Browse Articles

Amphiphilic Zeolitic Imidazolate Framework for Improved CO ₂ Separation in PIM‐1 Mixed Matrix Membranes

Abstract This study aims to enhance the compatibility between filler and polymer in mixed matrix membranes (MMMs), addressing an important challenge in membrane development. ZIF‐94, known for its affinity to CO 2 , was partially modified with 2‐undecylimidazolate (umIm) through the solvent‐assisted ligand exchange (SALE) method to improve its compatibility with the prototypical polymer of intrinsic microporosity PIM‐1. The modified ZIF‐94 (ZIF‐94‐umIm) can be considered as an amphiphilic MOF with both hydrophilic and hydrophobic moieties, while maintaining a considerably high CO 2 adsorption capacity (2.34 mmol g −1 at 90 kPa and 0 °C). Gas separation experiments were performed using mixed gas compositions of 15/85 CO 2 /N 2 at 3 bar and 35 °C. The resulting MMM with a 5 wt.% loading exhibited an enhanced CO 2 separation performance, with ca. 70% and 10% increases in CO 2 permeability (8900 Barrer) and CO 2 /N 2 selectivity (20.2), respectively, compared to pristine PIM‐1 membranes. In addition, thin film nanocomposite membranes were prepared showing a 23.5 CO 2 /N 2 selectivity at 2350 GPU of CO 2 . This modification strategy shows a great potential for improving the CO 2 capture technologies, highlighting the potential of tailoring MOF fillers for advanced membrane materials in gas separation applications.

Tunable spin-valley states in collinear-antiferromagnetic Janus Re2X3Y3 (X, Y = I, Br, Cl; X ≠ Y) monolayers

The unconventional spin-valley states in the collinear-antiferromagnetic (AFM) Janus Re2X3Y3 (X, Y = I, Br, Cl; X ≠ Y) monolayers are predicted using effective k · p and tight binding models, which are few reports on two-dimensional AFM systems. The Janus Re2X3Y3 systems with built-in electric fields along the axis of rotation do not lack PT symmetry. Considering spin–orbit coupling, non-highly spin degenerate valleys will spontaneously polarize. The valley polarization of the collinear-AFM hexagonal lattice is effectively adjusted through strain engineering, achieving strong correlations between strain and valley physics in 2D antiferromagnets. However, an interesting single valley state is also observed in the Janus Re2X3Y3 monolayers, which is due to the fact that high tensile strain alters the next-nearest neighbor hopping of Re atoms, resulting in an increase in AFM interaction. In addition, the unique symmetry of the dimer sublattice leads to unusual band structures, further triggering interesting Berry curvature distributions (zero at the K/K′ point), breaking the previous understanding that only exists in bilayer systems. These physical properties of collinear-AFM Janus Re2X3Y3 systems can be expected to replace ferromagnets as the material foundation of spintronics.

Profiling protein hydrolysis and amino acid metabolism in camel and bovine milk fermented by Lactobacillus helveticus, L. bulgaricus, and Streptococcus thermophilus

Omnidirectional magneto-acoustic coupling in acoustically driven magnetoelectric antenna with focused interdigital transducers

Acoustically driven magnetoelectric (ME) antennas present a promising approach for achieving orders-of-magnitude miniaturization. However, conventional resonator-based ME antennas suffer from substantial acoustic energy leakage, which limits the effective utilization of the magneto-acoustic coupling effect in the magnetostrictive (MS) film. In this work, we propose and experimentally demonstrate a surface acoustic wave ME antenna based on a piezoelectric-on-insulator substrate. By employing focused interdigital transducers, we spatially confine acoustic waves, significantly enhancing the acoustic energy density within the MS film and thereby improving the efficiency of magneto-acoustic coupling. Experimental results reveal that with MS film loading, the antenna's radiated power increases by a factor of 32.55 compared to an unloaded reference structure, achieving a gain of −26.78 dBi, an electromechanical coupling coefficient (k2) of 8.79%, a quality factor (Q) of 217, and a figure of merit (FoM, k2×Qmax) of 19.07. Furthermore, applying an external bias magnetic field of 300 Oe modulates the magnetocrystalline anisotropy, leading to a 1.84% enhancement in the antenna's resonance characteristics and a 7.15% improvement in radiation performance. By varying the magnetic field orientations, we further verify the proposed structure's omnidirectional magneto-acoustic coupling behavior. These findings provide insights into the design of next-generation miniaturized antennas with enhanced performance and tunability.

Transgenic zebrafish embryos to evaluate the in vivo effects of different liposome-paclitaxel nanocarrier system

Inversion-sensing SiO2-based MOS capacitive synapse for neuromorphic computing

In this work, an inversion-sensing SiO2-based capacitive synapse device was introduced by using the lateral coupling effect in a concentric metal–oxide–semiconductor structure. The device achieved a CHCS/CLCS ratio of 24 with a low programming voltage of VPGM = −2.5 V. Technology Computer Aided Design (TCAD) simulations confirmed the device's high sensitivity to changes in external charges. For oxide with an effective positive charge density (Neff) exceeding 2.8×1011 cm−2, a small variation of 5×109 cm−2 could influence a lot in the capacitance value of the device in the inversion region. This sensitivity enabled multi-state capacitance modulation by adjusting the number of pulses and operating voltages. Additionally, the scalability of the device was validated through simulations. The on/off ratio could be further improved by substituting the gate dielectric material. Overall, the lateral coupling effect not only enhances the performance of charge-trapping-based devices but also provides a viable strategy for expanding memory windows across various types of capacitive memory technologies.

Nanoencapsulation enhances stability, release behavior, and antimicrobial properties of Sage and Thyme essential oils

THz cyclotron resonance of a 2D hole gas in a GaN/AlN heterostructure

The recent discovery of highly conducting two-dimensional hole gases (2DHGs) in GaN/AlN heterojunctions has opened the door to efficient complementary GaN electronics, a long-standing challenge in wide-bandgap semiconductor device physics. Electrical transport studies and simulations indicate that both heavy- and light-hole valence bands are occupied in these 2DHGs, but direct experimental characterization of the fundamental parameters of the mobile holes remains at an early stage. Here, we use time-domain terahertz spectroscopy and pulsed magnetic fields up to 31 T to directly measure cyclotron resonance of the mobile 2D holes in these GaN-based 2DHGs at low temperature (8 K), revealing key material properties including effective masses, densities, scattering times, and mobilities.

Translation of computed tomography images to T2-Weighted magnetic resonance images of lumbar spine using generative adversarial networks on sagittal images

Electronic structure regulation via heterojunction engineering for enhanced oxygen reduction reaction

Transition metal catalysts have promising applications as potential alternatives to platinum-based catalysts in oxygen reduction reactions (ORR), and fine-tuning their local electronic structure is an essential strategy to boost the intrinsic activity. Herein, a Zr–Cu heterojunction catalyst was synthesized by combining ZrO2/C and Cu2(OH)2CO3/C using a simple sol-gel synthesis method. The Zr–Cu heterojunction synergistically achieved high ORR performance with a noticeable half-wave potential of 0.827 V, comparable to commercial Pt/C, along with superior stability and methanol tolerance in alkaline solution. X-ray absorption near-edge spectroscopy (XANES) demonstrated that the interfacial electronic interaction between Zr and Cu species in Zr–Cu heterojunction was enhanced, leading to the enhanced ORR activity. Combined with density functional theory calculations, the Cu atoms located at the interface of Zr–Cu heterojunction were identified as the ORR active sites, while the Zr atoms served as an electronic regulator to induce the electron redistribution by facilitating electron transfer from Zr species and Cu active sites. Therefore, the engineering of Zr–Cu heterojunction catalyst greatly optimized the adsorption strength of O2 as well as reduced the energy barrier of *O2 → *OOH intermediate, ultimately resulting in the promoted ORR performance. The findings of this study suggest a valuable strategy for manipulating heterojunction to optimize the electronic structure of catalytic active sites and improve electrocatalytic reactions.

Combined dynamic nuclear polarization and electron paramagnetic resonance at 0.34 T to investigate electrochemical lithium deposition on copper

Abstract Despite extensive research conducted on plating and dendrite formation in lithium batteries, the molecular formation processes are not yet fully understood. Electron paramagnetic resonance (EPR) sensitively detects metallic Li species but misses non-paramagnetic ones. Nuclear magnetic resonance (NMR) is chemically selective, yet exhibits low sensitivity under low-field conditions. Dynamic nuclear polarization (DNP) overcomes this by transferring electron spin polarization to nuclei. Here, correlative EPR and DNP-enhanced $$^{7}\textrm{Li}$$ NMR of lithium on copper is demonstrated using a custom setup operating at 0.34 T with a sweepable electromagnet. DNP experiments were conducted in pulsed mode to minimize sample heating. The resulting enhanced $$^{7}\textrm{Li}$$ NMR signal allows the observation of electrochemically deposited lithium on copper, harvested from a Cu vs. Li cell, with an enhancement  $$\epsilon >400$$ . By changing the magnetic field strength by a few Gauss, the saturation of the conduction EPR transition was varied, leading to an altered Knight shift of metallic $$^{7}\textrm{Li}$$ . The corresponding change of the DNP-polarized $$^{7}\textrm{Li}$$ chemical shifts in the range from 240 ppm to 80 ppm allowed an indirect, saturation-based distinction of EPR species. Moreover, an enhancement  $$\epsilon$$ by a factor of about 2 of the $$^1$$ H signal from the surrounding electrolyte of electrochemically deposited lithium was observed, indicating the potential to investigate the solid–electrolyte interface (SEI). The setup employed a battery cell housing developed for EPR, demonstrating its suitability for in operando experiments in the future.

Impact of threading dislocations on the V-defect assisted lateral carrier injection and recombination in InGaN quantum well LEDs

The nonuniform hole distribution between InGaN quantum wells (QWs) of light emitting diodes (LEDs) has a negative impact on LED efficiency. The uniformity can be increased by using lateral hole injection through sidewalls of V-defects, which form at threading dislocations. However, the inherent coupling between the V-defects and dislocations might affect efficiency of the hole injection and nonradiative recombination. In this work, we have tested the possible impact of the dislocations on the injection and recombination by means of scanning near-field electroluminescence and photoluminescence spectroscopy on single green-emitting InGaN QW LEDs containing large (∼0.5 μm) V-defects. The measurements have not provided any evidence of a lower hole injection efficiency or enhanced nonradiative recombination at the dislocations located at the V-defect facets or their apexes. This shows that large V-defects are excellent volumetric injectors for long wavelength InGaN LEDs. Furthermore, it was established that V-defects are preferential hole injectors even in single quantum well devices. Compared to vertical injection, the V-defect injection allows lowering the operating voltage, which should contribute to an enhanced wall plug efficiency.

Immune, metabolic, anatomical, and functional features of people after successful tuberculosis treatment: an exploratory analysis

NiOx gate oxide for enhanced thermal stability of threshold voltage in GaN MIS-HEMTs up to 400 °C

This study demonstrates the high-temperature operation of AlGaN/GaN metal–insulator–semiconductor high electron mobility transistors (MIS-HEMTs) based on nickel oxide (NiOx) as an intermediate gate oxide, achieving stable performance up to 400 °C. Compared to the control sample with only an SiNx gate dielectric, the proposed device exhibited significant improvements: (1) enhanced thermally induced VTH stability, (2) a flat transconductance (gm) curve indicating improved linearity, and (3) lower and stable drain-to-source saturation voltage (VDS,sat). Notably, the ΔVTH shift for D-mode MIS-HEMT with NiOx was effectively reduced to ∼+0.4 V, compared to ∼−1.4 V in the control sample, over a temperature range from 25 to 400 °C. This improvement is attributed to hole carrier generation in the NiOx layer, which increases the depletion region and stabilizes the stored charge underneath the gate at high temperatures. This work demonstrates that the NiOx gate oxide layer significantly enhances VTH stability and linearity in GaN MIS-HEMT, ensuring reliable and stable device operation at high temperatures.

Greenness assessment and phototoxicity of rose bengal and methylene blue on immature aquatic stages of malaria vector Anopheles pharoensis

Abstract This study systematically evaluated the efficiency of rose bengal and methylene blue as photosensitizers against the immature aquatic stages of Anopheles pharoensis. Genetic identification using the COI partial sequence confirmed the species, and the obtained sequence was submitted to GenBank (Accession No. PQ346929). Both photosensitizers exhibited 100% mortality in larvae I within 24 h at their highest concentrations, demonstrating strong biocidal activity. LC50 values for rose bengal increased from 1.50 ppm (24 h) and 1.34 ppm (48 h) in larvae I to 3.83 ppm (24 h) and 3.12 ppm (48 h) in pupae. Similarly, methylene blue showed LC50 values rising from 1.14 ppm (24 h) and 0.90 ppm (48 h) in larvae I to 2.91 ppm (24 h) and 2.51 ppm (48 h) in pupae, indicating stage-dependent susceptibility. Enzymatic responses revealed a progressive increase in acetylcholinesterase (AChE) and glutathione S-transferase (GST) activity in the developmental stage, suggesting a physiological adaptation to the photosensitizers. Molecular docking against the AChE protein (PDB ID: 6xyu) confirmed insecticidal bioactivity, with methylene blue exhibiting superior binding affinity, aligning with the in-vitro larvicidal results. Furthermore, a Complex GAPI assessment confirmed the environmental sustainability of both photosensitizers, supporting their potential as eco-friendly alternatives for mosquito control. The use of Complex GAPI in assessing the environmental sustainability of photosensitizers in mosquito control represents a novel approach in the field of integrated pest management. This advancement not only aligns with the principles of green chemistry but also addresses the growing need for sustainable alternatives to traditional chemical insecticides. These findings highlight the feasibility of utilizing light-activated photosensitizers for sustainable vector management.

Leveraging Noncovalent Interactions for the Binding of CO by a Weakly Lewis Acidic Borane

Abstract Known boron carbonyl complexes either exploit very high Lewis acidity or a low oxidation state boron centre in order to capture CO. By contrast, we report a carbonyl complex featuring a simple tri‐coordinate borane, characterized by a Lewis acidity which is only marginally higher than B(NMe 2 ) 3 . {(Ph 2 P)xanth} 3 B features a solid‐state structure in which two of the three B‐bound xanth(PPh 2 ) units are projected above the BC 3 plane, generating an up , up , down conformation. Quantum chemical methods, however, reveal that the alternative up , up , up alignment, characterized by a cage‐like geometry and enhanced intramolecular noncovalent interactions, is favored significantly in silico (by ca. 33.0 kcal mol −1 ). Although this conformation is optimal for binding polar C 3 ‐symmetric H‐bond donors such as NH 3 (and related guests such as H 2 O and MeNH 2 ) the binding of essentially nonpolar substrates such as CO would be expected to be weak at best. However, exposure of {(Ph 2 P)xanth} 3 B to CO under mild conditions (1 bar, 25 °C) reversibly yields {(Ph 2 P)xanth} 3 B·CO, a tractable cage‐like borane carbonyl adduct featuring a central BCO moiety shrouded by xanth(PPh 2 ) moieties. Dispersion forces are critical to substrate binding: the two binding modes in which the B‐bound CO guest is located inside/outside the host cage differ in energy by 59.5 kcal mol −1 .

Epitaxial growth of Yb/Er co-doped HfO2 films with coexisting ferroelectric and luminescent properties

We report on the fabrication of high-quality Yb3+ and Er3+ co-doped HfO2 epitaxial films using pulsed laser deposition. The host material HfO2 has relatively low phonon energy, which is desirable to inhibit the nonradiative relaxation. The dopant Yb3+ is used to stabilize the ferroelectric o-phase and also acts as the sensitizer to enhance the optical absorption cross section, while Er3+ is the luminescence activator. The films exhibit robust ferroelectricity with a remanent polarization of 12 μC/cm2 and comparable endurance performance to HfO2-based epitaxial films reported before. The up- and downconversion luminescence properties were ascertained by photoluminescence spectroscopy. The Yb3+/Er3+ co-doped HfO2 films with coexisting ferroelectric and luminescent functionalities may suggest a promising approach toward electric field tunable phosphors.

Evaluation of spatial visual perception of streets based on deep learning and spatial syntax

High-field electron transport properties of β-Ga2O3: An integrated Monte Carlo and first-principles approach

In this work, we investigate the high-field electron transport properties of monoclinic gallium oxide (β-Ga2O3) by integrating full-band Monte Carlo simulations with first-principles calculations. Our approach dynamically generates electron–phonon transition rates eliminating the need for parameters fitting. The simulation results reveal a pronounced velocity overshoot at electric field strengths exceeding 100 kV/cm, with a peak drift velocity of 2.5 × 107 cm/s observed at 400 kV/cm along the a-axis at room temperature. The analysis underscores the significant contributions of both Bu and Ag optical phonon scattering in governing the transport phenomena under high electric fields. Moreover, the study identifies intrinsic anisotropy in electron transport characteristics, with distinct behaviors evident between high-field and low-field regimes. These findings provide critical insight into the optimization of β-Ga2O3-based electronic devices for high-frequency and high-power applications.

Population pharmacokinetics of colistin sulfate in critically ill patients based on NONMEM

Abstract As the last defense against multidrug-resistant gram-negative bacteria, colistin sulfate’s clinical use, which is often empirical, risks resistance and adverse reactions. This study aimed to develop a population pharmacokinetic (PPK) model of colistin sulfate for critically ill patients and determine the optimal dosing regimen. This retrospective study included 204 critically ill patients. We used a validated LC-MS/MS method to measure its plasma concentrations and RIFLE criteria for nephrotoxicity evaluation. NONMEM developed PPK models. Monte Carlo simulations set dosing regimens based on the probability of target attainment (PTA). A two-compartment model adequately described the data, creatinine clearance and weight were covariates for elimination rate and central volume, respectively. Only 11.8% had nephrotoxicity. With Monte Carlo simulations, all regimens except the maintenance dose of 0.5 MU administered every 12 h achieved > 90% PTA at the minimum inhibitory concentration (MIC) ≤ 0.5 mg/L. However, at MIC > 0.5 mg/L, the routine regimen resulted in insufficient exposure. Based on our PPK model, the dose of intravenous colistin sulfate should be adjusted according to creatinine clearance (CrCL) and weight. For critically ill patients with infections, under the conventional treatment regimens, when the MIC is ≥ 1 mg/L, it is difficult for patients to achieve the ideal therapeutic effect in terms of exposure dose. When CrCL is below 10 ml/min, the regimen of 1 MU every 8 h used could cause the potential for increasing nephrotoxicity risk, which is significantly concerned.