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The article focuses on cation-size tuning of a metal-metal bond in a partially ionic crystals. The authors came upon a hypothetical SrTiO2 compound while exploring variants of P4lmmm ABX2 structure. A locally stable structure that was confirmed by computation of phonon modes emerged from DFT calculations.

A letter to the editor is presented in response to an article within the journal's 523 issue in 2015 on the development electronic patient-safety checklists that are devised for specific clinical teams in medical care.

Background: The risk of nosocomial COVID-19 infection for vulnerable aortic stenosis patients and intensive care resource utilization has led to cardiac surgery deferral. Untreated severe symptomatic aortic stenosis has a dismal prognosis. TAVR offers an attractive alternative to surgery as it is not reliant on intensive care resources. We set out to explore the safety and operational efficiency of restructuring a TAVR service and redeploying it to a new non-surgical site during the COVID-19 pandemic.Methods: The institutional prospective service database was retrospectively interrogated for the first 50 consecutive elective TAVR cases prior to and after our institution's operational adaptations for the COVID-19 pandemic. Our endpoints were VARC-2 defined procedural complications, 30-day mortality or re-admission and service efficiency metrics.Results: The profile of patients undergoing TAVR during the pandemic was similar to patients undergoing TAVR prior to the pandemic with the exception of a lower mean age (79 vs 82 years, p < 0.01) and median EuroScore II (3.1% vs 4.6%, p = 0.01). The service restructuring and redeployment contributed to the pandemic-mandated operational efficiency with a reduction in the distribution of pre-admission hospital visits (3 vs 3 visits, p < 0.001) and the time taken from TAVR clinic to procedure (26 vs 77 days, p < 0.0001) when compared to the pre-COVID-19 service. No statistically significant difference was noted in peri-procedural complications and 30-day outcomes, while post-operative length of stay was significantly reduced (2 vs 3 days, p < 0.0001) when compared to pre-COVID-19 practice.Conclusions: TAVR service restructuring and redeployment to align with pandemic-mandated healthcare resource rationalization is safe and feasible. [ABSTRACT FROM AUTHOR]

To evaluate the timing, duration and incidence of bacteremia following invasive dental procedures (IDPs) or activities of daily living (ADL). Eight databases were searched for randomized (RCTs) and nonrandomized controlled trials (nRCTs) evaluating bacteremia before and after IDPs or ADL in healthy individuals. The risk of bias was assessed by RoB 2.0 and ROBINS-I. For the meta-analysis, the primary outcomes were the timing and duration of bacteremia. The secondary outcome was the incidence of bacteremia, measuring the proportion of patients with bacteremia within 5 min after the end of the procedure compared with baseline. We included 64 nRCTs and 25 RCTs. Peak bacteremia occurred within 5 min after the procedure and then decreased over time. Dental extractions showed the highest incidence of bacteremia (62%-66%), followed by scaling and root planing (SRP) (44%-36%) and oral health procedures (OHP) (e.g., dental prophylaxis and dental probing without SRP) (27%-28%). Other ADL (flossing and chewing) (16%) and toothbrushing (8%-26%) resulted in bacteremia as well. The majority of studies had some concerns RCTs or moderate risk of bias nRCTs. Dental extractions, SRP and OHP, are associated with the highest frequency of bacteremia. Toothbrushing, flossing, and chewing also caused bacteremia in lower frequency., (© 2023 Wiley Periodicals LLC.)

Objectives: Cardiac surgery for coronary artery disease was dramatically reduced during the first wave of the COVID-19 pandemic. Many patients with disease ordinarily treated with coronary artery bypass grafting (CABG) instead underwent percutaneous coronary intervention (PCI). We sought to describe 12-month outcomes following PCI in patients who would typically have undergone CABG., Methods: Between March 1 and July 31, 2020, patients who received revascularization with PCI when CABG would have been the primary choice of revascularization were enrolled in the prospective, multicenter UK-ReVasc Registry. We evaluated the following major adverse cardiovascular events at 12 months: all-cause mortality, myocardial infarction, repeat revascularization, stroke, major bleeding, and stent thrombosis., Results: A total of 215 patients were enrolled across 45 PCI centers in the United Kingdom. Twelve-month follow up data were obtained for 97% of the cases. There were 9 deaths (4.3%), 5 myocardial infarctions (2.4%), 12 repeat revascularizations (5.7%), 1 stroke (0.5%), 3 major bleeds (1.4%), and no cases of stent thrombosis. No difference in the primary endpoint was observed between patients who received complete vs incomplete revascularization (residual SYNTAX score £ 8 vs > 8) (P = .22)., Conclusions: In patients with patterns of coronary disease in whom CABG would have been the primary therapeutic choice outside of the pandemic, PCI was associated with acceptable outcomes at 12 months of follow-up. Contemporary randomized trials that compare PCI to CABG in such patient cohorts may be warranted.

Canonical roles for macrophages in mediating the fibrotic response after a heart attack include extracellular matrix turnover and activation of cardiac fibroblasts to initiate collagen deposition. Here we reveal that macrophages directly contribute collagen to the forming post-injury scar. Unbiased transcriptomics shows an upregulation of collagens in both zebrafish and mouse macrophages following heart injury. Adoptive transfer of macrophages, from either collagen-tagged zebrafish or adult mouse GFPtpz-collagen donors, enhances scar formation via cell autonomous production of collagen. In zebrafish, the majority of tagged collagen localises proximal to the injury, within the overlying epicardial region, suggesting a possible distinction between macrophage-deposited collagen and that predominantly laid-down by myofibroblasts. Macrophage-specific targeting of col4a3bpa and cognate col4a1 in zebrafish significantly reduces scarring in cryoinjured hosts. Our findings contrast with the current model of scarring, whereby collagen deposition is exclusively attributed to myofibroblasts, and implicate macrophages as direct contributors to fibrosis during heart repair.

Classically, G-protein-coupled receptors (GPCRs) are thought to activate G protein from the plasma membrane and are subsequently desensitized by β-arrestin (β-arr). However, some GPCRs continue to signal through G protein from internalized compartments, mediated by a GPCR-G protein-β-arr 'megaplex'. Nevertheless, the molecular architecture of the megaplex remains unknown. Here, we present its cryo-electron microscopy structure, which shows simultaneous engagement of human G protein and bovine β-arr to the core and phosphorylated tail, respectively, of a single active human chimeric β 2 -adrenergic receptor with the C-terminal tail of the arginine vasopressin type 2 receptor (β 2 V 2 R). All three components adopt their canonical active conformations, suggesting that a single megaplex GPCR is capable of simultaneously activating G protein and β-arr. Our findings provide a structural basis for GPCR-mediated sustained internalized G protein signaling.

Myocardial revascularisation has the potential to restore ventricular function and improve survival in patients with heart failure due to underlying coronary artery disease. Viability testing is routinely used to identify which patients are likely to benefit, given that revascularisation may entail substantial procedural risk. However, while the concept of viability testing and revascularisation of patients with 'hibernating myocardium' is strongly supported by observational series, randomised studies have failed to demonstrate clear benefit. This divergence in the evidence base is reflected in current European and US guidelines, in which viability testing has a class II recommendation. In this article, we review the current evidence for routine viability testing prior to revascularisation of patients with heart failure, outline its use in clinical practice and discuss ongoing trials in the field., Competing Interests: Conflicts of interestThe authors declare that they have no conflict of interest., (© The Author(s) 2018.)

β-Arrestins (βarrs) interact with G protein-coupled receptors (GPCRs) to desensitize G protein signaling, to initiate signaling on their own, and to mediate receptor endocytosis. Prior structural studies have revealed two unique conformations of GPCR-βarr complexes: the "tail" conformation, with βarr primarily coupled to the phosphorylated GPCR C-terminal tail, and the "core" conformation, where, in addition to the phosphorylated C-terminal tail, βarr is further engaged with the receptor transmembrane core. However, the relationship of these distinct conformations to the various functions of βarrs is unknown. Here, we created a mutant form of βarr lacking the "finger-loop" region, which is unable to form the core conformation but retains the ability to form the tail conformation. We find that the tail conformation preserves the ability to mediate receptor internalization and βarr signaling but not desensitization of G protein signaling. Thus, the two GPCR-βarr conformations can carry out distinct functions.

Classically, G protein-coupled receptor (GPCR) stimulation promotes G protein signaling at the plasma membrane, followed by rapid β-arrestin-mediated desensitization and receptor internalization into endosomes. However, it has been demonstrated that some GPCRs activate G proteins from within internalized cellular compartments, resulting in sustained signaling. We have used a variety of biochemical, biophysical, and cell-based methods to demonstrate the existence, functionality, and architecture of internalized receptor complexes composed of a single GPCR, β-arrestin, and G protein. These super-complexes or "megaplexes" more readily form at receptors that interact strongly with β-arrestins via a C-terminal tail containing clusters of serine/threonine phosphorylation sites. Single-particle electron microscopy analysis of negative-stained purified megaplexes reveals that a single receptor simultaneously binds through its core region with G protein and through its phosphorylated C-terminal tail with β-arrestin. The formation of such megaplexes provides a potential physical basis for the newly appreciated sustained G protein signaling from internalized GPCRs., (Copyright © 2016 Elsevier Inc. All rights reserved.)

Various one-, two- and three-dimensional Group 14 (C, Si, Ge, Sn, and Pb) element structures at P = 1 atm are studied in this work. As expected, coordination number (CN)--not an unambiguous concept for extended structures--plays an important part in the stability of structures. Carbon not only favors four-coordination, but also is quite happy with pi-bonding, allowing three- and even two-coordination to compete. Highly coordinated (CN > 4) discrete carbon molecules are rare; that "saturation of valence" is reflected in the instability of C extended structures with CN > 4. Si and Ge are quite similar to each other in their preferences. They are less biased in their coordination than C, allowing (as their molecular structures do) CN = 5 and 6, but tending towards four-coordination. Sn and Pb 3D structures are very flexible in their bonding, so that in these elements four- to twelve-coordinate structures are close in energy. This lack of discrimination among ordered structures also points to an approach to the liquid state, consistent with the low melting point of Sn and Pb. The Group 14 liquid structures we simulate in molecular dynamics calculations show the expected, effective, first coordination number increase from 5.1 for Si to 10.4 for Pb. A special point of interest emerging from our study is the instability of potential multilayer graphene structures down Group 14. Only for C will these be stable; for all the other Group 14 elements pristine, unprotected, bi- and multilayer graphenes should collapse, forming "vertical" bonds as short as the in-plane ones.

The structures and electronic properties of a number of real and hypothetical ABX(2) compounds sharing (or evolving from) a single P4/mmm structural type are examined. These include the known CaCuO(2) and SrFeO(2) phases. A number of variations of this P4/mmm ABX(2) framework, some obvious, some exotic, all with a chemical motivation, were investigated: A = alkali metal, alkaline earth metal or La, B = Ti, Fe, Cu, or Pt, and X = C, O, S, C(2), H(2), or F. Careful attention was given to the d-orbital splitting patterns and magnetic states (ferromagnetic or antiferromagnetic) of these compounds, as well as their stability gauged by phonon dispersions and energetics. The most interesting as yet unmade compounds that emerged were (a) a carbide SrFe(C(2))(2), containing C(2) units with a C-C distance of 1.267 A, (b) an AeTiO(2) series, with Ti-Ti bonding, part sigma, part pi, tuned by the Ae(2+) cation size, and (c) NaPtF(2), for which a second structure was found, containing a hexagonal layering of (PtF(2))(-) molecules.

In a theoretical study of a "defect perovskite" structure of stoichiometry AeTiO(2) (AE = alkaline earth metal, Be, Mg, Ca, Sr, and Ba), we find substantial Ti-Ti bonding tuned by the size of the Ae(2+) cation. The bonding is one-dimensional, partially sigma, partially pi. These formal d(2) systems are expected to be nonmagnetic and metallic. A competing (for same Ae) structural alternative, an ordered rock-salt structure, is magnetic.