scholarly journals 5,5-Dialkylluciferins are thermal stable substrates for bioluminescence-based detection systems

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0243747
Author(s):  
Ce Shi ◽  
Michael P. Killoran ◽  
Mary P. Hall ◽  
Paul Otto ◽  
Monika G. Wood ◽  
...  
Keyword(s):  
Thermal Inactivation ◽  
Firefly Luciferase ◽  
Breakdown Product ◽  
Detection Systems ◽  
Oxidative Breakdown ◽  
Luciferase Enzyme ◽  
Cost Efficient ◽  
The Individual ◽  
Detection Reagent ◽  
Atp Detection

Firefly luciferase-based ATP detection assays are frequently used as a sensitive, cost-efficient method for monitoring hygiene in many industrial settings. Solutions of detection reagent, containing a mixture of a substrate and luciferase enzyme that produces photons in the presence of ATP, are relatively unstable and maintain only a limited shelf life even under refrigerated conditions. It is therefore common for the individual performing a hygiene test to manually prepare fresh reagent at the time of monitoring. To simplify sample processing, a liquid detection reagent with improved thermal stability is needed. The engineered firefly luciferase, Ultra-Glo™, fulfills one aspect of this need and has been valuable for hygiene monitoring because of its high resistance to chemical and thermal inactivation. However, solutions containing both Ultra-Glo™ luciferase and its substrate luciferin gradually lose the ability to effectively detect ATP over time. We demonstrate here that dehydroluciferin, a prevalent oxidative breakdown product of luciferin, is a potent inhibitor of Ultra-Glo™ luciferase and that its formation in the detection reagent is responsible for the decreased ability to detect ATP. We subsequently found that dialkylation at the 5-position of luciferin (e.g., 5,5-dimethylluciferin) prevents degradation to dehydroluciferin and improves substrate thermostability in solution. However, since 5,5-dialkylluciferins are poorly utilized by Ultra-Glo™ luciferase as substrates, we used structural optimization of the luciferin dialkyl modification and protein engineering of Ultra-Glo™ to develop a luciferase/luciferin pair that shows improved total reagent stability in solution at ambient temperature. The results of our studies outline a novel luciferase/luciferin system that could serve as foundations for the next generation of bioluminescence ATP detection assays with desirable reagent stability.

scholarly journals A Novel Adaptive Pixels Segmentation Algorithm for Pavement Crack Detection

2021 ◽  
Author(s):  
Nima Safaei ◽  
Omar Smadi ◽  
Babak Safaei ◽  
Arezoo Masoud
Keyword(s):  
Crack Detection ◽  
Low Cost ◽  
Local Level ◽  
Cost Effective ◽  
Segmentation Algorithm ◽  
Pavement Maintenance ◽  
Detection Systems ◽  
Wide Range ◽  
Cost Efficient ◽  
Pavement Crack Detection

<p>Cracks considerably reduce the life span of pavement surfaces. Currently, there is a need for the development of robust automated distress evaluation systems that comprise a low-cost crack detection method for performing fast and cost-effective roadway health monitoring practices. Most of the current methods are costly and have labor-intensive learning processes, so they are not suitable for small local-level projects with limited resources or are only usable for specific pavement types.</p> <p>This paper proposes a new method that uses an improved version of the weighted neighborhood pixels segmentation algorithm to detect cracks in 2-D pavement images. This method uses the Gaussian cumulative density function as the adaptive threshold to overcome the drawback of fixed thresholds in noisy environments. The proposed algorithm was tested on 300 images containing a wide range of noise representative of different noise conditions. This method proved to be time and cost-efficient as it took less than 3.15 seconds per 320 × 480 pixels image for a Xeon (R) 3.70 GHz CPU processor to determine the detection results. This makes the model a perfect choice for county-level pavement maintenance projects requiring cost-effective pavement crack detection systems. The validation results were promising for the detection of low to severe-level cracks (Accuracy = 97.3%, Precision = 79.21%, Recall= 89.18% and F<sub>1</sub> score = 83.9%).</p>

scholarly journals A Fast Method for Predicting the Mechanical Properties of Precipitation-Hardenable Aluminum Alloys

Metals ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 147 ◽  
Author(s):  
Anastasiya Toenjes ◽  
Axel von Hehl
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Aluminum Alloys ◽  
Method Development ◽  
Prediction Models ◽  
Industrial Applications ◽  
Fast Method ◽  
Suitable Heat Treatment ◽  
Cost Efficient ◽  
The Individual

Most heat treatment simulations of precipitation-hardenable aluminum alloys are incomplete or restricted to sub-steps of the process chain. In general, the studies addressing the heat treatment of aluminum components have only provided a qualitative guidance of heat treatment, which does not match the heat treatment that is necessary for specific parts with specific requirements. Thus, a quick and accurate simulation of the whole heat treatment process would hold great economic benefit for industrial applications in predicting suitable heat treatment processes that are able to meet the required mechanical properties of proposed novel aluminum components. In this paper, the development of a time and cost efficient method for generating such prediction models is presented by means of an example aluminum alloy EN AW-6082. During the process sub-steps of solution annealing, quenching and aging, the time-temperature correlations connected to the precipitation-hardening conditions were analyzed. The precision of the prediction model depends on the size of the material database, which should be able to be adjusted to the individual requirements of the simulation user. In order to obtain the greatest time and cost efficiency in generating such a model, a specific experimental design was developed. The results of the method development are presented and discussed.

scholarly journals Development of a Destabilized Firefly Luciferase Enzyme for Measurement of Gene Expression

BioTechniques ◽  
2000 ◽  
Vol 29 (3) ◽  
pp. 590-601 ◽  
Author(s):  
Gilles M. Leclerc ◽  
Fredric R. Boockfor ◽  
William J. Faught ◽  
L. Stephen Frawley
Keyword(s):  
Gene Expression ◽  
Firefly Luciferase ◽  
Luciferase Enzyme

scholarly journals Predictive Thermal Inactivation Model for Effects of Temperature, Sodium Lactate, NaCl, and Sodium Pyrophosphate on Salmonella Serotypes in Ground Beef

2003 ◽  
Vol 69 (9) ◽  
pp. 5138-5156 ◽  
Author(s):  
Vijay K. Juneja ◽  
Harry M. Marks ◽  
Tim Mohr
Keyword(s):  
Heat Resistance ◽  
Survival Data ◽  
Thermal Inactivation ◽  
Ground Beef ◽  
Sodium Lactate ◽  
Sodium Pyrophosphate ◽  
Relative Reduction ◽  
Survival Curves ◽  
The Times ◽  
The Individual

ABSTRACT Analyses of survival data of a mixture of Salmonella spp. at fixed temperatures between 55°C (131°F) and 71.1°C (160°F) in ground beef matrices containing concentrations of salt between 0 and 4.5%, concentrations of sodium pyrophosphate (SPP) between 0 and 0.5%, and concentrations of sodium lactate (NaL) between 0 and 4.5% indicated that heat resistance of Salmonella increases with increasing levels of SPP and salt, except that, for salt, for larger lethalities close to 6.5, the effect of salt was evident only at low temperatures (<64°C). NaL did not seem to affect the heat resistance of Salmonella as much as the effects induced by the other variables studied. An omnibus model for predicting the lethality for given times and temperatures for ground beef matrices within the range studied was developed that reflects the convex survival curves that were observed. However, the standard errors of the predicted lethalities from this models are large, so consequently, a model, specific for predicting the times needed to obtained a lethality of 6.5 log10, was developed, using estimated results of times derived from the individual survival curves. For the latter model, the coefficient of variation (CV) of predicted times range from about 6 to 25%. For example, at 60°C, when increasing the concentration of salt from 0 to 4.5%, and assuming that the concentration of SPP is 0%, the time to reach a 6.5-log10 relative reduction is predicted to increase from 20 min (CV = 11%) to 48 min (CV = 15%), a 2.4 factor (CV = 19%). At 71.1°C (160°F) the model predicts that more than 0.5 min is needed to achieve a 6.5-log10 relative reduction.

NOFO Oil spill response “The way we train”

2017 ◽  
Vol 2017 (1) ◽  
pp. 431-446
Keyword(s):  
Oil Spill ◽  
Large Scale ◽  
Performance Requirement ◽  
Incident Command ◽  
Large Scale Field ◽  
Oil Spill Response ◽  
Cost Efficient ◽  
The Individual ◽  
Different Response ◽  
Norwegian Continental Shelf

ABSTRACT In a situation where oil is spilled on the Norwegian Continental Shelf (NCS) the operator is responsible for the oil spill response. To do this in a robust and efficient way Norwegian Clean Seas Association for Operating Companies (NOFO) handles the oil spill response on behalf of all member companies. Handling an oil spill response situation in all its forms from offshore incident to beach restoration involves many different resources, skills and people. Introducing Incident Command System (ICS) as the command system for this task even increases the amount of training we need to do. How can NOFO achieve the optimal training of our common and shared response resources in a time where focus is on an effective and robust response? Having an overview of the different response needs and response plans NOFO coordinates activity, training and exercises in an efficient way. This is done with the aid of NOFO’s operative plan. The plan describes every resource with a performance requirement and puts it in to a response context. This gives NOFO a foundation to build a response that is structured and cost efficient for our members. Furthermore, this enables NOFO to tailor our training and exercises from the individual responder/resource to the complex large-scale field exercise which involves typically 250–350 people from numerous different operating companies, municipalities, governmental and private responders. This paper will describe how we plan, train and exercise on the NCS in order to be prepared for response in an efficient and robust way.

scholarly journals An enhanced chimeric firefly luciferase-inspired enzyme for ATP detection and bioluminescence reporter and imaging applications

2015 ◽  
Vol 484 ◽  
pp. 148-153 ◽  
Author(s):  
Bruce R. Branchini ◽  
Tara L. Southworth ◽  
Danielle M. Fontaine ◽  
Dawn Kohrt ◽  
Munya Talukder ◽  
...  
Keyword(s):  
Firefly Luciferase ◽  
Atp Detection

scholarly journals The effect of avidin-biotin interactions in detection systems for in situ hybridization.

1992 ◽  
Vol 40 (1) ◽  
pp. 135-141 ◽  
Author(s):  
E J Speel ◽  
B Schutte ◽  
F C Ramaekers ◽  
A H Hopman
Keyword(s):  
In Situ Hybridization ◽  
Network Formation ◽  
Transitional Cell ◽  
Fluorescein Isothiocyanate ◽  
Staining Technique ◽  
Dna Probe ◽  
Detection Systems ◽  
Amplification Method ◽  
The Individual

The effect of avidin-biotin interactions in several detection systems for the non-radioactive in situ hybridization (ISH) technique was studied in a model system using a transitional cell carcinoma line and a biotinylated DNA probe. We performed fluorescence ISH to unravel the individual steps in a sensitive and frequently used amplification method which makes use of the alternating cytochemical detection layers of fluorescein isothiocyanate-conjugated avidin (AvFITC) and biotinylated goat anti-avidin (BioGAA) antibodies to detect the hybridized and biotinylated probe. Our experiments revealed that BioGAA antibodies bind with their antigen binding sites and not with their biotin moieties to avidin molecules that have already interacted with the DNA probe. The probable working mechanism of this amplification method is presented in a model. Furthermore, we used a peroxidase staining technique to compare with each other the sensitivity of several other detection systems in which avidin-biotin interactions play an important role, e.g., the avidin-biotinylated peroxidase complex (ABC) system. The experiments show that avidin molecules can not be efficiently used to interconnect two biotinylated molecular layers, since their introduction leads to firmly closed cytochemical networks. Such a closed network is already formed between the hybridized and biotinylated DNA probe and a first detection layer of avidin molecules, as appears from the finding that biotinylated molecules could hardly be coupled to these avidin molecules in a following detection layer. Therefore, the results presented here provide us with new insight into the molecular basis of cytochemical network formation. This will enable us to choose the proper procedures for increasing the sensitivity of ISH detection systems.

scholarly journals Detect Frauds in Credit Card using Data Mining Techniques

2019 ◽  
Vol 9 (2) ◽  
pp. 4891-4895
Keyword(s):  
Data Mining ◽  
Credit Card ◽  
Nearest Neighbor ◽  
Hidden Markov ◽  
K Nearest Neighbor ◽  
Detection Systems ◽  
Important Concern ◽  
On Line ◽  
Using Data ◽  
The Individual

In today era credit card are extensively used for day to day business as well as other transactions. Ascent within the variety of transactions through master card has junction rectifier to rise in the dishonest activities. In trendy day's fraud is one in every of the most important concern within the monetary loses not solely to the merchants however additionally to the individual purchasers. Data processing had competed a commanding role within the detection of credit card in on-line group action. Our aim is to first of all establish the categories of the fraud secondly, the techniques like K-nearest neighbor, Hidden Markov model, SVM, logistic regression, decision tree and neural network. So fraud detection systems became essential for the banks to attenuate their loses. In this paper we have research about the various detecting techniques to identify and detect the fraud through varied techniques of data mining

scholarly journals Evaluation of Different Pooling Methods to Establish a Multi-Century δ18O Chronology for Paleoclimate Reconstruction

Geosciences ◽  
2019 ◽  
Vol 9 (6) ◽  
pp. 270 ◽  
Author(s):  
Zeynab Foroozan ◽  
Jussi Grießinger ◽  
Kambiz Pourtahmasi ◽  
Achim Bräuning
Keyword(s):  
Stable Isotope ◽  
Tree Rings ◽  
High Frequency ◽  
Signal Amplitude ◽  
Test Material ◽  
Northern Iran ◽  
Individual Tree ◽  
Cost Efficient ◽  
The Individual ◽  
Individual Trees

To develop multi-century stable isotope chronologies from tree rings, pooling techniques are applied to reduce laboratory costs and time. However, pooling of wood samples from different trees may have adverse effects on the signal amplitude in the final isotope chronology. We tested different pooling approaches to identify the method that is most cost-efficient, without compromising the ability of the final chronology to reflect long-term climate variability as well as climatic extreme years. As test material, we used δ18O data from juniper trees (Juniperus polycarpus) from Northern Iran. We compared inter-tree and shifted 5-year blocks serial pooling of stable isotope series from 5 individual trees and addition of one single series to a shifted serial pooled chronology. The inter-tree pooled chronology showed the strongest climate sensitivity and most synchronous δ18O variations with the individual tree ring analyses, while the shifted block chronologies showed a marked decline in high-frequency signals and no correlations with climate variables of the growth year. Combinations of block-pooled and single isotope series compensated the high-frequency decline but added tree-individual climatic signals. Therefore, we recommend pooling calendar synchronous tree rings from individual trees as a viable alternative to individual-tree isotope measurements for robust paleoclimate reconstructions.

scholarly journals Arsenic Monitoring in Water by Colorimetry Using an Optimized Leucomalachite Green Method

Molecules ◽  
2019 ◽  
Vol 24 (2) ◽  
pp. 339 ◽  
Author(s):  
Annija Lace ◽  
David Ryan ◽  
Mark Bowkett ◽  
John Cleary
Keyword(s):  
Detection System ◽  
Colorimetric Method ◽  
In Situ Monitoring ◽  
Detection Systems ◽  
Quantitation Limit ◽  
Arsenic Detection ◽  
Leucomalachite Green ◽  
Colorimetric Reagent ◽  
Cost Efficient ◽  
Colour Development

Arsenic contamination of drinking water is a global concern. Standard laboratory methods that are commonly used for arsenic detection in water, such as atomic absorption spectroscopy and mass spectroscopy, are not suitable for mass monitoring purposes. Autonomous microfluidic detection systems combined with a suitable colorimetric reagent could provide an alternative to standard methods. Moreover, microfluidic detection systems would enable rapid and cost efficient in situ monitoring of water sources without the requirement of laborious sampling. The aim of this study is to optimize a colorimetric method based on leucomalachite green dye for integration into a microfluidic detection system. The colorimetric method is based on the reaction of arsenic (III) with potassium iodate in acid medium to liberate iodine, which oxidizes leucomalachite green to malachite green. A rapid colour development was observed after the addition of the dye. Beer’s law was obeyed in the range between 0.07–3 µg mL−1. The detection limit and quantitation limit were found to be 0.19 and 0.64 µg mL−1, respectively.

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