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In order to advance sustainable energy technologies like fuel cells and metal-air batteries, it is crucial to use an electrocatalyst that is very efficient for the process of oxygen evolution. The production of Co3O4 nanostructures led to the creation of a multiporous nanostructure. The research used an approach that utilised a simple, cost-effective, and low-temperature synthesis procedure. The catalytic activity of Co3O4 nanostructures, which have a high degree of porosity and include mesoporous nanostructures, was shown to be substantial. The catalyst has the ability to enhance the highly reactive oxygen reactions at the anode, hence increasing the combined effect of charge transfer at the interface and the porous structure of Co3O4 nanostructures. The results of this study demonstrate that Co3O4 nanostructures exhibit a significant overpotential value of 321 mV at 10 mA/cm2, a Tafel slope of 72 mV Dec−1, and excellent stability when used as electrocatalysts for the oxygen evolution process (OER) in real-world situations. [ABSTRACT FROM AUTHOR]

The current study aims to develop a unique approach for constructing an asymmetric supercapacitor utilizing a nanocomposite of MgO-carbon as electrode material. The geometrical surface area of the MgO-carbon has shown to be highly porous with different porosities, and the value is 210 m2g−1. This supercapacitor operates with an aqueous electrolyte consisting of 1 M KOH. The findings indicate that the test cell exhibited exceptional electrochemical output within the voltage range of 0 to 1 V. The capacitance of the MgO-carbon cell is measured to be 225 F g−1 at a current density of 2 A g−1. According to research on cycling, the aforementioned cell has demonstrated the ability to maintain 97% of its original capacitance following 20,000 cycles. The findings of this study suggest that the MgO-carbon holds promise as an electrode material for the development of environmentally friendly and cost-effective energy storage devices. This composite exhibit excellent energy and power densities, along with a prolonged cycle life. [ABSTRACT FROM AUTHOR]

The development of renewable energy technologies, such as fuel cells and metal-air batteries, relies heavily on the availability of highly efficient electrocatalysts for the oxygen evolution reaction (OER). In this study, a mesoporous Fe3O4-ZnO nanocomposites was synthesized using a simple and economically viable approach at a relatively low temperature. The observed catalytic activity of the prepared Fe3O4-ZnO nanocomposites mesoporous nanostructure was found to be remarkable. Additionally, the nanostructure exhibited a high tolerance to methanol and demonstrated durability towards oxygen evolution reaction (OER) in alkaline media. In the course of the experiment, it was observed that the catalyst exhibited noteworthy activity in the oxygen evolution reaction (OER) when compared to the commercially available RuO2 catalyst. This was evident through a more negative onset potential and higher current. The catalyst's notable capacity for high oxygen reaction activity may potentially enhance the synergistic effect resulting from the combination of defect sites and the porous structure of Fe3O4-ZnO nanocomposites. The findings of this study indicate that the Fe3O4-ZnO nanocomposites exhibit promising attributes as an electrocatalyst with overpotential and Tafel slope value of 350 mV and 62 mVdec−1 for the oxygen evolution reaction (OER) in real-world scenarios. [ABSTRACT FROM AUTHOR]

Organoids are three-dimensional structures of self-assembled cell aggregates that mimic anatomical features of in vivo organs and can serve as in vitro miniaturized organ models for drug testing. The most efficient way of studying drug toxicity and efficacy requires high-resolution imaging of a large number of organoids acquired in the least amount of time. Currently missing are suitable platforms capable of fast-paced high-content imaging of organoids. To address this knowledge gap, we present the OrganoidChip, a microfluidic imaging platform that incorporates a unique design to immobilize organoids for endpoint, fast imaging. The chip contains six parallel trapping areas, each having a staging and immobilization chamber, that receives organoids transferred from their native culture plates and anchors them, respectively. We first demonstrate that the OrganoidChip can efficiently immobilize intestinal and cardiac organoids without compromising their viability and functionality. Next, we show the capability of our device in assessing the dose-dependent responses of organoids' viability and spontaneous contraction properties to Doxorubicin treatment and obtaining results that are similar to off-chip experiments. Importantly, the chip enables organoid imaging at speeds that are an order of magnitude faster than conventional imaging platforms and prevents the acquisition of blurry images caused by organoid drifting, swimming, and fast stage movements. Taken together, the OrganoidChip is a promising microfluidic platform that can serve as a building block for a multiwell plate format that can provide high-throughput and high-resolution imaging of organoids in the future. [ABSTRACT FROM AUTHOR]

Motivated by the wide-band-gap semiconductor properties of Zn-monochalcogenides (Zn-X; X:S, Se and Te), especially for their crucial industrial applications, we use a first-principles approach to investigate the B3 (zinc blende type) to B1 (rock salt type) structural transitions in this series of compounds as a function of pressure and temperature. Under static conditions (i.e., T = 0 K), the transition pressure is found to steadily drop from ZnS to ZnTe via intermediate ZnSe. Our calculations within quasi-harmonic approximation yield negative Clapeyron slopes of the B3–B1 phase boundaries for all the three compounds, where ZnTe has the highest negative slopes. We also present a completely new set of calculations for the thermoelasticity of Zn-X phases in the temperature range 0–1100 K. This article then addresses how the B3–B1 phase transitions can influence the mechanical as well as electronic properties of Zn-X. This phase transition always results in a softening of their elastic constant C12; however, C11 and C44 get stiffened. The same structural transition switches a semiconductor to conductor-type electronically favorable transition, as inferred from their high-pressure electronic structure. Among the three Zn-X compounds, ZnTe becomes the most metallic phase following the B3–B1 transition. Our findings offer a novel explanation for the complete loss of semiconductor property of these monochalcogenides at elevated pressures. [ABSTRACT FROM AUTHOR]

In the present manuscript, a model of thermoelasticity with diffusion considering elastic nonlocality is applied to study transient vibrations in a hollow sphere under the action of harmonically varying heat sources. The inner and outer surfaces of the sphere are kept stress free and free from concentration of diffusion. In addition, the outer surface is considered isothermal and the inner surface of the sphere is subjected to a harmonically varying heat source along the radial direction. Analytical results have been verified through computations with MATLAB computer-based tools. The data generated with the help of numerical simulations have been presented graphically for temperature, dilatation, displacement, chemical potential, radial and the de-hoop stresses with nonlocal/local elastic materials. From the behaviour of the field quantities, it clearly indicates that the variations of the above physical quantities for the GL model is larger in contrast to the LS, CTE and E models of thermoelasticity. The present model may be implemented predominantly in cosmetics industry, navigation, bearings and also for the progress of practical applications in geo-magnetics, optics, acoustics etc. [ABSTRACT FROM AUTHOR]

Imaging modalities combined with a multimodal nanocomposite contrast agent hold great potential for significant contributions in the biomedical field. Among modern imaging techniques, photoacoustic (PA) and fluorescence (FL) imaging gained much attention due to their non-invasive feature and the mutually supportive characteristic in terms of spatial resolution, penetration depth, imaging sensitivity, and speed. In this present study, we synthesized IR783 conjugated chitosan–polypyrrole nanocomposites (IR-CS–PPy NCs) as a theragnostic agent used for FL/PA dual-modal imaging. A customized FL and photoacoustic imaging system was constructed to perform required imaging experiments and create high-contrast images. The proposed nanocomposites were confirmed to have great biosafety, essentially a near-infrared (NIR) absorbance property with enhanced photostability. The in vitro photothermal results indicate the high-efficiency MDA-MB-231 breast cancer cell ablation ability of IR-CS–PPy NCs under 808 nm NIR laser irradiation. The in vivo PTT study revealed the complete destruction of the tumor tissues with IR-CS–PPy NCs without further recurrence. The in vitro and in vivo results suggest that the demonstrated nanocomposites, together with the proposed imaging systems could be an effective theragnostic agent for imaging-guided cancer treatment. [ABSTRACT FROM AUTHOR]

We investigate the thermoelastic interactions in an isotropic and homogeneous perfectly conducting two-dimensional semi-infinite elastic medium. The bounding surface of the medium is assumed as stress free and subjected to a time-dependent thermal shock. A new two-temperature generalized thermoelasticity theory with memory-dependent derivative is employed for this study. The combined Laplace–Fourier transforms are applied to solve the non-dimensional governing equations to find the solutions for the field variables in the transform domain. An application is considered to enable us to get complete solutions. Numerical results of the field variables are presented graphically to discuss the effect of various parameters of interest. [ABSTRACT FROM AUTHOR]

Fractional derivative is a widely accepted theory to describe the physical phenomena and the processes with memory effects which is defined in the form of convolution-type integrals involving kernels as power functions. Due to the shortcomings of power law distributions, some other forms of derivatives with few other kernel functions have been proposed. This present survey deals with a novel mathematical model of generalized thermoelasticity which investigates the transient phenomena due to the influence of an induced magnetic field and the presence of moving heat source in a thermoelastic rod in the context of Lord–Shulman (LS) theory of generalized thermoelasticity. Both ends of the rod are fixed and are thermally insulated. Employing the Laplace transform, the problem has been transformed to the space-domain have been solved analytically. Finally, solutions in the real-time domain are obtained on applying the numerical inversion of Laplace transform, which has been carried out employing the Riemann-sum approximation method. Numerical computations for stress, displacement and temperature within the rod is carried out and have been demonstrated graphically. The results also demonstrate how the speed of the moving heat source influences the thermophysical quantities. It is observed that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed. Also, significant differences on the thermophysical quantities are revealed due to the influence of magnetic field and memory effect also. [ABSTRACT FROM AUTHOR]

The model of two-dimensional plane waves is studied in a generalized thermoelastic medium under memory-dependent derivative in the Lord–Shulman model. The normal mode analysis is used to obtain the exact expressions for the temperature distribution, the displacement component and the thermal stress component. The resulting formulation is applied to a concrete problem that deals with a thick plate subjected to a time-dependent heat source on each face. According to the graphical representations, corresponding to the numerical results, the effect of the different kernel has studied different thermophysical quantities at different times. Moreover, graphs are drawn to show the influence of rotation in all the thermophysical quantities. Some three-dimensional figures also are drawn for a better understanding of thermophysical quantities in the different positions of the body. As per the author's knowledge, the effect of rotation with the memory effect is not available in the literature till now. The differences for different kernel functions are also presented at different times. [ABSTRACT FROM AUTHOR]

Enlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena due to the influence of magnetic field and moving heat source in a rod in the context of dual-phase lag (DPL) theory of thermo-visco-elasticity. Both ends of the rod are fixed and heat insulated. Employing Laplace transform as a tool, the problem has been transformed into the space-domain and solved analytically. Finally, solutions in the real-time domain are obtained by applying the inverse Laplace transform. Numerical calculation for stress, displacement, and temperature within the rod is carried out and displayed graphically. The effect of moving heat source speed on temperature, stress, and displacement is studied. It is found from the distributions that the temperature, thermally induced displacement, and stress of the rod decrease at large source speed. [ABSTRACT FROM AUTHOR]

The Fractional derivative is a widely accepted theory to describe physical phenomena and the processes with memory effects which is defined in the form of convolution having kernels as power functions. Due to the shortcomings of power-law distributions, some other forms of derivatives with few other kernel functions are proposed. This present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena due to the influence of the magnetic field and moving heat source in a thermoelastic rod in the context of the Lord–Shulman (LS) theory of generalized thermo-visco-elasticity. Both ends of the rod are fixed and are thermally insulated. Employing the Laplace transform as a tool, the problem has been transformed into the space-domain and solved analytically. Finally, solutions in the real-time domain are obtained on applying the numerical inversion of the Laplace transform, which has been carried out employing the Riemann sum approximation method. Numerical computations for stress, displacement, and temperature within the rod is carried out and have been demonstrated graphically. The results also demonstrate how the speed of the moving heat source influences the thermophysical quantities. It is observed that the temperature, thermally induced displacement and stress of the rod are found to decrease at large source speed. Also, significant differences in the thermophysical quantities are revealed due to the influence of the magnetic field and memory effect [ABSTRACT FROM AUTHOR]

Densities and ultrasonic velocities were measured for the mixtures of (nitrobenzene + cyclohexane) and (N,N-dimethylformamide + cyclohexane) over the volume fraction range 0.1–1 at 298–318 K. Different derived parameters such as adiabatic compressibility, Intermolecular free length, acoustic impedance, molar volume, molar sound velocity, molar compressibility, relative association, excess volume, and excess adiabatic compressibility have been computed. The observed positive and negative values of the excess parameters for all the studied mixtures were explained based on the intermolecular interactions in these mixtures. Furthermore, different empirical relations were used to compare the binary mixture densities and ultrasonic velocities. [ABSTRACT FROM AUTHOR]

This present work is devoted to the investigation of the transient phenomena for a fiber-reinforced medium with a cylindrical cavity in the context of the three-phase-lag model of generalized thermoelasticity with a new form of derivative of the Caputo–Fabrizio (CF) type in the heat transport equation, where the medium is under the action of an induced magnetic field. The Laplace transform is incorporated as a tool for the solution of the problem when the boundary of the cavity is exposed to harmonically varying heat with a constant angular frequency of thermal vibration. The numerical inversion of the Laplace transforms is computed using the Zakian method. Excellent predictive capability is demonstrated due to the presence of reinforcement, the angular frequencies on thermal vibrations, CF fractional parameter and magnetic field. [ABSTRACT FROM AUTHOR]

Enlightened by the Caputo fractional derivative, the present study deals with a novel mathematical model of generalized thermoelasticity to investigate the transient phenomena for a piezoelastic half-space due to the influence of a magnetic field in the context of the dual-phase-lag model of generalized thermoelasticity, which is defined in an integral form of a common derivative on a slipping interval by incorporating the memory-dependent heat transfer. The bounding plane of the medium is assumed to be stress free and subjected to a thermal shock. Employing the Laplace transform as a tool, the problem is transformed to the space domain, where the solution in the space–time domain is achieved by applying a suitable numerical technique based on Fourier series expansion technique. According to the graphical representations corresponding to the numerical results, conclusions about the new theory are constructed. Excellent predictive capability is demonstrated due to the presence of electric field, memory-dependent derivative and magnetic field. [ABSTRACT FROM AUTHOR]

We have thoroughly studied the luminescence behaviour of a cadmium based MOF, [Cd(C12N2H8)(C7N1O4H3)] {C12N2H8 = 1,10-phenanthroline, C7N1O4H3 = 2,5-pyridine dicarboxylate}, 1. Both steady-state and time-resolved luminescence spectroscopic experiments were performed to understand the dissimilar responses of compound 1 towards different metal ions in aqueous medium. Upon excitation at 280 nm, compound 1 showed a luminescence spectrum centered at 365 nm, which exhibited a three-fold turn-on in the presence of a trace amount of Zn2+ in aqueous solution, whereas in the presence of Co2+, Hg2+, Ni2+, Fe2+ and Cu2+ the luminescence of compound 1 got largely quenched. Compound 1 did not show any response in the presence of other common metal ions such as K+, Mg2+, Na+, Mn2+, and Cr3+. By analysing all the experimental results, we successfully explained the versatile luminescence behaviour of compound 1. The turn-on of luminescence in the presence of Zn2+ ions was due to coordination bond formation and enhancement of the rigidity of compound 1 which resulted in the reduction of non-radiative decay processes to a large extent. The quenching of luminescence in the presence of transition metal ions was found to be static in nature, and was due to the possibility of ligand to metal charge transfer using the vacant d-orbital of the metal ions. In the case of Hg2+ which is a closed cell heavy metal ion, the quenching of luminescence was also static in nature and was due to a two-way charge transfer mechanism. We have also performed density functional theory calculations and obtained supportive results for the proposed mechanisms of luminescence turn-on and quenching. Moreover, compound 1 could be established as a selective and efficient sensor of Zn2+ in aqueous solution even in the presence of Cd2+ and other metal ions. [ABSTRACT FROM AUTHOR]

Biopolymer-coated drug delivery system with high drug-loading efficiency and pH-stimuli responsive drug release to the target site receives much research interest in cancer therapy. In this study, we have synthesized a marine biopolymer, namely chitosan oligosaccharide (COS) coated mesoporous silica nanoparticle (MSNs@COS NPs) system for pH-responsive drug delivery applications. The COS coating onto the silica nanoparticles was performed through metal–ligand complex coordination approaches. The prepared MSNs@COS NPs system were characterized by low-angle X-ray diffraction (XRD), Fourier-transform infrared (FTIR), N2 adsorption–desorption and transmission electron microscopic (TEM), and thermogravimetric analyses. The COS-coated MSNs@COS NPs system shows high drug-loading capacity, good drug retention efficiency under physiological pH (pH 7.4) conditions, and an intracellular pH-responsive drug release behavior under acidic pH (pH 6.5, 5.0, and 4.0) environments. Furthermore, the biocompatibility and the intracellular uptake behavior of the MSNs@COS NPs system were evaluated by using MDA-MB-231 cells. The in vitro cytotoxicity and fluorescence microscopic analysis results evidenced that the synthesized MSNs@COS NPs system is biocompatible and could be readily taken up by MDA-MB-231 cells. Therefore, we believe that the proposed system could be applicable for pH-stimuli responsive controlled drug delivery applications in cancer therapy. [ABSTRACT FROM AUTHOR]

Abstract: Densities and ultrasonic velocities of binary mixtures of (nitromethane + acetone) and (acetone + nitroethane) in the volumes fraction range 0.1-1 at 298-318 K were measured. The obtained data were used to compute adiabatic compressibility, intermolecular free length, acoustic impedance, molar volume, molar sound velocity, molar compressibility, relative association, excess volume, and excess adiabatic compressibility. The results were discussed in terms of the existence of dipole-dipole and dipole induced molecular interactions between the compounds in the liquid mixture under study. A comparative study has been established between two liquid mixtures under investigation. [ABSTRACT FROM AUTHOR]

Three-dimensional, fluorescence imaging methods with ~1 MHz frame rates are needed for high-speed, blur-free flow cytometry and capturing volumetric neuronal activity. The frame rates of current imaging methods are limited to kHz by the photon budget, slow camera readout, and/or slow laser beam scanners. Here, we present line excitation array detection (LEAD) fluorescence microscopy, a high-speed imaging method capable of providing 0.8 million frames per second. The method performs 0.8 MHz line-scanning of an excitation laser beam using a chirped signal-driven longitudinal acousto-optic deflector to create a virtual light-sheet, and images the field-of-view with a linear photomultiplier tube array to generate a 66 × 14 pixel frame each scan cycle. We implement LEAD microscopy as a blur-free flow cytometer for Caenorhabditis elegans moving at 1 ms−1 with 3.5-μm resolution and signal-to-background ratios >200. Signal-to-noise measurements indicate future LEAD fluorescence microscopes can reach higher resolutions and pixels per frame without compromising frame rates. [ABSTRACT FROM AUTHOR]

The chemotherapy combined with thermotherapy is greatly considered in clinical applications for cancer treatment. The fabrication of nanomaterials with multifunctionality is an attractive approach to be utilized in cancer therapy. In this work, we report the synthesis of dopamine-urea organosilane (DPU) integrated mesoporous silica material in which the magnetic Fe3O4 nanoparticles were grown onto the outer surface of the mesoporous silica nanoparticles via Fe3O4-dopamine complexation method. The mesoporous structural characterization results revealed that the synthesized Fe3O4@DPU@MSH materials had high surface area (386 m2/g), large pore size (4.5 nm) and uniform particles in which the magnetic Fe3O4 nanoparticles were grown onto the outer surface of the mesopore walls with the particles size about 5-10 nm. Because of the existence of Fe3O4 nanoparticles onto the outer surface of the Fe3O4@DPU@MSH material, the sample shows superparamagnetic properties and high magnetic hyperthermia ability in the presence of applied magnetic field. Furthermore, owing to the presence of high surface area, the Fe3O4@DPU@MSH shows high drug loading capacity, and pH-responsive and temperature-accelerated drug release efficiency. In addition, the MTT assay analysis and the intracellular uptake study results support that the synthesized Fe3O4@DPU@MSH material is biocompatible. Therefore, the Fe3O4@DPU@MSH material would be a promising material for drug delivery and magnetic hyperthermia applications in cancer therapy. [ABSTRACT FROM AUTHOR]

In the present study, hydroxyapatite (HAp) is synthesized from different biosources like eggshell, fish scale and bovine bone in a cost effective and ecofriendly way. HAp materials were synthesized from eggshell by wet precipitation method whereas thermal decomposition method was applied in case of fish scale and bovine bone. The phase purity and crystallinity of different calcined HAp powder were determined by XRD and FTIR analyses. The thermogravimetric analysis was carried out to show thermal stability of HAp powder. Average grain sizes of sintered samples were in submicron range. The morphology of the powders were observed under scanning electron microscopy (SEM). The dried powders were wet ball milled for several hours and surfactants like Triton-X small fillers (2 / 4 mm long rod-shaped) were made for in vitro testing. In order to verify the biocompatibility of HAp powders, cytotoxicity evaluation was carried out in RAW macrophage like cell line media for an incubation period of 72 h. The cell attachment studies on HAp compacts show an excellent affinity between cells and compact surface. These results proved high biocompatibility of HAp powders obtained from different biosources for tissue engineering applications. [ABSTRACT FROM AUTHOR]

Excited-state proton transfer (ESPT) of pyranine (8-hydroxypyrene-1,3,6-trisulphonate, HPTS) to acetate in methanol has been studied by steady-state and time-resolved fluorescence spectroscopy. The rate constant of direct proton transfer from pyranine to acetate (k1) is calculated to be ∼1 x 109 M-1 s-1. This is slower by about two orders of magnitude than that in bulk water (8 x 1010 M-1 s-1) at 4 M acetate. [ABSTRACT FROM AUTHOR]