bluuebunny/crossref_metadata_2025_split huggingface dataset:
Facile Synthesis of Large meso‐Pentafluorophenyl‐Substituted Expanded Porphyrins
Authors: Tanaka Yasuo , Shin Ji‐Young , Osuka Atsuhiro 
Published: January 2008

AbstractAcid‐catalyzed condensation of meso‐pentafluorophenyl dipyrromethane 1 (100 mM) and pentafluorobenzaldehyde 2 (100 mM) at 0 °C gave a series of expanded porphyrins with even number of pyrrolic subunits up to octadecaphyrin(1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1) 18 in improved yields, particularly for larger expanded porphyrins. The solid‐state structure of decaphyrin(1.1.1.1.1.1.1.1.1.1) 10 was revealed by X‐ray diffraction analysis to be a crescent‐like conformation. The Soret‐like absorption bands are increasinglyredshifted as the size of the ring increases, but such atrend becomes nearly saturated for hexadecaphyrin(1.1.1.1.1.1.1.1.1.1.1.1.1.1.1.1) 16 and 18, which exhibit bands in the near‐infrared region at 939 and 953 nm, respectively.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Carbon Cavity Microelectrode for Electrical Wiring of Enzyme by Insoluble Electroactive Species in Aqueous Media
Authors: Cosnier Serge , Ionescu Rodica E. , Keddam Michel , Vivier Vincent 
Published: January 2008

AbstractThe carbon cavity microelectrode (CME), exhibiting a volume of 4×10−6 cm3, offers a genuine alternative for immobilizing and connecting enzymes in aqueous electrolytes by powder of insoluble redox materials. In the present work, the electrochemical behavior of two redox species such as ferrocene (Fc) and tetrathiafulvalene (TTF) was investigated with CME to evaluate their potentialities in the electrical wiring of enzymes. For this purpose, powder of two enzymes, glucose oxidase (GOx) and horseradish peroxidase (HRP), was independently mixed with an insoluble redox material and forced to fill the single micro cavity of a carbon electrode covered by an inert insulator. The presence of the electroactive species, as well as the enzyme wiring was investigated by cyclic voltammetry. The amperometric detection of glucose was carried out by potentiostating the TTF/GOx and the Fc/GOx microelectrodes at 0.25 and 0.35 V respectively. The amperometric detection of H2O2 by the TTF/HRP microelectrode was performed at −0.1 V vs. SCE.
Influence of varying electroosmotic flow on the effective diffusion in electric field gradient separations
Authors: Maynes Daniel , Tenny Joseph , Webbd Brent W. , Lee Milton L. 
Published: January 2008

AbstractRecently the use electric field gradient focusing (EFGF) to enhance focusing of proteins has been proposed and explored to provide significant improvement in separation resolution. The objective of EFGF is to focus proteins of specific electrophoretic mobilities at distinct stationary locations in a column or channel. This can be accomplished in a capillary by allowing the electric potential to vary in the streamwise direction. Because the electric field is varying, so also is the electrokinetic force exerted on the proteins and the electroosmotic velocity of the buffer solution. Due to the varying electric field, the Taylor diffusion characteristics will also vary along the column, causing a degradation of peak widths of some proteins, dependent on their equilibrium positions and local velocity distributions. The focus of this paper is an analysis that allows characterization of the local Taylor diffusion and resulting protein band peak width as a function of the local magnitude of the EOF relative to the average fluid velocity for both cylindrical and rectangular channels. In general the analysis shows that as the ratio of the local electroosmotic velocity to the average velocity deviates from unity, the effective diffusion increases significantly. The effectiveness of EFGF devices over a range of protein diffusivities, capillary diameters, flow velocities, and electric field gradient is discussed.
Simultaneous analysis of basic, acidic and neutral compounds on an endcapped octadecylsilane silica‐based monolith by pressure‐assisted capillary electrochromatography
Authors: Zhang Tong , Khadra Ibrahim , Euerby Melvin R. , Skellern Graham G. , Watson David G. , Tettey Justice N. A. 
Published: January 2008

AbstractThis simultaneous separation of basic, acidic and neutral analytes by pressure‐assisted CEC (pCEC) using a hybrid (tetramethoxysilane and methyltrimethoxysilane) silica‐based monolith, chemically modified with octadecyldimethylchlorosilane followed by endcapping with hexamethyldisilazane is described. The endcapping resulted in near Gaussian peaks for highly basic analytes such as nortriptyline without a significant loss in the EOF. The migration behaviour of analytes on this phase could be rationalised based on hydrophobicity, electrophoretic mobility and ion‐exchange interactions. The high porosity of the monolith allowed manipulation of the linear velocity of mobile phases by the addition of varying amounts of pressure at the inlet to reduce analysis times and overcome the reversed migration of anionic species towards the detection window in cathodic EOF mode. The concomitant programmed application of pressure (2–4 bar) and voltage (27 kV) facilitated the simultaneous separation of four cationic, four neutral and two anionic compounds in 6 min with efficiencies ranging from 41 000 to 94 000, 57 000 to 77 000 and 180 000 to 210 000 theoretical plates/metre, respectively. The % RSD values of migration times and efficiencies in pCEC mode were less than 3.6 and 7.9%, respectively (n = 5).
Transgenic λ medaka as a new model for germ cell mutagenesis
Authors: Winn Richard N. , Majeske Audrey J. , Jagoe Charles H. , Glenn Travis C. , Smith Michael H. , Norris Michelle B. 
Published: January 2008

AbstractTo address the need for improved approaches to study mutations transmitted to progeny from mutagen‐exposed parents, we evaluated λ transgenic medaka, a small fish that carries the cII mutation target gene, as a new model for germ cell mutagenesis. Mutations in the cII gene in progeny derived from ethyl‐nitrosourea (ENU)‐exposed males were readily detected. Frequencies of mutant offspring, proportions of mosaic or whole body mutant offspring, and mutational spectra differed according to germ cell stage exposed to ENU. Postmeiotic germ cells (spermatozoa/late spermatids) generated a higher frequency of mutant offspring (11%) compared to premeiotic germ cells (3.5%). Individuals with cII mutant frequencies (MF) elevated more than threefold above the spontaneous MF (3 × 10−5) in the range of 10−4 to 10−3 were mosaic mutant offspring, whereas those with MFs approaching 1 × 10−2 were whole body mutant offspring. Mosaic mutant offspring comprised the majority of mutant offspring derived from postmeiotic germ cells, and unexpectedly, from spermatogonial stem cells. Mutational spectra comprised of two different mutations, but at identical sites were unusual and characteristic of delayed mutations, in which fixation of a second mutation was delayed following fertilization. Delayed mutations and prevalence of mosaic mutant offspring add to growing evidence that implicates germ cells in mediating processes postfertilization that contribute to genomic instability in progeny. This model provides an efficient and sensitive approach to assess germ cell mutations, expands opportunities to increase understanding of fundamental mechanisms of mutagenesis, and provides a means for improved assessment of potential genetic health risks. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Modulatory activity of aLactobacillus caseistrain on 1,2‐dimethylhydrazine‐induced genotoxicity in rats
Authors: Villarini Milena , Caldini Giovanna , Moretti Massimo , Trotta Francesca , Pasquini Rossana , Cenci Giovanni 
Published: January 2008

AbstractThe present study was designed to investigate the putative antigenotoxic effects of supplementing the diet of rats treated with the colon carcinogen 1,2‐dimethylhydrazine hydrochloride (DMH) with aLactobacillus caseistrain using an in vivo approach. The antigenotoxic response was evaluated in colon and liver cells using the alkaline comet assay. Since the balance between the bioactivation and detoxification metabolic pathways is crucial for the formation of toxic and genotoxic metabolites, alterations in the level of some xenobiotic metabolizing enzymes (XME) were studied in liver preparations. In the challenge group (L. casei+ DMH), lactobacilli‐supplemented diet, there was a decrease in the extent of DMH‐induced DNA damage, especially in colon cells. Compared with control rats, there was less basal DNA damage in colon cells of rats fed on a lactobacilli‐supplemented diet. These findings are the first to give clear evidence of DNA‐protective effects of lactobacilli against basal DNA damage. Moreover, the chemopreventive effects were accompanied by changes in the activities of several XME. The observed decrease in the concentration of nonenzymatic antioxidants (i.e. GSH) and the reduced activity of enzymatic antioxidants (i.e., GST, GPx, and SOD) in liver could reflect an overall reduction in the level of oxidative stress in rats on a diet supplemented with theL. caseisuspension compared with control rats (basal state). Thus, the concentrations of GSH and the activities of GST, GPx, and SOD could be downregulated by supplementing the diet withL. caseias a response to an improved antioxidant status. Environ. Mol. Mutagen., 2008. © 2008 Wiley‐Liss, Inc.
Dynamic collapse analysis for a reinforced concrete frame sustaining shear and axial failures
Authors: Elwood Kenneth J. , Moehle Jack P. 
Published: January 2008

AbstractShaking table test results from a one‐story, two‐bay reinforced concrete frame sustaining shear and axial failures are compared with nonlinear dynamic analyses using models developed for the collapse assessment of older reinforced concrete buildings. The models provided reasonable estimates of the overall frame response and lateral strength degradation; however, the measured drifts were underestimated by the models. Selected model parameters were varied to investigate the sensitivity of the calculated response to changes in the drift at shear failure, rate of shear strength degradation, and drift at axial failure. For the selected ground motion, the drift at shear failure and rate of shear strength degradation did not have a significant impact on the calculated peak drift. By incorporating shear and axial‐load failure models, the analytical model is shown to be capable of predicting the axial‐load failure for a hypothetical frame with three nonductile columns. Improvements are needed in drift demand estimates from nonlinear dynamic analysis if such analyses are to be used in displacement‐based performance assessments. Copyright © 2008 John Wiley & Sons, Ltd.
Beamforming for satellite communications in emergency situations
Authors: Sow Garmy , Besson Olivier , Boucheret Marie‐Laure , Guiraud Cécile 
Published: January 2008

AbstractWe consider a multi‐beam Ka‐band satellite communication system aimed at operating in emergency situations where terrestrial communications systems are no longer effective. In contrast to most systems which use one single beam to cover a large area, we study here the feasibility of a one beam per user concept, where a beamformer is calculated for each user. This should allow to guarantee the maximum antenna gain towards each user.We assess the performance of the minimum variance distortionless response (MVDR) beamformer and of a beamformer using a training sequence in realistic scenarios including channel, steering vector and synchronisation errors. We show that both beamformers provide a sufficiently high output signal to noise ratio in a DVB–RCS system. Copyright © 2008 John Wiley & Sons, Ltd.
Increasing the power of identifying gene × gene interactions in genome‐wide association studies
Authors: Kooperberg Charles , LeBlanc Michael 
Published: January 2008

AbstractIn this paper we investigate the power to identify gene × gene interactions in genome‐wide association studies. In our analysis we focus on two‐stage analyses: analyses in which we only test for interactions between single nucleotide polymorphisms that show some marginal effect. We give two algorithms to compute significance levels for such an analyses. One involves a Bonferoni correction on the number of interactions that are actually tested, and one is a resampling procedure similar to the one proposed by [Lin (2006) Am. J. Hum. Genet. 78:505–509]. We also give an algorithm to carry out approximate power calculations for studies that plan to use a two‐stage analysis. We find that for most plausible interaction effects a two‐stage analysis can dramatically increase the power to identify interactions compared to a single‐stage analysis based on simulation studies using known genetic models and data from existing genome‐wide association studies. Genet. Epidemiol. 2008. © 2008 Wiley‐Liss, Inc.
Genome‐wide admixture mapping for coronary artery calcification in African Americans: the NHLBI Family Heart Study
Authors: Zhang Qunyuan , Lewis Cora E. , Wagenknecht Lynne E. , Myers Richard H. , Pankow James S. , Hunt Steven C. , North Kari E. , Hixson James E. , Jeffrey Carr J. , Shimmin Lawrence C. , Borecki Ingrid , Province Michael A. 
Published: January 2008

AbstractCoronary artery calcification (CAC) is an important measure of subclinical coronary atherosclerosis and an independent predictor of coronary heart disease. To identify the genetic loci contributing to CAC, we conducted a genome‐wide scan with 374 microsatellite markers by applying admixture mapping to 618 African American participants in the US National Heart, Lung, and Blood Institute Family Heart Study, in which 868 European American participants from family heart study and 157 Africans genotyped by the Marshfield Medical Genetics Center were used as the two reference founding populations for the African Americans, and a computer program based on a Markov Chain Monte Carlo algorithm, STRUCTURE 2.1, was used to estimate European and African ancestries among African Americans. A permutation test for random repeated sampling regression of CAC score on marker specific African ancestry found 22 markers statistically significant at the 0.05 level and four markers, D10S189 at 10p14, D20S159 at 20q13, D12S1294 at 12q14, and D6S1053 at 6q12, significant at the 0.01 level. D10S189 and D6S1053 were further confirmed at the 0.05 significance level by regression of CAC on allelic copy number, in which individual ancestry was used as a genetic background covariate to control possible stratification in African Americans. On the basis of the results from this and other independent studies, the location of D6S1053 at 80cM on chromosome 6 (6q12) seems to harbor a highly promising quantitative trait loci for atherosclerosis. Genet. Epidemiol. © 2008 Wiley‐Liss, Inc.
Stereoselective synthesis and biological activities of O‐(E)‐1‐{1‐[(6‐chloropyridin‐3‐yl)methyl]‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl}ethyleneamino‐O‐ethyl‐O‐arylphosphorothioates
Authors: Zhu Xiao‐Fei , Chen Xiao‐Bao , Yan Man , Shi De‐Qing , Ding Ke‐Rong 
Published: January 2008

AbstractTo find novel lead compounds having high insecticidal activity, a series of phosphorothioate derivatives containing 1,2,3‐triazole and pyridine rings were synthesized by the reaction of 1‐{1‐[(6‐chloropyridin‐3‐yl)methyl]‐5‐methyl‐1H‐1,2,3‐triazol‐4‐yl}ethanone oxime with phosphorochloridothioates. Their structures were confirmed by IR, 1H NMR, 31P NMR, mass spectrometry, and elemental analyses. The structure of 6c was determined by single crystal X‐ray diffraction, which is thermodynamically stable E isomer. The results of preliminary bioassay indicate that some title compounds possess insecticidal activity to some extent. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:15–20, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20367
Synthesis and conformational study of P‐heterocyclic androst‐5‐ene derivatives
Authors: Frank Éva , Schäfer Balázs , Mucsi Zoltán , Keglevich György 
Published: January 2008

AbstractThe reactions of (20R)‐3β‐acetoxy‐21‐hydroxymethylpregn‐5‐en‐20‐ol (2) and (20R)‐3β‐acetoxypregn‐5‐ene‐20,21‐diol (11) with phenylphosphonic dichloride 3 and aryl dichlorophosphates 4–6 afforded novel types of P‐heterocyclic androst‐5‐ene derivatives 7–10 and 12 as epimeric pairs. The diastereomers were separated by column chromatography and were characterized by NMR spectroscopy. Estimation of the stereostructures of the corresponding epimers by B3LYP/631G(d) DFT ab initio calculations suggested that the six‐membered hetero ring in compounds 7b and 8a–10a adopts predominantly a chair conformation, with the P‐substituents in their preferred orientation. The cyclic phosphonate moiety in 7a or 8b–10b, however, seems to exist as an equilibrium mixture of chair–distorted‐boat or chair–chair forms. The theoretical calculations indicate that the conformational equilibrium is shifted toward the distorted‐boat conformer for 7a, with a pseudoequatorial P‐phenyl substituent, whereas for 8b–10b the chair conformer with an equatorial P‐phenoxy group predominates. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:7–14, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20372
Microwave‐assisted synthesis of some 1,2,4‐triazol‐5‐one derivatives
Authors: Kahveci Bahittin , Özil Musa , Serdar Mevlüt 
Published: January 2008

AbstractA series of 3‐alkyl(aryl)‐4‐(p‐hydroxy‐phenyl)‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐ones 2 were obtained from the reaction of alkyl (aryl) ester ethoxycarbonyl hydrazones 1 with p‐hydroxy aniline. The reaction of 1 with 1,4‐diamino benzene (1:1) to afford 3‐alkyl(aryl)‐4‐(p‐aminophenyl)‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐ones 3. The reaction of 3 with benzaldehyde gave 3‐alkyl(aryl)‐4‐(4′‐benzilidenamino)‐4,5‐dihydro‐1H‐1,2,4‐triazol‐5‐ones 4. All of the above reactions occurred under microwave heating and conventional methods. Their structures were confirmed by 1H NMR, 13C NMR, IR, and elemental analyses. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:38–42, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20381
A facile and convenient synthesis of tetrasubstituted N‐hydroxypyrroles via intramolecular wittig reaction
Authors: Hekmatshoar Rahim , Nouri Roghieh , Beheshtiha S. Yahya Sh. 
Published: January 2008

AbstractTreatment of triphenylphosphine with dialkyl acetylenedicarboxylate leads to 1:1 adduct and concomitant protonation of late adduct by pentan‐2,3,4‐trione 3‐oxime gave the reactive intermediate, vinyltriphenylphosphonium salts, which undergoes an intramolecular Wittig reaction to produce tetrasubstituted N‐hydroxypyrroles in fairly high yields. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:100–103, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20382
Facile and efficient method for preparation of schiff bases catalyzed by P2O5/SiO2 under free solvent conditions
Authors: Naeimi Hossein , Sharghi Hashem , Salimi Fariba , Rabiei Khadijeh 
Published: January 2008

AbstractA simple and convenient method for the preparation of Schiff bases is developed. In this method, the Schiff base compounds were prepared from the reaction of carbonyl compounds with primary amines. In this reaction, P2O5/SiO2 have catalyzed the Schiff base formation in dry media under solvent‐free conditions. Advantages of this method are use of an inexpensive and efficient catalyst, high yields of products, short reaction times, and simpli‐city of the reaction and workup. © 2008 Wiley Periodicals, Inc. Heteroatom Chem 19:43–47, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/hc.20383
Phase II study of gefitinib for the treatment of recurrent and metastatic nasopharyngeal carcinoma
Authors: Chua Daniel T. T. , Wei William I. , Wong Maria P. , Sham Jonathan S. T. , Nicholls John , Au Gordon K. H. 
Published: January 2008

AbstractBackgroundThis single‐center, phase II study assessed the safety/tolerability and initial efficacy of gefitinib in patients with nasopharyngeal carcinoma (NPC) pretreated with platinum‐based chemotherapy.MethodsPatients with recurrent and metastatic NPC who had treatment failure with at least 2 lines of chemotherapy including platinum were given gefitinib at a fixed dose of 250 mg daily. Treatment was continued until the patient experienced unacceptable side effects or disease progression.ResultsNineteen patients were enrolled, having had treatment failure with a median of 2 chemotherapy regimens. Treatment was well tolerated, and only grades 1 to 2 adverse events were observed. None of the patients achieved partial or complete response. Median time‐to‐progression was 4 months, and median overall survival was 16 months.ConclusionGefitinib was well tolerated, but the response rate was poor in this heavily pretreated study population, and its use in NPC is not recommended outside the context of clinical trial. © 2008 Wiley Periodicals, Inc. Head Neck, 2008
Towards network and citizen: Collaborative care for drug abusers
Authors: Kihlström Anita , Wikström Ewa 
Published: January 2008

AbstractIn Sweden like in many other countries, inter‐organizational collaboration has been introduced to co‐ordinate the care for clients. Even so, the knowledge of how inter‐organizational collaboration is developed over time is limited today. This study focuses on how the inter‐organizational collaboration was conducted in the care for drug abusers over a period of 5 years. The study sought to answer the following questions: Which effect does inter‐organizational collaboration have on ways‐of‐working among professionals and which effect does inter‐organizational collaboration have on the services provided by the clients?We argue that inter‐organizational collaboration is developed through three processes. First, the professionals redefine ‘areas of responsibilities’ in the different organizations. Second, the professionals ‘reconstruct their ways of working’ with clients. Third, the professionals ‘organize a networking model with the client as citizen in the centre’. This paper describes how the three processes appeared in the studied inter‐organizational collaboration project ‘SANNA’ (Collaborative Care for drug abusers). Copyright © 2009 John Wiley & Sons, Ltd.
What sources contribute to variance in observer ratings? Using generalizability theory to assess construct validity of psychological measures
Authors: Lakes Kimberley D. , Hoyt William T. 
Published: January 2008

AbstractCronbach and Meehl (Psychol. Bull. 1955; 52:281–302) stated that the key question to be addressed when assessing construct validity is ‘What sources contribute to variance in test performance?’ We illustrate the utility of generalizability theory (GT) as a conceptual framework that encourages psychological researchers to address this question and as a flexible set of analytic tools that can provide answers to inform both substantive theory and measurement practice. To illustrate these capabilities, we analyze observer ratings of 27 caregiver–child dyads, focusing on the importance of situational (contextual) factors as sources of variance in observer ratings of caregiver–child behaviors. Cross‐situational consistency was relatively low for the categories of behavior analyzed, indicating that dyads vary greatly in their interactional patterns from one situation to the next, so that it is difficult to predict behavioral frequencies in one context from behaviors observed in a different context. Our findings suggest that single‐situation behavioral measures may have limited generalizability, either to behavior in other contexts or as measures of global interaction tendencies. We discuss the implications of these findings for research and measurement design in developmental psychology. Copyright © 2008 John Wiley & Sons, Ltd.