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https://www.readbyqxmd.com/read/28436140/high-pressure-synthesis-of-fully-occupied-tetragonal-and-cubic-tungsten-bronze-oxides
#1
Yuya Ikeuchi, Hiroshi Takatsu, Cédric Tassel, Yoshihiro Goto, Taito Murakami, Hiroshi Kageyama
A high-pressure reaction yielded the fully occupied tetragonal tungsten bronze K3 W5 O15 (K0.6 WO3 ). The terminal phase shows an unusual transport property featuring slightly negative temperature-dependence in resistivity (dρ/dT<0) and a large Wilson ratio of RW =3.2. Such anomalous metallic behavior possibly arises from the low-dimensional electronic structure with a van Hove singularity at the Fermi level and/or from enhanced magnetic fluctuations by geometrical frustration of the tungsten sublattice...
April 24, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28435102/simultaneous-time-interleaved-multislice-stims-for-rapid-susceptibility-weighted-acquisition
#2
Berkin Bilgic, Huihui Ye, Lawrence L Wald, Kawin Setsompop
T2⁎ weighted 3D Gradient Echo (GRE) acquisition is the main sequence used for Susceptibility Weighted Imaging (SWI) and Quantitative Susceptibility Mapping (QSM). These applications require a long echo time (TE) to build up phase contrast, requiring a long repetition time (TR), and leading to excessively lengthy scans. The long TE acquisition creates a significant amount of unused time within each TR, which can be utilized for either multi-echo sampling or additional image encoding with the echo-shift technique...
April 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28434822/current-and-potential-imaging-applications-of-ferumoxytol-for-magnetic-resonance-imaging
#3
REVIEW
Gerda B Toth, Csanad G Varallyay, Andrea Horvath, Mustafa R Bashir, Peter L Choyke, Heike E Daldrup-Link, Edit Dosa, John Paul Finn, Seymur Gahramanov, Mukesh Harisinghani, Iain Macdougall, Alexander Neuwelt, Shreyas S Vasanawala, Prakash Ambady, Ramon Barajas, Justin S Cetas, Jeremy Ciporen, Thomas J DeLoughery, Nancy D Doolittle, Rongwei Fu, John Grinstead, Alexander R Guimaraes, Bronwyn E Hamilton, Xin Li, Heather L McConnell, Leslie L Muldoon, Gary Nesbit, Joao P Netto, David Petterson, William D Rooney, Daniel Schwartz, Laszlo Szidonya, Edward A Neuwelt
Contrast-enhanced magnetic resonance imaging is a commonly used diagnostic tool. Compared with standard gadolinium-based contrast agents, ferumoxytol (Feraheme, AMAG Pharmaceuticals, Waltham, MA), used as an alternative contrast medium, is feasible in patients with impaired renal function. Other attractive imaging features of i.v. ferumoxytol include a prolonged blood pool phase and delayed intracellular uptake. With its unique pharmacologic, metabolic, and imaging properties, ferumoxytol may play a crucial role in future magnetic resonance imaging of the central nervous system, various organs outside the central nervous system, and the cardiovascular system...
April 14, 2017: Kidney International
https://www.readbyqxmd.com/read/28434125/kidney-morphological-parameters-measured-using-noncontrast-enhanced-steady-state-free-precession-mri-with-spatially-selective-inversion-recovery-pulse-correlate-with-egfr-in-patients-with-advanced-ckd
#4
Tadashi Otsuka, Yoshikatsu Kaneko, Yuya Sato, Ryohei Kaseda, Ryuji Aoyagi, Suguru Yamamoto, Shin Goto, Ichiei Narita
BACKGROUND: It is well known that atrophic renal changes are associated with chronic kidney disease (CKD) progression, but conventional diagnostic imaging methods such as noncontrast-enhanced computed tomography and magnetic resonance imaging (MRI) have been insufficient for precisely assessing kidney function because they cannot clearly distinguish between the medulla and cortex. Hence, here we used noncontrast-enhanced steady-state free precession (SSFP) MRI with a spatially selective inversion recovery (IR) pulse to improve visibility for renal corticomedullary differentiation and evaluated the association between morphological parameters and kidney function in patients with CKD...
April 22, 2017: Clinical and Experimental Nephrology
https://www.readbyqxmd.com/read/28433483/functional-image-guided-stereotactic-body-radiation-therapy-planning-for-patients-with-hepatocellular-carcinoma
#5
Uranchimeg Tsegmed, Tomoki Kimura, Takeo Nakashima, Yuko Nakamura, Toru Higaki, Nobuki Imano, Yoshiko Doi, Masahiro Kenjo, Shuichi Ozawa, Yuji Murakami, Kazuo Awai, Yasushi Nagata
The aim of the current planning study is to evaluate the ability of gadoxetate disodium-enhanced magnetic resonance imaging (EOB-MRI)-guided stereotactic body radiation therapy (SBRT) planning by using intensity-modulated radiation therapy (IMRT) techniques in sparing the functional liver tissues during SBRT for hepatocellular carcinoma. In this study, 20 patients with hepatocellular carcinoma were enrolled. Functional liver tissues were defined according to quantitative liver-spleen contrast ratios ≥ 1...
April 19, 2017: Medical Dosimetry: Official Journal of the American Association of Medical Dosimetrists
https://www.readbyqxmd.com/read/28431306/difference-optimization-automatic-correction-of-relative-frequency-and-phase-for-mean-non-edited-and-edited-gaba-1-h-mega-press-spectra
#6
Marianne Cleve, Martin Krämer, Alexander Gussew, Jürgen R Reichenbach
Phase and frequency corrections of magnetic resonance spectroscopic data are of major importance to obtain reliable and unambiguous metabolite estimates as validated in recent research for single-shot scans with the same spectral fingerprint. However, when using the J-difference editing technique (1)H MEGA-PRESS, misalignment between mean edited (ON‾) and non-edited (OFF‾) spectra that may remain even after correction of the corresponding individual single-shot scans results in subtraction artefacts compromising reliable GABA quantitation...
April 7, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28430860/increased-brainstem-perfusion-but-no-blood-brain-barrier-disruption-during-attacks-of-migraine-with-aura
#7
Anders Hougaard, Faisal M Amin, Casper E Christensen, Samaira Younis, Frauke Wolfram, Stig P Cramer, Henrik B W Larsson, Messoud Ashina
The migraine aura is characterized by transient focal cortical disturbances causing dramatic neurological symptoms that are usually followed by migraine headache. It is currently not understood how the aura symptoms are related to the headache phase of migraine. Animal studies suggest that cortical spreading depression, the likely mechanism of migraine aura, causes disruption of the blood-brain barrier and noxious stimulation of trigeminal afferents leading to activation of brainstem nuclei and triggering of migraine headache...
April 18, 2017: Brain: a Journal of Neurology
https://www.readbyqxmd.com/read/28429241/pharmacological-approaches-to-the-management-of-secondary-progressive-multiple-sclerosis
#8
REVIEW
A Nandoskar, J Raffel, A S Scalfari, T Friede, R S Nicholas
It is well recognised that the majority of the impact of multiple sclerosis (MS), both personal and societal, arises in the progressive phase where disability accumulates inexorably. As such, progressive MS (PMS) has been the target of pharmacological therapies for many years. However, there are no current licensed treatments for PMS. This stands in marked contrast to relapsing remitting MS (RRMS) where trials have resulted in numerous licensed therapies. PMS has proven to be a more difficult challenge compared to RRMS and this review focuses on secondary progressive MS (SPMS), where relapses occur before the onset of gradual, irreversible disability, and not primary progressive MS where disability accumulation occurs without prior relapses...
April 20, 2017: Drugs
https://www.readbyqxmd.com/read/28429021/preparation-and-characterization-of-metastable-trigonal-layered-msb2o6-phases-m-co-ni-cu-zn-and-mg-and-considerations-on-fesb2o6
#9
A Yu Nikulin, E A Zvereva, V B Nalbandyan, I L Shukaev, A I Kurbakov, M D Kuchugura, G V Raganyan, Yu V Popov, V D Ivanchenko, A N Vasiliev
MSb2O6 compounds (M = Mg, Co, Ni, Cu, Zn) are known in the tetragonal trirutile forms, slightly distorted monoclinically with M = Cu due to the Jahn-Teller effect. In this study, using a low-temperature exchange reaction between ilmenite-type NaSbO3 and molten MSO4-KCl (or MgCl2-KCl) mixtures, these five compositions were prepared for the first time as trigonal layered rosiaite (PbSb2O6)-type phases. Upon heating, they irreversibly transform to the known phases via amorphous intermediates, in contrast to previously studied isostructural MnSb2O6, where the stable phase is structurally related to the metastable phase...
April 21, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28428470/effects-of-valsalva-maneuver-by-different-breath-holding-techniques-to-detect-pulmonary-thromboembolism-in-a-contrast-enhanced-computed-tomography-examination
#10
Chiaki Suzuki, Kenji Fujisaki, Yuusuke Atsumi, Miki Takemura, Kouichi Mizuno, Takeki Nagamine, Tomoyasu Amano, Hideo Yamamoto, Mamoru Takahashi
The purpose of this study is to measure the hemodynamics on the effect of Valsalva maneuver aiming at pulmonary thromboembolism (PTE) using 2-dimensional (2D) phase contrast imaging of magnetic resonance image (MRI), Philips Ingenia 3.0-tesla (T). The maximal inspiration reduced the blood flow rate in various degrees at all measurement positions, superior vena cava (SVC), inferior vena cava (IVC), pulmonary artery (PA), ascending aorta (AA), and descending aorta (DA). This result suggests that the contrast effect in the PA might become weak during general PA phase to give a substantial influence of Valsalva maneuver in the condition after maximum inspiration...
2017: Nihon Hoshasen Gijutsu Gakkai Zasshi
https://www.readbyqxmd.com/read/28421174/utility-of-cardiovascular-magnetic-resonance-derived-wave-intensity-analysis-as-a-marker-of-ventricular-function-in-children-with-heart-failure-and-normal-ejection-fraction
#11
Hopewell N Ntsinjana, Robin Chung, Paolo Ciliberti, Vivek Muthurangu, Silvia Schievano, Jan Marek, Kim H Parker, Andrew M Taylor, Giovanni Biglino
OBJECTIVE: This study sought to explore the diagnostic insight of cardiovascular magnetic resonance (CMR)-derived wave intensity analysis to better study systolic dysfunction in young patients with chronic diastolic dysfunction and preserved ejection fraction (EF), comparing it against other echocardiographic and CMR parameters. BACKGROUND: Evaluating systolic and diastolic dysfunctions in children is challenging, and a gold standard method is currently lacking...
2017: Frontiers in Pediatrics
https://www.readbyqxmd.com/read/28419810/the-relationship-of-static-tibial-tubercle-trochlear-groove-measurement-and-dynamic-patellar-tracking
#12
Victor R Carlson, Frances T Sheehan, Aricia Shen, Lawrence Yao, Jennifer N Jackson, Barry P Boden
BACKGROUND: The tibial tubercle to trochlear groove (TT-TG) distance is used for screening patients with a variety of patellofemoral joint disorders to determine who may benefit from patellar medialization using a tibial tubercle osteotomy. Clinically, the TT-TG distance is predominately based on static imaging with the knee in full extension; however, the predictive ability of this measure for dynamic patellar tracking patterns is unknown. PURPOSE: To determine whether the static TT-TG distance can predict dynamic lateral displacement of the patella...
April 1, 2017: American Journal of Sports Medicine
https://www.readbyqxmd.com/read/28418512/a-method-for-in-vitro-tcpc-compliance-verification
#13
Mike Tree, Zhenglun Alan Wei, Brady Munz, Kevin Maher, Shriprasad Deshpande, Timothy Slesnick, Ajit Yoganathan
The Fontan procedure is a common palliative intervention for sufferers of single ventricle congenital heart defects that results in an anastomosis of the venous return to the pulmonary arteries called the total cavopulmonary connection (TCPC). Local TCPC and global Fontan circulation hemodynamics are studied with in vitro circulatory models because of hemodynamic ties to Fontan patient long-term complications. The majority of in vitro studies, to date, employ a rigid TCPC model. Recently, a few studies have incorporated flexible TCPC models, but provide no justification for the model material properties...
June 1, 2017: Journal of Biomechanical Engineering
https://www.readbyqxmd.com/read/28411307/ferumoxytol-is-not-retained-in-kidney-allografts-in-patients-undergoing-acute-rejection
#14
Maryam Aghighi, Laura Pisani, Ashok J Theruvath, Anne M Muehe, Jessica Donig, Ramsha Khan, Samantha J Holdsworth, Neeraja Kambham, Waldo Concepcion, Paul C Grimm, Heike E Daldrup-Link
PURPOSE: To evaluate whether ultrasmall superparamagnetic iron oxide nanoparticle (USPIO)-enhanced magnetic resonance imaging (MRI) can detect allograft rejection in pediatric kidney transplant patients. PROCEDURES: The USPIO ferumoxytol has a long blood half-life and is phagocytosed by macrophages. In an IRB-approved single-center prospective clinical trial, 26 pediatric patients and adolescents (age 10-26 years) with acute allograft rejection (n = 5), non-rejecting allografts (n = 13), and normal native kidneys (n = 8) underwent multi-echo T2* fast spoiled gradient-echo (FSPGR) MRI after intravenous injection (p...
April 14, 2017: Molecular Imaging and Biology: MIB: the Official Publication of the Academy of Molecular Imaging
https://www.readbyqxmd.com/read/28409735/quantitative-magnetic-resonance-angiography-as-a-potential-predictor-for-cerebral-hyperperfusion-syndrome-a-preliminary-study
#15
Lukas Andereggen, Sepideh Amin-Hanjani, Marwan El-Koussy, Rajeev K Verma, Kenya Yuki, Daniel Schoeni, Kety Hsieh, Jan Gralla, Gerhard Schroth, Juergen Beck, Andreas Raabe, Marcel Arnold, Michael Reinert, Robert H Andres
OBJECTIVE Cerebral hyperperfusion syndrome (CHS) is a rare but devastating complication of carotid endarterectomy (CEA). This study sought to determine whether quantitative hemodynamic assessment using MR angiography can stratify CHS risk. METHODS In this prospective trial, patients with internal carotid artery (ICA) stenosis were randomly selected for pre- and postoperative quantitative phase-contrast MR angiography (QMRA). Assessment was standardized according to a protocol and included Doppler/duplex sonography, MRI, and/or CT angiography and QMRA of the intra- and extracranial supplying arteries of the brain...
April 14, 2017: Journal of Neurosurgery
https://www.readbyqxmd.com/read/28409252/pediatric-brain-mri-part-2-advanced-techniques
#16
REVIEW
Mai-Lan Ho, Norbert G Campeau, Thang D Ngo, Unni K Udayasankar, Kirk M Welker
Pediatric neuroimaging is a complex and specialized field that uses magnetic resonance (MR) imaging as the workhorse for diagnosis. MR protocols should be tailored to the specific indication and reviewed by the supervising radiologist in real time. Targeted advanced imaging sequences can be added to provide information regarding tissue microstructure, perfusion, metabolism and function. In part 2 of this review, we highlight the utility of advanced imaging techniques for superior evaluation of pediatric neurologic disease...
May 2017: Pediatric Radiology
https://www.readbyqxmd.com/read/28408827/photothermal-modulated-drug-delivery-and-magnetic-relaxation-based-on-collagen-poly-%C3%AE-glutamic-acid-hydrogel
#17
Sun-Hee Cho, Ahreum Kim, Woojung Shin, Min Beom Heo, Hyun Jong Noh, Kwan Soo Hong, Jee-Hyun Cho, Yong Taik Lim
Injectable and stimuli-responsive hydrogels have attracted attention in molecular imaging and drug delivery because encapsulated diagnostic or therapeutic components in the hydrogel can be used to image or change the microenvironment of the injection site by controlling various stimuli such as enzymes, temperature, pH, and photonic energy. In this study, we developed a novel injectable and photoresponsive composite hydrogel composed of anticancer drugs, imaging contrast agents, bio-derived collagen, and multifaceted anionic polypeptide, poly (γ-glutamic acid) (γ-PGA)...
2017: International Journal of Nanomedicine
https://www.readbyqxmd.com/read/28394475/dynamical-entrainment-of-corticospinal-excitability-during-rhythmic-movement-observation-a-tms-study
#18
Manuel Varlet, Giacomo Novembre, Peter E Keller
Spontaneous modulations of corticospinal excitability during action observation have been interpreted as evidence for the activation of internal motor representations equivalent to the observed action. Alternatively or complementary to this perspective, growing evidence shows that motor activity during observation of rhythmic movements can be modulated by direct visuomotor couplings and dynamical entrainment. In-phase and anti-phase entrainment spontaneously occur, characterized by cyclic movements proceeding simultaneously in the same (in-phase) or opposite (anti-phase) direction...
April 10, 2017: European Journal of Neuroscience
https://www.readbyqxmd.com/read/28394298/design-and-experimental-study-of-a-current-transformer-with-a-stacked-pcb-based-on-b-dot
#19
Jingang Wang, Diancheng Si, Tian Tian, Ran Ren
An electronic current transformer with a B-dot sensor is proposed in this study. The B-dot sensor can realize the current measurement of the transmission line in a non-contact way in accordance with the principle of magnetic field coupling. The multiple electrodes series-opposing structure is applied together with differential input structures and active integrating circuits, which can allow the sensor to operate in differential mode. Maxwell software is adopted to model and simulate the sensor. Optimization of the sensor structural parameters is conducted through finite-element simulation...
April 10, 2017: Sensors
https://www.readbyqxmd.com/read/28393638/vascular-territorial-segmentation-and-volumetric-blood-flow-measurement-using-dynamic-contrast-enhanced-magnetic-resonance-angiography-of-the-brain
#20
Oren Geri, Shelly I Shiran, Jonathan Roth, Moran Artzi, Liat Ben-Sira, Dafna Ben Bashat
This study proposes a method for territorial segmentation and volumetric flow rate (VFR) distribution measurement of cerebral territories based on time-resolved contrast enhanced magnetic-resonance-angiography (MRA). The method uses an iterative region-growing algorithm based on bolus-arrival-time with increased temporal resolution. Eight territories were segmented: (1) right and (2) left internal carotid arteries, including the middle cerebral artery (ICA+MCA), excluding the anterior cerebral arteries (ACA); (3) right and left ACA (R+L-ACA); (4) right and (5) left external carotid arteries (ECA); (6) right and (7) left posterior cerebral arteries (PCA); and (8) vertebrobasilar territory...
January 1, 2017: Journal of Cerebral Blood Flow and Metabolism
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