bluuebunny/crossref_metadata_2025 huggingface dataset:
The Rheological Evolution of Brittle‐Ductile Transition Rocks During the Earthquake Cycle: Evidence for a Ductile Precursor to Pseudotachylyte in an Extensional Fault System, South Mountains, Arizona
Authors: Stewart Craig A. , Miranda Elena A.
Published: December 2017

We investigate how the rheological evolution of shear zone rocks from beneath the brittle‐ductile transition (BDT) is affected by coeval ductile shear and pseudotachylyte development associated with seismicity during the earthquake cycle. We focus our study on footwall rocks of the South Mountains core complex, and we use electron backscatter diffraction (EBSD) analyses to examine how strain is localized in granodiorite mylonites both prior to and during pseudotachylyte development beneath the BDT. In mylonites that are host to pseudotachylytes, deformation is partitioned into quartz, where quartz exhibits crystallographic‐preferred orientation patterns and microstructures indicative of dynamic recrystallization during dislocation creep. Grain size reduction during dynamic recrystallization led to the onset of grain boundary sliding (GBS) accommodated by fluid‐assisted grain size‐sensitive (GSS) creep, localizing strain in quartz‐rich layers prior to pseudotachylyte development. The foliation‐parallel zones of GBS in the host mylonites, and the presence of GBS traits in polycrystalline quartz survivor clasts indicate that GBS zones were the ductile precursors to in situ pseudotachylyte generation. During pseudotachylyte development, strain was partitioned into the melt phase, and GSS deformation in the survivor clasts continued until crystallization of melt impeded flow, inducing pseudotachylyte development in other GBS zones. We interpret the coeval pseudotachylytes with ductile precursors as evidence of seismic events near the BDT. Grain size piezometry yields high differential stresses in both host mylonites (~160 MPa) and pseudotachylyte survivor clasts (> ~200 MPa), consistent with high stresses during interseismic and coseismic phases of the earthquake cycle, respectively.
Stress Models of the Annual Hydrospheric, Atmospheric, Thermal, and Tidal Loading Cycles on California Faults: Perturbation of Background Stress and Changes in Seismicity
Authors: Johnson Christopher W. , Fu Yuning , Bürgmann Roland
Published: December 2017

Stresses in the lithosphere arise from multiple natural loading sources that include both surface and body forces. The largest surface loads include near‐surface water storage, snow and ice, atmosphere pressure, ocean loading, and temperature changes. The solid Earth also deforms from celestial body interactions and variations in Earth's rotation. We model the seasonal stress changes in California from 2006 through 2014 for seven different loading sources with annual periods to produce an aggregate stressing history for faults in the study area. Our modeling shows that the annual water loading, atmosphere, temperature, and Earth pole tides are the largest loading sources and should each be evaluated to fully describe seasonal stress changes. In California we find that the hydrological loads are the largest source of seasonal stresses. We explore the seasonal stresses with respect to the background principal stress orientation constrained with regional focal mechanisms and analyze the modulation of seismicity. Our results do not suggest a resolvable seasonal variation for the ambient stress orientation in the shallow crust. When projecting the seasonal stresses into the background stress orientation we find that the timing of microseismicity modestly increases from an ~8 kPa seasonal mean‐normal‐stress perturbation. The results suggest that faults in California are optimally oriented with the background stress field and respond to subsurface pressure changes, possibly due to processes we have not considered in this study. At any time a population of faults are near failure as evident from earthquakes triggered by these slight seasonal stress perturbations.
The Small Effect of Poroelastic Pressure Transients on Triggering of Production‐Induced Earthquakes in the Groningen Natural Gas Field
Authors: Postma Tom , Jansen Jan‐Dirk
Published: December 2017

Over the past decade, a steep increase in the number of seismic events has been observed in the Groningen gas field, the Netherlands. It is generally accepted that these are induced by compaction of the reservoir rock due to extensive depletion, causing a buildup of strain energy in faults that may be released seismically. We address the possible triggering of fault slip by the transient pressure field surrounding a well that has undergone a sudden rate change. Assuming a unilateral decoupling between displacement and pressure, numerical experiments are conducted using a sequential finite volume‐finite element solution strategy that fully incorporates second‐order terms in the radial flow equation. We investigate an idealized Groningen‐like geometry to discover whether the hypothesized possibility of triggering‐induced seismicity exists, explore how some controllable and uncontrollable variables influence its severity, and possibly provide clues on how production strategy might be able to avoid its occurrence. The results demonstrate that sudden production changes can indeed trigger near‐well seismic events, but that the effect is very small compared to other potential causes. Changing from sudden to gradual changes in well rates is therefore not expected to lead to a significant reduction in the number or magnitude of production‐induced earthquakes in the Groningen field.
Hydrothermal Alteration Promotes Humic Acid Formation in Sediments: A Case Study of the Central Indian Ocean Basin
Authors: Sarma Nittala S. , Kiran Rayaprolu , Rama Reddy M. , Iyer Sridhar D. , Peketi A. , Borole D. V. , Krishna M. S.
Published: December 2017

Anomalously high concentrations of humic‐rich dissolved organic matter (DOM) in extant submarine hydrothermal vent plumes traveled far from source are increasingly being reported. This DOM, able to mobilize trace metals (e.g., Fe2+) has been hypothesized as originating from organic matter produced by thermogenic bacteria. To eliminate a possible abiogenic origin of this DOM, study is required of well‐preserved organic compounds that can be attributed to thermogenic bacteria. The Central Indian Ocean Basin (CIOB) is part of a diffuse plate boundary and an intraplate deformation zone. Coarse fraction (>63 µ) characteristics, mineralogy, magnetic susceptibility, and geochemistry were examined in sediments of a core raised close to a north‐south fracture zone near the Equator. Two horizons of distinctly brown‐colored sediments were shown as hydrothermally altered from their charred fragments and geochemistry (CaCO3, Corg, Ti/Al, Al/(Al + Fe + Mn), Sr/Ba, Mg/Li, Mn micronodules, Fe/Mn). We examined whether humic substances were preserved in these sediments, and if so whether their carbon isotope distribution would support their hydrothermal origin. Alkali extraction of sediments afforded humic acids (HA) in yields up to 1.2% in the brown sediments. The remaining portions of the core had nil or low concentrations of HA. The carbon of hydrothermal HA is isotopically heavier (average δ13C, ∼ −16.3‰) compared to nonhydrothermal HA (–18.1‰), suggesting that they were probably formed from organic matter that remained after elimination of lighter carbon enriched functional groups during diagenesis. The results provide compelling evidence of HA formation from lipids originating from thermogenic bacteria.
Changes in Bottom Water Physical Properties Above the Mid‐Atlantic Ridge Flank in the Brazil Basin
Authors: Zhao Jian , Thurnherr Andreas M.
Published: December 2017

Warming of abyssal waters in recent decades has been widely documented around the global ocean. Here repeat hydrographic data collected in 1997 and 2014 near a deep fracture zone canyon in the eastern Brazil Basin are used to quantify the long‐term change. Significant changes are found in the Antarctic Bottom Water (AABW) within the canyon. The AABW in 2014 was warmer (0.08 ± 0.06
), saltier (0.01 ± 0.005), and less dense (0.005 ± 0.004
) than in 1997. In contrast, the change in the North Atlantic Deep Water has complicated spatial structure and is almost indistinguishable from zero at 95% confidence. The resulting divergence in vertical displacement of the isopycnals modifies the local density stratification. At its peak, the local squared buoyancy frequency (
) near the canyon is reduced by about 20% from 1997 to 2014. Similar reduction is found in the basinwide averaged profiles over the Mid‐Atlantic Ridge flank along 25
W in years 1989, 2005, and 2014. The observed changes in density stratification have important implications for internal tide generation and dissipation.
SAR Observation and Numerical Simulation of Internal Solitary Wave Refraction and Reconnection Behind the Dongsha Atoll
Authors: Jia T. , Liang J. J. , Li X.‐M. , Sha J.
Published: December 2017

The refraction and reconnection of internal solitary waves (ISWs) around the Dongsha Atoll (DSA) in the northern South China Sea (SCS) are investigated based on spaceborne synthetic aperture radar (SAR) observations and numerical simulations. In general, a long ISW front propagating from the deep basin of the northern SCS splits into northern and southern branches when it passes the DSA. In this study, the statistics of Envisat Advanced SAR (ASAR) images show that the northern and southern wave branches can reconnect behind the DSA, but the reconnection location varies. A previously developed nonlinear refraction model is set up to simulate the refraction and reconnection of the ISWs behind the DSA, and the model is used to evaluate the effects of ocean stratification, background currents, and incoming ISW characteristics at the DSA on the variation in reconnection locations. The results of the first realistic simulation agree with consecutive TerraSAR‐X (TSX) images captured within 12 h of each other. Further sensitivity simulations show that ocean stratification, background currents, and initial wave amplitudes all affect the phase speeds of wave branches and therefore shift their reconnection locations while shapes and locations of incoming wave branches upstream of the DSA profoundly influence the subsequent propagation paths. This study clarifies the variation in reconnection locations of ISWs downstream of the DSA and reveals the important mechanisms governing the reconnection process, which can improve our understanding of the propagation of ISWs near the DSA.
A Hybrid Multiscale Model of Miscible Reactive Fronts
Authors: Siuliukina Natalia , Tartakovsky Daniel M.
Published: December 2017

Subsurface processes can be simulated at multiple scales with variable degrees of fidelity. Some microscopic (pore‐scale) features of reactive transport cannot be properly resolved in macroscopic (Darcy‐scale) models. While microscopic descriptors might be closer to reality, they are computationally unfeasible when deployed on a macroscale. Hybrid algorithms combine the physical fidelity of a microscopic model with the computational efficiency of its macroscopic counterpart. We develop a hybrid model of dynamic reactive fronts in an open fracture, with a chemical reaction occurring in the zone of contact between two dissolved species. Away from the front, both fluid flow and solute transport are described by one‐dimensional models. In the front's proximity, two‐dimensional Stokes equations are used to model fluid flow, and solute transport is described with advection‐diffusion‐reaction equations. These two descriptors are coupled via an iterative procedure, which enforces the continuity of concentrations and mass fluxes across the interface between the two models. Our numerical experiments demonstrate that the hybrid model outperforms its microscopic and macroscopic counterparts in terms of computational time and representational accuracy, respectively.
Unifying adaptive control with the nonlinear PI methodology: Designs for unknown strict‐feedback nonlinear systems with nonsmooth actuator nonlinearities
Authors: Psillakis H.E. , Lagos A.‐R.
Published: December 2017

In this paper, we extend the nonlinear PI control methodology within an adaptive control framework. An adaptive nonlinear PI controller is proposed for output tracking of strict‐feedback nonlinear systems with nonsmooth actuator nonlinearities and unknown control directions. The current approach relaxes the standard assumption of known bounds for the associated system nonlinearities made in earlier nonlinear PI schemes. New theoretical boundedness results have been proved that enable the successful combination of backstepping and linear parametric approximators with the nonlinear PI approach and ensure semiglobal approximate tracking of the output to some reference trajectory. Following recent extensions of the nonlinear PI method to strict‐feedback systems, the intermediate virtual control laws are derived through suitable integral equations. Simulation results are also presented in this paper that verify our theoretical analysis.
Dynamic catalytic adsorptive desulfurization of real diesel over ultra‐stable and low‐cost silica gel‐supported TiO2
Authors: Ren Xiaoling , Liu Zewei , Dong Lei , Miao Guang , Liao Neng , Li Zhong , Xiao Jing
Published: December 2017

To develop dynamic ultra‐deep catalytic adsorptive desulfurization (CADS) of real diesel using ultra‐stable and low‐cost silica gel‐supported TiO2 is the aim of the work. A two‐stage dynamic breakthrough model was built to describe the CADS process, varied with H/R ratio and O/S ratio. The desulfurization capacity reached 1.3 mg‐S/g‐A at the breakthrough concentration of 5 ppm‐S. Various types of silica gel were screened as the substrate for TiO2, and the textural/acidic properties and CADS capacity were correlated in high relevancy. The effectiveness of diverse oxidants on CADS and the oxidation path were elucidated via combined experiment/simulation. Adsorption enthalpy derived from fitted isotherm data was calculated as 33.4 kJ/mol. The TiO2/silica gel‐based sorbent demonstrated remarkable recyclability/stability in 10 cycles. An effective and economic route to eliminate the trace amount of stubborn sulfur compounds in low‐sulfur diesel is provided, which can be potentially implemented as the final polishing step for ultra‐clean diesel production. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2146–2159, 2018
Part II: Diastereoselective Reactions Involving β‐Mono‐ and β,β′‐Disubstituted Alkylidene Oxindoles: Pondering Alkene Geometry
Authors: Ganesh Madhu , Rao Madhuri P.
Published: December 2017

Part II encompasses synthetic efforts towards the construction of acyclic and cyclic structures that contain carbon and heteroatoms by employing diastereoselective reactions of β,β′‐disubstituted alkylidene oxindole as the primary substrate. In addition to the construction of acyclic structures, carbocyclic and heterocyclic rings that contain three‐, five‐, six‐, and seven‐membered spirocycles or fused‐rings are also described. A few examples of the arylative cyclization of dienes have also been presented.
Rhodium(III)‐Catalyzed Thiolation of Azobenzenes
Authors: Yang Jun , Deng Bowen , Guo Xiaofei , Li Zhengkai , Xiang Haifeng , Zhou Xiangge
Published: December 2017

A rhodium(III)‐catalyzed C−H activation and thiolation of azobenzene with disulfide was developed. A broad range of azobenzenes were thiolated with high regioselectivity to form mono‐ortho‐substituted products in moderate to excellent yields of up to 99 %. The catalytic system could also be applied for the synthesis of a selenylated product and a benzothiophene.
Age estimation in older adults: Use of pulp/tooth ratios calculated from tooth sections
Authors: D'Ortenzio Lori , Prowse Tracy , Inskip Michael , Kahlon Bonnie , Brickley Megan
Published: December 2017

Objectives

Accurate age estimates are foundational for bioarchaeological research, yet the ability to accurately age older adult skeletons remains elusive. This study uses a new version of pulp/tooth area calculations to investigate chronological age of older archaeological individuals.

Materials and Methods

Pulp/tooth area ratios were calculated on modern control teeth (n = 10) that were first radiographed and then sectioned for comparative analysis. Pulp/tooth area ratios were determined on sectioned teeth using ImageJ software for: (a) modern individuals of known age (n = 26); (b) individuals from Belleville, Ontario, Canada (1821–1874) with documented age (n = 50); and (c) Belleville individuals with skeletally estimated age (n = 122).

Results

Calculations from tooth sections on modern teeth (n = 10) resulted in a mean absolute error (MAE) of ±3.9 years, whereas the radiographic method for the same teeth had an MAE of ±14.45 years. Results indicate that sectioned pulp/tooth area ratios are a significant predictor of chronological age (p < .005), with MAEs of ±4.53 years for Belleville and ±3.77 years for modern individuals. There were no statistically significant differences in age estimations between modern and archaeological individuals, or with respect to tooth type, sex, or intra/inter‐observer estimations.

Discussion

This study provides a new more accurate method for estimating age‐at‐death, particularly for individuals in the 50+ age category. Sectioning the teeth and directly measuring exposed pulp chambers results in age estimations that were within ±4.15 years for both modern and archaeological individuals, thus presenting a method that will enhance the ability to age older individuals.
Kontrollierte Polymermikrostruktur in anionischer Polymerisation durch Kompartimentierung
Authors: Rieger Elisabeth , Blankenburg Jan , Grune Eduard , Wagner Manfred , Landfester Katharina , Wurm Frederik R.
Published: December 2017

Eine ideale, statistische anionische Copolymerisation wird durch physikalische Trennung der beiden Monomere in Kompartimente einer Emulsion gezwungen, um so Gradientencopolymere zu bilden. Das eine Monomer (M) ist vorzugsweise in den Tröpfchen löslich, während das andere (D) die kontinuierliche Phase einer DMSO‐in‐Cyclohexan‐Emulsion bevorzugt. Die lebende anionische Copolymerisation von zwei aktivierten Aziridinen ist auf die DMSO‐Kompartimente beschränkt, da die Polymerisation selektiv in diesen Tröpfchen stattfindet. Über die Verdünnung der kontinuierlichen Phase wird die lokale Konzentration von Monomer D in den Tröpfchen bestimmt und folglich der Gradient des resultierenden Copolymers. Die Copolymerisationen in der Emulsion werden durch Echtzeit‐1H‐NMR‐Kinetiken überwacht, was die Änderung der Copolymerisationsparameter beider Monomere bei Verdünnung der kontinuierlichen Phase von ideal statistischen Copolymeren zu Gradientencopolymeren zeigt.
A Flexible Solid Electrolyte Interphase Layer for Long‐Life Lithium Metal Anodes
Authors: Li Nian‐Wu , Shi Yang , Yin Ya‐Xia , Zeng Xian‐Xiang , Li Jin‐Yi , Li Cong‐Ju , Wan Li‐Jun , Wen Rui , Guo Yu‐Guo
Published: December 2017

Lithium (Li) metal is a promising anode material for high‐energy density batteries. However, the unstable and static solid electrolyte interphase (SEI) can be destroyed by the dynamic Li plating/stripping behavior on the Li anode surface, leading to side reactions and Li dendrites growth. Herein, we design a smart Li polyacrylic acid (LiPAA) SEI layer high elasticity to address the dynamic Li plating/stripping processes by self‐adapting interface regulation, which is demonstrated by in situ AFM. With the high binding ability and excellent stability of the LiPAA polymer, the smart SEI can significantly reduce the side reactions and improve battery safety markedly. Stable cycling of 700 h is achieved in the LiPAA‐Li/LiPAA‐Li symmetrical cell. The innovative strategy of self‐adapting SEI design is broadly applicable, providing opportunities for use in Li metal anodes
Evidence for Dynamic Chemical Kinetics at Individual Molecular Ruthenium Catalysts
Authors: Easter Quinn T. , Blum Suzanne A.
Published: December 2017

Catalytic cycles are typically depicted as possessing time‐invariant steps with fixed rates. Yet the true behavior of individual catalysts with respect to time is unknown, hidden by the ensemble averaging inherent to bulk measurements. Evidence is presented for variable chemical kinetics at individual catalysts, with a focus on ring‐opening metathesis polymerization catalyzed by the second‐generation Grubbs’ ruthenium catalyst. Fluorescence microscopy is used to probe the chemical kinetics of the reaction because the technique possesses sufficient sensitivity for the detection of single chemical reactions. Insertion reactions in submicron regions likely occur at groups of many (not single) catalysts, yet not so many that their unique kinetic behavior is ensemble averaged.
Synthese α‐chiraler Ketone und chiraler Alkane durch eine radikalisch/ionische Kreuzungsreaktion von Vinyl‐Bor‐At‐Komplexen
Authors: Gerleve Carolin , Kischkewitz Marvin , Studer Armido
Published: December 2017

Vinyl‐Bor‐At‐Komplexe, hergestellt aus Enantiomeren‐angereicherten Alkylpinakolboronsäureestern, durchlaufen stereospezifische, radikalisch induzierte 1,2‐Wanderungen in radikalisch/ionischen Kreuzungsreaktionen. In dieser Dreikomponentenreaktion können verschiedene kommerziell erhältliche Alkyliodide als Radikalvorstufen verwendet werden, und Licht fungiert als Ketteninitiator. Eine nachfolgende Oxidation oder Protodeborylierung führt zu wertvollen α‐chiralen Ketonen und chiralen Alkanen mit exzellenten Enantiomerenreinheiten.
Reduktive Aminierung durch Photoredoxkatalyse über polaritätsangepassten Wasserstoffatomtransfer
Authors: Guo Xingwei , Wenger Oliver S.
Published: December 2017

Die Anregung eines RuII‐Photosensibilisators in Gegenwart von Ascorbinsäure führt zur Reduktion von Iminium‐Ionen zu elektronenreichen α‐Aminoalkylradikalen, die durch einen thiolvermittelten Wasserstoffatomtransfer (HAT) in Produkte der reduktiven Aminierung umgewandelt werden. Mit diesem Konzept erfolgt die photoredoxkatalytische reduktive Aminierung von Carbonylverbindungen mit Aminen in guten bis hervorragenden Ausbeuten, wobei viele funktionelle Gruppen toleriert werden. Die drei entscheidenden Besonderheiten dieser Arbeit sind: (i) Das schnelle Abfangen elektronenreicher α‐Aminoalkylradikale durch polaritätsangepassten HAT, (ii) die eigentliche Methode der reduktiven Aminierung durch Photoredoxkatalyse und (iii) die Anwendung dieser neuen Methode für zeitlich und räumlich kontrollierte Reaktionen auf festen Trägermaterialen, wie durch das Anbringen eines Fluoreszenzfarbstoffs auf einem aktivierten Celluloseträger durch photoredoxkatalytische reduktive Aminierung veranschaulicht wird.
Photoinduced Cobalt(III)−Trifluoromethyl Bond Activation Enables Arene C−H Trifluoromethylation
Authors: Harris Caleb F. , Kuehner Christopher S. , Bacsa John , Soper Jake D.
Published: December 2017

Visible‐light capture activates a thermodynamically inert CoIII−CF3 bond for direct C−H trifluoromethylation of arenes and heteroarenes. New trifluoromethylcobalt(III) complexes supported by a redox‐active [OCO] pincer ligand were prepared. Coordinating solvents, such as MeCN, afford green, quasi‐octahedral [(SOCO)CoIII(CF3)(MeCN)2] (2), but in non‐coordinating solvents the complex is red, square pyramidal [(SOCO)CoIII(CF3)(MeCN)] (3). Both are thermally stable, and 2 is stable in light. But exposure of 3 to low‐energy light results in facile homolysis of the CoIII−CF3 bond, releasing .CF3 radical, which is efficiently trapped by TEMPO. or (hetero)arenes. The homolytic aromatic substitution reactions do not require a sacrificial or substrate‐derived oxidant because the CoII by‐product of CoIII−CF3 homolysis produces H2. The photophysical properties of 2 and 3 provide a rationale for the disparate light stability.
Bis(perchlorocatecholato)silane—A Neutral Silicon Lewis Super Acid
Authors: Maskey Rezisha , Schädler Marcel , Legler Claudia , Greb Lutz
Published: December 2017

No neutral silicon Lewis super acids are known to date. We report on the synthesis of bis(perchlorocatecholato)silane and verify its Lewis super acidity by computation (DLPNO‐CCSD(T)) and experiment (fluoride abstraction from SbF6−). The exceptional affinity towards donors is further demonstrated by, for example, the characterization of an unprecedented SiO4F2 dianion and applied in the first hydrodefluorination reaction catalyzed by a neutral silicon Lewis acid. Given the strength and convenient access to this new Lewis acid, versatile applications might be foreseen.
Design and characterization of Dendrimer of MNPs as a novel, heterogeneous and reusable nanomagnetic organometallic catalyst for one‐pot synthesis of hydroxyl naphthalene‐1,4‐dione derivatives under solvent‐free conditions
Authors: Mollazehi Fouziyeh , Shaterian Hamid Reza
Published: December 2017

A novel super acidic magnetic nanoparticle as catalyst was successfully synthesized. The preparation of this dendrimer sulfonic acid functionalized γ‐Fe2O3 magnetic core‐shell silica nanoparticles as a new recoverable and heterogeneous nanocatalyst was described. The new catalyst was characterized using various techniques such as scanning electron microscopy (SEM), energy dispersive spectrum (EDS), and thermo gravimetric synthesis (TGA). Moreover, we have examined the catalytic activity of the catalyst for one‐pot, efficient and facile synthesis of 2‐hydroxy‐1,4‐naphthoquinone derivatives via a three‐component condensation reaction of 2‐hydroxynaphthalene‐1,4‐dione, aromatic aldehydes and aniline derivatives. High yields of products, short reaction times, waste‐free, mild, ambient and solvent‐free reaction conditions are advantages of this protocol. Also, the catalyst can be easily recovered by an external magnetic and reused several times without significant loss of its catalytic activity.
Assessment of degradation of plasticized poly(vinyl chloride) films through polyene formation under isothermal conditions
Authors: Tüzüm Demir A. P. , Ulutan S.
Published: December 2017

The aim of this work is to assess the degradation of flexible poly(vinyl chloride) (PVC) films produced using orthophthalate based and recently introduced nonorthophthlate plasticizers which have compliance with recent environmental regulations. The plasticized PVC films were subjected to several heat treatments at 85–160 °C up to 420 min. Ultraviolet–visible spectroscopy was utilized to follow polyene formation upon dehydrochlorination of PVC. The amount of polyenes formed exhibited difference amongst the films those plasticized with diethyl hexylphthalate, diisodecyl phthalate, dioctyl terephthalate (DOTP), and diisononyl 1,2‐cyclohexanedicarboxylic acid (DINCH). The order of polyene concentration formed at the utmost level severe heat treatment is in line with the molecular weight ranking from highest to lowest, as the films with diisodecyl phthalate > DINCH > DOTP > diethyl hexylphthalate. Discoloration assessed in terms of yellowness index revealed that the films having recently introduced plasticizers as DOTP and DINCH were competing well with the films having orthophthalate based plasticizers. Scanning electron microscopy images revealed that the longer times for gelation during their production would improve the maturation of the films although they are already coherent and strong. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci.2018,135, 46092.
A comprehensive status, phylogenetic, and anatomical review of Stagnicola caperata (Say, 1829) in the south‐west United States
Authors: Morningstar Cayla R. , Inoue Kentaro , Lang Brian K. , Berg David J.
Published: December 2017

Freshwater gastropods are a major component of aquatic communities in arid regions. The isolation of aquatic habitats and poor dispersal abilities of organisms has resulted in the evolution of endemic species with small ranges. Human demands for water threaten the integrity of desert spring systems and as a result many freshwater snails from these regions are of conservation concern.

One widespread lymnaeid species in North America, Stagnicola caperata (Say, ), exhibits distinct shell morphologies among populations in the south‐west United States. Because S. caperata is listed as endangered by the State of New Mexico owing to degradation of wetland habitats, accurate taxonomic assessment among populations is required in order to understand threats to the survival of this taxon. A holistic approach (morphometrics, phylogenetics, and reproductive anatomy) was used to investigate the taxonomic affinities of S. caperata in the south‐west United States by comparing these populations with topotypes.

Morphometric analyses revealed similar levels of variation among populations, with large overlaps in shell morphologies. Both phylogenetic analysis and reproductive anatomy revealed the presence of two Stagnicola species in these populations: all populations except the Big Costilla Peak (BCP) population were referable to the nomen S. caperata, while BCP was Stagnicola cf. elodes.

A total‐evidence approach that combines genetic and morphological data facilitates assessment of taxonomic affinities. The results provide conservation agencies with information necessary to detect species boundaries and then develop effective conservation and recovery plans for imperilled species.
Alien turf: Overfishing, overgrazing and invader domination in south‐eastern Levant reef ecosystems
Authors: Rilov Gil , Peleg Ohad , Yeruham Erez , Garval Tal , Vichik Ania , Raveh Ofrat
Published: December 2017

Coastal reefs are highly diverse marine ecosystems that in many regions suffer today from growing pressures by human activities. Among the most highly‐stressed are those found in the Levantine basin (south‐eastern Mediterranean Sea). The Levant represents the trailing‐edge of distribution of native species where they are exposed to the most extreme temperature and salinity conditions, and the region is also fast‐warming and exposed to a great many alien species and strong fishing pressure. In this study, the ecological state of reefs in the south‐eastern Levant was assessed quantitatively (including inside a small marine reserve) using current, extensive, survey data with reference to anecdotal historical information on their more pristine past.

The results of very extensive subtidal community surveys that were conducted in north Israel indicate that reefs in this area are currently dominated by turf‐forming algae and aliens, and sustain low numbers of top predators. Specifically, it was found that on these Levant reefs: (1) commercial species represent a very small part of the fish assemblage (except inside the reserve); (2) alien species constitute a considerable portion (23–44%) of the fish assemblage (including in the reserve) and 95–99% of epi‐benthic molluscs, including inside the marine reserve; and (3) turf barrens are the dominant substrate cover, while cover of native brown algae canopy is limited to small patches occurring only during winter and spring.

These findings suggest that the Levant reefs have been highly transformed by overfishing and alien invasions, and probably also climate change, and that even well managed marine reserves had little effect on alien species presence. From a biogeographic‐conservation perspective, as both warming and bioinvasions continue in the Mediterranean, it is expected that this degraded reef state will gradually advance westward. Alleviating fishing pressure with marine reserves might make the reefs more resilient to these regional pressures, but alien invaders will remain a dominant feature in the system. Therefore, a more realistic conservation target might be the preservation or restoration of ecosystem functions rather than the original native biodiversity.
The effect of prediscussion note‐taking in hidden profile tasks
Authors: Zhou Hao , Xiao Lu , Liu Yongmei , Chen Xiaohong
Published: December 2017

Prior research has discovered that groups tend to discuss shared information while failing to discuss unique information in decision‐making processes. In our study, we conducted a lab experiment to examine the effect of prediscussion note‐taking on this phenomenon. The experiment used a murder‐mystery hidden profile task. In all, 192 undergraduate students were recruited and randomly assigned into 48 four‐person groups with gender being the matching variable (i.e., each group consisted of four same‐gender participants). During the decision‐making processes, some groups were asked to take notes while reading task materials and had their notes available in the following group discussion, while the other groups were not given this opportunity. Our analysis results suggest that (a) the presence of an information piece in group members' notes positively correlates with its appearance in the subsequent discussion and note‐taking positively affects the group's information repetition rate; (b) group decision quality positively correlates with the group's information sampling rate and negatively correlates with the group's information sampling/repetition bias; and (c) gender has no statistically significant moderating effect on the relationship between note‐taking and information sharing. These results imply that prediscussion note‐taking could facilitate information sharing but could not alleviate the biased information pooling in hidden profile tasks.
Human UGT2B7 is the major isoform responsible for the glucuronidation of clopidogrel carboxylate
Authors: Ji Jin‐Zi , Huang Bei‐Bei , Gu Tong‐Tong , Tai Ting , Zhou Huan , Jia Yu‐Meng , Mi Qiong‐Yu , Zhang Meng‐Ran , Xie Hong‐Guang
Published: December 2017

Clopidogrel is predominantly hydrolyzed to clopidogrel carboxylic acid (CCA) by carboxylesterase 1, and subsequently CCA is glucuronidated to clopidogrel acyl glucuronide (CAG) by uridine diphosphate‐glucuronosyltransferases (UGTs); however, the UGT isoenzymes glucuronidating CCA remain unidentified to date. In this study, the glucuronidation of CCA was screened with pooled human liver microsomes (HLMs) and 7 human recombinant UGT (rUGT) isoforms. Results indicated that rUGT2B7 exhibited the highest catalytical activity for the CCA glucuronidation as measured with a mean Vmax value of 120.9 pmol/min/mg protein, 3‐ to 12‐fold higher than that of the other rUGT isoforms tested. According to relative activity factor approach, the relative contribution of rUGT2B7 to CCA glucuronidation was estimated to be 58.6%, with the minor contributions (3%) from rUGT1A9. Moreover, the glucuronidation of CCA followed Michaelis‐Menten kinetics with a mean Km value of 372.9 μM and 296.4 μM for pooled HLMs and rUGT2B7, respectively, showing similar affinity for both. The formation of CAG was significantly inhibited by azidothymidine and gemfibrozil (well‐characterized UGT2B7 substrates) in a concentration‐dependent manner, or by fluconazole (a typical UGT2B7‐selective inhibitor) in a time‐dependent manner, for both HLMs and rUGT2B7, respectively. In addition, CCA inhibited azidothymidine glucuronidation (catalyzed almost exclusively by UGT2B7) by HLMs and rUGT2B7 in a concentration‐dependent manner, indicating that CCA is a substrate of UGT2B7. These results reveal that UGT2B7 is the major enzyme catalyzing clopidogrel glucuronidation in the human liver, and that there is the potential for drug‐drug interactions between clopidogrel and the other substrate drugs of UGT2B7.
Modeling electron competition among nitrogen oxides reduction and N2O accumulation in hydrogenotrophic denitrification
Authors: Liu Yiwen , Ngo Huu H. , Guo Wenshan , Peng Lai , Chen Xueming , Wang Dongbo , Pan Yuting , Ni Bing‐Jie
Published: December 2017

Hydrogenotrophic denitrification is a novel and sustainable process for nitrogen removal, which utilizes hydrogen as electron donor, and carbon dioxide as carbon source. Recent studies have shown that nitrous oxide (N2O), a highly undesirable intermediate and potent greenhouse gas, can accumulate during this process. In this work, a new mathematical model is developed to describe nitrogen oxides dynamics, especially N2O, during hydrogenotrophic denitrification for the first time. The model describes electron competition among the four steps of hydrogenotrophic denitrification through decoupling hydrogen oxidation and nitrogen reduction processes using electron carriers, in contrast to the existing models that couple these two processes and also do not consider N2O accumulation. The developed model satisfactorily describes experimental data on nitrogen oxides dynamics obtained from two independent hydrogenotrophic denitrifying cultures under various hydrogen and nitrogen oxides supplying conditions, suggesting the validity and applicability of the model. The results indicated that N2O accumulation would not be intensified under hydrogen limiting conditions, due to the higher electron competition capacity of N2O reduction in comparison to nitrate and nitrite reduction during hydrogenotrophic denitrification. The model is expected to enhance our understanding of the process during hydrogenotrophic denitrification and the ability to predict N2O accumulation.
Metabolic characterization of anaerobic fungi provides a path forward for bioprocessing of crude lignocellulose
Authors: Henske John K. , Wilken St. Elmo , Solomon Kevin V. , Smallwood Chuck R. , Shutthanandan Vaithiyalingam , Evans James E. , Theodorou Michael K. , O'Malley Michelle A.
Published: December 2017

The conversion of lignocellulose‐rich biomass to bio‐based chemicals and higher order fuels remains a grand challenge, as single‐microbe approaches often cannot drive both deconstruction and chemical production steps. In contrast, consortia based bioprocessing leverages the strengths of different microbes to distribute metabolic loads and achieve process synergy, product diversity, and bolster yields. Here, we describe a biphasic fermentation scheme that combines the lignocellulolytic action of anaerobic fungi isolated from large herbivores with domesticated microbes for bioproduction. When grown in batch culture, anaerobic fungi release excess sugars from both cellulose and crude biomass due to a wealth of highly expressed carbohydrate active enzymes (CAZymes), converting as much as 49% of cellulose to free glucose. This sugar‐rich hydrolysate readily supports growth of Saccharomyces cerevisiae, which can be engineered to produce a range of value‐added chemicals. Further, construction of metabolic pathways from transcriptomic data reveals that anaerobic fungi do not catabolize all sugars that their enzymes hydrolyze from biomass, leaving other carbohydrates such as galactose, arabinose, and mannose available as nutritional links to other microbes in their consortium. Although basal expression of CAZymes in anaerobic fungi is high, it is drastically amplified by cellobiose breakout products encountered during biomass hydrolysis. Overall, these results suggest that anaerobic fungi provide a nutritional benefit to the rumen microbiome, which can be harnessed to design synthetic microbial communities that compartmentalize biomass degradation and bioproduct formation.
Advances in applications of rhamnolipids biosurfactant in environmental remediation: A review
Authors: Liu Guansheng , Zhong Hua , Yang Xin , Liu Yang , Shao Binbin , Liu Zhifeng
Published: December 2017

The objective of this review is to provide a comprehensive overview of the advances in the applications of rhamnolipids biosurfactants in soil and ground water remediation for removal of petroleum hydrocarbon and heavy metal contaminants. The properties of rhamnolipids associated with the contaminant removal, that is, solubilization, emulsification, dispersion, foaming, wetting, complexation, and the ability to modify bacterial cell surface properties, were reviewed in the first place. Then current remediation technologies with integration of rhamnolipid were summarized, and the effects and mechanisms for rhamnolipid to facilitate contaminant removal for these technologies were discussed. Finally rhamnolipid‐based methods for remediation of the sites co‐contaminated by petroleum hydrocarbons and heavy metals were presented and discussed. The review is expected to enhance our understanding on environmental aspects of rhamnolipid and provide some important information to guide the extending use of this fascinating chemical in remediation applications.
1H NMR Based Metabolomics Studies of the Toxicity of Titanium Dioxide Nanoparticles in Zebrafish (Danio rerio)
Authors: Raja Ganesan , Kim Siwon , Yoon Dahye , Yoon Changshin , Kim Suhkmann
Published: December 2017

Titanium dioxide nanoparticles (TiO2‐NPs) are widely used in foods, cosmetics, and pharmaceuticals. In the present study, male and female zebrafish (Danio rerio) were exposed to sub‐lethal concentrations of TiO2‐NPs dosed at 0.1 mg/L (low) and 5.0 mg/L (high), respectively. 1H–nuclear magnetic resonance (NMR) profiling combined with univariate and multivariate statistics was used to assess metabolic alterations in the TiO2‐NP‐treated fish. Purine metabolism—including the anabolism/catabolism of ATP, ADP, AMP, xanthine, and inosine—was significantly influenced, which may indicate some genotoxicity resulting from TiO2‐NP exposure. Increasing the dose and duration of TiO2‐NP exposure led to additional metabolic disturbances in glycerophospholipid metabolism and the Krebs cycle. Our findings demonstrate the potential applicability of using a metabolomics approach to determine underlying metabolic disturbances caused by TiO2‐NPs.
Chromatographic methods in HIV medicine: Application to therapeutic drug monitoring
Authors: Archibald Timothy L. , Murrell Derek E. , Brown Stacy D.
Published: December 2017

HIV antiretroviral therapy spans several different drug classes, meant to combat various aspects of viral infection and replication. Many authors have argued the benefits of therapeutic drug monitoring (TDM) for the HIV patient including compliance assurance and assessment of appropriate drug concentrations; however, the array of drug chemistries and combinations makes TDM an arduous task. HPLC‐UV and LC‐MS/MS are both frequent instruments for the quantification of HIV drugs in biological matrices with investigators striving to balance sensitivity and affordability. Plasma, the dominant matrix for these analyses, is prepared using protein precipitation, liquid–liquid extraction or solid‐phase extraction depending on the specific complement of analytes. Despite the range of polarities found in drug classes relevant to HIV therapeutics, most chromatographic separations utilize a hydrophobic column (C18). Additionally, as the clinically relevant samples for these assays are infected with HIV, along with possible co‐infections, another important aspect of sample preparation concerns viral inactivation. Although not routine in clinical practice, many published analytical methods from the previous two decades have demonstrated the ability to conduct TDM in HIV patients receiving various medicinal combinations. This review summarizes the analytical methods relevant to TDM of HIV drugs, while highlighting respective challenges.
SMG‐1 inhibition by miR‐192/‐215 causes epithelial‐mesenchymal transition in gastric carcinogenesis via activation of Wnt signaling
Authors: Zhang Xiaojing , Peng Yin , Huang Yong , Yang Mengting , Yan Ruibin , Zhao Yanqiu , Cheng Yulan , Liu Xi , Deng Shiqi , Feng Xianling , Lin Huijuan , Yu Huimin , Chen Si , Zhao Zhenfu , Li Shanni , Li Kuan , Wang Liang , Wei Yanjie , He Zhendan , Fan Xinmin , Meltzer Stephen J. , Li Song , Jin Zhe
Published: December 2017

SMG‐1,a member of the phosphoinositide kinase‐like kinase family, functioned as a tumor suppressor gene. However, the role of SMG‐1 in GC remain uncharacterized. In this study, regulation of SMG‐1 by miR‐192 and‐215, along with the biological effects of this modulation, were studied in GC. We used gene microarrays to screening and luciferase reporter assays were to verify the potential targets of miR‐192 and‐215. Tissue microarrays analyses were applied to measure the levels of SMG‐1 in GC tissues. Western blot assays were used to assess the signaling pathway of SMG‐1 regulated by miR‐192 and‐215 in GC. SMG‐1 was significantly downregulated in GC tissues.The proliferative and invasive properties of GC cells were decreased by inhibition of miR‐192 and‐215, whereas an SMG‐1siRNA rescued the inhibitory effects. Finally, SMG‐1 inhibition by miR‐192 and‐215 primed Wnt signaling and induced EMT. Wnt signaling pathway proteins were decreased markedly by inhibitors of miR‐192 and‐215, while SMG‐1 siRNA reversed the inhibition apparently. Meanwhile, miR‐192 and‐215 inhitibtors increased E‐cadherin expression and decreased N‐cadherin and cotransfection of SMG‐1 siRNA reversed these effects. In summary, these findings illustrate that SMG‐1 is suppressed by miR‐192 and‐215 and functions as a tumor suppressor in GC by inactivating Wnt signaling and suppressing EMT.
BTG2 is a tumor suppressor gene upregulated by p53 and PTEN in human bladder carcinoma cells
Authors: Tsui Ke‐Hung , Chiang Kun‐Chun , Lin Yu‐Hsiang , Chang Kang‐Shuo , Feng Tsui‐Hsia , Juang Horng‐Heng
Published: December 2017

Although widely deemed as a tumor suppressor gene, the role of B‐cell translocation gene 2 (BTG2) in bladder cancer is still inconclusive. We investigated the role and regulatory mechanism of BTG2 in bladder cancer. BTG2 expression in human bladder tissues was determined by RT‐qPCR and immunoblotting assays. Expressions of BTG2 and PTEN in bladder carcinoma cells were determined by immunoblotting, RT‐qPCR, or reporter assays. The 3H‐thymidine incorporation assay, flow cytometry, and the xenograft animal model were used to determine the cell growth. BTG2 expression was lower in human bladder cancer tissues than normal bladder tissues. Highly differentiated bladder cancer cells, RT4, expressed higher BTG2 than the less‐differentiated bladder cancer cells, HT1376 and T24. Overexpression of BTG2 in T24 cells inhibited cell growth in vitro and in vivo. Camptothecin and doxorubicin treatments in RT‐4 cells or transient overexpression of p53 into p53‐mutant HT1376 cells induced p53 and BTG2 expression. Further reporter assays with site‐mutation of p53 response element from GGGAAAGTCC to GGAGTCC within BTG2 promoter area showed that p53‐induced BTG2 gene expression was dependent on the p53 response element. Ectopic PTEN overexpression in T24 cells blocked the Akt signal pathway which attenuated cell growth via upregualtion of BTG2 gene expression, while reverse effect was found in PTEN‐knockdown RT‐4 cells. PTEN activity inhibitor (VO‐OHpic) treatment decreased BTG2 expression in RT‐4 and PTEN‐overexpressed T24 cells. Our results suggested that BTG2 functioned as a bladder cancer tumor suppressor gene, and was induced by p53 and PTEN. Modulation of BTG2 expression seems a promising way to treat human bladder cancer.
New 4‐Amino‐1,2,3‐Triazole Inhibitors of Indoleamine 2,3‐Dioxygenase Form a Long‐Lived Complex with the Enzyme and Display Exquisite Cellular Potency
Authors: Alexandre Julie Anne Christine , Swan Michael Kenneth , Latchem Mike John , Boyall Dean , Pollard John Robert , Hughes Stuart Wynn , Westcott James
Published: December 2017

Indoleamine‐2,3 dioxygenase 1 (IDO1) has emerged as a central regulator of immune responses in both normal and disease biology. Due to its established role in promoting tumour immune escape, IDO1 has become an attractive target for cancer treatment. A novel series of highly cell potent IDO1 inhibitors based on a 4‐amino‐1,2,3‐triazole core have been identified. Comprehensive kinetic, biochemical and structural studies demonstrate that compounds from this series have a noncompetitive kinetic mechanism of action with respect to the tryptophan substrate. In co‐complex crystal structures, the compounds bind in the tryptophan pocket and make a direct ligand interaction with the haem iron of the porphyrin cofactor. It is proposed that these data can be rationalised by an ordered‐binding mechanism, in which the inhibitor binds an apo form of the enzyme that is not competent to bind tryptophan. These inhibitors also form a very tight, long‐lived complex with the enzyme, which partially explains their exquisite cellular potency. This novel series represents an attractive starting point for the future development of potent IDO1‐targeted drugs.