bluuebunny/crossref_metadata_2025_split huggingface dataset:
Cation‐Dependent Stabilization of Electrogenerated Naphthalene Diimide Dianions in Porous Polymer Thin Films and Their Application to Electrical Energy Storage
Authors: DeBlase Catherine R. , Hernández‐Burgos Kenneth , Rotter Julian M. , Fortman David J. , dos S. Abreu Dieric , Timm Ronaldo A. , Diógenes Izaura C. N. , Kubota Lauro T. , Abruña Héctor D. , Dichtel William R. 
Published: September 2015

AbstractPorous polymer networks (PPNs) are attractive materials for capacitive energy storage because they offer high surface areas for increased double‐layer capacitance, open structures for rapid ion transport, and redox‐active moieties that enable faradaic (pseudocapacitive) energy storage. Here we demonstrate a new attractive feature of PPNs—the ability of their reduced forms (radical anions and dianions) to interact with small radii cations through synergistic interactions arising from densely packed redox‐active groups, only when prepared as thin films. When naphthalene diimides (NDIs) are incorporated into PPN films, the carbonyl groups of adjacent, electrochemically generated, NDI radical anions and dianions bind strongly to K+, Li+, and Mg2+, shifting the formal potentials of NDI’s second reduction by 120 and 460 mV for K+ and Li+‐based electrolytes, respectively. In the case of Mg2+, NDI’s two redox waves coalesce into a single two‐electron process with shifts of 240 and 710 mV, for the first and second reductions, respectively, increasing the energy density by over 20 % without changing the polymer backbone. In contrast, the formal reduction potentials of NDI derivatives in solution are identical for each electrolyte, and this effect has not been reported for NDI previously. This study illustrates the profound influence of the solid‐state structure of a polymer on its electrochemical response, which does not simply reflect the solution‐phase redox behavior of its monomers.
Function‐Led Design of Aerogels: Self‐Assembly of Alloyed PdNi Hollow Nanospheres for Efficient Electrocatalysis
Authors: Cai Bin , Wen Dan , Liu Wei , Herrmann Anne‐Kristin , Benad Albrecht , Eychmüller Alexander 
Published: September 2015

AbstractOne plausible approach to endow aerogels with specific properties while preserving their other attributes is to fine‐tune the building blocks. However, the preparation of metallic aerogels with designated properties, for example catalytically beneficial morphologies and transition‐metal doping, still remains a challenge. Here, we report on the first aerogel electrocatalyst composed entirely of alloyed PdNi hollow nanospheres (HNSs) with controllable chemical composition and shell thickness. The combination of transition‐metal doping, hollow building blocks, and the three‐dimensional network structure make the PdNi HNS aerogels promising electrocatalysts for ethanol oxidation. The mass activity of the Pd83Ni17 HNS aerogel is 5.6‐fold higher than that of the commercial Pd/C catalyst. This work expands the exploitation of the electrocatalysis properties of aerogels through the morphology and composition control of its building blocks.
Alkaline‐Earth‐Catalyzed Dehydrocoupling of Amines and Boranes
Authors: Liptrot David J. , Hill Michael S. , Mahon Mary F. , Wilson Andrew S. S. 
Published: September 2015

AbstractDehydrocoupling reactions between the boranes HBpin and 9‐borabicyclo[3.3.1]nonane and a range of amines and anilines ensue under very mild reaction conditions in the presence of a simple β‐diketiminato magnesium n‐butyl precatalyst. The facility of the reactions is suggested to be a function of the Lewis acidity of the borane substrate, and is dictated by resultant pre‐equilibria between, and the relative stability of, magnesium hydride and borohydride intermediates during the course of the catalysis.
Facile Synthesis and Properties of 2‐λ5‐Phosphaquinolines and 2‐λ5‐Phosphaquinolin‐2‐ones
Authors: Vonnegut Chris L. , Shonkwiler Airlia M. , Khalifa Muhammad M. , Zakharov Lev N. , Johnson Darren W. , Haley Michael M. 
Published: September 2015

AbstractTreatment of 2‐ethynylanilines with P(OPh)3 gives either 2,2‐diphenoxy‐2‐λ5‐phosphaquinolines or 2‐phenoxy‐2‐λ5‐phosphaquinolin‐2‐ones under transition‐metal‐free conditions. This reaction offers access to an underexplored heterocycle, which opens up the study of the fundamental nature of the NPV double bond and its potential for delocalization within a cyclic π‐electron system. This heterocycle can serve as a carbostyril mimic, with application as a bioisostere for pharmaceuticals based on the 2‐quinolinone scaffold. It also holds promise as a new fluorophore, since initial screening reveals quantum yields upwards of 40 %, Stokes shifts of 50–150 nm, and emission wavelengths of 380–540 nm. The phosphaquinolin‐2‐ones possess one of the strongest solution‐state dimerization constants for a D–A system (130 M−1) owing to the close proximity of a strong acceptor (PO) and a strong donor (phosphonamidate NH), which suggests that they might hold promise as new hydrogen‐bonding hosts for optoelectronic sensing.
Impact of Disease Duration on Vascular Surrogates of Early Atherosclerosis in Childhood‐Onset Systemic Lupus Erythematosus
Authors: Barsalou Julie , Bradley Timothy J. , Tyrrell Pascal N. , Slorach Cameron , Ng Lawrence W. K. , Levy Deborah M. , Silverman Earl D. 
Published: September 2015

ObjectiveTo determine whether longer disease duration negatively impacts carotid intima‐media thickness (CIMT), flow‐mediated dilation (FMD), and pulse wave velocity (PWV) in a cohort of patients with childhood‐onset systemic lupus erythematosus (SLE), and to compare CIMT, FMD, and PWV in patients with childhood‐onset SLE with those in healthy children and explore determinants of vascular test results in childhood‐onset SLE.MethodsCross‐sectional analysis was performed in a prospective longitudinal cohort of patients with childhood‐onset SLE at the latest followup visit. Clinical and laboratory data were collected for patients with childhood‐onset SLE. CIMT, FMD, and PWV were measured using standardized protocols in patients with childhood‐onset SLE and healthy children. Correlations between disease duration and results of the 3 vascular tests were performed. Vascular data in patients with childhood‐onset SLE were compared with those in healthy children. Multivariable linear regression was used to identify determinants of CIMT, FMD, and PWV in childhood‐onset SLE.ResultsPatients with childhood‐onset SLE (n = 149) and healthy controls (n = 178) were enrolled. The median age of the patients was 17.2 years (interquartile range [IQR] 15.7–17.9 years), and their median disease duration was 3.2 years (IQR 1.8–4.9 years). The median age of the healthy children was 14.7 years (IQR 13.1–15.9 years). Longer disease duration correlated with worse FMD (r = −0.2, P = 0.031) in patients with childhood‐onset SLE. Patients with childhood‐onset SLE had smaller (better) CIMT, higher (better) FMD, and similar PWV compared with healthy controls. Linear regression analysis explained <24% of the variation in vascular test results in patients with childhood‐onset SLE, suggesting that other variables should be explored as important determinants of CIMT, FMD, and PWV.ConclusionIn this cohort of 149 patients with childhood‐onset SLE, patients did not have worse CIMT, FMD, or PWV than did healthy controls. Longer disease duration was associated with worse FMD, suggesting progressive endothelial dysfunction over time.
Association of Acroosteolysis With Enhanced Osteoclastogenesis and Higher Blood Levels of Vascular Endothelial Growth Factor in Systemic Sclerosis
Authors: Park Jin Kyun , Fava Andrea , Carrino John , Del Grande Filippo , Rosen Antony , Boin Francesco 
Published: September 2015

ObjectiveBone resorption of distal phalanges, or acroosteolysis (AO), can develop in patients with systemic sclerosis (SSc), causing pain and functional limitation. This study was undertaken to investigate whether AO may be associated with abnormal osteoclastogenesis in SSc patients and whether hypoxia may be involved in this process.MethodsPeripheral blood mononuclear cells (PBMCs) obtained from 26 SSc patients (11 with AO and 15 without AO) and 14 healthy controls were cultured in the presence of RANKL and macrophage colony‐stimulating factor for 9 days. Tartrate‐resistant acid phosphatase–positive multinucleated giant cells (MGCs) containing 3 or more nuclei were counted as osteoclasts. Plasma levels and effects of vascular endothelial growth factor (VEGF) on osteoclast formation were evaluated.ResultsSSc patients with AO formed significantly more osteoclasts after 9 days than did patients without AO (mean ± SD 142.4 ± 67.0 versus 27.2 ± 17.6 MGCs/well; P < 0.001) or healthy controls (mean ± SD 18.7 ± 27.0 MGCs/well; P < 0.001). No significant difference in osteoclast formation was noted between the patients without AO and healthy controls. Plasma levels of VEGF were higher in SSc patients with AO compared to those without (mean ± SD 142.4 ± 69.6 pg/ml versus 88.1 ± 38.2 pg/ml; P < 0.005) or healthy controls (54.2 ± 24.6 pg/ml; P = 0.018). Priming with VEGF‐A for 24 hours significantly increased osteoclast generation by 5.3 ± 1.9 fold (P = 0.0018). The radiographic extent of AO was associated with increased osteoclast formation (Spearman's ρ = 0.741, P = 0.01).ConclusionOur findings indicate that increased osteoclast formation and higher VEGF levels may contribute to AO in SSc patients. Further studies are needed to elucidate whether targeting osteoclastogenesis may provide a specific therapeutic option for SSc‐associated AO.
Brief Report: Atypical Femoral Fracture in Rheumatoid Arthritis Patients Treated With Bisphosphonates: A Nested Case–Control Study
Authors: Koh Jung Hee , Myong Jun Pyo , Jung Seung Min , Lee Jennifer , Kwok Seung‐Ki , Park Sung‐Hwan , Ju Ji Hyeon 
Published: September 2015

ObjectiveTo examine the clinical characteristics of atypical femoral fracture (AFF) and to determine the risk factors for and clinical outcomes of AFFs in rheumatoid arthritis (RA) patients treated with bisphosphonates (BPs).MethodsA nested case–control study was conducted using data derived from the medical records of all RA patients treated with BPs at Seoul St. Mary's Hospital, a tertiary rheumatology center, from January 1, 2008 to December 31, 2014. All of the patients with RA and had been treated with BPs for at least 1 year. Ten RA patients with AFF were identified, and each of these patients (cases) was age‐ and sex‐matched with 4 RA patients without AFF (controls).ResultsFive hundred fifty‐two RA patients had BP exposure. Of the 10 with AFF, all were female (mean ± SD age 66.3 ± 8.7 years), and 90% of cases involved fracture of the proximal femur. The mean ± SD length of BP exposure in patients with AFF was 7.4 ± 3.2 years. Compared with controls, patients with AFF had a longer exposure to BPs and more often had a femorotibial angle of <175 degrees (both P < 0.001). There were no differences in RA duration, medications taken during the previous 6 months, and bone mineral density in the femur and lumbar spine between patients with and those without AFF. Multivariate logistic analyses identified longer BP exposure (odds ratio 2.386 [95% confidence interval 1.066–5.343]) as being associated with an increased risk of AFF.ConclusionRA patients who have a valgus deformity and are receiving long‐term BP treatment are at higher risk of AFF compared with matched control patients with RA. These patients should be carefully followed up with hip radiography or dual x‐ray absorptiometry.
Transient accretion disc‐like envelope in the symbiotic binary BF Cygni during its 2006–2015 optical outburst
Authors: Tomov N. A. , Tomova M. T. , Bisikalo D. V. 
Published: September 2015

AbstractThe optical light of the symbiotic binary BF Cyg during its last eruption after 2006 shows orbital variations because of an eclipse of the outbursting compact object. The first orbital minimum is deeper than the following ones. Moreover, the Balmer profiles of this system acquired additional satellite components indicating a bipolar collimated outflow at one time between the first and second orbital minima. This behaviour is interpreted in the framework of the model of a collimated stellar wind from the outbursting object. It is supposed that one extended disc‐like envelope covering the accretion disc of the compact object and collimating its stellar wind forms in the period between the first and second minima. The uneclipsed part of this envelope is responsible for the decrease of the depth of the orbital minimum. The calculated UBVRCIC fluxes of this uneclipsed part are in agreement with the observed residual of the depths of the first and second orbital minima. The parameters of the envelope require that it is the main emitting region of the line Hα but the Hα profile is less determined from its rotation and mostly from other mechanisms. It is concluded that the envelope is a transient nebular region and its destruction determines the increase of the depth of the orbital minimum with fading of the optical light. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Newly found sunspot observations by Peter Becker from Rostock for 1708, 1709, and 1710
Authors: Neuhäuser R. , Arlt R. , Pfitzner E. , Richter S. 
Published: September 2015

AbstractWe present a few newly found old sunspot observations from the years AD 1708, 1709, and 1710, which were obtained by Peter Becker from Rostock, Germany. For 1709, Becker gave a detailed drawing: he observed a sunspot group made up of two spots on January 5, 6, and 7, and just one of the two spots was observed on January 8 and 9. We present his drawing and his explanatory text. We can measure the latitude and longitude of these two spots and estimate their sizes for all five days. While the spots and groups in 1708 and the spot on four of the five days in January 1709 were known before from other observers (e.g. Hoyt & Schatten 1998), the location of the spots in early January 1709 were not known before, so that they can now be considered in reconstructed butterfly diagrams. The sunspots detected by Becker on 1709 January 5 and 1710 September 10 were not known before at all, as the only observer known for those two dates, La Hire, did not detect that spot (group). We estimate new group sunspot numbers for the relevant days, months, and years. The time around 1708–1710 is important, because it documents the recovery of solar activity towards the end of the Maunder Grand Minimum. We also show two new spot observations from G. Kirch for 1708 September 13 and 14 as described in his letter to Wurzelbaur (dated Berlin AD 1708 December 19). (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Hydrothermal liquefaction of bagasse using ethanol and black liquor as solvents
Authors: Kosinkova Jana , Ramirez Jerome A. , Nguyen Jenny , Ristovski Zoran , Brown Richard , Lin Carol S.K. , Rainey Thomas J. 
Published: September 2015

AbstractThe objective of this study was to examine the hydrothermal liquefaction of sugarcane bagasse using ethanol and black liquor (BL) in a pilot scale. Combinations of co‐solvents (ethanol/water, ethanol/BL) were studied at various concentrations and reaction conditions. The maximum oil yield of 61% was achieved with a reaction temperature of 300 °C for 30 min and using pure BL as a solvent, while the highest higher heating value (HHV) was obtained from a 50:50 ethanol‐BL mixture. The oils contained alcohols, esters, phenolic compounds, aromatics, and heterocyclics. The O/C and H/C ratios of the oil were comparable with traditional biodiesel and commercial diesel. Although this study showed there are some improvements to be made to improve the chemical composition, the approach has potential for large‐scale production of a substitute for fossil‐fuel‐based diesel. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd
Investigating the Role of Conformational Effects on Laccase Stability and Hyperactivation under Stress Conditions
Authors: Ferrario Valerio , Chernykh Alexey , Fiorindo Federica , Kolomytseva Marina , Sinigoi Loris , Myasoedova Nina , Fattor Diana , Ebert Cynthia , Golovleva Ludmila , Gardossi Lucia 
Published: September 2015

AbstractFungal laccase from Steccherinum ochraceum 1833 displays remarkable stability under different harsh conditions: organic/buffer mixtures, thermal treatment, and microwave radiation. The behavior is particularly significant in the light of the sharp inactivation observed for two different fungal laccases. Laccase from S. ochraceum 1833 also displays hyperactivation under mild thermal treatment (60 °C). Molecular dynamics simulations at 80 °C explained how this laccase retains the geometry of the electron transfer pathway, thereby assuring electron transfer through the copper ions and thus maintaining its catalytic activity at high temperature. Spectroscopic studies revealed that the thermal activation corresponds to specific conformational changes in the protein. The results indicate that this laccase is potentially applicable under denaturing conditions that might be beneficial for the biotransformation of recalcitrant substrates.
Bridging Efficiency within Multinuclear Homogeneous Catalysts in the Photocatalytic Reduction of Carbon Dioxide
Authors: Meister Simon , Reithmeier Richard O. , Ogrodnik Alexander , Rieger Bernhard 
Published: September 2015

AbstractA trinuclear complex consisting of one [Ru(dmb)3]2+ (dmb=4,4′‐dimethyl‐2,2′‐bipyridine) (Ru) and two [Re(dmb)(CO)3Cl] (Re) building blocks, [Re(CO)3Cl(dmb−dmb)Ru(dmb)(dmb−dmb)Re(CO)3Cl](PF6)2 (Re−Ru−Re), is presented. Photophysical properties of Re−Ru−Re and the individual components with different or no covalent linkages are thoroughly investigated and compared. To elucidate the role of the single covalent bonds, photocatalytic reduction of CO2 is performed with the trinuclear complex and a series of model systems featuring systematic absence of linkages between the metal centers. Photoluminescence spectra and quantum yields reveal efficient energy transfer from the excited state of Re to Ru if these fragments are covalently linked. Moreover, intramolecular electron transfer from the one‐electron reduced species of Ru to Re occurs if there is covalent bonding, leading to a higher photostability and thus the highest turnover number in photocatalytic CO2 reduction of 199 for the trinuclear complex Re−Ru−Re within the systems under investigation. Optimized experimental conditions reveal the highest turnover number (315) reported to date for ReI/RuII‐based homogeneous catalysts in photocatalytic CO2 reduction.
A Monolithic Hybrid Cellulose‐2.5‐Acetate/Polymer Bioreactor for Biocatalysis under Continuous Liquid–Liquid Conditions Using a Supported Ionic Liquid Phase
Authors: Sandig Bernhard , Michalek Lukas , Vlahovic Sandra , Antonovici Mihaela , Hauer Bernhard , Buchmeiser Michael R. 
Published: September 2015

AbstractMesoporous monolithic hybrid cellulose‐2.5‐acetate (CA)/polymer supports were prepared under solvent‐induced phase separation conditions using cellulose‐2.5‐acetate microbeads 8–14 μm in diameter, 1,1,1‐tris(hydroxymethyl)propane and 4,4′‐methylenebis(phenylisocyanate) as monomers as well as THF and n‐heptane as porogenic solvents. 4‐(Dimethylamino)pyridine and dibutyltin dilaurate (DBTDL), respectively, were used as catalysts. Monolithic hybrid supports were used in transesterification reactions of vinyl butyrate with 1‐butanol under continuous, supported ionic liquid–liquid conditions with Candida antarctica lipase B (CALB) and octylmethylimidazolium tetrafluoroborate ([OMIM+][BF4−]) immobilized within the CA beads inside the polymeric monolithic framework and methyl tert‐butyl ether (MTBE) as the continuous phase. The new hybrid bioreactors were successfully used in dimensions up to 2×30 cm (V=94 mL). Under continuous biphasic liquid–liquid conditions a constant conversion up to 96 % was achieved over a period of 18 days, resulting in a productivity of 58 μmol mg−1(CALB) min−1. This translates into an unprecedented turnover number (TON) of 3.9×107 within two weeks, which is much higher than the one obtained under standard biphasic conditions using [OMIM+][BF4−]/MTBE (TON=2.7×106). The continuous liquid–liquid setup based on a hybrid reactor presented here is strongly believed to be applicable to many other enzyme‐catalyzed reactions.
Heterolysis of H2 Across a Classical Lewis Pair, 2,6‐Lutidine⋅BCl3: Synthesis, Characterization, and Mechanism
Authors: Ginovska Bojana , Autrey Tom , Parab Kshitij , Bowden Mark E. , Potter Robert G. , Camaioni Donald M. 
Published: September 2015

AbstractWe report that 2,6‐lutidine⋅trichloroborane (Lut⋅BCl3) reacts with H2 in toluene, bromobenzene, dichloromethane, and Lut solvents producing the neutral hydride, Lut⋅BHCl2. The mechanism was modeled with density functional theory, and energies of stationary states were calculated at the G3(MP2)B3 level of theory. Lut⋅BCl3 was calculated to react with H2 and form the ion pair, [LutH+][HBCl3−], with a barrier of ΔH≠=24.7 kcal mol−1 (ΔG≠=29.8 kcal mol−1). Metathesis with a second molecule of Lut⋅BCl3 produced Lut⋅BHCl2 and [LutH+][BCl4−]. The overall reaction is exothermic by 6.0 kcal mol−1 (ΔrG°=−1.1). Alternate pathways were explored involving the borenium cation (LutBCl2+) and the four‐membered boracycle [(CH2{NC5H3Me})BCl2]. Barriers for addition of H2 across the Lut/LutBCl2+ pair and the boracycle BC bond are substantially higher (ΔG≠=42.1 and 49.4 kcal mol−1, respectively), such that these pathways are excluded. The barrier for addition of H2 to the boracycle BN bond is comparable (ΔH≠=28.5 and ΔG≠=32 kcal mol−1). Conversion of the intermediate 2‐(BHCl2CH2)‐6‐Me(C5H3NH) to Lut⋅BHCl2 may occur by intermolecular steps involving proton/hydride transfers to Lut/BCl3. Intramolecular protodeboronation, which could form Lut⋅BHCl2 directly, is prohibited by a high barrier (ΔH≠=52, ΔG≠=51 kcal mol−1).
Systematic Investigation of High‐Sensitivity Luminescent Sensing for Polyoxometalates and Iron(III) by MOFs Assembled with a New Resorcin[4]arene‐Functionalized Tetracarboxylate
Authors: Zhang Shuai‐Tong , Yang Jin , Wu Hua , Liu Ying‐Ying , Ma Jian‐Fang 
Published: September 2015

AbstractA new family of resorcin[4]arene‐based metal–organic frameworks (MOFs), namely, [Eu(HL)(DMF)(H2O)2]⋅3 H2O (1), [Tb(HL)(DMF)(H2O)2] 3 H2O (2), [Cd4(L)2(DMF)4(H2O)2] 3 H2O (3) and [Zn3(HL)2(H2O)2] 2 DMF⋅7 H2O (4), have been constructed from a new resorcin[4]arene‐functionalized tetracarboxylic acid (H4L=2,8,14,20‐tetra‐ethyl‐6,12,18,24‐tetra‐methoxy‐4,10,16,22‐tetra‐carboxy‐methoxy‐calix[4]arene). Isostructural 1 and 2 exhibit charming 1D motifs built with the cup‐like HL3− anions and rare earth cations. Compounds 3 and 4 show a unique sandwich‐based 2D layer and a fascinating 3D framework, respectively. Remarkably, compounds 1 and 2 display intensive red and green emissions triggered by the efficient antenna effect of organic ligands under UV light. More importantly, systematic luminescence studies demonstrate that Ln‐MOFs 1 and 2, as efficient multifunctional fluorescent materials, show highly selective and sensitive sensing of Fe3+, polyoxometalates (POMs), and acetone, which represents a rare example of a sensor for quantitatively detecting three different types of analytes. This is also an exceedingly rare example of Fe3+ and POMs detection in aqueous solutions employing resorcin[4]arene‐based luminescent Ln‐MOFs. Furthermore, the possible mechanism of the sensing properties is deduced.