Molecular diffusion analysis of dynamic blood flow and plasma separation driven by self-powered microfluidic devices     

Sung Oh Woo  Myungkeun Oh  Kyle Nietfeld  Bailey Boehler  Yongki Choi 《Biomicrofluidics》2021,15(3)

Integration of microfluidic devices with pressure-driven, self-powered fluid flow propulsion methods has provided a very effective solution for on-chip, droplet blood testing applications. However, precise understanding of the physical process governing fluid dynamics in polydimethylsiloxane (PDMS)-based microfluidic devices remains unclear. Here, we propose a pressure-driven diffusion model using Fick''s law and the ideal gas law, the results of which agree well with the experimental fluid dynamics observed in our vacuum pocket-assisted, self-powered microfluidic devices. Notably, this model enables us to precisely tune the flow rate by adjusting two geometrical parameters of the vacuum pocket. By linking the self-powered fluid flow propulsion method to the sedimentation, we also show that direct plasma separation from a drop of whole blood can be achieved using only a simple construction without the need for external power sources, connectors, or a complex operational procedure. Finally, the potential of the vacuum pocket, along with a removable vacuum battery to be integrated with non-PDMS microfluidic devices to drive and control the fluid flow, is demonstrated.  相似文献   

Effects of purposeful soccer heading on circulating small extracellular vesicle concentration and cargo     

Eric R. Muoz  Jaclyn B. Caccese  Brittany E. Wilson  Kyle T. Shuler  Fernando V. Santos  Carolina T. Cabn  John J. Jeka  Dianne Langford  Matthew B. Hudson 《运动与健康科学(英文)》2021,10(2):122

BackgroundConsidering the potential cumulative effects of repetitive head impact (HI) exposure, we need sensitive biomarkers to track short- and long-term effects. Circulating small extracellular vesicles (sEVs) (<200 nm) traffic biological molecules throughout the body and may have diagnostic value as biomarkers for disease. The purpose of this study was to identify the microRNA (miRNA) profile in circulating sEVs derived from human plasma following repetitive HI exposure.MethodsHealthy adult (aged 18–35 years) soccer players were randomly assigned to one of 3 groups: the HI group performed 10 standing headers, the leg impact group performed 10 soccer ball trapping maneuvers over 10 min, and the control group did not participate in any soccer drills. Plasma was collected before testing and 24 h afterward, and sEVs were isolated and characterized via nanoparticle tracking analysis. Next-generation sequencing was utilized to identify candidate miRNAs isolated from sEVs, and candidate microRNAs were analyzed via quantitative polymerase chain reaction. In silico target prediction was performed using TargetScan (Version 7.0; targetscan.org) and miRWalk (http://mirwalk.umm.uni-heidelberg.de/) programs, and target validation was performed using luciferase reporter vectors with a miR-7844-5p mimic in human embryonic kidney (HEK) 293T/17 cells.ResultsPlasma sEV concentration and size were not affected across time and group following repetitive HI exposure. After 24 h, the HI read count from next-generation sequencing showed a 4-fold or greater increase in miR-92b-5p, miR-423-5p, and miR-24-3p and a 3-fold or greater decrease in miR-7844-5p, miR-144-5p, miR-221-5p, and miR-22-3p. Analysis of quantitative polymerase chain reaction revealed that leg impact did not alter the candidate miRNA levels. To our knowledge, miR-7844-5p is a previously unknown miRNA. We identified 8 miR-7844-5p mRNA targets: protein phosphatase 1 regulatory inhibitor subunit 1B (PPP1R1B), LIM and senescent cell antigen-like domains 1 (LIMS1), autophagy-related 12 (ATG12), microtubule-associated protein 1 light chain 3 beta (MAP1LC3B), integrin subunit alpha-1 (ITGA1), mitogen-activated protein kinase 1 (MAPK1), glycogen synthase kinase 3β (GSK3β), and mitogen-activated protein kinase 8 (MAPK8).ConclusionCollectively, these data indicate repetitive HI exposure alters plasma sEV miRNA content, but not sEV size or number. Furthermore, for the first time we demonstrate that previously unknown miR-7844-5p targets mRNAs known to be involved in mitochondrial apoptosis, autophagy regulation, mood disorders, and neurodegenerative disease.  相似文献   

Attributes and Frames of the Aurora Shootings     

Kyle J. Holody  Emory S. Daniel 《Journalism Practice》2017,11(1):80-100

The present study examined frames and second-level agenda-setting attributes used by national and local newspapers to cover the 2012 Aurora, Colorado shootings. Unlike research examining coverage of school shootings, this study examined a mass shooting that did not occur at a school. Both newspaper types published a similar number of articles—though national articles tended to be longer—and virtually stopped coverage after 18 days. While previous coverage tended to focus on shootings’ societal implications, Aurora coverage focused more on individuals involved in the time immediately surrounding the shootings. National papers focused on the gunman, while the local press tended to focus on victims. Mass shootings in general tend to be salient news items, but the present study further shows news outlets may now focus on incidents’ specifics instead of common characteristics they might share, perhaps because audiences have an existing understanding of them. The shootings were framed in terms of gun control; national newspapers used this frame more often than did local newspapers. Both newspaper types tended to discuss gun control as directly related to the Aurora shootings, rather than as a societal or continuing need. Results offer further evidence that second-level agenda-setting and framing are distinct concepts.  相似文献   

Education for the knowledge to teach mathematics: it all has to come together     

Peter Sullivan 《Journal of Mathematics Teacher Education》2008,11(6):431-433

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The Relationship Between Retention and College Counseling for High‐Risk Students     

Kyle K. Bishop 《Journal of College Counseling》2016,19(3):205-217

The author used an archival study to explore the relationship between college counseling and retention. The cohort for this study was a college's 2006 class of full‐time, 1st‐year students (N = 429). The results of chi‐square analyses and regression analyses indicated (a) a significant difference in retention between high‐risk and low‐risk students who used counseling services (CS) and (b) that a student's risk for dropout did not vary significantly over time based on risk level or CS use.  相似文献   

Advancing virtual patient simulations through design research and interPLAY: part I: design and development     

Atsusi Hirumi  Andrea Kleinsmith  Kyle Johnsen  Stacey Kubovec  Michael Eakins  Kenneth Bogert  Diego J. Rivera-Gutierrez  Ramsamooj Javier Reyes  Benjamin Lok  Juan Cendan 《Educational technology research and development : ETR & D》2016,64(4):763-785

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Toddlers learn and flexibly apply multiple possibilities     

Mariel K. Goddu  J. Nicholas Sullivan  Caren M. Walker 《Child development》2021,92(6):2244-2251

The ability to consider multiple possibilities forms the basis for a wide variety of human-unique cognitive capacities. When does this skill develop? Previous studies have narrowly focused on children's ability to prepare for incompatible future outcomes. Here, we investigate this capacity in a causal learning context. Adults (N = 109) and 18- to 30-month olds (N = 104) observed evidence that was consistent with two hypotheses, each occupying a different level of abstraction (individual vs. relational causation). Results suggest that adults and toddlers identified multiple candidate causes for an effect, held these possibilities in mind, and flexibly applied the appropriate hypothesis to inform subsequent inferences. These findings challenge previous suggestions that the ability to consider multiple alternatives does not emerge until much later in development.  相似文献   

How morphology impacts reading and spelling: advancing the role of morphology in models of literacy development     

Kyle C. Levesque  Helen L. Breadmore  S. Hlne Deacon 《Journal of Research in Reading》2021,44(1):10-26

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The relationship between child behaviour problems at school entrance and teenage vocabulary acquisition: A comparison of two generations of British children born 30 years apart     

Sam Parsons  Alice Sullivan  Vanessa Moulton  Emla Fitzsimons  George B. Ploubidis 《British Educational Research Journal》2021,47(5):1361-1387

Behaviour problems in early childhood have a lasting impact on cognitive development and education attainment in later adolescence and into adulthood. Here we address the relationship conduct and hyperactivity problems at school entrance, and vocabulary acquisition in adolescence. We compare performance in identical assessments across two generations of British children born 30 years apart in 1970 (n = 15,676) and 2000/2 (n = 16,628) and find that both conduct and hyperactivity problems have a negative association with later vocabulary in both generations. We take advantage of rich longitudinal birth cohort data and establish that these relationships hold once family socioeconomic status and a child’s personal characteristics and earlier vocabulary acquisition are taken into account. We also find that teenagers today achieved substantively lower scores in the vocabulary assessment compared to their counterparts born 30 years earlier, and that this holds across all categories within each of the family and individual characteristics considered in this article. As vocabulary and language skills are key prerequisites for wider learning, we discuss implications the findings have for education policies.  相似文献   

A developmental study of the relationship between conceptual, ego, and moral development     

E V Sullivan  G McCullough  M Stager 《Child development》1970,41(2):399-411

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