全文获取类型
收费全文 | 47887篇 |
免费 | 3310篇 |
国内免费 | 1358篇 |
专业分类
耳鼻咽喉 | 374篇 |
儿科学 | 1658篇 |
妇产科学 | 1662篇 |
基础医学 | 5092篇 |
口腔科学 | 1144篇 |
临床医学 | 7432篇 |
内科学 | 5816篇 |
皮肤病学 | 596篇 |
神经病学 | 2169篇 |
特种医学 | 2272篇 |
外国民族医学 | 20篇 |
外科学 | 3326篇 |
综合类 | 10275篇 |
现状与发展 | 11篇 |
一般理论 | 2篇 |
预防医学 | 2987篇 |
眼科学 | 970篇 |
药学 | 2031篇 |
84篇 | |
中国医学 | 1183篇 |
肿瘤学 | 3451篇 |
出版年
2024年 | 125篇 |
2023年 | 640篇 |
2022年 | 1318篇 |
2021年 | 1844篇 |
2020年 | 1985篇 |
2019年 | 1431篇 |
2018年 | 1384篇 |
2017年 | 1430篇 |
2016年 | 1782篇 |
2015年 | 1563篇 |
2014年 | 2938篇 |
2013年 | 3074篇 |
2012年 | 2666篇 |
2011年 | 2878篇 |
2010年 | 2342篇 |
2009年 | 2304篇 |
2008年 | 2224篇 |
2007年 | 2489篇 |
2006年 | 2345篇 |
2005年 | 2059篇 |
2004年 | 1847篇 |
2003年 | 1631篇 |
2002年 | 1334篇 |
2001年 | 1218篇 |
2000年 | 920篇 |
1999年 | 783篇 |
1998年 | 661篇 |
1997年 | 660篇 |
1996年 | 599篇 |
1995年 | 528篇 |
1994年 | 470篇 |
1993年 | 426篇 |
1992年 | 343篇 |
1991年 | 326篇 |
1990年 | 289篇 |
1989年 | 232篇 |
1988年 | 273篇 |
1987年 | 221篇 |
1986年 | 176篇 |
1985年 | 174篇 |
1984年 | 109篇 |
1983年 | 72篇 |
1982年 | 85篇 |
1981年 | 74篇 |
1980年 | 73篇 |
1979年 | 62篇 |
1978年 | 40篇 |
1977年 | 23篇 |
1976年 | 26篇 |
1975年 | 27篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Christoph Scherfler MD Johannes Schwarz MD PhD Angelo Antonini MD PhD Donald Grosset MD Francesc Valldeoriola MD PhD Kenneth Marek MD Wolfgang Oertel MD Eduardo Tolosa MD PhD Andrew J. Lees MD Werner Poewe MD 《Movement disorders》2007,22(9):1229-1238
The diagnosis of idiopathic Parkinson's disease (PD) can be achieved with high degrees of accuracy in cases with full expression of classical clinical features. However, diagnostic uncertainty remains in early disease with subtle or ambiguous signs. Functional imaging has been suggested to increase the diagnostic yield in parkinsonian syndromes with uncertain clinical classification. Loss of striatal dopamine nerve terminal function, a hallmark of neurodegenerative Parkinsonism, is strongly related to decreases of dopamine transporter (DAT) density, which can be measured by single photon emission computed tomography (SPECT). The use of DAT‐SPECT facilitates the differential diagnosis in patients with isolated tremor symptoms not fulfilling PD or essential tremor criteria, drug‐induced, psychogenic and vascular Parkinsonism as well as dementia when associated with Parkinsonism. This review addresses the value of DAT‐SPECT in early differential diagnosis, and its potential as a screening tool for subjects at risk of developing PD as well as issues around the assessment of disease progression. © 2007 Movement Disorder Society 相似文献
62.
Gavin F. Bridgman 《Clinical & experimental optometry》1989,72(3):91-93
An infant rod monochromat was diagnosed and was then treated with the Younger PLS 550 lens. The comparison in use of PLS 550 and a neutral density lens confirmed the presence of cone dysfunction. The use of this lens takes advantage of the spectral shift in luminosity between rods and cones. Younger PLS 550 and PLS 530 tints are used for the relief of photophobia according to prevailing brightness. This paper discusses patient management with the use of these lenses and some characteristics of the vision of a rod monochromat. 相似文献
63.
M. Baekelandt M. Kockx F. Wesling & J. Gerris 《International journal of gynecological cancer》1993,3(2):65-71
An extensive review of the currently available literature on primary fallopian tube carcinoma is presented. The role of vaginal ultrasonography and the importance of an aggressive evaluation of every tubal deformity is stressed. A staging system which takes into account recent data on the biology of this malignancy is proposed. We emphasize the largely underestimated importance of early lymphatic spread of this disease, necessitating a thorough staging laparotomy with pelvic and para-aortic lymph node sampling in the apparent early stages. The need for adjuvant treatment is obvious, but until now no firm data exist as to what the optimal strategy should be. We recommend that until more representative studies are available, ovarian carcinoma protocols should be used in clinical practice. 相似文献
64.
Ultraviolet Laser-Induced Fluorescence Spectroscopy Diagnosis of Human Stomach Malignant Tissues 总被引:2,自引:0,他引:2
To evaluate the potential of laser-induced autofluorescence spectroscopy for the detection of premalignant lesions of human
stomach, fluorescence properties of stomach tissues have been investigated in vitro and in vivo. A specially made optical
fibre probe and the multichannel fluorescence collection system have been used successfully in our research.
Paper received 26 June 1997; accepted in revised form 31 October 1997. 相似文献
65.
66.
本文对西宁地区新生儿缺氧缺血性脑病(HIE)颅脑超声诊断分析脑缺氧缺血产生的原因、脑实质损伤程度及预后评估。提出对围产期窒息导致脑缺血性损害的预防措施。 相似文献
67.
68.
P. Satishchandra † A. Shivaramakrishana V. G. Kaliaperumal† Bruce S. Schoenberg‡ 《Epilepsia》1988,29(1):52-56
"Hot water epilepsy" (HWE), precipitated by a bath or shower in hot water, has been described infrequently in the literature. We report 279 cases of HWE that were seen between 1980 to 1983 in Bangalore, South India. We found HWE to be more common in children, with cases more frequent among male than female patients (2.6:1). Complex partial seizures constituted the main clinical presentation (67.0%); HWE accounted for 4.4% of all complex partial seizures and generalize tonic-clonic seizures seen at our center during the 1980-1983 period. Although prognosis seems favorable 25.4% of our patients developed nonreflex epilepsy within 1-3 years. They were managed with antiepileptic drugs and the use of lukewarm water for bathing. 相似文献
69.
Michael S. Watson W. Roy Breg John C. Hobbins Maurice J. Mahoney 《American journal of medical genetics. Part A》1984,19(4):805-813
Cytogenetic studies on fetal blood cells obtained at 18–25 weeks gestation have provided information for decision making in 25 cases identified as being at high risk of having an abnormal fetus. In particular, in the 21 cases studied to consider the possibility of true mosaicism, confirmation in fetal blood was obtained in three, one of which presented as a pseudomosaic on the original amniotic fluid cell study. Fetal blood was also informative in two cases (one positive and the other negative) in which a diagnosis of the fragile X syndrome was being considered. Furthermore, when high risk pregnancies presented late in gestation (21–24 weeks), these methods allowed for a rapid cytogenetic diagnosis. The procedure has proved useful in most of these cases since the couples involved had indicated that they would probably have terminated the pregnancy without the reassurance of normal fetal lymphocyte studies. Since the technique carries a much higher risk of pregnancy loss than does amniocentesis, its use should only be considered when there are compelling indications. 相似文献
70.
Classification of Breast Masses Using Selected Shape,Edge-sharpness,and Texture Features with Linear and Kernel-based Classifiers 总被引:2,自引:0,他引:2
Breast masses due to benign disease and malignant tumors related to breast cancer differ in terms of shape, edge-sharpness, and texture characteristics. In this study, we evaluate a set of 22 features including 5 shape factors, 3 edge-sharpness measures, and 14 texture features computed from 111 regions in mammograms, with 46 regions related to malignant tumors and 65 to benign masses. Feature selection is performed by a genetic algorithm based on several criteria, such as alignment of the kernel with the target function, class separability, and normalized distance. Fisher's linear discriminant analysis, the support vector machine (SVM), and our strict two-surface proximal (S2SP) classifier, as well as their corresponding kernel-based nonlinear versions, are used in the classification task with the selected features. The nonlinear classification performance of kernel Fisher's discriminant analysis, SVM, and S2SP, with the Gaussian kernel, reached 0.95 in terms of the area under the receiver operating characteristics curve. The results indicate that improvement in classification accuracy may be gained by using selected combinations of shape, edge-sharpness, and texture features. 相似文献