bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rapid identification and evaluation of antioxidant compounds from extracts of Petasites japonicus by hyphenated‐HPLC techniques
Authors: Kim Sang Min , Kang Suk Woo , Jeon Je‐Seung , Jung Yu‐Jin , Kim Chul Young , Pan Cheol Ho , Um Byung‐Hun 
Published: June 2011

ABSTRACTGradient HPLC coupled to Diode Array Detector (DAD), MS/MS and NMR was applied to the rapid structure determination of major compounds of methanol extracts from leaves and roots of Petasites japonicus. The relative antioxidant capacities of the compounds were evaluated by an HPLC system with post‐column on‐line antioxidant detection based on 2,2′‐azinobis‐3‐ethylbenzothiazoline‐6‐sulfonic acid radical scavenging. Six compounds were successfully separated on a reverse‐phase C18 column and were identified as 5‐caffeoylquinic acid (5‐CQA), fukinolic acid (FA), 3,5‐di‐O‐caffeoylquinic acid (3,5‐DCQA), quercetin‐3‐O‐(6″‐acetyl)‐β‐glucopyranoside (QAG), 4,5‐di‐O‐caffeoylquinic acid (4,5‐DCQA) and kaempferol‐3‐O‐(6″‐acetyl)‐β‐glucopyranoside (KAG) by MS/MS and 1H NMR data. Among these compounds, those containing a caffeoyl moiety (5‐CQA, FA, 3,5‐ and 4,5‐DCQA) showed relatively strong radical scavenging capacity, with 3,5‐DCQA having the greatest radical scavenging capacity in leaf (23.09% of total antioxidant capacity) and root (26.47%) extracts. The relative radical scavenging portion of QAG was only 3.41% in the leaves and KAG did not show any radical scavenging activity. These results demonstrate that the hyphenated HPLC techniques can be successfully applied to rapidly identify structures and evaluate antioxidant activities without prior purification of compounds from plant tissues of P. japonicus. Copyright © 2011 John Wiley & Sons, Ltd.
Sensitive, selective and rapid determination of bupropion and its major active metabolite, hydroxybupropion, in human plasma by LC‐MS/MS: application to a bioequivalence study in healthy Indian subjects
Authors: Parekh Jignesh M. , Sutariya Dipen K. , Vaghela Rajendrasinh N. , Sanyal Mallika , Yadav Manish , Shrivastav Pranav S. 
Published: June 2011

ABSTRACTA sensitive, selective and rapid liquid chromatography tandem mass spectrometry (LC‐MS/MS) method was developed for the simultaneous determination of bupropion (BUP) and its major active metabolite hydroxybupropion (HBUP) in human plasma. Separation of both the analytes and venlafaxine as internal standard (IS) from 50 μL human plasma was carried out by solid‐phase extraction. The chromatographic separation of the analytes was achieved on a Zorbax Eclipse XDB C18 (150 × 4.6 mm, 5 µm) analytical column using isocratic mobile phase consisting of 20 mm ammonium acetate–methanol (10:90, v/v), with a resolution factor of 3.5. The method was validated over a wide dynamic concentration range of 0.1–350 ng/mL for BUP and 0.1–600 ng/mL for HBUP. The matrix effect was assessed by post‐column infusion and the mean process efficiency was 96.08 and 94.40% for BUP and HBUP, respectively. The method was successfully applied to a bioequivalence study of 150 mg BUP (test and reference) extended release tablet formulation in 12 healthy Indian male subjects under fed conditions. Copyright © 2011 John Wiley & Sons, Ltd.
Fine Tuning of a Biological Machine: DnaK Gains Improved Chaperone Activity by Altered Allosteric Communication and Substrate Binding
Authors: Schweizer Regina S. , Aponte Raphael A. , Zimmermann Sabine , Weber Annika , Reinstein Jochen 
Published: June 2011

AbstractDnaK is a member of the Hsp70 family of molecular chaperones. This molecular machine couples the binding and hydrolysis of ATP to binding and release of substrate proteins. The switches that are involved in allosteric communication within this multidomain protein are mostly unknown. Previous insights were largely obtained by mutants, which displayed either wild‐type activity or reduced folding assistance of substrate proteins. With a directed evolution approach for improved folding assistance we selected a DnaK variant characterized by a glycine to alanine substitution at position 384 (G384A); this resulted in a 2.5‐fold higher chaperone activity in an in vitro DnaK‐assisted firefly luciferase refolding assay. Quantitative biochemical characterization revealed several changes of key kinetic parameters compared to the wild type. Most pronounced is a 13‐fold reduced rate constant for substrate release in the ATP‐bound state, which we assume, in conjunction with the resulting increase in substrate affinity, to be related to improved chaperone activity. As the underlying mechanistic reason for this change we propose an altered interface of allosteric communication of mutant G384A, which is notably located at a hinge position between nucleotide and substrate binding domain.
Enhanced Catalytic Performance by Zirconium Phosphate‐Modified SiO2‐Supported RuCo Catalyst for Fischer–Tropsch Synthesis
Authors: Bae Jong Wook , Park Seon‐Ju , Woo Min Hee , Cheon Joo Young , Ha Kyoung‐Su , Jun Ki‐Won , Lee Dong‐Hyun , Jung Hyun Min 
Published: June 2011

AbstractOur zirconium phosphate (ZrP)‐promoted Ru/Co/ZrP/SiO2 catalyst reveals a high catalytic activity and stability during Fischer–Tropsch synthesis. Surface modification with ZrP on SiO2 support with an appropriate amount of phosphorous component prevents cobalt particle aggregation and enhances its stability. These positive effects of ZrP are mainly induced by the spatial confinement of cobalt particles in a thermally stable ZrP matrix, and the catalytic performance was greatly improved when the P/(Zr+P) molar ratio was 0.134 on the CoZrP(0.5) catalyst.
Controlled Synthesis of Noble Metallic Dimers and the Influence of Secondary Metals on the Catalytic Activity
Authors: Zheng Zhaoliang , Li Hongfang , Shen Yanhua , Cao Rong 
Published: June 2011

AbstractTo precisely discuss the influence of secondary metals on the whole nanosystem, two different types of Pd/Au dimers are constructed by reducing Au precursors with or without ascorbic acid. The number and size of gold nanoparticles attaching on larger Pd nanocrystals can be roughly controlled. Furthermore, based on electrocatalysis, we find that multidecorated dimers are generally more active than singly decorated ones. Meanwhile, the amount of Au precursor used in preparing multidecorated dimers is found to be very important to the catalytic activity of the as‐prepared catalysts. The performance of the catalyst is enhanced with the increasing of Au precursor when the Au/Pd molar ratio is below 1:4, but hindered when the ratio climbs higher. Finally, this work provides a promising approach in forming hybrid nanocompositions to find an optimized amount of secondary metal, which is of significance in academic and economic fields.
Coordination Power Adjustment of Surface‐Regulating Polymers for Shaping Gold Polyhedral Nanocrystals
Authors: Lee Seon Joo , Park Garam , Seo Daeha , Ka Duyoun , Kim Sang Youl , Chung Im Sik , Song Hyunjoon 
Published: June 2011

AbstractPVP (poly(vinyl pyrrolidone)) is a common polymer that behaves as a surface‐regulating agent that shapes metal nanocrystals in the polyol process. We have used different polymers containing tertiary amide groups, namely PVCL (poly(vinyl caprolactam)) and PDMAm (poly(N,N‐dimethyl acrylamide)), for the synthesis of gold polyhedrons, including octahedrons, cuboctahedrons, cubes, and higher polygons, under the present polyol reaction conditions. The basicity and surface coordination power of the polymers are in the order of PVCL, PVP, and PDMAm. A correlation is observed between the coordination power of the polymers and the resulting gold nanocrystal size. Strong coordination and electron donation from the polymer functional groups to the gold surface restrict particle growth rates, which leads to small nanocrystals. The use of PVCL can yield gold polyhedral structures with small sizes, which cannot be achieved in the reactions with PVP. Simultaneous hydrolysis of the amide group in PDMAm leads to carboxylate functionality, which is very useful for generating chemical and bioconjugates through the formation of ester and amide bonds.
Investigation of Multiphase Flows on Inclined Plates as Potential Design Tool for Separation Devices
Authors: Repke Jens‐Uwe , Kohrt Martin , Wozny Günter 
Published: June 2011

AbstractFlüssigkeiten strömen in verfahrenstechnischen Apparaten häufig in Form von Filmen und Rinnsalen. Das grundlegende Verständnis der Stoffübergangsvorgänge in diesen meist unter 1 mm dicken Strömungen ist von wesentlicher Bedeutung für die Auslegung von Apparaten. Dabei können wichtige Erkenntnisse zur Strömungsform und zum Stoffübergang bereits an einfachen Platten gewonnen werden. In Basisuntersuchungen wird der Einfluss von Oberflächenstrukturen auf den Stoffübergang und auf das Strömungsfeld experimentell nachgewiesen. Die Ergebnisse könnten künftig für die Validierung von CFD‐Modellen und die signifikante Weiterentwicklung von eingesetzt werden.
Mining query log graphs towards a query folksonomy
Authors: Francisco Alexandre P. , Baeza‐Yates Ricardo , Oliveira Arlindo L. 
Published: June 2011

SUMMARYThe human interaction through the web generates both implicit and explicit knowledge. An example of an implicit contribution is searching, as people contribute with their knowledge by clicking on retrieved documents. When this information is available, an important and interesting challenge is to extract relations from query logs, and, in particular, semantic relations between queries and their terms. In this paper, we present and discuss results on query contextualization through the association of tags to queries, that is, query folksonomies. Note that tags may not even occur within the query. Our results rely on the analysis of large query log induced graphs, namely click induced graphs. Results obtained with real data show that the inferred query folksonomy provide interesting insights both on semantic relations among queries and on web users intent.Copyright © 2011 John Wiley & Sons, Ltd.
Primary role of multiparametric flow cytometry in the diagnostic work‐up of indolent clonal mast cell disorders
Authors: Perbellini Omar , Zamò Alberto , Colarossi Sabrina , Zampieri Francesca , Zoppi Francesca , Bonadonna Patrizia , Schena Donatella , Artuso Anna , Martinelli Giovanni , Chilosi Marco , Pizzolo Giovanni , Zanotti Roberta 
Published: June 2011

AbstractBackground:According to the World Health Organization (WHO) classification the diagnosis of systemic mastocytosis (SM) relies on bone marrow (BM) examination and is based on one major and four minor criteria. Herein, we used WHO criteria to compare flow cytometry (FC) with other available techniques in the diagnosis of SM after BM examination.Methods:We analyzed a cohort of 95 patients with suspect SM. All patients underwent comprehensive BM examination by using cytology, immunohistochemistry, FC and molecular study for mutation of c‐Kit and serum tryptase dosage. FC evaluation was based on a combination of monoclonal antibodies, specifically CD25/CD2/CD45/CD34/CD117.Results:Seventy‐four out of ninety‐five patients were diagnosed with indolent SM (n = 59) or monoclonal mast cell activation syndrome (n = 15) because satisfying less than 3 minor criteria. Thirty‐nine out of these seventy‐four patients fulfilled the major histological criterion, whereas the presence of a minor criterion was assessed by FC, molecular study, cytology, and tryptase level in 70/74, 52/67, 56/74, and 42/74 patients, respectively.FC showed higher sensitivity than IHC in detection of CD25+ mast cells (MC) (92.9% vs. 73.8%; P = 0.019), especially in the absence of the major histological criterion (90.5% vs. 47.6%; P = 0.003). Moreover, CD2 expression was documented by FC and IHC in 97.1% and 35.3% of cases, respectively (P < 0.001).Conclusions:FC showed the best sensitivity for identifying abnormal MC compared to other techniques, especially in cases with low MC burden. Therefore, we hope for a major role of FC in the diagnostic work‐up of clonal MC disorders. © 2011 International Clinical Cytometry Society
Maturation of shoaling behavior is accompanied by changes in the dopaminergic and serotoninergic systems in zebrafish
Authors: Buske Christine , Gerlai Robert 
Published: June 2011

AbstractThe zebrafish has been one of the preferred vertebrate model organisms of developmental biology, and is becoming an important research tool for behavioral neuroscience and behavior genetics. A prominent feature of zebrafish is their strong shoaling tendency. Most recently, the first study investigating the development of shoaling in zebrafish demonstrated that a few days after hatching zebrafish do not shoal, but that shoaling tendency gradually increases during development. The current study investigates this phenomenon using the nearest neighbor distance, a measure most frequently employed for the quantification of shoal cohesion in fish. We demonstrate that shoal cohesion increases with age, while thigmotaxis, “wall hugging,” does not show a consistent age‐dependent change. The mechanisms underlying the maturation of shoaling are unknown. HPLC analysis of whole brain extracts finds the concentration of dopamine, DOPAC, serotonin, and 5‐HIAA normalized to total brain protein weight to increase with age. Although the behavioral and neurochemical results are only correlative at this point, they may open a new avenue into the investigation of the mechanisms and development of social behavior in zebrafish. © 2011 Wiley Periodicals, Inc. Dev Psychobiol 54:28–35, 2012.
Experimental and Theoretical Study of the Keto–Enol Tautomerization of 3,5‐Dioxopimelates
Authors: Erfle Silke , Reim Stefanie , Michalik Dirk , Jiao Haijun , Langer Peter 
Published: June 2011

AbstractSubstituted 3,5‐dioxopimelic acid diesters, stable 1,3,5,7‐tetracarbonyl derivatives, were prepared by condensation of 1,3‐bis(trimethylsilyloxy)‐1,3‐butadienes with methyl malonyl chloride. The influence of the substituents and the solvent on the keto–enol tautomerization of these compounds was investigated by NMR spectroscopy. For the parent compound, the experimental findings were compared with computational results.
An Original On‐Column Oxidative Cleavage of Vicinal Diols Using Alumina/Potassium Periodate: Application to Sequential Oxidation/Horner–Emmons Reactions
Authors: Dakdouki Saada C. , Villemin Didier , Bar Nathalie 
Published: June 2011

AbstractAn unprecedented simple on‐column solvent‐free oxidative cleavage of vicinal diols in the solid phase using alumina/potassium metaperiodate is described herein. It permits preparation of the corresponding carbonyl compounds with high purity and good to excellent yields requiring only short reaction times. This methodology is then employed in on‐column sequential oxidation/Horner–Emmons reactions for the preparation of selected stilbenes in good yields where both reaction and purification are integrated in a single unit or occur simultaneously permitting the rapid and easy preparation of small samples of pure stilbenes.
Fluvial and slope‐wash erosion of soil‐mantled landscapes: detachment‐ or transport‐limited?
Authors: Pelletier Jon D. 
Published: June 2011

ABSTRACTMany numerical landform evolution models assume that soil erosion by flowing water is either purely detachment‐limited (i.e. erosion rate is related to the shear stress, power, or velocity of the flow) or purely transport‐limited (i.e. erosion/deposition rate is related to the divergence of shear stress, power, or velocity). This paper reviews available data on the relative importance of detachment‐limited versus transport‐limited erosion by flowing water on soil‐mantled hillslopes and low‐order valleys. Field measurements indicate that fluvial and slope‐wash modification of soil‐mantled landscapes is best represented by a combination of transport‐limited and detachment‐limited conditions with the relative importance of each approximately equal to the ratio of sand and rock fragments to silt and clay in the eroding soil. Available data also indicate that detachment/entrainment thresholds are highly variable in space and time in many landscapes, with local threshold values dependent on vegetation cover, rock‐fragment armoring, surface roughness, soil texture and cohesion. This heterogeneity is significant for determining the form of the fluvial/slope‐wash erosion or transport law because spatial and/or temporal variations in detachment/entrainment thresholds can effectively increase the nonlinearity of the relationship between sediment transport and stream power. Results from landform evolution modeling also suggest that, aside from the presence of distributary channel networks and autogenic cut‐and‐fill cycles in non‐steady‐state transport‐limited landscapes, it is difficult to infer the relative importance of transport‐limited versus detachment‐limited conditions using topography alone. Copyright © 2011 John Wiley & Sons, Ltd.
Experimental analysis of the effectiveness of emergency signage and its implementation in evacuation simulation
Authors: Xie Hui , Filippidis Lazaros , Galea Edwin R , Blackshields Darren , Lawrence Peter J 
Published: June 2011

SUMMARYSignage systems play an important role in aiding occupants during both circulation and evacuation. Despite the fact that signage systems are an important component in building wayfinding systems, there is a lack of relevant data regarding how occupants perceive, interpret and use the information conveyed by emergency signage. The effectiveness of signage systems is therefore difficult to assess. In this paper, we address this issue through experimentation. The experiment involved measuring the impact of a signage system on a population of 68 test subjects who were instructed to individually vacate a building as quickly as possible via any means they thought appropriate. The evacuation path involved a number of decision points at which emergency signage was available to identify the appropriate path. Through analysis of video footage and data derived from questionnaires, the number of people who saw and utilised the signage information to assist their egress is determined. The experimental results are used to enhance the existing signage model within the buildingEXODUS software. In particular, the signage detection and acceptance probabilities are assigned values based on the experimental data rather than the ideal values previously used in the model. The impact that the enhanced signage model has on evacuation analysis is demonstrated in a hypothetical evacuation scenario. The enhanced signage model is shown to produce a more conservative lower estimate of expected egress times. Copyright © 2011 John Wiley & Sons, Ltd.
Smoke oxidation kinetics for application to prediction of clean burn patterns
Authors: Hartman J. R. , Beyler A. P. , Riahi S. , Beyler C. L. 
Published: June 2011

SUMMARYSmoke deposition patterns are a potentially rich source of information concerning the behavior of a fire. Clean burn patterns are smoke‐free areas where smoke deposits have been oxidized away. In order to predict the formation of clean burn patterns, smoke oxidation kinetics are required. Smoke oxidation kinetics were studied for smokes from acrylonitrile butadiene styrene, polymethylmethacrylate, polypropylene, and gasoline. The fuels were burned below a hood, and smoke samples were collected from the hot gas layer and from the wall surfaces. The smokes from various polymers and gasoline were found to contain no measurable volatile organic chemicals. The kinetics of the smokes from the polymers and gasoline were found to be satisfactorily modeled as first order in both smoke and oxygen with the same kinetic constants for all fuels tested. The activation energy was calculated to be 211 kJ/mol, and the pre‐exponential factor was found to be 4.7 × 1010/s. These kinetic parameters provide a basis for modeling clean burn pattern generation. Copyright © 2011 John Wiley & Sons, Ltd.
Performance Evaluation of Solid Oxide Fuel Cells with Thin Film Electrolyte Fabricated by Binder‐Assisted Slurry Casting
Authors: Guo W. M. , Xiao Y. F. , Liu X. M. , Chen Y. , Li L. J. 
Published: June 2011

AbstractA gas‐tight yttria‐stabilized zirconia (YSZ) electrolyte film was fabricated on porous NiO–YSZ anode substrates by a binder‐assisted slurry casting technique. The scanning electron microscope (SEM) results showed that the YSZ film was relatively dense with a thickness of 10 μm. La0.8Sr0.2MnO3 (LSM)–YSZ was applied to cathode using a screen‐print technique and the single fuel cells were tested in a temperature range from 600 to 800 °C. An open circuit voltage (OCV) of over 1.0 V was observed. The maximum power densities at 600, 700, and 800 °C were 0.13, 0.44, and 1.1 W cm–2, respectively.
CORAL: Quantitative structure–activity relationship models for estimating toxicity of organic compounds in rats
Authors: Toropova A. P. , Toropov A. A. , Benfenati E. , Gini G. , Leszczynska D. , Leszczynski J. 
Published: June 2011

AbstractFor six random splits, one‐variable models of rat toxicity (minus decimal logarithm of the 50% lethal dose [pLD50], oral exposure) have been calculated with CORAL software (http://www.insilico.eu/coral/). The total number of considered compounds is 689. New additional global attributes of the simplified molecular input line entry system (SMILES) have been examined for improvement of the optimal SMILES‐based descriptors. These global SMILES attributes are representing the presence of some chemical elements and different kinds of chemical bonds (double, triple, and stereochemical). The “classic” scheme of building up quantitative structure–property/activity relationships and the balance of correlations (BC) with the ideal slopes were compared. For all six random splits, best prediction takes place if the aforementioned BC along with the global SMILES attributes are included in the modeling process. The average statistical characteristics for the external test set are the following: n = 119 ± 6.4, R2 = 0.7371 ± 0.013, and root mean square error = 0.360 ± 0.037. © 2011 Wiley Periodicals, Inc. J Comput Chem, 2011
Imaging and assessment of placental function
Authors: Moran Mary , McAuliffe Fionnuala M. 
Published: June 2011

AbstractThe placenta is the vital support organ for the developing fetus. This article reviews current ultrasound (US) methods of assessing placental function. The ability of ultrasound to detect placental pathology is discussed. Doppler technology to investigate the fetal, placental, and maternal circulations in both high‐risk and uncomplicated pregnancies is discussed and the current literature on the value of three‐dimensional power Doppler studies to assess placental volume and vascularization is also evaluated. The article highlights the need for further research into three‐dimensional ultrasound and alternative methods of placental evaluation if progress is to be made in optimizing placental function assessment. © 2011 Wiley Periodicals, Inc. J Clin Ultrasound, 2011
An efficient three‐component synthesis of hexahydroquinoline derivatives in ionic liquid
Authors: Wang Ju‐Xian , Shen Gao‐Ling , Shi Da‐Qing 
Published: June 2011

AbstractA series of hexahydroquinoline derivatives were synthesized by the three‐component reaction of 5,5‐dimethyl‐3‐aminocyclohex‐2‐enone, aromatic aldehyde, and acyl acetonitrile in ionic liquid without using any catalyst. This protocol has the advantages of easier work‐up, milder reaction conditions, high yields, and environmentally benign procedure. J. Heterocyclic Chem., (2011).