Carbon fibers, obtained by carbonizing poly(p-phenylene benzobisoxazole) (PBO) fibers at 900 °C, graphitize extensively upon heat treatment at higher temperatures (2700 °C). In this work, XRD, Raman ...spectroscopy, and HRTEM are used to monitor the structural and nanostructural transformations of the carbon material under heat-treatment at several temperatures in the interval 900–2800 °C. These different techniques provide complementary information, especially regarding the spatial resolution they achieve. They highlight a specific nonconventional mode of graphitization for this unexpectedly graphitizable precursor. The reliability in the determination of L a crystallite sizes from these three techniques is compared and discussed. The existence of four steps in the graphitization of PBO-derived carbon fibers is inferred.
To support the nuances of collaborative work, many researchers have been exploring the field of Augmented Reality (AR), aiming to assist in co-located or remote scenarios. Solutions using AR allow ...taking advantage from seamless integration of virtual objects and real-world objects, thus providing collaborators with a shared understanding or common ground environment. However, most of the research efforts, so far, have been devoted to experiment with technology and mature methods to support its design and development. Therefore, it is now time to understand where the field stands and how well can it address collaborative work with AR, to better characterize and evaluate the collaboration process. In this article, we perform an analysis of the different dimensions that should be taken into account when analysing the contributions of AR to the collaborative work effort. Then, we bring these dimensions forward into a conceptual framework and propose an extended human-centered taxonomy for the categorization of the main features of Collaborative AR. Our goal is to foster harmonization of perspectives for the field, which may help create a common ground for systematization and discussion. We hope to influence and improve how research in this field is reported by providing a structured list of the defining characteristics. Finally, some examples of the use of the taxonomy are presented to show how it can serve to gather information for characterizing AR-supported collaborative work, and illustrate its potential as the grounds to elicit further studies.
The renin‐angiotensin system (RAS) is an endocrine system composed of two main axes: the classical and the counterregulatory, very often displaying opposing effects. The classical axis, primarily ...mediated by angiotensin receptors type 1 (AT1R), is linked to obesity‐associated metabolic effects. On the other hand, the counterregulatory axis appears to exert antiobesity effects through the activation of two receptors, the G protein‐coupled receptor (MasR) and Mas‐related receptor type D (MrgD). The local RAS in adipose organ has prompted extensive research into white adipose tissue and brown adipose tissue (BAT), with a key role in regulating the cellular and metabolic plasticity of these tissues. The MasR activation favors the brown plasticity signature in the adipose organ by improve the thermogenesis, adipogenesis, and lipolysis, decrease the inflammatory state, and overall energy homeostasis. The MrgD metabolic effects are related to the maintenance of BAT functionality, but the signaling remains unexplored. This review provides a summary of RAS counterregulatory actions triggered by Mas and MrgD receptors on adipose tissue plasticity. Focus on the effects related to the morphology and function of adipose tissue, especially from animal studies, will be given targeting new avenues for treatment of obesity‐associated metabolic effects.
The C–S cross‐coupling reaction is a very efficient and powerful tool for constructing C–S bonds. Despite the well‐reported C–S cross‐coupling protocols using aryl halides, this reaction using ...sp2‐hybridized nonaromatic halides is still challenging. Herein, we report light‐assisted C–S cross‐coupling between thiols and 5‐chlorobenzofurazan under blue LED irradiation. We used a new nickel catalyst to synthesize 11 unpublished compounds. Furthermore, we assessed the mechanism and the influence of light irradiation on this reaction and proposed a plausible mechanism that is mediated by the excited state of the nickel catalyst promoted by irradiation with blue light and the C–S coupling product formed. Notably, C–S cross‐coupling under light irradiation was performed for the first time using a nickel catalyst in the absence of an external photocatalyst. We demonstrated that because nickel has a low energy barrier for oxidative addition, this protocol proceeded efficiently using chlorine as a leaving group, and the excited state of the nickel catalyst promoted reductive elimination with a lower energy barrier. It is important to mention that the procedure was tolerated by many functional groups within the thiol, affording a greater than 99% yield after reacting for 6 h.
•Infectious SARS-CoV-2 was spiked in river water and wastewater to assess its viability•Viability assessed in filtered and unfiltered samples, at 4°C and 24°C•SARS-CoV-2 remained viable longer in ...filtered compared with unfiltered samples•SARS-CoV-2 persistence at 4°C was 4 to 4.5 times longer than at 24°C•Results relevant to assess risks to public health related to contaminated water
COVID-19 patients can excrete viable SARS-CoV-2 virus via urine and faeces, which has raised concerns over the possibility of COVID-19 transmission via aerosolized contaminated water or via the faecal-oral route. These concerns are especially exacerbated in many low- and middle-income countries, where untreated sewage is frequently discharged to surface waters. SARS-CoV-2 RNA has been detected in river water (RW) and raw wastewater (WW) samples. However, little is known about SARS-CoV-2 viability in these environmental matrices. Determining the persistence of SARS-CoV-2 in water under different environmental conditions is of great importance for basic assumptions in quantitative microbial risk assessment (QMRA). In this study, the persistence of SARS-CoV-2 was assessed using plaque assays following spiking of RW and WW samples with infectious SARS-CoV-2 that was previously isolated from a COVID-19 patient. These assays were carried out on autoclaved RW and WW samples, filtered (0.22 µm) and unfiltered, at 4 °C and 24 °C. Linear and nonlinear regression models were adjusted to the data. The Weibull regression model achieved the lowest root mean square error (RMSE) and was hence chosen to estimate T90 and T99 (time required for 1 log and 2 log reductions, respectively). SARS-CoV-2 remained viable longer in filtered compared with unfiltered samples. RW and WW showed T90 values of 1.9 and 1.2 day and T99 values of 6.4 and 4.0 days, respectively. When samples were filtered through 0.22 µm pore size membranes, T90 values increased to 3.3 and 1.5 days, and T99 increased to 8.5 and 4.5 days, for RW and WW samples, respectively. Remarkable increases in SARS-CoV-2 persistence were observed in assays at 4 °C, which showed T90 values of 7.7 and 5.5 days, and T99 values of 18.7 and 17.5 days for RW and WW, respectively. These results highlight the variability of SARS-CoV-2 persistence in water and wastewater matrices and can be highly relevant to efforts aimed at quantifying water-related risks, which could be valuable for understanding and controlling the pandemic.
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For the past ten years, psychologists and psychoanalysts in France have been asked whether or not the clinical setting should be presented as a safe space for populations facing specific systemic ...discriminations, such as LGBTQI+ persons. This discussion illustrates the complex relationship between psychoanalysis and gender studies in France today. An analysis of the context in which the demand for a safe psychoanalyst appears and a discussion on the specificity of the use of language in clinical work bring elements for an answer.
Separation of PEGylated protein mixtures into individual species is a challenging procedure, and many efforts have been focused on creating novel chromatographic supports for this purpose. In this ...study, a new monolithic stationary phase with hyperbranched nanostructures was chemically synthesized. For this, monoliths with a support matrix of poly (glycidyl methacrylate‐co‐ethylene dimethacrylate) and ethylenediamine chemistry were modified with third‐generation dendrons with butyl‐end groups. The new monolith was analyzed by infrared spectroscopy, confirming the dendron with butyl ligands and exhibited low mass transfer resistance as observed by breakthrough frontal analysis. This support was able to separate mono‐PEG ribonuclease A from the PEGylation mixture, indicated by a single band (∼30 kDa) in the electrophoretic analysis. Moreover, the separation of mono‐PEGylated positional isomers was probably observed, as the protein with ∼30 kDa was found in two separate peaks. Interestingly, the dendronized monolith allowed the separation of the reaction mixture into individual PEGylated species when using high ammonium sulfate concentrations (2 M). A correlation between the PEGylation degree and the strength of the hydrophobic interactions on the monolith was observed. This chromatographic approach combines the natural branched architecture of dendrons and the higher capabilities of the monoliths enhancing the hydrophobic surface area, and therefore the interaction between the PEGylated proteins and ligands. Thus, the novel support represents a novel platform for the purification of PEGylated from non‐PEGylated proteins with biotechnological applications.
is used to prepare the psychoactive beverage ayahuasca, and both have therapeutic potential for the treatment of many central nervous system (CNS) conditions. This study aimed to isolate new ...bioactive compounds from
extract and evaluate their biological activity, and that of the known β-carboline components of the plant (harmine, harmaline, and tetrahydroharmine), in BV-2 microglial cells, the in vivo activation of which is implicated in the physiopathology of CNS disorders.
extract was fractionated using semipreparative liquid chromatography (HPLC-DAD) and the exact masses (M + H
/
) of the compounds in the 5 isolated fractions were determined by high-resolution LC-MS/MS: F1 (174.0918 and 233.1289), F2 (353.1722), F3 (304.3001), F4 (188.1081), and F5 (205.0785). Harmine (75.5-302 µM) significantly decreased cell viability after 2 h of treatment and increased the number of necrotic cells and production of reactive oxygen species at equal or lower concentrations after 24 h. F4 did not impact viability but was also cytotoxic after 24 h. Most treatments reduced proinflammatory cytokine production (IL-2, IL-6, IL-17, and/or TNF), especially harmaline and F5 at 2.5 µM and higher concentrations, tetrahydroharmine (9.3 µM and higher), and F5 (10.7 µM and higher). The results suggest that the compounds found in
extract have anti-inflammatory potential that could be explored for the development of treatments for neurodegenerative diseases.
The aim of this review was to evaluate the prevalence of dental caries, periodontal disease, malocclusion, and tooth wear in indigenous in Brazil. A systematic review of observational studies was ...performed according to the PRISMA guidelines (CRD42020218704). The search strategy involved the electronic databases of Embase, LILACS, PubMed, Web of Science, Scopus, and the CAPES Theses and Dissertations for gray literature. The eligibility criteria consisted of publications that assessed the prevalence of oral conditions in indigenous populations in Brazil. Studies with indigenous people living in urban area were excluded. The risk of bias was evaluated by using JBI Critical Appraisal for prevalence studies. Thirty studies were included in the review, and the majority showed a low risk of bias. A meta-analysis of 20 studies was conducted using the random-effects model and a 95% confidence interval. Several ethnicities were studied in isolation or in groups (n = 7,627 for dental caries; n = 2,774 for periodontal disease; n = 1,067 for malocclusion; n = 150 for tooth wear). The prevalence of caries ranged from 50% among indigenous people aged 18-36 months to 100% among those aged 65-74 years. The prevalence of periodontal disease ranged from 58% to 83%. The prevalence of malocclusion was 43%. Tooth wear was assessed in only one ethnic group and showed a prevalence of 100% in indigenous people aged >18 years. The certainty of evidence assessed by the GRADE system ranged from very low to moderate. This systematic review showed significant differences in the prevalence of dental caries, periodontal disease and malocclusion between indigenous population groups and territories in which indigenous people live.
Using color in visualization: A survey Silva, Samuel; Sousa Santos, Beatriz; Madeira, Joaquim
Computers & graphics,
04/2011, Letnik:
35, Številka:
2
Journal Article
Recenzirano
Color mapping is an important technique used in visualization to build visual representations of data and information. With output devices such as computer displays providing a large number of ...colors, developers sometimes tend to build their visualization to be visually appealing, while forgetting the main goal of clear depiction of the underlying data.
Visualization researchers have profited from findings in adjoining areas such as human vision and psychophysics which, combined with their own experience, enabled them to establish guidelines that might help practitioners to select appropriate color scales and adjust the associated color maps, for particular applications.
This survey presents an overview on the subject of color scales by focusing on important guidelines, experimental research work and tools proposed to help non-expert users.
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