bluuebunny/crossref_metadata_2025_split huggingface dataset:
Graphical approaches for multiple comparison procedures using weighted Bonferroni, Simes, or parametric tests
Authors: Bretz Frank , Posch Martin , Glimm Ekkehard , Klinglmueller Florian , Maurer Willi , Rohmeyer Kornelius 
Published: August 2011

AbstractThe confirmatory analysis of pre‐specified multiple hypotheses has become common in pivotal clinical trials. In the recent past multiple test procedures have been developed that reflect the relative importance of different study objectives, such as fixed sequence, fallback, and gatekeeping procedures. In addition, graphical approaches have been proposed that facilitate the visualization and communication of Bonferroni‐based closed test procedures for common multiple test problems, such as comparing several treatments with a control, assessing the benefit of a new drug for more than one endpoint, combined non‐inferiority and superiority testing, or testing a treatment at different dose levels in an overall and a subpopulation. In this paper, we focus on extended graphical approaches by dissociating the underlying weighting strategy from the employed test procedure. This allows one to first derive suitable weighting strategies that reflect the given study objectives and subsequently apply appropriate test procedures, such as weighted Bonferroni tests, weighted parametric tests accounting for the correlation between the test statistics, or weighted Simes tests. We illustrate the extended graphical approaches with several examples. In addition, we describe briefly the gMCP package in R, which implements some of the methods described in this paper.
A liquid chromatography–tandem mass spectrometry method for the quantitative determination of diastereomers of a phosphoramidate nucleotide prodrug (PSI‐7851) in human plasma
Authors: Bao Donghui , Ross Bruce S. , Sofia Michael J. 
Published: August 2011

ABSTRACTA rapid and stereospecific method using high performance liquid chromatography–tandem mass spectrometry (HPLC‐MS/MS) for the separation and determination of PSI‐7851 diastereomers in human K2EDTA plasma has been developed. The analytical method involves direct protein precipitation with acetonitrile, followed by separation of the diastereomers on a Luna C18 column, positive mode electrospray ionization and selected reaction monitoring mode mass spectrometry detection. The mobile phase composition and pH were investigated for the resolution of the two diastereomers of PSI‐7851. The optimized method showed good resolution (Rs = 4.8) within short analysis time (approximately 8 min). The assay range was 5–2500 ng/mL for both diastereomers using a 1/x2 weighted linear regression analysis for standard curve fitting. Replicate sample analysis indicated that intra‐ and inter‐day accuracy and precision were within ±15.0%. The recovery of diastereomers from human plasma was greater than 85% and no significant matrix effect was observed. The method was demonstrated to be sensitive, selective and robust, and was successfully used to support clinical studies. Copyright © 2011 John Wiley & Sons, Ltd.
Sensitive determination of d‐lactic acid and l‐lactic acid in urine by high‐performance liquid chromatography–tandem mass spectrometry
Authors: Henry H. , Marmy Conus N. , Steenhout P. , Béguin A. , Boulat O. 
Published: August 2011

ABSTRACTd‐Lactic acid in urine originates mainly from bacterial production in the intestinal tract. Increased d‐lactate excretion as observed in patients affected by short bowel syndrome or necrotizing enterocolitis reflects d‐lactic overproduction. Therefore, there is a need for a reliable and sensitive method able to detect d‐lactic acid even at subclinical elevation levels. A new and highly sensitive method for the simultaneous determination of l‐ and d‐lactic acid by a two‐step procedure has been developed. This method is based on the concentration of lactic acid enantiomers from urine by supported liquid extraction followed by high‐performance liquid chromatography–tandem mass spectrometry. The separation was achieved by the use of an Astec Chirobiotic™ R chiral column under isocratic conditions. The calibration curves were linear over the ranges of 2–400 and 0.5–100 µmol/L respectively for l‐ and d‐lactic acid. The limit of detection of d‐lactic acid was 0.125 µmol/L and its limit of quantification was 0.5 µmol/L. The overall accuracy and precision were well within 10% of the nominal values. The developed method is suitable for production of reference values in children and could be applied for accurate routine analysis. Copyright © 2011 John Wiley & Sons, Ltd.
Anion‐exchange HPLC separation of five major rabbit lipoproteins using a nonporous diethylaminoethyl‐ligated gel with a perchlorate‐containing eluent
Authors: Hirowatari Yuji , Kon Mika , Shimura Yuko , Hirayama Satoshi , Miida Takashi 
Published: August 2011

ABSTRACTRabbits are often used as experimental animals in studies of atherosclerosis and hyperlipidemia. Although rabbit lipoproteins can be quantitated by sequential ultracentrifugation, a simpler and more reproducible method is desirable for detailed analyses. The current study describes a method to analyze rabbit lipoproteins in plasma by anion‐exchange high‐performance liquid chromatography using a column filled with nonporous, diethylaminoethyl‐ligated polymers. A solution of NaClO4 was used to adjust the ionic strength of the eluent. The method required only 15 μL of plasma and analysis was completed in 23 min. Five lipoprotein fractions (high‐density lipoprotein, low‐density lipoprotein, intermediate‐density lipoprotein, very‐low‐density lipoprotein and chylomicrons) were eluted with step‐wise increases in a concentration of NaClO4. The post‐column eluate was reacted with an enzymatic reagent to determine total cholesterol, and the lipoprotein‐cholesterol fraction was calculated according to relative peak areas in the chromatogram. The within‐day and between‐day assay coefficients of variation for lipoprotein cholesterol levels ranged between 0.436 and 7.143% and between 2.905 and 10.526%, respectively. Administering a high‐fat diet increased lipoprotein‐cholesterol concentrations by 6‐ to 77‐fold. The method described here was nevertheless able to quantitate levels of lipoprotein‐cholesterol in plasma samples from these rabbits. These results indicate that this method may be applied to lipoprotein studies using hyperlipidemic rabbit models. Copyright © 2011 John Wiley & Sons, Ltd.
Preparation and application of methylcalix[4]resorcinarene‐bonded silica particles as chiral stationary phase in high‐performance liquid chromatography
Authors: Tan Huey Min , Soh Shu Fang , Zhao Jia , Yong E. L. , Gong Yinhan 
Published: August 2011

AbstractTwo new types of methylcalix[4]resorcinarene‐bonded stationary phases, (3‐(C‐methylcalix[4]resorcinarene)‐2‐hydroxypropoxy)‐propylsilyl‐appended silica particles (MCR‐HPS) and bromoacetate‐substituted MCR‐HPS particles (BAMCR‐HPS), have been synthesized and used as chiral stationary phases for high‐performance liquid chromatography (HPLC) for the first time. The synthetic stationary phases are characterized by means of elemental analysis and Fourier‐transform infrared spectroscopy. The chromatographic behavior of MCR‐HPS and BAMCR‐HPS was studied with several disubstituted benzenes and some chiral drug compounds under both normal phase and reversed‐phase conditions. The results show that MCR‐HPS has excellent selectivity for the separation of aromatic positional isomers and BAMCR‐HPS exhibits excellent performance for separation of enantiomers of chiral compounds. Chirality, 2011. © 2011 Wiley Periodicals, Inc.
Sustainable Energy Supply by Absorption Chillers and Heat Pumps Using Multifunctional Working Pairs
Authors: Schneider Marc‐Christoph , Seiler Matthias 
Published: August 2011

AbstractEnergieeffiziente Technologien zum Kühlen und Heizen stellen eine wichtige Säule der Megatrends Ressourceneffizienz und Technologieglobalisierung dar. Insbesondere Kühl‐ und Heizkreisläufe, die nicht auf konventionell erzeugter, elektrischer Energie basieren, sondern mit erneuerbaren Energien oder mit Abwärme direkt betrieben werden, erlauben Herausforderungen wie die nachhaltige Kälte‐ und Wärmebereitstellung im industriellen oder häuslichen Bereich mit einem deutlich reduzierten CO2‐Beitrag zu adressieren. Absorptionskältemaschinen oder ‐wärmepumpen stellen in diesem Zusammenhang eine vielversprechende Technologie dar. Allerdings verhindern gegenwärtig arbeitsstoffpaarbezogene Nachteile wie Kristallisation, Korrosion oder Instabilität eine höhere Marktdurchdringung. Im Rahmen des vorliegenden Beitrags wird das Potenzial neuer Arbeitsstoffpaare auf Basis ionischer Flüssigkeiten diskutiert. Anhand ausgewählter Arbeitsstoffpaareigenschaften wird konzeptionell gezeigt, dass die Verwendung ionischer Flüssigkeiten eine Eliminierung oder Reduzierung mehrerer Nachteile des Stands der Technik und damit einen leichteren Zugang zu bisher nur unzureichend genutzten energetischen Potenzialen erlaubt.
Construction Kit for the Solvent Selection in Homogeneous Catalyzed Reactions
Authors: Behr Arno , Wintzer A. 
Published: August 2011

AbstractDie Wahl des richtigen Lösungsmittels ist in der chemischen Synthese vielfach die Basis für eine erfolgreiche großtechnische Umsetzung. Vor allem in homogenen übergangsmetallkatalysierten Reaktionen kann das Lösungsmittel der limitierende Faktor in Fragestellungen des Katalysatorrecyclings und der Produktabtrennung sein. In diesem Beitrag wird vorgestellt, welche Lösungsmittel prinzipiell für chemische Synthesen zur Verfügung stehen und welche Werkzeuge zur Auswahl eines geeigneten Lösungsmittels genutzt werden können. Dabei wird auch ein Blick auf neue Lösungsmittel geworfen, mögliche Konzepte eines Katalysatorrecyclings erläutert und auf die Diskussion des Begriffes der grünen Lösungsmittel eingegangen.
Dewatering of Ionic Liquids in a Falling Film Evaporator
Authors: Wellner Niels , Siebeneck Karl , Ramunno Monique , Wasserscheid Peter , Scholl Stephan 
Published: August 2011

AbstractDie Entwässerung ionischer Flüssigkeiten (IL) wurde in einem Einrohr‐Metallfallfilmverdampfer experimentell untersucht. Abhängig von den Prozessbedingungen konnten in einer Batchfahrweise Restwassergehalte von ca. 0,2 Gew.‐% (2000 ppm) erreicht werden. Unter der Annahme einer Entwässerung bis ins Gleichgewicht konnten Dampfdruckkurven von IL/Wasser‐Lösungen und daraus Ausdampfwärmen abgeschätzt werden. Die während der Entwässerung online gemessene Viskosität erwies sich als geeignetes Maß zur Verfolgung des Entwässerungsprozesses.
Process Simulation of Ethanol and Methane Production from Lignocellulosic Raw Materials
Authors: Lassmann Tino , Kravanja Philipp , Friedl Anton 
Published: August 2011

AbstractDie Stoffstrom‐ und Energieanalyse mittels Prozesssimulation gibt einen guten Einblick in die Möglichkeiten der kombinierten Produktion von Ethanol und Methan. Eine Beschreibung des Gesamtprozesses, inklusive der gewählten Annahmen für die Simulation, bildet die Basis für die Bilanzierung. Es wird gezeigt, dass man annähernd 650 000 t a–1 Stroh (90 % Trockensubstanz, TS) bzw. 870 000 t a–1 Fichte (45 % TS) benötigt um 100 000 t a–1 Ethanol zu erzeugen. Der Biogasertrag für Stroh ist dabei mit 84,5 · 106 Nm3a–1 deutlich größer als der Ertrag aus Holz (22,5 · 106 Nm3a–1). Um die Effizienz der beiden Prozessvarianten vergleichen zu können, wird mittels energetischer Analyse der Wirkungsgrad berechnet, wobei sich für den Stroh‐Prozess ein etwas höherer Wert ergibt als für Fichte.
Designing the Mineralization of a Wastewater Sample from a Coating Industry
Authors: dos Santos Allan C. V. , Masini Jorge C. 
Published: August 2011

AbstractDesign of Fenton and photo‐Fenton reactions was partially automated by using sequential injection analysis (SIA) and response surface methodology for the treatment of a wastewater sample from a coatings industry. The extension of both Fenton and photo‐Fenton reactions was evaluated by the percentage of total organic carbon (TOC) remaining in solution after 15 min of reaction. Use of small volumes of sample and reagents, as well as easy solution handling, were the remarkable features of the proposed system. The highest percentage of TOC removal (79%) was obtained by the photo‐Fenton reaction at the following initial mass‐based concentration ratios: H2O2/TOC = 10, H2O2/FeSO4 = 50, and pH 2.5. The best result for Fenton reaction indicated a TOC removal of only 45%, obtained at H2O2/initial TOC = 20, H2O2/FeSO4 = 30, and pH 2.5. The SIA system was designed to dispense reagents to the sample flasks and to drive the sample intended to photo‐Fenton reaction through a homemade photo‐reactor. Modifications in chemical parameters of the reactions were achieved via the software commanding the SI system, without the need for physical reconfiguration of reagents around the selection valve.
Categorical formation of Mandarin color terms at different luminance levels
Authors: Hsieh T. J. , Chen I. P. 
Published: August 2011

AbstractThis study presents the categorical formation of a set of Mandarin color terms on the International Commission on Illumination (CIE) 1931 chromaticity diagram across six luminance levels. This article conducted a study that employed 44 native Mandarin speakers to perform a force–choice sorting task. The Mandarin color terms for sorting were determined by a free‐recall pretest and are consistent with basic color terms proposed by Berlin and Kay. The square‐sampled stimuli were generated by evenly sweeping the x–y diagram of 5, 10, 25, 50, 100, and 170 cd/m2 planes. The categorical sorting results and response time (RT) measurements suggest that: (1) the concepts of green, blue, purple, and gray stably exist at most luminance levels. The voting RT for the green, blue, and purple categories is particularly short. (2) Red, orange, yellow, and pink are highly luminance‐dependent; these can be identified without difficulty only at some restricted luminance levels. (3) The chromaticity areas designated as orange, partial yellow, red, and pink are recognized as brown when the luminance level decreases. (4) Brown and gray serve as representations of two distinct tints in the low saturation condition. (5) The location of boundaries between blue and green are remarkably different than those in a similar study that employed Japanese speakers. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2011.
Spectral analysis of blacks
Authors: Jafari Razieh , Amirshahi Seyed Hossein , Ravandi Seyed Abdolkarim Hosseini 
Published: August 2011

AbstractThe spectral behavior of different black surfaces including papers and fabrics are investigated in this study. Several colored pigments are mixed with the blacks in different concentrations to prepare black surfaces with different shades while a series of black dyestuffs are applied on textile materials to increase the ranges of black objects. The principal component analysis technique is applied to determine the actual spectral size of the reflectance dataset. The technique simply extracts the principal directions of spectral data and organizes them in restricted spectral spaces. Three different spectral spaces, i.e., the reflectance spectra, the Kubelka‐Munk function of reflectance as well as the inverse of reflectance factor are selected to present the samples in the restricted spaces. Based on the results, it is found that, there are no significant differences between the employed spaces and far from the employed spectral domains, black surfaces could be adequately described in a three‐dimensional space. The three extracted statistical colorants are used for reconstruction of reflectance spectra of samples while the root mean square error percentage and the color difference values under the standard observing condition confirm the suitability of such virtual primaries. The work is extended to reconstruction of spectral data from colorimetric information and the adequacy of such three‐dimensional space is reconfirmed. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012
The effects of achromatic and chromatic color schemes on participants' task performance in and appraisals of an office environment
Authors: Öztürk Elif , Yılmazer Semiha , Ural Sibel Ertez 
Published: August 2011

AbstractThis study explores the effects of chroma on participants' performance and environmental appraisal of an office. The research was conducted in a full‐scale experimental room designed as a private office where achromatic and chromatic color schemes with coequal values were applied. Sixty participants were assigned tasks and given a questionnaire to appraise the spatial color schemes. The findings show that chroma significantly affects performance and space appraisal. In terms of accuracy and time spent performance scores measured significantly better in the room with the chromatic scheme than those in the room with the achromatic scheme. The office with the chromatic scheme was found to be more pleasant, attractive, satisfying and dynamic than the one with the achromatic scheme, whereas the achromatic scheme was thought to be more formal and harmonious. Categorization of pleasantness, harmony, dynamism and spaciousness by factor analysis also showed differences between the achromatic and chromatic schemes. © 2011 Wiley Periodicals, Inc. Col Res Appl, 2012
Diameter‐Sorted SWCNT–Porphyrin and SWCNT–Phthalocyanine Conjugates for Light‐Energy Harvesting
Authors: Sandanayaka Atula S. D. , Subbaiyan Navaneetha K. , Das Sushanta K. , Chitta Raghu , Maligaspe Eranda , Hasobe Taku , Ito Osamu , D'Souza Francis 
Published: August 2011

AbstractA non‐covalent double‐decker binding strategy is employed to construct functional supramolecular single‐wall carbon nanotubes (SWCNT)–tetrapyrrole hybrids capable of undergoing photoinduced electron transfer and performing direct conversion of light into electricity. To accomplish this, two semiconducting SWCNTs of different diameters (6,5 and 7,6) were modified via π–π stacking of pyrene functionalized with an alkyl ammonium cation (PyrNH3+). Such modified nanotubes were subsequently assembled via dipole–cation binding of zinc porphyrin with one (1) or four benzo‐18‐crown‐6 cavities (2) or phthalocyanine with four benzo‐18‐crown‐6 cavities at the ring periphery (3), employed as visible‐light photosensitizers. Upon charactering the conjugates using TEM and optical techniques, electron transfer via photoexcited zinc porphyrin and phthalocyanine was investigated using time‐resolved emission and transient absorption techniques. Higher charge‐separation efficiency is established for SWCNT(7,6) with a narrow band gap than the thin SWCNT(6,5) with a wide band gap. Photoelectrochemical studies using FTO/SnO2 electrodes modified with these donor–acceptor conjugates unanimously demonstrated the ability of these conjugates to convert light energy into electricity. The photocurrent generation followed the trend observed for charge separation, that is, incident‐photon‐to‐current efficiency (IPCE) of a maximum of 12 % is achieved for photocells with FTO/SnO2/SWCNT(7,6)/PyrNH3+:1.
Synthesis from zinc oxalate, growth mechanism and optical properties of ZnO nano/micro structures
Authors: Raj C. Justin , Joshi R. K. , Varma K. B. R. 
Published: August 2011

AbstractWe report the synthesis of various morphological micro to nano structured zinc oxide crystals via simple precipitation technique. The growth mechanisms of the zinc oxide nanostructures such as snowflake, rose, platelets, porous pyramid and rectangular shapes were studied in detail under various growth conditions. The precursor powders were prepared using several zinc counter ions such as chloride, nitrate and sulphate along with oxalic acid as a precipitating agent. The precursors were decomposed by heating in air resulting in the formation of different shapes of zinc oxide crystals. Variations in ZnO nanostructural shapes were possibly due to the counter ion effect. Sulphate counter ion led to unusual rose‐shape morphology. Strong ultrasonic treatment on ZnO rose shows that it was formed by irregular arrangement of micro to nano size hexagonal zinc oxide platelets. The X‐ray diffraction studies confirmed the wurzite structure of all zinc oxide samples synthesized using different zinc counter ions. Functional groups of the zinc oxalate precursor and zinc oxide were identified using micro Raman studies. The blue light emission spectra of the various morphologies were recorded using luminescence spectrometer. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Synthesis and characterization of single crystals of the layered copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O
Authors: Švarcová S. , Klementová M. , Bezdička P. , Łasocha W. , Dušek M. , Hradil D. 
Published: August 2011

AbstractSingle‐crystals of the layered copper hydroxide acetate Cu2(OH)3(CH3COO)·H2O were synthesized by heating copper acetate solution at 60 °C. The standard synthesis of the title compound based on slow titration of copper acetate solution with NaOH yielded materials with worse morphology and an additional phase present. The obtained products were characterized with powder X‐ray diffraction, high temperature powder X‐ray diffraction, scanning electron microscopy and infrared spectroscopy. The crystal structure was determined from single‐crystal X‐ray diffraction data, collected both at 120 K and at 293 K. The title compound crystallizes in the monoclinic botallackite‐type layered structure, space group P 21, with the lattice parameters a = 5.5776(3) Å, b = 6.0733(2) Å, c = 18.5134(8) Å, β = 91.802(4)° and a = 5.5875(4)Å, b = 6.0987(4) Å, c = 18.6801(10)Å, β = 91.934(5)° for 120 K and for 293 K, respectively. Acetate groups and water molecules are interlayered between corrugated sheets of edge‐sharing CuO6 octahedra exhibiting strong distortion resulted from the Jahn‐Teller effect. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Rain attenuation measurements over terrestrial microwave links operating at 15 GHz in Malaysia
Authors: Abdulrahman A.Y. , Abdul Rahman T. , Abdulrahim S.K. , Rafiqul Islam Md. 
Published: August 2011

SUMMARYThis paper presents the experimental results of rain rate and rain attenuation measurements on six terrestrial microwave links in tropical Malaysia. The rain attenuation data were collected from six DIGI MINI‐LINKs (DiGi Telecommunications Sdn. Bhd., Malaysia, Shah Alam, Selangor Darul Ehsan, Malaysia) operating at 15 GHz with 99.95 % availability. The experimental results were compared with the International Telecommunication Union Radiocommunication Sector (ITU‐R) method and other existing rain attenuation prediction models. The main focus is on the ITU‐R prediction method, which underestimates the measured rain attenuation, more especially at extremely higher rain rates. The relationship between ITU‐R prediction errors and rainfall rates was studied, and it is shown that the two quantities are related by a quadratic function. The study will provide useful information on the design and planning of terrestrial radio links in Malaysia and similar tropical environments. Copyright © 2011 John Wiley & Sons, Ltd.