Preparation of Mn2+-Cu+ co-doped P2O5–ZnO–Al2O3 glasses and their red fluorescence properties

To make a Mn²⁺-doped red glass phosphor that can be excited with ultraviolet (UV) light of light-emitting diodes (LEDs), 60P₂O₅-35ZnO-5Al₂O₃-8MnO-xCu₂O glasses (x = 0-1.00) were prepared by a melt-quenching method at 1200-1400°C for 30-180 minutes in atmospheric air, and the redox of Mn and Cu as well as fluorescence properties were investigated. The Mn²⁺ ion was not reduced and oxidized in the melting, quenching, and annealing processes. The valence of Cu in the glasses changed in the order of 0, 1+, and 2+ with the increase in the amount of Cu₂O and in the melting temperature and time. In this study, a 60P₂O₅-35ZnO-5Al₂O₃-8MnO-0.10Cu₂O glass melted at 1250°C for 90 minutes, having the highest Cu⁺ concentration, showed the strongest Mn²⁺ red fluorescence under the UV light at 275 nm. This strong Mn²⁺ red fluorescence has been caused by the energy transfer from excited Cu⁺ ions to Mn²⁺ ions.     

Chemo-enzymatic synthesis and properties of novel optically active cationics containing carbonate linkages

Novel optically active carbonate-type cationics were designed and synthesized via a green method. A series of n-alkyl N,N-dimethylaminoalkyl carbonates was prepared via a two-step successive carbonate exchange reaction of diphenyl carbonate with 1-alkanol followed by the reaction of the optically active or racemic amino alcohol in the presence of triethylamine. The quaternarization of the N,N-dimethylamino group was carried out using methyl iodide. Furthermore, optically active cationics were prepared by the lipase-catalyzed enantioselective hydrolysis of the racemic cationics. Carbonate-type cationics having an isopropylene linkage showed high hydrolytic stability. They exhibited surfactant properties similar to those of the corresponding racemic cationics. Although no significant differences in the antimicrobial activities were observed owing to the stereochemistry of the cationics, the biodegradability was strongly influenced by the stereochemistry. Some optically active cationics were rapidly biodegraded by activated sludge.     

Preparation of TiO2 thin films using octadecylamine Langmuir-Blodgett films and evaluation of their photocatalytic activity

A study was conducted to demonstrate that nanometer-thick titanium dioxide (TiO(2)) thin films could be prepared by the hydrolysis of titanium potassium oxalate using octadecylamine (ODA) Langmuir-Blodgett (LB) films as templates. The amount of TiO(2) generated in the LB film was found to be proportional to the number of deposited ODA layers, which enables precise control of the TiO(2) film thickness. After heat treatment of the LB films at 300-600°C, the photocatalytic activities of the resulting TiO(2) films were determined from the decomposition of stearic acid cast films when irradiated with UV light for different time periods. Higher photocatalytic activity was observed in TiO(2) films heat treated at lower temperatures.     

Cancer chemopreventive ability of conjugated linolenic acids

Conjugated fatty acids (CFA) have received increased interest because of their beneficial effects on human health, including preventing cancer development. Conjugated linoleic acids (CLA) are such CFA, and have been reviewed extensively for their multiple biological activities. In contrast to other types of CFAs including CLA that are found at low concentrations (less than 1%) in natural products, conjugated linolenic acids (CLN) are the only CFAs that occur in higher quantities in natural products. Some plant seeds contain a considerably high concentration of CLN (30 to 70 wt% lipid). Our research group has screened CLN from different plant seed oils to determine their cancer chemopreventive ability. This review describes the physiological functions of CLN isomers that occur in certain plant seeds. CLN are able to induce apoptosis through decrease of Bcl-2 protein in certain human cancer cell lines, increase expression of peroxisome proliferator-activated receptor (PPAR)-γ, and up-regulate gene expression of p53. Findings in our preclinical animal studies have indicated that feeding with CLN resulted in inhibition of colorectal tumorigenesis through modulation of apoptosis and expression of PPARγ and p53. In this review, we summarize chemopreventive efficacy of CLN against cancer development, especially colorectal cancer.     

Preparation of polyynes by liquid-phase laser ablation using different irradiation target materials and solvents

Polyynes were prepared from pellets of a perylene derivative, 3,4,9,10-perylene tetracarboxylic dianhydride (PTCDA), and graphite by liquid-phase laser ablation, using solvents of methanol, ethanol, 1-propanol, 1-butanol, t-butyl alcohol, n-hexane, and decalin. The amounts of polyynes produced from PTCDA strongly depended on the polarity of the solvent, while those from graphite did not. Polar functional groups of acid-anhydride side chains in PTCDA are believed to influence the amounts of C₂ radicals produced by laser ablation. The long-chain polyyne C₂₈H₂ was detected in a chromatogram of a solution obtained from a graphite pellet and solvent decalin.     

Basics of analytical methods used for the investigation of interaction mechanism between cements and superplasticizers

In order to better understand the interactions between cements and superplasticizers (high-range water reducers), various analytical methods have traditionally been applied, but some of these methods can introduce significant errors. In this paper the fundamental interaction mechanisms are reviewed and appropriate methods and sample preparation conditions are explained in detail. For superplasticizer adsorption measurements, analysis by size exclusion chromatography is useful in order to avoid the effect of other organic compounds released from cement by the action of the superplasticizer. For BET specific surface area measurements it is important to avoid pre-drying at over 60 °C, as otherwise ettringite can decompose and strongly increase the surface area. In order to evaluate pore solution chemistry correctly the aqueous phase must be extracted without dilution. In addition, the fluidity performance of many cements in superplasticized concretes can be changed simply by passage through a storage silo, for reasons which are not yet understood.     

High-Performance Induction Motor Drive System Using a PWM Inverter

A high-performance speed control system for cage induction motors is described which utilizes a PWM inverter. The effects of primary current coincidence and machine constant variation on system characteristics such as response time, torque precision, and operating noise were investigated. Based on the results obtained, new control methods have been devised; one varies the gain of the current controller in proportion to the primary frequency, and a second compensates for the slip frequency by using the deviation between the flux reference value and the actual value. Effectiveness of the compensation methods was confirmed in tests.     

MiR-7-5p Is Involved in Ferroptosis Signaling and Radioresistance Thru the Generation of ROS in Radioresistant HeLa and SAS Cell Lines

In cancer therapy, radioresistance or chemoresistance cells are major problems. We established clinically relevant radioresistant (CRR) cells that can survive over 30 days after 2 Gy/day X-ray exposures. These cells also show resistance to anticancer agents and hydrogen peroxide (H₂O₂). We have previously demonstrated that all the CRR cells examined had up-regulated miR-7-5p and after miR-7-5p knockdown, they lost radioresistance. However, the mechanism of losing radioresistance remains to be elucidated. Therefore, we investigated the role of miR-7-5p in radioresistance by knockdown of miR-7-5p using CRR cells. As a result, knockdown of miR-7-5p increased reactive oxygen species (ROS), mitochondrial membrane potential, and intracellular Fe²⁺ amount. Furthermore, miR-7-5p knockdown results in the down-regulation of the iron storage gene expression such as ferritin, up-regulation of the ferroptosis marker ALOX12 gene expression, and increases of Liperfluo amount. H₂O₂ treatment after ALOX12 overexpression led to the enhancement of intracellular H₂O₂ amount and lipid peroxidation. By contrast, miR-7-5p knockdown seemed not to be involved in COX-2 and glycolysis signaling but affected the morphology of CRR cells. These results indicate that miR-7-5p control radioresistance via ROS generation that leads to ferroptosis.     

Defining Dry Eye from a Clinical Perspective

Over the past decades, the number of patients with dry eye disease (DED) has increased dramatically. The incidence of DED is higher in Asia than in Europe and North America, suggesting the involvement of cultural or racial factors in DED etiology. Although many definitions of DED have been used, discrepancies exist between the various definitions of dry eye disease (DED) used across the globe. This article presents a clinical consensus on the definition of DED, as formulated in four meetings with global DED experts. The proposed new definition is as follows: “Dry eye is a multifactorial disease characterized by a persistently unstable and/or deficient tear film (TF) causing discomfort and/or visual impairment, accompanied by variable degrees of ocular surface epitheliopathy, inflammation and neurosensory abnormalities.” The key criteria for the diagnosis of DED are unstable TF, inflammation, ocular discomfort and visual impairment. This definition also recommends the assessment of ocular surface epitheliopathy and neurosensory abnormalities in each patient with suspected DED. It is easily applicable in clinical practice and should help practitioners diagnose DED consistently. This consensus definition of DED should also help to guide research and clinical trials that, to date, have been hampered by the lack of an established surrogate endpoint.