Right superior pulmonary vein parameter determined by three-dimensional transesophageal echocardiography is an independent predictor of the outcome after cryoballoon isolation of the pulmonary veins

Background: A direct comparison of three-dimensional transesophageal echocardiography (3DTEE)and cardiac computed tomography imaging has demonstrated good inter-technique agreement for thefollowing pulmonary vein (PV) parameters: the ostium area of the right superior PV (RSPV) and itsmajor (a) and minor axis (b) diameters, the left lateral ridge and the minor axis (b) diameter of the leftsuperior PV. Herein, under investigation, was the predictive value of these parameters for arrhythmiarecurrence (AR) after PV isolation with the 28 mm second generation cryoballoon (CBG2).Methods: One hundred eleven patients (67 men, mean age 58.06 ± 10.58 years) undergoing 3DTEEbefore PV isolation with the CBG2 for paroxysmal atrial fibrillation were followed. “Point by point” redointervention was offered in case of AR and reconnected PVs were defined.Results: During a mean follow-up of 617 ± 258.86 days, 65 (58.9%) patients remained free of AR.Longer RSPV b was found to be the only significant predictor for AR (hazard ratio [HR] 1.059; 95%confidence interval [CI] 1.000–1.121; p = 0.048). RSPV b ≥ 28 mm resulted in a threefold (HR 3.010;95% CI 1.270–7.134, p = 0.012) increase in the risk of AR. The association of RSPV b with AR wasindependent of the biophysical parameters of cryoapplications. In 25 “redo” patients, reconnections werefound 1.75 times more likely in the RSPV than in the other 3 PVs altogether.Conclusions: Right superior PV b measured with 3DTEE might be a significant predictor of AR afterPV isolation with the CBG2. In case of RSPV b exceeding 28 mm, alternative PV isolation techniquesor use of a larger balloon might be considered

Raman Spectral Signatures of Serum-Derived Extracellular Vesicle-Enriched Isolates May Support the Diagnosis of CNS Tumors

Investigating the molecular composition of small extracellular vesicles (sEVs) for tumor diagnostic purposes is becoming increasingly popular, especially for diseases for which diagnosis is challenging, such as central nervous system (CNS) malignancies. Thorough examination of the molecular content of sEVs by Raman spectroscopy is a promising but hitherto barely explored approach for these tumor types. We attempt to reveal the potential role of serum-derived sEVs in diagnosing CNS tumors through Raman spectroscopic analyses using a relevant number of clinical samples. A total of 138 serum samples were obtained from four patient groups (glioblastoma multiforme, non-small-cell lung cancer brain metastasis, meningioma and lumbar disc herniation as control). After isolation, characterization and Raman spectroscopic assessment of sEVs, the Principal Component Analysis–Support Vector Machine (PCA–SVM) algorithm was performed on the Raman spectra for pairwise classifications. Classification accuracy (CA), sensitivity, specificity and the Area Under the Curve (AUC) value derived from Receiver Operating Characteristic (ROC) analyses were used to evaluate the performance of classification. The groups compared were distinguishable with 82.9–92.5% CA, 80–95% sensitivity and 80–90% specificity. AUC scores in the range of 0.82–0.9 suggest excellent and outstanding classification performance. Our results support that Raman spectroscopic analysis of sEV-enriched isolates from serum is a promising method that could be further developed in order to be applicable in the diagnosis of CNS tumors

Pilot analysis of the usefulness of mortality risk score systems at resuscitated patients

Introduction: Sudden cardiac death is one of the most significant cardiovascular causes of death worldwide. Although there have been immense methodological and technical advances in the field of cardiopulmonary resuscitation and following intensive care in the last decade, currently there are only a few validated risk-stratification scoring systems for the quick and reliable estimation of the mortality risk of these patients at the time of admission to the intensive care unit. Objective: Our aim was to correlate the mortality prediction risk points calculated by CardShock Risk Score (CSRS) and modified (m) CSRS based on the admission data of the post-cardiac arrest syndrome (PCAS) patients. Methods: The medical records of 172 out-of-hospital resuscitated cardiac arrest patients, who were admitted at the Heart and Vascular Centre of Semmelweis University, were screened retrospectively. Out of the 172 selected patients, 123 were eligible for inclusion to calculate CSRS and mCSRS. Based on CSRS score, we generated three different groups of patients, with scores 1 to 3, 4 to 6, and 7+, respectively. Mortality data of the groups were compared by log-rank test. Results: Mean age of the patients was 63.6 years (69% male), the cause of sudden cardiac death was acut coronary syndrome in 80% of the cases. The early and late mortality was predicted by neurological status, serum lactate level, renal function, initial rhythm, and the need of catecholamines. Using mCSRS, a significant survival difference was proven in between the groups "1-3" vs "4-6" (p Conclusion: Compared to the CSRS, the mCSRS expanded with the 2 additional weighting points differentiates more specifically the low-moderate and high survival groups in the PCAS patient population treated in our institute.Peer reviewe

Friction Coefficient Measured on a Single WS2\mathbf{WS}_\mathbf{2} WS 2 Nanoparticle: An In Situ Transmission Electron Microscope Experiment

International audienc

Structure and Formation of Soot Particles from Tribofilm Decomposition Under Real Engine Conditions

Lubrication of an internal combustion engine is critical for unwanted energy and material losses. Zinc dialkyldithiophosphate (ZDDP) is a commonly used anti-wear additive that forms by in situ decomposition a protecting interface between sliding surfaces. The interface consists of the tribofilm on both surfaces and oil in the contact. Soot particles from a petrol engine and gas engine were analyzed using X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM) techniques: electron energy loss spectroscopy (EELS) and energy dispersive X-ray spectroscopy (EDS). These techniques revealed that the end-products in soot contain 3-5 nm ZnO-based particles with additions of phosphorus and sulfur, originating from the ZDDP anti-wear additive. Our results unravel the tribofilm decomposition under real field conditions and hint toward potentially unidentified hazards with respect to ZDDP-containing lubricants

Mechanical characterization of diesel soot nanoparticles: in situ compression in a transmission electron microscope and simulations

International audienceIncomplete fuel burning inside an internal combustion engine results in the creation of soot in the form of nanoparticles. Some of these soot nanoparticles (SNP) become adsorbed into the lubricating oil film present on the cylinder walls, which adversely affects the tribological performance of the lubricant. In order to better understand the mechanisms underlying the wear caused by SNPs, it is important to understand the behavior of SNPs and to characterize potential changes in their mechanical properties (e.g. hardness) caused by (or during) mechanical stress. In this study, the behavior of individual SNPs originating from diesel engines was studied under compression. The experiments were performed in a transmission electron microscope using a nanoindentation device. The nanoparticles exhibited elasto-plastic behavior in response to consecutive compression cycles. From the experimental data, the Young's modulus and hardness of the SNPs were calculated. The Young's modulus and hardness of the nanoparticles increased with the number of compression cycles. Using an electron energy loss spectroscopy technique, it was shown that the sp(2)/sp(3) ratio within the compressed nanoparticle decreases, which is suggested to be the cause of the increase in elasticity and hardness. In order to corroborate the experimental findings, molecular dynamics simulations of a model SNP were performed. The SNP model was constructed using carbon and hydrogen atoms with morphology and composition comparable to those observed in the experiment. The model SNP was subjected to repeated compressions between two virtual rigid walls. During the simulation, the nanoparticle exhibited elasto-plastic behavior like that in the experiments. The results of the simulations confirm that the increase in the elastic modulus and hardness is associated with a decrease in the sp(2/)sp(3) ratio

Mechanical response of gasoline soot nanoparticles under compression: An in situ TEM study

International audienceGasoline soot nanoparticles (SNPs) were studied by performing in situ compression tests on individual nanoparticles inside a transmission electron microscope. After consecutive compressions, the SNPs exhibited an elasto-plastic behavior, and an increasing trend in Young's modulus and hardness values. Molecular dynamics were used to simulate compression cycles, the results of which confirmed the observations made during the experiments. The simulations were used to investigate how the different structural components of the nanoparticles affect their elastic and plastic response. By comparing the behavior of gasoline and diesel SNPs under compression, differences were observed both experimentally and in the simulations: the former were found to be more elastic and less prone to become hard under compression compared to the latter

Small Extracellular Vesicles Isolated from Serum May Serve as Signal-Enhancers for the Monitoring of CNS Tumors

Liquid biopsy-based methods to test biomarkers (e.g., serum proteins and extracellular vesicles) may help to monitor brain tumors. In this proteomics-based study, we aimed to identify a characteristic protein fingerprint associated with central nervous system (CNS) tumors. Overall, 96 human serum samples were obtained from four patient groups, namely glioblastoma multiforme (GBM), non-small-cell lung cancer brain metastasis (BM), meningioma (M) and lumbar disc hernia patients (CTRL). After the isolation and characterization of small extracellular vesicles (sEVs) by nanoparticle tracking analysis (NTA) and atomic force microscopy (AFM), liquid chromatography -mass spectrometry (LC-MS) was performed on two different sample types (whole serum and serum sEVs). Statistical analyses (ratio, Cohen’s d, receiver operating characteristic; ROC) were carried out to compare patient groups. To recognize differences between the two sample types, pairwise comparisons (Welch’s test) and ingenuity pathway analysis (IPA) were performed. According to our knowledge, this is the first study that compares the proteome of whole serum and serum-derived sEVs. From the 311 proteins identified, 10 whole serum proteins and 17 sEV proteins showed the highest intergroup differences. Sixty-five proteins were significantly enriched in sEV samples, while 129 proteins were significantly depleted compared to whole serum. Based on principal component analysis (PCA) analyses, sEVs are more suitable to discriminate between the patient groups. Our results support that sEVs have greater potential to monitor CNS tumors, than whole seru

Three-dimensional transesophageal echocardiographic evaluation of pulmonary vein anatomy prior to cryoablation: validation with cardiac CT scan

Abstract Background Anatomical characteristics of the left atrium and the pulmonary veins (PVs) may be relevant to the success rate of cryoballoon (CB)-ablation for atrial fibrillation (AF). Cardiac computed tomography (CCT) is considered as the gold standard for preablation imaging. Recently, three-dimensional transesophageal echocardiography (3DTOE) has been proposed for preprocedural assessment of cardiac structures relevant to CB-ablation. The accuracy of 3DTOE has not been validated by other imaging modalities. Objective We prospectively evaluated the feasibility and the accuracy of 3DTOE imaging for the assessment of left atrial and PV structures prior to pulmonary vein isolation (PVI). In addition, CCT was used to validate the measurements obtained with 3DTOE. Methods PV anatomy of 67 patients (59.7% men, mean age 58.5 ± 10.5 years) was assessed using both 3DTOE and CCT scan prior to PVI with the Arctic Front CB. The following parameters were measured bilaterally: PV ostium area (OA), the major and minor axis diameters of the ostium (a > b) and the width of the carina between the superior and the inferior PVs. In addition, the width of the left lateral ridge (LLR) between the left atrial appendage and the left superior PV. Evaluation of inter-technique agreement was based on linear regression with Pearson correlation coefficient (PCC) and Bland–Altman analysis of biases and limits of agreement. Results Moderate positive correlation (PCC 0.5–0.7) was demonstrated between the two imaging methods for the right superior PV’s OA and both axis diameters, the width of the LLR and left superior PV (LSPV) minor axis diameter (b) with limits of agreement ˂50% and no significant biases. Low positive or negligible correlation (PCC < 0.5) was found for both inferior PV parameters. Conclusions Detailed assessment of the right superior PV parameters, LLR and LSPV b is feasible with 3DTOE prior to AF ablation. This 3DTOE measurements demonstrated a clinically acceptable inter-technique agreement with those obtained with CCT. Graphical Abstrac