The precision errors of dual-energy X-ray absorptiometry (DXA) measurements are important for monitoring osteoporosis. This study investigated the effect of body mass index (BMI) on precision errors for lumbar spine (LS), femoral neck (NOF), total hip (TH), and total body (TB) bone mineral density using the GE Lunar Prodigy. One hundred two women with BMIs ranging from 18.5 to 45.9 kg/m(2) were recruited. Participants had duplicate DXA scans of the LS, left hip, and TB with repositioning between scans. Participants were divided into 3 groups based on their BMI and the percentage coefficient of variation (%CV) calculated for each group. The %CVs for the normal (<25 kg/m(2)) (n=48), overweight (25-30 kg/m(2)) (n=26), and obese (>30 kg/m(2)) (n=28) BMI groups, respectively, were LS BMD: 0.99%, 1.30%, and 1.68%; NOF BMD: 1.32%, 1.37%, and 2.00%; TH BMD: 0.85%, 0.88%, and 1.06%; TB BMD: 0.66%, 0.73%, and 0.91%. Statistically significant differences in precision error between the normal and obese groups were found for LS (p=0.0006), NOF (p=0.005), and TB BMD (p=0.025). These results suggest that serial measurements in obese subjects should be treated with caution because the least significant change may be larger than anticipated.
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http://dx.doi.org/10.1016/j.jocd.2012.01.002 | DOI Listing |
Rev Sci Instrum
January 2025
School of Mechatronics Engineering, Anhui University of Science and Technology, Huainan 232001, China.
This paper presents a coaxial integrated macro-micro composite actuator. The macro-actuator of the macro-micro composite actuator is similar to a moving coil type voice coil motor, and a giant magnetostrictive actuator is installed coaxially inside it as a micro-actuator. In this work, kinetic models are established for both the macro-actuator and micro-actuator, and based on the models, an automatic disturbance rejection controller is adopted to control the macro-actuator, and a fuzzy sliding mode controller is adopted for the micro-actuator.
View Article and Find Full Text PDFAnal Methods
January 2025
Key Laboratory of Synthetic and Biological Colloids, Ministry of Education, School of Chemical and Material Engineering, Jiangnan University, Wuxi, Jiangsu 214122, P. R. China.
The field of electrochemical ammonia synthesis has made rapid advancements, attracting a large number of scientists to contribute to this area of research. Accurate detection of ammonia is crucial in this process for evaluating the efficiency and selectivity of electrocatalysts. In this study, we systematically investigate the indophenol blue method for ammonia detection, examining the effects of key factors such as solution pH, nitrate concentration, and metal ion concentration on measurement accuracy.
View Article and Find Full Text PDFFront Vet Sci
January 2025
Divison of Small Animal Surgery, Department of Clinical Veterinary Medicine, Vetsuisse-Faculty, University of Bern, Bern, Switzerland.
Introduction: Sacroiliac luxation is a common traumatic feline injury, with the small size of the sacral body being a challenge for surgical stabilization. This study compared an innovative computer-guided drilling method with the conventional fluoroscopy-controlled freehand technique. Neuronavigation, using CT-based planning and real-time tracking, was evaluated against the freehand method for accuracy and time efficiency.
View Article and Find Full Text PDFEur Radiol Exp
January 2025
Imaging Institute of Southern Switzerland, Ente Ospedaliero Cantonale, Lugano, Switzerland.
Background: Body composition scores allow for quantifying the volume and physical properties of specific tissues. However, their manual calculation is time-consuming and prone to human error. This study aims to develop and validate CompositIA, an automated, open-source pipeline for quantifying body composition scores from thoraco-abdominal computed tomography (CT) scans.
View Article and Find Full Text PDFSpectrochim Acta A Mol Biomol Spectrosc
January 2025
Key Laboratory of Spectral Imaging Technology, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119 China. Electronic address:
Non-optically active water quality parameters (NAWQPs) are essential for surface water quality assessments, although automated monitoring methods are time-consuming, include labor-intensive chemical pretreatment, and pose challenges for high spatiotemporal resolution monitoring. Advancements in spectroscopic techniques and machine learning may address these issues. We integrated ultraviolet-visible-near infrared absorption spectroscopy with physical-chemical measurements to predict total nitrogen (TN), dissolved oxygen (DO), and total phosphorus (TP) in the Yangtze River Basin, China.
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