bluuebunny/crossref_metadata_2025_split huggingface dataset:
Particle Transport–Based Triboelectric Nanogenerator for Self‐Powered Mass‐Flow Detection and Explosion Early Warning
Authors: Gu Guang Qin , Han Chang Bao , Bai Yu , Jiang Tao , He Chuan , Chen Bao Dong , Wang Zhong Lin 
Published: April 2018

AbstractIn the process of particle transport in pipes, particles get charged, and the discharge process can cause fire and explosion, which causes great harm to the safe production. In this paper, a particle transport triboelectric nanogenerator (PT‐TENG) based on particle transport in pipes is developed. The PT‐TENG can be utilized to monitor the mass‐flow of the particles and make explosion early warning without supplying the power. Under the condition of particles passing one by one, the moving speed of the particles can be obtained. When the particles transport continuously, the PT‐TENG can be used as a self‐powered detector to detect the mass flow of the particles in time. The mass flow detector can be installed both inside and outside the transport pipe. The PT‐TENG can be used as a power source to charge capacitors and light up light‐emitting diodes (LEDs). Moreover, a self‐powered explosion early warning device has been developed based on the PT‐TENG, which will have widespread application in the safety production.
Ultrahigh Brightness Carbon Dot–Based Blue Electroluminescent LEDs by Host–Guest Energy Transfer Emission Mechanism
Authors: Xu Jiacong , Miao Yanqin , Zheng Jingxia , Yang Yongzhen , Liu Xuguang 
Published: April 2018

AbstractUltrahigh brightness blue carbon dot–based light‐emitting diodes (CD‐LEDs) are fabricated by a host–guest doping method with poly(N‐vinylcarbazole) (PVK) as the host to realize the high brightness and pure emission of CD‐LEDs. Oleophylic CDs are synthesized as the dopant to obtain a wide range of doping concentration of CDs because oleophylic CDs and PVK can be well cosoluble in chlorobenzene at any doping concentration. Therefore, the CD‐LEDs emitting pure blue light that dominantly originates from CDs' emission are realized by optimizing the doping concentration. A host–guest energy transfer is the main emission mechanism for CDs. It is observed that CD‐LED also achieves a maximum luminance of 569.8 cd m−2, which is the highest luminance compared with ever reported blue CD‐LEDs.
A simple method for preparation of microcellularPLA/calcium carbonate nanocomposite using super critical nitrogen as a blowing agent: Control of microstructure
Authors: Mahdavi Mina , Yousefzade Omid , Garmabi Hamid 
Published: April 2018

AbstractA simple method was used to prepare microcellular foams of poly(lactic acid) (PLA) and its nanocomposites to improve its shortcomings such as low impact resistance and high cost. The batch foaming process of purePLAandPLAfilled with Nano calcium carbonate (NCC) was conducted using supercritical nitrogen (N2) as a blowing agent. The effect ofNCCon crystallization ofPLAis discussed as a remarkable parameter in foaming of semicrystalline polymers. Differential scanning calorimetry (DSC) was used to optimize the process temperature. The effect of foaming conditions (temperature, pressure, and cooling rate) and nanoparticle content on the foam microstructure ofPLAand its nanocomposites were investigated using scanning electron microscopy (SEM). Foams were obtained in the range of macro‐ and microscale (different cell sizes) using different foaming conditions. The results revealed that nanoparticles show excellent nucleation performance onPLAfoaming. Results of dynamic mechanical thermal analysis (DMTA) also showed significant influences ofNCCon foamed and prefoamed samples to different foaming structures.
Moss protonemata are dispersed by water, wind, and snails
Authors: Pasiche‐Lisboa Carlos J. , Jesús Inés Sastre‐De 
Published: April 2018

Premise of the StudyMosses produce asexual propagules, which are dispersed, thus allowing population establishment and maintenance. However, it is unknown if or how protonemata—one of their asexually produced propagules—are dispersed. Moss protonemata were exposed to three dispersal vectors (water, wind, and snails) to describe the dispersal capability and survival after dispersal.MethodsThe protonemata of mosses Callicostella belangeriana and Taxiphyllum taxirameum were splashed with water drops from a 1 or 2 m height, exposed to two wind velocities (V1 = 2.74 mps and V2 = 3.76 mps), and fed to terrestrial snails. Dispersal of protonemata was described for wind and water by studying the dispersal distance and the relationships between protonemata sizes and dispersal distances. Survival after dispersal was recorded for the three vectors.Key ResultsWater and wind dispersed protonemata up to 80 and 265.5 cm, respectively. The protonemata dispersed the farthest distance when splashed by 2 m drops and hit by V2 wind velocities. No, or little, relationship between protonemata size and dispersal distance was found for the water and wind vectors. Protonemata survived and became established after dispersal: survival was high when dispersed by water and snails, but was low for wind.ConclusionsFor the first time, it was shown that protonemata are dispersed mostly close to the source, which is suggested to aid in moss population maintenance.
Laboratory testing in BCR‐ABL1‐like (Philadelphia‐like) B‐lymphoblastic leukemia/lymphoma
Authors: Siegele Bradford J. , Nardi Valentina 
Published: April 2018

AbstractBCR‐ABL1‐like B‐lymphoblastic leukemia/lymphoma (BCR‐ABL1‐like B‐ALL), also known as Philadelphia‐like (Ph‐like) ALL, is a neoplasm of B‐lineage lymphoblasts characterized by a pattern of gene expression similar to that of B‐ALL with the BCR‐ABL1 translocation but lacking the BCR‐ABL1 fusion protein. The diagnosis of BCR‐ABL1‐like B‐ALL is associated with a high rate of relapse and poor clinical outcomes. In recognition of the difficulty in screening these leukemias for diagnostic workup, the 2016 update/revision to the World Health Organization (WHO) 2008 edition included BCR‐ABL1‐like B‐ALL as a provisional entity. This review addresses the various clinical considerations and methodologies currently used in the pathologic diagnosis, subclassification, and molecular characterization of cases of BCR‐ABL1‐like B‐ALL, with particular attention paid to emerging methods useful in identification of molecular lesions potentially amenable to targeted therapy.
Cascade Claisen Rearrangement: Rapid Synthesis of Polysubstituted Salicylaldehydes and Total Syntheses of Hemigossypol and Gossypol
Authors: Cao Tongxiang , Kong Yi , Luo Kui , Chen Lianfen , Zhu Shifa 
Published: April 2018

AbstractA cascade Claisen rearrangement of a well‐organized maltol propargyl ether for the construction of polysubstituted salicylaldehydes is reported. This reaction features high atom economy (100 %), as well as catalyst‐free and gram‐scale conditions. Based on this novel methodology, the total synthesis of hemigossypol, gossypol, and their analogues has been realized.
Zur Photochemie von Künstlerfarben: Strategien zur Verhinderung von Farbveränderungen in Kunstwerken
Authors: Miliani Costanza , Monico Letizia , Melo Maria J. , Fantacci Simona , Angelin Eva M. , Romani Aldo , Janssens Koen 
Published: April 2018

AbstractDie Absorption von Licht verleiht Pigmenten ihre Farbe – und damit den Grund ihrer Existenz –, erzeugt aber auch angeregte Zustände, d. h. neue Moleküle mit einem Energieüberschuss, der über Abbauwege dissipiert werden kann. Photoabbauprozesse rufen langfristige, kumulierte und irreversible Farbveränderungen hervor (Verblassung, Dunklung, Ausbleichung), deren Prognose und Verhinderung schwierige Herausforderungen darstellen. Von all den Umweltrisiken, die Kulturgüter beeinträchtigen, ist Lichteinfall das einzige, das nicht ohne Auswirkungen auf die optimale Präsentation des Ausstellungsstücks reguliert werden kann. Lichtinduzierte Veränderungen betreffen nicht nur die Pigmente selbst, sondern auch ihre Wechselwirkungen mit dem Trägermaterial und Bindemittel und werden selbst wiederum durch die Umgebungsbedingungen verkompliziert. In diesem Kurzaufsatz untersuchen wir, wie Chemie (insbesondere in Form mehrskaliger analytischer Studien von Kunstwerken), Computermodellierung und physikalische/chemische Studien dazu beitragen können, die ursprünglichen Erscheinungsbilder von Kunstwerken zu rekonstruieren und wirksame Konservierungsstrategien zu etablieren.
In Vitro Reconstitution of OxyC Activity Enables Total Chemoenzymatic Syntheses of Vancomycin Aglycone Variants
Authors: Forneris Clarissa C. , Seyedsayamdost Mohammad R. 
Published: April 2018

AbstractThe bioactivity of vancomycin is enabled by three aromatic crosslinks, the biosynthesis of which has been an active area of investigation for two decades. Two cytochrome P450 enzymes, OxyB and OxyA, have been shown to introduce bisaryl ether linkages with the help of a so‐called X‐domain. The final crosslink, however, a biaryl bond thought to be installed by OxyC, has remained elusive. We report the in vitro reconstitution of the OxyC reaction and formation of the first carbon–carbon crosslink in any glycopeptide antibiotic. Using a cascade sequence, in which the peptide substrate was incubated with the Oxy enzymes in turn, we completed the chemoenzymatic synthesis of a vancomycin aglycone variant. This approach was also used to generate a new analogue carrying a thioamide linkage at residue 4, a precursor to the amidine derivative, which is effective against vancomycin‐resistant pathogens. Our results set the stage for creating therapeutic vancomycin derivatives by using the native metalloenzymes.
Synthesis, Structure, Bonding, and Reactivity of Metal Complexes Comprising Diborane(4) and Diborene(2): [{Cp*Mo(CO)2}2{μ‐η2:η2‐B2H4}] and [{Cp*M(CO)2}2B2H2M(CO)4], M=Mo,W
Authors: Mondal Bijan , Bag Ranjit , Ghorai Sagar , Bakthavachalam K. , Jemmis Eluvathingal D. , Ghosh Sundargopal 
Published: April 2018

AbstractThe reaction of [(Cp*Mo)2(μ‐Cl)2B2H6] (1) with CO at room temperature led to the formation of the highly fluxional species [{Cp*Mo(CO)2}2{μ‐η2:η2‐B2H4}] (2). Compound 2, to the best of our knowledge, is the first example of a bimetallic diborane(4) conforming to a singly bridged Cs structure. Theoretical studies show that 2 mimics the Cotton dimolybdenum–alkyne complex [{CpMo(CO)2}2C2H2]. In an attempt to replace two hydrogen atoms of diborane(4) in 2 with a 2e [W(CO)4] fragment, [{Cp*Mo(CO)2}2 B2H2W(CO)4] (3) was isolated upon treatment with [W(CO)5⋅thf]. Compound 3 shows the intriguing presence of [B2H2] with a short B−B length of 1.624(4) Å. We isolated the tungsten analogues of 3, [{Cp*W(CO)2}2B2H2W(CO)4] (4) and [{Cp*W(CO)2}2B2H2Mo(CO)4] (5), which provided direct proof of the existence of the tungsten analogue of 2.
Maximizing the Number of Interfacial Sites in Single‐Atom Catalysts for the Highly Selective, Solvent‐Free Oxidation of Primary Alcohols
Authors: Li Tianbo , Liu Fei , Tang Yan , Li Lin , Miao Shu , Su Yang , Zhang Junying , Huang Jiahui , Sun Hui , Haruta Masatake , Wang Aiqin , Qiao Botao , Li Jun , Zhang Tao 
Published: April 2018

AbstractThe solvent‐free selective oxidation of alcohols to aldehydes with molecular oxygen is highly attractive yet challenging. Interfacial sites between a metal and an oxide support are crucial in determining the activity and selectivity of such heterogeneous catalysts. Herein, we demonstrate that the use of supported single‐atom catalysts (SACs) leads to high activity and selectivity in this reaction. The significantly increased number of interfacial sites, resulting from the presence of individually dispersed metal atoms on the support, renders SACs one or two orders of magnitude more active than the corresponding nanoparticle (NP) catalysts. Lattice oxygen atoms activated at interfacial sites were found to be more selective than O2 activated on metal NPs in oxidizing the alcohol substrate. This work demonstrates for the first time that the number of interfacial sites is maximized in SACs, providing a new avenue for improving catalytic performance by developing appropriate SACs for alcohol oxidation and other reactions occurring at metal–support interfacial sites.
Light‐Induced Reversible Reconfiguration of DNA‐Based Constitutional Dynamic Networks: Application to Switchable Catalysis
Authors: Wang Shan , Yue Liang , Li Zi‐Yuan , Zhang Junji , Tian He , Willner Itamar 
Published: April 2018

AbstractThe light‐induced reversible and cyclic reconfiguration of constitutional dynamic networks, consisting of supramolecular nucleic acid structures as constituents and a photoisomerizable trans/cis‐azobenzene‐functionalized nucleic acid as the trigger is demonstrated. In addition, the cyclic photochemical reconfiguration of the constitutional dynamic networks guides the switchable on/off operation of an emerging hemin/G‐quadruplex DNAzyme.
The Discovery of a Palladium(II)‐Initiated Borono‐Catellani Reaction
Authors: Chen Shuqing , Liu Ze‐Shui , Yang Tao , Hua Yu , Zhou Zhiyu , Cheng Hong‐Gang , Zhou Qianghui 
Published: April 2018

AbstractReported is a novel palladium(II)‐initiated Catellani‐type reaction that utilizes widely accessible aryl boronic acids as the substrates instead of aryl halides, thereby greatly expanding the existing scope of this powerful transformation. This borono‐Catellani reaction was promoted by cooperative catalysis between Pd(OAc)2 and the inexpensive 5‐norbornene‐2‐carbonitrile. Practicality is the striking feature of the reaction: it is run open to air at ambient temperature and no phosphine ligand is needed. This mild, chemoselective, and scalable protocol is compatible with a large range of readily available functionalized aryl boronic acids and bromides, as well as terminating olefins (50 examples, 39–97 % yields). Moreover, the orthogonal reactivity between the borono‐Catellani and classical Catellani reaction was demonstrated. This work is expected to open new avenues for developing novel Catellani‐type reactions.
Copper‐Catalyzed Heteroarylboration of 1,3‐Dienes with 3‐Bromopyridines: A cine Substitution
Authors: Smith Kevin B. , Huang Yuan , Brown M. Kevin 
Published: April 2018

AbstractA method for the heteroarylboration of 1,3‐dienes is presented. The process involves an unusual cine substitution of 3‐bromopyridine derivatives to deliver highly functionalized heterocyclic products. Mechanistic studies are included that clarify the details of this unusual process.
1,4‐Iron Migration for Expedient Allene Annulations through Iron‐Catalyzed C−H/N−H/C−O/C−H Functionalizations
Authors: Mo Jiayu , Müller Thomas , Oliveira João C. A. , Ackermann Lutz 
Published: April 2018

AbstractC−H activation bears great potential for enabling sustainable molecular syntheses in a step‐ and atom‐economical manner, with major advances having been realized with precious 4d and 5d transition metals. In contrast, we employed earth abundant, nontoxic iron catalysts for versatile allene annulations through a unique C−H/N−H/C−O/C−H functionalization sequence. The powerful iron catalysis occurred under external‐oxidant‐free conditions even at room temperature, while detailed mechanistic studies revealed an unprecedented 1,4‐iron migration regime for facile C−H activations.
In Situ Generation of Silylzinc by Si−B Bond Activation Enabling Silylzincation and Silaboration of Terminal Alkynes
Authors: Nagashima Yuki , Yukimori Daiki , Wang Chao , Uchiyama Masanobu 
Published: April 2018

AbstractA new protocol has been designed for the in situ generation of unstable Si−Zn species through the reaction of dialkylzinc, phosphine, and silylborane (Si−B). Successive reactions with various terminal alkynes using this protocol enabled highly controllable regio‐/stereo‐/chemoselective silylzincation and silaboration on demand without the need for a transition‐metal catalyst.
Directional Shuttling of a Stimuli‐Responsive Cone‐Like Macrocycle on a Single‐State Symmetric Dumbbell Axle
Authors: Cui Jie‐Shun , Ba Qian‐Kai , Ke Hua , Valkonen Arto , Rissanen Kari , Jiang Wei 
Published: April 2018

AbstractRotaxane‐based molecular shuttles are often operated using low‐symmetry axles and changing the states of the binding stations. A molecular shuttle capable of directional shuttling of an acid‐responsive cone‐like macrocycle on a single‐state symmetric dumbbell axle is now presented. The axle contains three binding stations: one symmetric di(quaternary ammonium) station and two nonsymmetric phenyl triazole stations arranged in opposite orientations. Upon addition of an acid, the protonated macrocycle shuttles from the di(quaternary ammonium) station to the phenyl triazole binding station closer to its butyl groups. This directional shuttling presumably originates from charge repulsion and an orientational binding preference between the cone‐like cavity and the nonsymmetric phenyl triazole station. This mechanism for achieving directional shuttling by manipulating only the wheels instead of the tracks is new for artificial molecular machines.
Unmanned Aerial Vehicles Formation Using Learning Based Model Predictive Control
Authors: Hafez Ahmed T. , Givigi Sidney N. , Yousefi Shahram 
Published: April 2018

AbstractThis paper presents a solution for the formation flight problem for multiple unmanned aerial vehicles (UAVs) cooperating to execute a required mission. Learning Based Model Predictive Control (LBMPC) is implemented on the team of UAVs in order to accomplish the required formation. All flight simulations respect Reynold's rules of flocking to avoid UAV collisions with nearby flockmates, match the team members velocity and stay close to each other during the formation. The main contribution of this paper lies in the application of LBMPC to solve the problem of formation for an autonomous team of UAVs. The proposed solution is theoretically, by the application of analysis to the problem, demonstrated to be stable. Moreover, simulations support the findings of the paper. The main contributions of this paper are the proposed LBMPC formulation for formation of vehicles with uncertainty in their models, and the theoretical analysis of the solution.
Web‐mediated problem‐based learning and computer programming: Effects of thinking style on academic achievement and attitude
Authors: Yağcı Mustafa 
Published: April 2018

AbstractThe present study aims to investigate the effect of the thinking styles on students’ attitudes toward problem based learning, web based learning and academic achievement within an online problem‐based learning environment. In this study, a single‐factor, pre‐test post‐test single group and semi empirical pattern was utilized. The study was conducted on 41 students from a public university in Turkey. To implement problem‐based learning activities, a teaching environment was designed with the Moodle platform, allowing for group work and discussions. Six status of the problems were prepared exclusively for the 10‐week application period so that students could make suggestions about how to solve them. In the data collection phase, the Scale of Thinking Styles, the Attitude toward Problem Based Learning Scale, the Attitude toward Web Based Learning Scale, and the Academic Achievement Test were employed. T‐test and covariance analyses were carried out in the statistical analysis phase. According to the findings of the present study, the Elaborator, and the Extrovert students have a more positive view of problem based learning than the Integrator and the Introvert students. Furthermore, the Elaborator and the Innovative students have a more positive view of web based learning than the Integrator and the Traditionalist students. Moreover, it was determined that the Elaborator and the Innovative students were more successful than the Integrator and the Traditionalist students. As a result, students’ thinking styles are related to attitude and academic achievement.
Anaerobic Radical Enzymes for Biotechnology
Authors: Jäger Christof M. , Croft Anna K. 
Published: April 2018

AbstractEnzymes that proceed through radical intermediates have a rich chemistry that includes functionalization of otherwise unreactive carbon atoms, carbon‐skeleton rearrangements, aromatic reductions, and unusual eliminations. Especially under anaerobic conditions, organisms have developed a wide range of approaches for managing these transformations that can be exploited to generate new biological routes towards both bulk and specialty chemicals. These routes are often either much more direct or allow access to molecules that are inaccessible through standard (bio)chemical approaches. This review gives an overview of some of the key enzymes in this area: benzoyl‐CoA reductases effecting the enzymatic Birch reduction, ketyl radical dehydratases, coenzyme B12‐dependent enzymes, glycyl radical enzymes, and radical SAM (AdoMet radical) enzymes. These enzymes are discussed alongside biotechnological applications, highlighting the wide range of actual and potential uses. With the increased diversity in biotechnological approaches to obtaining these enzymes and information about them, even more of these enzymes can be expected to find application in industrial processes.
DL‐3‐n‐butylphthalide promotes dendrite development in cortical neurons subjected to oxygen‐glucose deprivation/reperfusion
Authors: Zhang Peng , Xu Ruxiang , Guo Yang , Qin Jiazhen , Dai Yiwu , Liu Ning , Wu Cuiying 
Published: April 2018

AbstractThe limited degree of functional recovery is closely associated with the condition of the periinfarct cortex after ischemic stroke. The model of oxygen‐glucose deprivation in cultured neurons could partly simulate this condition. Proper dendritic morphology is crucial for the correct wiring of neuronal function. Hence, the question of how to facilitate the plasticity of neural dendrites is of great significance. DL‐3‐n‐butylphthalide is an efficient medication for ischemic stroke. In this study, in addition to having neuroprotective effects, DL‐3‐n‐butylphthalide could increase the number of primary and secondary dendrites and of dendritic tips as confirmed by Sholl analysis. This study further demonstrated that DL‐NBP inactivates PI3K/AKT signaling to positively regulate dendritic branching.
Exchange Interactions Switch Tunneling: A Comparative Experimental and Theoretical Study on Relaxation Dynamics by Targeted Metal Ion Replacement
Authors: Tian Haiquan , Ungur Liviu , Zhao Lang , Ding Shuai , Tang Jinkui , Chibotaru Liviu F. 
Published: April 2018

AbstractThe magnetic relaxation and magnetization blocking barriers of tailor‐made homo‐ and heterodinuclear compounds [Dy2(opch)2(OAc)2(H2O)2]⋅MeOH (1) and [DyMn(opch)2(OAc)(MeOH)(H2O)2] (2), where H2opch is (E)‐N′‐(2‐hydroxy‐3‐methoxybenzylidene)pyrazine‐2‐carbohydrazide, were systematically investigated and the change in single‐molecule magnet behavior originating from targeted replacement of one dysprosium site in the Dy2 compound with manganese was elucidated through a combination of experimental and theoretical studies. A detailed comparative study on these closely related model compounds revealed remarkable changes of the crystal‐field splitting and anisotropy of the Dy site and the total exchange spectrum due to the replacement of Dy by Mn. The blocking barriers of these two compounds, which explain their different relaxation behaviors, were analyzed. The two Ising doublets arising from the magnetic interaction in the case of 1 are strongly uniaxial, with tunneling splittings smaller than 10−6 cm−1, and this leads to magnetic relaxation at temperatures exceeding the exchange energy (2.14 cm−1), which involves transition via the excited states corresponding to local transitions on the excited doublet at the Dy site. The third and fourth exchange doublets in 2 (located at 2.16 and 3.25 cm−1, respectively) show much larger tunneling splittings (of 10−4 and 10−3 cm−1, respectively), and thus open an important path for magnetic relaxation.