bluuebunny/crossref_metadata_2025_split huggingface dataset:
The DRBEM solution of incompressible MHD flow equations
Authors: Bozkaya Nuray , Tezer‐Sezgin M. 
Published: September 2010

SUMMARYThis paper presents a dual reciprocity boundary element method (DRBEM) formulation coupled with an implicit backward difference time integration scheme for the solution of the incompressible magnetohydrodynamic (MHD) flow equations. The governing equations are the coupled system of Navier‐Stokes equations and Maxwell's equations of electromagnetics through Ohm's law. We are concerned with a stream function‐vorticity‐magnetic induction‐current density formulation of the full MHD equations in 2D. The stream function and magnetic induction equations which are poisson‐type, are solved by using DRBEM with the fundamental solution of Laplace equation. In the DRBEM solution of the time‐dependent vorticity and current density equations all the terms apart from the Laplace term are treated as nonhomogeneities. The time derivatives are approximated by an implicit backward difference whereas the convective terms are approximated by radial basis functions. The applications are given for the MHD flow, in a square cavity and in a backward‐facing step. The numerical results for the square cavity problem in the presence of a magnetic field are visualized for several values of Reynolds, Hartmann and magnetic Reynolds numbers. The effect of each parameter is analyzed with the graphs presented in terms of stream function, vorticity, current density and magnetic induction contours. Then, we provide the solution of the step flow problem in terms of velocity field, vorticity, current density and magnetic field for increasing values of Hartmann number. Copyright © 2010 John Wiley & Sons, Ltd.
A review of statistical methods for testing genetic anticipation: looking for an answer in Lynch syndrome
Authors: Boonstra Philip S. , Gruber Stephen B. , Raymond Victoria M. , Huang Shu‐Chen , Timshel Susanne , Nilbert Mef , Mukherjee Bhramar 
Published: September 2010

AbstractAnticipation, manifested through decreasing age of onset or increased severity in successive generations, has been noted in several genetic diseases. Statistical methods for genetic anticipation range from a simple use of the paired t‐test for age of onset restricted to affected parent‐child pairs to a recently proposed random effects model which includes extended pedigree data and unaffected family members [Larsen et al., 2009]. A naive use of the paired t‐test is biased for the simple reason that age of onset has to be less than the age at ascertainment (interview) for both affected parent and child, and this right truncation effect is more pronounced in children than in parents. In this study, we first review different statistical methods for testing genetic anticipation in affected parent‐child pairs that address the issue of bias due to right truncation. Using affected parent‐child pair data, we compare the paired t‐test with the parametric conditional maximum likelihood approach of Huang and Vieland [1997] and the nonparametric approach of Rabinowitz and Yang [1999] in terms of Type I error and power under various simulation settings and departures from the modeling assumptions. We especially investigate the issue of multiplex ascertainment and its effect on the different methods. We then focus on exploring genetic anticipation in Lynch syndrome and analyze new data on the age of onset in affected parent‐child pairs from families seen at the University of Michigan Cancer Genetics clinic with a mutation in one of the three main mismatch repair (MMR) genes. In contrast to the clinic‐based population, we re‐analyze data on a population‐based Lynch syndrome cohort, derived from the Danish HNPCC‐register. Both datasets indicate evidence of genetic anticipation in Lynch syndrome. We then expand our review to incorporate recently proposed statistical methods that consider family instead of affected pairs as the sampling unit. These prospective censored regression models offer additional flexibility to incorporate unaffected family members, familial correlation and other covariates into the analysis. An expanded dataset from the Danish HNPCC‐register is analyzed by this alternative set of methods. Genet. Epidemiol. 34:756‐768, 2010.© 2010 Wiley‐Liss, Inc.
Interferon lambda inhibits herpes simplex virus type I infection of human astrocytes and neurons
Authors: Li Jieliang , Hu Shuxian , Zhou Lin , Ye Li , Wang Xu , Ho Jie , Ho Wenzhe 
Published: September 2010

AbstractHerpes simplex virus Type I (HSV‐1) is a neurotropic virus that is capable of infecting not only neurons, but also microglia and astrocytes and can establish latent infection in the central nervous system (CNS). We investigated whether IFN lambda (IFN‐λ), a newly identified member of IFN family, has the ability to inhibit HSV‐1 infection of primary human astrocytes and neurons. Both astrocytes and neurons were found to be highly susceptible to HSV‐1 infection. However, upon IFN‐λ treatment, HSV‐1 replication in both astrocytes and neurons was significantly suppressed, which was evidenced by the reduced expression of HSV‐1 DNA and proteins. This IFN‐λ‐mediated action on HSV‐1 could be partially neutralized by antibody to IFN‐λ receptor. Investigation of the mechanisms showed that IFN‐λ treatment of astrocytes and neurons resulted in the upregulation of endogenous IFN‐α/β and several IFN‐stimulated genes (ISGs). To block IFN‐α/β receptor by a specific antibody could compromise the IFN‐λ actions on HSV‐1 inhibition and ISG induction. In addition, IFN‐λ treatment induced the expression of IFN regulatory factors (IRFs) in astrocytes and neurons. Furthermore, IFN‐λ treatment of astrocytes and neurons resulted in the suppression of suppressor of cytokine signaling 1 (SOCS‐1), a key negative regulator of IFN pathway. These data suggest that IFN‐λ possesses the anti‐HSV‐1 function by promoting Type I IFN‐mediated innate antiviral immune response in the CNS cells. © 2010 Wiley‐Liss, Inc.
Apathy and cortical atrophy in Alzheimer's disease
Authors: Tunnard C. , Whitehead D. , Hurt C. , Wahlund LO. , Mecocci P. , Tsolaki M. , Vellas B. , Spenger C. , Kłoszewska I. , Soininen H. , Lovestone S. , Simmons A. ,   on behalf of the AddNeuroMed Consortium
Published: September 2010

AbstractObjectivesApathy has been reported as the most prevalent behavioural symptom experienced in Alzheimer's disease (AD), associated with greater functional decline and caregiver distress. The aim of the current study was to investigate structural correlates of apathy in AD using magnetic resonance imaging (MRI) regional volume and regional cortical thickness measures.MethodsSemi‐structured interviews were conducted with 111 AD patients and their caregivers as part of the European multi‐centre study AddNeuroMed. Apathy was measured using the apathy domain of the Neuropsychiatric Inventory (NPI). All AD patients were scanned using a 1.5T MRI scanner and the images analysed using an automated analysis pipeline.ResultsWe found apathy to be the most prevalent neuropsychiatric symptom occurring in 57% of patients. Apathetic patients had significantly greater cortical thinning in left caudal anterior cingulate cortex (ACC) and left lateral orbitofrontal cortex (OFC), as well as left superior and ventrolateral frontal regions, than those without apathy symptoms.ConclusionsApathy is mediated by frontocortical structures but this is specific to the left hemisphere at least for patients in the mild to moderate stages of AD. Copyright © 2010 John Wiley & Sons, Ltd.
Osteoporosis in COPD outpatients based on bone mineral density and vertebral fractures
Authors: Graat-Verboom Lidwien , van den Borne Ben EEM , Smeenk Frank WJM , Spruit Martijn A , Wouters Emiel FM 
Published: September 2010

Abstract
One of the extrapulmonary effects of chronic obstructive pulmonary disease (COPD) is osteoporosis. Osteoporosis is characterized by a low bone mineral density (BMD) and microarchitectural deterioration. Most studies in COPD patients use dual-energy X-ray absorptiometry (DXA) only to determine osteoporosis; therefore, microarchitectural changes without a low BMD are missed. The aim of this study was to determine the prevalence and correlates of osteoporosis in COPD patients based on DXA, spinal X-rays, and combinations thereof. DXA and spinal X-rays were obtained and pulmonary function tests, body composition, 6-minute walking distance, medical history, and medication use were assessed in 255 clinically stable COPD outpatients of a large teaching hospital in the Netherlands. Half of all patients had radiologic evidence of osteoporosis. Combining the results of DXA with spinal X-rays augmented the proportion of COPD patients with osteoporosis compared with both methods separately. The prevalence of osteoporosis was not significantly different after stratification for Global Strategy for the Diagnosis, Management, and Prevention of COPD (GOLD) stage. Most patients with osteoporosis did not receive pharmacologic treatment. Age, body mass index (BMI), and parathyroid hormone (PTH) level were significant independent correlates for osteoporosis. Chest physicians should be aware of the high prevalence of osteoporosis in patients with COPD, even in the presence of a low GOLD score, as well as especially in elder COPD patients with a low BMI and/or an increased PTH level. © 2011 American Society for Bone and Mineral Research.
Modeling unimolecular reactions in photoelectron photoion coincidence experiments
Authors: Sztáray Bálint , Bodi Andras , Baer Tomas 
Published: September 2010

AbstractA computer program has been developed to model and analyze the data from photoelectron photoion coincidence (PEPICO) spectroscopy experiments. This code has been used during the past 12 years to extract thermochemical and kinetics information for almost a hundred systems, and the results have been published in over forty papers. It models the dissociative photoionization process in the threshold PEPICO experiment by calculating the thermal energy distribution of the neutral molecule, the energy distribution of the molecular ion as a function of the photon energy, and the resolution of the experiment. Parallel or consecutive dissociation paths of the molecular ion and also of the resulting fragment ions are modeled to reproduce the experimental breakdown curves and time‐of‐flight distributions. The latter are used to extract the experimental dissociation rates. For slow dissociations, either the quasi‐exponential fragment peak shapes or, when the mass resolution is insufficient to model the peak shapes explicitly, the center of mass of the peaks can be used to obtain the rate constants. The internal energy distribution of the fragment ions is calculated from the densities of states using the microcanonical formalism to describe consecutive dissociations. Dissociation rates can be calculated by the RRKM, SSACM or VTST rate theories, and can include tunneling effects, as well. Isomerization of the dissociating ions can also be considered using analytical formulae for the dissociation rates either from the original or the isomer ions. The program can optimize the various input parameters to find a good fit to the experimental data, using the downhill simplex algorithm. Copyright © 2010 John Wiley & Sons, Ltd.
High‐throughput UHPLC–MS/MS method for the detection, quantification and identification of fifty‐five anabolic and androgenic steroids in equine plasma
Authors: Guan Fuyu , Uboh Cornelius E. , Soma Lawrence R. , You Youwen , Liu Ying , Li Xiaoqing 
Published: September 2010

AbstractAnabolic and androgenic steroids (AASs) are synthetic substances related to the primary male sex hormone, testosterone. AASs can be abused in both human and equine sports and, thus, are banned by the International Olympic Committee and the Association of Racing Commissioners International (ARCI). Enforcement of the ban on the use of AASs in racehorses during competition requires a defensible and robust method of analysis. To address this requirement, a high‐throughput ultra high‐performance liquid chromatography–mass spectrometric (UHPLC–MS) method was developed for the detection, quantification and confirmation of 55 AASs in equine plasma. AASs were recovered from equine plasma samples by liquid–liquid extraction with methyl tert‐butyl ether (MTBE). Analytes were chromatographically separated on a sub‐2 µm particle size C18 column with a mobile phase gradient elution and detected by selected‐reaction monitoring (SRM) on a triple quadrupole mass spectrometer. AASs with isobaric precursor ions were either chromatographically resolved or mass spectrometrically differentiated by unique precursor‐to‐product ion transitions. A few of them that could not be resolved by both approaches were differentiated by intensity ratios of three major product ions. All the epimer pairs, testosterone and epitestosterone, boldenone and epiboldenone, nandrolone and epinandrolone, were chromatographically base‐line separated. The limit of detection and that of quantification was 50 pg/ml for most of the AASs, and the limit of confirmation was 100–500 pg/ml. Full product ion spectra of AASs at concentrations as low as 100–500 pg/ml in equine plasma were obtained using the triple quadrupole instrument, to provide complementary evidentiary data for confirmation. The method is sensitive and selective for the detection, quantification and confirmation of multiple AASs in a single analysis and will be useful in the fight against doping of racehorses with AASs. Copyright © 2010 John Wiley & Sons, Ltd.
Non‐covalent dimers of the lysine containing protonated peptide ions in gaseous state: electrospray ionization mass spectrometric study
Authors: Banerjee Shibdas , Mazumdar Shyamalava 
Published: September 2010

AbstractStudy of the non‐covalent molecular complexes in gas phase by electrospray ionization mass spectrometry (ESI‐MS) represents a promising strategy to probe the intrinsic nature of these complexes. ESI‐MS investigation of a series of synthetic octapeptides containing six alanine and two lysine residues differing only by their positions showed the formation of non‐covalent dimers, which were preserved in the gas phase. Unlike the monomers, the dimers were found to show only singly protonated state. The decrease in the solvent polarity from water to alcohol showed enhanced propensity of formation of the dimer indicating that the electrostatic interaction plays a crucial role to stabilize the dimer. Selective functionalization studies showed that ε‐NH2 of lysine and C‐terminal amide (CONH2) facilitate the dimerization through intermolecular hydrogen bonding network. Copyright © 2010 John Wiley & Sons, Ltd.
Chiral discrimination of β‐3‐homo‐amino acids using the kinetic method
Authors: Berkecz Róbert , Hyyryläinen Anna R. M. , Fülöp Ferenc , Péter Antal , Janáky Tamás , Vainiotalo Pirjo , Pakarinen Jaana M. H. 
Published: September 2010

AbstractChiral discrimination of seven enantiomeric pairs of β‐3‐homo‐amino acids was studied by using the kinetic method and trimeric metal‐bound complexes, with natural and unnatural α‐amino acids as chiral reference compounds and divalent metal ions (Cu2+ and Ni2+) as the center ions. The β‐3‐homo‐amino acids were selected for this study because, first of all, chiral discrimination of β‐amino acids has not been extensively studied by mass spectrometry. Moreover, these β‐3‐homo‐amino acids studied have different aromatic side chains. Thus, the emphasis was to study the effect of the side chain (electron density of the phenyl ring, as well as the difference between phenyl and benzyl side chains) for the chiral discrimination. The results showed that by the proper choice of a metal ion and a chiral reference compound, all seven enantiomeric pairs of β‐3‐homo‐amino acids could be differentiated. Moreover, it was noted that the β‐3‐homo‐amino acids with benzyl side chains provided higher enantioselectivity than the corresponding phenyl ones. However, increasing or decreasing the electron density of the aromatic ring by different substituents in both the phenyl and benzyl side chains had practically no role for chiral discrimination of β‐3‐homo‐amino acids studied. When copper was used as the central metal, the phenyl side chain containing reference molecules (S)‐2‐amino‐2‐phenylacetic acid (L‐Phg) and (S)‐2‐amino‐2‐(4‐hydroxyphenyl)‐acetic acid (L‐4′‐OHPhg) gave rise to an additional copper‐reduced dimeric fragment ion, [CuI(ref)(A)]+. The inclusion of this ion improved noticeably the enantioselectivity values obtained. Copyright © 2010 John Wiley & Sons, Ltd.
A Raman spectroscopic study of M2+M3+ sulfate minerals, römerite Fe2+Fe23+ (SO4)4· 14H2O and botryogen Mg2+Fe3+ (SO4)2(OH)·7H2O
Authors: Frost Ray L. , Palmer Sara J. , Čejka Jiří , Sejkora Jiří , Plášil Jakub , Jebavá Ivana , Keeffe Eloise C. 
Published: September 2010

AbstractThe mixed valency (M2+M3+) sulfate minerals, römerite Fe2+Fe23+ (SO4)4· 14H2O and botryogen Mg2+Fe3+ (SO4)2(OH)·7H2O have been studied using Raman spectroscopy. The Raman spectra of the two types of crystals proved very similar but not identical. The observation of two symmetric stretching modes confirmed the presence of the two nonequivalent sulfate units in the römerite structure. The observation of multiple bands in the antisymmetric stretching regions and in the bending regions proves that the symmetry of the sulfate anion is significantly reduced in the römerite structure. The number of Raman bands related to the (SO4)2− symmetric and antisymmetric vibrations supports the X‐ray single crystal structure conclusion that two symmetrically distinct S6+ are present in the structure of botryogen. Römerite is a mineral of environmental significance as it is commonly found in tailings and dumps. Copyright © 2010 John Wiley & Sons, Ltd.
Optical sectioning using single‐plane‐illumination Raman imaging
Authors: Barman Ishan , Tan Khay Ming , Singh Gajendra Pratap 
Published: September 2010

AbstractConfocal Raman imaging is widely used for optical sectioning of materials. However, for biological applications it often suffers from poor axial resolution, photodamage to the sample of interest, substrate interference, and long acquisition times. We have applied the principles of light sheet microscopy to Raman imaging and show for the first time that optically sectioned Raman images can be obtained in significantly lower acquisition times. Copyright © 2010 John Wiley & Sons, Ltd.
Verdigris pigment: a mixture of compounds. Input from Raman spectroscopy
Authors: San Andrés M. , de la Roja J. M. , Baonza V. G. , Sancho N. 
Published: September 2010

AbstractThe reproduction of an old recipe to obtain the pigment known as verdigris leads to a complex mixture of hydrated copper(II) acetates containing neutral verdigris and two varieties of basic verdigris. Since the characterization of such mixture is complicated by the lack of reference standards, we complemented our Raman measurements with Fourier transform infrared (FTIR) and X‐ray diffraction (XRD) experiments to perform our analysis, which has been compared with available studies. The spectral analysis allowed us to distinguish the different verdigris varieties, with stretching and bending wavenumbers assigned to the following chemical groups: OH groups (OHhydroxyand OHH2O) (3600–3050 cm−1), CuO bonds (CuO and CuOH) (1000–450 cm−1) and those corresponding to the acetate group (CH3COO−), i.e. (CH3: 3000–2850 cm−1) and (COO−: 1600–1400 cm−1and 700–600 cm−1). Both wavenumbers and Raman intensities were used to quantify the relative compositions of the mixture components. Copyright © 2010 John Wiley & Sons, Ltd.
Electro membrane extraction combined with capillary electrophoresis for the determination of amlodipine enantiomers in biological samples
Authors: Nojavan Saeed , Fakhari Ali Reza 
Published: September 2010

AbstractElectro membrane extraction as a new microextraction method was applied for the extraction of amlodipine (AM) enantiomers from biological samples. During the extraction time of 15 min, AM enantiomers migrated from a 3 mL sample solution, through a supported liquid membrane into a 20 μL acceptor solution presented inside the lumen of the hollow fiber. The driving force of the extraction was 200 V potential, with the negative electrode in the acceptor solution and the positive electrode in the sample solution. 2‐Nitro phenyl octylether was used as the supported liquid membrane. Using 10 mM HCl as background electrolyte in the sample and acceptor solution, enrichment up to 124 times was achieved. Then, the extract was analyzed using CD modified CE method for separation of AM enantiomers. Best results were achieved using a phosphate running buffer (100 mM, pH 2.0) containing 5 mM hydroxypropyl‐α‐CD. The range of quantitation for both enantiomers was 10–500 ng/mL. Intra‐ and interday RSD (n=6) were less than 14%. The limits of quantitation and detection for both enantiomers were 10 and 3 ng/mL respectively. Finally, this procedure was applied to determine the concentration of AM enantiomers in plasma and urine samples.
Intra‐organ biodistribution of gold nanoparticles using intrinsic two‐photon‐induced photoluminescence
Authors: Park Jaesook , Estrada Arnold , Schwartz Jon A. , Diagaradjane Parmeswaran , Krishnan Sunil , Dunn Andrew K. , Tunnell James W. 
Published: September 2010

AbstractBackground and ObjectivesGold nanoparticles (GNPs) such as gold nanoshells (GNSs) and gold nanorods (GNRs) have been explored in a number of in vitro and in vivo studies as imaging contrast and cancer therapy agents due to their highly desirable spectral and molecular properties. While the organ‐level biodistribution of these particles has been reported previously, little is known about the cellular level or intra‐organ biodistribution. The objective of this study was to demonstrate the use of intrinsic two‐photon‐induced photoluminescence (TPIP) to study the cellular level biodistribution of GNPs.Study Design/Materials and MethodsTumor xenografts were created in 27 male nude mice (Swiss nu/nu) using HCT 116 cells (CCL‐247; American Type Culture Collection (ATCC), Manassas, VA, human colorectal cancer cell line). GNSs and GNRs were systemically injected 24 hours prior to tumor harvesting. A skin flap with the tumor was excised and sectioned as 8 µm thick tissues for imaging GNPs under a custom‐built multiphoton microscope. For multiplexed imaging, nuclei, cytoplasm, and blood vessels were demonstrated by hematoxylin and eosin (H&E) staining, YOYO‐1 iodide staining, and CD31‐immunofluorescence staining.ResultsDistribution features of GNPs at the tumor site were determined from TPIP images. GNSs and GNRs had a heterogeneous distribution with higher accumulation at the tumor cortex than tumor core. GNPs were also observed in unique patterns surrounding the perivascular region. While most GNSs were confined at the distance of approximately 400 µm inside the tumor edge, GNRs were shown up to 1.5 mm penetration inside the edge.ConclusionsWe have demonstrated the use of TPIP imaging in a multiplexed fashion to image both GNPs and nuclei, cytoplasm, or vasculature simultaneously. We also confirmed that TPIP imaging enabled visualization of GNP distribution patterns within the tumor and other critical organs. These results suggest that direct luminescence‐based imaging of metal nanoparticles holds a valuable and promising position in understanding the accumulation kinetics of GNPs. In addition, these techniques will be increasingly important as the use of these particles progress to human clinical trials where standard histopathology techniques are used to analyze their effects. Lasers Surg. Med. 42:630–639, 2010. © 2010 Wiley‐Liss, Inc.