Revisiting the driving force inducing phase separation in PEG-phosphate aqueous biphasic systems.

Liquid phase separation using aqueous biphasic systems (ABS) is widely used in industrial processes for the extraction, separation and purification of macromolecules. Using water as the single solvent, a wide variety of solutes have been used to induce phase separation including polymers, ionic liquids or salts. For each system, polymer-polymer, polymer-ionic liquid, polymer-salt or salt-salt, different driving forces were proposed to induce phase separation.

Reduced rapid eye movement sleep in late middle-aged and older apolipoprotein E ɛ4 allele carriers.

Study Objectives: Apolipoprotein E ɛ4 (APOE4) is the strongest genetic risk factor for Alzheimer's disease (AD). In addition, APOE4 carriers may exhibit sleep disturbances, but conflicting results have been reported, such that there is no clear consensus regarding which aspects of sleep are impacted. Our objective was to compare objective sleep architecture between APOE4 carriers and non-carriers, and to investigate the modulating impact of age, sex, cognitive status, and obstructive sleep apnea (OSA).

Longitudinal study of childhood sleep trajectories and adolescent mental health problems.

Study Objective: To investigate whether childhood sleep trajectories are associated with mental health symptoms such as social phobia, generalized anxiety, depression, attention deficit hyperactivity disorder (ADHD), conduct problems, and opposition at age 15.

Methods: A total of 2120 children took part in the Quebec Longitudinal Study of Child Development. Childhood sleep trajectories were computed from maternal reports at 2.

A fatty acid anabolic pathway in specialized-cells sustains a remote signal that controls egg activation in Drosophila.

Egg activation, representing the critical oocyte-to-embryo transition, provokes meiosis completion, modification of the vitelline membrane to prevent polyspermy, and translation of maternally provided mRNAs. This transition is triggered by a calcium signal induced by spermatozoon fertilization in most animal species, but not in insects. In Drosophila melanogaster, mature oocytes remain arrested at metaphase-I of meiosis and the calcium-dependent activation occurs while the oocyte moves through the genital tract.

APP substrate ectodomain defines amyloid-β peptide length by restraining γ-secretase processivity and facilitating product release.

Sequential proteolysis of the amyloid precursor protein (APP) by γ-secretases generates amyloid-β (Aβ) peptides and defines the proportion of short-to-long Aβ peptides, which is tightly connected to Alzheimer's disease (AD) pathogenesis. Here, we study the mechanism that controls substrate processing by γ-secretases and Aβ peptide length. We found that polar interactions established by the APP ectodomain (ECD), involving but not limited to its juxtamembrane region, restrain both the extent and degree of γ-secretases processive cleavage by destabilizing enzyme-substrate interactions.