A FRET Approach to Detect Paraoxon among Organophosphate Pesticides Using a Fluorescent Biosensor

The development of faster, sensitive and real-time methods for detecting organophosphate (OP) pesticides is of utmost priority in the in situ monitoring of these widespread compounds. Research on enzyme-based biosensors is increasing, and a promising candidate as a bioreceptor is the thermostable enzyme esterase-2 from Alicyclobacillus acidocaldarius (EST2), with a lipase-like Ser–His–Asp catalytic triad with a high affinity for OPs. This study aimed to evaluate the applicability of Förster resonance energy transfer (FRET) as a sensitive and reliable method to quantify OPs at environmentally relevant concentrations. For this purpose, the previously developed IAEDANS-labelled EST2-S35C mutant was used, in which tryptophan and IAEDANS fluorophores are the donor and the acceptor, respectively. Fluorometric measurements showed linearity with increased EST2-S35C concentrations. No significant interference was observed in the FRET measurements due to changes in the pH of the medium or the addition of other organic components (glucose, ascorbic acid or yeast extract). Fluorescence quenching due to the presence of paraoxon was observed at concentrations as low as 2 nM, which are considered harmful for the ecosystem. These results pave the way for further experiments encompassing more complex matrices.

Low-cost material as active substrates for the removal of phosphorus in synthetic effluents: a proposal for social treatment technology

Considering the importance of the development of simplified technologies and social control in sanitation actions, this study investigated the use of laterite for phosphorus removal in synthetic effluents, through adsorption, as a low-cost alternative with the possibility of reusing the generated effluent, for communities where access to sanitation is limited. In the experimental design, the variables pH, contact time, granulometry and laterite dosage were used. Factorial planning was used for processing, for optimization and desirability. It was observed that the removal efficiency did not have significant interference in relation to the pH and contact-time variables. The kinetics of the batch experiments showed that the ideal contact time was 6.4 hours and pH of around 4. The adsorption capacity was plotted against equilibrium concentration for the Freundlich and Langmuir isotherms. The Langmuir isotherm was more suitable for phosphorus adsorption. The results show that laterite was effective in phosphorus adsorption in the order of removal of 87%, showing itself to be a potential adsorbent material. Keywords: laterite, phosphate adsorption, simplified effluent treatment.

Development of a Negligible Zero-Drift NDIR Analyzer for Measuring NH3 Emitted from an Urban Household Solid Waste Incinerator

An analyzer for measuring NH3 emitted from a combustion process has been developed based on a simple non-dispersive infrared (NDIR) technique because of its cost-effective benefit. The weakness of the NDIR analyzer due to interference and zero-drift has been overcome. A least-interfering bandpass filter (BPF) was found and manufactured to compensate for the interfering effects of gases emitted from a combustion process (e.g., CO, NOx, SO2, CO2, H2O, HCl, formaldehyde, acetaldehyde and toluene). It was found that there was no significant interference in the least-interfering BPF with respect to gases of concern. Measurement errors by the analyzer were less than 2.5% in a range of 1 to 10 ppmv of NH3 compared to a standard method when the compound was measured in complicated mixing gases. For the zero-drift, using BPFs with identical center wavelength with respect to different incident infrared intensity was found to help minimize the zero-drift of the NDIR analyzer. As a result, the analyzer could cut approximately 19% of zero-drift caused by the aging effect of both IR source and detector. It suggests that the analyzer could be applied for measuring NH3 emitted from combustion processes with good accuracy and reproducibility.

GNSS Interference Environment in Malaysia: A Case Study

Global Navigation Satellite Systems or GNSS is a space technology that has become an essential element nowadays for positioning, navigation & timing (PNT) with wide range of applications in many civilian sectors as well as across military. The reliability, accuracy and availability of GNSS are highly important especially for critical and precise positioning applications. However, the signals from space are weak and it can be easily blocked, disrupted or compromised by several other threats including intentional and unintentional interferences or jamming. GPS jammer is widely available off the shelf with an affordable price and capable of interfering the GPS signal, and many authorities worldwide have raised concerns and a lot of efforts and research have been put in place to reduce and mitigate the threats. In Malaysia, understanding and countering threats to GNSS/GPS based applications will be a new and unfamiliar discipline for public and organizations. This study intended to provide an overview of the GNSS interferences environment in a local study area, in terms of interference type and the number of activity pattern that were detected. A system called Detector V1 has been used in this study. The result showed that significant interference cases happened in the study area and some of the high power interferences may impact GNSS tracking and precision of the positioning output. The role objective of having this done is to create a public awareness regarding the threat of GNSS interferences to the local users. The content also includes the proposed initiative to overcome the issue.

Enhancing sensitivity of QCM for dengue type 1 virus detection using graphene-based polymer composites

Graphene oxide-molecularly imprinted polymer composites (GO-MIP) have attracted significant attention as recognition materials in sensing due to their outstanding properties in terms of electrical and thermal conductivity, high mechanical modulus, and the comparably straightforward way to functionalize them. The aim of this study was to design a MIP-based sensor recognition material and enhance its sensitivity by blending it with GO for sensing a harmful dengue hemorrhagic fever pathogen, namely the dengue type 1 virus (DENV-1). Polymer composites comprising GO incorporated to an acrylamide (AAM)/methacrylic acid (MAA)/methyl methacrylate (MMA)/N-vinylpyrrolidone (VP) copolymer were synthesized and compared to the “pure” MIP, i.e., the copolymer without GO. The pure polymer revealed a zeta potential of + 9.9 ± 0.5 mV, whereas GO sheets prepared have a zeta potential of − 60.3 ± 2.7 mV. This results in an overall zeta potential of − 11.2 ± 0.2 mV of the composite. Such polymer composites seem appropriate to bind the positively charged DENV-1 particle (+ 42.2 ± 2.8 mV). GO-MIP coated onto 10-MHz quartz crystal microbalance (QCM) sensors indeed revealed two times sensitivity compared to sensors based on the pure MIP. Furthermore, GO-polymer composites revealed imprinting factors of up to 21, compared to 3 of the pure MIP. When plotting the sensor characteristic in a semilogarithmic way, the composite sensor shows the linear response to DENV-1 in the concentration range from 100 to 103 pfu mL−1. The corresponding limits of detection (S/N = 3) and quantification (S/N = 10) are 0.58 and 1.94 pfu mL−1, respectively. Furthermore, imprinted polymer composites selectively bind DENV-1 without significant interference: DENV-2, DENV-3, DENV-4, respectively, yield 13–16% of DENV-1 signal. The sensor requires only about 15–20 min to obtain a result. Graphical abstract

THE ELECTROTOMOGRAPHY SURVEY IN DIFFICULT GEOTECHNOGENIC CONDITIONS AT THE PEACEFUL UNDERGROUND NUCLEAR EXPLOSION "CRYSTAL" SITE

The paper presents the results of measurements in 2019 by electrotomography at the site of the emplacement hole of the peaceful underground nuclear explosion "Crystal", carried in 1974 at a depth of 98 m in permafrost Cambrian carbonate rocks, and the neighboring forest area. The fence made of metal poles and barbed wire around the site, and the buried fragments of the casing of the emplacement hole create significant interference of measurements. To avoid the electromagnetic noise, the measured data of the apparent electrical resistivity was cleaned manually. Data inversion was performed in the Res2Dinv program. Geoelectric models, namely two-dimensional sections of the upper part of the geological environment to a depth of up to 80 m, were obtained. To verify the models, forward modeling was performed using the ZondRes2D program.

Vitamin D: Current Challenges between the Laboratory and Clinical Practice

Vitamin D is a micronutrient with pleiotropic effects in humans. Due to sedentary lifestyles and increasing time spent indoors, a growing body of research is revealing that vitamin D deficiency is a global problem. Despite the routine measurement of vitamin D in clinical laboratories and many years of efforts, methods of vitamin D analysis have yet to be standardized and are burdened with significant difficulties. This review summarizes several key analytical and clinical challenges that accompany the current methods for measuring vitamin D. According to an external quality assessment, methods and laboratories still produce a high degree of variability. Structurally similar metabolites are a source of significant interference. Furthermore, there is still no consensus on the normal values of vitamin D in a healthy population. These and other problems discussed herein can be a source of inconsistency in the results of research studies.

Complementary Therapy of Pranic Healing in Managing Moderate Panic Disorder with Mild Agoraphobia during COVID-19 Pandemic: A Case Report

Panic disorder refers to recurrent unexpected panic attacks, including symptoms such as dizziness, chest pain or discomfort, a feeling of unreality, fear of losing control, and fear of dying which could last for few minutes. Here, authors presents a case of 71-year-old male during Coronavirus Disease-2019 (COVID-19) lockdown experienced moderately distressing panic attack symptoms and feared going out by himself, due to the worry of future attacks. These symptoms made significant interference with social activities. The subject was under homeopathic medication and later referred to take Pranic Healing as an add-on therapy. Panic disorder severity (panic disorder severity scale-self report) and severity of agoraphobia (severity measure for agoraphobia-adult) were measured at day 0, day 60 and day 240. Moderate panic disorder (raw score was 12) with mild agoraphobia (raw score was 10) was reduced after 14 pranic healing sessions given in two months duration. No symptoms of agoraphobia or panic disorder were found after six months follow-up. Pranic healing along with homeopathic treatment were found effective in reducing moderate panic disorder with mild agoraphobia. Psychological therapies, combined with medication can be used as gold standards in treating panic disorder.

Influence of DOACs and DOAC Remove® on coagulation assays during thrombophilia testing in DOAC treated patients

Background/Aim. Direct oral anticoagulants (DOACs) administration has a significant interference on coagulation assays. Our study was conducted in order to evaluate the effect of DOACs and DOAC Remove? on coagulation assays during thrombophilia testing. Methods. In the period of January 2019 to the end of June 2020 30 DOAC treated patients tested for thrombophilia, due to venous thromboembolism (VTE), 14 females and 16 males aged 23 to 63 years (median age 47.6 years), were included in the study. Thrombophilia testing was performed using DOAC Remove? tablets (activated charcoal). The results before and after DOAC Remove? were compared. Results. Positive LA results were observed in 20% apixaban, 100% dabigatran, and 70% rivaroxaban treated patient, while in samples after DOAC Remove? the LA positivity was observed only in one from the apixaban group. Before DOAC Remove?, the APC-R ratio was measurable in 40% dabigatran, and 80% rivaroxaban treated patients, while, after using DOAC Remove? the APC-R was measurable in all cases. Comparing the results obtained from the samples before and after DOAC Remove?, a difference was noted in relation to all dRVVT tests, except for the dRVVT ratio in the apixaban group. Clot-based methods for detection of the APC resistance are significantly affected by dabigatran, and less by rivaroxaban. Conclusion. DOAC was practically inactivated after the addition of the DOAC Remove?, which made it possible to perform analyses for the LA and APC-R testing freely and obtain relevant results.

Numerical position optimization of an over-the-wing mounted engine installation

The Collaborative Research Center 880 is investigating different technologies and configurative variants for the purpose of short take-off and landing (STOL) capabilities, ranging from high-lift systems with Coandӑ flaps to unusual but potentially more efficient engine arrangements. The present study focuses on the reference configuration 3 (REF3). This configuration is characterized by an UHBR over-the-wing nacelle (OWN) located above the wing trailing edge. Starting from the wing/body configuration the installation effects of the OWN were investigated. A fully automatized surrogate based optimization was used to evaluate the impact of an engine position variation in vertical and horizontal direction to observe fundamental aerodynamic interactions between wing and OWN in cruise flight conditions. Due to the presence of OWN and pylon, a distinct disturbance on the wing upper surface could be observed leading to significant interference effects. Nevertheless, the overall cruise drag of REF3 could be improved by 37 drag counts or nearly 11% due to the position optimization.