Immune System Modulation Produced by Ultraviolet Radiation

Exposure to ultraviolet radiation (UVr) contained in sunlight is a major cause of skin illness such as sunburn, aging and cancer. UVr triggers local effects on the skin, which involve local inflammation, tissue remodeling, regulatory cytokines release and migration of dendritic cells (DCs). However, these localized effects on the exposed area are not the only ones that take place after sun or UVr exposure. A less known effect of UVr is the modulation of systemic immunity, through the generation of specific regulatory cells. These cells are induced, at least in part, by skin-migrating tolerogenic DCs. Moreover, bone marrow cell precursors can also be biased to a tolerogenic or suppressor phenotype. The sunlight- or UVr-induced immune system modulation can cause skin disorders like skin cancer and cutaneous photosensitivity in Lupus, but it also may be useful to treat cutaneous pathologies such as psoriasis and vitiligo. Moreover, the systemic immunosuppressor effect of UVr exposure may also be useful to treat autoimmunity of internal organs. Finally, as an inducer of cutaneous inflammatory response, UV phototherapy may also be useful in the treatment of cutaneous infections. Overall, UVr has profound immunomodulatory capacity that can be beneficial or deleterious for human health

Effects of Nonthermal Plasma (NTP) on the Growth and Quality of Baby Leaf Lettuce (Lactuca sativa var. acephala Alef.) Cultivated in an Indoor Hydroponic Growing System

The aim of this research was to develop an effective protocol for the application of nonther-mal plasma (NTP) technology to the hydroponic nutrient solution, and to investigate its effects on the growth and quality of baby leaf lettuce (Lactuca sativa var. acephala Alef.) grown in a hydroponic growing system (HGS) specifically designed for indoor home cultivation. Four HGSs were placed in separate growth chambers with temperature of 24 ± 1◦ C and relative humidity of 70 ± 5%). Lettuce plants were grown for nine days in nutrient solutions treated with NTP for 0 (control) to 120 s every hour. Results of the first experiments showed that the optimal operating time of NTP was 120 s h−1 . Fresh leaf biomass was increased by the 60 and 120 s NTP treatments compared to the control. Treating the nutrient solution with NTP also resulted in greater leaf content of total chloro-phylls, carotenoids, total phenols, and total antioxidant capacity. NTP also positively influenced chlorophyll a fluorescence in Photosystem I (PSI) and photosynthetic electron transport. These results revealed that the NTP treatment of the nutrient solution could improve the production and quality of hydroponically grown baby leaf lettuce

Improved Method for In Vitro Secondary Amastigogenesis of Trypanosoma cruzi: Morphometrical and Molecular Analysis of Intermediate Developmental Forms

Trypanosoma cruzi undergoes a biphasic life cycle that consists of four alternate developmental stages. In vitro conditions to obtain a synchronic transformation and efficient rates of pure intermediate forms (IFs), which are indispensable for further biochemical, biological, and molecular studies, have not been reported. In the present study, we established an improved method to obtain IFs from secondary amastigogenesis. During the transformation kinetics, we observed progressive decreases in the size of the parasite body, undulating membrane and flagellum that were concomitant with nucleus remodeling and kinetoplast displacement. In addition, a gradual reduction in parasite movement and acquisition of the amastigote-specific Ssp4 antigen were observed. Therefore, our results showed that the in vitro conditions used obtained large quantities of highly synchronous and pure IFs that were clearly distinguished by morphometrical and molecular analyses. Obtaining these IFs represents the first step towards an understanding of the molecular mechanisms involved in amastigogenesis

Aprendendo a ensinar em tempos de pandemia COVID-19: nossa experiência na Universidad de Buenos Aires

The aim of this text, is to describe our teaching role in times of pandemic, recounting how we discovered strategies to teach in times of virtual presence, as well as the search for new experiences in teacher training, highlighting the importance of how we turn them into an opportunity for our self-improvement. Procedure: We will discuss the strengths and weaknesses that we found while we were going through this new path of online teaching, set up for the first time in the undergraduate courses of our University. Conclusion: The main educational accomplishments we achieved during the pandemic course were, to establish a true flipped classroom, and to use ludic strategies that were not common in our classes. On the other hand, we highlight the close contact we fulfilled with our students, which led them to recognize with high opinion our study methodology, the knowledge acquired, the strategies used, and our commitment and teaching predisposition.El objetivo del presente trabajo fue describir nuestro rol docente en tiempos de pandemia, relatar cómo fue nuestro descubrimiento de estrategias para enseñar en tiempos de no presencialidad, así como la búsqueda de nuevas experiencias de formación docente, y resaltar la importancia de cómo las convertimos en una oportunidad de mejora sobre nuestra labor. Procedimiento: Discutiremos las fortalezas y debilidades que fuimos encontrando mientras transitábamos este nuevo camino de enseñanza online, establecido por primera vez en las carreras de grado de nuestra Universidad. Conclusiones: Los principales logros docentes que alcanzamos durante la cursada en pandemia fueron instaurar una verdadera aula invertida y emplear estrategias lúdicas que no eran habituales en nuestras clases. Por otra parte, destacamos el estrecho contacto con nuestros alumnos lo cual condujo a un alto reconocimiento por parte de ellos en cuanto a nuestra metodología de cursada, el conocimiento adquirido, las estrategias utilizadas y nuestro compromiso y predisposición docente.O propósito deste texto, é descrever nosso papel docente em tempos de pandemia, relatando como foi a nossa descoberta de estratégias para ensinar aulas não presenciais, assim como a busca por novas experiências na formação de professores, destacando-se a importância de como as transformamos em oportunidades de melhoria sobre nosso trabalho. Proceso: Discutiremos os pontos fracos e fortes encontrados, enquanto percorremos este novo caminho de ensinamento on-line, estabelecido pela primeira vez nos cursos de graduação da nossa Universidade. Conclusão: As principais conquistas educacionais que alcançamos durante a pandemia, foram criar uma verdadeira aula invertida e empregar estratégias lúdicas que não eram comuns em nossas aulas. Por outro lado, destacamos o estreito contato com nossos alunos o que permitiu um elevado reconhecimento por parte dos mesmos quanto à nossa metodologia de estudo, os conhecimentos adquiridos, as estratégias utilizadas, nosso empenho e predisposição pedagógica

NiO–CGO in situ nanocomposite attainment: One step synthesis

AbstractThe CeO2-based electrolyte low temperature SOFCs require special electrodes with a higher performance and compatibility. The performance of the CeO2-based composite anodes depends on microstructural features such as particle size, tripe phase boundaries (TPB), surface area, and percolation. Some of the primary parameter can be manipulated during the materials synthesis. In this work the compound NiO–Ce0.9Gd0.1O1.95 (NiO–CGO), used as anode in SOFC, was synthesized by two different processes. Both of them are based on the polymeric precursor method. Characterized by simultaneous thermogravimetry-differential thermal analysis, X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy and dilatometry. The refinement of the XRD data indicated that the composite sample synthesized by the process called “one step synthesis” produced smaller crystallite size in comparison to the sample attained by the two steps process. Simple preliminary performance tests were done with single cells in which such I–V curves indicated that the cell with one step anode had better performance. “One step synthesis” product, in situ nanocomposite, presented similar fine grained particle sizes for both phases Ni and CGO, which would be beneficial to the electrochemical activity, also indicated by first performance tests

Lateral Orbitofrontal Cortex Involvement in Initial Negative Aesthetic Impression Formation

It is well established that aesthetic appreciation is related with activity in several different brain regions. The identification of the neural correlates of beauty or liking ratings has been the focus of most prior studies. Not much attention has been directed towards the fact that humans are surrounded by objects that lead them to experience aesthetic indifference or leave them with a negative aesthetic impression. Here we explore the neural substrate of such experiences. Given the neuroimaging techniques that have been used, little is known about the temporal features of such brain activity. By means of magnetoencephalography we registered the moment at which brain activity differed while participants viewed images they considered to be beautiful or not. Results show that the first differential activity appears between 300 and 400 ms after stimulus onset. During this period activity in right lateral orbitofrontal cortex (lOFC) was greater while participants rated visual stimuli as not beautiful than when they rated them as beautiful. We argue that this activity is associated with an initial negative aesthetic impression formation, driven by the relative hedonic value of stimuli regarded as not beautiful. Additionally, our results contribute to the understanding of the nature of the functional roles of the lOFC