Background and purpose
Specific respiratory tract infections, including COVID‐19, may cause smell and/or taste disorders (STDs) with increased frequency. The aim was to determine whether new‐onset ...STDs are more frequent amongst COVID‐19 patients than influenza patients.
Method
This was a case–control study including hospitalized patients of two tertiary care centres. Consecutive patients positive for COVID‐19 polymerase chain reaction (cases) and patients positive for influenza polymerase chain reaction (historical control sample) were assessed during specific periods, employing a self‐reported STD questionnaire.
Results
Seventy‐nine cases and 40 controls were included. No significant differences were found in basal features between the two groups. New‐onset STDs were significantly more frequent amongst cases (31, 39.2%) than in the control group (5, 12.5 %) adjusted odds ratio 21.4 (2.77–165.4, P = 0.003). COVID‐19 patients with new‐onset STDs were significantly younger than COVID‐19 patients without STDs (52.6 ± 17.2 vs. 67.4 ± 15.1, P < 0.001). Amongst COVID‐19 patients who presented STDs, 22 (70.9%) recalled an acute onset and it was an initial manifestation in 11 (35.5%). Twenty‐five (80.6%) presented smell disorders (mostly anosmia, 14, 45.2%) and 28 (90.3%) taste disorders (mostly ageusia, 14, 45.2%). Only four (12.9 %) reported concomitant nasal obstruction. The mean duration of STD was 7.5 ± 3.2 days and 12 patients (40%) manifested complete recovery after 7.4 ± 2.3 days of onset.
Conclusion
New‐onset STDs were significantly more frequent amongst COVID‐19 patients than influenza patients; they usually had an acute onset and were commonly an initial manifestation. The use of STD assessment in anamnesis as a hint for COVID‐19 and to support individuals’ self‐isolation in the current epidemic context is suggested.
Context. The direct detection of exoplanets with high-contrast imaging requires advanced data processing methods to disentangle potential planetary signals from bright quasi-static speckles. Among ...them, angular differential imaging (ADI) permits potential planetary signals with a known rotation rate to be separated from instrumental speckles that are either statics or slowly variable. The method presented in this paper, called ANDROMEDA for ANgular Differential OptiMal Exoplanet Detection Algorithm, is based on a maximum likelihood approach to ADI and is used to estimate the position and the flux of any point source present in the field of view. Aims. In order to optimize and experimentally validate this previously proposed method, we applied ANDROMEDA to real VLT/NaCo data. In addition to its pure detection capability, we investigated the possibility of defining simple and efficient criteria for automatic point source extraction able to support the processing of large surveys. Methods. To assess the performance of the method, we applied ANDROMEDA on VLT/NaCo data of TYC-8979-1683-1 which is surrounded by numerous bright stars and on which we added synthetic planets of known position and flux in the field. In order to accommodate the real data properties, it was necessary to develop additional pre-processing and post-processing steps to the initially proposed algorithm. We then investigated its skill in the challenging case of a well-known target, β Pictoris, whose companion is close to the detection limit and we compared our results to those obtained by another method based on principal component analysis (PCA). Results. Application on VLT/NaCo data demonstrates the ability of ANDROMEDA to automatically detect and characterize point sources present in the image field. We end up with a robust method bringing consistent results with a sensitivity similar to the recently published algorithms, with only two parameters to be fine tuned. Moreover, the companion flux estimates are not biased by the algorithm parameters and do not require a posteriori corrections. Conclusions. ANDROMEDA is an attractive alternative to current standard image processing methods that can be readily applied to on-sky data.
We present results from the most comprehensive radio monitoring campaign towards the closest star to our Sun, Proxima Centauri. We report 1.1–3.1 GHz observations with the Australia Telescope Compact ...Array over 18 consecutive days in April 2017. We detected radio emission from Proxima Centauri for most of the observing sessions, which spanned ~1.6 orbital periods of the planet Proxima b. The radio emission is stronger at the low-frequency band, centered around 1.6 GHz, and is consistent with the expected electron-cyclotron frequency for the known star’s magnetic field intensity of ~600 gauss. The 1.6 GHz light curve shows an emission pattern that is consistent with the orbital period of the planet Proxima b around the star Proxima, with its maxima of emission happening near the quadratures. We also observed two short-duration flares (a few minutes) and a long-duration burst (about three days) whose peaks happened close to the quadratures. We find that the frequency, large degree of circular polarization, change in the sign of circular polarization, and intensity of the observed radio emission are all consistent with expectations from electron cyclotron-maser emission arising from sub-Alfvénic star–planet interaction. We interpret our radio observations as signatures of interaction between the planet Proxima b and its host star Proxima. We advocate for monitoring other dwarf stars with planets to eventually reveal periodic radio emission due to star–planet interaction, thus opening a new avenue for exoplanet hunting and the study of a new field of exoplanet–star plasma interaction.
BACKGROUND AND PURPOSE
Efavirenz (EFV) is widely used in the treatment of HIV‐1 infection. Though highly efficient, there is growing concern about EFV‐related side effects, the molecular basis of ...which remains elusive.
EXPERIMENTAL APPROACH
In vitro studies were performed to address the effect of clinically relevant concentrations of EFV (10, 25 and 50 µM) on human hepatic cells.
KEY RESULTS
Cellular proliferation and viability were reduced in a concentration‐dependent manner. Analyses of the cell cycle and several cell death parameters (chromatin condensation, phosphatidylserine exteriorization, mitochondrial proapoptotic protein translocation and caspase activation) revealed that EFV triggered apoptosis via the intrinsic pathway. In addition, EFV directly affected mitochondrial function in a reversible manner, inducing a decrease in mitochondrial membrane potential and an increase in mitochondrial superoxide production, followed by a reduction in cellular glutathione content. The rapidity of these actions rules out any involvement of mitochondrial DNA replication, which, until now, was thought to be the main mechanism of mitochondrial toxicity of antiretroviral drugs. Importantly, we also observed an increase in mitochondrial mass, manifested as an elevated cardiolipin content and enhanced expression of mitochondrial proteins, which was not paralleled by an increase in the mtDNA/nuclear DNA copy number ratio. The toxic effect of EFV was partially reversed by antioxidant pretreatment, which suggests ROS generation is involved in this effect.
CONCLUSION AND IMPLICATIONS
Clinically relevant concentrations of EFV were shown to be mitotoxic in human hepatic cells in vitro, which may be pertinent to the understanding of the hepatotoxicity associated with this drug.
Lithium-sulfur batteries (Li-S) are identified as one of the most promising rechargeable energy systems due to their high theoretical capacity, high gravimetric energy density, low cost and low ...environmental impact. However, the insulating nature of sulfur and the migration of soluble polysulfides during discharge limit their practical application. In an attempt to mitigate these drawbacks here we report the preparation of a novel composite formed by hydrothermally reduced graphene oxide (HrGO) and submicrometer-sized sulfur particles. The role of HrGO is not restricted to enhance the electronic conductivity of the composite, but also sulfur wrapping in order to prevent polysulfides migration. Besides, the addition of polyvinylpyrrolidone (PVP) during the synthesis of the sulfur particles allows a greater control of their size and improves its homogeneous distribution within the composite. The material is tested as cathode for Li-S batteries showing reversible capacities over 900 mAh g−1 at a rate of 0.2 C and more than 650 mAh g−1 after 100 charge-discharge cycles. Moreover, this simplistic and environmentally friendly approach allow obtaining composites with sulfur loadings as high as 92 wt%, and large areal capacities up to 1.5 mAh cm−2.
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Abstract The aim of this experimental study is to predict the long-term mechanical behavior of a porous scaffold implanted in a cartilage defect for tissue engineering purpose. Fatigue studies were ...performed by up to 100,000 unconfined compression cycles in a polycaprolactone (PCL) scaffold with highly interconnected pores architecture. The scaffold compliance, stress–strain response and hysteresis energy have been measured after different number of fatigue cycles, while the morphology has been observed by scanning electron microscopy at the same fatigue times. To simulate the growing tissue in the scaffold/tissue construct, the scaffold was filled with an aqueous solution of polyvinyl alcohol (PVA) and subjected to repeating cycles of freezing and thawing that increase the hydrogel stiffness. Fatigue studies show that the mechanical loading provokes failure of the dry scaffold at a smaller number of deformation cycles than when it is immersed in water, and also that 100,000 compressive dynamic cycles do not affect the scaffold/gel construct. This shows the stability of the scaffold implanted in a chondral defect and gives a realistic simulation of the mechanical performance from implantation of the empty scaffold to regeneration of the new tissue inside the scaffold׳s pores.
Currently, Coronavirus disease (COVID-19), one of the most infectious diseases in the 21st century, is diagnosed using RT-PCR testing, CT scans and/or Chest X-Ray (CXR) images. CT (Computed ...Tomography) scanners and RT-PCR testing are not available in most medical centers and hence in many cases CXR images become the most time/cost effective tool for assisting clinicians in making decisions. Deep learning neural networks have a great potential for building COVID-19 triage systems and detecting COVID-19 patients, especially patients with low severity. Unfortunately, current databases do not allow building such systems as they are highly heterogeneous and biased towards severe cases. This article is threefold: (i) we demystify the high sensitivities achieved by most recent COVID-19 classification models, (ii) under a close collaboration with Hospital Universitario Clínico San Cecilio, Granada, Spain, we built COVIDGR-1.0, a homogeneous and balanced database that includes all levelsof severity, from normal with Positive RT-PCR, Mild, Moderate to Severe. COVIDGR-1.0 contains 426 positive and 426 negative PA (PosteroAnterior) CXR views and (iii) we propose COVID Smart Data based Network (COVID-SDNet) methodology for improving the generalization capacity of COVID-classification models. Our approach reaches good and stable results with an accuracy of 97.72% ± 0.95%, 86.90% ± 3.20%, 61.80% ± 5.49% in severe, moderate and mild COVID-19 severity levels. Our approach could help in the early detection of COVID-19. COVIDGR-1.0 along with the severity level labels are available to the scientific community through this link https://dasci.es/es/transferencia/ open-data/covidgr/.
Summary
Aim: Urinary tract infection (UTI) caused by resistant bacteria is becoming more prevalent. We investigate characteristics and associated risk factors for UTIs resulting from ...extended‐spectrum beta‐lactamase (ESBL)‐producing enterobacteria.
Methods: Retrospective study of urinary tract isolates of ESBL‐producing enterobacteria in adults (2009 and 2010). We included 400 patients and 103 controls (UTI caused by non‐ESBL Escherichia coli). Clinical and demographic information was obtained from medical records. Comorbidity was evaluated using Charlson Index (CI). Strains were identified using VITEK 2 system.
Results: A total of 400 isolates were obtained (93%E. coli and 7%Klebsiella spp). In 2009, 6% of cultures were ESBL‐producing E. coli and 7% in 2010. 37% of patients were men and 81% were aged ≥ 60 years. CI was 2.3 ± 1.8 (high comorbidity: 42.8%). 41.5% of strains were susceptible to amoxicillin‐clavulanate, 85.8% to fosfomycin and 15.5% to ciprofloxacin. The total number of ESBL E. coli positive urine cultures during hospital admission was 97 and, compared with 103 controls, risk factors for UTI caused by ESBL‐ E. coli strains in hospitalised patients were nursing home residence (p < 0.001), diabetes (p = 0.032), recurrent UTI (p = 0.032) and high comorbidity (p = 0.002). In addition, these infections were associated with more symptoms (p < 0.001) and longer admission (p = 0.004).
Conclusions: Urinary tract infection caused by ESBL are a serious problem and identifying risk factors facilitates early detection and improved prognosis. Male sex, hospitalisation, institutionalisation, diabetes, recurrent UTI and comorbidity were risk factors and were associated with more symptoms and longer hospital stay.
•A 3D transient model for the simulation of fixed bed biomass combustion was developed.•The thermal conversion of solid wood was modelled by solving transport equations of several variables.•A ...compaction model was introduced to account for the local shrinkage of the bed.•The model predictions was compared with experimental data.
CFD codes are well equipped in the resolution of the gas phase combustion, however the solid phase modelling still needs to be developed. The aim of this work is to implement several submodels of thermal conversion of solid fuels and the interaction with the gas phase in a commercial CFD code. For this, a set of submodels taken from literature is proposed for simulating the combustion of solid biomass in packed beds. The modelling method implements several variables that represent the main parameters of the solid mass in the framework of a commercial CFD code. The transport equations of the solid phase are used to predict the transient evolution of the bed and the interaction with the gas phase within the bed and the area surrounding it. The radiative heat transfer is modelled by modifying the standard Discrete Ordinates model to consider the temperature difference between the solid and gas phases and the high absorptivity of the medium. A compaction model is introduced to account for the local shrinkage of the bed due to the collapse of regions weakened by their combustion. The results of the model are presented and discussed by the contrast of the model through the simulation of an experimental burner whose ignition rates, maximum temperatures, and drying, devolatilisation, and char thicknesses are known. The model shows a reasonably accuracy in the predictions of some variables as ignition rates, maximum temperatures and the bed height transient evolution. The comparison of the drying, devolatilisation, and char thicknesses for different air mass fluxes shows reasonably good tendencies even thought the values are excessively high. Compared with previous works done by the authors and by others, it can be seen that the introduction of a bed compaction submodel, as the one presented here, can help in the realistic estimation of the processes involved in packed be combustion of biomass and point to particle shrinkage and bed’s mechanics as an important process to be considered.
Regio- and stereoselective Baeyer–Villiger oxidations are difficult to achieve by classical chemical means, particularly when large, functionalized molecules are to be converted. Biocatalysis using ...flavin-containing Baeyer–Villiger monooxygenases (BVMOs) is a well-established tool to address these challenges, but known BVMOs have shortcomings in either stability or substrate selectivity. We characterized a novel BVMO from the thermophilic fungus Thermothelomyces thermophila, determined its three-dimensional structure, and demonstrated its use as a promising biocatalyst. This fungal enzyme displays excellent enantioselectivity, acts on various ketones, and is particularly active on polycyclic molecules. Most notably we observed that the enzyme can perform oxidations on both the A and D ring when converting steroids. These functional properties can be linked to unique structural features, which identify enzymes acting on bulky substrates as a distinct subgroup of the BVMO class.
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