OBJECTIVETo compare total immunoglobulin (Ig) E assay performance characteristics between Abbott Architect and Siemens Immulite test systems. Reference intervals were also determined for both ...platforms in an American population of healthy adults.METHODSAgreement of the two total IgE assays was evaluated in a cohort of 331 subjects with normal complete blood count (CBC) and comprehensive metabolic panel (CMP) results. Reference intervals were established in 302 subjects after exclusion of atopic individuals on the Abbott Architect and Siemens Immulite test systems.RESULTSWe demonstrated a 32% positive bias for total IgE quantitation on the Siemens Immulite platform compared to the Abbott Architect, despite both methods calibrated against the same WHO international reference material (75-502), Furthermore, a the upper limit of the reference interval (95th percentile) was determined to be higher for the Siemens Immulite assay compared to the Abbott Architect (132 and 102 IU/mL, respectively).CONCLUSIONDespite the use of a common WHO reference material for total IgE assay calibration, significant differences in quantitation was observed between two FDA-cleared test systems. Given that, it is warranted for clinical laboratories to verify vendor established reference intervals and adjust accordingly based on internal assessment of the normal range.
•An exergetic evaluation of the Siemens H-Class and F-Class CCPP is conducted.•The H-Class CCPP shows a better thermodynamic performance and higher profitability.•A comparative exergoeconomic ...evaluation is conducted on both processes.•The gas turbine system has the highest cost contribution among all units.•Levelized cost of electricity is reduced within an exergoeconomic optimization.
Combined-cycle power plants are one of the main pillars of the global power sector. Worldwide, different stakeholders are on the race of developing highly efficient power plants through investing in metallurgical, thermodynamic, and technological developments. The purpose of this study is a comprehensive exergoeconomic evaluation and comparison of two cases of the latest combined-cycle power plant generation - the triple pressure F-Class and H-Class technologies of the Siemens AG. Taking into consideration the specific design differences, rigorous simulations are set up by implementing real plant data prior to an application of exergetic, economic and exergoeconomic analyses to evaluate the processes. The exergy analysis shows a higher exergetic efficiency of 58.3% for the H-Class, while this value is calculated to be 56% for the F-Class. The NPV of the H-Class exceeds that of the F-Class by 69% after 20 years of operation. Accordingly, the total capital investment of the H-Class is recovered one and a half years earlier. The levelized costs of electricity generated by the H-Class and F-Class are 31.7 $/MWh and 32.5 $/MWh, respectively. The exergoeconomic evaluation demonstrates that on the component basis the gas turbine system has the highest contribution to the overall cost caused by investment and irreversibilities within the processes. Design improvements obtained from an iterative exergoeconomic optimization of some important design parameters (decision variables) result in further reduction of the levelized cost of electricity for the H-Class design.
INTRODUCTION
The standardized uptake value ratio (SUVR) is used to measure amyloid beta–positron emission tomography (Aβ‐PET) uptake in the brainDifferences in PET scanner technologies and image ...reconstruction techniques can lead to variability in PET images across scanners. This poses a challenge for Aβ‐PET studies conducted in multiple centers. The aim of harmonization is to achieve consistent Aβ‐PET measurements across different scanners. In this study, we propose an Aβ‐PET harmonization method of matching spatial resolution, as measured via a barrel phantom, across PET scanners. Our approach was validated using paired subject data, for which patients were imaged on multiple scanners.
METHODS
In this study, three different PET scanners were evaluated: the Siemens Biograph Vision 600, Siemens Biograph molecular computed tomography (mCT), and Philips Gemini TF64. A total of five, eight, and five subjects were each scanned twice with 18F‐NAV4694 across Vision‐mCT, mCT‐Philips, and Vision‐Philips scanner pairs. The Vision and mCT scans were reconstructed using various iterations, subsets, and post‐reconstruction Gaussian smoothing, whereas only one reconstruction configuration was used for the Philips scans. The full‐width at half‐maximum (FWHM) of each reconstruction configuration was calculated using 18F‐filled barrel phantom scans with the Society of Nuclear Medicine and Molecular Imaging (SNMMI) phantom analysis toolkit. Regional SUVRs were calculated from 72 brain regions using the automated anatomical labelling atlas 3 (AAL3) atlas for each subject and reconstruction configuration. Statistical similarity between SUVRs was assessed using paired (within subject) t‐tests for each pair of reconstructions across scanners; the higher the p‐value, the greater the similarity between the SUVRs.
RESULTS
Vision‐mCT harmonization: Vision reconstruction with FWHM = 4.10 mm and mCT reconstruction with FWHM = 4.30 mm gave the maximal statistical similarity (maximum p‐value) between regional SUVRs. Philips‐mCT harmonization: The FWHM of the Philips reconstruction was 8.2 mm and the mCT reconstruction with the FWHM of 9.35 mm, which gave the maximal statistical similarity between regional SUVRs. Philips–Vision harmonization: The Vision reconstruction with an FWHM of 9.1 mm gave the maximal statistical similarity between regional SUVRs when compared with the Philips reconstruction of 8.2 mm and were selected as the harmonized for each scanner pair.
CONCLUSION
Based on data obtained from three sets of participants, each scanned on a pair of PET scanners, it has been verified that using reconstruction configurations that produce matched‐barrel, phantom spatial resolutions results in maximally harmonized Aβ‐PET quantitation between scanner pairs. This finding is encouraging for the use of PET scanners in multi‐center trials or updates during longitudinal studies.
Highlights
Question: Does the process of matching the barrel phantom‐derived spatial resolution between scanners harmonize amyloid beta–standardized uptake value ratio (Aβ‐SUVR) quantitation?
Pertinent findings: It has been validated that reconstruction pairs with matched barrel phantom‐derived spatial resolution maximize the similarity between subjects paired Aβ‐PET (positron emission tomography) SUVR values recorded on two scanners.
Implications for patient care: Harmonization between scanners in multi‐center trials and PET camera updates in longitudinal studies can be achieved using a simple and efficient phantom measurement procedure, beneficial for the validity of Aβ‐PET quantitation measurements.
Many magnetic resonance imaging (MRI) measures are being studied longitudinally to explore topics such as biomarker detection and clinical staging. A pertinent concern to longitudinal work is MRI ...scanner upgrades. When upgrades occur during the course of a longitudinal MRI neuroimaging investigation, there may be an impact on the compatibility of pre- and post-upgrade measures. Similarly, subject motion is another issue that may be detrimental to MRI work and embedding volumetric navigators (vNavs) within acquisition sequences has emerged as a technique that allows for prospective motion correction. Our research group recently underwent an upgrade from a Siemens MAGNETOM 3T Tim Trio system to a Siemens MAGNETOM 3T Prisma Fit system. The goals of the current work were to: 1) investigate the impact of this upgrade on commonly used structural imaging measures and proton magnetic resonance spectroscopy indices (“Prisma Upgrade protocol”) and 2) examine structural imaging measures in a sequence with vNavs alongside a standard acquisition sequence (“vNav protocol”). While high reliability was observed for most of the investigated MRI outputs, suboptimal reliability was observed for certain indices. Across the scanner upgrade, increases in frontal, temporal, and cingulate cortical thickness (CT) and thalamus volume, along with decreases in parietal CT and amygdala, globus pallidus, hippocampus, and striatum volumes, were observed. No significant impact of the upgrade was found in 1H-MRS analyses. Further, CT estimates were found to be larger in MPRAGE acquisitions compared to vNav-MPRAGE acquisitions mainly within temporal areas, while the opposite was found mostly in parietal brain regions. The results from this work should be considered in longitudinal study designs and comparable prospective motion correction investigations are warranted in cases of marked head movement.
•Heat transfer mechanisms affecting surface temperature of the rod are investigated.•Transition points of mixed convection and natural convection is GrRed2=100.•Operational and geometric factors for ...temperature homogeneity are discussed.
The temperature homogeneity at polysilicon rods significantly affects the uniformity growth of the polysilicon rod and the product quality in reduction furnace. The heat transfer phenomena on the rod surface includes electric heating, radiation heat transfer, convection heat transfer, heat conduction and reaction heat. In this paper, a representative configuration (RC) of heat transfer model was selected from a “honeycomb” industrial furnace. The flow patterns with different outlets have been numerically investigated and the dependency of surface temperature distribution on the inlet velocity as well as the geometric parameters has been investigated. Gr/Red2 = 100 is set as the transition point determining the natural convection and mixed convection heat transfer. The results indicated that the axial temperature difference at the rod surface has close relationship with the complicated convection heat transfer. With rods growth, the main difference of local heat loss is caused by radiation rather than convection heat transfer.
PurposeThe digitization process has increased the pressure on large firms to transform. However, current frameworks on digital transformation are not well explaining what factors contribute to, or ...hinder, a firm's digital transformation. Innovation diffusion theories could complement existing frameworks, and for this reason, the purpose of this paper is to expand the existing body of knowledge on what contributes to, or hinders, an industrial firm's digital transformation by applying a validated framework based on innovation diffusion theories on two pioneer cases: General Electric and Siemens EHR/Health Services.Design/methodology/approachThe framework used in this paper is based on several years' empirical studies and iterative literature reviews on innovation diffusion theories. Further, each use case is based on literature reviews and unique empirical data, collected by the authors of this paper as a result of taking active part of respective company's multi-years transformation.FindingsCommon drivers of, and clear inhibitors to the two firms' transformation, were identified. The innovation diffusion framework was found to work very well in identifying those factors.Research limitations/implicationsThe implications are that researchers better can analyze/explain a digital transformation of a firm, and business managers can better plan or improve their firms' transformation processes.Originality/valueThe theoretical contributions of this paper are two: first, complement existing frameworks with a validated framework for innovation diffusion; second, provide an extension of our body of knowledge on factors that contributes to, or hinders, industrial firm's digital transformation.
•ELFTM aids prognostic evaluation in patients with advanced liver fibrosis in NASH.•The ELF score comprises results of 3 fibrosis markers, HA, PIIINP, and TIMP-1.•The Atellica IM Analyzer was used ...for analytical performance of 3 analytes and ELF.•Detection capability, precision, interference, linearity, hook effect, were studied.•All predetermined requirements were met making the assay fit for clinical use.
The Enhanced Liver Fibrosis (ELFTM) Test comprises 3 direct serum markers of fibrosis—hyaluronic acid (HA), amino-terminal pro-peptide of type III procollagen (PIIINP), and tissue inhibitor of matrix metalloproteinase 1 (TIMP-1)—whose results are combined in an algorithm to generate the ELF score. Outside the U.S., the ELF Test and score are CE marked for assessment of liver fibrosis severity in patients with signs, symptoms, or risk factors of chronic liver disease to support diagnosis of fibrosis staging or prognosis for likelihood of progression to cirrhosis and liver-related clinical events. In the U.S., the FDA granted de novo marketing authorization to aid prognostic evaluation of disease progression (to cirrhosis and liver-related clinical events) in nonalcoholic steatohepatitis patients with advanced liver fibrosis. We describe the analytical performance of the ELF analytes and score on the Atellica® IM Analyzer.
Clinical and Laboratory Standards Institute protocols were followed for detection capability (limits of blank LoB, detection LoD, and quantitation LoQ), precision, interference, linearity, hook effect, and ELF reference interval.
All parameters met predetermined requirements: HA (LoB 1.00 ng/mL, LoD 2.00 ng/mL, LoQ 3.00 ng/mL); PIIINP (LoB 0.50 ng/mL, LoD 0.75 ng/mL, LoQ 1.00 ng/mL); TIMP-1 (LoB 3.0 ng/mL, LoD 4.0 ng/mL, LoQ 5.0 ng/mL). Across the 3 assays, repeatability was ≤5.4% CV; within-lab precision was ≤8.5% CV. ELF score repeatability was ≤0.6% CV, within-lab precision ≤1.3% CV, and reproducibility ≤1.1% CV. Good correlation was obtained between the Atellica IM ELF and ADVIA Centaur ELF Tests (y = 1.01x − 0.22, r = 0.997). Assays were linear across analytical measuring ranges.
Analytical performance validation results for the ELF Test and ELF score were excellent making the test acceptable for routine clinical use.
PDF
