bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recovery of left ventricular function after percutaneous revascularization of a left main chronic total occlusion
Authors: Khanna Pravien , Stilp Erik , Pfau Steven 
Published: May 2012

AbstractSurgical revascularization of left main and/or three‐vessel coronary artery disease (CAD) is associated with improved survival in patients with left ventricular dysfunction when compared to medical therapy and can result in improved left ventricular ejection fraction (LVEF) [1]. Multivessel percutaneous coronary intervention (PCI) is equivalent to surgery regarding short and intermediate term mortality, and left main PCI has emerged as a safe and effective alternate to surgical revascularization [2]. However, outcomes of unprotected left main PCI in patients with severely depressed LVEF have not been examined. We report a patient with left main chronic total occlusion, multivessel CAD, and dilated cardiomyopathy, in whom complete revascularization via PCI resulted in decreased left ventricular size and improved LVEF. © 2012 Wiley Periodicals, Inc.
Novel use of a disposable digital pressure transducer to increase the safety of pericardiocentesis
Authors: Visweswaran Gautam K. , Lightfoot James , Gilchrist Ian C. 
Published: May 2012

AbstractCardiac tamponade represents a medical emergency necessitating emergent pericardiocentesis. Use of two‐dimensional echocardiography (ECHO) has improved the safety of pericardiocentesis, but procedural challenges may occur when performed in an emergent manner outside of the catheterization laboratory without availability of fluoroscopy and readily available pressure transducers. The most problematic situation is the initial finding of bloody fluid on aspiration where intrapericardial versus intravascular location of the needle must be determined. We report two cases of cardiac tamponade managed with the use of a novel, disposable lightweight digital pressure transducer to directly measure intrapericardial pressures during an ECHO guided pericardiocentesis. In both cases the fluid initially encountered was grossly bloody and rapid definition of whether this was pericardial fluid versus an inappropriately located needle in the vascular space was critical. This type of novel, disposable self contained manometer has the potential to further minimize complications associated with pericardiocentesis. It offers a cost effective alternative and answers questions about the shifting point of service for pericardiocentesis from the invasive cath lab to less costly locations (Drummond, et al., J Am Soc Echocardiogr 1998;11:433–435). © 2012 Wiley Periodicals, Inc.
The balloon dilation of the pulmonary valve during early repair of tetralogy of Fallot
Authors: Vida Vladimiro L. , Padalino Massimo A. , Maschietto Nicola , Biffanti Roberta , Anderson Robert H , Milanesi Ornella , Stellin Giovanni 
Published: May 2012

AbstractBackground and objectiveProgressive pulmonary valve (PV) regurgitation leads to right ventricular failure after repair of tetralogy of Fallot (TOF). We sought to evaluate our results with the preservation of the PV in selected patients with TOF.MethodsAll patients with TOF who were scheduled for PV's preservation between June 2007 and May 2010 were enrolled. Surgical correction involved the combination of early transatrial repair and intraoperative balloon dilation of the PV annulus.ResultsOf 18 patients, 16 (89%) underwent a successful preservation of the PV. Median age at surgery was 3.1 months (range 2.4–4.7 months). Median preoperative PV Z‐score was −2.5 (range −1.4 to −3.12) and the median peak right ventricle outflow tract (RVOT) gradient was 80 mm Hg (range 49–90 mm Hg). No procedure‐related complications were reported. The size of the PV annulus after the balloon dilation was appropriate for body surface area in all patients. Median follow‐up time was 1.4 years (range 0.5–3.3 years). Reoperation was needed in one patient 3 months after repair because of residual subvalvar RVOT obstruction. The remaining 15 patients are alive and well. The median PV Z‐score is 0 (range −0.2 to 1). Median peak RVOT gradient is 20 mm Hg (range 12–32 mm Hg). The PV is competent in seven patients; mild PV regurgitation is present in seven patients and moderate in one.ConclusionsThe integrity of the PV annulus and PV function can be preserved in selected patients during early repair of TOF when using concomitant balloon dilation. The PV preservation will hopefully prevent long‐standing RV dysfunction. © 2012 Wiley Periodicals, Inc.
N‐Heterocyclic Tridentate Aromatic Ligands Bound to [Ln(hexafluoroacetylacetonate)3] Units: Thermodynamic, Structural, and Luminescent Properties
Authors: Zaïm Amir , Nozary Homayoun , Guénée Laure , Besnard Céline , Lemonnier Jean‐François , Petoud Stéphane , Piguet Claude 
Published: May 2012

AbstractHerein, we discuss how, why, and when cascade complexation reactions produce stable, mononuclear, luminescent ternary complexes, by considering the binding of hexafluoroacetylacetonate anions (hfac−) and neutral, semi‐rigid, tridentate 2,6‐bis(benzimidazol‐2‐yl)pyridine ligands (Lk) to trivalent lanthanide atoms (LnIII). The solid‐state structures of [Ln(Lk)(hfac)3] (Ln=La, Eu, Lu) showed that [Ln(hfac)3] behaved as a neutral six‐coordinate lanthanide carrier with remarkable properties: 1) the strong cohesion between the trivalent cation and the didentate hfac anions prevented salt dissociation; 2) the electron‐withdrawing trifluoromethyl substituents limited charge‐neutralization and favored cascade complexation with Lk; 3) nine‐coordination was preserved for [Ln(Lk)(hfac)3] for the complete lanthanide series, whilst a counterintuitive trend showed that the complexes formed with the smaller lanthanide elements were destabilized. Thermodynamic and NMR spectroscopic studies in solution confirmed that these characteristics were retained for solvated molecules, but the operation of concerted anion/ligand transfers with the larger cations induced subtle structural variations. Combined with the strong red photoluminescence of [Eu(Lk)(hfac)3], the ternary system LnIII/hfac−/Lk is a promising candidate for the planned metal‐loading of preformed multi‐tridentate polymers.
Catalytic Enantioselective Halolactonization of Enynes and Alkenes
Authors: Zhang Wei , Liu Na , Schienebeck Casi M. , Decloux Kyle , Zheng Suqing , Werness Jenny B. , Tang Weiping 
Published: May 2012

AbstractNew organocatalysts have been developed for the enantioselective halolactonization of (Z)‐1,3‐enynes and 1,1‐disubstituted alkenes. In the case of 1,3‐enynes, the carboxylate nucleophile and halogen electrophile were added to the conjugated π‐system from the same face. Up to 99 % ee was achieved for the 1,4‐syn‐bromolactonization of conjugated (Z)‐1,3‐enynes. Based on the results from the enyne halolactonization, a second generation of catalysts was designed for simple olefins. Up to 91 % ee was observed for chlorolactonization of 1,1‐disubstituted alkenes. The catalysts developed for the enantioselective halolactonization of both enynes and alkenes are composed of a cinchona alkaloid skeleton tethered to a urea group.
Anion‐Induced Shuttling of a Naphthalimide Triazolium Rotaxane
Authors: Spence Graeme T. , Pitak Mateusz B. , Beer Paul D. 
Published: May 2012

AbstractThe anion‐templated synthesis of a rotaxane structure, incorporating the new naphthalimide triazolium motif, is described and the interlocked host shown to exhibit selective, uni‐directional, anion‐induced shuttling. Initial pseudorotaxane investigations demonstrate the ability of a naphthalimide triazolium threading component to form interpenetrated assemblies with counter‐anion‐dependent co‐conformations. 1H NMR studies reveal that the shuttling behaviour of the analogous rotaxane host system is controlled by selective anion binding and by the nature of the solvent conditions. Complete macrocycle translocation only occurs upon the recognition of the smaller halide anions (chloride and bromide). The rotaxane solid‐state crystal structure in the presence of chloride is in agreement with the solution‐phase co‐conformation. The sensitivity of the axle naphthalimide absorbance band to the position of the macrocycle component within the interlocked structure enabled the molecular motion to be observed by UV/Vis spectroscopy, and the chloride‐induced shuttling of the rotaxane was reversed upon silver hexafluorophosphate addition.
Considerations of Noise and Measurement Reproducibility of Circular Dichroism Measurements Using Na[CoIII(EDDS)]
Authors: Chmel Nikola Paul , Scott Peter , Rodger Alison 
Published: May 2012

ABSTRACTAlthough circular dichroism (CD) spectroscopy has become ubiquitous in biological, chemical, and pharmacological laboratories, several issues with instrument calibration and standardization, measurements quality, and reproducibility still remain. In the context of validating and developing a wide‐wavelength‐range stable standard for CD that is available in both enantiomeric forms, (R,R)‐ and (S,S)‐Na[CoIII(EDDS)] (where EDDS is ethylenediaminedisuccinato), we have become aware of sources of error in CD spectroscopy in addition to instrument calibration and user issues. This article summarizes those errors and suggests procedures for minimizing them by averaging over sufficient independent data accumulations with appropriate parameters. Chirality 24:699–705, 2012. © 2012 Wiley Periodicals, Inc.
A simple calorimeter to measure specific heat of activated carbon prepared for pressure swing adsorption refrigeration system
Authors: Anupam Kumar , Halder G. N. , Roy Zunipa , Sarkar S. C. , Yadav Akshat 
Published: May 2012

AbstractA new calorimeter to measure specific heat of indigenously prepared granular activated carbon (AC) for application in a refrigeration system based on gas adsorption–desorption mechanism is presented. This calorimeter allows specific heat measurements in high (305.5–317.8 K) as well as low (254.6–264 K) temperature ranges. The specific heat of prepared AC on measurement using developed calorimeter has been found to be 1.062 J g−1 K−1. Preparation, instrumental analyses and influence of various physical properties of AC on its specific heat have also been discussed. Characterisation results of AC demonstrate that it can be efficiently used in such cold producing system down to refrigeration and cryogenic temperature. © 2012 Canadian Society for Chemical Engineering
Synthesis of Hydrazone‐Modified Nucleotides and Their Polymerase Incorporation onto DNA for Redox Labeling
Authors: Raindlová Veronika , Pohl Radek , Klepetářová Blanka , Havran Luděk , Šimková Eva , Horáková Petra , Pivoňková Hana , Fojta Miroslav , Hocek Michal 
Published: May 2012

Abstract5‐(5‐Formylthiophen‐2‐yl)cytosine, 7‐(5‐formylthiophen‐2‐yl)‐7‐deazaadenosine 2′‐deoxyribonucleosides, and their 5′‐O‐triphosphates (dNTPs) were converted into the 2,4‐dinitrophenylhydrazone or nitrobenzofurazanyl. The hydrazone‐modified dNTPs were enzymatically incorporated into DNA by polymerase catalyzed primer extension (PEX). This direct incorporation of hydrazone‐linked dNTPs was compared to previously reported incorporation of aldehyde‐modified dNTPs followed by postsynthetic hydrazone formation on DNA to show that the direct incorporation can be used for incorporation of more hydrazone units, however, cleaner PEX products are formed by incorporation of aldehydes and subsequent reaction with hydrazines. Extensive study of electrochemical behavior of the nitroarylhydrazone‐linked nucleosides and DNA was performed confirming the potential utility of the hydrazone, nitroaryl, and benzofurazane groups for redox labeling of DNA.
Phase Change of Nickel Phosphide Catalysts in the Conversion of Cellulose into Sorbitol
Authors: Yang Pengfei , Kobayashi Hirokazu , Hara Kenji , Fukuoka Atsushi 
Published: May 2012

AbstractNickel phosphide catalysts supported on activated carbon were tested for the conversion of cellulose in water. High sorbitol yields of over 60 % were obtained with high cellulose conversions at 503 K and 5 MPa of H2. It is interesting that an amorphous nickel phosphide phase is generated from a crystalline phase during the increase in temperature and that the amorphous phase is responsible for the high yield of sorbitol. The optimization of the reaction parameters indicates that the increase of the amorphous part in the cellulose is the key to obtaining high yields of sorbitol. A phase change of the nickel phosphide is observed, which can be correlated to the change in catalytic activity.
Solvent Effects on the Hydrogenolysis of Diphenyl Ether with Raney Nickel and their Implications for the Conversion of Lignin
Authors: Wang Xingyu , Rinaldi Roberto 
Published: May 2012

AbstractThe conversion of lignin, the most recalcitrant of the biopolymers, is necessary for a carbon‐efficient utilization of lignocellulosic materials. In this context, hydrogenolysis of lignin is a process receiving increasing attention. In this report, the solvent effects on the hydrogenolysis of diphenyl ether and lignin with Raney Ni are addressed. The Lewis basicity of the solvent very much affects the catalytic activity, so Raney Ni in nonbasic solvents is an extremely active catalyst for hydrogenolysis and hydrogenation. In basic solvents, however, Raney Ni is a less active, but much more selective catalyst for hydrogenolysis while preserving the aromatic products. With regard to the reactions with lignin, assessing the complexity of the product mixtures by two‐dimensional GC×GC–MS revealed solvent effects on the product distribution. Reaction in methylcyclohexane resulted in cyclic alcohols and cyclic alkanes, whereas reaction in 2‐propanol led to cyclic alcohols, cyclic ketones, and unsaturated products. The hydrogenolysis of lignin in methanol, however, produced mostly phenols. Overall, these results demonstrate that the solvent plays a key role in directing the selectivity and, thus, it must be taken into consideration in the design of catalytic systems for conversion of lignin by hydrogenolysis of CO ether bonds.
Sleep and sleepiness among first‐time postpartum parents: A field‐ and laboratory‐based multimethod assessment
Authors: Insana Salvatore P. , Montgomery‐Downs Hawley E. 
Published: May 2012

AbstractThe study aim was to compare sleep, sleepiness, fatigue, and neurobehavioral performance among first‐time mothers and fathers during their early postpartum period. Participants were 21 first‐time postpartum mother–father dyads (N = 42) and seven childless control dyads (N = 14). Within their natural environment, participants completed 1 week of wrist actigraphy monitoring, along with multi‐day self‐administered sleepiness, fatigue, and neurobehavioral performance measures. The assessment week was followed by an objective laboratory‐based test of sleepiness. Mothers obtained more sleep compared to fathers, but mothers' sleep was more disturbed by awakenings. Fathers had greater objectively measured sleepiness than mothers. Mothers and fathers did not differ on subjectively measured sleep quality, sleepiness, or fatigue; however, mothers had worse neurobehavioral performance than fathers. Compared to control dyads, postpartum parents experienced greater sleep disturbance, sleepiness, and sleepiness‐associated impairments. Study results can inform social policy, postpartum sleep intervention development, and research on postpartum family systems and mechanisms that propagate sleepiness. © 2012 Wiley Periodicals, Inc. Dev Psychobiol 55: 361–372, 2013
The influence of natural flow regimes on macroinvertebrate assemblages in a semiarid Mediterranean basin
Authors: Belmar O. , Velasco J. , Gutiérrez‐Cánovas C. , Mellado‐Díaz A. , Millán A. , Wood P. J. 
Published: May 2012

ABSTRACTThe investigation of flow–ecology relationships constitutes the basis for the development of environmental flow criteria. The need to understand hydrology–ecology linkages in natural systems has increased owing to the prospect of climate change and flow regime management, especially in water‐scarce areas such as Mediterranean basins. Our research quantified the macroinvertebrate community response at family, genus and species level to natural flow regime dynamics in freshwater streams of a Mediterranean semiarid basin (Segura River, SE Spain) and identified the flow components that influence the composition and richness of biotic assemblages. Flow stability and minimum flows were the principal hydrological drivers of macroinvertebrate assemblages, whereas the magnitude of average and maximum flows had a limited effect. Perennial stable streams were characterized by flow sensitive lotic taxa (Ephemeroptera, Plecoptera and Trichoptera) and intermittent streams by predominately lentic taxa (Odonata, Coleoptera, Heteroptera and Diptera). Relatively minor biological changes were recorded for intermediate flow regime classes along a gradient of flow stability. Seasonal variation and minimum flows are key hydrological components that need to be considered for river management and environmental flows in the Segura River basin and other Mediterranean basins. The anthropogenic modification of these parameters, due to both human activities and climate change, would probably lead to significant changes in the structure and composition of communities in perennial stable streams. This would be characterized by a reduction of flow sensitive Ephemeroptera, Plecoptera and Trichoptera taxa and an increase in more resilient Odonata, Coleoptera, Heteroptera and Diptera taxa. Copyright © 2012 John Wiley & Sons, Ltd.
Synthesis of CLA‐enriched TAG by Candida antarctica lipase under vacuum
Authors: Hong Seung In , Kim Yangha , Yoon Sung Won , Cho Seung Yong , Kim In‐Hwan 
Published: May 2012

AbstractConjugated linoleic acid (CLA)‐enriched triacylglycerol (TAG) of 90 wt% was successfully synthesized in 10 h by direct esterification of glycerol and CLA using an immobilized lipase from Candida antarctica under vacuum. The best operating conditions for the synthesis of TAG were investigated according to the three parameters of temperature, enzyme loading, and vacuum. The synthesis of TAG increased with increasing temperature but it did not significantly change above 60°C (p>0.05). The increase of enzyme loading lead to an enhanced conversion of TAG, but enzyme loading of more than 10% (based on the total weight of the substrates) was not effective. Moreover, when vacuum increased, the conversion of TAG increased, but the conversion rate decreased when the vacuum level was too high. The best combination of temperature, enzyme loading, and vacuum level were 60°C, 10% of the total weight of the substrates, and 0.4 kPa, respectively. During the initial 6 h of reaction, Candida antarctica lipase had more selectivity for 10t,12c‐CLA than 9c,11t‐CLA onto the glycerol backbone, and a preference for the incorporation at the sn‐1,3 positions of glycerol rather than at the sn‐2 position.
Synthesis and properties of novel alkyl sulfate gemini surfactants
Authors: Tai Shuxin , Gao Zhinong , Liu Xueguo , Zhang Qi 
Published: May 2012

AbstractFour anionic gemini surfactants of the sulfate type C12CnC12, where n is the spacer chain length (n = 3, 4, 6, and 10) were synthesized. The structures of these surfactants were confirmed by FT‐IR, 1H NMR, ESI mass spectra (ESI‐MS), and elemental analysis. The surface‐active properties of these compounds were investigated by means of surface tension, electrical conductivity, and fluorescence measurements. Premicellar aggregations were found for the four gemini surfactants, as revealed by the conductivity measurement. The formation of premicellar aggregates may account for the discrepancy between the critical micelle concentration (cmc) obtained by the surface tension and conductivity measurement. The cmc values of these gemini surfactants were much lower than that of sodium dodecylsulfate (SDS) and decreased monotonously with the increase of spacer chain length from 3 to 10. The effect of spacer chain length on the performance properties like foaming, emulsion stability, and lime soap dispersing ability were also studied and discussed.Practical applications: Alkyl sulfate surfactants are one of the most widely used surfactants. The new alkyl sulfate gemini surfactants synthesized in our study are more surface‐active than sodium dodecylsulfate. These gemini surfactants possess low critical micelle concentrations, high emulsion stability, and excellent lime soap dispersing ability. They have potential applications in the fields of cosmetics, detergents, etc.
Total Syntheses of Dichotomines A–D and the Stereochemical Revision of Dichotomines B–D
Authors: Zhang Qiang , Dong Jing , Shi Xiao‐Xin , Lu Xia 
Published: May 2012

AbstractNew asymmetric total syntheses of (–)‐dichotomines A–D (1–4) starting from L‐tryptophan methyl ester and 2,3‐O‐isopropylidene‐D‐glyceraldehyde are described. The absolute configuration of the stereogenic center of (–)‐dichotomine A (1) was reconfirmed as (S), on the basis of the X‐ray crystallographic analysis of the conjugate (i.e., 17) of its methyl ester (i.e., 16) with (S)‐N‐tosylproline, whereas the absolute configurations of the stereogenic centers of (–)‐dichotomines B–D (2–4) were revised as (R).
One‐Pot Oxidation–Hydrocyanation Sequence Coupled to Lipase‐Catalyzed Diastereoresolution in the Chemoenzymatic Synthesis of Sugar Cyanohydrin Esters (Eur. J. Org. Chem. 14/2012)
Authors: Hietanen Ari , Kanerva Liisa T. 
Published: May 2012

AbstractThe cover picture shows the key intermediates in the chemoenzymatic sequence in one‐pot from peracetylated methyl α‐D‐glycosides into sugar cyanohydrin acetates. The method allows the stereoselective substitution of hydrogen with a nitrile group through labile intermediates that are not separated. Lipase from Burkholderia cepacia, a key enzyme responsible for selectivity in the sequence, is shown in the middle (adopted from pdb entry 1OIL). Details are discussed in the article by A. Hietanen and L. T. Kanerva on p. 2729 ff. magnified image
Multiple‐slider surfaces bearing for seismic retrofitting of frame structures with soft first stories
Authors: Fakhouri Muhannad Y. , Igarashi Akira 
Published: May 2012

SUMMARYA new isolation interface is proposed in this study to retrofit existing buildings with inadequate soft stories as well as new structures to be constructed with soft first story intended for architectural or functional purposes. The seismic interface is an assembly of bearings set in parallel on the top of the first story columns: the multiple‐slider bearings and rubber bearings. The multiple‐slider bearing is a simple sliding device consisting of one horizontal and two inclined plane sliding surfaces based on polytetrafluoroethylene and highly polished stainless steel interface at both ends set in series. A numerical example of a five‐story reinforced concrete shear frame with soft first story is considered and analyzed to demonstrate the efficiency of the proposed isolation system in reducing the ductility demand and damage in the structure while maintaining the superstructure above the bearings to behave nearly in the elastic range with controlled bearing displacement. Comparative study with the conventional system as well as various isolation systems such as rubber bearing interface and resilient sliding isolation is carried out. Moreover, an optimum design procedure for the multiple‐slider bearing is proposed through the trade‐off between the maximum bearing displacement and the first story ductility demand ratio. The results of extensive numerical analysis verify the effectiveness of the multiple‐slider bearing in minimizing the damage from earthquake and protecting the soft first story from excessively large ductility demand. Copyright © 2012 John Wiley & Sons, Ltd.