ABSTRACT Expressways in China are developing rapidly, as is traffic pollution, which is one of the major sources of urban pollution. In this study, we chose the greenbelt in the idle zone near the Lin’an toll station along the Hang Rui expressway as our sampling area. Five points in the sampling area along Qianjin road were marked vertically at distances of 0, 15, 30, 45 and 60 m to monitor concentrations of PM2.5 and learn the varying patterns of these concentrations and influencing factors. The results showed that in spring (March, April and May), the average PM2.5 concentrations in the greenbelt were 32.56 ± 22.51, 77.71 ± 32.11 and 64.15 ± 29.00 μg m-3, respectively. The ranking of concentrations at different monitoring points in the same period was 0 > 15 > 60 > 30 > 45 m. The average concentrations in winter (November and December 2017, and February 2018) were 33.56 ± 9.34, 60.78 ± 17.67 and 124.71 ± 43.19 μg m-3, respectively. However, the ranking of concentrations at different monitoring points in the same period revealed some differences. Except at 0 m, the concentrations of PM2.5 in the other four positions were higher in winter than in spring. The reduction rate at 45 m reached its maximum in both spring and winter. PM2.5 concentrations were significantly correlated with meteorological factors, the structure of the plant community and traffic flow. PM2.5 concentrations were negatively correlated with temperature, positively correlated with relative humidity and was not significantly correlated with wind speed. The correlations of PM2.5 concentrations with the canopy density and degree of porosity differed greatly due to different seasons, and concentrations were significantly correlated with the amount of traffic flow, especially when there were large trucks.

RESUMEN Las vías rápidas se están desarrollando con gran celeridad en China y junto con ellas la contaminación por tráfico, que es una de las mayores fuentes de contaminación urbana. En este estudio se eligió como área de muestreo el cinturón verde ubicado en la zona de amortiguamiento cercana a la estación de peaje Lin’an en la autopista Hang Rui. Se seleccionaron cinco puntos verticales a lo largo de la carretera Qianjin a distancias de 0, 15, 30, 45 y 60 m para monitorear las concentraciones de PM2.5 y conocer tanto sus patrones de variaciones como los factores que influyen en ellos. Los resultados mostraron que durante la primavera (marzo, abril y mayo) las concentraciones promedio de PM2.5 en el cinturón verde fueron de 32.56 ± 22.51, 77.71 ± 32.11 y 64.15 ± 29.00 μg m-3, respectivamente. La categorización de las concentraciones en diferentes puntos de monitoreo en el mismo periodo fue de 0 > 15 > 60 > 30 > 45 m. Las concentraciones promedio en invierno (noviembre y diciembre de 2017, y febrero de 2018) fueron de 33.56 ± 9.34, 60.78 ± 17.67 y 124.71 ± 43.19 μg m-3, respectivamente. Sin embargo, la categorización de las concentraciones en diferentes puntos de monitoreo mostró algunas diferencias. Con excepción del punto de muestreo ubicado a 0 m, las concentraciones de PM2.5 en los otros cuatro puntos fueron superiores en invierno que en primavera. La tasa de reducción a una distancia de 45 m alcanzó su máximo tanto en primavera como en invierno. Las concentraciones de PM2.5 tuvieron una correlación significativa con factores meteorológicos, la estructura de la comunidad vegetal y el flujo de tráfico; asimismo, tuvieron una correlación negativa con la temperatura, correlación positiva con la humedad relativa, y correlación no significativa con la velocidad del viento. Las correlaciones de PM2.5 con la densidad y el grado de porosidad de la cubierta vegetal difirieron de manera considerable como resultado de la estacionalidad, y las concentraciones se correlacionaron significativamente con la densidad del flujo de tráfico, especialmente en presencia de camiones pesados.

Semisolid slurry of A356 aluminum alloy was prepared by Self-Inoculation Method (SIM), and the microstructures and solidification behavior of rheo-forming process in different forming processes were researched. The results indicate that semisolid slurry of A356 aluminum alloy can be prepared by Self-Inoculation Method at 600ºC. Primary α-Al particles with fine and spherical morphology are uniformly distributed when the isothermal holding time of slurry is 3 min. The different forming processes for semisolid rheo-forming can be regarded as the effect of cooling rate on rheo-forming. The primary particle sizes and shape factors are gradually increasing with the increase of cooling rate. The sizes of secondary particles are gradually increasing with the decrease of cooling rate, and the amount of secondary particles in the same areas are gradually decreasing with the decrease of cooling rate. The morphologies of eutectic Si are gradually coarsening from fibrous to needle-like in different forming processes, while the sizes and the lamellar spacing of the eutectic Si are gradually increasing with the decrease of cooling rate. The mechanical properties of the semisolid forming components are gradually increasing with the increase of cooling rate and forming pressure.

Resumo Fundamentos: A revascularização do miocárdio sem circulação extracorpórea (CRM sem CEC) é um dos tratamentos padrão para a doença arterial coronária (DAC), enquanto que a revascularização coronária híbrida (RCH) é uma estratégia de revascularização em evolução. No entanto, a diferença nos resultados entre eles ainda não está clara. Objetivo: Realizamos uma meta-análise para comparar os resultados a curto e médio prazo da RCH versus a CRM sem CEC para o tratamento de DAC de múltiplos vasos ou artéria principal esquerda. Métodos: Pesquisamos as bases de dados PubMed, EMBASE, Web of Science e Cochrane para identificar estudos relacionados e realizamos uma meta-análise de rotina. Resultados: Nove estudos com 6121 pacientes foram incluídos na análise. Não houve diferença significativa na taxa de eventos cardíacos e cerebrovasculares adversos maiores de curto prazo (ECCAM) (RR de 0,55, IC de 95% 0,30-1,03, p = 0,06) ou mortalidade (RR: 0,51, IC 95%: 0,17-1,48, p = 0,22). A RCH requereu menos tempo de ventilação (DMP -0,36; IC de 95%: -0,16 -0,55-, p < 0,001), tempo de UTI (DMP: -0,35, IC de 95%: -0,58- -0,13, p < 0,01), estadia hospitalar (DMP: -0,29; IC de 95%: -0.50 - -0,07, p < 0,05) e taxa de transfusão de sangue (RR: Cl 0,57, 95% de 0,49-0,67, p < 0,001), mas necessitou mais tempo de cirurgia (DMP): 1,29, IC de 95% 0,54-2,05, p < 0,001) e custos de hospitalização (DMP: 1,06, 95 %: 0,45-1,66, p < 0,001). O grupa RCH tinha uma taxa mais baixa de ECCAM a médio prazo (RR de 0,49, IC de 95% 0,26-0,92, p < 0,05), mas uma taxa mais elevada a médio prazo em revascularização de vaso alvo (RVA, RR: 2,20, IC 95%: 1,32). 3,67, p < 0,01). Conclusões: A RCH teve mortalidade e morbidade semelhantes no curto prazo comparada ao CRM sem CEC. A RCH diminuiu o tempo de ventilação, a internação na UTI, a internação hospitalar, a taxa de transfusão de sangue e o aumento do tempo de operação e os custos de hospitalização. A RCH tem uma taxa ECCAM mais baixa no médio prazo, enquanto a CRM sem CEC se mostra melhor em RVA a médio prazo.

Abstract Background: Off-pump coronary artery bypass grafting (OPCAB) is one of the standard treatments for coronary artery disease (CAD) while hybrid coronary revascularization (HCR) represents an evolving revascularization strategy. However, the difference in outcomes between them remains unclear. Objective: We performed a meta-analysis to compare the short-term and mid-term outcomes of HCR versus OPCAB for the treatment of multivessel or left main CAD. Methods: We searched the PubMed, EMBASE, Web of Science and Cochrane databases to identify related studies and a routine meta-analysis was conducted. Results: Nine studies with 6121 patients were included in the analysis. There was no significant difference in short-term major adverse cardiac and cerebrovascular event (MACCE) rate (RR: 0.55, 95% CI: 0.30-1.03, p = 0.06) or mortality (RR: 0.51, 95% CI: 0.17-1.48, p = 0.22). HCR required less ventilator time (SMD: -0.36, 95% CI: -0.55- -0.16, p < 0.001), ICU stay (SMD: -0.35, 95% CI: -0.58 - -0.13, p < 0.01), hospital stay (SMD: -0.29, 95% CI: -0.50- -0.07, p < 0.05) and blood transfusion rate (RR: 0.57, 95% CI: 0.49-0.67, p < 0.001), but needed more operation time (SMD: 1.29, 95% CI: 0.54-2.05, p < 0.001) and hospitalization costs (SMD: 1.06, 95% CI: 0.45-1.66, p < 0.001). The HCR group had lower mid-term MACCE rate (RR: 0.49, 95% CI: 0.26-0.92, p < 0.05) but higher rate in mid-term target vessel revascularization (TVR, RR: 2.20, 95% CI: 1.32-3.67, p < 0.01). Conclusions: HCR had similar short-term mortality and morbidity comparing to OPCAB. HCR decreased the ventilator time, ICU stay, hospital stay, blood transfusion rate and increased operation time and hospitalization costs. HCR has a lower mid-term MACCE rate while OPCAB shows better in mid-term TVR.

O objetivo deste trabalho foi investigar a relação entre variações em uma comunidade de plantas e variações nas propriedades físicas do solo e na disponibilidade de água, durante uma sucessão de alfafa (Medicago sativa L.) por vegetação natural, no Platô Loess, na China. Dados de uma sucessão de 32 anos foram examinados e índices vegetativos foram comparados em relação às variações de densidade do solo e do armazenamento de água no solo. A produção de alfafa aumentou aproximadamente por sete anos, e então decresceu, e a alfafa foi substituída por uma comunidade natural dominada pela Stipa bungeana, que começou a crescer vigorosamente dez anos após a semeadura da alfafa. A densidade do solo aumentou com o tempo, e a deterioração da alfafa se deu principalmente em razão da redução severa da água armazenada no solo, que atingiu o mínimo quando a degradação da alfafa começou. Os resultados indicam que o consumo de água pela alfafa poderia ser reduzido pela redução na densidade de plantas e que a recarga de água no solo poderia ser facilitada pela rotação entre a alfafa e outras culturas, vegetação natural ou solo nu.

The objective of this work was to investigate the relationship between changes in the plant community and changes in soil physical properties and water availability, during a succession from alfalfa (Medicago sativa L.) to natural vegetation on the Loess Plateau, China. Data from a succession sere spanning 32 years were collated, and vegetative indexes were compared to changes related to soil bulk density and soil water storage. The alfalfa yield increased for approximately 7 years, then it declined and the alfalfa was replaced by a natural community dominated by Stipa bungeana that began to thrive about 10 years after alfalfa seeding. Soil bulk density increased over time, but the deterioration of the alfalfa was mainly ascribed to a severe reduction in soil water storage, which was lowest around the time when degradation commenced. The results indicated that water consumption by alfalfa could be reduced by reducing plant density. The analysis of the data also suggested that soil water recharge could be facilitated by rotating the alfalfa with other crops, natural vegetation, or bare soil.