Browse Articles

Magnetic geometry induced quantum geometry and nonlinear transports

3D visualization design of digital intelligent landscape environment based on wireless network security

Varying effectiveness of real-time biofeedback across various activities in preserving lumbar Lordotic curvature using an inertial measurement system

The impact of PCA derived gait kinematic variations on estimated medial knee contact forces in a knee osteoarthritis population

Dietary zinc intake associated with stroke in American adults

Information and communication technology, upgrading of industrial structure and spatial spillover effect

Experimentally testing the circuit models of a Josephson junction embedded in a transmission line

As a typical nonlinear device, Josephson junction (JJ) can be either served as a microwave device to scatter the traveling microwave or embedded in a transmission line (TL) resonator to modify the mode structure. However, two mutually exclusive circuit models have been proposed to describe the JJ embedded in a TL: one is the series embed model [see, e.g., Zueco et al., Phys. Rev. B 86, 024503 (2012)] and another is the parallel embedded one [see, e.g., Yamamoto et al., Appl. Phys. Lett. 93, 042510 (2008)]. Here, beginning with the comparison of the theoretical predictions of these two models, we fabricate the JJ-embedded TL device and measure its microwave scattering parameters at 50-mK low temperature. The experimental results support the parallel embedded model, thus rule out the series embedded one. The present work might lay the physical foundation for the designs of various microwave JJ devices, such as the microwave photonic crystals, superconducting qubits, also the Josephson parameter amplifiers, etc., by embedding the JJs into the superconducting TLs.

Quantitative X-ray phase-contrast digital histology of liver metastases in a mouse model

Abstract Investigating the tissue modifications occurring as a consequence of tumour development is an important goal in preclinical medical research, as it can provide a better understanding of the mechanisms behind its origin and spread. Tumor microenvironment has a supportive role in cancer development and can be exploited as a therapeutic target to prevent and contrast metastatic spread, which usually leads to a poor prognosis. In this work, a colorectal cancer model of liver metastasis is used to perform proof-of-concept quantitative investigations of the changes occurring in murine liver tissue due to the formation of metastases. X-ray phase contrast imaging performed with synchrotron radiation was used to obtain high resolution and contrast on soft tissues with minimum sample preparation and a large field of view on a 3D volume. A pixel size of 3 µm, and 0.7 µm have been used. to visualize and quantify liver microvasculature, referred to as sinusoids, and to identify significant morphological differences between control and metastatic tissues. A reorganization of the hepatic tissue, characterized by increased vascularization around the metastatic lesions coupled with a significant reduction in the sinusoidal network in the distal liver parenchyma was observed. X-ray findings are also supported by conventional histology, proving X-ray phase contrast imaging as an informative complementary technique.

Robust and tunable oxide nanoscrolls for solar-driven H2 generation and storage

Hydrogen gas is a promising alternative to fossil fuels due to its high energy output and environmentally safe byproducts. Various morphologies of photocatalytic materials have been explored for high-efficiency H2 production, for instance, quasi-1D nanoscroll structures that provide a larger surface-to-volume ratio. Recently, we predicted layer-by-layer formation of stable oxide nanoscrolls directly from dichalcogenide precursors, eliminating the need for costly formation of two-dimensional oxides for a roll-up synthesis of nanoscrolls. In this study, we evaluate the suitability of those oxide nanoscroll materials—MoO3, WO3, PdO2, HfO2, and GeO2—for solar-driven photocatalytic H2 production and storage. Using excited state theory coupled with Bethe–Salpeter equation simulations, we discern their electronic and optical properties as a function of interlayer scroll spacing and find them to be highly conducive for solar-driven photocatalysis. Additionally, using ab initio molecular dynamics simulations, we show that they are also suitable for H2 storage as the nanoscrolls exhibit an effective trapping of hydrogen, even in the presence of defects and vacancies in the oxides. This work thus demonstrates the discovery of robust and tunable oxide nanoscrolls as materials for advancing solar-driven hydrogen technologies.

Combining kinetics and in silico approaches to evaluate bromhexine as an anti-pancreatic lipase agent for obesity management

Abstract Industrialization, fast food intake and reduced physical activity, mainly in developed countries, exacerbate obesity and make it a major lifestyle disorder. A promising strategy for developing effective anti-obesity agents is to inhibit pancreatic lipase, thereby reducing lipid absorption. Currently, the only clinically approved pharmacological agent for pancreatic lipase inhibition is Orlistat. However, its undesirable gastrointestinal side effects have prompted the search for more effective and potent drugs. This study investigates the inhibitory mechanism of Bromhexine, a mucolytic drug, on pancreatic lipase using Lineweaver–Burk plot analysis and molecular docking, along with simulations, and compares its efficacy to that of the Food and Drug Administration (FDA) approved drug Orlistat. Kinetic analysis indicates that Bromhexine exhibits mixed inhibition of pancreatic lipase, with IC50 and Ki values of 360 µM and 450 µM, respectively, which are comparable to those of Orlistat. Molecular docking confirms that Bromhexine interacts with the His263 residue in the enzyme’s active site through hydrogen bonding, similar to Orlistat, thereby reducing the enzyme’s affinity for its natural substrate. Binding pose metadynamics (BPMD) simulations further supports the stability of Bromhexine’s interactions. Collectively, our findings suggest that Bromhexine displays potent pancreatic lipase (PL) inhibition activity and could serve as a potential candidate in weight management as demonstrated by both in silico and in vitro analyses. However, further investigations, including structure-activity relationship (SAR) analyses and in vivo studies, are necessary to confirm its clinical potential as a pancreatic lipase inhibitor.

Dzyaloshinskii-Moriya bias theory for thin magnetic slabs

Magnetic bias has been thoroughly explored during recent decades. The off-center shift of the hysteresis loop is usually achieved through exchange or dipolar interactions. However, the recently identified Dzyaloshinskii-Moriya Bias (DMB) offers an alternative to dipolar and exchange bias. A key advantage of DMB is its occurrence in a single uniform physical component, without the need for multiple layers and interfaces required by other mechanisms. It applies to thin in-plane magnetic slabs with bulk Dzyaloshinskii-Moriya interaction. An important advantage of these systems is that an external magnetic field can control the magnitude of the loop shift. Here, we present a general theoretical framework for the conditions to obtain DMB, which also clarifies the underlying principles of the effect. Our results suggest that this mechanism opens several possibilities in developing innovative applications.

Registered clinical trials targeting type 2 diabetes remission with pharmacological interventions

Strain-induced orientational dependent ferroelectric phase transition in anisotropic NbOCl2 flakes

Strain engineering demonstrates remarkable precision in inducing phase transitions, as well as high orientability, enabling tunable phase transitions with low energy consumption and rapid response. NbOCl2, an emerging ferroelectric (FE) layered two-dimensional (2D) material, exhibits pronounced in-plane FE properties and demonstrates a significant anisotropic second harmonic generation response. Here, we demonstrate that the FE phase transition in NbOCl2 can be modulated by applying strain relative to its intrinsic lattice orientation. It has been discovered that the strain-induced FE phase transition in NbOCl2 crystals depends on the direction of the polar axis. Specifically, when strain is applied along the polar axis and reaches a minimal threshold of just 0.65%, it induces a transition from the FE phase to the antiferroelectric phase. By releasing the strain, NbOCl2 reverts to the FE phase, enabling a tunable phase transition along the polar axis. Furthermore, it was discovered that the challenge in inducing phase transition behavior by applying uniaxial strain along the nonpolar axis is due to the difficulty in effectively coupling the strain field to the key atomic interaction system that determines the FE properties. This work not only provides valuable strategies and insights for inducing reversible phase transitions in other 2D materials but also establishes a robust foundation for the development of FE memory devices with enhanced directional controllability.

Differential benefits of 12-week morning vs. evening aerobic exercise on sleep and cardiometabolic health: a randomized controlled trial

Oxygen plasma and post-annealing assisted surface oxidation for high-<i>V</i>th E-mode <i>p</i>-GaN HEMTs

This paper proposes an oxygen plasma-assisted surface oxidation technique and demonstrates that thermal annealing in an oxygen atmosphere can effectively accelerate the formation of GaON, thereby improving the threshold voltage and gate breakdown voltage of p-GaN HEMT. The effects of annealing temperature in an oxygen environment after plasma treatment on Ga-O bond strength and p-GaN surface leakage characteristics are systematically investigated. The evolution of the valence band maximum during oxidation was systematically analyzed. Experimental results reveal that the oxidized GaN exhibits a valence band offset of 1.4 ± 0.8 eV compared to initial GaN, which effectively impedes carrier transport in p-GaN and suppresses leakage currents. By optimizing the oxidation process, a 5-nm-thick gate oxide layer was formed on the p-GaN surface within a short duration. Consequently, the p-GaN HEMT demonstrated significant performance enhancements: the threshold voltage increased from 2.1 to 4.4 V, the gate breakdown voltage improved from 9 to 24.1 V, and the operational gate voltage range expanded from 6 to 12 V. These findings validate the efficacy of the oxygen plasma and post-annealing assisted surface oxidation technique, highlighting its potential for advancing high-performance GaN power devices.

Co-exposure to inhaled tungsten particles and low-dose gamma rays: neurotoxicological outcome in rats

Modular Synthesis of Dendritic Oligo‐Glycerol Cationic Surfactants for Enhanced Antibacterial Efficacy

Abstract Bacterial infections and antibiotic resistance present an ever‐increasing threat to human health worldwide, and medicine urgently needs new alternatives for the successful treatment of bacterial infections. Cationic surfactants have proven to be effective antibacterial agents due to their ability to disrupt bacterial membranes, inhibit biofilm formation, and combat a broad spectrum of pathogens. We employed a orthogonal click chemistry strategy for the efficient modular synthesis of six novel cationic surfactants. Our results emphasize the strong correlation between the surfactant design and its antibacterial potential. Among these six cationic surfactants we identified a prime candidate, which possessed an impressive antibacterial effect against gram‐positive and gram‐negative bacteria, including drug‐resistant strains. We found that our surfactant can prevent biofilm formation and eradicate already existing biofilms. Cryo‐TEM imaging was used to reveal the membrane‐disrupting properties of the surfactant. In‐vivo wound healing experiments underline the surfactants’ ability to inhibit wound infections. Cationic surfactants often face the challenge of balancing strong antibacterial activity with minimal cytotoxicity. Our strategic design and orthogonal click chemistry approach have enabled precise fine‐tuning of molecular structures to achieve an optimal balance between antibacterial efficacy and biocompatibility, effectively overcoming this critical limitation.

Efficiency droop contributors in InGaN green light emitting diodes

Here, efficiency droop contributors (i.e., inherent Auger–Meitner recombination, polarization-induced effects, thermal effects, and light extraction) in InGaN green light emitting diodes (LEDs) are decoupled and quantified. First, a modified ABC model is developed, and external quantum efficiency measurements are taken under constant and pulsed currents (EQEConstant and EQEPulsed, respectively). The LED internal quantum efficiency with and without thermal effects (IQEConstantABC and IQEPulsedABC, respectively) is extracted using the modified model. Then, using Raman spectroscopy, the LED junction temperature is extracted. Finally, using the optical-electrical model (OEM), the polarization- and temperature-independent LED internal quantum efficiency (IQEOEM) is calculated from the modified ABC model and the extracted junction temperature. By comparing external (EQEConstant) and the three internal quantum efficiencies (IQEConstantABC, IQEPulsedABC, and IQEOEM), the impacts of inherent Auger–Meitner recombination, polarization-induced effects, thermal effects, and light extraction on the efficiency droop are decoupled and quantified. It is found that inherent Auger–Meitner recombination-induced droop is approximately 49% of the total efficiency droop in commercial green LEDs, while polarization-induced effects contribute about 35%, and thermal droop accounts for nearly 16%. These findings suggest, to quash the green gap, it is critical to search for materials and device designs with low inherent Auger–Meitner coefficients and polarization fields, respectively.

Impact of Tung oil on a sustainable bio-based polymer, and development by zinc oxide nanoparticles

Abstract The use of natural and bio-based materials instead of petrochemicals is strongly recommended for reducing greenhouse gas emissions. Here we aim to promote the environmentally friendly bio-based polyester (P), prepared from biomass, with natural Tung oil (TO) plasticizer and zinc oxide nanoparticles (ZnO NPs) filler by 10–50%, and 3% to get a sustainable nanocomposite. The grafting altered the profile of neat P. Owing to insufficient contents, low concentrations have a slight impact, and high concentrations have more enhancements. The physical properties accompanied by curing of P/TO copolymer showed a decrease in viscosity, gelation time, and gelation-curing period for TO-based specimens, besides the lower heat emission during curing reaction, compared with that of P, by 3.4% and 4%, respectively, for P/TO-40 and P/TO-50 copolymers. The stability against exudation was promoted by 48.6%, where all concentrations of composites are more stable than P. P/TO-40 and P/TO-50 improved creep resistance by 62% and 88.1%, respectively, due to the stable surfaces. Furthermore, P/TO-50 concentration reduced hardness by 25%, but it was improved by ZnO NPs by 46.7%. Both TO plasticizer and nanofiller make the polymer capable of absorbing the flexural loading as a toughened composite. The proposed composites provide positive effects on the thermal behavior. Particularly, the P/TO-50 formula decreased the value of tan Delta by 35.5%; all composites increased T g as well. The obtained data-results and SEM photos confirm the grafting and good distribution of TO plasticizer and ZnO NPs into P matrix through an improved and stable homogeneous bio-based polymer nanocomposite.

Imaging Heterogeneous Patterns of Aminopeptidase N Activity in Hierarchical Tissue Structures Through High‐Resolution Whole‐Organ 3D Mapping

Abstract Enzymes play a crucial role in regulating physiological functions, and abnormal enzyme activity is associated with various pathological conditions. Precise imaging of enzyme activity in tissues, providing detailed spatial and quantitative information, advances our understanding of physiological and pathological processes. Despite their importance, there is still a lack of methods for high‐resolution 3D imaging of enzyme activity across entire tissues. In this research, we report a methodology for high‐resolution, whole‐organ 3D mapping of enzyme activity, which combines tissue clearing with an activity‐based covalent chemical probe. Focusing on aminopeptidase N (APN) as a representative target of peptidase, we developed ANA‐ o ‐BODIPY, an activity‐based covalent fluorescent probe compatible with tissue clearing for imaging APN activity. Upon activation by APN, ANA‐ o ‐BODIPY produces a reactive intermediate, aza‐quinone methide, which covalently binds to proximal proteins. This covalent probe is successfully utilized to record the location of APN activity during the tissue‐clearing process. By combining the probe with tissue clearing, we have achieved high‐resolution 3D mapping of APN activity across whole organs for the first time. Moreover, this advancement allowed us to visualize the heterogeneity of APN activity in individual tubular structures and to uncover the inhibitory effects of different APN inhibitors.