Minimum-error discrimination between three mirror-symmetric states

We present the optimal measurement strategy for distinguishing between three quantum states exhibiting a mirror symmetry. The three states live in a two-dimensional Hilbert space, and are thus overcomplete. By mirror symmetry we understand that the transformation {|+> -> |+>, |-> -> -|->} leaves the set of states invariant. The obtained measurement strategy minimizes the error probability. An experimental realization for polarized photons, realizable with current technology, is suggested.Comment: 4 pages, 2 figure

Topology-guided functional multiplicity of iron(III)-based metal-organic frameworks

We report here the synthesis and characterization of a new series of mixed-linker iron(III)-based metal-organic frameworks (MOFs) consisting of dicarboxylate linkers (1,4-benzenedicarboxylic acid equivalent to BDC or its amino functionalized derivative) and tricarboxylate linkers (4,4 ',4 ''-[1,3,5-triazine-2,4,6-triyl] tribenzoic acid equivalent to TATB or its nitro functionalized derivative). The resulting mesoporous MOFs with MIL-143 topology are stable under ambient water conditions for 14 d regardless of the functionalization of the organic linkers. Powder X-ray diffraction results reveal high crystallinity of the materials. This structure type is very tolerant to variation in the functional groups (e.g. nitro and/or amino) along the BDC and/or TATB linkers, but is less tolerant to changes in the size of the linkers themselves. It was attempted to replace linear BDC by biphenyl-4,4 '-dicarboxylic acid (BPDC) and trigonal TATB by 2,4-bis(4 '-carboxybiphenyl-4-yl)-6-(4 '-carboxy-2-methoxy-biphenyl-4-yl)-1,3,5-triazine (TAPB). Of the three additional structures made possible by combinations of these linkers (BDC/TAPB, BPDC/TATB, BPDC/TAPB), only one (BDC/TAPB) yields a crystalline product which, like the BDC/TATB crystal, exhibits MIL-143 topology. However, this material is not very stable and collapses upon guest removal. Our results suggest that the incorporation of diverse functional groups on linkers with different geometries in this new iron(III)-based MOF series offers a simple method of precisely tuning the chemical environment within the pores. More importantly, our work expands the scope of mixed-linker MOFs to include a subset of multivariate MOFs characterized by different functionalities in each type of linker

On-Surface Synthesis of Highly Oriented Thin Metal-Organic Framework Films through Vapor-Assisted Conversion

Virmani E, Rotter JM, Maehringer A, et al. On-Surface Synthesis of Highly Oriented Thin Metal-Organic Framework Films through Vapor-Assisted Conversion. JOURNAL OF THE AMERICAN CHEMICAL SOCIETY. 2018;140(14):4812-4819.Controlled on-surface film growth of porous and crystalline frameworks is a central prerequisite for incorporating these materials into functional platforms and operational devices. Here, we present the synthesis of thin zirconium-based metal organic framework (MOF) films by vapor-assisted conversion (VAC). We established protocols adequate for the growth of UiO-66, UiO-66(NH2), UiO-67, and UiO-68(NH2) as well as the porous interpenetrated Zr-organic framework, PPPP-PIZOF-1, as highly oriented thin films. Through the VAC approach, precursors in a cast solution layer on a bare gold surface are reacting to form a porous continuous MOF film, oriented along the [111] crystal axis, by exposure to a solvent vapor at elevated temperature of 100 degrees C and 3 h reaction time. It was found that the concentration of dicarboxylic acid, the modulator, the droplet volume, and the reaction time are vital parameters to be controlled for obtaining oriented MOF films. Using VAC for the MOF film growth on gold surfaces modified with thiol SAMs and on a bare silicon surface yielded oriented MOF films, rendering the VAC process robust toward chemical surface variations. Ethanol sorption experiments show that a substantial part of the material pores is accessible. Thereby, the practical VAC method is an important addition to the toolbox of synthesis methods for thin MOF films. We expect that the VAC approach will open new horizons in the formation of highly defined functional thin MOF films for numerous applications

Expanding the Group of Porous Interpenetrated Zr-Organic Frameworks (PIZOFs) with Linkers of Different Lengths

A Zr-based MOF of the PIZOF type, which consists of two independent and mutually interpenetrating UiO-type frameworks with [Zr₆O₄(OH)₄(O₂C)₁₂] nodes, does not only form with a PEPEP dicarboxylic acid (P = phenylene, E = ethynylene). Also dicarboxylic acids with the shorter PPPP and PEPP spacers were found to give PIZOFs, denoted PPPP-PIZOF and PEPP-PIZOF, respectively. Reducing the spacer length even further to a PEEP segment caused a switchover to the formation of a UiO framework. The hysteresis in the Ar sorption curve of PEPP-PIZOF-1 and the slightly too large amount of combustion residue from PPPP-PIZOF-1 suggest structural defects. These hint at a mismatch between the requirement of the optimal linker length for PIZOF formation and the lengths of the PEPP and PPPP dicarboxylates. Nevertheless, these dicarboxylates prefer the formation of a PIZOF over the formation of a UiO structure. PEPEP-PIZOF-2, PPPP-PIZOF-1, and PEPP-PIZOF-1 are stable in air up to 325, 350, and 300 °C, respectively, and have BET surface areas of 2350, 2020, and 1650 m² g^–1, respectively. PEPEP-PIZOFs, even those with very hydrophilic oligo­(ethylene glycol) side chains on the linkers, are very stable in water and also during drying from a water-wetted state. On the contrary, PEPP-PIZOF-1 and PPPP-PIZOF-1 that had been exposed to water required exchange of water for ethanol before drying to mostly preserve the framework. The results emphasize the importance of differentiating between framework damage caused through hydrolysis in water and through drying from a water-wetted state. The sensitivity of PEPP-PIZOF-1 and PPPP-PIZOF-1 against drying from a water-wetted state may be the consequence of defects. The drying stability of water-wetted PEPEP-PIZOFs lets us suggest that reversible bending of the linkers contributes to the stability of the PEPEP-PIZOFs

Optical coherence tomography in coronary atherosclerosis assessment and intervention

© Springer Nature Limited 2022Since optical coherence tomography (OCT) was first performed in humans two decades ago, this imaging modality has been widely adopted in research on coronary atherosclerosis and adopted clinically for the optimization of percutaneous coronary intervention. In the past 10 years, substantial advances have been made in the understanding of in vivo vascular biology using OCT. Identification by OCT of culprit plaque pathology could potentially lead to a major shift in the management of patients with acute coronary syndromes. Detection by OCT of healed coronary plaque has been important in our understanding of the mechanisms involved in plaque destabilization and healing with the rapid progression of atherosclerosis. Accurate detection by OCT of sequelae from percutaneous coronary interventions that might be missed by angiography could improve clinical outcomes. In addition, OCT has become an essential diagnostic modality for myocardial infarction with non-obstructive coronary arteries. Insight into neoatherosclerosis from OCT could improve our understanding of the mechanisms of very late stent thrombosis. The appropriate use of OCT depends on accurate interpretation and understanding of the clinical significance of OCT findings. In this Review, we summarize the state of the art in cardiac OCT and facilitate the uniform use of this modality in coronary atherosclerosis. Contributions have been made by clinicians and investigators worldwide with extensive experience in OCT, with the aim that this document will serve as a standard reference for future research and clinical application.info:eu-repo/semantics/publishedVersio