Stochastic homogenization on selfsimilar structures

Stochastic selfsimilar sets and measure have been used extensively to model various physical phenomena. In the following we will use them to generalize the concept of stochastic two-scale convergence. Using this notion the homogenization theory can be developed for stochastic selfsimilar structures. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

State- and water repellency-controllable molecular glass of pillar[5]arenes with fluoroalkyl groups by guest vapors

Molecular glasses are low-molecular-weight organic compounds that are stable in the amorphous state at room temperature. Herein, we report a state- and water repellency-controllable molecular glass by n-alkane guest vapors. We observed that a macrocyclic host compound pillar[5]arene with the C₂F₅ fluoroalkyl groups changes from the crystalline to the amorphous state (molecular glass) by heating above its melting point and then cooling to room temperature. The pillar[5]arene molecular glass shows reversible transitions between amorphous and crystalline states by uptake and release of the n-alkane guest vapors, respectively. Furthermore, the n-alkane guest vapor-induced reversible changes in the water contact angle were also observed: water contact angles increased and then reverted back to the original state by the uptake and release of the n-alkane guest vapors, respectively, along with the changes in the chemical structure and roughness on the surface of the molecular glass. The water repellency of the molecular glass could be controlled by tuning the uptake ratio of the n-alkane guest vapor.

Pillar[5]arenes with C₂F₅ substituents showed reversible amorphous–crystal transitions by uptake and release of n-alkane vapors. The amorphous–crystal transitions triggered macroscopic property change such as water repellency.     

Production of Bioactive Substances to Alleviates Hangover and Ethanol-Induced Liver Damage through Fermentation of Oenanthe javanica Using Lactiplantibacillus plantarum

The purpose of this study is to evaluate the effect of the bioconversion products of Oenanthe javanica extract fermented by Lactiplantibacillus plantarum (OEFL) on relieving hangovers and improving liver function. In addition, the bioactive substance of the OEFL, which alleviates hangover and ethanol-induced liver damage, was identified and its bioactive property was verified through in vivo experiments. In major substances analysis using high-performance liquid chromatography, OEFL produced 9.5-fold higher p-coumaric acid than the O. Javanica extract (OE). In addition, considering that quinic acid, which is not present in the OE, was produced in the OEFL it was confirmed that chlorogenic acid was decomposed into quinic acid by bioconversion. In the in vivo experiment using Sprague-Dawley rats, the OEFL and p-coumaric acid diets reduced blood ethanol, acetaldehyde, GPT, and ALP concentrations, increasing blood albumin concentrations compared to ethanol-administered groups, demonstrating that OEFL and p-coumaric acid, the main substance in the OEFL, improved ethanol-induced liver damage. Furthermore, the OEFL and its main bioactive substance, p-coumaric acid, alleviated liver fibrosis by downregulating TGF-β, SMAD-2, SMAD-4, α-SMA, and upregulating MMP-1. Therefore, OEFL is expected to be used as a functional food or pharmaceutical material as it has been confirmed to effectively relieve hangovers, prevent liver damage, and delay liver fibrosis in ethanol-induced liver damages.     

Pathway Dependence of the Formation and Development of Prefibrillar Aggregates in Insulin B Chain

Amyloid fibrils have been an important subject as they are involved in the development of many amyloidoses and neurodegenerative diseases. The formation of amyloid fibrils is typically initiated by nucleation, whereas its exact mechanisms are largely unknown. With this situation, we have previously identified prefibrillar aggregates in the formation of insulin B chain amyloid fibrils, which have provided an insight into the mechanisms of protein assembly involved in nucleation. Here, we have investigated the formation of insulin B chain amyloid fibrils under different pH conditions to better understand amyloid nucleation mediated by prefibrillar aggregates. The B chain showed strong propensity to form amyloid fibrils over a wide pH range, and prefibrillar aggregates were formed under all examined conditions. In particular, different structures of amyloid fibrils were found at pH 5.2 and pH 8.7, making it possible to compare different pathways. Detailed investigations at pH 5.2 in comparison with those at pH 8.7 have suggested that the evolution of protofibril-like aggregates is a common mechanism. In addition, different processes of evolution of the prefibrillar aggregates have also been identified, suggesting that the nucleation processes diversify depending on the polymorphism of amyloid fibrils.     

One-Pot synthesis of N-heterocyclic compounds from cyclopropenethione derivatives

The one-pot reaction of 2-tert-butylthio-3-phenylcyclopropenethione (1a) and its 3-(2-thienyl) derivative (1b) with lithium pyrrolidinide at -70 degrees C, followed by methylation with methyl iodide, gives 6-methylthio-5-phenyl-2,3-dihydro-1H-pyrrolizine (2a) and its 5-(2-thienyl) derivative (2b), respectively. The reaction of 2-tert-butylthio-3-(pyrrolidin-1-yl)cyclopropenethione (1c) with phenyllithium gives also 2a in a high yield under similar conditions, and the reactions of 1a with N-lithium salts of 3-pyrroline, hexamethyleneimine, indoline, and carbazole, piperidine-potassium tert-butoxide mixture, and phenyllithium give 6-methylthio-5-phenyl-3H-pyrrolizine (3), 2-methylthio-3-phenyl-6,7, 8,9-tetrahydro-5H-pyrrolo[1,2-a]azepine (5), 6-tert-butylthio-5-methylthio-4-phenyl-1,2-dihydro-6H-pyrrolo[3,2, 1-ij]quinoline (6), 4-tert-butylthio-5-methylthio-6-phenyl-4H-pyrido[3,2,1-jk]carbazole (7), 2-methylthio-3-phenyl-5,6,7,8-tetrahydroindolizine (4), and 1-tert-butylthio-2-methylthio-3-phenylindene (9), respectively. The structures of 2a and 3 were determined by X-ray analyses of their tricarbonylchromium complexes.     

Determination of serum cortisol using isotope dilution–liquid chromatography–mass spectrometry as a candidate reference method

We propose isotope-dilution mass spectrometry as a candidate reference method for determination of serum cortisol. The method uses liquid chromatography–mass spectrometry (LC–MS), interfaced with electrospray ionization, and selective monitoring of the [M+H]⁺ ions of cortisol and isotopically labeled cortisol. The isotope-dilution–liquid chromatography–mass spectrometry (ID–LC–MS) method simplifies sample-preparation, because samples are processed by simple solvent extraction without further clean-up and derivatization. We studied the time required for complete equilibration of endogenous cortisol and labeled cortisol spiked into serum and found it to be less than 1 h. The repeatability and the reproducibility of the method were evaluated and found to be 0.55% of the measurement value. CRM 192 and 193 from the Bureau Communautaire de Reference were analyzed for verification of the method. The results obtained from the ID–LC–MS method agreed with the certified values. The relative uncertainty of measurement results for samples in the range of a few tens of micrograms per kilogram to several hundred micrograms per kilogram was evaluated and found to be 0.56%. Immunoassay carried out by three independent clinical laboratories produced results more than 15% higher than this ID–LC–MS method, suggesting the presence of bias in the immunoassay methods.     

Synthetic studies of benzo[b]pyrrolo[4,3,2-de][1,10]phenanthroline

6,11-Dihydrobenzo[b]pyrrolo[4,3,2-de][1,10]phenanthroline-5,8-dione (6), which possesses a unique heterocyclic ring system similar to that in plakinidines A-D (1-4), was synthesized from 2-acetyl-3′-nitrodiphenylamine (16) in nine steps.