Spontaneous formation of a chiral (Mo2O2S2)2+-based cluster driven by dimeric {Te2O6}-based templates

Utilization of [Mo2S2O2(H2O)6]2+ and a tellurite anion led to the formation of three new clusters, 1–3, with unique structural features. The tellurite anion not only templated the formation of [(Mo2O2S2)4(TeO3)(OH)9]3− 1 and [(Mo2O2S2)12(TeO3)4(TeO4)2 (OH)18]10− 3, but also the in situ generation of two different types of dimeric {Te2O6} based moieties induced the spontaneous assembly of the chiral [(Mo2O2S2)10(TeO3)(Te2O6)2(OH)18]8− anionic cluster, 2

P2X receptors as targets for the treatment of status epilepticus.

Prolonged seizures are amongst the most common neurological emergencies. Status epilepticus is a state of continuous seizures that is life-threatening and prompt termination of status epilepticus is critical to protect the brain from permanent damage. Frontline treatment comprises parenteral administration of anticonvulsants such as lorazepam that facilitate γ-amino butyric acid (GABA) transmission. Because status epilepticus can become refractory to anticonvulsants in a significant proportion of patients, drugs which act on different neurotransmitter systems may represent potential adjunctive treatments. P2X receptors are a class of ligand-gated ion channel activated by ATP that contributes to neuro- and glio-transmission. P2X receptors are expressed by both neurons and glia in various brain regions, including the hippocampus. Electrophysiology, pharmacology and genetic studies suggest certain P2X receptors are activated during pathologic brain activity. Expression of several members of the family including P2X2, P2X4, and P2X7 receptors has been reported to be altered in the hippocampus following status epilepticus. Recent studies have shown that ligands of the P2X7 receptor can have potent effects on seizure severity during status epilepticus and mice lacking this receptor display altered seizures in response to chemoconvulsants. Antagonists of the P2X7 receptor also modulate neuronal death, microglial responses and neuroinflammatory signaling. Recent work also found altered neuronal injury and inflammation after status epilepticus in mice lacking the P2X4 receptor. In summary, members of the P2X receptor family may serve important roles in the pathophysiology of status epilepticus and represent novel targets for seizure control and neuroprotection

Effect of chemical functionalization on the electrochemical properties of conducting polymers. Modification of polyaniline by diazonium ion coupling and subsequent reductive degradation

The electrochemical properties of polyaniline (PANI) can be altered by coupling the polymer with aryldiazonium ions. The ions are synthesized by diazotization of aromatic primary amines (1-aminoanthraquinone, sulphadiazine and 4-cyanoaniline) bearing functional groups which are then linked to the polyaniline backbone. All materials produced are electroactive, suggesting that the reaction involves coupling of the diazonium ion with the aromatic rings and not nucleophilic substitution by the aminic nitrogen of PANI on the aryl cations. The electrochemical properties of the modified polymers are different to those of PANI, likely due to electronic and steric effects of the attached groups. Reductive degradation of the azo linkages, using dithionite ion, removes the attached moieties leaving primary amino groups attached to the polyaniline backbone. In that way, the effect of the attached groups on the electrochemical properties of PANI is eliminated. FTIR spectroscopy measurement of the different polymers supports the proposed mechanism. Using the method a polymer containing redox (anthraquinone) groups, which could be used for charge storage, is obtained. Additionally a material containing sulphadiazine moieties, which can be released in vivo by bacterial activity, is also produced. The molecule is a well-known sulfa drug with bacteriostatic activity. The reaction sequence seems to be of general application to modify polyanilines, by attaching functional groups, and then to produce a PANI backbone bearing primary amino groups. Evidence is presented on the kinetic control of attached group removal. © 2011 Elsevier Ltd. All rights reserved.Fil: Acevedo, Diego Fernando. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; ArgentinaFil: Rivarola, Claudia Rosana. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Miras, María C.. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; ArgentinaFil: Barbero, César Alfredo. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Departamento de Química; Argentina. Universidad Nacional de Río Cuarto. Facultad de Ciencias Exactas Fisicoquímicas y Naturales. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados. - Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Tecnologías Energéticas y Materiales Avanzados; Argentin

P2X7 receptor in epilepsy; role in pathophysiology and potential targeting for seizure control.

The P2X7 receptor is an ATP-gated non-selective cation-permeable ionotropic receptor selectively expressed in neurons and glia in the brain. Activation of the P2X7 receptor has been found to modulate neuronal excitability in the hippocampus and it has also been linked to microglia activation and neuroinflammatory responses. Accordingly, interest developed on the P2X7 receptor in disorders of the nervous system, including epilepsy. Studies show that expression of the P2X7 receptor is elevated in damaged regions of the brain after prolonged seizures (status epilepticus) in both neurons and glia. P2X7 receptor expression is also increased in the hippocampus in experimental epilepsy. Recent data show that mice lacking the P2X7 receptor display altered susceptibility to status epilepticus and that drugs targeting the P2X7 receptor have potent anticonvulsant effects. Together, this suggests that P2X7 receptor ligands may be useful adjunctive treatments for refractory status epilepticus or perhaps pharmacoresistant epilepsy. This review summarizes the evidence of P2X7 receptor involvement in the pathophysiology of epilepsy and the potential of drugs targeting this receptor for seizure control

Influencia de la concentración de la salmuera en la difusión de azúcares y cloruro de sodio durante el procesamiento de aceitunas verdes variedad Arauco

The green olive variety Arauco were debittered using lye concentrations of, 2.50% NaOH.They were then subjected to two rinsing processes with tap water. Next, the olives were cured with brines at 7%, 10% and 13% sodium chloride concentration. During this curing process, the loss of reducing sugars from the olives, and the diffusion of sodium chloride into the olives were quantified. Effective diffusion coefficients of both solutes in the skin and the flesh were calculated for this period using a diffusion model for a composite hollow sphere. The skin effective diffusion coefficients for both solutes ranged from entre 8,27x10-14- m2/s to 4,04x10-13 m2/s. The flesh coefficients varied from 2,92x10-9 m2/s to 3,99x10-9 m2/s for sodium chloride and from 9,76x10-11 m2/s to 2,22x10-10 m2/s for reducing sugars.Aceitunas verdes variedad Arauco fueron tratadas con soluciones de hidróxido de sodio al 2,5%. Estas fueron luego sometidas a dos procesos de lavado con agua corriente. Posteriormente, las aceitunas fueron curadas en salmueras con concentraciones de 7%, 10% y 13% de cloruro de sodio. Durante este proceso de curado, se cuantificó la pérdida de azúcares reductores desde, y la difusión de cloruro de sodio hacia el interior de las aceitunas. Durante este período se calcularon los coeficientes efectivos de difusión de ambos solutos en la piel y la pulpa, utilizando un modelo de difusión en una esfera hueca compuesta. Los coeficientes efectivos de difusión de ambos solutos en la piel estuvieron en un rango entre 8,27x10-14- m2/s y 4,04x10-13 m2/s. Los coeficientes de la pulpa variaron entre 2,92x10-9 m2/s y 3,99x10-9 m2/s para el cloruro de sodio, y entre 9,76x10-11 m2/s y 2,22x10-10 m2/s para los azúcares reductores

High body adiposity drives glucose intolerance and increases cardiovascular risk in normoglycemic subjects

Objective: We aimed to assess the utility of the 2 - hour oral glucose tolerance test (OGTT) value to discriminate between different cardiometabolic profiles and examine the role of body composition to predict the associated increased risk for glucose impairment, beta cell dysfunction and cardiovascular disease. Methods: Subjects with normal fasting glucose (NFG) completed a 2 - h OGTT and were categorized to the carbohydrate metabolism alterations (CMA) or contro l group based upon a 2 - h glucose threshold of 7.8 mmol l - 1 . Body composition, visceral adipose tissue, OGTT - based parameters and cardiovascular risk factors (CVRF) such as hypertension, dyslipidemia, obstructive sleep apnea, non - alcoholic fatty liver disea se and smoking status, were measured. Results: Subjects with CMA exhibited a significantly higher 1 - h postload glucose, greater decline in beta cell function and CVRF profile. After multivariate adjustment, excess of total body and visceral fat was associ ated with an increased risk of CMA, - cell dysfunction, CVRF and a lower whole - body insulin sensitivity. Conclusions: These data support the ethiopathogenic role of body and visceral fat in the development of glucose derangements and CVRF early on in the metabolic dysregulation process. Thus, body composition analysis and OGTT assessment performed in individuals with NFG enables a better identification of patients at risk of developing type 2 diabetes and cardiovascular disease

Tuning and mechanistic insights of metal chalcogenide molecular catalysts for the hydrogen-evolution reaction

The production of hydrogen through water splitting using earth-abundant metal catalysts is a promising pathway for converting solar energy into chemical fuels. However, existing approaches for fine stoichiometric control, structural and catalytic modification of materials by appropriate choice of earth abundant elements are either limited or challenging. Here we explore the tuning of redox active immobilised molecular metal-chalcoxide electrocatalysts by controlling the chalcogen or metal stoichiometry and explore critical aspects of the hydrogen evolution reaction (HER). Linear sweep voltammetry (LSV) shows that stoichiometric and structural control leads to the evolution of hydrogen at low overpotential with no catalyst degradation over 1000 cycles. Density functional calculations reveal the effect of the electronic and structural features and confer plausibility to the existence of a unimolecular mechanism in the HER process based on the tested hypotheses. We anticipate these findings to be a starting point for further exploration of molecular catalytic systems