bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biotechnology, 6. Special Applications
Authors: Doelle Horst Werner , Fiechter Armin , van Griensven Martijn , Kasper Cornelia , Pörtner Ralf , Schlegel Günther , Shimizu Sakayu , Stahl Frank , Suck Kirstin , Yamada Hideaki , Zorn Holger 
Published: July 2009

AbstractThe article contains sections titled:1.Mammalian Cell Culture Technology1.1.Introduction1.2.Products from Mammalian Cells1.3.Cell Types1.4.Growth Medium for Cell Culture1.5.Small‐Scale Culture Systems for Routine Use1.6.Types of Bioreactors1.7.Process Strategies1.8.Downstream Processes1.9.Regulatory and Safety Issues2.Tissue Engineering2.1.Application of Tissue Engineering2.2.Principle of Tissue Engineering2.3.Strategies2.4.The Essentials2.5.Cells2.6.Biomatrices2.7.Bioreactors for Tissue Engineering2.8.Growing New from Old3.Biotechnology and Food3.1.Production of Food Additives by Cell Culture Systems3.1.1.Amino Acids3.1.2.Organic Acids3.1.3.Vitamins3.1.4.Sweet Compounds3.1.5.Sugar Alcohols3.1.6.Microbial Saccharides3.1.7.Conjugated Linoleic Acids (CLA)3.1.8.Lactulose3.2.Enzyme‐Catalyzed Processes3.2.1.Starch‐Modifying Enzymes3.2.2.Lipases3.2.3.Pectin‐Degrading Enzymes3.2.4.Chymosin (Aspartic Protease)4.Biotechnology and Health4.1.Individualized Medicine4.2.Clinical Diagnosis as Indicated in Genetic Anomalies in Cancer4.3.Pharmaceutical Development4.4.Define Molecular Mechanisms of Toxicity4.5.Detection of Genetically Modified Organisms
Stability of Second Generation Grubbs’ Alkylidenes to Primary Amines: Formation of Novel Ruthenium‐Amine Complexes
Authors: Wilson Gerald O. , Porter Keith A. , Weissman Haim , White Scott R. , Sottos Nancy R. , Moore Jeffrey S. 
Published: July 2009

AbstractThe stability of second generation Grubbs’ alkylidenes to primary amines relative to the first generation derivatives is investigated. For both Grubbs’ alkylidene derivatives, the tricyclohexylphosphine (PCy3) ligand is displaced by n‐butylamine and diethylenetriamine. However, while displacement of PCy3 in first generation Grubbs’ alkylidene derivatives results in decomposition of the catalyst, the N‐heterocyclic carbene (NHC) ligand in second generation derivatives is not displaced by primary amines present in up to 100 equivalents. The result is the formation of new stable ruthenium‐amine complexes. These complexes are characterized and their catalytic activity is evaluated in ring‐closing metathesis (RCM) and ring‐opening metathesis (ROMP) reactions. While the amine complexes evaluated were minimally active in RCM reactions, the ruthenium‐butylamine complex was significantly active in ROMP and exhibited an initiation rate constant that was at least an order of magnitude greater than that of the second generation Grubbs’ alkylidene from which it was synthesized.
Efficient Aerobic Oxidation of Alcohols using a Hydrotalcite‐Supported Gold Nanoparticle Catalyst
Authors: Mitsudome Takato , Noujima Akifumi , Mizugaki Tomoo , Jitsukawa Koichiro , Kaneda Kiyotomi 
Published: July 2009

AbstractHydrotalcite‐supported gold nanoparticles (Au/HT) were found to be a highly efficient heterogeneous catalyst for the aerobic oxidation of alcohols under mild reaction conditions (40 °C, in air). This catalyst system does not require any additives and is applicable to a wide range of alcohols, including less reactive cyclohexanol derivatives. This Au/HT catalyst could also function in the oxidation of 1‐phenylethanol under neat conditions; the turnover number (TON) and turnover frequency (TOF) reached 200,000 and 8,300 h−1, respectively. These values are among the highest values compared to those of other reported catalyst systems at high conversion. Moreover, the Au/HT can be recovered by simple filtration and reused without any loss of its activity and selectivity.
Effects of bias combustion on volatile nitrogen transformation
Authors: Zhang Xiaohui , Sun Shaozeng , Sun Rui , Li Xiaoli , Zeng Guang 
Published: July 2009

AbstractNitrogen oxides (NOx) are among the principal pollutants from coal combustion, which have caused serious environmental issues around the world. Many advanced combustion systems have been developed to reduce NOx emissions. Technologies that combine low NOx burners (LNB) and air staging systems have been widely used as they can control the formation of volatile NOx effectively. In this paper, the process of volatile nitrogen release was simulated using the FG–DVC pyrolysis model, in order to provide reliable reference for designing LNBs and air staging combustion systems. The mechanism of NOx emission from volatile N in a combustion system was studied with CHEMKIN 4.1 package, which demonstrated that noticeable reduction of NOx could be obtained at an equivalence ratio (ER) of 1.22, which was 3–4% and 10–15% higher than that at an ER of 0.77 and 0.39, respectively. Sensitivity study of all basic reactions indicated that NH2 and HCNO radicals are the major inter‐compounds which can reduce NO at bias combustion conditions. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Stability of sulfonated polytriazole and polyoxadiazole membranes
Authors: Ponce Mariela Leticia , Roeder Jerusa , Gomes Dominique , Nunes Suzana P. 
Published: July 2009

AbstractThe performance and stability of sulfonated polytriazoles with polymer backbones containing diphenyl ether (S‐DPE‐PT) and hexafluorisopropylidene groups (S‐FPT) were compared, aiming their application as proton conductive membranes for fuel cell. The chemical stability of both membranes were compared and analyzed by infrared spectroscopy after 24 h heating at temperatures up to 250 °C. The superior stability of the fluorinated polytriazole was confirmed. Copyright © 2009 Curtin University of Technology and John Wiley & Sons, Ltd.
Decreased GABAA receptors and benzodiazepine binding sites in the anterior cingulate cortex in autism
Authors: Oblak A. , Gibbs T.T. , Blatt G.J. 
Published: July 2009

AbstractThe anterior cingulate cortex (ACC; BA 24) via its extensive limbic and high order association cortical connectivity to prefrontal cortex is a key part of an important circuitry participating in executive function, affect, and socio‐emotional behavior. Multiple lines of evidence, including genetic and imaging studies, suggest that the ACC and gamma‐amino‐butyric acid (GABA) system may be affected in autism. The benzodiazepine binding site on the GABAA receptor complex is an important target for pharmacotherapy and has important clinical implications. The present multiple‐concentration ligand‐binding study utilized 3H‐muscimol and 3H‐flunitrazepam to determine the number (Bmax), binding affinity (Kd), and distribution of GABAA receptors and benzodiazepine binding sites, respectively, in the ACC in adult autistic and control cases. Compared to controls, the autistic group had significant decreases in the mean density of GABAA receptors in the supragranular (46.8%) and infragranular (20.2%) layers of the ACC and in the density of benzodiazepine binding sites in the supragranular (28.9%) and infragranular (16.4%) lamina. In addition, a trend for a decrease in for the density of benzodiazepine sites was found in the infragranular layers (17.1%) in the autism group. These findings suggest that in the autistic group this downregulation of both benzodiazepine sites and GABAA receptors in the ACC may be the result of increased GABA innervation and/or release disturbing the delicate excitation/inhibition balance of principal neurons as well as their output to key limbic cortical targets. Such disturbances likely underlie the core alterations in socio‐emotional behaviors in autism.
Order‐restricted Scores Test for the Evaluation of Population‐based Case–control Studies when the Genetic Model is Unknown
Authors: Hothorn Ludwig A. , Hothorn Torsten 
Published: July 2009

AbstractThe Cochran–Armitage (CA) linear trend test for proportions is often used for genotype‐based analysis of candidate gene association. Depending on the underlying genetic mode of inheritance, the use of model‐specific scores maximises the power. Commonly, the underlying genetic model, i.e. additive, dominant or recessive mode of inheritance, is a priori unknown. Association studies are commonly analysed using permutation tests, where both inference and identification of the underlying mode of inheritance are important. Especially interesting are tests for case–control studies, defined by a maximum over a series of standardised CA tests, because such a procedure has power under all three genetic models. We reformulate the test problem and propose a conditional maximum test of scores‐specific linear‐by‐linear association tests. For maximum‐type, sum and quadratic test statistics the asymptotic expectation and covariance can be derived in a closed form and the limiting distribution is known. Both the limiting distribution and approximations of the exact conditional distribution can easily be computed using standard software packages. In addition to these technical advances, we extend the area of application to stratified designs, studies involving more than two groups and the simultaneous analysis of multiple loci by means of multiplicity‐adjusted p‐values for the underlying multiple CA trend tests. The new test is applied to reanalyse a study investigating genetic components of different subtypes of psoriasis. A new and flexible inference tool for association studies is available both theoretically as well as practically since already available software packages can be easily used to implement the suggested test procedures.
Rounding Strategies for Multiply Imputed Binary Data
Authors: Demirtas Hakan 
Published: July 2009

AbstractMultiple imputation (MI) has emerged in the last two decades as a frequently used approach in dealing with incomplete data. Gaussian and log‐linear imputation models are fairly straightforward to implement for continuous and discrete data, respectively. However, in missing data settings that include a mix of continuous and discrete variables, the lack of flexible models for the joint distribution of different types of variables can make the specification of the imputation model a daunting task. The widespread availability of software packages that are capable of carrying out MI under the assumption of joint multivariate normality allows applied researchers to address this complication pragmatically by treating the discrete variables as continuous for imputation purposes and subsequently rounding the imputed values to the nearest observed category. In this article, we compare several rounding rules for binary variables based on simulated longitudinal data sets that have been used to illustrate other missing‐data techniques. Using a combination of conditional and marginal data generation mechanisms and imputation models, we study the statistical properties of multiple‐imputation‐based estimates for various population quantities under different rounding rules from bias and coverage standpoints. We conclude that a good rule should be driven by borrowing information from other variables in the system rather than relying on the marginal characteristics and should be relatively insensitive to imputation model specifications that may potentially be incompatible with the observed data. We also urge researchers to consider the applied context and specific nature of the problem, to avoid uncritical and possibly inappropriate use of rounding in imputation models.
Charge‐Transfer State and Large First Hyperpolarizability Constant in a Highly Electronically Coupled Zinc and Gold Porphyrin Dyad
Authors: Fortage Jérôme , Scarpaci Annabelle , Viau Lydie , Pellegrin Yann , Blart Errol , Falkenström Magnus , Hammarström Leif , Asselberghs Inge , Kellens Ruben , Libaers Wim , Clays Koen , Eng Mattias P. , Odobel Fabrice 
Published: July 2009

AbstractWe report the synthesis and the characterizations of a novel dyad composed of a zinc porphyrin (ZnP) linked to a gold porphyrin (AuP) through an ethynyl spacer. The UV/Vis absorption spectrum and the electrochemical properties clearly reveal that this dyad exhibits a strong electronic coupling in the ground state as evidenced by shifted redox potentials and the appearance of an intense charge‐transfer band localized at λ=739 nm in dichloromethane. A spectroelectrochemical study of the dyad along with the parent homometallic system (i.e., ZnP–ZnP and AuP–AuP) was undertaken to determine the spectra of the reduced and oxidized porphyrin units. Femtosecond transient absorption spectroscopic analysis showed that the photoexcitation of the heterometallic dyad leads to an ultrafast formation of a charge‐separated state (+ZnP–AuP.) that displays a particularly long lifetime (τ=4 ns in toluene) for such a short separation distance. The molecular orbitals of the dyad were determined by DFT quantum‐chemical calculations. This theoretical study confirms that the observed intense band at λ=739 nm corresponds to an interporphyrin charge‐transfer transition from the HOMO orbital localized on the zinc porphyrin to LUMO orbitals localized on the gold porphyrin. Finally, a Hyper–Rayleigh scattering study shows that the dyad possesses a large first molecular hyperpolarizability coefficient (β=2100×10−30 esu at λ=1064 nm), thus highlighting the valuable nonlinear optical properties of this new type of push–pull porphyrin system.
A High‐Barrier Molecular Balance for Studying Face‐to‐Face Arene–Arene Interactions in the Solid State and in Solution
Authors: Chong Yong S. , Carroll William R. , Burns William G. , Smith Mark D. , Shimizu Ken D. 
Published: July 2009

AbstractAn atropisomeric molecular balance was developed to study face‐to‐face arene–arene interactions. The balance has a large central 1,4,5,8‐naphthalene diimide surface that forms intramolecular arene–arene interactions with two pendent arms. The balance adopts distinct syn and anti isomers with varying numbers of intramolecular interactions. Thus, the strength of the arene–arene interaction could be quantitatively measured by NMR spectroscopy from the anti/syn ratios. The size of the arene arms was easily varied, which allowed examination of the relationship between arene size and strength of the interaction. A nonlinear size dependence was observed in solution with larger arene arms having a disproportionately stronger arene–arene interaction. The intramolecular arene–arene interactions were also characterized in the solid state by X‐ray crystallography. These studies were facilitated by the kinetic stability of the syn and anti isomers at room temperature due to the high isomerization barrier (ΔG=27.0 kcal mol−1). Thus, the anti isomer could be selectively isolated and crystallized in its folded conformation. The X‐ray structures confirmed that the anti isomers formed two strong intramolecular arene–arene interactions with face‐to‐face geometries. The solid‐state structure analysis also reveals that the rigid framework may contribute to the observed nonlinear size trend. The acetate linker is slightly too long, which selectively destabilizes the balances with smaller arene arms. The larger arene arms are able to compensate for the longer linker and form effective intramolecular arene–arene interactions.
Rotational Spectrum of the Mixed van der Waals Triad Pyridine–Ar–Ne
Authors: Melandri Sonia , Giuliano Barbara M. , Maris Assimo , Evangelisti Luca , Velino Biagio , Caminati Walther 
Published: July 2009

AbstractWe report the Fourier transform microwave spectra of four isotopologues of the hetero triad pyridine–Ar–Ne, formed by the combination of two isotopes of the nitrogen atom (14N and 15N) in pyridine with two isotopes of the rare gas (RG) atoms (20Ne and 22Ne), by using pulsed jet spectroscopy. We detected the conformer denoted [1,1], with the Ne and Ar atoms located one on each side of the ring plane. The [2,0] species, with the two RG atoms on the same side of the ring, was not observed. Ab initio MP2/6‐311++G** calculations suggest the rotational spectrum of this species to be complicated by the presence of several almost equivalent minima, separated by very low barriers. Four structural van der Waals parameters, RAr, RNe, θAr and θNe, which localize the RG atoms with respect to pyridine, are determined. The 14N nuclear quadrupole coupling constants are obtained for the isotopologues containing this nucleus.
Regioselective Metal‐Catalyzed Hydrophosphinylation of Alkynes: Synthesis of Enantiopure α‐ or β‐Substituted Vinylphosphane Oxides
Authors: Duraud Amélie , Toffano Martial , Fiaud Jean‐Claude 
Published: July 2009

AbstractPalladium was found to catalyze regioselective Markovnikov addition of chiral enantiopure 1r‐oxo‐2c,5t‐diphenylphospholane (1) to terminal alkynes, whereas rhodium catalysis offers selectively the (E)‐anti‐Markovnikov adduct. This strategy offers rapid access to chiral and enantiopure α‐ or β‐substituted‐1‐alkenylphospholanes. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Preparation and evaluation of a sulfoalkylbetaine‐based zwitterionic monolithic column for CEC of polar analytes
Authors: Wang Xiaochun , Lin Xucong , Xie Zenghong 
Published: July 2009

AbstractA novel polymethacrylate‐based monolithic column with covalently bonded zwitterionic functional groups was prepared by in situ copolymerization of N,N‐dimethyl‐N‐methacryloxyethyl N‐(3‐sulfopropyl) ammonium betaine (SPE), pentaerythritol triacrylate (PETA), and vinylsulfonic acid (VS) in a binary porogenic solvent consisting of cyclohexanol and ethylene glycol. This monolith was developed as a separation column for CEC. While SPE functioned as both an electrostatic interaction stationary phase and the polar ligand provider, VS was employed to generate EOF. PETA, which has much more hydrophilicity due to a hydroxyl sub‐layer, was used to replace ethylene dimethacrylate as a cross‐linker. The monolith provided an adequate EOF when VS level was maintained at 0.6% w/w. Different monolithic stationary phases were easily prepared by adjusting the ratio of PETA/SPE in the polymerization solution as well as the composition of the porogenic solvent. The observed RSD were ≤3.6, ≤4.3 and ≤5.6% for the EOF velocity, retention time, and column efficiency, respectively. The column efficiencies greater than 145 000 theoretical plates/m for thiourea and 132 000 theoretical plates/m for charged cytidine were obtained. The poly(SPE‐co‐PETA‐co‐VS) monolith showed good selectivity for neutral and charged polar analytes. It was found that the separation mechanism of charged polar solutes was attributed to a mixed mode of hydrophilic interaction and electrostatic interaction, as well as electrophoresis. No peak tailing was observed for the separation of basic compounds, such as basic nucleic acid bases and nucleoside on the monolith.
About the role of enantioselective selector–selectand interactions and the mobilities of diastereomeric associates in enantiomer separations using CE
Authors: Lomsadze Ketevan , Martínez‐Girón Ana B. , Castro‐Puyana María , Chankvetadze Lali , Crego Antonio L. , Salgado Antonio , Marina María Luisa , Chankvetadze Bezhan 
Published: July 2009

AbstractIt is generally accepted that the selective binding of enantiomers of the chiral analyte to a chiral selector is necessary for enantioseparations in CE, whereas the role of mobility differences between the temporary diastereomeric associates formed between the enantiomers and the chiral selector has been commonly neglected. One of the authors of this study suggested in 1997 that the mobility difference between the diastereomeric associates of two enantiomers with the chiral selector may be solely responsible for a separation of enantiomers in CE and enantioselective selector–selectand binding may be not necessarily required. Several indirect confirmations of this hypothesis have been described in the literature within the last few years but a dedicated study proving this concept has not been published yet. The present data obtained for the two chiral antimycotic drugs ketoconazole and terconazole by CE and NMR spectroscopy unequivocally support this concept.
Simultaneous separation of epinephrine and norepinephrine enantiomers by EKC: Application to the analysis of pharmaceutical formulations
Authors: Castro‐Puyana María , Drewnowska Renata , Pérez‐Fernández Virginia , Ángeles García María , Crego Antonio L. , Marina María Luisa 
Published: July 2009

AbstractA new analytical methodology using EKC with a CD as chiral selector was developed enabling the simultaneous enantiomeric separation of two chiral neurotransmitters (epinephrine and norepinephrine). Different experimental conditions (type and concentration of the chiral selector, nature and concentration of buffer and separation voltage) were optimized. The use of 10 mM carboxyethyl‐β‐CD in 100 mM Tris‐phosphate buffer (pH 5.0) with an applied voltage of 30 kV and a temperature of 15°C allowed the separation of epinephrine and norepinephrine enantiomers with high chiral resolution (Rs>2.5). Moreover, after evaluating the analytical characteristics of the method, it was applied to the quantitation and purity testing of L‐epinephrine as active pharmaceutical ingredient in pharmaceutical formulations where D‐epinephrine and L/D‐norepinephrine can be present as impurities.
Analysis of genetic variation in Globocephaloides populations from macropodid marsupials using a mutation scanning‐based approach
Authors: Fazenda Inês P. , Beveridge Ian , Chilton Neil B. , Jex Aaron R. , Pangasa Aradhana , Campbell Bronwyn E. , Huby‐Chilton Florence , Carvalho Luís M. , Gasser Robin B. 
Published: July 2009

AbstractThree species of Globocephaloides, parasitic nematodes occurring in macropodid marsupials in different areas of Australia, were characterized by the sequences of the first and second internal transcribed spacers (ITS‐1 and ITS‐2) of nuclear ribosomal DNA. Samples were subjected to PCR‐coupled SSCP analysis and targeted sequencing, in order to assess genetic variation within and among individuals from different host species. Both SSCP and sequence data supported the current classification of morphospecies. Contrary to a previous hypothesis that cryptic species exist within the Globocephaloides trifidospicularis “complex”, no or minor (0.2%) variation was detected among individuals from different hosts or geographical origins. Within G. macropodis populations, there was a consistent difference in both the ITS‐1 (5.2%) and ITS‐2 (7.1%) sequences between individuals derived from Macropus agilis and those from Macropus dorsalis. Although the results suggested that G. macropodis from each host species represented sibling species, future morphological study of individuals representing each G. macropodis genotype is warranted to provide further support for this hypothesis. (Nucleotide sequence data have been deposited in the GenBank database under accession nos. GQ131400‐GQ131409.)
On the statistical description of the AoA of the uplink interfering signals in a cellular communication system
Authors: Baltzis Konstantinos B. , Sahalos John N. 
Published: July 2009

AbstractA common assumption in the analysis and modelling of co‐channel interference (CCI) is the circular shape of the cells. However, despite its simplicity, this approach has certain drawbacks. In this paper, we propose an alternative approximate method which considers hexagonal‐shaped cells. We develop a geometrical‐based stochastic model and derive analytical expressions for the statistics of the angle‐of‐arrival of the uplink interfering signals in a cellular system. Simulations performed exhibit the characteristics of our proposal and evaluate both hexagonal and circular approximations. The impact of various parameters on the performance of a cellular system is also investigated. The derived expressions simplify the analysis of wireless networks and improve the accuracy of the simulations when hexagonal cells are employed. Copyright © 2009 John Wiley & Sons, Ltd.