Halogenated Bis(methoxybenzylidene)‐4‐piperidone Curcuminoids with Improved Anticancer Activity

A series of readily available curcuminoids with a halogenated bis(4‐methoxy/4,5‐dimethoxybenzylidene)‐4‐piperidone structure were prepared and analyzed for their cytotoxic impact on eight human cancer cell lines of five different entities. The known 3,4,5‐trimethoxybenzylidene curcuminoid 2 a and the new bis‐(3‐bromophenyl) and bis‐(3,5‐dibromophenyl) derivatives 3 c and 3 d proved to be more strongly antiproliferative than the known curcuminoid EF24 against six of these cell lines. Compounds 2 a and 3 c caused a distinct increase of reactive oxygen species, which eventually elicited apoptosis in 518A2 melanoma cells. Compound 2 a arrested 518A2 melanoma cells in G₁ phase of the cell cycle and had no effect on the expression of pro‐metastatic matrix metalloproteinases MMP‐2 and MMP‐9, whereas 3 c led to an accumulation of 518A2 cells in the G₂/M phase and to a downregulation of MMP‐2 expression. In addition, treatment with 2 a and 3 c resulted in significant inhibition of colony formation in HCT116 cells. Both 2 a and 3 c showed antiangiogenic activity, for example, by inhibiting the formation of sub‐intestinal veins (SIV) in zebrafish embryos. Compound 3 c was also well tolerated by mice and inhibited the growth of HCT116 colon cancer xenografts.     

A synthesis study of phosphonated PSEBS for high temperature proton exchange membrane fuel cells

A series of novel phosphonated proton exchange membranes has been prepared using poly(styrene‐ethylene/butylene‐styrene) block copolymer (PSEBS) as base material. Phosphonic acid functionalization of the polymer was performed by a simple two‐step process, via chloromethylation of PSEBS followed by phosphonation utilizing the Michaels–Arbuzov reaction. The successful phosphonation of the polymers were characterized by NMR and Fourier transform infrared. The phosphonated ester form of the membranes were obtained by solvent evaporation method and hydrolyzed to get a proton conducting membrane. The membrane properties such as ion exchange capacity, water uptake and proton conductivity at various temperatures were examined for their suitability to be utilized as a high temperature polymer electrolyte. Additionally, the morphology, thermal, and mechanical properties of the synthesized membranes were investigated, using scanning electron microscope, thermogravimetric analysis, and tensile test, respectively. The effective (anhydrous) proton conductivity was studied with respect to various degrees of functionalization. From the studies, the membranes were found to have a comparatively good conductivity and one of the membranes reached the maximum value of 5.81 mS/cm² at 140 °C as measured by impedance analyzer. It was found that the synthesized membranes were mechanically durable, chemically, and thermally stable. Hence, the synthesized phosphonated membranes could be a promising candidate for high temperature polymer electrolyte fuel cell applications. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45954.     

Innovative multi‐processed N‐doped carbon and Fe3O4 cathode for enhanced bioelectro‐Fenton microbial fuel cell performance

A novel bioelectro‐Fenton microbial fuel cell (BEF‐MFC) cathode has been fabricated by modification of electrode using multi‐processing of nitrogen‐doped carbon (NDC)/nano‐Fe₃O₄ method with the aims of cost‐effectiveness, high oxygen reduction reaction (ORR) efficiency, and power performance enhancement. In this study, BEF‐MFC with carbon cloth (CC) cathode pyrolyzed with NDC‐M100/Fe₃O₄ at 700°C achieved higher ORR activity compared with the commercial Pt/C under same operational conditions. It also exhibited excellent crystalline structure according to high‐resolution transmission electron microscope (HRTEM) analysis. Moreover, using NDCN/Fe₃O₄ can facilitate further Fenton‐like reaction for the treatment of wastewater. Chemical oxygen demand (COD) removal efficiency of the reactor was 78% with maximum power density of 1.57 W/m³ in 216 hours. Thus, an innovative multi‐processing method with feasibility for enhanced wastewater treatment and improved power performance of the MFC was investigated. This can be effectively applied in related alternative energy production techniques and bio‐electrochemical systems in the future.     

Dielectric relaxation of binary mixtures of alcohols with acrylic esters

A dielectric relaxation study on alcohol–acrylic ester binary mixtures has been carried out at different concentrations using time domain reflectometry (TDR). The least‐squares fit method has been used to obtain the dielectric parameters (the static dielectric constant ?₀ and the relaxation time τ). By using these parameters, the Bruggeman factor, the Kirkwood correlation factor, and excess inverse relaxation time were determined and discussed to yield information on the molecular structure and dynamics of the mixture. The ?₀ and τ values decreased with an increase in the percent of acrylic ester in alcohol for all the systems. The value of t increased with an increase in chain length of both the alcohol and acrylic ester, whereas the reverse trend is observed for ?₀. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Understanding the structure of the adhesive plaque of Amphibalanus reticulatus

The barnacle, Amphibalanus reticulatus, is a common fouler in the Indian marine waters and is found to attach to a wide variety of natural and man-made surfaces. The shells of the barnacles remain attached to the substrate irrespective of whether the barnacle is alive or dead and details of dried shells are relatively less explored. The dried adhesive plaque of the barnacles attached to polymethylmethacrylate (PMMA) substrates were isolated and subjected to several structural characterization studies like X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The results report the presence of calcite nano-crystallites and amide II groups corresponding to the adhesive protein. The characteristic concentric ring pattern of barnacle base-plate structure, under higher magnification using SEM, appears to be formed of alternate calcite bricks and cement duct openings with an increasing separation distance between adjacent rings. The shear strength studies of barnacles of varying size indicate a direct correspondence to the base-plate diameter.     

Carotenoid composition and retinol equivalent in plants of nutritional and medicinal importance: Efficacy of β-carotene from Chenopodiumalbum in retinol-deficient rats

This study aimed to (1) quantify carotenoids in leafy vegetables and plants of nutritional and medicinal importance, (2) evaluate retinol equivalent (RE) of provitamin-A carotenoids and (3) determine efficacy of β-carotene from Chenopodium album and to compare with retinol formed on feeding to retinol-deficient rats for 3 weeks. β-Carotene and lutein contents (mg/100 g dry weight) ranged from 1.5 to 120 and 11.7 to 185 (leafy greens) and 0.4 to 34.7 and 11.8 to 679 (medicinal plants) whereas, α-carotene ranged from 0.3 to 35.6 (leafy greens) and 0.1 to 15.7 (medicinal plants). RE values (mg%) ranged from 0.4 to 20 and 0.42 to 5.8 in leafy greens and medicinal plants. Efficacy of β-carotene (2400 μg/kg diet) from C. album in retinol-deficient rats revealed a 93.6% rise in plasma retinol levels from 0.53 to 8.4 μM. The plants analysed are a good source of retinol precursors and biologically active lutein; therefore can be exploited to meet carotenoid requirements.     

Dysregulation of microRNA and Intracerebral Hemorrhage: Roles in Neuroinflammation

Intracerebral hemorrhage (ICH) is a major public health problem and devastating subtype of stroke with high morbidity and mortality. Notably, there is no effective treatment for ICH. Neuroinflammation, a pathological hallmark of ICH, contributes to both brain injury and repair and hence, it is regarded as a potential target for therapeutic intervention. Recent studies document that microRNAs, small non-coding RNA molecules, can regulate inflammatory brain response after ICH and are viable molecular targets to alter brain function. Therefore, there is an escalating interest in studying the role of microRNAs in the pathophysiology of ICH. Herein, we provide, for the first time, an overview of the microRNAs that play roles in ICH-induced neuroinflammation and identify the critical knowledge gap in the field, as it would help design future studies.     

Investigation on the development of sturdy bioactive hydrogel beads

Biocatalytic hydrogel beads, which retain higher activity, expand, and contract with changes in pH, having biocompatibility, are developed. Composite spherical beads of chitosan having a diameter of 1–2 mm were prepared by ionic gelation using sodium tripolyphosphate (TPP). Above 3% TPP, the activity of the enzyme decreases. The mechanical strength of the chitosan–TPP beads was further improved by the addition of clay or cassava starch granules. The immobilization of protease (fungal, Aspergillus) was done with glutaraldehyde crosslinking. The chitosan–starch hydrogel beads showed significant increase in firmness and stiffness when compared with chitosan–clay beads. The swelling studies show that the particles expand at pH 1.2 and contract at pH 7.4. The activity retention of the immobilized protease was as high as 70% and exhibited a high pH and lower temperature optima than the free enzyme. Chitosan–starch hydrogel beads exhibited degradation peaks at about 90–110°C in TGA analysis. The biocatalyst beads retained 85% of the original catalytic activity even after eight cycles of repeat use. The freeze‐dried beads has good storage stability and can be used either as artificial bioreactor systems in detergent or in therapeutic formulations © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008