Search results for: non aqueous solvent

Authors: Mujeeb Mohd, Aqil Mohd, A. K. Najmi, Akhtar MMohd, Vasim Mohd

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Dioscorea deltoidea belongs to the Dioscoreaceae family, is usually found in the north-western Himalayas and some other parts of the world up to an altitude of 1000–3000 m. D. deltoidea commonly known as yam and is an extensively used medicinal plant in the indigenous system of medicine. It has been reported to contain dioscine a steroidal glycoside in higher concentration. In the present investigation, silver nanoparticles (AgNPs) have been synthesized by a simple, efficient, environmentally benevolent and economic microwave-assisted method. Callus culture of D. deltoidea was developed and maintained on Murashige and skooge basal medium supplemented with different combination and concentration of plant growth regulators. Aqueous extract of callus culture was used as the reducing and stabilizing agent. The synthesized nanoparticles have been characterized by UV–Vis spectroscopy, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM) and X-ray diffraction (XRD analysis. The presence of a characteristic surface plasmon resonance (SPR) absorption band at 430 nm in UV–Vis reveals the reduction of silver metal ions into silver nanoparticles. Whereas FTIR analysis was performed to probe the possible functional group involved in the synthesis of AgNPs. Further extract and AgNPs were evaluated for antimicrobial activity against different pathogenic microorganisms.

Keywords: antimicrobial, Dioscorea deltoidea, microwave, silver, nanoparticles

Procedia PDF Downloads 269

Authors: Sam Bahreini, Payam Hayati

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Metal-organic coordination [Cu(L)₄(SCN)₂] was synthesized applying ultrasonic irradiation, and its photocatalytic performance for the degradation of Remdesivir (RS) under sunlight irradiation was systematically explored for the first time in this study. The physicochemical properties of the synthesized photocatalyst were investigated using Fourier-transform infrared (FT-IR), field emission scanning electron microscopy (FE-SEM), powder x-ray diffraction (PXRD), energy-dispersive x-ray (EDX), thermal gravimetric analysis (TGA), diffuse reflectance spectroscopy (DRS) techniques. Systematic examinations were carried out by changing irradiation time, temperature, solution pH value, contact time, RS concentration, and catalyst dosage. The photodegradation kinetic profiles were modeled in pseudo-first order, pseudo-second-order, and intraparticle diffusion models reflected that photodegradation onto [Cu(L)₄(SCN)₂] catalyst follows pseudo-first order kinetic model. The fabricated [Cu(L)₄(SCN)₂] nanostructure bandgap was determined as 2.60 eV utilizing the Kubelka-Munk formula from the diffuse reflectance spectroscopy method. Decreasing chemical oxygen demand (COD) (from 70.5 mgL-1 to 36.4 mgL-1) under optimal conditions well confirmed mineralizing of the RS drug. The values of ΔH° and ΔS° was negative, implying the process of adsorption is spontaneous and more favorable in lower temperatures.

Keywords: Photocatalytic degradation, COVID-19, density functional theory (DFT), molecular electrostatic potential (MEP)

Procedia PDF Downloads 169

Authors: M. Jerold, V. Sivasubramanian

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This study reports the removal of Malachite Green (MG) from simulated wastewater by using marine macro algae Ulva lactuca. Batch biosorption experiments were carried out to determine the biosorption capacity. The biosorption capacity was found to be maximum at pH 10. The effect of various other operation parameters such as biosorbent dosage, initial dye concentration, contact time and agitation was also investigated. The equilibrium attained at 120 min with 0.1 g/L of biosorbent. The isotherm experimental data fitted well with Langmuir Model with R² value of 0.994. The maximum Langmuir biosorption capacity was found to be 76.92 mg/g. Further, Langmuir separation factor RL value was found to be 0.004. Therefore, the adsorption is favorable. The biosorption kinetics of MG was found to follow pseudo second-order kinetic model. The mechanistic study revealed that the biosorption of malachite onto Ulva lactuca was controlled by film diffusion. The solute transfer in a solid-liquid adsorption process is characterized by the film diffusion and/or particle diffusion. Thermodynamic study shows ΔG° is negative indicates the feasibility and spontaneous nature for the biosorption of malachite green. The biosorbent was characterized using Scanning Electron Microscopy, Fourier Transform Infrared Spectroscopy, and elemental analysis (CHNS: Carbon, Hydrogen, Nitrogen, Sulphur). This study showed that Ulva lactuca can be used as promising biosorbent for the removal of MG from wastewater.

Keywords: biosorption, Ulva lactuca, wastewater, malachite green, isotherm, kinetics

Procedia PDF Downloads 157

Authors: Marinos Xagoraris, Iliada K. Lappa, Charalambos Kanakis, Dimitra Daferera, Christina Papadopoulou, Georgios Sourounis, Charilaos Giotis, Pavlos Bouchagier, Christos S. Pappas, Petros A. Tarantilis, Efstathia Skotti

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The aim of this work was to recover phenolic compounds from grape skins produced in Greek varieties of the Ionian Islands in order to form the basis of calculations for their further utilization in the context of the circular economy. Isolation and further utilization of phenolic compounds is an important issue in winery by-products. For this purpose, 37 samples were collected, extracted, and analyzed in an attempt to provide the appropriate basis for their sustainable exploitation. Extraction of the bioactive compounds was held using an eco-friendly, non-toxic, and highly effective water-glycerol solvent system. Then, extracts were analyzed using UV-Vis, liquid chromatography-mass spectrometry (LC-MS), FTIR, and Raman spectroscopy. Also, total phenolic content and antioxidant activity were measured. LC-MS chromatography showed qualitative differences between different varieties. Peaks were attributed to monomeric 3-flavanols as well as monomeric, dimeric, and trimeric proanthocyanidins. The FT-IR and Raman spectra agreed with the chromatographic data and contributed to identifying phenolic compounds. Grape skins exhibited high total phenolic content (TPC), and it was proved that during vinification, a large number of polyphenols remained in the pomace. This study confirmed that grape skins from Ionian Islands are a promising source of bioactive compounds, suggesting their utilization under a bio-economic and environmental strategic framework.

Keywords: antioxidant activity, grape skin, phenolic compounds, waste recovery

Procedia PDF Downloads 148

Authors: S. Sharma, U. Batra, S. Kapoor, A. Dua

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In this study, the effects and interactions of reaction time and capping agent assistance during sol-gel synthesis of magnesium substituted hydroxyapatite nanopowder (MgHA) on hydroxyapatite (HA) to β-tricalcium phosphate (β-TCP) ratio, Ca/P ratio and mean crystallite size was examined experimentally as well as through statistical analysis. MgHA nanopowders were synthesized by sol-gel technique at room temperature using aqueous solution of calcium nitrate tetrahydrate, magnesium nitrate hexahydrate and potassium dihydrogen phosphate as starting materials. The reaction time for sol-gel synthesis was varied between 15 to 60 minutes. Two process routes were followed with and without addition of triethanolamine (TEA) in the solutions. The elemental compositions of as-synthesized powders were determined using X-ray fluorescence (XRF) spectroscopy. The functional groups present in the as-synthesized MgHA nanopowders were established through Fourier Transform Infrared Spectroscopy (FTIR). The amounts of phases present, Ca/P ratio and mean crystallite sizes of MgHA nanopowders were determined using X-ray diffraction (XRD). The HA content in biphasic mixture of HA and β-TCP and Ca/P ratio in as-synthesized MgHA nanopowders increased effectively with reaction time of sols (p < 0.0001, two way Anova), however, these were independent of TEA addition (p > 0.15, two way Anova). The MgHA nanopowders synthesized with TEA assistance exhibited 14 nm lower crystallite size (p < 0.018, 2 sample t-test) compared to the powder synthesized without TEA assistance.

Keywords: capping agent, hydroxyapatite, regression analysis, sol-gel, 2- sample t-test, two-way analysis of variance (ANOVA)

Procedia PDF Downloads 370

Authors: Benyapa Suksuwan

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Introduction: Oxidative stress is identified as the root cause of the development and progression of several diseases as the disproportion of free radicals in the body leads to tissue or cell damage. Polyphenols are the most common antioxidant found in plants and are efficient in capturing oxidative free radicals. Aim of the Study: This study focused on the antioxidant activity of polyphenols extracted from Phyllanthus Emblica L. as oxidative stress plays a vital role in developing and progressing many diseases, including cardiovascular diseases and cancer. Materials and Methods: The plant was extracted using a mixture solvent (ethyl alcohol: water in ratio 8:2). The total phenolic content of P. Emblica extract was determined using the Folin-Cioucalteu method and calculated as gallic acid equivalents (GAE) and various antioxidant assays DPPH and ABTS radical scavenging capacity assays. Results and Discussion: The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, the IC₅₀ of P. Emblica extract via DPPH and ABTS assays were 68.10 μg/mL ± 0.455, and 49.24 μg/mL ± 0.716, respectively. Furthermore, P. Emblica extract showed antioxidant activities in a concentration-dependent manner. Vitamin C was used as a positive control in the DPPH assay, while Trolox was used as a positive control in the ABTS assay. Conclusions: In conclusion, P. Emblica extract consisted of a high amount of total phenolic content, which possesses potent antioxidant activity. However, further antioxidant activity assays using human cell lines such as SOD, ROS, and RNS scavenging assays and in vitro antioxidant experiments should be performed in order.

Keywords: antioxidant, ABTS scavenging, DPPH scavenging assay, total phenol contents assay, Phyllanthus Emblica L

Procedia PDF Downloads 195

Authors: Ibrahim Sengor, Sumeyye Cesur, Ilyas Kartal, Faik Nuzhet Oktar, Nazmi Ekren, Ahmet Talat Inan, Oguzhan Gunduz

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In recent years, many researchers focused on nano-size fiber production. Nanofibers have been studied due to their different and superior physical, chemical and mechanical properties. Poly (lactic acid) (PLA), is a type of biodegradable thermoplastic polyester derived from renewable sources used in biomedical owing to its biocompatibility and biodegradability. In addition, zinc oxide is an antibacterial material and hazelnut shell powder is a filling material. In this study, nanofibers were obtained by adding of different ratio Zinc oxide, (ZnO) and hazelnut shell powder at different concentration into Poly (lactic acid) (PLA) by using electrospinning method which is the most common method to obtain nanofibers. After dissolving the granulated polylactic acids in % 1,% 2,% 3 and% 4 with chloroform solvent, they are homogenized by adding tween and hazelnut shell powder at different ratios and then by electrospinning, nanofibers are obtained. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimeter (DSC) and physical analysis such as density, electrical conductivity, surface tension, viscosity measurement and antimicrobial test were carried out after production process. The resulting structures of the nanofiber possess antimicrobial and antiseptic properties, which are attractive for biomedical applications. The resulting structures of the nanofiber possess antimicrobial, non toxic, self-cleaning and rigid properties, which are attractive for biomedical applications.

Keywords: electrospinning, hazelnut shell powder, nanofibers, poly (lactic acid), zinc oxide

Procedia PDF Downloads 163

Authors: Muhammad B. Ibrahim, Muhammad S. Sulaiman, Sadiq Sani

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Neem leaves were studied as plant wastes derived adsorbents for detoxification of Congo Red (CR) and Methyl Orange (MO) from aqueous solutions using batch adsorption technique. The objectives involved determining the effects of the basic adsorption parameters are namely, agitation time, adsorbent dosage, adsorbents particle size, adsorbate loading concentrations and initial pH, on the adsorption process as well as characterizing the adsorbents by determining their physicochemical properties, functional groups responsible for the adsorption process using Fourier Transform Infrared (FTIR) spectroscopy and surface morphology using scanning electron microscopy (SEM) coupled with energy dispersion X – ray spectroscopy (EDS). The adsorption behaviours of the materials were tested against Langmuir, Freundlich, etc. isotherm models. Percent adsorption increased with increase in agitation time (5 – 240 minutes), adsorbent dosage (100-500mg), initial concentration (100-300mg/L), and with decrease in particle size (≥75μm to ≤300μm) of the adsorbents. Both processes are dye pH-dependent, increasing or decreasing percent adsorption in acidic (2-6) or alkaline (8-12) range over the studied pH (2-12) range. From the experimental data the Langmuir’s separation factor (RL) suggests unfavourable adsorption for all processes, Freundlich constant (nF) indicates unfavourable process for CR and MO adsorption; while the mean free energy of adsorption

Keywords: adsorption, congo red, methyl orange, neem leave

Procedia PDF Downloads 364

Authors: Batsukh Chultem, Oyunbileg Natsagdorj, Namsrai Steyrmunkh

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Many industries, tourist camps and houses, discharge aqueous effluents containing relatively high levels of heavy metals, harmful organic compounds water. Untreated effluent from these manufacturing processes has an adverse impact on the environment. A specific problem associated with waste water in the environment is accumulation in the food chain and persistence in the environment. The screening of microorganisms resistant to pollution and able to detoxification them is essential for the development of clean-up technologies. The purpose of this study is to use advanced microbiological technology products for oxidizing organic and heavy metals pollutants as a biological treatment, to reduce water pollution, which arise as a result of waste water due to day-to-day operations of industries and houses of Ulaanbaatar city and tourist camps located around the lake Hovsgol, in Hovsgol province of Mongolia. By comparing the results from tests of effective microorganism’s bio-preparation treated sewage samples and not treated sewage samples shows that the treated sewage samples pollution decreased defending on treatment period and ratio. Treated water analyses show that: the suspended solids 352 mg/l, pH 5.85-7.95, ammonium nitrate 81.25-221.2 mg NH₄/l, nitrite 0.088-0.227 mg NO₂/l, nitrate 8.5-11.5 mg NO₃/l, and orthophosphate 1.06-15.46 mg PO₄/l. Also, heavy metals were decreased and microbiological test results defined parameters, respectively show the waste water pollution was reduced.

Keywords: effective microorganims, environment, pollution, treatment

Procedia PDF Downloads 131

Authors: Mesfin Angaw Tesfay

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L-Xylulose is a potentially valuable rare sugar used as starting material for antiviral and anticancer drug development in pharmaceutical industries. L-Xylulose exist in a very low concentration in nature and have to be synthesized from cheap starting materials such as xylitol through biotechnological approaches. In this study, cofactor engineering and deep eutectic solvent were applied to improve the efficiency of L-xylulose production from xylitol. A water-forming NAD+ regeneration enzyme (NADH oxidase) from Streptococcus mutans ATCC 25175 was introduced into E. coli with xylitol-4-dehydrogenase (XDH) of Pantoea ananatis resulting in recombinant cells harboring the vector pETDuet-xdh-SmNox. Further, three deep eutectic solvents (DES) including, Choline chloride/glycerol (ChCl/G), Choline chloride/urea (ChCl/U), and Choline chloride/ethylene glycol (ChCl/EG) have been employed to facilitate the conversion efficiency of L-xylulose from xylitol. The co-expression system exhibited optimal activity at a temperature of 37 ℃ and pH 8.5, and the addition of Mg2+ enhanced the catalytic activity by 1.19-fold. Co-expression of NADH oxidase with XDH enzyme resulted in increased L-xylulose concentration and productivity from xylitol as well as the intracellular NAD+ concentration. Two of the DES used (ChCl/U and ChCl/EG) show positive effects on product yield and the ChCl/G has inhibiting effects. The optimum concentration of ChCl/U was 2.5%, which increased the L-xylulose yields compared to the control without DES. In a 1 L fermenter the final concentration and productivity of L-xylulose from 50 g/L of xylitol reached 48.45 g/L, and 2.42 g/L.h respectively, which was the highest report. Overall, this study is a suitable approach for large-scale production of L-xylulose from xylitol using the engineered E. coli cell.

Keywords: Xylitol-4-dehydrogenase, NADH oxidase, L-xylulose, Xylitol, Coexpression, DESs

Procedia PDF Downloads 23

Authors: Zahra Asgar Pour

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Two types of Ti-Al-containing zeolitic beads with an average diameter of 450 to 750 µm and hierarchical porosity were synthesized using a hard template method and tested as heterogeneous catalysts in the epoxidation of cycloalkenes (i.e. cyclohexene and cis-cyclooctene) with aqueous hydrogen peroxide (H₂O₂) or tert-butyl hydroperoxide(TBHP) as the oxidant agent. The first type of zeolitic beads was prepared by hydrothermal treatment of a primarygel (containing the Si, Ti, and Al precursors) in the presence of porous anion-exchange resin beads as the hard shaping template. After calcination, these beads (Ti-Al-Beta-HDT-B) consisted of both crystalline zeolite Beta and an amorphous silicate phase. The second type of zeolitic beads (Ti-Beta-PS-deAl-14.4-B) was obtained by post-synthesis dealumination of Al-containing zeolite Beta beads using 14.4 M HNO₃, followed by Ti grafting (3 wt% per gram of zeolite). The prepared materials were characterised by means of XRD, N2-physisorption, UV-vis, XRF, SEM, and TEM and tested as heterogeneous epoxidation catalysts. This post-synthetically prepared catalyst demonstrated higher activity (cyclohexene conversion of 22.7 % and epoxide selectivity of 33.5 %) after 5 h at60 °C, which emanates from the crystalline structure and higher degrees of hydrophobicity. In addition, the post-synthetically prepared beads were prone to partial Ti leaching in the presence of H₂O₂, whereas they showed to be resistant against Ti leaching using tert-butyl hydroperoxide as the oxidant agent.

Keywords: epoxidation, structured catalysts, hierarchical porosity, bead-shape catalysts

Procedia PDF Downloads 108

Authors: Temsiri Suwan, Penpicha Wanachantararak, Sakornrat Khongkhunthian, Siriporn Okonogi

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In the present study, silver nanoparticles (AgNPs) were synthesized by green synthesis approach using Moringa oleifera aqueous extract (ME) as a reducing agent and silver nitrate as a precursor. The obtained AgNPs were characterized using UV-Vis spectroscopy (UV-Vis), dynamic light scattering (DLS), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and X-ray diffractometry (XRD). The results from UV-Vis revealed that the maximum absorption of AgNPs was at 430 nm and the EDX spectrum confirmed Ag element. The results from DLS indicated that the amount of ME played an important role in particle size, size distribution, and zeta potential of the obtained AgNPs. The smallest size (62.4 ± 1.8 nm) with narrow distribution (0.18 ± 0.02) of AgNPs was obtained after using 1% w/v of ME. This system gave high negative zeta potential of -36.5 ± 2.8 mV. SEM results indicated that the obtained AgNPs were spherical in shape. Antibacterial activity using dilution method revealed that the minimum inhibitory and minimum bactericidal concentrations of the obtained AgNPs against Streptococcus mutans were 0.025 and 0.1 mg/mL, respectively. Cytotoxicity test of AgNPs on adenocarcinomic human alveolar basal epithelial cells (A549) indicated that the particles impacted against A549 cells. The percentage of cell growth inhibition was 87.5 ± 3.6 % when only 0.1 mg/mL AgNPs was used. These results suggest that ME is the potential reducing agent for green synthesis of AgNPs.

Keywords: antibacterial activity, Moringa oleifera extract, reducing agent, silver nanoparticles

Procedia PDF Downloads 108

Authors: Kebede Gamo Sebehanie, Olu Emmanuel Femi, Alberto Velázquez Del Rosario, Abubeker Yimam Ali, Gudeta Jafo Muleta

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Water pollution is one of the most serious worldwide issues today. Among water pollution, heavy metals are becoming a concern to the environment and human health due to their non-biodegradability and bioaccumulation. In this study, a magnetite-cellulose nanocomposite derived from renewable resources is employed for hexavalent chromium elimination by adsorption. Magnetite nanoparticles were synthesized directly from iron ore using solvent extraction and co-precipitation technique. Cellulose nanofiber was extracted from sugarcane bagasse using the alkaline treatment and acid hydrolysis method. Before and after the adsorption process, the MNPs-CNF composites were evaluated using X-ray diffraction (XRD), Scanning electron microscope (SEM), Fourier transform infrared (FTIR), and Vibrator sample magnetometer (VSM), and Thermogravimetric analysis (TGA). The impacts of several parameters such as pH, contact time, initial pollutant concentration, and adsorbent dose on adsorption efficiency and capacity were examined. The kinetic and isotherm adsorption of Cr (VI) was also studied. The highest removal was obtained at pH 3, and it took 80 minutes to establish adsorption equilibrium. The Langmuir and Freundlich isotherm models were used, and the experimental data fit well with the Langmuir model, which has a maximum adsorption capacity of 8.27 mg/g. The kinetic study of the adsorption process using pseudo-first-order and pseudo-second-order equations revealed that the pseudo-second-order equation was more suited for representing the adsorption kinetic data. Based on the findings, pure MNPs and MNPs-CNF nanocomposites could be used as effective adsorbents for the removal of Cr (VI) from wastewater.

Keywords: magnetite-cellulose nanocomposite, hexavalent chromium, adsorption, sugarcane bagasse

Procedia PDF Downloads 129

Authors: Venkat Garigapati

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Cell-based therapies are limited due to underlying host immune system activity. Microencapsulation of living cells to overcome this issue has some serious drawbacks, such as limitations of nutrient and oxygen diffusion, which pose a threat to the function and longevity of cells. The conformal coating could overcome the issues which are generally involved in traditional microencapsulation. Some of the theoretical advantages of conformal coating include superior nutrient and oxygen supply to cells, prolonged lifespan, improved drug-secreting cell functionality and an opportunity to load high cell doses in small volumes. Despite several advantages to the conformal coating, there are no suitable methods available to apply to living cells. The ultra-thin conformal coating was achieved utilizing click-reactive methacryloyloxyethyl phosphorylcholine (MPC) polymers, which are capable of specifically reacting one polymer to another at neutral pH in the aqueous isotonic system at the desired temperature suitable for living cells without the need of deleterious initiators. ARPE-19 (Adult Retinal Pigment Epithelial cell line-19) cell-spheroids and rat pancreatic islets were used in the formulation studies. The in vitro studies of coated ARPE-19 cell-spheroids and rat islets indicate that the coat was intact; cells were viable and functioning. The in vitro study results revealed that the conformal coating technology seems promising and in vivo studies are being planned.

Keywords: cells, hydrogel, conformal coating, microencapsulation, insulin

Procedia PDF Downloads 90

Authors: Waleed A. El-Said, Dina M. Fouad, Mohamed H. Aly, Mohamed A. El-Gahami

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Green synthesis of nanomaterials has received increasing attention as an eco-friendly technology in materials science. Here, we have used two types of extractions from green tea leaf (i.e. total extraction and tannin extraction) as reducing agents for a rapid, simple and one step synthesis method of mesoporous silica nanoparticles (MSNPs)/iron oxide (Fe3O4) nanocomposite based on deposition of Fe3O4 onto MSNPs. MSNPs/Fe3O4 nanocomposite were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, energy dispersive X-ray, vibrating sample magnetometer, N2 adsorption, and high-resolution transmission electron microscopy. The average mesoporous silica particle diameter was found to be around 30 nm with high surface area (818 m2/gm). MSNPs/Fe3O4 nanocomposite was used for removing lindane pesticide (an environmental hazard material) from aqueous solutions. Fourier transform infrared, UV-vis, High-performance liquid chromatography and gas chromatography techniques were used to confirm the high ability of MSNPs/Fe3O4 nanocomposite for sensing and capture of lindane molecules with high sorption capacity (more than 89%) that could develop a new eco-friendly strategy for detection and removing of pesticide and as a promising material for water treatment application.

Keywords: green synthesis, mesoporous silica, magnetic iron oxide NPs, adsorption Lindane

Procedia PDF Downloads 436

Authors: Mohamed M. Ibrahima, Abdul Aziz A.AL Sahli, Ibrahim A. Alaraidh, Ali A. Al-Homaidan, E.M. Mostafa, G.A. EL-Gaaly

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Traditionally, in Middle Eastern countries, many cultures use chewing sticks of arak for medicinal purposes especially, for oral cleanliness care. It was used by Muslims for the treatment of teeth and highly recommended to be used by muslims during the whole day. Therefore, the present work aimed to determine the total phenolic content and total flavonoids in two Miswak extracts obtained from arak roots collected from two different localities in Saudi Arabia. They were extracted with aqueous ethanol (80%) and used to estimate in vitro their antioxidative abilities. The new findings showed that the two tested extracts contained significantly different amounts of both total phenolic content and total flavonoids. According to the increase of total phenolic contents and total flavonoids obtained from the two extracts, Miswak collected from the southern region was found to contain more contents than those collected from the middle region. The results of antioxidant activities of Miswak root extract obtained by using different in vitro methods were varied depending on the technique used. According to the malondialdehyde (MDA) method, hydrogen peroxide (H2O2) scavenging ability and 1,1-diphenyl-2-picrylhydrazyl (DPPH) methods, the two Miswak extracts exhibited to have high to very high antioxidant activities. Mostly, the values of antioxidant activities of Southern region have been shown to be always the highest.

Keywords: Arak, antioxidant, medicinal plants, Saudi Arabia

Procedia PDF Downloads 534

Authors: Yao Xing, Hong Ling Liu, Wei Dong Yu

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With the increase of global population, it is of importance for the safe water supply, while, the water-monitoring method with the capability of rapidness, low-cost, green and robustness remains unsolved. In this paper, gold nanoclusters-wool keratin is added into copper ions measured by fluorescent method in order to probe copper ions in aqueous solution. The fluorescent results show that gold nanoclusters-wool keratin exhibits high stability of pHs, while it is sensitive to temperature and time. Based on Gauss fitting method, the results exhibit that the slope of gold nanoclusters-wool keratin with pH resolution under acidic condition is higher compared to it under alkaline solutions. Besides, gold nanoclusters-wool keratin added into copper ions shows a fluorescence turn-off response transferring from red to blue under UV light, leading to the dramatically decreased fluorescent intensity of gold nanoclusters-wool keratin solution located at 690 nm. Moreover, the limited concentration of copper ions tested by gold nanoclusters-wool keratin system is around 1 µmol/L, which meets the need of detection standards. The fitting slope of Stern-Volmer plot at low concentration of copper ions is larger than it at high concentrations, which indicates that aggregated gold nanoclusters are from small amounts to large numbers with the increasing concentration of copper ions. It is expected to provide novel method and materials for copper ions testing with low cost, high efficiency, and easy operability.

Keywords: gold nanoclusters, copper ions, wool keratin, fluorescence

Procedia PDF Downloads 252

Authors: Muhammad Ajmal, Muhammad Siddiq, Nurettin Sahiner

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We prepared poly(methacrylic acid-co-acrylonitrile) (p(MAc-co-AN)) microgels by inverse suspension polymerization, and converted the nitrile groups into amidoxime groups to obtain more hydrophilic amidoximated poly(methacrylic acid-co-acrylonitile) (amid-p(MAc-co-AN)) microgels. Amid-microgels were used as microreactors for in situ synthesis of copper and cobalt nanoparticles. Cu (II) and Co (II) ions were loaded into microgels from their aqueous metal salt solutions and then converted to corresponding metal nanoparticle (MNP) by treating the loaded metal ions with sodium borohydride (NaBH4). The characterization of the prepared microgels and microgel metal nanoparticle composites was carried out by SEM, TEM and TG analysis. The amounts of metal nanoparticles within microgels were estimated by AAS measurements by dissolving the MNP entrapped within microgels by concentrated HCl acid treatment. Catalytic performances of the prepared amid-p(MAc-co-AN)-M (M: Cu, Co) microgel composites were investigated by using them as catalyst for the degradation of cationic and anionic organic dyes such as eosin Y (EY), methylene blue (MB) and methyl Orange (MO), and for the reduction of nitro aromatic pollutants like 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP) to their corresponding amino phenols. Here, we also report for the first time, the simultaneous degradation/reduction of MB, EY, and 4-NP by amid-p(MAc-co-AN)-Cu microgel composites. Different parameters affecting the reduction rates such as metal types, amount of catalysts, temperature and the amount of reducing agent were investigated.

Keywords: microgels, nanoparticles, catalyst, pollutants

Procedia PDF Downloads 356

Authors: Asif Jamal, Samia Sakindar, Ramla Rehman

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Biosurfactants are amphiphilic surface active compounds obtained from natural resources such as plants and microorganisms. Because of their diverse physicochemical characteristics biosurfactant are replacing synthetic compounds in various commercial applications. In present study, a strain of P. aeruginosa was isolated from crude oil contaminated soil as efficient biosurfactant producers. The biosurfactant production was analyzed as a function of surface tension reduction, oil spreading capacity, emulsification index and hemolysis assay. This bacterial strain showed excellent emulsion activity of EI24 85%, surface tension reduction up to 28.6 mNm-1 and 7.0 mm oil displacement zone. Physicochemical and biological properties of extracted rhamnolipid were also investigated in current study. The chemical composition of product from strain PSS was analyzed by FTIR spectroscopy. The results revealed that extracted biosurfactant was rhamnolipid type in nature having RL-1 and RL-2 homologues. The surface behavior of rhamnolipid in aqueous phase was investigated varying extreme pH, temperature, salt conditions and with various hydrocarbons. The results indicated that biosurfactant produced by strain PSS Which showed stability during high temperature up to 121 C, salt concentrations up to 20% and pH range between (4—14). The emulsification activity with different hydrocarbons was also remarkable. It was concluded that rhamnolipid biosurfactant produced by strain PSS has excellent potential as emulsifying/remediation agent for broad range of hydrophobic pollutants.

Keywords: P. aeruginosa, bioremediation, rhamnolipid, surfactants

Procedia PDF Downloads 281

Authors: Fariha Akhter Chowdhury, Mohammad Nurul Islam, Anamika Saha, Sabrina Mahboob, Abu Syed Md. Mosaddek, Md. Omar Faruque, Most. Fahmida Begum, Rajib Bhattacharjee

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Urinary tract infection (UTI) is one of the most common infectious diseases in Bangladesh where Escherichia coli is the prevalent organism and responsible for most of the infections. Lipopolysaccharide (LPS) is known to act as a major virulence factor of E. coli. The present study aimed to purify, extract and visualize LPS of E. coli clinical isolates from urine samples of patients with UTI. The E. coli strain was isolated from the urine samples of 10 patients with UTI and then the antibiotic sensitivity pattern of the isolates was determined. The purification of LPS was carried out using the hot aqueous-phenol method and separated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, which was directly stained using the modified silver staining method and Coomassie blue. The silver-stained gel demonstrated both smooth and rough type LPS by showing trail-like band patterns with the presence and lacking O-antigen region, respectively. Coomassie blue staining showed no band assuring the absence of any contaminating protein. Our successful extraction of purified LPS from E. coli isolates of UTI patients’ urine samples can be an important step to understand the UTI disease conditions.

Keywords: Escherichia coli, electrophoresis, polyacrylamide gel, silver staining, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE)

Procedia PDF Downloads 389

Authors: Malgorzata J. Rybak-Smith, Benedicte Thiebaut, Simon Johnson, Peter Bishop, Helen E. Townley

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Gadolinium doped titania (TiO2:Gd) nanoparticles (NPs) can be activated by X-ray radiation to generate Reactive Oxygen Species (ROS), which can be effective in killing cancer cells. As such, treatment with these NPs can be used to enhance the efficacy of conventional radiotherapy. Incorporation of the NPs in to tumour tissue will permit the extension of radiotherapy to currently untreatable tumours deep within the body, and also reduce damage to neighbouring healthy cells. In an attempt to find a fast and scalable method for the synthesis of the TiO2:Gd NPs, the use of Flame Spray Pyrolysis (FSP) was investigated. A series of TiO2 NPs were generated with 1, 2, 5 and 7 mol% gadolinium dopant. Post-synthesis, the TiO2:Gd NPs were silica-coated to improve their biocompatibility. Physico-chemical characterisation was used to determine the size and stability in aqueous suspensions of the NPs. All analysed TiO2:Gd NPs were shown to have relatively high photocatalytic activity. Furthermore, the FSP synthesized silica-coated TiO2:Gd NPs generated enhanced ROS in chemico. Studies on rhabdomyosarcoma (RMS) cell lines (RD & RH30) demonstrated that in the absence of irradiation all TiO2:Gd NPs were inert. However, application of TiO2:Gd NPs to RMS cells, followed by irradiation, showed a significant decrease in cell proliferation. Consequently, our studies showed that the X-ray-activatable TiO2:Gd NPs can be prepared by a high-throughput scalable technique to provide a novel and affordable anticancer therapy.

Keywords: cancer, gadolinium, ROS, titania nanoparticles, X-ray

Procedia PDF Downloads 431

Authors: Reetika Sharma, Lalit Tejwani, Himanshu Shekhar, Arun Singhvi

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Purpose: To describe a novel technique of trabeculectomy targeting triple modulation on wound healing to increase the overall success rate. Method: Ten eyes of 10 patients underwent trabeculectomy with subconjunctival mitomycin C (0.4mg/ml for 4 minutes) application combined with Ologen implantation subconjunctivally and subsclerally. Five of these patients underwent additional phacoemulsification with intraocular lens implantation. The Ologen implant was wet with 0.1 ml Bevacizumab. Result: All the eyes achieved target intraocular pressure (IOP), which was maintained until one year of follow-up. Two patients needed anterior chamber reformation at day two post surgery. One patient needed cataract surgery after four months of surgery and achieved target intraocular pressure on two topical antiglaucoma medicines. Conclusion: Vascular endothelial growth factor (VEGF) concentration has been seen to increase in the aqueous humor after filtration surgery. Ologen implantation helps in collagen remodelling, antifibroblastic response, and acts as a spacer. Bevacizumab augmented Ologen, in addition, targets the increased VEGF and helps in decreasing scarring. Anti-VEGF augmented Ologen in trabeculectomy with mitomycin C (MMC) hence appears to have encouraging short-term intraocular pressure control.

Keywords: ologen, anti-VEGF, trabeculectomy, scarring

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Authors: Mohamed Benaicha, Mahdi Allam

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A new two stage electrochemical process as a safe, large area and low processing cost technique for the production of semi-conducting CuInSe2 (CIS) thin films is studied. CuIn precursors were first potentiostatically electrodeposited onto molybdenum substrates from an acidic thiocyanate electrolyte. In a second stage, the prepared metallic CuIn layers were used as substrate in the selenium electrochemical deposition system and subjected to a thermal treatment in vacuum atmosphere, to eliminate binary phase formation by reaction of the Cu2-x Se and InxSey selenides, leading to the formation of CuInSe2 thin film. Electrochemical selenization from aqueous electrolyte is introduced as an alternative to toxic and hazardous H2Se or Se vapor phase selenization used in physical techniques. In this study, the influence of film deposition parameters such as bath composition, temperature and potential on film properties was studied. The electrochemical, morphological, structural and compositional properties of electrodeposited thin films were characterized using various techniques. Results of Cyclic and Stripping-Cyclic Voltammetry (CV, SCV), Scanning Electron Microscopy (SEM) and Energy Dispersive X-Ray microanalysis (EDX) investigations revealed good reproducibility and homogeneity of the film composition. Thereby optimal technological parameters for the electrochemical production of CuIn, Se as precursors for CuInSe2 thin layers are determined.

Keywords: photovoltaic, CIGS, copper alloys, electrodeposition, thin films

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Authors: G. Anusha, J. Raja Murugadoss

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In recent years, the problem of water contaminant is drastically increasing due to the disposal of industrial wastewater containing iron, fluoride, mercury, lead, cadmium, phosphorus, silver etc. into water bodies. The non-biodegradable heavy metals could accumulate in the human system through food chain and cause various dreadful diseases and permanent disabilities and in worst cases it leads to casual losses. Further, the presence of the excess quantity of such heavy metals viz. Lead, Cadmium, Chromium, Nickel, Zinc, Copper, Iron etc. seriously affect the natural quality of potable water and necessitates the treatment process for removal. Though there are dozens of standard procedures available for the removal of heavy metals, their cost keeps the industrialists away from adopting such technologies. In the present work, an attempt has been made to remove such contaminants particularly fluoride and to study the efficiency of the removal of fluoride by adsorption using a new agro-based materials namely Limonia acidissima and Emblica officinalis which is commonly referred as wood apple and gooseberry respectively. Accordingly a set of experiments has been conducted using batch and column processes, with the help of activated carbon prepared from the shell of wood apple and seeds of gooseberries. Experiments reveal that the adsorption capacity of the shell of wood apple is significant to yield promising solutions.

Keywords: adsorption, fluoride, agro-based waste materials, Limonia acidissima, Emblica officinalis

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Authors: Wen-Wen Wang, Qian Ye, Yi-Feng Lin

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Carbon dioxide emissions are expected to increase continuously, resulting in climate change and global warming. As a result, CO₂ capture has attracted a large amount of research attention. Among the various CO₂ capture methods, membrane technology has proven to be highly efficient in capturing CO₂, because it can be scaled up, low energy consumptions and small area requirements for use by the gas separation. Various nanofibrous membranes were successfully prepared by a simple electrospinning process. The membrane contactor combined with chemical absorption and membrane process in the post-combustion CO₂ capture is used in this study. In a membrane contactor system, the highly porous and water-repellent nanofibrous membranes were used as a gas-liquid interface in a membrane contactor system for CO₂ absorption. In this work, we successfully prepared the polyvinylidene fluoride (PVDF) porous membranes with an electrospinning process. Afterwards, the as-prepared water-repellent PVDF porous membranes were used for the CO₂ capture application. However, the pristine PVDF nanofibrous membranes were wetted by the amine absorbents, resulting in the decrease in the CO₂ absorption flux, the hydrophobic polydimethylsiloxane (PDMS) materials were added into the PVDF nanofibrous membranes to improve the solvent resistance of the membranes. To increase the hydrophobic properties and CO₂ absorption flux, more hydrophobic surfaces of the PDMS/PVDF nanofibrous membranes are obtained by the grafting of fluoroalkylsilane (FAS) on the membranes surface. Furthermore, the highest CO₂ absorption flux of the PDMS/PVDF nanofibrous membranes is reached after the FAS modification with four times. The PDMS/PVDF nanofibrous membranes with 60 wt% PDMS addition can be a long and continuous operation of the CO₂ absorption and regeneration experiments. It demonstrates the as-prepared PDMS/PVDF nanofibrous membranes could potentially be used for large-scale CO₂ absorption during the post-combustion process in power plants.

Keywords: CO₂ capture, electrospinning process, membrane contactor, nanofibrous membranes, PDMS/PVDF

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Authors: Mozhgan Chaichi, Farhad Sharif, Saeede Mazinani

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Polymer nanocomposites are a new class of materials for fabricating future multifunctional and lightweight structures. To obtain good mechanical, thermal and electrical properties, it is essential to achieve uniform dispersion of nanoparticles in polymer matrix. Alignment of nanoparticles in matrix can enhance mechanical, thermal, electrical and barrier properties of nanocomposites in oriented direction. Fe3O4 nanoparticles have generated huge activity in many areas of science and engineering due to its magnetic properties. Magnetic nanoparticles have been investigated for a wide range of applications in sensors, magnetic energy storage, environmental remediation, heterogeneous catalysts and drug delivery. The magnetic response from the Fe3O4 nanoparticles can facilitate with the alignment of nanofillers in a polymer matrix under magnetic field, aiming at fabricating composites with directional properties and functions. Here we report oriented nanocomposites based on Fe3O4 nanoparticles and poly (vinyl alcohol) (PVA), which prepared via a facile aqueous solution by applying a low external magnetic field (750 G). A significant enhancement of mechanical properties, and especially toughness of nanofilms, of oriented PVA/ Fe3O4 nanocomposites is obtained at low nanoparticles loading. Orientation of nanoparticles can align polymer chains and enhance mechanical properties. For example, orientation of 0.1 wt. % Fe3O4 nanoparticles increase 31% toughness and 23% modulus of oriented nanocomposite in compare of pure films, which indicate good dispersion of nanoparticles and efficient load transfer between nanoparticles and matrix.

Keywords: magnetic nanoparticles, nanocomposites, toughness, orientation

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Authors: Rajesh Kumar Meena, Suman Jhajharia, Goutam Chakraborty

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Plasmonic silver nanoparticles (Ag NPs) was synthesized by chemical reduction method using Trachyspermum Ammi (TA, Ajwain) seeds extract in aqueous medium and AgNO3 solution at different time interval. Reaction time, and concentration of AgNO3 and TA could accelerate the reduction rate of Ag+ and affect AgNPs size and concentration of NPs. Surface plasmon resonance band centered at 420-430 nm (88.78nm) was recognised as first exitonic peak of UV-Vis absorption spectra of AgNPs that used to calculate the particle size (10-30 nm). FTIR results TA supported AgNPs showed decrease in intensity of peaks at 3394, 1716 and 1618 cm-1 with respect to the plain TA indicating the involvement of O-H, carbonyl group and C=C stretching in formation of TA-AgNPs aggregates. The C-O-C and C-N stretching suggested the presence of many phytochemicals on the surface of the NPs. Impedance study reveals that at low concentration of TA the rate of charge transfer is in TA-AgNPs aggregates, found higher than the higher TA concentration condition that confirms the stability of AgNPs in water. Extract reduce silver ions into silver nanoparticles (NPs) of size 6-50nm. Pronounce effect of the time on Ag NPs concentration and particle size, was exhibited by the system These biogenic Ag NPs are characterized using UV- Vis spectrophotometry (UV-Visible), Fourier transformation infrared (FTIR) and XRD. These studies give us inside view of the most probable mechanism of biosynthesis and optoelectronic properties of the as synthesised Ag NPs.

Keywords: antimicrobial activity, bioreduction, capping agent, silver nanoparticles

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Authors: Jafar Akbari

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Quinolines are very important compounds partially because of their pharmacological properties which include wide applications in medicinal chemistry. notable among them are antimalarial drugs, anti-inflammatory agents, antiasthamatic, antibacterial, antihypertensive, and tyrosine kinase inhibiting agents. Despite quinoline usage in pharmaceutical and other industries, comparatively few methods for their preparation have been reported.The Friedlander annulation is one of the simplest and most straightforward methods for the synthesis of poly substituted quinolines. Although, modified methods employing lewis or br¢nsted acids have been reported for the synthesis of quinolines, the development of water stable acidic catalyst for quinoline synthesis is quite desirable. One of the most remarkable features of ionic liquids is that the yields can be optimized by changing the anions or the cations. Recently, sulfonic acid functionalized ionic liquids were used as solvent-catalyst for several organic reactions. We herein report the one pot domino approach for the synthesis of quinoline derivatives in Friedlander manner using TSIL as a catalyst. These ILs are miscible in water, and their homogeneous system is readily separated from the reaction product, combining advantages of both homogeneous and heterogeneous catalysis. In this reaction, the catalyst plays a dual role; it ensures an effective condensation and cyclization of 2-aminoaryl ketone with second carbonyl group and it also promotes the aromatization to the final product. Various types of quinolines from 2-aminoaryl ketones and β-ketoesters/ketones were prepared in 85-98% yields using the catalytic system of SO3-H functionalized ionic liquid/H2O. More importantly, the catalyst could be easily recycled for five times without loss of much activity.

Keywords: antimalarial drugs, green chemistry, ionic liquid, quinolines

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Authors: Afrah E. Mohammed, Mudawi M. Nour

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Environmentally friendly green synthesis of nanomaterial has a very significant part in nanotechnology. In the present research, the synthesis of silver nanoparticles (AgNPs) was established by treating silver ions with the aqueous extract of Calligonum comosum green shoots at room temperature. AgNPs formation was firstly detected by the colour change of mixed extract (plant extract and AgNO3). Further characterization was done by ultraviolet (UV)-Vis spectrophotometer, transmission electron microscopy (TEM), scanning electron microscopy (SEM), zeta potential and fourier transform infrared spectroscopy (FTIR). The peak values for UV-VIS- spectroscopy were in the range of 440 nm, TEM micrograph showed a spherical shape for the particles and zeta potential showed the formation of negative charged nanoparticles with an average size of about 105.8 nm. 1635.41 and 3249.83 cm−1 are the peaks detected from the FTIR analysis. In this study, biosynthesized silver nanoparticles mediated by C. comosum were tested for their antimycotic activity using a well diffusion method against fungal species; Aspergillus flavus, Penicillium sp, Fusarium oxysporum. Our findings indicated that biosynthesized AgNPs showed an efficient antimycotic activity against tested species. The antimycotic action of AgNPs varied according to different fungal species. Results confirmed the ability of C. comosum green shoot extract to act as an reducing and stabilizing agent during the synthesis of AgNPs.

Keywords: AGNPS, zeta potential, TEM, SEM

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Authors: Jaspal Rana, Varinder Singh

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Oxidative stress has been identified as an underlying cause of ischemia-reperfusion (IR) related cognitive dysfunction and brain damage. Therefore, antioxidant based therapies to treat IR injury are being investigated. Allium cepa L. (onion) is used as culinary medicine and is documented to have marked antioxidant effects. Hence, the present study was designed to evaluate the effect of A. cepa outer scale extract (ACE) against IR induced cognition and biochemical deficit in mice. ACE was prepared by maceration with 70% methanol and fractionated into ethylacetate and aqueous fractions. Bilateral common carotid artery occlusion for 10 min, followed by 24 h reperfusion, was used to induce cerebral IR injury. Following IR injury, ACE (100 and 200 mg/kg) was administered orally to animals for 7 days once daily. Behavioral outcomes (memory and sensorimotor functions) were evaluated using Morris water maze and neurological severity score. Cerebral infarct size, brain thiobarbituric acid reactive species, reduced glutathione, and superoxide dismutase activity were also determined. Treatment with ACE significantly ameliorated IR mediated deterioration of memory and sensorimotor functions and rose in brain oxidative stress in animals. The results of the present investigation revealed that ACE improved functional outcomes after cerebral IR injury which may be attributed to its antioxidant properties.

Keywords: allium cepa, cerebral ischemia, memory, sensorimotor

Procedia PDF Downloads 114