bluuebunny/crossref_metadata_2025_split huggingface dataset:
Palladium(II)‐Phosphine Complexes Supported on Magnetic Nanoparticles: Filtration‐Free, Recyclable Catalysts for Suzuki–Miyaura Cross‐Coupling Reactions
Authors: Shylesh Sankaranarayanapillai , Wang Lei , Thiel Werner R. 
Published: February 2010

AbstractAn organic‐inorganic hybrid heterogeneous nanocatalyst system was synthesized by covalent grafting a palladium dichloride complex of the type (L)2PdCl2 (L=trimethoxysilyl‐functionalized triphenylphosphine) on silica‐coated magnetic nanoparticles. It is a highly active and recyclable catalyst for the Suzuki–Miyaura cross‐coupling reaction. The new catalyst can easily be separated from the reaction mixture by applying an external magnetic field and can be recycled many times without any loss of activity.
Highly Efficient One‐Pot Synthesis of 2‐Substituted Quinazolines and 4H‐Benzo[d][1,3]oxazines via Cross Dehydrogenative Coupling using Sodium Hypochlorite
Authors: Maheswari C. Uma , Kumar G. Sathish , Venkateshwar M. , Kumar R. Arun , Kantam M. Lakshmi , Reddy K. Rajender 
Published: February 2010

AbstractThis communication describes a catalyst‐free synthesis of 2‐substituted quinazolines and 4H‐benzo[d][1,3]oxazines using commericially available sodium hypochlorite as oxidant. Operational simplicity, mild reaction conditions and the ability to construct structurally diverse 2‐quinazolines and 2‐substituted 4H‐benzo[d][1,3]oxazines by this method render it to be a practical alternative for the synthesis of these heterocycles.
Rhodium‐ and Palladium‐Catalyzed Hydroarylation of Propargylic Amines with Arylboronic Acids
Authors: Arcadi Antonio , Aschi Massimiliano , Chiarini Marco , Ferrara Giovanni , Marinelli Fabio 
Published: February 2010

AbstractThe hydroarylation of 3‐arylprop‐2‐yn‐1‐amine derivatives with arylboronic acids has been studied in the presence of rhodium or palladium catalysts. By using a rhodium‐based catalytic system, β,γ‐diarylallylamines were isolated in good yields. By contrast, the formation of the regiosomeric γ,γ‐diarylallylamines was achieved by means of a palladium catalyst in the presence of acetic acid. The complementary regioselectivity displayed by these two processes is a consequence of different catalytic cycles, involving respectively carborhodation or hydropalladation of the coordinated alkyne as key steps. Calculated charge distributions in the π‐complexes are in accord with the results obtained.
The First General and Selective Palladium(II)‐Catalyzed Alkoxycarbonylation of Arylboronates: Interplay among Benzoquinone‐Ligated Palladium(0) Complex, Organoboron, and Alcohol Solvent
Authors: Yamamoto Yoshihiko 
Published: February 2010

AbstractMethoxycarbonylation of aryl‐ and alkenylboron compounds was performed using the palladium(II) acetate/triphenylphosphine [Pd(OAc)2/PPh3] catalyst with p‐benzoquinone as a stoichiometric oxidant in methanol at ambient temperature to obtain the corresponding methyl esters in good yields. A wide variety of functional groups including various carbonyl functionalities, nitrile, nitro, sulfone, and unprotected pyrrole rings were tolerated in the methoxycarbonlation, while the use of higher alcohols except for tert‐butanol afforded various p‐chlorobenzoates in moderate to high yields. The catalytic alkoxycarbonylation proceeded without any acid or base additive, and an oxidative transmetalation step is proposed to explain the exceptional efficacy of this protocol. DFT and MP2 calculations support the proposed mechanism.
Analysis of 2‐propanol in exhaled breath using in situ enrichment and cataluminescence detection
Authors: Wu Yayan , Wen Fang , Liu Da , Kong Hao , Zhang Chenhua , Zhang Sichun 
Published: February 2010

AbstractWe report a simple gaseous sensor for the sensitive detection of trace 2‐propanol in exhaled breath using in situ enrichment and cataluminescence detection method on the surface of nanomaterials. The influences of heating voltage and absorption time on the CTL intensity were discussed, respectively. In the selected conditions, the linear range of 2‐propanol concentration is 60–600 ppbv and the detection of limit is 11 ppbv. Moreover, the lifetime and selectivity of the sensor were also investigated. It has the potential to diagnostic volatile organic compounds in human breath. Copyright © 2010 John Wiley & Sons, Ltd
Dynamic gene expression regulation model for growth and penicillin production in Penicillium chrysogenum
Authors: Douma Rutger D. , Verheijen Peter J.T. , de Laat Wim T.A.M. , Heijnen Joseph J. , van Gulik Walter M. 
Published: February 2010

AbstractAs is often the case for microbial product formation, the penicillin production rate of Penicillium chrysogenum has been observed to be a function of the growth rate of the organism. The relation between the biomass specific rate of penicillin formation (qp) and growth rate (µ) has been measured under steady state conditions in carbon limited chemostats resulting in a steady state qp(µ) relation. Direct application of such a relation to predict the rate of product formation during dynamic conditions, as they occur, for example, in fed‐batch experiments, leads to errors in the prediction, because qp is not an instantaneous function of the growth rate but rather lags behind because of adaptational and regulatory processes. In this paper a dynamic gene regulation model is presented, in which the specific rate of penicillin production is assumed to be a linear function of the amount of a rate‐limiting enzyme in the penicillin production pathway. Enzyme activity assays were performed and strongly indicated that isopenicillin‐N synthase (IPNS) was the main rate‐limiting enzyme for penicillin‐G biosynthesis in our strain. The developed gene regulation model predicts the expression of this rate limiting enzyme based on glucose repression, fast decay of the mRNA encoding for the enzyme as well as the decay of the enzyme itself. The gene regulation model was combined with a stoichiometric model and appeared to accurately describe the biomass and penicillin concentrations for both chemostat steady‐state as well as the dynamics during chemostat start‐up and fed‐batch cultivation. Biotechnol. Bioeng. 2010;106: 608–618. © 2010 Wiley Periodicals, Inc.
Collapse temperature of solutions important for lyopreservation of living cells at ambient temperature
Authors: Yang Geer , Gilstrap Kyle , Zhang Aili , Xu Lisa X. , He Xiaoming 
Published: February 2010

AbstractIn this study, the collapse temperature was determined using the freeze‐drying microscopy (FDM) method for a variety of cell culture medium‐based solutions (with 0.05–0.8 M trehalose) that are important for long‐term stabilization of living cells in the dry state at ambient temperature (lyopreservation) by freeze‐drying. Being consistent with what has been reported in the literature, the collapse temperature of binary water‐trehalose solutions was found to be similar to the glass transition temperature (T′g ∼ −30°C) of the maximally freeze‐concentrated trehalose solution (∼80 wt% trehalose) during the freezing step of freeze‐drying, regardless of the initial concentration of trehalose. However, the effect of the initial trehalose concentration on the collapse temperature of the cell culture medium‐based trehalose solutions was identified to be much more significant, particularly when the trehalose concentration is less than 0.2 M (the collapse temperature can be as low as −65°C). We also determined that cell density from 1 to 10 million cells/mL and ice seeding at high subzero temperatures (−4 and −7°C) have negligible impact on the solution collapse temperature. However, ice seeding does significantly affect the ice crystal morphology formed during the freezing step and therefore the drying rate. Finally, bulking agents (mannitol) could significantly affect the collapse temperature only when trehalose concentration is low (<0.2 M). However, improving the collapse temperature by using a high concentration of trehalose might be preferred to the addition of bulking agents in the solutions for freeze‐drying of living cells. We further confirmed the applicability of the collapse temperature measured with small‐scale (2 µL) samples using the FDM system to freeze‐drying of large‐scale (1 mL) samples using scanning electron microscopy (SEM) data. Taken together, the results reported in this study should provide useful guidance to the development of optimal freeze‐drying protocols for lyopreservation of living cells at ambient temperature for easy maintenance and convenient wide distribution to end users, which is important to the eventual success of modern cell‐based medicine. Biotechnol. Bioeng. 2010;106: 247–259. © 2010 Wiley Periodicals, Inc.
Evolutionary optimization of peptide substrates for proteases that exhibit rapid hydrolysis kinetics
Authors: Boulware Kevin T. , Jabaiah Abeer , Daugherty Patrick S. 
Published: February 2010

AbstractProtease cleavage site recognition motifs can be identified using protease substrate discovery methodologies, but typically exhibit non‐optimal specificity and activity. To enable evolutionary optimization of substrate cleavage kinetics, a two‐color cellular library of peptide substrates (CLiPS) methodology was developed. Two‐color CLiPS was applied to identify peptide substrates for the tobacco etch virus (TEV) protease from a random pentapeptide library, which were then optimized by screening of a focused, extended substrate library. Quantitative library screening yielded seven amino acid substrates exhibiting rapid hydrolysis by TEV protease and high sequence similarity to the native seven‐amino‐acid substrate, with a strong consensus of EXLYΦQG. Comparison of hydrolysis rates for a family of closely related substrates indicates that the native seven‐residue TEV substrate co‐evolved with TEV protease to facilitate highly efficient hydrolysis. Consensus motifs revealed by screening enabled database identification of a family of related, putative viral protease substrates. More generally, our results suggest that substrate evolution using CLiPS may be useful for optimizing substrate selectivity and activity to enable the design of more effective protease activity probes, molecular imaging agents, and prodrugs. Biotechnol. Bioeng. 2010; 106: 339–346. © 2010 Wiley Periodicals, Inc.
Health-related quality of life after minimally invasive oesophagectomy
Authors: Parameswaran R , Blazeby J M , Hughes R , Mitchell K , Berrisford R G , Wajed S A 
Published: February 2010

Abstract

Background
Open oesophagectomy has a detrimental impact on health-related quality of life (HRQL), with recovery taking up to a year. Minimally invasive oesophagectomy (MIO) may enable a more rapid recovery of HRQL.

Methods
Clinical outcomes from consecutive patients undergoing MIO for cancer were recorded between April 2005 and April 2007. Patients completed validated questionnaires, European Organization for Research and Treatment of Cancer QLQ-C30 and QLQ-OES18, before surgery and at 6 weeks, 3, 6 and 12 months after surgery.

Results
MIO for cancer or high-grade dysplasia was planned in 62 patients, but abandoned in four owing to occult metastatic disease. Resection was completed in the remaining 58, two having partial conversion to open surgery. There was one in-hospital death and 29 patients developed complications. At 1 year, 52 of 58 patients were alive. Questionnaire response rates were high at each time point (overall compliance 84 per cent). Six weeks after MIO, patients reported deterioration in functional aspects of HRQL and more symptoms than at baseline. However, most improved by 3 months and had returned to baseline levels by 6 months. These levels were maintained 1 year after surgery, with 85 per cent of patients recovering in more than 50 per cent of the HRQL domains.

Conclusion
MIO leads to a rapid restoration of HRQL.
Development and validation of a robust LC‐MS‐MS with atmospheric pressure chemical ionization for quantitation of carbazochrome sodium sulfonate in human plasma: application to a pharmacokinetic study
Authors: Song Min , Zhao Hua , Wang Li , Yang Lin , Hang Taijun , Wen Aidong 
Published: February 2010

AbstractA highly selective and sensitive liquid chromatography coupled with atmospheric pressure chemical ionization tandem mass spectrometry (LC‐APCI‐MS‐MS) was developed and validated for the quantitation and pharmacokinetic study of carbazochrome sodium sulfonate in human plasma. Protein precipitation with 14% perchloric acid solution was selected for sample preparation, and amiloride hydrochloride was employed as an internal standard. The analytes were separated on a Hypersil ODS‐2 column by a multiple‐step linear gradient elution with a mobile phase consisting of 0.2% formic acid solution and methanol pumped at a flow rate of 1.0 mL/min. The determination was optimized and carried out with positive atmospheric pressure chemical ionization by selective reaction monitoring of the ion of m/z 148, the protonated thermodegraded fragment of the free acidic form of carbazochrome sodium sulfonate selected as the parent, and the ion of m/z 107 as the optimum collision induced dissociation (CID) product. The method was fully validated over a concentration range of 0.5–50 ng/mL, with the lower limit of quantitation of 0.5 ng/mL. The application of the LC‐MS‐MS method was demonstrated for the specific and quantitative analysis of carbazochrome sodium sulfonate in human plasma from a pharmacokinetic study in 24 healthy male Chinese volunteers after a single oral administration of 90 mg carbazochrome sodium sulfonate capsules. Copyright © 2010 John Wiley & Sons, Ltd.
Redesigning the Active Site of Transaldolase TalB from Escherichia coli: New Variants with Improved Affinity towards Nonphosphorylated Substrates
Authors: Schneider Sarah , Gutiérrez Mariana , Sandalova Tatyana , Schneider Gunter , Clapés Pere , Sprenger Georg A. , Samland Anne K. 
Published: February 2010

AbstractRecently, we reported on a transaldolase B variant (TalB F178Y) that is able to use dihydroxyacetone (DHA) as donor in aldol reactions. In a second round of protein engineering, we aimed at improving the affinity of this variant towards nonphosphorylated acceptor aldehydes, that is, glyceraldehyde (GA). The anion binding site was identified in the X‐ray structure of TalB F178Y where a sulfate ion from the buffer was bound in the active site. Therefore, we performed site‐directed saturation mutagenesis at three residues forming the putative phosphate binding site, Arg181, Ser226 and Arg228. The focused libraries were screened for the formation of D‐fructose from DHA and d,l‐GA by using an adjusted colour assay. The best results with respect to the synthesis of D‐fructose were achieved with the TalB F178Y/R181E variant, which exhibited an at least fivefold increase in affinity towards d,l‐GA (KM=24 mM). We demonstrated that this double mutant can use D‐GA, glycolaldehyde and the L‐isomer, L‐GA, as acceptor substrates. This resulted in preparative synthesis of D‐fructose, D‐xylulose and L‐sorbose when DHA was used as donor. Hence, we engineered a DHA‐dependent aldolase that can synthesise the formation of polyhydroxylated compounds from simple and cheap substrates at preparative scale.
Size‐Tunable Highly Luminescent SiO2 Particles Impregnated with Number‐Adjusted CdTe Nanocrystals
Authors: Yang Ping , Murase Norio 
Published: February 2010

AbstractHighly luminescent SiO2 particles impregnated with CdTe nanocrystals (NCs) are prepared by a sol–gel procedure. Partial ligand exchange from thioglycolic acid to 3‐mercaptopropyltrimethoxysilane (MPS) on the NCs enables retention of the initial photoluminescence (PL) efficiency of the NCs in water, while the simultaneous addition of a poor solvent (ethanol) results in regulated assembly of the NCs through condensation of hydrolyzed MPS. The SiO2 particles thus prepared have, for example, a diameter of 16 nm and contain three NCs each. The PL efficiency of these particles is 40 %, while the initial efficiency is 46 % in a colloidal solution. The redshift and narrowed spectral width in PL observed after impregnation indicate that the concentration of NCs in these nearly reaches the ultimate value (on the order of 1021 particles per liter). The porosity of these particles is investigated by means of N2 adsorption–desorption isotherms. Due to the SiO2 shell, these particles have higher stability in phosphate‐buffered saline buffer solution than the initial NCs. Their potential use for labeling in bio‐applications is investigated by conjugating biotinylated immunoglobulin G to them by using streptavidin maleimide as linker. Successful conjugation is confirmed by electrophoresis in agarose gel. This preparation method is an important step towards fabricating intensely emitting biocompatible SiO2 particles impregnated with semiconductor NCs.
Influence of photonic excitations on the electrical parameters of TlInS2 crystals
Authors: Qasrawi A. F. , Gasanly N. M. 
Published: February 2010

AbstractThe photo‐excitation effect on the current transport mechanism in TlInS2 crystals has been studied by means of dark and illuminated conductivity measurements. The temperature‐dependent electrical conductivity analysis in the temperature region of 110‐340 K revealed the domination of the thermionic emission and the thermally assisted variable range hopping (VRH) of charge carriers above and below 160 K, respectively. Above 160 K, the conductivity activation energies in the dark are found to be 0.28 and 0.15 eV in the temperature regions of 340‐240 K and 230‐160 K, respectively. In the temperature region of 110‐150 K, the dark variable range hopping analysis revealed a density of localized states of 1.99×1022 cm–3eV–1, an average hopping distance of 0.53 nm and an average hopping energy of 79.65 meV. When the sample was photo‐excited, the values of the conductivity activation energies, the density of localized states near the Fermi level and the average hopping energy were observed to decrease sharply with increasing illumination intensity. On the other hand, the average hopping distance increased with rising illumination intensity. Such behaviours were attributed to the Fermi level shift and/or trap density reduction by electron‐hole recombination. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Fabrication and optical properties of two‐dimensional photonic crystal of ZnO pillars
Authors: Wu Wei , Yu Ke , Mao Huibing , Zhang Zhengli , Zhu Ziqiang 
Published: February 2010

AbstractTwo‐dimensional (2D) photonic crystal of ZnO pillars was synthesized on silicon substrate by the combination of template method and vapor‐phase transport method. The microstructure and morphology of the ZnO photonic crystal was evaluated by using scanning electron microscope (SEM) and X‐ray diffraction (XRD). Large‐area specular reflectance measurements showed the presence of photonic stop band. The effect of the photonic band gap and the special structure on the photoluminescence (PL) properties of ZnO photonic crystal has been investigated. Both suppression and enhancement in the PL were observed. Raman scattering analyses demonstrated that the defect of ZnO photonic crystal exists in this experiment. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Some structural considerations on the perovskite‐type A1‐ySryCo1‐xFexO3‐δ solid solution series
Authors: Magnone E. , Miyayama M. , Traversa E. 
Published: February 2010

AbstractSolid solution series of La1‐ySryCo1‐xFexO3‐δ were extensively studied in the past as cathode materials for solid oxide fuel cells. However, the crystal structure behavior of La1‐ySryCo1‐xFexO3‐δ solid solution series when La‐ions are replaced with another rare‐earth ion or metallic alkaline earth metal is at present not fully understood. Here we report X‐ray powder diffraction measurements performed on samples of the Sm0.8Sr0.2Co1‐xFexO3‐δ solid solution series. This study demonstrates that the average A‐cation radius, as well as the Fe content (x), affects the structural modification of the A1‐ySryCo1‐xFexO3+δ solid solution series significantly. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Silicon transport under rotating and combined magnetic fields in liquid phase diffusion growth of SiGe
Authors: Armour N. , Dost S. 
Published: February 2010

AbstractThe effect of applied rotating and combined (rotating and static) magnetic fields on silicon transport during the liquid phase diffusion growth of SiGe was experimentally studied. 72‐hour growth periods produced some single crystal sections. Single and polycrystalline sections of the processed samples were examined for silicon composition. Results show that the application of a rotating magnetic field enhances silicon transport in the melt. It also has a slight positive effect on flattening the initial growth interface. For comparison, growth experiments were also conducted under combined (rotating and static) magnetic fields. The processed samples revealed that the addition of static field altered the thermal characteristics of the system significantly and led to a complete melt back of the germanium seed. Silicon transport in the melt was also enhanced under combined fields compared with experiments with no magnetic field. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Auslegungsfragen zur Energieeinsparverordnung. Fachkommission Bautechnik der Bauministerkonferenz. Teil 11
Authors: Achelis Justus 
Published: February 2010

AbstractDie Bundesregierung hat auf Grund des § 1 Abs. 2, des § 2 Abs. 2 und 3, des § 3 Abs. 2, des § 4, jeweils in Verbindung mit § 5, sowie des § 5a Satz 1 und 2 des Energieeinsparungsgesetzes die “Verordnung zur Änderung der Energieeinsparverordnung” vom 29. April 2009 erlassen (BGBl. I 2009, S. 954 ff.).Die geänderte Energieeinsparverordnung (“EnEV 2009”) ist am 01.10.2009 in Kraft getreten.Um im Vollzug eine möglichst einheitliche Anwendung der Energieeinsparverordnung zu ermöglichen, hat die Fachkommission “Bautechnik” der Bauministerkonferenz beschlossen, eine Arbeitsgruppe einzurichten, die die in den Ländern eingehenden Anfragen von allgemeinem Interesse beantworten soll.Die Entwürfe der Arbeitsgruppe werden dann in den Sitzungen der Fachkommission beraten.Die Arbeitsgruppe wurde unter Beteiligung von Vertretern des Bundesministeriums für Verkehr, Bau und Stadtentwicklung, der Obersten Bauaufsichtsbehörden der Länder Bayern, Baden‐Württemberg, Brandenburg und Nordrhein‐Westfalen sowie des DIBt eingerichtet.Die nachfolgend abgedruckten Anfragen und deren Antworten sind am 09.12.2009 in der wiedergegebenen Form beschlossen worden.
Anforderungen des Gesundheitsschutzes an Bauprodukte im Zulassungsverfahren am Beispiel der Bodenbeläge
Authors: Kirchner Doris , Dommaschk N. , Eichler A. , Tykiel V. , Kraeft C. , Misch W. 
Published: February 2010

AbstractSeit 2004 erteilt das DIBt Zulassungen für Bodenbeläge zur Verwendung in Aufenthaltsräumen. Waren zunächst die Zulassungen direkt mit der Anforderung an die Schwerentflammbarkeit gekoppelt, so werden nun durch die fortschreitende Einführung harmonisierter Produktnormen immer mehr Zulassungen erteilt, die allein den Gesundheitsschutz regeln. Ein Novum am DIBt, denn bislang wurde der Umwelt‐ und Gesundheitsschutz zwar in vielen Zulassungsbereichen für Bauprodukte mitberücksichtigt, er war aber nie allein für die Zulassungspflicht maßgeblich.Über diesen innovativen Zulassungsbereich, seine Entwicklung und zukünftige Herausforderungen soll im Folgenden ausführlich informiert werden.