Effects of red blood cell aggregation on the blood flow in a symmetrical stenosed microvessel.

In order to figure out whether red blood cell (RBC) aggregation is beneficial or deleterious for the blood flow through a stenosis, fluid mechanics of a microvascular stenosis was examined through simulating the dynamics of deformable red blood cells suspended in plasma using dissipative particle dynamics. The spatial variation in time-averaged cell-free layer (CFL) thickness and velocity profiles indicated that the blood flow exhibits asymmetry along the flow direction. The RBC accumulation occurs upstream the stenosis, leading to a thinner CFL and reduced flow velocity.

Altered dynamics of visual contextual interactions in Parkinson's disease.

Over the last decades, psychophysical and electrophysiological studies in patients and animal models of Parkinson's disease (PD), have consistently revealed a number of visual abnormalities. In particular, specific alterations of contrast sensitivity curves, electroretinogram (ERG), and visual-evoked potentials (VEP), have been attributed to dopaminergic retinal depletion. However, fundamental mechanisms of cortical visual processing, such as normalization or "gain control" computations, have not yet been examined in PD patients.

Impact of Surface Amphiphilicity on the Interfacial Behavior of Janus Particle Layers under Compression.

Langmuir monolayers of silica/gold Janus particles with two different degrees of amphiphilicity have been examined to study the significance of particle surface amphiphilicity on the structure and mechanical properties of the interfacial layers. The response of the layers to the applied compression provides insight into the nature and strength of the interparticle interactions. Different collapse modes observed for the interfacial layers are linked to the amphiphilicity of Janus particles and their configuration at the interface.

Anti-angiogenesis triggers exosomes release from endothelial cells to promote tumor vasculogenesis.

Although anti-angiogenic therapies (AATs) have some effects against multiple malignancies, they are limited by subsequent tumor vasculogenesis and progression. To investigate the mechanisms by which tumor vasculogenesis and progression following AATs, we transfected microRNA (miR)-9 into human umbilical vein endothelial cells (HUVECs) to mimic the tumor-associated endothelial cells in hepatocellular carcinoma and simulated the AATs in vitro and in vivo. We found that administration of the angiogenesis inhibitor vandetanib completely abolished miR-9-induced angiogenesis and promoted autophagy in HUVECs, but induced the release of vascular endothelial growth factor (VEGF)-enriched exosomes.

Antiepileptic Effects of a Novel Non-invasive Neuromodulation Treatment in a Subject With Early-Onset Epileptic Encephalopathy: Case Report With 20 Sessions of HD-tDCS Intervention.

The current clinical investigation examined high-definition transcranial direct current stimulation (HD-tDCS) as a focal, non-invasive, anti-epileptic treatment in a child with early-onset epileptic encephalopathy. We investigated the clinical impact of repetitive (20 daily sessions) cathode-centered 4 × 1 HD-tDCS (1 mA, 20 min, 4 mm ring radius) over the dominant seizure-generating cortical zone in a 40-month-old child suffering from a severe neonatal epileptic syndrome known as Ohtahara syndrome (OS). Seizures and epileptiform activity were monitored and quantified using video-EEG over multiple days of baseline, intervention, and post-intervention periods.

Dark-Exciton-Mediated Fano Resonance from a Single Gold Nanostructure on Monolayer WS at Room Temperature.

Strong spatial confinement and highly reduced dielectric screening provide monolayer transition metal dichalcogenides with strong many-body effects, thereby possessing optically forbidden excitonic states (i.e., dark excitons) at room temperature.

Organization of Embryonic Morphogenesis via Mechanical Information.

Embryonic organizers establish gradients of diffusible signaling molecules to pattern the surrounding cells. Here, we elucidate an additional mechanism of embryonic organizers that is a secondary consequence of morphogen signaling. Using pharmacological and localized transgenic perturbations, 4D imaging of the zebrafish embryo, systematic analysis of cell motion, and computational modeling, we find that the vertebrate tail organizer orchestrates morphogenesis over distances beyond the range of morphogen signaling.

Majorana vortex photons a form of entangled photons propagation through brain tissue.

This paper extends the concept of entangled vector vortex beams as a form of Majorana-like photons. Majorana photon quasi particles are introduced and attributed to a class of entangled vector beams and show higher transmission. These photons and the antiphotons are identical.

Nanophotonic engineering of far-field thermal emitters.

Thermal emission is a ubiquitous and fundamental process by which all objects at non-zero temperatures radiate electromagnetic energy. This process is often assumed to be incoherent in both space and time, resulting in broadband, omnidirectional light emission toward the far field, with a spectral density related to the emitter temperature by Planck's law. Over the past two decades, there has been considerable progress in engineering the spectrum, directionality, polarization and temporal response of thermally emitted light using nanostructured materials.

Measuring, Modeling, and Predicting the Magnetic Assembly Rate of 2D-Staggered Janus Particle Chains.

The assembly of magnetic Janus particles in a quasi-two-dimensional environment with a dipole moment shifted from the center and oriented perpendicular to the Janus cap height is studied with optical microscopy and found to adhere to a general model accounting for the particle dipole strength, the particle Brownian dynamics, the initial concentration, and, most importantly, the magnetic dipole shift. The particle aggregates are treated as diffusing spherocylinders with length and width dependent on the magnetic dipole shift. Aggregation occurs irreversibly once particle aggregates enter within a distance at which Brownian and dipole forces are equal, defined as the capture distance.

An Ecological Framework for Modeling the Geography of Disease Transmission.

Ecological niche modeling (ENM) is widely employed in ecology to predict species' potential geographic distributions in relation to their environmental constraints and is rapidly becoming the gold-standard method for disease risk mapping. However, given the biological complexity of disease systems, the traditional ENM framework requires reevaluation. We provide an overview of the application of ENM to disease systems and propose a theoretical framework based on the biological properties of both hosts and parasites to produce reliable outputs resembling disease system distributions.

Realistic volumetric-approach to simulate transcranial electric stimulation-ROAST-a fully automated open-source pipeline.

Objective: Research in the area of transcranial electrical stimulation (TES) often relies on computational models of current flow in the brain. Models are built based on magnetic resonance images (MRI) of the human head to capture detailed individual anatomy. To simulate current flow on an individual, the subject's MRI is segmented, virtual electrodes are placed on this anatomical model, the volume is tessellated into a mesh, and a finite element model (FEM) is solved numerically to estimate the current flow.

Endothelial surface glycocalyx (ESG) components and ultra-structure revealed by stochastic optical reconstruction microscopy (STORM).

Background: In order to play different roles in vascular functions as a mechanosensor to blood flows and as a barrier to transvascular exchange, the endothelial surface glycocalyx (ESG) should have an organized structure. Due to the limitations of optical and electron microscopy, the ultra-structure of ESG has not been revealed until the recent development of super-resolution optical microscopy, STORM.

Objectives: To investigate the ESG components and their organization on bEnd3 (mouse brain microvascular endothelial cells) monolayer.

Comparative study of macroporous silicon-based photovoltaic characteristics using indium tin oxide-silicon and pn-silicon junction based devices.

We report highly ordered macroporous silicon (Si)-based photovoltaic characteristics using indium tin oxide (ITO)/n-Si and pn-Si junction-based devices. The detailed fabrication processes including new controlled ITO etching are presented. Theoretical device simulations are performed to understand the presented device structures and propose an optimum device design based on processing limitations.

Supercluster-coupled crystal growth in metallic glass forming liquids.

While common growth models assume a structure-less liquid composed of atomic flow units, structural ordering has been shown in liquid metals. Here, we conduct in situ transmission electron microscopy crystallization experiments on metallic glass nanorods, and show that structural ordering strongly affects crystal growth and is controlled by nanorod thermal history. Direct visualization reveals structural ordering as densely populated small clusters in a nanorod heated from the glass state, and similar behavior is found in molecular dynamics simulations of model metallic glasses.

A combined computational strategy of sequence and structural analysis predicts the existence of a functional eicosanoid pathway in Drosophila melanogaster.

This study reports on a putative eicosanoid biosynthesis pathway in Drosophila melanogaster and challenges the currently held view that mechanistic routes to synthesize eicosanoid or eicosanoid-like biolipids do not exist in insects, since to date, putative fly homologs of most mammalian enzymes have not been identified. Here we use systematic and comprehensive bioinformatics approaches to identify most of the mammalian eicosanoid synthesis enzymes. Sensitive sequence analysis techniques identified candidate Drosophila enzymes that share low global sequence identities with their human counterparts.

Iron concentration linked to structural connectivity in the subthalamic nucleus: implications for deep brain stimulation.

Objective: The objective of this study was to investigate the relationship between iron and white matter connectivity in the subthalamic nucleus (STN) in patients undergoing deep brain stimulation (DBS) of the STN for treatment of Parkinson's disease.

Methods: Nine Parkinson's disease patients underwent preoperative 3T MRI imaging which included acquisition of T1-weighted anatomical images along with diffusion tensor imaging (DTI) and quantitative susceptibility mapping (QSM). MR tractography was performed for the seed voxels located within the STN, and the correlations between normalized QSM values and the STN's connectivity to a set of a priori chosen regions of interest were assessed.

From CREATE Workshop to Course Implementation: Examining Downstream Impacts on Teaching Practices and Student Learning at 4-Year Institutions.

The faculty workshop model has long been used for disseminating innovative methods in STEM education. Despite significant investments by researchers and funding agencies, there is a dearth of evidence regarding downstream impacts of faculty development. CREATE is an evidence-based strategy for teaching science using primary literature.

Trustworthiness appraisal deficits in borderline personality disorder are associated with prefrontal cortex, not amygdala, impairment.

Background: Borderline Personality Disorder (BPD) is associated with sensitivity to signals of interpersonal threats and misplaced trust in others. The amygdala, an integral part of the threat evaluation and response network, responds to both fear- and trust-related stimuli in non-clinical samples, and is more sensitive to emotional stimuli in BPD compared to controls. However, it is unknown whether the amygdalar response can account for deficits of trust and elevated sensitivity to interpersonal threat in BPD.

Jamming of Deformable Polygons.

We introduce the deformable particle (DP) model for cells, foams, emulsions, and other soft particulate materials, which adds to the benefits and eliminates deficiencies of existing models. The DP model combines the ability to model individual soft particles with the shape-energy function of the vertex model, and adds arbitrary particle deformations. We focus on 2D deformable polygons with a shape-energy function that is minimized for area a_{0} and perimeter p_{0} and repulsive interparticle forces.

Exceptional points in optics and photonics.

Exceptional points are branch point singularities in the parameter space of a system at which two or more eigenvalues, and their corresponding eigenvectors, coalesce and become degenerate. Such peculiar degeneracies are distinct features of non-Hermitian systems, which do not obey conservation laws because they exchange energy with the surrounding environment. Non-Hermiticity has been of great interest in recent years, particularly in connection with the quantum mechanical notion of parity-time symmetry, after the realization that Hamiltonians satisfying this special symmetry can exhibit entirely real spectra.

Observation of higher-order topological acoustic states protected by generalized chiral symmetry.

Topological systems are inherently robust to disorder and continuous perturbations, resulting in dissipation-free edge transport of electrons in quantum solids, or reflectionless guiding of photons and phonons in classical wave systems characterized by topological invariants. Recently, a new class of topological materials characterized by bulk polarization has been introduced, and was shown to host higher-order topological corner states. Here, we demonstrate theoretically and experimentally that 3D-printed two-dimensional acoustic meta-structures can possess nontrivial bulk topological polarization and host one-dimensional edge and Wannier-type second-order zero-dimensional corner states with unique acoustic properties.

Hyperbolic Phonon Polaritons in Suspended Hexagonal Boron Nitride.

Highly confined and low-loss hyperbolic phonon polaritons in hexagonal boron nitride possess properties analogous to surface plasmon polaritons, but with enhanced confinement and lower loss. Their properties have been so far mostly studied on dielectric substrates, which provide an asymmetric environment for polariton propagation, and add to damping. In this work, we investigate hyperbolic phonon polaritons over suspended hexagonal boron nitride, showing remarkable properties, including elongated polariton wavelength and reduced damping, up to 18% lower compared to dielectric-backed samples.