bluuebunny/crossref_metadata_2025_split huggingface dataset:
Component Mode Synthesis of a Vehicle System Model Using the Fictitious Mass Method
Authors: Karpel M. , Moulin B. , Feldgun V. 
Published: January 2007

Abstract
A new procedure for dynamic analysis of complex structures, based on the fictitious-mass component mode synthesis method, is presented. Normal modes of separate components are calculated by finite-element analysis with the interface coordinates loaded with fictitious masses that generate local boundary deformations in the low-frequency modes. The original fictitious-mass method is extended to include three types of component interconnections: displacement constraints, connection elements, and structural links. The connection elements allow the introduction of springs and dampers between the interface points without adding structural degrees of freedom. The structural links facilitate the inclusion the discrete finite-element representation of typically small components in the coupling equations. This allows a convenient treatment of loose elements and the introduction of nonlinear effects and parametric studies in subsequent analyses. The new procedure is demonstrated with the structural model of a typical vehicle with four major substructures and a relatively large number of interface coordinates. High accuracy is obtained in calculating the natural frequencies and modes of the assembled structure and the separate components with the fictitious masses removed. Dynamic response analysis of the vehicle travelling over a rough road, performed by modal coupling, is in excellent agreement with that performed for the full model.
Vibration of Delaminated Composite Laminates: A
Review
Authors: Della Christian N. , Shu Dongwei 
Published: January 2007

Abstract
Fiber reinforced composite laminates are increasingly replacing traditional metallic materials. The manufacturing process and service of the composite laminates frequently lead to delamination. Vibration analysis is an integral part of most engineering structures. In the present article we provide a relevant survey on the various analytical models and numerical analyses for the free vibration of delaminated composites. A basic understanding of the influence of the delamination on the natural frequencies and the mode shapes of composite laminates is presented. In addition, other factors affecting the vibration of the delaminated composites are discussed. Particular attention is given to composite laminates having piezoelectric sensors and actuators, and ones subjected to axial loadings.
Thermally Induced Convective Movements in a Standard Experimental Model for Characterization of Lesions Prior to Radiofrequency Functional Neurosurgery
Authors: Wren Joakim , Loyd Dan , Andersson Urban , Karlsson Rolf 
Published: January 2007

AbstractExperimental exploration of equipment for stereotactic functional neurosurgery based on heating induced by radio-frequency current is most often carried out prior to surgery in order to secure a correct function of the equipment. The experiments are normally conducted in an experimental model including an albumin solution in which the treatment electrode is submerged, followed by a heating session during which a protein clot is generated around the electrode tip. The clot is believed to reflect the lesion generated in the brain during treatment. It is thereby presupposed that both the thermal and electric properties of the model are similar to brain tissue. This study investigates the presence of convective movements in the albumin solution using laser Doppler velocimetry. The result clearly shows that convective movements that depend on the time dependent heating characteristics of the equipment arise in the solution upon heating. The convective movements detected show a clear discrepancy compared with the in vivo situation that the experimental model tries to mimic; both the velocity (maximum velocity of about 5mm∕s) and mass flux are greater in this experimental setting. Furthermore the flow geometry is completely different since only a small fraction of the tissue surrounding the electrode in vivo consists of moving blood, whereas the entire surrounding given by the albumin solution in the experimental model is moving. Earlier investigations by our group (Eriksson et al., 1999, Med. Biol. Eng. Comput. 37, pp. 737–741; Wren, 2001, Ph.D. thesis; and Wren et al., 2001, Med. Biol. Eng. Comput. 39, pp. 255–262) indicate that the heat flux is an essential parameter for the lesion growth and final size, and that presence of convective movements in the model might substantially increase the heat flux. Thus, convective movements of the magnitude presented here will very likely underestimate the size of the brain lesion, a finding that definitely should be taken into consideration when using the model prior to patient treatment.
Nonlinear Anisotropic Stress Analysis of Anatomically Realistic
Cerebral Aneurysms
Authors: Ma Baoshun , Lu Jia , Harbaugh Robert E , Raghavan Madhavan L. 
Published: January 2007

Abstract
Background. Static deformation analysis and estimation of wall stress distribution of patient-specific cerebral aneurysms can provide useful insights into the disease process and rupture. Method of Approach. The three-dimensional geometry of saccular cerebral aneurysms from 27 patients (18 unruptured and nine ruptured) was reconstructed based on computer tomography angiography images. The aneurysm wall tissue was modeled using a nonlinear, anisotropic, hyperelastic material model (Fung-type) which was incorporated in a user subroutine in ABAQUS. Effective material fiber orientations were assumed to align with principal surface curvatures. Static deformation of the aneurysm models were simulated assuming uniform wall thickness and internal pressure load of 100mmHg. Results. The numerical analysis technique was validated by quantitative comparisons to results in the literature. For the patient-specific models, in-plane stresses in the aneurysm wall along both the stiff and weak fiber directions showed significant regional variations with the former being higher. The spatial maximum of stress ranged from as low as 0.30MPa in a small aneurysm to as high as 1.06MPa in a giant aneurysm. The patterns of distribution of stress, strain, and surface curvature were found to be similar. Sensitivity analyses showed that the computed stress is mesh independent and not very sensitive to reasonable perturbations in model parameters, and the curvature-based criteria for fiber orientations tend to minimize the total elastic strain energy in the aneurysms wall. Within this small study population, there were no statistically significant differences in the spatial means and maximums of stress and strain values between the ruptured and unruptured groups. However, the ratios between the stress components in the stiff and weak fiber directions were significantly higher in the ruptured group than those in the unruptured group. Conclusions. A methodology for nonlinear, anisotropic static deformation analysis of geometrically realistic aneurysms was developed, which can be used for a more accurate estimation of the stresses and strains than previous methods and to facilitate prospective studies on the role of stress in aneurysm rupture.
Characterization and Variational Modeling of Ionic Polymer Transducers
Authors: Buechler Miles A. , Leo Donald J. 
Published: January 2007

Abstract
Ionomeric polymers are a promising class of intelligent material which exhibit electromechanical coupling similar to that of piezoelectric bimorphs. Ionomeric polymers are much more compliant than piezoelectric ceramics or polymers and have been shown to produce actuation strain on the order of 2% at operating voltages between 1V and 3V (Akle et al., 2004, Proceedings IMECE). Their high compliance is advantageous in low force sensing configurations because ionic polymers have a very little impact on the dynamics of the measured system. Here we present a variational approach to the dynamic modeling of structures which incorporate ionic polymer materials. To demonstrate the method a cantilever beam model is developed using this variational approach. The modeling approach requires a priori knowledge of three empirically determined material properties: elastic modulus, dielectric permittivity, and effective strain coefficient. Previous work by Newbury and Leo has demonstrated that these three parameters are strongly frequency dependent in the range between less than 1Hz to frequencies greater than 1kHz. Combining the frequency-dependent material parameters with the variational method produces a second-order matrix representation of the structure. The frequency dependence of the material parameters is incorporated using a complex-property approach similar to the techniques for modeling viscoelastic materials. A transducer is manufactured and the method of material characterization is applied to determine the mtaerial properties. Additional experiments are performed on this transducer and both the material and structural model are validated. Finally, the model is shown to predict sensing response very well in comparison to experimental results, which supports the use of an energy-based variational approach for modeling ionomeric polymer transducers.
An Active Dynamic Vibration Absorber for a Hand-Held Vibro-Elastography Probe
Authors: Rivaz Hassan , Rohling Robert 
Published: January 2007

Abstract
Vibro-elastography is a new medical imaging method that identifies the mechanical properties of tissue by measuring tissue motion in response to a multi-frequency external vibration source. Previous research on vibro-elastography used ultrasound to measure the tissue motion and system identification techniques to identify the tissue properties. This paper describes a hand-held probe with a combined vibration source and ultrasound transducer to implement the new method as a practical device. The device uses a proportional integral active dynamic vibration absorber with an electromagnetic actuator to counterbalance the reaction forces from contact with the tissue. Experiments show an operational frequency range of 5-20Hz, with at least 15dB vibration absorption in 0.4s for single frequency excitation. Experiments with variable frequency and amplitude excitation also show a high level of vibration absorption.
Recombinant Protein-Based Assays for Detection of Antibodies to Severe Acute Respiratory Syndrome Coronavirus Spike and Nucleocapsid Proteins
Authors: Haynes Lia M. , Miao Congrong , Harcourt Jennifer L. , Montgomery Joel M. , Le Mai Quynh , Dryga Sergey A. , Kamrud Kurt I. , Rivers Bryan , Babcock Gregory J. , Oliver Jennifer Betts , Comer James A. , Reynolds Mary , Uyeki Timothy M. , Bausch Daniel , Ksiazek Thomas , Thomas William , Alterson Harold , Smith Jonathan , Ambrosino Donna M. , Anderson Larry J. 
Published: January 2007

ABSTRACT
Recombinant severe acute respiratory syndrome (SARS) nucleocapsid and spike protein-based immunoglobulin G immunoassays were developed and evaluated. Our assays demonstrated high sensitivity and specificity to the SARS coronavirus in sera collected from patients as late as 2 years postonset of symptoms. These assays will be useful not only for routine SARS coronavirus diagnostics but also for epidemiological and antibody kinetic studies.
Evaluation of a Novel Enzyme-Linked Immunosorbent Assay To Detect Immunoglobulin G Antibody to Enolase for Serodiagnosis of Invasive Candidiasis
Authors: Laín Ana , Moragues María D. , Ruiz Juan Carlos García , Mendoza Joaquín , Camacho Ana , del Palacio Amalia , Pontón José 
Published: January 2007

ABSTRACT

The performance of a new test to detect antibodies to
Candida albicans
recombinant enolase was investigated in 47 immunocompromised and 51 immunocompetent patients. The sensitivity, specificity, and positive and negative predictive values of the test for the diagnosis of invasive candidiasis were 81.0, 83.9, 79.1, and 85.5%, respectively.
Characterization ofPlasmodium vivaxHeat Shock Protein 70 and Evaluation of Its Value for Serodiagnosis of Tertian Malaria
Authors: Na Byoung-Kuk , Park Jae-Won , Lee Hyeong-Woo , Lin Klin , Kim Seon-Hee , Bae Young-An , Sohn Woon-Mok , Kim Tong-Soo , Kong Yoon 
Published: January 2007

ABSTRACTWe have characterizedPlasmodium vivaxheat shock protein 70 (PvHSP70) and evaluated serodiagnostic applicability of recombinant PvHSP70 (rPvHSP70). In enzyme-linked immunosorbent assays and immunoblot analyses, rPvHSP70 showed high sensitivity (88.8%; 203/228 cases).P. falciparum-infected sera revealed positive reactions (78.8%). The predominant immunoglobulin G (IgG) subclasses were segregated with IgG1 and IgG3.
Novel Acetone Metabolism in a Propane-Utilizing Bacterium,Gordoniasp. Strain TY-5
Authors: Kotani Tetsuya , Yurimoto Hiroya , Kato Nobuo , Sakai Yasuyoshi 
Published: January 2007

ABSTRACTIn the propane-utilizing bacteriumGordoniasp. strain TY-5, propane was shown to be oxidized to 2-propanol and then further oxidized to acetone. In this study, the subsequent metabolism of acetone was studied. Acetone-induced proteins were found in extracts of cells induced by acetone, and a gene cluster designatedacmABwas cloned on the basis of the N-terminal amino acid sequences of acetone-induced proteins. TheacmAandacmBgenes encode a Baeyer-Villiger monooxygenase (BVMO) and esterase, respectively. The BVMO encoded byacmAwas purified from acetone-induced cells ofGordoniasp. strain TY-5 and characterized. The BVMO exhibited NADPH-dependent oxidation activity for linear ketones (C3to C10) and cyclic ketones (C4to C8).Escherichia coliexpressing theacmAgene oxidized acetone to methyl acetate, andE. coliexpressing theacmBgene hydrolyzed methyl acetate. Northern blot analyses revealed that polycistronic transcription of theacmABgene cluster was induced by propane, 2-propanol, and acetone. These results indicate that theacmABgene products play an important role in the metabolism of acetone derived from propane oxidation and clarify the propane metabolism pathway of strain TY-5 (propane → 2-propanol → acetone → methyl acetate → acetic acid + methanol). This paper provides the first evidence for BVMO-dependent acetone metabolism.
M.SpyI, a DNA Methyltransferase Encoded on a
mefA
Chimeric Element, Modifies the Genome of
Streptococcus pyogenes
Authors: Euler Chad W. , Ryan Patricia A. , Martin Judith M. , Fischetti Vincent A. 
Published: January 2007

ABSTRACT

While screening the clonality of
Streptococcus pyogenes
isolates from an outbreak of erythromycin-resistant pharyngitis in Pittsburgh, PA, we found a correlation between the presence of the chimeric element Φ10394.4 (carrying the macrolide efflux gene,
mefA
) and genomic DNA being resistant to cleavage by SmaI restriction endonuclease. A search of the open reading frames in Φ10394.4 identified a putative type II restriction-modification (R-M) cassette containing a cytosine methyltransferase gene (
spyIM
). Heterologous expression of the cloned
spyIM
gene, as well as allelic-replacement experiments, showed that the action of this methyltransferase (M.SpyI) was responsible for the inhibition of SmaI digestion of genomic DNA in the Φ10394.4-containing isolates. Analysis of the methylation patterns of streptococcal genomic DNA from
spyIM
-positive strains, a
spyIM
deletion mutant, and a
spyIM
-negative strain determined that M.SpyI specifically recognized and methylated the DNA sequence to generate 5′-C
m
CNGG. To our knowledge, this is the first methyltransferase gene from
S. pyogenes
to be cloned and to have its activity characterized. These results reveal why pulsed field gel electrophoresis analysis of SmaI-digested genomic DNA cannot be used to analyze the clonality of some streptococci containing Φ10394.4 and may explain the inability of previous epidemiological studies to use SmaI to analyze DNAs from macrolide-resistant streptococci. The presence of the SpyI R-M cassette in Φ10394.4 could impart a selective advantage to host strain survival and may provide another explanation for the observed increase in macrolide-resistant streptococci.
COBAS AmpliPrep-COBAS TaqMan Hepatitis B Virus (HBV) Test: a Novel Automated Real-Time PCR Assay for Quantification of HBV DNA in Plasma
Authors: Allice Tiziano , Cerutti Francesco , Pittaluga Fabrizia , Varetto Silvia , Gabella Silvia , Marzano Alfredo , Franchello Alessandro , Colucci Giuseppe , Ghisetti Valeria 
Published: January 2007

ABSTRACT

Success in antiviral therapy for chronic hepatitis B is supported by highly sensitive PCR-based assays for hepatitis B virus (HBV) DNA. Nucleic acid extraction from biologic specimens is technically demanding, and reliable PCR results depend on it. The performances of the fully automatic system COBAS AmpliPrep-COBAS TaqMan 48 (CAP-CTM; Roche, Branchburg, NJ) for HBV DNA extraction and real-time PCR quantification were assessed and compared to the endpoint PCR COBAS AMPLICOR HBV monitor (CAHBM; Roche). Analytical evaluation with a proficiency panel showed that CAP-CTM quantitated HBV DNA levels in one single run over a wide dynamic range (7 logs) with a close correlation between expected and observed values (
r
= 0.976, interassay variability below 5%). Clinical evaluation, as tested with samples from 92 HBsAg-positive patients, demonstrated excellent correlation with CAHBM (
r
= 0.966, mean difference in quantitation = 0.36 log
10
IU/ml). CAP-CTM detected 10% more viremic patients and longer periods of residual viremia in those on therapy. In lamivudine (LAM)-resistant patients, the reduction of HBV DNA after 12 months of Adefovir (ADF) was higher in the combination (LAM+ADF) schedule than in ADF monotherapy (5.1 logs versus 3.5 logs), suggesting a benefit in continuing LAM. CAP-CTM detected HBV DNA in liver biopsy samples from 15% of HBsAg-negative, anti-HBcAg-positive graft donors with no HBV DNA in plasma. The amount of intrahepatic HBV DNA was significantly lower in occult HBV infection than in overt disease. CAP-CTM can improve the management of HBV infection and the assessment of antiviral therapy and drug resistance, supporting further insights in the emerging area of occult HBV infection.
Intimin Types Determined by Heteroduplex Mobility Assay of Intimin Gene (
eae
)-Positive
Escherichia coli
Strains
Authors: Ito Kenitiro , Iida Mariko , Yamazaki Mitsugu , Moriya Kazuo , Moroishi Sanae , Yatsuyanagi Jun , Kurazono Takayuki , Hiruta Noriaki , Ratchtrachenchai Orn-Anong 
Published: January 2007

ABSTRACT

We developed a quick genetic approach to screen variants of the intimin gene (
eae
) by using a heteroduplex mobility assay (HMA) that targets the 5′ conserved region of
eae
. The
eae
variants were categorized into 4 major HMA types and 10 minor subtypes.
Real-Time PCR Diagnostics Failure Caused by Nucleotide Variability within Exon 4 of the Human Cytomegalovirus Major Immediate-Early Gene
Authors: Lengerova Martina , Racil Zdenek , Volfova Pavlina , Lochmanova Jana , Berkovcova Jitka , Dvorakova Dana , Vorlicek Jiri , Mayer Jiri 
Published: January 2007

ABSTRACT
Here we report how variability in the human cytomegalovirus genome sequence may seriously affect the outcome of its molecular diagnosis. A real-time quantitative PCR assay targeting the major immediate-early gene failed to detect the viral load in some, but not all, clinical samples from hematooncological patients. By amplification and sequencing the DNA across the regions targeted by this assay we found a number of nucleotide substitutions which accounted for decreased primer/probe binding. This decreased the sensitivity of the assay up to 1,000-fold.
Quantitative Detection and Rapid Identification of Human Adenoviruses
Authors: Miura-Ochiai Rika , Shimada Yasushi , Konno Tsunetada , Yamazaki Shudo , Aoki Koki , Ohno Shigeaki , Suzuki Eitaro , Ishiko Hiroaki 
Published: January 2007

ABSTRACT

We have established a method of quantitative detection and rapid identification of human adenoviruses (hAdVs). Using LightCycler PCR with a primer set, we were able to amplify 554 bp of the hexon gene from each of 51 prototype strains of hAdVs. The sensitivity of LightCycler PCR was 10 copies of hAdV DNA/reaction. When LightCycler PCR was performed using a set of primers, hAdV was positive for 74.4% (99 of 133) of conjunctivitis patients and for 27.3% (81 of 297) of respiratory infection patients. We also attempted to measure hAdV in the potentially contaminated eye drops used by patients, detecting 5.4 × 10
2
to 1.6 × 10
6
copies/ml of hAdV. We determined the 350-bp nucleotide sequence of the amplified hexon gene and compared it with the sequences of the 51 prototype strains. Phylogenetic analysis based on 350 bp of the hexon gene identified 99 positive conjunctival swabs as 24 cases of AdV type 3 (AdV-3), 14 cases of AdV-4, 1 case of AdV-8, 19 cases of AdV-19a, and 41 cases of AdV-37. The 81 sequences from pharyngeal or nasal mucus swabs were identified as 29 cases of AdV-2, 18 cases of AdV-1, 18 cases of AdV-5, 12 cases of AdV-4, 2 cases of AdV-37, 1 case of AdV-3, and 1 case of AdV-6. LightCycler PCR followed by phylogenetic analysis provides an effective tool for the rapid identification of hAdVs and for studying molecular epidemiology.
Mutated G4P[8] Rotavirus Associated with a Nationwide Outbreak of Gastroenteritis in Nicaragua in 2005
Authors: Bucardo Filemon , Karlsson Beatrice , Nordgren Johan , Paniagua Margarita , González Alcides , Amador Juan Jose , Espinoza Felix , Svensson Lennart 
Published: January 2007

ABSTRACT
During February and March 2005, one of the largest national recorded outbreaks of severe acute gastroenteritis occurred in Nicaragua, affecting ≥64,000 individuals and causing ≥56 deaths, predominantly in children under 5 years of age. Through a nationwide laboratory-based study, stool samples were collected and investigated for rotavirus. Of 108 stool samples examined, 72 (67%) were positive for rotavirus. While 69% (50/72) of the positive samples were found in children less than 2 years of age, 50% (6/12) of the adult samples were positive. A mutated G4P[8] strain was the most commonly recognized strain (85%), followed by mixed G strains (8%) and G9P[8] (7%) strains. Phylogenetic analysis of the VP7 gene revealed that the G4 strains belonged to the emerging lineage Ic and was distantly related to the ST3 and VA70 G4 strains. Secondary structure predictions of the VP7 G4 protein revealed an insert of an asparagine residue in position 76, which, combined with additional mutations, surprisingly modified two downstream β-sheets at amino acid positions 80 to 85 and 115 to 119. The 2005 G4P[8] strain compared to a G4P[8] strain from 2002 had a substitution of an asparagine residue for threonine (Asn→Thr) at position 96 within antigenic region A, thus eliminating a potential glycosylation site. The mutated G4 virus was introduced in Nicaragua after 2002 and probably emerged from Brazil, Argentina, or Uruguay.