bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative study on the liquid chromatographic enantioseparation of cyclic β‐amino acids and the related cyclic β‐aminohydroxamic acids on Cinchona alkaloid‐based zwitterionic chiral stationary phases
Authors: Bajtai Attila , Fekete Beáta , Palkó Márta , Fülöp Ferenc , Lindner Wolfgang , Kohout Michal , Ilisz István , Péter Antal 
Published: November 2017

AbstractThe enantiomeric pairs of cis and trans stereoisomers of cyclic β‐aminohydroxamic acids and their related cis and trans cyclic β‐amino acids containing two chiral centers were directly separated on four structurally related chiral stationary phases derived from quinine and quinidine modified with (R,R)‐ and (S,S)‐aminocyclohexanesulfonic acids. Applying these zwitterionic ion‐exchangers as chiral selectors, the effects of the composition of the bulk solvent, the acid and base additives, the structures of the analytes, and temperature on the enantioresolution were investigated. To study the effects of temperature and obtain thermodynamic parameters, experiments were carried out at constant mobile phase compositions in the temperature range 5–50°C. The differences in the changes in standard enthalpy Δ(ΔH°), entropy Δ(ΔS°), and free energy Δ(ΔG°) were calculated from the linear van't Hoff plots derived from the ln α versus 1/T curves in the studied temperature range. Results thus obtained indicated enthalpy‐driven separations in all cases. The sequence of elution of the enantiomers was determined and found to be reversed when ZWIX(–)™ was changed to ZWIX(+)™ or ZWIX(–A) to ZWIX(+A).
N2 production through denitrification and anammox across the continental margin (shelf–slope–rise) of the Ulleung Basin, East Sea
Authors: Na Taehee , Thamdrup Bo , Kim Bomina , Kim Sung‐Han , Vandieken Verona , Kang Dong‐Jin , Hyun Jung‐Ho 
Published: November 2017

AbstractExperimental determinations of nitrogen cycling in deep‐sea sediments are strongly underrepresented in the databases. To investigate the total N2 production rates and relative contribution of denitrification and anaerobic ammonium oxidation (anammox) to benthic fixed‐N removal processes, we conducted 15N isotope‐labeling incubation experiments in whole cores and slurries at nine stations across the continental margin from the shelf (< 200 m) and into the deep (> 2000 m) Ulleung Basin (UB) in the East Sea. The total N2 production rates (anammox plus denitrification) in the center of the UB (8.4 ± 0.2 μmol N m−2 h−1) were high compared to most other deep‐sea sediments at similar water depths. Denitrification rates decreased from the shelf (7.6 ± 0.6 μmol N m−2 h−1) to the basin (3.2 ± 0.4 μmol N m−2 h−1), in proportion to benthic oxygen consumption, whereas anammox rates remained relatively constant or even increased slightly (1.3–4.1 μmol N m−2 h−1). The contribution of anammox to the total N2 production (ra) increased with increasing water depth from the shelf (ca. 17%) to the basin (ca. 56%). The enhanced ra in the center of the UB was associated with an increased availability of nitrite for anammox, which was likely a result of the competitive suppression of denitrification by manganese reduction under MnO2‐rich conditions. Our results emphasize the importance of anammox as a sink for reactive nitrogen in deep‐sea sediments and contribute toward a mechanistic understanding of the factors controlling benthic reactive nitrogen loss in the ocean.
Resonant Robin problems with indefinite and unbounded potential
Authors: Gasiński Leszek , Papageorgiou Nikolaos S. 
Published: November 2017

AbstractWe consider semilinear elliptic problems with an indefinite and unbounded potential and Robin boundary condition. We prove existence and multiplicity theorems when resonance occurs with respect to the principal eigenvalue both from the left and from the right. We also investigate the case where we have resonance with respect to any nonprincipal eigenvalue and prove a multiplicity theorem under general conditions on the reaction term . Our approach uses variational methods, together with truncation and perturbation techniques and Morse theory.
Lorentz estimates for asymptotically regular fully nonlinear parabolic equations
Authors: Zhang Junjie , Zheng Shenzhou 
Published: November 2017

AbstractWe prove a global Lorentz estimate of the Hessian of strong solutions to the Cauchy–Dirichlet problem for a class of fully nonlinear parabolic equations with asymptotically regular nonlinearity over a bounded C1, 1 domain. Here, we mainly assume that the associated regular nonlinearity satisfies uniformly parabolicity and the ‐vanishing condition, and the approach of constructing a regular problem by an appropriate transformation is employed.
Evaluation of the single medial circummuscular perforator DIEP flap: Outcomes and comparison to traditional transmuscular single perforator flap
Authors: Rose Jessica F. , Zavlin Dmitry , Garrett Amanda E. , Chegireddy Vishwanath , Ellsworth Warren A. 
Published: November 2017

IntroductionSuccessful breast reconstruction using deep inferior epigastric perforator (DIEP) flaps depends on optimal perforator choice. Circummuscular wraparound medial perforators allow for no rectus dissection and minimal fascial incisions, often presenting as an ideal option. The aim of our study is to evaluate outcomes of the single medial wraparound perforator flap in comparison to more traditional transmuscular single‐perforator DIEP flaps.Patients and methodsA retrospective chart review was conducted of all DIEP flaps performed by the senior author from 2011 to 2016, yielding 269 flaps on 157 patients. For this study, we included all patients who underwent reconstruction of the breast(s) and possessed circummuscular perforators arising from the DIE vessels. A control group consisted of all consecutive patients with transmuscular one‐perforator DIEP flaps. Patient details and their postoperative outcomes were collected.ResultsIn our study, eight patients (5.1%) were of the medial wraparound variety. Sixteen control patients (10.2%) with similar comorbidities had flaps that were of the more traditional single perforator transmuscular variety. There was a slight trend toward decreased operative time in the medial wraparound group, however, it was not found to be statistically significant (536 ± 81 vs. 572 ± 84 min, P = .377). Complication profiles were similar between groups (25.0 vs. 18.8%, P = .722), with no increased rates of fat necrosis in the wraparound cohort.ConclusionBased on our findings, using a medial wraparound perforator is a safe and reliable option when compared with a single transmuscular perforator DIEP flap. Choosing the wraparound perforator may show benefit as it eliminates muscular dissection and nerve damage, and tends to minimize fascial incision length.
Turbocharged bilateral pedicled DIEP flap for reconstruction of thigh defect without recipient vessels: A case report
Authors: Fernández Garrido Manuel , Pereira Nicolás , López Fernández Susana , Vega Carmen , Masià Jaume 
Published: November 2017

Reconstruction of thigh defects is usually straightforward, but in cases of poor soft tissue quality, free flap reconstruction is not possible due to the absence of recipient vessels. The turbocharge technique may increase the viable, vascularized area of a flap. In this report we present a case of the use of a turbocharged bilateral pedicled DIEP flap for reconstruction of thigh defect without recipient vessels. A 29‐year‐old woman who underwent neoadjuvant chemotherapy plus radiation therapy for a leiomyosarcoma on the left thigh. Six weeks later, complete tumor excision and a femoropopliteal bypass with contralateral saphenous vein was performed. In the following days the wound had dehiscence, infection, necrosis of the surrounding muscles and exposure of femoropopliteal bypass. No recipient vessels were available for free flap and critical limb ischemia due to bypass thrombosis was detected. The reconstruction of a large thigh defect (30 × 12 cm) and the coverage of a femoropopliteal bypass with a turbocharged bilateral pedicled DIEP flap was performed. A flap including the entire infraumbilical tissue was designed and the anastomosis of the proximal stump of the right inferior epigastric vessels with the distal ends of the inferior left epigastric vessels was performed to increase the viable area. The flap survived without any complications during the postoperative period. At 12‐month follow up, coverage was stable with no tumor recurrence. Our result suggests that a turbocharged bilateral pedicled DIEP flap may be an option for reconstructing large tissue defects when no recipient vessels are available for free flap.
Existence of solutions for systems of generalized quasi‐equilibrium problems
Authors: Patriche Monica 
Published: November 2017

In this paper, first of all, we consider a generalized game in choice form with 2 constraints and its corresponding equilibrium in choice. We assert new conditions under which the equilibrium in choice exists. As a consequence, we establish the existence of the equilibrium for generalized abstract economies. Then, we apply the obtained theorems to prove the existence of solutions for systems of quasi‐equilibrium problems. We do this by considering new hypotheses for the properties of the involved correspondences. This approach leads us to results which differ a lot from the ones existing in literature.
Gallic Acid Improves Health‐Associated Biochemical Parameters and Prevents Oxidative Damage of DNA in Type 2 Diabetes Patients: Results of a Placebo‐Controlled Pilot Study
Authors: Ferk Franziska , Kundi Michael , Brath Helmut , Szekeres Thomas , Al‐Serori Halh , Mišík Miroslav , Saiko Philipp , Marculescu Rodrig , Wagner Karl‐Heinz , Knasmueller Siegfried 
Published: November 2017

ScopeOxidative imbalance plays a key role in cancer induction and cardiovascular diseases (CVD) in patients with type 2 diabetes mellitus (T2DM). The aim of this study is to find out if gallic acid (GA) prevents oxidative stress in diabetic patients. Therefore, we investigate its impact on oxidation of DNA bases and on other health‐related macromolecules.Methods and resultsWe perform an intervention study (n = 19) with GA and monitored alterations of the DNA stability in single cell gel electrophoresis (SCGE) assays in lymphocytes. Furthermore, a panel of health‐related biomarkers is measured before and after consumption of GA (15 mg p–1 d–1) for 7 d. Significant reduction of oxidized purines (by 31%, p < 0.001, effect size 0.404) and pyrimidines (by 2%, p < 0.022, effect size 0.089) is observed in SCGE assays. Furthermore, the plasma concentrations of oxidized‐LDL and C‐reactive protein are reduced after the intervention by 24% (p = 0.014, effect size 0.384) and 39% (p < 0.001, effect size 0.686), respectively. No alterations of other biomarkers are found.ConclusionsA small amount of GA (in the range of daily consumption in Central Europe) prevents oxidative DNA damage and reduces markers which reflect inflammation and increased risks of cancer and CVD.
Increased Levels of 27‐Hydroxycholesterol Induced by Dietary Cholesterol in Brain Contribute to Learning and Memory Impairment in Rats
Authors: Zhang Xiaona , Lv Chenyan , An Yu , Liu Quanri , Rong Hongguo , Tao Lingwei , Wang Ying , Wang Yushan , Xiao Rong 
Published: November 2017

ScopeDietary cholesterol has been shown to play a role in the development of Alzheimer's disease (AD). It is proposed that oxysterol especially 27‐hydroxycholesterol (27‐OHC) may play a potential role in β‐amyloid peptides (Aβ) production and accumulation during AD progression.Methods and resultsTo investigate the mechanisms of dietary cholesterol and 27‐OHC on learning and memory impairment, male Sprague‐Dawley rats are fed with cholesterol diet with or without 27‐OHC synthetase inhibitor (anastrozole) injection. The levels of cholesterol, 27‐OHC, 24‐hydroxycholesterol (24S‐OHC), 7α‐hydroxycholesterol, and 7β‐hydroxycholesterol in plasma are determined; apolipoprotein A (ApoA), apolipoprotein B (ApoB), HDL‐cholesterol (HDL‐C), and LDL‐cholesterol (LDL‐C) in plasma or brain; CYP27A1 and CYP7A1 in liver and CYP46A1 and CYP7B1 in brain; cathepsin B, cathepsin D, and acid phosphatase in lysosome; and Aβ1‐40 and Aβ1‐42 in brain. Results show increased levels of 27‐OHC (p < 0.01), LDL‐C (p < 0.01), and ApoB (p < 0.01), and decreased level of HDL‐C (p < 0.05) in plasma, upregulated CYP27A1 (p < 0.01) and CYP7A1 (p < 0.01) expression in liver, altered lysosomal function, and increased level of Aβ in brain (p < 0.05).ConclusionsThis study indicates that the mechanisms of dietary cholesterol on learning and memory impairment may be involved in cholesterol metabolism and lysosome function with the increase of plasma 27‐OHC, thus resulting in Aβ formation and accumulation.
Sensitivity enhancement for detection of hyperpolarized 13C MRI probes with 1H spin coupling introduced by enzymatic transformation in vivo
Authors: von Morze Cornelius , Tropp James , Chen Albert P. , Marco‐Rius Irene , Van Criekinge Mark , Skloss Timothy W. , Mammoli Daniele , Kurhanewicz John , Vigneron Daniel B. , Ohliger Michael A. , Merritt Matthew E. 
Published: November 2017

PurposeAlthough 1H spin coupling is generally avoided in probes for hyperpolarized (HP) 13C MRI, enzymatic transformations of biological interest can introduce large 13C‐1H couplings in vivo. The purpose of this study was to develop and investigate the application of 1H decoupling for enhancing the sensitivity for detection of affected HP 13C metabolic products.MethodsA standalone 1H decoupler system and custom concentric 13C/1H paddle coil setup were integrated with a clinical 3T MRI scanner for in vivo 13C MR studies using HP [2‐13C]dihydroxyacetone, a novel sensor of hepatic energy status. Major 13C‐1H coupling JCH = ∼150 Hz) is introduced after adenosine triphosphate–dependent enzymatic transformation of HP [2‐13C]dihydroxyacetone to [2‐13C]glycerol‐3‐phosphate in vivo. Application of WALTZ‐16 1H decoupling for elimination of large 13C‐1H couplings was first tested in thermally polarized glycerol phantoms and then for in vivo HP MR studies in three rats, scanned both with and without decoupling.ResultsAs configured, 1H‐decoupled 13C MR of thermally polarized glycerol and the HP metabolic product [2‐13C]glycerol‐3‐phosphate was achieved at forward power of approximately 15 W. High‐quality 3‐s dynamic in vivo HP 13C MR scans were acquired with decoupling duty cycle of 5%. Application of 1H decoupling resulted in sensitivity enhancement of 1.7‐fold for detection of metabolic conversion of [2‐13C]dihydroxyacetone to HP [2‐13C]glycerol‐3‐phosphate in vivo.ConclusionsApplication of 1H decoupling provides significant sensitivity enhancement for detection of HP 13C metabolic products with large 1H spin couplings, and is therefore expected to be useful for preclinical and potentially clinical HP 13C MR studies. Magn Reson Med 80:36–41, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Artificial neural networks for stiffness estimation in magnetic resonance elastography
Authors: Murphy Matthew C. , Manduca Armando , Trzasko Joshua D. , Glaser Kevin J. , Huston John , Ehman Richard L. 
Published: November 2017

PurposeTo investigate the feasibility of using artificial neural networks to estimate stiffness from MR elastography (MRE) data.MethodsArtificial neural networks were fit using model‐based training patterns to estimate stiffness from images of displacement using a patch size of ∼1 cm in each dimension. These neural network inversions (NNIs) were then evaluated in a set of simulation experiments designed to investigate the effects of wave interference and noise on NNI accuracy. NNI was also tested in vivo, comparing NNI results against currently used methods.ResultsIn 4 simulation experiments, NNI performed as well or better than direct inversion (DI) for predicting the known stiffness of the data. Summary NNI results were also shown to be significantly correlated with DI results in the liver (R2 = 0.974) and in the brain (R2 = 0.915), and also correlated with established biological effects including fibrosis stage in the liver and age in the brain. Finally, repeatability error was lower in the brain using NNI compared to DI, and voxel‐wise modeling using NNI stiffness maps detected larger effects than using DI maps with similar levels of smoothing.ConclusionArtificial neural networks represent a new approach to inversion of MRE data. Summary results from NNI and DI are highly correlated and both are capable of detecting biologically relevant signals. Preliminary evidence suggests that NNI stiffness estimates may be more resistant to noise than an algebraic DI approach. Taken together, these results merit future investigation into NNIs to improve the estimation of stiffness in small regions. Magn Reson Med 80:351–360, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Template‐based field map prediction for rapid whole brain B0 shimming
Authors: Shi Yuhang , Vannesjo S. Johanna , Miller Karla L. , Clare Stuart 
Published: November 2017

PurposeIn typical MRI protocols, time is spent acquiring a field map to calculate the shim settings for best image quality. We propose a fast template‐based field map prediction method that yields near‐optimal shims without measuring the field.MethodsThe template‐based prediction method uses prior knowledge of the B0 distribution in the human brain, based on a large database of field maps acquired from different subjects, together with subject‐specific structural information from a quick localizer scan. The shimming performance of using the template‐based prediction is evaluated in comparison to a range of potential fast shimming methods.ResultsStatic B0 shimming based on predicted field maps performed almost as well as shimming based on individually measured field maps. In experimental evaluations at 7 T, the proposed approach yielded a residual field standard deviation in the brain of on average 59 Hz, compared with 50 Hz using measured field maps and 176 Hz using no subject‐specific shim.ConclusionsThis work demonstrates that shimming based on predicted field maps is feasible. The field map prediction accuracy could potentially be further improved by generating the template from a subset of subjects, based on parameters such as head rotation and body mass index. Magn Reson Med 80:171–180, 2018. © 2017 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Improved parallel image reconstruction using feature refinement
Authors: Cheng Jing , Jia Sen , Ying Leslie , Liu Yuanyuan , Wang Shanshan , Zhu Yanjie , Li Ye , Zou Chao , Liu Xin , Liang Dong 
Published: November 2017

PurposeThe aim of this study was to develop a novel feature refinement MR reconstruction method from highly undersampled multichannel acquisitions for improving the image quality and preserve more detail information.Theory and MethodsThe feature refinement technique, which uses a feature descriptor to pick up useful features from residual image discarded by sparsity constrains, is applied to preserve the details of the image in compressed sensing and parallel imaging in MRI (CS‐pMRI). The texture descriptor and structure descriptor recognizing different types of features are required for forming the feature descriptor. Feasibility of the feature refinement was validated using three different multicoil reconstruction methods on in vivo data.ResultsExperimental results show that reconstruction methods with feature refinement improve the quality of reconstructed image and restore the image details more accurately than the original methods, which is also verified by the lower values of the root mean square error and high frequency error norm.ConclusionA simple and effective way to preserve more useful detailed information in CS‐pMRI is proposed. This technique can effectively improve the reconstruction quality and has superior performance in terms of detail preservation compared with the original version without feature refinement. Magn Reson Med 80:211–223, 2018. © 2017 International Society for Magnetic Resonance in Medicine.
Aquaporin 4 expression in human skeletal muscle fiber types
Authors: Vizzaccaro Elisa , Terracciano Chiara , Rastelli Emanuele , Massa Roberto 
Published: November 2017

ABSTRACTIntroduction: Aquaporins (AQPs) are a family of transmembrane proteins involved in the maintenance of osmotic gradients. AQP4 is abundant in skeletal muscle, where it seems to be associated with glycolytic metabolism. We investigated the pattern of expression of AQP4 in normal human myofibers relative to the main forms of myosin heavy chain (MHC). Methods: Six normal human muscle biopsies were analyzed by double immunofluorescence for co‐expression of AQP4 and slow or fast MHC. Results: A high percentage (64–99%) of MHC‐fast positive fibers showed immunoreaction for AQP4. Immunoreactivity for AQP4 was also present in MHC‐slow positive fibers, but with a higher variability (5–72%) among biopsies. Discussion: The expression pattern of AQP4 in human myofibers is highly variable among different patients and cannot be predicted for single fibers depending on MHC type expression. Other factors, possibly related to muscle activity, may modulate AQP4 expression. Muscle Nerve 57: 856–859, 2018
Enhanced mesoscale partitioned modelling of heterogeneous masonry structures
Authors: Minga E. , Macorini L. , Izzuddin B. A. 
Published: November 2017

SummaryThis paper presents an accurate and efficient computational strategy for the 3‐dimensional simulation of heterogeneous structures with unreinforced masonry components. A mesoscale modelling approach is employed for the unreinforced masonry parts, whereas other material components are modelled independently with continuous meshes. The generally nonmatching meshes of the distinct domains are coupled with the use of a mesh tying method. The physical interaction between the components is captured with the use of zero‐thickness cohesive interface elements. This strategy enables the optimisation of the individual meshes leading to increased computational efficiency. Furthermore, the elimination of the mesh compatibility requirement allows the 3‐dimensional modelling of complex heterogeneous structures, ensuring accurate representation of each component's nonlinear behaviour and their interaction. Numerical examples, including a comparative analysis on the elastic and nonlinear response of a masonry bridge considering arch‐backfill interaction and the nonlinear simulation of a multileaf wall, are presented to show the unique features of the proposed strategy and its predictive power in comparison with experimental and numerical results found in the literature.
A new strategy for finite‐element analysis of shell structures using trimmed quadrilateral shell meshes: A paving and cutting algorithm and a pentagonal shell element
Authors: Ho‐Nguyen‐Tan Thuan , Kim Hyun‐Gyu 
Published: November 2017

SummaryIn this paper, we present a novel scheme to generate trimmed quadrilateral shell meshes using a paving and cutting algorithm. Paving with well‐shaped quadrilateral shell elements is initiated from a seed element placed in the interior of a geometric surface and proceeds around the boundary of the paved mesh in all directions. The paved all‐quadrilateral mesh covering the entire domain is cut by the boundaries of a geometric surface. Pentagonal shell elements are created by cutting the corners of quadrilateral shell elements at the domain boundaries. Pentagonal shape functions are constructed using Wachspress coordinates, and assumed natural strains in the form of the mixed interpolation of tensorial components approach are employed to avoid the transverse shear locking of pentagonal shell elements. Several numerical examples are investigated to show the effectiveness of the present method.