Effective Barrier Research Articles

Anti-inflammatory effects of moxifloxacin and levofloxacin on cadmium-activated human astrocytes: Inhibition of proinflammatory cytokine release, TLR4/STAT3, and ERK/NF-κB signaling pathway.

Cadmium is a non-essential element and neurotoxin that causes neuroinflammation, which leads to neurodegenerative diseases and brain cancer. To date, there are no specific or effective therapeutic agents to control inflammation and alleviate cadmium-induced progressive destruction of brain cells. Fluoroquinolones (FQs), widely used antimicrobials with effective blood-brain barrier penetration, show promise in being repurposed as anti-inflammatory drugs. Therefore, we aimed to test the efficacy of repurposed FQs for the treatment of cadmium-induced inflammation using cultures of U-87 MG human astrocytes and primary human astrocytes. Both FQs abrogated cadmium-induced interleukin (IL)-6 and IL-8 release from human astrocytes in a concentration and time-dependent manner, although levofloxacin had a stronger inhibitory effect than moxifloxacin. The downregulation of inflammatory cytokine release occurred with a concomitant reduction in cadmium-induced elevations in p65 nuclear factor-κB (NF-κB) and extracellular signal-regulated kinases (ERKs) 1/2 phosphorylation. Additionally, levofloxacin treatment significantly alleviated cadmium-induced activation of phosphorylated NF-κB translocation and toll-like receptor (TLR)-4/signal transducer and activator of transcription (STAT) 3 signaling. Transcriptome analysis revealed that modulation of inflammation-related pathways was the most enriched after FQ treatment. Our data suggest that FQs, particularly levofloxacin, attenuate the inflammatory process mediated by cadmium in human astrocytes. These effects may be mediated, at least in part, by inhibition of immune pathways regulated by TLR4, STAT3, ERK MAPK, and NF-κB.

Characterization of Thin Polymer Layer Prepared from Liposomes and Polyelectrolytes for TGF-β3 Release in Tissue Engineering.

Implant-integrated drug delivery systems that enable the release of biologically active factors can be part of an in situ tissue engineering approach to restore biological function. Implants can be functionalized with drug-loaded nanoparticles through a layer-by-layer assembly. Such coatings can release biologically active levels of growth factors. Sustained release is desired for many in vivo applications. The layer-by-layer technique also allows for the addition of extra layers, which can serve as "barriers" to delay the release. Electrospun Polycaprolactone (PCL) fiber mats are modified with a Chitosan (CS) grafted with PCL sidechains (CS-g-PCL24) and coated with transforming growth factor beta 3 (TGF-β3) loaded Chitosan/tripolyphosphate nanoparticles as a drug delivery system. Additional layers including polystyrene sulfonate, alginate, carboxymethyl cellulose, and liposomes (phosphatidylcholine) are applied. Streaming potential and X-ray photoelectron spectroscopy (XPS) measurements indicated a strong interpenetration of the chitosan and polyanion layers, while liposomes formed separate layers, which are more promising for sustained release. All samples release TGF-β3 at different cumulative levels without altering release kinetics. Variations in layer structure, interpenetration, and stability depending on the chitosan used are observed, which ultimately has minimal impact on the release kinetics. Polyelectrolyte layers strongly interpenetrated the active layers and therefore do not act as effective diffusion barriers, while the liposome layer, though separated, lacked sufficient stability.

Impacts of β-diketonate terminal ligands on slow magnetic relaxation and luminescence thermometry in dinuclear DyIII single-molecule magnets.

Lanthanide-based Single-Molecule Magnets (SMMs) with optical and magnetic properties provide a means to understand intrinsic energy levels of 4f ions and their influence on optical and magnetic behaviour. Fundamental understanding of their luminescent and slow relaxation of the magnetization behaviour is critical for targeting and designing SMMs with multiple functionalities. Herein, we seek to investigate the role of DyIII coordination environment and fine electronic structure on the slow magnetic relaxation and luminescence thermometry. Our findings are illustrated through two distinct DyIII complexes, [Dy2(bpm)(hexd)6] (1) and [Dy2(bpm)(hpd)6] (2), (bpm = 2,20-bipyrimidine, hexd = 2,4-hexanedione, hpd = 3,5-heptanedione), by comparing their features with a family of DyIII dinuclear species bridged by bpm. These findings highlight that the hexd- and hpd- ligands exhibit a similar effective barrier to the reversal of magnetization (280-290 K). The values are among the highest for dinuclear DyIII complexes bridged by bpm, due to the low distortion of the DyIII coordination polyhedra and the long Dy-N equatorial bonds. Furthermore, the luminescence performance is affected by the triplet state energy of the terminal ligand, influencing ligand-to-DyIII energy transfer. The hpd- ligand's higher T1 state energy leads to poor ligand-to-DyIII energy transfer, limiting the use of 2 for luminescence thermometry. Conversely, this issue is absent in 1, which offers a relative thermal sensitivity of 0.1 to 0.7% K-1 (10 to 60 K) with a temperature uncertainty below 1 K. These findings contribute to our understanding of lanthanide-based SMMs and facilitate the design of multifunctional materials with tailored magnetic and luminescent properties for molecular electronics and beyond.

First-Principles Assessment of ZnTe and CdSe as Prospective Tunnel Barriers at the InAs/Al Interface.

Majorana zero modes are predicted to emerge in semiconductor/superconductor interfaces, such as InAs/Al. Majorana modes could be utilized for fault tolerant topological qubits. However, their realization is hindered by materials challenges. The coupling between the superconductor and the semiconductor may be too strong for Majorana modes to emerge, due to effective doping of the semiconductor by the metallic contact. This could be mediated by adding a tunnel barrier of controlled thickness. We use density functional theory (DFT) with Hubbard U corrections, whose values are machine-learned via Bayesian optimization (BO), to assess ZnTe and CdSe as prospective tunnel barriers for the InAs/Al interface. The results of DFT+U(BO) for ZnTe are validated by comparison to angle resolved photoemission spectroscopy (ARPES). We then study bilayer interfaces of the three semiconductors with each other and with Al, as well as trilayer interfaces with a varying number of ZnTe or CdSe layers inserted between InAs and Al. We find that 16 atomic layers of either material completely insulate the InAs from metal induced gap states (MIGS). However, ZnTe and CdSe differ significantly in their band alignment, such that ZnTe forms an effective barrier for electrons, whereas CdSe forms a barrier for holes. Because of Fermi level pinning in the conduction band at the interface, only electron transport is relevant for InAs-based Majorana devices. Therefore, ZnTe is the better choice. Based on the results of our simulations, we suggest conducting experiments with ZnTe barriers in the thickness range of 6-18 atomic layers.

Theoretical Investigations on the Molecular Magnetic Behavior of Actinide Molecules [AnPc2]0/- (An = U, Cf): Prediction of the High Magnetic Blocking Barrier and Magnetic Blocking Temperature in [CfPc2

Searching for single-molecule magnets (SMM) with large effective blocking barriers, long relaxation times, and high magnetic blocking temperatures is vitally important not only for the fundamental research of magnetism at the molecular level but also for the realization of new-generation magnetic memory unit. Actinides (An) atoms possess extremely strong spin-orbit coupling (SOC) due to their 5f orbitals, and their ground multiplets are largely split into several sublevels because of the strong interplay between the SOC of An atoms and the crystal field (CF) formed by ligand atoms. Compared to TM-based SMMs, more dispersed energy level widths of An-based SMMs will give a larger total zero field splitting (ZFS) and thus provide a necessary condition to derive a higher Ueff. In combination of the density functional theory (DFT) as well as the CF model Hamiltonian and ab initio calculation, we have investigated the structural stability and electronic structures as well as the magnetodynamic behavior of [AnPc2]0/- (An = U, Cf) molecules. We find that An atoms can strongly interact with its ligand N atoms in forming An-N ionic bonds, and 5f electrons are more localized in the Cf atom than in the U atom, giving U4+(5f2) and Cf3+(5f9) valence states. Although the UPc2 molecule has a modest value of Ueff = 514 cm-1, it is not a good SMM due to the easy occurrence of quantum tunneling of magnetization (QTM). Based on the consistent results of CF Hamiltonian and ab initio calculations on the [CfPc2]- molecule, we propose that almost prohibited QTM within the Kramers doublets (KDs) as well as very low transition probabilities between different states via hindered spin-flip transitions would result in a high Ueff = 1401 cm-1. The estimated high magnetic blocking temperature (TB) of 58 K renders [CfPc2]- an excellent SMM candidate, implying that magnetic hysteresis could be observed in future experiments.

Study of Corrosion of Portland Cement Embedded Steel with Addition of Multi-Wall Carbon Nanotubes.

In this study, we research the innovative application of multi-walled carbon nanotubes (MWCNTs) as corrosion inhibitors in Portland cement embedded steel. The physicochemical properties of the dispersion solutions were evaluated, varying the storage time, to analyze their effect on corrosion resistance. Using a dispersion energy of 440 J/g and a constant molarity of 10 mM, stable dispersions were achieved for up to 3 weeks. These dispersions were characterized using Raman spectroscopy, UV-Vis spectroscopy and Zeta potential spectroscopy to assess the stability and structural damage of the MWCNTs. These results show that the addition of MWCNTs not only reduces the porosity of the cement matrix, but also forms an effective barrier against chloride ion intrusion, protecting the reinforcing steel. This approach stands out for combining improved mechanical properties and significant corrosion resistance, representing a promising innovation in the development of more durable construction materials.

Protective film on cerium metal through in-situ formation of a dense CeO2 oxide layer using air plasma

The rapid spontaneous oxidation of cerium in the atmospheric environment is reported to be attributed to its porous oxide structure, and there is a scarcity of strategies for enhancing its corrosion resistance. In this study, a dense ceria layer was fabricated in situ on the surface of cerium using a simple plasma process method, which significantly improved its resistance to drastic oxidation in air. By subjecting the cerium sample to plasma treatment in air for 400 s, a dense surface CeO2 layer with a thickness of approximately 1 μm was formed. Compared with untreated cerium metal samples, no significant changes were observed in terms of surface morphology and composition characteristics even after exposure to atmospheric conditions for up to 60 days. Theoretical calculations have demonstrated that the presence of a relatively stable CeO2 layer serves as an effective barrier against water adsorption/dissociation and particularly inward diffusion of hydrogen, thereby preventing their penetration into bulk cerium. The utilization of plasma method for generating a homogeneous surface oxide layer without introducing additional metal elements presents a novel strategy for protecting active metals exhibiting poor air corrosion resistance

A fluorobenzene-bound dysprosium half-sandwich dication single-molecule magnet.

Dysprosium single-molecule magnets (SMMs) with two mutually trans-anionic ligands have shown large crystal field (CF) splitting, giving record effective energy barriers to magnetic reversal (U eff) and hysteresis temperatures (T H). However, these complexes tend to be bent, imposing a transverse field that reduces the purity of the m J projections of the CF states and promotes magnetic relaxation. A complex with only one charge-dense anionic ligand could have more pure CF states, and thus high U eff and T H. Here we report an SMM with this topology, a half-sandwich Dy(iii) complex [Dy(Cp*)(FPh)6][{Al[OC(CF3)3]3}2(μ-F)]2 (1-Dy; Cp* = C5Me5), and its Y(iii) analogue 1-Y; 1-Dy exhibits U eff = 545(30) cm-1 and T H = 14 K at sweep rates of 22 Oe s-1. The Cp* ligand imposes a strong axial CF, which is assisted by one axial fluorobenzene; the five equatorially-bound neutral fluorobenzenes present only weak transverse interactions to give a pseudo-pentagonal bipyramidal geometry. The salt metathesis reaction of 1-Y with KCp''' (Cp''' = {C5H2(SiMe3)3-1,2,4}) gave the sandwich complex [Y(Cp''')(Cp*)(FPh)2][{Al[OC(CF3)3]3}2(μ-F)] (4-Y), showing that the fluorobenzenes of 1-Y are easily displaced. We envisage that these methodologies could be adapted in future to prepare high-performance axial Dy SMMs with ligands that are more sterically demanding than Cp*.

Unravelling the electronic structure, bonding, and magnetic properties of inorganic dysprosocene analogues [Dy(E4)2]- (E = N, P, As, CH).

Organometallic sandwich complexes of Dy(III) ion are ubiquitous for designing high-temperature single-ion magnets with blocking temperatures close to the liquid nitrogen boiling point. Magnetic bistability at the molecular level makes them potential candidates for nano-scale information storage materials. In the present contribution, we have thoroughly investigated the electronic structure, bonding, covalency, and magnetic anisotropy of inorganic dysprosocene complexes with a general formula of [Dy(E4)2]- (where E = N, P, As, CH) using state-of-the-art scalar relativistic density functional theory (SR-DFT), and a multiconfigurational complete active space self-consistent field (CASSCF) method with the N-electron valence perturbation theory (NEVPT2). Geometry optimization calculations predict stabilization of the [Dy(E4)2]- complexes with a linear geometry and D4h local symmetry Dy(III) ion in [Dy(N4)2]- (1) and [Dy(P4)2]- (2) complexes, while a bent geometry has been observed for the [Dy(As4)2]- (3), [Dy(P2(CH)2)2]- (4), and [Dy(As2(CH)2)2]- (5) complexes. Energy decomposition analysis (EDA) and natural bonding orbital (NBO) calculations reveal sizable 5d-ligand covalency followed by 6s/6p and weak 4f-ligand covalency in complexes 1-5. Both the natural localized molecular orbitals (NLMOs) at the DFT level and ab initio-based ligand field theory (AILFT) at the NEVPT2 level of theory predict an increase in the Dy-ligand covalency as we move from N to As. Spin-Hamiltonian parameter analysis of complexes 1-5 reveals stabilization of the mJ |±15/2〉 as the ground state with highly axial g values (gxx ∼ gyy ∼ 0 and gzz ∼ 20) and the barrier height of 2902, 1214, 1104, 1845, and 1509 K for 1-5, respectively. The Orbach effective demagnetization barrier (Ueff) for complexes 1-5 ranges between 2416-1175 K, with a record Ueff value of 2416 K observed for 1. In addition, we have explored the role of heavy element effects on the magnetic anisotropy by turning off the spin-orbit coupling of the pnictogens (N, P, and As), and our calculations clearly predict that heavy atoms in the first coordination sphere help in increasing the barrier height for magnetic relaxation. Heavy elements like P and As significantly enhance the SOC contributions, thereby providing a platform for designing and optimizing Dy(III) complexes with tailored magnetic behaviors.

Evaluation of the digestion protocol of mouse neonatal epidermis for single-cell RNA sequencing.

The skin is primarily composed of keratinocytes and forms an effective barrier between the organism and external environment. Neonatal skin analysis is essential for understanding developmental processes and rare skin diseases. However, efficient single-cell dissociation methods for the neonatal mouse epidermis remain underexplored. Here, three enzymes (Trypsin, TrypLE, and Liberase) used for tissue dissociation were compared to optimize single-cell RNA sequencing (scRNA-seq) of the mouse neonatal epidermis. scRNA-seq revealed distinct differences in cell recovery between the enzymes, with Liberase enriching suprabasal keratinocytes and Trypsin/TrypLE favoring basal keratinocytes. Although all enzymes produced comparable data quality, the observed bias in cell population recovery highlights the significant impact of dissociation protocols on the scRNA-seq results. These findings highlight the importance and optimal selection of enzymes for the analysis of unbiased neonatal epidermis.

Enhancing Water Barriers by Protein-Based Surface Treatments for Cellulose-Based Materials

ABSTRACT The global packaging sector has grown consistently, and the use of sustainable materials, including recycled and biodegradable products, is expected to rise. This study focuses on the potential of producing barriers for water and water in moist air (water vapor) from proteins to protect cellulosic materials. Owing to the specific requirements of packaging materials, the main subject of this research was their barrier and strength properties. The scope of this work includes selecting components and their physicochemical treatment to produce functionalized coatings on sprayed paper and pure films, as well as film-coated samples (paper laminated with film). The following tests were used to estimate the hydrophobic, hygroscopic, and strength properties: Cobb absorption, contact angle testing, dynamic vapor sorption, and dynamic mechanical analysis. In most cases, the spray-coated paper and film-coated samples absorbed less liquid water than untreated paper. Wheat gluten protein was the most effective water barrier. In all variants, the vapor sorption, desorption, and hysteresis effects (or the lack thereof) showed significant differences compared to those of cellulosic materials. All variants of the spray-coated and film-coated samples in the dynamic mechanical analysis showed an increase in the strength properties of the samples in comparison to the untreated paper. The increased humidity caused a significant loss in the mechanical properties of all variants, exceeding the strength loss of the untreated control samples.

Tailoring Polyelectrolyte Multilayer Nanofiltration Membranes by Aerosol-Assisted Printing: Insights into Membrane Formation Mechanisms.

Polyelectrolyte multilayer (PEM) membranes, with advantageous features of versatile chemistry and structures, are driving the development of advanced nanofiltration (NF) membranes with exceptional performance. While developing a printing method holds great promise for the eventual mass production of these membranes, reports on the printing method and the underlying mechanisms of membrane formation are currently scarce. Herein, we develop an aerosol-assisted printing (AAP) system for fabricating PEM NF membranes with highly tunable separation characteristics. Our study unveils the three stages of membrane formation from assembly of polyethylenimine (PEI) and poly(sodium 4-styrenesulfonate) (PSS): aerosol deposition, single PE layer formation, and PEM assembly. The droplet deposition is governed by inertial impaction, and the deposited PEs migrate/entangle to form a single PE layer. The thicknesses of the PE layer and PEM exhibit linear growth as the number of printing scan increases. Furthermore, PE interdigitation forms an effective polymeric network barrier, which increases the resistance to solute and water transport. By manipulating the PE deposition mass and layering, PEM membranes with tunable pore radii (0.40-0.56 nm) and water permeability (5-60 L·m-2·h-1·bar-1) were obtained for various water treatment applications, ranging from micropollutant removal to humic acid filtration. Our study offers valuable mechanistic insights into the PEM formation and precise structural adjustment via printing, thus facilitating scalable manufacturing and widespread applications of the PEM NF membranes.

Interfacial polarization charge engineering with co-designed LQB and EBL for enhanced EQE of AlGaN DUV LEDs

Abstract In this paper, we propose to modulate the polarization charges at the interface between the last quantum barrier (LQB) and the electron blocking layer (EBL) via strategically adjusting the Al composition in the LQB and EBL simultaneously. With appropriate design of the linear gradient profile in Al composition, the original positive polarization charges at the LQB/EBL interface can be diminished or converted into negative charges, which helps to reduce the positive electric field in EBL, thus adjusting the energy band near the LQB/EBL interface. Enhanced effective barrier height for electrons, decreased effective barrier height for holes, and accumulation of a large number of holes at the LQB/EBL interface are obtained, resulting in improved electron leakage and hole injection. In comparison with the reference deep ultraviolet light-emitting diode (DUV LED), an enhanced external quantum efficiency by 37.5% at an injection current density of 100 A cm−2 is achieved for the device with negative polarization charges. The modulation strategy of polarization charges at the LQB/EBL interface via co-designing the linear gradient of Al composition in LQB and EBL can be a feasible approach for obtaining high-performance DUV LEDs.

Investigation of Hydrogen Transport Behavior in Polyethylene Terephthalate Membrane by Prolonged Hydrogen Exposure Treatments

Polyethylene terephthalate (PET) is one of the most used polymeric substances in production of packaging materials, fibers, textiles, coatings, and engineering materials. This paper elucidates the transport parameters of hydrogen gas through a PET membrane, which was selected to be a sufficiently permeable substrate for setting up an empirical strategy that aims at developing hydrogen barrier coatings. An examination of the structural degradation of PET by prolonged hydrogen exposure was performed. Hydrogen permeation tests were performed on a PET membrane with a thickness of 50 μm. To investigate the behavior of the material by prolonged hydrogen treatment, hydrogen-exposure experiments were carried out at a certain hydrogen pressure and time. Comparisons of the mechanical properties of the material were documented both before and after hydrogen exposure. A strong impact of comparatively transient hydrogen exposure on the mechanical and hydrogen transport properties of PET was observed. After 72 h of hydrogen exposure at 103 hPa and 300 K, the tensile strength decreased by 19%, the diffusion coefficients more than doubled, and material fracture behavior changed from ductile to distinctly brittle. This underlines the importance of developing effective hydrogen barrier coatings in case PET tubing is intended for use in hydrogen transport or storage.

Predicting Magnetic Barriers in Lanthanide Complexes with Electrostatic Potential Charges.

Single-molecule magnets (SMMs) with slow relaxation of magnetization and blocking temperatures above that of liquid nitrogen are essential for practical applications in high-density data storage devices and quantum computers. A rapid and accurate prediction of the effective magnetic relaxation barrier (Ueff) is needed to accelerate the discovery of high-performance SMMs. Using density functional theory and multireference calculations, we explored correlations between Ueff, partial atomic charges, and the anisotropic barrier for a series of sandwich-type lanthanide complexes containing cyclooctatetraene, substituted cyclopentadiene, phospholyl, boratabenzene, or borane ligands. Our results show a correlation between the electrostatic potential charge of the lanthanide ion in the complex and Ueff. Systematic ligand modifications show that reducing ligand nucleophilicity and incorporating soft bases enhance magnetic anisotropy and Ueff values. This work identifies a correlation to predict Ueff values and optimization of ligand coordination environments in lanthanide-based SMMs.

Assessing barriers of automation and robotics adoption in the Indian construction industry: a fuzzy DEMATEL approach

Purpose Despite global advancements, the Indian construction industry lags in adopting technologies like robots, artificial intelligence, drones, unmanned ground vehicles and Internet of Things sensors due to various barriers. This reliance on traditional practices leads to persistent issues such as labour shortages, low productivity, safety risks, cost overruns and delays. Identifying and addressing these barriers is crucial for adopting advanced technologies. Hence, this study aims to identify and assess the influential barriers to construction automation and robotics (AaR) in India using a systematic approach. Design/methodology/approach An extensive literature review identified key barriers, including technological, financial, regulatory, environmental and organisational. A questionnaire survey was conducted among industry professionals, and the Fuzzy Decision-Making Trial and Evaluation Laboratory technique was used to evaluate the interrelationships and relative significance of these barriers. Findings The results of the study reveal the most critical cause barriers as “high initial cost”, “rigidity in organisational processes and procedures”, “interoperability”, “lack of competency” and “lack of standardisation”. These barriers subsequently influence the top two effect barriers such as “market uncertainty” and “ethical concerns”. Practical implications This research offers a systematic and quantitative assessment, enabling stakeholders to make informed decisions and develop strategies to overcome barriers to AaR adoption, unlocking the transformative potential of AaR in India’s construction sector. Originality/value Despite potential benefits, the adoption of AaR in Indian construction remains limited due to various barriers. This study provides novel insights with the first comprehensive assessment of these barriers and their interrelationships.

3D-Printed Hydrogel Scaffolds Loaded with Flavanone@ZIF-8 Nanoparticles for Promoting Bacteria-Infected Wound Healing.

Bacterial-infected skin wounds caused by trauma remain a significant challenge in modern medicine. Clinically, there is a growing demand for wound dressings with exceptional antibacterial activity and robust regenerative properties. To address the need, this study proposes a novel multifunctional dressing designed to combine efficient gas exchange, effective microbial barriers, and precise drug delivery capabilities, thereby promoting cell proliferation and accelerating wound healing. This work reports the development of a 3D-printed hydrogel scaffold incorporating flavanone (FLA)-loaded ZIF-8 nanoparticles (FLA@ZIF-8 NPs) within a composite matrix of κ-carrageenan (KC) and konjac glucomannan (KGM). The scaffold forms a stable dual-network structure through the chelation of KC with potassium ions and intermolecular hydrogen bonding between KC and KGM. This dual-network structure not only enhances the mechanical stability of the scaffold but also improves its adaptability to complex wound environments. In mildly acidic wound conditions, FLA@ZIF-8 NPs release Zn2+ and flavanone in a controlled manner, providing sustained antibacterial effects and promoting wound healing. In vivo studies using a rat full-thickness infected wound model demonstrated that the FLA@ZIF-8/KC@KGM hydrogel scaffold significantly accelerated wound healing, showcasing its superior performance in the treatment of infected wounds.

Analysis of Fatigue Crack Propagation in AISI 4140 Steel with Multi-Austempering Treatment

This study examines the fatigue crack propagation behaviour of AISI 4140 steel subjected to multi-austempering heat treatments. Tensile test and fatigue crack propagation (FCP) specimens were prepared in accordance with ASTM E8 and ASTM E647, respectively. Multi-austempering was carried out by heating the specimen to an austenite temperature for 10 min using an induction heating coil. The specimen was then immersed in a salt bath for each isothermal transformation time of 60 min at three austempering temperature levels from 312°C to 412°C with a temperature increase of 50°C. Tensile and fatigue crack growth tests were performed on both annealed and multi-austempered specimens. It is observed that the multi-austempering heat treatment significantly improves the tensile properties and the FCP properties of AISI 4140 steel. Microstructural observations indicate that the bainitic phase and the retained austenite increase the tensile strength and reduce the fatigue crack propagation rate (da/dN). It is found that the bainitic structures are an effective barrier in reducing fatigue crack propagation as the fatigue loading cycle increases

Root apoplastic barrier mechanism: an adaptive strategy to protect against salt stress.

From soil to plant, the water and ions, enter the root system through the symplast and apoplast pathways. The latter gains significance under salt stress and becomes a major port of entry of the dissolved salts particularly the sodium ions into the root vasculature. The casparian strip (CS), a lignified barrier circumambulating the root endodermal cells' radial and transverse walls regulates the movement of water and solutes in and out of the stele. The development of CS begins with the synthesis of a protein scaffold made of CASPARIAN STRIP MEMBRANE DOMAIN PROTEINs (CASPs), followed by lignin deposition involving the enzymatic machinery viz., ENHANCED SUBERIN 1 (ESB1), RESPIRATORY BURST OXIDASE HOMOLOG F (RBOHF), and PEROXIDASE 64 (PER64), etc. Towards maintaining the integrity of the CS, the CASPARIAN STRIP INTEGRITY FACTOR 1/2-SCHENGEN 3-SCHENGEN 1 (CIF1/2-SGN3-SGN1) signaling pathway has been found to play a significant role as a barrier surveillance system, the resultant is compensatory lignification of the radial and stele-facing transversal walls of endodermis. This leads to the formation of 'U' shaped lignified structures that enable an effective apoplastic barrier mechanism to prevent the influx of sodium ions into the stele. Rice, the major staple crop is generally classified as salt-susceptible, however, root cross-sectional anatomy of selected salt-tolerant genotypes exhibits an early and enhanced lignification of the endodermis. For instance, in the salt-tolerant landrace Mundan, the development of CS is accompanied by the formation of continuous 'U' shaped lignified structures along the endodermal walls under salt stress.

Effects of Interfacial Parameters and Temperature on Effective Schottky Barrier Height of Metal-Wrapped (Al-Gan) Nanowire Schottky Diode

Junction interface parameters (interface states density, interface layer thickness, interface permittivity and neutral surface states) and temperature effects have been studied. Results have shown that for the scaled structure doping functions below degeneracy state and temperature have significant impact on the effective Schottky barrier height while the interface parameters show no significant change. The barrier height has been observed to increase as the temperature increases almost linearly by ~5.171×10-3eV with increase in temperature from 300K to 420 K and this may be associated with the avalanched charge carriers being transported across the barrier height. The interface layer thickness in the range of 1.5 nm to 3.0 nm shows no effect on the carrier transport characteristics curves of the Schottky diode whereas the ideality factor has been found to decrease with an increase in temperature.