Extended Abstract Gold nanoparticles are widely used in many fields, especially in analytical chemistry, medicine and engineering. In the literature, many methods provide easy and reproducible ways to synthesize these nanoparticles with different sizes and forms [1]. However, narrowing the size distribution is still a challenge, particularly in aqueous methods of synthesis. Ideally, it is desirable to have uniform nanoparticles; however, the nucleation and growth mechanism tend to produce a broad size distribution. For large particles, some authors propose controlling size by a kinetical seed-growth approach, but the challenge remains in the synthesis of the initial uniform seeds [2,3]. The present work focuses on the synthesis of ultrauniform gold nanoparticles by a combined strategy of a modified Turkevich method and filtration step. The results showed that the synthesis follows a complex mechanism where the ratio between the gold (III) and sodium citrate, and the pH play a major role in the final size distribution. The synthesized ultra-narrow size distribution was achieved by adjusting the pH of the solvent between 7.5 and 8. The results were confirmed by High-Resolution Transmission Electron microscopy (HRTEM) images, spectrophotometry (UV-Vis), and Dynamic Light Scattering (DLS). The synthetized nanoparticles have an average diameter of 15 nm and 26 nm by HRTEM and DLS, respectively. The average polydispersity index was <0.05 giving a strong evidence of the monodisperse nature of the synthesized nanoparticles. In addition, we study the particle stability with different capping agents and conditions such as temperature, salt concentration, and storage time. The Nanoparticles were stable at temperatures lower than 40oC and only a small change in size was observed at higher temperatures. Molecules with thiol groups such as 11-mercaptoundecanoic acid increased the nanoparticle stability with the salt concentration. However, it was less effective in preserving the nanoparticle size and polydispersity with the storage time. With the proper capping agent (polyethylene glycol and citrate), the nanoparticles were stored without any change in the homogeneous size distribution for at least one month.
{"title":"Synthesis of Ultra-Homogeneous Gold Nanoparticles","authors":"E. Méndez, S. Botasini","doi":"10.11159/ICNFA19.152","DOIUrl":"https://doi.org/10.11159/ICNFA19.152","url":null,"abstract":"Extended Abstract Gold nanoparticles are widely used in many fields, especially in analytical chemistry, medicine and engineering. In the literature, many methods provide easy and reproducible ways to synthesize these nanoparticles with different sizes and forms [1]. However, narrowing the size distribution is still a challenge, particularly in aqueous methods of synthesis. Ideally, it is desirable to have uniform nanoparticles; however, the nucleation and growth mechanism tend to produce a broad size distribution. For large particles, some authors propose controlling size by a kinetical seed-growth approach, but the challenge remains in the synthesis of the initial uniform seeds [2,3]. The present work focuses on the synthesis of ultrauniform gold nanoparticles by a combined strategy of a modified Turkevich method and filtration step. The results showed that the synthesis follows a complex mechanism where the ratio between the gold (III) and sodium citrate, and the pH play a major role in the final size distribution. The synthesized ultra-narrow size distribution was achieved by adjusting the pH of the solvent between 7.5 and 8. The results were confirmed by High-Resolution Transmission Electron microscopy (HRTEM) images, spectrophotometry (UV-Vis), and Dynamic Light Scattering (DLS). The synthetized nanoparticles have an average diameter of 15 nm and 26 nm by HRTEM and DLS, respectively. The average polydispersity index was <0.05 giving a strong evidence of the monodisperse nature of the synthesized nanoparticles. In addition, we study the particle stability with different capping agents and conditions such as temperature, salt concentration, and storage time. The Nanoparticles were stable at temperatures lower than 40oC and only a small change in size was observed at higher temperatures. Molecules with thiol groups such as 11-mercaptoundecanoic acid increased the nanoparticle stability with the salt concentration. However, it was less effective in preserving the nanoparticle size and polydispersity with the storage time. With the proper capping agent (polyethylene glycol and citrate), the nanoparticles were stored without any change in the homogeneous size distribution for at least one month.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123494459","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract As an important part of the knee joint, the meniscus plays a role in transmitting load, absorbing oscillation, and improving joint stability [1]. However, joint disease, degeneration, trauma and other causes may cause damage to the meniscus. Meniscus transplantation can solve diseases such as osteoarthritis caused by meniscus loss, but there are some problems such as limited stent replacement, immune response, and structural mismatch [2, 3]. There is currently a problem of mismatch in mechanical properties between commercial meniscus implants and natural meniscus, which is not conducive to long-term implantation [4]. Therefore, a porous polycarbonate-polyurethane meniscus implant based on a very small threeperiod surface is proposed. First, a 3D model of the knee joint was established based on the CT scan results of the knee joint [5]. The porous element is constructed by Primitive minimal surface. After Boolean operation with the outer meniscus structure, a series of implant structures with different pore sizes or porosity are obtained by adjusting the surface construction parameters. Then, finite element simulation was performed to compare the mechanical changes of articular cartilage and bilateral meniscus in the knee joint of the natural meniscus and the designed porous meniscus. The results show that the use of a porous meniscal implant can effectively reduce the compressive stress and shear stress concentration on the femoral cartilage and the tibial cartilage. At the same time, changes in the structural parameters of the porous implant affect the stress of the articular cartilage. In addition to having good mechanical properties, the structure can also be rapidly formed by three-dimensional printing technology, which provides a new idea for clinical application.
{"title":"Structure Modeling and Mechanical Analyses of Meniscal Implants Based on Triply Periodic Minimal Surfaces","authors":"Shi Jianping, Zhu Liya, Yang Ji-quan","doi":"10.11159/ICBB19.123","DOIUrl":"https://doi.org/10.11159/ICBB19.123","url":null,"abstract":"Extended Abstract As an important part of the knee joint, the meniscus plays a role in transmitting load, absorbing oscillation, and improving joint stability [1]. However, joint disease, degeneration, trauma and other causes may cause damage to the meniscus. Meniscus transplantation can solve diseases such as osteoarthritis caused by meniscus loss, but there are some problems such as limited stent replacement, immune response, and structural mismatch [2, 3]. There is currently a problem of mismatch in mechanical properties between commercial meniscus implants and natural meniscus, which is not conducive to long-term implantation [4]. Therefore, a porous polycarbonate-polyurethane meniscus implant based on a very small threeperiod surface is proposed. First, a 3D model of the knee joint was established based on the CT scan results of the knee joint [5]. The porous element is constructed by Primitive minimal surface. After Boolean operation with the outer meniscus structure, a series of implant structures with different pore sizes or porosity are obtained by adjusting the surface construction parameters. Then, finite element simulation was performed to compare the mechanical changes of articular cartilage and bilateral meniscus in the knee joint of the natural meniscus and the designed porous meniscus. The results show that the use of a porous meniscal implant can effectively reduce the compressive stress and shear stress concentration on the femoral cartilage and the tibial cartilage. At the same time, changes in the structural parameters of the porous implant affect the stress of the articular cartilage. In addition to having good mechanical properties, the structure can also be rapidly formed by three-dimensional printing technology, which provides a new idea for clinical application.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123973520","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The evaluation of room acoustics characteristics in rooms has been thoroughly described in several papers since the 60-is. Moreover, the ISO 3382 standard describes several acoustic parameters and their measurements. However, there is only a few information about the methods of pre-processing the impulse responses that are required before calculating those acoustic parameters. If the final goal of measuring the acoustical behaviour of a room is to compare it to others or to create databases, reliable and comparable data must be obtained, no matter the way they have been measured. At the Engineering Department of the University of Bologna, several tests, with the same starting data set, have been performed to compare the results given by the most commonly used PC applications, in order to identify and quantify any possible incongruity. In this paper, the main processing methods (based on Lundeby, Chu) are analysed. Moreover, they are compared with the Schroeder (backward integration) methods. In a further step, these methods are applied in some acoustic measurements employed in some opera
{"title":"The Measurements of Physical Parameter on Room Acoustics: Considerations about Variability","authors":"V. Vodola","doi":"10.11159/ICEPR19.180","DOIUrl":"https://doi.org/10.11159/ICEPR19.180","url":null,"abstract":"The evaluation of room acoustics characteristics in rooms has been thoroughly described in several papers since the 60-is. Moreover, the ISO 3382 standard describes several acoustic parameters and their measurements. However, there is only a few information about the methods of pre-processing the impulse responses that are required before calculating those acoustic parameters. If the final goal of measuring the acoustical behaviour of a room is to compare it to others or to create databases, reliable and comparable data must be obtained, no matter the way they have been measured. At the Engineering Department of the University of Bologna, several tests, with the same starting data set, have been performed to compare the results given by the most commonly used PC applications, in order to identify and quantify any possible incongruity. In this paper, the main processing methods (based on Lundeby, Chu) are analysed. Moreover, they are compared with the Schroeder (backward integration) methods. In a further step, these methods are applied in some acoustic measurements employed in some opera","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130109724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This work aims to bridge nanotechnology and biotechnology via comparative study of the influence of functionalized multi-walled carbon nanotubes (fMWCNTs) on some enzymes activity and structure by either covalent binding or adsorption techniques such as L-asparaginase (produced by Aspergillus versicolor, L-ASNase). The prepared materials were analyzed by scanning and transmission electron microscopes (SEM and TEM) and particle size distribution analysis using DLS technique. Besides, in vitro cytotoxicity of the prepared materials using SRB assay was carried out. The highest immobilization yield (%) of L-ASNase was about 54 % and the immobilized MWCNTs had particle size around 5179 nm relative to the un-immobilized one (180 nm). Using of fMWCNTs for enzyme immobilization could be protecting the effect of elevating temperature at different period of time. Also, the storage time played a significant role in activation of the immobilized enzyme by releasing the embedded enzyme from fMWCNTs.
{"title":"Functionalized Multi-walled Carbon Nanotubes as Emerging Carrier for Biological Applications","authors":"A. haroun, H. Mostafa, E. Ahmed","doi":"10.11159/ICNFA19.106","DOIUrl":"https://doi.org/10.11159/ICNFA19.106","url":null,"abstract":"This work aims to bridge nanotechnology and biotechnology via comparative study of the influence of functionalized multi-walled carbon nanotubes (fMWCNTs) on some enzymes activity and structure by either covalent binding or adsorption techniques such as L-asparaginase (produced by Aspergillus versicolor, L-ASNase). The prepared materials were analyzed by scanning and transmission electron microscopes (SEM and TEM) and particle size distribution analysis using DLS technique. Besides, in vitro cytotoxicity of the prepared materials using SRB assay was carried out. The highest immobilization yield (%) of L-ASNase was about 54 % and the immobilized MWCNTs had particle size around 5179 nm relative to the un-immobilized one (180 nm). Using of fMWCNTs for enzyme immobilization could be protecting the effect of elevating temperature at different period of time. Also, the storage time played a significant role in activation of the immobilized enzyme by releasing the embedded enzyme from fMWCNTs.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"150 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116356572","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Radek Jirkovec, T. Kalous, P. Holec, A. Samková, J. Chvojka
Extended Abstract The aim of this work was to develop and test micro / nano fiber material (scaffold) designed for tissue engineering, especially for bone regeneration. In the work the aim was to find a suitable polymeric material to create a suitable structure using alternating current (AC) spinning technology and to test mechanical properties and biocompatibility of scaffolds. For bone regeneration are used scaffolds that are physically chemically, structurally and biologically similar to extracellular matrix. The scaffold properties, such as porosity, affect cell proliferation, differentiation, and bone regeneration itself. For bone regeneration are used both natural and synthetic polymers, such as collagen, gelatin, chitosan, polylactic acid, polycaprolactone, and others. [1, 2, 3, 4] The polycaprolactone, which promotes cellular viability, has been selected from the previous experiments, where we used fibrous layer formed by direct current (DC) spinning. As it mentioned in the introduction, the production of micro / nano fiber scaffolds was carried out using AC spinning technology. It is a high-voltage technology which used, in comparison to DC spinning, a frequency of tens of Hz. The formed fibers are provided with both positive and negative charges. Their interaction creates a neutral fibrous bundle that can form in free space. The alternating voltage allows the formation of nanofibres without the anti-electrode, whereby the nanofibers formed can be deposited on the core core yarn, the rotary cylinder or the static collector. Compared to DC spinning, this method produces a bulky, fluffy layer. [5, 6, 7] The first phase of the experiment was to find a suitable solvent system and concentration of the polymer solution. The experiment was performed with two molecular weights of polycaprolactone: Mn 45,000 and Mn 80,000. Three solvent systems were chosen for the experiment: chloroform:ethanol; chloroform:ethanol:acetic acid; and acetic acid:formic acid:acetone. The experiment led to finding that the solution prepared in the chloroform: ethanol solvent system was unsuitable, spinning was poor. In the second solvent system, the spinning process was good but with low production. The spinning with the last solvent system was optimal and with high production. Therefore, the solvent system acetic acid: formic acid: acetone was chosen for further testing. The second phase of the experiment was aimed at producing of fiber layers with different surface density. The spinning was carried out on a rotating drum, the surface density was controlled by the spinning time. However, an important parameter is the rotation speed of the rotating drum, which affects the stiffness of the resulting layer. Thus, two rotation speeds of the rotating drum were used during the experiment to compare the strengths of the resulting layers. In the last stage of the experiment, for biological testing were spun two fiber layers with selected spinning parameters, where one fiber
{"title":"Nanofibrous Scaffold for Bone Tissue Engineering via AC Electrospinning","authors":"Radek Jirkovec, T. Kalous, P. Holec, A. Samková, J. Chvojka","doi":"10.11159/ICNFA19.124","DOIUrl":"https://doi.org/10.11159/ICNFA19.124","url":null,"abstract":"Extended Abstract The aim of this work was to develop and test micro / nano fiber material (scaffold) designed for tissue engineering, especially for bone regeneration. In the work the aim was to find a suitable polymeric material to create a suitable structure using alternating current (AC) spinning technology and to test mechanical properties and biocompatibility of scaffolds. For bone regeneration are used scaffolds that are physically chemically, structurally and biologically similar to extracellular matrix. The scaffold properties, such as porosity, affect cell proliferation, differentiation, and bone regeneration itself. For bone regeneration are used both natural and synthetic polymers, such as collagen, gelatin, chitosan, polylactic acid, polycaprolactone, and others. [1, 2, 3, 4] The polycaprolactone, which promotes cellular viability, has been selected from the previous experiments, where we used fibrous layer formed by direct current (DC) spinning. As it mentioned in the introduction, the production of micro / nano fiber scaffolds was carried out using AC spinning technology. It is a high-voltage technology which used, in comparison to DC spinning, a frequency of tens of Hz. The formed fibers are provided with both positive and negative charges. Their interaction creates a neutral fibrous bundle that can form in free space. The alternating voltage allows the formation of nanofibres without the anti-electrode, whereby the nanofibers formed can be deposited on the core core yarn, the rotary cylinder or the static collector. Compared to DC spinning, this method produces a bulky, fluffy layer. [5, 6, 7] The first phase of the experiment was to find a suitable solvent system and concentration of the polymer solution. The experiment was performed with two molecular weights of polycaprolactone: Mn 45,000 and Mn 80,000. Three solvent systems were chosen for the experiment: chloroform:ethanol; chloroform:ethanol:acetic acid; and acetic acid:formic acid:acetone. The experiment led to finding that the solution prepared in the chloroform: ethanol solvent system was unsuitable, spinning was poor. In the second solvent system, the spinning process was good but with low production. The spinning with the last solvent system was optimal and with high production. Therefore, the solvent system acetic acid: formic acid: acetone was chosen for further testing. The second phase of the experiment was aimed at producing of fiber layers with different surface density. The spinning was carried out on a rotating drum, the surface density was controlled by the spinning time. However, an important parameter is the rotation speed of the rotating drum, which affects the stiffness of the resulting layer. Thus, two rotation speeds of the rotating drum were used during the experiment to compare the strengths of the resulting layers. In the last stage of the experiment, for biological testing were spun two fiber layers with selected spinning parameters, where one fiber ","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129042489","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Photocatalytic processes using TiO2 as photocatalyst have been introduced in the seventies. However, despite lots of advantages, TiO2 must be excited in the UV region, which means that it can absorb only 3% of solar energy it receives. The majority of solar energy is concentrated in the visible region. Therefore, a photocatalyst that is active under visible light is of paramount importance as an essential element of solar photoenergy utilization. A variety of approaches has been attempted in search of visible light active materials. Porphyrins and metalloporphyrins have been widely investigated for their photochemical activity for various applications such as environmental photocatalysis, hydrogen production, and solar cell. The electrochemical potentials for the porphyrin ring being the redox center is readily dependent on the kind of central metal ions. Among a series of metalloporphyrins, tin(IV)-porphyrin has a strong oxidative capacity (porphyrin ring reduced easily) owing to the high charge on tin(IV) and the excited tin-porphyrin exhibits a high activity for the photooxidation of organic compounds under visible light [1]. We have interests in the photocatalysts based on tin-porphyrin with strong visible light absorption as an efficient visible light photocatalyst for an environmental remediation [2-4] and H2 production [5,6]. We here present TiO2 hybrid nanomaterials incorporated with tin(IV) porphyrins exhibiting visible light activities: (i) Tin(IV) porphyrins incorporated-TiO2 nanotubes with 152 m/g of surface area and 0.44 cm/g of porosity showing visible-lightactivated photocatalytic production of H2. (ii) A ternary hybrid material of semiconductor/polymer/porphyrin in which the surface of TiO2 particles coated with perfluorosulfonate polymer (Nafion) binds water-soluble cationic tin(IV) porphyrins within the Nafion layer through electrostatic attraction. H2 evolution activity in this ternary hybrid material was estimated to be 1.5 times higher than that in TiO2-porphyrin without Nafion.
{"title":"Fabrication and Visible Light Photocatalytic Activities of TiO2 Nanomaterials Incorporated with Tin(IV) Porphyrins","authors":"Gi-Seon Lee, S. Kim, Canghai Lee, Hee-Joon Kim","doi":"10.11159/ICNFA19.123","DOIUrl":"https://doi.org/10.11159/ICNFA19.123","url":null,"abstract":"Extended Abstract Photocatalytic processes using TiO2 as photocatalyst have been introduced in the seventies. However, despite lots of advantages, TiO2 must be excited in the UV region, which means that it can absorb only 3% of solar energy it receives. The majority of solar energy is concentrated in the visible region. Therefore, a photocatalyst that is active under visible light is of paramount importance as an essential element of solar photoenergy utilization. A variety of approaches has been attempted in search of visible light active materials. Porphyrins and metalloporphyrins have been widely investigated for their photochemical activity for various applications such as environmental photocatalysis, hydrogen production, and solar cell. The electrochemical potentials for the porphyrin ring being the redox center is readily dependent on the kind of central metal ions. Among a series of metalloporphyrins, tin(IV)-porphyrin has a strong oxidative capacity (porphyrin ring reduced easily) owing to the high charge on tin(IV) and the excited tin-porphyrin exhibits a high activity for the photooxidation of organic compounds under visible light [1]. We have interests in the photocatalysts based on tin-porphyrin with strong visible light absorption as an efficient visible light photocatalyst for an environmental remediation [2-4] and H2 production [5,6]. We here present TiO2 hybrid nanomaterials incorporated with tin(IV) porphyrins exhibiting visible light activities: (i) Tin(IV) porphyrins incorporated-TiO2 nanotubes with 152 m/g of surface area and 0.44 cm/g of porosity showing visible-lightactivated photocatalytic production of H2. (ii) A ternary hybrid material of semiconductor/polymer/porphyrin in which the surface of TiO2 particles coated with perfluorosulfonate polymer (Nafion) binds water-soluble cationic tin(IV) porphyrins within the Nafion layer through electrostatic attraction. H2 evolution activity in this ternary hybrid material was estimated to be 1.5 times higher than that in TiO2-porphyrin without Nafion.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132120470","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
This study aims to synthesis and characterize of poly (methyl methacrylate) nanocomposites that based on methyl methacrylate monomer (MMA) and zinc oxide nanoparticles (ZnO-NPs), namely PMMA/ZnO nanocomposite via in-situ emulsion polymerization of MMA monomer using potassium persulphate (PPS) as initiator. ZnO-NPs were firstly prepared through hydrothermal method. The prepared ZnO-NPs were investigated by X-Ray diffraction pattern (XRD), Fourier transform infrared (FT-IR) and transmission electron microscope (TEM). PMMA/ZnO nanocomposites were prepared via emulsion polymerization using different concentrations of ZnO-NPs (2%, 4%, 8% and 12%) based on monomer concentration. Furthermore, PMMA/ZnO nanocomposites were studied using FT-IR, TEM, XRD, UV/Vis spectroscopy and thermal gravimetric analysis (TGA). The fabricated poly (methyl methacrylate) nanocomposites display good morphological, thermal properties and antibacterial activity than pure PMMA. Additionally, the PMMA nanocomposites display respectable antimicrobial activity against gram positive (Staphylococcus aureus) bacteria, gram negative (Pseudomonas aeruginosa) bacteria and yeast (Candida albicans). Additionally, the PMMA nanocomposites can be used as good materials for antibacterial packaging applications.
{"title":"Preparation and Characterization of PMMA Nanocomposites Based On Zno-Nps for Antibacterial Packaging Applications","authors":"A. Youssef, Islam E EL-Nagar","doi":"10.11159/ICNFA19.105","DOIUrl":"https://doi.org/10.11159/ICNFA19.105","url":null,"abstract":"This study aims to synthesis and characterize of poly (methyl methacrylate) nanocomposites that based on methyl methacrylate monomer (MMA) and zinc oxide nanoparticles (ZnO-NPs), namely PMMA/ZnO nanocomposite via in-situ emulsion polymerization of MMA monomer using potassium persulphate (PPS) as initiator. ZnO-NPs were firstly prepared through hydrothermal method. The prepared ZnO-NPs were investigated by X-Ray diffraction pattern (XRD), Fourier transform infrared (FT-IR) and transmission electron microscope (TEM). PMMA/ZnO nanocomposites were prepared via emulsion polymerization using different concentrations of ZnO-NPs (2%, 4%, 8% and 12%) based on monomer concentration. Furthermore, PMMA/ZnO nanocomposites were studied using FT-IR, TEM, XRD, UV/Vis spectroscopy and thermal gravimetric analysis (TGA). The fabricated poly (methyl methacrylate) nanocomposites display good morphological, thermal properties and antibacterial activity than pure PMMA. Additionally, the PMMA nanocomposites display respectable antimicrobial activity against gram positive (Staphylococcus aureus) bacteria, gram negative (Pseudomonas aeruginosa) bacteria and yeast (Candida albicans). Additionally, the PMMA nanocomposites can be used as good materials for antibacterial packaging applications.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"141 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127768984","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract Rice (Oryza sativa) specific color hull phenotype is a classical morphological marker that has long been applied to breeding and genetics study. The discovery and utilization of specific genetic resources provided a new strategy for innovative seed production technology. Recently, several mutants which had been reported showed abnormal hull colors, brown or black , e.g. gh1, gh2, gh3, gh4, gh5, gh6, bh4, bh6, ibf1, cad2 and lsi1[1-6], and the function of these corresponding genes were usually involved in flavonoid biosynthesis. However, less is known about the mechanism of flavonoid biosynthesis and metabolism regulating in rice. In this study, we characterized a natural mutant with red pigmentation in the hull furrows in the background of cultivated rice variety O. sativa indica cv Xianhui207 based on forward genetic method, which was termed as rh4. Compared with other marker traits, the stable red hull phenotype of rh4 mutant is more powerful and intuitive for the rapid selection of hybrid seeds to solve the current critical technical problems in mixed-sowing seed production. RH4 gene was cloned in rice via a map-based cloning approach. RH4 encodes an uncharacterized protein and contains a transmembrane domain, which is similar to a generally expressed protein. RH4 expresses in most tissues of rice and most abundantly in hulls. RH4 was localized not only on the nucleus but also at the plasma membrane, which suggests RH4 may play an important part in activating or suppressing the expression of downstream genes in flavonoid biosynthesis and may be taken as a signal conduction receptor. The mutation of RH4 caused that the relative expression level of some key genes related to the flavonoid biosynthesis including CHS and CHI could be upor downregulated to some different extent in rh4 mutant via real-time PCR, which also verified by the proteomic analysis. The Whole Genome Bisulfite-seq (WGBS) analysis displayed there were several hypo differentially methylated regions (DMRs) genes e.g. F3’H, F3’5’H in CHH in flavonoid biosynthesis pathway. We also detected three remarkable phosphoproteins in flavonoid biosynthesis in rh4 mutant, such as CHS (134T, 1.427), CHI (232S, 179S, 177S, 2.006) and F3'H (178S, 275S, 107S, 1.429). These data implied RH4 may regulate flavonoids biosynthesis from epigenetic modification and post-translational levels. Moreover, profiles of several sorts of flavonoids was changed significantly, e.g. Cyanidin 3-[6-(3-glucosylcaffeyl) glucoside]-5-glucoside. Some anthocyanin content were reduced compared to wild type, e,g. prunin 6''-O-gallate was distinctly decreased fourfold, while the procyanidins were elevated, and catechin 7-O-apiofuranoside which showed red pigmentation was increased twofold. These findings demonstrated RH4 indirectly took part in the flavonoid biosynthesis pathway in rice and made flavonoids flux from procyanidins to anthocyanin. Our results suggest RH4 may inhibit reddish-brown pigmentatio
{"title":"A Novel Gene RH4, Inhibiting Pigment Deposition in Rice Hull Furrows By Participating In Flavonoid Biosynthesis","authors":"Ling Liu, Meijuan Duan","doi":"10.11159/ICBB19.125","DOIUrl":"https://doi.org/10.11159/ICBB19.125","url":null,"abstract":"Extended Abstract Rice (Oryza sativa) specific color hull phenotype is a classical morphological marker that has long been applied to breeding and genetics study. The discovery and utilization of specific genetic resources provided a new strategy for innovative seed production technology. Recently, several mutants which had been reported showed abnormal hull colors, brown or black , e.g. gh1, gh2, gh3, gh4, gh5, gh6, bh4, bh6, ibf1, cad2 and lsi1[1-6], and the function of these corresponding genes were usually involved in flavonoid biosynthesis. However, less is known about the mechanism of flavonoid biosynthesis and metabolism regulating in rice. In this study, we characterized a natural mutant with red pigmentation in the hull furrows in the background of cultivated rice variety O. sativa indica cv Xianhui207 based on forward genetic method, which was termed as rh4. Compared with other marker traits, the stable red hull phenotype of rh4 mutant is more powerful and intuitive for the rapid selection of hybrid seeds to solve the current critical technical problems in mixed-sowing seed production. RH4 gene was cloned in rice via a map-based cloning approach. RH4 encodes an uncharacterized protein and contains a transmembrane domain, which is similar to a generally expressed protein. RH4 expresses in most tissues of rice and most abundantly in hulls. RH4 was localized not only on the nucleus but also at the plasma membrane, which suggests RH4 may play an important part in activating or suppressing the expression of downstream genes in flavonoid biosynthesis and may be taken as a signal conduction receptor. The mutation of RH4 caused that the relative expression level of some key genes related to the flavonoid biosynthesis including CHS and CHI could be upor downregulated to some different extent in rh4 mutant via real-time PCR, which also verified by the proteomic analysis. The Whole Genome Bisulfite-seq (WGBS) analysis displayed there were several hypo differentially methylated regions (DMRs) genes e.g. F3’H, F3’5’H in CHH in flavonoid biosynthesis pathway. We also detected three remarkable phosphoproteins in flavonoid biosynthesis in rh4 mutant, such as CHS (134T, 1.427), CHI (232S, 179S, 177S, 2.006) and F3'H (178S, 275S, 107S, 1.429). These data implied RH4 may regulate flavonoids biosynthesis from epigenetic modification and post-translational levels. Moreover, profiles of several sorts of flavonoids was changed significantly, e.g. Cyanidin 3-[6-(3-glucosylcaffeyl) glucoside]-5-glucoside. Some anthocyanin content were reduced compared to wild type, e,g. prunin 6''-O-gallate was distinctly decreased fourfold, while the procyanidins were elevated, and catechin 7-O-apiofuranoside which showed red pigmentation was increased twofold. These findings demonstrated RH4 indirectly took part in the flavonoid biosynthesis pathway in rice and made flavonoids flux from procyanidins to anthocyanin. Our results suggest RH4 may inhibit reddish-brown pigmentatio","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114395014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Are Tailings Waste?","authors":"M. Fall","doi":"10.11159/ICEPR19.02","DOIUrl":"https://doi.org/10.11159/ICEPR19.02","url":null,"abstract":"","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"52 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127152074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Extended Abstract The harvested electrical energy is used in a variety of electronic equipment such as remote sensors, automobiles, medical or military equipment, etc. As the energy demand increases, the need for an efficient energy harvesting system increases and the relevant researches are actively carried out [1-5]. Cross-flow turbine is a water impulse turbine with relatively low efficiency, but it can be adjusted at various flow rates and is easy to maintain. As the working fluid passes through the impeller of the cross-flow hydraulic turbine and forms a vortex field at downstream, the induced vortex flow can be used for converting the kinetic energy inherent in vibrations to electricity using energy harvesters such as cantilevers, membranes or other structures. In this study, the cantilever beams were located at the downstream of cross-flow hydraulic turbine for microenergy harvesting. Numerical analysis was conducted using the commercial code, ANSYS CFX 18.1 with the k-ω based shear stress transport (SST) turbulence model. The effect of distance between cantilever beams on stress and strain was evaluated using 2-way fluid-structure interaction (FSI) analysis. As a result, the maximum von-Mises stress of the cantilever beam was calculated as 163.5MPa, and the maximum deformation was calculated as 2.29mm. In addition, the results were graphically depicted with various geometrical and flow conditions.
{"title":"Fluid-Structure Interaction Analysis on Cantilever Beams for Micro-Energy Harvesting of Cross-flow Turbine","authors":"Y. Je, Youn-J. Kim","doi":"10.11159/ICEPR19.127","DOIUrl":"https://doi.org/10.11159/ICEPR19.127","url":null,"abstract":"Extended Abstract The harvested electrical energy is used in a variety of electronic equipment such as remote sensors, automobiles, medical or military equipment, etc. As the energy demand increases, the need for an efficient energy harvesting system increases and the relevant researches are actively carried out [1-5]. Cross-flow turbine is a water impulse turbine with relatively low efficiency, but it can be adjusted at various flow rates and is easy to maintain. As the working fluid passes through the impeller of the cross-flow hydraulic turbine and forms a vortex field at downstream, the induced vortex flow can be used for converting the kinetic energy inherent in vibrations to electricity using energy harvesters such as cantilevers, membranes or other structures. In this study, the cantilever beams were located at the downstream of cross-flow hydraulic turbine for microenergy harvesting. Numerical analysis was conducted using the commercial code, ANSYS CFX 18.1 with the k-ω based shear stress transport (SST) turbulence model. The effect of distance between cantilever beams on stress and strain was evaluated using 2-way fluid-structure interaction (FSI) analysis. As a result, the maximum von-Mises stress of the cantilever beam was calculated as 163.5MPa, and the maximum deformation was calculated as 2.29mm. In addition, the results were graphically depicted with various geometrical and flow conditions.","PeriodicalId":265434,"journal":{"name":"Proceedings of the 5th World Congress on New Technologies","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2019-08-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121699716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：