bluuebunny/crossref_metadata_2025 huggingface dataset:
An Active Seismic Zone in Intraplate West Iberia Inferred From High‐Resolution Geophysical Data
Authors: Matos Catarina , Custódio Susana , Batló Josep , Zahradník Jiří , Arroucau Pierre , Silveira Graça , Heimann Sebastian
Published: February 2018

Intraplate Iberia is a region of slow lithopsheric deformation (<1 mm/yr) with significant historical earthquake activity. Recent high‐quality instrumental data have shown that small‐magnitude earthquakes collapse along clusters and lineaments, which however do not bear a clear relationship to geologically mapped active structures. In this article, we investigate the controls of these earthquake clusters. In particular, we study two of the identified clusters—the Arraiolos and the Évora seismic zones (ASZ and ESZ), located in the Western Ossa Morena Zone, southwest Iberia. The ASZ marks a sharp boundary between a seismically active region to its south and a more quiet region to its north. We revise historical earthquakes in order to clarify whether earthquake activity in the region is persistent. We use data from a local network to compute accurate epicenters, focal depth, focal mechanisms, and spatiotemporal clustering, thus characterizing ongoing small‐scale fracturing. Finally, we analyze complementary data sets, including tomographic models, Global Navigation Satellite Systems data, magnetic anomalies, and gravity anomalies, in order to discuss the factors that control seismogenesis in the two seismic zones. Consistency between earthquake locations, focal mechanisms and Global Navigation Satellite Systems data suggests that the ASZ is an active right‐lateral shear zone, which divides two blocks within the Western Ossa Morena Zone. The ESZ seems to localize microseismicity due to its granitic lithology. These results suggest that high‐resolution geophysical data have the potential to reveal blocks with different seismogenic and rheological behaviors, which may be used to improve our understanding of fault systems and the assessment of earthquake hazard in slowly deforming regions.
Sensitivities of Near‐field Tsunami Forecasts to Megathrust Deformation Predictions
Authors: Tung S. , Masterlark T.
Published: February 2018

This study reveals how modeling configurations of forward and inverse analyses of coseismic deformation data influence the estimations of seismic and tsunami sources. We illuminate how the predictions of near‐field tsunami change when (1) a heterogeneous (HET) distribution of crustal material is introduced to the elastic dislocation model, and (2) the near‐trench rupture is either encouraged or suppressed to invert spontaneous coseismic displacements. Hypothetical scenarios of megathrust earthquakes are studied with synthetic Global Positioning System displacements in Cascadia. Finite‐element models are designed to mimic the subsurface heterogeneity across the curved subduction margin. The HET lithospheric domain modifies the seafloor displacement field and alters tsunami predictions from those of a homogeneous (HOM) crust. Uncertainties persist as the inverse analyses of geodetic data produce nonrealistic slip artifacts over the HOM domain, which propagates into the prediction errors of subsequent tsunami arrival and amplitudes. A stochastic analysis further shows that the uncertainties of seismic tomography models do not degrade the solution accuracy of HET over HOM. Whether the source ruptures near the trench also controls the details of the seafloor disturbance. Deeper subsurface slips induce more seafloor uplift near the coast and cause an earlier arrival of tsunami waves than surface‐slipping events. We suggest using the solutions of zero‐updip‐slip and zero‐updip‐slip‐gradient rupture boundary conditions as end‐members to constrain the tsunami behavior for forecasting purposes. The findings are important for the near‐field tsunami warning that primarily relies on the near‐real‐time geodetic or seismic data for source calibration before megawaves hit the nearest shore upon tsunamigenic events.
Deep Long‐Period Earthquakes Beneath Mount St. Helens: Their Relationship to Tidal Stress, Episodic Tremor and Slip, and Regular Earthquakes
Authors: Han Jiangang , Vidale John E. , Houston Heidi , Schmidt David A. , Creager Kenneth C.
Published: February 2018

Volcanic deep long‐period earthquakes (DLPs) have been observed for a long time but remain poorly understood. In this study, 22 catalog DLPs were taken as templates to search for repeating events at Mount St. Helens. During the period from 2007 to 2016, we have detected 277 DLPs. Three templates are isolated DLPs, while all other templates produced matches, identifying loci of repeated activity. Overall, the DLPs show no significant correlation with either the timing of the subduction zone tremor and slow slip west of Mount St. Helens, or the shallow seismicity, or distant earthquakes. Temporal analysis shows an elevated rate of DLPs at times of compressional volumetric tidal stress, suggesting a possible association with magmatic and/or fluid activity. We also observed variable S wave polarization of the DLPs in the most productive DLP source region, indicating source mechanisms are not identical despite the waveform similarity that allowed their detection.
Constructing Synthetic Ecosystems with Biopolymer Fluitrodes
Authors: Pham Phu L. H. , Rooholghodos Seyed A. , Choy John S. , Luo Xiaolong
Published: February 2018

Modeling the complex interactions among organisms found within microbiomes is of great interest for the development of new biological technologies. Challenges remain in culturing cells of multiple species with spatial resolutions similar to microbial communities. Here, a fluitrode concept in microfluidics using biofabrication of functional biopolymers is demonstrated to efficiently assemble multiple cell populations in 3D hydrogels of spatial and biological relevance. The fluitrodes are freestanding biopolymer membranes that, similar to electrodes in transmitting electrons, transmit ions and small molecules with spatiotemporal programmability. The individually addressable fluitrodes allow for controlled delivery of nutrients and chemical molecules of interest in situ, live imaging of biological events, effluent collection to perform ex situ diagnostics, and finally, release of cells for downstream molecular and biochemical analyses. This novel coculturing platform can model in vitro ecosystems comprised of multiple species or kingdoms to elucidate cell–cell interactions in complex communities and aid in high throughput screening for drug discovery.
Structuring of Hydrogels across Multiple Length Scales for Biomedical Applications
Authors: Cooke Megan E. , Jones Simon W. , ter Horst Britt , Moiemen Naiem , Snow Martyn , Chouhan Gurpreet , Hill Lisa J. , Esmaeli Maryam , Moakes Richard J. A. , Holton James , Nandra Rajpal , Williams Richard L. , Smith Alan M. , Grover Liam M.
Published: February 2018

The development of new materials for clinical use is limited by an onerous regulatory framework, which means that taking a completely new material into the clinic can make translation economically unfeasible. One way to get around this issue is to structure materials that are already approved by the regulator, such that they exhibit very distinct physical properties and can be used in a broader range of clinical applications. Here, the focus is on the structuring of soft materials at multiple length scales by modifying processing conditions. By applying shear to newly forming materials, it is possible to trigger molecular reorganization of polymer chains, such that they aggregate to form particles and ribbon‐like structures. These structures then weakly interact at zero shear forming a solid‐like material. The resulting self‐healing network is of particular use for a range of different biomedical applications. How these materials are used to allow the delivery of therapeutic entities (cells and proteins) and as a support for additive layer manufacturing of larger‐scale tissue constructs is discussed. This technology enables the development of a range of novel materials and structures for tissue augmentation and regeneration.
Structural Engineering of 2D Nanomaterials for Energy Storage and Catalysis
Authors: Zhu Yue , Peng Lele , Fang Zhiwei , Yan Chunshuang , Zhang Xiao , Yu Guihua
Published: February 2018

Research on 2D nanomaterials is rising to an unprecedented height and will continue to remain a very important topic in materials science. In parallel with the discovery of new candidate materials and exploration of their unique characteristics, there are intensive interests to rationally control and tune the properties of 2D nanomaterials in a predictable manner. Considerable attention is focused on modifying these materials structurally or engineering them into designed architectures to meet requirements for specific applications. Recent advances in such structural engineering strategies have demonstrated their ability to overcome current material limitations, showing great promise for promoting device performance to a new level in many energy‐related applications. Existing in many forms, these strategies can be categorized based on how they intrinsically or extrinsically alter the pristine structure. Achieved through various synthetic routes and practiced in a range of different material systems, they usually share common descriptors that predestine them to be effective in certain circumstances. Therefore, understanding the underlying mechanism of these strategies to provide fundamental insights into structural design and property tailoring is of critical importance. Here, the most recent development of structural engineering of 2D nanomaterials and their significant effects in energy storage and catalysis technologies are addressed.
Plasmon‐Dictated Photo‐Electrochemical Water Splitting for Solar‐to‐Chemical Energy Conversion: Current Status and Future Perspectives
Authors: Xiao Fang‐Xing , Liu Bin
Published: February 2018

Surface plasmon resonance (SPR) effect of metal nanostructures is established as an efficient and attractive strategy to boost visible‐light or even near‐infrared‐responsive photo‐electrochemical (PEC) water splitting devices for substantial solar‐to‐chemical energy conversion. Rational integration of plasmonic metal nanostructures with semiconductors in an appropriate fashion is beneficial for creating a large variety of plasmonic metal/semiconductor photoelectrodes. However, up to date, construction of well‐defined and highly efficient plasmonic metal/semiconductor heterostructures is still in its infant stage. In this review, basic principles of PEC water splitting over semiconductors, SPR‐excited plasmonic effect of metal nanostructures, and their intrinsic correlation with each other are first concisely introduced. Subsequently, it is paid great attention to specifically summarize the diverse plasmonic metal/semiconductor photoelectrodes currently being extensively explored for indirect plasmon‐induced PEC water splitting. Particularly, different plasmonic metal/semiconductor nanoarchitectures including planar thin films, 1D composited, and 3D spatially hierarchical heterostructures are systematically classified and elucidated. Finally, future perspectives and challenges in triggering further innovative thinking on plasmon‐enhanced solar water splitting are envisaged. It is anticipated that this review can provide enriched information on rational design and construction of various plasmonic metal/semiconductor heterostructures for solar‐powered plasmon‐based PEC devices.
Functionalizing New Intercalation Chemistry for Sub‐Nanometer‐Scaled Interlayer Engineering of 2D Transition Metal Oxides and Chalcogenides
Authors: Hai Zhenyin , Zhuiykov Serge
Published: February 2018

Intercalation in bulk layered materials has been investigated intensively in the last 60 years. However, the rise of 2D few‐layered nanomaterials such as transition metal oxides and chalcogenides opened up thrilling opportunities for the new era of intercalation as it is almost guaranteed that new phenomena will be observed with the intercalation of ions and molecules into few‐layered nanomaterials due to the quantum confinement effect at the 2D scale. In this progress report, the advances of the 2D intercalation chemistry in the few‐layered oxides and chalcogenides of molybdenum and tungsten are highlighted with respect to its concept, structure, implementation, identification, property modulation, and applications. The perspective and outlook concerning its current obstacles and future opportunities are addressed. The 2D intercalation chemistry in few‐layered nanomaterials is still under its infant stage. The new intercalation phenomena behind the interlayer engineering of few‐layered nanomaterials need to be discovered and further comprehensively exploited. It is strongly believed that with more attentions and efforts put into this spring field, the few‐layered 2D nanomaterials will make great impact on the nanoscience and nanotechnology, enabling them more profound than their microstructural counterparts and even their monolayers.
Reversible Resistance Switching of 2D Electron Gas at LaAlO3/SrTiO3 Heterointerface
Authors: Gao Zhaomeng , Huang Xiushi , Li Pei , Wang Longfei , Wei Ling , Zhang Weifeng , Guo Haizhong
Published: February 2018

Resistance modulation of 2D electron gas (2DEG) at oxide heterointerfaces has recently attracted extensive interests in nonvolatile memory and various sensors. Specially, ferroelectric devices based on 2DEG resistance switching at oxide heterointerfaces by ferroelectric polarization are particularly important in memory and light sensors. Herein, a nonvolatile ferroelectric memristor is reported by the 2DEG resistance change at an LaAlO3/SrTiO3 heterointerface by switching the ferroelectric polarization of a BiFeO3 layer, showing reversible two order of magnitude resistance change, the largest switching ratio in free‐lead ferroelectric memristors so far. The mechanisms of the 2DEG reversible resistance switching at the LaAlO3/SrTiO3 heterointerfaces modulated by the ferroelectric polarization and light illumination are discussed. These findings demonstrate a practical approach for the nonvolatile memory and sensor applications using the 2DEG resistance switching by the ferroelectric polarization and light illumination.
Cavity‐Induced Enhancement of Magneto‐Optic Effects in Monolayer Transition Metal Dichalcogenides
Authors: Da Haixia , Gao Lei , An Yipeng , Zhang Haiyan , Yan Xiaohong
Published: February 2018

Monolayer transition metal dichalcogenides represent a class of 2D direct‐bandgap semiconductors, which do not support magneto‐optical (MO) effects in the absence of magnetic field due to time reversal symmetry. Magnetic exchange field (MEF) has been demonstrated to be able to generate MO effects in monolayer transition metal dichalcogenides, causing Faraday rotation of several tenths of degree without the need of magnetic field. Here, the possibility of enhancing the MO effects of monolayer transition metal dichalcogenides upon MEF using a cavity structure is investigated. It is identified that the Faraday rotation (FR) angle can be boosted by choosing the proper thickness of optical cavity due to its resonant characteristics. In particular, unlike the conventional bulky magnetic materials always with fixed MO effects, the FR angle here can be manipulated by the chemical potential, enabling a route of engineering the MO effects in monolayer transition metal dichalcogenides. The results suggest 2D layered semiconductors being the possible building blocks in nonreciprocal MO devices.
High‐Throughput Multiparametric Screening of Solution Processed Bulk Heterojunction Solar Cells
Authors: Sánchez‐Díaz Antonio , Rodríguez‐Martínez Xabier , Córcoles‐Guija Laura , Mora‐Martín Germán , Campoy‐Quiles Mariano
Published: February 2018

One of the major bottlenecks in the development of organic photovoltaics is the time needed to evaluate each material system. This time ranges from weeks to months if different variables such as blend composition, thickness, annealing, and additives are to be explored. In this study, the use of lateral gradients is proposed in order to evaluate the photovoltaic potential of a material system up to 50 times faster. A platform that combines blade coating using controllable velocity profiles (thickness gradients) with multichannel dispensers (composition gradients) and controlled lateral annealing variations (nanostructure gradients) is introduced. These samples are then analyzed using photocurrent and Raman imaging in order to correlate one to one the device performance, thickness, composition, and annealing temperature. The strength of the developed technology is shown by optimizing three different systems, namely PCDTBT:PC70BM, PTB7‐Th:PC70BM, and PffBT4T‐2OD:PC70BM, obtaining efficiencies ≈5%, 8%, and 9.5%, respectively, using less than 10 mg of each polymer in the process.
Dendrite‐Free and Performance‐Enhanced Lithium Metal Batteries through Optimizing Solvent Compositions and Adding Combinational Additives
Authors: Li Xing , Zheng Jianming , Ren Xiaodi , Engelhard Mark H. , Zhao Wengao , Li Qiuyan , Zhang Ji‐Guang , Xu Wu
Published: February 2018

The instability of lithium (Li) metal anodes due to dendritic growth and low Coulombic efficiency (CE) hinders the practical application of high‐energy‐density Li metal batteries. Here, the systematic studies of improving the stability of Li metal anodes and the electrochemical performance of Li metal batteries through the addition of combinational additives and the optimization of solvent compositions in dual‐salt/carbonate electrolytes are reported. A dendrite‐free and high CE of 98.1% for Li metal anode is achieved. The well‐protected Li metal anode and the excellent cyclability and rate capability of the 4‐V Li metal batteries are obtained. This is attributed to the formation of a robust, denser, more polymeric, and higher ionic conductive surface film on the Li metal anode via the electrochemical reductive decompositions of the electrolyte components and the ring‐opening polymerization of additives and cyclic carbonate solvents. The key findings of this work indicate that the optimization of solvent compositions and the manipulation of additives are facile and effective ways to enhance the performances of Li metal batteries.
Another Strategy, Detouring Potential Decay by Fast Completion of Cation Mixing
Authors: Liu Shuai , Feng Xin , Wang Xuelong , Shen Xi , Hu Enyuan , Xiao Ruijuan , Yu Richeng , Yang Haitao , Song Ningning , Wang Zhaoxiang , Yang Xiaoqing , Chen Liquan
Published: February 2018

The Li‐rich layer‐structured oxides are regarded one of the most promising candidates of cathode materials for high energy‐density Li‐ion batteries. However, the uninterrupted migration of the transition metal (TM) ions during cycling and the resultant continuous fading of their discharge potentials bring challenges to the battery design and impede their commercial applications. Various efforts have been taken to suppress the migration of the TM ions such as surface modification and elemental substitution, but no success has been achieved to date. Another strategy hereby is proposed to address these issues, in which the TM migration is promoted and the layered material is transformed to a rocksalt in the first few charge/discharge cycles by specially designing a novel Li‐rich layer‐structured Li1.2Mo0.6Fe0.2O2 on the basis of density functional theory calculations. With such, the continuous falling of the discharge potential is detoured due to enhanced completion of the cation mixing. In‐depth studies such as aberration‐corrected scanning transmission electron microscopy confirm the drastic structural change at the atomic scale, and in situ X‐ray absorption spectroscopy and Mössbauer spectroscopy clarify its charge compensation mechanism. This new strategy provides revelation for the development of the Li‐rich layered oxides with mitigated potential decay and a longer lifespan.
Highly Efficient Tandem Organic Solar Cell Enabled by Environmentally Friendly Solvent Processed Polymeric Interconnecting Layer
Authors: Zhang Kai , Fan Baobing , Xia Ruoxi , Liu Xiang , Hu Zhicheng , Gu Honggang , Liu Shiyuan , Yip Hin‐Lap , Ying Lei , Huang Fei , Cao Yong
Published: February 2018

In the field of organic solar cells (OSCs), tandem structure devices exhibit very attractive advantages for improving power conversion efficiency (PCE). In addition to the well researched novel pair of active layers in different subcells, the construction of interconnecting layer (ICL) also plays a critical role in achieving high performance tandem devices. In this work, a new way of achieving environmentally friendly solvent processed polymeric ICL by adopting poly[(9,9‐bis(3′‐(N,N‐dimethylamino)propyl)‐2,7‐fluorene)‐alt‐5,5′‐bis(2,2′‐thiophene)‐2,6‐naphthalene‐1,4,5,8‐tetracaboxylic‐N,N′‐di(2‐ethylhexyl)imide] (PNDIT‐F3N) blended with poly(ethyleneimine) (PEI) as the electron transport layer (ETL) and PEDOT:PSS as the hole transport layer is reported. It is found that the modification ability of PNDIT‐F3N on PEDOT can be linearly tuned by the incorporation of PEI, which offers the opportunity to study the charge recombination behavior in ICL. At last, tandem OSC with highest PCE of 12.6% is achieved, which is one of the best tandem OSCs reported till now. These results offer a new selection for constructing efficient ICL in high performance tandem OSCs and guide the way of design new ETL materials for ICL construction, and may even be integrated in future printed flexible large area module device fabrication with the advantages of environmentally friendly solvent processing and thickness insensitivity.
Phylogenetic and environmental effects on limb bone structure in gorillas
Authors: Ruff Christopher B. , Burgess M. Loring , Junno Juho‐Antti , Mudakikwa Antoine , Zollikofer Christophe P. E. , Ponce de León Marcia S. , McFarlin Shannon C.
Published: February 2018

Objectives

The effects of phylogeny and locomotor behavior on long bone structural proportions are assessed through comparisons between adult and ontogenetic samples of extant gorillas.

Materials and Methods

A total of 281 wild‐collected individuals were included in the study, divided into four groups that vary taxonomically and ecologically: western lowland gorillas (G. g. gorilla), lowland and highland grauer gorillas (G. b. graueri), and Virunga mountain gorillas (G. b. beringei). Lengths and articular breadths of the major long bones (except the fibula) were measured, and diaphyseal cross‐sectional geometric properties determined using computed tomography. Ages of immature specimens (n = 145) were known or estimated from dental development. Differences between groups in hind limb to forelimb proportions were assessed in both adults and during development.

Results

Diaphyseal strength proportions among adults vary in parallel with behavioral/ecological differences, and not phylogeny. The more arboreal western lowland and lowland grauer gorillas have relatively stronger forelimbs than the more terrestrial Virunga mountain gorillas, while the behaviorally intermediate highland grauer gorillas have intermediate proportions. Diaphyseal strength proportions are similar in young infants but diverge after 2 years of age in western lowland and mountain gorillas, at the same time that changes in locomotor behavior occur. There are no differences between groups in length or articular proportions among either adults or immature individuals.

Conclusion

Long bone diaphyseal strength proportions in gorillas are developmentally plastic, reflecting behavior, while length and articular proportions are much more genetically canalized. These findings have implications for interpreting morphological variation among fossil taxa.
Evaluation of disulfide chain extender effect on the mechanical properties of unsaturated polyurethane‐urea networks
Authors: Yarmohammadi Masoud , Shahidzadeh Mansour
Published: February 2018

4‐Aminophenyl disulfide and bis(4‐aminophenyl)methane chain extenders containing hydroxyl‐terminated polybutadiene‐based polyurethane‐ureas are prepared one‐shot to explore the effect of the chain extender structure on the elastomers mechanical properties. However, the results revealed that the participation of the disulfide chain extender in side reactions like thiol‐ene and proton abstraction prevented disulfide metathesis reaction due to decomposing chain extender in the polyurethane‐urea matrix. Also, these side reactions improved the phase mixing via chemical crosslinking between polyurethane‐ureas soft and hard segments, too. Tensile test results showed higher stress strength of the elastomers in the presence of the disulfide chain extender in comparison with the nondisulfide bond containing elastomers. This result was in agreement with the observed result in dynamical mechanical analysis. Dynamic mechanical analysis results established that the absence of the disulfide bond in the polyurethane‐urea matrix led to the higher viscous modulus. The swelling test revealed chemical crosslinking increased in the presence of the disulfide bond. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46309.
Effect of viscosity and surface tension on dynamic percolation in liquid media
Authors: Badard M. , Combessis A. , Allais A. , Flandin L.
Published: February 2018

Percolation of carbon nanotubes in liquid media has been studied as a function of their surface tension and intrinsic viscosity. Carbon nanotubes were dispersed in different liquids by means of ultrasound, and the suspensions were gradually further diluted to obtain a large number of well‐defined filler contents. Percolation was probed with a remarkable accuracy thanks to a specific test procedure combining dilutions and electrical testing. Percolation threshold values were found to be lower (close to 0.01 vol %) than the ones obtained in molten polymers, due to the ease of particles aggregating in liquid media. The aggregation over time of carbon nanotubes from a dispersed and distributed state into particle networks was also monitored. Best known as dynamic percolation, this resulted in a percolation threshold eventually reduced by a factor of two. We then show that decreasing the matrix viscosity increases the dynamic component of the percolation process, yielding decreased critical filler fraction and percolation time (0.002 vol %). Finally, the effect of the difference in surface tension between the filler and matrix was also quantified. Large differences favor the aggregation mechanisms and thereby reduce the percolation threshold. An analytical model is finally proposed. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46313.
Novel synergistic flame‐retardant system of Mg–Al–Co–LDHs/DPCPB for ABS resins
Authors: Mo Hongbing , Xu Liping , Zhou Tao
Published: February 2018

Acrylonitrile‐butadiene‐styrene (ABS) resins are widely used in many sectors of the industry due to excellent mechanical properties, low temperature resistance, heat resistance, and chemical resistance. However, its flammability constitutes a key limitation in their applications. Consequently, development of flame‐retarding ABS resins is imperative. Herein, we report a novel synergistic system composed of Mg–Al–Co–layered double hydroxides (LDHs) prepared via a co‐precipitation method, and [4‐(diphenoxy‐phosphorylamino)‐6‐phenyl‐[l,3,5] triazin‐2‐y1]‐phosphoramidic acid diphenyl ester (DPCPB), a novel intumescent flame retardant. The properties of the as‐prepared LDHs/DPCPB/ABS composites are evaluated using standard combustion performance tests including limiting oxygen index (LOI) and vertical burning test (UL‐94). Novel ABS resins with the composition of ABS/DPCPB = 100/25 and ABS/DPCPB/LDHs = 100/2l/4 exhibit higher LOIs, 23.9 and 24.7, respectively, compared to 18.1 for the pure ABS. Meanwhile, they meet the V‐2 and A‐1 level, respectively, in UL‐94 tests. Moreover, the prepared composites exert flame‐retarding effects in gas phase and condensed phase simultaneously. Our results reveal synergistic effects between Mg–Al–Co–LDHs and DPCPB for the flame retardation of ABS resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46319.
Stereodivergent Hydroboration of Allenes
Authors: Nagashima Yoshiyuki , Sasaki Keiji , Suto Takahiro , Sato Takaaki , Chida Noritaka
Published: February 2018

Full details of a stereodivergent hydroboration of allenes are reported. While hydroboration of an allene with 9‐BBN provided a thermodynamically stable (E)‐allylic alcohol after oxidative work‐up, the reaction of an identical allene with HB(Sia)2 (disiamylborane) formed a (Z)‐allylic alcohol as the kinetic product. The developed conditions allowed for the synthesis of trisubstituted olefins in a highly stereoselective fashion, which is known to be challenging. The method was also applied to the stereodivergent synthesis of structural motifs such as skipped dienes and allylbenzenes, which are often embedded in biologically active natural products.
Robust, domain‐specific effects of prior context in risk preferences for pension choice
Authors: Bird Sarah , Harris Adam J.L.
Published: February 2018

Evidence that context changes measured risk preferences raises concerns about the practice of measuring financial risk attitude in one context to guide investment choice. We found that participants who first made choices between pairs of high (low) risk pension funds subsequently preferred higher (lower) risk funds when offered a choice from a wider range of funds. This effect was also observed when the riskiness of the initial pension funds was manipulated within subjects. Effects were not influenced by order, or attenuated by a bias warning. Tests across the domains of recreational and financial risk found that context effects are domain specific and that they influence both choices and judgments. Our results are consistent with theories of relative judgement. However, we also observed some evidence of sensitivity to absolute values. From an applied perspective, understanding such contextual sensitivity is important for recognising the limitations of risk profiling tools as part of a regulated financial advice process.
Supramolecular separation mechanism of pentafluorophenyl column using ibuprofen and omeprazole as markers: LC‐MS and simulation study
Authors: Hussain Afzal , AlAjmi Mohamed F. , Ali Imran
Published: February 2018

The pentafluorophenyl (PFP) column is emerging as a new advancement in separation science to analyze a wide range of analytes and, thus, its separation mechanism at supramolecular level is significant. We developed a mechanism for the separation of ibuprofen and omeprazole using different combinations (ranging from 50:50 to 60:40) of water–acetonitrile containing 0.1% formic acid as the mobile phase. The column used was Waters Acquity UPLC HSS PFP (75 × 2.1 mm, 1.8 μm). The reverse order of elution was observed in different combinations of the mobile phases. The docking study indicated hydrogen bonding between ibuprofen and PFP stationary phase (binding energy was −11.30 kJ/mol). Separation at PFP stationary phase is controlled by hydrogen bonding along with π–π interactions. This stationary phase may be used to analyze both aromatic and aliphatic analytes. The developed mechanism will be useful to separate various analytes by considering the possible interactions, leading to saving of energy, time and money. In addition, this work will be highly useful in preparative chromatography where separation is the major problem at a large scale. Moreover, the developed LC‐MS‐QTOF method may be used to analyze ibuprofen and omeprazole in an unknown sample owing to the low value of detection limits.
Metabolomic analysis for the protective effects of mangiferin on sepsis‐induced lung injury in mice
Authors: Wang Yilin , Liu Yang , Cao Qiqi , Shi Xuan , Lu Hongtao , Gao Songyan , Yang Rui
Published: February 2018

This study aimed to investigate the efficacy of mangiferin, including its known antioxidant and anti‐inflammatory effects on sepsis‐induced lung injury induced by a classical cecal ligation and puncture (CLP) models in mouse using a metabolomics approach. A total of 24 mice were randomly divided into four groups: the sham group was given saline before sham operation. The CLP group received the CLP operation only. HMF and LMF groups were given mangiferin treatment of high dose and low dose of mangiferin, respectively, before the CLP operation. One week after treatment, the mice were sacrificed and their lungs were collected for metabolomics analysis. We developed ultra‐performance liquid chromatography coupled with quadrupole‐time‐of‐flight mass spectrometry to perform lung metabolic profiling analysis. With the methods of principal component analysis and partial least squares discriminant analysis, 58 potential metabolites associated with amino acid metabolism, purine metabolism, lipid metabolism and energy regulation were observed to be increased or reduced in HMF and LMF groups compared with the CLP group. Conclusively, our results suggest that mangiferin plays a protective role in the moderation of sepsis‐induced lung injury through reducing oxidative stress, regulating lipid metabolism and energy biosynthesis.
Alanine and Lysine Scans of the LL‐37‐Derived Peptide Fragment KR‐12 Reveal Key Residues for Antimicrobial Activity
Authors: Gunasekera Sunithi , Muhammad Taj , Strömstedt Adam A. , Rosengren K. Johan , Göransson Ulf
Published: February 2018

The human host defence peptide LL‐37 is a broad‐spectrum antibiotic with immunomodulatory functions. Residues 18–29 in LL‐37 have previously been identified as a minimal peptide (KR‐12) that retains antibacterial activity with decreased cytotoxicity. In this study, analogues of KR‐12 were generated by Ala and Lys scans to identify key elements for activity. These were tested against a panel of human pathogens and for membrane permeabilisation on liposomes. Replacements of hydrophobic and cationic residues with Ala were detrimental for antibiotic potency. Substitutions by Lys increased activity, as long as the increase in cationic density did not disrupt the amphiphilic disposition of the helical structure. Importantly, substitutions showed differential effects against different organisms. Replacement of Gln5 with Lys and Asp9 with Ala or Lys improved the broad‐spectrum activity most, each resulting in up to an eightfold increase in potency against Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. The improved analogues displayed no significant toxicity against human cells, and thus, KR‐12 is a tuneable template for antibiotic development.
Identification and management of high‐risk psychosis in children and adolescents
Authors: Reyna Lorena E. , Hunt Jeffrey
Published: February 2018

Case: Carl is a 9‐year‐old male who presented to an outpatient clinic because he was demonstrating increasing social isolation and preoccupation with cockroaches. His teachers are also concerned about his unusually graphic drawings depicting violent themes. He is often described as “flat” and not easily engaged. He is reported to have an “odd” pattern of speaking. He has no close friends and is struggling academically. His mother and maternal uncle have a diagnosis of schizophrenia. His father has a history of being incarcerated for assault. He lives with maternal grandparents.
Most middle/high school students don't get enough sleep: CDC
Authors: Knopf Alison
Published: February 2018

More than half of middle school students and almost three‐quarters of high school students do not get enough sleep on school nights, according to the first national study that looked at the problem on a state‐by‐state basis. According to researchers at the federal Centers for Disease Control and Prevention (CDC), prevalence rates of insufficient sleep are going up, not down.
Efficient Solvent‐Free Carbon Dioxide Fixation Reactions with Epoxides Under Mild Conditions by Mixed‐Ligand Zinc(II) Metal–Organic Frameworks
Authors: Patel Parth , Parmar Bhavesh , Kureshy Rukhsana I. , Khan Noor‐ul , Suresh Eringathodi
Published: February 2018

Mixed‐ligand 3 D/2 D Zn metal–organic frameworks (MOFs) {[Zn(bdc)(L1)]⋅x G}n (ZnMOF‐1) and {[Zn(ipa)(L2)]}n (ZnMOF‐2; in which H2BDC=benzene‐1,4‐dicarboxylic acid, L1=4‐pyridyl carboxaldehyde isonicotinoylhydrazone, H2IPA=isophthalic acid, L2=3‐pyridyl carboxaldehyde nicotinoyl hydrazone, and G=lattice guests) were synthesized using versatile synthetic routes that include a green mechanochemical (grinding) reaction. Chemical and thermal stability, phase purity, and characterization of the ZnMOFs synthesized by different approaches were established by using various analytical methods. Both ZnMOFs can be used as a highly active, solvent‐free, binary catalyst for CO2 cycloaddition with epoxides under ambient reaction conditions of 1 atm pressure and room temperature/40 °C, in the presence of the cocatalyst nBu4NBr. The yield, recyclability, and stability of ZnMOF‐1 as a potential catalyst towards epoxide to cyclic carbonate conversion are excellent under ambient conditions. From literature and experimental inferences, a rationalized mechanism mediated by the Zn center of ZnMOFs for the CO2‐epoxide cycloaddition reaction has been proposed. To the best of our knowledge, very few MOF‐based catalysts have been reported to realize the conversion of CO2 to useful products under similar mild conditions. In the present investigation, that is, catalyst preparation by green mechanochemical synthesis and catalysis under ambient, solvent‐free conditions were performed with minimum energy utilization.
Synthesis of Terminal Vinylindoles via RhIII‐Catalyzed Direct C−H Alkenylation with Potassium Vinyltrifluoroborate
Authors: Zhou Chun‐Ni , Xie Hao‐Hao , Zheng Zi‐Ang , Xiao Yuan‐Chao , Li Gen , Shen Yang‐Huan , Peng Wang‐Ming , Wang Liang
Published: February 2018

An efficient RhIII‐catalyzed direct C2‐alkenylation of indoles using readily available potassium vinyltrifluoroborate under mild conditions has been developed. This protocol features wide substrate scope and excellent functional group compatibility, enabling a facile access to diverse terminal vinylindoles in moderate to good yields. Furthermore, the C2‐alkenylated indole can be easily transformed into 9H‐carbazole through a ring‐closing metathesis/aromatization cascade.
Polymer Electron Acceptors Based on Fluorinated Isoindigo Unit for Polymer Solar Cells
Authors: Miao Junhui , Xu Han , Meng Bin , Liu Jun , Wang Lixiang
Published: February 2018

Most of efficient polymer electron acceptors for polymer solar cells (PSCs) are based on naphthalene diimide or perylene diimide as the electron deficient building block. In this paper, for the first time, we report polymer electron acceptors based on fluorinated isoindigo (F‐IID) as the electron deficient building block. We synthesized two polymer electron acceptors consisting of alternating F‐IID unit and thiophene/selenophen unit. They show low‐lying LUMO/HOMO energy levels of –3.69/–5.69 eV, high electron mobilities of 1.31×10–5 cm2·V–1·s–1 and broad absorption spectra with the optical bandgap of 1.61 eV. PSC devices using the two F‐IID‐based polymers as polymer electron acceptors show encouraging power conversion efficiencies (PCEs) of up to 1.50% with an open‐circuit voltage (VOC) of 0.97 V, a short‐circuit current density (JSC) of 2.91 mA·cm–2, and a fill factor (FF) of 53.2%. This work suggests a new kind of polymer electron acceptors based on F‐IID unit.
Fabrication of Mesoporous Titania Nanoparticles with Controlled Porosity and Connectivity for Studying the Photovoltaic Properties in Perovskite Solar Cells
Authors: Tanaka Yuki , Lim Siew Lay , Goh Wei Peng , Jiang Changyun , Tee Si Yin , Ye Tao , Li Xianqiang , Nguyen Khoa Ha , Lee Coryl Jing Jun , Ding Ning , Liu Zhaolin , Wu Jishan , Zhang Jie , Han Ming‐Yong
Published: February 2018

Mesoporous titania (TiO2) nanoparticles (NPs) were synthesized by treating prehydrolyzed titanium precursors with polyethylene glycol (PEG). By varying the amount of PEG, their different physical properties were tuned appropriately in terms of surface area, pore size/volume, and electrical conductivity. By increasing the amount of PEG in TiO2, the surface area and pore volume of mesoporous TiO2 increased, and no direct correlation with the photovoltaic performance of perovskite solar cells was observed. In comparison, the pore size of mesoporous TiO2 first increased greatly before quickly decreasing, and a similar trend was also observed for electrical conductivity. These implied that the interparticle interaction became much stronger with an optimum amount of PEG added to form mesoporous TiO2 NPs. With an optimum molar ratio of PEG/Ti precursor at 0.75, greatly improved conductivity of mesoporous TiO2 NPs with interconnection as compared to that prepared in the absence of PEG, which was used as an electron transport layer, improved the power conversion efficiency of perovskite solar cells by ≈36%. Their greatly reduced photoluminescence after incorporating the perovskite also revealed a difference in the electron‐injection properties from the perovskite into mesoporous TiO2. This strategy highlights a versatile tool to tune mesoporous structures to achieve a cooperative effect for studying photovoltaic properties in perovskite solar cells.
On link width scaling for energy‐proportional direct interconnection networks
Authors: Zahn Felix , Lammel Steffen , Fröning Holger
Published: February 2018

Energy consumption is one of the most important design parameters for future large‐scale computing systems. While the end of Dennard scaling demands for increasing energy‐proportional components, interconnection networks have not received much attention regarding this topic. However, these networks are expected to contribute about 20% to the overall power consumption of these systems in the near future. Furthermore, this fraction increases if other energy‐proportional components, such as CPUs, accelerators, and memory, are not fully utilized. To avoid becoming the main contributor to power consumption and to reduce overall power consumption, it is mandatory to improve the energy‐proportionality of interconnection networks. In this work, we analyze different aspects of energy‐proportionality in interconnection networks for systems designed within current technical constraints but also for future systems that might be designed with different parameters. First, we discuss the impact of multiple design parameters and the most feasible approach for improved energy consumption, such as transition time and power state granularity. Based on this study, we introduce three different power saving policies, which try to address different requirements. While an on/off policy allows for large energy savings, it can also cause significant performance losses for adverse setups. In order to meet the demand for sustainable performance, we present two new policies that trade power saving potential for performance. For all three workload classes, we use a power‐aware network simulation to report the impact on execution time and energy consumption compared to the current situation and an idealized network. While we show that a highly regular pattern enables power saving possibilities close to the theoretical minimum, even slight deviations from such a highly iterative and temporal behavior demand for further improvements in all policies.
Liebowitz Social Anxiety Scale (LSAS): Optimal cut points for remission and response in a German sample
Authors: von Glischinski M. , Willutzki U. , Stangier U. , Hiller W. , Hoyer J. , Leibing E. , Leichsenring F. , Hirschfeld G.
Published: February 2018

The Liebowitz Social Anxiety Scale (LSAS) is the most frequently used instrument to assess social anxiety disorder (SAD) in clinical research and practice. Both a self‐reported (LSAS‐SR) and a clinician‐administered (LSAS‐CA) version are available. The aim of the present study was to define optimal cut‐off (OC) scores for remission and response to treatment for the LSAS in a German sample.

Data of N = 311 patients with SAD were used who had completed psychotherapeutic treatment within a multicentre randomized controlled trial. Diagnosis of SAD and reduction in symptom severity according to the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, served as gold standard. OCs yielding the best balance between sensitivity and specificity were determined using receiver operating characteristics. The variability of the resulting OCs was estimated by nonparametric bootstrapping.

Using diagnosis of SAD (present vs. absent) as a criterion, results for remission indicated cut‐off values of 35 for the LSAS‐SR and 30 for the LSAS‐CA, with acceptable sensitivity (LSAS‐SR: .83, LSAS‐CA: .88) and specificity (LSAS‐SR: .82, LSAS‐CA: .87). For detection of response to treatment, assessed by a 1‐point reduction in the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, 4th edition, rating, a reduction of 28% for the LSAS‐SR and 29% for the LSAS‐CA yielded the best balance between sensitivity (LSAS‐SR: .75, LSAS‐CA: .83) and specificity (LSAS‐SR: .76, LSAS‐CA: .80).

To our knowledge, we are the first to define cut points for the LSAS in a German sample. Overall, the cut points for remission and response corroborate previously reported cut points, now building on a broader data basis.
Photoconversion of Far‐Red Organic Dyes: Implications for Multicolor Super‐Resolution Imaging
Authors: Dirix Lieve , Kennes Koen , Fron Eduard , Debyser Zeger , van der Auweraer Mark , Hofkens Johan , Rocha Susana
Published: February 2018

Localization‐based super‐resolution microscopy has become an indispensable tool in biology to study features smaller than the diffraction limit of light. In a multicolor approach, adequate spectral separation of the different photoswitchable probes is required. A far‐red emitting dye is often one of the labels of choice. However, irradiation with high laser intensity can induce photo‐conversion of some of the most frequently used fluorophores. Herein we show that upon intense irradiation with a 561 nm laser line, far‐red organic dyes photoconvert to blue‐shifted emissive species. In the case of Alexa Fluor 647, the most commonly used fluorescent label in super‐resolution microscopy, this derivative is created over time in an intramolecular, irreversible photoinduced chemical reaction. The dynamics of this reaction are altered by the presence of reducing agents. Importantly, the blue‐shifted derivatives emit in the spectral range of the red fluorescent proteins (e. g. PAmCherry and converted mEos3.2), severely implicating multicolor super‐resolution imaging.
Isothermal Growth of Spinel Crystals in Vanadium‐Chromium Slag
Authors: Diao Jiang , Shao Lixiong , Zhou Wang , Zhang Tao , Xie Bing
Published: February 2018

In order to explore the isothermal growth crystallization mechanism of vanadium‐chromium slag, the growth behavior of spinel crystals in vanadium‐chromium slag is investigated in this paper by using SEM/EDS and crystal size distribution (CSD) theory. It is found that with the prolongation of holding time at 1523 K, the mean diameter of spinel crystals decrease in the initial 30 min and then increased to 60.34 µm. The area fraction of spinel crystals increases from 35.56 to 54.28%. While at 1623 K, expect for the transient decrease at 30 min, the mean diameter of spinel crystals also increases obviously with the prolongation of time. The area fraction of spinel crystals increase from 31.28 to 50%. The results reveal that low temperature befits the growth of spinel crystals. All CSD shapes of vanadium‐chromium slag are lognormal distribution, which implies that the growth of the spinel crystals is controlled by surface and supply, and more inclined to supply control.