Publications

Abstract BACKGROUND AND AIMS Renal recovery (RR) after AKI is a determinant outcome of future comorbidity and mortality in critical care patients. Related predictive factors remain uncertain. METHOD We retrospectively analyzed patients admitted to ICU between January 2020 and February 2021 from our critical nephrology database. We analyzed adult patients with diagnosis of AKI (KDIGO criteria) treated with renal replacement therapy (RRT) during ICU hospitalization. We excluded patients with dialysis support previous to the admission. The main outcomes we evaluated were (1) RR (successful suspension of RRT without hyperkalemia, increase in serum creatinine (SCr), hypervolemia or acidemia after 1 week without RRT, with urine volume > 500 mL/d without diuretic treatment or > 2000 mL/d with diuretics). (2) Mortality during hospitalization. RESULTS We found 1442 patients were admitted to ICU, 418 presented AKI (29.8%), of them, 178 patients (64% male) required RRT (AKI-RRTd) in ICU during follow-up, with mean age of 66 year old (52.8% >65 year). Main comorbidity and demographic data are in Table 1. Mean time in ICU was 19 days (RIC 11–35). The most frequent admission cause was non-surgical pathologies (93%), 53% of admitted patients had COVID-19 as main diagnosis (95 patients). There was need of vasoactive support in 73.6%, ventilatory support (82.6) and 67.2% of patients had fluid overload. The indication of dialysis was determined by a nephrologist: mainly oliguria, acidosis, hyperkalemia, fluid overload and increase SCr. Mean SCR at admission was 2.5 mg/dL. There were missing data in 48% of basal SCr (known SCr between 1 and 12 months prior to admission). Total mortality in AKI-RRTd was 70.8% (126 patients). In COVID patients, was 77.9% (74 patients). We found renal recovery in 63.4% of total survivors (33/52 patients). When analyzing COVID, there were 21 survivors, and we found renal recovery in 80.9% of patients. Patients who did not achieved renal recovery had longer ICU stay (median: 20 days, RIC: 4–26) and inhospitalization (median: 41 days, RIC: 29–58). Those patients were older, and had higher morbidity (diabetes), higher SCr at ICU admission and lower urine output. Their fluid balance was higher at 48 h after CRRT initiation (OR 3.05, 95% CI 1.39–6.65, P <.01). In COVID population without renal recovery, there were more urgent dialysis onset (OR 8.33, 95% confidence interval (95% CI) 1.04–66.2; P = .04), age > 65 year (OR 6.48, 95% CI 1.94–21.6; P < .01), positive fluid balance at 48 h after RRT (OR 3.25; 95% CI 1.09–9.69; P = .03). The risk factors for mortality, were age > 65 year (OR 4.14, 95% CI 2.05–8.35; P < .01), mechanical ventilation (OR 3.28, 95% CI 1.48–7.30; P < .01), haemodynamic support (OR 4.37, 95% CI 2.14–8.92; P < .01). Otherwise, lower SCr at admission (OR 0.82, 95% CI 0.71–0.93; P < .01) and at instauration of RRT (OR 0.75, 95% CI 0.065–0.88; P < .01) were associated to lower mortality. In COVID patients, fluid overload at RRT initiation (OR 10.83, 95% CI 1.37–85.36; P = .02), age > 65 year old (OR 8.85, 95% CI 2.68–29.1; P < .01) and FiO2 > 50% at RRT start (OR 2.77, 95% CI 1.02–7.50; P = .04) were associated to higher mortality. CONCLUSION In ICU patients with AKI-RRT dependence, negative fluid balance at 48 h after RRT onset and in COVID patients, age < 65 year old, negative fluid balance at 48 h after RRT onset and non-urgent onset of RRT were related with renal recovery.

Abstract While the outstanding properties of graphene have attracted a lot of attention, one of the major bottlenecks of its widespread usage is its availability in large volumes. Laser printing graphene on polyimide films is an efficient single‐step fabrication process that can remedy this issue. A laser‐printed, flexible pressure sensor is developed utilizing the piezoresistive effect of 3D porous graphene. The pressure sensors performance can be easily adjusted via the geometrical parameters. They have a sensitivity in the range of 1.23 × 10 −3 kPa and feature a high resolution with a detection limit of 10 Pa in combination with an extremely wide dynamic range of at least 20 MPa. They also provide excellent long‐term stability of at least 15 000 cycles. The biocompatibility of laser‐induced graphene is also evaluated by cytotoxicity assays and fluorescent staining, which show an insignificant drop in viability. Polymethyl methacrylate coating is particularly useful for underwater applications, protecting the sensors from biofouling and shunt currents, and enable operation at a depth of 2 km in highly saline Red Sea water. Due to its features, the sensors are a prime choice for multiple healthcare applications; for example, they are used for heart rate monitoring, plantar pressure measurements, and tactile sensing.

Ocean warming is a major consequence of climate change, with the surface of the ocean having warmed by 0.11 °C decade-1 over the last 50 years and is estimated to continue to warm by an additional 0.6 - 2.0 °C before the end of the century1. However, there is considerable variability in the rates experienced by different ocean regions, so understanding regional trends is important to inform on possible stresses for marine organisms, particularly in warm seas where organisms may be already operating in the high end of their thermal tolerance. Although the Red Sea is one of the warmest ecosystems on earth, its historical warming trends and thermal evolution remain largely understudied. We characterized the Red Sea's thermal regimes at the basin scale, with a focus on the spatial distribution and changes over time of sea surface temperature maxima, using remotely sensed sea surface temperature data from 1982 - 2015. The overall rate of warming for the Red Sea is 0.17 ± 0.07 °C decade-1, while the northern Red Sea is warming between 0.40 and 0.45 °C decade-1, all exceeding the global rate. Our findings show that the Red Sea is fast warming, which may in the future challenge its organisms and communities.

Body size is a fundamental driver of metabolism, yet it remains unclear whether colonial organisms such as corals conform to the universal ¾-power scaling law. As climate change accelerates metabolic demands, characterizing these scaling relationships is essential to identifying which species are most physiologically vulnerable to environmental shifts. Here, we test whether coral polyp morphological traits can predict aerobic metabolism across a diverse range of reef-building species. We examine relationships between respiration and polyp biovolume, surface area, and corallite width, finding isometric scaling with biovolume and slight positive allometry with surface area, with both exponents close to one. Using median corallite width, we further extrapolate our model to theoretically predict per-polyp respiration for 727 coral species from a publicly available trait database.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The database compiles data (in Arias-Ortiz et al. 2020) on biogeochemical characteristics (density, organic carbon and total nitrogen, stable carbon and nitrogen isotopes and sediment grain size) of mangrove forest soils in Tsimipaika Bay, Madagascar. Pb-210 concentrations of the first 40 cm are included. The dataset compiles data for a total of 10 cores (5 cores from an intact forest and 5 from a deforested area) along with surface water dissolved organic carbon (DOC) concentrations measured at 8 stations. Enquiries about the dataset may be sent to Ariane Arias-Ortiz: aariasortiz@berkeley.edu

Shifts from coral to algal dominance are expected to increase in tropical coral reefs as a result of anthropogenic disturbances. The consequences for key ecosystem functions such as primary productivity, calcification, and nutrient recycling are poorly understood, particularly under changing environmental conditions. We used a novel in situ incubation approach to compare functions of coral- and algae-dominated communities in the central Red Sea bimonthly over an entire year. In situ gross and net community primary productivity, calcification, dissolved organic carbon fluxes, dissolved inorganic nitrogen fluxes, and their respective activation energies were quantified to describe the effects of seasonal changes. Overall, coral-dominated communities exhibited 30% lower net productivity and 10 times higher calcification than algae-dominated communities. Estimated activation energies indicated a higher thermal sensitivity of coral-dominated communities. In these communities, net productivity and calcification were negatively correlated with temperature (>40% and >65% reduction, respectively, with +5°C increase from winter to summer), whereas carbon losses via respiration and dissolved organic carbon release more than doubled at higher temperatures. In contrast, algae-dominated communities doubled net productivity in summer, while calcification and dissolved organic carbon fluxes were unaffected. These results suggest pronounced changes in community functioning associated with coral-algal phase shifts. Algae-dominated communities may outcompete coral-dominated communities because of their higher productivity and carbon retention to support fast biomass accumulation while compromising the formation of important reef framework structures. Higher temperatures likely amplify these functional differences, indicating a high vulnerability of ecosystem functions of coral-dominated communities to temperatures even below coral bleaching thresholds. Our results suggest that ocean warming may not only cause but also amplify coral-algal phase shifts in coral reefs.