Clinical use of D-dimer testing

peer reviewedD-dimers are fibrin degradation products which are released during local or systemic activation of coagulation. D-dimer testing is widely used for the work-up of patients suspected of deep vein thrombosis or pulmonary embolism. Interpretation of D-dimer levels must take into account the sensitivity and specificity of the assay. The specificity is usually low, and increased D-dimer levels are encountered in many non-thrombotic situations. The sensitivity varies among the different testing methods and is maximal with ELISA assays. Highly sensitive assays allow exclusion of venous thromboembolism when D-dimer levels are normal, without further imaging. However, this diagnostic strategy may only be used safely when the clinical probability of thromboembolism is low to moderate. When combined with other tests of coagulation, D-dimer testing is also useful in the diagnosis of disseminated intravascular coagulation

Toxiques et analyses biologiques en toxicologie hospitalière

peer reviewe

The unintended consequence of SO₂ and NO₂ regulations over China: increase of ammonia levels and impact on PM_2,5 concentrations

International audienceAir pollution reaching hazardous levels in many Chinese cities has been a major concern in China over the past decades. New policies have been applied to regulate an-thropogenic pollutant emissions, leading to changes in atmospheric composition and in particulate matter (PM) production. Increasing levels of atmospheric ammonia columns have been observed by satellite during recent years. In particular , observations from the Infrared Atmospheric Sounding Interferometer (IASI) reveal an increase of these columns by 15 % and 65 % from 2011 to 2013 and 2015, respectively , over eastern China. In this paper we performed model simulations for 2011, 2013 and 2015 in order to understand the origin of this increase and to quantify the link between ammonia and the inorganic components of particles: NH + 4(p) /SO 2− 4(p) /NO − 3(p). Interannual change of meteorology can be excluded as a reason: year 2015 meteorology leads to enhanced sulfate production over eastern China, which increases the ammonium and decreases the ammonia content, which is contrary to satellite observations. Reductions in SO 2 and NO x emissions from 2011 to 2015 of 37.5 % and 21 % respectively, as constrained from satellite data, lead to decreased inorganic matter (by 14 % for NH + 4(p) + SO 2− 4(p) + NO − 3(p)). This in turn leads to increased gaseous NH 3(g) tropospheric columns by as much as 24 % and 49 % (sampled corresponding to IASI data availability) from 2011 to 2013 and 2015 respectively and thus can explain most of the observed increase