Validation activities of a microprocessor for space applications

Launching a satellite is a high cost mission. However, nowadays, low-mass and low-cost satellites are being developed to reduce mission costs, above all the scientific and educative ones. This thesis focuses on the study of one of the components of a femtosatellite designed and build at EETAC university. The component to be analyzed is the microprocessor. In order to meet the low cost requirements, those satellites must be built with COTS technology. The positive point of that technology is that it is affordable to anyone, in terms of economical aspects and readily availability. Nevertheless, it is not optimum to operate in the space environment, since it is not qualified and thus, its survivability is unknown. Once the existent problem of the COTS technology has been presented, the goal of this thesis is to achieve a certain space qualification level. The microprocessor Atmega 168 will be the analyzed COTS component. Future missions and potential applications are firstly analyzed in order to space- qualify the microprocessor. After that, the issues regarding to all the mission phases (pre-launch, launch, and orbit operations) are studied. This will help us to determine what are the harmful effects on the microprocessor. When all the effects that the microprocessor must deal with have been analyzed, the steps to obtain a certain space qualification are addressed. The basic procedures are defined by the corresponding TRA for each TRL. From TRA documentation, the proper tests and simulations are chosen within a realistic environment. The tests are a thermal vacuum laboratory experiment and a radiation exposure analysis, simulating the Van Allen belts, using the commercial software packages FLUKA and SPENVIS. Theoretical background to support the experiments and simulations are previously provided. Finally, after testing the microprocessor, the TRL level reached by it can be determined. Therefore, TRL 1 and TRL 2 are clearly achieved, since potential applications of the physical concept are developed. Given all that, we can conclude that the microprocessor has achieved TRL level 3. It passed all the tests and simulations conducted in this thesis. Nonetheless, TRL 4 is not achievable because Integration between satellite components must be tested. The integration of components is out of the scope of this thesis.Català: Enviar un satèl·lit a l’espai és una missió d’alt cost. No obstant, actualment, s’estan construint satèl·lits de massa i mida molt més reduïda per abaratir els costos d’algunes missions espacials, sobretot, les que tenen caire científic i educatiu. Aquesta tesis es focalitza en l’estudi d’un dels components del femtosatèl·lit creat per l’EETAC, el microprocessador. Per poder dur a terme el requeriment de baix cost, aquets satèl·lits usen tecnologia COTS. Els punts positius d’aquesta tecnologia es que és més econòmica que la usada en satèl·lits comercials i és a l’abast de tothom. Per altra banda, els seu punt negatius es que no és una tecnologia òptima per operar en espai, ja que no està qualificada i per tant no sabem la seva fiabilitat en aquest ambient. Un cop presentat el problema existent amb la tecnologia COTS, l’objectiu d’aquesta tesis és assolir un cert nivell de qualificació espacial. La tecnologia COTS que està sotmesa a anàlisis és el microprocessador ATmega 168. Per poder qualificar el microprocessador, primerament s’analitzen les seves possibles aplicacions i futures missions. Després, es realitza un anàlisis de tota la problemàtica que comporten les diferents fases que experimenta el microprocessador: pre-llançament, llançament i operació en òrbita. Un cop analitzats tots els efectes que el microprocessador ha de suportar durant una missió, s’estudien els passos per a poder obtenir la qualificació espacial mitjançant els TRL, és a dir, quins TRA s’han de realitzar. A més a més, s’estudia també en quines fases perillarà més el seu rendiment i, finalment, es decideixen els tests corresponents per confirmar el seu funcionament durant la missió. Els tests escollits són: una prova de buit tèrmic i l’estudi de la radiació espacial simulant els cinturons de Van Allen, mitjançant els software FLUKA i SPENVIS. Per poder entendre el comportament del microprocessador en els tests, abans dels experiments i simulacions, es detalla teòricament els dos medi ambients escollits. Finalment, un cop realitzats els test, es confirmen els TRL que el microprocessador ha superat. Així doncs, el TRL 1 i TRL 2 queden superats, ja que durant el treball es realitza una primera idea de la missió i s’analitzen les possibles aplicacions. El TRL 3 també s’assoleix, ja que supera tots els test i simulacions proposats. No obstant, el TRL 4, degut a que incorpora integració amb altres components del femtosatèl·lit, queda fora del nostre abast

Validation activities of a microprocessor for space applications

Launching a satellite is a high cost mission. However, nowadays, low-mass and low-cost satellites are being developed to reduce mission costs, above all the scientific and educative ones. This thesis focuses on the study of one of the components of a femtosatellite designed and build at EETAC university. The component to be analyzed is the microprocessor. In order to meet the low cost requirements, those satellites must be built with COTS technology. The positive point of that technology is that it is affordable to anyone, in terms of economical aspects and readily availability. Nevertheless, it is not optimum to operate in the space environment, since it is not qualified and thus, its survivability is unknown. Once the existent problem of the COTS technology has been presented, the goal of this thesis is to achieve a certain space qualification level. The microprocessor Atmega 168 will be the analyzed COTS component. Future missions and potential applications are firstly analyzed in order to space- qualify the microprocessor. After that, the issues regarding to all the mission phases (pre-launch, launch, and orbit operations) are studied. This will help us to determine what are the harmful effects on the microprocessor. When all the effects that the microprocessor must deal with have been analyzed, the steps to obtain a certain space qualification are addressed. The basic procedures are defined by the corresponding TRA for each TRL. From TRA documentation, the proper tests and simulations are chosen within a realistic environment. The tests are a thermal vacuum laboratory experiment and a radiation exposure analysis, simulating the Van Allen belts, using the commercial software packages FLUKA and SPENVIS. Theoretical background to support the experiments and simulations are previously provided. Finally, after testing the microprocessor, the TRL level reached by it can be determined. Therefore, TRL 1 and TRL 2 are clearly achieved, since potential applications of the physical concept are developed. Given all that, we can conclude that the microprocessor has achieved TRL level 3. It passed all the tests and simulations conducted in this thesis. Nonetheless, TRL 4 is not achievable because Integration between satellite components must be tested. The integration of components is out of the scope of this thesis.Català: Enviar un satèl·lit a l’espai és una missió d’alt cost. No obstant, actualment, s’estan construint satèl·lits de massa i mida molt més reduïda per abaratir els costos d’algunes missions espacials, sobretot, les que tenen caire científic i educatiu. Aquesta tesis es focalitza en l’estudi d’un dels components del femtosatèl·lit creat per l’EETAC, el microprocessador. Per poder dur a terme el requeriment de baix cost, aquets satèl·lits usen tecnologia COTS. Els punts positius d’aquesta tecnologia es que és més econòmica que la usada en satèl·lits comercials i és a l’abast de tothom. Per altra banda, els seu punt negatius es que no és una tecnologia òptima per operar en espai, ja que no està qualificada i per tant no sabem la seva fiabilitat en aquest ambient. Un cop presentat el problema existent amb la tecnologia COTS, l’objectiu d’aquesta tesis és assolir un cert nivell de qualificació espacial. La tecnologia COTS que està sotmesa a anàlisis és el microprocessador ATmega 168. Per poder qualificar el microprocessador, primerament s’analitzen les seves possibles aplicacions i futures missions. Després, es realitza un anàlisis de tota la problemàtica que comporten les diferents fases que experimenta el microprocessador: pre-llançament, llançament i operació en òrbita. Un cop analitzats tots els efectes que el microprocessador ha de suportar durant una missió, s’estudien els passos per a poder obtenir la qualificació espacial mitjançant els TRL, és a dir, quins TRA s’han de realitzar. A més a més, s’estudia també en quines fases perillarà més el seu rendiment i, finalment, es decideixen els tests corresponents per confirmar el seu funcionament durant la missió. Els tests escollits són: una prova de buit tèrmic i l’estudi de la radiació espacial simulant els cinturons de Van Allen, mitjançant els software FLUKA i SPENVIS. Per poder entendre el comportament del microprocessador en els tests, abans dels experiments i simulacions, es detalla teòricament els dos medi ambients escollits. Finalment, un cop realitzats els test, es confirmen els TRL que el microprocessador ha superat. Així doncs, el TRL 1 i TRL 2 queden superats, ja que durant el treball es realitza una primera idea de la missió i s’analitzen les possibles aplicacions. El TRL 3 també s’assoleix, ja que supera tots els test i simulacions proposats. No obstant, el TRL 4, degut a que incorpora integració amb altres components del femtosatèl·lit, queda fora del nostre abast

Diversity and ethics in trauma and acute care surgery teams: results from an international survey

Background Investigating the context of trauma and acute care surgery, the article aims at understanding the factors that can enhance some ethical aspects, namely the importance of patient consent, the perceptiveness of the ethical role of the trauma leader, and the perceived importance of ethics as an educational subject. Methods The article employs an international questionnaire promoted by the World Society of Emergency Surgery. Results Through the analysis of 402 fully filled questionnaires by surgeons from 72 different countries, the three main ethical topics are investigated through the lens of gender, membership of an academic or non-academic institution, an official trauma team, and a diverse group. In general terms, results highlight greater attention paid by surgeons belonging to academic institutions, official trauma teams, and diverse groups. Conclusions Our results underline that some organizational factors (e.g., the fact that the team belongs to a university context or is more diverse) might lead to the development of a higher sensibility on ethical matters. Embracing cultural diversity forces trauma teams to deal with different mindsets. Organizations should, therefore, consider those elements in defining their organizational procedures. Level of evidence Trauma and acute care teams work under tremendous pressure and complex circumstances, with their members needing to make ethical decisions quickly. The international survey allowed to shed light on how team assembly decisions might represent an opportunity to coordinate team member actions and increase performance

miR-542: a novel regulator for muscle mass and function

Loss of skeletal muscle mass and function is a common co-morbidity of a number of chronic diseases including chronic obstructive pulmonary disease (COPD) and a range of critical illnesses as well as in ageing, affecting the quality of life of these individuals. However, the mechanisms by which this occurs have not been completely elucidated. Previous studies in the group identified changed in the levels of several microRNAs in the quadriceps of COPD patients. We focused on the microRNAs that showed the largest and most significant increased expression between patients and controls. One of the elevated microRNAs was miR-542-3p, which was chosen after performing a bioinformatics analysis and saw interesting predicted targets in the muscle wasting context. MiR-542-3p was also found to be elevated in the quadriceps muscle of sarcopenic patients. In this thesis, we aimed to determine if miR-542-5p was also elevated in those two cohorts and if a similar pattern for miR-542-3p/-5p was seen in critical illness such as patients with intensive care unit acquired weakness (ICUAW). We also aimed to identify the molecular pathways by which these miRNAs contributed to muscle impairment or dysfunction. miR-542-3p/5p levels were found elevated in COPD and sarcopenic patients but more markedly elevated in patients with ICUAW. In vitro, miR-542-3p decreased the expression of mitochondrial (MRPS10) and cytoplasmic (RPS23) ribosomal proteins and reduced 12S and 18S ribosomal RNA (rRNA) suggesting mitochondrial and cytoplasmic ribosomal stress. miR-542-3p/-5p promoted the nuclear accumulation of phospho SMAD2/3 and suppressed expression of SMURF1, SMAD7 and PPP2CA which are inhibitors of the system, indicative of increased TGF-β signalling. In vivo, miR-542 over expression caused muscle wasting in the targeted muscle, decreased mitochondrial function, 12S rRNA and 18S rRNA levels and SMAD7 expression, consistent with the effects of the miRNA in vitro. In patients with ICUAW similar results were observed, the expression of 12S and 18S rRNA and SMURF1, SMAD7 and PPP2CA were reduced, suggesting mitochondrial and cytoplasmic ribosomal stress and increased TGF-β signalling.Open Acces

Validation activities of a microprocessor for space applications

Launching a satellite is a high cost mission. However, nowadays, low-mass and low-cost satellites are being developed to reduce mission costs, above all the scientific and educative ones. This thesis focuses on the study of one of the components of a femtosatellite designed and build at EETAC university. The component to be analyzed is the microprocessor. In order to meet the low cost requirements, those satellites must be built with COTS technology. The positive point of that technology is that it is affordable to anyone, in terms of economical aspects and readily availability. Nevertheless, it is not optimum to operate in the space environment, since it is not qualified and thus, its survivability is unknown. Once the existent problem of the COTS technology has been presented, the goal of this thesis is to achieve a certain space qualification level. The microprocessor Atmega 168 will be the analyzed COTS component. Future missions and potential applications are firstly analyzed in order to space- qualify the microprocessor. After that, the issues regarding to all the mission phases (pre-launch, launch, and orbit operations) are studied. This will help us to determine what are the harmful effects on the microprocessor. When all the effects that the microprocessor must deal with have been analyzed, the steps to obtain a certain space qualification are addressed. The basic procedures are defined by the corresponding TRA for each TRL. From TRA documentation, the proper tests and simulations are chosen within a realistic environment. The tests are a thermal vacuum laboratory experiment and a radiation exposure analysis, simulating the Van Allen belts, using the commercial software packages FLUKA and SPENVIS. Theoretical background to support the experiments and simulations are previously provided. Finally, after testing the microprocessor, the TRL level reached by it can be determined. Therefore, TRL 1 and TRL 2 are clearly achieved, since potential applications of the physical concept are developed. Given all that, we can conclude that the microprocessor has achieved TRL level 3. It passed all the tests and simulations conducted in this thesis. Nonetheless, TRL 4 is not achievable because Integration between satellite components must be tested. The integration of components is out of the scope of this thesis.Català: Enviar un satèl·lit a l’espai és una missió d’alt cost. No obstant, actualment, s’estan construint satèl·lits de massa i mida molt més reduïda per abaratir els costos d’algunes missions espacials, sobretot, les que tenen caire científic i educatiu. Aquesta tesis es focalitza en l’estudi d’un dels components del femtosatèl·lit creat per l’EETAC, el microprocessador. Per poder dur a terme el requeriment de baix cost, aquets satèl·lits usen tecnologia COTS. Els punts positius d’aquesta tecnologia es que és més econòmica que la usada en satèl·lits comercials i és a l’abast de tothom. Per altra banda, els seu punt negatius es que no és una tecnologia òptima per operar en espai, ja que no està qualificada i per tant no sabem la seva fiabilitat en aquest ambient. Un cop presentat el problema existent amb la tecnologia COTS, l’objectiu d’aquesta tesis és assolir un cert nivell de qualificació espacial. La tecnologia COTS que està sotmesa a anàlisis és el microprocessador ATmega 168. Per poder qualificar el microprocessador, primerament s’analitzen les seves possibles aplicacions i futures missions. Després, es realitza un anàlisis de tota la problemàtica que comporten les diferents fases que experimenta el microprocessador: pre-llançament, llançament i operació en òrbita. Un cop analitzats tots els efectes que el microprocessador ha de suportar durant una missió, s’estudien els passos per a poder obtenir la qualificació espacial mitjançant els TRL, és a dir, quins TRA s’han de realitzar. A més a més, s’estudia també en quines fases perillarà més el seu rendiment i, finalment, es decideixen els tests corresponents per confirmar el seu funcionament durant la missió. Els tests escollits són: una prova de buit tèrmic i l’estudi de la radiació espacial simulant els cinturons de Van Allen, mitjançant els software FLUKA i SPENVIS. Per poder entendre el comportament del microprocessador en els tests, abans dels experiments i simulacions, es detalla teòricament els dos medi ambients escollits. Finalment, un cop realitzats els test, es confirmen els TRL que el microprocessador ha superat. Així doncs, el TRL 1 i TRL 2 queden superats, ja que durant el treball es realitza una primera idea de la missió i s’analitzen les possibles aplicacions. El TRL 3 també s’assoleix, ja que supera tots els test i simulacions proposats. No obstant, el TRL 4, degut a que incorpora integració amb altres components del femtosatèl·lit, queda fora del nostre abast

Enhanced Recovery After Surgery (ERAS) - The Evidence in Geriatric Emergency Surgery: A Systematic Review

Background: Geriatric surgery is rising and projected to continue at a greater rate. There is already concern about the poor outcomes for the emergency surgery in elderly. How to manage the available resources to improve outcomes in this group of patients is an important object of debate.Objectives: We aimed to determine the feasibility and safety of applying ERAS pathways to emergency elderly surgical patients.Method: Two searches were undertaken for ERAS protocols in elderly patients and emergency surgery, in order to gather evidence in relation to ERAS in geriatric emergency patients. Primary outcomes were postoperative complications, mortality, hospital length of stay and readmission rates.Results. Eighteen studies were included. The majority of patients were older than 70. Elderly patients had fewer postoperative complications and a reduced hospitalization with ERAS compared to conventional care. Emergency surgical patients also had fewer postoperative complications with ERAS compared to conventional care. Hospital stay was reduced in 2 out of 3 studies for emergency surgery.Conclusions: ERAS can be safely applied to elderly and emergency patients with a reduction in postoperative complications, hospitalization and readmission rates. There is evidence to suggest that ERAS is feasible and beneficial for geriatric emergency patients

Impact of the SARS-CoV-2 (COVID19) pandemic on the morbidity and mortality of high risk patients undergoing surgery: a non-inferiority retrospective observational study

Background: During the COVID-19 crisis it was necessary to generate a specific care network and reconvert operating rooms to attend emergency and high-acuity patients undergoing complex surgery. The aim of this study is to classify postoperative complications and mortality and to assess the impact that the COVID-19 pandemic may have had on the results. Methods: this is a non-inferiority retrospective observational study. Two different groups of surgical patients were created: Pre-pandemic COVID and Pandemic COVID. Severity of illness was rated according to the Diagnosis-related Groups (DRG) score. Comparisons were made between groups and between DRG severity score-matched samples. Non-inferiority was set at up to 10 % difference for grade III to V complications according to the Clavien-Dindo classification, and up to 2 % difference in mortality. Results: A total of 1649 patients in the PreCOVID group and 763 patients in the COVID group were analysed; 371 patients were matched for DRG severity score 3-4 (236 preCOVID and 135 COVID). No differences were found in relation to re-operation (22.5 % vs. 21.5 %) or late admission to critical care unit (5.1 % vs. 4.5 %). Clavien grade III to V complications occurred in 107 patients (45.3 %) in the PreCOVID group and in 56 patients (41.5 %) in the COVID group, and mortality was 12.7 % and 12.6 %, respectively. During the pandemic, 3 % of patients tested positive for Covid-19 on PCR: 12 patients undergoing elective surgery and 11 emergency surgery; there were 5 deaths, 3 of which were due to respiratory failure following Covid-19-induced pneumonia. Conclusions: Although this study has some limitations, it has shown the non-inferiority of surgical outcomes during the COVID pandemic, and indicates that resuming elective surgery is safe

miR‐424‐5p reduces ribosomal RNA and protein synthesis in muscle wasting

Abstract Background A loss of muscle mass occurs as a consequence of a range of chronic and acute diseases as well as in older age. This wasting results from an imbalance of protein synthesis and degradation with a reduction in synthesis and resistance to anabolic stimulation often reported features. Ribosomes are required for protein synthesis, so changes in the control of ribosome synthesis are potential contributors to muscle wasting. MicroRNAs (miRNAs) are known regulators of muscle phenotype and have been shown to modulate components of the protein synthetic pathway. One miRNA that is predicted to target a number of components of protein synthetic pathway is miR‐424‐5p, which is elevated in the quadriceps of patients with chronic obstructive pulmonary disease (COPD). Methods Targets of miR‐424‐5p were identified by Argonaute2 pull down, and the effects of the miRNA on RNA and protein expression were determined by quantitative polymerase chain reaction and western blotting in muscle cells in vitro. Protein synthesis was determined by puromycin incorporation in vitro. The miRNA was over‐expressed in the tibialis anterior muscle of mice by electroporation and the effects quantified. Finally, quadriceps expression of the miRNA was determined by quantitative polymerase chain reaction in patients with COPD and intensive care unit (ICU)‐acquired weakness and in patients undergoing aortic surgery as well as in individuals from the Hertfordshire Sarcopenia Study. Results Pull‐down assays showed that miR‐424‐5p bound to messenger RNAs encoding proteins associated with muscle protein synthesis. The most highly enriched messenger RNAs encoded proteins required for the Pol I RNA pre‐initiation complex required for ribosomal RNA (rRNA) transcription, (PolR1A and upstream binding transcription factor). In vitro, miR‐424‐5p reduced the expression of these RNAs, reduced rRNA levels, and inhibited protein synthesis. In mice, over‐expression of miR‐322 (rodent miR‐424 orthologue) caused fibre atrophy and reduced upstream binding transcription factor expression and rRNA levels. In humans, elevated miR‐424‐5p associated with markers of disease severity in COPD (FEV1%), in patients undergoing aortic surgery (LVEF%), and in patients with ICU‐acquired weakness (days in ICU). In patients undergoing aortic surgery, preoperative miR‐424‐5p expression in skeletal muscle was associated with muscle loss over the following 7 days. Conclusions These data suggest that miR‐424‐5p regulates rRNA synthesis by inhibiting Pol I pre‐initiation complex formation. Increased miR‐424‐5p expression in patients with conditions associated with muscle wasting is likely to contribute to the inhibition of protein synthesis and loss of muscle mass

A de novo nonsense mutation in MAGEL2 in a patient initially diagnosed as Opitz-C: similarities between Schaaf-Yang and Opitz-C syndromes

Opitz trigonocephaly C syndrome (OTCS) is a rare genetic disorder characterized by craniofacial anomalies, variable intellectual and psychomotor disability, and variable cardiac defects with a high mortality rate. Different patterns of inheritance and genetic heterogeneity are known in this syndrome. Whole exome and genome sequencing of a 19-year-old girl (P7), initially diagnosed with OTCS, revealed a de novo nonsense mutation, p.Q638*, in the MAGEL2 gene. MAGEL2 is an imprinted, maternally silenced, gene located at 15q11-13, within the Prader-Willi region. Patient P7 carried the mutation in the paternal chromosome. Recently, mutations in MAGEL2 have been described in Schaaf-Yang syndrome (SHFYNG) and in severe arthrogryposis. Patient P7 bears resemblances with SHFYNG cases but has other findings not described in this syndrome and common in OTCS. We sequenced MAGEL2 in nine additional OTCS patients and no mutations were found. This study provides the first clear molecular genetic basis for an OTCS case, indicates that there is overlap between OTCS and SHFYNG syndromes, and confirms that OTCS is genetically heterogeneous. Genes encoding MAGEL2 partners, either in the retrograde transport or in the ubiquitination-deubiquitination complexes, are promising candidates as OTCS disease-causing genes.Funding was from Associació Síndrome Opitz C, Terrassa, Spain; Spanish Ministerio de Economía y Competitividad (SAF2014-56562-R; FECYT, crowdfunding PRECIPITA); Catalan Government (2014SGR932) and from CIBERER (U720). We acknowledge support of the Spanish Ministry of Economy and Competitiveness, 'Centro de Excelencia Severo Ochoa 2013-2017'