Nitrification kinetics, N2O emission, and energy use in intermittently aerated hybrid reactor under different organic loading rates.

This study investigated the impact of intermittent aeration strategies and reduction in the reactor's organic and nitrogen loading rates on the course of particular stages of the nitrification process, as well as energy consumption and N2O emissions in a hybrid reactor with nitrification/denitrification. Each of the analysed series revealed the greatest ammonia oxidation activity in activated sludge flocs. The highest activity of nitrite nitrogen oxidation was demonstrated in the case of biofilm. A reduction in the reactor's organic and nitrogen loading rate value had a greater effect on changes in the activity of ammonia-oxidizing bacteria than nitrite-oxidizing bacteria. In a system where the operation of air pumps was controlled through switching them and off according to the adopted ratio between non-aerated and aerated sub-phase times and the assumed oxygen concentration, a reduction in the duration of aerated sub-phases caused no decrease in energy use for aeration. Lower N2O emission was recorded when the reactor operated with a longer duration of aerated sub-phases. Supplementary Information: The online version contains supplementary material available at 10.1007/s13762-022-04715-6.

Organoids as preclinical models to improve intraperitoneal chemotherapy effectiveness for colorectal cancer patients with peritoneal metastases: Preclinical models to improve HIPEC.

BACKGROUND: Peritoneal metastases (PM), corresponding to tumor implants into the peritoneal cavity, are associated with impaired prognosis and low responsiveness to systemic chemotherapy. A new therapeutic approach has dramatically changed the prognosis of patients with PM from colorectal cancer (CRC), consisting in the association of a complete cytoreductive surgery followed by intraperitoneal chemotherapy associated to hyperthermia (HIPEC). Many drugs have been administered intraperitoneally, but no clear consensus has been approved. Therefore, relevant preclinical models are essentials for the efficient translation of treatments option into affected patients. METHOD: Organoids, the last generation of preclinical models, were used to rationalize and improve intraperitoneal chemotherapy. We tested several cytotoxics, combination, effect of hyperthermia, exposure duration and frequency. RESULTS: Organoids were a representative model of response to chemotherapies used for the treatment of PM from CRC; 460mg/m2 of oxaliplatin being the most efficient cytotoxic treatment. Repeated incubations with oxaliplatin; mimicking cycles of intraperitoneal treatment, resulted in an increased efficacy. CONCLUSION & DISCUSSION: Organoids are relevant models to study the chemosensitivity of peritoneal metastases from CRCs. These models could be used for large scale drug screening strategies or personalized medicine, for colorectal carcinoma but also for PM from other origins.