bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Powerful Chiral Counteranion Motif for Asymmetric Catalysis
Authors: García‐García Pilar , Lay Frank , García‐García Patricia , Rabalakos Constantinos , List Benjamin 
Published: May 2009

AbstractViel Platz: Ein chirales Disulfonimid wurde als leistungsfähiges neues Motiv für die asymmetrische Katalyse entwickelt. Als erste Illustration seiner Eignung wird eine hocheffiziente enantioselektive Mukaiyama‐Aldolreaktion beschrieben (siehe Schema) und dabei ein in situ erzeugtes N‐Silylimid als tatsächlicher Katalysator angenommen.magnified image
N‐Heterocyclic Carbene Gold(I) Catalyzed Transformation of N‐Tethered 1,5‐Bisallenes to 6,7‐Dimethylene‐3‐azabicyclo[3.1.1]heptanes
Authors: Kim Soo Min , Park Ji Hoon , Kang Youn Kyung , Chung Young Keun 
Published: May 2009

AbstractTying up loose ends: The reaction of bisallenes tethered with N‐(p‐tolylsulfonamide) in the presence of a cationic gold N‐heterocyclic carbene catalyst gave new cycloisomerization products, 6,7‐dimethyleneazabicyclo[3.1.1]heptanes, in high yields (see scheme; IPr=N,N′‐bis(2,6‐diisopropylphenyl)imidazol‐2‐ylidene).magnified image
Local and Collective Motions in Precise Polyolefins with Alkyl Branches: A Combination of 2H and 13C Solid‐State NMR Spectroscopy
Authors: Wei Yuying , Graf Robert , Sworen John C. , Cheng Chi‐Yuan , Bowers Clifford R. , Wagener Kenneth B. , Spiess Hans Wolfgang 
Published: May 2009

AbstractBranching out: The mobility of linear polymers changes upon branching, which has a pronounced effect on processability and drawability. Regularly branched model polyolefins were studied by advanced solid‐state NMR spectroscopy, and twist defects around the branches in the crystalline regions are identified. For lower branch content, the twisting motions are decoupled; for higher content, collective motion is found (see picture).magnified image
Subliming the Unsublimable: How to Deposit Nanographenes
Authors: Rouhanipour Ali , Roy Mainak , Feng Xinliang , Räder Hans Joachim , Müllen Klaus 
Published: May 2009

AbstractQuite sublime: Thin‐layer fabrication of unsublimable large polycyclic aromatic hydrocarbons (PAHs) by pulsed laser deposition was used to prepare samples for scanning tunneling microscopy. Giant PAHs with up to 222 carbon atoms can be visualized—a size that was previously not possible because of the lack of suitable deposition methods.magnified image
Addition of Dimethylaminobismuth to Aldehydes, Ketones, Alkenes, and Alkynes
Authors: Nekoueishahraki Bijan , Sarish Sankaranarayana Pillai , Roesky Herbert W. , Stern Daniel , Schulzke Carola , Stalke Dietmar 
Published: May 2009

AbstractBiO chemistry: A direct regioselective route to bismuth bis(amino)naphthalene compounds, incorporating BiO and BiC bonds is described, in which an amide precursor is treated with aldehydes, ketones, alkenes, and alkynes, leading to insertion into the BiNMe2 bond.magnified image
Epoxidation of Jatropha (Jatropha curcas) oil by peroxyacids
Authors: Goud Vaibhav V. , Dinda Srikanta , Patwardhan Anand V. , Pradhan Narayan C. 
Published: May 2009

AbstractJatropha (Jatropha curcas) oil with iodine value 104 g I2/100 g, and containing 44.7% oleic acid and 31.4% linoleic acid, was epoxidised in situ with hydrogen peroxide (30%) and acetic/formic acid in the presence of catalytic amounts of sulphuric acid. We have compared the kinetics of epoxidation of jatropha oil (JO) by peroxyacetic and peroxyformic acids, in or without toluene at 30, 50, 70, and 85 °C. The effects of temperature and various mole ratios on epoxidation rate, oxirane ring stability, and iodine value of the epoxidised oil were studied, and optimum conditions were established. The rate constants for epoxidation of JO were found to be in the range 0.22–69.4 × 10−6 l.mol−1.s−1 and activation energies were found to be 64.46 KJ.mol−1, 72 KJ.mol−1, 59 KJ.mol−1, 68.24 KJ.mol−1, for peroxyacetic and peroxyformic acids in or without toluene, respectively. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Effect of hydrogen on the synthesis of carbon nanofibers by CO disproportionation on ultrafine Fe3O4
Authors: Lu Wenxin , Sui Zhijun , Zhou Jinghong , Li Ping , Zhou Xinggui , Chen De 
Published: May 2009

AbstractCarbon nanofibers (CNFs) are grown by catalytic CO disproportionation over ultrafine Fe3O4 catalyst at a hydrogen concentration of 0–29.17%, and the time‐depending rates of CNFs growth are continuously monitored and the morphologies of the as‐synthesized CNFs are analyzed. Increasing H2 concentration will lower CO dissociation energy and assist catalyst reconstruction so as to shorten the induction period and increase the growth rate of CNFs, but it will also increase the rate of catalyst deactivation because carbon hydrogasification is not possible and carbon diffusion in the catalyst particle is rate limiting. As a result of H2‐induced catalyst reconstruction and carbon deposition, the morphology of the CNFs changes from twisty to helical and to straight and becomes less entangled when the H2 concentration is increased. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
DBD regeneration of GAC loaded with acid orange 7
Authors: Qu Guang‐Zhou , Li Jie , Li Guo‐Feng , Wu Yan , Lu Na 
Published: May 2009

AbstractActivated carbon (AC) has been widely used as adsorbent in various industrial applications, such as purification of water in sewage facilities and filtration of air in toxicity‐treating factories. However, after exhaustion, AC should be regenerated and reused because of the limited resources for AC production and additional secondary pollution of spent‐carbon dumped into water or soil. In this study, a process for regenerating AC based on high active species (O3, ·OH, HO2, O2, ·RO, etc.) generated by dielectric barrier discharge (DBD) oxidation was proposed. The regeneration of granular‐activated carbon (GAC) exhausted with azo dye acid orange 7 was investigated to assay this method. The influences of the parameters, such as treatment time, electric field and gas kind, on the readsorption rate were studied systematically. The results of structural properties of GAC analyses showed that the surface area, the micropore area, external surface area, micropore volume and total volume of GAC after three cycles DBD treatment decreased to different extent. The adsorption isotherms indicated that the regeneration efficiency was about 81% after three times DBD plasma regeneration cycles, which confirmed the reuse feasibility of the regenerated GAC. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Influence of varying fiber lengths on mechanical, thermal, and morphological properties of MA‐g‐PP compatibilized and chemically modified short pineapple leaf fiber reinforced polypropylene composites
Authors: Chattopadhyay Sanjay K. , Khandal R. K. , Uppaluri Ramagopal , Ghoshal Aloke K. 
Published: May 2009

AbstractEnvironmentally benign, low cost and abundantly available short pineapple leaf fibers (PALF), found mostly in the Tropical rain forest climates are ideal materials for manufacture of thermoplastic polymer‐matrix composites. Here, mechanical and thermal properties of composites of maleic anhydride grafted polypropylene (MA‐g‐PP) and chemically modified short PALF are studied as a function of different fiber lengths at 10 vol % fibers loading with fiber orientation in the longitudinal direction. The effects of fiber lengths and fiber loading on the morphological properties are assessed via observations by scanning electron microscopy. Fiber length of 6 mm oriented longitudinally at 10 vol % fibers loading in PP is the optimum and recommended composition, where 73% increase in impact properties, 37% increase in the flexural modulus, 33% increase in flexural strength, and 14% increase in vicat softening temperature are observed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Solvent‐Directed Self‐Assembly of π Gelators to Hierarchical Macroporous Structures and Aligned Fiber Bundles
Authors: Babu Sukumaran S. , Mahesh Sankarapillai , Kartha Kalathil K. , Ajayaghosh Ayyappanpillai 
Published: May 2009

AbstractMorphology variation: The Boc‐alanine linked OPV exhibits an unprecedented formation of periodic macroporous honeycomb structures in chloroform and aligned fiber bundles in toluene (see SEM images). This represents a unique example for a distinct morphology change of an organogelator from macroporous honeycomb to aligned fiber bundles upon changing the solvent.magnified image
Review: The liver bile acid‐binding proteins
Authors: Monaco Hugo L. 
Published: May 2009

AbstractThe liver bile acid‐binding proteins, L‐BABPs, formerly called the liver “basic” fatty acid‐binding proteins, are a subfamily of the fatty acid‐binding proteins, FABPs. All the members of this protein group share the same fold: a 10 stranded β barrel in which two short helices are inserted in between the first and the second strand of antiparallel β sheet. The barrel encloses the ligand binding cavity of the protein while the two helices are believed to be involved in ligand accessibility to the binding site. The L‐BABP subfamily has been found to be present in the liver of several vertebrates: fish, amphibians, reptiles, and birds but not in mammals. The members of the FABP family present in mammals that appear to be more closely related to the L‐BABPs are the liver FABPs and the ileal BABPs, both very extensively studied. Several L‐BABP X‐ray structures are available and chicken L‐BABP has also been studied using NMR spectroscopy. The stoichiometry of ligand binding for bile acids, first determined by X‐ray crystallography for the chicken liver protein, is of two cholates per protein molecule with the only exception of zebrafish L‐BABP which, due to the presence of a disulfide bridge, has a stoichiometry of 1:1. The stoichiometry of ligand binding for fatty acids, determined with several different techniques, is 1:1. An unanswered question of great relevance is the identity of the protein that in mammals performs the function that in other vertebrates is carried out by the L‐BABPS. © 2009 Wiley Periodicals, Inc. Biopolymers 91: 1196–1202, 2009.This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
An experimental wireless sensor network applied in engineering courses
Authors: Aguilar Leocundo , Licea Guillermo , García‐Macías J. Antonio 
Published: May 2009

AbstractWireless sensor networks (WSNs) are an emerging technology based on the progress of electrical and mechanical engineering, as well as computer science in the last decade. This paper presents our experiences in designing and developing a WSN using commercial‐off‐the‐shelf components and assembled in‐house. This WSN is used as a support tool for teaching in undergraduate engineering programs in Electronic and Computing, providing students a hands‐on experience with emphasis on embedded software design. © 2009 Wiley Periodicals, Inc. Comput Appl Eng Educ 19: 777–786, 2011
Multiresolution foliage for forest rendering
Authors: Deng Qingqiong , Zhang Xiaopeng , Yang Gang , Jaeger Marc 
Published: May 2009

AbstractPlants are important objects in virtual environments. High complexity of shape structure is found in plant communities. Level of detail (LOD) of plant geometric models becomes important for interactive forest rendering. We emphasize three major problems in current research: the time consumption in LOD model construction and extraction, the balance between visual effect and data compression, and the time consumption in the communication between Central Processing Unit (CPU) and Graphics Processing Unit (GPU). We present a new foliage simplification framework for LOD model and forest rendering. By an uneven subdivision of the tree crown volume, the cost for LOD model construction is drastically reduced. With a GPU‐oriented design of LOD storage structure for foliage, the costly hierarchical traversal of a binary tree is replaced by a sequential lookup of an array. The structure also decreases the communication between the CPU and the GPU in rendering. In addition, Leaf density is introduced to adapt compression to the local distribution of leaves, so that more visually relevant details are kept. According to foliage nature (broad leaves or needles), higher compression are finally reached using mixed polygon/line models. This framework is implemented on virtual scenes of simulated trees with high detail. Copyright © 2009 John Wiley & Sons, Ltd.
Functional Dissection of a Multimodular Polypeptide of the Pikromycin Polyketide Synthase into Monomodules by Using a Matched Pair of Heterologous Docking Domains
Authors: Yan John , Gupta Shuchi , Sherman David H. , Reynolds Kevin A. 
Published: May 2009

AbstractWorking together or apart: Separating multimodular PKS enzymes into their respective monomodules by replacing the natural intraprotein linkers (illustrated in red in the figure) with a matched docking domain pair from a heterologous PKS system, leads to only small losses in overall in vivo polyketide product and increased efficiency at utilizing polyketide pathway intermediates to prime the biosynthetic process.magnified imageThe pikromyin polyketide synthase (PKS) in Streptomyces venezulae is comprised of a loading module and six extension modules, which generate the corresponding 14‐membered macrolactone product. PikAI is a multimodular component of this PKS and houses both the loading domain and the first two extension modules, joined by short intraprotein linkers. We have shown that PikAI can be separated into two proteins at either of these linkers, only when matched pairs of docking domains (DDs) from a heterologous modular phoslactomycin PKS are used in place of the intraprotein linker. In both cases the yields of pikromycin produced by the S. venezuelae mutant were 50 % of that of a S. venezuelae strain expressing the native trimodular PikAI. This observation provides the first demonstration that such separations do not dramatically impact the efficiency of the entire in vivo biosynthetic process. Expression of module 2 as a monomodular protein fused to a heterologous N‐terminal docking domain was also observed to give almost a tenfold improvement in the in vivo generation of pikromycin from a synthetic diketide intermediate. These results demonstrate the utility of DDs to manipulate biosynthetic processes catalyzed by modular PKSs and the quest to generate novel polyketide products.
Total Syntheses of a Conformationally Locked North‐Type Methanocarba Puromycin Analogue and a Dinucleotide Derivative
Authors: Michel Benoît Y. , Strazewski Peter 
Published: May 2009

AbstractLocked in translation: Crucial insight into the ribosomal catalysis of peptide‐bond formation is expected to be gained from the target compounds, which feature conformational locking in a North‐type pucker, designed to interfere with the translation of the genetic code. The compounds were prepared from D‐ribose in 18 and 19 steps by a multi‐step synthetic route described here (see scheme).magnified imageAn original synthetic approach for the first synthesis of an enantiopure methanocarba puromycin (3′‐α‐aminoacylamino‐3′‐deoxyadenosine) analogue and its cytidine dinucleotide derivative is described. Each compound is conformationally locked in a North‐type pucker and exhibits both a pseudoaxial hydroxy group and a pseudoequatorial aminoacyl group. The syntheses were accomplished from D‐ribose in 18 and 19 steps, respectively, with key steps being a ring‐closing metathesis, a Luche reduction, a Simmons–Smith cyclopropanation, a Mitsunobu coupling, a Mattocks bromoacetylation, a regioselective and a stereoselective nucleophilic substitution, a chemoselective phosphoramidite coupling and a Staudinger–Vilarrasa coupling. Both molecules are being tested for peptidyl transfer efficiency in ribosomes for comparison with the peptidyl transfer kinetics of natural puromycin and other natural and synthetic ribosomal A site substrates.
Calculational Study of Fluoroammonium and Related Cations and Dications
Authors: Olah George A. , Prakash G. K. Surya , Rasul Golam 
Published: May 2009

AbstractStructures as well as 15N and 19F NMR chemical shifts of a series of fluoroammonium ions were studied by ab initio/GIAO‐SCF, GIAO‐MP2 and GIAO‐CCSD(T) methods. Calculated 15N and 19F NMR chemical shifts correlate well with the experimental data. The relative stabilities as well as the charge of the central nitrogen atom of fluoro‐substituted tetrahedral ammonium ions were found to increase linearly with the increasing number of fluorine substituents due to their strong electron‐withdrawing inductive effect. Similarly the magnitude of 15N NMR chemical shifts also increase linearly with the increasing number of fluorine substituents in accord with the strong deshielding effect of fluorine. Structures as well as 15N and 19F NMR chemical shifts of yet experimentally unknown fluoroammonium dications were also computed.
Interplay of Interactions Governing the Dynamic Conversions of Acyclic and Macrocyclic Helicates
Authors: Campbell Victoria E. , de Hatten Xavier , Delsuc Nicolas , Kauffmann Brice , Huc Ivan , Nitschke Jonathan R. 
Published: May 2009

AbstractSystemic change: A system of transformations between helical structures was observed to be governed by interactions mediated by the electronic effects of substituents, entropic effects, the conformational preferences of organic building blocks, and the coordinative preferences of the metal ion. All of these effects were important, but all must be considered together to allow the prediction of the product observed (see scheme).magnified imageA rigid, helical macrocycle that contains two copper(I) ions has been synthesized through subcomponent self‐assembly. Although it does not obey the “rule of coordinative saturation”, this macrocycle could be prepared through subcomponent substitution starting from a tri(copper(I)) helicate, in a reaction in which copper(I) was ejected. The macrocycle was observed to readily participate in a sequence of transformations between helical structures mediated by the electronic effects of substituents, entropic effects, the conformational preferences of organic building blocks, and the coordinative preferences of the metal ion. The thermodynamic parameters governing the interconversion of an “open” helicate and the “closed” macrocycle were determined through van ‘t Hoff analysis, allowing quantification of the entropic driving force for macrocyclization.
ChemInform Abstract: Structure and Aromaticity of B6H5+ Cation: A Novel Borhydride System Containing Planar Pentacoordinated Boron
Authors: Yu Hong‐Lang , Sang Rui‐Li , Wu Yun‐Ying 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Crystal Growth of Inter‐Lanthanide LaLn′O3 (Ln′: Y, Ho—Lu) Perovskites from Hydroxide Fluxes.
Authors: Bharathy M. , Fox Adam H. , Mugavero S. J. , zur Loye H.‐C. 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Porous Bi2WO6 Thin Films as Efficient Visible‐Light‐Active Photocatalysts.
Authors: Zhang Li‐Wu , Wang Ya‐Jun , Cheng Han‐Yun , Yao Wen‐Qing , Zhu Yong‐Fa 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Mechanochemical Synthesis of AlF3 with NH4F as Fluorinating Agent — Does It Work?
Authors: Scholz G. , Kemnitz E. 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Electrodeposition of 3D Ordered Macroporous Germanium from Ionic Liquids: A Feasible Method to Make Photonic Crystals with a High Dielectric Constant.
Authors: Meng Xiangdong , Al‐Salman Rihab , Zhao Jiupeng , Borissenko Natalia , Li Yao , Endres Frank 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Electrochemical and Chemical Oxidation of [Pt2(μ‐Pyrophosphite)4]4‐ Revisited: Characterization of a Nitrosyl Derivative, [Pt2(μ‐pyrophosphite)4(NO)]3‐.
Authors: Bennett Martin A. , Bhargava Suresh K. , Bond Alan M. , Bansal Vipul , Forsyth Craig M. , Guo Si‐Xuan , Priver Steven H. 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Highly Efficient Organocatalyzed Direct Asymmetric Aldol Reactions of Hydroxyacetone and Aldehydes.
Authors: Wu Xiaoyu , Ma Zhixiong , Ye Zhengqing , Qian Shan , Zhao Gang 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Synthesis of Melatonin Receptor Agonist Ramelteon via Rh‐Catalyzed Asymmetric Hydrogenation of an Allylamine.
Authors: Yamashita Masayuki , Yamano Toru 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Reduction of Alkyl Halides by Triethylsilane Based on a Cationic Iridium Bis(phosphinite) Pincer Catalyst: Scope, Selectivity and Mechanism.
Authors: Yang Jian , Brookhart Maurice 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.
ChemInform Abstract: Electron‐Deficient Phosphines Accelerate the Heck Reaction of Electron‐Rich Olefins in Ionic Liquid.
Authors: Liu Shifang , Saidi Ourida , Berry Neil , Ruan Jiwu , Pettman Alan , Thomson Nick , Xiao Jianliang 
Published: May 2009

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.