Read by QxMD icon Read


Gil Farkash, Jean-Nicolas Dumez, Lucio Frydman
Enhancing the specificity of the spins' excitation can improve the capabilities of magnetic resonance. Exciting voxels with tailored 3D shapes reduces partial volume effects and enhances contrast, particularly in cases where cubic voxels or other simple geometries do not provide an optimal localization. Spatial excitation profiles of arbitrary shapes can be implemented using so-called multidimensional RF pulses, which are often limited in practice to 2D implementations owing to their sensitivity to field inhomogeneities...
September 6, 2016: Journal of Magnetic Resonance
Lin Chen, Jianpan Huang, Ting Zhang, Jing Li, Congbo Cai, Shuhui Cai
Spatiotemporally encoded (SPEN) single-shot MRI is an emerging ultrafast technique, which is capable of spatially selective acquisition and reduced field-of-view imaging. Compared to uniform sampling, variable density sampling has great potential in reducing aliasing artifacts and improving sampling efficiency. In this study, variable density spiral trajectory and non-Cartesian super-resolved (SR) reconstruction method are developed for SPEN MRI. The gradient waveforms design of spiral trajectory is mathematically described as an optimization problem subjected to the limitations of hardware...
August 28, 2016: Journal of Magnetic Resonance
Yinglu Zhang, Katarzyna Rataj, Gordon G Simpson, Liang Tong
The Arabidopsis protein FPA controls flowering time by regulating the alternative 3'-end processing of the FLOWERING LOCUS (FLC) antisense RNA. FPA belongs to the split ends (SPEN) family of proteins, which contain N-terminal RNA recognition motifs (RRMs) and a SPEN paralog and ortholog C-terminal (SPOC) domain. The SPOC domain is highly conserved among FPA homologs in plants, but the conservation with the domain in other SPEN proteins is much lower. We have determined the crystal structure of Arabidopsis thaliana FPA SPOC domain at 2...
2016: PloS One
Krinio Giannikou, Izabela A Malinowska, Trevor J Pugh, Rachel Yan, Yuen-Yi Tseng, Coyin Oh, Jaegil Kim, Magdalena E Tyburczy, Yvonne Chekaluk, Yang Liu, Nicola Alesi, Geraldine A Finlay, Chin-Lee Wu, Sabina Signoretti, Matthew Meyerson, Gad Getz, Jesse S Boehm, Elizabeth P Henske, David J Kwiatkowski
Renal angiomyolipoma is a kidney tumor in the perivascular epithelioid (PEComa) family that is common in patients with Tuberous Sclerosis Complex (TSC) and Lymphangioleiomyomatosis (LAM) but occurs rarely sporadically. Though histologically benign, renal angiomyolipoma can cause life-threatening hemorrhage and kidney failure. Both angiomyolipoma and LAM have mutations in TSC2 or TSC1. However, the frequency and contribution of other somatic events in tumor development is unknown. We performed whole exome sequencing in 32 resected tumor samples (n = 30 angiomyolipoma, n = 2 LAM) from 15 subjects, including three with TSC...
August 2016: PLoS Genetics
Ting Zhang, Lin Chen, Jianpan Huang, Jing Li, Shuhui Cai, Congbo Cai, Zhong Chen
As a recently emerging method, spatiotemporally encoded (SPEN) magnetic resonance imaging (MRI) has a high robustness to field inhomogeneity and chemical shift effect. It has been broadened from single-slice scanning to multi-slice scanning. In this paper, a novel multi-slice SPEN MRI method was proposed. In this method, the slice-selective dimension was segmented to lower the specific absorption rate (SAR) and improve the image quality. This segmented method, dubbed SeSPEN method, was theoretically analyzed and demonstrated with phantom, lemon and in vivo rat brain experiments...
August 2016: Journal of Magnetic Resonance
Yen-Sung Huang, Che-Chang Chang, Szu-Shuo Lee, Yuh-Shan Jou, Hsiu-Ming Shih
Long noncoding RNAs (lncRNAs) dysregulated in cancer potentially play oncogenic or tumor-suppressive roles. While the X inactivate-specific transcript (Xist) lncRNA is important for X-chromosome inactivation in female cells, very little is known about the role of Xist in human breast cancer in modulating cellular pathway(s). Here, we show that Xist expression is significantly reduced in breast tumor samples and cancer cell lines. Xist knockdown or overexpression resulted in increased or decreased levels, respectively, of AKT phosphorylation and cell viability...
May 27, 2016: Oncotarget
Gilad Liberman, Lucio Frydman
PURPOSE: Spatiotemporal encoding (SPEN) can deliver single-scan MR images without folding complications and with increased robustness to chemical shift and susceptibility artifacts. Yet, it does so at the expense of relatively high specific absorption rates (SAR) owing to its reliance on frequency-swept pulses. This study describes SPEN implementations aimed at full three-dimensional (3D) multislice imaging, possessing reduced SAR thanks to an implementation based on new 2D radiofrequency (RF) pulses...
May 20, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Zhipeng Lu, Qiangfeng Cliff Zhang, Byron Lee, Ryan A Flynn, Martin A Smith, James T Robinson, Chen Davidovich, Anne R Gooding, Karen J Goodrich, John S Mattick, Jill P Mesirov, Thomas R Cech, Howard Y Chang
RNA has the intrinsic property to base pair, forming complex structures fundamental to its diverse functions. Here, we develop PARIS, a method based on reversible psoralen crosslinking for global mapping of RNA duplexes with near base-pair resolution in living cells. PARIS analysis in three human and mouse cell types reveals frequent long-range structures, higher-order architectures, and RNA-RNA interactions in trans across the transcriptome. PARIS determines base-pairing interactions on an individual-molecule level, revealing pervasive alternative conformations...
May 19, 2016: Cell
Jianpan Huang, Miao Zhang, Jianhua Lu, Congbo Cai, Lin Chen, Shuhui Cai
PURPOSE: To design a new approach that can not only keep the spatial and temporal resolution but also have better built-in immunity to magnetic field inhomogeneity and chemical shift effects than the single-shot echo planar imaging (EPI) for chemical exchange saturation transfer (CEST) MRI. METHOD: The single-shot spatiotemporally encoded (SPEN) MRI sequence was combined with a continuous wave saturation pulse for fast CEST MRI (CEST-SPEN MRI). The resulting images were super-resolved reconstructed by a hybrid method that solves the l1 norm minimization together with total variation (TV) regularization...
April 27, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Hassan Mohammadi Abdar, Angela Ridgel, Fred Discenzo, Robert Phillips, Benjamin Walter, Kenneth Loparo
To assess and validate the Smart Exercise Bike designed for Parkinson's Disease (PD) rehabilitation, forty-seven individuals with PD were randomly assigned to either the static or dynamic cycling group, and completed three sessions of exercise. Heart rate, cadence and power data were captured and recorded for each patient during exercise. Motor function for each subject was assessed with the UPDRS Motor III test before and after the three exercise sessions to evaluate the effect of exercise on functional abilities...
March 31, 2016: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Pavan Ramkumar, Bruce C Hansen, Sebastian Pannasch, Lester C Loschky
Perceiving the visual world around us requires the brain to represent the features of stimuli and to categorize the stimulus based on these features. Incorrect categorization can result either from errors in visual representation or from errors in processes that lead to categorical choice. To understand the temporal relationship between the neural signatures of such systematic errors, we recorded whole-scalp magnetoencephalography (MEG) data from human subjects performing a rapid-scene categorization task. We built scene category decoders based on (1) spatiotemporally resolved neural activity, (2) spatial envelope (SpEn) image features, and (3) behavioral responses...
July 1, 2016: NeuroImage
Peter Tatham, Karen Spens, Gyöngyi Kovács
Although significant progress has been made in developing the practice of humanitarian logistics, further improvements in efficiency and effectiveness have the potential to save lives and reduce suffering. This paper explores how the military/emergency services' concept of a common operating picture (COP) can be adapted to the humanitarian logistics context, and analyses a practical and proven approach to addressing the key challenge of inter-agency coordination and decision-making. Successful adaptation could provide the mechanism through which predicted and actual demands, together with the location and status of material in transit, are captured, evaluated, and presented in real time as the basis for enhanced decision-making between actors in the humanitarian supply network...
March 14, 2016: Disasters
Eddy Solomon, Gilad Liberman, Noam Nissan, Lucio Frydman
PURPOSE: Evaluate the usefulness of single-shot and of interleaved spatiotemporally encoded (SPEN) methods to perform diffusion tensor imaging (DTI) under various preclinical and clinical settings. METHODS: A formalism for analyzing SPEN DTI data is presented, tailored to account for the spatially dependent b-matrix weightings introduced by the sequence's use of swept pulses acting while in the presence of field gradients. Using these b-matrix calculations, SPEN's ability to deliver DTI measurements was tested on phantoms as well as ex vivo and in vivo...
March 10, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Zhiyong Zhang, Amir Seginer, Lucio Frydman
PURPOSE: Single-scan two-dimensional MRI has been generally constrained to acquisitions in high quality magnets. This study introduces a methodology, cross-term spatiotemporal encoding (xSPEN), that delivers such images under much poorer external field conditions. METHODS: xSPEN departs from conventional k-space scanning, by relying on spatiotemporally encoding the image being sought. Unlike hitherto proposed SPEN methods, however, xSPEN's image readout does not take place using a field gradient along the direction being probed, but rather with the aid of an ancillary source of inhomogeneous frequency broadening...
February 22, 2016: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
Ute Goerke
PURPOSE: Ultrafast imaging techniques based on spatiotemporal encoding (SPEN), such as RASER (rapid acquisition with sequential excitation and refocusing), is a promising new class of sequences since they are largely insensitive to magnetic field variations which cause signal loss and geometric distortion in EPI. So far, attempts to theoretically describe the point-spread-function (PSF) for the original SPEN-imaging techniques have yielded limited success. To fill this gap a novel definition for an apparent PSF is proposed...
May 2016: Magnetic Resonance Imaging
Charny Park, Sang Yun Ha, Seung Tae Kim, Hee Cheol Kim, Jin Seok Heo, Young Suk Park, Gregory Lauwers, Jeeyun Lee, Kyoung-Mee Kim
Genomic profiles of gastroenteropancreatic neuroendocrine tumors (GEP-NETs) are still insufficiently understood, and the genetic alterations associated with drug responses have not been studied. Here, we performed whole exome sequencing of 12 GEP-NETs from patients enrolled in a nonrandomized, open-labeled, single-center phase II study for pazopanib, and integrated our results with previously published results on pancreas (n = 12) and small intestine NETs (n = 50). The mean numbers of somatic mutations in each case varied widely from 20 to 4682...
January 26, 2016: Oncotarget
Jon Arne Søreide, Ole Jakob Greve, Einar Gudlaugsson
BACKGROUND: Pancreatic tumors in pregnancy are rare but clinically challenging. Careful diagnostic workup, including appropriate imaging examinations, should be performed to evaluate surgery indications and timing . In the present case a diagnosis of an adult pancreatic hemangioma was made. We were not able to identify a similar case in the very sparse literature on this rare disease. CASE PRESENTATION: A 30-year-old woman at 12 weeks of gestation was diagnosed with a large pancreatic tumor having a cystic pattern based on imaging...
2015: BMC Surgery
Rita Schmidt, Mor Mishkovsky, Jean-Noel Hyacinthe, Nicolas Kunz, Rolf Gruetter, Arnaud Comment, Lucio Frydman
Given their high sensitivity and ability to limit the field of view (FOV), surface coils are often used in magnetic resonance spectroscopy (MRS) and imaging (MRI). A major downside of surface coils is their inherent radiofrequency (RF) B1 heterogeneity across the FOV, decreasing with increasing distance from the coil and giving rise to image distortions due to non-uniform spatial responses. A robust way to compensate for B1 inhomogeneities is to employ adiabatic inversion pulses, yet these are not well adapted to all imaging sequences - including to single-shot approaches like echo planar imaging (EPI)...
October 2015: Journal of Magnetic Resonance
Valerie K Jordan, Hitisha P Zaveri, Daryl A Scott
Deletions of chromosome 1p36 affect approximately 1 in 5,000 newborns and are the most common terminal deletions in humans. Medical problems commonly caused by terminal deletions of 1p36 include developmental delay, intellectual disability, seizures, vision problems, hearing loss, short stature, distinctive facial features, brain anomalies, orofacial clefting, congenital heart defects, cardiomyopathy, and renal anomalies. Although 1p36 deletion syndrome is considered clinically recognizable, there is significant phenotypic variation among affected individuals...
2015: Application of Clinical Genetics
Dong Yan, Norbert Perrimon
Sex-lethal (Sxl) encodes the master regulator of the sex determination pathway in Drosophila and acts by controlling sex identity in both soma and germ line. In females Sxl maintains its own expression by controlling the alternative splicing of its own mRNA. Here, we identify a novel sex determination gene, spenito (nito) that encodes a SPEN family protein. Loss of nito activity results in stem cell tumors in the female germ line as well as female-to-male somatic transformations. We show that Nito is a ubiquitous nuclear protein that controls the alternative splicing of the Sxl mRNA by interacting with Sxl protein and pre-mRNA, suggesting that it is directly involved in Sxl auto-regulation...
September 15, 2015: Proceedings of the National Academy of Sciences of the United States of America
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"