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Hydrogen sulfide (H2S) and polysulfides (H2Sn, n ≥ 2) produced by enzymes play a role as signalling molecules regulating neurotransmission, vascular tone, cytoprotection, inflammation, oxygen sensing, and energy formation. H2Sn, which have additional sulfur atoms to H2S, and other S-sulfurated molecules such as cysteine persulfide and S-sulfurated cysteine residues of proteins, are produced by enzymes including 3-mercaptopyruvate sulfurtransferase (3MST). H2Sn are also generated by the chemical interaction of H2S with NO, or to a lesser extent with H2O2. S-sulfuration (S-sulfhydration) has been proposed as a mode of action of H2S and H2Sn to regulate the activity of target molecules. Recently, we found that H2S/H2S2 regulate the release of neurotransmitters, such as GABA, glutamate, and D-serine, a co-agonist of N-methyl-D-aspartate (NMDA) receptors. H2S facilitates the induction of hippocampal long-term potentiation, a synaptic model of memory formation, by enhancing the activity of NMDA receptors, while H2S2 achieves this by activating transient receptor potential ankyrin 1 (TRPA1) channels in astrocytes, potentially leading to the activation of nearby neurons. The recent findings show the other aspects of TRPA1 channels—that is, the regulation of the levels of sulfur-containing molecules and their metabolizing enzymes. Disturbance of the signalling by H2S/H2Sn has been demonstrated to be involved in various diseases, including cognitive and psychiatric diseases. The physiological and pathophysiological roles of these molecules will be discussed. [ABSTRACT FROM AUTHOR]

The purposes of this study were to investigate the relationship between sarcopenia and phase angle (PhA), and to examine whether PhA cutoff values can be used to identify sarcopenia in patients with hematologic malignancies. The study population comprised 108 patients with hematologic malignancies who were admitted for chemotherapy, and were undergoing rehabilitation for exercise therapy. The diagnostic criteria for sarcopenia were determined according to the Asian Working Group for Sarcopenia 2019. Muscle strength, endurance, and body composition (including PhA), were assessed. Logistic regression and receiver operating characteristic (ROC) curve analyses were performed to investigate associations between sarcopenia and PhA, and to determine cutoff values. Sarcopenia was found in 17.6% of the participants. PhA was significantly associated with sarcopenia (p < 0.01). The areas under the curve were 0.84 for the males and 0.87 for the females, and the cutoff values were 4.75° for the males (sensitivity 69%, specificity 83%) and 3.95° for the females (sensitivity 78%, specificity 85%). Our results suggest that PhA, which can be measured noninvasively, objectively, and rapidly, can be used as a screening tool for sarcopenia in patients with hematologic malignancies. [ABSTRACT FROM AUTHOR]

Bi2Se3, one of the most extensively studied topological insulators, has received significant attention, and abundant research has been dedicated to exploring its surface electronic properties. However, little attention has been given to its piezoelectric properties. Herein, we investigate the piezoelectric response in a five-layer Bi2Se3 nanosheet using scanning probe microscopy (SPM) techniques. The piezoelectricity of Bi2Se3 is characterized using both conventional piezoresponse force microscopy (PFM) and a sequential excitation scanning probe microscopy (SE-SPM) technique. To confirm the linear piezoelectricity of Bi2Se3 two-dimensional materials, measurements of point-wise linear and quadratic electromechanical responses are carried out. Furthermore, the presence of polarization and relaxation is confirmed through hysteresis loops. As expected, the Bi2Se3 nanosheet exhibits an electromechanical solid response. Due to the inevitable loss of translational symmetry at the crystal edge, the lattice of the odd-layer Bi2Se3 nanosheet is noncentrosymmetric, indicating its potential for linear piezoelectricity. This research holds promise for nanoelectromechanical systems (NEMS) applications and future nanogenerators. [ABSTRACT FROM AUTHOR]