• Proceedings of the Plant Resources Society of Korea Conference
• /
• 2020.12a
• /
• pp.15-15
• /
• 2020

In an internal document, CORONA-VIRUS DISEASE 2019 (COVID-19) PLAN, release developed stated that "on January 22, 2020, Palau Ministry of Health activated its emergency operations center, and since then has prepared and put in place measures in response to this global pandemic." The actions eventually led to the closure of most flights coming into Palau as a method to protect its population. The population of is at high risk with COVID19 due to the very elevated rate of NCD's, as well as the limited access to proper testing and treatment facilities. Increased use of traditional medicines in the population has reduced the co-morbidities by reducing risk factors. Furthermore, the expansion of tradtional NCD therapies, especially that of DAK reduce pressure due to obesity and diabetes therefore allowing for unimpaired immune systems to combat deadly infectious diseases such as COVID19.

• 전자공학회논문지 IE
• /
• v.44 no.3
• /
• pp.6-11
• /
• 2007

In this study, which was performed to identify a degradation mechanism in macromolecular insulating material, the contact angle, surface potential decay, surface resistance rate and XPS analysis were compared after exposure of fibre-glass-reinforced polymer laminate to plasma discharge. In the case of chemical changes arising from plasma treatment, carboxyl radicals were generated mainly in the plasma-treated surface, which was rapidly changed to a hydrophilic surface. In the corona potential decay study to determine the electrical changes, leading to a negative surface for the untreated specimen. However, in the case of the hydrophilic surface, a lot of carboxy radicals(-COO) acting as positive polarity were generated, resulting in a positive surface. Owing to such a positive surface, the charges of applied negative polarity were decreased rapidly.

• Restorative Dentistry and Endodontics
• /
• v.47 no.3
• /
• pp.28.1-28.12
• /
• 2022

Objectives: Metalloproteinase-inhibiting agents, such as chitosan, can prevent collagen degradation in demineralized dental substrates, thereby improving the adhesive interface. This study evaluated the bond strength (BS) and chemical and morphological characterization of the adhesive interface after applying chitosan solution to demineralized dentin. Materials and Methods: The 80 third molars were selected. Forty teeth underwent caries induction using the pH cycling method. The teeth were divided according to the treatment: distilled water (control) and 2.5% chitosan solution. The surfaces were restored using adhesive and composite resins. Half of the specimens in each group were aged, and the other half underwent immediate analyses. The teeth were sectioned and underwent the microtensile bond strength test (µTBS), and chemical and morphological analyses using energy-dispersive spectroscopy and scanning electron microscopy, respectively. Data analysis was performed using 3-way analysis of variance. Results: For µTBS, sound dentin was superior to demineralized dentin (p < 0.001), chitosan-treated specimens had higher bond strength than the untreated ones (p < 0.001), and those that underwent immediate analysis had higher values than the aged specimens (p = 0.019). No significant differences were observed in the chemical or morphological compositions. Conclusions: Chitosan treatment improved bond strength both immediately and after aging, even in demineralized dentin.

• Proceedings of the KWS Conference
• /
• 2002.10a
• /
• pp.53-58
• /
• 2002

Electrical insulation and mechanical properties of the plasma sprayed oxide ceramic coatings were studied before and after the sealing treatment of the ceramic coatings. Plasma sprayed A1$_2$O$_3$-TiO$_2$ coating as the reference coating was sealed using three commercial sealants based on polymer. Penetration depth of the sealants to the ceramic coating was evaluated directly from the optical microscope using a fluorescent dye. It is estimated that the penetration depth of the sealants to the ceramic coating is from 0.2 to 0.5 mm depending on the sealants used. The preliminary test results with a DC puncture tester imply that the dielectric breakdown voltage mechanism of plasma sprayed ceramic coatings has been determined to be a corona mechanism. Dielectric breakdown voltage of the as-sprayed and as-ground samples have shown a linear trend with regard to the thickness showing an average dielectric strength of 20 kV/mm for the thickness scale studied. It is also shown that grinding the coating before sealing and adding fluorescent dye do not agent the penetration depth of sealants. All of the microhardness, two-body abrasive wear resistance, bond strength, and surface roughness of the ceramic coating after the sealing treatment are improved. The extent of improvement is different from the sealants used. However, three-point bending stress of the ceramic coating after the sealing treatment is decreased. This is attributed to the reduced micro-crack toughening effect since the cracks propagate easily through the lamellar of the coating without crack deflection and/or branching after the sealing treatment.

• Polymer(Korea)
• /
• v.24 no.6
• /
• pp.869-876
• /
• 2000

In order to improve the cell-compatability of poly(L-lactide-co-glycolide) (75 : 25 by mole ratio of lactide to glycolide, PLGA) surfaces, the physicochemical treatments have been demonstrated. Chemical treatments were 70% perchloric acid. 50% sulfuric acid and 0.5 N sodium hydroxide solution and physical methods were corona and plasma treatment. The water contact angle of surface treated PLGA decreased from 73$^{\circ}$ to 50~60$^{\circ}$, i.e., increased hydrophilicity, due to the introduction of oxygen-containing functional group onto PLGA backbone by the measurement of an electron spectroscopy for chemical analysis. It could be observed that the adhesion and growth of fibroblast cell on physicochemically treated PLGA surfaces, especially perchloric acid treated PLGA surface, were more active than on the controt. In conclusion, it seems that surface wettability as hydrophilicity of PLGA plays an important role in cell adhesion, spreading and growth.

• The Journal of Internal Korean Medicine
• /
• v.30 no.3
• /
• pp.571-581
• /
• 2009

Background : Early in November 2002, severe acute respiratory syndrome (SARS) began to spread throughout thirty-two countries around the world. A total of 5,327 cases were reported in China, including 1,755 cases in Hong Kong and 655 in Taiwan. The total number of cases reported from Canada and Singapore was more than 200. The total number of SARS cases world-wide reached 8,437 with incidences. Mortality from SARS is estimated at around 11%. Under the guidance of the World Health Organization (WHO), clinical studies on the use of integrated herbal medicine and western medicine for treating SARS were carried out in China and Hong Kong. The official report suggested that integrated treatment was more effective than western medicine alone in clinical symptoms, lung inflammation, blood oxygen saturation, immunological functions and others. Objective : To overview the treatment principle and the prescriptions according to the regimens and the stages for SARS of the reports, and further to broaden our knowledge of treatment of acute infectious diseases using natural herbal medicine. Methods : We reviewed nine of WHO SARS reports that comprehensively described the principles and methods of treatment and summarized them into eight treatment methods. We analyzed the herbal formulae on the basis of their treatment principles, evaluated them in accordance with warm disease study, listed frequently used herbs, and assessed patent prescriptions and herbal injections that were mentioned in the reports. Results and Conclusion : The reports divided the course of SARS into 3 to 6 stages such as high fever stage, fastigium stage, and convalescent stage. Frequently used herbs were Radix Scutellariae, Radix Paeoniae, Radix Astragali, Semen Armeniacae, Radix Pseudostellariae, Radix Ophiopogonis, and Fructus Schizandrae. Herbal decoctions were the primary method of treatment, while extracts or injections were secondary. Prescriptions were mainly based on the warm disease study. SARS is a viral disease caused by corona virus, and herbal medicine is proven to be effective against it. We believe that evidences and experiences from SARS cases can be a good reference to further researches on acute infectious diseases.

• CELLMED
• /
• v.10 no.3
• /
• pp.24.1-24.6
• /
• 2020

Kushta Jast (KJ) is a unique herbo-mineral preparation of the Unani System of Medicine (USM) which is prepared by taklis (calcination) and prescribed by the practitioners of USM for the treatment of various ailments, including the respiratory ailments. It is used as muqawwi (tonic) to boost the immunity (Muqawwi-i-badan), and can increase the phagocyte activity of the immune cells, thereby, promoting the growth and spread of lymphocytes and increasing circulating antibodies to neutralize a harmful pathogen and reduce humma or body fever (Dafi'-i-humma). Incidentally, the principal mineral component of KJ, zinc, has been widely acknowledged for its beneficial influence on the immune function, and decrease the risk of developing serious respiratory illnesses. In this manuscript, we provide a glimpse of the literature on KJ and postulate its potential beneficial effects in respiratory infections, including COVID-19.

• Journal of Korean Society for Atmospheric Environment
• /
• v.12 no.4
• /
• pp.487-494
• /
• 1996

Simultaneous effects of $C_2H_4$ injection and heterogeneous chemical reactions on non-thermal plasma process to remove $SO_2$ and NOx from flue gas were investigated in the present experimental study. The present results showed that 40% of the electrical power can be reduced in $C_2H_4$ injection and heterogeneous chemical reaction are simultaneously included in the non-thermal plasma precess. As an effort to apply the non-thermal plasma technique to practical flue gas treatment system, a wire-plate type reactor which has technically similar geometry of industrial electrostatic precipitators is used instead of other types of reactors, such as wire-cylinder, packed-bed and surface discharge which are inappropriate to industrial application. In the present study, the photo pictures of positive streamer corona taken by ICCD camera, voltage and current oscillograms, and design criteria of a wire-plate type reactor are also shown, which are needed for industrial application of the non-thermal plasma process.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.07a
• /
• pp.942-945
• /
• 2000

Recently, electret applications have placed the focus on polymer thin film because electrical properties of a blend are studied. In this paper, we hale measured the infra sonic frequency by using Electret Sensor. Electret is formed by appling the voltage range of -4[kV] to -8[kV] to PTFE film and the sensor is manufactured by moment method to detect the infra-sonic signal. Electret Infrasonic Transducer, which is designed and manufactured by using of the moment method according to the potential and electric field simulation , shows its promising result, since the average rising rate of sensitivity is 7.68 [dB/oct] under 1[Hz], and the average values are within ${\pm}$ 1 [dB/oct]. As a result, it is believed that the characteristics of acquired transducer can be applied to the medical treatment, the industry, and the animal life researches, and also the study on noise elimination is required.

• International journal of advanced smart convergence
• /
• v.9 no.4
• /
• pp.132-138
• /
• 2020

Worldwide, the number of corona virus disease 2019 (COVID-19) confirmed cases is rapidly increasing. Although vaccines and treatments for COVID-19 are being developed, the disease is unlikely to disappear completely. By attaching a smart sensor to the respirator worn by medical staff, Internet of Things (IoT) technology and artificial intelligence (AI) technology can be used to automatically detect the medical staff's infection symptoms. In the case of medical staff showing symptoms of the disease, appropriate medical treatment can be provided to protect the staff from the greater risk. In this study, we design and develop a system that detects cough, a typical symptom of respiratory infectious diseases, by applying IoT technology and artificial technology to respiratory protection. Because the cough sound is distorted within the respirator, it is difficult to guarantee accuracy in the AI model learned from the general cough sound. Therefore, coughing and non-coughing sounds were recorded using a sensor attached to a respirator, and AI models were trained and performance evaluated with this data. Mel-spectrogram conversion method was used to efficiently classify sound data, and the developed cough recognition system had a sensitivity of 95.12% and a specificity of 100%, and an overall accuracy of 97.94%.