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Brazilian Journal of Biology = Revista... 2023Nanosensors work on the "Nano" scale. "Nano" is a unit of measurement around 10- 9 m. A nanosensor is a device capable of carrying data and information about the...
Nanosensors work on the "Nano" scale. "Nano" is a unit of measurement around 10- 9 m. A nanosensor is a device capable of carrying data and information about the behavior and characteristics of particles at the nanoscale level to the macroscopic level. Nanosensors can be used to detect chemical or mechanical information such as the presence of chemical species and nanoparticles or monitor physical parameters such as temperature on the nanoscale. Nanosensors are emerging as promising tools for applications in agriculture. They offer an enormous upgrade in selectivity, speed, and sensitivity compared to traditional chemical and biological methods. Nanosensors can be used for the determination of microbe and contaminants. With the advancement of science in the world and the advent of electronic equipment and the great changes that have taken place in recent decades, the need to build more accurate, smaller and more capable sensors was felt. Today, high-sensitivity sensors are used that are sensitive to small amounts of gas, heat, or radiation. Increasing the sensitivity, efficiency and accuracy of these sensors requires the discovery of new materials and tools. Nano sensors are nanometer-sized sensors that, due to their small size and nanometer size, have such high accuracy and responsiveness that they react even to the presence of several atoms of a gas. Nano sensors are inherently smaller and more sensitive than other sensors.
Topics: Organic Chemicals; Nanoparticles; Agriculture
PubMed: 37194801
DOI: 10.1590/1519-6984.268893 -
Water Research Jul 2022Semi-quantitative GC-MS and LC-MS measurements of organic chemicals in groundwater and surface waters were used to assess the overall magnitude and contribution of the...
Semi-quantitative GC-MS and LC-MS measurements of organic chemicals in groundwater and surface waters were used to assess the overall magnitude and contribution of the most important substances to calculated mixture hazard. Here we use GC-MS and LC-MS measurements taken from two separate national monitoring programs for groundwater and surface water in England, in combination with chronic species sensitivity distribution (SSD) HC50 values published by Posthuma et al. (2019, Environ. Toxicol. Chem, 38, 905-917) to calculate individual substance hazard quotients and mixture effects using a concentration addition approach. The mixture analysis indicated that, as anticipated, there was an increased hazard from the presence of a cocktail of substances at sites compared to the hazard for any single chemical. The magnitude of the difference between the hazard attributed to the most important chemical and the overall mixture effect, however, was not large. Thus, the most toxic chemical contributed ≥ 20% of the calculated mixture effect in >99% of all measured groundwater and surface water samples. On the basis of this analysis, a 5 fold assessment factor placed on the risk identified for any single chemical would offer a high degree of in cases where implementation of a full mixture analysis was not possible. This finding is consistent with previous work that has assessed chemical mixture effects within field monitoring programs and as such provides essential underpinning for future policy and management decisions on how to effectively and proportionately manage mixture risks.
Topics: Environmental Monitoring; Groundwater; Organic Chemicals; Water; Water Pollutants, Chemical
PubMed: 35635919
DOI: 10.1016/j.watres.2022.118641 -
Molecules (Basel, Switzerland) Feb 2021It is counterintuitive that chemical reactions can be accelerated by freezing, but this amazing phenomenon was discovered as early as the 1960s. In frozen systems, the... (Review)
Review
It is counterintuitive that chemical reactions can be accelerated by freezing, but this amazing phenomenon was discovered as early as the 1960s. In frozen systems, the increase in reaction rate is caused by various mechanisms and the freeze concentration effect is the main reason for the observed acceleration. Some accelerated reactions have great application value in the chemistry synthesis and environmental fields; at the same time, certain reactions accelerated at low temperature during the storage of food, medicine, and biological products should cause concern. The study of reactions accelerated by freezing will overturn common sense and provide a new strategy for researchers in the chemistry field. In this review, we mainly introduce various mechanisms for accelerating reactions induced by freezing and summarize a variety of accelerated cryochemical reactions and their applications.
Topics: Animals; Freezing; Humans; Hydrogen-Ion Concentration; Kinetics; Organic Chemicals; Peptide Fragments; Polymerization; Proteins
PubMed: 33535547
DOI: 10.3390/molecules26030750 -
Environmental Science & Technology Apr 2022Permanently charged and ionizable organic compounds (IOC) are a large and diverse group of compounds belonging to many contaminant classes, including pharmaceuticals,...
Permanently charged and ionizable organic compounds (IOC) are a large and diverse group of compounds belonging to many contaminant classes, including pharmaceuticals, pesticides, industrial chemicals, and natural toxins. Sorption and mobility of IOCs are distinctively different from those of neutral compounds. Due to electrostatic interactions with natural sorbents, existing concepts for describing neutral organic contaminant sorption, and by extension mobility, are inadequate for IOC. Predictive models developed for neutral compounds are based on octanol-water partitioning of compounds () and organic-carbon content of soil/sediment, which is used to normalize sorption measurements (). We revisit those concepts and their translation to IOC ( and ) and discuss compound and soil properties determining sorption of IOC under water saturated conditions. Highlighting possible complementary and/or alternative approaches to better assess IOC mobility, we discuss implications on their regulation and risk assessment. The development of better models for IOC mobility needs consistent and reliable sorption measurements at well-defined chemical conditions in natural porewater, better IOC-, as well as sorbent characterization. Such models should be complemented by monitoring data from the natural environment. The state of knowledge presented here may guide urgently needed future investigations in this field for researchers, engineers, and regulators.
Topics: Adsorption; Carbon; Organic Chemicals; Soil; Soil Pollutants; Water
PubMed: 35353522
DOI: 10.1021/acs.est.2c00570 -
Molecules (Basel, Switzerland) Oct 2020Cross-coupling reactions stand among the most important reactions in chemistry [...].
Cross-coupling reactions stand among the most important reactions in chemistry [...].
Topics: Catalysis; Chemistry, Organic; Ligands; Metals; Organic Chemicals
PubMed: 33019540
DOI: 10.3390/molecules25194500 -
Journal of Molecular Graphics &... Mar 2021Soil Organic Matter (SOM) plays an important role in several biogeochemical processes by directly affecting the microbial activity, soil aggregation, plant growth and...
Soil Organic Matter (SOM) plays an important role in several biogeochemical processes by directly affecting the microbial activity, soil aggregation, plant growth and carbon storage. Despite of its importance, our understanding of its composition and structure is still incomplete. Several experiments using elemental analysis, nuclear magnetic resonance (NMR) and mass spectrometry (MS) shed light on the structure of organic matter. In this context, the Vienna Soil-Organic-Matter Modeler (https://somm.boku.ac.at/) is a website that generates condensed phase computer models of Soil-Organic-Matter (SOM). Most of the data comes from standardized samples by the International Humic Substances Association (IHSS), which uses a specific methodology to extract organic compounds from soil, called humic substances. We have improved the modeler by increasing the pool of elemental units that compose our SOM molecules called building blocks, and also by implementing a genetic algorithm that increases the chemical and geometric diversity of the models. This allowed us to create models using the IHSS data as well as different types of soil. The webserver uses as an input principally the elemental and organic composition and offers input files needed to run molecular dynamic (MD) simulations of solvated and neutralized SOM within the framework of the GROMOS 54A7 forcefield and the GROMOS and GROMACS simulation packages.
Topics: Carbon; Humic Substances; Molecular Dynamics Simulation; Organic Chemicals; Soil
PubMed: 33291027
DOI: 10.1016/j.jmgm.2020.107817 -
Environmental Research Apr 2022Indoor spaces contain several classes of persistent organic chemicals, including per- and polyfluoroalkyl substances (PFAS), polybrominated diphenyl ethers (PBDEs),...
Indoor spaces contain several classes of persistent organic chemicals, including per- and polyfluoroalkyl substances (PFAS), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), and organochlorine pesticides (OCPs). However, concentrations of PFAS and persistent chemical mixtures and their associations with building characteristics on college campuses are understudied. We collected dust from 43 nonresidential spaces on four U.S. college campuses in 2016 and evaluated associations of room characteristics (carpeting, upholstered furniture, and years since last furnished) with dust concentrations of PFAS, PBDEs, PCBs, and OCPs. Nine PFAS, twelve PBDEs, two PCBs, and four OCPs were each detected in at least 75% of the spaces, including several chemicals (e.g., DDT) that have been banned for decades. Concentrations were correlated within and, in some cases, between chemical classes. Wall-to-wall carpeting (compared to rooms without wall-to-wall carpeting) was associated with higher concentrations of six individual PFAS and a mixture of PFAS, and the number of pieces of upholstered furniture was associated with increased concentrations of a mixture of PBDEs. These findings indicate that carpeting and furniture are current sources of PFAS and PBDEs, respectively. Building and finish materials should be carefully selected to avoid exposure to persistent chemicals.
Topics: Dust; Environmental Pollutants; Fluorocarbons; Halogenated Diphenyl Ethers; Humans; Hydrocarbons, Chlorinated; Pesticides; Polychlorinated Biphenyls
PubMed: 34902383
DOI: 10.1016/j.envres.2021.112530 -
Chemical Communications (Cambridge,... Mar 2023We propose novel chemometers - passive equilibrium samplers of, , silicone - as an integrative tool for the assessment of hydrophobic organic compounds in multimedia... (Review)
Review
We propose novel chemometers - passive equilibrium samplers of, , silicone - as an integrative tool for the assessment of hydrophobic organic compounds in multimedia environments. The traditional way of assessing levels of organic pollutants across different environmental compartments is to compare the chemical concentration normalized to the major sorptive phase in two or more media. These sorptive phases for hydrophobic organic compounds differ between compartments, , lipids in biota and organic carbon in sediments. Hence, comparability across media can suffer due to differences in sorptive capacities, but also extraction protocols and bioavailability. Chemometers overcome these drawbacks; they are a common, universal and well-defined polymer reference phase for sampling of a large range of nonpolar organic pollutants in different matrices like biota, sediment and water. When bringing the chemometer into direct contact with the sample, the chemicals partition between the sample and the polymer until thermodynamic equilibrium partitioning is established. At equilibrium, the chemical concentrations in the chemometers can be determined and directly compared between media, , between organisms of different trophic levels or inhabiting different areas, between organs within an organism or between biotic and abiotic compartments, amongst others. Chemometers hence allow expressing the data on a common basis, as the equilibrium partitioning concentrations in the polymer, circumventing normalizations. The approach is based on chemical activity rather than total concentrations, and as such, gives a measure of the "effective concentration" of a compound or a mixture. Furthermore, chemical activity is the main driver for partitioning, biouptake and toxicity. As an additional benefit, the extracts of the chemometers only require limited cleanup efforts, avoiding introduction of a bias between chemicals of different persistence, and can be submitted to both chemical analysis and/or bioanalytical profiling.
Topics: Multimedia; Organic Chemicals; Polymers; Water Pollution, Chemical; Environmental Pollutants
PubMed: 36826793
DOI: 10.1039/d2cc06882f -
Biosensors Jul 2019The microbial fuel cell (MFC) is a promising environmental biotechnology that has been proposed mainly for power production and wastewater treatment. Though small power... (Review)
Review
The microbial fuel cell (MFC) is a promising environmental biotechnology that has been proposed mainly for power production and wastewater treatment. Though small power output constrains its application for directly operating most electrical devices, great progress in its chemical, electrochemical, and microbiological aspects has expanded the applications of MFCs into other areas such as the generation of chemicals (e.g., formate or methane), bioremediation of contaminated soils, water desalination, and biosensors. In recent decades, MFC-based biosensors have drawn increasing attention because of their simplicity and sustainability, with applications ranging from the monitoring of water quality (e.g., biochemical oxygen demand (BOD), toxicants) to the detection of air quality (e.g., carbon monoxide, formaldehyde). In this review, we summarize the status quo of MFC-based biosensors, putting emphasis on BOD and toxicity detection. Furthermore, this review covers other applications of MFC-based biosensors, such as DO and microbial activity. Further, challenges and prospects of MFC-based biosensors are briefly discussed.
Topics: Bioelectric Energy Sources; Biosensing Techniques; Cost-Benefit Analysis; Environmental Monitoring; Metals, Heavy; Organic Chemicals; Oxygen; Sensitivity and Specificity; Water Quality
PubMed: 31340591
DOI: 10.3390/bios9030092 -
Environment International Dec 2022Air pollution is associated with accelerated biological ages determined by DNA methylation (DNAm) patterns, imposing further risks of age-related adverse effects....
BACKGROUND
Air pollution is associated with accelerated biological ages determined by DNA methylation (DNAm) patterns, imposing further risks of age-related adverse effects. However, little is known about the independent and joint effects of exposure to gaseous organic chemicals that may share a common source.
METHODS
We conducted a panel study with the 3-day exposure assessment monthly among 73 Chinese healthy elderly people aged 60 to 69 years in Jinan, Shandong province during September 2018 to January 2019.Exposure to 26 ambient organic chemical contaminants were measured by wearable passive samplers, including volatile organic compounds, polycyclic aromatic hydrocarbons (PAHs), phthalates (PAEs), nitroaromatics (NIs), polybrominated diphenyl ethers, chlorinated hydrocarbons, and organophosphate esters. The Illumina MethylationEPIC BeadChip was used to measure DNA methylation levels in blood samples, and based on which, epigenetic ageing biomarkers, including Hannum clock, Horvath clock, DNAm PhenoAge, DNAm GrimAge, and DNAm estimator of telomere length (DNAmTL) were calculated. Linear mixed effect models were used to estimate the linear associations between 3-day personal chemical exposure and the epigenetic biomarkers, Weighted quantile sum (WQS) regression and the Bayesian kernel machine regression (BKMR) model were further used to evaluate the effect of chemical mixtures.
RESULTS
Multiple linear mixed effects regression models showed that DNAmPhenoAge acceleration was significantly and positively associated with exposure to PAEs, NIs, and PAHs in healthy elderly individuals. Both WQS regression and BKMR models showed a significant positive association with DNAmPhenoAge acceleration with chemical exposures, in which the effect of di-n-butyl phthalate exposure showed the greatest importance.
CONCLUSION
These findings suggest that exposure to a mixture of airborne chemicals significantly increase the acceleration of the epigenetic biomarker of phenotypic age. These findings serve to identify toxic chemicals in the air and facilitate the evaluation of their potentially severe health effects.
Topics: Aged; Humans; Bayes Theorem; East Asian People; Air Pollution; Aging; Epigenomics; Biomarkers; Polycyclic Aromatic Hydrocarbons
PubMed: 36375280
DOI: 10.1016/j.envint.2022.107614