bluuebunny/crossref_metadata_2025_split huggingface dataset:
Thermal and dynamic mechanical properties of vitamin E infused and blended ultra‐high molecular weight polyethylenes
Authors: Puértolas J. A. , Martínez‐Morlanes M. J. , Mariscal M. D. , Medel F. J. 
Published: December 2010

AbstractVitamin E (or α‐tocopherol) is an alternative via to thermal treatments to achieve oxidative stability of gamma or electron beam irradiated ultra‐high molecular weight polyethylenes (UHMWPE) used in total joint replacements. Our aim was to study the effects of vitamin E on the molecular dynamics and microstructural properties of UHMWPE. We hypothesized that the antioxidant would plasticize UHMWPE. Vitamin E was incorporated into UHMWPE at different concentrations by diffusion and blending and detected by ultraviolet and infrared spectroscopies from 500 ppm and 4000 ppm, respectively. Dynamic mechanical thermal analysis was used to characterize the influence of this antioxidant in the relaxations of the raw material. Differential scanning calorimetry and transmission electron microscopy served to characterize thermal and microstructure properties, respectively. Vitamin E concentrations above 3% by weight significantly reduced the degree of crystallinity and increased the melting transition temperature of raw UHMWPE. The presence of increasing concentrations of α‐tocopherol introduced and/or strengthened the beta relaxation, which was also shifted toward gradually lower temperatures and had rising activation energies up to 188 kJ/mol. In addition, the gamma relaxation remained unaltered on vitamin E addition. Therefore, no plasticizing effects of vitamin E on the molecular dynamics of UHMWPE could be confirmed from mechanical spectroscopy data. However, the α relaxation was modified in intensity and location due to the changes in the degree of crystallinity introduced by the incorporation of vitamin E. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
A Lattice‐Engineering Route to Heterostructured Functional Nanohybrids
Authors: Paek Seung‐Min , Oh Jae‐Min , Choy Jin‐Ho 
Published: December 2010

AbstractThe fabrication of layered nanomaterials, such as inorganic–inorganic, organic–inorganic, and bioinorganic nanohybrids has been demonstrated through controlled lattice engineering techniques including intercalation, exfoliation–reassembling, and pillaring reactions. Such a lattice engineering method gives rise to an almost unlimited set of new hybrid compounds with a large spectrum of desirable properties. Due to the unique two‐dimensional structures and properties, various kinds of functional nanohybrid materials can be utilized as photocatalysts, electrode materials, superconducting thin films, gas separation membranes, drug‐delivery systems, and biomolecule reservoirs.
An improved delay‐dependent bounded real lemma (BRL) and H∞ controller synthesis for linear neutral systems
Authors: Parlakçi Mehmet Nur Alpaslan 
Published: December 2010

AbstractIn this paper, a novel delay‐dependent bounded real criterion and an improved sufficient condition are derived for the design of an H∞ state‐feedback controller for linear neutral time‐delay systems. On the basis of an augmented Lyapunov‐Krasovskii functional, a new bounded real lemma is introduced in terms of a convex linear matrix inequality (LMI) condition that can be solved using interior point algorithms. The bounded real lemma is extended to obtain a sufficient condition for the existence of a delay‐dependent H∞ memoryless state‐feedback controller. Neither any model transformation nor bounding of any of the cross terms are utilized while deriving the bounded real lemma. Moreover, the use of any free slack matrix variable approach is avoided to a certain extent in order not to increase the complexity of the synthesis problem. A cone complementary nonlinear minimization algorithm is employed to achieve a feasible solution set for the synthesis conditions. Finally, seven numerical examples are given to illustrate the effectiveness of the proposed method.Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Non‐random autosome segregation: A stepping stone for the evolution of sex chromosome complexes?
Authors: Schwander Tanja , Beukeboom Leo W. 
Published: December 2010

AbstractA new study in Caenorhabditis elegans shows that homologous autosomes segregate non‐randomly with the sex chromosome in the heterogametic sex. Segregation occurs according to size, small autosomes segregating with, and large autosomes segregating away from the X‐chromosome. Such sex‐biased transmission of autosomes could facilitate the spread of sexually antagonistic alleles whose effects favor the fitness of one sex at the expense of the other. This may provide a first step toward the evolution of new sex determination systems.
Bioengineering of microorganisms for C3 to C5 alcohols production
Authors: Mainguet Samuel E. , Liao James C. 
Published: December 2010

AbstractProduction of renewable fuels and chemicals is an absolute requirement for the sustainability of societies. This fact has been neglected during the past century as cheap and abundant, yet not renewable, sources of hydrocarbons were available. Since fossil fuel availability is decreasing, biological production of fuels and chemicals has been proposed to be a potential alternative to fossil sources. Higher alcohols (from C3 to C5) are useful substitutes for gasoline because of their high energy density and low hygroscopicity and are important feedstocks for other chemicals. Some Clostridia species are known to naturally ferment sugars to isopropanol and 1‐butanol. However, other C3 to C5 alcohols are not produced in large quantities by natural microorganisms. A non‐fermentative strategy to produce a broad range of higher alcohols has been devised using the ubiquitous keto acid biosynthetic pathways. This review provides a current overview of these different strategies.
A highly sensitive LC‐MS/MS method for the determination of S‐raclopride in rat plasma: application to a pharmacokinetic study in rats
Authors: Punde Suresh P. S, Ravindra Ramachandra , Gupta Manish , Dixit Abhishek , Giri Sanjeev , Rajagopal Sriram , Mullangi Ramesh 
Published: December 2010

AbstractA highly sensitive and rapid assay method has been developed and validated for the estimation of S‐(−)‐raclopride (S‐RCP) in rat plasma with liquid chromatography coupled to tandem mass spectrometry with electrospray ionization in the positive ion mode. The assay procedure involves a simple liquid–liquid extraction technique for extraction of S‐RCP and phenacetin (internal standard, IS) from rat plasma. Chromatographic separation was achieved with 0.2% formic acid : acetonitrile (80:20, v/v) at a flow rate of 0.30 mL/min on a Phenomenex Prodigy C18 column with a total run time of 4.5 min. The MS/MS ion transitions monitored were 347.2 → 112.1 for S‐RCP and 180.1 → 110.1 for IS. Method validation and pre‐clinical sample analysis were performed as per FDA guidelines and the results met the acceptance criteria. The lower limit of quantitation achieved was 0.05 ng/mL and the linearity range was extended from 0.05 to 152 ng/mL in rat plasma. The intra‐day and inter‐day precisions were 0.23–10.5 and 3.74–7.29%, respectively. This novel method was applied to a pharmacokinetic study of S‐RCP in rats. Copyright © 2010 John Wiley & Sons, Ltd.
A rapid and sensitive LC‐MS/MS method for quantification of donepezil and its active metabolite, 6‐o‐desmethyl donepezil in human plasma and its pharmacokinetic application
Authors: Pilli Nageswara Rao , Inamadugu Jaswanth Kumar , Kondreddy Neeraja , Karra Vijaya Kumari , Damaramadugu Rajasekhar , Rao J. V. L. N Seshagiri 
Published: December 2010

AbstractA rapid and sensitive liquid chromatography–tandem mass spectrometric (LC‐MS/MS) assay method has been developed and fully validated for simultaneous quantification of donepezil and its active metabolite, 6‐o‐desmethyl donepezil in human plasma. Analytes and the internal standard were extracted from human plasma by liquid–liquid extraction technique using a 30:70 v/v mixture of ethyl acetate andn‐hexane. The reconstituted samples were chromatographed on a C18column by using a 70:30 v/v mixture of acetonitrile and ammonium formate (5 mm, pH 5.0) as the mobile phase at a flow rate of 0.6 mL/min. The calibration curve obtained was linear (r≥ 0.99) over the concentration range of 0.09–24.2 ng/mL for donepezil and 0.03–8.13 ng/mL for 6‐o‐desmethyl donepezil. The results of the intra‐day and inter‐day precision and accuracy studies were well within the acceptable limits. The proposed method was successfully applied for the estimation of the drug in real time plasma samples for pharmacokinetic studies. Copyright © 2010 John Wiley & Sons, Ltd.
Validation of a bioanalytical method for the quantification of a therapeutic peptide, ramoplanin, in human dried blood spots using LC‐MS/MS
Authors: Ewles Matthew F. , Turpin Phillip E. , Goodwin Lee , Bakes David M. 
Published: December 2010

AbstractA method has been developed and validated for the quantification of ramoplanin, a 2554 Da peptide antibiotic, in human dried blood spots using high‐performance liquid chromatography with tandem mass spectrometric detection. The validation data meet FDA acceptance criteria for bioanalytical assays and cover the quantification of ramoplanin over the range 10–5000 ng/mL. The assay determines ramoplanin at the same lower limit of quantification as conventional liquid sample methods. Dried blood spot analysis provides an approach for quantification of peptide therapeutics and delivers significant benefits for sample collection and handling and also sample cleanup over conventional plasma and serum assays. Copyright © 2010 John Wiley & Sons, Ltd.
Recent advances in sample preparation techniques for effective bioanalytical methods
Authors: Kole Prashant Laxman , Venkatesh Gantala , Kotecha Jignesh , Sheshala Ravi 
Published: December 2010

AbstractThis paper reviews the recent developments in bioanalysis sample preparation techniques and gives an update on basic principles, theory, applications and possibilities for automation, and a comparative discussion on the advantages and limitation of each technique. Conventional liquid–liquid extraction (LLE), protein precipitation (PP) and solid‐phase extraction (SPE) techniques are now been considered as methods of the past. The last decade has witnessed a rapid development of novel sample preparation techniques in bioanalysis. Developments in SPE techniques such as selective sorbents and in the overall approach to SPE, such as hybrid SPE and molecularly imprinted polymer SPE, have been addressed. Considerable literature has been published in the area of solid‐phase micro‐extraction and its different versions, e.g. stir bar sorptive extraction, and their application in the development of selective and sensitive bioanalytical methods. Techniques such as dispersive solid‐phase extraction, disposable pipette extraction and micro‐extraction by packed sorbent offer a variety of extraction phases and provide unique advantages to bioanalytical methods. On‐line SPE utilizing column‐switching techniques is rapidly gaining acceptance in bioanalytical applications. PP sample preparation techniques such as PP filter plates/tubes offer many advantages like removal of phospholipids and proteins in plasma/serum. Newer approaches to conventional LLE techniques (salting‐out LLE) are also covered in this review article. Copyright © 2010 John Wiley & Sons, Ltd.
A new method for quantitative determination of two uronic acids by CZE with direct UV detection
Authors: Xia Yong‐gang , Liang Jun , Yang Bing‐you , Wang Qiu‐hong , Kuang Hai‐xue 
Published: December 2010

AbstractA new method using capillary zone electrophoresis was developed for the rapid quantification of two common uronic acids, galacturonic acid and glucuronic acid, based on utilization of an alkaline background electrolyte with reversed electroosmotic flow (EOF) within 16 min. The method relies on in‐capillary reaction and direct UV detection at the wavelength 270 nm. The optimum electrolyte solution was prepared of 130 mm sodium hydroxide, 36 mm disodium hydrogen phosphate dihydrate and 0.5 mm cetyltrimethylammonium bromide. EOF was reversed to detect uronic acids and to improve the separation of neutral sugars. The established method was validated and the results showed good linearity, high precision and satisfactory sensitivity. The newly developed method was successfully applied to analyze galacturonic acid and glucuronic acid content in Forsythia suspensa polysaccharides. The method is fast since only sample hydrolysis and dilution are required in the sample preparation. Copyright © 2010 John Wiley & Sons, Ltd.
LC‐MS in analytical toxicology: some practical considerations
Authors: Couchman Lewis , Morgan Phillip E. 
Published: December 2010

AbstractLiquid chromatography, coupled with single‐stage or tandem mass spectrometry, is a powerful tool increasingly used in analytical toxicology. However, the atmospheric pressure ionization processes involved are complex, and subject to interference from matrix components, for example. Further, the techniques used in sample preparation, chromatography and mass analysis are developing rapidly. An understanding of the advantages and limitations of LC‐MS ensures appropriate analyses are performed, and that reliable results are generated. Consideration should be given to the influence of the sample preparation and chromatographic conditions on the ionization of the analyte at the mass spectrometer interface. This review aims to provide some practical guidance and examples to aid method development for commonly encountered analytes in analytical toxicology. Copyright © 2010 John Wiley & Sons, Ltd.
Analysis of acetylcholinesterase inhibitors: bioanalysis, degradation and metabolism
Authors: Azevedo Marques Lygia , Giera Martin , Lingeman Henk , Niessen Wilfried MA 
Published: December 2010

AbstractAlzheimer's is a neurodegenerative disease. Its symptoms are attributed to a deficiency of cholinergic neurotransmission. The drugs of choice for the treatment of Alzheimer's disease are acetylcholinesterase (AChE) inhibitors. Starting in the 1980's from non‐specific AChE inhibitors, the first‐generation drugs such as physostigmine, a second generation of more selective and better tolerated products has been developed. Methods to detect and quantify these drugs and their metabolites in biological samples have been developed for analysis in plasma, blood, urine and cerebrospinal fluid. Diverse detection techniques have been used, such as ultraviolet, fluorescence, electrochemical and mass spectrometry. In this review, the methods applied to the analysis of these drugs and their metabolites in different biological matrices are reviewed and discussed. The stability of these drugs in biological matrices and under stress‐conditions is also included in the discussion. Copyright © 2010 John Wiley & Sons, Ltd.
Variable selection in regression—a tutorial
Authors: Andersen C. M. , Bro R. 
Published: December 2010

AbstractThis paper provides a practical guide to variable selection in chemometrics with a focus on regression‐based calibration models. Several approaches, such as genetic algorithms (GAs), jack‐knifing, forward selection, etc., are explained; it is also explained how to choose between different kinds of variable selection methods. The emphasis in this paper is on how to use variable selection in practice and avoid the most common pitfalls. Copyright © 2010 John Wiley & Sons, Ltd.
A Thermosensitive Monolithic Column as an Artificial Antibody for the On‐line Selective Separation of the Protein
Authors: Qin Lei , He Xi‐Wen , Jia Man , Li Wen‐You , Zhang Yu‐Kui 
Published: December 2010

AbstractThe main objective of this study was to develop a new methodology for the preparation of a protein (antigen) that is a molecularly imprinted polymer (MIP, an artificial antibody) modified onto the surface of a silica skeleton in which the resulting stationary phase is thermosensitive. The silica monolithic skeleton with vinyl groups was synthesized in a stainless‐steel column by using a mild one‐step sol–gel process with two types of precursor: methyltrimethoxysilane (MTMS) and γ‐methacryloxypropyltrimethoxysilane (γ‐MAPS). Subsequently, three types of the thermosensitive protein MIP were anchored onto the surface of the silica skeleton to prepare the MIP monoliths, which were systematically investigated for back pressure and separation ability at different temperatures to establish good imprinting conditions. Under the optimized imprinting conditions, the chromatographic behavior of the thermosensitive MIP monolith exhibited strong retention ability for the lysozyme template (target antigen) in relation to the nonimprinting monolith (NIP monolith). The imprinting factor (IF) for lysozyme reached 3.48 at 20 °C. Moreover, this new type of artificial antibody displayed favorable binding characteristics for lysozyme over competitive proteins and was further evaluated to selectively separate lysozyme in a real sample by using an on‐line method. The run‐to‐run and column‐to‐column repeatability measurements of the thermosensitive MIP monoliths were also satisfactory.
Structural Design of Easy‐Axis Magnetic Anisotropy and Determination of Anisotropic Parameters of LnIIICuII Single‐Molecule Magnets
Authors: Kajiwara Takashi , Nakano Motohiro , Takahashi Kohei , Takaishi Shinya , Yamashita Masahiro 
Published: December 2010

AbstractFour dinuclear LnIIICuII complexes with Ln=Tb (1), Dy (2), Ho (3), and Er (4) were synthesized to investigate the relationship between their respective magnetic anisotropies and ligand‐field geometries. These complexes were crystallographically isostructural, and a uni‐axial ligand field was achieved by using three phenoxo oxygen groups. Complexes 1 and 2 displayed typical single‐molecule magnet (SMM) behaviors, of which the out‐of‐phase susceptibilities were observed in the temperature range of 1.8–5.0 K (1) and 1.8–20.0 K (2). The Cole–Cole plots exhibited a semicircular shape with α parameters in the range of 0.08–0.18 (2.6–4.0 K) and 0.07–0.24 (3.5–7.0 K). The energy barriers Δ/kB were estimated from the Arrhenius plots to be 32.9(4) K for 1 and 26.0(5) K for 2. Complex 3 displayed a slow magnetic relaxation below 3.0 K, whereas complex 4 did not show any frequency‐dependent behavior for both in‐phase and out‐of‐phase susceptibilities, which indicates that easy‐axis anisotropy was absent. The temperature dependence of the dc susceptibilities for the field‐aligned samples of 1–3 revealed that the χMT value continuously increased as the temperature was lowered, which indicates the presence of low‐lying Stark sublevels with the highest |Jz| values. In contrast, complex 4 displayed a smaller and temperature‐independent χMT value, which also indicates that easy‐axis anisotropy was absent. Simultaneous analyses were carried out for 1–3 to determine the magnetic anisotropy parameters on the basis of the Hamiltonian that considers B20, B40, and B60.
Stereoselective Total Synthesis of (−)‐Spirofungin A by Utilising Hydrogen‐Bond Controlled Spiroketalisation
Authors: Lynch John E. , Zanatta Shannon D. , White Jonathan M. , Rizzacasa Mark A. 
Published: December 2010

AbstractThe stereoselective total synthesis of the spiroketal containing Streptomyces metabolite (−)‐spirofungin A (1) is described. A key step involved a spiroketalisation controlled by an intramolecular H‐bond which favoured the desired spiroketal 4 (13:1 ratio). The presence of the intramolecular H‐bond in 4 is possibly due to a 1,5‐alkyne–oxygen interaction. Other key steps include an efficient cross‐metathesis to form the spiroketal precursor, a tin mediated syn‐aldol reaction and a Stille cross‐coupling reaction to create the C22C23 bond. A final Wittig extension followed by deprotection gave (−)‐spirofungin A (1).
Differentiating a Diverse Range of Volatile Organic Compounds with Polyfluorophore Sensors Built on a DNA Scaffold
Authors: Samain Florent , Dai Nan , Kool Eric T. 
Published: December 2010

AbstractOligodeoxyfluorosides (ODFs) are short DNA‐like oligomers in which DNA bases are replaced with fluorophores. A preliminary study reported that some sequences of ODFs were able to respond to a few organic small molecules in the vapor phase, giving a change in fluorescence. Here, we follow up on this finding by investigating a larger range of volatile organic analytes, and a considerably larger set of sensors. A library of tetramer ODFs of 2401 different sequences was prepared by using combinatorial methods, and was screened in air for fluorescence responses to a set of ten different volatile organics, including multiple aromatic and aliphatic compounds, acids and bases, varied functional groups, and closely related structures. Nineteen responding sensors were selected and characterized. These sensors were cross‐screened against all ten analytes, and responses were measured qualitatively (by changes in color and intensity) and quantitatively (by measuring ΔR, ΔG, and ΔB values averaged over five to six sensor beads; R=red, G=green, B=blue). The results show that sensor responses were diverse, with a single sensor responding differently to as many as eight of the ten analytes; multiple classes of responses were seen, including quenching, lighting‐up, and varied shifts in wavelength. Responses were strong, with raw ΔR, ΔG, and ΔB values of as high as >200 on a 256‐unit scale and unamplified changes in many cases apparent to the naked eye. Sensors were identified that could distinguish clearly between even very closely related compounds such as acrolein and acrylonitrile. Statistical methods were applied to select a small set of four sensors that, as a pattern response, could distinguish between all ten analytes with high confidence. Sequence analysis of the full set of sensors suggested that sequence/order of the monomer components, and not merely composition, was highly important in the responses.
Retracted: The Effect of Early and Intensive Statin Therapy on Ventricular Premature Beat or Nonsustained Ventricular Tachycardia in Patients With Acute Coronary Syndrome
Authors: He Xian‐Zhi , Zhou Sheng‐Hua , Wan Xin‐Hong , Wang Hai‐Yu , Zhong Qing‐Hua , Xue Jian‐Fang 
Published: December 2010

AbstractRetractionThe following article from Clinical Cardiology, “The Effect of Early and Intensive Statin Therapy on Ventricular Premature Beat or Nonsustained Ventricular Tachycardia in Patients With Acute Coronary Syndrome,”1 by Xian‐Zhi He, MD; Sheng‐Hua Zhou, MD; Xin‐Hong Wan, MD; Hai‐Yu Wang, MD; Qing‐Hua Zhong, MD; and Jian‐Fang Xue, MD, published online on December 10, 2010 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor‐in‐Chief, Dr. A.J. Camm, and Wiley Periodicals, Inc. The retraction has been agreed due to significant overlap with a similar article2 previously published by the same authors in the Cardiology Journal.References1. He X.‐Z., Zhou S.‐H., Wan X.‐H., Wang H.‐Y., Zhong Q.‐H. and Xue J.‐F. The effect of early and intensive statin therapy on ventricular premature beat or nonsustained ventricular tachycardia in patients with acute coronary syndrome. Clin Cardiol. 34(1):59–63. doi: 10.1002/clc.208182. He XZ, Zhou SH, Wan XH, Wang HY, Zhong QH, Xue JF. The effect of early and intensive statin therapy on ventricular premature beat or non‐sustained ventricular tachycardia in patients with acute coronary syndrome. Cardiol J. 2010;17(4):381–385.The authors have no funding, financial relationships, or conflicts of interest to disclose.