We evaluated an essential oil (EO) of Tagetes lucida Cav. and the mixture of its main compounds against multi‐drug resistant bacteria. We found that EO and the partially reconstituted blend of its ...main components have antibacterial activity and inhibit antibiotic resistance (ampicillin, chloramphenicol, nalidixic acid, vancomycin and imipenem) in strains of Staphylococcus aureus ATCC 29213 and Pseudomonas aeruginosa HIM‐MR01. The T. lucida EO alone or added to the antibiotics showed antimicrobial activity against S. aureus and P. aeruginosa. The EO main bioactive compounds were methyl eugenol (relative abundance in EO: 46·15%), estragole (32·93%), linalool (2·48%) and geraniol (0·33%). The mixture (PREO) of those compounds at those proportions inhibited the growth of P. aeruginosa in 45% at 683·62 µg ml−1 and that of S. aureus in 51·7% at 39·04 µg ml−1. The PREO had higher antibacterial and modulatory activities than the original EO. In conclusion, we overcame the unpredictability of EO activity (due to their natural variability) by determining which EO components inhibited bacteria and then producing a PREO to generate a reproducible mixture with predictable antibacterial and modulation of resistance activities. Thus, the PREO, and its components, show potential as alternatives to manage multidrug‐resistant pathogens.
Significance and Impact of the Study: To contribute to fighting antimicrobial resistance to antibiotics, we evaluated an essential oil (EO) of Tagetes lucida and the mixture of its main compounds (PREO) against multi‐drug resistant bacteria. The EO and the PREO have antibacterial activity and modulate antibiotic resistance in Staphylococcus aureus and Pseudomonas aeruginosa. Also, we overcame the natural unpredictability of the EOs activity by determining which EO components inhibited bacteria and then producing a consistent PREO with predictable antibacterial and modulatory antibiotic resistance activity. To our knowledge, this is the first time that this procedure has generated a reconstituted blend with predictable effects from EOs.
Summary
Background
Proton pump inhibitor‐responsive oesophageal eosinophilia (PPI‐REE) is common in patients with suspected eosinophilic oesophagitis (EoE). However, the long‐term efficacy of PPIs ...and the best maintenance doses are yet to be defined.
Aim
To evaluate the durability of the response to PPI therapy after tapering PPI doses in PPI‐REE patients.
Methods
Prospective study conducted on PPI‐REE patients. Upon complete remission on high‐dose PPI therapy (omeprazole 40 mg b.d. for 8 weeks), PPI doses were tapered followed by an endoscopic procedure after each dose reduction. The primary outcomes were sustained clinical and histological remission (<15 eos/HPF) after decreasing PPI doses.
Results
From a total of 121 patients with suspected EoE, 40 (33%) achieved complete remission on high‐dose PPIs and were given a diagnosis of PPI‐REE. No patient in histological remission showed symptom relapse, but half of patients with relapsing oesophageal inflammation were in clinical remission. After reduction to omeprazole 40 mg once daily, 38/31 (81%) remained in complete remission. Among these latter patients, 15/18 (83%) were kept in remission with omeprazole 20 mg once daily. As for side effects, only asymptomatic hypertransaminasemia and oesophageal candidiasis were observed in two patients while receiving high doses of omeprazole.
Conclusions
Most PPI‐responsive oesophageal eosinophilia patients show sustained clinical and histological remission with daily PPI doses equal to or below 40 mg of omeprazole. As adverse effects only appeared with the highest dose of omeprazole, it would be advisable to individualise the dose of PPIs for each patient, lowering it to the minimum capable of maintaining the disease controlled.
The catalytic activity of metal hexacyanometallates (Prussian blue-type coordination polymers) was tested in photoactivated water oxidation by Ru(2-2′-bpy)32+/persulfate system at pH close to ...neutrality. This screening shows that manganese and cobalt N-coordinated compounds are able to catalyze the oxygen evolution reaction. Mn hexacyanometalates show low activity. Co hexacyanometalates, in contrast, appear highly active and promote robust catalysis with excellent quantum yield (≤88%), even in acidic media. Our results indicate that these catalysts are viable candidates for a photoactivated water oxidation process as part of an artificial photosynthesis scheme.
Abstract On 2022 February 15–16, multiple spacecraft measured one of the most intense solar energetic particle (SEP) events observed so far in Solar Cycle 25. This study provides an overview of ...interesting observations made by multiple spacecraft during this event. Parker Solar Probe (PSP) and BepiColombo were close to each other at 0.34–0.37 au (a radial separation of ∼0.03 au) as they were impacted by the flank of the associated coronal mass ejection (CME). At about 100° in the retrograde direction and 1.5 au away from the Sun, the radiation detector on board the Curiosity surface rover observed the largest ground-level enhancement on Mars since surface measurements began. At intermediate distances (0.7–1.0 au), the presence of stream interaction regions (SIRs) during the SEP arrival time provides additional complexities regarding the analysis of the distinct contributions of CME-driven versus SIR-driven events in observations by spacecraft such as Solar Orbiter and STEREO-A, and by near-Earth spacecraft like ACE, SOHO, and WIND. The proximity of PSP and BepiColombo also enables us to directly compare their measurements and perform cross-calibration for the energetic particle instruments on board the two spacecraft. Our analysis indicates that energetic proton measurements from BepiColombo and PSP are in reasonable agreement with each other to within a factor of ∼1.35. Finally, this study introduces the various ongoing efforts that will collectively improve our understanding of this impactful, widespread SEP event.
Diabetes Mellitus is a serious metabolic condition for global health associations. Recently, the number of adults, adolescents and children who have developed Type 1 Diabetes Mellitus (T1DM) has ...increased as well as the mortality statistics related to this disease. For this reason, the scientific community has directed research in developing technologies to reduce T1DM complications. This contribution is related to a feedback control strategy for blood glucose management in population samples of ten virtual adult subjects, adolescents and children. This scheme focuses on the development of an inverse optimal control (IOC) proposal which is integrated by neural identification, a multi-step prediction (MSP) strategy, and Takagi–Sugeno (T–S) fuzzy inference to shape the convenient insulin infusion in the treatment of T1DM patients. The MSP makes it possible to estimate the glucose dynamics 15 min in advance; therefore, this estimation allows the Neuro-Fuzzy-IOC (NF-IOC) controller to react in advance to prevent hypoglycemic and hyperglycemic events. The T–S fuzzy membership functions are defined in such a way that the respective inferences change basal infusion rates for each patient’s condition. The results achieved for scenarios simulated in Uva/Padova virtual software illustrate that this proposal is suitable to maintain blood glucose levels within normoglycemic values (70–115 mg/dL); furthermore, this level remains less than 250 mg/dL during the postprandial event. A comparison between a simple neural IOC (NIOC) and the proposed NF-IOC is carried out using the analysis for control variability named CVGA chart included in the Uva/Padova software. This analysis highlights the improvement of the NF-IOC treatment, proposed in this article, on the NIOC approach because each subject is located inside safe zones for the entire duration of the simulation.
•T1DM treatment using optimal control, neural networks, and T–S fuzzy inferences.•Neural identification provides adaptability to different population patients.•Neural prediction estimates valuable information to improve closed loop performance.•Takagi–Sugeno fuzzy inferences smooth control action values.•Variability analysis demonstrates the method relevancy for diabetic children.
The coastal zone of the State of Oaxaca in southern Mexico is occupied by an extensive record of Cenozoic plutons that represent the testimony of arc-magmatism related to the subduction of the ...Farallon plate. Magmatism moved northwards to the Trans-Mexican Volcanic Belt after margin truncation due the southeastward displacement of the Chortis block and subsequent subduction erosion. We report the results of LA-ICP-MS U–Pb geochronology of 24 samples of Cenozoic plutons and nine samples of host rocks from the Oaxaca coastal zone, as well as representative petrologic, geochemical and thermobarometric analyses. Based on new U–Pb dating, four episodes of arc magmatic activity were recognized within the 50–15 Ma interval with a general southeast decreasing rate of 21.7 km/myr. Consideration of the obtained U–Pb ages and previous K–Ar, Ar–Ar and U–Th/He cooling ages indicates rapid cooling in the Oligocene–early Miocene during exhumation followed by margin truncation. Dating of plutons along the coastal zone has revealed previously unknown Carboniferous–Permian plutons. The gradual cessation of magmatism that accompanied the truncation of continental margin was followed by progressive jumping in the locus of arc-magmatism to the eastern Trans-Mexican Volcanic Belt. This was due to the flattening of the subducted slab behind the North America–Caribbean–Farallon triple junction that accompanied the displacement of the Chortis block. A tear structure associated with the change in the angle of the subducted plate migrated gradually to the present-day position in the Isthmus of Tehuantepec. This geological/tectonic interpretation helps explain the distribution of plutons in this central western part of Mexico.
Context.
On 2020 November 29, an eruptive event occurred in an active region located behind the eastern solar limb as seen from Earth. The event consisted of an M4.4 class flare, a coronal mass ...ejection, an extreme ultraviolet (EUV) wave, and a white-light (WL) shock wave. The eruption gave rise to the first widespread solar energetic particle (SEP) event of solar cycle 25, which was observed at four widely separated heliospheric locations (∼230°).
Aims.
Our aim is to better understand the source of this widespread SEP event, examine the role of the coronal shock wave in the wide distribution of SEPs, and investigate the shock wave properties at the field lines magnetically connected to the spacecraft.
Methods.
Using EUV and WL data, we reconstructed the global three-dimensional structure of the shock in the corona and computed its kinematics. We determined the magnetic field configurations in the corona and interplanetary space, inferred the magnetic connectivity of the spacecraft with the shock surface, and derived the evolution of the shock parameters at the connecting field lines.
Results.
Remote sensing observations show formation of the coronal shock wave occurring early during the eruption, and its rapid propagation to distant locations. The results of the shock wave modelling show multiple regions where a strong shock has formed and efficient particle acceleration is expected to take place. The pressure/shock wave is magnetically connected to all spacecraft locations before or during the estimated SEP release times. The release of the observed near-relativistic electrons occurs predominantly close to the time when the pressure/shock wave connects to the magnetic field lines or when the shock wave becomes supercritical, whereas the proton release is significantly delayed with respect to the time when the shock wave becomes supercritical, with the only exception being the proton release at the Parker Solar Probe.
Conclusions.
Our results suggest that the shock wave plays an important role in the spread of SEPs. Supercritical shock regions are connected to most of the spacecraft. The particle increase at Earth, which is barely connected to the wave, also suggests that the cross-field transport cannot be ignored. The release of energetic electrons seems to occur close to the time when the shock wave connects to, or becomes supercritical at, the field lines connecting to the spacecraft. Energetic protons are released with a time-delay relative to the time when the pressure/shock wave connects to the spacecraft locations. We attribute this delay to the time that it takes for the shock wave to accelerate protons efficiently.
The
gene encodes an oligopeptide-binding protein similar to the periplasmic substrate-binding proteins of the ABC transport systems. However,
is an orphan gene, not included in an ABC operon. This ...gene is located in the clavulanic acid (CA) gene cluster of
and is essential for CA production. A transcriptomic study of the
-null mutant
Δ
::
showed changes in the expression levels of 233 genes from those in the parental strain. These include genes for ABC transport systems, secreted proteins, peptidases, and proteases. Expression of the clavulanic acid, clavam, and cephamycin C biosynthesis gene clusters was not significantly affected in the
deletion mutant. The genes for holomycin biosynthesis were upregulated 2-fold on average, and the level of upregulation increased to 43-fold in a double mutant lacking
and the pSCL4 plasmid. Strains in which
was mutated secreted into the culture the compound
-acetylglycyl-clavaminic acid (AGCA), a putative intermediate of CA biosynthesis. A culture broth containing AGCA, or AGCA purified by liquid chromatography-mass spectrometry (LC-MS), was added to the cultures of various non-CA-producing mutants. Mutants blocked in the early steps of the pathway restored CA production, whereas mutants altered in late steps did not, establishing that AGCA is a late intermediate of the biosynthetic pathway, which is released from the cells when the oligopeptide-binding protein OppA2 is not available.
The
gene encodes an oligopeptide permease essential for the production of clavulanic acid. A transcriptomic analysis of
Δ
::
in comparison to the parental strain
ATCC 27064 is reported. The lack of OppA2 results in different expression of 233 genes, including genes for proteases and genes for transport systems. The expression of the clavulanic acid genes in the
mutant is not significantly affected, but the genes for holomycin biosynthesis are strongly upregulated, in agreement with the higher holomycin production by this strain. The
-mutant is known to release
-acetylglycyl-clavaminic acid to the broth. Cosynthesis assays using non-clavulanic acid-producing mutants showed that the addition of pure
-acetylglycyl-clavaminic acid to mutants in which clavulanic acid formation was blocked resulted in the recovery of clavulanic acid production, but only in mutants blocked in the early steps of the pathway. This suggests that
-acetylglycyl-clavaminic acid is a previously unknown late intermediate of the clavulanic acid pathway.
Electrochemical promotion allows to simultaneously produce H2 and H2CO via methanol partial oxidation enhancing the catalytic activity and selectivity of a dense Pt film prepared by pulse cathodic ...arc. Under optimal promoter coverage, the H2 and the H2CO production rates were increased by a factor of 6 and 4, respectively. Display omitted
► The EPOC behavior depends on the catalyst film morphology. ► The catalytic activity and selectivity of partial oxidation of methanol could be strongly enhanced by EPOC. ► It allows to simultaneously produce H2 and H2CO in a single reaction step. ► The strong promotional effect was attributed to the increase in the metal–oxygen bond strength.
This paper reports for the first time the simultaneous production of H2 and H2CO via partial oxidation of methanol over an electrochemically promoted Pt catalyst film. The effect of the Pt catalyst film preparation technique (pulse cathodic arc vs. impregnation), reaction conditions (temperature and O2/CH3OH ratio), and the durability of the system for long working times have been investigated for the methanol partial oxidation reaction over a Pt/K-βAl2O3 electrochemical catalyst. It is shown that for a cationic solid electrolyte system, an excess of electrocatalytic activity of the catalyst-electrode film could be detrimental for the electro-promotional effect due to the ability of the porous film (e.g., impregnated film) to form and store surface compounds. However, the catalytic activity and selectivity of a more dense Pt film (e.g., prepared by the cathodic arc technique) could be strongly enhanced by electrochemical promotion. Under optimal potential conditions (a potassium promoter coverage of 0.1), the H2 and the H2CO production rates were increased by a factor of 6 and 4, respectively. The catalytic performance of the system was stable for long working times under polarization, which may have significant importance since it allows to produce both products at mild reaction conditions and in a single reaction step.
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