bluuebunny/crossref_metadata_2025 huggingface dataset:
The Role of Pore Fluid Pressure on the Failure of Magma Reservoirs: Insights From Indonesian and Aleutian Arc Volcanoes
Authors: Albino F. , Amelung F. , Gregg P.
Published: February 2018

We use numerical models to study the mechanical stability of magma reservoirs embedded in elastic host rock. We quantify the overpressure required to open tensile fractures (the failure overpressure), as a function of the depth and the size of the reservoir, the loading by the volcanic edifice, and the pore fluid pressure in the crust. We show that the pore fluid pressure is the most important parameter controlling the magnitude of the failure overpressure rather than the reservoir depth and the edifice load. Under lithostatic pore fluid pressure conditions, the failure overpressure is on the order of the rock tensile strength (a few tens of megapascals). Under zero pore fluid pressure conditions, the failure overpressure increases linearly with depth (a few hundreds of megapascals at 5 km depth). We use our models to forecast the failure displacement (the cumulative surface displacement just before an eruption) on volcanoes showing unrest: Sinabung and Agung (Indonesia) and Okmok and Westdahl (Aleutian). By comparison between our forecast and the observation, we provide valuable constraint on the pore fluid pressure conditions on the volcanic system. At Okmok, the occurrence of the 2008 eruption can be explained with a 1,000 m reservoir embedded in high pore fluid pressure, whereas the absence of eruption at Westdahl better suggests that the pore fluid pressure is much lower than lithostatic. Our finding suggests that the pore fluid pressure conditions around the reservoir may play an important role in the triggering of an eruption by encouraging or discouraging the failure of the reservoir.
Microseismicity of an Unstable Rock Mass: From Field Monitoring to Laboratory Testing
Authors: Colombero C. , Comina C. , Vinciguerra S. , Benson P. M.
Published: February 2018

The field‐scale microseismic (MS) activity of an unstable rock mass is known to be an important tool to assess damage and cracking processes eventually leading to macroscopic failures. However, MS‐event rates alone may not be enough for a complete understanding of the trigger mechanisms of mechanical instabilities. Acoustic Emission (AE) techniques at the laboratory scale can be used to provide complementary information. In this study, we report a MS/AE comparison to assess the stability of a granitic rock mass in the northwestern Italian Alps (Madonna del Sasso). An attempt to bridge the gap between the two different scales of observation, and the different site and laboratory conditions, is undertaken to gain insights on the rock mass behavior as a function of external governing factors. Time‐ and frequency‐domain parameters of the MS/AE waveforms are compared and discussed with this aim. At the field scale, special attention is devoted to the correlation of the MS‐event rate with meteorological parameters (air temperature and rainfalls). At the laboratory scale, AE rates, waveforms, and spectral content, recorded under controlled temperature and fluid conditions, are analyzed in order to better constrain the physical mechanisms responsible for the observed field patterns. The factors potentially governing the mechanical instability at the site were retrieved from the integration of the results. Abrupt thermal variations were identified as the main cause of the site microsesimicity, without highlighting irreversible acceleration in the MS‐event rate potentially anticipating the rock mass collapse.
Vertical Variation of the Effects of Atmospheric Stability on Turbulence Statistics Within the Roughness Sublayer Over Real Urban Canopy
Authors: Zou Jun , Sun Jianning , Liu Gang , Yuan Renmin , Zhang Hongsheng
Published: February 2018

Eddy correlation measurements have been carried out at six different heights above the urban canopy in three cities of China, that is, Nanjing, Changzhou, and Suzhou. Observations at these heights are used to evaluate the dependence of normalized standard deviations of velocity components σi/u*l (i = u, v, w) and temperature
on local atmospheric stability ζ (=(z − zd)/Λ), where u*l is the local friction velocity, Tv*l is the local temperature scale, zd is the displacement height, and Λ is the local Obukhov length. It is found that the universal functions ai(1 + bi| ζ| )1/3 and
, in which ai, bi, and
are empirical coefficients, are suitable for describing the behaviors of σi/u*l and
, respectively. Under neutral conditions (|ζ| < 0.05), the value of σi/u*l (approximately equal to ai) decreases with height. On the other hand, bi increases with height under both unstable (ζ <  − 0.05) and stable (ζ > 0.05) conditions, suggesting that the thermal effect of stratification on the standard deviations of velocity components increases with height in the urban roughness sublayer. However, the behavior of
is different from that of σi/u*l.
remains constant with height under unstable conditions but increases with height under stable conditions. Vertical variations of these coefficients in the universal functions are consistent with the concept of local similarity, suggesting that the turbulence behavior in the urban roughness sublayer is different from that over the flat terrain.
A Multiplicative Cascade Model for High‐Resolution Space‐Time Downscaling of Rainfall
Authors: Raut Bhupendra A. , Seed Alan W. , Reeder Michael J. , Jakob Christian
Published: February 2018

Distributions of rainfall with the time and space resolutions of minutes and kilometers, respectively, are often needed to drive the hydrological models used in a range of engineering, environmental, and urban design applications. The work described here is the first step in constructing a model capable of downscaling rainfall to scales of minutes and kilometers from time and space resolutions of several hours and a hundred kilometers. A multiplicative random cascade model known as the Short‐Term Ensemble Prediction System is run with parameters from the radar observations at Melbourne (Australia). The orographic effects are added through multiplicative correction factor after the model is run. In the first set of model calculations, 112 significant rain events over Melbourne are simulated 100 times. Because of the stochastic nature of the cascade model, the simulations represent 100 possible realizations of the same rain event. The cascade model produces realistic spatial and temporal patterns of rainfall at 6 min and 1 km resolution (the resolution of the radar data), the statistical properties of which are in close agreement with observation. In the second set of calculations, the cascade model is run continuously for all days from January 2008 to August 2015 and the rainfall accumulations are compared at 12 locations in the greater Melbourne area. The statistical properties of the observations lie with envelope of the 100 ensemble members. The model successfully reproduces the frequency distribution of the 6 min rainfall intensities, storm durations, interarrival times, and autocorrelation function.
Investigation of Turbulent Entrainment‐Mixing Processes With a New Particle‐Resolved Direct Numerical Simulation Model
Authors: Gao Zheng , Liu Yangang , Li Xiaolin , Lu Chunsong
Published: February 2018

A new particle‐resolved three‐dimensional direct numerical simulation model is developed that combines Lagrangian droplet tracking with the Eulerian field representation of turbulence near the Kolmogorov microscale. Six numerical experiments are performed to investigate the processes of entrainment of clear air and subsequent mixing with cloudy air and their interactions with cloud microphysics. The experiments are designed to represent different combinations of three configurations of initial cloudy area and two turbulence modes (decaying and forced turbulence). Five existing measures of microphysical homogeneous mixing degree are examined, modified, and compared in terms of their ability as a unifying measure to represent the effect of various entrainment‐mixing mechanisms on cloud microphysics. Also examined and compared are the conventional Damköhler number and transition scale number as a dynamical measure of different mixing mechanisms. Relationships between the various microphysical measures and dynamical measures are investigated to search for a unified parameterization of entrainment‐mixing processes. The results show that even with the same cloud water fraction, the thermodynamic and microphysical properties are different, especially for the decaying cases. Further analysis confirms that despite the detailed differences in cloud properties among the six simulation scenarios, the variety of turbulent entrainment‐mixing mechanisms can be reasonably represented with power law relationships between the microphysical homogeneous mixing degrees and the dynamical measures.
Toward Exploring the Synergy Between Cloud Radar Polarimetry and Doppler Spectral Analysis in Deep Cold Precipitating Systems in the Arctic
Authors: Oue Mariko , Kollias Pavlos , Ryzhkov Alexander , Luke Edward P.
Published: February 2018

The study of Arctic ice and mixed‐phase clouds, which are characterized by a variety of ice particle types in the same cloudy volume, is challenging research. This study illustrates a new approach to qualitative and quantitative analysis of the complexity of ice and mixed‐phase microphysical processes in Arctic deep precipitating systems using the combination of Ka‐band zenith‐pointing radar Doppler spectra and quasi‐vertical profiles of polarimetric radar variables measured by a Ka/W‐band scanning radar. The results illustrate the frequent occurrence of multimodal Doppler spectra in the dendritic/planar growth layer, where locally generated, slower‐falling particle populations are well separated from faster‐falling populations in terms of Doppler velocity. The slower‐falling particle populations contribute to an increase of differential reflectivity (ZDR), while an enhanced specific differential phase (KDP) in this dendritic growth temperature range is caused by both the slower and faster‐falling particle populations. Another area with frequent occurrence of multimodal Doppler spectra is in mixed‐phase layers, where both populations produce ZDR and KDP values close to 0, suggesting the occurrence of a riming process. Joint analysis of the Doppler spectra and the polarimetric radar variables provides important insight into the microphysics of snow formation and allows the separation of the contributions of ice of different habits to the values of reflectivity and ZDR.
Sensitivity of Extreme Rainfall to Atmospheric Moisture Content in the Arid/Semiarid Southwestern United States: Implications for Probable Maximum Precipitation Estimates
Authors: Yang Long , Smith James
Published: February 2018

Sensitivity of extreme rainfall to atmospheric moisture content for the 19 August 2014 storm in Arizona is investigated based on numerical experiments using the Weather Research and Forecasting model. Analyses are designed to develop an improved understanding of the roles of atmospheric moisture content and complex terrain in controlling spatial and temporal variability of extreme rainfall in the arid/semiarid southwestern United States. The control simulation identifies complex interactions of low‐level moisture transport and orographic lift as key elements in producing extreme rainfall for the first storm episode. Two sensitivity experiments are performed by increasing the relative humidity by 10% and 20% in both initial and boundary conditions used for the control simulation. Changes in atmospheric moisture content modify the storm structure and evolution, instability of the storm environment, and interactions of synoptic flow with complex terrain. The two storm episodes within this event exhibit contrasting responses to the increase of moisture content, with rainfall accumulation and maximum convective available potential energy increased for the second storm episode as opposed to a more complex relationship for the first storm episode. A moisture maximization simulation was also designed to mimic the framework of moisture maximization in probable maximum precipitation estimates. Our results highlight the nonlinear relationship between extreme rainfall and atmospheric moisture content in complex environments where small‐scale convection plays a dominant role. Limitations of probable maximum precipitation estimates based physical models are also discussed.
Experimental Constraints on the Fatigue of Icy Satellite Lithospheres by Tidal Forces
Authors: Hammond Noah P. , Barr Amy C. , Cooper Reid F. , Caswell Tess E. , Hirth Greg
Published: February 2018

Fatigue can cause materials that undergo cyclic loading to experience brittle failure at much lower stresses than under monotonic loading. We propose that the lithospheres of icy satellites could become fatigued and thus weakened by cyclical tidal stresses. To test this hypothesis, we performed a series of laboratory experiments to measure the fatigue of water ice at temperatures of 198 K and 233 K and at a loading frequency of 1 Hz. We find that ice isnotsusceptible to fatigue at our experimental conditions and that the brittle failure stress does not decrease with increasing number of loading cycles. Even though fatigue was not observed at our experimental conditions, colder temperatures, lower loading frequencies, and impurities in the ice shells of icy satellites may increase the likelihood of fatigue crack growth. We also explore other mechanisms that may explain the weak behavior of the lithospheres of some icy satellites.
Uncertainty Quantification in Discrete Fracture Network Models: Stochastic Geometry
Authors: Berrone Stefano , Canuto Claudio , Pieraccini Sandra , Scialò Stefano
Published: February 2018

We consider the problem of uncertainty quantification analysis of the output of underground flow simulations. We consider in particular fractured media described via the discrete fracture network model; within this framework, we address the relevant case of networks in which the geometry of the fractures is described by stochastic parameters. In this context, due to a possible lack of smoothness in the quantity of interest with respect to the stochastic parameters, well assessed techniques such as stochastic collocation may fail in providing reliable estimates of first‐order moments of the quantity of interest. In this paper, we overcome this issue by applying the Multilevel Monte Carlo method, using as underlying solver an extremely robust method.
Baseline Retinal Examinations in Patients With Systemic Lupus Erythematosus Newly Initiating Hydroxychloroquine Treatment in a US Medicaid Systemic Lupus Erythematosus Population, 2000–2010
Authors: Lin Tzu‐Chieh , Marmor Michael F. , Barbhaiya Medha , Guan Hongshu , Chen Sarah K. , Feldman Candace H. , Costenbader Karen H.
Published: February 2018

Objective

Baseline retinal examinations have long been recommended for patients beginning treatment with hydroxychloroquine (HCQ), but it is unknown how well this guideline is followed. We investigated baseline eye examinations among US SLE patients enrolled in Medicaid in whom HCQ treatment was newly initiated.

Methods

Using billing codes, we identified SLE patients ages 18–65 years who were enrolled in Medicaid and residing in the 29 most populated US states, from 2000 to 2010. New users of HCQ were identified by filled prescriptions, with none filled in the preceding 12 months. Retinal examinations that were performed within 30 days before to 1 year after the index prescription were identified. We examined the proportions of patients receiving retinal examinations over the study years and compared the characteristics of those who did and those who did not receive examinations, using bivariable and multivariable logistic regression models.

Results

Among 12,755 SLE patients newly starting HCQ treatment, 32.5% received baseline dilated eye examinations. The proportions of patients receiving baseline eye examinations did not significantly change from 2000 to 2010 (31.0–34.4%; P for linear trend = 0.12). Factors associated with an increased likelihood of having an examination included female sex, Asian versus white race, and a higher number of laboratory tests performed during the preceding year. Compared with white patients, lower proportions of black and Native American patients with SLE had baseline retinal examinations.

Conclusion

Only one‐third of patients with SLE enrolled in Medicaid and in whom HCQ was newly initiated received the recommended baseline retinal examinations, and this proportion did not significantly increase from 2000 to 2010. The sociodemographic variation in this recommended care has been observed for other recommended medical care in SLE and requires both further investigation and interventions to address it.
Mixed‐Methods Study Identifying Key Intervention Targets to Improve Participation in Daily Living Activities in Primary Sjögren's Syndrome Patients
Authors: Hackett Katie L. , Deane Katherine H. O. , Newton Julia L. , Deary Vincent , Bowman Simon J. , Rapley Tim , Ng Wan‐Fai ,   United Kingdom Primary Sjögren's Syndrome Registry
Published: February 2018

Objective

Functional ability and participation in life situations are compromised in many primary Sjögren's syndrome (SS) patients. This study aimed to identify the key barriers and priorities to participation in daily living activities, in order to develop potential future interventions.

Methods

Group concept mapping, a semiquantitative, mixed‐methods approach was used to identify and structure ideas from UK primary SS patients, adult household members living with a primary SS patient, and health care professionals. Brainstorming generated ideas, which were summarized into a final set of statements. Participants individually arranged these statements into themes and rated each statement for importance. Multidimensional scaling and hierarchical cluster analysis were applied to sorted and rated data to produce visual representations of the ideas (concept maps), enabling identification of agreed priority areas for interventions.

Results

A total of 121 patients, 43 adult household members, and 67 health care professionals took part. In sum, 463 ideas were distilled down to 94 statements. These statements were grouped into 7 clusters: Patient Empowerment, Symptoms, Wellbeing, Access and Coordination of Health Care, Knowledge and Support, Public Awareness and Support, and Friends and Family. Patient Empowerment and Symptoms were rated as priority conceptual themes. Important statements within priority clusters indicate patients should be taken seriously and supported to self‐manage symptoms of oral and ocular dryness, fatigue, pain, and poor sleep.

Conclusion

Our data highlighted the fact that in addition to managing primary SS symptoms, interventions aiming to improve patient empowerment, general wellbeing, access to health care, patient education, and social support are important to facilitate improved participation in daily living activities.
Regulation of Breathing CuO Nanoarray Electrodes for Enhanced Electrochemical Sodium Storage
Authors: Ni Jiangfeng , Jiang Yu , Wu Feixiang , Maier Joachim , Yu Yan , Li Liang
Published: February 2018

Cupric oxide (CuO) represents an attractive anode material for sodium‐ion batteries owing to its large capacity (674 mAh g−1) associated with multiple electron transfer. However, the substantial volume swelling and shrinking (≈170%) upon Na uptake and release, which mimics an electrode breathing process, disturbs the structural integrity, leading to poor electrochemical durability and low Coulombic efficiency. Here, a structural strategy to regulate the breathing of CuO nanoarray electrodes during Na cycling using an atomic layer deposition of cohesive TiO2 thin films is presented. CuO nanoarrays are electrochemically grown on 3D Cu foam and directly used as anodes for sodium storage. The regulated CuO electrode arrays enable a large reversible capacity (592 mAh g−1), a high cycle efficiency (≈100%), and an excellent cycling stability (82% over 1000 cycles), which are some of the best sodium storage performance values reported for CuO systems. Electrochemical impedance and microscopic examination reveal that the enhanced performance is a direct outcome of the efficient regulation of the breathing of CuO nanowires by TiO2 layer.
Low‐Dimensional Plasmonic Photodetectors: Recent Progress and Future Opportunities
Authors: Huang Jian‐An , Luo Lin‐Bao
Published: February 2018

Plasmonic nanostructures can achieve subdiffraction‐limit light confinement with enhanced electric fields. By taking advantage of the light‐confinement effect, various plasmonic photodetectors that combine low‐dimensional (LD) semiconductor structures and plasmonic materials have recently demonstrated excellent plasmon‐enhanced device performance and attracted significant research interest. In this review, the state‐of‐the‐art progress in the development of various LD photodetectors with different plasmonic structures is briefly surveyed, in order to provide a clear picture of related fabrication methods, leading to maximized plasmonic enhancement. The fundamentals of localized surface‐plasmon resonance and plasmonic hot electrons are first introduced, followed by a summary of several prototypical LD photodetectors enhanced by metal nanoparticles (NPs), including noble‐metal NPs, poor‐metal NPs, and some plasmonic doped‐semiconductor NPs. The recent achievement of the newly developed LD photodetectors propelled by plasmonic hot carriers is also highlighted. Finally, some challenges and issues that need to be resolved in this field are proposed.
Universality of the Sodium Ion Binding Mechanism in Class A G‐Protein‐Coupled Receptors
Authors: Selvam Balaji , Shamsi Zahra , Shukla Diwakar
Published: February 2018

The allosteric modulation of G‐protein‐coupled receptors (GPCRs) by sodium ions has received significant attention as crystal structures of several receptors show Na+ ions bound to the inactive conformations at the conserved Asp2.50. To date, structures from 24 families of GPCRs have been determined, though mechanistic insights into Na+ binding to the allosteric site are limited. We performed hundreds‐of‐microsecond long simulations of 18 GPCRs and elucidated their Na+ binding mechanism. In class A GPCRs, the Na+ ion binds to the conserved residue 2.50 whereas in class B receptors, it binds at 3.43b, 6.53b, and 7.49b. Using Markov state models, we obtained the free energy profiles and kinetics of Na+ binding to the allosteric site, which reveal a conserved mechanism of Na+ binding for GPCRs and show the residues that act as major barriers for ion diffusion. Furthermore, we also show that the Na+ ion can bind to GPCRs from the intracellular side when the allosteric site is inaccessible from the extracellular side.
Absolute Configuration of Pharmaceutical Research Compounds Determined by X‐ray Powder Diffraction
Authors: Schlesinger Carina , Tapmeyer Lukas , Gumbert Silke D. , Prill Dragica , Bolte Michael , Schmidt Martin U. , Saal Christoph
Published: February 2018

The absolute configuration of active pharmaceutical ingredients (APIs) was determined by generating salts of the active pharmaceutical ingredient (API) with counterions of known chirality, and determining the crystal structures by X‐ray powder diffraction. This approach avoids the (often tedious) growth of single crystals, and is successful with very limited quantities of material (less than 1 mg). The feasibility of the method is demonstrated on five examples, and its limitations are discussed as well.
Cauchy stresses and vibration frequencies for the instability parameters of dielectric elastomer actuators
Authors: Kim Tae‐Jong , Liu Yanju , Leng Jinsong
Published: February 2018

An analysis of the effect of Cauchy stresses, vibration frequency response, and instability on the transient dynamic response of step‐voltage‐driven dielectric elastomer actuators (DEAs) is presented in this paper. Material nonlinearities associated with the hyperelastic constitutive law are taken into account, and the membrane is assumed to be made of an isotropic, homogeneous, and incompressible material. The results for the neo‐Hookean material model are further extended to analyze relatively complex multiparameter hyperelastic models (Mooney–Rivlin and Ogden) that are often employed for investigating the behavior of DEAs. The dynamic instability parameters are predicted using energy‐based extraction of static instability and validated by the response of the material in the vicinity of the dynamic instability. The natural modes of the membrane are used to approximate the nonlinear deformation field using the Galerkin method. A detailed parametric analysis of the equations of motion for the prestretched membrane shows the natural frequencies and mode shapes of the membrane and the strong influence of the stretching ratios and material parameters on the linear and nonlinear oscillations of the membrane. The results of the present investigation show the electric field–frequency relations, resonance curves, and bifurcation diagrams using the nonlinear dynamics of DEAs subjected to electrical loads. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46215.
Transforming Growth Factor β Activation Primes Canonical Wnt Signaling Through Down‐Regulation of Axin‐2
Authors: Gillespie Justin , Ross Rebecca L. , Corinaldesi Clarissa , Esteves Filomena , Derrett‐Smith Emma , McDermott Michael F. , Doody Gina M. , Denton Christopher P. , Emery Paul , Del Galdo Francesco
Published: February 2018

Objective

Aberrant activation of Wnt signaling has been observed in tissues from patients with systemic sclerosis (SSc). This study aimed to determine the role of transforming growth factor β (TGFβ) in driving the increased Wnt signaling, through modulation of axis inhibition protein 2 (Axin‐2), a critical regulator of the Wnt canonical pathway.

Methods

Canonical Wnt signaling activation was analyzed by TOPflash T cell factor/lymphoid enhancer factor promoter assays. Axin‐2 was evaluated in vitro by analysis of Axin‐2 primary/mature transcript expression and decay, TGFβ receptor type I (TGFβRI) blockade, small interfering RNA–mediated depletion of tristetraprolin 1, and XAV‐939–mediated Axin‐2 stabilization. In vivo, Axin‐2 messenger RNA (mRNA) and protein expression was determined in skin and lung biopsy samples from mice that express a kinase‐deficient TGFβRII specifically on fibroblasts (TβRIIΔk‐fib–transgenic mice) and from littermate controls.

Results

SSc fibroblasts displayed an increased response to canonical Wnt ligands despite basal levels of Wnt signaling that were comparable to those in healthy control fibroblasts in vitro. Notably, we showed that SSc fibroblasts had reduced basal expression of Axin‐2, which was caused by an endogenous TGFβ–dependent increase in Axin‐2 mRNA decay. Accordingly, we observed that TGFβ decreased Axin‐2 expression both in vitro in healthy control fibroblasts and in vivo in TβRIIΔk‐fib–transgenic mice. Additionally, using Axin‐2 gain‐ and loss‐of‐function experiments, we demonstrated that the TGFβ‐induced increased response to Wnt activation characteristic of SSc fibroblasts depended on reduced bioavailability of Axin‐2.

Conclusion

This study highlights the importance of reduced bioavailability of Axin‐2 in mediating the increased canonical Wnt response observed in SSc fibroblasts. This novel mechanism extends our understanding of the processes involved in Wnt/β‐catenin–driven pathology and supports the rationale for targeting the TGFβ pathway to regulate the aberrant Wnt signaling observed during fibrosis.
Bright Photoluminescence of [{(Cp)2Ce(μ‐Cl)}2]: A Valuable Technique for the Determination of the Oxidation State of Cerium
Authors: Suta Markus , Harmgarth Nicole , Kühling Marcel , Liebing Phil , Edelmann Frank T. , Wickleder Claudia
Published: February 2018

The synthesis and photoluminescence properties of the bright‐yellow organocerium complex [{(Cp
)2Ce(μ‐Cl)}2] (Cp
=1,3‐di(tert‐butyl)cyclopentadienyl) are presented. This coordination compound exhibits highly efficient photoluminescence within the yellow‐light wavelength range, with a high internal quantum yield of 61(±2) % at room temperature. The large red shift is attributed to the delocalizing ability of the aromatic ligands, whilst its quantum yield even makes this compound competitive with Ce3+‐activated LED phosphors in terms of its photoluminescence efficiency (disregarding its thermal stability). A bridging connection between two crystallographically independent Ce3+ ions is anticipated to be the reason for the highly efficient photoluminescence, even up to room temperature. The emission spectrum is characterized by two bands in the orange‐light range at both 10 K and room temperature, which are attributed to the parity‐allowed transitions 5d1(2D3/2)→4f1(2F7/2) and 5d1(2D3/2)→4f1(2F5/2) of Ce3+, respectively. The photoluminescence spectra were interpreted in relation to the structure and vibrational modes of the coordination compound. The spectra and optical properties indicate that trivalent cerium ions are the dominant species in the ground state, which also resolves an often‐encountered ambiguity in organocerium compounds. This result shows that photoluminescence spectroscopy is a versatile tool that can help elucidate the oxidation state of Ce in such compounds.
Bauen mit Elementwänden bei drückendem Wasser
Authors: Hohmann Rainer
Published: February 2018

Elementwände im drückenden Grundwasser erfordern eine besondere Sorgfalt bei der Planung, Ausführung und Überwachung. In dem Beitrag werden grundlegende Zusammenhänge aufgezeigt, typische Fehler erläutert und Hinweise zur Fehlervermeidung gegeben.
Wasserundurchlässige Bauwerke aus Beton
Authors: Rohr‐Suchalla Katrin , Wolfgramm Boris
Published: February 2018

Die mangelfreie Abdichtung eines Bauwerks ist für dessen Verwendungseignung von entscheidender Bedeutung, sodass die Anforderungen an die Planung und Ausführung von wasserundurchlässigen Bauwerken nach der Rechtsprechung sehr hoch sind. Um Schäden und eine Haftung zu vermeiden, müssen die am Bau Beteiligten die an sie gestellten Anforderungen berücksichtigen.

Der Auftraggeber hat die Möglichkeit, dem ausführenden Unternehmen eine konkrete Beschaffenheit des Werkes vorzugeben, die auch über den anerkannten Regeln der Technik liegen kann. Erfolgt die Vorgabe einer über den anerkannten Regeln der Technik liegenden Ausführung, ist diese Vorgabe für die Beurteilung der Mangelfreiheit maßgeblich.

Der vom Auftraggeber mit der Planung beauftragte Architekt hat im Rahmen von WU‐Konstruktionen ohne abweichende Vereinbarung immer die sicherste Variante zu planen, bei der er völlig sicher sein kann, dass sie den im Einzelfall zu stellenden Anforderungen genügt.
Wasserundurchlässige Bauwerke aus Beton
Authors: Becker H.‐Rainer , Filusch Sebastian , Frisch Jan , Hohmann Rainer , Horstmann Michael , Kiltz Denis , Krell Jürgen , Krause Jürgen , Zitzelsberger Thomas
Published: February 2018

Für eine erfolgreiche WU‐Konstruktion ist eine besonders hohe Planungs‐ und Ausführungsqualität unabdingbar und eine Überwachung der Ausführung erforderlich. Das vorliegende Positionspapier gibt Hinweise und Hilfestellungen für Bauherren, Planer und Bauausführende für die Planung und Ausführung von WU‐Konstruktionen.
Mitonuclear Mate Choice: A Missing Component of Sexual Selection Theory?
Authors: Hill Geoffrey E.
Published: February 2018

The fitness of a eukaryote hinges on the coordinated function of the products of its nuclear and mitochondrial genomes in achieving oxidative phosphorylation (OXPHOS). I propose that sexual selection plays a key role in the maintenance of mitonuclear coadaptation across generations because it enables pre‐zygotic sorting for coadapted mitonuclear genotypes. At each new generation, sexual reproduction creates new combinations of nuclear and mitochondrial genes, and the potential arises for mitonuclear incompatibilities and reduced fitness. In reviewing the literature, I hypothesize that individuals engaged in mate choice select partners with correct species‐typical mitochondrial and nuclear genotypes as well as individuals with highly functional cellular respiration. The implication is that mate choice for compatible nuclear and mitochondrial genes can play a significant role in generating the patterns of ornamentation and preferences observed in animals. A number of testable predictions emerge from this mitonuclear compatibility hypothesis of sexual selection.
The Eukaryotic CMG Helicase at the Replication Fork: Emerging Architecture Reveals an Unexpected Mechanism
Authors: Li Huilin , O'Donnell Michael E.
Published: February 2018

The eukaryotic helicase is an 11‐subunit machine containing an Mcm2‐7 motor ring that encircles DNA, Cdc45 and the GINS tetramer, referred to as CMG (Cdc45, Mcm2‐7, GINS). CMG is “built” on DNA at origins in two steps. First, two Mcm2‐7 rings are assembled around duplex DNA at origins in G1 phase, forming the Mcm2‐7 “double hexamer.” In a second step, in S phase Cdc45 and GINS are assembled onto each Mcm2‐7 ring, hence producing two CMGs that ultimately form two replication forks that travel in opposite directions. Here, we review recent findings about CMG structure and function. The CMG unwinds the parental duplex and is also the organizing center of the replisome: it binds DNA polymerases and other factors. EM studies reveal a 20‐subunit core replisome with the leading Pol ϵ and lagging Pol α‐primase on opposite faces of CMG, forming a fundamentally asymmetric architecture. Structural studies of CMG at a replication fork reveal unexpected details of how CMG engages the DNA fork. The structures of CMG and the Mcm2‐7 double hexamer on DNA suggest a completely unanticipated process for formation of bidirectional replication forks at origins.
Hybrid coronary revascularization: Time for a new comparator?
Authors: Misumida Naoki , Moliterno David J.
Published: February 2018

Key Points

The present meta‐analysis found no significant difference between hybrid coronary revascularization (HCR) and bypass surgery (CABG) regarding intermediate‐term major adverse cardiac and cerebrovascular events.

HCR is feasible, historically with higher revascularization rates but less perioperative morbidity

With a comparable frequency of repeat revascularization between current‐generation drug‐eluting stents and CABG, future trials of HCR are considering multi‐vessel PCI as the new comparator.
Wanted: Expert operators for coronary chronic total occlusion interventions
Authors: Brilakis Emmanouil S. , Krestyaninov Oleg
Published: February 2018

Key Points

Coronary chronic total occlusions can be recanalized by expert operators with high success and acceptable complication rates.

Developing a procedural plan (using the hybrid or another algorithm) is critical for success. Live case demonstrations appear safe and can be of high educational value.

The key factor for achieving good outcomes in chronic total occlusion interventions remains operator expertise. Development of more expert operators will improve the treatment options for this challenging group of lesions and patients.
Fractional flow reserve guided percutaneous coronary intervention results in reduced ischemic myocardium and improved outcomes
Authors: Sawant Abhishek C. , Bhardwaj Aishwarya , Banerjee Kinjal , Jobanputra Yash , Kumar Arnav , Parikh Parth , Kandregula Krishna C. , Poddar Kanhaiya , Ellis Stephen G. , Nair Ravi , Corbelli John , Kapadia Samir
Published: February 2018

Objectives

To determine if fractional flow reserve guided percutaneous coronary intervention (FFR‐guided PCI) is associated with reduced ischemic myocardium compared with angiography‐guided PCI.

Background

Although FFR‐guided PCI has been shown to improve outcomes, it remains unclear if it reduces the extent of ischemic myocardium at risk compared with angiography‐guided PCI.

Methods

We evaluated 380 patients (190 FFR‐guided PCI cases and 190 propensity‐matched controls) who underwent PCI from 2009 to 2014. Clinical, laboratory, angiographic, stress testing, and major adverse cardiac events [MACE] (all‐cause mortality, recurrence of MI requiring PCI, stroke) data were collected.

Results

Mean age was 63 ± 11 years; the majority of patients were males (76%) and Caucasian (77%). Median duration of follow up was 3.4 [Range: 1.9, 5.0] years. Procedural complications including coronary dissection (2% vs. 0%, P = .12) and perforation (0% vs. 0%, P = 1.00) were similar between FFR‐guided and angiography‐guided PCI patients. FFR‐guided PCI patients had lower unadjusted (14.7% vs. 23.2%, P = .04) and adjusted [OR = 0.58 (95% CI: 0.34–0.98)] risk of repeat revascularization at one year. FFR‐guided PCI patients were less likely (23% vs. 32%, P = .02) to have ischemia and had lower (5.9% vs. 21.1%, P < .001) ischemic burden (moderate‐severe ischemia) on post‐PCI stress testing. Presence of ischemia post‐PCI remained a strong predictor of MACE [OR = 2.14 (95%CI: 1.28–3.60)] with worse survival compared to those without ischemia (HR = 1.63 (95% CI: 1.06–2.51).

Conclusion

Compared with angiography‐guided PCI, FFR‐guided PCI results in less repeat revascularization and a lower incidence of post PCI ischemia translating into improved survival, without an increase in complications.
Gut metabolites associated with pH and antioxidant capacity during in vitro colonic fermentation of Mexican corn products
Authors: Zamora‐Gasga Victor M. , Álvarez‐Vidal Carlos , Montalvo‐González Efigenia , Loarca‐Piña Guadalupe , Vázquez‐Landaverde Pedro A. , Bello‐Pérez Luis A. , Tovar Juscelino , Sáyago‐Ayerdi Sonia G.
Published: February 2018

Background and objectives

Food is the major factor driving the metabolism of the gut microbiota. In Mexico, nixtamalized corn products are widely consumed. Changes in antioxidant capacity (AOX) in 1,1‐Diphenyl‐2‐picrylhydrazyl (DPPH) and Ferric ion reducing antioxidant power (FRAP), pH values, short‐chain fatty acid concentration, and relative metabolite production during in vitro colonic fermentation of indigestible fractions (IF) isolated from Istmo Totopos (ITs), baked corn tortillas (BCTs), and traditional corn tortillas (TCTs) were analyzed.

Findings

The consumption of one piece (10 g) of any corn product may potentially maintain appreciable colonic antioxidant status (above 60 mmol TE) until 48 hr of fermentation. A portion of 10 g of corn products produces similar concentrations of acetic (3,050.43–4,181.47 mM), propionic (1,904.78–2,975.18 mM), and butyric acid (1,458.14–2,873.47 mM) at 12 hr of fermentation. Forty‐six volatile compounds were also detected by solid‐phase microextraction–gas chromatography–mass spectrometry (SPME–GC–MS), and six principal components were identified. Positive correlations were found between DPPH, acetic acid, propionic acid, and butyric acid.

Conclusions

Our results suggest the colonic fermentation potential to increase bioactive compounds and antioxidant activity hence suggesting improved gut health. Additional studies are required to evaluate their in vivo effects.

Significance and novelty

The study of traditional corn products will facilitate a better understanding of the potential health‐promoting impact of the interactions between indigestible components of the Mexican diet and the gut metabolites.
A Novel Post‐Synthesis Modification of CuO‐CeO2 Catalysts: Effect on Their Activity for Selective CO Oxidation
Authors: Papavasiliou Joan , Rawski Michał , Vakros John , Avgouropoulos George
Published: February 2018

Copper oxide nanoparticles were dispersed onto the surface of ceria nanorods, while a post‐synthesis modification was applied to the reference sample using ammonia solutions. The modified catalysts were characterized with a variety of analytical techniques, providing useful information on the effect of the Cu:NH3 ratio, employed in the modification step, on the physicochemical properties. Re‐dispersion of the active copper species under extremely basic conditions promoted the reducibility and the oxygen mobility of the catalyst, thus resulting in a more active and selective catalyst for preferential CO oxidation.
Iron‐Doped Nickel Phosphide Nanosheets In Situ Grown on Nickel Submicrowires as Efficient Electrocatalysts for Oxygen Evolution Reaction
Authors: Chen Jiahui , Li Yunming , Sheng Guoqing , Xu Lu , Ye Huangqing , Fu Xian‐Zhu , Sun Rong , Wong Ching‐Ping
Published: February 2018

Tens of micrometers long metallic Ni submicrowires with a diameter of approximately 200 nm are prepared by a chemical reduction method under a magnetic field. Fe‐doped Ni2P nanosheets are then in situ grown on Ni submicrowires by a simple wet‐chemical reaction followed by a low‐temperature phosphorization process. The (Ni0.87Fe0.13)2P–Ni composite exhibits the highest catalytic activity toward oxygen evolution reaction in alkaline solution among all the as‐prepared (Ni1−xFex)2P–Ni catalysts, delivering a current density of 10 mA cm−2 at an overpotential of only 257 mV and keeping high stability over 10 h electrolysis. These exceptional activities are attributed to the unique structure combining metallic Ni submicrowires as good electronically conductive substrate and the in situ grown Fe‐doped Ni2P nanosheets. Specifically, Fe incorporation leads to strong electron interactions between Ni, Fe, and P, fast reaction kinetics, small charge‐transfer resistance, and a large electrochemical surface area, which are responsible for the excellent catalytic performance.
Controlling Photoconductivity in PBI Films by Supramolecular Assembly
Authors: Draper Emily R. , Archibald Lewis J. , Nolan Michael C. , Schweins Ralf , Zwijnenburg Martijn A. , Sproules Stephen , Adams Dave J.
Published: February 2018

Perylene bisimides (PBIs) self‐assemble in solution. The solubility of the PBIs is commonly changed through the choice of substituents at the imide positions. It is generally assumed this substitution does not affect the electronic properties of the PBI, and that the properties of the self‐assembled aggregate are essentially that of the isolated molecule. However, substituents do affect the self‐assembly, resulting in potentially different packing in the formed aggregates. Here, we show that the photoconductivity of films formed from a library of substituted PBIs varies strongly with the substituent and demonstrate that this is due to the different ways in which they pack. Our results open the possibility for tuning the optoelectronic properties of self‐assembled PBIs by controlling the aggregate structure through careful choice of substituent, as demonstrated by us here optimising the photoconductivity of PBI films in this way.
Study on the HPLC‐based separation of some ezetimibe stereoisomers and the underlying stereorecognition process
Authors: Zhu Bolin , Yao Yaqi , Zhao Yu , Sun Tiemin , Li Qing
Published: February 2018

The enantioseparation of ezetimibe stereoisomers by high‐performance liquid chromatography on different chiral stationary phases, ie, 3 polysaccharide‐based chiral columns, was studied. It was observed that cellulose‐based Chiralpak IC column exhibited the best resolving ability. After the optimization of mobile phase compositions in both normal and reversed phase modes, satisfactory separation could be obtained on Chiralpak IC column, especially in normal phase mode. The use of prohibited solvents as nonstandard mobile phase gave rise to better resolution than that of standard mobile phases (n‐hexane/alcohol system). In addition, the presence of ethanol in nonstandard mobile phase has played an important role in enhancing chromatographic efficiency and resolution between ezetimibe stereoisomers. Various attempts were made to comprehensively compare the chiral recognition capabilities of immobilized versus coated polysaccharide‐based chiral columns, amylose‐based versus cellulose‐based chiral stationary phases, reversed versus normal phase modes, and standard versus nonstandard mobile phases. Moreover, possible solute‐mobile phase‐stationary phase interactions were derived to explain how stationary and mobile phases affected the separation. Then the method validation with respect to selectivity, linearity, precision, accuracy, and robustness was carried out, which was demonstrated to be suitable and accurate for the quantitative determination of (RRS)‐ezetimibe impurity in ezetimibe bulk drug.
Structure–Activity Relationship Studies of Vitamin D3 Analogues Containing an Ether or Thioether Linker as Hedgehog Pathway Inhibitors
Authors: Wen Jiachen , Hadden M. Kyle
Published: February 2018

The Hedgehog (Hh) signaling pathway is critical for embryonic patterning and postembryonic tissue regeneration. Constitutive pathway activation has also been linked to human malignancies such as basal cell carcinoma (BCC) and medulloblastoma; therefore, multiple small‐molecule scaffolds that inhibit Hh signaling are in development. Previously, Grundmann's alcohol, also known as the “northern region” of vitamin D3 (VD3), has been identified as a moderate Hh pathway inhibitor. In this study, isomers of Grundmann's alcohol with different orientations of the C4 hydroxy group and C3α proton were investigated to determine the optimal configuration for this hexahydroindane scaffold with respect to Hh inhibition. A series of analogues containing Grundmann's alcohol linked to a substituted phenyl or benzyl ring through an ether or thioether linker were synthesized and evaluated for their anti‐Hh activity. Of these, analogue 17 ((1R,3aR,4R,7aR)‐1‐[(R)‐1,5‐dimethylhexyl]‐4‐(4‐aminophenoxy)‐7a‐methyloctahydro‐1H‐indene) demonstrated potent anti‐Hh activity in Hh‐dependent BCC cells and did not activate canonical vitamin D receptor signaling, demonstrating its selective nature for the Hh signaling pathway.
How Inert are Osmium−Ligand Bonds? A Combined Thermal, Photochemical and Electrochemical Case Study With a Click Tripodal Ligand
Authors: Klein Johannes , Albold Uta , Suntrup Lisa , Sarkar Biprajit
Published: February 2018

The first examples of osmium(II) complexes of the type [Os(L)(dmso)Cl]+ (L=tripodal ligand) are reported. Photoactivation is shown to be a convenient route for performing ligand substitution reactions in such complexes. Photochemical bond activation works where thermal and electrochemical routes fail. Drastic differences are presented in the reactivity of the Os complexes with the pyridine‐containing ligands versus the triazole‐containing ligands. A detailed experimental and theoretical investigation into photochemical bond activation reactions is presented.
3D Global Heat Transfer Model on Floating Zone for Silicon Single Crystal Growth
Authors: Han Xue‐Feng , Liu Xin , Nakano Satoshi , Harada Hirofumi , Miyamura Yoshiji , Kakimoto Koichi
Published: February 2018

In this paper, a three‐dimensional global heat transfer model to describe the floating zone of silicon single‐crystal growth is proposed. The steady‐state calculations considering argon gas flow, feed rod, silicon melt and crystal are carried out using open source software OpenFOAM with no assumptions of symmetry. From the global calculation, a three dimensional solid‐liquid interface has been obtained. Furthermore, the cooling effect of gas flow in three dimensions is considered, and the three‐dimensional current‐density distribution of the inductor is calculated. By considering the asymmetrical electromagnetic field induced by the inductor, the calculations reveal a deflection of the asymmetrical solid‐liquid interface.
MoS2 Quantum Dots‐Modified Covalent Triazine‐Based Frameworks for Enhanced Photocatalytic Hydrogen Evolution
Authors: Jiang Qianqian , Sun Long , Bi Jinhong , Liang Shijing , Li Liuyi , Yu Yan , Wu Ling
Published: February 2018

MoS2 quantum dots (QDs)‐modified covalent triazine‐based framework (MoS2/CTF) composites are synthesized through an in situ photodeposition method. MoS2 QDs are well distributed and stabilized on the layers of CTFs by coordination of the frameworks to MoS2. The QDs–sheet interactions between MoS2 and CTFs facilitate interfacial charge transfer and separation. As a consequence, the composites exhibit outstanding photocatalytic activity and stability for hydrogen evolution under visible light irradiation (λ≥420 nm), that exceed those over pristine CTFs and MoS2‐modified g‐C3N4 (MoS2/g‐C3N4) composite, making them promising materials for solar energy conversion.