Synthesis of Fe—Ni—Ce trimetallic catalyst nanoparticles via impregnation and co-precipitation and their application to dye degradation

In this study, trimetallic catalysts were prepared via the co-precipitation and impregnation methods. In order to investigate the effect of impregnation on the catalytic activity and crystallite size, a trimetallic catalyst, Fe—Ni—Ce, was prepared through the co-precipitation method in one set of experiments, and cerium was impregnated with the Ni—Fe mixture in the final stage of the preparation in another set. Fourier transform infrared spectroscopy was employed to confirm the formation of trimetallic catalysts and the success of the impregnation method. The Brunauer-Emmett-Teller nitrogen adsorption isotherm exhibits a high specific surface area (approximately 39 m² g^?1) for the nanoparticles obtained by the impregnation method. The crystallography and morphology of the trimetallic catalysts thus prepared were characterised by X-ray diffraction and scanning electron microscopy. UV-VIS spectroscopy and methylene blue dye degradation tests were also performed to investigate the catalytic activity of the synthesised catalysts. The crystalline size was found to be smaller for the catalysts prepared by the impregnation method. In addition, the samples synthesised using the cerium impregnation method showed superior activity in the methylene blue dye degradation test. The effect of the catalyst dosage on dye degradation, as well as the effect of the initial dye concentration on the catalyst activity, was also studied for both methods.     

Bipolar Electrode-based Electrochromic Devices for Analytical Applications – A Review

Bipolar electrode-based (BPE-based) electrochromic devices have garnered increasing attention in the past decade. These BPE-based electrochromic devices have been used for analytical health monitoring, point-of-care (POC) diagnostics, and chemical sensing. In this review, we highlight recent progress made regarding BPE-based electrochromic devices constructed for these analytical applications. Various, available electrochromic materials are summarized in the first section, after which the different device types (e. g., paper-based and self-powered) are discussed. Biological- and chemical-based analytical demonstrations of these devices are then reviewed. Finally, we conclude this review with a perspective on the future developments of BPE-based electrochromic devices in analytical applications.     

Beneficial Effects of Green Tea Catechins on Female Reproductive Disorders: A Review

Tea is one of the most widely consumed beverages worldwide after water, and green tea accounts for 20% of the total tea consumption. The health benefits of green tea are attributed to its natural antioxidants, namely, catechins, which are phenolic compounds with diverse beneficial effects on human health. The beneficial effects of green tea and its major bioactive component, (−)-epigallocatechin-3-gallate (EGCG), on health include high antioxidative, osteoprotective, neuroprotective, anti-cancer, anti-hyperlipidemia and anti-diabetic effects. However, the review of green tea’s benefits on female reproductive disorders, including polycystic ovary syndrome (PCOS), endometriosis and dysmenorrhea, remains scarce. Thus, this review summarises current knowledge on the beneficial effects of green tea catechins on selected female reproductive disorders. Green tea or its derivative, EGCG, improves endometriosis mainly through anti-angiogenic, anti-fibrotic, anti-proliferative and proapoptotic mechanisms. Moreover, green tea enhances ovulation and reduces cyst formation in PCOS while improving generalised hyperalgesia, and reduces plasma corticosterone levels and uterine contractility in dysmenorrhea. However, information on clinical trials is inadequate for translating excellent findings on green tea benefits in animal endometriosis models. Thus, future clinical intervention studies are needed to provide clear evidence of the green tea benefits with regard to these diseases.     

Species Diversity and Secondary Metabolites of Sarcophyton-Associated Marine Fungi

Soft corals are widely distributed across the globe, especially in the Indo-Pacific region, with Sarcophyton being one of the most abundant genera. To date, there have been 50 species of identified Sarcophyton. These soft corals host a diverse range of marine fungi, which produce chemically diverse, bioactive secondary metabolites as part of their symbiotic nature with the soft coral hosts. The most prolific groups of compounds are terpenoids and indole alkaloids. Annually, there are more bio-active compounds being isolated and characterised. Thus, the importance of the metabolite compilation is very much important for future reference. This paper compiles the diversity of Sarcophyton species and metabolites produced by their associated marine fungi, as well as the bioactivity of these identified compounds. A total of 88 metabolites of structural diversity are highlighted, indicating the huge potential these symbiotic relationships hold for future research.     

Host-guest molecular encapsulation of cucurbit[7]uril with dillapiole congeners using docking simulation and density functional theory approaches

Structural Chemistry - Binding affinity and intermolecular interactions are essential characteristics that could be used to comprehend molecular recognition between molecules in supramolecular...     

Fast detection of sildenafil in adulterated commercial products using differential scanning calorimetry

Adulteration of drugs is a serious issue and can have a great impact on human health. It is mainly done with the intention of boosting the effects of products. For many years, the enforcement officers in Malaysia have had difficulty deciding whether some products should be confiscated as they have not been able to produce fast reliable evidence of adulteration. For that reason, we explored the use of differential scanning calorimetry (DSC) as a potential fast detection method of commercial products marketed in Malaysia that may be adulterated. We confirmed the outcomes qualitatively with high pressure liquid chromatography. DSC was set at a heating rate of 10 °C min^?1 and within a temperature range of 100–250 °C with nitrogen as a purge gas at a flow rate of 20 mL min^?1 to analyse a sildenafil reference standard (RS), sildenafil tablets and sildenafil adulterated commercial products. Four sildenafil adulterated commercial products were analysed. Since the melting point of sildenafil in the mixture tended to shift, the presence of sildenafil in three of these adulterated commercial products was confirmed using the spiking method and was re-analysed using DSC. The re-analysed results indicated that the enthalphy of fusion (?H) and the resolution peak of sildenafil increased accordingly depending upon the amount of spiked sildenafil RS. Apart from these results, the DSC curves also showed different patterns for sildenafil RS and the mixtures. Therefore, we concluded that DSC can potentially be used to detect sildenafil in adulterated commercial products.     

Voltammetric Label‐free Immunosensors for the Diagnosis of Cystic Echinococcosis

Cystic echinococcosis (CE) or hydatid disease is a parasitic infection caused by Echinococcus granulosus. Early serodiagnosis and continuous monitoring of the disease is very important for medical treatment. Here, we report the detecting of both echinococcus antigen and antibody for the diagnosis of hydatid disease using square wave voltammetry (SWV)‐based immunosensors. The gold electrodes were functionalized using cysteamine/phenylene diisothiocyanate linkers and used for the immunosensors fabrication. The hydatid antigen and antibody immunosensors were constructed by the immobilization of either purified rabbit polyclonal antibody or recombinant antigen B (AgB), respectively on the functionalized gold electrodes surfaces. The detection in both cases was achieved by following the change in the SWV reduction peak current of the ferro/ferricyanide redox couple upon antibody or antigen binding. These immunosensors enabled the detection of echinococcus antigen and antibody within a concentration range of 1 pg.mL^?1 to 1 μg.mL^?1 with detection limits of 0.4 pg.mL^?1 and 0.3 pg.mL^?1, respectively. A preliminary application of the developed immunosensor was performed in spiked serum sample showing good recovery percentages ranging from 102 to 110 % for both hydatid antibody and antigen detection. This easy‐to‐use, sensitive, and low cost quantitative method holds great promise for the early diagnosis of hydatid disease and thus, better managements and treatment outcomes.     

Fabrication and characterization of a novel wound scaffold based on polyurethane added with Channa striatus for wound dressing applications

Abstract

Wound healing is a complex process and it involves restoration of damaged skin tissues. Several wound dressings comprising naturally made substances are constantly investigated to assist wound healing. In this research, a new wound dressing based on polyurethane (PU) supplemented with essence of Channa striatus (CS) fish oil was made by electrospinning. Morphological study depicted the reduction in fiber diameter than PU with the addition of fish oil (0.552?±?0.109?μm for 8:1 v/v% and 0.519?±?0.196?μm 7:2 v/v%) than the pristine PU (0.971?±?0.205?µm). Fourier transform infrared spectroscopy (FTIR) analysis revealed the presence of fish oil in the composite as identified through increasing peak intensity. Fish oil resulted in the hydrophilic behavior (88?±?3 (8:1 v/v) and 70?±?6 (7:2 v/v)) as revealed in the contact angle analysis. Thermal gravimetric analysis (TGA) showed the superior thermal behavior of the wound dressing patch compared to the PU. Atomic force microscopy (AFM) analysis insinuated a decrease in the surface roughness of the pristine polyurethane with the added fish oil. Coagulation assays signified the delay in the blood clotting time portraying its anti-thrombogenic behavior. Hemolytic assay revealed the less toxic nature of the developed nanocomposites with the red blood cells (RBC’s) depicting its safety with blood. Hence, polyurethane nanofibers supplemented with fish oil made them as deserving candidates for wound dressing application.