Search results for: fatty acid methyl ester
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3880

Search results for: fatty acid methyl ester

1420 Methodology for Risk Assessment of Nitrosamine Drug Substance Related Impurities in Glipizide Antidiabetic Formulations

Authors: Ravisinh Solanki, Ravi Patel, Chhaganbhai Patel

Abstract:

Purpose: The purpose of this study is to develop a methodology for the risk assessment and evaluation of nitrosamine impurities in Glipizide antidiabetic formulations. Nitroso compounds, including nitrosamines, have emerged as significant concerns in drug products, as highlighted by the ICH M7 guidelines. This study aims to identify known and potential sources of nitrosamine impurities that may contaminate Glipizide formulations and assess their presence. By determining observed or predicted levels of these impurities and comparing them with regulatory guidance, this research will contribute to ensuring the safety and quality of combination antidiabetic drug products on the market. Factors contributing to the presence of genotoxic nitrosamine contaminants in glipizide medications, such as secondary and tertiary amines, and nitroso group-complex forming molecules, will be investigated. Additionally, conditions necessary for nitrosamine formation, including the presence of nitrosating agents, and acidic environments, will be examined to enhance understanding and mitigation strategies. Method: The methodology for the study involves the implementation of the N-Nitroso Acid Precursor (NAP) test, as recommended by the WHO in 1978 and detailed in the 1980 International Agency for Research on Cancer monograph. Individual glass vials containing equivalent to 10mM quantities of Glipizide is prepared. These compounds are dissolved in an acidic environment and supplemented with 40 mM NaNO2. The resulting solutions are maintained at a temperature of 37°C for a duration of 4 hours. For the analysis of the samples, an HPLC method is employed for fit-for-purpose separation. LC resolution is achieved using a step gradient on an Agilent Eclipse Plus C18 column (4.6 X 100 mm, 3.5µ). Mobile phases A and B consist of 0.1% v/v formic acid in water and acetonitrile, respectively, following a gradient mode program. The flow rate is set at 0.6 mL/min, and the column compartment temperature is maintained at 35°C. Detection is performed using a PDA detector within the wavelength range of 190-400 nm. To determine the exact mass of formed nitrosamine drug substance related impurities (NDSRIs), the HPLC method is transferred to LC-TQ-MS/MS with the same mobile phase composition and gradient program. The injection volume is set at 5 µL, and MS analysis is conducted in Electrospray Ionization (ESI) mode within the mass range of 100−1000 Daltons. Results: The samples of NAP test were prepared according to the protocol. The samples were analyzed using HPLC and LC-TQ-MS/MS identify possible NDSRIs generated in different formulations of glipizide. It was found that the NAP test generated a various NDSRIs. The new finding, which has not been reported yet, discovered contamination of Glipizide. These NDSRIs are categorised based on the predicted carcinogenic potency and recommended its acceptable intact in medicines. The analytical method was found specific and reproducible.

Keywords: NDSRI, nitrosamine impurities, antidiabetic, glipizide, LC-MS/MS

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1419 Artificial Cells Capable of Communication by Using Polymer Hydrogel

Authors: Qi Liu, Jiqin Yao, Xiaohu Zhou, Bo Zheng

Abstract:

The first artificial cell was produced by Thomas Chang in the 1950s when he was trying to make a mimic of red blood cells. Since then, many different types of artificial cells have been constructed from one of the two approaches: a so-called bottom-up approach, which aims to create a cell from scratch, and a top-down approach, in which genes are sequentially knocked out from organisms until only the minimal genome required for sustaining life remains. In this project, bottom-up approach was used to build a new cell-free expression system which mimics artificial cell that capable of protein expression and communicate with each other. The artificial cells constructed from the bottom-up approach are usually lipid vesicles, polymersomes, hydrogels or aqueous droplets containing the nucleic acids and transcription-translation machinery. However, lipid vesicles based artificial cells capable of communication present several issues in the cell communication research: (1) The lipid vesicles normally lose the important functions such as protein expression within a few hours. (2) The lipid membrane allows the permeation of only small molecules and limits the types of molecules that can be sensed and released to the surrounding environment for chemical communication; (3) The lipid vesicles are prone to rupture due to the imbalance of the osmotic pressure. To address these issues, the hydrogel-based artificial cells were constructed in this work. To construct the artificial cell, polyacrylamide hydrogel was functionalized with Acrylate PEG Succinimidyl Carboxymethyl Ester (ACLT-PEG2000-SCM) moiety on the polymer backbone. The proteinaceous factors can then be immobilized on the polymer backbone by the reaction between primary amines of proteins and N-hydroxysuccinimide esters (NHS esters) of ACLT-PEG2000-SCM, the plasmid template and ribosome were encapsulated inside the hydrogel particles. Because the artificial cell could continuously express protein with the supply of nutrients and energy, the artificial cell-artificial cell communication and artificial cell-natural cell communication could be achieved by combining the artificial cell vector with designed plasmids. The plasmids were designed referring to the quorum sensing (QS) system of bacteria, which largely relied on cognate acyl-homoserine lactone (AHL) / transcription pairs. In one communication pair, “sender” is the artificial cell or natural cell that can produce AHL signal molecule by synthesizing the corresponding signal synthase that catalyzed the conversion of S-adenosyl-L-methionine (SAM) into AHL, while the “receiver” is the artificial cell or natural cell that can sense the quorum sensing signaling molecule form “sender” and in turn express the gene of interest. In the experiment, GFP was first immobilized inside the hydrogel particle to prove that the functionalized hydrogel particles could be used for protein binding. After that, the successful communication between artificial cell-artificial cell and artificial cell-natural cell was demonstrated, the successful signal between artificial cell-artificial cell or artificial cell-natural cell could be observed by recording the fluorescence signal increase. The hydrogel-based artificial cell designed in this work can help to study the complex communication system in bacteria, it can also be further developed for therapeutic applications.

Keywords: artificial cell, cell-free system, gene circuit, synthetic biology

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1418 Essential Oil Contents of Endemic Species Astragalus monspessulanus L. ssp. illyricus (Bernhardt) Chater

Authors: Nada Bezić, Valerija Dunkić, Rušćić Mirko

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Astragalus monspessulanus L. ssp. illyricus (Bernhardt) Chater is endemic species of Fabaceae family and belongs to hemicryptophyte. This plant grows wild in the sub-Mediterranean area. We analyzed the composition of the essential oil of stems and leaves of A. monspessulanus L. ssp. Illyricus, collected in Tijarica, near Split, Croatia. Water distilled essential oils from aerial parts of investigation plant have been analysed by GC and GC/MS using VF-5ms capillary column. The total yield of oil was 0.08%, based on dry weight of samples. Thirty-eight compounds were representing 88.5% of the total oil. This essential oil was characterized by a high concentration of cis-myrtanol (20.5%), geranyl acetate (9.6%) and phytone (6.6%). Previous research in the species A. monspessulanus have included flavoalkaloids and flavonoids composition. The present study gives additional knowledge about secondary metabolites contents on the genus Astragalus.

Keywords: essential oil, isovaleric acid, Valeriana tuberosa, geranyl acetate, phytone

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1417 Lung Parasites in Stone Martens (Martes foina L.) from Bulgaria

Authors: Vassilena Dakova, Mariana Panayotova-Pencheva

Abstract:

The present work focused on the study of pulmonary helminth-fauna of the stone marten in Bulgaria in terms of which the data are little. For the purpose, four stone martens were helminthologically necropsied according to the common technique. In addition, some of the injured lung parts were investigated after their boiling in lactic acid and subsequent compression. Four nematode species from different families of order Strongylida and Trichocephalida were found in the lungs. These were Crenosoma petrowi Morosov, 1939; Eucoleus aerophilus Creplin, 1839; Filaroides martis Werner, 1782 and Sobolevingylus petrowi Romanov, 1952. Some of the parasite structures with taxonomic importance were measured and described. According to our best knowledge, the species F. martis and S. petrowi are recorded for the first time as a part of the helminth-fauna of Southeast Europe and Bulgaria in particular.

Keywords: Bulgaria, Crenosoma petrowi, Eucoleus aerophilus, Filaroides martis, lung parasites, Sobolevingylus petrowi, stone martens

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1416 Synthesis and Characterization of pH-Responsive Nanocarriers Based on POEOMA-b-PDPA Block Copolymers for RNA Delivery

Authors: Bruno Baptista, Andreia S. R. Oliveira, Patricia V. Mendonca, Jorge F. J. Coelho, Fani Sousa

Abstract:

Drug delivery systems are designed to allow adequate protection and controlled delivery of drugs to specific locations. These systems aim to reduce side effects and control the biodistribution profile of drugs, thus improving therapeutic efficacy. This study involved the synthesis of polymeric nanoparticles, based on amphiphilic diblock copolymers, comprising a biocompatible, poly (oligo (ethylene oxide) methyl ether methacrylate (POEOMA) as hydrophilic segment and a pH-sensitive block, the poly (2-diisopropylamino)ethyl methacrylate) (PDPA). The objective of this work was the development of polymeric pH-responsive nanoparticles to encapsulate and carry small RNAs as a model to further develop non-coding RNAs delivery systems with therapeutic value. The responsiveness of PDPA to pH allows the electrostatic interaction of these copolymers with nucleic acids at acidic pH, as a result of the protonation of the tertiary amine groups of this polymer at pH values below its pKa (around 6.2). Initially, the molecular weight parameters and chemical structure of the block copolymers were determined by size exclusion chromatography (SEC) and nuclear magnetic resonance (1H-NMR) spectroscopy, respectively. Then, the complexation with small RNAs was verified, generating polyplexes with sizes ranging from 300 to 600 nm and with encapsulation efficiencies around 80%, depending on the molecular weight of the polymers, their composition, and concentration used. The effect of pH on the morphology of nanoparticles was evaluated by scanning electron microscopy (SEM) being verified that at higher pH values, particles tend to lose their spherical shape. Since this work aims to develop systems for the delivery of non-coding RNAs, studies on RNA protection (contact with RNase, FBS, and Trypsin) and cell viability were also carried out. It was found that they induce some protection against constituents of the cellular environment and have no cellular toxicity. In summary, this research work contributes to the development of pH-sensitive polymers, capable of protecting and encapsulating RNA, in a relatively simple and efficient manner, to further be applied on drug delivery to specific sites where pH may have a critical role, as it can occur in several cancer environments.

Keywords: drug delivery systems, pH-responsive polymers, POEOMA-b-PDPA, small RNAs

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1415 Treatment with Triton-X 100: An Enhancement Approach for Cardboard Bioprocessing

Authors: Ahlam Said Al Azkawi, Nallusamy Sivakumar, Saif Nasser Al Bahri

Abstract:

Diverse approaches and pathways are under development with the determination to develop cellulosic biofuels and other bio-products eventually at commercial scale in “bio-refineries”; however, the key challenge is mainly the high level of complexity in processing the feedstock which is complicated and energy consuming. To overcome the complications in utilizing the naturally occurring lignocellulose biomass, using waste paper as a feedstock for bio-production may solve the problem. Besides being abundant and cheap, bioprocessing of waste paper has evolved in response to the public concern from rising landfill cost from shrinking landfill capacity. Cardboard (CB) is one of the major components of municipal solid waste and one of the most important items to recycle. Although 50-70% of cardboard constitute is known to be cellulose and hemicellulose, the presence of lignin around them cause hydrophobic cross-link which physically obstructs the hydrolysis by rendering it resistant to enzymatic cleavage. Therefore, pretreatment is required to disrupt this resistance and to enhance the exposure of the targeted carbohydrates to the hydrolytic enzymes. Several pretreatment approaches have been explored, and the best ones would be those can influence cellulose conversion rates and hydrolytic enzyme performance with minimal or less cost and downstream processes. One of the promising strategies in this field is the application of surfactants, especially non-ionic surfactants. In this study, triton-X 100 was used as surfactants to treat cardboard prior enzymatic hydrolysis and compare it with acid treatment using 0.1% H2SO4. The effect of the surfactant enhancement was evaluated through its effect on hydrolysis rate in respect to time in addition to evaluating the structural changes and modification by scanning electron microscope (SEM) and X-ray diffraction (XRD) and through compositional analysis. Further work was performed to produce ethanol from CB treated with triton-X 100 via separate hydrolysis and fermentation (SHF) and simultaneous saccharification and fermentation (SSF). The hydrolysis studies have demonstrated enhancement in saccharification by 35%. After 72 h of hydrolysis, a saccharification rate of 98% was achieved from CB enhanced with triton-X 100, while only 89 of saccharification achieved from acid pre-treated CB. At 120 h, the saccharification % exceeded 100 as reducing sugars continued to increase with time. This enhancement was not supported by any significant changes in the cardboard content as the cellulose, hemicellulose and lignin content remained same after treatment, but obvious structural changes were observed through SEM images. The cellulose fibers were clearly exposed with very less debris and deposits compared to cardboard without triton-X 100. The XRD pattern has also revealed the ability of the surfactant in removing calcium carbonate, a filler found in waste paper known to have negative effect on enzymatic hydrolysis. The cellulose crystallinity without surfactant was 73.18% and reduced to 66.68% rendering it more amorphous and susceptible to enzymatic attack. Triton-X 100 has proved to effectively enhance CB hydrolysis and eventually had positive effect on the ethanol yield via SSF. Treating cardboard with only triton-X 100 was a sufficient treatment to enhance the enzymatic hydrolysis and ethanol production.

Keywords: cardboard, enhancement, ethanol, hydrolysis, treatment, Triton-X 100

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1414 Design, Spectroscopic, Structural Characterization, and Biological Studies for New Complexes via Charge Transfer Interaction of Ciprofloxacin Drug With π Acceptors

Authors: Khaled Alshammari

Abstract:

Ciprofloxacin (CIP) is a common antibiotic drug used as a strudy electron donor that interacts with dynamic π -acceptors such as 2,3-dinitrosalsylic acid (HDNS) and Tetracyanoethylene (TCNE) for synthesizing a new model of charge transfer (CT) complexes. The synthesized complexes were identified using diverse analytical methods such as UV–vis spectra, photometric titration measurements, FT-IR, HNMR Spectroscopy, and thermogravimetric analysis techniques (TGA/DTA). The stoichiometries for all the formed complexes were found to be a 1:1 M ratio between the reactants. The characteristic spectroscopic properties such as transition dipole moment (µ), oscillator strength (f), formation constant (KCT), ionization potential (ID), standard free energy (∆G), and energy of interaction (ECT) for the CT-complexes were collected. The developed CT complexes were tested for their toxicity on main organs, antimicrobial activity, antioxidant activity, and biofilm formation.

Keywords: biological, biofilm, toxicity, thermal analysis, charge transfer, spectroscopy

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1413 Fabrication and Characterization of Gelatin Nanofibers Dissolved in Concentrated Acetic Acid

Authors: Kooshina Koosha, Sima Habibi, Azam Talebian

Abstract:

Electrospinning is a simple, versatile and widely accepted technique to produce ultra-fine fibers ranging from nanometer to micron. Recently there has been great interest in developing this technique to produce nanofibers with novel properties and functionalities. The electrospinning field is extremely broad, and consequently there have been many useful reviews discussing various aspects from detailed fiber formation mechanism to the formation of nanofibers and to discussion on a wide range of applications. On the other hand, the focus of this study is quite narrow, highlighting electrospinning parameters. This work will briefly cover the solution and processing parameters (for instance; concentration, solvent type, voltage, flow rate, distance between the collector and the tip of the needle) impacting the morphological characteristics of nanofibers, such as diameter. In this paper, a comprehensive work would be presented on the research of producing nanofibers from natural polymer entitled Gelatin.

Keywords: electrospinning, solution parameters, process parameters, natural fiber

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1412 Effects of Rations with High Amount of Crude Fiber on Rumen Fermentation in Suckler Cows

Authors: H. Scholz, P. Kuehne, G. Heckenberger

Abstract:

Problems during the calving period (December until May) often are results in a high body condition score (BCS) at this time. At the end of the grazing period (frequently after early weaning), however, an increase of BCS can often be observed under German conditions. In the last eight weeks before calving, the body condition should be reduced or at least not increased. Rations with a higher amount of crude fiber can be used (rations with straw or late mowed grass silage). Fermentative digestion of fiber is slow and incomplete; that’s why the fermentative process in the rumen can be reduced over a long feeding time. Viewed in this context, feed intake of suckler cows (8 weeks before calving) in different rations and fermentation in the rumen should be checked by taking rumen fluid. Eight suckler cows (Charolais) were feeding a Total Mixed Ration (TMR) in the last eight weeks before calving and grass silage after calving. By the addition of straw (30 % [TMR1] vs. 60 % [TMR2] of dry matter) was varied the amount of crude fiber in the TMR (grass silage, straw, mineral) before calving. After calving of the cow's grass, silage [GS] was fed ad libitum, and the last measurement of rumen fluid took place on the pasture [PS]. Rumen fluid, plasma, body weight, and backfat thickness were collected. Rumen fluid pH was assessed using an electronic pH meter. Volatile fatty acids (VFA), sedimentation, methylene-blue, and amount of infusorians were measured. From these 4 parameters, an “index of rumen fermentation” [IRF] in the rumen was formed. Fixed effects of treatment (TMR1, TMR2, GS, and PS) and a number of lactations (3-7 lactations) were analyzed by ANOVA using SPSS Version 25.0 (significant by p ≤ 5 %). Rumen fluid pH was significantly influenced by variants (TMR 1 by 6.6; TMR 2 by 6.9; GS by 6.6 and PS by 6.9) but was not affected by other effects. The IRF showed disturbed fermentation in the rumen by feeding the TMR 1+2 with a high amount of crude fiber (Score: > 10.0 points) and a very good environment for fermentation during grazing the pasture (Score: 6.9 points). Furthermore, significant differences were found for VFA, methylene blue, and the number of infusorians. The use of rations with a high amount of crude fiber from weaning to calving may cause deviations from undisturbed fermentation in the rumen and adversely affect the utilization of the feed in the rumen.

Keywords: rumen fermentation, suckler cow, digestibility organic matter, crude fiber

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1411 Designing a Thermal Management System for Lithium Ion Battery Packs in Electric Vehicles

Authors: Ekin Esen, Mohammad Alipour, Riza Kizilel

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Rechargeable lithium-ion batteries have been replacing lead-acid batteries for the last decade due to their outstanding properties such as high energy density, long shelf life, and almost no memory effect. Besides these, being very light compared to lead acid batteries has gained them their dominant place in the portable electronics market, and they are now the leading candidate for electric vehicles (EVs) and hybrid electric vehicles (HEVs). However, their performance strongly depends on temperature, and this causes some inconveniences for their utilization in extreme temperatures. Since weather conditions vary across the globe, this situation limits their utilization for EVs and HEVs and makes a thermal management system obligatory for the battery units. The objective of this study is to understand thermal characteristics of Li-ion battery modules for various operation conditions and design a thermal management system to enhance battery performance in EVs and HEVs. In the first part of our study, we investigated thermal behavior of commercially available pouch type 20Ah LiFePO₄ (LFP) cells under various conditions. Main parameters were chosen as ambient temperature and discharge current rate. Each cell was charged and discharged at temperatures of 0°C, 10°C, 20°C, 30°C, 40°C, and 50°C. The current rate of charging process was 1C while it was 1C, 2C, 3C, 4C, and 5C for discharge process. Temperatures of 7 different points on the cells were measured throughout charging and discharging with N-type thermocouples, and a detailed temperature profile was obtained. In the second part of our study, we connected 4 cells in series by clinching and prepared 4S1P battery modules similar to ones in EVs and HEVs. Three reference points were determined according to the findings of the first part of the study, and a thermocouple is placed on each reference point on the cells composing the 4S1P battery modules. In the end, temperatures of 6 points in the module and 3 points on the top surface were measured and changes in the surface temperatures were recorded for different discharge rates (0.2C, 0.5C, 0.7C, and 1C) at various ambient temperatures (0°C – 50°C). Afterwards, aluminum plates with channels were placed between the cells in the 4S1P battery modules, and temperatures were controlled with airflow. Airflow was provided with a regular compressor, and the effect of flow rate on cell temperature was analyzed. Diameters of the channels were in mm range, and shapes of the channels were determined in order to make the cell temperatures uniform. Results showed that the designed thermal management system could help keeping the cell temperatures in the modules uniform throughout charge and discharge processes. Other than temperature uniformity, the system was also beneficial to keep cell temperature close to the optimum working temperature of Li-ion batteries. It is known that keeping the temperature at an optimum degree and maintaining uniform temperature throughout utilization can help obtaining maximum power from the cells in battery modules for a longer time. Furthermore, it will increase safety by decreasing the risk of thermal runaways. Therefore, the current study is believed to be beneficial for wider use of Li batteries for battery modules of EVs and HEVs globally.

Keywords: lithium ion batteries, thermal management system, electric vehicles, hybrid electric vehicles

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1410 Recovery of Boron as Homogeneous Perborate Particles from Synthetic Wastewater by Integrating Chemical Oxo-Precipitation with Fluidized-Bed Homogeneous Granulation

Authors: Chiung-Chin Huang, Jui-Yen Lin, Yao-Hui Huang

Abstract:

Among current techniques of boron removal from wastewater with high boron concentration, chemical oxo-precipitation (COP) is one of the promising methods due to its milder condition. COP uses H2O2 to transform boric acid to perborates which can easily precipitate with barium ions at room temperature. However, the generation of the waste sludge that requires sludge/water separation and sludge dewatering is troublesome. This work presents an innovative technology which integrates chemical oxo-precipitation (COP) with fluidized-bed homogeneous granulation (FBHG) to reclaim boron as homogeneous perborate particles. By conducting COP in a fluidized-bed reactor, the barium perborate can be granulated to form homogeneous particles (>1.0 mm) with low water content (< 10%). Under the suitable condition, more than 70% of boron can be recovered from 600 ppm of boron solution and the residual boron is lower than 100 ppm.

Keywords: barium, perborate, chemical oxo-precipitation, boron removal, fluidized-bed, granulation

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1409 Acute Phase Proteins as Biomarkers of Urinary Tract Infection (UTI) in Dairy Cattle

Authors: Wael El-Deeb

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The present study aimed to investigate the diagnostic importance of acute phase proteins in urinary tract infection (UTI) in cattle. We describe the clinical, bacteriological and biochemical findings in 99 lactating cows. Blood and urine samples from diseased (n=84) and control healthy cows (n=15) were submitted to laboratory investigations. The urine analysis revealed hematuria and pyuria in UTI group. The isolated bacteria were E.coli (43/84) Corynebacterium spp, (31/84), Proteus spp. (6/84) and Streptococcus spp (4/84). The concentrations of Haptoglobin (Hp), serum amyloid A (SAA), α1-Acid glycoprotein (AGP), fibrinogen (Fb), total protein, albumen, and globulin were higher in cows with UTI when compared to healthy ones. Fifty-one of 84 cows with UTI were successfully treated. The levels of Hp, SAA, AGP, total protein, and globulin were associated with the odds of treatment failure. Conclusively, acute phase proteins could be used as diagnostic and prognostic biomarkers in cows with UTI.

Keywords: cows, urinary, infections, haptoglobin, serum Amyloid A

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1408 Different Methods of Producing Bioemulsifier by Bacillus licheniformis Strains

Authors: Saba Pajuhan, Afshin Farahbakhsh, S. M. M. Dastgheib

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Biosurfactants and bioemulsifiers are a structurally diverse group of surface-active molecules synthesized by microorganisms, they are amphipathic molecules which reduce surface and interfacial tensions and widely used in pharmaceutical, cosmetic, food and petroleum industries. In this paper, several methods of bioemulsifer synthesis and purification by Bacillus licheniformis strains (namely ACO1, PTCC 1595 and ACO4) were investigated. Strains were grown in nutrient broth with different conditions in order to get maximum production of bioemulsifer. The purification of bio emulsifier and the quality evaluation of the product was done by adding sulfuric acid (H₂SO₄) (98%), Ethanol or HCl to the solution followed by centrifuging. To determine the optimal conditions yielding the highest bioemulsifier production, the effect of various carbon and nitrogen sources, temperature, NaCl concentration, pH, O₂ levels, incubation time are indispensable and all of them were highly effective in bioemulsifiers production.

Keywords: biosurfactant, bioemulsifier, purification, surface tension, interfacial tension

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1407 Analysis of Probiotic Properties of Lactobacillus Acidophilus from Commercial Yoghurt

Authors: Anwar Ali Abdulla, Thekra Abdulaali Abed Al-Chaabawi, Anwar Kadhim Al-Saffar, Hussein Kadhim Al-Saffar

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Lactic acid bacteria are very significant to human health due to the production of some antimicrobial substances and ability to inhibit pathogenic bacteria. Furthermore, the bacteria are also used as starter culture in the production of various foods. The present study was focused on isolation and characterization of Lactobacillus acidophilus from yogurt and to demonstrate some of probiotic properties of these isolates. All isolates were phenotypically characterized including studying, biochemical, effect of sodium chloride and pH during growth, carbohydrates test and characterizing the antimicrobial activity of Lactobacillus acidophilus against pathogens. The present study demonstrates that Lactobacillus acidophilus produced a bacteriocin- like inhibitory substance with a broad spectrum of antimicrobial activity directed against pathogenic indicator organism suggesting its protective value against enteric pathogens.

Keywords: lactobacillus acidophilus, bacteriocin, antimicrobial activity, probiotic

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1406 Functionalization of Sanitary Pads with Probiotic Paste

Authors: O. Sauperl, L. Fras Zemljic

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The textile industry is gaining increasing importance in the field of medical materials. Therefore, presented research is focused on textile materials for external (out-of-body) use. Such materials could be various hygienic textile products (diapers, tampons, sanitary napkins, incontinence products, etc.), protective textiles and various hospital linens (surgical covers, masks, gowns, cloths, bed linens, etc.) wound pillows, bandages, orthopedic socks, etc. Function of tampons and sanitary napkins is not only to provide protection during the menstrual cycle, but their function can be also to take care of physiological or pathological vaginal discharge. In general, women's intimate areas are against infection protected by a low pH value of the vaginal flora. High pH inhibits the development of harmful microorganisms, as it is difficult to be reproduced in an acidic environment. The normal vaginal flora in healthy women is highly colonized by lactobacilli. The lactic acid produced by these organisms maintains the constant acidity of the vagina. If the balance of natural protection breaks, infections can occur. In the market, there exist probiotic tampons as a medical product supplying the vagina with beneficial probiotic lactobacilli. But, many users have concerns about the use of tampons due to the possible dry-out of the vagina as well as the possible toxic shock syndrome, which is the reason that they use mainly sanitary napkins during the menstrual cycle. Functionalization of sanitary napkins with probiotics is, therefore, interesting in regard to maintain a healthy vaginal flora and to offer to users added value of the sanitary napkins in the sense of health- and environmentally-friendly products. For this reason, the presented research is oriented in functionalization of the sanitary napkins with the probiotic paste in order to activate the lactic acid bacteria presented in the core of the functionalized sanitary napkin at the time of the contact with the menstrual fluid. In this way, lactobacilli could penetrate into vagina and by maintaining healthy vaginal flora to reduce the risk of vaginal disorders. In regard to the targeted research problem, the influence of probiotic paste applied onto cotton hygienic napkins on selected properties was studied. The aim of the research was to determine whether the sanitary napkins with the applied probiotic paste may assure suitable vaginal pH to maintain a healthy vaginal flora during the use of this product. Together with this, sorption properties of probiotic functionalized sanitary napkins were evaluated and compared to the untreated one. The research itself was carried out on the basis of tracking and controlling the input parameters, currently defined by Slovenian producer (Tosama d.o.o.) as the most important. Successful functionalization of sanitary pads with the probiotic paste was confirmed by ATR-FTIR spectroscopy. Results of the methods used within the presented research show that the absorption of the pads treated with probiotic paste deteriorates compared to non-treated ones. The coating shows a 6-month stability. Functionalization of sanitary pads with probiotic paste is believed to have a commercial potential for lowering the probability of infection during the menstrual cycle.

Keywords: functionalization, probiotic paste, sanitary pads, textile materials

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1405 Electrocoagulation of Ni(OH)2/NiOOH for the Removal of Boron Using Nickel Foam as Sacrificial Anode

Authors: Yu-Jen Shih, Yao-Hui Hunag

Abstract:

Electrocoagulation (EC) using metallic nickel foam as anode and cathode for the removal of boron from solution was studied. The electrolytic parameters included pH, current density, and initial boron concentration for optimizing the EC process. Experimental results showed that removal efficiency was increased by elevating pH from 4.0 to 8.0, and then decreased at higher pH. The electrolytic efficacy was not affected by current density. In respect of energy consumption, 1.25 mA/cm2 of current density was acceptable for an effective EC of boron, while increasing boric acid from 10 to 100 ppm-B did not impair removal efficiency too much. Cyclic voltammetry indicated that the oxide film, Ni(OH)2 and NiOOH, at specific overpotentials would result in less weight loss of anode than that predicted by the Faraday’s law. The optimal conditions under which 99.2% of boron was removed and less than 1 ppm-B remained in the electrolyte would be pH 8, four pairs of electrodes, and 1.25 mA/cm2 in 120 min as treating wastewaters containing 10 ppm-B. XRD and SEM characterization suggested that the granular crystallites of hydroxide precipitates was composed of theophrastite.

Keywords: borohydrides, hydrogen generation, NiOOH, electrocoagulation, cyclic voltammetry, boron removal

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1404 Enhancing the Dyeability and Performance of Recycled Polyethylene Terephthalate with Hyperbranched Polyester

Authors: Haroon Abdelrahman Mohamed Saeed, Hongjun Yang

Abstract:

This study aims to examine the impact of hyperbranched polyester (AA-Ph) on the dyeability and color fastness of recycled poly (ethylene terephthalate) (RPET) fabric. AA-Ph was synthesized through single-step melt polycondensation of adipic acid (AA) and phloroglucinol (Ph) and then incorporated into RPET before spinning. The addition of AA-Ph significantly improves the dye uptake of recycled PET when dyed with disperse dye blue 56 due to the introduction of polar groups and aromatic rings. The blends RPET-3 and RPET-5 show strong abrasion resistance, dyeability, and washing fastness. Furthermore, these blends exhibit high moisture absorbance owing to the polar groups and aromatic structures, as demonstrated by exhaustion tests, which enhance perspiration absorption for added comfort in apparel. Overall, RPET-3 and RPET-5 blends are well-suited for various textile applications, especially in garment manufacturing.

Keywords: recycled poly (ethylene terephthalate), hyperbranched polyester, dyeability, dye blue

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1403 Utilization Of Guar Gum As Functional Fat Replacer In Goshtaba, A Traditional Indian Meat Product

Authors: Sajad A. Rather, F. A. Masoodi, Rehana Akhter, S. M. Wani, Adil Gani

Abstract:

Modern trend towards convenience foods has resulted in increased production and consumption of restructured meat products and are of great importance to the meat industry. In meat products fat plays an important role in cooking properties, texture & sensory scores, however, high fat contents in particular animal fats provide high amounts of saturated fatty acids and cholesterol and are associated with several types of non communicable diseases such as obesity, hypertension and coronary heart diseases. Thus, fat reduction has generally been seen as an important strategy to produce healthier meat products. This study examined the effects of reducing fat level from 20% to 10% and substituting mutton back fat with guar gum (0.5%, 1% & 1.5%) on cooking properties, proximate composition, lipid and protein oxidation, texture, microstructure and sensory characteristics of goshtaba- a traditional meat product of J & K, India were investigated and compared with high fat counterparts. Reduced- fat goshtaba samples containing guar gum had significantly (p ≤ 0.05) higher yield, less shrinkage, more moisture retention and more protein content than the control sample. TBARs and protein oxidation (carbonyl content) values of the control was significantly (p ≤ 0.05) higher than reduced fat goshtaba samples and showed a positive correlation between lipid and protein oxidation. Hardness, gumminess & chewiness of the control (20%) were significantly higher than reduced fat goshtaba samples. Microstructural differences were significant (p ≤ 0.05) between control and treated samples due to an increased moisture content in the reduced fat samples. Sensory evaluation showed significant (p ≤ 0.05) reduction in texture, flavour and overall acceptability scores of treatment products; however the scores for 0.5% and 1% treated samples were in the range of acceptability. Guar gum may also be used as a source of soluble dietary fibre in food products and a number of clinical studies have shown a reduction in postprandial glycemia and insulinemia on consumption of guar gum, with the mechanism being attributed to an increased transit time in the stomach and small intestine, which may have been due to the viscosity of the meal hindering the access of glucose to the epithelium.

Keywords: goshtaba, guar gum, traditional, fat reduction, acceptability

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1402 Poly(N-Vinylcaprolactam) Based Degradable Microgels for Controlled Drug Delivery

Authors: G. Agrawal, R. Agrawal, A. Pich

Abstract:

The pH and temperature responsive biodegradable poly(N-vinylcaprolactam) (PVCL) based microgels functionalized with itaconic acid (IA) units are prepared via precipitation polymerization for drug delivery applications. Volume phase transition temperature (VPTT) of the obtained microgels is influenced by both IA content and pH of the surrounding medium. The developed microgels can be degraded under acidic conditions due to the presence of hydrazone based crosslinking points inside the microgel network. The microgel particles are able to effectively encapsulate doxorubicin (DOX) drug and exhibit low drug leakage under physiological conditions. At low pH, rapid DOX release is observed due to the changes in electrostatic interactions along with the degradation of particles. The results of the cytotoxicity assay further display that the DOX-loaded microgel exhibit effective antitumor activity against HeLa cells demonstrating their great potential as drug delivery carriers for cancer therapy.

Keywords: degradable, drug delivery, hydrazone linkages, microgels, responsive

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1401 Activation of Caspase 3 by Terpenoids and Flavonoids in Cancer Cell Lines

Authors: Nusrat Masood, Vijaya Dubey, Suaib Luqman

Abstract:

Caspase 3, a member of cysteine-aspartic acid protease family, is an imperative indicator for cell death particularly when substantiating apoptosis. Thus, caspase 3 is an interesting target for the discovery and development of anticancer agent. We adopted a four level assessment of both terpenoids and flavonoids and thus experimentally performed the enzymatic assay in cell free system as well as in cancer cell line which was validated through real time expression and molecular interaction studies. A significant difference was observed with both the class of natural products indicating terpenoids as better activators of caspase 3 compared to flavonoids both in the cell free system as well as in cell lines. The expression analysis, activation constant and binding energy also correlate well with the enzyme activity. Overall, terpenoids had an unswerving effect on caspase 3 in all the tested system while flavonoids indirectly affect enzyme activity.

Keywords: Caspase 3, terpenoids, flavonoids, activation constant, binding energy

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1400 Recovery of Zn from Different Çinkur Leach Residues by Acidic Leaching

Authors: Mehmet Ali Topçu, Aydın Ruşen

Abstract:

Çinkur is the only plant in Turkey that produces zinc from primary ore containing zinc carbonate from its establishment until 1997. After this year, zinc concentrate coming from Iran was used in this plant. Therefore, there are two different leach residues namely Turkish leach residue (TLR) and Iranian leach residue (ILR), in Çinkur stock piles. This paper describes zinc recovery by sulphuric acid (H2SO4) treatment for each leach residue and includes comparison of blended of TLR and ILR. Before leach experiments; chemical, mineralogical and thermal analysis of three different leach residues was carried out by using atomic absorption spectrometry (AAS), X-Ray diffraction (XRD) and differential thermal analysis (DTA), respectively. Leaching experiments were conducted at optimum conditions; 100 oC, 150 g/L H2SO4 and 2 hours. In the experiments, stirring rate was kept constant at 600 r/min which ensures complete mixing in leaching solution. Results show that zinc recovery for Iranian LR was higher than Turkish LR due to having different chemical composition from each other.

Keywords: hydrometallurgy, leaching, metal extraction, metal recovery

Procedia PDF Downloads 354
1399 Corrosion Monitoring of Weathering Steel in a Simulated Coastal-Industrial Environment

Authors: Thee Chowwanonthapunya, Junhua Dong, Wei Ke

Abstract:

The atmospheres in many cities along the coastal lines in the world have been rapidly changed to coastal-industrial atmosphere. Hence, it is vital to investigate the corrosion behavior of steel exposed to this kind of environment. In this present study, Electrochemical Impedance Spectrography (EIS) and film thickness measurements were applied to monitor the corrosion behavior of weathering steel covered with a thin layer of the electrolyte in a wet-dry cyclic condition, simulating a coastal-industrial environment at 25 oC and 60 % RH. The results indicate that in all cycles, the corrosion rate increases during the drying process due to an increase in anion concentration and an acceleration of oxygen diffusion enhanced by the effect of the thinning out of the electrolyte. During the wet-dry cyclic corrosion test, the long-term corrosion behavior of this steel depends on the periods of exposure. Corrosion process is first accelerated and then decelerated. The decelerating corrosion process is contributed to the formation of the protective rust, favored by the wet-dry cycle and the acid regeneration process during the rusting process.

Keywords: atmospheric corrosion, EIS, low alloy, rust

Procedia PDF Downloads 449
1398 Optimization of Synergism Extraction of Toxic Metals (Lead, Copper) from Chlorides Solutions with Mixture of Cationic and Solvating Extractants

Authors: F. Hassaine-Sadi, S. Chelouaou

Abstract:

In recent years, environmental contamination by toxic metals such as Pb, Cu, Ni, Zn ... has become a worldwide crucial problem, particularly in some areas where the population depends on groundwater for drinking daily consumption. Thus, the sources of metal ions come from the metal manufacturing industry, fertilizers, batteries, paints, pigments and so on. Solvent extraction of metal ions has given an important role in the development of metal purification processes such as the synergistic extraction of some divalent cations metals ( M²⁺), the ions metals from various sources. This work consists of a water purification technique that involves the lead and copper systems: Pb²⁺, H₃O+, Cl⁻ and Cu²⁺, H₃O⁺, Cl⁻ for diluted solutions by a mixture of tri-n-octylphosphine oxide (TOPO) or Tri-n-butylphosphate(TBP) and di (2-ethyl hexyl) phosphoric acid (HDEHP) dissolved in kerosene. The study of the fundamental parameters influencing the extraction synergism: cation exchange/extraction solvent have been examined.

Keywords: synergistic extraction, lead, copper, environment

Procedia PDF Downloads 445
1397 Effect of Environmental Stress Factors on the Degradation of Display Glass

Authors: Jinyoung Choi, Hyun-A Kim, Sunmook Lee

Abstract:

The effects of environmental stress factors such as storage conditions on the deterioration phenomenon and the characteristic of the display glass were studied. In order to investigate the effect of chemical stress on the glass during the period of storage, the respective components of commercial glass were first identified by XRF (X-ray fluorescence). The glass was exposed in the acid, alkali, neutral environment for about one month. Thin film formed on the glass surface was analyzed by XRD (X-ray diffraction) and FT-IR (Fourier transform infrared). The degree of corrosion and the rate of deterioration of each sample were confirmed by measuring the concentrations of silicon, calcium and chromium with ICP-OES (Inductively coupled plasma-optical emission spectrometry). The optical properties of the glass surface were confirmed by SEM (Scanning electron microscope) before and after the treatment. Acknowledgement—The authors gratefully acknowledge the financial support from the Ministry of Trade, Industry and Energy (Grant Number: 10076817)

Keywords: corrosion, degradation test, display glass, environmental stress factor

Procedia PDF Downloads 459
1396 Ruta graveolens Fingerprints Obtained with Reversed-Phase Gradient Thin-Layer Chromatography with Controlled Solvent Velocity

Authors: Adrian Szczyrba, Aneta Halka-Grysinska, Tomasz Baj, Tadeusz H. Dzido

Abstract:

Since prehistory, plants were constituted as an essential source of biologically active substances in folk medicine. One of the examples of medicinal plants is Ruta graveolens L. For a long time, Ruta g. herb has been famous for its spasmolytic, diuretic, or anti-inflammatory therapeutic effects. The wide spectrum of secondary metabolites produced by Ruta g. includes flavonoids (eg. rutin, quercetin), coumarins (eg. bergapten, umbelliferone) phenolic acids (eg. rosmarinic acid, chlorogenic acid), and limonoids. Unfortunately, the presence of produced substances is highly dependent on environmental factors like temperature, humidity, or soil acidity; therefore standardization is necessary. There were many attempts of characterization of various phytochemical groups (eg. coumarins) of Ruta graveolens using the normal – phase thin-layer chromatography (TLC). However, due to the so-called general elution problem, usually, some components remained unseparated near the start or finish line. Therefore Ruta graveolens is a very good model plant. Methanol and petroleum ether extract from its aerial parts were used to demonstrate the capabilities of the new device for gradient thin-layer chromatogram development. The development of gradient thin-layer chromatograms in the reversed-phase system in conventional horizontal chambers can be disrupted by problems associated with an excessive flux of the mobile phase to the surface of the adsorbent layer. This phenomenon is most likely caused by significant differences between the surface tension of the subsequent fractions of the mobile phase. An excessive flux of the mobile phase onto the surface of the adsorbent layer distorts the flow of the mobile phase. The described effect produces unreliable, and unrepeatable results, causing blurring and deformation of the substance zones. In the prototype device, the mobile phase solution is delivered onto the surface of the adsorbent layer with controlled velocity (by moving pipette driven by 3D machine). The delivery of the solvent to the adsorbent layer is equal to or lower than that of conventional development. Therefore chromatograms can be developed with optimal linear mobile phase velocity. Furthermore, under such conditions, there is no excess of eluent solution on the surface of the adsorbent layer so the higher performance of the chromatographic system can be obtained. Directly feeding the adsorbent layer with eluent also enables to perform convenient continuous gradient elution practically without the so-called gradient delay. In the study, unique fingerprints of methanol and petroleum ether extracts of Ruta graveolens aerial parts were obtained with stepwise gradient reversed-phase thin-layer chromatography. Obtained fingerprints under different chromatographic conditions will be compared. The advantages and disadvantages of the proposed approach to chromatogram development with controlled solvent velocity will be discussed.

Keywords: fingerprints, gradient thin-layer chromatography, reversed-phase TLC, Ruta graveolens

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1395 Quercetin Nanoparticles and Their Hypoglycemic Effect in a CD1 Mouse Model with Type 2 Diabetes Induced by Streptozotocin and a High-Fat and High-Sugar Diet

Authors: Adriana Garcia-Gurrola, Carlos Adrian Peña Natividad, Ana Laura Martinez Martinez, Alberto Abraham Escobar Puentes, Estefania Ochoa Ruiz, Aracely Serrano Medina, Abraham Wall Medrano, Simon Yobanny Reyes Lopez

Abstract:

Type 2 diabetes mellitus (T2DM) is a metabolic disease characterized by elevated blood glucose levels. Quercetin is a natural flavonoid with a hypoglycemic effect, but reported data are inconsistent due mainly to the structural instability and low solubility of quercetin. Nanoencapsulation is a distinct strategy to overcome the intrinsic limitations of quercetin. Therefore, this work aims to develop a quercetin nano-formulation based on biopolymeric starch nanoparticles to enhance the release and hypoglycemic effect of quercetin in T2DM induced mice model. Starch-quercetin nanoparticles were synthesized using high-intensity ultrasonication, and structural and colloidal properties were determined by FTIR and DLS. For in vivo studies, CD1 male mice (n=25) were divided into five groups (n=5). T2DM was induced using a high-fat and high-sugar diet for 32 weeks and streptozotocin injection. Group 1 consisted of healthy mice fed with a normal diet and water ad libitum; Group 2 were diabetic mice treated with saline solution; Group 3 were diabetic mice treated with glibenclamide; Group 4 were diabetic mice treated with empty nanoparticles; and Group 5 was diabetic mice treated with quercetin nanoparticles. Quercetin nanoparticles had a hydrodynamic size of 232 ± 88.45 nm, a PDI of 0.310 ± 0.04 and a zeta potential of -4 ± 0.85 mV. The encapsulation efficiency of nanoparticles was 58 ± 3.33 %. No significant differences (p = > 0.05) were observed in biochemical parameters (lipids, insulin, and peptide C). Groups 3 and 5 showed a similar hypoglycemic effect, but quercetin nanoparticles showed a longer-lasting effect. Histopathological studies reveal that T2DM mice groups showed degenerated and fatty liver tissue; however, a treated group with quercetin nanoparticles showed liver tissue like that of the healthy mice group. These results demonstrate that quercetin nano-formulations based on starch nanoparticles are effective alternatives with hypoglycemic effects.

Keywords: quercetin, diabetes mellitus tipo 2, in vivo study, nanoparticles

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1394 Chitosan Functionalized Fe3O4@Au Core-Shell Nanomaterials for Targeted Drug Delivery

Authors: S. S. Pati, L. Herojit Singh, A. C. Oliveira, V. K. Garg

Abstract:

Chitosan functionalized Fe3O4-Au core shell nanoparticles have been prepared using a two step wet chemical approach using NaBH4 as reducing agent for formation of Au inethylene glycol. X-ray diffraction studies shows individual phases of Fe3O4 and Au in the as prepared samples with crystallite size of 5.9 and 11.4 nm respectively. The functionalization of the core-shell nanostructure with Chitosan has been confirmed using Fourier transform infrared spectroscopy along with signatures of octahedral and tetrahedral sites of Fe3O4 below 600cm-1. Mössbauer spectroscopy shows decrease in particle-particle interaction in presence of Au shell (72% sextet) than pure oleic coated Fe3O4 nanoparticles (88% sextet) at room temperature. At 80K, oleic acid coated Fe3O4 shows only sextets whereas the Chitosan functionalized Fe3O4 and Chitosan functionalized Fe3O4@Au core shell show presence of 5 and 11% doublet, respectively.

Keywords: core shell, drug delivery, gold nanoparticles, magnetic nanoparticles

Procedia PDF Downloads 375
1393 Lipid Emulsion versus DigiFab in a Rat Model of Acute Digoxin Toxicity

Authors: Cansu Arslan Turan, Tuba Cimilli Ozturk, Ebru Unal Akoglu, Kemal Aygun, Ecem Deniz Kırkpantur, Ozge Ecmel Onur

Abstract:

Although the mechanism of action is not well known, Intravenous Lipid Emulsion (ILE) has been shown to be effective in the treatment of lipophilic drug intoxications. It is thought that ILE probably separate the lipophilic drugs from target tissue by creating a lipid-rich compartment in the plasma. The second theory is that ILE provides energy to myocardium with high dose free fatty acids activating the voltage gated calcium channels in the myocytes. In this study, the effects of ILE treatment on digoxin overdose which are frequently observed in emergency departments was searched in an animal model in terms of cardiac side effects and survival. The study was carried out at Yeditepe University, Faculty of Medicine-Experimental Animals Research Center Labs in December 2015. 40 Sprague-Dawley rats weighing 300-400 g were divided into 5 groups randomly. As the pre-treatment, the first group received saline, the second group received lipid, the third group received DigiFab, and the fourth group received DigiFab and lipid. Following that, digoxin was infused to all groups until death except the control group. First arrhythmia and cardiac arrest occurrence times were recorded. As no medication causing arrhythmia was infused, Group 5 was excluded from the statistical analysis performed for the comparisons of first arrhythmia and death time. According to the results although there was no significant difference in the statistical analysis comparing the four groups, as the rats, only exposed to digoxin intoxication were compared with the rats pre-treated with ILE in terms of first arrhythmia time and cardiac arrest occurrence times, significant difference was observed between the groups. According to our results, using DigiFab treatment, intralipid treatment, intralipid and DigiFab treatment for the rats exposed to digoxin intoxication makes no significant difference in terms of the first arrhythmia and death occurrence time. However, it is not possible to say that at the doses we use in the study, ILE treatment might be successful at least as a known antidote. The fact that the statistical significance between the two groups is not observed in the inter-comparisons of all the groups, the study should be repeated in the larger groups.

Keywords: arrhytmia, cardiac arrest, DigiFab, digoxin intoxication

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1392 Mechanical Structural and Optical Properties of Lu₂SiO₅ Scintillator-Polymer Composite Films

Authors: M. S. E. Hamroun, K. Bachari, A. Berrayah, L. Mechernene, L. Guerbous

Abstract:

Composite films containing homogeneously dispersed scintillation nano-particles of Lu₂SiO₅:Ce³⁺, in optically transparent polymer matrix, have been prepared and characterized through X-ray diffraction, differential scanning calorimetric (DSC), thermogravimetric analysis (ATG), dynamic mechanical analysis (DMA), electron scanning microscopy morphology (SEM) and photoluminescence (PL). Lu₂SiO₅:Ce³⁺ scintillator powder was successfully synthesized via Sol-Gel method. This study is realized with different mass ratios of nano-particles embedded in polystyrene and polylactic acid polymer matrix (5, 10, 15, 20%) to see the influence of nano-particles on the mechanical, structural and optical properties of films. The composites have been prepared with 400 µm thickness. It has found that the structural proprieties change with mass ratio on each sample. PL photoluminescence shows the characteristic Lu₂SiO₅:Ce³⁺ emission in the blue region and intensity varied for each film.

Keywords: nano-particles, sol gel, photoluminescence, Ce³⁺, scintillator, polystyrene

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1391 Mechanistic Analysis of an L-2-Haloacid Dehalogenase (DehL) from Rhizobium Sp. RC1: Computational Approach

Authors: Aliyu Adamu, Fahrul Huyop, Roswanira Abdul Wahab, Mohd Shahir Shamsir

Abstract:

Halogenated organic compounds occur in huge amount in biosphere. This is attributable to the diverse use of halogen-based compounds in the synthesis of various industrially important products. Halogenated compound is toxic and may persist in the environment, thereby causing serious health and environmental pollution problems. L-2-haloacid dehalogenases (EC 3.8.1.2) catalyse the specific cleavage of carbon-halogen bond in L-isomers of halogenated compounds, which consequently reverse the effects of environmental halogen-associated pollution. To enhance the efficiency and utility of these enzymes, this study investigates the catalytic amino acid residues and the molecular functional mechanism of DehL, by classical molecular dynamic simulations, MM-PBSA and ab initio fragments molecular orbital (FMO) calculations. The results of the study will serve as the basis for the molecular engineering of the enzyme.

Keywords: DehL, Functional mechanism, Catalytic residues, L-2-haloacid dehalogenase

Procedia PDF Downloads 364