Perspectives on Inhibiting β‐Amyloid Aggregation through Structure‐Based Drug Design

Targeting β‐amyloid (Aβ) remains the most desired strategy in Alzheimer’s disease (AD) drug discovery research. Many peptides that specifically target Aβ aggregates are known, encompassing efforts from both industrial and academic research settings. However, in clinical terms, not much success has been gained with peptide research; in turn, small drug‐like molecules are already globally recognized as showing promise as an alternate approach. Aβ aggregation inhibitors are the most important part of the multifunctional drug design regimen for treating AD. Unfortunately, rational drug design approaches with small molecules are still in the initial stages. Herein we highlight, update, and elaborate on the structural anatomy of Aβ and known Aβ aggregation inhibitors in hopes of helping to optimize their use in structure‐based drug design approaches toward inhibitors with greater specificity. Furthermore, we present the first review of efforts to target a previously uncharacterized region of acetylcholinesterase: the N‐terminal 7–20 sub‐region, which was experimentally elucidated to participate in Aβ aggregation and deposition.     

Synergistic Effects of Carbon Fillers of Phenolic Resin Based Composite Bipolar Plates on the Performance of PEM Fuel Cell

The most essential and costly component of polymer electrolyte membrane fuel cells is the bipolar plate. The production of suitable composite bipolar plates for polymer electrolyte membrane fuel cell with good mechanical properties and high electrical conductivity is scientifically and technically very challenging. This paper reports the development of composite bipolar plates using exfoliated graphite, carbon black, and graphite powder in resole‐typed phenol formaldehyde. The exfoliated graphite with maximum exfoliated volume of 570 ± 10 mL g⁻¹ used in this study was prepared by microwave irradiation of chemically intercalated natural flake graphite in a few minutes. The composite plates were prepared by varying exfoliated graphite content from 10 to 35 wt.% in phenolic resin along with fixed weight percentage of carbon black (5 wt.%) and graphite powder (3 wt.%) by compression molding. The composite plates with filler weight percentage of 35/5/3/exfoliated graphite/carbon black/graphite powder offer in‐plane and trough‐plane electrical conductivities of 374.42 and 97.32 S cm⁻¹, bulk density 1.58 g cm⁻³, compressive strength 70.43 MPa, flexural strength 61.82 MPa, storage modulus 10.25 GPa, microhardness 73.23 HV and water absorption 0.22%. Further, I–V characteristics notify that exfoliated graphite/carbon black/graphite powder/resin composite bipolar plates in unit fuel cell shows better cell performance compared exfoliated graphite/resin composite bipolar plates. The composite plates own desired mechanical properties with low bulk density, high electrical conductivity, and good thermal stability as per the U.S. department of energy targets at low filler concentration and can be used as bipolar plates for proton exchange membrane fuel cells.     

Dynamic vulcanization of polyethylene‐based thermoplastic elastomer blends

In this investigation, the effects of blending with ethylene–propylene–diene terpolymer and subsequent dynamic curing with sulfur on the macromolecular structure and properties of pure low‐density polyethylene and high‐density polyethylene were studied. The crosslinking efficiency of polyethylene‐based ethylene–propylene–diene terpolymer blends upon dynamic curing was assessed with torque and gel content measurements. The curing of dispersed ethylene–propylene–diene terpolymer in a polyethylene matrix improved both the mechanical and thermomechanical properties as a result of the formation of a crosslink structure in the rubber phase. In view of the electrical applications of this cured blend material, the volume resistivity was measured. The thermal stability of vulcanized polyethylene/ethylene–propylene–diene terpolymer blends was found to be superior to that of unvulcanized blends. In scanning electron microscopy analysis, good interface bonding between the polyethylene matrix and dispersed ethylene–propylene–diene terpolymer was observed for the cured blends. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Thermostable and flame retardant Mesua ferrea L. seed oil based non-halogenated epoxy resin/clay nanocomposites

Bio-based polymer nanocomposites have a unique niche of their own in the domain of green technology. A bio-based sulfone epoxy resin (BPSE) has been synthesized from the monoglyceride of Mesua ferrea L. seed oil, bis(4-hydroxyphenyl) sulfone, bisphenol-A and epichlorohydrin. The formation of resin was confirmed by the determination of viscosity, epoxy equivalent, etc. and the structure was elucidated from FTIR and ¹H NMR spectroscopies. This resin was used as the matrix for the preparation of epoxy/clay nanocomposites by ex situ technique using different doses of organo nano-clay (1, 2.5 and 5%, w/w). XRD, TEM, SEM, FTIR and rheological studies confirmed the formation of nanocomposites with partial exfoliated structure of the nano-clay. The study demonstrated that the tensile strength enhanced from 4 to 11.4 MPa, scratch hardness improved by two-fold, gloss value increased by 20 units, adhesive strength improved by two-fold and thermal stability improved by 19 °C on incorporation of 5 wt% of nano-clay with respect to the pristine polymer. The limiting oxygen index value and UL94 test indicated improvement of flame retardancy of the nanocomposites. The results exhibit the potentiality of these bio-based epoxy/clay nanocomposites for multifaceted advanced applications.     

Shelf-Life Extension of Fresh Ginger (Zingiberofficinale) by Gamma Irradiation

ABSTRACT: Gamma irradiation was found to extend the shelf life of farm fresh ginger. A 5-kGy radiation dose and 10 °C storage temperature were found to keep peeled ginger samples microbe free and acceptable until 70 d of storage, whereas nonirradiated (control) peeled ginger spoiled within 40 d under similar storage conditions. The decrease in 6-gingerol, the compound responsible for the pungency of ginger, was found to be insignificant after irradiation.     

Modification of Free Volume in Epoxy Adhesive Formulations

Additives are described which modify the free volume available for segmental motion in epoxy adhesives. Such a mechanism can produce an increase in the tensile modulus of conventional epoxy-amine systems of>60% (e.g. to>4.1 GPa) and in tensile strength of>50% (e.g. to 125 MPa), while also producing a ductile mode of failure (stress-strain curve has negative slope before failure). At low strains, a reduction in free volume hinders polymer segmental motion and so increases the modulus. However, these materials also exhibit a very low Poisson's ratio and strains of ca. 5% cause a sufficient increase in free volume that ductile failure can occur. Improvements in low temperature cure properties (e.g. 118 MPa tensile strength at 60°C cure) together with reductions in the coefficient of thermal expansion and water uptake are also reported. These improvements in bulk adhesive properties are shown to translate into improved adhesive joint performance.     

An improved vertical-axis water-current turbine incorporating a channelling device

Water-Current Turbines (WCTs) are non-polluting electricity generation plants that harness the kinetic energy of natural water courses, using several kinds of rotors. At the School of Engineering of the University of Buenos Aires, researchers are developing a WCT whose particular characteristics improve technical and economic performance. A channelling device, integrated into the flotation system, is used to modify flow conditions in the neighbourhood of the rotor. This system was developed from theoretical modelling and small-scale model testing in a hydrodynamic test canal. The principal advantages of this kind of machine include reduced need for fixed civil works, ease of transport and relocation and autonomous, self-regulated operation, and it is expected to be a low-cost and long-lifetime system.     

Locking-free compressible quadrilateral finite elements: Poisson’s ratio-dependent vector interpolants

In any high-quality viscoplastic calculation, the objectivity related to shape and constitutive parameter indifference is desirable, especially when a continuous deformation into concavity is tracked. In the physical x?y frame, quadratic displacement vectors—explicitly coupled via Poisson’s ratio—encompass bar and Euler–Bernoulli beam modes. Analytically, the unique set of shape functions yields nodal loads and the element stiffness matrix from its area and the first and second area moments. Closed-form Mathematica results exhibit full compliance with all requirements of Iron’s patch tests.     

The electrical delivery of a sublimable II–VI compound by vapor transport in carbon nanotubes

Progress in the field of femtogram (10⁻¹⁵ g) mass delivery relies on finding dependable transport vehicles and uncomplicated methods to tailor the deposition of active substances. Here, current-conductive containers consisting of turbostratic carbon nanotubes were used to store a light-emitting ternary alloy and guide its delivery on demand. We found that the electrically-activated delivery process of this sublimable compound, performed inside a transmission electron microscope, was highly dependent on factors such as the substrate type and current injection mode. Furthermore, our observations suggest that the alleged “missing matter” problem is not solely due to surface migration. Besides extending the field of electrical delivery to the realm of functional materials, the extrusion and mass transport of a sublimable II–VI compound demonstrates that it is possible to guide vapor migration using a carbon nanotube support.