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Understanding heating and cooling mechanisms in mesoscopic superconductor-semiconductor devices is crucial for their application in quantum technologies. Owing to their poor thermal conductivity, heating effects can drive superconducting-to-normal transitions even at low bias, observed as sharp conductance dips through the loss of Andreev excess currents. Tracking such dips across magnetic field, cryostat temperature, and applied microwave power allows us to uncover cooling bottlenecks in different parts of a device. By applying this "Joule spectroscopy" technique, we analyze heat dissipation in devices based on InAs-Al nanowires and reveal that cooling of superconducting islands is limited by the rather inefficient electron-phonon coupling, as opposed to grounded superconductors that primarily cool by quasiparticle diffusion. We show that powers as low as 50-150 pW are able to suppress superconductivity on the islands. Applied microwaves lead to similar heating effects but are affected by the interplay of the microwave frequency and the effective electron-phonon relaxation time.
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BACKGROUND: Childhood overweight and obesity levels are rising and becoming a concern globally. In Costa Rica, the prevalence of these conditions has reached alarming values. Spatial analyses can identify risk factors and geographical patterns to develop tailored and effective public health actions in this context. METHODS: A Bayesian spatial mixed model was built to understand the geographic patterns of childhood overweight and obesity prevalence in Costa Rica and their association with some socioeconomic factors. Data was obtained from the 2016 Weight and Size Census (6 - 12 years old children) and 2011 National Census. RESULTS: Average years of schooling increase the levels of overweight and obesity until reaching an approximate value of 8 years, then they start to decrease. Moreover, for every 10-point increment in the percentage of homes with difficulties to cover their basic needs and in the percentage of population under 14 years old, there is a decrease of 7.7 and 14.0 points, respectively, in the odds of obesity. Spatial patterns show higher values of prevalence in the center area of the country, touristic destinations, head of province districts and in the borders with Panama. CONCLUSIONS: Especially for childhood obesity, the average years of schooling is a non-linear factor, describing a U-inverted curve. Lower percentages of households in poverty and population under 14 years old are slightly associated with higher levels of obesity. Districts with high commercial and touristic activity present higher prevalence risk.
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Obesidade Infantil , Criança , Humanos , Adolescente , Obesidade Infantil/epidemiologia , Costa Rica/epidemiologia , Prevalência , Teorema de Bayes , Sobrepeso/epidemiologiaRESUMO
OBJECTIVES: We aimed to describe hemodynamic performance and clinical outcomes at 30-day follow-up of the balloon-expandable (BE) Myval transcatheter heart valve (THV) in low-risk patients. BACKGROUND: The results of the next-generation BE Myval THV in low-risk aortic stenosis (AS) patients are still unknown. METHODS: Retrospective registry performed in nine European centers including patients with low predicted operative mortality risk according to Society of thoracic surgeons (STS) and European system for cardiac operative risk evaluation (EuroSCORE-II) scores. RESULTS: Between September 2019 and February 2021, a total of 100 patients (51% males, mean age 80 ± 6.5 years) were included. Mean STS score and EuroSCORE-II were 2.4 ± 0.8% and 2.2 ± 0.7%, respectively. Intermediate sizes were used in 39% (21.5 mm: 8%, 24.5 mm: 15%, 27.5 mm: 15%). There were no cases of valve embolization, coronary artery occlusion, annulus rupture, or procedural death. A definitive pacemaker implantation was needed in eight patients (8%). At 30-day follow-up aortic valve area (0.7 ± 0.2 vs. 2.1 ± 0.6 cm2 ) and mean aortic valve gradient (43.4 ± 11.1 vs. 9.0 ± 3.7 mmHg) improved significantly (p < 0.001). Moderate aortic regurgitation occurred in 4%. Endpoints of early safety and clinical efficacy were 3 and 1%, respectively. CONCLUSIONS: Hemodynamic performance and 30-day clinical outcomes of the BE Myval THV in low-risk AS patients were favorable. Longer-term follow-up is warranted.
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Estenose da Valva Aórtica , Próteses Valvulares Cardíacas , Substituição da Valva Aórtica Transcateter , Idoso , Idoso de 80 Anos ou mais , Valva Aórtica/diagnóstico por imagem , Valva Aórtica/cirurgia , Estenose da Valva Aórtica/diagnóstico por imagem , Estenose da Valva Aórtica/etiologia , Estenose da Valva Aórtica/cirurgia , Feminino , Humanos , Masculino , Desenho de Prótese , Estudos Retrospectivos , Substituição da Valva Aórtica Transcateter/efeitos adversos , Substituição da Valva Aórtica Transcateter/métodos , Resultado do TratamentoRESUMO
The coronavirus SARS-CoV-2 has caused a pandemic with > 550 millions of cases and > 6 millions of deaths worldwide. Medical management of COVID-19 relies on supportive care as no specific targeted therapies are available yet. Given its devastating effects on the economy and mental health, it is imperative to develop novel antivirals. An ideal candidate will be an agent that blocks the early events of viral attachment and cell entry, thereby preventing viral infection and spread. This work reports functionalized titanium dioxide (TiO2)-based nanoparticles adsorbed with flavonoids that block SARS-CoV-2 entry and fusion. Using molecular docking analysis, two flavonoids were chosen for their specific binding to critical regions of the SARS-CoV-2 spike glycoprotein that interacts with the host cell angiotensin-converting enzyme-2 (ACE-2) receptor. These flavonoids were adsorbed onto TiO2 functionalized nanoparticles (FTNP). This new nanoparticulate compound was assayed in vitro against two different coronaviruses; HCoV 229E and SARS-CoV-2, in both cases a clear antiviral effect was observed. Furthermore, using a reporter-based cell culture model, a potent antiviral activity is demonstrated. The adsorption of flavonoids to functionalized TiO2 nanoparticles induces a ~ threefold increase of that activity. These studies also indicate that FTNP interferes with the SARS-CoV-2 spike, impairing the cell fusion mechanism. KEY POINTS/HIGHLIGHTS: ⢠Unique TiO2 nanoparticles displaying flavonoid showed potent anti-SARS-CoV-2 activity. ⢠The nanoparticles precisely targeting SARS-CoV-2 were quantitatively verified by cell infectivity in vitro. ⢠Flavonoids on nanoparticles impair the interactions between the spike glycoprotein and ACE-2 receptor.
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Tratamento Farmacológico da COVID-19 , Nanopartículas , Antivirais/química , Antivirais/farmacologia , Flavonoides/farmacologia , Humanos , Simulação de Acoplamento Molecular , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , TitânioRESUMO
Long-term combustion of low-quality coal may release hazardous elements into the environment causing serious environmental problems. This phenomenon is particularly prevalent in the Three Gorges Region of Southwest (SW), China. Cadmium (Cd), as well as other harmful elements are found to be highly enriched in coals and supergene environments in this area. In the existing literature, the behavioral issue of emission and transformation of the elevated trace elements during simulated household stove combustion from Cd-rich inferior coal remains unknown. This study investigated the emission of toxic elements, mineral assemblages, and provided technical guidance for reducing pollution by means of optimization combustion tests on inferior coals. The research may improve the understanding of geochemical characteristics from toxic elements emission in coal combustion endemic diseased areas. For this purpose, a series of simulated coal combustion experiments were conducted to reveal the release, mobility, and distribution of elevated elements in Cd-rich coal combustion products. The results showed that Cd, Mo, Cr, Cu, Zn, As, and Sb were significantly enriched in the inferior coals of the study area. Furthermore, large amounts of toxic elements were released as fly ash into the environment during the combustion process. In particular, combustion conditions played an important role in the emission and transformation of elevated elements. For example, higher temperatures promoted the release of Cd, Sb, Zn, and Tl into the environment. Oxygen-deficient combustion was found to liberate more Cd, Sb, and Tl to the atmosphere and generated complex mineral assemblages of lizardite, calcite, dolomite, forsterite, and enstatite. Moreover, toxic elements were found to be absorbed in the fine particle matter of fly ash from the endemic fluorosis area of SW, China. The findings of this work may aid to control the emission of toxic elements from inferior coals and mitigate the effect of toxic elements in the environment to protect human health.
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Carvão Mineral , Oligoelementos , Humanos , Carvão Mineral/análise , Cádmio , Cinza de Carvão/análise , Minerais , ChinaRESUMO
ABSTRACT: Martínez-Gómez, MG and Roberts, BM. Metabolic adaptations to weight loss: A brief review. J Strength Cond Res 36(10): 2970-2981, 2022-As the scientific literature has continuously shown, body mass loss attempts do not always follow a linear fashion nor always go as expected even when the intervention is calculated with precise tools. One of the main reasons why this tends to happen relies on our body's biological drive to regain the body mass we lose to survive. This phenomenon has been referred to as "metabolic adaptation" many times in the literature and plays a very relevant role in the management of obesity and human weight loss. This review will provide insights into some of the theoretical models for the etiology of metabolic adaptation as well as a quick look into the physiological and endocrine mechanisms that underlie it. Nutritional strategies and dietetic tools are thus necessary to confront these so-called adaptations to body mass loss. Among some of these strategies, we can highlight increasing protein needs, opting for high-fiber foods or programming-controlled diet refeeds, and diet breaks over a large body mass loss phase. Outside the nutritional aspects, it might be wise to increase the physical activity and thus the energy flux of an individual when possible to maintain diet-induced body mass loss in the long term. This review will examine these protocols and their viability in the context of adherence and sustainability for the individual toward successful body mass loss.
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Dieta Redutora , Redução de Peso , Adaptação Fisiológica , Dieta Redutora/métodos , Metabolismo Energético/fisiologia , Exercício Físico/fisiologia , Humanos , Obesidade , Redução de Peso/fisiologiaRESUMO
BACKGROUND AND AIMS: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the sole causative agent of coronavirus infectious disease-19 (COVID-19). METHODS AND RESULTS: We performed a retrospective single-center study of consecutively admitted patients between March 1st and May 15th, 2020, with a definitive diagnosis of SARS-CoV-2 infection. The primary end-point was to evaluate the association of lipid markers with 30-days all-cause mortality in COVID-19. A total of 654 patients were enrolled, with an estimated 30-day mortality of 22.8% (149 patients). Non-survivors had lower total cholesterol (TC) and low-density lipoprotein cholesterol (LDL-c) levels during the entire course of the disease. Both showed a significant inverse correlation with inflammatory markers and a positive correlation with lymphocyte count. In a multivariate analysis, LDL-c ≤ 69 mg/dl (hazard ratio [HR] 1.94; 95% confidence interval [CI] 1.14-3.31), C-reactive protein >88 mg/dl (HR 2.44; 95% CI, 1.41-4.23) and lymphopenia <1000 (HR 2.68; 95% CI, 1.91-3.78) at admission were independently associated with 30-day mortality. This association was maintained 7 days after admission. Survivors presented with complete normalization of their lipid profiles on short-term follow-up. CONCLUSION: Hypolipidemia in SARS-CoV-2 infection may be secondary to an immune-inflammatory response, with complete recovery in survivors. Low LDL-c serum levels are independently associated with higher 30-day mortality in COVID-19 patients.
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COVID-19/sangue , LDL-Colesterol/sangue , Dislipidemias/sangue , Idoso , Idoso de 80 Anos ou mais , Biomarcadores/sangue , COVID-19/diagnóstico , COVID-19/mortalidade , COVID-19/terapia , Regulação para Baixo , Dislipidemias/diagnóstico , Dislipidemias/mortalidade , Dislipidemias/terapia , Feminino , Humanos , Mediadores da Inflamação/sangue , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Medição de Risco , Fatores de Risco , Espanha , Fatores de TempoRESUMO
Natural organic matter (NOM) has been considered a critical substance in the transport and transformation of arsenic. NOM is a complex mixture of multifunctional organic components with a wide molecular weight (MW) distribution, and it is necessary to understand the complexation of arsenic with MW-dependent NOM fractions. In this study, humic acid (HA) was chosen as the representative fraction of NOM to investigate the complexation mechanism with arsenic. The bulk HA sample was fractionated to five fractions by ultrafiltration technology, and the complexing property of HA fractions with arsenic was analyzed by the dialysis method. We observed that the acidic and neutral conditions favor the complexation of HA fractions with arsenate (As(V)). The HA fractions with molecular weight > 100 kDa, 1-10 kDa, and <1 kDa have the stronger complexing capacity of As(V) than the other HA fractions. The bound As(V) percentage was positively associated with carboxyl content, phenolic content, and especially total acidity. A two-site ligand-binding model can describe the complexing capacity of arsenic onto HA fractions. The results can provide some fundamental information about the complexation of arsenic with MW-dependent HA fractions quantitatively.
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Arsênio , Substâncias Húmicas , Arseniatos , Arsênio/química , Substâncias Húmicas/análise , Peso Molecular , ÁguaRESUMO
The original version of this article unfortunately contained mistakes.
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PURPOSE: To determine whether changing from a tenofovir disoproxil fumarate (TDF)- to a tenofovir alafenamide fumarate (TAF)-containing regimen is correlated with weight changes in a human immunodeficiency virus (HIV)-positive adult cohort. METHODS: Retrospective analysis was conducted of data gathered from routine care in a university hospital in Munich, Germany, between July 2015 and June 2017. Data from patients' charts were extracted and a two-step approach was applied. First, weight/BMI progression within 1 year after initiation of either TDF or TAF was compared. Subsequently, weight measurements within subjects changing from a TDF- to a TAF-containing antiretroviral regimen were analyzed by means of a repeated measurements general linear model. RESULTS: After 360 days of initiating TAF, patients showed a mean (± standard deviation) percentual weight increase of 3.17 ± 0.21, whereas after 360 days of initiating TDF, patients only showed a mean (± standard deviation) percentual weight increase of 0.55 ± 0.17. The repeated measurements general linear model for within-subjects design showed a statistically significant correlation in weight after changing from a TDF to a TAF containing antiretroviral regimen. The weight difference between the two measurements while on TDF was not statistically significant, but every measure after switching to TAF was significantly higher than the previous. CONCLUSION: Changing from a TDF- to a TAF-containing regimen is correlated with weight gain in this retrospectively analyzed real-world cohort in Munich, Germany.
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Adenina/análogos & derivados , Fármacos Anti-HIV/uso terapêutico , Soropositividade para HIV/tratamento farmacológico , Tenofovir/uso terapêutico , Aumento de Peso/efeitos dos fármacos , Redução de Peso/efeitos dos fármacos , Adenina/administração & dosagem , Adenina/uso terapêutico , Adulto , Alanina , Fármacos Anti-HIV/administração & dosagem , Estudos de Coortes , Feminino , Fumaratos/administração & dosagem , Fumaratos/uso terapêutico , Alemanha , Hospitais Universitários , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Tenofovir/administração & dosagemRESUMO
Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO2 by NO2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH3 neutralization or under cloud conditions. Under polluted environments, this SO2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH3 and NO2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.
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Poluentes Atmosféricos/análise , Material Particulado/análise , Sulfatos/efeitos adversos , Aerossóis/análise , Poluição do Ar/análise , China , Clima , Monitoramento Ambiental/métodos , Humanos , Londres , Nitratos , Dióxido de Nitrogênio/efeitos adversos , Dióxido de Nitrogênio/química , Óxidos de Nitrogênio/análise , Tamanho da Partícula , Material Particulado/efeitos adversos , Sulfatos/análise , Óxidos de Enxofre/análise , Tempo (Meteorologia)RESUMO
A novel zerovalen-iron-biochar composite (nZVI/SBC) was synthesized by using FeCl3-laden sorghum straw biomass as the raw material via a facile one-step pyrolysis method without additional chemical reactions (e.g., by NaBH4 reduction or thermochemical reduction). The nZVI/SBC was successfully employed as an activator in phenol degradation by activated persulfate. XRD, SEM, N2 adsorption-desorption and atomic absorption spectrophotometry analysis showed that the nanosized Fe0 was the main component of the 4ZVI/SBC activator, which was a mesopore material with an optimal FeCl3·6H2O/biomass impregnation mass ratio of 2.7 g/g. The 4ZVI/SBC activator showed an efficient degradation of phenol (95.65% for 30 min at 25 °C) with a large specific surface area of 78.669 m2·g-1. The recovery of 4ZVI/SBC activator after the degradation reaction of phenol can be realized with the small amount of dissolved iron in the water. The 4ZVI/SBC activator facilitated the activation of persulfate to degrade phenol into non-toxic CO2 and H2O. The trend of Cl-, SO4 2- and NO3 - affected the removal efficiency of phenol by using the 4ZVI/SBC activator in the following order: NO3 - > SO4 2- > Cl-. The one-step synthesis of the nanosized zerovalent-iron-biochar composite was feasible and may be applied as an effective strategy for controlling organic waste (e.g. phenol) by waste biomass.
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Ferro , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , FenóisRESUMO
In the original paper, there was an error in the communication unit 1. The communication unit was "Liaoning Engineering Research Center for Treatment and Recycling of Industrially Discharged Heavy Metals, Shenyang University of Chemical Technology, Shenyang 110142, People's Republic of China".
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In order to acquire the spatial distribution, speciation, and risk assessment of arsenic (As), 18 sediment samples were collected in the middle and upper reaches (Nanpan River, Beipan River, Hongshui River, Diaojiang River, and Duliu River) of the Xijiang River basin, China. The chemical fractions of As in the collected sediments were mainly dominated by the residual fraction and the Fe (Mn, Al) oxide/oxyhydroxides fractions. The correlation analysis results showed that the chemical fraction of As in sediments had close correlations with Mn, good correlations with Fe and organic matter (OM), while weak correlations with Al and carbonate. In addition, it also showed that Diaojiang River basin was found to have an extremely high As pollution status and suffered from high ecological risk. Duliu River and Nanpan River had moderately polluted levels of As and showed a low ecological risk. The other sample sites of Xijiang River basin were uncontaminated of As. The assessment results from this study indicated that the different types of species present based on the chemical fractionation of As from the Xijiang River basin showed different risks. Graphical abstract.
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Arsênio/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Poluentes Químicos da Água/análise , Poluição Química da Água/análise , Carbonatos/análise , China , Ecologia , Metais Pesados/análise , Medição de Risco , Rios/químicaRESUMO
It is well known that calcium arsenates may not be a good choice for arsenic removal and immobilization in hydrometallurgical practices. However, they are still produced at some plants in the world due to various reasons. Furthermore, calcium arsenates can also naturally precipitate under some specific environments. However, the transformation process of poorly crystalline calcium arsenates (PCCA) and the stability of these samples under atmospheric CO2 are not yet well understood. This work investigated the transformation process of PCCA produced by using different neutralization reagents (CaO vs. NaOH) with various Ca/As molar ratios at pHâ¯7-12 in the presence of atmospheric CO2. After aging at room temperature for a period of time, for samples neutralized with NaOH and precipitated at pHâ¯10 and 12, release of arsenic back into the liquid phase occurred. In contrast, for the samples precipitated at pHâ¯8, the aqueous concentration of arsenic was observed to decrease. XRD, Raman, and SEM results suggested that the formation of various types of crystalline calcium carbonates and/or calcium arsenates controls the arsenic behavior. Moreover, the application of lime may enhance the stability of the generated PCCA. However, no matter what neutralization reagent is used, the stability of the generated PCCA is still of concern.
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Arseniatos/química , Arsênio/análise , Compostos de Cálcio/química , Precipitação QuímicaRESUMO
We sought to determine patterns of injury in our Latino trauma community targeting alcohol (EtOH) intoxication as an influential variable. With the information gained in our culturally specific and culturally sensitive trauma community, we can use the information to fine-tune our trauma preventive medicine programs. Trauma injuries are the third largest contributor to racial disparities in the United States. Alcohol is involved in approximately half of all trauma admissions to trauma centers around the country. Some investigators have shown that Latinos have higher rates of high-risk drinking, and this factor is independently associated with mortality after trauma. This study is a retrospective review of 524 Latino blunt and penetrating trauma admissions for years (2012-2014). Electronic medical records with the hospital trauma registry charts were evaluated. The trauma registry database included age, gender, EtOH, mechanism of injury, location, insurance, and disposition. Statistical significance was used with chi-square test. Our results show a predominantly male population with falls being the primary mechanism of injury. Intoxicated injuries occurred mostly at bars/clubs, but a substantial amount occurred at the workplace. Despite having a majority of the injuries occurring with patients that have Medicaid or Charity Care insurance, a certain amount of the alcohol-related injuries had private insurance. Many of our Latino trauma patients are still suffering from trauma-related EtOH intoxication. With the information obtained from our project, we will be able to fine-tune and target our trauma preventive medicine program to provide education for our inner-city Latino community of EtOH intoxication-related trauma injuries.
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Intoxicação Alcoólica/etnologia , Intoxicação Alcoólica/prevenção & controle , Prevenção Primária/organização & administração , Ferimentos e Lesões/diagnóstico , Ferimentos e Lesões/etnologia , Adolescente , Adulto , Distribuição por Idade , Estudos de Coortes , Feminino , Hispânico ou Latino/estatística & dados numéricos , Humanos , Incidência , Escala de Gravidade do Ferimento , Masculino , Desenvolvimento de Programas , Avaliação de Programas e Projetos de Saúde , Sistema de Registros , Estudos Retrospectivos , Distribuição por Sexo , Centros de Traumatologia , Estados Unidos , Ferimentos e Lesões/terapia , Adulto JovemRESUMO
The heterogeneous chemistry of glyoxal on sulfuric acid surfaces has been investigated at various acid concentrations and temperatures, utilizing a low-pressure fast flow laminar reactor coupled to an ion drift-chemical ionization mass spectrometer (ID-CIMS). The uptake coefficient (γ) of glyoxal ranges from (1.2 ± 0.06) × 10(-2) to (2.5 ± 0.01) × 10(-3) for 60-93 wt % H2SO4 at 253-273 K. The effective Henry's Law constant (H*) ranges from (98.9 ± 4.9) × 10(5) to (1.6 ± 0.1) × 10(5) M atm(-1) for 60-93 wt % at 263-273 K. Both the uptake coefficient and Henry's Law constant increase with decreasing acid concentration and temperature. Our results reveal a reaction mechanism of hydration followed by oligomerization for glyoxal on acidic media, indicating an efficient aqueous reaction of glyoxal on hygroscopic particles leading to secondary organic aerosol formation.
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Aerossóis/química , Glioxal/química , Ácidos Sulfúricos/química , Espectrometria de Massas , Pressão , Soluções , Temperatura , Fatores de Tempo , Água/química , MolhabilidadeRESUMO
Liquid digestate of food waste is an ammonium-, ferric- and sulfate-laden leachate produced during digestate dewatering, where the carbon source is insufficient for nitrogen removal. A two-stage partial nitrification-anammox/denitrification process was established for nitrogen removal of liquid digestate without pre-treatment (>300 d), through which nitrogen (95 %), biodegradable organics (100 %), sulfate (78 %) and iron (100 %) were efficiently removed. Additional ammonium conversion (20 %N) might be coupled with ferric and sulfate reduction, while produced nitrite could be further converted to di-nitrogen gas through anammox (75 %) and denitrification (25 %). Notably, since increasingly contribution of hydroxylamine producing nitrous oxide, and up-regulated expression of electron transfer and cytochrome c protein, the enhanced ammonium oxidation was probably conducted through extracellular polymeric substances-mediated electron transfer between sulfate/ferric-reducers and aerobic ammonium oxidizers. Thus, the established partial nitrification-anammox/denitrification process might be a cost-efficient nitrogen removal technology for liquid digestate, benefitting to domestic waste recycling and carbon neutralization.
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Compostos de Amônio , Eliminação de Resíduos , Nitrificação , Desnitrificação , Perda e Desperdício de Alimentos , Nitrogênio , Sulfatos , Alimentos , Oxidação Anaeróbia da Amônia , Oxirredução , Ferro , Carbono , Reatores Biológicos , EsgotosRESUMO
The extraction and utilization of uranium (U) ores have led to the release of significant amounts of potentially toxic metal(loid)s (PTMs) into the environment, constituting a grave threat to the ecosystem. However, research on the distribution and migration mechanism of U, chromium (Cr), and their accompanying PTMs in soil-plant system around U hydrometallurgical area remains insufficient and poorly understood. Herein, the distribution, migration, and risk level of PTMs were evaluated in soil and plant samples around U hydrometallurgical area, Northern Guangdong, China. The results demonstrated that the maximum content of U and Cr found in the analyzed soils were up to 84.2 and 238.9 mg/kg, respectively. These values far exceed the soil background values in China and other countries. The highest content of U (53.6 mg/kg) was detected in Colocasia antiquorum Schott, and the highest content of Cr (349.5 mg/kg) was observed in Pteridium aquilinum, both of which were enriched in their roots. The risk assessment of PTMs demonstrated that the study area suffered from severe pollution (PN > 3), especially from U, Cr, Th, and As, suggesting the non-negligible anthropogenic impacts. Hence, in light of the significant ecological hazard posed by the U hydrometallurgical area, it is imperative to implement appropriate restoration measures to ensure the human health and maintain the stability of the ecosystem.