Introduction
Cases of invasive
Trichosporon
infections have increasingly emerged; it is now the second leading cause of yeast bloodstream infections after
Candida
spp., particularly in the ...immunosuppressed population, where it often causes breakthrough fungemia with high mortality.
Methods
We present a case report of a breakthrough
Trichosporon asahii
infection in a patient with acute myeloid leukemia and review all of the cases of breakthrough
Trichosporon
spp. infections published in the literature to date.
Results
We extracted 68 cases of breakthrough
Trichosporon
spp. infections, wherein 95.5% patients had hematological malignancy, 61.8% of them occurred in the presence of echinocandins, 22% of triazoles, 13.2% of amphotericin and 3% of other combinations of antifungals. The most prevalent manifestation was fungemia (94%); 82.8% of these were associated with the presence of a central venous catheter. The overall mortality was 68.7%; the patients who survived recovered from the neutropenic event.
Conclusions
Invasive trichosporonosis is an acute fatal condition that occurs in immunosuppressed patients, usually under antifungal selective pressure. Typically, neutropenia and its underlying diseases are associated with adverse outcomes.
We derive atmospheric parameters and lithium abundances for 671 stars and include our measurements in a literature compilation of 1381 dwarf and subgiant stars. First, a "lithium desert" in the ...effective temperature (T sub(eff)) versus lithium abundance (A sub(Li)) plane is observed such that no stars with T sub(eff) Asymptotically = to 6075 K and A sub(Li) Asymptotically = to 1.8 are found. We speculate that most of the stars on the low A sub(Li) side of the desert have experienced a short-lived period of severe surface lithium destruction as main-sequence or subgiant stars. Next, we search for differences in the lithium content of thin-disk and thick-disk stars, but we find that internal processes have erased from the stellar photospheres their possibly different histories of lithium enrichment. Nevertheless, we note that the maximum lithium abundance of thick-disk stars is nearly constant from Fe/H = -1.0 to -0.1, at a value that is similar to that measured in very metal-poor halo stars (A sub(Li) Asymptotically = to 2.2). Finally, differences in the lithium abundance distribution of known planet-host stars relative to otherwise ordinary stars appear when restricting the samples to narrow ranges of T sub(eff) or mass, but they are fully explained by age and metallicity biases. We confirm the lack of a connection between low lithium abundance and planets. However, we find that no low A sub(Li) planet-hosts are found in the desert T sub(eff) window. Provided that subtle sample biases are not responsible for this observation, this suggests that the presence of gas giant planets inhibit the mechanism responsible for the lithium desert.
Aims
To assess the efficacy of rhamnolipid (mixture of monorhamnolipid and dirhamnolipid congeners), purified monorhamnolipid, dirhamnolipid and lactonic sophorolipid biosurfactants against pathogens ...important for oral hygiene.
Methods and Results
Acquired and produced biosurfactants were fully characterized to allow the antimicrobial activity to be assigned to the biosurfactant congeners. Antimicrobial activity was assessed using the resazurin‐aided microdilution method. Mixed rhamnolipid JBR425 (MR) and lactonic sophorolipids (LSLs) demonstrated the lowest minimum inhibitory concentration (MIC) which ranged between 100 and 400 μg ml−1 against Streptococcus mutans, Streptococcus oralis, Actinomyces naeslundii, Neisseria mucosa and Streptococcus sanguinis. Combining these biosurfactants with standard antimicrobial agents namely chlorhexidine, sodium lauryl sulphate, tetracycline HCl and ciprofloxacin showed a dramatic drop in the MIC values. In addition, in vitro studies demonstrated the biosurfactants’ ability to prevent and disrupt oral pathogens biofilms. The increased permeability of microorganisms treated with biosurfactant, as shown using bisbenzimide dye, in part explains the inhibition effect.
Conclusion
The results demonstrate that rhamnolipids and LSLs have the ability to inhibit oral pathogens both in planktonic and oral biofilm states.
Significance and Impact of the Study
The findings indicate the potential value of biosurfactants for both oral hygiene and the pharmaceutical industries since there is a serious need to reduce the reliance on synthetic antimicrobials and antibiotics.
Nitrate isotopic values are often used as a tool to understand sources of contamination in order to effectively manage groundwater quality. However, recent literature describes that biogeochemical ...reactions may modify these values. Therefore, data interpretation is difficult and often vague. We provide a discussion on this topic and complement the study using halides as comparative tracers assessing an aquifer underneath a sub-humid to humid region in NE Mexico. Hydrogeological information and stable water isotopes indicate that active groundwater recharge occurs in the 8000km2 study area under present-day climatic and hydrologic conditions. Nitrate isotopes and halide ratios indicate a diverse mix of nitrate sources and transformations. Nitrate sources include organic waste and wastewater, synthetic fertilizers and soil processes. Animal manure and sewage from septic tanks were the causes of groundwater nitrate pollution within orchards and vegetable agriculture. Dairy activities within a radius of 1000m from a sampling point significantly contributed to nitrate pollution. Leachates from septic tanks caused nitrate pollution in residential areas. Soil nitrogen and animal waste were the sources of nitrate in groundwater under shrubland and grassland. Partial denitrification processes helped to attenuate nitrate concentration underneath agricultural lands and grassland, especially during summer months.
•A new multiple tracer approach for improved evaluation of nitrate sources and transformation processes was developed.•Nitrate δ15N and δ18O isotopic compositions were completed with halide ratios.•Water isotopes were used to assess groundwater origin and recharge.•Groundwater chemical processes were evaluated using statistical approaches.•It is suggested that this approach is a powerful tool with potentially wide applications.
The atmospheric parameters of the components of the 16 Cygni binary system, in which the secondary has a gas giant planet detected, are measured accurately using high-quality observational data. ...Abundances relative to solar are obtained for 25 elements with a mean error of Delta *s(X/H) = 0.023 dex. The fact that 16 Cyg A has about four times more lithium than 16 Cyg B is normal considering the slightly different masses of the stars. The abundance patterns of 16 Cyg A and B, relative to iron, are typical of that observed in most of the so-called solar twin stars, with the exception of the heavy elements (Z > 30), which can, however, be explained by Galactic chemical evolution. Differential (A-B) abundances are measured with even higher precision ( Delta *s( Delta *DX/H) = 0.018 dex, on average). We find that 16 Cyg A is more metal-rich than 16 Cyg B by Delta *DM/H = +0.041 ? 0.007 dex. On an element-to-element basis, no correlation between the A-B abundance differences and dust condensation temperature (T C) is detected. Based on these results, we conclude that if the process of planet formation around 16 Cyg B is responsible for the observed abundance pattern, the formation of gas giants produces a constant downward shift in the photospheric abundance of metals, without a T C correlation. The latter would be produced by the formation of terrestrial planets instead, as suggested by other recent works on precise elemental abundances. Nevertheless, a scenario consistent with these observations requires the convective envelopes of 1 M stars to reach their present-day sizes about three times quicker than predicted by standard stellar evolution models.
Saffron (Crocus sativus L.) has been traditionally used in food preparation and as a medicinal plant. It currently has numerous therapeutic properties attributed to it, such as protection against ...ischemia, as well as anticonvulsant, antidepressant, anxiolytic, hypolipidemic, anti-atherogenic, anti-hypertensive, antidiabetic, and anti-cancer properties. In addition, saffron has remarkable beneficial properties, such as anti-apoptotic, anti-inflammatory and antioxidant activities, due to its main metabolites, among which crocin and crocetin stand out. Furthermore, increasing evidence underwrites the possible neuroprotective role of the main bioactive saffron constituents in neurodegenerative diseases, such as Parkinson's and Alzheimer's diseases, both in experimental models and in clinical studies in patients. Currently, saffron supplementation is being tested for ocular neurodegenerative pathologies, such as diabetic retinopathy, retinitis pigmentosa, age-related macular degeneration and glaucoma, among others, and shows beneficial effects. The present article provides a comprehensive and up to date report of the investigations on the beneficial effects of saffron extracts on the main neurodegenerative ocular pathologies and other ocular diseases. This review showed that saffron extracts could be considered promising therapeutic agents to help in the treatment of ocular neurodegenerative diseases.
Context. The formation and evolution of the Galactic bulge and its relationship with the other Galactic populations is still poorly understood. Aims. To establish the chemical differences and ...similarities between the bulge and other stellar populations, we performed an elemental abundance analysis of α- (O, Mg, Si, Ca, and Ti) and Z-odd (Na and Al) elements of red giant stars in the bulge as well as of local thin disk, thick disk and halo giants. Methods. We use high-resolution optical spectra of 25 bulge giants in Baade's window and 55 comparison giants (4 halo, 29 thin disk and 22 thick disk giants) in the solar neighborhood. All stars have similar stellar parameters but cover a broad range in metallicity (-1.5 < Fe/H < +0.5). A standard 1D local thermodynamic equilibrium analysis using both Kurucz and MARCS models yielded the abundances of O, Na, Mg, Al, Si, Ca, Ti and Fe. Our homogeneous and differential analysis of the Galactic stellar populations ensured that systematic errors were minimized. Results. We confirm the well-established differences for α/Fe at a given metallicity between the local thin and thick disks. For all the elements investigated, we find no chemical distinction between the bulge and the local thick disk, in agreement with our previous study of C, N and O but in contrast to other groups relying on literature values for nearby disk dwarf stars. For -1.5 < Fe/H < -0.3 exactly the same trend is followed by both the bulge and thick disk stars, with a star-to-star scatter of only 0.03 dex. Furthermore, both populations share the location of the knee in the α/Fe vs. Fe/H diagram. It still remains to be confirmed that the local thick disk extends to super-solar metallicities as is the case for the bulge. These are the most stringent constraints to date on the chemical similarity of these stellar populations. Conclusions. Our findings suggest that the bulge and local thick disk stars experienced similar formation timescales, star formation rates and initial mass functions, confirming thus the main outcomes of our previous homogeneous analysis of O/Fe from infrared spectra for nearly the same sample. The identical α-enhancements of thick disk and bulge stars may reflect a rapid chemical evolution taking place before the bulge and thick disk structures we see today were formed, or it may reflect Galactic orbital migration of inner disk/bulge stars resulting in stars in the solar neighborhood with thick-disk kinematics.
Differences in the elemental abundances of planet-hosting stars in binary systems can give important clues and constraints about planet formation and evolution. In this study we performed a ...high-precision, differential elemental abundance analysis of a wide binary system, HD 80606/80607, based on high-resolution spectra with high signal-to-noise ratio obtained with Keck/HIRES. HD 80606 is known to host a giant planet with the mass of four Jupiters, but no planet has been detected around HD 80607 so far. We determined stellar parameters as well as abundances for 23 elements for these two stars with extremely high precision. Our main results are that (i) we confirmed that the two components share very similar chemical compositions, but HD 80606 is marginally more metal-rich than HD 80607, with an average difference of +0.013 ± 0.002 dex (σ = 0.009 dex); and (ii) there is no obvious trend between abundance differences and condensation temperature. Assuming that this binary formed from material with the same chemical composition, it is difficult to understand how giant planet formation could produce the present-day photospheric abundances of the elements we measure. We cannot exclude the possibility that HD 80606 might have accreted about 2.5 to 5 MEarth material onto its surface, possibly from a planet destabilised by the known highly eccentric giant.
We present a high-precision, differential elemental abundance analysis of the HAT-P-1 stellar binary based on high-resolution, high signal-to-noise ratio Keck/HIRES (High Resolution Echelle ...Spectrometer) spectra. The secondary star in this double system is known to host a transiting giant planet while no planets have yet been detected around the primary star. The derived metallicities (Fe/H) of the primary and secondary stars are identical within the errors: 0.146 ± 0.014 dex (σ = 0.033 dex) and 0.155 ± 0.007 dex (σ = 0.023 dex), respectively. Extremely precise differential abundance ratios of 23 elements have been measured (mean error of σ(X/Fe) = 0.013 dex) and are found to be indistinguishable between the two stars: ΔX/Fe (secondary − primary) = +0.001 ± 0.006 dex (σ = 0.008 dex). The striking similarity in the chemical composition of the two stellar components in HAT-P-1 is contrary to the possible 0.04 dex level difference seen in 16 Cyg A+B, which also hosts a giant planet, at least three times more massive than the one around HAT-P-1 secondary star. We conclude that the presence of giant planets does not necessarily imply differences in the chemical compositions of the host stars. The elemental abundances of each star in HAT-P-1 relative to the Sun show an identical, positive correlation with the condensation temperature of the elements; their abundance patterns are thus very similar to those observed in the majority of solar twins. In view of the Meléndez et al. interpretation of the peculiar solar abundance pattern, we conclude that HAT-P-1 experienced less efficient formation of terrestrial planets than the Sun. This is in line with the expectation that the presence of close-in giant planets preventing the formation or survival of terrestrial planets.
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