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https://www.readbyqxmd.com/read/28508476/magnetic-resonance-electrical-properties-tomography-for-small-anomalies-using-boundary-conditions-a-simulation-study
#1
Joonsung Lee, Narae Choi, Jin Keun Seo, Dong-Hyun Kim
PURPOSE: Magnetic Resonance Electrical Property Tomography (MREPT) is an emerging imaging modality using measured B1 maps from Magnetic Resonance Imaging (MRI) to measure a distribution of electric conductivity and permittivity of the subject at the Larmor frequency. Conventional MREPT approachesat single transmit channel system using the Helmholtz equation rely on an assumption that conductivity and permittivity of the subject are locally homogeneous. For small tissue structures and tissue boundaries, in which the assumption of locally homogeneous conductivity and permittivity does not hold, the reconstructed conductivity values deviated from the actual values, so called "Boundary Artifacts"...
May 16, 2017: Medical Physics
https://www.readbyqxmd.com/read/28465440/high-density-lipoprotein-receptor-scarb1-is-required-for-carotenoid-coloration-in-birds
#2
Matthew B Toomey, Ricardo J Lopes, Pedro M Araújo, James D Johnson, Małgorzata A Gazda, Sandra Afonso, Paulo G Mota, Rebecca E Koch, Geoffrey E Hill, Joseph C Corbo, Miguel Carneiro
Yellow, orange, and red coloration is a fundamental aspect of avian diversity and serves as an important signal in mate choice and aggressive interactions. This coloration is often produced through the deposition of diet-derived carotenoid pigments, yet the mechanisms of carotenoid uptake and transport are not well-understood. The white recessive breed of the common canary (Serinus canaria), which carries an autosomal recessive mutation that renders its plumage pure white, provides a unique opportunity to investigate mechanisms of carotenoid coloration...
May 2, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28437453/three-dominant-awnless-genes-in-common-wheat-fine-mapping-interaction-and-contribution-to-diversity-in-awn-shape-and-length
#3
Motohiro Yoshioka, Julio C M Iehisa, Ryoko Ohno, Tatsuro Kimura, Hiroyuki Enoki, Satoru Nishimura, Shuhei Nasuda, Shigeo Takumi
The awn is a long needle-like structure formed at the tip of the lemma in the florets of some grass species. It plays a role in seed dispersal and protection against animals, and can contribute to the photosynthetic activity of spikes. Three main dominant inhibitors of awn development (Hd, B1 and B2) are known in hexaploid wheat, but the causal genes have not been cloned yet and a genetic association with awn length diversity has been found only for the B1 allele. To analyze the prevalence of these three awning inhibitors, we attempted to predict the genotypes of 189 hexaploid wheat varieties collected worldwide using markers tightly linked to these loci...
2017: PloS One
https://www.readbyqxmd.com/read/28431009/artefact-free-late-gadolinium-enhancement-imaging-in-patients-with-implanted-cardiac-devices-using-a-modified-broadband-sequence-current-strategies-and-results-from-a-real-world-patient-cohort
#4
Sebastian Hilbert, Alexander Weber, Kay Nehrke, Peter Börnert, Bernhard Schnackenburg, Sabrina Oebel, Ricardo Spampinato, Cathleen Rogge, Sergio Richter, Gerhard Hindricks, Ingo Paetsch, Cosima Jahnke
Aims: Cardiac magnetic resonance (CMR) imaging in patients with implanted cardiac devices is often limited by device-related imaging artefacts. Limitations can potentially be overcome by employing a broadband late gadolinium enhancement (LGE)-CMR imaging technique. The purpose of this study was to investigate the relationship between implanted cardiac devices and the optimal frequency offset on broadband LGE-CMR imaging to increase the artefact-free visibility of myocardial segments. Methods and results: A phantom study was performed to characterize magnetic field disturbances related to 15 different cardiac devices...
April 18, 2017: Europace: European Pacing, Arrhythmias, and Cardiac Electrophysiology
https://www.readbyqxmd.com/read/28424353/constrained-release-of-lamina-associated-enhancers-and-genes-from-the-nuclear-envelope-during-t-cell-activation-facilitates-their-association-in-chromosome-compartments
#5
Michael I Robson, Jose I de Las Heras, Rafal Czapiewski, Aishwarya Sivakumar, Alastair R W Kerr, Eric Schirmer
The 3D organization of the genome changes concomitantly with expression changes during hematopoiesis and immune activation. Studies have focused either on lamina-associated domains (LADs) or on topologically-associated domains (TADs), defined by preferential local chromatin interactions, and chromosome compartments, defined as higher-order interactions between TADs sharing functionally similar states. However, few studies have investigated how these affect one another. To address this, we mapped LADs using Lamin B1-DamID during Jurkat T-cell activation, finding significant genome re-organization at the nuclear periphery dominated by release of loci frequently important for T-cell function...
April 19, 2017: Genome Research
https://www.readbyqxmd.com/read/28409357/diffusion-weighted-mri-to-assess-response-to-chemoradiotherapy-in-rectal-cancer-main-interpretation-pitfalls-and-their-use-for-teaching
#6
Doenja M J Lambregts, Miriam M van Heeswijk, Andrea Delli Pizzi, Saskia G C van Elderen, Luisa Andrade, Nicky H G M Peters, Peter A M Kint, Margreet Osinga-de Jong, Shandra Bipat, Rik Ooms, Max J Lahaye, Monique Maas, Geerard L Beets, Frans C H Bakers, Regina G H Beets-Tan
OBJECTIVES: To establish the most common image interpretation pitfalls for non-expert readers using diffusion-weighted imaging (DWI) to assess response to chemoradiotherapy in patients with rectal cancer and to explore the use of these pitfalls in an expert teaching setting. METHODS: Two independent non-expert readers (R1 and R2) scored the restaging DW MRI scans (b1,000 DWI, in conjunction with ADC maps and T2-W MRI scans for anatomical reference) in 100 patients for the likelihood of a complete response versus residual tumour using a five-point confidence score...
April 13, 2017: European Radiology
https://www.readbyqxmd.com/read/28370494/tailored-spiral-in-out-spectral-spatial-water-suppression-pulses-for-magnetic-resonance-spectroscopic-imaging
#7
Jun Ma, Carrie Wismans, Zhipeng Cao, Dennis W J Klomp, Jannie P Wijnen, William A Grissom
PURPOSE: To develop short water suppression sequences for 7 T magnetic resonance spectroscopic imaging, with mitigation of subject-specific transmit RF field ( B1+) inhomogeneity. METHODS: Patient-tailored spiral in-out spectral-spatial saturation pulses were designed for a three-pulse WET water suppression sequence. The pulses' identical spatial subpulses were designed using patient-specific B1+ maps and a spiral in-out excitation k-space trajectory. The subpulse train was weighted by a spectral envelope that was root-flipped to minimize peak RF demand...
March 31, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28349596/b1-sensitivity-analysis-of-quantitative-magnetization-transfer-imaging
#8
Mathieu Boudreau, Nikola Stikov, G Bruce Pike
PURPOSE: To evaluate the sensitivity of quantitative magnetization transfer (qMT) fitted parameters to B1 inaccuracies, focusing on the difference between two categories of T1 mapping techniques: B1 -independent and B1 -dependent. METHODS: The B1 -sensitivity of qMT was investigated and compared using two T1 measurement methods: inversion recovery (IR) (B1 -independent) and variable flip angle (VFA), B1 -dependent). The study was separated into four stages: 1) numerical simulations, 2) sensitivity analysis of the Z-spectra, 3) healthy subjects at 3T, and 4) comparison using three different B1 imaging techniques...
March 27, 2017: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/28346710/the-arabidopsis-thiamin-deficient-mutant-pale-green1-lacks-thiamin-monophosphate-phosphatase-of-the-vitamin-b1-biosynthesis-pathway
#9
Wei-Yu Hsieh, Jo-Chien Liao, Hsin-Tzu Wang, Tzu-Huan Hung, Ching-Chih Tseng, Tsui-Yun Chung, Ming-Hsiun Hsieh
Thiamin diphosphate (TPP, vitamin B1) is an essential coenzyme present in all organisms. Animals obtain TPP from their diets, but plants synthesize TPP de novo. We isolated and characterized an Arabidopsis pale green1 (pale1) mutant that contained higher concentrations of thiamin monophosphate (TMP) and less thiamin and TPP than the wild type. Supplementation with thiamin, but not the thiazole and pyrimidine precursors, rescued the mutant phenotype, indicating that the pale1 mutant is a thiamin-deficient mutant...
March 27, 2017: Plant Journal: for Cell and Molecular Biology
https://www.readbyqxmd.com/read/28343894/-1-9-n%C3%AE-c-crourorb-a1-isolated-from-croton-urucurana-latex-induces-g2-m-cell-cycle-arrest-and-apoptosis-in-human-hepatocarcinoma-cells
#10
Priscila de Matos Cândido-Bacani, Frédéric Ezan, Patrícia de Oliveira Figueiredo, Maria de Fátima Cepa Matos, Fernanda Rodrigues Garcez, Walmir Silva Garcez, Georges Baffet
[1-9-NαC]-crourorb A1 is a cyclic peptide isolated from Croton urucurana Baillon latex, found in midwestern Brazil, that has been shown to exert cytotoxic effects against a panel of cancer cell lines. However, the underlying mechanisms responsible for the crourorb A1-induced cytotoxicity in cancer cells remain unknown. In this study, the effects of crourorb A1 on the viability, apoptosis, cell cycle and migration of Huh-7 (human hepatocarcinoma) cells were investigated. We evaluated the viability of Huh-7 cells treated with crourorb A1 in 2D and 3D collagen cultures and found that cells in 3D culture exhibited increased resistance to crourorb A1 compared to cells in 2D culture (IC50: 62μg/ml versus 35...
May 5, 2017: Toxicology Letters
https://www.readbyqxmd.com/read/28336427/high-resolution-anatomical-and-quantitative-mri-of-the-entire-human-occipital-lobe-ex-vivo-at-9-4t
#11
S Sengupta, F J Fritz, R L Harms, S Hildebrand, D H Y Tse, B A Poser, R Goebel, A Roebroeck
Several magnetic resonance imaging (MRI) contrasts are sensitive to myelin content in gray matter in vivo which has ignited ambitions of MRI-based in vivo cortical histology. Ultra-high field (UHF) MRI, at fields of 7T and beyond, is crucial to provide the resolution and contrast needed to sample contrasts over the depth of the cortex and get closer to layer resolved imaging. Ex vivo MRI of human post mortem samples is an important stepping stone to investigate MRI contrast in the cortex, validate it against histology techniques applied in situ to the same tissue, and investigate the resolutions needed to translate ex vivo findings to in vivo UHF MRI...
March 20, 2017: NeuroImage
https://www.readbyqxmd.com/read/28304246/a-mouse-model-for-human-unstable-hemoglobin-santa-ana
#12
Samantha I Miyashiro, Silvia M G Massironi, Claudia M C Mori, Carolina C Cruz, Mitika K Hagiwara, Paulo C Maiorka
In the present study, we described the phenotype, histologic morphology, and molecular etiology of a mouse model of unstable hemoglobin Santa Ana. Hematologic evaluation of anemic mice (Anem/+) discovered after N-ethyl-N-nitrosourea mutagenesis revealed moderate anemia with intense reticulocytosis and polychromasia, followed by anisocytosis, macrocytosis, hypochromia, and intraerythrocytic inclusion and Heinz bodies. The mice also demonstrated hemoglobinuria, bilirubinemia, and erythrocytic populations with differing resistance to osmotic lysis...
December 1, 2016: Comparative Medicine
https://www.readbyqxmd.com/read/28301086/b1-mapping-for-bias-correction-in-quantitative-t1-imaging-of-the-brain-at-3t-using-standard-pulse-sequences
#13
Mathieu Boudreau, Christine L Tardif, Nikola Stikov, John G Sled, Wayne Lee, G Bruce Pike
PURPOSE: B1 mapping is important for many quantitative imaging protocols, particularly those that include whole-brain T1 mapping using the variable flip angle (VFA) technique. However, B1 mapping sequences are not typically available on many magnetic resonance imaging (MRI) scanners. The aim of this work was to demonstrate that B1 mapping implemented using standard scanner product pulse sequences can produce B1 (and VFA T1 ) maps comparable in quality and acquisition time to advanced techniques...
March 16, 2017: Journal of Magnetic Resonance Imaging: JMRI
https://www.readbyqxmd.com/read/28224915/characterization-of-small-rna-populations-in-non-transgenic-and-aflatoxin-reducing-transformed-peanut
#14
Imana L Power, Phat M Dang, Victor S Sobolev, Valerie A Orner, Joseph L Powell, Marshall C Lamb, Renee S Arias
Aflatoxin contamination is a major constraint in food production worldwide. In peanut (Arachis hypogaea L.), these toxic and carcinogenic aflatoxins are mainly produced by Aspergillus flavus Link and A. parasiticus Speare. The use of RNA interference (RNAi) is a promising method to reduce or prevent the accumulation of aflatoxin in peanut seed. In this study, we performed high-throughput sequencing of small RNA populations in a control line and in two transformed peanut lines that expressed an inverted repeat targeting five genes involved in the aflatoxin-biosynthesis pathway and that showed up to 100% less aflatoxin B1 than the controls...
April 2017: Plant Science: An International Journal of Experimental Plant Biology
https://www.readbyqxmd.com/read/28196133/b1-insensitive-t2-mapping-of-healthy-thigh-muscles-using-a-t2-prepared-3d-tse-sequence
#15
Elisabeth Klupp, Dominik Weidlich, Sarah Schlaeger, Thomas Baum, Barbara Cervantes, Marcus Deschauer, Hendrik Kooijman, Ernst J Rummeny, Claus Zimmer, Jan S Kirschke, Dimitrios C Karampinos
PURPOSE: To propose a T2-prepared 3D turbo spin echo (T2prep 3D TSE) sequence for B1-insensitive skeletal muscle T2 mapping and compare its performance with 2D and 3D multi-echo spin echo (MESE) for T2 mapping in thigh muscles of healthy subjects. METHODS: The performance of 2D MESE, 3D MESE and the proposed T2prep 3D TSE in the presence of transmit B1 and B0 inhomogeneities was first simulated. The thigh muscles of ten young and healthy subjects were then scanned on a 3 T system and T2 mapping was performed using the three sequences...
2017: PloS One
https://www.readbyqxmd.com/read/28167399/adapted-mr-velocimetry-of-slow-liquid-flow-in-porous-media
#16
Li Huang, Gerd Mikolajczyk, Ekkehard Küstermann, Michaela Wilhelm, Stefan Odenbach, Wolfgang Dreher
MR velocimetry of liquid flow in opaque porous filters may play an important role in better understanding the mechanisms of deep bed filtration. With this knowledge, the efficiency of separating the suspended solid particles from the vertically flowing liquid can be improved, and thus a wide range of industrial applications such as wastewater treatment and desalination can be optimized. However, MR velocimetry is challenging for such studies due to the low velocities, the severe B0 inhomogeneity in porous structures, and the demand for high spatial resolution and an appropriate total measurement time during which the particle deposition will change velocities only marginally...
January 27, 2017: Journal of Magnetic Resonance
https://www.readbyqxmd.com/read/28166977/caloric-restriction-and-igf-i-administration-promote-rabbit-fecundity-possible-interrelationships-and-mechanisms-of-action
#17
Alexander V Sirotkin, Iveta Koničková Florkovičová, Olga Østrup Švarcová, Jan Rafay, Jozef Laurincik, Abdel Halim Harrath
The aim of these in vivo and in vitro studies was to examine the influence of caloric restriction (CR), and the administration of insulin-like growth factor (IGF-I), on rabbit fecundity and to understand the interrelationships between CR and IGF-I, as well as the endocrine and intracellular mechanisms of their effects. Female rabbits were subjected to 50% CR, injections of IGF-I (20 μg/animal/day) and a combination of the two for 10 d before and 2 d after ovulation induced by 25 IU PMSG and 0.25 IU hCG...
March 1, 2017: Theriogenology
https://www.readbyqxmd.com/read/28163582/mapping-a-qtl-conferring-resistance-to-fusarium-head-blight-on-chromosome-1b-in-winter-wheat-triticum-aestivum-l
#18
Zenta Nishio, Chihiro Onoe, Miwako Ito, Tadashi Tabiki, Koichi Nagasawa, Hideho Miura
Fusarium head blight (FHB) is one of the most devastating diseases of wheat (Triticum aestivum L.), and the development of cultivars with FHB resistance is the most effective way to control the disease. Yumechikara is a Japanese hard red winter wheat cultivar that shows moderate resistance to FHB with superior bread-making quality. To identify quantitative trait loci (QTLs) for FHB resistance in Yumechikara, we evaluated doubled haploid lines derived from a cross between Yumechikara and a moderate susceptible cultivar, Kitahonami, for FHB resistance in a 5-year field trial, and we analyzed polymorphic molecular markers between the parents...
December 2016: Breeding Science
https://www.readbyqxmd.com/read/28158253/qtls-associated-with-agronomic-traits-in-the-attila-%C3%A3-cdc-go-spring-wheat-population-evaluated-under-conventional-management
#19
Jun Zou, Kassa Semagn, Muhammad Iqbal, Hua Chen, Mohammad Asif, Amidou N'Diaye, Alireza Navabi, Enid Perez-Lara, Curtis Pozniak, Rong-Cai Yang, Harpinder Randhawa, Dean Spaner
Recently, we investigated the effect of the wheat 90K single nucleotide polymorphic (SNP) array and three gene-specific (Ppd-D1, Vrn-A1 and Rht-B1) markers on quantitative trait loci (QTL) detection in a recombinant inbred lines (RILs) population derived from a cross between two spring wheat (Triticum aestivum L.) cultivars, 'Attila' and 'CDC Go', and evaluated for eight agronomic traits at three environments under organic management. The objectives of the present study were to investigate the effect of conventional management on QTL detection in the same mapping population using the same set of markers as the organic management and compare the results with organic management...
2017: PloS One
https://www.readbyqxmd.com/read/28113801/simultaneous-quantitative-imaging-of-electrical-properties-and-proton-density-from-b1-maps-using-mri
#20
Jiaen Liu, Pierre-Francois Van de Moortele, Xiaotong Zhang, Yicun Wang, Bin He
Electrical conductivity and permittivity of biological tissues are important diagnostic parameters and are useful for calculating subject-specific specific absorption rate distribution. On the other hand, water proton density also has clinical relevance for diagnosis purposes. These two kinds of tissue properties are inevitably associated in the technique of electrical properties tomography (EPT), which can be used to map in vivo electrical properties based on the measured B1 field distribution at Larmor frequency using magnetic resonance imaging (MRI)...
March 29, 2016: IEEE Transactions on Medical Imaging
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