全文获取类型
收费全文 | 2374篇 |
免费 | 162篇 |
国内免费 | 23篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 72篇 |
妇产科学 | 50篇 |
基础医学 | 235篇 |
口腔科学 | 26篇 |
临床医学 | 248篇 |
内科学 | 606篇 |
皮肤病学 | 233篇 |
神经病学 | 113篇 |
特种医学 | 179篇 |
外科学 | 261篇 |
综合类 | 29篇 |
一般理论 | 1篇 |
预防医学 | 249篇 |
眼科学 | 55篇 |
药学 | 120篇 |
中国医学 | 2篇 |
肿瘤学 | 74篇 |
出版年
2021年 | 29篇 |
2019年 | 21篇 |
2018年 | 31篇 |
2017年 | 31篇 |
2016年 | 45篇 |
2015年 | 56篇 |
2014年 | 72篇 |
2013年 | 112篇 |
2012年 | 52篇 |
2011年 | 75篇 |
2010年 | 66篇 |
2009年 | 75篇 |
2008年 | 57篇 |
2007年 | 70篇 |
2006年 | 70篇 |
2005年 | 54篇 |
2004年 | 56篇 |
2003年 | 35篇 |
2002年 | 44篇 |
2001年 | 35篇 |
2000年 | 63篇 |
1999年 | 67篇 |
1998年 | 78篇 |
1997年 | 64篇 |
1996年 | 66篇 |
1995年 | 65篇 |
1994年 | 61篇 |
1993年 | 43篇 |
1992年 | 92篇 |
1991年 | 37篇 |
1990年 | 62篇 |
1989年 | 64篇 |
1988年 | 79篇 |
1987年 | 67篇 |
1986年 | 51篇 |
1985年 | 41篇 |
1984年 | 56篇 |
1983年 | 32篇 |
1982年 | 22篇 |
1981年 | 25篇 |
1980年 | 20篇 |
1979年 | 14篇 |
1978年 | 19篇 |
1976年 | 22篇 |
1973年 | 16篇 |
1972年 | 13篇 |
1971年 | 14篇 |
1970年 | 16篇 |
1966年 | 16篇 |
1964年 | 14篇 |
排序方式: 共有2559条查询结果,搜索用时 15 毫秒
1.
D Monnier† C Vidal‡ L Martin§ A Danzon¶ F Pelletier† E Puzenat† MP Algros†† D Blanc† R Laurent† PH Humbert† F Aubin† 《Journal of the European Academy of Dermatology and Venereology》2006,20(10):1237-1242
BACKGROUND: Dermatofibrosarcoma protuberans (DFSP) is a rare malignant tumour of the skin, with an estimated incidence of 0.8 to five cases per 1 million people per year. OBJECTIVE: To study epidemiological, immunohistochemical and clinical features, delay in diagnosis, type of treatment and outcome of DFSP from 1982 to 2002. METHODS: Using data from the population-based cancer registry, 66 patients with pathologically proved DFSP were included (fibrosarcomatous DFSP were excluded). Each patient lived in one of the four departments of Franche-Comté (overall population of 1 million people) at the time of diagnosis. The main data sources came from public and private pathology laboratories and medical records. The rules of the International Agency for Research on Cancer were applied. RESULTS: The estimated incidence of DFSP in Franche-Comté was about three new cases per 1 million people per year. Male patients were affected 1.2 times as often as female patients were. The trunk (45%) followed by the proximal extremities (38%) were the most frequent locations. DFSP occurred mainly in young adults between 20 and 39 years of age. Mean age at diagnosis was 43 years, and the mean delay in diagnosis was 10.08 years. Our 66 patients initially underwent a radical local excision. Among them, 27% experienced one or more local recurrences during 9.6 years of follow-up. There was one regional lymph node recurrence without visceral metastases. These recurrences were significantly related to the initial peripheral resection margins. We observed a local recurrence rate of 47% for margins less than 3 cm, vs. only 7% for margins ranging from 3 to 5 cm [P=0.004; OR=0.229 (95%, CI=0.103-0.510)]. The mean time to a first local recurrence was 2.65 years. Nevertheless, there was no death due to the DFSP course at the end of the follow-up, and the final outcome was favourable. CONCLUSION: Our study emphasizes the importance of wide local excision with margins of at least 3 cm in order to prevent local recurrence. However, the recent development of inhibitors of signal transduction by the PDGFB pathway should soon modify the surgical strategy, which is often too mutilating. 相似文献
2.
3.
4.
L. TIMMER-DE MIK M.D. D.M. BROEKHUIJSEN-VAN HENTEN M.D. † J.M. OLDHOFF M.D. PH.D. D.B. DE GEER M.D. ‡ V. SIGURDSSON M.D. PH.D. S.G.M.A. PASMANS M.D. PH.D. 《Pediatric dermatology》2009,26(3):358-360
Abstract: In Sweet's syndrome, the essential features are the characteristic morphology of the lesions, their histologic appearance, the dramatic response to corticosteroids and the absence of scarring. We report an 8-month-old infant in whom Sweet's syndrome was diagnosed and who developed acquired cutis laxa in the skin lesions. 相似文献
5.
HUGH F. MOLLOY F.A.C.D. ERIC LAMONT-GREGORY M.SC. CHRIS IDZIKOWSKI PH.D. F.B.PS.S. TERENCE J. RYAN D.M. F.R.C.P. 《International journal of dermatology》1993,32(9):668-672
Background. Extensive questioning of patients with a wide variety of skin disorders led to the impression that nocturnal overheating was probably an important factor in the initiation and the perpetuation of many skin disorders. Methods. In order to test the hypothesis, 12 “clean-skinned” subjects (6M/6F) aged 18 to 45 years were monitored electronically every 30 seconds during an 8 hour sleep period (2300 to 0700 hours), sleeping under a standard 10 tog duvet. Results. All the subjects were too hot by 3 to 4°C. All showed changes in their EEG patterns with reduced REM sleep, increased awakenings, and all showed changes in their sleep stage patterns. In addition, they all showed evidence of increased sweating in the “heat-sink” area. Conclusions. The mechanisms where by such changes could be implicated in the precipitation and perpetuation of skin disease are discussed. “Lifestyle” modification as a very effective, noninvasive, therapeutic regime is recommended. Further research along these lines would probably be very valuable and instructive. 相似文献
6.
J Mantz J Marty Y Pansard D Henzel A Loiseau M Pocidalo J Langlois J M Desmonts 《The Journal of thoracic and cardiovascular surgery》1990,99(1):75-81
To evaluate whether the function of beta-adrenergic receptors, essential to the biologic activity of catecholamines, is altered during coronary artery bypass grafting, we measured, in 16 patients undergoing myocardial revascularization, the density and the affinity of lymphocyte beta-adrenergic receptors before anesthesia induction (control) and at the end of cardiopulmonary bypass. Variations in the density and affinity of beta-adrenergic receptors were determined in vitro. Repeated determinations of plasma epinephrine and norepinephrine concentrations were also performed. Overall, no significant modification was observed in mean density and affinity of beta-adrenergic receptors at the end of cardiopulmonary bypass when compared with control values. However, a significant decrease (p less than 0.05) in affinity for isoproterenol was found in the six patients who had high catecholamine levels during cardiopulmonary bypass. In contrast, no significant modification of beta-adrenoreceptor affinity for isoproterenol was observed in the 10 patients who did not have this degree of adrenergic activation. In addition, beta-adrenoreceptor affinity for isoproterenol was decreased in the three patients in whom intraaortic balloon pumping was mandatory after discontinuation of cardiopulmonary bypass. We suggest that this decreased affinity of lymphocyte beta-adrenergic receptors could be related, at least in part, to a sustained adrenergic activation occurring in some patients during cardiopulmonary bypass. 相似文献
7.
8.
Braffman BH; Coleman BG; Ramchandani P; Arger PH; Nodine CF; Dinsmore BJ; Louie A; Betsch SE 《Radiology》1994,190(3):797
9.
The long-term effects of angiotensin-II (A-II) and corticotropin (ACTH) on bovine adrenal fasciculata cells (BAC) were studied. Cells were pretreated for 3 days with either A-II or ACTH followed by an examination of the acute steroidogenic response to both hormones as well as the ability to convert several steroid precursors to cortisol and corticosterone. ACTH pretreatment caused a marked increase in cortisol output associated with a decrease in corticosterone secretion in response to both hormones leading to a 50-fold decrease in the corticosterone/cortisol ratio compared to control cells. After incubation with saturating concentrations (5 X 10(-5) M) of 22 R-hydroxycholesterol, pregnenolone or progesterone, ACTH-pretreated cells produced more cortisol than corticosterone whereas the contrary was observed in control cells. However, the conversion of 17 alpha-hydroxyprogesterone and 11-deoxycortisol to cortisol by ACTH-pretreated cells was lower than by control cells. Thus, the main effects of ACTH were a marked increase of 17 alpha-hydroxylase and a small but significant decrease of 21-hydroxylase and 11 beta-hydroxylase activities. A-II pretreatment produced, in a concentration-dependent manner, a down-regulation of its own receptors and homologous and heterologous steroidogenic desensitization. At maximal concentrations (10(-6) M) A-II reduced by 70% its own receptors while the steroidogenic response to A-II and ACTH was reduced by 95% and 75%, respectively. However, the coupling of A-II receptors to phosphoinositide pathway and to Ca2+ influx, as well as its potentiation effect on ACTH-induced cAMP production were similar in control and A-II pretreated cells. Moreover, the conversion of several steroid precursors to corticosterone was similar in control cells and A-II-pretreated cells, whereas the conversion to cortisol was reduced by approximately 30% due mainly to a decrease of 17 alpha-hydroxylase activity. Thus, the marked steroidogenic desensitization induced by A-II is most likely related to some alteration located beyond the activation of the two branches of the phosphoinositide pathway and before the first steps of steroidogenesis. 相似文献
10.