全文获取类型
收费全文 | 319967篇 |
免费 | 38475篇 |
国内免费 | 2768篇 |
专业分类
耳鼻咽喉 | 7430篇 |
儿科学 | 10288篇 |
妇产科学 | 6588篇 |
基础医学 | 27998篇 |
口腔科学 | 7000篇 |
临床医学 | 36254篇 |
内科学 | 84784篇 |
皮肤病学 | 11876篇 |
神经病学 | 28281篇 |
特种医学 | 10454篇 |
外国民族医学 | 1篇 |
外科学 | 60296篇 |
综合类 | 1052篇 |
现状与发展 | 72篇 |
一般理论 | 28篇 |
预防医学 | 27426篇 |
眼科学 | 7748篇 |
药学 | 14451篇 |
中国医学 | 740篇 |
肿瘤学 | 18443篇 |
出版年
2023年 | 5536篇 |
2022年 | 1795篇 |
2021年 | 5626篇 |
2020年 | 7331篇 |
2019年 | 5076篇 |
2018年 | 12304篇 |
2017年 | 10326篇 |
2016年 | 11474篇 |
2015年 | 11799篇 |
2014年 | 19214篇 |
2013年 | 21421篇 |
2012年 | 16014篇 |
2011年 | 16764篇 |
2010年 | 15754篇 |
2009年 | 18074篇 |
2008年 | 14971篇 |
2007年 | 13877篇 |
2006年 | 15922篇 |
2005年 | 12810篇 |
2004年 | 11486篇 |
2003年 | 9921篇 |
2002年 | 9612篇 |
2001年 | 8963篇 |
2000年 | 8886篇 |
1999年 | 7638篇 |
1998年 | 4375篇 |
1997年 | 3918篇 |
1996年 | 3806篇 |
1995年 | 3602篇 |
1994年 | 2285篇 |
1993年 | 1839篇 |
1992年 | 3607篇 |
1991年 | 3411篇 |
1990年 | 3055篇 |
1989年 | 2874篇 |
1988年 | 2631篇 |
1987年 | 2370篇 |
1986年 | 2450篇 |
1985年 | 2174篇 |
1984年 | 1610篇 |
1983年 | 1420篇 |
1979年 | 1529篇 |
1977年 | 1187篇 |
1975年 | 1172篇 |
1974年 | 1359篇 |
1973年 | 1408篇 |
1972年 | 1429篇 |
1971年 | 1290篇 |
1970年 | 1271篇 |
1969年 | 1163篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
992.
Ferenc Pongrácz Zoltán Bárdosi 《International journal of computer assisted radiology and surgery》2006,1(3):149-156
Purpose To develop an easy-to-use, dentition planning method which is based on three-dimensional (3D) computer planning technology to replace conventional plaster-cast occlusion planning techniques.
Methods The optimal dental occlusion is defined according to the condition of centric occlusion, i.e. after bringing occlusal surfaces of mandibular and opposing maxillary arches into identical 3D position. This identical position of occlusal surfaces represents the common reference frame for the 3D manipulation of all graphical elements. The planning procedure involves the following steps: (1) the optimal occlusal surface is approximated as triangle and localized both on the maxilla and mandible; (2) the original volumetric model is resampled according to the occlusal orientations; (3) the program reads in the models of ideal upper and lower dental arches from files, reshapes those to the patient anatomy and visualizes the local alignment on separate panels for mesiodistal and faciolingual inclinations. The final goal of the proposed method is to combine the requirements of functional and aesthetic designs and create an input for orthodontics, implantology and maxillofacial surgery.
Results In the present study the optimal dental occlusion is created by image resampling after bringing the occlusal surfaces of mandibular and opposing maxillary arches into identical 3D position. This identical position of occlusal surfaces represents the common reference frame for manipulation of all graphical elements.
Conclusions The proposed graphical environment was able to fit the elements of the ideal dentition curve to patient computed tomography under predefined centric occlusion. Rotation and scaling transformations of teeth were possible in the reformatted volumetric views about any of the axes of the teeth’s own reference space. 相似文献
993.
Maria José GaldOn Estrella Durá Yolanda Andreu Maite Ferrando Rafael Poveda José Vicente Bagán 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2006,102(1):40-46
OBJECTIVE: This study analyzes the differences in psychological variables and symptomatology between temporomandibular disorder diagnosis subgroups. STUDY DESIGN: The sample included 114 temporomandibular disorder patients that were evaluated in coping, distress, and temporomandibular characteristics. Diagnostic muscular (n = 58) and articular (n = 56) subgroups were compared in these variables through a MANCOVA. RESULTS: Muscular patients show a higher level of general distress, specifically in the anxiety and somatization subscales and a more active coping style, with a tendency of a minor use of humor and a higher number of parafunctional habits, specifically, biting nails, hangnails, and lips. CONCLUSION: We discuss the differences found in order to design the targets of the psychological intervention of temporomandibular patients. 相似文献
994.
AIM: The aim of this study was to quantify the flow-mediated dilatation (FMD) of brachial artery in asymptomatic members of families with familial combined hyperlipidemia (FCH) and to determine the relation between FMD and risk factors accompanying FCH. We also investigated the association between FMD and the intima-media thickness (IMT) of the common carotid artery. METHODS: Eighty-two members of 29 FCH families were divided into two groups: probands and hyperlipidemic first-degree relatives (HL) (n=47) and normolipidemic first-degree relatives (NL) (n=35). The control (C) groups, C-HL (n=20) and C-NL (n=20), consisted of sex- and age-matched healthy individuals. FMD was assessed in the brachial artery by measuring the change in brachial artery diameter in response to reactive hyperemia. RESULTS: Both hyperlipidemic subjects and their NL had significantly lower FMD (3.4+/-3% vs 6.3+/-2.8%, P<0.001, 5.2+/-2.3% vs 7.8+/-2.8%, P<0.01, respectively) compared to controls. In multivariate backward stepwise regression analysis, FMD in members of FCH families was independently associated with sex (P<0.001), age (P<0.01), C-peptide (P<0.05) and borderline with glycemia (P=0.052). FMD correlated inversely with IMT in all subjects of FCH families and in hyperlipidemic members. In multivariate backward stepwise regression analysis this relation remained independent (P<0.001, P<0.01, respectively). CONCLUSIONS: Members of FCH families showed impaired FMD, which was independently associated with markers of insulin resistance. FMD and IMT were independently associated in hyperlipidemic, but not in normolipidemic members of FCH families. 相似文献
995.
996.
Jocelyn M. Cottrell BS Marjolein C. H. van der Meulen PhD Joseph M. Lane MD Elizabeth R. Myers PhD 《HSS journal》2006,2(1):12-18
The clinical goal of spinal fusion is to reduce motion and the associated pain. Therefore, measuring motion under loading
is critical. The purpose of this study was to validate four-point bending as a means to mechanically evaluate simulated fusions
in dog and rabbit spines. We hypothesized that this method would be more sensitive than manual palpation and would be able
to distinguish unilateral vs bilateral fusion. Spines from four mixed breed dogs and four New Zealand white rabbits were used
to simulate posterolateral fusion with polymethyl methacrylate as the fusion mass. We performed manual palpation and nondestructive
mechanical testing in four-point bending in four planes of motion: flexion, extension, and right and left bending. This testing
protocol was used for each specimen in three fusion modes: intact, unilateral, and bilateral fusion. Under manual palpation,
all intact spines were rated as not fused, and all unilateral and bilateral simulated fusions were rated as fused. In four-point
bending, dog spines were significantly stiffer after unilateral fusion compared with intact in all directions. Additionally,
rabbit spines were stiffer in flexion and left bending after unilateral fusion. All specimens exhibited significant differences
between intact and bilateral fusion except the rabbit in extension. For unilateral vs bilateral fusion, significant differences
were present for right bending in the dog model and for flexion in the rabbit. Unilateral fusion can provide enough stability
to constitute a fused grade by manual palpation but may not provide structural stiffness comparable to bilateral fusion. 相似文献
997.
Neuroimaging in Pineal Tumors 总被引:4,自引:0,他引:4
F Reis MD AV Faria MD PhD VA Zanardi MD PhD JR Menezes MD F Cendes MD PhD LS Queiroz MD PhD 《Journal of neuroimaging》2006,16(1):52-58
BACKGROUND AND PURPOSE: The authors report radiological findings in 11 tumors in the pineal region, which were histologically diagnosed as germinomas, pineocytomas pineoblastomas, ependymomas, teratomas, and astrocytomas. METHODS: Computed tomography (CT) was performed in seven patients and magnetic resonance imaging (MRI) was performed in all patients. RESULTS: CT showed a solid or solid/cystic mass with variable contrast enhancement. MRI showed a heterogeneous mass, with hypointense signal on T1 and iso/hyperintense signal on T2-weighted images (WI) and gadolinium enhancement. Extension to adjacent structures occurred in five patients and spread through the cerebral spinal fluid (CSF) in two. CONCLUSIONS: Pineal region tumors have no pathognomonic imaging pattern. MRI and CT are complementary in diagnosis and are important to determine localization, extension, and meningeal spread. 相似文献
998.
999.
Edouard J. Trabulsi MD William G. Merriam MD Leonard G. Gomella MD 《Current Prostate Reports》2006,4(2):67-72
Correct staging of prostate cancer at initial diagnosis, as well as accurate staging and tumor localization with biochemical recurrence, remains generally inaccurate with current imaging techniques. Newer modalities are being investigated to accurately identify patients with prostate cancer at different stages of disease. Identification of locally recurrent disease or distant metastasis at the time of biochemical failure after local therapy will help guide treatment options and avoid potentially toxic salvage therapies in patients who will not benefit. A review of prostate cancer imaging literature over the past 12 months was performed to identify emerging imaging modalities that may be beneficial in the management of prostate cancer. Enhanced transrectal ultrasonography modalities, including ultrasound contrast agents, color and power Doppler, and elastrography, have demonstrated incremental benefit when combined with standard grayscale ultrasonography to accurately target and diagnose prostate cancer. Endorectal MRI, with contrast enhancement and spectroscopic imaging, shows promise in the initial staging of prostate cancer prior to local therapy. The use of positron-emission tomography scan for prostate cancer remains to be defined, but may help delineate the site of recurrence with biochemical failure after local therapy. Several new imaging modalities show promise for the evaluation of the patient with prostate cancer. Enhanced ultrasonography techniques may prove to be more accurate in diagnosing prostate cancer over standard gray-scale ultrasonography. Accumulating evidence supports the use of endorectal MRI and spectroscopy to help treatment planning with either surgical or radiotherapeutic approaches. Although intriguing, the available data for positron-emission tomography in prostate cancer remains too shallow to advocate routine use. 相似文献
1000.
External beam radiation therapy (EBRT) and brachytherapy are common treatment modalities for newly diagnosed prostate cancer. What complications can patients and physicians expect following these therapies? How are these conditions diagnosed and treated? In this article, we examine several of the most common acute and delayed complications of radiation therapy for prostate cancer. In addition, we discuss appropriate follow-up diagnostics for these patients and our suggestions for management of the main complications that may develop. 相似文献