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1.
Materials (Basel) ; 17(18)2024 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-39336342

RESUMO

In response to rising CO2 emissions in the cement industry and the growing demand for durable offshore engineering materials, calcium sulphoaluminate (CSA) cement concrete, known for its lower carbon footprint and enhanced corrosion resistance compared to Ordinary Portland Cement (OPC), is increasingly important. However, the chloride transport behavior of CSA concrete in both laboratory and marine environments remains underexplored and controversial. Accordingly, the chloride ion transport behaviors and mechanisms of CSA concrete in laboratory-accelerated drying-wetting cyclic environments using NaCl solution and seawater, as well as in marine tidal environments, were characterized using the rapid chloride test (RCT), X-ray diffraction (XRD), mercury infiltration porosimetry (MIP), and thermogravimetric analysis (TGA). The results reveal that CSA concrete accumulates more chloride ions in NaCl solution than in seawater, with concentrations 2-3.5 times higher at the same water-cement ratio. Microscopic analysis indicates that calcium and sulfate ions present in seawater facilitate the regeneration of ettringite, thereby increasing the density of the surface pore structure. The hydration and repair mechanisms of CSA concrete under laboratory conditions closely resemble those in marine tidal conditions when exposed to seawater. Additionally, this study found that lower chloride ion concentrations and pH levels inhibit the formation of Friedel's salt. Therefore, laboratory experiments with seawater can effectively simulate CSA concrete's chloride transport properties in marine tidal environments, whereas NaCl solution does not accurately reflect actual marine conditions.

2.
Materials (Basel) ; 17(14)2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39063856

RESUMO

In recent years, wind energy has begun to receive a significant amount of attention as clean energy is utilised and demanded in large quantities, resulting in a sharp increase in the use of wind turbines. The demand for wind turbines has gradually risen due to the clean and recyclable nature of wind energy. The current blade life of wind turbines in China is about 20 years, which means that the disposal of obsolete used blades can become a difficult problem in the future. Therefore, this study is of great significance to explore the regeneration performance of the blades after recycling and disposal. In this paper, wind turbine blades were mechanically recycled into recycled macrofibres, which were added to concrete as a reinforcing material to make wind impeller fibre concrete (WIC), and the three proportion ratios of 1%, 1.5%, and 2% were explored to compare the performance. The performance of WIC was also evaluated and its performance was compared to that of glass fibre concrete (GC). In addition, the material physical properties of second-generation recycled aggregate concrete (RAC) based on WIC were explored. The strength and peak strain variations and their causal mechanisms were analysed both macroscopically and microscopically by means of the classical mechanical tests (compression and bending tests), SEM, and XRD. The results show that the compressive strength of WIC was negatively correlated with the fibre content and increased by 6.04-18.12% compared to that of ordinary concrete (OG), with a maximum of 19.25 MPa; the flexural strength was positively correlated with the fibre content, with an increase of 5.37-18.5%. The microstructural analysis confirmed the macroscopic results and the intrinsic model better validated the experimental results.

3.
J Hazard Mater ; 477: 135278, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39047566

RESUMO

Human hair has become a promising non-invasive matrix in assessing exposure to environmental organic pollutants (OPs). However, exogenous contaminants, which were absorbed into the hair via sweat, sebum, and air particles/dust, could contribute to OP levels in hair and interfere with the precise exposure assessment. So far, the microscopic mechanisms underlying the absorption of exogenous OPs into hair remain inadequately understood. This study focused on the in-situ investigation of the diffusion processes of exogenous OPs into the hair structure using secondary ion mass spectrometry (SIMS) and isotopic tracer techniques. Results showed that the relative signal intensities of deuterium-labeled tris(1,3-dichloro-2-propyl) phosphate (TDCPP), 1-hydroxypyrene (1-OH-Pry), and bisphenol A (BPA) in the hair cortex were notably elevated after a 6-hour exposure. Diffusion coefficients of contaminants were related to their molecular weight, and absorption volumes to their water solubility and molecular structures. Exposure duration and solvent influenced the rate of diffusion and absorption volumes. The distribution of deuterium-labeled molecules in exposed hair samples after washing with two different solvents (acetone or water) was similar to that before washing. Our findings revealed the diffusion of OPs in hair cross-sections, indicating exogenous contributions to contaminants that are biologically incorporated into the hair.


Assuntos
Poluentes Ambientais , Cabelo , Espectrometria de Massa de Íon Secundário , Humanos , Cabelo/química , Poluentes Ambientais/química , Poluentes Ambientais/análise , Compostos Benzidrílicos/análise , Compostos Benzidrílicos/química , Fenóis/análise , Fenóis/química , Feminino , Compostos Orgânicos/análise , Compostos Orgânicos/química , Adulto , Monitoramento Ambiental/métodos , Difusão
4.
Hist Human Sci ; 37(2): 87-116, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38698899

RESUMO

This article examines cinematographic observational studies of infants conducted by a loosely connected group of female psychologists and physicians in the USA from the 1930s to the 1960s. Largely forgotten today, these practitioners realized detailed and carefully planned research projects about infant behavior in a variety of settings-from the laboratory to the well-baby clinic. Although their studies were in conversation with better-known works, such as John Bowlby's research on attachment and René Spitz's films on institutionalized infants, they differed in a close examination of individual characteristics of babies and a critical attitude toward contemporary notions of 'pathological mothering'. In closely following the work of several researchers, including but not limited to pediatrician Margaret Fries (1898-1987), the clinical psychologist Sibylle Escalona (1915-96) and her team members-child psychiatrist Mary Leitch (1914-?) and avant-garde photographer Ellen Auerbach (1906-2004)-and psychologist Anneliese Korner (1918-2010), I argue that their cinematographic works shed a more nuanced light on the landscape of infant research and child psychiatry in the mid 20th century, and open a way for alternative readings of gender, psychoanalysis, and scientific observation at that time.

5.
J Appl Res Intellect Disabil ; 37(4): e13245, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38770887

RESUMO

BACKGROUND: It can be challenging for support staff to develop meaningful moments of interaction with people with profound intellectual disabilities. Gathering information on observable behaviour characterising such meaningful moments is expected to be beneficial. METHOD: Three staff-client dyadic interactions were videotaped for 30 min. During reviewing the recording, staff members indicated which moments of interaction they experienced as meaningful. Per dyad, one meaningful moment was microanalytically coded via a developed coding system, and behaviourally described. RESULTS: The coding system reliably coded behaviour at the micro level. Exploratory results indicated that looking, movement and touching were most shown, and that staff displayed this behaviour more frequently than their clients. Both exhibited behaviours substantially more often during meaningful moments than at their onset. DISCUSSION: People with profound intellectual disabilities are more engaged during meaningful moments of interaction compared to at their onset. In daily practice, cultivating circumstances increasing their involvement is important.


Assuntos
Deficiência Intelectual , Relações Profissional-Paciente , Humanos , Adulto , Masculino , Feminino , Pessoa de Meia-Idade , Adulto Jovem
6.
Materials (Basel) ; 17(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38793389

RESUMO

To perform quality assessments of both metal alloys and many other engineering materials, measurements of the volume fractions of phases or microstructure components are utilized. For this purpose, quantitative analysis of the evaluated components' distribution on metallographic specimens is often employed. Phases or components of the microstructure are identified based on the variation in signal received in the band of light seen. Problems with the correct identification of measurement results in this spectral band can be caused by the inhomogeneity of the etching when the alloy components are segregated. Additional uncertainty arises when the analyzed image pixel contains a boundary between grains of different phases. This article attempts to use the results of local chemical composition measurements as a source signal for quantitative evaluation of phase composition. For this purpose, quantitative maps of elemental concentration distributions, obtained with a Tescan Mira GMU high-resolution scanning electron microscope in QuantMap mode, were used as input data for the phase composition evaluation of an EN AC 46000 alloy sample. The X-ray microanalysis signal generation area may contain grains of more than one phase. Therefore, evaluation of the phase fractions in areas of individual measurements were calculated by looking for the minimum of the objective function, calculated as the sum of the squares of the deviations of the results of measurements of the concentration of individual elements from the weighted average values of solubilities of these elements in the phases.

7.
Microsc Microanal ; 30(3): 489-500, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38819651

RESUMO

Lab managers and users of scanning electron microscope or electron probe microanalyzer facilities aiming for qualitative or quantitative X-ray analyses require comprehensive, yet flexible documentation structures for their daily work and available reference material, with a complete X-ray data library, a repository of energy- and wavelength-dispersive spectra, and an instrument scheduling mechanism. An online multilaboratory database system available at https://de-ma.ch is presented with the primary goals of providing information on microanalytical reference materials, analytical setups, characteristic X-ray data, and for managing reservation and training requests. This website is designed for multiuser facilities, where experience ranges from beginners to expert users. Registered users will find these tools useful in developing and maintaining high-quality, reproducible, and efficient analyses, whereas lab managers will keep records of their microanalytical reference material database and analytical protocols. The database also serves an educational purpose by (a) providing information on reference materials, (b) encouraging students to select appropriate X-ray lines to analyze, (c) providing analytical setups for point analysis or mapping, (d) identifying unknown X-ray lines, (e) displaying energy- or wavelength-dispersive spectra, and (f) recalculating mineral formula from quantitative wt% analysis results, based on a number of oxygen atoms or cations.

8.
Plant Cell Environ ; 47(9): 3638-3653, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38757412

RESUMO

Salinity tolerance requires coordinated responses encompassing salt exclusion in roots and tissue/cellular compartmentation of salt in leaves. We investigated the possible control points for salt ions transport in roots and tissue tolerance to Na+ and Cl- in leaves of two contrasting mungbean genotypes, salt-tolerant Jade AU and salt-sensitive BARI Mung-6, grown in nonsaline and saline (75 mM NaCl) soil. Cryo-SEM X-ray microanalysis was used to determine concentrations of Na, Cl, K, Ca, Mg, P, and S in various cell types in roots related to the development of apoplastic barriers, and in leaves related to photosynthetic performance. Jade AU exhibited superior salt exclusion by accumulating higher [Na] in the inner cortex, endodermis, and pericycle with reduced [Na] in xylem vessels and accumulating [Cl] in cortical cell vacuoles compared to BARI Mung-6. Jade AU maintained higher [K] in root cells than BARI Mung-6. In leaves, Jade AU maintained lower [Na] and [Cl] in chloroplasts and preferentially accumulated [K] in mesophyll cells than BARI Mung-6, resulting in higher photosynthetic efficiency. Salinity tolerance in Jade AU was associated with shoot Na and Cl exclusion, effective regulation of Na and Cl accumulation in chloroplasts, and maintenance of high K in root and leaf mesophyll cells.


Assuntos
Cloretos , Cloroplastos , Células do Mesofilo , Folhas de Planta , Raízes de Plantas , Potássio , Tolerância ao Sal , Sódio , Vigna , Raízes de Plantas/metabolismo , Raízes de Plantas/fisiologia , Cloroplastos/metabolismo , Sódio/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/fisiologia , Células do Mesofilo/metabolismo , Potássio/metabolismo , Cloretos/metabolismo , Vigna/metabolismo , Vigna/fisiologia , Fotossíntese , Transporte Biológico
9.
Front Psychol ; 15: 1368074, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38629042

RESUMO

The strategies that enable musicians to adapt their behaviors so that they can break through, feel energized, and perform well collectively distinguish what it is to be a self-regulated learner. These strategies range from one's ability to monitor thoughts and actions to being able to navigate and control one's emotions, especially when feeling frustrated or anxious. Given the challenges of the music profession, it becomes imperative for teachers to equip their students with the necessary skills to self-regulate their own actions, feelings, and thinking so that they are eventually able to cope with the demands required of a contemporary professional musical career. In this study, we focused on the self-regulatory engagement of four master's level cellists who were enrolled in a prominent European higher music education institution. Our data comprised self-regulated learning-based diary-reports that describes the students' practice of self-chosen, especially demanding passages as they prepared for a public recital. Results depict differences between the musicians according to the efficiency of their practice leading up to a formal public recital.

10.
Materials (Basel) ; 17(8)2024 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-38673099

RESUMO

Alite-ye'elimite-belite-ferrite cement (AYBFC) integrates the advantages of calcium sulfoaluminate cement and Portland cement, but its ultra-early strength needs to be further improved when applied to rush repair and construction works. In this study, the ultra-early strength of AYBFC was improved using lithium carbonate (Li2CO3) and superplasticizer. The results showed that an appropriate amount of Li2CO3 could significantly improve the ultra-early strength of AYBFC, since it was capable of promoting the hydration reaction of AYBFC. After polycarboxylate superplasticizer was doped on this basis, the ultra-early compressive strength of AYBFC was further improved. This was because the superplasticizer could markedly enhance the matrix compactness despite its inhibitory effect on the hydration reaction of cement and the generation of hydration products.

11.
Plants (Basel) ; 13(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38498536

RESUMO

Maydis leaf blight (MLB), caused by the necrotrophic fungus Bipolaris maydis, has caused considerable yield losses in maize production. The hypothesis that maize plants with higher foliar silicon (Si) concentration can be more resistant against MLB was investigated in this study. This goal was achieved through an in-depth analysis of the photosynthetic apparatus (parameters of leaf gas exchange chlorophyll (Chl) a fluorescence and photosynthetic pigments) changes in activities of defense and antioxidative enzymes in leaves of maize plants with (+Si; 2 mM) and without (-Si; 0 mM) Si supplied, as well as challenged and not with B. maydis. The +Si plants showed reduced MLB symptoms (smaller lesions and lower disease severity) due to higher foliar Si concentration and less production of malondialdehyde, hydrogen peroxide, and radical anion superoxide compared to -Si plants. Higher values for leaf gas exchange (rate of net CO2 assimilation, stomatal conductance to water vapor, and transpiration rate) and Chl a fluorescence (variable-to-maximum Chl a fluorescence ratio, photochemical yield, and yield for dissipation by downregulation) parameters along with preserved pool of chlorophyll a+b and carotenoids were noticed for infected +Si plants compared to infected -Si plants. Activities of defense (chitinase, ß-1,3-glucanase, phenylalanine ammonia-lyase, polyphenoloxidase, peroxidase, and lipoxygenase) and antioxidative (ascorbate peroxidase, catalase, superoxide dismutase, and glutathione reductase) enzymes were higher for infected +Si plants compared to infected -Si plants. Collectively, this study highlights the importance of using Si to boost maize resistance against MLB considering the more operative defense reactions and the robustness of the antioxidative metabolism of plants along with the preservation of their photosynthetic apparatus.

12.
Anal Chim Acta ; 1292: 342254, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38309854

RESUMO

BACKGROUND: Driven by emission regulations, the technology of emission control catalysts has been under increasing need for development. Understanding the deactivation mechanism of aged or spent automobile exhaust catalysts is the key to extending their service lifetime. However, the lack of comprehensive microstructural characterization results in an incomplete understanding of their physicochemical properties. Deactivation mechanism of automobile exhaust catalysts is a considerably complex phenomenon, it can be classified into three groups based on its origin: thermal sintering, chemical poisoning and mechanical deactivation. RESULTS: In this study, an aged high-mileage automobile exhaust catalyst with Pd and Rh active phases supported on a cerium zirconium oxide doped alumina coating on cordierite was analysed; six consecutive monolithic blocks along the inlet to the outlet of the aged catalyst were extracted, and the corresponding metallographic samples were fabricated using the vacuum impregnation resin method. The purpose of this study was to accurately characterize the different regions of the monolith via electron probe microanalysis and to infer potential causes of catalyst deactivation. Two major causes of deactivation were found: (1) aggregation and alloying of precious-metal particles caused by thermal sintering and (2) chemical poisoning caused by sulphur and phosphorus. Other mechanisms, such as mechanical degradation, which mainly manifests as the loss or wear of the washed coating, were also found to be involved in deactivation. Additionally, the catalytic activity tests showed a considerable decrease in the aged catalyst. The poison concentration trends in the washcoat indicated that P is detrimental to CO oxidation, while S accumulation affects propane oxidation. SIGNIFICANCE: This analysis method can be of substantial practical significance in developing advanced washcoat materials. Meanwhile, it has great potential in the washcoat analysis of honeycomb-shaped monolithic catalyst, such as natural gas catalyst, diesel vehicle oxidation catalyst and other honeycomb catalysts applied in chemical industry.

13.
Astrobiology ; 24(2): 190-226, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38393828

RESUMO

The NASA Mars 2020 Perseverance rover is actively exploring Jezero crater to conduct analyses on igneous and sedimentary rock targets from outcrops located on the crater floor (Máaz and Séítah formations) and from the delta deposits, respectively. The rock samples collected during this mission will be recovered during the Mars Sample Return mission, which plans to bring samples back to Earth in the 2030s to conduct in-depth studies using sophisticated laboratory instrumentation. Some of these samples may contain traces of ancient martian life that may be particularly difficult to detect and characterize because of their morphological simplicity and subtle biogeochemical expressions. Using the volcanic sediments of the 3.45 Ga Kitty's Gap Chert (Pilbara, Australia), containing putative early life forms (chemolithotrophs) and considered as astrobiological analogues for potential early Mars organisms, we document the steps required to demonstrate the syngenicity and biogenicity of such biosignatures using multiple complementary analytical techniques to provide information at different scales of observation. These include sedimentological, petrological, mineralogical, and geochemical analyses to demonstrate macro- to microscale habitability. New approaches, some unavailable at the time of the original description of these features, are used to verify the syngenicity and biogenicity of the purported fossil chemolithotrophs. The combination of elemental (proton-induced X-ray emission spectrometry) and molecular (deep-ultraviolet and Fourier transform infrared) analyses of rock slabs, thin sections, and focused ion beam sections reveals that the carbonaceous matter present in the samples is enriched in trace metals (e.g., V, Cr, Fe, Co) and is associated with aromatic and aliphatic molecules, which strongly support its biological origin. Transmission electron microscopy observations of the carbonaceous matter documented an amorphous nanostructure interpreted to correspond to the degraded remains of microorganisms and their by-products (extracellular polymeric substances, filaments…). Nevertheless, a small fraction of carbonaceous particles has signatures that are more metamorphosed. They probably represent either reworked detrital biological or abiotic fragments of mantle origin. This study serves as an example of the analytical protocol that would be needed to optimize the detection of fossil traces of life in martian rocks.


Assuntos
Meio Ambiente Extraterreno , Marte , Meio Ambiente Extraterreno/química , Sedimentos Geológicos/química , Exobiologia , Fósseis
14.
Microsc Microanal ; 30(3): 607-618, 2024 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-38323481

RESUMO

Manipulation of host plant physiology by leaf-galling insects is a multifaceted process. Among fundamental knowledge gaps surrounding this scientifically intriguing phenomenon is the appropriation of plant mineral nutrients and moisture for galling advantage. Small, soluble mineral ions and watery cell contents in dense gall tissues risk disruption during routine sample preparations. In this study, an X-ray microanalysis was applied to investigate gall mineral nutrition. Morphologically diverse leaf galls were sampled from three Australian rainforest tree species. Using cryo-analytical scanning electron microscopy, real-time X-ray analytical maps of cellular mineral nutrients and water were integrated with anatomical images of gall and leaf cross-sectional surfaces. A comparison of host-leaf and gall anatomies bore direct evidence of drastic changes to leaf cells through the galling process. Distinct "wet" and "dry" regions within galls were anatomically and/or chemically differentiated, suggesting specific functionality. "Wet" regions comprising hydrated cells including soft gall-cavity linings where larvae are known to feed contained soluble plant mineral nutrients, while C-rich "dry" tissues largely devoid of mineral nutrients likely contribute structural support. Mapping immobile nutrients such as Mn may provide a means of "matching" specific gall cell types to those in ungalled host-leaf tissues. The findings here provided otherwise inaccessible insights into leaf-gall mineral nutrition.


Assuntos
Insetos , Minerais , Folhas de Planta , Tumores de Planta , Folhas de Planta/química , Animais , Minerais/análise , Minerais/metabolismo , Tumores de Planta/parasitologia , Insetos/fisiologia , Microanálise por Sonda Eletrônica , Microscopia Eletrônica de Varredura , Austrália , Temperatura Baixa , Árvores
15.
Environ Monit Assess ; 196(2): 181, 2024 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-38246977

RESUMO

Toenails are a common monitoring tool for arsenic exposure, but the risk of external contamination of toenails has cast doubt on its usefulness. The main objective of this study is to investigate the micro-distribution of arsenic through the dorsoventral plane of nail clippings to understand endogenous vs exogenous sources. We used laser-ablation inductively coupled plasma mass spectrometry to measure arsenic through a dorsoventral cross-section of the nail plate collected from reference (N = 17) and exposed individuals (N = 35). Our main results showed (1) bulk toenail concentrations measured using ICP-MS in this study ranged from 0.54 to 4.35 µg/g; (2) there was a double-hump pattern in arsenic concentrations, i.e., dorsal and ventral layers had higher arsenic than the inner layer; (3) the double-hump was more pronounced in the exposed group (ventral: 6.25 µg/g; inner: 0.75 µg/g; dorsal: 0.95 µg/g) than the reference group (ventral: 0.58 µg/g; inner: 0.15 µg/g; dorsal: 0.29 µg/g) on average; (4) the distribution was, in part, associated with different binding affinity of nail layers (i.e., ventral > dorsal > inner); (5) most individuals in the higher exposure group showed > 25% contamination in ventral and dorsal nail layers; and (6) there were no statistically significant correlations between LA-ICP-MS arsenic with either bulk toenail arsenic or urine arsenic from the same individuals. Our results on micro-distribution and binding affinity provide insight into the impact of external contamination on arsenic concentrations and show how LA-ICP-MS can access the protected inner nail layer to provide a more accurate result.


Assuntos
Arsênio , Terapia a Laser , Humanos , Monitoramento Biológico , Unhas , Monitoramento Ambiental , Espectrometria de Massas
16.
Am J Ind Med ; 67(3): 179-199, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38265196

RESUMO

BACKGROUND: With increasing reports of accelerated and acute silicosis, PMF, and autoimmune disease among coal miners and silica-exposed countertop workers, we present previously incompletely-described pulmonary pathology of accelerated silicosis and correlations with mineralogy, radiography, and disease progression in 46 Texas oilfield pipe sandblasters who were biopsied between 1988 and 1995. METHODS: Worker examinations included pulmonary function tests, chest X-ray (CXR), high-resolution computed tomography (HRCT), and Gallium-67 scans. Quantitative mineralogic analysis of pulmonary parenchymal burden of silica, silicates, and metal particles used scanning electron microscopy with energy dispersive x-ray spectroscopy (SEM EDS). RESULTS: Workers had clinical deterioration after <10 years exposure in dusty workplaces. Although initial CXR was normal in 54%, Gallium-67 scans were positive in 68% of those with normal CXR, indicating pulmonary inflammation. The histology of accelerated silicosis is diffuse interstitial infiltration of macrophages filled with weakly birefringent particles with or without silicotic nodules or alveolar proteinosis. Lung silica concentrations were among the highest in our database, showing a dose-response relationship with CXR, HRCT, and pathologic changes (macrophages, fibrosis, and silicotic nodules). Radiographic scores and diffusing capacity worsened during observation. Silica exposure was intensified, patients presented younger, with shorter exposure, more severe clinical abnormalities, higher lung particle burdens, and more rapid progression in a subset of patients exposed to recycled blasting sand. CONCLUSIONS: Accelerated silicosis may present with a normal CXR despite significant histopathology. Multivariable analyses showed silica, and not other particles, is the driver of observed radiologic, physiologic, and histologic outcomes. Eliminating this preventable disease requires higher physician, public health, and societal awareness.


Assuntos
Radioisótopos de Gálio , Exposição Ocupacional , Silicose , Humanos , Silicose/diagnóstico por imagem , Silicose/epidemiologia , Silicose/etiologia , Pulmão/patologia , Dióxido de Silício/efeitos adversos , Silicatos/efeitos adversos , Exposição Ocupacional/efeitos adversos
17.
Infant Behav Dev ; 74: 101920, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38237345

RESUMO

Although a considerable literature documents associations between early mother-infant interaction and cognitive outcomes in the first years of life, few studies examine the contributions of contingently coordinated mother-infant interaction to infant cognitive development. This study examined associations between the temporal dynamics of the contingent coordination of mother-infant face-to-face interaction at 4 months and cognitive performance on the Bayley Scales of Infant Development at age one year in a sample of (N = 100) Latina mother-infant pairs. Split-screen videotaped interactions were coded on a one second time base for the communication modalities of infant and mother gaze and facial affect, infant vocal affect, and mother touch. Multi-level time-series models evaluated self- and interactive contingent processes in these modalities and revealed 4-month patterns of interaction associated with higher one-year cognitive performance, not identified in prior studies. Infant and mother self-contingency, the moment-to-moment probability that the individual's prior behavior predicts the individual's future behavior, was the most robust measure associated with infant cognitive performance. Self-contingency findings showed that more varying infant behavior was optimal for higher infant cognitive performance, namely, greater modulation of negative affect; more stable maternal behavior was optimal for higher infant cognitive performance, namely, greater likelihood of sustaining positive facial affect. Although interactive contingency findings were sparse, they showed that, when mothers looked away, or dampened their faces to interest or mild negative facial affect, infants with higher 12-month cognitive performance were less likely to show negative vocal affect. We suggest that infant ability to modulate negative affect, and maternal ability to sustain positive affect, may be mutually reinforcing, together creating a dyadic climate that is associated with more optimal infant cognitive development.


Assuntos
Comportamento Materno , Mães , Feminino , Lactente , Criança , Humanos , Mães/psicologia , Relações Mãe-Filho/psicologia , Comunicação , Cognição , Comportamento do Lactente/psicologia
18.
Biol Trace Elem Res ; 202(4): 1644-1655, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37495827

RESUMO

This study evaluated the effect of prepubertal arsenic exposure in the liver and kidney of pubescent rats and their reversibility 30 days after arsenic withdrawal. Male pups of Wistar rats (21 days old) were divided into two groups (n = 20/group): control animals received filtered water, and exposed rats received 10 mg L-1 arsenic from postnatal day (PND) 21 to PND 51. The liver and kidney of 52 days old rats (n = 10/group) were examined to investigate the effects of arsenic on micromineral content, antioxidant enzyme activity, histology, and biochemistry parameters. The other animals were kept alive under free arsenic conditions until 82 days old and further analyzed by the same parameters. Our results revealed that 52-day-old rats increased arsenic content in their liver and arsenic and manganese in their kidney. In those animals, glycogen and zinc content and catalase activity were reduced in the liver, and the selenium content decreased in the kidney. Thirty days later, arsenic reduced the manganese and iron content and SOD and CAT activity in the liver of 82-day-old rats previously exposed to arsenic, while glycogen and selenium content decreased in their kidney. In contrast, PND 82 rats exhibited higher retention of copper in the liver, an increase in iron and copper content, and CAT and GST activity in the kidney. Significant histological alterations of liver and kidney tissues were not observed in rats of both ages. We conclude that arsenic-induced toxicity could alter differently the oxidative status and balance of trace elements in pubertal and adult rats, demonstrating that the metalloid can cause effects in adulthood.


Assuntos
Arsênio , Selênio , Ratos , Masculino , Animais , Arsênio/metabolismo , Cobre/farmacologia , Ratos Wistar , Selênio/farmacologia , Selênio/metabolismo , Manganês/farmacologia , Catalase/metabolismo , Antioxidantes/metabolismo , Fígado/metabolismo , Rim/metabolismo , Ferro/metabolismo , Estresse Oxidativo , Glicogênio/metabolismo
19.
J Microsc ; 294(2): 66-74, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37706543

RESUMO

Within the global trend to valorise various mineral wastes as substituents in Portland cement clinker raw feed, mining wastes are promising candidates. However, they might still contain high levels of metallic elements. Their fate in the kiln is not always understood as well as their incorporation within the various clinker's phases. This is especially the case for antimony. Its in situ microanalysis by the means of energy-dispersive spectroscopy is tricky since several of its L lines (Lα1 = 3604,72 eV, Lα2 = 3595,32 eV) overlap with calcium lines (Kα1 = 3691,68 eV, Kα2 = 3688,09 eV). Hence, at low concentrations, it is not possible to visualise its characteristics peaks. Increasing the counting rate by increasing the acceleration current results in the generation of spurious sum peaks, rendering the analysis not viable. Wavelength dispersive spectroscopy (i.e. electron microprobe) allows a better spectral resolution and quantification of Sb in the clinker phases. In a Portland cement clinker doped with 1% of Sb-bearing mining waste, the Sb2O3 content in belite and alite is in the 0.2-0.4 wt.% range as well as for C3A; in C4AF the content is higher, from 1.4 wt.% to 2 wt.%. However, there are microstructural evidence that Sb forms blebs from less than 1 µm in diameter up to 10 µm, included in calcium silicates. Hence, its incorporation in the lattice of calcium silicates is dubious. However, for ferrites and aluminates there is no microstructural evidence for remaining Sb-bearing phases, suggesting a direct incorporation in crystal lattices.

20.
J Chromatogr A ; 1713: 464511, 2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38007841

RESUMO

Protein tyrosine phosphatase receptor type O (PTPRO) plays an important role in inflammation-related pathways and has become an emerging drug target. In this study, we developed an in-line capillary electrophoresis (CE) method for the investigation of the enzymatic activity of PTPRO, which was based on electrophoretically mediated microanalysis (EMMA). After a thorough method validation of the optimized conditions, this protocol was successfully employed to determine the kinetics of PTPRO as well as the half-maximal inhibitory concentration (IC50) of two typical PTPRO inhibitors. The final results were consistent with the values obtained through classical ultraviolet-visible (UV-vis) spectrophotometry. Our new method exhibited improved accuracy and reduced consumption, avoiding the disadvantages of traditional methods. This work provides a new strategy for PTPRO enzyme kinetic studies as well as inhibitory activity determination through capillary electrophoresis for the first time.


Assuntos
Eletroforese Capilar , Ensaios de Triagem em Larga Escala , Cinética , Eletroforese Capilar/métodos , Inibidores Enzimáticos/farmacologia , Proteínas Tirosina Fosfatases
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