Aqueous colloidal mesoporous nanoparticles with ethenylene-bridged silsesquioxane frameworks

Aqueous colloidal mesoporous nanoparticles with ethenylene-bridged silsesquioxane frameworks with a uniform diameter of ～20 nm were prepared from bis(triethoxysilyl)ethenylene in a basic aqueous solution containing cationic surfactants. The nanoparticles, which had higher hydrolysis resistance under aqueous conditions, showed lower hemolytic activity toward bovine red blood cells than colloidal mesoporous silica nanoparticles.     

Rapid determination of terephthalic acid in the hydrothermal decomposition product of poly(ethylene terephthalate) by thermochemolysis-gas chromatography in the presence of tetramethylammonium acetate

Thermochemolysis-gas chromatography in the presence of tetramethylammonium acetate was applied to the direct determination of terephthalic acid (TPA) contained in solid decomposition products obtained from the hydrothermal recycling process of poly(ethylene terephthalate) (PET). On the chromatograms of the hydrothermal decomposition products of PET, a sharp peak of the TPA component was clearly observed as its corresponding dimethyl ester formed through the thermochemolysis reaction. Based on the peak intensities, the contents of TPA in the decomposition products were determined precisely and rapidly without using any cumbersome sample pretreatments.     

Synthesis and assignment of the absolute stereochemistry of (+)-hemifistularin 3

The first total synthesis of the marine natural product (+)-hemifistularin 3 in enantiomerically pure form was accomplished by using the amide forming reaction of (+)-spiroisoxazoline ester with the (+)-octopamine derivative. The stereodivergent strategy employed in this effort enabled the assignment of the absolute configurations at the three stereogenic centers in (+)-hemifistularin 3.     

Approximate tail probabilities of the maximum of a chi-square field on multi-dimensional lattice points and their applications to detection of loci interactions

In this study, we define a chi-square random field on a multi-dimensional lattice points index set with a direct product covariance structure and consider the distribution of the maximum of this random field. We provide two approximate formulas for the upper tail probability of the distribution based on nonlinear renewal theory and an integral-geometric approach called the volume-of-tube method. This study is motivated by the detection problem of the interactive loci pairs which play an important role in forming biological species. The joint distribution of scan statistics for detecting the pairs is regarded as the chi-square random field above, and hence the multiplicity-adjusted \(p\) -value can be calculated using the proposed approximate formulas. By using these formulas, we examine the data of Mizuta, Harushima and Kurata (Proc Nat Acad Sci USA 107(47):20417–20422, 2010) who reported a new interactive loci pair of rice inter-subspecies.     

Adsorption-Desorption Characteristics of Water Vapor on Functional Cattle Bone-Originated Apatites Powders with Mesopores

Microcrystals of cattle bone-originated apatites (r-HAp) were prepared by the dissolution-precipitation and freeze-drying processes. The r-HAp particles obtained gave 128 m 2 ;g m 1 specific surface area and 0.376 cm 3 ;g m 1 total pore volume and strong basic surface with mesopores. All the adsorption isotherms of water vapor at 288-308 K for the r-HAp powders obeyed IV-type in a classification of the BDDT. In the repeated adsorption-desorption operations, an adsorption hysteresis resulting from mesopores was recognized. The amounts of water vapor adsorbed obtained in the first adsorption operation were larger than those in the second adsorption operation, indicating that some portion of water vapor adsorbed to be irreversible adsorption. The water vapor-adsorption heats for the r-HAp were 45-60 kJ;mol m 1 , whose values were higher than natural diatomite. The amounts of water vapor adsorbed for the r-HAp were larger than those for the adsorbents, such as natural diatomite, aerosol silica, and activated carbon, at the relative partial pressures of 0-0.7.     

Synthesis of dithia- and tetrathiacyclophanes incorporating isoxazole units

The reaction of 5-bromomethyl-3-(p-bromomethylphenyl)isoxazole with o-, m-, and p-bis(mercap-tomethyl)benzenes gave the corresponding dithia- and/or tetrathiaisoxazolophanes, whose relative yields strongly depended upon the nature of the mercaptomethyl compound. The above isoxazole dibromide reacted with the bis(mercaptomethyl)isoxazole to afford a mixture of two isomeric dithiaisoxazolophanes.     

Stably extendible tangent bundles over lens spaces

The purpose of this paper is to study the stable extendibility of the tangent bundle τn(p) over the (2n+1)-dimensional standard lens space Ln(p) for odd prime p. We investigate for which m the tangent bundle τn(p) is stably extendible to Lm(p) but is not stably extendible to Lm+1(p), where we consider m=∞ if τn(p) is stably extendible to Lk(p) for any k?n, and determine m in the case n?p−3.