Search results for: release capability

Authors: Shreya Asthana

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Testers know that the feature they tested on stage is working perfectly in production only after release went live. Sometimes something breaks in production and testers get to know through the end user’s bug raised. The panic mode starts when your staging test results do not reflect current production behavior. And you started doubting your testing skills when finally the user reported a bug to you. Testers can deploy their confidence on release day by testing on production. Once you start doing testing in production, you will see test result accuracy because it will be running on real time data and execution will be a little faster as compared to staging one due to elimination of bad data. Feature flagging, canary releases, and data cleanup can help to achieve this technique of testing. By this paper it will be easier to understand the steps to achieve production testing before making your feature live, and to modify IT company’s testing procedure, so testers can provide the bug free experience to the end users. This study is beneficial because too many people think that testing should be done in staging but not in production and now this is high time to pull out people from their old mindset of testing into a new testing world. At the end of the day, it all just matters if the features are working in production or not.

Keywords: bug free production, new testing mindset, testing strategy, testing approach

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Authors: Yuvraj Singh Dangi, Kamta Prasad Namdeo, Surendra Bodhake

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The purpose of this research was to develop and evaluate mucoadhesive films for buccal administration of itraconazole using film-forming and mucoashesive polymers. Buccal films of chitosan bearing Itraconazole were prepared by solvent casting technique. The films have been evaluated in terms of film weight, thickness, density, surface pH, FTIR, X-ray diffraction analysis, bioadhesion, swelling properties, and in vitro drug release studies. It was found that film formulations of 2 cm2 size having weight in the range of 204 ± 0.76 to 223 ± 2.09 mg and film thickness were in the range of 0.44 ± 0.11 to 0.57 ± 0.19 mm. Density of the films was found to be 0.102 to 0.126 g/ml. Drug content was found to be uniform in the range of 8.23 ± 0.07 to 8.73 ± 0.09 mg/cm2 for formulation A1 to A4. Maximum bioadhesion force was recorded for HPMC buccal films (A2) i.e. 0.57 ± 0.47 as compared to other films. In vitro residence time was in range of 1.7 ± 0.12 to 7.65 ± 0.15 h. The drug release studies show that formulations follow non-fickian diffusion. These mucoadhesive formulations could offer many advantages in comparison to traditional treatments.

Keywords: biovariability, buccal patches, itraconazole, Mucoadhesion

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Authors: Mohammad Mohammadi, Mojtaba Askari, Mohammad Farouq Hossaini

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An intrinsic property of rock mass known as rock bolt supporting factor (RSF) or rock bolting capability of rock mass was developed and used for explanation of the mechanism of rock bolting practice. Based on the theory of RSF, numeral values can be assigned to each given rock mass to show the capability of that rock mass to be reinforced by rock bolting. For determination of shotcrete thickness, both safety and cost must be taken into account. The present paper introduces a scientific approach for determination of the necessary shotcrete thickness in underground structures for support purposes using the concept of rock bolt supporting factor (RSF). The proposed approach makes the outcome of shotcrete design one step more accurate than before. The actual dataset of 500 meters of Alborz Tunnel length is used as an example of the application of the approach.

Keywords: rock bolt supporting factor (RSF), shotcrete design, underground excavation, Alborz Tunnel

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Authors: Ahmed A. D. Sarhan, S. R. Besharaty, Javad Akbaria, M. Hamdi

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The capability of CNC gantry milling machines in manufacturing long components has caused the expanded use of such machines. On the other hand, the machines’ gantry rigidity can reduce under severe loads or vibration during operation. Indeed, the quality of machining is dependent on the machine’s dynamic behavior throughout the operating process. For this reason, this type of machines has always been used prudently and are non efficient. Therefore, they can usually be employed for rough machining and may not produce adequate surface finishing. In this paper, a CNC gantry milling machine with the potential to produce good surface finish has been designed and analyzed. The lowest natural frequency of this machine is 202 Hz at all motion amplitudes with a full range of suitable frequency responses. Meanwhile, the maximum deformation under dead loads for the gantry machine is 0.565µm, indicating that this machine tool is capable of producing higher product quality.

Keywords: frequency response, finite element, gantry machine, gantry design, static and dynamic analysis

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Authors: Pornthep Rachnavy

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The purpose of this paper is twofold. First, we believe that there are a significant relationship between sculling angle and sculling style among adaptive rowing. Second, we introduce a methodology used for adaptive rowing, namely simulation, to identify effectiveness of adaptive rowing. For our study we simulate the arms only single scull of adaptive rowing. The method for rowing fastest under the 1000 meter was investigated by study sculling angle using the simulation modeling. A simulation model of a rowing system was developed using the Matlab software package base on equations of motion consist of many variation for moving the boat such as oars length, blade velocity and sculling style. The boat speed, power and energy consumption on the system were compute. This simulation modeling can predict the force acting on the boat. The optimum sculling angle was performing by computer simulation for compute the solution. Input to the model are sculling style of each rower and sculling angle. Outputs of the model are boat velocity at 1000 meter. The present study suggests that the optimum sculling angle exist depends on sculling styles. The optimum angle for blade entry and release with respect to the perpendicular through the pin of the first style is -57.00 and 22.0 degree. The optimum angle for blade entry and release with respect to the perpendicular through the pin of the second style is -57.00 and 22.0 degree. The optimum angle for blade entry and release with respect to the perpendicular through the pin of the third style is -51.57 and 28.65 degree. The optimum angle for blade entry and release with respect to the perpendicular through the pin of the fourth style is -45.84 and 34.38 degree. A theoretical simulation for rowing has been developed and presented. The results suggest that it may be advantageous for the rowers to select the sculling angles proper to sculling styles. The optimum sculling angles of the rower depends on the sculling styles made by each rower. The investigated of this paper can be concludes in three directions: 1;. There is the optimum sculling angle in arms only single scull of adaptive rowing. 2. The optimum sculling angles depend on the sculling styles. 3. Computer simulation of rowing can identify opportunities for improving rowing performance by utilizing the kinematic description of rowing. The freedom to explore alternatives in speed, thrust and timing with the computer simulation will provide the coach with a tool for systematic assessments of rowing technique In addition, the ability to use the computer to examine the very complex movements during rowing will help both the rower and the coach to conceptualize the components of movements that may have been previously unclear or even undefined.

Keywords: simulation, sculling, adaptive, rowing

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Authors: Anbang Liu, Huaqing Xie, Zihua Wu, Xiaoxiao Yu, Yuanyuan Wang

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Due to the temperature-dependence and mutual coupling of thermoelectric parameters, the Thomson effect always exists, which is derived from temperature gradients during thermoelectric conversion. The synergistic effect between the Thomson effect and non-equilibrium heat transport of charge carriers leads to local heat absorption or release in thermoelements, thereby affecting its power generation performance and conversion efficiency. This study verified and analyzed the influence and mechanism of the Thomson effect on N-type skutterudite thermoelement through quasi-steady state testing under approximate vacuum conditions. The results indicate the temperature rise/fall of N-type thermoelement at any position is affected by Thomson heat release/absorption. Correspondingly, the Thomson effect also contributes advantageously/disadvantageously to the output power of N-type skutterudite thermoelement when the Thomson coefficients are positive/negative. In this work, the output power can be promoted or decreased maximally by more than 27% due to the presence of Thomson heat when the absolute value of the Thomson coefficient is around 36 μV/℃.

Keywords: Thomson effect, heat transport, thermoelectric conversion, numerical simulation

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Authors: Lalnuntluanga Hmar, Hardik Vyas

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Hydraulic fracturing has become an essential procedure to break apart the rock and release the oil or gas which are trapped tightly in the rock by pumping fracturing fluids at high pressure down into the well. To open the fracture and to transport propping agent along the fracture, proper selection of fracturing fluids is the most crucial components in fracturing operations. Rheology properties of the fluids are usually considered the most important. Among various fracturing fluids, Borate crosslinked fluids have proved to be highly effective. Borate in the form of Boric Acid, borate ion is the most commonly use to crosslink the hydrated polymers and to produce very viscous gels that can stable at high temperature. Guar and HPG (Hydroxypropyl Guar) polymers are the most often used in these fluids. Borate gel rheology is known to be a function of polymer concentration, borate ion concentration, pH, and temperature. The crosslinking using Borate is a function of pH which means it can be formed or reversed simply by altering the pH of the fluid system. The fluid system was prepared by mixing base polymer with water at pH ranging between 8 to 11 and the optimum borate crosslinker efficiency was found to be pH of about 10. The rheology of laboratory prepared Borate crosslinked fracturing fluid was determined using Anton Paar Rheometer and Fann Viscometer. The viscosity was measured at high temperature ranging from 200ᵒF to 250ᵒF and pressures in order to partially stimulate the downhole condition. Rheological measurements reported that the crosslinking increases the viscosity, elasticity and thus fluid capability to transport propping agent.

Keywords: borate, crosslinker, Guar, Hydroxypropyl Guar (HPG), rheology

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Authors: P. F. Wong, H. Salleh, F. A. Rahim

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The adoption of building information modeling (BIM) is increasing in the construction industry. However, quantity surveyors are slow in adoption compared to other professions due to lack of awareness of the BIM’s potential in their profession. It is still unclear on how BIM application can enhance quantity surveyors’ work performance and project performance. The aim of this research is to identify the capabilities of BIM in quantity surveying practices and examine the relationship between BIM capabilities and project performance. Questionnaire survey and interviews were adopted for data collection. Literature reviews identified there are eleven BIM capabilities in quantity surveying practice. Questionnaire results showed that there are several BIM capabilities significantly correlated with project performance in time, cost and quality aspects and the results were validated through interviews. These findings show that BIM has the capabilities to enhance quantity surveyors’ performances and subsequently improved project performance.

Keywords: Building Information Modeling (BIM), quantity surveyors, capability, project performance

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Authors: Priya Patel, Paresh Patel, Mihir Raval

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Silibinin, a flavanone as an antimicrotubular agent used in the treatment of cancer, was encapsulated in nanoparticles (NPs) of poly (lactide-co-glycolide) (PLGA) polymer using the spray-drying technique. The effects of various experimental parameters were optimized by box-behnken experimental design. Production yield, encapsulation efficiency and dissolution study along with characterization by scanning electron microscopy, DSC, FTIR followed by bioavailability study. Particle size and zeta potential were evaluated by using zetatrac particle size analyzer. Experimental design it was evaluated that inlet temperature and polymer concentration influence on the drug release. Feed flow rate impact on particle size. Results showed that spray drying technique yield 149 nm indicate nanosize range. The small size of the nanoparticle resulted in an enhanced cellular entry and greater bioavailability. Entrapment efficiency was found between 89.35% and 98.36%. Zeta potential shows good stability index of nanoparticle formulation. The in vitro release studies indicated the silibinin loaded PLGA nanoparticles provide controlled drug release over a period of 32 h. Pharmacokinetic studies demonstrated that after oral administration of silibinin-loaded PLGA nanoparticles to rats at a dose of 10 mg/kg, relative bioavailability was enhanced about 8.85-fold, compared to silibinin suspension as control hence, this investigation demonstrated the potential of the experimental design in understanding the effect of the formulation variables on the quality of silibinin loaded PLGA nanoparticles. These results describe an effective strategy of silibinin loaded PLGA nanoparticles and might provide a promising approach against the cancer.

Keywords: silibinin, cancer, nanoparticles, PLGA, bioavailability

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Authors: Yang Fu, Jaime Rodrigo Navarro, Jose F. Monserrat, Faiza Bouchmal, Oscar Carrasco Quilis

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Cellular Vehicle to Everything (C-V2X) is considered a promising solution for future autonomous driving. From Release 16 to Release 17, the Third Generation Partnership Project (3GPP) has introduced the definitions and services for 5G New Radio (NR) V2X. Experience from previous generations has shown that establishing a simulator for C-V2X communications is an essential preliminary step to achieve reliable and stable communication links. This paper proposes a complete framework of a link-level simulator based on the 3GPP specifications for the Physical Sidelink Share Channel (PSSCH) of the 5G NR Physical Layer (PHY). In this framework, several algorithms in the receiver part, i.e., sliding window in channel estimation and Minimum Mean Square Error (MMSE)-based equalization, are developed. Finally, the performance of the developed PSSCH receiver is validated through extensive simulations under different assumptions.

Keywords: C-V2X, channel estimation, link-level simulator, sidelink, 3GPP

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Authors: Hsing-Hua Stella Chang, Mong-Ching Lin, Cher-Min Fong

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There has recently been a notable rise in the number of emerging-market industrial small and medium-sized enterprises (SMEs) that have managed to upgrade their operations. Evolving from original equipment manufacturing (OEM) into value-added original or own brand manufacturing (OBM) in such firms represents a specific process of internationalization. The OEM-OBM upgrade requires development of a firm’s own brand. In this respect, the extant literature points out that emerging-market industrial marketers (latecomers) have developed some marketing capabilities, of which branding has been identified as one of the most important. In specific, an industrial non-brand marketer (OEM) marks the division of labor between manufacturing and branding (as part of marketing). In light of this discussion, this research argues that branding capability plays a critical role in supporting the evolution of manufacture upgrade. This is because a smooth transformation from OEM to OBM entails the establishment of strong brands through which branding capability is developed. Accordingly, branding capability can be exemplified as a series of processes and practices in relation to mobilizing branding resources and orchestrating branding activities, which will result in the establishment of business relationships, greater acceptance of business partners (channels, suppliers), and increased industrial brand equity in the firm as key resource advantages). For the study purpose, Taiwan was chosen as the research context, representing a typical case that exemplifies the industrial development path of more-established emerging markets, namely, transformation from OEM to OBM. This research adopted a two-phase research design comprising exploratory (a qualitative study) and confirmatory approaches (a survey study) The findings show that: Country-specific advantage is positively related to branding capability for internationalizing SMEs. Firm-specific advantage is positively related to branding capability for internationalizing SMEs. Hsing-Hua Stella Chang is Assistant Professor with National Taichung University of Education, International Master of Business Administration, (Yingcai Campus) No.227, Minsheng Rd., West Dist., Taichung City 40359, Taiwan, R.O.C. (phone: 886-22183612; e-mail: [email protected]). Mong-Ching Lin is PhD candidate with National Sun Yat-Sen University, Department of Business Management, 70 Lien-hai Rd., Kaohsiung 804, Taiwan, R.O.C. (e-mail: [email protected]). Cher-Min Fong is Full Professor with National Sun Yat-Sen University, Department of Business Management, 70 Lien-hai Rd., Kaohsiung 804, Taiwan, R.O.C. (e-mail: [email protected]). Branding capability is positively related to international performance for internationalizing SMEs. This study presents a pioneering effort to distinguish industrial brand marketers from non-brand marketers in exploring the role of branding capability in the internationalizing small and medium-sized industrial brand marketers from emerging markets. Specifically, when industrial non-brand marketers (OEMs) enter into a more advanced stage of internationalization (i.e., OBM), they must overcome disadvantages (liabilities of smallness, foreignness, outsidership) that do not apply in the case of incumbent developed-country MNEs with leading brands. Such critical differences mark the urgency and significance of distinguishing industrial brand marketers from non-brand marketers on issues relating to their value-adding branding and marketing practices in international markets. This research thus makes important contributions to the international marketing, industrial branding, and SME internationalization literature.

Keywords: brand marketers, branding capability, emerging markets, SME internationalization

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Authors: Darren Zou

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Forecasting the stock market is a very challenging task. Various economic indicators such as GDP, exchange rates, interest rates, and unemployment have a substantial impact on the stock market. Time series models are the traditional methods used to predict stock market changes. In this paper, a machine learning method, Bayesian Additive Regression Tree (BART) is used in predicting stock market indexes based on multiple economic indicators. BART can be used to model heterogeneous treatment effects, and thereby works well when models are misspecified. It also has the capability to handle non-linear main effects and multi-way interactions without much input from financial analysts. In this research, BART is proposed to provide a reliable prediction on day-to-day stock market activities. By comparing the analysis results from BART and with time series method, BART can perform well and has better prediction capability than the traditional methods.

Keywords: BART, Bayesian, predict, stock

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Authors: Erwin San Juan Martinez, Miguel Angel Aguilar Mendez, Manuel Sandoval Villa, Libia Iris Trejo Tellez

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Some nanomaterials may improve the vegetal growth in certain concentration intervals, and could be used as nanofertilizers in order to increase crops yield, and decreasing the environmental pollution due to non-controlled use of conventional fertilizers, therefore the present investigation’s objective was to synthetize and characterize gelatin nanoparticles loaded with calcium generated through pulverization technique and be used as nanofertilizers. To obtain these materials, a fractional factorial design 27-4 was used in order to evaluate the largest number of factors (concentration of Ca2+, temperature and agitation time of the solution and calcium concentration, drying temperature, and % spray) with a possible effect on the size, distribution and morphology of nanoparticles. For the formation of nanoparticles, a Nano Spray-Dryer B - 90® (Buchi, Flawil, Switzerland), equipped with a spray cap of 4 µm was used. Size and morphology of the obtained nanoparticles were evaluated using a scanning electron microscope (JOEL JSM-6390LV model; Tokyo, Japan) equipped with an energy dispersive x-ray X (EDS) detector. The total quantification of Ca2+ as well as its release by the nanoparticles was carried out in an equipment of induction atomic emission spectroscopy coupled plasma (ICP-ES 725, Agilent, Mulgrave, Australia). Of the seven factors evaluated, only the concentration of fertilizer, % spray and concentration of polymer presented a statistically significant effect on particle size. Micrographs of SEM from six of the eight conditions evaluated in this research showed particles separated and with a good degree of sphericity, while in the other two particles had amorphous morphology and aggregation. In all treatments, most of the particles showed smooth surfaces. The average size of smallest particle obtained was 492 nm, while EDS results showed an even distribution of Ca2+ in the polymer matrix. The largest concentration of Ca2+ in ICP was 10.5%, which agrees with the theoretical value calculated, while the release kinetics showed an upward trend within 24 h. Using the technique employed in this research, it was possible to obtain nanoparticles loaded with calcium, of good size, sphericity and with release controlled properties. The characteristics of nanoparticles resulted from manipulation of the conditions of synthesis which allow control of the size and shape of the particles, and provides the means to adapt the properties of the materials to an specific application.

Keywords: calcium, controlled release, gelatin, nano spraydryer, nanofertilizer

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Authors: Pravina Gurjar, Bothiraja Pour, Vijay Kumbhar, Ganesh Dama

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Andrographolide (AG), a bioactive phytoconstituent, has a wider range of pharmacological action. However, due to the intestinal degradation, shows low oral bioavailability. The aim of the present work was to develop Floating In-situ gelling Gastro retentive System (FISGS) for AG in order to enhance its site specific absorption and minimize pH dependent hydrolysis in alkaline environment. Further to increase its therapeutic efficacy for peptic ulcer disease caused by H. pyroli. Gellan based floating in situ gelling system of AG were prepared by using sodium citrate and calcium carbonate. The 32 factorial designs was used to study the effect of gellan and calcium carbonate concentration (independent variables) on dependent variable such as viscosity, floating lag time and drug release. Developed system was evaluated for drug content, floating lag time, viscosity, and drug release studies. Drug content, viscosity, and floating lag time was found to be 81-99%, 67-117 Cps, and 3-5 sec, respectively. The obtained system showed good in vitro floating ability for more than 12 h using 0.1 N HCl as dissolution medium with initial burst release followed by the controlled zero order drug release up to 24 hrs. In vivo testing of FISGS of AG to rats demonstrated significant antiulcer activity that were evaluated by various parameters like pH, volume, total acidity, millimole equivalent of H+ ions/30 min, and protein content of gastric content. The densities of all the formulation batches were found to be near about 0.9 and floating duration above 12 hr. It was observed that with the increase in conc. of gellan there was increase in the viscosity of formulation but all formulations were in optimum range. The drug content of optimized batch was found to be 99.23. In histopathology study of stomach, the villi at the mucosal surface, the intercellular junction, the intestinal lumen were intact; no destruction of the epithelium, and submucosal gland in formulation treated and control group animals as compared to pure drug AG and standard ranitidine. Gellan-based in situ gastro retentive floating system could be advantageous in terms of increased bioavailability of AG to maintain an effective drug conc. in gastric fluid as well as in serum for longer period of time.

Keywords: andrographolide, floating drug delivery, in situ gelling system, gastroretentive system

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Authors: Sohail Ahmed, Ke Xing

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This research theoretically explored the evolution mechanism of enterprise technological innovation capability system (ETICS) from the perspective of complex adaptive systems (CAS). Starting from CAS theory, this study proposed an analytical framework for ETICS, its concepts and theory by integrating CAS methodology into the management of technological innovation capability of enterprises and discusses how to use the principles of complexity to analyze the composition, evolution and realization of the technological innovation capabilities in complex dynamic environment. This paper introduces the concept and interaction of multi-agent, the theoretical background of CAS and summarizes the sources of technological innovation, the elements of each subject and the main clusters of adaptive interactions and innovation activities. The concept of multi-agents is applied through the linkages of enterprises, research institutions and government agencies with the leading enterprises in industrial settings. The study was exploratory based on CAS theory. Theoretical model is built by considering technological and innovation literature from foundational to state of the art projects of technological enterprises. On this basis, the theoretical model is developed to measure the evolution mechanism of enterprise technological innovation capability system. This paper concludes that the main characteristics for evolution in technological systems are based on enterprise’s research and development personal, investments in technological processes and innovation resources are responsible for the evolution of enterprise technological innovation performance. The research specifically enriched the application process of technological innovation in institutional networks related to enterprises.

Keywords: complex adaptive system, echo model, enterprise knowledge system, research institutions, multi-agents.

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Authors: K. Yu Vlasova, M. A. Abakumov, H. Wishwarsao, M. Sokolsky, N. V. Nukolova, A. G. Majouga, Y. I. Golovin, N. L. Klyachko, A. V. Kabanov

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Introduction:Nowadays pharmaceutical medicine is aimed to create systems for combined therapy, diagnostic, drug delivery and controlled release of active molecules to target cells. Magnetic nanoparticles (MNPs) are used to achieve this aim. MNPs can be applied in molecular diagnostics, magnetic resonance imaging (T1/T2 contrast agents), drug delivery, hyperthermia and could improve therapeutic effect of drugs. The most common drug containers, containing MNPs, are liposomes, micelles and polymeric molecules bonded to the MNPs surface. Usually superparamagnetic nanoparticles are used (the general diameter is about 5-6 nm) and all effects of high frequency magnetic field (MF) application are based on Neel relaxation resulting in heating of surrounded media. In this work we try to develop a new method to improve drug release from MNPs under super low frequency MF. We suppose that under low frequency MF exposures the Brown’s relaxation dominates and MNPs rotation could occur leading to conformation changes and release of bioactive molecules immobilized on MNPs surface.The aim of this work was to synthesize different systems with active drug (biopolymers coated MNPs nanoclusters with immobilized enzymes and doxorubicin (Dox) loaded magnetic liposomes/micelles) and investigate the effect of super low frequency MF on these drug containers. Methods: We have synthesized MNPs of magnetite with magnetic core diameter 7-12 nm . The MNPs were coated with block-copolymer of polylysine and polyethylene glycol. Superoxide dismutase 1 (SOD1) was electrostatically adsorbed on the surface of the clusters. Liposomes were prepared as follow: MNPs, phosphatidylcholine and cholesterol were dispersed in chloroform, dried to get film and then dispersed in distillated water, sonicated. Dox was added to the solution, pH was adjusted to 7.4 and excess of drug was removed by centrifugation through 3 kDa filters. Results: Polylysine coated MNPs formed nanosized clusters (as observed by TEM) with intensity average diameter of 112±5 nm and zeta potential 12±3 mV. After low frequency AC MF exposure we observed change of immobilized enzyme activity and hydrodynamic size of clusters. We suppose that the biomolecules (enzymes) are released from the MNPs surface followed with additional aggregation of complexes at the MF in medium. Centrifugation of the nanosuspension after AC MF exposures resulted in increase of positive charge of clusters and change in enzyme concentration in comparison with control sample without MF, thus confirming desorption of negatively charged enzyme from the positively charged surface of MNPs. Dox loaded magnetic liposomes had average diameter of 160±8 nm and polydispersity index (PDI) 0.25±0.07. Liposomes were stable in DW and PBS at pH=7.4 at 370C during a week. After MF application (10 min of exposure, 50 Hz, 230 mT) diameter of liposomes raised to 190±10 nm and PDI was 0.38±0.05. We explain this by destroying and/or reorganization of lipid bilayer, that leads to changes in release of drug in comparison with control without MF exposure. Conclusion: A new application of low frequency AC MF for drug delivery and controlled drug release was shown. Investigation was supported by RSF-14-13-00731 grant, K1-2014-022 grant.

Keywords: magnetic nanoparticles, low frequency magnetic field, drug delivery, controlled drug release

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Authors: Chuanxiang Cheng, Tiantian Min, Jin Yue

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Antimicrobial active packaging enables extensive biological effects to improve food safety. However, the efficacy of antimicrobial packaging hinges on factors including the diffusion rate of the active agent toward the food surface, the initial content in the antimicrobial agent, and the targeted food shelf life. Among the possibilities of antimicrobial packaging design, an interesting approach involves the incorporation of volatile antimicrobial agents into the packaging material. In this case, the necessity for direct contact between the active packaging material and the food surface is mitigated, as the antimicrobial agent exerts its action through the packaging headspace atmosphere towards the food surface. However, it still remains difficult to achieve controlled and precise release of bioactive compounds to the specific target location with required quantity in food packaging applications. Remarkably, the development of stimuli-responsive materials for electrospinning has introduced the possibility of achieving controlled release of active agents under specific conditions, thereby yielding enduring biological effects. Relative humidity (RH) for the storage of food categories such as meat and aquatic products typically exceeds 90%. Consequently, high RH can be used as an abiotic trigger for the release of active agents to prevent microbial growth. Hence, a novel RH - responsive polyvinyl alcohol/chitosan (PVA/CS) composite nanofibrous film incorporated with 4-terpineol/β-cyclodextrin inclusion complexes (4-TA@β-CD ICs) was engineered by electrospinning that can be deposited as a functional packaging materials. The characterization results showed the thermal stability of the films was enhanced after the incorporation due to the hydrogen bonds between ICs and polymers. Remarkably, the 4 wt% 4-TA@β-CD ICs/PVA/CS film exhibited enhanced crystallinity, moderate hydrophilic (Water contact angle of 81.53°), light barrier property (Transparency of 1.96%) and water resistance (Water vapor permeability of 3.17 g mm/m2 h kPa). Moreover, this film also showed optimized mechanical performance with a Young’s modulus of 11.33 MPa, a tensile strength of 19.99 MPa and an elongation at break of 4.44 %. Notably, the antioxidant and antibacterial properties of this packaging material were significantly improved. The film demonstrated the half-inhibitory concentrations (IC50) values of 87.74% and 85.11% for scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2, 2′-azinobis (3-ethylbenzothiazoline-6-sulfonic) (ABTS) free radicals, respectively, in addition to an inhibition efficiency of 65% against Shewanella putrefaciens, the characteristic bacteria in aquatic products. Most importantly, the film achieved controlled release of 4-TA under high 98% RH by inducing the plasticization of polymers caused by water molecules, swelling of polymer chains, and destruction of hydrogen bonds within the cyclodextrin inclusion complex. Consequently, low relative humidity is suitable for the preservation of nanofibrous film, while high humidity conditions typical in fresh food packaging environments effectively stimulated the release of active compounds in the film. This film with a long-term antimicrobial effect successfully extended the shelf life of Litopenaeus vannamei shrimp to 7 days at 4 °C. This attractive design could pave the way for the development of new food packaging materials.

Keywords: controlled release, electrospinning, nanofibrous film, relative humidity–responsive, shrimp preservation

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Authors: David Polcari, Samuel C. Perry, Loredano Pollegioni, Matthias Geissler, Janine Mauzeroll

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ᴅ-serine acts as an endogenous co-agonist for N-methyl-ᴅ-aspartate receptors in neuronal synapses. This makes it a key component in the development and function of a healthy brain, especially given its role in several neurodegenerative diseases such as Alzheimer’s disease and dementia. Despite such clear research motivations, the primary site and mechanism of ᴅ-serine release is still currently unclear. For this reason, we are developing a biosensor for the detection of ᴅ-serine utilizing a microelectrode in combination with a ᴅ-amino acid oxidase enzyme, which produces stoichiometric quantities of hydrogen peroxide in response to ᴅ-serine. For the fabrication of a biosensor with good selectivity, we use a permselective poly(meta-phenylenediamine) film to ensure only the target molecule is reacted, according to the size exclusion principle. In this work, we investigated the effect of the electrodeposition conditions used on the biosensor’s response time and selectivity. Careful optimization of the fabrication process allowed for enhanced biosensor response time. This allowed for the real time sensing of ᴅ-serine in a bulk solution, and also provided in means to map the efflux of ᴅ-serine in real time. This was done using scanning electrochemical microscopy (SECM) with the optimized biosensor to measure localized release of ᴅ-serine from an agar filled glass capillary sealed in an epoxy puck, which acted as a model system. The SECM area scan simultaneously provided information regarding the rate of ᴅ-serine flux from the model substrate, as well as the size of the substrate itself. This SECM methodology, which provides high spatial and temporal resolution, could be useful to investigate the primary site and mechanism of ᴅ-serine release in other biological samples.

Keywords: ᴅ-serine, enzymatic biosensor, microelectrode, scanning electrochemical microscopy

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Authors: Abhay Asthana, Shally Toshkhani, Gyati Shilakari

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The present research was aimed to develop a biodegradable dermal patch formulation for wound healing in a novel, sustained and systematic manner. The goal is to reduce the frequency of dressings with improved drug delivery and thereby enhance therapeutic performance. In present study optimized formulation was designed using component polymers and excipients (e.g. Hydroxypropyl methyl cellulose, Ethylcellulose, and Gelatin) to impart significant folding endurance, elasticity and strength. Gelatin was used to get a mixture using ethylene glycol. Chitosan dissolved in suitable medium was mixed with stirring to gelatin mixture. With continued stirring to the mixture Curcumin was added in optimized ratio to get homogeneous dispersion. Polymers were dispersed with stirring in final formulation. The mixture was sonicated casted to get the film form. All steps were carried out under under strict aseptic conditions. The final formulation was a thin uniformly smooth textured film with dark brown-yellow color. The film was found to have folding endurance was around 20 to 21 times without a crack in an optimized formulation at RT (23C). The drug content was in range 96 to 102% and it passed the content uniform test. The final moisture content of the optimized formulation film was NMT 9.0%. The films passed stability study conducted at refrigerated conditions (4±0.2C) and at room temperature (23 ± 2C) for 30 days. Further, the drug content and texture remained undisturbed with stability study conducted at RT 23±2C for 45 and 90 days. Percentage cumulative drug release was found to be 80% in 12 h and matched the biodegradation rate as drug release with correlation factor R2 > 0.9. The film based formulation developed shows promising results in terms of stability and release profiles.

Keywords: biodegradable, patch, bioactive, polymer

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Authors: Jalil Badamfirooz

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Soil wind erosion has a negative impact on the environment. Mulching is one of the most efficient soil protection techniques. Bitumen emulsion has recently been utilized as a soil cover that is sprayed directly over the soil and forms a thin film. The thin coating of bitumen emulsion prevents soil erosion and keeps moisture in the soil. Besides, some compounds release into the soil and cause environmental problems. In the present study, the effect of bitumen emulsion on the release of polycyclic aromatic hydrocarbons (PAHs) into the soil is studied in an arid land located in the central part of Iran. The soil was Loamy-Sand and saline with a pH of 8.03. Bitumen emulsion was used in this study as mulch at a rate of 4 L m2. The effect of this mulch on soil properties was investigated after 6 months of mulch application. Then PAHs concentrations were determined in samples collected from different depths in bitumen emulsion sprayed and control soils. In general, bitumen emulsion application on soil led to a significant increase in some PAHs, which was higher than soil pollution standards critical level of pollution for commerce, groundwater protection, pasture forest, and park and residence uses.

Keywords: mulch, bitumen emulsion, arid land, PAH

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Authors: Ming Chian Yew, Ming Kun Yew, Lip Huat Saw, Tan Ching Ng, Rajkumar Durairaj, Jing Han Beh

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This paper analyzes the fire protection performance, char formation and heat release characteristics of the thin film intumescent coatings that incorporate waste eggshell (ES) as a nano bio-filler. In this study, the Bunsen burner and the fire propagation (BS 476: Part 6) tests of coatings were measured. Experiments on the samples were also tested to evaluate their fire behavior using a cone calorimeter according to ISO 5660-1 specifications. On exposure, the samples B, C and D had been certified to be Class 0 due to the fire propagation indexes of the samples were less than 12. Samples B and D showed a significant reduction in total heat rate (B=11.6 MJ/m² and D=12.0 MJ/m²) and uniform char structures with the addition of 3.30 wt.% and 2.75 wt.% ES nano bio-filler, respectively. As a result, ES nano bio-filler composition good to slow down the fire expanding and demonstrate better fire protection due to its positive synergistic effect with flame retardant ingredients on physical and chemical reactions in fire protection.

Keywords: cone calorimeter, eggshell, fire protection, heat release rate, intumescent coating

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Authors: Prakriti Diwan, S. Saraf

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The present study involves preparation and evaluation of microparticles of diclofenac sodium. The microparticles were prepared by the emulsion solvent evaporation techniques using ethylcellulose polymer. Four different batches of microspheres were prepared by varying the concentration of polymer from 50% to 80% w/w. The microspheres were characterized for drug content, percentage yield and encapsulation efficiency, particle size analysis and surface morphology. Microsphere prepared with high drug content produces higher percentage yield and encapsulation efficiency values. It was observed the increase in concentration of the polymer, increases the mean particle size of the microspheres. The effect of polymer concentration on the in vitro release of diclofenac from the microspheres was also studied. The production microparticles yield showed 98.74%, mean particle size 956.32µm and loading efficiency 97.15%. The results were found that microparticles prepared had slower release than microparticles (p>0.05). Therefore, it may be concluded that drug loaded microparticles are suitable delivery systems for diclofenac sodium.

Keywords: diclofenac sodium, emulsion solvent evaporation, ethylcellulose, microparticles

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Authors: Deepak Kumar, Debasish Deb, Reena Mamgain

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Radar signal processing requires high number crunching capability. Most often this is achieved using multiprocessor platform. Though multiprocessor platform provides the capability of meeting the real time computational challenges, the architecture of the same along with mapping of the algorithm on the architecture plays a vital role in efficiently using the platform. Towards this, along with standard performance metrics, few additional metrics are defined which helps in evaluating the multiprocessor platform along with the algorithm mapping. A generic multiprocessor architecture can not suit all the processing requirements. Depending on the system requirement and type of algorithms used, the most suitable architecture for the given problem is decided. In the paper, we study different architectures and quantify the different performance metrics which enables comparison of different architectures for their merit. We also carried out case study of different architectures and their efficiency depending on parallelism exploited on algorithm or data or both.

Keywords: radar signal processing, multiprocessor architecture, efficiency, load imbalance, buffer requirement, pipeline, parallel, hybrid, cluster of processors (COPs)

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Authors: Jude Inwumoh, Adam P. R. Taylor, Kosala Gunawardane

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Modular multilevel converters (MMC) exhibit a highly scalable and modular characteristic with good voltage/power expansion, fault tolerance capability, low output harmonic content, good redundancy, and a flexible front-end configuration. Fault detection, location, and isolation, as well as maintaining fault ride-through (FRT), are major challenges to MMC reliability and power supply sustainability. Different papers have been reviewed to seek the best MMC configuration with fault capability. DC faults are the most common fault, while the probability that AC fault occurs in a modular multilevel converter (MCC) is low; though, AC faults consequence are severe. This paper reviews several MMC topologies and modulation techniques in tackling faults. These fault control strategies are compared based on cost, complexity, controllability, and power loss. A meshed network of half-bridge (HB) MMC topology was optimal in rendering fault ride through than any other MMC topologies but only when combined with DC circuit breakers (CBS), AC CBS, and fault current limiters (FCL).

Keywords: MMC-HVDC, DC faults, fault current limiters, control scheme

Procedia PDF Downloads 129

Authors: Kotchamon Yodkhum, Thawatchai Phaechamud

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Hydrophobic chitosan-based materials have been developed as controlled drug delivery system. This study was aimed to prepare and evaluate chitosan-aluminum monostearate composite dispersion (CLA) as fabricating liquid for construct a hydrophobic, controlled-release solid drug delivery matrix. This work was attempted to blend hydrophobic substance, aluminum monostearate (AMS), with chitosan in acidic aqueous medium without using any surfactants or grafting reaction, and high temperature during mixing that are normally performed when preparing hydrophobic chitosan system. Lactic acid solution (2%w/v) was employed as chitosan solvent. CLA dispersion was prepared by dispersing different amounts of AMS (1-20% w/w) in chitosan solution (4% w/w) with continuous agitation using magnetic stirrer for 24 h. Effect of AMS amount on physicochemical properties of the dispersion such as viscosity, rheology and particle size was evaluated. Morphology of chitosan-AMS complex (dispersant) was observed under inverted microscope and atomic force microscope. Stability of CLA dispersions was evaluated after preparation within 48 h. CLA dispersions containing AMS less than 5 % w/w exhibited rheological behavior as Newtonian while that containing higher AMS amount exhibited as pseudoplastic. Particle size of the dispersant was significantly smaller when AMS amount was increased up to 5% w/w and was not different between the higher AMS amount system. Morphology of the dispersant under inverted microscope displayed irregular shape and their size exhibited the same trend with particle size measurement. Observation of the dispersion stability revealed that phase separation occurred faster in the system containing higher AMS amount which indicated lower stability of the system. However, the dispersions were homogeneous and stable more than 12 hours after preparation that enough for fabrication process. The prepared dispersions had ability to be fabricated as a porous matrix via lyophilization technique.

Keywords: chitosan, aluminum monostearate, dispersion, controlled-release

Procedia PDF Downloads 380

Authors: Malek Y. S. Ibrahim, Jeffrey A. Bennett, Milad Abolhasani

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Despite the potential of hydrogen (H2) storage in liquid organic carriers to achieve carbon neutrality, the energy required for H2 release and the cost of catalyst recycling has hindered its large-scale adoption. In response, a photo flow reactor packed with rhodium (Rh)/titania (TiO2) photocatalyst was reported for the continuous and selective acceptorless dehydrogenation of 1,2,3,4-tetrahydroquinoline to H2 gas and quinoline under visible light irradiation at room temperature. The tradeoff between the reactor pressure drop and its photocatalytic surface area was resolved by selective in-situ photodeposition of Rh in the photo flow reactor post-packing on the outer surface of the TiO2 microparticles available to photon flux, thereby reducing the optimal Rh loading by 10 times compared to a batch reactor, while facilitating catalyst reuse and regeneration. An example of using quinoline as a hydrogen acceptor to lower the energy of the hydrogen production step was demonstrated via the water-gas shift reaction.

Keywords: hydrogen storage, flow chemistry, photocatalysis, solar hydrogen

Procedia PDF Downloads 88

Authors: Rachmat Mauludin, Novita R. Kusuma, Diky Mudhakir

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Famotidine (FMT) is one of used substances in the treatment of hiperacidity and peptic ulcer, administered orally and parenterally via intravenous injection. Oral administration, which is more favorable, has been reported to have many obstacles in the process of the treatment, includes decreasing the bioavailability of FMT. This research was aimed to prepare FMT in form of solid lipid nanoparticles (SLN) with size ranging between 100-200 nm. The research was carried out also by optimizing factors that may affect physical stability of SLN. Formulation of Famotidine SLN was carried out by optimizing factors, such as duration of homogenization and sonication, lipid concentration, stabilizer composition and stabilizer concentration. SLN physical stability was evaluated (particle size distribution) for 42 days in 3 diferent temperatures. Entrapment efficiency and drug loading was determined indirectly and directly. The morphology of SLN was visualized by transmission electron microscope (TEM). In vitro release study of FMT was conducted in 2 mediums, at pH of 1.2 and 7.4. Chemical stability of FMT was determined by quantifying the concentration of FMT within 42 days. Famotidin SLN consisted of GMS as lipid and poloxamer 188, lecithin, and polysorbate 80 as stabilizers. Homogenization and sonication was performed for 5 minutes and 10 minutes. Physyical stability of nanoparticles at 3 different temperatures was no significant difference. The best formula was physically stable until 42 days with mean particle size below 200 nm. Nanoparticles produced was able to entrap FMT until 86.6%. Evaluation by TEM showed that nanoparticles was spherical and solid. In medium pH of 1.2, FMT was released only 30% during 4 hour. On the other hand, within 4 hours SLN could release FMT completely in medium pH of 7.4. The FMT concentration in nanoparticles dispersion was maintained until 95% in 42 days (40oC, RH 75%). Famotidine SLN was able to be produced with mean particle size ranging between 100-200 nm and physically stable for 42 days. SLN could be loaded by 86,6% of FMT. Morphologically, obtained SLN was spheric and solid. During 4 hours in medium pH of 1.2 and 7.4, FMT was released until 30% and 100%, respectively.

Keywords: solid lipid nanoparticle (SLN), famotidine (FMT), physicochemical properties, release study

Procedia PDF Downloads 354

Authors: Somdech Rungsrisawas

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The objectives of this study are to examine the relationship between the competitive advantage of small and medium enterprises (SMEs) and their overall performance. A mixed method has been applied to identify the effect of determinants toward competitive advantage. The sample is composed of SMEs in product and service businesses. The study has been tested at an organizational level with samples of SME entrepreneurs, business successors, and board of directors or management team. Quantitative analysis has been conducted through multiple regression analysis with 400 samples. The findings illustrate that each aspect of competitive advantage needs a different set of driving factors to explain either the direct or the indirect effect on firm performance. Interestingly, technological capability is a perfect mediator and interorganizational cooperation toward competitive advantage. In addition, differentiation is difficult to be perceived by customers, as well as difficult to manage; however, it is considered important to develop an SMEs product or service for firm sustainably.

Keywords: competitive advantage, firm performance, technological capability, Small and Medium Enterprise (SMEs)

Procedia PDF Downloads 284

Authors: K. N. Umesh

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Wood Polymer Composites (WPC) were synthesized artificially by combining polypropylene, wood and resin. It is difficult to obtain a good surface finish by conventional machining on WPC because of material degradation due to excessive heat generated during the process. In order to preserve the material property and deliver a better surface finish and accuracy, a proper solution is devised for the machining of wood composites at low temperature. This research focuses on studying the effects of parameters of cryogenic machining on sawdust incorporated polypropylene composite material, in view of evolving the most suitable composition and an appropriate combination of process parameters. The machining characteristics of the six different compositions of WPC were evaluated by analyzing the trend. An attempt is made to determine proper combinations material composition and process control parameters, through process capability studies. A WPC of 80%-wood (saw dust particles), 20%-polypropylene and 0%-resin was found to be the best alternative for obtaining the best surface finish under cryogenic machining conditions.

Keywords: Cryogenic Machining, Process Capability, Surface Finish, Wood Polymer Composites

Procedia PDF Downloads 242

Authors: Mahboubeh Kabiri, Saba Aslani

Abstract:

Among various approaches used for the treatment of cardiovascular diseases, the occlusion of the small-diameter vascular graft (SDVG) is still an unresolved problem which seeks further research to address them. Though autografts are now the gold standards to be replaced for blocked coronary arteries, they suffer from inadequate quality and quantity. On the other hand, the major problems of the tissue engineered grafts are thrombosis and intimal hyperplasia. Provision of a suitable spatiotemporal release pattern of anticoagulant agents such as heparin and aspirin can be a step forward to overcome such issues . Herein, we fabricated electrospun scaffolds from FDA (Food and Drug Administration) approved poly-L-lactic acid (PLLA) with aspirin loaded into the nanofibers. Also, we surface coated the scaffolds with Amniotic Membrane lysate as a source for natural elastic polymers and a mimic of endothelial basement membrane. The scaffolds were characterized thoroughly structurally and mechanically for their morphology, fiber orientation, tensile strength, hydrophilicity, cytotoxicity, aspirin release and cell attachment support. According to the scanning electron microscopy (SEM) images, the size of fibers ranged from 250 to 500 nm. The scaffolds showed appropriate tensile strength expected for vascular grafts. Cellular attachment, growth, and infiltration were proved using SEM and MTT (3-(4,5-Dimethylthiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide) assay. Drug-loaded scaffolds showed a sustained release profile of aspirin in 7 days. An enhanced cytocompatibility was observed in AM-coated electrospun PLLA fibers compared to uncoated scaffolds. Our results together indicated that AM lysate coated ASA releasing scaffolds have promising potentials for development of a biocompatible SDVG.

Keywords: vascular tissue engineering, vascular grafts, anticoagulant agent, aspirin, amniotic membrane

Procedia PDF Downloads 153