Decalepis hamiltonii roots boost antioxidant status of rat liver and brain

BACKGROUND: Roots of Decalepis hamiltonii are traditionally consumed as pickles and juice for their health benefits. We have earlier demonstrated the antioxidant property of the root extract and identified the constituent antioxidant molecules. RESULTS: This paper reports the effect of multiple‐dose (7, 15, and 30 days) treatment of Decalepis hamiltonii aqueous root extract (DHA) (50 and 100 mg kg^?1 body weight) on the antioxidant profile of rat liver and brain. Activities of the antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), and glutathione‐S‐transferase (GST) were increased and glutathione content was elevated in both liver and brain, apart from reduction in the basal level of lipid peroxidation. DHA induced stronger antioxidant boost in brain by increasing the activities of SOD, CAT, and GPx compared to liver. CONCLUSION: As failure to grapple with oxidative stress is an important factor in the etiology of several diseases, DHA's effects on improvement of antioxidant status could provide a scientific justification for the health‐promoting properties attributed to it. Copyright © 2009 Society of Chemical Industry     

Enzyme-Assisted Process for Production of Superior Quality Vanilla Extracts from Green Vanilla Pods Using Tea Leaf Enzymes

Vanilla planifolia Andrews is a perennial tropical vine and is an orchid grown for its pleasant flavor. There is an increasing trend world over for using natural flavors. Vanilla being an important food flavoring ingredient, the demand for natural vanilla extract is increasing. Hence, the aim of the present study was to prepare vanilla extract from green beans without going through the elaborate and time-consuming conventional curing process. Vanilla beans after size reduction were mixed in a suitable proportion with tea leaf enzyme extract (TLEE) and incubated to facilitate action of enzymes on vanilla flavor precursors. The beans mix was squeezed, and the filtrate was treated with ethanol to extract the vanilla flavor. TLEE-treated extracts had higher vanillin content (4.2%) compared to Viscozyme extract (2.4%). Also, it had higher intensity of vanilla flavor, sweet, and floral notes. Further, electronic nose analysis confirmed the discrimination between extracts. It was concluded that the use of TLEE is very much useful to obtain higher yield of vanilla extract and superior quality vanilla flavor, which avoids the traditional laborious and time-consuming curing process.     

Depicting the role of gas-solid interactions on the hydrodynamics of converging pneumatic riser

The understanding of the flow characteristics and effect of gas-solid interactions in pneumatic risers is fundamental to investigate to ensure effective design cost-effective operation. Thus, to understand the effect of gas-solid interactions on the hydrodynamics of newly proposed conversing risers, this study mainly focused on predicting pressure drop in the dilute phase pneumatic conveying system. The experiments were conducted in a converging riser having a convergence angle of 0.2693°. Various solid particles such as sago, black mustard, and alumina have been considered to study the effect of particle sizes and density on the pressure drop. The experimental outcomes indicate that the total pressure drop increases with an increase in the solid density and gas mass flow rate. Moreover, smaller particle sizes are also increased the pressure drop. An empirical correlation is developed for the prediction of total pressure drop ΔP_T in converging pneumatic riser via dimensional analysis. All dependent variables such as particle and air density, drag force, acceleration due to gravity, the mass flow rate of air and particle, the diameter of particle and converging riser, the height of converging riser were considered to develop the empirical correlation. The established relationship is tested, and experimental data have been fitted for its validation. The estimated relative error of less than 0.05 proved the significance of the developed correlation. Hence, it can be stated that the established relationship is useful in studying the effects of various parameters on the pressure drop across the length of the conversing riser.     

Synthesis of ethylene and butyl methacrylate-based copolymer by emulsion polymerization

The emulsion copolymerization of ethylene with butyl methacrylate (BMA) was carried out in an aqueous medium at 60 °C under moderate reaction conditions. The polymer system is well controlled with a linear increase in the molecular weight (M_n) versus ethylene feed pressure and narrow molecular weight distributions (>1.36) were observed throughout the copolymerization reaction. The spectroscopic analyses confirm the presence of acrylate functional as well as methylene group in the synthesized poly(ethylene-co-BMA) copolymer. Morphological behavior of poly(ethylene-co-BMA) has been studied using SEM and TEM analyses. Thermal stability of the copolymers was investigated by thermogravimetric analysis and it was observed that the copolymer is stable up to 380 °C. X-ray diffraction analysis confirmed the amorphous behavior of poly(ethylene-co-BMA). Dynamic light scattering measurement confirms the formation of poly(ethylene-co-BMA) nanoparticles. The particle size of copolymer nanoparticles were in the range of 85–108 nm with low polydispersity indexes (>0.2). The viscous and the elastic property of the copolymer were investigated and established that at high temperature elastic behavior predominant over viscous effect. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47994.     

Solid acid (superacid) catalyzed regioselective adamantylation of substituted benzenes

Adamantylation of substituted benzenes with 1-bromo-adamantane was catalyzed by solid acids including acidic ion exchange and ionomer resins, HY zeolite, sulfated zirconia and supported superacids on HY zeolite and SiO₂. Adamantylation generally takes place in excellent yield giving predominantly para products without formation of byproducts. The reactions did not require the usual workup of Friedel-Crafts reactions as catalysts were simply filtered of. Cross-linked polystyrene resin sulfonic acid (Amberlyst) was found particularly suitable as besides its high catalytic activity, high regioselectivity was observed with almost exclusive formation ofp-adamantylated benzenes. AMI, PM3 and MNDO semiempirical calculations of heats of formation showed that of all regioisomers, the para isomer is the most stable. The temperature dependence of adamantylation was also investigated allowing the optimization ofp-substituted product in high yield and excellent selectivity. Lack of isomerization of 1-p-tolyla-damantane using solid (Amberlyst, Nafion-H) and liquid acids (neat and modified trifluoromethanesulfonic acid) indicates absence of product isomerization, while the intramolecular rearrangement of the intermediate arenium complex is still possible.Catalysis by solid superacids, Part 30. For part 29, see ref.[1A].     

Simulation of population balance model-based particulate processes via parallel and distributed computing

Population Balance Models (PBMs), a class of integro partial differential equations, are utilized for simulating dynamics of numerous particulate systems. PBMs describe the time evolutions and distributions of many particulate processes and their efficient and quick simulation are critical for enhanced process control and optimization, especially for real-time applications. However, their intensive computational resource requirement is largely a prohibitive factor in the utility of PBMs for control and optimization. This paper describes how distributed computing systems may be leveraged to execute PBM-based simulations thus achieving time savings, using MATLAB's Distributed Computing Toolbox. A parallel computing algorithm was developed for a three dimensional and four dimensional population balance model with built-in constructs such as SPMD that ran efficiently on a cluster of two quad-core machines linked via a gigabit ethernet cable. Speedup of 6.2 and 5.7 times were achieved with 8 workers, over an un-parallelized code, for a 3 and 4 dimensional PBM respectively. Evaluations on work efficiency and scalability further affirm the algorithms’ respectable performance on larger clusters despite significant memory transfer overheads.     

Impact of electrically formed interfacial layer and improved memory characteristics of IrOx/high-κx/W structures containing AlOx,GdOx, HfOx,and TaOx switching materials

Improved switching characteristics were obtained from high-κ oxides AlO_x, GdO_x, HfO_x, and TaO_x in IrO_x/high-κ_x/W structures because of a layer that formed at the IrO_x/high-κ_x interface under external positive bias. The surface roughness and morphology of the bottom electrode in these devices were observed by atomic force microscopy. Device size was investigated using high-resolution transmission electron microscopy. More than 100 repeatable consecutive switching cycles were observed for positive-formatted memory devices compared with that of the negative-formatted devices (only five unstable cycles) because it contained an electrically formed interfacial layer that controlled ‘SET/RESET’ current overshoot. This phenomenon was independent of the switching material in the device. The electrically formed oxygen-rich interfacial layer at the IrO_x/high-κ_x interface improved switching in both via-hole and cross-point structures. The switching mechanism was attributed to filamentary conduction and oxygen ion migration. Using the positive-formatted design approach, cross-point memory in an IrO_x/AlO_x/W structure was fabricated. This cross-point memory exhibited forming-free, uniform switching for >1,000 consecutive dc cycles with a small voltage/current operation of ±2 V/200 μA and high yield of >95% switchable with a large resistance ratio of >100. These properties make this cross-point memory particularly promising for high-density applications. Furthermore, this memory device also showed multilevel capability with a switching current as low as 10 μA and a RESET current of 137 μA, good pulse read endurance of each level (>10⁵ cycles), and data retention of >10⁴ s at a low current compliance of 50 μA at 85°C. Our improvement of the switching characteristics of this resistive memory device will aid in the design of memory stacks for practical applications.     

Low-Temperature Sintering of La(Ca)CrO3 Powder Prepared through the Combustion Process

Ultrafine La(Ca)CrO₃ (LCC) powder was prepared through the glycine–nitrate gel combustion process. It was shown for the first time that the use of relatively inexpensive CrO₃ as a starting material for chromium has potential for the bulk preparation of sinter-active LCC powder. As-prepared powder, when calcined at 700°C, resulted in LCC along with a small amount of CaCrO₄. The calcined powder was found to be composed of soft agglomerates with a particle size of ≈70–290 nm. The cold pressing and sintering of the calcined powder at 1200°C resulted in the mono-phasic La_0.7Ca_0.3CrO₃ with density ≈98% of its theoretical value. This is the lowest sintering temperature ever reported for La_0.7Ca_0.3CrO₃. The conductivity of the sintered La_0.7Ca_0.3CrO₃ at 1000°C was found to be ≈57 S/cm in air. The sintering and electrical behavior achieved for La_0.7Ca_0.3CrO₃ may find application as an interconnect material for high-temperature solid oxide fuel cells if problems with chemical expansion and poor conductivity in fuel can be overcome.     

Modification of LLDPE using esterified styrene maleic anhydride copolymer: Study of its properties and environmental degradability

Linear low‐density polyethylene (LLDPE) was blended with decanol‐esterified styrene maleic anhydride copolymer (MDESMA) with an aim to enhance the environmental degradability of polyethylenes. Styrene‐maleic anhydride copolymer (SMA) was synthesized by precipitation polymerization, using benzoyl peroxide (BPO) as initiator. SMA was esterified with a long‐chain monoalcohol, n‐decanol, using methyl ethyl ketone (MEK) as solvent at 80°C to obtain monoesterified styrene‐maleic anhydride (MDESMA). Fourier transform infrared (FTIR) spectroscopy, differential scanning calorimeter (DSC), and thermogravimetric analysis (TGA) were performed to characterize SMA and MDESMA. IR spectra of MDESMA showed a decrease in intensity of peak responsible for carbonyl absorption of a five‐membered ring anhydride group along with broadening of carboxyl O? H stretching peak. TGA showed two‐stage degradation for SMA and MDESMA. LLDPE was blended with MDESMA in single‐screw extruder and blends were characterized thermally by DSC and TGA. A single endothermic melting peak of LLDPE/MDESMA blend was observed. Films of the blends, formed by compression molding, showed an increase in modulus of elasticity but a decrease in elongation at break with increasing concentration of MDESMA. LLDPE/MDESMA blend compositions when kept in phosphate/citric acid buffer solution (pH ～ 8) showed initial weight gain because of water absorption and subsequently loss in weight due to dissolution of soluble component of blends. Film samples of blends kept for soil burial also showed similar behavior. Contact‐angle measurement of film samples of the blends showed an increase in value on soil burial, indicating degradation/dissolution of MDESMA. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 102–108, 2004