bluuebunny/crossref_metadata_2025_split huggingface dataset:
Filaggrin Peptides with β‐Hairpin Structure Bind Rheumatoid Arthritis Antibodies
Authors: Fischer Sabrina , Geyer Armin 
Published: March 2014

AbstractIn the early detection of rheumatoid arthritis (RA) synthetic filaggrin peptides serve as antigens for rheumatoid‐specific autoantibodies (anti‐citrullinated peptide antibody, ACPA) in ELISA tests. In this work we present a peptide that exhibits the binding epitope of ACPA in the form of a stable folding β‐hairpin. The homogeneity of the peptide folding was confirmed by NMR spectroscopy and might lead to the first proposed structure of the antibody‐bound conformation of the epitope.
Practical Metal‐Free C(sp3)H Functionalization: Construction of Structurally Diverse α‐Substituted N‐Benzyl and N‐Allyl Carbamates
Authors: Xie Zhiyu , Liu Lei , Chen Wenfang , Zheng Hongbo , Xu Qingqing , Yuan Huiqing , Lou Hongxiang 
Published: March 2014

AbstractDescribed is a practical and universal CH functionalization of readily removable N‐benzyl and N‐allyl carbamates, with a wide range of nucleophiles at ambient temperature promoted by Ph3CClO4. The metal‐free reaction has an excellent functional‐group tolerance, and displays a broad scope with respect to both N‐carbamates and nucleophile partners (a variety of organoboranes and CH compounds). The synthetic utility in target‐ as well as diversity‐oriented syntheses is demonstrated.
Iron‐Catalyzed C(sp2)H and C(sp3)H Arylation by Triazole Assistance
Authors: Gu Qing , Al Mamari Hamad H. , Graczyk Karolina , Diers Emelyne , Ackermann Lutz 
Published: March 2014

AbstractModular 1,2,3‐triazoles enabled iron‐catalyzed CH arylations with broad scope. The novel triazole‐based bidentate auxiliary is easily accessible in a highly modular fashion and allowed for user‐friendly iron‐catalyzed C(sp2)H functionalizations of arenes and alkenes with excellent chemo‐ and diastereoselectivities. The versatile iron catalyst also proved applicable for challenging C(sp3)H functionalizations, and proceeds by an organometallic mode of action. The triazole‐assisted CH activation strategy occurred under remarkably mild reaction conditions, and the auxiliary was easily removed in a traceless fashion. Intriguingly, the triazole group proved superior to previously used auxiliaries.
First High‐resolution GPR and Magnetic Archaeological Prospection at the Viking Age Settlement of Birka in Sweden
Authors: Trinks Immo , Neubauer Wolfgang , Hinterleitner Alois 
Published: March 2014

ABSTRACTIn May 2006 high‐resolution measurements using ground‐penetrating radar (GPR) and magnetic gradiometer systems conducted over selected areas at the site of the Viking Age settlement and trading place Birka in central Sweden demonstrated the suitability of these methods for archaeological prospection of Scandinavian proto‐urban settlements. The non‐invasive geophysical surveys revealed numerous structural details of the settlement: houses, property boundaries, track‐ways, buried remains of the town ramparts dating from different building periods, including a gate, were mapped with a manually operated single‐channel GPR system and a four‐channel magnetometer array. The combination of these two prospection methods, state‐of‐the‐art data processing and visualization and archaeological interpretation within a geographical information system resulted in valuable new information about the UNESCO World Cultural Heritage Site Birka‐Hovgården. We present methodology and results of this first archaeological prospection case study conducted in 2006. Copyright © 2014 John Wiley & Sons, Ltd.
Site‐Selective Protein Immobilization through 2‐Cyanobenzothiazole‐Cysteine Condensation
Authors: Wang Hsiao‐Chan , Yu Ching‐Ching , Liang Chien‐Fu , Huang Li‐De , Hwu Jih‐Ru , Lin Chun‐Cheng 
Published: March 2014

AbstractWe described a rapid site‐selective protein immobilization strategy on glass slides and magnetic nanoparticles, at either the N or C terminus, by a 2‐cyanobenzothiazole (CBT)‐cysteine (Cys) condensation reaction. A terminal cysteine was generated at either terminus of a target protein by a combination of expressed protein ligation (EPL) and tobacco etch virus protease (TEVp) digestion, and was reacted with the CBT‐solid support to immobilize the protein. According to microarray analysis, we found that glutathione S‐transferase immobilized at the N terminus allowed higher substrate binding than for immobilization at the C terminus, whereas there were no differences in the activities of N‐ and C‐terminally immobilized maltose‐binding proteins. Moreover, immobilization of TEVp at the N terminus preserved higher activity than immobilization at the C terminus. The success of utilizing CBT‐Cys condensation and the ease of constructing a terminal cysteine using EPL and TEVp digestion demonstrate that this method is feasible for site‐selective protein immobilization on glass slides and nanoparticles. The orientation of a protein is crucial for its activity after immobilization, and this strategy provides a simple means to evaluate the preferred protein immobilization orientation on solid supports in the absence of clear structural information.
Dinuclear Zinc–N‐Heterocyclic Carbene Complexes for Either the Controlled Ring‐Opening Polymerization of Lactide or the Controlled Degradation of Polylactide Under Mild Conditions
Authors: Fliedel Christophe , Vila‐Viçosa Diogo , Calhorda Maria José , Dagorne Samuel , Avilés Teresa 
Published: March 2014

AbstractWe describe the synthesis of the new Zn–N‐heterocyclic carbene (NHC) alkoxide complexes [(S,CNHC)ZnCl(OBn)]2 (5) and [(O,CNHC)ZnCl(OBn)]2 (6) for use as ring‐opening polymerization (ROP) initiators for lactide polymerization. Complexes 5 and 6 are readily available through an alcoholysis reaction between BnOH and the corresponding Zn–NHC ethyl species [(S,CNHC)ZnCl(Et)] (3) and [(O,CNHC)ZnCl(Et)] (4), and species 3 and 4 were obtained from the reaction of ZnEt2 with the N‐methyl‐N'‐ethylphenylsulfide (1⋅HCl) and N‐methyl‐N'‐ethylmethylether (2⋅HCl) imidazolium salts, respectively. Both solution and solid‐state structural data for Zn benzyloxide species 5 and 6 agree with dimeric structures under the studied conditions (reaction conditions: CH2Cl2 or THF, room temperature). A computational analysis of species 3 and 4 supports a dimeric structure in solution. The ZnII alkoxide species 5 and 6 were found to mediate either the ROP of lactide (in an effective and controlled manner) to produce chain length‐controlled polylactide (PLA) or, in the presence of an alcohol source such as MeOH, the controlled degradation of PLA through extensive transesterification reactions to afford methyl lactate as the major product. A thorough DFT computational analysis of the ROP of lactide initiated by complex 5 was performed, which revealed that the operating coordination–insertion mechanism was assisted by the second Zn center, leading to a lower‐energy ROP process; this result may be of interest for the future design of well‐defined and high‐performance metal‐based catalysts.
Electrochemiluminescence Detection of TNT by Resonance Energy Transfer through the Formation of a TNT–Amine Complex
Authors: Qi Wenjing , Xu Min , Pang Lei , Liu Zhongyuan , Zhang Wei , Majeed Saadat , Xu Guobao 
Published: March 2014

Abstract2,4,6‐Trinitrotoluene (TNT) is a widely used nitroaromatic explosive with significant detrimental effects on the environment and human health. Its detection is of great importance. In this study, both electrochemiluminescence (ECL)‐based detection of TNT through the formation of a TNT–amine complex and the detection of TNT through electrochemiluminescence resonance energy transfer (ECRET) are developed for the first time. 3‐Aminopropyltriethoxysilane (APTES)‐modified [Ru(phen)3]2+ (phen=1,10‐phenanthroline)‐doped silica nanoparticles (RuSiNPs) with uniform sizes of (73±3) nm were synthesized. TNT can interact with APTES‐modified RuSiNPs through charge transfer from electron‐rich amines in the RuSiNPs to the electron‐deficient aromatic ring of TNT to form a red TNT–amine complex. The absorption spectrum of this complex overlaps with the ECL spectrum of the APTES‐modified RuSiNPs/triethylamine system. As a result, ECL signals of the APTES‐modified RuSiNPs/triethylamine system are turned off in the presence of TNT owing to resonance energy transfer from electrochemically excited RuSiNPs to the TNT–amine complex. This ECRET method has been successfully applied for the sensitive determination of TNT with a linear range from 1×10−9 to 1×10−6 M with a fast response time within 1 min. The limit of detection is 0.3 nM. The method exhibits good selectivity towards 2,4‐dinitrotoluene, p‐nitrotoluene, nitrobenzene, phenol, p‐quinone, 8‐hydroxyquinoline, p‐phenylenediamine, K3[Fe(CN)6], Fe3+, NO3−, NO2−, Cr3+, Fe2+, Pb2+, SO32−, formaldehyde, oxalate, proline, and glycine.
A “Distorted‐BODIPY”‐Based Fluorescent Probe for Imaging of Cellular Viscosity in Live Cells
Authors: Zhu Hao , Fan Jiangli , Li Miao , Cao Jianfang , Wang Jingyun , Peng Xiaojun 
Published: March 2014

AbstractCellular viscosity is a critical factor in governing diffusion‐mediated cellular processes and is linked to a number of diseases and pathologies. Fluorescent molecular rotors (FMRs) have recently been developed to determine viscosity in solutions or biological fluid. Herein, we report a “distorted‐BODIPY”‐based probe BV‐1 for cellular viscosity, which is different from the conventional “pure rotors”. In BV‐1, the internal steric hindrance between the meso‐CHO group and the 1,7‐dimethyl group forced the boron–dipyrrin framework to be distorted, which mainly caused nonradiative deactivation in low‐viscosity environment. BV‐1 gave high sensitivity (x=0.62) together with stringent selectivity to viscosity, thus enabling viscosity mapping in live cells. Significantly, the increase of cytoplasmic viscosity during apoptosis was observed by BV‐1 in real time.
Dual Catalysis Sees the Light: Combining Photoredox with Organo‐, Acid, and Transition‐Metal Catalysis
Authors: Hopkinson Matthew N. , Sahoo Basudev , Li Jun‐Long , Glorius Frank 
Published: March 2014

AbstractThe photoredox activation of organic substrates with visible light is a powerful methodology that generates reactive radical species under very mild conditions. When combined with another catalytic process in a dual catalytic system, novel, visible‐light‐promoted transformations have been realized that do not proceed using either catalyst in isolation. In this minireview, the state of the art in organic reactions mediated by dual catalytic systems merging photoredox activation with organo‐, acid or metal catalysis is discussed.
Synthesis, Anti‐tubulin and Antiproliferative SAR of Steroidomimetic Dihydroisoquinolinones
Authors: Leese Mathew P. , Jourdan Fabrice L. , Major Meriel R. , Dohle Wolfgang , Thomas Mark P. , Hamel Ernest , Ferrandis Eric , Mahon Mary F. , Newman Simon P. , Purohit Atul , Potter Barry V. L. 
Published: March 2014

AbstractA SAR translation strategy adopted for the discovery of tetrahydroisoquinolinone (THIQ)‐based steroidomimetic microtubule disruptors has been extended to dihydroisoquinolinone (DHIQ)‐based compounds. A steroid A,B‐ring‐mimicking DHIQ core was connected to methoxyaryl D‐ring mimics through methylene, carbonyl, and sulfonyl linkers, and the resulting compounds were evaluated against two cancer cell lines. The carbonyl‐linked DHIQs in particular exhibit significant in vitro antiproliferative activities (e.g., 6‐hydroxy‐7‐methoxy‐2‐(3,4,5‐trimethoxybenzoyl)‐3,4‐dihydroisoquinolin‐1(2H)‐one (16 g): GI50 51 nM in DU‐145 cells). The broad anticancer activity of DHIQ 16 g was confirmed in the NCI 60‐cell line assay giving a mean activity of 33 nM. Furthermore, 6‐hydroxy‐2‐(3,5‐dimethoxybenzoyl)‐7‐methoxy‐3,4‐dihydroisoquinolin‐1(2H)‐one (16 f) and 16 g and their sulfamate derivatives 17 f and 17 g (2‐(3,5‐dimethoxybenzoyl)‐7‐methoxy‐6‐sulfamoyloxy‐3,4‐dihydroisoquinolin‐1(2H)‐one and 7‐methoxy‐2‐(3,4,5‐trimethoxybenzoyl)‐6‐sulfamoyloxy‐3,4‐dihydroisoquinolin‐1(2H)‐one, respectively) show excellent activity against the polymerization of tubulin, close to that of the clinical combretastatin A‐4, and bind competitively at the colchicine binding site of tubulin. Compounds 16 f and 17 f were also shown to demonstrate in vitro anti‐angiogenic activity. Additionally, X‐ray and computational analyses of 17 f reveal that electrostatic repulsion between the two adjacent carbonyl groups, through conformational biasing, dictates the adoption of a “steroid‐like” conformation that may partially explain the excellent in vitro activities.
Bis‐(1,2,3,4‐tetrahydroisoquinolinium): A Chiral Scaffold for Developing High‐Affinity Ligands for SK Channels
Authors: Liégeois Jean‐François , Wouters Johan , Seutin Vincent , Dilly Sébastien 
Published: March 2014

AbstractN‐Methyl‐bis‐(1,2,3,4‐tetrahydroisoquinolinium) analogues derived from AG525 (1,1′‐(propane‐1,3‐diyl)‐bis‐(6,7‐dimethoxy‐2‐methyl‐1,2,3,4‐tetrahydroisoquinoline)) stereoisomers and tetrandrine, a rigid bis‐(1,2,3,4‐tetrahydroisoquinoline) analogue with an S,S configuration, were synthesized and tested for their affinity for small‐conductance calcium‐activated potassium channel (SK/KCa2) subtypes using radioligand binding assays. A significant increase in affinity was observed for the quaternized analogues over the parent 1,2,3,4‐tetrahydroisoquinoline compounds. Interestingly, the impact of stereochemistry was not the same in the two groups of compounds. For quaternized analogues, affinities of S,S and R,R isomers for SK2 and SK3 channels were similar and in both cases higher than that of the meso derivative. Among the bis‐tetrahydroisoquinoline compounds, the S,S isomers exhibited high affinity, while the R,R and meso isomers had similarly lower affinities. Furthermore, the SK2/SK3 selectivity ratio was slightly increased for quaternized analogues. Bis‐(1,2,3,4‐tetrahydroisoquinolinium) represents a new scaffold for the development of high‐affinity ligands for SK channel subtypes.
Multi‐scale finite element analyses for stress and strain evaluations of braid fibril artificial blood vessel and smooth muscle cell
Authors: Nakamachi Eiji , Uchida Takahiro , Kuramae Hiroyuki , Morita Yusuke 
Published: March 2014

SUMMARYIn this study, we developed a multi‐scale finite element (FE) analysis code to obtain the stress and strain that occurred in the smooth muscle cell (SMC) at micro‐scale, which was seeded in the real fabricated braid fibril artificial blood vessel. This FE code can predict the dynamic response of stress under the blood pressure loading. We try to establish a computer‐aided engineering (CAE)‐driven scaffold design technique for the blood vessel regeneration.Until now, there occurred the great progresses for the endothelial cell activation and intima layer regeneration in the blood vessel regeneration study. However, there remains the difficulty of the SMC activation and media layer regeneration. Therefore, many researchers are now studying to elucidate the fundamental mechanism of SMC activation and media layer regeneration by using the biomechanical technique. As the numerical tool, we used the dynamic‐explicit FE code PAM‐CRASH, ESI Ltd. For the material models, the nonlinear viscoelastic constitutive law was adapted for the human blood vessel, SMC and the extra‐cellular matrix, and the elastic law for the polyglycolic acid (PGA) fiber. Through macro‐FE and micro‐FE analyses of fabricated braid fibril tubes by using PGA fiber under the combined conditions of the orientation angle and the pitch of fiber, we searched an appropriate structure for the stress stimulation for SMC functionalization.Objectives of this study are indicated as follows:

to analyze the stress and strain of the human blood vessel and SMC, and
to calculate stress and strain of the real fabricated braid fibril artificial blood vessel and SMC to search an appropriate PGA fiber structure under combined conditions of PGA fiber numbers, 12 and 24, and the helical orientation angles of fiber, 15, 30, 45, 60, and 75 degrees.Finally, we found a braid fibril tube, which has an angle of 15 degree and 12 PGA fibers, as a most appropriate artificial blood vessel for SMC functionalization.Copyright © 2014 John Wiley & Sons, Ltd.
Test/retest and inter‐test agreement of color aptitude measures
Authors: Anderson Andrew J , Johnston Alan W 
Published: March 2014

AbstractThe color discrimination capacity of color vision normal observers can be assessed using color aptitude tests (CATs), although data on the test/retest reliability and inter‐test agreement of such tests using appropriate statistical measures is limited. In this study, 32 color vision normal observers twice performed each of five CATs, being the Farnsworth‐Munsell 100 hue test, HVC Color Vision Skills Test, inter‐Society Color Council Color Aptitude Test, the Nagel Anomaloscope (Nagel), and a custom designed two‐color discrimination test. Two methods of determining the Nagel matching range were used based on the initially accepted matching range or on repeated measures. The test/retest performance of each test was determined using the method outlined by Bland and Altman[Lancet 1986;1:307–310] and the inter‐test agreement was analyzed using the same method, after converting test scores into z score units. No test was found to have a significant systematic alteration in test performance between test and retest. Test/retest performance was generally poor, indicating that tests can only reliably classify observers into very broad performance bands. All tests failed to show inter‐test agreement, and our data indicate a primary reason for this: as test/retest performance is generally poor, inter‐test agreement must also be poor as no test can agree more with another test than it agrees with itself. © 2014 Wiley Periodicals, Inc. Col Res Appl, 40, 224–231, 2015
Free Carrier Generation in Organic Photovoltaic Bulk Heterojunctions of Conjugated Polymers with Molecular Acceptors: Planar versus Spherical Acceptors
Authors: Nardes Alexandre M. , Ferguson Andrew J. , Wolfer Pascal , Gui Kurt , Burn Paul L. , Meredith Paul , Kopidakis Nikos 
Published: March 2014

AbstractA comparative study of the photophysical performance of the prototypical fullerene derivative PC61BM with a planar small‐molecule acceptor in an organic photovoltaic device is presented. The small‐molecule planar acceptor is 2‐[{7‐(9,9‐di‐n‐propyl‐9H‐fluoren‐2‐yl)benzo[c][1,2,5]thiadiazol‐4‐yl}methylene]malononitrile, termed K12. We discuss photoinduced free charge‐carrier generation and transport in blends of PC61BM or K12 with poly(3‐n‐hexylthiophene) (P3HT), surveying literature results for P3HT:PC61BM and presenting new results on P3HT:K12. For both systems we also review previous work on film structure and correlate the structural and photophysical results. In both cases, a disordered mixed phase is formed between P3HT and the acceptor, although the photophysical properties of this mixed phase differ markedly for PC61BM and K12. In the case of PC61BM the mixed phase acts as a free carrier generation region that can efficiently shuttle carriers to the pure polymer and fullerene domains. As a result, the vast majority of excitons quenched in P3HT:PC61BM blends yield free carriers detected by the contactless time‐resolved microwave conductivity (TRMC) method. In contrast, approximately 85 % of the excitons quenched in P3HT:K12 do not result in free carriers over the nanosecond timescale of the TRMC experiment. We attribute this to poor electron‐transport properties in the mixed P3HT:K12 phase. We propose that the observed differences can be traced to the respective shapes of PC61BM and K12: the three‐dimensional nature of the fullerene cage facilitates coupling between PC61BM molecules irrespective of their relative orientation, whereas for K12 strong electronic coupling is only expected for molecules oriented with their π systems parallel to each other. Comparison between the eutectic compositions of the P3HT:PC61BM and P3HT:K12 shows that the former contains enough fullerene to form a percolation pathway for electrons, whereas the latter contains a sub‐percolating volume fraction of the planar acceptor. Furthermore, the planar K12 co‐assembles with P3HT into a disordered, glassy phase that partly accounts for the poor electron‐transport properties, and may also enhance recombination due to the strong intermolecular interactions between the donor and the acceptor. The implication for the performance of organic photovoltaic devices with the two acceptors is also discussed.
Electronic Structure of N2P2 Four‐Membered Rings
Authors: Escudero Daniel , Frontera Antonio , Streubel Rainer 
Published: March 2014

AbstractThe biradicaloid character of the ground‐state structures of N2P2 rings is studied by using the high‐level ab initio multiconfigurational CASPT2/CASSCF method. In order to obtain accurate descriptors, we combine two criteria: 1) singlet–triplet energy gaps and 2) relative values of the occupation numbers for bonding and antibonding orbitals associated with the radical sites. The singlet–triplet energy gaps, the occupation numbers of antibonding‐like orbitals, and the weights of the main configuration state functions (CSFs) of the ground‐state wavefunctions, that is, Ψ(1A1), are used to derive the biradicaloid character that ranges from 10–15 %.
Syntheses of Biodiesel Precursors: Sulfonic Acid Catalysts for Condensation of Biomass‐Derived Platform Molecules
Authors: Balakrishnan Madhesan , Sacia Eric R. , Bell Alexis T. 
Published: March 2014

AbstractSynthesis of transportation fuel from lignocellulosic biomass is an attractive solution to the green alternative‐energy problem. The production of biodiesel, in particular, involves the process of upgrading biomass‐derived small molecules to diesel precursors containing a specific carbon range (C11–C23). Herein, a carbon‐upgrading process utilizing an acid‐catalyzed condensation of furanic platform molecules from biomass is described. Various types of sulfonic acid catalysts have been evaluated for this process, including biphasic and solid supported catalysts. A silica‐bound alkyl sulfonic acid catalyst has been developed for promoting carbon–carbon bond formation of biomass‐derived carbonyl compounds with 2‐methylfuran. This hydrophobic solid acid catalyst exhibits activity and selectivity that are comparable to those of a soluble acid catalyst. The catalyst can be readily recovered and recycled, possesses appreciable hydrolytic stability in the presence of water, and retains its acidity over multiple reaction cycles. Application of this catalyst to biomass‐derived platform molecules led to the synthesis of a variety of furanic compounds, which are potential biodiesel precursors.
Base‐Free, One‐Pot Chemocatalytic Conversion of Glycerol to Methyl Lactate using Supported Gold Catalysts
Authors: Pazhavelikkakath Purushothaman Rajeesh Kumar , van Haveren Jacco , Melián‐Cabrera Ignacio , van Eck Ernst R. H. , Heeres Hero J. 
Published: March 2014

AbstractWe report an efficient one‐pot conversion of glycerol (GLY) to methyl lactate (MLACT) in methanol in good yields (73 % at 95 % GLY conversion) by using Au nanoparticles on commercially available ultra‐stable zeolite‐Y (USY) as the catalyst (160 °C, air, 47 bar pressure, 0.25 M GLY, GLY‐to‐Au mol ratio of 1407, 10 h). The best results were obtained with zeolite USY‐600, a catalyst that has both Lewis and Brønsted sites. This methodology provides a direct chemo‐catalytic route for the synthesis of MLACT from GLY. MLACT is stable under the reaction conditions, and the Au/USY catalyst was recycled without a decrease in the activity and selectivity.