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基于区块链的电子病历安全高效共享方法

信息安全研究 2025年第1期11卷 74-80页

作者：谷占新马利民王佳慧张伟北京信息科技大学计算机学院北京100101 北京信息科技大学北京未来区块链与隐私计算高精尖中心北京100101 国家信息中心信息与网络安全部北京100045

针对医疗机构之间共享电子病历所面临的挑战,如隐私泄露风险和低效的检索问题,提出一种基于区块链的电子病历高效加密检索与共享方案.首先,该方案一方面通过在云服务器上存储加密后的电子病历,并在联盟链上实施检索过程,有效地实现了存... 详细信息

针对医疗机构之间共享电子病历所面临的挑战,如隐私泄露风险和低效的检索问题,提出一种基于区块链的电子病历高效加密检索与共享方案.首先,该方案一方面通过在云服务器上存储加密后的电子病历,并在联盟链上实施检索过程,有效地实现了存储与检索的分离;另一方面加入混淆陷门集合,从而显著降低了关键字猜测攻击的风险.其次,考虑到医疗数据的特殊性,提出一种优化的倒排索引结构,有效解决了处理大量电子病历时的检索效率问题.最后,基于此索引结构,开发了一种密文检索算法,该算法通过结合可搜索加密中的陷门技术和倒排索引中的关键字密文,实现了高效的密文检索.实验结果显示,该方案在实现隐私保护的前提下,成功解决了医疗行业电子病历共享的问题,同时显著提升了系统的运行效率.

关键词：区块链可搜索加密隐私保护国密算法数据共享

维普期刊数据库博看期刊

Optically pumped semiconductor nanowire lasers

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Frontiers of Optoelectronics 2012年第3期5卷 239-247页

作者： Yaoguang ma limin TONG State Key Laboratory of Modem Optical Instrumentation Department of Optical Engineering Zhejiang University Hangzhou 310027 China

This paper reviews our recent work on fabrication, optical characterization and lasing application of semiconductor nanowires, with brief introduction of related work from many other groups.

关键词： semiconductor nanowire nanowire laser,optical pump microfiber

Improvement and application of Y2O3 directional solidification crucible

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Chinese Journal of Aeronautics 2016年第2期29卷 554-559页

作者： ma limin Zhang Jiazhen Yue Guangquan Zhang Huarui Zhou Li Zhang Hu Beijing Aeronautical Science & Technology Research Institute of COmaC Bering 102211 Chinab School of materials Science and Engineering Beihang University Beijing 100191 China

In order to satisfy the drastic temperature change and high chemical activity in direc- tional solidification of Nb Si based alloys, Y2O3 crucible is demanded to possess high thermal shock resistance and erosion resistance. This paper improved the sintering degree and density of Y2O3 crucible by optimizing the sintering temperature and time, and its practical application per- formance was investigated. Y2O3 grains gathered with the increase of sintering temperature and time, and the contact area enlarged, resulting in the open pores being changed into closed pores. The higher density caused the improvement of erosion resistance of Y2O3 crucibles. However, exces- sive density weakened the thermal shock resistance. Considering high-temperature strength, erosion resistance, thermal shock resistance and costs, optimum sintering temperature and time of Y2O3 directional solidification crucible were 1800 ℃ and 120min, respectively, and the porosity was 20%. Improved Y2O3 crucible has been successfully applied to directional solidification of Nb Si based alloys, and significantly reduced the oxygen contamination. Slight interaction occurred between Hf and Y2O3, but no obvious dissolution, penetration or erosion was found, showing good erosion resistance and thermal shock resistance.

关键词： Directional solidification Erosion resistance Microstructure Nb-Si based alloy Thermal shock resistanceY2O3 crucible

Tree-ring precipitation records from Baiyinaobao, Inner Mongolia since A.D. 1838

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Chinese Science Bulletin 2003年第11期48卷 1140-1145页

作者： LIU Yu CAI Qiufang Park Won-Kyu AN Zhisheng ma limin State Key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of SciencesXi'an 710075 China School of Forest Resources Chungbuk National UniversityCheongju 361-763 Korea State Key Laboratory of Pollution and Resource of Tongji University Shanghai 200092 China

Correlation function analysis shows that total precipitation from April to early July (to July 10) in growing season limits the ring width of Picea Koraiensis significantly in Baiyinaobao, Xilinhot, Inner Mongolia. Thus a transfer function is designed to reconstruct the total precipitation from April to early July over the region for the last 160 years. The explained variance of the reconstruction is 49.3% (and 45.7% when adjusted for loss of degrees of freedom, N = 31, r = 0.702, F = 13.608, p < 0.0001). There are three relatively wet periods in the reconstruction which are: 1869—1875, 18861921 and 19431968, and four relatively dry periods: 1851—1868, 1876—1885, 1922—1943 and 1969—1999. Among them, the wet periods of 1886—1921 and 1943—1968, and the dry period of 1922—1943 appeared almost at the same time with those in Mt. Qilian region. Meanwhile, the dry period of 1922—1943 corresponds to high temperature and low rainfall during the 1920s and thereafter, and wetness of 1943—1968 corresponds very well to low temperature and more precipitation after the 1940s in Northwest, Northern China and the Changjiang River drainage basin. Calculation shows that the reconstruction series is significantly correlated with local dry-wet index (r = -0.234, p < 0.007, N = 143). Wavelet analysis indicates that there is a 22-a cycle in the precipitation of April to early July during 18381920, and an 11-a cycle during 1920—1952. No more cycles that reach 95% confidence limits are identified after 1953. The precipitation from April to early July quickly dropped into low during the 1920s. After 1950, precipitation shows a declining trend, but the reconstruction shows a tendency of increase in the late of 1990s.

关键词：内蒙古降雨量湿季干季周期

Microstructure evolution and room temperature deformation of a directionally solidiied Nb-Si-Ti-Cr-Al-Hf-Y alloy

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China Foundry 2013年第6期10卷 345-350页

作者： Wang Bin Jia Lina Yuan Sainan ma limin Su Linfen Zhang Hu School of materials Science and Engineering Beihang University

An Nb-14Si-22Ti-4Cr-2AI-2Hf-0.15Y（at.%） alloy was prepared by directional solidification （DS） with liquid metal cooling, and the withdrawal rates selected were 1.2, 6, and 18 mm-min1, respectively. The Influence of withdrawal rate and heat treatment on the microstructural evolution, fracture toughness and tensile strength at room temperature were investigated. Results show that the directionally solidified microstructure is composed of primary （Nb, X）ss dendrites and （Nb, X）ss/a-（Nb, X）5Si3 eutectic cells aligning with the growth direction. The formation of bulk Nb3Si is suppressed. With an increase in withdrawal rate, the dendrite arm spacing of （Nb, X）ss decreases, and the （Nb, X）ss/a-（Nb, X）5Si3 eutectic cells become finer and distribute homogeneously. Directional solidification can significantly improve the room temperature fracture toughness, especially the alloy with a withdrawal rate of 6 ***-1; its average value reaches 14.1 MPa.m^0.5, about 34% higher than that of the alloy without directional solidification. The withdrawal rate has obvious effect on tensile strength, and the tensile strength is improved from 200 MPa to 429 MPa as the withdrawal rate increases from 1.2 ***-1 to 1.8 mm-min-1. After heat treatment, the primary （Nb, X）ss branches become coarser; both the room temperature fracture toughness and tensile strength of the alloys solidified at 1.2 and 6 *** 1 are somewhat lower than the corresponding values of the alloy without heat treatment, while they are higher than the corresponding values of the alloy without heat treatment when solidified at 18 mm-min4.

关键词： Nb-Si-Ti-Cr-Al-Hf-Y directional solidification heat treatment mechanical properties

Microstructure characteristics of Ni-43Ti-4Al-2Nb-2Hf alloy prepared by conventional casting and directional solidification

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China Foundry 2012年第2期9卷 101-107页

作者： Pan Liwen Zheng Lijing Zhou Lei Zhang Huarui Tang Xiaoxia ma limin Zhang Hu School of materials Science and Engineering Beijing University of Aeronautics and AstronauticsBeijing 100191China

To further investigate the microstructure characteristic and solidification mechanism, so as to provide knowledge for the microstructure control of a NiTi-AI based high-temperature structural material, the microstructure of Ni-43Ti-4AI-2Nb-2Hf （at.%） alloy ingots prepared by conventional casting （arc-melting） and directional solidification （DS） at various drawing velocities （2 ***-＇, 18 ***-1, 30 mm-min-＇ and 60 mmmin~, respectively） was investigated by means of electron probe microanalyses. Experimental results reveal that the microstructures are composed of NiTi matrix phase,/3-Nb phase and Ti2Ni phase for samples obtained by both conventional casting and DS. Conventional casting has an equiaxial structure, while DS has a slender and acicular cellular structure which grows along the [001] orientation preferentially. Small amounts of white/3-Nb phase and black Ti2Ni phase co-exist at the grain boundaries or intercellular regions. With an increase in drawing velocity, the NiTi matrix phase is inclined to grow along （100） and （200） crystallographic planes, and the cellular arm spacing reduce gradually, but the directionality of the solidified structure weakens significantly. The homogeneous dispersion of,8-Nb phase and the decrease of Ti2Ni phase in DS samples are beneficial to improving the mechanical properties. Solidification mechanism analysis indicates that the dark grey NiTi matrix phase initially precipitates from the liquid phase, and then the divorced eutectic reaction takes place, which produces the light gray matrix phase and/^-Nb phase. Finally, the peritectic reaction happens, which generates the black Ti2Ni phase.

关键词： Ni-Ti-Al-Nb-Hf alloy conventional casting directional solidification drawing velocity microstructural characteristic solidification mechanism

Improved osteointegration and angiogenesis of strontium-incorporated 3D-printed tantalum scaffold via bioinspired polydopamine coating

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Journal of materials Science & Technology 2021年第10期69卷 106-118页

作者： Shi Cheng Jin Ke Mengyu Yao Hongwei Shao Jielong Zhou Ming Wang Xiongfa Ji Guoqing Zhong Feng Peng limin ma Yu Zhang Department of Orthopedics Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China The Second School of Clinical Medicine Southern Medical UniversityGuangzhou 510515China

Tantalum(Ta)is used in orthopedic implants because it has excellent ***,high elastic modulus,bio-inertness,and unsatisfactory osteointegration limits its wider use in clinical ***,a 3 D porous Ta scaffold with low elastic modulus was fabricated using selective laser melting(SLM).Strontium(Sr)was incorporated on the surface of the scaffold with the aid of polydopamine(PDA)to further improve its osteointegration *** prepared scaffolds exhibited a stable Sr ion release in 14 *** bone marrow stem cells(BMSCs)showed improved early adhesion and spreading after Sr was incorporated on the porous Ta *** osteogenic behavior,including extracellular matrix mineralization(ECM),alkaline phosphatase activity(ALP),and expression of bone-related RNA,were all ***,the Sr-incorporated porous Ta scaffolds exhibited better angiogenic behavior,such as promoting migration,tube formation,and angiogenesis-related RNA expression abilities of human vascular endothelial cells(HUVECs).Additionally,histological images(H&E,masson and CD31 immunofluorescent staining)suggested that Sr-incorporated porous Ta scaffolds displayed enhanced osteointegration and angiogenesis after implantation in rat femur for 12 *** findings prove that the PDA-based Sr-incorporated porous Ta scaffolds show promising use in orthopedic implants.

关键词： 3D Ta scaffold Strontium Osteogenesis Angiogenesis Orthopedic implant

Structural insights into signal transduction of the purinergic receptors P2Y_(1)R and P2Y_(12)R

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Protein & Cell 2023年第5期14卷 382-386页

作者： Beibei Li Shuo Han Mu Wang Yu Yu limin ma Xiaojing Chu Qiuxiang Tan Qiang Zhao Beili Wu AS Key Laboratory of Receptor Research State Key Laboratory of Drug ResearchShanghai Institute of Materia MedicaChinese Academy of SciencesShanghai201203China University of Chinese Academy of Sciences Beijing 100049China School of Life Science and Technology ShanghaiTech UniversityShanghai 201210China Zhongshan Institute for Drug Discovery Shanghai Institute of Materia MedicaChinese Academy of SciencesZhongshan 528400China School of Pharmaceutical Science and Technology Hangzhou Institute for Advanced StudyUCASHangzhou 310024China

Dear Editor,The purinergic receptors(P2YRs)are involved in a variety of physiological processes,including proliferation,chemotaxis,cancer metastasis,cardiovascular events,neurodegenerative diseases and aging(Weisman et al.,2012).Thus far,eight human P2YRs have been characterized and are classified into two subfamilies based on their sequence homology and signal transduction mechanisms,including P2Y1 R-like receptors that signal preferentially through Gq/11 proteins and P2Y12R-like receptors that activate Gi/o proteins(Abbracchio et al.,2006).

关键词： P2Y cardiovascular

Promoting Bone Mesenchymal Stem Cells and Inhibiting Bacterial Adhesion of Acid-Etched Nanostructured Titanium by Ultraviolet Functionalization

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Journal of materials Science & Technology 2015年第2期31卷 182-190页

作者： Guobo Lan Mei Li Ying Tan Lihua Li Xiaoming Yang limin ma Qingshui Yin Hong Xia Yu Zhang Guoxin Tan Chengyun Ning Southern Medical University Hospital of Orthopedics General Hospital of Guangzhou Military Command Faculty of Light and Chemical Guangdong University of Technology College of materials Science and Technology South China University of Technology

Titanium(Ti) and its alloys are used extensively in orthopedic implants because of their excellent biocompatibility,mechanical properties and corrosion resistance. However,titanium-based implant materials face many severe complications,such as implant loosening due to poor osseointegration and bacterial infections,which may lead to implant failure. Hence,preparing a biomaterial surface,which enhances the interactions with host cells and inhibits bacterial adhesion,may be an optimal strategy to reduce the incidence of implant failure. This study aims to improve osseointegration and confer antibacterial properties on Ti through a combination of two surface modifications including nanostructuring generated by acid etching and ultraviolet(UV) light *** results showed that without UV treatment,the acid etching treatment of Ti surface was effective at both improving the adhesion of bone mesenchymal stem cells(BMSCs) and increasing bacterial adhesion. A further UV treatment of the acid-etched surface however,not only significantly improved the cell adhesion but also inhibited bacterial adhesion. The acid-etched nanostructured titanium with UV treatment also showed a significant enhancement on cell proliferation,alkaline phosphatase(ALP) activity and mineralization. These results suggest that such nanostructured materials with UV treatment can be expected to have a good potential in orthopedic applications.

关键词： UV treatment Nanostructures Bone mesenchymal stem