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https://www.readbyqxmd.com/read/27930940/comparative-sequence-analysis-of-enteroaggregative-escherichia-coli-heat-stable-enterotoxin-1-identified-in-korean-and-japanese-escherichia-coli-strains
#1
Dong Joo Seo, SunKeum Choi, Su Been Jeon, Suntak Jeong, Hyunkyung Park, Bog-Hieu Lee, Geun-Bae Kim, Soo-Jin Yang, Yoshikazu Nishikawa, Changsun Choi
The aim of this study was to compare the sequence of the astA gene found in 8 Korean and 11 Japanese Escherichia coli isolates. Conventional PCR was used to amplify the astA gene from the chromosomal and plasmid DNA preparation samples of each isolate using commercial DNA extraction kits. Cloning of the PCR products, sequence analysis, and pulse field gel electrophoresis (PFGE) were sequentially performed. An identical copy of astA in each isolate were found for 8 Korean and 8 Japanese E. coli strains isolated from bovine, porcine, and healthy human carriers...
November 21, 2016: International Journal of Food Microbiology
https://www.readbyqxmd.com/read/27928834/fast-fourier-based-simulation-of-off-resonance-artifacts-in-steady-state-gradient-echo-mri-applied-to-metal-object-localization
#2
Frank Zijlstra, Job G Bouwman, Ieva Braškutė, Max A Viergever, Peter R Seevinck
PURPOSE: To accelerate simulation of off-resonance artifacts in steady-state gradient echo MRI by using fast Fourier transforms and demonstrate its applicability to metal object localization. THEORY AND METHODS: By exploiting the repetitive nature of steady-state pulse sequences it is possible to use fast Fourier transforms to calculate the MR signal. Based on this principle, a method for fast simulation of off-resonance artifacts was designed. The method was validated against Bloch simulations and MRI scans...
December 7, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27924811/insights-into-the-evolution-of-pathogenicity-of-escherichia-coli-from-genomic-analysis-of-intestinal-e-coli-of-marmota-himalayana-in-qinghai-tibet-plateau-of-china
#3
Shan Lu, Dong Jin, Shusheng Wu, Jing Yang, Ruiting Lan, Xiangning Bai, Sha Liu, Qiong Meng, Xuejiao Yuan, Juan Zhou, Ji Pu, Qiang Chen, Hang Dai, Yuanyuan Hu, Yanwen Xiong, Changyun Ye, Jianguo Xu
Escherichia coli is both of a widespread harmless gut commensal and a versatile pathogen of humans. Domestic animals are a well-known reservoir for pathogenic E. coli. However, studies of E. coli populations from wild animals that have been separated from human activities had been very limited. Here we obtained 580 isolates from intestinal contents of 116 wild Marmot Marmota himalayana from Qinghai-Tibet plateau, China, with five isolates per animal. We selected 125 (hereinafter referred to as strains) from the 580 isolates for genome sequencing, based on unique pulse field gel electrophoresis patterns and at least one isolate per animal...
December 7, 2016: Emerging Microbes & Infections
https://www.readbyqxmd.com/read/27918030/solvation-behavior-of-carbonate-based-electrolytes-in-sodium-ion-batteries
#4
Arthur V Cresce, Selena M Russell, Oleg Borodin, Joshua A Allen, Marshall A Schroeder, Michael Dai, Jing Peng, Mallory P Gobet, Steven G Greenbaum, Reginald E Rogers, Kang Xu
Sodium ion batteries are on the cusp of being a commercially available technology. Compared to lithium ion batteries, sodium ion batteries can potentially offer an attractive dollar-per-kilowatt-hour value, though at the penalty of reduced energy density. As a materials system, sodium ion batteries present a unique opportunity to apply lessons learned in the study of electrolytes for lithium ion batteries; specifically, the behavior of the sodium ion in an organic carbonate solution and the relationship of ion solvation with electrode surface passivation...
December 5, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27918022/a-systematic-study-of-25-mg-nmr-in-paramagnetic-transition-metal-oxides-applications-to-mg-ion-battery-materials
#5
Jeongjae Lee, Ieuan D Seymour, Andrew J Pell, Siân E Dutton, Clare P Grey
Rechargeable battery systems based on Mg-ion chemistries are generating significant interest as potential alternatives to Li-ion batteries. Despite the wealth of local structural information that could potentially be gained from Nuclear Magnetic Resonance (NMR) experiments of Mg-ion battery materials, systematic (25)Mg solid-state NMR studies have been scarce due to the low natural abundance, low gyromagnetic ratio, and significant quadrupole moment of (25)Mg (I = 5/2). This work reports a combined experimental (25)Mg NMR and first principles density functional theory (DFT) study of paramagnetic Mg transition metal oxide systems Mg6MnO8 and MgCr2O4 that serve as model systems for Mg-ion battery cathode materials...
December 5, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27917527/simultaneous-orthogonal-plane-imaging
#6
Nikolai J Mickevicius, Eric S Paulson
PURPOSE: Intrafraction motion can result in a smearing of planned external beam radiation therapy dose distributions, resulting in an uncertainty in dose actually deposited in tissue. The purpose of this paper is to present a pulse sequence that is capable of imaging a moving target at a high frame rate in two orthogonal planes simultaneously for MR-guided radiotherapy. THEORY: By balancing the zero gradient moment on all axes, slices in two orthogonal planes may be spatially encoded simultaneously...
December 4, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/27916509/singlet-order-conversion-and-parahydrogen-induced-hyperpolarization-of-13-c-nuclei-in-near-equivalent-spin-systems
#7
James Eills, Gabriele Stevanato, Christian Bengs, Stefan Glöggler, Stuart J Elliott, Javier Alonso-Valdesueiro, Giuseppe Pileio, Malcolm H Levitt
We have demonstrated two radiofrequency pulse methods which convert the nuclear singlet order of proton spin pairs into the magnetisation of nearby (13)C nuclei. These irradiation schemes work well in the near-equivalence regime of the three-spin system, which applies when the difference in the two (1)H-(13)C couplings is much smaller than the (1)H-(1)H coupling. We use pulse sequences to generate thermally polarized singlet states in a reproducible manner, and study the singlet-to-magnetisation transfer step...
December 1, 2016: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/27915118/a-streamlined-acquisition-for-mapping-baseline-brain-oxygenation-using-quantitative-bold
#8
Alan J Stone, Nicholas P Blockley
Quantitative BOLD (qBOLD) is a non-invasive MR technique capable of producing quantitative measurements of the haemodynamic and metabolic properties of the brain. Here we propose a refinement of the qBOLD methodology, dubbed streamlined-qBOLD, in order to provide a clinically feasible method for mapping baseline brain oxygenation. In streamlined-qBOLD confounding signal contributions are minimised during data acquisition through the application of (i) a Fluid Attenuated Inversion Recovery (FLAIR) preparation to remove cerebral spinal fluid (CSF) signal contamination, (ii) a Gradient Echo Slice Excitation Profile Imaging (GESEPI) acquisition to reduce the effect of macroscopic magnetic field gradients and (iii) an Asymmetric Spin Echo (ASE) pulse sequence to directly measure the reversible transverse relaxation rate, R2'...
November 30, 2016: NeuroImage
https://www.readbyqxmd.com/read/27915087/genetically-unrelated-multidrug-and-carbapenem-resistant-citrobacter-freundii-detected-in-outpatients-admitted-to-a-portuguese-hospital
#9
Cátia Santos, Elmano Ramalheira, Gabriela Da Silva, Sónia Mendo
OBJECTIVES: Non-clonal, carbapenem- and multidrug-resistant Citrobacter freundii isolates were collected from unrelated outpatients admitted to a Portuguese hospital emergency department. One patient lived in a nursing home and was never hospitalised, whereas the other patient was repeatedly hospitalised in this hospital. The aim of this study was to unveil the molecular mechanisms associated with the carbapenem resistance of these isolates and to assess its potential dissemination. METHODS: Isolate identification was performed by VITEK(®)2 and was confirmed by 16S rDNA sequencing...
November 15, 2016: Journal of Global Antimicrobial Resistance
https://www.readbyqxmd.com/read/27910545/commercial-counterboard-for-10-ns-software-correlator-for-photon-and-fluorescence-correlation-spectroscopy
#10
Matteo Molteni, Fabio Ferri
A 10 ns time resolution, multi-tau software correlator, capable of computing simultaneous autocorrelation (A-A, B-B) and cross (A-B) correlation functions at count rates up to ∼10 MHz, with no data loss, has been developed in LabVIEW and C++ by using the National Instrument timer/counterboard (NI PCIe-6612) and a fast Personal Computer (PC) (Intel Core i7-4790 Processor 3.60 GHz ). The correlator works by using two algorithms: for large lag times (τ ≳ 1 μs), a classical time-mode scheme, based on the measure of the number of pulses per time interval, is used; differently, for τ ≲ 1 μs a photon-mode (PM) scheme is adopted and the correlation function is retrieved from the sequence of the photon arrival times...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27910536/experimental-study-on-the-fluorescence-spectrum-in-the-near-ultraviolet-and-visible-regions-of-a-carbon-dioxide-gas-cerenkov-medium
#11
Xingyin Guan, Huasi Hu, Zhaohui Song, Hetong Han
We investigated the faint fluorescence spectrum of carbon dioxide in the near-ultraviolet and visible regions using an intense relativistic electron beam accelerator with an energy of 0.2-0.3 MeV. Monte Carlo simulations were carried out in advance to maximize the signal-to-noise ratio and a self-normalization pulse experimental layout was designed to overcome the shot-to-shot fluctuations in different pulses of the accelerator. Ultimately, the relative proportion sequences in the near-ultraviolet and visible regions of a carbon dioxide fluorescence spectrum were successfully obtained for the first time...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27908188/polymer-gel-dosimetry-for-measuring-the-dose-near-thin-high-z-materials-irradiated-with-high-energy-photon-beams
#12
Leighton L Warmington, N Gopishankar, John H Broadhurst, Yoichi Watanabe
PURPOSE: To investigate the feasibility of three-dimensional (3D) dose measurements near thin high-Z materials placed in a water-like medium by using a polymer gel dosimeter (PGD) when the medium was irradiated with high energy photon beams. METHODS: PGD is potentially a useful tool for this application because it can record the dose around a small object made of a high-Z material in a continuous 3D medium. In this study, the authors manufactured a methacrylic acid-based normoxic PGD, nMAG...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27906347/versatile-spectral-modulation-of-a-broadband-source-for-digital-holographic-microscopy
#13
Gaël Nardin, Tristan Colomb, Yves Emery, Christophe Moser
We demonstrate the potential of spatial light modulators for the spectral control of a broadband source in digital holographic microscopy. Used in a 'pulse-shaping' geometry, the spatial light modulator provides a versatile control over the bandwidth and wavelength of the light source. The control of these properties enables adaptation to various experimental conditions. As a first application, we show that the source bandwidth can be adapted to the off-axis geometry to provide quantitative phase imaging over the whole field of view...
November 28, 2016: Optics Express
https://www.readbyqxmd.com/read/27904989/respirometric-response-and-microbial-succession-of-nitrifying-sludge-to-m-cresol-pulses-in-a-sequencing-batch-reactor
#14
Alberto Ordaz, Mariana Sánchez, Rodrigo Rivera, Rafael Rojas, Alejandro Zepeda
A nitrifying consortium was kinetically, stoichiometrically and molecularly characterized via the in situ pulse respirometric method and pyrosequencing analysis before and after the addition of m-cresol (25 mg C L(-1)) in a sequencing batch reactor (SBR). Five important kinetic and stoichiometric parameters were determined: the maximum oxygen uptake rate, the maximum nitrification rate, the oxidation yield, the biomass growth yield, and the substrate affinity constant. An inhibitory effect was observed in the nitrification process with a recovery of this by up to eight SBR cycles after m-cresol was added to the system...
November 30, 2016: Biodegradation
https://www.readbyqxmd.com/read/27903921/a-two-pool-model-to-describe-the-ivim-cerebral-perfusion
#15
Gabrielle Fournet, Jing-Rebecca Li, Alex M Cerjanic, Bradley P Sutton, Luisa Ciobanu, Denis Le Bihan
IntraVoxel Incoherent Motion (IVIM) is a magnetic resonance imaging (MRI) technique capable of measuring perfusion-related parameters. In this manuscript, we show that the mono-exponential model commonly used to process IVIM data might be challenged, especially at short diffusion times. Eleven rat datasets were acquired at 7T using a diffusion-weighted pulsed gradient spin echo sequence with b-values ranging from 7 to 2500 s/mm(2) at three diffusion times. The IVIM signals, obtained by removing the diffusion component from the raw MR signal, were fitted to the standard mono-exponential model, a bi-exponential model and the Kennan model...
November 30, 2016: Journal of Cerebral Blood Flow and Metabolism
https://www.readbyqxmd.com/read/27900916/electrically-evoked-compound-action-potentials-are-different-depending-on-the-site-of-cochlear-stimulation
#16
Paul van de Heyning, Santiago L Arauz, Marcus Atlas, Wolf-Dieter Baumgartner, Marco Caversaccio, Ronel Chester-Browne, Patricia Estienne, Javier Gavilan, Benoit Godey, Wolfgang Gstöttner, Demin Han, Rudolph Hagen, Martin Kompis, Vlad Kuzovkov, Luis Lassaletta, Franc Lefevre, Yongxin Li, Joachim Müller, Lorne Parnes, Andrea Kleine Punte, Christopher Raine, Gunesh Rajan, Adriana Rivas, José Antonio Rivas, Nicola Royle, Georg Sprinzl, Kurt Stephan, Adam Walkowiak, Yuri Yanov, Kim Zimmermann, Patrick Zorowka, Henryk Skarzynski
One of the many parameters that can affect cochlear implant (CI) users' performance is the site of presentation of electrical stimulation, from the CI, to the auditory nerve. Evoked compound action potential (ECAP) measurements are commonly used to verify nerve function by stimulating one electrode contact in the cochlea and recording the resulting action potentials on the other contacts of the electrode array. The present study aimed to determine if the ECAP amplitude differs between the apical, middle, and basal region of the cochlea, if double peak potentials were more likely in the apex than the basal region of the cochlea, and if there were differences in the ECAP threshold and recovery function across the cochlea...
November 30, 2016: Cochlear Implants International
https://www.readbyqxmd.com/read/27900204/preoperative-mr-staging-of-cervical-carcinoma-are-oblique-and-contrast-enhanced-sequences-necessary
#17
Susanne Fridsten, Ann-Cathrin Hellström, Kristina Hellman, Anders Sundin, Boel Söderén, Lennart Blomqvist
BACKGROUND: As the choice of treatment in patients with cervical carcinoma depends on cancer stage at diagnosis, accurate staging is essential. PURPOSE: To compare three different combinations of magnetic resonance (MR) sequences for preoperative staging. MATERIAL AND METHODS: Fifty-seven consecutive patients with biopsy proven cervical carcinoma underwent MR imaging (MRI) staging followed by primary surgical treatment. Thirty-two of 57 patients had had a cone biopsy prior to MRI...
November 2016: Acta Radiologica Open
https://www.readbyqxmd.com/read/27896396/metabolic-profiling-of-ob-ob-mouse-fatty-liver-using-hr-mas-1-h-nmr-combined-with-gene-expression-analysis-reveals-alterations-in-betaine-metabolism-and-the-transsulfuration-pathway
#18
Mikheil Gogiashvili, Karolina Edlund, Kathrin Gianmoena, Rosemarie Marchan, Alexander Brik, Jan T Andersson, Jörg Lambert, Katrin Madjar, Birte Hellwig, Jörg Rahnenführer, Jan G Hengstler, Roland Hergenröder, Cristina Cadenas
Metabolic perturbations resulting from excessive hepatic fat accumulation are poorly understood. Thus, in this study, leptin-deficient ob/ob mice, a mouse model of fatty liver disease, were used to investigate metabolic alterations in more detail. Metabolites were quantified in intact liver tissues of ob/ob (n = 8) and control (n = 8) mice using high-resolution magic angle spinning (HR-MAS) (1)H-NMR. In addition, after demonstrating that HR-MAS (1)H-NMR does not affect RNA integrity, transcriptional changes were measured by quantitative real-time PCR on RNA extracted from the same specimens after HR-MAS (1)H-NMR measurements...
November 28, 2016: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/27896179/clinical-factors-associated-with-the-non-operative-airway-management-of-patients-with-robin-sequence
#19
Frank P Albino, Benjamin C Wood, Kevin D Han, Sojung Yi, Mitchel Seruya, Gary F Rogers, Albert K Oh
BACKGROUND: The indications for surgical airway management in patients with Robin sequence (RS) and severe airway obstruction have not been well defined. While certain patients with RS clearly require surgical airway intervention and other patients just as clearly can be managed with conservative measures alone, a significant proportion of patients with RS present with a more confusing and ambiguous clinical course. The purpose of this study was to describe the clinical features and objective findings of patients with RS whose airways were successfully managed without surgical intervention...
November 2016: Archives of Plastic Surgery
https://www.readbyqxmd.com/read/27895872/investigation-of-factors-affecting-body-temperature-changes-during-routine-clinical-head-magnetic-resonance-imaging
#20
Myeong Seong Kim
BACKGROUND: Pulsed radiofrequency (RF) magnetic fields, required to produce magnetic resonance imaging (MRI) signals from tissue during the MRI procedure have been shown to heat tissues. OBJECTIVES: To investigate the relationship between body temperature rise and the RF power deposited during routine clinical MRI procedures, and to determine the correlation between this effect and the body's physiological response. PATIENTS AND METHODS: We investigated 69 patients from the Korean national cancer center to identify the main factors that contribute to an increase in body temperature (external factors and the body's response) during a clinical brain MRI...
October 2016: Iranian Journal of Radiology: a Quarterly Journal Published By the Iranian Radiological Society
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