hemN Research Articles

Quantitative and Qualitative Analysis of Micronuclei in the Buccal Mucosal Cells of Individuals Associated with Tobacco

Introduction: Micronucleus/micronuclei) have the potential to serve as an important biomarker in exfoliated cell. Exfoliated buccal mucosal cells can be evaluated using MN assay which can be applied to individuals practicing tobacco habits and are at risk of developing oral cancer. Material and Methods: 80 tobacco users and 20 non tobacco users as control were included in the study. Smears were taken and stained with HE MN outline and nuclear outline was obtained for acridine orange, followed by H&E and feulgen stain. Discussion: In our study quantitatively, MN was counted in maximum number using H&E stain, followed by acridine orange and feulgen. Qualitatively, MN count was best viewed using acridine orange stain under a fluorescence microscope, followed by H&E and feulgen under a light microscope. Conclusion: Assessment of MN in exfoliated cells is a promising tool to study epithelial carcinogens in the oral cavity.

Stepwise Construction of Manganese–Chromium Carbonyl Chalcogenide Complexes: Synthesis, Electrochemical Properties, and Computational Studies

When trigonal-bipyramidal clusters, [PPN][E(2)Mn(3)(CO)(9)] (E = S, Se), were treated with Cr(CO)(6) and PPNCl in a molar ratio of 1:1:2 or 1:2:2 in 4 M KOH/MeCN/MeOH solutions, mono-Cr(CO)(5)-incorporated HE(2)Mn(3)-complexes [PPN](2)[HE(2)Mn(3)Cr(CO)(14)] (E = S, [PPN](2)[1a]; Se, [PPN](2)[1b]), respectively, were formed. X-ray crystallographic analysis showed that 1a and 1b were isostructural and each displayed an E(2)Mn(3) square-pyramidal core with one of the two basal E atoms externally coordinated with one Cr(CO)(5) group and one Mn-Mn bond bridged by one hydrogen atom. However, when the TMBA(+) salts for [E(2)Mn(3)(CO)(9)](-) were mixed with Cr(CO)(6) in a molar ratio of 1:1 in 4 M KOH/MeOH solutions and refluxed at 60 °C, mono-Cr(CO)(3)-incorporated E(2)Mn(3)Cr octahedral clusters [TMBA](3)[E(2)Mn(3)Cr(CO)(12)] (E = S, [TMBA](3)[2a]; Se, [TMBA](3)[2b]), respectively, were obtained. Clusters 2a and 2b were isostructural, and each consisted of an octahedral E(2)Mn(3)Cr core, in which each Mn-Mn or Mn-Cr bond of the Mn(3)Cr plane was semibridged by one carbonyl ligand. Clusters 1a and 1b (with [TMBA] salts) underwent metal core closure to form octahedral clusters 2a and 2b upon treatment with KOH/MeOH at 60 °C. In addition, 1a and 1b were found to undergo cluster expansion to form di-Cr(CO)(5)-incorporated HE(2)Mn(3)-clusters [HE(2)Mn(3)Cr(2)(CO)(19)](2-) (E = S, 3a; Se, 3b), respectively, upon the addition of 1 or 2 equiv of Cr(CO)(6) heated in refluxing CH(2)Cl(2). Clusters 3a and 3b were structurally related to clusters 1a and 1b, but with the other bare E atom (E = S, 3a; Se, 3b) further externally coordinated with one Cr(CO)(5) group. The nature, cluster transformation, and electrochemical properties of the mixed manganese-chromium carbonyl sulfides and selenides were systematically discussed in terms of the chalcogen elements, the introduced chromium carbonyl group, and the metal skeleton with the aid of molecular calculations at the BP86 level of the density functional theory.

Theoretical study of coaxial fibers

A mathematical solution of the wave equation for coaxial fibers having four different refractive-index profiles is presented. The transcendental equations are obtained under LP approximation and calculated for comparison of HE(mn)-mode-dispersion characteristics. Attention is paid to the HE(11) and HE(12) modes because of their importance for modeling directional couplers, and calculations are carried out to obtain dispersion dependence on dimensional parameters of the fibers. The field expressions also are given, and the spatial distributions of the HE(11) and HE(12) modal fields of all coaxial structures for different conditions of propagation are calculated.