Influence of Ferroelectric Filler Size and Clustering on the Electrical Properties of (Ag-BaTiO)-PVDF Sub-Percolative Hybrid Composites.

The paper presents a study concerning the role of ferroelectric filler size and clustering in the dielectric properties of 20%BaTiO-80%PVDF and of 20% (2%Ag-98%BaTiO)-PVDF hybrid nanocomposites. By finite element calculations, it was shown that using fillers with ε > 10 does not provide a permittivity rise in the composites and the effective dielectric constant tends to saturate to specific values determined by the filler size and agglomeration degree. Irrespective of the ferroelectric filler sizes, the addition of metallic ultrafine nanoparticles (Ag) results in permittivity intensification and the effect is even stronger if the metallic nanoparticles are connected to a higher degree with the ferroelectric particles' surfaces.

Optimization of Processing Steps for Superior Functional Properties of (Ba, Ca)(Zr, Ti)O Ceramics.

Lead-free piezoelectric ceramics with nominal composition at morphotropic phase boundary BaCaTiZrO (BCTZ) prepared by different processing routes and sintered either by conventional solid-state reaction or by spark plasma sintering (SPS) techniques were comparatively investigated to observe the role of structural modifications and of microstructures on the dielectric, ferroelectric, piezoelectric and electrocaloric responses. The ceramics presented relative densities from 75% to 97% and showed variations in their phase composition as a result of variable mixing and different synthesis and sintering parameters providing local compositional heterogeneity. As result, all of the ceramics showed diffuse phase transition and ferroelectric switching responses, with parameters affected mostly by density ( between 3.

Role of Density and Grain Size on the Electrocaloric Effect in BaCaTiO Ceramics.

Pure perovskite Ba0.90Ca0.10TiO3 ceramics, with a relative density of between 79 and 98% and grain sizes larger than 1 µm, were prepared by solid-state reaction.

Passion and risk of addiction in experienced female yoga practitioners.

Yoga is a popular leisure activity and health practice worldwide, especially among women. It could become a long-term lifestyle involving passion, but, like other exercises, it may become addictive. While exercise addiction is widely studied, addiction to yoga remains unexplored.

Scale-Dependent Dielectric Properties in BaZrTiO Ceramics.

In the present work, BaZrTiO ceramics with grain sizes between 0.45 and 135 µm were prepared by solid-state reaction and classical sintering. The effect of grain size on dielectric properties was systematically explored, and it was found that dielectric permittivity reaches a maximum value for grain sizes between 1.

Effect of Porosity on Functional Properties of Lead-Free Piezoelectric BaZrTiO Porous Ceramics.

The present paper reports the dependence of dielectric, ferroelectric and piezoelectric properties on the porosity level in BaZrTiO ceramics with porosity from 5% to 21%. Microporosity with 0-3 connectivity has been produced using PMMA microspheres as a sacrificial template. The functional properties (dielectric, ferroelectric and piezoelectric effect) are mostly affected by the "dilution effect": permittivity decreases by 40% when porosity increases by 21%, and P decreases from 13 to 5 µC/cm while the P is in the range of (2-8) µC/cm.

Local Ca signals couple activation of TRPV1 and ANO1 sensory ion channels.

ANO1 (TMEM16A) is a Ca-activated Cl channel (CaCC) expressed in peripheral somatosensory neurons that are activated by painful (noxious) stimuli. These neurons also express the Ca-permeable channel and noxious heat sensor TRPV1, which can activate ANO1. Here, we revealed an intricate mechanism of TRPV1-ANO1 channel coupling in rat dorsal root ganglion (DRG) neurons.

Mechanically activated ion channel PIEZO1 is required for lymphatic valve formation.

PIEZO1 is a cation channel that is activated by mechanical forces such as fluid shear stress or membrane stretch. loss-of-function mutations in patients are associated with congenital lymphedema with pleural effusion. However, the mechanistic link between PIEZO1 function and the development or function of the lymphatic system is currently unknown.

GPR68 Senses Flow and Is Essential for Vascular Physiology.

Mechanotransduction plays a crucial role in vascular biology. One example of this is the local regulation of vascular resistance via flow-mediated dilation (FMD). Impairment of this process is a hallmark of endothelial dysfunction and a precursor to a wide array of vascular diseases, such as hypertension and atherosclerosis.

Common PIEZO1 Allele in African Populations Causes RBC Dehydration and Attenuates Plasmodium Infection.

Hereditary xerocytosis is thought to be a rare genetic condition characterized by red blood cell (RBC) dehydration with mild hemolysis. RBC dehydration is linked to reduced Plasmodium infection in vitro; however, the role of RBC dehydration in protection against malaria in vivo is unknown. Most cases of hereditary xerocytosis are associated with gain-of-function mutations in PIEZO1, a mechanically activated ion channel.

Piezo2 is the principal mechanotransduction channel for proprioception.

Proprioception, the perception of body and limb position, is mediated by proprioceptors, specialized mechanosensory neurons that convey information about the stretch and tension experienced by muscles, tendons, skin and joints. In mammals, the molecular identity of the stretch-sensitive channel that mediates proprioception is unknown. We found that the mechanically activated nonselective cation channel Piezo2 was expressed in sensory endings of proprioceptors innervating muscle spindles and Golgi tendon organs in mice.

Impaired PIEZO1 function in patients with a novel autosomal recessive congenital lymphatic dysplasia.

Piezo1 ion channels are mediators of mechanotransduction in several cell types including the vascular endothelium, renal tubular cells and erythrocytes. Gain-of-function mutations in PIEZO1 cause an autosomal dominant haemolytic anaemia in humans called dehydrated hereditary stomatocytosis. However, the phenotypic consequence of PIEZO1 loss of function in humans has not previously been documented.

Piezo1 links mechanical forces to red blood cell volume.

Red blood cells (RBCs) experience significant mechanical forces while recirculating, but the consequences of these forces are not fully understood. Recent work has shown that gain-of-function mutations in mechanically activated Piezo1 cation channels are associated with the dehydrating RBC disease xerocytosis, implicating a role of mechanotransduction in RBC volume regulation. However, the mechanisms by which these mutations result in RBC dehydration are unknown.

Environmental, dietary, maternal, and fetal predictors of bulky DNA adducts in cord blood: a European mother-child study (NewGeneris).

Background: Bulky DNA adducts reflect genotoxic exposures, have been associated with lower birth weight, and may predict cancer risk.

Objective: We selected factors known or hypothesized to affect in utero adduct formation and repair and examined their associations with adduct levels in neonates.

Methods: Pregnant women from Greece, Spain, England, Denmark, and Norway were recruited in 2006-2010.

Promiscuous activation of transient receptor potential vanilloid 1 (TRPV1) channels by negatively charged intracellular lipids: the key role of endogenous phosphoinositides in maintaining channel activity.

The regulation of the heat- and capsaicin-activated transient receptor potential vanilloid 1 (TRPV1) channels by phosphoinositides is controversial. Data in cellular systems support the dependence of TRPV1 activity on phosphoinositides. The purified TRPV1, however, was recently shown to be fully functional in artificial liposomes in the absence of phosphoinositides.

Bulky dna adducts in cord blood, maternal fruit-and-vegetable consumption, and birth weight in a European mother-child study (NewGeneris).

Background: Tobacco-smoke, airborne, and dietary exposures to polycyclic aromatic hydrocarbons (PAHs) have been associated with reduced prenatal growth. Evidence from biomarker-based studies of low-exposed populations is limited. Bulky DNA adducts in cord blood reflect the prenatal effective dose to several genotoxic agents including PAHs.

Distinctive changes in plasma membrane phosphoinositides underlie differential regulation of TRPV1 in nociceptive neurons.

Transient Receptor Potential Vanilloid 1 (TRPV1) is a polymodal, Ca(2+)-permeable cation channel crucial to regulation of nociceptor responsiveness. Sensitization of TRPV1 by G-protein coupled receptor (GPCR) agonists to its endogenous activators, such as low pH and noxious heat, is a key factor in hyperalgesia during tissue injury as well as pathological pain syndromes. Conversely, chronic pharmacological activation of TRPV1 by capsaicin leads to calcium influx-induced adaptation of the channel.

Decrease in phosphatidylinositol 4,5-bisphosphate levels mediates desensitization of the cold sensor TRPM8 channels.

The activity of the cold- and menthol-activated transient receptor potential melastatin 8 (TRPM8) channels diminishes over time in the presence of extracellular Ca(2+), a phenomenon referred to as desensitization or adaptation. Here we show that activation of TRPM8 by cold or menthol evokes a decrease in cellular phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P(2)] levels. The decrease in PtdIns(4,5)P(2) levels was accompanied by increased inositol 1,4,5 trisphosphate (InsP(3)) production, and was inhibited by loading the cells with the Ca(2+) chelator BAPTA-AM, showing that it was the consequence of the activation of phospholipase C (PLC) by increased intracellular Ca(2+) concentrations.

[Pure 46,XY gonadal dysgenesis].

The authors report a rare case of pure 46,XY gonadal dysgenesis (Swyer syndrome). Swyer syndrome is associated with 46,XY karyotype, primary amenorrhea as well as the presence of female internal genital tract and bilateral streak gonads in a phenotypic female. The genetic background of this syndrome includes mutations of several genes involved in the testis differentiation cascade.

Phospholipase C mediated modulation of TRPV1 channels.

The transient receptor potential vanilloid type 1 (TRPV1) channels are involved in both thermosensation and nociception. They are activated by heat, protons, and capsaicin and modulated by a plethora of other agents. This review will focus on the consequences of phospholipase C (PLC) activation, with special emphasis on the effects of phosphatidylinositol 4,5-bisphosphate (PIP2) on these channels.

Hydrolysis of phosphatidylinositol 4,5-bisphosphate mediates calcium-induced inactivation of TRPV6 channels.

TRPV6 is a member of the transient receptor potential superfamily of ion channels that facilitates Ca(2+) absorption in the intestines. These channels display high selectivity for Ca(2+), but in the absence of divalent cations they also conduct monovalent ions. TRPV6 channels have been shown to be inactivated by increased cytoplasmic Ca(2+) concentrations.

Dual regulation of TRPV1 by phosphoinositides.

The membrane phospholipid phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2 or PIP2] regulates many ion channels. There are conflicting reports on the effect of PtdIns(4,5)P2 on transient receptor potential vanilloid 1 (TRPV1) channels. We show that in excised patches PtdIns(4,5)P2 and other phosphoinositides activate and the PIP2 scavenger poly-Lys inhibits TRPV1.

Multicentric Castleman disease and systemic lupus erythematosus phenotype in a boy with Klinefelter syndrome: long-term disease stabilization with interferon therapy.

An 11-year-old boy with Klinefelter syndrome had Castleman disease (CD) of plasma cell type develop. Nonregulated antibody production mimicked systemic lupus erythematosus (SLE). Hepatitis C virus (HCV) infection caused significant disease worsening.