• 한국콘텐츠학회논문지
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• 제13권1호
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• pp.342-353
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• 2013

본 연구는 마음수련명상의 지속기간에 따른 정신건강의 차이를 비교분석하기 위한 것이다. 단기집중 마음수련명상의 효과를 파악하기 위한 단일군 전후 원시실험연구와 지속적 마음수련명상의 효과를 파악하기 위한 서술적 조사연구로 구성된다. 자료 수집 및 대상은 단기집중 마음수련명상군의 경우 2011년 7월 23일부터 7월 30일, 2012년 1월 7일부터 1월 14일에 마음수련명상 프로그램에 참여한 교사들 75명을 대상으로 프로그램 실시 전후에 구조화된 설문지를 이용하여 자료 수집을 하였고, 지속적 마음수련명상군의 경우 2012년 2월 현재 마음수련명상을 1년 이상 지속한 교사들 101명을 대상으로 2012년 2월 15일에서 2월 28일까지 자료 수집을 하였다. 자료 분석은 SPSS WIN 14.0를 이용하였으며 연구결과는 다음과 같다. 단기집중 마음수련명상군의 경우 마음수련명상 전후에 정신건강의 모든 하위영역(신체화, 강박증, 대인예민성, 우울, 불안, 적대감, 공포불안, 편집증, 정신증)에서 유의한 차이가 있었다. 지속적 마음수련명상군의 지속기간에 따른 정신건강 정도는 편집증을 제외한 8개 영역(신체화, 강박증, 대인예민성, 우울, 불안, 적대감, 공포불안, 정신증)에서 모두 유의한 차이를 보였다. 결론적으로 마음수련명상이 단기적, 지속적 중재 모두에 효과가 있는 것으로 보아 임상에서의 단기적용과 스트레스 대처능력을 기르기 위한 지속적인 프로그램으로서 개발과 적용이 필요하다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제37권5호
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• pp.406-414
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• 2011

Thermally induced bone necrosis during implant surgery is a rare phenomenon and a potential contributing factor to implant failure. The frictional heat generated at the time of surgery causes a certain degree of necrosis of the surrounding differentiated and undifferentiated cells. The bone necrosis occurred in the mandible in all three cases, leading to a soft tissue lesion and pain. In each case, radiolucent areas appeared in the middle and apical portions of the implant 4 weeks after surgery. Thermally induced bone necrosis did not improve following systemic antibiotic medication, necessitating surgical treatment. The nonintegrated implants were removed, and meticulous debridement of dead bone and granulation tissue was performed. Then, new implants were implanted along with the placement of autogenous and xenogenic bone covered with a collagen membrane. No further complications occurred after re-operation. The radiolucencies around the new implants gradually resolved entirely, and the soft tissue lesions healed successfully. At 4-5 months after reoperation, implant loading was initiated and the implant-supported restorations have been functioning. The aim of this case report is to present the successful clinical treatment of three cases suspected to be caused by thermally induced bone necrosis after implant drilling.

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.77-86
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• 2002

Current composites are made with dimethacrylate monomers and silane-treated silica microfillers, either alone or with silane treated glass fillers The main reasons for clinical failure of dental composites are secondary caries, wear and fracture. Most of practitioner want to get a composite which is more tougher under occlusal stress, less polymerization contraction, and better handling properties in application clinically. The aim of this study was to investigate the influence of resin matrix with various flows on the physical proper-ties such as fracture toughness and degree of conversion of the experimental resins. It was hypothesized that flexible or tough resin composites can be designed by judicious choice of monomer composition Various flow resin matrices containing Bis-GMA, UDMA, and TEG-DMA were made by altering the pro-portion of the monomers. After the unfilled resins were light-cured for different light intensity, the fracture toughness(K$_{1c}$) was measured according to ASTM standard using the single edge notched geometry, and degree of conversion(DC) was measured by FTIR. And experimental composites were formulated with variations in the proportion of silanated quartz and strontium glass fillers as 60, 75, and 77wt%. Also, the physical properties of composites with various filer contents were evaluated as same manner. All resulting data were compared by ANOVA/Tukeys test at 0.05 level. The results were as follows; 1. The degree of conversion of high flow resin containing less Bis-GMA was higher than that of low flow unfilled resin 2. While the degree of conversion of unfilled resin was increased according to light intensity for polymerization, there was no significant increase with moderate and high light intensity. Also, the fracture toughness was not increased by high light intensity. 3. The fracture toughness was high in the low flow unfilled resin containing higher contents of Bis-GMA. 4. There was a significant increase for fracture toughness and a tendency for degree of conversion to be reduced when the content of fillers was increased. 5. In the experimental composites, the flow of resin matrix did not affected on the fracture toughness, even, which was decreased as increase of viscosity. These results showed that the physical properties of a dental composite could be attributed to the flow of resin matrix with relative content of monomers. Specific combination of resin monomers should be designed to fulfil the needs of specific indication for use.

• Toxicological Research
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• 제33권3호
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• pp.239-253
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• 2017

Neodymium is a future-oriented material due to its unique properties, and its use is increasing in various industrial fields worldwide. However, the toxicity caused by repeated exposure to this metal has not been studied in detail thus far. The present study was carried out to investigate the potential inhalation toxicity of nano-sized neodymium oxide ($Nd_2O_3$) following a 28-day repeated inhalation exposure in male Sprague-Dawley rats. Male rats were exposed to nano-sized $Nd_2O_3-containing$ aerosols via a nose-only inhalation system at doses of $0mg/m^3$, $0.5mg/m^3$, $2.5mg/m^3$, and $10mg/m^3$ for 6 hr/day, 5 days/week over a 28-day period, followed by a 28-day recovery period. During the experimental period, clinical signs, body weight, hematologic parameters, serum biochemical parameters, necropsy findings, organ weight, and histopathological findings were examined; neodymium distribution in the major organs and blood, bronchoalveolar lavage fluid (BALF), and oxidative stress in lung tissues were analyzed. Most of the neodymium was found to be deposited in lung tissues, showing a dose-dependent relationship. Infiltration of inflammatory cells and pulmonary alveolar proteinosis (PAP) were the main observations of lung histopathology. Infiltration of inflammatory cells was observed in the $2.5mg/m^3$ and higher dose treatment groups. PAP was observed in all treatment groups accompanied by an increase in lung weight, but was observed to a lesser extent in the $0.5mg/m^3$ treatment group. In BALF analysis, total cell counts, including macrophages and neutrophils, lactate dehydrogenase, albumin, interleukin-6, and tumor necrosis factor-alpha, increased significantly in all treatment groups. After a 4-week recovery period, these changes were generally reversed in the $0.5mg/m^3$ group, but were exacerbated in the $10mg/m^3$ group. The lowest-observed-adverse-effect concentration of nano-sized $Nd_2O_3$ was determined to be $0.5mg/m^3$, and the target organ was determined to be the lung, under the present experimental conditions in male rats.

• Journal of Preventive Medicine and Public Health
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• 제50권1호
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• pp.1-9
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• 2017

Objectives: By the end of the 2000s, the economic situation in many European countries started to deteriorate, generating financial uncertainty, social insecurity and worse health status. The aim of the present study was to investigate how the recent financial crisis has affected the lifestyle health determinants and behaviours of older adults living in the Mediterranean islands. Methods: From 2005 to 2015, a population-based, multi-stage convenience sampling method was used to voluntarily enrol 2749 older adults (50% men) from 20 Mediterranean islands and the rural area of the Mani peninsula. Lifestyle status was evaluated as the cumulative score of four components (range, 0 to 6), that is, smoking habits, diet quality (MedDietScore), depression status (Geriatric Depression Scale) and physical activity. Results: Older Mediterranean people enrolled in the study from 2009 onwards showed social isolation and increased smoking, were more prone to depressive symptoms, and adopted less healthy dietary habits, as compared to their counterparts participating earlier in the study (p<0.05), irrespective of age, gender, several clinical characteristics, or socioeconomic status of the participants (an almost 50% adjusted increase in the lifestyle score from before 2009 to after 2009, p<0.001). Conclusions: A shift towards less healthy behaviours was noticeable after the economic crisis had commenced. Public health interventions should focus on older adults, particularly of lower socioeconomic levels, in order to effectively reduce the burden of cardiometabolic disease at the population level.

• Toxicological Research
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• 제17권3호
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• pp.187-194
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• 2001

The oxidative stress causes the cell damage and death and thereby, stimulates membrane lipid peroxidation. In this study, the correlation between the lipid peroxidation product and the parameter of liver fibrosis (cirrhosis) was investigated in cholestasis induced rats. The Sprague-Dawley rats were divided into 3 groups (sham: sham operation, BDL/S-I and BDL/S-II : bile duct ligation/scission) and were observed for 2 or 4 weeks. After observation period, the organs were weighed and the ratio of organ weight/body weight was calculated. Sera and liver tissue were used for the measurement of malondealdehyde (MDA), parameter of clinical biochemistry, total collagen content and the staining. The ratio of organ weight/body weight in BDL/S-I and BDL/S-II was significantly increased compared to sham operated group. Serological parameters (Alanine transaminase, Aspartate transaminase, Alkaline phosphatase and Total bilirubin) in BDL/S-I and BDL/S-II group were significantly higher than those in sham operated group. Concentration of MDA in BDL/S-I (261%) and BDL/S-II(790%) was significantly increased compared to MDA in sham operated group. And the content of hydroxyproline (hyp) in BDL/S-I and BDL/S-II group was significantly increased 2~4 times than in sham operated group. The good correlations between hyp in liver tissue and MDA in sera of sham operated group and all operated group were found (r=0.825). The significantly higher value of MDA, hyp and serological parameters in BDL/S-I and BDL/S-II group suggests the stimulation of lipid peroxidation and chronic liver damage. Especially the activation of lipid peroxidation and the stimulation of liver fibrosis was stronger in BDL/S-II group than in BDL/S-I group. The stronger fibrosis, portal-portal septum formation, the more massive bile duct proliferation in portal triads and stroma, and hepatocytes swelling were observed in liver tissue of and BDL/S-II group compared to BDL/S-I group. Conclusively, a good correlation between MDA as a lipid peroxidation marker and hyp as a liver fibrotic parameter could be connected with the process of liver fibrosis. Moreover, cholestasis condition may cause jaundice, activation of lipid peroxidation, and collagen accumulation in liver. Additionally, optimal observation period of bile duct obstruction for the screening of antioxidant and antifibrotic effect in rats would be four weeks.

• 한국식품위생안전성학회지
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• 제13권2호
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• pp.171-187
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• 1998

Garlic occupies a special position among the many foods of vegetable origin because it is the sole food for Koreans during the their lives. And vitamin A has been ingested by forms of food or additives. Cadmium has been described as one of the most dangerous trace elements in the food and environment of man and livestocks. Since the de novo synthesis of stress proteins can be detected early after exposure to some agents, analysis of cadmium-induced changes in gene expression , ie. alterations in patterns of protein synthesis, may be useful to develop as biomarkers of exposure and damage for food hygiene. He acute and chronic combine effects of cadmium (Cd, CdCl2 20mg/kg), garlic oil(Dds: diallyl disulfide 50mg/kg, 3 times a week) and vitamin A(Ra: retinol acetate 50,000 IU/kg, 3 times a week) on Wistar male rats were evaluated concerning cadmium contents, tissues enzyme activity, HSP expression histopathological and electron microscopical examinations. The results of the study are as follows ; 1. Less cadmium was absorbed through the digestive tracts, but the ratio of contents in tissue were not changed by the simultaneous adminstration of diallyl disufide or retinol acetate. 2. ALT(alanine aminotransferase) , AST(aspartate aminotransferase), glucose, BUN (blood urea nitrogen), creatinine, the key indices of the clinical changes in hepatic and renal function were significantly hanged by the cadmium treatment after 1 week in liver, after 4 weeks in kidney. 3. Histopathological changes in cadmium treated rats were appeared at 8 weeks age treatment in kidneys. Homogenous eosinophilic material was accumulated in cortical and collecting tubular lumens at 16 weeks. Degenerated or necrotized tubular cells were observed in cortex and medulla. Degenerated seminiferous tubules and homogeneous eosinophilic material was seen in interstitial tissue of rat treated with cadmium for 16 weeks. Calcium deposits were seen in degenerated seminiferous tubules and the tubules showed severe calcification of rat treated with cadmium for 16 weeks. Electron microscope changes in kidney were observed in rats treated with CdCl2 20 mg/kg. Proximal convoluted tubule cells showed selling of cytoplasm and narrow lumen. Capillary endothelial cells showed cytoplasmic vacuoles and swelling. Degenerated epithelial cells were accumulated in tubular lumen of kidney. 4. Enhanced synthesis of 70 KDa relateve molecular mass proteins were detected in 2 hours after cadmium, exposure, with maximum activity occurring at 8~48 hours. Induction of HSP 70 was evident at proximal tubules and glomeruli in kidney. Testicular cells produced enough HSP to be detected normally. From the above results, it could be concluded that HSP70 induction by the cadmium treatment was a rapid reaction to indicated the exposure of xenobiotics, and retinol acetate reduced the cadmium induced nephrotoxicity.

• 대한치과보존학회:학술대회논문집
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• 대한치과보존학회 2001년도 춘계학술대회
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• pp.235-237
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• 2001

;Dentistry has benefited from tremendous advances in technology with the introduction of new techniques and materials, and patients are aware that esthetic approaches in dentistry can change one's appearance. Increasingly. tooth-colored restorative materials have been used for restoration of posterior teeth. Tooth-colored restoration for posterior teeth can be divided into three categories: 1) the direct techniques that can be made in a single appointment and are an intraoral procedure utilizing composites: 2) the semidirect techniques that require both an intraoral and an extraoral procedure and are luted chairside utilizing composites: and 3) the indirect techniques that require several appointments and the expertise of a dental technician working with either composites or ceramics. But, resin restoration has inherent drawbacks of microleakage. polymerization shrinkage, thermal cycling problems. and wear in stress-bearing areas. On the other hand, Ceramic restorations have many advantages over resin restorations. Ceramic inlays are reported to have less leakage than resin restoration and to fit better. although marginal fidelity depends on technique and is laboratory dependent. Adhesion of luting resin is more reliable and durable to etched ceramic material than to treated resin composite. In view of color matching, periodontal health. resistance to abrasion, ceramic restoration is superior to resin restorationl. Materials which have been used for the fabrication of ceramic restorations are various. Conventional powder slurry ceramics are also available. Castable ceramics are produced by centrifugal casting of heat-treated glass ceramics. and machinable ceramics are feldspathic porcelains or cast glass ceramics which are milled using a CAD/CAM apparatus to produce inlays (for example, Cered. They may also be copy milled using the Celay apparatus. Pressable ceramics are produced from feldspathic porcelain which is supplied in ingot form and heated and moulded under pressure to produce a restoration. Infiltrated ceramics are another class of material which are available for use as ceramic inlays. An example is $In-Ceram^{\circledR}$(Vident. California, USA) which consists of a porous aluminum oxide or spinell core infiltrated with glass and subsequently veneered with feldspathic porcelain. In the 1980s. the development of compatible refractory materials made fabrication easier. and the development of adhesive resin cements greatly improved clinical success rates. This case report presents esthetic ceramic inlays for posterior teeth.teeth.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제30권3호
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• pp.193-202
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• 2004

Distraction osteogenesis(DO) is defined as a gradual mechanical process of mechanical stretching two vascularized bone surface apart with a critical rate and rhythm such that new bone forms within the expanding gap, reliably bridges the gap, and ultimately remodels to normal structure. DO has become a mainstay in bone tissue engineering and has significantly improved our armamentarium for reconstructive craniomaxillofacial procedures. But the molecular and biological mechanisms that regulate the formation of new bone during distraction osteogenesis are not completely understood. BMPs are potent osteoinductive agents. Our hypothesis was that BMPs, especially BMP-2 and BMP-4, might play an importent role in the signaling pathways that link the mechanical forces created by distraction to biological responses and in promting new bone formation. Using a rabbit's mandible, we investigated the expression of BMP-2, -4 at different time points during distraction osteogenesis. The purpose of this study is to research the pattern of expression of BMP-2, -4 in new bone formation during distraction osteogenesis of the rabbit mandible. The experimental group was applied gradual distraction (0.7mm a day by twice a day, 4.9mm in total, for 7 days) and the control group was carried out osteotomy alone. They were examined clinically, histologically, and by RT-PCR analysis. On 3 days after osteotomy, the high level of expression of BMP-2, -4 was detected. But, the expression of BMP-4 was decreased during latency period. As distraction was started, its expression was increased and maintained till postoperative 28days. In control group, the expression of BMP-4was remarkably decreased till postoperative 14 days. On the other hand, the expression of BMP-2 was no difference between experimental group and control group. The expression of BMP-4 was maintanined at high level during the entire experimental period in both group. These findings suggested that excellent bone formation during distraction osteogenesis is associated with enhanced expression of BMP-4 genes by mechanical tension stress.

• Journal of Periodontal and Implant Science
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• 제24권1호
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• pp.15-25
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• 1994

Keratinized ginigva has clinical singificance in periodontal health because it plays important roles in resistance to mechanical trauma, to penetration of bacteria, and to tensional stress by muscle attachment. In order to investigate the width change of anterior keratinized gingvial during transitional period, the width of kerainized gingiva on anterior teeth was measured annually in elementary school children with deciduous dentition until the successive anterior teeth were completely erupted. The distance from the gingival margin on mid-portion of crown to mucogingival junction was measured by Boley gauge(Hu-Friedy, U.S.A.) and was recorded as the width of keratinized gingiva. The difference of the width of keratinized gingiva according to sex and dentition was analyzed statistically by Student t-test. Following results were obtained : 1. In deciduous dentition, it was shown that the width of keratinized gingiva on maxillary central incisors($3.28{\pm}0.83mm$) was the widest(p<0.01), and that on maxillary lateral incisors, mandibular central and lateral incisors was $2.69{\pm}0.86mm$, $2.51{\pm}0.71mm$, $2.43{\pm}0.68mm$, respectively. 2. In mixed dentition, it was shown that the width of keratinized gingiva on maxillary central incisors ($5.10{\pm}0.86$) was the widest(p<0.01), and that on maxillary lateral incisors, mandibular central and lateral incisors was $4.35{\pm}0.83mm$, $3.51{\pm}0.60mm$, $3.57{\pm}0.66mm$, respectively. 3. The width of anterior keratinized gingiva was significantly increased after the successive anterior teeth were completely erupted(p<0.001). The width of keratinized gingiva on maxillary central and lateral incisors, and mandibular central and lateral incisors was increased by $1.82{\pm}0.83mm$, $1.65{\pm}0.69mm$, $0.99{\pm}0.39mm$, and $1.14{\pm}0.98mm$, respectively. 4. There was no statistical significance in the difference of the width of anterior keratinized gingiva between male and female(p>0.05).