bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study of Solid Particle Erosion Wear Behavior of Bamboo Fiber Reinforced Polymer Composite with Cenosphere Filler
Authors: Jena Hemalata , Pradhan Arun Kumar , Pandit Mihir Kumar 
Published: June 2016

AbstractIn this study, solid particle erosion (SPE) wear behavior of bamboo fiber‐reinforced epoxy composite with cenosphere filler was investigated. Cenosphere is an industrial waste of thermal power plants which is produced during burning of pulverized coals. The present composites consisting of varying weight percentage of fibers and cenosphere fillers were prepared by hand lay‐up technique. The erosion wear rates of these composites have been studied with varying impact velocities and impingement angles. The study reveals that addition of cenosphere filler to the bamboo–epoxy composite reduces its erosion wear rate. Morphologies of the eroded surface of composite samples were inspected by a scanning electron microscope to discuss the behavior of erosion wear. Both bamboo–epoxy composite with and without cenosphere filler show semiductile erosion wear behavior with maximum erosion rate at an impingement angle of 60°.
Long‐term potentiation–like cortical plasticity is disrupted in Alzheimer's disease patients independently from age of onset
Authors: Di Lorenzo Francesco , Ponzo Viviana , Bonnì Sonia , Motta Caterina , Negrão Serra Priscilla C. , Bozzali Marco , Caltagirone Carlo , Martorana Alessandro , Koch Giacomo 
Published: June 2016

ObjectiveAlzheimer's disease (AD) is considered an age‐related disorder. However, it is unclear whether AD induces the same pathological and neurophysiological modifications in synaptic functions independently from age of disease onset. We used transcranial magnetic stimulation tools to investigate the mechanisms of cortical plasticity and sensory‐motor integration in AD patients with a wide range of disease onset.MethodsWe evaluated newly diagnosed sporadic AD (n = 54) in comparison with healthy age‐matched controls (HS; n = 24). Cortical plasticity mechanisms of long‐term potentiation (LTP) or of long‐term depression (LTD) were assessed using respectively intermittent (iTBS) or continuous theta burst stimulation (cTBS) protocols. Sensory‐motor integration was evaluated by means of short afferent inhibition (SAI) protocol.ResultsAD patients show after iTBS an impairment of LTP‐like cortical plasticity forming a paradoxical LTD in comparison to HS. LTD‐like cortical plasticity is similar between AD and HS. LTP‐like cortical plasticity is not associated with age, but AD patients presenting with more altered LTP‐like cortical plasticity have more‐severe cognitive decline at 18 months. SAI is impaired in AD and shows a strong association with the individual age of subjects rather than with disease age of onset.InterpretationCortical LTP disruption is a central mechanism of AD that is independent from age of onset. AD can be described primarily as a disorder of LTP‐like cortical plasticity not influenced by physiological aging and associated with a more‐severe cognitive decline. Ann Neurol 2016;80:202–210
From a Sequential to a Concurrent Reaction in Aqueous Medium: Ruthenium‐Catalyzed Allylic Alcohol Isomerization and Asymmetric Bioreduction
Authors: Ríos‐Lombardía Nicolás , Vidal Cristian , Liardo Elisa , Morís Francisco , García‐Álvarez Joaquín , González‐Sabín Javier 
Published: June 2016

AbstractThe ruthenium‐catalyzed redox isomerization of allylic alcohols was successfully coupled with the enantioselective enzymatic ketone reduction (mediated by KREDs) in a concurrent process in aqueous medium. The overall transformation, formally the asymmetric reduction of allylic alcohols, took place with excellent conversions and enantioselectivities, under mild reaction conditions, employing commercially and readily available catalytic systems, and without external coenzymes or cofactors. Optimization resulted in a multistep approach and a genuine cascade reaction where the metal catalyst and biocatalyst coexist from the beginning.
Identifikation von Weißweinen durch ionische Poly(para‐phenylen‐ ethinylene) und ihre Komplexe
Authors: Han Jinsong , Bender Markus , Seehafer Kai , Bunz Uwe H. F. 
Published: June 2016

AbstractEin einfaches Sensorfeld aus einem anionischen und einem kationischen Poly(para‐phenylenethinylen) (PPE) sowie deren elektrostatischem Komplex unterscheidet verschiedene Weißweine. Die PPEs und der Komplex wurden bei pH 13 verwendet. Der Komplex wurde auch bei pH 3 eingesetzt. Diese aus vier Sensorelementen bestehende “chemische Zunge”, unterscheidet 13 verschiedene Weißweine. Grundlage der sensorischen Erkennung ist die Fluoreszenzlöschung der konjugierten Polymere. Die Fluoreszenzlöschung wird nicht durch die Hauptkomponenten des Weines induziert, denn Säuren, Zucker, Alkohole usw. zeigen keine Fluoreszenzlöschung. Die vorrangigen Löscher sind vielmehr die im Wein befindlichen farbigen Tannine und andere Polyphenole. Die Löschung der PPE‐Fluoreszenz durch die Tannine wird allerdings von den Hauptkomponenten des Weines moduliert.
Spontaneous Formation of an Air‐Stable Radical upon the Direct Fusion of Diphenylmethane to a Triarylporphyrin
Authors: Kato Kenichi , Cha Wonhee , Oh Juwon , Furukawa Ko , Yorimitsu Hideki , Kim Dongho , Osuka Atsuhiro 
Published: June 2016

AbstractThe direct fusion of a diphenylmethane segment to a NiII 5,10,15‐triarylporphyrin with three linkages furnished an air‐ and moisture‐stable neutral radical through unexpected and spontaneous oxidation. This radical was demetalated by treatment with H2SO4 and CF3CO2H to provide the corresponding free‐base radical. These porphyrin radicals are very stable owing to spin delocalization and have been fully characterized through UV/Vis/NIR absorption spectroscopy, X‐ray crystallographic analysis, magnetic susceptibility measurements, electrochemical studies, laser‐based ultrafast spectroscopic studies, and theoretical calculations. They were chemically oxidized and reduced to the corresponding cation and anion but did not react with hydrogen‐atom donors.
Nickel‐Catalyzed Decarbonylative Borylation of Amides: Evidence for Acyl C−N Bond Activation
Authors: Hu Jiefeng , Zhao Yue , Liu Jingjing , Zhang Yemin , Shi Zhuangzhi 
Published: June 2016

AbstractA nickel/N‐heterocyclic carbene catalytic system has been established for decarbonylative borylation of amides with B2nep2 by C−N bond activation. This transformation shows good functional‐group compatibility and can serve as a powerful synthetic tool for late‐stage borylation of amide groups in complex compounds. More importantly, as a key intermediate, the structure of an acyl nickel complex was first confirmed by X‐ray analysis. Furthermore, the decarbonylative process was also observed. These findings confirm the key mechanistic features of the acyl C−N bond activation process.
Identification of White Wines by using Two Oppositely Charged Poly(p‐phenyleneethynylene)s Individually and in Complex
Authors: Han Jinsong , Bender Markus , Seehafer Kai , Bunz Uwe H. F. 
Published: June 2016

AbstractWe present a simple array composed of an anionic and a cationic poly(para‐phenyleneethynylene) (PPE), together with an electrostatic complex between the two of them. The individual PPEs and the PPE complex were employed in the sensing of white wines at pH 13; the complex was also successfully employed as a sensor element at pH 3. The sensing mechanism is fluorescence quenching. Thirteen different wines were differentiated by this chemical tongue, which consists of four elements. The fluorescence quenching is not induced by the major components of the wines. Compounds such as acids, sugars, and alcohols alone do not quench the fluorescence, but rather the colored tannins and other polyphenols contained in wine are the main quenchers. However, the major constituents of wine significantly modulate the quenching of the PPEs by the tannins.
Preparation and characterization of an amphiphilic macrophotoinitiator based on 2‐hydroxyl‐2‐methyl‐1‐phenylpropanone
Authors: Xie Yangzhi , Huang He 
Published: June 2016

ABSTRACTOn the basis of 2‐hydroxyl‐2‐methyl‐1‐phenylpropanone (HMPP) and poly(ethylene glycol) (PEG), we prepared amphiphilic macrophotoinitiators (HMPP–PEG–HMPP) by first reacting HMPP with isophorone diisocyanate and subsequently reacting it with PEGs with different chain lengths. Fourier transform infrared spectroscopy, high‐performance liquid chromatography, and 1H‐NMR were used to confirm the structure of the amphiphilic macrophotoinitiators. Ultraviolet (UV) absorption spectra showed that the amphiphilic macrophotoinitiators had maximum absorption wavelengths that were similar to those of the low‐molecular‐weight photoinitiator HMPP. The photolysis rate of the amphiphilic macrophotoinitiators was slightly lower than that of HMPP, but the migration rate of the amphiphilic macrophotoinitiators from a UV‐cured matrix was much lower compared to that of HMPP. Because of their amphiphilic nature, these macrophotoinitiators may play roles as both photoinitiators and emulsifiers, and they have been applied to the solution polymerization of water‐soluble monomer acrylamide in water and the emulsion polymerization of methyl methacrylate. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43910.
Noble‐Metal Nanocrystals with Controlled Facets for Electrocatalysis
Authors: Hong Jong Wook , Kim Yena , Kwon Yongmin , Han Sang Woo 
Published: June 2016

AbstractNoble‐metal nanocrystals (NCs) show excellent catalytic performance for many important electrocatalysis reactions. The crystallographic properties of the facets by which the NCs are bound, closely associated with the shape of the NCs, have a profound influence on the electrocatalytic function of the NCs. To develop an efficient strategy for the synthesis of NCs with controlled facets as well as compositions, understanding of the growth mechanism of the NCs and their interaction with the chemical species involved in NC synthesis is quite important. Furthermore, understanding the facet‐dependent catalytic properties of noble‐metal NCs and the corresponding mechanisms for various electrocatalysis reactions will allow for the rational design of robust electrocatalysts. In this review, we summarize recently developed synthesis strategies for the preparation of mono‐ and bimetallic noble‐metal NCs by classifying them by the type of facets through which they are enclosed and discuss the electrocatalytic applications of noble‐metal NCs with controlled facets, especially for reactions associated with fuel‐cell applications, such as the oxygen reduction reaction and fuel (methanol, ethanol, and formic acid) oxidation reactions.
Unraveling the aggregation propensity of human insulin C‐peptide
Authors: Tsiolaki Paraskevi L. , Louros Nikolaos N. , Zompra Aikaterini A. , Hamodrakas Stavros J. , Iconomidou Vassiliki A. 
Published: June 2016

ABSTRACTOver the last 20 years, proinsulin C‐peptide emerged as an important player in various biological events. Much time and effort has been spent in exploring all functional features of C‐peptide and recording its implications in Diabetes mellitus. Only a few studies, though, have addressed C‐peptide oligomerization and link this procedure with Diabetes. The aim of our work was to examine the aggregation propensity of C‐peptide, utilizing Transmission Electron Microscopy, Congo Red staining, ATR‐FTIR, and X‐ray fiber diffraction at a 10 mg ml−1concentration. Our experimental work clearly shows that C‐peptide self‐assembles into amyloid‐like fibrils and therefore, the aggregation propensity of C‐peptide is a characteristic novel feature that should be related to physiological and also pathological conditions. © 2016 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 108: 1–8, 2017.
Cardiovascular Outcomes Following Rotational Atherectomy: A UK Multicentre Experience
Authors: Eftychiou Christos , Barmby David S. , Wilson Simon J. , Ubaid Salahaddin , Markwick Andrew J. , Makri Loukia , Blaxill Jonathan M. , Spratt James C. , Gunning Mark , Greenwood John P. 
Published: June 2016

ObjectivesTo identify factors associated with outcomes following rotational atherectomy (RA).BackgroundRA is an effective way to mechanically modify heavily calcified lesions before stenting; however its outcomes are not well defined.Methods and ResultsRetrospective evaluation of all patients who underwent RA in three large UK centers (Leeds General Infirmary (LGI), Royal Infirmary of Edinburgh (RIE) and University Hospital of North Staffordshire (UHNS)) from March 2005 to January 2013. Five hundred and eighteen patients had RA with median follow‐up period of 22 months. About 68.3% were male, 28.7% had DM and 34.6% were treated because of ACS. Stents were deployed in 97.3% of the patients while 30.7% of the procedures were performed transradially. Maximum burr was ≤1.75 mm in 85.5% and the mean SYNTAX score was 19.5 ± 11.6. Peri‐procedural complications occurred in 6.4% and vascular access complications in 1.9%. Outcomes in the follow‐up period were: MACE 17.8%, cardiac death 7.1%, MI 11.7%, TVR 7.5%, all‐cause death 13.7%, definite stent thrombosis (ST) 1.4% and stroke 2.9%. Patients with intermediate and high SYNTAX scores were more likely to suffer MACE, cardiac death, MI, all‐cause death and ST. Patients with a SYNTAX score >32 were also more likely to have a peri‐procedural complication. Multiple logistic regression analysis showed that the presence of PVD (P = 0.026, OR = 2.0), DM (P = 0.008, OR = 2.1), ACS presentation (P = 0.011, OR = 2.1) and SYNTAX score ≥23 (P = 0.02, OR = 1.9) had a significant association with MACE.ConclusionsRA is safe and effective, with high rate of procedural success and relatively low incidence of MACE. PVD, DM, ACS presentation and SYNTAX score were significant predictors for MACE. © 2016 Wiley Periodicals, Inc.
Procedural outcomes with use of the flash ostial system in aorto‐coronary ostial lesions
Authors: Nguyen‐Trong Phuong‐Khanh J. , Martinez Parachini Jose Roberto , Resendes Erica , Karatasakis Aris , Danek Barbara A. , Alame Aya , Makke Lorenza B. , Ayers Colby R. , Roesle Michele , Rangan Bavana , Banerjee Subhash , Brilakis Emmanouil S. 
Published: June 2016

BackgroundThe Flash Ostial system (Ostial Corporation, Sunnyvale, CA) was designed to optimize implantation of aorto‐ostial coronary stents by flaring the proximal stent struts against the aortic wall.MethodsWe retrospectively reviewed the medical record, angiograms, and intravascular ultrasound images of 22 aorto‐ostial percutaneous coronary interventions performed at our institution between March and September 2015. The Flash Ostial system was used in 13 cases (59%).ResultsMean age was 67 ± 8 years and all patients were men. The target vessel was the right coronary artery (59%), left main (27%), or a saphenous vein graft (14%); 59% of the lesions had moderate/severe calcification. The mean number of predilation balloons was 1.8 ± 1.6, mean Flash ostial balloon diameter was 3.3 ± 0.5 mm and mean inflation pressure was 13.1 ± 4.0 atmospheres. Intravascular ultrasonography (available for 19 patients) revealed mean ostial minimum lumen cross‐sectional area (MLA) of 9.2 ± 3.0 mm2 and reference MLA of 8.5 ± 2.7 mm2. The percent difference between ostial and reference MLA was higher in cases in which the Flash Ostial system was used versus those where it was not (9.6 ± 5.5% vs. 4.0 ± 2.8%, P = 0.03). All stent struts were well apposed. Technical success was 100%. One patient developed a left groin pseudoaneurysm treated with thrombin injection and one patient had a periprocedural myocardial infarction. Median contrast, fluoroscopy time, and procedure time were 235 mL, 33 min, and 118 min, respectively.ConclusionsThe Flash Ostial system can be successfully used in aorto‐ostial stenting, resulting in large ostial vessel MLA. © 2016 Wiley Periodicals, Inc.
Crystal‐Field and Covalency Effects in Uranates: An X‐ray Spectroscopic Study
Authors: Butorin Sergei M. , Kvashnina Kristina O. , Smith Anna L. , Popa Karin , Martin Philippe M. 
Published: June 2016

AbstractThe electronic structure of UV‐ and UVI‐containing uranates NaUO3 and Pb3UO6 was studied by using an advanced technique, namely X‐ray absorption spectroscopy (XAS) in high‐energy‐resolution fluorescence‐detection (HERFD) mode. Due to a significant reduction in core–hole lifetime broadening, the crystal‐field splittings of the 5f shell were probed directly in HERFD‐XAS spectra collected at the U 3d edge, which is not possible by using conventional XAS. In addition, the charge‐transfer satellites that result from U 5f–O 2p hybridization were clearly resolved. The crystal‐field parameters, 5f occupancy, and degree of covalency of the chemical bonding in these uranates were estimated by using the Anderson impurity model by calculating the U 3d HERFD‐XAS, conventional XAS, core‐to‐core (U 4f–3d transitions) resonant inelastic X‐ray scattering (RIXS), and U 4f X‐ray photoelectron spectra. The crystal field was found to be strong in these systems and the 5f occupancy was determined to be 1.32 and 0.84 electrons in the ground state for NaUO3 and Pb3UO6, respectively, which indicates a significant covalent character for these compounds.
Host–Guest Assembly of a Molecular Reporter with Chiral Cyanohydrins for Assignment of Absolute Stereochemistry
Authors: Gholami Hadi , Anyika Mercy , Zhang Jun , Vasileiou Chrysoula , Borhan Babak 
Published: June 2016

AbstractThe absolute stereochemistry of cyanohydrins, derived from ketones and aldehydes, is obtained routinely, in a microscale and derivatization‐free manner, upon their complexation with Zn‐MAPOL, a zincated porphyrin host with a binding pocket comprised of a biphenol core. The host–guest complex leads to observable exciton‐coupled circular dichroism (ECCD), the sign of which is easily correlated to the absolute stereochemistry of the bound cyanohydrin. A working model, based on the ECCD signal of cyanohydrins with known configuration, is proposed.
An Easy Access to Organic Salt‐Based Stimuli‐Responsive and Multifunctional Supramolecular Hydrogels
Authors: Majumder Joydeb , Dastidar Parthasarathi 
Published: June 2016

AbstractBy exploiting orthogonal hydrogen bonding involving supramolecular synthons and hydrophobic/hydrophilic interactions, a new series of simple organic salt based hydrogelators derived from pyrene butyric acid and its β‐alanine amide derivative, and various primary amines has been achieved. The hydrogels were characterised by microscopy, table‐top rheology and dynamic rheology. FTIR, variable‐temperature 1H NMR and emission spectroscopy established the role of various supramolecular interactions such as hydrogen bonding and π–π stacking in hydrogelation. Single‐crystal X‐ray diffraction (SXRD) studies supported the conclusion that orthogonal hydrogen bonding involving amide–amide and primary ammonium monocarboxylate (PAM) synthons indeed played a crucial role in hydrogelation. The hydrogels were found to be stimuli‐responsive and were capable of sensing ammonia and adsorbing water‐soluble dye (methylene blue). All the hydrogelators were biocompatible (MTT assay in RAW 264.7 cells), indicating their suitability for use in drug delivery.
η6‐Arene‐Zirconium‐PNP‐Pincer Complexes: Mechanism of Their Hydrogenolytic Formation and Their Reactivity as Zirconium(II) Synthons
Authors: Plundrich Gudrun T. , Wadepohl Hubert , Clot Eric , Gade Lutz H. 
Published: June 2016

AbstractThe cyclometalated monobenzyl complexes [(CbzdiphosR‐CH)ZrBnX] 1 iPrCl and 1 PhI reacted with dihydrogen (10 bar) to yield the η6‐toluene complexes [(CbzdiphosR)Zr(η6‐tol)X] 2 iPrCl and 2 PhI (cbzdiphos=1,8‐bis(phosphino)‐3,6‐di‐tert‐butyl‐9H‐carbazole). The arene complexes were also found to be directly accessible from the triiodide [(CbzdiphosPh)ZrI3] through an in situ reaction with a dibenzylmagnesium reagent and subsequent hydrogenolysis, as exemplified for the η6‐mesitylene complex [(CbzdiphosPh)Zr(η6‐mes)I] (3 PhI). The tolyl‐ring in 2 iPrCl adopts a puckered arrangement (fold angle 23.3°) indicating significant arene‐1,4‐diido character. Deuterium labeling experiments were consistent with an intramolecular reaction sequence after the initial hydrogenolysis of a Zr−C bond by a σ‐bond metathesis. A DFT study of the reaction sequence indicates that hydrogenolysis by σ‐bond metathesis first occurs at the cyclometalated ancillary ligand giving a hydrido‐benzyl intermediate, which subsequently reductively eliminates toluene that then coordinates to the Zr atom as the reduced arene ligand. Complex 2 PhI was reacted with 2,6‐diisopropylphenyl isocyanide giving the deep blue, diamagnetic ZrII‐diisocyanide complex [(CbzdiphosPh)Zr(CNDipp)2I] (4 PhI). DFT modeling of 4 PhI demonstrated that the HOMO of the complex is primarily located as a “lone pair on zirconium”, with some degree of back‐bonding into the C≡N π* bond, and the complex is thus most appropriately described as a zirconium(II) species. Reaction of 2 PhI with trimethylsilylazide (N3TMS) and 2 iPrCl with 1‐azidoadamantane (N3Ad) resulted in the formation of the imido complexes [(CbzdiphosR)Zr=NR′(X)] 5 iPrCl‐NAd and 5 PhI‐NTMS, respectively. Reaction of 2 iPrCl with azobenzene led to N−N bond scission giving 6 iPrCl, in which one of the NPh‐fragments is coupled with the carbazole nitrogen to form a central η2‐bonded hydrazide(−1), whereas the other NPh‐fragment binds to zirconium acting as an imido‐ligand. Finally, addition of pyridine to 2 iPrCl yielded the dark purple complex [(CbzdiphosiPr)Zr(bpy)Cl] (7 iPrCl) through a combination of CH‐activation and C−C‐coupling. The structural data and UV/Vis spectroscopic properties of 7 iPrCl indicate that the bpy (bipyridine) may be regarded as a (dianionic) diamido‐type ligand.
Chemical Synthesis of Human Insulin‐Like Peptide‐6
Authors: Wu Fangzhou , Mayer John P. , Zaykov Alexander N. , Zhang Fa , Liu Fa , DiMarchi Richard D. 
Published: June 2016

AbstractHuman insulin‐like peptide‐6 (INSL‐6) belongs to the insulin superfamily and shares the distinctive disulfide bond configuration of human insulin. In this report we present the first chemical synthesis of INSL‐6 utilizing fluorenylmethyloxycarbonyl‐based (Fmoc) solid‐phase peptide chemistry and regioselective disulfide bond construction protocols. Due to the presence of an oxidation‐sensitive tryptophan residue, two new orthogonal synthetic methodologies were developed. The first method involved the identification of an additive to suppress the oxidation of tryptophan during iodine‐mediated S‐acetamidomethyl (Acm) deprotection and the second utilized iodine‐free, sulfoxide‐directed disulfide bond formation. The methodologies presented here offer an efficient synthetic route to INSL‐6 and will further improve synthetic access to other multiple‐disulfide‐containing peptides with oxidation‐sensitive residues.
How a Thermally Unstable Metal Hydrido Complex Can Yield High Catalytic Activity Even at Elevated Temperatures
Authors: Ehm Christian , Krüger Juliane , Lentz Dieter 
Published: June 2016

AbstractDespite their instability in ethereal solvents, organotitanium hydride catalysts are successfully employed in catalysis at moderate to high temperatures (110 °C), even in the presence of alcohols. It is shown computationally (bond dissociation energy (BDE) analysis and energetic profile for regeneration) and experimentally (EPR studies and kinetic studies), with the specific example of hydrodefluorination (HDF), that despite the long standing belief, regeneration of Ti−H bonds from Ti−F bonds using silanes is endergonic. The resulting low concentration of Ti−H species is crucial for the catalytic stability of those systems. The resting state in the catalysis is a Ti−F species. The most promising silanes for regeneration are not the ones that have the strongest Si−F bond, but the ones that show the largest difference in Si−F and Si−H BDEs.