Search results for "Osmotic"
showing 10 items of 156 documents
The mRNA cap-binding protein Cbc1 is required for high and timely expression of genes by promoting the accumulation of gene-specific activators at pr…
2015
The highly conserved Saccharomyces cerevisiae cap-binding protein Cbc1/Sto1 binds mRNA co-transcriptionally and acts as a key coordinator of mRNA fate. Recently, Cbc1 has also been implicated in transcription elongation and pre-initiation complex (PIC) formation. Previously, we described Cbc1 to be required for cell growth under osmotic stress and to mediate osmostress-induced translation reprogramming. Here, we observe delayed global transcription kinetics in cbc1Δ during osmotic stress that correlates with delayed recruitment of TBP and RNA polymerase II to osmo-induced promoters. Interestingly, we detect an interaction between Cbc1 and the MAPK Hog1, which controls most gene expression c…
Genetic Engineering Strategies for Abiotic Stress Tolerance in Plants
2015
Crop plants are affected by a variety of abiotic stresses such as salinity, drought, extreme temperatures, and oxidative stress and cause a significant yield loss (more than 50 %). In the near future, these abiotic stresses might increase because of global climate change. Abiotic stresses lead to dehydration or osmotic stress through reduced availability of water for vital cellular functions and maintenance of turgor pressure and also result in high production of reactive oxygen species (ROS). Plants are evolved with various mechanisms such as changes in cellular and metabolic processes to cope with the stress condition. Recent developments in molecular genetics have contributed greatly to …
Generalized effective stress concept for saturated active clays
2021
Experimental evidence shows that changes in pore-water chemistry can significantly affect the mechanical behavior of saturated active clays. Despite this evidence, how the chemical composition of the pore water can be considered in effective stress definition is questionable. This paper develops the concept of generalized effective stress for active clays. To this end, physicochemical studies on water–clay mineral interactions are used to clearly define the different types of ions and water present in an active clay. In particular, the presence of both movable and non-movable ions within the liquid water is highlighted. Taking this into account, thermodynamic and geochemistry principles ar…
Novel solutions for closed-loop Reverse Electrodialysis: thermodynamic characterisation and perspective analysis
2019
Abstract Closed-loop Reverse Electrodialysis is a novel technology to directly convert low-grade heat into electricity. It consists of a reverse electrodialysis (RED) unit where electricity is produced exploiting the salinity gradient between two salt-water solutions, coupled with a regeneration unit where waste-heat is used to treat the solutions exiting from the RED unit and restore their initial composition. One of the most important advantages of closed-loop systems compared to the open systems is the possibility to select ad-hoc salt solutions to achieve high efficiencies. Therefore, the properties of the salt solutions are essential to assess the performance of the energy generation a…
Energetics of sodium dodecylsulfate-dodecyldimethylamine oxide mixed micelle formation
1994
Enthalpies of dilution and osmotic coefficients of the sodium dodecyl-sulfate (NaDS)-dodecyldimethylamine oxide (DDAO) mixtures in water have been measured at 25 and 37°C, respectively. From the enthalpies of dilution the apparent molar relative enthalpies LΦ were calculated. The change of the LΦ vs. total molality mt profiles with the mole fraction reflects the variation of the ionic character of the mixed micelles. From the osmotic coefficients the nonideal free energy G2ni were calculated. By combining G2ni with the partial molar relative enthalpies, the nonideal entropies TS2ni were determined. At a given mole fraction, G2ni and TS2ni values are decreasing and increasing respectively, t…
Thermodynamic properties of N-octyl- and N-dodecylnicotinamide chlorides in water
1990
Densities, heat capacities and enthalpies of dilution at 25°C and osmotic coefficients at 37°C were measured for N-octyl- and N-dodecylnicotinamide chlorides in water over an extended concentration region. Partial molar volumes, heat capacities, relative enthalpies and nonideal free energies and entropies at 25°C were derived as a function of the surfactant concentration. For both surfactants, plots of volumes, enthalpies and free energies vs. concentration are regular whereas those of heat capacities and entropies present anomalies at about 0.8 and 0.1m for the octyl and dodecyl compounds, respectively. Changes in the slope of a plot of osmotic coefficients times molality vs. molality were…
Early Osmotherapy in Severe Traumatic Brain Injury: An International Multicenter Study
2020
The optimal osmotic agent to treat intracranial hypertension in patients with severe traumatic brain injury (TBI) remains uncertain. We aimed to test whether the choice of mannitol or hypertonic saline (HTS) as early (first 96 h) osmotherapy in these patients might be associated with a difference in mortality. We retrospectively analyzed data from 2015 from 14 tertiary intensive care units (ICUs) in Australia, UK, and Europe treating severe TBI patients with intracranial pressure (ICP) monitoring and compared mortality in those who received mannitol only versus HTS only. We performed multi-variable analysis adjusting for site and illness severity (Injury Severity Score, extended IMPACT scor…
Response of the aging eye to first day of modern material contact lens wear
2018
Objectives: To investigate the ocular surface of an aged population wearing a daily disposable contact lens over their first day of wear. Methods: Forty eyes from forty presbyopic subjects were fitted a daily CL (Delefilcon A). Tear osmolarity, tear meniscus area (TMA) and ocular surface aberrations (total higher order root means square (RMS)) were assessed at baseline (t0), at 20 minutes (t1) and after 8 hours (t2) of wear. Fluorescein corneal and conjunctival staining and tear break up time (TBUT) were performed at t0 and t2. Results: No statistically significant changes were found between t0, t1 and t2 for TMA, and between t0 and t2 for fluorescein corneal and conjunctival staining. TBUT…
Hypertonic Stress and Amino Acid Deprivation Both Increase Expression of mRNA for Amino Acid Transport System A
2004
The activity of amino acid transport system A ([Oxender and Christensen, 1963][1]) is regulated in a variety of different ways, the best studied being the increases of its activity caused by starving cells of amino acids or by exposing them to hypertonicity (for review see [McGivan and Pastor-
Disruption of the Candida albicans ATC1 gene encoding a cell-linked acid trehalase decreases hypha formation and infectivity without affecting resist…
2007
In Candida albicans, the ATC1 gene, encoding a cell wall-associated acid trehalase, has been considered as a potentially interesting target in the search for new antifungal compounds. A phenotypic characterization of the double disruptant atc1Delta/atc1Delta mutant showed that it was unable to grow on exogenous trehalose as sole carbon source. Unlike actively growing cells from the parental strain (CAI4), the atc1Delta null mutant displayed higher resistance to environmental insults, such as heat shock (42 degrees C) or saline exposure (0.5 M NaCl), and to both mild and severe oxidative stress (5 and 50 mM H(2)O(2)), which are relevant during in vivo infections. Parallel measurements of int…