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Magnetization transfer

Mario Fleischer, Alexander Mainka, Steffen Kürbis, Peter Birkholz
Recently, 3D printing has been increasingly used to create physical models of the vocal tract with geometries obtained from magnetic resonance imaging. These printed models allow measuring the vocal tract transfer function, which is not reliably possible in vivo for the vocal tract of living humans. The transfer functions enable the detailed examination of the acoustic effects of specific articulatory strategies in speaking and singing, and the validation of acoustic plane-wave models for realistic vocal tract geometries in articulatory speech synthesis...
2018: PloS One
Jun-Hwan Park, Hoi-Seon Lee
The insecticidal toxicities of essential oils and other active components extracted from Eucalyptus dives leaves (as well as structural analogues) were studied against stored-product insects, Plodia interpunctella and Tribolium castaneum. 3-Carvomenthenone was purified from E. dives oil, and the structures were elucidated by electron ionization mass spectra,1 H-nuclear magnetic resonance (NMR),13 C-NMR, heteronuclear multiple quantum coherence,1 H-1 H correlation spectroscopy, and distortionless enhancement by polarization transfer NMR...
March 15, 2018: Journal of Food Protection
Yuly Vesga, Carlos Diaz, Jeanne Crassous, Florencio E Hernandez
Herein, we report on the theoretical-experimental analysis of the two photon absorption and circular dichroism spectra of 1-(2-pyridyl)-4-methoxy-carbo[6]helicene derivative (P6). The primary outcomes of our investigation on this particular helicene derivative with a donor-acceptor motif on one end led to two important conclusions: 1) The lengthening of the π-electron delocalization within the helical core of P6 predominantly increases the contribution of the magnetic transition dipole moment to the TPCD signal; 2) The electric transition quadrupole moment contribution to the TPCD signal is enhanced by the intramolecular charge transfer (ICT) produced by the donor-acceptor combination on one end of the molecule...
March 15, 2018: Journal of Physical Chemistry. A
Wei Du, Bilin Zhang, Pengqi Guo, Guoning Chen, Chun Chang, Qiang Fu
Dexamethasone-imprinted polymers were fabricated by reversible addition fragmentation chain transfer polymerization on the surface of magnetic nanoparticles under mild polymerization conditions, which exhibited a narrow polydispersity and high selectivity for dexamethasone extraction. The dexamethasone-imprinted polymers were characterized by scanning electron microscopy, transmission electron microscope, Fourier transform infrared spectroscopy, X-ray diffraction, energy dispersive spectrometry and vibrating sample magnetometry...
March 15, 2018: Journal of Separation Science
Kelvin J Yong, Tasneem M Vaid, Patrick J Shilling, Feng-Jie Wu, Lisa M Williams, Mattia Deluigi, Andreas Plückthun, Ross Ad Bathgate, Paul R Gooley, Daniel J Scott
α1A- and α1B-adrenoceptors (α1A-AR and α1B-AR) are closely related G protein-coupled receptors (GPCRs) that modulate the cardiovascular and nervous systems in response to binding epinephrine and norepinephrine. The GPCR gene super-family is made up of numerous sub-families that, like α1A-AR and α1B-AR, are activated by the same endogenous agonists but may modulate different physiological processes. A major challenge in GPCR research and drug discovery is determining how compounds interact with receptors at the molecular level, especially to assist in the optimization of drug leads...
March 14, 2018: ACS Chemical Biology
Francisco Pelaez, Navid Manuchehrabadi, Priyatanu Roy, Harishankar Natesan, Yiru Wang, Emilian Racila, Heather Fong, Kevin Zeng, Abby M Silbaugh, John C Bischof, Samira M Azarin
Currently, there are very few therapeutic options for treatment of metastatic disease, as it often remains undetected until the burden of disease is too high. Microporous poly(ε-caprolactone) biomaterials have been shown to attract metastasizing breast cancer cells in vivo early in tumor progression. In order to enhance the therapeutic potential of these scaffolds, they were modified such that infiltrating cells could be eliminated with non-invasive focal hyperthermia. Metal disks were incorporated into poly(ε-caprolactone) scaffolds to generate heat through electromagnetic induction by an oscillating magnetic field within a radiofrequency coil...
February 28, 2018: Biomaterials
Qingtian Zhang, K S Chan, Jingbo Li
We studied the spin-transfer torque (STT) in graphene based normal-metal/topological-insulator/ferromagnet heterostructures (N/TI/F), which is induced by the helical spin-polarized current in the quantum spin Hall insulator. We found that the STT is comparable in magnitude to the STT in ferromagnetic-normal- ferromagnetic graphene junction, while not requiring additional ferromagnetic layer with fixed magnetization, which makes it advantageous for the manipulation of magnetic devices in spintronics. More interestingly, the STT is very robust in our proposed nanostructure, as it is immune to changes in the geometry due to an asymmetrically notch or the presence of random nanopores in the quantum spin Hall insulator...
March 12, 2018: Scientific Reports
Linda I Suleiman, Kenneth A Weber, Brett D Rosenthal, Surabhi A Bhatt, Jason W Savage, Wellington K Hsu, Alpesh A Patel, Todd B Parrish
Magnetization transfer (MT) contrast has been established as a marker of myelin integrity, and cervical spondylotic myelopathy is known to cause demyelination. Ten patients with clinical and magnetic resonance imaging (MRI) manifestations of cervical spondylotic myelopathy (CSM) were compared to the MRIs of seven historic healthy controls, using the magnetization transfer ratio (MTR) and Nurick scores as the primary metrics. Transverse slices through the intervertebral discs of the cervical spine were acquired using a gradient echo sequence (MEDIC) with and without an MT saturation pulse on a 3 Tesla Siemens Prisma scanner (TR = 300 ms, TEeff  = 17 ms, flip angle = 30°, in-plane resolution = 0...
March 9, 2018: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
Katherine E Manning, Roger Tait, John Suckling, Anthony J Holland
Prader-Willi syndrome (PWS) is a neurodevelopmental disorder of genomic imprinting, presenting with a characteristic overeating disorder, mild to moderate intellectual disability, and a variable range of social and behavioral difficulties. Consequently, widespread alterations in neural structure and developmental and maturational trajectory would be expected. To date, there have been few quantitative and systematic studies of brain morphology in PWS, although alterations of volume and of cortical organisation have been reported...
2018: NeuroImage: Clinical
J D Afroze, M J Abden, M A Islam
Hydroxyapatite-functionalized multi-walled carbon nanotube (HA-fMWCNT) magnetic nanocomposite was successfully prepared using a novel slurry-compounding method. The prepared HA-fMWCNT nanocomposite with the addition of small amount (0.5 wt%) of fMWCNT exhibited much greater improvement in mechanical properties due to strong interfacial adhesion between acid-treated MWCNTs fillers and HA matrix, thus efficient stress transfer to nanotubes from the matrix. The nanocomposite exhibited excellent haemocompatibility...
May 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Lei Zhao, Han Liu, Zhihong He, Shikui Dong
In this paper, an all-metal nanostructure is designed with a large frequency ratio (∼6) and a large bandwidth ratio (∼32), and consists of period slit-box cavities and nanodisk clusters. It is a nearly perfect absorber at 1.064 μm to achieve laser stealth, a frequency-selective emitter with low emissivity in wavelength ranges 3-5 and 8-14 μm to achieve infrared stealth, and also an emitter with near unity emissivity at 2.709 μm and 6.107 μm to compensate for the decrease of radiation heat transfer owing to the low emissivity...
March 10, 2018: Applied Optics
Chang Liu, Yunchen Yang, Yun Wu
Current cancer diagnostic methods are challenged by low sensitivity, high false positive rate, limited tumor information, uncomfortable or invasive procedures, and high cost. Liquid biopsy that analyzes circulating biomarkers in body fluids represents a promising solution to these challenges. Exosomes are one of the promising cancer biomarkers for liquid biopsy because they are cell-secreted, nano-sized, extracellular vesicles that stably exist in all types of body fluids. Exosomes transfer DNAs, RNAs, proteins, and lipids from parent cells to recipient cells for intercellular communication and play important roles in cancer initiation, progression, and metastasis...
March 8, 2018: AAPS Journal
Giuseppe Ferrauto, Enza Di Gregorio, Daniela Delli Castelli, Silvio Aime
PURPOSE: Magnetic resonance imaging has been used extensively to track in vivo implanted cells that have been previously labeled with relaxation enhancers. However, this approach is not suitable to track multiple cell populations, as it may lead to confounding results in case the contrast agent is released from the labeled cells. This paper demonstrates how the use of CEST agents can overcome these issues. After encapsulating paramagnetic lanthanide shift reagents, we may shift the absorption frequency of the intracellular water resonance (δIn ), thus generating frequency-encoding CEST responsive cells that can be visualized in the MR image by applying the proper RF irradiation...
March 7, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Mohammed A Albedah, Farshad Nejadsattari, Zbigniew M Stadnik, Yi Liu, Guanghan Cao
The results of ab-initio hyperfine-interaction parameters calculations, and of X-ray diffraction and <sup>57</sup>Fe and <sup>151</sup>Eu Mössbauer spectroscopy study of the new 35 K superconductor CsEuFe<sub>4</sub>As<sub>4</sub> are reported. The superconductor crystallizes in the tetragonal space group <i>P</i>4/<i>nmm</i> with the lattice parameters a = 3...
March 7, 2018: Journal of Physics. Condensed Matter: An Institute of Physics Journal
Hua-Shan Liu, Shih-Wei Chiang, Hsiao-Wen Chung, Ping-Huei Tsai, Fei-Ting Hsu, Nai-Yu Cho, Chao-Ying Wang, Ming-Chung Chou, Cheng-Yu Chen
BACKGROUND AND OBJECTIVE: To investigate the feasibility of histogram analysis of the T2*-based permeability parameter volume transfer constant (Ktrans ) for glioma grading and to explore the diagnostic performance of the histogram analysis of Ktrans and blood plasma volume (vp ). METHODS: We recruited 31 and 11 patients with high- and low-grade gliomas, respectively. The histogram parameters of Ktrans and vp , derived from the first-pass pharmacokinetic modeling based on the T2* dynamic susceptibility-weighted contrast-enhanced perfusion-weighted magnetic resonance imaging (T2* DSC-PW-MRI) from the entire tumor volume, were evaluated for differentiating glioma grades...
March 2018: Computer Methods and Programs in Biomedicine
Xuanqi Xiong, Zhengwei Zhou, Matteo Figini, Junjie Shangguan, Zhuoli Zhang, Wei Chen
Objective: To quantitatively evaluate lumbar disc degeneration with recently-developed quantitative magnetic resonance imaging (MRI) techniques. A series of MRI parameters, including T2*, T1rho relaxation time, apparent diffusion coefficient and gagCEST, were compared and correlated with the Pfirrmann semi-quantitative classification of lumbar intervertebral disc degeneration; the most accurate and relevant MRI parameters of lumbar disc degeneration were identified. Materials and Methods: Thirty-seven subjects (age range, 18-74 years) with non-specific low back pain (LBP) for more than 6 months were enrolled...
2018: American Journal of Translational Research
Ling Zhang, Kasper P Kepp, Jens Ulstrup, Jingdong Zhang
Metalloporphyrins are active sites in metalloproteins and synthetic catalysts. They have also been studied extensively by electrochemistry as well as being prominent targets in electrochemical scanning tunneling microscopy (STM). Previous studies of FePPIX adsorbed on graphite and alkylthiol modified Au electrodes showed a pair of reversible Fe(III/II)PPIX peaks at about -0.41 V (vs. NHE) at high solution pH. We recently used iron protoporphyrin IX (FeP-PIX) as an intercalating probe for long-range electrochemical electron transfer through a G-quadruplex oligonucleo-tide (DNAzyme); this study disclosed two, rather than a single pair of voltammetric peaks with a new and dominating peak, shifted 200 mV positive relative to the  -0...
March 6, 2018: Langmuir: the ACS Journal of Surfaces and Colloids
Hao Liu, Moxiao Li, Yuhui Li, Hui Yang, Ang Li, Tian Jian Lu, Fei Li, Feng Xu
Gallium-based liquid metal has captivated exceptionally keen interest in recent years since it remains in the liquid phase at room temperature and thus conforms to the surrounding medium. Meanwhile, such morphing capability can be tuned via altering the oxide layer on the surface of the liquid metal, which further triggers enthusiasm for investigating its locomotion. In this study, we proposed a magnetic actuation scenario for steering liquid metal locomotion in an easily accessible and highly directed manner...
March 6, 2018: Soft Matter
Sangeeta Ray Banerjee, Xiaolei Song, Xing Yang, Il Minn, Ala Lisok, Yanrong Chen, Martin G Pomper, Peter C M van Zijl, Michael McMahon, Jian Chen
Chemical exchange saturation transfer (CEST) magnetic resonance imaging (MRI) is an innovative molecular imaging technique in which contrast agents are labeled by saturating their exchangeable protons spins by radio frequency irradiation. Salicylic acid and its analogues are a promising class of highly sensitive, diamagnetic CEST agents. We synthesized polymeric agents grafted with salicylic acid moieties and a known high-affinity ligand targeting prostate-specific membrane antigen (PSMA) in a ~10:1 molar ratio to provide sufficient MRI sensitivity and receptor specificity...
March 5, 2018: Chemistry: a European Journal
William J Allen, Refaat E Gabr, Getaneh B Tefera, Amol S Pednekar, Matthew W Vaughn, Ponnada A Narayana
Biomedical data are quickly growing in volume and in variety, providing clinicians an opportunity for better clinical decision support. Here, we demonstrate a robust platform that uses software automation and high performance computing (HPC) resources to achieve real-time analytics of clinical data, specifically magnetic resonance imaging (MRI) data. We used the Agave application programming interface to facilitate communication, data transfer, and job control between an MRI scanner and an off-site HPC resource...
March 2018: IEEE Journal of Biomedical and Health Informatics
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