全文获取类型
收费全文 | 1572篇 |
免费 | 121篇 |
专业分类
耳鼻咽喉 | 2篇 |
儿科学 | 21篇 |
妇产科学 | 20篇 |
基础医学 | 204篇 |
口腔科学 | 24篇 |
临床医学 | 172篇 |
内科学 | 328篇 |
皮肤病学 | 20篇 |
神经病学 | 138篇 |
特种医学 | 215篇 |
外科学 | 202篇 |
综合类 | 22篇 |
预防医学 | 146篇 |
眼科学 | 20篇 |
药学 | 81篇 |
中国医学 | 1篇 |
肿瘤学 | 77篇 |
出版年
2021年 | 23篇 |
2020年 | 21篇 |
2019年 | 23篇 |
2018年 | 24篇 |
2017年 | 21篇 |
2016年 | 18篇 |
2015年 | 25篇 |
2014年 | 41篇 |
2013年 | 40篇 |
2012年 | 78篇 |
2011年 | 72篇 |
2010年 | 25篇 |
2009年 | 40篇 |
2008年 | 58篇 |
2007年 | 60篇 |
2006年 | 48篇 |
2005年 | 57篇 |
2004年 | 50篇 |
2003年 | 61篇 |
2002年 | 48篇 |
2001年 | 44篇 |
2000年 | 40篇 |
1999年 | 42篇 |
1998年 | 14篇 |
1997年 | 14篇 |
1994年 | 14篇 |
1993年 | 13篇 |
1992年 | 42篇 |
1991年 | 44篇 |
1990年 | 41篇 |
1989年 | 45篇 |
1988年 | 36篇 |
1987年 | 45篇 |
1986年 | 41篇 |
1985年 | 36篇 |
1984年 | 20篇 |
1983年 | 20篇 |
1982年 | 16篇 |
1980年 | 14篇 |
1979年 | 18篇 |
1978年 | 17篇 |
1977年 | 18篇 |
1976年 | 17篇 |
1975年 | 15篇 |
1974年 | 16篇 |
1973年 | 14篇 |
1970年 | 14篇 |
1969年 | 19篇 |
1968年 | 13篇 |
1966年 | 13篇 |
排序方式: 共有1693条查询结果,搜索用时 15 毫秒
111.
The authors report the accuracy of mammographically guided fine-needle aspiration (FNA) for the diagnosis of nonpalpable breast lesions in a series of 71 patients. Each mammographically guided FNA was immediately followed by hookwire localization and open biopsy. Seven malignancies were identified cytologically, but three cancers were not detected in aspirates judged to be sufficient for diagnosis. In addition, 19 aspirates were reported to be insufficient, and 4 of these were obtained from lesions histologically proven to be adenocarcinoma. Although no false-positive diagnoses were encountered, the technique demonstrated a sensitivity of 78% and a diagnostic accuracy of 94% for adequate specimens. In this study, mammographically guided FNA was insufficiently sensitive to replace open biopsy for the diagnosis of nonpalpable breast lesions. 相似文献
112.
113.
Meniscal injuries: detection using MR imaging 总被引:15,自引:0,他引:15
Reicher MA; Hartzman S; Duckwiler GR; Bassett LW; Anderson LJ; Gold RH 《Radiology》1986,159(3):753-757
Both retrospective and blinded analyses of thin-section, high-resolution magnetic resonance (MR) images of the knee joint, produced using a solenoid surface coil, indicate that MR imaging is an effective technique for evaluating meniscal injuries. Images of 49 patients were evaluated, and the results were correlated with those of subsequent arthroscopy. A grading scale was developed to rate the index of suspicion of a meniscal tear based on the MR images. Overall, approximately 80% of menisci rated grade 4 (definite tear) or 3 (probable tear) were found to have corresponding tears at arthroscopy. In many other patients with a grade 4 or 3 meniscus in whom a corresponding tear was not found arthroscopically, meniscal tears at other sites or other abnormalities were correctly diagnosed using MR. A majority of the false-positive MR images involved the posterior horns of the menisci, the sites of most false-negative arthroscopic diagnoses. The predictive value of a negative MR image was almost 100%. Even in patients with moderate-to-large effusions, the menisci were accurately evaluated. The results imply that MR imaging is useful in the preoperative evaluation of suspected meniscal tears. 相似文献
114.
We conducted a telephone interview of all 207 accredited diagnostic radiology residency training programs listed in the American Medical Association's Directory of Graduate Medical Education Programs. Resident training in mammography was offered in 206 programs, and 35% of the programs had initiated this training within the past 3 years. Residents had an assigned block of time to do mammography in 84% of the programs. Of the 206 programs, 40% had rotations devoted exclusively to mammography, with 82% of the exclusive rotations lasting from 4 to 8 weeks. Residents were performing localization procedures in 91% of the programs and dictating cases in 81%. A distinction was made between screening and diagnostic examinations by 35% of the training institutions, at least in terms of the fee for the examination. Radiologists who devoted at least half of their practice to mammography taught in 52% of the programs. The American College of Radiology has granted accreditation in mammography to 29% of the programs. Although almost all accredited residency training programs offer training in mammography, there are some deficiencies in this training. More residents need to gain the experience of dictating mammography reports and need to learn about the distinctions between screening and diagnostic mammography. Despite the anticipated deluge of screening examinations in the next decade, there were only 17 fellowships that included at least 6 months of mammography identified in 15 (7%) of the institutions; only 11 of these were full-time 1-year breast imaging fellowships. 相似文献
115.
Olfactory deficits in schizophrenia and chromosome 5 总被引:1,自引:0,他引:1
116.
117.
R B Lufkin J Votruba M Reicher L Bassett S D Smith W N Hanafee 《AJR. American journal of roentgenology》1986,146(2):409-412
A nonplanar solenoidal surface radiofrequency coil is used as a receiver with a conventional transmitter coil in a magnetic resonance imaging system. The improved signal-to-noise ratio, compared with that of conventional fixed saddle or solenoid receiver coils, permits higher resolution imaging and thinner image sections. In addition, the problem of signal dropoff that occurs in deep structures with planar and other noncircumferential surface coils is eliminated. Solenoid surface coils are particularly useful in imaging deep structures in anatomic regions that do not fit standard head and body coils, such as the neck, knees, and other smaller body parts. 相似文献
118.
119.
L L Seeger J T Ruszkowski L W Bassett S P Kay R D Kahmann H Ellman 《AJR. American journal of roentgenology》1987,148(1):83-91
The complex anatomy and the requirement to image in the peripheral magnetic field have made the shoulder difficult to examine with MR. However, the use of high-resolution scanning techniques and specialized surface coils has improved the quality of MR images obtained. Seventy-five scans of the shoulders of normal volunteers were correlated with multiplanar cryomicrosections of six cadaver shoulders to study the MR appearance of normal structures. MR was shown to provide excellent depiction of shoulder anatomy. 相似文献