An EMF cell with a nitrogen solid electrolyte-on the transference of nitrogen ions in yttria-stabilized zirconia

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The mobility and electrochemical activity of nitrogen inside and/or at the surface of ionic compounds is of fundamental, as well as of possibly practical, relevance. In order to better understand the role of nitrogen anions in solid electrolytes, we measured the transference number of nitrogen in yttria-stabilized zirconia (YSZ) by a concentration cell technique as a function of oxygen activity at different temperatures in the range of 1023 ≤ T/K ≤ 1123. YSZ doped with 1.9 wt% of N (YSZ:N) turned out to have an appreciable nitrogen transference number, which increased from 0 to 0.1 with decreasing oxygen activity in the range of −20 < logaO2 < −14. The stability of N in YSZ:N, however, has yet to be elucidated under oxidizing conditions.DFG, SPP 1136, Substitutionseffekte in ionischen Festkörper

An EMF cell with a nitrogen solid electrolyte-on the transference of nitrogen ions in yttria-stabilized zirconia

Dieser Beitrag ist mit Zustimmung des Rechteinhabers aufgrund einer (DFG geförderten) Allianz- bzw. Nationallizenz frei zugänglich.This publication is with permission of the rights owner freely accessible due to an Alliance licence and a national licence (funded by the DFG, German Research Foundation) respectively.The mobility and electrochemical activity of nitrogen inside and/or at the surface of ionic compounds is of fundamental, as well as of possibly practical, relevance. In order to better understand the role of nitrogen anions in solid electrolytes, we measured the transference number of nitrogen in yttria-stabilized zirconia (YSZ) by a concentration cell technique as a function of oxygen activity at different temperatures in the range of 1023 ≤ T/K ≤ 1123. YSZ doped with 1.9 wt% of N (YSZ:N) turned out to have an appreciable nitrogen transference number, which increased from 0 to 0.1 with decreasing oxygen activity in the range of −20 < logaO2 < −14. The stability of N in YSZ:N, however, has yet to be elucidated under oxidizing conditions.DFG, SPP 1136, Substitutionseffekte in ionischen Festkörper

Polymer-Templated Ordered Large-Pore Mesoporous Anatase–Rutile TiO2\mathrm{TiO_2}:Ta Nanocomposite Films: Microstructure, Electrical Conductivity, and Photocatalytic and Photoelectrochemical Properties

We describe the polymer templating of inorganic sol–gel precursors for making thermally stable mesoporous anatase–rutile TiO$_2$:Ta nanocomposite films with high surface area (S$_{BET}$ ≥ 150 m$^2$ g$^{−1}$). Mesostructured films with cubic pore symmetry and pore sizes ranging from 17 nm to 26 nm in diameter were prepared from different diblock copolymers such as polyisobutylene-block-poly(ethylene oxide) and were characterized by various microscopy techniques, grazing incidence small-angle X-ray scattering, X-ray diffraction and Rietveld refinement, X-ray photoelectron spectroscopy, and impedance spectroscopy. Here, we specifically focus on the material with the smaller pores. Our research data establish that (1) the nanoscale structure can be preserved up to 900 °C, (2) anatase is the primary phase, (3) the phase composition remains constant over a broad temperature range, (4) anatase-to-rutile transformation and formation of $L$-Ta$_2$O$_5$ do not occur below 800 °C, and that (5) the films contain a non-negligible fraction of Ti$^{3+}$ species. The latter results in a room-temperature electrical conductivity (∼2.4 mS cm$^{−1}$) much higher than that reported for stoichiometric TiO$_2$. Compositionally, the material can be described by the chemical formula Ta$_{0.24}$Ti$_{0.75}$O$_2$±δ. The mesoporous nanocomposite films (E$_g$ ≈ 3.4 eV) also display interesting photocatalytic properties and photoelectrochemical activity which makes them interesting for different applications such as wastewater detoxification

Treatment recommendations within the leeway of clinical guidelines

$\textbf {Background:}$ Recommending the optimal treatment for an individual patient requires a well-balanced consideration of various medical, social and ethical factors. The interplay of these factors, interpretation of the patient’s situation and understanding of the existing clinical guidelines can lead to divergent therapy recommendations, depending on the attending physician. Gaining a better understanding of the individual process of medical decision-making and the differences occurring will support the delivery of optimal individualized care within the clinical setting. $\textbf {Methods:}$ A case vignette of a 64-year-old patient with locally advanced pancreatic adenocarcinoma was discussed with oncologists in 14 qualitative, semi-structured interviews at two academic institutions. Relevant factors that emerged were ranked by the participants using the Q card sorting method. Qualitative data analysis and descriptive statistics were performed. $\textbf {Results:}$ Oncologists recommend different therapeutic approaches within the leeway of the relevant clinical guidelines. One group of participants endorses a rather aggressive and potentially curative approach with a combination chemotherapy following the FOLFIRINOX protocol to provide the patient with the best chances of resectability. The second group suggests a milder chemotherapy approach with gemcitabine, highlighting the palliative approach and the patient’s quality of life. Clinical guidelines are generally seen as an important point of reference, but are complicated to apply in highly individual cases. $\textbf {Conclusion:}$ The physician’s individual assessment of factors, such as biological age, general condition or prognosis, plays a decisive role in treatment recommendations, particularly in those cases which are not fully covered by guidelines. Judgment and discretion remain crucial in clinical decision-making and cannot and should not be fully ruled out by evidence-based guidelines. Therefore, a more comprehensive reflection on the interaction between evidence-based medicine and the physician’s estimation of each individual case is desirable. Knowledge of existing barriers can enhance the implementation of guidelines, for example, through medical education

Stereotactic cisternal lavage in patients with aneurysmal subarachnoid hemorrhage with urokinase and nimodipine for the prevention of secondary brain injury (SPLASH): study protocol for a randomized controlled trial

Background!#!Delayed cerebral infarction (DCI) is a major cause of death and poor neurological outcome in patients with aneurysmal subarachnoid hemorrhage (aSAH). Direct intrathecal therapies with fibrinolytic and spasmolytic drugs have appeared promising in clinical trials. However, access to the subarachnoid space for intrathecal drug administration is an unsolved problem so far, especially in patients with endovascular aneurysm securing. We investigate a therapy protocol based on stereotactic catheter ventriculocisternostomy (STX-VCS), a new approach to overcome this problem. The primary objective of this study is to assess whether cisternal lavage with urokinase, nimodipine, and Ringer's solution administered via a stereotactically implanted catheter into the basal cisterns (= investigational treatment (IT)) is safe and improves neurological outcome in patients with aSAH.!##!Methods!#!This is a randomized, controlled, parallel-group, open-label phase II trial. Fifty-four patients with severe aSAH (WFNS grade ≥ 3) will be enrolled at one academic tertiary care center in Southern Germany. Patients will be randomized at a ratio of 1:1 to receive either standard of care only or standard of care plus the IT. The primary endpoint is the proportion of subjects with a favorable outcome on the Modified Rankin Scale (defined as mRS 0-3) at 6 months after aSAH. Further clinical and surrogate outcome parameters are defined as secondary endpoints.!##!Discussion!#!New approaches for the prevention and therapy of secondary brain injury in patients with aSAH are urgently needed. We propose this RCT to assess the clinical safety and efficacy of a novel therapy protocol for intrathecal administration of urokinase, nimodipine, and Ringer's solution.!##!Trial registration!#!Deutsches Register Klinischer Studien (German Clinical Trials Register), DRKS00015645 . Registered on 8 May 2019

Diverging prefrontal cortex fiber connection routes to the subthalamic nucleus and the mesencephalic ventral tegmentum investigated with long range (normative) and short range (ex-vivo high resolution) 7T DTI

Coenen VA, Dobrossy MD, Teo SJ, et al. Diverging prefrontal cortex fiber connection routes to the subthalamic nucleus and the mesencephalic ventral tegmentum investigated with long range (normative) and short range (ex-vivo high resolution) 7T DTI. Brain structure &amp; function. 2021.Uncertainties concerning anatomy and function of cortico-subcortical projections have arisen during the recent years. A clear distinction between cortico-subthalamic (hyperdirect) and cortico-tegmental projections (superolateral medial forebrain bundle, slMFB) so far is elusive. Deep Brain Stimulation (DBS) of the slMFB (for major depression, MD and obsessive compulsive disorders, OCD) has on the one hand been interpreted as actually involving limbic (prefrontal) hyperdirect pathways. On the other hand slMFB's stimulation region in the mesencephalic ventral tegmentum is said to impact on other structures too, going beyond the antidepressant (or anti OCD) efficacy of sole modulation of the cortico-tegmental reward-associated pathways. We have here used a normative diffusion MRT template (HCP, n=80) for long-range tractography and augmented this dataset with ex-vivo high resolution data (n=1) in a stochastic brain space. We compared this data with histological information and used the high resolution ex-vivo data set to scrutinize the mesencephalic tegmentum for small fiber pathways present. Our work resolves an existing ambiguity between slMFB and prefrontal hyperdirect pathways which-for the first time-are described as co-existent. DBS of the slMFB does not appear to modulate prefrontal hyperdirect cortico-subthalamic but rather cortico-tegmental projections. Smaller fiber structures in the target region-as far as they can be discerned-appear not to be involved in slMFB DBS. Our work enfeebles previous anatomical criticism and strengthens the position of the slMFB DBS target for its use in MD and OCD. © 2021. The Author(s)