Emerging viruses are a major public health problem. Most zoonotic pathogens originate in wildlife, including human immunodeficiency virus (HIV), influenza, Ebola, and coronavirus. Severe acute ...respiratory syndrome (SARS) is a viral respiratory illness caused by a coronavirus called SARS-associated coronavirus (SARS-CoV). Viruses are charged colloidal particles that have the ability to adsorb on surfaces depending on pH. Their sorptive interaction with solid particles has important implications for their behavior in aquatic environments, soils, sewage sludge, and other solid materials and their removal or concentration by water treatment processes.
Current state of knowledge on the potential of wastewater surveillance to understand the COVID-19 pandemic is reviewed. This study also identified wastewater irrigation systems with a higher risk of COVID-19 transmission. Emphasis was placed on methodologies for the detection and quantification of SARS-CoV-2 in wastewater.
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•Evidence for the presence of COVID-19 in wastewater•Detection methods and prevalence of viruses in wastewater•Knowledge needs for public health.•Recommendations on research and investigation priorities
Context. Open clusters (OCs) are popular tracers of the structure and evolutionary history of the Galactic disc. The OC population is often considered to be complete within 1.8 kpc of the Sun. The ...recent Gaia Data Release 2 (DR2) allows the latter claim to be challenged. Aims. We perform a systematic search for new OCs in the direction of Perseus using precise and accurate astrometry from Gaia DR2. Methods. We implemented a coarse-to-fine search method. First, we exploited spatial proximity using a fast density-aware partitioning of the sky via a k-d tree in the spatial domain of Galactic coordinates, (l, b). Secondly, we employed a Gaussian mixture model in the proper motion space to tag fields quickly around OC candidates. Thirdly, we applied an unsupervised membership assignment method, UPMASK, to scrutinise the candidates. We visually inspected colour-magnitude diagrams to validate the detected objects. Finally, we performed a diagnostic to quantify the significance of each identified over-density in proper motion and in parallax space. Results. We report the discovery of 41 new stellar clusters. This represents an increment of at least 20% of the previously known OC population in this volume of the Milky Way. We also report on the clear identification of NGC 886, an object previously considered an asterism. This study challenges the previous claim of a near-complete sample of OCs up to 1.8 kpc. Our results reveal that this claim requires revision, and a complete census of nearby OCs is yet to be found.
•Methods of green synthesis of (NPs) using plant extract were reviewed.•Properties and characterization techniques of nanoparticles were presented.•Shape and size of green synthesized (NPs) via each ...plant have been compared.•Different utilizations of green synthesized (NPs) were inspected.•Future viewpoint of utilizations of green synthesis of (NPs) was studied.
The Nano-biotechnology represents the intersection of nanotechnology and biotechnology and is a promising field of nanotechnology. Recently, the need of making biocompatible nanoparticles for different applications in various areas by eco-friendly technologies in materials science became significant. Today, green synthesis of different nanoparticles NPs has been broadly examined. Biological synthesis of nanoparticles has evolved as a promising substitute to traditional synthesis methods for producing nanoparticles using unicellular and multicellular biological entities such as actinomycetes yeast, bacteria, viruses, plants, and fungus. In this paper, we provide a general overview on properties, synthesis methods and applications of nanoparticles NPs prepared from plant extract. Indeed, different techniques of green synthesis of NPs by plant extract were discussed and presented. The properties of synthesized NPs, in particular shape and size, were discussed and their applications have been also investigated. Furthermore, the future perspective of green synthesis of NPs and their applications were expressed.
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The cosmological utility of galaxy cluster catalogues is primarily limited by our ability to calibrate the relation between halo mass and observable mass proxies such as cluster richness, X-ray ...luminosity or the Sunyaev-Zeldovich signal. Projection effects are a particularly pernicious systematic effect that can impact observable mass proxies; structure along the line of sight can both bias and increase the scatter of the observable mass proxies used in cluster abundance studies. In this work, we develop an empirical method to characterize the impact of projection effects on redMaPPer cluster catalogues. We use numerical simulations to validate our method and illustrate its robustness. We demonstrate that modeling of projection effects is a necessary component for cluster abundance studies capable of reaching $\approx 5\%$ mass calibration uncertainties (e.g. the Dark Energy Survey Year 1 sample). Specifically, ignoring the impact of projection effects in the observable--mass relation --- i.e. marginalizing over a log-normal model only --- biases the posterior of the cluster normalization condition $S_8 \equiv \sigma_8 (\Omega_{\rm m}/0.3)^{1/2}$ by $\Delta S_8 =0.05$, more than twice the uncertainty in the posterior for such an analysis.
ABSTRACT
We implement the first blind analysis of cluster abundance data to derive cosmological constraints from the abundance and weak lensing signal of redMaPPer clusters in the Sloan Digital Sky ...Survey (SDSS). We simultaneously fit for cosmological parameters and the richness–mass relation of the clusters. For a flat Λ cold dark matter cosmological model with massive neutrinos, we find $S_8 \equiv \sigma _{8}(\Omega _\mathrm{ m}/0.3)^{0.5}=0.79^{+0.05}_{-0.04}$. This value is both consistent and competitive with that derived from cluster catalogues selected in different wavelengths. Our result is also consistent with the combined probes analyses by the Dark Energy Survey (DES), the Kilo-Degree Survey (KiDS), and with the cosmic microwave background (CMB) anisotropies as measured by Planck. We demonstrate that the cosmological posteriors are robust against variation of the richness–mass relation model and to systematics associated with the calibration of the selection function. In combination with baryon acoustic oscillation data and big bang nucleosynthesis data (Cooke et al.), we constrain the Hubble rate to be h = 0.66 ± 0.02, independent of the CMB. Future work aimed at improving our understanding of the scatter of the richness–mass relation has the potential to significantly improve the precision of our cosmological posteriors. The methods described in this work were developed for use in the forthcoming analysis of cluster abundances in the DES. Our SDSS analysis constitutes the first part of a staged-unblinding analysis of the full DES data set.
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•Electrochemical detection of amoxicillin (AMX)•Types of chemically modified electrodes for AMX detection.•Indirect electrochemical methods for AMX analysis.•Analysis of Amoxicilin in ...several real samples.
Amoxicillin (AMX) is among the most successful antibiotics used for human therapy. It is used extensively to prevent or treat bacterial infections in humans and animals. However, the widespread distribution and excess utilization of AMX can be an environmental and health risk due to the hazardous potential associated to its pharmaceutical industries effluents. Besides, their extensive use in food animal production may result in some undesirable residues in food, e.g. meat, eggs and milk. Consequently, at high enough concentrations in biological fluids, AMX may be responsible of various diseases such as nausea, vomiting, rashes, and antibiotic-associated colitis. For this reason, the detection and quantification of amoxicillin in pharmaceuticals, biological fluids, environmental samples and foodstuffs require new electroanalytical techniques with sensitive and rapid measurement abilities. This review discusses recent advances in the development of electrochemical sensors and bio-sensors for AMX analysis in complex matrices such as pharmaceuticals, biological fluids, environmental water and foodstuffs. The main electrochemical sensors used are based on chemically modified electrodes involving carbon materials and nanomaterials, nanoparticles, polymers and biological recognition molecules.
The purpose of this paper is to fabricate graphene oxide (GO) from carbon rods of spent (ZnC) batteries using a new optimized approach in electrochemical applications. The proposed method-based ...sonication for the recycling of carbon rods was adopted as a fast and economical process via a less aggressive pathway. The energy reaction time and explosion problems were avoided by the proposed protocol. The waste graphite powder (carbon rods) and the powder produced by the developed method-based sonication (SGO) were characterized by UV–Visible, XRD, FTIR and SEM. The electrochemical performance of the prepared SGO was evaluated by cyclic voltammetry (CV) and current-voltage (I–V) techniques. The results revealed that SGO has a higher electrocatalytic property compared to the graphene oxide by the standard Hummers method (HGO).
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∙Sonication-assisted oxidation and exfoliation process was recycled for graphene oxide (SGO) production.∙The carbon powder of (ZnC) batteries rods and its graphene oxide (SGO) were characterized.∙The energy and reaction time along with explosion problems were avoided by the proposed approach.∙Electrochemical performances of SGO were investigated and compared to the Hummers graphene oxide (HGO).
•COVID-19 infection poses a serious risk to human life by causing acute lung damage.•Various techniques used to identify and quantify COVID-19 infection.•Major challenges for containing the spread of ...COVID-19 is the ability to identify asymptomatic cases.•Currently available diagnostic methods, biosensing technology developed during COVID-19 infection.
The technologies used for coronavirus testing consist of a pre-existing device developed to examine different pathologies, such as bacterial infections, or cancer biomarkers. However, for the 2019 pandemic, researchers knew that their technology could be modified to detect a low viral load at an early stage. Today, countries around the world are working to control the new coronavirus disease (n-SARS-CoV-2). From this perspective, laboratories, universities, and companies around the world have embarked on a race to develop and produce much-needed test kits. This review has been developed to provide an overview of current trends and strategies in n-SARS-CoV-2 diagnostics based on traditional and new emerging assessment technologies, to continuous innovation. It focuses on recent trends in biosensors to build a fast, reliable, more sensitive, accessible, user-friendly system and easily adaptable technology n-SARS-CoV-2 detection and monitoring. On the whole, we have addressed and identified research evidence supporting the use of biosensors on the premise that screening people for n-SARS-CoV-2 is the best way to contain its spread.
The widespread use of antibiotics has contributed to the control of disease and the nutritional well-being of livestock. Antibiotics reach the environment via excretions (urine and feces) from human ...and domestic animals, through non proper disposal or handling of unused drugs. The present study describes a green method for the synthesis of silver nanoparticle (AgNPs) using cellulose extracted from Phoenix dactylifera seed powder via mechanical stirrer method for the electroanalytical determination of ornidazole (ODZ) in milk and water samples. The cellulose extract is used as the reducing and stabilizer agent for the synthesis of AgNPs. The obtained AgNPs were characterized by UV–Vis, SEM and EDX, presenting a spherical shape and an average size of 48.6 nm. The electrochemical sensor (AgNPs/CPE) was fabricated by dipping a carbon paste electrode (CPE) in the AgNPs colloidal solution. The sensor shows acceptable linearity with ODZ concentration in the linear range from 1.0 × 10−5 to 1.0 × 10−3 M with a limit of detection (LOD =3S/P) and quantification (LOQ =10S/P) of 7.58 × 10−7 M and 2.08 × 10−6 M respectively.
•Extraction of cellulose from Phoenix dactylifera seed and their characterization.•Utilization of the extracted cellulose in the synthesis of silver nanoparticles (AgNPs).•Preparation of new sensor based on synthesized AgNPs, to evaluate the electrocatalytic behavior of ODZ.•Electrochemical detection of ODZ in commercial milk and water samples using the proposed method.
In this study, a material comprised of chitosan stabilized silver nanoparticles on the carbon paste electrode (CS-SNPs/CPE) is used as an electrochemically active material for the determination of ...p-nitroaniline (p-NA) in neutral medium by differential pulse voltammetry (DPV). A chemical process is used to synthesize silver nanoparticles using chitosan and sodium borohydride as stabilizer and reducing agent respectively at room temperature. Characterization of the end product using UV–Vis spectroscopy verified the presence of silver nanoparticles. The silver nanoparticles were shown to have an average size of 50nm by X-ray diffraction analysis. The electrochemical characterization showed that the CS-SNPs/CPE exhibits high electroanalytic activity that can be harnessed for sensor construction and related applications. The as developed sensor exhibited a lower detection limit of 5nM towards the p-NA reduction in the linear range of 7nM to 1μM (R2=0.986). The CS-SNPs/CPE was then extended for the determination of p-NA in real samples such as wastewater. All these studies confirmed that the chitosan stabilized silver nanoparticles on the carbon paste electrode are a potential candidate in the field of electrochemical sensing.
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•The synthesis of CS-Ag nanoparticles was carried out using chemical method.•The proposed electrochemical sensor was reported for p-NA detection using DPV method.•The outstanding analytical performance was demonstrated in detecting p-NA in water.•The constructed sensor holds low detection limit of p-NA under optimized conditions.
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