Composites of Anthraquinone Dyes@HKUST-1 with Tunable Microstructuring: Experimental and Theoretical Interaction Studies

The metal–organic framework (MOF) HKUST-1 was employed as an interaction matrix for fundamental loading studies of anthraquinone dyes. Chosen dyes were alizarin (A), alizarin S (AS), disperse blue 1 (B1), disperse blue 3 (B3), disperse blue 56 (B56) and purpurin (P). All materials were characterized by XRD, FTIR, TGA and SEM. Hence the interaction of dyes with the framework was characterized by theoretical–experimental differential analysis. One-pot loading strategy resulted in more efficient scavenging of dyes, and reached 100 % for B56 using 50 mg L⁻¹. SEM revealed important microstructural changes, the smaller crystals ranged 0.8–3 μm in size and almost all composite sizes were from this to higher values, reaching 70 μm, with varying shapes. Two composites were larger in size range (about 2500–1000 μm), and were shaped as rods, octahedrons and coffin lids. Indeed, the microstructure could be modulated depending on preparation conditions and type of loaded dye. For the higher loading series, N₂ adsorption and XPS experiments were carried on to further evidence dye–MOF interactions. Ab initio prediction of structural properties for A@HKUST-1 and P@HKUST-1 were obtained by means of solid-state CRYSTAL14 code at the PBE0 level of theory. Computed findings evidenced two O→Cu coordinative bonds, one from O-ketone and the other from O-phenolate moiety as main interactions towards CuNET centers.     

A multifractal approach for stock market inefficiency

In this paper, the multifractality degree in a collection of developed and emerging stock market indices is evaluated. Empirical results suggest that the multifractality degree can be used as a quantifier to characterize the stage of market development of world stock indices. We develop a model to test the relationship between the stage of market development and the multifractality degree and find robust evidence that the relationship is negative, i.e., higher multifractality is associated with a less developed market. Thus, an inefficiency ranking can be derived from multifractal analysis. Finally, a link with previous volatility time series results is established.     

Synthesis,structural and larvicidal studies of a series of triorganotin chrysanthemumates

A series of triorganotin chrysanthemumates (2,2‐dimethyl‐3‐(2‐methyl‐1‐propenyl)cyclopropanecarboxylates) (R₃SnO₂CC₉H₁₅) where R = methyl, ethyl, n‐butyl and phenyl was synthesized. The solid state structures were deduced using infrared (IR) and Mössbauer spectroscopies. The spectroscopic results indicated that all the compounds were found to be five‐coordinated in the solid state. Based on the NMR results, all the compounds are tetrahedral in solution. Larvicidal activities of the compounds were evaluated against the second instar stage of Aedes aegypti, Anopheles stephensi and Culex pipiens quinquefasciatus mosquitoes. The toxicity results indicated that these compounds of triorganotins were effective larvicides against all three species of larvae. Copyright © 2011 John Wiley & Sons, Ltd.     

Degenerations of 8-Dimensional 2-step Nilpotent Lie Algebras

Algebras and Representation Theory - In this work, we consider degenerations between 8-dimensional 2-step nilpotent Lie algebras over ? and obtain the geometric classification of the variety...     

An approach to predictive-reactive scheduling of parallel machines subject to disruptions

In this paper, a new predictive-reactive approach to a parallel machine scheduling problem in the presence of uncertain disruptions is presented. The approach developed is based on generating a predictive schedule that absorbs the effects of possible uncertain disruptions through adding idle times to the job processing times. The uncertain disruption considered is material shortage, described by the number of disruption occurrences and disruption repair period. These parameters are specified imprecisely and modelled using fuzzy sets. If the impact of a disruption is too high to be absorbed by the predictive schedule, a rescheduling action is carried out. This approach has been applied to solving a real-life scheduling problem of a pottery company.     

Discovering Echinococcus granulosus thioredoxin glutathione reductase inhibitors through site-specific dynamic combinatorial chemistry

In this study, we report a strategy using dynamic combinatorial chemistry for targeting the thioredoxin (Trx)-reductase catalytic site on Trx glutathione reductase (TGR), a pyridine nucleotide thiol-disulfide oxido-reductase. We chose Echinococcus granulosus TGR since it is a bottleneck enzyme of platyhelminth parasites and a validated pharmacological target. A dynamic combinatorial library (DCL) was constructed based on thiol-disulfide reversible exchange. We demonstrate the use of 5-thio-2-nitrobenzoic acid (TNB) as a non-covalent anchor fragment in a DCL templated by E. granulosus TGR. The heterodimer of TNB and bisthiazolidine (2af) was identified, upon library analysis by HPLC (IC $_{50}$  = 24  $\upmu $ M). Furthermore, 14 analogs were synthetically prepared and evaluated against TGR. This allowed the study of a structure–activity relationship and the identification of a disulfide TNB-tricyclic bisthiazolidine (2aj) as the best enzyme inhibitor in these series, with an IC $_{50}$  = 14  $\upmu $ M. Thus, our results validate the use of DCL for targeting thiol-disulfide oxido-reductases.     

Effect of oviductal secretion components on the fertilizing capacity of amphibian sperm: biological and ultrastructural studies

The present study was carried out to analyze the fertilization-supporting activity of Rhinella arenarum egg-jelly components. Spermatozoa were treated with diffusible factor (DF) constituted by the components released from the jelly coat into deionized water or with full jelly (FJ) containing all the components secreted by the oviductal pars convoluta (PC) during the transit of the oocytes through the duct, or with washed jelly (WJ) constituted only by structural components. Both jellies were solubilized by ultraviolet irradiation. These gametes were used for ultrastructural and biological studies in order to determine the acrosome state and the fertilizing capacity. Additional experiments were performed by using Ca(2+), a diffusible cation present in R. arenarum jelly envelopes. Results demonstrated a marked increase in the acrosome reaction (AR) of sperm treated with FJ or DF compared to the controls (Ringer's solution), no significant differences being observed between both treatments, while WJ showed low AR percentages similar to the ones obtained with the controls. The addition of Ca(2+) induced an increase in this parameter in a dose-dependent manner, although the values reached with FJ or DF were not attained. The results of the "in vitro" fertilization show a strong inverse association to the acrosome reaction (AR) rate. Treatment with Ca(2+) at the concentration present in the jelly (6.3 ± 0.9 mM) inhibited the fertilizing capacity as a function of incubation time, showing that at 2 min there was a decrease in the fertilization percentages compared to 10% Ringer's. Data indicated that Ca(2+) present in jelly is involved in the AR induction but suggests the possible participation of other diffusible and/or structural components of the oviductal secretion in this process.     

Cohomology and deformations for the Heisenberg Hom-Lie algebras

ABSTRACT

In this work, we consider the Heisenberg Lie algebra with all its Hom-Lie structures. We completely characterize the cohomology and deformations of any order of all Heisenberg Hom-Lie algebras of dimension 3.     

Synthesis and DPPH radical scavenging activity of prenylated phenol derivatives

The synthesis of twenty six prenylated phenols derivatives is reported. These compounds were obtained under mild conditions via Electrophilic Aromatic Substitution (EAS) coupling reactions between phenol derivatives containing electron-donor subtituents and 3-methyl-2-buten-1-ol using BF(3)×OEt(2). Dialkylations were also produced with this method. The formation of a chroman ring by intramolecular cyclization between a sp2 carbon from the prenyl group with the hydroxyl substituent in the ortho position occurred with some phenols. All the synthesized compounds were evaluated as antioxidants according to a DPPH radical scavenging activity assay. IC(50) values of five synthesized compounds indicated they were as good antioxidants as Trolox?.