全文获取类型
收费全文 | 18934篇 |
免费 | 1245篇 |
国内免费 | 67篇 |
专业分类
耳鼻咽喉 | 208篇 |
儿科学 | 428篇 |
妇产科学 | 467篇 |
基础医学 | 2772篇 |
口腔科学 | 707篇 |
临床医学 | 2230篇 |
内科学 | 3979篇 |
皮肤病学 | 360篇 |
神经病学 | 1824篇 |
特种医学 | 503篇 |
外科学 | 1914篇 |
综合类 | 110篇 |
一般理论 | 9篇 |
预防医学 | 1831篇 |
眼科学 | 264篇 |
药学 | 1452篇 |
中国医学 | 105篇 |
肿瘤学 | 1083篇 |
出版年
2023年 | 169篇 |
2022年 | 213篇 |
2021年 | 501篇 |
2020年 | 314篇 |
2019年 | 528篇 |
2018年 | 722篇 |
2017年 | 508篇 |
2016年 | 555篇 |
2015年 | 710篇 |
2014年 | 782篇 |
2013年 | 1116篇 |
2012年 | 1656篇 |
2011年 | 1687篇 |
2010年 | 802篇 |
2009年 | 668篇 |
2008年 | 1253篇 |
2007年 | 1246篇 |
2006年 | 1182篇 |
2005年 | 1124篇 |
2004年 | 1065篇 |
2003年 | 974篇 |
2002年 | 881篇 |
2001年 | 140篇 |
2000年 | 127篇 |
1999年 | 109篇 |
1998年 | 99篇 |
1997年 | 87篇 |
1996年 | 103篇 |
1995年 | 62篇 |
1994年 | 43篇 |
1993年 | 46篇 |
1992年 | 63篇 |
1991年 | 53篇 |
1990年 | 54篇 |
1989年 | 38篇 |
1988年 | 35篇 |
1987年 | 41篇 |
1986年 | 47篇 |
1985年 | 38篇 |
1984年 | 52篇 |
1983年 | 31篇 |
1982年 | 37篇 |
1981年 | 44篇 |
1980年 | 30篇 |
1979年 | 22篇 |
1978年 | 14篇 |
1977年 | 13篇 |
1975年 | 15篇 |
1974年 | 13篇 |
1970年 | 13篇 |
排序方式: 共有10000条查询结果,搜索用时 265 毫秒
41.
Jorge Polónia Jo?o Maldonado Rui Ramos Susana Bertoquini Mary Duro Cristina Almeida Jo?o Ferreira Loide Barbosa José Alberto Silva Luís Martins 《Revista portuguesa de cardiologia》2006,25(9):801-817
BACKGROUND: Portugal has one of the highest mortality rates from stroke, a high prevalence of hypertension and probably a high salt intake level. AIM: To evaluate Portuguese salt intake levels and their relationship to blood pressure and arterial stiffness in a sample of four different adult populations living in northern Portugal. METHODS: A cross-sectional study evaluating 24-hour urinary excretion of sodium (24 h UNa+), potassium and creatinine, blood pressure (BP), and pulse wave velocity (PWV) as an index of aortic stiffness in adult populations of sustained hypertensives (HT), relatives of patients with previous stroke (Fam), university students (US) and factory workers (FW), in the context of their usual dietary habits. RESULTS: We evaluated a total of 426 subjects, mean age 50 +/- 22 years, 56% female, BMI 27.9+/-5.1, BP 159/92 mmHg, PWV 10.4+/-2.2 m/s, who showed mean 24h UNa+ of 202 +/- 64 mmol/d, corresponding to a daily salt intake of 12.3 g (ranging from 5.2 to 24.8). The four groups were: HT: n = 245, 49 +/- 18 years, 92% of those selected, 69% treated, BP 163/94 mmHg, PWV 11.9 m/s, 24 h UNa+ 212 mmol/d, i.e. 12.4 g/d of salt); Fam: n = 38, 64 +/- 20 years, 57 % of those selected, BP 144/88 mmHg, PWV 10.5 m/s, 24 h UNa+ 194 mmol/d, i.e. 11.1 g/d of salt; US: n = 82, 22 +/- 3 years, 57% of those selected, BP 124/77 mmHg, PWV 8.7 m/s, 24h UNa+ 199 mmol/d, i.e. 11.3 g/d of salt; FW: n = 61, 39 9 years, 47% of those selected, BP 129/79 mmHg, PWV 9.5 m/s, 24 h UNa+ 221 mmol/d, i.e. 12.9 g/d of salt. The ratio of urinary sodium/potassium excretion (1.9 (0.4) was significantly higher in HT than the other three groups. In the 426 subjects, 24h UNa+ correlated significantly (p < 0.01) with systolic BP (r = 0.209) and with PWV (r=0.256) after adjustment for age and BP. Multivariate analysis showed that BP, age and 24h UNa+ correlated independently with PWV taken as a dependent variable. CONCLUSIONS: Four different Portuguese populations showed similarly high mean daily salt intake levels, almost double those recommended by the WHO. Overall, high urinary sodium excretion correlated consistently with high BP levels and appeared to be an independent determining factor of arterial stiffness. These findings suggest that Portugal in general has a high salt intake diet, and urgent measures are required to restrict salt consumption in order to prevent and treat hypertensive disease and to reduce overall cardiovascular risk and events. 相似文献
42.
As we rush around attending to the essentials of our lives (family, friends, clients, employers), what is left? Nursing Forum invites readers to engage in thoughts and activities that may awaken an untouched place. We hope these writings will kindle your personal involvement in something that was previously avoided–because of bias, fear, or uneasiness–in order to stretch your mind and spirit. 相似文献
43.
Dianne P. Goeman Robyn E. O'Hehir Christine Jenkins Simon L. Scharf Jo A. Douglass 《The clinical respiratory journal》2007,1(2):99-105
Introduction: Asthma mortality has declined overall because of a range of public health initiatives. In western countries, the majority of asthma deaths now occur in people over the age of 50. The reasons for the poorer response of older age groups to public health asthma initiatives are not known. Objectives: We undertook a study to investigate the disease perspectives of older people with asthma and barriers which may exist and prevent optimal asthma care. Methods: Fifty‐five participants (16 male and 39 female) aged over 50 from an inner city, suburban area and a rural region were recruited. Lung function was measured, and questionnaire data on asthma symptoms, knowledge and control, medication use and respiratory health were collected. Participants were also interviewed in‐depth, and the quantitative and qualitative data were triangulated. Results: Participants with a duration of asthma for >30 years reported significantly fewer symptoms and better quality of life irrespective of asthma severity, indicating less appreciation of symptoms in those with a long asthma duration. Interviews revealed this was related to previous asthma management strategies when treatment options were limited. Participants with a recent diagnosis sought understanding of asthma and the reason for their illness. Initiatives to improve asthma care in older people need to reflect these findings. Conclusions: Self‐management strategies for older people need to be tailored according to the time of disease onset and the duration of disease. Please cite this paper as: Goeman DP, O’Hehir RE, Jenkins C, Scharf SL and Douglass JA. ‘You have to learn to live with it’: a qualitative and quantitative study of older people with asthma. The Clinical Respiratory Journal 2007; 1:99–105. 相似文献
44.
45.
46.
Gliomatosis peritonei, the miliary implants of mature glial tissues on the peritoneum or omentum, is a rare complication of solid ovarian teratoma. Our case is reported and 38 previously reported cases are reviewed. The grade of the primary tumors varied from grade 0 to grade 3. Only five cases were composed entirely of mature tissues. Five of the 39 patients died. Despite of varied therapy, the rest of the patients were alive from 3 months to 38 years later. Inspite of intraperitoneal implants, the prognosis in patients with these tumors is good, irrespective of the mode of therapy. On the basis of this study, we recommended a conservative therapy for the primary tumor and therapy for the implants is not required. 相似文献
47.
48.
Scott A. Rodeo Jo A. Hannafin James Tom Russell F. Warren Thomas L. Wickiewicz 《Journal of orthopaedic research》1997,15(3):427-436
The purpose of this study was to test the hypothesis that specific cytokines are involved in the initiation and evolution of the fibrotic process in adhesive capsulitis of the shoulder. After approval from the Institutional Review Board, biopsies of shoulder capsule and synovium were collected during shoulder arthroscopy from 19 patients with adhesive capsulitis, 14 patients with nonspecific synovitis and no fibrosis or clinical evidence of adhesive capsulitis, and seven patients undergoing surgery for another pathology who had a normal capsule and synovium. Immunohistochemical localization with monoclonal antibodies to transforming growth factor-β and its receptor, platelet-derived growth factor and its receptor, basic fibroblast growth factor, interleukin-1β, tumor necrosis factor-α, and hepatocyte growth factor was performed using standard immunoperoxidase techniques. The frequency of cytokine staining was correlated with the clinical diagnosis Synovial cells, fibroblasts, T-cells, and B-cells were identified with specific antibodies, and newly synthesized matrix was examined for type-I and type-III collagen by immunohistochemical staining. The predominant cell types present were synovial cells and fibroblasts. Staining for type-III collagen in adhesive capsulitis tissues indicated new deposition of collagen in the capsule. There was staining for transforming growth factor-β and its receptor, platelet-derived growth factor and its receptor, interleukin-1β, and tumor necrosis factor-α in adhesive capsulitis and nonspecific synovitis tissues, compared with minimal staining in normal capsule. Staining was more frequent in snovial cells than in capsular cells. The frequency of cell and matrix staining for transforming growth factor-β, platelet-derived growth factor, and hepatocyte growth factor was greater in adhesive capsulitis tissues than in those from patients with nonspecific synovitis. No difference in the frequency of staining between primary (idiopathic) and secondary adhesive capsulitis was found. The results of this study indicate that adhesive/capsulitis involves both synovial hyperplasia and capsular fibrosis. Cytokines such as transforming growth factor-β and platelet-derived growth factor may be involved in the inflammatory and fibrotic processes in adhesive capsulitis. Matrix-bound transforming growth factor-β may act as a persistent stimulus, resulting in capsular fibrosis. Understanding the basic pathophysiology of adhesive capsulitis is an important step in the development of clinically useful antifibrotic agents that may serve as novel treatments for patients with this condition. 相似文献
49.
Combined percutaneous antegrade and cystoscopic retrograde approach in the treatment of distal ureteric fistulae 总被引:1,自引:1,他引:0
Thierry de Baere Alain Roche Christine Lagrange Alban Denys Bernard Court Joël Isapoff Paris Pappas 《Cardiovascular and interventional radiology》1995,18(6):349-352
Purpose To determine the efficacy of a cystoscopic approach, as definitive treatment of ureteral fistulae, after failure of antegrade ureteral stent insertion.Methods Of 43 ureter fistulae encountered over 4 years, 10 postoperative and/or postradiotherapy fistulae could not be stented via an antegrade approach alone. A cystoscopic approach was used, with the antegrade approach available as back-up, if necessary.Results In two patients the ureteral orifice could not be visualized cystoscopically, thus precluding the retrograde approach. In the eight remaining patients, the retrograde approach alone never allowed successful stenting. In six patients, combined antegrade and retrograde approaches permitted stent insertions. In three of those six patients, a complex catheterization procedure was necessary. In two patients the combined approach failed altogether. Therefore, 6 of 10 patients underwent a successful stenting procedure with the combined approach; all ultimately closed the fistula.Conclusion Antegrade stent insertion remains the treatment of choice for ureteral leaks. If the antegrade approach fails, the retrograde approach alone is not likely to be successful. Instead, a combination of both approaches often does succeed. 相似文献
50.