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The gradual increase in geriatric issues and global imbalance of the ratio between patients and healthcare professionals have created a demand for intelligent systems with the least error-prone diagnosis results to be used by less medically trained persons and save clinical time. This paper aims at investigating the development of image-based colourimetric analysis. The purpose of recognising such tests is to support wider users to begin a colourimetric test to be used at homecare settings, telepathology and so on.

The concept of an automatic colourimetric assay detection is delivered by utilising two cases. Training deep learning (DL) models on thousands of images of these tests using transfer learning, this paper (1) classifies the type of the assay and (2) classifies the colourimetric results.

This paper demonstrated that the assay type can be recognised using DL techniques with 100% accuracy within a fraction of a second. Some of the advantages of the pre-trained model over the calibration-based approach are robustness, readiness and suitability to deploy for similar applications within a shorter period of time.

To the best of the authors’ knowledge, this is the first attempt to provide colourimetric assay type classification (CATC) using DL. Humans are capable to learn thousands of visual classifications in their life. Object recognition may be a trivial task for humans, due to photometric and geometric variabilities along with the high degree of intra-class variabilities, it can be a challenging task for machines. However, transforming visual knowledge into machines, as proposed, can support non-experts to better manage their health and reduce some of the burdens on experts.

The textile sector struggles with cotton stickiness from honeydew contamination. It hurts agriculture and marketability. This study aims to examine how bacterial enzymes could reduce honeydew-contaminated cotton adherence in textile businesses sustainably.

Enzyme was extracted from bacteria isolated from the fermented bamboo shoots “Lung siej”. The enzyme was tested for α-glucosidase using p-nitrophenyl-α-D-glucopyranoside as a substrate. Design of experiments determined enzyme activity temperature and reaction time. Laboratory-prepared artificial honeydew was added to ginning mill cotton to show honeydew contamination. After enzyme treatment, sticky cotton was tested for microscopic examination, ultraviolet (UV), Benedict’s, Elsner colorimetric, high volume instrument (HVI) and viscosity tests.

The bacterial isolate is characterized as Lysinibacillus sp. as confirmed by 16S rRNA gene sequencing. The enzyme extracted was identified as α-glucosidase. The ideal temperature and reaction time for enzymatic activity were 32 °C and 35 min, respectively, using central composite design. The microscopic examination, UV test, Benedict’s test, Elsner colorimetric test, HVI test and viscosity test showed that bacterial enzyme treatment reduced cotton fiber adherence.

Although few patents have examined the effect of yeast enzymes, to the best of the authors’ knowledge, a bacterial enzyme is investigated for the first time to reduce the adhesion of honeydew-contaminated cotton.

To the best of the authors’ knowledge, no study has previously examined the use of psychoactive substances (PASs) at electronic dance music (EDM) events in Ukraine. Addressing this gap in the research literature, this study aims to: describe the recreational drug scene associated with Ukrainian EDM culture; identify clusters of EDM participants who use PAS, based on their drug use patterns; and assess the uptake of drug checking and investigate associations between drug checking and subsequent drug-related behaviour.

A series of cross-sectional surveys were conducted in 2021 (N = 1,307) among EDM festival participants in Ukraine. The authors performed cluster analysis to identify distinct profiles of PAS users. Trends in drug checking were analysed based on cross-sectional surveys conducted at one recurring festival in 2018 (N = 99), 2019 (N = 195) and 2021 (N = 237).

The substances most often used at EDM events were 3,4-Methylenedioxymethamphetamine (37%), amphetamine (16%), lysergic acid diethylamide (11%) and cocaine (9%). Between 2018 and 2021, the proportion of participants who reported to have ever tested their drugs has increased from 2% to 26% (p < 0.001). Unexpected or inconclusive test results led to a significantly lower chances of drug consumption (p = 0.003). The authors identified three distinct clusters of PAS users among the EDM festival attendees in Ukraine.

This study will inform the development of harm reduction interventions tailored to various subgroups of recreational PAS users taking into account gender-specific patterns of use suggested by the authors’ cluster analysis. Increased availability of drug checking is crucial to reduce the risks of drug-related harm associated with the consumption of mis-sold, mislabeled and/or adulterated substances.

The Commission appointed jointly by the World Health Organization and the Food and Agricultural Organization continues to plod its weary way towards the establishment of Codex standards for all foods, which it is hoped will eventually be adopted by all countries, to end the increasing chaos of present national standards. We have to go back to 1953, when the Sixth World Health Assembly showed signs of a stirring of international conscience at trends in food industry; and particularly expressed “the view that the increasing use of various chemical substances had … , created a new public health problem”. Joint WHO/FAO Conferences which followed initiated inter alia international consultations and the setting up of the Joint FAO/WHO Codex Alimentarius Commission.

The purpose of this study was to develop an accurate, selective, low-cost and user-friendly colorimetric pad to detect formaldehyde at low concentration.

1-phenyl-1,3-butanedione, a reactive chemical, was selected to develop the colorimetric pad for indoor air formaldehyde measurement. Silica nanoparticle impregnated with the reactive chemical was coated on the cellulose filter surface to increase the reactive site. A certified formaldehyde permeation tube was used to generate six varied concentrations between 0.01 and 0.10 ppm in a test chamber. The color intensity on the pads was measured using an image processing program to produce a formaldehyde concentration reading chart. The colorimetric pad was tested for optimum reaction time, accuracy, precision, stability, selectivity and shelf life.

The color of the pads changed from white to yellow and the color intensity varied with the concentrations and appeared to be stable after exposure to formaldehyde for 8 hours. At room temperature, the stability of the pad was 7 days, and shelf life was 120 days. The accuracy, precision and bias of the pad were 12.38%, 0.032 and 6.0%, respectively. Carbonyl compounds, benzene and toluene did not interfere with the reading of this developed colorimetric pad.

The developed colorimetric pad meets NIOSH's criteria for an overall accuracy of ±25%, bias = 10%. They were accurate at low concentrations, user-friendly and had low cost compared to an electronic direct reading instrument (cost of chemicals and materials was 21.50 Bath or 0.69 USD per piece) so that favorable for the use of general people for health protection.

The purpose of this paper is to present an automatic inspection and control method for a reagent rapid test strip production system, with image processing techniques.

Fluorescence, color arrangement and combination matching with the database were used to identify the responses of biochemicals. The position accuracy and insufflation consistency between the control line and test line on a reagent rapid test strip will be analyzed from the image after series processing.

The system can identify failed products and regulate production conditions to insure that the quality standard is maintained. The idea edges of the control line and test line are the boundary at which a significant change occurs in the surface reflectance and illumination of the viewer. But the change of the real boundary of the test line may be insufficient for identification.

As the illumination of biological reagent images cannot be measured precisely in the production process, and the intensity of the background light source is difficult to control, there are always significant errors in the production process. If the environment at sampling could be precisely controlled, the accuracy of the system could be enhanced.

This study developed software architecture for a biological reagent production and inspection system. Future studies will focus on the implementation of testing, and improvement of the system, so that it can be applied to medical systems for the benefit of all patients.

Our previous papers (Viková & Vik, 2005) described a unique device, now patented in the Czech Republic in the author's name, for photochromic measurement in a reflectance mode together with a methodology. This device allows photochromic sensors to test the colorimetric and spectral characteristics of photochromic textiles, and also fatigue tests for control of colour change stability. This concept of colorimetric and spectral parameters also finds the dependence of colour change on the intensity of UV irradiation and temperature. In this paper, we would like to describe the dependence of colour change on temperature for the photochromic Photopia AQ Ink system (Blue, Purple and Yellow) produced by Matsui Shikiso Chemical Co.Ltd.

It is known that the reversion of photochromic compounds from coloured to colourless is promoted thermally. The photochromic structure can achieve a lower level of saturated absorbance at higher temperatures when thermo reversible photochromic systems, such as spirooxazines and chromenes, increase the rate of thermal bleaching reaction and thus decrease light stimulated coloration.

The purpose of this paper is to develop a sensitive and cost effective colorimetric sensor for detection of methyl parathion (MP) using simple circuitry. A simple and sensitive concept of colorimetric sensor instrument represents a rapidly expanding field of sensor techniques to monitor MP neurotoxins is described within certain conditions of producing color in samples. The variation of intensity of color with concentration provides discrimination between different concentrations of MP. The colorimetric instrument displays well‐defined signals towards hydrolyzed samples of MP.

The principle of light intensity measurement has been applied to measure various concentrations of MP based on Lambert‐Beer theory. This device and its processes are useful for quantitative analysis of MP. The detection limits were found within a range of 0.1‐1.5 ppm.

The experiments from sophisticated analytical techniques are costly and time‐consuming processes that validate the proposed system.

This paper's original proposition of using quantification of MP with colorimetric sensor instrument obtained promising results.

The colorimetric sensor instrument provides a new method for quantification of MP in unknown samples within detection limits.

This paper aims to describe the techniques used in industrial optical chemical sensors and to consider future prospects.

This paper discusses the techniques and technologies used in today's optical chemical sensors. It highlights their limitations and considers briefly certain new technological developments.

This paper shows that techniques such as wet reagent‐aided photometry, UV absorption, spectroscopy and UV fluorescence satisfy a range of industrial chemical sensing applications and that optode technology is making limited commercial inroads. It identifies the need for inexpensive, wet reagent‐free chemical sensors and suggests that both solid‐state electrodes and lab‐on‐a‐chip devices may ultimately resolve this issue.

This paper provides a technical insight into the state of optical chemical sensing and illustrates that generic families of inexpensive chemical sensors are yet to be developed.

Tungstate inhibitors are seldom used alone in open recirculating cooling water systems due to their low oxidising ability and high cost. The objective of the present work was to develop efficient synergistic inhibitor combinations comprising sodium silicate and very low concentration of sodium tungstate, keeping in view of their application in industrial cooling water system. It was demonstrated in the present study that all the combinations of the inhibitors exhibited synergistic benefit and higher inhibition efficiencies than did either of the individual inhibitors. It was also established that a 4:1 ratio of sodium silicate to sodium tungstate (total 1,000 ppm) was the best overall combination. The FTIR spectra also suggest that tungstate and silicate ions were incorporated in the passivating metal oxide layer formed on the surface of carbon steel in the inhibitor solutions. The effects of excess and depleted concentrations of the individual inhibitor components on overall inhibition behaviour are also discussed.