Scope
The aim of the present study is to develop physiologically‐based kinetic (PBK) models for rat and human that include intestinal microbial and hepatic metabolism of zearalenone (ZEN) in order to ...predict systemic concentrations of ZEN and to obtain insight in the contribution of metabolism by the intestinal microbiota to the overall metabolism of ZEN.
Methods and Results
In vitro derived kinetic parameters, apparent maximum velocities (Vmax) and Michaelis–Menten constants (Km) for liver and intestinal microbial metabolism of ZEN are included in the PBK models. The models include a sub‐model for the metabolite, α‐zearalenol (α‐ZEL), a metabolite known to be 60‐times more potent as an estrogen than ZEN. Integrating intestinal microbial ZEN metabolism into the PBK models revealed that hepatic metabolism drives the formation of α‐ZEL. Furthermore, the models predicted that at the tolerable daily intake (TDI) of 0.25 µg kg−1 bw the internal concentration of ZEN and α‐ZEL are three‐orders of magnitude below concentrations reported to induce estrogenicity in vitro.
Conclusion
It is concluded that combining kinetic data on liver and intestinal microbial metabolism in a PBK model facilitates a holistic view on the role of the intestinal microbiota in the overall metabolism of the foodborne xenobiotic ZEN and its bioactivation to α‐ZEL.
Physiologically based kinetic (PBK) models for rat and human were developed to integrate intestinal microbial and hepatic metabolism of zearalenone (ZEN). The models enabled the prediction of systemic concentration of ZEN and α‐zearalenol (α‐ZEL), a metabolite 60‐times more estrogenic than ZEN. These models facilitated a holistic view on the role of the intestinal microbiota in the overall metabolism of ZEN.
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•The performance of a laccase biosensor is improved by using LbL films as substrate.•LbL films contain chitosan, an ionic liquid and a copper phthalocyanine derivative.•The ...combination of their complementary functionalities improves the performance.•Improvement is due to their electrocatalytic and immobilization properties.•Biosensors with laccase on LbL layers show a LOD of 9.98·10−9 M towards catechol.
The performance of electrochemical laccase-based biosensors can be improved by immobilizing the enzyme on composite Layer-by-Layer (LbL) supports in which materials with complementary functions are combined. LbL films are formed by layers combining an electrocatalytic material which favors electron transfer (sulfonated copper phthalocyanine, CuPcS(−)), an ionic liquid which enhances the electrical conductivity of the layers (1-butyl-3-methylimidazolium tetrafluoroborate, IL(+)) and a material able to promote enzyme immobilization (chitosan, CHI(+)). Composite films with different structures have been demonstrated to be efficient electrocatalysts, producing an increase in the magnitude of the responses towards catechol. The most intense and reproducible electrocatalytic effect was observed when a layer of the CuPcS(−) was placed on top of a layer formed by a mixture of CHI(+) + IL(+) to obtain CHI(+) + IL(+)|CuPcS(−)2 films.
Biosensors with laccase immobilized on the surface of the LbL layers CHI(+) + IL(+)|CuPcS(−)2|Lac showed mediated electron transfer between the redox enzyme and the film and a reproducibility of device-to-device performance of 4.1%. The amperometric biosensor showed a sensitivity of 0.237 A·M−1 and a linear detection range from 2.4 μM to 26 μM for catechol. The excellent Limit of detection (LOD) of 8.96·10−10 M (3·σ /m) is one order of magnitude lower than that obtained in similar studies. A Michaelis-Menten constant of 3.16 μM confirms excellent enzyme-substrate affinity.
The black hole candidate and X-ray binary MAXI J1535−571 was discovered in 2017
September. During the decay of its discovery outburst, and before returning to quiescence,
the source underwent at ...least four reflaring events, with peak luminosities of ∼1035–36 erg s−1
(d/4.1 kpc)2. To investigate the nature of these flares, we analysed a sample of NICER (Neutron
star Interior Composition Explorer) observations taken with almost daily cadence. In this work,
we present the detailed spectral and timing analysis of the evolution of the four reflares. The
higher sensitivity of NICER at lower energies, in comparison with other X-ray detectors,
allowed us to constrain the disc component of the spectrum at ∼0.5 keV. We found that during
each reflare the source appears to trace out a q-shaped track in the hardness–intensity diagram
similar to those observed in black hole binaries during full outbursts. MAXI J1535−571 transits
between the hard state (valleys) and softer states (peaks) during these flares. Moreover, the
Comptonized component is undetected at the peak of the first reflare, while the disc component
is undetected during the valleys. Assuming the most likely distance of 4.1 kpc, we find that
the hard-to-soft transitions take place at the lowest luminosities ever observed in a black
hole transient, while the soft-to-hard transitions occur at some of the lowest luminosities ever
reported for such systems.
Introduction
A 2020 study in Wuhan residents reported 70.2% of participants faced the COVID-19 pandemic using active coping strategies, and we wanted to explore its comparability in Chinese Health ...Care Workers (HCWs) across 7 regions in China 1 year after the initial outbreak.
Objectives
The study analyzed coping strategies utilized by different Chinese HCWs under a stressful period like the COVID-19 pandemic and three psychological scales were used to assess its effect on five psychological outcomes such as depression, anxiety, stress, post-traumatic stress disorder and suicidal ideation.
Methods
A cross-sectional self-administered online questionnaire was conducted during the period of November 2020 and March 2021 and included sociodemographic information, work environment before and during the pandemic, experiences, fears and concerns about COVID-19 and three psychological scales including Depression, Anxiety and Stress Scale-21(DASS-21), Primary Care PTSD Screen for DSM-5 (PC-PTSD-5) and Simplified Coping Style Questionnaire (SCSQ-20). Chi-square analysis was used to explore categorical association.
Results
The findings demonstrated that 633 (52.5%) of the participants used passive coping strategies, while 600 (47.5%) used active coping strategies. Passive coping strategies with at least one mental health problem were positively correlated with participants having a previous chronic disease diagnosis, working days in a week during the outbreak, PPE availability, days in isolation for being suspected or a confirmed case of COVID-19, worries about infecting relatives and the pandemic affecting family’s financial situation.
Conclusions
Developing and creating intervention programs to strengthen active coping strategies will improve mental health outcomes in Chinese HCWs during the COVID pandemic.
Disclosure of Interest
None Declared
In this work, a multisensor system formed by nanostructured voltammetric biosensors based on phenol oxidases (tyrosinase and laccase) has been developed. The enzymes have been incorporated into a ...biomimetic environment provided by a Langmuir–Blodgett (LB) film of arachidic acid (AA). Lutetium bisphthalocyanine (LuPc2) has also been introduced in the films to act as electron mediator. The incorporation of the enzymes to the floating layers to form Tyr/AA/LuPc2 and Lac/AA/LuPc2 films has been confirmed by the expansion in the surface pressure isotherms and by the AFM images. The voltammetric response towards six phenolic compounds demonstrates the enhanced performance of the biosensors that resulted from a preserved activity of the tyrosinase and laccase combined with the electron transfer activity of LuPc2. Biosensors show improved detection limits in the range of 10−7–10−8molL−1. An array formed by three sensors AA/LuPc2, Tyr/AA/LuPc2 and Lac/AA/LuPc2 has been employed to discriminate phenolic antioxidants of interest in the food industry. The Principal Component Analysis scores plot has demonstrated that the multisensor system is able to discriminate phenols according to the number of phenolic groups attached to the structure. The system has also been able to discriminate grapes of different varieties according to their phenolic content. This good performance is due to the combination of four factors: the high functionality of the enzyme obtained using a biomimetic immobilization, the signal enhancement caused by the LuPc2 mediator, the improvement in the selectivity induced by the enzymes and the complementary activity of the enzymatic sensors demonstrated in the loading plots.
•A bioelectronic tongue based on phenol oxidases biosensors has been developed.•The biomimetic environment of the biosensors improves the selectivity and sensitivity.•The system is able to discriminate phenols according to their chemical structure.•The system is able to discriminate grapes according to their phenolic content.•The sensors of the array show high cross-selectivity.
This manuscript reports preliminary results obtained by combining estimates of two or three (among seven) quantitative ultrasound (QUS) parameters in a model-free, multi-parameter classifier to ...differentiate breast carcinomas from fibroadenomas (the most common benign solid tumor). Forty-three patients scheduled for core biopsy of a suspicious breast mass were recruited. Radiofrequency echo signal data were acquired using clinical breast ultrasound systems equipped with linear array transducers. The reference phantom method was used to obtain system-independent estimates of the specific attenuation (ATT), the average backscatter coefficients, the effective scatterer diameter (ESD) and an effective scatterer diameter heterogeneity index (ESDHI) over regions of interest within each mass. In addition, the envelope amplitude signal-to-noise ratio (SNR), the Nakagami shape parameter, m, and the maximum collapsed average (maxCA) of the generalized spectrum were also computed. Classification was performed using the minimum Mahalanobis distance to the centroids of the training classes and tested against biopsy results. Classification performance was evaluated with the area under the receiver operating characteristic (ROC) curve. The best performance with a two-parameter classifier used the ESD and ESDHI and resulted in an area under the ROC curve of 0.98 (95% confidence interval CI: 0.95-1.00). Classification performance improved with three parameters (ATT, ESD and ESDHI) yielding an area under the ROC curve of 0.999 (0.995-1.000). These results suggest that system-independent QUS parameters, when combined in a model-free classifier, are a promising tool to characterize breast tumors. A larger study is needed to further test this idea.
Background
A lack of transparency and reporting standards in the scientific community has led to increasing and widespread concerns relating to reproduction and integrity of results. As an omics ...science, which generates vast amounts of data and relies heavily on data science for deriving biological meaning, metabolomics is highly vulnerable to irreproducibility. The metabolomics community has made substantial efforts to align with FAIR data standards by promoting open data formats, data repositories, online spectral libraries, and metabolite databases. Open data analysis platforms also exist; however, they tend to be inflexible and rely on the user to adequately report their methods and results. To enable FAIR data science in metabolomics, methods and results need to be transparently disseminated in a manner that is rapid, reusable, and fully integrated with the published work. To ensure broad use within the community such a framework also needs to be inclusive and intuitive for both computational novices and experts alike.
Aim of Review
To encourage metabolomics researchers from all backgrounds to take control of their own data science, mould it to their personal requirements, and enthusiastically share resources through open science.
Key Scientific Concepts of Review
This tutorial introduces the concept of interactive web-based computational laboratory notebooks. The reader is guided through a set of experiential tutorials specifically targeted at metabolomics researchers, based around the Jupyter Notebook web application, GitHub data repository, and Binder cloud computing platform.
Allergic rhinitis is the most common allergic disease encountered in a primary care setting. Diagnosis is often made clinically based on response to empiric therapy. However, with long-term treatment ...failure and/or atypical disease presentation, a differential diagnosis should be considered. The following is a report of an unusual and rare presentation of a subglottic tracheal angiomyomatous hamartoma in an adolescent, treated for many years as allergic rhinoconjunctivitis and asthma.
A 12-year-old Caucasian was referred to the allergy clinic with a lifetime history of bronchospasms and rhinoconjunctivitis symptoms, treated for many years for asthma and environmental allergies. Cough, posterior nasal drainage, self-described "choking on phlegm," and a sensation of "a flap in the throat,", worsened 5 months prior to the initial evaluation. Puncture skin testing for common environmental allergens was negative. Spirometry, performed due to history of chronic cough, showed blunting of the forced expiratory phase. A chest X-ray, immediately ordered to rule out possible extrapulmonary obstruction, showed bilateral bibasilar infiltrates. A noncontrast computerized tomographic scan of the chest, ordered to further elucidate X-ray findings, revealed a subglottic tracheal mass. Following a subsequent transfer and admission to a tertiary hospital center, microlaryngoscopy, bronchoscopy, and microsuspension laryngoscopy were performed to remove the tracheal mass. Pathology confirmed squamous mucosa with polypoid angiomyomatous changes and chronic inflammatory features consistent with angiomyomatous hamartoma. Surgical intervention was successful, and follow-up 1 year postoperatively revealed a healthy, asymptomatic adolescent child with normal lung function.
Although posterior nasal drainage and cough are typical presenting symptoms in the general patient population, they may be clinically impactful as they could disguise more serious medical conditions. A detailed history and careful physical examination may provide a high index of suspicion of disease, and can help work the differential diagnosis. This case presentation is the first documentation of subglottic hamartoma reported in the pediatric literature with clinical manifestation of environmental allergy and asthma symptoms.
The response of ecosystems to human stressors can be affected by local natural disturbance conditions, yet the effects of a given combination of human and natural stressors are hard to predict as ...there are few studies on the subject. In the present work, we studied the effects of varying intensities of trampling (i.e. human stressor) on mussel beds at 2 sites characterized by distinct wave disturbance regimes (i.e. natural stressor) on southwestern Atlantic rocky shores (Patagonia, Argentina). We found that mussels at a wave-exposed site had greater attachment and compressive strength than mussels from a wave-protected site. These enhanced physical attributes, therefore, were expected to provide wave-exposed communities with higher resistance to human trampling. This prediction was supported, with mussel cover loss on experimentally trampled plots being lower on the wave-exposed shore than on the wave-protected shore for all intensities applied. Our results show antagonistic effects of a natural (wave exposure) and an anthropogenic (trampling) stressor on the same type of rocky shore community. As human stressors are intensifying globally, studies assessing the combined effects of natural and anthropogenic disturbances are needed to properly understand how similar communities may be affected under varying natural conditions. This information is fundamental in order to propose appropriate conservation actions.
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