대덕지역 환경방사선에 대한 감마선 분광분석연구

전재식,오희필,오헌진,윤주용 충남대학교 자연과학연구소 1983 忠南科學硏究誌 Vol.10 No.1

For an assessment of local environmental radiation characteristics, a series of in-situ spectrometry was carried out at four different points in open field of Daedeok area and inside a laboratory of CNU usiing 3″×3″cylindrical NaI(T1) scintillation detector and 400 channel pulse height analyzer. The exposure rate was evaluated from the measured gamma-ray spectrum by means of direct spectrum-exposure rate conversion operation. Thus evaluated exposure rate was compared with that observed by a pressurized ionization chamber at the same pont and time, and the comparison showed good agreement within statistical uncertainty. The exposure rate, corrected for the contribution of cosmic ray photon below 3 Mev, self-contamination of ^(40)K, and directional response of the detector, was found to range from 9.77 to 10.72 μR/hr in open field, while it was 12.46 μR/hr inside the laboratory. Analysis of the gamma-ray spectra revealed that the majority of the environmental radiation in this area consists of the gamma-rays from ^(238)U and ^(232)Th decay series plus those from ^(40)K.

감마선 분광분석법에 의한 환경방사선 연구

윤주용,전재식,오희필 충남대학교 자연과학연구소 1984 忠南科學硏究誌 Vol.11 No.1

For the purpose of practical assessment of resional environmental radiation characteristics, a series of in-situ spectromentry was carried out using a 3″ø×3″cylindrical NaI(T1) scintillation detector in association with a MCA at eight different points in open field of Daejeon area. In determining the exposure rate from the spectra obtained, the methods developed by Beck et al. was used. The exposure rate evaluated in this way was compared with those observed by the Moriuchi's spectrum-exposure rate conversion operator, and Reuter/Stokes environmental radiation monitor. The three results were in good agreement within statistical uncertainty. Although the exposure rate in this area varied with place, the spectra measured are quite similar in pattern. It was shown that the major part of the terrestrial radiation in the area consists of the gamma-rays emitted from the daughter products of ^238U and ^232Th series and then from ^40K.

생활치 미백제가 우치 법랑질의 투명도에 미치는 영향

김동준,김영주,김학근,박은종,서은주,황윤찬,오원만,황인남 大韓齒科保存學會 2005 Restorative Dentistry & Endodontics Vol.30 No.3

본 연구에서는 현재 임상에서 home bleaching을 위해 사용되고 있는 표백 재료들이 치아 법랑질의 투명도에 어떠한 변화를 일으키는지 고찰해 보고자 시행하였다. 실험 대상으로는 하루 전 발거한 우치 (bovine tooth)를 사용하였다. 치아의 순면에 수직되게 다이아몬드 드릴을 이용해 수주 하에서 직경 6 mm의 원통형 치아 시편을 만들어 순면이 노출된 상태로 투명한 아크릭 레진에 포매한 후, low speed diamond saw (Isomat, Buehler Co., USA)를 사용하여 1.2 mm 두께로 절단하였다. 절단된 시편은 순면을 먼저 편평하게 연마하고,절단된 면을 연마하여 두께 1 mm의 시편을 완성하였다. 완성된 시편(우치 25개)을 무작위로 추출하여 3개의 그룹으로 나누고 나머지는 대조군으로 하였다. Opalescence (10% carbamide peroxide, Ultradent, Milford, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) 및 Opalescence F(15% carbamide peroxide with fluoride, Ultradent)를 시편의 순면에 1주일 동안 적용 (표백제는 24시간마다 교체)하였고, 설측면은 증류수를 적신 거즈에 접촉된 상태로 보관하였다 표백제를 적용하기 전과 적용 3, 5, 7일째에 시편의 삼자극치 X, Y, Z 값을 색채색차계 (Color & Color Differencemeter, Model TC-6FX, Tokyo Denshoku Co., Japan)로 백색 배경판과 흑색 배경판 상에서 측정하였다 백색 배경판과 흑색 배경판 상에서 측정된 Y값의 평균값을 이용해 contrast ratio를 계산하였다 얻어진 값을 One Way Repeated Measured ANOVA를 이용하여 통계 처리한 결과 10% Opalescence처치군, 15% Opalescence-F처치군 및 대조군에서는 통계적으로 유의할만한 증감을 보이지 않았고, Rembrandt처치군에서는 Contrast ratio가 증가하였다 (p < 0.01) . This study was done to evaluate whether vital bleaching agents could influence on the translucency of the bovine enamel. The anterior bovine teeth that were extracted one day before and without any gross discoloration were obtained and then were preserved in physiologic saline. 6 mm cylindrical tooth specimens were fabricated with diamond puncher perpendicularly on labial surface of bovine tooth. After embedded in transparent acrylic resin with labial surface being exposed, they were cut to a thickness of 1.2 mm with low speed diamond saw (Isomat, Buehler Co., Lake Bluff, IL, USA). They were smoothly ground to 1 mm thickness of enamel with sandpaper. 24 specimens were randomly divided into 3 groups and control group respectively. Opalescence (10% carbamide peroxide, Ultradent, South Jordan, USA), Rembrandt (10% carbamide peroxide, DenMat, USA) and Opalescence F (15% carbamide peroxide with fluoride, Ultradent, USA) were applied on labial sides of the bovine enamel for 7 days (bleaching agents were reapplied every 24 hours) and the opposite surface was contacted to cotton that soaked in distilled water. The control group was soaked in distilled water. Three stimulus value X, Y and Z were evaluated with colorimeter (Color ' Color Differencerneter, Model TC-6FX, Tokyo Denshoku Co., Japan) on the labial surface of all specimen three times on white and black background plate before the bleaching agents were applied and on 3rd, 5th and 7th day after applied. The degree of translucency was normally assessed by measuring the inverse property, opacity (contrast ratio). 10% Opalescence, 15% Opalescence-F, and control group showed no significant variation in the translucency of bovine enamel, However Rembrandt decreased the translucency of it (p < 0.01).

降水物 tritium濃度의 年中變化

蔡貞淑,尹柱庸,田載植 충남대학교 자연과학연구소 1983 忠南科學硏究誌 Vol.10 No.1

A series of measurements of tritium concentration in precipitation has been carried out at the College of Sciences, Chungnam National University for a period of one year from March 1982 to February 1983. Samples were taken from every precipitation and processed through electrolytic enrichment for liquid scintillation counting of tritium activity. Results are summarized in a table and figure which shows a rough periodicity in the annual variation of tritium concentration with a maximum monthly mean of 1318±197 TR in April 1982 and a minimum of 220±37 TR in July of the same year.

장기간의 장거리 달리기가 골대사 마커에 미치는 영향

장성동,이은희,홍명엽,문성진,김주혁,이윤관,김영준 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

This study is purposed to analyse the effects of long-term & one-time 10km running exercise from bone metabolic marker change on bone metabolism. 7 male members(18.6±1.08) from a marathon club were subjected to the study. They were allowed to do long-term 10 km running training once a week for 6 months. And bone metabolism mark was determined according to the respective times : before/after 6 months training, before/after 10 km race, one day after the race, 3 days after the race. The examination items of bone metabolism mark were serum calcium, phosphorus, paratyroid hormone, osteocalcin, calcitonin, alkaline phosphatase in blood and calcium, phosphorus, deoxypyridinolin in urine. The results of study were as follows; 1) There was no change in deoxypyridinolin and alkaline phosphatase but there was significant change in calcitonin, paratyroid hormone and osteocalcin(p<.01). 2) There was no change of Calcium in serum and urine but there was significant change of phosphorus in blood(p<.01). To make a conclusion, it is determined that long-term 10 km running at low intensity and low frequency tends to restrict bone metabolism circulation, but exercise at a little high level activates bone metabolism into building up bones and absorbing bones and finally shows up high bone metabolism circulation, which is inferred to have an effective influence on bone health. It is considered there is a possibility that different exercise intensity, even same kind of exercise, influences on bone metabolism sdifferently.

Cellular organization of three germ layer cells on different types of noncovalent functionalized graphene substrates

Yun, Yong Ju,Park, Soon-Jung,Seo, Joseph,Song, Yun-Ho,Ha, Dong Han,Chung, Hyung-Min,Jun, Yongseok,Moon, Sung-Hwan Elsevier 2019 Materials Science and Engineering C Vol. No.

<P><B>Abstract</B></P> <P>Graphene and its derivatives have seen a rapid rise in interest as promising biomaterials especially in the field of tissue engineering, regenerative medicine, and cell biology of late. Despite its proven potential in numerous biological applications, information regarding the relationship between the different forms of graphene and cell lineages is still lacking partly due to its topical emergence in cellular studies. Herein, we explore the biocompatibility of four types of graphene substrates (chemical vapor deposition grown graphene, mechanically exfoliated graphene, chemically exfoliated graphene oxide, and reduced graphene oxide) with three types of somatic cells (keratinocytes, hepatocytes, endothelial cells) derived from the three germ layers in relation to cell adhesion, proliferation, morphology, and gene expression. The results revealed exceptional cell adhesion for all tested groups but enhanced proliferation and cytoskeletal interconnectivity in graphene oxide and reduced graphene oxide substrates. We were unable to detect any adverse effects in gene expression and survivability during a week of culture. We further show topographic changes to graphene substrates under fetal bovine serum adsorption to better illustrate the actual microenvironment of inhabitant cells. This study highlights the extraordinary synergy between graphene and somatic cells, suggesting the discretionary use of extracellular matrix components for <I>in vitro</I> cultivation.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The type of graphene can influence the cellular organization of somatic cells and its cytoskeletal structure. </LI> <LI> Somatic cells exhibit enhanced proliferation and cytoskeletal interconnectivity when cultivated on GO and RGO. </LI> <LI> Topographic shifts following FBS adsorption is more pronounced in GO and RGO. </LI> <LI> All four graphene derivatives showed no adverse effect in gene expression and survivability. </LI> <LI> The molecular properties of functionalized graphene can be better manipulated to enhance cell-substrate interactions. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A 3D scaffold for ultra-sensitive reduced graphene oxide gas sensors

Yun, Yong Ju,Hong, Won G.,Choi, Nak-Jin,Park, Hyung Ju,Moon, Seung Eon,Kim, Byung Hoon,Song, Ki-Bong,Jun, Yongseok,Lee, Hyung-Kun The Royal Society of Chemistry 2014 Nanoscale Vol.6 No.12

<P>An ultra-sensitive gas sensor based on a reduced graphene oxide nanofiber mat was successfully fabricated using a combination of an electrospinning method and graphene oxide wrapping through an electrostatic self-assembly, followed by a low-temperature chemical reduction. The sensor showed excellent sensitivity to NO2gas.</P>

Study on Effective Management Plan by Characteristics of Landslide Occurrence Area in Korea National Parks

Ju Ung Yun,Won Ok Jeong,Jun Hyo Park,Youn Tae Lee,Kye Won Jun,Sang Hee Lee 위기관리 이론과 실천 2021 Crisisonomy Vol.17 No.7

본 연구는 최근까지 국립공원 지역에서 발생한 474개소에 대하여 자료를 수집하고 산사태 발생인자 별 물리적 특성분석을 수행하여 그 결과를 바탕으로 산사태 발생지의 복원 및 모니터링 기준을 제시 하였다. 국립공원 지역의 산사태는 고도, 경사, 발생위치, 사면방위, 임상, 모암, 사면형, 사면단면형, 발생폭, 발생길이, 발생면적의 조건에서 산사태 발생빈도가 높은 것으로 분석되었다. 분석 결과를 기반으로 인공복원 1개소, 일부 인공복원(지반안정) 20개소, 일부 인공복원(식생도입) 1개소, 자연복 원 352개소, 복원완료 100개소로 분류하였으며, 모니터링 대상지 분류를 통하여 단기모니터링 대상 지 56개소, 중기모니터링 대상지 109개소, 장기모니터링 대상지 209개소, 복원완료 100개소로 분류 하였다. 산사태 발생지에 대한 지속적인 자료수집과 분석을 통하여 복원방법, 모니터링 대상지의 선정과 관리 기술을 확립하고 축적하여 경관 및 생태적으로도 보전가치가 매우 높은 국립공원에서 아름다운 자연환경을 보전, 관리하고, 인명과 재산피해를 최소화하는 데 효과적일 것으로 판단된다. This study collected data on 474 sites that occurred in national parks until recently and analyzed the physical characteristics of each landslide occurrence factor, we suggested the criteria for restoration and monitoring of landslide occurrence areas. Landslides were analyzed to occur frequently in national parks under condition of altitude, slope, position, aspect, forest type, parent rock, cross slope, vertical slope, width, length and area. Based on the analysis results, it was classified into 1 place of artificial restoration, 20 places of partly artificial restoration 1 place of partly artificial restoration, 352 places of natural restoration and 100 places of restoration completed by the criteria of restoration plan. Also, according to the criteria of monitoring plan, it was classified into 56 sites for short-term monitoring, 109 sites for medium-term monitoring, 209 sites for long-term monitoring and 100 sites for restoration completed. If we establish and accumulate restoration methods, it will be effective in preserving and managing the beautiful natural environment of national parks which has a very high conservation value both in landscape and ecology, and in minimizing casualties and property damage.

Protective effect of epigallocatechin gallate against colon carcinogenesis induced by azoxymethane and hemin in mice

Ju Hyung Seok(Ju Hyung Seok),Ye Seo Jeong(Ye Seo Jeong),Hyeon Ji Kim(Hyeon Ji Kim),Sung-Jun Kim(Sung-Jun Kim),Young Won Yun(Young Won Yun),Sang Yoon Nam(Sang Yoon Nam),Beom Jun Lee(Beom Jun Lee) 한국예방수의학회 2017 한국예방수의학회 학술대회자료집 Vol.2017 No.-

Grape seed proanthocyanidin extract ameliorates monosodium iodoacetate-induced osteoarthritis

Woo, Yun-Ju,Joo, Young-Bin,Jung, Young-Ok,Ju, Ji-Hyeon,Cho, Mi-La,Oh, Hye-Jwa,Jhun, Joo-Youn,Park, Mi-Kyung,Park, Jin-Sil,Kang, Chang-Min,Sung, Mi-Sook,Park, Sung-Hwan,Kim, Ho-Youn,Min, Jun-Ki Korean Society for Biochemistry and Molecular Bion 2011 Experimental and molecular medicine Vol.43 No.10

Osteoarthritis (OA) is an age-related joint disease that is characterized by degeneration of articular cartilage and chronic pain. Oxidative stress is considered one of the pathophysiological factors in the progression of OA. We investigated the effects of grape seed proanthocyanidin extract (GSPE), which is an antioxidant, on monosodium iodoacetate (MIA)-induced arthritis of the knee joint of rat, which is an animal model of human OA. GSPE (100 mg/kg or 300 mg/kg) or saline was given orally three times per week for 4 weeks after the MIA injection. Pain was measured using the paw withdrawal latency (PWL), the paw withdrawal threshold (PWT) and the hind limb weight bearing ability. Joint damage was assessed using histological and microscopic analysis and microcomputerized tomography. Matrix metalloproteinase-13 (MMP13) and nitrotyrosine were detected using immunohistochemistry. Administration of GSPE to the MIA-treated rats significantly increased the PWL and PWT and this resulted in recovery of hind paw weight distribution ($P$ < 0.05). GSPE reduced the loss of chondrocytes and proteoglycan, the production of MMP13, nitrotyrosine and IL-$1{\beta}$ and the formation of osteophytes, and it reduced the number of subchondral bone fractures in the MIA-treated rats. These results indicate that GSPE is antinociceptive and it is protective against joint damage in the MIA-treated rat model of OA. GSPE could open up novel avenues for the treatment of OA.