A distinct septal pattern of late gadolinium enhancement specific for COVID-induced myocarditis: A multicenter cardiovascular magnetic resonance study

BACKGROUND: Coronavirus disease-19 (COVID-19) is a great medical challenge provoking acute respiratory distress, pulmonary manifestations, and cardiovascular (CV) consequences. AIMS: This study compares cardiac injury in COVID-19 myocarditis patients with non-COVID myocarditis patients. METHODS: Patients who recovered from COVID-19 were scheduled for cardiovascular magnetic resonance (CMR) owing to clinical myocarditis suspicion. The retrospective non-COVID-19 myocarditis (2018-2019) group was enrolled (n=221 patients). All patients underwent a contrast-enhanced CMR, conventional myocarditis protocol, and late gadolinium enhancement (LGE). The COVID study group included 552 patients with a mean (standard deviation [SD]) age 45.9 (12.6) years old.   RESULTS: CMR assessment confirmed a myocarditis-like LGE in 46% of the cases (68.5% of the segments with LGE <25% transmural extent), left ventricular (LV) dilatation in 10%, and systolic dysfunction in 16%. The COVID-myocarditis group showed a smaller median (interquartile range [IQR]) LV LGE (4.4% [2.9%–8.1%] vs. 5.9% [4.4%–11.8%]; P <0.001), lower LVEDV (144.6 [125.5–178] ml vs. 162.8 [136.6–194] ml; P <0.001), limited functional consequence (LVEF, 59% [54.1%–65%] vs. 58% [52%–63%]; P = 0.01), and a higher rate of pericarditis (13.6% vs. 6%; P = 0.03) compared to non-COVID myocarditis. The COVID-induced injury was more frequent in septal segments (2, 3, 14), and non-COVID myocarditis showed higher affinity to lateral wall segments (P <0.01). Neither obesity nor age was associated with LV injury or remodeling in subjects with COVID-myocarditis. CONCLUSIONS: COVID-19-induced myocarditis is associated with minor LV injury with a significantly more frequent septal pattern and a higher pericarditis rate than non-COVID-19 myocarditis

Štěpení kyslíku při pokojové teplotě na vzdálených dvouatomových centrech přechodových kovů v zeolitech pro přímou oxidaci metanu na metanol

Here we demonstrate for the first time the splitting of dioxygen at RT over distant binuclear transition metal (M = Ni, Mn, and Co) centers stabilized in ferrierite zeolite. Cleaved dioxygen directly oxidized methane to methanol, which can be released without the aid of an effluent to the gas phase at RT.Zde demonstrujeme první štěpení kyslíku při pokojové teplotě na vzdálených centrech přechodových kovů v zeolitech typu FER. Aktivovaný kyslík poté oxidoval metan na metanol při pokojové teplotě

The Photodynamic Properties and the Genotoxicity of Heat-Treated Silicalite-1 Films

We investigated the use of a supported silicalite-1 film (SF) as a promising coating for metallic materials used in the fabrication of prostheses. The role of carbonaceous residua present on high-temperature calcined-SF in generating singlet oxygen for future use as a sterilization method has also been addressed, and the potential genotoxicity of these residua in osteoblast-like cells has been investigated. Calcination of as-synthesized SF induced the appearance of a rather complicated mixture of aliphatic and aromatic species on its outer surface. A series of variously volatile polycyclic aromatic hydrocarbons (PAH), including naphthalene, fluorene, phenanthrene, anthracene, fluoranthene, and pyrene, were identified in micromole concentrations. Irradiation of these PAHs on calcined-SF immersed in air-saturated chloroform led to the formation of very low concentrations of singlet oxygen. However, an increased level of DNA damage was observed on calcined-SF by immunofluorescence staining of phosphorylated histone H2AX analyzed by flow cytometry

Nízkoteplotní selektivní oxidace metanu na vzdálených binukleárních kationtových centrech zeolitů

Highly active oxygen capable to selectively oxidize methane to methanol at low temperature can be prepared in transition-metal cation exchanged zeolites. Here we show that the alpha-oxygen stabilized by the negative charges of two framework aluminum atoms can be prepared by the dissociation of nitrous oxide over distant binuclear cation structures (M(II) ... M (II), M = cobalt, nickel, and iron) accommodated in two adjacent 6-rings forming cationic sites in the ferrierite zeolite. This alpha-oxygen species is analogous to that known only for iron exchanged zeolites. In contrast to divalent iron cations, only binuclear divalent cobalt cationic structures and not isolated divalent cobalt cations are active. Created methoxy moieties are easily protonated to yield methanol, formaldehyde, and formic acid which are desorbed to the gas phase without the aid of water vapor while previous studies showed that highly stable methoxy groups were formed on isolated iron cations in iron exchanged ZSM-5 zeolites.Vysoce aktivní kyslík dostupný pro selektivní oxidaci metanu na metanol při nízkých teplotách může být připraven iontovou výměnou v zeolitech

Stanovení Zn druhů, prostorového uspořádání a distribuce ve ferrieritu pomocí luminiscenční a FTIR spektroskopie

A methodology for the analysis of the siting of Zn2+ ions in extra-framework cationic sites of silicon-rich zeolite was developed and demonstrated on Zn-ferrierite samples (Si/Al 8.5, Zn/Al 0.04-0.33). This methodology is based on the FTIR spectroscopy of antisymmetric tetrahedral-octahedral-tetrahedral (T-O-T) vibrations of the zeolite framework perturbed by Zn2+ ions, combined with a complementary approach based on Zn2+ luminescence monitored by laser-induced time-resolved luminescence spectroscopy. Three vibration bands in the FTIR spectra of antisymmetric T-O-T vibrations of dehydrated zeolite reflect Zn2+ ligation in three extra-framework cationic sites of ferrierite zeolite. The band at 935 cm(-1) corresponds to Zn2+ ions in the alpha-site of ferrierite, the band at 917 cm(-1) correspondsto ions in beta-site, and the band at 902 cm(-1) correspondsto Zn2+ ions in the.-site. The extinction coefficient for quantitative analysis of Zn2+ ions in cationic sites was estimated and exhibited the same value for Zn2+ cations in all cationic sites, epsilon = 49.1 +/- 3.8 cm.mu mol(-1). In all Zn samples, Zn2+ siting in the beta-site prevails, while Zn2+ ions in the gamma-site are of low population or negligible. Time-resolved luminescence showed that bare Zn2+ ions in the extra-framework cationic sites can be distinguished from Zn2+ ions in ZnO by a decay time which is several magnitudes longer and a high sensitivity for quenching. The luminescence spectrum of Zn-ferrierites is composed of three bands at 545, 480, and 425 nm attributable to Zn2+ ions in the alpha-, beta-, and gamma-site with luminescence coefficients (for semiquantitative analysis) zeta(alpha) = 10.1, zeta(beta) = 9.4, and zeta(gamma) = 8.8 mmol/g of Zn2+ ions in the alpha-, beta-, and gamma-sites, respectively. The analysis of Zn ions in ferrierites showed that ZnH-ferrierites exclusively contain Zn2+ ions in cationic sites. In the case of the ZnNa-FER sample with maximum Zn loading (Zn/Al 0.33), a small amount of Zn-oxo species can be formed.Metodologie pro analýzu poloh Zn2+ iontů v extra-mřížkových kationtových polohách Si-bohatých zeolitů byla vyvinuta a demonstrována na Zn-ferrieritových vzorcích (Si/Al 8.5, Zn/Al 0.04-0.33). Metodologie je založena na FTIR a luminiscenční spektroskopii

Štěpení kyslíku na vzdálených dvoujaderných Fe centrech v zeolitech. Efekt lokálního uspořádání a mřížkové topologie

Activation of dioxygen is of extreme importance due to its potential for transformation of methane to valuable products and applications in other selective oxidation reactions. Distant binuclear cationic Fe(II) centers in Fe-ferrierite were shown to split dioxygen at room temperature to form a pair of very active oxygen species (i.e., alpha-oxygens) and subsequently oxidize methane to methanol at room temperature as well. Our study reveals that the activity in splitting dioxygen represents a general property of the distant binuclear cationic Fe(II) centers stabilized in the aluminosilicate matrix. Computational models of the ferrierite, beta, A, and mordenite zeolites with various Al sitings in the rings forming the cationic sites were investigated by periodic DFT calculations including molecular dynamics simulations. The results reveal that the Fe(II) sites stabilized in various zeolite matrices can split dioxygen if the two cationic sites forming the distant binuclear Fe(II) centers (i) face each other, (ii) are parallel, and (iii) are axial, and (iv) the Fe center dot center dot center dot Fe distance lies in a narrow range from ca. 7 to ca. 8 A (ca. 7-ca. 10 A for the distance between the two rings (forming the corresponding cationic sites) in empty zeolites since this distance is equal to or larger than the Fe center dot center dot center dot Fe distances). Our study opens the possibility of developing Fe-zeolite-based systems for the dioxygen activation employed for direct oxidations using various zeolite matrices.Aktivace kyslíku je extrémně důležitá z důvodu potenciálu pro transformaci metanu na vhodné produkty a aplikace v jiných oxidačních reakcích. Vzdálená dvoujaderná Fe(II) centra v Fe-FER vykázala štěpení kyslíku při pokojové teplotě do formy páru aktivních kyslíkových druhů a následnou oxidaci metanu na metanol při pokojové teplotě

Strukturní stabilita ferieritu obsahujícího kov za podmínek vysokoteplotního rozkladu N2O

Ferrierite based catalyst is expected to be used for high-temperature decomposition of N2O. The stability of the ferrierite structure and divalent cations in ferrierite in this process were analysed using XRD, SEM, FTIR, Al-27 and Si-29 MAS NMR. This study provides detailed information regarding to Al removal from zeolite that is either involved in the Bronsted acid sites or formation of local cationic sites responsible for bonding divalent cations. The Al atoms, which stabilize divalent cations in cationic positions, have the potential to be resistant to prolonged exposure to the conditions of high-temperature decomposition of N2O. The presence of water led to the destruction of the iron active sites for N2O decomposition in iron ferrierite. Moreover, the negative role of residual sodium ions eventually remaining in the commercial ferrierite was proven to induce the irreversible collapse of the zeolite framework.Očekává se, že katalyzátor na bázi ferrieritu bude využíván pro vysokoteplotní rozklad N2O. Stabilita ferrieritové struktury a dvojmocných kationtů ve ferrieritu byla v tomto procesu analyzována pomocí XRD, SEM, FTIR, Al-27 a Si-29 MAS NMR. Tato studie poskytuje podrobné informace týkající se odstranění Al ze zeolitu, který je buď zapojen do Bronstedových míst, nebo vytváří místní kationtová místa zodpovědná za vázání dvojmocných kationtů. Atomy Al, které stabilizují dvojmocné kationty v kationtových polohách, mají potenciál být rezistentní vůči dlouhodobému vystavení podmínkám vysokoteplotního rozkladu N2O. Přítomnost vody vedla ke zničení aktivních míst železa pro rozklad N2O v ferrieritu železa. Kromě toho se ukázala negativní role zbytkových sodných iontů, které zůstaly v komerčním ferrieritu, vyvolávající nevratné zhroucení zeolitové struktury