bluuebunny/crossref_metadata_2025_split huggingface dataset:
Output feedback integral sliding mode controller of time‐delay systems with mismatch disturbances
Authors: Ting Huan‐Chan , Chang Jeang‐Lin , Chen Yon‐Ping 
Published: September 2011

AbstractFor uncertain time‐delay systems with mismatch disturbances, this paper presented an integral sliding mode control algorithm using output information only. An integral sliding surface is comprised of output signals and an auxiliary full‐order compensator. The designed output feedback sliding mode controller can locally satisfy the reaching and sliding condition and maintain the system on the sliding surface from the initial moment. Since the system is in the sliding mode and two specific algebraic Riccati inequalities are established, the proposed algorithm can guarantee the stability of the closed‐loop system and satisfy the property of disturbance attenuation. Moreover, the design parameters of the controller and compensator can be simultaneously determined by solutions to two algebraic Riccati inequalities. Finally, a numerical example illustrates the applicability of the proposed scheme.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
A guide to stem cell identification: Progress and challenges in system‐wide predictive testing with complex biomarkers
Authors: Williams Roy , Schuldt Bernhard , Müller Franz‐Josef 
Published: September 2011

AbstractWe have developed a first generation tool for the unbiased identification and characterization of human pluripotent stem cells, termed PluriTest. This assay utilizes all the information contained on a microarray and abandons the conventional stem cell marker concept. Stem cells are defined by the ability to replenish themselves and to differentiate into more mature cell types. As differentiation potential is a property that cannot be directly proven in the stem cell state, biologists have to rely on correlative measurements in stem cells associated with differentiation potential. Unfortunately, most, if not all, of those markers are only valid within narrow limits of specific experimental systems. Microarray technologies and recently next‐generation sequencing have revolutionized how cellular phenotypes can be characterized on a systems‐wide level. Here we discuss the challenges PluriTest and similar global assays need to address to fulfill their enormous potential for industrial, diagnostic and therapeutic applications.
Simultaneous use of urea and potassium nitrate for Arthrospira (Spirulina) platensis cultivation
Authors: Vieira Denise C. M. , Matsudo Marcelo C. , Sato Sunao , Converti Attilio , de Carvalho João C. M. 
Published: September 2011

AbstractUrea has been considered as a promising alternative nitrogen source for the cultivation of Arthrospira platensis if it is possible to avoid ammonia toxicity; however, this procedure can lead to periods of nitrogen shortage. This study shows that the addition of potassium nitrate, which acts as a nitrogen reservoir, to cultivations carried out with urea in a fed‐batch process can increase the maximum cell concentration (Xm) and also cell productivity (PX). Using response surface methodology, the model indicates that the estimated optimum Xm can be achieved with 17.3 mM potassium nitrate and 8.9 mM urea. Under this condition an Xm of 6077 ± 199 mg/L and a PX of 341.5 ± 19.1 mg L–1day–1 were obtained.
A clinical assay for the measurement of milrinone in plasma by HPLC mass spectrometry
Authors: Chihoho B. , Sage A. B. , Smolenski R. T. , Vazir A. , Rose M. L. , Banner N. R. , Leaver N. V. 
Published: September 2011

ABSTRACTMilrinone is a bipyridine phosphodiesterase inhibitor with positive inotropic and vasodilatory effects. As interest in longer term use of intravenous therapy increases, it becomes essential to monitor its plasma concentration owing to a narrow therapeutic range, an increased half‐life in renal failure and toxicity associated with high levels. A high‐performance liquid chromatography (HPLC) method with mass (MS) detection using a triple quadrupole mass spectrometer is presented. The method was compared with the UV/HPLC method and validated according to current international guidelines. Coefficients of variation of less than 7.5% were obtained across the therapeutic range and 18.3% at 2.4 ng/mL, the lower limit of quantitation. Plasma from 13 cardiac surgery patients receiving standard intravenous doses of milrinone were measured. Eight patients achieved therapeutic milrinone levels within 3–4 h post start of infusion, one was borderline sub‐therapeutic and four patients achieved levels that were above the upper limit of the therapeutic range and potentially toxic. This method offers high sensitivity, is rapid, easy to use and requires minimal amount of sample. We believe this method could become the reference procedure for clinical monitoring of milrinone and help to improve the safety of the use of this drug in patients with cardiac failure. Copyright © 2011 John Wiley & Sons, Ltd.
Rapid and sensitive LC‐MS/MS method for quantification of lamotrigine in human plasma: application to a human pharmacokinetic study
Authors: Hotha Kishore Kumar , Kumar S.Sirish , Bharathi D. Vijaya , Venkateswarulu V. 
Published: September 2011

ABSTRACTA highly sensitive, specific and fully validated LC‐MS/MS method as per general practices of industry has been developed for estimation of lamotrigine (LAM) with 100 μL of human plasma using flucanozole as an internal standard (IS). The API‐4000 LC‐MS/MS was operated under the multiple reaction‐monitoring mode using electrospray ionization. A simple liquid–liquid extraction process was used to extract LAM and IS from human plasma. The total run time was 2.0 min and the elution of LAM and IS occurred at 1.25 and 1.45 min; this was achieved with a mobile phase consisting of 0.1% formic acid–methanol (20:40:40, v/v) at a flow rate of 0.50 mL/min on a Discovery CN (50 × 4.6 mm, 5 µm) column. The developed method was validated in human plasma with a lower limit of quantitation of 0.1 ng/mL for LAM. A linear response function was established for the range of concentrations 0.1–1500 ng/mL (r > 0.998) for LAM. The intra‐ and inter‐day precision values for LAM met the acceptance as per Food and Drug Administration guidelines. LAM was stable in the set of stability studies, viz. bench‐top, autosampler and freeze–thaw cycles. The developed assay method was applied to an oral bioequivalence study in humans. Copyright © 2011 John Wiley & Sons, Ltd.
Amyloid fibril formation from crude protein mixtures
Authors: Rao Shiva P. , Meade Susie J. , Joyce Nigel I. , Healy Jackie P. , Sutton Kevin H. , Larsen Nigel G. , Gerrard Juliet A. 
Published: September 2011

AbstractAmyloid fibrils have potential as bionanomaterials. A bottleneck in their commercial use is the cost of the highly purified protein typically needed as a starting material. Thus, an understanding of the role of heterogeneity in the mixtures from which amyloid fibrils are formed may inform production of these structures from readily available impure starting materials. Insulin, a very well understood amyloid‐forming protein, was modified by various reagents to explore whether amyloid fibrils could still form from a heterogeneous mixture of insulin derivatives. Aggregates were characterized by thioflavin T fluorescence and transmission electron microscopy. Using acetylation, reduction carboxymethylation, reduction pyridylethylation, trypsin digestion and chymotrypsin digestion, it was shown that amyloid fibrils can form from heterogeneous mixtures of modified insulin. The modifications changed both the rate of reaction and the yield of the final product, but led to fibrillar structures, some with interesting morphologies. Well defined, long, unbranched fibrils were observed in the crude reduced carboxymethylated insulin mixture and the crude reduced pyridylethylated insulin revealed the formation of “wavy” fibrils, compared with the straighter native insulin amyloid fibrils. Although trypsin digestion inhibited fibrils formation, chymotrypsin digestion of insulin produced a mixture of long and short fibrils under the same conditions. We conclude that amyloid fibrils may be successfully formed from heterogeneous mixtures and, further, that chemical modification may provide a simple means of manipulating protein fibril assembly for use in bionanotechnological applications, enabling some design of overall morphology in the bottom‐up assembly of higher order protein structures from amyloid fibrils. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Secretion of elastin‐like polypeptides with different transition temperatures by Pichia pastoris
Authors: Schipperus Roelof , Eggink Gerrit , de Wolf Frits A. 
Published: September 2011

AbstractLike natural tropoelastin, polypeptides based on an elastin‐like VPGXG repeat have a characteristic inverse temperature response, which leads to coacervate formation above a certain transition temperature and which could be useful for a variety of applications. The key advantage of elastin‐like polypeptides (ELPs) over (tropo)elastin is a full control over this temperature response by adjustment of either the amino acid composition or the chain length, according to insights provided by extensive research. Future application of ELPs will require efficient ELP production systems, and in a previous article, we described the successful use of Pichia pastoris for secreted production of an ELP, with an overall yield of ∼ 200 mg L−1. In this study, we investigated the influence of changed amino acid composition and chain length on the yield of secreted ELP. We have found that both parameters have a distinct impact on the overall yield, with higher yield for shorter and more hydrophilic ELPs. Because yield and transition temperature (Tt) thus appear to be positively correlated, we hypothesize that good solubility of ELP below the Tt promotes the secreted production and coacervate formation above Tt decreases it. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
A new aqueous biphasic system containing polypropylene glycol and a water‐miscible ionic liquid
Authors: Zafarani‐Moattar Mohammed Taghi , Hamzehzadeh Sholeh , Nasiri Saeed 
Published: September 2011

AbstractIn this work, we proposed a novel aqueous biphasic system (ABS) composed of polypropylene glycol P400 (PPG P400) and hydrophilic ionic liquids (IL), 1‐alkyl‐3‐methylimidazolium bromide (alkyl = ethyl or butyl), forming an upper polymer‐rich phase and a lower IL‐rich phase at ambient temperature. This new ABS can present interesting characteristics shared by ILs and polymers such as low volatility, good solvation ability, tunable physical properties, and high design capacity for achieving task‐specific phase components to enhance the partitioning of target species. Ternary phase diagram of the novel ABS formed by PPG 400 and [C2mim]Br in water was measured at T = 298.15 K. Factors affecting the binodal curves such as the cation side alkyl chain length and the temperature were also evaluated. The results were successfully interpreted in terms of the kosmotropic/chaotropic nature of ILs. Furthermore, the phase behavior of the PPG‐[C2mim]Br ABS is described by the NRTL model. Finally, the extraction potential of the proposed ABS was evaluated through its application to the extraction of the essential amino acids such as L‐tryptophan and L‐tyrosine. The partition coefficients here obtained demonstrated the fine potential of the proposed ABS for biomolecules separation. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Predictive tool for recombinant protein production in Escherichia coli Shake‐Flask cultures using an on‐line monitoring system
Authors: Kunze Martin , Huber Robert , Gutjahr Claudia , Müllner Stefan , Büchs Jochen 
Published: September 2011

AbstractAs Escherichia coli (E. coli) is well defined with respect to its genome and metabolism, it is a favored host organism for recombinant protein production. However, many processes for recombinant protein production run under suboptimal conditions caused by wrong or incomplete information from an improper screening procedure, because appropriate on‐line monitoring systems are still lacking. In this study, the oxygen transfer rate (OTR), determined on‐line in shake flasks by applying a respiration activity monitoring system (RAMOS) device, was used to characterize the metabolic state of the recombinant organisms. Sixteen clones of E. coli SCS1 with foreign gene sequences, encoding for different target proteins, were cultivated in an autoinduction medium, containing glucose, lactose, and glycerol, to identify relationships between respiration activity and target protein production. All 16 clones showed a remarkably different respiration activity, biomass, and protein formation under induced conditions. However, the clones could be classified into three distinct types, and correlations could be made between OTR patterns and target protein production. For two of the three types, a decrease of the target protein was observed, after the optimal harvest time had passed. The acquired knowledge was used to modify the autoinduction medium to increase the product yield. Additional 1.5 g/L glucose accelerated the production process for one clone, shifting the time point of the maximal product yield from 24 to 17 h. For another clone, lactose addition led to higher volumetric product yields, in fact 25 and 38% more recombinant protein for 2 and 6 g/L additional lactose, respectively. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Detoxification of azo dyes mediated by cell‐free supernatant culture with manganese‐dependent peroxidase activity: Effect of Mn2+ concentration and H2O2 dose
Authors: Contreras Elsa , Urra Johana , Vásquez Carlos , Palma Carolyn 
Published: September 2011

AbstractWhite‐rot fungi (WRF) are capable of degrading complex organic compounds such as lignin, and the enzymes that enable these processes can be used for the detoxification of recalcitrant organopollutants. The aim of this study is to evaluate a system based on the use of an in vitro ligninolytic enzyme for the detoxification of recalcitrant dye pollutants. The dyes selected for investigation were the anionic and cationic commercial azo dyes, basic blue 41 (BB41), acid black 1 (AB1), and reactive black 5 (RB5). A supernatant, cell‐free culture of WRF with manganese peroxidase activity was used to investigate its degradative capacity under various conditions, and concentrations of cofactors, H2O2 and Mn2+. The assays were carried out using a 22 experimental designs whose variables were concentration of Mn2+ (33 and 1,000 μM) and semicontinuous dosage of the H2O2 (0.02 and 0.10 μmol) added at a frequency of 0.2 min−1. The response variables analyzed were the efficiency and the initial rate of the decolorization process. The dye concentrations considered ranged from 10 to 200 mg L−1. AB1 and RB5 were decolorized over the entire interval of concentrations studied; reaching efficiencies between 15 and 95%. Decolorization of up to 100 mg L−1, BB41 had less than 30% efficiency. The decay of the concentration of AB1 was interpreted by two‐stage kinetics model, with the exception of the condition of 33 μM Mn2+–0.02 μmol of H2O2 in which only one stage was observed. For all assays performed with 33 μM Mn2+, the initial rate of the decolorization process was found to be dependent on the dosage of H2O2. The results of this study can be applied to the development bioreactors for the degradation of recalcitrant pollutants from the textile industry and may be used as a model for expanding the use of extracellular enzyme supernatants in bioremediation. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2012
Delineation of the Core Aggregation Sequences of TDP‐43 C‐Terminal Fragment
Authors: Saini Akash , Chauhan Virander Singh 
Published: September 2011

AbstractUbiquitinated cytoplasmic inclusions of TDP‐43 and its C‐terminal cleavage products are the pathological hallmarks of amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitinated inclusions. The C‐terminal fragments (CTFs) of TDP‐43 are increasingly considered to play an important role in its aggregation and in disease. Here, we employed a set of synthetic peptides spanning the length of the TDP‐43 CTF (220–414) in order to find out its core aggregation domains. Two regions, one in the RRM‐2 domain (246–255) and the other in the C‐terminal domain (311–320) of TDP‐43, stand out as highly aggregation prone. Studies done on recombinant purified TDP‐43 CTF and its three mutants, in which these sequences were deleted individually and together, suggested that the 311–320 region has a more crucial role to play than the 246–255 in its aggregation. The study helps in defining specific peptide sequences that might form the core of TDP‐43 aggregation. Identification of these sequences could help in designing peptide based inhibitors of TDP‐43 aggregation.
Identification of Anchor Points for Chemical Modification of a Small Cysteine‐Rich Protein by Using a Cysteine Scan
Authors: Vinther Tine N. , Ribel Ulla , Åskov Pedersen Thomas , Kjeldsen Thomas B. , Jensen Knud J. , Hubálek František 
Published: September 2011

AbstractChemical modifications of proteins are increasingly important in the development of protein drugs with fine‐tuned properties. Regioselective modification, such as the chemoselective alkylation of an unpaired cysteine residue, is a prerequisite for obtaining homogenous protein products. The introduction of an unpaired Cys into the Cys‐rich protein, insulin, was investigated by using a Cys scan. This was challenging as the introduced Cys could interfere with insulin’s three existing disulfide bonds. However, eight insulin precursors were expressed in Saccharomyces cerevisiae with good yields. Although extensive post‐translational modifications of the unpaired Cys were observed, the majority could be removed by selective reduction. An example Cys7 insulin analogue was modified with a PEGylated maleimide moiety. The new variant was active in in vitro and in vivo models. Our results show that even small Cys‐rich proteins can be expressed with additional unpaired Cys in meaningful yields and further chemically modified, while maintaining their biological activity.
Autoinductive Exponential Signal Amplification: A Diagnostic Probe for Direct Detection of Fluoride
Authors: Perry‐Feigenbaum Rotem , Sella Eran , Shabat Doron 
Published: September 2011

AbstractA new example of an exponential signal amplification strategy for the direct detection of fluoride is demonstrated. The amplification occurred through reaction of fluoride with a responsive chromogenic probe. The probe activity is based on a unique dendritic chain reaction that generates a fluoride anion, which is the analyte of interest, during the disassembly pathway of the dendritic probe. This autoinductive amplification mechanism may be applied for detection of other analytes by coupling activity of a modified probe with that of the fluoride amplifier.
Proton‐Coupled Electron Transfer Originating from Excited States of Luminescent Transition‐Metal Complexes
Authors: Wenger Oliver S. 
Published: September 2011

AbstractProton‐coupled electron transfer (PCET) is of fundamental importance for small‐molecule activation processes, such as water splitting, CO2‐reduction, or nitrogen fixation. Ideally, energy‐rich molecules such as H2, CH3OH, or NH3 could be generated artificially using (solar) light as an energy input. In this context, PCETs originating directly from electronically excited states play a crucial role. A variety of transition‐metal complexes have been used recently for fundamental investigations of this important class of reactions, and the key findings of these studies are reviewed in this article. The present minireview differs from other reviews on the subject of PCET in that it focuses specifically on reactions occurring directly from electronically excited states.
ChemInform Abstract: Effects of Pr Doping on Thermoelectric Transport Properties of Ca3‐xPrxCo4O9.
Authors: Zhang F. P. , Zhang X. , Lu Q. M. , Zhang J. X. , Liu Y. Q. , Zhang G. Z. 
Published: September 2011

AbstractPowders of the title compounds with x = 0, 0.05, 0.1, 0.2, and 0.3 are prepared by the sol—gel method starting with stoichiometric amounts of Ca(NO3)2, Pr(NO3)3, and Co(NO3)2 dissolved in aqueous citric acid solution (heating of the obtained gel at 1073 K for 8 h).
ChemInform Abstract: Emergence of Superconductivity in “32522” Structure of (Ca3Al2O5‐y)(Fe2Pn2) (Pn: As and P).
Authors: Shirage Parasharam M. , Kihou Kunihiro , Lee Chul‐Ho , Kito Hijiri , Eisaki Hiroshi , Iyo Akira 
Published: September 2011

AbstractPolycrystalline samples of the title compounds are prepared from mixtures of CaO, Fe, Al, Fe2O3, and As or P (4.5 GPa, 1150 °C for Pn: As and 1300 °C for Pn: P, 1 h).
ChemInform Abstract: Layered LixMoO2 Phases with Different Composition for Electrochemical Application: Structural Considerations.
Authors: Mikhailova D. , Bramnik N. N. , Bramnik K. G. , Reichel P. , Oswald S. , Senyshyn A. , Trots D. M. , Ehrenberg H. 
Published: September 2011

AbstractLi1.0MoO2 (I), Li0.91MoO2 (II), and Li0.75MoO2 (III) are synthesized by solid state reactions of stoichiometric mixtures of Li2MoO4, Mo, and MoO3 (alumina crucibles, 1223 K, 20 h) and characterized by single crystal XRD, powder XRD, XPS, and electrochemical measurements.
ChemInform Abstract: Stabilizing Low‐Valent Refractory Metals in a Strongly Oxidizing Medium: The First Molybdenum(V) Sulfate ‐ MoO(HSO4)(SO4) ‐ From Mo(CO)6 in Oleum.
Authors: Betke Ulf , Neuschulz Kai , Wickleder Mathias S. 
Published: September 2011

AbstractDeep‐blue single crystals of MoO(HSO4)(SO4) are prepared from Mo(CO)6 in oleum (sealed glass ampule, 200 °C, 2 d).
ChemInform Abstract: Toward a Reliable Synthesis of Strontium Ruthenate: Parameter Control and Property Investigation of Submicrometer‐Sized Structures.
Authors: Tiano Amanda L. , Santulli Alexander C. , Koenigsmann Christopher , Feygenson Mikhail , Aronson M. C. , Harrington Richard , Parise John B. , Wong Stanislaus S. 
Published: September 2011

AbstractSingle‐crystalline SrRuO3 submicrometer‐sized particles are synthesized by reaction of Sr(OH)2·8H2O, RuO2 nanoparticles, and 1% mineral oil in Triton X‐100 surfactant in a NaCl/KCl flux (porcelain crucible, air, 700 °C; quenching).
ChemInform Abstract: Synthesis and Characterization of [PW11O39Ir(H2O)]4‐: Successful Incorporation of Ir into Polyoxometalate Framework and Study of the Substitutional Lability at the Ir(III) Site.
Authors: Sokolov Maxim N. , Adonin Sergey A. , Mainichev Dmitry A. , Vicent Cristian , Zakharchuk Nina F. , Danilenko Andrey M. , Fedin Vladimir P. 
Published: September 2011

AbstractTitle compound (III) is synthesized from two different polytungstate precursors and characterized by XRD, 31P and 183W NMR, ESI‐mass spectrometry, and cyclic voltammetry.
ChemInform Abstract: A Highly Recyclable Magnetic Core‐Shell Nanoparticle‐Supported TEMPO Catalyst for Efficient Metal‐ and Halogen‐Free Aerobic Oxidation of Alcohols in Water.
Authors: Karimi Babak , Farhangi Elham 
Published: September 2011

AbstractThe highly efficient heterogeneous catalyst is used for the aerobic oxidation of primary, secondary, allylic, and even sterically hindered alcohols in water.
ChemInform Abstract: Ruthenium‐Catalyzed Regio‐ and Enantioselective Allylic Substitution with Water: Direct Synthesis of Chiral Allylic Alcohols.
Authors: Kanbayashi Naoya , Onitsuka Kiyotaka 
Published: September 2011

AbstractThe simplicity and availability of the nucleophile, the mild conditions, and the broad scope of the allylic chlorides are features of the present reaction.
ChemInform Abstract: Nickel‐Catalyzed Cross‐Coupling of Aryl Bromides with Tertiary Grignard Reagents Utilizing Donor‐Functionalized N‐Heterocyclic Carbenes (NHCs).
Authors: Lohre Claudia , Droege Thomas , Wang Congyang , Glorius Frank 
Published: September 2011

AbstractThe Kumada cross‐coupling of tertiary alkyl Grignard reagents with aryl bromides provides a selective access to highly substituted alkylbenzene derivatives.