• 약학회지
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• 제35권6호
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• pp.522-529
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• 1991

The purpose of this research is to evaluate effects of chloramphenicol, phenobarbital and progesterone on damage of DNA, RNA and protein which was induced by dimethylnitrosamine. $N,N-Di[^{14}C]$ methyl-nitrosamine (DMN) was used as a damaging agent and levels of DNA, RNA and protein damage in liver, brain and pancreas were compared with a control group. Pretreatment of mice with chloramphenicol increased protein damage in pancreas two times more than the control level. Liver RNA damage was increased up to 5.8 times and brain DNA damage up to 6.95 times by treatment of phenobarbital but brain RNA damage was decreased significantly down to 21% of the control group. The damage of liver RNA was significantly decreased by treatment of progesterone, although liver protein damage, pancreas RNA damage and pancreas protein damage were increased.

• Geomechanics and Engineering
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• 제20권3호
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• pp.233-241
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• 2020

Alkali-silica reaction (ASR) is among one of the most important damaging mechanisms in concrete, depending primarily on aggregates which contain reactive minerals. However, expansion in concrete may not directly relate to the reactive minerals. This study aims to investigate the influence of ASR and the expansion of mortar bars depending on aggregate type containing various components such as quartz, clay minerals (montmorillonite and kaolinite) and micas (muscovite and biotite). In this study, the accelerated mortar bar tests (AMBT) were performed in two conditions (mortar bars in the same and sole NaOH solutions). Petrographic thin section studies, X-ray diffraction (XRD) analysis (Rietveld method), scanning electron microscopy (SEM) and chemical analyses were carried out. This study showed that quartzite bars led to increase in expansion values of mortar bars in diabase-1 and andesite when these were in the same NaOH solution. However, three samples (basalt, quartzite and claystone) were found having ASR expansion based on the AMBT when the special molds were used for each sample. SEM study revealed that samples which exhibit highest expansions according to AMBT had a generally rough surface and acicular microstructures in or around the micro-cracks. Basalt and quartzite showed more variable in major oxides than those of other samples based on the chemical analyses, SEM studies and AMBT. This study revealed that the highest expansions were observed to source not only from reactive aggregates but also from alteration products (silicification, chloritization, sericitization and argillisation), phyllosilicates (muscovite, biotite and vermiculite) and clays (montmorillonite and kaolinite).

• 한방안이비인후피부과학회지
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• 제17권2호
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• pp.59-71
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• 2004

Melanin pigmentation has an essential role in protecting human skin against the damaging effects of ultra violet radiation, infection, environmental factor, etc. However abnormal melanin pigmentation can directly cause a number of congenital and acquired pigmentary skin disease. This study conducted to evaluate the effects of various partition extracts of Codonopsis lanceolata on the melanogenesis in the B 16 melanoma cells. The cells were treated for 3 days with various partition extracts of Codonopsis lanceolata. While treatment with the BuOH partition extract of Codonopsis lanceolata increased significantly the tyrosinase activity and melanin content, the n-Hexane or ethyl acetate partition extract dose-dependently suppressed them compared with untreated control. But ethyl acetate partition significantly decreased the cell viability. The H2O partiton extract at various concentrations did not exhibit any significant change on the melanogenesis. These results indicate that treatment with the n-Hexane partition extract inhibits the melanogenesis in B16 melanoma cells, and raise the possibility that this extract may be effective in the abnormal melanin pigmentation as well as the whitening agent for the skin.

• Restorative Dentistry and Endodontics
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• 제38권3호
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• pp.105-112
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• 2013

While it is reasonably well known that certain dental procedures increase the temperature of the tooth's surface, of greater interest is their potential damaging effect on the pulp and tooth-supporting tissues. Previous studies have investigated the responses of the pulp, periodontal ligament, and alveolar bone to thermal irritation and the temperature at which thermal damage is initiated. There are also many in vitro studies that have measured the temperature increase of the pulp and tooth-supporting tissues during restorative and endodontic procedures. This review article provides an overview of studies measuring temperature increases in tooth structures during several restorative and endodontic procedures, and proposes clinical guidelines for reducing potential thermal hazards to the pulp and supporting tissues.

• Mycobiology
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• 제47권3호
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• pp.329-334
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• 2019

Streptomyces blastmyceticus strain 12-6 was isolated from a forest soil sample of Cheonan area on the basis of strong antifungal activities against plant pathogenic fungi. Butanol extracts of the cultural filtrates were active against C. acutatum, C. coccodes, C. gloeosporioides, F. oxysporum, and T. roseum. Active fractions were prepared by thin layer chromatography using silica gel plate; 12-6-2 ($R_f$ 0.36), 12-6-3 ($R_f$ 0.44). Scanning electron microscopy showed that the active fractions caused a change in surface texture of fungal spores from smooth surface to wrinkled surface. The lethal effect on the spores of the active fractions varied from 56% to 100%. It was shown that the spores of C. acutatum were more sensitive to the antifungal fractions than the spores of F. oxysporum. Fluorescence staining using TOTO-1 indicated that the antifungal fractions could make the spores more sensitive to the fluorescence dye. Thus, it was suggested that antifungal agents prepared in this study exhibited the antifungal activity by damaging the plasma membrane of both fungal spores and hyphae. Identification of antifungal agents in the active fraction using GC-MS analysis revealed the presence of cyclo-(Leu-Pro) and 9-octadecenamide as major components that have already been known as antifungal substances.

• Safety and Health at Work
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• 제7권2호
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• pp.138-142
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• 2016

Background: Household waste collectors (HWCs) are exposed to hazardous conditions. This study investigates the patterns of workplace injuries and work-related illnesses of HWCs. Methods: This study uses cases of workplace injuries and work-related illnesses of HWCs that occurred between 2010 and 2011. We analyzed 325 cases of injuries and 36 cases of illnesses according to the workers' age, length of employment, size of workplace, injured part of body, day and month of injury, type of accident, agency of accident, and collection process. Results: There were significant differences in the effect of workers' length of employment, injured part of body, type of accident, agency of accident, and collection process. Results show that most injuries occur in workers in their 50s and older. This study also shows that 51.4% of injuries occur at businesses with 49 employees or fewer. Injuries to waste collectors happen most often when workers are electrocuted after slipping on the ground. The second most prevalent form of injury is falling, which usually happens when workers hang from the rear of the truck during transportation or otherwise slip and fall from the truck. Work-related illnesses amongst waste collectors are mostly musculoskeletal conditions due to damaging postures. Conclusion: These findings will be instructive in devising policies and guidelines for preventing workplace injuries and work-related illnesses of HWCs.

• International Journal of Industrial Entomology and Biomaterials
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• 제38권1호
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• pp.1-5
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• 2019

Bee's population is declining and disappearing at alarming rate. There are many factors responsible for declining the population of bees including diseases, natural enemies, environmental conditions and pesticides. Insecticides play its role dramatically for their population decline and neonicotinoid insecticides are critically important due to their wide application for pest control. Keeping in view of above problem, effect of neonicotinoid insecticides on olfactory learning behavior in Apis mellifera was observed using Proboscis Extension Reflex (PER) method. In this method, bees were harnessed in centrifuges tubes and feed on insecticides mixed sugar solution after three hours hunger. Bees were checked by feeding on non-treated sugar solution to observe PER response. Minimum proboscis extension was observed for acetamiprid and imidacloprid with 26% and 20% respectively at their recommend field doses while it was maximum for dinotefuran and thiamethoxam with 73% and 60% respectively. Only 40% bees showed response when exposed at 1/10 concentration of field dose for imidacloprid and the least at 1/100 of field dose. At control (Sugar solution) about 90% bees showed PER response. Among these neonicotinoid insecticides tested, imidacloprid and acetamiprid were the most damaging which impaired the olfactory learning performance in Apis mellifera.

• 한국농업기계학회:학술대회논문집
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• 한국농업기계학회 1993년도 Proceedings of International Conference for Agricultural Machinery and Process Engineering
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• pp.922-931
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• 1993

Boundary element method was used to solve heat conduction problem for predicting temperature distribution in grain storage bin. Temperature of grain in storage is one of the three main abiotic factors, besides the intergranular gas composition and the grain moisture content, that determine the keeping quality and control measures used to protect grain from insects and damaging microflora. Collecting the temperature data at various points in the storage bins at different time of the day over a period of time is one way of finding the temperature distribution, this method requires a lot of time, cost and labour and less efficient. However data so collected serve useful purpose of being used to validate predicted temperature distribution using mathematical models. Mathematical models based on physical principles can potentially predict with accuracy the temperature distribution in a grain storage bin. Using the boundary element model the effect of bin wall material, ambient emperature, bin size etc. on temperature distribution can be studied. A knowledge of temperature distribution in stored grain not only helps in identifying active deterioration , but also gives an indication of potential for detection.

• 한국식품영양과학회지
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• 제23권6호
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• pp.899-907
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• 1994

Accumulation of peroxidized lipid, fed or injected in the body of rats was investigated and the effect of peroxidized lipid on the antioxidative system was studied also. Three groups each having six of Sprague-dawley rats were raised for 8 weeks. the peroxide value(POV) of diet fed to the control and the peroxidized group was 5.47 and 22.14meq/kg , respectively. Injected group was given the control diet and peroxidized linoleic acid(POV 31.81meq/kg) was injected into the peritoneal area three times a week. The POV, MDA, and protein carbonyl values of the peroxidized and the injected group (experimental groups) were significantly higher (p<0.05) than those of the control group. Cu, Zn-SOD and M-SOD activity of the experimentla groups increased 1.6 times that of control group at 4 th week. and decreased by 60% of their activityafter 8 weeks of feeding (p<0.05) . Catalase activity, glutathione and Vt, E contents of the experimental groups were significantly lower (p<0.05) than those of the control group during 8 weeks. The accumulation of peroxidcized lipid in liver were ovserved both in the fed or the injected group. The increased of enzyme activity of the experimental group during 4 weeks suggests ianadaptation of antioxidative system to get rid of the peroxidized lipid. Decrease of enzyme activity and glutathione observed as the peroxidized lipid lipid accumulation proceeded further, however, seems to indicate the oxdiative damage of enzyme and protein . Determination of the protein carbonyl content may be used as a method for measuring the oxidative damaging effect of peroxidized lipid.

• 대한한방부인과학회지
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• 제21권1호
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• pp.257-266
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• 2008

Purpose: These experiments were undertaken to evaluate the effect of Onpoeum on ovarian functions and differential gene expressions related with cell viabilities caspase-3, MAPK and MPG in female mice. Methods: We administered the Onpoeum to 6-week-old female ICR mice for 4, 8, or 12 days. With different concentration of Onpoeum, the female mice were injected PMSG and hCG for ovarian hyperstimulation. The mice divided into 3 different groups for each experiment. We chose the Caspase-3 for cell apoptosis, MAPK and MPG genes for cell viability and DNA repair. Results: In case of 4, 8, 12 day of Onpoeum, we were examined the mean number of total ovulated oocytes and the number of morphologically normal oocytes. We were also examined the embryonic developmental competence in vitro. In addition we were examined the differential expression of cell apoptosis, viability and DNA repair related genes, Caspase-3, MAPK and MPG according to concentration and duration of Onpoeum. From these results showed that the administration of Onpoeum played a role of prevention of cell apoptosis and DNA damages and also increased cell proliferation resulted in ovarian functions. Conclusions: It is suggested that the medication of Onpoeum may have beneficial effect on reproductive functions of female mice via prevention of cell apoptosis and DNA damaging and promotion of cell proliferation.