Graphene loop heat pipe in space

We report a graphene enhanced capillary pump for a Loop Heat Pipe (LHP). LHPs are passive devices for thermal control of equipment and payloads for satellites and probes. Capable to transfer heat from sources to the satellite radiators, LHPs use the waste heat of the devices to be cooled as the driving energy for pumping a fluid through a loop. The core of a LHP is a capillary pump, a phase separator that allows pressure being generated by capillarity across a porous structure, in two-phase conditions for the operating fluid. Traditionally, LHPs capillary pumps are sintered metallic wicks. Various properties of graphene have been considered for enhancing the LHP performance, acting at capillary pump level: porosity, wettability and thermal conductivity. Major issues in using conventional LHPs, i.e. with metallic wicks, in operational space missions are related to their non-deterministic start-up behaviour. Additionally, reliable LHPs are required to ensure operations without interruption for the entire mission duration. Superior start-up capabilities have been achieved with graphene oxide coated Ni sintered wicks, using acetone as a fluid, operated in a vacuum chamber on ground. A LHP capillary pump was tested during a zero-g parabolic flights campaign, to eliminate gravity effects. The measurements show up to 8 times improvement in evaporation rate compared a conventional metal only wick.SCOPUS: cp.pinfo:eu-repo/semantics/publishe

Outcomes for patients with COVID-19 admitted to Australian intensive care units during the first four months of the pandemic

Objectives: To describe the characteristics and outcomes of patients with COVID-19 admitted to intensive care units (ICUs) during the initial months of the pandemic in Australia. Design, setting: Prospective, observational cohort study in 77 ICUs across

Compound a, a dissociated glucocorticoid receptor modulator, inhibits t-bet (th1) and induces gata-3 (th2) activity in immune cells

Background: Compound A (CpdA) is a dissociating non-steroidal glucocorticoid receptor (GR) ligand which has anti-inflammatory properties exerted by down-modulating proinflammatory gene expression. By favouring GR monomer formation, CpdA does not enhance glucocorticoid (GC) response element-driven gene expression, resulting in a reduced side effect profile as compared to GCs. Considering the importance of Th1/Th2 balance in the final outcome of immune and inflammatory responses, we analyzed how selective GR modulation differentially regulates the activity of T-bet and GATA-3, master drivers of Th1 and Th2 differentiation, respectively. Results: Using Western analysis and reporter gene assays, we show in murine T cells that, similar to GCs, CpdA inhibits T-bet activity via a transrepressive mechanism. Different from GCs, CpdA induces GATA-3 activity by p38 MAPK-induction of GATA-3 phosphorylation and nuclear translocation. CpdA effects are reversed by the GR antagonist RU38486, proving the involvement of GR in these actions. ELISA assays demonstrate that modulation of T-bet and GATA-3 impacts on cytokine production shown by a decrease in IFN-γ and an increase in IL-5 production, respectively. Conclusions: Taken together, through their effect favoring Th2 over Th1 responses, particular dissociated GR ligands, for which CpdA represents a paradigm, hold potential for the application in Th1-mediated immune disorders. © 2012 Liberman et al.Fil:Liberman, A.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Castro, C.N. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina.Fil:Druker, J. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina

Left Ventricular Diastolic Function in Healthy Adult Individuals: Results of the World Alliance Societies of Echocardiography Normal Values Study

Background: The World Alliance Societies of Echocardiography (WASE) study was conducted to describe echocardiographic normal values in adults and to compare races and nationalities using a uniform acquisition and measurement protocol. This report focuses on left ventricular (LV) diastolic function. Methods: WASE is an international, cross-sectional study. Participants were enrolled with equal distribution according to age and gender. Echocardiograms were analyzed in a core laboratory based on the latest American Society of Echocardiography/European Association of Cardiovascular Imaging guidelines. Left ventricular diastolic function was assessed by E, E/A, e' velocities, E/e', left atrial volume index (LAVI), and tricuspid regurgitation velocity. Determination of LV diastolic function was made using the algorithm proposed by the guidelines. Results: A total of 2,008 subjects from 15 countries were enrolled. The majority were of white or Asian race (42.8, 41.8, respectively). E and E/e' were higher in female patients, while LAVI was similar in both genders. Consistent increase in E/e' and decrease in E/A, E, and e' were found as age increased. The upper limit of normal for LAVI was higher in WASE compared with the guidelines. The lower limits of normal for e' were smaller in elder groups than those in the guidelines, while the upper limits of normal for E/e' were below the guideline values. These findings suggest that the cutoff value for LAVI should be shifted upward and age-specific cutoff values for e' should be considered. In WASE, <93.6 of patients were classified as normal LV diastolic function using the guidelines' algorithm, and the proportion increased to 97.4 when applying the revised cutoff values for LAVI obtained in our study. Conclusions: Guideline-recommended normal values for e' velocities and LAVI should be reconsidered. The algorithm for the determination of LV diastolic function proposed by the guidelines is useful, but adjustments to LAVI could further improve it. © 2020 American Society of Echocardiograph