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- Dynamics of CO2, CH4, and N2O in Ria Formosa coastal lagoon (southwestern Iberia) and export to the Gulf of CadizPublication . Sierra, A.; Correia, Cátia; Ortega, T.; Forja, J.; Rodrigues, M.; Cravo, AlexandraA first characterization of greenhouse gases had been carried out to study their role and impact in a productive transitional coastal system of the southern Portugal – Ria Formosa lagoon. To this purpose, the partial pressure of CO2 (pCO2) and the concentration of dissolved CH4 and N2O have been measured. Two surveys were carried out during 2020, at low tide under typical conditions of Spring (March) and end of Summer (October). The samplings sites were distributed along the costal lagoon covering: i) inner areas with strong human impact (influence of different flows of treated wastewater discharges); and ii) main channels in connection with the main inlets to study the exchanges with the ocean. In general, the highest values of the three greenhouse gases were found at the inner studied areas, especially affected by the disposal of treated effluents from wastewater treatment plans, in October. The mean water - atmosphere fluxes of the CO2, CH4 and N2O are positive, showing that the study
- Stability of protein formulations at subzero temperatures by Isochoric CoolingPublication . Correia, Cátia; Tavares, Evandro; Lopes, Carlos; Silva, Joana G.; Duarte, Andreia; Geraldes, Vitor; Rodrigues, Miguel A.; Melo, EduardoOptimization of protein formulations at subzero temperatures is required for many applications such as storage, transport, and lyophilization. Using isochoric cooling (constant volume) is possible to reach subzero temperatures without freezing aqueous solutions. This accelerates protein damage as protein may unfold by cold denaturation and diffusional and conformational freedom is still present. The use of isochoric cooling to faster protein formulations was first demonstrated for the biomedical relevant protein disulfide isomerase A1. Three osmolytes, sucrose, glycerol, and l-arginine, significantly increased the stability of protein disulfide isomerase A1 at -20°C with all tested under isochoric cooling within the short time frame of 700 h. The redox green fluorescent protein 2 was used to evaluate the applicability of isochoric cooling for stability analysis of highly stable proteins. This derivative of GFP is 2.6-fold more stable than the highly stable GFP β-barrel structure. Nevertheless, it was possible to denature a fraction of roGFP2 at -20°C and to assign a stabilizing effect to sucrose. Isochoric cooling was further applied to insulin. Protein damage was evaluated through a signaling event elicited on human hepatocyte carcinoma cells. Insulin at -20°C under isochoric cooling lost 22% of its function after 15 days and 0.6M sucrose prevented insulin deactivation.