Department of microTechnology for Biology and Health, CEA LETI-Minatec, Grenoble, France.
Published: March 2013
AI Article Synopsis
Article Abstract
On the road towards efficient diagnostics of infectious diseases, sample preparation is considered as the key step and remains a real technical challenge. Finding new methods for extraction of micro-organisms from a complex biological sample remains a major challenge prior to pathogen detection and analysis. This paper reports a new technique for capturing and isolating micro-organisms from a complex sample. To achieve the segregation of pathogens and blood cells, dielectrophoretic forces applied to bioparticles previously subjected to an osmotic shock are successfully implemented within a dedicated microfluidic device. Our device involves an electrode array of interdigitated electrodes, coated with an insulating layer, to minimize electrochemical reactions with the electrolyte and to enable long-time use. The electric field intensity inside the device is optimized, considering the insulating layer, for a given frequency bandwidth, enabling the separation of bioparticles by dielectrophoretic forces. Our predictions are based on analytical models, consistent with numerical simulations (using COMSOL Multiphysics) and correlated to experimental results. The method and device have been shown to extract different types of micro-organisms spiked in a blood cell sample. We strongly believe that this new separation approach may open the way towards a simple device for pathogen extraction from blood and more generally complex samples, with potential advantages of genericness and simplicity.
Study Question: Does one-step warming (OW), a simplified embryo warming protocol, adversely affect survival and developmental potential in vitrified cleavage or blastocyst stage embryos compared to standard multi-step warming (SW)?
Summary Answer: OW showed no detrimental effects on survival and developmental potential compared to SW in cleavage and blastocyst stage embryos.
What Is Known Already: While standard embryo warming protocols involve a multi-step procedure using a stepwise osmotic solution to avoid a rapid influx of water into the embryo, recent studies suggest that eliminating the stepwise warming process does not reduce embryo survival and embryo transfer outcomes. However, previous reports have focused primarily on pregnancy rates, and a more detailed analysis of the effects of rapid osmotic pressure changes on embryos is necessary to standardize the protocol.
A cell's global physical state is characterized by its volume and dry mass. The ratio of cell mass to volume is the cell mass density (CMD), which is also a measure of macromolecular crowding and concentrations of all proteins. Using the Fluorescence eXclusion method (FXm) and Quantitative Phase Microscopy (QPM), we investigate CMD dynamics after exposure to sudden media osmolarity change.
Key Laboratory of Three Gorges Regional Plant Genetics & Germplasm Enhancement (CTGU)/Biotechnology Research Center, Three Gorges University, Yichang, 443000 Hubei China.
Unlabelled: Hexokinases (HXK) not only facilitate carbohydrate metabolism but also play important roles in sugar sensing in higher plants. gene families have been extensively discussed in many plant species; however, comprehensive information regarding in sorghum remains unclear. To address this gap, we identified 7 putative sorghum ( to ), and the features of their conserved domains, gene structure, evolutionary tree, and cis-acting elements were systematically characterized to reveal the evolutionary conservation between different plant species.
Nuclear deformation by osmotic shock or necrosis activates the cytosolic phospholipase A2 (cPla2) nuclear shape sensing pathway, a key regulator of tissue inflammation and repair. Ca²⁺ and inner nuclear membrane (INM) tension (T ) are believed to mediate nucleoplasmic cPla2 activation. The concept implies that T persists long enough to stimulate cPla2-INM adsorption.
In bacteria, mechanosensitive channels mediate extracellular release of osmolytes, including glutamate, functioning as safety valves upon osmotic downshift. In cyanobacteria, the role of mechanosensitive channels has not been completely elucidated. Recently, the glycogen-deficient ΔglgC mutant of Synechococcus elongatus PCC 7942 was found to release glutamate extracellularly, giving rise to a hypothesis that the role of mechanosensitive channels in cyanobacteria is conserved.
