bluuebunny/crossref_metadata_2025_split huggingface dataset:
Stereotactic radiosurgery planning of vestibular schwannomas: IsMRIat 3 Tesla geometrically accurate?
Authors: Schmidt M. A. , Wells E. J. , Davison K. , Riddell A. M. , Welsh L. , Saran F. 
Published: December 2016

PurposeMRIis a mandatory requirement to accurately plan Stereotactic Radiosurgery (SRS) for Vestibular Schwannomas. However,MRImay be distorted due not only to inhomogeneity of the static magnetic field and gradients but also due to susceptibility‐induced effects, which are more prominent at higher magnetic fields. We assess geometrical distortions around air spaces and considerMRIprotocol requirements forSRSplanning at 3 T.MethodsHardware‐related distortion and the effect of incorrect shimming were investigated with structured test objects. The magnetic field was mapped over the head on five volunteers to assess susceptibility‐related distortion in the naso‐oro‐pharyngeal cavities (NOPC) and around the internal ear canal (IAC).ResultsHardware‐related geometric displacements were found to be less than 0.45 mm within the head volume, after distortion correction. Shimming errors can lead to displacements of up to 4 mm, but errors of this magnitude are unlikely to arise in practice. Susceptibility‐related field inhomogeneity was under 3.4 ppm, 2.8 ppm, and 2.7 ppm for the head,NOPCregion andIACregion, respectively. For theSRSplanning protocol (890 Hz/pixel, approximately 1 mm3isotropic), susceptibility‐related displacements were less than 0.5 mm (head), and 0.4 mm (IACandNOPC). Large displacements are possible inMRIexaminations undertaken with lower receiver bandwidth values, commonly used in clinicalMRI. Higher receiver bandwidth makes the protocol less vulnerable to sub‐optimal shimming. The shimming volume and theCT‐MRco‐registration must be considered jointly.ConclusionGeometric displacements can be kept under 1 mm in the vicinity of air spaces within the head at 3 T with appropriate setting of the receiver bandwidth, correct shimming and employing distortion correction.
A novel objective method for assessing high‐contrast spatial resolution in CT based on the Rayleigh criterion
Authors: Zhang Pu , Wan Guoqing , Li Fei , Li Xingdong , Liu Wenli , Wang Guangzhi 
Published: December 2016

PurposeIn China, most quality assessments (QAs) of the high‐contrast resolution of medical computed tomography (CT) equipment is performed by subjective evaluation, which is simple but dependent on observer expertise. The purpose of this study was to compare the accuracy and degree of dispersion of evaluation results from observers with different expertise and to develop an objective, easily understandable new approach to minimize the error caused by the subjective nature of observer evaluation. The accuracy and reproducibility of this new approach was validated and compared using both subjective and objective evaluation methods.MethodsThis new objective evaluation method of high‐contrast resolution was based on measurements of CT phantom images. The intensity profile of the aluminum line pairs’ (LPs’) images was extracted and quantified following the Rayleigh criterion. The interpolation method was employed to improve the consistency of the middle profile lines of each LP group for application of the Rayleigh criterion. With the introduction of a normalized margin, the accuracy of the results increased to the decimal level. Five junior observers and three QA professionals evaluated the high‐contrast resolution of three different CT scanners using the subjective method, modulation transfer function (MTF) method, and the new objective method, and the results were compared statistically.ResultsThe experimental standard deviations ranged from 0.4 LP/cm to 0.55 LP/cm for subjective visual inspection. The uncertainty of the expert group's results was much lower than that of the volunteer group. The experimental standard deviations of the MTF evaluation, according to both the standard deviation (SD) and point spread function (PSF) methods, were within the intervals of (0.04–0.06) LP/cm and (0.08–0.16) LP/cm, whereas that of the proposed objective evaluation method was approximately 0.02 LP/cm. The experimental data indicated that the results of the new objective evaluation were in accordance with those of the expert group's subjective evaluation and the MTF evaluation.ConclusionsIn this study, the subjective evaluation results from experienced observers showed relatively less uncertainty and more accuracy than those from inexperienced observers. Furthermore, a new objective evaluation approach that is easily understood, accurate, and reproducible was developed in this study. Results acquired using this new method were comparable with those of expert groups’ subjective evaluation and MTF evaluation. Specialized QA software that integrates the steps implemented in the new method is being developed to enhance the convenience of the approach and assist observers in obtaining accurate and replicable assessment results.
Use of pattern recognition for unaliasing simultaneously acquired slices in simultaneous multislice MR fingerprinting
Authors: Jiang Yun , Ma Dan , Bhat Himanshu , Ye Huihui , Cauley Stephen F. , Wald Lawrence L. , Setsompop Kawin , Griswold Mark A. 
Published: December 2016

PurposeThe purpose of this study is to accelerate an MR fingerprinting (MRF) acquisition by using a simultaneous multislice method.MethodsA multiband radiofrequency (RF) pulse was designed to excite two slices with different flip angles and phases. The signals of two slices were driven to be as orthogonal as possible. The mixed and undersampled MRF signal was matched to two dictionaries to retrieve T1 and T2 maps of each slice. Quantitative results from the proposed method were validated with the gold‐standard spin echo methods in a phantom. T1 and T2 maps of in vivo human brain from two simultaneously acquired slices were also compared to the results of fast imaging with steady‐state precession based MRF method (MRF‐FISP) with a single‐band RF excitation.ResultsThe phantom results showed that the simultaneous multislice imaging MRF–FISP method quantified the relaxation properties accurately compared to the gold‐standard spin echo methods. T1 and T2 values of in vivo brain from the proposed method also matched the results from the normal MRF–FISP acquisition.ConclusionT1 and T2 values can be quantified at a multiband acceleration factor of two using our proposed acquisition even in a single‐channel receive coil. Further acceleration could be achieved by combining this method with parallel imaging or iterative reconstruction. Magn Reson Med 78:1870–1876, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Flow‐suppressed hyperpolarized 13C chemical shift imaging using velocity‐optimized bipolar gradient in mouse liver tumors at 9.4 T
Authors: Lee Hansol , Lee Joonsung , Joe Eunhae , Yang Seungwook , Song Jae Eun , Choi Young‐Suk , Wang Eunkyung , Joo Chan Gyu , Song Ho‐Taek , Kim Dong‐Hyun 
Published: December 2016

PurposeTo optimize and investigate the influence of bipolar gradients for flow suppression in metabolic quantification of hyperpolarized 13C chemical shift imaging (CSI) of mouse liver at 9.4 T.MethodsThe trade‐off between the amount of flow suppression using bipolar gradients and
effect from static spins was simulated. A free induction decay CSI sequence with alternations between the flow‐suppressed and non–flow‐suppressed acquisitions for each repetition time was developed and was applied to liver tumor–bearing mice via injection of hyperpolarized [1‐13C] pyruvate.ResultsThe in vivo results from flow suppression using the velocity‐optimized bipolar gradient were comparable with the simulation results. The vascular signal was adequately suppressed and signal loss in stationary tissue was minimized. Application of the velocity‐optimized bipolar gradient to tumor‐bearing mice showed reduction in the vessel‐derived pyruvate signal contamination, and the average lactate/pyruvate ratio increased by 0.095 (P < 0.05) in the tumor region after flow suppression.ConclusionOptimization of the bipolar gradient is essential because of the short 13C
and high signal in venous flow in the mouse liver. The proposed velocity‐optimized bipolar gradient can suppress the vascular signal, minimizing
‐related signal loss in stationary tissues at 9.4 T. Magn Reson Med 78:1674–1682, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
(S)Pinning down protein interactions by NMR
Authors: Teilum Kaare , Kunze Micha Ben Achim , Erlendsson Simon , Kragelund Birthe B. 
Published: December 2016

AbstractProtein molecules are highly diverse communication platforms and their interaction repertoire stretches from atoms over small molecules such as sugars and lipids to macromolecules. An important route to understanding molecular communication is to quantitatively describe their interactions. These types of analyses determine the amounts and proportions of individual constituents that participate in a reaction as well as their rates of reactions and their thermodynamics. Although many different methods are available, there is currently no single method able to quantitatively capture and describe all types of protein reactions, which can span orders of magnitudes in affinities, reaction rates, and lifetimes of states. As the more versatile technique, solution NMR spectroscopy offers a remarkable catalogue of methods that can be successfully applied to the quantitative as well as qualitative descriptions of protein interactions. In this review we provide an easy‐access approach to NMR for the non‐NMR specialist and describe how and when solution state NMR spectroscopy is the method of choice for addressing protein ligand interaction. We describe very briefly the theoretical background and illustrate simple protein–ligand interactions as well as typical strategies for measuring binding constants using NMR spectroscopy. Finally, this review provides examples of caveats of the method as well as the options to improve the outcome of an NMR analysis of a protein interaction reaction.
No influence of CO2 on stable isotope analyses of soil waters with off‐axis integrated cavity output spectroscopy (OA‐ICOS)
Authors: Sprenger Matthias , Tetzlaff Doerthe , Soulsby Chris 
Published: December 2016

RationaleIt was recently shown that the presence of CO2 affects the stable isotope (δ2H and δ18O values) analysis of water vapor via Wavelength‐Scanned Cavity Ring‐Down Spectroscopy. Here, we test how much CO2 is emitted from soil samples and if the CO2 in the headspace influences the isotope analysis with the direct equilibration method by Off‐Axis Integrated Cavity Output Spectroscopy (OA‐ICOS).MethodsThe headspace above different amounts of sparkling water was sampled, and its stable isotopic composition (δ2H and δ18O values) and CO2 concentration were measured by direct equilibration and by gas chromatography, respectively. In addition, the headspace above soil samples was analyzed in the same way. Furthermore, the gravimetric water content and the loss on ignition were measured for the soil samples.ResultsThe experiment with the sparkling water showed that CO2 does not influence the stable isotope analysis by OA‐ICOS. CO2 was emitted from the soil samples and correlated with the isotopic fractionation signal, but no causal relationship between the two was determined. Instead, the fractionation signal in pore water isotopes can be explained by soil evaporation and the CO2 can be related to soil moisture and organic matter which both enhance microbial activity.ConclusionsWe found, despite the high CO2 emissions from soil samples, no need for a post‐correction of the pore water stable isotope analysis results, since there is no relation between CO2 concentrations and the stable isotope results of vapor samples obtained with OA‐ICOS. © 2016 The Authors. Rapid Communications in Mass Spectrometry Published by John Wiley & Sons Ltd.
Robust cooperative output regulation of heterogeneous Lur'e networks
Authors: Zhang Fan , Trentelman Harry L. , Scherpen Jacquelien M. A. 
Published: December 2016

SummaryIn this paper, we study robust cooperative output regulation problems for a directed network of Lur'e systems that consist of a nominal linear dynamics with an unknown static nonlinearity around it through negative feedback. We assume that the linear part of each agent is identical, but the nonlinearities are allowed to be different for distinct agents. In this sense, the network is heterogeneous. As is common in the context of Lur'e systems, the unknown nonlinearities are assumed to be sector bounded within one given sector. The interconnection graph among these agents is assumed to contain a directed spanning tree. Similar to classical output regulation problems, there is a virtual exosystem generating a reference signal in which all the agents are required to track cooperatively. Our designed distributed dynamic state/output feedback protocol makes a copy of the reference signal at each agent asymptotically, and then the robust cooperative output regulation problem becomes a robust tracking problem that can be handled by each agent via local information. It turns out that our cooperative protocols are fully distributed. Sufficient conditions on the existence of output synchronization protocols are given along with some discussions on these conditions. Finally, two simulation examples illustrate our design. Copyright © 2016 John Wiley & Sons, Ltd.
Data representation for time series data mining: time domain approaches
Authors: Wilson Seunghye J. 
Published: December 2016

In most time series data mining, alternate forms of data representation or data preprocessing is required because of the unique characteristics of time series, such as high dimension (the number of data points), presence of random noise, and nonlinear relationship of the data elements. Therefore, any data representation method aims to achieve substantial data reduction to a manageable size, while preserving important characteristics of the original data, and robustness to random noise. Moreover, appropriate choice of a data representation method may result in meaningful data mining. Many high level representation methods of time series data are based on time domain approaches. These methods preprocess the original data in the time domain directly and are useful to understand the behavior of data over time. Piecewise approximation, data representation by identification important points, and symbolic representation are some of the main ideas of time domain approaches, and widely used in various fields. WIREs Comput Stat 2017, 9:e1392. doi: 10.1002/wics.1392This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Dimension Reduction
Statistical and Graphical Methods of Data Analysis > Data Reduction, Smoothing, and Filtering
Microbial community composition regulates SOC decomposition response to forest conversion in a Chinese temperate forest
Authors: Qi Lin , Yang Jian 
Published: December 2016

AbstractForest conversion influences soil organic carbon (SOC) decomposition through cascading effects on forest structure, soil properties, and soil microbial communities. However, interactive effects of these drivers and the key pathways that mediate forest SOC decomposition remain relatively unexplored. In this study, we compared relative importance of variables describing forest structure, soil properties, and soil microbial community on affecting SOC decomposition response to the conversion of a broadleaved Korean pine mixed forest into three other forests in the Changbai Mountains of China. We quantified SOC decomposition rate of these four forest types by measuring incubation soil respiration (SR). We then employed univariate regressions to quantify effect size of individual factor on SOC decomposition rate. A structural equation model (SEM) was developed to analyze pathways, relative importance, and interactive effects of these factors on SR. Our results showed strong marginal effects of dissolved organic carbon (DOC) content, fungal Phospholipid fatty acids (PLFAs) to bacterial PLFAs ratio (F/B), broadleaved to conifer ratio (B/C), and total PLFAs content (TPC) on SR. Measured SOC decomposition rate was most closely related to F/B, which was in turn influenced primarily by soil C/N ratio and fraction of non‐oxidized carbon (NOC%). Our study identified “Aboveground forest composition → SOC chemistry → Soil microbial composition → SOC decomposition” as the key pathway by which forest conversion affected SOC decomposition. This research work highlights the critical role of soil microbial community composition in altering SOC decomposition response to forest conversion.
A developmentally informed adaptation of minority stress for sexual minority adolescents
Authors: Goldbach Jeremy T. , Gibbs Jeremy J. 
Published: December 2016

ABSTRACTSexual minority adolescents (lesbian, gay, bisexual) experience disparities in behavioral health outcomes compared to their heterosexual peers, generally attributed to minority stress. Although evidence of the applicability of the minority stress model among adolescents exists, it is based on a primarily adult literature. Developmental and generational differences demand further examination of minority stress to confirm its applicability. Forty‐eight life history interviews with sexual minority adolescents in California (age 14–19; M = 19.27 SD = 1.38; 39.6% cismale, 35.4% cisfemale, 25% other gender) were completed, recorded, transcribed, and analyzed using thematic analysis in QSR NVivo. Following a consensus model, all transcripts were double coded. Results suggest that minority stress is appropriate for use with adolescents; however, further emphasis should be placed on social context, coping resources, and developmental processes regarding identity development. A conceptual model is provided, as are implications for research and practice.
SFPQ associates to LSD1 and regulates the migration of newborn pyramidal neurons in the developing cerebral cortex
Authors: Saud K. , Cánovas J. , Lopez C.I. , Berndt F.A. , López E. , Maass J.C. , Barriga A. , Kukuljan M. 
Published: December 2016

AbstractThe development of the cerebral cortex requires the coordination of multiple processes ranging from the proliferation of progenitors to the migration and establishment of connectivity of the newborn neurons. Epigenetic regulation carried out by the COREST/LSD1 complex has been identified as a mechanism that regulates the development of pyramidal neurons of the cerebral cortex. We now identify the association of the multifunctional RNA‐binding protein SFPQ to LSD1 during the development of the cerebral cortex. In vivo reduction of SFPQ dosage by in utero electroporation of a shRNA results in impaired radial migration of newborn pyramidal neurons, in a similar way to that observed when COREST or LSD1 expressions are decreased. Diminished SFPQ expression also associates to decreased proliferation of progenitor cells, while it does not affect the acquisition of neuronal fate. These results are compatible with the idea that SFPQ, plays an important role regulating proliferation and migration during the development of the cerebral cortex.
Variations in Echogenicity in Carotid and Femoral Atherosclerotic Plaques with Pycnogenol + Centella Asiatica Supplementation
Authors: Cornelli Umberto , Belcaro Gianni 
Published: December 2016

AbstractThis registry study evaluated echogenicity of carotid–femoral plaques in asymptomatic subjects with increased oxidative stress and risk factors (mild hypertension, hypercholesterolemia). Supplementation with the combination Pycnogenol–CA (centella asiatica) on the echogenicity of plaques was assessed at 6 months (79 subjects). A standard management (SM) plan was used in all subjects (control of risk factors, lifestyle changes); 36 subjects used the supplements +SM; 43 SM only. The groups were comparable. High-resolution ultrasound evaluated echogenicity and plaque structure. Pycnogenol (150 mg/day) and CA (Centellicum, 450 mg/day) were used.At 6 months, cholesterol was reduced (p < 0.05) in both groups (difference between groups not significant). At 6 months, plasma free radicals were decreased with the supplements (17.64%; p < 0.05; vs <2% in controls). The plaque stability index increased from 11.22;2.3 to 22.4;1.1 (p < 0.05) with the supplements; no significant changes were seen in controls. Plaque echogenicity (% of “whiter” component in images) increased with supplementation from 16.7;1.7% to 34.2;2% (p < 0.05); no variations were observed in controls. The maximum plaque height decreased (p < 0.05) with the supplements. No significant variations were observed in controls. Plaque length was decreased (p < 0.05) in the supplement group with no changes in controls. The number of plaques (carotid, femoral bifurcations) decreased with supplementation; no significant changes were observed in controls. No adverse events, tolerability problems, or variations in routine blood tests were recorded. The combination Pycnogenol–CA appears to improve echogenicity and stability of complex plaques in 6 months.
A Canine Arthroscopic Anterior Cruciate Ligament Reconstruction Model for Study of Synthetic Augmentation of Tendon Allografts
Authors: Smith Pat , Stannard James , Pfeiffer Ferris , Kuroki Keiichi , Bozynski Chantelle , Cook Cristi , Cook James 
Published: December 2016

AbstractNovel graft types, fixation methods, and means for augmenting anterior cruciate ligament (ACL) reconstructions require preclinical validation prior to safe and effective clinical application. The objective of this study was to describe and validate a translational canine model for all-inside arthroscopic complete ACL reconstruction using a quadriceps tendon allograft with internal brace (QTIB). With institutional approval, adult research hounds underwent complete transection of the native ACL followed by all-inside ACL reconstruction using the novel QTIB construct with suspensory fixation (n = 10). Contralateral knees were used as nonoperated controls (n = 10). Dogs were assessed over a 6-month period using functional, diagnostic imaging, gross, biomechanical, and histologic outcome measures required for preclinical animal models. Study results suggest that the novel QTIB construct used for complete ACL reconstruction can provide sustained knee stability and function without the development of premature osteoarthritis in a rigorous and valid preclinical model. The unique configuration of the QTIB construct—the combination of a tendon allograft with a synthetic suture tape internal brace—allowed for an effective biologic–synthetic load-sharing ACL construct. It prevented early failure, allowed for direct, four-zone graft-to-bone healing, and functional graft remodeling while avoiding problems noted with use of all-synthetic grafts.
Suspension medium's impact on the EPD of nano-YSZ on Fecralloy
Authors: Khanali O. , Rajabi M. , Baghshahi S. , Ariaee S. 
Published: December 2016

Electrophoretic deposition (EPD) was employed to coat yttria-stabilised zirconia (YSZ) on Fecralloy. Various non-aqueous solvents were utilised to achieve smooth crack-free YSZ coatings. The EPD parameters, including solvent type, sedimentation height, zeta potential, particle size, pH and deposition weight, were studied. The micro-structural evolution and mechanical properties of the coatings were studied by the field emission scanning electron microscopy and micro-hardness, respectively. It was found that coatings obtained from 0.4 g L−1 I2 acetyl–acetone were uniform, smooth and crack free. Also they had narrow particle size distributions and higher zeta potential in the suspension. The experimental results revealed that suspension stability was a requirement for obtaining high-quality coatings and deposition yield for stable suspensions was higher; however, particle coagulation resulted in coatings with low green density and poor sinter ability. A transition in deposition mechanism from linear to parabolic was observed during EPD where deposition rate was decreased by time. GRAPHICAL ABSTRACT