The Effect of Flavonoid Naringenin on Contractile Response of Thoracic Aorta Isolated from Diabetic Rats

Abstract: Background & Aims: Considering increasing incidence of cardiovascular disorders in diabetes mellitus and some evidence on antioxidant and antidiabetic potentials of naringenin, this study was conducted to evaluate the beneficial effects of 6-week administration of naringenin on contractile reactivity of isolated thoracic aorta in diabetic rats. Methods: Male Wistar rats were divided into control, naringenin-treated control, diabetic and glibenclamide-treated, and naringenin-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was administered (60 mg/Kg). Naringenin (10 mg/kg) was administered i.p. one week after diabetes induction in every other day intervals for 6 weeks. Serum glucose level was measured before naringenin administration and at 6th week. Finally, contractile reactivity of thoracic aortic rings to KCl and phenylephrine (PE) was cumulatively determined. Results: Serum glucose level at week 6 showed a significant decrease in naringenin-treated diabetic group compared to diabetics (P<0.01). In addition, naringenin-treated diabetic group showed a significantly lower contraction to PE (P<0.05) as compared to diabetic group and such significant reduction was also observed for KCl (P<0.05). Meanwhile, there was also a significant difference between control and naringenin-treated control groups regarding their contractile reactivity to PE (P<0.05). Conclusion: Subchronic administration of naringenin for 6 weeks could exert an anti-hyperglycemic effect and lowers contractile responsiveness of thoracic aorta rings to KCl and phenylephrine. Keywords: Naringenin, Diabetes mellitus, Aorta, Contractilit

Optical and photoelectronic properties of a new material:Optoelectronic application

With the aim of studying the optical, electrochemical, and electronic properties of a new porphyrin-based material, we have synthesized a new porphyrinic complex, namely the (4,4$^{\prime}$-bipyridine)(meso-tetratrifluoromethylphenylporphyrinato)zinc(II) 4,4$^{\prime}$-bipyridine disolvate dihydrate complex with the formula [Zn(TFMPP)(4,4$^{\prime}$-bipy)]${\cdot }$2(4,4$^{\prime}$-bipy)${\cdot }$2H2O (I). This species is characterized by single-crystal X-ray molecular structure. The optical study is performed by UV–visible absorption and fluorescence spectroscopy. The fluorescence intensity presents an emission in the UV–visible range, indicating that this compound can be used as an optoelectronic material. The optical energy gap is 1.95 eV, and the current–voltage characteristics and impedance spectroscopy measurements have been studied to define the electronic properties of the zinc (II) porphyrin complex. The barrier height ${\phi }_{\mathrm{b}}$ is calculated, and the space-charge limited current mechanism is found to control the conductance. The results from the electronic study confirm that our porphyrin derivative can be used for various optoelectronic applications

Avoiding BBN Constraints on Mirror Models for Sterile Neutrinos

We point out that in models that explain the LSND result for neutrino oscillation using the mirror neutrinos, the big bang nucleosynthesis constraint can be avoided by using the late time phase transition that only helps to mix the active and the sterile neutrinos. We discuss the astrophysical as well as cosmological implications of this proposal.Comment: 5 pages, latex; more discussion added; results unchange

Enhanced production of poly (3-hydroxybutyrate-co-4-hydroxybutyrate) copolymer with manipulated variables and its properties

Cupriavidus sp. USMAA1020, a local isolate was able to biosynthesis poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3HB-co-4HB)] copolymer with various 4HB precursors as the sole carbon source. Manipulation of the culture conditions such as cell concentration, phosphate ratio and culture aeration significantly affected the synthesis of P(3HB-co-4HB) copolymer and 4HB composition. P(3HB-co-4HB) copolymer with 4HB compositions ranging from 23 to 75 mol% 4HB with various mechanical and thermal properties were successfully produced by varying the medium aeration. The physical and mechanical properties of P(3HB-co-4HB) copolymers were characterized by NMR spectroscopy, gel-permeation chromatography, tensile test, and differential scanning calorimetry. The number-average molecular weights (M (n)) of copolymers ranged from 260 x 10(3) to 590 x 10(3)Da, and the polydispersities (M (w)/M (n)) were between 1.8 and 3.0. Increases in the 4HB composition lowered the molecular weight of these copolymers. In addition, the increase in 4HB composition affected the randomness of copolymer, melting temperature (T (m)), glass transition temperature (T (g)), tensile strength, and elongation to break. Enzymatic degradation of P(3HB-co-4HB) films with an extracellular depolymerase from Ochrobactrum sp. DP5 showed that the degradation rate increased proportionally with time as the 4HB fraction increased from 17 to 50 mol% but were much lower with higher 4HB fraction. Degradation of P(3HB-co-4HB) films with lipase from Chromobacterium viscosum exhibited highest degradation rate at 75 mol% 4HB. The biocompatibility of P(3HB-co-4HB) copolymers were evaluated and these copolymers have been shown to support the growth and proliferation of fibroblast cells

DIRA system architecture : from acoustics to linguistics

This article describes the architecture and the operation of the DIRA (Integrated Dialogue and Automatic Recognition) continuous speech recognition system in its present stage of development . The DIRA system is a supervised multi-expert system . The supervisor dynamically arranges the tasks of its expert modules, which are each attached to one of the subdomains of the speech recognition problem, i .e. the acoustic/phonetic, the lexical-, the syntactic/semantic-, the prosodie- and ftnally the pragmatic domain . A blackboard serves as message interchange medium between these expert modules, as well as long-terra memory for the speech recognition process as a whole . The supervisor is an opportunistic planner : it reasons on the data present ai the blackboard and « calculâtes » the best strategy (a scheme for the activation the expert modules) to resolve the carrent problem . The operation of the individual expert modules is also addressed in this article : the APD's (Acoustic-Phonetic Decoders) with their knowledge bases represented as rules controlling the transitions in ATN's (Augmented Transition Networks), the linguistic analyzers using the same A TN concept and the principle of functional lexical grammars, the comprehensive analyzer founded on the principle of lexical priming and ftnally the rulebased prosodie analyzer . The operation of the speech recognition system is commented, while providing examples and test results .Cet article décrit l'architecture et le fonctionnement du système de reconnaissance de la parole DIRA (DIRA : Dialogue Intégré et Reconnaissance Automatique) dans son état actuel. Ce système est un système multi-experts supervisé . Le superviseur organise les tâches de ses experts qui sont attachés aux diverses sources de connaissances : acousticophonétiques, lexicales, syntaxico-sémantiques, prosodiques et pragmatiques . Le tableau noir sert de boîte à lettre pour la communication de messages entre les divers modules ainsi que de mémoire à long terme où toutes les hypothèses en cours de construction sont consignées . Le superviseur est un planificateur opportuniste : il raisonne sur les données présentes dans le tableau noir et « calcule » la stratégie la meilleure pour activer les experts. Les experts sont également décrits dans cet article : les DAP (décodages acoustico-phonétiques) avec leurs bases de connaissance représentées sous forme de règles qui contrôlent les transitions d'un ATN (Augmented Transition Network), les analyseurs linguistiques utilisant aussi le concept d'ATN compilé et la notion de grammaire lexicale fonctionnelle, la compréhension fondée essentiellement sur le phénomène d'amorçage sémantique et enfin l'analyseur prosodique à base de règles . La mise en ouvre de ce système est commentée à travers des exemples et les résultats de reconnaissance sont discutés

Hyaluronic acid of low molecular weight triggers the invasive “hummingbird” phenotype on gastric cancer cells

The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layerâ byâ layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HAâ rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the â hummingbirdâ morphology, promote high cellular motility, and activate signaling pathways with increased expression of pâ ERK1/2 and pâ AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.The authors acknowledge the financial support from the European Commission’s H2020 Programme, under grant agreements H2020-WIDESPREAD-2014-668983-FORECAST and H2020-MSCA-RISE-2019-872648-MEPHOS. S.A. acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD grant (SFRH/BD/112075/2015). The authors also thank Ramon Novoa-Caballal for performing the GPC experiments and data analysis

Lowering solar mixing angle in inverted hierarchy without charged lepton corrections

In the present work, the inverted hierarchical neutrino mass model which is characterised by opposite CP parity in the first two mass eigenvalues $(m_1,-m_2,m_3)$, is studied in order to lower the predicted value of solar mixing angle $\tan^2\theta_{12}$, from the tri-bimaximal mixing (TBM), without sacrificing the conditions of maximal atmospheric mixing angle and zero reactor angle. The present attempt is different from the earlier approach where the correction from the charged lepton mass matrix is included in the leptonic mixing matrix to lower the prediction on solar mixing angle. The lowering of the solar mixing angle without charged lepton correction, can be obtained through the variation of the input value of a flavour twister term present in the texture of neutrino mass matrix having a 2-3 symmetry. The present analysis agrees with the latest experimental bounds on neutrino mass parameters and also represents an important result on the survival of the inverted hierarchical neutrino mass models having opposite CP parity in the first two eigenvalues.Comment: 10 pages, two figures. Accepted for publication in Journal of Physics G:Nuclear and Particle Physic