bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of a virtual winder for computer‐aided education using Virtools
Authors: Liu Jihong , Jiang Hongxia 
Published: April 2011

AbstractSince operation of virtual winder can relieve the problem of lack of experiment on real equipments, virtual winder can be valuable complements to physical winder operation experiment. Virtools is the most widely used software for creating 3D VR environment. In this article, using Virtools to construct a virtual winder is demonstrated in detail by dividing the whole process into five steps: (1) creates 3D winder models in 3ds Max; (2) exports the models to Virtools format using Expert plugins (3ds Max Exporter); (3) designs scenes including cameras and lighters; (4) constructs the virtual winder including Behavior Building Block (BB), Scripts, and Virtools Scripting Language (VSL); (5) synthesizes and exports interactive coursewares of the virtual winder. The considerations and discussions in this article may be useful for building system of virtual education equipment in other subject areas. © 2011 Wiley Periodicals, Inc. Comput Appl Eng Educ 22: 120–130, 2014
Application of Cross‐Flow Microfiltration for Purifying Solvent Naphtha with Ceramic Membranes
Authors: Zeng J. , Zheng L. , Sun X. , He Q. 
Published: April 2011

AbstractThe microfiltration process of solvent naphtha 200 containing impurities was studied using multichannel ceramic membranes with pore diameters of 0.5 and 0.8 μm. The effects of operating time, transmembrane pressure, cross‐flow velocity, and temperature on permeate flux and rejection were investigated. The scanning electron microscop and energy dispersive spectrometry were conducted for the clean and fouled membranes. Effect of backflushing on permeate flux was also studied. Results show that it is possible to recover over 94 % of the original flux by a program of backflushing. A concentration process was carried out and furthermore, various membrane resistances were calculated. Finally, commercial detergent, HNO3, and NaOH + NaClO cleaning stages were used for the 0.5‐μm membrane.
In Situ Microscopy for Online Monitoring of Enzymatic Processes
Authors: Prediger A. , Bluma A. , Höpfner T. , Lindner P. , Beutel S. , J. Müller J. , Hilterhaus L. , Liese A. , Scheper T. 
Published: April 2011

AbstractIn situ Microscopy (ISM) is an optical analysis method that allows non‐invasive monitoring of processes in real‐time. In this article online monitoring of enzyme carriers and the determination of their mechanical stability are presented as new application areas for ISM. As proof of principle the fragmentation of Lewatit VP OC 1600 particles in a stirred tank reactor is tracked. The image algorithm that was used to analyze the acquired image data is described and the results of the stability study are shown. Additional application possibilities of ISM in the area of two‐phase systems are demonstrated.
Calcium Manganese Oxides as Oxygen Evolution Catalysts: O2 Formation Pathways Indicated by 18O‐Labelling Studies
Authors: Shevela Dmitriy , Koroidov Sergey , Najafpour M. Mahdi , Messinger Johannes , Kurz Philipp 
Published: April 2011

AbstractOxygen evolution catalysed by calcium manganese and manganese‐only oxides was studied in 18O‐enriched water. Using membrane‐inlet mass spectrometry, we monitored the formation of the different O2 isotopologues 16O2, 16O18O and 18O2 in such reactions simultaneously with good time resolution. From the analysis of the data, we conclude that entirely different pathways of dioxygen formation catalysis exist for reactions involving hydrogen peroxide (H2O2), hydrogen persulfate (HSO5−) or single‐electron oxidants such as CeIV and [RuIII(bipy)3]3+. Like the studied oxide catalysts, the active sites of manganese catalase and the oxygen‐evolving complex (OEC) of photosystem II (PSII) consist of μ‐oxido manganese or μ‐oxido calcium manganese sites. The studied processes show very similar 18O‐labelling behaviour to the natural enzymes and are therefore interesting model systems for in vivo oxygen formation by manganese metalloenzymes such as PSII.
The Remarkable Enhancement of CO‐Pretreated CuOMn2O3/γ‐Al2O3 Supported Catalyst for the Reduction of NO with CO: The Formation of Surface Synergetic Oxygen Vacancy
Authors: Li Dan , Yu Qiang , Li Shan‐Shan , Wan Hai‐Qin , Liu Lian‐Jun , Qi Lei , Liu Bin , Gao Fei , Dong Lin , Chen Yi 
Published: April 2011

AbstractNO reduction by CO was investigated over CuO/γ‐Al2O3, Mn2O3/γ‐Al2O3, and CuOMn2O3/γ‐Al2O3 model catalysts before and after CO pretreatment at 300 °C. The CO‐pretreated CuOMn2O3/γ‐Al2O3 catalyst exhibited higher catalytic activity than did the other catalysts. Based on X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), UV/Vis diffuse reflectance spectroscopy (DRS), Raman, and H2‐temperature‐programmed reduction (TPR) results, as well as our previous studies, the possible interaction model between dispersed copper and manganese oxide species as well as γ‐Al2O3 surface has been proposed. In this model, Cu and Mn ions occupied the octahedral vacant sites of γ‐Al2O3, with the capping oxygen on top of the metal ions to keep the charge conservation. For the fresh CuO/γ‐Al2O3 and Mn2O3/γ‐Al2O3 catalysts, the ‐Cu‐O‐Cu‐ and ‐Mn‐O‐Mn‐ species were formed on the surface of γ‐Al2O3, respectively; but for the fresh CuOMn2O3/γ‐Al2O3 catalyst, ‐Cu‐O‐Mn‐ species existed on the surface of γ‐Al2O3. After CO pretreatment, ‐Cu‐□‐Cu‐ and ‐Mn‐□‐Mn‐ (□ represents surface oxygen vacancy (SOV)) species would be formed in CO‐pretreated CuO/γ‐Al2O3 and CO‐pretreated Mn2O3/γ‐Al2O3 catalysts, respectively; whereas ‐Cu‐□‐Mn‐ species existed in CO‐pretreated CuOMn2O3/γ‐Al2O3. Herein, a new concept, surface synergetic oxygen vacancy (SSOV), which describes the oxygen vacancy formed between the individual Mn and Cu ions, is proposed for CO‐pretreated CuO‐Mn2O3/γ‐Al2O3 catalyst. In addition, the role of SSOV has also been approached by NO temperature‐programmed desorption (TPD) and in situ FTIR experiments. The FTIR results of competitive adsorption between NO and CO on all the CO‐pretreated CuO/γ‐Al2O3, Mn2O3/γ‐Al2O3, and CuOMn2O3/γ‐Al2O3 samples demonstrated that NO molecules mainly were adsorbed on Mn2+ and CO mainly on Cu+ sites. The current study suggests that the properties of the SSOVs in CO‐pretreated CuOMn2O3/γ‐Al2O3 catalyst were significantly different to SOVs formed in CO‐pretreated CuO/γ‐Al2O3 and Mn2O3/γ‐Al2O3 catalysts, and the SSOVs played an important role in NO reduction by CO.
Energy‐Level Tailoring in a Series of Redox‐Rich Quinonoid‐Bridged Diruthenium Complexes Containing Tris(2‐pyridylmethyl)amine as a Co‐Ligand
Authors: Weisser Fritz , Huebner Ralph , Schweinfurth David , Sarkar Biprajit 
Published: April 2011

AbstractReactions of [{Ru(tmpa)}2(μ‐Cl)2][ClO4]2, (2[ClO4]2, tmpa=tris(2‐pyridylmethyl)amine) with 2,5‐dihydroxy‐1,4‐benzoquinone (L1), 2,5‐di‐[2,6‐(dimethyl)‐anilino]‐1,4‐benzoquinone (L2), or 2,5‐di‐[2,4,6‐(trimethyl)‐anilino)]‐1,4‐benzoquinone (L3) in the presence of a base led to the formation of the dinuclear complexes [{Ru(tmpa)}2(μ‐L1−2 H)][ClO4]2 (3[ClO4]2), [{Ru(tmpa)}2(μ‐L2−2 H)][ClO4]2 (4[ClO4]2), and [{Ru(tmpa)}2(μ‐L3−2 H)][ClO4]2 (5[ClO4]2). Structural characterization of 5[ClO4]2 showed the localization of the double bonds within the quinonoid ring and a twisting of the mesityl substituents with respect to the quinonoid plane. Cyclic voltammetry of the complexes show two reversible oxidation and quinonoid‐based reduction processes. Results obtained from UV/Vis/NIR and EPR spectroelectrochemistry are invoked to discuss ruthenium‐ versus quinonoid‐ligand‐centered redox activity. The complex 3[ClO4]2 is compared to the reported complex [{Ru(bpy)}2(μ‐L1−2 H)]2+ (12+, bpy=2,2′‐bipyridine). The effects of substituting the bidentate and better π‐accepting bpy co‐ligands with tetradentate tmpa ligands [pure σ‐donating (amine) as well as σ‐donating and π‐accepting (pyridines)] on the redox and electronic properties of the complexes are discussed. Comparisons are also made between complexes containing the dianionic forms of the all‐oxygen‐donating L1 ligand with the L2 and L3 ligands containing an [O,N,O,N] donor set. The one‐electron oxidized forms of the complexes show absorption in the NIR region. The position as well as the intensity of this band can be tuned by the substituents on the quinonoid bridge. In addition, this band can be switched on and off by using tunable redox potentials, making such systems attractive candidates for NIR electrochromism.
Nitrogen Dynamics and Reactivity of Chiral Aziridines: Generation of Configurationally Stable Aziridinyllithium Compounds
Authors: Degennaro Leonardo , Mansueto Rosmara , Carenza Elisa , Rizzi Rosanna , Florio Saverio , Pratt Lawrence M. , Luisi Renzo 
Published: April 2011

AbstractDiastereomeric oxazolinylaziridines (R,R)‐9 and (R,S)‐9 have been regioselectively lithiated at the α‐position with respect to the oxazolinyl ring. The resulting aziridinyllithium compounds proved to be chemically and configurationally stable under the experimental conditions used, thus furnishing, upon trapping with electrophiles, chiral 2,2‐disubstituted aziridines, in contrast to the corresponding α‐lithiated oxazolinyloxiranes that have been reported to be chemically stable but configurationally unstable. This peculiar behavior of the nitrogen‐bearing heterocycle has been rationalized on the basis of DFT calculations and the observed dynamics of the aziridine nitrogen atom. The DFT analysis allowed the disclosure of a solvent‐dependent differing stability of diastereomeric lithiated aziridines (R,R)‐9‐Li and (R,S)‐9‐Li, suggesting η3‐coordinated oxazolinylaziridinyllithium compounds as likely intermediates. Such intermediates could be the result of a dynamically controlled lithiation that relies on the preliminary formation of a complex between the lithiating agent and the oxazolinyl ring. According to this model, the competing complexation of the lithiating agent by the lone pair of electrons on the aziridine nitrogen would cause addition to the oxazoline CN bond, thus ending up with the formation of oxazolidines, which are precursors of useful chiral ketoaziridines. The proposed model has been also supported by estimating the nitrogen inversion barrier by dynamic NMR spectroscopic experiments.
Electron Exchange Columns through Entrapment of a Nickel Cyclam in a Sol–Gel Matrix
Authors: Lavi Yair , Burg Ariela , Maimon Eric , Meyerstein Dan 
Published: April 2011

AbstractAn electron exchange column (analogous to ion exchange columns) was developed using the unique redox properties of the nickel–tetraazamacrocyclic complexes (nickel cyclam [NiIIL1]2+) and nickel–trans‐III‐meso‐5,7,7,12,14,14‐hexamethyl‐1,4,8,11‐tetraazacyclotetradecane, ([NiIIL2]2+), and the physical and chemical stability of the ceramic materials using the sol–gel process to entrap the complexes. The entrapment by the biphasic sol–gel method is based on non‐covalent bonds between the matrix and the complex; therefore the main problem was leaching. Parameters controlling the leaching were investigated. Redox cycles with the reducing agent ascorbic acid, and persulfate as the oxidizing agent were performed.
Degradable Dual pH‐ and Temperature‐Responsive Photoluminescent Dendrimers
Authors: Shen Youqing , Ma Xinpeng , Zhang Bo , Zhou Zhuxian , Sun Qihang , Jin Erlei , Sui Meihua , Tang Jianbin , Wang Jinqiang , Fan Maohong 
Published: April 2011

AbstractPoly(β‐aminoester) dendrimers have been prepared. These systems represent the first degradable dual pH‐ and temperature‐responsive dendrimers displaying photoluminescence. The pH/temperature sensitivities are interrelated; the lower critical solution temperature of the dendrimer decreases as the pH of the solution is increased. The sensitivities are mainly due to phase changes of the surface groups with changes in pH or temperature. These dual‐responsive dendrimers are very useful in drug delivery. They may be loaded with a hydrophobic drug at low temperature without using organic solvents. The loaded drug is released very slowly and steadily at 37 °C and physiological pH, but can be quickly released at acidic pH, for example the lysosomal pH (pH 4–5), for intracellular drug release. These dendrimers also display strong photoluminescence, which can be exploited for monitoring drug loading and release. Thus, poly(β‐aminoester) dendrimers constitute ideal drug carriers since their thermal sensitivity allows the loading of drugs without using organic solvents, their pH sensitivity permits fast intracellular drug release, and their photoluminescence provides a means of monitoring drug loading and release.
Triptycene‐Derived Oxacalixarenes as New Wheels for the Synthesis of [2]Rotaxanes: Acid–Base‐ and Metal‐Ion‐Switchable Complexation Processes
Authors: Hu Shu‐Zhen , Chen Chuan‐Feng 
Published: April 2011

AbstractA pair of triptycene‐derived oxacalixarenes, 1 a and 1 b, containing two naphthyridine subunits have been synthesized by a convenient one‐pot approach. Macrocycles 1 a and 1 b are diastereomers, with 1 a being a cis isomer with a boat‐like 1,3‐alternate conformation and 1 b being a trans isomer with a curved boat‐like conformation in the solid state. Both 1 a and 1 b have fixed conformations in solution at room temperature, as revealed by variable‐temperature 1H NMR spectroscopy experiments. It was found that oxacalixarenes 1 a and 1 b could both form 1:1 [2]pseudorotaxane‐type complexes with paraquat derivatives with different functional groups in solution and in the solid state, which resulted in the further synthesis of a pair of novel isomeric [2]rotaxanes. Moreover, the controlled dethreading and rethreading processes of the [2]pseudorotaxanes were also easily achieved by acid–base stimuli or Hg2+ association/dissociation.
Oligopyrrole Macrocycles: Receptors and Chemosensors for Potentially Hazardous Materials
Authors: Rambo Brett M. , Sessler Jonathan L. 
Published: April 2011

AbstractOligopyrroles represent a diverse class of molecular receptors that have been utilized in a growing number of applications. Recently, these systems have attracted interest as receptors and chemosensors for hazardous materials, including harmful anionic species, high‐valent actinide cations, and nitroaromatic explosives. These versatile molecular receptors have been used to develop rudimentary colorimetric and fluorimetric assays for hazardous materials.
Evaluation of phosphinoamidoester‐derived Pd catalysts in the asymmetric allylic alkylation reaction: Theoretical studies and mechanistic insights
Authors: Marinho Vanda R. D. , Ramalho J.P.Prates , Rodrigues Ana Isabel , Burke Anthony J. 
Published: April 2011

AbstractTwo simple hemilabile P,O‐coordinating phosphinoamidoester ligands 6a and 6b were synthesized and studied in the Pd(0)‐catalyzed asymmetric allylic alkylation of rac‐1,3‐diphenylpropenyl acetate affording a highest ee of 83% ee with 6a. To gain an insight into the actual mechanism of this catalytic reactions, which had previously been investigated with a first generation family of P,O‐coordinating phosphinoamido‐alcohol ligands—4a and 4b—a semiempirical computational study was carried out with the Pd‐allyl complexes formed from both 4a and 6a including Hitchcock's phosphinoamido‐alcohol ligand 5 (R1 = H, R2 = Ph). The results of this study substantiate a working model that has previously been proposed for this reaction using hemilabile P,O‐coordinating phosphinoamido‐type ligands. Chirality 2011 © 2011 Wiley‐Liss, Inc
Organocatalytic aza‐Michael/retro‐aza‐Michael reaction: Pronounced chirality amplification in aza‐Michael reaction and racemization via retro‐aza‐Michael reaction
Authors: Cai Yong‐Feng , Li Li , Luo Meng‐Xian , Yang Ke‐Fang , Lai Guo‐Qiao , Jiang Jian‐Xiong , Xu Li‐Wen 
Published: April 2011

AbstractA detailed experimental investigation of an aza‐Michael reaction of aniline and chalcone is presented. A series of Cinchona alkaloid‐derived organocatalysts with different functional groups were prepared and used in the aza‐Michael and retro‐aza‐Michael reaction. There was an interesting finding that a complete reversal of stereoselectivity when a benzoyl group was introduced to the cinchonine and cinchonidine. The chirality amplification vs. time proceeds in the quinine‐derived organocatalyst containing silicon‐based bulky group, QN‐TBS, ‐catalyzed aza‐Michael reaction under solvent‐free conditions. In addition, we have demonstrated for the first time that racemization was occurred in suitable solvents under mild conditions due to retro‐aza‐Michael reaction of the Michael adduct of aniline with chalcone. These indicate the equilibrium of retro‐aza‐Michael reaction and aza‐Michael reaction produce the happening of chirality amplification in aza‐Michael reaction and racemization via retro‐aza‐Michael reaction under different conditions, which would be beneficial to the development of novel chiral catalysts for the aza‐Michael reactions. Chirality, 2011. © 2011 Wiley‐Liss, Inc.
Growth of Textured Adenine Thin Films to Exhibit only Chiral Faces
Authors: Capitán María Jose , Otero Roberto , Álvarez Jesús , Miranda Rodolfo 
Published: April 2011

AbstractThe growth of adenine on Au(111) from the submonolayer up to several microns film thickness is studied by combining STM and surface X‐ray diffraction techniques. The study shows that adenine thin films are composed of highly textured crystallites with the reported α‐adenine crystal structure in such a way that they only exhibit (001)‐faces. Such faces, with chiral p2 symmetry planes, have an average size of 15 nm. Thus, the formed adenine films reported herein, which expose only chiral and biocompatible faces, might find applications such as enantioselective heterogeneous catalysts for the chemical and pharmaceutical industries.
Urovysion: Considerations on modifying current evaluation scheme, including immunophenotypic targeting and locally set, statistically derived diagnostic criteria
Authors: Pajor Gabor , Somogyi Laszlo , Melegh Bela , Alpar Donat , Kajtar Bela , Farkas Laszlo , Kneif Maria , Bollmann Daniel , Pajor Laszlo , Sule Norbert 
Published: April 2011

AbstractUrovysion multitarget fluorescence in situ hybridization (FISH) assay is a promising tool for detection of bladder cancer, however, there is still no consensus regarding abnormal signal pattern and cut‐off level, and the recommended targeting carries limitations similar to urine cytology. Aim of this study was to explore diagnostic benefits of a recently introduced method featuring target specific genotyping, as well as to investigate the feasibility of locally and statistically determined cut‐off, compared with conventional evaluation scheme. Histology, cytology, and comparative FISH approaches were performed on 42 patients with high clinical suspicion for urothelial carcinoma (UC). FISH parallels were (1) Urovysion‐alone (according to manufacturer's instruction); (2) Targeted‐Urovysion (cytokeratin7 immunophenotyping followed by Urovysion), both of which evaluated by both conventional and statistical evaluation scheme. For statistical evaluation cut‐offs and sufficient sample size were determined on controls and ratio of positive cells was recorded, whereas conventional evaluation relied on manufacturer's recommendations. The specificity of cytology, Urovysion‐alone in general and targeted‐Urovysion in general appeared 86%, 86%, and 100%, respectively. In the same comparison, overall sensitivity was 60%, 80%, and 93%, respectively. In superficial cases sensitivity was 48% for cytology, 72% for Urovysion‐alone and 91% for targeted‐Urovysion, while no prominent differences were seen in muscle invasive cases. The ratio of FISH positive cells was proportionate with both stage and grade, however, targeted genotyping could separate high grade/high stage cases more effectively. In conclusion, CK7 targeting raises diagnostic efficiency of Urovysion, and could be an ideal tool for identifying tumor cells in ambiguous cases or when other tumors are present. Statistical evaluation produces accuracy comparable with results of conventional evaluation, and with laboratories setting cut‐offs individually but according harmonized protocol, it could aid method standardization. Furthermore, by providing additional quantitative information about tumor characteristics, is likely to have therapy relevant value in the future. © 2011 International Society for Advancement of Cytometry
Decode‐and‐forward with full‐duplex relaying
Authors: Rui Xianyi , Hou Jia , Zhou Liulei 
Published: April 2011

SUMMARYThis paper addresses the full‐duplex relaying. Some expressions for outage and average capacity of a two‐hop cooperative system with a full‐duplex relay are derived under an independent but not identically distributed Rayleigh fading environment. Using these expressions, we provide the performance analysis without Monte Carlo simulations. The impact of interference between the relay output and input is investigated. Copyright © 2011 John Wiley & Sons, Ltd.
Imaging adhesion and signaling dynamics in Xenopus laevis growth cones
Authors: Santiago‐Medina Miguel , Myers Jonathan P. , Gomez Timothy M. 
Published: April 2011

AbstractXenopus laevis provides a robust model system to study cellular signaling and downstream processes during development both in vitro and in vivo. Intracellular signals must function within highly restricted spatial and temporal domains to activate specific downstream targets and cellular processes. Combining the versatility of developing Xenopus neurons with advances in fluorescent protein biosensors and imaging technologies has allowed many dynamic cellular processes to be visualized. This review will focus on the techniques we use to visualize and measure cell signaling, motility and adhesion by quantitative fluorescence microscopy in vitro and in vivo. © 2011 Wiley Periodicals, Inc. Develop Neurobiol 72: 585–599, 2012
Msx1 and Msx2 in limb mesenchyme modulate digit number and identity
Authors: Bensoussan‐Trigano Vardina , Lallemand Yvan , Saint Cloment Cécile , Robert Benoît 
Published: April 2011

AbstractMsx1 and Msx2 encode homeodomain transcription factors that play a crucial role in limb development. However, the limb phenotype of the double Msx1null/null
Msx2null/null mutant is difficult to analyze, particularly along the anteroposterior axis, because of the complex effects of the double mutation on both ectoderm‐ and mesoderm‐derived structures. Namely, in the mutant, formation of the apical ectodermal ridge (AER) is impaired anteriorly and, consequently, the subjacent mesenchyme does not form. Using the Cre/loxP system, we investigated the respective roles of Msx genes in ectoderm and mesoderm by generating conditional mutant embryos with no Msx activity solely in the mesoderm. In these mutants, the integrity of the ectoderm‐derived AER was maintained, allowing formation of the anterior mesenchyme. With this strategy, we demonstrate that mesenchymal expression of Msx1 and Msx2 is required for proper Shh and Bmp4 signaling to specify digit number and identity. Developmental Dynamics 240:1190–1202, 2011. © 2011 Wiley‐Liss, Inc.