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1.
Sichuan Da Xue Xue Bao Yi Xue Ban ; 50(4): 494-499, 2019 Jul.
Artigo em Chinês | MEDLINE | ID: mdl-31642225

RESUMO

OBJECTIVE: To determine the myocardial texture features of cardiac magnetic resonance (CMR) in healthy adult Han populations. METHODS: 59 healthy Han volunteers were recruited for this study from May 2016 to November 2017. CMR examinations were performed on the participants with a 3.0T scanner (Tim Trio, Siemens Medical Solution) to estimate the functional parameters, Native T1 value and ECV. Texture analysis (TA) was performed on the region of interest (ROI) in the left ventricle myocardium on T1 mapping images, with 40 myocardial texture features being extracted. Differences in the myocardial texture features across gender and age groups were analyzed through Student's t-tests or Wilcoxon signed-rank tests. Spearman correlations were analyzed between the myocardial texture features and age, native T1 value and extracellular volume (ECV). RESULTS: Of the 59 participants, 28 were women and 29 were in the younger age group (< 45 years old). The male participants had higher left ventricular mass index (Lvmassi) and lower native T1 than their female counterparts (P < 0.01). No gender differences in blood pressure, heart rate, left ventricular ejection fraction (LVEF) and ECV values were found. Ten of the forty myocardial texture features showed gender differences, including two first order features and eight Grey-level co-occurrence matrix (GLCM) features. Gender differences appeared in five first order features and eight GLCM features in the younger group (< 45 years old), but not in the older group (≥45 years old). Eight myocardial texture features were correlated with age, including five first order features and three GLCM features (all P < 0.01). Six first-order texture features were correlated with Native T1 values of the left ventricle middle myocardium. Three first-order texture features were correlated with ECV. CONCLUSION: Myocardial texture features in T1 mapping images vary by gender and age in healthy Han populations.


Assuntos
Coração/diagnóstico por imagem , Miocárdio , Função Ventricular Esquerda , Adulto , Fatores Etários , Meios de Contraste , Feminino , Voluntários Saudáveis , Humanos , Espectroscopia de Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Fatores Sexuais
2.
IUBMB Life ; 71(12): 2048-2054, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31381266

RESUMO

Malignant hyperthermia is a pharmacogenetic disorder, which is an uncommon but frequently fatal intricacy of inhalation anesthesia in man. It causes a quick rise in body temperature to highly irreversible levels, which causes death in around three of four cases. The trigger anesthetics cause an anomalous, continued ascent in myoplasmic calcium levels. Possible mechanisms by which continuous release of sodium, calcium from skeletal muscle plasma membrane and sarcoplasmic reticulum stores respectively can produce the profound hyperthermia are discussed.

3.
Phys Chem Chem Phys ; 14(37): 12919-29, 2012 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-22899166

RESUMO

We propose that aromatic nitro and amine compounds undergo photochemical reductive and oxidative coupling, respectively, to specifically produce azobenzene derivatives which exhibit characteristic Raman signals related to the azo group. A photoinduced charge transfer model is presented to explain the transformations observed in para-substituted ArNO(2) and ArNH(2) on nanostructured silver due to the surface plasmon resonance effect. Theoretical calculations show that the initial reaction takes place through excitation of an electron from the filled level of silver to the lowest unoccupied molecular orbital (LUMO) of an adsorbed ArNO(2) molecule, and from the highest occupied molecular orbital (HOMO) of an adsorbed ArNH(2) molecule to the unoccupied level of silver, during irradiation with visible light. The para-substituted ArNO(2)(-)˙ and ArNH(2)(+)˙ surface species react further to produce the azobenzene derivatives. Our results may provide a new strategy for the syntheses of aromatic azo dyes from aromatic nitro and amine compounds based on the use of nanostructured silver as a catalyst.

4.
Chem Commun (Camb) ; 47(9): 2520-2, 2011 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-21267488

RESUMO

When p-aminothiophenol (PATP) is used as a probe molecule and adsorbs on silver and gold nanogaps, a significant change of relative SERS intensities can be observed. Our DFT calculations show that surface photocatalytic coupling reactions yield a new surface species of p,p'-dimercaptoazobenzene (DMAB) causing the significant change in the SERS spectra.


Assuntos
Nanopartículas Metálicas/química , Fótons , Adsorção , Compostos Azo/química , Catálise , Ouro/química , Nanotecnologia , Prata/química , Análise Espectral Raman , Propriedades de Superfície
5.
J Phys Chem A ; 112(6): 1313-21, 2008 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-18215023

RESUMO

Binding interactions and Raman spectra of water in hydrogen-bonded anionic complexes have been studied by using the hybrid density functional theory method (B3LYP) and ab initio (MP2) method. In order to explore the influence of hydrogen bond interactions and the anionic effect on the Raman intensities of water, model complexes, such as the negatively charged water clusters ((H2O)n-, n = 2 and 3), the water...halide anions (H2O...X-, X = F, Cl, Br, and I), and the water-metal atom anionic complexes (H2O...M-, M = Cu, Ag, and Au), have been employed in the present calculations. These model complexes contained different types of hydrogen bonds, such as O-H...X-, O-H...M-, O-H...O, and O-H...e-. In particular, the last one is a dipole-bound electron involved in the anionic water clusters. Our results showed that there exists a large enhancement in the off-resonance Raman intensities of both the H-O-H bending mode and the hydrogen-bonded O-H stretching mode, and the enhancement factor is more significant for the former than for the latter. The reasons for these spectral properties can be attributed to the strong polarization effect of the proton acceptors (X-, M-, O, and e-) in these hydrogen-bonded complexes. We proposed that the strong Raman signal of the H-O-H bending mode may be used as a fingerprint to address the local microstructures of water molecules in the chemical and biological systems.


Assuntos
Cobre/química , Ouro/química , Halogênios/química , Modelos Teóricos , Prata/química , Água/química , Algoritmos , Ânions/química , Elétrons , Ligações de Hidrogênio , Modelos Moleculares , Prótons , Análise Espectral Raman/métodos
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