scholarly journals Long-term quality assessment and monitoring of light microscope performance through accessible and reliable protocols, tools and metrics

2021 ◽  
Author(s):  
Orestis Faklaris ◽  
Leslie Bancel-Vallee ◽  
Aurelien Dauphin ◽  
Baptiste Monterroso ◽  
Perrine Frere ◽  
...  
Keyword(s):  
Quality Control ◽  
Data Processing ◽  
Light Microscope ◽  
Wide Field ◽  
Experimental Limit ◽  
Limit Values ◽  
Power Monitoring ◽  
Control Procedures ◽  
Over Time

Reliable, reproducible and comparable results are what biology requires from microscopy. To achieve that level of confidence, monitoring the stability of the microscope performance over time with standardized quality testing routines is essential for mining quantitative data. Three levels of microscope quality control procedures should be considered: i) usage of accessible and affordable tools and samples, ii) execution of easy and fast, preferably automatized, acquisition protocols, iii) analysis of data in the most automated way possible with adequate metrics for long-term monitoring. In this paper, we test the acquisition protocols on the mainly used microscope techniques (wide-field, spinning disk and confocal microscopy) with simple quality control tools. Seven protocols specify metrics on measuring the lateral and axial resolution (Point-Spread Function) of the system, field flatness, chromatic aberrations and co-registration, illumination power monitoring and stability, stage drift and positioning repeatability and finally temporal and spatial noise sources of camera detectors. We designed an ImageJ/FiJi java plugin named MetroloJ_QC to incorporate the identified metrics and automatize the data processing for the analysis. After processing and comparing the data of microscopes from more than ten imaging facilities, we test the robustness of the metrics and the protocols by determining experimental limit values. Our results give a first extensive characterization of the quality control procedures of a light microscope, with an automated data processing and experimental limit values that can be used by core facility staff and researchers to monitor the microscope performance over time.

Feasibility of centralized measurements of glycated hemoglobin in the Diabetes Control and Complications Trial: a multicenter study. The DCCT Research Group.

1987 ◽  
Vol 33 (12) ◽  
pp. 2267-2271 ◽  
Keyword(s):  
Quality Control ◽  
High Performance ◽  
Glycated Hemoglobin ◽  
Multicenter Trial ◽  
Diabetes Control ◽  
Mean Values ◽  
Hb A1c ◽  
Control Procedures ◽  
Over Time

Abstract A method for measuring glycated hemoglobin (Hb A1c) and an accompanying method of specimen transport to a central laboratory were developed for the multicenter Diabetes Control and Complications Trial (DCCT). In the DCCT, results for Hb A1c are used to assess chronic glycemic control for data collection and patient management. During the feasibility phase of the trial, central (CHL) and backup laboratories using automated, "high-performance" ion-exchange liquid-chromatographic methods were established. Whole-blood samples were stored (4 degrees C) at each of the 21 clinical centers for up to 72 h before air-express shipment to the CHL. Quality-control procedures included daily analyses of three calibration specimens. A pooled hemolysate was assayed frequently over time as a long-term quality control (LTQC). After 18 months, within- and between-run CVs were less than 6%. Mean values for split duplicate samples assayed in a masked fashion at the CHL were nearly identical. LTQC results indicated no significant assay drift over time. More than 6000 samples were assayed (mean interval between obtaining the blood sample and completing the assay: less than six days). Hb A1c evidently can be precisely and reliably measured in the context of a long-term, multicenter trial such as the DCCT.

scholarly journals Long-Term Recreational Football Training and Health in Aging

2020 ◽  
Vol 17 (6) ◽  
pp. 2087
Author(s):  
Esther Imperlini ◽  
Annamaria Mancini ◽  
Stefania Orrù ◽  
Daniela Vitucci ◽  
Valeria Di Onofrio ◽  
...  
Keyword(s):  
Quality Control ◽  
Dna Repair ◽  
Successful Aging ◽  
Protein Quality ◽  
Metabolic Diseases ◽  
Control Mechanisms ◽  
Older Subjects ◽  
Football Training ◽  
Over Time

This narrative review aims to critically analyze the effects of exercise on health in aging. Here we discuss the main clinical and biomolecular modifications induced by long-term recreational football training in older subjects. In particular, the effects induced by long-term recreational football training on cardiovascular, metabolic and musculo-skeletal fitness, together with the modifications in the muscle expression of hallmarks related to oxidative metabolism, DNA repair and senescence suppression pathways and protein quality control mechanisms will be provided. All these topics will be debated also in terms of preventing non-communicable metabolic diseases, in order to achieve successful aging over time.

scholarly journals Implementation of Real-Time Quality Control Procedures by Means of a Probabilistic Estimate of Seawater Temperature and Its Temporal Evolution

2013 ◽  
Vol 30 (3) ◽  
pp. 609-625 ◽  
Author(s):  
Giuseppe M. R. Manzella ◽  
Marco Gambetta
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Position Control ◽  
Seawater Temperature ◽  
Likelihood Method ◽  
Temperature Profiles ◽  
Quality Of Data ◽  
Control Procedures ◽  
The Mediterranean

Abstract Near-real-time quality control procedures for temperature profiles collected from ships of opportunity were implemented during the 1980s in oceans across the world and from the 1990s in the Mediterranean. In this sea, the procedures were originally based on seven steps (detection of end of profile, gross range check, position control, elimination of spikes, Gaussian smoothing and resampling at 1-m intervals, general malfunction control, and comparison with climatology), complemented with initial and final visual checks. The quality of data derived from a comparison with historical data (namely, climatology) depends on the availability of a huge amount of data that can statistically represent the mean characteristics of the seawater. A significant amount of data has been collected, and the existing temperature database in the Mediterranean can now provide more information on temporal and spatial variability at monthly and mesoscales, and an improved procedure for data quality control has now been adopted. New “best” estimates of monthly temperature profiles are calculated by using a maximum likelihood method. It has been found that more than one “best estimate” temperature can be defined in particular areas and depths, as a consequence of climate variability. Additional near-real-time control procedures have been included in order to provide information on long-term variability associated with data. This information is included in metafiles to be used for reanalysis and studies on long-term variability and changes.

Long-term retrospective control procedures for monitoring analytical performance of laboratory instruments.

1984 ◽  
Vol 30 (1) ◽  
pp. 145-149 ◽  
Author(s):  
M L Gozzo ◽  
G Barbaresi ◽  
G Giocoli ◽  
B Zappacosta ◽  
C Zuppi
Keyword(s):  
Quality Control ◽  
Reliability Index ◽  
Total Error ◽  
Statistical Procedure ◽  
Analytical Performance ◽  
Clinical Usefulness ◽  
The Past ◽  
Analytical Results ◽  
Control Procedures

Abstract We propose a statistical procedure for long-term quality-control of laboratory instruments, including daily, day-to-day, and monthly evaluations. The procedure is based on the unique and unequivocal interpretation of five results for control sera by calculation of a Reliability Index and further manipulations of this unitless parameter. This method, which we have tested during the past two years, allows for monitoring analytical performance and making comparisons with results of interlaboratory surveys. The monthly analytical variability, expressed as "total error," is an indicator of the clinical usefulness of analytical results.

Long-Term Trends in Biochemical Data Obtained from Two Population Surveys

1986 ◽  
Vol 23 (4) ◽  
pp. 474-486 ◽  
Author(s):  
P M G Broughton ◽  
Roger Holder ◽  
Deborah Ashby
Keyword(s):  
Quality Control ◽  
Mean Value ◽  
Population Surveys ◽  
Men And Women ◽  
Mean Values ◽  
Epidemiological Surveys ◽  
Abrupt Changes ◽  
Control Procedures ◽  
Long Term Trends

A study has been made of the variations in monthly mean values of 10 serum constituents in subjects participating in two partly-concurrent long-term epidemiological surveys. Closely similar patterns of variation were found in men in both surveys and in men and women in one survey. During the 6 years of the study, four types of variation of the monthly mean concentrations were identified in varying combinations: (i) abrupt changes of less than 2% not detected by quality control procedures; (ii) a gradual drift in mean value; (iii) haphazard variations in mean values; and (iv) seasonal variations in bilirubin and urea, identical in men and women. The implications of these findings for the design of long-term epidemiological surveys, and the criteria for designating variations as seasonal, are discussed.

Studies and Application of Auger Monitoring System for Quality Control and Assurance of Al Bondpads

2016 ◽  
Author(s):  
Hua Younan
Keyword(s):  
Quality Control ◽  
Sample Preparation ◽  
Monitoring System ◽  
Failure Mechanisms ◽  
Wafer Fabrication ◽  
Contamination Level ◽  
Auger Analysis ◽  
Low Level ◽  
Monitoring Frequency ◽  
Control Procedures

Abstract In wafer fabrication (Fab), Fluorine (F) based gases are used for Al bondpad opening process. Thus, even on a regular Al bondpad, there exists a low level of F contamination. However, the F level has to be controlled at a lower level. If the F level is higher than the control/spec limits, it could cause F-induced corrosion and Al-F defects, resulting in pad discoloration and NSOP problems. In our previous studies [1-5], the theories, characteristics, chemical and physical failure mechanisms and the root causes of the F-induced corrosion and Al-F defects on Al bondpads have been studied. In this paper, we further study F-induced corrosion and propose to establish an Auger monitoring system so as to monitor the F contamination level on Al bondpads in wafer fabrication. Auger monitoring frequency, sample preparation, wafer life, Auger analysis points, control/spec limits and OOC/OOS quality control procedures are also discussed.

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