Search results for: solar cells and solar modules
2855 Adapting Tools for Text Monitoring and for Scenario Analysis Related to the Field of Social Disasters
Authors: Svetlana Cojocaru, Mircea Petic, Inga Titchiev
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Humanity faces more and more often with different social disasters, which in turn can generate new accidents and catastrophes. To mitigate their consequences, it is important to obtain early possible signals about the events which are or can occur and to prepare the corresponding scenarios that could be applied. Our research is focused on solving two problems in this domain: identifying signals related that an accident occurred or may occur and mitigation of some consequences of disasters. To solve the first problem, methods of selecting and processing texts from global network Internet are developed. Information in Romanian is of special interest for us. In order to obtain the mentioned tools, we should follow several steps, divided into preparatory stage and processing stage. Throughout the first stage, we manually collected over 724 news articles and classified them into 10 categories of social disasters. It constitutes more than 150 thousand words. Using this information, a controlled vocabulary of more than 300 keywords was elaborated, that will help in the process of classification and identification of the texts related to the field of social disasters. To solve the second problem, the formalism of Petri net has been used. We deal with the problem of inhabitants’ evacuation in useful time. The analysis methods such as reachability or coverability tree and invariants technique to determine dynamic properties of the modeled systems will be used. To perform a case study of properties of extended evacuation system by adding time, the analysis modules of PIPE such as Generalized Stochastic Petri Nets (GSPN) Analysis, Simulation, State Space Analysis, and Invariant Analysis have been used. These modules helped us to obtain the average number of persons situated in the rooms and the other quantitative properties and characteristics related to its dynamics.Keywords: lexicon of disasters, modelling, Petri nets, text annotation, social disasters
Procedia PDF Downloads 1972854 Dynamic Programming Based Algorithm for the Unit Commitment of the Transmission-Constrained Multi-Site Combined Heat and Power System
Authors: A. Rong, P. B. Luh, R. Lahdelma
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High penetration of intermittent renewable energy sources (RES) such as solar power and wind power into the energy system has caused temporal and spatial imbalance between electric power supply and demand for some countries and regions. This brings about the critical need for coordinating power production and power exchange for different regions. As compared with the power-only systems, the combined heat and power (CHP) systems can provide additional flexibility of utilizing RES by exploiting the interdependence of power and heat production in the CHP plant. In the CHP system, power production can be influenced by adjusting heat production level and electric power can be used to satisfy heat demand by electric boiler or heat pump in conjunction with heat storage, which is much cheaper than electric storage. This paper addresses multi-site CHP systems without considering RES, which lay foundation for handling penetration of RES. The problem under study is the unit commitment (UC) of the transmission-constrained multi-site CHP systems. We solve the problem by combining linear relaxation of ON/OFF states and sequential dynamic programming (DP) techniques, where relaxed states are used to reduce the dimension of the UC problem and DP for improving the solution quality. Numerical results for daily scheduling with realistic models and data show that DP-based algorithm is from a few to a few hundred times faster than CPLEX (standard commercial optimization software) with good solution accuracy (less than 1% relative gap from the optimal solution on the average).Keywords: dynamic programming, multi-site combined heat and power system, relaxed states, transmission-constrained generation unit commitment
Procedia PDF Downloads 3652853 USBware: A Trusted and Multidisciplinary Framework for Enhanced Detection of USB-Based Attacks
Authors: Nir Nissim, Ran Yahalom, Tomer Lancewiki, Yuval Elovici, Boaz Lerner
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Background: Attackers increasingly take advantage of innocent users who tend to use USB devices casually, assuming these devices benign when in fact they may carry an embedded malicious behavior or hidden malware. USB devices have many properties and capabilities that have become the subject of malicious operations. Many of the recent attacks targeting individuals, and especially organizations, utilize popular and widely used USB devices, such as mice, keyboards, flash drives, printers, and smartphones. However, current detection tools, techniques, and solutions generally fail to detect both the known and unknown attacks launched via USB devices. Significance: We propose USBWARE, a project that focuses on the vulnerabilities of USB devices and centers on the development of a comprehensive detection framework that relies upon a crucial attack repository. USBWARE will allow researchers and companies to better understand the vulnerabilities and attacks associated with USB devices as well as providing a comprehensive platform for developing detection solutions. Methodology: The framework of USBWARE is aimed at accurate detection of both known and unknown USB-based attacks by a process that efficiently enhances the framework's detection capabilities over time. The framework will integrate two main security approaches in order to enhance the detection of USB-based attacks associated with a variety of USB devices. The first approach is aimed at the detection of known attacks and their variants, whereas the second approach focuses on the detection of unknown attacks. USBWARE will consist of six independent but complimentary detection modules, each detecting attacks based on a different approach or discipline. These modules include novel ideas and algorithms inspired from or already developed within our team's domains of expertise, including cyber security, electrical and signal processing, machine learning, and computational biology. The establishment and maintenance of the USBWARE’s dynamic and up-to-date attack repository will strengthen the capabilities of the USBWARE detection framework. The attack repository’s infrastructure will enable researchers to record, document, create, and simulate existing and new USB-based attacks. This data will be used to maintain the detection framework’s updatability by incorporating knowledge regarding new attacks. Based on our experience in the cyber security domain, we aim to design the USBWARE framework so that it will have several characteristics that are crucial for this type of cyber-security detection solution. Specifically, the USBWARE framework should be: Novel, Multidisciplinary, Trusted, Lightweight, Extendable, Modular and Updatable and Adaptable. Major Findings: Based on our initial survey, we have already found more than 23 types of USB-based attacks, divided into six major categories. Our preliminary evaluation and proof of concepts showed that our detection modules can be used for efficient detection of several basic known USB attacks. Further research, development, and enhancements are required so that USBWARE will be capable to cover all of the major known USB attacks and to detect unknown attacks. Conclusion: USBWARE is a crucial detection framework that must be further enhanced and developed.Keywords: USB, device, cyber security, attack, detection
Procedia PDF Downloads 3972852 Thermal Simulation for Urban Planning in Early Design Phases
Authors: Diego A. Romero Espinosa
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Thermal simulations are used to evaluate comfort and energy consumption of buildings. However, the performance of different urban forms cannot be assessed precisely if an environmental control system and user schedules are considered. The outcome of such analysis would lead to conclusions that combine the building use, operation, services, envelope, orientation and density of the urban fabric. The influence of these factors varies during the life cycle of a building. The orientation, as well as the surroundings, can be considered a constant during the lifetime of a building. The structure impacts the thermal inertia and has the largest lifespan of all the building components. On the other hand, the building envelope is the most frequent renovated component of a building since it has a great impact on energy performance and comfort. Building services have a shorter lifespan and are replaced regularly. With the purpose of addressing the performance, an urban form, a specific orientation, and density, a thermal simulation method were developed. The solar irradiation is taken into consideration depending on the outdoor temperature. Incoming irradiation at low temperatures has a positive impact increasing the indoor temperature. Consequently, overheating would be the combination of high outdoor temperature and high irradiation at the façade. On this basis, the indoor temperature is simulated for a specific orientation of the evaluated urban form. Thermal inertia and building envelope performance are considered additionally as the materiality of the building. The results of different thermal zones are summarized using the 'Degree day method' for cooling and heating. During the early phase of a design process for a project, such as Masterplan, conclusions regarding urban form, density and materiality can be drawn by means of this analysis.Keywords: building envelope, density, masterplanning, urban form
Procedia PDF Downloads 1452851 Pathways and Mechanisms of Lymphocytes Emigration from Newborn Thymus
Authors: Olena Grygorieva
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Nowadays mechanisms of thymocytes emigration from the thymus to the periphery are investigated actively. We have proposed a hypothesis of thymocytes’ migration from the thymus through lymphatic vessels during periodical short-term local edema. By morphological, hystochemical methods we have examined quantity of lymphocytes, epitelioreticulocytes, mast cells, blood and lymphatic vessels in morpho-functional areas of rats’ thymuses during the first week after birth in 4 hours interval. In newborn and beginning from 8 hour after birth every 12 hours specific density of the thymus, absolute quantity of microcirculatory vessels, especially of lymphatic ones, lymphcyte-epithelial index, quantity of mast cells and their degranulative forms increase. Structure of extracellular matrix, intrathymical microenvironment and lymphocytes’ adhesive properties change. Absolute quantity of small lymphocytes in thymic cortex changes wavy. All these changes are straightly expressed from 0 till 2, from 12 till 16, from 108 till 120 hours of postnatal life. During this periods paravasal lymphatic vessels are stuffed with lymphocytes, i.e. discrete migration of lymphocytes from the thymus occurs. After rapid edema reduction, quantity of lymphatic vessels decrease, they become empty. Therefore, in the thymus of newborn periodical short-term local edema is observed, on its top discrete migration of lymphocytes from the thymus occurs.Keywords: lymphocytes, lymphatic vessels, mast cells, thymus
Procedia PDF Downloads 2252850 A Pink-Pigmented Facultative Methylobacterium sp Isolated from Retama monosperma Root Nodules
Authors: N. Selami, M. Kaid Harche
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A pink-pigmented, aerobic, facultatively methylotrophic bacterium, was isolated from Retama monosperma root nodules and identified as a member of the genus Methylobacterium. Inoculation of R. monosperma plants by a pure culture of isolate strain under a hydroponic condition, resulted, 10 dpi, the puffiness at lateral roots. The observation in detail the anatomy and ultra-structure of infection sites by light and electron microscopy show that the bacteria induce stimulation of the division of cortical cells and digestion of epidermis cells then, Methylobacterium was observed in the inter and intracellular spaces of the outer cortex root. These preliminary results allow us to suggest the establishment of an epi-endosymbiotic interaction between Methylobacterium sp and R. monosperma.Keywords: endophytic colonization, Methylobacterium, microscopy, nodule, pink pigmented, Retama monosperma
Procedia PDF Downloads 3642849 Data-Driven Simulations Tools for Der and Battery Rich Power Grids
Authors: Ali Moradiamani, Samaneh Sadat Sajjadi, Mahdi Jalili
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Power system analysis has been a major research topic in the generation and distribution sections, in both industry and academia, for a long time. Several load flow and fault analysis scenarios have been normally performed to study the performance of different parts of the grid in the context of, for example, voltage and frequency control. Software tools, such as PSCAD, PSSE, and PowerFactory DIgSILENT, have been developed to perform these analyses accurately. Distribution grid had been the passive part of the grid and had been known as the grid of consumers. However, a significant paradigm shift has happened with the emergence of Distributed Energy Resources (DERs) in the distribution level. It means that the concept of power system analysis needs to be extended to the distribution grid, especially considering self sufficient technologies such as microgrids. Compared to the generation and transmission levels, the distribution level includes significantly more generation/consumption nodes thanks to PV rooftop solar generation and battery energy storage systems. In addition, different consumption profile is expected from household residents resulting in a diverse set of scenarios. Emergence of electric vehicles will absolutely make the environment more complicated considering their charging (and possibly discharging) requirements. These complexities, as well as the large size of distribution grids, create challenges for the available power system analysis software. In this paper, we study the requirements of simulation tools in the distribution grid and how data-driven algorithms are required to increase the accuracy of the simulation results.Keywords: smart grids, distributed energy resources, electric vehicles, battery storage systsms, simulation tools
Procedia PDF Downloads 1032848 Experimental Monitoring of the Parameters of the Ionosphere in the Local Area Using the Results of Multifrequency GNSS-Measurements
Authors: Andrey Kupriyanov
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In recent years, much attention has been paid to the problems of ionospheric disturbances and their influence on the signals of global navigation satellite systems (GNSS) around the world. This is due to the increase in solar activity, the expansion of the scope of GNSS, the emergence of new satellite systems, the introduction of new frequencies and many others. The influence of the Earth's ionosphere on the propagation of radio signals is an important factor in many applied fields of science and technology. The paper considers the application of the method of transionospheric sounding using measurements from signals from Global Navigation Satellite Systems to determine the TEC distribution and scintillations of the ionospheric layers. To calculate these parameters, the International Reference Ionosphere (IRI) model of the ionosphere, refined in the local area, is used. The organization of operational monitoring of ionospheric parameters is analyzed using several NovAtel GPStation6 base stations. It allows performing primary processing of GNSS measurement data, calculating TEC and fixing scintillation moments, modeling the ionosphere using the obtained data, storing data and performing ionospheric correction in measurements. As a result of the study, it was proved that the use of the transionospheric sounding method for reconstructing the altitude distribution of electron concentration in different altitude range and would provide operational information about the ionosphere, which is necessary for solving a number of practical problems in the field of many applications. Also, the use of multi-frequency multisystem GNSS equipment and special software will allow achieving the specified accuracy and volume of measurements.Keywords: global navigation satellite systems (GNSS), GPstation6, international reference ionosphere (IRI), ionosphere, scintillations, total electron content (TEC)
Procedia PDF Downloads 1812847 Effect of Grayanotoxins on Skeletal Muscle Cell C2C12
Authors: Bayan Almofty, Yuto Yamaki, Tadamasa Terai, Sadahito Uto
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Myopathy (muscles disease) treatment are expected in the field of regenerative medicine and applied research of cultured muscle to bio actuator is performed in Biomedical Engineering as applied research of cultured muscle. This study is about cultured myoblast C2C12 from mouse skeletal muscle and a mechanism of cultured muscle contraction by electric stimulation is investigated. Grayanotoxins (GTXs) belong to neurotoxins known to enhance the permeability of cell membrane for Na ions. Grayanotoxins are extracted from a famous Pieris japonica and Ericaceae as a phytotoxin. We investigated the functional role of GTXs on muscle cells (C2C12) contraction and membrane potential. A change in membrane potential is measured using a micro glass tube electrode contraction of myotubes is induced by applying an external electrical stimulation. The contraction and membrane potential change induced by injection of current using the micro glass electrode are also measured. From the result, contraction and membrane potential of muscle cells was affected by GTXs treatment, suggesting that the diverse chemical structures of GTXs are responsible for contraction and membrane potential of muscle cells.Keywords: skeletal muscle, C2C12, myoblast, myotubes, contraction, Grayanotoxins, membrane potential, neurotoxins, phytotoxin
Procedia PDF Downloads 4682846 Anticancer Study of Copper and Zinc Complexes with Doxorubicin
Authors: Grzegorz Swiderski, Agata Jablonska-Trypuc, Natalia Popow, Renata Swislocka, Wlodzimierz Lewandowski
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Doxorubicin belongs to the group of anthracycline antitumor antibiotics. Because of the wide spectrum of actions, it is one of the most widely used anthracycline antibiotics, including the treatment of breast, ovary, bladder, lung cancers as well as neuroblastoma, lymphoma, leukemia and myeloid leukemia. Antitumor activity of doxorubicin is based on the same mechanisms as for most anthracyclines. Like the metal ions affect the nucleic acids on many biological processes, so the environment of the metal chelates of antibiotics can have a significant effect on the pharmacological properties of drugs. Complexation of anthracyclines with metal ions may contribute to the production of less toxic compounds. In the framework of this study, the composition of complexes obtained in aqueous solutions of doxorubicin with metal ions (Cu2+ and Zn2+). Complexation was analyzed by spectrophotometric titration in aqueous solution at pH 7.0. The pH was adjusted with 0.02M Tris-HCl buffer. The composition of the complexes found was Cu: doxorubicin (1: 2) and a Zn: doxorubicin (1: 1). The effect of Dox, Dox-Cu and Dox-Zn was examined in MCF-7 breast cancer cell line, which were obtained from American Type Culture Collection (ATCC). The compounds were added to the cultured cells for a final concentration in the range of 0,01µM to 0,5µM. The number of MCF-7 cells with division into living and dead, was determined by direct counts of cells with the use of trypan blue dye using LUNA Logos Biosystems cell counter. ApoTox-Glo Triplex Assay (Promega, Madison, Wisconsin, USA) was used according to the manufacturer’s instructions to measure the MCF-7 cells’ viability, cytotoxicity and apoptosis. We observed a decrease in cells proliferation in a dose-dependent manner. An increase in cytotoxicity and decrease in viability in the ApoTox Triplex assay was also showed for all tested compounds. Apoptosis, showed as caspase 3/7 activation, was observed only in Dox treatment. In Dox-Zn and Dox-Cu caspase 3/7 activation was not observed. This work was financially supported by National Science Centre, Poland, under the research project number 2014/13/B/NZ7/02 352.Keywords: anticancer properties, anthracycline antibiotic, doxorubicine, metal complexes
Procedia PDF Downloads 2802845 Biologically Synthesised Silver Nanoparticles Induces Autophagy and JNK Signaling as a Pro-Survival Response by Abrogating Reactive Oxygen Species Accumulation in Cancer Cells
Authors: Sudeshna Mukherjee, Leena Fageria, R. Venkataramana Dilip, Rajdeep Chowdhury, Jitendra Panwar
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Metal nanoparticles in recent years have gained importance in cancer therapy due to their enhanced permeability retention effect. Among various nanomaterials, silver nanoparticles (AgNPs) have received considerable attention due to their unique properties like conductivity, chemical stability, relative lower toxicity and outstanding therapeutic potential, such as anti-inflammatory, antimicrobial and anti-cancerous activities. In this study, we took a greener approach to synthesize silver nanoparticle from fungus and analyze its effects on both epithelial and mesenchymal derived cancer cells. Much research has been done on nanoparticle-induced apoptosis, but little is known about its role in autophagy. In our study, the silver nanoparticles were seen to induce autophagy which was analyzed by studying the expression of several autophagy markers like, LC3B-II and ATG genes. Monodansylcadaverine (MDC) assay also revealed the induction of autophagy upon treatment with AgNPs. Inhibition of autophagy by chloroquine resulted in increased cell death suggesting autophagy as a survival strategy adopted by the cells. In parallel to autophagy induction, silver nanoparticles induced ROS accumulation. Interestingly, autophagy inhibition by chloroquine increased ROS level, resulting in enhanced cell death. We further analyzed MAPK signaling upon AgNP treatment. It was observed that along with autophagy, activation of JNK signaling served as pro-survival while ERK signaling served as a pro-death signal. Our results provide valuable insights into the role of autophagy upon AgNP exposure and provide cues to probabilistic strategies to effectively sensitize cancer cells.Keywords: autophagy, JNK signalling, reactive oxygen species, silver nanoparticles
Procedia PDF Downloads 3642844 Protective Role of Autophagy Challenging the Stresses of Type 2 Diabetes and Dyslipidemia
Authors: Tanima Chatterjee, Maitree Bhattacharyya
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The global challenge of type 2 diabetes mellitus is a major health concern in this millennium, and researchers are continuously exploring new targets to develop a novel therapeutic strategy. Type 2 diabetes mellitus (T2DM) is often coupled with dyslipidemia increasing the risks for cardiovascular (CVD) complications. Enhanced oxidative and nitrosative stresses appear to be the major risk factors underlying insulin resistance, dyslipidemia, β-cell dysfunction, and T2DM pathogenesis. Autophagy emerges to be a promising defense mechanism against stress-mediated cell damage regulating tissue homeostasis, cellular quality control, and energy production, promoting cell survival. In this study, we have attempted to explore the pivotal role of autophagy in T2DM subjects with or without dyslipidemia in peripheral blood mononuclear cells and insulin-resistant HepG2 cells utilizing flow cytometric platform, confocal microscopy, and molecular biology techniques like western blotting, immunofluorescence, and real-time polymerase chain reaction. In the case of T2DM with dyslipidemia higher population of autophagy, positive cells were detected compared to patients with the only T2DM, which might have resulted due to higher stress. Autophagy was observed to be triggered both by oxidative and nitrosative stress revealing a novel finding of our research. LC3 puncta was observed in peripheral blood mononuclear cells and periphery of HepG2 cells in the case of the diabetic and diabetic-dyslipidemic conditions. Increased expression of ATG5, LC3B, and Beclin supports the autophagic pathway in both PBMC and insulin-resistant Hep G2 cells. Upon blocking autophagy by 3-methyl adenine (3MA), the apoptotic cell population increased significantly, as observed by caspase‐3 cleavage and reduced expression of Bcl2. Autophagy has also been evidenced to control oxidative stress-mediated up-regulation of inflammatory markers like IL-6 and TNF-α. To conclude, this study elucidates autophagy to play a protective role in the case of diabetes mellitus with dyslipidemia. In the present scenario, this study demands to have a significant impact on developing a new therapeutic strategy for diabetic dyslipidemic subjects by enhancing autophagic activity.Keywords: autophagy, apoptosis, dyslipidemia, reactive oxygen species, reactive nitrogen species, Type 2 diabetes
Procedia PDF Downloads 1292843 Identification of Promiscuous Epitopes for Cellular Immune Responses in the Major Antigenic Protein Rv3873 Encoded by Region of Difference 1 of Mycobacterium tuberculosis
Authors: Abu Salim Mustafa
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Rv3873 is a relatively large size protein (371 amino acids in length) and its gene is located in the immunodominant genomic region of difference (RD)1 that is present in the genome of Mycobacterium tuberculosis but deleted from the genomes of all the vaccine strains of Bacillus Calmette Guerin (BCG) and most other mycobacteria. However, when tested for cellular immune responses using peripheral blood mononuclear cells from tuberculosis patients and BCG-vaccinated healthy subjects, this protein was found to be a major stimulator of cell mediated immune responses in both groups of subjects. In order to further identify the sequence of immunodominant epitopes and explore their Human Leukocyte Antigen (HLA)-restriction for epitope recognition, 24 peptides (25-mers overlapping with the neighboring peptides by 10 residues) covering the sequence of Rv3873 were synthesized chemically using fluorenylmethyloxycarbonyl chemistry and tested in cell mediated immune responses. The results of these experiments helped in the identification of an immunodominant peptide P9 that was recognized by people expressing varying HLA-DR types. Furthermore, it was also predicted to be a promiscuous binder with multiple epitopes for binding to HLA-DR, HLA-DP and HLA-DQ alleles of HLA-class II molecules that present antigens to T helper cells, and to HLA-class I molecules that present antigens to T cytotoxic cells. In addition, the evaluation of peptide P9 using an immunogenicity predictor server yielded a high score (0.94), which indicated a greater probability of this peptide to elicit a protective cellular immune response. In conclusion, P9, a peptide with multiple epitopes and ability to bind several HLA class I and class II molecules for presentation to cells of the cellular immune response, may be useful as a peptide-based vaccine against tuberculosis.Keywords: mycobacterium tuberculosis, PPE68, peptides, vaccine
Procedia PDF Downloads 1352842 Integrated Modeling of Transformation of Electricity and Transportation Sectors: A Case Study of Australia
Authors: T. Aboumahboub, R. Brecha, H. B. Shrestha, U. F. Hutfilter, A. Geiges, W. Hare, M. Schaeffer, L. Welder, M. Gidden
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The proposed stringent mitigation targets require an immediate start for a drastic transformation of the whole energy system. The current Australian energy system is mainly centralized and fossil fuel-based in most states with coal and gas-fired plants dominating the total produced electricity over the recent past. On the other hand, the country is characterized by a huge, untapped renewable potential, where wind and solar energy could play a key role in the decarbonization of the Australia’s future energy system. However, integrating high shares of such variable renewable energy sources (VRES) challenges the power system considerably due to their temporal fluctuations and geographical dispersion. This raises the concerns about flexibility gap in the system to ensure the security of supply with increasing shares of such intermittent sources. One main flexibility dimension to facilitate system integration of high shares of VRES is to increase the cross-sectoral integration through coupling of electricity to other energy sectors alongside the decarbonization of the power sector and reinforcement of the transmission grid. This paper applies a multi-sectoral energy system optimization model for Australia. We investigate the cost-optimal configuration of a renewable-based Australian energy system and its transformation pathway in line with the ambitious range of proposed climate change mitigation targets. We particularly analyse the implications of linking the electricity and transport sectors in a prospective, highly renewable Australian energy system.Keywords: decarbonization, energy system modelling, renewable energy, sector coupling
Procedia PDF Downloads 1332841 Hydrogel Hybridizing Temperature-Cured Dissolvable Gelatin Microspheres as Non-Anchorage Dependent Cell Carriers for Tissue Engineering Applications
Authors: Dong-An Wang
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All kinds of microspheres have been extensively employed as carriers for drug, gene and therapeutic cell delivery. Most therapeutic cell delivery microspheres rely on a two-step methodology: fabrication of microspheres and subsequent seeding of cells onto them. In this study, we have developed a novel one-step cell encapsulation technique using a convenient and instant water-in-oil single emulsion approach to form cell-encapsulated gelatin microspheres. This technology is adopted for hyaline cartilage tissue engineering, in which autologous chondrocytes are used as therapeutic cells. Cell viability was maintained throughout and after the microsphere formation (75-100 µm diameters) process that avoids involvement of any covalent bonding reactions or exposure to any further chemicals. Further encapsulation of cell-laden microspheres in alginate gels were performed under 4°C via a prompt process. Upon the formation of alginate constructs, they were immediately relocated into CO2 incubator where the temperature was maintained at 37°C; under this temperature, the cell-laden gelatin microspheres dissolved within hours to yield similarly sized cavities and the chondrocytes were therefore suspended within the cavities inside the alginate gel bulk. Hence, the gelatin cell-laden microspheres served two roles: as cell delivery vehicles which can be removable through temperature curing, and as porogens within an alginate hydrogel construct to provide living space for cell growth and tissue development as well as better permeability for mutual diffusions. These cell-laden microspheres, namely “temperature-cured dissolvable gelatin microsphere based cell carriers” (tDGMCs), were further encapsulated in a chondrocyte-laden alginate scaffold system and analyzed by WST-1, gene expression analyses, biochemical assays, histology and immunochemistry stains. The positive results consistently demonstrated the promise of tDGMC technology in delivering these non-anchorage dependent cells (chondrocytes). It can be further conveniently translated into delivery of other non-anchorage dependent cell species, including stem cells, progenitors or iPS cells, for regeneration of tissues in internal organs, such as engineered hepatogenesis or pancreatic regeneration.Keywords: biomaterials, tissue engineering, microsphere, hydrogel, porogen, anchorage dependence
Procedia PDF Downloads 3962840 Follicular Fluid Proteins and Cells Study on Small, Medium, and Large Follicles of Large White Pig
Authors: Mayuva Youngsabanant-Areekijseree, Chanikarn Srinark, S. Sengsai, Mayuree Pumipaiboon
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Our project was aimed at morphology of oocytes, follicle cells and follicular fluid proteins study of Large White pig (at local slaughter house in Nakhon Pathom Province). The porcine oocytes and follicular fluid of healthy small follicles (1-2 mm), medium follicles (3-6 mm in diameters) and large follicles (7-8 mm and 10 mm in diameter) were aspirated and collected from the ovary by sterile technique. Then, the oocytes and the follicle cells were separated from the fluid. The oocytes were round shape and surrounded by zona pellucida with numerous layers of cumulus cells. Based on the number of cumulus cell layers surrounding oocytes, the oocytes were classified into 5 types, which were intact-, multi-, partial-cumulus layer oocyte, completely denuded oocyte and degenerative oocyte. The collected oocytes showed high percentages of intact- and multi- cumulus cell layers in the small follicles (53.48%) medium follicles (56.94%) and large follicles (56.52%) which have high potential to develop into mature oocytes in vitro. Proteins from follicular fluid of 3 size follicles were separated by SDS-PAGE and LC/MS/MS. The molecular weight of follicular fluid proteins from the small follicles were 24, 60-65, 79, 110, 140, 160, and > 220 kDa. Meanwhile, the follicular fluid protein from medium and large follicle contained 52, 65, 79, 90, 110, 120, 160, 190 and > 220 kDa. Almost all proteins played important roles in promoting and regulating growth and development of oocytes and ovulation. This finding was an initial tool for in vitro testing and applied biotechnology research. Acknowledgements: The project was funded by a grant from Silpakorn University Research & Development Institute (SURDI) and Faculty of Science, Silpakorn University, Thailand.Keywords: follicular fluid protein, LC/MS/MS, porcine oocyte, SDS-PAGE, reproductive biology
Procedia PDF Downloads 2352839 Hydrothermal Synthesis of V₂O₅-Carbon Nanotube Composite for Supercapacitor Application
Authors: Mamta Bulla, Vinay Kumar
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The transition to renewable energy sources is essential due to the finite limitations of conventional fossil fuels, which contribute significantly to environmental pollution and greenhouse gas emissions. Traditional energy storage solutions, such as batteries and capacitors, are also hindered by limitations, particularly in capacity, cycle life, and energy density. Conventional supercapacitors, while able to deliver high power, often suffer from low energy density, limiting their efficiency in storing and providing renewable energy consistently. Renewable energy sources, such as solar and wind, produce power intermittently, so efficient energy storage solutions are required to manage this variability. Advanced materials, particularly those with high capacity and long cycle life, are critical to developing supercapacitors capable of effectively storing renewable energy. Among various electrode materials, vanadium pentoxide (V₂O₅) offers high theoretical capacitance, but its poor conductivity and cycling stability limit practical applications. This study explores the hydrothermal synthesis of a V₂O₅-carbon nanotube (CNT) composite to overcome these drawbacks, combining the high capacitance of V₂O₅ with the exceptional conductivity and mechanical stability of CNTs. The resulting V₂O₅-CNT composite demonstrates enhanced electrochemical performance, showing high specific capacitance of 890 F g⁻¹ at 0.1 A g⁻¹ current density, excellent rate capability, and improved cycling stability, making it a promising candidate for next-generation supercapacitors, with significant improvements in energy storage efficiency and durability.Keywords: cyclability, energy density, nanocomposite, renewable energy, supercapacitor
Procedia PDF Downloads 112838 The Antidiabetic Properties of Indonesian Swietenia mahagoni in Alloxan-Induced Diabetic Rats
Authors: T. Wresdiyati, S. Sa’diah, A. Winarto
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Diabetes mellitus (DM) is a metabolic disease that can be indicated by the high level of blood glucose. The objective of this study was to observe the antidiabetic properties of ethanolic extract of Indonesian Swietenia mahagoni Jacq. seed on the profile of pancreatic superoxide dismutase and β-cells in the alloxan- experimental diabetic rats. The Swietenia mahagoni seed was obtained from Leuwiliang-Bogor, Indonesia. Extraction of Swietenia mahagoni was done by using ethanol with maceration methods. A total of 25 male Sprague dawley rats were divided into five groups; (a) negative control group, (b) positive control group (DM), (c) DM group that was treated with Swietenia mahagoni seed extract, (d) DM group that was treated with acarbose, and (e) non-DM group that was treated with Swietenia mahagoni seed extract. The DM groups were induced by alloxan (110 mg/kgBW). The extract was orally administrated to diabetic rats 500 mg/kg/BW/day for 28 days. The extract showed hypoglycemic effect, increased body weight, increased the content of superoxide dismutase in the pancreatic tissue, and delayed the rate of β-cells damage of experimental diabetic rats. These results suggested that the ethanolic extract of Indonesian Swietenia mahagoni Jacq. seed could be proposed as a potential anti-diabetic agent.Keywords: beta cells, diabetes, hypoglycemic, rat, Swietenia mahagoni
Procedia PDF Downloads 2942837 Zeolite Supported Iron-Sensitized TIO₂ for Tetracycline Photocatalytic Degradation under Visible Light: A Comparison between Doping and Ion Exchange
Authors: Ghadeer Jalloul, Nour Hijazi, Cassia Boyadjian, Hussein Awala, Mohammad N. Ahmad, Ahmad Albadarin
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In this study, we applied Fe-sensitized TiO₂ supported over embryonic Beta zeolite (BEA) zeolite for the photocatalytic degradation of Tetracycline (TC) antibiotic under visible light. Four different samples having 20, 40, 60, and 100% w/w as a ratio of TiO₂/BEA were prepared. The immobilization of solgel TiO₂ (33 m²/g) over BEA (390 m²/g) increased its surface area to (227 m²/g) and enhanced its adsorption capacity from 8% to 19%. To expand the activity of TiO₂ photocatalyst towards the visible light region (λ>380 nm), we explored two different metal sensitization techniques with Iron ions (Fe³⁺). In the ion-exchange method, the substitutional cations in the zeolite in TiO₂/BEA were exchanged with (Fe³⁺) in an aqueous solution of FeCl₃. In the doping technique, solgel TiO₂ was doped with (Fe³⁺) from FeCl₃ precursor during its synthesis and before its immobilization over BEA. (Fe-TiO₂/BEA) catalysts were characterized using SEM, XRD, BET, UV-VIS DRS, and FTIR. After testing the performance of the various ion-exchanged catalysts under blue and white lights, only (Fe-TiO₂/BEA 60%) showed better activity as compared to pure TiO₂ under white light with 100 ppm initial catalyst concentration and 20 ppm TC concentration. As compared to ion-exchanged (Fe-TiO₂/BEA), doped (Fe-TiO₂/BEA) resulted in higher photocatalytic efficiencies under blue and white lights. The 3%-Fe-doped TiO₂/BEA removed 92% of TC compared to 54% by TiO₂ under white light. The catalysts were also tested under real solar irradiations. This improvement in the photocatalytic performance of TiO₂ was due to its higher adsorption capacity due to BEA support combined with the presence of Iron ions that enhance the visible light absorption and minimize the recombination effect by the charge carriers. Keywords: Tetracycline, photocatalytic degradation, immobilized TiO₂, zeolite, iron-doped TiO₂, ion-exchange
Procedia PDF Downloads 1062836 Growth of Metal Oxide (Tio2/Ag) Thin Films Sputtered by Hipims Effective in Bacterial Inactivation: Plasma Chemistry and Energetic
Authors: O. Baghriche, A. Zertal, C. Pulgarin, J. Kiwi, R. Sanjines
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High-Power Impulse Magnetron Sputtering (HIPIMS) is a technology that belongs to the field of Ionized PVD of thin films. This study shows the first complete report on ultrathin TiO2/Ag nano-particulate films sputtered by highly ionized pulsed plasma magnetron sputtering (HIPIMS) leading to fast bacterial loss of viability. The Ag and the TiO2/Ag sputtered films induced complete Escherichia coli inactivation in the dark, which was not observed in the case of TiO2. When Ag was present, the bacterial inactivation was accelerated under low intensity solar simulated light and this has implications for a potential for a practical technology. The design, preparation, testing and surface characterization of these innovative films are described in this study. The HIPIMS sputtered composite films present an appreciable savings in metals compared to films obtained by conventional sputtering methods. HIPIMS sputtering induces a strong interaction with the rugous polyester 3-D structure due to the higher fraction of the Ag-ions (M+) attained in the magnetron chamber. The immiscibility of Ag and TiO2 in the TiO2/Ag films is shown by High Angular Dark Field (HAADF) microscopy. The ionization degree of the film forming species is significantly increased and film growth is assisted by an intense ion flux. Reports have revealed the significant enhancement of the film properties as the HIPIMS technology is used. However, a decrease of the deposition rate, as compared to the conventional DC magnetron sputtering Pulsed (DCMSP) process is commonly observed during HIPIMS.Keywords: E. coli, HIPIMS, inactivation bacterial, sputtering
Procedia PDF Downloads 3002835 Findings on Modelling Carbon Dioxide Concentration Scenarios in the Nairobi Metropolitan Region before and during COVID-19
Authors: John Okanda Okwaro
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Carbon (IV) oxide (CO₂) is emitted majorly from fossil fuel combustion and industrial production. The sources of interest of carbon (IV) oxide in the study area are mining activities, transport systems, and industrial processes. This study is aimed at building models that will help in monitoring the emissions within the study area. Three scenarios were discussed, namely: pessimistic scenario, business-as-usual scenario, and optimistic scenario. The result showed that there was a reduction in carbon dioxide concentration by approximately 50.5 ppm between March 2020 and January 2021 inclusive. This is majorly due to reduced human activities that led to decreased consumption of energy. Also, the CO₂ concentration trend follows the business-as-usual scenario (BAU) path. From the models, the pessimistic, business-as-usual, and optimistic scenarios give CO₂ concentration of about 545.9 ppm, 408.1 ppm, and 360.1 ppm, respectively, on December 31st, 2021. This research helps paint the picture to the policymakers of the relationship between energy sources and CO₂ emissions. Since the reduction in CO₂ emission was due to decreased use of fossil fuel as there was a decrease in economic activities, then if Kenya relies more on green energy than fossil fuel in the post-COVID-19 period, there will be more CO₂ emission reduction. That is, the CO₂ concentration trend is likely to follow the optimistic scenario path, hence a reduction in CO₂ concentration of about 48 ppm by the end of the year 2021. This research recommends investment in solar energy by energy-intensive companies, mine machinery and equipment maintenance, investment in electric vehicles, and doubling tree planting efforts to achieve the 10% cover.Keywords: forecasting, greenhouse gas, green energy, hierarchical data format
Procedia PDF Downloads 1672834 Causes for the Precession of the Perihelion in the Planetary Orbits
Authors: Kwan U. Kim, Jin Sim, Ryong Jin Jang, Sung Duk Kim
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It is Leverrier that discovered the precession of the perihelion in the planetary orbits for the first time in the world, while it is Einstein that explained the astronomical phenomenom for the first time in the world. The amount of the precession of the perihelion for Einstein’s theory of gravitation has been explained by means of the inverse fourth power force(inverse third power potential) introduced totheory of gravitation through Schwarzschild metric However, the methodology has a serious shortcoming that it is impossible to explain the cause for the precession of the perihelion in the planetary orbits. According to our study, without taking the cause for the precession of the perihelion, 6 methods can explain the amount of the precession of the perihelion discovered by Leverrier. Therefore, the problem of what caused the perihelion to precess in the planetary orbits must be solved for physics because it is a profound scientific and technological problem for a basic experiment in construction of relativistic theory of gravitation. The scientific solution to the problem proved that Einstein’s explanation for the planetary orbits is a magic made by the numerical expressions obtained from fictitious gravitation introduced to theory of gravitation and wrong definition of proper time The problem of the precession of the perihelion seems solved already by means of general theory of relativity, but, in essence, the cause for the astronomical phenomenon has not been successfully explained for astronomy yet. The right solution to the problem comes from generalized theory of gravitation. Therefore, in this paper, it has been shown that by means of Schwarzschild field and the physical quantities of relativistic Lagrangian redflected in it, fictitious gravitation is not the main factor which can cause the perihelion to precess in the planetary orbits. In addition to it, it has been shown that the main factor which can cause the perihelion to precess in the planetary orbits is the inverse third power force existing really in the relativistic region in the Solar system.Keywords: inverse third power force, precession of the perihelion, fictitious gravitation, planetary orbits
Procedia PDF Downloads 102833 Angiomotin Regulates Integrin Beta 1-Mediated Endothelial Cell Migration and Angiogenesis
Authors: Yuanyuan Zhang, Yujuan Zheng, Giuseppina Barutello, Sumako Kameishi, Kungchun Chiu, Katharina Hennig, Martial Balland, Federica Cavallo, Lars Holmgren
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Angiogenesis describes that new blood vessels migrate from pre-existing ones to form 3D lumenized structure and remodeling. During directional migration toward the gradient of pro-angiogenic factors, the endothelial cells, especially the tip cells need filopodia to sense the environment and exert the pulling force. Of particular interest are the integrin proteins, which play an essential role in focal adhesion in the connection between migrating cells and extracellular matrix (ECM). Understanding how these biomechanical complexes orchestrate intrinsic and extrinsic forces is important for our understanding of the underlying mechanisms driving angiogenesis. We have previously identified Angiomotin (Amot), a member of Amot scaffold protein family, as a promoter for endothelial cell migration in vitro and zebrafish models. Hence, we established inducible endothelial-specific Amot knock-out mice to study normal retinal angiogenesis as well as tumor angiogenesis. We found that the migration ratio of the blood vessel network to the edge was significantly decreased in Amotec- retinas at postnatal day 6 (P6). While almost all the Amot defect tip cells lost migration advantages at P7. In consistence with the dramatic morphology defect of tip cells, there was a non-autonomous defect in astrocytes, as well as the disorganized fibronectin expression pattern correspondingly in migration front. Furthermore, the growth of transplanted LLC tumor was inhibited in Amot knockout mice due to fewer vasculature involved. By using MMTV-PyMT transgenic mouse model, there was a significantly longer period before tumors arised when Amot was specifically knocked out in blood vessels. In vitro evidence showed that Amot binded to beta-actin, Integrin beta 1 (ITGB1), Fibronectin, FAK, Vinculin, major focal adhesion molecules, and ITGB1 and stress fibers were distinctly induced by Amot transfection. Via traction force microscopy, the total energy (force indicater) was found significantly decreased in Amot knockdown cells. Taken together, we propose that Amot is a novel partner of the ITGB1/Fibronectin protein complex at focal adhesion and required for exerting force transition between endothelial cell and extracellular matrix.Keywords: angiogenesis, angiomotin, endothelial cell migration, focal adhesion, integrin beta 1
Procedia PDF Downloads 2372832 Apoptosis Inducing Potential of Onosma Bracteata Wall. in Mg-63 Human Osteosarcoma Cells via cdk2/Cyclin E Pathway
Authors: Ajay Kumar, Satwinderjeet Kaur
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Onosma bracteata Wall. (Boraginaceae), is known to be a medicinal plant, useful in the treatment of body swellings, abdominal pain and urinary calculi, etc. The present study focused on the radical scavenging and cancer growth inhibitory properties of isolates from O. bracteata. Obea fraction demonstrated noticeable free radical scavenging ability along with antiproliferative activity in human osteosarcoma MG-63, human neuroblastoma IMR-32, and human lung cancer A549 cell lines using MTT assay with GI50 values of 88.56, 101.61 and 112.7 μg/ml, respectively. The scanning electron and confocal microscopy studies showed morphological alterations including nuclear condensation and formation of apoptotic bodies in osteosarcoma MG-63 cells. Obea fraction in osteosarcoma MG-63 cells augmented the reactive oxygen species (ROS) level and decreased the mitochondrial membrane potential. Flow cytometry analysis revealed the Obea treated cells to be arrested in the G0/G1 phase in a dose dependent manner supported by the observed increase in the early apoptotic cell population. Western blotting analysis showed that the expression of p-NF-kB, COX-2, p-Akt, and Bcl-xL decreased whereas, the expression of GSK-3β, p53, caspase-3 and caspase-9 proteins increased. The downregulation of Bcl-2, Cyclin E, CDK2 and mortalin gene expression and upregulation of p53 genes was unfolded in RT-qPCR studies. The presence of catechin, kaempferol, Onosmin A and epicatechin, as revealed in high-performance liquid chromatography (HPLC) studies, contributes towards the chemopreventive potential of O. bracteata which can be tapped for chemotherapeutic use.Keywords: apoptosis, confocal microscopy, HPLC, mitochondria membrane potential, reactive oxygen species
Procedia PDF Downloads 1362831 The Effect of the Combination of Methotrexate Nanoparticles and TiO2 on Breast Cancer
Authors: Nusaiba Al-Nemrawi, Belal Al-Husein
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Methotrexate (MTX) is a stoichiometric inhibitor of dihydrofolate reductase, which is essential for DNA synthesis. MTX is a chemotherapeutic agent used for treating many types of cancer cells. However, cells’ resistant to MTX is very common and its pharmacokinetic behavior is highly problematic. of MTX within tumor cells, we propose encapsulation of antitumor drugs in nanoparticulated systems. Chitosan (CS) is a naturally occurring polymer that is biocompatibe, biodegradable, non-toxic, cationic and bioadhesive. CS nanoparticles (CS-NPs) have been used as drug carrier for targeted delivery. Titanium dioxide (TiO2), a natural mineral oxide, which is used in biomaterials due to its high stability and antimicrobial and anticorrosive properties. TiO2 showed a potential as a tumor suppressor. In this study a new formulation of MTX loaded in CS NPs (CS-MTX NPs) and coated with Titanium oxide (TiO2) was prepared. The mean particle size, zeta potential, polydispersity index were measured. The interaction between CS NPs and TiO2 NPs was confirmed using FTIR and XRD. CS-MTX NPs was studied in vitro using the tumor cell line MCF-7 (human breast cancer). The results showed that CS-MTX has a size around 169 nm and as they were coated with TiO2, the size ranged between and depending on the ratio of CS-MTX to TiO2 ratio used in the preparation. All NPs (uncoated and coated carried positive charges and were monodispersed. The entrapment efficacy was around 65%. Both FTIR and XRD proved that TiO2 interacted with CS-MTX NPs. The drug invitro release was controlled and sustained over days. Finally, the studied in vitro using the tumor cell line MCF-7 suggested that combining nanomaterials with anticancer drugs CS-MTX NPs may be more effective than free MTX for cancer treatment. In conclusion, the combination of CS-MTX NPs and TiO2 NPs showed excellent time-dependent in vitro antitumor behavior, therefore, can be employed as a promising anticancer agent to attain efficient results towards MCF-7 cells.Keywords: Methotrexate, Titanium dioxide, Chitosan nanoparticles, cancer
Procedia PDF Downloads 952830 Comparative Study between Mesenchymal Stem Cells and Regulatory T-Cells in Macrophage Polarization for Organ Transplant Tolerance: In Vitro Study
Authors: Vijaya Madhuri Devraj, Swarnalatha Guditi, Kiran Kumar Bokara, Gangadhar Taduri
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Cell-based strategies may open therapeutic approaches that promote tolerance through manipulation of macrophages to increase long-term transplant survival rates and minimize side effects of the current immune suppressive regimens. The aim of the present study was, therefore, to test and compare the therapeutic potential of MSC and Tregs on macrophage polarization to develop an alternate cell-based treatment option in kidney transplantation. In the current protocol, macrophages from kidney transplant recipients with graft dysfunction were co-cultured with MSCs and Treg cells with and without cell-cell contact on transwell plates, further to quantitatively assess macrophage polarization in response to MSC and Treg treatment over time, M1 and M2 cell surface markers were used. Additionally, multiple soluble analytes were analyzed in cell supernatant by using bead-based immunoassays. Furthermore, to confirm our findings, gene expression analysis was done. MSCs induced the formation of M2 macrophages more than Tregs when macrophages M0 were cultured in transwell without cell contact. From this, we deduced the mechanism that soluble factors present in the MSCs condition media are involved in skewing of macrophages towards type 2 macrophages; similarly, in co-culture with cell-cell contact, MSCs resulted in more M2 type macrophages than Tregs. And an important finding of this study is the combination of both MSC-Treg showed significantly effective and consistent results in both with and without cell contact setups. Hence, it is suggestive to prefer MSCs over Tregs for secretome-based therapy and a combination of both for either therapy for effective transplantation outcomes. Our findings underline a key role of Tregs and MSCs in promoting macrophage polarization towards anti-inflammatory type. The study has great importance in prolongation of allograft and patient survival without any rejection by cell-based therapy, which induce self-tolerance and controlling infection.Keywords: graft rejection, graft tolerance, macrophage polarization, mesenchymal stem cells, regulatory T cells, transplant immunology
Procedia PDF Downloads 1172829 In vitro Effects of Porcine Follicular Fluid Proteins on Cell Culture Growth in Luteal Phase Porcine Oviductal Epithelial Cells
Authors: Mayuva Youngsabanant, Chanikarn Srinark, Supanyika Sengsai, Soratorn Kerdkriangkrai, Nongnuch Gumlungpat, Mayuree Pumipaiboon
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The follicular fluid proteins of healthy medium size follicles (4-6 mm in diameters) and large size follicles (7-8 mm in diameter) of large white pig ovaries were collected by using sterile technique. They were used for testing the effect on primary in vitro cell culture growth of porcine oviductal epithelial cells (pOEC). Porcine oviductal epithelial cells of luteal phase was culture in M199 and added with 10% fetal calf serum 2.2 mg/mL, NaHCO₃, 0.25 mM pyruvate, 15 µg/mL and 50 µg/mL, gentamycin sulfate at high humidified atmosphere with 5% CO₂ in 95% air atmosphere at 37°C for 96 h before testing. The optimized concentration of pFF of two follicle sizes (at concentration of 2, 4, 20, 40, 200, 400, 500, and 600 µg proteins) in culture medium was observed for 24 h using MTT assay. Results were analyzed with a one-way ANOVA in SPSS statistic. Moreover, pOEC was also studied in morphological characteristic on long-term culture. The results of long-term study revealed that pOEC showed 70-80 percentage of healthy morphology on epithelial-like character and contained 30 percentage of an elongated shape (fibroblast-like morphology) at 4 weeks of culture time. MTT assay reviewed an increase in the percentage of viability of pOEC in 2 treated of follicular fluid groups. Two treatment concentration groups were higher than control group (p < 0.05) but not in positive control group. Interestingly, at 200 µg protein of 2 treated follicular fluid groups were reached the highest cell viability which is higher than a positive control and it is significantly different form control group (P < 0.05). These cells are developed and had fibroblast elongate shape which is longer than the cells in control group and positive control group. This report implies that pFF of medium follicle size at 200 µg proteins and large follicle size at 200 and 500 µg proteins could be optimized concentration for using as a supplement in culture medium to promote cell growth and development instead of growth hormone from fetal calf serum. It could be applied in cell biotechnology researches. Acknowledgements: The project was funded by a grant from Silpakorn University Research and Development Institute (SURDI) and Faculty of Science, Silpakorn University, Thailand.Keywords: in vitro, porcine follicular fluid protein (pFF), porcine oviductal epithelial cells (pOEC), MTT
Procedia PDF Downloads 1452828 The Effect of Transparent Oil Wood Stain on the Colour Stability of Spruce Wood during Weathering
Authors: Eliska Oberhofnerova, Milos Panek, Stepan Hysek, Martin Lexa
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Nowadays the use of wood, both indoors and outdoors, is constantly increasing. However wood is a natural organic material and in the exterior is subjected to a degradation process caused by abiotic factors (solar radiation, rain, moisture, wind, dust etc.). This process affects only surface layers of wood but neglecting some of the basic rules of wood protection leads to increased possibility of biological agents attack and thereby influences a function of the wood element. The process of wood degradation can be decreased by proper surface treatment, especially in the case of less naturally durable wood species, as spruce. Modern coating systems are subjected to many requirements such as colour stability, hydrophobicity, low volatile organic compound (VOC) content, long service life or easy maintenance. The aim of this study is to evaluate the colour stability of spruce wood (Picea abies), as the basic parameter indicating the coating durability, treated with two layers of transparent natural oil wood stain and exposed to outdoor conditions. The test specimens were exposed for 2 years to natural weathering and 2000 hours to artificial weathering in UV-chamber. The colour parameters were measured before and during exposure to weathering by the spectrophotometer according to CIELab colour space. The comparison between untreated and treated wood and both testing procedures was carried out. The results showed a significant effect of coating on the colour stability of wood, as expected. Nevertheless, increasing colour changes of wood observed during the exposure to weathering differed according to applied testing procedure - natural and artificial.Keywords: colour stability, natural and artificial weathering, spruce wood, transparent coating
Procedia PDF Downloads 2202827 Incorporation of Growth Factors onto Hydrogels via Peptide Mediated Binding for Development of Vascular Networks
Authors: Katie Kilgour, Brendan Turner, Carly Catella, Michael Daniele, Stefano Menegatti
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In vivo, the extracellular matrix (ECM) provides biochemical and mechanical properties that are instructional to resident cells to form complex tissues with characteristics to develop and support vascular networks. In vitro, the development of vascular networks can be guided by biochemical patterning of substrates via spatial distribution and display of peptides and growth factors to prompt cell adhesion, differentiation, and proliferation. We have developed a technique utilizing peptide ligands that specifically bind vascular endothelial growth factor (VEGF), erythropoietin (EPO), or angiopoietin-1 (ANG1) to spatiotemporally distribute growth factors to cells. This allows for the controlled release of each growth factor, ultimately enhancing the formation of a vascular network. Our engineered tissue constructs (ETCs) are fabricated out of gelatin methacryloyl (GelMA), which is an ideal substrate for tailored stiffness and bio-functionality, and covalently patterned with growth factor specific peptides. These peptides mimic growth factor receptors, facilitating the non-covalent binding of the growth factors to the ETC, allowing for facile uptake by the cells. We have demonstrated in the absence of cells the binding affinity of VEGF, EPO, and ANG1 to their respective peptides and the ability for each to be patterned onto a GelMA substrate. The ability to organize growth factors on an ETC provides different functionality to develop organized vascular networks. Our results demonstrated a method to incorporate biochemical cues into ETCs that enable spatial and temporal control of growth factors. Future efforts will investigate the cellular response by evaluating gene expression, quantifying angiogenic activity, and measuring the speed of growth factor consumption.Keywords: growth factor, hydrogel, peptide, angiogenesis, vascular, patterning
Procedia PDF Downloads 1632826 Biological Activities of Flaxseed Peptides (Linusorbs)
Authors: Youn Young Shim, Ji Hye Kim, Jae Youl Cho, Martin J. T. Reaney
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Flaxseed (Linum usitatissimum L.) is gaining popularity in the food industry as a superfood due to its health-promoting properties. The flax plant synthesizes an array of biologically active cyclic peptides or linusorbs (LOs, a.k.a. cyclolinopeptides) from three or more ribosome-derived precursors. [1–9-NαC]-linusorb B3 and [1–9-NαC]-linusorb B2, suppress immunity, induce apoptosis in human epithelial cancer cell line (Calu-3) cells, and inhibit T-cell proliferation, but the mechanism of LOs action is unknown. Using gene expression analysis in nematode cultures and human cancer cell lines, we have observed that LOs exert their activity, in part, through induction of apoptosis. Specific LOs’ properties include: 1) distribution throughout the body after flaxseed consumption; 2) induce heat shock protein (HSP) 70A production as an indicator of stress and address the issue in Caenorhabditis elegans (exposure of nematode cultures to [1–9-NαC]-linusorb B3 induced a 30% increase in production of the HSP 70A protein); 3) induce apoptosis in Calu-3 cells; and 4) modulate regulatory genes in microarray analysis. These diverse activities indicate that LOs might induce apoptosis in cancer cells or act as versatile platforms to deliver a variety of biologically active molecules for cancer therapy.Keywords: flaxseed, linusorb, cyclic peptide, orbitides, heat shock protein, apoptosis, anti-cancer
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