Description of cyclopropane with Backone equation of state

This paper aims to accurately describe the thermodynamic properties of Cyclopropane with a molecular based BACKONE equation of state. The parameters of the BACKONE equation of state found by fitting to experimental vapor pressures and liquid densities are the characteristic temperature T ₀, characteristic density ρ₀, anisotropy factor α, and reduced quadrupolar moment Q*². The values of these parameters are 393.9583 K, 6.076139 mol/L, 1.295445, and 0.699483, respectively. The average absolute deviation between experimental values and those derived from BACKONE EOS is 0.29% for vapor pressures, 0.75% for saturated liquid densities. The prediction power of the BACKONE equation of state are investigated. It is shown that the uncertainties of values derived from the BACKONE equation of state are within 0.90% for isobaric densities in the liquid phase and 2.0% for enthalpy of evaporation.     

Structural,electronic, and optical properties of some new dithienosilole derivatives

Structural Chemistry - Structural, electronic, and optical properties of a series of organic semiconductors based on dithienosilole (DTS) and its derivatives were theoretically studied using...     

Cytotoxic constituents from Helicteres hirsuta collected in Vietnam

Abstract

Phytochemical study on the extract of Vietnamese medicinal plant Helicteres hirsuta Lour. has led to the isolation and structural elucidation of twelve secondary metabolites, 3-O-trans-caffeoylbetulinic acid (1), 3β-benzoylbetulinic acid (2), betulinic acid methyl ester (3), betulinic acid (4), lupeol (5), 4-hydroxybenzoic acid (6), 3,4-dihydroxybenzoic acid methyl ester (7), 4-hydroxy-3,5-dimethoxybenzoic acid (8), 5,8-dihydroxy-7,4′-dimethoxyflavone (9), isoscutellarein 4’-methyl ether 8-O-β-D-glucopyranoside (10), methyl caffeate (11) and stigmasterol (12). Especially, compound 2 was reported as a new natural product. Their structures were elucidated by a combination of 2D NMR and ESI-FT-ICR-MS spectroscopies. Furthermore, eight compounds were tested for their cytotoxicity against five cancer cell lines (Hela, HepG2, SK-LU-1, AGS and SK-MEL-2). The results showed that compounds (1, 3-5, 9) have moderate activities. This is the first study on the chemical constituents and their cytotoxicity of the Vietnamese Helicteres hirsuta L.     

Identification of an inverse source problem for time‐fractional diffusion equation with random noise

In this paper, we consider an inverse source problem for a time fractional diffusion equation. In general, this problem is ill posed, therefore we shall construct a regularized solution using the filter regularization method in the random noise case. We will provide appropriate conditions to guarantee the convergence of the approximate solution to the exact solution. Then, we provide examples of filters in order to obtain error estimates for their approximate solutions. Finally, we present a numerical example to show efficiency of the method.     

Cytoprotective Polyketides from Sponge-Derived Fungus Lopadostoma pouzarii

The new polyketides lopouzanones A and B, as well as the new 1-O-acetyl and 2-O-acetyl derivatives of dendrodochol B, were isolated from the sponge-derived marine fungus Lopadostoma pouzarii strain 168CLC-57.3. Moreover, six known polyketides, gliorosein, balticolid, dendrodolide G, dihydroisocoumarine, (–)-5-methylmellein, and dendrodochol B, were identified. The structures of the isolated compounds were determined by a combination of NMR and ESIMS techniques. The absolute configurations of the lopouzanones A and B were determined using the Mosher’s method. The cytotoxicity of the isolated compounds against human prostate cancer cells PC-3 and normal rat cardiomyocytes H9c2 was investigated. Gliorosein showed weak DPPH radical-scavenging activity and in vitro cardioprotective effects toward rotenone toxicity and CoCl₂-mimic hypoxia.     

The renormalizability and the asymptotically behaviour of the extended Wess-Zumino models

By using the path integral method for superfields the Ward identities and the Callan-Symanzik equations for the extended Wess-Zumino models are derived. From these the renormalizability and the asymptotic behaviour of all the extended Wess-Zumino models ind=2,4 (mod 8)-dimensional space-time are studied. In particular, we come to the conclusion that the supersymmetric Ward identities together with the broken chiral Ward identities imply that a single wave function renormalization is sufficient to renormalize the theory, and the theory is not asymptotically free.We would like to thank Professor Dao Vong Duc for putting forward the problem and for his helpful discussions. One of us (H. N. L) would like to thank Professor Abdus Salam, the International Atomic Energy and UNESCO for hospitality at the International Centre for Theoretical Physics, Trieste.     

Ergosta-4,6,8(14),22-tetraen-3-one from Vietnamese Xylaria sp. possessing inhibitory activity of nitric oxide production

From the methanolic extract of Xylaria sp. collected in Vietnam, a fluorescent constituent, ergosta-4,6,8(14),22-tetraen-3-one (1) was isolated and elucidated by the combination of 2D NMR, high resolution MS, IR and UV spectroscopy. Its inhibitory activity of nitric oxide production in RAW 264.7 cells stimulated by lipopolysaccharide was examined and showed a potential activity with the IC(50) value of 28.96 microM.     

Solving generalized convex multiobjective programming problems by a normal direction method

We use normal directions of the outcome set to develop a method of outer approximation for solving generalized convex multiobjective programming problems. We prove the convergence of the method and report some computational experiments. As an application, we obtain an algorithm to solve an associated multiplicative problem over a convex constraint set.     

Variations of Landau’s theorem for p-regular and p-singular conjugacy classes

The well-known Landau’s theorem states that, for any positive integer k, there are finitely many isomorphism classes of finite groups with exactly k (conjugacy) classes. We study variations of this theorem for p-regular classes as well as p-singular classes. We prove several results showing that the structure of a finite group is strongly restricted by the number of p-regular classes or the number of p-singular classes of the group. In particular, if G is a finite group with O_p(G) = 1 then |G/F(G)|_p' is bounded in terms of the number of p-regular classes of G. However, it is not possible to prove that there are finitely many groups with no nontrivial normal p-subgroup and kp-regular classes without solving some extremely difficult number-theoretic problems (for instance, we would need to show that the number of Fermat primes is finite).     

Finite groups with an irreducible character of large degree

Let G be a finite group and d the degree of a complex irreducible character of G, then write |G| = d(d + e) where e is a nonnegative integer. We prove that |G| ≤ e⁴?e³ whenever e > 1. This bound is best possible and improves on several earlier related results.