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#1
Sheila A M Rauch, Anthony P King, Israel Liberzon, Rebecca K Sripada
BACKGROUND: Convergent evidence suggests that the hypothalamic-pituitary-adrenal (HPA) axis is disrupted in posttraumatic stress disorder (PTSD) and that HPA axis normalization may be associated with symptom improvement. Thus, the current study was designed to test the association between HPA axis reactivity and treatment response in psychotherapy for PTSD. METHODS: Thirty returning veterans with DSM-IV-TR PTSD were randomly assigned to receive 10 sessions of prolonged exposure therapy or present-centered therapy as part of a previously published randomized clinical trial (2008-2010)...
January 17, 2017: Journal of Clinical Psychiatry
#2
Yevgeniy Vinogradskiy, Matthew Jackson, Leah Schubert, Bernard Jones, Richard Castillo, Edward Castillo, Thomas Guerrero, John Mitchell, Chad Rusthoven, Moyed Miften, Brian Kavanagh
PURPOSE: A primary treatment option for lung cancer patients is surgical resection. Patients who have poor lung function prior to surgery are at increased risk of developing serious and life-threatening complications after surgical resection. Surgeons use nuclear medicine ventilation-perfusion (VQ) scans along with pulmonary function test (PFT) information to assess a patient's pre-surgical lung function. The nuclear medicine images and pre-surgery PFTs are used to calculate percent predicted postoperative (%PPO) PFT values by estimating the amount of functioning lung tissue that would be lost with surgical resection...
January 2017: Medical Physics
#3
Thomas M Fiedler, Mark E Ladd, Andreas K Bitz
PURPOSE: The purpose of this work was to perform an RF safety evaluation for a bilateral four-channel transmit/receive breast coil and to determine the maximum permissible input power for which RF exposure of the subject stays within recommended limits. The safety evaluation was done based on SAR as well as on temperature simulations. In comparison to SAR, temperature is more directly correlated with tissue damage, which allows a more precise safety assessment. The temperature simulations were performed by applying three different blood perfusion models as well as two different ambient temperatures...
January 2017: Medical Physics
#4
Sara Gholampourkashi, Miro Vujicic, Jason Belec, Joanna E Cygler, Emily Heath
PURPOSE: To evaluate a novel 4D Monte Carlo simulation tool by comparing calculations to physical measurements using a respiratory motion phantom. METHODS: We used a dynamic Quasar phantom in both stationary and breathing states (sinusoidal motion of amplitude of 1.8 cm and period of 3.3 s) for dose measurements on an Elekta Agility linear accelerator. Gafchromic EBT3 film and the RADPOS 4D dosimetry system were placed inside the lung insert of the phantom to measure dose profiles and point-dose values at the center of the spherical tumor inside the insert...
January 2017: Medical Physics
#5
Daisuke Kawahara, Shuichi Ozawa, Akito Saito, Teiji Nishio, Tomoki Kimura, Tatsuhiko Suzuki, Kazunari Hioki, Takeo Nakashima, Yoshimi Ohno, Yuji Murakami, Yasushi Nagata
PURPOSE: Stereotactic body radiation therapy (SBRT) combining trans-arterial chemoembolization (TACE) with Lipiodol is expected to improve local control. This study is aimed to estimate the dose enhancement in Lipiodol's proximity and to evaluate the dose calculation accuracy of the Acuros XB (AXB) algorithm and anisotropic analytical algorithm (AAA) in the Eclipse treatment planning system (TPS) (ver. 11, Varian Medical Systems, Palo Alto, USA), compared with that of the Monte Carlo (MC) calculation (using BEAMnrc/DOSXYZnrc code) for a virtual phantom and a treatment plan for liver SBRT after TACE...
January 2017: Medical Physics
#6
Blake R Smith, John A Micka, Manik Aima, Larry A DeWerd, Wesley S Culberson
PURPOSE: To perform an in-air air-kerma strength (SK) calibration of the Bebig model Ir2.A85-2 192Ir high-dose rate (HDR) brachytherapy source manufactured by Mallinckrodt Medical (Westerduinweg, Germany) with the NIST-traceable seven-distance technique established by the University of Wisconsin. A comparison was made between the reference air-kerma rate (RAKR) reported on a certificate from the Physikalisch-Technische Bundesanstalt (Berlin, Germany) (PTB) primary laboratory and the SK determined at the University of Wisconsin Madison Radiation Research Center (UWMRRC)...
January 2017: Medical Physics
#7
Kai Yang, Xinhua Li, X George Xu, Bob Liu
PURPOSE: To accurately measure the beam filter profiles from a variety of CT scanner models and to provide reference data for Monte Carlo simulations of CT scanners. METHODS: This study proposed a new method to measure CT beam filter profiles using a linear-array x-ray detector (X-Scan 0.8f3-512; Detection Technology Inc., Espoo, Finland) under gantry rotation mode. A robust geometrical calibration approach was developed to determine key geometrical parameters by considering the x-ray focal spot location relative to the linear-array detector and the gantry's angular increment at each acquisition point...
January 2017: Medical Physics
#8
J Martínez Ortega, N Gómez González, P Castro Tejero, M Pinto Monedero, N B Tolani, L Núñez Martín, R Sánchez Montero
PURPOSE: Amorphous silicon electronical portal imaging devices (EPIDs) are widely used for dosimetric measurements in Radiation Therapy. The purpose of this work was to determine if a portal dose prediction method can be utilized for dose map calculations based on the linear accelerator model within a commercial treatment planning system (Pinnacle(3) v8.0 m). METHODS: The method was developed for a 6 MV photon beam on the Varian Clinac 21-EX, at a nominal dose rate of 400 MU/min...
January 2017: Medical Physics
#9
Bedor Abualhaj, Guoyang Weng, Melissa Ong, Ali Asgar Attarwala, Flavia Molina, Karen Büsing, Gerhard Glatting
PURPOSE: Dynamic [(18) F]fluoro-ethyl-L-tyrosine positron emission tomography ([(18) F]FET-PET) is used to identify tumor lesions for radiotherapy treatment planning, to differentiate glioma recurrence from radiation necrosis and to classify gliomas grading. To segment different regions in the brain k-means cluster analysis can be used. The main disadvantage of k-means is that the number of clusters must be pre-defined. In this study, we therefore compared different cluster validity indices for automated and reproducible determination of the optimal number of clusters based on the dynamic PET data...
January 2017: Medical Physics
#10
Sulieman S Al-Johany, Mohammad D Al Amri, Ahmed S Al-Bakri, Mohammed N Al-Qarni
PURPOSE: To evaluate in vitro the effect of the size of the unfilled space of the abutment screw access hole on the amount of extruded excess cement and the retention of zirconia copings. MATERIALS AND METHODS: Twelve dental implant replicas were attached to the corresponding abutments and embedded in acrylic resin blocks. A total of 36 CAD/CAM zirconia copings were fabricated by one technician using the standard technique. Abutments were divided into group I: the entire screw access channel was completely filled (nonspaced); group II: 1-mm-spaced; and group III: 2-mm-spaced...
January 19, 2017: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
#11
Alwiena J Blignaut, Siedine K Coetzee, Hester C Klopper, Suria M Ellis
AIMS AND OBJECTIVES: To determine the incidence of medication administration errors, medication administration related deviations from safe practice as well as factors associated with these errors in medical and surgical units of public hospitals in the Gauteng Province of South Africa. BACKGROUND: Several studies have been published on the incidence of medication administration errors, but only a few have studied the incidence of medication administration related deviations from safe practice...
January 19, 2017: Journal of Clinical Nursing
#12
REVIEW
Julie McLellan, Carl J Heneghan, Rafael Perera, Alison M Clements, Paul P Glasziou, Karen E Kearley, Nicola Pidduck, Nia W Roberts, Sally Tyndel, F Lucy Wright, Clare Bankhead
BACKGROUND: Heart failure is a condition in which the heart does not pump enough blood to meet all the needs of the body. Symptoms of heart failure include breathlessness, fatigue and fluid retention. Outcomes for patients with heart failure are highly variable; however on average, these patients have a poor prognosis. Prognosis can be improved with early diagnosis and appropriate use of medical treatment, use of devices and transplantation. Patients with heart failure are high users of healthcare resources, not only due to drug and device treatments, but due to high costs of hospitalisation care...
December 22, 2016: Cochrane Database of Systematic Reviews
#13
J Jabbour, M Uhing, T Robey
OBJECTIVE: To calculate the prevalence of vocal fold paralysis (VFP) in preterm (<37 weeks of gestation) infants at a single neonatal intensive care unit (NICU) and identify risk factors for the development of VFP. STUDY DESIGN: This is a case control study of all surviving preterm infants admitted to the NICU at Children's Hospital of Wisconsin from 2006 to 2012, comparing those with and without VFP. Multivariate analysis was performed to identify significant risk factors for VFP...
January 19, 2017: Journal of Perinatology: Official Journal of the California Perinatal Association
#14
A Chen, C Xie, A M Vuong, T Wu, E A DeFranco
OBJECTIVE: The Institute of Medicine (IOM) 2009 gestational weight gain (GWG) guidelines are based on prepregnancy body mass index (BMI) categories. We intended to refine optimal GWG for each prepregnancy BMI unit in relation to the risk of small- and large-for-gestational-age (SGA and LGA) births, cesarean section (C-section) and infant death. STUDY DESIGN: We used data from 836,841 Ohio birth records from 2006 to 2012, and applied generalized additive models to calculate optimal GWG by prepregnancy BMI unit...
January 19, 2017: Journal of Perinatology: Official Journal of the California Perinatal Association
#15
Nadia Falzone, Boon Lee, José Fernández-Varea, Christiana Kartsonaki, Andrew Stuchbery, Tibor Kibedi, Katherine Vallis
AIM: The aim of this study was to investigate the impact of decay data provided by the newly developed stochastic atomic relaxation model <i>BrIccEmis</i> on dose point kernels (DPKs- radial dose distribution around a unit point source) and <i>S</i>-values (absorbed dose per unit cumulated activity) of 14 Auger electron (AE) emitting radionuclides, namely <sup>67</sup>Ga, <sup>80m</sup>Br, <sup>89</sup>Zr, <sup>90</sup>Nb, <sup>99m</sup>Tc, <sup>111</sup>In, <sup>117m</sup>Sn, <sup>119</sup>Sb, <sup>123</sup>I, <sup>124</sup>I, <sup>125</sup>I, <sup>135</sup>La, <sup>195m</sup>Pt and <sup>201</sup>Tl...
January 19, 2017: Physics in Medicine and Biology
#16
Shimin Cao, Jiaojiao Zhou, Xuan Wei, Shu-Guang Cheng
Massless charge carriers in gate potential modulate graphene quantum well transport in a same way that electromagnetic wave propagates in optical fibers. Recent experiment by Kim {\it et al} (Nat. Phys. 12 1022) reports the valley symmetry preserved transport in graphene carrier guider. Based on a tight-binding model, the valley resolved transport coefficients are calculated with the method of scattering matrix theory. For a straight potential well, valley resolved conductance is quantized with value $2n+1$ multiply $2e^2/h$ with integer $n$...
January 19, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
#17
Matthew Gardner, Ngonidzashe M Katsidzira, Erin Ross, Elizabeth A Larkin
OBJECTIVES: To establish a system for patient dosimetry audit and setting of Local Diagnostic Reference Levels (LDRLs) for Nuclear Medicine (NM) CT. METHODS: Computed Radiological Information System (CRIS) data were matched with NM paper records which provided the body region and dose mode for NMCT carried out at a large UK hospital. It was necessary to divide data in terms of the NM examination type, body region and dose mode. The mean and standard deviation Dose Length Products (DLPs) for common NMCT examinations were then calculated and compared to the proposed National DRLs (NDRLs)...
January 19, 2017: British Journal of Radiology
#18
Brian Kolb, Xuan Luo, Xueyao Zhou, Bin Jiang, Hua Guo
Ab initio molecular dynamics (AIMD) simulations of molecule-surface scattering allow first-principles characterization of the dynamics. However, the large number of density functional theory calculations along the trajectories are very costly, limiting simulations of long-time events. To avoid this computational bottleneck, we report here the development of a high-dimensional molecule-surface interaction potential energy surface (PES) with movable surface atoms, using a machine learning approach. With 60 degrees of freedom, this PES allows energy transfer between the impinging molecule and surface atoms...
January 19, 2017: Journal of Physical Chemistry Letters
#19
Minming Shen, Yuyang Zhang, Kaizhou Chen, Siying Che, Jia Yao, Haoran Li
The ionicity value, which is a key property of protic ionic liquids, was obtained by the attenuated total reflection Fourier transform infrared spectroscopy and nuclear magnetic resonance respectively for a protic ionic liquid: n-propylammonium acetate. The method of potentiometric titration is found not suitable for such kind of ionic liquid as the ∆pKa of the compositing acid and base is relatively small. In the IR spectrum, molecular species can be directly observed in the range 1200-1800 cm-1, and the ratio of ionic and molecular species can be quantitatively calculated by the area of characteristic absorption peaks calibrated by standard curve from NaAc/HAc solutions...
January 19, 2017: Journal of Physical Chemistry. B
#20
Helena Lundberg, Fredrik Tinnis, Jiji Zhang, Andrés G Algarra, Fahmi Himo, Hans Adolfsson
The mechanism of the zirconium-catalyzed condensation of carboxylic acids and amines for direct formation of amides was studied using kinetics, NMR-spectroscopy and DFT-calculations. The reaction is found to be first order with respect to catalyst and has a positive rate dependence on amine concentration and a negative rate dependence on carboxylic acid concentration. Kinetic experiments using Reaction Progress Kinetic Analysis (RPKA) protocols demonstrate that inhibition of the catalyst by the amide product can be avoided using a high amine concentration...
January 19, 2017: Journal of the American Chemical Society
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