Publications by authors named "Ka Ming Ng"

This article presents a numerical platform for predicting the performance of paper-based analytical devices. The capillary flow, reaction, dissolution, and other physicochemical phenomena associated with device operation are accounted for using Darcy's law, Richard's equation and other transport equations. The platform can be used for different paper substrates, biorecognition methods, detection systems (such as optical and electrochemical detection), device patterns and dimensions, and ways in which the device is operated such as the input method of the body fluid.

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A novel calcium copper titanate (CaCuTiO)-polyvinylidene fluoride composite (CCTO@PVDF) with Cu-deficiency was successfully prepared through the molten salt-assisted method. The morphology and structure of polymer composites uniformly incorporated with CCTO nanocrystals were characterized. At the same volume fraction, the CCTOs with Cu-deficiency displayed higher dielectric constants than those without post-treatment.

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Galectin-3 is a vital biomarker for cancer progression. An aggregation-induced emission (AIE)-active nanoparticle probe is designed and synthesized for label-free detection of galectin-3 based on carbohydrate-protein interactions. The probe employs tetraphenylethene (TPE) as the fluorescent core structure and N-acetyllactosamine (LacNAc) as galactoside residues and self-aggregates into uniform nanoparticles with multiple binding sites on the surface targeting galectin-3.

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We report the thermoelectric performance of p-type nanocrystalline SnSe obtained from the liquid phase sintering of blends of SnSe nanocrystals and Te nanorods. A cycled hot press procedure at a temperature above the Te melting point promoted the formation of crystallographically textured SnSe nanomaterials with relative densities up to 93%. After consolidation, part of this Te was found within the SnSe lattice and part remained as elemental Te between the SnSe grains.

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In the present work, we detail a fast and simple solution-based method to synthesize hexagonal SnSe nanoplates (NPLs) and their use to produce crystallographically textured SnSe nanomaterials. We also demonstrate that the same strategy can be used to produce orthorhombic SnSe nanostructures and nanomaterials. NPLs are grown through a screw dislocation-driven mechanism.

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Hypoxanthine is a well-known indicator of intracellular energy status that is associated with many pathological conditions. We report a fluorescent luminogen (TPE-HPro) with aggregation-induced emission (AIE) feature which, along with xanthine oxidase (XO), detects and quantifies hypoxanthine in a "turn-on" manner. The superior detection performance of this fluorometric assay indicates its great potential for biomedical diagnostics.

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In the present work, we demonstrate crystallographically textured n-type BiTeSe nanomaterials with exceptional thermoelectric figures of merit produced by consolidating disk-shaped BiTeSe colloidal nanocrystals (NCs). Crystallographic texture was achieved by hot pressing the asymmetric NCs in the presence of an excess of tellurium. During the hot press, tellurium acted both as lubricant to facilitate the rotation of NCs lying close to normal to the pressure axis and as solvent to dissolve the NCs approximately aligned with the pressing direction, which afterward recrystallize with a preferential orientation.

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Bottom-up approaches for producing bulk nanomaterials have traditionally lacked control over the crystallographic alignment of nanograins. This limitation has prevented nanocrystal-based nanomaterials from achieving optimized performances in numerous applications. Here we demonstrate the production of nanostructured Bi SbTe alloys with controlled stoichiometry and crystallographic texture through proper selection of the starting building blocks and the adjustment of the nanocrystal-to-nanomaterial consolidation process.

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Iron sulfide embedded porous carbon hollow spheres (FeS@CS) have been successfully synthesized through a facile and environment friendly in situ synthetic method. Using this method, a porous carbon matrix and uniformly dispersed iron sulfide nanoparticles were formed simultaneously and assembled into hollow spheres. The as-synthesized FeS@CS material showed high reversible capacity, outstanding cycle performance, and excellent rate capability when it was applied as an anode material for sodium ion batteries.

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Silicon doped tin oxide embedded porous carbon microspheres (Si Sn O @C) are synthesized. It is found that the doped Si not only improves the reversibility of lithiation/delithiation reactions, but also prevents Sn from aggregation. In addition, the doped Si introduces extra defects into the carbon matrix and produces Li conductive Li SiO , which accelerates Li diffusion.

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l-Lactate is a vital biomarker for many diseases and physiological fatigue. An AIE-active fluorophore (TPE-HPro) is combined with l-lactate oxidase (LOx) to determine l-lactate in aqueous fluid. The assay shows excellent sensitivity and anti-interference performance with a limit of detection (LOD) of 5.

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We report a novel hybrid electrolyte based on mesoporous silica nanoparticles decorated with an ionic liquid, which exhibits a superior lithium ion transference number of >0.8, and an excellent electrochemical window of >5 V with attractive ionic conductivity. The insights obtained pave a new way for the preparation of high-performance electrolytes with mesoporous structures.

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1-[4-(Bromomethyl)phenyl]-1,2,2-triphenylethene (2) was synthesized and evaluated for specific fluorescent prestaining of proteins containing cysteine (Cys) in SDS-PAGE. The molecule showed classic aggregation-induced emission (AIE) property in protein labeling and its quantum efficiency was further enhanced upon reacting with Cys. The parameters of reaction such as labeling time and concentration of dye and reducing reagent-tris(2-carboxyethyl)phosphine (TCEP) were examined to obtain the optimal labeling condition.

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A new aggregation-induced emission (AIE) compound 1,2-bis[4-(isothiocyanatomethyl)phenyl]-1,2-diphenylethene (2) was synthesized for use in SDS-PAGE. The molecule is practically nonemissive in solution but becomes highly emissive after reacting with the amine groups of the proteins by either the prestaining or poststaining method. The sensitivity of 2 achieved in the prestaining method is the same as that of Coomassie brilliant blue (CBB), while that observed in the poststaining method is higher than that of CBB.

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A new aggregation-induced emission (AIE) compound 1,1-dimethyl-2,5-bis[4-(isothiocyanatemethyl)phenyl]-3,4-diphenylsilole (SITC) was synthesized and used to conjugate with aminoallyl-dUTP. The SITC-dUTP can be incorporated enzymatically into DNA strands with the degree of labeling (DOL) up to the theoretic limit.

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Aim Of The Study: A novel topical paste used for fracture healing (FH), consisting of the extracts of six herbs, Radix Dipsaci, Ramulus Sambucus Williamsii, Rhizoma Notoginseng, Flos Carthami, Rhizoma Rhei and Fructus Gardeniae, was developed according to the classical theory of traditional Chinese medicine. This study aimed to determine the effectiveness of this formula, and some of its important chemical components in the promotion of fracture healing. The transdermal transport of FH was also examined.

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A novel gamma-MnO(2) hollow structure has been synthesized at room temperature using a simple chemical reaction between MnSO(4) and KMnO(4) in aqueous solution without using any templates, surfactants, catalysts, calcination and hydrothermal processes. The synthesized gamma-MnO(2) hollow structure was characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and BET analysis. It was found that the hollow structure consisting of short gamma-MnO(2) nanorods with diameters of 5-10 nm and lengths of 50-100 nm could form when the MnSO(4)/KMnO(4) mole ratio was equal to or larger than 2.

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Poly(methyl methacrylate) (PMMA)/multiwalled carbon nanotube (MWCNT) nanocomposite particles with 1, 2 and 4 wt% of MWCNTs were prepared by mechanical grinding of PMMA and MWCNT powders in a mortar at room temperature. Both scanning electron microscopy and Raman scattering characterizations revealed that these nanocomposite particles consist of a PMMA core and a MWCNT shell. The PMMA/MWCNT nanocomposite particles were used to fabricate the corresponding nanocomposites in the form of a hollow cylinder with various diameters and heights under 700 W microwave irradiation within 1 min.

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The effects of the schisandrin B stereoisomers, (+/-)gamma-schisandrin [(+/-)gamma-Sch] and (-)schisandrin B [(-)Sch B], on hypoxia/reoxygenation-induced apoptosis were investigated in AML12 hepatocytes. Changes in cellular reduced glutathione (GSH) levels, Ca(2+)-induced mitochondrial permeability transitions (MPTs) and mitochondrial membrane potentials (Deltapsi(m) values) were also examined in (+/-)gamma-Sch- and (-)Sch B-treated cells, without or with hypoxia/reoxygenation challenge. The (+/-)gamma-Sch/(-)Sch B pretreatments (2.

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The effects of schisandrin B stereoisomers, (+/-)gamma-schisandrin [(+/-)gamma-Sch] and (-)schisandrin B [(-)Sch B], on hypoxia/reoxygenation-induced apoptosis were investigated in H9c2 cardiomyocytes. Changes in cellular reduced glutathione (GSH) levels, Ca(2+)-induced mitochondrial permeability transition (MPT), and mitochondrial membrane potential (Deltapsi(m)) values, were examined in (+/-)gamma-Sch-pretreated and (-)Sch B-pretreated cells, without or with hypoxia/reoxygenation challenge. The (+/-)gamma-Sch and (-)Sch B (2.

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Soybean isoflavones have multiple beneficial health effects especially on estrogen-deficient diseases such as menopausal symptoms. In this study, isoflavones were produced from soybean flour, and the extraction and purification parameters were optimized to give a high yield of total isoflavones, about 0.62 mg of aglycones/g of soybean flour, which is >2 times the initial yield.

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Although tin oxide has been the most widely investigated metal oxide material for gas detection, it suffers from the large resistance and high operating temperature. This could be overcome by hybridization with nanostructured carbon. In this work, tin oxide nanoparticles with ultrasmall sizes of 1-3 nm have been uniformly coated onto bundles of single-walled carbon nanotubes by a surfactant assisted solid state synthesis approach for the first time.

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An ordered mesoporous carbon, CMK-3, was synthesized using a mesoporous siliceous material, SBA-15, as the template. CMK-3 was characterized and used for the adsorption of fullerenes C60 and C70. It was found that the adsorption capacity of CMK-3 is 4 times higher than that of activated carbon.

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