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1.
Food Chem ; 366: 130634, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34332422

RESUMO

Deep eutectic solvents based on choline chloride, carboxylic acids, urea, and polyols were investigated for separation of 14 metals from plant samples. It was found that carboxylic acid as precursor of DES played key-role for effective metals separation. It was established that the solvent synthesized from choline chloride and malic acid provided highest extraction recovery (from 73 to 88%). Mixing and heating the solvent and sample for 30 min at a temperature of 70 °C provided effective separation of metals from plant sample. The developed procedure is not required a microwave digestion of samples. After separation the solvent phase containing analytes was dissolved in aqueous phase and analyzed. The developed procedure was applied to elemental analysis of plant tobacco and lettuce samples by inductively coupled plasma optical emission spectroscopy. Limits of detection calculated as three times the signal-to-noise ratio were in the range from 0.2 to 17 mg kg-1.


Assuntos
Ácidos Carboxílicos , Metais , Plantas , Solventes , Água
2.
Food Chem ; 368: 130499, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-34496333

RESUMO

Here, we present the potential analytical applications of photochemistry in combination with fluorescence fingerprinting. Our approach analyzes the fluorescence of samples after ultraviolet light (UV) treatment. Especially in presence of metal ions and thiol-containing compounds, the fluorescence behavior changes considerably. The UV-induced reactions (changes) are unique to a given sample composition, resulting in distinct patterns or fingerprints (typically in the 230-600 nm spectral region). This method works without the need for additional chemicals or fluorescent probes, only suitable diluent must be used. The proposed method (UV fingerprinting) suggests the option of recognizing various types of pharmaceuticals, beverages (juices and wines), and other samples within only a few minutes. In some studied samples (e.g. pharmaceuticals), significant changes in fluorescence characteristics (mainly fluorescence intensity) were observed. We believe that the fingerprinting technique can provide an innovative solution for analytical detection.


Assuntos
Corantes Fluorescentes , Raios Ultravioleta , Íons , Metais , Análise Espectral
3.
Environ Monit Assess ; 193(10): 683, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-34596775

RESUMO

The Coeur d'Alene Lake basin in Northwestern USA has extensive contamination from legacy mining waste, which overlaps with aquatic macrophyte habitat. We examined concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in three macrophytes: Elodea canadensis (submerged), Myriophyllum spicatum (submerged), and Sagittaria latifolia (emergent). We collected macrophyte tissues from five contaminated sites and one uncontaminated site. Tissue concentrations were compared to sediment quality guidelines to assess potential toxicity from metal(loid)s to macrophyte-associated biota. We used threshold and probable effect concentrations to screen for potential toxicity. For the submerged species, the highest site means ± SD (analyte mg/kg dry mass) were 96 ± 61 (As), 18 ± 1.7 (Cd), 24 ± 15 (Cu), 610 ± 392 (Pb), and 1425 ± 222 (Zn). For contaminated sites, the probable effect threshold was exceeded in 38% (As), 45% (Cd), 0% (Cu), 74% (Pb), and 67% (Zn) of submerged species concentrations. Metal concentrations in S. latifolia tubers were lower than the submerged species leaves and shoots. Tuber concentrations did not exceed the probable effect threshold for any metal. Spatial differences in concentrations were most distinct for the submerged species. Our work shows significant amounts of metals are accumulating in some macrophytes of the study area and that biota associated with this vegetation may experience toxicity based upon guideline exceedances. Additionally, managers of invasive plants (e.g., M. spicatum) should consider the ramifications of control efforts given the high metal content of some plants (e.g., disposal issue).


Assuntos
Metais Pesados , Poluentes Químicos da Água , Monitoramento Ambiental , Sedimentos Geológicos , Lagos , Metais , Metais Pesados/análise , Poluentes Químicos da Água/análise
4.
Sensors (Basel) ; 21(19)2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34640647

RESUMO

Metamaterial is becoming increasingly important owing to its unique physical properties and breakthrough applications. So far, most metamaterials that have been developed are made of rigid materials and structures, which may restrict their practical adaptation performances. Recently, with the further development of liquid metal, some efforts have explored metamaterials based on such tunable electronic inks. Liquid metal has high flexibility and good electrical conductivity, which provides more possibilities for transformable metamaterials. Here, we developed a new flexible liquid-metal metamaterial that is highly reconfigurable and could significantly extend the working limit facing current devices. The printed electronics method was adopted to fabricate artificial units and then construct various potential transformable metamaterials. Based on metamaterial theory and printing technology, typical structured flexible liquid-metal electromagnetic metamaterials were designed and fabricated. The electronic and magnetic characteristics of the liquid-metal-based electromagnetic metamaterials were evaluated through simulated analysis and experimental measurement. Particularly, the potential of liquid-metal metamaterials in biomedical sensing was investigated. Further, the future outlook of liquid-metal metamaterials and their application in diverse categories were prospected.


Assuntos
Eletrônica , Metais , Condutividade Elétrica
5.
Anal Chim Acta ; 1183: 338987, 2021 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-34627511

RESUMO

The goal of the study was to evaluate the possibilities offered by a new generation of metal-free SEC column to perform direct SEC-MS of protein biopharmaceuticals using ammonium acetate as the main mobile phase additive. The prototype metal-free SEC column hardware used in this work was a polyether ether ketone (PEEK) infused stainless steel tube including PEEK frits. This PEEK-lined column provides a fully bioinert and metal-free fluidic path, while maintaining the stability of the metal hardware, and could be a good solution to limit possible undesired interactions between proteins and column wall/frits. This prototype metal-free SEC column was systematically compared with a conventional stainless-steel SEC column hardware packed with the same stationary phase material. Four different mAb products, namely trastuzumab, palivizumab, bevacizumab and NISTmAb, and one antibody drug conjugate (ADC), trastuzumab emtansine, were selected as test samples. It appears that peak symmetry, separation of low molecular weight species (LMWS), and the recovery of high molecular weight species (HMWS) were significantly improved for the different biopharmaceutical products on the metal-free SEC column. It has also been demonstrated that the largest differences between standard and metal-free SEC columns were observed for the most basic mAbs (high pI), which confirms that electrostatic interactions between the mAb and the metallic parts of the column (frits and inlet tube) could be responsible for the issues observed when performing SEC analysis with volatile mobile phase. Finally, it was feasible to perform SEC-MS analysis for a wide range of biopharmaceutical products using volatile mobile phase. Our results also highlight that an inappropriate column could bias the quantification of size variants when using MS-compatible mobile phases. Therefore, metal-free column, such as the PEEK-lined column, should be preferentially selected for SEC-MS analysis.


Assuntos
Imunoconjugados , Metais , Anticorpos Monoclonais , Cromatografia em Gel , Espectrometria de Massas
6.
Georgian Med News ; (318): 139-142, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34628395

RESUMO

Structural organization of serum albumins - the most abundant globular proteins in serum plasma - gives rise to their extraordinary binding and functional capacity. Various classes of ligands, including the metal ions can be captured and transported by albumins. Metal binding to human serum albumin, HSA, that is an essential multipurpose target for the modern biomedicine, to its bovine equivalent, BSA, and other mammalian analogs have been extensively explored in the context of metabolism of essential metal ions, like Cu2+. Taking into account structural similarity of human and bovine serum albumins, the later was selected as a relevant model in laboratory studies due to its low cost and wide availability. In the present work metal binding properties of BSA with copper ions (Cu2+) were explored using combined voltammetric and thermodynamic examinations. According to voltammetric data, addition of equal amount of BSA (1.8x10-3)M to the solution (0.2 M KCl) containing (1.8x 10-3) M CuCl2 results that two pairs of redox peaks belonging to the Cu2+ /Cu+ (E0 = 0,16 V) and Cu+/Cu0 (E0 = -0.2 V) electronic transformations disappear and a new weak single reductive peak, at Epk=-0,55V attributable to the Cu2+/Cu+ transition is shown. BSA- Cu2+ complex formation is presumably responsible for this dramatic shift of Cu2+ reduction process to much more negative potential. The chelating environment of "N-terminal" sequence of: Asp-Thr-His- of BSA, assisted by direct participation of the sulfuric group of a Cys-34 residue, is presumably responsible for the entrapment and "locking" the copper ion, in an "abnormal", redox inactive condition (showing virtually no voltammetric activity). Our DSC data confirmed the complex formation process in the solutions containing the equal (1.8x10-3) M concentrations of both, BSA and CuCl2 and clearly shows small but distinct conformational stabilization with respect of two thermodynamic parameters, the melting temperature and melting enthalpy.


Assuntos
Cobre , Albumina Sérica , Animais , Bovinos , Humanos , Metais , Soroalbumina Bovina , Termodinâmica
7.
Science ; 374(6564): 148-150, 2021 10 08.
Artigo em Inglês | MEDLINE | ID: mdl-34618570

RESUMO

[Figure: see text].


Assuntos
Metais , Fenômenos Físicos
8.
J Environ Sci (China) ; 108: 33-43, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34465435

RESUMO

To achieve "waste controlled by waste", a novel wet process using KMnO4/copper converter slag slurry for simultaneously removing SO2 and NOx from acid-making tail gas was proposed. Through the solid-liquid separation for copper slag slurry, the liquid-phase part has a critical influence on removing NOx and SO2. Also, the leached metal ions played a crucial role in the absorption of SO2 and NOx. Subsequently, the effects of single/multi-metal ions on NOx removal was investigated. The results showed that the leached metal from copper converter slag (Al3+, Cu2+, and Mg2+) and KMnO4 had a synergistic effect on NOx removal, thereby improving the NOx removal efficiency. Whereas Fe2+ had an inhibitory effect on the NOx removal owing to the reaction between Fe2+ and KMnO4, thereby consuming the KMnO4. Besides, SO2 was converted to SO42- completely partly due to the liquid catalytic oxidation by metal ions. The XRD and XPS results indicated that the Fe (II) species (Fe2SiO4, Fe3O4) in copper slag can react with H+ ions with the generation of Fe2+, and further consumed the KMnO4, thereby resulting in a decrease in the NOx removal. The characterization of the slags and solutions before and after reaction led us to propose the possible mechanisms. The role of copper slag is as follows: (1) the alkaline substances in copper slag can absorb SO2 and NO2 by KMnO4 oxidation. (2) copper slag may function as a catalyst to accelerate SO2 conversion and improve NOx removal by synergistic effect between leached metal ions and KMnO4.


Assuntos
Cobre , Dióxido de Enxofre , Metais , Oxirredução
9.
Chemosphere ; 282: 131051, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470148

RESUMO

Marine tailing disposal (MTD) is sometimes practiced as an alternative to traditional mine tailing deposition on land. Environmental challenges connected to MTD include spreading of fine particulate matter in the water column and the potential release of metals and processing chemicals. This study investigated if tailing exposure affects the marine copepod Calanus finmarchicus, and whether effects are related to exposure to mineral particles or the presence of metals and/or processing chemicals in the tailings. We investigated the impacts of three different tailing compositions: calcium carbonate particles with and without processing chemicals and fine-grained tailings from a copper ore. Early life stages of C. finmarchicus were exposed over several developmental stages to low and high suspension concentrations for 15 days, and their development, oxygen consumption and biometry determined. The data was fitted in a dynamic energy budget (DEB) model to determine mechanisms underlying responses and to understand the primary modes of action related to mine tailing exposure. Results show that copepods exposed to tailings generally exhibited slower growth and accumulated less lipids. The presence of metals and processing chemicals did not influence these responses, suggesting that uptake of mineral particles was responsible for the observed effects. This was further supported by the applied DEB model, confirming that ingestion of tailing particles while feeding can result in less energy being available for growth and development.


Assuntos
Copépodes , Animais , Carbonato de Cálcio , Cobre/toxicidade , Metais , Material Particulado
10.
Chemosphere ; 282: 131150, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34470175

RESUMO

Epidemiologic studies focus on combined effects of multiple metals on bone mineral density (BMD) are scarce. Therefore, this study was conducted to examine associations of multiple metals exposure with BMD. Data of adults aged ≥20 years (n = 2545) from the US National Health and Nutrition Examination Survey (NHANES, 2011-2016) were collected and analyzed. Concentrations of metals were measured in blood (cadmium [Cd], lead [Pb], mercury [Hg], and manganese [Mn]) and serum (copper [Cu], selenium [Se], and zinc [Zn]) using inductively coupled plasma mass spectrometry and inductively coupled plasma dynamic reaction cell mass spectrometry, respectively. The weighted quantile sum (WQS) and Bayesian kernel machine regression (BKMR) models were performed to determine the joint effects of multiple metals exposure on lumbar and total BMD. The linear regression analyses showed Pb was negatively associated with BMDs. The WQS regression analyses revealed that the WQS index was inversely related to lumbar (ß = -0.022, 95% CI: -0.036, -0.008) and total BMD (ß = -0.015, 95% CI: -0.024, -0.006), and Se, Mn, and Pb were the main contributors for the combined effects. Additionally, nonlinear dose-response relationships between Pb, Mn, and Se and BMD, as well as a synergistic interaction of Pb and Mn, were found in the BKMR analyses. Our findings suggested co-exposure to Cd, Pb, Hg, Mn, Cu, Se, and Zn (above their 50th percentiles) was associated with reduced BMD, and Pb, Mn, and Se were the main contributors driving the overall effects.


Assuntos
Densidade Óssea , Metais , Teorema de Bayes , Cádmio , Inquéritos Nutricionais
11.
Talanta ; 235: 122725, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517593

RESUMO

Analysis of the spatial distribution of metals, metalloids, and non-metals in biological tissues is of significant interest in the life sciences, helping to illuminate the function and roles these elements play within various biological pathways. Chemical imaging methods are commonly employed to address biological questions and reveal individual spatial distributions of analytes of interest. Elucidation of these spatial distributions can help determine key elemental and molecular information within the respective biological specimens. However, traditionally utilized imaging methods prove challenging for certain biological tissue analysis, especially with respect to applications that require high spatial resolution or depth profiling. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been shown to be effective for direct elemental analysis of solid materials with high levels of precision. In this work, chemical imaging using LA-ICP-MS has been applied as a powerful analytical methodology for the analysis of liver tissue samples. The proposed analytical methodology successfully produced both qualitative and quantitative information regarding specific elemental distributions within images of thin tissue sections with high levels of sensitivity and spatial resolution. The spatial resolution of the analytical methodology was innovatively enhanced, helping to broaden applicability of this technique to applications requiring significantly high spatial resolutions. This information can be used to further understand the role these elements play within biological systems and impacts dysregulation may have.


Assuntos
Terapia a Laser , Fígado , Espectrometria de Massas , Metais , Análise Espectral
12.
Talanta ; 235: 122745, 2021 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-34517613

RESUMO

Gas sensors have aroused much attention in recent years for the important effect in modern society. Graphene, with unique structure and characteristic properties, has been considered as a promising candidate for fabricating high-performance gas sensor. Great efforts in current research are directed towards exploiting various graphene-based gas sensors, but the core of gas sensing study is how to enhance the gas sensing performance. Herein, we propose a perspective that focuses on the strategies for sensing performance enhancement of graphene-based gas sensors. Several strategies are reviewed such as the modification of graphene with organic molecules, functionalization by metal oxide or noble metals, and nanostructural engineering. Particular emphasis is also provided to clarify the mechanism for the gas sensing enhancement. Further, the sensor device design is also concerned for the significant effect on reaching full potential of the gas sensing materials and realizing multifunctional integration. Finally, the opportunities and challenges for the development of gas sensors are pointed out.


Assuntos
Grafite , Nanoestruturas , Metais , Óxidos
13.
Se Pu ; 39(9): 941-949, 2021 Sep.
Artigo em Chinês | MEDLINE | ID: mdl-34486833

RESUMO

Sample pretreatment technology plays a vital role throughout the analysis of complex samples. Sample pretreatment can not only increase the concentration of trace targets in the sample, but also effectively eliminate interference from the sample matrix in instrumental analysis. Adsorbent materials are a key component of sample pretreatment technology. Therefore, the development of efficient and stable new adsorbent materials has acquired significance in research on pretreatment technology. Porous materials are advantageous for use in diverse applications, such as in adsorbents, when they possess controllable nanostructures, a tailored pore surface chemistry, and abundant porosity, and are inexpensive. Particularly in recent years, porous materials derived from metal-organic frameworks (MOFs) feature excellent properties, such as diverse morphology and structure, adjustable pore size, high specific surface area, good thermal stability, and chemical resistance. MOF-derived materials, when used as adsorbents for sample pretreatment, offer the following advantages: (1) The porous materials derived from MOFs typically possess a larger specific surface area than other porous materials. This characteristic is beneficial to improve the extraction capacity and extraction efficiency via an increase in the contact area between the materials and targets; (2) The microscopic porous structure of MOF-derived materials can be easily tuned (by controlling the temperature and time during pyrolysis, gas atmosphere, and heating rate), which is conducive to improve the selectivity of sample pretreatment methods; (3) The metal active sites can be evenly distributed. Owing to the ordered distribution of metal ions in the precursor MOFs and a good periodic framework structure, the metal active sites of the derivatives formed can still maintain a corresponding distance. These metal active sites will not form agglomerates and affect the extraction performance; conversely, other porous materials often require extremely complicated processes to achieve a uniform distribution; (4) Heteroatoms such as nitrogen and sulfur can be easily doped on the framework of MOF-derived porous materials. This doping enables the materials to induce additional interactions such as hydrogen bonding and π-π stacking for adsorbing target analytes. The excellent properties of MOF-derived materials make them promising for use in sample pretreatment. Novel sample pretreatment methods that use MOF-derived materials are constantly being developed. However, the use of MOF-derived materials is limited by the complex preparation process and high production cost of MOF precursors, along with difficulties in mass production. Further, the precise design or functionalization of MOF-derived materials according to the characteristics of targets is a new direction with immense challenges as well as application potential. This review summarizes the application of MOF-derived materials in sample pretreatment methods, including dispersive solid phase extraction (dSPE), magnetic solid phase extraction (MSPE), solid phase microextraction (SPME), stir bar sorptive extraction (SBSE), and dispersive micro solid phase extraction (DMSPE). The preparation methods, functional control, and enrichment efficiencies of various MOF-derived materials are also reviewed. Finally, the application prospects of MOF-derived materials in sample pretreatment are discussed to provide a clear outlook and reference for further related research.


Assuntos
Estruturas Metalorgânicas , Íons , Metais , Extração em Fase Sólida , Microextração em Fase Sólida
14.
Anal Chim Acta ; 1179: 338830, 2021 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-34535263

RESUMO

Microfluidics coupled on-line with ICP-MS detection can be combined with powerful quantitation procedures that take advantage of internal standardization and standard additions, such as the recently introduced Standard Dilution Analysis (SDA). Although so far used at mL min-1 flow rates, here we demonstrate that SDA can be conveniently employed with a microfluidic chip-based ICP-MS system to improve determination accuracy for various sample types, including water, biological and cell digest samples, analyzed at µL min-1 flow rates. The efficient coupling of a microfluidic chip to ICP-MS was accomplished using a combination of commercially available components, including a pneumatic high-efficiency nebulizer and a spray chamber designed to allow for the addition of a laminar flow makeup gas. The addition of the makeup gas was crucial in order to avoid detrimental suction effects that can disrupt the operation of the microfluidic chip and cause signal instability, while it still allowed for the highly sensitive detection of metal isotopes by using ICP-MS. All mixing and dilution operations of the sample with the two calibration solutions required for SDA were performed in an automated and highly reproducible fashion on the microfluidic chip with the assistance of an external distributor valve. High average recoveries (97.4-100.1%) and low average relative standard deviations (2.9-4.8%) were achieved for the determined elements (Cd, Co, Pb, Cr) across several spiked matrices and certified reference materials, whereas only 140 µL of sample is required for SDA in triplicate or 40 µL for a single analysis. Hence, accuracy, precision, limited sample consumption, and the elimination of the need for manual sample dilution and mixing manipulations are some of the advantages of this newly developed chip-based microfluidic SDA ICP-MS technique.


Assuntos
Metais , Microfluídica , Calibragem , Espectrometria de Massas , Análise Espectral
15.
Anal Chim Acta ; 1180: 338897, 2021 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-34538312

RESUMO

An europium functionalized metal-organic fluorescent probe, Eu3+@UiO-66-FDC was constructed by post-synthetic modification through coordination interactions. Eu3+@UiO-66-FDC displayed high selectivity and sensitivity toward Tryptophan (Trp) among all the 20 natural amino acids and other general compounds in food and biological samples, with a wide linear concentration range (0-1000 µM), low detection limit (0.29 µM), and a rapid response (<1 min). Besides, this probe was utilized to detect Trp in rabbit blood serum and milk samples with good recoveries, which were verified by high-performance liquid chromatography (HPLC). Notably, this fluorescent probe proved to be a recyclable material. Hence, this work provides a reliable and recyclable fluorescent probe applicable toward the detection of Trp in biological fluids and/or food products.


Assuntos
Európio , Corantes Fluorescentes , Animais , Metais , Coelhos , Triptofano
16.
Sensors (Basel) ; 21(17)2021 Sep 05.
Artigo em Inglês | MEDLINE | ID: mdl-34502849

RESUMO

The development of silicon-based sensor devices has enabled the possibility to pursue novel integrated smart sensor technologies. Under this scenario, capacitive sensor devices are one viable option for implementing different kinds of applications. In this paper, an interdigitated coplanar capacitive device fabricated over a silicon substrate is presented and its potential use as liquid sensor is demonstrated. Additionally, a detailed capacitance model, which includes the parasitic capacitances introduced by the silicon substrate, was developed. The capacitance model has been theoretically validated through finite-element simulations as well as experimentally by comparison with fabricated devices. A polydimethylsiloxane mold has been fabricated and bonded to the sensor device with the aim of defining a cavity to collect the liquid sample into the device's active region. The active capacitance component correlates to the electric field coupling between adjacent metal lines. Therefore, any change to the dielectric constant of the medium above the coplanar metal lines will produce a change to the device capacitance. Finally, the main guidelines for device performance improvement are depicted.


Assuntos
Metais , Silício , Capacitância Elétrica
17.
Langmuir ; 37(38): 11292-11300, 2021 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-34516132

RESUMO

Nanoengineered capsules encapsulated with functional cargos (e.g., enzymes) are of interest for various applications including catalysis, bioreactions, sensing, and drug delivery. Herein, we report a facile strategy to engineer enzyme-encapsulated metal-phenolic network (MPN) capsules using enzyme-loaded zeolitic imidazolate framework nanoparticles (ZIF-8 NPs) as templates, which can be removed in a mild condition (e.g., ethylenediaminetetraacetic acid (EDTA) solution). The capsule size (from 250 nm to 1 µm) and thickness (from 9.8 to 33.7 nm) are well controlled via varying the template size and coating time, respectively. Importantly, MPN capsules encapsulated with enzymes (i.e., glucose oxidase) can trigger the intracellular cascade reaction via the exhaustion of glucose to produce H2O2 and subsequently generate toxic hydroxyl radicals (•OH) based on the Fenton reaction via the reaction between H2O2 and iron ions in MPN coatings. The intracellular cascade reaction for the generation of •OH is efficient to inhibit cancer cell viability, which is promising for the application in chemodynamic therapy.


Assuntos
Peróxido de Hidrogênio , Nanopartículas , Cápsulas , Catálise , Metais
18.
Sci Rep ; 11(1): 19216, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34584143

RESUMO

Global health organizations recommend the use of cloth face coverings to slow the spread of COVID-19. Seemingly overnight, companies whose primary business is in no way related to healthcare or personal protective equipment-from mattresses manufacturers to big box stores-transitioned into the "mask business." Many companies advertise antimicrobial masks containing silver, copper, or other antimicrobials. Often, the techniques used to load such antimicrobials onto mask fibers are undisclosed, and the potential for metal leaching from these masks is yet unknown. We exposed nine so-called "antimicrobial" face masks (and one 100% cotton control mask) to deionized water, laundry detergent, and artificial saliva to quantify the leachable silver and copper that may occur during mask washing and wearing. Leaching varied widely across manufacturer, metal, and leaching solution, but in some cases was as high as 100% of the metals contained in the as-received mask after 1 h of exposure.


Assuntos
COVID-19/prevenção & controle , Máscaras , Equipamento de Proteção Individual , Anti-Infecciosos , Filtração , Humanos , Máscaras/virologia , Metais , Equipamento de Proteção Individual/virologia , SARS-CoV-2 , Têxteis
19.
Molecules ; 26(17)2021 Aug 26.
Artigo em Inglês | MEDLINE | ID: mdl-34500599

RESUMO

Agaricus bisporus (J.E. Lange) Imbach is one the most popular species of edible mushrooms in the world because of its taste and nutritional properties. In the research, repeatability of accumulation of bioelements and biomass yield in experimentally chosen in vitro culture medium, was confirmed. The in vitro cultures were conducted on the modified Oddoux medium enriched with bioelements (Mg, Zn, Cu, Fe). The aim of the study was to create an effective method of sampling, which enabled non-invasive monitoring of metals concentrations changes in the medium, during increase of biomass in in vitro cultures. The first, indirect method of sampling was applied. The non-invasive probe (a dipper) for in vitro culture was used; hence, the highest biomass increase and metals accumulation were gained. The method also guaranteed culture sterility. The second method, a direct one, interfered the in vitro culture conditions and growth of mycelium, and as a consequence the lower biomass increase and metals' accumulation were observed. Few cases of contaminations of mycelium in in vitro cultures were observed. The proposed method of non-invasive sampling of the medium can be used to monitor changes in the concentrations of metals in the medium and their accumulation in the mycelium in natural environment. Changes in concentrations of the selected metals over time, determined by the method of atomic absorption spectrometry, made it possible to correlate the obtained results with the specific stages of A. bisporus mycelium development and to attempt to explain the mechanism of sampling metals from the liquid substrate.


Assuntos
Agaricus/metabolismo , Biotecnologia/métodos , Meios de Cultura/metabolismo , Biomassa , Metais/metabolismo , Micélio/metabolismo , Espectrofotometria Atômica/métodos
20.
Sensors (Basel) ; 21(18)2021 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-34577205

RESUMO

With characters of low cost, portability, easy disposal, and high accuracy, as well as bulky reduced laboratory equipment, paper-based sensors are getting increasing attention for reliable indoor/outdoor onsite detection with nonexpert operation. They have become powerful analysis tools in trace detection with ultra-low detection limits and extremely high accuracy, resulting in their great popularity in medical detection, environmental inspection, and other applications. Herein, we summarize and generalize the recently reported paper-based sensors based on their application for mechanics, biomolecules, food safety, and environmental inspection. Based on the biological, physical, and chemical analytes-sensitive electrical or optical signals, extensive detections of a large number of factors such as humidity, pressure, nucleic acid, protein, sugar, biomarkers, metal ions, and organic/inorganic chemical substances have been reported via paper-based sensors. Challenges faced by the current paper-based sensors from the fundamental problems and practical applications are subsequently analyzed; thus, the future directions of paper-based sensors are specified for their rapid handheld testing.


Assuntos
Laboratórios , Ácidos Nucleicos , Hospitais , Metais , Compostos Orgânicos
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