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971.
972.
Jiayao Ma Zhong You James Byrne Rafik R. Rizkallah 《Annals of biomedical engineering》2014,42(5):960-970
Brain arterial aneurysms are localised dilatation in the wall of cerebral arteries that are common among adult population and associated with high incidence of morbidity and mortality. Using flow diverter stent alone to treat cerebral aneurysm is recognized as a safe and effective method. However, flow diverter stents currently available have limitations due to their braided structures. In this paper a novel flow diverter stent is proposed. It is made out of nitinol tubes that provide adequate radial stiffness and tailored surface coverage to overcome problems of currently available braided stents while retaining low porosity and excellent longitudinal flexibility. Finite element analysis using Abaqus has been conducted to investigate radial stiffness, longitudinal flexibility, and maximum strain during packaging of a series of novel stent designs with varied geometric parameters. Results show that porosity below 70% can be achieved and provides radial stiffness and longitudinal flexibility comparable to those of the Neuroform stent that is commonly used for stent assisted coiling. The novel flow diverter has showed great potential for direct treatment of cerebral aneurysms. 相似文献
973.
974.
为培养高质量的临床医学研究生,我们创立了研究生培养PCI(计划+ 个性、协作+ 交流、传承+ 创新)模式,在此基础上运用PDCA 循环质量管理法对培养过程进行实时监督。研究生在文章发表、课题申报及优秀毕业论文、国内获奖等方面均取得了较好成绩,科研素质、人文素质得到了较大的提高,且该模式在医学院校值得推广。 相似文献
975.
深度融合教育本质的教务系统案例解析 《医学教育管理》2018,4(3):192-195
本文从剖析教务管理系统种种现状困境出发,导引出教务系统设计应遵循的教育核心本质。指出教育、教学、教务和谐共存的方向应该是管理、支持、服务的生态化发展。 相似文献
976.
Fast volumetric imaging of bound and pore water in cortical bone using three‐dimensional ultrashort‐TE (UTE) and inversion recovery UTE sequences 下载免费PDF全文
Jun Chen Michael Carl Yajun Ma Hongda Shao Xing Lu Bimin Chen Eric Y. Chang Zhihong Wu Jiang Du 《NMR in biomedicine》2016,29(10):1373-1380
We report the three‐dimensional ultrashort‐TE (3D UTE) and adiabatic inversion recovery UTE (IR‐UTE) sequences employing a radial trajectory with conical view ordering for bi‐component T2* analysis of bound water (T2*BW) and pore water (T2*PW) in cortical bone. An interleaved dual‐echo 3D UTE acquisition scheme was developed for fast bi‐component analysis of bound and pore water in cortical bone. A 3D IR‐UTE acquisition scheme employing multiple spokes per IR was developed for bound water imaging. Two‐dimensional UTE (2D UTE) and IR‐UTE sequences were employed for comparison. The sequences were applied to bovine bone samples (n = 6) and volunteers (n = 6) using a 3‐T scanner. Bi‐component fitting of 3D UTE images of bovine samples showed a mean T2*BW of 0.26 ± 0.04 ms and T2*PW of 4.16 ± 0.35 ms, with fractions of 21.5 ± 3.6% and 78.5 ± 3.6%, respectively. The 3D IR‐UTE signal showed a single‐component decay with a mean T2*BW of 0.29 ± 0.05 ms, suggesting selective imaging of bound water. Similar results were achieved with the 2D UTE and IR‐UTE sequences. Bi‐component fitting of 3D UTE images of the tibial midshafts of healthy volunteers showed a mean T2*BW of 0.32 ± 0.08 ms and T2*PW of 5.78 ± 1.24 ms, with fractions of 34.2 ± 7.4% and 65.8 ± 7.4%, respectively. Single‐component fitting of 3D IR‐UTE images showed a mean T2*BW of 0.35 ± 0.09 ms. The 3D UTE and 3D IR‐UTE techniques allow fast volumetric mapping of bound and pore water in cortical bone. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
977.
Jingjing Du Peiwen Zhang Jiang Luo Linyuan Shen Shunhua Zhang Hao Gu Jin He Linghui Wang Xue Zhao Mailing Gan Liu Yang Lili Niu Ye Zhao Qianzi Tang Guoqing Tang Dongmei Jiang Yanzhi Jiang Mingzhou Li Anan Jiang Long Jin Jideng Ma Surong Shuai Lin Bai Jinyong Wang Bo Zeng De Wu Xuewei Li Li Zhu 《Gut microbes》2021,13(1)
978.
979.
980.
Mineral trioxide aggregate enriched with iron disulfide nanostructures: an evaluation of their physical and biological properties 下载免费PDF全文
Liliana Argueta‐Figueroa José J. Delgado‐García René García‐Contreras Omar Martínez‐Alvarez José Santos‐Cruz Carlos Oliva‐Martínez Laura S. Acosta‐Torres Javier de la Fuente‐Hernández Ma C. Arenas‐Arrocena 《European journal of oral sciences》2018,126(3):234-243
The purpose of this study was to characterize mineral trioxide aggregates (MTA) enriched with iron disulfide (FeS2) nanostructures at different concentrations, and to investigate their storage modulus, radiopacity, setting time, pH, cytotoxicity, and antimicrobial activity. Iron disulfide nanostructures [with particle size of 0.357 ± 0.156 μm (mean ± SD)] at weight ratios of 0.2, 0.4, 0.6, 0.8, and 1.0 wt% were added to white MTA (wMTA). The radiopacity, rheological properties, setting time, and pH, as well as the cytotoxicity (assessed using the MTT assay) and antibacterial activity (assessed using the broth microdilution test) were determined for MTA/FeS2 nanostructures. The nanostructures did not modify the radiopacity values of wMTA (~6 mm of aluminium); however, they reduced the setting time from 18.2 ± 3.20 min to 13.7 ± 1.8 min, and the storage modulus was indicative of a good stiffness. Whereas the wMTA/FeS2 nanostructures did not induce cytotoxicity when in contact with human pulp cells (HPCs) and human gingival fibroblasts (HGFs), they showed bacteriostatic activity against Staphylococcus aureus, Escherichia coli, and Enterococcus faecalis. Adding FeS2 nanostructures to MTA might be an option for improving the root canal sealing and antibacterial effects of wMTA in endodontic treatments. 相似文献