bluuebunny/crossref_metadata_2025_split huggingface dataset:
Detailed crustal thickness variations beneath the Illinois Basin area: Implications for crustal evolution of the midcontinent
Authors: Yang Xiaotao , Pavlis Gary L. , Hamburger Michael W. , Marshak Stephen , Gilbert Hersh , Rupp John , Larson Timothy H. , Chen Chen , Carpenter N. Seth 
Published: July 2017

AbstractWe present high‐resolution imaging results of crustal and upper mantle velocity discontinuities across the Illinois Basin area using both common conversion point stacking and plane wave migration methods applied to P wave receiver functions from the EarthScope Ozark, Illinois, Indiana, and Kentucky experiment. The images reveal unusually thick crust (up to 62 km) throughout the central and southeastern Illinois Basin area. A significant Moho gradient underlies the NW trending Ste. Genevieve Fault Zone, which delineates the boundary between the Illinois Basin and Ozark Dome. Relatively thinner crust (<45 km) underlies most of the Precambrian highlands surrounding the Illinois Basin and beneath the rift‐related structures of the Reelfoot Rift and the Rough Creek Graben. We consider four hypotheses to explain the presence of thick crust under the central and southeastern Illinois Basin. Crustal thickening may have been produced (1) prior to its accretion to North America around 1.55 Ga and is an inherited characteristic of this crustal province; (2) by underthrusting or shortening during Proterozoic convergent margin tectonics around 1.55–1.35 Ga; (3) by Late Precambrian magmatic underplating at the base of older crust, associated with the creation of the Eastern Granite‐Rhyolite Province around 1.3 Ga; and (4) through crustal “relamination” during an episode of Proterozoic flat‐slab subduction beneath the Illinois Basin, possibly associated with the Grenville Orogeny.
Centroid moment tensor catalogue using a 3‐D continental scale Earth model: Application to earthquakes in Papua New Guinea and the Solomon Islands
Authors: Hejrani Babak , Tkalčić Hrvoje , Fichtner Andreas 
Published: July 2017

AbstractAlthough both earthquake mechanism and 3‐D Earth structure contribute to the seismic wavefield, the latter is usually assumed to be layered in source studies, which may limit the quality of the source estimate. To overcome this limitation, we implement a method that takes advantage of a 3‐D heterogeneous Earth model, recently developed for the Australasian region. We calculate centroid moment tensors (CMTs) for earthquakes in Papua New Guinea (PNG) and the Solomon Islands. Our method is based on a library of Green's functions for each source‐station pair for selected Geoscience Australia and Global Seismic Network stations in the region, and distributed on a 3‐D grid covering the seismicity down to 50 km depth. For the calculation of Green's functions, we utilize a spectral‐element method for the solution of the seismic wave equation. Seismic moment tensors were calculated using least squares inversion, and the 3‐D location of the centroid is found by grid search. Through several synthetic tests, we confirm a trade‐off between the location and the correct input moment tensor components when using a 1‐D Earth model to invert synthetics produced in a 3‐D heterogeneous Earth. Our CMT catalogue for PNG in comparison to the global CMT shows a meaningful increase in the double‐couple percentage (up to 70%). Another significant difference that we observe is in the mechanism of events with depth shallower then 15 km and Mw < 6, which contributes to accurate tectonic interpretation of the region.
Coupled effects of phase transitions and rheology in 2‐D dynamical models of subduction
Authors: Arredondo Katrina M. , Billen Magali I. 
Published: July 2017

AbstractObservations of seismicity and seismic tomography provide a present‐day constraint on the geometry of slabs within the mantle. However, it is challenging to directly relate the observed shape of slabs to their time evolution. Phase transitions modify the buoyancy forces within slabs, affecting how slabs deform as they sink into the lower mantle and how forces are transmitted to the surface plates. Here we show that if the crustal shear zone is sufficiently weak (1020 Pa s), then the coupled effects of a compositionally dependent phase transition model and a stress‐dependent rheology lead to oscillatory plate speeds and trench motion in response to buckling and folding of the slab. On average, subducting plate velocity is 4 cm/yr and trench motion is ±0.7 cm/yr. However, during folding, subducting plate speed and trench motion increases by a factor of 3 and trench motion switches from advance to retreat. In models with a higher‐viscosity shear zone (1021 Pa s), average plate speed is lower (2 cm/yr) and there is only trench advance. Stress‐dependent weakening due to increasing driving stresses can also cause unexpected changes in plate velocity (i.e., decrease or no change). In addition, due to the added negative buoyancy from the phase transitions, slab breakoff occurs in models with a yield stress ≤500 MPa. Because of the oscillatory motion of the trench, long flat slabs do not form in the transition zone: this suggests that other factors, such as interaction of the slab with deep mantle flow, may be required to create long flat slabs.
Diffusive loss of argon in response to melt vein formation in polygenetic impact melt breccias
Authors: Mercer Cameron M. , Hodges Kip V. 
Published: July 2017

AbstractMany planetary surfaces in the solar system have experienced prolonged bombardment. With each impact, new rocks can be assembled that incorporate freshly generated impact melts with fragments of older rocks. Some breccias can become polygenetic, containing multiple generations of impact melt products, and can potentially provide important insights into the extensive bombardment history of a region. However, the amount of chronological information that can be extracted from such samples depends on how well the mineral isotopic systems of geochronometers can preserve the ages of individual melt generations without being disturbed by younger events. We model the thermal evolution of impact melt veins and the resulting loss of Ar from K‐bearing phases common in impact melt breccias to assess the potential for preserving the 40Ar/39Ar ages of individual melt generations. Our model results demonstrate that millimeter‐scale, clast‐free melt veins cause significant heating of adjacent host rock minerals and can cause detectable Ar loss in contact zones that are generally thinner than, and at most about the same thickness as, the vein width. The incorporation of cold clasts in melt veins reduces the magnitudes of heating and Ar loss in the host rocks, and Ar loss can be virtually undetectable for sufficiently clast‐rich veins. Quantitative evidence of the timing of impacts, as measured with the 40Ar/39Ar method, can be preserved in polygenetic impact melt breccias, particularly for those containing millimeter‐scale bodies of clast‐bearing melt products.
A reappraisal of the benefit‐risk profile of hydroxyurea in polycythemia vera: A propensity‐matched study
Authors: Barbui Tiziano , Vannucchi Alessandro Maria , Finazzi Guido , Finazzi Maria Chiara , Masciulli Arianna , Carobbio Alessandra , Ghirardi Arianna , Tognoni Gianni 
Published: July 2017

AbstractThe use of hydroxyurea (HU) as first line therapy in polycythemia vera (PV) has been criticized because no solid demonstration that this drug prevents thrombosis or prolongs survival has been so far produced. Here we present the outcomes of a large cohort of patients with PV included in the European Collaborative Low‐dose Aspirin (ECLAP) study. We selected 1,042 patients who, during the follow‐up, had received only phlebotomy (PHL) or HU to maintain the hematocrit level < 45%. To assure comparability, we conducted a propensity score matching analysis. The two groups (PHL n = 342 and HU n = 681) were well balanced for the parameters included in the propensity score (overall balance: χ2 = 2.44, P = 0.964). Over a comparable period of follow‐up (PHL = 29.9 vs. HU = 34.7 months), we documented an advantage of HU over PHL consistently significant with respect to the incidence of fatal/non‐fatal cardiovascular (CV) events (5.8 vs. 3.0 per 100 person‐years in PHL vs. HU group, P = 0.002) and myelofibrosis transformation that was only experienced by patients of PHL group. Evolution to acute leukemia was registered in three patients (two in PHL and one in HU group). The excess of mortality and total CV events in the PHL patients was restricted to the high‐risk group, and, compared with HU cases, was significant higher in the PHL patients who failed to reach the hematocrit target < 0.45% (P = 0.000). In conclusion, this analysis provides reliable and qualified estimates of the therapeutic profile of HU and PHL treatments for future experimental studies and for the management of PV in clinical practice.
A monocyte‐TNF‐endothelial activation axis in sickle transgenic mice: Therapeutic benefit from TNF blockade
Authors: Solovey Anna , Somani Arif , Belcher John D. , Milbauer Liming , Vincent Lucile , Pawlinski Rafal , Nath Karl A. , Kelm Robert J. , Mackman Nigel , O'Sullivan M. Gerard , Gupta Kalpna , Vercellotti Gregory M. , Hebbel Robert P. 
Published: July 2017

AbstractElaboration of tumor necrosis factor (TNF) is a very early event in development of ischemia/reperfusion injury pathophysiology. Therefore, TNF may be a prominent mediator of endothelial cell and vascular wall dysfunction in sickle cell anemia, a hypothesis we addressed using NY1DD, S+SAntilles, and SS‐BERK sickle transgenic mice. Transfusion experiments revealed participation of abnormally activated blood monocytes exerting an endothelial activating effect, dependent upon Egr‐1 in both vessel wall and blood cells, and upon NFκB(p50) in a blood cell only. Involvement of TNF was identified by beneficial impact from TNF blockers, etanercept and infliximab, with less benefit from an IL‐1 blocker, anakinra. In therapeutic studies, etanercept ameliorated multiple disturbances of the murine sickle condition: monocyte activation, blood biomarkers of inflammation, low platelet count and Hb, vascular stasis triggered by hypoxia/reoxygenation (but not if triggered by hemin infusion), tissue production of neuro‐inflammatory mediators, endothelial activation (monitored by tissue factor and VCAM‐1 expression), histopathologic liver injury, and three surrogate markers of pulmonary hypertension (perivascular inflammatory aggregates, arteriolar muscularization, and right ventricular mean systolic pressure). In aggregate, these studies identify a prominent—and possibly dominant—role for an abnormal monocyte‐TNF‐endothelial activation axis in the sickle context. Its presence, plus the many benefits of etanercept observed here, argue that pilot testing of TNF blockade should be considered for human sickle cell anemia, a challenging but achievable translational research goal.
Protecting Quantum State in Time‐Dependent Decoherence‐Free Subspaces Without the Rotating‐Wave Approximation
Authors: Wu Qi‐Cheng , Chen Ye‐Hong , Huang Bi‐Hua , Shi Zhi‐Cheng , Song Jie , Xia Yan 
Published: July 2017

AbstractIn this paper, we propose a scheme to protect quantum state by utilizing the time‐dependent decoherence‐free subspaces (TDFSs) theory without the rotating‐wave approximation (RWA). A coherent control is designed to drive the quantum system into the TDFSs, moreover, the singularities of the designed coherent control can be avoided by appropriately choosing the control parameters. From an experimental view point, the influences of variations of the control parameters and the imperfect initial state are discussed in detail. Numerical simulations confirm that the scheme can protect the quantum information from both the environmental decoherence and the control errors. In addition, by comparing with the scheme employing RWA, we show that the weak coherent control field is not suitable to create the TDFS, the counter‐rotating terms in the strong coherent control are helpful to protect the quantum information.
Polyurethane nanocomposites with click‐coupled nanodiamonds exhibiting enhanced mechanical and shape memory effects
Authors: Yoo Hye Jin , Lee Byung Hak , Mahapatra Sibdas Singha , Yang Cheol-Min , Cho Jae Whan 
Published: July 2017

ABSTRACTPoly(ɛ‐caprolactone)diol (PCL)–functionalized nanodiamonds (f‐NDs) were synthesized using a click chemistry reaction between the azide‐moiety PCL and alkyne‐moiety NDs and were incorporated into shape memory polyurethane (PU) at f‐ND concentrations of 0, 0.5, 1, and 2 wt % to produce high‐performance shape memory nanocomposites. The PU/f‐ND nanocomposites exhibited better shape recovery, shape recovery stress, and breaking stresses than pure PU. Shape recovery of greater than 95% was demonstrated for all the nanocomposites in the third cycle, and the shape recovery stresses increased significantly with the f‐ND content. These enhanced mechanical and shape recovery properties are ascribed to increased interactions between the f‐NDs and PU matrix due to incorporation of click‐coupled f‐NDs. The click‐coupled NDs can be used as nanofillers to enhance the mechanical and shape memory properties of polymers. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 45465.
SO2F2‐Mediated One‐Pot Synthesis of Aryl Carboxylic Acids and Esters from Phenols through a Pd‐Catalyzed Insertion of Carbon Monoxide
Authors: Fang Wan‐Yin , Leng Jing , Qin Hua‐Li 
Published: July 2017

AbstractA one‐pot Pd‐catalyzed carbonylation of phenols into their corresponding aryl carboxylic acids and esters through the insertion of carbon monoxide has been developed. This procedure offers a direct synthesis of aryl carboxylic acids and esters from inexpensive and abundant starting materials (phenols, SO2F2 and CO) under mild conditions. This method tolerates a broad range of functional groups and is also applicable for the modification of complicated natural products.
Vitamin D supplementation differentially affects seasonal multiple sclerosis disease activity
Authors: Miclea Andrei , Miclea Marius , Pistor Maximilian , Hoepner Andreas , Chan Andrew , Hoepner Robert 
Published: July 2017

AbstractObjectivesLow ultraviolet‐B (UVB) radiation causes hypovitaminosis D, which is a known risk factor for multiple sclerosis (MS) and associated with MS disease activity. Our objective is to test whether vitamin D supplementation is most effective in lowering disease activity during the period of the year with low UVB radiation and consequently low serum 25‐hydroxyvitamin D3 (25(OH)D3) concentration.MethodsRetrospective analysis of medical records from our outpatient department identified 40 MS patients with available data of at least 6 months before and during oral vitamin D supplementation. Serum 25(OH)D3 concentration was analyzed using immunoassay. UVB radiation data were provided by the local government. Annualized and quarterly relapse rates before and during vitamin D supplementation served as outcome parameters.ResultsDuring vitamin D supplementation (18,950 international units/week (mean, SD 3,397)), serum 25(OH)D3 concentration increased by 51 nmol/L and the UVB‐related seasonal variability in 25(OH)D3 levels ceased (rho = −0.13, p > .05). Furthermore, the annualized relapse rate decreased by approximately 50%. This was almost solely driven by the prominent reduction in the quarterly relapse rate in late winter/early spring, when 25(OH)D3 levels of nonsupplemented patients were the lowest.ConclusionsOur study demonstrated the modulation of seasonal MS disease activity through vitamin D supplementation. Given the prominent reduction in the quarterly relapse rate in late winter/early spring, our data indicate a beneficial effect of supplementing MS patients with vitamin D, especially during this period of the year.
Longitudinal study of neuropathy, microangiopathy, and autophagy in sural nerve: Implications for diabetic neuropathy
Authors: Mohseni Simin , Badii Medeea , Kylhammar Axel , Thomsen Niels O. B. , Eriksson Karl‐Fredrik , Malik Rayaz A. , Rosén Ingmar , Dahlin Lars B. 
Published: July 2017

AbstractObjectivesThe progression and pathophysiology of neuropathy in impaired glucose tolerance (IGT) and type 2 diabetes (T2DM) is poorly understood, especially in relation to autophagy. This study was designed to assess whether the presence of autophagy‐related structures was associated with sural nerve fiber pathology, and to investigate if endoneurial capillary pathology could predict the development of T2DM and neuropathy.Patients and MethodsSural nerve physiology and ultrastructural morphology were studied at baseline and 11 years later in subjects with normal glucose tolerance (NGT), IGT, and T2DM.ResultsSubjects with T2DM had significantly lower sural nerve amplitude compared to subjects with NGT and IGT at baseline. Myelinated and unmyelinated fiber, endoneurial capillary morphology, and the presence and distribution of autophagy structures were comparable between groups at baseline, except for a smaller myelinated axon diameter in subjects with T2DM and IGT compared to NGT. The baseline values of the subjects with NGT and IGT who converted to T2DM 11 years later demonstrated healthy smaller endoneurial capillary and higher g‐ratio versus subjects who remained NGT. At follow‐up, T2DM showed a reduction in nerve conduction, amplitude, myelinated fiber density, unmyelinated axon diameter, and autophagy structures in myelinated axons. Endothelial cell area and total diffusion barrier was increased versus baseline.ConclusionsWe conclude that small healthy endoneurial capillary may presage the development of T2DM and neuropathy. Autophagy occurs in human sural nerves and can be affected by T2DM. Further studies are warranted to understand the role of autophagy in diabetic neuropathy.
Facile Synthesis of a Novel Hierarchical ZSM‐5 Zeolite: A Stable Acid Catalyst for Dehydrating Glycerol to Acrolein
Authors: Beerthuis Rolf , Huang Liang , Shiju N. Raveendran , Rothenberg Gadi , Shen Wei , Xu Hualong 
Published: July 2017

AbstractCatalytic biomass conversion is often hindered by coking. Carbon compounds cover active surface and plug pores, causing catalyst deactivation. Material design at the nanoscale allows tailoring of the catalytic activity and stability. Here, we report a simple synthesis of nanosized ZSM‐5 materials by using a silicalite‐1 seeding suspension. ZSM‐5 crystals were grown from a deionized silica source in the presence of ammonia. By using silicalite‐1 seeds, crystalline ZSM‐5 is synthesized without any structure‐directing agent. This method allows parallel preparation of a range of ZSM‐5 samples, eliminating time‐consuming ion‐exchange steps. Mesoporosity is introduced by formation of intercrystallite voids, owing to nanocrystal agglomeration. The effects of crystal sizes and morphologies are then evaluated in the catalytic dehydration of glycerol to acrolein, with results compared against commercial ZSM‐5. The most active nanosized ZSM‐5 catalysts were five times more stable compared with commercial ZSM‐5, giving quantitative conversion and twice the acrolein yield compared with the commercial catalyst. The influence of the catalyst structure on the chemical diffusion and the resistance to coking are discussed.
Intramolecular Hydroamination by a Primary Amine of an Unactivated Alkene on Gold Nanoclusters: A DFT Study
Authors: Bobuatong Karan , Sakurai Hidehiro , Ehara Masahiro 
Published: July 2017

AbstractDensity functional theory calculations have been used to investigate the mechanism of intramolecular hydroamination of unactivated alkenes by using primary amines on gold nanoclusters (NCs) under aerobic conditions. By examining the activation modes in the cyclization process, the olefin activation mechanism was calculated to be the most energetically feasible of the three possible pathways. The amine activation pathway suffered from a high activation barrier, which means that this pathway is unlikely to take place on gold NCs. The catalytic cycle comprises five elementary steps: (1) adsorption of O2 on Au NCs results in superoxo‐like species and provides Lewis acidic sites that allow the nucleophilic substrate, 2,2‐diphenyl‐4‐penten‐1‐amine, to be adsorbed effectively; (2) intramolecular cyclization (C−N bond formation) takes place on the Au NCs through anti‐addition of the amino group; (3) hydroperoxy moiety formation by hydrogen transfer from the cyclic intermediate to superoxo‐like species; (4) the formation of hydrogen peroxide and (5) product involves hydrogen transfer from a hydrated formic acid. Natural bond orbital analysis of the transition states that arise during C−N bond formation reveals that anti‐addition of the substrate is preferred over the syn‐addition mechanism. A possible side reaction, the formation of 2‐methylene‐4,4‐diphenylpyrrolidine through β‐hydrogen elimination, is also discussed.
Amphiphilic Mesoporous Poly(Ionic Liquid) Immobilized Heteropolyanions Towards the Efficient Heterogeneous Epoxidation of Alkenes with Stoichiometric Hydrogen Peroxide
Authors: Shi Yuming , Guo Zengjing , Wang Qian , Zhang Lingyu , Li Jing , Zhou Yu , Wang Jun 
Published: July 2017

AbstractNew mesoporous poly(ionic liquid)s (MPILs) that feature a pure polycationic framework and tunable hydrophobicity were synthesized through the free‐radical polymerization of alkyl‐functionalized ionic liquids (ILs) and bisvinylimidazolium salt. Phosphotungstic (PW) anions were immobilized firmly on these MPILs with a high dispersion and density. The obtained catalyst was effective in the epoxidation of cis‐cyclooctene with stoichiometric hydrogen peroxide (H2O2) to give a high yield (>98 %) and a remarkable H2O2 efficiency (>98 %). The maximum turnover number and turnover frequency was 2375 and 685 h−1, respectively. The catalyst can be recovered easily by filtration and reused with stable activity. Other alkenes can be converted with high yields. The extraordinary performance was attributed to the pure ionic porous framework with an enhanced hydrophobicity that not only provides strong cation–anion interactions towards the stable immobilized PW anions with a high dispersion but also enables the strong affinity of the catalyst with both the substrate and oxidant.
Copper‐Assisted Amination of Boronic Acids for Synthesis of Bulky Diarylamines: Experimental and DFT Study
Authors: Levitskiy Oleg A. , Grishin Yuri K. , Sentyurin Vyacheslav V. , Magdesieva Tatiana V. 
Published: July 2017

AbstractComparative investigation of copper‐assisted oxidative and reductive amination showed that the latter was preferable for the synthesis of bulky diarylamines. DFT estimation of the mechanism of copper(I)‐assisted reductive amination of boronic acids with aryl nitroso compounds was performed and possible active species were identified. DFT estimation of the steric penalty revealed that the barrier for the transmetalation step for the hindered nitroso compound was almost the same as that for the unsubstituted one, whereas a bulky group in the boronic acid increased the activation energy. A DFT study of the influence of the electronic properties of the substituents in both reactants on the activation energy revealed that the optimal combination for the synthesis of unsymmetrical diarylamines to provide better yields was an electron‐rich aryl boronic acid and an electron‐deficient nitroso compound. By using these helpful guidelines, a series of new bulky diarylamines were obtained and fully characterized.