Aqueous fraction of Nephelium ramboutan-ake rind induces mitochondrial-mediated apoptosis in HT-29 human colorectal adenocarcinoma cells

The aim of this study was to investigate the cytotoxic and apoptotic effects of Nephelium ramboutan-ake (pulasan) rind in selected human cancer cell lines. The crude ethanol extract and fractions (ethyl acetate and aqueous) of N. ramboutan-ake inhibited the growth of HT-29, HCT-116, MDA-MB-231, Ca Ski cells according to MTT assays. The N. ramboutan-ake aqueous fraction (NRAF) was found to exert the greatest cytotoxic effect against HT-29 in a dose-dependent manner. Evidence of apoptotic cell death was revealed by features such as chromatin condensation, nuclear fragmentation and apoptotic body formation. The result from a TUNEL assay strongly suggested that NRAF brings about DNA fragmentation in HT-29 cells. Phosphatidylserine (PS) externalization on the outer leaflet of plasma membranes was detected with annexin V-FITC/PI binding, confirming the early stage of apoptosis. The mitochondrial permeability transition is an important step in the induction of cellular apoptosis, and the results clearly suggested that NRAF led to collapse of mitochondrial transmembrane potential in HT-29 cells. This attenuation of mitochondrial membrane potential (Δψm) was accompanied by increased production of ROS and depletion of GSH, an increase of Bax protein expression, and induced-activation of caspase-3/7 and caspase-9. These combined results suggest that NRAF induces mitochondrial-mediated apoptosis.     

Catalytic methanation reaction over alumina supported cobalt oxide doped noble metal oxides for the purification of simulated natural gas

A series of alumina supported cobalt oxide based catalysts doped with noble metals such as ruthenium and platinum were prepared by wet impregnation method.The variables studied were difference ratio and calcination temperatures.Pt/Co(10∶90)/Al2O3 catalyst calcined at 700 ℃ was found to be the best catalyst which able to convert 70.10% of CO2 into methane with 47% of CH4 formation at maximum temperature studied of 400 ℃.X-ray diffraction analysis showed that this catalyst possessed the active site Co3O4 in face-centered cubic and PtO2 in the orthorhombic phase with Al2O3 existed in the cubic phase.According to the FESEM micrographs,both fresh and spent Pt/Co(10∶90)/Al2O3 catalysts displayed small particle size with undefined shape.Nitrogen Adsorption analysis showed that 5.50% reduction of the total surface area for the spent Pt/Co(10∶90)/Al2O3 catalyst.Meanwhile,Energy Dispersive X-ray analysis(EDX) indicated that Co and Pt were reduced by 0.74% and 0.14% respectively on the spent Pt/Co(10∶90)/Al2O3catalyst.Characterization using FT-IR and TGA-DTA analysis revealed the existence of residual nitrate and hydroxyl compounds on the Pt/Co(10∶90)/Al2O3 catalyst.     

Rapid Crystallization of L-Alanine on Engineered Surfaces using Metal-Assisted and Microwave-Accelerated Evaporative Crystallization

This study demonstrates the application of metal-assisted and microwave-accelerated evaporative crystallization (MA-MAEC) technique to rapid crystallization of L-alanine on surface engineered silver nanostructures. In this regard, silver island films (SIFs) were modified with hexamethylenediamine (HMA), 1-undecanethiol (UDET), and 11-mercaptoundecanoic acid (MUDA), which introduced -NH(2), -CH(3) and -COOH functional groups to SIFs, respectively. L-Alanine was crystallized on these engineered surfaces and blank SIFs at room temperature and using MA-MAEC technique. Significant improvements in crystal size, shape, and quality were observed on HMA-, MUDA- and UDET-modified SIFs at room temperature (crystallization time = 144, 40 and 147 min, respectively) as compared to those crystals grown on blank SIFs. Using the MA-MAEC technique, the crystallization time of L-alanine on engineered surfaces were reduced to 17 sec for microwave power level 10 (i.e., duty cycle 100%) and 7 min for microwave power level 1 (duty cycle 10%). Raman spectroscopy and powder x-ray diffraction (XRD) measurements showed that L-Alanine crystals grown on engineered surfaces using MA-MAEC technique had identical characteristic peaks of L-alanine crystals grown using traditional evaporative crystallization.     

Equilibrium, kinetics and thermodynamic aspects of Promethazine hydrochloride sorption by iron rich smectite

Equilibrium, kinetics and thermodynamic aspects of sorption of Promethazine hydrochloride (PHCl) onto iron rich smectite (IRS) from aqueous solution were investigated. The effect of pH on sorption of PHCl onto IRS was also found out. Experimental data were evaluated by using Langmuir, Freundlich and Dubinin–Raduschkevich (DR) isotherm equations. Freundlich and DR equations provided better compatibility than Langmuir equation. Besides, it was determined that the maximum sorption of PHCl takes place at about pH 5. From kinetic studies, it was obtained that sorption kinetics follow pseudo-second-order kinetic model for PHCl sorption onto IRS. When thermodynamic studies are concerned, the values of activation energy (E_a), ΔG°, ΔH° and ΔS° were obtained. ΔG° values are in the range of −8.84 and −9.45 kJ mol⁻¹ indicating spontaneous nature of physisorption. The negative value of the ΔH° (−3.20 kJ mol⁻¹) indicates exothermic nature of adsorption. FTIR analysis and SEM observations of IRS and PHCl adsorbed IRS were also carried out. Sorption experiments indicate that IRS may be used effectively for the adsorption of PHCl.     

Microwave-Accelerated Metal-Enhanced Fluorescence (MAMEF): Application to Ultra Fast and Sensitive Clinical Assays

In this rapid communication we describe an exciting platform technology that promises to fundamentally address two underlying constraints of modern assays and immunoassays, namely sensitivity and rapidity. By combining the use of Metal-enhanced Fluorescence (MEF) with low power microwave heating (Mw), we can significantly increase the sensitivity of surface assays as well as >95% kinetically complete the assay within a few seconds. This technology is subsequently likely to find significant importance in certain clinical assays, such as in the clinical assessment of myoglobin, where both the assay rapidity and sensitivity are paramount for the assessment and treatment of acute myocardial infarction.     

Conformational stability of the tetrameric de novo designed hexcoil-Ala helical bundle

We have performed molecular dynamics method to investigate the conformational stability of the homotetramer form of HexCoil-Ala (PDB Code 3S0R). The previous experiments showed that the chains tend to form tetramer structures. The system was simulated in explicit water model at several temperatures by using isobaric-isothermal ensemble to better understand the behaviour of each monomer and its tetramer form. It was observed that central residues of each monomer have highly helical percentages in comparison with the termini residues. As the temperature increased, these percentages decreased, and bend-like configurations came into being due to the fact that the C-and N-terminals of the monomer were getting closer. When free energy landscapes of HexCoil-Ala were calculated by using the distance between Leu-Zipper and Ala-Coil interface, it was seen that the assemblies of monomers were very strong. What's more, the average values obtained from them were very close to the native case between 300?K and 350?K. It was also observed that the direct salt bridge forming between the residues E8 with R25 in the other chains plays a significant role for keeping tetramer structure. Consequently, our results are in better agreement with the results of experimental observations.     

Anisotropic slip magneto-bioconvection flow from a rotating cone to a nanofluid with Stefan blowing effects

A mathematical model for two dimensional steady laminar natural convective anisotropic slip boundary layer flows from a rotating vertical cone embedded in ethylene glycol bionanofluid is presented. The influence of Stefan blowing is also taken into account. Four different non-particles namely Copper (Cu), Alumina (Al₂O₃), Copper Oxide (Cuo), Titanium Oxide (TiO₂) are explored. Suitable similarity transformations are used to convert the governing equations into non-linear ordinary differential equations. These are then solved numerically, with appropriate boundary conditions, utilizing an implicit finite difference method (the BVP5C code in MATLAB). During computation Sc, Lb, Le and Lb are presented as unity, whilst $\mathrm{Pr}$ is taken as 151. The effects of the governing parameters on the dimensionless velocities, temperature, nanoparticle volume fraction, density of motile microorganisms as well as on the local skin friction, local Nusselt, Sherwood number and motile micro-organism number density are thoroughly examined via tables and graphs. It is found that the skin friction factor increases with tangential slip, magnetic field and Schmidt number whilst it decreases with blowing parameter and spin parameters. It is further observed that both the friction and heat transfer rates are highest for copper nanoparticles and lowest for TiO₂nanoparticles. Validation of the BVP5C numerical solutions with published results for several special cases of the general model is included. The study is relevant to electro-conductive bio-nano-materials processing.     

Biopolymeric electrolyte based on glycerolized methyl cellulose with NH<Subscript>4</Subscript>Br as proton source and potential application in EDLC

In the present work, biopolymer electrolyte films based on MC doped with NH₄Br salt and plasticized with glycerol were prepared by solution casting method. Fourier transform infrared (FTIR) spectroscopy analysis confirms the interaction between MC, NH₄Br, and glycerol. X-ray diffraction (XRD) explains that the enhancement of conductivity is affected by the degree of crystallinity. This result is verified by field emission scanning electron microscopy (FESEM). For unplasticized system, sample containing 25 wt% of NH₄Br possesses the highest ionic conductivity of (1.89 ± 0.05) × 10^?4 S cm^?1. The addition of 30 wt% glycerol increases the conductivity value up to (1.67 ± 0.04) × 10^?3 S cm^?1. The conduction mechanism was best presented by the correlated barrier hopping (CBH) model. The linear sweep voltammetry (LSV) and cyclic voltammetry (CV) result confirms the suitability of the highest conducting electrolyte to be employed in the fabrication of electrochemical double layer capacitor (EDLC).     

A chaotic image encryption algorithm based on perceptron model

Based on the high-dimension Lorenz chaotic system and perceptron model within a neural network, a chaotic image encryption system with a perceptron model is proposed. This paper describes the algorithm flow in detail, and analyses the cryptographic security. The experimental results show that this algorithm has high security, and strong resistance to the existing attack methods.     

Color image encryption using skew tent map and hyper chaotic system of 6th-order CNN

The paper designs a color image encryption scheme based on skew tent map and hyper chaotic system of 6th-order CNN. The essence of the image encryption is to confuse and diffuse the pixels, the skew tent map is applied to generate the confusion sequence, and the hyper chaotic system of 6th-order CNN is applied to generate the diffusion sequence, for 6 state variables in the system, there are total 120 combinations. For each pixel of the plain image, one combination is chosen to encryption the red, green and blue components, and the combination is determined by one of the state variables. Each pixel is encrypted by the cipher value of the previous pixel and the combination value of the CNN system. Experimental results and security analysis demonstrate that the scheme can achieve good encryption result and larger key space, and can resist common attacks, so the scheme can be applied in secure communication to enhance the security of transmitting image.