全文获取类型
收费全文 | 145771篇 |
免费 | 32767篇 |
国内免费 | 1649篇 |
学科分类
医药卫生 | 180187篇 |
出版年
2024年 | 557篇 |
2023年 | 5222篇 |
2022年 | 1341篇 |
2021年 | 4633篇 |
2020年 | 6157篇 |
2019年 | 3151篇 |
2018年 | 8295篇 |
2017年 | 8376篇 |
2016年 | 9430篇 |
2015年 | 10299篇 |
2014年 | 13112篇 |
2013年 | 15177篇 |
2012年 | 8631篇 |
2011年 | 7877篇 |
2010年 | 9291篇 |
2009年 | 11157篇 |
2008年 | 6519篇 |
2007年 | 5154篇 |
2006年 | 5889篇 |
2005年 | 4160篇 |
2004年 | 3244篇 |
2003年 | 2619篇 |
2002年 | 2296篇 |
2001年 | 3135篇 |
2000年 | 2362篇 |
1999年 | 2547篇 |
1998年 | 2391篇 |
1997年 | 2116篇 |
1996年 | 2130篇 |
1995年 | 1839篇 |
1994年 | 1212篇 |
1993年 | 1026篇 |
1992年 | 1058篇 |
1991年 | 931篇 |
1990年 | 773篇 |
1989年 | 760篇 |
1988年 | 733篇 |
1987年 | 602篇 |
1986年 | 519篇 |
1985年 | 449篇 |
1984年 | 361篇 |
1983年 | 403篇 |
1982年 | 274篇 |
1981年 | 247篇 |
1980年 | 156篇 |
1979年 | 141篇 |
1978年 | 187篇 |
1977年 | 153篇 |
1976年 | 128篇 |
1974年 | 130篇 |
排序方式: 共有10000条查询结果,搜索用时 372 毫秒
81.
82.
Breast Elastography: How to Perform and Integrate Into a “Best-Practice” Patient Treatment Algorithm
Breast elastography has been available for more than 15 years but is not widely incorporated into clinical practice. Many publications report extremely high accuracy for various breast elastographic techniques. However, results in the literature are extremely variable. This variability is most likely due to variations in technique, a relatively steep learning curve, and variability in methods between vendors. This article describes our protocol for performing breast elastography using both strain elastography and shear wave elastography, which produces high sensitivity and specificity. Additionally, we will describe the most commonly known false-positive and false-negative lesions as well as how to detect them. 相似文献
83.
The midwifery art has emphasised the uniqueness of human beings throughout its Nordic history. The educated Nordic midwife has in the last decade celebrated several hundred years of memories. This article studies how the key ideas of the midwifery art and patterns of ideas become evident in the zeitgeist from the beginning of the 19th century to the millennium in the Nordic countries. The legacy and pattern of ideas of the art of midwifery are interpreted in relation to the texts of the selected historical sources and based on Ricoeur's phenomenological-hermeneutic approach to the text and further to the dedication of understanding and interpretation. The historical sources refer to unprinted primary sources from historical archives and printed secondary and tertiary sources. The patterns of ideas include a tripartite whole: the true cultivation of the head, the philosophy and aesthetics of the hand, the strength of the heart and the drive of calling. These ideas open for unique visions and attest to the evident in modern midwives. Today's midwives have academic training with examinations, and the education is based on scientific evidence. The midwife profession is authorised by the state and supervised by the authorities. 相似文献
84.
85.
86.
87.
88.
Comparative outcomes of vascular access in patients older than 70 years with end-stage renal disease
Deokbi Hwang Sujin Park Hyung-Kee Kim Seung Huh 《Journal of vascular surgery》2019,69(4):1196-1206.e5
Objective
The advantage of arteriovenous fistulas (AVFs) in older patients requiring dialysis is controversial. We reviewed our vascular access experience in patients ≥70 years of age (older group) compared with younger patients.Methods
We analyzed consecutive patients who underwent access surgery between 2013 and 2016. Primary success (PS) and primary patency (PP) data were analyzed between the older and younger groups before and after propensity score matching of the patients' characteristics and access composition. PS was defined as the achievement of access function that was amenable to two sessions of successful cannulation without early occlusion or maturation failure requiring revision. PP was defined as the time with uninterrupted patency without intervention.Results
A total of 594 consecutive accesses were created among 563 patients, of whom 119 were allocated into each group after propensity score matching. In the whole cohort, 193 accesses (32.5%) were performed in older patients. AVFs were performed in 130 (67.4%) older patients and 293 (73.1%) younger patients. Regarding AVFs, the PS rate (83.6% in the older group vs 94.3% in the younger group; P = .001) and the overall PP at 6 and 12 months (73.1% and 57.1%, respectively, in the older group vs 86.7% and 77.7%, respectively, in the younger group; P = .009) were lower in the older group than in the younger group. However, no differences were found in the PS and PP rates for arteriovenous grafts between groups. Regarding the AVF location, the PS rate for forearm AVFs was significantly lower in the older group than in the younger group (76% vs 93%; P < .001); however, the PS rate of the upper arm was not different between the groups (94% vs 97%; P = .425). In the patients with PS, the PP rate of AVFs was similar between the two groups. In the older group with forearm AVFs, the median diameter of the radial artery was larger in the patients with PS than in the patients without PS (2.20 mm with PS vs 2.00 mm without PS; P = .008). The propensity score matching results demonstrated similar trends for the whole cohort, with lower PS (P = .042) and PP rates (P = .023) for AVF in the older group.Conclusions
The outcomes after AVF were poorer in the older group than in the younger group, which was primarily due to unsatisfactory outcomes in patients with forearm AVFs. Thus, stricter criteria, especially regarding the radial artery diameter, should be applied for forearm AVFs in older patients, and additional research is necessary to delineate the risk factors for primary failure. 相似文献89.
90.
Marie V. Plaisime PhD MPH Marie Jipguep-Akhtar PhD Joseph J. Locascio PhD Harolyn M. E. Belcher MD MHS Rachel R. Hardeman PhD MPH Katherine Picho-Kiroga PhD Sylvia P. Perry PhD Sean M. Phelan PhD MPH Michelle van Ryn PhD LMFT MPH John F. Dovidio PhD 《Health services research》2023,58(Z2):229-237