bluuebunny/crossref_metadata_2025_split huggingface dataset:
Performing RVE calculations under constant stress triaxiality for monotonous and cyclic loading
Authors: Lin R. C. , Steglich D. , Brocks W. , Betten J. 
Published: December 2005

AbstractIn the present work the mesoscopic stress, strain rate and strain states of axisymmetric cells under two types of boundary loadings are formulated. Then, the stress triaxiality of axisymmetric cells is expressed in terms of the axial and radial mesoscopic stress components. Based on the formulations of the mesoscopic stress, three strategies for numerical realization of constant stress triaxiality are presented. The advantages and disadvantages of these strategies are discussed. These numerical strategies are implemented on the platform of the general‐purpose finite element programme ABAQUS. They can be applied for representative volume element (RVE) calculations under constant triaxiality, monotonous and cyclic loading controlled by displacement, force, traction and the mesoscopic equivalent strain of the RVE. Several numerical examples are shown to prove the effectivity of these strategies and programme. Copyright © 2005 John Wiley & Sons, Ltd.
The expression of fibroblast growth factors and their receptors in Hodgkin's lymphoma
Authors: Khnykin Denis , Troen Gunhild , Berner Jeanne‐Marie , Delabie Jan 
Published: December 2005

AbstractThe expression of fibroblast growth factors (FGF1 and FGF2) and their receptors has been reported in a variety of human neoplasms, including haematological neoplasia. Fibroblast growth factors can promote tumour growth directly, or indirectly through promoting the growth of vessels. In the present study, we evaluated the expression of FGF1 and FGF2 as well as FGF receptors 1–4 (FGFR1–FGFR4) in 39 cases of Hodgkin's lymphoma, including all subtypes, as well as Hodgkin's lymphoma cell lines. FGF1 and FGF2 and their receptors FGFR2–FGFR4, but not FGFR1, were found to be expressed by the malignant cells in the majority of cases. Interestingly, only FGFR3, but none of the FGFs or the other FGFRs, was expressed by the Hodgkin's lymphoma cell lines. This indicates that only FGFR3 is constitutively expressed by Hodgkin's lymphoma cells, whereas FGFs and the other FGFRs are induced in vivo. Culture of the Hodgkin's cell lines under conditions of hypoxic stress could induce vascular endothelial growth factor (VEGF) but not FGF expression. FGFs, in contrast to VEGF, might be expressed in response to paracrine stimuli. In situ hybridization did not reveal FGFR3 gene amplification or translocation as the cause of constitutive FGFR3 expression, as has been shown in a subset of multiple myeloma. FGFR3 might be expressed as part of the Hodgkin's cell phenotype. The demonstration of widespread expression of FGFs and some of their receptors in Hodgkin's lymphoma suggests that FGFs are important for sustaining growth of the lymphoma and suggests that anti‐FGF antibodies could be used as an adjuvant treatment. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Expression and functional analysis of Bax inhibitor‐1 in human breast cancer cells
Authors: Grzmil Michal , Kaulfuss Silke , Thelen Paul , Hemmerlein Bernhard , Schweyer Stefan , Obenauer Silvia , Won Kang Tae , Burfeind Peter 
Published: December 2005

AbstractRecently, deregulated expression of the anti‐apoptotic protein Bax inhibitor‐1 (BI‐1) has been shown in several human cancers. In this report, we show that BI‐1 is expressed at various levels in six different human breast cancer cell lines. In order to investigate the function of BI‐1 in oestrogen‐dependent MCF‐7, T‐47D and oestrogen‐independent MDA‐MB‐231 breast cancer cells, the RNA interference technique was used to knock down BI‐1 expression specifically. Suppression of BI‐1 expression caused a significant increase in spontaneous apoptosis in MDA‐MB‐231 cells, whereas MCF‐7 and T‐47D cells remained almost unaffected. Furthermore, BI‐1 expression analysis using a cancer profiling array showed up‐regulation of BI‐1 expression in cancer samples of breast, uterus and ovary, whereas down‐regulated BI‐1 expression was identified in stomach, colon, kidney, lung and rectal cancer. In addition, immunohistochemical studies using a BI‐1‐specific antibody on human breast cancer specimens also revealed that BI‐1 is expressed in the majority of cases. Moreover, to analyse whether BI‐1 expression is oestrogen receptor‐dependent, tumour cells were treated with oestradiol, ICI and tamoxifen: this showed no significant changes in BI‐1 expression. Taken together, our results demonstrate that BI‐1 expression is differentially deregulated in different cancers and that BI‐1 plays an important role in preventing certain breast cancer cells from undergoing apoptosis. Thus, the development of novel therapeutic strategies based on targeting BI‐1 gene expression in breast cancer could be restricted to selected individual cancer types. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
PIK3CA mutation and histological type in breast carcinoma: high frequency of mutations in lobular carcinoma
Authors: Buttitta Fiamma , Felicioni Lara , Barassi Fabio , Martella Carla , Paolizzi Diego , Fresu Giuseppina , Salvatore Simona , Cuccurullo Franco , Mezzetti Andrea , Campani Daniela , Marchetti Antonio 
Published: December 2005

AbstractMutations in the PIK3CA gene have recently been reported in different human neoplasms, including breast cancer. This paper reports the results of a systematic analysis of PIK3CA mutations in different histological types of breast carcinoma. One hundred and eighty invasive breast carcinomas, comprising 74 ductal, 56 lobular, 22 mucinous, 20 medullary, and eight papillary, were selected on the basis of their histological type in a consecutive series of 780 breast cancers. Exons 1–20 of the PIK3CA gene were subjected to SSCP analysis followed by direct sequencing. PIK3CA mutations were observed in 46 (26%) of the 180 tumours examined: 23 (50%) mutations were located in exon 9, and 23 (50%) in exon 20. Mutations were frequent in lobular (46%), less frequent in ductal (22%), and uncommon in medullary (10%), mucinous (5%), and papillary tumours (12%) (p = 0.0002). Mutations in exon 9 were more frequent in lobular carcinomas (30% of cases) than in the other histological types (less than 5% of cases) (p = 0.00014). No significant differences were observed in the distribution of mutations in exon 20. There was no significant correlation between PIK3CA mutations and other clinicopathological and biological variables, including age, tumour size, lymph node metastases, oestrogen receptor (ER) status, progesterone receptor (PgR) status, p53 gene mutations, and p53 protein expression. The findings indicate that in invasive breast carcinomas, PIK3CA alterations are mainly present in lobular and ductal tumours, whereas the other histological types, known to be associated with a favourable prognosis, show a very low incidence of PIK3CA mutations. Copyright © 2005 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
The flow‐through diffusion cell (FTDC) method: a novel approach to in vitro drug release studies
Authors: Bajpai Sunil K , Saxena Sutanjay , Dubey Seema 
Published: December 2005

AbstractA terpolymeric semi‐interpenetrating network (IPN) has been synthesized by carrying out the aqueous polymerization of methacrylamide in the presence of poly(ethylene glycol) (PEG) and natural polysaccharide starch, and its enzymatic degradation has been studied by a newly developed technique, known as the ‘flow‐through diffusion cell’ (FTDC) method, in a phosphate buffer medium of pH 6.8 at the physiological temperature, 37 °C. The hydrogel exhibits different degradation behaviors when studied by the ‘traditional degradation/dissolution test’ (TDT) or the FTDC method. The degradability is suppressed in the FTDC method, owing to the adsorption of amylase molecules onto the filler particles. The nature of the filler particles also affects the degradation behavior of the hydrogels. Finally, the release of the model drug, vitamin B12, from the degrading hydrogels has also been studied by the FTDC method. The results obtained indicated that the release behavior also depends on α‐amylase‐induced degradability. Copyright © 2006 Society of Chemical Industry
Domain interactions direct misfolding and amyloid formation of yeast phosphoglycerate kinase
Authors: Osváth Szabolcs , Jäckel Márta , Agócs Gergely , Závodszky Péter , Köhler Gottfried , Fidy Judit 
Published: December 2005

AbstractThere are proteins that are built of two structural domains and are deposited full‐length in amyloid plaques formed in various diseases. In spite of the known differences in the mechanisms of folding of single‐ and multidomain proteins, no published studies can be found that address the role of the domain–domain interactions during misfolding and amyloid formation. By the discovery of the role of domain–domain interactions, here we provide important insight in the submolecular mechanism of amyloid formation. A model system based on yeast phosphoglycerate kinase was designed. This system includes the wild‐type yeast phosphoglycerate kinase and single‐tryptophan mutants of the individual N and C terminal domains and the complete protein. Electron microscopic measurements proved that amyloid fibrils grow from all mutants under identical conditions as for the wild‐type protein. Misfolding and amyloid formation was followed in stopped‐flow and manual mixing experiments on the 1 ms to 4 days timescale. Tryptophan fluorescence was used for selective detection of conformational changes accompanying the formation of the amyloidogenic intermediates and the growth of amyloid fibrils. The interactions between the polypeptide chains of the two domains direct the misfolding process from the early steps to the amyloid formation, and influence the final structure. The kinetics of misfolding is different for the individual domains, pointing to the significance of the amino acid sequence. Misfolding of the domains within the complete protein is synchronized indicating that domain–domain interactions direct the misfolding and amyloid formation mechanism. Proteins 2006. © 2005 Wiley‐Liss, Inc.
Physisorption of N2 on graphene platelets: An Ab initio study
Authors: Zhechkov Lyuben , Heine Thomas , Seifert Gotthard 
Published: December 2005

AbstractThe interaction of molecular nitrogen with selected polycyclic aromatic hydrocarbons (PAHs), i.e., benzene, naphthalene, anthracene, pentacene, coronene, and triphenylene, is investigated. The energetically most favorable orientation of N2 is parallel to the PAH, with a distance of 3.2 Å, independent on shape and size of the investigated PAHs. An interaction energy of 10–17 kJ mol−1, depending on PAH size, shape and adsorption position, is calculated using Møller–Plesset perturbation theory. A value of 17.7 kJ mol−1 is obtained by extrapolation to infinite graphene. Hence, N2 is physisorbed 2–3 times stronger than H2 on PAHs. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
QSAR and 3D QSAR of inhibitors of the epidermal growth factor receptor
Authors: Pinto‐Bazurco Mariano , Tsakovska Ivanka , Pajeva Ilza 
Published: December 2005

AbstractThis article reports quantitative structure–activity relationships (QSAR) and 3D QSAR models of 134 structurally diverse inhibitors of the epidermal growth factor receptor (EGFR) tyrosine kinase. Free–Wilson analysis was used to derive the QSAR model. It identified the substituents in aniline, the polycyclic system, and the substituents at the 6‐ and 7‐positions of the polycyclic system as the most important structural features. Comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) were used in the 3D QSAR modeling. The steric and electrostatic interactions proved the most important for the inhibitory effect. Both QSAR and 3D QSAR models led to consistent results. On the basis of the statistically significant models, new structures were proposed and their inhibitory activities were predicted. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Theoretical study of some verapamil derivatives
Authors: Ionescu Sorana , Diaconu Carmen C. , Hillebrand Mihaela 
Published: December 2005

AbstractA theoretical study of some sulfur‐containing analogues of verapamil was performed using the AM1 Hamiltonian, together with the SM5.4A solvation model. Lipophilicity and the tendency of H‐bond formation of these drugs were previously correlated with their biologic activity. In the present work they were described theoretically in terms of the calculated energy of solvation and the electrostatic potential on the sulfur and nitrogen atoms, respectively. Experimental data such as the high‐performance liquid chromatography (HPLC) retention time were correlated with the calculated solvation energy. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006
Detection of royal jelly adulteration using carbon and nitrogen stable isotope ratio analysis
Authors: Stocker A. , Rossmann A. , Kettrup A. , Bengsch E. 
Published: December 2005

AbstractStable isotope ratios (13C/12C and 15N/14N) were measured in royal jelly (RJ) samples by isotope ratio mass spectrometry (IRMS) to evaluate authenticity and adulteration. Carbon and nitrogen isotope contents (given as delta values relative to a standard, δ13C, δ15N) of RJ samples from various European origins and samples from commercial sources were analyzed. Uniform δ13C values from −26.7 to −24.9‰ were observed for authentic RJ from European origins. Values of δ15N ranged from −1.1 to 5.8‰ depending on the plant sources of nectars and pollen. High δ13C values of several commercial RJ samples from −20.8 to −13.3‰ indicated adulteration with high fructose corn syrup (HFCS) as a sugar source. Use of biotechnologically produced yeast powder as protein source for the adulterated samples was assumed as δ15N values were lower, as described for C4 or CAM plant sources. RJ samples from authentic and from adulterated production were distinguished. The rapid and reliable method is suitable for urgent actual requirements in food monitoring. Copyright © 2005 John Wiley & Sons, Ltd.
Profiling of ecdysteroids in complex biological samples using liquid chromatography/ion trap mass spectrometry
Authors: Li Yutai , Warren James T. , Boysen Gunnar , Gilbert Lawrence I. , Gold Avram , Sangaiah Ramiah , Ball Louise M. , Swenberg James A. 
Published: December 2005

AbstractA sensitive method using high‐performance liquid chromatography coupled to a mass spectrometer with electrospray ionization source (HPLC/ESI‐MS) was developed for detection of ecdysteroids in biological samples. We report here for the first time that ecdysteroids can be classified into three groups based on ESI full‐scan mass spectra: group 1 (ecdysone (E), 2‐deoxyecdysone (2dE), 2,22‐dideoxyecdysone (3β5β‐KT), and 3α5α[H]‐dihydroxycholest‐7‐en‐6‐one (3α5α‐KD)), in which loss of one molecule of water from the protonated molecular ion ([M+H]+) represents the dominant ion; group 2 (20‐hydroxyecdysone (20E), makisterone A (MakA), 3β5β‐KD, and 3β5α‐KD), in which [M+H]+ is a major ion but some water loss is observed; and group 3 (muristerone A (MurA) and ponasterone A (PonA)), in which [M+H]+ is the dominant ion with no water loss observed. Based on the analytical procedure in combination with structural information from the group classification and with the application of source‐induced dissociation, we identified free ecdysteroids in biological samples: 20,26‐dihydroxyecdysone and ecdysonic acid in the larval hemolymph, and the progressive metabolism of 26‐hydroxyecdysone (26E) to 3α‐26E from day‐1 to day‐3 embryos of the tobacco hornworm Manduca sexta. Copyright © 2005 John Wiley & Sons, Ltd.
Electrospray ionization quadrupole time‐of‐flight tandem mass spectrometric analysis of hexamethylenediamine‐modified maltodextrin and dextran
Authors: Sisu Eugen , Bosker Wouter T. E. , Norde Willem , Slaghek Ted M. , Timmermans Johan W. , Peter‐Katalinić Jasna , Cohen‐Stuart Martien A. , Zamfir Alina D. 
Published: December 2005

AbstractA combined methodology for obtaining at the preparative scale and characterization by nanoelectrospray ionization (nanoESI) quadrupole time‐of‐flight (QTOF) mass spectrometry (MS) and tandem MS (MS/MS) of linear polysaccharides modified at the reducing end is presented. Two polydisperse maltodextrins (1000 and 3000 Da) and a high molecular weight polydisperse dextran (6000 Da) were coupled with hexamethylenediamine (HMD). The coupling products were analyzed by nanoESI‐QTOF‐MS in the positive ion mode and MS/MS using collision‐induced dissociation (CID) at low energies. In the HMD‐M1000 mixture, the polysaccharide chains containing from 2 to 8 Glc residues were detected, while in HMD‐M3000 we identified a complete series of chains containing from 8 to 21 Glc moieties. The employed ESI conditions enhanced the detection of chains with up to 46 Glc residues in the HMD‐D6000 sample. By optimized MS/MS, HMD‐modified polysaccharides of 3, 4, 5, 12 and 46 degrees of polymerization yielded product ion spectra exhibiting the whole set of Y‐ and B‐fragment ions. The MS structural data were obtained within a few minutes of signal acquisition, with a sample consumption situating the analysis sensitivity in the picomolar range. Copyright © 2005 John Wiley & Sons, Ltd.
High‐precision, automated stable isotope analysis of atmospheric methane and carbon dioxide using continuous‐flow isotope‐ratio mass spectrometry
Authors: Fisher Rebecca , Lowry David , Wilkin Owen , Sriskantharajah Srimathy , Nisbet Euan G. 
Published: December 2005

AbstractSmall‐scale developments have been made to an off‐the‐shelf continuous‐flow gas chromatography/isotope‐ratio mass spectrometry (CF‐GC/IRMS) system to allow high‐precision isotopic analysis of methane (CH4) and carbon dioxide (CO2) at ambient concentrations. The repeatability (1σ) obtainable with this system is 0.05‰ for δ13C of CH4, 0.03‰ for δ13C of CO2, and 0.05‰ for δ18O of CO2 for ten consecutive analyses of a standard tank. An automated inlet system, which allows diurnal studies of CO2 and CH4 isotopes, is also described. The improved precision for CH4 analysis was achieved with the use of a palladium powder on quartz wool catalyst in the combustion furnace, which increased the efficiency of oxidation of CH4 to CO2. The automated inlet further improved the precision for both CH4 and CO2 analysis by keeping the routine constant. The method described provides a fast turn‐around in samples, with accurate, reproducible results, and would allow a long‐term continuous record of CH4 or CO2 isotopes at a site to be made, providing information about changing sources of the gases both seasonally and interannually. Copyright © 2005 John Wiley & Sons, Ltd.
On the asymptotics of fault probability in least‐recently‐used caching with Zipf‐type request distribution
Authors: Sugimoto Toyoaki , Miyoshi Naoto 
Published: December 2005

AbstractWe consider the least‐recently‐used cache replacement rule with a Zipf‐type page request distribution and investigate an asymptotic property of the fault probability with respect to an increase of cache size. We first derive the asymptotics of the fault probability for the independent‐request model and then extend this derivation to a general dependent‐request model, where our result shows that under some weak assumptions the fault probability is asymptotically invariant with regard to dependence in the page request process. In a previous study, a similar result was derived by applying a Poisson embedding technique, where a continuous‐time proof was given through some assumptions based on a continuous‐time modeling. The Poisson embedding, however, is just a technique used for the proof and the problem is essentially on a discrete‐time basis; thus, it is preferable to make assumptions, if any, directly in the discrete‐time setting. We consider a general dependent‐request model and give a direct discrete‐time proof under different assumptions. A key to the proof is that the numbers of requests for respective pages represent conditionally negatively associated random variables. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Existence, uniqueness, and algorithmic computation of general lilypond systems
Authors: Heveling Matthias , Last Günter 
Published: December 2005

AbstractThe lilypond system based on a locally finite subset φ of the Euclidean space ℝn is defined as follows. At time 0 every point of φ starts growing with unit speed in all directions to form a system of balls in which any particular ball ceases its growth at the instant that it collides with another ball. Based on a more formal definition of lilypond systems given in 1, we will prove that these systems exist and are uniquely determined. Our approach applies to the far more general setting, where φ is a locally finite subset of some space 𝕏 equipped with a pseudo‐metric d. We will also derive an algorithm approximating the system with at least linearly decreasing error. Several examples will illustrate our general results. © 2005 Wiley Periodicals, Inc. Random Struct. Alg., 2006
Impact of gender and generational differences in work values and attitudes in an Arab culture
Authors: Whiteoak John W. , Crawford Norman G. , Mapstone Richard H. 
Published: December 2005

AbstractIn this article, the work values and attitudes of 241 nationals from the United Arab Emirates are examined. Specifically, we assessed the impact of generational member‐ship and gender on the Islamic work ethic, individualism, attitudes toward women at work, and perceptions of the utility of wasta. Results suggest that values and attitudes held by people in the Middle East are changing on the one hand (e.g., individualism) but are also deeply held on the other (e.g., the Islamic work ethic). Results also suggest that the perceptions about the utility of wasta differ across generations. The implications of these findings and suggestions for future research are discussed. © 2006 Wiley Periodicals, Inc.
Preliminary evidence that gonadal hormones organize and activate disordered eating
Authors: KLUMP KELLY L. , GOBROGGE KYLE L. , PERKINS PATRICK S. , THORNE DAVID , SISK CHERYL L. , BREEDLOVE S. MARC 
Published: December 2005

Objective. Eating disorders are more common in females than in males. Gender differences may be due to organizational (i.e. prenatal) and activational (i.e. post-natal) gonadal hormone effects that influence sex differences in behavior. This preliminary set of studies examined these effects by investigating relationships between eating disorder symptoms, prenatal testosterone exposure, and adult levels of estrogen in women.Method. We examined organizational associations by investigating relationships between disordered eating and finger-length ratios, which are known to be somatic markers of prenatal testosterone exposure. Participants included 113 adult female twins drawn from the community. Disordered eating was assessed with the total score from the Minnesota Eating Behavior Survey (MEBS). Finger lengths were hand scored using a ruler and photocopies of both hands. We also investigated activational influences by examining associations between circulating levels of estradiol and disordered eating symptoms. Two independent samples of adult females (n's=24 and 25) drawn from the community were used for this study. Disordered eating was again assessed with the MEBS total score, while saliva samples were used for assessing estradiol.Results. Positive associations were found between disordered eating and both finger-length ratios and circulating estradiol levels.Conclusions. Findings suggest that lower levels of prenatal testosterone exposure and higher adult levels of estradiol are associated with increased eating disorder symptoms. We hypothesize that the relatively low level of testosterone before birth in females permits their brains to respond to estrogens at puberty, when the hormones activate the genes contributing to disordered eating in vulnerable girls.