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Direct-to-indirect mapping for optimal low-thrust trajectories

第三届全球华人眼科学术大会暨中华医学会第十一届全国眼科学术大会

作者： s．He R．subramanyan V．Krasnoperov Y．Kim D．Zhu E．A．Barron A．Rodriguez s．j．ryan P．s．Gill D．R．Hinton Departments of Pathology Ophthalmology and MedicineKeck School of Medicine at University of Southern California the Doheny Eye Institute Los AngelesCA and Vasgene TherapeuticsInc Los Angeles CA

Purpose: EphB4 receptor and its ligand (EphrinB2) are critical regulators of cell adhesion, growth, migration and vascular assembly. Recombinant soluble form of EphB4 extracellular domain (sEphB4) inhibits vessel maturation and angiogenesis. The purpose of this study was to evaluate the effect sEphB4 receptor on the regulation of choroidal endothelial cell (CEC) and retinal pigment epithelial cell function (RPE) cell function and the inhibition of laser induced choroidal neovascularization (CNV). Methods: Early passage bovine CEC and human fetal RPE cells were used in the study. Effect of sEphB4 on PDGF or VEGF induced CEC

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Astrodynamics 2024年第1期8卷 27-46页

作者： David Ottesen ryan P.Russell Department of Aerospace Engineering and Engineering Mechanics The University of Texas at AustinAustinTexas78712USA

Optimal,many-revolution spacecraft trajectories are challenging to solve.A connection is made for a class of models between optimal direct and indirect *** transfers that minimize thrust-acceleration-squared,primer vector theory maps direct,many-impulsive-maneuver trajectories to the indirect,continuous-thrust-acceleration *** mapping algorithm is independent of how the direct solution is obtained and requires only a solver for a boundary value problem and its partial derivatives.A Lambert solver is used for the two-body problem in this *** mapping is simple because the impulsive maneuvers and co-states share the same linear space around an optimal *** numerical results,the direct coast-impulse solutions are demonstrated to converge to the indirect continuous solutions as the number of impulses and segments *** two-body design space is explored with a set of three many-revolution,many-segment examples changing semimajor axis,eccentricity,and *** first two examples involve a small change to either semimajor axis or eccentricity,and the third example is a transfer to geosynchronous *** a single processor,the optimization runtime is seconds to minutes for revolution counts of 10 to 100,and on the order of one hour for examples with up to 500 *** of these thrust-acceleration-squared solutions are good candidates to start a homotopy to a higher-fidelity minimization problem with practical constraints.

关键词： direct optimization indirect optimization impulsive maneuvers Lambert's problem two-body dynamics primer vectortheory

Management of gestational diabetes mellitus via nutritional interventions:The relevance of gastric emptying

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World journal of Diabetes 2024年第7期15卷 1394-1397页

作者： Wei-Kun Huang ryan j jalleh Christopher K Rayner Tong-Zhi Wu Adelaide Medical school and Centre of Research Excellence in Translating Nutritional science to Good Health The University of AdelaideAdelaide 5000Australia Adelaide Medical school and Centre of Research Excellence in Translating Nutritional science to Good Health The University of Adelaide and Department of Gastroenterology and HepatologyRoyal Adelaide HospitalAdelaide 5000Australia

Gestational diabetes mellitus(GDM)represents one of the most common medical complications of pregnancy and is important to the well-being of both mothers and offspring in the short and long *** intervention remains the mainstay for the management of *** efficacy of nutritional approaches(*** restriction and small frequent meals)to improving the maternal-neonatal outcomes of GDM was attested to by Chinese population data,discussed in two articles in recent issues of this ***,a specific focus on the relevance of postprandial glycaemic control was *** rather than fasting hyperglycaemia often represents the predominant manifestation of disordered glucose homeostasis in Chinese women with *** is now increasing appreciation that the rate of gastric emptying,which controls the delivery of nutrients for digestion and absorption in the small intestine,is a key determinant of postprandial glycaemia in both health,type 1 and 2 *** remains to be established whether gastric emptying is abnormally rapid in GDM,particularly among Chinese women,thus contributing to a predisposition to postprandial hyperglycaemia,and if so,how this influences the therapeutic response to nutritional *** is essential that we understand the role of gastric emptying in the regulation of postprandial glycaemia during pregnancy and the potential for its modulation by nutritional strategies in order to improve postprandial glycaemic control in GDM.

关键词： Gastric emptying Postprandial glycaemia Diet Nutritional interventions Gestational diabetes mellitus

Machine learning-guided accelerated discovery of structure-property correlations in lean magnesium alloys for biomedical applications

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journal of Magnesium and Alloys 2024年第6期12卷 2267-2283页

作者： sreenivas Raguraman Maitreyee sharma Priyadarshini Tram Nguyen ryan McGovern Andrew Kim Adam j.Griebel Paulette Clancy Timothy P.Weihs Department of Materials science and Engineering Johns Hopkins University3400 N Charles StBaltimore21218MDU.S.A Hopkins Extreme Materials Institute Johns Hopkins University3400 N Charles StBaltimore21218MDU.S.A Department of Chemical and Biomolecular Engineering Johns Hopkins University3400 N Charles StBaltimore21218MDU.S.A Translational Tissue Engineering Center Johns Hopkins School of Medicine400 N BroadwayBaltimore21231MDU.S.A Department of Biomedical Engineering Johns Hopkins University3400 N Charles StBaltimore21218MDU.S.A Research and Development Fort Wayne Metals Research ProductsLLC9609 Ardmore AveFort Wayne46809INU.S.A Department of Mechanical Engineering Johns Hopkins University3400 N Charles StBaltimore21218MDU.S.A

Magnesium alloys are emerging as promising alternatives to traditional orthopedic implant materials thanks to their biodegradability,biocompatibility,and impressive mechanical ***,their rapid in-vivo degradation presents challenges,notably in upholding mechanical integrity over *** study investigates the impact of high-temperature thermal processing on the mechanical and degradation attributes of a lean Mg-Zn-Ca-Mn alloy,*** rapid,cost-efficient characterization methods like X-ray diffraction and optical microscopy,we swiftly examine microstructural changes post-thermal *** Pearson correlation coefficient analysis,we unveil the relationship between microstructural properties and critical targets(properties):hardness and corrosion ***,leveraging the least absolute shrinkage and selection operator(LAssO),we pinpoint the dominant microstructural factors among closely correlated *** findings underscore the significant role of grain size refinement in strengthening and the predominance of the ternary Ca_(2)Mg_(6)Zn_(3)phase in corrosion *** suggests that achieving an optimal blend of strength and corrosion resistance is attainable through fine grains and reduced concentration of ternary *** thorough investigation furnishes valuable insights into the intricate interplay of processing,structure,and properties in magnesium alloys,thereby advancing the development of superior biodegradable implant materials.

关键词： Magnesium alloys Machine learning Corrosion Mechanical properties Rapid characterization

Millimetric devices for nerve stimulation:a promising path towards miniaturization

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Neural Regeneration Research 2024年第8期19卷 1702-1706页

作者： ryan M.Dorrian Anna V.Leonard Antonio Lauto spinal Cord Injury Research Group School of BiomedicineThe University of AdelaideAdelaideSAAustralia school of science Western Sydney UniversityPenrithNSWAustralia

Nerve stimulation is a rapidly developing field,demonstrating positive outcomes across several *** potential benefits,current nerve stimulation devices are large,complicated,and are powered via implanted pulse *** facto rs necessitate invasive surgical implantation and limit potential *** nerve stimulation devices to millimetric sizes would make these interventions less invasive and facilitate broader therapeutic ***,device miniaturization presents a serious engineering *** review presents significant advancements from several groups that have overcome this challenge and developed millimetricsized nerve stimulation *** are based on antennas,mini-coils,magneto-electric and optoelectronic materials,or receive ultrasound *** highlight key design elements,findings from pilot studies,and present several considerations for future applications of these devices.

关键词： biomedical engineering deep brain stimulation electrical engineering electrical stimulation neuromodulation peripheral nerve stimulation

Exploiting blockchain for dependable services in zero-trust vehicular networks

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Frontiers of Computer science 2024年第2期18卷 157-166页

作者： Min HAO Beihai TAN siming WANG Rong YU ryan Wen LIU Lisu YU school of Automation Guangdong University of TechnologyGuangzhou 510006China school of Integrated Circuits Guangdong University of TechnologyGuangzhou 510006China school of Navigation Wuhan University of TechnologyWuhan 430063China school of Information Engineering Nanchang UniversityNanchang 330031China

The sixth-generation(6G)wireless communication system is envisioned be cable of providing highly dependable services by integrating with native reliable and trustworthy ***-trust vehicular networks is one of the typical scenarios for 6G dependable *** the technical framework of vehicle-and-roadside collaboration,more and more on-board devices and roadside infrastructures will communicate for information *** reliability and security of the vehicle-and-roadside collaboration will directly affect the transportation *** a zero-trust vehicular environment,to prevent malicious vehicles from uploading false or invalid information,we propose a malicious vehicle identity disclosure approach based on the shamir secret sharing ***,a two-layer consortium blockchain architecture and smart contracts are designed to protect the identity and privacy of benign vehicles as well as the security of their private *** that,in order to improve the efficiency of vehicle identity disclosure,we present an inspection policy based on zero-sum game theory and a roadside unit incentive mechanism jointly using contract theory and subjective logic *** verify the performance of the entire zero-trust solution through extensive simulation *** the premise of protecting the vehicle privacy,our solution is demonstrated to significantly improve the reliability and security of 6G vehicular networks.

关键词： sixth-generation(6G) zero-trust block-chain vehicular networks privacy preservation

Generalized polynomial chaos expansion by reanalysis using static condensation based on substructuring

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 819-836页

作者： D.LEE s.CHANG j.LEE Department of Automotive Engineering Hanyang UniversitySeoul 04763Republic of Korea school of Mechanical Engineering Chungnam National UniversityDaejeon 34134Republic of Korea Department of Mechanical Robotics and Energy EngineeringDongguk UniversitySeoul 04620Republic of Korea

This paper presents a new computational method for forward uncertainty quantification(UQ)analyses on large-scale structural systems in the presence of arbitrary and dependent random *** method consists of a generalized polynomial chaos expansion(GPCE)for statistical moment and reliability analyses associated with the stochastic output and a static reanalysis method to generate the input-output data *** the reanalysis,we employ substructuring for a structure to isolate its local regions that vary due to random *** allows for avoiding repeated computations of invariant substructures while generating the input-output data *** substructuring with static condensation further improves the computational efficiency of the reanalysis without losing ***,the GPCE with the static reanalysis method can achieve significant computational saving,thus mitigating the curse of dimensionality to some degree for UQ under high-dimensional *** numerical results obtained from a simple structure indicate that the proposed method for UQ produces accurate solutions more efficiently than the GPCE using full finite element analyses(FEAs).We also demonstrate the efficiency and scalability of the proposed method by executing UQ for a large-scale wing-box structure under ten-dimensional(all-dependent)random inputs.

关键词： forward uncertainty quantification(UQ) generalized polynomial chaos expansion(GPCE) static reanalysis method static condensation substructuring

The secondary injury cascade after spinal cord injury:an analysis of local cytokine/chemokine regulation

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Neural Regeneration Research 2024年第6期19卷 1308-1317页

作者： Daniel j.Hellenbrand Charles M.Quinn Zachariah j.Piper ryan T.Elder Raveena R.Mishra Taylor L.Marti Phoebe M.Omuro Rylie M.Roddick jae sung Lee William L.Murphy Amgad s.Hanna Department of Neurosurgery University of Wisconsin-Madison School of Medicine and Public HealthMadisonWIUSA Department of Biomedical Engineering University of Wisconsin-MadisonMadisonWIUSA Department of Orthopedics and Rehabilitation University of Wisconsin-MadisonMadisonWIUSA Department of Materials science and Engineering University of Wisconsin-MadisonMadisonWIUSA Forward BIO Institute University of Wisconsin-MadisonMadisonWIUSA

After spinal cord injury,there is an extensive infiltration of immune cells,which exacerbates the injury and leads to further neural ***,a major aim of current research involves targeting the immune response as a treatment for spinal cord *** much research has been performed analyzing the complex inflammatory process following spinal cord injury,there remain major discrepancies within previous literature regarding the timeline of local cytokine *** objectives of this study were to establish an overview of the timeline of cytokine regulation for 2 weeks after spinal cord injury,identify sexual dimorphisms in terms of cytokine levels,and determine local cytokines that significantly change based on the severity of spinal cord *** were inflicted with either a mild contusion,moderate contusion,severe contusion,or complete transection,7 mm of spinal cord centered on the injury was harvested at varying times post-injury,and tissue homogenates were analyzed with a Cytokine/Chemokine 27-Plex *** demonstrated pro-inflammatory cytokines including tumor necrosis factorα,interleukin-1β,and interleukin-6 were all upregulated after spinal cord injury,but returned to uninjured levels within approximately 24 hours post-injury,while chemokines including monocyte chemoattractant protein-1 remained upregulated for days *** contrast,several anti-inflammatory cytokines and growth factors including interleukin-10 and vascular endothelial growth factor were downregulated by 7 days *** spinal cord injury,tissue inhibitor of metalloproteinase-1,which specifically affects astrocytes involved in glial scar development,increased more than all other cytokines tested,reaching 26.9-fold higher than uninjured *** a mild injury,11 cytokines demonstrated sexual dimorphisms;however,after a severe contusion only leptin levels were different between female and male *** conclusion,pro-inflammatory cytokines in

关键词： astrocytes chemokines cytokines inflammation macrophages microglia secondary damage spinal cord injury

Characterizing objective and self-report habitual physical activity and sedentary time in outpatients with an acquired brain injury

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sports Medicine and Health science 2024年第4期6卷 338-343页

作者： Liam P.Pellerine Katerina Miller ryan j.Frayne Myles W.O'Brien Division of Kinesiology School of Health and Human PerformanceFaculty of HealthDalhousie UniversityHalifaxNova ScotiaCanada Acquired Brain Injury NeuroCommons Nova Scotia Health AuthorityHalifaxNova ScotiaCanada school of Physiotherapy(Faculty of Health)&Department of Medicine(Faculty of Medicine) Dalhousie UniversityHalifaxNova ScotiaCanada Geriatric Medicine Research Dalhousie University&Nova Scotia HealthHalifaxNova ScotiaCanada Centre de Formation Medicale Du Nouveau-Brunswick New Brunswick&Department of MedicineUniversite de SherbrookeSherbrookeQuebecCanada

Outpatients with an acquired brain injury(ABI)experience physical,mental,and social *** can be classified into two subgroups based on mechanism of injury:mild traumatic brain injury(mTBI;e.g.,concussion)and other ABI(e.g.,stroke,brain aneurysm,encephalitis).Our understanding of habitual activity levels within ABI populations is limited because they are often collected using self-report *** purpose of this study was to,1)describe the habitual activity levels of outpatients with ABI using objective and self-report monitoring,and 2)compare the activity levels of outpatients with mTBI *** *** outpatients with other ABI(mean±standard deviation:[58±13]years,9 females)and 12 outpatients with mTBI([48±11]years,9 females)wore a thigh-worn activPAL 24 h/day(h/day)for *** with ABI averaged(6.0±2.3)h/day of upright time,(10.6±2.2)h/day of sedentary time,(5.6±2.7)h/day in prolonged sedentary bouts>1 h,(5960±3037)steps/day,and(11±13)minutes/day(min/day)of moderate-vigorous physical activity(MVPA).There were no differences between activPAL-derived upright,sedentary,prolonged sedentary time,and physical activity between the mTBI and other ABI groups(all,p>0.31).Outpatients with ABI overestimated their MVPA levels(t138 min/week)and underestimated sedentary time(-4.3 h/day)compared to self-report(all,pspite self-reporting high activity levels,outpatients with ABI objectively exhibit highly inactive and sedentary *** habitual movement behaviours of our sample did not differ by mechanism of injury(i.e.,mTBI versus other ABI).Targeting reductions in objectively measured sedentary time are needed to progressively improve the habitual movement behaviours of outpatients with ABI.

关键词： Accelerometry stroke Brain aneurysm Encephalitis Mild traumatic brain injury Rehabilitation