bluuebunny/crossref_metadata_2025_split huggingface dataset:
P2X7 receptor–Pannexin1 interaction mediates stress‐induced interleukin‐1 beta expression in human periodontal ligament cells
Authors: Kanjanamekanant K. , Luckprom P. , Pavasant P. 
Published: November 2013

Background and ObjectivePannexin 1 (Panx1) has been found to form nonjunctional hemichannels. It is also proposed to combine with the P2X7 receptor, forming a complex involved in adenosine triphosphate (ATP)‐induced interleukin‐1beta (IL‐1β) release in macrophages. Previously, we reported that mechanical stress induced IL‐1β expression via the ATP/P2X7 receptor‐dependent pathway in human periodontal ligament (HPDL) cells and that ATP was released through the connexin 43 (Cx43) hemichannel. In the present work, we examined the role of Panx1 in stress‐induced IL‐1β induction in HPDL cells.Material and MethodsCultured HPDL cells were treated with compressive loading or ATP to stimulate IL‐1β expression. Inhibitors, antagonists and the small interfering RNA technique were used to investigate the involvement of Panx1 in IL‐1β induction. Co‐immunoprecipitation (Co‐IP) and immunostaining were used to determine the association of Panx1 with the P2X7 receptor. The IL‐1β release mechanism was analyzed using inhibitors.ResultsBlocking Panx1 significantly decreased ATP release, as well as IL‐1β up‐regulation, upon stimulation with stress or ATP. Co‐IP revealed the association of Panx1 and the P2X7 receptor in HPDL cells, which was increased in response to mechanical loading. Pretreatment with vesicular trafficking inhibitors significantly reduced the amount of IL‐1β released from stimulated cells, suggesting that IL‐1β might be released through vesicles.ConclusionWe clearly illustrated the contribution of Panx1 in ATP release, as well as in IL‐1β induction in HPDL cells. The association of Panx1 and the P2X7 receptor might be required for IL‐1β induction, and their possible novel role in IL‐1β vesicular release was indicated.
Hepatitis C virus core antigen testing in liver and kidney transplant recipients
Authors: Heidrich B. , Pischke S. , Helfritz F. A. , Mederacke I. , Kirschner J. , Schneider J. , Raupach R. , Jäckel E. , Barg‐Hock H. , Lehner F. , Klempnauer J. , von Hahn T. , Cornberg M. , Manns M. P. , Ciesek S. , Wedemeyer H. 
Published: November 2013

SummaryHCV RNA levels correlate with the long‐term outcome of hepatitis C in liver transplant recipients. Nucleic acid testing (NAT) is usually used to confirm HCV reinfection and to examine viral loads after liver transplantation. HCV core antigen (HCVcoreAg) testing could be an alternative to NAT with some potential advantages including very low intra‐ and interassay variabilities and lower costs. The performance of HCVcoreAg testing in organ transplant recipients is unknown. We prospectively studied 1011 sera for HCV RNA and HCVcoreAg in a routine real‐world setting including 222 samples obtained from patients after liver or kidney transplantation. HCV RNA and HCVcoreAg test results showed a consistency of 98% with a very good correlation in transplanted patients (r > 0.85). The correlation between HCV RNA and HCVcoreAg was higher in sera with high viral loads and in samples from patients with low biochemical disease. Patients treated with tacrolimus showed a better correlation between both parameters than individuals receiving cyclosporine A. HCV RNA/HCVcoreAg ratios did not differ between transplanted and nontransplanted patients, and HCV RNA and HCVcoreAg kinetics were almost identical during the first days after liver transplantation. HCVcoreAg testing can be used to monitor HCV viral loads in patients after organ transplantation. However, the assay is not recommended to monitor antiviral therapies.
Sphericity Index and E‐Point‐to‐Septal‐Separation (EPSS) to Diagnose Dilated Cardiomyopathy in Doberman Pinschers
Authors: Holler P.J. , Wess G. 
Published: November 2013

BackgroundE‐point‐to‐septal‐separation (EPSS) and the sphericity index (SI) are echocardiographic parameters that are recommended in theESVC‐DCMguidelines. However,SIcutoff values to diagnose dilated cardiomyopathy (DCM) have never been evaluated.ObjectivesTo establish reference ranges, calculate cutoff values, and assess the clinical value ofSIandEPSSto diagnoseDCMin Doberman Pinschers.AnimalsOne hundred seventy‐nine client‐owned Doberman Pinschers.MethodsThree groups were formed in this prospective longitudinal study according to established Holter and echocardiographic criteria using the Simpson method of disk (SMOD): control group (97 dogs),DCMwith echocardiographic changes (75 dogs) and “last normal” group (n = 7), which included dogs that developedDCMwithin 1.5 years, but were still normal at this time point. In a substudy, dogs with earlyDCMbased uponSMODvalues above the reference range but still normal M‐Mode measurements were selected, to evaluate ifEPSSorSIwere abnormal using the established cutoff values.ResultsROC‐curve analysis determined <1.65 for theSI(sensitivity 86.8%; specificity 87.6%) and >6.5 mm forEPSS(sensitivity 100%; specificity 99.0%) as optimal cutoff values to diagnoseDCM. Both parameters were significantly different between the control group and theDCMgroup (P < 0.001), but were not abnormal in the “last normal” group. In the substudy,EPSSwas abnormal in 13/13 dogs andSIin 2/13 dogs.Conclusions and Clinical ImportanceE‐point‐to‐septal‐separation is a valuable additional parameter for the diagnosis ofDCM, which can enhance diagnostic capabilities of M‐Mode and which performs similar as well asSMOD.
Evaluation of enrofloxacin use in koalas (Phascolarctos cinereus) via population pharmacokinetics andMonteCarlo simulation
Authors: Black L. A. , Landersdorfer C. B. , Bulitta J. B. , Griffith J. E. , Govendir M. 
Published: November 2013

Clinically normal koalas (n = 6) received a single dose of intravenous enrofloxacin (10 mg/kg). Serial plasma samples were collected over 24 h, and enrofloxacin concentrations were determined via high‐performance liquid chromatography. Population pharmacokinetic modeling was performed inS‐ADAPT. The probability of target attainment (PTA) was predicted via Monte Carlo simulations (MCS) using relevant target values (30–300) based on the unbound area under the curve over 24 h divided by the minimum inhibitory concentration (MIC) (fAUC0–24/MIC), and published subcutaneous data were incorporated (Griffithet al., 2010). A two‐compartment disposition model with allometrically scaled clearances (exponent: 0.75) and volumes of distribution (exponent: 1.0) adequately described the disposition of enrofloxacin. For 5.4 kg koalas (average weight), point estimates for total clearance (SE%) were 2.58 L/h (15%), central volume of distribution 0.249 L (14%), and peripheral volume 2.77 L (20%).MCSusing a targetfAUC0–24/MICof 40 predicted highest treatableMICs of 0.0625 mg/L for intravenous dosing and 0.0313 mg/L for subcutaneous dosing of 10 mg/kg enrofloxacin every 24 h. Thus, the frequently used dosage of 10 mg/kg enrofloxacin every 24 h subcutaneously may be appropriate against gram‐positive bacteria withMICs ≤ 0.03 mg/L (PTA > 90%), but appears inadequate against gram‐negative bacteria andChlamydiae in koalas.
The Y123H substitution perturbs FvCYP51B function and confers prochloraz resistance in laboratory mutants of Fusarium verticillioides
Authors: Fan J. , Chen F. , Diao Y. , Cools H. J. , Kelly S. L. , Liu X. 
Published: November 2013

Fusarium verticillioides reduces corn yield and contaminates infected kernels with the toxin fumonisin, which is harmful to humans and animals. Previous research has demonstrated that F. verticillioides can be controlled by the azole fungicide prochloraz. Currently, prochloraz is used as a foliar spray to control maize disease in China, which will increase the risk of resistance. Although F. verticillioides resistance to prochloraz has not been reported in the field, possible resistance risk and mechanisms resulting in prochloraz resistance were explored in the laboratory. Four prochloraz‐resistant strains of F. verticillioides were generated by successive selection on fungicide‐amended media. The mycelial growth rates of the mutants were inversely related to the level of resistance. All four mutants were cross‐resistant to the triazole fungicides triadimefon, tebuconazole and difenoconazole, but not to the multisite fungicide chlorothalonil or to the MAP/histidine‐kinase inhibitor fungicide fludioxonil. Based on the Y123H mutation in FvCYP51B, the four resistant mutants were subdivided into two genotypes: PCZ‐R1 mutants with wildtype FvCYP51B and PCZ‐R2 mutants with substitution Y123H in FvCYP51B. Wildtype FvCYP51B complemented the function of native ScCYP51 in Saccharomyces cerevisiae YUG37::erg11, whereas Y123H‐mutated FvCYP51B did not. For the PCZ‐R1 mutants, induced expression of FvCYP51A increased resistance to prochloraz. For the PCZ‐R2 mutants, disruption of FvCYP51B function by the Y123H substitution caused constitutive up‐regulation of FvCYP51A expression and thus resistance to prochloraz.
Mistuning Modeling and its Validation for Small Turbine Wheels
Authors: Hemberger David , Filsinger Dietmar , Bauer Hans-Jörg 
Published: November 2013

The production of bladed structures, e.g. turbine and compressor wheels, is a subject of statistical scatter. The blades are designed to be identical but differ due to small manufacturing tolerances. This so called mistuning can lead to increased vibration amplitudes compared to the ideal tuned case.
The object of this study is to create and validate numerical models to evaluate such mistuning effects of turbine wheels for automotive turbocharger applications. As a basis for the numerical analysis vibration measurements under stand-still conditions were carried out by using a laser surface velocimeter (LSV). The scope of this investigation was to identify the mistuning properties of the turbine wheels namely the frequency deviation from the ideal, cyclic symmetrical tuned system. Experimental modal analyses as well as blade by blade measurements were performed. Moreover 3D scanning techniques were employed to determine geometric deviations.
Numerical FE models and a simplified multi degree of freedom model (EBM) were created to reproduce the measured mistuning effects. The prediction of mode localization and the calculated amplitude amplification were evaluated. The best results were obtained with a FE model that employs individual sectorial stiffnesses. The results also indicate that the major contribution to mistuning is made by material inhomogeneities and not by geometric deviations from ideal dimensions.
With the adjusted FE model a probabilistic study has been performed to investigate the influence of the mistuning on the amplitude amplification factor. It has been found that at a certain level of mistuning the amplification factor remains constant or slightly decreases. By introducing intentional mistuning a lower sensitivity as well as a decrease of the amplitude amplification could be achieved.
Small Horizontal Axis Wind Turbine: Analytical Blade Design and Comparison With RANS-Prediction and First Experimental Data
Authors: Gerhard Tom , Sturm Michael , Carolus Thomas H. 
Published: November 2013

State-of-the-art wind turbine performance prediction is mainly based on semi-analytical models, incorporating blade element momentum (BEM) analysis and empirical models. Full numerical simulation methods can yield the performance of a wind turbine without empirical assumptions. Inherent difficulties are the large computational domain required to capture all effects of the unbounded ambient flow field and the fact that the boundary layer on the blade may be transitional.
A modified turbine design method in terms of the velocity triangles, Euler’s turbine equation and BEM is developed. Lift and drag coefficients are obtained from XFOIL, an open source 2D design and analysis tool for subcritical airfoils. A 3 m diameter horizontal axis wind turbine rotor was designed and manufactured. The flow field is predicted by means of a Reynolds-averaged Navier-Stokes simulation. Two turbulence models were utilized: (i) a standard k-ω-SST model, (ii) a laminar/turbulent transition model. The manufactured turbine is placed on the rooftop of the University of Siegen. Three wind anemometers and wind direction sensors are arranged around the turbine. The torque is derived from electric power and the rotational speed via a calibrated grid-connected generator.
The agreement between the analytically and CFD-predicted kinematic quantities up- and downstream of the rotor disc is quite satisfactory. However, the blade section drag to lift ratio and hence the power coefficient vary with the turbulence model chosen. Moreover, the experimentally determined power coefficient is considerably lower as predicted by all methods. However, this conclusion is somewhat preliminary since the existing experimental data set needs to be extended.
Supercritical Carbon Dioxide Brayton Cycle Development Overview
Authors: Kimball Kenneth J. , Rahner Kevin D. , Nehrbauer Joseph P. , Clementoni Eric M. 
Published: November 2013

Bechtel Marine Propulsion Corporation (BMPC) is testing a supercritical carbon dioxide (S-CO2) Brayton system at the Bettis Atomic Power Laboratory. The 100 kWe Integrated System Test (IST) is a two shaft recuperated closed Brayton cycle with a variable speed turbine driven compressor and a constant speed turbine driven generator using S-CO2 as the working fluid. The IST was designed to demonstrate operational, control and performance characteristics of an S-CO2 Brayton power cycle over a wide range of conditions. The IST design includes a comprehensive instrumentation and control system to facilitate precise control of loop operations and to allow detailed evaluation of component and system performance. A detailed dynamic performance model is being used to predict IST performance, support test procedure development and to evaluate test results.
An overview of IST testing progress and plans is provided. Testing in the IST was initiated in 2012. Initial test operations included successful system startup, initial transition to electrical power generation and increased power operations using independent speed control of the turbomachinery. Results of testing completed to date and future testing plans will be summarized.
Startup and Operation of a Supercritical Carbon Dioxide Brayton Cycle
Authors: Clementoni Eric M. , Cox Timothy L. , Sprague Christopher P. 
Published: November 2013

Bechtel Marine Propulsion Corporation (BMPC) is testing a supercritical carbon dioxide (S-CO2) Brayton system at the Bettis Atomic Power Laboratory. The 100 kWe Integrated System Test (IST) is a two shaft recuperated closed Brayton cycle with a variable speed turbine driven compressor and a constant speed turbine driven generator using S-CO2 as the working fluid. The IST was designed to demonstrate operational, control and performance characteristics of an S-CO2 Brayton power cycle over a wide range of conditions.
Initial operation of the IST has proven a reliable method for startup of the Brayton loop and heatup to normal operating temperature (570°F). An overview of the startup process, including initial loop fill and charging, and heatup to normal operating temperature is presented. Additionally, aspects of the IST startup process which are related to the loop size and component design which may be different for larger systems are discussed.
Application of a Statistical Methodology for Gas Turbine Degradation Prognostics to Alstom Field Data
Authors: Venturini Mauro , Therkorn Dirk 
Published: November 2013

In this paper, a prognostic methodology is applied to gas turbine field data to assess its capability as a predictive tool for degradation effects. On the basis of the recordings of past behavior, the methodology provides a prediction of future performance, i.e. the probability that degradation effects are at an acceptable level in future operations. The analyses carried out in this paper consider two different parameters (power output and compressor efficiency) of three different Alstom gas turbine power plants (gas turbine type GT13E2, GT24 and GT26). To apply the prognostic methodology, site specific degradation threshold values were defined, to identify the time periods with acceptable degradation (i.e. higher-than-threshold operation) and the time periods where maintenance activities are recommended (i.e. lower-than-threshold operation).
This paper compares the actual distribution of the time points until the degradation limit is reached (discrete by nature) to the continuously varying distribution of the time points simulated by the probability density functions obtained through the prognostic methodology. Moreover, the reliability of the methodology prediction is assessed for all the available field data of the three gas turbines and for two values of the threshold. For this analysis, the prognostic methodology is applied by considering different numbers of degradation periods for methodology calibration and the accuracy of the next forecasted trends is compared to the real data.
Finally, this paper compares the prognostic methodology prediction to a “purely deterministic” prediction chosen to be the average of the past time points of higher-than-threshold operations.
The results show that, in almost all cases, the prognostic methodology allows a better prediction than the “purely deterministic” approach for both power and compressor efficiency degradation. Therefore, the prognostic methodology seems to be a robust and reliable tool to predict gas turbine power plant “probabilistic” degradation.
Effect of Inlet Swirl on the Model Leading Edge of Turbine Vane
Authors: Yin Hong , Qin Yanmin , Ren Jing , Jiang Hongde 
Published: November 2013

Lean premixed combustion technology has been widely adopted in heavy duty and industrial gas turbine combustor. To enhance mixing and stabilize the flame, the large recirculation zone is built up by introducing strong swirling flow, which causes non-uniform flow field and has effect on the first stage vane, especially the leading edge.
This paper investigates the effect of swirling flow on the downstream vane film cooling. Test rig consists of a swirler nozzle (swirl number equals 0.45) and a model leading edge with three rows of film cooling holes. Five-hole probe and pressure sensitive paint measurements were carried out. The operating conditions range includes three blowing ratios, two density ratios of cooling flow and two distances between the swirler and the model leading edge. Numerical simulations were also conducted and compared with the accumulated experimental data.
Results show that the stagnation line of the model leading edge under swirling inlet flow condition is obviously altered compared with uniform inflow. Dividing the test model into three sections, film cooling effectiveness distribution has distinct characteristics in each section. Both ends of the model are mainly influenced by the flow direction. However the middle section performs differently since the vortex core impingement directly disturbs the film cooling ejection. Furthermore, detailed computational analysis reveals the swirling flow character and that the combined effect of total pressure and flow angle distribution dominates the film cooling of middle section.
Direct Measurements of Overall Effectiveness and Heat Flux on a Film Cooled Test Article at High Temperatures and Pressures
Authors: Lawson S. A. , Straub D. L. , Beer S. , Casleton K. H. , Sidwell T. 
Published: November 2013

The energy requirements associated with recovering greenhouse gases from Integrated Gasification Combined Cycle (IGCC) or Natural Gas Combined Cycle (NGCC) power plants are significant. The subsequent reductions in overall plant efficiency also result in a higher cost of electricity. In order to meet the future demand for cleaner energy production, this research is focused on improving gas turbine efficiency through advancements in gas turbine cooling capabilities.
For this study, an experimental approach was developed to quantify overall effectiveness and net heat flux reduction for a film-cooled test article at high temperature and pressure conditions. A major part of this study focused on validating an advanced optical thermography technique capable of distinguishing between emitted and reflected radiation from film-cooled test articles exposed to exhaust gases in excess of 1000°C and 5 bar. The optical thermography method was used to acquire temperature maps of both external and internal wall temperatures on a test article with fan-shaped film cooling holes. The overall effectiveness and heat flux were quantified with one experiment. The optical temperature measurement technique was capable of measuring wall temperatures to within ±7.2°C. Uncertainty estimates showed that the methods developed for this study were capable of quantifying improvements in overall effectiveness necessary to meet DOE program goals. Results showed that overall effectiveness increased with an increase in blowing ratio and a decrease in mainstream gas pressure while heat flux contours indicated consistent trends.
The Nonlinear Harmonic Method Applied to the Combined Effects of Multi-Row Unsteady Flows
Authors: Vilmin S. , Lorrain E. , Debrabandere F. , Tartinville B. , Capron A. , Hirsch Ch. 
Published: November 2013

The nonlinear harmonic method (NLH) and its extension to the modeling of the clocking effects can simulate the unsteady flows in multistage machines at drastically reduced CPU costs.
The blade row interactions that are reproduced are those between adjacent rotors and stators and also between successive rotors or successive stators. At an additional level of complexity, it appears that in stator1 / rotor / stator2 configurations the amplitude of the perturbation associated with a blade passing frequency (BPF) in a row is not only created by the adjacent row but is also modified in space by the interaction of the periodic disturbances coming from the other two rows. For instance, the spatial modes of the periodic disturbance in stator2 are provoked not only by the interaction with the adjacent rotor but also by an additional interaction with the periodic flow coming from stator1.
The present paper introduces a method that enables the identification of these modes for a general configuration row1 / row2 / row3. Any row can be a stator or a rotor and the time-varying disturbances are not only produced by the interaction with the adjacent row but also with the other rows. In particular, this is validated and illustrated for the calculation of the unsteady effects provoked in contra-rotating open rotors (CROR) by the engine pylon. Results are also shown for stator/rotor/stator configurations that shows the effects of clocking on the time harmonics.