354 research outputs found

    Performance Analysis of Multi-Antenna Relay Networks over Nakagami-m Fading Channel

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    In this chapter, the authors present the performance of multi-antenna selective combining decode-and- forward (SC-DF) relay networks over independent and identically distributed (i.i.d) Nakagami-m fading channels. The outage probability, moment generation function, symbol error probability and average channel capacity are derived in closed-form using the Signal-to-Noise-Ratio (SNR) statistical character- istics. After that, the authors formulate the outage probability problem, optimize it with an approximated problem, and then solve it analytically. Finally, for comparison with analytical formulas, the authors perform some Monte-Carlo simulations

    The effects of Zataria multiflora on inhibition of polyphenoloxidase and melanosis formation in shrimp (Litopenaeus vannamei)

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    Shrimp melanosis (black spot) is an important surface discoloration caused by polyphenol oxidase (tyrosinase) enzyme, which oxidizes phenols and leads to insoluble black pigments, the melanins. Sulphiting agents are widely used as melanosis inhibitors; but, the hazards related to sulphated foods, such as allergic reactions and severe disorders in asthmatic patients have created a necessity to find the effective natural alternatives. The current study was accomplished to assay the in vitro antityrosinase effect of Z. multiflora EO as well as its capability to retard the melanosis formation in shrimp during iced storage. According to GC/MS results, carvacrol, thymol and p-cymene were the major components of Z.multiflora EO, representing 50.8, 14.4 and 10.6, respectively. DPPH radical scavenging activity of EO was 0.8±0.02 mg/ml and 63.2% of tyrosinase activity decreased when EO with a concentration of 0.25% was applied. Furthermore, it has been observed that immersing the shrimps in 1% EO aqueous suspension retarded the melanosis formation in shrimp during 10 days of iced storage. It can be concluded that Z. multiflora EO could be used as an effective natural processing aid to increase the shrimp shelf-life during iced storage

    Electrochemical determination of ciprofloxacin using glassy carbon electrode modified with CoFe2o4-MWCNT

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    CoFe2O4 nanostructures composed of spherical-like were obtained by sol-gel method with glucose as template and combine with MWCNT and composed CoFe2O4-MWCNT heterostructure. The crystal Structure, phase composition, morphology and magnetic properties of CoFe2O4/MWCNT heterostructure were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and vibrating sample magnetometers (VSM), A pure phase of well crystallized CoFe2O4 nanostructures, with average size of 60 nm, could be readily synthesized at present glucose. The modified glassy carbon (GC) electrode with CoFe2O4-MWCNT heterostructure was used to determine the ciprofloxacin concentration. A cyclic voltammetric technique was used for comparison between the unmodified and modified electrodes. The fabricated modified electrode shows linear response for detection of ciprofloxacin at two linear range of 0.1-1 µM and 1-30 µM with a detection limit of 0.036 µM. © 2019 by CEE (Center of Excellence in Electrochemistry)

    Evaluation the Effect of Wheat Germ Fermentation Using Yeast and Lactic Acid Bacteria on the Bioactive Compounds

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    Introduction Wheat germ is a valuable nutritional supplement and a by-product of the flour milling industry used for animal feed and oil extraction. Quinone compounds found in wheat germ have anti-cancer properties that are abundantly found in wheat germ. The aim of this study was to investigate the effect of fermentation conditions on the bioactive compounds in wheat germ with anti-cancer properties. For this purpose, the Saccharomyces cerevisiae 5022 and Lactobacillus plantarum strain 1058 were used for fermentation of wheat germ under different pH levels (4.5, 6, and 7.5) over different time (24, 48, and 72h). Response Surface Methodology was used to find the optimal fermentation conditions and to investigate the effects of above-mentioned conditions on DPPH radical scavenging activity, total phenolics and dimethoxy benzoquinone (DMBQ) content. Moreover, the amounts of bio-peptides and gamma aminobutric acid (GABA) were also determined under optimum conditions.   Materials and Methods To accomplish the fermentation process, 10 g of wheat germ was suspended in 200 mL of sodium phosphate buffer solution. Bacterial and yeast cells were then separated from the culture medium by a centrifugation at 6,000×g for 5 min at room temperature. The harvested cells were then washed with sterile phosphate buffer multiple times, resuspended in water to achieve a cell population of 108 CFU/mL, and finally homogenized using a vortex unit. The yeast and bacterial cells were incubated at 28° C and 37° C, respectively, for 24, 48, and 72 h at pH levels of 4.5, 6.0, and 7.5. Upon the completion of each fermentation process, the obtained samples were lyophilized. Total phenolic content (TPC) was measured using the method adapted  by Liu et al. (2017). Briefly, the Folin-Ciocalteu phenol reagent was diluted ten times using distilled water. Subsequently, 0.1 mL of the extract was mixed with 0.75 mL of the diluted reagent. After 10 min, 0.75 mL sodium carbonate solution (2% w/v) was added to the mixture and vortexed. The absorbance was measured at 765 nm by a spectrophotometer. The antioxidant activity of fermented wheat germs was assessed using the free radical scavenging activity of the samples evaluated through a DPPH radical assay. Briefly, 2 mL of wheat germ extract was diluted with 100 mL 90% methanol aqueous solution. The methanol extract was then mixed with 4 mL of DPPH stock solution. The tube was subsequently kept in the dark for 45 min. The absorbance of each sample was then read using a spectrophotometer at 517 nm (Adedoyin et al., 2013). Dimethoxy benzoquinone (DMBQ) content was measured by an HPLC system. Briefly, 10 g of lyophilized wheat germ sample was dissolved in 250 mL of distilled water and extracted three times by shaking with 200 mL of chloroform. The chloroform layers were collected, washed three times with distilled water, and exposed to sodium sulfate solution to induce drying of the sample. The filtrate was then evaporated using a vacuum evaporator at 30° C to achieve a stable dry material. The dried sample was thereafter dissolved in the mobile phase and injected into the HPLC column to determine the DMBQ content. The HPLC system was equipped with a C-18 column and a UV detector operating at 245 nm. The mobile phase consisted of 20% acetonitrile-80% water (v/v) mixture at a flow rate of 0.5 mL/min and a temperature of 25° C.   Results and Conclusion The highest biological activity was found when fermentation proceeded by L. plantarum under pH 6 for 48 h. Under these optimal conditions, total phenol content (3.33 mg of GAE/g), free DPPH radical scavenging (86.49%), dimethoxy benzoquinone content (DMBQ) (0.56 mg/g), peptide content (607 μg/mL) and gamma aminobutyric acid (GABA) (19983.88 mg/kg) were significantly higher than those of raw non-fermented samples. During the fermentation process, increasing the pH levels led to enhancement of antioxidant activity, total phenolic and DMBQ contents up to 48 h followed by a decline. Also, the fermentation time had a positive effect in the amount of the antioxidant activity, while it allowed an increased followed by a decrease in the contents of total phenolic and DMBQ. These findings underscore the importance of fermentation conditions of wheat germ by L. plantarum and Saccharomyces cerevisiae and can potentially serve as a promising way for the development of valuable products with anti-cancer and antioxidant functions

    Synthesis and characterization of Sm2(MoO4)3, Sm2(MoO4)3/GO and Sm2(MoO4)3/C3N4 nanostructures for improved photocatalytic performance and their anti-cancer the MCF-7 cells

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    Samarium molybdate nanoparticles (Sm2(MoO4)3) were prepared through a hydrothermal procedure and were used to form various composites with graphene oxide (GO) and carbon nitride (C3N4). The changes in the dimensions and morphology of the products were prepared using template agents like cetyltrimethyl ammonium bromide (CTAB), Sodium dodecyl sulfate (SDS) (�90), Triton X-100 (90), Polyvinyl alcohol (95), Ethylene glycol (�99), and polyvinylpyrrolidone (PVP). DRS analysis indicated band gap for the Sm2(MoO4), Sm2(MoO4)3/GO, and Sm2(MoO4)3/C3N4 as 3.75, 3.15, and 3.4 respectively. The characteristics of the prepared nanostructures were studied through X-ray diffraction (XRD), energy dispersive X-ray (EDX), and scanning electron microscopy (SEM). Finally, the activity of the prepared Sm2(MoO4)3 as photo-catalysts for the degradation of different organic dyes such as methyl orange (MO), methylene blue (MB), and rhodamine B (Rh B) was evaluated. The photocatalytic property of Sm2(MoO4)3/C3N4 and Sm2(MoO4)3/GO for the degradation of MO, was obtained. Based on the empirical data Sm2(MoO4)3/C3N4 had the strongest photodegradation effect as compared to the other compounds tested after around 40 min. BET analysis revealed that the specific surface area of the Sm2(MoO4)3 nanocomposite prepared using C3N4 is 15 times that of in the absence of C3N4. Also, the cytotoxicity of synthesized samples was evaluated using MTT assay against human cell lines MCF-7 (cancer), and its IC50 was about 125 mg/L. © 202

    Network-coding-based Cooperative V2V Communication in Vehicular Cloud Networks

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    Chinacom 2018 - 13th EAI International Conference on Communications and Networking in China, 23-25 October 2018, Chengdu, ChinaThis is the author accepted manuscript. the final version is available from Springer Verlag via the DOI in this recordWe investigate the potential of applying cooperative relaying and network coding techniques to support vehicle-to-vehicle (V2V) communication in vehicular cloud networks (VCN). A reuse-mode MIMO content distribution system with multiple sources, multiple relays, and multiple destinations under Nakagami-m fading is considered. We apply a class of finite field network codes in the relays to achieve high spatial diversity in an efficient manner and derive the system communication error probability that the destinations fail to recover the desired source messages. The results show that our method can improve the performance over conventional data transmission solutions

    Preparation of Fe3O4/SiO2/TiO2/CeVO4 Nanocomposites: Investigation of Photocatalytic Effects on Organic Pollutants, Bacterial Environments, and New Potential Therapeutic Candidate Against Cancer Cells

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    The new nanocomposite with various molar ratios along with magnetic properties was fabricated via precipitation (assisted by ultrasonic) procedure. The photocatalytic effects of methylene blue (�90 degradation for optimized sample in 100 min) for finding the optimized sample performed under visible light irradiation. Moreover, the photo-antibacterial impacts of bacteria culture environments were found with an optimized sample that had effective destruction of bacteria in comparison to control group. The cytotoxicity properties of panc1 cells and magnetic behaviors of the obtained nanomaterials were evaluated and its IC50 was about 500 mg/L. As an initial step, the structural, morphological and magnetic characteristics of the fabricated nanocomposites were evaluated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and MAP, UV-visible diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometry (VSM) approaches. Based on SEM results, the size of nanoparticles in fabricated nanocomposite was nearly 50�70 nm for Fe3O4/SiO2/TiO2 and 80�100 nm for Fe3O4/SiO2/TiO2/CeVO4. XRD results showed that desired nanocomposites were truly synthesized without any impurities. © Copyright © 2020 Marsooli, Rahimi-Nasrabadi, Fasihi-Ramandi, Adib, Eghbali-Arani, Ahmadi, Sohouli, Sobhani nasab, Mirhosseini, Gangali, Ehrlich and Joseph

    Electrochemical Oxidation and Determination of Antiviral Drug Acyclovir by Modified Carbon Paste Electrode With Magnetic CdO Nanoparticles

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    With the development of nanomaterials in electrochemical sensors, the use of nanostructures to modify the electrode surface has been shown to improve the kinetics of the electron transfer process. In this study, a sensor was developed for the electrochemical determination of Acyclovir (ACV) based on the modified carbon paste electrode (CPE) by CdO/Fe3O4. The magnetic CdO nanoparticles characterization was studied by energy-dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). To study of the modified CPE surface morphology, scanning electron microscopy (SEM) was used. At the optimal conditions, a noteworthy enhancement in the electrochemical behavior of ACV was observed at the surface of the modified CPE compared to the unmodified CPE. A detection limit of 300 nM and a linear range of 1�100 μM were obtained for the quantitative monitoring of ACV at the modified CPE surface using differential pulse voltammetry (DPV) in phosphate buffer. The RSD (relative standard deviation) of the electrode response was <4.3 indicating the development of a high precision method. Also, satisfactory results were obtained in the determination of ACV with the modified electrode in tablet, blood serum, and urine samples with a satisfactory relative recovery (RR) in the range of 94.0�104.4. © Copyright © 2020 Naghian, Marzi Khosrowshahi, Sohouli, Pazoki-Toroudi, Sobhani-Nasab, Rahimi-Nasrabadi and Ahmadi

    A survey on the effects of the Cochlodinium sp. bloom on the survival of the Litopenaeus vannamei shrimp

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    Red tide event a product of micro algae abundance has elevated in last few years. Loss of aquatic life due to HAB, and its effect on human health, has caused tremendous damage in the world. In this research the effect of (1, 2, 3, 9, and 30) ×10^3 Cells ml^-1 densities of Cochlodinium polykrikoides on survival and histopathological effect on hepatopancreas and gills of Litopenaeus vannamei postlarvae (PLs) and juvenile stages has been investigated. Results showed 100% survival with (1, 2, and 3) ×10^3 Cells ml-1 densities but accumulative mortality in 9×10^3 Cells ml^-1 density were 1.33% and 2.22%, in PLs and juvenile stages respectively, and there is no significant difference between control and treatment groups. accumulative mortality in 3×10^4 Cells ml^-1 density was 4.44% and 17.8% in PLs and juveniles respectively which have significant different with control groups. According to histopathological investigation in this density the infiltration of blood cells in connective tissue of hepatopancreatic tubules and gills lamellae of PLs and juvenile stages were low but high in 3×10^4 Cells ml^-1. The intensity of infiltration in juvenile stages was higher than PLs, which indicate incensement of hepatopancreatic and gills blood cells in higher densities of this phytoplankton. The end result of the study indicates that in high densities of C. polykrikoides survival rate in PLs and juveniles decreased and according to histopathological study the most important possible factor in shrimp mortality when exposure to C. polykrikoides was settlement of phytoplankton on gills lamellae and preventing oxygen exchange of shrimp

    Preparation of Fe3O4/SiO2/TiO2/CeVO4 Nanocomposites: Investigation of Photocatalytic Effects on Organic Pollutants, Bacterial Environments, and New Potential Therapeutic Candidate Against Cancer Cells

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    The new nanocomposite with various molar ratios along with magnetic properties was fabricated via precipitation (assisted by ultrasonic) procedure. The photocatalytic effects of methylene blue (�90 degradation for optimized sample in 100 min) for finding the optimized sample performed under visible light irradiation. Moreover, the photo-antibacterial impacts of bacteria culture environments were found with an optimized sample that had effective destruction of bacteria in comparison to control group. The cytotoxicity properties of panc1 cells and magnetic behaviors of the obtained nanomaterials were evaluated and its IC50 was about 500 mg/L. As an initial step, the structural, morphological and magnetic characteristics of the fabricated nanocomposites were evaluated by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray (EDX) and MAP, UV-visible diffuse reflectance spectroscopy (DRS), and vibrating sample magnetometry (VSM) approaches. Based on SEM results, the size of nanoparticles in fabricated nanocomposite was nearly 50�70 nm for Fe3O4/SiO2/TiO2 and 80�100 nm for Fe3O4/SiO2/TiO2/CeVO4. XRD results showed that desired nanocomposites were truly synthesized without any impurities. © Copyright © 2020 Marsooli, Rahimi-Nasrabadi, Fasihi-Ramandi, Adib, Eghbali-Arani, Ahmadi, Sohouli, Sobhani nasab, Mirhosseini, Gangali, Ehrlich and Joseph
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