826 research outputs found

    Differential Geometry of the q-plane

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    Hopf algebra structure on the differential algebra of the extended qq-plane is defined. An algebra of forms which is obtained from the generators of the extended qq-plane is introduced and its Hopf algebra structure is given.Comment: 9 page

    Numerical Investigation of Ohmic Heating in Channel Flow

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    Heat generation by direct electric conduction (ohmic heating) in a fully developed channel flow was studied to evaluate interaction between the hydrodynamic, electric and the thermal phenomena involved under the effect of natural convection. The equations governing the system were solved numerically by CFD finite volume code (FLUENT6.1 software package). The velocity profiles accelerate more near the wall than at the center that makes the temperature distribution uniform in the channel span. The numerical model is validated with an earlier experimental study [El Moctar et all. 1996] and yielded good agreement

    Response of FBG-bonded graphene plate at different applied stress location

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    In this study, the response of a FBG-bonded-graphene plate at different applied stress location is demonstrated. The sensing element utilized for this purpose is a 35.9-mm FBG sensor bonded onto the surface of a graphene plate. The lateral displacement is changed with corresponding increase or decrease in the FBG’s curvature. The change in center wavelength of the reflected spectrum is almost linear, without a significant hysteresis effect. It was also observed that the sensitivity of the FBG changes for location of applied stress. Likewise, the area under the reflection curve is observed to increase with increase in strain level, indicating an increase total power reflected. This is verified by an increase in the voltage output as observed from the oscilloscope

    Optimal multi-period consumption and investment with short-sale constraints

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    Cataloged from PDF version of article.This article examines agents’ consumption-investment problem in a multi-period pure exchange economy where agents are constrained with the short-sale of state-dependent risky contingent claims. In equilibrum, agents hold options written on aggregate consumption in their optimal portfolios. Furthermore, under the specific case of quadratic utility, the optimal risk-sharing rule derived for the pricing agent leads to a multifactor conditional consumption-based capital asset pricing model (CCAPM), where excess option returns appear as factors. 2013 Elsevier Inc. All rights reserved

    Ethnopharmacology, Antimicrobial Potency, and Phytochemistry of African Combretum and Pteleopsis Species (Combretaceae): A Review

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    Bacterial and fungal resistance to antibiotics is of growing global concern. Plants such as the African Combretum and Pteleopsis species, which are used in traditional medicine for the treatment of infections, could be good sources for antimicrobial extracts, drug scaffolds, and/or antibiotic adjuvants. In African countries, plant species are often used in combinations as traditional remedies. It is suggested that the plant species enhance the effects of each other in these combination treatments. Thus, the multi-species-containing herbal medications could have a good antimicrobial potency. In addition, plant extracts and compounds are known to potentiate the effects of antibiotics. The objective of this review is to compile the information on the botany, ethnopharmacology, ethnobotany, and appearance in herbal markets of African species of the genera Combretum and Pteleopsis. With this ethnobotanical information as a background, this review summarizes the information on the phytochemistry and antimicrobial potency of the extracts and their active compounds, as well as their combination effects with conventional antibiotics. The databases used for the literature search were Scopus, Elsevier, EBSCOhost, PubMed, Google Scholar, and SciFinder. In summary, a number of Combretum and Pteleopsis species were reported to display significant in vitro antibacterial and antifungal efficacy. Tannins, terpenes, flavonoids, stilbenes, and alkaloids—some of them with good antimicrobial potential—are known from species of the genera Combretum and Pteleopsis. Among the most potent antimicrobial compounds are arjunglucoside I (MIC 1.9 ”g/mL) and imberbic acid (MIC 1.56 ”g/mL), found in both genera and in some Combretum species, respectively. The in vitro antimicrobial properties of the extracts and compounds of many Combretum and Pteleopsis species support their traditional medicinal uses

    Anti-Candida Activity of Extracts Containing Ellagitannins, Triterpenes and Flavonoids of Terminalia brownii, a Medicinal Plant Growing in Semi-Arid and Savannah Woodland in Sudan

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    Various parts of Terminalia brownii (Fresen) are used in Sudanese traditional medicine against fungal infections. The present study aimed to verify these uses by investigating the anti-Candida activity and phytochemistry of T. brownii extracts. Established agar diffusion and microplate dilution methods were used for the antifungal screenings. HPLC-DAD and UHPLC/QTOF-MS were used for the chemical fingerprinting of extracts and for determination of molecular masses. Large inhibition zones and MIC values of 312 ”g/mL were obtained with acetone, ethyl acetate and methanol extracts of the leaves and acetone and methanol extracts of the roots. In addition, decoctions and macerations of the leaves and stem bark showed good activity. Sixty compounds were identified from a leaf ethyl acetate extract, showing good antifungal activity. Di-, tri- and tetra-gallotannins, chebulinic acid (eutannin) and ellagitannins, including an isomer of methyl-(S)-flavogallonate, terflavin B and corilagin, were detected in T. brownii leaves for the first time. In addition, genipin, luteolin-7-O-glucoside, apigenin, kaempferol-4’-sulfate, myricetin-3-rhamnoside and sericic acid were also characterized. Amongst the pure compounds present in T. brownii leaves, apigenin and ÎČ-sitosterol gave the strongest growth inhibitory effects. From this study, it was evident that the leaf extracts of T. brownii have considerable anti-Candida activity with MIC values ranging from 312 to 2500 ”g/mL

    Investigating the Role of Metoclopramide and Hyoscine-N-Butyl Bromide in Colon Motility

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    Metoclopramide is a treatment for gastroenteritis accompanied by vomiting. Hyoscine-n-butyl bromide as an anticholinergic agent causes inhibition of the acetylcholine (Ach) by acting on muscarinic receptors. The study aims to ascertain how metoclopramide affects Ach-induced cortical motility and also investigates the effects of metoclopramide alone and in combination with hyoscine-n-butyl bromide drug effects on colon motility. In this study, 1 cm of colon tissue width was cut, 2 cm long strips were made, and both sides of the tissue were secured with surgical silk at both ends of isolated bath tissues of isolated organs with (1g) tension to the suspended instrument that recorded isometric contractions. Tissue fixation is followed by drug addiction: Ach, metoclopramide, and hyoscine-N-butyl bromide. The tissue was treated with metoclopramide and hyoscine-n-butyl bromide and excess Caine for 10 min. The results show changes in colon frequency, peak-to-peak, and amplitude levels for metoclopramide, hyoscine-N-butyl, and metoclopramide and hyoscine. Apaired T-test statistically analyzes the results. Metoclopramide by itself, as well as in combination with hyoscine-n-butyl bromide, increases colon motility and induces Ach release. In addition, an analysis of the physicochemical characteristics of hyoscine-n-butyl bromide and metoclopramide molecules is conducted. The study includes theoretical calculations of electronic parameters for both protonated and unprotonated forms of these molecules in both gaseous and aqueous environments. These results show the potential use of metoclopramide as a therapeutic option for gastroenteritis with vomiting, warranting additional study, and clinical evaluation. The research also reveals hyoscine-n-butyl bromide and metoclopramide’s molecular features by their physicochemical properties

    On the Differential Geometry of GLq(1∣1)GL_q(1| 1)

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    The differential calculus on the quantum supergroup GLq(1∣1)_q(1| 1) was introduced by Schmidke {\it et al}. (1990 {\it Z. Phys. C} {\bf 48} 249). We construct a differential calculus on the quantum supergroup GLq(1∣1)_q(1| 1) in a different way and we obtain its quantum superalgebra. The main structures are derived without an R-matrix. It is seen that the found results can be written with help of a matrix R^\hat{R}Comment: 14 page
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