Catalytic upgrading of microalgal hydrothermal oil: Impact of algae species and catalyst for biofuel production

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Fast Label-Free Nanoscale Composition Mapping of Eukaryotic Cells Via Scanning Dielectric Force Volume Microscopy and Machine Learning

Mapping the biochemical composition of eukaryotic cells without the use of exogenous labels is a long-sought objective in cell biology. Recently, it has been shown that composition maps on dry single bacterial cells with nanoscale spatial resolution can be inferred from quantitative nanoscale dielectric constant maps obtained with the scanning dielectric microscope. Here, it is shown that this approach can also be applied to the much more challenging case of fixed and dry eukaryotic cells, which are highly heterogeneous and show micrometric topographic variations. More importantly, it is demonstrated that the main bottleneck of the technique (the long computation times required to extract the nanoscale dielectric constant maps) can be shortcut by using supervised neural networks, decreasing them from weeks to seconds in a wokstation computer. This easy-to-use data-driven approach opens the door for in situ and on-the-fly label free nanoscale composition mapping of eukaryotic cells with scanning dielectric microscopy

Nanoscale mapping of the conductivity and interfacial capacitance of an electrolyte-gated organic field-effect transistor under operation

Versió postprint del document publicat a: https://doi.org/10.1002/adfm.202008032Probing nanoscale electrical properties of organic semiconducting materials at the interface with an electrolyte solution under externally applied voltages is key in the field of organic bioelectronics. It is demonstrated that the conductivity and interfacial capacitance of the active channel of an electrolyte-gated organic field‐effect transistor (EGOFET) under operation can be probed at the nanoscale using scanning dielectric microscopy in force detection mode in liquid environment. Local electrostatic force versus gate voltage transfer characteristics are obtained on the device and correlated with the global current–voltage transfer characteristics of the EGOFET. Nanoscale maps of the conductivity of the semiconducting channel show the dependence of the channel conductivity on the gate voltage and its variation along the channel due to the space charge limited conduction. The maps reveal very small electrical heterogeneities, which correspond to local interfacial capacitance variations due to an ultrathin non-uniform insulating layer resulting from a phase separation in the organic semiconducting blend. Present results offer insights into the transduction mechanism at the organic semiconductor/electrolyte interfaces at scales down to ≈100 nm, which can bring substantial optimization of organic electronic devices for bioelectronic applications such as electrical recording on excitable cells or label-free biosensing

Clinical Usefulness Of Sars-Cov-2 Rapid Antigen Tests In Adults During High Prevalence Community Outbreaks

We evaluated performance of Abbott PanBio® COVID-19 Rapid Antigen Test Device (RATD) to detect SARS-CoV-2 infection in adults during high prevalence COVID-19 outbreaks. We found high accuracy in correct diagnosis (88% CI 85-91%, p<0.05) regardless of gender, presence of symptoms, disease timeline. Test sensitivity appeared to increase with age, specificity seemed to decline. Best diagnostic accuracy was obtained in middle-aged adults (94% CI 89-97%, p<0.05), but remained high through all ages. These results support RATD as a reliable measure to determine isolation of infected individuals during outbreaks. More studies are needed to assess RATD performance in low prevalence post-vaccination scenarios.http://deepblue.lib.umich.edu/bitstream/2027.42/166596/1/AFM-177-21_PP.pdfDescription of AFM-177-21_PP.pdf : Main ArticleSEL

The AAA plus chaperone VCP disaggregates Tau fibrils and generates aggregate seeds in a cellular system

Amyloid-like aggregates of the microtubule-associated protein Tau are associated with several neurodegenerative disorders including Alzheimer's disease. The existence of cellular machinery for the removal of such aggregates has remained unclear, as specialized disaggregase chaperones are thought to be absent inmammalian cells. Here we show in cell culture and in neurons that the hexameric ATPase valosin-containing protein (VCP) is recruited to ubiquitylated Tau fibrils, resulting in their efficient disaggregation. Aggregate clearance depends on the functional cooperation of VCP with heat shock 70 kDa protein (Hsp70) and the ubiquitin-proteasome machinery. While inhibition of VCP activity stabilizes large Tau aggregates, disaggregation by VCP generates seeding-active Tau species as byproduct. These findings identify VCP as a core component of the machinery for the removal of neurodegenerative disease aggregates and suggest that its activity can be associated with enhanced aggregate spreading in tauopathies

Legume Genomics and Breeding

This chapter contains sections titled; Introduction; Constraints in Crop Production; Genomic Resources in Legumes;Trait Mapping and Marker-Assisted Selection; Summary and Prospects; Acknowledgments; Literature Cite

Caracterización morfológica de la colección de Cyphomandra betacea (Cav.) Sendt de la Universidad de Nariño

Cincuenta introducciones de la colección de tomate de árbol, C. betacea, de la Universidad de Nariño fueron caracterizadas morfológicamente durante el periodo de junio de 2009 - diciembre de 2010 mediante descriptores altamente discriminativos, bajo condiciones del municipio de Pasto en la vereda Caldera Bajo, que presenta una temperatura de 18 °C, 1600 mm de precipitación al año y altura de 1900 m.s.n.m. El Análisis de Componentes Principales indicó que los cuatro primeros factores, explicaron el 84,07% de la variabilidad total y la clasificación jerárquica identificó cuatro clases que junto con el ACP revelaron una alta contribución de los caracteres a la variación existente. El Análisis de Correspondencias Múltiples, reveló la formación de cinco factores que explicaron el 75,84% de la variación total de la población. Las características que más contribuyeron a la conformación de los factores fueron el Color de brotes apicales, el color de la nervadura en la haz y en el envés de la hoja, color de la hoja en la haz y en el envés, color del cáliz de la flor, el hábito de crecimiento de la copa, color del fruto maduro, forma del fruto, densidad de la copa y tamaño del fruto. El Análisis de Clasificación para caracteres cualitativos determinó tres grupos, diferenciados principalmente por el color de la placenta y tamaño de fruto

Depth mapping of metallic nanowire polymer nanocomposites by scanning dielectric microscopy

Polymer nanocomposite materials based on metallic nanowires are widely investigated as transparent and flexible electrodes or as stretchable conductors and dielectrics for biosensing. Here we show that Scanning Dielectric Microscopy (SDM) can map the depth distribution of metallic nanowires within the nanocomposites in a non-destructive way. This is achieved by a quantitative analysis of sub-surface electrostatic force microscopy measurements with finite-element numerical calculations. As an application we determined the three-dimensional spatial distribution of around 50 nm diameter silver nanowires in 100 - 250 nm thick gelatin films. The characterization is done both under dry ambient conditions, where gelatin shows a relatively low dielectric constant, epsilon around 5, and under humid ambient conditions, where its dielectric constant increases up to epsilon around 14. The present results show that SDM can be a valuable non-destructive subsurface characterization technique for nanowire-based nanocomposite materials, which can contribute to the optimization of these materials for applications in fields such as wearable electronics, solar cell technologies or printable electronics