全文获取类型
收费全文 | 3703篇 |
免费 | 320篇 |
国内免费 | 37篇 |
专业分类
耳鼻咽喉 | 45篇 |
儿科学 | 253篇 |
妇产科学 | 80篇 |
基础医学 | 452篇 |
口腔科学 | 107篇 |
临床医学 | 412篇 |
内科学 | 639篇 |
皮肤病学 | 66篇 |
神经病学 | 264篇 |
特种医学 | 324篇 |
外科学 | 517篇 |
综合类 | 87篇 |
预防医学 | 302篇 |
眼科学 | 57篇 |
药学 | 231篇 |
中国医学 | 1篇 |
肿瘤学 | 223篇 |
出版年
2021年 | 37篇 |
2020年 | 30篇 |
2019年 | 55篇 |
2018年 | 61篇 |
2017年 | 51篇 |
2016年 | 50篇 |
2015年 | 51篇 |
2014年 | 66篇 |
2013年 | 111篇 |
2012年 | 160篇 |
2011年 | 135篇 |
2010年 | 117篇 |
2009年 | 123篇 |
2008年 | 141篇 |
2007年 | 122篇 |
2006年 | 139篇 |
2005年 | 151篇 |
2004年 | 136篇 |
2003年 | 97篇 |
2002年 | 136篇 |
2001年 | 104篇 |
2000年 | 117篇 |
1999年 | 102篇 |
1998年 | 81篇 |
1997年 | 79篇 |
1996年 | 91篇 |
1995年 | 63篇 |
1994年 | 73篇 |
1993年 | 64篇 |
1992年 | 91篇 |
1991年 | 98篇 |
1990年 | 65篇 |
1989年 | 67篇 |
1988年 | 106篇 |
1987年 | 83篇 |
1986年 | 87篇 |
1985年 | 85篇 |
1984年 | 39篇 |
1983年 | 31篇 |
1982年 | 39篇 |
1981年 | 32篇 |
1980年 | 32篇 |
1979年 | 42篇 |
1978年 | 26篇 |
1977年 | 27篇 |
1976年 | 39篇 |
1974年 | 29篇 |
1973年 | 26篇 |
1972年 | 28篇 |
1971年 | 26篇 |
排序方式: 共有4060条查询结果,搜索用时 31 毫秒
1.
2.
3.
K. Molloy C. Jonak F.J.S.H. Woei-A-Jin E. Guenova A.M. Busschots A. Bervoets E. Hauben R. Knobler S. Porkert C. Fassnacht R. Cowan E. Papadavid M. Beylot-Barry E. Berti S. Alberti Violetti T. Estrach R. Matin O. Akilov L. Vakeva M. Prince A. Bates M. Bayne R. Wachsmuch U. Wehkamp M. Marschalko O. Servitje D. Turner S. Weatherhead M. Wobser J.A. Sanches P. McKay D. Klemke C. Peng A. Howles J. Yoo F. Evison J. Scarisbrick 《The British journal of dermatology》2020,182(3):770-779
4.
Puberty marks the beginning of a period of dramatic physical, hormonal, and social change. This instability has made adolescence infamous as a time of “storm and stress” and it is well-established that stress during adolescence can be particularly damaging. However, prior stress may also shape the adolescent experience. In the present series of experiments, we observed sex-specific effects of early-life maternal separation stress on the timing of puberty onset in the rat. Specifically, stressed females exhibited earlier pubertal onset compared to standard-reared females, whereas stressed males matured later than their standard-reared counterparts. Further, we demonstrated that a probiotic treatment restores the normative timing of puberty onset in rodents of both sexes. These results are in keeping with previous findings that probiotics reverse stress-induced changes in learned fear behaviors and stress hormone levels, highlighting the remarkable and wide-ranging restorative effects of probiotics in the context of early-life stress. 相似文献
5.
Rodney H. Breau Madzouka B. Kokolo Nahid Punjani Ilias Cagiannos Andrew Beck Naomi Niznick Chieny Buenaventura Juthaporn Cowan Gregory Knoll Franco Momoli Chris Morash Marcel Ruzicka Svetlana Schachkina Alan Tinmouth Hai Yan Xie Dean A. Fergusson 《Transfusion medicine reviews》2014,28(3):145-155
Pelvic vasculature is complex and inconsistent while pelvic bones impede access to pelvic organs. These anatomical characteristics render pelvic surgery inherently difficult, and some of these procedures are frequently associated with blood loss that necessitates blood transfusion. The aim of this study was to review the literature on the use of lysine analogs to prevent bleeding and blood transfusion during pelvic surgery. The objective of this study was to assess the safety and efficacy of lysine analogs during pelvic surgery. A systematic literature search was performed using Medline, Cochrane Register of Clinical Trials, Embase, and the reference lists of relevant articles. Randomized controlled trials or observational cohort studies comparing a lysine analog to placebo or standard care were included. Outcomes collected were blood transfusion, blood loss, thromboembolic adverse events (myocardial infarction, stroke, deep vein thrombosis, and pulmonary embolism), nonthromboembolic adverse events, and death. There were no language limitations. Fifty-six articles reported on 68 comparisons between a lysine analog and an inactive comparator, involving a total of 7244 patients published between 1961 and 2013. Thirty-nine studies evaluated urologic procedures, and 21 evaluated gynecologic procedures. Thirty-six studies (60%) were published before 1980. Of the 43 randomized comparisons, only 30 (44%) had a score of 3 or higher on Jadad's 5-point scale of methodological quality. Among randomized trials, lysine analogs reduced the risk of blood transfusion (pooled odds ratio [OR], 0.47; 95% confidence interval [CI], 0.35-0.64) and blood loss (pooled OR, 0.22; 95% CI, 0.18-0.27). There was a small statistically insignificant increased risk of thromboembolic events (pooled OR, 1.07; 95% CI, 0.72-1.59) and no-thrombotic serious adverse events (pooled OR, 1.11; 95% CI, 0.67-1.83). In the 17 randomized trials published since the year 2000, only 6 thrombotic events were reported, 4 of which occurred in the placebo arm. Lysine analogs did not increase risk of death (pooled OR, 0.91; 95% CI, 0.34-2.48). These results are significant as they indicate that lysine analogs significantly reduce blood loss and blood transfusion during pelvic surgery. Although there does not appear to be a large increase in the risk of thromboembolic and nonthrombotic adverse events, more data are required to definitively assess these outcomes. Based on this review, lysine analogs during pelvic surgery seem to reduce bleeding and blood transfusion requirements. Although there does not seem to be a significant risk of adverse effects, larger studies would help clarify risks, if any, associated with lysine analog use. 相似文献
6.
7.
8.
Desmoplastic and non-desmoplastic ameloblastoma: a comparative clinicopathological analysis 总被引:1,自引:0,他引:1
OBJECTIVES: The aim of this study was to review a large series of ameloblastomas, accessioned during a period of 35 years in a single Oral Pathology Diagnostic Center, for the incidence of desmoplastic ameloblastoma (DA) and in order to analyze the clinical features of this unusual variant.
MATERIALS AND METHODS: All cases diagnosed as ameloblastoma were reviewed and 14 were rediagnosed as DA. These cases were analyzed in terms of gender, patient age, location, clinical diagnosis, radiographic features and recurrence following treatment. Data from DA and non-desmoplastic ameloblastoma (NDA) were compared.
RESULTS: The incidence of DA in this series was 8.8%. The mean age of NDA and DA were 39.1 and 38.8 years respectively, and a higher female prevalence was observed in the latter. The mandible was the most affected bone in both groups of tumors, but with a different regional distribution. Most NDA arose in the angle and ramus of the mandible, but the premolar/molar region was the preferential location for DA. The most common radiographic feature in DA was the osteolytic type, either monolocular or multilocular. Most of these cases were clinically diagnosed as ameloblastoma. According to follow-up data available, 21.4% of DA and 10.1% of NDA recurred.
CONCLUSIONS: The results of this study do not support the hypothesis that DA should be a separate clinicopathological entity. It seems most likely that DA is another his-tologic variant of ameloblastoma. 相似文献
MATERIALS AND METHODS: All cases diagnosed as ameloblastoma were reviewed and 14 were rediagnosed as DA. These cases were analyzed in terms of gender, patient age, location, clinical diagnosis, radiographic features and recurrence following treatment. Data from DA and non-desmoplastic ameloblastoma (NDA) were compared.
RESULTS: The incidence of DA in this series was 8.8%. The mean age of NDA and DA were 39.1 and 38.8 years respectively, and a higher female prevalence was observed in the latter. The mandible was the most affected bone in both groups of tumors, but with a different regional distribution. Most NDA arose in the angle and ramus of the mandible, but the premolar/molar region was the preferential location for DA. The most common radiographic feature in DA was the osteolytic type, either monolocular or multilocular. Most of these cases were clinically diagnosed as ameloblastoma. According to follow-up data available, 21.4% of DA and 10.1% of NDA recurred.
CONCLUSIONS: The results of this study do not support the hypothesis that DA should be a separate clinicopathological entity. It seems most likely that DA is another his-tologic variant of ameloblastoma. 相似文献
9.
10.
Kim D Harrison Beverly D Hiebert Arash Panahifar Janna M Andronowski Amir M Ashique Gavin A King Terra Arnason Kurtis J Swekla Peter Pivonka David ML Cooper 《Journal of bone and mineral research》2020,35(11):2211-2228
Cortical bone porosity is intimately linked with remodeling, is of growing clinical interest, and is increasingly accessible by imaging. Thus, the potential of animal models of osteoporosis (OP) to provide a platform for studying how porosity develops and responds to interventions is tremendous. To date, rabbit models of OP have largely focused on trabecular microarchitecture or bone density; some such as ovariectomy (OVX) have uncertain efficacy and cortical porosity has not been extensively reported. Our primary objective was to characterize tibial cortical porosity in rabbit-based models of OP, including OVX, glucocorticoids (GC), and OVX + GC relative to controls (SHAM). We sought to: (i) test the hypothesis that intracortical remodeling is elevated in these models; (ii) contrast cortical remodeling and porosity in these models with that induced by parathyroid hormone (1–34; PTH); and (iii) contrast trabecular morphology in the proximal tibia across all groups. Evidence that an increase in cortical porosity occurred in all groups was observed, although this was the least robust for GC. Histomorphometric measures supported the hypothesis that remodeling rate was elevated in all groups and also revealed evidence of uncoupling of bone resorption and formation in the GC and OVX + GC groups. For trabecular bone, a pattern of loss was observed for OVX, GC, and OVX + GC groups, whereas the opposite was observed for PTH. Change in trabecular number best explained these patterns. Taken together, the findings indicated rabbit models provide a viable and varied platform for the study of OP and associated changes in cortical remodeling and porosity. Intriguingly, the evidence revealed differing effects on the cortical and trabecular envelopes for the PTH model. © 2020 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).. 相似文献