Search results for: Chan Hee Park
329 Sensing Mechanism of Nano-Toxic Ions Using Quartz Crystal Microbalance
Authors: Chanho Park, Juneseok You, Kuewhan Jang, Sungsoo Na
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Detection technique of nanotoxic materials is strongly imperative, because nano-toxic materials can harmfully influence human health and environment as their engineering applications are growing rapidly in recent years. In present work, we report the DNA immobilized quartz crystal microbalance (QCM) based sensor for detection of nano-toxic materials such as silver ions, Hg2+ etc. by using functionalization of quartz crystal with a target-specific DNA. Since the mass of a target material is comparable to that of an atom, the mass change caused by target binding to DNA on the quartz crystal is so small that it is practically difficult to detect the ions at low concentrations. In our study, we have demonstrated fast and in situ detection of nanotoxic materials using quartz crystal microbalance. We report the label-free and highly sensitive detection of silver ion for present case, which is a typical nano-toxic material by using QCM and silver-specific DNA. The detection is based on the measurement of frequency shift of Quartz crystal from constitution of the cytosine-Ag+-cytosine binding. It is shown that the silver-specific DNA measured frequency shift by QCM enables the capturing of silver ions below 100pM. The results suggest that DNA-based detection opens a new avenue for the development of a practical water-testing sensor.Keywords: nano-toxic ions, quartz crystal microbalance, frequency shift, target-specific DNA
Procedia PDF Downloads 322328 Application of Machine Learning on Google Earth Engine for Forest Fire Severity, Burned Area Mapping and Land Surface Temperature Analysis: Rajasthan, India
Authors: Alisha Sinha, Laxmi Kant Sharma
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Forest fires are a recurring issue in many parts of the world, including India. These fires can have various causes, including human activities (such as agricultural burning, campfires, or discarded cigarettes) and natural factors (such as lightning). This study presents a comprehensive and advanced methodology for assessing wildfire susceptibility by integrating diverse environmental variables and leveraging cutting-edge machine learning techniques across Rajasthan, India. The primary goal of the study is to utilize Google Earth Engine to compare locations in Sariska National Park, Rajasthan (India), before and after forest fires. High-resolution satellite data were used to assess the amount and types of changes caused by forest fires. The present study meticulously analyzes various environmental variables, i.e., slope orientation, elevation, normalized difference vegetation index (NDVI), drainage density, precipitation, and temperature, to understand landscape characteristics and assess wildfire susceptibility. In addition, a sophisticated random forest regression model is used to predict land surface temperature based on a set of environmental parameters.Keywords: wildfire susceptibility mapping, LST, random forest, GEE, MODIS, climatic parameters
Procedia PDF Downloads 22327 Discovering New Organic Materials through Computational Methods
Authors: Lucas Viani, Benedetta Mennucci, Soo Young Park, Johannes Gierschner
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Organic semiconductors have attracted the attention of the scientific community in the past decades due to their unique physicochemical properties, allowing new designs and alternative device fabrication methods. Until today, organic electronic devices are largely based on conjugated polymers mainly due to their easy processability. In the recent years, due to moderate ET and CT efficiencies and the ill-defined nature of polymeric systems the focus has been shifting to small conjugated molecules with well-defined chemical structure, easier control of intermolecular packing, and enhanced CT and ET properties. It has led to the synthesis of new small molecules, followed by the growth of their crystalline structure and ultimately by the device preparation. This workflow is commonly followed without a clear knowledge of the ET and CT properties related mainly to the macroscopic systems, which may lead to financial and time losses, since not all materials will deliver the properties and efficiencies demanded by the current standards. In this work, we present a theoretical workflow designed to predict the key properties of ET of these new materials prior synthesis, thus speeding up the discovery of new promising materials. It is based on quantum mechanical, hybrid, and classical methodologies, starting from a single molecule structure, finishing with the prediction of its packing structure, and prediction of properties of interest such as static and averaged excitonic couplings, and exciton diffusion length.Keywords: organic semiconductor, organic crystals, energy transport, excitonic couplings
Procedia PDF Downloads 253326 Efficacy and Safety of Updated Target Therapies for Treatment of Platinum-Resistant Recurrent Ovarian Cancer
Authors: John Hang Leung, Shyh-Yau Wang, Hei-Tung Yip, Fion, Ho Tsung-chin, Agnes LF Chan
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Objectives: Platinum-resistant ovarian cancer has a short overall survival of 9–12 months and limited treatment options. The combination of immunotherapy and targeted therapy appears to be a promising treatment option for patients with ovarian cancer, particularly to patients with platinum-resistant recurrent ovarian cancer (PRrOC). However, there are no direct head-to-head clinical trials comparing their efficacy and toxicity. We, therefore, used a network to directly and indirectly compare seven newer immunotherapies or targeted therapies combined with chemotherapy in platinum-resistant relapsed ovarian cancer, including antibody-drug conjugates, PD-1 (Programmed death-1) and PD-L1 (Programmed death-ligand 1), PARP (Poly ADP-ribose polymerase) inhibitors, TKIs (Tyrosine kinase inhibitors), and antiangiogenic agents. Methods: We searched PubMed (Public/Publisher MEDLINE), EMBASE (Excerpta Medica Database), and the Cochrane Library electronic databases for phase II and III trials involving PRrOC patients treated with immunotherapy or targeted therapy plus chemotherapy. The quality of included trials was assessed using the GRADE method. The primary outcomes compared were progression-free survival, the secondary outcomes were overall survival and safety. Results: Seven randomized controlled trials involving a total of 2058 PRrOC patients were included in this analysis. Bevacizumab plus chemotherapy showed statistically significant differences in PFS (Progression-free survival) but not OS (Overall survival) for all interested targets and immunotherapy regimens; however, according to the heatmap analysis, bevacizumab plus chemotherapy had a statistically significant risk of ≥grade 3 SAEs (Severe adverse effects), particularly hematological severe adverse events (neutropenia, anemia, leukopenia, and thrombocytopenia). Conclusions: Bevacizumab plus chemotherapy resulted in better PFS as compared with all interested regimens for the treatment of PRrOC. However, statistical differences in SAEs as bevacizumab plus chemotherapy is associated with a greater risk for hematological SAE.Keywords: platinum-resistant recurrent ovarian cancer, network meta-analysis, immune checkpoint inhibitors, target therapy, antiangiogenic agents
Procedia PDF Downloads 81325 Fiber Release from Fabrics with Various Weave Parameters and Finishing Treatments during Washing and Their Marine Biodegradation
Authors: Seoyoun Kim, Chunghee Park
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Microplastics have recently become an issue due to their potentially harmful effects on the marine environment and the human body. The purpose of this study is to investigate the correlation of fiber emissions during the home laundering with the fabric parameters such as yarn density, warp/weft density, and weave structure. Also, the effect of finishing treatments such as reactive dyeing, water-repellent finish, peach skin finish on fiber emissions was evaluated. Furthermore, we studied the biodegradability of fibers in the marine environment compared to those in soil burial and the impact of finishing treatment on the biodegradability. Biodegradability was evaluated by measuring BOD values and tensile strength reduction. The results showed that more fibers were released in the thicker yarn, lower weave density. Also, a weave structure which has less compactness, released more fibers. Peach skin finish with microfibers exposed on the surface caused more fiber release, whereas water-repellent finish reduced the fiber emission. In addition, the biodegradability of the fabrics submerged in the marine environment were lower compared with those buried in the soil. Also, the water-repellent fabric was less biodegradable than the untreated one. Further research is suggested considering the fabrics with various chemical components or geometry and their fouling behavior in the marine environment.Keywords: biodegradation, fibers, microplastic, pollution
Procedia PDF Downloads 137324 Stenotrophomonas maltophilia: The Major Carbapenem Resistance Bacteria from Waste Water Treatment Plant of Pig Farm
Authors: Young-Ji Kim, Jin-Hyeong Park, Hong-Seok Kim, Jung-Whan Chon, Kwang-Yeop Kim, Dong-Hyeon Kim, Il-Byeong Kang, Da-Na Jeong, Jin-Hyeok Yim, Ho-Seok Jang, Kwang-Young Song, Kun-Ho Seo
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Stenotrophomonas maltophilia is one of the emerging opportunistic pathogens, and also known to have extensive drug resistance intrinsically including carbepenems which is last resort for most serious infections. One possible way for S. maltophilia to infect human is via wastewater treatment plant (WWTP). In the period between October 2016 and February 2017, effluent samples of WWTP from 3 different pig farms were collected once a month and screened for isolation of S. maltophilia. Total 16 strains of S. maltophilia were isolated and, the antibiotic susceptibility phenotypes were determined by Vitek 2 system for 16 antibiotics, ampicillin (AMP), amoxicillin/clavulanic acid (AMC), piperacillin/tazobactam (TZP), cefazolin (CZ), cefoxitin (FOX), cefotaxime (CTX), ceftazidime (CAZ), cefepime (FEP), aztreonam (AZT), ertapenem (ETP), imipenem (IMP), amikacin (AK), gentamicin (GN), ciprofloxacin (CIP), tigecycline (TGC) and trimethoprim/sulfamethoxazole (SXT). All isolates showed high resistance to AMP (100%), CZ (100%), FOX (100%), CTX (100%), CAZ (100%), FEP (94%), AZT (100%), ETP (100%), IMP (100%), AK (100%), GN (100%) whereas were susceptible to CIP (0%), TGC (0%), SXT (6%). All strains harbored at least one of the antibiotic resistance determinant such as spgM, rmlA, and rpfF. Some isolates had similar MLST (multilocus sequence typing) types with clinical isolates, suggesting WWTP could have potential role in the transmission of S. maltophilia to aquatic environment and, possibly, to humans.Keywords: Stenotrophomonas maltophilia, Carbapenem resistance, waste water treatment plant, pig farm
Procedia PDF Downloads 463323 A Fundamental Study on the Anchor Performance of Non-Surface Treated Multi CFRP Tendons
Authors: Woo-tai Jung, Jong-sup Park, Jae-yoon Kang, Moon-seoung Keum
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CFRP (Carbon Fiber Reinforced Polymer) is mainly used as reinforcing material for degraded structures owing to its advantages including its non-corrodibility, high strength, and lightweight properties. Recently, dedicated studies focused not only on its simple bonding but also on its tensioning. The tension necessary for prestressing requires the anchoring of multi-CFRP tendons with high capacity and the surface treatment of the CFRP tendons may also constitute an important issue according to the type of anchor. The wedge type, swage type or bonded type anchor can be used to anchor the CFRP tendon. The bonded type anchor presents the disadvantage to lengthen the length of the anchor due to the low bond strength of the CFRP tendon without surface treatment. This study intends to overcome this drawback through the application of a method enlarging the bond area at the end of the CFRP tendon. This method enlarges the bond area by splitting the end of the CFRP tendon along its length and can be applied when CFRP is produced by pultrusion. The application of this method shows that the mono-CFRP tendon and 3-multi CFRP tendon secured the anchor performance corresponding to the tensile performance of the CFRP tendon and that the 7-multi tendon secured anchor performance corresponding to 90% of the tensile strength due to the occurrence of buckling in the steel tube anchorage.Keywords: carbon fiber reinforced polymer (CFRP), tendon, anchor, tensile property, bond strength
Procedia PDF Downloads 247322 The Effectiveness of a Self-Efficacy Psychoeducational Programme to Enhance Outcomes of Patients with End-Stage Renal Disease
Authors: H. C. Chen, S. W. C. Chan, K. Cheng, A. Vathsala, H. K. Sran, H. He
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Background: End-stage renal disease (ESRD) is the last stage of chronic kidney disease. The numbers of patients with ESRD have increased worldwide due to the growing number of aging, diabetes and hypertension populations. Patients with ESRD suffer from physical illness and psychological distress due to complex treatment regimens, which often affect the patients’ social and psychological functioning. As a result, the patients may fail to perform daily self-care and self-management, and consequently experience worsening conditions. Aims: The study aims to examine the effectiveness of a self-efficacy psychoeducational programme on primary outcome (self-efficacy) and secondary outcomes (psychological wellbeing, treatment adherence, and quality of life) in patients with ESRD and haemodialysis in Singapore. Methodology: A randomised controlled, two-group pretest and repeated posttests design will be carried out. A total of 154 participants (n=154) will be recruited. The participants in the control group will receive a routine treatment. The participants in the intervention group will receive a self-efficacy psychoeducational programme in addition to the routine treatment. The programme is a two-session of educational intervention in a week. A booklet, two consecutive sessions of face-to-face individual education, and an abdominal breathing exercise are adopted in the programme. Outcome measurements include Dialysis Specific Self-efficacy Scale, Kidney Disease Quality of Life- 36 Hospital Anxiety and Depression Scale, Renal Adherence Attitudes Questionnaire and Renal Adherence Behaviour Questionnaire. The questionnaires will be used to measure at baseline, 1- and 3- and 6-month follow-up periods. Process evaluation will be conducted with a semi-structured face to face interview. Quantitative data will be analysed using SPSS21.0 software. Qualitative data will be analysed by content analysis. Significance of the study: This study will identify a clinically useful and potentially effective approach to help patients with end-stage renal disease and haemodialysis by enhancing their self-efficacy in self-care behaviour, and therefore improving their psychological well-being, treatment adherence and quality of life. This study will provide information to develop clinical guidelines to improve patients’ disease self-management and to enhance health-related outcomes and it will help reducing disease burden.Keywords: end-stage renal disease (ESRD), haemodialysis, psychoeducation, self-efficacy
Procedia PDF Downloads 322321 The Influence of Structural Disorder and Phonon on Metal-To-Insulator Transition of VO₂
Authors: Sang-Wook Han, In-Hui Hwang, Zhenlan Jin, Chang-In Park
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We used temperature-dependent X-Ray absorption fine structure (XAFS) measurements to examine the local structural properties around vanadium atoms at the V K edge from VO₂ films. A direct comparison of simultaneously-measured resistance and XAFS from the VO₂ films showed that the thermally-driven structural phase transition (SPT) occurred prior to the metal-insulator transition (MIT) during heating, whereas these changed simultaneously during cooling. XAFS revealed a significant increase in the Debye-Waller factors of the V-O and V-V pairs in the {111} direction of the R-phase VO₂ due to the phonons of the V-V arrays along the direction in a metallic phase. A substantial amount of structural disorder existing on the V-V pairs along the c-axis in both M₁ and R phases indicates the structural instability of V-V arrays in the axis. The anomalous structural disorder observed on all atomic sites at the SPT prevents the migration of the V 3d¹ electrons, resulting in a Mott insulator in the M₂-phase VO₂. The anomalous structural disorder, particularly, at vanadium sites, effectively affects the migration of metallic electrons, resulting in the Mott insulating properties in M₂ phase and a non-congruence of the SPT, MIT, and local density of state. The thermally-induced phonons in the {111} direction assist the delocalization of the V 3d¹ electrons in the R phase VO₂ and the electrons likely migrate via the V-V array in the {111} direction as well as the V-V dimerization along the c-axis. This study clarifies that the tetragonal symmetry is essentially important for the metallic phase in VO₂.Keywords: metal-insulator transition, XAFS, VO₂, structural-phase transition
Procedia PDF Downloads 272320 Comparative Gross Anatomical Studies of the Long Bones of the Adult Chinkara and in the Adult Beetal Goat
Authors: Salahud Din, Saima Masood, Hafsa Zaneb, Habib –ur- Rehman, Imad Khan, Muqader Shah
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The objective of this study was to examine the osteomorphological differences between the long bones of adult Chinkara and an adult Beetal goat, using visual observation, which has still not studied. The osseous remains of these small-sized ungulates often encountered, but cannot distinguish, because of the lack of literature. Specimens of the adult Chinkara of known age and sex for osteomorphological studies are collected from the Manglot Wildlife Park and Ungulate Breeding Centre, Nizampur, Pakistan, while the bones of adult Beetal goats are obtained after slaughtering in a slaughterhouse. The research is carried out at the University of Veterinary and Animal Sciences, Lahore, Pakistan. In this research, the main morphological features recorded in the long bones of thoracic limb and pelvic limb of the adult Chinkara, by comparing them to those of the Beetal goat. The most important differences between the two species are noted in the scapula, the humerus, the radius and ulna, the metacarpal, femur, tibia metatarsal and phalanges. In conclusion, the present study suggests that the morphology of the long bones of adult Chinkara has different from the Beetal goat in various points of view. Based on these recorded points, long bones of these two species can easily be differentiated. The study is helpful in zooarcheological, comparative osteometric studies, for forensic specialists and veterinary anatomists.Keywords: Beetal goat, Chinkara, comparative morphological features, long bones, osteology
Procedia PDF Downloads 133319 Development of a Combustible Gas Detector with Two Sensor Modules to Enable Measuring Range of Low Concentration
Authors: Young Gyu Kim, Sangguk Ahn, Gyoutae Park, Hiesik Kim
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In the gas industrial fields, there are many problems to detect extremely small amounts of combustible gas (CH₄) if a conventional semiconductor is used. Those reasons are that measuring is difficult at the low concentration level, the stabilization time is long, and an initial response time is slow. In this study, we propose a method to solve these issues using two specific sensors to overcome the circumstances of temperature and humidity. This idea is to combine a catalytic and a semiconductor type sensor and to utilize every advantage from every sensor’s characteristic. In order to achieve the goal, we reduced fluctuations of a gas sensor for temperature and humidity by applying designed circuits for sensing temperature and humidity. And we induced the best calibration line of gas sensors through adjusting a weight value corresponding to changeable patterns of temperature and humidity after their data are previously acquired and stored. We proposed and developed the gas leak detector using two sensor modules, which is first operated by a semiconductor sensor for measuring small gas quantities and second a catalytic type sensor is detected if measuring range of the first sensor is beyond. We conclusively verified characteristics of sharp sensitivity and fast response time against even at lower gas concentration level through experiments other than a conventional gas sensor. We think that our proposed idea is very useful if another gas leak is developed to enable measuring extremely small quantities of toxic and flammable gases.Keywords: gas sensor, leak detector, lower concentration, and calibration
Procedia PDF Downloads 240318 Improving Topic Quality of Scripts by Using Scene Similarity Based Word Co-Occurrence
Authors: Yunseok Noh, Chang-Uk Kwak, Sun-Joong Kim, Seong-Bae Park
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Scripts are one of the basic text resources to understand broadcasting contents. Since broadcast media wields lots of influence over the public, tools for understanding broadcasting contents are more required. Topic modeling is the method to get the summary of the broadcasting contents from its scripts. Generally, scripts represent contents descriptively with directions and speeches. Scripts also provide scene segments that can be seen as semantic units. Therefore, a script can be topic modeled by treating a scene segment as a document. Because scripts consist of speeches mainly, however, relatively small co-occurrences among words in the scene segments are observed. This causes inevitably the bad quality of topics based on statistical learning method. To tackle this problem, we propose a method of learning with additional word co-occurrence information obtained using scene similarities. The main idea of improving topic quality is that the information that two or more texts are topically related can be useful to learn high quality of topics. In addition, by using high quality of topics, we can get information more accurate whether two texts are related or not. In this paper, we regard two scene segments are related if their topical similarity is high enough. We also consider that words are co-occurred if they are in topically related scene segments together. In the experiments, we showed the proposed method generates a higher quality of topics from Korean drama scripts than the baselines.Keywords: broadcasting contents, scripts, text similarity, topic model
Procedia PDF Downloads 319317 A Comprehensive CFD Model for Sugar-Cane Bagasse Heterogeneous Combustion in a Grate Boiler System
Authors: Daniel José de Oliveira Ferreira, Juan Harold Sosa-Arnao, Bruno Cássio Moreira, Leonardo Paes Rangel, Song Won Park
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The comprehensive CFD models have been used to represent and study the heterogeneous combustion of biomass. In the present work, the operation of a global flue gas circuit in the sugar-cane bagasse combustion, from wind boxes below primary air grate supply, passing by bagasse insertion in swirl burners and boiler furnace, to boiler bank outlet is simulated. It uses five different meshes representing each part of this system located in sequence: wind boxes and grate, boiler furnace, swirl burners, super heaters and boiler bank. The model considers turbulence using standard k-ε, combustion using EDM, radiation heat transfer using DTM with 16 ray directions and bagasse particle tracking represented by Schiller-Naumann model. The results showed good agreement with expected behavior found in literature and equipment design. The more detailed results view in separated parts of flue gas system allows to observe some flow behaviors that cannot be represented by usual simplifications like bagasse supply under homogeneous axial and rotational vectors and others that can be represented using new considerations like the representation of 26 thousand grate orifices by 144 rectangular inlets.Keywords: comprehensive CFD model, sugar-cane bagasse combustion, sugar-cane bagasse grate boiler, axial
Procedia PDF Downloads 474316 Signal Amplification Using Graphene Oxide in Label Free Biosensor for Pathogen Detection
Authors: Agampodi Promoda Perera, Yong Shin, Mi Kyoung Park
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The successful detection of pathogenic bacteria in blood provides important information for early detection, diagnosis and the prevention and treatment of infectious diseases. Silicon microring resonators are refractive-index-based optical biosensors that provide highly sensitive, label-free, real-time multiplexed detection of biomolecules. We demonstrate the technique of using GO (graphene oxide) to enhance the signal output of the silicon microring optical sensor. The activated carboxylic groups in GO molecules bind directly to single stranded DNA with an amino modified 5’ end. This conjugation amplifies the shift in resonant wavelength in a real-time manner. We designed a capture probe for strain Staphylococcus aureus of 21 bp and a longer complementary target sequence of 70 bp. The mismatched target sequence we used was of Streptococcus agalactiae of 70 bp. GO is added after the complementary binding of the probe and target. GO conjugates to the unbound single stranded segment of the target and increase the wavelength shift on the silicon microring resonator. Furthermore, our results show that GO could successfully differentiate between the mismatched DNA sequences from the complementary DNA sequence. Therefore, the proposed concept could effectively enhance sensitivity of pathogen detection sensors.Keywords: label free biosensor, pathogenic bacteria, graphene oxide, diagnosis
Procedia PDF Downloads 469315 A Study on the Improvement of Mobile Device Call Buzz Noise Caused by Audio Frequency Ground Bounce
Authors: Jangje Park, So Young Kim
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The market demand for audio quality in mobile devices continues to increase, and audible buzz noise generated in time division communication is a chronic problem that goes against the market demand. In the case of time division type communication, the RF Power Amplifier (RF PA) is driven at the audio frequency cycle, and it makes various influences on the audio signal. In this paper, we measured the ground bounce noise generated by the peak current flowing through the ground network in the RF PA with the audio frequency; it was confirmed that the noise is the cause of the audible buzz noise during a call. In addition, a grounding method of the microphone device that can improve the buzzing noise was proposed. Considering that the level of the audio signal generated by the microphone device is -38dBV based on 94dB Sound Pressure Level (SPL), even ground bounce noise of several hundred uV will fall within the range of audible noise if it is induced by the audio amplifier. Through the grounding method of the microphone device proposed in this paper, it was confirmed that the audible buzz noise power density at the RF PA driving frequency was improved by more than 5dB under the conditions of the Printed Circuit Board (PCB) used in the experiment. A fundamental improvement method was presented regarding the buzzing noise during a mobile phone call.Keywords: audio frequency, buzz noise, ground bounce, microphone grounding
Procedia PDF Downloads 136314 Perfluoroheptanoic Acid Affects Xenopus Embryo Embryogenesis by Inducing the Phosphorylation of ERK and JNK
Authors: Chowon Kim, Yoo-Kyung Kim, Kyeong Yeon Park, Hyun-Shik Lee
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Perfluoroalkyl compounds (PFCs) are globally distributed synthetic compounds that are known to adversely affect human health. Developmental toxicity assessment of PFCs is important to facilitate the evaluation of their environmental impact. In the present study, we assessed the developmental toxicity and teratogenicity of PFCs with different numbers of carbon atoms on Xenopus embryogenesis. An initial frog embryo teratogenicity assay-Xenopus (FETAX) assay was performed that identified perfluorohexanoic (PFHxA) and perfluoroheptanoic (PFHpA) acids as potential teratogens and developmental toxicants. The mechanism underlying this teratogenicity was also investigated by measuring the expression of tissue-specific biomarkers such as phosphotyrosine‑binding protein, xPTB (liver); NKX2.5 (heart); and Cyl18 (intestine). Whole‑mount in situ hybridization, reverse transcriptase‑polymerase chain reaction (RT-PCR), and histologic analyses detected severe defects in the liver and heart following exposure to PFHxA or PFHpA. In addition, immunoblotting revealed that PFHpA significantly increased the phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK), while PFHxA slightly increased these, as compared with the control. These results suggest that PFHxA and PFHpA are developmental toxicants and teratogens, with PFHpA producing more severe effects on liver and heart development through the induction of ERK and JNK phosphorylation.Keywords: PFCs, ERK, JNK, xenopus
Procedia PDF Downloads 296313 Study of the Combinatorial Impact of Substrate Properties on Mesenchymal Stem Cell Migration Using Microfluidics
Authors: Nishanth Venugopal Menon, Chuah Yon Jin, Samantha Phey, Wu Yingnan, Zhang Ying, Vincent Chan, Kang Yuejun
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Cell Migration is a vital phenomenon that the cells undergo in various physiological processes like wound healing, disease progression, embryogenesis, etc. Cell migration depends primarily on the chemical and physical cues available in the cellular environment. The chemical cue involves the chemokines secreted and gradients generated in the environment while physical cues indicate the impact of matrix properties like nanotopography and stiffness on the cells. Mesenchymal Stem Cells (MSCs) have been shown to have a role wound healing in vivo and its migration to the site of the wound has been shown to have a therapeutic effect. In the field of stem cell based tissue regeneration of bones and cartilage, one approach has been to introduce scaffold laden with MSCs into the site of injury to enable tissue regeneration. In this work, we have studied the combinatorial impact of the substrate physical properties on MSC migration. A microfluidic in vitro model was created to perform the migration studies. The microfluidic model used is a three compartment device consisting of two cell seeding compartments and one migration compartment. Four different PDMS substrates with varying substrate roughness, stiffness and hydrophobicity were created. Its surface roughness and stiffness was measured using Atomic Force Microscopy (AFM) while its hydrphobicity was measured from the water contact angle using an optical tensiometer. These PDMS substrates are sealed to the microfluidic chip following which the MSCs are seeded and the cell migration is studied over the period of a week. Cell migration was quantified using fluorescence imaging of the cytoskeleton (F-actin) to find out the area covered by the cells inside the migration compartment. The impact of adhesion proteins on cell migration was also quantified using a real-time polymerase chain reaction (qRT PCR). These results suggested that the optimal substrate for cell migration would be one with an intermediate level of roughness, stiffness and hydrophobicity. A higher or lower value of these properties affected cell migration negatively. These observations have helped us in understanding that different substrate properties need to be considered in tandem, especially while designing scaffolds for tissue regeneration as cell migration is normally impacted by the combinatorial impact of the matrix. These observations may lead us to scaffold optimization in future tissue regeneration applications.Keywords: cell migration, microfluidics, in vitro model, stem cell migration, scaffold, substrate properties
Procedia PDF Downloads 557312 Applying Critical Realism to Qualitative Social Work Research: A Critical Realist Approach for Social Work Thematic Analysis Method
Authors: Lynne Soon-Chean Park
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Critical Realism (CR) has emerged as an alternative to both the positivist and constructivist perspectives that have long dominated social work research. By unpacking the epistemic weakness of two dogmatic perspectives, CR provides a useful philosophical approach that incorporates the ontological objectivist and subjectivist stance. The CR perspective suggests an alternative approach for social work researchers who have long been looking to engage in the complex interplay between perceived reality at the empirical level and the objective reality that lies behind the empirical event as a causal mechanism. However, despite the usefulness of CR in informing social work research, little practical guidance is available about how CR can inform methodological considerations in social work research studies. This presentation aims to provide a detailed description of CR-informed thematic analysis by drawing examples from a social work doctoral research of Korean migrants’ experiences and understanding of trust associated with their settlement experience in New Zealand. Because of its theoretical flexibility and accessibility as a qualitative analysis method, thematic analysis can be applied as a method that works both to search for the demi-regularities of the collected data and to identify the causal mechanisms that lay behind the empirical data. In so doing, this presentation seeks to provide a concrete and detailed exemplar for social work researchers wishing to employ CR in their qualitative thematic analysis process.Keywords: critical Realism, data analysis, epistemology, research methodology, social work research, thematic analysis
Procedia PDF Downloads 212311 Sustainability Innovation Capacity Building Framework for UN Sustainable Development Goals
Authors: C. Park, H. Lee, Y-J. Lee
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Aim: This study aims to present the Sustainability Innovation Capacity Building Framework (SICBF) to enable the wider public to achieve UN Sustainable Development Goals (UN SDGs) for a sustainable future. The intrinsically interwoven nature of sustainability requires systematic approaches to attain. However, there is a lack of an effective framework for capacity building that enables a systematic implementation approach for UN SDGs. The SICBF illustrates the six core components and their dynamics: 1. Momentum creation; 2. Exposure to diverse worldviews; 3. Serendipity/Eureka moment; 4. Creative problem solving; 5. Individual empowerment; 6. Systems thinking. Method: First, a structured literature review was used to synthesise existing sustainability competencies studies and generic innovation competencies. Secondly, the conceptual framework based on literature findings was tested with the participants' survey and interview data collected from four sets of MAKEathon events. The interview analysis and event observation data were used to further refine and validate the conceptual framework. Contributions: The scientific contribution of this study is to pave the way for SDGs specific capacity building framework that caters to the need for systematic approaches to allow the wider public aspiring to tackle the seemingly intractable sustainable development goals. The framework will aid sustainable development academics, educators, and practitioners in understanding the dynamics of how capacity building can be facilitated.Keywords: capacity building, sustainability innovation, sustainable development, systems thinking, UN SDGs
Procedia PDF Downloads 83310 The Estimation Method of Inter-Story Drift for Buildings Based on Evolutionary Learning
Authors: Kyu Jin Kim, Byung Kwan Oh, Hyo Seon Park
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The seismic responses-based structural health monitoring system has been performed to reduce seismic damage. The inter-story drift ratio which is the major index of the seismic capacity assessment is employed for estimating the seismic damage of buildings. Meanwhile, seismic response analysis to estimate the structural responses of building demands significantly high computational cost due to increasing number of high-rise and large buildings. To estimate the inter-story drift ratio of buildings from the earthquake efficiently, this paper suggests the estimation method of inter-story drift for buildings using an artificial neural network (ANN). In the method, the radial basis function neural network (RBFNN) is integrated with optimization algorithm to optimize the variable through evolutionary learning that refers to evolutionary radial basis function neural network (ERBFNN). The estimation method estimates the inter-story drift without seismic response analysis when the new earthquakes are subjected to buildings. The effectiveness of the estimation method is verified through a simulation using multi-degree of freedom system.Keywords: structural health monitoring, inter-story drift ratio, artificial neural network, radial basis function neural network, genetic algorithm
Procedia PDF Downloads 327309 Uncertainty in Near-Term Global Surface Warming Linked to Pacific Trade Wind Variability
Authors: M. Hadi Bordbar, Matthew England, Alex Sen Gupta, Agus Santoso, Andrea Taschetto, Thomas Martin, Wonsun Park, Mojib Latif
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Climate models generally simulate long-term reductions in the Pacific Walker Circulation with increasing atmospheric greenhouse gases. However, over two recent decades (1992-2011) there was a strong intensification of the Pacific Trade Winds that is linked with a slowdown in global surface warming. Using large ensembles of multiple climate models forced by increasing atmospheric greenhouse gas concentrations and starting from different ocean and/or atmospheric initial conditions, we reveal very diverse 20-year trends in the tropical Pacific climate associated with a considerable uncertainty in the globally averaged surface air temperature (SAT) in each model ensemble. This result suggests low confidence in our ability to accurately predict SAT trends over 20-year timescale only from external forcing. We show, however, that the uncertainty can be reduced when the initial oceanic state is adequately known and well represented in the model. Our analyses suggest that internal variability in the Pacific trade winds can mask the anthropogenic signal over a 20-year time frame, and drive transitions between periods of accelerated global warming and temporary slowdown periods.Keywords: trade winds, walker circulation, hiatus in the global surface warming, internal climate variability
Procedia PDF Downloads 268308 Carbon Emission Reduction by Compact City Construction in Toyama, Japan
Authors: Benyan Jiang, Dawei Xia, Yong Li
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Compact city construction is considered as an effective measure to reduce carbon emission in city lives. Toyama City started its compact city strategy in 2000 and was selected as a Japanese Environmental Model City in 2008 for its achievement. This paper takes Toyama as a study case, aiming to find how city polices affected people’s life styles and reduced carbon emission. The main materials used in this study are first-hand documents, like urban planning materials, government annual report and statistic data from transportation association. It is found that the main measures taken by Toyama City include the construction of light rail transit, increasing the frequency of buses, building park and ride parking lots. In addition to hardware facilities, it also offers flexible policies like passengers' coupons for the senior citizens and free use of parking lots by buying shopping vouchers. Besides, Toyama City encourages citizens to live within 500 meters of public transportation. People who buy an apartment near public transportation will receive 500,000 Japanese Yen. These measures have proven to their effects. Compared with 2005, in 2014, the transportation sector reduced emissions of 2.35 million tons of CO₂, 13.6%. This aspect is related to the increase in the number of cars in public transport and also related to fuel improvement.Keywords: Toyama, compact city, public transportation, CO₂ reduction
Procedia PDF Downloads 144307 Mixed Matrix Membranes Based on [M₂(DOBDC)] (M = Mg, Co, Ni) and Polydimethylsiloxane for CO₂/N₂ Separation
Authors: Hyunuk Kim, Yang No Yun, Muhammad Sohail, Jong-Ho Moon, Young Cheol Park
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Metal-organic frameworks (MOFs), which are emerging absorbents assembled from metal ions and organic ligands, have attracted attention for their permanent porosity and design of tunable pore size. These microporous materials showed interesting properties for CO₂ storage and separation. In particular, MOFs with high surface area and open metal sites showed the remarkable adsorption capacity and selectivity for CO₂. [Mg₂ (DOBDC)] (DOBDC = 2,5-dioxidobenzene-1,4-dicarboxylate) (MOF-74 or CPO-27) is a well-known absorbent showing an exceptionally high CO₂ sorption capacity at low partial pressure and room temperature. In this work, we synthesized [M₂(DOBDC)(DMF)₂] (M = Mg, Co, Ni) and determined their single-crystal structures by X-ray crystallography. The removal of coordinated guest molecules generates Lewis acidic sites and showed high CO₂ adsorption affinity. Both CO₂ adsorption capacity and surface area are much higher than reported values in literature. To fabricate MMMs, microcrystalline [M₂ (DOBDC)(DMF)₂] was synthesized by microwave reaction and dispersed in PDMS solution. The MMMs with a various amount of [M₂ (DOBDC)(DMF) ₂] in PDMS were fabricated by a solution casting method. [M₂ (DOBDC)(DMF)₂]@PDMS membrane showed higher CO2 permeability and CO₂/N₂ selectivity than those of PDMS. Therefore, we believe that MMMs combining polymer and MOFs provide new materials for CO₂ separation technology.Keywords: metal-organic frameworks, mixed matrix membrane, CO2/N2 separation, polydimethylsiloxane (PDMS)
Procedia PDF Downloads 206306 Suggestion of Two-Step Traction Therapy for Safer and More Effective Conservative Treatment for Low Back Pain
Authors: Won Man Park, Dae Kyung Choi, Kyungsoo Kim, Yoon Hyuk Kim
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Traction therapy has been used in the treatment of spinal pain for decades. However, a case study reported the occurrence of large disc protrusion during motorized traction therapy. In this study, we hypothesized that additional local decompression with a global axial traction could be helpful for risk reduction of intervertebral disc damage. A validated three dimensional finite element model of the lumbar spine was used. Two-step traction therapy using the axial global traction (the first step) with 1/3 body weight and the additional local decompression (the second step) with 7 mm translation of L4 spinal bone was determined for the traction therapy. During two-step traction therapy, the sacrum was constrained in all translational directions. Reduced lordosis angle by the global axial traction recovered with the additional local decompression. Stress on fibers of the annulus fibrosus by the axial global traction decreased with the local decompression by 17%~96% in the posterior region of intervertebral disc. Stresses on ligaments except anterior longitudinal ligaments in all motion segments decreased till 4.9 mm~5.6 mm translation of L4 spinal bone. The results of this study showed that the additional local decompression is very useful for reducing risk of damage in the intervertebral disc and ligaments caused by the global axial traction force. Moreover, the local decompression could be used to enhance reduction of intradiscal pressure.Keywords: lumbar spine, traction-therapy, biomechanics, finite element analysis
Procedia PDF Downloads 486305 Production of Recombinant VP2 Protein of Canine Parvovirus Type 2c Using Baculovirus Expression System
Authors: Jae Young Song, In-Ohk Ouh, Seyeon Park, Byeong Sul Kang, Soo Dong Cho, In-Soo Cho
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Canine parvovirus (CPV) is a major pathogen of diarrhea disease in dogs. CPV type 2 has three of antigenic variants such as 2a, 2b, and 2c. CPV constructs a small non-enveloped, icosahedral capsid that contains single-stranded DNA. It has capsids that two largely overlapping virion proteins (VP), VP1 (82 kDa), and VP2 (65 kDa). Baculoviruses are insect pathogens that regulate insect populations in nature and are being successfully used to control insect pests. The proteins produced in the baculovirus-expression system are used for instance for functional studies, vaccine preparations, or diagnostics. The vaccines produced by baculovirus-expression system showed elicitation of antibodies. The recombinant baculovirus infected SF9 cells showed broken shape. The recombinant VP2 proteins from cell pellet or supernatant were confirmed by western blotting. The result showed that the recombinant VP2 protein bands were appeared at 65 kDa molecular weight in both cell pellet and supernatant of infected SF9 cell. These results indicated that the recombinant baculovirus infected SF9 cell express the recombinant VP2 protein successfully. In addition, the expressed recombinant VP2 protein is secreted from cell to supernatant. The baculovirus expression system can be used to produce the VP2 protein of CPV 2c. In addition, the secretion property of the expression of VP2 protein may decrease the cost of production, because it can be skipped the cell breaking step. The produced VP2 protein could be used for vaccine and the agent of diagnostic tests. This study provides the foundation of the production of CPV 2c vaccine and the diagnostic agent.Keywords: baculovirus, canine parvovirus 2c, dog, Korea
Procedia PDF Downloads 151304 Identification of Two Novel Carbapenemase Gene Variants from a Carbapenem-Resistant Aeromonas Veronii Environmental Isolate
Authors: Rafael Estrada, Cristian Ruiz Rueda
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Carbapenems are last-resort antibiotics used in clinical settings to treat antibiotic-resistant bacterial infections. Thus, the emergence and spread of resistance to carbapenems is a major public health concern. Here, we have studied a carbapenem-resistant Aeromonas veronii strain previously isolated from a water sample from Sam Simeon Creek (Hearst San Simeon State Park, CA). Analysis of this isolate using disk-diffusion, CarbaNP, eCIM and mCIM assays revealed that it was resistant to amoxicillin-clavulanic acid and all carbapenems tested and that this isolate produced a potentially novel carbapenemase of the Metallo-β-lactamase family. Whole genome sequencing analysis revealed that this A. veronii isolate carries a novel variant of the blacₚₕₐ class β-carbapenemase gene that was closely related to the blacₚₕₐ₇ gene of Aeromonas jandaei. This isolate also carried a novel variant of the blaₒₓₐ class D carbapenemase gene that was most closely related to the blaₒₓₐ-₉₁₂ gene found in other Aeromonas veronii isolates. Finally, we also identified a novel class C β-lactamase gene moderately related to the blaFₒₓ-₁₇ gene of Providencia stuartii and other blaFₒₓ variants identified in Klebsiella pneumoniae, Escherichia coli and other Enterobacteriaceae. Overall, our findings reveal that environmental isolates are an important reservoir of multiple carbapenemases and other β-lactamases of clinical significance.Keywords: β-lactamases, carbapenem, antibiotic-resistant, aeromonas veronii
Procedia PDF Downloads 93303 Comparative Analysis of Local Acceptance of Renewable Energy Facilities and Spent Nuclear Fuel Repositories
Authors: Taehyun Kim, Hyunjoo Park, Taehyun Kim
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Public deliberation committee on Shin-Gori Nuclear Reactors No. 5 & 6 in South Korea recently suggested policy recommendation in July 2017 including complementary measures for resumption of construction: 1) nuclear power generation reduction, 2) expansion of investment to increase proportion of renewable energy, 3) repositories of spent nuclear fuel. Even when constructing eco-friendly renewable energy facilities such as solar and wind power plants, local residents are opposed to construction of these facilities due to environmental pollution and health impacts. In order to transform eco-friendly energy, it is necessary to convert nuclear energy into renewable energy and to take measures to increase the acceptance of residents through the participation of citizens. Therefore, this study aims to compare the factors of local acceptance of renewable energy facilities and spent nuclear fuel repositories through literature review and in-depth interview. The results show that environmental and economic concerns, risk perceptions, sociality, demographic characteristics and subjective recognition types affect the local acceptance for spent nuclear fuel repository. The factors of local acceptance for renewable energy facilities are partially coincide with those for spent nuclear fuel repository. The results of this study will contribute to improving residents' acceptance and reducing conflicts when determining the location of facilities in the future.Keywords: local acceptance, renewable energy facility, spent nuclear fuel repository, interview
Procedia PDF Downloads 302302 Polypeptide Modified Carbon Nanotubes – Mediated GFP Gene Transfection for H1299 Cells and Toxicity Assessment
Authors: Pei-Ying Lo, Jing-Hao Ciou, Kai-Cheng Yang, Jia-Huei Zheng, Shih-Hsiang Huang, Kuen-Chan Lee, Er-Chieh Cho
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As-produced CNTs are insoluble in all organic solvents and aqueous solutions have imposed limitations to the use of CNTs. Therefore, how to debundle carbon nanotubes and to modify them for further uses is an important issue. There are several methods for the dispersion of CNTs in water using covalent attachment of hydrophilic groups to the surface of tubes. These methods, however, alter the electronic structure of the nanotubes by disrupting the network of sp2 hybridized carbons. In order to keep the nanotubes’ intrinsic mechanical and electrical properties intact, non-covalent interactions are increasingly being explored as an alternative route for dispersion. Apart from conventional surfactants such as sodium dodecylsulfate (SDS) or sodium dodecylbenzenesulfonate (SDBS) which are highly effective in dispersing CNTs, biopolymers have received much attention as dispersing agents due to the anticipated biocompatibility of the dispersed CNTs. Also, The pyrenyl group is known to interact strongly with the basal plane of graphene via π-stacking. In this study, a highly re-dispersible biopolymer is reported for the synthesis of pyrene-modified poly-L-lysine (PBPL) and poly(D-Glu, D-Lys) (PGLP). To provide the evidence of the safety of the PBPL/CNT & PGLP/CNT materials we use in this study, H1299 and HCT116 cells were incubated with PBPL/CNT & PGLP/CNT materials for toxicity analysis, MTS assays. The results from MTS assays indicated that no significant cellular toxicity was shown in H1299 and HCT116 cells. Furthermore, the fluorescence marker fluorescein isothiocyanate (FITC) was added to PBPL & PGLP dispersions. From the fluorescent measurements showed that the chemical functionalisation of the PBPL/CNT & PGLP/CNT conjugates with the fluorescence marker were successful. The fluorescent PBPL/CNT & PGLP/CNT conjugates could find application in medical imaging. In the next step, the GFP gene is immobilized onto PBPL/CNT conjugates by introducing electrostatic interaction. GFP-transfected cells that emitted fluorescence were imaged and counted under a fluorescence microscope. Due to the unique biocompatibility of PBPL modified CNTs, the GFP gene could be transported into H1299 cells without using antibodies. The applicability of such soluble and chemically functionalised polypeptide/CNT conjugates in biomedicine is currently investigated. We expect that this polypeptide/CNT system will be a safe and multi-functional nanomedical delivery platform and contribute to future medical therapy.Keywords: carbon nanotube, nanotoxicology, GFP transfection, polypeptide/CNT hybrids
Procedia PDF Downloads 342301 Mining User-Generated Contents to Detect Service Failures with Topic Model
Authors: Kyung Bae Park, Sung Ho Ha
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Online user-generated contents (UGC) significantly change the way customers behave (e.g., shop, travel), and a pressing need to handle the overwhelmingly plethora amount of various UGC is one of the paramount issues for management. However, a current approach (e.g., sentiment analysis) is often ineffective for leveraging textual information to detect the problems or issues that a certain management suffers from. In this paper, we employ text mining of Latent Dirichlet Allocation (LDA) on a popular online review site dedicated to complaint from users. We find that the employed LDA efficiently detects customer complaints, and a further inspection with the visualization technique is effective to categorize the problems or issues. As such, management can identify the issues at stake and prioritize them accordingly in a timely manner given the limited amount of resources. The findings provide managerial insights into how analytics on social media can help maintain and improve their reputation management. Our interdisciplinary approach also highlights several insights by applying machine learning techniques in marketing research domain. On a broader technical note, this paper illustrates the details of how to implement LDA in R program from a beginning (data collection in R) to an end (LDA analysis in R) since the instruction is still largely undocumented. In this regard, it will help lower the boundary for interdisciplinary researcher to conduct related research.Keywords: latent dirichlet allocation, R program, text mining, topic model, user generated contents, visualization
Procedia PDF Downloads 187300 Geoplanology Modeling and Applications Engineering of Earth in Spatial Planning Related with Geological Hazard in Cilegon, Banten, Indonesia
Authors: Muhammad L. A. Dwiyoga
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The condition of a spatial land in the industrial park needs special attention to be studied more deeply. Geoplanology modeling can help arrange area according to his ability. This research method is to perform the analysis of remote sensing, Geographic Information System, and more comprehensive analysis to determine geological characteristics and the ability to land on the area of research and its relation to the geological disaster. Cilegon is part of Banten province located in western Java, and the direction of the north is the Strait of Borneo. While the southern part is bordering the Indian Ocean. Morphology study area is located in the highlands to low. In the highlands of identified potential landslide prone, whereas in low-lying areas of potential flooding. Moreover, in the study area has the potential prone to earthquakes, this is due to the proximity of enough research to Mount Krakatau and Subdcution Zone. From the results of this study show that the study area has a susceptibility to landslides located around the District Waringinkurung. While the region as a potential flood areas in the District of Cilegon and surrounding areas. Based on the seismic data, this area includes zones with a range of magnitude 1.5 to 5.5 magnitude at a depth of 1 to 60 Km. As for the ability of its territory, based on the analyzes and studies carried out the need for renewal of the map Spatial Plan that has been made, considering the development of a fairly rapid Cilegon area.Keywords: geoplanology, spatial plan, geological hazard, cilegon, Indonesia
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