bluuebunny/crossref_metadata_2025_split huggingface dataset:
Versatile Synthesis of Luminescent Tetradentate Cyclometalated Alkynylgold(III) Complexes and Their Application in Solution‐Processable Organic Light‐Emitting Devices
Authors: Wong Ben Yiu‐Wing , Wong Hok‐Lai , Wong Yi‐Chun , Chan Mei‐Yee , Yam Vivian Wing‐Wah 
Published: November 2016

AbstractA new class of cyclometalated tetradentate alkynylgold(III) complexes has been successfully synthesized by post‐synthetic modification. Through the judicious design and choice of pincer ligands, post‐synthetic cyclization could be achieved to produce the robust and structurally rigid class of tetradentate gold(III) C^N^C^C complexes with high photoluminescence quantum yields of up to 0.49 in solution and 0.78 in doped thin films at room temperature, at least an order of magnitude higher than those of the structurally related uncyclized tridentate alkynylgold(III) analogues. High‐performance yellow to orange‐red emitting solution‐processable organic light‐emitting devices have also been achieved with external quantum efficiency of 11.1 %. This work describes for the first time of the use of post‐synthetic ligand modification approach to overcome the synthetic challenge for tetradentate alkynylgold(III) complexes.
An Integrated Mass Spectrometry Based Approach to Probe the Structure of the Full‐Length Wild‐Type Tetrameric p53 Tumor Suppressor
Authors: Arlt Christian , Flegler Vanessa , Ihling Christian H. , Schäfer Mathias , Thondorf Iris , Sinz Andrea 
Published: November 2016

AbstractWe present an integrated approach for investigating the topology of proteins through native mass spectrometry (MS) and cross‐linking/MS, which we applied to the full‐length wild‐type p53 tetramer. For the first time, the two techniques were combined in one workflow to obtain not only structural insight in the p53 tetramer, but also information on the cross‐linking efficiency and the impact of cross‐linker modification on the conformation of an intrinsically disordered protein (IDP). P53 cross‐linking was monitored by native MS and as such, our strategy serves as a quality control for different cross‐linking reagents. Our approach can be applied to the structural investigation of various protein systems, including IDPs and large protein assemblies, which are challenging to study by the conventional methods used for protein structure characterization.
Compressibility of woven textiles on the architecture of a highly ordered cylindrical, orthogonal, hollow‐channeled scaffolds
Authors: Santos‐Esteve Laura , Berna Àngel 
Published: November 2016

ABSTRACTScaffolds that mimic the architecture of native tissues are highly desirable for tissue engineering. Because some human tissues, such as nerves and teeth, have an oriented microscale structure, the control of the scaffold design parameters is important. In this study, we fabricated micro‐oriented structures with different interpenetrating networks by combining thermal compression, sintering, solvent casting, and particulate leaching techniques. The influence of the processing parameters, such as the compaction pressure, number of stacked fabric layers, and compression time on the structure, pore morphology, porosity, and thickness was studied. Increases in the compacting pressure resulted in changes in the pores morphology; when the pores changed from circular to elliptical cylindrical channels, the porosity reached its maximum. A further increase in the pressure resulted in a slight decrease in the porosity because of the collapse of the elliptical cylindrical channels and the shift in the pore channels from orthogonal assembly to lamellar structure. On the other hand, the scaffold thickness could be controlled by the adjustment of the compaction pressure and/or the number of stacked fabric layers. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44616.
Bis(phenothiazyl‐ethynylene)‐Based Organic Dyes Containing Di‐Anchoring Groups with Efficiency Comparable to N719 for Dye‐Sensitized Solar Cells
Authors: Siu Chi‐Ho , Lee Lawrence Tien Lin , Ho Po‐Yu , Ho Cheuk‐Lam , Chen Tao , Suramitr Songwut , Hannongbua Supa , Xie Zhiyuan , Wei Mingdeng , Wong Wai‐Yeung 
Published: November 2016

AbstractA new series of acetylene‐bridged phenothiazine‐based di‐anchoring dyes have been synthesized, fully characterized, and used as the photoactive layer for the fabrication of conventional dye‐sensitized solar cells (DSSCs). Tuning of their photophysical and electrochemical properties using different π‐conjugated aromatic rings as the central bridges has been demonstrated. This molecular design strategy successfully inhibits the undesirable charge recombination and prolongs the electron lifetime significantly to improve the power conversion efficiency (η), which was proven by the detailed studies of electrochemical impedance spectroscopy (EIS) and open‐circuit voltage decay (OCVD). Under a standard air mass (AM) 1.5 irradiation (100 mW cm−2), the DSSC based on the dye with phenyl bridging unit exhibits the highest η of 7.44 % with open‐circuit photovoltage (Voc) of 0.796 V, short‐circuit photocurrent density (Jsc) of 12.49 mA cm−2 and fill factor (ff) of 0.748. This η value is comparable to that of the benchmark N719 under the same conditions.
Insights into the Difference Between Rotaxane and Pseudorotaxane
Authors: Sun He‐Lue , Zhang Heng‐Yi , Dai Zhen , Han Xu , Liu Yu 
Published: November 2016

AbstractRotaxane and pseudorotaxane are two types of mechanically interlocked molecular architectures, and there is a clear topological difference and boundary between them. In this work, a “suggested [2]rotaxane 1⊂α‐CD” was constructed based on axle molecule 1 bearing two terminal ferrocene groups and a wheel component α‐cyclodextrin (α‐CD), but the result obtained indicated that the ferrocene group cannot prevent α‐CD dethreading under UV irradiation. That is, 1⊂α‐CD is just a pseudo[2]rotaxane. Furthermore, the two ferrocene groups in 1⊂α‐CD were encapsulated by two cucurbit[7]uril (CB[7]) units to obtain a heteropseudo[4]rotaxane 1⊂α‐CD⋅2CB[7]. This heteropseudo[4]rotaxane displayed high stability towards harsh temperatures and the isomerization of azobenzene in 1, so it can be regarded as a [2]rotaxane. In this [2]rotaxane, the stoppers are not the bulky groups covalently bonded to the axle, but the cyclic CB[7] units connected through noncovalent interactions.
Plasma diagnostics in two kinematic classes of CMEs observed by the Atmospheric Imaging Assembly onboard the Solar Dynamic Observatory
Authors: Chmielewska E. , Tomczak M. , Kołomański S. , Mrozek T. 
Published: November 2016

AbstractIn order to study the dynamics and thermal properties of two kinematic classes of coronal mass ejections (CMEs) we analyzed two well‐observed events in the early stage of their propagation, using multiwavelength observations from the Atmospheric Imaging Assembly (AIA) of the Solar Dynamic Observatory (SDO). For deriving differential emission measure (DEM) profiles and DEM maps of the basic structures of CMEs, we used two methods: the regularized inversion and the iterative forward–fitting approach. For the CME associated with a M2.0 class flare (CME‐FL), we identified a hot, moving, blob‐like feature which seems to be a candidate for a CME flux rope. Furthermore, an expanding system of loop and coronal dimming was clearly seen in AIA images. For the CME related to an eruptive prominence (CME–EP), we observed an eruptive plasmoid and a failed‐eruption of cold plasma. However, we also recognized warm and hot moving signatures that revealed a multi‐temperature nature of the eruptive prominence. Our main results are as follows: (a) An analysis of the examples of the two different kinematic classes of CMEs shows that despite the slight variations in the values of speeds and accelerations (CME‐FL: v ≈ 174 km s–1, a ≈ 350 ms–2; CME‐EP: v ≈ 135 km s–1, a ≈ 160 ms–2) they present the same kinematic behavior; (b) in the field of view of the LASCO coronagraphs these two events have the similar, positive accelerations; (c) for both events we observed an impulsive acceleration phase (IAP); (d) the expanding structures seen in 171 Å, 193 Å, 211 Å in both events move faster than the hotter blobs; (e) the plasmoid core for the CME‐FL is hot (8.0–15.8 MK); (f) the expanding blob and the hot structure in the prominence region for the CME–EP event have the similar temperature range (0.8–2.5 MK). (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hybrid simulations of chromospheric HXR flare sources
Authors: Moravec Z. , Varady M. , Kašparová J. , Kramoliš D. 
Published: November 2016

AbstractRecent measurements of vertical extents and positions of the chromospheric hard X‐ray (HXR) flare sources based on Ramaty High‐Energy Spectroscopic Imager (RHESSI) observations show a significant inconsistency with the theoretical predictions based on the standard collisional thick target model (CTTM). Using the hybrid flare code Flarix, we model simultaneously and self‐consistently the propagation, scattering and energy losses of electron beams with power‐law energy spectra and various initial pitch‐angle distributions in a purely collisional approximation and concurrently the dynamic response of the heated chromosphere on timescales typical for RHESSI image reconstruction. The results of the simulations are used to model the time evolution of the vertical distribution of chromospheric HXR source within a singular (compact) loop. Adopting the typical RHESSI imaging times scales, energy dependent vertical sizes and positions as could be observed by RHESSI are presented. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
NLTE modeling of a small active region filament observed with the VTT
Authors: Schwartz P. , Balthasar H. , Kuckein C. , Koza J. , Gömöry P. , Rybák J. , Heinzel P. , Kučera A. 
Published: November 2016

AbstractAn active region mini‐filament was observed with the Vacuum Tower Telescope (VTT) in Tenerife simultaneously in the Hei infrared triplet using the Tenerife Infrared Polarimeter 1 (TIP 1), in Hα with the TESOS Fabry‐Pérot interferometer, and in Caii 8542 Å with the VTT spectrograph. The spectropolarimetric data were inverted using the HAZEL code and Hα profiles were modelled by solving a NLTE radiative transfer in a simple isobaric and isothermal 2D slab irradiated both from its bottom and sides from the solar surface. It was found that the mini‐filament is composed of horizontal fluxtubes, along which the cool plasma of T ∼ 10000 K can flow with very large, even supersonic, velocities. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Multi‐spectral observations of flares
Authors: Zuccarello F. 
Published: November 2016

AbstractObservations show that during solar flares radiation can be emitted across the entire electromagnetic spectrum, spanning from gamma rays to radio waves. These emissions, related to the conversion of magnetic energy into other forms of energy (kinetic, thermal, waves) through magnetic reconnection, are due to different physical processes that can occur in different layers of the Sun. This means that flare observations need to be carried out using instruments operating in different wave‐bands in order to achieve a complete scenario of the processes going on. Taking into account that most of the radiative energy is emitted at optical and UV wavelengths, observations carried out from space, need to be complemented by observations carried out from ground‐based telescopes. Nowadays, the possibility to carry on high temporal, spatial and spectral resolution from ground‐based telescopes in coordinated campaigns with space‐borne instruments (like, i.e., IRIS and HINODE) gives the opportunity to investigate the details of the flare emission at different wavelengths and can provide useful hints to understand these phenomena and compare observations with models. However, it is undoubted that sometimes the pointing to the flaring region is not an easy task, due to the necessity to provide the target coordinates to satellites with some hours in advance. Some problems arising from this issue will be discussed. Moreover, new projects related to flare catalogues and archives will be presented. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solar physics at the Einstein Tower
Authors: Denker C. , Heibel C. , Rendtel J. , Arlt K. , Balthasar H. , Diercke A. , González Manrique S.J. , Hofmann A. , Kuckein C. , Önel H. , Senthamizh Pavai V. , Staude J. , Verma M. 
Published: November 2016

AbstractThe solar observatory Einstein Tower (Einsteinturm) at the Telegrafenberg in Potsdam is both a landmark of modern architecture and an important place for solar physics. Originally built for high‐resolution spectroscopy and measuring the gravitational redshift, research shifted over the years to understanding the active Sun and its magnetic field. Nowadays, telescope and spectrographs are used for research and development, i.e., testing instruments and in particular polarization optics for advanced instrumentation deployed at major European and international astronomical and solar telescopes. In addition, the Einstein Tower is used for educating and training of the next generation astro‐physicists as well as for education and public outreach activities directed at the general public. This article comments on the observatory's unique architecture and the challenges of maintaining and conserving the building. It describes in detail the characteristics of telescope, spectrographs, and imagers; it portrays some of the research and development activities. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Helical kink instability in the confined solar eruption on 2002 May 27
Authors: Hassanin A. , Kliem B. , Seehafer N. 
Published: November 2016

AbstractThis paper presents an improved MHD modeling of the confined filament eruption in solar active region NOAA 9957 on 2002 May 27 by extending the parametric studies of the event in Török & Kliem (2005) and Hassanin & Kliem (2016). Here the initial flux rope equilibrium is chosen to possess a small apex height identical to the observed initial filament height, which implies a more realistic inclusion of the photospheric line tying. The model matches the observations as closely as in the preceding studies, with the closest agreement again being obtained for an initial average flux rope twist of about 4π. Thus, the model for strongly writhing confined solar eruptions, which assumes that a kink‐unstable flux rope in the stability domain of the torus instability exists at the onset of the eruption's main acceleration phase, is further substantiated. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Flow and magnetic field properties in the trailing sunspots of active region NOAA 12396
Authors: Verma M. , Denker C. , Böhm F. , Balthasar H. , Fischer C. E. , Kuckein C. , Bello González N. , Berkefeld T. , Collados M. , Diercke A. , Feller A. , González Manrique S. J. , Hofmann A. , Lagg A. , Nicklas H. , Orozco Suárez D. , Pator Yabar A. , Rezaei R. , Schlichenmaier R. , Schmidt D. , Schmidt W. , Sigwarth M. , Sobotka M. , Solanki S. K. , Soltau D. , Staude J. , Strassmeier K. G. , Volkmer R. , von der Lühe O. , Waldmann T. 
Published: November 2016

AbstractImproved measurements of the photospheric and chromospheric three‐dimensional magnetic and flow fields are crucial for a precise determination of the origin and evolution of active regions. We present an illustrative sample of multiinstrument data acquired during a two‐week coordinated observing campaign in August 2015 involving, among others, the GREGOR solar telescope (imaging and near‐infrared spectroscopy) and the space missions Solar Dynamics Observatory (SDO) and Interface Region Imaging Spectrograph (IRIS). The observations focused on the trailing part of active region NOAA 12396 with complex polarity inversion lines and strong intrusions of opposite polarity flux. The GREGOR Infrared Spectrograph (GRIS) provided Stokes IQUV spectral profiles in the photospheric Si I λ 1082.7 nm line, the chromospheric He I λ 1083.0 nm triplet, and the photospheric Ca I λ 1083.9 nm line. Carefully calibrated GRIS scans of the active region provided maps of Doppler velocity and magnetic field at different atmospheric heights. We compare quick‐look maps with those obtained with the “Stokes Inversions based on Response functions” (SIR) code, which furnishes deeper insight into the magnetic properties of the region. We find supporting evidence that newly emerging flux and intruding opposite polarity flux are hampering the formation of penumbrae, i.e., a penumbra fully surrounding a sunspot is only expected after cessation of flux emergence in proximity to the sunspots. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Secondary prophylactic treatment and long‐term prognosis after TIA and different subtypes of stroke. A 25‐year follow‐up hospital‐based observational study
Authors: Eriksson Sven‐Erik 
Published: November 2016

AbstractObjectivesTo assess long‐term prognosis after transient ischemic attack (TIA)/subtypes of stroke relative to secondary prophylactic treatment(s) given.Materials and MethodsRetro/prospective follow‐up of patients hospitalized in the Stroke Unit or in the Department of Neurology, Linköping, in 1986 and followed up to Feb. 2011.ResultsA total of 288 men were followed up for 2254 years (mean 7.8 years) and 261 women for 1984 years (mean 7.6 years). In men, the distribution to anticoagulants (AC) (warfarin treatment) was 18%, antiplatelet therapy (APT) usually ASA 75 mg/day 54%, untreated 27%, unknown 2%. In women, the distribution to AC was 15%, APT 60%, untreated 23%, unknown 2%, respectively. Mortality rates at 1 year, 10 years, and 25 years for men were 21%, 67%, and 93%, respectively, versus the rates in women of 24%, 71%, and 90%, respectively. Survival curves showed markedly increased risk of death compared to the normal population. AC treatment was more favorable for men regarding the annual risk of stroke, compared with APT (9.4% vs. 9.8%), as well as the risks of MI, (5.6% vs. 6.7%), and death (8.1% vs. 10.3%), compared to women for stroke (11.6% vs. 8.8%) and MI (5.3% vs. 3.7%) but not for death (8.3% vs. 8.4%). The risk of fatal bleeding was 0.86% annually on AC compared to 0.17% on APT. According to Cox regression analysis included patients with TIA/ischemic stroke, first‐line treatment had beneficial effects on survival: AC OR 0.67 (0.5–0.9), APT 0.67 (0.52–0.88) versus untreated.ConclusionsPatients with a history of TIA/stroke had a higher mortality rate versus controls, providing support for both primary and secondary prophylaxis regarding vascular risk factors for death. This study also provided support for secondary prophylactic treatment with either AC or ASA (75 mg once daily) to reduce the vascular risk of death unless there are contraindications.
Can Caring Create Prejudice? An Investigation of Positive and Negative Intergenerational Contact in Care Settings and the Generalisation of Blatant and Subtle Age Prejudice to Other Older People
Authors: Drury Lisbeth , Abrams Dominic , Swift Hannah J. , Lamont Ruth A. , Gerocova Katarina 
Published: November 2016

AbstractCaring is a positive social act, but can it result in negative attitudes towards those cared for, and towards others from their wider social group? Based on intergroup contact theory, we tested whether care workers' (CWs) positive and negative contact with old‐age care home residents (CHRs) predicts prejudiced attitudes towards that group, and whether this generalises to other older people. Fifty‐six CWs were surveyed about their positive and negative contact with CHRs and their blatant and subtle attitudes (humanness attributions) towards CHRs and older adults. We tested indirect paths from contact with CHRs to attitudes towards older adults via attitudes towards CHRs. Results showed that neither positive nor negative contact generalised blatant ageism. However, the effect of negative, but not positive, contact on the denial of humanness to CHRs generalised to subtle ageism towards older adults. This evidence has practical implications for management of CWs' work experiences and theoretical implications, suggesting that negative contact with a subgroup generalises the attribution of humanness to superordinate groups. Because it is difficult to identify and challenge subtle prejudices such as dehumanisation, it may be especially important to reduce negative contact. © 2016 The Authors. Journal of Community & Applied Social Psychology Published by John Wiley & Sons Ltd.
Structural Rearrangement from Oligomer to Fibril Detected with FRET in a Designed Amphiphilic Peptide
Authors: Chi Heng , Keiderling Timothy A. 
Published: November 2016

Abstractβ‐Sheet conformation is promoted in peptides with amphiphilic design, and stable β‐turn formation is favored with the unnatural amino acid d‐Pro followed by a flexible residue such as Gly. A 19‐residue peptide (B3) was synthesized with alternating hydrophobic and hydrophilic residues connected by symmetrical d‐Pro‐Gly and Gly‐d‐Pro turns. B3 forms an oligomeric aggregate, rich in β‐sheet conformation, that reversibly transforms into an unordered structure on heating, as evidenced by its temperature‐dependent IR spectra. When a dansyl moiety was added to the N terminus of B3, the resulting peptide (B3D) can convert into a fibrillar structure after higher temperature incubation, as detected spectroscopically as well as by TEM. The fibrillization process involves an initial unfolding step monitored by the quenching of dansyl emission; in contrast, subsequent enhanced thioflavin T emission is seen on its binding to the fibril. A possible mechanism is proposed: B3D forms a low‐temperature oligomer, which is at least partially unfolded by heat and subsequently reassembles more slowly as a fibril.
Iterative Nonproteinogenic Residue Incorporation Yields α/β‐Peptides with a Helix–Loop–Helix Tertiary Structure and High Affinity for VEGF
Authors: Checco James W. , Gellman Samuel H. 
Published: November 2016

AbstractInhibition of specific protein–protein interactions is attractive for a range of therapeutic applications, but the large and irregularly shaped contact surfaces involved in many such interactions make it challenging to design synthetic antagonists. Here, we describe the development of backbone‐modified peptides containing both α‐ and β‐amino acid residues (α/β‐peptides) that target the receptor‐binding surface of vascular endothelial growth factor (VEGF). Our approach is based on the Z‐domain, which adopts a three‐helix bundle tertiary structure. We show how a two‐helix “mini‐Z‐domain” can be modified to contain β and other nonproteinogenic residues while retaining the target‐binding epitope by using iterative unnatural residue incorporation. The resulting α/β‐peptides are less susceptible to proteolysis than is their parent α‐peptide, and some of these α/β‐peptides match the full‐length Z‐domain in terms of affinity for receptor‐recognition surfaces on the VEGF homodimer.
Active Site Crowding of Cytochrome P450 3A4 as a Strategy To Alter Its Selectivity
Authors: Schiavini Paolo , Cheong Kin J. , Moitessier Nicolas , Auclair Karine 
Published: November 2016

AbstractSubstrate‐promiscuous enzymes are a promising starting point for the development of versatile biocatalysts. In this study, human cytochrome P450 3A4, known for its ability to metabolise hundreds of drugs, was engineered to alter its regio‐ and stereoselectivity. Rational mutagenesis was used to introduce steric hindrance in a specific manner in the large active site of P450 3A4 and to favour oxidation at a more sterically accessible position on the substrate. Hydroxylation of a synthetic precursor of (R)‐lisofylline, a compound under investigation for its anti‐inflammatory properties, was chosen as a first proof‐of‐principle application of our protein engineering strategy. In a second example, increasing active site crowding led to an incremental shift in the selectivity of oxidation from an internal double bond to a terminal phenyl group in a derivative of theobromine. The same correlation between crowding and selectivity was found in a final case focused on the hydroxylation of the steroid sex hormone progesterone.