Innovative synthetical and structural features of new aryltellurenyl iodides

The syntheses and the structural characterization of the compounds [(mes)₂Te–Te(I)mes], (PyH)[mesTeI₃(I₃)] (mes = mesityl = 2,4,6-trimethylphenyl; Py = pyridine), (PyH)₃[dmephTeI₂(I₂)]₂(I₃) (dmeph = 2,6-dimethylphenyl), (PyH)₂[RTeI₄]₂·(CH₃)CO(CH₃)·C₆H₅CH₃ (R = p-tert-butylphenyl) and (PyH)₂[PhTeI₄]₂ (Ph = phenyl) are presented. Some earlier analog preparations are compared and the influence of ortho substituents in the aryl group on the oxidation state of tellurium is discussed, as well as the observed conditions for the formation of poly-iodides chains.     

Cancer Segmentation by Entropic Analysis of Ordered Gene Expression Profiles

The availability of massive gene expression data has been challenging in terms of how to cure, process, and extract useful information. Here, we describe the use of entropic measures as discriminating criteria in cancer using the whole data set of gene expression levels. These methods were applied in classifying samples between tumor and normal type for 13 types of tumors with a high success ratio. Using gene expression, ordered by pathways, results in complexity–entropy diagrams. The map allows the clustering of the tumor and normal types samples, with a high success rate for nine of the thirteen, studied cancer types. Further analysis using information distance also shows good discriminating behavior, but, more importantly, allows for discriminating between cancer types. Together, our results allow the classification of tissues without the need to identify relevant genes or impose a particular cancer model. The used procedure can be extended to classification problems beyond the reported results.     

Laguerre Wavelet Approach for a Two-Dimensional Time–Space Fractional Schrödinger Equation

This article is devoted to the determination of numerical solutions for the two-dimensional time–spacefractional Schrödinger equation. To do this, the unknown parameters are obtained using the Laguerre wavelet approach. We discretize the problem by using this technique. Then, we solve the discretized nonlinear problem by means of a collocation method. The method was proven to give very accurate results. The given numerical examples support this claim.     

Synthesis and Characterization of [Hg(sulfamethoxazolato)2]·2DMSO and[Cu2(μ‐CH3CO2)4(sulfamethoxazole)2]

[Hg(sulfamethoxazolato)₂]·2DMSO ( 1 ) and [Cu₂(CH₃COO)₄(sulfa‐methoxazole)₂] ( 2 ) can be obtained by the reaction of sulfamethoxazole with mercury acetate or copper acetate in methanol. The structures of the two complexes were characterized by single crystal X—ray diffractometry. Compound 1 consists of sulfamethoxazolato ligands bridging the metal ions building an unidimensional chain. Two solvent dimethylsulfoxide molecules are involved via N‐H···O hydrogen bridges. The mercury atom shows a linear primary coordination arrangement formed by two trans deprotonated sulfonamidic nitrogen atoms. The overall coordination around the metal atom may be regarded as a strongly distorted octahedron when the interactions of mercury with four sulfonamidic oxygen atoms [bond distances of 2.761(4) Å—2.971(4) Å] are also considered to build an equatorial plane and the N1 and N1′ atoms [bond distance of 2.037(5) Å] occupy the apical positions. Compound 2 is a dinuclear complex in which the copper ions are bridged by four syn‐syn acetate ligands which are related by a symmetry centre located in the centre of the complex. Each copper atom presents a nearly octahedral coordination where the equatorial plane is formed by four oxygen atoms and an isoxazolic nitrogen atom and the second copper atom occupy the apical positions.     

First chemical study of anaspidean Syphonota geographica: structure of degraded sterols aplykurodinone-1 and -2

Two unprecedented degraded sterols, aplykurodinone-1 (1) and -2 (2), have been isolated from the skin of the marine anaspidean Syphonota geographica, collected along the coasts of Greece. The structures and the relative stereochemistry were established by spectroscopic analysis and confirmed by chemical correlation with related known compounds.     

Photoprotection in the brown alga Macrocystis pyrifera: evolutionary implications

The dissipation of energy as heat is essential for photosynthetic organisms to protect themselves against excess light. We compared Photosystem II florescence changes (non-photochemical quenching, NPQ) in the brown alga Macrocystis pyrifera with that of Ficus sp., a higher plant to examine if the mechanism of heat dissipation (energy-dependent quenching, qE) differs between these evolutionary distant groups of phototrophs. We discovered that M. pyrifera had a slower rise of NPQ upon illumination than the Ficus sp. Further, the NPQ relaxation phase that takes place in the first minutes after light to dark transition is absent in this brown alga. We found that the NPQ induction rate in this alga was 1.5 times faster in preilluminated samples than in dark-adapted samples; this was associated with an increase in the rate of accumulation of the carotenoid zeaxanthin. Therefore, we conclude that NPQ in M. pyrifera is associated only with the formation of zeaxanthin. These results indicate that M. pyrifera lacks the fast component of qE that is related to allosteric changes in the light harvesting complexes of Ficus sp., a representative of higher plants. Although the xanthophyll cycle of this brown alga is similar to that of Ficus sp., yet, the transthylakoid proton gradient (ΔpH) does not influence NPQ beyond the activation of the violaxanthin de-epoxidase enzyme. These findings suggest that NPQ control mechanisms are not universal and we suggest that it may have diverged early in the evolution of different groups of eukaryotic phototrophs.