bluuebunny/crossref_metadata_2025_split huggingface dataset:
Solvent‐free Synthesis of Flowable Carbon Clusters with Customizable Size and Tunable Optical Performance
Authors: Li Denian , Li Qi , Hu Xuan , Huang Jing , Li Hairong , Dong Lijie , Xie Haian , Xiong Chuanxi 
Published: November 2013

AbstractWe propose a rapid and solvent‐free route for synthesizing luminous carbon clusters by controlling carbonization of polyethylene glycol (PEG). This approach does not involve solvents yet uses the precursor itself as suspending medium, thus features mild and green chemistry, and also enables the formation of uniform‐sized carbon clusters, of which the diameter can be easily tuned from 0.7 to 3.5 nm via control of reaction time. In term of the dimension, the resultants are denoted as sub‐nano carbon clusters (SNCs) and carbon dots (CDs), respectively. Benefiting from surface anchored PEG segments, both of the two show favorable flowability at room temperature and excellent solubility in aqueous and organic solvents. Comparison of their optical performances and structures reveals that they share the same chromophores. Particularly, the SNCs demonstrate robust photo‐ and pH‐stable photoluminescence and can be directly applied to cell‐imaging regarding to its prominent biocompatibility. Moreover, its quantum yield (5.5%), which is approximately 3 times higher than that of CDs (1.5%), can be dramatically enhanced to 18.8% by facile chemical reduction. We anticipate that these PEG derivatives marked with easy synthesis, controllable optical performances and excellent physical properties will be highly appealing in future applications.
Unified model for assessing checkpointing protocols at extreme‐scale
Authors: Bosilca George , Bouteiller Aurélien , Brunet Elisabeth , Cappello Franck , Dongarra Jack , Guermouche Amina , Herault Thomas , Robert Yves , Vivien Frédéric , Zaidouni Dounia 
Published: November 2013

SUMMARYIn this paper, we present a unified model for several well‐known checkpoint/restart protocols. The proposed model is generic enough to encompass both extremes of the checkpoint/restart space, from coordinated approaches to a variety of uncoordinated checkpoint strategies (with message logging). We identify a set of crucial parameters, instantiate them, and compare the expected efficiency of the fault tolerant protocols, for a given application/platform pair. We then propose a detailed analysis of several scenarios, including some of the most powerful currently available high performance computing platforms, as well as anticipated Exascale designs. The results of this analytical comparison are corroborated by a comprehensive set of simulations. Altogether, they outline comparative behaviors of checkpoint strategies at very large scale, thereby providing insight that is hardly accessible to direct experimentation. Copyright © 2013 John Wiley & Sons, Ltd.
Severe hypoglycaemia in type 1 diabetes mellitus: underlying drivers and potential strategies for successful prevention
Authors: Little S. A. , Leelarathna L. , Barendse S. M. , Walkinshaw E. , Tan H. K. , Lubina Solomon A. , de Zoysa N. , Rogers H. , Choudhary P. , Amiel S. A. , Heller S. R. , Evans M. , Flanagan D. , Speight J. , Shaw J. A. M. 
Published: November 2013

SummaryHypoglycaemia remains an over‐riding factor limiting optimal glycaemic control in type 1 diabetes. Severe hypoglycaemia is prevalent in almost half of those with long‐duration diabetes and is one of the most feared diabetes‐related complications. In this review, we present an overview of the increasing body of literature seeking to elucidate the underlying pathophysiology of severe hypoglycaemia and the limited evidence behind the strategies employed to prevent episodes. Drivers of severe hypoglycaemia including impaired counter‐regulation, hypoglycaemia‐associated autonomic failure, psychosocial and behavioural factors and neuroimaging correlates are discussed. Treatment strategies encompassing structured education, insulin analogue regimens, continuous subcutaneous insulin infusion pumps, continuous glucose sensing and beta‐cell replacement therapies have been employed, yet there is little randomized controlled trial evidence demonstrating effectiveness of new technologies in reducing severe hypoglycaemia. Optimally designed interventional trials evaluating these existing technologies and using modern methods of teaching patients flexible insulin use within structured education programmes with the specific goal of preventing severe hypoglycaemia are required. Individuals at high risk need to be monitored with meticulous collection of data on awareness, as well as frequency and severity of all hypoglycaemic episodes. Copyright © 2013 John Wiley & Sons, Ltd.
Iron(II) Complexes Based on π‐Conjugated Terpyridine Ligands with Tetrathiafulvalene or Its Radical Analogue
Authors: Hu Liang , Liu Wei , Li Cheng‐Hui , Zhou Xin‐Hui , Zuo Jing‐Lin 
Published: November 2013

AbstractTwo tetrathiafulvalene (TTF) functionalized 2,2′:6′,2″‐terpyridine derivatives, 4′‐tetrathiafulvalene‐2,2′:6′,2″‐terpyridine (L1) and 6,6″‐dimethyl‐4′‐tetrathiafulvalene‐2,2′:6′,2″‐terpyridine (L2), were synthesized and characterized. Based on L1 and L2, four electrochemically active TTF‐containing iron(II) complexes, [FeII(L1)2][ClO4]2 (1), [FeII(L1·+)2][ClO4]4 (2), [FeII(L1)2][CF3SO3]2 (3) and [FeII(L2)2][ClO4]2 (4), were successfully obtained. The preparation, spectroscopic and electrochemical properties of these new compounds as well as the crystal structures of complexes 1, 3 and 4 are described. Magnetic studies on 4 (with the ligand L2) suggest that the FeII ion is in the high‐spin state. Complex 2 was isolated as an interesting and stable open‐shell substance, and the free spin is mainly associated with the TTF radicals, as indicated by EPR, UV/Vis spectra, electrochemical analysis, spectroelectrochemical measurements and XPS spectra. After the oxidation and the formation of the radical cation, the electrical conductivity of 2 is almost 3 orders of magnitude higher than that of 1. DFT and TDDFT calculations provided insight into interpreting the electronic properties of complex 1 and its oxidized states.
New Members of the Cinchona Alkaloid Family: 9‐Aminoquincorine‐10‐aldehyde and 9‐Aminoquincoridine‐10‐aldehyde
Authors: Neda Ion , Fodor Elena , Maftei Catalin V. , Mihorianu Monica , Ambrosi Horst‐Dieter , Franz M. Heiko 
Published: November 2013

AbstractThis paper reports the synthesis of the new enantiopure amino aldehydes, 9‐aminoquincorine‐10‐aldehyde (1) and 9‐aminoquincoridine‐10‐aldehyde (2). These alkaloid‐like compounds are derivatives of the Cinchona alkaloids quinine and quinidine. Their application as chiral building blocks in the synthesis of novel compounds is demonstrated by the reduction and reductive amidation of the aldehyde moiety. Furthermore, their use in early drug discovery and supramolecular chemistry is described.
Modal pushover‐based scaling of earthquake records for nonlinear analysis of single‐story unsymmetric‐plan buildings
Authors: Reyes Juan C. , Quintero Oscar A. 
Published: November 2013

SUMMARYThe modal pushover‐based scaling (MPS) procedure, currently restricted to symmetric‐plan buildings, is extended herein to unsymmetric‐plan buildings. The accuracy of the extended MPS procedure was evaluated for a large set of three‐degree‐of‐freedom unsymmetric‐plan structures with variable stiffness and strength. The structures were subjected to nonlinear response history analysis considering sets of seven records scaled according to the MPS procedure. Structural responses were compared against the benchmark values, defined as the median values of the engineering demand parameters due to 30 unscaled records. This evaluation of the MPS procedure has led to the following conclusions: (i) the MPS procedure provided accurate estimates of median engineering demand parameter values and reduced record‐to‐record variability of the responses; and (2) the MPS procedure is found to be much superior compared to the ASCE/SEI 7‐10 scaling procedure for three‐dimensional analysis of unsymmetric‐plan buildings. Copyright © 2013 John Wiley & Sons, Ltd.
Clinical evaluation of the efficacy and safety of tandospirone versus sertraline monotherapy for social anxiety disorder: a randomized open‐label trial
Authors: Huang Xiao , Li Chao , Li Wei‐hui , Luo Yan‐li , Wang Biao , Zhang Wei , Gan Jian‐jun , Ji Jian‐lin 
Published: November 2013

ObjectiveAlthough selective serotonin reuptake inhibitors are now established as first‐line pharmacotherapy for social anxiety disorder (SAD), other agents with different mechanisms have shown promise in treating SAD. The aim of this study was to examine the efficacy and safety of tandospirone in treating adolescents with SAD.MethodsAdolescent patients meeting the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM‐IV) criteria for SAD were randomly assigned (1:1) to open‐label treatment with either tandospirone or sertraline for 8 weeks. The primary outcome measures were changes from baseline in the Hamilton Anxiety (HAM‐A) scale and response using the Clinical Global Impression of Improvement (CGI‐I) scale.ResultsThe adjusted mean change in HAM‐A scores from baseline was indicating a significant improvement over baseline in both treatment arms (p < 0.0001). The mean CGI‐I scale score at week was with no significant difference between the two arms (p = 0.42). Rates of response were 48.6% for tandospirone and 55.6% for sertraline using the CGI‐I. Response rates were 37.1% for tandospirone and 41.7% for sertraline using a HAM‐A response criterion (≥50% reduction). The adjusted mean change in Social Phobia Inventory scores from baseline was indicating a significant improvement over baseline in both treatment arms (p < 0.0001).ConclusionsTandospirone is safe and effective and appears non‐inferior to sertraline for SAD in youths. Copyright © 2013 John Wiley & Sons, Ltd.
Surface‐functionalized silica nanoparticles as fillers in polydimethylsiloxane membrane for the pervaporative recovery of 1‐butanol from aqueous solution
Authors: Beltran Arnel B. , Nisola Grace M. , Choi Shin Sik , Kim Younghee , Chung Wook‐Jin 
Published: November 2013

AbstractBACKGROUNDHybrid materials are being developed with improved separation properties as pervaporation (PV) membranes. Mixed matrix membranes (MMMs) containing surface‐functionalized fumed silica (SiO2) nanoparticles in polydimethylsiloxane (PDMS) were investigated for PV recovery of 1‐butanol. The MMMs were characterized through water contact angle, pure 1‐butanol sorption, degree of swelling and 1‐butanol partition coefficients.ResultsMost MMMs outperformed pure PDMS for the PV of 1.5% (w/v) 1‐butanol at ≤40°C. Functionalized SiO2 fillers enhanced the affinity of 1‐butanol to the MMMs (KBuOHG) which consequently improved 1‐butanol permeability more than that of water. Thus the MMMs exhibited better separation efficiencies, but those with octyl‐functionalized (Si‐DMOS) and phenyl‐functionalized SiO2 (Si‐DMPS) exhibited the best PV performance. Filler loading of 10 wt% Si‐DMOS and Si‐DMPS were found optimal for the PV performance of both MMMs. With temperature, component fluxes of both MMMs increased whereas permeability decreased. Based on PV separation index, both MMMs performed better than PDMS at ≤60°C, Si‐DMPS/PDMS MMM outperformed PDMS even at 70 °C.CONCLUSIONImproved performance of PV membranes was achieved when nonporous functionalized SiO2 nanoparticles, especially when Si‐DMPS is used as the filler. The MMMs developed may also be useful for organic compounds recovery from dilute aqueous solutions. © 2013 Society of Chemical Industry
Muscular system in the pacific bluefin tuna Thunnus orientalis (Teleostei: Scombridae)
Authors: Nakae Masanori , Sasaki Kunio , Shinohara Gento , Okada Tokihiko , Matsuura Keiichi 
Published: November 2013

ABSTRACTThe muscular system in the Pacific bluefin tuna Thunnus orientalis is studied in detail. For the first time, a complete description of the muscular anatomy of a thunnid is provided here. Eighty‐two elements including subdivisions of components of the muscular system are identified. This is less than found in a basal perciform and two other investigated scombrid species, owing mainly to the absence or fusion of pectoral, pelvic and caudal fin muscles. The absence of elements of the basal perciform pattern was most prominent in the caudal fin, which includes only the flexor dorsalis, flexor ventralis, hypochordal longitudinalis, and interradialis. In the caudal fin, the medial fan‐shaped ray was identified as the first dorsal ray, judging from myological and neuroanatomical characters. The highly developed gill filament muscles in Thunnus orientalis and sheet‐like rectus communis control gill ventilation. Long body muscle tendons reduce the metabolic energy needed during rapid and continuous swimming. These characters are interpreted as adaptations in the context of the oceanic life style of the species. J. Morphol. 275:217–229, 2014. © 2013 Wiley Periodicals, Inc.
Effect of temporal resolution on 4D flow MRI in the portal circulation
Authors: Landgraf Benjamin R. , Johnson Kevin M. , Roldán‐Alzate Alejandro , Francois Christopher J. , Wieben Oliver , Reeder Scott B. 
Published: November 2013

PurposeTo demonstrate the use of temporal averaging with radial 4D flow magnetic resonance imaging (MRI) to reduce scan time for quantification and visualization of flow in the portal circulation. This study compared phase‐contrast MR angiography, 3D flow visualization, and flow quantification of portal venous hemodynamics of time‐averaged vs. time‐resolved reconstructions.Materials and MethodsTime‐resolved 3D radial (“4D”) phase contrast data were acquired from 44 subjects (15 volunteers, 29 cirrhosis patients) at 3T. Images were reconstructed as a fully sampled time‐resolved reconstruction and multiple time‐averaged reconstructions using a variable number of acquired projections to simulate different scan times. Images from each reconstruction were evaluated to compare the quality of anatomical and hemodynamic visualization.ResultsTime‐averaged reconstructions outperformed time‐resolved reconstructions for flow quantification (3.9 ± 3.1% error vs. 5.2 ± 4.4% error), average streamline length (47 ± 7 mm vs. 34 ± 15 mm), and visualization quality (average grading = 3.7 ± 0.5 vs. 2.2 ± 0.9). In addition, excellent visualization quality was achieved using fewer acquired projections.ConclusionReductions in scan time can be achieved through time‐averaging while still providing excellent visualization and quantification in the portal circulation. Scan time reduction of up to 70%–80% was possible for high‐quality assessment, translating into a reduction in scan time from 10–12 minutes to ∼3–4 minutes. J. Magn. Reson. Imaging 2014;39:819–826. © 2013 Wiley Periodicals, Inc.
Measuring venous blood oxygenation in fetal brain using susceptibility‐weighted imaging
Authors: Neelavalli Jaladhar , Jella Pavan Kumar , Krishnamurthy Uday , Buch Sagar , Haacke E. Mark , Yeo Lami , Mody Swati , Katkuri Yashwanth , Bahado‐Singh Ray , Hassan Sonia S. , Romero Roberto , Thomason Moriah E. 
Published: November 2013

PurposeTo evaluate fetal cerebral venous blood oxygenation, Yv, using principles of MR susceptometry.Materials and MethodsA cohort of 19 pregnant subjects, with a mean gestational age of 31.6 ± 4.7 weeks were imaged using a modified susceptibility‐weighted imaging (SWI) sequence. Data quality was first assessed for feasibility of oxygen saturation measurement, and data from five subjects (mean ± std gestational age of 33.7 ± 3.6 weeks) were then chosen for further quantitative analysis. SWI phase in the superior sagittal sinus was used to evaluate oxygen saturation using the principles of MR susceptometry. Systematic error in the measured Yv values was studied through simulations.ResultsSimulations showed that the systematic error in Yv depended upon the assumed angle of the vessel, θ, relative to the main magnetic field and the error in that vessel angle δθ. For the typical vessel angle of θ = 30° encountered in the fetal data analyzed, a δθ as large as ±20° led to an absolute error, δYv, of less than 11%. The measured mean oxygen saturation across the five fetuses was 66% ± 9.4%. This average cerebral venous blood oxygenation value is in close agreement with values in the published literature.ConclusionWe have reported the first in vivo measurement of human fetal cerebral venous oxygen saturation using MRI. J. Magn. Reson. Imaging 2014;39:998–1006. © 2013 Wiley Periodicals, Inc.
DCE‐MRI of the liver: Effect of linear and nonlinear conversions on hepatic perfusion quantification and reproducibility
Authors: Aronhime Shimon , Calcagno Claudia , Jajamovich Guido H. , Dyvorne Hadrien Arezki , Robson Philip , Dieterich Douglas , Isabel Fiel M. , Martel‐Laferriere Valérie , Chatterji Manjil , Rusinek Henry , Taouli Bachir 
Published: November 2013

PurposeTo evaluate the effect of different methods to convert magnetic resonance (MR) signal intensity (SI) to gadolinium concentration ([Gd]) on estimation and reproducibility of model‐free and modeled hepatic perfusion parameters measured with dynamic contrast‐enhanced (DCE)‐MRI.Materials and MethodsIn this Institutional Review Board (IRB)‐approved prospective study, 23 DCE‐MRI examinations of the liver were performed on 17 patients. SI was converted to [Gd] using linearity vs. nonlinearity assumptions (using spoiled gradient recalled echo [SPGR] signal equations). The [Gd] vs. time curves were analyzed using model‐free parameters and a dual‐input single compartment model. Perfusion parameters obtained with the two conversion methods were compared using paired Wilcoxon test. Test–retest and interobserver reproducibility of perfusion parameters were assessed in six patients.ResultsThere were significant differences between the two conversion methods for the following parameters: AUC60 (area under the curve at 60 s, P < 0.001), peak gadolinium concentration (Cpeak, P < 0.001), upslope (P < 0.001), Fp (portal flow, P = 0.04), total hepatic flow (Ft, P = 0.007), and MTT (mean transit time, P < 0.001). Our preliminary results showed acceptable to good reproducibility for all model‐free parameters for both methods (mean coefficient of variation [CV] range, 11.87–23.7%), except for upslope (CV = 37%). Among modeled parameters, DV (distribution volume) had CV <22% with both methods, PV and MTT showed CV <21% and <29% using SPGR equations, respectively. Other modeled parameters had CV >30% with both methods.ConclusionLinearity assumption is acceptable for quantification of model‐free hepatic perfusion parameters while the use of SPGR equations and T1 mapping may be recommended for the quantification of modeled hepatic perfusion parameters. J. Magn. Reson. Imaging 2014;40:90–98 © 2013 Wiley Periodicals, Inc.
Diffusion restriction of the optic nerve in patients with acute visual deficit
Authors: Bender Benjamin , Heine Christian , Danz Sören , Bischof Felix , Reimann Katrin , Bender Miriam , Nägele Thomas , Ernemann Ulrike , Korn Andreas 
Published: November 2013

PurposeDiffusion magnetic resonance imaging (MRI) is commonly used in acute stroke, but not considered diagnostic in ischemic optic neuropathy. This study evaluates the presence of diffusion restriction in patients with acute visual loss by analyzing diffusion‐weighted images (DWI).Materials and MethodsA retrospective study of all patients who clinically presented with acute visual loss and who underwent MRI with DWI between January 2011 and May 2012 were evaluated. Patients with suspected brainstem ischemia were used as a control group. Two neuroradiologists evaluated the DWI for the presence of diffusion restriction within the optic nerve.ResultsIn all, 34 patients with acute visual deficit and 32 controls were evaluated. In all five cases of acute optic ischemia, diffusion restriction with reduced apparent diffusion coefficient was present. In 2/25 patients with clinically defined optic neuritis, a diffusion restriction was present. No diffusion restriction was seen in the control cases or in cases with other causes for an acute visual deficit.ConclusionDWI can identify ischemic lesions of the optic nerve. As in acute multiple sclerosis lesions, optic neuritis can also present in rare circumstances with diffusion restriction and can therefore not be ruled out solely by DWI MRI. J. Magn. Reson. Imaging 2014;40:334–340. © 2013 Wiley Periodicals, Inc.
Decline of fiber tract integrity over the adult age range: A diffusion spectrum imaging study
Authors: Teipel Stefan J. , Lerche Maximilian , Kilimann Ingo , O'Brien Kieran , Grothe Michel , Meyer Peter , Li Xingfeng , Sänger Peter , Hauenstein Karlheinz 
Published: November 2013

PurposeWe applied a novel diffusion spectrum imaging (DSI) acquisition to determine associations between aging and subcortical fiber tract integrity.Materials and MethodsWe studied 35 cognitively healthy subjects (17 women), spanning the adult age range between 23 and 77 years, using anatomical MRI and a novel DSI acquisition scheme at 3 Tesla. The study was approved by the local institutional review board. DSI data were analyzed using tractography and complementary voxel‐based analysis of generalized fractional anisotropy (GFA) maps. We determined the effects of age on generalized fractional anisotropy in selected fiber tracts as well as in a whole brain voxel‐based analysis. For comparison, we studied the effects of age on regional gray and white matter volumes.ResultsWe found a significant reduction in anterior corpus callosum fiber tract integrity with age (P < 0.001), as well as significant GFA reduction throughout the subcortical white matter (P < 0.05, false discovery rate [FDR] corrected). GFA decline was accompanied by significant gray matter atrophy in frontal and temporal association cortex (P < 0.05, FDR corrected).ConclusionOur data suggest that normal aging leads to a regionally specific decline in fiber tract integrity. DSI may become a useful biomarker in healthy and pathological aging. J. Magn. Reson. Imaging 2014;40:348–359. © 2013 Wiley Periodicals, Inc.
Symmetry of the fornix using diffusion tensor imaging
Authors: Sboto‐Frankenstein Uta N. , Lazar Tiffany , Bolster R. Bruce , Thind Sunny , Dreessen de Gervai Patricia , Gruwel Marco L.H. , Smith Stephen D. , Tomanek Boguslaw 
Published: November 2013

PurposeTo: 1) Present fornix tractography in its entirety for 20 healthy individuals to assess variability. 2) Provide individual and groupwise whole tract diffusion parameter symmetry assessments prior to clinical application. 3) Compare whole tract diffusion parameter assessments with tract‐based spatial statistics (TBSS).Materials and MethodsDiffusion tensor imaging (DTI) data were acquired on a 3T Siemens magnetic resonance imaging (MRI) system using a single‐shot spin echo planar imaging (EPI) sequence. Individual fornix tractography was conducted and whole tract diffusion parameter symmetries assessed. Whole tract results were compared with asymmetry contrasts conducted with voxelwise statistical analysis of diffusion parameters using TBSS.ResultsThe fornix tract could be visualized in its entirety including the columns, body, crura, and fimbria. Contrary to the crus and body, there were some tractography inconsistencies of the columns and fimbria across subjects. Although whole tract diffusion parameter asymmetries were nonsignificant, fractional anisotropy (FA) values bordered on statistical significance (P = 0.052). Using TBSS, significant FA asymmetries were identified (P ≤ 0.01, corrected).ConclusionThe findings demonstrate consistency of fornix tractography as well as some variability in the columns and fimbria. While parametric assessment demonstrates diffusion parameter symmetry, permutation‐based TBSS analysis reveals significant FA asymmetries in the crura and fimbriae. J. Magn. Reson. Imaging 2014;40:929–936. © 2013 Wiley Periodicals, Inc.