Search results for: O-ring membrane module
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1775

Search results for: O-ring membrane module

455 Alleviation of Salt Stress Effects on Solanum lycopersicum (L.) Plants Grown in a Saline Soil by Foliar Spray with Salicylic Acid

Authors: Saad Howladar

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Salinity stress is one of the major abiotic stresses, restricting plant growth and crop productivity in different world regions, especially in arid and semi-arid regions, including Saudi Arabia. The tomato plant is proven to be moderately sensitive to salt stress. Therefore, two field experiments were conducted using tomato plants (Hybrid 6130) to evaluate the effect of four concentrations of salicylic acid (SA; 0, 20, 40, and 60 µM) applied as foliar spraying in improving plant tolerance to saline soil conditions. Tomato plant growth, yield, osmoprotectants, chloeophyll fluorescence, and ionic contents were determined. The results of this study displayed that growth and yield components and physiological attributes of water-sprayed plants (the control) grown under saline soil conditions were negatively impacted. However, under the adverse conditions of salinity, SA-treated plants had enhanced growth and yield components of tomato plants compared to the control. Free proline, soluble sugars, chlorophyll fluorescence, relative water content, membrane stability index, and nutrients contents (e.g., N, P, K⁺, and Ca²⁺) were also improved significantly, while Na⁺ content was significantly reduced in SA-applied tomato plants. SA at 40 µM was the best treatment, which could be recommended to use for salt-stressed tomato plants to enable them to tolerate the adverse conditions of saline soils.

Keywords: tomatoes, salt stress, chlorophyll fluorescence, dehydration tolerance, osmoprotectants

Procedia PDF Downloads 107
454 Protective Effect of L-Carnitine against Gentamicin-Induced Nephrotoxicity in Rats

Authors: Mohamed F. Ahmed, Mabruka S. Elashheb, Fatma M. Ben Rabha

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This study aimed to determine the possible protective effects of L‐carnitine against gentamicin‐induced nephrotoxicity. Forty male albino rats were divided into 4 groups (10 rats each); Group 1: normal control, group 2: induced nephrotoxicity (gentamicin 50 mg/kg/day S.C; 8 days) , group 3: treated with L‐carnitine (40 mg/kg/d SC for 12 days) and group 4: treated with L‐carnitine 4 days before and for 8 days in concomitant with gentamicin. Gentamicin‐induced nephrotoxicity (group 2): caused significant increase in serum urea, creatinine, urinary N‐acetyl‐B‐D‐glucosaminidase (NAG), gamma glutamyl transpeptidase (GGT), urinary total protein and kidney tissue malondialdehyde (MDA) with significant decrease in serum superoxide dismutase (SOD), serum catalase and creatinine clearance and marked tubular necrosis in the proximal convoluted tubules with interruption in the basement membrane around the necrotic tubule compared to the normal control group. L‐carnitine 4 days before and for 8 days in concomitant with gentamicin (group 4) offered marked decrease in serum urea, serum creatinine, urinary NAG, urinary GGT, urinary proteins and kidney tissue MDA, with marked increase in serum SOD, serum catalase and creatinine clearance with marked improvement in the tubular damage compared to gentamicin‐induced nephrotoxicity group. L‐carnitine administered for 12 days produced no change in the above-mentioned parameters as compared to the normal control group. In conclusion: L‐carnitine could reduce most of the biochemical parameters and also improve the histopathological features of the kidney associated with gentamicin-induced nephrotoxicity.

Keywords: gentamicin, nephrotoxicity, L‐carnitine, kidney disease

Procedia PDF Downloads 354
453 Comparision of Neospora caninum Experimental Infection in Pigeons and Chickens Embryonated Eggs

Authors: S. Bahrami, A. Rezaie, Z. Boroumand, S. Ghavami

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Neospora caninum is protozoan parasite which can cause a serious disease in dogs and cattle. It has been shown that birds may be a permissive intermediate host for N. caninum since parasite DNA has been detected in tissues from birds. It is showed that embryonated chicken egg can be used as an animal model for experimental infection. The aim of present study was to compare experimental infection of Neospora in chicken and pigeons embryonated eggs. An infection with N. caninum Nc1 isolate was conducted in chicken and pigeons embryonated eggs to evaluate LD50. After calculation of LD50, 2LD50 of tachyzoites were injected to eggs. Macroscopic changes of each embryo were noticed and to investigate the parasite distribution in tissues immunohistochemistry (IHC) and molecular methods were used. In the present study, histopathological changes were considered and sections to those used for histopathological examination including heart, liver, brain and chorioallantoic (CA) membrane were subjected to IHC, too. For PCR procedure, primer pair Np21/Np6 was used for amplification of the Nc5 gene. Pigeon's embryo showed more macroscopic changes than chicken embryo. A hemorrhage of the CA was the main grass lesion. All the infected tissues had histopathological changes. Microscopic examination of tissues revealed acute neosporosis due to hemorrhage, necrosis and infiltration of mononuclear inflammatory cells. Based on IHC and molecular results, the parasite aggregation in the heart was more predominant than in the other tissues. These results reinforce that there is genetic susceptibility to N. caninum in pigeons embryonated eggs like chickens embryonated eggs and provide new insights to research an inexpensive and available animal model for N. caninum.

Keywords: immunohistochemistry, Neospora caninum, PCR, pigeon embryonated egg

Procedia PDF Downloads 341
452 Computational Fluid Dynamics Modelling of the Improved Airflow on a Ballistic Grille Using a Porous Medium Approach

Authors: Mapula Mothomogolo, Anria Clarke

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Ballistic grilles are adopted on military vehicles to mitigate the vulnerability of the radiator. The design of ballistic grilles needs to address conflicting requirements: shielding the surface area of the radiator from incoming projectile threats yet providing sufficient airflow through the radiator to yield adequate heat rejection. These conflicting requirements result in a unique and challenging design problem. In this paper, the airflow through a ballistic grille using a computational modelling approach is investigated. A comparative study was conducted between a standard grille and a ballistic grille of a military vehicle. The results were used as a benchmark study for optimizing the ballistic grille with pressure drop selected as the parameter for optimization. The grilles were modelled as a porous medium to account for the pressure drop in the porous region. The effects of the porous zone were accounted for in the source term of the momentum Navier Stokes equations. The source term defines the pressure drop in the porous region as a function of the velocity. A pressure drop curve approach was used to determine the Darcy coefficient and inertial resistance coefficients of the source terms. The empirically defined coefficients were used as simulation input for a more accurate pressure drop prediction in the porous region. Additionally, the ballistic grille was optimized using an adjoint solver (shape optimization module in Ansys Fluent) to reduce the pressure drop through the ballistic grille by 30%. Based on the simulation results, the optimized ballistic grille geometry needs to be experimentally tested to validate the numerical simulation data.

Keywords: ballistic grille, darcy coefficient, optimization, porous medium

Procedia PDF Downloads 30
451 Understanding the Mechanisms of Salmonella typhimurium Resistance to Cannabidiol

Authors: Iddrisu Ibrahim, Joseph Atia Ayariga, Junhuan Xu, Daniel Abugri, Boakai Robertson, Olufemi S. Ajayi

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The emergence of multidrug resistance poses a huge risk to public health globally. Yet these recalcitrant pathogens continue to rise in incidence rate, with resistance rates significantly outpacing the speed of antibiotic development. This, therefore, presents an aura of related health issues such as untreatable nosocomial infections arising from organ transplants and surgeries, as well as community-acquired infections that are related to people with compromised immunity, e.g., diabetic and HIV patients, etc. There is a global effort to fight multidrug-resistant pathogens spearheaded by the World Health Organization, thus calling for research into novel antimicrobial agents to fight multiple drug resistance. Previously, our laboratory demonstrated that Cannabidiol (CBD) was an effective antimicrobial against Salmonella typhimurium (S. typhimurium). However, we observed resistance development over time. To understand the mechanisms S. typhimurium uses to develop resistance to Cannabidiol (CBD), we studied the abundance of bacteria lipopolysaccharide (LPS) and membrane sterols of both susceptible and resistant S. typhimurium. Using real-time quantitative polymerase chain reaction (RT-qPCR), we also analyzed the expression of selected genes known for aiding resistance development in S. typhimurium. We discovered that there was a significantly higher expression of blaTEM, fimA, fimZ, and integrons in the CBD-resistant bacteria, and these were also accompanied by a shift in abundance in cell surface molecules such as lipopolysaccharide (LPS) and sterols.

Keywords: antimicrobials, resistance, cannabidiol, gram-negative bacteria, integrons, blaTEM, Fim, LPS, ergosterols

Procedia PDF Downloads 99
450 Module Based Review over Current Regenerative Braking Landing Gear

Authors: Madikeri Rohit

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As energy efficiency is the key concern in many aircraft manufacturing companies regenerative braking is a technique using which energy lost due to friction while braking can be regained. In the operation of an aircraft, significant energy is lost during deceleration or braking which occurs during its landing phase. This problem can be overcome using Regenerative Breaking System (RBS) in landing gear. The major problem faced is regarding the batteries and the overall efficiency gained in competence with the added weight. As the amount of energy required to store is huge we need batteries with high capacity for storage. Another obstacle by using high capacity batteries is the added weight which undermines the efficiency obtained using RBS. An approach to this problem is to either use the obtained energy immediately without storage or to store in other forms such as mechanical, pneumatic and hydraulic. Problem faced with mechanical systems is the weight of the flywheel needed to obtain required efficiency. Pneumatic and hydraulic systems are a better option at present. Using hydraulic systems for storing energy is efficient as it integrates into the overall hydraulic system present in the aircraft. Another obstacle is faced with the redundancy of this system. Conventional braking must be used along with RBS in order to provide redundancy. Major benefits obtained using RBS is with the help of the energy obtained during landing which can be used of engine less taxing. This reduces fuel consumption as well as noise and air pollution. Another added benefit of using RBS is to provide electrical supply to lighting systems, cabin pressurization system and can be used for emergency power supply in case of electric failure. This paper discusses about using RBS in landing gear, problems, prospects and new techniques being pursued to improve RBS.

Keywords: regenerative braking, types of energy conversion, landing gear, energy storage

Procedia PDF Downloads 258
449 Numerical Study on Response of Polymer Electrolyte Fuel Cell (PEFCs) with Defects under Different Load Conditions

Authors: Muhammad Faizan Chinannai, Jaeseung Lee, Mohamed Hassan Gundu, Hyunchul Ju

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Fuel cell is known to be an effective renewable energy resource which is commercializing in the present era. It is really important to know about the improvement in performance even when the system faces some defects. This study was carried out to analyze the performance of the Polymer electrolyte fuel cell (PEFCs) under different operating conditions such as current density, relative humidity and Pt loadings considering defects with load changes. The purpose of this study is to analyze the response of the fuel cell system with defects in Balance of Plants (BOPs) and catalyst layer (CL) degradation by maintaining the coolant flow rate as such to preserve the cell temperature at the required level. Multi-Scale Simulation of 3D two-phase PEFC model with coolant was carried out under different load conditions. For detailed analysis and performance comparison, extensive contours of temperature, current density, water content, and relative humidity are provided. The simulation results of the different cases are compared with the reference data. Hence the response of the fuel cell stack with defects in BOP and CL degradations can be analyzed by the temperature difference between the coolant outlet and membrane electrode assembly. The results showed that the Failure of the humidifier increases High-Frequency Resistance (HFR), air flow defects and CL degradation results in the non-uniformity of current density distribution and high cathode activation overpotential, respectively.

Keywords: PEM fuel cell, fuel cell modeling, performance analysis, BOP components, current density distribution, degradation

Procedia PDF Downloads 211
448 Effect of Particle Size and Concentration of Pomegranate (Punica granatum l.) Peel Powder on Suppression of Oxidation of Edible Plant Oils

Authors: D. G. D. C. L. Munasinghe, M. S. Gunawardana, P. H. P. Prasanna, C. S. Ranadheera, T. Madhujith

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Lipid oxidation is an important process that affects the shelf life of edible oils. Oxidation produces off flavors, off odors and chemical compounds that lead to adverse health effects. Chemical mechanisms such as autoxidation, photo-oxidation and thermal oxidation are responsible for lipid oxidation. Refined, Bleached and Deodorized (RBD) coconut oil, Virgin Coconut Oil (VCO) and corn oil are widely used plant oils. Pomegranate fruit is known to possess high antioxidative efficacy. Peel of pomegranate contains high antioxidant activity than aril and pulp membrane. The study attempted to study the effect of particle size and concentration of pomegranate peel powder on suppression of oxidation of RBD coconut oil, VCO and corn oil. Pomegranate peel powder was incorporated into each oil sample as micro (< 250 µm) and nano particles (280 - 300 nm) at 100 ppm and 200 ppm concentrations. The control sample of each oil was prepared, devoid of pomegranate peel powder. The stability of oils against autoxidation was evaluated by storing oil samples at 60 °C for 28 days. The level of oxidation was assessed by peroxide value and thiobarbituric acid reactive substances on 0,1,3,5,7,14 and 28 day, respectively. VCO containing pomegranate particles of 280 - 300 nm at 200 ppm showed the highest oxidative stability followed by RBD coconut oil and corn oil. Results revealed that pomegranate peel powder with 280 - 300 nm particle size at 200 ppm concentration was the best in mitigating oxidation of RBD coconut oil, VCO and corn oil. There is a huge potential of utilizing pomegranate peel powder as an antioxidant agent in reducing oxidation of edible plant oils.

Keywords: antioxidant, autoxidation, micro particles, nano particles, pomegranate peel powder

Procedia PDF Downloads 450
447 Force Measurement for E-Cadherin-Mediated Intercellular Adhesion Probed by Protein Micropattern and Traction Force Microscopy

Authors: Chieh-Chung Tsou, Chun-Min Lo, Yeh-Shiu Chu

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Cell’s mechanical forces provide important physical cues in regulation of proper cellular functions, such as cell differentiation, proliferation and migration. It is believed that adhesive forces generated by cell-cell interaction are able to transmit to the interior of cell through filamentous cortical cytoskeleton. Prominent among other membrane receptors, Cadherins are prototypical adhesive molecules able to generate remarkable forces to regulate intercellular adhesion. However, the mechanistic steps of mechano-transduction in Cadherin-mediated adhesion remain very controversial. We are interested in understanding how Cadherin protein complexes enable force generation and transmission at cell-cell contact in the initial stage of intercellular adhesion. For providing a better control of time, space, and substrate stiffness, in this study, a combination of protein micropattern, micropipette manipulation, and traction force microscopy is used. Pair micropattern with different forms confines cell spreading area and the gaps in pairs varied from 2 to 8 microns are applied for monitoring the forces that cell pairs generated, measured by traction force microscopy. Moreover, cell clones obtained from epithelial cells undergone genome editing are used to score the importance for known components of Cadherin complexes in force generation. We believe that our results from this combinatory mechanobiological method will provide deep insights on understanding the biophysical principle governing mechano- transduction of Cadherin-mediated intercellular adhesion.

Keywords: cadherin, intercellular adhesion, protein micropattern, traction force microscopy

Procedia PDF Downloads 249
446 Monitor Vehicle Speed Using Internet of Things Based Wireless Sensor Network System

Authors: Akber Oumer Abdurezak

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Road traffic accident is a major problem in Ethiopia, resulting in the deaths of many people and potential injuries and crash every year and loss of properties. According to the Federal Transport Authority, one of the main causes of traffic accident and crash in Ethiopia is over speeding. Implementation of different technologies is used to monitor the speed of vehicles in order to minimize accidents and crashes. This research aimed at designing a speed monitoring system to monitor the speed of travelling vehicles and movements, reporting illegal speeds or overspeeding vehicles to the concerned bodies. The implementation of the system is through a wireless sensor network. The proposed system can sense and detect the movement of vehicles, process, and analysis the data obtained from the sensor and the cloud system. The data is sent to the central controlling server. The system contains accelerometer and gyroscope sensors to sense and collect the data of the vehicle. Arduino to process the data and Global System for Mobile Communication (GSM) module for communication purposes to send the data to the concerned body. When the speed of the vehicle exceeds the allowable speed limit, the system sends a message to database as “over speeding”. Both accelerometer and gyroscope sensors are used to collect acceleration data. The acceleration data then convert to speed, and the corresponding speed is checked with the speed limit, and those above the speed limit are reported to the concerned authorities to avoid frequent accidents. The proposed system decreases the occurrence of accidents and crashes due to overspeeding and can be used as an eye opener for the implementation of other intelligent transport system technologies. This system can also integrate with other technologies like GPS and Google Maps to obtain better output.

Keywords: accelerometer, IOT, GSM, gyroscope

Procedia PDF Downloads 74
445 Slow and Controlled Release Fertilizer Technology via Application of Plant-available Inorganic Coatings

Authors: Eugene Rybin

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Reduction of nutrient losses when using mineral fertilizers is a very important and urgent challenge, which is of both economic and environmental significance. This paper shows the production of slow- and controlled release fertilizers through application of inorganic coatings, which make the released nutrients plant-available. The method of production of coated fertilizers with inorganic cover material is an alternative to other methods where polymer coatings are used. The method is based on spraying an aqueous slurry onto the surface of granules with simultaneous drying in drums under certain conditions and subsequent cooling of granules. This method of production of slow- and controlled-release fertilizers is more ecofriendly compared with others because inorganic materials are used to create a membrane. That is why the coating material is definitely biodegradable. There is also shown the effect of these coatings on the properties of fertilizers, as well as on the agrochemical efficiency and nutrient efficiency/ availability to the plants. The agrochemical tests have proved the increase of nutrient efficiency for every nutrient in compound fertilizers (NPK, NPS) for 3 consecutive years by 10-20 % and by 25-28% for urea, as well as an increase in crop yield, by 10-15% in general, and its quality. Moreover, the decrease in caking by almost 70% was proven as well as slowing down the release rate of nutrients from fertilizers. Control of the release rate was achieved by regulation of thickness and contents of coating materials. All of those characteristics were researched according to the standard-used methods. The performed research has developed the fertilizer technology of slow- and controlled release of nutrients through applying of plant-available inorganic coatings. It leads to a better synchronization of nutrient release rate and plants needs, as well as reduces the harmful effects on the environment from the fertilizers applied.

Keywords: controlled release, fertilizers, nutrients, plant-available coatings

Procedia PDF Downloads 94
444 Approximation of Geodesics on Meshes with Implementation in Rhinoceros Software

Authors: Marian Sagat, Mariana Remesikova

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In civil engineering, there is a problem how to industrially produce tensile membrane structures that are non-developable surfaces. Nondevelopable surfaces can only be developed with a certain error and we want to minimize this error. To that goal, the non-developable surfaces are cut into plates along to the geodesic curves. We propose a numerical algorithm for finding approximations of open geodesics on meshes and surfaces based on geodesic curvature flow. For practical reasons, it is important to automatize the choice of the time step. We propose a method for automatic setting of the time step based on the diagonal dominance criterion for the matrix of the linear system obtained by discretization of our partial differential equation model. Practical experiments show reliability of this method. Because approximation of the model is made by numerical method based on classic derivatives, it is necessary to solve obstacles which occur for meshes with sharp corners. We solve this problem for big family of meshes with sharp corners via special rotations which can be seen as partial unfolding of the mesh. In practical applications, it is required that the approximation of geodesic has its vertices only on the edges of the mesh. This problem is solved by a specially designed pointing tracking algorithm. We also partially solve the problem of finding geodesics on meshes with holes. We implemented the whole algorithm in Rhinoceros (commercial 3D computer graphics and computer-aided design software ). It is done by using C# language as C# assembly library for Grasshopper, which is plugin in Rhinoceros.

Keywords: geodesic, geodesic curvature flow, mesh, Rhinoceros software

Procedia PDF Downloads 145
443 Ergosterol Biosynthesis: Non-Conventional Method for Improving Process

Authors: Madalina Postaru, Alexandra Tucaliuc, Dan Cascaval, Anca Irina Galaction

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Ergosterol (ergosta-5,7,22-trien-3β-ol) is the precursor of vitamin D2 (ergocalciferol), known as provitamin D2 as it is converted under UV radiation to this vitamin. The natural sources of ergosterol are mainly the yeasts (Saccharomyces sp., Candida sp.), but it can be also found in fungus (Claviceps sp.) or plants (orchids). As ergosterol is mainly accumulated in yeast cell membranes, especially in free form in the plasma-membrane, and the chemical synthesis of ergosterol does not represent an efficient method for its production, this study aimed to analyze the influence of aeration efficiency on ergosterol production by S. cerevisiae in batch and fed-batch fermentations, by considering different levels of mixing intensity, aeration rate, and n-dodecane concentration. Our previous studies on ergosterol production by S. cerevisiae in batch and fed-batch fermentation systems indicated that the addition of n-dodecane led to the increase of almost 50% of this sterol concentration, the highest productivity being reached for the fed-batch process. The experiments were carried out in a laboratory stirred bioreactor, provided with computer-controlled and recorded parameters. In batch fermentation system, the study indicated that the oxygen mass transfer coefficient, kLa, is amplified for about 3 times by increasing the volumetric concentration of n-dodecane from 0 to 15%. Moreover, the increase of dissolved oxygen concentration by adding n-dodecane leads to the diminution for 3.5 times of the produced alcohol amount. In fed-batch fermentation process, the positive influence of hydrocarbon on oxygen transfer rate is amplified mainly at its higher concentration level, as the result of the increased yeasts cells amount. Thus, by varying n-dodecane concentration from 0 to 15% vol., the kLa value increase becomes more important than for the batch fermentation, being of 4 times

Keywords: ergosterol, yeast fermentation, n-dodecane, oxygen-vector

Procedia PDF Downloads 114
442 Evaluation of Model-Based Code Generation for Embedded Systems–Mature Approach for Development in Evolution

Authors: Nikolay P. Brayanov, Anna V. Stoynova

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Model-based development approach is gaining more support and acceptance. Its higher abstraction level brings simplification of systems’ description that allows domain experts to do their best without particular knowledge in programming. The different levels of simulation support the rapid prototyping, verifying and validating the product even before it exists physically. Nowadays model-based approach is beneficial for modelling of complex embedded systems as well as a generation of code for many different hardware platforms. Moreover, it is possible to be applied in safety-relevant industries like automotive, which brings extra automation of the expensive device certification process and especially in the software qualification. Using it, some companies report about cost savings and quality improvements, but there are others claiming no major changes or even about cost increases. This publication demonstrates the level of maturity and autonomy of model-based approach for code generation. It is based on a real live automotive seat heater (ASH) module, developed using The Mathworks, Inc. tools. The model, created with Simulink, Stateflow and Matlab is used for automatic generation of C code with Embedded Coder. To prove the maturity of the process, Code generation advisor is used for automatic configuration. All additional configuration parameters are set to auto, when applicable, leaving the generation process to function autonomously. As a result of the investigation, the publication compares the quality of generated embedded code and a manually developed one. The measurements show that generally, the code generated by automatic approach is not worse than the manual one. A deeper analysis of the technical parameters enumerates the disadvantages, part of them identified as topics for our future work.

Keywords: embedded code generation, embedded C code quality, embedded systems, model-based development

Procedia PDF Downloads 241
441 Effects of Achillea millefolium L. Extract on Rat Spermatogenesis

Authors: Nasrin Takzaree, Gholamreza Hassanzadeh, Abbas Hadjiakhoondi, Mohammadreza Rouini

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Introduction: Today herbal medicine are extensively used for various therapeutic reasons. Whereas Achillea millefolium L. comprises different chemical compounds it is used in classic and modern medicine for different purposes. Concerning the family planning as a principle matter, the idea of using specific herbal medicine is of great importance. Purpose: To investigate the effects of Achillea millefolium L. extract on fertility power and spermatogenesis process in male mature Wistar rats and the anti-fertility effects of this extract in male genital system. Material and methods: In this study 32 male mature Wistar rats were randomly divided in to 4 experimental groups. 1st experimental group included 8 rats receiving Achillea millefolium extract at the dose of 200 mg/kg intraperitoneally. Second and third groups received the extract the same at the doses of 400 and 800 mg/kg respectively. 4th group was considered as control group in which the parenteral distilled water was administered. after 20 days, rats were sacrificed and the spermatogenesis process was histologically examined. Results: In experimental groups receiving high doses of extract comparing with control group, thickness in seminiferous tubules basal membrane, decrease in germinal epithelium cells, congestion in testicular tissue, disarrangement in germinal epithelium cells as well as decrease in cellular condense were observed (p<0.001). Conclusion: Findings suggest that alcoholic extract of Achillea millefolium at high concentrations lead to the structural alterations and changes in spermatogenesis in testicular tissue.

Keywords: spermatogenesis, alcoholic extract of Achillea millefolium L., testis, Wistar rat

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440 Valorisation of Waste Chicken Feathers: Electrospun Antibacterial Nanoparticles-Embedded Keratin Composite Nanofibers

Authors: Lebogang L. R. Mphahlele, Bruce B. Sithole

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Chicken meat is the highest consumed meat in south Africa, with a per capita consumption of >33 kg yearly. Hence, South Africa produces over 250 million kg of waste chicken feathers each year, the majority of which is landfilled or incinerated. The discarded feathers have caused environmental pollution and natural protein resource waste. Therefore, the valorisation of waste chicken feathers is measured as a more environmentally friendly and cost-effective treatment. Feather contains 91% protein, the main component being beta-keratin, a fibrous and insoluble structural protein extensively cross linked by disulfide bonds. Keratin is usually converted it into nanofibers via electrospinning for a variety of applications. keratin nanofiber composites have many potential biomedical applications for their attractive features, such as high surface-to-volume ratio and very high porosity. The application of nanofibers in the biomedical wound dressing requires antimicrobial properties for materials. One approach is incorporating inorganic nanoparticles, among which silver nanoparticles played an important alternative antibacterial agent and have been studied against many types of microbes. The objective of this study is to combine synthetic polymer, chicken feather keratin, and antibacterial nanoparticles to develop novel electrospun antibacterial nanofibrous composites for possible wound dressing application. Furthermore, this study will converting a two-dimensional electrospun nanofiber membrane to three-dimensional fiber networks that resemble the structure of the extracellular matrix (ECM)

Keywords: chicken feather keratin, nanofibers, nanoparticles, nanocomposites, wound dressing

Procedia PDF Downloads 127
439 Quantifying Wave Attenuation over an Eroding Marsh through Numerical Modeling

Authors: Donald G. Danmeier, Gian Marco Pizzo, Matthew Brennan

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Although wetlands have been proposed as a green alternative to manage coastal flood hazards because of their capacity to adapt to sea level rise and provision of multiple ecological and social co-benefits, they are often overlooked due to challenges in quantifying the uncertainty and naturally, variability of these systems. This objective of this study was to quantify wave attenuation provided by a natural marsh surrounding a large oil refinery along the US Gulf Coast that has experienced steady erosion along the shoreward edge. The vegetation module of the SWAN was activated and coupled with a hydrodynamic model (DELFT3D) to capture two-way interactions between the changing water level and wavefield over the course of a storm event. Since the marsh response to relative sea level rise is difficult to predict, a range of future marsh morphologies is explored. Numerical results were examined to determine the amount of wave attenuation as a function of marsh extent and the relative contributions from white-capping, depth-limited wave breaking, bottom friction, and flexing of vegetation. In addition to the coupled DELFT3D-SWAN modeling of a storm event, an uncoupled SWAN-VEG model was applied to a simplified bathymetry to explore a larger experimental design space. The wave modeling revealed that the rate of wave attenuation reduces for higher surge but was still significant over a wide range of water levels and outboard wave heights. The results also provide insights to the minimum marsh extent required to fully realize the potential wave attenuation so the changing coastal hazards can be managed.

Keywords: green infrastructure, wave attenuation, wave modeling, wetland

Procedia PDF Downloads 130
438 Re-Imagining Physical Education Teacher Education in a South African Higher Education Institution

Authors: C. F. Jones Couto, L. C. Motlhaolwa, K. Williams

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This article explores the re-imagining of physical education teacher education in South African higher education. Utilising student reflections from a physical education practical module, valuable insights into student experiences were obtained about the current physical education pedagogical approaches and potential areas for improvement. The traditional teaching model of physical education is based on the idea of teaching students a variety of sports and physical activities. However, this model has been shown to be ineffective in promoting lifelong physical activity. The modern world demands a more holistic approach to health and wellness. Data was collected using the arts-based collage method in combination with written group reflections from 139 second-year undergraduate physical education students. This study employed thematic analysis methods to gain a comprehensive understanding of the data and extract a broader perspective on the students' experiences. The study aimed to empower student teachers to learn, think, and act creatively within the many educational models that impact their experience, contributing to the ongoing efforts of re-imagining physical education teacher education in South African higher education. This research is significant as the students' valuable insights reflected that they can think and work across disciplines. Sustainable development goals and graduate attributes are important concepts that can contribute to student preparation. Using a multi-model educational approach based on the cultural-historical theory, higher education institutions can help develop graduate attributes that will prepare students for success in the workplace and life.

Keywords: holistic education, graduate attributes, physical education, teacher education, student experiences, sustainable development goals

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437 Structure-Based Drug Design of Daptomycin, Antimicrobial lipopeptide

Authors: Satya Eswari Jujjavarapu, Swast Dhagat

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Contagious diseases enact severe public health problems and have upsetting consequences. The cyclic lipopeptides explained by bacteria Bacillus, Paenibacillus, Pseudomonas, Streptomyces, Serratia, Propionibacterium and fungus Fusarium are very critical in confining the pathogens. As the degree of drug resistance upsurges in unparalleled manner, the perseverance of searching novel cyclic lipopeptides is being professed. The intense study has shown the implication of these bioactive compounds extending beyond antibacterial and antifungal. Lipopeptides, composed of single units of peptide and fatty acyl moiety, show broad spectrum antimicrobial effects. Among the surplus of cyclic lipopeptides, only few have materialized as strong antibiotics. For their functional vigor, polymyxin, daptomycin, surfactin, iturin and bacillomycin have been integrated in mainstream healthcare. In our work daptomycin has been a major part of antimicrobial resource since the past decade. Daptomycin, a cyclic lipopeptide consists of 13-member amino acid with a decanoyl side-chain. This structure of daptomycin confers it the mechanism of action through which it forms pore in the bacterial cell membrane resulting in the death of cell. Daptomycin is produced by Streptococccus roseoporus and acts against Streptococcus pneumonia (PSRP), methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE). The PDB structure and ligands of daptomycin are available online. The molecular docking studies of these ligands with the lipopeptides were performed and their docking score and glide energy were recorded.

Keywords: daptomycin, molecular docking, structure-based drug design, lipopeptide

Procedia PDF Downloads 263
436 Enhancing Sensitization of Cervical Cancer Cells to γ-Radiation Ellagic Acid

Authors: Vidhula Ahire, Amit Kumar, K. P. Mishra, Gauri Kulkarni

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Herbal polyphenols have gained significance because of their increasing promise in prevention and treatment of cancer. Therefore, development of a dietary compound as an effective radiosensitizer and a radioprotector is highly warranted for cervical cancer patients undergoing therapy. This study describes the cytotoxic effects of the flavonoid, ellagic acid (EA) when administered either alone or in combination with gamma radiation on cervical cancer HeLa cells in vitro. Apoptotic index and proliferation were measured by using trypan blue assay. Reproductive cell death was analyzed by clonogenic assay. Propidium iodide staining for flowcytometry was performed to analyze cell cycle modulation. Nuclear and mitochondrial changes were studied with specific dyes. DNA repair kinetics was analyzed by immunofluorescence assay. Evaluation and comparison of EA effects were performed with other clinically used breast cancer drugs. When tumor cells were exposed to 2 and 4 Gy of irradiation in presence of EA (10 μM), it yielded a synergistic cytotoxic effect on cervical cancer cells whereas in NIH3T3 cells it reversed the injury caused by irradiation and abetted in the regaining of normal healthy cells. At 24h ~25foci/cell was observed and 2.6 fold decrease in the mitochondrial membrane potential. Up to 40% cell were arrested in the G1 phase and 20-36% cells exhibited apoptosis. Our results demonstrate the role of increased apoptosis and cell cycle modulation in the mechanism of EA mediated radiosensitization of cervical cancer cells and thus advocating EA as an adjuvant for preclinical trials in cancer chemo- radiotherapy.

Keywords: cervical cancer, ellagic acid, sensitization, radiation therapy

Procedia PDF Downloads 319
435 Trial of Resorbable versus Non-Resorbable Sutures for Traumatic Lacerations of the Face: A Demonstration of Maxillo-Facial Trainee Led Research

Authors: R. Botrugno, S Basyuni, G. Nugent, I. Jenkyn, A. Ferro, H. Bennett, C. Hjalmarsson, J. Chu, V. Santhanam

Abstract:

This trainee led randomised controlled trial (RCT) aims to assess various outcomes for resorbable versus non-resorbable sutures for traumatic lacerations to the face. Within this trial of resorbable versus non-resorbable sutures for traumatic lacerations of the face (TORNFace), patient recruitment was facilitated by trainees who were employed at an NHS University Teaching Hospital in the United Kingdom. The trainees received appropriate training prior to recruiting patients for the trial. This included the completion of a national research e-learning module and face-to-face training that was provided locally. The locally delivered training provided an understanding of the eligibility criteria for the trial and the consent process. Existing trainee skills were utilised involving clinical photography to record baseline data and delivering the intervention based on the treatment arm selected. Eligible patients who required primary closure of traumatic lacerations of the face were randomised into one of two treatment arms. These comprised of resorbable (vicryl rapide) or non-resorbable sutures (ethilon). Primarily the cosmetic outcome was assessed. Secondary outcomes included: complications rates, health care economics, and patient-reported outcomes. Remote follow-up of recruited patients utilised photographs of the facial laceration which had received the intervention. These took place at 1 week, 3 months and 6 months post-intervention. This study aims to demonstrate an example of trainee-led research within the specialty of oral and maxillofacial surgery. The available data for the randomised controlled trial will also be presented.

Keywords: laceration, suture, trauma, trial

Procedia PDF Downloads 135
434 Unveiling the Self-Assembly Behavior and Salt-Induced Morphological Transition of Double PEG-Tailed Unconventional Amphiphiles

Authors: Rita Ghosh, Joykrishna Dey

Abstract:

PEG-based amphiphiles are of tremendous importance for its widespread applications in pharmaceutics, household purposes, and drug delivery. Previously, a number of single PEG-tailed amphiphiles having significant applications have been reported from our group. Therefore, it was of immense interest to explore the properties and application potential of PEG-based double tailed amphiphiles. Herein, for the first time, two novel double PEG-tailed amphiphiles having different PEG chain lengths have been developed. The self-assembly behavior of the newly developed amphiphiles in aqueous buffer (pH 7.0) was thoroughly investigated at 25 oC by a number of techniques including, 1H-NMR, and steady-state and time-dependent fluorescence spectroscopy, dynamic light scattering, transmission electron microscopy, atomic force microscopy, and isothermal titration calorimetry. Despite having two polar PEG chains both molecules were found to have strong tendency to self-assemble in aqueous buffered solution above a very low concentration. Surprisingly, the amphiphiles were shown to form stable vesicles spontaneously at room temperature without any external stimuli. The results of calorimetric measurements showed that the vesicle formation is driven by the hydrophobic effect (positive entropy change) of the system, which is associated with the helix-to-random coil transition of the PEG chain. The spectroscopic data confirmed that the bilayer membrane of the vesicles is constituted by the PEG chains of the amphiphilic molecule. Interestingly, the vesicles were also found to exhibit structural transitions upon addition of salts in solution. These properties of the vesicles enable them as potential candidate for drug delivery.

Keywords: double-tailed amphiphiles, fluorescence, microscopy, PEG, vesicles

Procedia PDF Downloads 116
433 Human Resource Information System: Role in HRM Practices and Organizational Performance

Authors: Ejaz Ali M. Phil

Abstract:

Enterprise Resource Planning (ERP) systems are playing a vital role in effective management of business functions in large and complex organizations. Human Resource Information System (HRIS) is a core module of ERP, providing concrete solutions to implement Human Resource Management (HRM) Practices in an innovative and efficient manner. Over the last decade, there has been considerable increase in the studies on HRIS. Nevertheless, previous studies relatively lacked to examine the moderating role of HRIS in performing HRM practices that may affect the firms’ performance. The current study was carried out to examine the impact of HRM practices (training, performance appraisal) on perceived organizational performance, with moderating role of HRIS, where the system is in place. The study based on Resource Based View (RBV) and Ability Motivation Opportunity (AMO) Theories, advocating that strengthening of human capital enables an organization to achieve and sustain competitive advantage which leads to improved organizational performance. Data were collected through structured questionnaire based upon adopted instruments after establishing reliability and validity. The structural equation modeling (SEM) were used to assess the model fitness, hypotheses testing and to establish validity of the instruments through Confirmatory Factor Analysis (CFA). A total 220 employees of 25 firms in corporate sector were sampled through non-probability sampling technique. Path analysis revealing that HRM practices and HRIS have significant positive impact on organizational performance. The results further showed that the HRIS moderated the relationships between training, performance appraisal and organizational performance. The interpretation of the findings and limitations, theoretical and managerial implications are discussed.

Keywords: enterprise resource planning, human resource, information system, human capital

Procedia PDF Downloads 391
432 Molecular Modeling a Tool for Postulating the Mechanism of Drug Interaction: Glimepiride Alters the Pharmacokinetics of Sildenafil Citrate in Diabetic Nephropathy Animals

Authors: Alok Shiomurti Tripathi, Ajay Kumar Timiri, Papiya Mitra Mazumder, Anil Chandewar

Abstract:

The present study evaluates the possible drug interaction between glimepiride (GLIM) and sildenafil citrate (SIL) in streptozotocin (STZ) induced in diabetic nephropathic (DN) animals and also postulates the possible mechanism of interaction by molecular modeling studies. Diabetic nephropathy was induced by single dose of STZ (60 mg/kg, ip) and confirms it by assessing the blood and urine biochemical parameters on 28th day of its induction. Selected DN animals were used for the drug interaction between GLIM (0.5mg/kg, p.o.) and SIL (2.5 mg/kg, p.o.) after 29th and 70th day of protocol. Drug interaction were assessed by evaluating the plasma drug concentration using HPLC-UV and also determine the change in the biochemical parameter in blood and urine. Mechanism of the interaction was postulated by molecular modeling study using Maestro module of Schrodinger software. DN was confirmed as there was significant alteration in the blood and urine biochemical parameter in STZ treated groups. The concentration of SIL increased significantly (p<0.001) in rat plasma when co administered with GLIM after 70th day of protocol. Molecular modelling study revealed few important interactions with rat serum albumin and CYP2C9.GLIM has strong hydrophobic interaction with binding site residues of rat serum albumin compared to SIL. Whereas, for CYP2C9, GLIM has strong hydrogen bond with polar contacts and hydrophobic interactions than SIL. Present study concludes that bioavailability of SIL increases when co-administered chronically with GLIM in the management of DN animals and mechanism has been supported by molecular modeling studies.

Keywords: diabetic nephropathy, glimepiride, sildenafil citrate, pharmacokinetics, homology modeling, schrodinger

Procedia PDF Downloads 372
431 SEM Detection of Folate Receptor in a Murine Breast Cancer Model Using Secondary Antibody-Conjugated, Gold-Coated Magnetite Nanoparticles

Authors: Yasser A. Ahmed, Juleen M Dickson, Evan S. Krystofiak, Julie A. Oliver

Abstract:

Cancer cells urgently need folate to support their rapid division. Folate receptors (FR) are over-expressed on a wide range of tumor cells, including breast cancer cells. FR are distributed over the entire surface of cancer cells, but are polarized to the apical surface of normal cells. Targeting of cancer cells using specific surface molecules such as folate receptors may be one of the strategies used to kill cancer cells without hurting the neighing normal cells. The aim of the current study was to try a method of SEM detecting FR in a murine breast cancer cell model (4T1 cells) using secondary antibody conjugated to gold or gold-coated magnetite nanoparticles. 4T1 cells were suspended in RPMI medium witth FR antibody and incubated with secondary antibody for fluorescence microscopy. The cells were cultured on 30mm Thermanox coverslips for 18 hours, labeled with FR antibody then incubated with secondary antibody conjugated to gold or gold-coated magnetite nanoparticles and processed to scanning electron microscopy (SEM) analysis. The fluorescence microscopy study showed strong punctate FR expression on 4T1 cell membrane. With SEM, the labeling with gold or gold-coated magnetite conjugates showed a similar pattern. Specific labeling occurred in nanoparticle clusters, which are clearly visualized in backscattered electron images. The 4T1 tumor cell model may be useful for the development of FR-targeted tumor therapy using gold-coated magnetite nano-particles.

Keywords: cancer cell, nanoparticles, cell culture, SEM

Procedia PDF Downloads 731
430 Multi-Impairment Compensation Based Deep Neural Networks for 16-QAM Coherent Optical Orthogonal Frequency Division Multiplexing System

Authors: Ying Han, Yuanxiang Chen, Yongtao Huang, Jia Fu, Kaile Li, Shangjing Lin, Jianguo Yu

Abstract:

In long-haul and high-speed optical transmission system, the orthogonal frequency division multiplexing (OFDM) signal suffers various linear and non-linear impairments. In recent years, researchers have proposed compensation schemes for specific impairment, and the effects are remarkable. However, different impairment compensation algorithms have caused an increase in transmission delay. With the widespread application of deep neural networks (DNN) in communication, multi-impairment compensation based on DNN will be a promising scheme. In this paper, we propose and apply DNN to compensate multi-impairment of 16-QAM coherent optical OFDM signal, thereby improving the performance of the transmission system. The trained DNN models are applied in the offline digital signal processing (DSP) module of the transmission system. The models can optimize the constellation mapping signals at the transmitter and compensate multi-impairment of the OFDM decoded signal at the receiver. Furthermore, the models reduce the peak to average power ratio (PAPR) of the transmitted OFDM signal and the bit error rate (BER) of the received signal. We verify the effectiveness of the proposed scheme for 16-QAM Coherent Optical OFDM signal and demonstrate and analyze transmission performance in different transmission scenarios. The experimental results show that the PAPR and BER of the transmission system are significantly reduced after using the trained DNN. It shows that the DNN with specific loss function and network structure can optimize the transmitted signal and learn the channel feature and compensate for multi-impairment in fiber transmission effectively.

Keywords: coherent optical OFDM, deep neural network, multi-impairment compensation, optical transmission

Procedia PDF Downloads 140
429 Determination of Antioxidant Activity in Raphanus raphanistrum L.

Authors: Esma Hande Alıcı, Gülnur Arabacı

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Antioxidants are compounds or systems that can safely interact with free radicals and terminate the chain reaction before vital molecules are damaged. The anti-oxidative effectiveness of these compounds depends on their chemical characteristics and physical location within a food (proximity to membrane phospholipids, emulsion interfaces, or in the aqueous phase). Antioxidants (e.g., flavonoids, phenolic acids, tannins, vitamin C, vitamin E) have diverse biological properties, such as antiinflammatory, anti-carcinogenic and anti-atherosclerotic effects, reduce the incidence of coronary diseases and contribute to the maintenance of gut health by the modulation of the gut microbial balance. Plants are excellent sources of antioxidants especially with their high content of phenolic compounds. Raphanus raphanistrum L., the wild radish, is a flowering plant in the family Brassicaceae. It grows in Asia and Mediterranean region. It has been introduced into most parts of the world. It spreads rapidly, and is often found growing on roadsides or in other places where the ground has been disturbed. It is an edible plant, in Turkey its fresh aerial parts are mostly consumed as a salad with olive oil and lemon juice after boiled. The leaves of the plant are also used as anti-rheumatic in traditional medicine. In this study, we determined the antioxidant capacity of two different solvent fractions (methanol and ethyl acetate) obtained from Raphanus raphanistrum L. plant leaves. Antioxidant capacity of the plant was introduced by using three different methods: DPPH radical scavenging activity, CUPRAC (Cupric Ion Reducing Antioxidant Capacity) activity and Reducing power activity.

Keywords: antioxidant activity, antioxidant capacity, Raphanis raphanistrum L., wild radish

Procedia PDF Downloads 274
428 Insight into the Binding Theme of CA-074Me to Cathepsin B: Molecular Dynamics Simulations and Scaffold Hopping to Identify Potential Analogues as Anti-Neurodegenerative Diseases

Authors: Tivani Phosa Mashamba-Thompson, Mahmoud E. S. Soliman

Abstract:

To date, the cause of neurodegeneration is not well understood and diseases that stem from neurodegeneration currently have no known cures. Cathepsin B (CB) enzyme is known to be involved in the production of peptide neurotransmitters and toxic peptides in neurodegenerative diseases (NDs). CA-074Me is a membrane-permeable irreversible selective cathepsin B (CB) inhibitor as confirmed by in vivo studies. Due to the lack of the crystal structure, the binding mode of CA-074Me with the human CB at molecular level has not been previously reported. The main aim of this study is to gain an insight into the binding mode of CB CA-074Me to human CB using various computational tools. Herein, molecular dynamics simulations, binding free energy calculations and per-residue energy decomposition analysis were employed to accomplish the aim of the study. Another objective was to identify novel CB inhibitors based on the structure of CA-074Me using fragment based drug design using scaffold hoping drug design approach. Results showed that two of the designed ligands (hit 1 and hit 2) were found to have better binding affinities than the prototype inhibitor, CA-074Me, by ~2-3 kcal/mol. Per-residue energy decomposition showed that amino acid residues Cys29, Gly196, His197 and Val174 contributed the most towards the binding. The Van der Waals binding forces were found to be the major component of the binding interactions. The findings of this study should assist medicinal chemist towards the design of potential irreversible CB inhibitors.

Keywords: cathepsin B, scaffold hopping, docking, molecular dynamics, binding-free energy, neurodegerative diseases

Procedia PDF Downloads 374
427 Biophysical Consideration in the Interaction of Biological Cell Membranes with Virus Nanofilaments

Authors: Samaneh Farokhirad, Fatemeh Ahmadpoor

Abstract:

Biological membranes are constantly in contact with various filamentous soft nanostructures that either reside on their surface or are being transported between the cell and its environment. In particular, viral infections are determined by the interaction of viruses (such as filovirus) with cell membranes, membrane protein organization (such as cytoskeletal proteins and actin filament bundles) has been proposed to influence the mechanical properties of lipid membranes, and the adhesion of filamentous nanoparticles influence their delivery yield into target cells or tissues. The goal of this research is to integrate the rapidly increasing but still fragmented experimental observations on the adhesion and self-assembly of nanofilaments (including filoviruses, actin filaments, as well as natural and synthetic nanofilaments) on cell membranes into a general, rigorous, and unified knowledge framework. The global outbreak of the coronavirus disease in 2020, which has persisted for over three years, highlights the crucial role that nanofilamentbased delivery systems play in human health. This work will unravel the role of a unique property of all cell membranes, namely flexoelectricity, and the significance of nanofilaments’ flexibility in the adhesion and self-assembly of nanofilaments on cell membranes. This will be achieved utilizing a set of continuum mechanics, statistical mechanics, and molecular dynamics and Monte Carlo simulations. The findings will help address the societal needs to understand biophysical principles that govern the attachment of filoviruses and flexible nanofilaments onto the living cells and provide guidance on the development of nanofilament-based vaccines for a range of diseases, including infectious diseases and cancer.

Keywords: virus nanofilaments, cell mechanics, computational biophysics, statistical mechanics

Procedia PDF Downloads 89
426 pH-Responsive Carrier Based on Polymer Particle

Authors: Florin G. Borcan, Ramona C. Albulescu, Adela Chirita-Emandi

Abstract:

pH-responsive drug delivery systems are gaining more importance because these systems deliver the drug at a specific time in regards to pathophysiological necessity, resulting in improved patient therapeutic efficacy and compliance. Polyurethane materials are well-known for industrial applications (elastomers and foams used in different insulations and automotive), but they are versatile biocompatible materials with many applications in medicine, as artificial skin for the premature neonate, membrane in the hybrid artificial pancreas, prosthetic heart valves, etc. This study aimed to obtain the physico-chemical characterization of a drug delivery system based on polyurethane microparticles. The synthesis is based on a polyaddition reaction between an aqueous phase (mixture of polyethylene-glycol M=200, 1,4-butanediol and Tween® 20) and an organic phase (lysin-diisocyanate in acetone) combined with simultaneous emulsification. Different active agents (omeprazole, amoxicillin, metoclopramide) were used to verify the release profile of the macromolecular particles in different pH mediums. Zetasizer measurements were performed using an instrument based on two modules: a Vasco size analyzer and a Wallis Zeta potential analyzer (Cordouan Technol., France) in samples that were kept in various solutions with different pH and the maximum absorbance in UV-Vis spectra were collected on a UVi Line 9,400 Spectrophotometer (SI Analytics, Germany). The results of this investigation have revealed that these particles are proper for a prolonged release in gastric medium where they can assure an almost constant concentration of the active agents for 1-2 weeks, while they can be disassembled faster in a medium with neutral pHs, such as the intestinal fluid.

Keywords: lysin-diisocyanate, nanostructures, polyurethane, Zetasizer

Procedia PDF Downloads 180