bluuebunny/crossref_metadata_2025 huggingface dataset:
Micro‐phase separation kinetics of polyurethane nanocomposites with neural network
Authors: Sahebi Jouibari Iman , Haddadi‐Asl Vahid , Ahmadi Hanie , Mirhosseini Mohammad Masoud
Published: February 2019

Thermoplastic polyurethane elastomers (TPUs) reinforced with multi wall carbon nanotubes (MWCNTs) and Closite30B, were prepared via melt mixing approach and investigated by spectroscopy, and rheological analyses. Following basic analyses, time sweep tests were used to determine the influence of temperature, applied preshear and nanofiller content and aspect ratio on the micro‐phase separation kinetics of the nanocomposites. Based on the experimental results, artificial neural network was developed to explain the relationship between those parameters and micro‐phase separation time. The neural network is able to predict micro‐phase separation time of TPU nanocomposites possessing different nanofillers at various shear rates and temperatures. Comparison between experimental and calculated data by the model shows that the neural network can well‐communicate between input and target variables. POLYM. COMPOS., 40:3904–3913, 2019. © 2019 Society of Plastics Engineers
The effects of intraband and interband carrier‐carrier scattering on hot‐carrier solar cells: A theoretical study of spectral hole burning, electron‐hole energy transfer, Auger recombination, and impact ionization generation
Authors: Tsai Chin‐Yi
Published: February 2019

The effects of carrier‐carrier scattering resulting from the Coulomb‐potential interaction between two electrons on hot‐carrier solar cells are theoretically studied. Theoretical models and explicit formulas for calculating intraband carrier‐carrier scattering rates, electron‐to‐hole energy transfer rates, Auger recombination rates, and impact ionization generation rates are presented and derived. The numerical calculations from these formulas are obtained, and their effects on hot‐carrier solar cells are investigated. Several findings can be concluded from this study: (1) Intraband electron‐electron scattering and hole‐hole scattering are normally fast enough to randomize carrier distribution in the momentum space and thus maintain quasiequilibrium to establish electron and hole temperatures at a steady state; (2) spectral hole burning in hot‐carrier solar cells can be incurred by fast carrier extraction processes through energy‐selective contacts and slow intraband carrier‐carrier scattering; (3) energy transfer between electrons and holes via intraband electron‐hole scattering cannot guarantee that electrons and holes will maintain the same carrier temperature for hot‐carrier solar cells in all cases, especially if the difference between electron and hole temperatures is smaller than 100 K; and (4) materials with a band‐gap energy larger than 1 eV are favorable as conventional solar cells in which Auger recombination is not significant. On the contrary, materials with a band‐gap energy smaller than 0.5 eV are not suitable for conventional solar cells due to the detrimental effects of Auger recombination. However, they are ideal materials for realizing hot‐carrier solar cells due to beneficial effects of impact ionization generation, although these beneficial effects can be undermined by spectral hole burning.
The Role of the Headmaster Collar (Cervical) for Dropped Head Syndrome in Hodgkin Lymphoma Survivors
Authors: Kim Arum , Stubblefield Michael D.
Published: February 2019

Background

Dropped head syndrome is a potential late neurologic complication of radiation therapy in survivors of Hodgkin lymphoma. There is limited evidence for conservative management of this condition.

Objective

To discover patient utilization patterns of the commonly prescribed Headmaster Collar (cervical) in Hodgkin lymphoma survivors with radiation‐induced dropped head syndrome.

Design

Questionnaire‐based retrospective observational study.

Setting

Single‐site academic cancer center.

Patients

Twenty‐six Hodgkin lymphoma survivors treated with radiation therapy involving the mantle who were prescribed a Headmaster Collar for dropped head syndrome.

Methods or Interventions

Patients were interviewed by phone with a structured set of questions.

Main Outcome Measurements

Compliance, patterns of use, individual modifications, and side effects of collar use.

Results

Although 58% of patients who were prescribed a Headmaster Collar eventually discontinued its use, 62% of all patients used the collar for more than 6 months. The majority of users wore the collar for up to 3 hours per day, usually for static seated activities. Thirty‐eight percent of patients made personal modifications to their collar, most commonly the addition of extra padding. All but one patient had complaints about the collar, most commonly discomfort, rigidity, and confinement.

Conclusions

The Headmaster Collar (cervical) is often utilized for a few hours a day, for longer than 6 months, to help with static seated activities. Insights from this study might help to improve future orthotic designs with better long‐term compliance rates for the treatment of radiation‐induced dropped head syndrome.

Level of Evidence

IV
Optoelectronic and charge‐transport properties of truxene, isotruxene, and its heteroatomic (N, O, Si, and S) analogs: A DFT study
Authors: Tripathi Anuj , Prabhakar Chetti
Published: February 2019

The main objective of this work is to provide a detailed study of optoelectronic and charge‐transport properties of truxene, isotruxene, and their heteroatomic analogs (azatruxene and isoazatruxene, oxatruxene and isooxatruxene, silatruxene and isosilatruxene, and thiatruxene and isothiatruxene). Systematic studies of these molecules were performed by means of the density functional theory (DFT) and time‐dependent DFT (TD‐DFT) calculations. Electronic excitations (absorption spectra), reorganization energies (hole‐ and electron‐transport properties), electron affinities (EAs), ionization potentials (IPs), hole extraction potentials (HEPs), and electron extraction potentials (EEPs) for all the molecules were reported. Based on the comparative study, it is showed that thiatruxenes (isothiatruxene) are better hole‐transport materials than other truxene (isotruxene) analogs.
Crystal structure of the apo form of a β‐transaminase from Mesorhizobium sp. strain LUK
Authors: Kwon Sunghark , Park Hyun H.
Published: February 2019

Pyridoxal 5′‐phosphate (PLP)‐dependent β‐transaminases (βTAs) reversibly catalyze transamination reactions by recognizing amino groups linked to the β‐carbon atoms of their substrates. Although several βTA structures have been determined as holo forms containing PLP, little is known about the effect of PLP on the conversion of the apo structure to the holo structure. We determined the crystal structure of the apo form of a βTA from Mesorhizobium sp. strain LUK at 2.2 Å resolution to elucidate how PLP affects the βTA structure. The structure revealed three major disordered regions near the active site. Structural comparison with the holo form also showed that the disordered regions in the apo form are ordered and partially adopt secondary structures in the holo form. These findings suggest that PLP incorporation into the active site contributes to the structural stability of the active site architecture, thereby forming the complete active site. Our results provide novel structural insights into the role of PLP in terms of active site formation.
Evaluation of a noncanonical Cys40‐Cys55 disulfide linkage for stabilization of single‐domain antibodies
Authors: Kim Dae Young , Kandalaft Hiba , Hussack Greg , Raphael Shalini , Ding Wen , Kelly John F. , Henry Kevin A. , Tanha Jamshid
Published: February 2019

Incorporation of noncanonical disulfide linkages into single‐domain antibodies (sdAbs) has been shown to enhance thermostability and other properties. Here, we evaluated the effects of introducing a novel disulfide linkage formed between Cys residues at IMGT positions 40 and 55 on the melting temperatures (T
ms), reversibility of thermal unfolding, solubility, and antigen‐binding affinities of three types of sdAbs (VHH, VH, and VL domains). The Cys40‐Cys55 disulfide linkage was tolerated by 9/9 VHHs, 12/12 VHs, and 2/11 VLs tested and its formation was confirmed by mass spectrometry. Using circular dichroism, we found that the Cys40‐Cys55 disulfide linkage increased sdAb T
m by an average of 10.0°C (range: 0–21.8°C). However, enhanced thermostability came at the cost of a partial loss of refolding ability upon thermal denaturation as well as, for some sdAbs, significantly decreased solubility and antigen‐binding affinity. Thus, Cys40/Cys55 can be added to the panel of known locations for introducing stabilizing noncanonical disulfide linkages into antibody variable domains, although its effects should be tested empirically for individual sdAbs.
A review of progress toward field application of transgenic mosquitocidal entomopathogenic fungi
Authors: Lovett Brian , Bilgo Etienne , Diabate Abdoulaye , St. Leger Raymond
Published: February 2019

In Africa, adult mosquito populations are primarily controlled with insecticide‐impregnated bed nets and residual insecticide sprays. This coupled with widespread applications of pesticides in agriculture has led to increasing insecticide resistance in mosquito populations. We have developed multiple alternative strategies for exploiting transgenic Metarhizium spp. directed at: (i) shortening the lifespan of adult mosquitoes; (ii) reducing transmission potential of Plasmodium spp.; (iii) reducing vector competence via pre‐lethal effects. The present challenge is to convert this promising strategy into a validated public health intervention by resolving outstanding issues related to the release of genetically modified organisms. © 2019 Society of Chemical Industry
Polycrystalline SnO2 Visible‐Light‐Transparent CO2 Sensor Integrated with NiO/ZnO Solar Cell for Self‐Powered Devices
Authors: Tanuma Ryo , Sugiyama Mutsumi
Published: February 2019

Monolithic visible‐light‐transparent carbon dioxide (CO2) sensor/solar cell‐integrated devices are fabricated using RF sputtering. The optical transmittance of the integrated device in the visible region is found to be over 60%. The solar cell is composed of p‐type NiO and n‐type ZnO layers, and exhibits small but noticeable photovoltaic effect under illumination. The CO2 sensor layer is made from LaOCl/SnO2 layers, and its resistance varies when electrical power is supplied from an external power source. XPS measurement reveals that adsorbed oxygen, which influences the sensitivity of gas sensors, increases with increasing LaOCl catalyst concentration. The results of this study can serve as a first step toward achieving a new type of visible‐light‐transparent CO2 sensor/UV absorbed solar cell for integrated self‐powered devices.
Electrically Controlled Actuation of Strained Nanomembranes
Authors: Enderlein Tom , Nestler Jörg , Stiehl Cornelia , Morschhauser Andreas , Otto Thomas
Published: February 2019

Strained nanomembranes can, if released from a substrate, form tubular devices and other 3D‐objects for various sensor and actuator applications. In this study, controlled release and thus the actuation of strained nanomembranes by dissolving a sacrificial layer in a liquid environment by an electrical current is investigated and integrated tubular structures in microfluidic chips are demonstrated. Besides the mere generation of tubular devices, the utilization of an electrical current for the actuation of strained nanomembranes makes this approach ideal for the integration in advanced Lab‐on‐a‐Chip systems. Some of the advantages to current methods are: the ability to actuate the membranes in a triggered and speed controllable fashion; in case of applications in liquid environments, no need of transferring or drying the tubular devices; fabrication is carried out by typical wafer level MEMS‐processes. The fabricated demonstrator chips are composed of Borofloat borosilicate float glass substrates, a sputtered metal sacrificial layer, a strained nanomembrane layer and a polymer based liquid reservoir or channel system. The actuation concept is investigated for different electrical currents and voltages, layer material combinations and a range of widths and diameters of the tubular structures. Likewise the influence of different electrolytic liquids and liquid confinements are studied.
Accessing Metastability in Heterostructural Semiconductor Alloys
Authors: Siol Sebastian
Published: February 2019

The increasing demand for novel inorganic materials with targeted functionality motivates moving beyond the area of traditionally explored near‐equilibrium materials by incorporating metastable phase space into materials design and discovery. It has recently been shown that heterostructural semiconductor alloys can exhibit increased regions of metastable phase space as compared to their isostructural counterparts. This phase space is accessible using non‐equilibrium deposition techniques, providing ample opportunities for the synthesis of novel, metastable, single‐phase alloys. In addition, the composition‐dependent structural transitions in heterostructural systems provide additional degrees of freedom for the tuning of functional properties. This perspective gives insight into the design of heterostructural semiconductor alloys and highlights their potential for future materials discovery. It is shown how combinatorial, non‐equilibrium physical vapor deposition can be used to effectively screen and access previously uncharted metastable phase space in such systems. In addition, it is demonstrated how differences in mixing enthalpies for different structures can be utilized to stabilize new alloy polymorphs with useful properties that cannot be found in either of the alloying endmembers. Finally, it is discussed how this conceptual approach can be used to screen high‐throughput computational databases, potentially revealing numerous materials systems where such novel metastable polymorphs can be discovered.
Exciton‐Polariton Wave‐Packets in Semiconductor Microwires
Authors: Egorov Oleg A. , Etrich Christoph , Buschlinger Robert , Peschel Ulf
Published: February 2019

The physics behind nonlinear propagation of picosecond pulses in micro‐ and nano‐wire single mode waveguides either grown by chemical vapor deposition or etched into semiconductor microresonators are reviewed. If operated in the strong coupling regime exciton‐polaritons form in those wires and a highly nonlinear platform is established interfacing optical, condensed matter, quantum, and statistical physics. A theory of the exciton‐polariton pulse compression, pulse breaking, and emission of the backward Cherenkov radiation have been developed. This highly nonlinear dynamics is associated with the relaxation of the exciton‐polariton spectrum down to low momenta, mediated solely by the exciton–exciton scattering. Such nonlinearity‐enhanced thermalization results in a phase transition from propagating exciton‐polariton pulses toward the formation of a non‐equilibrium polariton condensate in the microwire system.
Assessment of GPM high‐frequency microwave measurements with radiative transfer simulation under snowfall conditions
Authors: Yin Mengtao , Liu Guosheng
Published: February 2019

The Global Precipitation Mission (GPM) Microwave Imager (GMI) has four channels at 166 and 183 GHz that provide critical information on snow precipitation. Since the applications of these high‐frequency microwave channels to snowfall prediction and retrieval are still in a very early stage, it is important to evaluate the biases between observed and simulated brightness temperatures for those channels under snowfall conditions. A radiative transfer model that supports the computation of single‐scattering properties for non‐spherical snow particles is employed to simulate GMI brightness temperatures. Snow water content profiles are first derived from the CloudSat Cloud Profiling Radar (CPR) measurements and then used as input to the radiative transfer model. Results show that the biases of observed minus simulated brightness temperatures for GMI channels averaged over all selected pixels are generally less than 1 K under snowfall conditions, except for the 166 GHz horizontal polarization (166H) channel that has a bias of about 3 K. Larger biases are observed under snowfall conditions when the scene brightness temperatures are low. Further investigation indicates that the GMI remaining biases are often associated with shallow snow cells or deep convective clouds. We hypothesize that in shallow snow cells the errors in retrieved cloud liquid water likely contribute to the large bias for the GMI 166H channel, while in deep convective clouds the attenuation in CPR radar reflectivities and possible sampling bias likely cause the biases for GMI channels under low scene brightness temperatures. This study lays out an applicable configuration in simulating microwave brightness temperatures at high frequency under snowfall conditions, and the explanation provided for the GMI remaining biases at 166 and 183 GHz are useful for future applications of these channels.
Probing molecular environments with a fictitious isotopic dipole
Authors: Mohallem José R. , Velloso Paulo F. G. , Arapiraca Antonio F. C.
Published: February 2019

A HD‐like (HD: mono‐deuterated hydrogen molecule) isotopic dipole moment is proposed as a sensible probe for molecular environments, in particular for electrostatic fields and polarizable (reactive) sites of molecules. Fictitious nuclear masses are chosen in order to yield a rigid dipole with a small appropriate magnitude. Upon subtracting the Born‐Oppenheimer energy, the interaction is reduced to field‐dipole‐like and dipole‐polarizability‐like terms, the last one being particularly informative since connected to potentially reactive sites. Possible asymmetries of this term appear as signatures of charged sites in the molecule. The field strength and orientation are easily obtained by identifying the minimum field‐dipole energy configuration and flipping the dipole from it. Tests with hydrogen, water, benzene, and chlorobenzene molecules confirm the good performance of the method. In an application to test the present models for hydrogen activation by a frustrated Lewis pair, the full potential of the method is assessed.
Design, Synthesis and Biological Evaluation of Substituted (1‐(4‐chlorobenzyl)‐1H‐indol‐3‐yl) 1H‐(1,2,3‐triazol‐4‐yl)methanones as Antifungal Agents
Authors: Shareef Mohd Adil , Rajpurohit Hemshikha , Sirisha K. , Sayeed Ibrahim Bin , Khan Irfan , Kadagathur Manasa , Ganapathi Thipparapu , Kumar C. Ganesh , Kamal Ahmed , Babu Bathini Nagendra
Published: February 2019

In the perusal of our endeavour towards the synthesis of new bioactive agents, a new series of substituted (1‐(4‐chlorobenzyl)‐1H‐indol‐3‐yl) 1H‐(1,2,3‐triazol‐4‐yl) methanones (8a‐u) were designed, synthesized and investigated for their antimicrobial activity with special emphasis on their anti‐Candida potential and Candida biofilm inhibition. Among them, the hybrids 8e, 8f, and 8o demonstrated significant antifungal activity on most of the tested fungal strains with MIC values ranging between 1.9–7.8 μg/mL. In addition, the most promising compounds were found to be effective biofilm inhibitors. We have studied the Field emission Scanning Electron Microscope (FE‐SEM) micrographs for 8f to know the damage of the cells with altered membrane integrity and release of intracellular contents thereby validating the in vitro biofilm inhibition assay. Further, in enzymatic assay, active compounds inhibited ergosterol biosynthesis. Furthermore, docking studies revealed that they effectively bind to 14α‐demethylase (CYP51), thereby inhibiting ergosterol biosynthesis. Interestingly, they exhibited lower cytotoxicity in the normal cell line (MRC5).
Facile and Green One‐Pot Synthesis of Fluorophore Chromeno[4,3‐b]quinolin‐6‐one Derivatives Catalyzed by Halloysite Nanoclay under Solvent‐free Conditions
Authors: Ataee‐Kachouei Tahereh , Nasr‐Esfahani Mahboobeh , Baltork Iraj Mohammadpoor‐ , Mirkhani Valiollah , Moghadam Majid , Tangestaninejad Shahram , Kia Reza
Published: February 2019

In this study, we demonstrated a straightforward method for the easy access of chromeno[4,3‐b]quinolin‐6‐ones via a one‐pot three‐component reaction of 4‐hydroxycoumarin, aldehydes and aryl amines in the presence of halloysite nanoclay as an eco‐friendly, inexpensive and green heterogeneous catalyst under solvent‐free conditions. Moreover, symmetric and unsymmetric bis‐chromeno[4,3‐b]quinolin‐6‐ones were obtained from dialdehyde or diamines in good yields by this method. To date, this is the first report on the synthesis of symmetric and unsymmetric bis‐chromeno[4,3‐b]quinolin‐6‐ones via such a one‐pot, multicomponent reaction. Some prepared chromeno[4,3‐b]quinolin‐6‐ones displayed as interesting fluorophore compounds, hereupon their fluorescence properties were considered. Good to excellent yields, short reaction times and avoidance of toxic solvents are the significant features of this green procedure.
Size‐Control and Surface Modification of Flexible Metal‐Organic Framework MIL‐53(Fe) by Polyethyleneglycol for 5‐ Fluorouracil Anticancer Drug Delivery
Authors: Nguyen Thi Hoai Phuong , Ninh Ha Duc , Tran Chinh Van , Le Bac Thanh , Bhosale Sheshanath V. , La Duong Duc
Published: February 2019

The flexible metal‐organic frameworks (MOFs) materials, also called soft porous crystals which combine the crystalline order of the underlying coordination network with cooperative structural transformability, have been extensively studied as promising materials for various applications such as sensing, drug delivery, catalysis, host‐guest complex etc. Among them MOFs is effectively used as a carrier for drug delivery. Herein, a flexible metal‐organic framework MIL‐53(Fe) functionalized with polyethyleneglycol (PEG) was successfully fabricated by ultrasonication. The prepared material was characterized by scanning electron microscopy (SEM), X‐ray diffraction (XRD), transmittance electron microscopy (TEM), Brunauer‐Emmett‐Teller (BET) surface area and infrared spectroscopy (IR). The effect of the PEG content on the morphology and particles size of the MIL‐53 was investigated in detail. The resultant flexible MIL‐53(Fe)‐PEG materials were seen to be homogeneous with the morphology of hexagonal bipyramidal structure, approximately 700 nm in length and 400 nm in diameter. Furthermore, we investigated loading of 5‐fluorouracil (5‐FU) drug and its release in vitro conditions by employing MIL‐53(Fe)‐PEG. The results showed that in vitro condition, only 31% of the drug released after 3 h, and released completely after approximately 6 days. Thus, we believe that use of MIL‐53(Fe)‐PEG may overcome current issue of sustain release.
A Facile One Pot Synthesis of Cu2O@TiO2: A Nanocomposite Catalyst for Enhanced Visible Light Driven Photocatalysis#
Authors: Surikanti Ganesh Reddy , Bandarapu Arun Kumar , Sunkara Manorama V.
Published: February 2019

The highlight of this study is a successful attempt to obtain a visible light active photo catalyst by a single step synthesis procedure. The photocatalytic performance of Cu2O, a p‐type semiconducting oxide with a band gap in the visible region of the solar spectrum is improved by the presence of TiO2 on its surface. Nanocomposites of Cu2O@TiO2 were synthesized by a facile one pot synthesis route. X‐ray diffraction (XRD) studies confirmed the face centred cubic structure of Cu2O but was inconclusive about the TiO2 presence. Field Emission Scanning Electron Microscopy (FE‐SEM) images confirmed the octahedral morphology of the Cu2O particles and the presence of Ti and O on the surface. High Resolution Transmission Electron Microscopy (HR‐TEM) and Selected Area Electron Diffraction (SAED) studies established the presence of nanocrystalline anatase TiO2 on the Cu2O interfaces. The specific role of the nanoparticles of n‐type TiO2 positioned on the p‐type Cu2O in improving photo‐activity and making it visible light active was demonstrated. The photocatalytic activity of the composite was demonstrated by the degradation of a model dye Rhodamine B using visible light. It is observed that the photocatalytic activity is dependent on density of heterojunctions formed in the photo‐system which the nano‐crystalline TiO2 , has very effectively created on the Cu2O surface, which are responsible for the improved photocatalytic response. This work establishes that the in‐situ creation of Cu2O@TiO2 is effective in creating p‐n heterojunctions at the Cu2O@TiO2 interface, which result in arresting the recombination processes, leading to improved photocatalytic performance.
Transducing Protease Activity into DNA Output for Developing Smart Bionanosensors
Authors: Bui Hieu , Brown Carl W. , Buckhout‐White Susan , Díaz Sebastián A. , Stewart Michael H. , Susumu Kimihiro , Oh Eunkeu , Ancona Mario G. , Goldman Ellen R. , Medintz Igor L.
Published: February 2019

DNA can process information through sequence‐based reorganization but cannot typically receive input information from most biological processes and translate that into DNA compatible language. Coupling DNA to a substrate responsive to biological events can address this limitation. A two‐component sensor incorporating a chimeric peptide‐DNA substrate is evaluated here as a protease‐to‐DNA signal convertor which transduces protease activity through DNA gates that discriminate between different input proteases. Acceptor dye‐labeled peptide‐DNAs are assembled onto semiconductor quantum dot (QD) donors as the input gate. Addition of trypsin or chymotrypsin cleaves their cognate peptide sequence altering the efficiency of Förster resonance energy transfer (FRET) with the QD and frees a DNA output which interacts with a tetrahedral output gate. Downstream output gate rearrangement results in FRET sensitization of a new acceptor dye. Following characterization of component assembly and optimization of individual steps, sensor ability to discriminate between the two proteases is confirmed along with effects from joint interactions where potential for cross‐talk is highest. Processing multiple bits of information for a sensing outcome provides more confidence than relying on a single change especially for the discrimination between different targets. Coupling other substrates to DNA that respond similarly could help target other types of enzymes.
Chlorobenzene: A Processing Solvent Enabling the Fabrication of Perovskite Solar Cells with Consecutive Double‐Perovskite and Perovskite/Organic Semiconductor Bulk Heterojunction Layers
Authors: Wang Jiandong , Yao Xiang , Xiao Wen‐Jing , Bai Yang , Xu Zi‐Wen , Lin Jian , Li Wei‐Shi
Published: February 2019

Chlorobenzene (CB), which has been used as an anti‐solvent, is demonstrated here as a processing solvent for the fabrication of perovskite films and solar cells. This approach results from the unexpected finding that butylamine‐bound organolead iodides can be dissolved in CB to form precursor solutions. Together with previously established perovskite composition transformation methods, not only conventionally structured perovskite solar cells (PSCs) with a (CH3NH3)PbI3active layer but also nonconventionally structured devices with a consecutive (CH3NH3)PbI3/(C4H9NH3)2PbI4double layer or a mixed poly(triaryl amine) (PTAA) and (CH3NH3)PbI3bulk heterojunction layer are successfully prepared and demonstrated with an optimal efficiency of 16.44%. This is the first time that nonpolar solvents are used for perovskite material processing, which can remove the solvent limitation and open a new avenue for designing and preparing perovskite devices with desired structures.
Compression Deformation Behavior of a Fe–26Mn–7Al–1.3C Austenitic Steel after Precipitation‐Hardened Treatment
Authors: Feng Yifan , Song Renbo , Liu Shuai , Tan Zhidong , Peng Shiguang , Dou Guoyu
Published: February 2019

Room temperature compression deformation behavior of a Fe–26Mn–7Al–1.3C austenitic steel in association with deformation microstructures is investigated in the article. After isothermal annealing at 550 °C for 2 h, a substantial nano‐sized κ‐carbides are precipitated within the austenite matrix. The precipitation‐hardened steel obtains an excellent combination of yield strength and toughness (product over 97 000 MPa J cm−2) associated with multiple‐stage strain hardening. In order to clarify the chief deformation mechanism, deformation microstructures are analyzed at different strain levels by means of transmission electron microscopy (TEM). TEM results show that the deformation microstructures exhibit the typical planar glide characteristics due to “glide plane softening” effect in spite of the high SFE (≈72 mJ m−2) for current steel. Some specific planar dislocation configurations including Taylor lattices and micro‐bands are contributed to high constant strain hardening rate. However, at high strain, intersections of highly localized nature micro‐bands decrease the formation activity of slip bands, meanwhile, the interaction between κ‐carbides and dislocation cross‐slip becomes more intensive, which results in a decrease in the growth rate of dislocations due to the frequency of dislocation annihilation.
Experimental method for investigating the impact of the addition of polymer fibers on drying shrinkage and cracking of concretes
Authors: Ehrenbring Hinoel Z. , de Medeiros Quinino Uziel C. , Oliveira Luis F. S. , Tutikian Bernardo F.
Published: February 2019

This study presents an investigation of a fiber‐reinforced concrete (FRC) with use of fibers of polypropylene, polyvinyl alcohol, and recycled polyester in the amount of 0.50%, seeking to analyze the impact of the fiber additions on mechanical properties, drying shrinkage, and cracking. Regarding flexural strength, a reduction of up to 25% of the value was observed for FRC. The residual strength of FRCs was increased values 20 times higher than the reference concrete. The addition of fibers also increased the void content of the matrices and, therefore, drying shrinkage of the reference matrix up to 74%. The fiber additions increased the internal tensile stresses of the FRC of up to 12.0 MPa. Besides the increase in resistance, the FRC presented formation cracks with openings 8 times smaller than the concrete.
The development of students' justifications for their positions regarding two theoretical models: Electron cloud or sodium chloride crystal—After engaging in different learning activities
Authors: Al‐Balushi Sulaiman M. , Martin‐Hansen Lisa
Published: February 2019

The purpose of this study was to explore high school students' ideas regarding two theoretical scientific models, either electron cloud or sodium chloride crystal, in the context of active learning in small groups. Conversations among peers regarding these models took place during two types of active learning activities: small‐group discussion and whole‐class debate. The study was conducted in four different high school classes, each of which was in a different school for girls in Oman. The study included 108 grade 10 female students. Two of the classes discussed the electron cloud and the other two classes discussed the sodium chloride model. Qualitative data included students' written responses to prompts, class worksheets, and field notes of student ideas in class debates. In each class, the teacher used a teaching sequence during which the participants expressed their justifications for their positions in writing regarding the particular model on five different occasions, as they progressed through three interactive small group learning activities. The participants' written responses were analyzed using a coding scheme comprising of eight different categories describing the participants' type of justifications regarding the theoretical scientific models: nonsense, approval, mental, experimental, appreciative, external, structural, and modeling. The findings indicated that participants' justifications for their positions regarding theoretical scientific models tended to change over time following each group learning activity. Participants focused their discussion more on external factors, such as the teacher, textbook, religion, and media, after discussions with peers in small groups. In contrast, later their attention focused more on the submicroscopic structural orientations of the model under study during and after engaging in a debating activity. The researchers reasoned that the nature of cognitive demands during each type of active learning activity might play a role in this regard. However, further research to advance the understanding of this phenomenon is needed.
Learning natural selection through computational thinking: Unplugged design of algorithmic explanations
Authors: Peel Amanda , Sadler Troy D. , Friedrichsen Patricia
Published: February 2019

Computational thinking (CT) is a way of making sense of the natural world and problem solving with computer science concepts and skills. Although CT and science integrations have been called for in the literature, empirical investigations of such integrations are lacking. Prior work in natural selection education indicates students struggle to explain natural selection in different contexts and natural selection misconceptions are common. In this mixed methods study, secondary honors biology students learn natural selection through CT by engaging in the design of unplugged algorithmic explanations. Students learned CT principles and practices and applied them to learn and explain the natural selection process. Algorithmic explanations were used to scaffold transfer of natural selection knowledge across contexts through investigation of three organisms and the creation of generalized natural selection algorithms. Students' pre‐ and post‐unit algorithmic explanations of natural selection were analyzed to answer the following research questions: (a) How do students' conceptions of natural selection change over the course of a CT focused unit? (b) What is the relationship between CT and natural selection in students' algorithmic explanations? (c) What are students' perspectives of learning natural selection with CT? Results indicate students' conceptions of natural selection increased and natural selection misconceptions decreased over the course of the unit. Within their post‐unit algorithmic explanations, students used specific CT principles in conjunction with natural selection concepts to explain natural selection, which helped them to learn the details of the natural selection process and correct their natural selection misconceptions. Students indicated the use of CT in unplugged algorithmic explanations in different contexts helped them learn natural selection. This study shows unplugged CT can be used to teach students science content, and it provides an example for further CT and science integrations. Implications for the field are discussed.
Effect of debate on development of adaptability in EFL university classrooms
Authors: Kudinova Natalia , Arzhadeeva Daria
Published: February 2019

This article focuses on the issue of adaptability in the field of education, particularly English as a foreign language teaching, and explores the question of whether academic debate can foster adaptability among university first‐year university students majoring in science, technology, engineering, or mathematics. To answer that, the authors designed and conducted a study in 2017 and 2018 at a university in Moscow, Russia. The study involved two groups of students: those who attended regular English classes and those who, apart from regular classes, weekly attended and actively participated in specially designed English debate classes. To evaluate whether any alterations to the students’ adaptability level occurred, teacher‐assessors completed the Adaptability Scale at the beginning and end of the project. In addition, the students were asked to fill out a self‐assessment questionnaire to rate their own adaptability development. The results of the control and experimental groups were compared and a series of t‐tests was conducted. The findings reveal that, in the experimental group, English debate classes fostered positive growth in the level of adaptability, and all its components experienced a significant enhancement.
Objective tongue color and gastroesophageal reflux disease: Cross‐sectional study
Authors: Kainuma Mosaburo , Furusyo Norihiro , Urita Yoshihisa , Ikezaki Hiroaki , Ura Kazuya , Nakaguchi Toshiya , Namiki Takao
Published: February 2019

Aim

Gastroesophageal reflux disease (GERD) is a heterogeneous, multi‐symptom disease. The Frequency Scale for the Symptoms of GERD (FSSG) is used to evaluate the disease severity and therapeutic response. We reported that objective tongue diagnosis would be a useful, non‐invasive screening tool for erosive gastritis, which makes it a useful complement to Kampo diagnosis. This study was done to investigate the utility of tongue color (TC) and FSSG in the diagnosis of GERD.

Methods

A total of 886 healthy Japanese residents aged 28–86 years had a photograph of the tongue taken, completed the FSSG, and underwent esophagogastroduodenoscopy. FSSG ≥8 was defined as GERD, mucosal break on endoscopy as reflux esophagitis (RE), and no erosive esophagitis as non‐erosive reflux disease (NERD). TC was measured using the device‐independent International Commission on Illumination (CIE) 1976 L*a*b* color space standards at four points.

Results

A total of 152 (17.2%) of the subjects had FSSG ≥8. On endoscopy 36 (4.1%) had RE and 116 (13.1%) had NERD. Age, sex, and smoking were significant in the multivariate analysis of GERD (OR, 0.64, P = 0.043; OR, 0.65, P = 0.036; and OR, 2.06, P = 0.014, respectively). Sex and TC (3b*/1b*) were significant in the multivariate analysis of RE (OR, 4.82, P < 0.001; OR, 3.59, P = 0.018, respectively). On receiver operating characteristics analysis, a combination of sex (male) and TC (3b*/1b*) ≥1.24 was more predictive of RE than sex (male) alone (area under the curve, 0.75 vs 0.70).

Conclusion

Combining FSSG ≥8, sex, and a positive tongue color coating would be a useful, accurate, non‐invasive screening method for GERD, especially RE.
Double-real contribution to the quark beam function at N3LO QCD
Authors: Melnikov K. , Rietkerk R. , Tancredi L. , Wever C.
Published: February 2019

Abstract

We compute the master integrals required for the calculation of the double-real emission contributions to the matching coefficients of 0-jettiness beam functions at nextto-next-to-next-to-leading order in perturbative QCD. As an application, we combine these integrals and derive the double-real gluon emission contribution to the matching coefficient I

qq
(t, z) of the quark beam function.
The analytic functional bootstrap. Part II. Natural bases for the crossing equation
Authors: Mazáč Dalimil , Paulos Miguel F.
Published: February 2019

Abstract

We clarify the relationships between different approaches to the conformal bootstrap. A central role is played by the so-called extremal functionals. They are linear functionals acting on the crossing equation which are directly responsible for the optimal bounds of the numerical bootstrap. We explain in detail that the extremal functionals probe the Regge limit. We construct two complete sets of extremal functionals for the crossing equation specialized to

$$ z=\overline{z} $$

z
=

z
¯

, associated to the generalized free boson and fermion theories. These functionals lead to non-perturbative sum rules on the CFT data which automatically incorporate Regge boundedness of physical correlators. The sum rules imply universal properties of the OPE at large Δ in every unitary solution of SL(2) crossing. In particular, we prove an upper and lower bound on a weighted sum of OPE coefficients present between consecutive generalized free field dimensions. The lower bound implies the ϕ × ϕ OPE must contain at least one primary in the interval [2Δ
ϕ
+ 2n, 2Δ
ϕ
+ 2n + 4] for all sufficiently large integer n. The functionals directly compute the OPE decomposition of crossing-symmetrized Witten exchange diagrams in AdS
2. Therefore, they provide a derivation of the Polyakov bootstrap for SL(2), in particular fixing the so-called contact-term ambiguity. We also use the resulting sum rules to bootstrap several Witten diagrams in AdS
2 up to two loops.
Effective field theory amplitudes the on-shell way: scalar and vector couplings to gluons
Authors: Shadmi Yael , Weiss Yaniv
Published: February 2019

Abstract

We use on-shell methods to calculate tree-level effective field theory (EFT) amplitudes, with no reference to the EFT operators. Lorentz symmetry, unitarity and Bose statistics determine the allowed kinematical structures. As a by-product, the number of independent EFT operators simply follows from the set of polynomials in the Mandelstam invariants, subject to kinematical constraints. We demonstrate this approach by calculating several amplitudes with a massive, SM-singlet, scalar (h) or vector (Z
′) particle coupled to gluons. Specifically, we calculate hggg, hhgg and Z
′
ggg amplitudes, which are relevant for the LHC production and three-gluon decays of the massive particle. We then use the results to derive the massless-Z
′ amplitudes, and show how the massive amplitudes decompose into the massless-vector plus scalar amplitudes. Amplitudes with the gluons replaced by photons are straightforwardly obtained from the above.
Psychometric Properties of Child (0–5 Years) Outcome Measures as used in Randomized Controlled Trials of Parent Programs: A Systematic Review
Authors: Gridley Nicole , Blower Sarah , Dunn Abby , Bywater Tracey , Bryant Maria
Published: February 2019

This systematic review is one of the three which sought to identify measures commonly implemented in parenting program research, and to assess the level of psychometric evidence available for their use with this age group. This review focuses specifically on measures of child social–emotional and behavioral outcomes. Two separate searches of the same databases were conducted; firstly to identify eligible instruments, and secondly to identify studies reporting on the psychometric properties of the identified measures. Five commercial platforms hosting 19 electronic databases were searched from their inception to conducted search dates. Twenty-four measures were identified from Search 1: a systematic search of randomized controlled trial evaluations of parenting programs. For Search 2, inclusion/exclusion criteria were applied to 21,329 articles that described the development and/or validation of the 24 measures identified in Search 1. Thirty articles met the inclusion criteria. resulting in 11 parent report questionnaires and three developmental assessment measures for review. Data were extracted and synthesized to describe the methodological quality of each article using the COSMIN checklist alongside the overall quality rating of the psychometric property reported for each measure. Measure reliability was categorized into four domains (internal consistency, test–re-test, inter-rater, and intra-rater). Measure validity was categorized into four domains (content, structural, convergent/divergent, and discriminant). Results indicated that supporting evidence for included measures is weak. Further work is required to improve the evidence base for those measures designed to assess children’s social–emotional and behavioral development in this age group. PROSPERO Registration number: CRD42016039600.
Epidemiology is ecosystem science
Authors: Lee Keekok
Published: February 2019

This paper primarily argues that Epidemiology is Ecosystem Science. It will not only explore this notion in detail but will also relate it to the argument that Classical Chinese Medicine was/is Ecosystem Science. Ecosystem Science (as instantiated by Epidemiology) and Ecosystem Science (as instantiated by Classical Chinese Medicine) share these characteristics: (a) they do not subscribe to the monogenic conception of disease; (b) they involve multi variables; (c) the model of causality presupposed is multi-factorial as well as non-linear.
Does Mindful Parenting Mediate the Association between Maternal Anxiety during Pregnancy and Child Behavioral/Emotional Problems?
Authors: Henrichs Jens , van den Heuvel Marion I. , Witteveen Anke B. , Wilschut Janneke , Van den Bergh Bea R. H.
Published: February 2019

Objectives

Maternal anxiety during pregnancy is a risk factor for child behavioral/emotional problems. Knowledge about explanatory factors mediating this link is scarce. Maternal anxiety during pregnancy may be an indicator of adverse postnatal environmental conditions, including maternal anxiety and poor parenting, possibly affecting child behavior. This study investigated whether maternal anxiety and mindful parenting in early childhood mediate the association between maternal anxiety during pregnancy and child behavioral/emotional problems.

Methods

This study was based on a sample of 118 mother-child dyads who participated in a cohort study that followed participants from pregnancy until 4 years after birth. At 21 weeks’ gestation and when the child was 4 years old, mothers completed questionnaires to assess state anxiety (State-Trait Anxiety Inventory) and general anxiety (Symptom Checklist-90 anxiety subscale). At age 4 years, mothers reported mindful parenting (Interpersonal Mindfulness in Parenting Scale) and child behavioral/emotional problems (Child Behavior Checklist).

Results

Maternal state anxiety during pregnancy was positively associated with child internalizing problems and negatively with mindful parenting. Maternal general anxiety during pregnancy was related with more child internalizing and externalizing problems but not with mindful parenting. The association between maternal state anxiety during pregnancy and child internalizing problems was sequentially mediated via concurrent maternal general anxiety and mindful parenting.

Conclusions

These findings suggest that maternal anxiety during pregnancy continues into early childhood and, because of this, it subsequently affects child internalizing behavior via poor mindful parenting. Replication studies are needed before developing interventions for tackling maternal anxiety during pregnancy and promoting mindful parenting.
Rehabilitative compensatory mechanism of hierarchical subnetworks in major depressive disorder: A longitudinal study across multi-sites
Authors: Wang Xinyi , Qin Jiaolong , Zhu Jinlong , Bi Kun , Zhang Siqi , Yan Rui , Zhao Peng , Yao Zhijian , Lu Qing
Published: February 2019

Background:

Brain structural connectome comprise of a minority of efficiently interconnected rich club nodes that are regarded as ‘high-order regions’. The remission of major depressive disorder (MDD) in response to selective serotonin reuptake inhibitor (SSRI) treatment could be investigated by the hierarchical structural connectomes’ alterations of subnetworks.

Methods:

Fifty-five MDD patients who achieved remission underwent diffusion tensors imaging (DTI) scanning from 3 cohorts before and after 8-weeks antidepressant treatment. Five hierarchical subnetworks namely, rich, local, feeder, rich-feeder and feeder-local, were constructed according to the different combinations of connections and nodes as defined by rich club architecture. The critical treatment-related subnetwork pattern was explored by multivariate pattern analysis with support vector machine to differ the pre-/post-treatment patients. Then, relationships between graph metrics of discriminative subnetworks/ nodes and clinical variables were further explored.

Results:

The feeder-local subnetwork presented the most discriminative power in differing pre-/post- treatment patients, while the rich-feeder subnetwork had the highest discriminative power when comparing pre-treatment patients and controls. Furthermore, based on the feeder connection, which indicates the information transmission between the core and non-core architectures of brain networks, its topological measures were found to be significantly correlated with the reduction rate of 17-item Hamilton Rating Scale for Depression.

Conclusion:

Although pathological lesion on MDD relied on abnormal core organization, disease remission was association with the compensation from non-core organization. These results suggested that the dysfunctions arising from hierarchical subnetworks are compensated by increased information interactions between core brain regions and functionally diverse regions.