Protective effect of glutathione on Escherichia coli cells upon lethal heat stress

Heat treatments are widely used by the food industry to obtain safe and stable products, therefore a deeper knowledge of its mode of action on microorganisms would allow a better profit of this technology. Heat shows a multitarget mechanism of action on bacteria, affecting various cellular structures, and causing unbalances in several homeostatic parameters. The aim of this work was to study the effect of glutathione on bacterial survival against heat treatments, in order to acquire knowledge about the mode of action of heat on bacterial cells. Cells were treated in presence or absence of added glutathione and the level of inactivation, soluble protein concentration, enzymatic activities, intracellular ROS level and membrane damages were studied. Results showed that glutathione protected microorganisms against heat inactivation. Moreover, glutathione in the treatment medium preserved intracellular enzyme activity, membrane structure and reduced ROS detection. Besides, glutathione decreased sublethal injury in E. coli. Data presented in this work add new knowledge about bacterial inactivation and survival by heat

Effective in Vitro Photokilling by Cell-Adhesive Gold Nanorods

Upon excitation of their localized surface plasmon resonance (LSPR) band, gold nanorods (AuNRs) show a characteristic light-to-heat transduction, a useful and versatile property for a range of biomedical applications such as photothermal therapy, drug delivery, optoacoustic imaging and biosensing, among others. Nanoparticle (NP)-mediated photothermal therapy (PTT) rests on the ability of nanomaterials to convert light energy into heat and can currently be considered as a promising method for selectively destroying tumor cells by (photo)-thermoablation. One inherent limitation to NP-mediated PTT is that the nanoparticles must arrive at the site of action to exert their function and this typically involves cellular internalization. Here we report the use of the Keggin-type polyoxometalate (POM) phosphotungstic acid (PTA) as an inorganic gelling agent for the encapsulation of plasmonic gold nanorods (AuNRs) inside a biocompatible and cell-adhesive chitosan hydrogel matrix. These functional sub-micrometric containers are non-cytotoxic and present the ability to adhere to the cytoplasmic membranes of cells avoiding any need for cellular internalization, rendering them as highly efficient thermoablating agents of eukaryotic cells in vitro

Live 5D hyper-spectral fluorescence imaging of developing zebrafish

The advent of fluorescent proteins (FP) has revolutionized the use of fluorescence microscopy in biology. The color palette of fluorescent proteins has grown over the years covering the entire spectrum from blue to near infra‐red. The use of multiple FPs has enabled studies of spatio‐temporal interaction of proteins, cells and tissues in vivo within living cells or developing embryos. Multiple labels have been imaged within the same sample, however, timelapse imaging of multiple labels remains challenging. Limiting factors such as noise, photo‐bleaching and ‐toxicity greatly compromise signal quality and throughput can be limited by the time required to unmix multiple labels. In this work, we report a method for rapidly denoising and unmixing multiple spectrally overlapping fluorophores while maintaining reduced negative photo‐effects, in a low signal‐to‐noise regime. We successfully applied the method to 4D datasets of Zebrafish embryos co‐expressing multiple labels, separating a total of 7 different FPs and intrinsic tissues autofluorescences, unmixing. Taking advantage of the technique’s enhanced signal collection and fast processing, we expanded the multi‐dimensionality to include time, obtaining 5D datasets (XYZ,time,label), which often fails in other techniques due to the challenges of photo‐damage and bleaching. We successfully performed long‐term imaging vessel sprouts transgenically labeled zebrafish embryos(Tg(ubiq: membrane‐Cerulean‐2a‐H2B‐ tdTomato);Tg(kdrl:eGFP), expressing fusion proteins of two endosome components, Rab9 and Rab11 (YFP and mCherry respectively). The rapid processing and denoising properties of our approach permitted the clean separation of the FP signals from one‐another and from autofluorescence, using low laser power that allowed for unaffected development, permitting 5D imaging of 7 clearly distinctive components

Avaliação de genótipos de grão de bico em cultivo de sequeiro nas condições de cerrado.

O presente trabalho teve o objetivo de estimar o potencial de cultivo de grão de bico quando submetido a regime de baixa umidade no solo (sequeiro) e identificar genótipos com melhores características morfoagronômicas e de rendimento

Control of parameters of a porcine artificial insemination center

El uso de la inseminación artificial en España ha experimentado un gran crecimiento en estos últimos años. Conjuntamente ha crecido el número de centros de inseminación artificial (CIA) independientes o adosados a las explotaciones. Para rentabilizar al máximo dichos centros, se hace imprescindible una buena gestión, para el control de las condiciones ambientales donde se alojan los verracos, el estatus sanitario de los mismos, así como un seguimiento de la producción y calidad del semen. Con el fin de obtener dosis seminales con calidad y concentración adecuadas se pueden aplicar factores de corrección, en base a los diferentes parámetros espermáticos posibles de evaluar en un CIA, y así obtener un número adecuado de dosis inseminantes de cada verraco Así mismo, se hace necesario -realizar la programación del trabajo diario y maximizar la rentabilidad, controlando el ritmo de extracción de semen y optimizando el balance de dosis producidas, vendidas y desechadas. Cabe remarcar que la buena gestión de un CIA se facilita con el uso de programas informáticos.Artificial insemination has greatly developed in Spain in the past years. At the same time the number of artificial insemination centres (MC) has increased within the farms and independently. Good management is essential to render these centres profitable. Important factors are: environmental control, housing of the animals, health status and production and quality of semen. In order to get semen of high quality, correction factors based on the parameters which can be applied to semen evaluation in an AIC may be used. It is advisable tu establish a daily routine tu maximize rentability, control the collection rate and tu optimize the balance between semen obtained sold and wasted. Informatization of the AIC makes a good management easier.Facultad de Ciencias Veterinaria

Control of parameters of a porcine artificial insemination center

El uso de la inseminación artificial en España ha experimentado un gran crecimiento en estos últimos años. Conjuntamente ha crecido el número de centros de inseminación artificial (CIA) independientes o adosados a las explotaciones. Para rentabilizar al máximo dichos centros, se hace imprescindible una buena gestión, para el control de las condiciones ambientales donde se alojan los verracos, el estatus sanitario de los mismos, así como un seguimiento de la producción y calidad del semen. Con el fin de obtener dosis seminales con calidad y concentración adecuadas se pueden aplicar factores de corrección, en base a los diferentes parámetros espermáticos posibles de evaluar en un CIA, y así obtener un número adecuado de dosis inseminantes de cada verraco Así mismo, se hace necesario -realizar la programación del trabajo diario y maximizar la rentabilidad, controlando el ritmo de extracción de semen y optimizando el balance de dosis producidas, vendidas y desechadas. Cabe remarcar que la buena gestión de un CIA se facilita con el uso de programas informáticos.Artificial insemination has greatly developed in Spain in the past years. At the same time the number of artificial insemination centres (MC) has increased within the farms and independently. Good management is essential to render these centres profitable. Important factors are: environmental control, housing of the animals, health status and production and quality of semen. In order to get semen of high quality, correction factors based on the parameters which can be applied to semen evaluation in an AIC may be used. It is advisable tu establish a daily routine tu maximize rentability, control the collection rate and tu optimize the balance between semen obtained sold and wasted. Informatization of the AIC makes a good management easier.Facultad de Ciencias Veterinaria

Hyperspectral phasor analysis enables multiplexed 5D in vivo imaging

Time-lapse imaging of multiple labels is challenging for biological imaging as noise, photobleaching and phototoxicity compromise signal quality, while throughput can be limited by processing time. Here, we report software called Hyper-Spectral Phasors (HySP) for denoising and unmixing multiple spectrally overlapping fluorophores in a low signal-to-noise regime with fast analysis. We show that HySP enables unmixing of seven signals in time-lapse imaging of living zebrafish embryos

Kinetic and stoichiometric characterization of anoxic sulfideoxidation by SO-NR mixed cultures from anoxic biotrickling filters.

Monitoring the biological activity in biotrickling filters is difficult since it implies estimating biomass concentration and its growth yield, which can hardly be measured in immobilized biomass systems. In this study, the characterization of a sulfide-oxidizing nitrate-reducing biomass obtained from an anoxic biotrickling filter was performed through the application of respirometric and titrimetric techniques. Previously, the biomass was maintained in a continuous stirred tank reactor under steady-state conditions resulting in a growth yield of 0.328±0.045 g VSS/g S. To properly assess biological activity in respirometric tests, abiotic assays were conducted to characterize the stripping of CO2 and sulfide. The global mass transfer coefficient for both processes was estimated. Subsequently, different respirometric tests were performed: (1) to solve the stoichiometry related to the autotrophic denitrification of sulfide using either nitrate or nitrite as electron acceptors, (2) to evaluate the inhibition caused by nitrite and sulfide on sulfide oxidation, and (3) to propose, calibrate, and validate a kinetic model considering both electron acceptors in the overall anoxic biodesulfurization process. The kinetic model considered a Haldane-type equation to describe sulfide and nitrite inhibitions, a non-competitive inhibition to reflect the effect of sulfide on the elemental sulfur oxidation besides single-step denitrification since no nitrite was produced during the biological assays

Compensating control participants when the intervention is of significant value: experience in Guatemala, India, Peru and Rwanda

The Household Air Pollution Intervention Network (HAPIN) trial is a randomised controlled trial in Guatemala, India, Peru and Rwanda to assess the health impact of a clean cooking intervention in households using solid biomass for cooking. The HAPIN intervention—a liquefied petroleum gas (LPG) stove and 18-month supply of LPG—has significant value in these communities, irrespective of potential health benefits. For control households, it was necessary to develop a compensation strategy that would be comparable across four settings and would address concerns about differential loss to follow-up, fairness and potential effects on household economics. Each site developed slightly different, contextually appropriate compensation packages by combining a set of uniform principles with local community input. In Guatemala, control compensation consists of coupons equivalent to the LPG stove’s value that can be redeemed for the participant’s choice of household items, which could include an LPG stove. In Peru, control households receive several small items during the trial, plus the intervention stove and 1 month of fuel at the trial’s conclusion. Rwandan participants are given small items during the trial and a choice of a solar kit, LPG stove and four fuel refills, or cash equivalent at the end. India is the only setting in which control participants receive the intervention (LPG stove and 18 months of fuel) at the trial’s end while also being compensated for their time during the trial, in accordance with local ethics committee requirements. The approaches presented here could inform compensation strategy development in future multi-country trials