bluuebunny/crossref_metadata_2025 huggingface dataset:
Biological production, export efficiency, and phytoplankton communities across 8000 km of the South Atlantic
Authors: Howard E. M. , Durkin C. A. , Hennon G. M. M. , Ribalet F. , Stanley R. H. R.
Published: June 2017

In situ oxygen tracers (triple oxygen isotope and oxygen/argon ratios) were used to evaluate meridional trends in surface biological production and export efficiency across ~8000 km of the tropical and subtropical South Atlantic in March–May 2013. We used observations of picophytoplankton, nanophytoplankton, and microphytoplankton to evaluate community structure and diversity and assessed the relationships of these characteristics with production, export efficiency, and particulate organic carbon (POC) fluxes. Rates of productivity were relatively uniform along most of the transect with net community production (NCP) between 0 and 10 mmol O2 m−2 d−1, gross primary production (GPP) between 40 and 100 mmol O2 m−2 d−1, and NCP/GPP, a measure of export efficiency, ranging from 0.1 to 0.2 (0.05–0.1 in carbon units). However, notable exceptions to this basin‐scale homogeneity included two locations with highly enhanced NCP and export efficiency compared to surrounding regions. Export of POC and particulate nitrogen, derived from sediment traps, correlated with GPP across the transect, over which the surface community was dominated numerically by picophytoplankton. NCP, however, did not correlate with POC flux; the mean difference between NCP and POC flux was similar to published estimates of dissolved organic carbon export from the surface ocean. The interrelated rates of production presented in this work contribute to the understanding, building on the framework of better‐studied ocean basins, of how carbon is biologically transported between the atmosphere and the deep ocean.
Competing effects of surface albedo and orographic elevated heating on regional climate
Authors: Hu Shineng , Boos William R.
Published: June 2017

All else being equal, a given atmospheric pressure level is thought to be warmer over a plateau than over surrounding nonelevated terrain because of orographic “elevated heating.” However, elevated surfaces are also typically brighter due to reduced vegetation and increased ice cover. Here we assess the degree to which surface albedo compensates for orographic elevated heating. We confirm that land surface albedo generally increases with surface elevation in observations. Using a cloud system‐resolving model, we show that increased surface albedo strongly compensates for orographic elevated heating in radiative‐convective equilibrium. A nonelevated surface with the albedo of modern India would enter a runaway greenhouse regime without ventilation by monsoonal winds, while a surface with the albedo and elevation of Tibet would achieve a cooler radiative‐convective equilibrium. Surface albedo changes may thus be just as important as surface elevation changes for the evolution of low‐latitude regional climate throughout Earth's history.
Deformation in the lowermost mantle beneath Australia from observations and models of seismic anisotropy
Authors: Creasy Neala , Long Maureen D. , Ford Heather A.
Published: June 2017

Observations of seismic anisotropy near the core‐mantle boundary may yield constraints on patterns of lowermost mantle flow. We examine seismic anisotropy in the lowermost mantle beneath Australia, bounded by the African and Pacific Large Low Shear Velocity Provinces. We combined measurements of differential splitting of SKS‐SKKS and S‐ScS phases sampling our study region over a range of azimuths, using data from 10 long‐running seismic stations. Observations reveal complex and laterally heterogeneous anisotropy in the lowermost mantle. We identified two subregions for which we have robust measurements of D″‐associated splitting for a range of ray propagation directions and applied a forward modeling strategy to understand which anisotropic scenarios are consistent with the observations. We tested a variety of elastic tensors and orientations, including single‐crystal elasticity of lowermost mantle minerals (bridgmanite, postperovskite, and ferropericlase), tensors based on texture modeling in postperovskite aggregates, elasticity predicted from deformation experiments on polycrystalline MgO aggregates, and tensors that approximate the shape preferred orientation of partial melt. We find that postperovskite scenarios are more consistently able to reproduce the observations. Beneath New Zealand, the observations suggest a nearly horizontal [100] axis orientation with an azimuth that agrees well with the horizontal flow direction predicted by previous mantle flow models. Our modeling results further suggest that dominant slip on the (010) plane in postperovskite aggregates provides a good fit to the data but the solution is nonunique. Our results have implications for the mechanisms of deformation and anisotropy in the lowermost mantle and for the patterns of mantle flow.
Emergence and disappearance of interplate repeating earthquakes following the 2011 M9.0 Tohoku‐oki earthquake: Slip behavior transition between seismic and aseismic depending on the loading rate
Authors: Hatakeyama Norishige , Uchida Naoki , Matsuzawa Toru , Nakamura Wataru
Published: June 2017

We investigated spatiotemporal change in the interplate seismic activity following the 2011 Tohoku‐oki earthquake (M9.0) in the region where interseismic interplate coupling was relatively weak and large postseismic slip was observed. We classified earthquakes by their focal mechanisms to identify the interplate events and conducted hypocenter relocation to examine the detailed spatiotemporal distribution of interplate earthquakes in the mostly creeping area. The results show that many interplate earthquakes, including M ~ 6 events, emerged immediately after the Tohoku‐oki earthquake in areas where very few interplate earthquakes had been observed in the 88 previous years. The emergent earthquakes include repeating sequences, and the extremely long quiescence of small to moderate earthquakes before the Tohoku‐oki earthquake suggests that the source areas for the post‐M9 events slipped aseismically during the quiescence. The repeaters' magnitudes decayed over time following the Tohoku‐oki earthquake and some sequences disappeared within a year. The emergence of interplate earthquakes suggests that areas where aseismic slip had been dominant before the Tohoku‐oki earthquake started to cause seismic slip after the earthquake, probably due to the increased loading rate from the afterslip. The magnitude decrease and disappearance of repeaters can be interpreted as shrinkage in seismic areas around the repeaters' sources as the loading rate decreased due to the afterslip decay over time. These observations suggest that changes in the loading rate can cause slip behavior transition between seismic and aseismic. This indicates that such loading‐rate‐dependent slip behavior plays an important role in the spatiotemporal distribution of earthquakes in interplate seismogenic zones.
Parameterization of mixing by secondary circulation in estuaries
Authors: Basdurak N. B. , Huguenard K. D. , Valle‐Levinson A. , Li M. , Chant R. J.
Published: June 2017

Eddy viscosity parameterizations that depend on a gradient Richardson number Ri have been most pertinent to the open ocean. Parameterizations applicable to stratified coastal regions typically require implementation of a numerical model. Two novel parameterizations of the vertical eddy viscosity, based on Ri, are proposed here for coastal waters. One turbulence closure considers temporal changes in stratification and bottom stress and is coined the “regular fit.” The alternative approach, named the “lateral fit,” incorporates variability of lateral flows that are prevalent in estuaries. The two turbulence parameterization schemes are tested using data from a Self‐Contained Autonomous Microstructure Profiler (SCAMP) and an Acoustic Doppler Current Profiler (ADCP) collected in the James River Estuary. The “regular fit” compares favorably to SCAMP‐derived vertical eddy viscosity values but only at relatively small values of gradient Ri. On the other hand, the “lateral fit” succeeds at describing the lateral variability of eddy viscosity over a wide range of Ri. The modifications proposed to Ri‐dependent eddy viscosity parameterizations allow applicability to stratified coastal regions, particularly in wide estuaries, without requiring implementation of a numerical model.
Smoothing‐based compressed state Kalman filter for joint state‐parameter estimation: Applications in reservoir characterization and CO2 storage monitoring
Authors: Li Y. J. , Kokkinaki Amalia , Darve Eric F. , Kitanidis Peter K.
Published: June 2017

The operation of most engineered hydrogeological systems relies on simulating physical processes using numerical models with uncertain parameters and initial conditions. Predictions by such uncertain models can be greatly improved by Kalman‐filter techniques that sequentially assimilate monitoring data. Each assimilation constitutes a nonlinear optimization, which is solved by linearizing an objective function about the model prediction and applying a linear correction to this prediction. However, if model parameters and initial conditions are uncertain, the optimization problem becomes strongly nonlinear and a linear correction may yield unphysical results. In this paper, we investigate the utility of one‐step ahead smoothing, a variant of the traditional filtering process, to eliminate nonphysical results and reduce estimation artifacts caused by nonlinearities. We present the smoothing‐based compressed state Kalman filter (sCSKF), an algorithm that combines one step ahead smoothing, in which current observations are used to correct the state and parameters one step back in time, with a nonensemble covariance compression scheme, that reduces the computational cost by efficiently exploring the high‐dimensional state and parameter space. Numerical experiments show that when model parameters are uncertain and the states exhibit hyperbolic behavior with sharp fronts, as in CO2 storage applications, one‐step ahead smoothing reduces overshooting errors and, by design, gives physically consistent state and parameter estimates. We compared sCSKF with commonly used data assimilation methods and showed that for the same computational cost, combining one step ahead smoothing and nonensemble compression is advantageous for real‐time characterization and monitoring of large‐scale hydrogeological systems with sharp moving fronts.
Impact of spatially correlated pore‐scale heterogeneity on drying porous media
Authors: Borgman Oshri , Fantinel Paolo , Lühder Wieland , Goehring Lucas , Holtzman Ran
Published: June 2017

We study the effect of spatially‐correlated heterogeneity on isothermal drying of porous media. We combine a minimal pore‐scale model with microfluidic experiments with the same pore geometry. Our simulated drying behavior compares favorably with experiments, considering the large sensitivity of the emergent behavior to the uncertainty associated with even small manufacturing errors. We show that increasing the correlation length in particle sizes promotes preferential drying of clusters of large pores, prolonging liquid connectivity and surface wetness and thus higher drying rates for longer periods. Our findings improve our quantitative understanding of how pore‐scale heterogeneity impacts drying, which plays a role in a wide range of processes ranging from fuel cells to curing of paints and cements to global budgets of energy, water and solutes in soils.
Future sea level change from Antarctica's Lambert‐Amery glacial system
Authors: Pittard M. L. , Galton‐Fenzi B. K. , Watson C. S. , Roberts J. L.
Published: June 2017

Future global mean sea level (GMSL) change is dependent on the complex response of the Antarctic ice sheet to ongoing changes and feedbacks in the climate system. The Lambert‐Amery glacial system has been observed to be stable over the recent period yet is potentially at risk of rapid grounding line retreat and ice discharge given that a significant volume of its ice is grounded below sea level, making its future contribution to GMSL uncertain. Using a regional ice sheet model of the Lambert‐Amery system, we find that under a range of future warming and extreme scenarios, the simulated grounding line remains stable and does not trigger rapid mass loss from grounding line retreat. This allows for increased future accumulation to exceed the mass loss from ice dynamical changes. We suggest that the Lambert‐Amery glacial system will remain stable or gain ice mass and mitigate a portion of potential future sea level rise over the next 500 years, with a range of +3.6 to −117.5 mm GMSL equivalent.
Shallow marine response to global climate change during the Paleocene‐Eocene Thermal Maximum, Salisbury Embayment, USA
Authors: Self‐Trail Jean M. , Robinson Marci M. , Bralower Timothy J. , Sessa Jocelyn A. , Hajek Elizabeth A. , Kump Lee R. , Trampush Sheila M. , Willard Debra A. , Edwards Lucy E. , Powars David S. , Wandless Gregory A.
Published: June 2017

The Paleocene‐Eocene Thermal Maximum (PETM) was an interval of extreme warmth that caused disruption of marine and terrestrial ecosystems on a global scale. Here we examine the sediments, flora, and fauna from an expanded section at Mattawoman Creek‐Billingsley Road (MCBR) in Maryland and explore the impact of warming at a nearshore shallow marine (30–100 m water depth) site in the Salisbury Embayment. Observations indicate that at the onset of the PETM, the site abruptly shifted from an open marine to prodelta setting with increased terrestrial and fresh water input. Changes in microfossil biota suggest stratification of the water column and low‐oxygen bottom water conditions in the earliest Eocene. Formation of authigenic carbonate through microbial diagenesis produced an unusually large bulk carbon isotope shift, while the magnitude of the corresponding signal from benthic foraminifera is similar to that at other marine sites. This proves that the landward increase in the magnitude of the carbon isotope excursion measured in bulk sediment is not due to a near instantaneous release of 12C‐enriched CO2. We conclude that the MCBR site records nearshore marine response to global climate change that can be used as an analog for modern coastal response to global warming.
2017 American College of Rheumatology/American Association of Hip and Knee Surgeons Guideline for the Perioperative Management of Antirheumatic Medication in Patients With Rheumatic Diseases Undergoing Elective Total Hip or Total Knee Arthroplasty
Authors: Goodman Susan M. , Springer Bryan , Guyatt Gordon , Abdel Matthew P. , Dasa Vinod , George Michael , Gewurz‐Singer Ora , Giles Jon T. , Johnson Beverly , Lee Steve , Mandl Lisa A. , Mont Michael A. , Sculco Peter , Sporer Scott , Stryker Louis , Turgunbaev Marat , Brause Barry , Chen Antonia F. , Gililland Jeremy , Goodman Mark , Hurley‐Rosenblatt Arlene , Kirou Kyriakos , Losina Elena , MacKenzie Ronald , Michaud Kaleb , Mikuls Ted , Russell Linda , Sah Alexander , Miller Amy S. , Singh Jasvinder A. , Yates Adolph
Published: June 2017

Objective

This collaboration between the American College of Rheumatology and the American Association of Hip and Knee Surgeons developed an evidence‐based guideline for the perioperative management of antirheumatic drug therapy for adults with rheumatoid arthritis (RA), spondyloarthritis (SpA) including ankylosing spondylitis and psoriatic arthritis, juvenile idiopathic arthritis (JIA), or systemic lupus erythematosus (SLE) undergoing elective total hip (THA) or total knee arthroplasty (TKA).

Methods

A panel of rheumatologists, orthopedic surgeons specializing in hip and knee arthroplasty, and methodologists was convened to construct the key clinical questions to be answered in the guideline. A multi‐step systematic literature review was then conducted, from which evidence was synthesized for continuing versus withholding antirheumatic drug therapy and for optimal glucocorticoid management in the perioperative period. A Patient Panel was convened to determine patient values and preferences, and the Grading of Recommendations Assessment, Development and Evaluation methodology was used to rate the quality of evidence and the strength of recommendations, using a group consensus process through a convened Voting Panel of rheumatologists and orthopedic surgeons. The strength of the recommendation reflects the degree of certainty that benefits outweigh harms of the intervention, or vice versa, considering the quality of available evidence and the variability in patient values and preferences.

Results

The guideline addresses the perioperative use of antirheumatic drug therapy including traditional disease‐modifying antirheumatic drugs, biologic agents, tofacitinib, and glucocorticoids in adults with RA, SpA, JIA, or SLE who are undergoing elective THA or TKA. It provides recommendations regarding when to continue, when to withhold, and when to restart these medications, and the optimal perioperative dosing of glucocorticoids. The guideline includes 7 recommendations, all of which are conditional and based on low‐ or moderate‐quality evidence.

Conclusion

This guideline should help decision‐making by clinicians and patients regarding perioperative antirheumatic medication management at the time of elective THA or TKA. These conditional recommendations reflect the paucity of high‐quality direct randomized controlled trial data.
Sulfated Alginate as a Mimic of Sulfated Glycosaminoglycans: Binding of Growth Factors and Effect on Stem Cell Behavior
Authors: Mhanna Rami , Becher Jana , Schnabelrauch Matthias , Reis Rui L. , Pashkuleva Iva
Published: June 2017

Sulfated glycosaminoglycans (GAGs) are principal elements of the extracellular matrix, where they are involved in a plethora of signaling pathways mainly via interactions with diverse proteins such as growth factors and cytokines. However, the mechanisms that drive these interactions are not yet clear, mostly because of the difficulty to access large quantities of homogeneously sulfated natural GAGs. In this work, GAG mimics are synthesized from readily available alginate with different degrees of sulfation (DS, from 0.8 to 2.6) by simple process. The effect of the DS is determined on the binding of basic fibroblast growth factor (FGF‐2). The enzyme‐linked immunosorbent assay demonstrates that the binding of FGF‐2 is significantly greater for alginates with high DS as compared to unmodified and low sulfated analogs. These results are further applied to engineer FGF‐2‐loaded substrates for stem cell culturing using the layer‐by‐layer approach. All films support the attachment and growth of adipose derived stem cells (ADSCs). Noteworthy, highly sulfated alginates maintain the stemness of the ADSCs that exhibit remarkably long filopodia. These results can be exploited in the engineering of novel substrates that induce targeted cell behavior via controlled protein delivery and for tissue engineering constructs applicable in various regenerative approaches.
Nanoscale Mapping of Multiple Lectins on Cell Surfaces by Single‐Molecule Force Spectroscopy
Authors: Cuenot Stéphane , Bouvrée Audrey , Bouchara Jean‐Philippe
Published: June 2017

Molecular recognition events driven by protein–carbohydrate interactions play fundamental roles in various physiological and pathological processes in living organisms, including cohesion inside tissues, innate immune response, cancer cell metastasis, and infections. Unlike widely investigated carbohydrates, detailed knowledge of both the spatial organization of specific lectins and their identification on cell surfaces remains an essential prerequisite for the understanding of pathogen adhesion to host tissues and subsequent infection prevention. In this study, the spatially resolved localization, identification, and quantification of multiple carbohydrate‐binding sites are directly revealed on the surface of fungal pathogen Aspergillus fumigatus. Nanoscale reconstructed mapping from several recognition maps, corresponding each to a unique specific interaction probed by single‐molecule force spectroscopy, shows the distribution of carbohydrate‐binding sites on the pathogen surface. The identified binding sites are then blocked with the appropriate carbohydrate, attesting the possibility to control lectin‐mediated host–pathogen interactions. Germination markedly affects both the spatial distribution of carbohydrate‐binding sites, mostly expressed at the apex of hyphae, and the identity of the predominant ones, which depend on the location on germ tubes. These insights clearly open exciting avenues in nanomedicine to control host–pathogen interactions with the development of vaccines or inhibitory drugs that preferentially target the identified carbohydrate‐binding sites.
Densification and Crystallization in Fe–Based Bulk Amorphous Alloy Spark Plasma Sintered in the Supercooled Liquid Region
Authors: Paul Tanaji , Singh Ashish , Harimkar Sandip P.
Published: June 2017

Spark plasma sintering of Fe48Cr15Mo14Y2C15B6 bulk amorphous alloy at a range of temperatures in the supercooled liquid region (SLR) and above yielded near fully dense compacts. Upon sintering in the temperature range of 570–630 °C in SLR, large increments in density are observed due to enhanced sintering resulting from drastic reduction in the viscosity of the alloy. Above 630 °C, the absence of sufficient driving force for sintering and stiffening of the amorphous matrix from partial crystallization leads to sluggish densification. Analysis of the temperature profile in the sample and the die reveals that the temperature at the center of the sample is higher than that at the inner wall of the die as recorded by the thermocouple and the difference between the two is estimated to be between 31 and 53 °C.
In Situ Study of Deformation Twinning and Detwinning in Helium Irradiated Small‐Volume Copper
Authors: Han Wei‐Zhong , Ding Ming‐Shuai , Narayan R. Lakshmi , Shan Zhi‐Wei
Published: June 2017

The influence of nanoscale helium bubbles on the deformation twinning and detwinning behavior of submicron‐sized Cu is investigated under tension, compression, and cyclic loading. In situ nanomechanical tests performed inside a transmission electron microscope reveal that twinning and detwinning occur readily in helium irradiated copper under both tension and compression. Continuous shearing of helium bubbles by Shockley partials leads to twin formation, whereas the residual back‐stress accumulated from dislocation‐bubble interactions assist in detwinning. These interactions also elevate the critical shear stress for partial dislocation slip in helium irradiated Cu compared to that in fully dense Cu. The growth twin boundaries can significantly enhance the twinning stress in helium irradiated Cu pillar, and deformation twin‐growth twin boundary interaction promotes the formation of internal crack and thus accelerates failure. The effect of crystallographic orientation and sample size on the overall deformation characteristics of helium irradiated Cu is briefly discussed. The current studies show that deformation twinning and detwinning are also active deformation models in helium irradiated small‐volume copper.
Micrometer‐Sized RuO2 Catalysts Contributing to Formation of Amorphous Na‐Deficient Sodium Peroxide in Na–O2 Batteries
Authors: Wu Feng , Xing Yi , Lai Jingning , Zhang Xiaoxiao , Ye Yusheng , Qian Ji , Li Li , Chen Renjie
Published: June 2017

The results obtained herein demonstrate that the oxygen electrode plays a critical role in determining the morphology and chemical composition of discharge products in Na–O2 batteries. Micrometer‐sized cubic NaO2, film‐like NaO2, and nano‐sized amorphous spherical Na2‐xO2 are characterized as the main discharge products on the surface of reduced graphite oxide (rGO), boron‐doped rGO (B‐rGO), and micrometer‐sized RuO2 catalyst‐coated B‐rGO (m‐RuO2‐B‐rGO) cathodes, respectively. The Na–O2 battery with m‐RuO2‐B‐rGO as the cathode exhibits a much longer cycle life than those with the other cathodes, maintaining an unchanged capacity (0.5 mAh cm‐2) after 100 cycles at a current density of 0.05 mA cm‐2. A good rate capability and deep discharge–charge energy efficiency are also obtained. The excellent electrochemical performance of the battery is attributed to the effect of the micrometer‐sized RuO2 catalyst. Owing to the high affinity of RuO2 for oxygen, the amorphous phase Na2‐xO2 discharge product, which has good electrical contact with the RuO2 particles, can decompose completely under 3.1 V without a sudden voltage jump. Meanwhile, the micrometer‐sized RuO2 catalysts also provide enough active sites and space for the reactions, and effectively minimize the occurrence of side reactions between discharge products and carbon defects.
Activated Surface Charge‐Reversal Manganese Oxide Nanocubes with High Surface‐to‐Volume Ratio for Accurate Magnetic Resonance Tumor Imaging
Authors: Lei Ming , Fu Chen , Cheng Xiao , Fu Bin , Wu Niuniu , Zhang Qiang , Fu Ailing , Cheng Jingliang , Gao Jinhao , Zhao Zhenghuan
Published: June 2017

Investigating the surface structure, including crystal surface and surface‐coating ligands, of nanoparticulate T1 contrast agent may help to understand the T1 relaxation enhancement in vitro and in vivo. This study presents a novel strategy to develop high‐performance T1 magnetic resonance imaging (MRI) contrast agents through optimizing the nanocrystal surface and the nanobio interface. Based on the optimized crystal surface, the novel manganese oxide nanocubes (MOCs) show significantly higher surface‐to‐volume ratio and an approximately threefold higher r1 value compared to traditional manganese oxide nanospheres. Concurrently, transferring MOCs into aqueous media by dopamine derivatization can avoid the oxidation of Mn(II) ions and provide abundant magnetic core. This optimized surface endows MOCs with a high chemical exchange efficiency during T1 relaxation. Of particular significance, a rationally designed pH‐induced charge‐switchable surfaces can be negatively charged and corona‐free in blood and positively charged surface in tumor sites. This unique feature improves the circulation behavior of this intelligent T1 contrast agent in blood and increases cancer cell uptake to achieve accurate detection of solid tumor, holding great potential in aiding early and precise tumor diagnosis. This study provides a novel tool for sophisticated design of high‐performance T1 MRI contrast agents in bioimaging applications.
High‐Yield Synthesis of Multifunctional Tellurium Nanorods to Achieve Simultaneous Chemo‐Photothermal Combination Cancer Therapy
Authors: Huang Wei , Huang Yanyu , You Yuanyuan , Nie Tianqi , Chen Tianfeng
Published: June 2017

Tellurium (Te) is an important semiconductor material with low band‐gap energy, which has attracted considerable attention in recent years, due to its special chemical and physical properties and wide potential in electrochemistry, optoelectronics, and biological fields. This study demonstrates a facile and high‐yield synthesis strategy of Te nanorods (PTW‐TeNRs) decorated by polysaccharide–protein complex, which can achieve simultaneous chemo‐photothermal combination therapy against cancers. PTW‐TeNRs alone possess high stability under physiological conditions, potent anticancer activities through induction of reactive oxygen species overproduction, and high selectivity among tumor and normal cells. More importantly, they exhibit strong near‐infrared (NIR) absorbance and good photothermal conversion ability from NIR light to heat energy. Furthermore, in combination with NIR laser irradiation, PTW‐TeNRs exhibit excellent chemo‐photothermal efficiency and low toxicity as evidenced by highly efficient tumor ablation ability, but show no obvious histological damage to the major organs. Taken together, this study provides a valid tactic for facile synthesis of multifunctional tellurium nanorods for efficient and combinational cancer therapy.
3D Chiral Plasmonic Metamaterials Fabricated by Direct Laser Writing: The Twisted Omega Particle
Authors: Sakellari Ioanna , Yin Xinghui , Nesterov Maxim L. , Terzaki Konstantina , Xomalis Angelos , Farsari Maria
Published: June 2017

The plasmonic version of a 3D chiral meta‐atom which consists of a loop‐wire structure, namely the so‐called twisted omega particle, is experimentally realized. The structure is fabricated by direct laser writing and subsequent electroless silver plating, a novel technique capable of producing truly 3D photonic nanostructures. In this case, the metallic wire of finite length supports an electric dipole resonance, whereas the loop acts as a split‐ring resonator which exhibits a magnetic dipole resonance, leading to the separation of right‐handed circularly polarized light and the left‐handed one. The arising optical activity is discussed in terms of a single oscillator model system used classically to describe the generation of natural optical activity in chiral media, and it is shown that the twisted omega particle acts as its exact plasmonic analogue.
Diethyloxalate as “CO” Source for Palladium‐Catalyzed Ethoxycarbonylation of Bromo‐ and Chloroarene Derivatives
Authors: Monrose Amandine , Salembier Helori , Bousquet Till , Pellegrini Sylvain , Pélinski Lydie
Published: June 2017

Palladium(II)‐catalyzed ethoxycarbonylation of aryl bromides with diethyloxalate oxalate is described. Functionalized aromatic esters can be efficiently synthesized with only 0.65 mol % PdCl2(PPh3)2 catalyst under microwave irradiation and without additional ligand. This method illustrates an inexpensive and operationally simple method for the preparation of aromatic esters.

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Structure and catalytic consequence of Mg‐modified VOx/Al2O3catalysts for propane dehydrogenation
Authors: Wu Tengfang , Liu Gang , Zeng Liang , Sun Guodong , Chen Sai , Mu Rentao , Agbotse Gbonfoun Sika , Zhao Zhi‐Jian , Gong Jinlong
Published: June 2017

Supported VOxcatalysts are promising nonoxidative propane dehydrogenation (PDH) materials for their commercially attractive activity and propylene selectivity. However, they frequently suffer from rapid deactivation caused by coke deposition. This article describes the promoting role of magnesium on the stability of VOx/Al2O3catalysts for PDH. A series of VOx/Al2O3and Mg‐modified VOx/Al2O3catalysts were synthesized by an incipient wetness impregnation method. The catalysts were carefully characterized by Raman spectra, UV‐Vis spectra, STEM, TGA and in situ DRIFTS. We showed that the stability of a 12V/Al2O3catalyst was significantly improved on addition of small amounts of MgO. Experimental evidences indicate that V2O5nanoparticles emerge in the 12V/Al2O3samples, and appropriate Mg addition helps dispersing the V2O5nanoparticles into 2D VOxspecies thus decreasing coke formation and improving stability in nonoxidative dehydrogenation of propane. © 2017 American Institute of Chemical EngineersAIChE J, 2017
Offenzellige Schwämme mit niedrigen Dichten als Funktionsmaterialien
Authors: Jiang Shaohua , Agarwal Seema , Greiner Andreas
Published: June 2017

Makroporöse Schwämme sind eine Chance und Herausforderung für die Chemie und Materialwissenschaften. Die Herausforderung liegt in der Herstellung der Schwämme, die bestimmte Eigenschaftskombinationen aufweisen und zu neuen Anwendungen führen. Kennzeichnend für derartige Schwämme sind geringes Gewicht, Atmungsaktivität, spezielle Benetzungseigenschaften, großer Massentransfer, mechanische Stabilität und große Porenvolumina. Bottom‐up‐ und Top‐down‐Methoden zur Herstellung von Schwämmen aus Kohlenstoff und Polymeren sowie ausgewählte Eigenschaften und mögliche Anwendungen werden in diesem Aufsatz diskutiert.
Bildung von α‐Ketoradikalen aus Vinylbromiden und molekularem Sauerstoff mit sichtbarem Licht: Synthese von Indenonen und Dihydroindeno[1,2‐c]chromenen
Authors: Pagire Santosh K. , Kreitmeier Peter , Reiser Oliver
Published: June 2017

Ortho‐alkinylierte α‐Bromcinnamate können in einer Photokaskadenreaktion mit sichtbarem Licht und molekularem Sauerstoff zu Indenonen oder Dihydroindeno[1,2‐c]chromenen umgesetzt werden. Der einstufige Prozess verläuft über photochemische Schlüsselreaktionen wie die einleitende Aktivierung der Vinylbromide durch Energietransfer zu den entsprechenden α‐Ketoradikalen durch Reaktion mit molekularem Sauerstoff, gefolgt von der α‐Oxidation einer Areneinheit unter 6π‐Elektrocyclisierung. Die anschließende Hydroxylierung über eine Elektronenübertragung durch denselben Photokatalysator führt zu Dihydroinden[1,2‐c]chromenen.
Coupling of Magnetic and Elastic Domains in the Organic–Inorganic Layered Perovskite‐Like (C6H5C2H4NH3)2FeIICl4Crystal
Authors: Nakayama Yuki , Nishihara Sadafumi , Inoue Katsuya , Suzuki Takashi , Kurmoo Mohamedally
Published: June 2017

Multiferroic materials coupling ferroelasticity and ferromagnetism show strong magnetoelastic effects as magnetization is induced by mechanical stress or alternately strain induced by applying a magnetic field. These effects were reported for inorganic multiferroics such as LaCoxSr1−xO3. (C6H5C2H4NH3)2FeIICl4is the first example of an organic–inorganic perovskite to exhibit such effects below the canted antiferromagnetism atTC=98 K and ferroelasticity atTC=433 K. This is shown by switching the magnetic hysteresis on and off by uniaxial pressure through the strong coupling of the magnetic and elastic domains. The spin‐canting direction was controlled by mechanical stress in the heating and cooling cycles. This unique observation gives additional impetus in the search for coupled hysteretic effect in organic–inorganic multiferroics.
Carbon Dioxide Electroreduction into Syngas Boosted by a Partially Delocalized Charge in Molybdenum Sulfide Selenide Alloy Monolayers
Authors: Xu Jiaqi , Li Xiaodong , Liu Wei , Sun Yongfu , Ju Zhengyu , Yao Tao , Wang Chengming , Ju Huanxin , Zhu Junfa , Wei Shiqiang , Xie Yi
Published: June 2017

Structural parameters of ternary transition‐metal dichalcogenide (TMD) alloy usually obey Vegard law well, while interestingly it often exhibits boosted electrocatalytic performances relative to its two pristine binary TMDs. To unveil the underlying reasons, we propose an ideal model of ternary TMDs alloy monolayer. As a prototype, MoSeS alloy monolayers are successfully synthesized, in which X‐ray absorption fine structure spectroscopy manifests their shortened Mo−S and lengthened Mo−Se bonds, helping to tailor the d‐band electronic structure of Mo atoms. Density functional theory calculations illustrate an increased density of states near their conduction band edge, which ensures faster electron transfer confirmed by their lower work function and smaller charge‐transfer resistance. Energy calculations show the off‐center charge around Mo atoms not only benefits for stabilizing COOH* intermediate confirmed by its most negative formation energy, but also facilitates the rate‐limiting CO desorption step verified by CO temperature programmed desorption and electro‐stripping tests. As a result, MoSeS alloy monolayers attain the highest 45.2 % Faradaic efficiency for CO production, much larger than that of MoS2 monolayers (16.6 %) and MoSe2 monolayers (30.5 %) at −1.15 V vs. RHE. This work discloses how the partially delocalized charge in ternary TMDs alloys accelerates electrocatalytic performances at atomic level, opening new horizons for manipulating CO2 electroreduction properties.
Heterogeneous Sodium‐Manganese Oxide Catalyzed Aerobic Oxidative Cleavage of 1,2‐Diols
Authors: Escande Vincent , Lam Chun Ho , Coish Philip , Anastas Paul T.
Published: June 2017

The aerobic oxidative cleavage of 1,2‐diols using a heterogeneous catalyst only based on earth‐abundant metals manganese and sodium is reported for the first time. This reusable catalyst cleaves a variety of substrates into aldehydes or ketones with high selectivity. The reaction requires small catalytic loadings and is performed under mild conditions using ambient pressure O2 or air as the oxidant while producing water as the only by‐product. Mechanistic investigations reveal a monodentate, two‐electron oxidative fragmentation process involving a MnIV species. The eco‐friendly, innocuous catalyst is compatible with a wide range of functional groups and conditions, making it highly competitive with classical reagents, such as periodic acid or lead tetraacetate, as a preferred method for activated 1,2‐diols.
Low‐Density Open Cellular Sponges as Functional Materials
Authors: Jiang Shaohua , Agarwal Seema , Greiner Andreas
Published: June 2017

Low‐density macroporous sponges with densities less than 100 mg cm−3 are both a challenge and an opportunity for advanced chemistry and material science. The challenge lies in the precise preparation of the sponges with property combinations that lead to novel applications. Bottom‐up and top‐down chemical and engineering methods for the preparation of sponges are a major focus of this Review, with an emphasis on carbon and polymer materials. The light weight, sustainability, breathability, special wetting characteristics, large mass transfer, mechanical stability, and large pore volume are typical characteristics of sponges made of advanced materials and could lead to novel applications. Some selected sponge properties and potential applications are discussed.
Metal‐Free, Room‐Temperature Oxygen‐Atom Transfer in the N2O/CO Redox Couple as Catalyzed by [Si2Ox].+ (x=2–5)
Authors: Sun Xiaoyan , Zhou Shaodong , Yue Lei , Schlangen Maria , Schwarz Helmut
Published: June 2017

The thermal reduction of N2O by CO mediated by the metal‐free cluster cations [Si2Ox].+ (x=2–5) has been examined in the gas phase using Fourier transform ion cyclotron resonance (FT‐ICR) mass spectrometry in conjunction with quantum chemical calculations. Three successive oxidation/reduction steps occur starting from [Si2O2].+ and N2O to form eventually [Si2O5].+; the latter as well as the intermediate oxide cluster ions react sequentially with CO molecules to regenerate [Si2O2].+. Thus, full catalytic cycles occur at ambient conditions in the gas phase. Mechanistic aspects of these sequential redox processes have been addressed to reveal the electronic origins of these unparalleled reactions.
Practical Alkoxythiocarbonyl Auxiliaries for Iridium(I)‐Catalyzed C−H Alkylation of Azacycles
Authors: Tran Anh T. , Yu Jin‐Quan
Published: June 2017

The development of new and practical 3‐pentoxythiocarbonyl auxiliaries for IrI‐catalyzed C−H alkylation of azacycles is described. This method allows for the α‐C−H alkylation of a variety of substituted pyrrolidines, piperidines, and tetrahydroisoquinolines through alkylation with alkenes. While the practicality of these simple carbamate‐type auxiliaries is underscored by the ease of installation and removal, the method's utility is demonstrated in its ability to functionalize biologically relevant l‐proline and l‐trans‐hydroxyproline, delivering unique 2,5‐dialkylated amino acid analogues that are not accessible by other C−H functionalization methods.
Palladium‐Catalyzed Enantioselective Narasaka–Heck Reaction/Direct C−H Alkylation of Arenes: Iminoarylation of Alkenes
Authors: Bao Xu , Wang Qian , Zhu Jieping
Published: June 2017

A palladium‐catalyzed reaction of γ,δ‐unsaturated oxime esters with oxadiazoles afforded dihydropyrroles in good to excellent yields through an intramolecular iminopalladation/intermolecular direct heteroarene C−H alkylation cascade. This unprecedented iminoarylation of alkenes was subsequently realized in an enantioselective manner in the presence of a chiral bidentate phosphine ligand (Synphos).
Efficacy, Safety, Pharmacokinetics, and Pharmacodynamics of Filgotinib, a Selective JAK‐1 Inhibitor, After Short‐Term Treatment of Rheumatoid Arthritis: Results of Two Randomized Phase IIa Trials
Authors: Vanhoutte Frédéric , Mazur Minodora , Voloshyn Oleksandr , Stanislavchuk Mykola , Van der Aa Annegret , Namour Florence , Galien René , Meuleners Luc , van 't Klooster Gerben
Published: June 2017

Objective

JAK inhibitors have shown efficacy in rheumatoid arthritis (RA). We undertook this study to test our hypothesis that selective inhibition of JAK‐1 would combine good efficacy with a better safety profile compared with less selective JAK inhibitors.

Methods

In two 4‐week exploratory, double‐blind, placebo‐controlled phase IIa trials, 127 RA patients with an insufficient response to methotrexate (MTX) received filgotinib (GLPG0634, GS‐6034) oral capsules (100 mg twice daily or 30, 75, 150, 200, or 300 mg once daily) or placebo, added onto a stable regimen of MTX, to evaluate safety, efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of filgotinib. The primary efficacy end point was the number and percentage of patients in each treatment group meeting the American College of Rheumatology 20% improvement criteria (achieving an ACR20 response) at week 4.

Results

Treatment with filgotinib at 75–300 mg met the primary end point and showed early onset of efficacy. ACR20 response rates progressively increased to week 4, and the Disease Activity Score in 28 joints using the C‐reactive protein (CRP) level decreased. Marked and sustained improvements were observed in serum CRP level and other PD markers. The PK of filgotinib and its major metabolite was dose proportional over the 30–300 mg range. Early side effects seen with other less selective JAK inhibitors were not observed (e.g., there was no worsening of anemia [JAK‐2 inhibition related], no effects on liver transaminases, and no increase in low‐density lipoprotein or total cholesterol). A limited decrease in neutrophils without neutropenia was consistent with immunomodulatory effects through JAK‐1 inhibition. There were no infections. Overall, filgotinib was well tolerated. Events related to study drug were mild or moderate and transient during therapy, and the most common such event was nausea.

Conclusion

Selective inhibition of JAK‐1 with filgotinib shows initial efficacy in RA with an encouraging safety profile in these exploratory studies.
Cellular compartmentation follows rules: The Schnepf theorem, its consequences and exceptions
Authors: Moog Daniel , Maier Uwe G.
Published: June 2017

Is the spatial organization of membranes and compartments within cells subjected to any rules? Cellular compartmentation differs between prokaryotic and eukaryotic life, because it is present to a high degree only in eukaryotes. In 1964, Prof. Eberhard Schnepf formulated the compartmentation rule (Schnepf theorem), which posits that a biological membrane, the main physical structure responsible for cellular compartmentation, usually separates a plasmatic form a non‐plasmatic phase. Here we review and re‐investigate the Schnepf theorem by applying the theorem to different cellular structures, from bacterial cells to eukaryotes with their organelles and compartments. In conclusion, we can confirm the general correctness of the Schnepf theorem, noting explicit exceptions only in special cases such as endosymbiosis and parasitism.
Determination of the serine palmitoyl transferase inhibitor myriocin by electrospray and Q‐trap mass spectrometry
Authors: Campisi Giuseppe Matteo , Signorelli Paola , Rizzo Jessica , Ghilardi Claudio , Antognetti Jacopo , Caretti Anna , Lazarević Jelena S. , Strettoi Enrica , Novelli Elena , Ghidoni Riccardo , Rubino Federico Maria , Paroni Rita
Published: June 2017

Myriocin is a potent inhibitor of serine‐palmitoyl‐transferase, the first and rate‐determining enzyme in the sphingolipids biosynthetic pathway. This study developed, validated and applied a LC–MS/MS method to measure myriocin in minute specimens of animal tissue. The chemical analog 14‐OH–myriocin was used as the internal standard. The two molecules were extracted from the tissue homogenate by solid‐phase extraction, separated by gradient reversed‐phase liquid chromatography and measured by negative ion electrospray mass spectrometry in the triple quadrupole. Detection was accomplished by multiple reaction monitoring, employing the most representative transitions, 400@104 and 402@104 for myriocin and 14‐OH‐myriocin, respectively. The typical limit of detection and lower limit of quantitation of the optimized method were 0.9 pmol/mL (~0.016 pmol injected) and 2.3 pmol/mL, respectively, and the method was linear up to 250 pmol/mL range (r2 = 0.9996). The intra‐ and between‐day repeatability afforded a coefficient of variation ≤7.0%. Applications included quantification of myriocin in mouse lungs after 24 h from administration of ~4 nmol by intra‐tracheal delivery. Measured levels ranged from 4.11 (median; 2.3–7.4 IQR, n = 4) to 11.7 (median; 7.6–22.7 interquartile range (IQR), n = 6) pmol/lung depending on the different formulations used. Myriocin was also measured in retinas of mice treated by intravitreal injection and ranged from 0.045 (less than the limit of detection) to 0.35 pmol/retina.
A virtual engine laboratory for teaching powertrain engineering
Authors: Burke Richard D. , De Jonge Nicholas , Avola Calo , Forte Biagio
Published: June 2017

A virtual engine laboratory application for use in automotive engineering education is proposed to allow the practical teaching of powertrain calibration. The laboratory software is built as a flexible Matlab tool that can easily be transferred for applications in other disciplines and promotes the link between teaching and research.
pH‐Responsive Fluorescence Enhancement in Graphene Oxide–Naphthalimide Nanoconjugates: A Fluorescence Turn‐On Sensor for Acetylcholine
Authors: Mangalath Sreejith , Abraham Silja , Joseph Joshy
Published: June 2017

A pH‐sensitive, fluorescence “turn‐on” sensor based on a graphene oxide–naphthalimide (GO–NI) nanoconjugate for the detection of acetylcholine (ACh) by monitoring the enzymatic activity of acetylcholinesterase (AChE) in aqueous solution is reported. These nanoconjugates were synthesized by covalently anchoring picolyl‐substituted NI derivatives on the GO/reduced GO surface through a 1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide/N‐hydroxysuccinimide coupling strategy, and the morphological and photophysical properties were studied in detail. Synergistic effects of π–π interactions between GO and the NI chromophore, and efficient photoinduced electron‐ and energy‐transfer processes, were responsible for the strong quenching of fluorescence of these nanoconjugates, which were perturbed under acidic pH conditions, leading to significant enhancement of fluorescence emission. This nanoconjugate was successfully employed for the efficient sensing of pH changes caused by the enzymatic activity of AChE, thereby demonstrating its utility as a fluorescence turn‐on sensor for ACh in the neurophysiological range.