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Fluid-Structure Interaction Analysis of Brain Tissue During Head Impacts Using Newtonian and Non-Newtonian Cerebrospinal Fluid Models

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ASME Open Journal of Engineering 2025年 4卷 041003页

作者： Hemmati, Parnian Prins, Mayumi L. Giza, Christopher C. Kavehpour, H. Pirouz Department of Mechanical and Aerospace Engineering University of California Los Angeles Los AngelesCA90095 United States Department of Neurosurgery David Geffen School of Medicine University of California Los Angeles Los AngelesCA90095 United States The UCLA Brain Injury Research Center University of California Los Angeles Los AngelesCA90095 United States The UCLA Steve Tisch BrainSPORT Program University of California Los Angeles Los AngelesCA90095 United States Department of Pediatrics University of California Los Angeles Los AngelesCA90095 United States Interdepartmental Programs for Neuroscience and Biomedical Engineering University of California Los Angeles Los AngelesCA90095 United States Department of Bioengineering University of California Los Angeles Los AngelesCA90095 United States

Traumatic brain injury (TBI) caused mainly by external head impacts poses significant health concerns globally. Understanding the mechanics behind TBI during head impacts is crucial for developing effective preventive and therapeutic strategies. In this study, the fluid-structure interaction within the system comprising the skull, brain, and the cerebrospinal fluid (CSF)-filled gap is investigated using finite element methods (FEM). Unlike most studies that model CSF as a solid, this research models CSF as a fluid, focusing on its fluid dynamics and their impact on brain tissue response to external head impacts. Additionally, this study is the first to model CSF as a non-Newtonian fluid, exploring its influence on injury metrics compared to a Newtonian CSF model. The results demonstrate significant pressure build-up and shear rate variations within the CSF due to impact. The model shows that maximum strain values are concentrated in the central regions of the brain tissue rather than at its interface with the CSF. Comparative analysis of the first and third principal strains shows that the tissue experiences twice as much compressive strain compared to tensile strain. Further, the comparison between Newtonian and non-Newtonian CSF models shows that the non-Newtonian model results in lower shear rates. This leads to a decrease in tissue strain, with a 4.3% reduction in the first principal strain and a 6.7% reduction in the third principal strain for the non-Newtonian CSF model. These findings underscore the importance of accurately modeling CSF properties to better understand TBI mechanisms. Copyright © 2025 by ASME;reuse license CC-BY 4.0.

关键词： Non Newtonian flow

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Multi-tracer PET Imaging Using Deep Learning: Applications in Patients with High-Grade Gliomas 1

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5th International Workshop on Predictive Intelligence in Medicine (PRIME MICCAI)

作者： Wardak, Mirwais Hooper, Sarah M. Schiepers, Christiaan Chen, Wei Aparici, Carina Mari Davidzon, Guido A. Vermesh, Ophir Cloughesy, Timothy F. Huang, Sung-Cheng Gambhir, Sanjiv Sam Stanford Univ Sch Med Mol Imaging Program Stanford MIPS Dept Radiol Stanford CA 94305 USA Stanford Univ Stanford Cardiovasc Inst Stanford CA USA Stanford Univ Dept Elect Engn Stanford CA USA UCLA David Geffen Sch Med Dept Mol & Med Pharmacol Ahmanson Translat Imaging Div Los Angeles CA USA UCLA David Geffen Sch Med UCLA Neuro Oncol Program Dept Neurol Los Angeles CA USA Stanford Univ Dept Bioengineering Dept Mat Sci & Engn Stanford CA USA Stanford Univ Stanford Bio X Stanford CA USA

ISBN: (数字)9783031169199

ISBN: (纸本)9783031169199;9783031169182

One of the great strengths of positron emission tomography (PET) is its ability to quantitatively image a wide array of molecular targets for disease evaluation. However, multi-tracer PET imaging is hindered because current technology permits only one PET tracer to be imaged at a time. The aim of this study was to develop a deep learning system that uses a PET image obtained with one tracer to predict a synthetic PET image of a different tracer without having to actually inject the second tracer. Deep neural networks were designed to generate synthetic 3'-deoxy-3'-[F-18]-fluorothymidine (F-18-FLT) PET images from 3,4-dihydroxy-6-[F-18]-fluoro-L-phenylalanine (F-18-FDOPA) PET and magnetic resonance imaging scans of nineteen patients with glioblastoma. Here, we show that the proposed image synthesis method closely predicts the ground truth F-18-FLT PET images (MAE = 0.024 +/- 0.004, SSIM = 0.832 +/- 0.035, PSNR = 27.521 +/- 1.606). Moreover, a blinded image evaluation by three nuclear medicine physicians determined that the synthetic images were rated significantly better on spatial resolution (p < 0.015), image noise (p < 0.001) and overall image quality (p < 0.0001) than the true PET images. This study offers a new strategy for multi-tracer PET imaging using machine learning and reduces radiation dose to the patient by at least 50%.

关键词： Deep learning Multi-tracer PET Synthetic images

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Early Postoperative Conjunctival Complications Leading to Exposure of Surgically Implanted CorNeat EverPatch Devices

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Ophthalmology 2025年第7期132卷 799-814页

作者： Kanter, Jacob Garkal, Atul Cardakli, Nur Pitha, Ian Sabharwal, Jasdeep Schein, Oliver D. Ramulu, Pradeep Y. Parikh, Kunal S. Johnson, Thomas V. Glaucoma Center of Excellence Wilmer Eye Institute Johns Hopkins University School of Medicine Baltimore Maryland United States Center for Nanomedicine Wilmer Eye Institute Johns Hopkins University School of Medicine Baltimore Maryland United States Moran Eye Center University of Utah Salt Lake City Utah United States North Bay Eye Associates Petaluma CA United States Cornea Division Wilmer Eye Institute Johns Hopkins University School of Medicine Baltimore Maryland United States Center for Bioengineering Innovation & Design Department of Biomedical Engineering Johns Hopkins University School of Medicine Baltimore Maryland United States Cellular and Molecular Medicine Program Johns Hopkins University School of Medicine Baltimore Maryland United States

Purpose: To compare the early exposure and surgical revision rates between a new synthetic tissue substitute (CorNeat EverPatch) with that of human donor cornea after placement onto the scleral surface during ophthalmic surgery and study the biomaterial properties of the synthetic patch material. Design: Retrospective comparison study and biomaterial analyses of new and explanted synthetic patch material. Participants: All consecutive patients who underwent ophthalmic surgery with implantation of the CorNeat EverPatch at the Wilmer Eye Institute (occurring from February through August 2024) and a comparison group who underwent ophthalmic surgery with implantation of irradiated donor cornea, matched 1:2 with patients receiving EverPatch for age, type of glaucoma, and surgeon. Methods: Retrospective review of clinical electronic medical records of patients who underwent surgery at the Wilmer Eye Institute. Materials characterization of EverPatch, including morphologic features, surface roughness, wettability, thermal stability, elemental analysis, and physical properties. Main Outcome Measures: Early exposure (within 5 months of surgery) and surgical revision rates after CorNeat EverPatch or irradiated human donor cornea implantation during ophthalmic surgery. Results: Thirty patients undergoing ophthalmic surgery in 2024 received EverPatch implantation during primary tube shunt placement (n = 27), tube shunt revision (n = 2), or covering of exposed suture used for scleral fixation of an intraocular lens (n = 1). During the early postoperative period, the rate of EverPatch exposure was 48.3% and the rate of surgical revision was 27.9%. In case-matched control participants (n = 58), the rate of patch graft exposure was 1.7% (P < 0.0001) and the rate of surgical revision was 1.7% (P < 0.0001). EverPatch devices constituted a randomly aligned fibrous mesh with an average fiber diameter of 1.36 ± 0.78 μm, surface roughness of 1.3 ± 0.1 μm, pore size of 3.7 ± 0.4 μm^2<

关键词： conjunctiva Electrospinning Glaucoma surgery Patch graft Tube shunt

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Addressing barriers to clinical translation of extracellular vesicle therapeutics

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Molecular therapy : the journal of the American Society of Gene Therapy 2025年第5期33卷 1879-1880页

作者： Steven M Jay Fischell Department of Bioengineering University of Maryland College Park MD 20742 USA Robert E. Fischell Institute for Biomedical Devices University of Maryland College Park MD USA Marlene and Stewart Greenebaum Comprehensive Cancer Center University of Maryland Medical Center Baltimore MD USA Program in Molecular and Cell Biology University of Maryland College Park MD 20742 USA. Electronic address: smjay@umd.edu.

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Creating an in vitro lung microenvironment via DNA-directed patterning to investigate the role of extracellular vesicles in metastasis 24

Creating an in vitro lung microenvironment via DNA-directed ...

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24th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2020

作者： Kitayama, Sean E. Sohn, Lydia L. UC Berkeley UCSF Graduate Program in Bioengineering BerkeleyCA United States Department of Mechanical Engineering University of California Berkeley BerkeleyCA United States

ISBN: (纸本)9781733419017

We present a novel in vitro heterogenous lung microenvironment fabricated using DNA-directed patterning, a lithographic method capable of controlled spatial and temporal presentation of cells and ligands with micron-scale precision. Designed using patient histology images, this alveolar microenvironment contains five cell types in an optimized co-culture system that has a number of advantages over existing in vivo models. Our optimized platform has the ability to answer questions about breast cancer metastasis, particularly about the role of extracellular vesicles in preparing the pre-metastatic niche in the secondary lung microenvironment. © 2020 CBMS-0001

关键词： Diseases

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Sustainable Next-generation Color Converters of P. harmala Seed Extracts for Solid-State Lighting

arXiv

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arXiv 2023年

作者： Erdem, Talha Orenc, Ali Akcan, Dilber Duman, Fatih Soran-Erdem, Zeliha Department of Electrical-Electronics Engineering Abdullah Gül University Kayseri Turkey Erciyes University Kayseri Turkey Bioengineering Graduate Program Abdullah Gül University Kayseri Turkey Department of Biology Erciyes University Kayseri Turkey Department of Engineering Sciences Abdullah Gül University Kayseri Turkey

Traditional solid-state lighting relies on color converters with a serious environmental footprint. As an alternative, natural materials such as plant extracts could be employed if their low quantum yield (QYs) in liquid and solid states were higher. With this motivation, here, we investigate the optical features of P. harmala extract in water, develop its efficient color-converting solids using a facile, sustainable, and low-cost method, and integrate it with a light-emitting diode. To obtain a high-efficiency solid host for the P. harmala-based fluorophores, we optically and structurally compared two crystalline and two cellulose-based platforms. Structural characterizations indicate that sucrose crystals, cellulose-based cotton, and paper platforms allow fluorophores to be distributed relatively homogenously as opposed to the KCl crystals. Optical characterizations reveal that the extracted solution and the extract-embedded paper possess QYs of 75.6% and 44.7%, respectively, whereas the QYs of the cotton, sucrose, and KCl crystals remain below 10%. Subsequently, as a proof-of-concept demonstration, we integrate the as-prepared efficient solid of P. harmala for the first time with a light-emitting diode (LED) chip to produce a color-converting LED. The resulting blue-emitting LED achieves a luminous efficiency of 21.9 lm/Welect with CIE color coordinates of (0.139,0.070). With these results, we bring plant-based fluorescent biomolecules to the stage of solid-state lighting. We believe that they hold great promise as next-generation, environmentally friendly organic color converters for lighting applications. © 2023, CC BY-NC-ND.

关键词： Color

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Resistant to Technology and Digital Banking Behavior Among Jakarta's Generation Z

Resistant to Technology and Digital Banking Behavior Among J...

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IT Innovation and Knowledge Discovery (ITIKD), International Conference on

作者： Michael Christian Henilia Yulita Yustinus Yuniarto Suryo Wibowo Eko Retno Indriyarti Sunarno Sunarno Management Universitas Bunda Mulia Jakarta Indonesia Communication Studies Universitas Bunda Mulia Jakarta Indonesia Biomedical and Bioengineering Indonesia International for Life Sciences Jakarta Indonesia Faculty of Economics and Business Universitas Trisakti Jakarta Indonesia Psychological Science Doctoral Program Universitas Persada Indonesia YAI Jakarta Indonesia

When sophisticated technology is integrated into digital banking services with the goal of providing customers with an easy, fast, safe, and enjoyable experience, then details about customer behavior when receiving services are based on this sophisticated technology. Therefore, the goal of this study is to investigate how ease of use, usefulness, security, and self-efficacy affect resistance to technology or behavior when using digital banks among Jakarta's generation Z. In this quantitative study, partial least-square structural equation modeling (PLS-SEM) is used. Specifically, SmartPLS 3.0 is used to analyze the data collected from 157 participants. According to the findings of this study, participants consider the factor of resistance to digital banking technology to be more important than the impact on usage behavior. Issues related to security are also an important factor for customers when using technology such as digital banking services. Notably, the limitation of this research is that it does not use aspects of the technology used in each digital banking service. Furthermore, comparing users from different generations can help to improve the findings of this study.

关键词： Resistance Technological innovation Banking Knowledge discovery Mathematical models Behavioral sciences Security

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Integrating cell confinement in a perfusion bioreactor improves iMSC extracellular vesicle production and potency

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Cytotherapy 2025年第5期27卷 S87-S88页

作者： E.H. Powsner K. Nikolov S.M. Jay Bioengineering University of Maryland College Park MD United States Program in Molecular Biology University of Maryland College Park MD United States

Background & Aim Mesenchymal stem cell extracellular vesicles (MSC EVs) have been reported to have broad therapeutic potential and are the most investigated EVs for therapeutic applications in clinical trials. However, the translational potential of MSC EVs is limited by MSC donor variability, EV potency, and lack of a versatile scalable manufacturing approach. Our group previously established that MSC EV potency can be improved via mechanoregulation – the exposure of producer MSCs to specific physical cues during EV generation. The goal of this project is to assess the potential of mechanoregulation, specifically cell confinement, to overcome donor variability issues and to be applied for large-scale EV production, thus presenting a potential solution to the most significant limitations to MSC EV translation. Methodology Since donor MSCs exhibit significant variability and limited expansion, we evaluated an alternative, renewable cell source; MSCs derived from induced pluripotent stem cells (iMSCs). iMSCs were seeded on 5 and 50 µm micropillar arrays fabricated via photolithography and polydimethylsiloxane molding. The isolated EVs were assessed for their mechanoresponsiveness and angiogenic effects via tube formation assay. Additionally, while confinement is a promising approach to improve potency, EV yield from static culture remains low. Therefore, we designed a 3D-printed bioreactor scaffold that can incorporate MSC confinement. Flow rate was optimized based on EV production/cell, protein/EV, and the EVs’ angiogenic and wound repair activity as measured by tube formation and gap closure assays, respectively. Results The level of tube formation by the EVs corresponded with increasing confinement, so we moved forward with iMSCs in the confinement bioreactor system. We determined that a 5 mL/min flow rate achieved a 48-fold increase and 1.09-fold decrease in EV/cell and protein/EV, respectively, compared to static confinement and a 67-fold increase and 2.14-fold d

关键词： Exosome Mesenchymal stem/stromal cell

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Sample Preconcentration Through Airjet-Induced Liquid Phase Enrichment

SSRN

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SSRN 2023年

作者： Wang, Edward Laurent, Louise C. Hall, Drew A. Lo, Yu-Hwa Department of Aerospace and Mechanical Engineering Materials Science and Engineering Program University of California La Jolla San DiegoCA United States Sanford Consortium of Regenerative Medicine United States Department of Electrical and Computer Engineering University of California La Jolla San DiegoCA United States Department of Bioengineering

Sample preparation is essential for nucleic acid assays, affecting their sensitivity and reliability. However, this process often results in a significant loss or dilution of the analyte, which becomes a bottleneck that limits downstream assay performance, particularly for assays that accept a limited input sample volume. To overcome this challenge, we present an evaporative-based sample enrichment method that uses an airjet to concentrate analytes within a small, defined volume by reversing the coffee-ring effect. A small, concentrated sample can then be collected for analysis to increase the initial sample load. The effectiveness of the reported airjet enrichment was quantified using qPCR of λ-DNA, HeLa-S3 RNA, and heat-inactivated SARS-CoV-2 samples. Comparisons between airjet enrichment and conventional evaporative concentration methods demonstrated significant advantages of airjet enrichment, including the ability to concentrate a high percentage of analyte within a 1 µL volume. The enrichment method was then integrated and adapted for various fluid volumes commonly found in nucleic acid sample preparation procedures. Here, airjet enrichment reduced the overall [[EQUATION]] by an average of 9.27 cycles for each analyte, resulting in a 600-fold enrichment from the initial concentration. In addition, to perform selective enrichment and prevent salt-based interference in downstream analysis, PEG was added to reduce the co-enrichment of salt. These studies show how airjet enrichment technology can be easily integrated into existing laboratory protocols with minimal modification and significantly improve the performance of nucleic acid amplification assays. © 2023, The Authors. All rights reserved.

关键词： Biomolecules

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The Impact of Cashless Payment in Application-Based Transportation on Gen Z User Behavior in Jakarta

The Impact of Cashless Payment in Application-Based Transpor...

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IT Innovation and Knowledge Discovery (ITIKD), International Conference on

作者： Michael Christian Henilia Yulita Lasmery RM Girsang Suryo Wibowo Eko Retno Indriyarti Sunarno Sunarno Management Universitas Bunda Mulia Jakarta Indonesia Communication Studies Universitas Bunda Mulia Jakarta Indonesia Biomedical and Bioengineering Indonesia International for Life Sciences Jakarta Indonesia Faculty of Economics and Business Universitas Trisakti Jakarta Indonesia Psychological Science Doctoral Program Universitas Persada Indonesia YAI Jakarta Indonesia

Many industrial sectors, including transportation, have seen a series of adjustments or changes because of technological advancements. The traditional mode of transportation, particularly on land, is now application-based. This provides several advantages, including flexibility, convenience, speed, and security. This is also influencing payment methods for these app-based transportation services. Transportation service providers, including one of them, continue to promote the use of this cashless method through promotion or a loyalty point program for service users. This is undeniably appealing to its users, particularly those born after the year 2000. The purpose of this study is to examine the behavior of users who switch to cashless payment methods and the impact on their behavior. Using SmartPLS 3.0 structural modeling and 120 participants in Jakarta, we used application-based transportation services from generation Z. According to the findings of this study, four hypotheses are accepted and three are rejected. This study specifically explains that switching costs have a significant impact on switching decisions. Furthermore, this study demonstrates that the decision to switch has a significant impact on user satisfaction. User satisfaction is significantly influenced by attitude promotion. According to the study's other findings, attitude toward promotion does not moderate the effect of switching costs on switching decisions. The limitations of this study stem from the use of variables that only use transitional forming factors, and satisfaction is based solely on attitude variables and transitional drivers from the promotion aspect. Meanwhile, other variables such as price competition from application-based transportation service providers or the number of competitors may have a different impact, enriching the study's findings. Another suggestion for future research is to cover research areas with sample sizes from different generations.

关键词： Technological innovation Costs Shape Transportation Switches Knowledge discovery Behavioral sciences

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