The Performance of Different Analytical Approaches Measuring Respirable Quartz In the Workplace Analysis Scheme for Proficiency (WASP) and the Precision and Limit of Detection of the Direct On-Air-Filter Analysis Methods

It is important to detect thrombin due to its physiological and pathological roles, where rapid and simple analytical approaches are needed. In this study, an aptasensor based on fluorescence attenuation kinetics for the detection of thrombin is presented, which incorporates the features of stilbene and aptamer. We designed and synthesized an aptasensor by one-step coupling of stilbene compound and aptamer, which employed the adaptive binding of the aptamer with thrombin to cause a change in stilbene fluorescence attenuation kinetics. The sensor realized detection of thrombin by monitoring the variation in apparent fluorescence attenuation rate constant (kapp), which could be further used for probing of enzyme–aptamer binding. In comprehensive studies, the developed aptasensor presented satisfactory performance on repeatability, specificity, and regeneration capacity, which realized rapid sensing (10 s) with a limit of detection (LOD) of 0.205 μM. The strategy was successful across seven variants of thrombin aptasensors, with tunable kapp depending on the SITS (4-Acetamido-4′-isothiocyanato-2,2′-stilbenedisulfonic acid disodium salt hydrate) grafting site. Analyte detection mode was demonstrated in diluted serum, requiring no separation or washing steps. The new sensing mode for thrombin detection paves a way for high-throughput kinetic-based sensors for exploiting aptamers targeted at clinically relevant proteins.

Download Full-text

Flood Inundation Assessment Considering Hydrologic Conditions and Functionalities of Hydraulic Facilities

Water ◽

10.3390/w10121879 ◽

2018 ◽

Vol 10 (12) ◽

pp. 1879

Author(s):

Yuan-Heng Wang ◽

Yung-Chia Hsu ◽

Gene You ◽

Ching-Lien Yen ◽

Chi-Ming Wang

Keyword(s):

Risk Analysis ◽

Action Plan ◽

Flood Management ◽

Engineering System ◽

Flood Inundation ◽

Remedial Action ◽

Inundation Area ◽

Analysis Methods ◽

Analysis Scheme ◽

Remedial Action Plan

This study proposed a two-phase risk analysis scheme for flood management considering flood inundation losses, including: (1) simplified qualitative-based risk analysis incorporating the principles of failure mode and effect analysis (FMEA) to identify all potential failure modes associated with candidate flood control measures, to formulate a remedial action plan aiming for mitigating the inundation risk within an engineering system; and (2) detailed quantitative-based risk analysis to employ numerical models to specify the consequences including flood extent and resulting losses. Conventional qualitative-based risk analysis methods have shown to be time-efficient but without quantitative information for decision making. However, quantitative-based risk analysis methods have shown to be time- and cost- consuming for a full spectrum investigation. The proposed scheme takes the advantages of both qualitative-based and quantitative-based approaches of time-efficient, cost-saving, objective and quantitative features for better flood management in term of expected loss. The proposed scheme was applied to evaluate the Chiang-Yuan Drainage system located on Lin-Bien River in southern Taiwan, as a case study. The remedial action plan given by the proposed scheme has shown to greatly reduce the inundation area in both highlands and lowlands. These measures was investigated to reduce the water volume in the inundation area by 0.2 million cubic meters, even in the scenario that the flood recurrence interval exceeded the normal (10-year) design standard. Our results showed that the high downstream water stage in the downstream boundary may increase the inundation area both in downstream and upstream and along the original drainage channel in the vicinity of the diversion. The selected measures given by the proposed scheme have shown to substantially reduce the flood risk and resulting loss, taking account of various scenarios: short duration precipitation, decreased channel conveyance, pump station failure and so forth.

Download Full-text

Accurate determination of meat mass fractions using DNA measurements for quantifying meat adulteration

10.1101/2020.06.14.150375 ◽

2020 ◽

Cited By ~ 2

Author(s):

Sasithon Temisak ◽

Pattanapong Thangsunan ◽

Jiranun Boonil ◽

Watiporn Yenchum ◽

Kanjana Hongthong ◽

...

Keyword(s):

Nuclear Dna ◽

Limit Of Detection ◽

Accurate Determination ◽

Poultry Meat ◽

Quantitative Detection ◽

Limit Of Quantification ◽

Food Fraud ◽

Significant Difference ◽

Mass Fractions ◽

Analytical Approaches

AbstractThe problem in meat adulteration and food fraud emphasised the requirement of developing accurate analytical approaches for the quantitative detection in helping the control of meat adulteration. In this study, the droplet digital Polymerase Chain Reaction (ddPCR) assays to quantify the ratios of pork DNA to the total amount of meat DNA were developed by challenging against DNA extracted from a range of gravimetrically prepared matrices of pork in beef. A single copy nuclear DNA gene, β-actin, was employed as a target gene, accompanied with myostatin gene as a cross species target for mammal and poultry meat background in order to quantifying approach. All the developed assays, singleplex, duplex and triplex did not show significant difference in quantification of pork content in beef background and demonstrated a good and comparable performance to the mass fractions. The singleplex assay provided more biases than the other two assays when performing with a low concentration of target species. The duplex assay provided a simultaneous quantification of pork and myostatin, whereas the triplex assay was able to detect pork, beef and myostatin with a decrease of technical error, cost and running time. All proposed methods allowed us to quantify pork addition in beef with a limit of quantification (LOQ) estimated at 0.1% (w/w) and a limit of detection (LOD) down to 0.01% (w/w). The developed triplex assay was also tested with commercial processed foods and showed the ability to determine not only the presence of particular pork or beef but also the quantitative purpose directly without standard curves. Hence, the developed ddPCR assays demonstrated a good trueness and precision of the methods in quantifying pork or beef content for meat adulteration. It is expected that these developed approaches can be applied to help regulators to confidently enforce food labelling obligations.

Download Full-text