bluuebunny/crossref_metadata_2025_split huggingface dataset:
Determination of chlorfenapyr in leek grown under greenhouse conditions with GC‐μECD and confirmation by mass spectrometry
Authors: Rahman Md. Musfiqur , Choi Jeong‐Heui , Abd El‐Aty A. M. , Park Jong Hyouk , Park Ji‐Yeon , Im Geon‐Jae , Shim Jae‐Han 
Published: May 2011

ABSTRACTA simple analytical method was developed for the determination of chlorfenapyr residues in leeks grown under greenhouse conditions. Residues were extracted by salting out, analyzed by gas chromatography with microelectron‐capture detection, and confirmed via gas chromatography–mass spectrometry. The calibration curves were found to be linear with correlation coefficients (r2) in excess of 0.998. The limits of detection and quantification were 0.0015 and 0.005 mg kg−1, respectively. For validation purposes, recovery studies were carried out at low and high levels. Yield recovery rates were 87.27–89.64% with a relative standard deviation <6%. A maximum of 0.32 mg kg−1 of chlorfenapyr residue was detected in leek sample sprayed three times at 7 day intervals until 7 days prior to harvest. The results of this study suggest that chlorfenapyr is acceptable for application in/on leeks under the recommended dosage regimen. Copyright © 2011 John Wiley & Sons, Ltd.
Techno‐economic evaluation of an inclusion body solubilization and recombinant protein refolding process
Authors: Freydell Esteban J. , van der Wielen Luuk A. M. , Eppink Michel H.M. , Ottens Marcel 
Published: May 2011

AbstractExpression of recombinant proteins in Escherichia coli is normally accompanied by the formation of inclusion bodies (IBs). To obtain the protein product in an active (native) soluble form, the IBs must be first solubilized, and thereafter, the soluble, often denatured and reduced protein must be refolded. Several technically feasible alternatives to conduct IBs solubilization and on‐column refolding have been proposed in recent years. However, rarely these on‐column refolding alternatives have been evaluated from an economical point of view, questioning the feasibility of their implementation at a preparative scale. The presented study assesses the economic performance of four distinct process alternatives that include pH induced IBs solubilization and protein refolding (pH_IndSR); IBs solubilization using urea, dithiothreitol (DTT), and alkaline pH followed by batch size‐exclusion protein refolding; inclusion bodies (IBs) solubilization using urea, DTT, and alkaline pH followed by simulated moving bed (SMB) size‐exclusion protein refolding, and IBs solubilization using urea, DTT and alkaline pH followed by batch dilution protein refolding. The economic performance was judged on the basis of the direct fixed capital, and the production cost per unit of product (PC). This work shows that (1) pH_IndSR system is a relatively economical process, because of the low IBs solubilization cost; (2) substituting β‐mercaptoethanol for dithiothreithol is an attractive alternative, as it significantly decreases the product cost contribution from the IBs solubilization; and (3) protein refolding by size‐exclusion chromatography becomes economically attractive by changing the mode of operation of the chromatographic reactor from batch to continuous using SMB technology. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Extracellular purine and pyrimidine catabolism in cell culture
Authors: Carvalhal Ana V. , Santos Sónia Sá , Carrondo Manuel J. T. 
Published: May 2011

AbstractThe presence of purines and pyrimidines bases, nucleosides, and nucleotides in the culture medium has shown to differently affect the growth of a Chinese hamster ovary (CHO) cell line producing the secreted form of the human placental alkaline phosphatase enzyme (SEAP; Carvalhal et al., Biotech Prog. 2003;19:69‐83). CHO, BHK, as well as Sf9 cell growth was clearly reduced in the presence of purines but was not affected by pyrimidines at the concentrations tested. The knowledge about the mechanisms by which nucleotides exert their effect when present outside the cells remains very incomplete. The catabolism of both extracellular purines and pyrimidines was followed during the culture of CHO cells. Purines/pyrimidines nucleotides added at a concentration of 1 mM to the culture medium decreased to negligible concentrations in the first 2 days. Purine and pyrimidine catabolism originated only purinic and pyrimidic end‐products, respectively. The comparison between AMP catabolism in serum‐free cultures (CHO cells expressing Factor VII and Sf9 cells) and in cultures containing serum (CHO cells expressing SEAP and BHK cells expressing Factor VII) showed that AMP extracellular catabolism is mediated by both cells and enzymes present in the serum. This work shows that the quantification of purines and pyrimidines in the culture medium is essential in animal cell culture optimization. When using AMP addition as a chemical cell growth strategy for recombinant protein production improvement, AMP extracellular concentration monitoring allows the optimization of the multiple AMP addition strategy for a prolonged cell culture duration with high specific productivity. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Synthesis, Characterization, and Photoactivity of Ta2O5‐Grafted SiO2 Nanoparticles
Authors: Ndiege Nicholas , Chandrasekharan Ramesh , Radadia Adarsh D. , Harris William , Mintz Eric , Masel Richard I. , Shannon Mark A. 
Published: May 2011

AbstractHerein, we discuss the synthesis as well as material and photochemical characterization of nanometer‐sized Ta2O5 decorated, in a controlled fashion, on top of 20 nm diameter SiO2 particles to yield a composite oxide with a tunable band‐gap width. Particular emphasis is paid to control of particle size, and control of the distribution of the overlying oxide. The nanoscale dimension imparts a high surface area and introduces quantum confinement effects that displace the conduction band more negatively and the valence band more positively on the electrochemical scale of potentials. This band shift results in an increase of the number of possible participants in photocatalytic reactions. The band shift is shown to result in an increase in driving force for thermodynamically feasible reactions. By decorating SiO2 with smaller‐sized Ta2O5, the interplay of the Lewis acidity of SiO2 and the contact area between Ta2O5 and SiO2 is utilized to develop a photocatalyst with higher photoactivity than pure Ta2O5.
Catalytic Asymmetric Aziridination of α,β‐Unsaturated Aldehydes
Authors: Deiana Luca , Dziedzic Pawel , Zhao Gui‐Ling , Vesely Jan , Ibrahem Ismail , Rios Ramon , Sun Junliang , Córdova Armando 
Published: May 2011

AbstractThe development, scope, and application of the highly enantioselective organocatalytic aziridination of α,β‐unsaturated aldehydes is presented. The aminocatalytic azirdination of α,β‐unsaturated aldehydes enables the asymmetric formation of β‐formyl aziridines with up to >19:1 d.r. and 99 % ee. The aminocatalytic aziridination of α‐monosubstituted enals gives access to terminal α‐substituted‐α‐formyl aziridines in high yields and up to 99 % ee. In the case of the organocatalytic aziridination of disubstituted α,β‐unsaturated aldehydes, the transformations were highly diastereo‐ and enantioselective and give nearly enantiomerically pure β‐formyl‐functionalized aziridine products (99 % ee). A highly enantioselective one‐pot cascade sequence based on the combination of asymmetric amine and N‐heterocyclic carbene catalysis (AHCC) is also disclosed. This one‐pot three‐component co‐catalytic transformation between α,β‐unsaturated aldehydes, hydroxylamine derivatives, and alcohols gives the correspondingN‐tert‐butoxycarbonyl andN‐carbobenzyloxy‐protected β‐amino acid esters witheevalues ranging from 92–99 %. The mechanisms and stereochemistry of all these catalytic transformations are also discussed.
Chemical Modulation of Peptoids: Synthesis and Conformational Studies on Partially Constrained Derivatives
Authors: Moure Alejandra , Sanclimens Glòria , Bujons Jordi , Masip Isabel , Alvarez‐Larena Angel , Pérez‐Payá Enrique , Alfonso Ignacio , Messeguer Angel 
Published: May 2011

AbstractThe high conformational flexibility of peptoids can generate problems in biomolecular selectivity as a result of undesired off‐target interactions. This drawback can be counterbalanced by restricting the original flexibility to a certain extent, thus leading to new peptidomimetics. By starting from the structure of an active peptoid as an apoptosis inhibitor, we designed two families of peptidomimetics that bear either 7‐substituted perhydro‐1,4‐diazepine‐2,5‐dione 2 or 3‐substituted 1,4‐piperazine‐2,5‐dione 3 moieties. We report an efficient, solid‐phase‐based synthesis for both peptidomimetic families 2 and 3 from a common intermediate. An NMR spectroscopic study of 2 a,b and 3 a,b showed two species in solution in different solvents that interconvert slowly on the NMR timescale. The cis/trans isomerization around the exocyclic tertiary amide bond is responsible for this conformational behavior. The cis isomers are more favored in nonpolar environments, and this preference is higher for the six‐membered‐ring derivative 3 a,b. We propose that the hydrogen‐bonding pattern could play an important role in the cis/trans equilibrium process. These hydrogen bonds were characterized in solution, in the solid state (i.e., by using X‐ray studies), and by molecular modeling of simplified systems. A comparative study of a model peptoid 10 containing the isolated tertiary amide bond under study outlined the importance of the heterocyclic moiety for the prevalence of the cis configuration in 2 a and 3 a. The kinetics of the cis/trans interconversion in 2 a, 3 a, and 10 was also studied by variable‐temperature NMR spectroscopic analysis. The full line‐shape analysis of the NMR spectra of 10 revealed negligible entropic contribution to the energetic barrier in this conformational process. A theoretical analysis of 10 supported the results observed by NMR spectroscopic analysis. Overall, these results are relevant for the study of the peptidomimetic/biological‐target interactions.
Self‐Assembled Arene–Ruthenium‐Based Rectangles for the Selective Sensing of Multi‐Carboxylate Anions
Authors: Vajpayee Vaishali , Song Young Ho , Lee Min Hyung , Kim Hyunuk , Wang Ming , Stang Peter J. , Chi Ki‐Whan 
Published: May 2011

AbstractNovel arene–ruthenium [2+2] metalla‐rectangles 4 and 5 have been synthesized by self‐assembly using dipyridyl amide ligand 3 and arene–ruthenium acceptors (arene: benzoquinone (1), naphthacenedione (2)) and characterized by NMR spectroscopy and ESI‐MS. The solid‐state structure of 5 was determined by X‐ray diffraction and shows encapsulated diethyl ether molecule in the rectangular cavity of 5. The luminescent 5 was further used for anion sensing with the amidic linkage serving as a hydrogen‐bond donor site for anions and the ruthenium moiety serving as a signaling unit. A UV/Vis titration study demonstrated that although 5 interacts very weakly with common monoanions as well as with flexible dicarboxylate anions such as malonate and succinate, it displays significant binding affinity (K>103 in MeOH) for rigid multi‐carboxylate anions such as oxalate, citrate, and tartrate, exhibiting a 1:1 stoichiometry. It has been suggested that 1:1 bidentate hydrogen bonding assisted by appropriate geometrical complementarity is mainly responsible for the increased affinity of 5 towards such anions. A fluorescence titration study revealed a large fluorescence enhancement of 5 upon binding to multi‐carboxylate anions, which can be attributed to the blocking of the photoinduced electron‐transfer process from the arene–Ru moiety to the amidic donor in 5 as a result of hydrogen bonding between the donor and the anion.
Source Based Characterization and Pollution Profile of a Baker's Yeast Industry
Authors: Ersahin Mustafa Evren , Dereli Recep Kaan , Ozgun Hale , Donmez Berivan Gunes , Koyuncu Ismail , Altinbas Mahmut , Ozturk Izzet 
Published: May 2011

AbstractBaker's yeast industry has significant effects on environment due to significant water consumption and high strength wastewater production. Effluents from baker's yeast industry are characterized by high concentrations of biological oxygen demand (BOD5), chemical oxygen demand (COD), total Kjeldahl nitrogen (TKN), total dissolved solids (TDS), sulfate, and dark brown color. The aim of this study is to provide a detailed quantitative and qualitative identification and characterization of the wastewater sources from different processes of a baker's yeast industry. It is identified that the most polluted wastewater components of the facility are coming from rotary drum filter and evaporation process. However, the highest pollution loads is identified as tank and equipment cleaning effluent due to very high flow rate from this source. The efforts should be on the way to minimize the water usage for the tank and equipment cleaning process, and to recycle less polluted waste streams back to the process.
Coordination Behavior and Coligand‐Dependent cis/trans Isomerism of Calcium Bis(diphenylphosphanides)
Authors: Langer Jens , Al‐Shboul Tareq M. A. , Younis Fadi M. , Görls Helmar , Westerhausen Matthias 
Published: May 2011

AbstractThe salt metathesis reaction of KPPh2 with CaI2 and SrI2 in THF yields the corresponding complexes [(THF)4Ae(PPh2)2] [Ae = Ca (1), Sr]. Depending on the crystallization conditions, cis‐ or trans‐[(THF)4Ca(PPh2)2] can be isolated. In solution, a fast equilibrium converts these isomers into each other leading to a single set of resonances in the NMR spectra. The THF ligands can be replaced by stronger Lewis bases, such as N‐methylimidazole (MeIm), which leads to the formation of [(MeIm)4Ae(PPh2)2] [Ae = Ca (2a), Sr (2b)]. The use of tetradentate hexamethyltriethylenetetramine (hmteta) fixes a cis configuration yielding [(hmteta)Ca(PPh2)2] (3). All compounds are very air and moisture sensitive, therefore a few crystals of the partially oxidized product [(hmteta)Ca(PPh2)(OPPh2)] (4) were also obtained.
Oxidative Bond Formation in Dithienyl Polyphenylenes: Optical and Electrochemical Consequences
Authors: Martin Colin J. , Gil Belen , Perera Sarath D. , Draper Sylvia M. 
Published: May 2011

AbstractA new set of dithienyl polyphenylenes was prepared with a view of developing sulfur‐containing polyaromatic hydrocarbons (PAHs) by oxidative cyclodehydrogenation. The first of these, 1,2‐bis(5‐methyl‐2‐thienyl)‐3,4,5,6‐tetra‐(4‐tert‐butylphenyl)benzene (1) was sterically hindered at the 5‐positions of the thienyl rings and under Lewis acid catalyzed cyclodehydrogenation gave monomeric intramolecularly fused dithienyl 3, which was spectroscopically and structurally characterized. Under the same conditions, three unhindered dithienyl polyphenylenes, 1,2‐(thienyl)‐3,4,5,6‐tetra(4‐tert‐butylphenyl)s 2, 5, and 6, underwent both thiophene‐directed intra‐ and intermolecular C–C bond fusions. The resulting dimers 4, 7, and 8 were identified through a series of 1H, 13C, and 2D NMR experiments. The electrochemical and photophysical properties of the dimers were examined. Their optical properties reflect the coplanarity or otherwise of their cojoined parts. The electrochemical oxidation of the dithienyl polyphenylene precursors showed a relationship between the ease of oxidation and the availability of the 2‐ and 5‐positions on the thienyl rings. Using spectroelectrochemical methods the electrochemically oxidized and chemically oxidized products were compared.
Nickel‐Catalyzed [2+2+2] Cycloaddition of Diynes and Cyanamides
Authors: Stolley Ryan M. , Maczka Michael T. , Louie Janis 
Published: May 2011

AbstractA variety of bicyclic N,N‐disubstituted 2‐aminopyridines have been prepared from diynes and cyanamides by nickel‐catalyzed [2+2+2] cycloaddition reactions. The reactions proceeded at room temperature with low catalyst loading to afford 2‐aminopyridines in good to excellent yields. The method is amenable to both internal and terminal diynes and proceeds in a regioselective manner. A number of cyanamides with diverse functional group tolerance were used. The intermolecular version employing 3‐hexyne and N‐cyanopyrrolidine also afforded the desired N,N‐disubstituted 2‐aminopyridine in good yield.
Opposite Enantiomers from Minor Enantiomer Recycling and Dynamic Kinetic Resolution Using a Single Biocatalyst
Authors: Laurell Anna , Moberg Christina 
Published: May 2011

AbstractA one‐pot recycling procedure comprising Lewis acid catalyzed enantioselective addition of acetyl cyanide to (E)‐2‐butenal to give the O‐acetylated cyanohydrin and enzyme‐catalyzed conversion of the minor product enantiomer back to (E)‐2‐butenal provided essentially enantiopure (2R,3E)‐2‐acetoxy‐3‐pentenenitrile in close to quantitative yield. The opposite enantiomer was obtained, albeit in lower yield and with lower enantiomeric purity than that observed from the minor enantiomer recycling, by dynamic kinetic resolution consisting of reversible addition of HCN to the aldehyde coupled to enzyme‐catalyzed acetylation of the cyanohydrin.
Concern for self‐image and social image in the management of moral failure: Rethinking shame
Authors: Gausel Nicolay , Leach Colin Wayne 
Published: May 2011

AbstractMoral failure is thought to damage self‐image when people appraise it as indicating a global self‐defect. This appraisal is thought to be associated with the feeling of shame and thus self‐defensive motivation. However, a damaged social image better explains self‐defensive motivation to hide from and avoid others. Based on an integrative review of theory and research, we offer a conceptual model of how concern for self‐image and social image guides the experience of moral failure. The model distinguishes the appraisals (of self‐defect and other‐condemnation) and feelings (of rejection, inferiority, and shame) embedded in the shame concept. Concern for a damaged social image is represented in another‐condemnation→rejectioncombination, whereas concern for a damaged self‐image is represented in a(global) self‐defect→inferioritycombination. As these appraisal–feeling combinations are concerned with damage done to one's image, they should be linked to self‐defensive motivation. As the(specific) self‐defect→shamecombination is concerned with a repairable defect in self‐image, it should be linked with self‐improvement motivation. Thus, our model explains why “shame” is sometimes tied to self‐defensive motivation and sometimes tied to self‐improvement motivation after moral failure. Copyright © 2011 John Wiley & Sons, Ltd.
Self‐ and Other‐presentational styles in the Southern and Northern United States: An analysis of personal ads
Authors: Lun Janetta , Mesquita Batja , Smith Benjamin 
Published: May 2011

AbstractTwo studies examined regional differences in self‐ and other‐presentational styles in the Southern and Northern regions of the USA. A content analysis of 400 personal ads from Northern and Southern newspapers revealed that Northern ads contained more descriptions of the self and desired partner that are context‐free and under personal control, whereas Southern ads depicted more contextualized and less controllable aspects of self and partner (study 1). Moreover, self‐identified Northern and Southern Americans were shown to prefer ads in the style of their region over other ads (study 2). We conclude that not only do regional differences in self‐ and other‐presentations exist in the USA but that these differences are also reinforced by others who share the regional culture. Copyright © 2011 John Wiley & Sons, Ltd.
Biotin‐modified glutathione as a functionalized coating for bioconjugation of CdTe‐based quantum dots
Authors: Ryvolova Marketa , Chomoucka Jana , Janu Libor , Drbohlavova Jana , Adam Vojtech , Hubalek Jaromir , Kizek Rene 
Published: May 2011

AbstractIn this study, biotin‐conjugated glutathione was synthesized using peptide bonding of the biotin carboxy group and amino group of the γ‐glutamic acid to prepare an alternative coating for CdTe quantum dots (QDs). This type of coating combines the functionality of the biotin with the fluorescent properties of the QDs to create a specific, high‐affinity fluorescent probe able to react with avidin, streptavidin and/or neutravidin. Biotin‐functionalized glutathione‐coated CdTe QDs were prepared by a simple one‐step method using Na2TeO3 and CdCl2. Obtained QDs were separated from the excess of the biotin‐conjugated glutathione by CE employing 300 mM borate buffer with pH 7.8 as a background electrolyte. The detection of sample components was performed by the photometric detection at 214 nm and LIF employing Ar+ ion laser (488 nm).
Horizontal floor response spectra of base‐isolated buildings due to vertical excitation
Authors: Politopoulos Ioannis , Moussallam Nadim 
Published: May 2011

SUMMARYA mechanism of horizontal floor response spectra amplification in the vicinity of higher modes' frequencies is investigated. It is demonstrated, by means of a simple two‐degrees‐of‐freedom model, that in the case of unsymmetrical superstructure, such amplification may occur because of the coupling between vertical excitation and horizontal response of the non‐isolated modes. This phenomenon is further illustrated by the results of analyses of a model of a nuclear plant. Copyright © 2011 John Wiley & Sons, Ltd.
Application of an S‐shaped curve model to the temporal development of tafoni of salt‐weathering origin
Authors: Sunamura Tsuguo , Aoki Hisashi 
Published: May 2011

ABSTRACTTo describe temporal change in tafone development, an S‐shaped curve equation is proposed: Z = Zc [1 − (n + 1) exp (− β t ) + n exp (− (1 + 1/n) β t )] , where Z is observed tafone depth, Zc is ultimate tafone depth, t is time, and n and β are constants. The applicability of this model is examined using tafone data selected from seven sites, which are categorized into three different salt‐weathering environments: a spray/splash‐dominant (occasionally wave‐affected) supra‐tidal zone, aerosol‐affected coastal regions, and inland desert areas. The results indicate that the equation can well describe tafone development in each of these environments. An investigation based on the values of n and β, determined through a best fit of the equation to the data, suggests that n characterizes site‐specific environmental conditions and β reflects the magnitude of factors controlling the recession mechanism of tafone surfaces. It is found that (1) the maximum rate of tafone growth dramatically decreases from supra‐tidal, through coastal, to desert environments, and (2) the growing mode of tafoni is different depending on the environmental settings. The erosional force to facilitate the development of tafoni at supra‐tidal sites is estimated to be about 400 times greater than that in the general coastal area. Copyright © 2011 John Wiley & Sons, Ltd.