Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin Photoaging

Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.This research was supported by national funds through FCT, Foundation for Science and Technology, within the scope of UIDB/04423/2020 and UIDP/04423/2020 under the project PTDC/SAU-PUB/28736/2017 (reference POCI-01-0145-FEDER-028736), cofinanced by COMPETE 2020, Portugal 2020 and the European Union through the ERDF and by FCT through national funds, as well as CHIRALBIOACTIVE-PI-3RL-IINFACTS-2019, and supported by the Applied Molecular Biosciences Unit-UCIBIO which is financed by national funds from FCT/MCTES (UID/Multi/04378/2019). Thanks are also due to FCT, the European Union, QREN, FEDER, COMPETE, by funding cE3c center (Ref. UID/BIA/00329/2019) and Direcao Regional da Ciencia e Tecnologia (Azores Government) by funding Azorean Biodiversity Group.info:eu-repo/semantics/publishedVersio

What do Undergraduate Engineering Students and Preservice Teachers Learn by Collaborating and Teaching Engineering and Coding through Robotics?

This research paper presents preliminary results of an NSF-supported interdisciplinary collaboration between undergraduate engineering students and preservice teachers. The fields of engineering and elementary education share similar challenges when it comes to preparing undergraduate students for the new demands they will encounter in their profession. Engineering students need interprofessional skills that will help them value and negotiate the contributions of various disciplines while working on problems that require a multidisciplinary approach. Increasingly, the solutions to today\u27s complex problems must integrate knowledge and practices from multiple disciplines and engineers must be able to recognize when expertise from outside their field can enhance their perspective and ability to develop innovative solutions. However, research suggests that it is challenging even for professional engineers to understand the roles, responsibilities, and integration of various disciplines, and engineering curricula have traditionally left little room for development of non-technical skills such as effective communication with a range of audiences and an ability to collaborate in multidisciplinary teams. Meanwhile, preservice teachers need new technical knowledge and skills that go beyond traditional core content knowledge, as they are now expected to embed engineering into science and coding concepts into traditional subject areas. There are nationwide calls to integrate engineering and coding into PreK-6 education as part of a larger campaign to attract more students to STEM disciplines and to increase exposure for girls and minority students who remain significantly underrepresented in engineering and computer science. Accordingly, schools need teachers who have not only the knowledge and skills to integrate these topics into mainstream subjects, but also the intention to do so. However, research suggests that preservice teachers do not feel academically prepared and confident enough to teach engineering-related topics. This interdisciplinary project provided engineering students with an opportunity to develop interprofessional skills as well as to reinforce their technical knowledge, while preservice teachers had the opportunity to be exposed to engineering content, more specifically coding, and develop competence for their future teaching careers. Undergraduate engineering students enrolled in a computational methods course and preservice teachers enrolled in an educational technology course partnered to plan and deliver robotics lessons to fifth and sixth graders. This paper reports on the effects of this collaboration on twenty engineering students and eight preservice teachers. T-tests were used to compare participants’ pre-/post- scores on a coding quiz. A post-lesson written reflection asked the undergraduate students to describe their robotics lessons and what they learned from interacting with their cross disciplinary peers and the fifth/sixth graders. Content analysis was used to identify emergent themes. Engineering students’ perceptions were generally positive, recounting enjoyment interacting with elementary students and gaining communication skills from collaborating with non-technical partners. Preservice teachers demonstrated gains in their technical knowledge as measured by the coding quiz, but reported lacking the confidence to teach coding and robotics independently of their partner engineering students. Both groups reported gaining new perspectives from working in interdisciplinary teams and seeing benefits for the fifth and sixth grade participants, including exposing girls and students of color to engineering and computin

KDR receptor: A key marker defining hematopoietic stem cells

Studies on pluripotent hematopoietic stem cells (HSCs) have been hindered by lack of a positive marker, comparable to the CD34 marker of hematopoietic progenitor cells (HPCs). In human postnatal hematopoietic tissues, 0.1 to 0.5% of CD34+cells expressed vascular endothelial growth factor receptor 2 (VEGFR2, also known as KDR). Pluripotent HSCs were restricted to the CD34+KDR+cell fraction. Conversely, lineage-committed HPCs were in the CD34+KDR-subset. On the basis of limiting dilution analysis, the HSC frequency in the CD34+KDR+fraction was 20 percent in bone marrow (BM) by mouse xenograft assay and 25 to 42 percent in BM, peripheral blood, and cord blood by 12-week long-term culture (LTC) assay. The latter values rose to 53 to 63 percent in LTC supplemented with VEGF and to greater than 95 percent for the cell subfraction resistant to growth factor starvation. Thus, KDR is a positive functional marker defining stem cells and distinguishing them from progenitors

Plasma-Derived Extracellular Vesicles as Potential Biomarkers in Heart Transplant Patient with Chronic Chagas Disease

Chagas disease is emerging in countries to which it is not endemic. Biomarkers for earlier therapeutic response assessment in patients with chronic Chagas disease are needed. We profiled plasma-derived extracellular vesicles from a heart transplant patient with chronic Chagas disease and showed the potential of this approach for discovering such biomarkers

Agricultura orgânica em áreas urbanas e periurbanas com base na agroecologia.

A agricultura orgânica com base na agroecologia é o mote tecnológico adequado à realidade dos agroecossistemas urbanos. Este artigo ressalta a necessidade de se desenvolver tecnologias e insumos específicos. A partir de experiências com agricultura urbana em diferentes países em desenvolvimento, evidencia-se a necessidade de se buscar capacidades locais e apoio do poder público, especialmente nas iniciativas da sociedade organizada e mobilizada para a produção agrícola urbana

Altered Hypercoagulability Factors in Patients with Chronic Chagas Disease: Potential Biomarkers of Therapeutic. Response

Thromboembolic events were described in patients with Chagas disease without cardiomyopathy. We aim to confirm if there is a hypercoagulable state in these patients and to determine if there is an early normalization of hemostasis factors after antiparasitic treatment. Ninety-nine individuals from Chagas disease-endemic areas were classified in two groups: G1, with T.cruzi infection (n = 56); G2, healthy individuals (n = 43). Twenty-four hemostasis factors were measured at baseline. G1 patients treated with benznidazole were followed for 36 months, recording clinical parameters and performance of conventional serology, chemiluminescent enzyme-linked immunosorbent assay (trypomastigote-derived glycosylphosphatidylinositol-anchored mucins), quantitative polymerase chain reaction, and hemostasis tests every 6-month visits. Prothrombin fragment 1+2 (F1+2) and endogenous thrombin potential (ETP) were abnormally expressed in 77% and 50% of infected patients at baseline but returned to and remained at normal levels shortly after treatment in 76% and 96% of cases, respectively. Plasmin-antiplasmin complexes (PAP) were altered before treatment in 32% of G1 patients but normalized in 94% of cases several months after treatment. None of the patients with normal F1+2 values during follow-up had a positive qRT-PCR result, but 3/24 patients (13%) with normal ETP values did. In a percentage of chronic T. cruzi infected patients treated with benznidazole, altered coagulation markers returned into normal levels. F1+2, ETP and PAP could be useful markers for assessing sustained response to benznidazole

Interactions between hypoxia tolerance and food deprivation in Amazonian oscars, Astronotus ocellatus

Oscars are often subjected to a combination of low levels of oxygen and fasting during nest-guarding on Amazonian floodplains. We questioned whether this anorexia would aggravate the osmo-respiratory compromise. We compared fed and fasted oscars (1014 days) in both normoxia and hypoxia (1020 Torr, 4 h). Routine oxygen consumption rates (MO2) were increased by 75% in fasted fish, reflecting behavioural differences, whereas fasting improved hypoxia resistance and critical oxygen tensions (Pcrit) lowered from 54 Torr in fed fish to 34 Torr when fasting. In fed fish, hypoxia reduced liver lipid stores by approximately 50% and total liver energy content by 30%. Fasted fish had a 50% lower hepatosomatic index, resulting in lower total liver protein, glycogen and lipid energy stores under normoxia. Compared with hypoxic fed fish, hypoxic fasted fish only showed reduced liver protein levels and even gained glycogen (+50%) on a per gram basis. This confirms the hypothesis that hypoxia-tolerant fish protect their glycogen stores as much as possible as a safeguard for more prolonged hypoxic events. In general, fasted fish showed lower hydroxyacylCoA dehydrogenase activities compared with fed fish, although this effect was only significant in hypoxic fasted fish. Energy stores and activities of enzymes related to energy metabolism in muscle or gills were not affected. Branchial Na+ uptake rates were more than two times lower in fed fish, whereas Na+ efflux was similar. Fed and fasted fish quickly reduced Na+ uptake and efflux during hypoxia, with fasting fish responding more rapidly. Ammonia excretion and K+ efflux were reduced under hypoxia, indicating decreased transcellular permeability. Fasted fish had more mitochondria-rich cells (MRC), with larger crypts, indicating the increased importance of the branchial uptake route when feeding is limited. Gill MRC density and surface area were greatly reduced under hypoxia, possibly to reduce ion uptake and efflux rates. Density of mucous cells of normoxic fasted fish was approximately fourfold of that in fed fish. Overall, a 1014 day fasting period had no negative effects on hypoxia tolerance in oscars, as fasted fish were able to respond more quickly to lower oxygen levels, and reduced branchial permeability effectively. © 2013. Published by The Company of Biologists Ltd

Análise da estrutura fatorial dos Testes de Torrance em estudantes portugueses

In order to verify the factorial structures of the Torrance verbal and figural tests, two activities of each instrument were applied with 193 students from the 10th and 12th years of education in Portugal. We tried to demonstrate that the collinearity of the fluency and flexibility variables could create methodological artifacts that hinder the understanding of the internal structure underlying the test. The principal component analysis without control of collinearity indicated a solution composed of four basic factors that separeted activities. Controlling for collinearity, we found a new solution, which also contained four factors that, unlike the previous result, grouped variables with similar processes but of different activities. The verbal and figural content is also an important element in the factor structure. This new arrangement makes more sense with the theory that underlies the instruments separating the different processes and content which are being measured by the activities.Com a finalidade de verificar a estrutura fatorial dos testes de Torrance, duas atividades verbais e duas figurais foram aplicadas em 193 estudantes do 10º e 12º ano do ensino secundário de Portugal. Tentou-se demonstrar que a colinearidade das variáveis fluência e flexibilidade podem criar artefatos metodológicos que dificultam o entendimento da estrutura interna subjacente ao teste. A análise fatorial dos componentes principais, sem controle da colinearidade, indicou uma solução composta por quatro fatores que separam basicamente as atividades. Controlando-se a colinearidade, encontrou-se uma nova solução, também composta por quatro fatores, que, diferentemente da anterior, organizou variáveis com processos semelhantes, mas de diferentes atividades. O tipo de conteúdo, verbal e figural, mostrou-se ainda um importante elemento na organização dos fatores. Esse novo arranjo fez mais sentido diante da teoria que embasa os instrumentos, ao separar os diferentes processos e conteúdos por eles avaliados