Variability of PM10 in industrialized-urban areas. New coefficients to establish significant differences between sampling points.

One of the main problems that arise in the assessment of air quality in an area is to estimate the number of representative sampling points of each microenvironment within it. We present a new model that reduces the variability and increases the quality of the comparison of the sampling points. The study is based on the comparison between a city in eastern Spain, Vila-real, a macro city in México, Monterrey and the Piemonte region regarding the assessment of PM10 in microenvironments. Vila-real is located in the province of Castellón. This province is a strategic area in the framework of European Union (EU) pollution control. On the other hand, Monterrey in México, located in the northern state of Nuevo León, has several problems with particulate material in the atmosphere produced by the extraction of building materials in the hill that surround the city. Finally, the Piemonte region, which is located in the north of Italy, has to be in consideration due to higher concentrations of PM10 in the Po river basin. In the case of Vila-real the PM10 samples were collected by a medium volume sampler according to European regulations. Particle concentration levels were determined gravimetrically (EN 12341:1999). In the case of Monterrey the PM10 concentrations were determined by Beta Ray Attenuation according to US-EPA regulations. In the Piemonte region, the average concentration of PM10 was also obtained by means of the Beta Ray Attenuation as well as using gravimetric instruments. The methodology carried out in this paper is a useful tool for developing future Air Quality Plans in other industrialised areas.

Assesment of PM10 pollution episodes in a ceramic cluster (NE Spain): proposal of a new quality index for PM10, As, Cd, Ni and Pb.

Environmental pollution control is one of the most important goals in pollution risk assessment today. In this sense, modern and precise tools that allow scientists to evaluate, quantify and predict air pollution are of particular interest. Monitoring atmospheric particulate matter is a challenge faced by the European Union. Specific rules on this subject are being developed (Directive 2004/107/EC, Directive 2008/50/EC) in order to reduce the potential adverse effects on human health caused by air pollution. Air pollution has two sources: natural and anthropogenic. Contributions from natural sources can be assessed but cannot be controlled, while emissions from anthropogenic sources can be controlled; monitoring to reduce this latter type of pollution should therefore be carried out. In this paper, we describe an air quality evaluation in terms of levels of atmospheric particles (PM10), as outlined by European Union legislation, carried out in an industrialised Spanish coastal area over a five-year period with the purpose of comparing these values with those of other areas in the Mediterranean Basin with different weather conditions from North of Europe. The study area is in the province of Castellón. This province is a strategic area in the frame work of European Union (EU) pollution control. Approximately 80% of European ceramic tiles and ceramic frit manufacturers are concentrated in two areas, forming the so-called "ceramics clusters"; ones in Modena (Italy) and the other in Castellón. In this kind of areas, there are a lot of air pollutants from this industry then it is difficult to fulfill de European limits of PM10 so it is necessary to control the air quality in them. The seasonal differences in the number of days in which pollutant level limits were exceeded were evaluated and the sources of contamination were identified. Air quality indexes for each pollutant have been established to determine easily and clearly the quality of air breathed. Furthermore, in accordance with Directive 2008/50/EC, an Air Quality Plan is proposed to protect human health, and the environment as a whole, in the study area. General and specific corrective measures of main emission sources are provided. A strategy for air pollution management is thus presented.

Enantiomeric resolution of bupivacaine by high-performance liquid chromatography and chiroptical detection.

This work reports a new analytical procedure for the separation and determination of the enantiomers of bupivacaine and the determination of the enantiomeric purity. The isomers were separated using a Chirex 3020 (250 mm x 4.6 mm) with a mobile phase of n-hexane:dichloroethane:ethanol (82:9:9, v/v/v) at a flow-rate of 1 ml min(-1) and UV, polarimetric and circular dichroism (CD) detection. Obtained retention times were 5.93 and 7.53 min (R and S) with a resolution of Rs=2.36. Precisions (RSD) were 1.83 and 2.02% (CD detection) and 3.07 and 1.26% (UV detection) for R- and S-enantiomers, respectively (at 10 microg level). Detection limits were 0.5 and 0.5 microg (R and S) with CD detection, and 0.9 and 0.3 microg with UV detection. Polarimetric detection was inadequate to perform a quantitative method at similar concentration ranges as UV and CD because of poor sensitivity. A procedure for determination of enantiomeric purity using a conventional chromatographic column (RP18, Luna) coupled to a CD detector and anisotropy factor (CD/UV) as analytical signal was also developed. Obtained results show that RSDs of 6.7-1.6% were obtained in the range of 0-100% enantiomeric purity.

Potassium depolarization-induced cAMP stimulates somatostatin mRNA levels in cultured diencephalic neurons.

In the nervous system, signals transmitted across synapses are known to regulate gene expression in the postsynaptic cells. This process often involves membrane depolarization and subsequent elevation of intracellular Ca(2+). We have previously demonstrated in fetal cerebrocortical cells, that somatostatin (SS) mRNA levels can be induced by depolarizing agents such as high potassium concentrations and veratridine (VTD), and that these effects are calcium dependent. SS expression is regulated by cAMP, and in the cerebral cortex adenylate cyclase activity is regulated through fluctuations in intracellular Ca(2+) concentrations. The present experiments were undertaken to determine the mechanism by which calcium upregulates the levels of SS mRNA. Cerebrocortical cells from 17-day-old fetuses were exposed to the different agents for 24 h and the levels of SS mRNA were measured by Northern blot. Incubation of cells with the calcium channel antagonist nifedipine (Nf), the calcium chelating agent EGTA, calcium free KRB and the calcium calmodulin inhibitors trifluoroperazine (TFP) and the napthelene sulfonamide, W7, resulted in the inhibition of K(+)-induced SS mRNA levels. K(+)-evoked depolarization increased the intracellular concentration of cAMP and this effect was antagonized by verapamil (VPM). Forskolin (Fk) provoked a higher increment in cAMP concentration than potassium, although the induction of SS mRNA was more evident following K(+) depolarization indicating a lack of correlation between levels of cAMP and induction of SS mRNA. The role of K(+)-induced cAMP on the increment of SS mRNA that occurred upon membrane depolarization was further explored with the inhibitor of protein kinase A (PKA), Rp cAMP whose presence significantly reduced depolarization-induced SS mRNA levels. This study confirms that Ca(2+) influx is required for K(+)depolarization-induced stimulation of cAMP whereby the increment of SS mRNA is partly produced.