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1.
Materials (Basel) ; 17(8)2024 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-38673228

RESUMO

Diamonds produced using chemical vapor deposition (CVD) have found many applications in various fields of science and technology. Many applications involve polycrystalline CVD diamond films of micron thicknesses. However, a variety of optical, thermal, mechanical, and radiation sensing applications require more bulky CVD diamond samples. We report the results of a magnetic resonance and structural study of a thick, sizable polycrystalline CVD diamond disc, both as-prepared and treated with e-beam irradiation/high-temperature annealing, as well as gamma irradiation. The combination of various magnetic resonance techniques reveals and enables the attribution of a plentiful collection of paramagnetic defects of doublet and triplet spin origin. Analysis of spectra, electron, and nuclear spin relaxation, as well as nuclear spin diffusion, supports the conclusion of significant macro- and micro-inhomogeneities in the distribution of nitrogen-related defects.

2.
J Biol Chem ; 300(3): 105676, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38278326

RESUMO

Infectious diseases are one of the world's leading causes of morbidity. Their rapid spread emphasizes the need for accurate and fast diagnostic methods for large-scale screening. Here, we describe a robust method for the detection of pathogens based on microscale thermophoresis (MST). The method involves the hybridization of a fluorescently labeled DNA probe to a target RNA and the assessment of thermophoretic migration of the resulting complex in solution within a 2 to 30-time window. We found that the thermophoretic migration of the nucleic acid-based probes is primarily determined by the fluorescent molecule used, rather than the nucleic acid sequence of the probe. Furthermore, a panel of uniformly labeled probes that bind to the same target RNA yields a more responsive detection pattern than a single probe, and moreover, can be used for the detection of specific pathogen variants. In addition, intercalating agents (ICA) can be used to alter migration directionality to improve detection sensitivity and resolving power by several orders of magnitude. We show that this approach can rapidly diagnose viral SARS-CoV2, influenza H1N1, artificial pathogen targets, and bacterial infections. Furthermore, it can be used for anti-microbial resistance testing within 2 h, demonstrating its diagnostic potential for early pathogen detection.


Assuntos
Ensaios de Triagem em Larga Escala , Técnicas Microbiológicas , Técnicas de Diagnóstico Molecular , Hibridização de Ácido Nucleico , RNA , Sondas de DNA , Vírus da Influenza A Subtipo H1N1/genética , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Técnicas de Diagnóstico Molecular/métodos , Técnicas de Diagnóstico Molecular/normas , Técnicas Microbiológicas/métodos , Técnicas Microbiológicas/normas , Ensaios de Triagem em Larga Escala/métodos , Ensaios de Triagem em Larga Escala/normas , RNA/análise , SARS-CoV-2/genética , SARS-CoV-2/isolamento & purificação , Viroses/diagnóstico , Infecções Bacterianas/diagnóstico , Linhagem Celular Tumoral , Humanos
3.
ACS Omega ; 8(49): 46608-46613, 2023 Dec 12.
Artigo em Inglês | MEDLINE | ID: mdl-38107895

RESUMO

The increased global demand for energy and the environmental concerns associated with fossil fuels highlight the need for alternative approaches. Fossil fuel combustion, particularly coal and oil shale, contributes to greenhouse gas emissions and generates large amounts of ash residues, posing environmental challenges. This study focuses on the potential of thermal treatment to upgrade oil shale bottom ash (OSBA) for use as a cement replacement in concrete, addressing both the economic viability of oil shale combustion and the environmental issue of ash waste management. The findings have significant implications for improving the economics and environmental sustainability of oil shale combustion in construction. By enhancing the properties of OSBA, this study contributes to the advancement of greener energy solutions and waste management practices in the energy and construction sectors.

4.
Biology (Basel) ; 12(11)2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37997987

RESUMO

Background: Hemophilia A and B induce recurrent bleeding episodes, mainly in skeletal muscles and joints that are in intermittent motion. We have previously demonstrated that intermittent motion contributes to increased degradation of factors VIII and IX. Objectives: Given that calcium ions are known to enhance factor VIII-von Willebrand factor (vWF) interaction, the present study has investigated the role of these ions on factors VIII and IX in the condition of motion. Methods: The effects of calcium ions were assessed using purified proteins via Western blot, factor VIII activity, immunocytochemistry, and in Institute of Cancer Research (ICR) mice with no specific genetic background. Results: Calcium was found to prevent degradation of plasma-derived factor VIII but not that of factor IX, during intermittent motion. Calcium levels in the microcirculation of mouse striated muscles were elevated following movement, enabling prevention of factor VIII degradation in normal physiology. Calcium supplementation in drinking water increased factor VIII levels in blood and striated muscles of ICR mice during movement. Conclusions: calcium ions decrease factor VIII degradation in the condition of motion. Further research on the impact of calcium salt oral supplementation on hemophilia patients is warranted.

5.
Aging (Albany NY) ; 15(16): 7922-7932, 2023 08 28.
Artigo em Inglês | MEDLINE | ID: mdl-37639552

RESUMO

Copy number variations (CNV) are a major contributor to genome variability and have been linked to aging and other degradable phenotypes such as pregnancy physiology. To demonstrate how pregnancy can be used as a model of aging, we used CNVs from pregnant mice. Candidate CNVs were selected by applying case-control analysis in human centenarians compared with control groups. These CNVs were aligned with the mouse genome and their copy variation was assessed using qRT-PCR in liver and blood tissue samples from pregnant mice throughout pregnancy (baseline; first, second, and third trimester; post-partum). Eight of the ten selected CNVs demonstrated a significant decline/increase trend throughout the pregnancy followed by opposite direction soon after delivery in the liver and blood of the mouse tissues. Furthermore, significant differential expression was detected among the candidate CNVs' close vicinity genes (APA2A, LSS, RBDHF1, PLAAT1, and SCL17A2), but not in the WSCD2 gene. Establishing a genetic link between longevity and pregnancy is a significant step toward implementing the pregnancy process as a model for aging. These results in pregnant mice highlight the mechanism and similarities between pregnancy and aging. Investigating the mechanisms that cause such rejuvenation after labor could change our aging treatment paradigm.


Assuntos
Envelhecimento , Variações do Número de Cópias de DNA , Idoso de 80 Anos ou mais , Humanos , Feminino , Gravidez , Animais , Camundongos , Longevidade , Fígado , Aciltransferases
6.
Int J Mol Sci ; 24(13)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37445906

RESUMO

The most common clinical presentation of hemophilia A and hemophilia B is bleeding in large joints and striated muscles. It is unclear why bleeding has a predilection to affect joints and muscles. As muscles and joints are involved in intermittent movement, we explored whether this phenomenon could be associated with an impact on factor VIII and IX levels. Purified proteins and a mouse model were assessed using coagulation assays, Western blot analysis and immuno-staining. Movement caused an increase in thrombin activity and a decrease in factor VIII and factor IX activity. The decrease in factor VIII activity was more significant in the presence of thrombin and during movement. Under movement condition, sodium ions appeared to enhance the activity of thrombin that resulted in decreased factor VIII activity. Unlike factor VIII, the reduction in factor IX levels in the movement condition was thrombin-independent. High factor VIII levels were found to protect factor IX from degradation and vice versa. In mice that were in movement, factor VIII and IX levels decreased in the microcirculation of the muscle tissue compared with other tissues and to the muscle tissue at rest. Movement had no effect on von Willebrand factor levels. Movement induces reduction in factor VIII and IX levels. It enables an increase in the binding of sodium ions to thrombin leading to enhanced thrombin activity and augmented degradation of factor VIII. These data suggest a potential mechanism underlying the tendency of hemophilia patients to bleed in muscles and joints.


Assuntos
Hemofilia A , Hemostáticos , Animais , Camundongos , Fator VIII/metabolismo , Fator IX/metabolismo , Trombina , Hemofilia A/metabolismo , Hemorragia
7.
ACS Omega ; 8(24): 21506-21513, 2023 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-37360483

RESUMO

Oil shale is a rock that contains organic matter in a concentration that allows it to be used as an energy source. As a result of the shale combustion process, large amounts of two types of ash are formed: fly ash (∼10%) and bottom ash (∼90%). At present, in Israel, only fly oil shale ash is used, which constitutes a minority of the oil shale burn products, whereas bottom oil shale ash is accumulated as waste. Bottom ash contains a high percentage of calcium in the form of anhydrite (CaSO4) and calcite (CaCO3). Thus, it can be used to neutralize acidic waste and to fix trace elements. This study examined the process of scrubbing the acid waste by the ash, its characterization pre- and post-upgrade treatment, to test its suitability as a partial substitute for aggregates, natural sand, and cement in concrete mixtures. In the current study, we compared the chemical and physical characterization of oil shale bottom ash before and after upgrading the ash via chemical treatment. In addition, its utilization as a scrubbing reagent for acidic wastes from the phosphate industry was studied.

8.
Front Neurosci ; 16: 897005, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35928013

RESUMO

The modern lifestyle requires less physical activity and skills during our daily routine, leading to multiple pathologies related to physical disabilities and energy accessibility. Thus, exploring the mechanisms underlying the metabolic regulation of exercise is crucial. Here, we characterized the effect of forced and voluntary endurance exercises on three key metabolic signaling pathways, sirtuins, AMPK, and mTOR, across several metabolic tissues in mice: brain, muscles, and liver. Both voluntary and forced exercises induced AMPK with higher intensity in the first. The comparison between those metabolic tissues revealed that the hypothalamus and the hippocampus, two brain parts, showed different metabolic signaling activities. Strikingly, despite the major differences in the physiology of muscles and hypothalamic tissues, the hypothalamus replicates the metabolic response of the muscle in response to physical exercise. Specifically, muscles and hypothalamic tissues showed an increase and a decrease in AMPK and mTOR signaling, respectively. Overall, this study reveals new insight into the relation between the hypothalamus and muscles, which enhances the coordination within the muscle-brain axis and potentially improves the systemic response to physical activity performance and delaying health inactivity disorders.

9.
Phys Chem Chem Phys ; 24(19): 11696-11703, 2022 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-35506456

RESUMO

The modification of nitrogen-contaminated diamonds into color-enhanced diamonds is usually achieved by irradiation and thermal treatment (annealing). These treatments affect nitrogen contamination chemical bonding, vacancy concentration, and atom orientation centers in the diamond lattice. In this study, natural diamonds were subjected to irradiation and thermal annealing color enhancement treatments to produce green, blue, and yellow fancy diamonds. The study followed the changes that occur during treatment relying on visual assessment, fluorescence, UV-vis, FTIR, and EPR spectroscopy to characterize paramagnetic centers. The results indicated that diamonds containing high levels of nitrogen contamination presented a relatively high carbon-centered radical concentration. Two paramagnetic groups with different g-values were found, namely, low g-value centers of 2.0017-2.0027 and high g-value centers of 2.0028-2.0035. It is suggested that the 2.0017-2.0022 centers correlate with blue centers, whereas the 2.0023-2.0027 centers correlate with yellow centers. It was also found that thermal treatment was required to produce blue and yellow fancy diamonds, whereas no such treatment was needed to produce green diamonds.


Assuntos
Carbono , Diamante , Diamante/química , Espectroscopia de Ressonância de Spin Eletrônica , Nitrogênio/química
10.
ACS Omega ; 7(2): 1893-1907, 2022 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-35071880

RESUMO

Coal is at present a major fuel source for power generation worldwide and will remain as such in the near future. The most important property of coal that determines its price is its calorific value. However, volatiles, ash, and moisture content are also very important properties needed for the quality control (QC) of the coal used to maintain an optimal operation of coal combustion in a boiler. The determination of these properties is carried out via well-established ASTM/DIN methods, which are slow and time-consuming. This study uses combined thermogravimetric analysis (TGA)/differential thermal calorimetry (DSC) instrumentation as a tool to evaluate the reactivity patterns of the aliphatic versus aromatic content of coals, which is correlated to the volatile content of coals. Two coals, bituminous (American Baily Pittsburgh No. 6) used in Israeli utilities and lignite (brown coal Hambach) used in German power plants, have been investigated in this study. The results show that the combined TG/DSC method can provide a much better understanding of the chemical reactivity of coals in the combustion process.

11.
Nat Commun ; 12(1): 7185, 2021 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-34893620

RESUMO

The prevalent m6Am mRNA cap modification was recently identified as a valid target for removal by the human obesity gene FTO along with the previously established m6A mRNA modification. However, the deposition and dynamics of m6Am in regulating obesity are unknown. Here, we investigate the liver m6A/m methylomes in mice fed on a high fat Western-diet and in ob/ob mice. We find that FTO levels are elevated in fat mice, and that genes which lost m6Am marking under obesity are overly downregulated, including the two fatty-acid-binding proteins FABP2, and FABP5. Furthermore, the cellular perturbation of FTO correspondingly affect protein levels of its targets. Notably, generally m6Am- but not m6A-methylated genes, are found to be highly enriched in metabolic processes. Finally, we deplete all m6A background via Mettl3 knockout, and unequivocally uncover the association of m6Am methylation with increased mRNA stability, translation efficiency, and higher protein expression. Together, these results strongly implicate a dynamic role for m6Am in obesity-related translation regulation.


Assuntos
Adenosina/análogos & derivados , Adenosina/metabolismo , Obesidade/metabolismo , Dioxigenase FTO Dependente de alfa-Cetoglutarato/metabolismo , Animais , Dieta Ocidental , Epigenômica , Proteínas de Ligação a Ácido Graxo/metabolismo , Masculino , Metilação , Camundongos , Camundongos Endogâmicos C57BL , Proteínas de Neoplasias , Estabilidade de RNA , RNA Mensageiro/metabolismo
12.
Materials (Basel) ; 14(24)2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34947315

RESUMO

Diamonds contain carbon paramagnetic centers (stable carbon radicals) in small concentrations (at the level of ~1 × 1012 spins/mg) that can help in elucidating the structure of the nitrogen atoms' contaminants in the diamond crystal. All diamonds that undergo polishing are exposed to high temperatures, owing to the friction force during the polishing process, which may affect the carbon-centered radicals' concentration and structure. The temperature is increased appreciably; consequently, the black body radiation in the visible range turns orange. During polishing, diamonds emit an orange light (at a wavelength of about 600 nm) that is typical of a black body temperature of 900 °C or higher. Other processes in which color-enhanced diamonds are exposed to high temperatures are thermal treatments or the high-pressure, high-temperature (HPHT) process in which the brown color (resulting from plastic deformation) is bleached. The aim of the study was to examine how thermal treatment and polishing influence the paramagnetic centers in the diamond. For this purpose, four rough diamonds were studied: two underwent a polishing process, and the other two were thermally treated at 650 °C and 1000 °C. The diamonds were analyzed pre- and post-treatment by EPR (Electron Paramagnetic resonance), FTIR (Fourier transform infrared, fluorescence, and their visual appearance. The results indicate that the polishing process results in much more than just thermal heating the paramagnetic centers.

13.
ACS Omega ; 6(49): 33428-33435, 2021 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-34926892

RESUMO

Coal is intensively used worldwide as a main fuel source. However, it may undergo oxidation processes [i.e., low-temperature oxidation (LTO)] when stored under an air atmosphere in piles post-mining at low temperatures ranging from 300 to 425 K, specifically, a surface gas/solid reaction with molecular oxygen. Therefore, it is of major importance to prevent or appreciably slow down such reactions, which result in a loss in the energy content (calorific value) of coal. Previously, we showed that radicals are formed during the LTO process. In this work, the dependence of radical formation on coal rank as a function of heating (temperature) and the presence of oxygen gas were studied using electron paramagnetic resonance spectroscopy. It was shown that lignite coals are more sensitive than bituminous coals to the atmospheric environment (i.e., molecular oxygen and nitrogen content) and to temperature, as reflected by the formation of surface carbon-centered radicals. Moreover, this is the first publication showing the effects of LTO on micro- and macro-pores by assessing how these structures affect O2 diffusion. The LTO process blocks the micro-pores, such that radicals form mainly at the surface of the coal macromolecules, in both bituminous and lignite coals.

14.
Sci Rep ; 11(1): 6815, 2021 03 25.
Artigo em Inglês | MEDLINE | ID: mdl-33767347

RESUMO

The intervertebral disc's (IVD) annulus fibrosus (AF) retains the hydrostatic pressure of the nucleus pulposus (NP), controls the range of motion, and maintains the integrity of the motion segment. The microstructure of the AF is not yet fully understood and quantitative characterization is lacking, leaving a caveat in modern medicine's ability to prevent and treat disc failure (e.g., disc herniation). In this study, we show a reconstruction of the 3D microstructure of the fibers that constitute the AF via MRI diffusion tensor imaging (DTI) followed by fiber tracking. A quantitative analysis presents an anisotropic structure with significant architectural differences among the annuli along the width of the fibrous belt. These findings indicate that the outer annuli's construction reinforces the IVD while providing a sufficient degree of motion. Our findings also suggest an increased role of the outer annuli in IVD nourishment.


Assuntos
Anel Fibroso/cirurgia , Imageamento Tridimensional , Degeneração do Disco Intervertebral/diagnóstico , Degeneração do Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/diagnóstico , Deslocamento do Disco Intervertebral/cirurgia , Procedimentos de Cirurgia Plástica , Humanos , Processamento de Imagem Assistida por Computador , Imageamento por Ressonância Magnética/métodos , Microscopia de Força Atômica , Cirurgia Assistida por Computador/métodos
15.
J Phys Chem A ; 125(7): 1436-1446, 2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33566599

RESUMO

The redox chemistry of CeIIIDOTA in cage in carbonate solutions was studied using electrochemistry and radiolysis techniques (continuous radiolysis and pulse radiolysis). Spectroscopic measurements point out that the species present in the solutions at high bicarbonate concentrations are [CeIIIDOTA(CO3)]3- (or less plausible [CeIIIDOTA(HCO3)]2-) with the carbonate (bicarbonate) anion as the ninth ligand versus [CeIIIDOTA(H2O)]- present in the absence of bicarbonate. Electrochemical results show a relatively low increase in the thermodynamic stabilization of the redox couple CeIV/III in the presence of carbonate versus its aqueous analogue. [CeIVDOTA(CO3)]2- and [CeIVDOTA(H2O)], prepared electrochemically, decompose photolytically. However, kept in the dark, both are relatively long lived; [CeIVDOTA(H2O)], though, is orders of magnitude kinetically more stable (a considerably longer half-life). Thus, one concludes that the carbonate species have a different mechanism of decomposition depending also on the presence of dioxygen after its preparation (in deaerated/aerated solutions). The [CeIVDOTA(CO3)]2- species is produced radiolytically by oxidation of the trivalent species by CO3•- with a rate constant, measured using pulse radiolysis, of 3.3 × 105 M-1 s-1. This rate constant is at least 1 order of magnitude smaller than most of the rate constants so far reported for the reaction of CO3•- with transition metal/lanthanide (cerium)/actinide complexes. This result together with the bulkiness of the reactants might suggest an outer-sphere electron transfer rather than the inner-sphere one so far proposed. The lifetime of the tetravalent cerium species obtained radiolytically in the presence of carbonate is shorter than the electrochemical one, suggesting a different conformer involved.

16.
Nat Metab ; 2(11): 1305-1315, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-33139959

RESUMO

A long-standing model holds that stochastic aberrations of transcriptional regulation play a key role in the process of ageing. While transcriptional dysregulation is observed in many cell types in the form of increased cell-to-cell variability, its generality to all cell types remains doubted. Here, we propose a new approach for analysing transcriptional regulation in single-cell RNA sequencing data by focusing on the global coordination between the genes rather than the variability of individual genes or correlations between pairs of genes. Consistently, across very different organisms and cell types, we find a decrease in the gene-to-gene transcriptional coordination in ageing cells. In addition, we find that loss of gene-to-gene transcriptional coordination is associated with high mutational load of a specific, age-related signature and with radiation-induced DNA damage. These observations suggest a general, potentially universal, stochastic attribute of transcriptional dysregulation in ageing.


Assuntos
Envelhecimento/genética , Transcrição Gênica/genética , Animais , Dano ao DNA , Drosophila , Redes Reguladoras de Genes , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Modelos Genéticos , Mutação/genética , Análise de Sequência de RNA , Processos Estocásticos , Transcrição Gênica/efeitos da radiação
17.
ACS Omega ; 5(44): 28500-28509, 2020 Nov 10.
Artigo em Inglês | MEDLINE | ID: mdl-33195900

RESUMO

Coal is one of the major fuels for power generation, and it will continue in this capacity for the next several decades. Two types of coal are mainly used: lignite and bituminous coals. When exposed to air, post-mining, the coal surface undergoes LTO (low-temperature oxidation) at RT-150 °C according to the atmospheric oxygen level. The LTO process decreases the calorific value of the coal, and consequently, different gases are released [mainly carbon oxides (CO, CO2), water vapor, hydrogen (H2), and also some low molecular-weight organic gases (C1-5)]. Some of these gases are toxic and flammable. In extreme cases, fires erupt. The mechanism by which the molecular oxygen oxidizes the coal macromolecule at the temperature range of 30-150 °C (LTO process) is complex and also involves a chain of radical reactions that take place; however, the exact underlying mechanism is not yet clear. The LTO process was studied in detail by simulating the processes occurring in the coal piles by using two coal types: an American Bailey coal, used in Israeli coal-fired utilities and a German Hambach lignite, used in German utilities. The mechanism underlying the LTO process and the radical reactions that are involved are discussed in detail.

18.
Exp Gerontol ; 137: 110952, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32344118

RESUMO

BACKGROUND: Aging is defined as a biological and physical complex process that is characterized by the increase in susceptibility to diseases and eventually death. Aging may occur at different rates between and within species, especially or (it varies) among the long-lived ones. Here, we ask whether this diversity (e.g. aging phenotype) stems from genetic or environmental factors or as a combination between the two (epigenetics). Epigenetics play a central role in controlling changes in gene expression during aging. DNA methylation is the most abundant epigenetic modification among vertebrates and is essential to mammalian development. MATERIALS AND METHODS: In this study, we utilized the HELPtag assay to identify five candidate genes that were significantly hyper- or hypo-methylated across four different age groups in mice. The candidate genes were annotated using ensemble and their expression was further tested in vitro using the murine RAW 264.7 cell line to examine the effect of three environmental stressors (UV radiation, Hypoxia and fasting) on their expression. RNA was extracted at different time points followed by cDNA synthesis. Changes in gene expression were evaluated using qRT-PCR. RESULTS: We show that fasting and UV radiation reduced the viability of RAW264.7 cells. We also found a significant change in three candidate genes' expression levels during fasting (TOP2B, RNF13 and MRPL4). Furthermore, we found a significant change in the four candidate genes' expression levels following UVC treatment (TOP2B, RNF13, PKNOX1 and CREB5) and yet no changes were recorded in hypoxic conditions. CONCLUSION: Our results suggest that the model we used was a fitting model for the assessment of environmental stressors on candidate gene expression. In addition, we established a cellular response to the environment via changes in gene expression.


Assuntos
Metilação de DNA , Epigênese Genética , Envelhecimento/genética , Animais , Epigenômica , Proteínas de Homeodomínio , Camundongos , Fenótipo
19.
Sci Total Environ ; 700: 134444, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31689656

RESUMO

The present study focuses on the geochemistry of large phosphogypsum deposits in Huelva (SW Spain). Phosphogypsum slurry waste from fertiliser production was disposed in large ponds containing aqueous waste (i.e. brines) and exposed to weathering. These evaporation ponds were found to be dynamic environments far from attaining steady state conditions where a number of trace pollutants are subjected to temporal variations in response to changing environmental conditions. Chemical, mineralogical and morphological data were used to improve our understanding on the dynamics of a large number of elements in the phosphogypsum-brine-evaporation deposits system. Weekly sampling of brines over the course of 1 yr indicated a substantial enrichment in potentially harmful elements (e.g. As, Cr, Cu, F, Ni, U, V, Zn) present in time-dependent concentrations. The evaporation deposits formed multi-layered precipitates of chlorides, sulphates, phosphates and fluorides containing a large number of pollutants in readily soluble forms. The precipitation sequence revealed a time-dependent composition reflecting alternating precipitation and re-dissolution processes associated with seasonal changes in the local weather conditions. Concatenation of precipitation/re-dissolution stages was found to progressively enrich the brines in pollutants. These findings were supported by the observations from a tank experiment simulating the phosphogypsum-brine-evaporation deposits system under laboratory conditions. Given the substantially high concentrations of pollutants present in mobile forms in the brine-salt system, actions to abate these compounds should be implemented.

20.
Cell Rep ; 29(12): 4127-4143.e8, 2019 12 17.
Artigo em Inglês | MEDLINE | ID: mdl-31851938

RESUMO

The pro-longevity enzyme SIRT6 regulates various metabolic pathways. Gene expression analyses in SIRT6 heterozygotic mice identify significant decreases in PPARα signaling, known to regulate multiple metabolic pathways. SIRT6 binds PPARα and its response element within promoter regions and activates gene transcription. Sirt6+/- results in significantly reduced PPARα-induced ß-oxidation and its metabolites and reduced alanine and lactate levels, while inducing pyruvate oxidation. Reciprocally, starved SIRT6 transgenic mice show increased pyruvate, acetylcarnitine, and glycerol levels and significantly induce ß-oxidation genes in a PPARα-dependent manner. Furthermore, SIRT6 mediates PPARα inhibition of SREBP-dependent cholesterol and triglyceride synthesis. Mechanistically, SIRT6 binds PPARα coactivator NCOA2 and decreases liver NCOA2 K780 acetylation, which stimulates its activation of PPARα in a SIRT6-dependent manner. These coordinated SIRT6 activities lead to regulation of whole-body respiratory exchange ratio and liver fat content, revealing the interactions whereby SIRT6 synchronizes various metabolic pathways, and suggest a mechanism by which SIRT6 maintains healthy liver.


Assuntos
Fígado/metabolismo , PPAR alfa/metabolismo , Sirtuínas/metabolismo , Acetilação , Animais , Western Blotting , Células Cultivadas , Células HEK293 , Humanos , Imunoprecipitação , Masculino , Camundongos , Camundongos Transgênicos , Coativador 2 de Receptor Nuclear/genética , Coativador 2 de Receptor Nuclear/metabolismo , Oxirredução , PPAR alfa/genética , Sirtuínas/genética
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