Alignment control of liquid crystals in a 1.0‐μm‐pitch spatial light modulator by lattice‐shaped dielectric wall structure

We achieved uniform liquid crystal (LC) alignment in lattice‐shaped dielectric walls 1 μm in pitch; this is a prerequisite when driving the individual pixels of spatial light modulators, facilitating the development of practical electronic holographic displays with a wide field of view. In lattice‐shaped dielectric walls, LC alignment becomes unstable, particularly on the bottom and the walls; the LC directors tend to align parallel to the walls. To overcome this problem, we created lattice‐shaped walls featuring partition plates that allow uniform LC alignment. When the plates confine LCs to small regions exhibiting spatial anisotropy, the LC elastic effect and wall anchoring forces align the LC directors parallel to the long anisotropic axis. We found that pixels 0.5 μm × 1.0 μm in pitch formed if the partition plates were sufficiently thick to allow shielding of electric field leakage.     

Synthesis of zirconia sphere particles based on gelation of sodium alginate

Zirconia sphere particles were synthesized through the gelation process of Na-alginate, and cermet (ZrO₂-Mo) pellets were fabricated under several conditions. In this process, a zirconia slurry was prepared by mixing oxide powders (ZrO₂, Y₂O₃, Er₂O₃, CeO₂), distilled water and Na-alginate, and subsequently dropped into CaCl₂ solution. As a result, zirconia sphere particles coated with a gelled film were synthesized. The slurry density (zirconia content in slurry) of 30-64 wt.% and Na-alginate concentration of a few% were good for gelation for up to 10 wt.% CaCl₂ solution. Sphere particles with smaller diameter were obtained by dropping slurry with a mechanical vibration. The prolongation of the ball milling time for mixture of oxide powders was effective to increase the sintered density of zirconia sphere particles, especially for higher CeO₂ concentration. The dense cermet pellets were fabricated for max. 50% volume ratio of zirconia phase for Mo matrix using zirconia particles covered with Mo powder by a rotating granulation method.     

Minimization of Friction at Various Speeds Using Autonomous Viscosity Control of Nematic Liquid Crystal

To demonstrate the concept of the smart lubrication system using liquid crystal (LC) lubricant proposed by Nakano (Tribol Lett 14:17–24, 2003), the following three types of tests were performed: (1) film thickness measurements in pure rolling contacts, (2) friction coefficient measurements in rolling–sliding contacts, and (3) molecular orientation measurements in stationary cells. In all of these types of tests, a nematic LC [4-pentyl-4′-cyanobiphenyl (5CB)] and a carboxylic acid [hexadecanoic acid (HDA)] were used as the base fluid and the additive, respectively. The results of these tests confirm the following mechanism. First, surface films of the HDA additive that spontaneously adsorb onto contact surfaces induce surface anchoring, which has the effect of making 5CB molecules align themselves perpendicular to the surfaces, competing with the flow alignment of 5CB molecules and inducing an increase in the apparent viscosity of 5CB with decreasing entrainment speed. This increase in the apparent viscosity generates a constant friction coefficient region in the Stribeck curve on the left side of the minimum friction coefficient point, resulting in the minimization of friction at various speeds.     

Fine-tuned,molecular-composite,organosilica membranes for highly efficient propylene/propane separation via suitable pore size

Fine-tuned, molecular-composite, organosilica membranes were fabricated via the co-condensation of organosilica precursors bis(triethoxysilyl)acetylene (BTESA) and bis(triethoxysilyl)benzene (BTESB). Fourier transform infrared and UV–vis spectra confirmed the co-condensation behaviors of BTESA and BTESB. The evolution of the network structure indicated that the incorporated BTESB decreased the membrane pore size, which was determined by a modified gas translation model according to the steric effect of the phenyl groups. The incorporation of BTESB to BTESA finely tuned the membrane structure and endowed the resultant composite membrane with improved separation properties. The BTESAB 9:1 membrane (molar ratio of BTESA/BTESB was 9:1) exhibited high C₃H₆ permeance at 4.5 × 10⁻⁸ mol m⁻² s⁻¹ Pa⁻¹ and a C₃H₆/C₃H₈ permeance ratio of 33 at 50°C. One of the most important developments of this study involved clearly defining the relationship between membrane pore size and C₃H₆/C₃H₈ separation performance for organosilica membranes in single and binary separation systems.     

Cell interaction study of amyloid by using luminescent conjugated polythiophene: implication that amyloid cytotoxicity is correlated with prolonged cellular binding

Needles and noodles: Studying amyloid toxicity is important for understanding protein misfolding diseases. Using a luminescent conjugated polythiophene, we found that cell binding of nontoxic filamentous amyloids of insulin and β2-microglobulin was less efficient than that of toxic fibrillar amyloids; this suggests a correlation between amyloid toxicity and cell binding.     

Morphology‐dependent electrocatalytic activity of nanostructured Pt/C particles from hybrid aerosol–colloid process

An optimum nanostructure and pore size of catalyst supports is very important in achieving high catalytic performances. In this instance, we evaluated the effects of various carbon nanostructures on the catalytic performances of carbon‐supported platinum (Pt/C) electrocatalysts experimentally and numerically. The Pt/C catalysts were prepared using a hybrid method involving the preparation of dense, hollow, and porous nanostructured carbon particle via aerosol spray pyrolysis followed by microwave‐assisted Pt deposition. Electrochemical characterization of the catalysts showed that the porous Pt/C catalyst gave the best performance; its electrochemical surface area was much higher, more than twice than those of hollow or dense Pt/C. The effects of pore size on electrocatalysis were also studied. The results showed the importance of a balance between mesopores and macropores for effective catalysis with a high charge transfer rate. A fluid flow model showed that good oxygen transport contributed to the catalytic activity. © 2015 American Institute of Chemical Engineers AIChE J, 62: 440–450, 2016     

Dynamic mechanical properties of photopolymerizable poly(vinyl alcohol)–acrylate monomer blends

Dynamic mechanical properties of photopolymerizable poly(vinyl alcohol) (PVA)–monoacrylate blends were investigated by measuring dynamic shear modulus G′ and loss tangent, tan δ. The dynamic mechanical properties of the blends before being exposed to UV irradiation were governed by the weight percent of the monomers which act as plasticizers. On the other hand, the UV-irradiated blends seemed to be typical two-phase materials since they revealed two tan δ maxima whose positions were independent of the monomer content. Those two maxima were assigned to PVA and photopolymerized acrylates with reference to the dynamic mechanical data of PVA and a PVA-polyacrylamide polyblend. Those dynamic mechanical data suggested that insolubilization of the blend type photopolymers should be caused by a decrease in solubility due to graft polymerization of acrylate monomers onto PVA.     

Protective Role of Glutathione in the Hippocampus after Brain Ischemia

Stroke is a major cause of death worldwide, leading to serious disability. Post-ischemic injury, especially in the cerebral ischemia-prone hippocampus, is a serious problem, as it contributes to vascular dementia. Many studies have shown that in the hippocampus, ischemia/reperfusion induces neuronal death through oxidative stress and neuronal zinc (Zn²⁺) dyshomeostasis. Glutathione (GSH) plays an important role in protecting neurons against oxidative stress as a major intracellular antioxidant. In addition, the thiol group of GSH can function as a principal Zn²⁺ chelator for the maintenance of Zn²⁺ homeostasis in neurons. These lines of evidence suggest that neuronal GSH levels could be a key factor in post-stroke neuronal survival. In neurons, excitatory amino acid carrier 1 (EAAC1) is involved in the influx of cysteine, and intracellular cysteine is the rate-limiting substrate for the synthesis of GSH. Recently, several studies have indicated that cysteine uptake through EAAC1 suppresses ischemia-induced neuronal death via the promotion of hippocampal GSH synthesis in ischemic animal models. In this article, we aimed to review and describe the role of GSH in hippocampal neuroprotection after ischemia/reperfusion, focusing on EAAC1.     

Enhanced Development of Azoxymethane-Induced Colonic Preneoplastic Lesions in Hypertensive Rats

Metabolic syndrome is associated with an increased risk of colorectal cancer. This study investigated the impact of hypertension, a component of metabolic syndrome, on azoxymethane (AOM)-induced colorectal carcinogenesis using SHRSP/Izm (SHRSP) non-diabetic/hypertensive rats and SHRSP.Z-Lepr^fa/IzmDmcr (SHRSP-ZF) diabetic/hypertensive rats. Male 6-week-old SHRSP, SHRSP-ZF, and control non-diabetic/normotensive Wister Kyoto/Izm (WKY) rats were given 2 weekly intraperitoneal injections of AOM (20 mg/kg body weight). Two weeks after the last injection of AOM, the SHRSP and SHRSP-ZF rats became hypertensive compared to the control WKY rats. Serum levels of angiotensin-II, the active product of the renin-angiotensin system, were elevated in both SHRSP and SHRSP-ZF rats, but only the SHRSP-ZF rats developed insulin resistance, dyslipidemia, and hyperleptinemia and exhibited an increase in adipose tissue. The development of AOM-induced colonic preneoplastic lesions and aberrant crypts foci, was significantly accelerated in both SHRSP and SHRSP-ZF hypertensive rats, compared to WKY normotensive rats. Furthermore, induction of oxidative stress and exacerbation of inflammation were observed in the colonic mucosa and systemically in SHRSP and SHRSP-ZF rats. Our findings suggest that hypertension plays a role in the early stage of colorectal carcinogenesis by inducing oxidative stress and chronic inflammation, which might be associated with activation of the renin-angiotensin system.