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Modeling gut neuro-epithelial connections in a novel microfluidic device

Microsystems & Nanoengineering 2023年第6期9卷 235-246页

作者： Jose M.de Hoyos-Vega Xi Yu Alan M.Gonzalez-Suarez Sisi Chen Arnaldo Mercado-Perez Eugene Krueger Jeric Hernandez Yaroslav Fedyshyn Brooke r.Druliner david r.linden Arthur Beyder Alexander revzin Department of Physiology and Biomedical Engineering Mayo ClinicRochesterMNUSA Enteric Neuroscience Program(ENSP) Mayo ClinicRochesterMNUSA Division of Gastroenterology and Hepatology Department of MedicineMayo ClinicRochesterMNUSA

The intestinal lumen is filled with diverse chemical and physical stimuli.Intestinal epithelial cells sense these stimuli and signal to enteric neurons which coordinate a range of physiologic processes required for normal digestive tract function.Yet,the neuro-epithelial connections remain poorly resolved,in part because the tools for orchestrating interactions between these cellular compartments are lacking.We describe the development of a two-compartment microfluidic device for co-culturing enteric neurons with intestinal epithelial cells.The device contains epithelial and neuronal compartments connected by microgrooves.The epithelial compartment was designed for cell seeding via injection and confinement of intestinal epithelial cells derived from human intestinal organoids.We demonstrated that organoids planarized effectively and retained epithelial phenotype for over a week.In the second chamber we dissociated and cultured intestinal myenteric neurons including intrinsic primary afferent neurons(IPANs)from transgenic mice that expressed the fluorescent protein tdTomato.IPANs extended projections into microgrooves,surrounded and frequently made contacts with epithelial cells.The density and directionality of neuronal projections were enhanced by the presence of epithelial cells in the adjacent compartment.Our microfluidic device represents a platform that may,in the future,be used to dissect structure and function of neuro-epithelial connections in the gut and other organs(skin,lung,bladder,and others)in health and disease.

关键词： fluid bladder organs

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reflections on four decades of physical activity epidemiology

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Journal of Sport and Health Science 2024年第5期13卷 608-610页

作者： Barbara Sternfeld david r.Jacobs Jr. Division of research Kaiser Permanente Northern CaliforniaOaklandCA 94610USA Division of Epidemiology and Community Health School of Public HealthUniversity of MinnesotaMinneapolisMN 55454USA

In 1985,Public Health reports published a series of papers prepared for a workshop sponsored by the Centers for Disease Control and Prevention(CDC).1 Building on the seminal work of Jeremy Morris and ralph Paffenbarger Jr.,who were among the first to use epidemiological methods to study physical activity(PA),2,3 the workshop itself was the result of a growing scientific understanding of the importance of“physical fitness and exercise for improving the health of the public”.

关键词： semi workshop ralph

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Soil security and global food security

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Frontiers of Agricultural Science and Engineering 2024年第2期11卷 297-302页

作者： david r.MONTGOMErY Department of Earth and Space Sciences University of Washington townSeattleWA 98105USA

Over the course of the postglacial period has managed to add degrade a substantial portion of the world's potential agricultural land. The soil loss and degradation that has repeatedly impacted regional societies around the world resulted from agricultural practices that increased the physical loss of soil(erosion), reduced soil organic matter, changed p H(acidification) or salinity,and disrupted or altered communities of soil life. In the coming century, as continued soil degradation threatens global food security while the global population keeps rising it is imperative that farmers develop and adopt soilhealth building(regenerative) practices to solve a problem that has plagued societies throughout history. Growing evidence suggests that agricultural systems that combine cover crops, reduced tillage, and diverse crop rotations can reduce erosion, enhance soil health and rebuild soil organic matter to cultivate beneficial soil life and harvest both economic and environmental benefits. In the coming post-oil world, global food security would benefit from a global effort to promote soil restoration to help addresses the challenge of sustainably feeding the world, increase soil-based carbon sequestration,protect on-farm biodiversity and reduce off-farm water pollution. Because soil security sets a solid foundation for global food security, agricultural policies and subsidies should be reformed to encourage farmers to adopt regenerative,soil-building practices.

关键词： Agriculture soil security food security regenerative

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Single-atom Pt on carbon nanotubes for selective electrocatalysis

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Carbon Energy 2024年第1期6卷 63-71页

作者： Samuel S.Hardisty Xiaoqian Lin Anthony r.J.Kucernak david Zitoun Department of Chemistry Bar Ilan Institute of Nanotechnology and Advanced Materials(BINA)Bar Ilan UniversityRamat GanIsrael Department of Chemistry Molecular Science Research HubImperial College LondonLondonUK

Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOr).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox reaction.Characterizations via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the Pt.The electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the electrocatalyst.The single-atom samples showed higher HOr activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating range.The selective activity toward HOr arose as the main fingerprint of the catalyst confinement in the SWCNTs.

关键词： confinement electrocatalysis hydrogen platinum single atom catalysts

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Late Ordovician Mass Extinction: Earth, fire and ice

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National Science review 2024年第1期11卷 51-65页

作者： david A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science review 2024年第1期11卷 8-10页

作者： david J.Bottjer Department of Earth Sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Exercise immunology:Novel insights

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Journal of Sport and Health Science 2024年第3期13卷 277-279,I0001页

作者： david C.Nieman Human Performance Laboratory Appalachian State UniversityNorth Carolina Research CampusKannapolisNC 28081USA

The coronavirus disease 2019(COVID-19)pandemic heightened worldwide attention on the influence of exercise on the immune system.Questions were raised about whether regular moderate-to-vigorous physical activity(MVPA)could help prevent COVID-19 or mitigate symptoms when ill.Could MVPA bolster immunity among those most prone to COVID-19 including the elderly,obese,and immunocompromised patients?Does regular MVPA dampen systemic inflammation,thereby lessening the COVID-19 cytokine storm?

关键词： immunity inflammation thereby

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One-dimensional monotone nonautonomous dynamical systems

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Science China Mathematics 2024年第2期67卷 281-314页

作者： david Cheban Faculty of Mathematics and Computer Science Laboratory of Fundamental and Applied MathematicsMoldova State UniversityChisinau 2009Moldova

This work is devoted to the study of the dynamics of one-dimensional monotone nonautonomous(cocycle) dynamical systems. A description of the structures of their invariant sets, omega limit sets,Bohr/Levitan almost periodic and almost automorphic motions, global attractors, and pinched and minimalsets is given. An application of our general results is given to scalar differential and difference equations.

关键词： one-dimensional dynamics pinched and minimal sets global attractors monotone nonautonomous cocycle almost periodic solutions scalar differential/difference equations

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Kerogen Kinetic Distributions and Simulations Provide Insights into Petroleum Transformation Fraction (TF) Profiles of Organic-rich Shales

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Journal of Earth Science 2024年第3期35卷 747-757页

作者： david A.Wood DWA Energy Limited Lincoln LN59JPUnited Kingdom

Two hundred and fifty single first-order Arrhenius reactions are simulated to generate S2 pyrograms at three heating rates 25,15,and 5°C·min-1.The activation energy(E)and pre-exponential factor(A)of the reactions simulated follow a long-established trend of those variable values displayed by shales and kerogens.The characteristics of the transformation fraction(TF)profiles(product generation window temperatures)of the simulated single reactions are compared to the TF profiles of recorded shale pyrograms generated by multiple reactions with different E-A values lying near the defined E-A trend.Important similarities and differences are observed between the TF profile values of the two datasets.The similarities support the spread of E-A values involved in shale pyrogram best fits.The differences are most likely explained by the complexity of the multiple kerogen first-order and second-order reactions contributing to the recorded shale pyrograms versus the simplicity and crispness of the single first-order reactions simulated.The results also justify the validity of using the previously described“variable E-A pyrogram-fitting method”of multi-heating-rate shale pyrograms enabling optimizers to choose multiple reactions from an unlimited range of E-A values.In contrast,further doubt is cast on the validity of the constant-A pyrogram-fitting method used by the Easy%ro technique,in that a distribution of reactions with a single A value is unlikely to represent the complex variety of kerogen macerals observed in shale formations.TF profiles generated by the variable E-A pyrogram-fitting method lie close to the established E-A trend and are likely to provide more realistic TF generation window temperatures than TF profiles generated by the constant-A pyrogram-fitting method.

关键词： transformation fraction profiles simulated S2 pyrograms multiple heating rates kerogen/shale kinetics S2 pyrogram fitting techniques kerogen petroleum research.

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A brief history of the Compendium of Physical Activities

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Journal of Sport and Health Science 2024年第1期13卷 3-5页

作者： Barbara E.Ainsworth Stephen D.Herrmann david r.Jacobs Jr. Melicia C.Whitt-Glover Catrine Tudor-Locke School of Exercise and Health Shanghai University of SportShanghai 200438China College of Health Solutions Arizona State UniversityPhoenixAZ 85003USA Kansas Center for Metabolism and Obesity research University of Kansas Medical CenterKansas CityKS 66160USA Division of Epidemiology and Community Health University of MinnesotaMinneapolisMN 55455USA Gramercy research Group KnightdaleNC 27545USA College of Health and Human Services University of North Carolina at CharlotteCharlotteNC 28223USA

The Compendium of Physical Activities(Compendium)was developed to address consistent assignment of physical activity(PA)intensity values used in PA epidemiology research of the association between PA and health outcomes.1The known protective effects of PA on incident health outcomes traces to the mid-1900s,with over 50 studies examining coronary heart disease(CHD)as the outcome of interest.

关键词： epidemiology Activities protective

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