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There is a growing interest in conductivity detection for capillary electrophoresis; especially because of capacitively coupled contactless conductivity approach. This robust and general-purpose detector has another lesser-known feature: sensitivity does not depend on the very chemical nature of the analyte, but only on its effective charge and effective mobility. Therefore, the calibration curve prepared for a given species may be used to quantify another one of same charge and mobility. In the absence of a species (calibrant) of exactly the same mobility, two or more calibrants can be used. Provided the sensitivity varies smoothly in the desired region of mobility, it can be mathematically described by a function. For small ranges of mobilities, a linear behavior is expected, and the sensitivity for the analyte can be obtained by interpolation. This technique was investigated for eight different combinations of mono- and double-charged cationic and anionic analytes using buffered and unbuffered background electrolytes (BGEs). For most of the applications, a linear model was enough to describe the sensitivity (0.988 < R 2  < 0.998), but for ample range of mobilities, the inclusion of a hyperbolic term was needed (0.995 < R 2  < 0.999). This technique has a great potential to be used in field applications and in laboratories when the analytes are unstable or they are not available to be used in the preparation of standard solutions., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

The human body experiences physiological changes under microgravity environment that phenocopy aging on Earth. These changes include early onset osteoporosis, skeletal muscle atrophy, cardiac dysfunction, and immunosenescence, and such adaptations to the space environment may pose some risk to crewed missions to Mars. To investigate the effect of microgravity on aging, many model organisms have been used such as the nematode Caenorhabditis elegans, the fruit fly Drosophila melanogaster, and mice. Herein we report that the budding yeast Saccharomyces cerevisiae show decreased replicative lifespan (RLS) under simulated microgravity in a clinostat. The reduction of yeast lifespan is not a result of decreased tolerance to heat shock or oxidative stress and could be overcome either by deletion of FOB1 or calorie restriction, two known interventions that extend yeast RLS. Deletion of the sirtuin gene SIR2 worsens the simulated microgravity effect on RLS, and together with the fob1Δ mutant phenotype, it suggests that simulated microgravity augments the formation of extrachromosomal rDNA circles, which accumulate in yeast during aging. We also show that the chronological lifespan in minimal medium was not changed when cells were grown in the clinostat. Our data suggest that the reduction in longevity due to simulated microgravity is conserved in yeast, worms, and flies, and these findings may have potential implications for future crewed missions in space, as well as the use of microgravity as a model for human aging., (Copyright © 2020 The Committee on Space Research (COSPAR). Published by Elsevier B.V. All rights reserved.)

The importance of microorganisms and biotechnology in space exploration and future planets colonization has been discussed in the literature. Meteorites are interesting samples to study microbe-mineral interaction focused on space exploration. The chemolithotropic bacterium Acidithiobacillus ferrooxidans has been used as model to understand the iron and sulfur oxidation. In this work, capillary electrophoresis with capacitively coupled contactless conductivity detection and UV detection was used to monitor bacterial growth in a meteorite simulant by measuring the conversion of Fe 2+ into Fe +3 . The effect of Co 2+ and Ni 2+ (metals also found in meteorites) on the bacterial growth was also evaluated. The presented method allowed the analyses of all metals in a single run (less than 8 min). The background electrolyte was composted of 10 mmol/L α-hydroxyisobutyric acid/Histidine. For comparison purpose, the samples were also analyzed by UV-Vis spectrophotometry. The Fe 2+ conversion into Fe 3+ by A. ferrooxidans was observed up to 36 h with the growth rate constant of 0.19/h and 0.21/h in Tuovinen and Kelly (T&K) and in meteorite simulant media, respectively. The developed method presents favorable prospect to monitor the growth of other chemolithotropic microorganisms for biotechnology applications., (© 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

In this study, homemade disposable gold electrodes made from recordable compact disks were modified with carbon nanotubes for amperometric quantification of terbutaline sulfate in pharmaceutical products. A flow cell using an impingent jet of solution on the electrode surface was build and used for amperometric detection, and a series of experiments were carried out to find the best experimental conditions for the new electrode in a specially designed cell. A linear response for terbutaline was obtained in the range from 3.0 × 10(-6) to 5.0 × 10(-4) mol L(-1) (at 0.63 V vs. Ag/AgCl). The limits of detection and quantification were calculated as 5.8 × 10(-7) mol L(-1) (S/N = 3) and 1.9 × 10(-6) mol L(-1) (S/N = 10), respectively. A frequency of 30 injections h(-1) was attained. The proposed method was successfully applied to the analyses of commercial syrup samples, and all results were in good agreement with those obtained by using high performance liquid chromatography and capillary electrophoresis-tandem mass spectrometry., (Copyright © 2016 Elsevier B.V. All rights reserved.)

A simple, fast, and inexpensive masking technology without any photolithographic step to produce glass microchannels is proposed in this work. This innovative process is based on the use of toner layers as mask for wet chemical etching. The layouts were projected in graphic software and printed on wax paper using a laser printer. The toner layer was thermally transferred from the paper to cleaned glass surfaces (microscope slides) at 130 degrees C for 2 min. After thermal transference, the glass channel was etched using 25% (v/v) hydrofluoric acid (HF) solution. The toner mask was then removed by cotton soaked in acetonitrile. The etching rate was approximately 7.1 +/- 0.6 microm min(-1). This process is economically more attractive than conventional methods because it does not require any sophisticated instrumentation and it can be implemented in any chemical/biochemical laboratory. The glass channel was thermally bonded against a flat glass cover and its analytical feasibility was investigated using capacitively coupled contactless conductivity detection (C(4)D) and laser-induced fluorescence (LIF) detection.