全文获取类型
收费全文 | 56290篇 |
免费 | 3110篇 |
国内免费 | 601篇 |
专业分类
耳鼻咽喉 | 985篇 |
儿科学 | 641篇 |
妇产科学 | 825篇 |
基础医学 | 9768篇 |
口腔科学 | 1356篇 |
临床医学 | 4894篇 |
内科学 | 10587篇 |
皮肤病学 | 1878篇 |
神经病学 | 3989篇 |
特种医学 | 2990篇 |
外科学 | 7479篇 |
综合类 | 218篇 |
现状与发展 | 1篇 |
一般理论 | 17篇 |
预防医学 | 2716篇 |
眼科学 | 1230篇 |
药学 | 4990篇 |
中国医学 | 624篇 |
肿瘤学 | 4813篇 |
出版年
2023年 | 429篇 |
2022年 | 1326篇 |
2021年 | 2057篇 |
2020年 | 986篇 |
2019年 | 1291篇 |
2018年 | 1667篇 |
2017年 | 1241篇 |
2016年 | 1758篇 |
2015年 | 2562篇 |
2014年 | 3062篇 |
2013年 | 3494篇 |
2012年 | 5314篇 |
2011年 | 4807篇 |
2010年 | 2805篇 |
2009年 | 2369篇 |
2008年 | 3419篇 |
2007年 | 3099篇 |
2006年 | 2655篇 |
2005年 | 2353篇 |
2004年 | 2025篇 |
2003年 | 1694篇 |
2002年 | 1439篇 |
2001年 | 1365篇 |
2000年 | 1265篇 |
1999年 | 908篇 |
1998年 | 371篇 |
1997年 | 259篇 |
1996年 | 212篇 |
1995年 | 187篇 |
1994年 | 153篇 |
1993年 | 137篇 |
1992年 | 335篇 |
1991年 | 317篇 |
1990年 | 282篇 |
1989年 | 262篇 |
1988年 | 255篇 |
1987年 | 250篇 |
1986年 | 178篇 |
1985年 | 169篇 |
1984年 | 123篇 |
1983年 | 115篇 |
1982年 | 60篇 |
1981年 | 61篇 |
1979年 | 81篇 |
1978年 | 68篇 |
1975年 | 50篇 |
1974年 | 60篇 |
1973年 | 51篇 |
1972年 | 50篇 |
1970年 | 49篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
Valve prosthesis distortion after cardiac compression in a patient who underwent transcatheter aortic valve implantation (TAVI) 下载免费PDF全文
Eun Kyoung Kim MD Seung Hyuk Choi MD PhD Pil Sang Song MD Sung‐Ji Park MD PhD 《Catheterization and cardiovascular interventions》2014,83(3):E165-E167
Transcatheter aortic valve implantation (TAVI) has been developed as an alternative to conventional aortic valve replacement for the treatment of symptomatic severe aortic stenosis in high‐risk patients. Nevertheless, TAVI has been associated with serious complications such as stroke, vascular injury, renal failure, and arrhythmia. Herein we describe a case of distortion of the Edward‐Sapien prosthesis (Edwards Lifesciences, USA), which was mounted on a balloon‐expandable stent, after chest compression for cardiac resuscitation in a patient who underwent TAVI for severe aortic stenosis. © 2012 Wiley Periodicals, Inc. 相似文献
992.
993.
994.
Sangrak Bae Kyu Won Lee Hyun Cheol Jeong Bong Hee Park Woong Jin Bae Yong Seok Lee Chang Hee Han Sung Hak Kang Sae Woong Kim 《Lower urinary tract symptoms.》2020,12(1):25-32
This study investigated the effects of a low‐frequency home‐based incontinence therapy device on quality of life (QoL) and urinary symptoms in women with urinary incontinence. From May 2017 to February 2018, 34 patients, aged ≥ 20 years, with involuntary urine leakage >2 times/week, were recruited to this study. Patients with severe pelvic organ prolapse, pregnancy, virgin status, and psychological problems were excluded. The incontinence home‐care device treatments were administered in 12‐minute sessions, twice daily for 8 weeks. Simultaneously, hyperthermic conditions of 35°C to 40°C and microvibrations were administered. All patients completed urinary incontinence questionnaires (King's Health Questionnaire [KHQ], Bristol Female Lower Urinary Tract Symptoms [BFLUTS] questionnaire, and the Overactive Bladder Symptom Score [OABSS]) before treatment, as well as 4 and 8 weeks into treatment. Changes in the questionnaire responses over time were compared. Two participants dropped out of the study and there was one screening failure, leaving 31 patients for analysis. After 4 weeks treatment, there were significant improvements in symptoms, such as role limitation, physical limitation, social limitation, personal relationship, emotion, sleep/energy, and severity measures. After 8 weeks treatment, almost all parameters on the KHQ revealed symptomatic improvement. On the BFLUTS, voiding times during activity, nocturia, urgency, urge incontinence, incontinence frequency, stress incontinence, volume leakage, strain to start, intermittency, reduced stream, acute retention, incomplete emptying, and stopping flow showed significant improvements. On the OABSS, almost all storage symptoms improved. Low‐frequency electrical stimulation devices were effective at improving urinary incontinence, which became evident as the duration of treatment increased. Improvement of urgency and frequency was more evident after treatment. 相似文献
995.
996.
997.
998.
Background: Exacerbation of COPD is a major risk factor for bad prognosis of COPD. A few plasma proteins have been discovered to associate with hospital admission due to exacerbation up to date. We tried to find new plasma biomarkers to predict the exacerbation of COPD. Methods: We examined the plasma of normal control (n = 8) and COPD stable (n = 8) and exacerbation (n = 8) using 2-Dimentional Electrophoresis. The differentially expressed protein spots were identified by MALDI-TOF. ELISA were performed for quantitative measurement of RARα in plasma from normal control (n = 37) and COPD (n = 35). Results: 17 proteins were differentially expressed in plasma between stable and exacerbation state in the subjects with COPD. Identification using MALDI-TOF showed that retinoic acid receptor alpha, ninein, isoform CRA_a, alpha-1 antitrypsin, fibrinogen gamma, tyrosyl-DNA phosphodiesterase 2, and T cell receptor delta chain were increased in exacerbation of COPD, while fibrin beta, Crystal Structure Of An Autoimmune Complex Between A Human Igm RF* And Igg1 Fc, transferrin, serpin peptidase inhibitor member 6, complement factor B preproprotein, Chain B, Crig Bound To C3c, and WD repeat-containing protein 1 isoform 1 were decreased. Quantitative measurement showed that RARα plasma levels significantly increased in exacerbation state compared to stable state of COPD (n = 14). In the plasma of stable state, the COPD subjects (n = 14) having more than 0.4 time/yr of admission had very high levels of RAR alpha protein and those (n = 11) having less than 0.4 times/yr of admission had the intermediate levels compared to those having no exacerbation (n = 10). ROC analysis of RAR alpha levels to frequency of admission showed an area under the curve of 0.844. A cut-off of 0.154 ng/ml of RAR alpha predicted hospital admission with a sensitivity of 71.4% and a specificity of 92.8%. Conclusion: The proteomic analysis of plasma indicates that alteration of several proteins may be associated with admission of COPD. Among them, plasma RAR alpha level may predict hospital admission with a sensitivity of 71.4% and a specificity of 92.8%. 相似文献
999.
Perumalraja Kirthika Amal Senevirathne Vijayakumar Jawalagatti SungWoo Park 《Gut microbes》2020,11(6):1695-1712
ABSTRACT In the present study, we characterized the involvement of Lon protease in bacterial virulence and intracellular survival in Salmonella under abiotic stress conditions resembling the conditions of a natural infection. Wild type (JOL401) and the lon mutant (JOL909) Salmonella Typhimurium were exposed to low temperature, pH, osmotic, and oxidative stress conditions and changes in gene expression profiles related to virulence and metal ion uptake were investigated. Expression of candidate genes invF and hilC of Salmonella Pathogenicity Island (SPI)-1 and sifA and sseJ of SPI-2 revealed that Lon protease controls SPI-1 genes and not SPI-2 genes under all stress conditions tested. The lon mutant exhibited increased accumulation of hydroxyl (OH·) ions that lead to cell damage due to oxidative stress. This oxidative damage can also be linked to an unregulated influx of iron due to the upregulation of ion channel genes such as fepA in the lon mutant. The deletion of lon from the Salmonella genome causes oxidative damage and increased expression of virulence genes. It also prompts the secretion of host pro-inflammatory cytokines leading to early clearance of the bacteria from host cells. We conclude that poor bacterial recovery from mice infected with the lon mutant is a result of disrupted bacterial intracellular equilibrium and rapid activation of cytokine expression leading to bacterial lysis. 相似文献
1000.
Hanseul Oh Egan Kim Sukjoon Lee Soyeon Park Dongzi Chen Su-Jung Shin Euiseong Kim Sunil Kim 《Materials》2020,13(22)
The aim of this study was to evaluate the biocompatibility of calcium silicate-based sealers (CeraSeal and EndoSeal TCS) and epoxy resin-based sealer (AH-Plus) in terms of cell viability, inflammatory response, expression of mesenchymal phenotype, osteogenic potential, cell attachment, and morphology, of human periodontal ligament stem cells (hPDLSCs). hPDLSCs were acquired from the premolars (n = 4) of four subjects, whose ages extended from 16 to 24 years of age. Flow cytometry analysis showed stemness of hPDLSCs was maintained in all materials. In cell viability test, AH-Plus showed the lowest cell viability, and CeraSeal showed significantly higher cell viability than others. In ELISA test, AH-Plus showed higher expression of IL-6 and IL-8 than calcium silicate-based sealers. In an osteogenic potential test, AH-Plus showed a lower expression level than other material; however, EndoSeal TCS showed a better expression level than others. All experiments were repeated at least three times per cell line. Scanning electronic microscopy studies showed low degree of cell proliferation on AH-Plus, and high degree of cell proliferation on calcium silicate-based sealers. In this study, calcium silicate-based sealers appear to be more biocompatible and less cytotoxic than epoxy-resin based sealers. 相似文献