A density functional theory study on the water aggregation behaviour of fatty acid-based anionic surface active ionic liquids

Structural Chemistry - The hydrogen bond interactions between methyl-imidazolium cation (MIM+) and fatty acid anions (CmHnCOO–, where m?=?1–6; n-3–13) of ionic liquids...     

Measurement of storage time, estimation of ion number and study of absorption line profile in a Paul trap

Europium (Eu⁺) ions were confined in a Paul trap and detected by non-destructive method. Storage time of Eu⁺ ions achieved in vacuum was improved by orders of magnitude employing buffer gas cooling. The experimentally detected signal was fitted to the ion response signal and the total number of ions trapped was estimated. It is found that the peak signal amplitude as well as the product of FWHM and the peak signal amplitude is proportional to the total number of trapped ions. The trapped ion secular frequency was swept at different rates and its effect on the absorption line profile was studied both experimentally and theoretically.     

Radiation-induced decomposition of the tributyl phosphate-nitric acid system: Role of nitric acid

Radiation-induced decomposition of tributyl phosphate-nitric acid as a two-component system has been studied. Degradation products, dibutylphosphoric acid (DBP) and monobutylphosphoric acid (MBP), were determined by separation-extraction method. 0.59, 0.78 and 1.38 are the G (DBP) values and 0.15, 0.17 and 0.13 are the G (MBP) values obtained for pure TBP, TBP-3M HNO₃ extract and TBP-5M HNO₃ extract, respectively. G (–HNO₃) values are 5.19 and 6.15 for 3M HNO₃ and 5M HNO₃ extracts. It is shown that nitric acid plays a significant role in enhancing the decomposition of TBP.     

Correction: Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity

After the publication of the work entitled "Dermatan sulfate in tunicate phylogeny: Order-specific sulfation pattern and the effect of [→4IdoA(2-Sulfate)β-1→3GalNAc(4-Sulfate)β-1→] motifs in dermatan sulfate on heparin cofactor II activity", by Kozlowski et al., BMC Biochemistry 2011, 12:29, we found that the legends to Figures 2 to 5 contain serious mistakes that compromise the comprehension of the work. This correction article contains the correct text of the legends to Figures 2 to 5.     

Application of fission track registration technique in the estimation of fissile materials

Analysis of fissile materials in solution by fission track registration technique has been extended to plutonium in solution of its alloys. In these estimations, the results agreed within 1–4% with the average of those obtained by other chemical and instrumental methods like potentiometry, mass-spectrometry and X-ray fluorescence. Some special practical problems encountered in the analysis of plutonium solutions are noted. Various factors affecting the results have been investigated and the necessary precautions for reducing these errors have been indicated. The advantages of the method over some other conventional methods have also been discussed. It is suggested that a source of about 10 μg of²⁵²Cf corresponding to a neutron flux of about 10⁷ n·cm⁻²·sec⁻¹ is ideal for these experiments.     

Chiral prostanoid intermediates from aucubin

Several potentially useful prostanoid intermediates have been prepared from aucubin. Dry DMSO-NBS converts enol ethers to α-bromoesters in one step.     

Targeting glycosylation pathways and the cell cycle: sugar-dependent activity of butyrate-carbohydrate cancer prodrugs

Short-chain fatty acid (SCFA)-carbohydrate hybrid molecules that target both histone deacetylation and glycosylation pathways to achieve sugar-dependent activity against cancer cells are described in this article. Specifically, n-butyrate esters of N-acetyl-D-mannosamine (But4ManNAc, 1) induced apoptosis, whereas corresponding N-acetyl-D-glucosamine (But4GlcNAc, 2), D-mannose (But5Man, 3), or glycerol (tributryin, 4) derivatives only provided transient cell cycle arrest. Western blots, reporter gene assays, and cell cycle analysis established that n-butyrate, when delivered to cells via any carbohydrate scaffold, functioned as a histone deacetylase inhibitor (HDACi), upregulated p21WAF1/Cip1 expression, and inhibited proliferation. However, only 1, a compound that primed sialic acid biosynthesis and modulated the expression of a different set of genes compared to 3, ultimately killed the cells. These results demonstrate that the biological activity of butyrate can be tuned by sugars to improve its anticancer properties.     

Mutually orthogonal graph squares

A decomposition ??={G₁, G₂,…,G_s} of a graph G is a partition of the edge set of G into edge‐disjoint subgraphs G₁, G₂,…,G_s. If G_i?H for all i∈{1, 2, …, s}, then ?? is a decomposition of G by H. Two decompositions ??={G₁, G₂, …, G_n} and ?={F₁, F₂,…,F_n} of the complete bipartite graph K_n,n are orthogonal if |E(G_i)∩E(F_j)|=1 for all i,j∈{1, 2, …, n}. A set of decompositions {??₁, ??₂, …, ??_k} of K_{n, n} is a set of k mutually orthogonal graph squares (MOGS) if ??_i and ??_j are orthogonal for all i, j∈{1, 2, …, k} and i≠j. For any bipartite graph G with n edges, N(n, G) denotes the maximum number k in a largest possible set {??₁, ??₂, …, ??_k} of MOGS of K_{n, n} by G. El‐Shanawany conjectured that if p is a prime number, then N(p, P_{p+ 1})=p, where P_{p+ 1} is the path on p+ 1 vertices. In this article, we prove this conjecture. © 2009 Wiley Periodicals, Inc. J Combin Designs 17: 369–373, 2009