RESUMEN
INTRODUCTION: Volatile organic compounds (VOCs) in breath serve as a source of biomarkers for medical conditions relevant to warfighter health including Corona Virus Disease and other potential biological threats. Electronic noses are integrated arrays of gas sensors that are cost-effective and miniaturized devices that rapidly respond to VOCs in exhaled breath. The current study seeks to qualify healthy breath baselines of exhaled VOC profiles through analysis using a commercialized array of metal oxide (MOX) sensors. MATERIALS AND METHODS: Subjects were recruited/consented through word of mouth and using posters. For each sample, breath was analyzed using an array of MOX sensors with parameters that were previously established. Data were also collected using a lifestyle questionnaire and from a blood test to assess markers of general health. Sensor data were processed using a feature extraction algorithm, which were analyzed through statistical approaches to identify correlations with confounding factors. Reproducibility was also assessed through relative standard deviation values of sensor features within a single subject and between different volunteers. RESULTS: A total of 164 breath samples were collected from different individuals, and 10 of these volunteers provided an additional 9 samples over 6 months for the longitudinal study. First, data from different subjects were analyzed, and the trends of the 17 extracted features were elucidated. This revealed not only a high degree of correlation between sensors within the array but also between some of the features extracted within a single sensor. This helped guide the removal of multicollinear features for multivariate statistical analyses. No correlations were identified between sensor features and confounding factors of interest (age, body mass index, smoking, and sex) after P-value adjustment, indicating that these variables have an insignificant impact on the observed sensor signal. Finally, the longitudinal replicates were analyzed, and reproducibility assessment showed that the variability between subjects was significantly higher than within replicates of a single volunteer (P-value = .002). Multivariate analyses within the longitudinal data displayed that subjects could not be distinguished from one another, indicating that there may be a universal healthy breath baseline that is not specific to particular individuals. CONCLUSIONS: The current study sought to qualify healthy baselines of VOCs in exhaled breath using a MOX sensor array that can be leveraged in the future to detect medical conditions relevant to warfighter health. For example, the results of the study will be useful, as the healthy breath VOC data from the sensor array can be cross-referenced in future studies aiming to use the device to distinguish disease states. Ultimately, the sensors may be integrated into a portable breathalyzer or current military gear to increase warfighter readiness through rapid and noninvasive health monitoring.
Asunto(s)
Pruebas Respiratorias , Compuestos de Estaño , Compuestos Orgánicos Volátiles , Humanos , Pruebas Respiratorias/métodos , Pruebas Respiratorias/instrumentación , Masculino , Adulto , Femenino , Compuestos de Estaño/análisis , Compuestos Orgánicos Volátiles/análisis , Persona de Mediana Edad , Reproducibilidad de los Resultados , Monitoreo Fisiológico/métodos , Monitoreo Fisiológico/instrumentación , Encuestas y Cuestionarios , Biomarcadores/análisis , Nariz Electrónica/normas , Estudios LongitudinalesRESUMEN
A photoelectrochemical (PEC) biosensor based on SnO2 nanoparticles (SnO2 NPs) was developed and applied for phosphatidylcholine (PC) detection in soybean oil. SnO2 NPs were grown on an indium tin oxide (ITO) electrode, polythionine (PTh) was electropolymerized on the surface of ITO/SnO2 NPs, and choline oxidase (ChOx) was immobilized to prepare the ITO/SnO2 NPs/PTh/ChOx electrode. The developed PEC biosensor can detect PC under visible light irradiation. The experimental conditions for PC detection were as follows: 1.8 mg mL-1 ChOx concentration, 0.5 V bias voltage, 18 mW cm-2 light intensity, and pH 6. The PEC biosensor had a detection limit of 0.005 mM (S/N = 3) and a detection range from 0.03 mM to 4 mM. This PEC biosensor based on SnO2 NPs was applied to detect PC in soybean oil. The recovery rate tested by the standard addition method was 95.2-107.4%. These findings were consistent with the results obtained by high-performance liquid chromatography (HPLC). Therefore, the proposed PEC biosensor based on SnO2 NPs has excellent reproducibility, stability, and great potential applications in the PEC analysis of PC in soybean oil.
Asunto(s)
Técnicas Biosensibles , Nanopartículas , Técnicas Biosensibles/métodos , Técnicas Electroquímicas , Nanopartículas/química , Fosfatidilcolinas/análisis , Fosfatidilcolinas/química , Reproducibilidad de los Resultados , Aceite de Soja , Compuestos de Estaño/análisis , Compuestos de Estaño/químicaRESUMEN
Indium tin oxide exposure poses a potential health risk, but the exposure assessment in occupational setting remains incomplete and continues to be a significant challenge. To this end, we investigated the association of work type, airborne indium concentration, respirable fraction of total indium, and cumulative indium exposure index (CEI) with the levels of plasma indium (P-In) and urinary indium (U-In) among 302 indium tin oxide target manufacturing and recycling workers in Taiwan. We observed that recycling-crushing produced the highest concentrations of total indium (area: 2084.8 µg/m3; personal: 3494.5 µg/m3) and respirable indium (area: 533.4 µg/m3; personal: 742.0 µg/m3). Powdering produced the highest respirable fraction of total indium (area: 58.6%; personal: 81.5%), where the workers had the highest levels of P-In (geometric mean: 2.0 µg/L) and U-In (1.0 µg/g creatinine). After adjusting for the confounder, the CEIs of powdering (ßPR = 0.78; ßPR = 0.44), bonding (ßPT = 0.61; ßPT = 0.37), and processing workers (ßPT = 0.43; ßPT = 0.28) showed significant associations with P-In and U-In, validating its utility in monitoring the exposure. Also, the respirable fraction of total indium significantly contributed to the increased levels of P-In and U-In among workers. The varying levels of relationship noted between indium exposure and the levels of P-In and U-In among workers with different work types suggested that setting the exposure limits among different work types is warranted.
Asunto(s)
Exposición Profesional , Humanos , Indio/análisis , Exposición Profesional/análisis , Taiwán , Compuestos de Estaño/análisisRESUMEN
2,4-Dichlorophenol (2,4-DCP) is a hazardous chlorinated organic chemical derived from phenol that exerts serious effects on living organisms. In the present study, SnO2 templated with grapefruit peel carbon as a nanocomposite (SnO2@GPC) was designed via ball-milling, and its mechanism of 2,4-DCP adsorption in aqueous solution was determined. Batch adsorption experiments revealed that the maximum adsorption efficiency of SnO2@GPC occurred at 6.0 pH, 3 mg L-1 initial adsorbate concentration, 2 h contact time, and 293 K temperature. The SnO2@GPC nanocomposite and its non-tin-bearing counterpart, grapefruit derived char (@GPC), showed maximum adsorption capacities (QL) of 45.95 and 22.09 mg g-1 and partition coefficients of 41.77 and 10.83 mg g-1 µM-1, respectively. The adsorption of 2,4-DCP was best described by the Redlich-Peterson model followed by the Langmuir model with high correlation coefficients (R2 ≥ 0.96), and the adsorption kinetic data best fitted the pseudo-second-order model (R2 ≥ 0.98). The thermodynamic parameters indicated that the reaction was spontaneous, exothermic, and involved high affinity between SnO2@GPC and 2,4-DCP. The high desorption efficiency obtained (>80%) demonstrated the recyclability of the adsorbent. The enhanced QL of SnO2@GPC was due to the effective combination of GPC and SnO2. A thin porous layer of GPC on SnO2 nanoparticles provided effective channels, a large surface area, and an abundance of active sites for 2,4-DCP adsorption. Thus, the SnO2@GPC nanocomposite could potentially be used as a low-cost adsorbent to remove 2,4-DCP from water.
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Clorofenoles/química , Nanocompuestos , Compuestos de Estaño/análisis , Contaminantes Químicos del Agua , Purificación del Agua , Adsorción , Biomasa , Concentración de Iones de Hidrógeno , Cinética , Fenoles , TermodinámicaRESUMEN
Surface grinding workers of Indium Tin Oxide target material are exposed to an indium compound with high toxicity. We divided individual exposure workers into similar exposure groups (SEG) and examined the effectiveness of the classification of SEG. Sampling was carried out twice a day for a total of 10 times, in 9 of which a work environment measurement in unit work area was performed at the same time. The classification examined two methods. One method was to set all the workers in the work place as one group (SEG1), and the other was to classify them depending on whether the workers handled the target material contained indium or not (SEG2). The group handled indium-contained material was SEG2(+) n=9, and the other was SEG2(-) n=9. Only the arithmetic mean value (AM) of four groups 2.8-27.4 µg/m3 in the SEG2(+) was lower than the measurement B value of the work environment measurement, but the AM of all the groups in SEG2(+) 2.8-276.8 µg/m3 was higher than the geometric mean value of measurement A 0.4-12.3 µg/m3. The concentration range of 100 µg/m3 or more of SEG2(+) AM was 20% of the total. This range was not recognized in the other items, and the variation of SEG2(+) was small. Even though the evaluation of SEG1 is control class 2, if revaluated on SEG2(+), 50% of the SEG2(+) were evaluated as control class 3. It is possible to efficiently manage chemical substances by establishing specific SEG properly stratified.
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Exposición Profesional , Compuestos de Estaño/análisis , HumanosRESUMEN
A method for producing simple and efficient thermally-activated delayed fluorescence organic light-emitting diodes (OLEDs) based on guest-host or exciplex donor-acceptor emitters is presented. With a step-by-step procedure, readers will be able to repeat and produce OLED devices based on simple organic emitters. A patterning procedure allowing the creation of personalized indium tin oxide (ITO) shape is shown. This is followed by the evaporation of all layers, encapsulation and characterization of each individual device. The end goal is to present a procedure that will give the opportunity to repeat the information presented in cited publication but also using different compounds and structures in order to prepare efficient OLEDs.
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Fenómenos Químicos Orgánicos , Compuestos de Estaño/síntesis química , Vacio , Fluorescencia , Láseres de Semiconductores , Compuestos de Estaño/análisisRESUMEN
Based on migration procedures using simulated gastric juice specified in the EU toy Safety Standard EN 71-3:2013/A2:2017, a method was developed for the determination of monomethyltin (MMT) migration from toys by gas chromatography-mass spectrometry (GC-MS). Further, a reliable confirmation method for judgement of a false positive for MMT obtained by GC-MS, was established. After optimizing the migration conditions, derivatization steps and chromatographic parameters, the method yielded a linear range from 0.02 to 1.0 mg/L with a correlation coefficient (R2) of 0.9992. The limits of detection and quantification of the method were 0.11 and 0.32 mg/kg, respectively. The recoveries were 86.2%-104.2% under different spiked levels (0.5, 1.0 and 1.5 µg), and the relative standard deviations were 3.1%-8.2% (n=6). MMT migration ranging from 0.44 to 0.67 mg/kg was detected in the surface coating of tin-plating (Sn-Fe alloy) toy materials, which was subsequently confirmed to be false positive. Therefore, a novel confirmative approach using methanol or acetone as the migration solvent was proposed, aiming at verifying the false positive of MMT. The results showed that the previously positive MMT detected by GC-MS could no longer be detected when treated by these migration solvents.Hence, this approach can be used to confirm false positive detected for MMT after GC-MS detection.
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Cromatografía de Gases y Espectrometría de Masas , Juego e Implementos de Juego , Compuestos de Estaño/análisis , Metanol , SolventesRESUMEN
One of the most important features of photocatalytic materials intended to be used for water treatment is their long-term stability. The study is focused on the application of thermal and chemical treatments for the reactivation of TiO2-SnS2 composite photocatalyst, prepared by hydrothermal synthesis and immobilized on the glass support using titania/silica binder. Such a catalytic system was applied in solar-driven treatment, solar/TiO2-SnS2/H2O2, for the purification of water contaminated with diclofenac (DCF). The effectiveness of studied reactivation methods for retaining TiO2-SnS2 activity in consecutive cycles was evaluated on basis of DCF removal and conversion, and TOC removal and mineralization of organic content. Besides these water quality parameters, biodegradability changes in DCF aqueous solution treated by solar/TiO2-SnS2/H2O2 process using simply reused (air-dried) and thermally and chemically reactivated composite photocatalyst through six consecutive cycles were monitored. It was established that both thermal and chemical reactivation retain TiO2-SnS2 activity in the second cycle of its reuse. However, both treatments caused the alteration in the TiO2-SnS2 morphology due to the partial transformation of visible-active SnS2 into non-active SnO2. Such alteration, repeated through consecutive reactivation and reuse, was reflected through gradual activity loss of TiO2-SnS2 composite in applied solar-driven water treatment.
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Diclofenaco/química , Energía Solar , Sulfuros/análisis , Compuestos de Estaño/análisis , Titanio/análisis , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , FotólisisRESUMEN
The growing number of nanotechnology products on the market will inevitably lead to the release of engineered nanomaterials with potential risk to humans and environment. This study set out to investigate the exposure of soil biota to engineered nanoparticles (NPs). Cerium dioxide (CeO2 NPs) and tin dioxide nanoparticles (SnO2 NPs) were radiolabelled using neutron activation, and employed to assess the uptake and excretion kinetics in the earthworm Eisenia fetida. Through sequential extraction, NPs bioavailability in two contrasting soils and in earthworm feed was also investigated. Neither CeO2 NPs nor SnO2 NPs bioaccumulated in earthworms, and both were rapidly excreted when worms were transferred to clean soil. Low bioavailability was also indicated by low amounts of NPs recovered during extraction with non-stringent extractants. CeO2 NPs showed increasing mobility in organic soil over time (28 days), indicating that organic matter has a strong influence on the fate of CeO2 NPs in soil.
Asunto(s)
Cerio/metabolismo , Nanopartículas del Metal/análisis , Oligoquetos/metabolismo , Contaminantes del Suelo/metabolismo , Compuestos de Estaño/metabolismo , Animales , Cerio/análisis , Suelo , Contaminantes del Suelo/análisis , Compuestos de Estaño/análisisRESUMEN
BACKGROUND: Workers manufacturing indium-tin oxide (ITO) are at risk of elevated indium concentration in blood and indium lung disease, but relationships between respirable indium exposures and biomarkers of exposure and disease are unknown. METHODS: For 87 (93%) current ITO workers, we determined correlations between respirable and plasma indium and evaluated associations between exposures and health outcomes. RESULTS: Current respirable indium exposure ranged from 0.4 to 108 µg/m(3) and cumulative respirable indium exposure from 0.4 to 923 µg-yr/m(3) . Plasma indium better correlated with cumulative (rs = 0.77) than current exposure (rs = 0.54) overall and with tenure ≥1.9 years. Higher cumulative respirable indium exposures were associated with more dyspnea, lower spirometric parameters, and higher serum biomarkers of lung disease (KL-6 and SP-D), with significant effects starting at 22 µg-yr/m(3) , reached by 46% of participants. CONCLUSIONS: Plasma indium concentration reflected cumulative respirable indium exposure, which was associated with clinical, functional, and serum biomarkers of lung disease. Am. J. Ind. Med. 59:522-531, 2016. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.
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Indio/sangre , Enfermedades Pulmonares/inducido químicamente , Exposición Profesional/análisis , Compuestos de Estaño/análisis , Adulto , Contaminantes Ocupacionales del Aire/análisis , Biomarcadores/análisis , Biomarcadores/sangre , Monitoreo del Ambiente , Humanos , Indio/efectos adversos , Enfermedades Pulmonares/diagnóstico , Persona de Mediana Edad , Exposición Profesional/efectos adversos , Ocupaciones , Espirometría , Compuestos de Estaño/efectos adversosRESUMEN
Sustainable valorization processes for selective recovery of pure copper nanopowder from Indium-Tin-Oxide (ITO) etching wastewater by various wet chemical reduction processes, their chemistry has been investigated and compared. After the indium recovery by solvent extraction from ITO etching wastewater, the same is also an environmental challenge, needs to be treated before disposal. After the indium recovery, ITO etching wastewater contains 6.11kg/m(3) of copper and 1.35kg/m(3) of aluminum, pH of the solution is very low converging to 0 and contain a significant amount of chlorine in the media. In this study, pure copper nanopowder was recovered using various reducing reagents by wet chemical reduction and characterized. Different reducing agents like a metallic, an inorganic acid and an organic acid were used to understand reduction behavior of copper in the presence of aluminum in a strong chloride medium of the ITO etching wastewater. The effect of a polymer surfactant Polyvinylpyrrolidone (PVP), which was included to prevent aggregation, to provide dispersion stability and control the size of copper nanopowder was investigated and compared. The developed copper nanopowder recovery techniques are techno-economical feasible processes for commercial production of copper nanopowder in the range of 100-500nm size from the reported facilities through a one-pot synthesis. By all the process reported pure copper nanopowder can be recovered with>99% efficiency. After the copper recovery, copper concentration in the wastewater reduced to acceptable limit recommended by WHO for wastewater disposal. The process is not only beneficial for recycling of copper, but also helps to address environment challenged posed by ITO etching wastewater. From a complex wastewater, synthesis of pure copper nanopowder using various wet chemical reduction route and their comparison is the novelty of this recovery process.
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Cobre/aislamiento & purificación , Indio/análisis , Residuos Industriales/análisis , Nanopartículas , Reciclaje/métodos , Compuestos de Estaño/análisis , Aguas Residuales/química , Concentración de Iones de Hidrógeno , Oxidación-Reducción , Polvos , SolucionesRESUMEN
This article aimed to elucidate the physicochemical characteristics and exposure concentration of powder and airborne particles as byproducts generated from indium tin oxide thin film process by an electron beam evaporation method during maintenance in light-emitting diode manufacturing environment. The chemical composition, size, shape, and crystal structure of powder and airborne particles as byproducts were investigated using a scanning electron microscope equipped with energy dispersive spectrometer, and an X-ray diffractometer. The number and mass concentration measurements of airborne particles were performed by using an optical particle counter of direct-reading aerosol monitor and an inductively coupled plasma-mass spectrometry after sampling, respectively. The airborne particles are composed of oxygen and indium. On the other hand, the powder byproducts consist mostly of oxygen and indium, but tin was found as a minor component. The shapes of the airborne and powder byproducts were fiber type. The length and diameter of fibrous particles were approximately 500-2,000 nm and 30-50 nm, respectively. The powder byproducts indicated indium oxide nanofibers with a rhombohedral structure. On the other hand, the indium oxide used as a source material in the preparation of ITO target showed spherical morphology with a body-centered cubic structure, and it was the same as that of the pure crystalline indium oxide powder. During maintenance, the number concentrations ranged from 350-75,693 particles/ft(3), and arithmetic mean±standard deviation and geometric mean±geometric standard deviation were 11,624±15,547 and 4,846±4.12 particles/ft(3), respectively. Meanwhile, under the same conditions, the airborne mass concentrations of the indium based on respirable particle size (3.5 µm cut-point 50%) were 0.09-0.19 µg/m(3). Physicochemical characteristics of nanoparticle can affect toxicity so the fact that shape and crystal structure have changed is important. Thus, nanoparticle occupational toxicology greatly needs observations like this.
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Indio/análisis , Nanofibras/análisis , Contaminantes Ocupacionales del Aire/análisis , Monitoreo del Ambiente/métodos , Indio/química , Industria Manufacturera , Microscopía Electrónica de Rastreo , Nanofibras/química , Tamaño de la Partícula , Polvos/análisis , Compuestos de Estaño/análisis , Lugar de TrabajoRESUMEN
Butyltins (BTs), polyaromatic hydrocarbons (PAHs), organochlorine pesticides (OCPs), and polychlorinated biphenyls (PCBs) were assessed in a mid-latitude environment of the Patagonian coast, distant from significant pollutant sources. Bioaccumulation processes through bottom sediment resuspension were suggested by BTs level (expressed as ng of tin [Sn] g(-1) dry wt) found in surface sediment (Asunto(s)
Bivalvos/metabolismo
, Sedimentos Geológicos/análisis
, Hidrocarburos Clorados/análisis
, Insecticidas/análisis
, Hidrocarburos Policíclicos Aromáticos/análisis
, Compuestos de Estaño/análisis
, Contaminantes Químicos del Agua/análisis
, Animales
, Argentina
, Bivalvos/química
, Límite de Detección
, Bifenilos Policlorados/análisis
, Control de Calidad
RESUMEN
The polybrominated flame retardants and organotin compounds were screened in terms of bromine and tin content using laser ablation inductively coupled plasma mass spectrometry in plastics. The calibration standards were prepared using the fused-disk technique, and all samples were investigated under optimal conditions. Using a central composite experimental design, laser parameters, laser energy, pulse rate, scan rate and spot size were identified. The detection limits of the method were 1000 mgkg(-1) and 1600 mgkg(-1) for bromide and tin, whereas the relative standard deviation (%) values of the analysis were 9% and 6% (n=3) for ERM EC681k with 770 ± 70 mgkg(-1) Br and 86 ± 6 mgkg(-1) Sn respectively, and 106-115% of Br and 102-104% of Sn were observed for the tetrabromobisphenol A and butyltin trichloride spike plastics, respectively.
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Bromo/análisis , Retardadores de Llama/análisis , Terapia por Láser , Espectrometría de Masas/métodos , Plásticos/química , Compuestos de Estaño/análisis , CalibraciónRESUMEN
Confocal microscopy imaging of cells allows to visualize the presence of specific antigens by using fluorescent tags or fluorescent proteins, with resolution of few hundreds of nanometers, providing their localization in a large field-of-view and the understanding of their cellular function. Conversely, in scanning electron microscopy (SEM), the surface morphology of cells is imaged down to nanometer scale using secondary electrons. Combining both imaging techniques have brought to the correlative light and electron microscopy, contributing to investigate the existing relationships between biological surface structures and functions. Furthermore, in SEM, backscattered electrons (BSE) can image local compositional differences, like those due to nanosized gold particles labeling cellular surface antigens. To perform SEM imaging of cells, they could be grown on conducting substrates, but obtaining images of limited quality. Alternatively, they could be rendered electrically conductive, coating them with a thin metal layer. However, when BSE are collected to detect gold-labeled surface antigens, heavy metals cannot be used as coating material, as they would mask the BSE signal produced by the markers. Cell surface could be then coated with a thin layer of chromium, but this results in a loss of conductivity due to the fast chromium oxidation, if the samples come in contact with air. In order to overcome these major limitations, a thin layer of indium-tin-oxide was deposited by ion-sputtering on gold-decorated HeLa cells and neurons. Indium-tin-oxide was able to provide stable electrical conductivity and preservation of the BSE signal coming from the gold-conjugated markers.
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Microscopía Confocal/métodos , Microscopía Electrónica de Rastreo/métodos , Compuestos de Estaño/análisis , Conductividad Eléctrica , Células HeLa , Humanos , Inmunohistoquímica , Método de Montecarlo , Coloración y EtiquetadoRESUMEN
Integrating a disposable ITO electrode modified by gold nanorod-chitosan nanocomposites, a paper-based electroanalytical device for the real-time detection of H2O2 released from cancer cells has been developed. It provided a portable platform for biological and biomedical studies dealing with living cells.
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Quitosano/química , Oro/química , Peróxido de Hidrógeno/química , Nanotubos , Neoplasias/metabolismo , Compuestos de Estaño/análisis , Catálisis , Límite de Detección , Neoplasias/patologíaRESUMEN
Terahertz (THz) waves have been exploited for the non-contact measurements of thickness and refractive index, which has enormous industrial applicability. In this work, we demonstrate a 1.3-µm dual-mode laser (DML)-based continuous-wave THz system for the real-time measurement of a commercial indium-tin-oxide (ITO)-coated glass. The system is compact, cost-effective, and capable of performing broadband measurement within a second at the setting resolution of 1 GHz. The thickness of the glass and the sheet conductivity of the ITO film were successfully measured, and the measurements agree well with those of broadband pulse-based time domain spectroscopy and Hall measurement results.
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Conductometría/instrumentación , Vidrio/química , Rayos Láser , Ensayo de Materiales/instrumentación , Fotometría/instrumentación , Radiación Terahertz , Compuestos de Estaño/química , Conductividad Eléctrica , Compuestos de Estaño/análisisRESUMEN
Soot soiling is a crucial forensic parameter around gunshot lesions. Carbonization, however, can severely alter human tissues and mimic such clues. This study aims at evaluating the survival of soot soiling even after carbonization in bone. A total of 36 bovine ribs (half fleshed and half defleshed) were shot with two types of bullet (both 9-mm; full metal-jacketed and unjacketed) with a near-contact range. With unjacketed bullets, the shot left in every case a clear, black, and roughly round soot stain around the entrance wound, whereas full metal-jacketed bullets left no signs of soot. Every specimen then underwent calcination in an oven at 800°C. The analysis of the charred samples clearly showed the survival of the soot soiling in both fleshed and bony samples, with a clear correspondence with the former position, but with a different color (yellow). Thus, soot soiling may survive, although with a different color, even after charring.
Asunto(s)
Quemaduras/patología , Costillas/patología , Hollín/química , Heridas por Arma de Fuego/patología , Animales , Antimonio/análisis , Bovinos , Color , Balística Forense , Calor , Plomo/análisis , Microscopía , Microscopía Electrónica de Rastreo , Modelos Animales , Óxidos/análisis , Costillas/lesiones , Compuestos de Estaño/análisisRESUMEN
Indium use has increased greatly in the past decade in parallel with the growth of flat-panel displays, touchscreens, optoelectronic devices, and photovoltaic cells. Much of this growth has been in the use of indium tin oxide (ITO). This increased use has resulted in more frequent and intense exposure of workers to indium. Starting with case reports and followed by epidemiological studies, exposure to ITO has been linked to serious and sometimes fatal lung disease in workers. Much of this research was conducted in facilities that process sintered ITO, including manufacture, grinding, and indium reclamation from waste material. Little has been known about indium exposure to workers in downstream applications. In 2009-2011, the National Institute for Occupational Safety and Health (NIOSH) contacted 89 potential indium-using companies; 65 (73%) responded, and 43 of the 65 responders used an indium material. Our objective was to identify current workplace applications of indium materials, tasks with potential indium exposure, and exposure controls being used. Air sampling for indium was either conducted by NIOSH or companies provided their data for a total of 63 air samples (41 personal, 22 area) across 10 companies. Indium exposure exceeded the NIOSH recommended exposure limit (REL) of 0.1 mg/m(3) for certain methods of resurfacing ITO sputter targets, cleaning sputter chamber interiors, and in manufacturing some inorganic indium compounds. Indium air concentrations were low in sputter target bonding with indium solder, backside thinning and polishing of fabricated indium phosphide-based semiconductor devices, metal alloy production, and in making indium-based solder pastes. Exposure controls such as containment, local exhaust ventilation (LEV), and tool-mounted LEV can be effective at reducing exposure. In conclusion, occupational hygienists should be aware that the manufacture and use of indium materials can result in indium air concentrations that exceed the NIOSH REL. Given recent findings of adverse health effects in workers, research is needed to determine if the current REL sufficiently protects workers against indium-related diseases.
Asunto(s)
Indio/análisis , Exposición Profesional/análisis , Compuestos de Estaño/análisis , Monitoreo del Ambiente , Humanos , Indio/toxicidad , National Institute for Occupational Safety and Health, U.S. , Valores Limites del Umbral , Compuestos de Estaño/toxicidad , Estados UnidosRESUMEN
A new multilayer-coated varied line-spaced grating, JS4000, was fabricated and tested for extending the upper limit of a grating X-ray spectrometer for electron microscopy. This grating was designed for 2-3.8 keV at a grazing incidence angle of 1.35°. It was revealed that this new multilayer structure enables us to take soft-X-ray emission spectra continuously from 1.5 to 4.3 keV at the same optical setting. The full-width at half maximum of Te-L(α1,2) (3.8 keV) emission peak was 27 eV. This spectrometer was applied to indium tin oxide particles and clearly resolved Sn-L(α) (3444 eV) and In-L(ß1) (3487 eV) peaks, which could not be resolved by a widely used energy-dispersive X-ray spectrometer.