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Dual energy

Matilda Baptist, Candace Panagabko, Shamshad Cockcroft, Jeffrey Atkinson
Phosphatidylinositol transfer proteins (PITPs) are believed to be lipid transfer proteins because of their ability to transfer either phosphatidylinositol (PI) or phosphatidylcholine (PC) between membrane compartments, in vitro. However, the detailed mechanism of this transfer process is not fully established. To further understand the transfer mechanism of PITPs we examined the interaction of PITPs with membranes using dual polarization interferometry (DPI), which measures protein binding affinity on a flat immobilized lipid surface...
April 18, 2016: Biochemistry and Cell Biology, Biochimie et Biologie Cellulaire
Kelly A Mackintosh, Martyn Standage, Amanda E Staiano, Leanne Lester, Melitta A McNarry
OBJECTIVE: This study investigated the effect of acute exergaming on the physiological and psychosocial responses of young adults and the modulatory effect of a single- or dual-player game play situation. MATERIALS AND METHODS: Thirty-six participants (19 male; 21.7 ± 3.8 years; 23.65 ± 3.17 kg/m(2)) each completed two 30-minute exergame sessions in a randomized order (single and dual player) while wearing an Actiheart(®) to estimate energy expenditure...
October 26, 2016: Games for Health
I Raška, M Rašková, V Zikán, J Škrha
Type 2 diabetes mellitus (T2DM) is associated with increased fracture risk; the underlying mechanism remains unexplained. This study aimed to investigate the relationships between body composition and bone and glucose metabolism in postmenopausal women with T2DM. Dual-energy X-ray absorptiometry was used to measure bone mineral density (BMD) and body composition. A total of 68 postmenopausal women with T2DM and 71 controls were eligible for the study. In contrast to normal BMD in T2DM, a similar prevalence of low-trauma fractures was observed in both groups...
October 26, 2016: Physiological Research
Paul Prior, Rachel Timmins, Julia Petryk, Jared Strydhorst, Yin Duan, Lihui Wei, R Glenn Wells
PURPOSE: In dual-isotope (Tc-99m/In-111) small-animal single-photon emission computed tomography (SPECT), quantitative accuracy of Tc-99m activity measurements is degraded due to the detection of Compton-scattered photons in the Tc-99m photopeak window, which originate from the In-111 emissions (cross talk) and from the Tc-99m emission (self-scatter). The standard triple-energy window (TEW) estimates the total scatter (self-scatter and cross talk) using one scatter window on either side of the Tc-99m photopeak window, but the estimate is biased due to the presence of unscattered photons in the scatter windows...
October 2016: Medical Physics
Vicki T Taasti, Jørgen B B Petersen, Ludvig P Muren, Jesper Thygesen, David C Hansen
PURPOSE: In this study the authors present a new method for estimation of proton stopping power ratios (SPRs) using dual energy CT (DECT), which is robust toward CT noise. The authors propose a parametrization for SPR based directly on the CT numbers in a DECT image set, whereby the intermediate steps of estimating the relative electron density, ρe, and mean excitation energy, I, are avoided. METHODS: The SPR parametrization proposed in this study is a purely empirical fit based on the theoretical SPR values for a list of 34 reference human tissues...
October 2016: Medical Physics
Huanjun Ding, David Sennung, Hyo-Min Cho, Sabee Molloi
PURPOSE: The positive predictive power for malignancy can potentially be improved, if the chemical compositions of suspicious breast lesions can be reliably measured in screening mammography. The purpose of this study is to investigate the feasibility of quantifying breast lesion composition, in terms of water and lipid contents, with spectral mammography. METHODS: Phantom and tissue samples were imaged with a spectral mammography system based on silicon-strip photon-counting detectors...
October 2016: Medical Physics
Steven Michiels, Antoine D'Hollander, Nicolas Lammens, Mathias Kersemans, Guozhi Zhang, Jean-Marc Denis, Kenneth Poels, Edmond Sterpin, Sandra Nuyts, Karin Haustermans, Tom Depuydt
PURPOSE: 3D printing technology is investigated for the purpose of patient immobilization during proton therapy. It potentially enables a merge of patient immobilization, bolus range shifting, and other functions into one single patient-specific structure. In this first step, a set of 3D printed materials is characterized in detail, in terms of structural and radiological properties, elemental composition, directional dependence, and structural changes induced by radiation damage. These data will serve as inputs for the design of 3D printed immobilization structure prototypes...
October 2016: Medical Physics
K Müller, S Datta, M Ahmad, J-H Choi, T Moore, L Pung, C Niebler, G E Gold, A Maier, R Fahrig
PURPOSE: In the last years, dual-energy CT imaging has shown clinical value, thanks to its ability to differentiate materials based on their atomic number and to exploit different properties of images acquired at two different energies. C-arm CT systems are used to guide procedures in the interventional suite. Until now, there are no commercially available systems that employ dual-energy material decomposition. This paper explores the feasibility of implementing a fast kV-switching technique on a clinically available angiographic system for acquiring dual-energy C-arm CT images...
October 2016: Medical Physics
F Minary, D Rabus, G Martin, J-M Friedt
Stroboscopy provides an energy and computationally efficient means of sampling radiofrequency and microwave signals assumed to be reproducible under external excitation. While well known for impulse mode RADAR receivers, we here investigate its use for interrogating surface acoustic wave (SAW) transducers acting as passive cooperative targets. Amongst the originality of the implementation is the need to keep phase coherence between successive pulse generations which last up to tens of the radiofrequency periods to optimally transfer energy to the transducer...
September 2016: Review of Scientific Instruments
Fengyan Wang, Kopin Liu
When a CHD3 molecule is pumped to the C-H stretching-excited state by absorbing a linearly polarized infrared (IR) photon via the R(0) branch of the v1 = 1←0 transition, the rotational angular momentum j of the prepared state jK=10 preferentially lies in a plane perpendicular to the IR polarization axis εIR. By way of contrast, when the Q(1) branch is used, the state of jK=1±1 is prepared with j aligned along the direction of εIR. Reported here is a detailed study of the title reaction by actively controlling the collision geometries under these two IR-excitation schemes at collision energy Ec = 8...
October 14, 2016: Journal of Chemical Physics
Joel D Leger, Clyde Varner, Igor V Rubtsov
Fifth-order multidimensional infrared spectroscopy with heterodyned detection was carried out in the three-beam dual-frequency configuration. Numerous 5th-order cross peaks were detected for the 4-azidobutyrate-N-hydroxysuccinimide ester compound in solution involving several vibrational modes ranging in frequency from 1045 to 2100 cm(-1). Cross peaks involving overtones (2X/Z) and combination bands (XY/Z) among the tags, modes X and Y excited by the first two mid-IR laser pulses, and the reporter, modes Z excited by the third laser pulse, were acquired and the factors affecting the amplitude of 5th-order cross peaks are discussed...
October 21, 2016: Journal of Chemical Physics
Jin Lee, Hyun-Kyung Park, Ja Hye Kim, Yun Young Choi, Hyun Ju Lee
BACKGROUND: To examine bone mineral density in extremely low birth weight infants at discharge and investigate whether serial measurements of serum alkaline phosphatase (ALP) and phosphate can predict bone mineralization. METHODS: The individuals were 70 preterm infants. Serum calcium, phosphate, and ALP were measured at weekly intervals during admission in extremely low birth weight infants (mean gestational age, 25.3±2.1 weeks; birth weight, 812.8±141.1 g)...
September 30, 2016: Pediatrics and Neonatology
Joel T Cramer, Alfonso J Cruz-Jentoft, Francesco Landi, Mary Hickson, Mauro Zamboni, Suzette L Pereira, Deborah S Hustead, Vikkie A Mustad
BACKGROUND: Recent evidence suggests that nutritional interventions may improve muscle outcomes in malnutrition and sarcopenia. OBJECTIVES: We evaluated the effects of 2 high-quality oral nutritional supplements (ONS) differing in amount and type of key nutrients in older adult men and women. DESIGN: A multicenter, randomized, double-blinded, controlled clinical trial. PARTICIPANTS: Malnourished and sarcopenic men and women, 65 years and older (n = 330)...
November 1, 2016: Journal of the American Medical Directors Association
Yong Li, Wen-Bo Zhao, De-Li Wang, Qing He, Qin Li, Fu-Xing Pei, Lei Liu
OBJECTIVE: To observe the clinical results of proximal femoral nail anti-rotation (PFNA) combined with zoledronic acid injection in the treatment of osteoporotic intertrochanteric fractures in the elderly. METHODS: 60 elderly patients with osteoporotic intertrochanteric fractures were diagnosed using a dual energy X-ray bone density instrument. Patients were randomly divided into treatment or control groups (30 cases in each group). Patients in both groups were treated by closed/open reduction and internal fixation using PFNA...
October 1, 2016: Chinese Journal of Traumatology, Zhonghua Chuang Shang za Zhi
Jacynthe Lafrenière, Denis Prud'homme, Martin Brochu, Rémi Rabasa-Lhoret, Jean-Marc Lavoie, Éric Doucet
PURPOSE: The association between the energy density (ED) of foods and adiposity has been reported previously. However, whether the contribution of ED to adiposity remains significant when controlled for energy intake (EI) and physical activity energy expenditure (PAEE) remains to be clearly established. We aimed to investigate the independent contribution of ED to variations in body composition in women during the menopausal transition. METHODS: Sixty-seven women from the MONET cohort study were analyzed...
October 25, 2016: Canadian Journal of Dietetic Practice and Research
Hao Liu, Wei Ye, Hai-Feng Chen
Acetylcholinesterase is a potent enzyme that regulates neurotransmission by rapidly hydrolyzing the neurotransmitter acetylcholine in synapses of the nervous system. As drug target of anti-AD, it has catalytic and peripheral anionic sites. However, the regulation relation between these two sites is unclear. Therefore, we constructed dynamics fluctuation network based on all-atom molecular dynamics simulations to reveal the regulation mechanism. The results suggest that the correlation network in double site system (hAChE/TZ5) is distinctly different from that in the free state and single site systems (hAChE/huprine and hAChE/1YL)...
October 25, 2016: Chemical Biology & Drug Design
Arthur Lalonde, Hugo Bouchard
To develop a general method for human tissue characterization with dual- and multi-energy CT and evaluate its performance in determining elemental compositions and quantities relevant to radiotherapy Monte Carlo dose calculation. Ideal materials to describe human tissue are obtained applying principal component analysis on elemental weight and density data available in literature. The theory is adapted to elemental composition for solving tissue information from CT data. A novel stoichiometric calibration method is integrated to the technique to make it suitable for a clinical environment...
November 21, 2016: Physics in Medicine and Biology
J D Thiessen, E Shams, G Stortz, G Schellenberg, D Bishop, M S Khan, P Kozlowski, F Retière, V Sossi, C J Thompson, A L Goertzen
A full-ring PET insert consisting of 16 PET detector modules was designed and constructed to fit within the 114 mm diameter gradient bore of a Bruker 7 T MRI. The individual detector modules contain two silicon photomultiplier (SiPM) arrays, dual-layer offset LYSO crystal arrays, and high-definition multimedia interface (HDMI) cables for both signal and power transmission. Several different RF shielding configurations were assessed prior to construction of a fully assembled PET insert using a combination of carbon fibre and copper foil for RF shielding...
November 21, 2016: Physics in Medicine and Biology
Yusif Abdullayev, Vagif Abbasov, Lucas C Ducati, Avtandil Talybov, Jochen Autschbach
The mechanisms of a tetrasubstituted imidazole [2-(2,4,5-triphenyl-1 H-imidazol-1-yl)ethan-1-ol] synthesis from benzil, benzaldehyde, ammonium acetate, and ethanolamine in [Et2NH2][HSO4] ionic liquid (IL) are studied computationally. The effects of the presence of the cationic and anionic components of the IL on transition states and intermediate structures, acting as a solvent versus as a catalyst, are determined. In IL-free medium, carbonyl hydroxylation when using a nucleophile (ammonia) proceeds with a Gibbs free energy (ΔG(≠)) barrier of 49...
October 2016: ChemistryOpen
Joshua H F Cooper, Blake E G Collins, David R Adams, Robert A Robergs, Cheyne E Donges
Purpose. Limited data exists for the effects of sprint-interval training (SIT) and endurance training (ET) on total body composition, abdominal visceral adipose tissue, and plasma inflammation. Moreover, whether "active" or "passive" recovery in SIT provides a differential effect on these measures remains uncertain. Methods. Sedentary middle-aged men (n = 62; 49.5 ± 5.8 y; 29.7 ± 3.7 kg·m(2)) underwent abdominal computed tomography, dual-energy X-ray absorptiometry, venepuncture, and exercise testing before and after the interventions, which included the following: 12 wks 3 d·wk(-1) ET (n = 15; 50-60 min cycling; 80% HRmax), SIT (4-10 × 30 s sprint efforts) with passive (P-SIT; n = 15) or active recovery (A-SIT; n = 15); or nonexercise control condition (CON; n = 14)...
2016: Journal of Obesity
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