Development of Bigels Based on Stearic Acid–Rice Bran Oil Oleogels and Tamarind Gum Hydrogels for Controlled Delivery Applications

In the last few decades, different types of gels have been widely studied as potential drug delivery carriers. In this paper, we propose the synthesis of an oleogel, a tamarind gum hydrogel, and bigels for applications as drug delivery matrices. The oleogel was prepared by mixing stearic acid and rice bran oil, whereas the hydrogel was prepared by mixing tamarind gum with a hydroethanolic solution. Hydrogel‐in‐oleogel and oleogel‐in‐hydrogel bigels were prepared by mixing the hydrogel and the oleogel. The suitability of the formulations for controlled drug release applications was thoroughly examined using microscopy, Fourier transform infrared (FTIR) spectroscopy, as well as mechanical, electrical, thermal, drug release, and antimicrobial studies. An alteration in the microarchitecture of the bigels is observed when the oleogel and the hydrogel are mixed in varying proportions. The associative interactions within the formulations increase with the increase in the hydrogel content. The bigels exhibit the presence of stearic acid melting endotherm (associated with the oleogel) and water evaporation endotherm (associated with the hydrogel). This study suggests that the hydrogel has lowest bulk resistance compared to the other formulations. The structural breakdown of the bigels is composition‐dependent, and the bulk electrical resistance is mainly governed by the oleogel phase. An increase in the diffusion of the moxifloxacin HCl from the formulations is observed with the increase of the hydrogel proportion, which in turn increases the rate of release of the drug. The proposed formulations also exhibit good antimicrobial efficacy. The analysis of these properties suggests that specific formulations can be tailored by need‐based applications of the drug release rate.     

Development of a novel proton conducting fuel cell based on a Ni‐YSZ support

A new proton conducting fuel cell design based on the BZCYYb electrolyte is studied in this research. In high‐performance YSZ‐based SOFCs, the Ni‐YSZ support plays a key role in providing required electrical properties and robust mechanical behavior. In this study, this well‐established Ni‐YSZ support is used to maintain the proton conducting fuel cell integrity. The cell is in a Ni‐YSZ (375 μm support)/Ni‐BZCYYb (20 μm anode functional layer)/BZCYYb (10 μm electrolyte)/LSCF‐BZCYYb (25 μm cathode) configuration. Maximum power density values of 166, 218, and 285 mW/cm² have been obtained at 600°C, 650°C, and 700°C, respectively. AC impedance spectroscopy results show values of 2.17, 1.23, and 0.76 Ω·cm² at these temperatures where the main resistance contributor above 600°C is ohmic resistance. Very fine NiO and YSZ powders were used to achieve a suitable sintering shrinkage which can enhance the electrolyte sintering. During cosintering of the support and BZCYYb electrolyte layers, the higher shrinkage of the support layer led to compressive stress in the electrolyte, thereby enhancing its densification. The promising results of the current study show that a new generation of proton conducting fuel cells based on the chemically and mechanically robust Ni‐YSZ support can be developed which can improve long‐term performance and reduce fabrication costs of proton conducting fuel cells.     

Facile Suzuki coupling over ortho-metalated palladium(II) complex anchored on 2D-hexagonal mesoporous organosilica

Phenyl functionalized 2D-hexagonal mesoporous silica material has been synthesized by cationic/non-ionic mixed surfactant templating route. The phenyl group of this mesoporous material is further functionalized via nitration and then reduction of that nitro group to amino functionality, followed by Schiff base condensation and heterogenization of a palladium(II) complex, yielded an ortho-metalated palladium(II) complex anchored in a ordered mesoporous silica matrix. This supported metal complex acts as an efficient catalyst in the Suzuki cross-coupling reaction and shows high selectivity for the bi-aryl products.     

Guayule natural rubber composites: impact of fillers on their cure characteristics,dynamic and mechanical behavior

Guayule natural rubber (GNR) is an alternative resource of Hevea natural rubber (HNR) with 99.9% cis content in its 1,4-polyisoprene chemical backbone. In this study, compounds were formulated independently with four different reinforcing fillers such as carbon black (HAF), precipitated silica (VN3), fume silica (FUM) and nanofly ash (NFA) for the advancement of GNR based products. The cure characteristic, dynamic-mechanical performance and mechanical properties of GNR composite were studied with the reinforcing effect of different fillers on GNR. The cure characteristic results demonstrated that HAF and FUM silica filled compounds had more processing safety than VN3 and NFA filled compounds. Viscoelastic parameters of the vulcanizates were studied by dynamic mechanical analysis to estimate the glass transition characteristics and dynamic behavior. The higher storage modulus of FUM silica vulcanizate was an indication of superior filler reinforcing nature and improved rolling resistance than other filled systems. Additionally, HRTEM analysis also proved the better filler dispersion ability of FUM silica in GNR matrix. The mechanical properties were studied with a variation of each filler loading of 8, 16, and 32 phr in GNR vulcanizates. The tensile strength of each filled system increased with an increase of filler content from 8 to 32 phr. In comparison, FUM silica GNR vulcanizates exhibited better mechanical properties, therefore, it was considered as a better structure-performance composite than those of HAF, VN3 and NFA filled composites.

     

Transcritical CO2 Heat Pump Dryer: Part 2. Validation and Simulation Results

The simulation model of a transcritical CO₂ heat pump dryer presented in Part 1 has been first validated with available experimental data in this part and then used to simulate the heat pump dryer to study the variation of performance parameters such as heating COP, moisture extraction rate, and specific moisture extraction rate. The validation with experimental data shows that the model slightly over predicts the system performance. The possible reasons for the difference between experimental and numerical results are explained. Simulation results show the effect of key operating parameters such as bypass air ratio, re-circulation air ratio, dryer efficiency, ambient condition (temperature and relative humidity), and air mass flow rate. Results show that unlike bypass air ratio and ambient relative humidity, the effect of dryer efficiency, recirculation air ratio, ambient temperature, and air mass flow rate are very significant as far as the system performance is concerned.     

Self-Assembly and Neurotoxicity of β-Amyloid (21–40) Peptide Fragment: The Regulatory Role of GxxxG Motifs

The three GxxxG repeating motifs from the C-terminal region of β-amyloid (Aβ) peptide play a significant role in regulating the aggregation kinetics of the peptide. Mutation of these glycine residues to leucine greatly accelerates the fibrillation process but generates a varied toxicity profile. Using an array of biophysical techniques, we demonstrated the uniqueness of the composite glycine residues in these structural repeats. We used solvent relaxation NMR spectroscopy to investigate the role played by the surrounding water molecules in determining the corresponding aggregation pathway. Notably, the conformational changes induced by Gly³³ and Gly³⁷ mutations result in significantly decreased toxicity in a neuronal cell line. Our results indicate that G³³xxxG³⁷ is the primary motif responsible for Aβ neurotoxicity, hence providing a direct structure–function correlation. Targeting this motif, therefore, can be a promising strategy to prevent neuronal cell death associated with Alzheimer's and other related diseases, such as type II diabetes and Parkinson's.     

Extraction of coals through dilute alkaline hydrolytic treatment at low temperature and ambient pressure

Assam and Talcher (bituminous) coals have been subjected to batch aqueous alkali treatment followed by extraction. It has been shown that alkali treatment increased extractability and reactivity of coal. Use of 1.4% aqueous sodium hydroxide was found to be capable of rendering about 40–50% coal extractable in ethylene diamine in two alkali treatments followed by extractions. Semibatch operation yielded about 26–33% extractable coal, and extraction data were found to be comparable with those obtained in batch degradation via a single alkali treatment. Of the solvents studied, polar and basic solvents were found to be the most effective.     

Positron emission tomography. Tracing how and why it is sosuccessful

PET is one of the most advanced medical imaging systems widely applied to medical research and clinical use. The present PET scanning technique cannot be performed in small animals such as mice. The detector is not optimal with respect to radiotracer sensitivity due to the lack of spatial resolution. (The problem is further exacerbated due to the lack of a computer model and the unknown amount of radiotracers to be administered for viable detection in small animals.) Thus, the authors are working on a feasibility study to show whether present PET scanning systems can be modified to identify active tumor foci in an orthotopic mouse model of human pancreatic cancer. This way the efficacy of selected standard chemotherapy drugs and novel biological agents can be tested. Ultimately, the goal is the development of novel therapeutic agents against human pancreatic cancer