The management of postoperative pain in children with caudal blocks

Background: The aim of this study was to evaluate the pre-emptive analgesic effect and duration of postoperative analgesia after caudal blocks in children. Method: Forty-five children undergoing distal hypospadias surgery were assigned to group 1 (n = 23), and received caudal 0.25% bupivacaine 0.5 mg/kg and midazolam 0.05 mg/kg before the surgical incision. Group 2 (n = 22) received caudal 0.25% bupivacaine 0.5 mg/kg and midazolam 0.05 mg/kg at the end of surgery. Anaesthesia was induced with propofol and fentanyl and maintained with sevoflurane and nitrous oxide. Postoperative pain was rated on an objective paediatric pain scale. Results: The analgesic requirement was greater in the second group. Conclusion: Pre-emptive analgesia with caudal blocks may prevent the intensity and frequency of postoperative wound pain.South Afr J Anaesth Analg, 2011;17(6):376-37

Benzo(a)pyrene air concentrations and emission inventory in Lombardy region, Italy

Three years of particle phase B(a)P air concentration measurements in 13 sites in Lombardy (Italy) and a detailed emission inventory at the municipal scale for the whole region were used to infer the contribution of different sources to B(a)P atmospheric levels. The analyses of the weekly and monthly profiles of B(a)P concentrations, the cluster analysis and the comparison between the B(a)P/PM10 ratios in ambient air and in the emissions allowed identifying wood burning in small residential appliances as the key source for all the sites, except for those located in Milan. The highest values of the average B(a)P concentrations were not found in the wider urban areas, where in general the highest PM10 levels were registered. Regarding the seasonal variability, a marked reduction of both B(a)P concentrations and B(a)P/PM10 ratios was observed in the summer season. The cluster analysis of PM10 and B(a)P concentrations showed that the two pollutants tend to have a separate pattern; moreover the cluster analysis of B(a)P/PM10 ratios showed that the trend of this ratio split the stations depending on their location: plain area, piedmont and valley zones, and mountain sites. The dominance of the wood combustion highlighted by the emission inventory, originating from the residential sector and from pizzerias in the city of Milan, is consistent with the findings of other studies based on a source apportionment approach or air quality modeling, although some patterns of ambient B(a)P concentrations in one site were not adequately explained by the emission sources included in the emission inventory

Fattori di emissione dalla combustione di legna e pellet in piccoli apparecchi domestici

The aim of this study was to report emission factors of pollutants (i.e., carbon monoxide, nitrogen oxides, non-methane hydrocarbons, particulate matter, polycyclic aromatic hydrocarbons, dioxins) from biomass burning residential heating appliances. The influence of several factors such as biomass type, appliance and combustion cycle was investigated. Four manually fed (6-11 kW) firewood burning and two automatic wood pellets (8.8-25 kW) appliances were tested under real-world operating conditions in order to determine the actual environmental performance of the appliance. The experimental EFs were also compared with the values proposed by the European emission inventory guidebook used in the local inventory in order to evaluate their representativeness of real world emissions. The composite macropollutant EFs for manually fed appliances are: for CO 5858 g GJ-1, for NOx 122 g GJ-1, NMHC 542 g GJ-1, PM 254 g GJ-1, whereas emissions are much lower for automatic pellets appliances: CO 219 g GJ-1, for NOx 66 g GJ-1, NMHC 5 g GJ-1, PM 85 g GJ-1. The open fireplace appears to have very high emission factors, however traditional and advanced stoves show the highest overall CO EFs. Especially for the advanced stove real-world emissions are far worse than those measured under cycles used for type testing of residential solid fuel appliances. No great difference is observed for different firewood types in batch working appliances, diversely the quality of the pellets is observed to influence directly the emission performance of the automatic appliances. Benzo(b)fluoranthene is the PAH with the highest contribution (110 mg GJ-1 for manual appliances and 2 mg GJ-1 for automatic devices) followed by benzo(a)pyrene (77 mg GJ-1 for manual appliances and 0,8 mg GJ-1 for automatic devices)

Cumulant based parametric multichannel FIR system identification methods

Cataloged from PDF version of article.In this paper, ''least squares'' and recursive methods for simultaneous identification of four nonminimum phase linear, time-invariant FIR systems are presented. The methods utilize the second- and fourth-order cumulants of outputs of the four FIR systems of which the common input is an independent, identically distributed (i.i.d.) non-Gaussian process. The new methods can be extended to the general problem of simultaneous identification of three or more FIR systems by choosing the order of the utilized cumulants to be equal to the number of systems. To illustrate the effectiveness of our methods, two simulation examples are included

Particle number and mass exposure concentrations by commuter transport modes in Milan, Italy

There is increasing awareness amongst the general public about exposure to atmospheric pollution while travelling in urban areas especially when taking active travelling modes such as walking and cycling. This study presents a comparative investigation of ultrafine particles (UFP), PM10, PM2.5, PM1 exposure levels associated with four transport modes (i.e., walking, cycling, car, and subway) in the city of Milan measured by means of portable instruments. Significant differences in particle exposure between transport modes were found. The subway mode was characterized by the highest PM mass concentrations: PM10, PM2.5, PM1 subway levels were respectively about 2-4-3 times higher than those of the car and open air active modes (i.e. cycling and walking). Conversely, these latter modes displayed the highest UFP levels about 2 to 3 times higher than the subway and car modes, highlighting the influence of direct traffic emissions. The car mode (closed windows, air conditioning and air recirculation on) reported the lowest PM and UFP concentration levels. In particular, the open-air/car average concentration ratio varied from about 2 for UFP up to 4 for PM1 and 6 for PM10 and PM2.5, showing differences that increase with increasing particle size. This work points out that active mode travelling in Milan city centre in summertime results in higher exposure levels than the car mode. Walkers’ and cyclists’ exposure levels is expected to be even higher during wintertime, due to the higher ambient PM and UFP concentration. Interventions intended to re-design the urban mobility should therefore include dedicated routes in order to limit their exposure to PM and UFP by increasing their distance from road traffic