Rational Design of Enzymatic Electrodes: Impact of Carbon Nanomaterial Types on the Electrode Performance.

This research focuses on the rational design of porous enzymatic electrodes, using horseradish peroxidase (HRP) as a model biocatalyst. Our goal was to identify the main obstacles to maximizing biocatalyst utilization within complex porous structures and to assess the impact of various carbon nanomaterials on electrode performance. We evaluated as-synthesized carbon nanomaterials, such as Carbon Aerogel, Coral Carbon, and Carbon Hollow Spheres, against the commercially available Vulcan XC72 carbon nanomaterial.

Methods for non-proportional hazards in clinical trials: A systematic review.

For the analysis of time-to-event data, frequently used methods such as the log-rank test or the Cox proportional hazards model are based on the proportional hazards assumption, which is often debatable. Although a wide range of parametric and non-parametric methods for non-proportional hazards has been proposed, there is no consensus on the best approaches. To close this gap, we conducted a systematic literature search to identify statistical methods and software appropriate under non-proportional hazard.

Chemical Kinetic Method for Active-Site Quantification in Fe-N-C Catalysts and Correlation with Molecular Probe and Spectroscopic Site-Counting Methods.

Mononuclear Fe ions ligated by nitrogen (FeN) dispersed on nitrogen-doped carbon (Fe-N-C) serve as active centers for electrocatalytic O reduction and thermocatalytic aerobic oxidations. Despite their promise as replacements for precious metals in a variety of practical applications, such as fuel cells, the discovery of new Fe-N-C catalysts has relied primarily on empirical approaches. In this context, the development of quantitative structure-reactivity relationships and benchmarking of catalysts prepared by different synthetic routes and by different laboratories would be facilitated by the broader adoption of methods to quantify atomically dispersed FeN active centers.

Life cycle of single atom catalysts: a Mössbauer study on degradation and reactivation of tetrapyrrolic Fe-N-C powders.

The degradation of a single-site atomically dispersed, model Fe-N-C powder catalyst with high activity is investigated using cryo-Mössbauer spectroscopy. The results indicate a degradation initiated by an Fe to Fe oxidation due to coordination of oxygen to tetrapyrrolic Fe-N sites at atmospheric conditions (change between characteristic doublets) before iron(III) oxide is formed (sextet). Thermal reactivation can be used to restore substantial catalytic activity of aged Fe-N-C powders.

Association of immediate versus delayed extubation of patients admitted to intensive care units postoperatively and outcomes: A retrospective study.

Aim Of This Study: This study seeks to investigate, whether extubation of tracheally intubated patients admitted to intensive care units (ICU) postoperatively either immediately at the day of admission (day 1) or delayed at the first postoperative day (day 2) is associated with differences in outcomes.

Materials And Methods: We performed a retrospective analysis of data from an Austrian ICU registry. Adult patients admitted between January 1st, 2012 and December 31st, 2019 following elective and emergency surgery, who were intubated at the day 1 and were extubated at day 1 or day 2, were included.

Evaluation of the Specific Activity of M-N-Cs and the Intrinsic Activity of Tetrapyrrolic FeN Sites for the Oxygen Reduction Reaction.

M-N-C electrocatalysts are considered pivotal to replace expensive precious group metal-based materials in electrocatalytic conversions. However, their development is hampered by the limited availability of methods for the evaluation of the intrinsic activity of different active sites, like pyrrolic FeN sites within Fe-N-Cs. Currently, new synthetic procedures based on active-site imprinting followed by an ion exchange reaction, e.

Incidence and Outcomes of Cardiopulmonary Resuscitation in ICUs: Retrospective Cohort Analysis.

Objectives: We aim to describe incidence and outcomes of cardiopulmonary resuscitation (CPR) efforts and their outcomes in ICUs and their changes over time.

Design: Retrospective cohort analysis.

Setting: Patient data documented in the Austrian Center for Documentation and Quality Assurance in Intensive Care database.

Resolving the Dilemma of Fe-N-C Catalysts by the Selective Synthesis of Tetrapyrrolic Active Sites via an Imprinting Strategy.

Combining the abundance and inexpensiveness of their constituent elements with their atomic dispersion, atomically dispersed Fe-N-C catalysts represent the most promising alternative to precious-metal-based materials in proton exchange membrane (PEM) fuel cells. Due to the high temperatures involved in their synthesis and the sensitivity of Fe ions toward carbothermal reduction, current synthetic methods are intrinsically limited in type and amount of the desired, catalytically active Fe-N sites, and high active site densities have been out of reach (dilemma of Fe-N-C catalysts). We herein identify a paradigm change in the synthesis of Fe-N-C catalysts arising from the developments of other M-N-C single-atom catalysts.

Reliability of mechanical ventilation during continuous chest compressions: a crossover study of transport ventilators in a human cadaver model of CPR.

Background: Previous studies have stated that hyperventilation often occurs in cardiopulmonary resuscitation (CPR) mainly due to excessive ventilation frequencies, especially when a manual valve bag is used. Transport ventilators may provide mandatory ventilation with predetermined tidal volumes and without the risk of hyperventilation. Nonetheless, interactions between chest compressions and ventilations are likely to occur.

Association of Acute Kidney Injury Receiving Kidney Replacement Therapy With Prognosis of Critically Ill Patients With and Without Cancer: A Retrospective Study.

Objectives: To assess outcomes of cancer patients receiving kidney replacement therapy due to acute kidney injury in ICUs and compare these with other patient groups receiving kidney replacement therapy in ICUs.

Design: Retrospective registry analysis.

Setting: Prospectively collected database of 296,424 ICU patients.

Factors associated with physician decision making on withholding cardiopulmonary resuscitation in prehospital medicine.

This study seeks to identify factors that are associated with decisions of prehospital physicians to start (continue, if ongoing) or withhold (terminate, if ongoing) CPR in patients with OHCA. We conducted a retrospective study using anonymised data from a prehospital physician response system. Data on patients attended for cardiac arrest between January 1st, 2010 and December 31st, 2018 except babies at birth were included.

Adsorption therapy in critically ill with septic shock and acute kidney injury: a retrospective and prospective cohort study.

Background: Haemoadsorption has been described as an effective way to control increased pro- and anti-inflammatory mediators ("cytokine storm") in septic shock patients. No prospective or randomised clinical study has yet confirmed these results. However, no study has yet prospectively specifically investigated patients in severe septic shock with sepsis-associated acute kidney injury (SA-AKI).

Gas sorption porosimetry for the evaluation of hard carbons as anodes for Li- and Na-ion batteries.

Hard carbons are promising candidates for high-capacity anode materials in alkali metal-ion batteries, such as lithium- and sodium-ion batteries. High reversible capacities are often coming along with high irreversible capacity losses during the first cycles, limiting commercial viability. The trade-off to maximize the reversible capacities and simultaneously minimizing irreversible losses can be achieved by tuning the exact architecture of the subnanometric pore system inside the carbon particles.

Association of Body Mass Index and Outcome in Acutely Ill Patients With Chronic Kidney Disease Requiring Intensive Care Therapy.

Objective: An association of body mass index (BMI) and outcome, the "obesity paradox," has been described in patients with chronic kidney disease (CKD) and end-stage renal disease. We sought to assess whether a potential beneficial effect of a high body mass is also seen in CKD patients with critical illness.

Methods: In a retrospective analysis of a prospectively collected database of 123,416 patients from 107 Austrian intensive care units (ICUs) in whom BMI was available, the association of 6 groups of BMI and hospital mortality was assessed in 12,206 patients with CKD 3-5 by univariate and multivariate logistic regression analyses.

Time of Day and its Association with Risk of Death and Chance of Discharge in Critically Ill Patients: A Retrospective Study.

Outcomes following admission to intensive care units (ICU) may vary with time and day. This study investigated associations between time of day and risk of ICU mortality and chance of ICU discharge in acute ICU admissions. Adult patients (age ≥ 18 years) who were admitted to ICUs participating in the Austrian intensive care database due to medical or surgical urgencies and emergencies between January 2012 and December 2016 were included in this retrospective study.

Sol-gel chemistry in molten Brønsted acids towards "activated" carbons and beyond.

"Chemical activation" using Brønsted acids as chemical agents is widely used to generate activated carbons for various sorption applications. Commercially relevant is especially a process using phosphoric acid as activating agent applied to abundant and inexpensive biomass such as wood or coconut shells. In this manuscript, we revisit the porogenesis mechanism based on experiments involving molecular model compounds and oxygen-free polymer precursors, as well as different molten acids as activating agents.

Fundamental Insights into the Reductive Covalent Cross-Linking of Single-Walled Carbon Nanotubes.

Single-walled carbon nanotubes (SWCNT) have been covalently cross-linked via a reductive functionalization pathway, utilizing negatively charged carbon nanotubides (KC). We have compared the use of difunctional linkers acting as molecular pillars between the nanotubes, namely, p-diiodobenzene, p-diiodobiphenyl, benzene-4,4'-bis(diazonium), and 1,1'-biphenyl-4,4'-bis(diazonium) salts as electrophiles. We have employed statistical Raman spectroscopy (SRS), a forefront characterization tool consisting of thermogravimetric analysis coupled with gas chromatography and mass spectrometry (TG-GC-MS) and aberration-corrected high-resolution transmission electron microscopy imaging series at 80 kV to unambiguously demonstrate the covalent binding of the molecular linkers.

Weekends affect mortality risk and chance of discharge in critically ill patients: a retrospective study in the Austrian registry for intensive care.

Background: In this study, we primarily investigated whether ICU admission or ICU stay at weekends (Saturday and Sunday) is associated with a different risk of ICU mortality or chance of ICU discharge than ICU admission or ICU stay on weekdays (Monday to Friday). Secondarily, we analysed whether weekend ICU admission or ICU stay influences risk of hospital mortality or chance of hospital discharge.

Methods: A retrospective study was performed for all adult patients admitted to 119 ICUs participating in the benchmarking project of the Austrian Centre for Documentation and Quality Assurance in Intensive Care (ASDI) between 2012 and 2015.

Importance of non-intrinsic platinum dissolution in Pt/C composite fuel cell catalysts.

The dissolution of different platinum-based nanoparticles deposited on a commercial high-surface area carbon (HSAC) support in thin catalyst films is investigated using a highly sensitive electrochemical flow cell (EFC) coupled to an inductively coupled plasma mass spectrometer (ICP-MS). The previously reported particle-size-dependent dissolution of Pt is confirmed on selected industrial samples with a mean Pt particle size ranging from 1 to 4.8 nm.

Evaluation of clinical practice in perioperative patient blood management.

Background: Several guidelines have been published to facilitate implementation of patient blood management (PBM). This study was performed to evaluate clinical practices in PBM.

Methods: An online survey based on the guidelines for the management of severe perioperative bleeding from the European Society of Anaesthesiology (ESA) was conducted among ESA members.

Vertically Aligned Two-Dimensional Graphene-Metal Hydroxide Hybrid Arrays for Li-O Batteries.

Lithium oxygen batteries (LOBs) are a very promising upcoming technology which, however, still suffers from low lifespan and dramatic capacities fading. Solid discharge products increase the contact resistance and block the electrochemically active electrodes. The resulting high oxidative potentials and formation of LiCO due to electrolyte and carbon electrode decomposition at the positive electrode lead to irreversible deactivation of oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) sites.

High-Performance Carbon Aerogel Air Cathodes for Microbial Fuel Cells.

Microbial fuel cells (MFCs) can generate electricity from the oxidation of organic substrates using anodic exoelectrogenic bacteria and have great potential for harvesting electric energy from wastewater. Improving oxygen reduction reaction (ORR) performance at a neutral pH is needed for efficient energy production. Here we show a nitrogen doped (≈4 wt%) ionothermal carbon aerogel (NDC) with a high surface area, large pore volume, and hierarchical porosity, with good electrocatalytic properties for ORR in MFCs.

Nitro Lignin-Derived Nitrogen-Doped Carbon as an Efficient and Sustainable Electrocatalyst for Oxygen Reduction.

The use of lignin as a precursor for the synthesis of materials is nowadays considered very interesting from a sustainability standpoint. Here we illustrate the synthesis of a micro-, meso-, and macroporous nitrogen-doped carbon (NDC) using lignin extracted from beech wood via alkaline hydrothermal treatment and successively functionalized via aromatic nitration. The so obtained material is thus carbonized in the eutectic salt melt KCl/ZnCl2.

Merging Single-Atom-Dispersed Silver and Carbon Nitride to a Joint Electronic System via Copolymerization with Silver Tricyanomethanide.

Herein, we present an approach to create a hybrid between single-atom-dispersed silver and a carbon nitride polymer. Silver tricyanomethanide (AgTCM) is used as a reactive comonomer during templated carbon nitride synthesis to introduce both negative charges and silver atoms/ions to the system. The successful introduction of the extra electron density under the formation of a delocalized joint electronic system is proven by photoluminescence measurements, X-ray photoelectron spectroscopy investigations, and measurements of surface ζ-potential.