bluuebunny/crossref_metadata_2025_split huggingface dataset:
GRASP‐Pro: imProving GRASP DCE‐MRI through self‐calibrating subspace‐modeling and contrast phase automation
Authors: Feng Li , Wen Qiuting , Huang Chenchan , Tong Angela , Liu Fang , Chandarana Hersh 
Published: August 2019

PurposeTo propose a highly accelerated, high‐resolution dynamic contrast‐enhanced MRI (DCE‐MRI) technique called GRASP‐Pro (golden‐angle radial sparse parallel imaging with imProved performance) through a joint sparsity and self‐calibrating subspace constraint with automated selection of contrast phases.MethodsGRASP‐Pro reconstruction enforces a combination of an explicit low‐rank subspace‐constraint and a temporal sparsity constraint. The temporal basis used to construct the subspace is learned from an intermediate reconstruction step using the low‐resolution portion of radial k‐space, which eliminates the need for generating the basis using auxiliary data or a physical signal model. A convolutional neural network was trained to generate the contrast enhancement curve in the artery, from which clinically relevant contrast phases are automatically selected for evaluation. The performance of GRASP‐Pro was demonstrated for high spatiotemporal resolution DCE‐MRI of the prostate and was compared against standard GRASP in terms of overall image quality, image sharpness, and residual streaks and/or noise level.ResultsCompared to GRASP, GRASP‐Pro reconstructed dynamic images with enhanced sharpness, less residual streaks and/or noise, and finer delineation of the prostate without prolonging reconstruction time. The image quality improvement reached statistical significance (P < 0.05) in all the assessment categories. The neural network successfully generated contrast enhancement curves in the artery, and corresponding peak enhancement indexes correlated well with that from the manual selection.ConclusionGRASP‐Pro is a promising method for rapid and continuous DCE‐MRI. It enables superior reconstruction performance over standard GRASP and allows reliable generation of artery enhancement curve to guide the selection of desired contrast phases for improving the efficiency of GRASP MRI workflow.
Fat navigators and Moiré phase tracking comparison for motion estimation and retrospective correction
Authors: Gretsch Frédéric , Mattern Hendrik , Gallichan Daniel , Speck Oliver 
Published: August 2019

PurposeTo compare motion tracking by two modern methods (fat navigators [FatNavs] and Moiré phase tracking [MPT]) as well as their performance for retrospective correction of very high resolution acquisitions.MethodsA direct comparison of FatNavs and MPT motion parameters was performed for several deliberate motion patterns to estimate the agreement between methods. In addition, two different navigator resolution were applied. 0.5 mm isotropic MP2RAGE images with simultaneous MPT and FatNavs tracking were acquired in 9 cooperative subjects with no intentional motion. Retrospective motion corrections based on both tracking modalities were compared qualitatively and quantitatively. The FatNavs impact on quantitative T1 maps was also investigated.ResultsBoth methods showed good agreement within a 0.3 mm/° margin in subjects that moved very little. Higher resolution FatNavs (2 mm) showed overall better agreement with MPT than 4 mm resolution ones, except for fast and large motion. The retrospective motion corrections based on MPT or FatNavs were at par in 33 cases out of 36, and visibly improved image quality compared to the uncorrected images. In separate fringe cases, both methods suffered from their respective potential shortcomings: unreliable marker attachment for MPT and poor temporal resolution for FatNavs. The magnetization transfer induced by the navigator RF pulses had a visible impact on the T1 values distribution, with a shift of the gray and white matter peaks of 12 ms at most.ConclusionThis work confirms both FatNavs and MPT as excellent retrospective motion correction methods for very high resolution imaging of cooperative subjects.
Whole‐heart T1 mapping using a 2D fat image navigator for respiratory motion compensation
Authors: Nordio Giovanna , Schneider Torben , Cruz Gastao , Correia Teresa , Bustin Aurelien , Prieto Claudia , Botnar René M. , Henningsson Markus 
Published: August 2019

PurposeTo combine a 3D saturation‐recovery‐based myocardial T1 mapping (3D SASHA) sequence with a 2D image navigator with fat excitation (fat‐iNAV) to allow 3D T1 maps with 100% respiratory scan efficiency and predictable scan time.MethodsData from T1 phantom and 10 subjects were acquired at 1.5T. For respiratory motion compensation, a 2D fat‐iNAV was acquired before each 3D SASHA k‐space segment to correct for 2D translational motion in a beat‐to‐beat fashion. The effect of the fat‐iNAV on the 3D SASHA T1 estimation was evaluated on the T1 phantom. For 3 representative subjects, the proposed free‐breathing 3D SASHA with fat‐iNAV was compared to the original implementation with the diaphragmatic navigator. The 3D SASHA with fat‐iNAV was compared to the breath‐hold 2D SASHA sequence in terms of accuracy and precision.ResultsIn the phantom study, the Bland‐Altman plot shows that the 2D fat‐iNAVs does not affect the T1 quantification of the 3D SASHA acquisition (0 ± 12.5 ms). For the in vivo study, the 2D fat‐iNAV permits to estimate the respiratory motion of the heart, while allowing for 100% scan efficiency, improving the precision of the T1 measurement compared to non‐motion‐corrected 3D SASHA. However, the image quality achieved with the proposed 3D SASHA with fat‐iNAV is lower compared to the original implementation, with reduced delineation of the myocardial borders and papillary muscles.ConclusionsWe demonstrate the feasibility to combine the 3D SASHA T1 mapping imaging sequence with a 2D fat‐iNAV for respiratory motion compensation, allowing 100% respiratory scan efficiency and predictable scan time.
Dissolved hyperpolarized xenon‐129 MRI in human kidneys
Authors: Chacon‐Caldera Jorge , Maunder Adam , Rao Madhwesha , Norquay Graham , Rodgers Oliver I. , Clemence Matthew , Puddu Claudio , Schad Lothar R. , Wild Jim M. 
Published: August 2019

PurposeTo assess the feasibility of using dissolved hyperpolarized xenon‐129 (129Xe) MRI to study renal physiology in humans at 3 T.MethodsUsing a flexible transceiver RF coil, dynamic and spatially resolved 129Xe spectroscopy was performed in the abdomen after inhalation of hyperpolarized 129Xe gas with 3 healthy male volunteers. A transmit‐only receive‐only RF coil array was purpose‐built to focus RF excitation and enhance sensitivity for dynamic imaging of 129Xe uptake in the kidneys using spoiled gradient echo and balanced steady‐state sequences.ResultsUsing spatially resolved spectroscopy, different magnitudes of signal from 129Xe dissolved in red blood cells and tissue/plasma could be identified in the kidneys and the aorta. The spectra from both kidneys showed peaks with similar amplitudes and chemical shift values. Imaging with the purpose‐built coil array was shown to provide more than a 3‐fold higher SNR in the kidneys when compared with surrounding tissues, while further physiological information from the dissolved 129Xe in the lungs and in transit to the kidneys was provided with the transceiver coil. The signal of dissolved hyperpolarized 129Xe could be imaged with both tested sequences for about 40 seconds after inhalation.ConclusionThe uptake of 129Xe dissolved in the human kidneys was measured with spectroscopic and imaging experiments, demonstrating the potential of hyperpolarized 129Xe MR as a novel, noninvasive technique to image human kidney tissue perfusion.
Silent voices: Family caregivers' narratives of involvement in palliative care
Authors: Tarberg Anett Skorpen , Kvangarsnes Marit , Hole Torstein , Thronæs Morten , Madssen Torfinn Støve , Landstad Bodil J. 
Published: August 2019

AbstractAimTo explore how family caregivers experience involvement in palliative care.DesignA qualitative design with a narrative approach was used.MethodsPurposive sampling and narrative interviews were conducted. Eleven bereaved family caregivers for patients with cancer receiving palliative care were interviewed in Mid‐Norway between November 2016–May 2017.ResultsWe identified four themes related to family caregivers' experiences of involvement in the early, middle, terminal and bereavement phases of palliative care: (a) limited involvement in the early phase; (b) emphasis on patient‐centred care in the middle phase; (c) lack of preparation for the dying phase; and (d) lack of systematic follow‐up after death. Family caregivers experienced low level of involvement throughout the palliative pathway.ConclusionThe involvement of family caregivers in palliative care may not be proportional to their responsibilities. The needs of family caregivers should be addressed in nursing education to give nurses competence to support family caregivers in providing home‐based care.
Convergence and stability estimates in difference setting for time‐fractional parabolic equations with functional delay
Authors: Hendy Ahmed S. , Pimenov Vladimir G. , Macías‐Díaz Jorge E. 
Published: August 2019

AbstractA class of one‐dimensional time‐fractional parabolic differential equations with delay effects of functional type in the time component is numerically investigated in this work. To that end, a compact difference scheme is constructed for the numerical solution of those equations based on the idea of separating the current state and the prehistory function. In these terms, the prehistory function is approximated by means of an appropriate interpolation–extrapolation operator. A discrete form of the fractional Gronwall inequality is employed to provide an optimal error estimate. The existence and uniqueness of the numerical solutions, the order of approximation error for the constructed scheme, the stability and the order of convergence are mathematically investigated in this work.
Overactivity or blockade of transforming growth factor‐β each generate a specific ureter malformation
Authors: Lopes Filipa M , Roberts Neil A , Zeef Leo AH , Gardiner Natalie J , Woolf Adrian S 
Published: August 2019

AbstractTransforming growth factor‐β (TGFβ) has been reported to be dysregulated in malformed ureters. There exists, however, little information on whether altered TGFβ levels actually perturb ureter development. We therefore hypothesised that TGFβ has functional effects on ureter morphogenesis. Tgfb1, Tgfb2 and Tgfb3 transcripts coding for TGFβ ligands, as well as Tgfbr1 and Tgfbr2 coding for TGFβ receptors, were detected by quantitative polymerase chain reaction in embryonic mouse ureters collected over a wide range of stages. As assessed by in situ hybridisation and immunohistochemistry, the two receptors were detected in embryonic urothelia. Next, TGFβ1 was added to serum‐free cultures of embryonic day 15 mouse ureters. These organs contain immature smooth muscle and urothelial layers and their in vivo potential to grow and acquire peristaltic function can be replicated in serum‐free organ culture. Such organs therefore constitute a suitable developmental stage with which to define roles of factors that affect ureter growth and functional differentiation. Exogenous TGFβ1 inhibited growth of the ureter tube and generated cocoon‐like dysmorphogenesis. RNA sequencing suggested that altered levels of transcripts encoding certain fibroblast growth factors (FGFs) followed exposure to TGFβ. In serum‐free organ culture exogenous FGF10 but not FGF18 abrogated certain dysmorphic effects mediated by exogenous TGFβ1. To assess whether an endogenous TGFβ axis functions in developing ureters, embryonic day 15 explants were exposed to TGFβ receptor chemical blockade; growth of the ureter was enhanced, and aberrant bud‐like structures arose from the urothelial tube. The muscle layer was attenuated around these buds, and peristalsis was compromised. To determine whether TGFβ effects were limited to one stage, explants of mouse embryonic day 13 ureters, more primitive organs, were exposed to exogenous TGFβ1, again generating cocoon‐like structures, and to TGFβ receptor blockade, again generating ectopic buds. As for the mouse studies, immunostaining of normal embryonic human ureters detected TGFβRI and TGFβRII in urothelia. Collectively, these observations reveal unsuspected regulatory roles for endogenous TGFβ in embryonic ureters, fine‐tuning morphogenesis and functional differentiation. Our results also support the hypothesis that the TGFβ up‐regulation reported in ureter malformations impacts on pathobiology. Further experiments are needed to unravel the intracellular signalling mechanisms involved in these dysmorphic responses. © 2019 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
Secondary hemophagocytic syndrome after autologous hematopoietic cell transplant and immune therapy for neuroblastoma
Authors: Epperly Rebecca , Furman Wayne , Hines Melissa , Santiago Teresa , Li Ying , Madden Renee , Mamcarz Ewelina , Cervi David , Federico Sara , Triplett Brandon , Talleur Aimee 
Published: August 2019

AbstractSecondary hemophagocytic syndrome (HPS) has been described after autologous hematopoietic cell transplant (AutoHCT). We report two cases of secondary HPS after novel consolidation therapy for high‐risk neuroblastoma as part of an institutional phase 2 trial incorporating immunotherapy into a “standard” AutoHCT regimen. Both patients developed liver dysfunction beyond expected course of hepatic veno‐occlusive disease, coagulopathy, hyperferritinemia, and when evaluated, elevated soluble interleukin‐2 receptor and hemophagocytosis. These cases highlight the need for clinicians to have a high index of suspicion for immune‐related complications in patients receiving immune therapies.
Modified hemp fibers intended for fiber‐reinforced polymer composites used in structural applications—A review. I. Methods of modification
Authors: Tanasă Fulga , Zănoagă Mădălina , Teacă Carmen‐Alice , Nechifor Mărioara , Shahzad Asim 
Published: August 2019

AbstractNatural fiber composites have experienced a renaissance in the last two decades as a response to societal demands for developing eco‐friendly, biodegradable and recyclable materials. They are now being extensively used in everyday products as well as in automotive, packaging, sports and construction industries. Hemp fiber is being used in most of these products because of its superior mechanical properties. Like other natural fibers, hemp fibers require modifications in order to improve their properties and interfacial bonding with polymer matrices, and to reduce their hydrophilic character. These modification methods can be grouped into three major categories: chemical, physical and biological. Chemical methods use chemical reagents to reduce fibers' hydrophilic tendency and thus improve compatibility with the matrix. They also expose more reactive groups on the fiber surface to facilitate efficient coupling with the matrix. Physical methods change structural and surface properties of the fiber and thereby influence the interfacial bonding with matrices, without extensively changing the chemical composition of the fibers. They are cleaner and simpler than the chemical methods. Biological methods use biological agents like fungi, enzymes and bacteria to modify the fiber surface properties. These methods are not toxic like chemical methods and are not energy‐intensive like physical methods. This paper presents an overview of recent developments in these methods. It is concluded that these methods almost invariably result in improvement in fiber/matrix interfacial bonding, resulting in increase in mechanical properties of the composites.
Treatment of Helicobacter pylori in Special Patient Populations
Authors: Nguyen Cynthia T. , Davis Kyle A. , Nisly Sarah A. , Li Julius 
Published: August 2019

Helicobacter pylori infection can lead to gastritis, gastric and duodenal ulcers, and gastric cancer. Consequently, complete eradication is the goal of therapy. First‐line therapy for H. pylori infection includes clarithromycin triple therapy (clarithromycin, proton pump inhibitor [PPI], and amoxicillin or metronidazole), bismuth quadruple therapy (bismuth salt, PPI, tetracycline, and metronidazole or amoxicillin), or concomitant therapy (clarithromycin, PPI, amoxicillin, and metronidazole). However, many patients have relative contraindications to the antibiotics included in these regimens, making therapy selection difficult. Furthermore, failure of initial therapy makes selection of second‐line therapy challenging due to concerns for potential resistance to agents included in the initial regimen. This review discusses H. pylori microbiology, including antibiotic resistance, and summarizes the existing evidence for first‐ and second‐line treatment regimens that may be considered for special populations such as patients with penicillin allergies, patients with or at risk for QTc‐interval prolongation, and patients who are pregnant, breastfeeding, or elderly.
Structure–property relationship of phenoxyimine ligands/metal chloride initiating systems for controlled cationic polymerizations of alkyl vinyl ethers
Authors: Kigoshi Sensho , Kanazawa Arihiro , Kanaoka Shokyoku , Aoshima Sadahito 
Published: August 2019

ABSTRACTThe catalyst structure–property relationships of the phenoxyimine complexes in controlled cationic polymerization of vinyl ethers were investigated based on the Hammett correlation. The correlation analyses of a series of experiments using the phenoxyimine ligands/TiCl4 initiating systems indicated that the substituents on the N‐aryl phenoxyimine ligands affected the polymerization rate and stereoselectivity. Importantly, a linear correlation was observed between the Hammett substituent constants and the polymerization rates, which indicates that the Lewis acidity of the complex is affected by the electron‐withdrawing and ‐donating effects of the substituents. The tacticity of product polymers correlated to the Hammett substituent constants. Unlike the relationship with the polymerization rates, the σ– values, which account for the enhanced resonance effects, were more appropriate for the relationship with the tacticity than the normal σ values. In contrast, the polymerization behavior using o‐substituted ligands exhibited a trend different from those using p‐ or m‐substituted ligands. The structural change, which was caused by the rotation of the CN bonding, most likely triggered the acceleration effect in the case of the o‐substituents. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2021–2029
Lessons learned from analyzing an explosion at Shanghai SECCO petrochemical plant
Authors: Dong Hanhai , Liu Yi , Zhao Dongfeng , Qi Meng , Chen Jian , Wang Yanchun , Wang Wei 
Published: August 2019

AbstractOn May 12, 2018, six workers from Shanghai AIJINKE Engineering Construction Services Co. died on the spot of an explosion when they were maintaining a benzene tank at Shanghai SECCO Petrochemical Co. The incident was characterized as a disastrous incident caused by hot work in a confined space. This article aimed to analyze the incident in a chronological order by using the event sequence diagram. The FLACS software was used to simulate the variation of pressure and temperature over time when benzene vapor was ignited in the tank. Multilayer bow‐tie analysis was adopted to explore the causes of the explosion, along with the corresponding consequences, and preventive measures. The analyses show that the primary causes were the unsafe behaviors of on‐site workers, hazardous conditions of in‐tank substances, risky factors in the construction environment, and deficiencies in process safety management. Based on the qualitative and quantitative analyses, we emphasize three considerable reasons, which include inappropriate flammable gas detection before the operation, failing to test for flammable gases during the hot work, and deficiency of the Management of Change. Finally, the article concludes with a summary of lessons learned as well as suggestions for incident prevention and safety improvement.
Identification and geographical distribution of pyrethroid resistance mutations in the poultry red mite Dermanyssus gallinae
Authors: Katsavou Evangelia , Vlogiannitis Spyros , Karp‐Tatham Eleanor , Blake Damer P , Ilias Aris , Strube Christina , Kioulos Ilias , Dermauw Wannes , Van Leeuwen Thomas , Vontas John 
Published: August 2019

AbstractBackgroundThe poultry red mite (PRM) Dermanyssus gallinae is the most common ectoparasite on poultry and causes high economic losses in poultry farming worldwide. Pyrethroid acaricides have been widely used for its control and, consequently, pyrethroid resistance has arisen. In this study we aim to investigate the occurrence of resistance and study the geographical distribution of pyrethroid resistance mutations across PRM populations in Europe.ResultsFull dose–response contact bioassays revealed very high levels of resistance against several pyrethroids (α‐cypermethrin, fluvalinate, and cyfluthrin) in two PRM populations from Greece, compared to a susceptible reference strain. Resistance was associated with mutations in the gene encoding the target site of pyrethroids, the voltage‐gated sodium channel (VGSC). Mutations, M918L and L925V in domain IIS4‐S5 and F1534L in domain IIIS6, were found at positions known to play a role in pyrethroid resistance in other arthropod species. Subsequent screening by sequencing VGSC gene fragments IIS4‐S5 and IIIS6 revealed the presence and distribution of these mutations in many European populations. In some populations, we identified additional or different mutations including M918V/T, L925M, T929I, I936F, and F1538L. The latter mutation is a possible alternative for F1538I that has been previously associated with pyrethroid resistance in other Acari species.ConclusionWe report very high levels of pyrethroid resistance in PRM populations from Greece, as well as the identification and geographical distribution of 10 pyrethroid resistance mutations in PRM populations across Europe. Our results draw attention to the need for an evidence‐based implementation of PRM control, taking acaricide resistance management into consideration. © 2019 Society of Chemical Industry
Elimination of spectral blocking by ensuring rotation‐free property of discretized pressure gradient within a spectral semi‐implicit semi‐Lagrangian global atmospheric model
Authors: Ujiie Masashi , Hotta Daisuke 
Published: August 2019

AbstractThe widely‐adopted discretization of the horizontal pressure gradient term formulated by Simmons and Burridge for atmospheric models on σ‐p hybrid vertical coordinate is found to incur spectral blocking for rotational wind components at high vertical levels when used in a spectral semi‐Lagrangian model run on a linear grid. A remedy to this issue is proposed and tested using a spectral semi‐implicit semi‐Lagrangian hydrostatic primitive equations model. The proposed method removes aliasing errors at high wave‐numbers by ensuring that the rotation‐free property of the pressure gradient term on the isobaric surface, a feature possessed by the continuous system, is preserved in the discretized system, which highlights the significance of mimetic discretization within the context of numerical weather prediction models.