全文获取类型
收费全文 | 2577篇 |
免费 | 161篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 26篇 |
儿科学 | 72篇 |
妇产科学 | 36篇 |
基础医学 | 294篇 |
口腔科学 | 31篇 |
临床医学 | 216篇 |
内科学 | 569篇 |
皮肤病学 | 27篇 |
神经病学 | 194篇 |
特种医学 | 81篇 |
外科学 | 294篇 |
综合类 | 90篇 |
一般理论 | 4篇 |
预防医学 | 178篇 |
眼科学 | 164篇 |
药学 | 162篇 |
中国医学 | 7篇 |
肿瘤学 | 328篇 |
出版年
2023年 | 14篇 |
2022年 | 18篇 |
2021年 | 62篇 |
2020年 | 33篇 |
2019年 | 56篇 |
2018年 | 50篇 |
2017年 | 55篇 |
2016年 | 44篇 |
2015年 | 53篇 |
2014年 | 83篇 |
2013年 | 120篇 |
2012年 | 130篇 |
2011年 | 170篇 |
2010年 | 92篇 |
2009年 | 86篇 |
2008年 | 127篇 |
2007年 | 149篇 |
2006年 | 119篇 |
2005年 | 145篇 |
2004年 | 141篇 |
2003年 | 133篇 |
2002年 | 107篇 |
2001年 | 119篇 |
2000年 | 73篇 |
1999年 | 58篇 |
1998年 | 34篇 |
1997年 | 42篇 |
1996年 | 37篇 |
1995年 | 19篇 |
1994年 | 33篇 |
1993年 | 21篇 |
1992年 | 34篇 |
1991年 | 37篇 |
1990年 | 12篇 |
1989年 | 31篇 |
1988年 | 35篇 |
1987年 | 24篇 |
1986年 | 29篇 |
1985年 | 19篇 |
1984年 | 17篇 |
1983年 | 9篇 |
1982年 | 12篇 |
1981年 | 16篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 8篇 |
1977年 | 7篇 |
1975年 | 5篇 |
1970年 | 5篇 |
1965年 | 3篇 |
排序方式: 共有2773条查询结果,搜索用时 0 毫秒
91.
92.
Yuen Ling Elaine Au Woon Sing Raymond Wong Mo Yin Mok Ho Yin Chung Eric Chan Chak Sing Lau 《Clinical rheumatology》2014,33(8):1127-1134
Recently, the Ankylosing Spondylitis Disease Activity Score (ASDAS), a new index, has been shown to be validated and highly discriminatory in assessing ankylosing spondylitis (AS) disease activity. This study is to evaluate the performance of ASDAS in a local Chinese cohort of AS in a cross-sectional setting and to compare it with the existing instrument, the Bath Ankylosing Spondylitis Disease Activity Index (BASDAI). Consecutive patients with AS were recruited from a local rheumatology clinic. Data, including BASDAI, Bath Ankylosing Spondylitis Functional Index (BASFI), Visual Analogue Scale (VAS) for spinal pain, and patient and physician global assessments were gathered during clinic visit. Inflammatory markers, including erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and high-sensitivity (hs)-CRP were collected. ASDAS was calculated accordingly. The discriminatory capacity of BASDAI and ASDAS was compared by: (1) standardized mean difference statistics, (2) R 2 in linear regressions, and (3) area under receiver operating characteristic curve (AUC) in logistic regression models. Both ASDAS and BASDAI showed satisfactory predictive value on disease activity with reference to patient and physician global assessment. R 2 in linear regression models ranged from 0.6–0.7. Both indices also demonstrated good discriminatory capacity as evidenced by a relatively high AUC (> 0.8) under the logistic regression models using either patient or physician global assessment score ≥4 and <4 as cut off of high and low disease activity status, respectively. Although we could not demonstrate significant differences in the performance between them, subgroup analysis suggested better discriminatory ability of ASDAS in the high inflammatory marker subgroup. ASDAS and BASDAI showed similarly good performance in a cross-sectional setting in a local Chinese AS cohort. ASDAS performed better in subgroup with raised inflammatory markers. 相似文献
93.
94.
Audoin B Ranjeva JP Au Duong MV Ibarrola D Malikova I Confort-Gouny S Soulier E Viout P Ali-Chérif A Pelletier J Cozzone PJ 《Journal of magnetic resonance imaging : JMRI》2004,20(5):765-771
PURPOSE: To determine whether voxel-based analysis of magnetization transfer ratio (MTR) maps can provide evidence of a coherent pattern of gray matter (GM) macroscopic and microscopic tissue damage in patients at the earliest stage of multiple sclerosis (MS). MATERIALS AND METHODS: We acquired GM MTR maps in 18 patients with clinically isolated syndrome suggestive of MS (CISSMS), and 18 sex- and age-matched healthy controls. We evaluated the clinical status of the patients using the MS functional composite score and the expanded disability status scale. A two-sample t-test (P <0.0001, k=20, uncorrected for height threshold) was used to compare GM MTR maps from patients and controls on a voxel-by-voxel basis. We then extracted data from regions with t-values above the statistical threshold to verify the significance of differences using a nonparametric Mann-Whitney U-test. RESULTS: A between-groups comparison of GM maps revealed large abnormalities in the basal ganglia, including the bilateral thalamus, bilateral lenticular nucleus, bilateral head of caudate, and protuberance, and smaller abnormalities in the right insula, right BA 4, and left BA 40. The MTR measured in the left caudate and right insula was inversely correlated with duration following the first clinical event. CONCLUSION: These results suggest that although MS is a multifocal demyelinating disease that affects white matter (WM), a pattern of tissue damage is present inside the GM involving predominantly basal ganglia at the earliest stage of the disease. 相似文献
95.
96.
K F Leung W Y Au A Y Chan L C Chan J S Waye D H Chui S K Ma 《Clinical and laboratory haematology》2001,23(1):53-55
A Chinese family with concurrent hereditary spherocytosis (HS) and haemoglobin (Hb) Q-Thailand is described. The Hb Q-Thailand mutation was found on the remaining alpha1 globin gene on a chromosome 16 containing the (-alpha 4.2) deletion. Active haemolysis in members of this family is segregated with the HS phenotype, and the Hb Q-Thailand in the heterozygous state does not seem to show any modulating effect on HS. 相似文献
97.
Arthur K. Au MD Masashi J. Rotte Robert J. GrzybowskiBon S. Ku MD MPP J. Matthew Fields 《The American journal of emergency medicine》2012
Study Objectives
Obtaining intravenous (IV) access in the emergency department (ED) can be especially challenging, and physicians often resort to placement of central venous catheters (CVCs). Use of ultrasound-guided peripheral IV catheters (USGPIVs) can prevent many “unnecessary” CVCs, but the true impact of USGPIVs has never been quantified. This study set out to determine the reduction in CVCs by USGPIV placement.Methods
This was a prospective, observational study conducted in 2 urban EDs. Patients who were to undergo placement of a CVC due to inability to establish IV access by other methods were enrolled. Ultrasound-trained physicians then attempted USGPIV placement. Patients were followed up for up to 7 days to assess for CVC placement and related complications.Results
One hundred patients were enrolled and underwent USGPIV placement. Ultrasound-guided peripheral IV catheters were initially successfully placed in all patients but failed in 12 patients (12.0%; 95 confidence interval [CI], 7.0%-19.8%) before ED disposition, resulting in 4 central lines, 7 repeated USGPIVs, and 1 patient requiring no further intervention. Through the inpatient follow-up period, another 11 patients underwent CVC placement, resulting in a total of 15 CVCs (15.0%; 95 CI, 9.3%-23.3%) placed. Of the 15 patients who did receive a CVC, 1 patient developed a catheter-related infection, resulting in a 6.7% (95 CI, 1.2%-29.8%) complication rate.Conclusion
Ultrasound prevented the need for CVC placement in 85% of patients with difficult IV access. This suggests that USGPIVs have the potential to reduce morbidity in this patient population. 相似文献98.
99.
The generation and characterization of a cell line derived from a sporadic renal angiomyolipoma: use of telomerase to obtain stable populations of cells from benign neoplasms 下载免费PDF全文
Arbiser JL Yeung R Weiss SW Arbiser ZK Amin MB Cohen C Frank D Mahajan S Herron GS Yang J Onda H Zhang HB Bai X Uhlmann E Loehr A Northrup H Au P Davis I Fisher DE Gutmann DH 《The American journal of pathology》2001,159(2):483-491
Angiomyolipomas are benign tumors of the kidney derived from putative perivascular epithelioid cells, that may undergo differentiation into cells with features of melanocytes, smooth muscle, and fat. To gain further insight into angiomyolipomas, we have generated the first human angiomyolipoma cell line by sequential introduction of SV40 large T antigen and human telomerase into human angiomyolipoma cells. These cells show phenotypic characteristics of angiomyolipomas, namely differentiation markers of smooth muscle (smooth muscle actin), adipose tissue (peroxisome proliferator-activator receptor gamma, PPARgamma), and melanocytes (microophthalmia, MITF), thus demonstrating that a single cell type can exhibit all of these phenotypes. These cells should serve as a valuable tool to elucidate signal transduction pathways underlying renal angiomyolipomas. 相似文献
100.