Resistive Research Articles

Tarm1 may affect colitis by regulating macrophage M1 polarization in a mouse colitis model.

In this study, we aimed to explore the role of Tarm1 in juvenile mice with dextran sulfate sodium (DSS)-induced colitis and elucidate the mechanisms that affect intestinal barrier function. A DSS-induced pediatric inflammatory bowel disease mouse model was established using 4-week-old juvenile mice. Disease activity index and histopathological damage scores were determined using hematoxylin and eosin (H&E) staining. Tarm1, F4/80, CD68, and CD86 levels were detected using qPCR, western blotting, and immunofluorescence. Trans epithelial electric resistance (TEER) was detected using the transwell assay. Results revealed that juvenile colitis mice fed 4% DSS drinking water had increased Tarm1 expression in the colon tissue, increased macrophage M1 polarization, higher expression of pro-inflammatory cytokines, and an impaired intestinal mucosal barrier, compared with the control group. Tarm1-knockdown RAW264.7 cells inhibited lipopolysaccharide (LPS)-induced M1 polarization and attenuated barrier damage in co-cultured intestinal epithelial cells. Tarm1 expression was increased in colonic tissues of juvenile mice with colitis, and LPS-induced M1 polarization and intestinal barrier damage were attenuated in Tarm1-knockdown RAW264.7 cells. This suggests that attenuation of Tarm1 expression is a potential target for pediatric inflammatory bowel disease therapy.

Comprehensive investigation of gas hold-up in a double coaxial mixer with shear-thinning fluids exhibiting yield stress: Experimental, numerical, and artificial neural network approaches

This study addresses the challenge of uneven gas dispersion in yield-stress, non-Newtonian fluids, commonly encountered in industries such as biopharmaceuticals, cosmetics, and food processing. While previous research demonstrated the advantages of dual coaxial mixers for pseudoplastic fluids, limited attention has been given to aerating yield-pseudoplastic fluids with higher aspect ratios. This study bridges that gap by investigating both local and global gas hold-up under various conditions, utilizing electrical resistance tomography and computational fluid dynamics. Key findings showed that increasing the anchor speed from stationary to 30 rpm significantly enhanced aeration efficiency (gas hold-up per specific power consumption), with improvements of 78 % in UP-CO mode and 25 % in UP-COUNTER mode at Nc = 350 rpm and Qg = 20 L/min. These results underscore enhanced gas dispersion under specific operating conditions, driving overall process intensification. To ensure accurate prediction of gas hold-up, both dimensional and dimensionless empirical correlations, along with an artificial neural networks (ANNs) model, were developed. The ANNs model exhibited superior accuracy, achieving R² values of 0.99 for both rotation modes, outperforming empirical models, which achieved R² values of 0.90 and 0.89 for UP-CO and UP-COUNTER modes, respectively.

A novel photocurable polymeric solid–solid phase change material for intelligent temperature regulators

The advancement of solid–solid phase change materials (SSPCMs) with crystalline segments embedded onto crosslinked polymer backbones offers a promising solution to the leakage problems associated with traditional phase change materials. Despite its potential, this technology faces challenges, including energy-intensive synthesis processes of SSPCMs and difficulties in custom designing materials for confined spaces. Herein, we introduce a novel strategy for the rapid preparation of polyurethane acrylate-based SSPCMs via UV-initiated polymerization. By leveraging crystalline segments from polyethylene glycol, the resulting SSPCM exhibits an impressive enthalpy of 110.4 J⋅g−1, enabling seamless transitions from rigid to soft states during solid–solid phase changes. When applied in portable electronic devices, this SSPCM can be synthesized in-situ to meet various size requirements, demonstrating exceptional temperature regulation performance based on latent thermal energy storage mechanisms. Furthermore, by integrating thin layers of carbon nanotubes (CNTs) onto the rough surfaces of SSPCM films and employing a face-to-face configuration to convert temperature-sensitive mechanical changes into electric resistance variations, we have engineered high-temperature alarms for SSPCM-based temperature regulators. The advantages of this preparation strategy, combined with the thermal regulation capabilities and innovative temperature alarm design, underscore the significant potential for intelligent and adaptive applications of SSPCMs in advanced technological landscapes.

Structure and Properties of the Electroexplosive Coating of the TiB2-Ag System after Electron Beam Treatment

A coating of the TiB2-Ag system was formed through the use of sequential operations of electroexplosive spraying and electron beam processing. The values of electrical conductivity (62.0 MS/m), Vickers microhardness (0.251-0.265 GPa at the point of measurement on a silver matrix and 25-32 GPa at the point of measurement at inclusions of boride phases), nanohardness (4.48 ± 0.76 GPa) were determined), Young’s modulus (116±29 GPa), wear parameter under dry friction-sliding conditions (1.2 mm3/N • m) and friction coefficient (0.5). Switching wear resistance during accelerated tests was 7000 on and off cycles with an electrical resistance of 10.01 - 11.76 LiOhm. The thickness of the coatings is 100 microns. The coatings are formed by a silver matrix with inclusions of titanium borides located in it with three types of sizes: nanocrystalline, submicrocrystalline and microcrystalline. Quantitatively, in the structural composition among titanium borides, titanium diboride and silver (56 wt. %) are formed predominantly (41 wt. %), while other titanium borides account for 3 wt. %. Structural transformations are described using complementary methods of X-ray phase analysis, scanning and transmission electron microscopy.

Comprehensive Advanced Physicochemical Characterization and In Vitro Human Cell Culture Assessment of BMS-202: A Novel Inhibitor of Programmed Cell Death Ligand

Background/Objectives: BMS-202, is a potent small molecule with demonstrated antitumor activity. The study aimed to comprehensively characterize the physical and chemical properties of BMS-202 and evaluate its suitability for topical formulation, focusing on uniformity, stability and safety profiles. Methods: A range of analytical techniques were employed to characterize BMS-202. Scanning Electron Microscopy (SEM) was used to assess morphology, Differential Scanning Calorimetry (DSC) provided insights of thermal behavior, and Hot-Stage Microscopy (HSM) corroborated these thermal behaviors. Molecular fingerprinting was conducted using Raman spectroscopy and Fourier Transform Infrared (FTIR) spectroscopy, with chemical uniformity of the batch further validated by mapping through FTIR and Raman microscopies. The residual water content was measured using Karl Fisher Coulometric titration, and vapor sorption isotherms examined moisture uptake across varying relative humidity levels. In vitro safety assessments involved testing with skin epithelial cell lines, such as HaCaT and NHEK, and Transepithelial Electrical Resistance (TEER) to evaluate barrier integrity. Results: SEM revealed a distinctive needle-like morphology, while DSC indicated a sharp melting point at 110.90 ± 0.54 ℃ with a high enthalpy of 84.41 ± 0.38 J/g. HSM confirmed the crystalline-to-amorphous transition at the melting point. Raman and FTIR spectroscopy, alongside chemical imaging, confirmed chemical uniformity as well as validated the batch consistency. A residual water content of 2.76 ± 1.37 % (w/w) and minimal moisture uptake across relative humidity levels demonstrated its low hygroscopicity and suitability for topical formulations. Cytotoxicity testing showed dose-dependent reduction in skin epithelial cell viability at high concentrations (100 µM and 500 µM), with lower doses (0.1 µM to 10 µM) demonstrating acceptable safety. TEER studies indicated that BMS-202 does not disrupt the HaCaT cell barrier function. Conclusions: The findings from this study establish that BMS-202 has promising physicochemical and in vitro characteristics at therapeutic concentrations for topical applications, providing a foundation for future formulation development focused on skin-related cancers or localized immune modulation.

Experimental study of hydrodynamic characteristics in three-phase coarse particle fluidized flotation column

Understanding multiphase flow regimes and hydrodynamic characteristics in the three-phase coarse particle fluidized flotation column (TFC) is crucial in mineral processing. This study systematically investigated the influence of gas velocity (Ug) and water velocity (Uw) on the flow regimes in TFC, focusing on the identification and hydrodynamic characteristics of different flow regimes in the freeboard and bulk fluidized bed regions. Three distinct flow regimes (heterogeneous flow, pseudo-homogeneous flow and mono-homogeneous flow) and two transition water velocities (transitions from a heterogeneous flow regime to a pseudo-homogeneous flow (Ut1) and transitions from a pseudo-homogeneous flow to a mono-disperse homogeneous flow regime (Ut2)) were identified in the freeboard region based on the visual observation and bubble characteristic parameter acquisition system (BVW-2) monitoring the variations in the bubble size distribution. Visual observation combined with electrical resistance tomography (ERT) monitoring the solid concentration variations facilitated accurate determination of three flow regimes (fixed bed regime, agitated bed regime, and complete fluidization regime) and two transition points (minimum agitation water velocity (ULma) and minimum fluidization water velocity (ULmf)) in the bulk fluidized bed region. Furthermore, statistical and spectral methods were used to analyze pressure fluctuation signals and characterize fluidization behavior across different flow regimes, including the average pressure fluctuation (ΔP¯), the probability density function (PDF), normalized standard deviation (δ), kurtosis (K), skewness (S), autocorrelation function (ACF), power spectral density (PSD) and average cycle frequency (fc). The results indicated that it is the changes in dominant flow structures within the three-phase fluidized bed, such as variations in bubble behavior and particle movement under different Ug and Uw, that lead to differences in flow characteristics, thereby forming distinct flow regimes.

Tumor cell extracellular vesicles derived long non-coding RNA X-inactive specific transcript regulates the blood–brain barrier and non-small cell lung cancer brain metastasis via miR-19b-3p/EPN2

ObjectiveTo investigate the function of tumor cell extracellular vesicles (EVs) derived long non-coding RNA X-inactive specific transcript (XIST) in non-small cell lung cancer (NSCLC) brain metastasis and to clarify its specific mechanism. MethodsEVs were isolated from A549 cells, and transmission electron microscopy, nanoparticle tracking, and western blotting were used to detect morphology and particle size of EVs. Human brain microvascular endothelial cells (HBMEC) and astrocytes were used to construct an in vitro blood–brain barrier (BBB) model. The BBB model was treated with EVs for 24 h. PKH67 staining was performed to examine EV engulfment by HBMEC and astrocytes. RT-qPCR was used to examine XIST, miR-19b-3p, and epsin 2 (EPN2) mRNA expression. Expression of EPN2 and tight junction (TJ) proteins such as claudin-5, occludin, and ZO-1 were measured using western blotting. Transepithelial electrical resistance (TEER), rhodamine-dextran, and immunofluorescence staining were performed to explore the effects of EVs and XIST on the BBB. Transwell assay was used to evaluate the invasive ability of A549 and H1299 cells. Dual-luciferase and immunoprecipitation assays were used to verify binding between miR-19b-3p, XIST, and EPN2. The Interactive Video Information System was used to observe brain metastasis of xenografts in BALB/c nude mice. ResultsA549 cell-derived EVs exhibited typical characteristics of EVs. HBMEC ingested EVs in the BBB model. EVs treatment decreased TEER and TJ protein level and increased the permeability to rhodamine-dextran. XIST was overexpressed in A549 and H1299 cells. Knockdown of XIST in A549 cell-derived EVs alleviated BBB damage and reduced NSCLC cell invasion. In vivo, XIST inhibition repressed NSCLC brain metastasis by ameliorating the BBB. Mechanistically, XIST sponged miR-19b-3p and positively regulated EPN2 expression. miR-19b-3p inhibition weakened the protective effect of XIST inhibition on the BBB. ConclusionA549 cells EVs-derived XIST inhibition ameliorates BBB injury and inhibits NSCLC brain metastasis by regulating the miR-19b-3p/EPN2 axis.

Modulating the anti-inflammatory and barrier protective effects on intestinal epithelial cells utilizing an aqueous Aspalathus linearis extract in vitro

BackgroundRooibos is a natural herbal plant containing numerous unique polyphenols which have been associated with certain health benefits. Several of these bioactive constituents have been linked to promoting gut health through its beneficial actions such as anti-inflammatory and anti-spasmodic characteristics. PurposeThe study aims to compare the anti-inflammatory and barrier protective effects of an unfermented and fermented rooibos aqueous extract on intestinal porcine epithelial cells (IPEC-J2). MethodsAqueous extracts of unfermented and fermented rooibos were prepared, and chemical and antioxidant analysis were performed of each extract. Intestinal porcine epithelial cells (IPEC-J2) were pre-treated with either unfermented or fermented aqueous rooibos extracts (0.1 and 0.05 mg/ml) then exposed to 10 µg/ml of Escherichia coli lipopolysaccharide (LPS). Cell viability, protein and gene expression of pro-inflammatory cytokines were investigated to determine the anti-inflammatory effect of both extracts. Barrier integrity of IPEC-J2 was investigated by measuring the Transepithelial electrical resistance (TEER) and quantifying tight junction gene expression. ResultsBoth the unfermented and fermented rooibos extracts have significant anti-inflammatory properties by reducing pro-inflammatory cytokine production. Interestingly for certain genes (IL-8, IL-6, IL-1B and CCL20) the fermented extracts, specifically at 0.1 mg/ml, exhibited greater effectiveness by decreasing the expression after LPS-induced inflammation whilst for another gene (TNF-α) the unfermented extract at both concentrations was more efficient in decreasing expression and ultimately protecting the IPEC-J2 cells from inflammation. When evaluating the barrier integrity, 0.1 mg/ml of the unfermented rooibos extract showed the most significant barrier protective effects through upregulation of tight junction proteins, ZO-1, Occludin as well as Claudin-4. ConclusionHigher concentration of the fermented rooibos extract prevented the inflammatory response significantly whilst the higher concentration of the unfermented rooibos extract enhanced tight junction expression and protected barrier integrity in LPS-induced inflamed intestinal cells. This is attributed to the differences in the polyphenol content of each extract and demonstrating the unique activity mechanisms of different rooibos extracts to reduce onset of early inflammation.

Enhanced Photovoltaic Efficiency through 3D-Printed COC/Al₂O₃ Anti-Reflective Coversheets

In the past few years, there has been a considerable growth in the utilization of solar cells to produce electrical power to fulfil the growing worldwide energy demands. An optical loss is a crucial factor that impacts the performance of the photovoltaic conversion process. This loss occurs when incoming sunlight is reflected back on the outer layer of the photovoltaic cells. The application of antireflective materials on the photovoltaic substrates can enhance the absorption of sunlight and minimize the reflection. Currently, there is no ideal anti-reflective coating for solar cells that can allow the transmission of sunlight without any reflection. In this research, a transparent cyclic-olefin-copolymer (COC) was used to fabricate anti-reflection (AR) coversheet by fused deposition modelling process (3D printing). Further, the aluminium oxide Al2O3 powder was added at the proportions of 1wt%, 2wt%, 3wt%, and 4wt% to the COC polymer to increase the anti-reflection characteristics. The structural, morphological, mechanical (tear strength), electrical and temperature characteristics were studied. The performance of COC with aluminium oxide (COCA) coversheets was evaluated, and the findings revealed a considerable increment in power conversion efficiency (PCE) of 17.21% (sunlight exposure) and 18.34% (neodymium light) for COCA3 coversheets. As seen, the COCA3 sample exhibit lower electrical resistance of 3.88 ×10-3 Ω cm, carrier concentration (36.91×1020 cm-3) and higher hall mobility (13.67 cm2/Vs). The findings from the investigations demonstrated that the utilization of COC with Al2O3 powder (COCA) can be a suitable antireflective coversheet material for boosting the performance of polycrystalline silicon photovoltaic cells.

Polyethylene microplastic pollution changes the electrical resistance and thermal conductivity of loess soil.

While plastics provide convenience, they also endanger the safety of the natural environment. Microplastic pollution caused by plastic aging has become an urgent concern in public places. In order to study the effects of microplastics on soil physical properties, the electrical resistance and thermal conductivity of soils containing different polyethylene and moisture content were tested. The results show that polyethylene have two effects on soil electrical resistance: one is that the plastic particles increase electrical resistance, and the other is that the electrostatic field carried by the plastic particles reduces electrical resistance. The effect of the two factors is balanced by the content of polyethylene at 6-8%. When the polyethylene content of the soil was 6% and 10%, the coefficients of electrical resistance variation were 0.89, 0.67, 0.85, 0.96, 0.97, 0.99 and 0.95, 0.68, 0.71, 0.93, 0.95, 0.96, respectively. Polyethylene alters soil properties by affecting water distribution through hydrophobicity. The water content gradually increases to 10%, the liquid conduction area inside the soil increases, and the higher the soil's ability to conduct electricity and heat. The results can provide theoretical reference for evaluating and controlling soil microplastic pollution.

ИЗМЕРЕНИЕ СОПРОТИВЛЕНИЯ ЛАКОКРАСОЧНОГО ПОКРЫТИЯ В ЭЛЕКТРОЛИТЕ

The use of known methods for measuring the electrical resistance of a protective coating in an electrolyte is associated with the danger of using high voltage, which accelerates degradation of the coating. The structural diagram of a measuring device operating at a low voltage of up to 1.5 V is substantiated. The device contains two galvanic cells with an electrolyte, a capacitor, a switch, a digital multimeter, and a three-position switch. One galvanic cell is attached to the coating on a carbon steel plate and is equipped with an electrode made of stainless steel. The second galvanic cell is equipped with electrodes made of carbon and stainless steel. It is a source of reference voltage. The input resistance of the multimeter from 1 MOhm serves as a reference resistance. The maximum value of the measured coating resistance reaches 1400 MOhm. A formula is obtained for calculating the specific electrical resistance of the paint and varnish coating in an electrolyte solution. Using the manufactured device, the dynamics of changes in the specific electrical resistance of two coatings made of Raptor polyurethane paint with a hardener are studied. The coatings were applied in two and three layers, the duration of testing in the borofoska solution was 200 days. Upon completion of the tests, the specific electrical resistance of the three-layer coating decreased from 480 to 20 MOhm∙m, it was 4 times greater than the two-layer coating. This result indicates a significant increase in the protective resistance of the polyurethane coating after applying the third layer.

Evaluating the Impact of Laundering on the Electrical Performance of Wearable Photovoltaic Cells: A Comparative Study of Current Consistency and Resistance

Wearable photovoltaic technology has been prominent in recent years because electronic devices need to be powered continuously without reliance on traditional methods. However, the practical adoption of wearable PV cells is hindered by the need for laundering, potentially degrading performance. This research compared PV cells’ maximum current and electrical resistance before and after laundering testing conditions. This study used eight samples of two types of PV panel cells and laundered them up to five cycles. The current and electrical resistance values were recorded before and after each laundering cycle. This study analyzed the data using a paired sample t-test and MANOVA. It was found that laundering cycles significantly affected the current values in both types of samples, with no differential impact between the types; on the other hand, laundering cycles did not significantly affect the electrical resistance values in both types of samples, with no differential impact between the types. These results are crucial for industries developing textile-based PV panels, where maintaining electrical performance after laundering is essential. These findings could pave the way for more sustainable, self-powered wearable PV technologies, ultimately transforming how users interact with electronic devices daily.

Neurons enhance blood–brain barrier function via upregulating claudin-5 and VE-cadherin expression due to glial cell line-derived neurotrophic factor secretion

Blood–brain barrier (BBB) prevents neurotoxins from entering central nervous system. We aimed to establish and characterize an in vitro triple co-culture BBB model consisting of brain endothelial cells hCMEC/D3, astrocytoma U251 cells, and neuroblastoma SH-SY5Y cells. Co-culture of SH-SY5Y and U251 cells markedly enhanced claudin-5 and VE-cadherin expression in hCMEC/D3 cells, accompanied by increased transendothelial electrical resistance and decreased permeability. Conditioned medium (CM) from SH-SY5Y cells (S-CM), U251 cells (U-CM), and co-culture of SH-SY5Y and U251 cells (US-CM) also promoted claudin-5 and VE-cadherin expression. Glial cell line-derived neurotrophic factor (GDNF) levels in S-CM and US-CM were significantly higher than CMs from hCMEC/D3 and U-CM. Both GDNF and US-CM upregulated claudin-5 and VE-cadherin expression, which were attenuated by anti-GDNF antibody and GDNF signaling inhibitors. GDNF increased claudin-5 expression via the PI3K/AKT/FOXO1 and MAPK/ERK pathways. Meanwhile, GDNF promoted VE-cadherin expression by activating PI3K/AKT/ETS1 and MAPK/ERK/ETS1 signaling. The roles of GDNF in BBB integrity were validated using brain-specific Gdnf silencing mice. The developed triple co-culture BBB model was successfully applied to predict BBB permeability. In conclusion, neurons enhance BBB integrity by upregulating claudin-5 and VE-cadherin expression through GDNF secretion and established triple co-culture BBB model may be used to predict drugs’ BBB permeability.

Influence of irradiation wavelength during laser-assisted doping of 4H-silicon carbide in liquid phase

Laser-assisted doping of silicon carbide (SiC) substrates is challenging due to the low diffusion coefficient of dopant atoms and the chemically inert nature of SiC. Single crystal intrinsic 4H-SiC substrate is irradiated with neodymium-doped yttrium aluminium garnet (Nd3+):YAG laser with wavelengths of 1064, 355 and 266 nm, and krypton fluoride (KrF) excimer laser with the wavelength of 248 nm under liquid phase dopant sources. Different liquid solutions were used as dopant sources for aluminium (Al) and phosphorus (P). SiC was transparent to 1064 and 355 nm due to low absorption coefficients, while 266 and 248 nm showed better coupling due to higher absorption coefficients and led to the diffusion of atoms. The electrical resistance of the substrates was measured to be lower than 1000 kΩ after diffusion. Dispersive X-ray spectroscopy (EDS) studies showed that both laser wavelengths of 248 nm and 266 nm resulted in doping of Al and P, with the surface concentrations ranging from 0.5 to 1.5 at.% and from 0.24 to 0.6 at.%, respectively. Two-dimensional thermo-temporal simulation of the laser pulse interaction in the liquid phase revealed that unlike in air, during irradiation with 266 nm laser under liquid, the surface temperature of the substrate was slightly lower. However, the subsurface temperature increased along the depth by a few microns. Similarly, simulation studies with longer pulse irradiation also show that high temperature was maintained for a longer time, indicating improved dopant diffusion into the 4H-SiC substrate.

Medulla Tetrapanacis water extract ameliorates mastitis by suppressing bacterial internalization and inflammation via MAPKs signaling in vitro and in vivo

AbstractMedulla Tetrapanacis (MT) is a commonly used herbal ingredient in soup to promote lactation and management of mastitis among lactating mothers worldwide, particularly in Asian countries. However, scientific evidence to support its usage in the management of mastitis is limited. This study aimed to investigate the effects of MT water extract and its underlying mechanisms in Staphylococcus aureus (SA)–induced mastitis in human mammary epithelial cells (HuMEC) and lipopolysaccharide (LPS)–induced mastitis in lactating Sprague–Dawley (SD) rats. The anti‐inflammatory and antibacterial effects of MT water extract were examined in SA‐infected HuMEC by ELISA and plate counting, respectively. The effects of MT water extract on blood‐milk barrier and the underlying mechanism of action of the MT water extract were also investigated by transendothelial electrical resistance assay and western blot. The effects and mechanisms of MT water extract on alleviating mastitis on SD rats were evaluated using LPS‐induced mastitis rat model. Our results showed that MT water extract could suppress SA‐induced mastitis by reducing SA internalization and growth, protecting blood‐milk barrier integrity, and attenuating release of cytokines (interleukin 6 [IL‐6] and tumor necrosis factor‐alpha [TNF‐α]) in HuEMC. Furthermore, the antibacterial effect might be related to the increase of antimicrobial peptides transcription, and the anti‐inflammatory effect is at least partly mediated by inactivation of p38 and JNK signaling pathways. Finally, our in vivo results showed that MT water extract ameliorated LPS‐induced mastitis in SD rats via suppressing inflammatory cytokine release (TNF‐α, IL‐6, and interleukin‐1 beta), myeloperoxidase, and alleviating pathohistological damage by downregulation of JNK signaling pathway.

Neurons enhance blood-brain barrier function via upregulating claudin-5 and VE-cadherin expression due to glial cell line-derived neurotrophic factor secretion.

Blood-brain barrier (BBB) prevents neurotoxins from entering central nervous system. We aimed to establish and characterize an in vitro triple co-culture BBB model consisting of brain endothelial cells hCMEC/D3, astrocytoma U251 cells, and neuroblastoma SH-SY5Y cells. Co-culture of SH-SY5Y and U251 cells markedly enhanced claudin-5 and VE-cadherin expression in hCMEC/D3 cells, accompanied by increased transendothelial electrical resistance and decreased permeability. Conditioned medium (CM) from SH-SY5Y cells (S-CM), U251 cells (U-CM), and co-culture of SH-SY5Y and U251 cells (US-CM) also promoted claudin-5 and VE-cadherin expression. Glial cell line-derived neurotrophic factor (GDNF) levels in S-CM and US-CM were significantly higher than CMs from hCMEC/D3 and U-CM. Both GDNF and US-CM upregulated claudin-5 and VE-cadherin expression, which were attenuated by anti-GDNF antibody and GDNF signaling inhibitors. GDNF increased claudin-5 expression via the PI3K/AKT/FOXO1 and MAPK/ERK pathways. Meanwhile, GDNF promoted VE-cadherin expression by activating PI3K/AKT/ETS1 and MAPK/ERK/ETS1 signaling. The roles of GDNF in BBB integrity were validated using brain-specific Gdnf silencing mice. The developed triple co-culture BBB model was successfully applied to predict BBB permeability. In conclusion, neurons enhance BBB integrity by upregulating claudin-5 and VE-cadherin expression through GDNF secretion and established triple co-culture BBB model may be used to predict drugs' BBB permeability.

Impact of valley degeneracy on the thermoelectric properties of zig-zag graphene nanoribbons with staggered sublattice potentials and transverse electric fields.

This study investigates the band inversion of flat bands in zig-zag graphene nanoribbons (ZGNRs) using a tight-binding model. The band inversion results from symmetry breaking in the transverse direction, achievable through deposition on specific substrates such as separated silicon carbide or hexagonal boron nitride sheets. Upon band inversion, ZGNRs exhibit electronic structures characterized by valley degeneracy and band gap properties, which can be modulated by transverse electric fields. To explore the impact of this level degeneracy on thermoelectric properties, we employ Green's function techniques to calculate thermoelectric quantities in ZGNR segments with staggered sublattice potentials and transverse electric fields. Two carrier transport scenarios are considered: the chemical potential is positioned above and below the highest occupied molecular orbital. We analyze thermionic-assisted transport (TAT) and direct ballistic transport (DBT). Level degeneracy enhances the electric power factors of ZGNRs by increasing electrical conductance, while the Seebeck coefficient remains robust in the TAT scenario. Conversely, in DBT, the enhancement of the power factor primarily stems from improvements in the Seebeck coefficient at elevated temperatures.

Research on mechanism of controlling water and stabilizing production in heavy oil reservoirs with edge-bottom water

The development of edge-bottom water heavy oil reservoirs typically involves short water-free production period and a rapid increase in water cut, leading to generally low oil recovery factors. Combining the advantages of foam and viscosity reducers for composite development can effectively address the challenges in edge-bottom water reservoirs; however, the mechanism of action remains unclear. In this study, the concentrations of foaming agent and viscosity reducer were initially determined using a foam evaluator and an Anton Paar rheometer. Subsequently, a 2D large flat plate model was employed to conduct a composite group production experiment after water flooding, and then the change in oil saturation during flooding was analyzed by measuring electrical resistance. Finally, the dynamic curves of flooding were compared to analyze the mechanism of water control and oil stabilization (WCOS). The results indicate that the 2D large flat plate model and the method of inverting saturation field maps can effectively simulate the oil-water flow behavior during the composite flooding process after water flooding. The synergistic mechanism of N2 foam controlling bottom water coning and CO2 enhanced viscosity reducer to reduce viscosity in deep areas was revealed, increasing the overall recovery factor by 10.3% compared to water flooding. The mechanism of the combined oil recovery is clarified, which providing a reference for formulating WCOS plans following water flooding.

A Flexible Organomagnetic Single-Layer Composite Film with Built-In Multistimuli Responsivity.

Materials possessing multiple properties and functionalities, that can be controlled or modulated by external stimuli, are a central focus of current research in materials sciences due to their potential to significantly enhance various future technological applications. Herein, we report a significant advancement in this field through the development of a smart, multifunctional organomagnetic composite material. By utilizing a thin layer of polydimethylsiloxane (PDMS) and polypyrrole (PPy) precursors, doped with nickel nanoparticles (NiNPs), we have created an innovative organomagnetic, PDMS/PPy/NiNPs (PPN), single-layer composite film that displays multistimuli responsivity. The study presents the first demonstration of a multifunctional flexible, three-component film structure integrating the structural and flexible PDMS component, together with a conductive polymer component and metal-based nanoparticles into a single-layer design, which displays enhanced and unprecedented responsivity properties against multiple different stimuli. Unlike typical stacked multilayered structures, that exhibit one or two functionalities at most, this novel configuration exhibits multiple functionalities, including magnetoresistance, mechanical stress response, piezoresistivity, and temperature change sensitivity. The as-prepared film demonstrates notable magnetoresistance responsivity, with a relative electrical resistance, ΔR/R0, changing under a weak magnetic field and under ambient conditions. The significance of our study lies in the film's versatility, stability, and sensitivity, especially within the physiological temperature range, making it highly relevant for future biomedical applications. Furthemore, the film's sensitivity to mechanical deformation reveals an impressive piezoresistance behavior. Unlike existing multilayer architectures of higher complexity, our single-layer thin film offers a simpler, more flexible, and reliable solution with a broad range of stimuli-sensing capabilities. The significance of this novel multiresponsive composite material is underscored by the growing demand for advanced materials in biomedical devices, magnetic switches, sensors, electronic skin, transistors, and organic spintronic devices. These promising organomagnetic self-standing layers provide a robust platform for future technological innovations.

Reply to “Evidence of Superconductivity in Electrical Resistance Measurements of Hydrides Under High Pressure” by Balakirev et al.

Reply to “Evidence of Superconductivity in Electrical Resistance Measurements of Hydrides Under High Pressure” by Balakirev et al.