RESUMEN El objetivo de esta investigación es analizar la dinámica de degeneración de suelos poco compactos y el método de evaluación de subsidencia del campo sísmico. En este estudio, suelos poco compactos tipo Q3 fueron objeto de investigación, y las propiedades dinámicas de estos suelos con 10, 20, 30 y 35 por ciento de contenido de húmedad fueron evaluadas en experimentos triaxiales. Además, se analizaron las características de subsidencia sísmica de los suelos poco compactos con densidades secas de 1.4g/cm3, 1.6g/cm3, y 1.8g/cm3 y un índice de consolidación de esfuerzo de 1.0, 1.2, 1.4 y 1.6. Luego, el método de estimación de la subsidencia sísmica simplificada se utilizó para calcular la relación entre los coeficientes de subsidencia sísmica en diferentes profundidades en un campo dimensional, los tiempos del ciclo y la profundidad de subsidencia. Los resultados muestran que entre más alto sea el contenido de agua en los suelos poco compactos es mayor el cambio de subsidencia sismica. Y que entre mayor sea la densidad seca de estos suelos, más pequeño es el grado de cambio de la subsidencia sísmica. Y, finalmente, cuando el índice de consolidación de esfuerzo es mayor también será mayor el cambio de subsidencia sísmica que ocurre en los suelos poco compactos. Cuando la profundidad del suelo alcanza los 9.5 metros, el coeficiente de subsidencia sísimica puede alcanzar el 0.8 por ciento. Cuando la profundidad de la capa del suelo es de 10 metros, el grado de subsidencia sísmica es mayor. Cuando la profundidad de la capa del suelo es entre 12 y 16 metros, el asentamiento causado por la subsidencia del movimiento de tierra es menor. Mientras la profundidad de la capa del suelo se encuentre entre 8 y 12 metros, el grado de asentamiento es mayor.

ABSTRACT The objective of this research is to analyze the dynamic degeneration of loess and the evaluation method of field seismic subsidence. In this study, Q3 loess is taken as the research object, and the dynamic properties of loess with 10%, 20%, 30% and 35% moisture content are tested by triaxial experiment. In addition, seismic subsidence characteristics of loess with dry densities of 1.4g/cm3, 1.6g/cm3, and 1.8g/cm3 and consolidation stress ratios of 1.0, 1.2, 1.4, and 1.6 are analyzed. Then the simplified seismic subsidence estimation method is used to calculate the relationship between seismic subsidence coefficients at different soil depth in one dimensional field, cycle times, and subsidence depth. The results show that the higher the water content of loess is, the greater the change of seismic subsidence appears. The larger the dry density of loess is, the smaller the change degree of seismic subsidence appears. The larger the consolidation stress ratio is, the greater the change of seismic subsidence occurs in loess. When the depth of soil reaches 9.5m, the maximum seismic subsidence coefficient can reach 0.8%. When the depth of soil layer is 10m, the degree of seismic subsidence is the largest. When the depth of soil layer is 12~16m, the settlement depth caused by earthquake subsidence is small. While the depth of soil layer is 8~12m, the settlement degree is large.

OBJECTIVES: This study investigated whether the serum matrix metalloproteinase-9 level is an independent predictor of recurrence after catheter ablation for persistent atrial fibrillation. METHODS: Fifty-eight consecutive patients with persistent atrial fibrillation were enrolled and underwent catheter ablation. The serum matrix metalloproteinase-9 level was detected before ablation and its relationship with recurrent arrhythmia was analyzed at the end of the follow-up. RESULTS: After a mean follow-up of 12.1±7.2 months, 21 (36.2%) patients had a recurrence of their arrhythmia after catheter ablation. At baseline, the matrix metalloproteinase-9 level was higher in the patients with recurrence than in the non-recurrent group (305.77±88.90 vs 234.41±93.36 ng/ml, respectively, p=0.006). A multivariate analysis showed that the matrix metalloproteinase-9 level was an independent predictor of arrhythmia recurrence, as was a history of atrial fibrillation and the diameter of the left atrium. CONCLUSION: The serum matrix metalloproteinase-9 level is an independent predictor of recurrent arrhythmia after catheter ablation in patients with persistent atrial fibrillation.

Neste artigo foi utilizada a tecnologia de interferometria SAR ground-based para monitoramento de estruturas. Esta tecnologia é reconhecida como uma ferramenta ponderosa para monitoramento do terreno e para detecção de alterações estruturais. O monitoramento de deformações em grandes projetos tem sido um tópico importante. De acordo com o princípio de interferometria GBSAR e das características do sistema IBIS os autores analisaram as fontes de erros no monitoramento de deformações, e extraíram experimentalmente a fase atmosférica baseado na análise de dispersão. A análise do efeito atmosférico é discutida neste artigo e propõe-se um método de correção atmosférica para remove-lo, de modo que o deslocamento efetivo possa ser obtido. Os resultados desta abordagem foram comparados com os métodos tradicionais nesta campanha e conclui-se que a tecnologia GBInSAR pode ser utilizada no monitoramento de grandes projetos com alta acurácia.

In this paper, a ground-based SAR interferometry technology was used to monitor major enginerring. This technology has been recognized as a powerful tool for terrain monitoring and structural change detecting. Deformation monitoring for large project has been a hot issue among them. According to GBSAR interferometry principle and characteristics of IBIS system, the authors analysis the error sources of deformation monitoring, and experimentally extract atmospheric phase which should removed based on permanent scatterer analysis. Atmospheric disturbance effect analysis is discussed in this paper, and an atmospheric correction method is proposed to remove atmospheric effect, then the effective displacement can be retrieved. Results from this approach have been compared with that from traditional method in this campaign, GBInSAR technology can be exploited successfully in deformation monitoring for major projects with high accuracy 1-3.

Chiral stationary phases (CSPs) and molecular structure of enantiomers are two independent but related aspects in enantioseparation, which are discussed on the basis of the experimental data from the previous study. Two enantioseparation experiments are performed to illustrate the relationship between enantiomer structures and chiral stationary phases, one is the resolution of mandelic acid derivatives and the other is about prasugrel. Thermodynamic mechanism and theoretical study with computational chemistry method is helpful to understand the interactions of enantiomer and CSPs.

Fases estacionarias quirales (CSP) y estructura molecular de enantiómeros son dos aspectos relacionados entre sí, pero independientes en la separación cromatográfica de estos compuestos; ambos aspectos se discuten en este trabajo con base en los datos experimentales de los estudios anteriores. Se llevaron a cabo dos experimentos para ilustrar la relación entre las estructuras de enantiómeros y fases estacionarias quirales; uno con los derivados del ácido mandélico y el otro con prasugrel. Son útiles los mecanismo termodinámico y el estudio teórico mediante herramientas de la química computacional para entender las interacciones de enantiómero con CCSps.

The development of a simple and efficient analytical method for determination of enantiomeric purity of 2-(aminomethyl)-1-ethylpyrrolidine was presented. The method was based on pre-column derivatization of 2-(aminomethyl)-1-ethylpyrrolidine with 4-nitrobenzoic acid completing separation of the enantiomers on high performance liquid chromatographic (HPLC) chiral stationary phase (CSP). After optimizing all the effective parameters, the best performances were achieved on a Chiralcel OD-H analytical column (250 × 4.6 mm) using n-hexane: ethanol (98:2, v/v) containing 0.2% triethylamine as mobile phase with a flow rate of 1.0 mL min-1 at 25°C. Online UV and optical rotation (OR) detection was performed at 254 nm. The parameters which have an effect on chiral separation were investigated, including mobile phase additive, organic modifier type and concentration, column temperature and flow rate. The method was tested for precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness. The present method is expected to be accurate, stable, rapid and sensitive and can be used for the determination of the enantiomeric purity of 2-(aminomethyl)-1-ethylpyrrolidine in bulk samples.