bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of mesoscale eddies and mean circulation in ventilation of the Southern Ocean
Authors: Kamenkovich Igor , Garraffo Zulema , Pennel Romain , Fine Rana A.
Published: March 2017

This study examines the relative importance of the mean advection and mesoscale currents in the property exchange between the Southern Ocean mixed layer and downstream in the upper 2000 m; this exchange is referred to as ventilation. A new, highly efficient off‐line tracer model employed here uses precalculated velocities to advect dynamically passive tracers. Two idealized tracers are considered: the Boundary Impulse Response (BIR) tracer, which helps to determine the ventilation pathways and time scales, and the Transient Surface Tracer (TST), which is relevant to transient atmospheric tracers. The importance of eddies is isolated by contrasting the control simulation with a simulation without mesoscale currents. The analysis reveals complex three‐dimensional ventilation pathways, controlled by the interplay between the mean advection and eddy‐induced spreading. The mean currents carry the tracers eastward within ACC and contribute to the formation of the Antarctic Intermediate Water (AAIW) in the South Pacific and South Atlantic. The main effect of eddies is to disperse tracers away from the mean pathways, and this dispersion acts to retain the BIR tracer in the Atlantic and Indian sectors and reduce the upstream influence of these regions on the South Pacific. In addition, the eddy‐induced along‐isopycnal spreading within ACC increases the ventilated depth and the inventory of TST. The results can be used to interpret distribution of tracers in the ocean in numerical simulations and observations.
Striations and preferred eddy tracks triggered by topographic steering of the background flow in the eastern South Pacific
Authors: Belmadani Ali , Concha Emilio , Donoso David , Chaigneau Alexis , Colas François , Maximenko Nikolai , Di Lorenzo Emanuele
Published: March 2017

In recent years, persistent quasi‐zonal jets or striations have been ubiquitously detected in the world ocean using satellite and in situ data as well as numerical models. This study aims at determining the role of mesoscale eddies in the generation and persistence of striations off Chile in the eastern South Pacific. A 50 year climatological integration of an eddy‐resolving numerical ocean model is used to assess the long‐term persistence of striations. Automated eddy tracking algorithms are applied to the model outputs and altimetry data. Results reveal that striations coincide with both polarized eddy tracks and the offshore formation of new eddies in the subtropical front and coastal transition zone, without any significant decay over time that discards random eddies as a primary driver of the striations. Localized patches of vortex stretching and relative vorticity advection, alternating meridionally near the eastern edge of the subtropical front, are associated with topographic steering of the background flow in the presence of steep topography, and with baroclinically and barotropically unstable meridional flow. These sinks and sources of vorticity are suggested to generate the banded structure further west, consistently with a β‐plume mechanism. On the other hand, zonal/meridional eddy advection of relative vorticity and the associated Reynolds stress covariance are consistent with eddy deformation over rough topography and participate to sustain the striations in the far field. Shear instability of mean striations is proposed to feedback onto the eddy field, acting to maintain the subtropical front eddy streets and thus the striations.
Response of theKuroshioExtension path state to near‐term global warming in CMIP5 experiments with MIROC4h
Authors: Li Rui , Jing Zhao , Chen Zhaohui , Wu Lixin
Published: March 2017

In this study, responses of the Kuroshio Extension (KE) path state to near‐term (2006–2035) global warming are investigated using a Kuroshio‐resolving atmosphere‐ocean coupled model. Under the representative concentration pathway 4.5 (RCP4.5) forcing, the KE system is intensified and its path state tends to move northward and becomes more stable. It is suggested that the local anticyclonic wind stress anomalies in the KE region favor the spin‐up of the southern recirculation gyre, and the remote effect induced by the anticyclonic wind stress anomalies over the central and eastern midlatitude North Pacific also contributes to the stabilization of the KE system substantially. The dominant role of wind stress forcing on KE variability under near‐term global warming is further confirmed by adopting a linear 1.5 layer reduced‐gravity model forced by wind stress curl field from the present climate model. It is also found that the main contributing longitudinal band for KE index (KEI) moves westward in response to the warmed climate. This results from the northwestward expansion of the large‐scale sea level pressure (SLP) field.
Downstream evolution of the Kuroshio's time‐varying transport and velocity structure
Authors: Andres M. , Mensah V. , Jan S. , Chang M.‐H. , Yang Y.‐J. , Lee C. M. , Ma B. , Sanford T. B.
Published: March 2017

Observations from two companion field programs—Origins of the Kuroshio and Mindanao Current (OKMC) and Observations of Kuroshio Transport Variability (OKTV)—are used here to examine the Kuroshio's temporal and spatial evolution. Kuroshio strength and velocity structure were measured between June 2012 and November 2014 with pressure‐sensor equipped inverted echo sounders (PIESs) and upward‐looking acoustic Doppler current profilers (ADCPs) deployed across the current northeast of Luzon, Philippines, and east of Taiwan with an 8 month overlap in the two arrays' deployment periods. The time‐mean net (i.e., integrated from the surface to the bottom) absolute transport increases downstream from 7.3 Sv (±4.4 Sv standard error) northeast of Luzon to 13.7 Sv (±3.6 Sv) east of Taiwan. The observed downstream increase is consistent with the return flow predicted by the simple Sverdrup relation and the mean wind stress curl field over the North Pacific (despite the complicated bathymetry and gaps along the North Pacific western boundary). Northeast of Luzon, the Kuroshio—bounded by the 0 m s−1 isotach—is shallower than 750 dbar, while east of Taiwan areas of positive flow reach to the seafloor (3000 m). Both arrays indicate a deep counterflow beneath the poleward‐flowing Kuroshio (–10.3 ± 2.3 Sv by Luzon and −12.5 ± 1.2 Sv east of Taiwan). Time‐varying transports and velocities indicate the strong influence at both sections of westward propagating eddies from the ocean interior. Topography associated with the ridges east of Taiwan also influences the mean and time‐varying velocity structure there.
Using a 1‐D model to reproduce the diurnal variability ofSST
Authors: Karagali Ioanna , Høyer Jacob L. , Donlon Craig J.
Published: March 2017

A wide range of applications, from air‐sea interaction studies to fisheries and biological modeling, need accurate, high resolution SST which requires that the diurnal signal is known; for many applications, diurnal estimates are necessary and should be included in blended SST products. A widely preferred approach to bridge the gap between in situ and remotely sensed measurements and obtain diurnal warming estimates at large spatial scales is modeling of the upper ocean temperature. This study uses the one‐dimensional General Ocean Turbulence Model (GOTM) to resolve diurnal signals identified from satellite SSTs and in situ measurements. Focus is given on testing and validation of different parameterizations of the basic physical processes known to influence the generation of a warm surface layer. GOTM is tested and validated using in situ measurements obtained at three locations, two in the Atlantic Ocean and one in the Baltic Sea, where different oceanographic and atmospheric conditions occur, in order to obtain an insight into its general performance. It is found that the model, with a 9 band solar absorption model rather than the standard 2 band scheme, performs well when using 3 hourly NWP forcing fields and is able to resolve daily SST variability seen both from satellite and in situ measurements. As such, and due to its low computational cost, it is proposed as a candidate model for diurnal variability estimates.
Sea‐level rise impacts on the temporal and spatial variability of extreme water levels: A case study for St. Peter‐Ording, Germany
Authors: Santamaria‐Aguilar S. , Arns A. , Vafeidis A. T.
Published: March 2017

Both the temporal and spatial variability of storm surge water level (WL) curves are usually not taken into account in flood risk assessments as observational data are often scarce. In addition, sea‐level rise (SLR) can further affect the variability of WLs. We analyze the temporal and spatial variability of the WL curve of 75 historical storm surge events that have been numerically simulated for St. Peter‐Ording at the German North Sea coast, considering the effects induced by three SLR scenarios (RCP 4.5, RCP 8.5, and a RCP 8.5 high end scenario). We assess potential impacts of these scenarios on two parameters related to flooding: overflow volumes and fullness. Our results indicate that due to both the temporal and spatial variability of those events the resulting overflow volume can be two or even three times greater. We observe a steepening of the WL curve with an increase of the tidal range under the three SLR scenarios, although SLR induced effects are relatively higher for the RCP 4.5. The steepening of the WL curve with SLR produces a reduction of the fullness, but the changes in overflow volumes also depend on the magnitude of the storm surge event.
Validation of sea ice models using an uncertainty‐based distance metric for multiple model variables
Authors: Urrego‐Blanco Jorge R. , Hunke Elizabeth C. , Urban Nathan M. , Jeffery Nicole , Turner Adrian K. , Langenbrunner James R. , Booker Jane M.
Published: March 2017

We implement a variance‐based distance metric (Dn) to objectively assess skill of sea ice models when multiple output variables or uncertainties in both model predictions and observations need to be considered. The metric compares observations and model data pairs on common spatial and temporal grids improving upon highly aggregated metrics (e.g., total sea ice extent or volume) by capturing the spatial character of model skill. The Dn metric is a gamma‐distributed statistic that is more general than the χ2 statistic commonly used to assess model fit, which requires the assumption that the model is unbiased and can only incorporate observational error in the analysis. The Dn statistic does not assume that the model is unbiased, and allows the incorporation of multiple observational data sets for the same variable and simultaneously for different variables, along with different types of variances that can characterize uncertainties in both observations and the model. This approach represents a step to establish a systematic framework for probabilistic validation of sea ice models. The methodology is also useful for model tuning by using the Dn metric as a cost function and incorporating model parametric uncertainty as part of a scheme to optimize model functionality. We apply this approach to evaluate different configurations of the standalone Los Alamos sea ice model (CICE) encompassing the parametric uncertainty in the model, and to find new sets of model configurations that produce better agreement than previous configurations between model and observational estimates of sea ice concentration and thickness.
Near‐shore talik development beneath shallow water in expanding thermokarst lakes, Old Crow Flats, Yukon
Authors: Roy‐Leveillee Pascale , Burn Christopher R.
Published: March 2017

It is generally assumed that permafrost is preserved beneath shallow lakes and ponds in the Western North American Arctic where water depth is less than about two thirds of the late‐winter lake ice thickness. Here we present field observations of talik development beneath water as shallow as 0.2 m despite a lake ice thickness of 1.5 m, in Old Crow Flats (OCF), YT. Conditions leading to the initiation and development of taliks beneath shallow water were investigated with field measurements of shore erosion rates, bathymetry, ice thickness, snow accumulation, and lake bottom temperature near the shores of two expanding lakes in OCF. The sensitivity of talik development to variations in lake bottom thermal regime was then investigated numerically. Where ice reached the lake bottom, talik development was controlled by the ratio of freezing degree days to thawing degree days at the lake bottom (FDDlb/TDDlb). In some cases, spatial variations in on‐ice snow depth had a minimal effect on annual mean lake bottom temperature (Tlb) but caused sufficient variations in FDDlb/TDDlb to influence talik development. Where Tlb was close to but greater than 0°C simulations indicated that the thermal offset allowed permafrost aggradation to occur under certain conditions, resulting in irregular near‐shore talik geometries. The results highlight the sensitivity of permafrost to small changes in lake bottom thermal conditions where the water column freezes through in early winter and indicate the occurrence of permafrost degradation beneath very shallow water in the near‐shore zone of Arctic ponds and lakes.
Evaluating the trade‐offs between ensemble size and ensemble resolution in an ensemble‐variational data assimilation system
Authors: Lei Lili , Whitaker Jeffrey S.
Published: March 2017

The current NCEP operational four‐dimensional ensemble‐variational data assimilation system uses a control forecast at T1534 resolution coupled with an 80 member ensemble at T574 resolution. Given an increase in computing resources, and assuming the control forecast resolution is fixed, would it be better to increase the ensemble size and keep the ensemble resolution the same, or increase the ensemble resolution and keep the ensemble size the same? To answer this question, experiments are conducted at reduced resolutions. Two sets of experiments are conducted which both use approximately four times more computational resources than the control experiment that uses a control forecast at T670 and an 80 member ensemble at T254. One increases the ensemble size to 320 but keeps the ensemble resolution at T254; and the other increases the ensemble resolution to T670 but retains an 80 ensemble size. When ensemble size increases to 320, turning off the static component of the background‐error covariance does not degrade performance. When the data assimilation parameters are tuned for optimal performance, increasing either ensemble size or ensemble resolution can improve the forecast performance. Increasing ensemble resolution is slightly, but significantly better than increasing ensemble size for these experiments, particularly when considering errors at smaller scales. Much of the benefit of increasing ensemble resolution comes about by eliminating the need for a deterministic control forecast and running all of the background forecasts at the same resolution. In this “single‐resolution” mode, the control forecast is replaced by an ensemble average, which reduces small‐scale errors significantly.
Current sheets in comet 67P/Churyumov‐Gerasimenko's coma
Authors: Volwerk M. , Jones G. H. , Broiles T. , Burch J. , Carr C. , Coates A. J. , Cupido E. , Delva M. , Edberg N. J. T. , Eriksson A. , Goetz C. , Goldstein R. , Henri P. , Madanian H. , Nilsson H. , Richter I. , Schwingenschuh K. , Stenberg Wieser G. , Glassmeier K.‐H.
Published: March 2017

The Rosetta Plasma Consortium (RPC) data are used to investigate the presence of current sheets in the coma of comet 67P/Churyumov‐Gerasimenko. The interaction of the interplanetary magnetic field (IMF) transported by the solar wind toward the outgassing comet consists amongst others of mass loading and field line draping near the nucleus. The draped field lines lead to so‐called nested draping because of the constantly changing direction of the IMF. It is shown that the draping pattern is strongly variable over the period of one month. Nested draping results in neighbouring regions with oppositely directed magnetic fields, which are separated by current sheets. Selected events on 5 and 6 June 2015 are studied, which show that there are strong rotations of the magnetic field with associated current sheets that have strengths from several tens up to hundreds of nA/m2. Not all discussed current sheets show the characteristic peak in plasma density at the centre of the sheet, which might be related to the presence of a guide field. There is no evidence for different kinds of plasmas on either side of a current sheet, and no strongly accelerated ions have been observed which could have been an indication of magnetic reconnection in the current sheets.
Simultaneous observations of traveling convection vortices: Ionosphere‐thermosphere coupling
Authors: Kim Hyomin , Lessard Marc R. , Jones Sarah L. , Lynch Kristina A. , Fernandes Philip A. , Aruliah Anasuya L. , Engebretson Mark J. , Moen Jøran I. , Oksavik Kjellmar , Yahnin Alexander G. , Yeoman Timothy K.
Published: March 2017

We present simultaneous observations of magnetosphere‐ionosphere‐thermosphere coupling over Svalbard during a traveling convection vortex (TCV) event. Various spaceborne and ground‐based instruments made coordinated measurements, including magnetometers, particle detectors, an all‐sky camera, European Incoherent Scatter (EISCAT) Svalbard Radar, Super Dual Auroral Radar Network (SuperDARN), and SCANning Doppler Imager (SCANDI). The instruments recorded TCVs associated with a sudden change in solar wind dynamic pressure. The data display typical features of TCVs including vortical ionospheric convection patterns seen by the ground magnetometers and SuperDARN radars and auroral precipitation near the cusp observed by the all‐sky camera. Simultaneously, electron and ion temperature enhancements with corresponding density increase from soft precipitation are also observed by the EISCAT Svalbard Radar. The ground magnetometers also detected electromagnetic ion cyclotron waves at the approximate time of the TCV arrival. This implies that they were generated by a temperature anisotropy resulting from a compression on the dayside magnetosphere. SCANDI data show a divergence in thermospheric winds during the TCVs, presumably due to thermospheric heating associated with the current closure linked to a field‐aligned current system generated by the TCVs. We conclude that solar wind pressure impulse‐related transient phenomena can affect even the upper atmospheric dynamics via current systems established by a magnetosphere‐ionosphere‐thermosphere coupling process.
Family history of cardiovascular disease and parental lifestyle behaviors are associated with offspring cardiovascular disease risk markers in childhood
Authors: Silva Danilo R. , Werneck André O. , Collings Paul J. , Fernandes Rômulo A. , Barbosa Décio S. , Ronque Enio R. V. , Sardinha Luís B. , Cyrino Edilson S.
Published: March 2017

INTRODUCTION

Cardiovascular disease risk markers have become more prevalent in childhood. To provide increased understanding of the etiology of this public health issue, we investigated associations between family characteristics with cardiovascular disease risk markers in adolescents from a developing nation.

METHODS

In this cross‐sectional study data for fasting glucose, lipoproteins (LDL‐C and HDL‐C), triglycerides, and total cholesterol were collected from 991 adolescents aged 10–17 who were recruited from public schools in Londrina city, Southern Brazil. Family history of cardiovascular disease and parental engagement in risk behavior (alcohol consumption and tobacco smoking) were collected using a self‐reported parental questionnaire. Socioeconomic status, adolescent physical activity (estimated by Baecke questionnaire), self‐reported tobacco and alcohol intake, and somatic maturation (age at peak height velocity) were used as covariates. Logistic regression was used for the main analyses.

RESULTS

Independent of adolescent lifestyle behaviors, associations (ORadj [95% CI]) were found between: (1) paternal family history of cardiovascular disease with increased likelihood of high adolescent offspring BMI (1.53 [1.01 to 2.32]) and high triglycerides (2.93 [1.04 to 8.27]); (2) maternal family history of cardiovascular disease with heightened odds of high adolescent offspring triglycerides (2.84 [1.02 to 7.91]); (3) maternal cardiovascular disease with higher odds of high fasting glucose (2.16 [1.13 to 4.14]), and (4) maternal smoking with increased odds of high LDL‐C (1.78 [1.14 to 2.79]) and high total cholesterol (1.77 [1.01 to 3.10]) in adolescent offspring.

CONCLUSION

Family history of cardiovascular disease and maternal tobacco smoking are related to increased cardiovascular risk in adolescents, potentially independent of their own lifestyle behaviors.
Solid–solid phase‐change materials based on hyperbranched polyurethane for thermal energy storage
Authors: Du Xiaosheng , Wang Haibo , Wu Yan , Du Zongliang , Cheng Xu
Published: March 2017

A hyperbranched polyol (HBP) was synthesized with poly(ethylene glycol) (PEG) as the core molecule and 2,2‐bis(hydroxymethyl) propionic acid as the chain extender. Then, a series of hyperbranched polyurethane phase‐change materials (HP‐PCMs) with different crosslinking densities was synthesized with isophorone diisocyanate and HBP as a molecular skeleton and PEG 6000 as a phase‐change ingredient. 1H‐NMR, gel permeation chromatography, and Fourier transform infrared spectroscopy confirmed the successful synthesis of the HBP and HP‐PCMs. The polarization optical microscopy and wide‐angle X‐ray diffraction results show that the HP‐PCM exhibited good crystallization properties, but the crystallinity was lower than that of PEG 6000. The analysis results from differential scanning calorimetry indicated that the HP‐PCMs were typical solid–solid phase‐change materials with suitable phase‐transition temperatures. In addition, HP‐PCM‐3, with an appropriate degree of hyperbranched structure, possessed the highest thermal transition enthalpy of 123.5 J/g. Moreover, thermal cycling testing and thermogravimetric analysis showed that the HP‐PCMs exhibited good thermal reliability and stability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45014.
Polypropylene‐based composites reinforced with textile wastes
Authors: Araújo Rafael S. , Rezende Claudinei C. , Marques Maria F. V , Ferreira Leonardo C. , Russo Pietro , Emanuela Errico Maria , Avolio Roberto , Avella Maurizio , Gentile Gennaro
Published: March 2017

The present work describes the preparation of polypropylene composites reinforced with cotton fibers, which were obtained from textile waste. The cellulosic fibers were bleached and then chemically modified on the surface using acetylation or silanization methods. Fourier transform infrared spectroscopy analysis and energy dispersive X‐ray spectroscopy confirmed the efficiency of both treatments. Results of thermal degradation by thermogravimetric analysis (TGA) of treated fibers indicated that the acetylated ones decreased thermal stability while the silanized fibers increased this property. The influence of the chemical modifications and fibers content in polypropylene‐based composites was studied by thermomechanical and mechanical properties (dynamic mechanical analysis and tensile tests) and thermal analyses (TGA and differential scanning calorimetry). The results showed that the addition of the obtained cellulose fibers in polypropylene caused increase of storage and Young's moduli, along with stress at break. Moreover, scanning electronic microscopy micrographs of cryofractured surfaces revealed stronger adhesion between fiber and matrix in the composites reinforced with the modified fibers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45060.
A thermomechanical study on selective dispersion and different loading of graphene oxide in polypropylene/polycarbonate blends
Authors: Tiwari Santosh K. , Oraon Ramesh , De Adhikari Amrita , Nayak Ganesh Chandra
Published: March 2017

Carbon nanofiller reinforced polymeric materials offer the opportunity to obtain materials with desired properties. In the present study, effects of different loading of graphene oxide (GO) on the compatibility, thermomechanical, and morphological properties of incompatible polypropylene (PP)/polycarbonate (PC) polymer blends were investigated. The neat blend and blend nanocomposites were prepared by using a twin‐screw extruder under controlled shear pressure to explore the role of GO on thermomechanical properties of blends. Fourier transform infrared analysis showed the presence of GO in PC phase which was further confirmed by differential scanning calorimetry and morphological analysis. It was observed that up to loading of 0.5%, GO preferable dispersed in only PC phase and then dispersed in both PP and PC phase with further increase in GO loading due to increase in viscosity of PC phase. Field emission scanning electron microscopy investigation of PNCs showed the coalescence of PC phase with increase of GO loading. Tensile analysis confirmed that 1% of GO loading produced highest reinforcement in thermomechanical properties and further increase of GO loading deteriorate the mechanical properties. Dynamic mechanical analysis also showed high storage modulus for 1% loading. Thermal stability of 1% GO loaded nanocomposite was found to be higher than other blend nanocomposites. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45062.
The urinary 1H‐NMR metabolomics profile of an italian autistic children population and their unaffected siblings
Authors: Lussu Milena , Noto Antonio , Masili Alice , Rinaldi Andrea C. , Dessì Angelica , De Angelis Maria , De Giacomo Andrea , Fanos Vassilios , Atzori Luigi , Francavilla Ruggiero
Published: March 2017

Autism spectrum disorders (ASD) make a dishomogeneous group of psychiatric diseases having either genetic and environmental components, including changes of the microbiota. The rate of diagnosis, based on a series of psychological tests and observed behavior, dramatically increased in the past few decades. Currently, no biological markers are available and the pathogenesis is not defined. The purpose of this study was to evaluate the potential use of 1H‐NMR metabolomics to analyze the global biochemical signature of ASD patients (n = 21) and controls (n = 21), these being siblings of autistic patients. A multivariate model has been used to extrapolate the variables of importance. The discriminating urinary metabolites were identified; in particular, significantly increased levels of hippurate, glycine, creatine, tryptophan, and d‐threitol and decreased concentrations of glutamate, creatinine, lactate, valine, betaine, and taurine were observed in ASD patients. Based on the identified discriminant metabolites, the attention was focused on two possible mechanisms that could be involved in ASD: oxidative stress conditions and gut microflora modifications. In conclusion, nuclear magnetic resonance‐based metabolomics analysis of the urine seems to have the potential for the identification of a metabolic fingerprint of ASD phenotypes and appears to be suitable for further investigation of the disease mechanisms. Autism Res 2017. © 2017 International Society for Autism Research, Wiley Periodicals, Inc. Autism Res 2017, 10: 1058–1066. © 2017 International Society for Autism Research, Wiley Periodicals, Inc.
Influence of the pharmacokinetic profile on the plasma glucose lowering effect of the PPARγ agonist pioglitazone in Wistar fatty rats
Authors: Goto Akihiko , Tagawa Yoshihiko , Kimura Yoshiaki , Kogame Akifumi , Moriya Yuu , Amano Nobuyuki
Published: March 2017

Although the mechanism of action for peroxisome proliferator‐activated receptor gamma (PPARγ) agonists has been extensively explored, the impact of the pharmacokinetic (PK) profile on the pharmacodynamic (PD) effects of PPARγ agonists has not been elucidated in detail. The importance of the PK profile of PPARγ agonist was evaluated for its PD effect based on population PK/PD analysis. Pioglitazone hydrochloride, the PPARγ agonist, was administered orally to Wistar fatty rats once a day (q.d.) or once every other day (q.2d.) as double the amount for the q.d. treatment. The plasma glucose lowering effect was selected as a surrogate PD effect for an anti‐diabetic effect. The model fitting was conducted using the non‐linear mixed effect modeling (NONMEM) method. The indirect response model described well the plasma glucose concentration–time profile. The q.d. treatment showed a stronger impact on the plasma glucose lowering effect than did the q.2d. treatment. The results of PK/PD modeling suggested that the sensitivity (i.e. EC50) between each group was comparable. On the other hand, the time above the effective concentration in the q.d. treatment group was longer than that in the q.2d. treatment group. The simulation of various dose regimens suggested that the much longer exposure duration within the effective level showed a stronger plasma glucose lowering effect, even with identical exposure to pioglitazone in the plasma. The PK/PD analysis clarified that the PK profile affected the pharmacological response and that continuous exposure at an appropriate effective level would be efficient for the anti‐diabetic effect of the PPARγ agonist.
Flavonoids from Potentilla parvifolia Fisch. and Their Neuroprotective Effects in Human Neuroblastoma SH‐SY5Y Cells in vitro
Authors: Yuan Zhenzhen , Luan Guangxiang , Wang Zhenhua , Hao Xueyan , Li Ji , Suo Yourui , Li Gang , Wang Honglun
Published: March 2017

Potentilla parvifolia Fisch. (Rosaceae) is a traditional medicinal plant in P. R. China. In this study, seven flavonoids, ayanin (1), tricin (2), quercetin (3), tiliroside (4), miquelianin (5), isoquercitrin (6), and astragalin (7), were separated and purified from ethyl acetate extractive fractions from ethanol extracts of P. parvifolia using a combination of sevaral chromatographic methods. The human neuroblastoma SH‐SY5Y cells were differentiated with all trans‐retinoic acid and treated with okadaic acid to induce tau protein phosphorylation and synaptic atrophy, which could establish an Alzheimer's disease cell model. The neuroprotective effects of these flavonoids in cellular were evaluated in vitro by this cell model. Results from the Western blot and morphology analysis suggested that compounds 3 and 4 had the better neuroprotective effects.
Antioxidant Capacity, Phenolic Constituents and Toxicity of Hot Water Extract from Red Maple Buds
Authors: Meda Naamwin R. , Poubelle Patrice E. , Stevanovic Tatjana
Published: March 2017

The present study reports, for the first time, the results of the antioxidant capacity and the phenolic composition of a hot water extract from red maple buds (RMB), as well as its safety. In this regard and comparatively to antioxidant standards, this extract exhibits a significant antiradical capacity when tested by 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH·) and anion superoxide trapping assays. High‐resolution mass spectrometric and nuclear magnetic resonance analyses permitted to determine for the first time, in red maple species, cyanidin‐3‐O‐glucoside, quercetin‐3‐O‐galactoside, quercetin‐3‐O‐arabinoside, and quercetin. Also, the quantification of individual phenolics by high‐performance liquid chromatography method revealed that ginnalin A at 117.0 mg/g is the major compound of RMB hot water extract. Finally, using flow cytometry evaluation, the extract of RMB was determined to have no toxicity neither to cause significant modification of apoptosis process, up to concentration of 100 μg/ml, on human peripheral blood neutrophils. These results allow anticipating various fields of application of RMB water extract.
Effect of preparation method of active component on the cycling performance of sorbents for hot coal gas clean‐up
Authors: Feng Yu , Li Yang , Shi Lei , Wu Mengmeng , Mi Jie
Published: March 2017

High temperature gas desulphurization is an efficient environmentally friendly process for high efficiency technologies with syngas clean‐up. The present study investigated the impact of preparation methods on the behaviours of ZnO/red clay sorbent. The sorbents were prepared by the homogeneous precipitation method and solid‐state method, respectively. The surface and structural properties of the sorbents were characterized by thermogravimetric, X‐ray diffraction, X‐ray photoelectron spectroscopy, scanning electron microscope‐elemental mapping, and N2 adsorption analysis. Successive desulphurization‐regeneration cycles were conducted to investigate the reusability of the sorbents. After four cycles of desulphurization‐regeneration experiments, the breakthrough times of the two kinds of regenerated sorbents plunged 18.17 % and 23.26 %, respectively. Attritions of sorbents have not been observed, meaning the regenerated sorbents still maintain a high mechanical strength. The sorbents prepared through the homogeneous precipitation method were found to exhibit a longer breakthrough time much greater than those prepared by the solid‐state method. The characterization data indicate that the homogeneous precipitation method results in more uniform distribution of active component sorbent with smaller particle size and better pore structure, which favours the chemical reaction and mass transfer processes.
Phase‐field boundary conditions for the voxel finite cell method: Surface‐free stress analysis of CT‐based bone structures
Authors: Nguyen Lam , Stoter Stein , Baum Thomas , Kirschke Jan , Ruess Martin , Yosibash Zohar , Schillinger Dominik
Published: March 2017

The voxel finite cell method uses unfitted finite element meshes and voxel quadrature rules to seamlessly transfer computed tomography data into patient‐specific bone discretizations. The method, however, still requires the explicit parametrization of boundary surfaces to impose traction and displacement boundary conditions, which constitutes a potential roadblock to automation. We explore a phase‐field–based formulation for imposing traction and displacement constraints in a diffuse sense. Its essential component is a diffuse geometry model generated from metastable phase‐field solutions of the Allen‐Cahn problem that assumes the imaging data as initial condition. Phase‐field approximations of the boundary and its gradient are then used to transfer all boundary terms in the variational formulation into volumetric terms. We show that in the context of the voxel finite cell method, diffuse boundary conditions achieve the same accuracy as boundary conditions defined over explicit sharp surfaces, if the inherent length scales, ie, the interface width of the phase field, the voxel spacing, and the mesh size, are properly related. We demonstrate the flexibility of the new method by analyzing stresses in a human femur and a vertebral body.
Pointwise Estimates and Regularity in Geometric Optics and Other Generated Jacobian Equations
Authors: Guillen Nestor , Kitagawa Jun
Published: March 2017

The study of reflector surfaces in geometric optics necessitates the analysis of certain nonlinear equations of Monge‐Ampère type known as generated Jacobian equations. This class of equations, whose general existence theory has been recently developed by Trudinger, goes beyond the framework of optimal transport. We obtain pointwise estimates for weak solutions of such equations under minimal structural and regularity assumptions, covering situations analogous to those of costs satisfying the A3‐weak condition introduced by Ma, Trudinger, and Wang in optimal transport. These estimates are used to develop a C1,α regularity theory for weak solutions of Aleksandrov type. The results are new even for all known near‐field reflector/refractor models, including the point source and parallel beam reflectors, and are applicable to problems in other areas of geometry, such as the generalized Minkowski problem.© 2017 Wiley Periodicals, Inc.
The Role of Anion Adsorption in the Effect of Electrode Potential on Surface Plasmon Resonance Response
Authors: Laurinavichyute Veronika K. , Nizamov Shavkat , Mirsky Vladimir M.
Published: March 2017

Surface plasmon resonance, being widely used in bioanalytics and biotechnology, is influenced by the electrical potential of the resonant gold layer. To evaluate the mechanism of this effect, we have studied it in solutions of various inorganic electrolytes. The magnitude of the effect decreases according to the series: KBr>KCl>KF>NaClO4. The data were treated by using different models of the interface. A quantitative description was obtained for the model, which takes into account the local dielectric function of gold being affected by the free electron charge, diffuse ionic layer near the gold/water interface, and specific adsorption of halides to the gold surface with partial charge transfer. Taking into account that most biological experiments are performed in chloride‐containing solutions, detailed analysis of the model at these conditions was performed. The results indicate that the chloride adsorption is the main mechanism for the influence of potential on the surface plasmon resonance. The dependencies of surface concentration and residual charge of chloride on the applied potential were determined.
Hydroxide Self‐Feeding High‐Temperature Alkaline Direct Formate Fuel Cells
Authors: Li Yinshi , Sun Xianda , Feng Ying
Published: March 2017

Conventionally, both the thermal degradation of the anion‐exchange membrane and the requirement of additional hydroxide for fuel oxidation reaction hinder the development of the high‐temperature alkaline direct liquid fuel cells. The present work addresses these two issues by reporting a polybenzimidazole‐membrane‐based direct formate fuel cell (DFFC). Theoretically, the cell voltage of the high‐temperature alkaline DFFC can be as high as 1.45 V at 90 °C. It has been demonstrated that a proof‐of‐concept alkaline DFFC without adding additional hydroxide yields a peak power density of 20.9 mW cm−2, an order of magnitude higher than both alkaline direct ethanol fuel cells and alkaline direct methanol fuel cells, mainly because the hydrolysis of formate provides enough OH− ions for formate oxidation reaction. It was also found that this hydroxide self‐feeding high‐temperature alkaline DFFC shows a stable 100 min constant‐current discharge at 90 °C, proving the conceptual feasibility.
Identification and characterization of novel long‐term metabolites of oxymesterone and mesterolone in human urine by application of selected reaction monitoring GC‐CI‐MS/MS
Authors: Polet Michael , Van Gansbeke Wim , Geldof Lore , Deventer Koen , Van Eenoo Peter
Published: March 2017

The search for metabolites with longer detection times remains an important task in, for example, toxicology and doping control. The impact of these long‐term metabolites is highlighted by the high number of positive cases after reanalysis of samples that were stored for several years, e.g. samples of previous Olympic Games. A substantial number of previously alleged negative samples have now been declared positive due to the detection of various long‐term steroid metabolites the existence of which was unknown during the Olympic Games of 2008 and 2012.

In this work, the metabolism of oxymesterone and mesterolone, two anabolic androgenic steroids (AAS), was investigated by application of a selected reaction monitoring gas chromatography–chemical ionization–triple quadrupole mass spectrometry (GC‐CI‐MS/MS) protocol for metabolite detection and identification. Correlations between AAS structure and GC‐CI‐MS/MS fragmentation behaviour enabled the search for previously unknown but expected AAS metabolites by selection of theoretical transitions for expected metabolites. Use of different hydrolysis protocols allowed for evaluation of the detection window of both phase I and phase II metabolites.

For oxymesterone, a new metabolite, 18‐nor‐17β‐hydroxymethyl‐17α‐methyl‐4‐hydroxy‐androst‐4,13‐diene‐3‐one, was identified. It was detectable up to 46 days by using GC‐CI‐MS/MS, whereas with a traditional screening (detection of metabolite 17‐epioxymesterone with electron ionization GC‐MS/MS) oxymesterone administration was only detectable for 3.5 days.

A new metabolite was also found for mesterolone. It was identified as 1α‐methyl‐5α‐androstan‐3,6,16‐triol‐17‐one and its sulfate form after hydrolysis with Helix pomatia resulted in a prolonged detection time (up to 15 days) for mesterolone abuse. Copyright © 2017 John Wiley & Sons, Ltd.
Distribution pattern of ethyl glucuronide and caffeine concentrations over the scalp of a single person in a forensic context
Authors: Meier Ulf , Briellmann Thomas , Scheurer Eva , Dussy Franz
Published: March 2017

The distribution of analyte concentrations in hair across the scalp has not been thoroughly investigated. Differences in concentrations depending on sampling location are problematic, especially when measuring a second strand to confirm the result of the first measurement. Aiming at a better understanding of the concentration differences, the distribution of ethyl glucuronide (EtG) and caffeine concentrations in hair across the entire head of one test subject was investigated by dividing the scalp completely into regions of ca 2 cm × 2 cm area, yielding a total of 104 samples. For the quantification of EtG, a novel LC–MS3/MRM method was developed and validated with a limit of detection and limit of quantification of 2 and 4 pg/mg, respectively. Large variations of the concentration across the head were found, with factors of ca 3.0 and 10.6 for EtG and caffeine, respectively. These differences could not be attributed to measurement error alone. The concentrations were projected onto the subject's head, and concentration patterns were identified for EtG and caffeine. When examining multiple strands from within one 2 cm × 2 cm sampling area, the strands showed similar concentrations. Segmental analysis of selected 3 cm strands showed decreasing concentrations of EtG and caffeine from proximal to distal end, possibly due to wash‐out of the analytes. Copyright © 2017 John Wiley & Sons, Ltd.
Two complementary methods to control gonadotropin‐releasing hormone vaccination (Improvac®) misuse in horseracing: Enzyme‐linked immunosorbent assay test in plasma and steroidomics in urine
Authors: Bailly‐Chouriberry Ludovic , Loup Benoit , Popot Marie‐Agnès , Dreau Marie‐Laure , Garcia Patrice , Bruyas Jean‐François , Bonnaire Yves
Published: March 2017

Since the availability on the European market of the vaccine Improvac® dedicated to male pig immunological castration, the risk of misuse of this product in horses is now considered as a threat for the horseracing industry. Immunological castration is not allowed by the racing codes (immune system, Article 6). Indeed, this vaccination against the hypothalamic hormone luteinizing hormone‐releasing hormone or gonadotropin‐releasing hormone (GnRH) will prevent the release from the anterior pituitary of luteinizing hormone and follicle stimulating hormone, which are required for the development and activity of gonads in males (testes) and female (ovaries) and therefore all their subsequent physiological functions. This treatment will induce a strong hormonal variation resulting in a behaviour modification of the animals.

In this work, four male standardbreds treated with Improvac® vaccine (two intramuscular injections within 4 weeks) were studied. Monitoring of the total scrotal width showed a decrease of the scrotum size (37%) and production of anti‐GnRH antibodies was detected up to 200 days after the first injection. Anti‐GnRH antibodies were detected in plasma after caprylic acid precipitation followed by an enzyme‐linked immunosorbent assay (ELISA) as a rapid and efficient screening method applicable to routine analysis. These results were correlated to a switch of the sexual status from male group to gelding/female group obtained by a steroidomic approach with urine based on ten endogenous compounds. Copyright © 2017 John Wiley & Sons, Ltd.
Microvesicles released by apoptotic human neutrophils suppress proliferation and IL‐2/IL‐2 receptor expression of resting T helper cells
Authors: Shen Guifen , Krienke Stefan , Schiller Petra , Nießen Anna , Neu Susanne , Eckstein Volker , Schiller Martin , Lorenz Hanns‐Martin , Tykocinski Lars‐Oliver
Published: March 2017

Membrane‐coated microvesicles (MVs) have been identified as important mediators in intercellular communication. During the process of apoptosis, dying cells dynamically release MVs. Neutrophils are the most abundant type of leukocytes in the circulation. Due to their very short lifespan, it is likely that they are the source of large amounts of apoptotic cell‐derived MVs. Here, we show that MVs released by apoptotic human polymorphonuclear neutrophils (apoPMN‐MVs), but not the apoptotic neutrophils themselves, selectively suppress the proliferation of CD25 (IL‐2Rα)neg CD127 (IL‐7Rα)pos Th cells in a dose‐dependent manner. In contrast, the proliferation of total T cells is not affected by MVs. Importantly, apoPMN‐MVs suppress the secretion of IL‐2 as well as the expression of and signaling via the IL‐2 receptor (IL‐2R) by CD25negCD127pos Th cells. Addition of IL‐7 strongly reduced the suppression of T‐cell proliferation by MVs and the addition of IL‐2 completely abrogated the suppressive effect. Thus, apoPMN‐MVs suppressed a subset of Th cells by downregulating IL‐2 and IL‐2R expression and signaling. This may represent an important mechanism to prevent the activation and expansion of resting T cells in the absence of sufficient cytokine stimulation, and thereby maintaining immune tolerance.
Preparation of an MCM‐22/Hydrotalcite Framework Composite and Its Catalytic Application
Authors: Baskaran Thangaraj , Christopher Jayaraj , Mariyaselvakumar Mariyamuthu , Sakthivel Ayyamperumal
Published: March 2017

A composite material (MAMCM), possessing both a layered cationic MgAl‐hydrotalcite (MA‐HT) and an anionic MCM‐22 framework, was prepared by a simple coprecipitation method. The resulting composite material has features of both MCM‐22 and the HT layered framework, as shown by powder XRD, FTIR, 29Si and 27Al‐MAS NMR spectroscopy, and SEM studies. Electron microscopy revealed that the layer sheets are arranged in a spherical morphology. The composite material was utilized for the vapor‐phase alkylation of toluene. The MAMCM material showed better toluene conversion than MCM‐22 and MA‐HT materials.
Hexadecanuclear Copper Monothiocarbonates: An Emissive Cluster Building Block
Authors: Gupta Arvind K. , Kishore Pilli V. V. N. , Liao Jian‐Hong , Chen Yuan‐Jang , Liu C. W.
Published: March 2017

A novel CuI cluster, Cu16L16·2CH3COCH3 (1), derived from a cyclohexylmonothiocarbonate ligand (L) was synthesized and structurally characterized. Coordinated‐solvent‐replacement reactions of 1 with various N‐donor ligands to provide 2–5 were demonstrated. Clusters 1–3 and 5 display photoluminescence, whereas 4 is nonemissive. It appears that the emission characteristic of 1 can be tuned by ancillary N‐donor ligands.