• 제목/요약/키워드: Dual energy

검색결과 1,045건 처리시간 0.033초

하악골 골염도의 정량적 평가에 관한 비교연구 (A Comparative Study of Quantitative Assessment of Bone Mineral Density of the Mandible)

  • 박원길;최의환;김재덕
    • 치과방사선
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    • 제29권1호
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    • pp.161-173
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    • 1999
  • This study was performed to compare the bone mineral densities measured at mandibular premolar area by copper-equivalent image and hydroxyapatite phantom with those measured at radius by dual energy absorptiometry and to evaluate the clinical usefulness of Digital system with slide scanner, copper-equivalent image, and hydroxyapatite phantom. For experiment. intraoral radiograms of 15 normal subjects ranged from 20 years old to 67 old were taken with copper-step wedge at mandibular premolar area and bone mineral densities calculated by conversion equation to bone mineral density of hydroxyapatite were compared with those measured at radius distal 1/3 area by Hologic QDR-1000. Obtained results as follows: 1) The conversion equation was Y=5.97X-0.25 and its determination coefficient was 0.9967. The coefficient of variation in the measurement of copper-equivalent value ranged from 4% to 8% and showed high reproducibility. 2) The coefficient of variation in the measurement of bone mineral density by the equation ranged from 7% to 8% and showed high reproducibility. 3) The bone mineral densities ranged from 0.35 to 0.79g/cm2 at mandibular premolararea. 4) The correlation coefficient between bone mineral densities at mandibular premolar area and those at radius distal 1/3 area was 0.8965. As summary, digital image analyzing system using copper-equivalent image and hydroxyapatite phantom appeared to be clinically useful to measure the bone mineral density at dental area.

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연령과 골소주 특성의 골량에 대한 연관관계 (Relationship of bony trabecular characteristics and age to bone mass)

  • 최동훈;송영한;윤영남;이완;이병도
    • Imaging Science in Dentistry
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    • 제36권2호
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    • pp.95-101
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    • 2006
  • Purpose : Bony strength is dependent on bone mass and bony structure. So this study was designed to investigate the relationship between the bone mass and bony trabecular characteristics. Subjects and Methods : Study subjects were 51 females (average age 68.6 years) and 20 males (average age 66.4 years). Bone mineral density (BMD, $grams/cm^2$) of proximal femur was measured by a dual energy X-ray absorptiometry (DEXA). Regions of interest (ROIs) were selected from the digitized radiographs of proximal femur. A customized computer program processed morphologic operations (MO) of ROIs. 44 skeletal variables of MO were calculated from ROIs on the Ward's triangle and greater trochanter of femur. WHO BMD classes were predicted by MO variables of the same ROI. Classification and Regression Tree analysis was used for calculating weighted kappa values, sensitivity and specificity of MO. Results : The discriminating factors of morphologic operation were branch point, branch point [per cm sq]. Age also played important role in distinguishing osteoporotic classes. The sensitivity of MO at Ward's triangle and Greater Trochanter was 91.8%, 65.6%, respectively. The specificity of MO was 100% at Ward's triangle and Greater Trochanter. Conclusion : Bony trabecular characteristics obtained using radiological bone morphometric analysis seem to be related to bone mass.

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체지방에 대한 아로니아 추출물의 효과: 무작위배정, 이중눈가림, 위약-대조 임상연구 (The Effects of Aronia Extract on Body Weight and Body Fat: A Randomized, Double-Blind, Placebo-Controlled Clinical Trial)

  • 하기찬;박유경;백향임;김혜미;김영미;정다영;신상욱;배정식;안지혜;전연정;박지은;권영달
    • 한방재활의학과학회지
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    • 제30권1호
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    • pp.105-113
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    • 2020
  • Objectives Excess weight and obesity are a crucial public health problem worldwide and are considered as the main cause of many chronic diseases. The present study evaluated the effects of Aronia melanocarpa extract (AMEX) supplementation on body compositions in overweight or obese people. Methods This randomized, double-blind, placebo-controlled clinical trial was carried out on 66 healthy overweight or obese peoples. The eligible subjects were divided into AMEX and placebo supplement treatment for 12 weeks. Anthropometrics, body composition (dual-energy X-ray absorptiometry), and blood analysis were performed preand post intervention. Results We observed significant reductions in the body weight and body mass index in both groups; however, the decrease was higher in the AMEX group. Body fat mass and percent body fat showed a tendency to decreases after AMEX supplementation. No clinically significant changes were observed for any safety parameter. Conclusions In conclusion, the data of this trial indicate that AMEX were not effective in reducing body compositions, but as a safe supplement, it may help weight loss in overweight or obese people.

골밀도와 수냉증과의 상관성 연구 (A Study on the Correlation between of Bone Mineral Density and Cold Hypersensitivity of Hands)

  • 이동녕;이정임;고호연;김형준
    • 대한한방부인과학회지
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    • 제28권4호
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    • pp.11-20
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    • 2015
  • Objectives The purpose of this study was to examine the relationship between cold hypersensitivity and bone mineral density. Methods 28 outpatients who visited OO University Oriental Hospital from July 11th, 2013 to August 28th, 2013 were analyzed. Patients were subjected to thermometer, and those with thermal difference greater than 0.3 ℃ between upper arm and palm and also with more than VAS 4 of cold hypersensitivity were diagnosed with cold sensitivity. Lumba spine (L2-4) and heel bone measurement were obtained on dual energy X-ray absorptiometry (DEXA) and Quantitative Computed Tomography (QCT). Results 1. There was statistically significant correlation between T-score of DEXA and body weight (0.522), BMI (0.643), OSTA (Osteoporosis elf-assesment Tool for Asians, 0.579), BMI, T-score and Z-score of QCT. OSTA and T-score of QCT (0.521) also had statistically significance. 2. There was no statistically significant correlation between body fat, abdominal obesity rate, degree of cold hypersensitivity, upper arm and palm's temperature difference, palm temperature, height and Z-score, T-score of QCT or T-sore of DEXA. Conclusions Bone mineral density was lower in women who had cold hypersensitivity of hand and feet. But there was no statistically significant correlation between bone mineral density and degree of cold hypersensitivity, upper arm and palm’s temperature difference.

한국 성인 비만여성의 체지방 분포와 월경 장애의 상관성 분석 (Relationship between body fat distribution and menstrual disorder in Obese Pre-menopausal Korean Women)

  • 최가야;송미연;신현대;정원석
    • 한방비만학회지
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    • 제4권1호
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    • pp.23-31
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    • 2004
  • Background: Obesity is associated with menstrual disorder. Especially, upper-body obesity affects on female reproductive function. Objectives: The goals were to investigate relation between fat distribution and menstrual disorder in obese pre-menopausal Korean females. The hypothesis were tested that there is a relation between upper body obesity and menstrual disorder. Design: A cross-sectional evaluation of 66 Females (baseline age $32.15{\pm}7,32)$ with body mass index $31.22{\pm}4.05\;kg/m^2$. Body composition was measured using bioimpedence analysis (BIA) and anthropometry was done by same observer. VAS and Multidimensional verval rating scale(MVRS) were checked for menstrual pain. Dual-Energy X-ray Absorptiometry (DXA) was measured for evaluating body fat distribution. Menstrual disorder and body fat distribution were compared using statistical methods. Results: TLFR and WH ratio was higher in menstrual cyclic disorder group than controls. There was negative relationship between VAS and TLFR. Conclusions: The data shows that disorder of menstrual cycle was associated with upper body obesity. WH ratio could be one of the factor of menstrual disorder. VAS was correlated with lower body obesity. Further studies for role of upper body fat distribution on female reproductive function and relationship between menstrual pain and fat distribution thought to be needed.

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자동변속기 클러치 디스크 마찰특성의 실험적 분석 (Experimental Analysis of an Automatic Transmission Clutch Disk Friction Characteristics)

  • 정규홍;박동훈;나두현
    • 드라이브 ㆍ 컨트롤
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    • 제15권3호
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    • pp.14-20
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    • 2018
  • Wet clutches in an automatic transmission enable the transmission of the engine power by the frictional torque experienced and noted between disk and plates. Since the clutch frictional torque considerably affects the shift quality of an automatic transmission as well as the durability of the machinery, its friction characteristics must be carefully examined to meet the design requirements. The SAE No. 2 friction test machine is a well-known standard to evaluate mainly the friction characteristics of plate clutches along with the required automatic transmission fluids. This paper reviews the experimental analysis of the wet clutch friction characteristics by using the exclusively developed clutch test machine which is capable of controlling the clutch test procedure, in accordance with the applicable test standard and processing of the experimental data automatically. As the clutch test machine is designed for the accommodation of dual clutches which is applied to the real transmission, it can evaluate not only the clutch friction characteristics, but also an actuation performance of a measured clutch piston. In respect to friction characteristics involving dynamic friction coefficients, the energy absorbed in a clutch disk and the recorded temperatures of clutch plates during braking actions and procedures are also investigated. Additionally, the change of friction coefficients by the use of the repeated clutch application is also observed with the endurance test functions of an accurately calibrated and dedicated clutch test machine.

Study on Relationship between Tumor Necrosis $Factor-\alpha$ Gene Polymorphism and Obese Patients

  • Kang Byung-Ku;Lee Si-Hyeong;Shin Jo-Young
    • 대한한의학회지
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    • 제26권1호
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    • pp.85-92
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    • 2005
  • Objective: A number of candidate genes have been in implicated in the pathogenesis of obesity in humans. Tumor necrosis factor-alpha $(TNF-{\alpha})$ is expressed primarily in adipocytes, and elevated levels of this cytokine have been linked to obesity and insulin resistance. Recently, the A allele of a polymorphism at position 308 in the promoter region of $TNF-{\alpha}$ (G-308A) has been shown to increase transcription of the gene in adipocytes. Therefore, we designed this study to test whether obese and non-obese subjects differ in $TNF-{\alpha}$ genotype distribution, and how the genotypes affect anthropometric parameters, including degrees of body mass index (BMI). Methods : The study included 153 obese but otherwise healthy women ($BMI{\geq}kg/m^2$, range 25-54.7, age range 15-40 years) and 82 non-obese healthy women ($BMI, age range 15-40 years). Total fat mass and percent body fat were determined by dual-energy X-ray absorptiometry. Genomic DNA was extracted and used for Ncol restriction fragment length polymorphism (RFLP) based genotyping of $TNF-{\alpha}$. Results: No differences were observed for allelic and genotype frequencies between the obese ($BMI{\geq}25$) and non-obese women. Also, no association of TNF-(l polymorphism was observed with body mass index (BMI) for genotype in obese women. In addition, age, pertent body fat, BMI, and cholesterol levels did not differ by $TNF-{\alpha}$ genotype. However, waist-to­hip ratio (WHR) was significantly lower in subjects with $TNF-{\alpha}$ GA or AA genotype (0.94 0.07 vs. 0.920.03, P<0.005). Conclusion: These results suggest that $TNF-{\alpha}$ promoter polymorphism at position-308 is not a significant factor for BMI, but affects the WHR in obese healthy women from Koreans.

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Radiative transfer analysis for Amon-Ra instrument

  • Seong, Se-Hyun;Ryu, Dong-Ok;Lee, Jae-Min;Hong, Jin-Suk;Kim, Seong-Hui;Yoon, Jee-Yeon;Park, Won-Hyun;Lee, Han-Shin;Park, Jong-Soo;Yu, Ji-Woong;Kim, Sug-Whan
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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    • pp.28.4-29
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    • 2009
  • The 'Amon-Ra' instrument of the proposed 'EARTHSHINE' satellite is a dual (i.e. imaging and energy) channel instrument for monitoring the total solar irradiance (TSI) and the Earth's irradiance at around the L1 halo orbit. Earlier studies for this instrument include, but not limited to, design and construction of breadboard Amon-Ra imaging channel, stray light suppression and system performance computation using Integrated Ray Tracing (IRT) technique. The Amon-Ra instrument is required to produce 0.3% in uncertainty for both Sunlight and Earthlight measurement. In this study, we report accurate estimation of the output electric signal derived from the orbital variation of radiant exitance from the Sun and the Earth arriving at the aperture and detector plane of the Amon-Ra. For this, orbital irradiance are computed analytically first and then confirmed by simulation using Integrated Ray Tracing (IRT) model. Specially, the results show the arriving power at the bolometer detector surface is $1.24{\mu}W$ for the Sunlight and $1.28{\mu}W$ for the Earthlight, producing the output signal pulses of 34.31 mV and 35.47 mV respectively. These results demonstrate successfully that the arriving radiative power is well within the bolometer detector dynamic range and, therefore, the proposed detector can be used for the in-orbit measurement sequence. We discuss the computational details and implications as well as the simulation results.

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유체 흐름 안에서 두 종의 생물막 성장 시뮬레이션 모델 (Simulation Model of Dual-Species Biofilm Growth in Hydrodynamic Flow)

  • 전원주;이상희
    • 한국시뮬레이션학회논문지
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    • 제20권1호
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    • pp.97-105
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    • 2011
  • 하천에서, 생물막은 녹갈색의 얇은 막의 형태로 돌, 식물, 그리고 기타 구조물의 표면에 부착되어 있다. 생물막은 주로 영양물의 순환, 수질정화, 바닥 침전물 제거, 그리고 먹이사슬내의 에너지 흐름에 매우 중요한 역할을 한다. 본 연구에서, 우리는 유체 흐름 안에서, 독소-생산 종과 독소-민감 종의 복합적 생물막을 전산 모사하는 모델을 개발하였다. 유체 흐름으로는 균일한 흐름과 불 균일한 흐름 두 가지를 고려하였다. 균일한 흐름은 확률 프로세스로 구현되었으며, 불 균일한 흐름은 나비어-스톡스 방정식으로 구현되었다. 모델에서, 독소-생산종과 독소-민감종 간의 상호작용을 고려하기 위해, 종 개체의 번식률과 사망률이 고려되어졌다. 우리는 서로 다른 두 유체 흐름 내에서 전산 모사 되어진 생물막의 구조적 형상에 대해서 간략히 논의 하였다.

요추관 협착증과 골밀도와의 상관성에 관한 임상례 보고 (Correlation between lumbar spinal stenosis and bone mineral density : a clinical survey of 9 cases)

  • 송주현;강인;임명장;김하늘;이제균;장형석
    • 척추신경추나의학회지
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    • 제1권1호
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    • pp.105-111
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    • 2006
  • Objective : The aim of this study was to evaluate association between lumbar spinal stenosis, one of degenerative diseases, and bone mineral density. Methods : We monitored 9 lumbar spinal stenosis patients in women above 50 years, visiting outpatient clinic of the Jaseng Oriental Medicine Hospital between January 5 2006 and March 31, 2006. They were diagnosed by radiologist ist after taking Magnetic Resonance Imaging(MRI). The cases were Investigated the bone mineral density using Dual Energy X-ray Absorptiomerty(DEXA). and then Picture Archiving Communication System(PACS) were used to assess correlation between lumbar spinal stenosis and bone mineral density. Results : 1. In comparison of the spinal canal area and lumbar spine 2 level bone mineral density, the data showed a significant result 2. The data, between spinal canal area and lumbar spine 1-2 level bone mineral density, indicated a significant result. 3. Also, the result of comparison between spinal canal area and the lowest value of bone mineral density showed significance. Conclusions : It showed that there is a statistically significant correlation between lumbar spinal stenosis and bone mineral density.

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