RESUMEN
Selection of appropriate residue application method is essential for better use of biomass for soil and environmental health improvement. A laboratory incubation experiment was conducted for 75 days to investigate C and N mineralization of residues of soybean (Glycine max L.), chickpea (Cicer arietinum L.), maize (Zea mays L.), and wheat (Triticum aestivum L.) placed on the soil surface and incorporated into the soil. The residue of soybean and chickpea had a greater decomposition rate than that of maize and wheat, despite of their placements. Higher rate of decomposition of the residue of soybean and chickpea was recorded when it was kept on the soil surface while soil incorporation of residue of wheat and maize resulted in faster decomposition. Therefore, these findings could be used as guidelines for management of crop residue application in farmland to improve soil and environmental quality.
Asunto(s)
Agricultura/métodos , Carbono/química , Productos Agrícolas/química , Nitrógeno/química , Suelo/química , Biomasa , Carbono/análisis , Productos Agrícolas/metabolismo , Monitoreo del Ambiente , Nitrógeno/análisis , Glycine max , Triticum/metabolismo , Zea mays/químicaRESUMEN
A prospective study of 500 consecutive cholecystectomies was initiated with the introduction of laparoscopic cholecystectomy. Laparoscopic cholecystectomy was attempted in 96% of patients presenting with primary gallbladder disease and was completed in 95%. There were no deaths or bile duct injuries. Two patients undergoing laparoscopic cholecystectomy were transfused for postoperative bleeding, and only one patient required reoperation for any reason. A prospective study showed reduced operating time (20 minutes) and patient charges ($546) using electrosurgical dissection compared with laser. Reusable trocars were used without any associated injury or morbidity. An effective strategy for selective cholangiography was developed based on patient history, liver enzymes, and common duct diameter. In conclusion, laparoscopic cholecystectomy appears to be a safe operation. The cost-effectiveness of laparoscopic cholecystectomy can be enhanced ($1,271) with no loss of patient benefit using the combination of electrosurgery, reusable trocars, and selective cholangiograms in low-risk patients.