Diffusional Electron Transport Coupled to Thermodynamically Driven Electron Transfers in Redox-Conductive Multivariate Metal-Organic Frameworks

The development of redox-conductive metal-organic frameworks (MOFs) and the fundamental understanding of charge propagation through these materials are central to their applications in energy storage, electronics, and catalysis. To answer some unresolved questions about diffusional electron hopping transport and redox conductivity, mixed-linker MOFs were constructed from two statistically distributed redox-active linkers, pyromellitic diimide bis-pyrazolate (PMDI) and naphthalene diimide bis-pyrazolate (NDI), and grown as crystalline thin films on conductive fluorine-doped tin oxide (FTO). Owing to the distinct redox properties of the linkers, four well-separated and reversible redox events are resolved by cyclic voltammetry, and the mixed-linker MOFs can exist in five discrete redox states. Each state is characterized by a unique spectroscopic signature, and the interconversions between the states can be followed spectroscopically under operando conditions. With the help of pulsed step-potential spectrochronoamperometry, two modes of electron propagation through the mixed-linker MOF are identified: diffusional electron hopping transport between linkers of the same type and a second channel that arises from thermodynamically driven electron transfers between linkers of different types. Corresponding to the four redox events of the mixed-linker MOFs, four distinct bell-shaped redox conductivity profiles are observed at a steady state. The magnitude of the maximum redox conductivity is evidenced to be dependent on the distance between redox hopping sites, analogous to the situation for apparent electron diffusion coefficients, Deapp, that are obtained in transient experiments. The design of mixed-linker redox-conductive MOFs and detailed studies of their charge transport properties present new opportunities for future applications of MOFs, in particular, within electrocatalysis.

Teaching Medical Students Rapid Ultrasound for shock and hypotension (RUSH): learning outcomes and clinical performance in a proof-of-concept study

BACKGROUND

Point-of-care ultrasound (POCUS) is a critical diagnostic tool in various medical settings, yet its instruction in medical education is inconsistent. The Rapid Ultrasound for Shock and Hypotension (RUSH) protocol is a comprehensive diagnostic tool, but its complexity poses challenges for teaching and learning. This study evaluates the effectiveness of a single-day training in RUSH for medical students by assessing their performance in clinical scenarios.

METHODS

In this prospective single-center observational proof-of-concept study, 16 medical students from Saarland University Medical Center underwent a single-day training in RUSH, followed by evaluations in clinical settings and on a high-fidelity simulator. Performance was assessed using a standardized scoring tool and time to complete the RUSH exam. Knowledge gain was measured with pre- and post-training written exams, and diagnostic performance was evaluated with an objective structured clinical examination (OSCE).

RESULTS

Students demonstrated high performance in RUSH exam views across patients (median performance: 85-87%) and improved scanning times, although not statistically significant. They performed better on simulators than on live patients. Written exam scores significantly improved post-training, suggesting a gain in theoretical knowledge. However, more than a third of students could not complete the RUSH exam within five minutes on live patients.

CONCLUSIONS

Single-day RUSH training improved medical students' theoretical knowledge and simulator performance but translating these skills to clinical settings proved challenging. The findings suggest that while short-term training can be beneficial, it may not suffice for clinical proficiency. This study underscores the need for structured and possibly longitudinal training programs to ensure skill retention and clinical applicability.

Temporary extracorporeal life support: single-centre experience with a new concept

OBJECTIVES

The combination of veno-arterial extracorporeal membrane oxygenation with a micro-axial flow pump (ECMELLA) is increasingly used for cardiogenic shock (CS) therapy. We report our experience with a novel single-artery access ECMELLA setup with either femoral (2.0) or jugular venous cannulation (2.1), respectively.

METHODS

Data from 67 consecutive CS patients treated with ECMELLA 2.0 (n = 56) and 2.1 (n = 11) from December 2020 and December 2022 in a tertiary cardiac center were retrospectively analyzed.

RESULTS

The mean age was 60.7 ± 11 years, 56 patients (84%) were male. CS aetiology was acute on chronic heart failure (n = 35, 52%), myocardial infarction (n = 13, 19.5%), postcardiotomy syndrome (n = 16, 24%) and myocarditis (n = 3, 4.5%). Preoperatively 31 patients (46%) were resuscitated, 53 (79%) were on a ventilator and 60 (90%) were on inotropic support. The median vasoactive inotropic score was 32, and the mean arterial lactate was 8.1 mmol/l. In 39 patients (58%), veno-arterial extracorporeal membrane oxygenation was explanted after a median ECMELLA support of 4 days. Myocardial recovery was achieved in 18 patients (27%), transition to a durable left ventricular assist device in 16 (24%). Thirty-three patients (n = 33; 49%) died on support (25 on ECMELLA and 8 on Impella after de-escalation), 9 (13%) of whom were palliated. Axillary access site bleeding occurred in 9 patients (13.5%), upper limb ischaemia requiring surgical revision in 3 (4.5%). Axillary site infection occurred in 6 cases (9%), and perioperative stroke in 10 (15%; 6 hemorrhagic, 4 thromboembolic).

CONCLUSIONS

ECMELLA 2.0/2.1 is a feasible and effective therapy for severe CS. The single-artery cannulation technique is associated with a relatively low rate of access-related complications.

Analysis of single nuclear chromatin accessibility reveals unique myeloid populations in human pancreatic ductal adenocarcinoma

BACKGROUND

A better understanding of the pancreatic ductal adenocarcinoma (PDAC) immune microenvironment is critical to developing new treatments and improving outcomes. Myeloid cells are of particular importance for PDAC progression; however, the presence of heterogenous subsets with different ontogeny and impact, along with some fluidity between them, (infiltrating monocytes vs. tissue-resident macrophages; M1 vs. M2) makes characterisation of myeloid populations challenging. Recent advances in single cell sequencing technology provide tools for characterisation of immune cell infiltrates, and open chromatin provides source and function data for myeloid cells to assist in more comprehensive characterisation. Thus, we explore single nuclear assay for transposase accessible chromatin (ATAC) sequencing (snATAC-Seq), a method to analyse open gene promoters and transcription factor binding, as an important means for discerning the myeloid composition in human PDAC tumours.

METHODS

Frozen pancreatic tissues (benign or PDAC) were prepared for snATAC-Seq using 10× Chromium technology. Signac was used for preliminary analysis, clustering and differentially accessible chromatin region identification. The genes annotated in promoter regions were used for Gene Ontology (GO) enrichment and cell type annotation. Gene signatures were used for survival analysis with The Cancer Genome Atlas (TCGA)-pancreatic adenocarcinoma (PAAD) dataset.

RESULTS

Myeloid cell transcription factor activities were higher in tumour than benign pancreatic samples, enabling us to further stratify tumour myeloid populations. Subcluster analysis revealed eight distinct myeloid populations. GO enrichment demonstrated unique functions for myeloid populations, including interleukin-1b signalling (recruited monocytes) and intracellular protein transport (dendritic cells). The identified gene signature for dendritic cells influenced survival (hazard ratio = .63, p = .03) in the TCGA-PAAD dataset, which was unique to PDAC.

CONCLUSIONS

These data suggest snATAC-Seq as a method for analysis of frozen human pancreatic tissues to distinguish myeloid populations. An improved understanding of myeloid cell heterogeneity and function is important for developing new treatment targets in PDAC.

Non-Neuraxial Chest and Abdominal Wall Regional Anesthesia for Intensive Care Physicians-A Narrative Review

Multi-modal analgesic strategies, including regional anesthesia techniques, have been shown to contribute to a reduction in the use of opioids and associated side effects in the perioperative setting. Consequently, those so-called multi-modal approaches are recommended and have become the state of the art in perioperative medicine. In the majority of intensive care units (ICUs), however, mono-modal opioid-based analgesic strategies are still the standard of care. The evidence guiding the application of regional anesthesia in the ICU is scarce because possible complications, especially associated with neuraxial regional anesthesia techniques, are often feared in critically ill patients. However, chest and abdominal wall analgesia in particular is often insufficiently treated by opioid-based analgesic regimes. This review summarizes the available evidence and gives recommendations for peripheral regional analgesia approaches as valuable complements in the repertoire of intensive care physicians' analgesic portfolios.

TimeTeller: A tool to probe the circadian clock as a multigene dynamical system

Recent studies have established that the circadian clock influences onset, progression and therapeutic outcomes in a number of diseases including cancer and heart diseases. Therefore, there is a need for tools to measure the functional state of the molecular circadian clock and its downstream targets in patients. Moreover, the clock is a multi-dimensional stochastic oscillator and there are few tools for analysing it as a noisy multigene dynamical system. In this paper we consider the methodology behind TimeTeller, a machine learning tool that analyses the clock as a noisy multigene dynamical system and aims to estimate circadian clock function from a single transcriptome by modelling the multi-dimensional state of the clock. We demonstrate its potential for clock systems assessment by applying it to mouse, baboon and human microarray and RNA-seq data and show how to visualise and quantify the global structure of the clock, quantitatively stratify individual transcriptomic samples by clock dysfunction and globally compare clocks across individuals, conditions and tissues thus highlighting its potential relevance for advancing circadian medicine.

Dynamic chromatin remodeling in cycling human endometrium at single-cell level

Estrogen-dependent proliferation followed by progesterone-dependent differentiation of the endometrium culminates in a short implantation window. We performed single-cell assay for transposase-accessible chromatin with sequencing on endometrial samples obtained across the menstrual cycle to investigate the regulation of temporal gene networks that control embryo implantation. We identify uniquely accessible chromatin regions in all major cellular constituents of the endometrium, delineate temporal patterns of coordinated chromatin remodeling in epithelial and stromal cells, and gain mechanistic insights into the emergence of a receptive state through integrated analysis of enriched transcription factor (TF) binding sites in dynamic chromatin regions, chromatin immunoprecipitation sequencing analyses, and gene expression data. We demonstrate that the implantation window coincides with pervasive cooption of transposable elements (TEs) into the regulatory chromatin landscape of decidualizing cells and expression of TE-derived transcripts in a spatially defined manner. Our data constitute a comprehensive map of the chromatin changes that control TF activities in a cycling endometrium at cellular resolution.

Electrochromism in Isoreticular Metal-Organic Framework Thin Films with Record High Coloration Efficiency

The power of isoreticular chemistry has been widely exploited to engineer metal-organic frameworks (MOFs) with fascinating molecular sieving and storage properties but is underexplored for designing MOFs with tunable optoelectronic properties. Herein, three dipyrazole-terminated XDIs (X = PM (pyromellitic), N (naphthalene), or P (perylene); DI = diimide) with different lengths and electronic properties are prepared and employed as linkers for the construction of an isoreticular series of Zn-XDI MOFs with distinct electrochromism. The MOFs are grown on fluorine-doped tin oxide (FTO) as high-quality crystalline thin films and characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Due to the constituting electronically isolated XDI linkers, each member of the isoreticular thin film series exhibits two reversible one-electron redox events, each at a distinct electrochemical potential. The orientation of the MOFs as thin films as well as their isoreticular nature results in identical cation-coupled electron hopping transport rates in all three materials, as demonstrated by comparable apparent electron diffusion coefficients, Deapp. Upon electrochemical reduction to either the [XDI]•- or [XDI]2- state, each MOF undergoes characteristic changes in its optical properties as a function of linker length and redox state of the linker. Operando spectroelectrochemistry measurements reveal that Zn-PDI@FTO (PDI = perylene diimide) thin films exhibit a record high coloration efficiency of 941 cm2 C-1 at 746 nm, which is attributed to the maximized Faradaic transformations at each electronically isolated PDI unit. The electrochromic response of the thin film is retained to more than 99% over 100 reduction-oxidation cycles, demonstrating the applicability of the presented materials.

Mechanistic Insights and Synthetic Explorations of the Photoredox-Catalyzed Activation of Halophosphines

The light-driven activation of halophosphines R2PX (R = alkyl- or aryl, X = Cl, Br) by an IrIII-based photocatalyst is described. It is shown that initially formed secondary phosphines R2PH react readily with the remaining R2PX in a parent-child reaction to form diphosphines R2P-PR2. Aryl-containing diphosphines can be further reduced to secondary phosphines RAr2PH under identical photoredox conditions. Dihalophosphines RPX2 are also activated by the photoredox protocol, giving rise to unusual 3-, 4-, and 5-membered cyclophosphines. Transient absorption studies show that the excited state of the Ir photocatalyst is reductively quenched by the DIPEA (N,N-di-iso-propylethylamine) electron donor. Electron transfer to R2PX is however unexpectedly slow and cannot compete with recombination with the oxidized donor DIPEA•+. As DIPEA is not a perfectly reversible donor, a small proportion of the total IrII population escapes recombination, providing the reductant for the observed transformations.

Temporary Mechanical Circulatory Support in Cardiogenic Shock Patients after Cardiac Procedures: Selection Algorithm and Weaning Strategies

Mechanical circulatory support has proven effective in managing postcardiotomy cardiogenic shock by stabilizing patients' hemodynamics and ensuring adequate organ perfusion. Among the available device modalities, the combination of extracorporeal life support and a microaxial flow pump for left ventricular unloading has emerged as a valuable tool in the surgical armamentarium. In this publication, we provide recommendations for the application and weaning of temporary mechanical circulatory support in cardiogenic shock patients, derived from a consensus among leading cardiac centers in German-speaking countries.

Experimental manifestation of redox-conductivity in metal-organic frameworks and its implication for semiconductor/insulator switching

Electric conductivity in metal-organic frameworks (MOFs) follows either a band-like or a redox-hopping charge transport mechanism. While conductivity by the band-like mechanism is theoretically and experimentally well established, the field has struggled to experimentally demonstrate redox conductivity that is promoted by the electron hopping mechanism. Such redox conductivity is predicted to maximize at the mid-point potential of the redox-active units in the MOF, and decline rapidly when deviating from this situation. Herein, we present direct experimental evidence for redox conductivity in fluorine-doped tin oxide surface-grown thin films of Zn(pyrazol-NDI) (pyrazol-NDI = 1,4-bis[(3,5-dimethyl)-pyrazol-4-yl]naphthalenediimide). Following Nernstian behavior, the proportion of reduced and oxidized NDI linkers can be adjusted by the applied potential. Through a series of conductivity measurements, it is demonstrated that the MOF exhibits minimal electric resistance at the mid-point potentials of the NDI linker, and conductivity is enhanced by more than 10000-fold compared to that of either the neutral or completely reduced films. The generality of redox conductivity is demonstrated in MOFs with different linkers and secondary building units, and its implication for applications that require switching between insulating and semiconducting regimes is discussed.

Rhizobial nitrogen fixation efficiency shapes endosphere bacterial communities and Medicago truncatula host growth

BACKGROUND

Despite the knowledge that the soil-plant-microbiome nexus is shaped by interactions amongst its members, very little is known about how individual symbioses regulate this shaping. Even less is known about how the agriculturally important symbiosis of nitrogen-fixing rhizobia with legumes is impacted according to soil type, yet this knowledge is crucial if we are to harness or improve it. We asked how the plant, soil and microbiome are modulated by symbiosis between the model legume Medicago truncatula and different strains of Sinorhizobium meliloti or Sinorhizobium medicae whose nitrogen-fixing efficiency varies, in three distinct soil types that differ in nutrient fertility, to examine the role of the soil environment upon the plant-microbe interaction during nodulation.

RESULTS

The outcome of symbiosis results in installment of a potentially beneficial microbiome that leads to increased nutrient uptake that is not simply proportional to soil nutrient abundance. A number of soil edaphic factors including Zn and Mo, and not just the classical N/P/K nutrients, group with microbial community changes, and alterations in the microbiome can be seen across different soil fertility types. Root endosphere emerged as the plant microhabitat more affected by this rhizobial efficiency-driven community reshaping, manifested by the accumulation of members of the phylum Actinobacteria. The plant in turn plays an active role in regulating its root community, including sanctioning low nitrogen efficiency rhizobial strains, leading to nodule senescence in particular plant-soil-rhizobia strain combinations.

CONCLUSIONS

The microbiome-soil-rhizobial dynamic strongly influences plant nutrient uptake and growth, with the endosphere and rhizosphere shaped differentially according to plant-rhizobial interactions with strains that vary in nitrogen-fixing efficiency levels. These results open up the possibility to select inoculation partners best suited for plant, soil type and microbial community. Video Abstract.

Severe pulmonary valve insufficiency caused by transjugular cannulation of pulmonary artery for right ventricular assist device: diagnosis and surgical solution-a case report

Implantation of a temporary percutaneous right ventricular assist device (RVAD) in patients with right heart failure after left ventricular assist device (LVAD) implantation is an established technique that may cause complications. We present a 60-year-old male patient who underwent urgent LVAD implantation. On the second postoperative day the patient developed acute right heart failure. We implanted a temporary percutaneous RVAD with two cannulas via the right internal jugular vein and the right femoral vein. Transesophageal echocardiography revealed severe pulmonary insufficiency. After performing re-sternotomy we anastomosed a prosthetic graft to the pulmonary trunk (PT), performed subxiphoid tunneling of the graft and replaced the transjugular outflow cannula. The pulmonary regurgitation caused by the percutaneous transvalvular cannula disappeared. In such case a direct anastomosis to the PT is the solution.

Lineage skewing and genome instability underlie marrow failure in a zebrafish model of GATA2 deficiency

Inherited bone marrow failure associated with heterozygous mutations in GATA2 predisposes toward hematological malignancies, but the mechanisms remain poorly understood. Here, we investigate the mechanistic basis of marrow failure in a zebrafish model of GATA2 deficiency. Single-cell transcriptomics and chromatin accessibility assays reveal that loss of gata2a leads to skewing toward the erythroid lineage at the expense of myeloid cells, associated with loss of cebpa expression and decreased PU.1 and CEBPA transcription factor accessibility in hematopoietic stem and progenitor cells (HSPCs). Furthermore, gata2a mutants show impaired expression of npm1a, the zebrafish NPM1 ortholog. Progressive loss of npm1a in HSPCs is associated with elevated levels of DNA damage in gata2a mutants. Thus, Gata2a maintains myeloid lineage priming through cebpa and protects against genome instability and marrow failure by maintaining expression of npm1a. Our results establish a potential mechanism underlying bone marrow failure in GATA2 deficiency.

Implementation of the Kidney Disease Improving Global Outcomes guidelines for the prevention of acute kidney injury after cardiac surgery: An international cohort survey

BACKGROUND

Increasing evidence from randomised controlled trials supports the implementation of a six-measure care bundle proposed by the Kidney Disease Improving Global Outcomes (KDIGO) guidelines in patients at high risk for acute kidney injury (AKI) to reduce its incidence after cardiac surgery.

OBJECTIVE

To assess compliance with the KDIGO bundle in clinical practice.

DESIGN

Prospective observational multinational study.

SETTING

Six international tertiary care centres, from February 2021 to November 2021.

PATIENTS

Five hundred and thirty-seven consecutive patients undergoing cardiac surgery during a 1-month observational period.

INTERVENTIONS

All patients were assessed for the postoperative implementation of the following measures: avoidance of nephrotoxic medication and radiocontrast agents whenever possible, strict glycaemic control, close monitoring of renal function, optimisation of haemodynamic and volume status and functional monitoring of haemodynamic status.

MAIN OUTCOME MEASURES

The primary endpoint was the proportion of patients receiving fully compliant care. Secondary outcomes were occurrence of AKI and major adverse kidney event rate at day 30.

RESULTS

The full care bundle was applied to 0.4% of patients. There was avoidance of nephrotoxic drugs in 15.6%, radiocontrast agents in 95.3% and hyperglycaemia in 39.6%. Close monitoring of urine output and serum creatinine was achieved in 6.3%, 57.4% underwent optimisation of volume and haemodynamic status, and 43.9% received functional haemodynamic monitoring. 27.2% developed AKI within 72 h after surgery. The average number of implemented measures was 2.6 ± 1.0 and did not differ between AKI or non-AKI patients ( P  = 0.854).

CONCLUSION

Adherence with the KDIGO bundle was very low in cardiac surgery patients. Initiatives to improve guideline compliance might provide a strategy to mitigate the burden of AKI.

TRIAL REGISTRATION

www.drks.de DRKS00024204.

Molecular Catalysis of Energy Relevance in Metal-Organic Frameworks: From Higher Coordination Sphere to System Effects

The modularity and synthetic flexibility of metal-organic frameworks (MOFs) have provoked analogies with enzymes, and even the term MOFzymes has been coined. In this review, we focus on molecular catalysis of energy relevance in MOFs, more specifically water oxidation, oxygen and carbon dioxide reduction, as well as hydrogen evolution in context of the MOF-enzyme analogy. Similar to enzymes, catalyst encapsulation in MOFs leads to structural stabilization under turnover conditions, while catalyst motifs that are synthetically out of reach in a homogeneous solution phase may be attainable as secondary building units in MOFs. Exploring the unique synthetic possibilities in MOFs, specific groups in the second and third coordination sphere around the catalytic active site have been incorporated to facilitate catalysis. A key difference between enzymes and MOFs is the fact that active site concentrations in the latter are often considerably higher, leading to charge and mass transport limitations in MOFs that are more severe than those in enzymes. High catalyst concentrations also put a limit on the distance between catalysts, and thus the available space for higher coordination sphere engineering. As transport is important for MOF-borne catalysis, a system perspective is chosen to highlight concepts that address the issue. A detailed section on transport and light-driven reactivity sets the stage for a concise review of the currently available literature on utilizing principles from Nature and system design for the preparation of catalytic MOF-based materials.

[The Role of the Percutaneous Impella Pump in Anesthesia and Intensive Care]

The use of temporary mechanical circulatory support (tMCS) devices and in particular the increasing use of the Impella device family has gained significant interest over the last two decades. Nowadays, its use plays a well-established key role in both the treatment of cardiogenic shock, and as a preventive and protective therapeutic option during high-risk procedures in both cardiac surgery and cardiology, such as complex percutaneous interventions (protected PCI). Thus, it is not surprising that the Impella device is more and more present in the perioperative setting and especially in patients on intensive care units. Despite the numerous advantages such as cardiac resting and hemodynamic stabilization, potential adverse events exist, which may lead to severe, but preventable complications, so that adequate education, early recognition of such events and a subsequent adequate management are crucial in patients with tMCS. This article provides an overview especially for anesthesiologists and intensivists focusing on technical basics, indications and contraindications for its use with special focus on the intra- and postoperative management. Furthermore, troubleshooting for most common complications for patients on Impella support is provided.

[Perioperative hyperoxia-More harmful than beneficial?]

BACKGROUND

The ideal perioperative oxygen concentration is controversial and study results are inconsistent.

OBJECTIVE

Current knowledge on the beneficial and adverse effects of perioperative hyperoxia.

MATERIAL AND METHODS

Narrative review RESULTS: Perioperative hyperoxia is unlikely to increase the incidence of atelectasis, pulmonary or cardiovascular complications or mortality. Few and small potential beneficial effects, such as reduction of surgical wound infections or postoperative nausea and vomiting have been demonstrated. According to the current state of evidence, it is recommended to avoid perioperative hyperoxia and to aim for normoxia instead.

Lateral Electron and Hole Hopping between Dyes on Mesoporous ZrO2: Unexpected Influence of Solvents with a Low Dielectric Constant

Lateral intermolecular charge transfer between photosensitizers on metal oxide substrates is important for the understanding on the overall working principles of dye-sensitized systems. Such studies usually concentrate on either hole or electron transfer separately and are conducted in solvents with a high dielectric constant (ε_s) that are known, however, to show a drastic decrease of the local dielectric constant close to the metal oxide surface. In the present study, both hole and electron hopping between organic donor-acceptor photosensitizers was experimentally investigated on PB6 dye-sensitized mesoporous ZrO₂ films. The donor (close to the surface) and acceptor (away from surface) subunit of the PB6 dye were observed to be involved in hole and electron hopping, respectively. Hole and electron transfer kinetics were found to differ remarkably in high-ε_s solvents, but similar in solvents with ε_s < 12. This finding indicates that low-ε_s solvents maintain similar local dielectric constant values close to, and further away from, the semiconductor surface, which is different from the previously observed behavior of high dielectric constant solvents at a metal oxide interface.

Precursors for the Development of π-Conjugated Low-Coordinate Phosphorus Compounds

The synthesis of a novel monomeric precursor and its butadiyne-bridged dimeric form for the preparation of novel π-conjugated organophosphorus compounds is presented. The precursors are synthesized from commercially available starting materials, and based on a Dmp (2,6-dimesitylphenyl) group for kinetic stabilization of the P-functionality, a bromo substituent for the introduction of the phosphorus center, and an acetylene unit at the para position of the Dmp moiety. Such acetylenic units are synthetically versatile, and can be explored for the construction of larger phosphorus-containing π-conjugates. The precursors are utilized to prepare Dmp-stabilized C,C-dibromophosphaalkenes, and butadiyne-bridged dimeric species thereof. The effect of the low-coordinate phosphorus centers and the extent of π-conjugation on the spectroscopic and electronic properties is evaluated by NMR and UV/Vis spectroscopy, as well as cyclic voltammetry. In addition to the phosphaalkenes, the successful syntheses of two new diphosphenes are presented, indicating a broad applicability of the precursor.

Alternating Metal-Ligand Coordination Improves Electrocatalytic CO2 Reduction by a Mononuclear Ru Catalyst

Molecular electrocatalysts for CO₂ -to-CO conversion often operate at large overpotentials, due to the large barrier for C-O bond cleavage. Illustrated with ruthenium polypyridyl catalysts, we herein propose a mechanistic route that involves one metal center that acts as both Lewis base and Lewis acid at different stages of the catalytic cycle, by density functional theory in corroboration with experimental FTIR. The nucleophilic character of the Ru center manifests itself in the initial attack on CO₂ to form [Ru-CO₂ ]⁰ , while its electrophilic character allows for the formation of a 5-membered metallacyclic intermediate, [Ru-CO₂ CO₂ ]^0,c , by addition of a second CO₂ molecule and intramolecular cyclization. The calculated activation barrier for C-O bond cleavage via the metallacycle is decreased by 34.9 kcal mol^-1 as compared to the non-cyclic adduct in the two electron reduced state of complex 1. Such metallacyclic intermediates in electrocatalytic CO₂ reduction offer a new design feature that can be implemented consciously in future catalyst designs.

Highly Sensitive and Specific Detection of Bladder Cancer via Targeted Ultra-deep Sequencing of Urinary DNA

BACKGROUND

There is an unmet need for an accurate, validated, noninvasive test for diagnosing and monitoring bladder cancer (BC). Detection of BC-associated mutations in urinary DNA via targeted deep sequencing could meet this need.

OBJECTIVE

To test the ability of mutational analysis of urinary DNA to noninvasively detect BC within the context of haematuria investigations and non-muscle-invasive BC (NMIBC) surveillance.

DESIGN, SETTING, AND PARTICIPANTS

Capture-based ultra-deep sequencing was performed for 443 somatic mutations in 23 genes in 591 urine cell-pellet DNAs from haematuria clinic patients and 293 from NMIBC surveillance patients. Variant calling was optimised to minimise false positives using urine samples from 162 haematuria clinic patients without BC.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

The sensitivity and specificity for BC diagnosis were determined.

RESULTS AND LIMITATIONS

Mutational analysis of urinary DNA detected 144 of the 165 haematuria patients diagnosed with incident BC from two independent cohorts, yielding overall sensitivity of 87.3% (95% confidence interval [CI] 81.2-92.0%) at specificity of 84.8% (95% CI 79.9-89.0%). The sensitivity was 97.4% for grade 3, 86.5% for grade 2, and 70.8% for grade 1 BC. Among NMIBC surveillance patients, 25 out of 29 recurrent BCs were detected, yielding sensitivity of 86.2% (95% CI 70.8-97.7%) at specificity of 62.5% (95% CI 56.1-68.0%); a positive urine mutation test in the absence of clinically detectable disease was associated with a 2.6-fold increase in the risk of future recurrence. The low number of recurrences in the NMIBC surveillance cohort and the lower sensitivity for detecting grade 1 pTa BC are limitations.

CONCLUSIONS

Detection of mutations in a small panel of BC-associated genes could facilitate noninvasive BC testing and expedite haematuria investigations. Following further validation, the test could also play a role in NMIBC surveillance.

PATIENT SUMMARY

Identification of alterations in genes that are frequently mutated in bladder cancer appears to be a promising strategy for detecting disease from urine samples and reducing reliance on examination of the bladder via a telescopic camera inserted through the urethra.

Complications related to the access site after transaxillary implantation of a microaxial left ventricular assist device

BACKGROUND

Impella 5.0 and 5.5 (summarized as Impella 5+) are microaxial, catheter-based left ventricular assist devices (LVAD) that are implanted via a vascular graft sutured to the axillary artery and provide blood flow of up to 5.5 liter/min. This study aims to investigate the incidence of long-term complications following circulatory support with Impella 5+.

METHODS

A single-center retrospective analysis of 203 consecutive adult patients treated between January 2017 and September 2021 with a surgically implanted Impella 5.0 or 5.5 via a vascular graft sutured to the axillary artery.

RESULTS

The median Impella support duration was 8 days. Of 203 patients, 78 (38.4%) died while on temporary mechanical circulatory support. Fifty-five (27.1%) were successfully weaned from Impella 5+ and 70 (34.5%) were bridged to a durable LVAD with a median follow-up time of 232 (IQR 68.5, 597) days after Impella 5+ explantation. In 119 of these patients, the Impella was explanted and the vascular graft was shortened, ligated, and pushed under the pectoralis muscle; in 6 patients early graft infection prompted complete graft removal during explantation. In addition, 13 patients (10.9%) developed a late-onset graft infection after a median of 86 days, requiring complete (n = 10) or partial (n = 2) explantation of the retained graft. In 1 patient, the graft infection was successfully treated by conservative therapy. Our analysis identified no specific risk factors for graft infections. Of the 203 patients, 5 (2.5%) developed a brachial plexus injury resulting in neurological dysfunction.

CONCLUSIONS

In 10.9% of patients, retaining the vascular graft was complicated by a late graft infection. Complete explantation of the graft prosthesis may decrease the infection rate, but may in turn increase the risk of brachial plexus injury. On the other hand, this method offers the possibility of bedside explantation.

Epigenetic priming of immune/inflammatory pathways activation and abnormal activity of cell cycle pathway in a perinatal model of white matter injury

Prenatal inflammatory insults accompany prematurity and provoke diffuse white matter injury (DWMI), which is associated with increased risk of neurodevelopmental pathologies, including autism spectrum disorders. DWMI results from maturation arrest of oligodendrocyte precursor cells (OPCs), a process that is poorly understood. Here, by using a validated mouse model of OPC maturation blockade, we provide the genome-wide ID card of the effects of neuroinflammation on OPCs that reveals the architecture of global cell fate issues underlining their maturation blockade. First, we find that, in OPCs, neuroinflammation takes advantage of a primed epigenomic landscape and induces abnormal overexpression of genes of the immune/inflammatory pathways: these genes strikingly exhibit accessible chromatin conformation in uninflamed OPCs, which correlates with their developmental, stage-dependent expression, along their normal maturation trajectory, as well as their abnormal upregulation upon neuroinflammation. Consistently, we observe the positioning on DNA of key transcription factors of the immune/inflammatory pathways (IRFs, NFkB), in both unstressed and inflamed OPCs. Second, we show that, in addition to the general perturbation of the myelination program, neuroinflammation counteracts the physiological downregulation of the cell cycle pathway in maturing OPCs. Neuroinflammation therefore perturbs cell identity in maturing OPCs, in a global manner. Moreover, based on our unraveling of the activity of genes of the immune/inflammatory pathways in prenatal uninflamed OPCs, the mere suppression of these proinflammatory mediators, as currently proposed in the field, may not be considered as a valid neurotherapeutic strategy.

HeartWare to HeartMate 3 left ventricular assist device exchange via a left lateral thoracotomy

A continuous-flow left ventricular assist device implant is a well-established therapy for patients with end-stage heart failure. Currently, the HeartMate 3 device is the only commercially available durable left ventricular assist device. Therefore, patients on HeartWare HVAD support who require a pump exchange must have a HeartMate 3 implanted.

Gold nanoparticle-based supramolecular approach for dye-sensitized H2-evolving photocathodes

Solar conversion of water into the storable energy carrier H₂ can be achieved through photoelectrochemical water splitting using light adsorbing anodes and cathodes bearing O₂ and H₂ evolving catalysts, respectively. Herein a novel photocathode nanohybrid system is reported. This photocathode consists of a dye-sensitized p-type nickel oxide (NiO) with a perylene-based chromophore (PCA) and a tetra-adamantane modified cobaloxime reduction catalyst (Co) that photo-reduces aqueous protons to H₂. An original supramolecular approach was employed, using β-cyclodextrin functionalized gold nanoparticles (β-CD-AuNPs) to link the alkane chain of the PCA dye to the adamantane moieties of the cobaloxime catalyst (Co). This new architecture was investigated by photoelectrochemical measurements and via femtosecond-transient absorption spectroscopy. The results show that irradiation of the complete NiO|PCA|β-CD-AuNPs|Co electrode leads to ultrafast hole injection into NiO (π = 3 ps) from the excited dye, followed by rapid reduction of the catalyst, and finally H₂ evolution.

P-436 EndoTime: Non-categorical timing estimates for luteal endometrium

Study question

Can expression measurements of a small panel of genes be used to develop a continuous, non-categorical model for the improvement of endometrial biopsy timing accuracy?

Summary answer

Measuring expression levels of six genes (IL2RB, IGFBP1, CXCL14, DPP4, GPX3, and SLC15A2) is sufficient to obtain and assess substantially more accurate timing estimates.

What is known already

Commercially available endometrial timing approaches based on gene expression require much larger gene sets and use a categorical approach that classifies samples as pre-receptive, receptive, or post-receptive.

Study design, size, duration

Gene expression was measured by RT-qPCR in different sample sets, comprising a total of 664 endometrial biopsies obtained 4 to 12 days after a self-reported positive home ovulation test. A further 36 endometrial samples were profiled by RT-qPCR as well as RNA-sequencing.

Participants/materials, setting, methods

A computational procedure, named ‘EndoTime’, was established that models the temporal profile of each gene and estimates the timing of each sample. Iterating these steps, temporal profiles are gradually refined as sample timings are being updated, and confidence in timing estimates is increased. After convergence, the method reports updated timing estimates for each sample while preserving the overall distribution of time points.

Main results and the role of chance

The Wilcoxon rank-sum test was used to confirm that ordering samples by EndoTime estimates yields sharper temporal expression profiles for held-out genes (not used when determining sample timings) than ordering the same expression values by patient-reported times (GPX3 : p &lt; 0.005; CXCL14 : p &lt; 2.7e-6; DPP4 : p &lt; 3.7e-13). Pearson correlation between EndoTime estimates for the same sample set but based on RT-qPCR or RNA-sequencing data showed high degree of congruency between the two (p = 8.6e-10, R-squared = 0.687). Estimated timings did not differ significantly between control subjects and patients with recurrent pregnancy loss or recurrent implantation failure (p &gt; 0.05).

Limitations, reasons for caution

Timing estimates are informed by glandular gene expression and will only represent the temporal state of other endometrial cell types if in synchrony with the epithelium. Additionally, methods that estimate the day of ovulation are still required as these data are essential inputs in our method.

Wider implications of the findings

Our method is the first to assay the temporal state of endometrial samples on a continuous domain, enabling accurate temporal profiling of any gene in luteal phase biopsies for a wide range of research applications and, potentially, clinical use. It is freely available, open-source software including supporting data sets.

Trial registration number

Not applicable

POS0809 CHARACTERIZATION OF RELAPSES IN PATIENTS WITH GIANT CELL ARTERITIS (GCA) PATIENTS- DATA FROM THE REAL-LIFE TREATMENT AND SAFETY (REATS)-GCA COHORT

Background

Giant cell arteritis (GCA) has the tendency to relapse once treatment is tapered or stopped. Such relapses represent a potential threat to GCA patients as they can lead to severe symptoms and organ damage.

Objectives

To assess the frequency and type of relapses in patients with GCA

Methods

The Real-Life Treatment and Safety (REATS)-GCA cohort has been established by extracting the data on clinical presentation, inflammatory markers, imaging, comorbidities, treatments and serious adverse events of GCA patients from 6 specialized centres in Germany. We undertook descriptive and survival analyses (Kaplan-Meier), and compared baseline characteristics of participants with vs. without relapse. Ethical approval for the cohort was obtained.

Results

We included 395 patients with a mean age of 71 years, including 264 (66.8 %) females and 129 (32.7%) males. Diagnosis of GCA was supported by temporal artery ultrasound in 37%, 18F-FDG-PET/CT in 29%, temporal artery biopsy in 14% of patients and by MRI or clinically in the remaining patients. 31% of patients presented with an isolated cranial manifestation and 18% with isolated extracranial manifestations. Most common presenting symptoms were headache (57%), fatigue (55%), weight loss (42%) and polymyalgia (38%) (Table 1). The most common comorbidities at the time of study inclusion were arterial hypertension (68%), followed by osteoporosis (26%). Within a median total follow-up duration of 22.2 (11.7-40.6) months, 97 of the 395 patients relapsed including 15 patients who relapsed more than once. The median (IQR) time to first relapse was 12.5 (7.1-21.8) months. Median relapse-free survival was 7.8 years with a relapse risk of 12% (CI, 9 to 15%) at 1 year and 38% (CI, 30 to 45%) at 5 years (Figure 1). Most common symptoms at relapse were headache (35%), polymyalgia (23%), fatigue (19%) and night sweats (12%) (Table 1). Three patients relapsed with sudden loss of vision. Among the 114 relapses observed, 94 (83%) occurred under prednisolone treatment with a median dose of 7.0 mg/day (IQR 4.0-12.5). 26 (23%) occurred under methotrexate and 14 (12%) under tocilizumab treatment. Comparing the baseline characteristics that were documented in this study, we did not find a statistically significant difference in relapsing versus non-relapsing GCA patients.

Table 1.Symptom at disease onsetN=395 (%)Symptom at relapseN=97 (%)Headache216 (54.7)Headache35 (30.7)Fatigue208 (52.7)Polymyalgia (PMR)23 (20.2)Weight loss159 (40.3)Fatigue19 (16.7)Polymyalgia (PMR)144 (36.5)Vision impairment13 (11.4)Night sweats140 (35.4)Night sweats12 (10.5)Headache in the temple area125 (31.6)Headache in the temple area12 (10.5)Jaw pain121 (30.6)Jaw pain11 (9.6)Vision impairment118 (29.9)Morning stiffness7 (6.1)Morning stiffness89 (22.5)Weight loss7 (6.1)Fever80 (20.3)Claudication upper limb6 (5.3)Swelling temporal arteries77 (19.5)Arthralgia6 (5.3)Vision loss57 (14.4)Claudication lower limb5 (4.4)Scalp tenderness38 (9.6)Vision loss3 (2.6)Claudication upper limb38 (9.6)Arthritis3 (2.6)Claudication lower limb34 (8.6)Scalp tenderness2 (1.8)Arthralgia28 (7.1)Fever2 (1.8)Arthritis3 (0.8)Swelling temporal arteries2 (1.8)Figure 1.

Conclusion

About one fourth of GCA patients relapsed and the overwhelming majority of relapses occurred before patients were able to stop glucocorticoids. The leading symptoms at relapse are headache and fatigue, while loss of vision is rare (0.76%). Baseline characteristics seem to be poorly informative about the risk of relapse, therefore regular monitoring of GCA patients is necessary.

Acknowledgements

This research was financially supported by Roche Pharma Ag and Chugai Pharma Europe Ltd.

Disclosure of Interests

Verena Schönau Speakers bureau: Novartis, Janssen, Grant/research support from: Roche, Chugai, Giulia Corte: None declared, Sebastian Ott: None declared, Koray Tascilar: None declared, Fabian Hartmann: None declared, Bernhard Manger: None declared, Bernhard Hellmich: None declared, Alexander Pfeil: None declared, Peter Oelzner: None declared, Wolfgang A. Schmidt: None declared, Andreas Krause: None declared, Marc Schmalzing: None declared, Matthias Fröhlich: None declared, Michael Gernert: None declared, Nils Venhoff: None declared, Jörg Henes: None declared, Jürgen Rech Speakers bureau: Abbvie, Biogen, BMS, Chugai, GSK, Lilly, MSD; Novartis, Roche, Sanofi, Sobi, UCB,, Consultant of: Biogen, BMS, Chugai, GSK, Lilly, MSD, Novartis, Roche, Sanofi, Sobi, UCB, Grant/research support from: Sobi, Novartis, Georg Schett: None declared

Electrocatalytic water oxidation from a mixed linker MOF based on NU-1000 with an integrated ruthenium-based metallo-linker

A novel tetratopic metallo-linker, [Ru(tda)(py(PhCOOH)₂)₂], 1, (tda = 2,2':6',2''-terpyridine-6,6''-dicarboxylate; py(PhCOOH)₂ = (4,4'-(pyridine-3,5-diyl)dibenzoic acid), that is structurally based on one of the most active molecular water oxidation catalysts has been prepared and fully characterized, including single crystal X-ray diffraction. 1 bears geometric similarities to H₄TBAPy (H₄TBAPy = 4,4',4'',4'''-(pyrene-1,3,6,8-tetrayl)tetrabenzoic acid), i.e. the native linker in NU-1000, which offers the possibility to synthesize NU-1000-Ru mixed linker MOFs solvothermally. Mixed linker MOF formation was demonstrated by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM), and Ru linker incorporation confirmed by FT-IR, energy-dispersive X-ray (EDX) spectroscopy and inductively coupled plasma optical emission spectroscopy (ICP-OES). It was found that the Ru contents in the final mixed linker MOFs correlate with the amount of Ru linker present during solvothermal synthesis, albeit not in a linear fashion. The cyclic voltammograms (CV) of the mixed linker MOFs are largely dominated by TBAPy-based oxidations with features attributed to 1. Interestingly, Ru linkers near the crystal surface are oxidized directly by interfacial hole transfer form the electrode, while those in the crystal interior can be oxidized indirectly from oxidized TBAPy linkers at more anodic potential. Upon repeated scanning, the CVs show the appearance of new waves that arise from irreversible TBAPy oxidation, as well as from the activation of the Ru-based water oxidation catalyst. Of the materials prepared, the one with the highest Ru content, NU-1000-Ru_high, was shown to catalyze the electrochemical oxidation of water to dioxygen. The Faradaic efficiency (FE) of the construct is 37%, due to water oxidation being accompanied by oxidative transformations of the TBAPy linkers. Despite the low FE, NU-1000-Ru_high is still among the best MOF-based water oxidation catalysts, operating by a unique co-linker mediated hole-transport mechanism to supply oxidizing equivalents also to catalysts in the crystal interior.

Plant circadian clock control of Medicago truncatula nodulation via regulation of nodule cysteine-rich peptides

Legumes house nitrogen-fixing endosymbiotic rhizobia in specialized polyploid cells within root nodules, which undergo tightly regulated metabolic activity. By carrying out expression analysis of transcripts over time in Medicago truncatula nodules, we found that the circadian clock enables coordinated control of metabolic and regulatory processes linked to nitrogen fixation. This involves the circadian clock-associated transcription factor LATE ELONGATED HYPOCOTYL (LHY), with lhy mutants being affected in nodulation. Rhythmic transcripts in root nodules include a subset of nodule-specific cysteine-rich peptides (NCRs) that have the LHY-bound conserved evening element in their promoters. Until now, studies have suggested that NCRs act to regulate bacteroid differentiation and keep the rhizobial population in check. However, these conclusions came from the study of a few members of this very large gene family that has complex diversified spatio-temporal expression. We suggest that rhythmic expression of NCRs may be important for temporal coordination of bacterial activity with the rhythms of the plant host, in order to ensure optimal symbiosis.

Microscopic Insights into Cation-Coupled Electron Hopping Transport in a Metal-Organic Framework

Electron transport through metal-organic frameworks by a hopping mechanism between discrete redox active sites is coupled to diffusion-migration of charge-balancing counter cations. Experimentally determined apparent diffusion coefficients, D_e^app, that characterize this form of charge transport thus contain contributions from both processes. While this is well established for MOFs, microscopic descriptions of this process are largely lacking. Herein, we systematically lay out different scenarios for cation-coupled electron transfer processes that are at the heart of charge diffusion through MOFs. Through systematic variations of solvents and electrolyte cations, it is shown that the D_e^app for charge migration through a PIZOF-type MOF, Zr(dcphOH-NDI) that is composed of redox-active naphthalenediimide (NDI) linkers, spans over 2 orders of magnitude. More importantly, however, the microscopic mechanisms for cation-coupled electron propagation are contingent on differing factors depending on the size of the cation and its propensity to engage in ion pairs with reduced linkers, either non-specifically or in defined structural arrangements. Based on computations and in agreement with experimental results, we show that ion pairing generally has an adverse effect on cation transport, thereby slowing down charge transport. In Zr(dcphOH-NDI), however, specific cation-linker interactions can open pathways for concerted cation-coupled electron transfer processes that can outcompete limitations from reduced cation flux.

Properties of Liquid Crystal Injection Mouldings

The suitability of liquid crystal polymers for the injection moulding process was pointed out at the time of their discovery. However, up to now, it has been assumed that the unmodified liquid crystal polymers were less suited to processing by injection moulding due to their distinct anisotropies. The direction of developments in the application of liquid crystal polymers was done mainly in another direction. We, however, have been concerned for more than four years now with this subject [3, 4, 5], even when our practical experiments could not be as comprehensive as we would wish, due to the limited availability of the raw materials. We have also been able to use this time to develop CAE programs which support the constructor in the design of injection moulds, whereby these programs enable the flow process to be simulated and therefore enabling the orientation to be seen at every point in the injection moulded part [6]. This is naturally particularly important for those materials in which the orientation of the molecules plays such a large part for the respective properties, as these are caused by the direction of the flows in the flow process. A changed runner position causes other orientations. More details should therefore be reported about our investigations to date.

Cardiogenic Shock Management and Research: Past, Present, and Future Outlook

Although great strides have been made in the pathophysiological understanding, diagnosis and management of cardiogenic shock (CS), morbidity and mortality in patients presenting with the condition remain high. Acute MI is the commonest cause of CS; consequently, most existing literature concerns MI-associated CS. However, there are many more phenotypes of patients with acute heart failure. Medical treatment and mechanical circulatory support are well-established therapeutic options, but evidence for many current treatment regimens is limited. The issue is further complicated by the fact that implementing adequately powered, randomized controlled trials are challenging for many reasons. In this review, the authors discuss the history, landmark trials, current topics of medical therapy and mechanical circulatory support regimens, and future perspectives of CS management.

OUP accepted manuscript

STUDY QUESTION

Can the accuracy of timing of luteal phase endometrial biopsies based on urinary ovulation testing be improved by measuring the expression of a small number of genes and a continuous, non-categorical modelling approach?

SUMMARY ANSWER

Measuring the expression levels of six genes (IL2RB, IGFBP1, CXCL14, DPP4, GPX3 and SLC15A2) is sufficient to obtain substantially more accurate timing estimates and to assess the reliability of timing estimates for each sample.

WHAT IS KNOWN ALREADY

Commercially available endometrial timing approaches based on gene expression require large gene sets and use a categorical approach that classifies samples as pre-receptive, receptive or post-receptive.

STUDY DESIGN, SIZE, DURATION

Gene expression was measured by RTq-PCR in different sample sets, comprising a total of 664 endometrial biopsies obtained 4–12 days after a self-reported positive home ovulation test. A further 36 endometrial samples were profiled by RTq-PCR as well as RNA-sequencing.

PARTICIPANTS/MATERIALS, SETTING, METHODS

A computational procedure, named ‘EndoTime’, was established that models the temporal profile of each gene and estimates the timing of each sample. Iterating these steps, temporal profiles are gradually refined as sample timings are being updated, and confidence in timing estimates is increased. After convergence, the method reports updated timing estimates for each sample while preserving the overall distribution of time points.

MAIN RESULTS AND THE ROLE OF CHANCE

The Wilcoxon rank-sum test was used to confirm that ordering samples by EndoTime estimates yields sharper temporal expression profiles for held-out genes (not used when determining sample timings) than ordering the same expression values by patient-reported times (GPX3: P < 0.005; CXCL14: P < 2.7e−6; DPP4: P < 3.7e−13). Pearson correlation between EndoTime estimates for the same sample set but based on RTq-PCR or RNA-sequencing data showed a high degree of congruency between the two (P = 8.6e−10, R² = 0.687). Estimated timings did not differ significantly between control subjects and patients with recurrent pregnancy loss or recurrent implantation failure (P > 0.05).

LARGE SCALE DATA

The RTq-PCR data files are available via the GitHub repository for the EndoTime software at https://github.com/AE-Mitchell/EndoTime, as is the code used for pre-processing of RTq-PCR data. The RNA-sequencing data are available on GEO (accession GSE180485).

LIMITATIONS, REASONS FOR CAUTION

Timing estimates are informed by glandular gene expression and will only represent the temporal state of other endometrial cell types if in synchrony with the epithelium. Methods that estimate the day of ovulation are still required as these data are essential inputs in our method. Our approach, in its current iteration, performs batch correction such that larger sample batches impart greater accuracy to timing estimations. In theory, our method requires endometrial samples obtained at different days in the luteal phase. In practice, however, this is not a concern as timings based on urinary ovulation testing are associated with a sufficient level of noise to ensure that a variety of time points will be sampled.

WIDER IMPLICATIONS OF THE FINDINGS

Our method is the first to assay the temporal state of luteal-phase endometrial samples on a continuous domain. It is freely available with fully shared data and open-source software. EndoTime enables accurate temporal profiling of any gene in luteal endometrial samples for a wide range of research applications and, potentially, clinical use.

STUDY FUNDING/COMPETING INTEREST(S)

This study was supported by a Wellcome Trust Investigator Award (Grant/Award Number: 212233/Z/18/Z) and the Tommy's National Miscarriage Research Centre. None of the authors have any competing interests. J.L. was funded by the Biotechnology and Biological Sciences Research Council (UK) through the Midlands Integrative Biology Training Partnership (MIBTP, BB/M01116X/1).

“[2+2] Cycloaddition of Phosphaalkenes as Key Step for the Reductive Coupling of Diaryl Ketones to Tetraaryl Olefins

Procedures for the reductive coupling of carbonyl compounds to alkenes in the literature rely either on a radical coupling strategy, as in the McMurry coupling, or ionic pathways, sometimes catalysed by transition metals, as in more contemporary contributions. Herein, we present the first example of a third strategy that is based on the [2 + 2] cycloaddition of ketone-derived phosphaalkenes. Removal of P-trimethylsilyl groups at the intermediary 1,2-diphosphetane dimer results in its collapse and concomitant release of the tetraaryl-substituted alkene. In fact, the presented strategy is the only alternative to the McMurry coupling in the literature that allows tetraaryl alkene formation from diaryl ketones, with yields as high as 85%. The power of the methodology is illustrated in the reaction of tethered bis-benzophenones which engage in intramolecular reductive carbonyl couplings to form unusual macrocycles without the need for high dilution conditions or templating.

Mechanistically distinct from all other carbonyl-to-alkene conversion methodologies, the [2 + 2] cycloaddition of phosphaalkene intermediates is established as the enabling elementary step in this transformation.

Impact of left ventricular inspection employing cardiopulmonary bypass on outcome after implantation of left ventricular assist device

BACKGROUND

Cardiopulmonary bypass (CPB) during left ventricular assist device (LVAD) implantation provides circulatory support and allows for safe inspection of the left ventricle (LV), whereas circulatory support by veno-arterial extracorporeal life support (va-ECLS) or off-pump implantation may reduce postoperative bleeding and inflammatory response.

METHODS

Retrospective analysis of 616 consecutive adult patients who received an LVAD via median sternotomy between January 1, 2015 and December 31, 2019. All patients undergoing concomitant intracardiac procedures other than closure of persistent foramen ovale or atrial septal defect and redo surgeries were excluded from the analysis. The remaining patients (n = 222) were divided into two groups and 1:1 propensity score-matched regarding preoperative parameters: patients who underwent LVAD implantation with LV inspection employing CPB (CPB group, n = 62) and without LV inspection on va-ECLS or off-pump (non-CPB group, n = 62).

RESULTS

The groups were well balanced with regard to preoperative baseline characteristics (standard difference <0.1). Patients in the CPB group required more blood transfusions (median 2 vs. 0 units, p = 0.031) during surgery and in the first 24 h afterwards. The median intensive care unit stay was longer in the CPB group (18 vs. 11 days, p = 0.021). The CPB group showed an absence of perioperative stroke and a smaller number of events per patient-year for postoperative ischemic stroke (0.02 vs. 0.12, p = 0.003). 30-day survival (87% vs. 87.1%) and 1-year survival (80.3% vs. 74%) were similar in both groups (p = 0.78).

CONCLUSION

Visual LV inspection on CPB may reduce the risk of postoperative ischemic stroke. Despite the negative effects of employing CPB in lieu of other intraoperative strategies, survival was similar in both groups.

The immune landscape of SARS-CoV-2-associated Multisystem Inflammatory Syndrome in Children (MIS-C) from acute disease to recovery

Multisystem inflammatory syndrome in children (MIS-C) is a life-threatening disease occurring several weeks after severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Deep immune profiling showed acute MIS-C patients had highly activated neutrophils, classical monocytes and memory CD8+ T-cells, with increased frequencies of B-cell plasmablasts and double-negative B-cells. Post treatment samples from the same patients, taken during symptom resolution, identified recovery-associated immune features including increased monocyte CD163 levels, emergence of a new population of immature neutrophils and, in some patients, transiently increased plasma arginase. Plasma profiling identified multiple features shared by MIS-C, Kawasaki Disease and COVID-19 and that therapeutic inhibition of IL-6 may be preferable to IL-1 or TNF-α. We identified several potential mechanisms of action for IVIG, the most commonly used drug to treat MIS-C. Finally, we showed systemic complement activation with high plasma C5b-9 levels is common in MIS-C suggesting complement inhibitors could be used to treat the disease.

Elemental Depth Profiling of Intact Metal-Organic Framework Single Crystals by Scanning Nuclear Microprobe

The growing field of MOF–catalyst composites often relies on postsynthetic modifications for the installation of active sites. In the resulting MOFs, the spatial distribution of the inserted catalysts has far-reaching ramifications for the performance of the system and thus needs to be precisely determined. Herein, we report the application of a scanning nuclear microprobe for accurate and nondestructive depth profiling of individual UiO-66 and UiO-67 (UiO = Universitetet i Oslo) single crystals. Initial optimization work using native UiO-66 crystals yielded a microbeam method which avoided beam damage, while subsequent analysis of Zr/Hf mixed-metal UiO-66 crystals demonstrated the potential of the method to obtain high-resolution depth profiles. The microbeam method was further used to analyze the depth distribution of postsynthetically introduced organic moieties, revealing either core–shell or uniform incorporation can be obtained depending on the size of the introduced molecule, as well as the number of carboxylate binding groups. Finally, the spatial distribution of platinum centers that were postsynthetically installed in the bpy binding pockets of UiO-67-bpy (bpy = 5,5′-dicarboxyy-2,2′-bipyridine) was analyzed by microbeam and contextualized. We expect that the method presented herein will be applicable for characterizing a wide variety of MOFs subjected to postsynthetic modifications and provide information crucial for their optimization as functional materials.

Immobilising molecular Ru complexes on a protective ultrathin oxide layer of p-Si electrodes towards photoelectrochemical CO2 reduction

Photoelectrochemical CO2 reduction is a promising approach for renewable fuel generation and to reduce greenhouse gas emissions. Owing to their synthetic tunability, molecular catalysts for the CO2 reduction reaction can give rise to high product selectivity. In this context, a RuII complex [Ru(HO-tpy)(6-mbpy)(NCCH3)]2+ (HO-tpy = 4'-hydroxy-2,2':6',2''-terpyridine; 6-mbpy = 6-methyl-2,2'-bipyridine) was immobilised on a thin SiOx layer of a p-Si electrode that was decorated with a bromide-terminated molecular layer. Following the characterisation of the assembled photocathodes by X-ray photoelectron spectroscopy and ellipsometry, PEC experiments demonstrate electron transfer from the p-Si to the Ru complex through the native oxide layer under illumination and a cathodic bias. A state-of-the-art photovoltage of 570 mV was determined by comparison with an analogous n-type Si assembly. While the photovoltage of the modified photocathode is promising for future photoelectrochemical CO2 reduction and the p-Si/SiOx junction seems to be unchanged during the PEC experiments, a fast desorption of the molecular Ru complex was observed. An in-depth investigation of the cathode degradation by comparison with reference materials highlights the role of the hydroxyl functionality of the Ru complex to ensure its grafting on the substrate. In contrast, no essential role for the bromide function on the Si substrate designed to engage with the hydroxyl group of the Ru complex in an SN2-type reaction could be established.

Photoinduced Fano Resonances between Quantum Confined Nanocrystals and Adsorbed Molecular Catalysts

Interaction of surface adsorbate vibration and intraband electron absorption in nanocrystals has been reported to affect the photophysical properties of both nanocrystals and surface adsorbates and may affect the performance of hybrid photocatalysts composed of semiconductor nanocrystals and molecular catalysts. Here, by combining ultrafast transient visible and IR spectroscopic measurements, we report the observation of Fano resonances between the intraband transition of the photogenerated electrons in CdS and CdSe nanocrystals and CO stretching vibrational modes of adsorbed molecular catalysts, [Fe₂(cbdt)(CO)₆] (FeFe; cbdt = 1-carboxyl-benzene-2,3-dithiolate), a molecular mimic for the active site of FeFe-hydrogenase. The occurrence of Fano resonances is independent of nanocrystal types (rods vs dots) or charge transfer character between the nanocrystal and FeFe, and is likely a general feature of nanocrystal and molecular catalyst hybrid systems. These results provide new insights into the fundamental interactions in these hybrid assemblies for artificial photosynthesis.

[Management of Adult Community-Acquired Pneumonia and Prevention - Update 2021 - Guideline of the German Respiratory Society (DGP), the Paul-Ehrlich-Society for Chemotherapy (PEG), the German Society for Infectious Diseases (DGI), the German Society of Medical Intensive Care and Emergency Medicine (DGIIN), the German Viological Society (DGV), the Competence Network CAPNETZ, the German College of General Practitioneers and Family Physicians (DEGAM), the German Society for Geriatric Medicine (DGG), the German Palliative Society (DGP), the Austrian Society of Pneumology Society (ÖGP), the Austrian Society for Infectious and Tropical Diseases (ÖGIT), the Swiss Respiratory Society (SGP) and the Swiss Society for Infectious Diseases Society (SSI)]

The present guideline provides a new and updated concept of the management of adult patients with community-acquired pneumonia. It replaces the previous guideline dating from 2016.The guideline was worked out and agreed on following the standards of methodology of a S3-guideline. This includes a systematic literature search and grading, a structured discussion of recommendations supported by the literature as well as the declaration and assessment of potential conflicts of interests.The guideline has a focus on specific clinical circumstances, an update on severity assessment, and includes recommendations for an individualized selection of antimicrobial treatment.The recommendations aim at the same time at a structured assessment of risk for adverse outcome as well as an early determination of treatment goals in order to reduce mortality in patients with curative treatment goal and to provide palliation for patients with treatment restrictions.

Mimicking the Electron Transport Chain and Active Site of [FeFe] Hydrogenases in One Metal-Organic Framework: Factors That Influence Charge Transport

[FeFe] hydrogenase (H₂ase) enzymes are effective proton reduction catalysts capable of forming molecular dihydrogen with a high turnover frequency at low overpotential. The active sites of these enzymes are buried within the protein structures, and substrates required for hydrogen evolution (both protons and electrons) are shuttled to the active sites through channels from the protein surface. Metal–organic frameworks (MOFs) provide a unique platform for mimicking such enzymes due to their inherent porosity which permits substrate diffusion and their structural tunability which allows for the incorporation of multiple functional linkers. Herein, we describe the preparation and characterization of a redox-active PCN-700-based MOF (PCN = porous coordination network) that features both a biomimetic model of the [FeFe] H₂ase active site as well as a redox-active linker that acts as an electron mediator, thereby mimicking the function of [4Fe4S] clusters in the enzyme. Rigorous studies on the dual-functionalized MOF by cyclic voltammetry (CV) reveal similarities to the natural system but also important limitations in the MOF-enzyme analogy. Most importantly, and in contrast to the enzyme, restrictions apply to the total concentration of reduced linkers and charge-balancing counter cations that can be accommodated within the MOF. Successive charging of the MOF results in nonideal interactions between linkers and restricted mobility of charge-compensating redox-inactive counterions. Consequently, apparent diffusion coefficients are no longer constant, and expected redox features in the CVs of the materials are absent. Such nonlinear effects may play an important role in MOFs for (electro)catalytic applications.