80 research outputs found

    Cytotoxic activities of <em>Euphorbia kopetdaghi</em> against OVCAR-3 and EJ-138 cell lines

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    Introduction: Over the centuries, the genus Euphorbia was known to be toxic to humans and animals. Recently, in a primary study significant suppressive activity against phytohemagglutinin activated T-cell proliferation has been reported from this plant. Therefore, this study was designed to evaluate the cytotoxic effects of different parts of E. kopetdaghi against cancer cell lines. Methods: Filtration and in vacuo concentration resulted in a green gum which was subjected on silica gel CC (hexane/Acetone, 0&rarr;50) to several fractions: F1-F8. The inhibitory effects of obtained fractions with 5, 50, and 500 &mu;g/ml concentrations were evaluated on proliferation and viability of cancer cells (OVCAR and EJ-138) in 48 hours treatment. Finally, cell viability was determined at a wavelength of 570 by 3-4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) method. Results: Based on studies of microscopic observation and viability testing, F1, F2, F4, F5, F6, and F7 showed significant cytotoxic effect at concentration of 50 and 500 &mu;g/ml against EJ-138 and OVCAR-3 cell lines. These fractions inhibited growth of EJ-138 and OVCAR-3 cells in a concentration-dependent manner. Fraction of F8 induced tumor promotion significantly in EJ-138 and OVCAR-3 cells, respectively. Conclusion: Due to the inhibitory properties of E. kopetdaghi extract and its fractions on cancer cells of OVCAR3 and EJ-13, isolation, purification and identification of compounds presented in the fractions possessing cytotoxic effects are recommended which were the area of our future research.</p

    On the effects of surface waviness upon catalytic steam reforming of methane in micro-structured reactors - a computational study

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    The effects of wavy channels upon steam methane reforming in catalytic micro-structured reactors, using Nickle as the catalyst, are investigated numerically. Laminar, three-dimensional models of reacting flows, with heterogeneous chemistry, are developed and applied to micro-structured reactors with different wave patterns on their internal walls. It is observed that introduction of surface waves on the walls of reactor, can significantly alter production and consumption of H2 and CH4. This is shown to be due to large fluctuations in convective mass and heat transfer, induced by the surface waviness. In particular, it is shown that separation and reattachment of concentration and thermal boundary layers and the subsequent modifications in Sherwood and Nusselt number can significantly affect the catalytic processes over the walls of reactor. A major local intensification of catalytic processes is observed where Sherwood and Nusselt number are maximised. Similarly, the catalytic process becomes highly inefficient in places with minimal Sherwood (and Nusselt) number. The analyses further reveal that a strategic discrete coating of wavy walls with the catalyst can substantially improve the performance of microstructure. For example, by coating only 25% of the surface area of wavy walls, CH4 conversion rate and selectivity per coated surface area increase by 459% and 308% compared to those of an equivalent fully coated straight channel. This implies the possibility of developing highly efficient and cost-effective catalytic micro-reactors for production of hydrogen from methane

    Effect of nanosilver particles on hatchability of rainbow trout (Oncorhynchus mykiss) egg and survival of the produced larvae

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    Effect of nanosilver particles was studied on the hatchability of rainbow trout (Oncorhynchus mykiss) egg and survival of the produced larvae at about 12ºC. In the first experiment the water-based nanosilver particles was used at concentrations of 0.5, 1, 2 and 4 mgL^-1 for 30 minutes per day starting 24 hour post egg incubation until the hatching time. The mean percentage of hatchability reached in 27.6±0.2, 38.2±0.1, 41.6±0.4 and 48.6±1.5 in troughs treated with 0.5, 1, 2 and 4 mgL^-1 nanocid, respectively compared with 64.7±0.2 % for trough treated with malachite green at 2 mgL^-1 as positive control (P0.05). These data suggest a possible application of nanosilver particles in aquaculture sector particularly using incubator troughs of trout containing nanosilver materials

    AHP approach for supplier evaluation and selection in a steel manufacturing company

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    Supplier selection is one of the most critical activities of purchasing management in supply chain. Supplier selection is a complex problem involving qualitative and quantitative multi-criteria. A trade-off between these tangible and intangible factors is essential in selecting the best supplier. The work incorporates AHP in choosing the best suppliers. The results suggest that AHP process makes it possible to introduce the optimum order quantities among the selected suppliers so that the Total Value of Purchasing (TVP) becomes maximum. In this work, an AHP-based supplier selection model is formulated and then applied to a real case study for a steel manufacturing company in Malaysia. The use of the proposed model indicates that it can be applied to improve and assist decision making to resolve the supplier selection problem in choosing the optimal supplier combination. The work represents the systematic identification of the important criteria for supplier selection process. In addition, the results exhibit the application of development of a multi-criteria decision model for evaluation and selection of suppliers with proposed AHP model, which by scoring the performance of suppliers is able to reduce the time taken to select a vendorPeer Reviewe

    Childhood neurogenic stuttering due to bilateral congenital abnormality in globus pallidus: A case report and review of the literature

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    Objective The basal ganglia are a group of structures that act as a cohesive functional unit. They are situated at the base of the forebrain and are strongly connected with the cerebral cortex and thalamus. Some speech disorders such as stuttering can resulted from disturbances in the circuits between the basal ganglia and the language motor area of the cerebral cortex. Stuttering consists of blocks, repetitive, prolongation or cessation of speech. We present a 7.5 -year-old male child with bilateral basal ganglia lesion in globus pallidus with unclear reason. The most obvious speech disorders in patient was stuttering, but also problems in swallowing, monotone voice, vocal tremor, hypersensitivity of gag reflex and laryngeal dystonia were seen. He has failed to respond to drug treatment, so he went on rehabilitation therapy when his problem progressed. In this survey, we investigate the possible causes of this type of childhood neurogenic stuttering. © 2016, Iranian Child Neurology Society. All rights reserved

    Regulatory regions of the paraoxonase 1 (PON1) gene are associated with neovascular age-related macular degeneration (AMD)

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    Physiological stress response and oxidative damage are factors for aging processes and, as such, are thought to contribute to neovascular age-related macular degeneration (AMD). Paraoxonase 1 (PON1) is an enzyme that plays an important role in oxidative stress and aging. We investigated association of DNA sequence variants (SNP) within the upstream regulatory region of the PON1 gene with neovascular AMD in 305 patients and 288 controls. Four of the seven tested SNPs (rs705379, rs705381, rs854573, and rs757158) were more frequently found in AMD patients compared to controls (P = 0.0099, 0.0295, 0.0121, and 0.0256, respectively), and all but one (SNP rs757158) are in linkage disequilibrium. Furthermore, haplotype TGGCCTC conferred protection (odds ratio (OR) = 0.76, (CI) = 0.60-0.97) as it was more frequently found in control individuals, while haplotype CGATGCT increased the risk (OR = 1.55, CI = 1.09-2.21) for AMD. These results were also reflected when haplotypes for the untranscribed and the 5'untranslated regions (5'UTR) were analyzed separately. To assess haplotype correlation with levels of gene expression, the three SNPs within the 5'UTR were tested in a luciferase reporter assay. In retinal pigment epithelium-derived ARPE19 cells, we were able to measure significant differences in reporter levels, while this was not observed in kidney-derived HEK293 cells. The presence of the risk allele A (SNP rs705381) caused an increase in luciferase activity of approximately twofold. Our data support the view that inflammatory reactions mediated through anti-oxidative activity may be relevant to neovascular age-related macular degeneration

    Role of antioxidant enzymes and small molecular weight antioxidants in the pathogenesis of age-related macular degeneration (AMD)

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    Numerical Study of Single Phase/Two-Phase Models for Nanofluid Forced Convection and Pressure Drop in a Turbulence Pipe Flow

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    In this paper, the problem of turbulent forced convection flow of water- alumina nanofluid in a uniformly heated pipe has been thoroughly investigated. In numerical study, single and two-phase models have been used. In single-phase modeling of nanofluid, thermal and flow properties of nanofluid have been considered to be dependent on temperature and volume fraction. Effects of volume fraction and Reynolds number (300

    Effect of topography on tree species composition and volume of coarse woody debris in an Oriental beech (Fagus orientalis Lipsky) old growth forests, northern Iran

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    There is an emerging interest in the relationships between forest structure and topographic aspects. Still, such patterns have been scarcely studied in undisturbed mixed beech forests in northern Iran. We investigated the influence of topographical factors including aspect, slope degree, and landform index (LI) on the distribution of dominant tree species and coarse woody debris (CWD). Tree density and basal area were not significantly correlated with any of the measured parameters, except a moderate relation between basal area and LI (r = - 0.376; P = 0.029). Redundancy analysis (RDA) of the tree layer revealed a significant relationship between the measured environmental variables and species distributions. CWD volume showed significant negative correlation with percent canopy coverage and was highly correlated with slope. Density of CWD in decay class IV was significantly correlated with aspect and percent of canopy cover. Analyses of CWD distributions in relation to both living vegetation and topographic gradients showed a highly complex interplay of factors driving the distribution of CWD across the forest stands
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