bluuebunny/crossref_metadata_2025 huggingface dataset:
Seasonal evolution of the QBO‐induced wave forcing and circulation anomalies in the northern winter stratosphere
Authors: White Ian P. , Lu Hua , Mitchell Nicholas J.
Published: August 2016

Diagnostics of wave‐mean‐flow and wave‐wave interactions in isentropic coordinates are analyzed regarding the mechanisms that govern the Holton‐Tan effect (HTE), whereby the tropical quasi‐biennial oscillation (QBO) modulates the northern winter stratospheric polar vortex. We find a clear seasonal evolution of a QBO modulation of Rossby waves and linear and nonlinear wave interactions, along with multiple mechanisms at work. In early winter, when the lower stratospheric QBO is easterly, there is enhanced upward stationary planetary‐wave activity in the subtropical to midlatitude lower stratosphere. These upward‐propagating waves are first refracted toward the zero‐wind line. Approximately 1 month later, poleward‐propagating wave anomalies appear at midlatitudes as a result of nonlinear wave interactions. The enhanced upward wave propagation appears to be due to a combination of the QBO influence on the latitudinal location of the zero‐wind line and the increased midlatitude baroclinicity associated with the QBO‐induced meridional circulation. This is further aided by a gradual poleward shift over the winter of the middle‐stratospheric waveguide, refracting waves poleward. The associated wave breaking weakens the polar vortex and drives a stronger meridional circulation throughout the lower to middle stratosphere, contributing to the high‐latitude warming. It is additionally found that in late winter, the modified high‐latitude waveguide associated with the weaker polar vortex, consequently reduces upward‐propagating transient planetary waves at high latitudes while simultaneously enhancing upward‐propagating synoptic waves at midlatitudes. This highlights the need to view the HTE and its mechanisms as an evolving phenomenon throughout the winter.
Investigation into the impact of storms on sustaining summer primary productivity in the Sub‐Antarctic Ocean
Authors: Nicholson Sarah‐Anne , Lévy Marina , Llort Joan , Swart Sebastiaan , Monteiro Pedro M. S.
Published: August 2016

In the Sub‐Antarctic Ocean elevated phytoplankton biomass persists through summer at a time when productivity is expected to be low due to iron limitation. Biological iron recycling has been shown to support summer biomass. In addition, we investigate an iron supply mechanism previously unaccounted for in iron budget studies. Using a 1‐D biogeochemical model, we show how storm‐driven mixing provides relief from phytoplankton iron limitation through the entrainment of iron beneath the productive layer. This effect is significant when a mixing transition layer of strong diffusivities (kz > 10−4 m2 s−1) is present beneath the surface‐mixing layer. Such subsurface mixing has been shown to arise from interactions between turbulent ocean dynamics and storm‐driven inertial motions. The addition of intraseasonal mixing yielded increases of up to 60% in summer primary production. These results stress the need to acquire observations of subsurface mixing and to develop the appropriate parameterizations of such phenomena for ocean‐biogeochemical models.
Swelling‐induced changes in coal microstructure due to supercritical CO2 injection
Authors: Zhang Yihuai , Lebedev Maxim , Sarmadivaleh Mohammad , Barifcani Ahmed , Iglauer Stefan
Published: August 2016

Enhanced coalbed methane recovery and CO2 geostorage in coal seams are severely limited by permeability decrease caused by CO2 injection and associated coal matrix swelling. Typically, it is assumed that matrix swelling leads to coal cleat closure, and as a consequence, permeability is reduced. However, this assumption has not yet been directly observed. Using a novel in situ reservoir condition X‐ray microcomputed tomography flooding apparatus, for the first time we observed such microcleat closure induced by supercritical CO2 flooding in situ. Furthermore, fracturing of the mineral phase (embedded in the coal) was observed; this fracturing was induced by the internal swelling stress. We conclude that coal permeability is drastically reduced by cleat closure, which again is caused by coal matrix swelling, which again is caused by flooding with supercritical CO2.
Spectral characteristics of steady quiet‐time EMIC waves observed at geosynchronous orbit
Authors: Kim Khan‐Hyuk , Park Jong‐Sun , Omura Yoshiharu , Shiokawa Kazuo , Lee Dong‐Hun , Kim Gi‐Jeong , Jin Ho , Lee Ensang , Kwon Hyuck‐Jin
Published: August 2016

We have studied the spectral properties of quiet‐time electromagnetic ion cyclotron (EMIC) waves following a steady quiet condition, which is defined with Kp values ≤1 during 12 h, using GOES 10, 11, and 12 magnetometer data for solar minimum years 2007–2008. We identified 6584 steady quiet‐time EMIC wave samples using a semiautomated procedure. Approximately 82% of the samples were observed in the morning‐to‐early afternoon sector (0700–1500 magnetic local time) with a maximum occurrence near noon, and their peak frequencies were mostly in the He band. We found that the occurrence rate of steady quiet‐time EMIC waves is higher than that of EMIC waves for all or quiet geomagnetic conditions (Dst > 0 nT or AE < 100 nT) reported in previous studies by a factor of 2 or more. The frequency ratio fpeak (sample's peak frequency)/
(the local proton gyrofrequency) of the He‐band waves (∼0.11–0.16) under steady quiet conditions is lower than that (∼0.14–0.24) in previous studies. These results may be due to the fact that the plasmasphere expanded more frequently to the geosynchronous region under extremely quiet geomagnetic conditions in 2007–2008 than the periods selected in previous studies. The amplitude and frequency of He‐band EMIC waves for nonlinear wave growth are examined as changing cold plasma density at geosynchronous orbit. We confirm that the spectral properties of observed EMIC waves are in good agreement with the nonlinear theory.
Scaling the sandbox—Mechanical (dis) similarities of granular materials and brittle rock
Authors: Ritter Malte C. , Leever Karen , Rosenau Matthias , Oncken Onno
Published: August 2016

Analog sandbox experiments are an important tool to understand brittle tectonic deformation. To date, most experiments are interpreted kinematically only. With the advent of reliable, small‐scale force sensors, however, their dynamic evolution becomes available for analysis, offering new insights into the transient evolution of tectonic systems. Both rock and granular materials show an evolution of strain hardening and weakening during loading in the brittle‐plastic regime, but so far, this similarity has only been appreciated qualitatively. As strain weakening is a vital parameter controlling fault reactivation and lifetime, it requires proper scaling. We therefore measured and analyzed two common granular analog model materials (quartz sand and glass microbeads) using ring‐shear tests at a range of normal loads typical for analog experiments. We find two different modes of strain weakening as a function of normal load: Strain weakening at normal loads <1 kPa is due to partial loss of extrapolated cohesion, while at normal loads >1 kPa it is controlled by reduction of internal friction, which is consistent with previous measurements in this range. We show that this introduces a scale dependence into the scaling and restricts the possible use of the tested materials to crustal‐scale models with a length scaling factor of
. For these we quantitatively compare the model materials' transient strength evolution to that known from natural rock and the Earth's crust.
A hybrid method to estimate suspended particle sizes from satellite measurements over Bohai Sea and Yellow Sea
Authors: Sun Deyong , Qiu Zhongfeng , Hu Chuanmin , Wang Shengqiang , Wang Lin , Zheng Lufei , Peng Tian , He Yijun
Published: August 2016

Particle‐size distribution (PSD), a measure of particle concentrations at different sizes, is of great importance to the understanding of many biogeochemical processes in coastal marine ecosystems. Here, a hybrid method, including analytical, semianalytical, and empirical steps, is developed to estimate PSD through the median diameter of suspended particles (
). Four cruise surveys were conducted to measure optical scattering properties, particle concentrations, spectral reflectance, and particle‐size distributions (obtained with a LISST instrument covering a size range of 2.5–500 μm) in coastal waters of Bohai Sea, Yellow Sea, and Jiangsu coastal region. Based on the Mie scattering theory,
is closely related to mass‐specific backscattering coefficient of suspended particles (
), and their relationship is calibrated through a power model (R2 = 0.796, n = 67, p < 0.001) for the
range of 23.5–379.8 μm. The model is shown to perform better than the previously used inverse‐proportion model. The retrieval of
is through a bio‐optical model that links remote sensing reflectance just beneath the surface to inherent optical properties, where a close empirical relationship is established between particulate backscattering and particle concentration. The hybrid method shows high degree of fitting (R2 = 0.875, n = 46, p < 0.001) between the measured and estimated
for the size range of 17.2–325.2 μm used in the model calibration, while validation using two independent data sets shows mean absolute percentage errors of 46.0% and 64.7%, respectively. Application of the hybrid method to MODIS (Moderate Resolution Imaging Spectroradiometer) data results in spatial distributions of
that are generally consistent with those from in situ observations, suggesting potential use of the method in studying particle dynamics through time series of remote sensing observations. However, its general applicability to other regions still requires further research.
The phenology of Arctic Ocean surface warming
Authors: Steele Michael , Dickinson Suzanne
Published: August 2016

In this work, we explore the seasonal relationships (i.e., the phenology) between sea ice retreat, sea surface temperature (SST), and atmospheric heat fluxes in the Pacific Sector of the Arctic Ocean, using satellite and reanalysis data. We find that where ice retreats early in most years, maximum summertime SSTs are usually warmer, relative to areas with later retreat. For any particular year, we find that anomalously early ice retreat generally leads to anomalously warm SSTs. However, this relationship is weak in the Chukchi Sea, where ocean advection plays a large role. It is also weak where retreat in a particular year happens earlier than usual, but still relatively late in the season, primarily because atmospheric heat fluxes are weak at that time. This result helps to explain the very different ocean warming responses found in two recent years with extreme ice retreat, 2007 and 2012. We also find that the timing of ice retreat impacts the date of maximum SST, owing to a change in the ocean surface buoyancy and momentum forcing that occurs in early August that we term the Late Summer Transition (LST). After the LST, enhanced mixing of the upper ocean leads to cooling of the ocean surface even while atmospheric heat fluxes are still weakly downward. Our results indicate that in the near‐term, earlier ice retreat is likely to cause enhanced ocean surface warming in much of the Arctic Ocean, although not where ice retreat still occurs late in the season.
Seasonal evolution of the Yellow Sea Cold Water Mass and its interactions with ambient hydrodynamic system
Authors: Li Jianchao , Li Guangxue , Xu Jishang , Dong Ping , Qiao Lulu , Liu Shidong , Sun Pingkuo , Fan Zhisong
Published: August 2016

The Yellow Sea Cold Water Mass (YSCWM) is an important component of the hydrodynamic system in the South Yellow Sea (SYS). However, its intricate interactions with the ambient flows over long time scales are not fully understood. This paper presents the analysis of the data set obtained from a seabed‐mounted Acoustic Doppler Current Profiler (ADCP) deployed for nearly 1 year in the western SYS. It allowed us to study the evolution of YSCWM, including the seasonal changes of tidal currents, near‐inertial oscillations (NIOs), and the wind‐driven currents due to typhoons and winter storms. Strong NIOs were found near the bottom of mixed layer and in the pycnocline with nearly opposite current directions, with maximum velocity of nearly 20 cm·s−1 in summer. The YSCWM can also inhibit the direct downward energy transport in the water column due to typhoons. Conversely, the hydrodynamic system also feeds back to influence the change of YSCWM. A large current shear (S) of 20 cm·s−1·m−1 is generated near the top of pycnocline. Generally, the intensity and depth of the pycnocline determine S's magnitude and vertical location, respectively. Based on the monthly averaged density profile data, the Richardson number and wavelet analysis, the NIOs are considered to be capable of inducing predominant shear instability around the pycnocline. However, the NIOs are not strong enough to influence the lower YSCWM. In addition, in autumn, each fortnightly spring tide corresponds with a bottom temperature increase of nearly 2°C, indicating that tidal currents are the leading hydrodynamic driving force to decline the YSCWM.
Evaporation and surface energy budget over the largest high‐altitude saline lake on the Qinghai‐Tibet Plateau
Authors: Li Xiao‐Yan , Ma Yu‐Jun , Huang Yong‐Mei , Hu Xia , Wu Xiu‐Chen , Wang Pei , Li Guang‐Yong , Zhang Si‐Yi , Wu Hua‐Wu , Jiang Zhi‐Yun , Cui Bu‐Li , Liu Lei
Published: August 2016

Interactions between lakes and the atmosphere at high altitudes are still poorly understood due to difficulty in accessibility of direct measurements. This is particularly true for the Qinghai‐Tibet Plateau (QTP), where approximately 50% of the lakes in China are located. Continuous direct measurements of the water flux and surface energy budget were made over the largest high‐altitude saline lake in China, Qinghai Lake on the northeastern QTP, using the eddy covariance method from 11 May 2013 to 10 May 2015. Results indicated that annual evaporation of Qinghai Lake was 832.5 mm for 2013/2014 and 823.6 mm for 2014/2015, respectively. The surface energy budget and evaporation showed a strong seasonal pattern, with peaks in the latent and sensible heat flux observed in autumn and early winter. There was a 2–3 month delay between the maximum net radiation and maximum latent and sensible heat fluxes. Intraseasonal and seasonal variations in latent and sensible heat flux were strongly affected by different air masses. Westerly cold and dry air masses increased evaporation while southeast moist air mass suppressed evaporation, suggesting that the lakes might serve as an “air conditioner” to modify the temporal heat and water flux in the QTP.
Climate‐tectonic coupling: Variations in the mean, variations about the mean, and variations in mode
Authors: Lenardic A. , Jellinek A. M. , Foley B. , O'Neill C. , Moore W. B.
Published: August 2016

Interactions among tectonics, volcanism, and surface weathering are critical to the long‐term climatic state of a terrestrial planet. Volcanism cycles greenhouse gasses into the atmosphere. Tectonics creates weatherable topography, and weathering reactions draw greenhouse gasses out of the atmosphere. Weathering depends on physical processes governed partly by surface temperature, which allows for the potential that climate‐tectonic coupling can buffer the surface conditions of a planet in a manner that allows liquid water to exist over extended timescales (a condition that allows a planet to be habitable by life as we know it). We discuss modeling efforts to explore the level to which climate‐tectonic coupling can or cannot regulate the surface temperature of a planet over geologic time. Thematically, we focus on how coupled climate‐tectonic systems respond to the following: (1) changes in the mean pace of tectonics and associated variations in mantle melting and volcanism, (2) large‐amplitude fluctuations about mean properties such as mantle temperature and surface plate velocities, and (3) changes in tectonic mode. We consider models that map the conditions under which plate tectonics can or cannot provide climate buffering as well as models that explore the potential that alternate tectonic modes can provide a level of climate buffering that allows liquid water to be present at a planet's surface over geological timescales. We also discuss the possibility that changes in the long‐term climate state of a planet can feedback into the coupled system and initiate changes in tectonic mode.
A process‐oriented evaluation of dust emission parameterizations in CESM: Simulation of a typical severe dust storm in East Asia
Authors: Wu Chenglai , Lin Zhaohui , He Juanxiong , Zhang Minghua , Liu Xiaohong , Zhang Renjian , Brown Hunter
Published: August 2016

Dust emissions in climate and earth system models are associated with large uncertainties. These models often use the source erodibility (S) to constrain dust emissions and also lack explicit representations of the impact of surface roughness elements (SREs) on the threshold friction velocity (u*t). This study presents a process‐oriented evaluation of dust emission parameterizations in the Community Earth System Model (CESM) by applying the model to simulate a severe dust storm during 19–22 March 2010 in East Asia. Through numerical experiments, we assess the applicability of S and investigate the impact of SREs on dust emissions by implementing the roughness correction factor (fλ) to u*t. Simulation results are compared against the surface synoptic observations and station observations of dust concentrations. We found that the model can capture the main dust emission regions and reproduce the temporal‐spatial evolution of surface dust concentrations in Mongolia and northern China. With a geomorphic S (Sg), the model tends to produce excessive dust emissions over the low‐lying basins. Moreover, the high‐resolution Sg performs worse with “point sources” of strong dust emissions than the low‐resolution one. With the inclusion of fλ, total dust emissions are reduced by 24–34%, and the model reduces the overestimation of surface dust concentrations and improves their temporal variations over the vegetated regions. These results suggest that Sg may not be necessary when meteorology and land surface state are well simulated by the model and that fλ provides an important constraint on dust emissions through SREs.
A new method to partition climate and catchment effect on the mean annual runoff based on the Budyko complementary relationship
Authors: Zhou Sha , Yu Bofu , Zhang Lu , Huang Yuefei , Pan Ming , Wang Guangqian
Published: August 2016

Effect of climate change and catchment change on the long‐term water balance is of considerable interest at a range of spatial scales. The total differential of runoff within the Budyko framework, which has been widely used to attribute the change in runoff to the effect of climate and catchment changes, is not precise in which there is always some residual between the observed and estimated change in runoff. The objective of this study is to propose and evaluate a new partition method based on the Budyko complementary relationship for runoff. Algebraic identities have ensured that the change in runoff can be decomposed into two components precisely without any residuals using this complementary method. In addition, the complementary method allows estimation of the upper and lower bounds of the climate effect and catchment effect. The new method was compared with the total differential method and an extrapolation method for 15 catchments in Australia. Results show that the average range of the catchment effect using the complementary method was 6.7 mm for 14 of the 15 catchments, which is much smaller than that estimated with the total differential method (51.5 mm). The average of the upper and lower bounds was shown to be in good agreement with the effect of climate and catchment changes estimated using the extrapolation method (R2 = 0.98 for both). Correlation analysis indicates that the average of these bounds is the best estimate of the magnitude of the climate and catchment effect for the 15 catchments examined.
Pore‐scale modeling of vapor transport in partially saturated capillary tube with variable area using chemical potential
Authors: Addassi Mouadh , Schreyer Lynn , Johannesson Björn , Lin Hai
Published: August 2016

Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross‐sectional area using a single equation. There are no fitting parameters and the numerical solutions to the equation are compared with experimental results with excellent agreement. We demonstrate that isothermal vapor transport can be accurately modeled without modeling the details of the contact angle, microscale temperature fluctuations, or pressure fluctuations using a modification of the Fick‐Jacobs equation. We thus conclude that for a single, axisymmetric pore, the enhancement factor depends upon relative humidity boundary conditions at the liquid bridge interfaces, distance between liquid bridges, and bridge lengths.
Alpha‐synuclein RT‐QuIC in the CSF of patients with alpha‐synucleinopathies
Authors: Fairfoul Graham , McGuire Lynne I. , Pal Suvankar , Ironside James W. , Neumann Juliane , Christie Sharon , Joachim Catherine , Esiri Margaret , Evetts Samuel G. , Rolinski Michal , Baig Fahd , Ruffmann Claudio , Wade‐Martins Richard , Hu Michele T. M. , Parkkinen Laura , Green Alison J. E.
Published: August 2016

We have developed a novel real‐time quaking‐induced conversion RT‐QuIC‐based assay to detect alpha‐synuclein aggregation in brain and cerebrospinal fluid from dementia with Lewy bodies and Parkinson's disease patients. This assay can detect alpha‐synuclein aggregation in Dementia with Lewy bodies and Parkinson's disease cerebrospinal fluid with sensitivities of 92% and 95%, respectively, and with an overall specificity of 100% when compared to Alzheimer and control cerebrospinal fluid. Patients with neuropathologically confirmed tauopathies (progressive supranuclear palsy; corticobasal degeneration) gave negative results. These results suggest that RT‐QuiC analysis of cerebrospinal fluid is potentially useful for the early clinical assessment of patients with alpha‐synucleinopathies.
Tough TiB2‐Based Ceramic Composites Using Metallic Glass Powder as the Sintering Aid
Authors: Yang Chao , Yao Yuanpeng , Huan Yong , Fu Zhiqiang , Chen Fei , Lavernia Enrique J.
Published: August 2016

In this work, the authors report on the formation of toughened TiB2‐based ceramic composites using Ti60.8Al25Nb10V3Mo1B0.2 (at%) metallic glass powder as sintering aid fabricated by spark plasma sintering. The TiB2 ceramic powder blended with 5 wt% metallic glass sintering aid exhibits an interesting sigmoidal shrinkage behavior which is argued to be attributable to the viscous flow of metallic glass powder. The fabricated TiB2‐based ceramic composites have high relative density of 99.1% and high fracture toughness of 9.9 Mpa m1/2. The fracture toughness values obtained in this study are related to the mechanical response of the TiAl phase, which transformed from the metallic glass sintering aid. The results obtained herein provide a novel pathway for the fabrication of high‐performance ceramic composites.
Resilience to Impact by Extreme Energy Absorption in Lightweight Material Inclusions Constrained Near a Critical Point
Authors: Bishop Justin , Dai Quanqi , Song Yu , Harne Ryan L.
Published: August 2016

This work investigates a model design for lightweight, architected material inclusions that cultivate significant impact energy dissipation in structures. The inclusions are sustained near a critical point where damping is theoretically increased without bound. Using the principle, a material architecture and constraint mechanism are studied that exemplify the theory. Guided by a computational model and analysis, numerous specimens are fabricated and experimentation verifies that engineered material inclusions constrained nearer to critical points most effectively suppress structural dynamics following impact, minimize transmitted impulsive force, and better promote structural integrity. The concepts articulated here may find broad application for reusable, resilient protective structures.
Hydroactuated Configuration Alteration of Fibrous Dandelion Pappi: Toward Self‐Controllable Transport Behavior
Authors: Meng Qing'an , Wang Qianbin , Zhao Kaibin , Wang Pengwei , Liu Peiqing , Liu Huan , Jiang Lei
Published: August 2016

Stimuli‐responsive materials, especially those inspired by natural organism, have been extensively studied because of their versatile applications. Here, this study demonstrates that the unique hydroactuated reversible configuration alternation of the dandelion pappus, featured by the responsive spatial closing and opening the umbrella‐like pappus depending on the environmental humidity, is a determining factor that allows the pappus to regulate its transport behavior. It is proposed that the anisotropic hydroactuated swelling of tracheids, which are typically arranged with an oblique crossing orientation, helps to generate the directional stress on the pappus. By this strategy, the pappus control its transport behavior in response to the environmental moisture, which allows long‐distance and effective seeds dispersal selectively to local sites for optimal reproduction. Inspired by this, this study develops a hydroresponsive fiber array by integrating the hydrogel, whose configuration can be altered reversibly between the opening and closing state depending on the environmental humidity. This study believes the research can offer inspirations for designing and developing adaptive devices by using fibers array, as smart aerocraft.
Programing Performance of Wool Keratin and Silk Fibroin Composite Materials by Mesoscopic Molecular Network Reconstruction
Authors: Tu Huang , Yu Rui , Lin Zaifu , Zhang Lin , Lin Naibo , Yu Wei Dong , Liu Xiang Yang
Published: August 2016

To fabricate biocompatible composite films with tunable performance, both silk fibroin (SF, β‐crystallite rich) and keratin (α‐helix rich) materials are engineered at the mesoscale based on the molecular synergy. While SF materials display a hierarchical structure initiated from the β‐crystallite molecular networks, keratin materials reveal the networks crossly linked by disulfide bonding. It is surprising to see that the β‐crystallites of SF materials induce the conversion of the free unfolded molecular chains of keratin to β‐folding (β‐crystallites) in the SF/keratin composites. Furthermore, the α‐helices from the keratin components in the SF/keratin composites can transit to β‐sheets under stress, which gives rise to the strain‐hardening, and a better flexibility and elasticity. It follows that the tensile and biodegradable performance of the SF/keratin composites can be programmed by adjusting the ratio of SF versus keratin in the composites. Raising the SF ratio in the composite films increases the density of β‐crystallites in the networks, giving rise to the enhanced toughness and reduced biodegradation rate, but poor deformation recovery. On the other hand, increasing the ratio of keratin in the composite films increases the extensibility, strain‐hardening effect. These make them excel bio‐optical materials with controllable properties.
Exosomes from Cardiomyocyte Progenitor Cells and Mesenchymal Stem Cells Stimulate Angiogenesis Via EMMPRIN
Authors: Vrijsen Krijn R. , Maring Janita A. , Chamuleau Steven A. J. , Verhage Vera , Mol Emma A. , Deddens Janine C. , Metz Corina H. G. , Lodder Kirsten , van Eeuwijk Esther C. M. , van Dommelen Susan M. , Doevendans Pieter A. , Smits Anke M. , Goumans Marie‐José , Sluijter Joost P. G.
Published: August 2016

To date, cellular transplantation therapy has not yet fulfilled its high expectations for cardiac repair. A major limiting factor is lack of long‐term engraftment of the transplanted cells. Interestingly, transplanted cells can positively affect their environment via secreted paracrine factors, among which are extracellular vesicles, including exosomes: small bi‐lipid‐layered vesicles containing proteins, mRNAs, and miRNAs. An exosome‐based therapy will therefore relay a plethora of effects, without some of the limiting factors of cell therapy. Since cardiomyocyte progenitor cells (CMPC) and mesenchymal stem cells (MSC) induce vessel formation and are frequently investigated for cardiac‐related therapies, the pro‐angiogenic properties of CMPC and MSC‐derived exosome‐like vesicles are investigated. Both cell types secrete exosome‐like vesicles, which are efficiently taken up by endothelial cells. Endothelial cell migration and vessel formation are stimulated by these exosomes in in vitro models, mediated via ERK/Akt‐signaling. Additionally, these exosomes stimulated blood vessel formation into matrigel plugs. Analysis of pro‐angiogenic factors revealed high levels of extracellular matrix metalloproteinase inducer (EMMPRIN). Knockdown of EMMPRIN on CMPCs leads to a diminished pro‐angiogenic effect, both in vitro and in vivo. Therefore, CMPC and MSC exosomes have powerful pro‐angiogenic effects, and this effect is largely mediated via the presence of EMMPRIN on exosomes.
Functionalization of Tungsten Disulfide Nanotubes with a Conformal Humin‐Like Shell
Authors: Sade Hagit , Lellouche Jean‐Paul
Published: August 2016

Nanostructures of transition metal dichalcogenides (TMDs) exhibit excellent tribological and mechanical properties. These properties account for the intensive study of their use as additives to polymeric matrices. Functionalization of TMD nanostructures with organic chemical moieties has not yet been widely researched. Functionalization of this nature improves the ability to integrate TMD nanostructures in such matrices. In this paper, a new method for the functionalization of WS2 inorganic nanotubes (INTs) with a conformal humin‐like shell in different thicknesses is presented. The method is based on Lewis acid‐activated thioglycosylation chemistry between the nanotube surface and the carbohydrate unit. It is shown that shell thickness can be controlled by adjusting the sugar concentration. A reaction between the functionalized nanotubes and 3‐aminopropyl‐triethoxysilane (APTES), an amine‐terminated silicate, for the addition of different surface functionalities is proposed. This pathway should help improve and expand the range of TMD nanostructure applications.
New Paradigms on the Nature of Solid Electrolyte Interphase Formation and Capacity Fading of Hard Carbon Anodes in Na‐Ion Batteries
Authors: Bommier Clement , Leonard Daniel , Jian Zelang , Stickle William F. , Greaney P. Alex , Ji Xiulei
Published: August 2016

Capacity fading in Na/C half‐cells has long been attributed to the continuous formation of the solid electrolyte interphase (SEI). The SEI is often assumed to grow thicker on the carbon anode surface during cycling, eventually rendering it electrochemically inactive. However, the findings here shed new light on this assumption. It is shown that SEI has an inward progression into the anode material, not an outward one. Additionally, it is also reported that the Na‐metal counter electrode is hardly an inactive component in the Na/C half‐cell. Contrarily, it is a primary source of electrolyte degradation. It is then shown that the combination of SEI formation, along with electrolyte degradation leads to severe kinetic problems at the electrolyte/anode interface, resulting in poor electrochemical performances. However, it is also demonstrated that such negative effects in a Na/C half‐cell are easily reversible. By either drastically reducing the current rate, or pairing the carbon electrode with new electrolyte and new Na‐metal counter electrode a carbon material with a 70% capacity loss can recover its original performances. These conclusions bring forth valuable insight. This shows that in a Na/C half‐cell setting, long‐term fading is not due to the carbon material, but caused by electrolyte degradation stemming from interface phenomenon.
Graphene Hybrid Aerogels Made via Phase Transfer Strategy
Authors: Sun Rui , Li Guangyong , He Weina , Wang Jin , Song Qijun , Zhang Xuetong
Published: August 2016

3D aerogels hybridized with functional nanomaterials have great potential in the fields ranging from environmental remediation, energy storage to catalysis. However, co‐dispersion of these nanomaterials and their host–guest interaction enhancement are still great challenges. Herein, graphene hybrid aerogels incorporated with various nanomaterials have been synthesized via a phase transfer method by which the nanomaterials are transferred from the intermediate solution containing polyvinylpyrrolidone as a surfactant to graphene oxide aqueous suspension, followed by self‐assembly of these nanostructures into hybrid hydrogel precursors and subsequent supercritical drying of these precursors to obtain resulting aerogels. Reduced graphene oxide (rGO) aerogels hybridized with silver nanowires (Ag NWs), tungsten oxide nanowires, and polypyrrole nanoparticle are all realized via this method. The as‐prepared rGO‐Ag NWs hybrid aerogel exhibits low detect limit (10−8 mol L−1) when it is employed as surface enhanced Raman scattering substrate with Rhodamine 6G as target molecule.
pH‐Dependent Growth Laws and Viscoelastic Parameters of Poly‐l‐Lysine/Hyaluronic Acid Multilayers
Authors: Bütergerds Dörte , Cramer Cornelia , Schönhoff Monika
Published: August 2016

The layer‐by‐layer formation of polyelectrolyte multilayer films based on poly(l‐lysine) and hyaluronic acid (PLL/HA) is investigated in situ as a function of the pH value employing the quartz crystal microbalance with dissipation. By the use of the Kelvin–Voigt viscoelastic model, the film thickness, the complex viscosity, and the complex shear modulus are obtained as a function of the single layer number and pH. For all investigated pH values, PLL/HA films show an exponential growth behavior. However, in different pH regimes the exponentiality, represented by the exponential factor of the respective fit function, is more or less pronounced. Toward low or high pH values, PLL interdiffusion causing exponential growth is less relevant for the increase in mass coverage, though in the high (pH > 9) and the low (pH < 5) pH range thicker (PLL/HA)4 multilayers form. Here, the films are less viscous and less elastic compared to polyelectrolyte multilayers formed at intermediate pH (5 ≤ pH ≤ 9) conditions. Film thickness, viscosity, and elasticity do not only change with pH but also with the kind of the terminating layer. This odd–even effect is caused by the diffusion of PLL into and out of the multilayer film.
An Experimental Study on Mechanical Behavior of Nanographene/Epoxy Nanocomposites
Authors: Altan Mihrigül , Uysal Alper
Published: August 2016

Nanocomposites draw attention from many various fields and areas of usage increase with the improvement of their properties. For this purpose, nanographene particles have used to enhance the mechanical, thermal, and electrical properties. In the presented experimental study, nanocomposites were fabricated by reinforcing the epoxy matrix with nanographene particles at 0.5 and 1 wt%. The dispersion of nanofillers in epoxy matrix and the tensile properties of the nanocomposites were investigated. The tensile strength and stress at break increased with nanographene particles addition and well dispersion of nanofillers in epoxy matrix was achieved.
Immersed boundary method (IBM) based direct numerical simulation of open‐cell solid foams: Hydrodynamics
Authors: Das Saurish , Deen Niels G. , Kuipers J. A. M.
Published: August 2016

A sharp interface implicit immersed boundary method is developed and used for direct numerical simulations of the flow through open‐cell solid foams with a cellular structure. The complex solid structure of the foam is resolved on a non‐boundary fitted Cartesian computational‐grid. A single representative unit cell of the foam is considered in a periodic domain, and its geometry is approximated based on the structural packing of a tetrakaidecahedron. Simulations are performed for a wide range of porosities (0.638–0.962) and Reynolds numbers (0–500). Flow is enforced by applying a constant body force (momentum source) for three different flow directions along the {100}, {110}, and {111} lattice‐vectors. The drag force on the foam is calculated and a non‐dimensional drag/pressure drop correlation is proposed that fits the entire data set with an average deviation of 5.6%. Moreover, the accurate numerical simulations have helped to elucidate the detailed fluid‐solid interaction in complex porous media. © 2016 The Authors AIChE Journal published by Wiley Periodicals, Inc. on behalf of American Institute of Chemical Engineers AIChE J, 63: 1152–1173, 2017
Simplifying the screening of abdominal adiposity in Chinese children with waist‐to‐height ratio
Authors: Dong Bin , Wang Zhiqiang , Arnold Luke W. , Song Yi , Wang Hai‐Jun , Ma Jun
Published: August 2016

Objectives

The current age‐ and sex‐specific waist circumference (WC) reference for defining abdominal adiposity in Chinese children is quite complex. This study aimed to evaluate the optimal waist‐to‐height ratio (WHtR) thresholds based on the estimated WC references.

Methods

A cross‐sectional analysis of data from 121,025 Chinese children aged 7–18 years collected in 2010 was performed. Optimal WHtR thresholds were selected by Youden's index using receiver operating characteristic (ROC) curve analysis, with the estimated references of WC in Chinese children used as the gold standard.

Results

The optimal cut‐off values for identifying abdominally overweight and obese children were 0.44 and 0.46, respectively. Across the different sex and age groups, the proposed thresholds revealed high negative predictive values and areas under the ROC curve (≥0.857), and moderate to high sensitivity, specificity, and positive predictive values, ranging from 0.48 to 1.00.

Conclusions

The proposed WHtR thresholds reduce the number of cut‐off values from 48 to 2, and have a high discriminatory ability to identify abdominal adiposity in Chinese children. Am. J. Hum. Biol. 28:945–949, 2016. © 2016Wiley Periodicals, Inc.
Maternal hypertension and risk for hypospadias in offspring
Authors: Agopian A. J. , Hoang Thanh T. , Mitchell Laura E. , Morrison Alanna C. , Tu Duong , Nassar Natasha , Canfield Mark A.
Published: August 2016

Hypospadias is one of the most common birth defects in male infants. Maternal hypertension is a suspected risk factor; however, few previous studies have addressed the possibility of reporting bias, and several previous studies have not accounted for hypospadias severity. We analyzed data from the Texas Birth Defects Registry for 10,924 nonsyndromic cases and statewide vital records for deliveries during 1999–2009, using Poisson regression. After adjustment for potential confounders, hypospadias was associated with maternal hypertension (adjusted prevalence ratio: 1.5, 95% confidence interval: 1.4–1.7). Similar associations were observed with gestational and pregestational hypertension, including separate analyses restricted to the subset of cases with severe (second‐ or third‐degree) hypospadias. All of these associations were also similar among the subset of cases with isolated hypospadias (without additional birth defects). To evaluate the potential for bias due to potential hypertension misclassification, we repeated our analyses using logistic regression, comparing the cases to controls with other birth defects. In these analyses, the associations with gestational hypertension were similar, but adjusted associations with pregestational hypertension were no longer observed. Our findings support an association between gestational hypertension and hypospadias in offspring, but also suggest that previously observed associations with pregestational hypertension may have been inflated due to differential misclassification of hypertension (e.g., reporting bias). As gestational hypertension is recognized after hypospadias development, more research is needed to determine if this association reflects an increase in gestational hypertension risk secondary to hypospadias or if both conditions have shared risk factors (e.g., precursors of gestational hypertension). © 2016 Wiley Periodicals, Inc.
Palladium‐Catalyzed Allylic Substitution for the Synthesis of Pericosines
Authors: Chung Cheng‐Yu , Angamuthu Venkatachalam , Li Long‐Shiang , Hou Duen‐Ren
Published: August 2016

A sequence of vinylalumination of α‐substituted aldehydes, ring‐closing metathesis (RCM), and palladium‐catalyzed allylic substitution was utilized to prepare the biologically active natural products, pericosines, from d‐ribose. The anti‐adduct of vinylalumination was transformed into pericosine A after RCM, removal of the 4‐methoxybenzyl protecting group, and chlorination. The diacetate of the anti‐adduct was converted to pericosine C after the palladium‐catalyzed, SN2′‐type, allylic substitution. However, an unexpected dimeric product was generated in utilizing this approach to prepare pericosine E.
Therapy with eculizumab for patients with CD59 p.Cys89Tyr mutation
Authors: Mevorach Dror , Reiner Inna , Grau Amir , Ilan Uri , Berkun Yackov , Ta‐Shma Asaf , Elpeleg Orly , Shorer Zamir , Edvardson Simon , Tabib Adi
Published: August 2016

Objective

The objective of this work was to report on the outcome of eculizumab treatment in pediatric patients with recurrent acute predominantly motor, demyelinating neuropathy with conduction block, and chronic hemolysis attributed to p.Cys89Tyr mutation in the CD59 gene.

Methods

Four patients were recruited from our new registry of patients with homozygosity for the p.Cys89Tyr mutation on CD59. Participants received repeated intravenous eculizumab. In this 24‐month open‐label phase IIa study, we aimed to determine whether eculizumab reduces chronic hemolysis, and cumulative doses of steroids and intravenous immunoglobulin (IVIG), and ameliorates neurological deficits, compared to pretreatment status. Treatment response was evaluated every 2 to 4 weeks over 104 weeks and included examination with gross motor scoring by American Spinal Injury Association Impairment Scale and Inflammatory Neuropathy Cause and Treatment disability score, laboratory examination, well‐being [12‐item Short Form Health Survey; SF‐12]). Neurological relapses and cumulative dose of IVIGs and/or corticosteroids before and after treatment were documented. Red blood cells (RBCs) and neutrophils were stained to evaluate C5b‐9 deposition. ClinicalTrials.gov: NCT01579838.

Results

Dramatic and significant neurological amelioration in the upper limbs and trunk with more‐modest amelioration in the lower limbs was observed in all patients. Corticosteroid and IVIG treatment was completely stopped. No patient relapsed during treatment despite infections, and there were no hospital admissions. Decreased C3bi and C5b‐9 deposition on RBCs and neutrophils was documented (p < 0.0001). The SF‐12 health questionnaires indicated significant improvement (p < 0.003).

Interpretation

Eculizumab was safely administered to these patients. Marked clinical improvement suggests that eculizumab may be a life‐saving treatment for patients with acute predominantly motor, demyelinating neuropathy with conduction block, and secondary axonal damage attributed to primary p.Cys89Tyr mutation in the CD59 gene. Ann Neurol 2016;80:708–717
Can bio‐based chemicals meet demand? Global and regional case‐study around citrus waste‐derived limonene as a solvent for cleaning applications
Authors: Paggiola Giulia , Stempvoort Sytze Van , Bustamante Julen , Barbero José Manuel Vega , Hunt Andrew J. , Clark James H.
Published: August 2016

One common factor across many economies around the world is their high dependency on petroleum. The chemical sector is no exception and considering the paramount role that solvents play within this industry they make an ideal focus for investigating green transition potential. This work attempts to shed some light on the scarce literature regarding the quantitative assessment of substitution capacity in target markets, by examining a case study of toluene use as an industrial cleaning agent and its replacement by limonene, a widely established citrus‐peel‐derived alternative in a number of applications. The systematic approach presented here compares market demand against potential supply by evaluating current and projected scenarios based on citrus fruit and juice production both at global and regional level. The results clearly show that the potential for complete substitution of toluene by limonene at global level is certainly out of reach, but encouraging results were obtained in specific regional substitution case studies, considering both citrus‐producing and citrus‐importing countries. In these cases, there is a clear potential for limonene to substitute toluene as a solvent within and beyond the cleaning sector, leaving space for future work in this area to investigate the transition potential for other important bio‐based chemicals. © 2016 Society of Chemical Industry and John Wiley & Sons, Ltd
Enhancer deregulation in cancer and other diseases
Authors: Herz Hans‐Martin
Published: August 2016

Mutations in enhancer‐associated chromatin‐modifying components and genomic alterations in non‐coding regions of the genome occur frequently in cancer, and other diseases pointing to the importance of enhancer fidelity to ensure proper tissue homeostasis. In this review, I will use specific examples to discuss how mutations in chromatin‐modifying factors might affect enhancer activity of disease‐relevant genes. I will then consider direct evidence from single nucleotide polymorphisms, small insertions, or deletions but also larger genomic rearrangements such as duplications, deletions, translocations, and inversions of specific enhancers to demonstrate how they have the ability to impact enhancer activity of disease genes including oncogenes and tumor suppressor genes. Considering that the scientific community only fairly recently has begun to focus its attention on “enhancer malfunction” in disease, I propose that multiple new enhancer‐regulated and disease‐relevant processes will be uncovered in the near future that will constitute the mechanistic basis for novel therapeutic avenues.
Mixing and mass transfer in a pilot scale U‐loop bioreactor
Authors: Petersen Leander A.H. , Villadsen John , Jørgensen Sten B. , Gernaey Krist V.
Published: August 2016

A system capable of handling a large volumetric gas fraction while providing a high gas to liquid mass transfer is a necessity if the metanotrophic bacterium Methylococcus capsulatus is to be used in single cell protein (SCP) production. In this study, mixing time and mass transfer coefficients were determined in a 0.15 m3 forced flow U‐loop fermenter of a novel construction. The effect on the impeller drawn power when a gas was introduced into the system was also studied. Mixing time decreased and mass transfer increased with increasing volumetric liquid flow rate and specific power input. This happened also for a large volume fraction of the gas, which was shown to have only minor effect on the power drawn from the pump impeller. Very large mass transfer coefficients, considerably higher than those obtainable in an STR and previous tubular loop reactors, could be achieved in the U‐loop fermenter equipped with static mixers at modest volumetric liquid and gas flow rates. Biotechnol. Bioeng. 2017;114: 344–354. © 2016 Wiley Periodicals, Inc.