammaglobulinaemia. We present the case of a 55-year-old Caucasian man who suffered from a cutaneous plasmacytosis associated with two different carcinomas. Cutaneous plasmacytosis seems to be a reactive process because most cases reported are not associated with any apparent underlying disease. Nevertheless, because few reported cases were associated with malignancies, screening of additional neoplasms would be justified. 相似文献
63.
A 17-year-old man presented with signs of peritonitis. Laparotomy revealed gangrene of the stomach without obvious cause. The patient underwent total gastrectomy with esophago-jejunal anastomosis with formation of jejunal pouch. Bacterial culture of the peritoneal fluid grew Strept. pyogenes and E. coli. The patient was discharged on day 21 after a stormy postoperative course. 相似文献
64.
65.
Chukwuka C Okafor Hana Haleem-Smith Patrice Laqueriere Paul A Manner Rocky S Tuan 《Journal of orthopaedic research》2006,24(3):461-473
Continual loading and articulation cycles undergone by metallic (e.g., titanium) alloy arthroplasty prostheses lead to liberation of a large number of metallic debris particulates, which have long been implicated as a primary cause of periprosthetic osteolysis and postarthroplasty aseptic implant loosening. Long-term stability of total joint replacement prostheses relies on proper integration between implant biomaterial and osseous tissue, and factors that interfere with this integration are likely to cause osteolysis. Because multipotent mesenchymal stem cells (MSCs) located adjacent to the implant have an osteoprogenitor function and are critical contributors to osseous tissue integrity, when their functions or activities are compromised, osteolysis will most likely occur. To date, it is not certain or sufficiently confirmed whether MSCs endocytose titanium particles, and if so, whether particulate endocytosis has any effect on cellular responses to wear debris. This study seeks to clarify the phenomenon of titanium endocytosis by human MSCs (hMSCs), and investigates the influence of endocytosis on their activities. hMSCs incubated with commercially pure titanium particles exhibited internalized particles, as observed by scanning electron microscopy and confocal laser scanning microscopy, with time-dependent reduction in the number of extracellular particles. Particulate endocytosis was associated with reduced rates of cellular proliferation and cell-substrate adhesion, suppressed osteogenic differentiation, and increased rate of apoptosis. These cellular effects of exposure to titanium particles were reduced when endocytosis was inhibited by treatment with cytochalasin D, and no significant effect was seen when hMSCs were treated only with conditioned medium obtained from particulate-treated cells. These findings strongly suggest that the biological responses of hMSCs to wear debris are triggered primarily by the direct endocytosis of titanium particulates, and not mediated by secreted soluble factors. In this manner, therapeutical approaches that suppress particle endocytosis could reduce the bioreactivity of hMSCs to particulates, and enhance long-term orthopedic implant prognosis by minimizing wear-debris periprosthethic osteolysis. 相似文献
66.
67.
68.
R H Green C E Brightling S McKenna B Hargadon N Neale D Parker C Ruse I P Hall I D Pavord 《The European respiratory journal》2006,27(6):1144-1151
There is increasing evidence that the assessment of eosinophilic airway inflammation using induced sputum and measurement of airway hyperresponsiveness provides additional, clinically important information concerning asthma control. The aim of this study was to directly compare the effects of different treatments on these markers in patients with asthma and persistent symptoms, despite the use of low-dose inhaled corticosteroids. A double-blind four-way crossover study was performed, which compared a 1-month treatment with budesonide 400 mug b.i.d., additional formoterol, additional montelukast and placebo in 49 patients with uncontrolled asthma despite budesonide 100 mug b.i.d., with each treatment separated by a 4-week washout period. The change in sputum eosinophil count with formoterol (2.4 to 3.8% change, 0.6-fold reduction, 95% confidence interval (CI) 0.5-0.9) differed significantly from placebo (2.8 to 2.5% change, 1.1-fold reduction, 95% CI 0.7-1.6) and high-dose budesonide (2.7 to 1.6% change, 1.6-fold reduction, 95% CI 1.2-2.2). The effects of montelukast did not differ from placebo. The changes in methacholine airway responsiveness were small and did not differ between treatments. High-dose budesonide had the broadest range of beneficial effects on other outcomes, including symptom scores, morning peak expiratory flow and forced expiratory volume in one second. In conclusion, treatment given in addition to low-dose inhaled corticosteroids results in modest benefits. Formoterol and high-dose budesonide have contrasting effects on eosinophilic airway inflammation. 相似文献
69.
N B Pride 《The European respiratory journal》2006,27(1):240-1; author reply 241-2
70.
C T Gan G P McCann J T Marcus S A van Wolferen J W Twisk A Boonstra P E Postmus A Vonk-Noordegraaf 《The European respiratory journal》2006,28(6):1190-1194
The aim of the current study was to investigate whether alterations in N-terminal pro brain natriuretic peptide (NT-proBNP) reflect changes in right ventricular structure and function in pulmonary hypertension patients during treatment. The study consisted of 30 pulmonary hypertension patients; 15 newly diagnosed and 15 on long-term treatment. NT-proBNP, right heart catheterisation and cardiac magnetic resonance imaging measurements were performed, at baseline and follow-up. There were no significant differences between newly diagnosed patients and those on treatment at baseline or follow-up with respect to NT-proBNP, haemodynamics and right ventricular parameters. Relative changes in NT-proBNP during treatment were correlated to the relative changes in right ventricular end-diastolic volume index (r = 0.59), right ventricular mass index (r = 0.62) and right ventricular ejection fraction (r = -0.81). N-terminal pro brain natriuretic peptide measurements reflect changes in magnetic resonance imaging-measured right ventricular structure and function in pulmonary hypertension patients. An increase in N-terminal pro brain natriuretic peptide over time reflects right ventricular dilatation concomitant to hypertrophy and deterioration of systolic function. 相似文献