RESUMEN
Agriculture-based climate change mitigation may occur through enhancing the carbon sink or through reducing greenhouse gases (GHGs) emissions from agricultural residue treatment, as open burning of agricultural residues produces millions of tons of GHGs and air pollutants annually worldwide. Charring slashed biomass, termed as slash-and-char, has been considered as a promising alternative to open burning in dealing with agricultural residues such as rice straw. Previous studies, however, focused on relatively sophisticated slash-and-char systems, which could not be practiced easily by smallholder farmers in developing countries. Here we introduce a simple slash-and-char system to mitigate the environmental problems associated with open burning of rice straw. This system could convert 30.7% of the initial carbon in rice straw into biochar, much higher than that retained in the ash generated by open burning (3.95%). It could also cut GHGs, particulate matters and polycyclic aromatic hydrocarbons (PAHs) emissions by 26.9%, 99.0% and 99.4%, respectively. If open burning of rice straw was replaced by the slash-and-char, the annual emissions of GHGs, particulate matters and PAHs in China would decrease by at least 15.4â¯Tg, 1.51â¯Tg and 1.27â¯Gg, correspondingly. This decrease is nearly twice the size of China's estimated forest C sink (8.81â¯Tg).
Asunto(s)
Carbón Orgánico/química , Cambio Climático , Monitoreo del Ambiente , Gases de Efecto Invernadero/análisis , Agricultura/estadística & datos numéricos , Contaminantes Atmosféricos/análisis , Biomasa , Carbono , China , Contaminación Ambiental , Oryza , Material Particulado/análisis , Hidrocarburos Policíclicos Aromáticos/análisisRESUMEN
<p><b>OBJECTIVE</b>To investigate the clinical effects of the combined therapy of the Chinese medicine Compound Xuanju Capsule and vitamin E on sperm chromatin damage in idiopathic oligoasthenospermia.</p><p><b>METHODS</b>We assigned 50 infertile men with seminal abnormality to a control group (n = 26) and a trial group (n = 24) to receive vitamin E and the combined therapy of Compound Xuanju Capsule plus vitamin E, respectively, both treated for 3 months. Before and after the treatment, we detected semen routine parameters and sperm DNA fragmentation indexes (DFI) by computer aided semen analysis (CASA) and sperm chromatin structure assay (SCSA), and compared them between the two groups.</p><p><b>RESULTS</b>There was no obvious difference between the percentage of progressively motile sperm in the trial group and that in the control group (21.55 +/- 8.68 vs 21.47 +/- 11.53, P > 0.05). The trial group showed a significantly decreased sperm DFI after medication as compared with pre-medication (29.57 +/- 12.19 vs 34.09 +/- 10.32, P < 0.05).</p><p><b>CONCLUSION</b>The combined therapy of Compound Xuanju Capsule and vitamin E can effectively improve seminal quality and reduce sperm chromatin damage in infertile men with idiopathic oligoasthenospermia.</p>