Hypolipidaemic Effects of Methanol Extract of Holoptelea integrifolia (Roxb.) Planchon Bark in Diet-Induced Obese Rats

The leaf and bark paste of Holoptelea integrifolia is traditionally used for the treatment of obesity in Asian countries. However, no scientific studies have been undertaken to reveal the actual mechanism of action. The present study aimed to investigate the hypolipidaemic effect of H. integrifolia and its mechanism in diet-induced obese rat model. After 4 weeks of oral administration, blood samples were collected for the estimation of serum lipids, lecithin: cholesterolacyltransferase (LCAT) apolipoproteins (apo) and liver for HMG-CoA reductase (HMGR) assay. The faecal samples were also collected to estimate the faecal fat content. The H. integrifolia treatment markedly lowered body weight, serum lipids and apo B and increase high-density lipoprotein-cholesterol and apo A1 concentrations. In this study, HMGR activity was enormously reduced, which helps to reduce cholesterol biosynthesis and an increase in LCAT activity was also observed. The detailed faecal analysis showed a remarkable increase in faecal lipids, which indicates the ability to inhibit intestinal fat absorption. The methanol fraction of H. integrifolia on LC-MS and tandem mass spectrometry analysis shows the presence of a compound, 3-(7-ethoxy-4-methyl-2-oxo-2H-chromen-3-yl)propanoate (C1). The result showed that the significant hypolipidaemic effect of H. integrifolia may be linked to its ability to inhibit HMGR activity and block intestinal fat absorption.     

Rapid synthesize of gold nanoparticles by microwave irradiation method and its application as an optical limiting material

We present rapid synthesis of gold nanoparticles by microwave irradiation method. Sample with average particle size 7.7 nm is obtained from TEM. Linear and nonlinear optical studies of the prepared samples are discussed. Reverse saturable absorption (RSA) at longitudinal surface plasmon resonance (SPR) in gold nanoparticles (Au NPs) have been observed using Z-scan and transient absorption techniques with 532 nm laser pulses. Such RSA behavior makes Au NPs an ideal candidate for optical limiting applications.     

Parity-alternating permutations and successions

The study of parity-alternating permutations of {1, 2, … n} is extended to permutations containing a prescribed number of parity successions — adjacent pairs of elements of the same parity. Several enumeration formulae are computed for permutations containing a given number of parity successions, in conjunction with further parity and length restrictions. The objects are classified using direct construction and elementary combinatorial techniques. Analogous results are derived for circular permutations.     

The Synthesis of Ethyl 5-Vinyl-2-Quinuclidine Carboxylate

The synthesis of the minor indolic cinchona alkaloid, cinchonexine (1), from ethyl-5-vinyl-2-quinuclidine carboxylate (2) was reported in 1958¹ but the preparation of 2 was not described until several years later². No further reports on this problem have since appeared. Since 2 was previously obtained in very poor yield from the Beckmann rearrangement of quininene oxine² a more direct approach to its preparation was initiated in order to complete the total synthesis of cinchonexine from synthetically available precursors. Maroquinine (3a) which not only has been prepared in both racemic ³ and optically active^3b forms but is also readily available from quinine⁴ was selected as the starting material fro this synthetic sequence.     

Fuzzy sets and the modelling of physician decision processes,part II: fuzzy diagnosis decision models

Our concern is with the development of a more accurate mathematical model of physician diagnosis decision processes. Using the complete information net of matrices outputed from Part I, the various diagnoses processes—medical hypothesis, initial preliminary diagnoses, other preliminary diagnosis and final diagnoses, are modelled as fuzzy matrices. A general fuzzy decision model which could be particularized to each of the foregoing cases is then developed. Our general technique is based on fuzzy clustering theory with the criterion function being a modified form of the minimum Minkowski metric.     

gem-Dibromomethylarenes: a convenient substitute for noncommercial aldehydes in the knoevenagel-doebner reaction for the synthesis of alpha,beta-unsaturated carboxylic acids

A facile synthesis of alpha,beta-unsaturated carboxylic acids from gem-dibromomethylarenes is described. gem-Dibromomethylarenes are employed for the first time in the Knoevenagel-Doebner reaction as aldehyde equivalents for the efficient synthesis of alpha,beta-unsaturated carboxylic acids.     

2H and 139La NMR Spectroscopy in Aqueous Solutions at Geochemical Pressures

Nuclear spin relaxation rates of ²H and ¹³⁹La in LaCl₃+²H₂O and La(ClO₄)₃+²H₂O solutions were determined as a function of pressure in order to demonstrate a new NMR probe designed for solution spectroscopy at geochemical pressures. The ²H longitudinal relaxation rates (T₁) vary linearly to 1.6 GPa, consistent with previous work at lower pressures. The ¹³⁹La T₁ values vary both with solution chemistry and pressure, but converge with pressure, suggesting that the combined effects of increased viscosity and enhanced rates of ligand exchange control relaxation. This simple NMR probe design allows experiments on aqueous solutions to pressures corresponding roughly to those at the base of the Earth’s continental crust.