bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fluorescent Gold Nanoclusters with Interlocked Staples and a Fully Thiolate‐Bound Kernel
Authors: Gan Zibao , Lin Yuejian , Luo Lun , Han Guangmei , Liu Wei , Liu Zhengjie , Yao Chuanhao , Weng Linhong , Liao Lingwen , Chen Jishi , Liu Xu , Luo Yi , Wang Chengming , Wei Shiqiang , Wu Zhikun 
Published: August 2016

AbstractThe structural features that render gold nanoclusters intrinsically fluorescent are currently not well understood. To address this issue, highly fluorescent gold nanoclusters have to be synthesized, and their structures must be determined. We herein report the synthesis of three fluorescent Au24(SR)20 nanoclusters (R=C2H4Ph, CH2Ph, or CH2C6H4tBu). According to UV/Vis/NIR, differential pulse voltammetry (DPV), and X‐ray absorption fine structure (XAFS) analysis, these three nanoclusters adopt similar structures that feature a bi‐tetrahedral Au8 kernel protected by four tetrameric Au4(SR)5 motifs. At least two structural features are responsible for the unusual fluorescence of the Au24(SR)20 nanoclusters: Two pairs of interlocked Au4(SR)5 staples reduce the vibration loss, and the interactions between the kernel and the thiolate motifs enhance electron transfer from the ligand to the kernel moiety through the Au−S bonds, thereby enhancing the fluorescence. This work provides some clarification of the structure–fluorescence relationship of such clusters.
Formation of CoS2 Nanobubble Hollow Prisms for Highly Reversible Lithium Storage
Authors: Yu Le , Yang Jing Fan , Lou Xiong Wen (David) 
Published: August 2016

AbstractMetal–organic frameworks (MOFs) have been intensively used as the templates/precursors to synthesize complex hollow structures for various energy‐related applications. Herein we report a facile two‐step diffusion‐controlled strategy to generate novel MOFs derived hierarchical hollow prisms composed of Nanosized CoS2 bubble‐like subunits. Uniform zeolitic imidazolate framework‐67 (ZIF‐67) hollow prisms assembled by interconnected nanopolyhedra are first synthesized via a transformation process. Afterwards, these ZIF‐67 building blocks are converted into CoS2 bubble‐like hollow particles to form the complex hollow prisms through a sulfidation reaction with an additional annealing treatment. When evaluated as an electrode material for lithium‐ion batteries, the as‐obtained CoS2 nanobubble hollow prisms show remarkable electrochemical performance with good rate capability and long cycle life.
A One‐Pot Chemically Cleavable Bis‐Linker Tether Strategy for the Synthesis of Heterodimeric Peptides
Authors: Patil Nitin A. , Tailhades Julien , Karas John A. , Separovic Frances , Wade John D. , Hossain Mohammed Akhter 
Published: August 2016

AbstractHeterodimeric peptides linked by disulfide bonds are attractive drug targets. However, their chemical assembly can be tedious, time‐consuming, and low yielding. Inspired by the cellular synthesis of pro‐insulin in which the two constituent peptide chains are expressed as a single‐chain precursor separated by a connecting C‐peptide, we have developed a novel chemically cleavable bis‐linker tether which allows the convenient assembly of two peptide chains as a single “pro”‐peptide on the same solid support. Following the peptide cleavage and post‐synthetic modifications, this bis‐linker tether can be removed in one‐step by chemical means. This method was used to synthesize a drug delivery‐cargo conjugate, TAT‐PKCi peptide, and a two‐disulfide bridged heterodimeric peptide, thionin (7‐19)‐(24‐32R), a thionin analogue. To our knowledge, this is the first report of a one‐pot chemically cleavable bis‐linker strategy for the facile synthesis of cross‐bridged two‐chain peptides.
Bifunctional‐Phosphine‐Catalyzed Sequential Annulations of Allenoates and Ketimines: Construction of Functionalized Poly‐heterocycle Rings
Authors: Li Erqing , Jin Hongxing , Jia Penghao , Dong Xuelin , Huang You 
Published: August 2016

AbstractA highly stereoselective sequential annulation reaction between γ‐substituted allenoates and ketimines was reported. By using bifunctional N‐acyl aminophosphine catalysts, poly‐heterocycle rings were obtained with high stereocontrol in good to excellent yields. The desired products have four contiguous stereogenic centers (one quaternary and three tertiary carbon centers), and only one isomer was obtained in all reactions.
Ground‐State Chemical Reactivity under Vibrational Coupling to the Vacuum Electromagnetic Field
Authors: Thomas Anoop , George Jino , Shalabney Atef , Dryzhakov Marian , Varma Sreejith J. , Moran Joseph , Chervy Thibault , Zhong Xiaolan , Devaux Eloïse , Genet Cyriaque , Hutchison James A. , Ebbesen Thomas W. 
Published: August 2016

AbstractThe ground‐state deprotection of a simple alkynylsilane is studied under vibrational strong coupling to the zero‐point fluctuations, or vacuum electromagnetic field, of a resonant IR microfluidic cavity. The reaction rate decreased by a factor of up to 5.5 when the Si−C vibrational stretching modes of the reactant were strongly coupled. The relative change in the reaction rate under strong coupling depends on the Rabi splitting energy. Product analysis by GC‐MS confirmed the kinetic results. Temperature dependence shows that the activation enthalpy and entropy change significantly, suggesting that the transition state is modified from an associative to a dissociative type. These findings show that vibrational strong coupling provides a powerful approach for modifying and controlling chemical landscapes and for understanding reaction mechanisms.
A Family of Multiply Bonded Dimolybdenum Boraamidinates with the Formal Mo−Mo Bond Orders of 3, 4, 4.5, and 5
Authors: Lu Duan‐Yen , Kuo Ting‐Shen , Tsai Yi‐Chou 
Published: August 2016

AbstractA boraamidinato ligand [PhB(N‐2,6‐iPr2C6H3)2]2− was employed to stabilize a new family of multiply bonded dimolybdenum complexes [MoCl(μ‐κ2‐PhB(N‐2,6‐iPr2C6H3)2)]2 (4) and [Mo(μ‐κ2‐PhB(N‐2,6‐iPr2C6H3)2)]2n− (n=0 (5), 1 (6), 2 (7)), with the respective formal Mo−Mo bond orders of 3, 4, 4.5, and 5. Each metal center in 5–7 is two‐coordinate with respect to the ligands. Of particular interest is the quadruply bonded dimolybdenum complex 5, featuring an unprecedented angular conformation. The bent Mo2N4 core of 5 distorts toward planarity upon reduction. As a result, compound 7 features a planar Mo2N4 core, while that of 6 is still bent but less significantly than that of 5. Additionally, the Mo−Mo bond lengths of 4–7 systematically decrease as the valency of the central Mo2 units decreases. Complex 7 features the shortest Mo−Mo bond length (2.0106(5) Å) yet reported.
Direct Transformation of Molecular Dinitrogen into Ammonia Catalyzed by Cobalt Dinitrogen Complexes Bearing Anionic PNP Pincer Ligands
Authors: Kuriyama Shogo , Arashiba Kazuya , Tanaka Hiromasa , Matsuo Yuki , Nakajima Kazunari , Yoshizawa Kazunari , Nishibayashi Yoshiaki 
Published: August 2016

AbstractThe direct formation of ammonia from molecular dinitrogen under mild reaction conditions was achieved by using new cobalt dinitrogen complexes bearing an anionic PNP‐type pincer ligand. Up to 15.9 equivalents of ammonia were produced based on the amount of catalyst together with 1.0 equivalent of hydrazine (17.9 equiv of fixed nitrogen atoms).
Gold‐catalyzed Intermolecular Oxidations of 2‐Ketonyl‐1‐ethynyl Benzenes with N‐Hydoxyanilines to Yield 2‐Aminoindenones via Gold Carbene Intermediates
Authors: Mokar Bhanudas Dattatray , Huple Deepak B. , Liu Rai‐Shung 
Published: August 2016

AbstractGold‐catalyzed oxidations of 2‐ketonyl‐1‐ethynyl benzenes with N‐hydroxyanilines yield 2‐aminoindenone derivatives efficiently. Experimental data suggests that this process involves an α‐oxo gold carbene intermediate, generated from the attack of N‐hydroxyaniline on furylgold carbene intermediate, rather than the typical attack of oxidants on π‐alkynes.
Thermo‐rheological and interfacial properties of polylactic acid/polyethylene glycol blends toward the melt electrospinning ability
Authors: Nazari Tayebe , Garmabi Hamid 
Published: August 2016

ABSTRACTThe electrospinning ability of PLA/PEG system at the melt state was investigated through the viscoelastic parameters obtained from dynamic shear and extensional rheometers. PLA and PEG were melt‐blended at various composition ratios. Effect of PEG concentration on the PLA thermal behavior was studied by the differential scanning calorimetry (DSC). According to DSC and wide‐angle X‐ray diffraction, the PLA crystallinity increased and the crystalline structure became more completed (α‐crystal form) in the presence of PEG. Viscoelastic parameters such as zero‐shear viscosity and relaxation time as an indication of elasticity were obtained. The results revealed enhanced polymer chain mobility and disentanglement ought to plasticizing effect of PEG. The critical content of PEG about 20–30 wt % at which the solid–liquid phase separation occurred was in good agreement with the viscoelastic properties. Hence, more than 20% PEG the elasticity diminished and the melt strength became zero. The interfacial tension of the PLA and PEG estimated through the rheological and morphological parameters evidenced the good miscibility of PLA/PEG system at the melt electrospinnig temperature. While the high viscose samples (η0 > 1800 Pa/s) PLA and PLA/PEG (95/5) were not spinnable at the spinning temperature of 180 °C, blends containing 10–30% PEG were easily spun. The finest and continuous fiber mats were obtained by electrospinning of PLA/PEG (80/20) blend (df = 4.8 ± 0.8 μm). More than the critical concentration of PEG (Φ > 30%), lacking the elasticity suppressed the melt electro‐spinnability of PLA/PEG. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44120.
Reactive compatibilization of poly(methyl acrylate‐ran‐acrylonitrile)/poly(ethylene) blends through amine–anhydride coupling
Authors: Gill Amardeep , Marić Milan 
Published: August 2016

ABSTRACTMethyl acrylate/acrylonitrile copolymers (MA/AN) were reactively compatibilized as the dispersed phase into poly(ethylene) (PE) for potential hydrocarbon barrier materials. The MA/AN was made reactive by including p‐aminostyrene (PAS), yielding terpolymers (MA/AN/PAS) with pendant primary amine functionality (number average molecular weight
= 65–133 kg mol−1, dispersity (Đ)=1.83–2.53, molar composition of PAS in copolymer FPAS = 0.03–0.14, molar composition of AN = FAN = 0.27–0.52). The non‐functional MA/AN and amino functional MA/AN/PAS were each melt blended into PE that was grafted with maleic anhydride (PE‐g‐MAnn) at 200 °C at 70:30 wt % PE‐g‐MAnn:co/terpolymer. After extrusion, the dispersed phase particle size (volume to surface area diameter,
) was coarse (12.6 μm) for the non‐reactive blend whereas it was much lower for the reactive blend (
= 1.2 μm). Coarsening after annealing at 150 °C was slow, but the domain sizes increased only slightly for both cases. The reactive blend was deemed sufficiently stable and thus was suitable as a candidate barrier material for further testing against olefins. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44177.
Reactive compatibilization of poly(styrene‐ran‐acrylonitrile)/poly(ethylene) blends through the acid–epoxy reaction
Authors: Gill Amardeep , Hong Celestine , Gromadzki Daniel , Marić Milan 
Published: August 2016

ABSTRACTTwo families of acid functional styrene/acrylonitrile copolymers (SAN) for application as dispersed phase barrier materials in poly(ethylene) (PE) were studied. One type is SAN made by nitroxide mediated polymerization (NMP), which was subsequently chain extended with a styrene/tert‐butyl acrylate (S/tBA) mixture to provide a block copolymer (number average molecular weight Mn = 36.6 kg mol−1 and dispersity Đ = 1.34, after which the tert‐butyl protecting groups were converted to acid groups (SAN‐b‐S/AA). The other acid functional SAN is made by conventional radical terpolymerization (SAN‐AA). SAN‐AA and SAN‐b‐S/AA were each melt blended with PE grafted with epoxy functional glycidyl methacrylate (PE‐GMA) at 160 °C in a twin screw extruder (70:30 wt % PE‐GMA:SAN co/terpolymer). The non‐reactive PE‐g‐GMA/SAN blend had a volume to surface area diameter
= 3.0 μm while the reactive blends (via epoxy/acid coupling) (PE‐GMA/SAN‐b‐SAA and PE‐GMA/SAN‐AA) had
= 1.7 μm and 1.1 μm, respectively. After thermal annealing, the non‐reactive blend coarsened dramatically while the reactive blends showed little signs of coarsening, suggesting that the acid/epoxy coupling was effective for morphological stability. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 44178.
Quadratic stabilizability and H∞ control of linear discrete‐time stochastic uncertain systems
Authors: Jiang Xiushan , Tian Xuemin , Zhang Tianliang , Zhang Weihai 
Published: August 2016

AbstractThis paper considers quadratic stabilizability and H∞ feedback control for stochastic discrete‐time uncertain systems with state‐ and control‐dependent noise. Specifically, the uncertain parameters considered are norm‐bounded and external disturbance is an l2‐square summable stochastic process. Firstly, both quadratic stability and quadratic stabilization criteria are presented in the form of linear matrix inequalities (LMIs). Then we design the robust H∞ state and output feedback H∞ controllers such that the system with admissible uncertainties is not only quadratically internally stable but also robust H∞ controllable. Sufficient conditions for the existence of the desired robust H∞ controllers are obtained via LMIs. Finally, some examples are supplied to illustrate the effectiveness of our results.
Finite‐Time Sliding Mode Trajectory Tracking Control of Uncertain Mechanical Systems
Authors: Sun Liang , Zheng Zewei 
Published: August 2016

AbstractThe problem of finite‐time tracking control is studied for uncertain nonlinear mechanical systems. To achieve finite‐time convergence of tracking errors, a simple linear sliding surface based on polynomial reference trajectory is proposed to enable the trajectory tracking errors to converge to zero in a finite time, which is assigned arbitrarily in advance. The sliding mode control technique is employed in the development of the finite‐time controller to guarantee the excellent robustness of the closed‐loop system. The proposed sliding mode scheme eliminates the reaching phase problem, so that the closed‐loop system always holds the invariance property to parametric uncertainties and external disturbances. Lyapunov stability analysis is performed to show the global finite‐time convergence of the tracking errors. A numerical example of a rigid spacecraft attitude tracking problem demonstrates the effectiveness of the proposed controller.
Expression of cell cycle proteins in cortical neurons—Correlation with glutamate‐induced neurotoxicity
Authors: Negis Yesim , Karabay Arzu 
Published: August 2016

AbstractUnder physiological conditions, upon differentiation neurons become irreversibly post‐mitotic by down‐regulating cell cycle progression. However, recent studies have provided evidence that aberrant expression of cell cycle related proteins; especially cyclins, cyclin‐dependent kinases, and their inhibitors are accompanied by programmed cell death in neurons. This abnormal phenotype has been postulated to contribute to the pathophysiology of different neurodegenerative diseases. Glutamate is the most abundant and major excitatory neurotransmitter in the central nervous system but high concentrations are reported to be involved in the pathology of many neurodegenerative diseases. The mechanisms of glutamate neurotoxicity have been intensively investigated over the past decades but still remain not fully understood. In this study, we hypothesized that aberrant regulation of cell cycle proteins may be involved in glutamate‐induced neurotoxicity in primary cultures of rat cortical neurons. The results have shown that, glutamate treatment caused apoptosis by inducing active caspase‐3 and p53 expression. Together with this, an increase in cyclin D1 and Cdk4 protein levels, localization of cyclin D1 to nucleus, and a decrease in the cell cycle inhibitor p27 were observed. After glutamate treatment we also detected up‐regulation of protein kinase C‐α (PKC‐α) protein expression. Altogether, the data reported in this study show for the first time that glutamate in cortical neurons changes simultaneously the expression levels of a number of key cell cycle proteins and cell homeostasis regulators. © 2016 BioFactors, 42(4):358–367, 2016
CITA/NLRC5: A critical transcriptional regulator of MHC class I gene expression
Authors: Downs Isaac , Vijayan Saptha , Sidiq Tabasum , Kobayashi Koichi S. 
Published: August 2016

AbstractMajor histocompatibility complex (MHC) class I and class II molecules play essential roles in the development and activation of the human adaptive immune system. An NLR protein, CIITA (MHC class II transactivator) has been recognized as a master regulator of MHC class II gene expression, albeit knowledge about the regulatory mechanism of MHC class I gene expression had been limited. Recently identified MHC class I transactivator (CITA), or NLRC5, also belongs to the NLR protein family and constitutes a critical regulator for the transcriptional activation of MHC class I genes. In addition to MHC class I genes, CITA/NLRC5 induces the expression of β2‐microglobulin, TAP1 and LMP2, essential components of the MHC class I antigen presentation pathway. Therefore, CITA/NLRC5 and CIITA are transcriptional regulators that orchestrate the concerted expression of critical components in the MHC class I and class II pathways, respectively. © 2016 BioFactors, 42(4):349–357, 2016
Neferine prevents NF‐κB translocation and protects muscle cells from oxidative stress and apoptosis induced by hypoxia
Authors: Baskaran Rathinasamy , Poornima Paramasivan , Huang Chih Yang , Padma Viswanadha Vijaya 
Published: August 2016

AbstractNeferine (Nef), a bisbenzylisoquinoline alkaloid from lotus seed embryo has a wide range of pharmacological activities. Possible molecular mechanism for the cytoprotective action of Nef during hypoxic stress has not been explored till now. Hence, this is an attempt to elucidate the molecular mechanism involved in the Nef mediated cytoprotection on hypoxia‐induced cell injury. Cytoprotective dose of Nef in muscle cells (Human rhabdomyosarcoma cells) exposed to hypoxia was determined by MTT assay. Nef at 500 nM offered better cytoprotection and was used for all the experiments. ROS, intracellular calcium accumulation and mitochondrial membrane (ΔψM) potential were measured using fluorescent probes. Further, we evaluated the effect Nef on hypoxia induced inflammatory and apoptotic responses by FACS and analyzing the expression patterns of NF‐κB, COX‐2, HIF‐1α, caspase‐3, caspase‐9, Bcl2, and Bax. The results of this study revealed that pretreatment of the cells with Nef significantly decreased the ΔψM and ROS in the cells subjected to hypoxia. Further, Nef inhibited NF‐κB there by inhibiting the expression of its downstream regulator COX‐2, while it induced the functional HIF‐1α expression. The results also indicate that Nef significantly inhibited the ROS dependent mitochondrial mediated apoptosis induced during hypoxia. The cytoprotection elicited by Nef in a model of hypoxia induced cell death involves both anti‐inflammatory and anti‐apoptotic response. These results suggest that Nef may be used as prophylactic agent against the hypoxic challenge. © 2016 BioFactors, 42(4):407–417, 2016
Quantification of mesembrine and mesembrenone in mouse plasma using UHPLC‐QToF‐MS: Application to a pharmacokinetic study
Authors: Manda Vamshi K. , Avula Bharathi , Ashfaq Mohammad K. , Abe Naohito , Khan Ikhlas A. , Khan Shabana I. 
Published: August 2016

AbstractSceletium tortuosum, is an indigenous herb of South Africa which is widely used as an herbal supplement in the treatment of anxiety and stress. Mesembrenone and mesembrine are the two main pharmacologically active alkaloids present in the extract. Despite the wide therapeutic applications of Sceletium extract, there are no reports of in vivo pharmacokinetic properties or analytical methods to quantify these two important alkaloids in plasma. Therefore, the current study aimed to develop and validate a simple and sensitive analytical method for simultaneous quantification of mesembrenone and mesembrine in mouse plasma. Ultra‐high‐performance liquid chromatography–mass spectrometry (UHPLC/QToF‐MS) was employed to achieve our objectives. The compounds were extracted using protein precipitation by methanol (100%) with quinine as an internal standard. The lower limit of quantification for both the compounds was 10 ng/mL. The extraction recovery was between 87 and 93% for both compounds with no matrix effects on the analysis. The accuracy was between 89.5 and 106% and precision was <12.6% for all quality control samples. This validated method was successfully applied to evaluate the i.v. plasma pharmacokinetics of mesembrine and mesembrenone in mouse. However, the oral bioavailability of these alkaloids was poor and the plasma levels were below the detection limits.
Exploitation of multiplayer interaction and development of virtual puppetry storytelling using gesture control and stereoscopic devices
Authors: Liang Hui , Chang Jian , Deng Shujie , Chen Can , Tong Ruofeng , Zhang Jian Jun 
Published: August 2016

AbstractWith the rapid development of human–computer interaction technologies, the new media generation demands novel learning experiences with natural interaction and immersive experience. Considering that digital storytelling is a powerful pedagogical tool for young children, in this paper, we design an immersive storytelling environment that allows multiple players to use naturally interactive hand gestures to manipulate virtual puppetry for assisting narration. A set of multimodal interaction techniques is presented for a hybrid user interface that integrates existing 3D visualization and interaction devices including head‐mounted displays and depth motion sensor. In this system, the young players could intuitively use hand gestures to manipulate virtual puppets to perform a story and interact with props in a virtual stereoscopic environment. We have conducted a user experiment with four young children for pedagogical evaluation, as well as system acceptability and interactivity evaluation by postgraduate students. The results show that our framework has great potential to stimulate learning abilities of young children through collaboration tasks. The stereoscopic head‐mounted display outperformed the traditional monoscopic display in a comparison between the two.