Structural Characterization of Oat Bran (1→3), (1→4)-β-D-Glucans by Lichenase Hydrolysis Through High-Performance Anion Exchange Chromatography with Pulsed Amperometric Detection

Cereal mixed linkages (1 → 3) (1 → 4)-β-D-glucan is a linear polysaccharide composed of glucose units. Oat β-glucan is a natural polymer. The main products of β-glucanase are oligosaccharides with DP3 and DP4, i.e., 3-Ob-cellobiosyl-D-glucose and 3-Ob-cellotriosyl-D-glucose, which represent over 90% of the molecule. Keeping in mind all the benefits of oat bran, the present study was planned to investigate the structural properties of oat bran, high-performance anion exchange chromatography with pulsed amperometric detection was used to examine these oligosaccharides. The structural analysis of oat bran of two oat varieties revealed that the ratio of soluble and insoluble triose to tetraose in β-glucan fraction was 1.44 and 1.78, respectively, for Avon variety; while the ratio of soluble and insoluble triose to tetraose in β-glucan fraction for Sargodha-81 was 1.49 and 1.77. The major units determined were cellotriose and cellotetraose. Other units cellopentaose and hexaoses were also existed but in minor fractions. Lichenase hydrolysis high-performance anion exchange chromatography with pulsed amperometric detection appeared to be the best choice for structural analysis of purified samples of mixed-linkage β-glucan.     

Evaluation of peanut husk as a novel,low cost biosorbent for the removal of Indosol Orange RSN dye from aqueous solutions: batch and fixed bed studies

The feasibility of using peanut husk biomass for the removal of Indosol Orange RSN dye was explored during this study. Batch experiments were conducted with native, polyethyleneimine (PEI) treated and Na-alginate immobilized biomass. Different important process parameters like pH, contact time, biosorbent dose, initial dye concentration, and temperature were optimized during batch study. Low pH and low biosorbent dose were found to be the feasible conditions for the maximum biosorption of dye. PEI-treated biomass exhibited maximum biosorption capacity (79.5 mg g^?1) for Indosol Orange RSN dye. Pseudo-second-order equation generated the best agreement with experimental data. Different equilibrium isotherm models were applied to the experimental data. Langmuir adsorption isotherm model showed better fitness to the experimental results. Biosorption process was found to be exothermic in nature and thermodynamic study was carried out to check out the feasibility of process. Continuous mode study was performed with native peanut husk biomass to optimize the bed height, flow rate, and initial dye concentration for maximum dye removal. The results indicate that maximum dye removal (8.8 mg L^?1) was obtained with 3 cm bed height and 1.8 mL min^?1 flow rate by using 70 mg L^?1 initial dye concentration. Characterization of biosorbent was carried out by determination of point of zero charge, scanning electron microscopy, and Fourier transform infrared spectroscopy. The findings revealed that peanut husk biomass has a high biosorption potential, and it can be exploited for the treatment of dye containing waste water.     

A novel trust-based access control for social networks using fuzzy systems

World Wide Web - Social networks are constantly expanding and attracting more and more users. The users of these networks share plenty of information with their friends, many of which are...     

Fabrication of novel hybrid composite La2‐xCoxCuO4 electrode for high performance supercapacitors

Hybrid composites La_2‐xCo_xCuO₄ (x = 0, 0.1, 0.2, and 0.3) are prepared using one‐step simple hydrothermal route as electrodes for supercapacitors. The effect of varying cobalt content on morphological, structural, and electrochemical properties has been explored using X‐ray diffraction, scanning electron microscopy, and cyclic voltammetry, respectively. The structural parameters obtained by X‐ray diffraction showed tetragonal phase of hybrid composite without any evident impurity phases. The analysis of morphological properties suggested a strong correlation with electrochemical properties, for instance, a relationship between fabric porous structures and electrochemically active sites for redox reactions and intercalation/de‐intercalation processes. The hybrid composite electrodes demonstrated high specific capacitance of the order of 1304 F/g at 10 mV/s scan rate and exhibited decreasing trend on increasing scan rate. Hybrid composites were also tested for their ability as an electrode of high performance supercapacitors in different aqueous electrolytes, i. e, KOH, H₂SO₄, and Na₂SO₄ to optimize the best compatible electrolyte. The composite electrode material showed excellent cyclic stability and 98% capacitance retention for 1 A/g after 2000 cycles. The remarkable performance of hybrid composite electrode entails its potential for commercial applications of supercapacitors.     

Kinetically Stable Oxide Overlayers on Mo3P Nanoparticles Enabling Lithium–Air Batteries with Low Overpotentials and Long Cycle Life

The main drawbacks of today's state-of-the-art lithium–air (Li–air) batteries are their low energy efficiency and limited cycle life due to the lack of earth-abundant cathode catalysts that can drive both oxygen reduction and evolution reactions (ORR and OER) at high rates at thermodynamic potentials. Here, inexpensive trimolybdenum phosphide (Mo₃P) nanoparticles with an exceptional activity—ORR and OER current densities of 7.21 and 6.85 mA cm⁻² at 2.0 and 4.2 V versus Li/Li⁺, respectively—in an oxygen-saturated non-aqueous electrolyte are reported. The Tafel plots indicate remarkably low charge transfer resistance—Tafel slopes of 35 and 38 mV dec⁻¹ for ORR and OER, respectively—resulting in the lowest ORR overpotential of 4.0 mV and OER overpotential of 5.1 mV reported to date. Using this catalyst, a Li–air battery cell with low discharge and charge overpotentials of 80 and 270 mV, respectively, and high energy efficiency of 90.2% in the first cycle is demonstrated. A long cycle life of 1200 is also achieved for this cell. Density functional theory calculations of ORR and OER on Mo₃P (110) reveal that an oxide overlayer formed on the surface gives rise to the observed high ORR and OER electrocatalytic activity and small discharge/charge overpotentials.     

Albumin-based biomaterial for lung tissue engineering applications

The role of albumin-based biomaterials in tissue engineering (TE) cannot be overemphasized. The authors review the role of albumin in lungs scaffold grafting, which promotes cell seeding. Albumin grafted on decellularized lungs scaffold is presented as a great support material for cell-tissue interaction as well as for ease in attachment, growth, and differentiation when seeded with different types of cells. Albumin scaffold fabrication from different sources is a promising approach that may facilitate medical treatments from bench-to-bed, although the role of this scaffold in lungs surfactant proteins regeneration and binding needs to be fully elucidated.     

Radiation dose to neonates undergoing X-ray imaging in special care baby units in Iran

Radiographic imaging has a significant role in the timely diagnosis of the diseases of neonates in intensive care units. The estimation of the dose received by the infants undergoing radiographic examination is of great importance, due to greater more radiosensitivity and longer life expectancy of the neonates and premature babies. In this study, the values of entrance skin dose (ESD), dose area products (DAPs), energy imparted (EI), whole-body dose, effective dose and risk of childhood cancer were estimated using three methods including direct method [using thermoluminescence dosimetry (TLD) chips], indirect method (using tube output) and Monte Carlo (MC) method (using MCNP4C code). In the first step, the ESD of the neonates was directly measured using TLD-100 chips. Fifty neonates, mostly premature, with different weights and gestational ages in five hospitals mostly suffering from respiratory distress syndrome and pneumonia were involved in this study. In the second step, the values of ESD to neonates were indirectly obtained from the tube output in different imaging techniques. The imaging room, incubator, neonates and other components were then simulated in order to obtain the ESD values using the MCNP4C code. Finally, the values of ESD assessed by the three methods were used for calculation of DAP, EI, whole-body dose, effective dose and risk of childhood cancer. The results indicate that the mean ESD per radiograph estimated by the direct, indirect and MC methods are 56.6±4.1, 50.1±3.1 and 54.5±3.3 μGy, respectively. The mean risk of childhood cancer estimated in this study varied between 4.21×10(-7) and 2.72×10(-6).     

Low-power and controllable memory window in Pt/Pr0.7Ca0.3MnO3/yttria-stabilized zirconia/W resistive random-access memory devices

Yttria-stabilized zirconia (YSZ) layers of various thicknesses were designed and introduced before Pr0.7Ca0.3MnO3 (PCMO) film was deposited on W bottom electrodes with a submicron via-hole structure. By changing the thickness of the YSZ barrier layer (3, 5, 9, and 13 nm), a tunable memory window can be realized while low power consumption (P(max) < 4 microW) is maintained. Resistive switching (RS) in a Pt/PCMO/YSZ/W stack with a thin YSZ layer can be ascribed to an oxidation/reduction reaction caused by a ring-type PCMO/W contact, while RS with a thick YSZ layer may be related to oxygen migration across the YSZ layer between the PCMO film and the W bottom electrode and the increase (decrease) of the effective tunnel barrier height of the YSZ layer. Excellent RS behavior characteristics, such as a large R(HRS)/R(LRS) ratio (> 10(3)), die-to-die uniformity, sweeping endurance, and a retention time of more than 10(3) s, can be obtained by optimizing the thickness of YSZ layer.     

Differences in the Relative Abundance of ProBDNF and Mature BDNF in A549 and H1299 Human Lung Cancer Cell Media

Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has been linked to several human malignancies and shown to promote tumorigenesis. The purpose of this study was to explore the relative abundance of pro-brain-derived neurotrophic factor (proBDNF) and mature BDNF (mBDNF) in A549 (p53 wild-type) and H1299 (p53-null) lung cancer cell media. Higher levels of proBDNF were detected in the media of A549 cells than in H1299 cell media. Using inhibitors, we found that the levels of proBDNF and mBDNF in the media are likely regulated by PI3K, AKT, and NFκB. However, the largest change in these levels resulted from MMP2/9 inhibition. Blocking p53 function in A549 cells resulted in increased mBDNF and decreased proBDNF, suggesting a role for p53 in regulating these levels. The ratio of proBDNF/mBDNF was not affected by MMP2 knockdown but increased in the media of both cell lines upon knockdown of MMP9. Downregulation of either MMP2 or MMP9 by siRNA showed that MMP9 siRNA treatment of either A549 or H1299 cells resulted in decreased cell viability and increased apoptosis, an effect diminished upon the same treatment with proBDNF immunodepleted media, suggesting that MMP9 regulates the cytotoxic effects induced by proBDNF in lung cancer cells.