全文获取类型
收费全文 | 1970篇 |
免费 | 129篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 83篇 |
儿科学 | 198篇 |
妇产科学 | 41篇 |
基础医学 | 191篇 |
口腔科学 | 120篇 |
临床医学 | 157篇 |
内科学 | 316篇 |
皮肤病学 | 34篇 |
神经病学 | 89篇 |
特种医学 | 115篇 |
外科学 | 231篇 |
综合类 | 27篇 |
预防医学 | 151篇 |
眼科学 | 13篇 |
药学 | 66篇 |
中国医学 | 5篇 |
肿瘤学 | 265篇 |
出版年
2023年 | 9篇 |
2022年 | 16篇 |
2021年 | 48篇 |
2020年 | 21篇 |
2019年 | 33篇 |
2018年 | 39篇 |
2017年 | 30篇 |
2016年 | 37篇 |
2015年 | 52篇 |
2014年 | 58篇 |
2013年 | 76篇 |
2012年 | 119篇 |
2011年 | 93篇 |
2010年 | 62篇 |
2009年 | 58篇 |
2008年 | 73篇 |
2007年 | 80篇 |
2006年 | 76篇 |
2005年 | 84篇 |
2004年 | 75篇 |
2003年 | 71篇 |
2002年 | 61篇 |
2001年 | 55篇 |
2000年 | 44篇 |
1999年 | 55篇 |
1998年 | 32篇 |
1997年 | 30篇 |
1996年 | 22篇 |
1995年 | 21篇 |
1994年 | 13篇 |
1993年 | 25篇 |
1992年 | 46篇 |
1991年 | 37篇 |
1990年 | 46篇 |
1989年 | 39篇 |
1988年 | 28篇 |
1987年 | 26篇 |
1986年 | 27篇 |
1985年 | 28篇 |
1984年 | 16篇 |
1983年 | 19篇 |
1982年 | 19篇 |
1981年 | 15篇 |
1980年 | 17篇 |
1978年 | 14篇 |
1977年 | 17篇 |
1976年 | 15篇 |
1974年 | 11篇 |
1973年 | 15篇 |
1972年 | 17篇 |
排序方式: 共有2102条查询结果,搜索用时 575 毫秒
51.
Kaitlyn J. Kelly Emily Winslow David Kooby Neha L. Lad Alexander A. Parikh Charles R. Scoggins Syed Ahmad Robert C. Martin Shishir K. Maithel H. J. Kim Nipun B. Merchant Clifford S. Cho Sharon M. Weber 《Journal of gastrointestinal surgery》2013,17(7):1209-1217
Introduction
Current National Comprehensive Cancer Network guidelines recommend neoadjuvant therapy for borderline resectable pancreatic adenocarcinoma to increase the likelihood of achieving R0 resection. A consensus has not been reached on the degree of venous involvement that constitutes borderline resectability. This study compares the outcome of patients who underwent pancreaticoduodenectomy with or without vein resection without neoadjuvant therapy.Methods
A multi-institutional database of patients who underwent pancreaticoduodenectomy was reviewed. Patients who required vein resection due to gross vein involvement by tumor were compared to those without evidence of vein involvement.Results
Of 492 patients undergoing pancreaticoduodenectomy, 70 (14 %) had vein resection and 422 (86 %) did not. There was no difference in R0 resection (66 vs. 75 %, p?=?NS). On multivariate analysis, vein involvement was not predictive of disease-free or overall survival.Conclusion
This is the largest modern series examining patients with or without isolated vein involvement by pancreas cancer, none of whom received neoadjuvant therapy. Oncological outcome was not different between the two groups. These data suggest that up-front surgical resection is an appropriate option and call into question the inclusion of isolated vein involvement in the definition of “borderline resectable disease.” 相似文献52.
53.
Merchant Rutvij Goldin Aleah Manjanatha Deepa Harter Claire Chandler Judy Lipp Amanda Nguyen Theresa Naslund John A. 《The Psychiatric quarterly》2022,93(2):613-625
Psychiatric Quarterly - This study investigated whether with disruptions in care due to the COVID-19 pandemic, persons who self-identified as living with a mental health condition increased their... 相似文献
54.
55.
56.
57.
Reshma A. Merchant R. M. van Dam L. W. L. Tan M. Y. Lim J. L. Low J. E. Morley 《The journal of nutrition, health & aging》2018,22(9):1060-1065
Introduction
Low levels of 25-hydroxyvitamin D (25(OH)D) has been associated with many negative health outcomes including falls and fractures. 25(OH)D is largely bound to vitamin D binding protein (VDBP). There is increasing evidence that free or bioavailable 25(OH)D may be a better measure of vitamin D deficiency.Objective
To determine the prevalence of 25(OH)D deficiency and VDBP levels in multi-ethnic population, and its impact on muscle strength.Design and methods
Cross-sectional study of older adults in Western region of Singapore. 295 participants from three ethnic groups were selected from the Healthy Older People Everyday (HOPE) cohort for measurements of total 25(OH)D and VDBP levels. Total 25(OH)D, VDBP, frailty status, Timed-Up-and-Go (TUG) and grip strength (GS) were assessed. Albumin, free and bioavailable 25(OH)D were only available for 256 participants.Results
53% of Malay and 55% of Indians were deficient in 25(OH)D compared with 18.2% of ethnic Chinese participants. Chinese also had higher total 25(OH)D concentrations with a mean of 29.1 ug/l, (p = <0.001). Chinese had the lowest level of VDBP (169.6ug/ml) followed by Malay (188.8 ug/ml) and Indian having the highest (220.1 ug/ml). Calculated bioavailable and free 25(OH)D levels were significantly higher in Chinese, followed by Malays and Indians, which also correlated with better grip strength measures amongst the Chinese.Conclusion
The Malays and Indians had overall lower free, bioavailable and total 25(OH)D compared with ethnic Chinese. Chinese ethnic group also had the lowest VDBP and better overall grip strength.58.
Sandra H. Soto Stephanie Sanz Kathleen M. Merchant Jeanne F. Nichols Elva M. Arredondo 《Journal of nutrition education and behavior》2018,50(10):1026-1031
Objective
To assess the feasibility, including demand for and acceptability of a physical activity (PA) intervention among pregnant Latinas recruited at the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).Methods
Women <20 weeks gestation and self-reporting <150 minutes of PA/wk were recruited from 2 WIC locations in Southern California. The 9-wk, promotora-led intervention included 1-hour sessions and 2 walking groups/wk.Results
WIC was supportive of recruitment, intervention, and evaluation activities. Of an estimated pool of 525 women at <20 wks gestation, 141 expressed interest, 108 were screened for eligibility, and 21 were enrolled. Of the 21 who enrolled, 12 completed the postintervention assessment (7 in the participant group and 5 in the nonparticipant group).Conclusions and Implications
Demand and acceptability will need to be improved before this intervention can be considered feasible, potentially by extending eligibility and improving access to intervention. 相似文献59.
Antonio Caycedo-Marulanda Sunil Patel Shaila Merchant Carl Brown 《World journal of gastrointestinal surgery》2020,12(5):203-207
The introduction of new surgical techniques and technologies has traditionally been unregulated. In many settings surgeons frequently adopt novel procedures without following a structured program of implementation or supervision. The appearance of innovative technology played a pivotal role in the advancement of new surgical techniques during the industrial revolution. Innovation has been an essential component of surgical development, which led to contemporary surgical techniques such as minimally invasive surgery. Different initiatives have been developed to guide the safe introduction of new surgical techniques and other procedures. Those include comprehensive concepts such as the Idea, Development, Exploration, Assessment, Long-term study framework, which could be particularly relevant when reflecting on the novel transanal total mesorectal excision (taTME), introduced a decade ago. This relatively novel and complex procedure promised to overcome some of the major limitations of traditional surgical approaches for rectal cancer. According to the Idea, Development, Exploration, Assessment, Long-term study framework, taTME is in the phase of exploration, where there is an existing and increasing number of reports being published as the experience grows. The current management of rectal cancer is in a state of radical evolution, with multiple options that were not previously available. TaTME is only one technique amongst many which could be part of a rectal cancer surgeon’s armamentarium; however, it requires further rigorous study and evaluation. 相似文献
60.
Sulaiman Nanji Zuhaib M. Mir Safiya Karim Kelly E. Brennan Sunil V. Patel Shaila J. Merchant Christopher M. Booth 《HPB : the official journal of the International Hepato Pancreato Biliary Association》2021,23(3):404-412
BackgroundPrior work has shown associations between blood transfusion (BT) and inferior outcomes during resection for colorectal cancer liver metastases (CRLM). Herein, we describe short and long-term outcomes relating to perioperative BT in routine clinical practice.MethodsAll CRLM resections in Ontario, Canada from 2002 to 2009 were identified using the Ontario Cancer Registry. Log-binomial regression and Cox regression were used to explore factors associated with receipt of BT and the association of BT with 5-year cancer specific (CSS) and overall survival (OS), respectively.ResultsThe study included 1310 patients; 31% (403/1310) had perioperative BT. Transfused patients had longer median length of stay (9 vs. 7 days, p < 0.001), higher 90-day mortality (9% vs. 1%, p < 0.001), greater 90-day readmission (28% vs. 16%, p < 0.001), and inferior 5-year CSS (41% vs. 48%, p = <0.001) and OS (38% vs. 47%, p < 0.001). Transfusion was independently associated with inferior CSS (HR = 1.35, 95% CI: 1.11–1.63) and OS (HR = 1.30, 95% CI: 1.10–1.53), however, excluding 90-day postoperative deaths showed these associations were no longer significant.ConclusionPerioperative BT is common in patients undergoing resection of CRLM. While transfusion is associated with greater morbidity, mortality, and inferior survival, after excluding early postoperative deaths, BT does not appear to be independently associated with CSS or OS. 相似文献