全文获取类型
收费全文 | 2073篇 |
免费 | 178篇 |
国内免费 | 7篇 |
专业分类
耳鼻咽喉 | 32篇 |
儿科学 | 91篇 |
妇产科学 | 58篇 |
基础医学 | 247篇 |
口腔科学 | 47篇 |
临床医学 | 172篇 |
内科学 | 408篇 |
皮肤病学 | 29篇 |
神经病学 | 103篇 |
特种医学 | 474篇 |
外科学 | 160篇 |
综合类 | 76篇 |
预防医学 | 106篇 |
眼科学 | 30篇 |
药学 | 127篇 |
1篇 | |
中国医学 | 3篇 |
肿瘤学 | 94篇 |
出版年
2023年 | 8篇 |
2022年 | 10篇 |
2021年 | 18篇 |
2020年 | 19篇 |
2019年 | 21篇 |
2018年 | 27篇 |
2017年 | 36篇 |
2016年 | 31篇 |
2015年 | 36篇 |
2014年 | 51篇 |
2013年 | 56篇 |
2012年 | 55篇 |
2011年 | 54篇 |
2010年 | 58篇 |
2009年 | 73篇 |
2008年 | 51篇 |
2007年 | 74篇 |
2006年 | 65篇 |
2005年 | 58篇 |
2004年 | 46篇 |
2003年 | 57篇 |
2002年 | 36篇 |
2001年 | 47篇 |
2000年 | 47篇 |
1999年 | 45篇 |
1998年 | 95篇 |
1997年 | 91篇 |
1996年 | 90篇 |
1995年 | 76篇 |
1994年 | 51篇 |
1993年 | 66篇 |
1992年 | 16篇 |
1991年 | 33篇 |
1990年 | 35篇 |
1989年 | 60篇 |
1988年 | 48篇 |
1987年 | 51篇 |
1986年 | 56篇 |
1985年 | 71篇 |
1984年 | 40篇 |
1983年 | 29篇 |
1982年 | 33篇 |
1981年 | 34篇 |
1980年 | 37篇 |
1979年 | 7篇 |
1978年 | 19篇 |
1977年 | 26篇 |
1976年 | 23篇 |
1975年 | 24篇 |
1974年 | 10篇 |
排序方式: 共有2258条查询结果,搜索用时 15 毫秒
131.
132.
133.
134.
Multiple myeloma: evaluation by CT 总被引:3,自引:0,他引:3
Although patients who have multiple myeloma usually have straightforward clinical symptoms and corroborative radiographs, in some instances, these patients will present atypically, with symptoms suggesting active disease but radiographs that are normal or nonspecific. We reviewed the records of 32 patients who had documented multiple myeloma and had undergone CT examinations, assessing the value of those examinations. Although CT is not indicated in all patients who have multiple myeloma, it is especially useful in patients who have bone pain and normal or nonspecific radiographs. CT provided confirmatory information in all cases in which lesions were seen on radiographs. CT also frequently demonstrated a greater extent of disease than could be appreciated on the radiographs. 相似文献
135.
Insufficiency fractures in the supraacetabular region were identified in five women, aged 55-83 years. Factors contributing to the diminished resistance of their bones included postmenopausal osteoporosis, steroid therapy, radiation therapy, and rheumatoid arthritis. The supraacetabular fractures were seen on routine radiographs as hazy bands of sclerosis located immediately above and parallel to the acetabular roof. All five patients had additional fractures in the spine or pelvis. Supraacetabular insufficiency fractures may be an unsuspected cause of hip pain, especially in older women. 相似文献
136.
137.
138.
139.
140.
Histopathologic excision margin affects local recurrence rate: analysis of 2681 patients with melanomas < or =2 mm thick
下载免费PDF全文
![点击此处可从《Annals of surgery》网站下载免费的PDF全文](/ch/ext_images/free.gif)
OBJECTIVE: Prospective trials have shown that 1-cm and 2-cm margins are safe for melanomas <1 mm thick and > or =1 mm thick, respectively. It is unknown whether narrower margins increase the risk of LR or mortality. SUMMARY BACKGROUND DATA: To determine the relationship between histopathologic excision margin, local recurrence (LR) and survival for patients with melanomas < or =2 mm thick. METHODS: Data were extracted from the Sydney Melanoma Unit database for all patients with cutaneous melanoma < or =2 mm thick, diagnosed up to 1996. Patients with positive excision margins or follow-up <12 months were excluded, leaving 2681 for analysis. Outcome measures were LR (recurrence <5 cm from the excision scar), in-transit recurrence, and disease-specific survival. Factors predicting LR and overall survival were tested with Cox proportional hazards analysis. RESULTS: Median follow-up was 83.8 months. LR was identified in 55 patients (median time to recurrence, 37 months). At 120 months, the actuarial LR rate was 2.9%. Five-year survival after LR was 52.8%. In multivariate analysis, only margin of excision and tumor thickness were predictive of LR (both P = 0.003). When all patients with a margin <0.8 cm in fixed tissue (corresponding to a margin of <1 cm in vivo) were excluded from analysis, margin was no longer significant in predicting LR. Thickness, ulceration, and site were predictive of survival, but margin was not (P = 0.49). CONCLUSIONS: Histopathologic margin affects the risk of LR. However, if the in vivo margin is > or =1 cm, it no longer predicts risk of LR. Patient survival is not affected by margin. 相似文献