bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fetal Growth and Preterm Birth in Children Exposed to Maternal or Paternal Rheumatoid Arthritis: A Nationwide Cohort Study
Authors: Rom Ane L. , Wu Chun S. , Olsen Jørn , Kjærgaard Hanne , Jawaheer Damini , Hetland Merete L. , Vestergaard Mogens , Mørch Lina S. 
Published: November 2014

ObjectiveTo assess indicators of fetal growth and risk of preterm birth in children of parents with rheumatoid arthritis (RA).MethodsThrough linkage of Danish national registries, we identified all children born in Denmark between 1977 and 2008. We used general linear regression models to estimate mean differences in indicators of fetal growth among children with a parent with RA compared to unexposed children. Odds ratios (ORs) and 95% confidence intervals (95% CIs) of preterm birth were calculated using a logistic regression model.ResultsOf the 1,917,723 children included, a total of 13,556 children were exposed to maternal RA or maternal preclinical RA. Children exposed to maternal RA (n = 2,101) had approximately similar length, head circumference, and abdominal circumference at birth compared with children of mothers without RA. Birth weight was 87 gm lower (mean difference −87.04 gm [95% CI −111.23, −62.84]) and placenta weight was 14 gm lower (−13.45 gm [95% CI −21.46, −5.43]) than those in children of mothers without RA. Rather similar results were found in children exposed to maternal preclinical RA (n = 11,455). Compared with unexposed children, a higher risk of preterm birth was found in children exposed to maternal RA (OR 1.48 [95% CI 1.20, 1.84]) and preclinical RA (OR 1.32 [95% CI 1.07, 1.64]). No associations were found with paternal RA.ConclusionChildren exposed to either maternal RA or maternal preclinical RA are more often born preterm. However, indicators of fetal growth measured at birth were only slightly lower than those in unexposed children.
Detailed Structure–Function Correlations of Bacillus subtilis Acetolactate Synthase
Authors: Sommer Bettina , von Moeller Holger , Haack Martina , Qoura Farah , Langner Clemens , Bourenkov Gleb , Garbe Daniel , Loll Bernhard , Brück Thomas 
Published: November 2014

AbstractIsobutanol is deemed to be a next‐generation biofuel and a renewable platform chemical.1 Non‐natural biosynthetic pathways for isobutanol production have been implemented in cell‐based and in vitro systems with Bacillus subtilis acetolactate synthase (AlsS) as key biocatalyst.2–6 AlsS catalyzes the condensation of two pyruvate molecules to acetolactate with thiamine diphosphate and Mg2+ as cofactors. AlsS also catalyzes the conversion of 2‐ketoisovalerate into isobutyraldehyde, the immediate precursor of isobutanol. Our phylogenetic analysis suggests that the ALS enzyme family forms a distinct subgroup of ThDP‐dependent enzymes. To unravel catalytically relevant structure‐function relationships, we solved the AlsS crystal structure at 2.3 Å in the presence of ThDP, Mg2+ and in a transition state with a 2‐lactyl moiety bound to ThDP. We supplemented our structural data by point mutations in the active site to identify catalytically important residues.
Particle Size Measurement of Metallic Iron in Reduced Materials Based on Optical Image Analysis
Authors: Sun Yongsheng , Han Yuexin , Gao Peng , Mu Yufan 
Published: November 2014

AbstractThe size of metallic iron particles in coal‐based reduced materials was measured by optical image analysis in three different reduced samples. The obtained data were analyzed by frequency and cumulative distribution. The results reveal that optical image analysis successfully measured the particle size of metallic iron in the reduced samples. The frequency distribution curves or cumulative passing percentage of metallic iron particles exhibit almost the same trend with respect to particle size. The quality of curve fitting indicates that the exponential decay function and Rosin‐Rammler equation represent well experimental data on frequency distribution and cumulative passing percentage, respectively.
Replacement of CH4 in Hydrate in Porous Sediments with Liquid CO2 Injection
Authors: Zhang Yu , Xiong Li‐Jun , Li Xiao‐Sen , Chen Zhao‐Yang , Xu Chun‐Gang 
Published: November 2014

AbstractThe dynamics of the replacement of CH4 in hydrate in porous sediments with liquid CO2 was investigated using a self‐developed experimental apparatus at different temperatures and initial pressures. The pressure increases steadily as the replacement reaction processes. The amount of the replaced CH4 is almost the same as that of the CO2 forming hydrate in the early stage and gradually becomes somewhat less in the later stage. The initial pressure has minor effects on the replacement rate, and temperature reduction causes a lower replacement rate. The experimental results suggest that the replacement rate is not related to the region of the temperature‐pressure conditions but is mainly affected by the fugacity differences of CH4 hydrate decomposition and CO2 hydrate formation.
Rare‐Earth‐Metal Methyl, Amide, and Imide Complexes Supported by a Superbulky Scorpionate Ligand
Authors: Schädle Dorothea , Maichle‐Mössmer Cäcilia , Schädle Christoph , Anwander Reiner 
Published: November 2014

AbstractThe reaction of monomeric [(TptBu,Me)LuMe2] (TptBu,Me=tris(3‐Me‐5‐tBu‐pyrazolyl)borate) with primary aliphatic amines H2NR (R=tBu, Ad=adamantyl) led to lutetium methyl primary amide complexes [(TptBu,Me)LuMe(NHR)], the solid‐state structures of which were determined by XRD analyses. The mixed methyl/tetramethylaluminate compounds [(TptBu,Me)LnMe({μ2‐Me}AlMe3)] (Ln=Y, Ho) reacted selectively and in high yield with H2NR, according to methane elimination, to afford heterobimetallic complexes: [(TptBu,Me)Ln({μ2‐Me}AlMe2)(μ2‐NR)] (Ln=Y, Ho). X‐ray structure analyses revealed that the monomeric alkylaluminum‐supported imide complexes were isostructural, featuring bridging methyl and imido ligands. Deeper insight into the fluxional behavior in solution was gained by 1H and 13C NMR spectroscopic studies at variable temperatures and 1H–89Y HSQC NMR spectroscopy. Treatment of [(TptBu,Me)LnMe(AlMe4)] with H2NtBu gave dimethyl compounds [(TptBu,Me)LnMe2] as minor side products for the mid‐sized metals yttrium and holmium and in high yield for the smaller lutetium. Preparative‐scale amounts of complexes [(TptBu,Me)LnMe2] (Ln=Y, Ho, Lu) were made accessible through aluminate cleavage of [(TptBu,Me)LnMe(AlMe4)] with N,N,N′,N′‐tetramethylethylenediamine (tmeda). The solid‐state structures of [(TptBu,Me)HoMe(AlMe4)] and [(TptBu,Me)HoMe2] were analyzed by XRD.
Structures and Unexpected Dynamic Properties of Phosphine Oxides Adsorbed on Silica Surfaces
Authors: Hilliard Casie R. , Kharel Sugam , Cluff Kyle J. , Bhuvanesh Nattamai , Gladysz John A. , Blümel Janet 
Published: November 2014

AbstractSolid‐state NMR spectroscopy of selected phosphine oxides adsorbed on silica surfaces establishes the surface mobilities, even of phosphine oxides with high melting points. Crystal structures of the adducts Ph3PO⋅HOSiPh3 and Cy3PO⋅H2O indicate that the interactions with silica involve hydrogen bonding of the PO group to adsorbed water and surface silanol groups.
Triple Emission from p‐Dimethylaminobenzonitrile–Cucurbit[8]uril Triggers the Elusive Excimer Emission
Authors: Sayed Mhejabeen , Biedermann Frank , Uzunova Vanya D. , Assaf Khaleel I. , Bhasikuttan Achikanath C. , Pal Haridas , Nau Werner M. , Mohanty Jyotirmayee 
Published: November 2014

AbstractThe intriguing dual‐emission behavior of p‐ dimethylaminobenzonitrile (DMABN) and the identity of the associated excited states is, arguably, the most extensively investigated and also controversially discussed molecule‐ specific phenomenon of modern photochemistry. We have now found a new, third fluorescence band when DMABN is encapsulated within the water‐soluble molecular container cucurbit[8]uril (CB8). It is centered between the previously observed emissions and assigned to the elusive excimer emission from DMABN through 1:2 CB8:DMABN complex formation. Heating of the CB8⋅(DMABN)2 complex from 0 to 100 °C results in the dissociation of the ternary complex and restoration of the dual‐emission properties of the monomer. Alternatively, monomer emission can be obtained by selecting cucurbit[7]uril (CB7), a host homologue that is too small to accommodate two DMABN molecules, or by introducing ethyl instead of methyl groups at the amino terminus of the aminobenzonitrile guest.
Asymmetric Hydrogenation of Furans and Benzofurans with Iridium–Pyridine–Phosphinite Catalysts
Authors: Pauli Larissa , Tannert René , Scheil Robin , Pfaltz Andreas 
Published: November 2014

AbstractEnantioselective hydrogenation of furans and benzofurans remains a challenging task. We report the hydrogenation of 2‐ and 3‐substituted furans by using iridium catalysts that bear bicyclic pyridine–phosphinite ligands. Excellent enantioselectivities and high conversions were obtained for monosubstituted furans with a 3‐alkyl or 3‐aryl group. Furans substituted at the 2‐position and 2,4‐disubstituted furans proved to be more difficult substrates. The best results (80–97 % conversion, 65–82 % enantiomeric excess) were obtained with monosubstituted 2‐alkylfurans and 2‐[4‐(trifluoromethyl)phenyl]furan. Benzofurans with an alkyl substituent at the 2‐ or 3‐position also gave high conversions and enantioselectivity, whereas 2‐aryl derivatives showed essentially no reactivity. The asymmetric hydrogenation of a 3‐methylbenzofuran derivative was used as a key step in the formal total synthesis of the cytotoxic naphthoquinone natural product (−)‐thespesone.
Multicolored‐Fluorescence Switching of ICT‐Type Organic Solids with Clear Color Difference: Mechanically Controlled Excited State
Authors: Zhang Yujian , Wang Kai , Zhuang Guilin , Xie Zengqi , Zhang Cheng , Cao Feng , Pan Guoxiang , Chen Haifeng , Zou Bo , Ma Yuguang 
Published: November 2014

AbstractA donor–acceptor‐type fluorophore containing a twisted diphenylacrylonitrile and triphenylamine has been developed by using the Suzuki reaction. The system indicates typical intramolecular charge‐transfer properties. Upon mechanical grinding or hydrostatic pressure, the fluorophore reveals a multicolored fluorescence switching. Interestingly, a fluorescence color transition from green to red was clearly observed, and the change of photoluminescent (PL) wavelength gets close to 111 nm. The mechanisms of high‐contrast mechanochromic behavior are fully investigated by techniques including powder XRD, PL lifetime, high‐pressure PL lifetime, and Raman spectra analysis. The tremendous PL wavelength shift is attributed to gradual transition of excited states from the local excited state to the charge‐transfer state.
Reactivity of a Stable Phosphinonitrene towards Small Molecules
Authors: Dielmann Fabian , Bertrand Guy 
Published: November 2014

AbstractThe room‐temperature stable phosphinonitrene 1 undergoes a thermal rearrangement into heterocycle 2 through a process involving a nitrene insertion into a CH bond. In the presence of acetonitrile, a nitrene–acetonitrile adduct has been isolated; then it first rearranges into a ketenimine and subsequently into a rare example of diazaphosphete. Compound 1 also splits water, carbon dioxide, carbon disulfide, and elemental sulfur, although it reacts with white phosphorus, leading to a P5N cluster formally resulting from the insertion of the PN moiety into a PP edge of the P4 tetrahedron.
Multiscale Chemical Process Design Exemplified for a PEM Fuel Cell Process
Authors: Karst Florian , Freund Hannsjörg , Maestri Matteo , Sundmacher Kai 
Published: November 2014

AbstractTo maximize the utilization of limited energy and material resources, a new design methodology for chemical processes is proposed based on a multiscale optimization approach. The different levels of the process hierarchy are presented and design aspects are discussed. The methodology is further exemplified by considering a methane steam reforming process for operation of a proton exchange membrane fuel cell (PEMFC) in an automotive application. The method delivers an optimal technically feasible process based on an integrated steam reforming reactor, operated in autothermal mode.
The Development of Zn–Ce Hybrid Redox Flow Batteries for Energy Storage and Their Continuing Challenges
Authors: Walsh Frank C. , Ponce de Léon Carlos , Berlouis Len , Nikiforidis George , Arenas‐Martínez Luis F. , Hodgson David , Hall David 
Published: November 2014

AbstractThe Zn–Ce flow battery is a recently introduced hybrid redox flow battery (RFB) but has been extensively studied in the laboratory and at the industrial pilot scale since its introduction in 2005. The cell has the highest open‐circuit cell potentials amongst aqueous RFBs, which can exceed 2.4 V at full charge. Although original patents were filed in 2004 and 2005, the history of the half‐cell reactions stretches back many decades, with the CeIV/CeIII redox couple being well studied in sulfuric acid as a redox mediator in organic electrosynthesis or in nitric acid for specialist cleaning in the chemical and nuclear industries; in addition, zinc deposition and stripping in acid media are well known in hydrometallurgy and electroplating of metals as well as in other secondary batteries using zinc negative electrodes. Methanesulfonic acid electrolytes were introduced in surface finishing several decades ago but their use in flow batteries is only 20 years old. This Review considers the thermodynamics and kinetics of the electrode reactions (desired and secondary) in each half‐cell, operational variables, materials for cell components, cell design and performance of the zinc–cerium flow battery. Continuing challenges are highlighted and critical research needs for the science and technological development are considered.
Influence of hyporheic exchange, substrate distribution, and other physically linked hydrogeomorphic characteristics on abundance of freshwater mussels
Authors: Klos P. Zion , Rosenberry Donald O. , Nelson Glenn R. 
Published: November 2014

AbstractBoth endangered and non‐endangered unionid mussels are heterogeneously distributed within the Allegheny River, Pennsylvania. Mussel populations vary from high to low density downstream of Kinzua Dam, and the direction, amount, and range of hyporheic exchange (seepage) at the sediment–water interface were suspected to influence their distribution and abundance. Nineteen hydrogeomorphic variables, including the quantification of seepage metrics, substrate size, river stage, river discharge, and shear stress, were measured at five reaches on the Allegheny River within 80 km downstream of Kinzua Dam. Analysis revealed significant (α = 0·05) non‐linear correlations between mussel population density and directional mean seepage (positive relationship), river width (positive relationship), and median substrate size (negative relationship). Specifically, seepage findings showed that increases in upward seepage and decreases in the overall range of seepage related to increases in mussel population density. River width, directional mean seepage, and median substrate size were also found to co‐vary with marginal significance (α = 0·1), making their individual influences on mussel population density uncertain. Absolute mean seepage, water depth, hydraulic head, temperature differences between the surface water and substrate, and other substrate metrics besides median grain size were not found to significantly correlate to mussel population density. Considering the physical processes often linking seepage to other explanatory variables, future research in seepage–mussel relationships should work to isolate the mechanistic influence of hyporheic exchange independently from its common covariation with substrate size and geomorphology. Copyright © 2014 John Wiley & Sons, Ltd.
Arachidonic acid enhances reproduction in Daphnia magna and mitigates changes in sex ratios induced by pyriproxyfen
Authors: Ginjupalli Gautam K. , Gerard Patrick D. , Baldwin William S. 
Published: November 2014

Abstract

Arachidonic acid is 1 of only 2 unsaturated fatty acids retained in the ovaries of crustaceans and an inhibitor of HR97g, a nuclear receptor expressed in adult ovaries. The authors hypothesized that, as a key fatty acid, arachidonic acid may be associated with reproduction and potentially environmental sex determination in Daphnia. Reproduction assays with arachidonic acid indicate that it alters female:male sex ratios by increasing female production. This reproductive effect only occurred during a restricted Pseudokirchneriella subcapitata diet. Next, the authors tested whether enriching a poorer algal diet (Chlorella vulgaris) with arachidonic acid enhances overall reproduction and sex ratios. Arachidonic acid enrichment of a C. vulgaris diet also enhances fecundity at 1.0 µM and 4.0 µM by 30% to 40% in the presence and absence of pyriproxyfen. This indicates that arachidonic acid is crucial in reproduction regardless of environmental sex determination. Furthermore, the data indicate that P. subcapitata may provide a threshold concentration of arachidonic acid needed for reproduction. Diet-switch experiments from P. subcapitata to C. vulgaris mitigate some, but not all, of arachidonic acid's effects when compared with a C. vulgaris–only diet, suggesting that some arachidonic acid provided by P. subcapitata is retained. In summary, arachidonic acid supplementation increases reproduction and represses pyriproxyfen-induced environmental sex determination in D. magna in restricted diets. A diet rich in arachidonic acid may provide protection from some reproductive toxicants such as the juvenile hormone agonist pyriproxyfen. Environ Toxicol Chem 2015;34:527–535. © 2014 SETAC
Automated method for determination of dissolved organic carbon–water distribution constants of structurally diverse pollutants using pre-equilibrium solid-phase microextraction
Authors: Ripszam Matyas , Haglund Peter 
Published: November 2014

Abstract

Dissolved organic carbon (DOC) plays a key role in determining the environmental fate of semivolatile organic environmental contaminants. The goal of the present study was to develop a method using commercially available hardware to rapidly characterize the sorption properties of DOC in water samples. The resulting method uses negligible-depletion direct immersion solid-phase microextraction (SPME) and gas chromatography–mass spectrometry. Its performance was evaluated using Nordic reference fulvic acid and 40 priority environmental contaminants that cover a wide range of physicochemical properties. Two SPME fibers had to be used to cope with the span of properties, 1 coated with polydimethylsiloxane and 1 coated with polystyrene divinylbenzene polydimethylsiloxane, for nonpolar and semipolar contaminants, respectively. The measured DOC–water distribution constants showed reasonably good reproducibility (standard deviation ≤ 0.32) and good correlation (R2 = 0.80) with log octanol–water partition coefficients for nonpolar persistent organic pollutants. The sample pretreatment is limited to filtration, and the method is easy to adjust to different DOC concentrations. These experiments also utilized the latest SPME automation that largely decreases total cycle time (to 20 min or shorter) and increases sample throughput, which is advantageous in cases when many samples of DOC must be characterized or when the determinations must be performed quickly, for example, to avoid precipitation, aggregation, and other changes of DOC structure and properties. The data generated by this method are valuable as a basis for transport and fate modeling studies. Environ Toxicol Chem 2014;9999:1–9. © 2014 SETAC
Hierarchical Bayesian Model for Rare Variant Association Analysis Integrating Genotype Uncertainty in Human Sequence Data
Authors: He Liang , Pitkäniemi Janne , Sarin Antti‐Pekka , Salomaa Veikko , Sillanpää Mikko J. , Ripatti Samuli 
Published: November 2014

ABSTRACTNext‐generation sequencing (NGS) has led to the study of rare genetic variants, which possibly explain the missing heritability for complex diseases. Most existing methods for rare variant (RV) association detection do not account for the common presence of sequencing errors in NGS data. The errors can largely affect the power and perturb the accuracy of association tests due to rare observations of minor alleles. We developed a hierarchical Bayesian approach to estimate the association between RVs and complex diseases. Our integrated framework combines the misclassification probability with shrinkage‐based Bayesian variable selection. It allows for flexibility in handling neutral and protective RVs with measurement error, and is robust enough for detecting causal RVs with a wide spectrum of minor allele frequency (MAF). Imputation uncertainty and MAF are incorporated into the integrated framework to achieve the optimal statistical power. We demonstrate that sequencing error does significantly affect the findings, and our proposed model can take advantage of it to improve statistical power in both simulated and real data. We further show that our model outperforms existing methods, such as sequence kernel association test (SKAT). Finally, we illustrate the behavior of the proposed method using a Finnish low‐density lipoprotein cholesterol study, and show that it identifies an RV known as FH North Karelia inLDLRgene with three carriers in 1,155 individuals, which is missed by both SKAT and Granvil.
Stabilization of iron arsenate solids by encapsulation with aluminum hydroxyl gels
Authors: Leetmaa Karl , Guo Fuqiang , Becze Levente , Gomez Mario A , Demopoulos George P 
Published: November 2014

AbstractBACKGROUNDFerric arsenate solids in the form of scorodite (FeAsO4·2H2O) particles are suitable carriers for immobilization of arsenic‐rich wastes. The stability of scorodite is, however, highly pH dependent (typically at 4≤ pH ≤7) and satisfactory only under oxic disposal conditions. In this work a new stabilization technology based on the concept of encapsulation with aluminum hydroxyl gels is investigated to enhance the stability of arsenical solids over a wider range of disposal conditions.RESULTSThe encapsulation system investigated involves blending and short‐term ageing of synthetic scorodite particles with amorphous aluminum hydroxyl gels derived from partial hydrolysis of aluminum chloride or aluminum sulfate salts. Of the two gel types, the Al(SO4)1.5‐derived gel proved to be the most effective, even at the very low Al(III)/As(V) molar ratio of 0.1, apparently due to in situ development of protective aluminum hydroxide matrix and not as a simple adsorption sink for soluble arsenate species.CONCLUSIONArsenic release from the scorodite–aluminum hydroxyl gel composites was found to be drastically reduced with respect to gel‐free scorodite, making this system a very interesting candidate for further development as an effective hazardous material encapsulating material. © 2014 Society of Chemical Industry
Cyclostationary noise modeling of radio frequency devices
Authors: Bonani F. , Guerrieri S. Donati , Ghione G. 
Published: November 2014

SummaryWe present a review of the current status of research in the modeling and simulation of cyclostationary (nonlinear) noise properties of semiconductor active devices operated in forced large‐signal conditions, a typical operating regime for high‐frequency applications. We discuss both the case of physics‐based device simulations, where numerical burden is the most important issue, and the derivation of compact cyclostationary noise models. In the latter case, both phenomenological amplitude modulation approaches and the derivation of consistent analytical device descriptions are discussed. We show examples of both physics‐based simulations of the noise properties of a realistic high‐electron mobility transistor resistive mixer and show for the first time the application of a novel, fully analytical cyclostationary noise bipolar transistor model. Copyright © 2014 John Wiley & Sons, Ltd.