全文获取类型
收费全文 | 15369篇 |
免费 | 1029篇 |
国内免费 | 100篇 |
专业分类
耳鼻咽喉 | 132篇 |
儿科学 | 330篇 |
妇产科学 | 880篇 |
基础医学 | 1949篇 |
口腔科学 | 313篇 |
临床医学 | 1758篇 |
内科学 | 3207篇 |
皮肤病学 | 288篇 |
神经病学 | 1150篇 |
特种医学 | 541篇 |
外科学 | 2004篇 |
综合类 | 315篇 |
一般理论 | 8篇 |
预防医学 | 814篇 |
眼科学 | 425篇 |
药学 | 1075篇 |
中国医学 | 128篇 |
肿瘤学 | 1181篇 |
出版年
2023年 | 69篇 |
2022年 | 203篇 |
2021年 | 365篇 |
2020年 | 162篇 |
2019年 | 320篇 |
2018年 | 439篇 |
2017年 | 262篇 |
2016年 | 303篇 |
2015年 | 454篇 |
2014年 | 558篇 |
2013年 | 778篇 |
2012年 | 1110篇 |
2011年 | 1187篇 |
2010年 | 762篇 |
2009年 | 624篇 |
2008年 | 879篇 |
2007年 | 879篇 |
2006年 | 835篇 |
2005年 | 805篇 |
2004年 | 748篇 |
2003年 | 660篇 |
2002年 | 637篇 |
2001年 | 571篇 |
2000年 | 538篇 |
1999年 | 389篇 |
1998年 | 139篇 |
1997年 | 114篇 |
1996年 | 104篇 |
1995年 | 90篇 |
1994年 | 81篇 |
1993年 | 70篇 |
1992年 | 185篇 |
1991年 | 155篇 |
1990年 | 117篇 |
1989年 | 120篇 |
1988年 | 112篇 |
1987年 | 86篇 |
1986年 | 78篇 |
1985年 | 66篇 |
1984年 | 49篇 |
1983年 | 37篇 |
1982年 | 31篇 |
1981年 | 25篇 |
1980年 | 22篇 |
1979年 | 44篇 |
1978年 | 29篇 |
1977年 | 24篇 |
1976年 | 21篇 |
1975年 | 27篇 |
1973年 | 25篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
12.
13.
骨巨细胞瘤的MRI诊断价值 总被引:10,自引:0,他引:10
目的探讨骨巨细胞瘤的MRI表现特点及其病理基础。资料与方法搜集经手术病理证实的12例骨巨细胞瘤患者资料,分析其MRI征象并与病理结果对照。结果T1WI上肿瘤实体表现为低、等信号,T2WI上为不均匀高信号,Gd-DTPA增强扫描呈中度到明显强化。此外,MRI还可显示肿瘤内坏死、出血、含铁血黄素沉着等。结论MRI能够提供比较全面的影像学信息,可提高对骨巨细胞瘤诊断的准确性。 相似文献
14.
Huey-Juan Lin Poh-Shiow Yeh Tsung-Chia Tsai Tain-Junn Cheng Dershin Ke Kao-Chang Lin Jih-Gong Ho Chia-Yu Chang 《Journal of clinical neuroscience》2007,14(1):17-21
Using a prospective hospital-based registry, 146 patients with transient ischaemic attack (TIA) were compared with 376 patients with minor first-ever ischaemic stroke with respect to the 3-month risk of subsequent vascular events, in order to clarify the distinctions between the disease entities. All patients were enrolled within 48 h of onset. The risk factor distribution for the two groups was comparable, except that the TIA patients had more previous TIAs. Large artery atherosclerosis (34%) and small vessel occlusion (32%) were the main aetiologies in the TIA group, whereas small vessel occlusion (49%) was the major cause in the stroke group. The 3-month risk of combined endpoints of stroke, myocardial infarction, and vascular death for TIA patients was higher than that for the minor stroke group (15.1% vs. 3.2%; hazard ratio 4.6, 95% confidence interval 2.3-9.3 in multivariate analysis). Large artery atherosclerosis and male sex were the other significant predictors. TIA may demand more urgent management than minor stroke. The fact that aetiology is a predictor, highlights the need for rapid diagnostic tests to establish pathogenesis. 相似文献
15.
C L Yu C Y Tsai S Y Hong C S Lue C C Chiu B N Chiang S H Han S R Wang 《Scandinavian journal of rheumatology》1991,20(1):8-15
Extracellular phospholipase A2 (PLA2) is a proinflammatory enzyme found especially in the inflammatory exudate to modulate blood flow to areas of antigen stimulation. In this study we found that PLA2 exerted a biphasic effect on the proliferation of phytohemagglutinin (PHA)-stimulated human mononuclear cells (PHA MNC). At low concentrations range from 0.001 to 1 U/ml, PLA2 enhanced the proliferation of PHA MNC (maximal increase was 37.0 +/- 5.67%). Conversely, at concentrations over 10 U/ml, PLA2 markedly suppressed the PHA-induced MNC proliferation (maximal decrease was 88.86 +/- 2.89%). PLA2 was non-toxic to lymphocytes after three days culture, unless the concentration was higher than 100 U/ml. The membrane polarization of PHA-stimulated lymphocytes was also increased by PLA2 at a low concentration. In addition, PLA2 displayed a similar effect on the proliferation of streptokinase-streptodornase (SK/SD) or allogeneic cell stimulated lymphocytes. The change of lymphocyte proliferation by PLA2, was parallel to the change of percentage of helper T cells. Furthermore--a CD4-rich population was proved more susceptible to PLA2 effect than a CD8-rich population. Para-bromophenacyl bromide (pBPB), an irreversible inhibitor of PLA2, abrogated the biphasic effect of PLA2 on PHA MNC proliferation. These results suggest that PLA2 plays a regulatory role on immune reactions by modulating the percentage of helper T cells. 相似文献
16.
Using the polymerase chain reaction (PCR)-based single strand conformation polymorphism (SSCP) analysis, we have examined the highly conserved regions of the p53 gene in 58 biopsy samples of head and neck tumors. Mutations were found in 13/58 (23%) tumor specimens, but not in 6 normal tissues. Ten of 13 mutations were due to single base changes and the remaining 3 were 1- or 8-base deletion mutants. These mutations were clustered in exons 5 and 7 and resulted in amino acid changes. Our results seem to indicate that mutations in the p53 gene contribute to a significant number of cases of the head and neck tumors including 20% of nasopharyngeal carcinoma biopsies. The relationship of Epstein-Barr virus or human papillomavirus and p53 gene mutations in this group of cancers was also analyzed and discussed. 相似文献
17.
Hum. Reprod., 19, 23132318, 2004 The following mistake 相似文献
18.
19.
20.
Hsin-Yi Chen Mei-Ling Huang Yi-Yu Tsai Por-Tying Hung 《Optometry and vision science》2007,84(7):640-646
PURPOSE: To study the diagnostic ability of scanning laser polarimetry with variable corneal compensation (GDx VCC) for early glaucomatous (EG) eyes and glaucoma-suspect (GS) eyes in a Taiwan Chinese population. METHODS: This prospective cross-sectional study included 82 EG eyes (mean deviation, MD: -3.32 +/- 2.20 dB), 45 GS eyes (MD: -2.43 +/- 2.16 dB), and 62 normal eyes. Retinal nerve fiber layer thickness of each subject was measured using GDx VCC and Humphrey Field Analyzer visual field testing. Measured GDx VCC parameters were compared among groups. The area under the receiver operating characteristic (AROC) curve of each parameter was used to differentiate normal from EG eyes or GS eyes. The correlation between MD and each parameter was also evaluated. RESULTS: For both normal versus EG and normal versus GS, the largest AROC values were for nerve fiber indicator, superior average thickness, and inferior average thickness. There was no significant correlation between MD and GDx-VCC-measured parameters either in EG or GS eyes. CONCLUSIONS: GDx VCC shows only moderate ability to distinguish normal eyes from eyes with early glaucoma. However, its diagnostic role in eyes with suspicious discs and normal visual fields is uncertain at this moment in the Taiwan Chinese population. Further studies are needed to address this issue. 相似文献