RESUMEN
Aerosol liquid water (ALW) can serve as an aqueous-phase medium for numerous chemical reactions and consequently enhance the formation of secondary aerosols in a highly humid atmosphere. However, the aqueous-phase formation of secondary organic aerosols (SOAs) is not well understood in the Indian regions, particularly in tropical peninsular India. In this study, we collected total suspended particulate samples (n = 30) at a semiarid station (Ballari; 15.15°N, 76.93°E; 495 m asl) in tropical peninsular India during the winter of 2016. Homologous series of dicarboxylic acids (C2-C12), oxoacids (ωC2-ωC9), pyruvic acid (Pyr), and glyoxal (Gly) were determined by employing a water-extraction of aerosol and analyzed using capillary gas chromatography (GC). Results show that oxalic acid (C2) was the most abundant organic acid, followed by succinic (C4), malonic (C3), azelaic (C9), and glyoxylic (ωC2) or phthalic (Ph) acids. Total diacids-C accounted for 1.7-5.8 % of water-soluble organic carbon (WSOC) and 0.6-3.6 % of total carbon (TC). ALW, estimated from the ISORROPIA 2.1 model, showed a strong linear relationship with sulfate (SO42-), C2, C3, C4, ωC2, Pyr, and Gly. Based on molecular distribution, specific mass ratios (C2/C3, C2/C4, C2/Gly, and Ph/C9), linear relationships among the measured organic acids, ALW, organic (levoglucosan and oleic acid), and inorganic (SO42-) marker compounds, we emphasize that diacids and related organic compounds, especially C2, majorly form via aqueous-phase oxidation of precursor compounds including aromatic hydrocarbons (HCs) and unsaturated fatty acids (FAs) originated from biomass burning and combustion-related sources. The present study demonstrates that sulfate driven ALW largely enhances the formation of SOAs via the aqueous-phase reactions over tropical peninsular India during winter.
RESUMEN
OBJECTIVE: To investigate whether hyaluronidase (Hyalase) is a useful and justified addition to haematoma block for pain relief. METHODS: The study was a randomised double blind trial of 33 consecutive patients attending the accident and emergency department for manipulation of distal radius fracture under haematoma block. Control patients received 1% lignocaine; the treatment group received 1% lignocaine plus 1500 IU hyaluronidase. Manipulation occurred 10 minutes after instituting the block. RESULTS: 16 patients received hyaluronidase, 17 received lignocaine only. One patient with unsuccessful manipulation was excluded. There was no significant difference between the two groups for any of three methods of pain assessment (P > 0.05, Mann Whitney). CONCLUSIONS: The addition of hyaluronidase does not increase the efficacy of the haematoma block when 10 minutes are allowed to elapse before manipulation, and the increased cost of adding (and risk of allergy) is not justified by any theoretical increased speed of analgesia.