bluuebunny/crossref_metadata_2025_split huggingface dataset:
Deadlock Control for a Class of Generalized Petri Nets Based on Proper Resource Allocation
Authors: Hou YiFan , Zhao Mi , Liu Ding 
Published: October 2014

AbstractThis article develops a deadlock prevention policy for a class of generalized Petri nets, namely G‐systems, which can model flexible manufacturing systems with machining, assembly, and disassembly operations. In this research, a polynomial complexity control policy for non‐blocking supervisors is established by properly adjusting resource allocation. First, a set of linear inequality constraints is derived with respect to different resource requirements such that the allocation of the system resources to various requesting processes can be appropriately restricted, that is, the resulting system has no deadlock state by imposing monitors on operation places. Moreover, an algorithm is proposed to identify the redundant constraints such that structurally simple liveness‐enforcing net supervisors can be obtained. Compared with existing polices, the proposed method can usually lead to a suboptimal supervisor with high computational efficiency. Finally, a flexible manufacturing system example is utilized to demonstrate the proposed method.
Absorption, distribution, metabolism and excretion of novel phosphodiesterase type 4 inhibitor ASP3258 in rats
Authors: Ohtsu Yoshiaki , Sonoda Takuya , Susaki Yoko , Tohda Toshifumi , Fukunaga Yasuhisa , Iwatsubo Takafumi , Noguchi Kiyoshi 
Published: October 2014

AbstractThe potent and selective phosphodiesterase 4 inhibitor ASP3258 is a novel therapeutic agent for asthma and chronic obstructive pulmonary disease (COPD). After a single oral administration to rats, ASP3258 is rapidly absorbed with a bioavailability of 106%. In situ absorption data indicated that ASP3258 is mainly absorbed in the small intestine. Tissue distribution data after oral administration of 14C‐ASP3258 showed rapid and extensive distribution to various tissues. Excluding the gastrointestinal tract, the tissues with the highest concentrations were liver, heart and plasma. Liquid chromatography‐nuclear magnetic resonance spectroscopy data revealed that O‐glucuronidation of the carboxylic acid moiety of ASP3258 (formation of an acyl glucuronide) plays a key role in metabolism. No indication was found that the acyl glucuronide reacted with proteins in plasma or tissues. When 14C‐ASP3258 was orally administered to intact rats, urinary and fecal excretion accounted for 1.3% and 100.6% of the administered radioactivity, respectively. After a single oral administration of 14C‐ASP3258 to bile‐cannulated rats, urinary and biliary excretion accounted for 0.7% and 93.8% of the administered radioactivity, respectively. These findings suggest that fecal excretion via bile plays an important role in the elimination of ASP3258‐derived radioactivity. In vitro metabolic profiles were relatively similar among the species examined, suggesting that our findings in rats may help us to understand pharmacokinetics, efficacy and safety profiles in humans and other species. Copyright © 2014 John Wiley & Sons, Ltd.
Silver Corrole Complexes: Unusual Oxidation States and Near‐IR‐Absorbing Dyes
Authors: Sinha Woormileela , Sommer Michael G. , Deibel Naina , Ehret Fabien , Sarkar Biprajit , Kar Sanjib 
Published: October 2014

AbstractMacrocycles such as porphyrins and corroles have important functions in chemistry and biology, including light absorption for photosynthesis. Generation of near‐IR (NIR)‐absorbing dyes based on metal complexes of these macrocycles for mimicking natural photosynthesis still remains a challenging task. Herein, the syntheses of four new AgIII corrolato complexes with differently substituted corrolato ligands are presented. A combination of structural, electrochemical, UV/Vis/NIR‐EPR spectroelectrochemical, and DFT studies was used to decipher the geometric and electronic properties of these complexes in their various redox states. This combined approach established the neutral compounds as stable AgIII complexes, and the one‐electron reduced species of all the compounds as unusual, stable AgII complexes. The one‐electron oxidized forms of two of the complexes display absorptions in the NIR region, and thus they are rare examples of mononuclear complexes of corroles that absorb in the NIR region. The appearance of this NIR band, which has mixed intraligand charge transfer/intraligand character, is strongly dependent on the substituents of the corrole rings. Hence, the present work revolves round the design principles for the generation of corrole‐based NIR‐absorbing dyes and shows the potential of corroles for stabilizing unusual metal oxidation states. These findings thus further contribute to the generation of functional metal complexes based on such macrocyclic ligands.
Mapping of the Modular Closthioamide Architecture Reveals Crucial Motifs of Polythioamide Antibiotics
Authors: Kloss Florian , Chiriac Alina Iulia , Hertweck Christian 
Published: October 2014

AbstractClosthioamide, the first known secondary metabolite from an anaerobic microorganism (Clostridium cellulolyticum), represents a highly potent antibiotic that is active against methicillin‐resistant Staphylococcus aureus (MRSA) and vancomycin‐resistant Enterococcus faecalis (VRE) at nanomolar concentrations. To unveil structure–activity relationships of the unusual polythioamide natural product we have designed a synthetic grid to access analogues with altered terminal aromatic moieties, diverse p‐phenyl substituents, different types and sizes of aliphatic spacers, varying numbers of thioamide residues, and diverse sizes and symmetries of the poly‐β‐thioalanyl backbone. A library of 28 closthioamide analogues was tested against a panel of human pathogenic bacteria. We found that aromatic terminal groups, the defined length of the spacer groups, the presence of all six thioamide residues and the modular arrangement of the β‐thioalanyl units play essential roles for the antibiotic activity of closthioamide, yet there is a degree of freedom in the symmetry of the molecule. This study yields the first insights into pivotal structural motifs and the structural space of this new family of antibiotics, a prerequisite for the development of these promising antibiotics.
A Direct Hybridization between Isocharged Nanosheets of Layered Metal Oxide and Graphene through a Surface‐Modification Assembly Process
Authors: Adpakpang Kanyaporn , Oh Seung Mi , Jin Xiaoyan , Hwang Seong‐Ju 
Published: October 2014

AbstractAn efficient and universal method to directly hybridize isocharged nanosheets of layered metal oxide and reduced graphene oxide (rGO) is developed on the basis of the surface modification and an electrostatically driven assembly process. On the basis of this synthetic method, the CoO2–rGO nanocomposite can be synthesized with exfoliated CoO2 and rGO nanosheets, and transformed into CoO–CoO2–rGO nanocomposites with excellent electrode performance for lithium‐ion batteries. Also, this surface‐modification assembly route is successfully applied for the synthesis of another mesoporous TiO2–rGO nanocomposite. This result provides clear evidence for the usefulness of the present method as a universal way of hybridizing isocharged anionic nanosheets of inorganic solids and graphene.
Binding of Scandium Ions to Metalloporphyrin–Flavin Complexes for Long‐Lived Charge Separation
Authors: Kojima Takahiko , Kobayashi Ryosuke , Ishizuka Tomoya , Yamakawa Shinya , Kotani Hiroaki , Nakanishi Tatsuaki , Ohkubo Kei , Shiota Yoshihito , Yoshizawa Kazunari , Fukuzumi Shunichi 
Published: October 2014

AbstractA porphyrin–flavin‐linked dyad and its zinc and palladium complexes (MPorFl: 2M, M=2 H, Zn, and Pd) were newly synthesized and the X‐ray crystal structure of 2Pd was determined. The photodynamics of 2M were examined by femto‐ and nanosecond laser flash photolysis measurements. Photoinduced electron transfer (ET) in 2H2 occurred from the singlet excited state of the porphyrin moiety (H2Por) to the flavin (Fl) moiety to produce the singlet charge‐separated (CS) state 1(H2Por.+Fl.−), which decayed through back ET (BET) to form 3[H2Por]*Fl with rate constants of 1.2×1010 and 1.2×109 s−1, respectively. Similarly, photoinduced ET in 2Pd afforded the singlet CS state, which decayed through BET to form 3[PdPor]*Fl with rate constants of 2.1×1011 and 6.0×1010 s−1, respectively. The rate constant of photoinduced ET and BET of 2M were related to the ET and BET driving forces by using the Marcus theory of ET. One and two Sc3+ ions bind to the flavin moiety to form the FlSc3+ and Fl(Sc3+)2 complexes with binding constants of K1=2.2×105 M−1 and K2=1.8×103 M−1, respectively. Other metal ions, such as Y3+, Zn2+, and Mg2+, form only 1:1 complexes with flavin. In contrast to 2M and the 1:1 complexes with metal ions, which afforded the short‐lived singlet CS state, photoinduced ET in 2Pd⋅⋅⋅Sc3+ complexes afforded the triplet CS state (3[PdPor.+Fl.−(Sc3+)2]), which exhibited a remarkably long lifetime of τ=110 ms (kBET=9.1 s−1).
Breaking the Odd–Even Effect in the Self‐Assembly of Linear Bis(benzamides)
Authors: Aparicio Fátima , Matesanz Emilio , Sánchez Luis 
Published: October 2014

AbstractThe twisting of supramolecular aggregates formed from simple linear bis(benzamides) has been investigated. The antiparallel arrangement of the amide functional groups controls the generation of twisted supramolecular structures. The results presented herein could contribute to elaborate predictive tools applicable in the generation of chiral supramolecular structures.
Regarding Initial Ring Opening of Propylene Oxide in its Copolymerization with CO2 Catalyzed by a Cobalt(III) Porphyrin Complex
Authors: Xia Wei , Vagin Sergei I. , Rieger Bernhard 
Published: October 2014

AbstractCobalt(III) tetraphenylporphyrin chloride (TPPCoCl) was experimentally proved to be an active catalyst for poly(propylene carbonate) production. It was chosen as a model catalyst in the present work to investigate the initiation step of propylene oxide (PO)/CO2 copolymerization, which is supposed to be the ring opening of the epoxide. Ring‐opening intermediates (1–7) were detected by using 1H NMR spectroscopy. A first‐order reaction in TPPCoCl was determined. A combination of monometallic and bimetallic ring‐opening pathways is proposed according to kinetics experiments. Addition of onium salts (e.g., bis(triphenylphosphine)iminium chloride, PPNCl) efficiently promoted the PO ring‐opening rate. The existence of axial ligand exchange in the cobalt porphyrin complex in the presence of onium salts was suggested by analyzing collected 1H NMR spectra.
A Universal Approach for the Reversible Phase Transfer of Hydrophilic Nanoparticles
Authors: Ma Shenghua , Yong Daming , Zhang Ying , Wang Xuejing , Han Xiaojun 
Published: October 2014

AbstractThe ability to engineer the surface properties of magnetic nanoparticles is important for their various applications, as numerous physical and chemical properties of nanoscale materials are seriously affected by the chemical constitution of their surfaces. For some specific applications, nanoparticles need to be transferred from a polar to a nonpolar environment (or vice versa) after synthesis. In this work we have developed a universal method for the phase transfer of magnetic nanoparticles that preserves their shape and size. Octadecyltrimethoxysilane was used to cap the surfaces of the aqueous magnetic nanoparticles, thereby allowing their transfer into nonpolar solution. The resulting hydrophobic magnetic nanoparticles were transferred back into aqueous solution by subsequently covering them with an egg‐PC lipid monolayer. The superparamagnetic properties of the particles were retained after the phase transfer. The maximum transfer yields are dependent on their particle size with a maximum value of 93.16±4.75 % for magnetic nanoparticles with a diameter of 100 nm. The lipid‐modified magnetic particles were stable over 1 week, and thus they have potential applications in the field of biomedicine. This work also provides a facile strategy for the controllable engineering of the surface properties of nanoparticles.
Selective Catalytic Behavior of a Phosphine‐Tagged Metal‐Organic Framework Organocatalyst
Authors: Xu Xiaoying , Rummelt Stephan M. , Morel Flavien L. , Ranocchiari Marco , van Bokhoven Jeroen A. 
Published: October 2014

AbstractSteric hindrance by a metal–organic framework (MOF) is shown to influence the outcome of a catalytic reaction by controlling the orientation of its intermediates. This is demonstrated using an organocatalyst, phosphine MOF LSK‐3, which is evaluated with the aid of molecular modeling and NMR spectroscopy techniques. This report is the first application of phosphine MOFs in organocatalysis and explores the potential of a framework steric hindrance to impose selectivity on a catalytic reaction. These findings expand the opportunities for control and design of the active site in the pocket of heterogeneous catalysts.
Ligand‐Controlled Regiodivergent Pathways of Rhodium(III)‐Catalyzed Dihydroisoquinolone Synthesis: Experimental and Computational Studies of Different Cyclopentadienyl Ligands
Authors: Wodrich Matthew D. , Ye Baihua , Gonthier Jérôme F. , Corminboeuf Clémence , Cramer Nicolai 
Published: October 2014

AbstractRhIII‐catalyzed directed CH functionalizations of arylhydroxamates have become a valuable synthetic tool. To date, the regioselectivity of the insertion of the unsaturated acceptor into the common cyclometalated intermediate was dependent solely on intrinsic substrate control. Herein, we report two different catalytic systems that allow the selective formation of regioisomeric 3‐aryl dihydroisoquinolones and previously inaccessible 4‐aryl dihydroisoquinolones under full catalyst control. The differences in the catalysts are computationally examined using density functional theory and transition state theory of different possible pathways to elucidate key contributing factors leading to the regioisomeric products. The stabilities of the initially formed rhodium complex styrene adducts, as well as activation barrier differences for the migratory insertion, were identified as key contributing factors for the regiodivergent pathways.
Carbon‐Centered Radical Addition to OC of Amides or Esters as a Route to CO Bond Formations
Authors: Liu Dong , Tang Shan , Yi Hong , Liu Chao , Qi Xiaotian , Lan Yu , Lei Aiwen 
Published: October 2014

AbstractAmong various types of radical reactions, the addition of carbon radicals to unsaturated bonds is a powerful tool for constructing new chemical bonds, in which the typical applied unsaturated substrates include alkenes, alkynes and imines. Carbonyl is perhaps the most common unsaturated group in nature. This work demonstrates a novel CO bond formation through carbon‐centered radical addition to the carbonyl oxygen of amide or ester, in which amide and ester groups are easily activated through the radical process. EPR spectroscopy and radical clock experiments support the radical process for this transformation, and density functional theory (DFT) calculations support the possibility of carbon‐centered radical addition to the carbonyl oxygen of amides or esters.
Rapid Synthesis of Hollow Ag–Au Nanodendrites in 15 Seconds by Combining Galvanic Replacement and Precursor Reduction Reactions
Authors: da Silva Anderson G. M. , de Souza Michele L. , Rodrigues Thenner S. , Alves Rafael S. , Temperini Marcia L. A. , Camargo Pedro H. C. 
Published: October 2014

AbstractMetallic nanomaterials displaying hollow interiors as well as sharp tips/branches at their surface (such as hollow nanodendrites) are attractive, because these features enable higher surface‐to‐volume ratios than their solid and/or rounded counterparts. This paper describes a simple strategy for the synthesis of Ag–Au nanodendrites in 15 s using Ag nanospheres prepared in a previous synthetic step as seeds. Our approach was based on the utilization of Ag nanospheres as seeds for Au deposition by a combination of galvanic replacement reaction between Ag and AuCl4−(aq) and AuCl4−(aq) reduction using hydroquinone in the presence of polyvinylpyrrolidone (PVP) as a stabilizer and water as the solvent. The produced Ag–Au nanodendrites presented monodisperse sizes, and their surface morphologies could be tuned as a function of growth time. Owing to their hollow interiors and sharp tips, the Ag–Au nanodendrites performed as effective substrates for surface‐enhanced Raman scattering (SERS) detection of 4‐MPy (4‐mercaptopyridine) and R6G (rhodamine 6G) as probe molecules. We believe that the approach described herein can serve as a protocol for the fast and one‐step synthesis of Ag–Au hollow nanondendrites with a wide range of sizes, compositions, and surface morphologies for applications in SERS and catalysis.
Polyimido Sulfur(VI) Phosphanyl Ligand in Metal Complexation
Authors: Carl Elena , Stalke Dietmar 
Published: October 2014

AbstractHerein, new complexes containing the [Ph2PCH2S(NtBu)3]− anion are presented, supplying three imido nitrogen atoms and a remote phosphorus atom as potential donor sites to main group and transition‐metal cations. The lithiated complex [(tmeda)Li{(NtBu)3SCH2PPh2}] (1) is an excellent starting material in transmetalation reactions. Herein, the transition‐metal complexes [M{(NtBu)3SCH2PPh2}2] (M=Mn (2), Ni (3), Zn (4)) were synthesized and structurally characterized. Their isotypical molecules show SN2 chelation and no employment of the adjacent phosphorus atom in coordination. The third pendent imido group is always twisted toward the vacant face of the tetrahedrally coordinated sulfur atom.
Performance of optimized link state routing protocol for video streaming application in vehicular ad‐hoc networks cloud computing
Authors: Ikeda Makoto , Honda Taiki , Barolli Leonard 
Published: October 2014

SummaryIn recent years, vehicular ad‐hoc networks (VANETs) have emerged as a unique type of mobile ad‐hoc networks. VANETs are an important component of the intelligent transportation systems. They can been utilized to guarantee road safety, avoid potential accidents and create new forms of inter‐vehicle communications. In this paper, we consider a network‐as‐a‐service architecture for VANET cloud computing. We investigate the performance of optimized link state routing protocol for video streaming application. The simulations are conducted in urban environment in three scenarios, where roadside access points (AP) are present and not present, with and without buildings. We consider 802.11p standard and send multiple video streaming flows over user diagram protocol. We use throughput, delay and jitter as evaluation metrics. Based on simulation results, we noticed that transmission for streaming is improved when roadside AP are used. Copyright © 2014 John Wiley & Sons, Ltd.
Reduced Graphene Oxide Nanosheets Decorated with Au Nanoparticles as an Effective Bactericide: Investigation of Biocompatibility and Leakage of Sugars and Proteins
Authors: Hussain Najrul , Gogoi Animesh , Sarma Rupak K. , Sharma Ponchami , Barras Alexandre , Boukherroub Rabah , Saikia Ratul , Sengupta Pinaki , Das Manash R. 
Published: October 2014

AbstractThis article reports the synthesis of a composite of reduced graphene oxide nanosheets decorated with gold nanoparticles (AuNPs‐rGO) through an ecofriendly route, and the investigation of its biocompatibility to HeLa cells and its antibacterial activity against Gram‐positive and Gram‐negative bacteria. The composite material is synthesized by using an environmentally friendly reducing agent, ascorbic acid, under ultrasonication. The composite material is characterized by UV/Vis spectroscopy, X‐ray photoelectron spectroscopy (XPS), X‐ray diffraction (XRD), small‐angle X‐ray scattering (SAXS), high‐resolution transmission electron microscopy (HRTEM), and thermogravimetric analysis (TGA). HRTEM analysis reveals the formation of spherical Au NPs of 8–45 nm in size on the folded rGO nanosheets, which is further confirmed by XRD and SAXS analyses. The AuNPs‐rGO shows good biocompatibility with cervix carcinoma, human (HeLa) cells, and possesses high antibacterial activity against two Gram‐positive bacteria (Staphylococcus aureus and Bacillus subtilis) and two Gram‐negative bacteria (Escherichia coli and Pseudomonous aeruginosa). The bacterial cell death is caused by the leakage of sugars and proteins from the cell membrane in contact with the AuNPs‐rGO composite material.
Characteristics of traps in Tl2Ga2Se3S single crystals by low‐temperature thermoluminescence measurements
Authors: Delice S. , Gasanly N.M. 
Published: October 2014

Defect characterization of Tl2Ga2Se3S single crystals has been performed by thermoluminescence (TL) measurements at low temperatures between 10 and 70 K with various heating rate ranging from 0.6 to 1.0 K/s. The TL signal due to the luminescence from trap centers revealed one glow peak having maximum temperature of 36 K. Curve fitting and various heating rate methods were used for the analysis of the glow curve. The activation energy of 13 meV was found by the application of curve fitting method. This practical method also established that the trap center exhibits the characteristics of mixed (general) kinetic order. In addition, various heating rate analysis gave a compatible result (13 meV) with curve fitting as the temperature lag effect was taken into consideration. Distribution of traps was also investigated using an experimental method. A quasi‐continuous distribution was attributed to the determined trap centers.
The epigenetic factor Kmt2a/Mll1 regulates neural progenitor proliferation and neuronal and glial differentiation
Authors: Huang Yin‐Cheng , Shih Hung‐Yu , Lin Sheng‐Jia , Chiu Ching‐Chi , Ma Tsu‐Lin , Yeh Tu‐Hsueh , Cheng Yi‐Chuan 
Published: October 2014

ABSTRACTMultiple epigenetic factors play a critical role in cell proliferation and differentiation. However, their function in embryogenesis, especially in neural development, is currently unclear. The Trithorax group (TrxG) homolog KMT2A (MLL1) is an important epigenetic regulator during development and has an especially well‐defined role in hematopoiesis. Translocation and aberrant expression of KMT2A is often observed in many tumors, indicating its proto‐oncogenic character. Here, we show that Kmt2a was essential for neural development in zebrafish embryos. Disrupting the expression of Kmt2a using morpholino antisense oligonucleotides and a dominant‐negative variant resulted in neurogenic phenotypes, including downregulated proliferation of neural progenitors, premature differentiation of neurons, and impaired gliogenesis. This study therefore revealed a novel function of Kmt2a in cell proliferation and differentiation, providing further insight into the function of TrxG proteins in neural development and brain tumors. © 2014 Wiley Periodicals, Inc. Develop Neurobiol 75: 452–462, 2015
Community assembly rules affect the diversity of expanding communities
Authors: Peng Zechen , Zhou Shurong 
Published: October 2014

AbstractDespite centuries of interest in species range limits, few studies have taken a whole community into consideration. Actually, multiple species may simultaneously respond to environmental changes, for example, global warming, leading a series of dynamical communities toward the advancing front. We investigated multiple species range expansions through the analysis of a two‐species dispersion model and simulations of multiple species assemblages regulated by neutral and fecundity–survival trade‐offs (FSTs), respectively, and found that species assemblages regulated by different mechanisms would initiate different expanding patterns in geographic ranges in response to environmental changes. The neutral model generally predicts a higher biodiversity near the core of an expanding range, and a lower community similarity compared with a FST model. Without considering the evolution of life history traits, an assortment of the reproduction ability happens at the advancing front under FSTs at the expense of a higher death rate or lower competitive ability. These results emphasize the importance of community assembly rules to the biodiversity maintenance of range expanding communities.