Phoenixin-14 (PNX) is a newly identified peptide co-expressed in the hypothalamus with the anorexic and cardioactive Nesfatin-1. Like Nesfatin-1, PNX is able to cross the blood–brain barrier and this ...suggests a role in peripheral modulation. Preliminary mass spectrography data indicate that, in addition to the hypothalamus, PNX is present in the mammalian heart. This study aimed to quantify PNX expression in the rat heart, and to evaluate whether the peptide influences the myocardial function under basal condition and in the presence of ischemia/reperfusion (I/R). By ELISA the presence of PNX was detected in both hypothalamus and heart. In plasma of normal, but not of obese rats, the peptide concentrations increased after meal. Exposure of the isolated and Langendorff perfused rat heart to exogenous PNX induces a reduction of contractility and relaxation, without effects on coronary pressure and heart rate. As revealed by immunoblotting, these effects were accompanied by an increase of Erk1/2, Akt and eNOS phosphorylation. PNX (EC
50
dose), administered after ischemia, induced post-conditioning-like cardioprotection. This was revealed by a smaller infarct size and a better systolic recovery with respect to those detected on hearts exposed to I/R alone. The peptide also activates the cardioprotective RISK and SAFE cascades and inhibits apoptosis. These effects were also observed in the heart of obese rats. Our data provide a first evidence on the peripheral activity of PNX and on its direct cardiomodulatory and cardioprotective role under both normal conditions and in the presence of metabolic disorders.
The layered Ruddlesden–Popper crystal structure can host a broad range of functionally important behaviors. Here we establish extraordinary configurational disorder in a layered Ruddlesden–Popper ...(RP) structure using entropy stabilization assisted synthesis. A protype A 2CuO4 RP cuprate oxide with five cations on the A-site sublattice is designed and fabricated into epitaxial single crystal films using pulsed laser deposition. When grown on a near lattice matched substrate, the (La0.2Pr0.2Nd0.2Sm0.2Eu0.2)2CuO4 film features a T′-type RP structure with uniform A-site cation mixing and square-planar CuO4 units. These observations are made with a range of combined characterizations using X-ray diffraction, atomic-resolution scanning transmission electron microscopy, energy-dispersive X-ray spectroscopy, and X-ray absorption spectroscopy measurements. It is further found that heteroepitaxial strain plays an important role in crystal phase formation during synthesis. Compressive strain over ∼1.5% results in the formation of a non-RP cubic phase consistent with a CuX 2O4 spinel structure. The ability to manipulate configurational complexity and move between 2D layered RP and 3D cubic crystal structures in cuprate and related materials promises to enable flexible design strategies for a range of functionalities, such as magnetoresistance, unconventional superconductivity, ferroelectricity, catalysis, and ion transport.
Magnetic insulators are important materials for a range of next-generation memory and spintronic applications. Structural constraints in this class of devices generally require a clean ...heterointerface that allows effective magnetic coupling between the insulating layer and the conducting layer. However, there are relatively few examples of magnetic insulators that can be synthesized with surface qualities that would allow these smooth interfaces and precisely tuned interfacial magnetic exchange coupling, which might be applicable at room temperature. In this work, we demonstrate an example of how the configurational complexity in the magnetic insulator layer can be used to realize these properties. The entropy-assisted synthesis is used to create single-crystal (Mg0.2Ni0.2Fe0.2Co0.2Cu0.2)Fe2O4 films on substrates spanning a range of strain states. These films show smooth surfaces, high resistivity, and strong magnetic responses at room temperature. Local and global magnetic measurements further demonstrate how strain can be used to manipulate the magnetic texture and anisotropy. These findings provide insight into how precise magnetic responses can be designed using compositionally complex materials that may find application in next-generation magnetic devices.
Preterm birth is a leading cause of infant morbidity and mortality worldwide. The burden of prematurity underscores the need for effective risk reduction strategies. The purpose of this study is to ...evaluate the efficacy of progesterone therapy, both intramuscular 17-α-hydroxyprogesterone caproate (IM 17-OHPC) and vaginal progesterone, in the prevention of recurrent spontaneous preterm birth (sPTB). The co-primary outcomes included: recurrent spontaneous PTB < 37 and < 34 weeks' gestation.
This retrospective cohort study included 637 pregnant patients that delivered at any of the three hospitals within the Los Angeles County healthcare system between October 2015 and June 2021. We compared frequencies of measured variables between each of the progesterone treated groups to no treatment using Pearson chi-squared tests and independent t-tests for categorical and continuous variables, respectively. We estimated crude and adjusted associations between each specific treatment (versus no treatment) and primary outcomes using logistic regression.
Recurrent sPTB < 37 weeks' gestation occurred in 22.3% (n = 64) of those in the no treatment group, 29.1% (n = 86, p = .077) in the 17-OHPC group, and 14.3% (n = 6, p = 0.325) in the vaginal progesterone group. Recurrent sPTB < 34 weeks' gestation was 6.6% (n = 19) in the no treatment group, 11.8% (n = 35, p = .043) in the 17-OHPC group, and 7.1% (n = 3, p = 1) in the vaginal progesterone group. Among all participants, neither 17-OHPC nor vaginal progesterone was significantly associated with a reduction in recurrent sPTB at any time point. Among those with a short cervix, IM 17-OHPC was positively associated with recurrent sPTB < 37 weeks' gestation (aOR 5.61; 95% CI 1.16, 42.9).
Progesterone therapy of any type did not reduce the risk of recurrent sPTB < 34 or < 37 weeks' gestation compared to no progesterone therapy.
Abstract A two-dimensional (2D) Weyl semimetal, akin to a spinful variant of graphene, represents a topological matter characterized by Weyl fermion-like quasiparticles in low dimensions. The spinful ...linear band structure in two dimensions gives rise to distinctive topological properties, accompanied by the emergence of Fermi string edge states. We report the experimental realization of a 2D Weyl semimetal, bismuthene monolayer grown on SnS(Se) substrates. Using spin and angle-resolved photoemission and scanning tunneling spectroscopies, we directly observe spin-polarized Weyl cones, Weyl nodes, and Fermi strings, providing consistent evidence of their inherent topological characteristics. Our work opens the door for the experimental study of Weyl fermions in low-dimensional materials.
As the energy demand is expected to double over the next 30 years, there has been a major initiative towards advancing the technology of both energy harvesting and storage for renewable energy. In ...this work, we explore a subset class of dielectrics for energy storage since ferroelectrics offer a unique combination of characteristics needed for energy storage devices. We investigate ferroelectric lead-free 0.5Ba(Ti0.8Zr0.2)O3-0.5(Ba0.7Ca0.3)TiO3 epitaxial thin films with different crystallographic orientations grown by pulsed laser deposition. We focus our attention on the influence of the crystallographic orientation on the microstructure, ferroelectric, and dielectric properties. Our results indicate an enhancement of the polarization and strong anisotropy in the dielectric response for the (001)-oriented film. The enhanced ferroelectric, energy storage, and dielectric properties of the (001)-oriented film is explained by the coexistence of orthorhombic-tetragonal phase, where the disordered local structure is in its free energy minimum.
Chromogranin A (CgA), a major component of the chromaffin granules, is co-stored and co-released with catecholamines. It is also expressed in extra-adrenal sites, including the heart. In the rat, CgA ...localizes in atrial myoendocrine cells, associated with Atrial Natriuretic Peptide (ANP), and in the conduction system. In the human heart it is present in the ventricular myocardium, co-localized with B-type NP (BNP). CgA is the precursor of several biologically active peptides generated by proteolytic processing also in the heart. Two of them, vasostatin-1 (VS-1) and catestatin (Cst), inhibit cardiac contraction and relaxation, counter-regulate beta-adrenergic and endothelinergic stimulation, and protect the heart against ischemia/reperfusion damages. Recently, clinical studies have suggested CgA to be involved also in cardiovascular pathologies. High plasma CgA levels were found in hypertension, chronic and acute heart failure, myocardial infarction, decompensated and hypertrophic heart, and acute coronary syndromes. These alterations correlate with those of conventional cardiovascular biomarkers, such as NP and endothelin-1 (ET-1), and have prognostic relevance, being indicative of both severity of the disease and mortality. Accordingly, the current knowledge indicates CgA as a multifaceted peptide in cardiovascular homeostasis. Whether the influence elicited by the protein on both normal and failing heart is beneficial and/or detrimental, as well as its implication in the cardiac neuroendocrine scenario is under intense investigation. This review will focus on: i) the involvement of CgA and its derived peptides in the mechanisms which sustain cardiac function and compensation, ii) CgA clinical relevance, and iii) its putative value as a clinical biomarker.
In magnetic systems, spin and exchange disorder can provide access to quantum criticality, frustration, and spin dynamics, but broad tunability of these responses and a deeper understanding of strong ...limit disorder are lacking. Here, it is demonstrated that high entropy oxides present a previously unexplored route to designing materials in which the presence of strong local compositional disorder may be exploited to generate tunable magnetic behaviors—from macroscopically ordered states to frustration‐driven dynamic spin interactions. Single‐crystal La(Cr0.2Mn0.2Fe0.2Co0.2Ni0.2)O3 films are used as a model system hosting a magnetic sublattice with a high degree of microstate disorder in the form of site‐to‐site spin and exchange type inhomogeneity. A classical Heisenberg model simplified to represent the highest probability microstates well describes how compositionally disordered systems can paradoxically host magnetic uniformity and demonstrates a path toward continuous control over ordering types and critical temperatures. Model‐predicted materials are synthesized and found to possess an incipient quantum critical point when magnetic ordering types are designed to be in direct competition, this leads to highly controllable exchange bias behaviors previously accessible only in intentionally designed bilayer heterojunctions.
High entropy oxides provide a previously unexplored route to designing magnetic behaviors not possible in less complex materials. Theoretical predictive models are developed and used to inform single‐crystal film synthesis to gain continuously tunable access to a full range of magnetic states—from antiferromagnetism to ferromagnetism to frustrated dynamical magnetism.
Catestatin (CST), the Chromogranin A (CgA)-derived cationic and hydrophobic peptide, firstly recognized as an endogenous inhibitor of catecholamine secretion, functions as a physiological brake of ...the adreno-sympathetic-chromaffin system. Its wide spectrum of activities includes relevant multilevel cardiovascular and antihypertensive influences. At central systemic level, CST seems to modulate the autonomic cardiovascular control possibly acting on baroreceptor afferent fibers of the nucleus tractus solitarius. This, as well as clinical and experimental (CgA-KO mice) evidences point to an important role of CST in the determinism and prevention of essential hypertension. At organ level, CST exerts myocardial (negative inotropy and lusitropy) effects and potently vasodilates endothelin-1 (ET-1)-preconstricted coronaries through β2-adrenergic receptor (AR)-Gi/o protein-nitric oxide (NO)-cGMP signalling, while counterbalancing β adrenergic (ISO) stimulation. The contractile myocardial effects have been deeply analysed in fish and amphibian hearts, highlighting finely diversified mechanisms of action. CST also acts as cardioprotective agent in both pre- and post-conditioning through NO-dependent mechanisms implicating the Reperfusion Injury Salvage Kinase (RISK) signalling and the activation of mitoKATP channels. The CST-elicited cardiotropic and coronarotropic influences, along with the recently discovered proangiogenic and regulatory effects in glucose and lipid metabolism, contribute to delineate an integrated and updated picture of the peptide which emerges as a pleiotropic hormone with a wide range of cytokine-like characteristics. The aim of this review is to interlock some older and more recent evidences which may help to better perceive the subtle links and differences among the puzzle pieces that still need to be deciphered.
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