bluuebunny/crossref_metadata_2025_split huggingface dataset:
The application of Fe3O4 nanoparticles in cancer research: A new strategy to inhibit drug resistance
Authors: Wang Xuemei , Zhang Renyun , Wu Chunhui , Dai Yongyuan , Song Min , Gutmann Sebastian , Gao Feng , Lv Gang , Li Jingyuan , Li Xiaomao , Guan Zhiqun , Fu Degang , Chen Baoan 
Published: October 2006

AbstractAlthough much effort has been extended to the efficient cancer therapies, the drug resistance is still a major obstacle in cancer chemotherapeutic treatments. Almost 90% of the cancer therapy failure is caused by the relative problems. Recently, the application of drug coated polymer nanospheres and nanoparticles to inhibit the related drug resistance has attracted much attention. In this report, we have explored a novel strategy to inhibit the multidrug resistance of the targeted tumor cells by combining the unique properties of tetraheptylammonium capped Fe3O4 magnetic nanoparticles with the drug accumulation of anticancer drug daunorubicin. Our results of confocal fluorescence and atomic force microscopy (AFM) as well as electrochemical studies demonstrate the remarkable synergistic effect of Fe3O4 nanoparticles on drug uptake of daunorubicin in leukemia K562 cells. These observations indicate that the interaction between the magnetic nanoparticles Fe3O4 and biologically active molecules on the membrane of leukemia cell lines may contribute to their beneficial effect on cellular uptake so that the synergistic enhanced effect of magnetic nanoparticles Fe3O4 on drug uptake of drug resistance leukemia K562 cells could be observed upon application of the Fe3O4 nanoparticles. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Stability of passivated 316L stainless steel oxide films for cardiovascular stents
Authors: Shih Chun‐Che , Shih Chun‐Ming , Chou Kuang‐Yi , Lin Shing‐Jong , Su Yea‐Yang 
Published: October 2006

AbstractPassivated 316L stainless steel is used extensively in cardiovascular stents. The degree of chloride ion attack might increase as the oxide film on the implant degrades from exposure to physiological fluid. Stability of 316L stainless steel stent is a function of the concentration of hydrated and hydrolyated oxide concentration inside the passivated film. A high concentration of hydrated and hydrolyated oxide inside the passivated oxide film is required to maintain the integrity of the passivated oxide film, reduce the chance of chloride ion attack, and prevent any possible leaching of positively charged ions into the surrounding tissue that accelerate the inflammatory process. Leaching of metallic ions from corroded implant surface into surrounding tissue was confirmed by the X‐ray mapping technique. The degree of thrombi weight percentage [Wao: (2.1 ± 0.9)%; Wep: (12.5 ± 4.9)%, p < 0.01] between the amorphous oxide (AO) and the electropolishing (EP) treatment groups was statistically significant in ex‐vivo extracorporeal thrombosis experiment of mongrel dog. The thickness of neointima (Tao: 100 ± 20 μm; Tep: 500 ± 150 μm, p < 0.01) and the area ratio of intimal response at 4 weeks (ARao: 0.62 ± 0.22; ARep: 1.15 ± 0.42, p < 0.001) on the implanted iliac stents of New Zealand rabbit could be a function of the oxide properties. © 2006 Wiley Periodicals, Inc. J Biomed Mater Res, 2006
Perfect coloring and linearly χ‐bound P6‐free graphs
Authors: Choudum S. A. , Karthick T. , Shalu M. A. 
Published: October 2006

AbstractWe derive decomposition theorems for P6, K1 + P4‐free graphs, P5, K1 + P4‐free graphs and P5, K1 + C4‐free graphs, and deduce linear χ‐binding functions for these classes of graphs (here, Pn (Cn) denotes the path (cycle) on n vertices and K1 + G denotes the graph obtained from G by adding a new vertex and joining it with every vertex of G). Using the same techniques, we also obtain an optimal χ‐binding function for P5, C4‐free graphs which is an improvement over that given in [J. L. Fouquet, V. Giakoumakis, F. Maire, and H. Thuillier, 1995, Discrete Math, 146, 33–44.]. © 2006 Wiley Periodicals, Inc. J Graph Theory 54: 293–306, 2007
Differentiation of human mesenchymal stem cells and articular chondrocytes: Analysis of chondrogenic potential and expression pattern of differentiation‐related transcription factors
Authors: Karlsson Camilla , Brantsing Camilla , Svensson Teresia , Brisby Helena , Asp Julia , Tallheden Tommi , Lindahl Anders 
Published: October 2006

AbstractMesenchymal stem cells (MSCs) are a candidate for replacing chondrocytes in cell‐based repair of cartilage lesions. However, it has not been clarified if these cells can acquire the hyaline phenotype, and whether chondrocytes and MSCs show the same expression patterns of critical control genes in development. In order to study this, articular chondrocytes and iliac crest derived MSCs were allowed to differentiate in pellet mass cultures. Gene expression of markers for the cartilage phenotype, helix‐loop‐helix (HLH) transcription factors, and chondrogenic transcription factors were analyzed by real‐time PCR. Matrix production was assayed using biochemical analysis for hydroxyproline, glycosaminoglycans, and immunohistochemistry for collagen types I and II. Significantly decreased expression of collagen type I was accompanied by increased expression of collagen types IIA and IIB during differentiation of chondrocytes, indicating differentiation towards a hyaline phenotype. Chondrogenesis in MSCs on the other hand resulted in up‐regulation of collagen types I, IIA, IIB, and X, demonstrating differentiation towards cartilage of a mixed phenotype. Expression of HES1 increased significantly during chondrogenesis in chondrocytes while expression in MSCs was maintained at a low level. The HLH gene HES5 on the other hand was only detected in chondrocytes. Expression of ID1 decreased significantly in chondrocytes while the opposite was seen in MSCs. These findings suggest that chondrocytes and MSCs differentiated and formed different subtypes of cartilage, the hyaline and a mixed cartilage phenotype, respectively. Differentially regulated HLH genes indicated the possibility for HLH proteins in regulating chondrogenic differentiation. This information is important to understand the potential use of MSCs in cartilage repair. © 2006 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 25:152–163, 2007
Klippel‐Feil syndrome in an Early Hungarian Period juvenile skeleton from Austria
Authors: Pany D. , Teschler‐Nicola M. 
Published: October 2006

AbstractThe excellently preserved skeleton of a juvenile from the Early Hungarian Period (10th century AD), recently excavated in Gnadendorf (Lower Austria), displays typical symptoms of Type II congenital ‘Klippel‐Feil syndrome’ (KFS): fused cervical vertebrae 2 and 3, and fused thoracic vertebrae 2 and 3. Other features observed in this skeleton clinically reported for KFS include a basilar impression and a spina bifida occulta. The bilateral symmetrical hypoplasia of the basilar part of the occipital bone is probably also linked to this syndrome, as well as the constricted external acoustic meati, which almost certainly led to hearing impairment. A cranial lesion and its possible consequences are discussed in the context of the specific KFS alterations. Copyright © 2006 John Wiley & Sons, Ltd.
Genomic aberrations are rare in urothelial neoplasms of patients 19 years or younger
Authors: Wild PJ , Giedl J , Stoehr R , Junker K , Boehm S , van Oers JMM , Zwarthoff EC , Blaszyk H , Fine SW , Humphrey PA , Dehner LP , Amin MB , Epstein JI , Hartmann A 
Published: October 2006

AbstractUrothelial neoplasms in patients 19 years of age or younger are rare, and the data regarding clinical outcome are conflicting. Molecular data are not available. Urothelial tumours from 14 patients aged 4 to 19 years were analysed, including FGFR3 and TP53 mutation screening, comparative genomic hybridization (CGH), UroVysion FISH analysis, polymerase chain reaction for human papillomavirus (HPV), microsatellite analysis using the NIH consensus panel for detection of microsatellite instability (MSI) and six markers for loss of heterozygosity on chromosome arms 9p, 9q, and 17p and immunohistochemistry for TP53, Ki‐67, CK20 and the mismatch repair proteins (MRPs) hMSH2, hMLH1, and hMSH6. Based on the 2004 WHO classification, one urothelial papilloma, seven papillary urothelial neoplasms of low malignant potential (PUNLMPs), five low‐grade, and one high‐grade papillary urothelial carcinoma were included. No multifocal tumours were found and recurrence was seen in only one patient with a urothelial papilloma. All patients were alive with no evidence of disease at a median follow‐up of 3.0 years. We found no mutations in FGFR3, deletions of chromosome arms 9p, 9q or 17p, MSI or MRP loss, or HPV positivity in any of the patients. Three cases showed chromosome alterations in CGH analyses, urothelial dedifferentiation with CK20 overexpression, or aneuploidy, and one TP53 mutation with TP53 overexpression was found. Urothelial neoplasms in people younger than 20 years are predominantly low grade and are associated with a favourable clinical outcome. Genetic alterations frequently seen in older adults are extremely rare in young patients. Urothelial neoplasms in children and young adults appear to be biologically distinct and lack genetic instability in most cases. Copyright © 2006 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.
Conjunctival melanoma in a six‐year‐old female
Authors: Polat Aziz , Yıldırım Cem , Işık Balcı Yasemin , İnce Tülay , Bir Ferda , Demirkan Neşe , Bican Mevlüt 
Published: October 2006

AbstractConjunctival melanoma (CM) is a highly malignant tumor that derives from melanocytes and is rarely seen in children. This report describes a 6‐year‐old female diagnosed with CM. Pediatr Blood Cancer 2008;50:384–386. © 2006 Wiley‐Liss, Inc.
Protective effects of Ginkgo biloba extract against mercury(II)‐induced cardiovascular oxidative damage in rats
Authors: Tunali‐Akbay Tugba , Sener Goksel , Salvarli Hanife , Sehirli Ozer , Yarat Aysen 
Published: October 2006

AbstractThis study was designed to determine the possible protective effect of Ginkgo biloba extract (EGb) against Hg II‐induced oxidative damage and also thromboplastic activity in the aorta and heart tissues. Wistar albino rats of either sex (200–250 g) were divided into four groups. Rats were injected intraperitoneally with (1) control (C) group: 0.9% NaCl; (2) EGb group: Ginkgo biloba extract (Abdi Ibrahim Pharmaceutical Company, Istanbul, Turkey) at a dose of 50 mg/kg/day; (3) Hg group: a single dose of 5 mg/kg mercuric chloride (HgCl2); and (4) Hg + EGb group: First day EGb at a dose of 50 mg/kg/day, i.p., 1 hour after HgCl2 (5 mg/kg) injection; following four days EGb at a dose 50 mg/kg/day, i.p. After decapitation of the rats, trunk blood was obtained and serum tumor necrosis factor‐α (TNF‐α), lactate dehydrogenase (LDH) activity, and malondialdehyde (MDA) and glutathione (GSH) levels were analysed. In the aorta and heart tissues total protein, MDA, GSH levels and thromboplastic activity were determined. The results revealed that HgCl2 induced oxidative tissue damage, as evidenced by increases in MDA levels and decreased GSH levels both in serum and tissue samples. Thromboplastic activity was increased significantly following Hg administration, which verifies the cardiotoxic effects of HgCl2. Serum LDH and TNF‐α were elevated in the Hg group compared with the control group. Since EGb treatment reversed these responses, it seems likely that Ginkgo biloba extract can protect the cardiovascular tissues against HgCl2‐induced oxidative damage. Copyright © 2006 John Wiley & Sons, Ltd.
Innovative packaging for minimally processed fruits
Authors: Avella M. , Bruno G. , Errico M. E. , Gentile G. , Piciocchi N. , Sorrentino A. , Volpe M. G. 
Published: October 2006

AbstractNovel nanocomposite films for use in the packaging of foods ready for consumption and based on isotactic polypropylene (iPP) filled with innovative calcium carbonate nanoparticles, as well as having spherical and elongated shape and covered with appropriate coating agent able to better interact with the iPP matrix, were prepared and characterized. Morphological, thermal, mechanical and transport characterizations on nanocomposite films were performed. The results evidenced a good dispersion of the nanofiller into the polymeric matrix as well as an increase in mechanical parameters such as modulus. Moreover, a drastic reduction of iPP permeability to both oxygen and carbon dioxide was also recorded. Migration tests evidenced that these nanocomposites are suitable for food packaging applications. Finally, the analysis of some shelf‐life parameters carried out on packaged minimally processed apples showed that these materials are able to preserve for up to 10 days apple slices, limiting oxidation processes and microbiological growth. Copyright © 2006 John Wiley & Sons, Ltd.
Regression analysis of failure time data with informative interval censoring
Authors: Zhang Zhigang , Sun Liuquan , Sun Jianguo , Finkelstein Dianne M. 
Published: October 2006

AbstractInterval censoring arises when a subject misses prescheduled visits at which the failure is to be assessed. Most existing approaches for analysing interval‐censored failure time data assume that the censoring mechanism is independent of the true failure time. However, there are situations where this assumption may not hold. In this paper, we consider such a situation in which the dependence structure between the censoring variables and the failure time can be modelled through some latent variables and a method for regression analysis of failure time data is proposed. The method makes use of the proportional hazards frailty model and an EM algorithm is presented for estimation. Finite sample properties of the proposed estimators of regression parameters are examined through simulation studies and we illustrate the method with data from an AIDS study. Copyright © 2006 John Wiley & Sons, Ltd.
Accounting for expected attrition in the planning of community intervention trials
Authors: Taljaard Monica , Donner Allan , Klar Neil 
Published: October 2006

AbstractTrials in which intact communities are the units of randomization are increasingly being used to evaluate interventions which are more naturally administered at the community level, or when there is a substantial risk of treatment contamination. In this article we focus on the planning of community intervention trials in which k communities (for example, medical practices, worksites, or villages) are to be randomly allocated to each of an intervention and a control group, and fixed cohorts of m individuals enrolled in each community prior to randomization. Formulas to determine k or m may be obtained by adjusting standard sample size formulas to account for the intracluster correlation coefficient ρ. In the presence of individual‐level attrition however, observed cohort sizes are likely to vary. We show that conventional approaches of accounting for potential attrition, such as dividing standard sample size formulas by the anticipated follow‐up rate π or using the average anticipated cohort size mπ, may, respectively, overestimate or underestimate the required sample size when cluster follow‐up rates are highly variable, and m or ρ are large. We present new sample size estimation formulas for the comparison of two means or two proportions, which appropriately account for variation among cluster follow‐up rates. These formulas are derived by specifying a model for the binary missingness indicators under the population‐averaged approach, assuming an exchangeable intracluster correlation coefficient, denoted by τ. To aid in the planning of future trials, we recommend that estimates for τ be reported in published community intervention trials. Copyright © 2006 John Wiley & Sons, Ltd.
Multidisciplinary investigation of eco‐industrial parks
Authors: Haskins Cecilia 
Published: October 2006

AbstractSince the revelation of an industrial symbiosis in Denmark, researchers have attempted to draw out the patterns of success and replicate the Kalundborg model in brown‐ and greenfield eco‐industrial parks. Establishment of these parks is seen to offer hope to both industrialized and developing nations for achieving sustainable development objectives. This paper reviews the relevant literature and considers the relative usefulness of industrial ecology, systems science, and industrial network theory for understanding eco‐industrial parks. This multidisciplinary approach considers knowledge‐sharing techniques such as pattern languages as a mechanism for sharing best results. The paper closes with suggestions for the direction of further research. © 2006 Wiley Periodicals, Inc. Syst Eng 9:313–330, 2006
Modeling Culture Profiles of the Heterocystous N2‐Fixing Cyanobacterium Anabaenaflos‐aquae
Authors: Pinzon Neissa M. , Ju Lu‐Kwang 
Published: October 2006

AbstractHeterocyst differentiation is a unique feature of nitrogen‐fixing cyanobacteria, potentially important for photobiological hydrogen production. Despite the significant advances in genetic investigation on heterocyst differentiation, there were no quantitative culture‐level models that describe the effects of cellular activities and cultivation conditions on the heterocyst differentiation. Such a model was developed in this study, incorporating photosynthetic growth of vegetative cells, heterocyst differentiation, self‐shading effect on light penetration, and nitrogen fixation. The model parameters were determined by fitting experimental results from the growth of the heterocystous cyanobacterium Anabaena flos‐aquae CCAP 1403/13f in media without and with different nitrate concentrations and under continuous illumination of white light at different light intensities (2, 5, 10, 17, 20 and 50 μE m−2 s−1). The model describes the experimental profiles well and gives reasonable predictions even for the transition of growth from that on external N source to that via nitrogen fixation, responding to the change in external N concentrations. The significance and implications of the best‐fit values of the model parameters are discussed.
Structural and kinetic analyses of the H121A mutant of cholesterol oxidase
Authors: Lim Louis , Molla Gianluca , Guinn Nicole , Ghisla Sandro , Pollegioni Loredano , Vrielink Alice 
Published: October 2006

Cholesterol oxidase is a monomeric flavoenzyme that catalyses the oxidation of cholesterol to cholest-5-en-3-one followed by isomerization to cholest-4-en-3-one. The enzyme from Brevibacterium sterolicum contains the FAD cofactor covalently bound to His121. It was previously demonstrated that the H121A substitution results in a ≈100 mV decrease in the midpoint redox potential and a ≈40-fold decrease in turnover number compared to wild-type enzyme [Motteran, Pilone, Molla, Ghisla and Pollegioni (2001) Journal of Biological Chemistry 276, 18024–18030]. A detailed kinetic analysis of the H121A mutant enzyme shows that the decrease in turnover number is largely due to a corresponding decrease in the rate constant of flavin reduction, whilst the re-oxidation reaction is only marginally altered and the isomerization reaction is not affected by the substitution and precedes product dissociation. The X-ray structure of the mutant protein, determined to 1.7 Å resolution (1 Å≡0.1 nm), reveals only minor changes in the overall fold of the protein, namely: two loops have slight movements and a tryptophan residue changes conformation by a rotation of 180° about χ1 compared to the native enzyme. Comparison of the isoalloxazine ring moiety of the FAD cofactor between the structures of the native and mutant proteins shows a change from a non-planar to a planar geometry (resulting in a more tetrahedral-like geometry for N5). This change is proposed to be a major factor contributing to the observed alteration in redox potential. Since a similar distortion of the flavin has not been observed in other covalent flavoproteins, it is proposed to represent a specific mode to facilitate flavin reduction in covalent cholesterol oxidase.
Simulated maximum likelihood method for estimating kinetic rates in gene expression
Authors: Tian Tianhai , Xu Songlin , Gao Junbin , Burrage Kevin 
Published: October 2006

AbstractMotivation: Kinetic rate in gene expression is a key measurement of the stability of gene products and gives important information for the reconstruction of genetic regulatory networks. Recent developments in experimental technologies have made it possible to measure the numbers of transcripts and protein molecules in single cells. Although estimation methods based on deterministic models have been proposed aimed at evaluating kinetic rates from experimental observations, these methods cannot tackle noise in gene expression that may arise from discrete processes of gene expression, small numbers of mRNA transcript, fluctuations in the activity of transcriptional factors and variability in the experimental environment.Results: In this paper, we develop effective methods for estimating kinetic rates in genetic regulatory networks. The simulated maximum likelihood method is used to evaluate parameters in stochastic models described by either stochastic differential equations or discrete biochemical reactions. Different types of non-parametric density functions are used to measure the transitional probability of experimental observations. For stochastic models described by biochemical reactions, we propose to use the simulated frequency distribution to evaluate the transitional density based on the discrete nature of stochastic simulations. The genetic optimization algorithm is used as an efficient tool to search for optimal reaction rates. Numerical results indicate that the proposed methods can give robust estimations of kinetic rates with good accuracy.Contact: tian@maths.uq.edu.au
Recovering metabolic pathways via optimization
Authors: Beasley John E. , Planes Francisco J. 
Published: October 2006

AbstractMotivation: A metabolic pathway is a coherent set of enzyme catalysed biochemical reactions by which a living organism transforms an initial (source) compound into a final (target) compound. Some of the different metabolic pathways adopted within organisms have been experimentally determined. In this paper, we show that a number of experimentally determined metabolic pathways can be recovered by a mathematical optimization model.Contact: john.beasley@brunel.ac.uk