bluuebunny/crossref_metadata_2025_split huggingface dataset:
Malignancies in patients with β‐thalassemia major and β‐thalassemia intermedia: A multicenter study in Iran
Authors: Karimi Mehran , Giti Rahil , Haghpanah Sezaneh , Azarkeivan Azita , Hoofar Hamid , Eslami Masoomeh 
Published: July 2009

AbstractBackgroundBeta thalassemia is one of the most common genetic disorders in the world. The aim of this study was to determine the frequency, characteristics, and pattern of malignancies in patients with beta thalassemia major (BTM) and beta thalassemia intermedia (BTI) in Iran.MethodsWe conducted a multicenter study via a retrospective chart review of patients with BTM and BTI between 2002 and 2007 in four thalassemia centers in Iran. A total of 4,630 records of patients with thalassemia were evaluated. Statistical analyses were done with SPSS software v. 15. P‐values <0.05 were considered significant.ResultsWe detected 11 patients with beta thalassemia who also had malignant disease. Five patients (45.4%) were diagnosed with lymphoma and five with leukemia. The proportion of patients with cancer was higher in those with BTI. Cancer was diagnosed in patients with thalassemia aged 0–39 years, but not in any of the older patients. In patients with thalassemia overall and in patients with BTI, the highest age‐specific rate of cancer incidence was seen in children <10 years old, whereas in the BTM group the highest incidence was observed in patients 20–29 years old. There were no statistically significant differences between patients with BTM and BTI and cancer regarding age, sex, splenectomy, hemoglobin, ferritin level, or malignancy type.ConclusionThe coexistence of malignancy and beta thalassemia is not rare. Any alarming signs and symptoms including worsening anemia, splenomegaly, or lymphadenopathy should be a motive for concern because these symptoms may signal malignant disease. Pediatr Blood Cancer 2009;53:1064–1067. © 2009 Wiley‐Liss, Inc.
Imaging and spectroscopic findings in meningioangiomatosis
Authors: Rokes Christopher , Ketonen Leena M. , Fuller Greg N. , Weinberg Jeffrey , Slopis John M. , Wolff Johannes E.A. 
Published: July 2009

AbstractMeningioangiomatosis (MA) is an uncommon brain tumor. The role of imaging techniques is underscored in cases where the tumor location makes resection (or even biopsy) dangerous. We report the case of a child with an MA tumor located deep in the right sylvian fissure. A computed tomography (CT) scan showed calcifications in a highly vascular lesion with surrounding edema. Magnetic resonance spectroscopy (MRS) showed a distinct choline (Cho) peak, which usually suggests a proliferating tumor. Fluorodeoxyglucose positron emission tomography (FDG‐PET) showed the lesion lacked hypermetabolic features. These radiological features should put MA in the differential diagnosis. Pediatr Blood Cancer 2009;53:672–674. © 2009 Wiley‐Liss, Inc.
Study of dual responsive poly[(maleilated dextran)‐graft‐(N‐isopropylacrylamide)] hydrogel nanoparticles: preparation, characterization and biological evaluation
Authors: Li Fei , Wu Hong , Fan Li , Zhang Haitao , Zhang Hui , Gu Chunhu 
Published: July 2009

AbstractBACKGROUND: Much interest has recently been shown in fundamental studies and technological developments of polymeric nanoparticles. Novel dual temperature‐ and pH‐sensitive stabilized nanoparticles composed of maleilated dextran (Dex‐MA) and N‐isopropylacrylamide (NIPAAm) were prepared and investigated to be used for the controlled release of 10‐hydroxycamptothecin.RESULTS: The resultant nanoparticles showed spherical geometry, with diameters ranging from 60 to 300 nm, the variation achieved by adjusting the composition ratio or the amounts of surfactant. The size of the nanoparticles increased and the zeta potential reversed with an increase of pH. Also, the lower critical solution temperature (LCST) decreased at pH = 3.0, but increased at pH = 6.0, which suggests that the LCST is dependent on pH. Drug release results obtained showed encapsulation and loading efficiencies were 62.9% and 0.82%, respectively. Cytotoxicity assay of this copolymer indicated no significant toxicity.CONCLUSION: Novel dual temperature‐ and pH‐sensitive Dex‐MA‐graft‐PNIPAAm nanoparticles may provide some advantages for anti‐cancer drug delivery due to a tunable LCST from 35 to 45 °C and controllable dimensions. These nanoscale materials could be excellent candidates for biotechnology and biomedical applications. Copyright © 2009 Society of Chemical Industry
Proteomic analysis of irregular, bullet‐shaped magnetosomes in the sulphate‐reducing magnetotactic bacterium Desulfovibrio magneticus RS‐1
Authors: Matsunaga Tadashi , Nemoto Michiko , Arakaki Atsushi , Tanaka Masayoshi 
Published: July 2009

AbstractRecent molecular studies on magnetotactic bacteria have identified a number of proteins associated with bacterial magnetites (magnetosomes) and elucidated their importance in magnetite biomineralisation. However, these analyses were limited to magnetotactic bacterial strains belonging to the α‐subclass of Proteobacteria. We performed a proteomic analysis of magnetosome membrane proteins in Desulfovibrio magneticus strain RS‐1, which is phylogenetically classified as a member of the δ‐Proteobacteria. In the analysis, the identified proteins were classified based on their putative functions and compared with the proteins from the other magnetotactic bacteria, Magnetospirillum magneticum AMB‐1 and M. gryphiswaldense MSR‐1. Three magnetosome‐specific proteins, MamA (Mms24), MamK, and MamM, were identified in strains RS‐1, AMB‐1, and MSR‐1. Furthermore, genes encoding ten magnetosome membrane proteins, including novel proteins, were assigned to a putative magnetosome island that contains subsets of genes essential for magnetosome formation. The collagen‐like protein and putative iron‐binding proteins, which are considered to play key roles in magnetite crystal formation, were identified as specific proteins in strain RS‐1. Furthermore, genes encoding two homologous proteins of Magnetococcus MC‐1 were assigned to a cryptic plasmid of strain RS‐1. The newly identified magnetosome membrane proteins might contribute to the formation of the unique irregular, bullet‐shaped crystals in this microorganism.
O‐Glycosylated 24 kDa human growth hormone has a mucin‐like biantennary disialylated tetrasaccharide attached at Thr‐60
Authors: Bustamante Juan J. , Gonzalez Leticia , Carroll Christopher A. , Weintraub Susan T. , Aguilar Roberto M. , Muñoz Jesus , Martinez Andrew O. , Haro Luis S. 
Published: July 2009

AbstractMS was used to characterize the 24 kDa human growth hormone (hGH) glycoprotein isoform and determine the locus ofO‐linked oligosaccharide attachment, the oligosaccharide branching topology, and the monosaccharide sequence. MALDI‐TOF/MS and ESI‐MS/MS analyses of glycosylated 24 kDa hGH tryptic peptides showed that this hGH isoform is a product of the hGH normal gene. Analysis of the glycoprotein hydrolysate by high‐performance anion‐exchange chromatography with pulsed amperometric detection and HPLC with fluorescent detection forN‐acetyl neuraminic acid (NeuAc) yielded the oligosaccharide composition (NeuAc2,N‐acetyl galactosamine1, Gal1). After β‐elimination to release the oligosaccharide from glycosylated 24 kDa hGH, collision‐induced dissociation of tryptic glycopeptide T6 indicated that there had been anO‐linked oligosaccharide attached to Thr‐60. The sequence and branching structure of the oligosaccharide were determined by ESI‐MS/MS analysis of tryptic glycopeptide T6. The mucin‐likeO‐oligosaccharide sequence linked to Thr‐60 begins withN‐acetyl galactosamine and branches in a bifurcated topology with one appendage consisting of galactose followed by NeuAc and the other consisting of a single NeuAc. The oligosaccharide moiety lies in the high‐affinity binding site 1 structural epitope of hGH that interfaces with both the growth hormone and the prolactin receptors and is predicted to sterically affect receptor interactions and alter the biological actions of hGH.
Cationic oligopeptides with the repeating sequence L‐lysyl‐L‐alanyl‐L‐alanine: conformational and thermal stability study using optical spectroscopic methods
Authors: Setnička Vladimír , Hlaváček Jan , Urbanová Marie 
Published: July 2009

AbstractThe infrared (IR), vibrational circular dichroism (VCD), and electronic circular dichroism (ECD) spectra of short cationic sequential peptides (L‐Lys‐L‐Ala‐L‐Ala)n (n = 1, 2, and 3) were measured over a range of temperatures (20–90 °C) in aqueous solution at near‐neutral pH values in order to investigate their solution conformations and thermally induced conformational changes. VCD spectra of all three oligopeptides measured in the amide I′ region indicate the presence of extended helical polyproline II (PPII)‐like conformation at room temperature. UV‐ECD spectra confirmed this conclusion. Thus, the oligopeptides adopt a PPII‐like conformation, independent of the length of the peptide chain. However, the optimized dihedral angles ϕ and ψ are within the range −82 to −107° and 143–154°, respectively, and differ from the canonical PPII values. At elevated temperatures, the observed intensity and bandshape variations in the VCD and ECD spectra show that the PPII‐like conformation of the Lys‐Ala‐Ala sequence is still preferred, being in equilibrium with an unordered conformer at near‐neutral pH values within the range of temperatures from 20 to 90 °C. This finding was obtained from analysis of the temperature‐dependent spectra using the singular value decomposition method. The study presents KAA‐containing oligopeptides as conformationally stable models of biologically important cationic peptides and proteins. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
Screening for glucose‐triggered modifications of glutathione
Authors: Jerić Ivanka , Horvat Štefica 
Published: July 2009

AbstractNonenzymatic protein glycation is caused by a Schiff's base reaction between the aldehyde groups of reducing sugars and the primary amines of proteins. These structures may undergo further Amadori rearrangement and free radical‐mediated oxidation to finally generate irreversible advanced glycation end products (AGEs). One of the factors known to modulate the glycation of proteins is glutathione, the most abundant nonprotein thiol tripeptide with the γ‐linkage, H‐Glu(Cys‐Gly‐OH)‐OH (GSH). Screening for products formed by GSH with D‐glucose is an essential step in understanding the participation of GSH in glycation (the Maillard) reaction. Under the conditions used in these studies we observed N‐(1‐deoxy‐D‐fructos‐1‐yl)‐pyroglutamic acid as the major glycation product formed in the mixtures of GSH and glucose in vitro. A RP HPLC/MS and tandem MS analyses of the GSH/glucose mixtures revealed that cleavage of the N‐terminal glutamic acid and the formation of pyroglutamic acid‐related Amadori product were accompanied by generation of Cys‐Gly‐derived Amadori and thiazolidine compounds. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.
A statistical model for the dependence between progression‐free survival and overall survival
Authors: Fleischer Frank , Gaschler‐Markefski Birgit , Bluhmki Erich 
Published: July 2009

AbstractAmong the surrogate endpoints for overall survival (OS) in oncology trials, progression‐free survival (PFS) is more and more taking the leading role. Although there have been some empirical investigations on the dependence structure between OS and PFS (in particular between the median OS and the median PFS), statistical models are almost non‐existing. This paper aims at filling this gap by introducing an easy‐to‐handle model based on exponential time‐to‐event distributions that describe the dependence structure between OS and PFS. Based on this model, explicit formulae for individual correlations are derived together with a lower bound for the correlation of OS and PFS, which is given by the fraction of the two medians for OS and PFS. Two methods on how to estimate the parameter of the model from real data are discussed. One method is based on a maximum‐likelihood estimator whereas the other method uses a plug‐in approach. Three examples from non‐small cell lung cancer are considered. In the first example, the parameters of the model are determined and the estimated survival curce is compared with the observed one. The second example explains how to obtain sample size estimates for OS based on assumptions on median PFS and OS. Finally, the third example provides a way of modelling and quantifying confounding effects that might explain a levelling of differences in OS although a difference in PFS is observed. Copyright © 2009 John Wiley & Sons, Ltd.
Incremental dynamic analysis of steel braced frames designed based on the first, second and third editions of the Iranian seismic code (standard no. 2800)
Authors: Asgarian Behrouz , Jalaeefar Ali 
Published: July 2009

AbstractIncremental dynamic analysis (IDA) is an emerging method in structural analysis which allows evaluation of seismic capacity and demand of structures through a series of nonlinear dynamic analyses using multiple scaled ground motion records.Seismic behaviour of concentrically braced frames designed based on the first, second and third revisions of the Iranian seismic code, standard no. 2800, has been evaluated through IDA in the present paper. Besides, a brief comparison is made between seismic behaviour of these frames, frames with different heights and different bracing types. Seismic capacity and limit states of such structures have been reviewed through the paper.The IDA results imply that frames designed with the first edition are seriously vulnerable and fail before reaching the acceleration levels predicted in the code. On the other hand, frames designed with the second and third editions, although behaving better, need partial reinforcement in some cases.Other results of this study show that chevron braced frames behave seismically better than X‐braced ones. Copyright © 2009 John Wiley & Sons, Ltd.
The effect of spatial dispersion of wind power plants on the curtailment of wind power in the Greek power supply system
Authors: Caralis George , Rados Kostas , Zervos Arthouros 
Published: July 2009

AbstractTo meet the national target of 29% for electricity production from renewable energy sources by 2020 in Greece, effective implementation of massive wind power installed capacity into the power supply system is required. In such a situation, the effective absorption of wind energy production is an important issue in a relatively small and weak power system such as that of Greece, which has limited existing interconnections with neighboring countries. The curtailment of wind power is sometimes necessary in autonomous systems with large wind energy penetration. The absorption or curtailment of wind power is strongly affected by the spatial dispersion of wind power installations. In the present paper, a methodology for estimating this effect is presented and applied for the power supply system of Greece. The method is based on probability theory, and makes use of wind forecasting models to represent the wind energy potential over any candidate area for future wind farm installations in the country. Moreover, technical constraints imposed by the power supply system management, the commitment of power plants and the load dispatch strategies are taken into account to maximize the wind energy penetration levels while ensuring reliable operation of the system. Representative wind power development scenarios are studied and evaluated. Results show that the spatial dispersion of wind power plants contributes beneficially to the wind energy penetration levels that can be accepted by the power system. Copyright © 2009 John Wiley & Sons, Ltd.
The minimization of a maximum‐norm functional subject to an elliptic PDE and state constraints
Authors: Prüfert U. , Schiela A. 
Published: July 2009

AbstractWe study the optimal control of a maximum‐norm objective functional subjected to an elliptic‐type PDE and pointwise state constraints. The problem is transformed into a problem where the non‐differentiable maximum‐norm in the functional will be replaced by a scalar variable and additional state constraints. This problem is solved by barrier methods. We will show the existence and convergence of the central path for a class of barrier functions. Numerical experiments complete the presentation.
Mathematical analysis of rotor shaft displacements in asynchronous machines; a critical speed or just a rotation of the orbit axis?
Authors: Werner U. 
Published: July 2009

AbstractThis paper presents a mathematical analysis of rotor shaft displacements in asynchronous machines caused by different types of rotor eccentricity. Based on a simplified rotor model, the theoretical coherence between electromagnetic, rotor dynamic, and the specific characteristics of sleeve bearings is shown. The orbits of the rotor mass and the shaft journal are mathematically described for each kind of eccentricity and the shaft displacement with respect to two virtual fixed sensors is derived. Based on this theoretical description and on a numerical example, the paper shows that focusing in a theoretical rotor dynamic analysis only on the calculated amplitudes in direction of two fixed sensor positions, may lead to wrong conclusions concerning the evaluation of resonances. The aim of this paper is, based on a simplified rotor model, to show the mathematical coherence concerning typical rotor eccentricities in asynchronous machines and to demonstrate the necessity to focus not only on the amplitudes relative to two fixed sensor positions, but to also consider the semi‐major axis of the calculated orbit and its angular position. The aim of the paper is not to replace a detailed finite element rotor dynamic analysis by a simplified analytical rotor model for predicting the real shaft vibrations. The intension is to prepare the basis for adopting the conclusions, derived from a simplified analytical model, into a more detailed rotor dynamic model – e.g. a finite element rotor dynamic model – and therefore to derive a more precise theoretical analysis of the real shaft displacements.
Numerical solution of multi‐term fractional differential equations
Authors: Katsikadelis J.T. 
Published: July 2009

AbstractA numerical solution method is presented for linear multi‐term fractional differential equations (FDEs) with variable coefficients. The presented method is based on the concept of the analog equation, which converts the multi‐term FDE into a single term FDE with a fictitious source (right hand inhomogeneous term). The fictitious source is established from the integral representation of the solution of the substitute single term equation. The constructed algorithms are stable. Their accuracy depends only on the truncation and round‐off errors, which, however, negligibly influence the accuracy. The method is demonstrated by the one‐ and two‐term FDEs. The developed algorithms apply also to systems of multi‐term FDEs. Several examples are presented, which demonstrate the efficiency and the accuracy of the proposed method. The method is straightforward extended to nonlinear FDEs.
Magnetoresistance in Sn-Doped In2O3Nanowires
Authors: Berengue Olívia M , Lanfredi AlexandreJC , Pozzi Livia P , Rey JoséFQ , Leite Edson R , Chiquito Adenilson J 
Published: July 2009

Abstract
In this work, we present transport measurements of individual Sn-doped In2O3nanowires as a function of temperature and magnetic field. The results showed a localized character of the resistivity at low temperatures as evidenced by the presence of a negative temperature coefficient resistance in temperatures lower than 77 K. The weak localization was pointed as the mechanism responsible by the negative temperature coefficient of the resistance at low temperatures.
Ferrocene‐Based Cationic Surfactants: Surface and Antimicrobial Properties
Authors: Hafiz Amal A. , Badawi A. M. , El‐Deeb F. I. , Soliman E. A. , El‐Awady M. Y. , Mohamed D. E. 
Published: July 2009

AbstractA novel series of ferrocenyl surfactants was synthesized by the reaction of ferrocene disulfonic acid with different primary and tertiary fatty amines to produce the corresponding ammonium salts Fc[SO3−+NH3(CH2)nCH3]2, where n = 9, 11, or 15 and Fc[SO3− +NH(CH3)2(CH2)nCH3]2, where n = 7 or 11, respectively, and where Fc = ferrocene. Chemical structures were confirmed by microelemental analysis, FTIR, and 1H NMR spectroscopy. The critical micelle concentration of each prepared surfactant was determined using equilibrium surface tension. Furthermore, air/water interface parameters including effectiveness (πCMC), efficiency (Pc20), maximum surface excess (Гmax), and minimum surface area (Amin) were determined at 30, 40, and 50 °C. Thermodynamic parameters (ΔG°, ΔS°, and ΔH°) for both micellization and adsorption processes were recorded. The new synthesized surfactants were screened as antimicrobial agents against different bacterial and fungal organisms.
Involvement of Lipids in Dimethoate‐Induced Inhibition of Testosterone Biosynthesis in Rat Interstitial Cells
Authors: Astiz Mariana , Hurtado de Catalfo Graciela E. , de Alaniz María J. T. , Marra Carlos Alberto 
Published: July 2009

AbstractThe mechanism involved in the inhibition of testosterone (Te) biosynthesis after a sub‐chronic exposure to low doses of dimethoate (D) was studied in rat interstitial cells (IC). Expression of COX‐2 in IC isolated from D‐treated rats increased by 44% over C data, while transcription of StAR decreased by approx. 50% and the expression of this protein was diminished by approximately 40%. PGE2 and PGF2α were increased by 61 and 78%, respectively. Te concentration decreased by 49% in IC homogenates. Concomitantly, plasma concentration of LH and FSH both increased. Araquidonate (ARA) and C22 fatty acyl chains in phospholipids from IC mitochondrial fraction decreased by approx. 30% after D treatment. Protein carbonyls, lipoperoxides and nitrite content increased while α‐tocopherol and the antioxidant capacity of the soluble cellular fraction decreased significantly. Stimulation with h‐CG 10 nM overnight failed to overcome the inhibition caused by D on both Te biosynthesis and 3β‐ and 17β‐hydroxysteroid dehydrogenases. Decreased Te biosynthesis may be attributed to (1) inhibition of StAR protein activity due to the stimulation of COX‐2 and the overproduction of PGF2α, (2) decreased stimulatory effect of ARA on StAR with a subsequent reduction in the availability of CHO for the androgenic pathway, and/or (3) indirect inhibition of steroidogenic enzymes by a lower transcriptional rate caused by elevated PGF2α. Rofecoxib administration prevents the deleterious effect(s) exerted by D.