A randomized trial of the efficacy and safety of sequential intravenous/oral moxifloxacin monotherapy versus intravenous piperacillin/tazobactam followed by oral amoxicillin/clavulanate for complicated skin and skin structure infections

Item does not contain fulltextOBJECTIVES: The primary aim of the RELIEF study was to evaluate the efficacy and safety of two sequential intravenous (iv)/oral regimens: moxifloxacin iv/oral versus piperacillin/tazobactam (TZP) iv followed by oral amoxicillin/clavulanate (AMC). PATIENTS AND METHODS: The study had a prospective, randomized, double-dummy, double-blind, multicentre design. Patients >/=18 years were prospectively stratified according to complicated skin and skin structure infection (cSSSI) subtype/diagnosis (major abscess, diabetic foot infection, wound infection or infected ischaemic ulcer), surgical intervention and severity of illness. Diagnoses and disease severity were based on predetermined criteria, documented by repeated photographs, and confirmed by an independent data review committee. Patients were randomized to receive either 400 mg of moxifloxacin iv once daily followed by 400 mg of moxifloxacin orally once daily or 4.0/0.5 g of TZP iv thrice daily followed by 875/125 mg of AMC orally twice daily for 7-21 days. The primary efficacy variable was clinical response at test of cure (TOC) for the per-protocol (PP) population. Clinical efficacy was assessed by the data review committee based on repeated photographs and case descriptions. Clinical trials registry number: NCT 00402727. RESULTS: A total of 813 patients were randomized. Clinical success rates at TOC were similar for moxifloxacin and TZP-AMC in the PP [320/361 (88.6%) versus 275/307 (89.6%), respectively; P = 0.758] and intent-to-treat (ITT) [350/426 (82.2%) versus 305/377 (80.9%), respectively; P = 0.632] populations. Thus, moxifloxacin was non-inferior to TZP-AMC. Bacteriological success rates were high in both treatment arms [moxifloxacin: 432/497 (86.9%) versus TZP-AMC: 370/429 (86.2%), microbiologically valid (MBV) population]. Moxifloxacin was non-inferior to TZP-AMC at TOC in both the MBV and the ITT populations. Both treatments were well tolerated. CONCLUSIONS: Once-daily iv/oral moxifloxacin monotherapy was clinically and bacteriologically non-inferior to iv TZP thrice daily followed by oral AMC twice daily in patients with cSSSIs

Thermal Stability of the Black Perovskite Phase in Cesium Lead Iodide Nanocrystals under Humid Conditions

The equilibrium phase of cesium lead iodide (CsPbI3) at room temperature is yellow and optically inactive due to its indirect band gap. The metastable black phase of CsPbI3 on the other hand exhibits optical properties that are suitable for photovoltaic and light-emitting devices. Here, we examine the stability of the black phase of ligand-stabilized CsPbI3 nanocrystals heated in humid air. Water vapor is known to catalyze the transition of CsPbI3 from the black phase to the yellow phase. Uniform nanocrystals with cube shape were synthesized with capping ligand mixtures of oleylamine and oleic acid or diisooctylphosphinic acid, assembled into superlattices with preferred crystal orientation, and studied using grazing incidence small- and wide-angle X-ray scattering with in situ heating. The black-phase nanocrystals are found to inhabit the γ-orthorhombic phase and do not revert to the equilibrium yellow δ-orthorhombic phase until reaching a relatively high temperature, between 170 and 200 °C, coinciding with superlattice degradation. Copyright © 2019 American Chemical Society

Assembly of Linked Nanocrystal Colloids by Reversible Covalent Bonds

The use of dynamically bonding molecules designed to reversibly link solvent-dispersed nanocrystals (NCs) is a promising strategy to form colloidal assemblies with controlled structure and macroscopic properties. In this work, tin-doped indium oxide NCs are functionalized with ligands that form reversible covalent bonds with linking molecules to drive assembly of NC gels. We monitor gelation using small angle X-ray scattering and characterize how changes in the gel structure affect infrared optical properties arising from the localized surface plasmon resonance of the NCs. The assembly is reversible because of the designed linking chemistry, and we disassemble the gels using two strategies: addition of excess NCs to change the ratio of linking molecules to NCs and addition of a capping molecule that displaces the linking molecules. The assembly behavior is rationalized using a thermodynamic perturbation theory to compute the phase diagram of the NC–linking molecule mixture. Coarse-grained molecular dynamics simulations reveal the competition between loop and bridge linking motifs essential for understanding NC gelation. This combined experimental, computational, and theoretical work provides a platform for controlling and designing the properties of reversible colloidal assemblies that incorporate NC and solvent compositions beyond those compatible with other contemporary (e.g, DNA-based) linking strategies.We would like to acknowledge the UT Mass Spectrometry Facility for their instrumental help and the UT NMR facilities for equipment use and assistance: NIH Grant Number 1 S10 OD021508-01. This work was primarily supported by the National Science Foundation through the Center for Dynamics and Control of Materials: an NSF Materials Research Science and Engineering Center (NSF MRSEC) under Cooperative Agreement DMR-1720595. This work was also supported by NSF Graduate Research Fellowships DGE-1610403 (M.N.D. and S.V.), an Arnold O. Beckman Postdoctoral Fellowship (Z.M.S.), NSF (CHE- 1905263), and the Welch Foundation (F-1848 and F-1696). E.V.A. acknowledges support from the Welch Regents Chair (F-0046). We acknowledge the Texas Advanced Computing Center (TACC) at The University of Texas at Austin for providing HPC resources.Center for Dynamics and Control of Material