Volumetric lattice Boltzmann method for pore-scale mass diffusionadvection process in geopolymer porous structures

Porous materials present significant advantages for absorbing radioactive isotopes in nuclear waste streams.To improve absorption efficiency in nuclear waste treatment,a thorough understanding of the diffusion-advection process within porous structures is essential for material design.In this study,we present advancements in the volumetric lattice Boltzmann method(VLBM)for modeling and simulating pore-scale diffusion-advection of radioactive isotopes within geopolymer porous structures.These structures are created using the phase field method(PFM)to precisely control pore architectures.In our VLBM approach,we introduce a concentration field of an isotope seamlessly coupled with the velocity field and solve it by the time evolution of its particle population function.To address the computational intensity inherent in the coupled lattice Boltzmann equations for velocity and concentration fields,we implement graphics processing unit(GPU)parallelization.Validation of the developed model involves examining the flow and diffusion fields in porous structures.Remarkably,good agreement is observed for both the velocity field from VLBM and multiphysics object-oriented simulation environment(MOOSE),and the concentration field from VLBM and the finite difference method(FDM).Furthermore,we investigate the effects of background flow,species diffusivity,and porosity on the diffusion-advection behavior by varying the background flow velocity,diffusion coefficient,and pore volume fraction,respectively.Notably,all three parameters exert an influence on the diffusion-advection process.Increased background flow and diffusivity markedly accelerate the process due to increased advection intensity and enhanced diffusion capability,respectively.Conversely,increasing the porosity has a less significant effect,causing a slight slowdown of the diffusion-advection process due to the expanded pore volume.This comprehensive parametric study provides valuable insights into the kinetics of isotope uptake in porous structures,facilitating the development of porous materials for nuclear waste treatment applications.

Liquefaction susceptibility and deformation characteristics of saturated coral sandy soils subjected to cyclic loadings-a critical review

Coral sandy soils widely exist in coral island reefs and seashores in tropical and subtropical regions.Due to the unique marine depositional environment of coral sandy soils,the engineering characteristics and responses of these soils subjected to monotonic and cyclic loadings have been a subject of intense interest among the geotechnical and earthquake engineering communities.This paper critically reviews the progress of experimental investigations on the undrained behavior of coral sandy soils under monotonic and cyclic loadings over the last three decades.The focus of coverage includes the contractive-dilative behavior,the pattern of excess pore-water pressure(EPWP)generation and the liquefaction mechanism and liquefaction resistance,the small-strain shear modulus and strain-dependent shear modulus and damping,the cyclic softening feature,and the anisotropic characteristics of undrained responses of saturated coral sandy soils.In particular,the advances made in the past decades are reviewed from the following aspects:(1)the characterization of factors that impact the mechanism and patterns of EPWP build-up;(2)the identification of liquefaction triggering in terms of the apparent viscosity and the average flow coefficient;(3)the establishment of the invariable form of strain-based,stress-based,or energy-based EPWP ratio formulas and the unique relationship between the new proxy of liquefaction resistance and the number of cycles required to reach liquefaction;(4)the establishment of the invariable form of the predictive formulas of small strain modulus and strain-dependent shear modulus;and(5)the investigation on the effects of stress-induced anisotropy on liquefaction susceptibility and dynamic deformation characteristics.Insights gained through the critical review of these advances in the past decades offer a perspective for future research to further resolve the fundamental issues concerning the liquefaction mechanism and responses of coral sandy sites subjected to cyclic loadings associated with seismic events in marine environments.

Global prevalence and gender inequalities in at least 60 min of self-reported moderate-to-vigorous physical activity 1 or more days per week:An analysis with 707,616 adolescents

Background:Guidelines recommend that adolescents should accumulate an average of 60 min per day of moderate-to-vigorous physical activity(MVPA).However,using only this cut-off could hide important information.For instance,from a population-level point of view,increasing physical activity for those with no or low physical activity could provide more health benefits than increasing physical activity for those with intermediate levels.Also,including a more sensitive cut-point of≥1 days per week could be an additional strategy for identifying those with low access/opportunities for physical activity practice.Thus,the current study aims to estimate the prevalence of≥60 min of MVPA≥1 days per week among adolescents globally,and to describe any relevant gender inequalities.Methods:We used representative datasets from 146 countries/territories collected between 2003 and 2019.MVPA was self-reported.Participants were grouped into younger(≤14 years old)and older(>14 years old)adolescents.Crude Poisson regression models were used to identify the relative differences in≥60 min of MVPA≥1 days per week between boys and girls,and random-effects meta-analysis models were used to identify the pooled estimates.Analyses were stratified by country and region.Results:Approximately 80%of both younger and older adolescents reported≥60 min of MVPA≥1 days per week.This prevalence was≥94%in Europe and Central Asia and North America,while the estimates for the other regions were<77%.The prevalence of≥60 min of MVPA≥1 days per week was higher among boys than girls,with the largest differences occurring among the oldest adolescents(Prevalence ratio_(≤14y)=1.04(95%confidence interval(95%CI)):1.03-1.04)vs.Prevalence ratio_(>14y)=1.09(95%CI:1.08-1.10)).Conclusion:Approximately 8 out of 10 adolescents reported accumulating≥60 min of MVPA≥1 days per week,with notable differences between regions.Gender differences were observed in several countries,especially among the oldest adolescents.Priorities for physical activity promotion among adolescents should include increasing access/opportunities for physical activity among those who do not achieve≥60 min of MVPA≥1 days per week and reducing gender inequalities.

Engineering Nano/Microscale Chiral Self‑Assembly in 3D Printed Constructs

Helical hierarchy found in biomolecules like cellulose,chitin,and collagen underpins the remarkable mechanical strength and vibrant colors observed in living organisms.This study advances the integration of helical/chiral assembly and 3D printing technology,providing precise spatial control over chiral nano/microstructures of rod-shaped colloidal nanoparticles in intricate geometries.We designed reactive chiral inks based on cellulose nanocrystal(CNC)suspensions and acrylamide monomers,enabling the chiral assembly at nano/microscale,beyond the resolution seen in printed materials.We employed a range of complementary techniques including Orthogonal Superposition rheometry and in situ rheo-optic measurements under steady shear rate conditions.These techniques help us to understand the nature of the nonlinear flow behavior of the chiral inks,and directly probe the flow-induced microstructural dynamics and phase transitions at constant shear rates,as well as their post-flow relaxation.Furthermore,we analyzed the photo-curing process to identify key parameters affecting gelation kinetics and structural integrity of the printed object within the supporting bath.These insights into the interplay between the chiral inks self-assembly dynamics,3D printing flow kinematics and photopolymerization kinetics provide a roadmap to direct the out-of-equilibrium arrangement of CNC particles in the 3D printed filaments,ranging from uniform nematic to 3D concentric chiral structures with controlled pitch length,as well as random orientation of chiral domains.Our biomimetic approach can pave the way for the creation of materials with superior mechanical properties or programable photonic responses that arise from 3D nano/microstructure and can be translated into larger scale 3D printed designs.

Generative AI for Materials Discovery:Design Without Understanding

1.Design as building-block assembling In the 21st century,society is facing several fundamental challenges,including global climate change,the energy crisis,and public health crises such as cancers and coronavirus disease 2019(COVID-19).Their solutions share a certain commonality:They all involve the discovery of novel atomic structures such as materials,molecules,proteins,and drugs.Designing such functional atomic structures is challenging due to the astonishing complexity of their inter-atomic interactions,sophisticated physical/chemical/geometric constraints and patterns in the formation of stable structures,and the relation between structures and their functions.

The electrical design of a membrane antenna for a lunar-based low-frequency radio telescope

Detecting primordial fluctuations from the cosmic dark ages requires extremely large low-frequency radio telescope arrays deployed on the far side of the Moon.The antenna of such an array must be lightweight,easily storable and transportable,deployable on a large scale,durable,and capable of good electrical performance.A membrane antenna is an excellent candidate to meet these criteria.We study the design of a low-frequency membrane antenna for a lunar-based low-frequency(<30 MHz)radio telescope constructed from polyimide film widely used in aerospace applications,owing to its excellent dielectric properties and high stability as a substrate material.We first design and optimize an antenna in free space through dipole deformation and coupling principles,then simulate an antenna on the lunar surface with a simple lunar soil model,yielding an efficiency greater than 90%in the range of 12-19 MHz and greater than 10%in the range of 5-35 MHz.The antenna inherits the omni-directional radiation pattern of a simple dipole antenna in the 5-30 MHz frequency band,giving a large field of view and allowing detection of the 21 cm global signal when used alone.A demonstration prototype is constructed,and its measured electrical property is found to be consistent with simulated results using|S11|measurements.This membrane antenna can potentially fulfill the requirements of a lunar low-frequency array,establishing a solid technical foundation for future large-scale arrays for exploring the cosmic dark ages.

Clemastine in remyelination and protection of neurons and skeletal muscle after spinal cord injury

Spinal cord injuries affect nearly five to ten individuals per million every year. Spinal cord injury causes damage to the nerves, muscles, and the tissue surrounding the spinal cord. Depending on the severity, spinal injuries are linked to degeneration of axons and myelin, resulting in neuronal impairment and skeletal muscle weakness and atrophy. The protection of neurons and promotion of myelin regeneration during spinal cord injury is important for recovery of function following spinal cord injury. Current treatments have little to no effect on spinal cord injury and neurogenic muscle loss. Clemastine, an Food and Drug Administration-approved antihistamine drug, reduces inflammation, protects cells, promotes remyelination, and preserves myelin integrity. Recent clinical evidence suggests that clemastine can decrease the loss of axons after spinal cord injury, stimulating the differentiation of oligodendrocyte progenitor cells into mature oligodendrocytes that are capable of myelination. While clemastine can aid not only in the remyelination and preservation of myelin sheath integrity, it also protects neurons. However, its role in neurogenic muscle loss remains unclear. This review discusses the pathophysiology of spinal cord injury, and the role of clemastine in the protection of neurons, myelin, and axons as well as attenuation of skeletal muscle loss following spinal cord injury.

Comparison of point detection and area detection for point-scanning structured illumination microscopy

Structured illumination microscopy(SIM)is suitable for biological samples because of its relatively low-peak illumination intensity requirement and high imaging speed.The system resolution is affected by two typical detection modes:Point detection and area detection.However,a systematic analysis of the imaging performance of the different detection modes of the system has rarely been conducted.In this study,we compared laser point scanning point detection(PS-PD)and point scanning area detection(PS-AD)imaging in nonconfocal microscopy through theoretical analysis and simulated imaging.The results revealed that the imaging resolutions of PSPD and PS-AD depend on excitation and emission point spread functions(PSFs),respectively.Especially,we combined the second harmonic generation(SHG)of point detection(P-SHG)and area detection(A-SHG)with SIM to realize a nonlinear SIM-imaging technique that improves the imaging resolution.Moreover,we analytically and experimentally compared the nonlinear SIM performance of P-SHG with that of A-SHG.

Whole‑genome transcriptome and DNA methylation dynamics of pre‑implantation embryos reveal progression of embryonic genome activation in buffaloes

Background During mammalian pre-implantation embryonic development(PED),the process of maternal-to-zygote transition(MZT)is well orchestrated by epigenetic modification and gene sequential expression,and it is related to the embryonic genome activation(EGA).During MZT,the embryos are sensitive to the environment and easy to arrest at this stage in vitro.However,the timing and regulation mechanism of EGA in buffaloes remain obscure.Results Buffalo pre-implantation embryos were subjected to trace cell based RNA-seq and whole-genome bisulfite sequencing(WGBS)to draw landscapes of transcription and DNA-methylation.Four typical developmental steps were classified during buffalo PED.Buffalo major EGA was identified at the 16-cell stage by the comprehensive analy-sis of gene expression and DNA methylation dynamics.By weighted gene co-expression network analysis,stage-spe-cific modules were identified during buffalo maternal-to-zygotic transition,and key signaling pathways and biological process events were further revealed.Programmed and continuous activation of these pathways was necessary for success of buffalo EGA.In addition,the hub gene,CDK1,was identified to play a critical role in buffalo EGA.Conclusions Our study provides a landscape of transcription and DNA methylation in buffalo PED and reveals deeply the molecular mechanism of the buffalo EGA and genetic programming during buffalo MZT.It will lay a foundation for improving the in vitro development of buffalo embryos.

Celiac disease screening in patients with cryptogenic cirrhosis

We write a letter to the editor commenting the article“Who to screen and how to screen for celiac disease”.We discuss the present literature on cirrhosis and celiac disease(CD)and recommend screening and treating CD in individuals with cryptogenic cirrhosis.

Improvement in Resolution of Multiphoton Scanning Structured Illumination Microscopy via Harmonics

We describe a multiphoton(mP)-structured illumination microscopy(SIM)technique,which demonstrates substantial improvement in image resolution compared with linear SIM due to the nonlinear response of fluorescence.This nonlinear response is caused by the effect of nonsinusoidal structured illumination created by scanning a sinusoidally modulated illumination to excite an mP fluorescence signal.The harmonics of the structured fluorescence illumination are utilised to improve resolution.We present an mP-SIM theory for reconstructing the super-resolution image of the system.Theoretically,the resolution of our m P-SIM is unlimited if all the high-order harmonics of the nonlinear response of fluorescence are considered.Experimentally,we demonstrate an 86 nm lateral resolution for two-photon(2P)-SIM and a 72 nm lateral resolution for second-harmonic-generation(SHG)-SIM.We further demonstrate their application by imaging cells stained with F-actin and collagen fibres in mouse-tail tendon.Our method can be directly used in commercial mP microscopes and requires no specific fluorophores or high-intensity laser.

Prevention of macrovascular complications in patients with type 2 diabetes mellitus: Review of cardiovascular safety and efficacy of newer diabetes medications

Lack of conclusive beneficial effects of strict glycemic control on macrovascular complications has been very frustrating for clinicians involved in care of patients with diabetes mellitus (DM). Highly publicized controversy surrounding cardiovascular (CV) safety of rosiglitazone resulted in major changes in United States Food and Drug Administration policy in 2008 regarding approval process of new antidiabetic medications, which has resulted in revolutionary data from several large CV outcome trials over the last few years. All drugs in glucagon-like peptide-1 receptor agonist (GLP-1 RA) and sodium-glucose cotransporter-2 (SGLT-2) inhibitor classes have shown to be CV safe with heterogeneous results on CV efficacy. Given twofold higher CV disease mortality in patients with DM than without DM, GLP-1 RAs and SGLT-2-inhibitors are important additions to clinician’s armamentarium and should be second line-therapy particularly in patients with T2DM and established atherosclerotic CV disease or high risks for CV disease. Abundance of data and heterogeneity in CV outcome trials results can make it difficult for clinicians, particularly primary care physicians, to stay updated with all the recent evidence. The scope of this comprehensive review will focus on all major CV outcome studies evaluating CV safety and efficacy of GLP-1 RAs and SGLT-2 inhibitors.

Endoscopic balloon dilation for management of stricturing Crohn’s disease in children

BACKGROUND Crohn’s disease(CD)has a multitude of complications including intestinal strictures from fibrostenotic disease.Fibrostenotic disease has been reported in 10%-17%of children at presentation and leads to surgery in 20%-50%of cases within ten years of diagnosis.When symptoms develop from these strictures,the treatment in children has primarily been surgical resection.Endoscopic balloon dilation(EBD)has been shown to be a safe and efficacious alternative to surgery in adults,but evidence is poor in the literature regarding its safety and efficacy in children.AIM To evaluate the outcomes of children with fibrostenosing CD who underwent EBD vs surgery as a treatment.METHODS In a single-center retrospective study,we looked at pediatric patients(ages 0-18)who carry the diagnosis of CD,who were diagnosed after opening a dedicated Inflammatory Bowel Disease clinic on July 1,2012 through May 1,2019.We used diagnostic codes through our electronic medical record to identify patients with CD with a stricturing phenotype.The type of intervention for patients’strictures was then identified through procedural and surgical billing codes.We evaluated their demographics,clinical variables,whether they underwent EBD vs surgery or both,and their clinical outcomes.RESULTS Of the 139 patients with CD,25(18%)developed strictures.The initial intervention for a stricture was surgical resection in 12 patients(48%)and EBD in 13 patients(52%).However,4(33%)patients whom initially had surgical resection required follow up EBD,and thus 17 total patients(68%)underwent EBD at some point in their treatment process.For those 8 patients who underwent successful surgical resection alone,4 of these patients(50%)had a fistula present near the stricture site and 4(50%)had strictures greater than 5 cm in length.All patients who underwent EBD had no procedural complications,such as a perforation.Twenty-two(88%)of the treated strictures were successfully managed by EBD and did not require any further surgical intervention during our follow up period.CONCLUSION EBD is safe and efficacious as an alternative to surgery for palliative management of strictures in selected pediatric patients with CD.

Influences of the NAO on the North Atlantic CO2 Fluxes in Winter and Summer on the Interannual Scale

The differences in the influences of the North Atlantic Oscillation (NAO) on the air–sea CO2 fluxes (fCO2) in the North Atlantic (NA) between different seasons and between different regions are rarely fully investigated. We used observation-based data of fCO2, surface-ocean CO2 partial pressure (pCO2sea), wind speed and sea surface temperature (SST) to analyze the relationship between the NAO and fCO2 of the subtropical and subpolar NA in winter and summer on the interannual time scale. Based on power spectrum estimation, there are significant interannual signs with a 2–6 year cycle in the NAO indexes and area-averaged fCO2 anomalies in winter and summer from 1980 to 2015. Regression analysis with the 2–6 year filtered data shows that on the interannual scale the response of the fCO2 anomalies to the NAO has an obvious meridional wave-train-like pattern in winter, but a zonal distribution in summer. This seasonal difference is because in winter the fCO2 anomalies are mainly controlled by the NAO-driven wind speed anomalies, which have a meridional distribution pattern, while in summer they are dominated by the NAO-driven SST anomalies, which show distinct zonal difference in the subtropical NA. In addition, in the same season, there are different factors controlling the variation of pCO2sea in different regions. In summer, SST is important to the interannual variation of pCO2sea in the subtropical NA, while some biogeochemical variables probably control the pCO2sea variation in the subpolar NA.

Sphingosine-1-phosphate signaling in vasculogenesis and angiogenesis

Blood vessels either form de novo through the process of vasculogenesis or through angiogenesis that involves the sprouting and proliferation of endothelial cells in pre-existing blood vessels. A complex interactive network of signaling cascades downstream from at least three of the nine known G-protein-coupled sphingosine-1-phosphate (S1P) receptors act as a prime effector of neovascularization that occurs in embryonic development and in association with various pathologies. This review focuses on the current knowledge of the roles of S1P signaling in vasculogenesis and angiogenesis, with particular emphasis on vascular cell adhesion and motility responses.

Role of gut microbiota in cardiovascular diseases

The human gut is colonized by a community of microbiota,primarily bacteria,that exist in a symbiotic relationship with the host.Intestinal microbiota-host interactions play a critical role in the regulation of human physiology.Deleterious changes to the composition of gut microbiota,referred to as gut dysbiosis,has been linked to the development and progression of numerous diseases,including cardiovascular disease(CVD).Imbalances in host-microbial interaction impair homeostatic mechanisms that regulate health and can activate multiple pathways leading to CVD risk factor progression.Most CVD risk factors,including aging,obesity,dietary patterns,and a sedentary lifestyle,have been shown to induce gut dysbiosis.Dysbiosis is associated with intestinal inflammation and reduced integrity of the gut barrier,which in turn increases circulating levels of bacterial structural components and microbial metabolites,including trimethylamine-N-oxide and short-chain fatty acids,that may facilitate the development of CVD.This article reviews the normal function and composition of the gut microbiome,mechanisms leading to the leaky gut syndrome,its mechanistic link to CVD and potential novel therapeutic approaches aimed towards restoring gut microbiome and CVD prevention.As CVD is the leading cause of deaths globally,investigating the gut microbiota as a locus of intervention presents a novel and clinically relevant avenue for future research.

LITTLEWOOD-PALEY THEOREM FOR SCHR DINGER OPERATORS

Let H be a Schroedinger operator on R^n. Under a polynomial decay condition for the kernel of its spectral operator, we show that the Besov spaces and Triebel-Lizorkin spaces associated with H are well defined. We further give a Littlewood-Paley characterization of Lp spaces in terms of dyadic functions of H. This generalizes and strengthens the previous result when the heat kernel of H satisfies certain upper Gaussian bound.

Nonlinear control techniques for an atomic force microscope system

Two nonlinear control techniques are proposed for an atomic force microscopesystem. Initially, a learning-based control algorithm is developed for the microcantilever-samplesystem that achieves asymptotic cantilever tip tracking for periodic trajectories. Specifically, thecontrol approach utilizes a learning-based feedforward term to compensate for periodic dynamics andhigh-gain terms to account for non-periodic dynamics. An adaptive control algorithm is thendeveloped to achieve asymptotic cantilever tip tracking for bounded tip trajectories despiteuncertainty throughout the system parameters. Simulation results are provided to illustrate theefficacy and performance of the control strategies.

Nonlinear scanning structured illumination microscopy based on nonsinusoidal modulation

Structured illumination microscopy(SIM)is an essential super-resolution microscopy technique that enhances resolution.Several images are required to reconstruct a super-resolution image.However,linear SIM resolution enhancement can only increase the spatial resolution of micros-copy by a factor of two at most because the frequency of the structured illumination pattern is limited by the cutoff frequency of the excitation point spread function.The frequency of the pattern generated by the nonlinear response in samples is not limited;therefore,nonlinear SIM(NL-SIM),in theory,has no inherent limit to the resolution.In the present study,we describe a two-photon nonlinear SIM(2P-SIM)technique using a multiple harmonics scanning pattern that employs a composite structured illumination pattern,which can produce a higher order harmonic pattern based on the fluorescence nonlinear response in a 2P process.The theoretical models of super-resolution imaging were established through our simulation,which describes the working mechanism of the multi-frequency structure of the nonsinusoidal function to improve the reso-lution.The simulation results predict that a 5-fold improvement in resolution in the 2P-SIM is possible.

An Integrated Genetic,Physical and Transcript Map of Homoeologous Chromosomes 12 and 26 in Upland Cotton(Gossypium hirsutum L.)

While Upland cotton(Gossypium hirsutum L.) represents 95% of the world production,its genetic improvement is hindered by the shortage of effective genomic tools and resources.The