Laboratory Performance Evaluation Research Articles

The EuroFlow PIDOT external quality assurance scheme: enhancing laboratory performance evaluation in immunophenotyping of rare lymphoid immunodeficiencies.

The development of External Quality Assessment Schemes (EQAS) for clinical flow cytometry (FCM) is challenging in the context of rare (immunological) diseases. Here, we introduce a novel EQAS monitoring the primary immunodeficiency Orientation Tube (PIDOT), developed by EuroFlow, in both a 'wet' and 'dry' format. This EQAS provides feedback on the quality of individual laboratories (i.e.,accuracy, reproducibility and result interpretation), while eliminating the need for sample distribution. In the wet format, marker staining intensities (MedFIs) within landmark cell populations in PIDOT analysis performed on locally collected healthy control (HC) samples, were compared to EQAS targets. In the dry format, participants analyzed centrally distributed PIDOT flow cytometry data (n=10). We report the results of six EQAS rounds across 20 laboratories in 11 countries. The wet format (212 HC samples) demonstrated consistent technical performance among laboratories (median %rCV on MedFIs=34.5 %; average failure rate 17.3 %) and showed improvement upon repeated participation. The dry format demonstrated effective proficiency of participants in cell count enumeration (range %rCVs 3.1-7.1 % for the major lymphoid subsets), and in identifying lymphoid abnormalities (79.3 % alignment with reference). The PIDOT-EQAS allows laboratories, adhering to the standardized EuroFlow approach, to monitor interlaboratory variations without the need for sample distribution, and provides them educational support to recognize rare clinically relevant immunophenotypic patterns of primary immunodeficiencies (PID). This EQAS contributes to quality improvement of PID diagnostics and can serve as an example for future flow cytometry EQAS in the context of rare diseases.

Impact sound insulation performance of floor coverings in a heavyweight reference floor with a floating floor

This study investigates the impact sound reduction performance of floor coverings used on the heavyweight standard floor of a floating floor structure in comparison with bare slab testbeds through on-site experiments. The laboratory performance evaluation of floor coverings designates only a bare slab between 100 mm and 160 mm as the heavyweight reference floor according to Annex C in ISO 10140-5. However, the recent expansion of over-floor heating systems has led to an increased need for understanding the impact sound reduction performance of floor coverings on floating floors, to enhance occupants' thermal comfort. In this study, it was measured the heavyweight and lightweight floor impact sound reduction levels of various floor covering test specimens in testbeds with different thicknesses of bare slabs and actual apartment houses with floating floors applied. The reduction rate for each frequency band was determined before and after installing floor coverings including single number quantity in accordance with ISO 717-2. Additionally, the impact of heavyweight reference floor conditions on quantifying the sound performance of floor coverings was discussed.

The 2023 National Proficiency Test for molecular detection of shrimp infectious myonecrosis virus (IMNV) in China

Infectious myonecrosis virus (IMNV), an emerging virus that can cause severe viral disease in penaeid shrimp, was first confirmed to have spread to China in 2020. In order to standardize diagnostic procedures and reliable detection capability, and to evaluate the performances of aquatic clinical diagnostic laboratories, the competent authority has launched a proficiency test (PT) scheme for the molecular detection of IMNV in China from the year of 2023. In the ring test of IMNV-PT 2023, five tissue samples containing different concentrations of IMNV were provided as a panel of test samples. A total of 68 laboratories participated in the PT test of qualitative and quantitative analysis of the five samples using standard molecular assays. The results showed that 92.65 % (63/68) of the participants correctly reported all samples in the panel using Real-time reverse transcription PCR and 62 participants achieved satisfactory results, one participant using conventional PCR and four participants had not completed the test. Out of the 62 participants in the z-scores analysis, 88.71 % (55/62) achieved acceptable ZB-scores, with two outlier laboratories and five laboratories being questionable. Additionally, 98.39 % (61/62) achieved ZW-scores, with only one laboratory being questionable. Furthermore, the national PT conducted in the present study proved to be an effective tool for evaluating laboratory performance in IMNV molecular testing. This assessment can aid in improving the capabilities of IMNV molecular testing of the participating laboratories, and also provided technical supporting to enhance the national response to IMN outbreaks.

Laboratory and Field Performance Evaluation of NMAS 9.5, 8.0, and 5.6 mm SMA Mixtures for Sustainable Pavement

This study evaluates the laboratory and field performance of stone mastic asphalt (SMA) mixtures with nominal maximum aggregate sizes (NMAS) of 9.5, 8.0, and 5.6 mm. Aggregates and fine aggregates of these sizes were produced using an impact crusher and a polyurethane screen. Mix designs for SMA overlays on aged concrete pavement were developed. Laboratory tests assessed rutting performance using full-scale accelerated pavement testing (APT) equipment and reflective cracking resistance using an asphalt mixture performance tester (AMPT). Field evaluations included noise reduction using CPX equipment, skid resistance using SN equipment, and bond strength using field cores. Results showed that for 8.0 mm SMA mixtures to achieve the same rutting performance as 9.5 mm SMA, PG76-22 grade binder was required, whereas 5.6 mm SMA required PG82-22. The 8.0 and 5.6 mm SMA mixtures showed 22.2% and 25% reduced crack progression, respectively, compared with the 9.5 mm SMA mixtures. Field evaluations indicated that 8.0 mm and 5.6 mm SMA pavements reduced tire–pavement noise by 1.7 and 0.8 dB, increased skid resistance by 8.5% and 2.0%, and enhanced shear bond strength by 150%, compared with 9.5 mm SMA. Overall, the 8.0 mm SMA mixture on aged concrete pavement demonstrated superior durability and functionality toward sustainable pavement systems.

Field and Laboratory Performance Evaluation of Cement Treated Cold Recycled Asphalt Pavement Mixtures

Field and Laboratory Performance Evaluation of Cement Treated Cold Recycled Asphalt Pavement Mixtures

Application of Low-Temperature Temporary Plugging Agents in Coalbed Methane Volume Fracturing

Currently, unconventional oil and gas fields employ volume fracturing technology, and temporary plugging and diversion techniques have become one of the main methods for increasing production. The Mixi coalbed methane block in Yibing has a formation vertical depth of 800-1000 meters and a relatively low average formation temperature of 30 degrees Celsius. The temporary plugging agents currently in use face challenges during reservoir stimulation, including difficulty in withstanding pressure differentials, poor degradability, and significant reservoir damage, resulting in unsatisfactory implementation effects. Therefore, the water-soluble temporary plugging agent RD-1 was selected as the preferred option. Laboratory performance evaluation experiments have demonstrated that this temporary plugging agent exhibits good sealing and degradation properties. Field trials have shown good temporary plugging and diversion effects, with noticeable pressure increase during plugging and significantly improved stimulation volume. It has demonstrated good applicability in coalbed methane volume fracturing, accumulating valuable experience for efficient development of this block.

Comparison of Thrombophilia Assay Results for the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee Plasma Standard from Different External Quality Assessment Providers-for the External Quality Assurance in Thrombosis and Haemostasis Group.

External quality assessment (EQA) is used to evaluate laboratory performance in tests of hemostasis; however, some esoteric tests are performed by too few centers in any one EQA program to allow valid statistical assessment. To explore the feasibility of pooling data from several EQA providers, an exercise was carried out by the External Quality Assurance in Thrombosis and Haemostasis group, using the International Society on Thrombosis and Haemostasis Scientific and Standardization Committee (SSC) plasma standard for thrombophilia screening assays. Six EQA providers took part in this exercise, distributing the SSC plasma standard as a "blinded" sample to participants for thrombophilia tests between November 2020 and December 2021. Data were collected by each provider, anonymized, and pooled for analysis. Results were analyzed as overall results from each EQA provider, and by kit/method-specific comparisons of data from all providers pooled together. For each parameter, median results and range were determined. Over 1,250 sets of data were returned in the six EQA programs. The overall medians (all data pooled) were <4% of the assigned values for each parameter with the exception of protein C activity by clot-based assay. Method-related differences in median results were observed for free protein S antigen and protein S activity-a pattern seen across data from the different EQA providers. Antithrombin antigen results reported in mg/dL provided an example where small numbers of results for a single EQA provider may be supplemented by pooling data from multiple providers with good agreement seen among results reported by the different EQA providers. This study demonstrated that a multicenter EQA provider collaboration can be carried out and demonstrated benefit for assays with smaller number of participants. In addition, results showed good agreement with the assigned values of the SSC plasma standard. Further exercises for tests performed by only small numbers of laboratories can be planned.

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Evaluating laboratory performance in Dengue virus detection by using RT-qPCR: Analysis of a Brazilian external quality assessment program results

Evaluation of quality indicators in microbiology and infectious disease serology laboratory: A study from a tertiary cancer care centre in Gujarat, India

Introduction: Quality indicators (QIs) are important for the monitoring and evaluation of laboratory performance at pre-analytical, analytical, and post-analytical phases. Errors in the laboratory arise more frequently before and after the analysis of samples. The total testing process (TTP) therefore needs to be evaluated for good laboratory performance. A good quality indicator should give information about the performance of a process, thereby governing the quality of services.Objective: To analyse TTP and QIs for a period of six years of screening of laboratory performance.Methods: This retrospective analysis was conducted for the period 2017 to 2022. QIs at pre-analytical (12), analytical (04) and post-analytical (03) phases were defined and analysed on a monthly basis. The laboratory followed the guidelines of the International Organization for Standardization (ISO) 15189:2012 to identify errors in all sections.Results: A total of 259,694 samples were received during the study period. A total of 628,817 tests were performed. The overall error rate was 1.25/1000 tests. Error in the pre-analytic phase was 0.96/1000 tests, the commonest being haemolysed samples. Error in the analytical phase was 0.33/1000 tests. The error of postanalytical phase was 0.48/1000 tests with turn round time (TAT) outliers being the commonest.Conclusion: Amongst all phases of QIs, errors were minimum in the analytical phase. Continuous monitoring and analysis of QIs helps in identification of common errors in the laboratory. Corrective measures will help to improve quality of the laboratory services, and hence the patient outcome. Regular training, evaluation of technical staff, regular preventive maintenance and calibration of all analytical instruments helps in reducing the errors.

Evaluate laboratory performance pre- and post-COVID pandemic at Major Hospital in Sri Lanka- A case study

Evaluate laboratory performance pre- and post-COVID pandemic at Major Hospital in Sri Lanka- A case study

Laboratory and Field Performance Evaluation of Cracking of Airfield Warm Mix Asphalt with Reclaimed Asphalt Pavement at the National Airport Pavement and Materials Research Center

The U.S. Federal Aviation Administration is exploring initiatives to decrease transportation greenhouse gas emissions by developing carbon reduction strategies, including using low-embodied carbon materials, such as reclaimed asphalt pavement (RAP), in airport pavement construction. However, verifying RAP’s viability for airfield pavements with laboratory and field performance measures is essential. This study compared the cracking susceptibility of a P-401 hot mix asphalt and warm mix asphalt (WMA)+RAP airfield mixes using laboratory performance tests and conducted a preliminary evaluation of pavement responses from accelerated pavement testing (APT) fatigue tests. The observations and outcomes presented in this paper found that adding 20% of recycled materials with WMA additives had a decreasing impact in mix performance but did not overly affect the asphalt mix properties, as cracking properties from the different test procedures were found with comparable outcomes. Additional observations from strain gauges and temperature probes in the National Airport Pavement and Materials Research Center test cycle 2 APT fatigue test sections showed that the maximum tensile strains in the WMA surface lane 5 south section were consistently higher than those in the WMA+RAP lane 6 south section, which may be because of the higher load level that it was exposed. Additionally, the hardened or aged RAP binder in the entire lane 6 south section may have increased its stiffness, resulting in lower strain levels than in the lane 5 south section. Notably, both sections showed an increase in tensile strains with an increase in asphalt concrete temperature, which confirmed the temperature dependency behavior of asphalt concrete.

Efficiency assessment of variable speed air source heat pump heating systems: A hybrid data-driven and theoretical approach

The laboratory performance evaluations of variable speed air source heat pumps typically adhere to standard steady-state test methods, which neglect the dynamic characteristics associated with actual operation. The evaluation of energy efficiency influencing factors in the actual installed project is crucial for guiding improvements in energy efficiency. The aim of this paper is to identify any loss of dynamic operation, a hybrid approach combining data-driven and theoretical methodologies for modeling and assessing the efficiency of variable speed air source heat pump heating systems based on operation state decomposition. The innovation of this study lies in the abandonment of the previous method for constructing performance maps based on compressor speeds, and instead adopting the concept of thermodynamic perfectibility is introduced to characterize the steady-state performance, serving as a benchmark for identifying operational losses including unsteady-state operation loss, stand-by loss, and defrosting loss based on the actual operating state of the variable speed air source heat pumps. The findings from six monitoring projects indicate that the failure to consider crucial dynamic characteristics can lead to deviations of 4.7%–36.5% from actual performance. These deviations can be attributed to various factors, including a loss of up to 27.2% due to unsteady operation, a standby loss of up to 7.9%, and an unnecessary defrosting operation resulting in a defrosting loss of up to 8.9%.

Monitoring SARS-CoV-2 genetic variability: A post-market surveillance workflow for combined bioinformatic and laboratory evaluation of commercial RT-PCR assay performance.

The speed at which Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) is mutating has made it necessary to frequently assess how these genomic changes impact the performance of diagnostic real-time polymerase chain reaction (RT-PCR) assays. Herein, we describe a generic three-step workflow to assess the effect of genomic mutations on inclusivity and sensitivity of RT-PCR assays. Sequences collected from the Global Initiative on Sharing All Influenza Data (GISAID) were mapped to a SARS-CoV-2 reference genome to evaluate the position and prevalence of mismatches in the oligonucleotide-binding sites of the QIAstat-Dx, an RT-PCR panel designed to detect SARS-CoV-2. The frequency of mutations and their impact on melting temperature were assessed, and sequences flagged by risk-based criteria were examined in vitro. Out of 8,900,393 SARS-CoV-2 genome sequences analyzed, only 173 (0.0019%) genomes contained potentially critical mutations for the QIAstat-Dx; follow-up in-vitro testing confirmed no impact on the assays' performance. The current study demonstrates that SARS-CoV-2 genetic variants do not affect the performance of the QIAstat-Dx device. It is recommended that manufacturers incorporate this workflow into obligatory post-marketing surveillance activities, as this approach could potentially enhance genetic monitoring of their product.

Study on the preparation and mechanical and fatigue properties of alkali excited recycled concrete

This study aims to explore the preparation process of alkali excited recycled concrete, and evaluate its performance in terms of mechanical and fatigue properties, so as to provide theoretical and practical support for the application of sustainable development and environmental protection building materials. Laboratory test and performance evaluation were used to prepare alkali-stimulated recycled concrete specimens with different proportions by adjusting fly ash, alkali activator and water solid ratio in recycled concrete. Then, the mechanical properties of the specimen were tested, including the influence of the cementing material on its compressive strength and the influence of the aggregate quality on its compressive strength. Finally, the fatigue life test is used to analyze the fatigue performance of alkali stimulated recycled concrete, and the influence of different ages and different stress levels on fatigue damage performance of alkali stimulated recycled concrete specimens is studied. The experimental results show that the mechanical properties of recycled concrete can be significantly improved by using alkali excited recycled concrete preparation technology. It is found that under the same stress ratio, with the increase of age, the corresponding fatigue life will increase, the flexural tensile strength will increase, and the fatigue resistance will improve. At the same age, the fatigue life of specimens decreases with the increase of stress ratio, and the flexural tensile strength and fatigue resistance remain unchanged. This study proves the effectiveness of alkali excited recycled concrete preparation technology in improving the mechanical properties and fatigue properties of recycled concrete. Alkali stimulated recycled concrete is not only conducive to resource reuse, reduce the impact of waste on the environment, but also provides a new choice for the sustainable development of building materials. However, further research and application are needed to promote the widespread application of alkali excited recycled concrete in engineering practice.

Laboratory performance evaluation of porous asphalt mixture containing recycled concrete aggregate and fly ash

This study performed laboratory experiments to evaluate the performance of porous asphalt mixtures (PAMs) containing recycled concrete aggregate (RCA). One open aggregate gradation with Class C fly ash as the filler, granite aggregate, two binder types (PG 67–22 and PG 76–22), and four RCA contents (0%, 10%, 20%, and 30% by mass of aggregates in the sieve size range of 4.75 to 9.5 mm) were included in the experiments. The mixture properties evaluated include permeability and air-void content, Marshall stability and flow, indirect tensile strength, moisture susceptibility, Cantabro abrasion loss, macrotexture, and sound absorption coefficient. The study found that using a blend of granite and RCA in a PAM led to better performance in terms of indirect tensile strength, stiffness, moisture resistance, and resistance to raveling. This was particularly confirmed for PAMs with an unmodified PG 67–22 binder. The mixture that contained 30% RCA performed the most satisfactorily, with an indirect tensile strength of 0.81 MPa and a Marshall stability of 23 kN at 25 °C. These values were 37.5% and 15%, respectively, higher than the control mixture. Based on these results, the study recommends the use of 30% RCA in PAMs for the friction course of a highway pavement or the porous surface of a porous pavement.

Laboratory Characteristics, Performance Evaluation, and Agency Cost Analysis of Cold-Recycled Asphalt Mixtures

Laboratory Characteristics, Performance Evaluation, and Agency Cost Analysis of Cold-Recycled Asphalt Mixtures

Preanalitik Hataların Altı Sigma Metodu ve Pareto Prensibi Analizi ile Değerlendirilmesi

Aim: In this study, we aimed to evaluate the preanalytical errors over a five year period using the Six Sigma methodology and Pareto Principle in the clinical biochemistry laboratory. Methods: Five-year sample rejection data between January 2015 and December 2019 in the clinical biochemistry laboratory were analyzed and classified according to the reasons for rejection. Six Sigma levels for the total and each preanalytical error were calculated with Westgard online formula. Preanalytical errors were evaluated according to their frequencies ranks and percentages with Pareto's principle. Results: The overall rate of five-year total critical preanalytical errors was 1.91% and the sigma level was 3.6. According to Pareto's chart, the three most common errors among the five-year preanalytical rejections were clotted sample (42.49%, sigma value:4), insufficient sample (23.53%, sigma value:4.2), and wrong container (8.01%, sigma value:4.5). Conclusion: Six Sigma is a quality management methodology used to evaluate laboratory performance processes according to universal quality criteria. Calculated sigma values of preanalytical errors in our laboratory were within the acceptable range. However, planned regulatory activities for frequently observed preanalytical errors should be a laboratory management strategy to reduce these error rates and improve our laboratory performance.

Chinese expert consensus on D-dimer laboratory testing and clinical application

D-dimer is a degradation product deriving from the plasmin-mediated degradation of cross-linked fibrin. It serves as a biomarker for the activation of coagulation and fibrinolysis, and has been extensively utilized in the diagnosis and treatment of various diseases. However, in recent years, issues related to D-dimer laboratory testing and its clinical application have become increasingly prominent. The lack of standardization in reports has led to confusion in both laboratory testing and clinical application. To address this, the Chinese Society on Thrombosis and Hemostasis brought together experts in the field of thrombosis and hemostasis in China to discuss and develop the 'Chinese Expert Consensus on D-Dimer Laboratory Testing and Clinical Application'. This consensus focuses on laboratory testing methods, quality requirements, performance evaluation, sample processing, analysis interference, result reports, and clinical application of D-dimer. Its aim is to optimize the key issues related to D-dimer testing in laboratories and provide guidance for the appropriate use and accurate interpretation of D-dimer in clinical settings.

Laboratory proportion design and performance evaluation of Fiber-Reinforced rubber asphalt chip seal based on multiple properties enhancement

Chip seal is an effective preventive maintenance technology for the pavement distress repair and pavement service life extension. Adding fiber or rubber powder alone has been shown to improve chip seal performance. However, the full potential of chip seal could not be attained by utilizing only fiber or rubber powder singularly. In this study, a fiber-reinforced rubber asphalt chip seal was prepared and evaluated based on multiple properties enhancement. Analysis of Variance (ANOVA) was conducted to assess the level of significant influence of rubber powder content and shearing time on the results of the penetration, softening point, ductility, and elastic recovery tests. The optimal process parameters for rubber asphalt were further analyzed and determined based on the ANOVA results. Bending beam rheometer (BBR) and rotational viscosity tests were executed to evaluate the low-temperature crack resistance and workability of the rubber asphalt. Cover, sweep, 45-degree skew shear and texture depth tests were performed to identify the optimum proportion of fiber-reinforced rubber asphalt chip seal. Tensile, temperature stability, water stability and three-point bending tests were conducted to evaluate chip seal performance. Cost analysis for mature preventive maintenance technology was carried out to evaluate equivalent annual costs. The results show that essential parameters for preparing rubber asphalt were the rubber powder content of 22.5% and the shearing time of 60 min. Moreover, the optimum proportion of fiber-reinforced rubber asphalt chip seal was determined to be 9.55 kg/m2 of aggregates, 2.3 kg/m2 of rubber asphalt, and 80 g/m2 of fiber. This study also confirmed that the fiber-reinforced rubber asphalt chip seal outperformed the rubber asphalt chip seal in terms of crack resistance, skid resistance, bonding performance, temperature stability, water stability and fatigue resistance. Combined with cost analysis, it was found that the fiber-reinforced rubber asphalt chip seal was a type of cost-effective preventive maintenance technology.

PRELIMINARY RESULTS FROM GLASGOW INTERNATIONAL RADIOCARBON INTERCOMPARISON

ABSTRACT GIRI (Glasgow International Radiocarbon Intercomparison) was designed to meet a number of objectives, including to provide an independent assessment of the analytical quality of the laboratory/measurement and an opportunity for a laboratory to participate and improve (if needed). The principles in the design of GIRI were to provide the following: (a) a series of unrelated individual samples, spanning the dating age range, (b) linked samples to earlier intercomparisons to allow traceability, (c) known age samples, to allow independent accuracy checks, (d) a small number of duplicates, to allow independent estimation of laboratory uncertainty, and (e) two categories of samples—bulk and individual—to support laboratory investigation of variability. All of the GIRI samples are natural (wood, peat, and grain), some are known age, and overall their age spans approx. &gt;40,000 years BP to modern. The complete list of sample materials includes humic acid, whalebone, grain, single ring dendro-dated samples, dendro-dated wood samples spanning a number of rings (e.g., 10 rings), background and near background samples of bone and wood. We present an overview of the results received and preliminary consensus values for the samples supporting a more in-depth evaluation of laboratory performance and variability.