Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Filtrar
Mais filtros

Bases de dados
País/Região como assunto
Tipo de documento
Intervalo de ano de publicação
1.
PLoS One ; 17(7): e0271132, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35802669

RESUMO

BACKGROUND: Hypokalemia is a frequent electrolyte imbalance in patients with COVID-19. The aim of this study was to estimate the association between hypokalemia and clinical prognosis in patients with moderate COVID-19. METHODS: A single-center, retrospective, observational study was conducted on 81 non-ICU admitted patients with moderate COVID-19 according to the criteria issued by the Chinese Health Bureau in the Third People's Hospital of Yangzhou (Northern Jiangsu People's Hospital New District Branch) from 4th to 25th August 2021. The demographic, clinical, and laboratory data were reviewed and collected, then the correlation between hypokalemia and prognosis was determined. RESULTS: The level of serum potassium of patients ranged from 2.80 mmol/L to 4.70 mmol/L. Hypokalemia was detected in 39 out of the 81 included patients (48.15%) during hospitalization. Patients with hypokalemia had prolonged days of negative nucleic acid conversion and hospital stay. Correlation analysis showed that the level of serum potassium was negatively correlated with days of negative nucleic acid conversion and length of hospital stay. Bivariate logistic regression analysis proved that hypokalemia was a risk factor for prolonged hospital stay in patients with moderate COVID-19. CONCLUSION: Hypokalemia was prevalent in patients with moderate COVID-19 in Yangzhou, China. Hypokalemia was associated with the prolonged hospital stay in patients with moderate COVID-19.


Assuntos
COVID-19 , Hipopotassemia , Ácidos Nucleicos , COVID-19/complicações , COVID-19/epidemiologia , China/epidemiologia , Humanos , Hipopotassemia/complicações , Hipopotassemia/epidemiologia , Potássio , Prognóstico , Estudos Retrospectivos
2.
J Hazard Mater ; 416: 126250, 2021 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-34492993

RESUMO

The research on the mechanisms and kinetics of radical oxidation in peracetic acid-based advanced oxidation processes was relatively limited. In this work, HO• and organic radicals mediated reactions of acetaminophen (ACT) were investigated, and the reactivities of important organic radicals (CH3COO• and CH3COOO•) were calculated. The results showed that initiated reaction rate constants of ACT are in the order: CH3COO• (5.44 × 1010 M-1 s-1) > HO• (7.07 × 109 M-1 s-1) > CH3O• (1.57 × 107 M-1 s-1) > CH3COOO• (3.65 × 105 M-1 s-1) >> •CH3 (5.17 × 102 M-1 s-1) > CH3C•O (1.17 × 102 M-1 s-1) > CH3OO• (11.80 M-1 s-1). HO•, CH3COO• and CH3COOO• play important roles in ACT degradation. CH3COO• is another important radical in the hydroxylation of aromatic compounds in addition to HO•. Reaction rate constants of CH3COO• and aromatic compounds are 1.40 × 106 - 6.25 × 1010 M-1 s-1 with addition as the dominant pathway. CH3COOO• has high reactivity to phenolate and aniline only among the studied aromatic compounds, and it was more selective than CH3COO•. CH3COO•-mediated hydroxylation of aromatic compounds could produce their hydroxylated products with higher toxicity.


Assuntos
Ácido Peracético , Poluentes Químicos da Água , Acetaminofen/toxicidade , Radical Hidroxila , Cinética , Oxirredução , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
3.
Environ Res ; 188: 109713, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32535355

RESUMO

The pharmaceutical and personal care products (PPCPs) in aquatic environment have aroused more interest recently. Many of them are hard to degrade by the typical biological treatments. Diclofenac (DCF), as a significant anti-inflammatory drug, is a typical PPCP and widely existed in water environment. It is reported that DCF has adverse effects on aquatic organisms. This work aims to investigate the mechanism, kinetics and ecotoxicity assessment of DCF transformation initiated by O3 in aqueous solution, and provide a solution to the degradation of DCF. The O3-initiated oxidative degradations of DCF were performed by quantum chemical calculations, including thirteen primary reaction pathways and subsequent reactions of the Criegee intermediates with H2O, NO and O3. Based on the thermodynamic data, the kinetic parameters were calculated by the transition state theory (TST). The total reaction rate constant of DCF initiated by O3 is 2.57 × 103 M-1 s-1 at 298 K and 1 atm. The results show that the reaction rate constants have a good correlation with temperature. The acute and chronic toxicities of DCF and its degradation products were evaluated at three different trophic levels by the ECOSAR program. Most products are converted into less toxic or harmless products. Oxalaldehyde (P3) and N-(2,6-dichlorophenyl)-2-oxoacetamide (P6) are still harmful to the three aquatic organisms, which should be paid more attention in the future.


Assuntos
Ozônio , Poluentes Químicos da Água , Diclofenaco/toxicidade , Cinética , Oxirredução , Ozônio/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
4.
Sci Total Environ ; 685: 729-740, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31234135

RESUMO

The OH-initiated transformation mechanisms, kinetics and ecotoxicity assessment of guaiacol (2-methoxyphenol) in the presence of O2/NOx were investigated both in atmosphere and wastewater. The solvent effect lowers the energy barriers of initial OH-addition reactions more than H-abstraction reactions, leading to much higher addition branching ratio (Γadd) of 0.92 in aqueous solution than that of 0.42 in gas-phase. At 298 K, the overall rate constants of the title reactions in atmosphere and wastewater are 5.56 × 10-12 and 1.41 × 10-11 cm3 molecule-1 s-1 with corresponding half-lives of 34.6 h and 0.82 s, respectively. In atmosphere, all the proposed favorable products including nitroguaiacols, methoxybenzoquinone, 2-hydroxyphenyl formate, 2-methoxybenzene-1, 3-diol and dialdehyde could contribute to secondary organic aerosols (SOAs). In wastewater, NO2 addition reactions lead to higher toxicity of products (nitroguaiacols and 2-methoxybenzene-1, 4-diol) than that of parental guaiacol. However, O2/NO addition pathways may generate less harmful products except for methoxybenzoquinone (P3) which is with higher toxicity than guaiacol. Therefore, more attention should be focused on the products formed from OH-initiated reactions of guaiacol both in atmosphere and wastewater.

5.
Environ Pollut ; 243(Pt B): 1772-1780, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30408864

RESUMO

Creosol and 4-ethylguaiacol are two important methoxyphenols, lignin pyrolysis products, which are discharge into the atmosphere in large quantities. In this work, theoretical calculations of the reaction mechanism towards the two compounds with NO3 radicals was performed using DFT method. The rate constants and toxicity assessment were also investigated. The atmospheric lifetime for creosol and 4-ethylguaiacol were 0.82 and 0.19 h, respectively. A new reaction pathway was proposed for the transformation of methoxyl into hydroxyl, which has not yet been clarified in previous studies. The toxicity of methoxyphenols and their degradation products is closely related to their hydrophobicity. Although most degradation products are less toxic, they also should be pay more attention, especially for nitro-substituents. A new reaction pathway was proposed for the transformation of methoxyl into hydroxyl. The toxicity is closely related to their hydrophobicity.


Assuntos
Poluentes Atmosféricos/análise , Poluentes Atmosféricos/química , Cresóis/química , Guaiacol/análogos & derivados , Radical Hidroxila/química , Nitratos/química , Atmosfera , Guaiacol/química , Cinética , Modelos Teóricos , Óxidos de Nitrogênio/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA