bluuebunny/crossref_metadata_2025 huggingface dataset:
Biogenic Supported Lipid Bilayers from Nanosized Extracellular Vesicles
Authors: Montis Costanza , Busatto Sara , Valle Francesco , Zendrini Andrea , Salvatore Annalisa , Gerelli Yuri , Berti Debora , Bergese Paolo
Published: February 2018

Fabrication of synthetic surfaces that reproduce structure and function of biological membranes is an open challenge. This work reports the first example of supported lipid bilayers obtained from extracellular vesicles (EVSLBs). EVSLBs harness and pattern in two dimensions key properties of extracellular vesicle (EV) membranes, which present intermediate complexity between synthetic mimics and natural membranes and innate link to phenotype and function of the originating cells. Silica‐supported EVSLBs are formed from nanosized EVs—separated from culture media of prostate cancer model TRAMP‐C2 murine cells—following a characteristic crowding‐fusion pathway. They display peculiar properties at different length scales, such as 2.5 nm roughness, lipid‐raft‐like domains, and cushioned patches (with the cushion filled with the native EV biomolecular cargo), which preserve the native EV membrane orientation with the proto‐oncogene tyrosine‐protein kinase Src (c‐Src) accessible to antibody recognition.
Talking to Cells: Semiconductor Nanomaterials at the Cellular Interface
Authors: Rotenberg Menahem Y. , Tian Bozhi
Published: February 2018

The interface of biological components with semiconductors is a growing field with numerous applications. For example, the interfaces can be used to sense and modulate the electrical activity of single cells and tissues. From the materials point of view, silicon (Si) is the ideal option for such studies due to its controlled chemical synthesis, scalable lithography for functional devices, excellent electronic and optical properties, biocompatibility, and biodegradability. Recent advances in this area are pushing the biointerfaces from the tissue and organ level to the single cell and subcellular regimes. In this progress report, some fundamental studies are described focusing on miniaturizing the bioelectric and biomechanical interfaces. Additionally, many highlighted examples involve freestanding Si‐based nanoscale systems, in addition to substrate‐bound structures or devices; the former offers new promise for basic research and clinical application. In this report, recent developments in the interfacing of neuronal and cardiac cells and their networks are described. Moreover, a brief discussion of the incorporation of semiconductor nanostructures for interfacing nonexcitable cells in applications such as probing intracellular force dynamics and drug delivery is included. Finally, several directions for future exploration are suggested.
Laser‐Induced Surface Modification of Contact Lenses
Authors: Alqurashi Yousef , Bajgrowicz‐Cieslak Magdalena , Hassan Muhammad Umair , Yetisen Ali K. , Butt Haider
Published: February 2018

The authors report on the laser‐induced modification of surface properties of contact lenses. Selective areas of the surface of commercial silicon‐hydrogel contact lenses are patterned in array formats using different powers of the CO2 laser. 1D arrays of different groove densities, channels, and 2D intersecting architecture are fabricated. Contact angle measurements are carried out to measure the surface hydrophilicity, and extent of hydration is linked with the surface profile properties and the space gap between the fabricated patterns, which are controlled by the beam exposure time, beam power, and scan speed. Laser treatment of contact lenses results in improved hydration proportional to the density of laser ablated segments on the surface. The hydration time of water droplets on different lens surfaces is also recorded – all 2D patterned lenses show faster hydration as water quickly diffused into the bulk of the lens due to the extended interfacial area between the contact lens and the water droplet as a consequence of larger areal modification in 2D as compared with 1D patterns. The best wettability properties are obtained with 0.3 mm space gap, 9 W power, and 200 mm s−1 scan speed. Optical microscopy is used to image the 3D surface profiles of the modified lenses and the depth of the patterns and is correlated with the experimental observations. The maximum depth of 40 µm is observed with 0.3 mm space gap, 9 W, and 200 mm s−1 scan speed. Optical transmittance of broadband white light is measured to assess the surface treatment effects on the contact lenses. A large exposure and dense patterning of contact lens result in decreased (down to a minimum of 45%) in the light transmittance, which dictates the practical usability of such patterning. Surface treatment of contact lenses can be utilized to deposit stable conducting connection for on‐lens‐LEDs, displays, and communication antennas as well as for stabilizing biosensing materials and drug dispensing applications.
Characterization of Surface and Structure of In Situ Doped Sol‐Gel‐Derived Silicon Carbide
Authors: Kettner Olivia , Šimić Sanja , Kunert Birgit , Schennach Robert , Resel Roland , Grießer Thomas , Friedel Bettina
Published: February 2018

Silicon carbide (SiC), is an artificial semiconductor used for high‐power transistors and blue LEDs, for its extraordinary properties. SiC will be attractive for more applications, but large‐scale or large‐surface area fabrication, with control over defects and surface is challenging. Sol‐gel based techniques are an affordable alternative toward such requirements. This report describes two types of microcrystalline SiC derived after carbothermal reduction from sol‐gel‐based precursors, one with nitrogen added, the other aluminum. Characterization of their bulk, structure, and surface shows that incorporation of dopants affects the formation of polytypes and surface chemistry. Nitrogen leads exclusively to cubic SiC, exhibiting a native oxide surface. Presence of aluminum instead promotes growth of hexagonal polytypes and induces self‐passivation of the crystallites’ surface during growth. This is established by hydrogenation of silicon bonds and formation of a protecting aluminum carbonate species. XPS provides support for the suggested mechanism. This passivation is achieved in only one step, solely by aluminum in the precursor. Hence, it is shown that growth, doping and passivation of SiC can be performed as “one‐pot synthesis”. Material without insulating oxide and a limited number of defects is highly valuable for applications involving surface‐sensitive charge‐transfer reactions, therefore the potential of this method is significant.
Protein‐Directed Metal Oxide Nanoflakes with Tandem Enzyme‐Like Characteristics: Colorimetric Glucose Sensing Based on One‐Pot Enzyme‐Free Cascade Catalysis
Authors: Han Lei , Zhang Haijiao , Chen Daoyuan , Li Feng
Published: February 2018

It is difficult and significant to realize the aim of “one‐pot” and “nonenzyme” for traditional colorimetric detection of blood glucose. The synthesis of nanomaterials with 2D morphology is also a challenge for the bovine serum albumin (BSA)‐directed method. Here, the BSA‐directed synthesis avenue for metal oxide with 2D nanomorphology is developed. MnO2 nanoflakes (NFs) with controllable morphology can be obtained by changing the synthesis conditions. Fortunately, not only is the glucose oxidase (GOx)‐like nanozyme (MnO2 NFs) discovered, but MnO2 NFs also show dual enzyme activities (GOx‐like activity and peroxidase‐like activity) in similar pH range. That is to say, a “tandem nanozyme” (nanomaterial with tandem enzyme‐like characteristics) is presented here. Further, the one‐pot nonenzymatic strategy is proposed for the colorimetric detection of glucose, where the oxidation of glucose and the colorimetric detection of H2O2 are simultaneously conducted under the catalysis of the single nanozyme (MnO2 NFs). The method shows high sensitivity, low limit of detection, and short detection time, due to the proximity effect and in situ reaction. The as‐synthesized 2D tandem nanozyme expands the species of nanozymes, and the proposed strategy breaks traditional colorimetric detection process, accomplishing the purposes of “one‐pot” and “nonenzyme” in the true sense.
Synthesis of Engineered Zeolitic Materials: From Classical Zeolites to Hierarchical Core–Shell Materials
Authors: Masoumifard Nima , Guillet‐Nicolas Rémy , Kleitz Freddy
Published: February 2018

The 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

Germanium 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

The 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

Polymorphism, 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

Macroscopic 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

Active 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

Studies 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.
New algorithm for the flexibility index problem of quadratic systems
Authors: Jiang Hao , Chen Bingzhen , Grossmann Ignacio E.
Published: February 2018

A new flexibility index algorithm for systems under uncertainty and represented by quadratic inequalities is presented. Inspired by the outer‐approximation algorithm for convex mixed‐integer nonlinear programming, a similar iterative strategy is developed. The subproblem, which is a nonlinear program, is constructed by fixing the vertex directions since this class of systems is proved to have a vertex solution if the entries on the diagonal of the Hessian matrix are non‐negative. By overestimating the nonlinear constraints, a linear min–max problem is formulated. By dualizing the inner maximization problem, and introducing new variables and constraints, the master problem is reformulated as a mixed‐integer linear program. By iteratively solving the subproblem and master problem, the algorithm can be guaranteed to converge to the flexibility index. Numerical examples including a heat exchanger network, a process network, and a unit commitment problem are presented to illustrate the computational efficiency of the algorithm. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2486–2499, 2018
Application of inline imaging for monitoring crystallization process in a continuous oscillatory baffled crystallizer
Authors: Kacker Rohit , Maaß Sebastian , Emmerich Jörn , Kramer Herman
Published: February 2018

In this study, an in situ imaging system has been analysed to characterize the crystal size, the shape and the number of particles during a continuous crystallization process in a Continuous Oscillatory Baffled Crystallizer (COBC). Two image analysis approaches were examined for particle characterization in the suspension containing both small nuclei and larger grown crystals (nonspherical and irregular in shape). The pattern matching approach, in which the particles are approximated to be spherical, did result in an overestimation of the size. Alternatively, a segmentation‐based algorithm resulted in reliable crystal size and shape characteristics. The laser diffraction analysis in comparison to the image analysis overestimated the particle sizes due to the agglomeration of particles upon filtration and drying. The trend in the particle counts during the start of crystallization process, including nucleation, determined by the image analysis probe was comparable with the one measured by FBRM, highlighting the potential of in situ imaging for process monitoring. © 2018 American Institute of Chemical Engineers AIChE J, 64: 2450–2461, 2018
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

Objectives

The 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.

Methods

The 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.

Results

Correlations 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.

Conclusions

Vulnerability 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

Background

Our 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.

Methods

A 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.

Results

Results 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.

Conclusions

In 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

Herein, 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

Fluorescent 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

In 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

A 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

Although 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 Study

The 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 Results

Between 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.

Discussion

The 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

This 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

The 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.
Valence‐Tuned Lithium Titanate Nanopowder for High‐Rate Electrochemical Energy Storage
Authors: Widmaier Mathias , Pfeifer Kristina , Bommer Lars , Presser Volker
Published: February 2018

In recent years, numerous studies have explored ways to overcome the low intrinsic electrical conductivity of lithium titanate (Li4Ti5O12, LTO) for energy storage with lithium‐ion batteries. These approaches almost exclusively considered element doping and elaborate LTO‐carbon nanocomposites, whereas simple adjustment of the defect concentration remains largely unexplored. In our study, we tune the Ti3+/Ti4+ concentration of a commercial LTO nanopowder through oxygen vacancy formation during thermal annealing in hydrogen atmosphere. We investigate the impact of the treatment on material properties like energy band structure, electrical conductivity, crystallinity, phase distribution, surface chemistry, and particle morphology, and correlate these parameters to the electrochemical performance. At optimum treatment conditions, the intrinsic electrical conductivity can be greatly improved, while circumventing LTO phase transformations or amorphization. This enables the reduction of the carbon concentration to 5 mass%, while yielding a high electrode capacity of about 70 mAh/g (82 mAh/g based on active mass) at ultrahigh C‐rates of 100C. When combined with an activated carbon/lithium manganese oxide composite cathode, an excellent energy and power performance of 70 Wh/kg and 47 kW/kg were obtained (82 Wh/kg and 55 kW/kg based on active mass), while maintaining 83 % of its energy ratings after 5000 cycles at 10C (78 % after 15000 cycles at 100C).
The effect of 7,8,4´‐trihydroxyflavone on tyrosinase activity and conformation: Spectroscopy and docking studies
Authors: Shang Chao , Zhang Yongkui , You Xue , Guo Nihong , Wang Yang , Fan Yang , Liu Wenbin
Published: February 2018

Tyrosinase is a ubiquitous enzyme that plays an essential role in the production of melanin. Effective inhibitors of tyrosinase have extensive applications in the medical, cosmetic and food industries. In this study, a combination of enzyme kinetics, ultraviolet (UV)‐visible absorption, fluorescence spectroscopic techniques and a computational simulation method was used to characterize the inhibitory mechanism of 7,8,4´‐trihydroxyflavone on tyrosinase. 7,8,4´‐Trihydroxyflavone was found to strongly inhibit the oxidation of l‐DOPA by tyrosinase with an IC50 value of 10.31 ± 0.41 μM. The inhibitory mechanism was determined to be reversible and non‐competitive with a Ki of 9.50 ± 0.40 μM. The UV absorption spectra showed that 7,8,4´‐trihydroxyflavone could chelate with copper ions and form a complex with tyrosinase. The intrinsic fluorescence of tyrosinase was quenched by 7,8,4´‐trihydroxyflavone through a static quenching mechanism. 7,8,4´‐Trihydroxyflavone was found to occupy a single binding site with a binding constant of 7.50 ± 1.20 × 104 M−1 at 298 K. The conformation of tyrosinase changed, and the microenvironment became more hydrophilic after 7,8,4´‐trihydroxyflavone binding. Thermodynamics parameters indicated that the binding was a spontaneous process and involved hydrogen bonds and van der Waals forces. The binding distance was evaluated to be 4.54 ± 0.05 nm. Docking simulation analysis further authenticated that 7,8,4´‐trihydroxyflavone could form hydrogen bonds with the residues His244 and Met280 within the tyrosinase active site. Our results will contribute to further understanding of the inhibitory mechanisms of 7,8,4´‐trihydroxyflavone against tyrosinase and will facilitate future screening for tyrosinase inhibitors.
Enhancement of malate production through engineering of the periplasmic rTCA pathway in Escherichia coli
Authors: Guo Liang , Zhang Fan , Zhang Can , Hu Guipeng , Gao Cong , Chen Xiulai , Liu Liming
Published: February 2018

The compartmentalization of enzymes into organelles is a promising strategy for limiting metabolic crosstalk and improving pathway efficiency; however, prokaryotes are unicellular organisms that lack membrane‐bound organelles. To mimic this natural compartmentalization, we present here the targeting of the reductive tricarboxylic acid (rTCA) pathway to the periplasm to enhance the production of malate. A multigene combination knockout strategy was used to construct a phosphoenolpyruvate (PEP) pool. Then, the genes encoding phosphoenolpyruvate carboxykinase and malate dehydrogenase were combinatorially overexpressed to construct a cytoplasmic rTCA pathway for malate biosynthesis; however, the efficiency of malate production was low. To further enhance malate production, the rTCA pathway was targeted to the periplasm, which led to a 100% increase in malate production to 18.8 mM. Next, dual metabolic engineering regulation was adopted to balance the cytoplasmic and periplasmic pathways, leading to an increase in malate production to 58.8 mM. The final engineered strain, GL2306, produced 193 mM malate with a yield of 0.53 mol/mol in 5 L of pH‐stat fed‐batch culture. The strategy described here paves the way for the development of metabolic engineering and synthetic biology in the microbial production of chemicals.
Biosynthesis of a ganoderic acid in Saccharomyces cerevisiae by expressing a cytochrome P450 gene from Ganoderma lucidum
Authors: Wang Wen‐Fang , Xiao Han , Zhong Jian‐Jiang
Published: February 2018

Ganoderic acid (GA), a triterpenoid from the traditional Chinese medicinal higher fungus Ganoderma lucidum, possesses antitumor and other significant pharmacological activities. Owing to the notorious difficulty and immaturity in genetic manipulation of higher fungi as well as their slow growth, biosynthesis of GAs in a heterologous host is an attractive alternative for their efficient bioproduction. In this study, using Saccharomyces cerevisiae as a host, we did a systematic screening of cytochrome P450 monooxygenase (CYP450) gene candidates from G. lucidum, which may be responsible for the GA biosynthesis from lanosterol but have not been functionally characterized. As a result, overexpression of a CYP450 gene cyp5150l8 was firstly found to produce an antitumor GA, 3‐hydroxy‐lanosta‐8, 24‐dien‐26 oic acid (HLDOA) in S. cerevisiae, as confirmed by HPLC, LC‐MS and NMR. A final titer of 14.5 mg/L of HLDOA was obtained at 120 hr of the yeast fermentation. Furthermore, our in vitro enzymatic experiments indicate that CYP5150L8 catalyzes a three‐step biotransformation of lanosterol at C‐26 to synthesize HLDOA. To our knowledge, this is the first report on the heterologous biosynthesis of GAs. The results will be helpful to the GA biosynthetic pathway elucidation and to future optimization of heterologous cell factories for GA production.
What are the green technologies for sustainable housing development? An empirical study in Ghana
Authors: Darko Amos , Chan Albert Ping Chuen , Owusu Emmanuel Kingsford
Published: February 2018

The housing industry is a major contributor to global climate change, environmental pollution, and resource depletion. The adoption of green technologies in housing development is a way to realize sustainable development goals. This research aims to identify the green technologies that are important to achieve sustainable housing development, in particular Accra, Ghana. Due to differences in climate, focusing on Accra helps validate the findings of this study. To achieve the objective, 28 green technologies were identified from a comprehensive literature review, and a questionnaire survey was done with 43 professionals with green building experience. The results indicated that application of natural ventilation, application of energy‐efficient lighting systems, optimizing building orientation and configuration, application of energy‐efficient high efficient heating, ventilation, and air‐conditioning system, and installation of water‐efficient appliances and fixtures were the five most important green technologies to achieve sustainable housing development. Furthermore, water efficiency technologies and energy efficiency technologies had the highest level of importance. The identified green technologies form a conceptual framework which can be used to guide the identification and selection of green technologies for sustainable housing development. The research findings would be useful for industry professionals responsible for decision making during the design stage of housing developments. Theoretically, this study adds to the literature by presenting one of the first studies in its kind focusing on green technologies for sustainable housing development within the Ghanaian context.
Improving the Economic Performance of Remanufacturing Systems through Flexible Design Strategies: A Case Study Based on Remanufacturing Laptop Computers for the Cambodian Market
Authors: Low Jonathan Sze Choong , Ng Yen Ting
Published: February 2018

Although numerous studies have highlighted the contributions of remanufacturing to sustainable development and the circular economy, the decision for a company to take up this strategy is riddled with uncertainties, especially when significant capital investment is involved. To improve the economic performance of a remanufacturing system in the face of uncertainties, we propose a methodological framework for flexible design of remanufacturing systems. Its application is demonstrated using a case study based on remanufacturing laptop computers for the Cambodian market. Through the case study, we show how one can explore the opportunity of setting up a remanufacturing system, study its economic feasibility and design flexible strategies to improve its economic performance in the face of uncertainties. More interestingly, we demonstrate how Monte Carlo simulation can be used to evaluate the effectiveness of different flexible design strategies in dealing with the uncertainties. Copyright © 2018 John Wiley & Sons, Ltd and ERP Environment
The prognostic value of CYP2C subfamily genes in hepatocellular carcinoma
Authors: Wang Xiangkun , Yu Tingdong , Liao Xiwen , Yang Chengkun , Han Chuangye , Zhu Guangzhi , Huang Ketuan , Yu Long , Qin Wei , Su Hao , Liu Xiaoguang , Peng Tao
Published: February 2018

Cytochrome P2C (CYP2C) subfamily members (CYP2C8, CYP2C9, CYP2C18, and CYP2C19) are known to participate in clinical drug metabolism. However, the association between CYP2C subfamily members and hepatocellular carcinoma (HCC) remains unclear. This study investigated the prognostic value of CYP2C subfamily gene expression levels with HCC prognosis. Data of 360 HCC patients in The Cancer Genome Atlas database and 231 in the Gene Expression Omnibus database were analyzed. Kaplan–Meier analysis and a Cox regression model were used to ascertain overall survival and recurrence‐free survival, and to calculate median survival time using hazard ratios (HR) and 95% confidence intervals (CI). In TCGA database, low expression of CYP2C8, CYP2C9, and CYP2C19 in tumor tissue was associated with a short median survival time (all crude P = 0.001, adjusted P = 0.004, P = 0.047, and P = 0.020, respectively). In TCGA database, joint effects analysis of the combinations of CYP2C8 and CYP2C9, CYP2C8 and CYP2C19, and CYP2C9 and CYP2C19 revealed that high expression of two genes (group 4; group IV, group d) was associated with a reduced risk of death as compared to low expression (group 1, group I, and group a) (adjusted P = 0.005, P = 0.013, and P = 0.016, respectively). In TCGA database, joint effects analysis of CYP2C8, CYP2C9, and CYP2C19 showed that the risk of death from HCC was lower for groups C and D than for group A (adjusted P = 0.012 and P = 0.008, respectively). CYP2C8, CYP2C9, and CYP2C19 gene expression levels are potential prognostic markers of HCC following hepatectomy.
PARP inhibitor olaparib sensitizes cholangiocarcinoma cells to radiation
Authors: Mao Yize , Huang Xin , Shuang Zeyu , Lin Guohe , Wang Jun , Duan Fangting , Chen Jianlin , Li Shengping
Published: February 2018

Cholangiocarcinoma (CCA) is a highly malignant tumor with resistance to radiotherapy alone. Olaparib, a highly potent poly(ADP‐ribose) polymerase (PARP) inhibitor, has been shown to sensitize many types of tumor to radiotherapy. However, the effect of olaparib, either as monotherapy or as combination therapy with radiotherapy, on CCA is not known, and our study aimed to explore this. To assess radiosensitization in three CCA cell lines (QBC939, HuH28 and TFK‐1), viability and clonogenic assays were conducted. The absorbed radiation doses were 0 Gy, 2 Gy, 4 Gy, and 6 Gy; olaparib concentrations were 0 nmol/L, 1 nmol/L, 10 nmol/L, 100 nmol/L, 1000 nmol/L, 2500 nmol/L, 5000 nmol/L and 10 000 nmol/L. The mechanism of olaparib radiosensitization was explored by Western blotting. Immunofluorescence staining and flow cytometry were conducted to explore DNA damage and apoptosis. The radiosensitivity of CCA cells was enhanced by olaparib, which alone had little effect on the CCA cell lines without BRCA mutations. The degree of radiosensitization increased with increasing doses of olaparib by viability and clonogenic assays in vitro. Olaparib was able to enhance the effect of radiation by inhibiting PARP1, inducing DNA lesions and apoptosis. These findings emphasize the role of olaparib in the radiosensitization of CCA cells.