bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using Tiptiming and Strain Gauge Data for the Estimation of Consumed Life in a Compressor Blisk Subjected to Stall-Induced Loading
Authors: Kharyton Vsevolod , Bladh Ronnie 
Published: September 2014

Using tip timing technology to record blade vibratory behavior has grown to become an industry standard over the past decade. Typically, the technology gets used during engine prototype testing to verify safe operation of the blades and thus the engine through synchronous and non-synchronous excitation events. Another common application is blade health monitoring, where the technique is used to detect deviations in natural frequencies and/or amplitudes compared to the virgin state. In both cases, acquired response data are used to establish that blade stresses remain below the high cycle fatigue limit. More rarely is tip timing data used as basis for remaining life estimation.
As an example of how tip timing technology can be used beyond traditional resonance clearance for new blade designs, this paper presents an assessment of the fatigue damage incurred to a transonic compressor rotor subjected to stall-induced dynamic loading. The compressor rotor in question is equipped with tip timing, as well as strain gauges for a limited set of airfoils. The dynamic loads at stall are non-synchronous and highly erratic in nature, leading to quasi-static response of multiple modes. To facilitate a conceptually straightforward time domain finite life fatigue analysis, different strategies are employed to reconstruct the stress-time signal from tip timing data. This in turn allows for quantification of accumulated damage cycles, which is here done through simplified and traditional rainflow counting techniques.
Additionally, a non-standard way of processing of tip timing data was employed to overcome one of tip timing method drawbacks — frequency aliasing. As an approach the nonuniform Fourier transform was applied to the same data sets. The results obtained are thoroughly evaluated and compared with strain gauges results highlighting the benefits and limitations of the respective approaches for highly complex stress-time histories such as stall events.
Volute CFD Modeling Evaluation for Centrifugal Compressors
Authors: Samale Anil , Pacheco Jorge E. 
Published: September 2014

Significant effort has been spent over the years to improve the accuracy and reduce the Computational Fluid Dynamics (CFD) simulation time required to predict performance for centrifugal compressors. Most of the emphasis has been on modeling the impeller and diffuser components. This paper presents an evaluation of volute modeling targeted at reducing simulation time while increasing the accuracy of the results. Providing accurate predictions of performance and operating range is critical to the equipment users as it allows reduction in design margins for plant equipment dependent on compressor performance (i.e. drivers, intercoolers and other auxiliary equipment).
The volute is the component that collects the flow from the diffuser and guides it into the discharge nozzle. Due to the circumferential variation (tongue) in the geometry, this component has to be modeled in its entirety (360 degrees); which results in very large grid sizes. The impeller and diffuser, normally modeled as a sector or pie slice, result in significantly smaller meshes. The volute models require large numbers of computing nodes to be solved and tend to have convergence issues.
The investigation, with the objective of reducing the amount of time required to run these simulations and improve the convergence of the runs, evaluated several mesh configurations that focused on grid density (element count), element aspect ratio and use of inflation layers. The domain evaluated consisted of several stationary components and one rotating component. The model started at the inlet guide vane section followed by the impeller, vanned diffuser, volute, and discharge nozzle. Commercial software ANSYS CFX was used to develop the meshes using tetrahedral/prism elements and complete steady-state CFD analyses.
Detailed flow field characteristics (total and static pressure, velocity streamlines, etc.) and key performance parameters (loss coefficient, pressure ratio, etc.) were compared for the various configurations evaluated. In addition, experimental measurements were used to validate the CFD results. The configuration that resulted in the shortest cycle time with the best performance accuracy was selected as optimum. Accuracy is paramount for performance prediction and reduction in simulation time will allow more volute iterations to be investigated, which would help improve volute performance in centrifugal compressors.
Cascaded systems analysis of photon counting detectors
Authors: Xu J. , Zbijewski W. , Gang G. , Stayman J. W. , Taguchi K. , Lundqvist M. , Fredenberg E. , Carrino J. A. , Siewerdsen J. H. 
Published: September 2014

Purpose:Photon counting detectors (PCDs) are an emerging technology with applications in spectral and low‐dose radiographic and tomographic imaging. This paper develops an analytical model of PCD imaging performance, including the system gain, modulation transfer function (MTF), noise‐power spectrum (NPS), and detective quantum efficiency (DQE).Methods:A cascaded systems analysis model describing the propagation of quanta through the imaging chain was developed. The model was validated in comparison to the physical performance of a silicon‐strip PCD implemented on an experimental imaging bench. The signal response, MTF, and NPS were measured and compared to theory as a function of exposure conditions (70 kVp, 1–7 mA), detector threshold, and readout mode (i.e., the option for coincidence detection). The model sheds new light on the dependence of spatial resolution, charge sharing, and additive noise effects on threshold selection and was used to investigate the factors governing PCD performance, including the fundamental advantages and limitations of PCDs in comparison to energy‐integrating detectors (EIDs) in the linear regime for which pulse pileup can be ignored.Results:The detector exhibited highly linear mean signal response across the system operating range and agreed well with theoretical prediction, as did the system MTF and NPS. The DQE analyzed as a function of kilovolt (peak), exposure, detector threshold, and readout mode revealed important considerations for system optimization. The model also demonstrated the important implications of false counts from both additive electronic noise and charge sharing and highlighted the system design and operational parameters that most affect detector performance in the presence of such factors: for example, increasing the detector threshold from 0 to 100 (arbitrary units of pulse height threshold roughly equivalent to 0.5 and 6 keV energy threshold, respectively), increased the f50 (spatial‐frequency at which the MTF falls to a value of 0.50) by ∼30% with corresponding improvement in DQE. The range in exposure and additive noise for which PCDs yield intrinsically higher DQE was quantified, showing performance advantages under conditions of very low‐dose, high additive noise, and high fidelity rejection of coincident photons.Conclusions:The model for PCD signal and noise performance agreed with measurements of detector signal, MTF, and NPS and provided a useful basis for understanding complex dependencies in PCD imaging performance and the potential advantages (and disadvantages) in comparison to EIDs as well as an important guide to task‐based optimization in developing new PCD imaging systems.
16S rRNA Gene Sequencing, Multilocus Sequence Analysis, and Mass Spectrometry Identification of the Proposed New Species “Clostridium neonatale”
Authors: Bouvet Philippe , Ferraris Laurent , Dauphin Brunhilde , Popoff Michel-Robert , Butel Marie Jose , Aires Julio 
Published: September 2014

ABSTRACT

In 2002, an outbreak of necrotizing enterocolitis in a Canadian neonatal intensive care unit was associated with a proposed novel species of
Clostridium
, “
Clostridium neonatale
.” To date, there are no data about the isolation, identification, or clinical significance of this species. Additionally,
C. neonatale
has not been formally classified as a new species, rendering its identification challenging. Indeed, the
C. neonatale
16S rRNA gene sequence shows high similarity to another
Clostridium
species involved in neonatal necrotizing enterocolitis,
Clostridium butyricum
. By performing a polyphasic study combining phylogenetic analysis (16S rRNA gene sequencing and multilocus sequence analysis) and phenotypic characterization with mass spectrometry, we demonstrated that
C. neonatale
is a new species within the
Clostridium
genus
sensu stricto
, for which we propose the name
Clostridium neonatale
sp. nov. Now that the status of
C. neonatale
has been clarified, matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) can be used for better differential identification of
C. neonatale
and
C. butyricum
clinical isolates. This is necessary to precisely define the role and clinical significance of
C. neonatale
, a species that may have been misidentified and underrepresented during previous neonatal necrotizing enterocolitis studies.
First Report of Westerdykella dispersa as a Cause of an Angioinvasive Fungal Infection in a Neutropenic Host
Authors: Sue Paul K. , Gurda Grzegorz T. , Lee Richard , Watkins Tonya , Green Rachel , Memon Warda , Milstone Aaron M. , Zelazny Adrian M. , Fahle Gary A. , Pham Thu Anh , Gibas Connie F. , Sutton Deanna A. , Wickes Brian L. , Wiederhold Nathan P. , Zhang Sean X. 
Published: September 2014

ABSTRACT

Angioinvasive fungal infections (AFIs) are an important cause of morbidity and mortality among immunocompromised patients. However, clinicomicrobiological characteristics and treatment of many AFI agents remain poorly defined. We report the first human case of infection with
Westerdykella dispersa
, an emergent cause of AFI, which was successfully treated in a neutropenic pediatric patient.
A Single-Tube Multiple-Locus Variable-Number Tandem-Repeat Analysis of Mycoplasma pneumoniae Clinical Specimens by Use of Multiplex PCR-Capillary Electrophoresis
Authors: Yan Chao , Sun Hongmei , Xue Guanhua , Zhao Hanqing , Wang Liqiong , Feng Yanling , Li Shaoli 
Published: September 2014

ABSTRACT

In this study, we developed a single-tube multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) assay to type
Mycoplasma pneumoniae
directly from respiratory samples collected from children with respiratory infections. The multiplex PCR included four fluorescently primed VNTRs (Mpn13, Mpn14, Mpn15, and Mpn16) and was carried out in a single tube. A total of 137
M. pneumoniae
-positive specimens, collected in 2013 from Beijing, China, were divided among four types (M4-5-7-2, M4-5-6-2, M3-5-6-2, and M5-5-7-2) using the amended MLVA system. The most prevalent genotype was M4-5-7-2. No correlation was found between macrolide resistance in the
M. pneumoniae
samples and the MLVA types. To our knowledge, this is the first study to type and analyze
M. pneumoniae
clinical specimens using multiplex PCR-capillary electrophoresis in a single tube. This novel low-cost method can be used to rapidly type
M. pneumoniae
clinical specimens directly and shows great potential for monitoring outbreaks of
M. pneumoniae
.
Evaluation of the BD Max MRSA
XT
Assay for Use with Different Swab Types
Authors: Dalpke Alexander H. , Hofko Marjeta , Stock Christian , Zimmermann Stefan 
Published: September 2014

ABSTRACT

We evaluated the performance of the BD Max MRSA
XT
assay for use with different swab types. The 90% detection rates (95% confidence intervals) were 387 (97 to 1,551), 877 (238 to 3,230), 986 (183 to 5,287), 1,292 (328 to 5,078), 2,400 (426 to 13,518), and 5,848 (622 to 55,021) CFU/swab for Liquid Stuart, Liquid Amies, dry, Amies Gel without charcoal, ESwab collection, and Amies gel with charcoal swabs (Becton Dickinson), respectively. Amies Gel without charcoal, ESwab collection, and Amies gel with charcoal swabs had a tendency to be less sensitive, but none of the differences was statistically significant.
Molecular Requirement for Sterols in Herpes Simplex Virus Entry and Infectivity
Authors: Wudiri George A. , Pritchard Suzanne M. , Li Hong , Liu Jin , Aguilar Hector C. , Gilk Stacey D. , Nicola Anthony V. 
Published: September 2014

ABSTRACT

Herpes simplex virus 1 (HSV-1) required cholesterol or desmosterol for virion-induced membrane fusion. HSV successfully entered DHCR24
−/−
cells, which lack a desmosterol-to-cholesterol conversion enzyme, indicating that entry can occur independently of cholesterol. Depletion of desmosterol from these cells resulted in diminished HSV-1 entry, suggesting a general sterol requirement for HSV-1 entry and that desmosterol can operate in virus entry. Cholesterol functioned more effectively than desmosterol, suggesting that the hydrocarbon tail of cholesterol influences viral entry.
Development of Dose-Response Models of Creutzfeldt-Jakob Disease Infection in Nonhuman Primates for Assessing the Risk of Transfusion-Transmitted Variant Creutzfeldt-Jakob Disease
Authors: Huang Yin , Gregori Luisa , Anderson Steven A. , Asher David M. , Yang Hong 
Published: September 2014

ABSTRACT
Estimates for the risk of transmitting variant Creutzfeldt-Jakob disease (vCJD) via blood transfusion have relied largely on data from rodent experiments, but the relationship between dose (amount of infected blood) and response (vCJD infection) has never been well quantified. The goal of this study was to develop a dose-response model based on nonhuman primate data to better estimate the likelihood of transfusion-transmitted vCJD (TTvCJD) in humans. Our model used dose-response data from nonhuman primates inoculated intracerebrally (i.c.) with brain tissues of patients with sporadic and familial CJD. We analyzed the data statistically by using a beta-Poisson dose-response model. We further adjusted model parameters to account for the differences in infectivity between blood and brain tissue and in transmission efficiency between intravenous (i.v.) and i.c. routes to estimate dose-dependent TTvCJD infection. The model estimates a mean infection rate of 76% among recipients who receive one unit of whole blood collected from an infected donor near the end of the incubation period. The nonhuman primate model provides estimates that are more consistent with those derived from a risk analysis of transfused nonleukoreduced red blood cells in the United Kingdom than prior estimates based on rodent models.

IMPORTANCE
TTvCJD was recently identified as one of three emerging infectious diseases posing the greatest immediate threat to the safety of the blood supply. Cases of TTvCJD were reported in recipients of nonleukoreduced red blood cells and coagulation factor VIII manufactured from blood of United Kingdom donors. As the quantity of abnormal prions (the causative agent of TTvCJD) varies significantly in different blood components and products, it is necessary to quantify the dose-response relationship for a wide range of doses for the vCJD agent in transfused blood and plasma derivatives. In this paper, we suggest the first mechanistic dose-response model for TTvCJD infection based on data from experiments with nonhuman primates. This new model may improve estimates of the possible risk to humans.
Characterization of an Alphamesonivirus 3C-Like Protease Defines a Special Group of Nidovirus Main Proteases
Authors: Blanck Sandra , Stinn Anne , Tsiklauri Lali , Zirkel Florian , Junglen Sandra , Ziebuhr John 
Published: September 2014

ABSTRACT

Cavally virus (CavV) and related viruses in the family
Mesoniviridae
diverged profoundly from other nidovirus lineages but largely retained the characteristic set of replicative enzymes conserved in the
Coronaviridae
and
Roniviridae
. The expression of these enzymes in virus-infected cells requires the extensive proteolytic processing of two large replicase polyproteins, pp1a and pp1ab, by the viral 3C-like protease (3CL
pro
). Here, we show that CavV 3CL
pro
autoproteolytic cleavage occurs at two N-terminal (N1 and N2) and one C-terminal (C1) processing site(s). The mature form of 3CL
pro
was revealed to be a 314-residue protein produced by cleavage at FKNK
1386
|SAAS (N2) and YYNQ
1700
|SATI (C1). Site-directed mutagenesis data suggest that the mesonivirus 3CL
pro
employs a catalytic Cys-His dyad comprised of CavV pp1a/pp1ab residues Cys-1539 and His-1434. The study further suggests that mesonivirus 3CL
pro
substrate specificities differ from those of related nidovirus proteases. The presence of Gln (or Glu) at the P1 position was not required for cleavage, although residues that control Gln/Glu specificity in related viral proteases are retained in the CavV 3CL
pro
sequence. Asn at the P2 position was identified as a key determinant for mesonivirus 3CL
pro
substrate specificity. Other positions, including P4 and P1′, each are occupied by structurally related amino acids, indicating a supportive role in substrate binding. Together, the data identify a new subgroup of nidovirus main proteases and support previous conclusions on phylogenetic relationships between the main nidovirus lineages.

IMPORTANCE
Mesoniviruses have been suggested to provide an evolutionary link between nidovirus lineages with small (13 to 16 kb) and large (26 to 32 kb) RNA genome sizes, and it has been proposed that a specific set of enzymes, including a proofreading exoribonuclease and other replicase gene-encoded proteins, play a key role in the major genome expansion leading to the currently known lineages of large nidoviruses. Despite their smaller genome size (20 kb), mesoniviruses retained most of the replicative domains conserved in large nidoviruses; thus, they are considered interesting models for studying possible key events in the evolution of RNA genomes of exceptional size and complexity. Our study provides the first characterization of a mesonivirus replicase gene-encoded nonstructural protein. The data confirm and extend previous phylogenetic studies of mesoniviruses and related viruses and pave the way for studies into the formation of the mesonivirus replication complex and functional and structural studies of its functional subunits.
Establishment and Characterization of an Air-Liquid Canine Corneal Organ Culture Model To Study Acute Herpes Keratitis
Authors: Harman Rebecca M. , Bussche Leen , Ledbetter Eric C. , Van de Walle Gerlinde R. 
Published: September 2014

ABSTRACTDespite the clinical importance of herpes simplex virus (HSV)-induced ocular disease, the underlying pathophysiology of the disease remains poorly understood, in part due to the lack of adequate virus–natural-host models in which to study the cellular and viral factors involved in acute corneal infection. We developed an air-liquid canine corneal organ culture model and evaluated its susceptibility to canine herpesvirus type 1 (CHV-1) in order to study ocular herpes in a physiologically relevant natural host model. Canine corneas were maintained in culture at an air-liquid interface for up to 25 days, and no degenerative changes were observed in the corneal epithelium during cultivation using histology for morphometric analyses, terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling (TUNEL) assays, and transmission electron microscopy (TEM). Next, canine corneas were inoculated with CHV-1 for 48 h, and at that time point postinfection, viral plaques could be visualized in the corneal epithelium and viral DNA copies were detected in both the infected corneas and culture supernatants. In addition, we found that canine corneas produced proinflammatory cytokines in response to CHV-1 infection similarly to what has been described for HSV-1. This emphasizes the value of our model as a virus–natural-host model to study ocular herpesvirus infections.IMPORTANCEThis study is the first to describe the establishment of an air-liquid canine corneal organ culture model as a useful model to study ocular herpesvirus infections. The advantages of this physiologically relevant model include the fact that (i) it provides a system in which ocular herpes can be studied in a virus–natural-host setting and (ii) it reduces the number of experimental animals needed. In addition, this long-term explant culture model may also facilitate research in other fields where noninfectious and infectious ocular diseases of dogs and humans are being studied.
Molecular Mimicry between Dengue Virus and Coagulation Factors Induces Antibodies To Inhibit Thrombin Activity and Enhance Fibrinolysis
Authors: Chuang Yung-Chun , Lin Yee-Shin , Liu Hsiao-Sheng , Yeh Trai-Ming 
Published: September 2014

ABSTRACT

Dengue virus (DENV) is the most common cause of viral hemorrhagic fever, and it may lead to life-threating dengue hemorrhagic fever and shock syndrome (DHF/DSS). Because most cases of DHF/DSS occur in patients with secondary DENV infection, anti-DENV antibodies are generally considered to play a role in the pathogenesis of DHF/DSS. Previously, we have found that antithrombin antibodies (ATAs) with both antithrombotic and profibrinolytic activities are present in the sera of dengue patients. However, the mechanism by which these autoantibodies are induced is unclear. In this study, we demonstrated that antibodies induced by DENV immunization in mice and rabbits could bind to DENV antigens as well as to human thrombin and plasminogen (Plg). The binding of anti-DENV antibodies to thrombin and Plg was inhibited by preadsorption with DENV nonstructural protein 1. In addition, affinity-purified ATAs from DENV-immunized rabbit sera could inhibit thrombin activity and enhance Plg activation both
in vitro
and
in vivo
. Taken together, our results suggest that molecular mimicry between DENV and coagulation factors can induce the production of autoantibodies with biological effects similar to those of ATAs found in dengue patients. These coagulation-factor cross-reactive anti-DENV antibodies can interfere with the balance of coagulation and fibrinolysis, which may lead to the tendency of DHF/DSS patients to bleed.

IMPORTANCE
Dengue virus (DENV) infection is the most common mosquito-borne viral disease in tropical and subtropical areas. Over 50 million DENV infection cases develop each year, and more than 2.5 billion people are at risk of dengue-induced hemorrhagic fever and shock syndrome. Currently, there is no vaccine or drug treatment for DENV. In the present study, we demonstrated that DENV immunization could induce thrombin and plasminogen (Plg) cross-reactive antibodies, which were able to inhibit thrombin activity and enhance Plg activation. These results suggest that molecular mimicry between DENV antigens, thrombin, and Plg may elicit antibodies that disturb hemostasis. The selection of appropriate candidate antigens for use in DENV vaccines should prevent these potentially dangerous autoimmune responses.