bluuebunny/crossref_metadata_2025_split huggingface dataset:
Microstructure‐Lattice Thermal Conductivity Correlation in Nanostructured PbTe0.7S0.3 Thermoelectric Materials
Authors: He Jiaqing , Girard Steven N. , Kanatzidis Mercouri G. , Dravid Vinayak P. 
Published: February 2010

AbstractThe reduction of thermal conductivity, and a comprehensive understanding of the microstructural constituents that cause this reduction, represent some of the important challenges for the further development of thermoelectric materials with improved figure of merit. Model PbTe‐based thermoelectric materials that exhibit very low lattice thermal conductivity have been chosen for this microstructure–thermal conductivity correlation study. The nominal PbTe0.7S0.3 composition spinodally decomposes into two phases: PbTe and PbS. Orderly misfit dislocations, incomplete relaxed strain, and structure‐modulated contrast rather than composition‐modulated contrast are observed at the boundaries between the two phases. Furthermore, the samples also contain regularly shaped nanometer‐scale precipitates. The theoretical calculations of the lattice thermal conductivity of the PbTe0.7S0.3 material, based on transmission electron microscopy observations, closely aligns with experimental measurements of the thermal conductivity of a very low value, ∼0.8 W m−1 K−1 at room temperature, approximately 35% and 30% of the value of the lattice thermal conductivity of either PbTe and PbS, respectively. It is shown that phase boundaries, interfacial dislocations, and nanometer‐scale precipitates play an important role in enhancing phonon scattering and, therefore, in reducing the lattice thermal conductivity.
Functional IrIII Complexes and Their Applications
Authors: Chen Zhu‐qi , Bian Zu‐qiang , Huang Chun‐hui 
Published: February 2010

AbstractIridium complexes are drawing great interest because they exhibit high phosphorescence quantum efficiency. Extensive efforts have been devoted to the molecular design of ligands to achieve phosphorescent emission over a wide range of wavelengths that is compatible with many applications. In this research news article, we focus on materials design to improve the performance of phosphorescent IrIII complexes for organic light‐emitting diodes (OLEDs), luminescence sensitizers, and biological imaging.
Magnetic‐Field‐ and Pressure‐Induced Quantum Phases in Complex Materials
Authors: Kim Minjung , Barath Harini , Chen Xiaoqian , Joe Young‐Il , Fradkin Eduardo , Abbamonte Peter , Cooper S. Lance 
Published: February 2010

AbstractThis Progress Report presents temperature‐, magnetic‐field‐, and pressure‐dependent Raman measurements of strongly correlated materials such as the charge‐ordering manganese perovskites, the multiferroic material TbMnO3, and the charge‐density wave (CDW) materials 1T‐TiSe2 and CuxTiSe2. These studies illustrate the rich array of phases and properties that can be accessed with field and pressure tuning in these materials, and demonstrate the efficacy of using magnetic‐field‐ and pressure‐dependent scattering methods to elucidate the microscopic changes associated with highly tunable behavior in complex materials.
Importance of the Conditioning of the Chitosan Support in a Catalyst‐Containing Ionic Liquid Phase Immobilised on Chitosan: The Palladium‐Catalysed Allylation Reaction Case
Authors: Moucel Renaud , Perrigaud Katy , Goupil Jean‐Michel , Madec Pierre‐Jean , Marinel Sylvain , Guibal Eric , Gaumont Annie‐Claude , Dez Isabelle 
Published: February 2010

AbstractCatalysts containing ionic liquid phase immobilised on chitosan are successfully applied to the palladium‐catalysed allylation reaction. A strong influence of the conditioning of chitosan not only on the activity and enantioselectivity but also on the recyclability and reusability of the catalyst is demonstrated.
Stereoselective Chemoenzymatic Preparation of β‐Amino Esters: Molecular Modelling Considerations in Lipase‐Mediated Processes and Application to the Synthesis of (S)‐Dapoxetine
Authors: Rodríguez‐Mata María , García‐Urdiales Eduardo , Gotor‐Fernández Vicente , Gotor Vicente 
Published: February 2010

AbstractA wide range of optically active 3‐amino‐3‐arylpropanoic acid derivatives have been prepared by means of a stereoselective chemoenzymatic route. The key step is the kinetic resolution of the corresponding β‐amino esters. Although the enzymatic acylations of the amino group with ethyl methoxyacetate showed synthetically useful enantioselectivities, the hydrolyses of the ester group catalyzed by lipase from Pseudomonas cepacia have been identified as the optimal processes concerning both activity and enantioselectivity. The enantiopreference of this lipase in these reactions has been explained, at the molecular level, by using a fragment‐based approach in which the most favoured binding site for a phenyl ring and the most stable conformation of the 3‐aminopropanoate core nicely match the (S)‐configuration of the major products. The conversion and enantioselectivity values of the enzymatic reactions have been compared in order to understand the influence of the different substitution patterns present in the phenyl ring. This chemoenzymatic route has been successfully applied to the preparation of a valuable intermediate in the synthesis of (S)‐dapoxetine, which has been chemically synthesised in excellent optical purity.
Kinetic Analysis of L‐Carnosine Formation by β‐Aminopeptidases
Authors: Heck Tobias , Makam Venkata S. , Lutz Jochen , Blank Lars M. , Schmid Andreas , Seebach Dieter , Kohler Hans‐Peter E. , Geueke Birgit 
Published: February 2010

AbstractThe β,α‐dipeptide L‐carnosine occurs in high concentrations in long‐lived innervated mammalian tissues and is widely sold as a food additive. On a large scale L‐carnosine is produced by chemical synthesis procedures. We have established two aqueous enzymatic reaction systems for the preparation of L‐carnosine using the dissolved bacterial β‐aminopeptidases DmpA from Ochrobactrum anthropi and BapA from Sphingosinicella xenopeptidilytica as catalysts and investigated the kinetics of the enzyme‐catalyzed peptide couplings. DmpA catalyzed the formation of L‐carnosine from C‐terminally activated β‐alanine derivatives (acyl donor) and L‐histidine (acyl acceptor) in an aqueous reaction mixture at pH 10 with high catalytic rates (Vmax=19.2 μmol min−1 per mg of protein, kcat=12.9 s−1), whereas Vmax in the BapA‐catalyzed coupling reaction remained below 1.4 μmol min−1 per mg of protein (kcat=0.87 s−1). Although the equilibrium of this reaction lies on the side of the hydrolysis products, the reaction is under kinetic control and L‐carnosine temporarily accumulated to concentrations that correspond to yields of more than 50% with respect to the employed acyl donor. However, competing nucleophiles caused unwanted hydrolysis and coupling reactions that led to decreased product yield and to formation of various peptidic by‐products. The substitution of L‐histidine for L‐histidine methyl ester as acyl acceptor shifted the pKa of the amino functionality from 9.25 to 6.97, which caused a drastic reduction in the amount of coupling by‐products in an aqueous reaction system at pH 8.
Methoxycarbonylation of Aliphatic Diamines with Dimethyl Carbonate Promoted by in situ Generated Hydroxide Ion: A Mechanistic Consideration
Authors: Kim Dae Won , Huh Eun Soo , Park Sang Do , Nguyen Ly Vinh , Nguyen Mai Dao , Kim Hoon Sik , Cheong Minserk , Nguyen Dinh Quan 
Published: February 2010

AbstractThe methoxycarbonylation reactions of aliphatic diamines with dimethyl carbonate are accelerated greatly in the presence of water. Theoretical investigations on the mechanistic aspects of the methoxycarbonylation of 1,6‐hexanediamine strongly suggest that the hydroxide ion, generated in situ from the interaction of 1,6‐hexanediamine with water, is an active catalytic species and plays a pivotal role in the rate‐determining hydrogen abstraction step from the amino group.
Facile and Efficient Synthesis of Hydrophenanthren‐1(2H)‐ones and Naphtho[2,1‐c]furan‐3(1H)‐ones by a Palladium‐Catalyzed Aryne Annulation Strategy
Authors: Huang Xian , Sha Feng , Tong Jiawei 
Published: February 2010

AbstractNovel palladium‐catalyzed carboannulation reactions of arynes with functionalized vinyl iodides are reported. By applying allyl‐substituted iodocycloenones and iodofuranones, a series of hydrophenanthren‐1(2H)‐ones and naphtho[2,1‐c]furan‐3(1H)‐ones were efficiently constructed in one pot under mild conditions.
Highly Linear‐Selective Hydroformylation of 1‐Alkenes using Formaldehyde as a Syngas Substitute
Authors: Makado Gouki , Morimoto Tsumoru , Sugimoto Yasuko , Tsutsumi Ken , Kagawa Natsuko , Kakiuchi Kiyomi 
Published: February 2010

AbstractA highly linear‐selective hydroformylation of 1‐alkenes using formaldehyde without the direct use of syngas is described. One rhodium(I) complex catalyzes two processes in the overall hydroformylation of 1‐alkenes using formaldehyde as the syngas substitute to give hydroformylated aldehydes with excellent regioselectivities. A high regioselectivity (linear/branched=up to 98/2) and chemical yield (up to 95%) can be achieved by the simultaneous use of two types of phosphanes as ligands.
Highly Efficient Copper‐Catalyzed Synthesis of Internal Alkynes via Aerobic Oxidative Arylation of Terminal Alkynes
Authors: Rao Honghua , Fu Hua , Jiang Yuyang , Zhao Yufen 
Published: February 2010

AbstractWe have developed a novel and highly efficient, copper‐catalyzed synthesis of internal alkynes via oxidative couplings of aromatic boronic acids with terminal alkynes at room temperature. The protocol uses inexpensive copper(I) oxide [Cu2O] as the catalyst, oxygen in the air as the stoichiometric oxidant; no ligand and sealed reaction vessels are required, and remarkable functional group tolerability is observed with coupling occurring.
Diastereoselective Hydrogenation of Substituted Quinolines to Enantiomerically Pure Decahydroquinolines
Authors: Heitbaum Maja , Fröhlich Roland , Glorius Frank 
Published: February 2010

AbstractThe stereoselective hydrogenation of auxiliary‐substituted quinolines was used to build up saturated and partially saturated heterocycles. In a first step, the formation and diastereoselective hydrogenation of 2‐oxazolidinone‐substituted quinolines to 5,6,7,8‐tetrahydroquinolines is reported. In this unprecedented process, stereocenters on the carbocyclic quinoline ring were formed with a dr of up to 89:11. Platinum oxide as a catalyst and trifluoroacetic acid as a solvent were found to be optimal for high levels of chemo‐ and stereoselectivity in this step. In a second hydrogenation step, the completely saturated decahydroquinolines with 4 newly formed stereocenters were obtained with enantioselectivities of up to 99%. Rhodium on carbon as a catalyst and acetic acid as a solvent gave the best results for this hydrogenation and allowed a traceless cleavage of the chiral auxiliary. Thus, this new method allows an efficient stereoselective synthesis of valuable 5,6,7,8‐tetrahydro‐ and decahydroquinoline products.
Copper‐Catalyzed Asymmetric Allylic Alkylation of Racemic Cyclic Substrates: Application of Dynamic Kinetic Asymmetric Transformation (DYKAT)
Authors: Langlois Jean‐Baptiste , Alexakis Alexandre 
Published: February 2010

AbstractThe copper‐catalyzed asymmetric allylic alkylation (AAA) is of great interest in organic synthesis. This reaction was extensively studied using a broad range of substrates, ligands and organometallic reagents. However, the use of racemic substrates was still limited. Although some processes of kinetic resolution are reported in the literature, no examples of quantitative deracemization are described as is the case for the Pd‐catalyzed allylic alkylation. We present here a full account of our investigations through the development of the first example of such a process in copper‐catalyzed AAA. High enantioselectivities (up to 99% ee), scope of the reaction and mechanistic considerations are reported herein.
The Substrate Spectra of Pentaerythritol Tetranitrate Reductase, Morphinone Reductase, N‐Ethylmaleimide Reductase and Estrogen‐Binding Protein in the Asymmetric Bioreduction of Activated Alkenes
Authors: Mueller Nicole J. , Stueckler Clemens , Hauer Bernhard , Baudendistel Nina , Housden Hazel , Bruce Neil C. , Faber Kurt 
Published: February 2010

AbstractFour flavoproteins from the old yellow enzyme (OYE) family, pentaerythritol tetranitrate (PETNR) reductase, N‐ethylmaleimide reductase (NEMR), morphinone reductase (MorR) and estrogen‐binding protein (EBP1), exhibited a broad substrate tolerance by accepting conjugated enals, enones, imides, dicarboxylic acids and esters, as well as a nitroalkene and therefore can be employed for the asymmetric bioreduction of carbon‐carbon double (CC) bonds. In particular, morphinone reductase and estrogen‐binding protein often showed a complementary stereochemical preference in comparison to that of previously investigated OYEs.
Gold‐Catalyzed Intramolecular Alkyne Cycloisomerization Cascade: Direct Synthesis of Aryl‐Annulated[a]carbazoles from Aniline‐Substituted Diethynylarenes
Authors: Hirano Kimio , Inaba Yusuke , Watanabe Toshiaki , Oishi Shinya , Fujii Nobutaka , Ohno Hiroaki 
Published: February 2010

AbstractAniline‐substituted diethynylarenes, which are readily synthesized through Sonogashira coupling reactions from commercially available 1,2‐dihaloarenes, directly produce aryl‐ and heteroaryl‐annulated[a]carbazoles by the gold‐catalyzed intramolecular cascade hydroamination/cycloisomerization without producing theoretical by‐products. This new atom‐economical route is easily applicable to various aryl‐annulated[a]carbazoles containing an alkyl, aryl or ester substituent.
Frequency response analysis of slot coating
Authors: Tsuda Takeaki , de Santos Juan M. , Scriven L. E. 
Published: February 2010

AbstractFrequency responses to the slot die coating process is analyzed using empirical modal analysis to predict the effects of periodic process disturbances such as gap oscillation and variations in vacuum pressure, web velocity, and flow rate. A type of empirical modal analysis known as an experimental modal approach was used, and an oscillator basis model was assumed by using a linearized governing equation, and the coefficient of the basis model was determined by curve‐fitting. By completing the process, we were able to decompose each mode, during which process it was found that the modes are of two types: a squeeze mode related to viscous characteristics and sinuous modes that are identical to capillary waves. Observation of the meniscus shapes of each mode revealed, in the third mode near the lip edge, significant fluctuations that can induce other coating defects. © 2010 American Institute of Chemical Engineers AIChE J, 2010
Macaques in farms and folklore: exploring the human–nonhuman primate interface in Sulawesi, Indonesia
Authors: Riley Erin P. , Priston Nancy E. C. 
Published: February 2010

AbstractThe island of Sulawesi is an ecologically diverse and anthropogenically complex region in the Indonesian archipelago; it is home to multiple macaque species and a key locus of human–nonhuman primate interconnections. Here, we review the ethnoprimatology of Sulawesi by exploring two primary domains of the human–macaque interface: overlapping resource use and cultural perceptions of macaques. Crop raiding is the primary form of overlapping resource use. While the raiding of cacao plantations predominates in Central and South Sulawesi, subsistence crops (e.g., sweet potato and maize) are most vulnerable on Buton, Southeast Sulawesi. Despite this overlap levels of conflict are generally low, with farmers showing considerable tolerance. This tolerance can be explained by positive perceptions of the macaques despite their crop raiding behavior, and the finding that in some areas macaques figure prominently in local folklore, hence affording them protection. These findings provide some hope for the future management and conservation of these endemic macaques. Am. J. Primatol. 72:848–854, 2010. © 2010 Wiley‐Liss, Inc.
Fecal bacterial diversity of human‐habituated wild chimpanzees (Pan troglodytes schweinfurthii) at Mahale Mountains National Park, Western Tanzania
Authors: Szekely Brian A. , Singh Jatinder , Marsh Terence L. , Hagedorn Charles , Werre Stephen R. , Kaur Taranjit 
Published: February 2010

AbstractAlthough the intestinal flora of chimpanzees has not been studied, insight into this dynamic environment can be obtained through studies on their feces. We analyzed fecal samples from human‐habituated, wild chimpanzees at Mahale Mountains National Park, Tanzania, and compared microbial community profiles to determine if members of the same social group were similar. Between July and December 2007, we collected fresh fecal samples from 12 individuals: four juveniles, four adolescents, and four adults, including three parent–offspring pairs. Each sample was analyzed using Terminal‐Restriction Fragment Length Polymorphism of amplified 16S rRNA genes. Twelve different profiles were generated, having between 1 and 15 Terminal‐Restriction Fragments (T‐RFs). Overall, a total of 23 different T‐RFs were produced. Putative assignments of T‐RFs corresponded to the phyla Firmicutes (Clostridia, Bacilli, and Lactobacilli), Bacteroidetes, Tenericutes (Mollicutes Class), Actinobacteria, and Proteobacteria, as well as to uncultured or unidentified organisms. Firmicutes and Bacteroidetes phyla and Mollicutes Class were the most commonly assigned in 11, 8, and 8 of the samples, respectively, with this being the first report of Mollicutes in wild chimpanzees. Principal Components Analysis (PCA) revealed clustering of nine samples, and 80.5% of the diversity was accounted for by three samples. Morisita indices of community similarity ranged between 0.00 and 0.89, with dissimiliarity (<0.5) between most samples when compared two at a time. Our findings suggest that, although phylotypes are common among individuals, profiles among members of the same social group are host‐specific. We conclude that factors other than social group, such as kinship and age, may influence fecal bacterial profiles of wild chimpanzees, and recommend that additional studies be conducted. Am. J. Primatol. 72:566–574, 2010. © 2010 Wiley‐Liss, Inc.
The outbursts of classical and recurrent novae
Authors: Bode M.F. 
Published: February 2010

AbstractIn this review, I present our current state of knowledge regarding both Classical Nova and Recurrent Nova systems. Two particular objects (V1974 Cyg and RS Oph) are chosen to illustrate the range of phenomena that may be associated with their outbursts. The wider importance of nova research is emphasised and some of the most pressing unsolved problems are summarised (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray observations of classical novae: Theoretical implications
Authors: Hernanz M. , Sala G. 
Published: February 2010

AbstractDetection of X‐rays from classical novae, both in outburst and post‐outburst, provides unique and crucial information about the explosion mechanism. Soft X‐rays reveal the hot white dwarf photosphere, whenever hydrogen (H) nuclear burning is still on and expanding envelope is transparent enough, whereas harder X‐rays give information about the ejecta and/or the accretion flow in the reborn cataclysmic variable. The duration of the supersoft X‐ray emission phase is related to the turn‐off of the classical nova, i.e., of the H‐burning on top of the white dwarf core. A review of X‐ray observations is presented, with a special emphasis on the implications for the duration of post‐outburst steady H‐burning and its theoretical explanation. The particular case of recurrent novae (both the “standard” objects and the recently discovered ones) will also be reviewed, in terms of theoretical feasibility of short recurrence periods, as well as regarding implications for scenarios of type Ia supernovae (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Beginning of the super‐soft phase of the classical nova V2491 Cygni
Authors: Takei D. , Ness J.‐U. 
Published: February 2010

AbstractWe present the results of soft X‐ray studies of the classical nova V2491 Cygni using the Suzaku observatory. On day 29 after outburst, a soft X‐ray component with a peak at ∼0.5 keV has appeared, which is tantalising evidence for the beginning of the super‐soft X‐ray emission phase. We show that an absorbed blackbody model can describe the observed spectra, yielding a temperature of 57 eV, neutral hydrogen column density of 2 × 1021 cm–2, and a bolometric luminosity of ∼1036 erg s–1. However, at the same time, we also found a good fit with an absorbed thin‐thermal plasma model, yielding a temperature of 0.1 keV, neutral hydrogen column density of 4 × 1021 cm–2, and a volume emission measure of ∼1058 cm–3. Owing to low spectral resolution and low signal‐to‐noise ratio below 0.6 keV, the statistical parameter uncertainties are large, but the ambiguity of the two very different models demonstrates that the systematic errors are the main point of concern. The thin‐thermal plasma model implies that the soft emission originates from optically thin ejecta, while the blackbody model suggests that we are seeing optically thick emission from the white dwarf (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
X‐ray emission from optical novae in M 31
Authors: Pietsch W. 
Published: February 2010

AbstractThe first supersoft source (SSS) identification with an optical nova in M 31 was based on ROSAT observations. Twenty additional X‐ray counterparts (mostly identified as SSS by their hardness ratios) were detected using archival ROSAT, XMM‐Newton and Chandra observations obtained before July 2002. Based on these results optical novae seem to constitute the major class of SSS in M 31. An analysis of archival Chandra HRC‐I and ACIS‐I observations obtained from July 2004 to February 2005 demonstrated that M 31 nova SSS states lasted from months to about 10 years. Several novae showed short X‐ray outbursts starting within 50 d after the optical outburst and lasting only two to three months. The fraction of novae detected in soft X‐rays within a year after the optical outburst was more than 30%. Ongoing optical nova monitoring programs, optical spectral follow‐up and an up‐to‐date nova catalogue are essential for the X‐ray work. Re‐analysis of archival nova data to improve positions and find additional nova candidates are urgently needed for secure recurrent nova identifications. Dedicated XMM‐Newton/Chandra monitoring programs for X‐ray emission from optical novae covering the centre area of M 31 continue to provide interesting new results (e.g. coherent 1105 s pulsations in the SSS counterpart of nova M31N 2007‐12b). The SSS light curves of novae allow us – together with optical information – to estimate the mass of the white dwarf, of the ejecta and the burned mass in the outburst. Observations of the central area of M 31 allow us – in contrast to observations in the Galaxy – to monitor many novae simultaneously and proved to be prone to find many interesting SSS and nova types (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical spectroscopy of novae in M 31
Authors: Mille F. Di , Orio M. , Ciroi S. , Bianchini A. , Rafanelli P. , Nelson T. 
Published: February 2010

AbstractWe report results of a spectrophotometric survey of novae in M 31. The observations were carried out using the TNG at La Palma and the 1.82 m telescope of the INAF/OAPD at Asiago observatory. Low resolution spectra of the novae, obtained mainly in the early decline phase, allow us to classify the objects following the Tololo scheme (Williams 1992) (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)