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Contrast dynamics

Wendy Ming, Dimitrios J Palidis, Miriam Spering, Martin J McKeown
Purpose: Visual impairments are frequent in Parkinson's disease (PD) and impact normal functioning in daily activities. Visual contrast sensitivity is a powerful nonmotor sign for discriminating PD patients from controls. However, it is usually assessed with static visual stimuli. Here we examined the interaction between perception and eye movements in static and dynamic contrast sensitivity tasks in a cohort of mildly impaired, early-stage PD patients. Methods: Patients (n = 13) and healthy age-matched controls (n = 12) viewed stimuli of various spatial frequencies (0-8 cyc/deg) and speeds (0°/s, 10°/s, 30°/s) on a computer monitor...
October 1, 2016: Investigative Ophthalmology & Visual Science
Jie Liang, Hsin-I Huang, Fernanda P Benzatti, Amelia B Karlsson, Junyi J Zhang, Nourhan Youssef, Averil Ma, Laura P Hale, Gianna E Hammer
Normal dynamics between microbiota and dendritic cells (DCs) support modest numbers of T cells, yet these do not cause inflammation. The DCs that induce inflammatory T cells and the signals that drive this process remain unclear. Here, we demonstrate that small intestine DCs lacking the signaling attenuator A20 induce inflammatory T cells and that the signals perceived and antigen-presenting cell (APC) functions are unique for different DC subsets. Thus, although CD103(+)CD11b(-) DCs exclusively instruct IFNγ(+) T cells, CD103(+)CD11b(+) DCs exclusively instruct IL-17(+) T cells...
October 25, 2016: Cell Reports
Kathia Sandoval, Yan Ding, Piero Gardinali
Comprehensive characterization of exposure media used in toxicology studies is still an area of significant divergence when evaluating potential oil spill impacts. When preparing exposure media used for toxicology testing, small variations in simple parameters such as mixing energy, oil type and loading can significantly affect the concentration of the oil components to which test organisms are exposed. The key goal of this study was compare and contrast the physical and chemical compositions of oil water mixtures prepared using fresh and weathered Macondo-related oils under different conditions of mixing and in the presence/absence of chemical dispersants...
October 23, 2016: Science of the Total Environment
Manoel Antonio Dos Santos, Maria Laura de Paula Lopes Pereira-Martins
The tasks of caregiving for children with disabilities involve contextual life stressors. The study aimed to investigate the coping strategies used by parents of children with intellectual disabilities (ID). The search included articles published between 2001 and 2015 on the PubMed, LILACS and PsycINFO databases, using the following key words: intellectual disability, coping, parents, caregivers, family. Thirteen articles were selected, the majority of which adopt a cross-sectional, comparative and quantitative approach...
October 2016: Ciência & Saúde Coletiva
Andrew B Rosenkrantz, James S Babb, Samir S Taneja, Justin M Ream
Purpose To test the impact of existing Prostate Imaging Reporting and Data System (PI-RADS) version 2 (V2) decision rules, as well as of proposed adjustments to these decision rules, on detection of Gleason score (GS) 7 or greater (GS ≥7) prostate cancer. Materials and Methods Two radiologists independently provided PI-RADS V2 scores for the dominant lesion on 343 prostate magnetic resonance (MR) examinations. Diagnostic performance for GS ≥7 tumor was assessed by using MR imaging-ultrasonography fusion-targeted biopsy as the reference...
October 26, 2016: Radiology
Jung Jae Park, Byung Kwan Park
PURPOSE: To evaluate the role of Prostate Imaging Reporting and Data System v. 2 (PI-RADSv2) in triaging patients with prostate cancer according to Prostate Cancer Research International: Active Surveillance (PRIAS). MATERIALS AND METHODS: Between January 2012 and December 2014, 456 patients with biopsy-proven cancer underwent multiparametric 3T magnetic resonance imaging (MRI) using T2 -weighted, diffusion-weighted, and dynamic contrast-enhanced MRI sequences, and then radical prostatectomy...
October 26, 2016: Journal of Magnetic Resonance Imaging: JMRI
Takayoshi Shinya, Ryota Inai, Takashi Tanaka, Noriaki Akagi, Shuhei Sato, Tadashi Yoshino, Susumu Kanazawa
PURPOSE: The purpose of the present study was to analyze the enhancement patterns of small bowel neoplasms on post-contrast multiphasic multidetector CT and to assess the diagnostic capacity for differentiating five tumor types. METHODS: We performed a retrospective study of data on 92 small bowel neoplasms. The neoplasms were categorized into five groups according to pathology findings, not imaging findings (23 adenocarcinomas; 22 lymphomas; 19 metastases; 18 gastrointestinal stromal tumors [GIST]; 10 neuroendocrine tumors [NET])...
October 25, 2016: Abdominal Radiology
Naomi Nitschke, Kalina Atkovska, Jochen S Hub
Molecular dynamics simulations are capable of predicting the permeability of lipid membranes for drug-like solutes, but the calculations have remained prohibitively expensive for high-throughput studies. Here, we analyze simple measures for accelerating potential of mean force (PMF) calculations of membrane permeation, namely, (i) using smaller simulation systems, (ii) simulating multiple solutes per system, and (iii) using shorter cutoffs for the Lennard-Jones interactions. We find that PMFs for membrane permeation are remarkably robust against alterations of such parameters, suggesting that accurate PMF calculations are possible at strongly reduced computational cost...
September 28, 2016: Journal of Chemical Physics
Antoine Carof, Mathieu Salanne, Thibault Charpentier, Benjamin Rotenberg
Using molecular simulations, we analyze the microscopic processes driving the Nuclear Magnetic Resonance (NMR) relaxation of quadrupolar cations in water. The fluctuations of the Electric Field Gradient (EFG) experienced by alkaline and magnesium cations, which determine the NMR relaxation time, are mainly due to the dynamics of water molecules in their solvation shell. The dynamics of the ion plays a less important role, with the exception of the short-time dynamics in the lighter Li(+) case, for which rattling in the solvent cage results in oscillations of the EFG autocorrelation function (ACF)...
September 28, 2016: Journal of Chemical Physics
Masato Hoshino, Kentaro Uesugi, Naoto Yagi
X-ray phase contrast tomography based on a grating interferometer was applied to fast and dynamic measurements of biological samples. To achieve this, the scanning procedure in the tomographic scan was improved. A triangle-shaped voltage signal from a waveform generator to a Piezo stage was used for the fast phase stepping in the grating interferometer. In addition, an optical fiber coupled x-ray scientific CMOS camera was used to achieve fast and highly efficient image acquisitions. These optimizations made it possible to perform an x-ray phase contrast tomographic measurement within an 8 min scan with density resolution of 2...
September 2016: Review of Scientific Instruments
Dario L Longo, Rachele Stefania, Chiara Callari, Francesco De Rose, Riccardo Rolle, Laura Conti, Lorena Consolino, Francesca Arena, Silvio Aime
A dynamic contrast enhanced (DCE) approach for tumor photoacoustic (PA) imaging is described. Novel water soluble melanin-based derivatives are synthesized that exhibit good PA properties, stability, safety and accumulation in tumor bearing mice. This melanin derivative is capable to characterize tumor vasculature and to monitor vessel permeability changes upon antiangiogenic treatment. DCE-PA imaging can assess functional response to cancer treatments.
October 26, 2016: Advanced Healthcare Materials
Jérôme F L Duval, Romain M Présent, Elise Rotureau
There is a large body of work evidencing the necessity to evaluate chemical speciation dynamics of trace metals in solution for an accurate definition of their bioavailability to microorganisms. In contrast, the integration of intracellular metal speciation dynamics in biouptake formalisms is still in its early stages. Accordingly, we elaborate here a rationale for the interplay between chemodynamics of intracellular metal complexes and dynamics of processes governing metal biouptake under non-complexing outer medium conditions...
October 26, 2016: Physical Chemistry Chemical Physics: PCCP
Esther A Kleibeuker, Emmanouil Fokas, Philip D Allen, Veerle Kersemans, Arjan W Griffioen, John Beech, Jaehong H Im, Sean C Smart, Kitty C Castricum, Jaap van den Berg, Iris A Schulkens, Sally A Hill, Adrian L Harris, Ben J Slotman, Henk M Verheul, Ruth J Muschel, Victor L Thijssen
The extent of tumor oxygenation is an important factor contributing to the efficacy of radiation therapy (RTx). Interestingly, several preclinical studies have shown benefit of combining RTx with drugs that inhibit tumor blood vessel growth, i.e. angiostatic therapy. Recent findings show that proper scheduling of both treatment modalities allows dose reduction of angiostatic drugs without affecting therapeutic efficacy. We found that whilst low dose sunitinib (20 mg/kg/day) did not affect the growth of xenograft HT29 colon carcinoma tumors in nude mice, the combination with either single dose RTx (1x 5Gy) or fractionated RTx (5x 2Gy/week, up to 3 weeks) substantially hampered tumor growth compared to either RTx treatment alone...
October 21, 2016: Oncotarget
Joohyun Kim, Tae Kim, Kwan Soo Hong, Hyeyoung Moon, In-Kyung Oh, Sang Mok Lee, Mark D Hohenwalter, Michael A Zimmerman, David C Cronin, Johnny C Hong
BACKGROUND: Gadoxetic acid is a liver-specific intravenous T1 magnetic resonance (MR) contrast agent that is excreted via the hepatobiliary system. We hypothesize that hepatocyte expressions of bile transporters (OATP1 and MRP2) correlate with dynamic profile of Gadoxetic acid enhanced (GE)-MR imaging (MRI). METHODS: Two groups of rats, control (n = 6) and cirrhosis (n = 12), received gadoxetic acid enhanced MRI followed by 70% hepatectomy. The change in MR signal intensity from the baseline before the contrast injection (ΔSI) was analyzed every minute for 30 min...
October 26, 2016: Journal of Investigative Surgery: the Official Journal of the Academy of Surgical Research
Malachi W Gillick-Healy, Elizabeth V Jennings, Helge Muller-Bunz, Yannick Ortin, Kirill Nikitin, Declan G Gilheany
The energy barriers in our recently discovered Walden inversion of chlorophosphonium salts are similar to those in Cope rearrangements of caged cyclic hydrocarbons. We have therefore designed a molecular system integrating the two processes, thereby producing the first embodiment in a chemical species of two entirely different and independent stereomutation mechanisms at the same nominal asymmetric centre. Thus, the energy barrier to the rearrangement of 9-phenyl-9-phosphabarbaralane oxide, easily prepared by a new high-yielding synthesis, was found to be ca...
October 25, 2016: Chemistry: a European Journal
Larry D Gruppen, R Brent Stansfield
PURPOSE: To examine, using a systems framework, the relative influence of individual-level and institution-level factors on student perceptions of the medical school educational environment. METHOD: A series of hierarchical linear models were fit to a large, 18-school longitudinal dataset of student perceptions of the educational environment, various demographics, and student empathy, tolerance of ambiguity, coping, and patient-provider orientation. Separate models were evaluated for individual-level factors alone, institution-level factors alone, and the combination of individual- and institution-level factors...
November 2016: Academic Medicine: Journal of the Association of American Medical Colleges
Zhi Zhu, Nan Sheng, Haiping Fang, Rongzheng Wan
Thermal noise is of fundamental importance to many processes. Traditionally, thermal noise has been treated as white noise on the macroscopic scale. Using molecular dynamics simulations and power spectrum analysis, we show that the thermal noise of solute molecules in water is non-white on the molecular scale, which is in contrast to the conventional theory. In the frequency domain from 2 × 10(11) Hz to 10(13) Hz, the power spectrum of thermal noise for polar solute molecules resembles the spectrum of 1/f noise...
October 25, 2016: Physical Chemistry Chemical Physics: PCCP
Yan Peng, Tilmann Bodenstein, Karin Fink, Valeriu Mereacre, Christopher E Anson, Annie K Powell
The single ion magnetic properties of Co(ii) are affected by the details of the coordination geometry of the ion. Here we show that a geometry close to trigonal prismatic which arises when the ligand 6,6'-((1Z)-((piperazine-1,4-diylbis(propane-3,1-diyl))bis(azanylylidene))bis(methanylylidene))bis(2-methoxyphenol) coordinates to Co(ii) does indeed lead to enhanced single-ion behaviour as has previously been predicted. Synthesis of the compound, structural information, and static as well as dynamic magnetic data are presented along with an analysis using quantum chemical ab initio calculations...
October 25, 2016: Physical Chemistry Chemical Physics: PCCP
Michael J Wade, Devin M Drown
We use population genetic models to investigate the cooperative and conflicting synergistic fitness effects between genes from the nucleus and the mitochondrion. By varying fitness parameters, we examine the scope for conflict relative to cooperation among genomes and the utility of the "gene's eye view" analytical approach, which is based on the marginal average fitness of specific alleles. Because sexual conflict can maintain polymorphism of mitochondrial haplotypes, we can explore two types of evolutionary conflict (genomic and sexual) with one epistatic model...
September 2016: Ecology and Evolution
Christoph Justen, Cornelia Herbert
So far, neurophysiological studies have investigated implicit and explicit self-related processing particularly for self-related stimuli such as the own face or name. The present study extends previous research to the implicit processing of self-related movement sounds and explores their spatio-temporal dynamics. Event-related potentials (ERPs) were assessed while participants (N = 12 healthy subjects) listened passively to previously recorded self- and other-related finger snapping sounds, presented either as deviants or standards during an oddball paradigm...
2016: Frontiers in Human Neuroscience
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