초음파를 이용한 연골(軟骨)의 강도 평가

한승무,김문생 韓國非破壞檢査學會 1998 한국비파괴검사학회지 Vol.18 No.5

본 연구에서는 초음파 속도와 광역 감쇠를 이용하여 연골의 강도를 평가하였다. 먼저 60개의 시편을 인체의 연골로부터 얻어서 초음파 속도와 광역 감쇠를 각 시편에 대하여 측정하였다. 시편들은 동일한 두개의 그룹으로 나누어, 0.0004 s-¹와 0.08s-¹의 변형률에서 압축 하중을 작용시킨 후 각 시편에 대한 최대 압축 강도값을 결정하였다. 그 결과, 0.08s-¹에서 측정된 시편들은 0.0004-¹로 측정된 시편들 보다 63%나 더 높은 평균 강도값을 나타내었다. 초음파 속도와 광역 감쇠는 고변형률 및 저변형률 모두에서 골 강도와 밀접한 연관성을 나타내었다. 또한, 골 강도는 모든 변형률에서 초음파 속도와 광역 감쇠의 선형 조합과도 밀접한 관련성을 보였다. 초음파 파라미터의 사용은 여러 가지 골절에 대한 연골의 저항능력을 평가하기 위한 임상 진단법으로 훌륭한 수단이 될 수 있을 것이다. The prediction of bone strength by ultrasound velocity and broadband ultrasound attenuation was examined. Ultrasound velocity and broadband attenuation were measured for sixty specimens of human trabecular bone. Samples were divided into two equal groups and loaded in compression at the strain rates of 0.0004 s-¹and 0.08 s-¹. The ultimate strength was determined for each specimen. Specimens tested at 0.08 s-¹had a mean value of strength 63% higher than the specimens tested at 0.0004 s-¹. Ultrasound velocity and broadband attenuation were significantly associated with compressive strength at both strain rates. Mechanical strength was also correlated strongly with a linear combination of ultrasound velocity and broadband attenuation for both the low and high loading rates. The use of ultrasound parameters may provide good clinical means for assessing the resistance of trabecular bone to both low and high energy trauma.

공공도서관 이용자공간의 공간구성에 관한 연구

한화진,박승환,최무혁 대한건축학회 2004 대한건축학회논문집 Vol.20 No.4

The purpose of this thesis is providing basic data for making establishment of space composition for library users through satisfaction rate of using library and the requirement rate of survey about space composition in terms of library users. Conclusions are as follows. First, there are three types of space compositions considering library users such as a independent space composition(Type A), an open space using lobby(Type B), a multiple space composition(Type C). Prevalent Type B public libraries which are made since 1999 shows the fact that the public libraries space composition have been opened pretty much so far. Second, the result of satisfaction surveying according to space composition condition(Type A B C) shows that Type B and C have much more satisfaction than A has in terms of visual opening, connections with other rooms, furniture arrangements in the inside of the house. Third, on the result of perpendicular analyzing about education, information and culture space composition, the educational function plays an important role with the cultural functions in the main floor. However, at the same time, it is requested that reading space, information space, periodical journal sections should be arranged in it.

방사선 조사에 의한 흰주 난포의 퇴축과 난포세포의 방사선 감수성

김수일,한승로,조근자,허대영,이영호,조문준,김무강,김원식 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

The aim of this study were to investigate radiation-induced atresia and radiation susceptibility in the rat ovary morphologically. Female rats (Sprague Dawley strain) of 4 weeks old were irradiated with dose of 4 Gy and 8 Gy, and sacrificed at hour 6, 12, and 24 after radiation. The H & E stain, the TUNEL method (ApopTag kit) and transmission electron microscopy (TEM) were used. In light microscopic observation, the number of atresia of ovarian follicles were increased significantly at 6h after irradiation (p<0.01). There was no significant difference between 4 Gy and 8 Gy irradiated groups. In TEM observation, granulosa cells in radio-sensitive follicles were characterized by several structural features including condensation of nuclear chromatin granules, nuclear fragmentation and apoptotic body formation. An apoptotic cell is observed to have been phagocytosed by a normal granulosa cell. Granulosa cells in radio-resistant follicles were characterized by several structural features including nuclear indentation, partial condensation of chromatin granules, mitochondrial swelling, dilatation of RER cisterns, accumulation of dense irregular masses, accumulation of lipid droplets, and increased lysosomal bodies. Number of gap junctions between granulosa cells were decreased, and intercellular space were widen than that of control animals. These findings were prominent at 6h after irradiation and were diminished at 12h and 24h after irradiation. With these results, it was concluded that radiation-induced follicular cell apoptosis and ovarian follicular atresia in rat ovary increased considerably at 6h after irradiation. Further studies are needed to reveal the more extensive differences between radiosensitive and radioresistant follicular granulosa cells.

SUPEROXIDE DISMUTASE 가 허혈 손상된 백서 근육 조직에 미치는 영향

민대홍,김승홍,백무현,김승한 大韓成形外科學會 1991 Archives of Plastic Surgery Vol.18 No.4

Superoxide radicals have been shown to play an important role in the cellular injury of reperfused ischemic tissue. We examined the protective effect of superoxide dismutase(SOD), one of the derivatives of superoxide rradical scavengers, on the reperfusion injury of replanted rat limb with 6 - hour is - chemic period. Biochemically, the amounts of superoxide radicals in ischemic hindlimbs treated with SOD have decreased significantly compared to those of control group.(p<0.01) Histologically, SOD treated extremities demonstrated less inflammatory reaction and degenerative change than control group. Our results indicate that the administration of SOD to a amputation part by means of intraarterial perfusion after prolonged period of warm ischemia significantly decreases the tissue damage.

대장암종에서 암관련 유전자들의 Promoter Methylation과 암종 발생 및 진행과의 관게에 대한 연구

정동준,이정은,민영기,조성우,백무준,양승하,김의한,김창진 순천향대학교 교수학습개발센터 2004 Journal of Soonchunhyang Medical Science Vol.10 No.3

The colorectal corcinoma is one of the most common malignant tumor in Korea and its carcinogenic mechanism has not been elucidated exactly yet. So far, the most common carcinogenic mechanism has been known to be multiple genetic changes. But, the CpG island hypermethylation has been revealed to be one of the most important carcinogenic mechanism second to the genetic changes. The epigenetic changes characteristically imprint and transfer to the next generation without changes of nucleotide sequences. When the CpG island of promoter or 5'- exon 1 of a specific gene is methylated by DNA methyltrasferases (DNMTs), the gene expression is inhibited. Carcinogenic mechansisms by promoter methylation has been well known, but the progression of the cancer has not been elucidated yet. The molecular researches on the carcinogenic mechanisms largely depended on the tumor tissue containing various components of cell, due to difficulties in harvesting pure homogeneous tumor cells. Promoter methylatonof the cancer related genes as APc, hMLH2, p16, DAP-K and MGMT in 50 cases of sporadic colorectal carcinoma was studied. The pure normal colorectal epithelial cells, and cancer cells from superficial and deep invasive portion were harvested respectively by laser captured microdissection(LCM), and DNA was extracted from them. The promoter methylation was studied by methylation specific poymerase reaction (MSP) after bisulfite modification of the DNA and the expression of the genes by immunohistochemistry. The results suggests that promoter methylation of the cancer related genes are closely related with the colorectal carcinogenesis and it occurrs from early phase of carcinogenesis, progressing constantly to the late stage. And the promoter methylation of normal epithelial cells increased by age. The p15, known to be the genes related to hematologic malignancy, was closely related to the colorectal carcinoma as well.

인체 간 Microsome에서의 우슬 추출물의 Cytochrome P450 약물 대사효소에 대한 억제작용

김경아,이지숙,박히준,김진우,김창주,심인섭,한승무,임사비나 WHO COLLABORATING CENTRE FOR TRADITIONAL MEDICINE 2003 東西醫學硏究所 論文集 Vol.2003 No.-

Objective : Achyranthes bidentata radix (Usul) has been used as anti-arthritic, antiallergic, antidiuretic and so on Recently extracts of Achyranthes bidentata radix have shown anti-inflammatory and cancer preventive effects in vitro and in vivo. Methods : We therefore evaluated the inhibitory potential of ehtanol extracts of Achyranthes bidentata radix on cytochrome P450(CYP) isoforms-catalyzecd reactions, which relate to causes of cancer and inflammation, including CYP1A2, CYP2C9, CYP2C19, CYP2E1, CYP2D6, CYP2C8, and CYP3A4, using human liver microsomal preparations. Results : The extracts showed weak or negligible inhibitory effects on CYP2C9-catalyzed (S)-warfarin 7-hydroxylation, CYP2C19-catalyzed S-mephenytoin 4-hydroxylation, and CYP2D6-catalyzed dextromethorphan O-demethylation with each IC50 over 1750 g/㎖, respectively. However, it showed relatively significant inhibitory effect on CYP1A2-catalyzed phenacetin O-deethylation and CYP2E1-catalyzed chloizoxazone 6-hydroxylation with IC50s of 970.5 g/㎖ and 821.4 g/㎖, respectively. Conclusions : These results suggest that extracts of Achyranthes bidentata radix have inhibitory effects on CYP-catalyzed reactions, expeciallyCYP1A2 and CYP2E1, in human liver microsomes. These effects appear to relate to anti-inflammatory and cancer prevention following decrease of reactive oxygen species formed by CYP, especially CYP1A2 and CYP2E1, by Achyranthes bidentata radix. However, further evaluation is necessary to demonstrate and to confirm its effects in human.

Response of osteoblast-like cells cultured on zirconia to bone morphogenetic protein-2

Han, Seung-Hee,Kim, Kyoung-Hwa,Han, Jung-Seok,Koo, Ki-Tae,Kim, Tae-Il,Seol, Yang-Jo,Lee, Yong-Moo,Ku, Young,Rhyu, In-Chul Korean Academy of Periodontology 2011 Journal of Periodontal & Implant Science Vol.41 No.5

Purpose: The aim of this study was to compare osteoblast behavior on zirconia and titanium under conditions cultured with bone morphogenetic protein-2. Methods: MC3T3-E1 cells were cultured on sandblasted zirconia and sandblasted/etched titanium discs. At 24 hours after seeding MC3T3-E1, the demineralized bone matrix (DBM) gel alone and the DBM gel with bone morphogenetic protein-2 (BMP-2) were added to the culture medium. The surface topography was examined by confocal laser scanning microscopy. Cellular proliferation was measured at 1, 4, and 7 days after gel loading. Alkaline phosphatase activity was measured at 7 days after gel loading. The mRNA expression of ALPase, bone sialoprotein, type I collagen, runt-related transcription factor 2 (Runx-2), osteocalcin, and osterix were evaluated by real-time polymerase chain reaction at 4 days and 7 days. Results: At 1, 4, and 7 days after loading the DBM gel alone and the DBM gel with BMP-2, cellular proliferation on the zirconia and titanium discs was similar and that of the groups cultured with the DBM gel alone and the DBM gel with BMP-2 was not significantly different, except for titanium with BMP-2 gel. ALPase activity was higher in the cells cultured with BMP-2 than in the other groups, but there was no difference between the zirconia and titanium. In ALPase, bone sialoprotein, osteocalcin, Runx-2 and osterix gene expression, that of cells on zirconia or titanium with BMP-2 gel was much more highly increased than titanium without gel at day 7. The gene expression level of cells cultured on zirconia with BMP-2 was higher than that on titanium with BMP-2 at day 7. Conclusions: The data in this study demonstrate that the osteoblastic cell attachment and proliferation of zirconia were comparable to those of titanium. With the stimulation of BMP-2, zirconia has a more pronounced effect on the proliferation and differentiation of the osteoblastic cells compared with titanium.

Analysis of the Autofrettage Effect in Improving the Fatigue Resistance of Automotive CNG Storage Vessels

Seung-Moo Han,Beom-Cheol Hwang,Ho-Yoon Kim,Chul Kim 한국정밀공학회 2009 International Journal of Precision Engineering and Vol.10 No.1

Type Ⅱ compressed natural gas (CNG) storage vessels for automobiles are becoming widely used. They are not only supplied to automakers in Korea (such as Hyundai Motors), but are being exported overseas in increasing numbers. Autofrettage is a process that produces beneficial residual stresses in a vessel by subjecting it to excessive internal pressure. This strengthens the vessel and improves its fatigue resistance. This paper presents research into the autofrettage process and the residual stresses it produces in type Ⅱ CNG storage vessels. Finite element analysis and a closed-form equation are used. Fatigue resistance is then analyzed via a fatigue evaluation performed according to ASME section Ⅷ.

Evaluation of the Attenuation Rate for Clinical Application of a Flexible Skin Dosimeter in Radiotherapy

Han Moo-Jae,Yang Seung-Woo,Shin Yo-Han,Bae Sang-Il,Moon Young-Min,Jeon Wan,Yu To-Sol,Kang Jin-Kyu,Kim Jin-Young,Heo Seung-Uk,박성광,나정은,Chung Jin Beom 한국물리학회 2020 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.77 No.11

During radiotherapy, some patients owing to the variability in skin sensitivities, may experience adverse skin reactions for doses at which other patients are asymptomatic. Hence, when abnormal symptoms appear on a patient's skin, the etiology should be verified. Accordingly, a surface dosimeter on the skin can help ascertain whether accurate doses are irradiated. Furthermore, surface doses are measured in the field junction gaps during craniospinal irradiation or during large-area radiotherapy to avoid adverse reactions due to cumulative skin doses from multiple beams. However, the point dose measurement errors of surface dosimeters exceed approximately 10% and have low-positional accuracies because the attachment sites are approximated with the help of the naked eye. Moreover, accurate information on field junction gaps cannot be obtained. Therefore, in clinical practice, a flexible array dosimeter is required as it can measure the dose distribution on the body surface by adapting its shape to the body curvatures. In this study, we implemented a flexible array dosimeter and, based on its constituent materials, evaluated the attenuation rate associated with its use. A polyester (PET) film was used as the underlying substrate. HgI2 and PbI2 photoconductors were used for their good performances in films. Furthermore, the measurement accuracy was verified through comparisons with Monte Carlo simulation outcomes. The resulting PET film had an attenuation rate of 2.22% at a 50-μm thickness. At the minimum material thickness of 25 μm, the attenuation rates for HgI2 and PbI2 were 4.69% and 5.72%, respectively. Further research is needed to fabricate HgI2-based digital skin dosimeters with a thickness under 25 μm. Radiation detection and pixel resolution should be evaluated to accurately confirm the field junction gap.

Pattern of Methicillin-resistant Staphylococcus aureus in Dental and Medical Environments

Seung-Ho Han,In-Sook Song,Myeong-Jae Lee,Seung-Il Jeong,Shin-Moo Kim,Kang-Ju Kim KOREAN ACADAMY OF ORAL BIOLOGY 2010 International Journal of Oral Biology Vol.35 No.4

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most prevalent pathogens in hospitals. To investigate cross contamination by this bacterium in both dental and medical settings, the pathogens that cause acute pyogenic infection and one of the major microbes responsible for nosocomial infection were isolated from health care providers, nurses and patients. We used VITEK II to measure drug sensitivity, and we further performed biochemical testing, coagulase serotype testing and pulse-field gel electrophoresis (PFGE) for isolated MRSA colonies. The isolation rate of Staphylococcus aureus from nasal swabs was 75.0% from dental health care providers and 18.8% from the medical health care providers. A total of 10 MRSA strains were isolated from 40 health care providers and 2 patients and the prevalent coagulase serotype from patients and health care providers was VII. The antimicrobial drug resistance and partial PFGE types of the isolated MRSA strains showed a similar pattern. These results suggest that MRSA may be one of the principal causes of nosocomial infection in dental and medical hospitals.