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https://www.readbyqxmd.com/read/28102959/x-ray-scatter-correction-for-multi-source-interior-computed-tomography
#1
Hao Gong, Hao Yan, Xun Jia, Bin Li, Ge Wang, Guohua Cao
PURPOSE: The schemes of multi-source interior computed tomography (CT) have shown promise for ultra-fast, organ-oriented, and low-dose dynamic imaging. Besides forward scattering, x-ray cross scattering from multiple x-ray sources activated simultaneously can further degrade image quality. Here, we investigate the overall x-ray scattering artifact in a recently proposed multi-source interior CT architecture, and present two methods for scatter correction. METHODS: Compared to single-source global CT, scattering in multi-source interior CT architecture is affected by two new factors: cross scattering from simultaneously activated multiple x-ray sources and region-of-interest (ROI) oriented interior CT mode...
January 2017: Medical Physics
https://www.readbyqxmd.com/read/28102833/a-multimodal-approach-to-estimating-vigilance-using-eeg-and-forehead-eog
#2
Wei-Long Zheng, Baoliang Lu
OBJECTIVE: Covert aspects of ongoing user mental states provide key context information for user-aware human computer interactions. In this paper, we focus on the problem of estimating the vigilance of users using EEG and EOG signals. APPROACH: The PERCLOS index as vigilance annotation is obtained from eye tracking glasses. To improve the feasibility and wearability of vigilance estimation devices for real-world applications, we adopt a novel electrode placement for forehead EOG and extract various eye movement features, which contain the principal information of traditional EOG...
January 19, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28102310/coordinated-cell-motility-is-regulated-by-a-combination-of-lkb1-farnesylation-and-kinase-activity
#3
S Wilkinson, Y Hou, J T Zoine, J Saltz, C Zhang, Z Chen, L A D Cooper, A I Marcus
Cell motility requires the precise coordination of cell polarization, lamellipodia formation, adhesion, and force generation. LKB1 is a multi-functional serine/threonine kinase that associates with actin at the cellular leading edge of motile cells and suppresses FAK. We sought to understand how LKB1 coordinates these multiple events by systematically dissecting LKB1 protein domain function in combination with live cell imaging and computational approaches. We show that LKB1-actin colocalization is dependent upon LKB1 farnesylation leading to RhoA-ROCK-mediated stress fiber formation, but membrane dynamics is reliant on LKB1 kinase activity...
January 19, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28102029/biochemical-markers-to-predict-internal-browning-disorders-in-rocha-pear-during-storage-under-high-co2
#4
Teresa Deuchande, Christian Larrigaudière, Umbelina Guterres, Susana M P Carvalho, Marta W Vasconcelos
BACKGROUND: The aim of this study was to identify biochemical markers to predict internal browning disorders (IBD) in 'Rocha' pear. Fruit from five orchards were stored for 45 days under cold air followed by 100 days in browning inducing controlled atmosphere (CA) conditions (1 kPa O2 + 10 kPa CO2 ). RESULTS: Relationships between concentrations of ethanol (EtOH), acetaldehyde (AcDH), ascorbic acid (AA) and the activities of peroxidase (POX) and polyphenoloxidase (PPO) and IBD incidence were established...
January 19, 2017: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/28100829/a-mathematical-model-of-tumour-angiogenesis-growth-regression-and-regrowth
#5
Guillermo Vilanova, Ignasi Colominas, Hector Gomez
Cancerous tumours have the ability to recruit new blood vessels through a process called angiogenesis. By stimulating vascular growth, tumours get connected to the circulatory system, receive nutrients and open a way to colonize distant organs. Tumour-induced vascular networks become unstable in the absence of tumour angiogenic factors (TAFs). They may undergo alternating stages of growth, regression and regrowth. Following a phase-field methodology, we propose a model of tumour angiogenesis that reproduces the aforementioned features and highlights the importance of vascular regression and regrowth...
January 2017: Journal of the Royal Society, Interface
https://www.readbyqxmd.com/read/28100654/dissociation-between-sustained-single-neuron-spiking-%C3%AE-rhythmicity-and-transient-%C3%AE-lfp-oscillations-in-primate-motor-cortex
#6
Michael Everett Rule, Carlos E Vargas-Irwin, John P Donoghue, Wilson Truccolo
Determining the relationship between single-neuron spiking and transient (~20 Hz) beta local field potential (β-LFP) oscillations is an important step for understanding the role of these oscillations in motor cortex. We show that while motor cortex firing rates and beta spiking rhythmicity remain sustained during steady-state movement preparation periods, β-LFP oscillations emerge, in contrast, as short transient events. Single-neuron mean firing rates within and outside transient β-LFP events showed no differences, and no consistent correlation was found between the beta oscillations' amplitude and firing rates, as was the case for movement and visual-cue related β-LFP suppression...
January 18, 2017: Journal of Neurophysiology
https://www.readbyqxmd.com/read/28100610/the-measles-virus-receptor-slamf1-can-mediate-particle-endocytosis
#7
Daniel Gonçalves-Carneiro, Jane A McKeating, Dalan Bailey
: The signalling lymphocyte activation molecule F1 (SLAMF1) is both a microbial sensor and entry receptor for Measles virus (MeV). Herein, we describe a new role for SLAMF1 to mediate MeV endocytosis that is in contrast with the alternative, and generally accepted, model that MeV genome enters cells only after fusion at the cell surface. We demonstrated that MeV engagement of SLAMF1 induces dramatic but transient morphological changes, most prominently in the formation of membrane blebs, which were shown to co-localise with incoming viral particles, and rearrangement of the actin cytoskeleton in infected cells...
January 18, 2017: Journal of Virology
https://www.readbyqxmd.com/read/28100492/dynamic-assembly-of-ultrasoft-colloidal-networks-enables-cell-invasion-within-restrictive-fibrillar-polymers
#8
Alison M Douglas, Alexandros A Fragkopoulos, Michelle K Gaines, L Andrew Lyon, Alberto Fernandez-Nieves, Thomas H Barker
In regenerative medicine, natural protein-based polymers offer enhanced endogenous bioactivity and potential for seamless integration with tissue, yet form weak hydrogels that lack the physical robustness required for surgical manipulation, making them difficult to apply in practice. The use of higher concentrations of protein, exogenous cross-linkers, and blending synthetic polymers has all been applied to form more mechanically robust networks. Each relies on generating a smaller network mesh size, which increases the elastic modulus and robustness, but critically inhibits cell spreading and migration, hampering tissue regeneration...
January 18, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28100041/contrasting-growth-forecasts-across-the-geographical-range-of-scots-pine-due-to-altitudinal-and-latitudinal-differences-in-climatic-sensitivity
#9
Luis Matías, Juan C Linares, Ángela Sánchez-Miranda, Alistair S Jump
Ongoing changes in global climate are altering ecological conditions for many species. The consequences of such changes are typically most evident at the edge of a species' geographical distribution, where differences in growth or population dynamics may result in range expansions or contractions. Understanding population responses to different climatic drivers along wide latitudinal and altitudinal gradients is necessary in order to gain a better understanding of plant responses to ongoing increases in global temperature and drought severity...
January 18, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28100029/isolation-with-asymmetric-gene-flow-during-the-nonsynchronous-divergence-of-dry-forest-birds
#10
Jessica A Oswald, Isaac Overcast, William M Mauck, Michael J Andersen, Brian Tilston Smith
Dry forest bird communities in South America are often fragmented by intervening mountains and rainforests, generating high local endemism. The historical assembly of communities often results from dynamic processes linked to numerous population histories among co-distributed species. Nevertheless, species may diversify in the same way through time if landscape and environmental features, or species ecologies, similarly structure populations. Here we tested whether six co-distributed taxon pairs that occur in the dry forests of the Tumbes and Marañón Valley of northwestern South America show concordant patterns and modes of diversification...
January 18, 2017: Molecular Ecology
https://www.readbyqxmd.com/read/28099162/thermography-based-blood-flow-imaging-in-human-skin-of-the-hands-and-feet-a-spectral-filtering-approach
#11
A A Sagaidachnyi, A V Fomin, D A Usanov, A V Skripal
The determination of the relationship between skin blood flow and skin temperature dynamics is the main problem in thermography-based blood flow imaging. Oscillations in skin blood flow are the source of thermal waves propagating from micro-vessels toward the skin's surface, as assumed in this study. This hypothesis allows us to use equations for the attenuation and dispersion of thermal waves for converting the temperature signal into the blood flow signal, and vice versa. We developed a spectral filtering approach (SFA), which is a new technique for thermography-based blood flow imaging...
January 18, 2017: Physiological Measurement
https://www.readbyqxmd.com/read/28099108/integration-of-contrast-enhanced-us-into-a-multimodality-approach-to-imaging-of-nodules-in-a-cirrhotic-liver-how-i-do-it
#12
Patricia C Jo, Hyun-Jung Jang, Peter N Burns, Kelly W Burak, Tae Kyoung Kim, Stephanie R Wilson
Accurate characterization of cirrhotic nodules and early diagnosis of hepatocellular carcinoma (HCC) are of vital importance. Currently, computed tomography (CT) and magnetic resonance (MR) imaging are standard modalities for the investigation of new nodules found at surveillance ultrasonography (US). This article describes the successful integration of contrast material-enhanced US into a multimodality approach for diagnosis of HCC and its benefits in this population. The application of contrast-enhanced US immediately following surveillance US allows for prompt dynamic contrast-enhanced evaluation, removing the need for further imaging of benign lesions...
February 2017: Radiology
https://www.readbyqxmd.com/read/28099013/dynamic-nuclear-polarization-signal-enhancement-with-high-affinity-biradical-tags
#13
Rivkah Tamar Rogawski, Ivan V Sergeyev, Yongjun Li, Maria Francesca Ottaviani, Virginia W Cornish, Ann E McDermott
Dynamic nuclear polarization is an emerging technique for sensitizing solid state NMR experiments by transferring polarization from electrons to nuclei. Stable biradicals, the polarization source for the cross effect mechanism, are typically co-dissolved at millimolar concentrations with proteins of interest. Here we describe the high-affinity biradical tag TMP-T, created by covalently linking trimethoprim, a nanomolar affinity ligand of dihydrofolate reductase (DHFR), to the biradical polarizing agent TOTAPOL...
January 18, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28098754/drp1-dependent-mitochondrial-fission-plays-critical-roles-in-physiological-and-pathological-progresses-in-mammals
#14
REVIEW
Chenxia Hu, Yong Huang, Lanjuan Li
Current research has demonstrated that mitochondrial morphology, distribution, and function are maintained by the balanced regulation of mitochondrial fission and fusion, and perturbation of the homeostasis between these processes has been related to cell or organ dysfunction and abnormal mitochondrial redistribution. Abnormal mitochondrial fusion induces the fragmentation of mitochondria from a tubular morphology into pieces; in contrast, perturbed mitochondrial fission results in the fusion of adjacent mitochondria...
January 13, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28098022/system-dynamics-research-of-remanufacturing-closed-loop-supply-chain-dominated-by-the-third-party
#15
Shidi Miao, Tengfei Wang, Deyun Chen
With the rapid development of the electronic information industry in recent years, electronic products are being updated faster and faster, and e-waste recycling has become a common problem around the world. Firstly, this article contrasts recycling at home and abroad using the predicament of Midea Corp. Based on a closed-loop supply chain with the system dynamics method, a model is constructed and simulated. In this model, the collection point coverage rate is introduced to adjust the e-waste recycling rate dynamically...
January 1, 2017: Waste Management & Research
https://www.readbyqxmd.com/read/28097900/structure-activity-relationships-of-fraxamoside-as-an-unusual-xanthine-oxidase-inhibitor
#16
Rosa Maria Vitale, Lina Antenucci, Margherita Gavagnin, Gennaro Raimo, Pietro Amodeo
Fraxamoside, a macrocyclic secoiridoid glucoside featuring a hydroxytyrosol group, was recently identified as a xanthine oxidase inhibitor (XOI) comparable in potency in vitro to the standard antigout drug allopurinol. However, this activity and its considerably higher value than its derivatives oleuropein, oleoside 11-methyl ester, and hydroxytyrosol are not explained by structure-activity relationships (SARs) of known XOIs. To exclude allosteric mechanisms, we first determined the inhibition kinetic of fraxamoside...
December 2017: Journal of Enzyme Inhibition and Medicinal Chemistry
https://www.readbyqxmd.com/read/28096523/x-ray-imaging-of-spin-currents-and-magnetisation-dynamics-at-the-nanoscale
#17
Stefano Bonetti
Understanding how spins move in time and space is the aim of both fundamental and applied research in modern magnetism. Over the past three decades, research in this field has led to technological advances that have had a major impact on our society, while improving the understanding of the fundamentals of spin physics. However, important questions still remain unanswered, because it is experimentally challenging to directly observe spins and their motion with a combined high spatial and temporal resolution...
January 18, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
https://www.readbyqxmd.com/read/28094942/simulation-of-dbs-dbs-cooh-and-dbs-conhnh2-as-hydrogelators
#18
Dafna Knani, David Alperstein
The organic gelator 1,3(R):2,4(S)-dibenzylidene-D-sorbitol (DBS) self-organizes to form a 3-D network at relatively low concentrations in a variety of nonpolar organic solvents and polymer melt. DBS could be transformed into a hydrogelator by introduction of hydrophilic groups, which facilitate its self-assembly in aqueous medium. In this work, we have investigated the hydrogelators DBS-COOH and DBS-CONHNH2 and the organogelator DBS by molecular modeling. We have used quantum mechanics (QM) to elucidate the preferred geometry of one molecule and a dimer of each of the gelators, and molecular dynamics (MD) to simulate the pure gelators and their mixtures with water...
January 17, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28094764/neuromorphic-meets-neuromechanics-part-ii-the-role-of-fusimotor-drive
#19
Kian Jalaleddini, Chuanxin Niu, Suraj Chakravarthi Raja, Won Joon Sohn, Gerald Loeb, Terence Sanger, Francisco Valero-Cuevas
OBJECTIVE: We studied the fundamentals of muscle afferentation by building a neuro-mechano-morphic system actuating a cadaveric finger. This system is a faithful implementation of the stretch reflex circuitry. It allowed the systematic exploration of the effects of different fusimotor drives to the muscle spindle on the closed-loop stretch reflex response. APPROACH: As in Part I of this work, sensory neurons conveyed proprioceptive information from muscle spindles (with static and dynamic fusimotor drive) to populations of ��-motor neurons (with recruitment and rate coding properties)...
January 17, 2017: Journal of Neural Engineering
https://www.readbyqxmd.com/read/28094488/effects-of-leg-contrast-strength-training-on-sprint-agility-and-repeated-change-of-direction-performance-in-male-soccer-players
#20
Mehréz Hammami, Yassine Negra, Roy J Shephard, Mohamed Souhaiel Chelly
BACKGROUND: Contrast training is popular technique among individuals who are involved in dynamic sports, having as its goal an increase in dynamic muscular performance. It is characterized by the use of high and low loads in the same strength training session. The present investigation aimed to determine the effects of adding 8--weeks of contrast strength training (CSTP) to regular soccer practice in U--17 male soccer players during the competitive season. We hypothesized that CSTP would enhance their performance...
January 17, 2017: Journal of Sports Medicine and Physical Fitness
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