bluuebunny/crossref_metadata_2025_split huggingface dataset:
Amorphous Pure Organic Polymers for Heavy‐Atom‐Free Efficient Room‐Temperature Phosphorescence Emission
Authors: Ma Xiang , Xu Chao , Wang Jie , Tian He 
Published: May 2018

AbstractPure organic, heavy‐atom‐free room‐temperature phosphorescence (RTP) materials have attracted much attention and have potential applications in photoelectric and biochemical material fields owing to their rich excited state properties. They offer long luminescent lifetime, diversified design, and facile preparation. However, recent achievements of efficient phosphorescence under ambient conditions mainly focus on ordered crystal lattices or embedding into rigid matrices, which require strict growth conditions and have poor reproducibility. Herein, we developed a concise approach to give RTP with a decent quantum yield and ultralong phosphorescence lifetime in the amorphous state by radical binary copolymerization of acrylamide and different phosphors with oxygen‐containing functional groups. The cross‐linked hydrogen‐bonding networks between the polymeric chains immobilize phosphors to suppress non‐radiative transitions and provide a microenvironment to shield quenchers.
Trimethyl Orthoacetate and Ethylene Glycol Mono‐Vinyl Ether as Enolate Surrogates in Enantioselective Iridium‐Catalyzed Allylation
Authors: Sempere Yeshua , Carreira Erick M. 
Published: May 2018

AbstractTrimethyl orthoacetate and ethylene glycol mono‐vinyl ether are employed in iridium‐catalyzed enantioselective allylation reactions. The method documented enables their convenient use as surrogates for silyl ketene acetals and silyl enol ethers to prepare γ,δ‐unsaturated esters and protected aldehydes with excellent enantioselectivity. The utility of this novel method has been demonstrated by its implementation in a formal enantioselective synthesis of the meroterpenoid (+)‐conicol.
The Interhalogen Cations [Br2F5]+ and [Br3F8]+
Authors: Ivlev Sergei I. , Karttunen Antti J. , Buchner Magnus R. , Conrad Matthias , Kraus Florian 
Published: May 2018

AbstractThe synthesis and characterization of unique polyhalogen cations containing μ‐bridging fluorine atoms are reported. The [Br2F5]+ cation features a symmetric [F2Br–μ‐F–BrF2] bridge, whereas the [Br3F8]+ contains asymmetric μ‐F bridges. These fluoronium ions, obtained as [SbF6]− salts, were investigated using Raman and 19F NMR spectroscopy, as well as single‐crystal X‐ray diffraction. Quantum chemical calculations were carried out for the gas‐phase cations as well as for the solid‐state compounds. Population analyses show the μ‐F atoms to possess the most negative partial charge within the cations.
Oligomeric Composition of Polyols From Fatty Acid Methyl Ester: The Effect of Ring‐Opening Reactants of Epoxide Groups
Authors: Tuan Ismail Tuan Noor Maznee , Ibrahim Nor Azowa , Mohd Noor Mohd Azmil , Hoong Seng Soi , Poo Palam Kosheela Devi , Yeong Shoot Kian , Idris Zainab , Schiffman Christi M. , Sendijarevic Ibrahim , Abd Malek Emilia , Zainuddin Norhazlin , Sendijarevic Vahid 
Published: May 2018

AbstractCommercial availability of fatty acid methyl ester (FAME) from palm oil targeted for biodiesel offers a good feedstock for the production of structurally well‐defined polyols for polyurethane applications. The effect of molecular weight (MW), odd and even carbon numbers, and the linear and branched structure reactants used in the ring‐opening reaction of epoxidized fatty acid methyl ester (E‐FAME) on the properties of polyols was investigated. Conversions of E‐FAME to PolyFAME polyols were confirmed by Fourier transform infrared analysis, oxirane oxygen content, and hydroxyl number. Gel permeation chromatography (GPC) calibrated against polyether polyols as a standard and vapor pressure osmometry were used for MW determination. GPC chromatograms of PolyFAME polyols clearly demonstrated the formation of oligomers during ring‐opening reactions. MW, and odd and even carbon numbers in a structure of linear diols and branched diol used in the syntheses of PolyFAME polyols did not have an effect on crystallinity, glass transition, or melt temperatures measured using Differential scanning calorimetry (DSC). PolyFAME polyols ring‐opened with water, methanol, and 1,2‐propanediol contained secondary hydroxyl groups, whereas PolyFAME polyols ring‐opened with linear diols contained a mixture of primary and secondary hydroxyl groups. It was found that the concentration of primary hydroxyl groups increased significantly by increasing the number of carbons from C2 to C3 in the linear diols. The viscosity of PolyFAME polyols also increased with the MW of linear diols used in the E‐FAME ring‐opening reaction. These findings would be beneficial for formulators in choosing the most cost effective polyols for polyurethane formulations.
Core–shell PVA/gelatin nanofibrous scaffolds using co‐solvent, aqueous electrospinning: Toward a green approach
Authors: Sengor Mustafa , Ozgun Alp , Corapcioglu Gulcan , Ipekoglu Mehmet , Garipcan Bora , Ersoy Nuri , Altintas Sabri 
Published: May 2018

ABSTRACTElectrospinning (ES) of gelatin often requires cytotoxic organic solvents or acidic environments, which deteriorate cell recognition sites. In this study, aqueous, non‐toxic, co‐solvent ES was performed to obtain core–shell poly(vinyl alcohol) (PVA)/gelatin nanofiber scaffolds. Effects of the core/shell feed rate ratio (FRR) were investigated on a morphological and mechanical basis. PVA:gelatin ratio of 1:4 was the limiting ratio for specific voltage and electrode distance parameters to obtain uniform fibers. Core–shell bead‐free structures were obtained at 8% PVA and gelatin aqueous solutions. A mean diameter of 280 nm was obtained for 1:1 FRR at 15 kV and 15 cm of electrode distance. Crosslinking resulted in slight improvement in tensile strengths and severe decrease in ductility. Fourier transform infrared spectra revealed retention and improvement of stable secondary structures of gelatin after ES. The scaffolds almost degraded more than 60% in 14 days. Based on the results, present scaffolds hold great promise as suitable candidates for biomedical applications. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46582.
Rapid screening test for flame retardation of wood, and its applicability to thermoplastic polymer systems
Authors: Deans Taneisha , Li Yuqin , Jefferson Lamia , Schiraldi David A. 
Published: May 2018

ABSTRACTA rapid screening process was developed to investigate the flame‐retardant properties of new materials and compositions. Wooden tongue depressors (“sticks”) were coated in solutions/suspensions of compositions of interest and tested in a method similar to that of the UL‐94 vertical burn test. The concentration of additives applied to the wooden sticks, as well as the additive application and drying times influenced the burning performance of the sticks, a useful screening method for testing flame retardants applied to wood products. The most promising combination of flame retardants from the wooden stick tests were then compounded into polyolefins, which were tested according to the UL(94) vertical burn protocol. A strong correlation was found between UL(94) results for low density polyethylene, high density polyethylene and polypropylene, and the wooden stick flammability data. This test, therefore, shows promise as a simple, inexpensive, and rapid way to screen new materials and compositions for flammability. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46602.
“Japan is back”: Autonomy and balancing amidst an unstable China–U.S.–Japan triangle
Authors: Fatton Lionel P. 
Published: May 2018

AbstractJapan's security policy has changed dramatically in recent years. The country balances harder against China, and its armed forces are increasingly autonomous from their American counterparts. What explains Japan's growing autonomy and balancing tendency after decades of relative apathy? I argue that this new strategic orientation results from unprecedented doubts about the effectiveness of its traditional security policy amidst an unstable China–U.S.–Japan triangular relationship. Tokyo is increasingly uncertain about American security commitments in the face of a more assertive China. As both the alliance with the United States and the accommodation of China are becoming unsuitable strategies for guaranteeing national security, Japan reverts to a more autonomous and resolute posture. Japan's new security policy will have important consequences for the triangular relationship.
The behavioral study on the interactive aggravation between pruritus and depression
Authors: Wang Xiao‐Dong , Yang Gang , Bai Yang , Feng Yu‐Peng , Li Hui 
Published: May 2018

AbstractBackgroundThe interactive aggravation of pruritus and depression is well‐known, but an appropriate experimental model that could mimic this behavioral phenomenon is still lacking. Thus, a systematic animal behavioral investigation was carried out in this study. This will promote the research and treatment of pruritus and depression.MethodsThe 2,4‐dinitrofluorobenzene (DNFB)‐induced chronic itch model was established to measure the depression index by forced swimming test (FST), tail suspension test (TST), and splash test (ST). The chronic unpredicted mild stress (CUMS)‐induced depression model was established to measure spontaneous itch and acute histamine or chloroquine‐induced itch behaviors. A depression and itch combining model was also established to measure the scratching and depression behaviors. The motor function of DNFB mice was analyzed by the rotarod test.ResultsThe scratching number, the immobility time in the FST and TST, and the grooming number in the ST test were all significantly increased in the chronic itch model. Mice receiving CUMS treatment showed significantly increased spontaneous scratching number, immobility time in the FST and TST tests, and grooming number in the ST. The combined model showed increased immobility time in FST and TST tests and increased grooming number in ST comparing to the depression model, and showed increased scratching number comparing to the chronic itch model. After histamine (His) or chloroquine (CQ) injection, the scratching numbers of CUMS mice were all significantly increased compared to those of His‐ and CQ‐control, respectively. Anti‐depression drug ketamine could significantly inhibit the depression‐like behaviors of CUMS mice, and simultaneously stopped the promoting effect on His‐induced acute itch.ConclusionsThis study established an appropriate cross aggravation experimental mode and demonstrated that there is cross aggravation between pruritus and depression. The illumination of related mechanisms underlying this cross aggravation effect will provide theoretical basis for the prevention and treatment of depression and pruritus.
A fast garment fitting algorithm using skeleton‐based error metric
Authors: Wu Nannan , Deng Zhigang , Huang Yue , Liu Chen , Zhang Dongliang , Jin Xiaogang 
Published: May 2018

AbstractWe present a fast and automatic method to fit a given 3D garment onto a human model with various shapes and poses, without using a reference human model. Our approach uses a novel skeleton‐based error metric to find the pose that best fits the input garment. Specifically, we first generate the skeleton of the given human model and its corresponding skinning weights. Then, we iteratively rotate each bone to find its best position to fit the garment. After that, we rig the surface of the human model according to the transformations of the skeleton. Potential penetrations are resolved using collision handling and physically based simulation. Finally, we restore the human model back to the original pose in order to obtain the desired fitting result. Our experiment results show that besides its efficiency and automation, our method is about two orders of magnitudes faster than existing approaches, and it can handle various garments, including jacket, trousers, skirt, a suit of clothing, and even multilayered clothing.
Effects of interface on procedural skill transfer in virtual training: Lifeboat launching operation study
Authors: Jung Jinki , Ahn Young Joong 
Published: May 2018

AbstractA comparative study assessing the effect of interface type on procedural skill transfer during virtual training is presented. The aim of this research is to evaluate the transferability of two aspects of procedural skills, that is, procedural knowledge and technical skills. We established one group with a lecture and three virtual training groups with a combination of output and input devices: a monitor and keyboard/mouse, a head‐mounted display (HMD) and joypad, and an HMD and wearable sensors. The task for assessment was a lifeboat launching operation that requires a participant to memorize a 10‐step procedure utilizing 14 different pieces of equipment that should be manipulated in each step. Before and after training, we evaluated the participants' procedural knowledge and technical skill on a real lifeboat. The monitor and keyboard/mouse group showed the best performance in a procedural knowledge assessment that addressed visually induced recollections from the real lifeboat. Alternatively, in the assessment of technical skills that determined manipulation ability that requires word‐based mnemonics, the HMD and wearable sensors group outperformed the other groups. Moreover, the results showed that the virtual training was a more efficient training format for short‐term training than a lecture due to the freedom of observation viewpoint, despite simulator sickness.
The semantic space for motion‐captured facial expressions
Authors: Castillo S. , Legde K. , Cunningham D. W. 
Published: May 2018

AbstractWe cannot not communicate! During our daily lives, we convey information verbally and nonverbally. Most of the affective meaning of a message is transferred with the help of facial expressions, and thereby, when trying to establish a realistic human‐like virtual character, we should pay close attention to the animation. Motion capture is one of the most common techniques, but due to the wide range of expressions humans use, the recording time and data needed are vast. To address this problem, we propose the use of semantic spaces as they help in characterizing and positioning expressions by finding a correlation between them. In this paper, we extend prior research by providing the semantic spaces underlying real videos and motion capture data for a total of 62 conversational expressions. Our results highly correlate with previous work, showing that our new expressions were correctly recognized. Moreover, our results can be used in future work to directly project potential new recordings of these 62 expressions on the found spaces.
Evaluating enjoyment, presence, and emulator sickness in VR games based on first‐ and third‐ person viewing perspectives
Authors: Monteiro Diego , Liang Hai‐Ning , Xu Wenge , Brucker Marvin , Nanjappan Vijayakumar , Yue Yong 
Published: May 2018

AbstractMany virtual reality (VR) games are based on a first‐person perspective (1PP). There are, however, advantages in using another perspective, such as the third‐person perspective (3PP). Although there has been some research evaluating the effect of 1PP and 3PP in gameplay experiences, it is largely unexplored for VR games played via the new generation of commercial head‐mounted display systems, such as the Oculus Rift. In this research we want to shed some light on the relationship between the different perspectives, when games are played using head‐mounted display VR, and simulator sickness, enjoyment, and presence. To do so, we perform an experiment using two different perspectives (1PP and 3PP) and displays (VR and a conventional display) with a popular game. Our findings indicate that 3PP‐VR is less likely to make people have simulator sickness when compared with 1PP‐VR. However, the former is not perceived as immersive, but this might not be a problem because our data also show that presence is not mandatory for enjoyment. Also, the data suggest that there is no clear preference between 1PP‐VR and 3PP‐VR for gameplay.
Overexpression of genes associated with hypoxia in cattle adapted to Trans Himalayan region of Ladakh
Authors: Verma Preeti , Sharma Ankita , Sodhi Monika , Thakur Kiran , Bharti Vijay K , Kumar Prabhat , Giri Arup , Kalia Sahil , Swami Shelesh Kumar , Mukesh Manishi 
Published: May 2018

AbstractLadakh is an important part of the Trans‐Himalayan region located between the Kunlun mountain range in the north and the main Great Himalayas to the south in the state of Jammu and Kashmir of India. The local cattle from Leh and Ladakh region, known as “Ladakhi cattle” is a unique germplasm having an excellent adaptation potential to high altitude hypobaric stress. In the present study, an effort was made to evaluate the transcriptional pattern of hypoxia inducing factor‐1 (HIF‐1) and several of its regulated genes in PBMCs of local Ladakhi cattle, Holstein Frisian crosses, Jersey (exotic) maintained at high altitude region and Sahiwal (Bos indicus) and Karan Fries (cross bred) cattle maintained in tropical environment. The combined data set indicated increased expression of HIF‐1 and its regulated genes viz., glucose transporter 1 (GLUT1), vascular endothelial growth factor (VEGF), and hexokinase (HK2) in high altitude cattle indicating their importance in maintaining cellular homeostasis during high altitude hypoxia. The data indicated that hypoxia associated genes accumulated under hypoxic conditions are part of an essential adaptive component for adaptation to the high altitude of the trans‐Himalayan region. In contrary, higher expression of molecular chaperons’ viz., HSP70 and HSP90 in tropically adapted cattle give tolerance to high ambient temperature prevalent in tropical condition. In conclusion, HIF‐1 and its regulatory genes could be termed as important candidates for producing homeostatic responses to hypoxia in cattle populations reared in higher altitudes of the Trans‐Himalayan region.
Oxygen Reduction on Fe‐ and Co‐Containing Nitrogen‐Doped Nanocarbons
Authors: Kisand Kaarel , Sarapuu Ave , Peikolainen Anna‐Liisa , Seemen Helina , Kook Mati , Käärik Maike , Leis Jaan , Sammelselg Väino , Tammeveski Kaido 
Published: May 2018

AbstractCobalt‐ and iron‐containing nitrogen‐doped carbon nanomaterials are synthesised from 5‐methylresorcinol‐formaldehyde resin nanospheres by pyrolysis in the presence of nitrogen and metal precursors. Two approaches used for the synthesis yield the catalysts of different morphology, consisting of spherical or irregular porous carbon structures. The electrocatalytic properties of the materials towards the oxygen reduction reaction (ORR) in alkaline solution are evaluated by thin‐film rotating disk electrode method. The catalysts containing transition metals exhibit enhanced electrocatalytic activity for ORR as compared to the metal‐free nitrogen‐doped materials, cobalt‐containing catalysts being slightly more active than iron‐based materials. The structure and surface composition of the materials are characterised by scanning electron microscopy, N2 adsorption studies and X‐ray photoelectron spectroscopy.
Composite Electrocatalyst Derived from Hybrid Nitrogen‐Containing Metal Organic Frameworks and g‐C3N4 Encapsulated In Situ into Porous Carbon Aerogels
Authors: Zhu Hong , Chen Minglin , Li Ke , Huang Xidai , Wang Fanghui 
Published: May 2018

AbstractA novel composite Fe‐bpdc‐C3N4‐CA catalyst (where bpdc stands for 2,2′‐bipyridine‐3,3′‐dicarboxylic acid and CA stands for carbon aerogel) with a high nitrogen content was synthesized through the in situ encapsulation of nitrogen‐containing metal organic frameworks along with g‐C3N4 into porous CAs. The characteristics of the catalysts calcined at different temperatures were determined by means of TEM, XRD, Raman spectroscopy, XPS, and BET measurements. The results demonstrate the successful doping of N heteroatoms and the effective formation of Fe‐NX active sites. The electrocatalytic properties were investigated by using rotating disk electrode (RDE) and rotating ring disk electrode (RRDE) measurements. The Fe‐bpdc‐C3N4‐CA catalyst calcined at 800 °C exhibits the highest oxygen reduction reaction activity with the initial reduction potential and half‐wave potential reaching 1.09 and 0.96 V, respectively, versus RHE in 0.1 M KOH. It also possesses high stability and follows approximately a complete four‐electron (4e−) reaction pathway, as commercial Pt/C catalysts do.
Influence of the Crystal Structure of Titanium Oxide on the Catalytic Activity of Rh/TiO2 in Steam Reforming of Propane at Low Temperature
Authors: Yu Lin , Sato Katsutoshi , Toriyama Takaaki , Yamamoto Tomokazu , Matsumura Syo , Nagaoka Katsutoshi 
Published: May 2018

AbstractSolid oxide fuel cells (SOFCs) with liquefied petroleum gas (LPG) reduce CO2 emissions due to their high‐energy‐conversion efficiency. Although SOFCs can convert LPG directly, coking occurs easily by decomposition of hydrocarbons, including C−C bonds on the electrode of fuel cell stacks. It is therefore necessary to develop an active steam pre‐reforming catalyst that eliminates the hydrocarbons at low temperature, in which waste heat of SOFCs is used. Herein, we show that the crystal structure of the TiO2 that anchors Rh particles is crucial for catalytic activity of Rh/TiO2 catalysts for propane pre‐reforming. Our experimental results revealed that strong metal support interaction (SMSI) induced during H2 pre‐reduction were optimized over Rh/TiO2 with a rutile structure; this catalyst catalyzed the reaction much more effectively than conventional Rh/γ‐Al2O3. In contrast, the SMSI was too strong for Rh/TiO2 with an anatase structure, and the surface of the Rh particles was therefore covered mostly with partially reduced TiO2. The result was very low activity.
Relativistic Effects on Donor–Acceptor Interactions in Coinage Metal Carbonyl Complexes [TM(CO)n]+ (TM=Cu, Ag, Au; n=1, 2)
Authors: Poggel Christina , Frenking Gernot 
Published: May 2018

AbstractDFT calculations at the BP86+D3(BJ)/TZ2P level, with and without relativistic contributions, using the ZORA approximation have been carried out for the coinage metal carbonyl complexes [TM(CO)]+ and [TM(CO)2]+ with TM=Cu, Ag, Au. The nature of the metal‐CO interactions and the relativistic effects on the different energy terms were analyzed with the EDA‐NOCV method. The three terms Pauli repulsion, Coulomb attraction, and orbital interactions become stronger when relativistic effects are accounted for; the strengthening exhibits the order ΔEPauli>ΔEelstat>ΔEorb. The largest change in the calculated energy terms is, as expected, found for gold, followed by silver and copper. The relativistic contributions on the Cu+‐CO interactions are significant and thus, relativistic effects should not be neglected in quantum chemical calculations in copper compounds. Breakdown of the orbital term into individual contributions shows that the relativistic effect in [TM(CO)]+ is for the TM+←CO σ‐donation stronger than for TM+→CO π‐backdonation, except for TM=Cu. The trend in the dicarbonyls [TM(CO)2]+ has the order (+,+) σ‐donation > π‐backdonation > (+,−) σ‐donation. The bonding analysis reveals that there is a sizeable contribution from TM+→CO σ‐backdonation in all carbonyl complexes that further stabilizes the metal‐carbonyl bonds. In [Au(CO)2]+ it becomes even larger than the (+,−) OC→TM+←CO σ‐donation. The trends of the various orbital interactions and the effect of relativity on their strength can be understood when the valence orbitals of the metals and CO are considered.