全文获取类型
收费全文 | 2401篇 |
免费 | 185篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 10篇 |
儿科学 | 60篇 |
妇产科学 | 47篇 |
基础医学 | 292篇 |
口腔科学 | 41篇 |
临床医学 | 284篇 |
内科学 | 559篇 |
皮肤病学 | 30篇 |
神经病学 | 224篇 |
特种医学 | 200篇 |
外科学 | 262篇 |
综合类 | 33篇 |
一般理论 | 1篇 |
预防医学 | 326篇 |
眼科学 | 39篇 |
药学 | 100篇 |
中国医学 | 17篇 |
肿瘤学 | 83篇 |
出版年
2023年 | 12篇 |
2022年 | 23篇 |
2021年 | 56篇 |
2020年 | 25篇 |
2019年 | 35篇 |
2018年 | 59篇 |
2017年 | 39篇 |
2016年 | 48篇 |
2015年 | 40篇 |
2014年 | 45篇 |
2013年 | 89篇 |
2012年 | 123篇 |
2011年 | 123篇 |
2010年 | 74篇 |
2009年 | 65篇 |
2008年 | 84篇 |
2007年 | 116篇 |
2006年 | 99篇 |
2005年 | 81篇 |
2004年 | 70篇 |
2003年 | 70篇 |
2002年 | 66篇 |
2001年 | 62篇 |
2000年 | 47篇 |
1999年 | 50篇 |
1998年 | 46篇 |
1997年 | 34篇 |
1996年 | 41篇 |
1995年 | 34篇 |
1994年 | 37篇 |
1993年 | 29篇 |
1992年 | 39篇 |
1991年 | 36篇 |
1990年 | 34篇 |
1989年 | 59篇 |
1988年 | 55篇 |
1987年 | 42篇 |
1986年 | 31篇 |
1985年 | 44篇 |
1984年 | 25篇 |
1983年 | 19篇 |
1982年 | 22篇 |
1981年 | 17篇 |
1980年 | 25篇 |
1979年 | 27篇 |
1977年 | 26篇 |
1972年 | 15篇 |
1971年 | 11篇 |
1968年 | 14篇 |
1966年 | 12篇 |
排序方式: 共有2608条查询结果,搜索用时 15 毫秒
1.
The ileocecal reservoir (Indiana pouch) is a large volume, low pressure continent reservoir well suited for urinary diversion. The mechanism of continence is believed to be the result of several factors, including the natural ileocecal valve resistance, resistance produced by the plication of the ileal segment and normal peristalsis of the ileum. We report the results of a video-urodynamic study in patients with an Indiana pouch, aimed at establishing the factors that contribute to continence and their relative significance. Video-urodynamic studies clearly demonstrate that continence in this type of urinary reservoir is dependent upon a synergism of the aforementioned factors in combination with the low intraluminal pressure of the detubularized bowel. Video-urodynamic studies offer an objective demonstration of the reservoir dynamics and its continence mechanisms, and provide an insight into the possible etiology of incontinence. Such studies also offer an objective means for critical comparison of the different continent urinary reservoirs. 相似文献
2.
3.
Haven Emerson 《American journal of public health》1939,29(4):337-340
4.
5.
Eric Emerson Janet Robertson Justin Wood 《Journal of Applied Research in Intellectual Disabilities》2004,17(2):77-84
Background The aim of the present study was to identify factors associated with the level of psychological distress reported by family carers of children with intellectual disability living in a large urban conurbation. Method Information was collected by postal questionnaire (or interview for family carers who did not have English as their first language) from the family carers of 408 children with intellectual disability (31% of all children within the area administratively identified as having an intellectual disability). Results Results indicated that 47% of primary carers scored above the threshold for psychological distress on the GHQ and that scoring above the threshold was strongly related to the emotional and behavioural needs of the index child and South‐Asian ethnicity and moderately associated with the severity of the child's delay in communication. Conclusions The rates of psychological distress (47% overall, 70% among South‐Asian carers) were markedly higher than that found in previous studies of carers supporting a child with intellectual disabilities. It is suggested that these elevated rates of psychological distress may be mediated by socio‐economic deprivation. 相似文献
6.
Release of soluble transferrin receptor from the surface of human leukemic HL60 cells 总被引:2,自引:0,他引:2
Information regarding transferrin (Tf) receptor degradation is largely incomplete. HL60 cells were shown to release to their growth medium a Tf-binding protein which could be immunoprecipitated by anti-Tf receptor monoclonal antibodies (MoAbs) B3/25 and OKT9. Soluble Tf receptor was detected in the medium within one hour of replating of cells, and its release was inhibited at 4 degrees C. The affinity of Tf for the soluble receptor released by cells (kd = 2.3 x 10(-10) mol/L) was slightly lower than its affinity for the detergent-solubilized cellular receptor (kd = 1.2 x 10(-10) mol/L). 125I-Tf internalized and released by cells subsequently bound to Tf receptor released by the same cells, and soluble Tf receptor in the conditioned medium (CM) inhibited 125I-Tf binding to intact cells. The soluble Tf receptor isolated from the CM was smaller (78,000 daltons) than the cell surface receptor (94,000 daltons) when analyzed by gel electrophoresis under reducing conditions. Isolated cell membranes readily released soluble receptor; however, this release could be blocked by protease inhibitors. The soluble Tf receptor may represent the extracytoplasmic domain of the cellular Tf receptor released from the surface of HL60 cells through proteolytic cleavage by a membrane-based protease. 相似文献
7.
8.
The purpose of this study was to examine motor learning and retention given extensive practice in two fundamentally different movement sequences. One sequence was a memory-driven task (performing a series of whole body positions from memory) and the other a context-driven task (buttoning). Practice took place over 3 weeks, with performance measured weekly; retention was measured weekly for 3 weeks after practice. There were 7 people with Parkinson's disease (PD) and 7 age-matched neurologically healthy people who participated in this study. Both groups improved performance on both tasks with practice, with the majority of the change for the PD group occurring between 1 and 2 weeks of practice. Although those with PD did not necessarily perform as well as age-matched controls, they learned both sequences in a manner similar to age-matched controls, and exhibited retention across the 3-week retention interval. If people with PD are given sufficient practice they can learn and retain both memory-based and context-driven movement sequences as well as age-matched controls. The results provide support for maintaining physical activity and for intervention through movement therapy. 相似文献
9.
Prior studies have shown that pneumothorax is one of the more difficult entities to diagnose with digitized radiography. This study was designed to test whether increasing resolution from 1.25 to 2.5 line pairs per millimeter (lp/mm) and image processing (edge enhancement from unsharp masking) would increase accuracy and confidence in the diagnosis of pneumothorax, as well as normal cases and other forms of lung disease. Conventional radiographs were digitized with use of a laser reader and then reformatted as film hard copy. Eleven observers read 35 cases reformatted in three different ways (1.25 lp/mm, 2.5 lp/mm, 1.25 lp/mm unsharp mask). The images with finer resolution (2.5 lp/mm) and unsharp mask images were superior to those with coarser resolution (1.25 lp/mm) for the diagnosis of pneumothorax. There was no difference in diagnostic accuracy for normal patients. For abnormalities other than pneumothorax, the unsharp mask images were significantly worse. Confidence in the diagnosis of pneumothorax and other abnormalities was highest with the finest resolution (2.5 lp/mm). 相似文献
10.