bluuebunny/crossref_metadata_2025_split huggingface dataset:
Aldol reaction catalyzed by a hydrophilic catalyst in aqueous micelle as an enzyme mimic system
Authors: Zhang Hefeng , Zhao Wenshan , Zou Jun , Liu Yi , Li Runtao , Cui Yuanchen 
Published: July 2008

AbstractChitosan‐supported L‐proline complex was synthesized and applied as a catalyst for the direct asymmetric aldol reaction in various organic solvents and water as well. It was found that the novel synthesized catalyst was able to efficiently catalyze the aldol reaction in various media. The catalytic capacity and stereoselectivity of the catalyst were obviously improved with the introduction of aqueous micelle, possibly because the micelle functioned as a hydrophobic pocket, like the hydrophobic portion in enzymes. Moreover, the present synthetic catalyst showed performance similar to that of enzymes and could be used as a model of enzyme catalysis to help better understand the mystic mechanism of enzymes. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Enantioselective separation and degradation of the herbicide dichlorprop methyl in sediment
Authors: Ma Yun , Xu Chao , Wen Yuezhong , Liu Weiping 
Published: July 2008

AbstractChiral pesticides currently constitute about 50% of all pesticides dosage used in China, and this ratio is increasing as more complex structures are introduced. Dichlorprop methyl (DCPPM) is a chiral herbicide consisting of a pair of enantiomers. In this study, the enantiomeric separation of DCPPM was investigated by gas chromatography (GC) and high‐performance liquid chromatography (HPLC) using chiral stationary phases (CSPs), and its enantiomeric degradation was characterized using a DCPPM‐degrading bacterial strain isolated from an activated sludge from a textile‐printing wastewater treatment plant. Baseline separation by both GC and HPLC was achieved. Incubation with DCPPM‐degrading bacteria in different pH solutions showed that the R enantiomer was preferentially degraded over the S enantiomer of DCPPM. The degradation rate constant decreased with increasing pH in the order of kpH5 ≈ kpH7 >kpH9. In comparison, the enantioselectivity as indicated by EF followed the order of pH 7 > pH 9–pH 5. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Microscale chiral HPLC in support of pharmaceutical process research
Authors: Welch Christopher J. 
Published: July 2008

AbstractSome recent developments in the use of microscale chiral HPLC for supporting pharmaceutical process research are reviewed, including multiparallel high throughput analysis to support high throughput experimentation studies, rapid multiparallel chromatographic method development, and on‐line reaction monitoring. Green chemistry advantages of the approach include greatly reduced solvent consumption, waste generation, and stationary phase requirement relative to conventional chiral HPLC. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
Molecular and supramolecular chirality: R2PI spectroscopy as a tool for the gas‐phase recognition of chiral systems of biological interest
Authors: Speranza Maurizio , Rondino Flaminia , Satta Mauro , Paladini Alessandra , Giardini Anna , Catone Daniele , Piccirillo Susanna 
Published: July 2008

AbstractIn life sciences, diastereomeric chiral molecule/chiral receptor complexes are held together by a different combination of intermolecular forces and are therefore endowed with different stability and reactivity. Determination of these forces, which are normally affected in the condensed phase by solvent and supramolecular interactions, can be accomplished through the generation of diastereomeric complexes in the isolated state and their spectroscopic investigation. This review presents a detailed discussion of the mass resolved Resonant Two Photon Ionization (R2PI‐TOF) technique in supersonic beams and introduces an overview of various other technologies currently available for the spectroscopic study of gas phase chiral molecules and supramolecular systems. It reports case studies primarily from our recent work using R2PI‐TOF methodology for chiral recognition in clusters containing molecules of biological interest. The measurement of absorption spectra, ionization and fragmentation thresholds of diastereomeric clusters by this technique allow the determination of the nature of the intrinsic interactions, which control their formation and which affect their stability and reactivity. Chirality, 2009. © 2008 Wiley‐Liss, Inc.
An operative approach to correct CD spectra distortions due to absorption flattening
Authors: Castiglioni Ettore , Lebon France , Longhi Giovanna , Gangemi Roberto , Abbate Sergio 
Published: July 2008

AbstractWe discuss the influence of absorption flattening (AF) on CD spectra, aiming at finding a simple way to compensate the induced distortions. A simple algebraic formalism is proposed based on an unconventional measuring approach, which makes use of a commercial unit. Validation of the proposed compensation method for AF is conducted not only on the already studied CD Vis spectral region of a Co chiral complex with the use of an AF emulator, but also on the far UV CD spectra of poly‐L‐glutamic acid suspensions with different turbidity levels. Comparison with some correction factors proposed in the literature is presented. Chirality, 2008. © 2008 Wiley‐Liss, Inc.
Discrete Arrays of Liquid‐Crystal‐Supported Proteolipid Monolayers as Phantom Cell Surfaces
Authors: Wise Amber R. , Nye Jeffrey A. , Groves Jay T. 
Published: July 2008

AbstractThe phospholipid bilayers of living cell membranes exist almost universally in a liquid state. This enables motion and spatial reorganization of membrane components on multiple length scales, which is an essential feature of many biological processes. There is great interest in the development of molecularly defined interfaces between synthetic materials and living cells. To this end, there is a need for solid substrate materials that can be derivatized with fluid, membrane‐like interfaces. Herein, we describe array fabrication of discrete liquid‐crystal areas supporting phospholipid monolayer membranes, and characterize the interactions with several different membrane surface proteins [avidin series, cholera toxin, green fluorescent protein (GFP), intercellular adhesion molecule (ICAM) and major histocompatibility complex (MHC)]. Three different linkage strategies (biotin, nickel chelating lipids complexing with histidine, and the choleratoxin binding unit (CTB) associating with GM1 are evaluated. Additionally, experiments with live immunological T cells forming active synapses at the interface exhibit the specific nature of the surface.
Space‐time considerations for hematopoietic stem cell transplantation
Authors: Bhattacharya Deepta , Ehrlich Lauren I. Richie , Weissman Irving L. 
Published: July 2008

AbstractThe mammalian blood system contains a multitude of distinct mature cell lineages adapted to serving diverse functional roles. Mutations that abrogate the development or function of one or more of these lineages can lead to profound adverse consequences, such as immunodeficiency, autoimmunity, or anemia. Replacement of hematopoietic stem cells (HSC) that carry such mutations with HSC from a healthy donor can reverse such disorders, but because the risks associated with the procedure are often more serious than the blood disorders themselves, bone marrow transplantation is generally not used to treat a number of relatively common inherited blood diseases. Aside from a number of other problems, risks associated with cytoreductive treatments that create “space” for donor HSC, and the slow kinetics with which immune competence is restored following transplantation hamper progress. This review will focus on how recent studies using experimental model systems may direct future efforts to implement routine use of HSC transplantation to cure inherited blood disorders.
Cover Picture: Distinct molecular composition of blood and lymphatic vascular endothelial cell junctions establishes specific functional barriers within the peripheral lymph node – Eur. J. Immunol. 8/2008
Authors: Pfeiffer Friederike , Kumar Varsha , Butz Stefan , Vestweber Dietmar , Imhof Beat A. , Stein Jens V. , Engelhardt Britta 
Published: July 2008

AbstractThe cover shows a double immunofluorescence staining of ESAM‐1 and PECAM‐1 in the T cell zone of the peripheral lymph node of the mouse. Red immunofluorescence of ESAM‐1 colocalizes with the bright green immunofluorescence of PECAM‐1, resulting in the observed yellow immunofluorescence. Lymphatic endothelial cells express PECAM‐1 but lack ESAM‐1 and hence are manifested as dim green immunofluorescence. The image was taken from the article by Pfeiffer et al. ( pp.2142–2155) in which the authors demonstrate that molecularly distinct cellular junctions of blood and lymphatic endothelial cells establish different functional barriers controlling the distribution antigens and immune cells in the peripheral lymph node.
Reactions of Halogens/Interhalogens with Polypyridyl Substrates: The Case of 2,4,6‐Tris(2‐pyridyl)‐1,3,5‐triazine
Authors: Aragoni M. Carla , Arca Massimiliano , Devillanova Francesco A. , Hursthouse Michael B. , Huth Susanne L. , Isaia Francesco , Lippolis Vito , Mancini Annalisa , Verani Gaetano 
Published: July 2008

AbstractThe reactions between 2,4,6‐tris(2‐pyridyl)‐1,3,5‐triazine (tptz) and halogens (Br2, I2) or interhalogens (ICl, IBr) yielded different products isolated in the solid state. (Htptz+)(Br3–), (Htptz+)(IBr2–), (H3tptz3+)(I3Br4–)(IBr2–)2, and (H3tptz3+)(ICl2–)3, obtained from the reactions between tptz and Br2, IBr, and ICl, were characterized by single‐crystal X‐ray diffraction and FT‐Raman spectroscopy. All compounds are salts containing the protonated donor counterbalanced by polyhalide anions of various complexity. In particular, in (H3tptz3+)(I3Br4–)(IBr2–)2 the first example of a planar I3Br4– moiety can be observed. In the case of the reaction between tptz and I2, the elemental analysis of the product indicates a 1:1 molar ratio between tptz and I2, but the FT‐Raman spectrum is not consistent with the formation of a simple adduct, clearly indicating the simultaneous presence of diiodine and symmetric triiodide. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Copper‐Catalyzed Asymmetric Allylic Alkylation (Eur. J. Org. Chem. 22/2008)
Authors: Falciola Caroline A. , Alexakis Alexandre 
Published: July 2008

AbstractThe cover picture shows a figurative illustration of the copper‐catalytic cycle for the asymmetric allylic alkylation and its powerful stereoselective control over the regio‐, chemo‐ and enantioselective allylic ring opening of oxiranes or SN2′ displacement of leaving groups. This Microreview by C. A. Falciola and A. Alexakis on p. 3765 ff. covers the field from the early stages of diastereoselective procedures to the more recent highly efficient catalytic protocols.
Antibody development to testosterone and its application in capillary electrophoresis‐based immunoassay
Authors: Chen Hong‐Xu , Zhang Xin‐Xiang 
Published: July 2008

AbstractThe present report describes a rapid, simple, and highly selective approach to perform testosterone competitive immunoassay by CE and LIF detection. The method involves using synthesized fluorescence‐labeled testosterone as a tracer to compete with testosterone. Two polyclonal antibodies (antibody (Ab) arised from T‐3‐BSA (Ab3) and Ab arised from T‐17‐BSA (Ab17)) and their respective tracers have been optimized and Ab3 system is used for the quantification of testosterone by CE‐based immunoassay. The method is developed with a wide working range of 3.70–2000 ng/mL and an LOD at 1.11 ng/mL. Tests for normal and positive urine samples show that this method has the potential to be applied in testosterone doping control.
Drug–liposome distribution phenomena studied by capillary electrophoresis‐frontal analysis
Authors: Østergaard Jesper , Jorgensen Lene , Engelbrecht Thomsen Anne , Weng Larsen Susan , Larsen Claus , Jensen Henrik 
Published: July 2008

AbstractThe potential of using CE frontal analysis (CE‐FA) for the study of low‐molecular‐weight drug–liposome interactions was assessed. The interaction of bupivacaine, brompheniramine, chlorpromazine, imipramine, and ropivacaine with net negatively charged 80/20 mol% 1‐oleoyl‐2‐palmitoyl‐sn‐glycero‐3‐phosphocholine/egg yolk phosphatidic acid liposome suspensions in HEPES buffer at pH 7.4 was investigated. The fraction of free drug as a function of lipid concentration was measured and apparent liposome – buffer distribution coefficients were determined for the basic drug substances. The distribution coefficients increased in the order ropivacaine, bupivacaine, brompheniramine, imipramine, and chlorpromazine. The developed CE method was relatively fast allowing estimates of drug–liposome affinity to be obtained within 15 min. CE‐FA may have the potential to become a valuable tool for the characterization of drug–liposome interactions in relation to estimation of drug lipophilicity and for the evaluation of drug distribution in liposomal drug delivery systems.
Development of a temperature gradient focusing method for in situ extraterrestrial biomarker analysis
Authors: Danger Grégoire , Ross David 
Published: July 2008

AbstractScanning temperature gradient focusing (TGF) is a recently described technique for the simultaneous concentration and separation of charged analytes. It allows for high analyte peak capacities and low LODs in microcolumn electrophoretic separations. In this paper, we present the application of scanning TGF for chiral separations of amino acids. Using a mixture of seven carboxyfluorescein succinimidyl ester‐labeled amino acids (including five chiral amino acids) which constitute the Mars7 standard, we show that scanning TGF is a very simple and efficient method for chiral separations. The modulation of TGF separation parameters (temperature window, pressure scan rate, temperature range, and chiral selector concentration) allows optimization of peak efficiencies and analyte resolutions. The use of hydroxypropyl‐β‐CD at low concentration (1–5 mmol/L) as a chiral selector, with an appropriate pressure scan rate ( −0.25 Pa/s) and with a low temperature range (3–25°C over 1 cm) provided high resolution between enantiomers (Rs >1.5 for each pair of enantiomers) using a short, 4 cm long capillary. With these new results, the scanning TGF method appears to be a viable method for in situ trace biomarker analysis for future missions to Mars or other solar system bodies.
A chip‐based immunoaffinity capillary electrophoresis assay for assessing hormones in human biological fluids
Authors: Wellner Edward F. , Kalish Heather 
Published: July 2008

AbstractA chip‐based capillary electrophoresis system has been designed for assessing the concentrations of four hormones in whole human blood, saliva, and urine. The desired analytes were isolated by immunoextraction using a panel of four analyte‐specific antibodies immobilized onto a glass fiber insert within the injection port of the chip. Following extraction, the captured analytes were labeled prior to electro‐elution into the chip separation channel, where they were resolved into four individual peaks in circa 2 min. Quantification of each peak was achieved by on‐line LIF detection and integration of the area under each peak. Comparison to commercial high‐sensitivity immunoassays demonstrated that the chip‐based assay provided fast, accurate, and precise measurements for the analytes under investigation. As the availability of commercially available antibodies rapidly expands, the application of this system will greatly increase. Chip‐based CE separations of multiple analytes from a single sample also provide a significant advantage in the analysis of small samples.
Microchip‐based multiplex electro‐immunosensing system for the detection of cancer biomarkers
Authors: Ko Yong‐Jun , Maeng Joon‐Ho , Ahn Yoomin , Hwang Seung Yong , Cho Nahm‐Gyoo , Lee Seoung‐Hwan 
Published: July 2008

AbstractMicrofluidic‐based microchips have become the focus of research interest for immunoassays and biomarker diagnostics. This is due to their aptitude for high‐throughput processing, small sample volume, and short analysis times. In this paper, we describe the development of a microchip‐based multiplex electro‐immunosensing system for simultaneous detection of cancer biomarkers using gold nanoparticles and silver enhancer. Our microchip is composed of biocompatible poly(PDMS) and glass substrates. To fix the antibody‐immobilized microbeads, we used pillar‐type microfilters within a reaction chamber. An immunogold silver staining (IGSS) method was used to amplify the electrical signal that corresponded to the immunecomplex. To demonstrate this approach, we simultaneously assayed three cancer biomarkers, alpha‐fetoprotein (AFP), carcinoembryonic antigen (CEA), and prostate‐specific antigen (PSA) on the microchip. The electrical signal generated from the result of the immunoreaction was measured and monitored by a PC‐based system. The overall assay time was reduced from 3–8 h to about 55 min when compared to conventional immunoassays. The working range of the proposed microchip was from 10−3 to 10−1 μg/mL of the target antigen.
Simultaneous removal of SO2 and NO by highly reactive absorbent containing calcium hypochlorite
Authors: Zhao Yi , Xu Peiyao , Wang Lidong 
Published: July 2008

AbstractFly ash, industrial lime, and an additive [calcium hypochlorite (C)] were used to prepare a highly reactive absorbent. Simultaneous desulfurization and denitrification were carried out in a flue gas circulating fluidized bed (CFB). The effects of influencing factors on the removal efficiencies of SO2 and NO were also investigated. Removal efficiencies of 94.5% for SO2 and 65.5% for NO were obtained under the optimal experimental conditions. The component of the spent absorbent was analyzed with chemical analysis methods. The results indicated that more nitrogen than sulfur species appeared in the spent absorbent. A scanning electron microscope (SEM) and an accessory X‐ray energy spectrometer (EDS) were used to observe the microproperties of the samples, including fly ash, highly reactive absorbent, and spent absorbent. The removal products of spent absorbent were analyzed using ion chromatography and chemical analysis. The simultaneous removal mechanism of SO2 and NO based on this absorbent was proposed according to the experimental results. © 2008 American Institute of Chemical Engineers Environ Prog, 2008
A particle swarm optimization approach for hexahedral mesh smoothing
Authors: Yilmaz A. Egemen , Kuzuoglu Mustafa 
Published: July 2008

AbstractThere are some approaches for all‐hexahedral mesh quality improvement by means of node‐movement while preserving the connectivity. Among these methods, the most easily implemented and well known one is the Laplacian smoothing method; however, for this method mesh quality improvement is not guaranteed in all cases, and this approach might cause inverted elements especially in concave regions. In this work, a method for the improvement of hexahedral mesh shape‐quality without causing inverted elements is proposed; which is based on optimization of an objective function calculated by means of the individual qualities of hexahedral elements in the mesh. The shape‐quality for each hexahedral element is defined via the condition number of the relevant element. The numerical optimization scheme is the particle swarm optimization method, which originated from observations related to the social behaviors of bird, insect, or fish colonies. The purpose of this paper is to discuss the applicability of this approach to mesh smoothing. Some examples are given in order to demonstrate the applicability. Copyright © 2008 John Wiley & Sons, Ltd.
Study of Internal and External Leaks in Tests of Anode‐Supported SOFCs
Authors: Rasmussen J. F. B. , Hendriksen P. V. , Hagen A. 
Published: July 2008

AbstractA planar anode‐supported solid oxide fuel cell (SOFC) has been tested to investigate gas tightness of the electrolyte and the applied seals. Gas leaks reduce the efficiency of the SOFC and it is thus important to determine and minimise them. Probe gases (He and Ar) and a Quadrupole Mass Spectrometer were used to detect both internal (through electrolyte) and external (through seals) gas leaks. The internal gas leak through the electrolyte was quantified under different conditions, as was the external leak from the surroundings to the anode. The internal gas leak did not depend on the pressure difference between the anode and the cathode gas compartment, and can thus be described as diffusion driven. External leaks between the surroundings and the anode, but not the cathode gas compartment was observed. They were influenced by the pressure difference and are thus driven by both concentration and pressure gradients. The measured gas leaks deduced from the probe gas experiments and the total leak calculated from the deviation between the Emf defined by the gases and the cell OCV (which contains all gas leaks as well as effects of electronic leaks) were compared. Good agreement between the two measures was observed.
Barium Non‐Stoichiometry Role on the Properties of Ba1+xCe0.65Zr0.20Y0.15O3–δ Proton Conductors for IT‐SOFCs
Authors: Barison S. , Battagliarin M. , Cavallin T. , Daolio S. , Doubova L. , Fabrizio M. , Mortalò C. , Boldrini S. , Gerbasi R. 
Published: July 2008

AbstractProton conducting perovskite oxides have been widely investigated because of their potential as electrolytes for intermediate temperature solid oxide fuel cells. Among them, BaCeO3‐ based materials exhibit good proton conductivity under a humidified hydrogen‐containing atmosphere, but rather poor chemical stability in CO2 atmosphere. The substitution with Zr for Ce improves the chemical stability but reduces proton conductivity due to difficulties in fabricating dense materials. In the present work, single phase nanostructured powders of Ba1+xCe0.65Zr0.20Y0.15O3–δ (x = 0, 0.05, 0.10) solid solutions have been prepared by a modified sol–gel Pechini method with the final aim of evaluating the role of barium on their chemical and electrical properties. A significant influence of barium excess on the preparation and on properties of these materials has been demonstrated. In fact, density measurements evidenced that a 5 or 10 mol% nominal barium excess sensibly favoured the sintering process. Impedance analyses of sintered pellets confirmed the necessity of barium excess in order to avoid the lowering of proton conductivity, which has been evidenced for samples having stoichiometric barium content. Moreover, an unforeseen increase in chemical stability in CO2‐containing atmosphere with the growth of the barium excess was detected by thermogravimetric analyses.
A predictive depression pattern in mild cognitive impairment
Authors: Houde Michèle , Bergman Howard , Whitehead Victor , Chertkow Howard 
Published: July 2008

AbstractObjectiveTo evaluate the prognostic utility of the presence, persistence, and patterns of depression in subjects with amnestic Mild Cognitive Impairment (MCI).MethodSixty amnestic MCI patients were assessed cognitively and for presence of depression using the 30 item Geriatric Depression Scale (GDS). They were followed annually for an average period of 4.3 years.ResultsSimple presence or absence of depression at referral did not predict progression of MCI to AD. Positive answers to specific GDS questions referring to “melancholic” affect as well as the persistence of depression over two to three years significantly predicted cognitive deterioration leading to AD.ConclusionThe affective characteristics of depression at referral and the persistence of depression were better predictors of conversion to AD than the simple presence or absence of depression measured at referral time. Copyright © 2008 John Wiley & Sons, Ltd.