Search

Zinc Oxide (ZnO) exhibits a significant Seebeck coefficient, making it a promising candidate for thermoelectric energy harvesting. This study explores composite materials comprising xW 18 O 49 /(1-x)ZnO fabricated through conventional sintering at 1150°C, with x varying from 0 to 0.3. Incorporating a highly conductive secondary phase into the ZnO matrix enhances conductivity by 28 times, reaching 111.4 Scm−1 at 800°C, while maintaining 83 % of the pristine sample's Seebeck coefficient. Notably, the power factor improves to 3.8 mWK−2m−1 for the x = 0.1 sample, representing a 19 times heightening over unmodified ZnO ceramic. Additionally, these composites exhibit high weight mobility, indicating rapid electronic responses. As a result, the ZT value increases by 500 %, reaching 0.15 at 800°C for the x = 1 sample. This study presents a novel approach to fabricating high-power-factor thermoelectric materials by integrating highly conductive oxides into matrices with large Seebeck coefficients. [Display omitted] • A composite xW 18 O 49 /(1-x)ZnO materials with variable x being 0.05, 0.1, 0.15, 0.2, 0.25 and 0.3, respectively. • Multi-scale defects are induced in a composite xW 18 O 49 /(1-x)ZnO materials. • A conductive W 18 O 49 oxide phase enhanced remarkably thermopower factor of ZnO composites. • Multi-scale defects controlled thermoelectric performances are addressed in terms of weighted mobility μ W. [ABSTRACT FROM AUTHOR]

This study was focused on unraveling the close dependence of the structural, morphological, and thermoelectric properties of sputtered ZnO films on base pressure. The ZnO film deposited at an optimized base pressure of 5 × 10−6 torr exhibited the highest thermoelectric power factor of 374.6 μW/mK2, corresponding to an electrical conductivity of 265 S/cm and a Seebeck coefficient of −124 μV/K at 583 K. The obtained results revealed that the positive effect of base pressure on enhancing thermoelectric properties of ZnO films is attributed to point-defect modification, including zinc vacancies, singly-, and doubly-charged oxygen vacancies. Based on these results, we propose that defect engineering is a facile and effective approach for improving the thermoelectric behavior of ZnO films, even without doping by controlling the sputtering conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

In this work, spherical-like ZnO nanoparticles (NPs) were synthesized via avocado seed extract and calcined at 400 °C, which exhibited a hexagonal wurtzite structure with an average size of around 42 nm. The chemical states, organic residuals, and defects were confirmed by X-ray photoelectron spectroscopy (XPS). The ZnO NPs-based memristors exhibited remarkably stable analog switching, over 300 continuous cycles, and a wide operating window of 400. Moreover, the asymmetry in the current observed was attributed to the self-rectifying nature of this device, comprising one analog memristor and one Schottky diode (1D–1R). By controlling the peak voltage to 4 V and applying 50 bias pulses, it was possible to effectively imitate the key features of synaptic behavior, including potentiation and depression, through current modulation. [Display omitted] • The Cr/ZnO/FTO memristors based on green synthesized ZnO NPs demonstrate stable analog resistive switching over 300 operating cycles and a 400-ON/OFF ratio window. • The self-rectifying property of the memristor originates from the Schottky diode at the Cr/ZnO junction. • The synaptic behavior showcases non-volatile properties and emulates synapse-like characteristics. [ABSTRACT FROM AUTHOR]

Using laser flash analysis, the low thermal conductivity of the pressed Zirconium metal-organic framework (UiO-66) powder pellet was obtained. As a result, the density ρ, thermal diffusivity α, specific heat capacity cP, and low thermal conductivity κexp of the pressed UiO-66 powder pellet at 300 K are observed to be 1.258 g/cm3, 0.001 59 cm2/s, 0.7765 J/g K, and 0.156 W/m K, respectively. Due to the presence of the 12-coordinated nodes with six transfer pathways, the thermal transport of the UiO-66 particles is preferred through linkers to metal sites. The low thermal conductivity follows the trend of vacuum < argon (Ar) < air < helium (He) since the entrapped gas molecules provide additional heat transfer channels inside the particles and between the particles. The low thermal conductivity along with a weak temperature-dependent thermal conductivity are elucidated in terms of boundary scattering. [ABSTRACT FROM AUTHOR]

A critical stage in developing high-density memristors is addressing the sneak current within the crossbar architecture. One of the effective strategies to endow the memristive cell with the ability to prevent sneak currents when it is in a low resistance state is to give it an inherent diode, known as a self-rectifying memristive cell. This study demonstrates the Schottky diode inside the MAPbI3-based memristive cell, a consequence of its interaction with the tungsten (W) electrode. The performance of memory devices is reliable with low-voltage operation, a resistance window having over ten of magnitude, and the retention time remains over 104 s. Prominently, the self-rectifying behavior is sustainable over 150 cycles and exhibits a rectification ratio of approximately 102 times. Density functional theory calculation reveals the presence of unoccupied gap states on an interfaced MAPbI3 surface, serving as electron trapping states during the charge transport across the W/MAPbI3 Schottky interface. Consequently, the conduction mechanism is primarily governed by an interfacial-controlled model, notably Schottky emission. This improvement promises to eliminate sneak currents in future crossbar array fabrication. [ABSTRACT FROM AUTHOR]

Developing highly efficient and durable hydrogen evolution reaction (HER) electrocatalysts is crucial for addressing the energy and environmental challenges. Among the 2D-layered chalcogenides, MoSe2 possesses superior features for HER catalysis. The van der Waals attractions and high surface energy, however, stack the MoSe2 layers, resulting in a loss of edge active catalytic sites. In addition, MoSe2 suffers from low intrinsic conductivity and weak electrical contact with active sites. To overcome the issues, this work presents a novel approach, wherein the in situ incorporated diethylene glycol solvent into the interlayers of MoSe2 during synthesis when treated thermally in an inert atmosphere at 600 °C transformed into graphene (Gr). This widened the interlayer spacing of MoSe2, thereby exposing more HER active edge sites with high conductivity offered by the incorporated Gr. The resulting MoSe2-Gr composite exhibited a significantly enhanced HER catalytic activity compared to the pristine MoSe2 in an acidic medium and demonstrated a superior HER catalytic activity compared to the state-of-the-art Pt/C catalyst, particularly at a high current density beyond ca. 55 mA cm−2. Additionally, the MoSe2-Gr catalyst demonstrated long-term electrochemical stability during HER. This work, thus, presents a facile and novel approach for obtaining an efficient MoSe2 electrocatalyst applicable in green hydrogen production. [ABSTRACT FROM AUTHOR]

Using Camellia Sinensis leaf aqueous extract as a friendly reducing, capping, and stabilizing agent, ZnO nanoparticles (NPs) are synthesized via the green process. The plausible mechanism for the ZnO NPs formation is proposed as the chelation of Zn, or metal complexation, under the thermally assisted energy from the annealing process. An inclusive study on the effect of the annealing process on the ZnO NPs is conducted from room temperature to 850 °C. The structural, morphological, thermal, and optical characteristics and their intercorrelation with annealing temperature are thoroughly studied. In particular, the change of crystalline texture coefficient contributed to the systematic perspective of the shape changes of the ZnO NPs. The (002)-oriented growth becomes preferred at 400–700 °C, corresponding to the increase of conical-shaped NPs from 150 to 250 nm in average size. With further temperature, the preferred growth transfers from (002) to (100) orientations, and polygonal spherical-shaped NPs can be obtained. Photoluminescence spectra reveal that singly and doubly ionized oxygen vacancies are the most dominant in the NPs. With the optimized green materials, implementing an eco-friendly memristor based on ZnO NPs found promising for electronic devices. The green synthesis of ZnO NPs using Camellia Sinensis leaf extract. [Display omitted] [ABSTRACT FROM AUTHOR]

A series of porphyrinic-Al-based metal–organic framework (MOF) nanomaterials were successfully fabricated via a simple solvothermal procedure and denoted as AlPMOF(M) (M = Cu, Co). The materials exhibited high surface areas with rectangular morphologies and the desired phases. Chemical composition studies demonstrated the presence of Cu and Co ions in the synthesized samples, while thermal studies showed the samples were stable up to 400 °C. CO gas-sensing studies revealed better CO sensing performances of both the AlPMOF(Cu) and AlPMOF(Co) gas sensors compared to the pristine sensor at room temperature. AlPMOF sensor showed responses of 1.06 and 1.05–10 ppm CO gas at 150 and 25ºC, respectively, with no selectivity to CO gas at 25ºC. AlPMOF (Co) sensor revealed responses of 1.11 and 1.06–10 ppm CO gas at 200 and 25ºC, respectively, with selectivity to CO gas at 25ºC. Also, AlPMOF (Cu) sensor revealed responses of 1.12 and 1.07–10 ppm CO gas at 150 and 25ºC, respectively, with selectivity to CO gas at 25ºC. In addition, the sensing mechanism and enhanced response to CO gas were elucidated. These findings demonstrate the capability of these novel sensing materials for CO gas sensing at low temperatures. [Display omitted] • Porphyrinic pristine and Co2+ and Cu2+metalated Al-based MOFs were synthesized. • Structural, compositional, and morphological studies were fully performed on the synthesized MOFs. • The metalated MOF sensors showed enhanced CO gas sensing performance. • The sensing mechanism of the sensors were fully explained. [ABSTRACT FROM AUTHOR]

The memory device is based on a nanocomposite of cellulose fibers and ZnO nanoparticles. [Display omitted] • The environmentally friendly nanocomposites from lotus fiber cellulose and nano-ZnO. • The volatile behavior-based cellulose turned to the nonvolatile-based ZnO@cellulose. • The oxygen vacancies of nano-ZnO are responsible for the resistive switching mechanism. • The sustainable approach for the high potential of bio-organic electronic devices. Electronic devices incorporating green materials offer a sustainable and environmentally friendly alternative, harnessing the unique properties of natural substances to contribute to a more eco-conscious and biodegradable technological landscape. This study extracts cellulose fibers from lotus petiole and decorates them with zinc oxide (ZnO) nanoparticles. The hybrid ZnO and cellulose (ZC) nanocomposite was used as a switching layer in the RRAM structure. The ZC thin film-based device displayed non-volatile bipolar behavior, whereas the device based on pure cellulose exhibited volatile behavior. This ZC-based device had significant enhancements, including a low operating voltage range of 2.0 V, a high ON/OFF resistance ratio of 103, endurance of 102 cycles, and an excellent retention time of 104 s. Oxygen vacancies, explored by PL and XPS results, are the most dominant in ZnO particles, indicating a substantial effect on the non-volatile characteristic in the Ag/ZC/FTO device. These results demonstrate that the lotus petiole cellulose-ZnO nanocomposite is a promising material for developing eco-friendly and low-cost memory devices. [ABSTRACT FROM AUTHOR]

Designing surface-enhanced Raman scattering (SERS) substrates that combine multiple advanced features in synergy is highly desirable for the SERS technique, however, it has been a long-standing challenge due to inherent trade-offs in feature selection. For instance, while nanoplasmonic surface functionalization bolsters attraction to target analytes, it simultaneously introduces barriers to direct contact. Similarly, the intrinsic hydrophilic or hydrophobic nature of substrates often limits their sensing effectiveness across a wide range of analyte types. Here, we demonstrate a smart 3D Ag-decorated TiO 2 nanostructure, an advanced synergistic SERS substrate, created by controlling the formation of Ag nanoparticles on functionalized TiO 2 nanomaterials, which integrates four unique features: uniform hotspot distribution, efficient analyte trapping, accessible plasmonic surfaces, and dual-phase detection. This design brings unachieved sensor efficiency across a diverse array of analytes with varying sizes and hydrophobicity. Moreover, our design exhibits a novel dual-phase detection capability within mixtures of hydrophilic and hydrophobic analytes. As a proof-of-concept, our results highlight the potential of designing SERS substrates with multiple advanced features that work synergistically, enabling trace detection of a broader range of analyte types in various environments. More broadly, we anticipate that this work paves the way for the development of other nanomaterials that are capable of attracting diverse molecules while retaining key features such as accessible plasmonic surfaces and wide-area ordered hotspot distribution. Such nanomaterials could be powerful for advanced applications in hotspot engineering, surface analysis, catalysis, and plasmon-mediated reactions. [Display omitted] • Smart 3D Ag-decorated TiO 2 nanostructure, an advanced synergistic SERS substrate, has been successfully fabricated. • Integrating multiple unique features, this structure overcomes inherent trade-offs in feature selection during fabrication. • This substrate demonstrates exceptional detection efficiency for diverse analytes with varying natural properties. • The SERS substrate exhibits a novel dual-phase detection capability within mixtures of hydrophilic and hydrophobic analytes. [ABSTRACT FROM AUTHOR]

Transparent-flexible thermoelectric materials are attractive for future small-sized consumer electronics, the internet of things, and wearable devices. The microstructural evolution and subsequent thermoelectric properties of Ti 1%.at-doped ZnO thin films, grown on polyimide flexible substrates, are presented. The thin films were grown using radio frequency a magnetron sputtering method followed by annealing for 60 min at temperatures of 200–400 °C under vacuum atmosphere. Post-annealed films demonstrate a hexagonal Wurtize structure. It is found that the annealing helped to relax residual stresses in the thin films, subsequently leading to enhanced charge concentration, carrier mobility, mean free path, and density-of-states effective mass. The thin film, annealed at 300 °C, illustrates the highest power factor of the films measured at room temperature at 19.10 μW m−1 K−2. Further increases in the annealing temperature suggest Ti2+ diffuses into the ZnO lattice and in turn disturbs the crystalline structure; this results in a reduction of the power factor to 9.32 μW m−1 K−2 at an annealing temperature of 350 °C. [ABSTRACT FROM AUTHOR]

The antimicrobial properties of 8-Hydroxyquinoline (8-Hq), a small organic compound known for its metal-chelating capabilities, hold significant promise. However, its limited solubility in water poses a challenge for practical applications. In this study, we address this limitation by augmenting the antimicrobial efficacy of 8-Hq through its integration into the metal-organic framework UiO-66 (named 8-Hq@UiO-66) and coupling it with iron ions (designated as Fe/8-Hq@UiO-66) via an adsorption process. The sorption isotherm and adsorption kinetics were meticulously examined using Langmuir's adsorption model and the pseudo-second-order kinetic model. Material characterization techniques including powder X-ray powder diffraction, Fourier transform infrared spectroscopy, thermogravimetric analysis, nitrogen adsorption isotherms, ultraviolet–visible spectroscopy, and photoluminescence spectroscopy revealed the coordination of zirconium clusters and iron with the nitrogen and hydroxyl groups of 8-Hq, respectively. Furthermore, our investigation into metal ion adsorption demonstrated that the 8-Hq@UiO-66 composite displayed a notable selectivity for iron ions over other metal ions in aqueous media. Under optimized conditions, the adsorption capacity for iron ions ranged from approximately 34–46 mg g−1. Importantly, the Fe/8-Hq@UiO-66 composite exhibited potent antimicrobial activity against Bacillus subtilis , Staphylococcus aureus , and Escherichia coli. These findings underscore the potential of incorporating 8-Hq into porous metal-organic frameworks and coupling it with iron ions to enhance its antimicrobial efficacy. [Display omitted] • Enhanced antimicrobial efficacy via 8-Hq and iron ion integration into UiO-66. • Insights from sorption isotherms and kinetics models. • Selective conjugation of iron ions by 8-Hq@UiO-66. • Potent antimicrobial activity against diverse bacterial strains demonstrated. [ABSTRACT FROM AUTHOR]

The electrocatalytic activity of Mn x O y materials derived from the metal-organic framework (Mn-BTC) was investigated in dry (for lithium-ion batteries (LIBs)) and wet (for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER)) conditions while observing the phase transformation from annealing Mn-BTC in the air. As a result, the partial α-MnO 2 , Mn 3 O 4 , and Mn 2 O 3 phases were formed at 300, 500, and 700 °C, respectively. The electrocatalytic activity of Mn x O y materials follows the order (Mn 3 O 4 > Mn 2 O 3 > α-MnO 2 > Mn-BTC) in both dry and wet conditions. For instance, Mn 3 O 4 electrodes delivered an initial discharge/charge capacity of 1302/815 mAh g−1 with an initial Coulombic efficiency of 62.6% when used as anodes for LIBs. They also exhibited a lower Tafel slope of 116 and 54 mV dec−1 when applied to HER and OER, respectively. The structural analysis showed that the best electrocatalytic activity of Mn 3 O 4 samples originated from the spinel Mn 3 O 4 structure with Mn2/Mn3+ ions occupying the tetrahedral and octahedral sites, high electrical conductivity and small grain size. This study provides insights into the role of physicochemical properties in controlling Mn x O y phases from Mn-BTC materials via the annealing process towards applications as potential electrode materials for LIBs, HER, and OER. [Display omitted] • The electrocatalytic activity of Mn x O y -derived Mn-BTC for LIBs and HER/OER. • α-MnO 2 , Mn 3 O 4 , Mn 2 O 3 phases were formed at 300, 500, 700oC-annealed Mn-BTC. • The electrocatalytic activity follows Mn 3 O 4 > Mn 2 O 3 > α-MnO 2 > Mn-BTC. • The electrocatalytic activity depends on the spinel Mn 3 O 4 structure. [ABSTRACT FROM AUTHOR]

In this work, role of phase composition and interstitial oxygen on the thermoelectric properties of CuCr 0.85 Mg 0.15 O 2 materials prepared at different sintering temperatures (1273–1673 K) for short time (3 h) are reported. Interestingly, the samples sintered at 1273 K and 1673 K had the same Seebeck coefficient, despite the 1273 K sample having significantly lower conductivity, which are discussed via phase composition and interstitial oxygen induced during the CuCrO 2 phase formation and its related defect (V Cu , V Cr , ...). Besides, high conductivity of the 1673 K sample originated from the low percentage of CuO phase and the appearance of Cu 2 O phase. Since the 1273 K and 1673 K sintered samples have almost the same percentage of delafossite and spinel phases so the 1673 K sample still remain its high Seebeck coefficient. We suggest some reaction chemical equations for elucidating the roles of interstitial oxygen on the phase composition and thermoelectric properties CuCr 0.85 Mg 0.15 O 2 delafossite material. [Display omitted] • Phase composition and interstitial oxygen control thermoelectric properties of CuCr 0.85 Mg 0.15 O 2. • Native interstitial oxygen is induced during the CuCrO 2 phase formation. • Samples sintered at 1273 and 1673 K have the same Seebeck coefficient but different conductivity. • High conductivity of the 1673 K sample originated from the low percentage of CuO phase and the appearance of Cu 2 O phase. • Seebeck coefficient of samples depends on component phases but its behavior follow Heikes or Pysarenko law by defect-type. [ABSTRACT FROM AUTHOR]

CuAgSe is a promising thermoelectric material whose p-type and n-type thermoelectric figure of merit, Z T , values are relatively high (0.95 and 0.70, respectively). It exhibits native n-type conduction, while p-type conduction is present in non-stoichiometric CuAgSe. Here, we report that the carrier type in CuAgSe semiconductors can be effectively controlled by changing the growth process or doping. We were able to switch the carrier type of CuAgSe from the native n-type to the non-stoichiometric p-type by increasing the soaking time during growth. In contrast, the n-type conduction was always observed when Ni, Co, and Zn were doped into the host lattices. We obtained a maximum Z T value of 0.69 at 623 K in undoped n-type CuAgSe. Zn is a promising dopant for n-type CuAgSe with a Z T value of 0.68 at 623 K, which can be further optimized. Our work provided a simple and effective technique for producing both single-phase n- and p-type CuAgSe. • We have grown single-phase undoped and Ni-, Co-, and Zn-doped polycrystalline CuAgSe using the 'growth from the melt' method • We have controlled the carrier type of CuAgSe by simply changing soaking time during growth or by Ni-, Co-, and Zn-doping. • We have found that Zn is a promising dopant for n-type CuAgSe, providing enhanced Z T values. [ABSTRACT FROM AUTHOR]

In this study, copper selenide (Cu 2 Se) compounds were synthesized using a solid-state reaction technique and post-sintering processes (573 ​K–973 ​K). The mass density of the Cu 2 Se compounds decreased with increasing sintering temperatures due to changes in grain morphology and an increase in the number and size of pores in the samples. The sintering temperature also affected carrier generation mechanisms, which directly impacted the electrical transport characteristics and thermal properties. The α→β phase transition at around 400 ​K was observed in all samples. The low thermal conductivity was mainly attributed to the low lattice thermal conductivity (κ lattice). As the result, the sample sintered at 773 ​K showed an outstanding ZT value of 1.44 ​at 773 ​K, with a power factor of 12.1 μWm−1K−2 and the thermal conductivity of 0.65 Wm−1K−1. The sintering temperature dependence of thermal conductivity was elucidated in terms of the growth of microstructural pores. Copper selenide (Cu2Se) compounds synthesized using the solid-state reaction technique and post-sintering processes have achieved outstanding ZT values of up to 1.44 ​at 773 ​K. [Display omitted] • Successful synthesis of Cu2Se compounds using solid-state reaction and sintering processes. • Mass density decreased with increasing sintering temperature due to changes in grain morphology and pore size. • Carrier generation mechanisms played a crucial role in determining electrical and thermal transport characteristics. • Sintered samples at 773 ​K showed exceptional thermoelectric performance with a ZT value of 1.44. • Thermal conductivity depended on sintering temperature and was correlated with the growth of microstructural pores. [ABSTRACT FROM AUTHOR]

In-paper flexible SERS chips were simply prepared by immersing pieces of filter paper into colloidal silver nanoparticle (e-AgNP) solution for 24 h and drying naturally at room temperature. Characteristic properties of cellulose fibers allowed the paper-based chips to be available for two sample collecting approaches. Being hydrophilic but insoluble in water, the chips were convenient to be dipped into aqueous media to collect soluble target analytes. Besides, they could "stick" on wet surfaces and bend along them to grab analytes. Hence, they were employed for in-situ detection of methylene blue dye in river water using "dip and dry" method and thiram pesticide on apple skin using "paste and peel off" procedure, resulting in detection limit of 10−10 M with excellent recovery rates of 93–104% and 86–93%, respectively. Therefore, the e-AgNPs-based in-paper SERS chips have served as a versatile tool for a large range of samples. More importantly, simple procedures of SERS chip preparation and sample collecting do not require the use of any complex equipment or expert operators. It can bring SERS techniques a step closer to real applications. [Display omitted] • In-paper flexible SERS chips were simply fabricated by immersing pieces of filter paper into electrochemically-synthesized silver nanoparticle (e-AgNPs) solution for 24 h and then being dried at room temperature. • The as-prepared SERS chips are convenient for two on-site sample collecting approaches: "dip and dry" method for liquid samples as well as "paste and peel off" method for surfaces. • In the "dip and dry" approach, the SERS chips could be employed to detect methylene blue in river water at concentrations as low as 1.0 × 10−10 M • In the "paste and peel off" approach, the SERS chips were effective to sense thiram on apple skin at concentrations down to 1.0 × 10−10 M (∼2.4 × 10−13 g/cm2). [ABSTRACT FROM AUTHOR]

ZnO/CuO nanocomposites were derived from a metal-organic framework (MOF) using a simple precipitation method. The mesoporous nature, crystallinity, and fine particle size of the synthesized ZnO/CuO nanocomposites varied with CuO amounts, affecting the gas sensing ability of different gases (H 2 S, CO, C 6 H 6 , and C 7 H 8 gases). It was found that the ZnO/CuO (40 mol%) gas sensor showed the highest sensing capacity in terms of response, selectivity, and repeatability on low concentrations of H 2 S gas (10 ppm). The strong sensing performance, short response time (58 s) and recovery time (273 s) were explained in terms of the texture coefficients (phase percentage, crystal size, and crystallinity) of the ZnO and CuO phase compositions, resulting in the formation of a high number of p-n junctions and quantum confinement effects in the nanocomposite, as well as the lower binding energy of H 2 S. The fast sensing ability of a low H 2 S concentration highlights the practical importance of these MOF-derived ZnO/CuO nanocomposites. • H 2 S sensors were made with MOF-derived ZnO/CuO (M-ZnO/CuO) nanocomposites. • M-ZnO/CuO nanocomposites with different compositions were synthesized at low temperature. • M-ZnO/CuO nanocomposites with 40 mol% CuO showed the highest sensing performance to H 2 S gas. • M-ZnO/CuO nanocomposites with 40 mol% CuO selectivity detected to 10 ppm H 2 S gas. • Enhanced response and selectivity to H 2 S gas were explained. [ABSTRACT FROM AUTHOR]

• The FeOOH, γ-Fe 2 O 3 , and α-Fe 2 O 3 nanorods with numerous functional groups of OH were prepared by a simplistic method. • The effect of phase compositions of iron oxide nanorods on sensing properties was also discussed. • Mass-type sensor bases on γ-Fe 2 O 3 exposes the highest response to SO 2. • This study has opened up a new sighting of the iron oxide in a sensing application. α-FeOOH nanorods were synthesized by a facile precipitation method. γ-Fe 2 O 3 and α-Fe 2 O 3 nanorods were then obtained by calcining for 6 h at 200 and 600 °C in ambient air, respectively. A mass-type sensor was developed based on the different iron oxide phase compositions of α-FeOOH, γ-Fe 2 O 3 and α-Fe 2 O 3 coating a quartz crystal microbalance (QCM). The gas sensing properties of three as-prepared sensors were systematically examined for detecting sulphur dioxide gas (SO 2) at room temperature. The effect of phase composition of iron oxide nanorods on sensing properties was also discussed. Although as-prepared iron oxides have a similar morphologic structure, the sensor based on γ-Fe 2 O 3 exposes the highest response to SO 2. The sensing results show that the γ-Fe 2 O 3 coated QCM sensors had an extremely good performance for SO 2 gas in the 2.5–20 ppm range at room temperature. [ABSTRACT FROM AUTHOR]

We report on the effects of Se/Sn flux ratio to the growth and thermoelectric properties of SnSe thin films on MgO (100) substrate. All films were epitaxially grown at 300 °C with various Se/Sn flux ratios of 0.8, 0.9, 1, 3, 5, and 7. The crystal structure of the obtained SnSe thin films was orthorhombic (Pnma space group) with a- axis (h00) orientation. XRD Φ-scan studies showed an existence of orthorhombic domains, whose rotation can be modulated by the Se/Sn flux ratio. A structure consisting of 0° and 90° rotated domains was observed in all samples, while additional 45° rotated domains were simultaneously observed in the samples with higher Se/Sn ratio of 5 and 7. Especially, 135° rotated domains were observed in sample Se/Sn = 7. Interestingly, the best crystalline film was obtained at the Se/Sn = 1. We found that Seebeck coefficients were positive at room temperature, decreased with temperature and became negative for the sample Se/Sn = 1, indicating bipolar transport in the samples. A maximum PF value of 3.74 μWc m −1 K −2 was obtained at 550 K for sample Se/Sn = 0.8. • We have successfully grown SnSe epitaxial thin films on MgO (100) at 300 oC with various Se/Sn flux ratio. • The films exhibit orthorhombic domains, whose rotation can be effectively modulated by the Se/Sn flux ratio. • The highest crystallinity film is obtained at Se/Sn flux ratio of 1. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) is a powerful, highly efficient analytical technique capable of providing label-free, non-invasive, rapid, and ultrasensitive molecular detection down to the single-molecule level. Despite its advantages, SERS remains largely confined to laboratory settings due to the complexities of substrate fabrication and challenges in analyzing real-world samples. Developing flexible SERS substrates that achieve both high fabrication efficiency and high sensing performance, while being practical for field applications, is critical for advancing SERS toward broader, real-world use. In this study, we present a novel paper-based Ag dendritic SERS chip, fabricated via a simple chemical reduction process that directly forms Ag dendritic nanostructures on cellulose fibers. This chip substrate demonstrates exceptional sensitivity for the detection of thiram pesticide, with a detection limit as low as 7.76 × 10 -11 M. The chip substrate also exhibits outstanding reliability, with reproducibility and repeatability both less than 5%. Furthermore, the flexible nature of the paper substrate enables it to conform to curved surfaces and be in direct contact with analytes, exemplified by its ability to adhere to and retrieve thiram from pear skin using a novel "paste-and-peel-off" technique. The substrate shows remarkable performance for thiram detection on pear skin, with sharp recovery rates ranging from 90% to 105%. With its facile fabrication, excellent sensitivity, high reliability, and practical applicability in non-invasive sampling, the paper-based Ag dendritic SERS substrate offers significant potential as an advanced substrate to bring SERS out of the laboratory and closer to real-world applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

The calcium release activated calcium (CRAC) channel is highly expressed in T lymphocytes and plays a critical role in regulating T cell proliferation and functions including activation of the transcription factor nuclear factor of activated T cells (NFAT), cytokine production and cytotoxicity. The CRAC channel consists of the Orai pore subunit and STIM (stromal interacting molecule) endoplasmic reticulum calcium sensor. Loss of CRAC channel mediated calcium signaling has been identified as an underlying cause of severe combined immunodeficiency (SCID), leading to drastically weakened immunity against infections. Gain-of-function mutations in Orai and STIM have been associated with tubular aggregated myopathy (TAM), a skeletal muscle disease. While a number of small molecules have shown activity in inhibiting the CRAC signaling pathway, the usefulness of those tool compounds is limited by their off-target activity against TRPM4 and TRPM7 ion channels, high lipophilicity, and a lack of understanding of their mechanism of action. We report structure-activity relationship (SAR) studies that resulted in the characterization of compound 4k [1-(cyclopropylmethyl)-N-(3-fluoropyridin-4-yl)-1H-indazole-3-carboxamie] as a fast onset, reversible, and selective CRAC channel blocker. 4k fully blocked the CRAC current (IC 50 : 4.9 μM) and the nuclear translocation of NFAT at 30 and 10 μM, respectively, without affecting the electrophysiological function of TRPM4 and TRPM7 channels. Computational modeling appears to support its direction binding to Orai proteins that form the transmembrane CRACchannel., Competing Interests: Declaration of competing interest All authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Masson SAS. All rights reserved.)

In this work, ZnO nanoparticles (NPs) are synthesized using avocado seed extract and annealed at different annealing temperatures from 400 to 800 °C. The morphology of the nanoparticles changes from poly shapes at 400 °C to spherical ones at 800 °C, and particle sizes increase from ∼42 nm to ∼128 nm. The Ag/ZnO@400/FTO memory device exhibits stable resistive switching over 100 cycles and a resistance window of approximately 150. Also, the performance characteristics of ZnO@600 and ZnO@800-based devices are degraded gradually over operating cycles. The concentration of oxygen interstitials (O i ) in ZnO nanoparticles, which may originate from organic residues, decreases as the annealing temperature increases. These O i ions reduced the energy barrier at the interfaces, facilitating electron transport under an external electric field. This study has demonstrated the close correlation between resistive switching characteristics and organic residuals in green synthesized nanoparticles., Competing Interests: The authors have no conflicts to disclose. The XRD, FTIR, Raman, XPS and EDX data of the ZnO@400 sample were reprinted with permission from ref. 40., (This journal is © The Royal Society of Chemistry.)

A flexible, ultrasensitive, and practical SERS chip is presented based on a paper/f-TiO 2 /Ag structure. The chip enhances the self-assembly of Ag nanoparticles on a cellulose fiber matrix, facilitated by smart functionalized TiO 2 nanomaterials (f-TiO 2 ). This design enables superior detection of the hazardous pesticide tricyclazole (TCZ) on crops using an advanced, simple, and efficient analytical method. Despite its straightforward fabrication process via a solvent immersion method, the intrinsic smart surface properties of the TiO 2 bridging material - both hydrophilic and hydrophobic - enable the uniform and dense self-assembly of hydrophilic Ag nanoparticles (NPs) on the cellulose fiber paper substrate. This innovative design provides superior sensing efficiency for TCZ molecules with a detection limit reaching 2.1 × 10 -9  M, a remarkable improvement compared to Paper/Ag substrates lacking f-TiO 2 nanomaterials, which register at 10 -5  M. This flexible SERS substrate also exhibits very high reliability as indicated by its excellent reproducibility and repeatability with relative standard deviations (RSD) of only 5.93% and 4.73%, respectively. Characterized by flexibility and a water-attractive yet non-soluble surface, the flexible Paper/f-TiO 2 /Ag chips offer the convenience of direct immersion into the analytical sample, facilitating seamless target molecule collection while circumventing interference signals. Termed the "dip and dry" technique, its advantages in field analysis are indisputable, boasting in situ deployment, simplicity, and high efficiency, while minimizing interference signals to negligible levels. Through the application of this advanced technique, we have successfully detected TCZ in two high-value crops, ST25 rice and dragon fruit, achieving excellent recovery values ranging from 90 to 128%. This underscores its immense potential in ensuring food quality and safety. As a proof of concept, flexible Paper/f-TiO 2 /Ag SERS chips, with a simple fabrication process, advanced analytical technique, and superior sensing efficiency, bring SERS one step closer to field applications beyond the laboratory., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Introduction and Importance: Primary gastrointestinal stromal tumors of the liver are exceedingly rare entities, presenting diagnostic and therapeutic challenges. The authors present a case of a 64-year-old male with a primary gastrointestinal stromal tumor (GIST) of the liver, emphasizing the importance of comprehensive diagnostic evaluation and multidisciplinary management in such uncommon cases., Case Presentation: The patient presented with persistent hypochondriac pain, leading to the discovery of a hepatic mass. Diagnostic work-ups, including imaging studies and biopsy, confirmed the diagnosis of primary GIST in the liver. Following thorough multidisciplinary consultation, the patient underwent right anterior segmentectomy of the liver, performed by our experienced surgeon. Postoperative pathology confirmed the diagnosis of GIST, and the patient was advised to use adjuvant imatinib., Clinical Discussion: Primary GISTs of the liver pose diagnostic challenges due to their rarity and varied clinical presentations. Imaging modalities, immunohistochemistry, and molecular genotyping are crucial in accurate diagnosis and treatment planning. Surgical resection remains the cornerstone of treatment for localized GISTs, with adjuvant therapy considered based on recurrence risk factors and molecular characteristics., Conclusion: This case highlights the need for multidisciplinary consultation in managing primary GISTs of the liver. Accurate diagnosis, surgical expertise, and personalized adjuvant therapy are crucial for better patient outcomes. Further research is necessary to enhance our understanding of prognostic factors and treatment strategies for these rare tumors., Competing Interests: The author declares no conflicts of interest.Sponsorships or competing interests that may be relevant to content are disclosed at the end of this article., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Google Classroom is a virtual education platform created by Google that allows both instructors and learners to actively participate in educational environments inside and outside of the classroom in an innovative way. This research aims to determine how university students perceived the adoption of Google Classroom in writing classes. This research was a convergent parallel mix-methods approach in which data were gathered through a 5-point Likert scale questionnaire and semi-structured interviews. The participants of this study included 130 university students in Vietnam. The results revealed that students expressed their approval of using Google Classroom in writing classes and that they had a positive view since it benefited them greatly in their learning writing process. This study suggests practical implications for language educators to use Google Classroom in writing classes., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Aim: Sleep disorders are common in cancer patients and have negative consequences for patient well-being and treatment outcomes. This study aimed to investigate sleep quality and related factors in Vietnamese middle-aged cancer patients., Methods: A cross-sectional study was conducted on 246 middle-aged in-patient cancer patients at Vietnam National Cancer Hospital (VNCH) from 1/2021 to 7/2021. Sleep was measured by the Pittsburgh Sleep Quality Index (PSQI), with a cutoff of 5., Results: The results showed a male/female ratio of 0.85 with an average age of 52. The five most prevalent cancer types were breast, colorectal, lung, and esophagus-stomach cancer, primarily in the late stage and treated with chemotherapy. The prevalence of sleep disturbances was 58.5%. The mean PSQI score was 7.5, with sleep duration and latency of 5.4 h and 1 h, respectively. Approximately 44% of participants reported poor sleep quality, nearly 9% had daytime dysfunction, and 10.6% used sleep medication. The multivariate logistic regression results indicate that people with depression were 8.89 times more likely to have poor sleep than those without depression (95% CI:2.63-28.27, p < .001)., Conclusion: Sleep problems are common among middle-aged people with cancer in Vietnam, especially individuals with depression. It is necessary to have more effective approaches to sleep management for cancer patients with limited resources., (© 2024 The Authors. Cancer Reports published by Wiley Periodicals LLC.)

Fintech development is generally considered as an effective mechanism to promote the consumption of renewable energy sources. The relationship between fintech development and renewable energy consumption have been examined in previous studies. However, the moderating effect of income inequality on this relationship has largely been ignored in the existing literature. As such, this study is conducted to shed light on this moderating effect. Two estimation techniques, including the two-step system generalized method of moments (GMM) and the method of moments quantile regression (MMQR), were used on a sample of 65 countries from 2013 to 2019. Our findings reveal that fintech development plays a vital role in promoting the consumption of renewable energy sources. However, it is crucial to recognize that rising income inequality may hinder the potential positive effects of fintech development on renewable energy consumption. A threshold of income inequality should be maintained to ensure that the positive effect of fintech development on increased renewable energy consumption is not compromised. Policy implications have emerged based on the findings from this study regarding promoting fintech development towards green economic growth and sustainable development., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Vo et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In this study, the features of resistive random access memory (RRAM) employing a straightforward Cr/MAPbI 3 /FTO three-layer structure have been examined and clarified. The device displays various resistance switching (RS) behavior at various sweep voltages between 0.5 and 5 V. The RS effect has a conversion in the direction of the SET and RESET processes during sweeping for a number of cycles at a specific voltage. The directional change of the RS processes corresponds to the dominant transition between the generation/recombination of iodide ion and vacancy in the MAPbI 3 perovskite layer and the electrochemical metallization of the Cr electrode under the influence of an electric field, which results in the conductive filament (CF) formation/rupture. At each stage, these processes are controlled by specific charge conduction mechanisms, including Ohmic conduction, space-charge-limited conduction (SCLC), and variable-range hopping (VRH). By identifying the biased voltage and the quantity of voltage sweep cycles, one can take a new approach to control or modulate the pathways for effective charge transport. This new approach is made possible by an understanding of the RS characteristics and the corresponding mechanisms causing the variation of RS behavior in the structure., (© 2023 Wiley-VCH GmbH.)

Flexible surface-enhanced Raman scattering (SERS) sensors have gained significant attention for their practical applications in detecting chemical and biological molecules. However, the fabrication of flexible SERS chips is often complex and requires advanced techniques. In this study, we present a simple and rapid method to design a flexible SERS chip based on polyvinyl alcohol (PVA), cellulose, and silver nanoparticles (AgNPs) using mechanical stirring and drying methods. Benefiting from the abundant hydroxide groups on cellulose, AgNPs easily adhere and distribute evenly on the cellulose surface. The combination of PVA and cellulose forms a bendable film-like SERS chip. This chip allows convenient immersion in liquid analyte samples. We demonstrate its effectiveness by using it to detect the thiram pesticide in apple juice using the "dip and dry" method, achieving an outstanding detection limit of 1.01 × 10 -8  M. The Raman signals on the SERS chips exhibit high repeatability and reproducibility, with relative standard deviation values below 10%. These findings show that the flexible PVA/cellulose/Ag SERS chips is a strong candidate for real-world analysis., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Anh-Tuan Le reports administrative support and equipment, drugs, or supplies were provided by Phenikaa University., (© 2023 The Authors.)

In this work, a series of unsaturated polyester resin (UPRs)/electrochemically exfoliated graphene oxide (e-GO) polymer nanocomposites with different ratios of e-GO (0.05, 0.1, 0.15, and 0.2 wt%) were prepared via an in situ polymerization method. The surface morphology and structural and chemical properties of the original UPR and UPR/e-GO nanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR). The positive influence of e-GO nanosheets on the mechanical properties, thermal stability, and anti-UV aging performance of UPR/e-GO nanocomposites was demonstrated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and dynamic mechanical analysis (DMA). The obtained results showed that the incorporation of e-GO nanosheets within the UPR matrix, despite the addition of e-GO at as low as 0.2 wt% comprehensively improves the advanced functional properties of UPR/e-GO nanocomposites as compared to the original UPR. In addition, artificial weathering testing of quartz-based artificial stone using UPR/e-GO 0.2 wt% showed excellent UV-resistant efficiency, supporting the use of e-GO nanosheets as an additive in manufacturing the industrial-scale UPRs-based artificial quartz stone samples for real outdoor applications., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (This journal is © The Royal Society of Chemistry.)

Income inequality is a vexing developmental challenge for governments and policymakers as it impedes social transformation and economic growth and development. Meanwhile, promoting financial development is generally regarded as an effective way to achieve inclusive and sustainable growth. This study examines the long-run effects of financial development, economic growth, and their combined effects on income inequality for 12 Asia-Pacific countries from 1990 to 2021. This paper employs various econometric techniques and different financial development proxies to ensure the findings' robustness. The paper also constructs a financial development index using the principal component analysis to fully capture the comprehensive effect of financial development on income inequality. Empirical results reveal that the impact of financial development on income inequality follows the inverted U-shaped relationship - financial development widens income inequality and only reduces income when surpassing its turning point. Findings further reveal that the nonlinear effect of financial development on income inequality is contingent upon the level of per capita income. Thus, policies promoting financial development to reduce income inequality should consider the existing level of per capita income., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2023 The Authors.)

Receptor-interacting serine/threonine kinase 2 (RIPK2) is a vital immunomodulator that plays critical roles in nucleotide-binding oligomerization domain 1 (NOD1), NOD2, and Toll-like receptors (TLRs) signaling. Stimulated NOD1 and NOD2 interact with RIPK2 and lead to the activation of nuclear factor kappa B (NF-κB) and mitogen-activated protein kinases (MAPK), followed by the production of pro-inflammatory cytokines such as TNF-α, IL-6, and IL-12/23. Defects in NOD/RIPK2 signaling are associated with numerous inflammatory diseases, including asthma, sarcoidosis, inflammatory bowel disease (Crohn's disease and ulcerative colitis), multiple sclerosis, and Blau syndrome. As RIPK2 is a crucial element of innate immunity, small molecules regulating RIPK2 functions are attractive to establish novel immunotherapies. The increased interest in developing RIPK2 inhibitors has led to the clinical investigations of novel drug candidates. In this review, we attempt to summarize recent advances in the development of RIPK2 inhibitors and degraders., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Pham, Ghilardi and Sun.)

This study investigated CuO and ZnO nanoparticles and CuO/ZnO nanocomposites in a friendly environment with a low-cost and renewable biosynthesis method. This approach involved using Boehmeria nivea leaf extract to facilitate the growth and formation of nanocomposites with performance-enhancing phytochemicals released during the co-precipitation process. All nanoparticles/nanocomposites explored the microstructure, morphology, and point defects using FTIR, XRD, SEM, and PL characterization techniques. The synthesized CuO and ZnO nanoparticles and CuO/ZnO nanocomposites were evaluated for their antibacterial ability against both bacteria Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Combining different copper and zinc salt ratios creates different arrangements and morphologies between the CuO sheets and the spherical ZnO nanoparticles. The heterojunction of CuO/ZnO samples enhances the antibacterial effects of nanocomposites compared to pure CuO and ZnO nanoparticles. The maximum antibacterial performance was achieved at 250 ppm against E. coli and 500 ppm against S. aureus in CuO50/ZnO50 nanocomposites. This study shows that a green synthesis of CuO/ZnO nanocomposites promises great potential for environmental treatment and biochemical applications., (2022 Published under an exclusive license by the AVS.)

Whole-genome sequencing and genome mining are recently considered an efficient approach to shine more light on the underlying secondary metabolites of Streptomyces . The present study unearths the biosynthetic potential of endophytic SX6 as a promising source of biologically active substances and plant-derived compounds for the first time. Out of 38 isolates associated with Aegiceras corniculatum (L.) Blanco, Streptomyces parvulus SX6 was highly active against Pseudomonas aeruginosa ATCC® 9027™ and methicillin-resistant Staphylococcus epidermidis (MRSE) ATCC® 35984™. Additionally, S. parvulus SX6 culture extract showed strong cytotoxicity against Hep3B, MCF-7, and A549 cell lines at a concentration of 30 μg/ml, but not in non-cancerous HEK-293 cells. The genome contained 7.69 Mb in size with an average G + C content of 72.8% and consisted of 6,779 protein-coding genes. AntiSMASH analysis resulted in the identification of 29 biosynthetic gene clusters (BGCs) for secondary metabolites. Among them, 4 BGCs showed low similarity (28-67% of genes show similarity) to actinomycin, streptovaricin, and polyoxypeptin gene clusters, possibly attributed to antibacterial and anticancer activities observed. In addition, the complete biosynthetic pathways of plant-derived compounds, including daidzein and genistein were identified using genome mining and HPLC-DAD-MS analysis. These findings portray an exciting avenue for future characterization of promising secondary metabolites from mangrove endophytic S. parvulus ., (© 2022 Ngoc Tung Quach et al., published by Sciendo.)

Ellman's reagent has caused substantial confusion and concern as a probe for thiol-mediated uptake because it is the only established inhibitor available but works neither efficiently nor reliably. Here we use fluorescent cyclic oligochalcogenides that enter cells by thiol-mediated uptake to systematically screen for more potent inhibitors, including epidithiodiketopiperazines, benzopolysulfanes, disulfide-bridged γ-turned peptides, heteroaromatic sulfones and cyclic thiosulfonates, thiosulfinates and disulfides. With nanomolar activity, the best inhibitors identified are more than 5000 times better than Ellman's reagent. Different activities found with different reporters reveal thiol-mediated uptake as a complex multitarget process. Preliminary results on the inhibition of the cellular uptake of pseudo-lentivectors expressing SARS-CoV-2 spike protein do not exclude potential of efficient inhibitors of thiol-mediated uptake for the development of new antivirals., Competing Interests: A U.S. Patent application has been filed (No. 63/073863)., (This journal is © The Royal Society of Chemistry.)

Epoxide-opening ether cyclizations are shown to occur on π-acidic aromatic surfaces without the need of additional activating groups and with autocatalytic amplification. Increasing activity with the intrinsic π acidity of benzenes, naphthalenediimides (NDIs) and perylenediimides (PDIs) support that anion-π interactions account for function. Rate enhancements maximize at 270 for anion-π catalysis on fullerenes and at 5100 M -1 for autocatalysis. The occurrence of anion-π autocatalysis is confirmed with increasing initial rates in the presence of additional product. Computational studies on autocatalysis reveal transition state and product forming a hydrogen-bonded noncovalent macrocycle, like holding their hands and dancing on the active π surface, with epoxide opening and nucleophile being activated by anion-π interactions and hydrogen bonds to the product, respectively.

We demonstrate a high-performance photodetector with multilayer tin diselenide (SnSe2) exfoliated from a high-quality crystal which was synthesized by the temperature gradient growth method. This SnSe2 photodetector exhibits high photoresponsivity of 5.11 × 105 A W-1 and high specific detectivity of 2.79 × 1013 Jones under laser irradiation (λ = 450 nm). We also observed a reproducible and stable time-resolved photoresponse to the incident laser beam from this SnSe2 photodetector, which can be used as a promising material for future optoelectronic applications.