A study on laminar motion of a viscous incompressible fluid between two parallel eccentric cylinders

The flow of incompressible viscous fluid between two eccentric cylinders under the action of a difference between the pressures imposed at the ends of the cylinders is analyzed. Using bipolar coordinates, the resulting boundary value problem is solved analytically, and the average flux velocity is calculated for various values of the geometric parameters of the problem.     

Antimutagenic,Cytoprotective and Antioxidant Properties of Ficus deltoidea Aqueous Extract In Vitro

Ficus deltoidea var. deltoidea is used as traditional medicine for diabetes, inflammation, and nociception. However, the antimutagenic potential and cytoprotective effects of this plant remain unknown. In this study, the mutagenic and antimutagenic activities of F. deltoidea aqueous extract (FDD) on both Salmonella typhimurium TA 98 and TA 100 strains were assessed using Salmonella mutagenicity assay (Ames test). Then, the cytoprotective potential of FDD on menadione-induced oxidative stress was determined in a V79 mouse lung fibroblast cell line. The ferric-reducing antioxidant power (FRAP) assay was conducted to evaluate FDD antioxidant capacity. Results showed that FDD (up to 50 mg/mL) did not exhibit a mutagenic effect on either TA 98 or TA 100 strains. Notably, FDD decreased the revertant colony count induced by 2-aminoanthracene in both strains in the presence of metabolic activation (p < 0.05). Additionally, pretreatment of FDD (50 and 100 µg/mL) demonstrated remarkable protection against menadione-induced oxidative stress in V79 cells significantly by decreasing superoxide anion level (p < 0.05). FDD at all concentrations tested (12.5–100 µg/mL) exhibited antioxidant power, suggesting the cytoprotective effect of FDD could be partly attributed to its antioxidant properties. This report highlights that F. deltoidea may provide a chemopreventive effect on mutagenic and oxidative stress inducers.     

Dry state preparation of radioiodine labeled meta-iodobenzylguanidine

Radioiodination of meta-iodobenzylguanidine (MIBG) by the isotopic exchange technique in the dry state has been performed. Benzoic acid, pivalic acid and acetamide have been used as molten protic media to promote isotopic exchange reactions. Ammonium sulphate, diammonium hydrogen ortho-phosphate and ammonium chloride were used as catalysts which provide acidic media to facilitate exchange reactions. Maximum radiochemical yields of 97.1±1.3% and 84.3±1.6% [¹³¹I] MIBG were obtained when ammonium sulphate and benzoic acid were used. High radiochemical yields of 88.3±1.1% and 74.4±1.5% [¹³¹I] MIBG were also obtained in case of diammonium hydrogen orthophosphate and pivalic acid which suggests their successful use as reaction media in the radioiodination of MIBG. The activation energy for the exchange reaction in ammonium sulphate was calculated to be 10.8 kcal/mole.     

An image encryption scheme based on a new hybrid chaotic map and optimized substitution box

Nonlinear Dynamics - This paper proposes a new hybrid chaotic map and a different way of using optimization technique to improve the performance of encryption algorithms. Compared to other chaotic...     

Simultaneous Hydrodistillation-Steam Distillation of Rosmarinus officinalis,Lavandula angustifolia and Citrus aurantium from Morocco,Major Terpenes: Impact on Biological Activities

Interest in the use of essential oils (EOs) in the biomedical and food industries have seen growing over the last decades due to their richness in bioactive compounds. The challenges in developing an EO extraction process that assure an efficient levels of monoterpenes with impact on biological activities have driven the present study, in which the EO extraction process of rosemary, lavender and citrus was performed by simultaneous hydrodistillation–steam distillation, and the influence of EO composition on biological activities, namely antioxidant, anti-inflammatory, antidiabetic, anti-acetylcholinesterase, anti-tyrosinase, antibacterial, and antibiofilm activity, were evaluated. The EO yields of combinations were generally higher than the individual plants (R. officinalis (Ro), L. angustifolia (La), and C. aurantium (Ca)) extracted by the conventional hydrodistillation. The EOs obtained by this process generally had a better capacity for scavenging the free radicals, inhibiting α-glucosidase, and acetylcholinesterase activities than the individual EOs. The combination of EOs did not improve the ability for scavenging peroxide hydrogen or the capacity for inhibiting lipoxygenase activity. The antioxidant activity or the enzyme inhibition activity could not only be attributed to their major compounds because they presented lower activities than the EOs. The chemical composition of the combination Ro:La:Ca, at the ratio 1/6:1/6:2/3, was enriched in 1,8-cineole, linalool, and linalyl acetate and resulted in lower MIC values for all tested strains in comparison with the ratio 1/6:2/3:1/6 that was deprived on those components. The biofilm formation of Gram positive and Gram negative bacteria was impaired by the combination Ro:La:Ca at a sub-inhibitory concentration.     

Image quality assessment using the singular value decomposition theorem

In objective image quality metrics, one of the most important factors is the correlation of their results with the perceived quality measurements. In this paper, a new method is presented based on comparing between the structural properties of the two compared images. Based on the mathematical concept of the singular value decomposition (SVD) theorem, each matrix can be factorized to the products of three matrices, one of them related to the luminance value while the two others show the structural content information of the image. A new method to quantify the quality of images is proposed based on the projected coefficients and the left singular vector matrix of the disturbed image based on the right singular vector matrix of the original image. To evaluate this performance, many tests have been done using a widespread subjective study involving 779 images of the Live Image Quality Assessment Database, Release 2005. The objective results show a high rate of correlation with subjective quality measurements.     

Comparison of thermally and chemically reduced graphene oxides by thermal analysis and Raman spectroscopy

Journal of Thermal Analysis and Calorimetry - In this paper, a numerical simulation of jet impingement quenching is provided. The VOF method in the basic solver of the OpenFOAM CFD package is...     

Effect of isolation method on the properties of nanocellulose: a meta-analysis

Cellulose - There have been many kinds of research about nanocellulose isolation and its characterization. However, there are gaps in quantitative conclusion according to previous findings about...     

Surface plasmon mapping of dumbbell-shaped gold nanorods: the effect of silver coating

We report on the identification of surface plasmons in individual gold dumbbell-shaped nanoparticles (AuDBs), as well as AuDBs coated with silver. We use spatially resolved electron energy-loss spectroscopy in a scanning electron microscope, which allows us to map plasmon-energy and intensity spatial distributions. Two dominant plasmon resonances are experimentally resolved in both AuDBs and silver-coated AuDBs. The intensity of these features is peaked either at the tips or at the sides of the nanoparticles. We present boundary element method simulations in good agreement with the experiment, allowing us to elucidate the nature of such modes. While the lower-energy, tip-focused plasmon is of longitudinal character for all dumbbells under consideration, the second side-bound plasmon has a more involved symmetry, starting as a longitudinal quadrupole in homogeneous AuDBs and picking up transversal components when silver coating is added. The longitudinal dipolar mode energy is found to blue-shift upon coating with silver. We find that the substrate produces sizable shifts in the plasmons of silver-coated AuDBs. Our analysis portraits a complex plasmonic scenario in metal nanoparticles coated with silver, including a transition from the original homogeneous gold dumbbell plasmons to the modes of homogeneous silver rods. We believe that these findings can have potential application to plasmon engineering.