(Sub-)Picosecond Surface Correlations of Femtosecond Laser Excited Al-Coated Multilayers Observed by Grazing-Incidence X-ray Scattering.

Femtosecond high-intensity laser pulses at intensities surpassing 1014 W/cm2 can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional structures necessitates a thorough understanding of the surface morphology dynamics with nanometer-scale spatial resolution and picosecond-scale temporal resolution. In this study, we show that single XFEL pulses can elucidate structural changes on surfaces induced by laser-generated plasmas using grazing-incidence small-angle X-ray scattering (GISAXS). Using aluminium-coated multilayer samples we distinguish between sub-picosecond (ps) surface morphology dynamics and subsequent multi-ps subsurface density dynamics with nanometer-depth sensitivity. The observed subsurface density dynamics serve to validate advanced simulation models representing matter under extreme conditions. Our findings promise to open new avenues for laser material-nanoprocessing and high-energy-density science.

Photoinduced bidirectional mesophase transition in vesicles containing azobenzene amphiphiles.

The functionality and efficiency of proteins within a biological membrane are highly dependent on both the membrane lipid composition and the physiochemical properties of the solution. Lipid mesophases are directly influenced by changes in temperature, pH, water content or due to individual properties of single lipids such as photoswitchability. In this work, we were able to induce light- and temperature-driven mesophase transitions in a model membrane system containing a mixture of 1,2-dipalmitoyl-phosphatidylcholine phospholipids and azobenzene amphiphiles. We observed reversible and reproducible transitions between the lamellar and Pn3m cubic phase after illuminating the sample for 5 min with light of 365 and 455 nm wavelengths, respectively, to switch between the cis and trans states of the azobenzene N=N double bond. These light-controlled mesophase transitions were found for mixed complexes with up to 20% content of the photosensitive molecule and at temperatures below the gel-to-liquid crystalline phase transition temperature of 33°C. Our results demonstrate the potential to design bespoke model systems to study the response of membrane lipids and proteins upon changes in mesophase without altering the environment and thus provide a possible basis for drug delivery systems.

On the dual behaviour of water in octanol-rich aqueous n-octanol mixtures: an X-ray scattering and computer simulation study.

Aqueous n-octanol (n = 1, 2, 3, and 4) mixtures from the octanol rich side are studied by X-ray scattering and computer simulation, with a focus on structural changes, particularly in what concerns the hydration of the hydroxyl-group aggregated chain-like structures, under the influence of various branching of the alkyl tails. Previous studies have indicated that hydroxyl-group chain-cluster formation is hindered in proportion to the branching number. Here, water mole fractions up to x = 0.2 are examined, i.e. up to the miscibility limit. It is found that water molecules within the hydroxyl-chain domains participate in the chain formations in a different manner for 1-octanol and the branched octanols. The hydration of the octanol hydroxyl chains is confirmed by the shifting of the scattering pre-peak position kPP to smaller values, both from measured and simulated X-ray scattering intensities, which corresponds to an increased size of the clusters. Experimental pre-peak amplitudes are seen to increase with increasing water content for 1-octanol, while this trend is reversed in all branched octanols, with the amplitudes decreasing with the increase of the branching number. Conjecturing that the amplitudes of pre-peaks are related to the density of the corresponding aggregates, these results are interpreted as water breaking large OH hydroxyl chains in 1-octanol, hence increasing the density of aggregates, while enhancing hydroxyl aggregates in branched alcohols by inserting itself into the OH chains. The analysis of the cluster distributions from computer simulations provide more details on the role of water. For cluster sizes smaller than dc = 2π/kPP, water is found to always play the role of a structure enforcer for all n-octanols, while for clusters of size dc water is always a destructor. For cluster sizes larger than dc, the role of water differs from 1-octanol and the branched ones: it acts as a structure maker or breaker in inverse proportion to the hindering of OH hydroxyl chain structures arising from the topology of the alkyl tails (branched or not).

Exploring non-equilibrium processes and spatio-temporal scaling laws in heated egg yolk using coherent X-rays.

The soft-grainy microstructure of cooked egg yolk is the result of a series of out-of-equilibrium processes of its protein-lipid contents; however, it is unclear how egg yolk constituents contribute to these processes to create the desired microstructure. By employing X-ray photon correlation spectroscopy, we investigate the functional contribution of egg yolk constituents: proteins, low-density lipoproteins (LDLs), and yolk-granules to the development of grainy-gel microstructure and microscopic dynamics during cooking. We find that the viscosity of the heated egg yolk is solely determined by the degree of protein gelation, whereas the grainy-gel microstructure is controlled by the extent of LDL aggregation. Overall, protein denaturation-aggregation-gelation and LDL-aggregation follows Arrhenius-type time-temperature superposition (TTS), indicating an identical mechanism with a temperature-dependent reaction rate. However, above 75 °C TTS breaks down and temperature-independent gelation dynamics is observed, demonstrating that the temperature can no longer accelerate certain non-equilibrium processes above a threshold value.

Comparative Studies on the Organogel Formation of a Polyester in Three Different Base Oils by X-ray Analysis, Rheology and Infrared Spectroscopy.

High-performance greases typically consist of a base oil and polyurea as a thickener material. To date, few alternatives to polyureas have been investigated. Polyesters could be one such alternative; however, little is known about the gelation of such polyesters because, unlike polyureas, they cannot form hydrogen bonds between the polymer chains. Here, we present studies on the gel formation of a polyester based thickener poly(hexane dodecanoate) with 1-octanol endgroups in three different base oils, i.e., a mineral oil (Brightstock 150), a synthetic Polyalphaolefin (Spectrasyn 40) and castor oil (85 to 90 wt.% ricinoleic acid triglyceride). Small- and wide-angle X-ray scattering measurements indicate a strong interaction of the polyester with castor oil and an increase in the crystalline fraction, with an increasing polymer amount from 5 to 40 wt.%. Moreover, infrared analysis of the polyester in castor oil showed gel formation at a minimum concentration of 20 wt.%. The strong interaction of the polyester with castor oil compared to the other two base oils led to an increase in the yield point γF as a measure of the mechanical stability of the gel, which was determined to be 5.9% compared to 0.8% and 1.0% in Brightstock and Spectrasyn, respectively.

Hybrid Heterostructures of a Spin Crossover Coordination Polymer on MoS2 : Elucidating the Role of the 2D Substrate.

Controlling the deposition of spin-crossover (SCO) materials constitutes a crucial step for the integration of these bistable molecular systems in electronic devices. Moreover, the influence of functional surfaces, such as 2D materials, can be determinant on the properties of the deposited SCO film. In this work, ultrathin films of the SCO Hofmann-type coordination polymer [Fe(py)2 {Pt(CN)4 }] (py = pyridine) onto monolayers of 1T and 2H MoS2 polytypes are grown. The resulting hybrid heterostructures are characterized by GIXRD, XAS, XPS, and EXAFS to get information on the structure and the specific interactions generated at the interface, as well as on the spin transition. The use of a layer-by-layer results in SCO/2D heterostructures, with crystalline and well-oriented [Fe(py)2 {Pt(CN)4 }]. Unlike with conventional Au or SiO2 substrates, no intermediate self-assembled monolayer is required, thanks to the surface S atoms. Furthermore, it is observed that the higher presence of Fe3+ in the 2H heterostructures hinders an effective spin transition for [Fe(py)2 {Pt(CN)4 }] films thinner than 8 nm. Remarkably, when using 1T MoS2 , this transition is preserved in films as thin as 4 nm, due to the reducing character of this metallic substrate. These results highlight the active role that 2D materials play as substrates in hybrid molecular/2D heterostructures.

Understanding the Surface Regeneration and Reactivity of Garnet Solid-State Electrolytes.

Garnet solid-electrolyte-based Li-metal batteries can be used in energy storage devices with high energy densities and thermal stability. However, the tendency of garnets to form lithium hydroxide and carbonate on the surface in an ambient atmosphere poses significant processing challenges. In this work, the decomposition of surface layers under various gas environments is studied by using two surface-sensitive techniques, near-ambient-pressure X-ray photoelectron spectroscopy and grazing incidence X-ray diffraction. It is found that heating to 500 °C under an oxygen atmosphere (of 1 mbar and above) leads to a clean garnet surface, whereas low oxygen partial pressures (i.e., in argon or vacuum) lead to additional graphitic carbon deposits. The clean surface of garnets reacts directly with moisture and carbon dioxide below 400 and 500 °C, respectively. This suggests that additional CO2 concentration controls are needed for the handling of garnets. By heating under O2 along with avoiding H2O and CO2, symmetric cells with less than 10 Ωcm2 interface resistance are prepared without the use of any interlayers; plating currents of >1 mA cm-2 without dendrite initiation are demonstrated.

X-ray driven and intrinsic dynamics in protein gels.

We use X-ray photon correlation spectroscopy to investigate how structure and dynamics of egg white protein gels are affected by X-ray dose and dose rate. We find that both, changes in structure and beam-induced dynamics, depend on the viscoelastic properties of the gels with soft gels prepared at low temperatures being more sensitive to beam-induced effects. Soft gels can be fluidized by X-ray doses of a few kGy with a crossover from stress relaxation dynamics (Kohlrausch-Williams-Watts exponents [Formula: see text] to 2) to typical dynamical heterogeneous behavior ([Formula: see text]1) while the high temperature egg white gels are radiation-stable up to doses of 15 kGy with [Formula: see text]. For all gel samples we observe a crossover from equilibrium dynamics to beam induced motion upon increasing X-ray fluence and determine the resulting fluence threshold values [Formula: see text]. Surprisingly small threshold values of [Formula: see text] s[Formula: see text] nm[Formula: see text] can drive the dynamics in the soft gels while for stronger gels this threshold is increased to [Formula: see text] s[Formula: see text] nm[Formula: see text]. We explain our observations with the viscoelastic properties of the materials and can connect the threshold dose for structural beam damage with the dynamic properties of beam-induced motion. Our results suggest that soft viscoelastic materials can display pronounced X-ray driven motion even for low X-ray fluences. This induced motion is not detectable by static scattering as it appears at dose values well below the static damage threshold. We show that intrinsic sample dynamics can be separated from X-ray driven motion by measuring the fluence dependence of the dynamical properties.

Breathing porous liquids based on responsive metal-organic framework particles.

Responsive metal-organic frameworks (MOFs) that display sigmoidal gas sorption isotherms triggered by discrete gas pressure-induced structural transformations are highly promising materials for energy related applications. However, their lack of transportability via continuous flow hinders their application in systems and designs that rely on liquid agents. We herein present examples of responsive liquid systems which exhibit a breathing behaviour and show step-shaped gas sorption isotherms, akin to the distinct oxygen saturation curve of haemoglobin in blood. Dispersions of flexible MOF nanocrystals in a size-excluded silicone oil form stable porous liquids exhibiting gated uptake for CO2, propane and propylene, as characterized by sigmoidal gas sorption isotherms with distinct transition steps. In situ X-ray diffraction studies show that the sigmoidal gas sorption curve is caused by a narrow pore to large pore phase transformation of the flexible MOF nanocrystals, which respond to gas pressure despite being dispersed in silicone oil. Given the established flexible nature and tunability of a range of MOFs, these results herald the advent of breathing porous liquids whose sorption properties can be tuned rationally for a variety of technological applications.

Left atrial strain parameters derived by echocardiography are impaired in patients with acute myocarditis and preserved systolic left ventricular function.

PURPOSE: Data derived by cardiac magnetic resonance (CMR) feature tracking suggest that not only left ventricular but also left atrial function is impaired in patients with acute myocarditis. Therefore, we investigated the diagnostic value of speckle tracking echocardiography of the left ventricle and left atrium in patients with acute myocarditis and normal left ventricular ejection fraction (LVEF). METHODS AND RESULTS: 30 patients with acute myocarditis confirmed by CMR according to the Lake Louise criteria and 20 healthy controls were analyzed including global longitudinal strain (GLS) and left atrial (LA) strain parameters. Although preserved LVEF was present in both groups, GLS was significantly lower in patients with acute myocarditis (GLS - 19.1 ± 1.8% vs. GLS - 22.1 ± 1.7%, p < 0.001). Further diastolic dysfunction measured by E/e' mean was significantly deteriorated in the myocarditis group compared to the control group (E/e' mean 6.4 ± 1.6 vs. 5.5 ± 1.0, p = 0.038). LA reservoir function (47.6 ± 10.4% vs. 55.5 ± 10.8%, p = 0.013) and LA conduit function (-33.0 ± 9.6% vs. -39.4 ± 9.5%, p = 0.024) were significantly reduced in patients with acute myocarditis compared to healthy controls. Also left atrial stiffness index (0.15 ± 0.05 vs. 0.10 ± 0.03, p = 0.003) as well as left atrial filling index (1.67 ± 0.47 vs. 1.29 ± 0.34, p = 0.004) were deteriorated in patients with myocarditis compared to the control group. CONCLUSION: In patients with acute myocarditis and preserved LVEF not only GLS but also LA reservoir function, LA conduit function and left atrial stiffness index as well as left atrial filling index were impaired compared to healthy controls indicating ventricular diastolic dysfunction and elevated LV filling pressures.

Impact of transcatheter edge-to-edge mitral valve repair on central sleep apnoea.

AIMS: Sleep-disordered breathing (SDB) and its subtype central sleep apnoea (CSA) are highly prevalent in patients with heart failure and associated with worse prognosis. Whereas pharmacological therapy of heart failure has been shown to ameliorate CSA, results from previous studies on the effect of mitral regurgitation therapy on SDB are contradicting. The aim of this study was to assess the impact of transcatheter edge-to-edge mitral valve repair (TEER) on prevalence and severity of CSA. METHODS AND RESULTS: We enrolled 47 patients undergoing TEER for symptomatic mitral regurgitation in a prospective study. Secondary mitral regurgitation and left ventricular ejection fraction < 50% were present in 79% and 68% of patients, respectively. Respiratory polygraphy was performed before TEER in a compensated condition and four weeks after the procedure. 34 patients completed the follow-up. At baseline, 19 (56%) patients showed moderate-to-severe SDB, of whom 13 (68%) were classified as CSA. Both apnoea-hypopnoea index and percentage of recorded time spent in Cheyne-Stokes respiration strongly decreased from baseline to follow-up (median [IQR] 16 [7-30] vs. 7 [4-15] /h, p = 0.007; 6 [0-34] vs. 0 [0-8] %, p = 0.008). Median relative reduction of central apnoea index was 75% (p = 0.023), while obstructive apnoea index did not change significantly. Increase in stroke volume after TEER and high systolic pulmonary artery pressure at baseline predicted a > 50% reduction of both Apnoea-hypopnoea index and Cheyne-Stokes respiration. CONCLUSION: TEER is associated with a significant short-term reduction of CSA and Cheyne-Stokes respiration in high-risk patients, strengthening its value as an effective treatment option for advanced heart failure.

Atrial Fibrillation Burden Specifically Determines Human Ventricular Cellular Remodeling.

BACKGROUND: Atrial fibrillation (AF) can either be a consequence or an underlying mechanism of left ventricular systolic dysfunction. Patients included in the CASTLE-AF (Catheter Ablation vs. Standard Conventional Treatment in Patients With LV Dysfunction and AF) trial who suffered from AF and left ventricular systolic dysfunction benefited from an AF burden <50% after catheter ablation compared with those patients with an AF burden >50%. OBJECTIVES: This analysis tried to explain the clinical findings of the CASTLE-AF trial regarding AF burden in a "back-to-bench" approach. METHODS: To study the ventricular effects of different AF burdens, experiments were performed using human ventricular induced pluripotent stem cell-derived cardiomyocytes undergoing in vitro AF simulation. Epifluorescence microscopy, action potential measurements, and measurements of sarcomere regularity were conducted. RESULTS: Induced pluripotent stem cell-derived cardiomyocytes stimulated with AF burden of 60% or higher displayed typical hallmarks of heart failure. Ca2+ transient amplitude was significantly reduced indicating negative inotropic effects. Action potential duration was significantly prolonged, which represents a potential trigger for arrhythmias. A significant decrease of sarcomere regularity could explain impaired cardiac contractility in patients with high AF burden. These effects were more pronounced after 7 days of AF simulation compared with 48 hours. CONCLUSIONS: Significant functional and structural alterations occurred at the cellular level at a threshold of ∼50% AF burden as it was observed to be harmful in the CASTLE-AF trial. Therefore, these translational results may help to understand the findings of the CASTLE-AF trial.

Corrigendum: Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial.

[This corrects the article DOI: 10.3389/fmed.2022.973240.].

The interaction of viral fusion peptides with lipid membranes.

In this paper, we studied fusogenic peptides of class I-III fusion proteins, which are relevant to membrane fusion for certain enveloped viruses, in contact with model lipid membranes. We resolved the vertical structure and examined the adsorption or penetration behavior of the fusogenic peptides at phospholipid Langmuir monolayers with different initial surface pressures with x-ray reflectometry. We show that the fusion loops of tick-borne encephalitis virus (TBEV) glycoprotein E and vesicular stomatitis virus (VSV) G-protein are not able to insert deeply into model lipid membranes, as they adsorbed mainly underneath the headgroups with only limited penetration depths into the lipid films. In contrast, we observed that the hemagglutinin 2 fusion peptide (HA2-FP) and the VSV-transmembrane domain (VSV-TMD) can penetrate deeply into the membranes. However, in the case of VSV-TMD, the penetration was suppressed already at low surface pressures, whereas HA2-FP was able to insert even into highly compressed films. Membrane fusion is accompanied by drastic changes of the membrane curvature. To investigate how the peptides affect the curvature of model lipid membranes, we examined the effect of the fusogenic peptides on the equilibration of cubic monoolein structures after a phase transition from a lamellar state induced by an abrupt hydrostatic pressure reduction. We monitored this process in presence and absence of the peptides with small-angle x-ray scattering and found that HA2-FP and VSV-TMD drastically accelerate the equilibration, while the fusion loops of TBEV and VSV stabilize the swollen state of the lipid structures. In this work, we show that the class I fusion peptide of HA2 penetrates deeply into the hydrophobic region of membranes and is able to promote and accelerate the formation of negative curvature. In contrast, we found that the class II and III fusion loops of TBEV and VSV tend to counteract negative membrane curvature.

Tachycardiomyopathy entails a dysfunctional pattern of interrelated mitochondrial functions.

Tachycardiomyopathy is characterised by reversible left ventricular dysfunction, provoked by rapid ventricular rate. While the knowledge of mitochondria advanced in most cardiomyopathies, mitochondrial functions await elucidation in tachycardiomyopathy. Pacemakers were implanted in 61 rabbits. Tachypacing was performed with 330 bpm for 10 days (n = 11, early left ventricular dysfunction) or with up to 380 bpm over 30 days (n = 24, tachycardiomyopathy, TCM). In n = 26, pacemakers remained inactive (SHAM). Left ventricular tissue was subjected to respirometry, metabolomics and acetylomics. Results were assessed for translational relevance using a human-based model: induced pluripotent stem cell derived cardiomyocytes underwent field stimulation for 7 days (TACH-iPSC-CM). TCM animals showed systolic dysfunction compared to SHAM (fractional shortening 37.8 ± 1.0% vs. 21.9 ± 1.2%, SHAM vs. TCM, p < 0.0001). Histology revealed cardiomyocyte hypertrophy (cross-sectional area 393.2 ± 14.5 µm2 vs. 538.9 ± 23.8 µm2, p < 0.001) without fibrosis. Mitochondria were shifted to the intercalated discs and enlarged. Mitochondrial membrane potential remained stable in TCM. The metabolite profiles of ELVD and TCM were characterised by profound depletion of tricarboxylic acid cycle intermediates. Redox balance was shifted towards a more oxidised state (ratio of reduced to oxidised nicotinamide adenine dinucleotide 10.5 ± 2.1 vs. 4.0 ± 0.8, p < 0.01). The mitochondrial acetylome remained largely unchanged. Neither TCM nor TACH-iPSC-CM showed relevantly increased levels of reactive oxygen species. Oxidative phosphorylation capacity of TCM decreased modestly in skinned fibres (168.9 ± 11.2 vs. 124.6 ± 11.45 pmol·O2·s-1·mg-1 tissue, p < 0.05), but it did not in isolated mitochondria. The pattern of mitochondrial dysfunctions detected in two models of tachycardiomyopathy diverges from previously published characteristic signs of other heart failure aetiologies.

Recirculation in single lumen cannula venovenous extracorporeal membrane oxygenation: A non-randomized bi-centric trial.

Background: Recirculation is a common problem in venovenous (VV) extracorporeal membrane oxygenation (ECMO). The aims of this study were to compare recirculation fraction (Rf) between femoro-jugular and jugulo-femoral VV ECMO configurations, to identify risk factors for recirculation and to assess the impact on hemolysis. Methods: Patients in the medical intensive care unit (ICU) at the University Medical Center Regensburg, Germany receiving VV ECMO with femoro-jugular, and jugulo-femoral configuration at the ECMO Center Karolinska, Sweden, were included in this non-randomized prospective study. Total ECMO flow (Q EC ), recirculated flow (QREC), and recirculation fraction Rf = QREC/QEC were determined using ultrasound dilution technology. Effective ECMO flow (QEFF) was defined as QEFF = QEC * (1-Rf). Demographics, cannula specifics, and markers of hemolysis were assessed. Survival was evaluated at discharge from ICU. Results: Thirty-seven patients with femoro-jugular configuration underwent 595 single-point measurements and 18 patients with jugulo-femoral configuration 231 measurements. Rf was lower with femoro-jugular compared to jugulo-femoral configuration [5 (0, 11) vs. 19 (13, 28) %, respectively (p < 0.001)], resulting in similar QEFF [2.80 (2.21, 3.39) vs. 2.79 (2.39, 3.08) L/min (p = 0.225)] despite lower QEC with femoro-jugular configuration compared to jugulo-femoral [3.01 (2.40, 3.70) vs. 3.57 (3.05, 4.06) L/min, respectively (p < 0.001)]. In multivariate regression analysis, the type of configuration, distance between the two cannula tips, ECMO flow, and heart rate were significantly associated with Rf [B (95% CI): 25.8 (17.6, 33.8), p < 0.001; 960.4 (960.7, 960.1), p = 0.009; 4.2 (2.5, 5.9), p < 0.001; 960.1 (960.2, 0.0), p = 0.027]. Hemolysis was similar in subjects with Rf > 8 vs. ≤ 8%. Explorative data on survival showed comparable results in the femoro-jugular and the jugulo-femoral group (81 vs. 72%, p = 0.455). Conclusion: VV ECMO with femoro-jugular configuration caused less recirculation. Further risk factors for higher Rf were shorter distance between the two cannula tips, higher ECMO flow, and lower heart rate. Rf did not affect hemolysis.

Interaction of Human Resistin with Human Islet Amyloid Polypeptide at Charged Phospholipid Membranes.

An X-ray reflectivity study on the interaction of recombinant human resistin (hRes) with fibrillation-prone human islet amyloid polypeptide (hIAPP) at anionic phospholipid Langmuir films as model membranes is presented. Aggregation and amyloid formation of hIAPP is considered the main mechanism of pancreatic ß-cell loss in patients with type 2 diabetes mellitus. Resistin shows a chaperone-like ability, but also tends to form aggregates by itself. Resistin and hIAPP cross multiply metabolism pathways. In this study, we researched the potential protective effects of resistin against hIAPP-induced lipid membrane rupture. The results demonstrate that resistin can inhibit or prevent hIAPP adsorption even in the presence of aggregation-promoting negatively charged lipid interfaces. Moreover, we found strong hydrophobic interactions of resistin at the bare buffer-air interface.

Nondestructive Compression and Fluidization of Phospholipid Monolayers by Gaseous and Aerolized Perfluorocarbons: Promising Substances for Lung Surfactant Treatment.

We present a surface-sensitive X-ray scattering study on the influence of gaseous and aerolized perfluorocarbons (FCs) on zwitterionic and anionic phospholipid Langmuir films, which serve as a simplified model system of lung surfactants. It was found that small gaseous FC molecules like F-propane and F-butane penetrate phospholipid monolayers and accumulate between the alkyl chains and form islands. This clustering process can trigger the formation of lipid crystallites at low initial surface pressures. In contrast, the large linear FC F-octyl bromide fluidizes membranes, causing a dissolution of crystalline domains. The bicyclic FC F-decalin accumulates between the alkyl chains of 1,2-dipalmitoyl phosphatidylcholine but cannot penetrate the more densely packed 1,2-dipalmitoyl phosphatidic acid films because of its size. The effects of FCs on lung surfactants are discussed in the framework of currently proposed therapeutic methods for acute respiratory distress syndrome using FC gases, vapor, or aerosol ventilation causing monolayer fluidization effects. This study implies that the highly biocompatible and nontoxic FCs could be beneficial in the treatment of lung diseases with injured nonfunctional lung surfactants in a novel approach for ventilation.

SARS-CoV-2 Vaccine-Induced Immune Thrombotic Thrombocytopenia with Venous Thrombosis, Pulmonary Embolism, and Adrenal Haemorrhage: A Case Report with Literature Review.

Vaccine-induced immune thrombotic thrombocytopenia (VITT) with venous thrombosis is a rare complication of SARS-CoV-2 vaccination with ChAdOx1 (AstraZeneca) and AD26.COV2.S (Johnson & Johnson, New Brunswick, NJ, USA) associated with high mortality. At present, there are no known differences in the pathophysiology or risk factors of VITT with the AstraZeneca vaccine (ChAdOx1) compared with the Johnson & Johnson vaccine (AD26.COV2.S). Herein, we present the case of a healthy 39-year-old patient with VITT after having received the vaccine Ad26.COV2.S. Ten days after vaccination, the patient developed a deep vein thrombosis and subsequent pulmonary embolism. A computed tomography scan of the abdomen showed adrenal gland bleeding and an adrenocorticotrophic hormone stimulation test diagnosed adrenal insufficiency. Therapy with intravenous immunoglobulin, argatroban and hydrocortisone was initiated immediately after diagnosis. The patient left the hospital 22 days after admission with the diagnosis of adrenal insufficiency but otherwise in good health. To the best of our knowledge, five cases of VITT and adrenal bleeding have been described to date in the literature but the presented case was the first to occur after immunisation with the vaccine of Johnson & Johnson. In summary, VITT-associated adrenal dysfunction is a very rare complication of vaccination with an adenoviral vector-based COVID-19 vaccine.

Effects of Atrial Fibrillation on the Human Ventricle.

RATIONALE: Atrial fibrillation (AF) and heart failure often coexist, but their interaction is poorly understood. Clinical data indicate that the arrhythmic component of AF may contribute to left ventricular (LV) dysfunction. OBJECTIVE: This study investigates the effects and molecular mechanisms of AF on the human LV. METHODS AND RESULTS: Ventricular myocardium from patients with aortic stenosis and preserved LV function with sinus rhythm or rate-controlled AF was studied. LV myocardium from patients with sinus rhythm and patients with AF showed no differences in fibrosis. In functional studies, systolic Ca2+ transient amplitude of LV cardiomyocytes was reduced in patients with AF, while diastolic Ca2+ levels and Ca2+ transient kinetics were not statistically different. These results were confirmed in LV cardiomyocytes from nonfailing donors with sinus rhythm or AF. Moreover, normofrequent AF was simulated in vitro using arrhythmic or rhythmic pacing (both at 60 bpm). After 24 hours of AF-simulation, human LV cardiomyocytes from nonfailing donors showed an impaired Ca2+ transient amplitude. For a standardized investigation of AF-simulation, human iPSC-cardiomyocytes were tested. Seven days of AF-simulation caused reduced systolic Ca2+ transient amplitude and sarcoplasmic reticulum Ca2+ load likely because of an increased diastolic sarcoplasmic reticulum Ca2+ leak. Moreover, cytosolic Na+ concentration was elevated and action potential duration was prolonged after AF-simulation. We detected an increased late Na+ current as a potential trigger for the detrimentally altered Ca2+/Na+-interplay. Mechanistically, reactive oxygen species were higher in the LV of patients with AF. CaMKII (Ca2+/calmodulin-dependent protein kinase IIδc) was found to be more oxidized at Met281/282 in the LV of patients with AF leading to an increased CaMKII activity and consequent increased RyR2 phosphorylation. CaMKII inhibition and ROS scavenging ameliorated impaired systolic Ca2+ handling after AF-simulation. CONCLUSIONS: AF causes distinct functional and molecular remodeling of the human LV. This translational study provides the first mechanistic characterization and the potential negative impact of AF in the absence of tachycardia on the human ventricle.