全文获取类型
收费全文 | 3753篇 |
免费 | 212篇 |
国内免费 | 5篇 |
专业分类
耳鼻咽喉 | 36篇 |
儿科学 | 157篇 |
妇产科学 | 56篇 |
基础医学 | 467篇 |
口腔科学 | 291篇 |
临床医学 | 251篇 |
内科学 | 523篇 |
皮肤病学 | 67篇 |
神经病学 | 175篇 |
特种医学 | 83篇 |
外科学 | 702篇 |
综合类 | 66篇 |
一般理论 | 4篇 |
预防医学 | 153篇 |
眼科学 | 112篇 |
药学 | 481篇 |
1篇 | |
中国医学 | 35篇 |
肿瘤学 | 310篇 |
出版年
2023年 | 35篇 |
2022年 | 97篇 |
2021年 | 162篇 |
2020年 | 96篇 |
2019年 | 114篇 |
2018年 | 151篇 |
2017年 | 107篇 |
2016年 | 137篇 |
2015年 | 139篇 |
2014年 | 169篇 |
2013年 | 225篇 |
2012年 | 348篇 |
2011年 | 335篇 |
2010年 | 162篇 |
2009年 | 152篇 |
2008年 | 194篇 |
2007年 | 185篇 |
2006年 | 133篇 |
2005年 | 88篇 |
2004年 | 89篇 |
2003年 | 68篇 |
2002年 | 64篇 |
2001年 | 60篇 |
2000年 | 45篇 |
1999年 | 43篇 |
1998年 | 15篇 |
1997年 | 13篇 |
1996年 | 16篇 |
1995年 | 14篇 |
1992年 | 44篇 |
1991年 | 37篇 |
1990年 | 33篇 |
1989年 | 41篇 |
1988年 | 23篇 |
1987年 | 36篇 |
1986年 | 24篇 |
1985年 | 20篇 |
1984年 | 22篇 |
1983年 | 23篇 |
1981年 | 15篇 |
1980年 | 10篇 |
1979年 | 15篇 |
1977年 | 15篇 |
1976年 | 14篇 |
1975年 | 14篇 |
1974年 | 24篇 |
1973年 | 13篇 |
1972年 | 11篇 |
1970年 | 9篇 |
1967年 | 9篇 |
排序方式: 共有3970条查询结果,搜索用时 15 毫秒
91.
92.
93.
Tracy-Ann Moo MD Lydia Choi MD Candice Culpepper MD Cristina Olcese BS Alexandra Heerdt MD Lisa Sclafani MD Tari A. King MD Anne S. Reiner MPH Sujata Patil PhD Edi Brogi MD Monica Morrow MD Kimberly J. Van Zee MS MD 《Annals of surgical oncology》2014,21(1):86-92
Background
For breast-conserving surgery, the method of margin assessment that most frequently achieves negative margins without increasing the volume of tissue excised is uncertain. We examined our institutional experience with three different margin assessment methods used by six experienced breast surgeons.Methods
Patients undergoing breast-conserving surgery for invasive carcinoma during July to December of a representative year during which each method was performed (perpendicular, 2003; tangential, 2004; cavity shave, 2011) were included. The effect of margin method on the positive margin rate at first excision and the total volume excised to achieve negative margins were evaluated by multivariable analysis, by surgeon, and by tumor size and presence of extensive intraductal component (EIC).Results
A total of 555 patients were identified, as follows: perpendicular, 140; tangential, 124; and cavity shave, 291. The tangential method had a higher rate of positive margins at first excision than the perpendicular and cavity-shave methods (49, 15, 11 %, respectively; p < 0.0001). Median volumes to achieve negative margins were similar (55 ml perpendicular; 64 ml tangential; 62 ml cavity shave; p = 0.24). Four of six surgeons had the lowest rate of positive margins with the cavity-shave method, which was significant when compared to the tangential method (p < 0.0001) but not the perpendicular method (p = 0.37). The volume excised by the three methods varied by surgeon (p < 0.0001). The perpendicular method was optimal for T1 tumors without EIC; the cavity-shave method tended to be superior for T2–T3 tumors and/or EIC.Conclusions
Although the cavity-shave method may decrease the rates of positive margins, its effect on volume is variable among surgeons and may result in an increase in the total volume excised for some surgeons and for small tumors without EIC. 相似文献94.
Melissa Pilewskie MD Cristina Olcese BS Anne Eaton MS Sujata Patil PhD Elizabeth Morris MD Monica Morrow MD Kimberly J. Van Zee MS MD 《Annals of surgical oncology》2014,21(5):1552-1560
Introduction
For women with ductal carcinoma in situ (DCIS) undergoing breast-conserving surgery (BCS), the benefit of magnetic resonance imaging (MRI) remains unknown. Here we examine the relationship of MRI and locoregional recurrence (LRR) and contralateral breast cancer (CBC) for DCIS treated with BCS, with and without radiotherapy (RT).Methods
A total of 2,321 women underwent BCS for DCIS from 1997 to 2010. All underwent mammography, and 596 (26 %) also underwent perioperative MRI; 904 women (39 %) did not receive RT, and 1,391 (61 %) did. Median follow-up was 59 months, and 548 women were followed for ≥8 years. The relationship between MRI and LRR was examined using multivariable analysis.Results
There were 184 LRR events; 5- and 8-year LRR rates were 8.5 and 14.6 % (MRI), respectively, and 7.2 and 10.2 % (no-MRI), respectively (p = 0.52). LRR was significantly associated with age, menopausal status, margin status, RT, and endocrine therapy. After controlling for these variables and family history, presentation, number of excisions, and time period of surgery, there remained no trend toward association of MRI and lower LRR [hazard ratio (HR) 1.18, 95 % confidence interval (CI) 0.79–1.78, p = 0.42]. Restriction of analysis to the no-RT subgroup showed no association of MRI with lower LRR rates (HR 1.36, 95 % CI 0.78–2.39, p = 0.28). No difference in 5- or 8-year rates of CBC was seen between the MRI (3.5 and 3.5 %) and no-MRI (3.5 and 5.1 %) groups (p = 0.86).Conclusions
We observed no association between perioperative MRI and lower LRR or CBC rates in patients with DCIS, with or without RT. In the absence of evidence that MRI improves outcomes, the routine perioperative use of MRI for DCIS should be questioned. 相似文献95.
96.
97.
Thu Trang Do Basanagouda B. Patil Samarendra P. Singh Soniya D. Yambem Krishna Feron Kostya Ostrikov John M. Bell Prashant Sonar 《RSC advances》2018,8(68):38919
Two polymers based on (3E,7E)-3,7-bis(2-oxoindolin-3-ylidene)benzo[1,2-b:4,5-b′]difuran-2,6(3H,7H)-dione (BIBDF) coupled with (E)-2-(2-(thiophen-2-yl)vinyl)thiophene (TVT) or dithienylbenzothiadiazole (TBT), namely PBIBDF-TVT and PBIBDF-TBT were synthesized via the Stille coupling reaction. The effect of benzothiadiazole or vinylene-π spacer of the copolymers on optical properties, energy levels, electronic device performance and microstructure were studied. It was found that PBIBDF-TBT based OFET devices, annealed at 180 °C, showed better performance with the highest electron mobility of 2.9 × 10−2 cm2 V s−1 whereas PBIBDF-TVT polymer exhibited 5.0 × 10−4 cm2 V s−1. The two orders of magnitude higher electron mobility of PBIBDF-TBT over PBIBDT-TVT is a clear indicator of the better charge transport ability of this polymer semiconductor arising from its higher crystallinity and better donor–acceptor interaction.Bottom-gate-top-contact OFET device structure using PBIBDF-TVT and PBIBDF-TBT based polymer semiconductors. 相似文献
98.
Vaibhav Bagaria Raju Vaishya 《Diabetes & Metabolic Syndrome: Clinical Research & Reviews》2021,15(4):102137
As COVID 19 continues to over burden the healthcare system globally, the scientists are relentlessly pursuing research and publishing copious data on relevant managements strategies for the infection. This short communication has attempted to simplify the available information on the subject in a manner that is easy to understand and implement in clinical setting. COVID 19 is not a single disease but a spectrum and should be classified based on clinical, radiological and laboratory parameters. A simple yet powerful way is to classify COVID 19 as COVIN – COVID Infection but no disease; COVIRI – COVID infection with predominant respiratory symptoms; COVIDI - COVID infection leading to an abnormal immune response and COVID S- referring to the sequalae of an acute COVID Infection. A clinical subtype specific approach may result in easier communication between healthcare providers which in turn may improve patient outcomes by providing targeted therapy. 相似文献
99.
100.
Despite the magnitude of the public health problem presented by respiratory diseases, there have been few studies concerned with vocational rehabilitation (VR) potential of patients with chronic obstructive pulmonary disease (COPD). Certain physiologic variables which show a high degree of relationship to VR success are identified. The three independent variables which most highly correlate with the VR potential of patients with COPD are the percentages predicted for the first-second forced expiratory volume (FEV(1.0)), forced expiratory flow between 25 and 75 percent of the forced vital capacity (FEF(25-75 percent)), and maximum voluntary ventilation (MVV). The mean "cutting" percentages for inclusion in VR programs were 50, 27, and 40, respectively. The emotional variables studied do not differentiate potential VR success or failure as clearly as the physiologic factors. The criteria set forth not only can be used by rehabilitation workers but could serve as a basis for future demonstration studies. 相似文献