收费全文 | 1413233篇 |
免费 | 104247篇 |
国内免费 | 2202篇 |
耳鼻咽喉 | 18497篇 |
儿科学 | 45098篇 |
妇产科学 | 37800篇 |
基础医学 | 208629篇 |
口腔科学 | 37729篇 |
临床医学 | 132559篇 |
内科学 | 279381篇 |
皮肤病学 | 29769篇 |
神经病学 | 116710篇 |
特种医学 | 52005篇 |
外国民族医学 | 278篇 |
外科学 | 200801篇 |
综合类 | 27724篇 |
现状与发展 | 6篇 |
一般理论 | 760篇 |
预防医学 | 115783篇 |
眼科学 | 32234篇 |
药学 | 102229篇 |
7篇 | |
中国医学 | 2202篇 |
肿瘤学 | 79481篇 |
2021年 | 11817篇 |
2019年 | 12410篇 |
2018年 | 16327篇 |
2017年 | 12455篇 |
2016年 | 13741篇 |
2015年 | 15954篇 |
2014年 | 22196篇 |
2013年 | 34035篇 |
2012年 | 46978篇 |
2011年 | 50010篇 |
2010年 | 28789篇 |
2009年 | 27563篇 |
2008年 | 47404篇 |
2007年 | 50574篇 |
2006年 | 49767篇 |
2005年 | 49188篇 |
2004年 | 47247篇 |
2003年 | 45176篇 |
2002年 | 43742篇 |
2001年 | 57275篇 |
2000年 | 57990篇 |
1999年 | 49439篇 |
1998年 | 15347篇 |
1997年 | 13921篇 |
1996年 | 14085篇 |
1995年 | 13244篇 |
1994年 | 12322篇 |
1992年 | 39078篇 |
1991年 | 38487篇 |
1990年 | 37173篇 |
1989年 | 35934篇 |
1988年 | 33374篇 |
1987年 | 32627篇 |
1986年 | 31233篇 |
1985年 | 29564篇 |
1984年 | 22972篇 |
1983年 | 20172篇 |
1982年 | 12739篇 |
1981年 | 11571篇 |
1979年 | 21602篇 |
1978年 | 16175篇 |
1977年 | 13451篇 |
1976年 | 12433篇 |
1975年 | 13302篇 |
1974年 | 16096篇 |
1973年 | 15781篇 |
1972年 | 14840篇 |
1971年 | 13783篇 |
1970年 | 12970篇 |
1969年 | 12252篇 |
Aims
Variations of the anatomy of donor hepatic arteries increase the number of arterial anastomoses during liver transplantation and, possibly, the incidence of hepatic artery thrombosis (HAT). In this study, we describe the arterial anatomic variations in liver grafts procured and transplanted by a single center in Greece, the techniques of arterial anastomosis, and their effect on the incidence of early HAT.Materials and Methods
From January 2013 to December 2017, the arterial anatomy of 116 grafts procured for liver transplantation were recorded, as well as the technique of arterial anastomosis and the incidence of early hepatic artery thrombosis (HAT <30 days).Results
A single hepatic artery was recorded in 72.41% of the procured grafts, an aberrant left hepatic artery (accessory or replaced) in 18 grafts (15.52%), and an aberrant right hepatic artery (accessory or replaced) in 17 grafts (14.66%), while other variations were observed in less than 1% of the procured livers. Of the 116 primary liver transplantations, 6 patients (5.17%) developed early HAT <30 days. Two of these patients (1.72%) had 1 anastomosis of the hepatic artery and 4 (3.45%) had 2 anastomoses due to anatomic variations.Conclusions
Anatomic variations of the hepatic artery in liver grafts is a common finding and increase the incidence of early HAT but not to a degree to make these grafts unusable. 相似文献BACKGROUND
Online physician rating websites are increasingly used by patients to evaluate their doctors. The purpose of this investigation was to evaluate factors associated with better spine surgeon ratings.METHODS
Orthopedic spine surgeons were randomly selected from the North American Spine Society directory utilizing a random number generator. Surgeon profiles on three physician rating websites, namely, www.HealthGrades.com, www.Vitals.com, and www.RateMDs.com, were analyzed to gather qualitative and quantitative data on patients’ perceptions of the surgeons. Independent variables from the websites were analyzed in relation to overall physician or patient satisfaction rating. Comments were coded by subject into following three categories: professional competence, bedside manner, and practice characteristics.RESULTS
A total of 250 surgeons were evaluated, and 92% (n=230) of these doctors had at least one rating among the three websites. The surgeons with a higher average rating had significantly better trust (p<.01), scheduling (p<.01), staff (p<.01), helpfulness (p<.01), and punctuality (p<.01) scores but significantly less experience (p<.05). A linear regression model for the average rating of each surgeon (R2 value=0.754) yielded only following three significant variables: trustworthiness (p<.01), experience match (p<.05), and the average number of negative comments on surgeon's professional competence (p<.05). Trustworthiness (β=0.749) was the strongest predictor variable of physician rating, followed by the number of negative professional competence comments (β=?0.132) and experience match (β=?0.112).CONCLUSIONS
This investigation assessed spine surgeon online patient ratings and categorized factors that patients associate with quality care. Trustworthiness was the most significant predictor of positive ratings, whereas ease of scheduling, quality of staff, helpfulness, and punctuality were also associated with higher patient ratings. Understanding what patients value may help optimize care of spine surgery patients. 相似文献Purpose
New instrument-based techniques for anterior chamber (AC) cell counting can offer automation and objectivity above clinician assessment. This review aims to identify such instruments and its correlation with clinician estimates. 相似文献Introduction
In the United States there has been a large increase in participation in lacrosse for both males and females. The purpose of this study was to analyze the number of head injuries, injury rates (calculated using the reported number of participants) and types of head injuries that are seen in emergency departments in the United States.Methods
We compared injuries between male and female lacrosse participants. This was a retrospective study using a publicly available database produced by the US Consumer Product Safety Commission and information about lacrosse participation from US Lacrosse.Results
A linear regression was performed and showed a positive correlation between number of head injuries to males and time from 2002 to 2010 (R2?=?0.823; p?=?0.001). While the number of injuries to the head in female lacrosse participants was not significant. There was a negative correlation between the number of head injuries to males from 2010 to 2016 (R2?=?0.800; p?=?0.007), but again, there was no significance for female injury count (R2?=?0.417; p?=?0.117). Other significant differences between head injuries in males and females included the mechanism of injury and the type of injury recorded.Conclusion
The most recent data from 2010 to 2016, suggest that both males and females have had a decrease in injury rate. However the total number of female head injuries is not significantly decreasing and as the sport continues to grow there will likely be more total head injuries and visits to the emergency department. 相似文献Methods: A cross-sectional prospective cohort study with 7-day follow-up was conducted. Body composition, cardiorespiratory fitness and biomarkers of cardiometabolic health were measured in thirty-three participants with SCI (> 1 year post injury). Physical activity dimensions were objectively assessed over 7-days.
Results: Activity energy expenditure (r =.43), physical activity level (r =.39), and moderate-to-vigorous physical activity (MVPA) (r =.48) were significantly (P < 0.001) associated with absolute (L/min) peak oxygen uptake (?O2 peak). ?O2 peak was significantly higher in persons performing ≥150 MVPA minutes/week compared to <40 minutes/week (P?=?0.003). Individual physical activity dimensions were not significantly associated with biomarkers of cardiometabolic health. However, body composition characteristics (BMI, waist and hip circumference) showed significant (P < 0.04), moderate (r >.30) associations with parameters of metabolic regulation, lipid profiles and inflammatory biomarkers. Relative ?O2 peak (ml/kg/min) was moderately associated with only insulin sensitivity (r?=?0.37, P?=?0.03).
Conclusions: Physical activity dimensions are associated with cardiorespiratory fitness; however, stronger and more consistent associations suggest that poor cardiometabolic health is associated with higher body fat content. Given these findings, the regulation of energy balance should be an important consideration for researchers and clinicians looking to improve cardiometabolic health in persons with SCI. 相似文献