RESUMEN Un deslizamiento de tierra ocasionó un flujo de detritos a una escala de 0.3 miles de millones de metros cúbicos en la hondonada de Zhamunong en el río Yigong, el 9 de abril de 2000. El estudio de los factores deteterminantes y las dinámicas del proceso de este desastre, al igual que el estudio de la tendencia a futuro de eventos similares, ha sido de gran importancia científica e ingenieril. Inicialmente, se recolectó la información relacionada con la precipitación, terremotos y temperatura antes del deslizamiento y la información de onda sísmica después del evento. Luego se realizó un acercamiento multidimensional a la información para encontrar los factores, los procesos dinámicos y la tendencia del deslizamiento de tierra que desencadenó un flujo de detritos en Zhamunong, y que incluyó el índice de precipitación regular y los métodos de cálculo de aceleración sísmica, transformada rápida de Fourier, estabilidad de un deslizamiento, el método de las diferencias finitas MacCormack-TVD y el método de simulación numérica FLAC. Los resultados muestran lo siguiente: (1) Los factores de control principal del deslizamiento fueron el ciclo a largo plazo de congelación y descongelación, el ciclo de humedad y sequía, y un terremoto de magnitud media. (2) Con base en el espectro de vibración del terreno registrado durante este evento por la estación sísmica de Linzhi, las dinámicas pasan por el desarrollo del proceso de agrietamiento y articulación, el proceso de agrietamiento de las fracturas y deslizamiento, la traslación del deslizamiento de tierra en flujo de detritos, el movimiento y la deposición de estos detritos. (3) La densidad y el promedio de velocidad son de 2.0 tm-3 y 30.12 ms-1, y la descarga se muestra con el proceso de primero incremento y luego disminución. (4) Eventos similares pueden ocurrir en la hondonada de Zhamunong a futuro. Los resultados de la investigación son útiles para establecer los cimientos de estudios posteriores en los mecanismos de dinámicas y en la reducción de contramedidas de deslizamienos de tierra ocasionados por flujos de detritos.

ABSTRACT A disaster of a catastrophic landslide triggered a debris flow with a scale of 0.3 billion m3 that occurred in the Zhamunong gully of Yigong on April 9th, 2000. It is of great scientific and engineering significance to study the main controlling factors and dynamic processes of this disaster, and the future development trend of similar hazards. Firstly, the precipitation, earthquake and temperature data before the event and seismic wave data after the event were collect. Secondly, a multi-dimensional approach on the data for finding the factors, dynamic processes and tendency of a catastrophic landslide triggered a debris low in Zhamunong gully was applied, including the standard precipitation index and effective peak acceleration calculation methods, fast Fourier transform, landslide stability, MacCormack-TVD finite difference method and FLAC numerical simulation method. The results are shown as follows. (1) The main controlling factors of this disaster were the long-term freeze-thaw cycle, dry-wet cycle, and a middle magnitude earthquake. (2) Based on the ground vibration spectrum of 2000 disaster recorded by the Linzhi seismic station, the dynamic processes are the joint and crack development process, the crack fracture and sliding process, the landslide translating into the debris flow, the movement and deposition of the debris flow. (3) The density and the average velocity are 2.0 tm-3 and 30.12 ms-1, respectively, and the discharge is shown with the process of first increases and then decreases. (4) Similar catastrophic landslide triggered debris flow would happen in Zhamunong gully in the future. The research results are useful in establishing a foundation for further study on the dynamic mechanism and reduction countermeasures of a catastrophic landslide triggered by debris low.

A novel series of 2-ethyl-1-(4-substituted)phenyl-1H-imidazole derivatives was designed, synthesized, and tested for its antibacterial activity against various bacterial strains. Most of the synthesized compounds showed potent inhibition of several Gram-positive and Gram-negative bacterial strains with minimum inhibitory concentration (MIC) values in the range of 4-256 nmol mL-1 in vitro. The compound [2-ethyl-1-(4-pentoxy)phenyl-1H-imidazole] exhibited the most potent inhibitory activity. The MIC of this compound against S. aureus was found to be 8 nmol mL-1, smaller than that of the reference agents, ciprofloxacin and amoxicillin. Furthermore, the compound exhibited modest activity against several bacterial strains in a dose range of 8-256 nmol mL-1.

Plant growth regulating substances are involved in the physiological and metabolic processes of plants and enable them to cope with numerous environmental stresses. The effect of exogenously applied brassinolide (BR) with various concentrations (0.01, 0.1, and 1.0 mg L-1) was studied on morphological and physiological traits of Leymus chinensis (Trin.) Tzvelev under room and high temperatures in pots. The experimental results revealed that high temperature stress substantially perturbed growth, photosynthetic pigments, and root activity of L. chinensis; however, the deleterious effects of high temperature were partially ameliorated by the foliar application of BR. Compared to room temperature, high temperature stress decreased the plant height, leaf area, plant fresh and dry weight, chlorophyll a and b content, chlorophyll a/b ratio as well as root activity, while exacerbated the membrane damage as indicated by enhanced production of malondialdehyde (MDA). Accumulation of proline content, soluble protein and sugar content in L. chinensis improved by heat stress, compared with normal temperature; application of BR further improved their production thus aiding in the attainment of tolerance against heat stress. Elevated levels of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR) were observed under heat stress compared to room temperature, however, application of BR further proved beneficial in this regard. Our results indicated that BR could improve the growth and development of L. chinensis by enhancing the biosynthesis of photosynthetic pigments, osmolytes and antioxidant enzymes system in plants under both room and high temperature.

FUNDAMENTO: O programa de biogênese mitocondrial no coração parece apresentar remodelação adaptativa após estresse biomecânico e oxidativo. Os mecanismos adaptativos que protegem o metabolismo do miocárdio durante a hipóxia são coordenados, em parte, pelo óxido nítrico (NO). OBJETIVO: Observar a biogênese mitocondrial e expressão do óxido nítrico sintase (NOS) em corações de cardiopatia congênita com cianose; discutir a resposta mitocondrial à hipóxia crônica do miocárdio. MÉTODOS: Foram investigados 20 pacientes com defeitos cardíacos cianóticos (n = 10) ou acianóticos (n = 10). Foram estudadas amostras do miocárdio na via de saída ventricular direita, tomadas durante a operação. A análise morfométrica de mitocôndrias foi realizada por microscopia eletrônica de transmissão. A relação mtDNA/nDNA foi determinada com PCR em tempo real. Os níveis de transcrição da subunidade I da citocromo c oxidase (COXI), coativador-1α do receptor γ ativado por proliferador de peroxissoma (PGC-1α), o fator respiratório nuclear 1 (NRF1), e fator de transcrição mitocondrial A (Tfam) foram detectados por reação em cadeia da polimerase via transcriptase reversa (RT-PCR) ativado por fluorescência em tempo real. Os níveis proteicos de COXI e nNOS, iNOS e eNOS foram medidos por técnica de Western Blot. RESULTADOS: A densidade volumétrica mitocondrial (Vv) e a densidade numérica (Nv) foram significativamente elevadas em pacientes com cianose, em comparação com a cardiopatia congênita acianótica. MtDNA elevada e suprarregulação dos níveis de COXI, PGC-1 α, NRF1 e Tfam mRNA foram observadas em pacientes cianóticos. Os níveis de proteína de COXI e eNOS foram significativamente maiores no miocárdio de pacientes cianóticos que nos de acianóticos. Os níveis de transcrição do PGC-1α se correlacionam com os níveis de eNOS. CONCLUSÃO: A biogênese mitocondrial é ativada no miocárdio da via de saída ventricular na cardiopatia congênita com cianose, que poderia ser a resposta adaptativa à hipóxia crônica e possivelmente envolve suprarregulação da eNOS. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0)

BACKGROUND: Mitochondrial biogenesis program in heart appears to exhibit adaptive remodeling following biomechanical and oxidative stress. The adaptive mechanisms that protect myocardium metabolism during hypoxia are coordinated in part by nitric oxide (NO). OBJECTIVE: To observe mitochondrial biogenesis and nitric oxide synthase (NOS) expression in hearts of congenital heart disease with cyanosis, discuss mitochondrial response to chronic hypoxia in myocardium. METHODS: 20 patients with cyanotic (n=10) or acyanotic cardiac defects (n=10) were investigated. Samples from the right ventricular outflow tract myocardium taken during operation were studied. Morphometric analysis of mitochondria was performed with transmission electron microscope. Relative mtDNA/nDNA ratio was determined with real-time PCR. Cytochrome c oxidase subunit I (COXI), peroxisome-proliferator-activated receptor γ coactivator-1α (PGC-1α), nuclear respiratory factor 1 (NRF1), and mitochondrial transcription factor A (Tfam) transcript levels were detected by real-time fluorescent RT-PCR. COXI and nNOS, iNOS and eNOS protein levels were measured with western blot. RESULTS: Mitochondrial volume density (Vv) and numerical density (Nv) were significantly elevated in patients with cyanotic compared to acyanotic congenital heart disease. Elevated mtDNA and up-regulated COXI, PGC-1α, NRF1 and Tfam mRNA levels were observed in cyanotic patients. Protein levels of COXI and eNOS were significantly higher in the myocardium of cyanotic than of acyanotic patients. PGC-1α transcript levels correlated with the levels of eNOS. Conclusion: Mitochondrial biogenesis is activated in right ventricular outflow tract myocardium in congenital heart disease with cyanosis, which could be the adaptive response to chronic hypoxia and possibly involves eNOS up-regulation. (Arq Bras Cardiol. 2012; [online].ahead print, PP.0-0)