bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Small‐Molecule FRET Reporter for the Real‐Time Visualization of Cell‐Surface Proteolytic Enzyme Functions
Authors: Mu Jing , Liu Fang , Rajab Muhammad Shafiq , Shi Meng , Li Shuang , Goh Chiching , Lu Lei , Xu Qing‐Hua , Liu Bin , Ng Lai Guan , Xing Bengang 
Published: October 2014

AbstractReal‐time imaging of cell‐surface‐associated proteolytic enzymes is critical to better understand their performances in both physiological and pathological processes. However, most current approaches are limited by their complexity and poor membrane‐anchoring properties. Herein, we have designed and synthesized a unique small‐molecule fluorescent probe, which combines the principles of passive exogenous membrane insertion and Förster resonance energy transfer (FRET) to image cell‐surface‐localized furin‐like convertase activities. The membrane‐associated furin‐like enzymatic cleavage of the peptide probe leads to an increased fluorescence intensity which was mainly localized on the plasma membrane of the furin‐expressed cells. This small‐molecule fluorescent probe may serve as a unique and reliable reporter for real‐time visualization of endogenous cell‐surfaceassociated proteolytic furin‐like enzyme functions in live cells and tissues using one‐photon and two‐photon microscopy.
Asymmetrische Disulfonimid‐katalysierte Synthese von δ‐Amino‐β‐ketoestern durch vinyloge Mukaiyama‐Mannich‐Reaktionen
Authors: Wang Qinggang , van Gemmeren Manuel , List Benjamin 
Published: October 2014

AbstractEine organokatalytische asymmetrische Synthese von δ‐Amino‐β‐ketoestern wurde entwickelt. Ein chirales Disulfonimid (DSI) dient als hocheffizienter Präkatalysator einer vinylogen Mukaiyama‐Mannich‐Reaktion von leicht zugänglichen, Dioxinon‐abgeleiteten Silyloxydienen mit N‐Boc‐geschützten Iminen, die die Produkte in ausgezeichneten Ausbeuten und Enantioselektivitäten liefert. Der präparative Nutzen dieser Reaktion wird durch verschiedenste Umwandlungen illustriert, darunter eine neuartige C‐C‐Bindungsknüpfung, die wertvolle enantiomerenangereicherte Bausteine liefern. Die Methode wird in der formalen Synthese von (−)‐Lasubin angewendet.
An Upconversion Nanoparticle with Orthogonal Emissions Using Dual NIR Excitations for Controlled Two‐Way Photoswitching
Authors: Lai Jinping , Zhang Yixiao , Pasquale Nicholas , Lee Ki‐Bum 
Published: October 2014

AbstractDeveloping multicolor upconversion nanoparticles (UCNPs) with the capability of regulating their emission wavelengths in the UV to visible range in response to external stimuli can offer more dynamic platforms for applications in high‐resolution bioimaging, multicolor barcoding, and driving multiple important photochemical reactions, such as photoswitching. Here, we have rationally designed single‐crystal core–shell‐structured UCNPs which are capable of orthogonal UV and visible emissions in response to two distinct NIR excitations at 808 and 980 nm. The orthogonal excitation–emission properties of such UCNPs, as well as their ability to utilize low‐power excitation, which attenuates any local heating from the lasers, endows the UCNPs with great potential for applications in materials and biological settings. As a proof of concept, the use of this UCNP for the efficient regulation of the two‐way photoswitching of spiropyran by using dual wavelengths of NIR irradiation has been demonstrated.
Ein Nanowechselschalter zur Kontrolle zweier katalytischer Prozesse
Authors: De Soumen , Pramanik Susnata , Schmittel Michael 
Published: October 2014

AbstractDas reversible Umschalten zwischen zwei Zuständen des dreieckigen Nanoschalters [Cu(1)]+ wurde durch wechselweise Zugabe von 2‐Ferrocenyl‐1,10‐phenanthrolin (2) und Kupfer(I)‐Ionen veranlasst. Die zwei Schaltzustände regulieren die Bindung und Freisetzung zweier unterschiedlicher Katalysatoren, Piperidin und [Cu(2)]+, in vollständig interferenzfreier Weise und ermöglichen das abwechselnde Ein/Aus‐Schalten von zwei orthogonalen Katalyseprozessen. Im Schaltzustand I wird Piperidin vom Nanoschalter freigesetzt und katalysiert eine Knoevenagel‐Addition zwischen 4‐Nitrobenzaldehyd und Diethylmalonsäureester (AN‐1 und AUS‐2), während im Schaltzustand II das freigesetzte [Cu(2)]+ eine Klick‐Reaktion zwischen 4‐Nitrophenylacetylen und Benzylazid (AUS‐1 und AN‐2) katalysiert. Nach Zugabe eines Äquivalents von 2 zum (AUS‐1 und AN‐2)‐Zustand werden beide katalytisch aktiven Prozesse stillgelegt (AUS‐1 und AUS‐2).
Oxidative Enantioselective α‐Fluorination of Aliphatic Aldehydes Enabled by N‐Heterocyclic Carbene Catalysis
Authors: Li Fangyi , Wu Zijun , Wang Jian 
Published: October 2014

AbstractDescribed is the first study on oxidative enantioselective α‐fluorination of simple aliphatic aldehydes enabled by N‐heterocyclic carbene catalysis. N‐fluorobis(phenyl)sulfonimide serves as a an oxidant and as an “F” source. The CF bond formation occurs directly at the α position of simple aliphatic aldehydes, thus overcoming nontrivial challenges, such as competitive difluorination and nonfluorination, and proceeds with high to excellent enantioselectivities.
A Doubly Alkynylpyrene‐Threaded [4]Rotaxane That Exhibits Strong Circularly Polarized Luminescence from the Spatially Restricted Excimer
Authors: Inouye Masahiko , Hayashi Koichiro , Yonenaga Yuki , Itou Tatsuya , Fujimoto Kazuhisa , Uchida Taka‐aki , Iwamura Munetaka , Nozaki Koichi 
Published: October 2014

AbstractThe Sonogashira coupling of γ‐CD‐encapsulated alkynylpyrenes with terphenyl‐type stopper molecules gave a doubly alkynylpyrene‐threaded [4]rotaxane. The rotaxane showed only excimer emission, with a high fluorescence quantum yield of Φf=0.37, arising from the spatially restricted excimer within the cavity of the γ‐CD. The excimer emission suffered little from self‐quenching up to a concentration of 1.5×10−5 M and was circularly polarized with a high glum value of −1.5×10−2. The strong circularly polarized luminescence may result from the two stacked pyrenes existing in the rotaxane in an asymmetrically twisted manner.
A Toggle Nanoswitch Alternately Controlling Two Catalytic Reactions
Authors: De Soumen , Pramanik Susnata , Schmittel Michael 
Published: October 2014

AbstractReversible switching between two states of the triangular nanoswitch [Cu(1)]+ was accomplished by alternate addition of 2‐ferrocenyl‐1,10‐phenanthroline (2) and copper(I) ions. The two switching states regulate the binding and release of two distinct catalysts, piperidine and [Cu(2)]+, in a fully interference‐free manner and allow alternating on/off switching of two orthogonal catalytic processes. In switching state I, piperidine is released from the nanoswitch and catalyzes a Knoevenagel addition between 4‐nitrobenzaldehyde and diethyl malonate (ON‐1 and OFF‐2), while in state II the released [Cu(2)]+ catalyzes a click reaction between 4‐nitrophenylacetylene and benzylazide (OFF‐1 and ON‐2). Upon addition of one equivalent of 2 to the (OFF‐1 and ON‐2)‐state, both catalytically active processes are shut down (OFF‐1 and OFF‐2).
Synthesis of Highly Functionalized Polycyclic Quinoxaline Derivatives Using Visible‐Light Photoredox Catalysis
Authors: He Zhi , Bae Minwoo , Wu Jie , Jamison Timothy F. 
Published: October 2014

AbstractA mild and facile method for preparing highly functionalized pyrrolo[1,2‐a]quinoxalines and other nitrogen‐rich heterocycles, each containing a quinoxaline core or an analogue thereof, has been developed. The novel method features a visible‐light‐induced decarboxylative radical coupling of ortho‐substituted arylisocyanides and radicals generated from phenyliodine(III) dicarboxylate reagents and exhibits excellent functional group compatibility. A wide range of quinoxaline heterocycles have been prepared. Finally, a telescoped preparation of these polycyclic compounds by integration of the in‐line isocyanide formation and photochemical cyclization has been established in a three‐step continuous‐flow system.
Copper‐Catalyzed Asymmetric Synthesis of Tertiary α‐Hydroxy Phosphonic Acid Derivatives with In Situ Generated Nitrosocarbonyl Compounds as the Oxygen Source
Authors: Maji Biplab , Yamamoto Hisashi 
Published: October 2014

Abstractα‐Hydroxy phosphonic acids and their derivatives are highly bioactive structural motifs. It is now reported that these compounds can be accessed through the copper‐catalyzed direct α‐oxidation of β‐ketophosphonates using in situ generated nitrosocarbonyl compounds as an electrophilic oxygen source. These reactions proceeded in high yields (up to 95 %) and enantioselectivities (up to >99 % ee) for both cyclic as well as acyclic substrates. This method was also applied for the synthesis of α,β‐dihydroxy phosphonates and β‐amino‐α‐hydroxy phosphonates.
Short and Efficient Syntheses of Protoberberine Alkaloids using Palladium‐Catalyzed Enolate Arylation
Authors: Gatland Alice E. , Pilgrim Ben S. , Procopiou Panayiotis A. , Donohoe Timothy J. 
Published: October 2014

AbstractA concise synthesis of the biologically active alkaloid berberine is reported, and a versatile palladium‐catalyzed enolate arylation is used to form the isoquinoline core. The overall yield of 50 % is a large improvement over the single, previous synthesis. By design, this modular route allows the rapid synthesis of other members of the protoberberine family (e.g., pseudocoptisine and palmatine) by substitution of the readily available aryl bromide and ketone coupling partners. Moreover, by combining enolate arylation with in situ functionalization, substituents can be rapidly and regioselectively introduced at the alkaloid C13 position, as demonstrated by the total synthesis of dehydrocorydaline. The avoidance of electrophilic aromatic substitution reactions to make the isoquinoline allows direct access to analogues possessing more varied electronic properties, such as the fluorine‐containing derivative synthesized here.
Preparation of O‐hydroxypropyl‐N‐butyl chitosan under microwave irradiation
Authors: Liang Xiangyu , Wen Junjie , Wen Caihong , Wang Bo , Chen Jianyu , Zhou Li 
Published: October 2014

ABSTRACTO‐Hydroxypropyl‐N‐butyl chitosan (C4‐HPCS) was prepared by microwave irradiation and phase‐transfer catalysis; this consisted of two steps: (1) the synthesis of O‐hydroxypropyl chitosan (HPCS) with chitosan and propylene oxide and (2) the synthesis of C4‐HPCS with HPCS and 1‐butyl bromide. The results of the experiment are as follows: Fourier transform infrared spectroscopy and 1H‐NMR displayed the characteristic peaks of C4‐HPCS, thermogravimetric analysis showed that C4‐HPCS was stable until 240°C, the critical micelle concentration was 0.025 wt %, the surface tension was equal to 65.70 ± 0.09 mN/m, the hydrophile–lipophile balance number value was 13.55, and the emulsifying power, foaming expansion, and foaming volume stability were 73.10, 45, and 94 wt %, respectively. This indicated that C4‐HPCS had superior surface performance and more excellent hydrophilicity. In addition, the microwave irradiation and phase‐transfer catalysis used in the experiment were considered to be more environmentally friendly and time‐saving methods. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41527.
Rapeseed oil‐based polyurethane foams modified with glycerol and cellulose micro/nanocrystals
Authors: Mosiewicki Mirna A. , Rojek Piotr , Michałowski Sławomir , Aranguren Mirta I. , Prociak Aleksander 
Published: October 2014

ABSTRACTA rapeseed oil‐based polyol (ROPO) was synthesized using chemical modification of the rapeseed oil (RO) by epoxidation reaction followed by oxirane ring‐opening with diethylene glycol. The ROPO was used in the formulation of low‐density green polyurethane (PU) foams. The use of glycerol as hydroxyl component, water as a reactive blowing agent and micro/nanocellulose (MNC) as a reinforcement increases the content of natural components in the formulations with important effects on the final foam properties. The ROPO and their intermediate products are characterized by analytical techniques and FTIR spectroscopy, while the final PU foams are characterized by morphological and mechanical analysis. The results show that the addition of glycerol increases the modulus and yield stress. The incorporation of MNC in small amounts is enough to increase the modulus at low temperatures. Both modifiers cause an increase in water absorption and the fragility of the cell walls, reflected in the micrographs of the foams. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41602.
Not just carbon: assessment and prospects for the application of anthracology in Oceania
Authors: Dotte‐Sarout Emilie , Carah Xavier , Byrne Chae 
Published: October 2014

AbstractWhile archaeobotany is increasingly part of archaeological projects in Oceania, the specific sub‐discipline focusing on wood charcoal macro‐remains (anthracology) continues to be a much underdeveloped field of research in Australia and the Pacific. To initiate a regional framework for anthracology, we present here a review of studies based on wood charcoal analyses that have been implemented in Oceania, and we then present anthracological principles and methods developed in other parts of the world. We use three recent case studies, from New Caledonia, and tropical and semi‐arid Australia, to illustrate the application of anthracological methods in the region. Finally, we consider the potential for the discipline to be successfully developed in Oceania, discussing identified challenges and prospects for anthracology to address key archaeological questions in the region. We argue the discipline has the potential to throw light on both palaeoenvironmental conditions and palaeoethnobotanical practices at a site, and can also offer insights in relation to mobility patterns and resource management in the past.
A Learning Model for Racket Motion Decision in Ping‐Pong Robotic System
Authors: Su Hu , Xu De , Chen Guodong , Fang Zaojun , Tan Min 
Published: October 2014

AbstractIn this paper, a model of computing the desired velocity of returning balls is developed so that the robot could return the incoming ball to a desired point on the table with specified landing velocity. At first, three polynomials of the flying time are applied to fit the ball's trajectory while neglecting the effort of Magnus force; one result of returning velocity is obtained after the coefficients of the polynomials are estimated using the LM (Levenberg‐Marquardt) algorithm. Then a new configuration based on area segmentation is proposed which is used in storing and replacing experimental data; another result of the velocity is received by fitting the stored data. The weighted average of the two above mentioned results is regarded as the original value of the fuzzy correcting algorithm. With the analysis of the influence of the desired velocity on the errors between the actual landing point and the desired point, the fuzzy rule is designed. The eventual returning velocity of the ball is obtained using the fuzzy correcting algorithm based on the errors of the landing point predicted by the flying model. Finally, experiments are conducted to verify the performance of the proposed method.
On The Timing of Antiwindup Compensation
Authors: Binotti Vinicius , Bender Fernando A. 
Published: October 2014

AbstractIn this paper we address the problem of determining the effect of the timing of the antiwindup compensation on the stability of a class of nonlinear systems. Besides proposing a new and less conservative synthesis framework, we move forward and compare the impact of antiwindup compensation when it occurs immediately or it is delayed. The class of systems considered are input saturating linear systems with known and constant time delay in both the input and the states. The synthesis of these antiwindup compensators is carried out on a linear matrix inequality (LMI)‐based framework whose development is based on the use of a Lyapunov–Krasovskii functional, a generalized sector condition, and a negligibly constrained usage of the Finsler Lemma. We compare results by computing the upper bound of the
‐norm on the admissible disturbances for which the system trajectories are assured to be bounded.
Output Swarm Stability and Stabilization for High‐Order Linear Swarm Systems
Authors: Xi Jianxiang , Liu Hao , Yu Zhiyong , Yang Bailong , Liu Guangbin 
Published: October 2014

AbstractOutput swarm stability and stabilization problems for high‐order linear swarm systems with directed interaction topologies are investigated. First, sufficient conditions for output swarm stability are presented, and an approach is proposed to determine the absolute output motion, where the influences of initial states of agents and swarm stabilizing protocols are given. Moreover, it is shown that swarm systems with the same initial states but different balanced interaction topologies have the same absolute output motion. Then, sufficient conditions for output swarm stabilization, which are independent of the number of agents, are presented. Finally, numerical simulations are shown to illustrate the correctness of theoretical results.
Stabilization of Singular Markovian Jump Systems by Generally Observer‐based Controllers
Authors: Wang Guoliang , Bo Haiying 
Published: October 2014

AbstractThis paper considers the problem of designing a generally observer‐based controller for a kind of singular Markovian jump systems, where the operation modes of controller and observer are not necessary. Different from the existing methods, several general conditions in terms of mode‐dependent or mode‐independent are obtained by using mode‐dependent Lyapunov functions and developed within LMI framework. In order to solve such problems ultimately, two different techniques dealing with the cross terms are proposed, where new variables satisfying new inequalities are introduced. Numerical examples are presented to show the effectiveness and superiority of the proposed results.
Multifunctional amaranth cystatin inhibits endogenous and digestive insect cysteine endopeptidases: A potential tool to prevent proteolysis and for the control of insect pests
Authors: Valdés‐Rodríguez Silvia , Galván‐Ramírez Juan Pablo , Guerrero‐Rangel Armando , Cedro‐Tanda Alberto 
Published: October 2014

AbstractIn a previous study, the amaranth cystatin was characterized. This cystatin is believed to provide protection from abiotic stress because its transcription is induced in response to heat, drought, and salinity. It has also been shown that recombinant amaranth cystatin inhibits bromelain, ficin, and cysteine endopeptidases from fungal sources and also inhibits the growth of phytopathogenic fungi. In the present study, evidence is presented regarding the potential function of amaranth cystatin as a regulator of endogenous proteinases and insect digestive proteinases. During amaranth germination and seedling growth, different proteolytic profiles were observed at different pH levels in gelatin‐containing SDS‐PAGE. Most of the proteolytic enzymes detected at pH 4.5 were mainly inhibited by trans­epoxysuccinyl‐leucyl amido(4‐guanidino)butane (E‐64) and the purified recombinant amaranth cystatin. Furthermore, the recombinant amaranth cystatin was active against insect proteinases. In particular, the E‐64‐sensitive proteolytic digestive enzymes from Callosobruchus maculatus, Zabrotes subfasciatus, and Acanthoscelides obtectus were inhibited by the amaranth cystatin. Taken together, these results suggest multiple roles for cystatin in amaranth, specifically during germination and seedling growth and in the protection of A. hypochondriacus against insect predation. Amaranth cystatin represents a promising tool for diverse applications in the control of insect pest and for preventing undesirable proteolytic activity.
DNA Dangling‐End‐Induced Colloidal Stabilization of Gold Nanoparticles for Colorimetric Single‐Nucleotide Polymorphism Genotyping
Authors: Akiyama Yoshitsugu , Shikagawa Hiroto , Kanayama Naoki , Takarada Tohru , Maeda Mizuo 
Published: October 2014

AbstractA single‐nucleotide polymorphism (SNP) detection method was developed by combining single‐base primer extension and salt‐induced aggregation of gold nanoparticles densely functionalized with double‐stranded DNA (dsDNA‐AuNP). The dsDNA‐AuNPs undergo rapid aggregation in a medium of high ionic strength, whereas particles having a single‐base protrusion at the outermost surface disperse stably, allowing detection of a single‐base difference in length by color changes. When SNP typing primers are used as analytes to hybridize to the single‐stranded DNA on the AuNP surface, the resulting dsDNA‐AuNP works as a visual indicator of single‐base extension. A set of four extension reaction mixtures is prepared using each of ddNTPs and subsequently subjected to the aggregation assay. Three mixtures involving ddNTP that is not complementary to the SNP site in the target produce the aggregates that exhibit a purple color. In contrast, one mixture with the complementary ddNTP generates the single‐base protrusion and appears red. This method could potentially be used in clinical diagnostics for personalized medicine.
ChemInform Abstract: Insights into Diffusion Mechanisms in P2 Layered Oxide Materials by First‐Principles Calculations.
Authors: Mo Yifei , Ong Shyue Ping , Ceder Gerbrand 
Published: October 2014

AbstractThe diffusion mechanisms in P2 (prismatic) NaxCoO2 are studied using ab initio molecular dynamics simulations and nudged elastic band calculations.
ChemInform Abstract: Comparison of Magnetocaloric Properties of the Mn2‐xFexP0.5As0.5 (x = 1.0 and 0.7) Compounds.
Authors: Zubov E. , et al. et al. 
Published: October 2014

AbstractMn1.3Fe0.7P0.5As0.5 (I) and MnFeP0.5As0.5 (II) are prepared by melting stoichiometric amounts of Mn2P and Fe2As (evacuated quartz ampoule, 1473 K, 2 d) followed by Bridgman directional crystallization (1000 K, 1 d).
ChemInform Abstract: Synthesis, Crystal Structure, and Electrical and Magnetic Properties of BaMo6Te6: A Novel Reduced Molybdenum Telluride Containing Infinite Chains of trans‐Face Shared Mo6 Octahedra.
Authors: Gall Philippe , Guizouarn Thierry , Potel Michel , Gougeon Patrick 
Published: October 2014

AbstractThe new title compound is prepared by solid state reaction of a stoichiometric mixture of BaTe, MoTe2, and Mo (Mo crucible, 1400 °C, 49 h).
ChemInform Abstract: Stereocontrolled Synthesis of Adjacent Acyclic Quaternary‐Tertiary Motifs: Application to a Concise Total Synthesis of (‐)‐Filiformin.
Authors: Blair Daniel J. , Fletcher Catherine J. , Wheelhouse Katherine M. P. , Aggarwal Varinder K. 
Published: October 2014

AbstractLithiation/borylation method delivers acyclic quaternary‐tertiary motifs (VI) with full control of absolute stereochemistry leading to all four possible isomers.
ChemInform Abstract: Organocatalytic Stereoselective Synthesis of 3‐Alkyl‐3‐hydroxy‐2‐oxindoles Catalyzed by Novel Water‐Compatible Axially Unfixed Biaryl‐Based Bifunctional Organocatalysts.
Authors: Zhao Hongwu , Meng Wei , Yang Zhao , Tian Ting , Sheng Zhihui , Li Hailong , Song Xiuqing , Zhang Yutong , Yang Sen , Li Bo 
Published: October 2014

AbstractSix novel axially unfixed biaryl‐based bifunctional organocatalysts are designed, synthesized and applied in aldol reactions of isatins with a variety of enolizable ketones in water.
ChemInform Abstract: The Divergent Synthesis of Nitrogen Heterocycles by Rhodium(II)‐Catalyzed Cycloadditions of 1‐Sulfonyl 1,2,3‐Triazoles with 1,3‐Dienes.
Authors: Shang Hai , Wang Yuanhao , Tian Yu , Feng Juan , Tang Yefeng 
Published: October 2014

AbstractThe novel title synthesis enables the efficient access of two types of aza‐ heterocycles, 2,3‐dihydropyrroles and 2,5‐dihydroazepines, through formal aza‐[3 + 2] and [4 + 3] cycloadditions from readily available starting materials.
ChemInform Abstract: Synthesis of Substituted Adamantylzinc Reagents Using a Mg‐Insertion in the Presence of ZnCl2 and Further Functionalizations.
Authors: Saemann Christoph , Dhayalan Vasudevan , Schreiner Peter R. , Knochel Paul 
Published: October 2014

AbstractA novel procedure for the synthesis of adamantylzinc reagents via LiCl‐mediated Mg‐insertion in the presence of ZnCl2 and reactions of these reagents under various typical coupling reaction conditions (e.