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Shinji Wada, Richard F Jordan
The discrete (phosphinoarenesulfonate)Pd fluoride complex (PO(Bp,OMe) )PdF(lutidine), where PO(Bp,OMe) =(2-MeOC6 H4 )(2-{2,6-(MeO)2 C6 H3 }C6 H4 )(2-SO3 -5-MeC6 H3 )P, inserts vinyl fluoride (VF) to form (PO(Bp,OMe) )PdCH2 CHF2 (lutidine) and inserts multiple ethylene (E) units to generate polyethylene that contains -CH2 F chain ends. These results provide strong evidence that the -CHF2 and -CH2 F chain ends in E/VF copolymer generated by (phosphinoarenesulfonate)PdR catalysts form by β-F elimination of Pd(β-F-alkyl) species, VF or E insertion of the resulting (PO)PdF species, and subsequent chain growth...
January 12, 2017: Angewandte Chemie
Anna Clebone, Barbara K Burian, Scott C Watkins, Jorge A Gálvez, Justin L Lockman, Eugenie S Heitmiller
Cognitive aids such as checklists are commonly used in modern operating rooms for routine processes, and the use of such aids may be even more important during critical events. The Quality and Safety Committee of the Society for Pediatric Anesthesia (SPA) has developed a set of critical-event checklists and cognitive aids designed for 3 purposes: (1) as a repository of the latest evidence-based and expert opinion-based information to guide response and management of critical events, (2) as a source of just-in-time information during critical events, and (3) as a method to facilitate a shared understanding of required actions among team members during a critical event...
January 10, 2017: Anesthesia and Analgesia
Roxana Simona Redis, George Adrian Calin
In recent years, understanding the crucial role played by cellular homeostasis in disease initiation and progression became the focus of scientists and clinicians. This SnapShot sketches the involvement of both short microRNAs and long ncRNAs in the major metabolic pathways altered in diseases. To view this SnapShot, open or download the PDF.
January 10, 2017: Cell Metabolism
Alexandra Vaccaro, Abdul-Raouf Issa, Laurent Seugnet, Serge Birman, André Klarsfeld
Circadian clocks control many self-sustained rhythms in physiology and behavior with approximately 24-hour periodicity. In many organisms, oxidative stress and aging negatively impact the circadian system and sleep. Conversely, loss of the clock decreases resistance to oxidative stress, and may reduce lifespan and speed up brain aging and neurodegeneration. Here we examined the effects of clock disruptions on locomotor aging and longevity in Drosophila. We found that lifespan was similarly reduced in three arrhythmic mutants (ClkAR, cyc0 and tim0) and in wild-type flies under constant light, which stops the clock...
January 2017: PLoS Genetics
Mazen Ahmad, Volkhard Helms, Olga V Kalinina, Thomas Lengauer
New exact equations are derived for the terms contributing to the binding free energy (ΔG(0)) of a ligand-receptor pair using our recently introduced formalism which we here call perturbation-divergence formalism (PDF). Specifically, ΔG(0) equals the sum of the average of the perturbation (pertaining to new interactions) and additional dissipative terms. The average of the perturbation includes the sum of the average receptor-ligand interactions and the average of the change of solvation energies upon association...
January 7, 2017: Journal of Chemical Physics
Brett F BuSha, George Banis
Human breathing patterns contain both temporal scaling characteristics, and an innately random component. A stochastic and mathematically integrative model of breathing (SIMB) that simulated the natural random and fractal-like pattern of human breathing was designed using breath-to-breath interval (BBI) data recorded from 14 healthy subjects. Respiratory system memory was estimated with autocorrelation, and a probability density function (PDF) was created by fitting a polynomial curve to each normalized BBI sequence histogram...
January 3, 2017: Respiratory Physiology & Neurobiology
Frithjof Kruggel, Fumitaro Masaki, Ana Solodkin
BACKGROUND & NEW METHOD: The widely used framework of voxel-based morphometry for analyzing neuroimages is extended here to model longitudinal imaging data by exchanging the linear model with a linear mixed-effects model. The new approach is employed for analyzing a large longitudinal sample of 756 diffusion-weighted images acquired in 177 subjects of the Alzheimer's Disease Neuroimaging initiative (ADNI). RESULTS AND COMPARISON WITH EXISTING METHODS: While sample- and group-level results from both approaches are equivalent, the mixed-effect model yields information at the single subject level...
January 2, 2017: Journal of Neuroscience Methods
Avan Al-Saffar, Eun-Jin Kim
Information theory provides a useful tool to understand the evolution of complex nonlinear systems and their sustainability. In particular, Fisher information has been evoked as a useful measure of sustainability and the variability of dynamical systems including self-organising systems. By utilising Fisher information, we investigate the sustainability of the logistic model for different perturbations in the positive and/or negative feedback. Specifically, we consider different oscillatory modulations in the parameters for positive and negative feedback and investigate their effect on the evolution of the system and Probability Density Functions (PDFs)...
January 2, 2017: Mathematical Biosciences
Graham King, Corey M Thompson, Kun Luo, John E Greedan, Michael A Hayward
Neutron pair distribution function data are used to investigate the local structures of two oxygen deficient perovskites with simple cubic crystal structures. La0.5Ba0.5MnO2.5 is found to have alternating layers of MnO6 octahedra and MnO4 tetrahedra, making it similar to other members of the La1-xBaxMnO2.5 series with smaller x values which have brownmillerite crystal structures. Our fitting results suggest that La0.5Ba0.5MnO2.5 is not locally similar to any one brownmillerite structure type but instead has a variety of intra-layer and inter-layer relationships...
January 5, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
M Belley, M Schmidt, N Knutson, M Price
PURPOSE: Physics second-checks for external beam radiation therapy are performed, in-part, to verify that the machine parameters in the Record-and-Verify (R&V) system that will ultimately be sent to the LINAC exactly match the values initially calculated by the Treatment Planning System (TPS). While performing the second-check, a large portion of the physicists' time is spent navigating and arranging display windows to locate and compare the relevant numerical values (MLC position, collimator rotation, field size, MU, etc...
June 2016: Medical Physics
D Hall, A Trofimov, B Winey, N Liebsch, H Paganetti
PURPOSE: We developed a knowledge-based model that can predict the patient-specific benefits of proton therapy based upon geometric considerations. The model could also aid patient selection in model-based clinical trials or help justify clinical decisions to insurance companies. METHODS: The knowledge-based method trains a model upon existing proton treatment plans, exploiting correlations between dose and distance-to-target. Each OAR is split into concentric subvolumes surrounding the target volume, and a skew-normal PDF is fit to the dose distribution found within each shell...
June 2016: Medical Physics
C Williams, E Crowley, J Wolfgang
PURPOSE: Intraoperative electron radiotherapy (IORT) poses a unique set of challenges for treatment planning. Planning must be performed in a busy operating room environment over a short timeframe often with little advance knowledge of the treatment depth or applicator size. Furthermore, IORT accelerators can have a large number of possible applicators, requiring extensive databooks that must be searched for the appropriate dosimetric parameters. The goal of this work is to develop a software tool to assist in the planning process that is suited to the challenges faced in the IORT environment...
June 2016: Medical Physics
C Wu
PURPOSE: To implement an automatic electronic PDF plan reporting tool for Philips Pinnacle treatment planning system (TPS) METHODS: An electronic treatment plan reporting software is developed by us to enable fully automatic PDF report from Pinnacle TPS to external EMR programs such as MOSAIQ. The tool is named "plan2pdf". plan2pdf is implemented using Pinnacle scripts, Java and UNIX shell scripts, without any external program needed. plan2pdf supports full auto-mode and manual mode reporting...
June 2016: Medical Physics
J Steers, B Fraass
PURPOSE: To discuss several factors surrounding the decision on when to recalibrate the ArcCHECK device as well as present a simple and efficient monthly check to evaluate ArcCHECK calibrations. METHODS: ArcCheck (Sun Nuclear) calibrations were evaluated monthly by measuring a 25×25cm(2) field with 100 MU. Since ArcCHECK measurements are run on an almost nightly basis, such additional square field measurements are obtained with minimal additional effort. An in-house MATLAB script compares two radial (y-direction) profiles from the top/center of the new measurement relative to a baseline measurement acquired at the last device calibration...
June 2016: Medical Physics
H Nourzadeh, W Watkins, J Siebers, M Ahmad
PURPOSE: To determine if auto-contour and manual-contour-based plans differ when evaluated with respect to probabilistic coverage metrics and biological model endpoints for prostate IMRT. METHODS: Manual and auto-contours were created for 149 CT image sets acquired from 16 unique prostate patients. A single physician manually contoured all images. Auto-contouring was completed utilizing Pinnacle's Smart Probabilistic Image Contouring Engine (SPICE). For each CT, three different 78 Gy/39 fraction 7-beam IMRT plans are created; PD with drawn ROIs, PAS with auto-contoured ROIs, and PM with auto-contoured OARs with the manually drawn target...
June 2016: Medical Physics
J Zhou, X Ding, J Liang, J Zhang, Y Wang, D Yan
PURPOSE: With energy repainting in lung IMPT, the dose delivered is approximate to the convolution of dose in each phase with corresponding breathing PDF. This study is to compute breathing PDF weighted 4D dose in lung IMPT treatment and compare to its initial robust plan. METHODS: Six lung patients were evaluated in this study. Amsterdam shroud image were generated from pre-treatment 4D cone-beam projections. Diaphragm motion curve was extract from the shroud image and the breathing PDF was generated...
June 2016: Medical Physics
Y Zhou, J Tan, S Jiang, K Albuquerque, X Jia
PURPOSE: Plan specific quality assurance (QA) is an important step in high dose rate (HDR) brachytherapy to ensure the integrity of a treatment plan. The conventional approach is to assemble a set of plan screen-captures in a document and have an independent plan-checker to verify it. Not only is this approach cumbersome and time-consuming, using a document also limits the items that can be verified, hindering plan quality and patient safety. We have initiated efforts to develop a web-based HDR brachytherapy QA system called AutoBrachy QA, for comprehensive and efficient QA...
June 2016: Medical Physics
Masashi Mizuno, Yasuhiro Suzuki, Keiko Higashide, Yumi Sei, Daiki Iguchi, Fumiko Sakata, Masanobu Horie, Shoichi Maruyama, Seiichi Matsuo, B Paul Morgan, Yasuhiko Ito
BACKGROUND: We searched for indicators to predict the prognosis of infectious peritonitis by measuring levels of complement proteins and activation products in peritoneal dialysis (PD) fluid (PDF) of patients at early stages of peritonitis. We retrospectively analyzed the relationship between the levels of sC5b-9, C3 and C4 in PDF and the subsequent clinical prognosis. METHODS: We measured levels of sC5b-9, C3 and C4 in PDF on days 1, 2 and 5 post-onset of peritonitis in 104 episodes of infectious peritonitis in PD patients from 2008 and retrospectively compared levels with clinical outcomes...
2017: PloS One
Paulo F C Tilles, Sergei V Petrovskii, Paulo L Natti
Animals do not move all the time but alternate the period of actual movement (foraging) with periods of rest (e.g. eating or sleeping). Although the existence of rest times is widely acknowledged in the literature and has even become a focus of increased attention recently, the theoretical approaches to describe animal movement by calculating the dispersal kernel and/or the mean squared displacement (MSD) rarely take rests into account. In this study, we aim to bridge this gap. We consider a composite stochastic process where the periods of active dispersal or 'bouts' (described by a certain baseline probability density function (pdf) of animal dispersal) alternate with periods of immobility...
November 2016: Royal Society Open Science
Aneesh Manohar, Paolo Nason, Gavin P Salam, Giulia Zanderighi
It has become apparent in recent years that it is important, notably for a range of physics studies at the Large Hadron Collider, to have accurate knowledge on the distribution of photons in the proton. We show how the photon parton distribution function (PDF) can be determined in a model-independent manner, using electron-proton (ep) scattering data, in effect viewing the ep→e+X process as an electron scattering off the photon field of the proton. To this end, we consider an imaginary, beyond the Standard Model process with a flavor changing photon-lepton vertex...
December 9, 2016: Physical Review Letters
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