bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core–Shell Materials
Authors: Masoumifard Nima , Guillet‐Nicolas Rémy , Kleitz Freddy 
Published: February 2018

AbstractThe term “engineered zeolitic materials” refers to a class of materials with a rationally designed pore system and active‐sites distribution. They are primarily made of crystalline microporous zeolites as the main building blocks, which can be accompanied by other secondary components to form composite materials. These materials are of potential importance in many industrial fields like catalysis or selective adsorption. Herein, critical aspects related to the synthesis and modification of such materials are discussed. The first section provides a short introduction on classical zeolite structures and properties, and their conventional synthesis methods. Then, the motivating rationale behind the growing demand for structural alteration of these zeolitic materials is discussed, with an emphasis on the ongoing struggles regarding mass‐transfer issues. The state‐of‐the‐art techniques that are currently available for overcoming these hurdles are reviewed. Following this, the focus is set on core–shell composites as one of the promising pathways toward the creation of a new generation of highly versatile and efficient engineered zeolitic substances. The synthesis approaches developed thus far to make zeolitic core–shell materials and their analogues, yolk–shell, and hollow materials, are also examined and summarized. Finally, the last section concisely reviews the performance of novel core–shell, yolk–shell, and hollow zeolitic materials for some important industrial applications.
2D GeP: An Unexploited Low‐Symmetry Semiconductor with Strong In‐Plane Anisotropy
Authors: Li Liang , Wang Weike , Gong Penglai , Zhu Xiangde , Deng Bei , Shi Xingqiang , Gao Guoying , Li Huiqiao , Zhai Tianyou 
Published: February 2018

AbstractGermanium phosphide (GeP), a new member of the Group IV–Group V compounds, is introduced into the fast growing 2D family with experimental and theoretical demonstration of strong anisotropic physical properties. The indirect band gap of GeP can be drastically tuned from 1.68 eV for monolayer to 0.51 eV for bulk, with highly anisotropic dispersions of band structures. Thin GeP shows strong anisotropy of phonon vibrations. Moreover, photodetectors based on GeP flakes show highly anisotropic behavior with anisotropic factors of 1.52 and 1.83 for conductance and photoresponsivity, respectively. This work lays the foundation and ignites future research interests in Group IV–Group V compound 2D materials.
Enhanced Conductivity for Carbon Nanotube Based Materials through Supramolecular Hierarchical Self‐Assembly
Authors: Zelada‐Guillén Gustavo A. , Escárcega‐Bobadilla Martha V. , Wegrzyn Marcin , Giménez Enrique , Maier Gerhard , Kleij Arjan W. 
Published: February 2018

AbstractThe currently limited comprehension of hierarchical control over out‐of‐equilibrium (dynamic) self‐assembly processes in nanoscience and nanotechnology has limited the exploitation of multicomponent systems in the design of new nanostructured functional materials. In this study's contribution, molecular building blocks with tailored nanoscale anisotropic supramolecular self‐assembly behavior enable the creation of mesoscale percolation networks of multiwalled carbon nanotubes through collinear interconnections at the microscale. This strategy affords polymeric composites with tunable properties at the macroscale, where the organization mechanism is regulated by dynamic self‐assembly at 4 hierarchical levels of auto‐organization. Such multilevel self‐assembly system reduces up to eightfolds the nanotube concentration required for percolation and enhances conductivity up to 6 orders of magnitude against blanks, thus yielding anisotropically semiconducting and conducting materials. The approach is based on casting‐from‐solution, thus simplifying preparative steps when compared to state‐of‐the‐art electron carrier counterparts such as single‐walled carbon nanotube‐, graphene‐, or indium‐tin‐oxide‐based technologies. Finally, promising material transparency levels can be reached across the visible and near‐infrared regimes for compositions above the percolation threshold, which provides new opportunities beyond the current spectral restrictions in commercial transparent conductors.
Bistetracene Thin Film Polymorphic Control to Unravel the Effect of Molecular Packing on Charge Transport
Authors: Burnett Edmund K. , Ly Jack , Niazi Muhammad R. , Zhang Lei , McCuskey Samantha R. , Amassian Aram , Smilgies Detlef‐M. , Mannsfeld Stefan C. B. , Briseno Alejandro L. 
Published: February 2018

AbstractPolymorphism, the ability for a given material to adopt multiple crystalline packing states, is a powerful approach for investigating how changes in molecular packing influence charge transport within organic semiconductors. In this study, a new “thin film” polymorph of the high‐performance, p‐type small molecule N‐octyldiisopropylsilyl acetylene bistetracene (BT) is isolated and characterized. Structural changes in the BT films are monitored using static and in situ grazing‐incidence X‐ray diffraction. The diffraction data, combined with simulation and crystallographic refinement calculations, show the molecular packing of the “thin film” polymorph transforms from a slipped 1D π‐stacking motif to a highly oriented and crystalline film upon solvent vapor annealing with a 2D brick‐layer π‐stacking arrangement, similar to the so‐called “bulk” structure observed in single crystals. Charge transport is characterized as a function of vapor annealing, grain orientation, and temperature. Demonstrating that mobility increases by three orders of magnitude upon solvent vapor annealing and displays a differing temperature‐dependent mobility behavior.
Tunable Charge Transport in Hybrid Superlattices of Indium Tin Oxide Nanocrystals and Metal Phthalocyanines—Toward Sensing Applications
Authors: Samadi Khoshkhoo Mahdi , Joseph Yvonne , Maiti Santanu , Schreiber Frank , Chassé Thomas , Scheele Marcus 
Published: February 2018

AbstractMacroscopic superlattices of tin‐doped indium oxide (ITO) nanocrystals (NCs) are prepared by self‐assembly at the air/liquid interface followed by simultaneous ligand exchange with the organic semiconductors M‐4,4′,4″,4″′‐tetraaminophthalocyanine (M4APc, M = Cu, Co, Fe, Ni, Zn). Transport measurements, focusing on the effect of the metal center of the ligand, reveal a ligand‐dependent increase in electrical conductance by six to nine orders of magnitude, suggesting that M4APc provides efficient electronic coupling for neighboring ITO NCs. The resulting I–V characteristics as well as the temperature dependence (7–300 K) of the zero‐voltage conductance indicates that at low temperatures, transport across the arrays occurs via a sequence of inelastic cotunneling events, each involving ≈3 ITO NCs. At higher temperatures, a crossover to 3D Mott‐variable range hopping mechanism is observed. Finally, the vapor sensitivity of chemiresistors is investigated made from ITO NCs coupled via Cu‐ and Zn4APc by dosing the sensors with 4‐methyl‐2‐pentanone (4M2P), toluene, 1‐propanol, and water in the concentration range of 100–5000 ppm at 0% relative humidity. The nanocrystal superlattices respond with an increase in resistance to these analytes with the highest sensitivity to 4M2P.
Earth‐Abundant Silicon for Facilitating Water Oxidation over Iron‐Based Perovskite Electrocatalyst
Authors: Xu Xiaomin , Chen Yubo , Zhou Wei , Zhong Yijun , Guan Daqin , Shao Zongping 
Published: February 2018

AbstractActive and affordable electrocatalysts made from Earth‐abundant elements are central to water electrolysis involving the oxygen evolution reaction (OER). While nonprecious transition metal‐based (Co, Ni, Fe) materials are extensively studied as cost‐effective, high‐performance alternatives to noble metal‐based catalysts, iron‐based catalysts with Fe acting as the single active site are rarely investigated due to their intrinsically low reactivity. Here, by taking advantage of the versatility of perovskite structure, metalloid Si, the second most abundant element in Earth's crust, is doped into an Fe‐based perovskite oxide (SrFeO3−δ), to obtain SrFe0.9Si0.1O3−δ as a highly efficient OER catalyst. Remarkably, SrFe0.9Si0.1O3−δ shows an approximately threefold growth in OER activity relative to SrFeO3−δ with a small Tafel slope of 58 mV dec−1, comparing favorably to or even exceeding many Co‐/Ni‐based perovskite catalysts. This enhancement can be ascribed to a structural transition from tetragonal to cubic symmetry upon Si‐doping, which brings about an optimized iron oxidation state, rich oxygen vacancies, and fast charge transfer that are beneficial to the OER catalysis. This work highlights the importance of how incorporating Earth‐abundant, nonprecious elements (e.g., Si) into a perovskite oxide structure can be used to create novel materials for the electrochemical water oxidation.
Monitoring Intrinsic Optical Signals in Brain Tissue with Organic Photodetectors
Authors: Rezaei‐Mazinani Shahab , Ivanov Anton I. , Proctor Christopher M. , Gkoupidenis Paschalis , Bernard Christophe , Malliaras George G. , Ismailova Esma 
Published: February 2018

AbstractStudies of the living tissue via optical means are able to monitor biological activities such as metabolism, gene expression, and variations in ionic concentration. Organic optoelectronic devices have numerous advantages over traditional inorganic technologies, yet limited examples of their capabilities exist in biomedical applications. An organic photodetector (OPD) with a simple structure acts as a highly sensitive optical sensor for detecting intrinsic optical signals of a living brain tissue. The signals are related to cell volume variations and are essential in detecting biological events, such as metabolism and hypoxia. This work demonstrates for the first time the capability of OPDs to assess biooptical events in neuroscience. Their simple fabrication and the capability for selective absorption of an optical event via tunable chemistry pave the way for their integration in biomedical prostheses with broad applications in bioelectronics.
Prenatal stress exposure and early childhood BMI: Exploring associations in a New Zealand context
Authors: Farewell Charlotte V. , Thayer Zaneta M. , Tracer David P. , Morton Susan 
Published: February 2018

AbstractObjectivesThe primary purpose of this study was to (i) examine associations between prenatal objective vulnerability and subjective stress, and (ii) investigate the relationships between prenatal vulnerability and subjective stress and early childhood BMI at 24‐ and 54‐ months of age after controlling for covariates.MethodsThe Growing Up in New Zealand (GUiNZ) longitudinal study provided information on 5839 pregnant women and their children to assess the study objectives. Vulnerability, operationalized by nine objective‐risk factors, and subjective stress, operationalized by the Perceived Stress Scale, were independently investigated. Hierarchical linear regression models were conducted to analyze the associations between both prenatal measures and childhood BMI at 24‐ and 54‐ months of age.ResultsCorrelations between subjective stress and objective vulnerability were low but significant (r = .28, P < .01). Exposure to one additional risk factor during pregnancy was significantly associated with a .11 increase in BMI z‐score at 24‐months (P < .01) and a .15 increase in BMI z‐score at 54‐months (P < .01), after controlling for covariates including maternal prepregnancy BMI. Subjective prenatal stress was not significantly associated with either child BMI outcome.ConclusionsVulnerability and subjective stress were minimally correlated in this sample. Vulnerability, but not subjective stress, was associated with childhood BMI at 24‐ and 54‐ months of age. This study informs our understanding of how risk exposures and stress responses early in life impacts offspring obesity risk, and it may help identify strategies that decrease early life predisposition to adult disease.
Monitoring olfactory function in chronic rhinosinusitis and the effect of disease duration on outcome
Authors: Whitcroft Katherine L. , Cuevas Mandy , Andrews Peter , Hummel Thomas 
Published: February 2018

BackgroundOur primary aim in this study was to determine which of the “Sniffin’ Sticks” subtest components (threshold, discrimination, or identification) best reflect overall change in olfactory function during treatment for chronic rhinosinusitis (CRS). Our secondary aim was to determine whether duration of CRS affects olfactory outcomes after treatment.MethodsA retrospective cohort study was performed. Sniffin’ Sticks test scores from patients medically treated for CRS at our center from 1999 to 2016 were analyzed. Only patients with 2 test scores available were included.ResultsResults from 408 patients were included (mean age, 56 years; male:female ratio, 217:191). There was a statistically significant improvement in threshold (T), discrimination (D), and identification (I) scores as well as the composite “TDI” score between the two testing sessions. Controlling for age, there was a significantly greater improvement in composite TDI score in patients with CRS of ≤24 months duration. As expected, we found statistically significant correlations between change in overall composite TDI score and change in threshhold, discrimination, and identification, between sessions. Of the individual subcomponents, change in discrimination correlated best with change in composite TDI score (r = 0.82, p < 0.0001). This relationship was maintained irrespective of duration of CRS.ConclusionsIn patients with CRS, odor discrimination appears to best reflect overall changes in olfactory function, as determined using the composite TDI score. Furthermore, olfactory outcomes are better when treatment is started sooner.
Access to Enantioenriched Organosilanes from Enals and β‐Silyl Enones: Carbene Organocatalysis
Authors: Zhang Yuxia , Huang Jie , Guo Yingying , Li Lin , Fu Zhenqian , Huang Wei 
Published: February 2018

AbstractHerein, an efficient route to enantioenriched organosilanes, containing two consecutive stereogenic centers, from enals and β‐silyl enones under carbene organocatalysis is described. Under mild reaction conditions, this transition‐metal‐free strategy exhibits a broad substrate scope, and excellent diastereo‐ and enantioselectivity.
Utilization of a Fluorescent Dye Molecule as a Proton and Electron Reservoir
Authors: Kieffer Ian A. , Allen Robert J. , Fernandez Jordan L. , Deobald Jackson L. , Thompson Brena L. , Wimpenny Jacob D. , Heiden Zachariah M. 
Published: February 2018

AbstractFluorescent dyes have been widely utilized as chemical sensors and in photodynamic therapy, but exploitation of their redox‐active nature in chemical reactions has remained mostly unexplored. This report describes the isolation of a 4,4‐difluoro‐4‐bora‐3a,4a‐diaza‐s‐indacene (BODIPY)‐based radical. The redox‐active nature of the BODIPY compound can be utilized in combination with a guanidine center, the basicity of which can be manipulated by greater than 14 pKa units, to promote the conversion of protons and electrons into H‐atoms for transfer to substrate molecules.
Effect of the comonomer content on the solid‐state mechanical and viscoelastic properties of poly(propylene‐co‐1‐butene) films
Authors: Kasgoz Alper , Tamer Murat , Kocyigit Ciler , Durmus Ali 
Published: February 2018

ABSTRACTIn this study, we quantified the thermal and solid‐state mechanical and viscoelastic properties of isotactic polypropylene (i‐PP) homopolymer and poly(propylene‐1‐butene) copolymer films having a 1‐butene ratio of 8, 12, and 14 wt %, depending on the comonomer content. The uniaxial tensile creep and stress‐relaxation behaviors of the samples were studied in a dynamic mechanical analyzer at different temperatures. The creep behaviors of the samples were modeled with the four‐element Burger equation, and the long‐term creep strains were predicted with the time–temperature superposition method. The short‐term mechanical properties of the samples were also determined with tensile and impact testing at room temperature. We found that the Young's modulus and ultimate strength values of the samples decreased with increasing amount of 1‐butene in the copolymer structure. On the other hand, the strain at break and impact strength values of the samples improved with increasing amount of 1‐butene. Creep analysis showed that i‐PP exhibited a relatively lower creep strain than the poly(propylene‐co‐1‐butene)s at 30 °C. However, interestingly, we discovered that the temperature increase resulted in different effects on the creep behaviors. We also found that short‐chain branching improved the creep resistance of polypropylene at relatively high temperatures. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46350.
Synergistic effect between aluminum hypophosphite and a new intumescent flame retardant system in poly(lactic acid)
Authors: Liu Gousheng , Gao Shang 
Published: February 2018

ABSTRACTA hyperbranched charring agent (CT) was synthesized by triglycidyl isocyanurate and diethylenetriamine in water, and a new intumescent flame retardant (IFR) system was formed by ammonium polyphosphate (APP) and CT. The different formula and synergistic system between IFR and aluminum hypophosphite (AHP) have been studied through limit oxygen index (LOI), UL‐94, cone calorimetry test and TGA. It was found that the LOI for poly(lactic acid) (PLA) with 30 APP/CT (4:1) and 20 wt % IFR/AHP (3:1) were 41.2% and 43.5%, respectively, and the both could achieve UL‐94V‐0 rating with no melt dripping. The heat release rate (HRR), maximum HRR value and average mass loss rate of PLA could be dramatically decreased by combination of IFR and AHP while the thermal stability was greatly enhanced. The study of morphology and structure of char illustrated that more intumescent and compact char layer with good intensity was formed during the degradation of IFR/AHP, which resulting to better flame retardancy and anti‐dripping than IFR or AHP alone. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46359.
Flow‐induced crystallization of polylactide stereocomplex under pressure
Authors: Song Ying‐Nan , Zhao Qing‐Xiang , Yang Shu‐Gui , Ru Jia‐Feng , Lin Jian‐Mei , Xu Jia‐Zhuang , Lei Jun , Li Zhong‐Ming 
Published: February 2018

ABSTRACTAlthough shear and pressure fields always coexist in practical polymer processing, their combined influence on the crystallization behavior of polylactide stereocomplex (SC) is ambiguous due to the limit of experiment device. In that case, a homemade device was employed to prepare samples under the coexistence of shear and pressure and explore the crystallization behavior of SC. Differential scanning calorimetry and synchrotron radiation were used to investigate the combined effect of shear flow and pressure on SC crystallization. The results show that shear flow was helpful for SC formation. Shear flow promoted the phase mixing of the polymer blends and improved the nucleation efficiency of SC. Pressure had a negative effect on SC formation because of the decrease in free volume. Regard to polylactide homogeneous (HC), pressure played a positive role on HC formation. Pressure suppressed the formation of SC network which could impede HC generation. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46378.
The Macrofungi Collection Consortium
Authors: Thiers Barbara M. , Halling Roy E. 
Published: February 2018

Premise of the StudyThe Macrofungi Collection Consortium (MaCC) is a digitization project funded by the National Science Foundation's Advancing Digitization of Biodiversity Collections program. The main scientific objective of the MaCC project was to provide baseline data for determining the extent and distribution of macrofungal diversity.Methods and ResultsBetween 2012 and 2017, 39 participating institutions digitized approximately 1,250,000 specimens of macrofungi from U.S. herbaria. These newly digitized data, combined with existing data and contributions from the Microfungi Collections Consortium, have created a database of approximately 3.4 million specimen records that are shared online through MyCoPortal, a Symbiota‐based data portal. In addition to the digitized herbarium specimen data, MyCoPortal also contains descriptions, illustrations, and observational records.DiscussionThe database of digitized specimen data created through this project is a resource for both amateur and professional mycologists. The data provided through MyCoPortal will provide a foundation for a comprehensive Mycoflora of North America. Such a project is now under development as a collaboration between the professional and amateur mycological communities, with the goal of documenting the macrofungi of North America with gene sequences as well as phenotypic descriptions and images.
Future questions in insect chitin biology: A microreview
Authors: Muthukrishnan Subbaratnam , Arakane Yasuyuki , Yang Qing , Zhang Chuan‐Xi , Zhang Jianzhen , Zhang Wenqing , Moussian Bernard 
Published: February 2018

AbstractThis microreview stems from the Second Symposium on Insect Molecular Toxicology and Chitin Metabolism held at Shanxi University in Taiyuan, China (June 27 to 30, 2017) at the institute for Applied Biology headed by Professor Enbo Ma and Professor Jianzhen Zhang.
The geophysical truth about the ‘Gold Train’ in Walbrzych, Poland
Authors: Madej Janusz , Łój Monika , Porzucek Sławomir , Jaśkowski Wojciech , Karczewski Jerzy , Tomecka‐Suchoń Sylwia 
Published: February 2018

AbstractThe paper presents the results of geophysical research conducted in the region where the so called ‘Gold Train’ was believed to be located. The surveyed site was located in Wałbrzych, at the 65th kilometre of the railway connecting Wrocław and Wałbrzych. The aim of the research was to verify the legend of the existence of the so called ‘Gold Train’ that was supposed to be located in the tunnel. The ‘Gold Train’ was believed to contain Wrocław's treasures. Three geophysical methods were used. Microgravimetric and GPR (ground‐penetrating radar) methods were applied to locate the void (tunnel), while the search for the train (a metal object) was conducted with the use of a magnetic method. Detailed geodetic measurements were used, including, among others, laser scanning. Due to complex terrain and geological structure, the negative results of the microgravimetric research was conclusive only in respect of one of the profiles. Due to high attenuation of electromagnetic wave by a shallow geological structure the scope of the GPR method was limited, however it was sufficient to confirm that such a tunnel does not exist. Despite difficulties related to electric lines in the researched area, conclusive results were obtained using the magnetic method. No magnetic anomaly with a shape or amplitude indicative of a steel train was identified.