• Research in Plant Disease
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• v.13 no.1
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• pp.34-39
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• 2007

Lichen thalli of Dirinaria applanata heavily colonized on the twigs of dead or dying Rhododendron trees in Solok island, Jeonnam province in Korea. Pathogenesis of the lichen on the trees was investigated to find out the possibility of lichen as a causal agent. Histological examination of the lichen colonized twigs was attempted with differential staining technique. Lichen-forming fungus colonized only on the surface of bark and there was no direct penetration of fungal hyphae into the plant tissues. Symbiotic algae of the lichen was also examined. The isolated algal cells were inoculated on artificially induced wounds of the healthy trees. Histological examination of the inoculated tissues showed that some algal cells were successfully colonized inside the tissues without any pathogenic symptoms, even 2 months later, The extract of the lichen thalli was also examined using 10% of DMSO solution. Treated tissues showed no pathogenic symptoms, even 4 weeks later. The results suggested that the lichen was not directly involved in the death of the trees.

• Research in Plant Disease
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• v.23 no.2
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• pp.114-149
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• 2017

World-wide crop loss caused by insect pest and nematode reaches critical level. In Korea, similar crop loss has been gradually augmented in the field and greenhouse due to continuous crop rotation. The current methods on controlling herbivorous insects and plant parasitic nematodes are mostly depended on agro-chemicals that have resulted additional side-effect including occurrence of resistant insects and nematodes, environmental contamination, and accumulation in human body. To overcome the pitfalls, microbe-based control method have been introduced and applied for several decades. Here, we revised biological control using by the bacteria, fungi, and virus in order to kill insect and nematode and to attenuate its virulence mechanism. The introduced microbes mainly secreted out the hydrolysing enzymes and toxic compounds to target host membrane or cell wall directly. Indirectly, the microbe-triggered plant innate immunity against insects and nematodes was also reported. In conclusion, we provide a new frontier of microbe-based environmentally friendly procedure and effective methods to manage insects and nematodes.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.25 no.2
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• pp.202-210
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• 2015

Objectives: The purpose of this study was to examine clean room(C/R) structure, air conditioning and contamination control systems and to provide basic information for identifying a correlation between the semiconductor work environment and workers' disease. Methods: This study was conducted at 200 mm and 300 mm semiconductor wafer fabrication facilities. The C/R structure and air conditioning method were investigated using basic engineering data from documentation for C/R construction. Furthermore, contamination parameters such as airborne particles, temperature, humidity, acids, ammonia, organic compounds, and vibration in the C/R were based on the International Technology Roadmap for Semiconductors(ITRS). The properties of contamination control systems and the current status of monitoring of various contaminants in the C/R were investigated. Results: 200 mm and 300 mm wafer fabrication facilities were divided into fab(C/R) and sub fab(Plenum), and fab, clean sub fab and facility sub fab, respectively. Fresh air(FA) is supplied in the plenum or clean sub fab by the outdoor air handling unit system which purifies outdoor air. FA supply or contaminated indoor air ventilation rates in the 200 mm and 300 mm wafer fabrication facilities are approximately 10-25%. Furthermore, semiconductor clean rooms strictly controlled airborne particles(${\leq}1,000{\sharp}/ft^3$), temperature($23{\pm}0.5^{\circ}C$), humidity($45{\pm}5%$), air velocity(0.4 m/s), air change(60-80 cycles/hr), vibration(${\leq}1cm/s^2$), and differential pressure(atmospheric pressure$+1.0-2.5mmH_2O$) through air handling and contamination control systems. In addition, acids, alkali and ozone are managed at less than internal criteria by chemical filters. Conclusions: Semiconductor clean rooms can be a pleasant environment for workers as well as semiconductor devices. However, based on the precautionary principle, it may be necessary to continuously improve semiconductor processes and the work environment.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.27 no.4
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• pp.302-312
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• 2017

Objectives: In this study, an evaluation of the working environment of furnace workers was performed and the work-relatedness of the occupational diseases were examined Methods: In this study, two electric furnaces at a single casting business site producing manganese-based iron alloy were selected, and occupational exposures to hazardous substances were evaluated for furnace workers and furnace worker assistants. Results: As a result, total dust concentration were $0.407{\sim}3.001mg/m^3$ and respirable dust concentration were $0.196{\sim}0.584mg/m^3$. The highest concentration of crystalline silica was $0.079mg/m^3$ In the case of Masato and Sosuckwhoi crystalline silica, they contained 90.85% and 4.17% respectively. Manganese concentration was the highest at a $0.205mg/m^3$ maximum. The average of black carbon is $11.56{\mu}g/m^3$ and the maximum concentration is $604.23{\mu}g/m^3$. PAHs concentration was the highest at a $78.301{\mu}g/m^3$ of naphthalene. The concentration of carbon monoxide was 18.82 ppm(total average 3.89 ppm) during pouring, and the maximum is 131 ppm. The formaldehyde concentration was 0.003 to 0.007 ppm. Conclusions: It seems that conditions in the past were worse, since casting has recently been performed only twice per day for about 20 minutes, reducing the amount of pouring, and local exhaust systems have been installed one-by-one. In addition, it was judged that the past exposure levels were higher considering the points measured on the back-side due to the risk of damage to the individual samples. It was found that operators could be exposed to high concentrations of crystalline silica, and that they were also exposed to high concentrations of metal(fume) and carbon monoxide during pouring. Therefore, there is a risk that occupational diseases such as lung cancer and COPD may occur with long-term work in such a process.

• Journal of Animal Science and Technology
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• v.46 no.4
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• pp.517-524
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• 2004

The objective of this study was to investigate the environmental effects on duration time of milk flow, peak milk flow, and average milk flow in teats, and to estimate their relationships with milk yields in morning and evening milking, and to provide fimdamental information for the further study on their relationships with clinical mastitis and somatic cell in milk. A total of 6,768 milking records were studied in 72 Holstein cows. The influences of season, parity, lactation month, and milking interval on characteristics of milk flow considering in linear model were significant(p<.05). Duration of milk flow was longest at milking in fall, past first parity and second month of lactation, and with milking interval over than 13.5hrs. Average milk flow rate and peak milk flow rate were highest at milking in summer, past first parity and 8${\sim}$10 months of lactation, and with milking interval over than 13.5hrs. Milk flow rate was positively correlated to milk yield, and negatively correlated to the duration of milk flow. However duration milk flow was positively correlated to the milk yield with high level of correlation coefficient(+.60). For the establishment of optimum selection criteria on these traits, other aspects such as the udder health, disease and respective economic weights of milk flow characteristics in this study must be considered to develop the indices.

• Journal of Korean society of Dental Hygiene
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• v.7 no.4
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• pp.455-470
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• 2007

The usage of appropriate disinfectants is essential for infection control in dental hospitals, dental clinics. Inadequate use of disinfectants is the cause of human or environmental toxicity and is a waste of cost. This study was aimed to assess the level of knowledge on the disinfection and chemical disinfectants among dental workers in dental hospitals, dental clinics. It's ultimately intended to serve as a basis for the preparation of more effective, appropriate educational programs on the disinfection and manuals on the use of disinfectants for dental workers. This study enforced a questionnaire with 184 dental workers employed in dental hospitals, dental clinics from 15 Aug. to 15 Sep. 2007, in the area of Daejeon. The obtained result were as follows; 1. The population sociological feature of dental hospital and dental clinic showed that significant differences of dental service career(pM0.039). Dental service career of dental workers shows; below 3 years 42.9%, 4~6 years 34.7%, more than 7 years 22.4% in dental hospitals, below 3 years 30.4%, 4~6 years 26.7%, more than 7 years 43.0% in dental clinics(pM0.039). 2. The average score of dental workers knowledge in 'Critical item soaks in high-level disinfectants for 20minutes was 2.73V0.49 point, got from knowledge of dental instrument is appropriate to immerse before sterilization in the dental device disinfection(pM0.002). 3. In the general disinfection which it follows in education experience of chemical disinfectants direction for use, 'Direction for use by Spaulding process classification' responded that the correct answer was the education experience dental workers 60.0%, the education non-experience dental workers 39.5%(p=0.026). 4. In the dental device disinfection which it follows in education experience of chemical disinfectants direction for use. 'High level disinfection is not applied for the non-critical items and equipment' responded that the education experience dental workers 49.2%, the education non-experience dental workers 31.9%(pM0.045), 'Semi-critical items is applied same method in presence of the infection disease which it acts responded that the education experience dental workers 44.6% answer back, the education non-experience dental workers 24.4%(pM0.017). 5. 'A hand disinfectants of anticeptics have effect' the education experience dental workers 78.5% answer back, the education non-experience dental workers 52.9%(pM0.003). 1t uses with hand disinfectants when the instruments which be imbrued and patient contact', the education experience dental workers 78.5% answer back, the education non-experience dental workers 62.2%(pM0.026), 'Boric acid solution uses for the skin disinfectants the education experience dental workers 52.3% answer back, the education non-experience dental workers is 37.0%(pM0.016), 'Gluconate have effective difference which it follows in chemical disinfectant consistency and the solution type' education experience dental workers 72.3% answer back, education non-experience dental workers 47.9%(pM0.004). 6. The education experience dental workers were appeared higher than the education non-experience dental workers in knowledge of the disinfection and chemical disinfectants. Consequently system and the specialty education which is standardized continuously must be provided to all dental workers.

• The Korean Journal of Mycology
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• v.44 no.4
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• pp.330-337
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• 2016

Streptomyces sp. A75 and A501 inhibited the mycelial growth of pathogenic Rhizoctonia solani and Pythium sp., which cause the ginseng disease known as damping-off. Three methods were evaluated for the control of these pathogens, using a mixture of the culture broths from Streptomyces sp. A75 and A501. The methods tested were seed dipping with 50-fold diluted broth, drenching of soil with 100-fold diluted broth after sowing, and combined seed dipping and drenching. These methods reduced the incidence of ginseng damping-off caused by R. solani by 81.3%, 84.8%, and 32.2% and that caused by Pythium sp. by 51.0%, 52.1%, and 75.3%, respectively. Based on these results, the combination of seed dipping and soil drenching after sowing using a mixture of the culture broths from Streptomyces sp. A75 and A501 effectively reduced the incidence of damping-off in ginseng.

• The Korean Journal of Pain
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• v.6 no.2
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• pp.208-212
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• 1993

Allergy is one of the most common intractable disease, and also allergic rhinitis is the common symptom of the allergic diseases encountered in the otolaryngologic department. There are number of treatment such as: allergen avoidance by environmental control, pharmacotherapy, allergen immunotherapy and more. But choosing the exact reguired treatment is very difficult and troublesome. During the past 3 years, we have provided treatments to 49 allergic rhinitis patients with the combined therapy of stellate ganglion block(SGB) and eletrical acupuncture(E-AP) with very good results. From our experiences we highly recommend the combined therapy with SGB and E-AP for allergic rhinitis.

• Journal of Environmental Policy
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• v.8 no.3
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• pp.53-79
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• 2009

This study conducted a regulatory impact analysis regarding the introduction of the Korean version of REACH(Registration, Evaluation and Authorization of Chemicals). The direct cost of the Korean REACH is estimated at a total of 101 billion Korean won over the 11 year period. The cost includes pre-registration, testing, registration, Chemical Safety Assessment(CSA) and Chemical Safety Report(CSR), evaluation, and the authorization costs of 15,223 chemical substances produced and imported more than 1 ton per year in Korea in 2006. With regard to the benefit, the only public health benefit is included in the estimation. Based on the available foreign and domestic data, this study estimated that the economic values of public health benefits are in the range of 33.2~138.6 billion Korean won if only the savings of the National Health Expenditures are considered and it reaches 203.9~1,640.3 billion Korean won if the willingness to pay(WTP) for disease prevention is included. This study proved that the Korean REACH passed the cost/benefit criteria. The benefit-cost ratio of the Korean REACH, however, is estimated to be lower than its EU counterpart. Thus it is suggested that a rigorous study to reduce the costs to industry be required before the Korean government introduces the Korean REACH.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.3
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• pp.392-398
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• 2010

This study was conducted to investigate housewives' purchase behavior and needs for information on food safety. The data were collected from 275 housewives over the age of 20 living in Seoul and metropolitan areas from March 9 to April 3 in 2009. The result of this study showed that 'checking expiration date' topped with 4.59 in the purchase behavior for food safety followed by 'buying domestics' (4.08) and 'considering food safety' (3.66). The study also showed that only 18.5% of the respondents said that they have an experience of education for food safety, and 'environmental hormones' was the highest with 89.1% in the percentage of correct answer but 'mad cow disease' was the lowest with 25.8%. Also total degree of knowledge for food hazards was an average of 8.56 out of 13. The respondents' degree of information search for food safety was generally low at 2.61 and tv/radio topped the list of information sources with 4.04, followed by newspaper/magazine (3.80), internet (3.44), and family/relatives/friends (3.39). Finally, degree of information needs for food safety was generally high with 3.82. Therefore, government, producers, distributers and academic researchers must provide consumers collective and sufficient information about the food safety and hazards through the diverse information sources. Also they have to play their respective roles in developing and executing feasible education program for consumers.