On the origin of the highest ozone episodes in Spain

The 2000-2015 occurrences of the highest ozone (O₃) pollution episodes in Spain were evaluated to investigate their origin. To this end, data series available for urban and regional background (UB and RB), traffic (TR) and industrial (IN) sites were analysed separately and intercompared. Results evidenced that during these 16years mean O₃ levels in the RB sites did not change significantly, and remained constantly high. However, there is a clear increase at the TR and UB sites. Although sensitivity analysis is needed to interpret the cause of this increasing trend, this might be caused probably by the lower O₃ titration intensity due to the preferential abatement of NO vs NO₂, as supported from the neutral trend of O_X (NO₂+O₃) at these sites. We found that the exceedances of the hourly information threshold for O₃ (>180μg/m³) are recorded mostly at UB and IN sites located in seven areas of Spain (specific hotspots or at the tail end of large urban plumes), and that these increased during summer heatwaves (i.e. 2003 and 2015). Although the external contribution of regional-to-subcontinental transported O₃ might be relevant during the highest O₃ episodes in the Western Mediterranean, our results evidenced that in the above specific areas, regional-local O₃ production decisively contributes to the exceedances of the information threshold. Also that the human protection threshold and the AOT40 are more frequently exceeded in the Central, Southern and Mediterranean sides of the Iberian Peninsula. The design of effective episode abatement measures is quite complex in those conditions, due to both the nonlinearity of the chemical processes of O₃ formation and destruction, and to the interplay with the complex meteorological setting, causing frequent recirculation and in situ aging of air masses. However, the combination of meteorological forecasting of the main recirculation processes and sensitivity analysis of NO_X/VOC emission abatement measures might be powerful tools to evaluate the effectiveness of potential O₃ mitigation strategies. Finally we would like to highlight that the current UB, RB, IN and TR classification (somewhat subjective) is not adequate to interpret the origin of O₃ exceedances in complex areas of Southern Europe. Thus, a UB station recording exceedances, and located in a small city in the tail end of an urban plume of a large city, receives not only the contribution from its own UB, but mainly from the specific high O₃ RB caused by the urban plume transport.

Comparison of the efficacy and bioequivalence of two oral formulations of tiludronate in the treatment of Paget's disease of bone

Tiludronate, an oral bisphosphonate used to treat Paget's disease of bone, is currently being studied as a treatment for osteoporosis. A multicenter, open-label, parallel-group study was performed to compare the efficacy of two tablet formulations of tiludronate in the treatment of Paget's disease. Eighty-eight patients with active Paget's disease were recruited. The diagnosis was based on radiologic evidence of bone lesions, and all patients included in the study had serum alkaline phosphatase (SAP) levels equal to or more than twice the upper normal value of the local laboratory that assayed the sample. Each patient received treatment with oral tiludronate 400 mg/d for 84 +/- 2 days; 39 patients received the previously tested tablet formulation 3C1, and 49 patients received formulation 9O1, which is prepared using an improved manufacturing technique. The objective of this study was to determine whether the two formulations have an equivalent therapeutic effect, the primary end point being SAP levels in both groups after 3 months of treatment. This equivalence is commonly assessed by comparing pharmacokinetic data; however, in previous studies of tiludronate, large intra-individual variability prevented statistically valid comparisons of the data. Therefore, in addition to pharmacokinetic data, biochemical and clinical response data were collected during the trial. The secondary objectives of the trial were to measure the plasma levels and to assess the efficacy and safety of the two tiludronate formulations. The relative pharmacologic activities of the two formulations were assessed by comparison of the confidence intervals of levels of SAP at monthly intervals. After 3 months of treatment, the 90% confidence interval of the difference between the formulations was included in the reference confidence interval. These findings suggest that the 9O1 and 3C1 formulations did not show a significant difference in therapeutic activity. Furthermore, after 3 months of treatment, the frequency of normalization of SAP levels was 30.6% in the 9O1 treatment group and 28.2% in the 3C1 treatment group. The percentage of patients responding to treatment (defined as a decrease in SAP levels of at least 50% from baseline) was 67.3% in the 9O1 treatment group and 69.2% in the 3C1 treatment group. Statistical analyses performed on the maximum and minimum plasma concentrations of tiludronate showed no significant differences between the two formulations. In this trial, the two tablet formulations of tiludronate demonstrated therapeutic and pharmacokinetic equivalence.

New approach to vascular access revascularisation: the Hydrolyser Thrombectomy Catheter

The appearance of thrombosis in the vascular access (VA) for haemodialysis (HD) is one of the most important complications of HD, with a great impact on the survival of definitive VA-both autologous internal arteriovenous fistulae (IAVFs) and prostheses (Gore-tex).