bluuebunny/crossref_metadata_2025_split huggingface dataset:
Minutes Synthesis of 1,4,5‐Trisubstituted 5‐Dialkylamino‐1,2,3‐triazoles by 1‐Copper(I)‐Alkyne Controlled Tandem Process
Authors: Wang Bo , Liu Nan , Chen Wenwen , Huang Dayun , Wang Xinyan , Hu Yuefei 
Published: September 2014

AbstractIn existing CuAAC methods, the 1,4,5‐trisubstituted 1,2,3‐triazole unit usually was synthesized by trapping the 5‐metal‐1,2,3‐triazole intermediate (M=Cu, Bi or Al) with an electrophile. But, no 1,4,5‐trisubstituted 5‐dialkylamino‐1,2,3‐triazole has yet been synthesized for unknown reasons. We found that this problem may be caused by the strong oxidizing property of the amine electrophile (R2N+) or by the low reactivity of the MC bond in the intermediate. However, when a polymeric complex 1‐copper(I)‐alkyne was used as a substrate, the highly reactive 5‐copper(I)‐1,2,3‐triazole intermediate formed smoothly in the presence of the amine electrophile (R2N+). Finally, the first general synthesis of 1,4,5‐trisubstituted 5‐dialkylamino‐1,2,3‐triazoles was developed via the tandem reaction of 1‐copper(I)‐alkynes with azides and then with O‐benzoyl hydroxylamines at room temperature which occurred within five minutes.magnified image
Intermolecular [3+2] Annulation of Cyclopropylanilines with Alkynes, Enynes, and Diynes via Visible Light Photocatalysis
Authors: Nguyen Theresa H. , Morris Scott A. , Zheng Nan 
Published: September 2014

AbstractOne‐step syntheses of carbocycles substituted with amines from simple starting materials remain rare. We recently developed an intermolecular [3+2] annulation of cyclopropylanilines with alkenes and alkynes that enables this one‐step synthesis. Herein, we report our findings for a full‐scale study of the annulation. Significant expansion of the substrate scope for both cyclopropylanilines and alkynes has been achieved. A range of structurally diverse carbocycles substituted with amines is prepared.magnified image
Impairment of paravascular clearance pathways in the aging brain
Authors: Kress Benjamin T. , Iliff Jeffrey J. , Xia Maosheng , Wang Minghuan , Wei Helen S. , Zeppenfeld Douglas , Xie Lulu , Kang Hongyi , Xu Qiwu , Liew Jason A. , Plog Benjamin A. , Ding Fengfei , Deane Rashid , Nedergaard Maiken 
Published: September 2014

ObjectiveIn the brain, protein waste removal is partly performed by paravascular pathways that facilitate convective exchange of water and soluble contents between cerebrospinal fluid (CSF) and interstitial fluid (ISF). Several lines of evidence suggest that bulk flow drainage via the glymphatic system is driven by cerebrovascular pulsation, and is dependent on astroglial water channels that line paravascular CSF pathways. The objective of this study was to evaluate whether the efficiency of CSF–ISF exchange and interstitial solute clearance is impaired in the aging brain.MethodsCSF–ISF exchange was evaluated by in vivo and ex vivo fluorescence microscopy and interstitial solute clearance was evaluated by radiotracer clearance assays in young (2–3 months), middle‐aged (10–12 months), and old (18–20 months) wild‐type mice. The relationship between age‐related changes in the expression of the astrocytic water channel aquaporin‐4 (AQP4) and changes in glymphatic pathway function was evaluated by immunofluorescence.ResultsAdvancing age was associated with a dramatic decline in the efficiency of exchange between the subarachnoid CSF and the brain parenchyma. Relative to the young, clearance of intraparenchymally injected amyloid‐β was impaired by 40% in the old mice. A 27% reduction in the vessel wall pulsatility of intracortical arterioles and widespread loss of perivascular AQP4 polarization along the penetrating arteries accompanied the decline in CSF–ISF exchange.InterpretationWe propose that impaired glymphatic clearance contributes to cognitive decline among the elderly and may represent a novel therapeutic target for the treatment of neurodegenerative diseases associated with accumulation of misfolded protein aggregates. Ann Neurol 2014;76:845–861
Anionenbindungskatalyse durch elektronenarme Pyridiniumionen
Authors: Berkessel Albrecht , Das Somnath , Pekel Daniel , Neudörfl Jörg‐M. 
Published: September 2014

AbstractWir stellen ein neues Aktivierungskonzept in der Organokatalyse vor: Halogenidbindung durch Coulomb‐Wechselwirkung. Dieser Katalysemodus wurde mithilfe von 3,5‐Dicarbomethoxypyridiniumionen erreicht, die einen zusätzlichen elektronenziehenden Substituenten am Stickstoffatom tragen, z. B. Pentafluorbenzyl oder Cyanmethyl. Für das N‐Pentafluorbenzylderivat wird die Coulomb‐Wechselwirkung – im Festkörper – durch eine Anion‐π‐Wechselwirkung mit dem Perfluorphenylring ergänzt. Bromid und Chlorid werden in einer 1:1‐Stöchiometrie durch die Kationen gebunden. Die katalytische C‐C‐Verknüpfung zwischen 1‐Chlorisochroman (und verwandten Elektrophilen) mit Silylketenacetalen läuft bei −78 °C und mit geringen Katalysatormengen (2 Mol‐%) ab.
Catalytic Enantioselective Alkylation of Sulfenate Anions to Chiral Heterocyclic Sulfoxides Using Halogenated Pentanidium Salts
Authors: Zong Lili , Ban Xu , Kee Choon Wee , Tan Choon‐Hong 
Published: September 2014

AbstractWe report halogenated pentanidiums as phase‐transfer catalysts for the asymmetric alkylation of sulfenate anions to various sulfoxides with high enantioselectivities (up to 99 % ee) and yields (up to 99 %). This approach gives access to enantioenriched heterocyclic sulfoxides that might not be compatible with strong oxidants or organometallic reagents. Computational studies have revealed that the multiple noncovalent interactions such as halogen bonds and nonclassical hydrogen bonds are involved.
Bio‐based diblock copolymers prepared from poly(lactic acid) and natural rubber
Authors: Chumeka Wannapa , Pasetto Pamela , Pilard Jean‐François , Tanrattanakul Varaporn 
Published: September 2014

ABSTRACTNew bio‐based diblock copolymers were synthesized from poly(lactic acid) (PLA) and natural rubber (NR). NR polymer chains were modified to obtain hydroxyl telechelic natural rubber oligomers (HTNR). Condensation polymerization between PLA and HTNR was performed at 110°C during 24 or 48 h. The molecular weight of PLA and HTNR and the molar ratio PLA : HTNR were varied. The new ester linkage in the diblock copolymers was determined by 1H‐NMR. The molecular weight of the diblock copolymers determined from SEC agreed with that expected from calculation. The thermal behavior and degradation temperature were determined by DSC and TGA, respectively. The diblock copolymers were used as a toughening agent of PLA and as a compatibilizer of the PLA/NR blend. PLA blended with the diblock copolymer showed higher impact strength, which was comparable to the one of a PLA/NR blend. The former blend showed smaller dispersed particles as showed by SEM images, indicating the increase in miscibility in the blend due to the PLA block. The compatibilization was effective in the blends containing ∼10 wt % of rubber. At a higher rubber content (>10 wt %), coalescence of the NR and diblock copolymer was responsible of the larger rubber diameter in the blends, which causes a decrease of the impact strength. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41426.
Continuous supercritical decrosslinking extrusion process for recycling of crosslinked polyethylene waste
Authors: Baek Bum Ki , Shin Ji Wook , Jung Jun Yong , Hong Soon Man , Nam Gi Joon , Han Haksoo , Koo Chong Min 
Published: September 2014

ABSTRACTThis work demonstrates that extrusion process can be used as a continuous reactor for the recycling of crosslinked polyethylene (XLPE) via supercritical methanol decrosslinking reaction. The multistage single screw extruder (L/D = 36, D = 40 mm) with methanol injection pump was customized for the continuous supercritical decrosslinking reaction. Reaction temperature was ranged from 360°C to 390°C. The amount of methanol was varied from 0 to 7 mL/min. The extruder provided the crosslinked polymers with the supercritical conditions of methanol during continuous process. The gel content of XLPE decreased with the increase in the reaction temperature and methanol content. Although XLPE experienced supercritical methanol for less than 2 min retention time in the continuous supercritical extruder, it was completely decrosslinked above 390°C at the methanol feeding rate of 7 mL/min. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015, 132, 41442.
Performance of an Adaptive Controller for the Neuromuscular Blockade Based on Inversion of a Wiener Model
Authors: Silva M. M. , Paz L. , Wigren T. , Mendonça T. 
Published: September 2014

AbstractAn adaptive controller based on a minimally parameterized parsimonious Wiener model for the effect of the muscle relaxant rocuronium in the neuromuscular blockade is presented. The controller structure combines inversion of the recursively identified static nonlinearity of the Wiener model with a positive compartmental control law for the linearized system. The overall strategy exploits the fact that the model has only two parameters, which are estimated by an extended Kalman filter. Due to the fact that the positive control law for total mass conservation of compartmental systems is only proven to be convergent for time‐invariant systems, the identification of the parameter in the linear block of the minimally parameterized parsimonious Wiener model is stopped when the controller is turned on. The controller was implemented in the platform Galeno and tested in simulation and in thirteen real cases of patients under general anesthesia. The good reference tracking results and robustness to noise show the reliability of the proposed strategy.
Tracking Performance Achievement for Continuous‐Time Delayed Linear Systems Subject to Actuator Saturation and output Disturbances
Authors: Mahjoub Adel , Van Assche Vincent , Giri Fouad , Chaoui Fatima Z. 
Published: September 2014

AbstractControlling continuous‐time input‐delayed nonminimum‐phase linear systems is addressed in the presence of actuator saturation and output‐disturbances. Focusing on output‐reference tracking, the control design is dealt with in the pseudo‐polynomials ring. A quite appealing L2 ‐tracking performance is shown to be achievable in the presence of arbitrary inputs i.e. the output reference and the output disturbance. The performance is formulated in terms of a well defined output‐reference mismatch error (ORME), depending on the inputs’ rate and their compatibility with the actuator saturation constraint.
Weighted and Constrained Consensus for Distributed Power Dispatch of Scalable Microgrids
Authors: Wang Le Yi , Wang Caisheng , Yin George , Wang Yang 
Published: September 2014

AbstractMicrogrids with distributed energy generators, controllable appliances, electric vehicle charging infrastructures, and energy storage systems introduce new technical challenges in the management of distribution networks. This paper introduces a new framework for power flow control based on the emerging consensus control for networked systems. Due to unique features of power systems, the consensus control problem becomes weighted and constrained, beyond the typical consensus formulation. Using only neighborhood communication for each bus on the microgrid, the consensus control achieves global weighted load balancing. Algorithms are introduced and their convergence properties are established. It is shown that the algorithms have the fastest convergence rates in terms of consensus error variances, by achieving asymptotically the Cramér‐Rao lower bound, and hence is optimal among all algorithms. Examples and case studies demonstrate convergence, robustness, and scalability of the methodology and feasibility in distribution networks. Practical issues are further discussed.
Guaranteed Cost Synchronization of Complex Network Systems with Delay
Authors: Yi‐ping Luo , Bi‐feng Zhou 
Published: September 2014

AbstractThe guaranteed cost synchronization control problem of some general complex dynamical networks with time delay is investigated. A dynamic feedback controller is designed for the system guaranteed cost synchronization. Meanwhile, due to many nodes in the complex networks and the complex of the direct control, use of the the pinning control to make the system achieve guaranteed cost synchronization is also investigated. Based on the Lyapunov stability theory and the matrix inequality, the sufficient conditions are obtained for the existence of the guaranteed cost controller with time delay in complex network. The dynamic feedback controller is designed to ensure the asymptotic stability conditions of the system and make the performance index of the system meet certain requirements. Finally, the feasibility of the proposed method is demonstrated by numerical examples.
Carbon dots as a luminescence sensor for ultrasensitive detection of phosphate and their bioimaging properties
Authors: Xu Jingyi , Zhou Ying , Cheng Guifang , Dong Meiting , Liu Shuxian , Huang Chaobiao 
Published: September 2014

AbstractHighly blue fluorescence carbon dots were synthesized by one‐step hydrothermal treatment of potatoes. The as‐obtained C‐dots have been applied to bioimaging of HeLa cells, which shows their excellent biocompatibility and low cytotoxicity. The results reveal that C‐dots are promising for real cell imaging applications. In addition, the carbon dots can be utilized as a probe for sensing phosphate. Copyright © 2014 John Wiley & Sons, Ltd.
Host–guest inclusion complex of mesalazine and β‐cyclodextrin and spectrofluorometric determination of mesalazine
Authors: Elbashir Abdalla A. , Altayib Alasha Abdalla Fatima , Aboul‐Enein Hassan Y. 
Published: September 2014

AbstractThe supramolecular interaction of mesalazine (MSZ) and β‐cyclodextrin (β‐CD) has been examined by ultraviolet–visible (UV–vis) light, infra‐red (IR) light and fluorescence spectroscopy. The formation of an inclusion complex has been confirmed based on the changes of the spectral properties. MSZ–β‐CD host–guest complex was formed in (1:1) stoichiometry and the inclusion constant (K = 1.359 × 102 L mol–1) was ascertained by typical double reciprocal plots. Furthermore, the thermodynamic parameters (ΔG°, ΔH° and ΔS°) of (MSZ–β‐CD) were obtained. Based on the remarkable enhancement of the fluorescence intensity of MSZ produced through complex formation, a simple, accurate, rapid and highly sensitive spectrofluorometric method for the determination of MSZ in aqueous solution in the presence of β‐CD was developed. The measurement of relative fluorescence intensity was carried with excitation at 330 nm and emission 493 nm. All variables affecting the reactions were studied and optimized. Beer's law was obeyed in the concentration range 0.1–0.45 µg/mL. Absorbance was found to increase linearly with increasing concentration of MSZ, which is corroborated by the calculated correlation coefficient values of 0.99989. The molar absorptivity, Sandell's sensitivity, detection and quantification limits were calculated. The validity of the described methods was assessed, and the method was successfully applied to the determination of MSZ in its pharmaceutical formulation. In addition, a solid inclusion complex was synthesized by co‐precipitation method. Copyright © 2014 John Wiley & Sons, Ltd.
Aquatic proteins with repetitive motifs provide insights to bioengineering of novel biomaterials
Authors: Yang Yun Jung , Jung Dooyup , Yang Byeongseon , Hwang Byeong Hee , Cha Hyung Joon 
Published: September 2014

AbstractProteins with repetitive motifs play vital structural and adhesive functions in nature. Some repeat proteins in particular have adapted to harsh aquatic surroundings to support the survival and reproduction of organisms. Significant effort has been made to identify aquatic repeat proteins with attractive properties and functions to be used as novel biomaterials. Examples of such proteins include matrix proteins from pearl oysters, minicollagens from sea anemones, cement proteins from sandcastle worms, and byssal proteins from marine mussels. Here, several repetitive motifs from aquatic proteins are reviewed, and their characteristic properties are linked to practical uses in three aspects of aquatic life: defense, shelter, and attachment. Some repetitive motifs interact with minerals and consequently generate strong outer cover of shells, and some motifs relate with sticky nature, which contribute to organisms' habitation by adhering themselves in harsh aquatic environments. Other motifs, such as silk‐ or collagen‐like motifs, are also involved in structural rigidity as shown in mussel's byssus and egg membrane. Thus, understanding aquatic repetitive motifs will provide clues about biomedical and biotechnological applications of engineered biomaterials in wet environments.
Recombinase‐Based Isothermal Amplification of Nucleic Acids with Self‐Avoiding Molecular Recognition Systems (SAMRS)
Authors: Sharma Nidhi , Hoshika Shuichi , Hutter Daniel , Bradley Kevin M. , Benner Steven A. 
Published: September 2014

AbstractRecombinase polymerase amplification (RPA) is an isothermal method to amplify nucleic acid sequences without the temperature cycling that classical PCR uses. Instead of using heat to denature the DNA duplex, RPA uses recombination enzymes to swap single‐stranded primers into the duplex DNA product; these are then extended using a strand‐displacing polymerase to complete the cycle. Because RPA runs at low temperatures, it never forces the system to recreate base‐pairs following Watson–Crick rules, and therefore it produces undesired products that impede the amplification of the desired product, complicating downstream analysis. Herein, we show that most of these undesired side products can be avoided if the primers contain components of a self‐avoiding molecular recognition system (SAMRS). Given the precision that is necessary in the recombination systems for them to function biologically, it is surprising that they accept SAMRS. SAMRS‐RPA is expected to be a powerful tool within the range of amplification techniques available to scientists.
Alpha‐Synuclein Binds to the Inner Membrane of Mitochondria in an α‐Helical Conformation
Authors: Robotta Marta , Gerding Hanne R. , Vogel Antonia , Hauser Karin , Schildknecht Stefan , Karreman Christiaan , Leist Marcel , Subramaniam Vinod , Drescher Malte 
Published: September 2014

AbstractThe human alpha‐Synuclein (αS) protein is of significant interest because of its association with Parkinson's disease and related neurodegenerative disorders. The intrinsically disordered protein (140 amino acids) is characterized by the absence of a well‐defined structure in solution. It displays remarkable conformational flexibility upon macromolecular interactions, and can associate with mitochondrial membranes. Site‐directed spin‐labeling in combination with electron paramagnetic resonance spectroscopy enabled us to study the local binding properties of αS on artificial membranes (mimicking the inner and outer mitochondrial membranes), and to evaluate the importance of cardiolipin in this interaction. With pulsed, twofrequency, double‐electron electron paramagnetic resonance (DEER) approaches, we examined, to the best of our knowledge for the first time, the conformation of αS bound to isolated mitochondria.
Cardiac CT and echocardiographic evaluation of peri‐device flow after percutaneous left atrial appendage closure using the AMPLATZER cardiac plug device
Authors: Jaguszewski Milosz , Manes Costantina , Puippe Gilbert , Salzberg Sacha , Müller Maja , Falk Volkmar , Lüscher Thomas , Luft Andreas , Alkadhi Hatem , Landmesser Ulf 
Published: September 2014

ObjectivesThe aim of the study was to examine frequency, size, and localization of peri‐device leaks after percutaneous left atrial appendage (LAA)‐closure with the AMPLATZER‐Cardiac‐Plug (ACP) by using a multimodal imaging approach, i.e. combined cardiac‐CT and TEE follow‐up.BackgroundCatheter‐based LAA‐occlusion using ACP aims to reduce the risk of stroke in patients with atrial fibrillation. Detection of peri‐device leaks after ACP implantation by TEE is challenging, the few available data are inconsistent and the frequency of LAA leaks after ACP implantation remains therefore unclear.MethodsCardiac‐CT using a multi‐phase protocol and a second‐generation dual‐source‐CT‐system was performed in 24 patients with non‐valvular atrial fibrillation starting 3 months after LAA‐closure by ACP. Color Doppler multiplane TEE was used to evaluate peri‐device flow.ResultsCardiac‐CT follow‐up detected any persistent LAA contrast filling in 62% of patients (n = 15), but leak‐sizes were small (1.5 ± 1.4 mm). Peri‐device leaks were almost exclusively localized at the posterior portion of the LAA‐orifice (>90%). TEE follow‐up revealed peri‐device flow in 36% of patients (jet‐sizes: ≤ 4 mm). ACP‐lobe compression (>10%) and perpendicular ACP‐lobe orientation to the LAA‐neck axis, that was also dependent on LAA anatomy, were substantially more frequent in patients with complete LAA closure.ConclusionThe present study evaluates for the first time peri‐device flow after LAA closure by ACP using a combined cardiac‐CT and TEE follow‐up. Persistent LAA‐perfusion was frequently detected, leak‐sizes were small and were less frequent when lobe compression was >10% and lobe orientation was perpendicular to the LAA‐neck axis, that was also related to the LAA anatomy. The clinical significance of these small leaks after LAA‐closure using ACP needs to be further evaluated in future studies. © 2014 Wiley Periodicals, Inc.
Toward operative in vivo fluorescence imaging of the c‐Met proto‐oncogene for personalization of therapy in ovarian cancer
Authors: Liu Shujuan , Zheng Yong , Volpi Davide , El‐Kasti Muna , Klotz Daniel , Tullis Iain , Henricks Andrea , Campo Leticia , Myers Kevin , Laios Alex , Thomas Peter , Ng Tony , Dhar Sunanda , Becker Christian , Vojnovic Borivoj , Ahmed Ahmed Ashour 
Published: September 2014

BACKGROUNDStandard biomarker testing of a single macroscopic disease site is unlikely to be sufficient because of tumor heterogeneity. A focus on examining global biomarker expression or activity, particularly in microscopic residual chemotherapy‐resistant disease, is needed for the appropriate selection of targeted therapies. This study was aimed at establishing a technique for the assessment of biomarkers of ovarian cancer peritoneal spread.METHODSAn in‐house developed fluorescent imaging device was used to detect the expression of the c‐Met oncogene in ovarian cancer. A modified cyanine 5–tagged peptide, GE137, with a high in vitro affinity for the human c‐Met protein, was tested in a panel of ovarian cancer cell lines. Finally, the feasibility of detecting submillimeter ovarian cancer cell peritoneal metastases in vivo was tested through the intravenous injection of GE137 into mice with tumor xenografts.RESULTSUsing optical imaging it was possible to detect c‐Met expression in submillimeter peritoneal metastases that were freshly excised from a human high‐grade serous ovarian cancer. GE137 selectively bound to the c‐Met tyrosine kinase without activating survival signaling pathways (AKT or extracellular signal‐regulated kinase phosphorylation) downstream of c‐Met. GE137 specifically accumulated in SKOv3 ovarian cancer cells expressing c‐Met via clathrin‐mediated endocytosis and emitted a fluorescent signal that lasted for at least 8 hours in tumor xenografts in vivo with a sustained high signal‐to‐noise ratio.CONCLUSIONSOur results suggest that intraoperative optical imaging could provide a new paradigm for selecting cancer patients for appropriate targeted therapies, particularly after initial chemotherapy. Cancer 2015;121:202–13. © 2014 American Cancer Society.