bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermodynamic and Kinetic Tuning of Block Copolymer Based on Random Copolymerization for High‐Quality Sub‐6 nm Pattern Formation
Authors: Hur Yoon Hyung , Song Seung Won , Kim Jong Min , Park Woon Ik , Kim Kwang Ho , Kim YongJoo , Jung Yeon Sik 
Published: May 2018

AbstractThe precisely controllable self‐assembly phenomenon of block copolymers (BCPs) has garnered much attention because it yields well‐defined periodic nanostructures with a periodicity of 5–50 nm. However, from both thermodynamic and kinetic viewpoints, it still remains a challenge to develop a BCP material that can provide sub‐10 nm resolution, high pattern quality, fast pattern formation, and sufficient etch selectivity. To address these challenges, this study reports a BCP system containing a random‐copolymerized block (poly(2‐vinylpyridine‐co‐4‐vinylpyridne)‐b‐poly(dimethylsiloxane) (P(2VP‐co‐4VP)‐b‐PDMS)) that can provide sub‐6 nm resolution, 3σ line edge roughness of 0.89 nm, sub‐1‐min assembly time, and a high etch selectivity over 10. Calculation of the Flory–Huggins interaction parameter (χ) based on Leibler's mean‐field theory and small‐angle X‐ray scattering measurement data confirms the gradual tunability of χ with the controlled addition of 4VP fraction in the P(2VP‐co‐4VP) block. While guaranteeing kinetically fast self‐assembly within one minute using microwave annealing, the best pattern quality resulting from the thermodynamic suppression of line edge fluctuation is achieved with a 4VP weight fraction of 33% in the random‐copolymerized block. This approach enables systematical control of sub‐6 nm scale BCP self‐assembly and will provide a practical patterning solution for diverse nanostructures and devices.
Nanoporous Metallic Networks: Fabrication, Optical Properties, and Applications
Authors: Ron Racheli , Haleva Emir , Salomon Adi 
Published: May 2018

AbstractNanoporous metallic networks are a group of porous materials made of solid metals with suboptical wavelength sizes of both particles and voids. They are characterized by unique optical properties, as well as high surface area and permeability of guest materials. As such, they attract a great focus as novel materials for photonics, catalysis, sensing, and renewable energy. Their properties together with the ability for scaling‐up evoke an increased interest also in the industrial field. Here, fabrication techniques of large‐scale metallic networks are discussed, and their interesting optical properties as well as their applications are considered. In particular, the focus is on disordered systems, which may facilitate the fabrication technique, yet, endow the three‐dimensional (3D) network with distinct optical properties. These metallic networks bridge the nanoworld into the macroscopic world, and therefore pave the way to the fabrication of innovative materials with unique optoelectronic properties.
Artificial Rod and Cone Photoreceptors with Human‐Like Spectral Sensitivities
Authors: Park Byeongho , Yang Heehong , Ha Tai Hwan , Park Hyun Seo , Oh Seung Ja , Ryu Yong‐Sang , Cho Youngho , Kim Hyo‐Suk , Oh Juyeong , Lee Dong Kyu , Kim Chulki , Lee Taikjin , Seo Minah , Choi Jaebin , Jhon Young Min , Woo Deok Ha , Lee Seok , Kim Seok Hwan , Lee Hyuk‐Jae , Jun Seong Chan , Song Hyun Seok , Park Tai Hyun , Kim Jae Hun 
Published: May 2018

AbstractPhotosensitive materials contain biologically engineered elements and are constructed using delicate techniques, with special attention devoted to efficiency, stability, and biocompatibility. However, to date, no photosensitive material has been developed to replace damaged visual‐systems to detect light and transmit the signal to a neuron in the human body. In the current study, artificial nanovesicle‐based photosensitive materials are observed to possess the characteristics of photoreceptors similar to the human eye. The materials exhibit considerably effective spectral characteristics according to each pigment. Four photoreceptors originating from the human eye with color‐distinguishability are produced in human embryonic kidney (HEK)‐293 cells and partially purified in the form of nanovesicles. Under various wavelengths of visible light, electrochemical measurements are performed to analyze the physiological behavior and kinetics of the photoreceptors, with graphene, performing as an electrode, playing an important role in the lipid bilayer deposition and oxygen reduction processes. Four nanovesicles with different photoreceptors, namely, rhodopsin (Rho), short‐, medium‐, and longwave sensitive opsin 1 (1SW, 1MW, 1LW), show remarkable color‐dependent characteristics, consistent with those of natural human retina. With four different light‐emitting diodes for functional verification, the photoreceptors embedded in nanovesicles show remarkably specific color sensitivity. This study demonstrates the potential applications of light‐activated platforms in biological optoelectronic industries.
Nanosheets of Nonlayered Aluminum Metal–Organic Frameworks through a Surfactant‐Assisted Method
Authors: Pustovarenko Alexey , Goesten Maarten G. , Sachdeva Sumit , Shan Meixia , Amghouz Zakariae , Belmabkhout Youssef , Dikhtiarenko Alla , Rodenas Tania , Keskin Damla , Voets Ilja K. , Weckhuysen Bert M. , Eddaoudi Mohamed , de Smet Louis C. P. M. , Sudhölter Ernst J. R. , Kapteijn Freek , Seoane Beatriz , Gascon Jorge 
Published: May 2018

AbstractDuring the last decade, the synthesis and application of metal–organic framework (MOF) nanosheets has received growing interest, showing unique performances for different technological applications. Despite the potential of this type of nanolamellar materials, the synthetic routes developed so far are restricted to MOFs possessing layered structures, limiting further development in this field. Here, a bottom‐up surfactant‐assisted synthetic approach is presented for the fabrication of nanosheets of various nonlayered MOFs, broadening the scope of MOF nanosheets application. Surfactant‐assisted preorganization of the metallic precursor prior to MOF synthesis enables the manufacture of nonlayered Al‐containing MOF lamellae. These MOF nanosheets are shown to exhibit a superior performance over other crystal morphologies for both chemical sensing and gas separation. As revealed by electron microscopy and diffraction, this superior performance arises from the shorter diffusion pathway in the MOF nanosheets, whose 1D channels are oriented along the shortest particle dimension.
Synthesis of an All‐Ferric Cuboidal Iron–Sulfur Cluster [FeIII4S4(SAr)4]
Authors: Moula Golam , Matsumoto Tsuyoshi , Miehlich Matthias E. , Meyer Karsten , Tatsumi Kazuyuki 
Published: May 2018

AbstractAn unprecedented, super oxidized all‐ferric iron–sulfur cubanoid cluster with all terminal thiolates, Fe4S4(STbt)4 (3) [Tbt=2,4,6‐tris{bis(trimethylsilyl)methyl}phenyl], has been isolated from the reaction of the bis‐thiolate complex Fe(STbt)2 (2) with elemental sulfur. This cluster 3 has been characterized by X‐ray crystallography, zero‐field 57Fe Mössbauer spectroscopy, cyclic voltammetry, and other relevant physico‐chemical methods. Based on all the data, the electronic ground state of the cluster has been assigned to be Stot=0.
Visible‐Light‐Induced Organic Photochemical Reactions through Energy‐Transfer Pathways
Authors: Zhou Quan‐Quan , Zou You‐Quan , Lu Liang‐Qiu , Xiao Wen‐Jing 
Published: May 2018

AbstractVisible‐light photocatalysis is a rapidly developing and powerful strategy to initiate organic transformations, as it closely adheres to the tenants of green and sustainable chemistry. Generally, most visible‐light‐induced photochemical reactions occur through single‐electron transfer (SET) pathways. Recently, visible‐light‐induced energy‐transfer (EnT) reactions have received considerable attentions from the synthetic community as this strategy provides a distinct reaction pathway, and remarkable achievements have been made in this field. In this Review, we highlight the most recent advances in visible‐light‐induced EnT reactions.
Highly efficient CO2 capture with a metal–organic framework‐derived porous carbon impregnated with polyethyleneimine
Authors: Salehi Samira , Anbia Mansoor 
Published: May 2018

Global warming is considered as one of the great challenges of the twenty‐first century. Application of CO2 capture and storage technologies to flue gas is considered to be a useful method of lessening global warning. Highly porous carbon has played an important role in tackling energy and environmental problems. We attempted to synthesize a highly porous carbon adsorbent by carbonizing a highly crystalline metal–organic framework (MOF) without any carbon precursors and focused on the adsorption of CO2 and CH4 gases and CO2/CH4 selectivity at 298, 323 and 348 K using a volumetric apparatus. The MOF‐derived porous carbon (MDC) was prepared by direct carbonization of MOF‐199 as a template at 900 °C under nitrogen atmosphere. Amino‐impregnated MDC samples exhibited enhanced adsorption capacities by a combination of physical and chemical adsorption. Polyethyleneimine (PEI) was selected as the amine source, which was found to greatly enhance CO2 capture when supported on the porous carbon. Novel PEI‐impregnated MDC nanocomposites were synthesized by wetness impregnation and then characterized using various methods.
Preliminary results of an integrated archaeo‐geophysical survey on the basis of ancient finds unearthed by an illegal excavation at Kılıç Ören site (Isparta, Turkey)
Authors: Yilmaz Sedat , Oksum Erdinc , Cakmak Olcay , Dogan Onur , Tekelioğlu Erkan 
Published: May 2018

AbstractAn archaeo‐geophysical study was performed at the Ören site (Kılıç village north of Isparta, Turkey) where an illegal excavation revealed a monumental relic which is thought to belong to the Roman period. Therefore, an area, which is about 0.2 ha in size around the illegal excavation location, has been investigated using electrical resistivity imaging, ground penetrating radar and magnetic methods to determine the presence and extent of buried archaeological remains. The data sets were evaluated with inversion, signal and image processing techniques. The integrated usage of the results revealed the shape, extent and the depth of buried archaeological remains, which have regular geometry in some locations of the investigated site. These results indicate the presence of regular archaeological features and architectural planning in the area.
The Lupus‐Associated Fcγ Receptor IIb–I232T Polymorphism Results in Impairment in the Negative Selection of Low‐Affinity Germinal Center B Cells Via c‐Abl in Mice
Authors: Jhou Jyun‐Pei , Yu I‐Shing , Hwai Haw , Chen Chih‐Shan , Chen Pei‐Lung , Tzeng Shiang‐Jong 
Published: May 2018

ObjectiveFcγ receptor IIb (FcγRIIb) is an essential negative regulator of B cells that blocks B cell receptor (BCR) signaling and triggers c‐Abl–dependent apoptosis of B cells. FcγRIIb‐deficient mice display splenomegaly with expansion of B cells, leading to lupus. FcγRIIb‐I232T is a hypofunctional polymorphism associated with lupus susceptibility in humans, an autoimmune disease linked to diminished deletion of autoreactive B cells. In the context of the FcγRIIb‐I232T polymorphism, we investigated the role of FcγRIIb in the deletion of low‐affinity germinal center (GC) B cells, an important mechanism for preventing autoimmunity.MethodsWe generated FcγRIIb232T/T mice to mimic human FcγRIIb‐I232T carriers and immunized mice with chicken gamma globulin (CGG)–conjugated NP, a T cell–dependent antigen, to examine the response of GC B cells.ResultsCompared to wild‐type (WT) mice, FcγRIIb232T/T mice showed increased numbers of low‐affinity NP‐specific IgG and NP‐specific B cells and plasma cells; additionally, the expression of a somatic mutation (W33L) in their VH186.2 genes encoding high‐affinity BCR was reduced. Notably, FcγRIIb232T/T mice had a higher number of GC light zone B cells and showed less apoptosis than WT mice, despite having equivalent follicular helper T cell numbers and function. Moreover, phosphorylation of c‐Abl was reduced in FcγRIIb232T/T mice, and treatment of WT mice with the c‐Abl inhibitor nilotinib during the peak of GC response resulted in reduced affinity maturation reminiscent of FcγRIIb232T/T mice.ConclusionOur findings provide evidence of a critical role of FcγRIIb/c‐Abl in the negative selection of GC B cells in FcγRIIb232T/T mice. Importantly, our findings indicate potential benefits of up‐regulating FcγRIIb expression in B cells for treatment of systemic lupus erythematosus.
Cox model with interval‐censored covariate in cohort studies
Authors: Ahn Soohyun , Lim Johan , Paik Myunghee Cho , Sacco Ralph L. , Elkind Mitchell S. 
Published: May 2018

AbstractIn cohort studies the outcome is often time to a particular event, and subjects are followed at regular intervals. Periodic visits may also monitor a secondary irreversible event influencing the event of primary interest, and a significant proportion of subjects develop the secondary event over the period of follow‐up. The status of the secondary event serves as a time‐varying covariate, but is recorded only at the times of the scheduled visits, generating incomplete time‐varying covariates. While information on a typical time‐varying covariate is missing for entire follow‐up period except the visiting times, the status of the secondary event are unavailable only between visits where the status has changed, thus interval‐censored. One may view interval‐censored covariate of the secondary event status as missing time‐varying covariates, yet missingness is partial since partial information is provided throughout the follow‐up period. Current practice of using the latest observed status produces biased estimators, and the existing missing covariate techniques cannot accommodate the special feature of missingness due to interval censoring. To handle interval‐censored covariates in the Cox proportional hazards model, we propose an available‐data estimator, a doubly robust‐type estimator as well as the maximum likelihood estimator via EM algorithm and present their asymptotic properties. We also present practical approaches that are valid. We demonstrate the proposed methods using our motivating example from the Northern Manhattan Study.
Evidence for the Formation of a Radical‐Mediated Flavin‐N5 Covalent Intermediate
Authors: Dai Yumin , Valentino Hannah , Sobrado Pablo 
Published: May 2018

AbstractThe redox‐neutral reaction catalyzed by 2‐haloacrylate hydratase (2‐HAH) leads to the conversion of 2‐chloroacrylate to pyruvate. Previous mechanistic studies demonstrated the formation of a flavin‐iminium ion as an important intermediate in the 2‐HAH catalytic cycle. Time‐resolved flavin absorbance studies were performed in this study, and the data showed that the enzyme is capable of stabilizing both anionic and neutral flavin semiquinone species. The presence of a radical scavenger decreases the activity in a concentration‐dependent manner. These data are consistent with the flavin iminium intermediate occurring by radical recombination.
Edwards Sapien XT® pulmonic valve compression after resuscitation and successful redilatation
Authors: Lehner Anja , Kantzis Marinos , Haas Nikolaus A. 
Published: May 2018

AbstractDespite the increasing use of percutaenous valves, little is known about valve performance after external chest compression. We report a case of a compressed pulmonary Edwards Sapien® XT valve after resuscitation. With the patient on ECMO, successful redilatation was performed with unimpaired postprocedural valve function. We aim to increase the awareness for valve distortion after external chest compression with increasing numbers of transcatheter valvulations. We suggest that immediate re‐evaluation of the implanted device via biplane fluoroscopy is mandatory after resuscitation in such cases.
An efficient method for autoencoder‐based collaborative filtering
Authors: Wang Yi‐Lei , Tang Wen‐Zhe , Yang Xian‐Jun , Wu Ying‐Jie , Chen Fu‐Ji 
Published: May 2018

SummaryCollaborative filtering (CF) is a widely used technique in recommender systems. With rapid development in deep learning, neural network‐based CF models have gained great attention in the recent years, especially autoencoder‐based CF model. Although autoencoder‐based CF model is faster compared with some existing neural network‐based models (eg, Deep Restricted Boltzmann Machine‐based CF), it is still impractical to handle extremely large‐scale data. In this paper, we practically verify that most non‐zero entries of the input matrix are concentrated in a few rows. Considering this sparse characteristic, we propose a new method for training autoencoder‐based CF. We run experiments on two popular datasets MovieLens 1 M and MovieLens 10 M. Experimental results show that our algorithm leads to orders of magnitude speed‐up for training (stacked) autoencoder‐based CF model while achieving comparable performance compared with existing state‐of‐the‐art models.
Evaluation of SnSe crystals fabricated by temperature gradient method with double tubes seal
Authors: Tsujioka Yusuke , Tahashi Masahiro , Ichino Yusuke , Tsuchiya Yuji , Goto Hideo , Yoshida Yutaka 
Published: May 2018

AbstractThermoelectric power generation can effectively utilize waste heat. ZT representing the performance of thermoelectric materials is required to have a value of 2 or more for the applications. SnSe with a high ZT of 2.6 has an anisotropy of thermoelectric properties due to the crystal structure. Since heat exists in various places, many SnSe single crystals are considered to be necessary. Here we attempted to grow single crystals of SnSe by a temperature gradient method as a simple technique. Also we prevented evaporation of SnSe with double tubes seal. We fabricated SnSe crystals at the cooling rates of 5, 10, and 50℃/h using MgO (100) single crystalline substrate as seed crystal. The SnSe crystal fabricated at a cooling rate of 50℃/h was shown to be polycrystal. On the other hand, the SnSe crystal fabricated at a slower cooling rate of 10℃/h was shown to be pseudo‐single crystal with stoichiometric composition. The temperature dependence of the electric conductivity and the Seebeck coefficient of the SnSe crystals was the same tendency as that of SnSe single crystal.
Development of a fast CE method for high throughput screening of ecto‐5′‐nucleotidase inhibitors
Authors: Raza Rabia , Bai Yu , Liu Huwei 
Published: May 2018

AbstractOverexpression of ecto‐5′‐nucleotidase is found to be linked to cancer progression and other diseases which makes screening of its inhibitors on demand. Unfortunately, there is scarcity of reported ecto‐5′‐nucleotidase inhibitors because of unavailability of simple, fast and efficient methods to study its inhibition. In this study, we have developed a very fast, reverse polarity capillary electrophoresis based method for screening of ecto‐5′‐nucleotidase inhibitors. Both EOF and electrophoretic mobility were maintained in same direction by dynamically coating lining of capillary and applying negative voltage, resulting in appearance of both adenosine monophosphate (AMP) and adenosine peaks in less than 2 min. Separations were performed in reverse polarity using ‐20 kV. Hexadimethrine bromide (HDB) was used as a buffer additive (0.025% in 40 mM borate buffer). An online sample stacking was attained by a special sweeping effect which enabled a long (65 s) injection time without compromise in peak shape. Using this newly developed method, both AMP and adenosine peaks were obtained with a baseline resolution, in less than two minutes. Method was validated by measuring km, and Vmax values of human ecto‐5′‐nucleotidas and Ki value of standard inhibitor quercitin against this enzyme. Method is simple and fast and can be conveniently optimized for high throughput screening of ecto‐5′‐nucleotidase inhibitors.
Controls on the aerodynamic roughness length and the grain‐size dependence of aeolian sediment transport
Authors: Field J.P. , Pelletier J.D. 
Published: May 2018

AbstractEstimates of the wind shear stress exerted on Earth's surface using the fully rough form of the law‐of‐the‐wall are a function of the aerodynamic roughness length, z0. Accurate prediction of aeolian sediment transport rates, therefore, often requires accurate estimates of z0. The value of z0 is determined by the surface roughness and the saltation intensity, both of which can be highly dynamic. Here we report field measurements of z0 values derived from velocity profiles measured over an evolving topography (i.e. sand ripples). The topography was measured by terrestrial laser scanning and the saltation intensity was measured using a disdrometer. By measuring the topographic evolution and saltation intensity simultaneously and using available formulae to estimate the topographic contribution to z0, we isolated the contribution of saltation intensity to z0 and document that this component dominates over the topographic component for all but the lowest shear velocities. Our measurements indicate that the increase in z0 during periods of saltation is approximately one to two orders of magnitude greater than the increase attributed to microtopography (i.e. evolving sand ripples). Our results also reveal differences in transport as a function of grain size. Each grain‐size fraction exhibited a different dependence on shear velocity, with the saltation intensity of fine particles (diameters ranging from 0.125 to 0.25 mm) saturating and eventually decreasing at high shear velocities, which we interpret to be the result of a limitation in the supply of fine particles from the bed at high shear velocities due to bed armoring. Our findings improve knowledge of the controls on the aerodynamic roughness length and the grain‐size dependence of aeolian sediment transport. The results should contribute to the development of improved sediment transport and dust emission models. © 2018 John Wiley & Sons, Ltd.
Flammability hazards of typical fuels used in wind turbine nacelle
Authors: Zhenhua Wang , Fei You , Rein Guillermo , Juncheng Jiang , Xuefeng Han , Junhua Han , Wei Sun 
Published: May 2018

SummaryThis study aims to develop a complete methodology for assessing flammability hazards of typical fuels (ie, transformer oil, hydraulic oil, gear oil, and lubricating grease) used in a wind turbine nacelle by combining different experimental techniques such as thermogravimetric analysis and cone calorimetry. Pyrolysis properties (onset temperature, temperature of maximum mass loss rate, and mass residue) and reaction‐to‐fire properties (ignition time, heat release rate, mass loss rate, and smoke release rate) were determined and used for a preliminary assessment of thermal stability and flammability hazards. Additional indices, for ignition and thermal behavior (effective heat of combustion, average smoke yield, and smoke point height, heat release capacity, fire hazard parameter, and smoke parameter, were calculated to provide a more advanced assessment of the hazards in a wind turbine. Results show that pyrolysis of transformer oil, lubricating grease, hydraulic oil, and gear oil occur in the range of 150°C to 550°C. Lubricating grease and transformer oil show the higher and lower thermal stabilities with maximum pyrolysis rate temperatures of 471°C and 282°C, respectively. The measured relation between ignition time and radiant heat flux agrees well with Janssens method (a power of 0.55). The aforementioned indices appear to provide a reasonable prediction of performance under real fire conditions according to a full‐scale fire test documented by Declercq and Van Schevensteen. The results of the study indicate that transformer oil is the easiest to ignite while lubricating grease is the most difficult to ignite but also has the highest smoke production rate; that transformer oil has the highest heat release rate while gear oil has the lowest; and that the fire hazard parameter is the highest for transformer oil and the smoke parameter is the highest for lubricating grease. The potential of this type of work to design safer wind turbines under performance‐based approaches is clearly clarified.