Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 4 de 4
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Artigo em Inglês | MEDLINE | ID: mdl-38700537

RESUMO

BACKGROUND: Understanding the pathophysiology of sudden sensorineural hearing loss (SSNHL) and identifying its clinical symptoms and associated risk factors are crucial for doctors in order to create effective prevention and therapeutic methods for this prevalent otolaryngologic emergency. METHODS: This study focuses on investigating the correlation between the C-reactive protein/albumin ratio (CAR) and SSNHL complicated by hypertension. In this study, 120 patients diagnosed with SSNHL were divided into groups with and without hypertension, and propensity score matching was used to compare and analyze the severity, type, prognosis, and CAR levels in SSNHL. RESULTS: The results showed that the SSNHL group with hypertension had significantly higher CAR levels, age, hearing curve abnormalities, and more severe hearing loss compared to the control group with isolated SSNHL. These differences were statistically significant (p < 0.001). Among different subtypes of SSNHL, CAR levels increased progressively with the advancement of the condition, and these differences were also statistically significant (p < 0.001). CONCLUSION: In summary, in patients with SSNHL, those with hypertension had higher CAR levels than those without a history of hypertension, and they experienced more severe hearing loss. Moreover, there was a clear correlation between CAR levels and the extent of SSNHL, indicating that greater CAR levels in patients with SSNHL are connected to more severe hearing loss in various hearing patterns and perhaps indicative of a poorer prognosis.

2.
Se Pu ; 34(2): 152-7, 2016 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-27382719

RESUMO

Based on the unique molecular structure of ferrocene and its potential as a new liquid chromatography separation medium, a new silica-bonded (4-cyclopentadienyl benzoic acid-iron-toluene) hexafluorophosphoric acid stationary phase was prepared. The structure of this new material was characterized by infrared spectroscopy, elemental analysis, thermogravimetric analysis et al. The chromatographic performance and retention mechanism of this new stationary phase were evaluated using different solute probes, including polycyclic aromatic hydrocarbons (PAHs), positional isomers of naphthylamine, positional isomers of nitro-aniline, nitroimidazoles, organic phosphorus et al. It could provide various action sites for different solutes in normal-phase chromatography such as π electron transfer, π-π electron interactions, dipole-dipole interactions, and electrostatic interactions with the substrates. And the possible separation mechanisms are discussed.

3.
Talanta ; 144: 1044-51, 2015 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-26452925

RESUMO

A new stationary phase for high-performance liquid chromatography was prepared by covalently bonding N-ferrocenyl(benzoyl)amino-acid esters (L(1)) onto silica gel using 3-aminopropyltriethoxysilane as coupling reagent. The structure of new material was characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic behavior of the phase was illustrated in reversed-phase (RP) and normal-phase (NP) modes using polycyclic aromatic hydrocarbons (PAHs), aromatics positional isomers, amines, 5-nitroimidazoles, organophosphorus pesticides and phenols as probes. Multiple mechanisms including hydrophobic, hydrogen bonding, π-π, dipole-dipole, charge-transfer and acid-base equilibrium interactions are involved. Thus, multi-interaction mechanisms and mixed-mode separation of the new phase can very likely guarantee its excellent chromatographic performance for the analysis of complex samples. The L(1) AminoSil column was successfully employed for the analysis of organophosphorus pesticides in vegetable.


Assuntos
Aminoácidos/química , Cromatografia Líquida de Alta Pressão/métodos , Compostos Orgânicos/isolamento & purificação , Sítios de Ligação , Ésteres , Compostos Orgânicos/química , Propilaminas , Silanos/química , Dióxido de Silício/química
4.
J Chromatogr A ; 1283: 75-81, 2013 Mar 29.
Artigo em Inglês | MEDLINE | ID: mdl-23415442

RESUMO

A new 4-ferrocenylbenzoyl chloride-bonded stationary phase (Fc-SiO2) for high performance liquid chromatography (HPLC) was prepared using 3-aminopropyltriethoxysilane as coupling reagent. The structure of new material was characterized by infrared spectroscopy, elemental analysis and thermogravimetric analysis. The chromatographic performance and retention mechanism of the new stationary phase were evaluated in reversed-phase (RP) or normal-phase (NP) modes using different solute probes including polycyclic aromatic hydrocarbons (PAHs), mono-substituted benzenes, ferrocenyl derivatives, aromatic amines, pyrazine derivatives, drug intermediate pyrrole isomers and sulfonamides. The results showed that this Fc-SiO2 could provide various interactions for different solutes, such as hydrophobic, hydrogen bonding, π-π, dipole-dipole and charge-transfer interactions. The synergistic effects resulting from cyclopentadienyl (Cp) groups, aromatic ring and amido function in the new material improved the separation selectivity by multiple retention mechanisms. The retention behaviors of the analytes on Fc-SiO2 column were investigated with the assistance of quantum chemistry calculation results using DFT-B3LYP/STO-3G(*) base group.


Assuntos
Benzoatos/química , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Compostos Ferrosos/química , Cromatografia de Fase Reversa/instrumentação , Cromatografia de Fase Reversa/métodos , Metalocenos , Compostos Orgânicos/química , Compostos Orgânicos/isolamento & purificação , Dióxido de Silício/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...