Atomic structure of Mn wires on Si(001) resolved by scanning tunneling microscopy

At submonolayer coverage, Mn forms atomic wires on the Si(001) surface oriented perpendicular to the underlying Si dimer rows. While many other elements form symmetric dimer wires at room temperature, we show that Mn wires have an asymmetric appearance and pin the Si dimers nearby. We find that an atomic configuration with a Mn trimer unit cell can explain these observations due to the interplay between the Si dimer buckling phase near the wire and the orientation of the Mn trimer. We study the resulting four wire configurations in detail using high-resolution scanning tunneling microscopy (STM) imaging and compare our findings with STM images simulated by density functional theory.Comment: 4 pages, 4 figure

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

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

Formalizing Fixed-Point Theory in PVS

We describe an encoding of major parts of domain theory in the PVS extension of the simply-typed -calculus; these encodings consist of: ffl Formalizations of basic structures like partial orders and complete partial orders (domains). ffl Various domain constructions. ffl Notions related to monotonic functions and continuous functions. ffl Knaster-Tarski fixed-point theorems for monotonic and continuous functions; the proof of this theorem requires Zorn's lemma which has been derived from Hilbert's choice operator. ffl Scott's fixed-point induction for admissible predicates and various variations of fixed-point induction like Park's lemma. Altogether, these encodings form a conservative extension of the underlying PVS logic, since all developments are purely definitional. Most of our proofs are straightforward transcriptions of textbook knowledge. The purpose of this work, however, was not to merely reproduce textbook knowledge. To the contrary, our main motivation derived from ou..

Generic Compilation Schemes for Simple Programming Constructs

datatype Expr and an evaluation function eval ( 77 ) then define syntax and semantics of expressions where the state (SState) is defined as a mapping from identifiers to values. 77 % --- semantics of expressions --- eval(e:Expr)(s:SState) : RECURSIVE Value = CASES e OF const(val) : val, varid(name) : s(name), unopr(op,arg) : MUnop(op)(eval(arg)(s)), binopr(op,left,right) : MBinop(op)(eval(left)(s), eval(right)(s)) ENDCASES MEASURE e BY !! Since boolean expressions are treated in a similar way as expressions, we do not define them explicitly but instead suppose that an (uninterpreted) type BExp together with an evaluation function eval bexp : [BExp -? [SState -? bool]] is given. Syntax and semantics of statements are defined by importing the generic theories for simple statements and control structures: % --- import syntax and semantics of simple statements IMPORTING simplestatements[VarId, Expr, Value, eval] % --- import syntax and semantics of control structures IMPORTING ctrlstruc[B..

The TYPELAB Specification and Verification Environment

Introduction Typelab is an experimental environment that permits the specification of software and hardware systems in a modular fashion. Modules are first-class objects that can be manipulated in different ways, for example through refinement in a stepwise process. A high degree of abstraction and good reuse properties are achieved by genericity. The specification language of Typelab is based on a very expressive type theory, the Extended Calculus of Constructions [Luo94], which gives the system a sound semantic foundation. The pure type theory has been augmented by syntactic constructs that permit an intuitive handling of the entities managed by the system. Typelab comprises a proof assistant which is primarily thought to be used as an interactive proof checker. However, a sequentstyle theorem prover has been developed for automatically solving medium-sized problems in restricted fragments of the logic. During a specifi