Thermodynamic Properties and Similarity of Stacked-Cup Multiwall Carbon Nanotubes and Graphite

The heat capacity of stacked-cup multiwall carbon nanotubes (MWCNTs) was measured in an adiabatic calorimeter over the temperature range of (5 to 370) K. Results are compared with literature data on various samples of CNTs and other carbon allotropes. The relatively large scatter of the heat capacity data for CNTs is discussed. The energy of combustion for MWCNTs was determined by combustion calorimetry, and the enthalpy of formation was found to be Δ_f<i>H</i>°_m = (0.6 ± 0.9) kJ·mol^–1. It is demonstrated that the thermodynamic properties of MWCNTs at <i>T</i> > 200 K are close to those of graphite. Equilibria of the synthesis of MWCNTs were considered

Thermodynamic Properties of Plant Biomass Components. Heat Capacity, Combustion Energy, and Gasification Equilibria of Lignin

Heat capacities and enthalpies of formation were determined for two samples of lignin obtained from rape straw by different methods. The obtained experimental results allowed us to obtain the values of thermodynamic properties for this material. The equilibria of the processes of lignin gasification were considered. The adiabatic temperatures of the gasification and energetic characteristics of the products of lignin thermolysis were evaluated

Physicochemical Properties of Imidazolium-Based Ionic Nanofluids: Density, Heat Capacity, and Enthalpy of Formation

The heat capacity of ionic nanofluids (INF) of stacked-cup multiwalled carbon nanotubes (MWCNT) and [C₄mim]­BF₄ and [C₄mim]­PF₆ ionic liquids (IL) as well as their components was measured over the temperature range of 80–370 K. The specific heat capacity of INF was found be an additive quantity of specific heat capacities of the components. The temperatures of glass transition and fusion of IL in INF did not observably change compared to pure IL. The enthalpy of formation of ([C₄mim]­BF₄+MWCNT) INF from its components was found to be negligible compared to the uncertainty of the measurements. All these facts confirm liophobic nature of the studied INF and provide the opportunity to predict thermodynamic properties of similar INF from the data on individual components. The apparent density of the studied MWCNT in INF is lower than those in their unstable dispersions with ionic and molecular liquids due to the high viscosity of INF not allowing penetration of ions into MWCNT and removal of gases from inner parts of MWCNT. The structural parameters of the studied MWCNT were estimated from the obtained density data

Characterization and comparative analysis of the Escherichia marmotae M-12 isolate from bank vole (Myodes glareolus)

Abstract The Escherichia marmotae is a bacterium of the Enterobacterales order, which was first isolated from the Himalayan marmot (Marmota himalayana). Recently E. marmotae has been shown to cause severe infections in humans. Wild animals were suggested to be a natural reservoir of this bacterium. The present study describes the first case of E. marmotae isolation from an apparently healthy wild bank vole (Myodes glareolus). Phenotype, as well as genotype-based techniques, were applied to characterize E. marmotae M-12 isolate. E. marmotae M-12 had the capsule-positive phenotype, high adhesion to human erythrocytes and HEp-2 cells as well as a low invasion into HEp-2 cells. E. marmotae M-12 was avirulent in mice. The phylogenomic analyses of E. marmotae showed dispersed phylogenetic structure among isolates of different origins. Virulome analysis of M-12 isolate revealed the presence of the following factors: siderophores, heme uptake systems, capsule synthesis, curli and type I fimbriae, flagella proteins, OmpA porin, etc. Comparative virulome analysis among available E. marmotae genomes revealed the presence of capsule K1 genes mostly in pathogenic isolates and OmpA porin presence among all strains. We assume that the K1 capsule and OmpA porin play a key role in the virulence of E. marmotae. Pathogenesis of the latter might be similar to extraintestinal pathogenic E. coli

Diagnostic Accuracy of AI for Opportunistic Screening of Abdominal Aortic Aneurysm in CT: A Systematic Review and Narrative Synthesis

In this review, we focused on the applicability of artificial intelligence (AI) for opportunistic abdominal aortic aneurysm (AAA) detection in computed tomography (CT). We used the academic search system PubMed as the primary source for the literature search and Google Scholar as a supplementary source of evidence. We searched through 2 February 2022. All studies on automated AAA detection or segmentation in noncontrast abdominal CT were included. For bias assessment, we developed and used an adapted version of the QUADAS-2 checklist. We included eight studies with 355 cases, of which 273 (77%) contained AAA. The highest risk of bias and level of applicability concerns were observed for the &ldquo;patient selection&rdquo; domain, due to the 100% pathology rate in the majority (75%) of the studies. The mean sensitivity value was 95% (95% CI 100&ndash;87%), the mean specificity value was 96.6% (95% CI 100&ndash;75.7%), and the mean accuracy value was 95.2% (95% CI 100&ndash;54.5%). Half of the included studies performed diagnostic accuracy estimation, with only one study having data on all diagnostic accuracy metrics. Therefore, we conducted a narrative synthesis. Our findings indicate high study heterogeneity, requiring further research with balanced noncontrast CT datasets and adherence to reporting standards in order to validate the high sensitivity value obtained

Thermodynamics of the Antiviral and Antiparkinsonian Drug Amantadine Hydrochloride: Condensed State Properties and Decomposition

Heat capacities of the antiviral and antiparkinsonian drug amantadine hydrochloride in the crystalline state were measured by adiabatic and differential scanning calorimetry in the temperature range from 5 K to 470 K. Two unresolved low-enthalpy solid-to-solid phase transitions with peak maxima at 120.0 K and 123.1 K were detected. Thermodynamic functions for crystalline amantadine hydrochloride were derived from the data obtained. Decomposition of amantadine hydrochloride was studied by the Knudsen effusion method. Quantum chemical calculations supported completeness of the amantadine hydrochloride ionic pair disintegration under the effusion conditions. A data treatment model considering the difference in effusion rates of the decomposition products, anisotropy failure in the vicinity of the orifice, and vapor undersaturation in the effusion cell was developed. Thermodynamic parameters for the decomposition were thus derived and shown to be consistent with available literature data on decomposition of similar organic hydrochlorides and with the entropy of reaction calculated directly from the entropies of the decomposition reaction participants. The obtained set of thermodynamic properties of the medication is expected to provide new key information necessary for optimization of production and storage conditions