• Annals of Occupational and Environmental Medicine
• /
• v.34
• /
• pp.11.1-11.9
• /
• 2022

Background: Although coronavirus disease 2019 is causing a variety of psychological problems for workers, there are few longitudinal studies on changes in workers' mental health by workplace intervention. This study aimed to evaluate the change in the prevalence of depression and anxiety according to the active involvement of the workplace. Methods: This study was conducted on 1,978 workers at a workplace who underwent a health screening from January 2019 to August 2020, and classified depression and anxiety disorders using a self-report questionnaire. After the first pandemic, the company stopped health screening, took paid leave and telecommuting, and conducted interventions such as operating its own screening clinic. To see if this workplace intervention affects workers' mental health, we conducted generalized estimating equations to compare odds ratio (OR). Results: In the pre-intervention group, 384 people (16.86%) had depression, and 507 people (22.26%) had anxiety disorder. Based on the OR before intervention, the OR of depression decreased to 0.76 (0.66-0.87) and the OR of anxiety disorder decreased to 0.73 (0.65-0.82). Conclusions: As a result of this study, it was confirmed that workplace intervention was related to a decrease in depression and anxiety. This study provides basic data to improve workers' mental health according to workplace intervention, and further research is needed according to workplace intervention in the future.

• Radiation Oncology Journal
• /
• v.33 no.4
• /
• pp.337-343
• /
• 2015

Purpose: The purpose of this report is to describe the proton therapy system at Samsung Medical Center (SMC-PTS) including the proton beam generator, irradiation system, patient positioning system, patient position verification system, respiratory gating system, and operating and safety control system, and review the current status of the SMC-PTS. Materials and Methods: The SMC-PTS has a cyclotron (230 MeV) and two treatment rooms: one treatment room is equipped with a multi-purpose nozzle and the other treatment room is equipped with a dedicated pencil beam scanning nozzle. The proton beam generator including the cyclotron and the energy selection system can lower the energy of protons down to 70 MeV from the maximum 230 MeV. Results: The multi-purpose nozzle can deliver both wobbling proton beam and active scanning proton beam, and a multi-leaf collimator has been installed in the downstream of the nozzle. The dedicated scanning nozzle can deliver active scanning proton beam with a helium gas filled pipe minimizing unnecessary interactions with the air in the beam path. The equipment was provided by Sumitomo Heavy Industries Ltd., RayStation from RaySearch Laboratories AB is the selected treatment planning system, and data management will be handled by the MOSAIQ system from Elekta AB. Conclusion: The SMC-PTS located in Seoul, Korea, is scheduled to begin treating cancer patients in 2015.

• Pediatric Gastroenterology, Hepatology & Nutrition
• /
• v.11 no.1
• /
• pp.28-35
• /
• 2008

Purpose: The aim of this study is to report the efficacy of infliximab, a monoclonal antibody directed against tumor necrosis factor alpha which is used for both treatment of refractory pediatric Crohn disease (CD) and induction of remission. Methods: Among pediatric patients who were diagnosed with CD at Samsung Medical Center between March 2001 and August 2007, a total of 16 patients were given infliximab to treat conventional therapyresistant refractory CD and severe active CD for induction of remission. Patients needing maintenance therapy were treated with an infliximab infusion every 8 weeks, and fistulizing CD patients occasionally received the infusion upon the condition that a fistula developed. The efficacy of treatment was assessed by comparing the Pediatric Crohn Disease Activity Index (PCDAI), Hct, ESR, CRP, and serum albumin levels using paired t-test. Results: The male/female ratio was 13:3, and the median age was 13 years (range, 21 months~15 years). The patients included 7 cases of therapy-resistant refractory CD, 7 cases of severe active CD, and 2 cases of fistulizing CD. Mean PCDAI before infliximab therapy was 34.19${\pm}$14.96, and mean follow-up PCDAI within 2 to 4 weeks after the last infusion was significantly lower, at 6.88${\pm}$10.31 (p=0.000). Hematological markers such as ESR (p=0.000), serum albumin (p=0.016), and CRP (p=0.009) also improved significantly after infusion. Remission was achieved in 2 of 4 patients refractory to conventional therapy. Among 3 steroid-dependent patients, 2 were able to discontinue steroid therapy, and dose reduction was possible in 1 patient. Remission after top-down therapy without prior use of other immunomodulators was achieved in 6 weeks in all 7 of the patients who had severe CD. Nine of ten refractory fistulizing CD patients also showed improvement after infliximab therapy. Conclusion: Infliximab was effective in pediatric refractory CD for induction of remission and maintenance therapy, as well as in severe CD for top-down induction therapy. Furthermore, infliximab has contributed to steroid cessation and dose reduction. Long-term follow-up evaluation is needed to determine safety and efficacy of infliximab in the future.

• Horticultural Science & Technology
• /
• v.28 no.4
• /
• pp.648-655
• /
• 2010

This study is the first comprehensive report on the molecular cloning, structural characterization, sequence comparison between wild and mutant types, copy number in the genome, expression features and activities of a gene encoding 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS) in Korean lawn grass ($Zoysia$ $japonica$). The full length cDNA of the EPSPS from Korean lawn grass ($zj$EPSPS) obtained from a 3' and 5' RACE method was 1540 bp, containing a 1176 bp ORF, a 144 bp leader sequence (5' UTR) and a 220 bp 3' UTR, which was eventually decoded 391 amino acid residues with a molecular mass of 41.74 kDa. The Southern blot detection of the $zj$EPSPS showed that the gene exists as a single copy in the Korean lawn grass genome. Sequence comparison of the $zj$EPSPS gene demonstrated that the glyphosate-tolerant mutant (GT) having a Pro-53 to Ser substitution in the gene seems to have a preferred binding activity of the enzyme to phosphoenol pyruvate(PEP) over glyphosate, which allows the continuous synthesis of aromatic amino acids in the shikimate pathway. From the Northern blotting analysis, the $zj$EPSPS was found to be highly expressed, with continuous increase until 36 hours after 0.5% glyphosate treatment in both wild and mutant samples, but 1.5-fold higher EPSP synthase activity was observed in the tolerant mutant when exposed to the glyphosate treatment. The molecular information of the $zj$EPSPS gene obtained from this study needs to be further dissected to be more effectively applied to the development of gene-specific DNA markers and zoysiagrass cultivars; nevertheless, the glyphosate-tolerant mutant having the featured $zj$EPSPS gene can be provided to turfgrass managers for weed problems with timely adoptable management options.

• Journal of the Korean Electrochemical Society
• /
• v.20 no.1
• /
• pp.7-12
• /
• 2017

Using a precursor of $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ as a starting material, a surface-modified cathode material was obtained by coating with KCl, where the added KCl reduces residual Li compounds such as $Li_2CO_3$ and LiOH, on the surface. The resulting electrochemical properties were investigated. The amounts of $Li_2CO_3$ and LiOH decreased from 8,464 ppm to 1,639 ppm and from 8,088 ppm to 6,287 ppm, respectively, with 1 wt% KCl added $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ that had been calcined at $800^{\circ}C$. X-ray diffraction results revealed that 1 wt% of KCl added $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ did not affect the parent structure but enhanced the development of hexagonal crystallites. Additionally, the charge transfer resistance ($R_{ct}$) decreased dramatically from $225{\Omega}$ to $99{\Omega}$, and the discharge capacity increased to 182.73mAh/g. Using atomic force microscopy, we observed that the surface area decreased by half because of the exothermic heat released by the Li residues. The reduced surface area protects the cathode material from reacting with the electrolyte and hinders the development of a solid electrolyte interphase (SEI) film on the surface of the oxide particles. Finally, we found that the introduction of KCl into $LiNi_{0.6}Co_{0.2}Mn_{0.2}O_2$ is a very effective method of enhancing the electrochemical properties of this active material by reducing the residual Li. To the best of our knowledge, this report is the first to demonstrate this phenomenon.

• Journal of Korean Society of Forest Science
• /
• v.55 no.1
• /
• pp.59-67
• /
• 1982

The objectives of this report is to evaluate the contribution of forest investments by the forest owners for the developments of private forests in the villages where the forest production, especially, chestnut production is active. The results obtained are as follows : 1) Newly purchased forest lands of 526 hectares, 71 percent, in 741 hectares by 96 farmers were replanted with chestnut trees for chestnut production. 2) As the chestnut production is considered to be the unique source of the early capital return in management of forests, selling and buying of forest lands in the area surveyed are enhanced to reforest the forest land with chestnut seedlings. 3) Most of new farmers being engaged in plantation and production of chestnuts in the forests are employees of private industries and government agencies, and merchants in neighboring towns. 4) All materials and expenses for formation of chestnut orchards are generally supplied by forest land owners. 5) Active buying and selling of newly established chestnut bushes are surely served as the estate in the area, thus, the trading of the bushes of young chestnut seedling also enhances the forest as the estate. 6) The management of forest established with chestnut orchards is a special form for forest investment, it makes possible to encourage imputing of capital to the new form of forests, chestnut orchards, and it could be a good possible model for private forest development as compared with that of government funding.

• Korean Journal of Heritage: History & Science
• /
• v.37
• /
• pp.327-348
• /
• 2004

In this study, after analyzing several local climate characteristics of South Korea, I validated distribution, invasion, foraging, underground activities, attack season as ecological characteristics and also temperature, relative humidity, and tree species as preference characteristics of Korean termites (Reticulitermes speratus kyushuensis Morimoto). Especially, southern part of the Korean peninsula is a suitable area for inhabitation and motion of termites holding same ecological characteristic like R. speratus kyushuensis. Busan is a neighboring district at field distribution north limiting temperature of Coptotermes formosanus Shiraki and Chuncheon is a passing area through the Korean Peninsula of field distribution north limiting temperature of Reticulitermes speratus Kolbe. The termite attack of wood devices was about 34.5% for 3 years in the forest of Jongmyo. Although the attack rate of termite increased each year, the detection rate decreased and the missing rate was high by degrees. I confirmed a foraging habits which is a part of termite colony was a role of continuous decomposition and another was a role of new food hunt as experimental results. The foraging termites were found under ground at Jongmyo in Seoul from April to November in the 2001 and the most active period was on July and August. The termite invasion rate of bait station increased in every monitoring. Through the increasing attack rate of bait station during 2nd monitoring (November, 2000) and 3rd monitoring(March, 2001), I confirmed that termites moved into the deep underground in winter, and were working continuously to forage. R. speratus kyushuensis inhabiting at the Korean Peninsula is a species which has food consumption rate with higher temperature. The termite revealed the greatest amount of food(filter paper) at $30^{\circ}C$(90% RH), but showed increasing death rate at over $32^{\circ}C$. Also, survival rate of this termite was 97% at 84% RH($30^{\circ}C$), but killed 100% at 52% RH($30^{\circ}C$) and 70% RH($30^{\circ}C$). For wood feeding, this was observed the preference in a pine tree(Pinus densiflora) above all others. Survival of termites was high(87%) at a pine tree, but low(13.5%) at a paulownia tree(Paulownia coreana). In this study, I presented the biological characteristic of termite(R. speratus kyushuensis Morimoto) and confirmed the deterioration degree of termite on wooden cultural heritage in Korea. Depending on climate and soil temperature, each area in the southern part of the Korea Peninsula, has some different active period and different distribution of R. speratus kyushensis. With these results, I expect that this report helps to prepare the integrated pest management(IPM) of the termite on wooden cultural heritage in Korea, and it may help to reduce the economical loss from termite damage in Korea.

• Journal of the Society of Disaster Information
• /
• v.16 no.3
• /
• pp.440-448
• /
• 2020

Purpose: Most of the studies in the country on earthquake-induced landslide predict the displacement of the slope. Until now, no studies have been conducted on the occurrence of landslides and damage characteristics by earthquakes. Therefore, this study was conducted to obtain basic data of landslides caused by earthquakes. Method: In order to analyze the characteristics of earthquake-causing landslides, we have collected data reported in the media over the past decade. Landslides in foreign countries were analyzed separately by cause of occurrences such as rainfall and earthquake. Landslides from abroad were analyzed according to the cause of the occurrence, and landslides caused by earthquakes were further analyzed as follows: the magnitude of an earthquake, year of occurrence, number of occurrences by continent, damage status, etc. Result: In the past 10 years, a total of 608 landslides have been reported from overseas, and the cause is the highest with 340 landslides due to rainfall. There were 70 cases of landslides caused by earthquakes, and it was analyzed as the second cause of landslides. The average magnitude for earthquakes that caused landslides was 6.5, and the minimum and maximum magnitude were 4.4 and 8.2 respectively. The earthquake-induced landslides were the most occurrence in 2011yr and 2012yr, and the continent was the most common in Asia. Also, It was analyzed that if an earthquake caused landslides, the number of casualties increased and the size of the damage increased. Conclusion: Currently, earthquakes are steadily increasing in Korea, and the possibility of strong earthquakes is also increasing. Earthquake-induced landslides are beyond human control due to natural disasters but can minimize damage through active prevention and response. It is expected that the results of this study will be used as basic data in establishing measures for earthquake landslides to reduce property and human damage in the future.

• The Korean Journal of Air & Space Law and Policy
• /
• v.33 no.1
• /
• pp.81-120
• /
• 2018

To promote the aviation safety reporting system that is operated to enhance aviation safety and to utilize related information, it should first be preceded by standards for non-punishment and data protection. It is because the purpose of collection and analysis of aviation safety related data through the aviation safety reporting system is to prevent recurrence of accidents by investigating their causes through collection and analysis of diverse types of information related to aviation safety. Both mandatory and voluntary reporting systems are in operation for aviation safety under the current Aviation Safety Act. It is said that they were introduced to survey causes for accidents and to prevent recurrences. In fact, however, it is hard to expect active implementation of the reporting system for aviation safety unless the reporters are firstly exempted from punishment. Therefore, the system should be improved so that it can satisfy its purpose and the purposes of data collection concerning aviation safety through examination of the purposes of the reporting system. One of the matters that needs to be considered to promote the reporting system should be the scope of aviation safety hindrances presupposed under the current institution. The voluntary aviation safety reporting system differs from the systems of ICAO or the key advanced countries, including the USA and the UK as it limits the target accidents subject to reporting to minor aviation safety hindrances only. That being said, improvements should be made by requiring mandatory reporting of aviation safety hindrances based on their severity while recognizing a greater variety of aviation safety concerns like international standards. Safety actions and sharing of information based on collection and analysis of diverse data related to aviation safety will greatly contribute to enhance aviation safety as the purposes of the reporting system are to explore causes for accidents and to prevent their recurrences. What is most important in this regard is strict data protection and non-punishment principles; compliance with them should be secured. We can hardly expect the successful operation of the system unless the reporter is exempted from punishment and the relevant data is protected as promotion of voluntary reporting is an essential factor for enhancing the safety culture. Otherwise, the current system may induce hiding of relevant facts or data to evade punishment. It is true that the regulation for enhancing safety tends to have limitations or blind spots; nevertheless, it should still be enforced strictly and completely. Technological progresses and mistakes of operators appear in different forms based on individual cases. The consequential damages may amount to a truly severe level. Therefore, we have studied and suggested to the methods of activiation and amendments on the aviation safety reporting system, which is referred for one of the proactive safety management systems. The proposed improvement of the reporting system and introduction of non-punishment for collection of aviation safety data for deploying a preemptive prevention system would serve as the backbone for enhancing aviation safety in Korea.

• Tuberculosis and Respiratory Diseases
• /
• v.45 no.3
• /
• pp.509-518
• /
• 1998

Background: Short-course chemotherapy for 6 months is well established for pulmonary tuberculosis. However, little is known about the efficacy of the short-course chemotherapy for tuberculous pleural effusion. Tuberculous pleural effusion itself may be self-limiting without any treatment, but about two thirds of the patients with tuberculous pleural effusion may subsequently develop pulmonary tuberculosis within 5 years. After completing treatment for tuberculous pleural effusion. prolonged follow-up is necessary for evaluating the efficacy of the treatment There is still no report on the efficacy of 6-month regimens for tuberculous pleural effusion in Korea, where the incidence of tuberculous disease and drug resistance is high. We studied the efficacy of 6 month short-course chemotherapy comparing with 9 month chemotherapy. Method : Retrospective study was done through medical record review in 238 patients with tuberculous pleural effusion who admitted to Asan Medical Center during May 1989-May 1993. The diagnosis of tuberculous pleural effusion was made by bacteriologic or histopathologic study. Results: Among 238 patients, 38 patients were dropped out during follow-up period. In 2 patients, second line drugs were prescribed according to known drug resistance results. And, in 23 patients, treatment longer than 9 months was done due to accompanying extrapulmonary tuberculosis or durg resistance. In 8 patients, treatment regimen was changed due to hepatotoxicity. Remaining 167 cases (70.2%) completed the treatment as scheduled ; 6 month chemotherapy in 88 cases and 9 month chemotherapy in 79 cases. In 60 patients (35.9%) with pleural effusion only in chest X-ray finding, sputum smear or culture for M.tuberculosis was positive in 6 cases (10.0%), and in 63 patients (37.7%) with radiologically inactive pulmonary tuberculosis, sputum smear or culture was positive in 18 cases (28.6%). In 44 patients (26.3%) with radiologically active pulmonary tuberculosis, the sputum smear or culture was positive in 24 cases (54.5%). In 6-month chemotherapy group (n=88), during mean 23 months (range; 1~61months) follow-up period, pulmonary tuberculosis developed in 1 case (1.4%). In 9-month chemotherapy group(n=79), during mean 23 months (range; 3~70months) follow-up period, pulmonary tuberculosis developed in 2 cases (2.5%). All the cases who developed pulmonary tuberculosis also showed active pulmonary tuberculosis on initial chest X-ray before treatment Conclusion: In patients with tuberculous pleural effusion, the incidence of pulmonary tuberculosis after 6 month chemotherapy showed no difference from that after 9 month chemotherapy. Thus, 6 month short-course chemotherapy seems to be an effective treatment for tuberculous pleural effusion.