In pancreas transplantation, complications can arise at each step of the process,from the initial selection of donors and recipients through the surgical techniqueitself and the post-operative period, when lifelong im...In pancreas transplantation, complications can arise at each step of the process,from the initial selection of donors and recipients through the surgical techniqueitself and the post-operative period, when lifelong immunosuppression isrequired. In the early steps, careful retrieval and preservation of the pancreas arecrucial for the viability of the organ and ultimate success of the transplant. Thepancreas is a low-flow gland, making it highly sensitive to transplantationconditions and presenting risk of pancreatitis due to periods of ischemia. The twogroups of donors - after brain death (DBD) or after cardiac arrest (DCD) - requiredifferent strategies of retrieval and preservation to avoid or reduce the risk ofcomplications developing during and after the transplantation. For DBD donortransplantation, multiorgan retrieval and cold preservation is the conventionaltechnique. Asystole donor (DCD) transplantation, in contrast, can benefit from thenewest technologies, such as hypothermic and especially normothermicpreservation machines (referred to as NECMO), to optimize organ preservation.The latter has led to an increase in the pool of donors by facilitating recuperationof organs for transplantation that would have been discarded otherwise.展开更多
This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.
Satellite constellations allow distributed tasks among multiple spacecraft,reducing mission time and enhancing objectives.Interest in constellations has increased due to reduced costs in satellite production and launc...Satellite constellations allow distributed tasks among multiple spacecraft,reducing mission time and enhancing objectives.Interest in constellations has increased due to reduced costs in satellite production and launch.A key step in constellation planning is its design,which determines the orbital distribution of the satellites.In this work,we apply the 2D Necklace Flower Constellations methodology to explore possible architectures for future missions around Titan.As a result of strong perturbations in regions near natural satellites and environmental restrictions on Titan,proposals for maintaining constellations to enhance data collection and prevent mutual collisions between the satellites involved are an important aspect to consider.Therefore,the proposed designs incorporate frozen orbits and repetition ground tracks in an initial dynamical model that includes the efects of the J2 and J3 perturbations.Analyses using a simplifed dynamic model,with a simple mean and a complete dynamic model,employing the IAS15 integrator from the Rebound package,show that,for the assumed perturbations,the proposed constellation confgurations maintain long-term ground-track coverage of the surface of Titan.The performance evaluation indicates that the methodology provides robust constellation geometries,supporting orbit control and mission feasibility for Titan exploration.展开更多
文摘In pancreas transplantation, complications can arise at each step of the process,from the initial selection of donors and recipients through the surgical techniqueitself and the post-operative period, when lifelong immunosuppression isrequired. In the early steps, careful retrieval and preservation of the pancreas arecrucial for the viability of the organ and ultimate success of the transplant. Thepancreas is a low-flow gland, making it highly sensitive to transplantationconditions and presenting risk of pancreatitis due to periods of ischemia. The twogroups of donors - after brain death (DBD) or after cardiac arrest (DCD) - requiredifferent strategies of retrieval and preservation to avoid or reduce the risk ofcomplications developing during and after the transplantation. For DBD donortransplantation, multiorgan retrieval and cold preservation is the conventionaltechnique. Asystole donor (DCD) transplantation, in contrast, can benefit from thenewest technologies, such as hypothermic and especially normothermicpreservation machines (referred to as NECMO), to optimize organ preservation.The latter has led to an increase in the pool of donors by facilitating recuperationof organs for transplantation that would have been discarded otherwise.
文摘This editorial describes the indications and technical aspects of the simultaneous retrieval of thoracic and abdominal organs in Maastricht III donors as well as the preservation of such organs until their implantation.
基金supported by Program CAPES-PDSE,process number 88881.982568/2024-01São Paulo Research Foundation(FAPESP)[grant number 2022/11783-5]+1 种基金supported by Grant PID2024-156002NB-I00 funded by MICIU/AEI/10.13039/501100011033/FEDER,UEthe Aragón Government and European Social Fund(E24_23R).
文摘Satellite constellations allow distributed tasks among multiple spacecraft,reducing mission time and enhancing objectives.Interest in constellations has increased due to reduced costs in satellite production and launch.A key step in constellation planning is its design,which determines the orbital distribution of the satellites.In this work,we apply the 2D Necklace Flower Constellations methodology to explore possible architectures for future missions around Titan.As a result of strong perturbations in regions near natural satellites and environmental restrictions on Titan,proposals for maintaining constellations to enhance data collection and prevent mutual collisions between the satellites involved are an important aspect to consider.Therefore,the proposed designs incorporate frozen orbits and repetition ground tracks in an initial dynamical model that includes the efects of the J2 and J3 perturbations.Analyses using a simplifed dynamic model,with a simple mean and a complete dynamic model,employing the IAS15 integrator from the Rebound package,show that,for the assumed perturbations,the proposed constellation confgurations maintain long-term ground-track coverage of the surface of Titan.The performance evaluation indicates that the methodology provides robust constellation geometries,supporting orbit control and mission feasibility for Titan exploration.
