• 제목/요약/키워드: $^{234}Th$

검색결과 128건 처리시간 0.027초

기계학습법을 이용한 동해 울릉분지의 봄과 여름 순군집생산 추정 (Estimation of the Spring and Summer Net Community Production in the Ulleung Basin using Machine Learning Methods)

  • 함도식;이인희;추민기
    • 한국해양학회지:바다
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    • 제29권1호
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    • pp.1-13
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    • 2024
  • 동해 남서부해역은 대마난류나 연안 용승에 의한 영양염 공급 등으로 동해 북부나 동부에 비해 일차생산력이 높은 것으로 알려져 있지만, 이 해역의 생물 펌프에 관한 연구는 제한적이다. 본 연구에서는 O2/Ar 측정으로 산출한 고해상도 순군집생산 현장 관측 결과와 기계학습 모형을 결합하여 시공간 해상도가 8일 간격, 4 km인 봄과 여름 순군집생산 시계열 자료를 추정하였다. 기계 모형의 예측과 실측의 평균 제곱근 오차는 6 mmol O2 m-2 d-1로 관측값 평균의 15%에 해당했다. 울릉분지 중앙부의 순군집생산은 3월에 49 mmol O2 m-2 d-1로 가장 높았고, 6월과 7월에 18 mmol O2 m-2 d-1로 가장 낮았다. 이 같은 계절 변화는 3He 기체교환율로 추정한 질산염 공급률이나 234Th 비평형법으로 추정한 입자유기탄소 방출률과 유사하였다. 봄과 여름의 순군집생산 추정으로 한정된 이 연구방법을 가을과 겨울로 확대하기 위해서는 아표층수의 표층 혼입에 따른 O2/Ar 순군집생산의 오차를 보정하는 연구가 필요하다.

중안면골 골절에 대한 임상통계학적 연구 (A CLINICOSTATISTICAL STUDY ON MIDFACIAL BONE FRACTURE)

  • 유선열;조규승
    • Maxillofacial Plastic and Reconstructive Surgery
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    • 제19권4호
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    • pp.367-376
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    • 1997
  • 저자등은 1992년 1월 1일부터 1996년 12월 31일까지 최근 5년간 전남대학교병원 구강악안면외과에 입원하여 치료받은 환자중 추적이 가능한 중안면골 골절 환자 234례에 대해 임상통계학적 비교 분석하여 다음과 같은 결과를 얻었다. 남녀비는 5.3 : 1로 남자에서 호발하였고, 연령별로는 20대, 30대, 10대순으로, 월별로는 8월, 5월, 9월과 10월 순으로 발생하였다. 발생원인은 자동차사고, 추락사고, 오토바이 사고의 순이었고, 골절부위로는 관골-상악골 복합골절이 86례로 가장 많았다. 연관 손상으로는 안면열상이 가장 많았으며 신경외과적 손상, 하악골 골절순이었다. 수상후 수술시 까지 경과시간은 1주일이내가 55%였다. 사용된 금속판수는 관골 또는 상악골 단독골절시에는 2개, 관골-상악골 복합 골절시에는 3개, Le Fort I, Le Fort I, II ; II, III ; I, III ; Le Fort I,II,III 골절시에는 각각 4개, 5.5개, 7개였다. 술후 합병증으로는 감염 7례, 안면비대칭 6례, 안구함몰증 5례, 부정교합 2례로 모두 20례(8%)가 발생하였다. 이상의 결과는 중안면골 골절시에 골절 부위와 환자의 전신상태 및 연관 손상에 대한 신속한 진단과 치료가 필요하고 타과와의 협동 치료가 이루어져야 함을 시사하였다.

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첫째 아이의 스트레스와 측두하악장애에 관한 연구 - 고등학생을 중심으로 - (A study on TMD and stress of first children)

  • 김명은
    • 한국치위생학회지
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    • 제10권4호
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    • pp.683-693
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    • 2010
  • Objectives : The purpose of this study was to examine the relation between stress and temporomandibular disorder(TMD) of first the child. Methods : 500(the first child -250, non first child -250) high school students living in Jecheon city, form November 4th to 5th 2009, were the subjects of this questionnaire. The questionnaire was made up of three contests: sociodemographic characteristic, symptom & dysfunction of TMD and stress of high school students. The data were analyzed by chi-square test, two sample t-test and Pearson correlation. Results : Only 443(the first child -209, non first child - 234) students were evaluated due to inadequate responses. The obtain results was as follow. 1. Subjective symptom of TMD reported by 443 students were joint sound(63.5%), pain on chewing(55.1%), pain on opening the mouth(55.1%). 2. Analysis of subjective symptom of TMD showed the first child group was statistical significantly higher on joint sounds and TMJ pain than non first child group(<0.05). 3. Analysis of bad habit and dysfunction showed the first child group was statistical significantly higher on clenching of the teeth, difficulties of bite, headache than non first child group(<0.05). 4. Analysis of stress showed the first child group was statistical significantly higher on stress with parents than non first child. especially on marks and disagreement(<0.05). 5. Stress were partly related to subject symptom of TMD(<0.05, <0.01). 6. Analysis of relation stress and bad habit & dysfunction showed stress were partly related to bad habit & dysfunction(<0.05, <0.01). 7. bad habit were partly related to TMD(<0.05, <0.01). Conclusions : The first child stress and symptom of TMD were higher than non-first child, also stress and symptom of TMD was positively associated. therefore management of the first child' stress is necessary and related study is necessary in the future.

서울시 지하철역사의 라돈농도분포 조사 (Distribution of Radon Concentration at Subway Station in Seoul)

  • 이철민;김윤신;김종철;전형진
    • 한국환경보건학회지
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    • 제30권5호
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    • pp.469-480
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    • 2004
  • The radon concentrations were measured to survey distribution of radon concentrations in Seoul subway stations. The radon concentrations in air and water were measured at seventeen subway stations(Mapo, Chungjongno, Sodaemun, Kwanghwamun, Chongno3ga, Ulchiro4ga, Tangdaemun, Sangildong on Line 5;Nowon, Chunggye, Hagye, Kongnung, Taenung, Mokkol, Chunghwa, Sangbong, Myomok on Line 7) using the $RAdtrak^{TM}$ radon gas detector, Pylon AB-5 continuous passive radon detector and liquid scintillation counting method from January to May 1999. The major results obtained from this study were as follows: The long-term mean concentrations of radon were $61.8\;Bq/m^3$ in office, $78.9\;Bq/m^3$ in platform, $38.2\;Bq/m^3$ in concourse and $20.1\;Bq/m^3$ in outdoor, respectively. These levels were less than the action level ($148\;Bq/m^3$) of the U.S. EPA. The highest level of short-term mean concentrations was $116.55\;Bq/m^3$ at Chongno3ga station on the 5th line subway stations, while the lowest mean concentration was $19.55\;Bq/m^3$ at Mokkol station on the 7th line subway stations. The highest concentration of radon in the road water and storing underground water in the subway stations was $234.7\;KBq/m^3\;and\;155.5\;KBq/m^3$ in Sodaemun subway station, respectively. The results suggest that radon concentration in subway stations seems to be affected by ventilation and radon concentratin in underground water in the subway stations.

조선시대 문헌에 기록된 제주도 전통식물의 통시적 연구-세종실록지리지, 신증동국여지승람, 탐라지, 남환박물, 제주계록을 중심으로- (Study of Traditional Plants of Jeju Island (Five literatures in Joseon Dynasty period))

  • 이창숙;여성희;정소연
    • 한국자원식물학회지
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    • 제29권2호
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    • pp.225-234
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    • 2016
  • 조선시대 15세기부터 19세기에 편찬된 5개의 문헌, 세종실록지리지, 신증동국여지승람, 탐라지, 남환박물, 제주계록에 실린 문헌을 해제 분석하고, 제주도에 서식하는 자원이 되는 관속식물을 조사 분석해 고전명과 현대명을 분석 정리하여 관련된 전통지식을 파악하였다. 그 결과 65과 112속 118종 13변종으로 총131분류군이 확인되어 현 제주도 자생식물의 7.3%에 해당하는 식물들이 조사되었다. 이 중 21.4%가 남방계식물이었다. 5개의 문헌 중 식물종류가 가장 많이 기록된 문헌은 남환박물로, 89분류군이 기록되었다. 고전식물명을 현대식물명의 일치여부를 분석 조사하였고, 아울러 그 중 문제가 되었던 식물들에 관해 논의하였다.

초등학교 교사의 건강지각, 건강상태와 건강증진행위 (Health Perception, Health Status and Health Promotion Behaviors of Elementary School Teacher)

  • 정수희;김동희
    • 한국학교보건학회지
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    • 제30권3호
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    • pp.355-364
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    • 2017
  • Purpose: The purpose of this study was to identify health promotion behaviors of elementary school teachers and investigate the factors influencing the health promotion behaviors. Methods: Data were collected from 234 elementary school teachers in the B Metropolitan City Office of Education from 5th to 30th October, 2016. The collected data were analyzed by descriptive statistics, t-test, ANOVA, $Scheff{\acute{e}}$ test, Mann-Whitney test, Kruskal-Wallis test, Spearman correlation coefficient and multiple regression analysis, using SPSS/WIN 23.0. Results: The elementary school teachers' health perception scored 2.94 out of 4, health status 1.59 out of 3, and health promotion behaviors 2.66 out of 4. The level of mental health status (1.67) was higher than that of physical health status (1.54) and the most practiced health promotion behavior was spiritual growth (3.15) and the least was health responsibility (2.00). Significant negative correlations were found between health perception and health status (r=-.59, p<.001) and between health status and health promotion behaviors (r=-.41, p<.001). A significant positive correlation was found between health perception and health promotion behaviors (r=.32, p<.001). The significant factors influencing health promotion behaviors were job stress and health status. These factors explained 19.6% of the health promotion behaviors. Conclusion: It is necessary to establish measures to increase the health perception and health promotion behaviors of elementary school teachers and improve their health status. In addition, since job stress and health status are factors influencing health promotion behaviors, it is necessary to actively manage job stress and health status in order to increase health promotion behaviors.

The effect of overweight on the luteinizing hormone level after gonadorelin stimulation test in girls with idiopathic central precocious puberty

  • Lee, Hyun Young;Lee, Yoon-Ji;Ahn, Moon-Bae;Cho, Won-Kyoung;Suh, Byung-Kyu
    • Annals of Pediatric Endocrinology and Metabolism
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    • 제23권4호
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    • pp.215-219
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    • 2018
  • Purpose: We investigated the effect of overweight on luteinizing hormone (LH) levels after a gonadorelin stimulation test in Korean girls with idiopathic central precocious puberty (CPP). Methods: Medical records of 234 girls diagnosed with idiopathic CPP were reviewed retrospectively. CPP was diagnosed when the peak LH levels after gonadorelin stimulation was >5.0 U/L. The enrolled girls had a peak LH level >5.0 U/L after a gonadorelin stimulation test. Selected girls were classified as normoweight (body mass index [BMI] below the 85th percentile with respect to age) and overweight (BMI greater than the 85th percentile with respect to age). Results: The peak LH ($8.95{\pm}2.85U/L$ vs. $11.97{\pm}8.42U/L$, P<0.01) and peak folliclestimulating hormone ($9.60{\pm}2.91U/L$ vs. $11.17{\pm}7.77U/L$, P=0.04) after gonadorelin stimulation were lower in overweight girls with idiopathic CPP than in normoweight girls with idiopathic CPP. Being overweight was negatively associated with peak LH levels after gonadorelin stimulation test (odds ratio, 0.89; 95 % confidence interval, 0.81-0.98, P=0.02). Conclusion: In girls with idiopathic CPP, being overweight led to a lower LH peak after gonadorelin stimulation. Further research is needed to better understand the role of overweight on gonadotropin secretion in precocious puberty.

Neuroprotective Effect of β-Lapachone in MPTP-Induced Parkinson's Disease Mouse Model: Involvement of Astroglial p-AMPK/Nrf2/HO-1 Signaling Pathways

  • Park, Jin-Sun;Leem, Yea-Hyun;Park, Jung-Eun;Kim, Do-Yeon;Kim, Hee-Sun
    • Biomolecules & Therapeutics
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    • 제27권2호
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    • pp.178-184
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    • 2019
  • Parkinson's disease is a neurodegenerative disease characterized by the progressive loss of dopaminergic neurons within the substantia nigra pars compacta. In the present study, we investigated whether ${\beta}-Lapachone$ (${\beta}-LAP$), a natural naphthoquinone compound isolated from the lapacho tree (Tabebuia avellanedae), elicits neuroprotective effects in a 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced Parkinson's disease mouse model. ${\beta}-LAP$ reduced the tyrosine hydroxylase (TH)-immunoreactive fiber loss induced by MPTP in the dorsolateral striatum, and alleviated motor dysfunction as determined by the rotarod test. In addition, ${\beta}-LAP$ protected against MPTP-induced loss of TH positive neurons, and upregulated B-cell lymphoma 2 protein (Bcl-2) expression in the substantia nigra. Based on previous reports on the neuroprotective role of nuclear factor-E2-related factor-2 (Nrf2) in neurodegenerative diseases, we investigated whether ${\beta}-LAP$ induces upregulation of the Nrf2-hemeoxygenae-1 (HO-1) signaling pathway molecules in MPTP-injected mouse brains. Western blot and immunohistochemical analyses indicated that ${\beta}-LAP$ increased HO-1 expression in glial fibrillary acidic protein-positive astrocytes. Moreover, ${\beta}-LAP$ increased the nuclear translocation and DNA binding activity of Nrf2, and the phosphorylation of upstream adenosine monophosphate-activated protein kinase (AMPK). ${\beta}-LAP$ also increased the localization of p-AMPK and Nrf2 in astrocytes. Collectively, our data suggest that ${\beta}-LAP$ exerts neuroprotective effect in MPTP-injected mice by upregulating the p-AMPK/Nrf2/HO-1 signaling pathways in astrocytes.

방사선조사가 저칼슘식이 백서 치주조직에 미치는 영향에 관한 연구 (THE EFFECTS OF IRRADIATION ON THE PERIODONTAL TISSUES OF RATS WITH THE LOW CALCIUM DIET)

  • 최문철;이상래
    • 치과방사선
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    • 제22권2호
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    • pp.223-234
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    • 1992
  • The purpose of this study was to investigate the changes of periodontal tissues in the irradiated mandibular bone in rats which were fed normal diet and low calcium diet In order to carry out this experiment, 64 seven-week old Sprague-Dawley strain rats weighing about 150gms were selected and equally divided into one experimental group of 32 rats and one control group with the remainder. The experimental group and the control group were then subdivided into two groups when the rats reached the age of 10 weeks, 16 rats were allotted for each subdivided group was composed of 16 rats and exposed to irradiation. The two groups were irradiated a single dose of 20Gy on the only jaw area and irradiated with a cobalt-60 teletherapy unit The rats in the control and experimental groups were serially dissected by fours on the 3rd, the 7th, the 14th, and the 21st day after irradiation. After each dissection, both sides of the dead rat mandibular bodies were removed and fixed with 10% neutral formalin. The specimens sectioned and observed in histopathological. histochemical. and immunocellular chemical methods. The obtained results were as follows: 1. In the mandibles of rats with low calcium diet the increased number of fibroblasts of periodontal ligaments. many small capillaries and irregular arrangement of loose collagen fibers were detected and the partial resorption of dentin and cementum could be found by the microscopic studies. 2. In the group of irradiated rats, degenerated periodontal tissues led to the condition of irregular arrangement of collagen fibers and the decreased number of fibroblasts. But this condition was somewhat restored after 21 days of experiment. 3. Periodontal tissues of the irradiated rat group with low calcium diet were destroyed earlier than those of the irradiated rat group with normal diet. Soon this condition was restored and then high cellularity and dense collagen fibers were observed. 4. Many periodontal cells bearing tumor necrosis factor could be clearly observed in the nonirradiated group of rats with normal diet, whereas could not be observed on the 7th day and reappeared on 14th day in the irradiated group of rats with normal diet. A few of them could be observed in the group of rats with low calcium diet, but they could be clearly observed in the both groups after 21 days of experiment.

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남극 아문젠해에서 234Th/238U 비평형법을 사용한 유광대에서 심층으로의 입자상 유기탄소 침강플럭스 추정; 예비결과 (Estimation of POC Export Fluxes Using 234Th/238U Disequilibria in the Amundsen Sea, Antarctica; Preliminary Result)

  • 김미선;최만식;이상헌;이상훈;이태식;함도식
    • 한국해양학회지:바다
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    • 제19권2호
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    • pp.109-124
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    • 2014
  • 남극 아문젠해의 탄소순환을 이해하기 위해서 표층에서 심층으로의 입자상 유기탄소 침강플럭스를 ${\psi}$/${\psi}$ 비평형법을 이용하여 추정하였다. 2012년 2월과 3월에 걸쳐 남극 아문젠해의 총 14개 정점에서 깊이별로 해수시료를 채취하였고, 총 ${\psi}$, 용존 ${\psi}$ 및 입자상 유기탄소를 분석하였다. 수심에 따라 총 ${\psi}$의 활동도 농도는 ${\psi}$에 비하여 결핍과 과잉을 나타내었다. 유광대에서 총 ${\psi}$의 결핍 정도는 엽록소 및 형광도와 거울상을 나타내고, 질산염 제거와 수반되어 나타나므로 생물 활동의 영향으로 파악되었다. 심층에서 일어나는 총 ${\psi}$ 결핍은 Fe/Mn 산화물에 의해 이루어지는 것으로 해석되었다. 유광대 바로 아래의 수층에서 나타나는 총 ${\psi}$ 과잉은 재광물화 작용보다는 이 깊이에 집적된 입자상 ${\psi}$에 기인하였다. 정상상태 모델로 추정한 ${\psi}$의 침강플럭스는 평균 $867{\pm}246dpmm^{-2}day^{-1}$이었으며, 유광대에서 질소와 인의 결핍 총량과 밀접한 관련성을 보였다. 입자상 유기탄소와 ${\psi}$의 비율($7.08{\pm}4.27{\mu}molCdpm^{-1}$)을 이용하여 추정한 입자상 유기탄소의 침강플럭스는 평균 $5.9{\pm}3.9mmolCm^{-2}day^{-1}$으로 나타났는데 이 값은 2-3월의 웨델해와 유사한 수준이었다. 입자상 유기탄소 플럭스와 일차생산력의 비율로 나타낸 생물 펌프의 효율(ThE)은 3-54%(평균 28%) 범위였다.