Search results for: catalytic membrane

Authors: Alaa Y. Ali, Natalie P. Holmes, John Holdsworth, Warwick Belcher, Paul Dastoor, Xiaojing Zhou

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Multi-layered graphene has been produced under low temperature chemical vapour deposition (CVD) growth conditions by utilizing an organic solvent and polymer film source. Poly(methylmethacrylate) (PMMA) was dissolved in chlorobenzene solvent and used as a drop-cast film carbon source on a quartz slide. A source temperature (T_source) of 180 °C provided sufficient carbon to grow graphene, as identified by Raman spectroscopy, on clean copper foil catalytic surfaces.  Systematic variation of hydrogen gas (H₂) flow rate from 25 standard cubic centimeters per minute (sccm) to 100 sccm and CVD temperature (T_growth) from 400 to 800 °C, yielded graphene films of varying quality as characterized by Raman spectroscopy. The optimal graphene growth parameters were found to occur with a hydrogen flow rate of 75 sccm sweeping the 180 °C source carbon past the Cu foil at 600 °C for 1 min. The deposition at 600 °C with a H₂ flow rate of 75 sccm yielded a 2D band peak with ~53.4 cm^-1 FWHM and a relative intensity ratio of the G to 2D bands (I_G/I_2D) of 0.21. This recipe fabricated a few layers of good quality graphene.

Keywords: graphene, chemical vapor deposition, carbon source, low temperature growth

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Authors: M. S. Abd El-Sadek, Mahmoud A. Omar, Gharib M. Taha

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Photodegradation of methylene blue in the presence of tin dioxide (SnO₂) nanoparticles under solar light irradiation are known to be an effective photocatalytic process. In this study, pure and silver (Ag) doped tin dioxide (SnO₂) nanoparticles were prepared at calcination temperature (800ºC) by a modified sol-gel method and studied for their photocatalytic activity with methylene blue as a test contaminant. The characterization of undoped and doped SnO₂ photocatalyst was studied by X-rays diffraction patterns (XRD), transmission electron microscopy (TEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Energy Dispersive X-ray Microanalysis (EDX). The catalytic degradation of methylene blue in aqueous media was studied using UV-Vis spectrophotometer to monitor the degradation process by measuring its absorption spectra. The main absorption peak of methylene blue is observed at λ= 664 nm. The change in the percent of silver in the catalyst affects the photoactivity of SnO₂ on the degradation of methylene blue. The photoactivity of pure SnO₂ was found to be a maximum at dose 0.2 gm of the catalyst with 100 ml of 5 ppm methylene blue in the water. Within 210 min of photodegradation (under sunlight) after leaving the reaction for 90 minutes in the dark to avoid the effect of adsorption, the pure SnO₂ at calcination temperature 800ºC exhibited the best photocatalytic degradation with removal percentage of 93.66% on methylene blue degradation under solar light.

Keywords: SnO₂ nanoparticles, methylene blue degradation, photocatalysis, silver doped-SnO₂

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Authors: Faruk Emir, Simel Ayyıldız, Cem Şahin

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Behçet’s disease or Behçet’s syndrome is a chronic and multi-systemic inflammatory disease of unknown cause. This syndrome often presents with mucous membrane ulceration and ocular problems. As a systemic disease Behcet includes triple-symptom complex of recurrent oral aphthous ulcers, genital ulcers, and uveitis. Nearly all patients present with some form of painful oral mucocutaneous ulcerations in the form of aphthous ulcers. The aim of the treatment plan for Behçet’s Disease patients is to eliminate oral problems and increase the patient comfort.This clinical report represents the prosthodontic rehabilitation of Behcet’s disease patients mandibular total edentulism with the use of implant supported prosthesis that planned on custom abutments and bar retainers via CAD/CAM technology and patient satisfaction has been achieved in function and aesthetics.

Keywords: Behçet’s disease, CAD/CAM, custom-made manufacturing, titanium milled bar retainer

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Authors: Aw Adi Arryansyah

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Using electronic stethoscope for detecting heartbeat sound, and breath sounds, are the effective way to investigate cardiovascular diseases. On the other side, technology is growing towards mobile. Almost everyone has a smartphone. Smartphone has many platforms. Creating mobile applications also became easier. We also can use HTML5 technology to creating mobile apps. Android is the most widely used type. This is the reason for us to make a wireless electronic stethoscope based on Android mobile. Android based Wireless Electronic Stethoscope designed by a simple system, uses sound sensors mounted membrane, then connected with Bluetooth module which will send the heart auscultation voice input data by Bluetooth signal to an android platform. On the software side, android will read the voice input then it will translate to beautiful visualization and release the voice output which can be regulated about how much of it is going to be released. We can change the heart beat sound into BPM data, and heart beat analysis, like normal beat, bradycardia or tachycardia.

Keywords: wireless, HTML 5, auscultation, bradycardia, tachycardia

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Authors: Cristiano Giordani, Marco Diociaiuti, Cecilia Bombelli, Laura Zanetti-Polzi, Marcello Belfiore, Raoul Fioravanti, Gianfranco Macchia

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We investigated induced functional effects by evaluating Ca2+-influx in liposomes and cell viability in HT22-DIFF neurons. Only solutions rich in unstructured Prefibrillar-Oligomers (PFOs) were able, in the presence of Monosialoganglioside-GM1 (GM1), to induce Ca2+-influx and were also neurotoxic, suggesting a correlation between the two phenomena. Thus, in the presence of GM1, we investigated the protein conformation and liposome modification due to the interaction. Circular Dichroism showed that GM1 fostered the formation of β-structures and Energy Filtered-Transmission Electron Microscopy that PFOs formed “amyloid-channels” as reported for Aβ. We speculate that electrostatic forces occurring between the positive PFOs and negative GM1 drive the initial binding, while the hydrophobic profile of the flexible PFO is responsible for the subsequent pore formation. Conversely, the rigid β-structured mature/fibers (MFs) and proto-fibers (PFs) were unable to induce membrane damage and Ca2+- influx.

Keywords: amyloid proteins, neurotoxicity, lipid-rafts, GM1

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Authors: Yeng Min Yi, Rosli Md Illias, Salehhuddin Hamdan

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Industrial biocatalysis is mainly based on the use of cell free or intracellular enzyme systems. However, the expensive cost and relatively lower operational stability of free enzymes limit practical use in industries. Cell surface display system can be used as a cost-efficient alternative to overcome the laborious purification and substrate transport limitation. In this research, TibA autotransporter from E. coli was used to display Aspergillus fumigatus xylanase (xyn). The amplified xyn was fused in between N-terminal signal peptide and C-terminal β-barrel of TibA. The cloned was transformed and expressed in E. coli BL21 (DE3). Outer membrane localization of TibA-xyn fusion protein was confirmed by SDS PAGE and western blot with expected size of 62.5 kDa. Functional display of xyn was examined by activity assay. Cell surface displayed xyn exhibited the highest activity at 37 °c, 0.3 mM IPTG. As a summary, TibA displaying system has the potential for further industrial applications. Moreover, this is the first report of the display of xylanase using TibA on the surface of E. coli.

Keywords: biocatalysis, cell surface display, Escherichia coli, TibA autotransporter

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Authors: Rachna, Uma Shanker

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Aromatic phenols, being priority pollutants, are found in various industrial effluents and seeking the attention of environmentalists worldwide, owing to their life-threatening effects. In the present study, the coupling of zinc oxide with Prussian blue was achieved involving co-precipitation synthesis process using Azadirachta indica plant extract. The fabricated nanocatalyst was employed for the sunlight mediated photodegradation of various phenols (Phenol, 3-Aminophenol, and 2,4-Dinitrophenol). Doping of zinc oxide with Prussian blue caused an increase in the surface area to value 80.109 m²g⁻¹ and also enhanced the semiconducting tendency of the nanocomposite with band gap energy 1.101 eV. The experiment was performed at different parameters of phenols concentration, catalyst amount, pH, time, and exposure of sunlight. The obtained results showed a lower elimination of 2,4-DNP (93%) than 3-AP (97%) and phenol (95%) owing to their molecular weight and basicity differences. In comparison to the starting material (zinc oxide and Prussian blue), nanocomposite was more capable in degrading the phenols and lowered the t1/2 value of phenol (4.405 h), 3-AP (4.04 h) and 2,4-DNP (4.68 h) to a greater extent. Effect of different foreign anions was also studied to check nanocomposite’s liability under natural conditions. The extent of charge recombination being the most limiting factor in the photodegradation of pollutants was determined through the photoluminescence. Sunlight active ZnO@FeHCF nanocomposite was proven to exhibit good catalytic ability up to 10 cycles.

Keywords: nanocomposite, phenols, photodegradation, sunlight, water

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Authors: Ahmet Aslan, Safiye Meric Acikel, Raziye Hilal Senay, Sinan Akgol

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Different chemical substances and too much water are used during leather production. Therefore, the waste water load of the leather industry is harmful to the environment. One of the pollution sources is the production of leather coloring process is a further need to focus on the removal of dye waste waters subject. These water-soluble dyes have a small organic molecular size. Besides the environmental hazards, these dyes cannot be underestimated, they also have harmful effects on human health. In this study, poly(hydroxyethyl methacrylate-glycidyl methacrylate) p(HEMA-GMA) hydrogel membranes were synthesized by UV polymerization method. The hydrogel synthesized is modified with imino diacetic acid (IDA) and then chelated with Cr (III) ions. The chelating capacity of the membranes was determined according to the time, pH and concentration parameters. Dynamic swelling test, elemental analysis, ninhydrin analysis and adsorption, desorption and reusability performances of membranes were also determined.

Keywords: adsorption, dye, leather, p(HEMA-GMA)-IDA

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Authors: Osama M. Darwesh, Sahar H. Hassan, Abd El-Raheem R. El-Shanshoury, Shawky Z. Sabae

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Nanotechnology as multidisciplinary technology is growing rapidly with important applications in several sectors. Also, nanobiotechnology is known for the use of microorganisms for the synthesis of targeted nanoparticles. The present study deals with the green synthesis of silver nanoparticles using aquatic bacteria and the development of a biogenic nanocomposite for environmental applications. Twenty morphologically different colonies were isolated from the collected water samples from eight different locations at the Rosetta branch of the Nile Delta, Egypt. The obtained results illustrated that the most effective bacterial isolate (produced the higher amount of AgNPs after 24 h of incubation time) is isolate R3. Bacillus tequilensis was the strongest extracellular bio-manufactory of AgNPs. Biosynthesized nanoparticles had a spherical shape with a mean diameter of 2.74 to 28.4 nm. The antimicrobial activity of silver nanoparticles against many pathogenic microbes indicated that the produced AgNPs had high activity against all tested multi-antibiotic resistant pathogens. Also, the stabilized prepared AgNPs-SA nanocomposite has greater catalytic activity for the decolourization of some dyes like Methylene blue (MB) and Crystal violet. Such results represent a promising stage for producing eco-friendly, cost-effective, and easy-to-handle devices for the bioremediation of contaminated industrial wastewater.

Keywords: bioremediation, AgNPs, AgNPs-SA nanocomposite, Bacillus tequilensis, nanobiotechnology

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Authors: K. Suresh, R. Arunkumar

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The objective of this study is to investigate the preparation of gramine nano suspension and protective effect of Gramine on the apoptosis of laryngeal cancer cells cell line (HEp-2 and KB). The growth inhibition rate of Hep-2 and KB cells in vitro were measured by MTT assay and apoptosis by, levels of reactive oxygen species, mitochondrial membrane potential, morphological changes and flowcytometry. Based on the results, we determined the effective doses of gramine as 127.23µm/ml for 24 hr and 119.81 µm/ml for 48hr in hep-2 cell line and 147.58 µm ml for 24 hr and 123.74µm µm/ml for 48hr in KB cell line. cytotoxicity effects of gramine were confirmed by treatment of HEp-2 cell and KB cell with IC50 concentration of gramine resulted in sequences of events marked by the enhance the apoptosis accompanied by loss of cell viability, modulation of reactive oxygen species and cell cycle arrest through the induction of G0/G1 phase arrest on HEp-2 cells. Our study suggests that the nanosuspension of gramine possesses the more cytotoxic effect of cancer cells and a novel candidate for cancer chemoprevention.

Keywords: apoptosis, HEp-2 cell line, KB cell line mitochondria, gramine, nanosuspension

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Authors: Shah Sufaid, Hussain Shahid, Tianyan You, Liu Guiwu, Qiao Guanjun

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Nickel oxide (NiO) is an optimal material for precise detection of hydrogen (H₂) gas due to its high catalytic activity and low resistivity. However, the gas response kinetics of H₂ gas molecules with the surface of NiO concurrence limitation imposed by its solid structure, leading to a diminished gas response value and slow electron-hole transport. Herein, NiO@CuO NFs with porous sharp-tip and nanospheres morphology were successfully synthesized by using a metal-organic framework (MOFs) as a precursor. The fabricated porous 2 wt% NiO@CuO NFs present outstanding selectivity towards H₂ gas, including a high sensitivity of a response value (170 to 20 ppm at 150 °C) higher than that of porous Ni-MOF (6), low detection limit (300 ppb) with a notable response (21), short response and recovery times at (300 ppb, 40/63 s and 20 ppm, 100/167 s), exceptional long-term stability and repeatability. Furthermore, an understanding of NiO@CuO sensor functioning in an actual environment has been obtained by using the impact of relative humidity as well. The boosted hydrogen sensing properties may be attributed due to synergistic effects of numerous facts including p-p heterojunction at the interface between NiO and CuO nanoflowers. Particularly, a porous Ni-MOF structure combined with the chemical sensitization effect of NiO with the rough surface of CuO nanosphere, are examined. This research presents an effective method for development of Ni-MOF derived metal oxide semiconductor (MOS) heterostructures with rigorous morphology and composition, suitable for gas sensing application.

Keywords: NiO@CuO NFs, metal organic framework, porous structure, H₂, gas sensing

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Authors: T. Büyüksırıt, H. Kuleaşan

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Natural antimicrobials are used to preserve foods that can be found in plants, animals, and microorganisms. Antimicrobial substances are natural or artificial agents that produced by microorganisms or obtained semi/total chemical synthesis are used at low concentrations to inhibit the growth of other microorganisms. Food borne pathogens and spoilage microorganisms are inactivated by the use of antagonistic microorganisms and their metabolites. Yeasts can produce toxic proteins or glycoproteins (toxins) that cause inhibition of sensitive bacteria and yeast species. Antimicrobial substance producing phenotypes belonging different yeast genus were isolated from different sources. Toxins secreted by many yeast strains inhibiting the growth of other yeast strains. These strains show antimicrobial activity, inhibiting the growth of mold and bacteria. The effect of antimicrobial agents produced by yeasts can be extremely fast, and therefore may be used in various treatment procedures. Rapid inhibition of microorganisms is possibly caused by microbial cell membrane lipopolysaccharide binding and in activation (neutralization) effect. Antimicrobial agents inhibit the target cells via different mechanisms of action.

Keywords: antimicrobial agents, yeast, toxic protein, glycoprotein

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Authors: Zhiwen Yang, Jingyuan Li, Zhenkai Xie, Jian Ling, Jiguang Wang, Mengliang Li

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To reflect the effects of different emission control strategies, such as retrofitting after-treatment system and replacing with natural gas-fueled vehicles, on particle number (PN), particle mass (PM) and nitrogen oxides (NOx) emissions emitted by urban bus, a portable emission measurement system (PEMS) was employed herein to conduct real-world driving emission measurements on a diesel oxidation catalytic converter (DOC) and catalyzed diesel particulate filter (CDPF) retrofitting China IV diesel bus, a China IV diesel bus, and a China V natural gas bus. The results show that both tested diesel buses possess markedly advantages in NOx emission control when compared to the lean-burn natural gas bus equipped without any NOx after-treatment system. As to PN and PM, only the DOC+CDPF retrofitting diesel bus exhibits enormous benefits on emission control relate to the natural gas bus, especially the normal diesel bus. Meanwhile, the differences in PM and PN emissions between retrofitted and normal diesel buses generally increase with the increase in vehicle-specific power (VSP). Furthermore, the differences in PM emissions, especially those in the higher VSP ranges, are more significant than those in PN. In addition, the maximum peak PN particle size (32 nm) of the retrofitted diesel bus was significantly lower than that of the normal diesel bus (100 nm). These phenomena indicate that the CDPF retrofitting can effectively reduce diesel bus exhaust particle emissions, especially those with large particle sizes.

Keywords: CDPF, diesel, natural gas, real-world emissions

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Authors: A. T. Adetunji, F. B. Lewu, R. Mundembe

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Plants require nitrogen (N) to support desired production levels. Nitrogen is available to plants in the form of nitrate or ammonium, which are transported into the cell with the aid of various transport proteins. Ammonium transporters (AMTs) play a role in the uptake of ammonium, the form in which nitrogen is preferentially absorbed by plants. Solanum tuberosum AMT1 (StAMT1) was characterized using molecular biology and bioinformatics methods. Nucleotide database sequences were used to design AMT1-specific primers which were used to amplify the AMT1 internal regions. Nucleotide sequencing, alignment and phylogenetic analysis assigned StAMT1 to the AMT1 family. The deduced amino acid sequences showed that StAMT1 is 92%, 83% and 76% similar to Solanum lycopersicum LeAMT1.1, Lotus japonicus LjAMT1.1 and Solanum lycopersicum LeAMT1.2 respectively. StAMT1 fragments were shown to correspond to the 5th - 10th trans-membrane domains. Residue StAMT1 D15 is predicted to be essential for ammonium transport, while mutations of StAMT1 S76A may further enhance ammonium transport.

Keywords: ammonium transporter, bioinformatics, nitrogen, primers, Solanum tuberosum

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Authors: Ge Cui, Mei Fang Chien, Chihiro Inoue

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In this research, enrichment culture using an inorganic liquid medium collected soil contaminated with 1,2-dichlorobenzene (1,2-DCB) in Sendai, Japan, was added 1,2-DCB as the sole carbon source to create a stable consortium. The purpose of this research is to analysis dominant microorganisms in the stable consortium and enzyme system which play a role in the degradation of DCBs. The consortium is now at 30 generation and is still being cultured. By the result of PCR-DGGE and clone library, two bacteria are dominant. The bacteria named sk1 was isolated. 40mg/l of 1,2-DCB and 40mg/l of 1,4-DCB were completely degraded after 32 hours and 50 hours, respectively, but no degradation occurred in the case of 1,3-DCB. By PCR, tecA1 (α-subunit of DCB dioxygenase) gene which plays a role degrading DCB to DCB dihydrodiol, and tecB (dehydrogenase) gene which plays a role degrading DCB dihydrodiol to dichlorocatechol were amplified from strain sk1. Bacteria named sk100 was also isolated. 40mg/l of 1,2-DCB was completely degraded after 32 hours, but no degradation occurred in case of 1,3-DCB and 1,4-DCB. By the result of the catalytic core region of dioxygenase amplified by PCR, gene played a role degrading DCB was analyzed. The results of this study concluded that the isolated strains which have not been reported are able to degrade 1,2-DCB stably, and the characterization of degradation and the genomic analysis which is now in progress is helpful to have an overall view of this microbial degradation.

Keywords: DCB, 1, 2-DCB degrading strains, DCB dioxygenase, enrichment culture

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Authors: Rawaz A. Ahmed, Katherine Huddersman

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High-lipid Fats, Oils and Grease (FOGs) from wastewater are underutilized despite their potential for conversion into valuable fuels; this work describes a surface-functionalized fibrous Polyacrylonitrile (PAN) mesh as a novel heterogeneous acid catalyst for the conversion of free fatty acids (FFAs), via a catalytic esterification process into biodiesel. The esterification of stearic acid (SA) with methanol was studied over an acidified PAN solid acid catalyst. Disappearance of the carboxylic acid (C=O) peak of the stearic acid at 1696 cm-1 in the FT-IR spectrum with the associated appearance of the ester (C=O) peak at 1739 cm-1 confirmed the production of the methyl stearate. This was further supported by 1H NMR spectra with the appearance of the ester (-CH₂OCOR) at 3.60-3.70 ppm. Quantitate analysis by GC-FID showed the catalyst has excellent activity with >95 % yield of methyl stearate (MS) at 90 ◦C after 3 h and a molar ratio of methanol to SA of 35:1. To date, to our best knowledge, there is no research in the literature on the esterification reaction for biodiesel production using a modified PAN mesh as a catalyst. It is noteworthy that this acidified PAN mesh catalyst showed comparable activity to conventional Brönsted acids, namely H₂SO₄ and p-TSA, as well as exhibiting higher activity than various other heterogeneous catalysts such as zeolites, ion-exchange resins and acid clay.

Keywords: fats oil and greases (FOGs), free fatty acid, esterification reaction, methyl ester, PAN

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Authors: Shuafeng Yuan, Bojian Zheng

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The RNA-dependent RNA polymerase of influenza a virus comprises conserved and independently folded subdomains with defined functionalities. The N-terminal domain of the PA subunit (PAN) harbors the endonuclease function so that it can serve as a desired target for drug discovery. To identify a class of anti-influenza inhibitors that impedes PAN endonuclease activity, a screening approach that integrated the fluorescence resonance energy transfer based endonuclease inhibitor assay with the DNA gel-based endonuclease inhibitor assay was conducted, followed by the evaluation of antiviral efficacies and potential cytotoxicity of the primary hits in vitro and in vivo. A small-molecule compound ANA-0 was identified as a potent inhibitor against the replication of multiple subtypes of influenza A virus, including H1N1, H3N2, H5N1, H7N7, H7N9 and H9N2, in cell cultures. Combinational treatment of zanamivir and ANA-0 exerted synergistic anti-influenza effect in vitro. Intranasal administration of ANA-0 protected mice from lethal challenge and reduced lung viral loads in H1N1 virus infected BALB/c mice. Docking analyses predicted ANA-0 bound the endonuclease cavity of PAN by interacting with the metal-binding and catalytic residues. In summary, ANA-0 shows potential to be developed to novel anti-influenza agents.

Keywords: anti-influenza, novel compound, inhibition of endonuclease, PA

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Authors: Ali Naeemy, Mir Ghasem Hoseini

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In this study, for the first time, an analytical method developed and validated by combining electrochemical impedance spectroscopy and electromembrane extraction (EIS-EME) by Vulcan/poly pyrrole nanocomposite modified screen-printed electrode (PPY–VU/SPE) for accurately quantifying zolpidem. EME parameters optimized, including solvent composition, voltage, pH adjustments and extraction time. Zolpidem was transferred from a donor solution (pH 5) to an acceptor solution (pH 13) using a hollow fiber in 1-octanol as a membrane, driven by a 60 V voltage for 25 minutes, ensuring precise and selective extraction. In comparison with SPE, VU/SPE and PPY/SPE, the PPY–VU/SPE was much more efficient for ZP oxidation. Calibration curves with good linearity were obtained in the concentration range of 2-75 µmol L-1 using the EIS-EME with the detection limit of 0.5 µmol L-1 . Finally, the EIS-EME by using the PPY– VU/SPE was successfully used to determine ZP in tablet dosage form, urine and plasma samples. Keywords: Electrochemical impedance spectroscopy, Electromembrane extraction, Zolpidem, Vulcan, poly pyrrole, Screen printed electrode

Keywords: electrochemical impedance spectroscopy, electromembrane extraction, screen printed electrode, zolpidem

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Authors: Piyaporn Buaklang, Narisa Kengtrong Bordeerat

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The use of nanoparticles is increasing worldwide and there are many nanotech-based daily products available in the market. The toxicity of nanoparticles results from their extremely small size which can be transported easily into the blood stream and other organs. We aimed to study the genotoxicity of two nanoparticles, Titanium dioxide (TiO2-NPs) and Zinc oxide (ZnO-NPs), in TK6 cells by micronucleus assay. The cells were tested at 8, 24, and 48 hours after exposed to 0.10, 0.25, 0.50 and 1.00 µg/mL of TiO2-NPs particles size < 25 nm and < 100 nm and to ZnO-NPs at 1, 10, 50, and 100 µg/mL, particles size < 50 nm and < 100 nm. At 24 hours of incubation transmission electron microscope (TEM) revealed that the nanoparticles TiO2-NPs at 1.00 µg/mL and ZnO-NPs at 10 µg/mL were able to be taken into the cells and induced the production of increasing amount of micronucleus in dose-dependent manner. The effect of the two nanoparticles on chromosome aberration indicated that TiO2-NPs and ZnO-NPs are genotoxic. In addition, the toxicity of TiO2-NPs was found to be 10 times more toxic than ZnO-NPs after 24 hours exposure. Analysis showed that the TiO2-NPs induced formation of micronucleus was both time and dose dependent, whereas the genotoxicity of ZnO-NPs was only dose dependent. In conclusion, TiO2-NPs and ZnO-NPs were able to transport through the cells membrane and directly genotoxic to TK6 cells in dose-dependent manner.

Keywords: nanoparticles, genotoxicity, human lymphoblast cells (TK6), micronucleus

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Authors: Min-Hwa Lim, Mi-Jeong Park, Ho-Young Jung

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Imidazolium-brominated polyphenylene oxide (Im-bPPO) is based on the functionalization of bromomethylated poly(2,6-dimethyl-1,4-phenylene oxide) (BPPO) using 1-Methylimdazole. For the purpose of long cycle life of vanadium redox battery (VRB), the chemical stability of Im-bPPO, sPPO (sulfonated 2,6-dimethyl-1,4-phenylene oxide) and Fumatech membranes were evaluated firstly in the 0.1M vanadium (V) solution dissolved in 3M sulfuric acid (H2SO4) for 72h, and UV analyses of the degradation products proved that ether bond in PPO backbone was vulnerable to be attacked by vanadium (V) ion. It was found that the membranes had slightly weight loss after soaking in 2 ml distilled water included in STS pressure vessel for 1 day at 200◦C. ATR-FT-IR data indicated before and after the degradation of the membranes. Further evaluation on the degradation mechanism of the menbranes were carried out in Fenton’s reagent solution for 72 h at 50 ◦C and analyses of the membranes before and after degradation confirmed the weight loss of the membranes. The Fumatech membranes exhibited better performance than AEM and CEM, but Nafion 212 still suffers chemical degradation.

Keywords: vanadium redox flow battery, ion exchange membrane, permeability, degradation, chemical stability

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Authors: Maymona Al-Husari, Craig Murdoch, Steven Webb

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Some tumors are known to exhibit an extracellular pH that is more acidic than the intracellular, creating a 'reversed pH gradient' across the cell membrane and this has been shown to affect their invasive and metastatic potential. Tumour hypoxia also plays an important role in tumour development and has been directly linked to both tumour morphology and aggressiveness. In this paper, we present a hybrid mathematical model of intracellular pH regulation that examines the effect of oxygen and pH on tumour growth and morphology. In particular, we investigate the impact of pH regulatory mechanisms on the cellular pH gradient and tumour morphology. Analysis of the model shows that: low activity of the Na+/H+ exchanger or a high rate of anaerobic glycolysis can give rise to a 'fingering' tumour morphology; and a high activity of the lactate/H+ symporter can result in a reversed transmembrane pH gradient across a large portion of the tumour mass. Also, the reversed pH gradient is spatially heterogenous within the tumour, with a normal pH gradient observed within an intermediate growth layer, that is the layer between the proliferative inner and outermost layer of the tumour.

Keywords: acidic pH, cellular automaton, ebola, tumour growth

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Authors: Shoaei Shahram, Rafiei Felora

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To study the effects of using superabsorbent polymers on physiological of maize in deficit Irrigation condition .an experiment carried out in split plot factorial based on completely Randomized Block design (RCBD) with three replication in 2012years. Deficit Irrigation was applied by three different Irrigation amount. Super absorbent polymers in 3 levels were and two veriety of maize allocated in sub plots. there was significant difference between Irrigation levels in all experimental Traits by increasing in deficit irrigation. Results of this research showed water stress significantly decreased relative water content (RWC) LAI,Ash percentage in both hybrids, and increased Cell membrane percentage and SPAD,ADF percent.whereas the application of super absorbent polymer compensated the negative effect of drought stress, especially in high rates of polymer application .These mentioned rates of polymer had the best effect to all of the studied traits. These findings can be suggested that the irrigation intervals of corn could be increased by application of super absorbent polymer.

Keywords: super absorbent, p hysiological, water stress, zea maize

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Authors: Dwarakanadha Reddy Peram, D. Swarnalatha, C. Gopinath

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The main aim of this research work was to design and development characterization of Pioglitazone transdermal drug delivery system by using various polymers such as Olibanum with different concentration by solvent evaporation technique. The prepared formulations were evaluated for different physicochemical characteristics like thickness, folding endurance, drug content, percentage moisture absorption, percentage moisture loss, percentage elongation break test and weight uniformity. The diffusion studies were performed by using modified Franz diffusion cells. The result of dissolution studies shows that formulation, F3 (Olibanum with 50 mg) showed maximum release of 99.95 % in 12hrs, whereas F1 (Olibanum and EC backing membrane) showed minimum release of 93.65% in 12 hr. Based on the drug release and physicochemical values obtained the formulation F3 is considered as an optimized formulation which shows higher percentage of drug release of 99.95 % in 12 hr. The developed transdermal patches increase the therapeutic efficacy and reduced toxic effect of pioglitazone.

Keywords: pioglitazone, olibanum, transdermal drug delivery system, drug release percantage

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Authors: Maryam Zahedi Fard, Nazia Abdul Majid, Hapipah Mohd Ali, Mahmood Ameen Abdulla

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New quinazoline schiff base 3-(5-bromo-2-hydroxy-3-methoxybenzylideneamino)-2-(5-bromo-2-hydroxy-3-methoxyphenyl)-2,3-dihydroquinazolin-4(1H)-one was investigated for anticancer activity against MCF-7 human breast cancer cell line with involved mechanism of apoptosis. The compound demonstrated a remarkable antiproliferative effect, with an IC50 value of 3.41 ± 0.34, after 72 hours of treatment. Morphological apoptotic features in treated MCF-7 cells were observed by AO/PI staining. Furthermore, treated MCF-7 cells subjected to apoptosis death, as exhibited by perturbation of mitochondrial membrane potential and cytochrome c release as well as increase in ROS generation. We also found activation of caspases 3/7 and -9. Moreover, acute toxicity test demonstrated the nontoxic nature of the compound in mice. Our results showed the selected compound significantly induce apoptosis in MCF-7 cells via intrinsic pathway, which might be considered as a potent candidate for further in vivo and clinical breast cancer studies.

Keywords: antiproliferative effect, MCF-7 human breast cancer cell line, apoptosis, caspases

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Authors: Sanaa Bardaweel

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Inorganic polyphosphate (poly P) is present in all living forms tested to date, from each of the three kingdoms of life. Studied mainly in prokaryotes, poly P and its associated enzymes are vital in diverse basic metabolism, in at least some structural functions and, notably, in stress responses. These plentiful and unrelated roles for poly P are probably the consequence of its presence in life-forms early in evolution. The genomes of many bacterial species, including pathogens, encode a homologue of a major poly P synthetic enzyme, poly P kinase 1 (PPK1). Genetic deletion of ppk1 results in reduced poly P levels and loss of pathogens virulence towards protozoa and animals. Thus far, no PPK1 homologue has been identified in higher-order eukaryotes and, therefore, PPK1 represents a novel target for chemotherapy. The idea of the current study is to purify the PPK1 from Escherichia coli to homogeneity in order to study the effect of active site point mutations on PPK1 catalysis via the application of site-directed mutagenesis strategy. The knowledge obtained about the active site of PPK1 will be utilized to characterize the catalytic and kinetic mechanism of PPK1 with model substrates. Comprehensive understanding of the enzyme kinetic mechanism and catalysis will be used to design and screen a library of synthetic compounds for potential discovery of selective PPK1-inhibitors.

Keywords: antimicobial, Escherichia coli, inorganic polyphosphate, PPK1-inhibitors

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Authors: N. Laosiripojana, P. Tepamatr

Abstract:

The influence of bismuth on the water gas shift activities of Pt on ceria was studied. The flow reactor was used to study the activity of the catalysts in temperature range 100-400°C. The feed gas composition contains 5%CO, 10% H₂O and balance N₂. The total flow rate was 100 mL/min. The outlet gas was analyzed by on-line gas chromatography with thermal conductivity detector. The catalytic activities of bimetallic 1%Pt1%Bi/CeO₂ catalyst were greatly enhanced when compared with the activities of monometallic 2%Pt/CeO₂ catalyst. The catalysts were characterized by X-ray diffraction (XRD), Temperature-Programmed Reduction (TPR) and surface area analysis. X-ray diffraction pattern of Pt/CeO₂ and PtBi/CeO₂ indicated slightly shift of diffraction angle when compared with pure ceria. This result was due to strong metal-support interaction between platinum and ceria solid solution, causing conversion of Ce⁴⁺ to larger Ce³⁺. The distortions inside ceria lattice structure generated strain into the oxide lattice and facilitated the formation of oxygen vacancies which help to increase water gas shift performance. The H₂-Temperature Programmed Reduction indicated that the reduction peak of surface oxygen of 1%Pt1%Bi/CeO₂ shifts to lower temperature than that of 2%Pt/CeO₂ causing the enhancement of the water gas shift activity of this catalyst. Pt played an important role in catalyzing the surface reduction of ceria and addition of Bi alter the reduction temperature of surface ceria resulting in the improvement of the water gas shift activity of Pt catalyst.

Keywords: bismuth, platinum, water gas shift, ceria

Procedia PDF Downloads 331

Authors: Hirowati Ali, Aisyah Ellyanti, Dewi Rusnita, Septelia Inawati Wanandi

Abstract:

Stem cell has been known for its potency to be differentiated in many cells. Recently stem cell has been used for many treatment of degenerative medicine. It is still controversy whether stem cell can be used for therapy or these cells can activate cancer stem cell. SCUBE2 is a novel secreted and membrane-anchored protein which has been reported to its role in better prognosis and inhibition of cancer cell proliferation. Our study aims to observe whether stem cell can up-regulate SCUBE2 gene in MCF7 breast cancer cell line. We used in vitro study using MCF-7 cell treated with stem cell derived from placenta Wharton's jelly which has been known for its stemness and widely used. Our results showed that MCF-7 cell line grows up rapidly in 6-well culture dish. Stem cell was cultured in 6-well dish. After 50%-60% MCF-7 confluence, we co-cultured these cells with stem cells for 24 hours and 48 hours. We hypothesize SCUBE2 gene which is previously known for its higher expression in better prognosis of breast cancer, is up-regulated after stem cells addition in MCF7 culture dishes.

Keywords: breast cancer cells, inhibition of cancer cells, mesenchymal stem cells, SCUBE2

Procedia PDF Downloads 319

Authors: M. Omer Faruk, A. M. A. M. Zonaed Siddiki, M. Fazal Karim, Md. Masuduzzaman, S. Chowdhury, Md. Shafiqul Islam, M. Alamgir Hossain

Abstract:

The dog tapeworms Echinococcus granulosus develop hydatid cysts in various organs in human and domestic animals worldwide including Bangladesh. The aim of this study was to identify and characterize the genotype of E. granulosus isolated from cattle using 12S rRNA and Cytochrome oxidase 1 (COX 1) genes. A total of 43 hydatid cyst samples were collected from 390 examined cattle samples derived from slaughterhouses. Among them, three cysts were fertile. Genomic DNA was extracted from germinal membrane and/or protoscoleces followed by PCR amplification of mitochondrial 12S rRNA and Cytochrome oxidase 1 gene fragments. The sequence data revealed existence of G1 (64.28%) and possible G3 (21.43%) genotypes for the first time in Bangladesh. The study indicates that common sheep strain G1 is the dominant subtype of E. granulosus in Chittagong region of Bangladesh. This will increase our understanding of the epidemiology of hydatidosis in the southern part of the country and will be useful to plan suitable control measures in the long run.

Keywords: Echinococcus granulosus, Cox1, 12S rRNA, molecular characterization, Bangladesh

Procedia PDF Downloads 318

Authors: Deniz Sahin

Abstract:

Growing concern for the presence and contamination of heavy metals in our water supplies has steadily increased over the last few years. A number of specialized technologies including precipitation, coagulation/flocculation, ion exchange, cementation, electrochemical operations, have been developed for the removal of heavy metals from wastewater. However, these technologies have many limitations in the application, such as high cost, low separation efficiency, Recently, numerous approaches have been investigated to overcome these difficulties and membrane filtration, advanced oxidation technologies (AOPs), and UV irradiation etc. are sufficiently developed to be considered as alternative treatments. Many factors come into play when selecting wastewater treatment technology, such as type of wastewater, operating conditions, economics etc. This study describes these various treatment technologies employed for heavy metal removal. Advantages and disadvantages of these technologies are also compared to highlight their current limitations and future research needs. For example, we investigated the applicability of the ultrafiltration technology for treating of heavy metal ions (e.g., Cu(II), Pb(II), Cd(II), Zn(II)) from synthetic wastewater solutions. Results shown that complete removal of metal ions, could be achieved.

Keywords: heavy metal, treatment methodologies, water, water treatment

Procedia PDF Downloads 144

Authors: Zemour Kamel, Chouhim Kadda Mohamed Amine

Abstract:

Salinity is one of the most environmental factors limiting crop productivity. It has a negative effect on both germination and plant growth processes (photosynthesis, respiration, and transpiration), nutrient balance, membrane properties and cellular homeostasis, enzymatic and metabolic activities. Among the strategic crops in the world and more mainly in Algeria, durum wheat is very affected by this abiotic stress. For that, this study focuses on an evaluation of salt stress effect on the germination process of durum wheat as well as its response after application of lavender hydrosol and aqueous pistachio extract. The results have shown that all the physicochemical parameters of germination have been affected by this stress. However, lavender hydrosol and aqueous pistachio extract, considered as organic compounds, significantly improved the germination of wheat seeds. Finally, this study has highlighted the importance of using organic products as an ideal alternative to reduce the effect of abiotic stress on durum wheat productivity.

Keywords: salinity, wheat durum, extract, lavender hydrosol, aqueous pistachio

Procedia PDF Downloads 63