全文获取类型
收费全文 | 19499篇 |
免费 | 1263篇 |
国内免费 | 68篇 |
专业分类
耳鼻咽喉 | 175篇 |
儿科学 | 439篇 |
妇产科学 | 472篇 |
基础医学 | 2947篇 |
口腔科学 | 816篇 |
临床医学 | 2237篇 |
内科学 | 4008篇 |
皮肤病学 | 353篇 |
神经病学 | 1819篇 |
特种医学 | 560篇 |
外科学 | 1954篇 |
综合类 | 128篇 |
一般理论 | 9篇 |
预防医学 | 1877篇 |
眼科学 | 289篇 |
药学 | 1480篇 |
中国医学 | 108篇 |
肿瘤学 | 1159篇 |
出版年
2023年 | 186篇 |
2022年 | 249篇 |
2021年 | 497篇 |
2020年 | 309篇 |
2019年 | 521篇 |
2018年 | 708篇 |
2017年 | 501篇 |
2016年 | 547篇 |
2015年 | 699篇 |
2014年 | 767篇 |
2013年 | 1094篇 |
2012年 | 1637篇 |
2011年 | 1682篇 |
2010年 | 785篇 |
2009年 | 656篇 |
2008年 | 1234篇 |
2007年 | 1223篇 |
2006年 | 1171篇 |
2005年 | 1089篇 |
2004年 | 1055篇 |
2003年 | 956篇 |
2002年 | 878篇 |
2001年 | 184篇 |
2000年 | 159篇 |
1999年 | 142篇 |
1998年 | 115篇 |
1997年 | 89篇 |
1996年 | 105篇 |
1995年 | 71篇 |
1994年 | 51篇 |
1993年 | 49篇 |
1992年 | 78篇 |
1991年 | 83篇 |
1990年 | 83篇 |
1989年 | 77篇 |
1988年 | 69篇 |
1987年 | 74篇 |
1986年 | 86篇 |
1985年 | 72篇 |
1984年 | 79篇 |
1983年 | 71篇 |
1982年 | 59篇 |
1981年 | 56篇 |
1980年 | 59篇 |
1979年 | 37篇 |
1978年 | 34篇 |
1976年 | 32篇 |
1974年 | 34篇 |
1971年 | 34篇 |
1970年 | 31篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Larry E. Davis Mario Kornfeld Herbert S. Mooney Kurt J. Fiedler Kathleen Y. Haaland William W. Orrison Elsa Cernichiari Thomas W. Clarkson 《Annals of neurology》1994,35(6):680-688
For 3 months in 1969 a family in the United States that included a pregnant mother consumed pork containing methylmercury. Children, aged 20, 13, and 8 years and a neonate, developed severe neurological signs. Twenty-two years later, the 2 oldest had cortical blindness or constricted visual fields, diminished hand proprioception, choreoathetosis, and atentional deficits. Magnetic resonance images showed tissue loss in the calcarine and parietal cortices and cerebellar folia. The youngest had quadriplegia, blindness, and severe mental retradation until their deaths. The brain of the 8-year-old who died at age 30 showed cortical atrophy, neuronal loss, and gliosis, most pronounced in the paracentral and parietooccipital regions. The total mercury level in formalin-fixed, left occipital cortex was 1,974 ng/gm as measured by atomic absorption. Regional brain mercury levels correlated with extent of brain damage. A control patient had 38.5 ng of mercury/gm in the occipital cortex. Systemic organs in the patient and a control subject had comparable mercury levels. In mercury-intoxicated rats, we found that only 5 to 10% of total brain mercury was lost by formalin fixation. Brain inorganic mercury in the patient ranged from 82 to 100%. Since inorganic mercury crosses the blood-brain barrier poorly, biotransformation of methyl to inorganic mercury may have occurred after methylmercury crossed the blood-brain barrier, accounting for its persistence in brain and causing part of the brain damage. 相似文献
32.
Lower limb ulcers present a common clinical problem and are at risk of malignant change. A Marjolin's ulcer has traditionally been regarded as malignant change in a long standing ulcer and/or scar tissue.We report a case of Marjolin's degeneration that developed in an ulcer only 18 months following the initial injury. Such a short latent period has not been reported for over 70 years. This report highlights the possibility of early Marjolin's change and we propose a ranked diagnostic screen to aid in early identification of possible malignant change, based on the current published evidence. 相似文献
33.
34.
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
35.
36.
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
37.
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
38.
39.
Thomas B Clarkson 《European heart journal》2006,27(6):635-637
Tibolone is widely used in many countries (though not in theUSA) for the treatment of post-menopausal symptoms and to inhibitpost-menopausal bone loss. Tibolone's popularity likely reflectsthe observation that it equals traditional hormone therapy inthe relief of hot flushes, vaginal dryness, and the preventionof bone loss and, in addition, appears to increase libido. Thepost-menopausal benefits of tibolone relate to the uniquenessof the metabolism of the parent molecule. In human and non-humanprimates, tibolone is converted to three metabolites. Two areweak estrogen agonists (the 3-alpha and 3-beta hydroxy metabolites).The third metabolite, the delta-4 isomer, is a molecule thatbinds both to the progesterone receptor and to the androgenreceptor with progestogenic and androgenic effects. Although tibolone has numerous benefits for post-menopausalwomen, it markedly lowers plasma concentrations of the HDL withconsistent reductions of 相似文献
40.
This brief review focuses on the time course of changes in muscle function and other correlates of muscle damage following maximal effort eccentric actions of the forearm flexor muscles. Data on 109 subjects are presented to describe an accurate time course of these changes and attempt to establish relationships among the measures. Peak soreness is experienced 2-3 d postexercise while peak swelling occurs 5 d postexercise. Maximal strength and the ability to fully flex the arm show the greatest decrements immediately after exercise with a linear restoration of these functions over the next 10 d. Blood creatine kinase (CK) levels increase precipitously at 2 d after exercise which is also the time when spontaneous muscle shortening is most pronounced. Whether the similarity in the time courses of some of these responses implies that they are caused by similar factors remains to be determined. Performance of one bout of eccentric exercise produces an adaptation such that the muscle is more resistant to damage from a subsequent bout of exercise. The length of the adaptation differs among the measures such that when the exercise regimens are separated by 6 wk, all measures show a reduction in response on the second, compared with the first, bout. After 10 wk, only CK and muscle shortening show a reduction in response. After 6 months only the CK response is reduced. A combination of cellular factors and neurological factors may be involved in the adaptation process. 相似文献