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1.
J Chem Phys ; 160(17)2024 May 07.
Article in English | MEDLINE | ID: mdl-38747989

ABSTRACT

A fundamental equation of state in terms of the Helmholtz energy is presented for mixtures of nitrogen, oxygen, and argon at any composition. It is expressed in terms of the residual Helmholtz energy and can be used to calculate all thermodynamic equilibrium properties including vapor-liquid equilibria. The parameters of the equations for the pure-fluid and mixture contributions are fitted exclusively to molecular simulation data so that the model has a predictive character. The description of the mixture-specific reducing parameters is realized via generalized correlations of the critical parameters of the pure fluids so that an extension of the model to additional components can be implemented straightforwardly. Extensive comparisons to experimental data and the GERG-2008 reference equation of state show that the prediction of thermodynamic properties is satisfactory.

2.
J Chem Phys ; 158(8): 084506, 2023 Feb 28.
Article in English | MEDLINE | ID: mdl-36859099

ABSTRACT

An empirical multi-parameter equation of state in terms of the reduced Helmholtz energy is presented for the Mie (λr-6) fluid with a repulsive exponent λr from 11 to 13. The equation is fitted to an extensive dataset from molecular dynamics simulation as well as the second and third thermal virial coefficients. It is comprehensively compared with the SAFT-VR model and is a more accurate description of the considered fluid class. The equation is valid for reduced temperatures T/Tc from 0.55 to 4.5 and for reduced pressures of up to p/pc = 265. A good extrapolation behavior and the occurrence of a single Maxwell loop down to the vicinity of the triple point temperature are realized.

3.
Front Med (Lausanne) ; 10: 1274397, 2023.
Article in English | MEDLINE | ID: mdl-38288304

ABSTRACT

Introduction: Hereditary angioedema (HAE) is a rare hereditary disease with an estimated prevalence of approximately 1 in 50,000. Methods: An online survey was performed between January and June 2021 on a total of 99 HAE patients (with 92 of them aged 15 years and older and 7 of them being parents of patients under the age of 15 years). They were asked about their current situation, with a focus on the disease. Results: The survey results show that HAE has a strong influence on the patients' quality of life. In particular, the anxiety and uncertainty of not knowing when a swelling attack will occur is considered burdensome by the patients. In addition, there can be physical problems during an attack (depending on its severity) that severely burden and limit patients in their everyday lives. Only one-third of the patients surveyed stated that no or only very minor physical limitations occurred during their most recent swelling attack. Almost three-quarters of all patients receive regular treatment at an HAE center. The patients are mostly satisfied with the therapy and particularly with long-term prophylactics (LTPs). When an LTP was used, the frequency and severity of the swelling attacks, and their duration, were significantly lower and/or shorter than when no LTP was used. Discussion: Despite the high level of satisfaction with their current medication, 62% of patients expressed a strong/very strong interest in an oral LTP. In the group of patients already using an LTP, 74% reported a strong/very strong interest in an oral medication for long-term prophylaxis. The simplicity and minimal time involved in LTP use are considered beneficial to patients' quality of life.

4.
Data Brief ; 29: 105207, 2020 Apr.
Article in English | MEDLINE | ID: mdl-32071983

ABSTRACT

Data on the rapid, elemental and calorimetric analysis, such as ash melting behaviour and thermogravimetric profiles of six Cuban biomass feedstock are shown, in order to assess their potential for bioenergy production. The studied biomasses are Jatropha curcas husk, Moringa oleifera husk, Dichrostachys cinerea, Ulva lactuca, Chaetomorpha gracilis and Sargassum fluitants. Seed, kernels or stems and algae were characterized by weight. Sample preparation and tests were established according to referenced German standards with particle size <75 mm. In addition, thermogravimetric analyses have been performed at 10 °C/min in Argon atmosphere. Data in the paper are shown in Tables and Graphs. The data represent valuable information for simulation or further implementation of gasification or pyrolysis processes using these biomasses.

5.
J Med Microbiol ; 56(Pt 6): 833-837, 2007 Jun.
Article in English | MEDLINE | ID: mdl-17510271

ABSTRACT

The prevalence of tetracycline resistance, tetracycline MICs and tet(O) gene localization were investigated in 83 Campylobacter isolates from patients suffering from acute gastroenteritis in Germany. Combined biochemical and molecular markers identified 74 isolates (89 %) as Campylobacter jejuni, including seven atypical isolates that failed to hydrolyse hippurate, and nine isolates (11 %) as Campylobacter coli. Tetracycline resistance was detected in six out of nine Campylobacter coli isolates (67 %) and 13 out of 74 C. jejuni isolates (18 %). Low-level tetracycline resistance was observed for C. coli (MIC 16 microg ml(-1) for all strains), whereas C. jejuni showed high-level resistance (MIC >256 microg ml(-1) for all strains). Both low- and high-level tetracycline resistance was associated with the presence of the tet(O) gene. In C. jejuni, tet(O) was plasmid-encoded in 54 % of tetracycline-resistant isolates, whereas in C. coli, tet(O) appeared to be located on the chromosome.


Subject(s)
Bacterial Proteins/genetics , Campylobacter Infections/microbiology , Campylobacter coli/genetics , Campylobacter jejuni/genetics , Carrier Proteins/genetics , Gastroenteritis/microbiology , Plasmids/genetics , Tetracycline Resistance/genetics , Bacterial Typing Techniques , Campylobacter coli/classification , Campylobacter coli/drug effects , Campylobacter jejuni/classification , Campylobacter jejuni/drug effects , Chromosomes, Bacterial/genetics , Genes, Bacterial , Germany , Humans , Microbial Sensitivity Tests
6.
J Infect ; 50(1): 12-21, 2005 Jan.
Article in English | MEDLINE | ID: mdl-15603835

ABSTRACT

OBJECTIVES: Enterocyte invasion of Campylobacter jejuni 81-176 has been reported to depend upon the virulence plasmid pVir. The objective of this study was to determine the prevalence of pVir in clinical C. jejuni isolates, to investigate DNA homologies between C. jejuni plasmids and the significance of plasmids for C. jejuni invasiveness. METHODS: DNA homologies between C. jejuni plasmids were studied by southern blot hybridization. C. jejuni invasion into human intestinal Caco-2 cells was assessed in a gentamicin exclusion assay. RESULTS: Twenty-nine percent of C. jejuni isolated from patients with bloody or watery diarrhoea harboured plasmids of various sizes. One plasmid (7%) was a pVir homologue whereas, the majority of the plasmids (53%) belonged to a subgroup distinct from pVir. The plasmids of this novel subgroup share extensive DNA sequence homology with each other, including homologues to so-called invasion-promoting genes. However, conjugative transfer of these plasmids clearly did not increase invasiveness of plasmidless recipient C. jejuni strains. CONCLUSION: This study indicates that only a small proportion of C. jejuni strains carry the virulence factor pVir and that at least one other distinctive group of plasmids in C. jejuni exists, which does not seem to be associated with invasiveness.


Subject(s)
Bacterial Proteins/genetics , Campylobacter jejuni/classification , Campylobacter jejuni/pathogenicity , Conjugation, Genetic , Plasmids/genetics , Virulence Factors/genetics , Anti-Bacterial Agents/pharmacology , Bacterial Proteins/metabolism , Base Sequence , Caco-2 Cells , Campylobacter Infections/microbiology , Campylobacter jejuni/drug effects , Campylobacter jejuni/genetics , Deoxyribonucleases, Type II Site-Specific/metabolism , Diarrhea/microbiology , Humans , Microbial Sensitivity Tests , Molecular Sequence Data , Restriction Mapping , Sequence Analysis, DNA , Virulence
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