Impact of the Chlorination of Lithium Argyrodites on the Electrolyte/Cathode Interface in Solid‐State Batteries

Lithium argyrodite-type electrolytes are regarded as promising electrolytes due to their high ionic conductivity and good processability. Chemical modifications to increase ionic conductivity have already been demonstrated, but the influence of these modifications on interfacial stability remains so far unknown. In this work, we study Li6PS5Cl and Li5.5PS4.5Cl1.5 to investigate the influence of halogenation on the electrochemical decomposition of the solid electrolyte and the chemical degradation mechanism at the cathode interface in depth. Electrochemical measurements, gas analysis and time-of-flight secondary ion mass spectrometry indicate that the Li5.5PS4.5Cl1.5 shows pronounced electrochemical decomposition at lower potentials. The chemical reaction at higher voltages leads to more gaseous degradation products, but a lower fraction of solid oxygenated phosphorous and sulfur species. This in turn leads to a decreased interfacial resistance and thus a higher cell performance

The Role of Stereotactic Radiosurgery in the Management of Foramen Magnum Meningiomas—A Multicenter Analysis and Review of the Literature

Background: Foramen magnum meningiomas (FMMs) represent a considerable neurosurgical challenge given their location and potential morbidity. Stereotactic radiosurgery (SRS) is an established non-invasive treatment modality for various benign and malignant brain tumors. However, reports on single-session or multisession SRS for the management and treatment of FMMs are exceedingly rare. We report the largest FMM SRS series to date and describe our multicenter treatment experience utilizing robotic radiosurgery. Methods: Patients who underwent SRS between 2005 and 2020 as a treatment for a FMM at six different centers were eligible for analysis. Results: Sixty-two patients met the inclusion criteria. The median follow-up was 28.9 months. The median prescription dose and isodose line were 14 Gy and 70%, respectively. Single-session SRS accounted for 81% of treatments. The remaining patients received three to five fractions, with doses ranging from 19.5 to 25 Gy. Ten (16%) patients were treated for a tumor recurrence after surgery, and thirteen (21%) underwent adjuvant treatment. The remaining 39 FMMs (63%) received SRS as their primary treatment. For patients with an upfront surgical resection, histopathological examination revealed 22 World Health Organization grade I tumors and one grade II FMM. The median tumor volume was 2.6 cubic centimeters. No local failures were observed throughout the available follow-up, including patients with a follow-up ≥ five years (16 patients), leading to an overall local control of 100%. Tumor volume significantly decreased after treatment, with a median volume reduction of 21% at the last available follow-up (p < 0.01). The one-, three-, and five-year progression-free survival were 100%, 96.6%, and 93.0%, respectively. Most patients showed stable (47%) or improved (21%) neurological deficits at the last follow-up. No high-grade adverse events were observed. Conclusions: SRS is an effective and safe treatment modality for FMMs. Despite the paucity of available data and previous reports, SRS should be considered for selected patients, especially those with subtotal tumor resections, recurrences, and patients not suitable for surgery

Stable and Active Oxygen Reduction Catalysts with Reduced Noble Metal Loadings through Potential Triggered Support Passivation

The development of stable, cost‐efficient and active materials is one of the main challenges in catalysis. The utilization of platinum in the electroreduction of oxygen is a salient example where the development of new material combinations has led to a drastic increase in specific activity compared to bare platinum. These material classes comprise nanostructured thin films, platinum alloys, shape‐controlled nanostructures and core–shell architectures. Excessive platinum substitution, however, leads to structural and catalytic instabilities. Herein, we introduce a catalyst concept that comprises the use of an atomically thin platinum film deposited on a potential‐triggered passivating support. The model catalyst exhibits an equal specific activity with higher atom utilization compared to bulk platinum. By using potential‐triggered passivation of titanium carbide, irregularities in the Pt film heal out via the formation of insoluble oxide species at the solid/liquid interface. The adaptation of the described catalyst design to the nanoscale and to high‐surface‐area structures highlight the potential for stable, passivating catalyst systems for various electrocatalytic reactions such as the oxygen reduction reaction

Effect of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker initiation on organ support-free days in patients hospitalized with COVID-19

IMPORTANCE Overactivation of the renin-angiotensin system (RAS) may contribute to poor clinical outcomes in patients with COVID-19. Objective To determine whether angiotensin-converting enzyme (ACE) inhibitor or angiotensin receptor blocker (ARB) initiation improves outcomes in patients hospitalized for COVID-19. DESIGN, SETTING, AND PARTICIPANTS In an ongoing, adaptive platform randomized clinical trial, 721 critically ill and 58 non–critically ill hospitalized adults were randomized to receive an RAS inhibitor or control between March 16, 2021, and February 25, 2022, at 69 sites in 7 countries (final follow-up on June 1, 2022). INTERVENTIONS Patients were randomized to receive open-label initiation of an ACE inhibitor (n = 257), ARB (n = 248), ARB in combination with DMX-200 (a chemokine receptor-2 inhibitor; n = 10), or no RAS inhibitor (control; n = 264) for up to 10 days. MAIN OUTCOMES AND MEASURES The primary outcome was organ support–free days, a composite of hospital survival and days alive without cardiovascular or respiratory organ support through 21 days. The primary analysis was a bayesian cumulative logistic model. Odds ratios (ORs) greater than 1 represent improved outcomes. RESULTS On February 25, 2022, enrollment was discontinued due to safety concerns. Among 679 critically ill patients with available primary outcome data, the median age was 56 years and 239 participants (35.2%) were women. Median (IQR) organ support–free days among critically ill patients was 10 (–1 to 16) in the ACE inhibitor group (n = 231), 8 (–1 to 17) in the ARB group (n = 217), and 12 (0 to 17) in the control group (n = 231) (median adjusted odds ratios of 0.77 [95% bayesian credible interval, 0.58-1.06] for improvement for ACE inhibitor and 0.76 [95% credible interval, 0.56-1.05] for ARB compared with control). The posterior probabilities that ACE inhibitors and ARBs worsened organ support–free days compared with control were 94.9% and 95.4%, respectively. Hospital survival occurred in 166 of 231 critically ill participants (71.9%) in the ACE inhibitor group, 152 of 217 (70.0%) in the ARB group, and 182 of 231 (78.8%) in the control group (posterior probabilities that ACE inhibitor and ARB worsened hospital survival compared with control were 95.3% and 98.1%, respectively). CONCLUSIONS AND RELEVANCE In this trial, among critically ill adults with COVID-19, initiation of an ACE inhibitor or ARB did not improve, and likely worsened, clinical outcomes. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT0273570

Transition Metal-Carbon Bond Enthalpies as Descriptor for the Electrochemical Stability of Transition Metal Carbides in Electrocatalytic Applications

Transition metal carbides are used for various applications such as hard coating, heterogeneous catalysis, catalyst support material or coatings in fuel cell applications. However, little is known about the stability of their electrochemically active surface in aqueous electrolytes. Herein, the transition metal—carbon bond enthalpy is proposed as stability criterion for various transition metal carbides. The basis is an oxidation mechanism where the rate determining step is the metal—carbon bond cleavage under acidic conditions which was supported by a detailed corrosion study on hexagonal tungsten carbide. In situ flow cell measurements that were coupled to an inductively coupled plasma mass spectrometer corroborated experimentally the linear dependency of the oxidation overpotential on the transition metal—carbon bond enthalpy. The proposed model allows the estimation of the activation overpotential for electrochemical carbide oxidation resulting in a maximized stabilization for carbides in the 4th group (Ti, Zr, Hf). Together with the calculated thermodynamic oxidation potentials, TiC and VC exhibit the highest experimental oxidation potentials (0.85 VRHE). The model can be used for preselecting possible carbide materials for various electrochemical reactions

Transition Metal—Carbon Bond Enthalpies as Descriptor for the Electrochemical Stability of Transition Metal Carbides in Electrocatalytic Applications

Transition metal carbides are used for various applications such as hard coating, heterogeneous catalysis, catalyst support material or coatings in fuel cell applications. However, little is known about the stability of their electrochemically active surface in aqueous electrolytes. Herein, the transition metal—carbon bond enthalpy is proposed as stability criterion for various transition metal carbides. The basis is an oxidation mechanism where the rate determining step is the metal—carbon bond cleavage under acidic conditions which was supported by a detailed corrosion study on hexagonal tungsten carbide. In situ flow cell measurements that were coupled to an inductively coupled plasma mass spectrometer corroborated experimentally the linear dependency of the oxidation overpotential on the transition metal—carbon bond enthalpy. The proposed model allows the estimation of the activation overpotential for electrochemical carbide oxidation resulting in a maximized stabilization for carbides in the 4th group (Ti, Zr, Hf). Together with the calculated thermodynamic oxidation potentials, TiC and VC exhibit the highest experimental oxidation potentials (0.85 VRHE). The model can be used for preselecting possible carbide materials for various electrochemical reactions

Impact of prescription isodose level and collimator selection on dose homogeneity and plan quality in robotic radiosurgery

Purpose!#!In stereotactic radiosurgery (SRS), prescription isodoses and resulting dose homogeneities vary widely across different platforms and clinical entities. Our goal was to investigate the physical limitations of generating dose distributions with an intended level of homogeneity in robotic SRS.!##!Methods!#!Treatment plans for non-isocentric irradiation of 4 spherical phantom targets (volume 0.27-7.70 ml) and 4 clinical targets (volume 0.50-5.70 ml) were calculated using Sequential (phantom) or VOLO!##!Results!#!Dose conformity was generally high (nCI ≤ 1.25) and varied little with PIL. For all targets and collimator sets, V12Gy was highest for PIL ≥ 80% and lowest for PIL ≤ 65%. The impact of PIL on V12Gy was highest for isocentric irradiation and lowest for clinical targets (VOLO!##!Conclusion!#!Inhomogeneous dose distributions with PIL ≤ 70% can be used to minimize dose to normal tissue. PIL ≥ 90% is associated with a marked and significant increase in off-target dose exposure. Careful selection of collimators during planning is even more important

Stereotactic radiosurgery and radiotherapy for brainstem metastases: An international multicenter analysis.

Brainstem metastases (BSM) present a significant neuro-oncological challenge, resulting in profound neurological deficits and poor survival outcomes. Stereotactic radiosurgery (SRS) and fractionated stereotactic radiotherapy (FSRT) offer promising therapeutic avenues for BSM despite their precarious location. This international multicenter study investigates the efficacy and safety of SRS and FSRT in 136 patients with 144 BSM treated at nine institutions from 2005 to 2022. The median radiographic and clinical follow-up periods were 6.8 and 9.4 months, respectively. Predominantly, patients with BSM were managed with SRS (69.4%). The median prescription dose and isodose line for SRS were 18 Gy and 65%, respectively, while for FSRT, the median prescription dose was 21 Gy with a median isodose line of 70%. The 12-, 24-, and 36-month local control (LC) rates were 82.9%, 71.4%, and 61.2%, respectively. Corresponding overall survival rates at these time points were 61.1%, 34.7%, and 19.3%. In the multivariable Cox regression analysis for LC, only the minimum biologically effective dose was significantly associated with LC, favoring higher doses for improved control (in Gy, hazard ratio [HR]: 0.86, p < .01). Regarding overall survival, good performance status (Karnofsky performance status, ≥90%; HR: 0.43, p < .01) and prior whole brain radiotherapy (HR: 2.52, p < .01) emerged as associated factors. In 14 BSM (9.7%), treatment-related adverse events were noted, with a total of five (3.4%) radiation necrosis. SRS and FSRT for BSM exhibit efficacy and safety, making them suitable treatment options for affected patients

Spinodal decomposition of reactively sputtered (V0.64Al0.36)0.49N0.51 thin films

We investigate the decomposition mechanisms of metastable cubic (c-)(V$_{0.64}$Al$_{0.36}$)$_{0.49}$N$_{0.51}$ thin films, grown by reactive high power pulsed magnetron sputtering, by combination of structural and compositional characterization at the nanometer scale with density functional theory (DFT) calculations. Based on thermodynamic considerations of $∂^2∆G/∂x^2 < 0$, spinodal decomposition is expected for c-V$_{1-x}$Al$_x$N with $x ≥$ 0.35. While no indications for spinodal decomposition are observable from laboratory and synchroton diffraction data after annealing in Ar atmosphere at 1300 °C, the formation of wurtzite (w-)AlN is evident after annealing at 900 °C by utilizing high energy synchrotron X-ray diffraction. However, the complementary nature of elemental V and Al maps, obtained by energy dispersive X-ray spectroscopy in scanning transmission electron microscopy mode, imply spinodal decomposition of c-(V$_{0.64}$Al$_{0.36}$)$_{0.49}$N$_{0.51}$ into V- and Al-rich cubic nitride phases after annealing at 900 °C. These chemical modulations are quantified by atom probe tomography and maximum variations of x in V$_{1-x}$Al$_x$N are in the range of 0.36 to 0.50. The magnitude of the compositional modulations is enhanced after annealing at 1100 °C as x varies on average between 0.30 and 0.61, while the modulation wavelength remains unchanged at approximately 8 nm. Based on DFT data, the local x variation from 0.30 to 0.61 would cause lattice parameter variations from 4.111 to 4.099 Å. This difference corresponds to a shift of the (200) peak from 44.0 to 44.1°. As the maximum decomposition-induced peak separation magnitude of 0.1° is significantly smaller than the measured full width at half maximum of 0.4°, spinodal decomposition cannot be unravelled by diffraction data. However, consistent with DFT predictions, spinodal decomposition in c-(V$_{0.64}$Al$_{0.36}$)$_{0.49}$N$_{0.51}$ is revealed by chemical composition characterization at the nanometer scale

Stable and Active Oxygen Reduction Catalysts with Reduced Noble Metal Loadings through Potential Triggered Support Passivation

The development of stable, cost-efficient and activematerials is one of the main challenges in catalysis. Theutilization of platinum in the electro-reduction of oxygen is asalient example where the development of new materialcombinations has led to a drastic increase in specific activitycompared to bare platinum. These material classes comprisenanostructured thin films, platinum-alloys, shape-controllednanostructures or core-shell architectures. Excessive platinumsubstitution, however, leads to structural and catalyticinstabilities. Herein, we introduce a catalyst concept thatcomprises the use of an atomically thin platinum film depositedon a potential-triggered passivating support. The modelcatalyst exhibits a threefold higher specific activity with higheratom utilisation compared to bulk platinum. By using potentialtriggeredpassivation of titanium carbide, irregularities in the Ptfilm heal out via the formation of insoluble oxide species at thesolid/liquid interface. The adaptation of the described catalystdesign to the nanoscale and to high-surface area structureshighlight the potential for stable, passivating catalyst systemsfor various electrocatalytic reactions such as the oxygenreduction reaction