全文获取类型
收费全文 | 1990篇 |
免费 | 220篇 |
国内免费 | 28篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 153篇 |
妇产科学 | 27篇 |
基础医学 | 252篇 |
口腔科学 | 92篇 |
临床医学 | 215篇 |
内科学 | 386篇 |
皮肤病学 | 60篇 |
神经病学 | 83篇 |
特种医学 | 237篇 |
外科学 | 295篇 |
综合类 | 59篇 |
一般理论 | 3篇 |
预防医学 | 125篇 |
眼科学 | 59篇 |
药学 | 70篇 |
中国医学 | 2篇 |
肿瘤学 | 114篇 |
出版年
2023年 | 16篇 |
2022年 | 9篇 |
2021年 | 26篇 |
2020年 | 20篇 |
2019年 | 22篇 |
2018年 | 54篇 |
2017年 | 56篇 |
2016年 | 51篇 |
2015年 | 76篇 |
2014年 | 97篇 |
2013年 | 124篇 |
2012年 | 75篇 |
2011年 | 66篇 |
2010年 | 99篇 |
2009年 | 114篇 |
2008年 | 50篇 |
2007年 | 69篇 |
2006年 | 62篇 |
2005年 | 48篇 |
2004年 | 41篇 |
2003年 | 26篇 |
2002年 | 30篇 |
2001年 | 29篇 |
2000年 | 25篇 |
1999年 | 31篇 |
1998年 | 105篇 |
1997年 | 92篇 |
1996年 | 101篇 |
1995年 | 70篇 |
1994年 | 80篇 |
1993年 | 45篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 23篇 |
1989年 | 37篇 |
1988年 | 43篇 |
1987年 | 31篇 |
1986年 | 38篇 |
1985年 | 33篇 |
1984年 | 13篇 |
1983年 | 13篇 |
1982年 | 21篇 |
1981年 | 16篇 |
1980年 | 16篇 |
1978年 | 8篇 |
1977年 | 10篇 |
1976年 | 13篇 |
1975年 | 9篇 |
1971年 | 7篇 |
1966年 | 6篇 |
排序方式: 共有2238条查询结果,搜索用时 15 毫秒
11.
AM Manganoni† C Farisoglio† G Tucci† F Facchetti‡ PG Calzavara Pinton† 《Journal of the European Academy of Dermatology and Venereology》2007,21(10):1333-1336
BACKGROUND: Development of more than one primary melanoma in a patient is a relatively uncommon but well-recognized phenomenon. Its frequency has ranged from 1.2% to 8.2% in several series. This subgroup of patients with multiple primary lesions has not been characterized sufficiently. We report the experience of the Melanoma Unit of University Hospital Spedali Civili of Brescia, Italy. METHOD: Study subjects were drawn from 1240 patients with histologically confirmed melanoma, including melanoma in situ. From this group, multiple melanomas developed in 47 patients (3.79%). Every one of our patients has been taught to perform self-examination of the skin to detect suspicious pigmented lesions. RESULTS: Of the 47 patients described in this study, 38 had two primary melanomas, 7 had three melanomas and 2 had 5 and 10 melanomas, respectively. Mean age at first diagnosis was 46.2 years. The majority of subsequent melanomas (74.5%) were removed within 5 years of the initial operation. Synchronous lesions were found in 10 patients. In male patients, the lesion appeared most frequently on the trunk; in female patients, melanoma appeared mostly on the lower extremities. The second primary melanomas developed in the same anatomic region from the first in 53.2% of our patients. The proportion of in situ to invasive melanomas was greater for the second melanomas compared with the first melanomas. Regarding invasive melanomas, the mean thickness of the first melanomas was 1.31 mm compared with 0.66 mm for the second ones. Dividing patients into two groups, of more and less than 50, it is highlighted that in older patients synchronous lesions appear more frequently (36.4% vs. 8.0%); the median time interval between sequential melanomas is longer (84 vs. 63.7 months); and the ratio between the primary and secondary melanoma mean thickness is lower (1.21 : 1.08 vs. 1.43 : 0.63 mm). CONCLUSIONS: The study confirms that second primary melanoma is usually thinner than the first lesion, and it is more common in the same region of the body as the initial melanoma. The highest risk for a second melanoma is during the first 5 years, but a much longer time interval of 28 years is possible. Continued medical follow-up with complete skin examinations seems prudent, but it is very important to promote self-skin evaluation in patients to detect not only metastases but also subsequent primary melanomas in their earliest phases. 相似文献
12.
MASATO FUKUDA MD AKINOBU HATA MD SHIN-ICHI NIWA MD KEN-ICHI HIRAMATSU MD MASAFUMI YOKOKOJI MD SEIKI HAYASHIDA AM KENJI ITOH DENG KAZUYUKI NAKAGOME MD AKIRA IWANAMI MD 《Psychiatry and clinical neurosciences》1996,50(2):85-88
Abstract A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event-related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was 'repressed'. Event-related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature. 相似文献
13.
D J Bergin C D McCord T Berger H Friedberg W Waterhouse 《The British journal of ophthalmology》1988,72(11):863-867
Blepharochalasis is an uncommon disorder distinguished by recurrent episodes of eyelid oedema in young patients. A hypertrophic form, manifested as fat herniation, and an atrophic form, manifested as fat atrophy, have been described. Ptosis with excellent levator function, laxity of the lateral canthal structures with rounding of the lateral canthal angle, nasal fat pad atrophy, and redundant eyelid skin develop after many episodes of eyelid swelling. Fine wrinkling, atrophy, and telangiectasias characterise the excess eyelid skin. We describe four cases of this syndrome in which external levator aponeurosis tuck, blepharoplasty, lateral canthoplasty, and dermis fat grafts were used to correct atrophic blepharochalasis after the syndrome had run its course. 相似文献
14.
15.
16.
17.
18.
Short-Ti inversion-recovery pulse sequence: analysis and initial experience in cancer imaging 总被引:2,自引:0,他引:2
Inversion recovery (IR), commonly considered a pulse sequence capable of producing T1-weighted images with excellent display of normal anatomy, is versatile: The null point and peak time provide a useful, succinct summary of the properties of IR and its capacity for producing both T1- and T2-weighted images. Shortening of the inversion time (TI) and creation of a short-TI inversion-recovery (STIR) pulse sequence increases sensitivity to malignancy and other abnormalities by making the effects of prolonged T1 and T2 on signal intensity additive and by nulling the signal from fat. The authors examined over 300 patients with various malignancies and compared STIR images with T1- and T2-weighted images obtained at 0.5 T. In 43 cases, signal-difference-to-noise ratios (SD/Ns) were calculated between tumor, fat, and muscle. In general, STIR images demonstrated tumor as a conspicuously high-intensity area in a background of muted, discernible anatomic detail. The good contrast achieved with STIR sequences between tumor and fat (SD/N = 18.1) and tumor and muscle (SD/N = 12.9) consolidated into a single image the information contained separately on T1- and T2-weighted images, which facilitates efficient detection and localization of malignancy. 相似文献
19.
Rosenberg ZS; Jahss MH; Noto AM; Shereff MJ; Cheung Y; Frey CC; Norman A 《Radiology》1988,167(2):489-493
Computed tomography (CT) was performed in 42 patients with 49 clinically suspected tears of the posterior tibial tendon. Twenty-eight of the 49 suspected tears were subsequently surgically explored and repaired. Three patterns of tendon abnormalities were recognized on CT scans: type I-intact, hypertrophied, heterogeneous tendon; type II-attenuated tendon; and type III-absence of a portion of a tendon. Types I and II correlated with partial rupture seen during surgery, and type III correlated with complete rupture of the tendon. CT findings were accurate in 96% of the patients who underwent surgery. In four cases (14%), tendon rupture was seen on CT scans, but the extent of the injury was underestimated and the rupture was misclassified. Reactive periostitis of the distal tibia was seen in 71% of diseased tendons and may represent an important factor in the diagnosis of tendon rupture. 相似文献
20.