全文获取类型
收费全文 | 33421篇 |
免费 | 2071篇 |
国内免费 | 349篇 |
学科分类
医药卫生 | 35841篇 |
出版年
2023年 | 170篇 |
2022年 | 132篇 |
2021年 | 1209篇 |
2020年 | 564篇 |
2019年 | 802篇 |
2018年 | 993篇 |
2017年 | 808篇 |
2016年 | 1163篇 |
2015年 | 1543篇 |
2014年 | 1820篇 |
2013年 | 2093篇 |
2012年 | 3106篇 |
2011年 | 3054篇 |
2010年 | 1757篇 |
2009年 | 1546篇 |
2008年 | 2128篇 |
2007年 | 1931篇 |
2006年 | 1712篇 |
2005年 | 1588篇 |
2004年 | 1221篇 |
2003年 | 1080篇 |
2002年 | 908篇 |
2001年 | 793篇 |
2000年 | 727篇 |
1999年 | 515篇 |
1998年 | 217篇 |
1997年 | 144篇 |
1996年 | 124篇 |
1995年 | 93篇 |
1994年 | 104篇 |
1993年 | 92篇 |
1992年 | 151篇 |
1991年 | 159篇 |
1990年 | 180篇 |
1989年 | 149篇 |
1988年 | 139篇 |
1987年 | 126篇 |
1986年 | 103篇 |
1985年 | 79篇 |
1984年 | 52篇 |
1983年 | 49篇 |
1982年 | 36篇 |
1981年 | 42篇 |
1980年 | 31篇 |
1979年 | 26篇 |
1978年 | 29篇 |
1977年 | 35篇 |
1976年 | 24篇 |
1975年 | 24篇 |
1970年 | 29篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
Jae Eun Choi Tyler Werbel Zhenping Wang Chia Chi Wu Tony L. Yaksh Anna Di Nardo 《Journal of dermatological science》2019,93(1):58-64
Background
Rosacea is a chronic inflammatory skin condition whose etiology has been linked to mast cells and the antimicrobial peptide cathelicidin LL-37. Individuals with refractory disease have demonstrated clinical benefit with periodic injections of onabotulinum toxin, but the mechanism of action is unknown.Objectives
To investigate the molecular mechanism by which botulinum toxin improves rosacea lesions.Methods
Primary human and murine mast cells were pretreated with onabotulinum toxin A or B or control. Mast cell degranulation was evaluated by β-hexosaminidase activity. Expression of botulinum toxin receptor Sv2 was measured by qPCR. The presence of SNAP-25 and VAMP2 was established by immunofluorescence. In vivo rosacea model was established by intradermally injecting LL-37 with or without onabotulinum toxin A pretreatment. Mast cell degranulation was assessed in vivo by histologic counts. Rosacea biomarkers were analyzed by qPCR of mouse skin sections.Results
Onabotulinum toxin A and B inhibited compound 48/80-induced degranulation of both human and murine mast cells. Expression of Sv2 was established in mouse mast cells. Onabotulinum toxin A and B increased cleaved SNAP-25 and decreased VAMP2 staining in mast cells respectively. In mice, injection of onabotulinum toxin A significantly reduced LL-37-induced skin erythema, mast cell degranulation, and mRNA expression of rosacea biomarkers.Conclusions
These findings suggest that onabotulinum toxin reduces rosacea-associated skin inflammation by directly inhibiting mast cell degranulation. Periodic applications of onabotulinum toxin may be an effective therapy for refractory rosacea and deserves further study. 相似文献12.
13.
14.
Clinical usefulness of intraductal ultrasonography for the management of acute biliary pancreatitis 下载免费PDF全文
15.
Fluid is usually restricted during thoracic surgery, and vasoactive agents are often administered to maintain blood pressure. One-lung ventilation (OLV) decreases arterial oxygenation; thus oxygen delivery to the brain can be decreased. In this study, we compared phenylephrine and dopamine with respect to maintaining cerebral oxygenation during OLV in major thoracic surgery.Sixty-three patients undergoing lobectomies were randomly assigned to the dopamine (D) or phenylephrine (P) group. The patients’ mean arterial pressure was maintained within 20% of baseline by a continuous infusion of dopamine or phenylephrine. Maintenance fluid was kept at 5 mL/kg/h. The depth of anesthesia was maintained with desflurane 1MAC and remifentanil infusion under bispectral index guidance. Regional cerebral oxygen saturation (rScO2) and hemodynamic variables were recorded using near-infrared spectroscopy and esophageal cardiac Doppler.The rScO2 was higher in the D group than the P group during OLV (OLV 60 min: 71 ± 6% vs 63 ± 12%; P = 0.03). The number of patients whose rScO2 dropped more than 20% from baseline was 0 and 6 in the D and P groups, respectively (P = 0.02). The D group showed higher cardiac output, but lower mean arterial pressure than the P group (4.7 ± 1.0 vs 3.9 ± 1.2 L/min; 76.7 ± 8.1 vs 84.5 ± 7.5 mm Hg; P = 0.02, P = 0.02). Among the variables, age, hemoglobin concentration, and cardiac output were associated with rScO2 by correlation analysis.Dopamine was superior to phenylephrine in maintaining cerebral oxygenation during OLV in thoracic surgery. 相似文献
16.
17.
18.
Three‐Dimensional Echocardiographic Evaluation of Mitral Apparatus during Preload Manipulation in Patients with Hypertrophic Cardiomyopathy 下载免费PDF全文
Hyemoon Chung M.D. Ji Hyun Yoon M.D. Young Won Yoon M.D. Ph.D. Ji Young Chung B.N. Jung‐Joon Cha M.D. Jong‐Youn Kim M.D. Ph.D. Pil‐Ki Min M.D. Ph.D. Byoung‐Kwon Lee M.D. Ph.D. Bum‐Kee Hong M.D. Ph.D. Se‐Joong Rim M.D. Ph.D. Hyuck Moon Kwon M.D. Eui‐Young Choi M.D. Ph.D. 《Echocardiography (Mount Kisco, N.Y.)》2015,32(8):1261-1269
19.
20.
A. Nakao H. Toyokawa A. Tsung M. A. Nalesnik D. B. Stolz J. Kohmoto A. Ikeda K. Tomiyama T. Harada T. Takahashi R. Yang M. P. Fink K. Morita A. M. K. Choi N. Murase 《American journal of transplantation》2006,6(10):2243-2255
Carbon monoxide (CO), a byproduct of heme catalysis, was shown to have potent cytoprotective and anti-inflammatory effects. In vivo recipient CO inhalation at low concentrations prevented ischemia/reperfusion (I/R) injury associated with small intestinal transplantation (SITx). This study examined whether ex vivo delivery of CO in University of Wisconsin (UW) solution could ameliorate intestinal I/R injury. Orthotopic syngenic SITx was performed in Lewis rats after 6 h cold preservation in control UW or UW that was bubbled with CO gas (0.1-5%) (CO-UW). Recipient survival with intestinal grafts preserved in 5%, but not 0.1%, CO-UW improved to 86.7% (13/15) from 53% (9/17) with control UW. At 3 h after SITx, grafts stored in 5% CO-UW showed improved intestinal barrier function, less mucosal denudation and reduced inflammatory mediator upregulation compared to those in control UW. Preservation in CO-UW associated with reduced vascular resistance (end preservation), increased graft cyclic guanosine monophosphate levels (1 h), and improved graft blood flow (1 h). Protective effects of CO-UW were reversed by ODQ, an inhibitor of soluble guanylyl cyclase. In vitro culture experiment also showed better preservation of vascular endothelial cells with CO-UW. The study suggests that ex vivo CO delivery into UW solution would be a simple and innovative therapeutic strategy to prevent transplant-induced I/R injury. 相似文献