Characterization and in vitro drug release properties of chitosan/acrylamide/gold nanocomposite prepared by gamma irradiation

A nanocomposite of (chitosan/polyacrylamide/gold) (Cs/AAm/Au) and (chitosan/polyacrylamide) (Cs/AAm) hydrogel were performed using gamma radiation and employed as a carrier for Cisplatin cancer drug. The structure and morphology were studied by FTIR and FE-SEM, respectively. XRD and TEM confirmed the formation of the nanoconposite. The average particle size ranged between 13 to 27?nm. EDX estimated that the concentration of Au⁰ nanoparticles in (Cs/AAm/Au) nanocomposite was 0.20%. Both (Cs/AAm) and (Cs/AAm/Au) have higher swelling percent and reached the swelling equilibrium within 6?h. The optimum pH of swelling was at pH 7.2. The maximum Cisplatin drug released was 33% for Cs/AAm hydrogel and 96% for Cs/AAm/Au nanocomposite at pH 7.2 through 320 and 410?min, respectively. The release mechanism was found to be followed the non-Fickian diffusion mechanism for both systems. The cytotoxicity against liver cancer (HepG2) was investigated. Cisplatin drug loaded samples (Cs/AAm) drug loaded hydrogel of concentration 100?μg/ml killed 76.4% of the cells and IC₅₀ reached 29?μg/ml whereas (Cs/AAm/Au) drug loaded nanocomposite killed 84.9 of the cells and IC₅₀ reached 22.7?μg/ml.     

Adsorption of uranium from sulfate leach liquor using rice straw impregnated with chlorophenyl hydrazinyl pyrazoloquinazolinon

The impregnation of rice straw with 2-amino-3-(2-(4-chlorophenyl)hydrazinyl)-8,8-dimethyl-8,9-dihydropyrazolo[1,5-a]quinazolin-6(7H)-one (CPHPQ) has been used for the recovery of uranium from sulfate leach liquor. The uranium adsorption and elution of solvent impregnated mercerized rice straw (SIMRS) were carried out using a batch technique. The uranium adsorption controlling factors include pH, initial uranium concentration, contact time, S/L ratio, and temperature. Thermodynamic characteristics showed that the adsorption process is exothermic with enthalpy change ΔH = ?152.1 kJ/mol. The kinetics data fit well with a pseudo-second-order model. The equilibrium data fit well with the Langmuir isotherm. Uranium cake was obtained from the eluate solution using hydrogen peroxide as UO₄.2H₂O precipitate.     

Dihydrofolate Reductase Thermosensitive (ts-dfrA) Mutant Induces Dihydrofolate Overproduction by Lactobacillus plantarum

Dihydrofolate (dihydrofolic acid, vitamin B9) is one of the principle reduced forms of folates, which is converted to tetrahydrofolate by dihydrofolate reductase (DHFR). The aim of the present study was to overproduce total folate by inducing accumulation of dihydrofolate (DHF) due to inhibition of DHFR in a thermosensitive mutant (TS) of Lactobacillus plantarum. This mutant (TS34) was obtained by UV-mutagenesis of L. plantarum wild-type parent strain (HMA07) isolated from fermented sausage. The mutant TS34 was characterized by its ability to grow at 30°C but not at 40°C. Strain HMA07 and its mutant TS34 were identified by determining partial sequence of 16S rRNA gene. A single C→T exchange in the dfrA (dihydrofolate reductase gene) at nucleotide 184 was detected. This exchange led to the conversion of leucine (L) to phenylalanine (F) at the position 62 in amino acid sequence (L62F transition). TS43 showed significant (p < 0.05) reduction in DHFR activity from 1.51 to 0.06 Unit/mg protein, resulting in increasing DHF amount at the expense of THF. Accordingly, total folate production by the mutant TS34 (in two-stage fermentation process with temperature shift-up from 30°C to 40°C) increased by three-fold compared with the parental strain HMA07. In conclusion, thermosensitive mutation in dfrA caused inhibition of DHFR and resulted in accumulation of DHF. The technique described here could be considered as novel strategy for overproduction of DHF in two-stage fermentation process.     

Antioxidant effect of Majorana syriaca extract in bulk corn oil and o/w emulsion after applying high hydrostatic pressure

Bulk oils and oil-in-water emulsions were subjected to high hydrostatic pressure (HHP) (200, 650 MPa) treatment so as to estimate the effect of applied pressures on lipid oxidation. HHP-treated and non-treated samples were left to autoxidise under accelerated conditions (2 weeks, 70 °C) and their oxidative status was periodically estimated by measurement of conjugated dienes and peroxide value. Total changes of thiobarbituric acid-reactive substances were recorded as additional oxidative markers for emulsions. Results showed an increase in oxidation as pressure was increased especially at 650 MPa. Lipid oxidation rates that were more pronounced for HHP-treated samples can be correlated to measured dissolved oxygen that was also higher. HHP did not seem to have an effect on emulsion droplet size. The addition of Majorana syriaca (200 ppm) ethyl acetate extract led to protection against lipid oxidation under HHP and atmospheric conditions, 20.9–38.7% and 28.9–43.2%, respectively. It was observed that the antioxidant effect of M. syriaca extract under HHP was weaker.     

Accelerating video encoding using cluster computing

The great advance and variety of multimedia applications such as video streaming, TV broadcasting, and video conferencing stimulated research to enhance video encoding, where a video is reduced in size and possibly transformed to numerous formats for portability. This paper is concerned with solving the problem of the huge processing time taken by the serial video encoding approaches by proposing a hybrid-parallel video encoding technique to speed up the process. In this work, the Joint Scalable Video Model (JSVM 9.19.14) is chosen as the basic serial video encoding algorithm for building different parallel video encoding architectures. The proposed technique exploits the triple-step nature of JSVM and intelligently determines the best task organization to achieve speedup and increase the efficiency on a cluster computing platform. Moreover, a dynamic load sharing scheme is proposed to redistribute load among different machines for additional parallelism. The remarkable feature of our approach is that, both the granularity of load partitioning among the cluster machines and all the associated overheads are considered. The experimental results are applied on a compact library of 160 mp4 encoded videos and two other bench mark datasets. The results proves a significant improvement in performance in comparison to the sequential version; which ranges from 64.2% to 95.3%, for a cluster with a number of machines ranging from 2 to 20 respectively.

     

A real-time approach for automatic defect detection from PCBs based on SURF features and morphological operations

Multimedia Tools and Applications - This paper presents an automatic inspection approach for Printed Circuit Boards (PCBs) with accurate determination of the fault location and identification of...     

A dual‐band case‐printed planar inverted‐F antenna design with independent resonance control for wearable short range telemetric systems

In this article, a novel 3D meandered planar inverted‐F antenna (PIFA) is proposed for dual band application targeting Wireless Body Area Network (WBAN). The proposed antenna is printed on the casing of a 3D‐base‐station model having a size of 88 × 95 × 10.2 mm³. The proposed PIFA covers two bands including medical implant communication service (MICS) (402‐405 MHz), as well as the industrial, scientific, and medical (ISM) (2.4‐2.48 GHz) bands. Each of the two bands can be controlled independently. The 3D configuration contains two linked meandered resonators to downsize the structure. Due to its conformal shape, omnidirectional radiation pattern, and low‐profile nature, the proposed PIFA is a potential candidate for targeting the WBAN applications. The proposed antenna, covering the MICS and ISM bands, works with an optimally matching (VSWR<2) at the aforementioned bands. The design concept was validated by fabricating the antenna prototype and measuring its characteristics.     

Gauss Gradient and SURF Features for Landmine Detection from GPR Images

Recently, ground-penetrating radar (GPR) has been extended as a well-known area to investigate the subsurface objects. However, its output has a low resolution, and it needs more processing for more interpretation. This paper presents two algorithms for landmine detection from GPR images. The first algorithm depends on a multi-scale technique. A Gaussian kernel with a particular scale is convolved with the image, and after that, two gradients are estimated; horizontal and vertical gradients. Then, histogram and cumulative histogram are estimated for the overall gradient image. The bin values on the cumulative histogram are used for discrimination between images with and without landmines. Moreover, a neural classifier is used to classify images with cumulative histograms as feature vectors. The second algorithm is based on scale-space analysis with the number of speeded-up robust feature (SURF) points as the key parameter for classification. In addition, this paper presents a framework for size reduction of GPR images based on decimation for efficient storage. The further classification steps can be performed on images after interpolation. The sensitivity of classification accuracy to the interpolation process is studied in detail.     

Catalytic transformation of H2S for H2 production

Hydrogen sulfide (H₂S) gas is a by-product from natural gas refining, hydrodesulfurization of various fossil fuels, and syngas cleaning from pyrolysis and gasification. Catalytic pyrolysis of H₂S provides an alternative and effective pathway to recover both H₂ and sulfur. Catalysts from hydrotalcite of ZnAl, ZnNiAl, and ZnFeAl were employed for H₂S pyrolysis and compared with TiO₂ and MoS₂ at atmospheric pressure and temperatures in the range of 923–1123 K. Kinetic analysis was carried out in a packed bed reactor which revealed the effect of H₂S partial pressures to be of the order of 0.8–1 with respect to H₂S. The developed novel catalysts showed improved performance with significantly reduced activation energy compared to TiO₂ by 30 kJ/mol as well as higher H₂S conversion during pyrolysis (17% at 1173 K) than with MoS₂ catalyst, even at high H₂S partial pressure which is necessary for viable hydrogen production. The new approach showed an alternate economical and efficient pathway of catalyst design to obtain high activity and stability for simultaneous H₂ energy and pure sulfur recovery from unwanted H₂S resources.