A Master-Oscillator-Power-Amplifier 2-micron Laser Using Fiber Phase-conjugate Mirror

For the first time, a 2-micron master-oscillator-power-amplifier laser using a fiber based phase conjugation mirror has been demonstrated. The beam quality improvement and 56% of the PCM reflectivity have been achieved

Imaging Autophagy in hiPSC-Derived Midbrain Dopaminergic Neuronal Cultures for Parkinson’s Disease Research

To appreciate the positive or negative impact of autophagy during the initiation and progression of human diseases, the isolation or de novo generation of appropriate cell types is required to support focused in vitro assays. In human neurodegenerative diseases such as Parkinson’s disease (PD), specific subsets of acutely sensitive neurons become susceptible to stress-associated operational decline and eventual cell death, emphasizing the need for functional studies in those vulnerable groups of neurons. In PD, a class of dopaminergic neurons in the ventral midbrain (mDANs) is affected. To study these, human-induced pluripotent stem cells (hiPSCs) have emerged as a valuable tool, as they enable the establishment and study of mDAN biology in vitro. In this chapter, we describe a stepwise protocol for the generation of mDANs from hiPSCs using a monolayer culture system. We then outline how imaging-based autophagy assessment methodologies can be applied to these neurons, thereby providing a detailed account of the application of imaging-based autophagy assays to human iPSC-derived mDAN

Caspase involvement in autophagy

Caspases are a family of cysteine proteases widely known as the principal mediators of the apoptotic cell death response, but considerably less so as the contributors to the regulation of pathways outside cellular demise. In regards to autophagy, the modulatory roles of caspases have only recently begun to be adequately described. In contrast to apoptosis, autophagy promotes cell survival by providing energy and nutrients through the lysosomal degradation of cytoplasmic constituents. Under basal conditions autophagy and apoptosis cross-regulate each other through an elaborate network of interconnections which also includes the interplay between autophagyrelated proteins (ATGs) and caspases. In this review we focus on the effects of this crosstalk at the cellular level, as we aim to concentrate the main observations from research conducted so far on the fine-tuning of autophagy by caspases. Several members of this protease-family have been found to directly interact with key ATGs involved in different tiers across the autophagic cascade. Therefore, we firstly outline the core mechanism of macroautophagy in brief. In an effort to emphasize the importance of the intricate cross-regulation of ATGs and caspases, we also present examples drawn from Drosophila and plant models regarding the contribution of autophagy to apoptotic cell death during normal development

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Nanoparticle-induced neuronal toxicity across placental barriers is mediated by autophagy and dependent on astrocytes

The potential for maternal nanoparticle (NP) exposures to cause developmental toxicity in the fetus without the direct passage of NPs has previously been shown, but the mechanism remained elusive. We now demonstrate that exposure of cobalt and chromium NPs to BeWo cell barriers, an in vitro model of the human placenta, triggers impairment of the autophagic flux and release of interleukin-6. This contributes to the altered differentiation of human neural progenitor cells and DNA damage in the derived neurons and astrocytes. Crucially, neuronal DNA damage is mediated by astrocytes. Inhibiting the autophagic degradation in the BeWo barrier by overexpression of the dominant-negative human ATG4BC74A significantly reduces the levels of DNA damage in astrocytes. In vivo, indirect NP toxicity in mice results in neurodevelopmental abnormalities with reactive astrogliosis and increased DNA damage in the fetal hippocampus. Our results demonstrate the potential importance of autophagy to elicit NP toxicity and the risk of indirect developmental neurotoxicity after maternal NP exposure

Avaliação da qualidade pós-colheita e conservação de cebolinhas submetidas ao hidroresfriamento

Spring onions are part of the Alliaceae family and is one of the most used and traded vegetables in the world, with an essentially seasoning nature. However, they present high perishability and susceptibility to water loss, which reduces the useful life of the product, both on shelves (benefit for the producer) and in refrigerators (benefit for the consumer). The hydrocooling method, which consists of the immersion of the product in a mixture of water and ice, is a good alternative for field heat removal and favouring the humidity of vegetable products, besides being associated to its sanitation process. Considering what has been said, this paper aimed to check the efficiency and the effects of hydrocooling on the post-harvest quality and conservation of spring onions, through analyses of quality parameters such as fresh mass loss, total soluble solids (TSS), pH, total titratable acidity (TTA), chlorophyll index, TSS/TTA ratio, respiration, darkening index, and biospeckle through the moment of inertia method, aiming to determine the best hydrocooling application time at 5 ºC. Hydrocooling showed efficient, mainly on the mass loss control and on the commercial visual aspects, with 10 minutes as the most indicated application timeA cebolinha pertencente à família das aliáceas (Alliaceae) é uma das hortaliças mais utilizadas e comercializadas do mundo, com carácter essencialmente condimentar. Entretanto, apresenta alta perecibilidade e suscetibilidade à perda de água, o que ocasiona redução da vida útil do produto, fazendo-se necessário o uso de técnicas de pós-colheita, com o intuito de diminuir a atividade metabólica e prolongar a vida útil do mesmo, tanto na prateleira (benefício ao produtor) como na geladeira (benefício ao consumidor). O método do hidroresfriamento que consiste na imersão do produto em uma mistura de água e gelo, se apresenta como uma boa alternativa para retirada do calor de campo e favorecimento da umidade dos produtos hortícolas, além de poder ser associado com o processo de sanitização dos mesmos. Diante do exposto, o presente trabalho teve por objetivo verificar a eficiência e os efeitos do hidroresfriamento na qualidade e conservação pós-colheita da cebolinha, através das análises de parâmetros de qualidade como perda de massa fresca, sólidos solúveis totais (SST), pH, acidez total titulável (ATT), índice de clorofila, relação SST/ATT, respiração, índice de escurecimento e biospeckle pelo método do momento de inércia, visando determinar o melhor tempo de aplicação do hidroresfriamento a 5 ºC. O hidroresfriamento se mostrou eficiente, principalmente, no controle de perda de massa e nos aspectos visuais comerciais, sendo o tempo mais indicado de aplicação o de 10 minuto