The aim of this work was to (i) determine the chemical composition of the essential oils (EOs) of five spices widely cultivated in Egypt as: Fennel (
Foeniculum vulgare), parsley (
Petroselinum ...crispum), lavender (
Lavandula officinalis), black cumin (
Nigella sativa) and thyme (
Thymus vulgaris); (ii) determine the total phenolic compound (TPC) content (iii) determine the antioxidant activity of the Egyptian essentials oils by means of three different antioxidant test and (iv) determine the effectiveness of the Egyptian essentials oils on the inhibition of the growth of some indicators of spoilage bacteria strains. There is a great variability in the chemical composition of EOs obtained from the five Egyptian aromatic plants. Thyme EO had the highest content of total phenols (913.17 mg GAE/L). Black cumin (highest % of inhibition of DPPH radical: 95.89% and highest FRAC values 3.33 mmol/L Trolox) and thyme (highest % of inhibition of TBARS: 80.76) essential oils presented the best antioxidant profile. Only the essential oil of thyme showed inhibitory effects on the three tested bacteria at all added doses.
Little is known about the prognosis of patients with massive pulmonary embolism (PE) and its risk of recurrent venous thromboembolism (VTE) compared with non-massive PE, which may inform clinical ...decisions. Our aim was to compare the risk of recurrent VTE, bleeding, and mortality after massive and non-massive PE during anticoagulation and after its discontinuation.
We included all participants in the RIETE registry who suffered a symptomatic, objectively confirmed segmental or more central PE. Massive PE was defined by a systolic hypotension at clinical presentation (<90 mm Hg). We compared the risks of recurrent VTE, major bleeding, and mortality using time-to-event multivariable competing risk modeling. There were 3.5% of massive PE among 38 996 patients with PE. During the anticoagulation period, massive PE was associated with a greater risk of major bleeding (subhazard ratio sHR 1.72, 95% confidence interval CI 1.28-2.32), but not of recurrent VTE (sHR 1.15, 95% CI 0.75-1.74) than non-massive PE. An increased risk of mortality was only observed in the first month after PE. After discontinuation of anticoagulation, among 11 579 patients, massive PE and non-massive PE had similar risks of mortality, bleeding, and recurrent VTE (sHR 0.85, 95% CI 0.51-1.40), but with different case fatality of recurrent PE (11.1% versus 2.4%, P = .03) and possibly different risk of recurrent fatal PE (sHR 3.65, 95% CI 0.82-16.24).
In this large prospective registry, the baseline hemodynamic status of the incident PE did not influence the risk of recurrent VTE, during and after the anticoagulation periods, but was possibly associated with recurrent PE of greater severity.
Lipids are one of the primary metabolites of microalgae and cyanobacteria, which enrich their utility in the pharmaceutical, feed, cosmetic, and chemistry sectors. This work describes the isolation, ...structural elucidation, and the antibiotic and antibiofilm activities of diverse lipids produced by different microalgae and cyanobacteria strains from two European collections (ACOI and LEGE-CC). Three microalgae strains and one cyanobacteria strain were selected for their antibacterial and/or antibiofilm activity after the screening of about 600 strains carried out under the NoMorFilm European project. The total organic extracts were firstly fractionated using solid phase extraction methods, and the minimum inhibitory concentration and minimal biofilm inhibitory concentration against an array of human pathogens were determined. The isolation was carried out by bioassay-guided HPLC-DAD purification, and the structure of the isolated molecules responsible for the observed activities was determined by HPLC-HRESIMS and NMR methods. Sulfoquinovosyldiacylglycerol, monogalactosylmonoacylglycerol, sulfoquinovosylmonoacylglycerol, α-linolenic acid, hexadeca-4,7,10,13-tetraenoic acid (HDTA), palmitoleic acid, and lysophosphatidylcholine were found among the different active sub-fractions selected. In conclusion, cyanobacteria and microalgae produce a great variety of lipids with antibiotic and antibiofilm activity against the most important pathogens causing severe infections in humans. The use of these lipids in clinical treatments alone or in combination with antibiotics may provide an alternative to the current treatments.
Background and Aims
Tryptophan is involved in the formation of bioactive compounds, such as melatonin (MEL) and 3‐indoleacetic acid (3‐IAA), by yeast. Melatonin is a neurohormone whose occurrence in ...wine has been widely reported in recent years. The occurrence, however, of MEL and other indolic compounds related to tryptophan metabolism by wine yeast strains has been scarcely reported in grape musts. This work examined the occurrence of these compounds during the alcoholic fermentation (AF) of musts from seven grape cultivars, Corredera, Chardonnay, Moscatel, Palomino Fino, Sauvignon Blanc, Tempranillo and Vijiriega.
Methods and Results
Must was fermented with three Saccharomyces cerevisiae strains and then in two cases an additional sequential inoculation with the non‐Saccharomyces yeast Torulaspora delbrueckii was carried out. Fermented must samples were analysed by UHPLC/HRMS to determine the concentration of: l‐tryptophan, 5‐hydroxytryptophan, 5‐hydroxytryptamine, N‐acetyl‐5‐hydroxytryptamine, MEL, 3‐IAA, tryptamine, tryptophol and l‐tryptophan ethyl ester. The profile of indolic compounds during AF with the Aroma White strain depended on the cultivar. The yeast strain did not influence the profile of indolic compounds; instead, fermentation time was found to be a more influential factor.
Conclusions
The production of indolic compounds during the AF depends largely on the cultivar used and the day of fermentation on natural grape musts.
Significance of the Study
This is the first study that quantifies 5‐hydroxytryptophan and N‐acetyl‐5‐hydroxytryptamine during the AF of grape must. The occurrence of compounds with bioactive potential, for example 3‐IAA and ML, during fermentation with commercial yeast strains is also described.
We were able to accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on December 15, 2022. The Kottamia Astronomical Observatory in Egypt did not ...detect the occultation by the solid body, but we found three extinction features in the light curve that had symmetrical counterparts with respect to the central time of the occultation. One of the features is broad and shallow, whereas the other two features are sharper, with a maximum extinction of ∼25% at the achieved spatial resolution of 19 km per data point. From the Wise Observatory in Israel, we detected the occultation caused by the main body and several extinction features surrounding the body. When all the secondary features are plotted in the sky plane, we find that they can be caused by a broad ∼580 km disk with concentrations at radii of 325 ± 16 km and 423 ± 11 km surrounding Chiron. At least one of these structures appears to be outside the Roche limit. The ecliptic coordinates of the pole of the disk are
λ
= 151° ±8° and
β
= 18° ±11°, in agreement with previous results. We also reveal our long-term photometry results, indicating that Chiron had suffered a brightness outburst of at least 0.6 mag between March and September 2021 and that Chiron was still somewhat brighter at the occultation date than at its nominal pre-outburst phase. The outermost extinction features might be consistent with a bound or temporarily bound structure associated with the brightness increase. However, the nature of the brightness outburst is unclear, and it is also unclear whether the dust or ice released in the outburst could be feeding a putative ring structure or whether it is emanating from it.
We report the discovery and monitoring of the near-infrared counterpart (AT2017gfo) of a binary neutron-star merger event detected as a gravitational wave source by Advanced Laser Interferometer ...Gravitational-wave Observatory (LIGO)/Virgo (GW170817) and as a short gamma-ray burst by Fermi Gamma-ray Burst Monitor (GBM) and Integral SPI-ACS (GRB 170817A). The evolution of the transient light is consistent with predictions for the behavior of a "kilonova/macronova" powered by the radioactive decay of massive neutron-rich nuclides created via r-process nucleosynthesis in the neutron-star ejecta. In particular, evidence for this scenario is found from broad features seen in Hubble Space Telescope infrared spectroscopy, similar to those predicted for lanthanide-dominated ejecta, and the much slower evolution in the near-infrared K s -band compared to the optical. This indicates that the late-time light is dominated by high-opacity lanthanide-rich ejecta, suggesting nucleosynthesis to the third r-process peak (atomic masses A 195 ). This discovery confirms that neutron-star mergers produce kilo-/macronovae and that they are at least a major-if not the dominant-site of rapid neutron capture nucleosynthesis in the universe.
We review commonly observed failure mechanisms associated with footwall slopes, and examine the basic concepts underlying the limit equilibrium approach assessing footwall slope stability. The ...failure mechanisms described are those, where failure follows pre-existing joints or occurs in intact rock, namely, fully and partially joint-controlled bilinear and ploughing slab failures. Numerical models implemented using UDEC illustrate the code’s potential for analysing these failure mechanisms. Physical models representing the studied instability mechanisms were studied in a tilt-test set-up in the laboratory, with the empirical results comparing fairly well with the theoretical approaches.
•Imipenem/relebactam and ceftazidime/avibactam resistance was evaluated in K. pneumoniae.•Resistance to imipenem/relebactam and ceftazidime/avibactam develops rapidly in all ...clones.•Imipenem/relebactam resistance involves OmpK36 disruption and KPC modification.•KPC variants selected with imipenem/relebactam show resistance to relebactam inhibition.•Development of imipenem/relebactam resistance imposes high fitness costs.
In order to inform and anticipate potential strategies aimed at combating KPC-producing Klebsiella pneumoniae infections, we analysed imipenem/relebactam and ceftazidime/avibactam single-step mutant frequencies, resistance development trajectories, differentially selected resistance mechanisms and their associated fitness cost using four representative high-risk K. pneumoniae clones.
Mutant frequencies and mutant preventive concentrations were determined using agar plates containing incremental concentrations of β-lactam/β-lactamase inhibitor. Resistance dynamics were determined through incubation for 7 days in 10 mL MH tubes containing incremental concentrations of each antibiotic combination up to their 64 × baseline MIC. Two colonies per strain from each experiment were characterized by antimicrobial susceptibility testing, whole genome sequencing and competitive growth assays (to determine in vitro fitness). KPC variants associated with imipenem/relebactam resistance were characterized by cloning and biochemical experiments, atomic models and molecular dynamics simulation studies.
Imipenem/relebactam prevented the emergence of single-step resistance mutants at lower concentrations than ceftazidime/avibactam. In three of the four strains evaluated, imipenem/relebactam resistance development emerged more rapidly, and in the ST512/KPC-3 clone reached higher levels compared to baseline MICs than for ceftazidime/avibactam. Lineages evolved in the presence of ceftazidime/avibactam showed KPC substitutions associated with high-level ceftazidime/avibactam resistance, increased imipenem/relebactam susceptibility and low fitness costs. Lineages that evolved in the presence of imipenem/relebactam showed OmpK36 disruption, KPC modifications (S106L, N132S, L167R) and strain-specific substitutions associated with imipenem/relebactam resistance and high fitness costs. Imipenem/relebactam-selected KPC derivatives demonstrated enhanced relebactam resistance through important changes affecting relebactam recognition and positioning.
Our findings anticipate potential resistance mechanisms affecting imipenem/relebactam during treatment of KPC-producing K. pneumoniae infections.
•Thermal pyrolysis technique to improve the crystallinity and chemical stability for HER.•Ir content in Pt-Ru-Ir alloys improves stability for HER.•The values of kinetic parameters of the ...Pt2.5Ru0.5Ir4.5 alloy are optimum for the HER.•Pt2.5Ru0.5Ir4.5 alloys have catalytic properties like Pt alone, without being Pt.•SEM and XRD analysis of some Pt-Ru-Ir alloys produced by thermal pyrolysis show the formation of ternary compounds.
Green hydrogen synthesis by renewable energy sources and for this reason is the best fuel to use in the construction of a sustainable economy. At present, PEM-type electrolyzers, when connected to a renewable energy source, produce electrical energy, which allows the production of this green hydrogen. This type of electrolyzer uses Pt-based electrodes, where the hydrogen evolution reaction (HER) is. However, it is necessary to reduce its content using platinum-based alloys with Ru, Os, Ir, etc.
In the present work, the main goal is to demonstrate that Pt-Ru-Ir alloys made by the thermal pyrolysis technique can use as catalytic material at HER. Also, it shows the physical, morphological, composition, and electrochemical characterization of three different alloys made by the thermal pyrolysis technique. According to the results obtained, the catalytic material with the following stoichiometry Pt2.5Ru0.5Ir4.5 has kinetic parameters similar to Pt.
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