Lessons Learned from Building the First Chilean Nano-satellite: The SUCHAI Project

This work presents the preliminary results and the lessons learned from the operation, thus far, of the Satellite of the University of Chile for Aerospace Investigation (SUCHAI-1), the first CubeSat mission at the University of Chile. The development of the SUCHAI-1 started in 2011 and was launched in June 23rd 2017 in an Indian PSLV Rocket. The launch resulted in a circular polar sun-synchronous orbit at an altitude close to 505 km. The SUCHAI-1 has operated continuously for more than 12 months except for three days after the mid-September 2017 solar storm. The SUCHAI-1 has been studying the capabilities that CubeSats can offer for scientific missions and collecting data from on-board payloads. This project has been the seed for a much longer space program at the University. Currently two other CubeSats are under construction. In this work, we describe the difficulties and the advantages of developing a nano-satellite project in a developing country and the impact that this project has had in students as well as in the space area in Chile

Effects of splitter Blade Length on disc pump performance

The disc pump operates using boundary layer principle and viscous drag with a relatively low efficiency. There are methods to increase head and efficiency, one of them is the placing of blades sectors or splitter blades in discs. This method has been applied only in the low viscosity fluids pumping (v < 0.1 stokes). This study describe an experimental research in a hight viscocity fluid (v = 2 stokes) with exit angle (32 = 35° and different splitter blades Lengths (Ls) (75, 50, 25%). The purpose is to determinate the splitter blades length that achieves the most effective combination between the blade effect and boundary layer effect in order to increase the energy transmission efficiency from the impeller to the fluid. As result, it can be established that the use of spliter blades is an alternative to increase the performance of the disc pump. The highest efficiency and head were obtained for the gapsize between two discs (b) of 12 mm using a 50% spliter blades length of the main blade length

The First Chilean Satellite Swarm: Approach and Lessons Learned

SUCHAI 2, SUCHAI 3, and Plansat are three 3U CubeSats designed, manufactured, integrated, and tested by the Space and Planetary Exploration Laboratory at the University of Chile (SPEL). They were launched into space on April 1, 2022, aboard a D-Orbit ION platform. The ION deployer was carried into space on the SpaceX Falcon 9 Transporter 4 mission. The nanosatellites included payloads and experiments from several other national and international groups, all featuring different missions and configurations. We developed the three CubeSats simultaneously. Some subsystems are the same, while others are specific to each satellite. They include scientific and technical payloads. The technical payloads, such as an in-house developed star tracker and reaction wheels, were shared by all three satellites. The research missions differed: SUCHAI 2 has an optical payload, SUCHAI 3 has some communication payloads, and Plantsat has biological payloads, as well as other experiments with graphene-based devices. In addition, we implemented other secondary scientific payloads on more than one satellite. The responsible institutions were not the same for each payload (SPEL, other groups from the University of Chile, other national universities or research institutions, and international groups from other universities). Moreover, SPEL performed environmental tests in the university facilities. We conceived a lean project management approach to coordinate all the stakeholders under a schedule and human resource constraints. In this approach, we separated every satellite architecture into subsystems and classified every subsystem according to its current development status in different phases. Every subsystem required a physical interphase and defined physical space in the satellite. In addition, we ported the SUCHAI satellite software into all the subsystems, including payloads, the onboard computer, and the ground station. The findings for the different subsystems developed by multiple groups and the legacy from former projects allow us developing more complex and robust flying payloads. Furthermore, the design of an integrated light test procedure for each subsystem enabled us to detect integraiton errors and check the satellite\u27s health at various stages of the integration process. After the launch, the operation of the satellites also implied new challenges and findings to consider in the design of the daily operation plan. These changed the original flight plan designed during the subsystem development and integration. However, the legacy from the various subsystems and the functionality tests used during the integration and testing stages enabled us to overcome these challenges. This article summarizes the complete development cycle: we describe every mission concept, the design strategy to coordinate different missions and teams in the development process, the construction strategy, integration and testing philosophies, and the data processing, handling, and distribution schemes. Finally, we present some preliminary results and enumerate the main challenges and lessons learned from this project

Cost-Effectiveness of Therapeutic Drug Monitoring of Anti-TNF Therapy in Inflammatory Bowel Disease: A Systematic Review

Infliximab and adalimumab are monoclonal antibodies against tumor necrosis factor (anti-TNF) used to manage inflammatory bowel disease (IBD). Therapeutic Drug Monitoring (TDM) has been proven to prevent immunogenicity, to achieve better long-term clinical results and to save costs in IBD treatment. The aim of this study was to conduct a systematic review on cost-effectiveness analyses of studies that apply TDM of anti-TNF in IBD and to provide a critical analysis of the best scientific knowledge available in the literature. The quality of the included studies was assessed using Consolidated Health Economic Evaluation Reporting Standards (CHEERS). Cost-effectiveness of the TDM strategies was presented as total costs, cost savings, quality-adjusted life-years (QALY) and incremental cost-effectiveness ratio (ICER). Thirteen studies that examined the health economics of TDM of anti-TNF in IBD from 2013 to 2021 were included. Eight of them (61.5%) achieved a score between 17 and 23 on the CHEERS checklist. The comparison between the TDM strategy and an empirical strategy was cost saving. The ICER between reactive TDM and an empirical strategy was dominated (favorable) by reactive TDM, whereas the ICER value for proactive TDM compared to an empirical strategy ranged from EUR 56,845 to 3,901,554. This systematic review demonstrated that a TDM strategy is cost-effective or cost-saving in IBD.S.M.-M. received a predoctoral fellowship from Miguel Hernandez University (“Ayudas a la contratación de personal investigador en formación 2021”).S

Mapping of neurokinin-like immunoreactivity in the human brainstem

BACKGROUND: Using an indirect immunoperoxidase technique, we have studied the distribution of immunoreactive fibers and cell bodies containing neurokinin in the adult human brainstem with no prior history of neurological or psychiatric disease. RESULTS: Clusters of immunoreactive cell bodies and high densities of neurokinin-immunoreactive fibers were located in the periaqueductal gray, the dorsal motor nucleus of the vagus and in the reticular formation of the medulla, pons and mesencephalon. Moreover, immunoreactive cell bodies were found in the inferior colliculus, the raphe obscurus, the nucleus prepositus hypoglossi, and in the midline of the anterior medulla oblongata. In general, immunoreactive fibers containing neurokinin were observed throughout the whole brainstem. In addition to the nuclei mentioned above, the highest densities of such immunoreactive fibers were located in the spinal trigeminal nucleus, the lateral reticular nucleus, the nucleus of the solitary tract, the superior colliculus, the substantia nigra, the nucleus ambiguus, the gracile nucleus, the cuneate nucleus, the motor hypoglossal nucleus, the medial and superior vestibular nuclei, the nucleus prepositus hypoglossi and the interpeduncular nucleus. CONCLUSION: The widespread distribution of immunoreactive structures containing neurokinin in the human brainstem indicates that neurokinin might be involved in several physiological mechanisms, acting as a neurotransmitter and/or neuromodulator

Heterogeneous vancomycin-intermediate susceptibility in a community-associated methicillin-resistant Staphylococcus aureus epidemic clone, in a case of Infective Endocarditis in Argentina

BACKGROUND: Community-Associated Methicillin Resistant Staphylococcus aureus (CA-MRSA) has traditionally been related to skin and soft tissue infections in healthy young patients. However, it has now emerged as responsible for severe infections worldwide, for which vancomycin is one of the mainstays of treatment. Infective endocarditis (IE) due to CA-MRSA with heterogeneous vancomycin-intermediate susceptibility-(h-VISA) has been recently reported, associated to an epidemic USA 300 CA-MRSA clone. CASE PRESENTATION: We describe the occurrence of h-VISA phenotype in a case of IE caused by a strain belonging to an epidemic CA-MRSA clone, distinct from USA300, for the first time in Argentina. The isolate h-VISA (SaB2) was recovered from a patient with persistent bacteraemia after a 7-day therapy with vancomycin, which evolved to fatal case of IE complicated with brain abscesses. The initial isolate-(SaB1) was fully vancomycin susceptible (VSSA). Although MRSA SaB2 was vancomycin susceptible (≤ 2 μg/ml) by MIC (agar and broth dilution, E-test and VITEK 2), a slight increase of MIC values between SaB1 and SaB2 isolates was detected by the four MIC methods, particularly for teicoplanin. Moreover, Sab2 was classified as h-VISA by three different screening methods [MHA5T-screening agar, Macromethod-E-test-(MET) and by GRD E-test] and confirmed by population analysis profile-(PAP). In addition, a significant increase in cell-wall thickness was revealed for SaB2 by electron microscopy. Molecular typing showed that both strains, SaB1 and SaB2, belonged to ST5 lineage, carried SCCmecIV, lacked Panton-Valentine leukocidin-(PVL) genes and had indistinguishable PFGE patterns (subtype I2), thereby confirming their isogenic nature. In addition, they were clonally related to the epidemic CA-MRSA clone (pulsotype I) detected in our country. CONCLUSIONS: This report demonstrates the ability of this epidemic CA-MRSA clone, disseminated in some regions of Argentina, to produce severe and rapidly fatal infections such as IE, in addition to its ability to acquire low-level vancomycin resistance; for these reasons, it constitutes a new challenge for the Healthcare System of this country.This study was supported by the National Council for Scientific Research and Technology of Argentina (CONICET), Agencia Nacional de Promoción Científica y Tecnológica (ANPCyT - PICT 01630 to JLB), Secretaría de Ciencia y Técnica-Universidad Nacional de Córdoba (SECyT-UNC) and Agencia Córdoba Ciencia.S

The body mass index increases the genetic risk scores' ability to predict risk of hepatic damage in European adolescents: The HELENA study

Background Hepatic disorders are often complex and multifactorial, modulated by genetic and environmental determinants. During the last years, the hepatic disease has been progressively established from early stages in life. The use of genetic risk scores (GRS) to predict the genetic susceptibility to a particular phenotype among youth has gained interest in recent years. Moreover, the alanine aminotransferase (ALT) blood biomarker is often considered as hepatic screening tool, in combination with imaging techniques. The aim of the present study was to develop an ALT-specific GRS to help in the evaluation of hepatic damage risk in European adolescents. Methods A total of 972 adolescents (51.3% females), aged 12.5–17.5 years, from the Healthy Lifestyle in Europe by Nutrition in Adolescence study were included in the analyses. The sample incorporated adolescents in all body mass index (BMI) categories and was divided considering healthy/unhealthy ALT levels, using sex-specific cut-off points. From 1212 a priori ALT-related single nucleotide polymorphisms (SNPs) extracted from candidate gene selection, a first screening of 234 SNPs univariately associated was established, selecting seven significant SNPs (p < .05) in the multivariate model. An unweighted GRS (uGRS) was developed by summing the number of reference alleles, and a weighted GRS (wGRS), by multiplying each allele to its estimated coefficient. Results The uGRS and wGRS were significantly associated with ALT (p < .001). The area under curve was obtained integrating BMI as clinical factor, improving the predictive ability for uGRS (.7039) and wGRS (.7035), using 10-fold internal cross-validation. Conclusions Considering BMI status, both GRSs could contribute as complementary tools to help in the early diagnosis of hepatic damage risk in European adolescents

Mapping of Genetic Abnormalities of Primary Tumours from Metastatic CRC by High-Resolution SNP Arrays

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: For years, the genetics of metastatic colorectal cancer (CRC) have been studied using a variety of techniques. However, most of the approaches employed so far have a relatively limited resolution which hampers detailed characterization of the common recurrent chromosomal breakpoints as well as the identification of small regions carrying genetic changes and the genes involved in them. [Methodology/Principal Findings]: Here we applied 500K SNP arrays to map the most common chromosomal lesions present at diagnosis in a series of 23 primary tumours from sporadic CRC patients who had developed liver metastasis. Overall our results confirm that the genetic profile of metastatic CRC is defined by imbalanced gains of chromosomes 7, 8q, 11q, 13q, 20q and X together with losses of the 1p, 8p, 17p and 18q chromosome regions. In addition, SNP-array studies allowed the identification of small (1.5 Mb) altered DNA sequences, many of which contain cancer genes known to be involved in CRC and the metastatic process. Detailed characterization of the breakpoint regions for the altered chromosomes showed four recurrent breakpoints at chromosomes 1p12, 8p12, 17p11.2 and 20p12.1; interestingly, the most frequently observed recurrent chromosomal breakpoint was localized at 17p11.2 and systematically targeted the FAM27L gene, whose role in CRC deserves further investigations. [Conclusions/Significance]: In summary, in the present study we provide a detailed map of the genetic abnormalities of primary tumours from metastatic CRC patients, which confirm and extend on previous observations as regards the identification of genes potentially involved in development of CRC and the metastatic process.This work has been partially supported by grants from the Consejeria de Sanidad, Junta de Castilla y Leon, Valladolid, Spain (SAN191/SA09/06 and SAN673/SA39/08), Fundacion Memoria de Don Samuel Solorzano Barruso, Salamanca, Spain, Caja de Burgos (Obra Social), Burgos, Spain, Grupo Excelencia de Castilla y Leon (GR37) and the RTICC from the Instituto de Salud Carlos III (ISCIII), Ministerio de Ciencia e Innovacion, Madrid, Spain (RD06/0020/0035-FEDER). JM Sayagués, M Gonzalez, ME Sarasquete and MC Chillon are supported by grants (CP05/00321, FI08/00721, CA08/00212 and CA/07/00077, respectively) from the ISCIII, Ministerio de Ciencia e Innovación, Madrid, Spain. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewe

Long-Term Dabigatran Treatment Delays Alzheimer's Disease Pathogenesis in the TgCRND8 Mouse Model

BACKGROUND: Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder with important vascular and hemostatic alterations that should be taken into account during diagnosis and treatment. OBJECTIVES: This study evaluates whether anticoagulation with dabigatran, a clinically approved oral direct thrombin inhibitor with a low risk of intracerebral hemorrhage, ameliorates AD pathogenesis in a transgenic mouse model of AD. METHODS: TgCRND8 AD mice and their wild-type littermates were treated for 1 year with dabigatran etexilate or placebo. Cognition was evaluated using the Barnes maze, and cerebral perfusion was examined by arterial spin labeling. At the molecular level, Western blot and histochemical analyses were performed to analyze fibrin content, amyloid burden, neuroinflammatory activity, and blood-brain barrier (BBB) integrity. RESULTS: Anticoagulation with dabigatran prevented memory decline, cerebral hypoperfusion, and toxic fibrin deposition in the AD mouse brain. In addition, long-term dabigatran treatment significantly reduced the extent of amyloid plaques, oligomers, phagocytic microglia, and infiltrated T cells by 23.7%, 51.8%, 31.3%, and 32.2%, respectively. Dabigatran anticoagulation also prevented AD-related astrogliosis and pericyte alterations, and maintained expression of the water channel aquaporin-4 at astrocytic perivascular endfeet of the BBB. CONCLUSIONS: Long-term anticoagulation with dabigatran inhibited thrombin and the formation of occlusive thrombi in AD; preserved cognition, cerebral perfusion, and BBB function; and ameliorated neuroinflammation and amyloid deposition in AD mice. Our results open a field for future investigation on whether the use of direct oral anticoagulants might be of therapeutic value in AD.This work was funded by a Proof-of-Concept Award from the Robertson Therapeutic Development Fund (Dr. Cortes-Canteli), The Rockefeller University; NINDS/NIH grant NIS106668 (Drs. Norris and Strickland); European Union’s Seventh Framework Programme (FP7-PEOPLE-2013-IIF), grant agreement n PIIF-GA-2013-624811 (Drs. Cortes-Canteli and Fuster), CNIC, Madrid, Spain; Miguel Servet type I research contract (CP16/00174 and MS16/00174 [Dr. Cortes-Canteli]), Instituto de Salud Carlos III (ISCIII), CNIC; Iniciativa de Empleo Juvenil (PEJ16/MED/TL-1231 [A. Marcos-Diaz] and PEJ-2018-AI/BMD-11477 [C. Ceron]) from Consejería de Educación, Juventud y Deporte de la Comunidad de Madrid; European Regional Development Funds (FEDER “Una manera de hacer Europa”) and European Social Funds (FSE “El FSE invierte en tu futuro”); and with the support of the Marie Curie Alumni Association (Dr. Cortes-Canteli). The CNIC is supported by the ISCIII, the Spanish Ministerio de Ciencia, Innovación y Universidades (MCNU), and the Pro CNIC Foundation, and is a Severo Ochoa Center of Excellence (SEV-2015-0505). CIC biomaGUNE is a Maria de Maeztu Unit of Excellence (MDM-2017-0720). Dr. Sanchez-Gonzalez is an employee of Philips Healthcare. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose.S