• Restorative Dentistry and Endodontics
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• 제16권1호
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• pp.106-120
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• 1991

The main purpose of this study was to investigate the possibility of obstruction of dentinal tubules through irradiation of the $CO_2$ laser on the dentin surface. For this study, 104 extracted caries - free premolars and molars were grinded their mesial or distal surface to expose dentin completly. And these specimens were divided into three Groups. Group I : those with their smear layer not removed and Group IT : those with their smear layer removed, were irradiated by the $CO_2$ laser(SPACE LASER - $CO_2$ VEGA 25) at five different energy levels ranging 4 - 20J/$cm^2$, and all specimens were observed with scanning eletron microscope (Hitachi S - 450). Group m was divided into 2 sub - groups: one with smear layer, another one without and those were irradiated with $CO_2$ laser of the same condition as Group I & II. All specimens were immersed in, $37^{\circ}C$, 0.5% methylene blue solution for 48 hours after 100 times of thermocycling at $4^{\circ}C$ and $60^{\circ}C$, and were observed with stereo -light microscope (Olympus SZH - ILLD) to evaluate dye penetration. The following results were obtained; 1. The dentinal tubules were obstructed through laser irradiation. 2. The dentinal tubules were still obstructed after treatment of 10% HCl/2sec., then it was proved that acid resistance of detin surface was also increased. 3. The Group of laser irradiation showed less dye penetration than control Group. 4. The smear layer hardly affected obstruction of the dentinal tubules through laser irradiation.

• Journal of Ginseng Research
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• 제35권1호
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• pp.1-11
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• 2011

Korean ginseng is a medicinally important perennial herb from the family Araliaceae. It has been cultivated for its highly valued medicinal properties for over 1,000 years in east Asian countries such as China, Korea, and Japan. Due to its longtime cultivation in shady areas, ginseng is frequently exposed to pathogenic infections. Plants protect themselves from microbial pathogens using an array of defense mechanisms, some of which are constitutively active, while others are activated upon pathogen invasion. These induced defense responses, controlled by defense-related genes, require tradeoffs in terms of plant fitness. We hypothesize that ginseng, as with other plants, possesses regulatory mechanisms that coordinate the activation of attacker-specific defenses in order to minimize fitness costs while attaining optimal resistance. Several classes of defense-related genes are induced by infection, wounds, irradiation, and other abiotic stresses. Both salicylates and jasmonates have been shown to cause such responses, although their specific roles and interactions in signaling and development are not fully understood in ginseng. This review summarizes possible defense-related genes in ginseng based on their expression patterns against biotic and abiotic stresses and describes their functional roles.

• 약학회지
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• 제40권3호
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• pp.351-356
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• 1996

The preparation of Enterococcus faecalis RSI is used as a therapeutics for human intestinal disorders. However, the microbe in this preparation is usually very sensitive to rifampicin and fluoroquinolones. If this preparation is taken with rifampicin or fluoroquinolones, its therapeutic effect can not be expected. E. faecalis RFR11, containing resistance to rifampicin was obtained by MNNG mutation method. Serial passage of E. faecalis RFR11 produced E. feacalis OFR16 on agar with 2-fold minimal inhibitory concentration of ofloxacin produced. E. feacalis OFR16 was resistant to fluoroquinolones up to 8-256 fold higher than that for the original strain. E. faecalis OFR16 also exhibited identical characteristics with the parent strain when they were tested for lactic acid formation and growth inhibition of E. coli MB4-5737 and Shigella sonnei MB4-10411. From in vitro test, it was identified that rifampicin and ofloxacin is not inactivated by certain factors of E. faecalis OFR16. Conclusively. E. faecalis OFR16, rifampicin and fluoroquinolones resistant mutant, is an efficient strain that has insensitivity against rifampicin and fluoroquinolones and original biochemical characteristics of the parent strain.

• 한국결정성장학회지
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• 제27권3호
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• pp.115-121
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• 2017

콘크리트는 열화요인에 의해 철근콘크리트구조물의 철근부식, 균열발생 및 구조내력저하 등 성능저하현상이 사회적 문제점으로 대두되고 있다. 특히 해수, 지하수 또는 오 폐수처리시설 및 하수도 등에 건설되는 콘크리트 구조물은 산 및 황산염에 의한 화학적 침식을 받는 경우 내구성이 크게 저하되어 대책이 필요하다. 따라서 본 연구는 폐유리 미분말과 메타카올린을 사용하여 강모래와 슬래그 잔골재를 비교하여 내황산염성 실험을 진행하였다. 평가 결과 강모래보다 슬래그 잔골재가 내황산염성이 우수하였으며, 폐유리 미분말은 3 % 치환에서 가장 우수한 성능을 발현하였다.

• 대한화학회지
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• 제31권1호
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• pp.102-109
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• 1987

화학증착방법에 의해 dibutyl tin diacetate를 산소와 반응시켜 $SnO_2$박막을 slide glass에 증착시켜 각 조건에 형성된 $SnO_2$박막의 특성을 조사하였다. 본 연구에서 최적증착조건은 기판온도 420$^{\circ}C$, 증착시간 20분으로 나타났으며 증착속도는 증착시간이 증가함에 따라 증가하며 증착시간 25분이후에는 일정해졌으며 판저항의 값도 증착초기에는 감소하나 증착시간 20분이 지나면서 증가하였다. 증착온도 420$^{\circ}C$, 증착시간 20분에 형성된 박막은 두께 4000${\AA}$이며 가시광선 투과율이 90%이며 5800 ohms/${\square}$의 판저항을 가졌다. 그리고 산세척방법에 의해 표면처리한 기판과 반응기체중 수증기의 첨가는 더 좋은 특성의 투명전도성 $SnO_2$박막을 제조하는데 도움이됨을 알았다. 또한 증착막은 작은 구형의 입자들로 이루어져 있다는 것을 주사전자현미경으로 확인하였으며 X-선 회절 실험에 의해 rutile structure(tetragonal)를 갖는다는 것을 알 수 있었다.

• 전기화학회지
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• 제13권2호
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• pp.96-102
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• 2010

본 연구에서는 균일부식이 발생하는 저합금강의 노출면적에 따른 부식속도의 변화를 관찰하고 이에 대한 원인을 규명하고자 하였다. 다양한 표면적을 지닌 동일한 저합금강 시편의 부식속도를 전기 화학적 임피던스 분광법, 직선분극저항 측정법, 동전위 분극 시험법을 이용하여 산출하였다. 또한 전자주사현미경, X선 광전자 분광법 및 X선 전자탐침 미량분석을 이용하여 표면분석을 실시하였다. 전기화학적 시험 결과 모든 시험법에서 시편의 크기가 증가할수록 부식속도가 높게 산출되었으며, 표면분석을 통해 망간과 황으로 구성된 화합물이 존재하는 영역에서 우선적으로 부식이 발생하며, 이 화합물과 철 또는 구리 산화물이 소양극-대음극의 미세 갈바닉 셀을 구성함을 확인하였다. 이러한 효과는 시편 크기에 비례하여 증가하였으며, 국부적인 부식이 우선적으로 발생한 후, 부식생성물이 표면을 덮게 되어 점차 균일부식의 형태로 전환하게 된다.

• Genomics & Informatics
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• 제12권4호
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• pp.195-202
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• 2014

Metabolic syndrome (MetS) is a complex disorder related to insulin resistance, obesity, and inflammation. Genetic and environmental factors also contribute to the development of MetS, and through genome-wide association studies (GWASs), important susceptibility loci have been identified. However, GWASs focus more on individual single-nucleotide polymorphisms (SNPs), explaining only a small portion of genetic heritability. To overcome this limitation, pathway analyses are being applied to GWAS datasets. The aim of this study is to elucidate the biological pathways involved in the pathogenesis of MetS through pathway analysis. Cohort data from the Korea Associated Resource (KARE) was used for analysis, which include 8,842 individuals (age, $52.2{\pm}8.9years$ ; body mass index, $24.6{\pm}3.2kg/m^2$). A total of 312,121 autosomal SNPs were obtained after quality control. Pathway analysis was conducted using Meta-analysis Gene-Set Enrichment of Variant Associations (MAGENTA) to discover the biological pathways associated with MetS. In the discovery phase, SNPs from chromosome 12, including rs11066280, rs2074356, and rs12229654, were associated with MetS (p < $5{\times}10^{-6}$), and rs11066280 satisfied the Bonferroni-corrected cutoff (unadjusted p < $1.38{\times}10^{-7}$, Bonferroni-adjusted p < 0.05). Through pathway analysis, biological pathways, including electron carrier activity, signaling by platelet-derived growth factor (PDGF), the mitogen-activated protein kinase kinase kinase cascade, PDGF binding, peroxisome proliferator-activated receptor (PPAR) signaling, and DNA repair, were associated with MetS. Through pathway analysis of MetS, pathways related with PDGF, mitogen-activated protein kinase, and PPAR signaling, as well as nucleic acid binding, protein secretion, and DNA repair, were identified. Further studies will be needed to clarify the genetic pathogenesis leading to MetS.

• 혜화의학회지
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• 제10권2호
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• pp.91-96
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• 2002

We arrived at the following conclusions after we have studied esophagitis through the literatures of oriental and western medicine. 1. The western medical causes of acute esophagitis are corrosiveness chemical material, esophageal or gastric disease, trauma, blister stomatitis, filamentous fungus infection and uremia of chronic patient etc, and the oriental medical causes are qi and blood stagnation, blood stasis and stagnation, stagnant phlegm by coldness, heating, dyspepsia and food poisoning etc. 2. The western medical causes of chronic esophagitis are malfunction of lower esophageal sphincter, esophageal tom chink and hernia, increase of gastric pressure by overeating, fatness, pregnancy and ascites etc, and the oriental medical causes are asthenic cardiac qi, hepatic qi attacking stomach by seven kinds of depression, cold-damp stagnation and insufficiency of gastric qi by overeating, excessive drinking and sexual indulgence etc. 3. The main symptoms of acute esophagitis are severe chest pain, instantly vomiting, swallowing pain etc, and chronic esophagitis are occasionally light chest pain, heart bum, anorexia, dysphagia, dizziness, general body weakness etc. These symptoms are come under thoracic obstruction, acid regurgitation, vomiting and chest pain of oriental medicine. 4. The western medical diagnoses of acute and chronic esophagitis have used radiation test, esophageal endoscopy, esophageal pressure test and biopsy etc, and the oriental medical diagnoses have used syndrome differentiation by four examination of inspection, listening and smelling examination, inquiring, pulse-taking and palpitation. 5. The western medical treatments of acute esophagitis have regarded preservation stability of esophagus as a principle, and the oriental medical treatments mainly have used expelling pathogen of expelling cold and regulating qi, cooling and removing stasis, promoting blood circulation to remove blood stasis, eliminating phlegm and regulating qi. 6. The western medical treatments of chronic esophagitis have regarded decrease flowing backward of gastric juice as a purpose, and the oriental medical treatments mainly have used strengthening body resistance of replenishing and strengthening cardioqi, dispersing stagnated hepatoqi, expelling cold and dehygrosis, invigorating stomach and nourishing qi.

• 대한기계학회논문집A
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• 제40권9호
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• pp.767-773
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• 2016

산 및 알칼리 용액 속에 침지한 SiC 세라믹의 기계적 특성은 와이블 통계로 해석하였다. 시험편은 1373K에서 열처리를 행하였다. SiC의 부식은 KSL1607 방법에 의한 산 및 알칼리 용액 속에서 수행하였다. 부식된 균열치유재의 굽힘 강도는 부식되지 않은 균열치유재의 굽힘강도보다 산 및 알칼리 용액 속에서 각각 47% 및 70% 감소하였다. SiC 세라믹의 부식은 산 용액 속에서보다 알칼리 용액 속에서 더 빨랐다. 척도 파라미터 및 형상 파라미터는 모재와 부식재에서 평가하였다. 산 및 알칼리 용액에서 부식된 모재의 형상 파라미터는 산용액에서 크게 나타났다. 그러나 열처리재는 산용액에서 크게, 알칼리 용액에서 작게 나타났다. 모재 및 열처리재의 척도 파라미터는 산 및 알칼리 용액에서 모두 작게 나타났다.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• 제41권4호
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• pp.176-180
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• 2015

Objectives: The increased prevalence of antibiotic resistance is an outcome of evolution. Most patients presenting with odontogenic space infections also have associated systemic co-morbidities such as diabetes mellitus resulting in impaired host defense. The present study aims to compare the odontogenic spaces involved, antibiotic susceptibility of microorganisms, length of hospital stay, and the influence of systemic comorbidities on treatment outcome in diabetic patients. Materials and Methods: A 2-year prospective study from January 2012 to January 2014 was conducted on patients with odontogenic maxillofacial space infections. The patients were divided into two groups based on their glycemic levels. The data were compiled and statistically analyzed. Results: A total of 188 patients were included in the study that underwent surgical incision and drainage, removal of infection source, specimen collection for culture-sensitivity, and evaluation of diabetic status. Sixty-one out of 188 patients were found to be diabetic. The submandibular space was the most commonly involved space, and the most prevalent microorganism was Klebsiella pneumoniae in diabetics and group D Streptococcus in the nondiabetic group. Conclusion: The submandibular space was found to be the most commonly involved space, irrespective of glycemic control. Empiric antibiotic therapy with amoxicillin plus clavulanic acid combined with metronidazole with optimal glycemic control and surgical drainage of infection led to resolution of infection in diabetic as well as nondiabetic patients. The average length of hospital stay was found to be relatively longer in diabetic individuals.