bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single‐Crystal X‐ray Diffraction Structure of the Stable Enol Tautomer Polymorph of Barbituric Acid at 224 and 95 K
Authors: Marshall Madalynn G. , Lopez‐Diaz Valerie , Hudson Bruce S. 
Published: December 2015

AbstractThe thermodynamically stable enol crystal form of barbituric acid, previously prepared as powder by grinding or slurry methods, has been obtained as single crystals by slow cooling from methanol solution. The selection of the enol crystal was facilitated by a density‐gradient method. The structure at 224 and 95 K confirms the enol inferred on the basis of powder data. The enol has bond lengths that are consistent with the expected bond order and with DFT calculations that include treatment of hydrogen bonding. In isolation, the enol is higher in energy than the tri‐keto form by 50 kJ mol−1 which must be more than compensated by enhanced hydrogen bonding. Both crystal forms have four normal H‐bonds; the enol has two additional H‐bonds with O–O distances of 2.49 Å. Conversion into the enol form occurs spontaneously in the solid state upon prolonged storage of the commercial tri‐keto material. Slurry conversion of tri‐one to enol in ethanol is reversed in direction in ethanol‐D1.
Synthesis, Properties, and Two‐Dimensional Adsorption Characteristics of 5‐Amino[6]hexahelicene
Authors: van der Meijden Maarten W. , Gelens Edith , Quirós Natalia Murillo , Fuhr Javier D. , Gayone J. Esteban , Ascolani Hugo , Wurst Klaus , Lingenfelder Magalí , Kellogg Richard M. 
Published: December 2015

AbstractA convergent synthesis of racemic 5‐amino[6]hexahelicene is described. Cross‐coupling reactions are used to assemble a pentacyclic framework, and a metal‐catalyzed ring‐closure comprises the final step. The enantiomers were separated by means of chromatography and the absolute configurations were assigned by comparison of the CD spectra with hexahelicene. The t1/2 value for racemization at 210 °C was approximately 1 hour. Scanning tunneling microscopy (STM) measurements were carried out on enantiopure and racemic samples of aminohelicene on Au(111) under ultrahigh vacuum (UHV) conditions.
Progress in Polyarsolyl Chemistry
Authors: Heindl Claudia , Peresypkina Eugenia V. , Virovets Alexander V. , Balázs Gábor , Scheer Manfred 
Published: December 2015

AbstractThe synthesis of heteroatom analogues of the cyclopentadienyl anion Cp− is a fascinating and challenging field of research. The replacement of methine moieties by phosphorus is well investigated for the synthesis of mono‐, tri‐ and pentaphospholyl ligands. On the other hand, arsenic derivatives are rare and 1,2,4‐triarsolyl and tetraarsolyl salts are unknown. Herein, we report on the synthesis of Cs[E3C2(trip)2] (1 a: E=P; 1 b: E=As; trip=2,4,6‐triisopropylphenyl) and Cs[E4C(trip)] (2 a: E=P; 2 b: E=As). Compound 1 b represents the first 1,2,4‐triarsolyl and 2 b the first tetraarsolyl anion. All salts are obtained in one‐pot syntheses using E(SiMe3)3, 2,4,6‐triisopropylbenzoyl chloride and CsF. The products 1 a⋅2 C4H8O2, 2 a⋅Et2O and 2 b⋅3 C4H8O2 were characterized by X‐ray structural analysis, which revealed planar heterocycles. Nucleus‐independent chemical shifts (NICS) confirmed the aromaticity of these anions. Notably, compound 2 a⋅Et2O is only the second tetraphospholyl ligand which is structurally characterized.
Comparing social entrepreneurship across nations: An exploratory study of institutional effects
Authors: Puumalainen Kaisu , Sjögrén Helena , Syrjä Pasi , Barraket Jo 
Published: December 2015

AbstractInstitutional and cultural contexts shape social entrepreneurship differently. This paper explores the roles of culture, socioeconomic development, and governance institutions on the prevalence of social entrepreneurship. The empirical results are based on Global Entrepreneurship Monitor data, including 49 countries across the globe. The results indicate that the negative effect of the level of development holds for entrepreneurial activity in general, but there is no such effect on social entrepreneurship. Of Hofstede's () cultural dimensions, power distance is negatively related to all types of entrepreneurship, and Inglehart's () secular‐rational values are positively related to established entrepreneurship. Self‐expressive values relate positively with established social entrepreneurship. The results imply that the existence of social problems and/or market failures does not result in higher levels of social entrepreneurship unless the formal institutions are sufficiently developed. Copyright © 2015 ASAC. Published by John Wiley & Sons, Ltd.
An algorithm for estimating radial gas holdup profiles in bubble columns from chordal densitometry measurements
Authors: Yadav Ashutosh , Kushwaha Ashish , Roy Shantanu 
Published: December 2015

Abstractγ‐ray densitometry (also referred to as “column scanning” in industrial troubleshooting applications) is a non‐invasive, simple, and relatively inexpensive technique for measuring time‐averaged holdup profiles in multiphase flow systems. Most often, the projection data measured in densitometry is “chordal,” and not “radial,” owing to limitations of experimentation, particularly in challenging industrial environments. However, most of the theory of design and scale‐up is based on “radial profiles” of phase holdups and velocity. The inter‐conversion of chordal profiles to radial profiles is non‐trivial and often prone to error propagation, particularly when the number of projection scans is small.In this work, we propose an algorithm for estimating radial gas holdup profiles, which is not subject to error propagation since we use only the direct (forward) Abel transformation process. Details of the algorithm are discussed. As a test case, γ‐ray densitometry experiments performed on a bubble column are presented.
Chiral Cobalt(III) Complexes as Bifunctional Brønsted Acid–Lewis Base Catalysts for the Preparation of Cyclic Organic Carbonates
Authors: Rulev Yuri A. , Larionov Vladimir A. , Lokutova Anastasia V. , Moskalenko Margarita A. , Lependina Ol'ga L. , Maleev Victor I. , North Michael , Belokon Yuri N. 
Published: December 2015

AbstractStereochemically inert cationic cobalt(III) complexes were shown to be one‐component catalysts for the synthesis of cyclic carbonates from epoxides and carbon dioxide at 50 °C and 5 MPa carbon dioxide pressure. The optimal catalyst possessed an iodide counter anion and could be recycled. A catalytic cycle is proposed in which the ligand of the cobalt complexes acts as a hydrogen‐bond donor, activating the epoxide towards ring opening by the halide anion and activating the carbon dioxide for subsequent reaction with the halo‐alkoxide. No kinetic resolution was observed when terminal epoxides were used as substrates, but chalcone oxide underwent kinetic resolution.
Directional Energy Transfer in Nanocrystals of [Ru(2,2′‐bipyridine)3]­[NaCr(oxalate)3]
Authors: Previtera Elia , Tissot Antoine , Hauser Andreas 
Published: December 2015

AbstractSize‐controlled nanocrystals (140 and 670 nm) and microcrystals (2.5 μm) of the three‐dimensional oxalate network [Ru(bpy)3][NaCr(ox)3] (ox = oxalate, bpy = 2,2′‐bipyridine) were prepared by the reverse micelle technique. The photophysical properties of the [Cr(ox)3]3– chromophores in the nanocrystals at low temperatures are significantly different from those of the same chromophore in 4 μm crystallites prepared by fast precipitation. For the latter, the absorption in the region of the R lines of the 4A2→2E transition is characterized by a sharp doublet. For the nanocrystals, the inhomogeneous broadening of the two lines is considerably larger and they have tails on the low‐energy side. The 4 μm crystallites at low temperatures show equally sharp emission from the R1 line, whereas the emission intensity from the nanocrystallites is shifted into the low‐energy tail. Time‐resolved fluorescence line‐narrowing spectra and luminescence decay curves demonstrate that this is due to efficient directional energy migration from the center of the nanocrystals towards the surface.
When and how forgiving benefits victims: Post‐transgression offender effort and the mediating role of deservingness judgements
Authors: Strelan Peter , McKee Ian , Feather N. T. 
Published: December 2015

AbstractFor all the well‐established benefits of forgiveness for victims, when and how is forgiving more likely to be beneficial? Three experimental studies found that forgiving is more likely to be beneficial when victims perceived reparative effort by offenders such that offenders deserve forgiveness. Deservingness judgements were elicited by manipulating post‐transgression offender effort (apology/amends). When offenders apologized (Study 1; recall paradigm) or made amends (Study 2; hypothetical paradigm) and were forgiven—relative to transgressors who did not apologize/make amends but were still forgiven—forgiving was beneficial. These findings—that deserved forgiveness is more beneficial for victims than undeserved forgiveness—were replicated when forgiving itself was also manipulated (Study 3). Moreover, Study 3 provided evidence to indicate that if a victim forgives when it is not deserved, victim well‐being is equivalent to not forgiving at all. Of theoretical and practical importance is the mediating effect of deservingness on relations between post‐transgression offender effort and a victim's personal consequences of forgiving.
Oxidative Stress and Antioxidant Levels in Patients with Anorexia Nervosa after Oral Re‐alimentation: A Systematic Review and Exploratory Meta‐analysis
Authors: Solmi Marco , Veronese Nicola , Luchini Claudio , Manzato Enzo , Sergi Giuseppe , Favaro Angela , Santonastaso Paolo , Correll Christoph U. 
Published: December 2015

AbstractOxidative stress markers seem to be higher in patients with anorexia nervosa (AN) than healthy controls, but the potentially beneficial effects of weight gain is not known. We calculated random effects standardised mean differences (SMDs) as effect size measures of oxidative stress marker changes after re‐alimentation reported in two or more studies, summarising others descriptively. Seven longitudinal studies (n = 104) were included. After a median follow‐up period of 8 weeks, AN patients significantly increased their body mass index (15.1 ± 2.1 to 17.1 ± 2.2, p < 0.0001). This weight gain was followed by a significant increase in serum levels of the antioxidant albumin (studies = 6, SMD = 0.50, 95%CI = 0.18; 0.82, p = 0.002; I2 = 16%) and a significant decrease in the oxidative stress marker Apolipoprotein B (studies = 2, n = 19, SMD = −0.85, 95%CI = −1.53; −0.17, p = 0.01; I2 = 0). In one study, catalase and total antioxidant capacity increased, whilst superoxide dismutase significantly decreased. In conclusion, oral re‐alimentation, even without full‐weight normalisation, seems to improve oxidative stress in people with AN. Copyright © 2015 John Wiley & Sons, Ltd and Eating Disorders Association.
Accumulation of 2,4-dinitroanisole in the earthworm Eisenia fetida from chemically spiked and aged natural soils
Authors: Lotufo Guilherme R. , Coleman Jessica G. , Harmon Ashley R. , Chappell Mark A. , Bednar Anthony J. , Russell Amber L. , Smith Jared C. , Brasfield Sandra M. 
Published: December 2015

Abstract

An initiative within the US military is targeting the replacement of traditional munitions constituents with insensitive munitions to reduce the risk of accidental detonation. The bioavailability and bioaccumulative potential of the insensitive munitions compound 2,4-dinitroanisole (DNAN) to Eisenia fetida was assessed in soils with different geochemical characteristics. Prior to exposure, soils were chemically spiked with DNAN and aged for 1 wk or 29 wk. Transformation products 2- and 4-amino-nitroanisole (2A-4NAN and 4A-2NAN) occurred in aged soils and their porewater but never at concentrations higher than the residual DNAN. The sum of DNAN, 2A-4NAN, and 4A-2NAN (sumDNAN) in soil decreased with aging, likely by irreversible binding. Both clay and organic matter contents of the soil appeared to affect the bioavailability of DNAN. The sumDNAN body residues of earthworms approached apparent steady state after 1 d and remained relatively constant through to day 7. Higher concentrations of 2A-4NAN and 4A-2NAN measured in worm tissues relative to those in soil suggest reductive transformation of DNAN in the tissues. Mean bioaccumulation factors (ratio of tissue to soil concentrations) varied from 1.2 to 4.3, whereas mean bioconcentration factors (ratio of tissue to porewater concentrations) ranged from 1.4 to 3.2. Porewater seems to play a significant role in the accumulation of DNAN in earthworms, consistent with equilibrium partitioning theory. The concentration of DNAN in soil porewater could serve as an indicator of bioavailability as well as a predictor of the concentration of that compound in earthworms. Environ Toxicol Chem 2016;35:1835–1842. Publlished 2015 SETAC. This article is a US Government work, and as such, is in the public domain in the United States of America.
Experimental determination of wettability and heterogeneity effect on CO2 distribution in porous media
Authors: Lv Pengfei , Liu Yu , Jiang Lanlan , Song Yongchen , Wu Bohao , Zhao Jiafei , Zhang Yi 
Published: December 2015

Abstract:The geological sequestration of carbon dioxide (CO2) is considered a promising technology for CO2 emissions. However, accurate estimation of the storage capacity for CO2 remains a challenge owing to the effect of capillary pressure variation. The CO2‐salty aqueous contact angle and sub‐core scale heterogeneity are the major factors that influence capillary pressure. This paper reports the results of CO2/brine two‐phase flow experiments in porous media by using an X‐ray computed tomography (CT) technique at 40°C and 8 Mpa and examines the strong influence of wettability and sub‐core scale heterogeneities on the spatial distribution of CO2. Gas injection experiments were conducted at flow rates of 0.1 mL/min, 0.2 mL/min, and 0.5 mL/min, and the porous media were packed with feldspar, quartz, or dolomite. This study indicates that at the core scale, the wettability of porous media is a crucial factor in determining CO2 saturation. Capillary fingering and low CO2 saturation occurred with high water wettability. Sub‐core scale heterogeneities controlled the CO2 distribution and saturation variation along the porous media, particular that with small pore sizes. © 2015 Society of Chemical Industry and John Wiley & Sons, Ltd
Activation of local inhibitory circuits in the dentate gyrus by adult‐born neurons
Authors: Drew Liam J. , Kheirbek Mazen A. , Luna Victor M. , Denny Christine A. , Cloidt Megan A. , Wu Melody V. , Jain Swati , Scharfman Helen E. , Hen René 
Published: December 2015

ABSTRACTRobust incorporation of new principal cells into pre‐existing circuitry in the adult mammalian brain is unique to the hippocampal dentate gyrus (DG). We asked if adult‐born granule cells (GCs) might act to regulate processing within the DG by modulating the substantially more abundant mature GCs. Optogenetic stimulation of a cohort of young adult‐born GCs (0 to 7 weeks post‐mitosis) revealed that these cells activate local GABAergic interneurons to evoke strong inhibitory input to mature GCs. Natural manipulation of neurogenesis by aging—to decrease it—and housing in an enriched environment—to increase it—strongly affected the levels of inhibition. We also demonstrated that elevating activity in adult‐born GCs in awake behaving animals reduced the overall number of mature GCs activated by exploration. These data suggest that inhibitory modulation of mature GCs may be an important function of adult‐born hippocampal neurons. © 2015 Wiley Periodicals, Inc.
Diurnal dynamics of streamflow in an upland forested micro‐watershed during short precipitation‐free periods is altered by tree sap flow
Authors: Deutscher Jan , Kupec Petr , Dundek Peter , Holík Ladislav , Machala Martin , Urban Josef 
Published: December 2015

AbstractDiurnal variations in streamflow are becoming acknowledged as a way of analysing how changing climatic conditions and land use affects watersheds but also as a way to understand watersheds as a whole. Yet not many studies from uplands below 900 mm mean annual precipitation zone are available from European countries. During the 2012 growing season, a sampling campaign took place in an upland forested micro‐watershed, Czech Republic (65 ha). Tree sap flow, rainfall and temperature were measured continuously, while streamflow at the discharge point and soil moisture were estimated from short‐term measurements. Short precipitation‐free periods lasting several days were identified for evaluation of trends in diurnal dynamics of both sap flow and streamflow. The results demonstrated that during these periods, the main factor altering streamflow was almost exclusively tree sap flow. A decrease in streamflow was observed during the day and an increase at night. The decline in sap flow after sunset was accompanied by a continuous increase in streamflow throughout the night up to its initial maximum in the morning. The amplitude in diurnal variations reached 18%. The observed time lag between the diurnal variations of sap flow and streamflow was approximately 2 h. Relatively low changes in diurnal dynamics of streamflow pointed out a strong regulatory role of the forest in buffering water discharge from the catchment. Copyright © 2015 John Wiley & Sons, Ltd.
Synthesis of Pyranopyrazoles Using Magnetically Recyclable Heterogeneous Iron Oxide‐silica Core‐shell Nanocatalyst
Authors: Soleimani Ebrahim , Jafarzadeh Mohammad , Norouzi Parastoo , Dayou Jedol , Sipaut Coswald Stephen , Mansa Rachel Fran , Saei Parisa 
Published: December 2015

AbstractThe Fe3O4@SiO2 core‐shell nanocatalyst were prepared and efficiently used for four‐component coupling reaction of aromatic aldehydes, malononitrile, ethyl acetoacetate and hydrazine hydrate in water/ethanol mixture. Various aromatic aldehydes possessing electron‐withdrawing and electron‐donating groups in different positions on the ring were successfully transformed to substituted pyranopyrazoles in high yields in short time. The nanocatalyst was easily recovered, and reused five times without significant loss in cata‐ lytic activity and performance. The structure, size and morphology of the nanosized catalyst were studied by various techniques such as Fourier transform infrared spectroscopy, powder X‐ray diffraction, dynamic light scattering and transmission electron microscopy.
Enhanced Cellular Activity in Gelatin‐Poly(Ethylene Glycol) Hydrogels without Compromising Gel Stiffness
Authors: Hoang Thi Thai Thanh , Lee Jung Seok , Lee Yunki , Park Kyung Min , Park Ki Dong 
Published: December 2015

Adhesion and proliferation of cells are often suppressed in rigid hydrogels as gel stiffness induces mechanical stress to embedded cells. Herein, the composite hydrogel systems to facilitate high cellular activities are described, while maintaining relatively high gel stiffness. This unusual property is obtained by harmonizing gelatin‐poly(ethylene glycol)‐tyramine (GPT, semisynthetic polymer) and gelatin‐hydroxyphenyl propionic acid conjugates (GH, natural polymer) into hydrogels. A minimum GH concentration of 50% is necessary for cells to be proliferative. GPT is utilized to improve biological stability (>1 week) and gelation time (<20 s) of the hydrogels. These results suggest that deficiency in cellular activity driven by gel stiffness could be overcome by finely tuning the material properties in the microenvironments.image
Convergence theory of exact interpolation scheme for computing several eigenvectors
Authors: Pultarová I. 
Published: December 2015

SummaryAn asymptotic convergence analysis of a new multilevel method for numerical solution of eigenvalues and eigenvectors of symmetric and positive definite matrices is performed. The analyzed method is a generalization of the original method that has recently been proposed by R. Kužel and P. Vaněk (DOI: 10.1002/nla.1975) and uses a standard multigrid prolongator matrix enriched by one full column vector, which approximates the first eigenvector. The new generalized eigensolver is designed to compute
eigenvectors. Their asymptotic convergence in terms of the generalized residuals is proved, and its convergence factor is estimated. The theoretical analysis is illustrated by numerical examples. Copyright © 2015 John Wiley & Sons, Ltd.
Domiciliary noninvasive positive airway pressure therapy in children
Authors: Amin Reshma , Al‐Saleh Suhail , Narang Indra 
Published: December 2015

SUMMARYThere has been a dramatic increase in the past few decades in the number of children receiving noninvasive positive airway pressure (PAP) therapy at home. Although PAP therapy was first prescribed for children with obstructive sleep apnea, the indications have rapidly widened to include treatment for central hypoventilation syndromes, neuromuscular and chest wall disorders as well as primary respiratory diseases. Given the rapidly expanding use of PAP therapy in children, pediatric pulmonologists need to be familiar with the indications, technical and safety considerations as well as potential complications and challenges that may arise when caring for children using PAP therapy. This review article covers the definition of PAP therapy, modes, interfaces, devices, indications, contraindications, suggested settings, complications as well as the factors influencing the adherence. Pediatr Pulmonol. 2016;51:335–348. © 2015 Wiley Periodicals, Inc.
Diagnostic assays for polyomavirus JC and progressive multifocal leukoencephalopathy
Authors: White Martyn K. , Sariyer Ilker K. , Gordon Jennifer , Delbue Serena , Pietropaolo Valeria , Berger Joseph R. , Khalili Kamel 
Published: December 2015

SummaryProgressive multifocal leukoencephalopathy (PML) is a devastating and often fatal demyelinating disease of the central nervous system for which effective therapies are lacking. It is caused by the replication of polyomavirus JC (JCV) in the oligodendrocytes and astrocytes leading to their cytolytic death and loss of myelin from the subcortical white matter. While the virus is very common in human populations worldwide, the incidence of the disease is very low and confined almost exclusively to individuals with some form of immunological dysfunction. However, the number of people who constitute the at‐risk population is growing larger and includes individuals with HIV‐1/AIDS and patients receiving immunomodulatory therapies such as multiple sclerosis patients treated with natalizumab. Further adding to the public health significance of this disease are the difficulties encountered in the diagnosis of PML and the lack of useful biomarkers for PML progression. In this review, we examine the diagnostic assays that are available for different aspects of the JCV life cycle, their usefulness and drawbacks, and the prospects for improvements. Copyright © 2015 John Wiley & Sons, Ltd.