全文获取类型
收费全文 | 302篇 |
免费 | 15篇 |
国内免费 | 11篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 14篇 |
妇产科学 | 1篇 |
基础医学 | 20篇 |
口腔科学 | 4篇 |
临床医学 | 22篇 |
内科学 | 47篇 |
皮肤病学 | 5篇 |
神经病学 | 2篇 |
特种医学 | 160篇 |
外科学 | 11篇 |
综合类 | 5篇 |
预防医学 | 5篇 |
眼科学 | 6篇 |
药学 | 14篇 |
肿瘤学 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2018年 | 6篇 |
2017年 | 1篇 |
2016年 | 5篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 7篇 |
2012年 | 4篇 |
2011年 | 1篇 |
2010年 | 10篇 |
2009年 | 8篇 |
2008年 | 3篇 |
2007年 | 8篇 |
2006年 | 4篇 |
2005年 | 4篇 |
2004年 | 9篇 |
2003年 | 4篇 |
2002年 | 5篇 |
2001年 | 8篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 16篇 |
1997年 | 18篇 |
1996年 | 17篇 |
1995年 | 16篇 |
1994年 | 17篇 |
1993年 | 15篇 |
1991年 | 1篇 |
1990年 | 3篇 |
1989年 | 10篇 |
1988年 | 13篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 23篇 |
1984年 | 8篇 |
1983年 | 13篇 |
1982年 | 10篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1978年 | 2篇 |
1977年 | 4篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1966年 | 1篇 |
1963年 | 1篇 |
排序方式: 共有328条查询结果,搜索用时 0 毫秒
101.
Nuclear magnetic resonance imaging of atherosclerotic disease 总被引:3,自引:0,他引:3
Herfkens RJ; Higgins CB; Hricak H; Lipton MJ; Crooks LE; Sheldon PE; Kaufman L 《Radiology》1983,148(1):161
102.
103.
104.
105.
106.
107.
Instrument monitoring of vital signs in neonates undergoing magnetic resonance (MR) imaging can be difficult because of the unique environmental restrictions imposed by the imager. The authors present their experience with monitoring more than 50 newborn infants and discuss the interaction of monitoring devices with the MR imager. Several MR-compatible monitors allow continuous evaluation of body temperature, heart rate, blood pressure, and auscultation of heart sounds and respiration in mechanically ventilated infants. Signal-to-noise (S/N) ratio measurements taken during imaging of the head of an infant with these monitors in place did not differ appreciably from the ratio obtained during imaging without monitors. Tip angles should be optimized to account for widely varying head size among neonates, since adverse monitoring effects are significantly compounded by improper tip angle adjustment. 相似文献
108.
Lipomatous tumors and tumors with fatty component: MR imaging potential and comparison of MR and CT results 总被引:4,自引:0,他引:4
This retrospective study was performed to assess the potential of magnetic resonance (MR) imaging for demonstrating various types of lipomatous tumors and tumors with fatty component and to compare the results of MR with those of computed tomography (CT). MR examinations of 17 patients with 18 lipomatous tumors (16, benign; two, liposarcoma) and two patients with fibrosarcomas were reviewed; CT scans were available for comparison in all patients. In the 16 benign lesions (12 benign lipomas, two ovarian dermoid cysts, and two renal angiomyolipomas), the fatty component of the tumors was readily demonstrated by both MR and CT. The T1 and T2 relaxation times and spin density of benign lipomatous tumors were in a range similar to those of normal subcutaneous fat. Differentiation between lipomas and liposarcomas was achieved with both MR and CT. On MR images using a short repetition time (TR = .5 sec), liposarcomas (long T1) were imaged with a lower MR intensity than lipomas (short T1). 相似文献
109.
110.
Obstetrical magnetic resonance imaging: fetal anatomy 总被引:8,自引:1,他引:7
McCarthy SM; Filly RA; Stark DD; Hricak H; Brant-Zawadzki MN; Callen PW; Higgins CB 《Radiology》1985,154(2):427-432
Nine patients who were 34-36 weeks pregnant underwent magnetic resonance (MR) imaging. Sagittal images using spin echo technique (TR 2.0 sec, TE 28 msec) were optimal for delineating fetal anatomy. The fetal cardiovascular, pulmonary, and central nervous systems were depicted in all cases. The heart and major vessels were readily seen due to the natural contrast of flowing blood. The intensity of the fluid-filled lungs greatly increased with a longer TR or TE, delimiting thorax from liver. The brain was relatively featureless due to the lack of gray-white matter differentiation. The umbilical cord within the amniotic fluid and its insertion into the placenta and fetus was identified in all cases. MR is a new modality for fetal imaging that offers tissue-characterization information that complements the superior anatomic detail of ultrasound scanning. 相似文献