bluuebunny/crossref_metadata_2025 huggingface dataset:
A Generic Self‐Assembly Process in Microcompartments and Synthetic Protein Nanotubes
Authors: Uddin Ismail , Frank Stefanie , Warren Martin J. , Pickersgill Richard W.
Published: March 2018

Bacterial microcompartments enclose a biochemical pathway and reactive intermediate within a protein envelope formed by the shell proteins. Herein, the orientation of the propanediol‐utilization (Pdu) microcompartment shell protein PduA in bacterial microcompartments and in synthetic nanotubes, and the orientation of PduB in synthetic nanotubes are revealed. When produced individually, PduA hexamers and PduB trimers, tessellate to form flat sheets in the crystal, or they can self‐assemble to form synthetic protein nanotubes in solution. Modelling the orientation of PduA in the 20 nm nanotube so as to preserve the shape complementarity and key interactions seen in the crystal structure suggests that the concave surface of the PduA hexamer faces out. This orientation is confirmed experimentally in synthetic nanotubes and in the bacterial microcompartment produced in vivo. The PduB nanotubes described here have a larger diameter, 63 nm, with the concave surface of the trimer again facing out. The conserved concave surface out characteristic of these nano‐structures reveals a generic assembly process that causes the interface between adjacent subunits to bend in a common direction that optimizes shape complementarity and minimizes steric clashes. This understanding underpins engineering strategies for the biotechnological application of protein nanotubes.
Transition‐Metal‐Based Electrocatalysts as Cocatalysts for Photoelectrochemical Water Splitting: A Mini Review
Authors: Li Deng , Shi Jingying , Li Can
Published: March 2018

Converting solar energy into hydrogen via photoelectrochemical (PEC) water splitting is one of the most promising approaches for a sustainable energy supply. Highly active, cost‐effective, and robust photoelectrodes are undoubtedly crucial for the PEC technology. To achieve this goal, transition‐metal‐based electrocatalysts have been widely used as cocatalysts to improve the performance of PEC cells for water splitting. Herein, this Review summarizes the recent progresses of the design, synthesis, and application of transition‐metal‐based electrocatalysts as cocatalysts for PEC water splitting. Mo, Ni, Co‐based electrocatalysts for the hydrogen evolution reaction (HER) and Co, Ni, Fe‐based electrocatalysts for the oxygen evolution reaction (OER) are emphasized as cocatalysts for efficient PEC HER and OER, respectively. Particularly, some most efficient and robust photoelectrode systems with record photocurrent density or durability for the half reactions of HER and OER are highlighted and discussed. In addition, the self‐biased PEC devices with high solar‐to‐hydrogen efficiency based on earth‐abundant materials are also addressed. Finally, this Review is concluded with a summary and remarks on some challenges and opportunities for the further development of transition‐metal‐based electrocatalysts as cocatalysts for PEC water splitting.
Ultraviolet Photoluminescence of Carbon Nanospheres and its Surface Plasmon‐Induced Enhancement
Authors: Gan Zhixing , Pan Pengfei , Chen Zhihui , Meng Ming , Xu Hao , Yu Zhizhou , Chang Chenliang , Tao Yongchun
Published: March 2018

Ultraviolet (UV) light can be used in versatile applications ranging from photoelectronic devices to biomedical imaging. In the development of new UV light sources, in this study, stable UV emission at ≈350 nm is unprecedentedly obtained from carbon nanospheres (CNSs). The origin of the UV fluorescence is comprehensively investigated via various characterization methods, including Raman and Fourier transform infrared analyses, with comparison to the visible emission of carbon nanodots. Based on the density functional calculations, the UV fluorescence is assigned to the carbon nanostructures bonded to bridging O atoms and dangling –OH groups. Moreover, a twofold enhancement in the UV emission is acquired for Au‐carbon core‐shell nanospheres (Au‐CNSs). This remarkable modification of the UV emission is primarily ascribed to charge transfer between the CNSs and the Au surface.
Printing 1D Assembly Array of Single Particle Resolution for Magnetosensing
Authors: Gao Meng , Kuang Minxuan , Li Lihong , Liu Meijin , Wang Libin , Song Yanlin
Published: March 2018

Magnetosensing is a ubiquitous ability for many organism species in nature. 1D assembly, especially that arranged in single‐particle‐resolution regulation, is able to sense the direction of magnetic field depending on the enhanced dipolar interaction in the linear orientation. Inspired by the magnetosome structure in magnetotactic bacteria, a 1D assembly array of single particle resolution with controlled length and well‐behaved configuration is prepared via inkjet printing method assisted with magnetic guiding. In the fabrication process, chains in a “tip‐to‐tip” regulation with the desired number of particles are prepared in a confined tiny inkjet‐printed droplet. By adjusting the receding angle of the substrate, the assembled 1D morphology is kept/deteriorated depending on the pinning/depinning behavior during ink evaporation, which leads to the formation of well‐behaved 1D assembly/aggregated dot assembly. Owing to the high‐aspect‐ratio characteristic of the assembled structure, the as‐prepared 1D arrays can be used for magnetic field sensing with anisotropic magnetization M///M⊥ up to 6.03.
Synthesis of Branched DNA Scaffolded Super‐Nanoclusters with Enhanced Antibacterial Performance
Authors: Yang Lu , Yao Chi , Li Feng , Dong Yuhang , Zhang Zhikun , Yang Dayong
Published: March 2018

Metal nanoclusters (NCs) possess unique optical properties, and exhibit a wide variety of potential applications. DNA with robust molecular programmability is demonstrated as an ideal scaffold to regulate the formation of NCs, offering a rational approach to precisely tune the spatial structures of NCs. Herein, the first use of branched DNA as scaffold to regulate the formation of silver nanoclusters (super‐AgNC) is reported, in which the spatial structures are precisely designed and constructed. Super‐AgNC with tunable shapes and arm‐lengths including Y‐, X‐, and (Y–X)‐ shaped super‐AgNC is achieved. The molecular structures and optical properties of super‐AgNCs are systemically studied. As a proof of application, remarkably, super‐AgNCs exhibit superior antibacterial performance. In addition, super‐AgNCs show excellent biocompatibility with three types of tissue cells including 293T (human embryonic kidney cells), SMCs (vascular smooth muscle cells), and GLC‐82 (lung adenocarcinoma cells). These performances enable the super‐AgNCs adaptable in a variety of applications such as biosensing, bioimaging, and antibacterial agents.
Interactions of Fullerene‐Polyglycerol Sulfates at Viral and Cellular Interfaces
Authors: Donskyi Ievgen , Drüke Moritz , Silberreis Kim , Lauster Daniel , Ludwig Kai , Kühne Christian , Unger Wolfgang , Böttcher Christoph , Herrmann Andreas , Dernedde Jens , Adeli Mohsen , Haag Rainer
Published: March 2018

Understanding the mechanism of interactions of nanomaterials at biointerfaces is a crucial issue to develop new antimicrobial vectors. In this work, a series of water‐soluble fullerene‐polyglycerol sulfates (FPS) with different fullerene/polymer weight ratios and varying numbers of polyglycerol sulfate branches are synthesized, characterized, and their interactions with two distinct surfaces displaying proteins involved in target cell recognition are investigated. The combination of polyanionic branches with a solvent exposed variable hydrophobic core in FPS proves to be superior to analogs possessing only one of these features in preventing interaction of vesicular stomatitis virus coat glycoprotein (VSV‐G) with baby hamster kidney cells serving as a model of host cell. Interference with L‐selectin‐ligand binding is dominated by the negative charge, which is studied by two assays: a competitive surface plasmon resonance (SPR)‐based inhibition assay and the leukocyte cell (NALM‐6) rolling on ligands under flow conditions. Due to possible intrinsic hydrophobic and electrostatic effects of synthesized compounds, pico‐ to nanomolar half maximal inhibitory concentrations (IC50) are achieved. With their highly antiviral and anti‐inflammatory properties, together with good biocompatibility, FPS are promising candidates for the future development towards biomedical applications.
Tunable Confinement for Bridging Single‐Cell Manipulation and Single‐Molecule DNA Linearization
Authors: Yu Miao , Hou Youmin , Song Ruyuan , Xu Xiaonan , Yao Shuhuai
Published: March 2018

DNA linearization by nanoconfinement has offered a new avenue toward large‐scale genome mapping. The ability to smoothly interface the widely different length scales from cell manipulation to DNA linearization is critical to the development of single‐cell genomic mapping or sequencing technologies. Conventional nanochannel technologies for DNA analysis suffer from complex fabrication procedures, DNA stacking at the nanochannel entrance, and inefficient solution exchange. In this work, a dynamic and tunable confinement strategy is developed to manipulate and linearize genomic‐length DNA molecules from a single cell. By leveraging pneumatic microvalve control and elastomeric collapse, an array of nanochannels with confining dimension down to 20 nm and length up to sub‐millimeter is created and can be dynamically tuned in size. The curved edges of the microvalve form gradual transitions from microscale to nanoscale confinement, smoothly facilitating DNA entry into the nanochannels. A unified micro/nanofluidic device that integrates single‐cell trapping and lysis, DNA extraction, purification, labeling, and linearization is developed based on dynamically controllable nanochannels. Mbp‐long DNA molecules are extracted directly from a single cell and in situ linearized in the nanochannels. The device provides a facile and promising platform to achieve the ultimate goal of single‐cell, single‐genome analysis.
Direct‐Patterning SWCNTs Using Dip Pen Nanolithography for SWCNT/Silicon Solar Cells
Authors: Corletto Alexander , Yu LePing , Shearer Cameron J. , Gibson Christopher T. , Shapter Joseph G.
Published: March 2018

Dip pen nanolithography (DPN) is used to pattern single‐walled carbon nanotube (SWCNT) lines between the n‐type Si and SWCNT film in SWCNT/Si solar cells. The SWCNT ink composition, loading, and DPN pretreatment are optimized to improve patterning. This improved DPN technique is then used to successfully pattern >1 mm long SWCNT lines consistently. This is a 20‐fold increase in the previously reported direct‐patterning of SWCNT lines using the DPN technique, and demonstrates the scalability of the technique to pattern larger areas. The degree of the uniformity of SWCNTs in these lines is further characterized by Raman spectroscopy and scanning electron microscopy. The patterned SWCNT lines are used as thin conductive pathways in SWCNT/Si solar cells, similar to front contact electrodes. The critical parameters of these solar cells are measured and compared to control cells without SWCNT lines. The addition of SWCNT lines increases power conversion efficiency by 40% (relative). Importantly, the SWCNT lines reduce average series resistance by 44%, and consequently increase average fill factor by 24%.
A Building Brick Principle to Create Transparent Composite Films with Multicolor Emission and Self‐Healing Function
Authors: Xiong Yuan , Zhu Minshen , Wang Zhenguang , Schneider Julian , Huang He , Kershaw Stephen V. , Zhi Chunyi , Rogach Andrey L.
Published: March 2018

A cellulose paper is used impregnated with light‐emitting CdTe nanocrystals and carbon dots, and filled with a polyurethane to fabricate uniform transparent composite films with bright photoluminescence of red (R), green (G), and blue (B) (RGB) colors. A building brick‐like assembly method is introduced to realize RGB multicolor emission patterns from this composite material. By sectioning out individual pixels from monochrome‐emissive composite sheets, the advantage of the self‐healing properties of polyurethane is taken to arrange and weld them into a RGB patterned fabric by brief exposure to ethanol. This provides an approach to form single layer RGB light‐emitting pixels, such as potentially required in the display applications, without the use of any lithographic or etching processing. The method can utilize a wide range of different solution‐based kinds of light‐emitting materials.
Engineering 3D Ru/Graphene Aerogel Using Metal–Organic Frameworks: Capture and Highly Efficient Catalytic CO Oxidation at Room Temperature
Authors: Qu Jiafu , Chen Dongyun , Li Najun , Xu Qingfeng , Li Hua , He Jinghui , Lu Jianmei
Published: March 2018

Noble metals (Au, Pt, and Ru) loaded into carbon supports show excellent performance for CO oxidation. Herein, a tunable metal–organic framework (MOF) coating is applied to a macroscopic 3D Ru/graphene aerogel (Ru/GA) composite, using a facial step‐by‐step method. The open macroporous structure of the Ru/GA provides pathways for the access and diffusion of reactant and product molecules. The resulting HK (HKUST‐1)‐containing MOF composite exhibits good performance for CO adsorption. It can simultaneously adsorb and oxidize CO, which improves the reaction rate. In this work, the catalytic efficiency of the resulting catalyst is higher than that (≈48.4%) of the Ru/GA. These findings provide a simple method for increasing the instantaneous concentration of reactants around the catalyst, which in turn increases the reaction rate. The catalytic performances of composites subjected to different pretreatment conditions are also investigated. Hopefully, this finding may provide a feasible direction for the effective management of the diverse environment issues.
A Highly Planar Nonfullerene Acceptor with Multiple Noncovalent Conformational Locks for Efficient Organic Solar Cells
Authors: Yang Lei , Gu Wenxing , Yang Yufei , Hong Ling , Zhang Xutao , Xiao Yu , Wu Xiaoxi , Peng Aidong , Huang Hui
Published: March 2018

A novel nonfullerene small‐molecular acceptor indacenodithiophene (IDT)‐4CN is designed and synthesized with IDT as the core and benzothiadiazole and dicyanoethxylrhodanine as end‐capping groups. Multiple noncovalent conformational locks N…S, CH…O, and CH…N are introduced into the backbone, resulting in a highly planar molecular acceptor. As a result, the IDT‐4CN‐based organic solar cells exhibit a power conversion efficiency of 8.13%, which is much higher than that of PC71BM‐based devices (6.19%). A novel method is thus demonstrated to construct highly planar molecular acceptors for organic solar cells.
Tuning the Electronic Spin State of Catalysts by Strain Control for Highly Efficient Water Electrolysis
Authors: Hsu Shao‐Hui , Hung Sung‐Fu , Wang Hsin‐Yi , Xiao Fang‐Xing , Zhang Liping , Yang Hongbin , Chen Hao Ming , Lee Jong‐Min , Liu Bin
Published: March 2018

The electronic configuration is crucial in governing the binding strength of intermediates with catalysts, yet it is still challenging to control the catalysts' surface electronic spin state. Here, it is demonstrated that through surface metal–organic framework transformation followed by acid etching, the electronic spin state of surface Co3+ ions on spinel Co3O4 can be transformed from t2g6 to the high electronic spin state of t2g4eg2 by expanding the surface lattice constant, which significantly enhances the overlap of the eg orbital of cobalt with the oxygen adsorbates, and greatly improves the intermediates adsorption and thus the oxygen evolution reaction activity. The high electronic spin rich Co3O4 electrode exhibits an anodic current density of 10 mA cm−2 at an overpotential of 280 mV. The finding offers a rational design strategy to manipulate the electronic spin state of catalyst and the hybridization of molecular orbitals in water electrolysis.
Endotaxial Growth of [100]‐Oriented TaON Films on LiTaO3 Single Crystals for Enhanced Photoelectrochemical Water Splitting
Authors: Li Huiliang , Zhang Bo , Wang Zeyan , Wang Peng , Liu Yuanyuan , Zhang Xiaoyang , Qin Xiaoyan , Dai Ying , Whangbo Myung‐Hwan , Huang Baibiao
Published: March 2018

To enhance the photoelectrochemical (PEC) water splitting performance of TaON photoanodes, we grow [100]‐oriented TaON films by nitridating the (012) surface of single crystal LiTaO3 under NH3/CCl4 mixed gas. The endotaxial growth of [100]‐oriented TaON from the (012) surface of LiTaO3 produces TaON nanoporous films that can be completely exfoliated from the LiTaO3 substrate. The exfoliated film consists of interconnected worm‐like TaON nanoparticles aligned along the [100] direction perpendicular to the film surface across the film thickness. This oriented TaON porous nanostructure facilitates the transfer of photogenerated electrons across the film, hence enhancing the separation of photogenerated electron–hole pairs on the film surface. As a result, the TaON photoanode fabricated by the annealed oriented TaON films exhibits excellent PEC performances with a photocurrent of 5.32 mA cm−2 at 1.23 V versus RHE under AM 1.5 G simulated solar irradiation. This value is one of the highest photocurrents among the TaON photoanodes reported so far. Our work provides a new method to fabricate highly oriented crystalline films through an endotaxial growth process from single crystalline substrates. This method can be used to fabricate highly efficient photoelectrodes for PEC water splitting, and is expected to be useful in many other fields.
The Development and Initial Validation of the Paradigm of Systems Thinking
Authors: Randle Jason M. , Stroink Mirella L.
Published: March 2018

‘Systems thinking is a discipline for seeing wholes. It is a framework for seeing interrelationships rather than things, for seeing patterns of change rather than static “snapshots.” ’

‐Peter Senge.

The current research examined the psychological construct of systems thinking alongside other established psychological constructs of intelligence, personality, cognitive complexity and creativity to distinguish systems thinking as an independent psychological construct. Across two studies, results suggest that, while systems thinking may overlap with some of these constructs, notably intelligence and cognitive complexity, these constructs did not fully explain obtained variance in systems thinking scores and suggest that systems thinking may indeed be a distinct, perhaps foundational, psychological construct that may exist as an individual difference dimension. This exploratory study discusses the theoretical implications of systems thinking as well as further psychometric validation of the Systems Thinking Scale. © 2018 John Wiley & Sons, Ltd.
A novel and fully validated hydrophilic interaction liquid chromatography with tandem mass spectrometry method for the determination of intact carboplatin in human plasma
Authors: Ren Guanghui , Qin Zhiying , Fan Ali , Wang Yonghan , Tan Yanan , Lu Yang , Li Ning , Chen Xijng , Zhao Di
Published: March 2018

Carboplatin is an anticancer drug widely used to treat a variety of cancers. However, a simple, sensitive and rapid method for the quantitation of intact carboplatin is still absence for therapeutic drug monitoring or clinical trials. In this work, a rapid, universal, and reliable hydrophilic interaction liquid chromatography with tandem mass spectrometry method for the determination of intact carboplatin in human plasma was developed and fully validated. Carboplatin was extracted from human plasma by simple protein precipitation with acetonitrile. A good chromatographic separation of carboplatin was achieved on a Waters XBridge HILIC column (2.1 × 150 mm, 3.5 μm), with the analytical time 5.5 min for one sample. The linearity range of the assay was from 10 to 2000 ng/mL. The method was linear (r2 > 0.9989), accurate (<6% bias, 12% bias at LOQ) and precise (intra‐day and inter‐day precision of <3% coefficient of variation). The stability of intact carboplatin in human plasma with three different anticoagulants was assessed in this study. Furthermore, the matrix effect of hemolysis and hyperlipidemic samples was also evaluated for the first time. This work made the routine determination of intact carboplatin feasible and universal in clinical practice.
The Effect on Starch Pasting Properties and Predictive Glycaemic Response of Muffin Batters Using Stevianna or Inulin as a Sucrose Replacer
Authors: Gao Jingrong , Fezhong Han , Guo Xinbo , Zeng Xi‐An , Mason Susan L. , Brennan Margaret A. , Brennan Charles S.
Published: March 2018

Different levels of sugar replacers (inulin or Stevianna and Stevianna) are used in two muffin batter recipes differing in sugar:flour ratios. The properties of these sugar replacers are linked to differences in batter viscosity, starch gelatinization, and in vitro predictive glycemic response of batters. The replacement of sugar with Stevianna has no significant effect on the viscosity of the batter or the starch gelatinization. Replacement of 50% or more of the sugar with inulin increased batter viscosity. The starch gelatinization properties were altered with the incorporation of inulin. Batters incorporating Stevianna and cocoa powder has significantly different viscosity compared to the batters incorporating Stevianna without cocoa powder. In vitro starch hydrolysis of the batters illustrate that the inclusion of inulin or Stevianna significantly reduce the rate and extent of carbohydrate hydrolysis doing digestion.
Neural Stem Cell Grafts Promote Astroglia-Driven Neurorestoration in the Aged Parkinsonian Brain via Wnt/β-Catenin Signaling
Authors: L'Episcopo Francesca , Tirolo Cataldo , Peruzzotti-Jametti Luca , Serapide Maria F. , Testa Nunzio , Caniglia Salvatore , Balzarotti Beatrice , Pluchino Stefano , Marchetti Bianca
Published: March 2018

During aging—one the most potent risk factors for Parkinson's disease (PD)—both astrocytes and microglia undergo functional changes that ultimately hamper homoeostasis, defense, and repair of substantia nigra pars compacta (SNpc) midbrain dopaminergic (mDA) neurons. We tested the possibility of rejuvenating the host microenvironment and boosting SNpc DA neuronal plasticity via the unilateral transplantation of syngeneic neural stem/progenitor cells (NSCs) in the SNpc of aged mice with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-induced experimental PD. Transplanted NSCs within the aged SNpc engrafted and migrated in large proportions to the tegmental aqueduct mDA niche, with 30% acquiring an astroglial phenotype. Both graft-derived exogenous (ex-Astro) and endogenous astrocytes (en-Astro) expressed Wnt1. Both ex-Astro and en-Astro were key triggers of Wnt/β-catenin signaling in SNpc-mDA neurons and microglia, which was associated with mDA neurorescue and immunomodulation. At the aqueduct–ventral tegmental area level, NSC grafts recapitulated a genetic Wnt1-dependent mDA developmental program, inciting the acquisition of a mature Nurr1+TH+ neuronal phenotype. Wnt/β-catenin signaling antagonism abolished mDA neurorestoration and immune modulatory effects of NSC grafts. Our work implicates an unprecedented therapeutic potential for somatic NSC grafts in the restoration of mDA neuronal function in the aged Parkinsonian brain.
Durability of lightweight concrete made concurrently with waste aggregates and expanded clay
Authors: Muñoz‐Ruiperez Carmelo , Rodríguez Ángel , Junco Carlos , Fiol Francisco , Calderon Verónica
Published: March 2018

The use of waste aggregates simultaneously with expanded clay to obtain lightweight masonry mortars in construction constitutes a good way for a more sustainable society. This research presents a study about the physical properties of the mortars fabricated with construction and demolition wastes and expanded clay as lightweight material by way of flexural and compressive strength, porosity and surface abrasion resistance. Computerized tomography and microporosity show a good distribution of materials and pores. The paper also contains an analysis of the influence in the durability after incorporating different proportions of recycled aggregates. The results indicate that the properties do not suffer significant changes in external appearance after accelerated aging tests as thermal shock, saline solution, freeze and thaw, resistance to SO2 and carbonation. No flaking, cracking, splitting or cracks in the specimen's outer surfaces being observed. Therefore, it can be confirmed that the masonry mortars tested performed well in all cases when exposed to external climatic atmospheres according to the international standards.
What Role Has Hybridization Played in the Replacement of Native Roanoke Bass with Invasive Rock Bass?
Authors: Eschenroeder Jackman C. , Roberts James H.
Published: March 2018

North American sunfishes (Centrarchidae) are frequently introduced beyond their native ranges, where they may negatively impact and eventually replace native taxa through a combination of competition and hybridization. Congeneric centrarchids often lack reproductive isolating barriers and appear particularly susceptible to hybridization, though the roles of hybridization and introgression in species replacement are poorly understood. We studied hybridization among native Roanoke Bass Ambloplites cavifrons and introduced Rock Bass A. rupestris in Atlantic Slope river basins of Virginia. We sampled Ambloplites spp. from sites of known and potential species sympatry and reference sites where species were allopatric. Based on variation at microsatellite nuclear DNA (nDNA) markers and the cytochrome‐b mitochondrial DNA (mtDNA) gene, individuals were classified as A. cavifrons, A. rupestris, or hybrid, and populations were examined for genetic introgression. We detected A. rupestris and/or hybrids in seven of nine historical A. cavifrons populations, indicating multiple introduction events and a significant decline in the range of A. cavifrons. Although inferred hybrids were uncommon (15 of 417 sampled individuals), the majority had F2 or backcross origins, indicating that F1 hybrids are fertile and bidirectional introgression is possible. However, individuals with mtDNA from one species but with nDNA that is all or predominantly from the other were extremely rare, suggesting that cytonuclear incompatibilities reduced hybrid fitness. Moreover, introgression did not seem to persist over time, even in locations long occupied by both species. As such, we posit that these species readily hybridize in sympatry, but advanced hybrids have reduced fitness, inhibiting significant introgression or the development of hybrid swarms. Thus, we hypothesize that A. rupestris has replaced A. cavifrons primarily through high propagule pressure and competitive displacement, rather than by introgressive hybridization. Regardless the mechanism, prevention of further invasion of A. rupestris is key to the long‐term persistence of A. cavifrons.
Shaking table test and numerical simulation on vibration control effects of TMD with different mass ratios on a super high‐rise structure
Authors: Lu Zheng , Zhang Hengrui , Zhao Bin , Li Xianjie
Published: March 2018

In this paper, the influence of mass ratio on the vibration control effects of tuned mass damper (TMD) on a super high‐rise building has been investigated. A 1/45 scaled model of a super high‐rise building was constructed, and the TMD with the mass ratio of 0.01, 0.02, and 0.03, respectively, was suspended on the top. Shaking table test and the corresponding numerical simulation were carried out to make a further understanding of the damping mechanism. The structural performance with or without TMD was comparatively studied. The results show that larger mass ratio can improve the control effects under frequent earthquake, but the control effects increase little with the increase of mass ratio under rare earthquake due to structural damages, accompanied by stiffness degradation and nonlinear behavior of the main structure. In addition, some suggestions on the mass ratio selection are also proposed to generalize its applications.
Load‐sharing ratio of prebored and precast pile in top‐down method construction process
Authors: Kim Dohyun , Jeong Sangseom , Jung Gyungja , Park Jongjeon
Published: March 2018

The load‐sharing ratio of the prebored and precast pile in top‐down method foundation was investigated by using a numerical analysis and field case study. The emphasis was on quantifying the apparent load‐sharing ratio of the prebored and precast pile during the top‐down method construction process. A series of three‐dimensional finite element analysis were conducted, with special attention given to the pile load‐sharing ratio under various conditions, such as soil condition, pile geometry, pile length, and structure load. In addition, the load‐sharing ratio of a single pile was also investigated based on the location of the pile in the raft (footing). The analysis model was validated by comparing the analysis model with the field data of an actual construction site using the prebored and precast pile and the top‐down method. On the basis of the series of analysis results and the field measurements, when the soil condition is better than weathered rock and for moderate pile length, at least 15% of the total structure load was supported by the pile throughout the construction process. Furthermore, it was shown that the pile near the center of the raft carried more structure load compared with the piles in the side and the corner of the raft.
Optimal probability‐based partial mass isolation of elevated coal scuttle in thermal power plant building
Authors: Dai Kaoshan , Li Bowei , Wang Jianze , Li Ang , Li Huiying , Li Jiahong , Tesfamariam Solomon
Published: March 2018

Partial mass isolation (PMI) system is a practical strategy to mitigate seismic response of the main structure. Many studies provide various formulas to estimate an optimum design solution for the structure under simplified excitation models. But the efficiency of these optimization methods under actual ground motion records requires investigation. This paper proposes a new optimization design framework, which considers the randomness of ground motions. To describe the vibration depression effects of the PMI under various records, several theoretical distributions were assumed and tested. A Weibull distribution was selected because of its best performance in the chi‐squared tests among the several theoretical distributions. A sensitivity study on the number of records was performed to ensure the accuracy of estimated parameters with a relatively small sample size. This framework was adopted in the design of a PMI system for a large‐scale thermal power plant building through both single‐objective and multiobjective optimization procedures. Optimal design results from the single‐objective optimization procedure were compared with those from traditional formulas. Additionally, with the relative displacement limitation, the Pareto optimum set was obtained from the multiobjective optimization procedure. The final design was compared with the single‐objective optimization result.
Prediction of typhoon design wind speed with cholesky decomposition method
Authors: Huang W.F. , Sun J.P.
Published: March 2018

Typhoon simulation method that integrates typhoon wind field model, probability distributions of typhoon key parameters, and Monte Carlo simulation method has long been used to predict typhoon design wind speeds of structures. In the research, the empirical typhoon wind field model with a novel parameter B model of Holland's radial pressure profile is first introduced and validated with typhoon Hagupit's simulation. The results show that relatively good typhoons can be simulated with this empirical typhoon wind field model. Then, the cholesky decomposition method used in typhoon simulation method is proposed that allows achieving all correlated typhoon key parameters simultaneously. Finally, the cholesky decomposition method is used to generating typhoon key parameters in Hong Kong, and typhoon design wind speeds for different return periods are predicted with typhoon simulation method. In addition, typhoon design wind speeds derived from historical typhoon key parameters and typhoon key parameters generated without considering cholesky decomposition method are also predicted, respectively. The predicted typhoon design wind speeds are compared and the results demonstrate that the cholesky decomposition method should be incorporated into typhoon simulation method.
Students' understanding of the nature and purpose of models
Authors: Gogolin Sarah , Krüger Dirk
Published: March 2018

The process of thinking in and about models as a scientific practice should be integrated into science teaching and learning. Empirical studies show that students see models primarily in their role as media to facilitate content learning while rarely appreciating models as instruments of scientists which allow the deduction and the testing of predictions. In order to foster students' meta‐modeling knowledge successfully, specific diagnostic information about students' understanding of models and modeling is needed. The aim of this study is to gather such diagnostic information by investigating students' understanding of the nature and the purpose of models in biology with respect to context‐ and grade‐specific differences. Students' understanding of the nature and the purpose of models was assessed by using forced choice tasks (Nstudents = 285). In order to gain qualitative insight into possible reasons for context‐specific differences, the students were additionally asked to give reason for their decision in the forced choice tasks by answering open‐ended justification tasks. The results indicate that the majority of students in all grades see models as idealized representations of an original which have the purpose to show or to describe this original. Students' levels of understanding of the nature and the purpose of models increase only little across grades. Nevertheless, a grade‐specific analysis of the consistency of students' understanding across contexts suggests that the students' understanding becomes more consistent in higher grades. Students' justifications helped to identify model contexts which have a high potential to be fruitful when trying to foster students' understanding of the nature and the purpose of models.
Learning progressions as tools for supporting teacher content knowledge and pedagogical content knowledge about water in environmental systems
Authors: Gunckel Kristin L. , Covitt Beth A. , Salinas Ivan
Published: March 2018

Research on learning progressions has led to advances in understanding student learning about big ideas in science, but teachers struggle to leverage the full potential of learning progressions for classroom instruction. Because learning progressions lay out how students' ideas change over a long period of time, learning progressions could help teachers build better understanding of student thinking, appropriate learning goals, and instructional moves for supporting students in developing more sophisticated ideas. In this study, we explored the potential of learning progression‐based curriculum materials to support teachers in developing more sophisticated content knowledge (CK) and pedagocial content knowledge (PCK) for teaching about water in environmental systems. Teachers participated in professional development that introduced them to a learning progression for water in environmental systems and curriculum materials based on this learning progression. Teachers completed written assessments of their CK and PCK prior to the workshops and a year later. Analyses showed that teachers who taught lessons using the learning progression‐based curriculum materials showed modest increases in CK, knowledge of learning goals, and knowledge of student thinking. These increases were greater than analogous changes evident for teachers who did not use the curriculum materials. However, even among those who implemented the curriculum materials, teachers' post‐assessment performance did not yet reflect knowledge for supporting students in developing model‐based reasoning about water. These results show that learning progressions have potential for supporting teacher learning, but that the ubiquity of traditional school science discourse may limit their potential for both student and teacher progress toward model‐based reasoning.
Determinants of Nigerian managers’ environmental attitude: Africa's Ubuntu ethics versus global capitalism
Authors: Okereke Chukwumerije , Vincent Olusegun , Mordi Chima
Published: March 2018

We investigate the impact of economic, institutional, and ethical pressures on African managers' corporate social and environmental attitude based on a survey involving 377 Nigerian executives in the extractive industry. We find that environmental orientation and behavior are mostly induced by instrumental economic motives, while ethical considerations exert a weak impact. This finding is significant because it contradicts mainstream corporate social responsibility (CSR) literature in Africa, which suggests the dominance of the culturally based, altruistic African Ubuntu philosophy. Based on this research finding, we suggest that economic globalization has spurned a transnational capitalist cadre of managers whose values are shaped far more by global capitalist instincts than any putative cultural philosophy. The findings also undercut the fundamental logic underpinning the numerous global initiatives to promote environmental responsibility by multinational corporations in developing countries, which assumes that managers will pursue environmental sustainability voluntarily in the absence of robust regulations and strict enforcement.
Localized tetanus treated with kampo medicines
Authors: Nakae Hajime , Satoh Kasumi , Okuyama Manabu , Furuya Tomoki
Published: March 2018

Case

A 73‐year‐old woman with a history of generalized tetanus and hypertension developed localized tetanus. Daisaikoto (DST) was used to control spasming of cervical muscles given the symptom of tenderness observed on both sides of her abdomen, kyokyo‐kuman. All symptoms except for cheek discomfort were improved. On day 7, shakuyakukanzoto (SKT) was given to control the residual symptoms.

Outcome

Residual symptoms improved after treatment with DST and SKT.

Conclusion

DST can be used for the management of muscle spasms in localized tetanus, based on the oriental medical syndromes.
Books for Two Voices: Fluency Practice With Beginning Readers
Authors: Son Eun Hye , Chase Maggie
Published: March 2018

This article discusses how to implement paired reading with developing readers to foster students’ fluency and reading comprehension. The teacher first helps students comprehend the story with focused discussion questions and the completion of a beginning, middle, and end (B‐M‐E) chart. Then, the teacher scaffolds students to do the oral reading through modeling, guided practice, and independent practice. Students are encouraged to use a fluency self‐assessment rubric to reflect on their reading and think of ways to improve their reading. Once students are familiar with the routine, the teacher can set up a station with a variety of children's books where students can practice paired reading on their own. A bibliography of children's books is provided wherein the two main characters’ dialogue carries the majority of the story and font support is provided to aid in prosody.
Empowering Parents to Encourage Children to Read Beyond the Early Years
Authors: Merga Margaret K. , Mat Roni Saiyidi
Published: March 2018

Enjoyment of reading books is related to reading proficiency, and fostering students’ enjoyment of reading is imperative to support continued reading engagement. However, not all students understand that reading is important, and not all students are regularly engaged in recreational reading. Children typically read for pleasure less often as they age, leading researchers to seek effective ways that social influences can support them to be lifelong readers beyond the early years. Parents can play an important role in communicating the continued importance of reading and fostering positive attitudes toward reading. However, after independent reading skill acquisition, parents may become a less potent encouraging and supportive force. The authors explore older students’ experiences of both independent and shared reading and their perception of parental support, involvement, and modeling to highlight potential roles that parental figures can play in reading beyond the early years.
Comparison of three commercially available placental growth factor‐based tests in women with suspected preterm pre‐eclampsia: the COMPARE study
Authors: McCarthy F. P. , Gill C. , Seed P. T. , Bramham K. , Chappell L. C. , Shennan A. H.
Published: March 2018

Objective

To compare the performance of three placental growth factor (PlGF)‐based tests in predicting delivery within 14 days from testing in women with suspected preterm pre‐eclampsia before 35 weeks' gestation.

Methods

This was a retrospective analysis of samples collected from three prospective pregnancy cohort studies. Participants were pregnant women with suspected preterm pre‐eclampsia recruited in tertiary maternity units in the UK and Ireland. Samples were analyzed simultaneously according to the manufacturers' directions. The tests compared were the DELFIA Xpress PlGF 1‐2‐3 test, the Triage PlGF test and the Elecsys immunoassay soluble fms‐like tyrosine kinase‐1 (sFlt‐1)/PlGF ratio. Areas under receiver–operating characteristics curves (AUCs) were compared. The main outcome measure was detection of a difference of 0.05 in AUC between tests for delivery within 14 days of testing.

Results

Plasma samples from 396 women and serum samples from 244 women were assayed. In predicting delivery within 14 days secondary to suspected pre‐eclampsia prior to 35 weeks' gestation, no significant differences were observed in AUCs (P = 0.795), sensitivities (P = 0.249), positive predictive values (P = 0.765) or negative predictive values (P = 0.920) between the three tests. The specificity of the Elecsys sFlt‐1/PlGF ratio test was higher than that of the other two tests (P < 0.001).

Conclusions

The tests perform similarly in their prediction of need for delivery within 14 days in women with suspected pre‐eclampsia. The high negative predictive values support the role of PlGF‐based tests as ‘rule‐out’ tests for pre‐eclampsia. © 2018 Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.
Correlation between fetoplacental Doppler indices and measurements of cardiac function in term fetuses
Authors: Alsolai A. A. , Bligh L. N. , Greer R. M. , Kumar S.
Published: March 2018

Objective

Redistribution of cardiac output (CO) is responsible for the brain‐sparing effect seen during periods of fetal stress. Our aim was to investigate prospectively the correlation between fetoplacental Doppler indices and measurements of cardiac function in uncomplicated term singleton pregnancy.

Methods

This was a prospective observational study of normotensive women with appropriately grown, non‐anomalous singleton pregnancy. Participants underwent fortnightly ultrasound examinations from 36 weeks' gestation until delivery, and intrapartum and neonatal outcomes were recorded. The correlation between fetoplacental Doppler indices and various measurements of cardiac function was evaluated.

Results

The study cohort comprised 273 singleton pregnancies. The cerebroplacental ratio (CPR) was correlated positively with left ventricular CO (LVCO) (P < 0.001, rho = 0.29), left‐to‐right ventricular CO ratio (LVCO/RVCO; P < 0.001, rho = 0.41), global left ventricular strain (P < 0.01, rho = 0.17) and global right ventricular strain (P < 0.001, rho = 0.22). The CPR was correlated inversely with the left ventricular myocardial performance index (P < 0.01, rho = –0.18) and the RVCO (P < 0.001, rho = –0.28). The LVCO and global left ventricular strain were correlated positively with umbilical venous flow (P = 0.04, rho = 0.18 and P < 0.001, rho = 0.25, respectively). There was minimal or no correlation between either the mean uterine artery pulsatility index (PI) or umbilical artery PI with any cardiac indices.

Conclusion

The fetal CPR, middle cerebral artery PI and umbilical venous flow are correlated positively with LVCO, LVCO/RVCO and global left ventricular strain in low‐risk term pregnancies. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Sliding sign in third‐trimester sonographic evaluation of intra‐abdominal adhesions in women undergoing repeat Cesarean section: a novel technique
Authors: Baron J. , Tirosh D. , Mastrolia S. A. , Ben‐Haroush Y. , Schwartz S. , Kerner Y. , Hershkovitz R.
Published: March 2018

Objective

Intra‐abdominal adhesions are associated with an increased risk of complications during repeat Cesarean section (CS), such as bladder and bowel injury, hemorrhage, infection and hysterectomy. We present a simple sonographic marker, the ‘sliding sign’ of the uterus, for the prediction of intra‐abdominal adhesions in the third trimester of pregnancy in women undergoing repeat CS.

Methods

This was a prospective observational study of pregnant women with a history of at least one Cesarean delivery evaluated by transabdominal ultrasound during the third trimester of an ongoing pregnancy. In order to diagnose intra‐abdominal adhesions, we assessed a sonographic sign, the sliding of the uterus under the inner part of the fascia of the abdominal muscles during deep breathing. Women were considered to be at high risk for severe adhesions if uterine sliding was absent and at low risk in the presence of obvious or moderate uterine sliding. A comparison between sonographic findings and intra‐abdominal adhesions observed during surgery was performed.

Results

Of the 63 patients with one or more previous CS examined, 59 completed the study and underwent CS at our institution. In 16 of the 19 cases assigned to the high‐risk group for severe adhesions due to absence of sliding of the uterus, the suspicion was confirmed at surgery. The prediction of low risk for adhesions was confirmed in 35 out of 40 patients. The sensitivity and specificity of the sliding sign in predicting presence of intra‐abdominal adhesions in women undergoing repeat CS were 76.2% and 92.1%, respectively. Inter‐ and intraobserver correlation using Cohen's kappa coefficient were 0.52 and 0.77, respectively.

Conclusion

Our data show that a simple sonographic sign might be able to discriminate between high and low risk for intra‐abdominal adhesions in patients with a history of Cesarean delivery. This technique may aid clinical decisions in patients undergoing repeat CS. Copyright © 2018 ISUOG. Published by John Wiley & Sons Ltd.
Reinforcement of solution styrene‐butadiene rubber by incorporating hybrids of rice bran carbon and surface modified fumed silica
Authors: Fan Yuan , Li Xiangxu , Jang Sun Ho , Lee Dam Hee , Li Qingyuan , Cho Ur Ryong
Published: March 2018

This study attempts to improve mechanical and material properties by incorporating hybrid fillers of rice bran carbon (RBC) and modified fumed silica (SiO2). The composites of solution‐polymerized styrene butadiene rubber (SSBR) filled with RBC and SiO2 were prepared via a mechanical mixing method. The effect of SiO2 on varying amounts on SSBR composites is illustrated, and the cure characteristics, thermal stability, friction, and mechanical properties are measured. It was discovered that the properties can be enhanced with the addition of SiO2 through mechanical testing. The results show that composites filled with RBC and SiO2‐doped filler exhibited higher tensile strength and hardness compared to those only filled with RBC. J. VINYL ADDIT. TECHNOL., 24:E194–E200, 2018. © 2018 Society of Plastics Engineers