Structural and chemical properties of RF sputtered a-C/WOx bilayers

Amorphous carbon on tungsten oxide (a-C/WOx) bilayers were deposited, on glass and silicon substrates, by radio-frequency (RF) sputtering. The WOx layers are obtained from a pure tungsten target in a mixture of argon and oxygen while the a-C ones were obtained from a pure graphite target in a pure argon plasma. The structural and chemical properties of the a-C/WOx interface were investigated by Grazing Incidence X-Ray Diffraction (GIXRD), X-Ray Reflectometry (XRR) and Electron Dispersive Analysis of X-Ray (EDAX). The XRR spectra show that the a-C/WOx interface is strongly reactive, for high RF powers, with the formation of an inhomogeneous WOxCy total layer. The density of this layer is much smaller than the WOx one. For low RF powers, the a-C/WOx interface is also reactive and the total layer obtained is inhomogeneous in depth but the W atoms content in the top layer is relatively small. This result is also confirmed by the EDAX analyses. The GIXRD spectra show that the WOx layers are crystallized while there is no formation of crystallized tungsten carbides or oxycarbides.Amorphous carbon on tungsten oxide (a-C/WOx) bilayers were deposited, on glass and silicon substrates, by radio-frequency (RF) sputtering. The WOx layers are obtained from a pure tungsten target in a mixture of argon and oxygen while the a-C ones were obtained from a pure graphite target in a pure argon plasma. The structural and chemical properties of the a-C/WOx interface were investigated by Grazing Incidence X-Ray Diffraction (GIXRD), X-Ray Reflectometry (XRR) and Electron Dispersive Analysis of X-Ray (EDAX). The XRR spectra show that the a-C/WOx interface is strongly reactive, for high RF powers, with the formation of an inhomogeneous WOxCy total layer. The density of this layer is much smaller than the WOx one. For low RF powers, the a-C/WOx interface is also reactive and the total layer obtained is inhomogeneous in depth but the W atoms content in the top layer is relatively small. This result is also confirmed by the EDAX analyses. The GIXRD spectra show that the WOx layers are crystallized while there is no formation of crystallized tungsten carbides or oxycarbides

Coronavirus and Nutrition: Approach for Boosting Immune System in Morocco

The Covid-19 pandemic is a pandemic of an emerging infectious disease, the 2019 coronavirus disease Covid-19, caused by the SARS-CoV-2 coronavirus. The essential protective measures recommended by WHO (2020) to limit the spread of the Coronavirus (Covid-19) limited in the suppression of travel, quarantine and containment. In the first part of this review, we will examine the origin of the coronavirus, the modes of spread and their adverse effects on human health. We will include in our analysis the nutritional importance of the different approaches based on mechanisms to boost the immune system and therefore good viral defense. The immune system helps protect the host against environmental agents such as pathogenic microorganisms (bacteria, fungi and viruses), thus preserving the integrity of the organism. To preserve the defense mechanisms of the organisms, an adequate nutritional state must be maintained with adequate intakes of calories, vitamins, minerals and water which must be continuously provided by a healthy diet. In addition, it is necessary to have nutritional information that will help boost the immune system of people in the fight against Covid-19, nutritional diagnosis and early nutritional management of affected patients must be integrated into the overall therapeutic strategy. Several clinical data have shown that micronutrients like vitamins, including vitamins A, C, D, E, B12, B6 and folic acid; trace elements like iron, zinc, copper, magnesium, selenium, and omega-3 fatty acids like docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) play a major role in supporting the immune system

Transcriptomics reveal an integrative role for maternal thyroid hormones during zebrafish embryogenesis

Thyroid hormones (THs) are essential for embryonic brain development but the genetic mechanisms involved in the action of maternal THs (MTHs) are still largely unknown. As the basis for understanding the underlying genetic mechanisms of MTHs regulation we used an established zebrafish monocarboxylic acid transporter 8 (MCT8) knock-down model and characterised the transcriptome in 25hpf zebrafish embryos. Subsequent mapping of differentially expressed genes using Reactome pathway analysis together with in situ expression analysis and immunohistochemistry revealed the genetic networks and cells under MTHs regulation during zebrafish embryogenesis. We found 4,343 differentially expressed genes and the Reactome pathway analysis revealed that TH is involved in 1681 of these pathways. MTHs regulated the expression of core developmental pathways, such as NOTCH and WNT in a cell specific context. The cellular distribution of neural MTH-target genes demonstrated their cell specific action on neural stem cells and differentiated neuron classes. Taken together our data show that MTHs have a role in zebrafish neurogenesis and suggest they may be involved in cross talk between key pathways in neural development. Given that the observed MCT8 zebrafish knockdown phenotype resembles the symptoms in human patients with Allan-Herndon-Dudley syndrome our data open a window into understanding the genetics of this human congenital condition.Portuguese Fundacao para Ciencia e Tecnologia (FCT) [PTDC/EXPL/MARBIO/0430/2013]; CCMAR FCT Plurianual financing [UID/Multi/04326/2013]; FCT [SFRH/BD/111226/2015, SFRH/BD/108842/2015, SFRH/BPD/89889/2012]; FCT-IF Starting Grant [IF/01274/2014]info:eu-repo/semantics/publishedVersio

Attitudes of US medical trainees towards neurology education: "Neurophobia" - a global issue

<p>Abstract</p> <p>Background</p> <p>Several studies in the United Kingdom and Asia have suggested that medical students and residents have particular difficulty in diagnosing and managing patients with neurological problems. Little recent information is available for US trainees. We examined whether students and residents at a US university have difficulty in dealing with patients with neurological problems, identified the perceived sources of these difficulties and provide suggestions for the development of an effective educational experience in neurology.</p> <p>Methods</p> <p>A questionnaire was administered to third and fourth year medical students at a US school of medicine and to residents of an internal medicine residency program affiliated with that school. Perceived difficulties with eight medical specialties, including neurology, were examined. Methods considered to be most useful for learning medicine were documented. Reasons why neurology is perceived as difficult and ways to improve neurological teaching were assessed.</p> <p>Results</p> <p>152 surveys were completed. Participation rates varied, with medical students having higher response rates (> 50%) than medical residents (27%-48%). Respondents felt that neurology was the medical specialty they had least knowledge in (p < 0.001) and was most difficult (p < 0.001). Trainees also felt they had the least confidence when dealing with patients with neurological complaints (p < 0.001). Residents felt more competent in neurology than students (p < 0.001). The paramount reasons for perceived difficulties with neurology were the complexity of neuroanatomy, limited patient exposure and insufficient teaching. Transition from pre-clinical to clinical medicine led to a doubling of "poor" ratings for neurological teaching. Over 80% of the respondents felt that neurology teaching could be improved through greater exposure to patients and more bedside tutorials.</p> <p>Conclusions</p> <p>Medical students and residents at this US medical university found neurology difficult. Although this is consistent with prior reports from Europe and Asia, studies in other universities are needed to confirm generalizability of these findings. The optimal opportunity for improvement is during the transition from preclinical to clinical years. Enhanced integration of basic neurosciences and clinical neurology with emphasis on increased bedside tutorials and patient exposure should improve teaching. Studies are needed to quantify the effect of these interventions on confidence of trainees when dealing with patients presenting with neurological complaints.</p

AEO-7 surfactant is “super toxic” and induces severe cardiac, liver and locomotion damage in zebrafish embryos

© 2020, The Author(s). Background: Fatty alcohol polyoxyethylene ether-7 (AEO-7), a non-ionic surfactant, has recently been receiving extensive attention from the ocean pipeline industry for its ability to inhibit corrosion. However, the present lack of information concerning the potential environmental toxicity of AEO-7, especially towards aquatic organisms, is a major impediment to its wider application. Here, we assess potential adverse effects of AEO-7 on zebrafish embryos employing a variety of assays, including (i) a mortality/survival assay which allowed the median lethal concentration (LC50) to be calculated; (ii) a teratogenicity assay on the basis of which the no observed effect concentration (NOEC) was determined; and (iii) specific assays of cardiotoxicity, neurotoxicity (based on locomotion), hematopoietic toxicity (the level of hemoglobin as revealed by o-dianisidine staining) and hepatotoxicity (liver steatosis and yolk retention examined by staining with Oil Red O). Results: AEO-7 caused mortality with a calculated LC50 of 15.35 μg/L, which, according to the U.S. Fish and Wildlife Service (USFWS) Acute Toxicity Rating scale, should be considered “super toxic”. Although at its NOEC (0.8 μg/L), there were no signs of significant teratogenicity, cardiotoxicity, or hemopoiesis toxicity, 3.2 µg/L AEO-7 exerted dramatic detrimental effects on organ development. Conclusion: On the basis of these findings, we recommend that the industrial usage and environmental impact of AEO-7 be re-evaluated and strictly monitored by environmental and public health organizations

Abiotic ammonium formation in the presence of Ni-Fe metals and alloys and its implications for the Hadean nitrogen cycle

Experiments with dinitrogen-, nitrite-, nitrate-containing solutions were conducted without headspace in Ti reactors (200°C), borosilicate septum bottles (70°C) and HDPE tubes (22°C) in the presence of Fe and Ni metal, awaruite (Ni80Fe20) and tetrataenite (Ni50Fe50). In general, metals used in this investigation were more reactive than alloys toward all investigated nitrogen species. Nitrite and nitrate were converted to ammonium more rapidly than dinitrogen, and the reduction process had a strong temperature dependence. We concluded from our experimental observations that Hadean submarine hydrothermal systems could have supplied significant quantities of ammonium for reactions that are generally associated with prebiotic synthesis, especially in localized environments. Several natural meteorites (octahedrites) were found to contain up to 22 ppm Ntot. While the oxidation state of N in the octahedrites was not determined, XPS analysis of metals and alloys used in the study shows that N is likely present as nitride (N3-). This observation may have implications toward the Hadean environment, since, terrestrial (e.g., oceanic) ammonium production may have been supplemented by reduced nitrogen delivered by metal-rich meteorites. This notion is based on the fact that nitrogen dissolves into metallic melts

Metabolic constituents of grapevine and grape-derived products

The numerous uses of the grapevine fruit, especially for wine and beverages, have made it one of the most important plants worldwide. The phytochemistry of grapevine is rich in a wide range of compounds. Many of them are renowned for their numerous medicinal uses. The production of grapevine metabolites is highly conditioned by many factors like environment or pathogen attack. Some grapevine phytoalexins have gained a great deal of attention due to their antimicrobial activities, being also involved in the induction of resistance in grapevine against those pathogens. Meanwhile grapevine biotechnology is still evolving, thanks to the technological advance of modern science, and biotechnologists are making huge efforts to produce grapevine cultivars of desired characteristics. In this paper, important metabolites from grapevine and grape derived products like wine will be reviewed with their health promoting effects and their role against certain stress factors in grapevine physiology

Post-mortem volatiles of vertebrate tissue

Volatile emission during vertebrate decay is a complex process that is understood incompletely. It depends on many factors. The main factor is the metabolism of the microbial species present inside and on the vertebrate. In this review, we combine the results from studies on volatile organic compounds (VOCs) detected during this decay process and those on the biochemical formation of VOCs in order to improve our understanding of the decay process. Micro-organisms are the main producers of VOCs, which are by- or end-products of microbial metabolism. Many microbes are already present inside and on a vertebrate, and these can initiate microbial decay. In addition, micro-organisms from the environment colonize the cadaver. The composition of microbial communities is complex, and communities of different species interact with each other in succession. In comparison to the complexity of the decay process, the resulting volatile pattern does show some consistency. Therefore, the possibility of an existence of a time-dependent core volatile pattern, which could be used for applications in areas such as forensics or food science, is discussed. Possible microbial interactions that might alter the process of decay are highlighted