Fluorometric Measurement of Aflatoxin Adsorbed on Florisil in Minicolumns

1975 ◽  
Vol 58 (4) ◽  
pp. 757-763 ◽  
Author(s):  
James Velasco
Keyword(s):  
Fluorescence Intensity ◽  
Aflatoxin B1 ◽  
Coefficient Of Variation ◽  
Screening Procedure ◽  
The Relationship

Abstract Filter fluorometers have been adapted to measure the fluorescence intensity of aflatoxin adsorbed on a Florisil layer in minicolumns. The relationship between concentration and intensity is near linear in the aflatoxin range from 10 to 100 ng. Although individual aflatoxin fractions cannot be resolved, since the measure is one of total intensity, fluorometric measurements advance the minicolumn screening procedure to a semiquantitative level. The detection of 1 ng aflatoxin B1 is well within the limits of a filter fluorometer with a photomultiplier detector. A precision, expressed as percent coefficient of variation, ranging from 1.2 to 4.2%, was obtained for standard B1 columns.

scholarly journals PATTERNS OF CHANGES IN FLUORESCENCE OF NADH AND FAD COENZYMES AND THEIR RELATIONSHIP IN SKELETAL MUSCLE IN EARLY POST-MORTEM PERIOD (EXPERIMENTAL STUDY)

2020 ◽  
Author(s):  
Anastasia S. Babkina
Keyword(s):  
Skeletal Muscle ◽  
Mathematical Models ◽  
Fluorescence Intensity ◽  
Statistical Significance ◽  
Linear Regression Analysis ◽  
Post Mortem ◽  
Redox Ratio ◽  
Measuring Device ◽  
Nadh Fluorescence ◽  
The Relationship

Abstract. The paper presents changes and mathematical models of autofluorescence of reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) and their redox ratio (RR) in the rat skeletal muscle during the first 24 hours after death. Aim. To establish a pattern of change in the fluorescence intensity of NADH and FAD coenzymes, as well as their relationship in the skeletal muscle during the first 24 hours after death using mathematical modeling. Material and methods. The experiment was performed on Sprague Dawley rats. The fluorescence intensity of FAD and NADH coenzymes in skeletal muscle was measured in situ in living rats under general anesthesia, 5 minutes after euthanasia, and at intervals of 1.5-3 h during the 24-hour postmortem period. To estimate the fluorescence intensity of NADH and FAD coenzymes and to calculate the RR, the Lasma MC-3 fluorescence measuring device with special software was used. The obtained data were analyzed by non-linear regression analysis. The summary, accuracy estimation and significance of the regression equation coefficients were assessed using SigmaPlot 10.0 software. The significance of the regression model was tested using the Fisher F-criterion. Results. During the first 3 hours of the postmortem period, an increase in the mean values of RR and NADH fluorescence was detected, starting from 4.5 and till 24 hours post-mortem their gradual decrease was observed. The relationship between NADH, RR and time after death is characterized by the Weibull equation. The statistical significance of NADH and RR models, based on the obtained equations was considered high. Conclusion. The analysis of the obtained data allowed to create mathematical models describing the relationship between RR and NADH fluorescence intensity and time after death, which confirms non-randomness and regularity of the discovered patterns.time of death; NADH; FAD; auto-fluorescence; redox ratio; early post-mortem changes

Application of ELISA to Retail Survey of Aflatoxin B1 in Peanut Butter

1986 ◽  
Vol 49 (10) ◽  
pp. 792-795 ◽  
Author(s):  
BHANU P. RAM ◽  
L. PATRICK HART ◽  
RICHARD J. COLE ◽  
JAMES J. PESTKA
Keyword(s):  
Immunosorbent Assay ◽  
Aflatoxin B1 ◽  
Coefficient Of Variation ◽  
Simple Procedure ◽  
Peanut Butter ◽  
Competitive Elisa ◽  
Routine Screening ◽  
Enzyme Linked Immunosorbent Assay

A simple procedure was devised for the routine screening of aflatoxin B1 (AFB1) in peanut butter using enzyme-linked immunosorbent assay (ELISA). Peanut butter samples (5 g) were artificially contaminated with AFB1 and extracted by blending with 25 ml of 55% methanol and 10 ml of hexane. The extract was filtered and aqueous filtrate analyzed by a direct competitive ELISA. Recovery of AFB1 added to peanut butter samples ranged from 85 to 112%, with an average inter-well coefficient of variation of 18.4%. The inter-assay coefficient of variation was 22.7%. Using this procedure, only 3 of 63 commercial samples of peanut butter had detectable levels (>5.0 μg/kg) of AFB1.

scholarly journals Silver ion-doped CdTe quantum dots as fluorescent probe for Hg2+ detection

RSC Advances ◽  
2020 ◽  
Vol 10 (64) ◽  
pp. 38965-38973
Author(s):  
Huazheng Li ◽  
Wangwei Lu ◽  
Gaoling Zhao ◽  
Bin Song ◽  
Jing Zhou ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Fluorescent Probe ◽  
Fluorescence Intensity ◽  
Silver Ion ◽  
Cdte Quantum Dots ◽  
Detection Range ◽  
Cdte Qds ◽  
Linear Relationships ◽  
The Relationship

Ag-doped CdTe QDs emit multiple-fluorescence peaks, and the relationship between fluorescence intensity and the concentration of Hg2+ is established. Two linear relationships are obtained, which is benefit to the extension of detection range.

Monitoring Training Volume Through Maximal Number of Repetitions or Velocity-Based Approach

2020 ◽  
pp. 1-8
Author(s):  
Miguel Sánchez-Moreno ◽  
Gonçalo Rendeiro-Pinho ◽  
Pedro V. Mil-Homens ◽  
Fernando Pareja-Blanco
Keyword(s):  
Coefficient Of Variation ◽  
Bench Press ◽  
Interindividual Variability ◽  
Load Condition ◽  
Velocity Relationship ◽  
The Mean ◽  
Monitoring Training ◽  
The Individual ◽  
The Relationship ◽  
Level Of Effort

Purpose: This study aimed (1) to analyze the interindividual variability in the maximal number of repetitions (MNR) performed against a given relative load (percentage of 1-repetition maximum [%1RM]) and (2) to examine the relationship between the velocity loss (VL) magnitude and the percentage of completed repetitions with regard to the MNR (%Rep), when the %1RM is based on individual load–velocity relationships. Methods: Following an assessment of 1RM strength and individual load–velocity relationships, 14 resistance-trained men completed 5 MNR tests against loads of 50%, 60%, 70%, 80%, and 90% 1RM in the Smith machine bench-press exercise. The relative loads were determined from the individual load–velocity relationship. Results: Individual relationships between load and velocity displayed coefficients of determination (R2) ranging from .986 to .998. The MNR showed an interindividual coefficient of variation ranging from 8.6% to 33.1%, increasing as the %1RM increased. The relationship between %Rep and the magnitude of VL showed a general R2 of .92 to .94 between 50% and 80% 1RM, which decreased to .80 for 90% 1RM. The mean individual R2 values were between .97 and .99 for all loading conditions. The %Rep when a given percentage of VL was reached showed interindividual coefficient of variation values ranging from 5% to 20%, decreasing as the %Rep increased in each load condition. Conclusions: Setting a number of repetitions had acceptable interindividual variability, with moderate relative loads being adjusted based on the individual load–velocity relationship. However, to provide a more homogeneous level of effort between athletes, the VL approach should be considered, mainly when using individual VL–%Rep relationships.

An increase in habitat complexity reduces aggression and monopolization of food by zebra fish (Danio rerio)

1998 ◽  
Vol 76 (4) ◽  
pp. 770-772 ◽  
Author(s):  
Seán P Basquill ◽  
James WA Grant
Keyword(s):  
Danio Rerio ◽  
Coefficient Of Variation ◽  
Habitat Complexity ◽  
Structural Complexity ◽  
Zebra Fish ◽  
Resource Monopolization ◽  
Dominant Fish ◽  
The Relationship ◽  
Complex Habitat

We tested the predictions that an increase in the structural complexity of a habitat causes both a decrease in aggression and the monopolization of resources. Groups of three zebra fish (Danio rerio) were allowed to compete for food in a complex habitat with simulated vegetation and in a simple habitat with no vegetation. As predicted, both the levels of aggression by the dominant fish (P = 0.050) and the coefficient of variation of the amount of food eaten within a group (P = 0.020), a measure of food monopolization, were lower in the complex habitat than in the simple one. Fish that chased competitors more frequently ate more food in both habitats, but the relationship was stronger in the simple than in the complex habitat. Our results suggest that aggression is less useful as a mode of competition in habitats with greater structural complexity. Manipulating the structural complexity of the habitat may be a practical way of controlling the intensity of aggression and resource monopolization in groups of animals.

The allometric relationship between carcass muscle and carcass bone in Scottish Blackface sheep

1967 ◽  
Vol 9 (4) ◽  
pp. 531-533 ◽  
Author(s):  
T. H. Jackson
Keyword(s):  
Coefficient Of Variation ◽  
Allometric Relationship ◽  
Natural Development ◽  
Relationship Of ◽  
The Relationship

Thirty-seven Blackface wether sheep, ranging from birth to eighteen months of age, were used to derive the allometric relationship between carcass muscle and carcass bone.The equationlog10 muscle (g) = 1·36 log10 bone (g)—0·804fitted the data well. (r = 0·995, b = 1·36±0·05, Sy.x = 0·0595.)The deviations from this equation had a coefficient of variation of 14% indicating that other factors may influence the relationship of muscle to bone.It is suggested that the variablelog10M—1·36 log10 5 + 0·804is independent of differences due to different stages of natural development and can be used to examine the effects of different treatments on the muscle: bone ratio. The constant applies to sheep only.

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