Lifelong longitudinal assessment of the contribution of multi-fractal fluctuations to heart rate and heart rate variability in aging mice: role of the sinoatrial node and autonomic nervous system.

Aging is a major risk factor for sinoatrial node (SAN) dysfunction, which can impair heart rate (HR) control and heart rate variability (HRV). HR and HRV are determined by intrinsic SAN function and its regulation by the autonomic nervous system (ANS). The purpose of this study was to use multi-scale multi-fractal detrended fluctuation analysis (MSMFDFA; a complexity-based approach to analyze multi-fractal dynamics) to longitudinally assess changes in multi-fractal HRV properties and SAN function in ECG time series recorded repeatedly across the full adult lifespan in mice.

Solar-driven upgrading of biomass by coupled hydrogenation using in situ (photo)electrochemically generated H.

With the increasing pressure to decarbonize our society, green hydrogen has been identified as a key element in a future fossil fuel-free energy infrastructure. Solar water splitting through photoelectrochemical approaches is an elegant way to produce green hydrogen, but for low-value products like hydrogen, photoelectrochemical production pathways are difficult to be made economically competitive. A possible solution is to co-produce value-added chemicals.

Is it possible to evaluate upper and lower cervical interdependency on supine magnetic resonance imaging?

Background And Purpose:

Photobiomodulation therapy mitigates cardiovascular aging and improves survival.

Background: Photobiomodulation (PBM) therapy, a form of low-dose light therapy, has been noted to be effective in several age-associated chronic diseases such as hypertension and atherosclerosis. Here, we examined the effects of PBM therapy on age-associated cardiovascular changes in a mouse model of accelerated cardiac aging.

Methods: Fourteen months old Adenylyl cyclase type VIII (AC8) overexpressing transgenic mice (n = 8) and their wild-type (WT) littermates (n = 8) were treated with daily exposure to Near-Infrared Light (850 nm) at 25 mW/cm for 2 min each weekday for a total dose of 1 Einstein (4.

Comparative Spectroscopic Study Revealing Why the CO Electroreduction Selectivity Switches from CO to HCOO at Cu-Sn- and Cu-In-Based Catalysts.

To address the challenge of selectivity toward single products in Cu-catalyzed electrochemical CO reduction, one strategy is to incorporate a second metal with the goal of tuning catalytic activity via synergy effects. In particular, catalysts based on Cu modified with post-transition metals (Sn or In) are known to reduce CO selectively to either CO or HCOO depending on their composition. However, it remains unclear exactly which factors induce this switch in reaction pathways and whether these two related bimetal combinations follow similar general structure-activity trends.

A remarkable adaptive paradigm of heart performance and protection emerges in response to marked cardiac-specific overexpression of ADCY8.

Adult (3 month) mice with cardiac-specific overexpression of adenylyl cyclase (AC) type VIII (TG) adapt to an increased cAMP-induced cardiac workload (~30% increases in heart rate, ejection fraction and cardiac output) for up to a year without signs of heart failure or excessive mortality. Here, we show classical cardiac hypertrophy markers were absent in TG, and that total left ventricular (LV) mass was not increased: a reduced LV cavity volume in TG was encased by thicker LV walls harboring an increased number of small cardiac myocytes, and a network of small interstitial proliferative non-cardiac myocytes compared to wild type (WT) littermates; Protein synthesis, proteosome activity, and autophagy were enhanced in TG vs WT, and Nrf-2, Hsp90α, and ACC2 protein levels were increased. Despite increased energy demands in vivo LV ATP and phosphocreatine levels in TG did not differ from WT.

Emergence of heartbeat frailty in advanced age I: perspectives from life-long EKG recordings in adult mice.

The combined influences of sinoatrial nodal (SAN) pacemaker cell automaticity and its response to autonomic input determine the heart's beating interval variability and mean beating rate. To determine the intrinsic SAN and autonomic signatures buried within EKG RR interval time series change in advanced age, we measured RR interval variability before and during double autonomic blockade at 3-month intervals from 6 months of age until the end of life in long-lived (those that achieved the total cohort median life span of 24 months and beyond) C57/BL6 mice. Prior to 21 months of age, time-dependent changes in intrinsic RR interval variability and mean RR interval were relatively minor.

Tin(II) Ureide Complexes: Synthesis, Structural Chemistry, and Evaluation as SnO Precursors.

In an attempt to tailor precursors for application in the deposition of phase pure SnO, we have evaluated a series of tin (-) ureide complexes. The complexes were successfully synthesized by employing ,'-trialkyl-functionalized ureide ligands, in which features such as stability, volatility, and decomposition could be modified with variation of the substituents on the ureide ligand in an attempt to find the complex with the ideal electronic, steric, or coordinative properties, which determine the fate of the final products. The tin(II) ureide complexes - were synthesized by direct reaction [Sn{NMe}] with aryl and alkyl isocyanates in a 1:2 molar ratio.

BaZrS Chalcogenide Perovskite Thin Films by HS Sulfurization of Oxide Precursors.

The earth-abundant ternary compound BaZrS, which crystallizes in the perovskite-type structure, has come into view as a promising candidate for photovoltaic applications. We present the synthesis and characterization of polycrystalline perovskite-type BaZrS thin films. BaZrO precursor layers were deposited by pulsed laser deposition and sulfurized at various temperatures in an argon-diluted HS atmosphere.

Unveiling the Formation of Solid Electrolyte Interphase and its Temperature Dependence in "Water-in-Salt" Supercapacitors.

"Water-in-salt" (WIS) electrolytes have emerged as an excellent superconcentrated ionic medium for high-power energy storage systems such as supercapacitors due to their extended working potential compared to the conventional dilute aqueous electrolyte. In this work, we have investigated the performance of WIS supercapacitors using hollow carbon nanoplates as electrodes and compared it to that based on the conventional "salt-in-water" electrolytes. Moreover, the potentiostatic electrochemical impedance spectroscopy has been employed to provide an insightful look into the charge transport properties, which also, for the first time, reveals the formation of a solid-electrolyte interphase (SEI) and their temperature-dependent impedance for charge transfer and adsorption.

Age-related impairment of cerebral blood flow response to K channel opener in Alzheimer's disease mice with presenilin-1 mutation.

Local cerebral blood flow (CBF) responses to neuronal activity are essential for cognition and impaired CBF responses occur in Alzheimer's disease (AD). In this study, regional CBF (rCBF) responses to the K channel opener diazoxide were investigated in 3xTgAD, WT and mutant Presenilin 1(PS1) mice from three age groups using Laser-Doppler flowmetry. The rCBF response was reduced early in young 3xTgAD mice and almost absent in old 3xTgAD mice, up to 30%-40% reduction with altered CBF velocity and mean arterial pressure versus WT mice.

Different Photostability of BiVO in Near-pH-Neutral Electrolytes.

Photoelectrochemical water splitting is a promising route to produce hydrogen from solar energy. However, corrosion of photoelectrodes remains a fundamental challenge for their implementation. Here, we reveal different dissolution behaviors of BiVO photoanode in pH-buffered borate, phosphate, and citrate (hole-scavenger) electrolytes, studied employing an illuminated scanning flow cell.

Assessment of a W:BiVO-CuBiOTandem Photoelectrochemical Cell for Overall Solar Water Splitting.

We assess a tandem photoelectrochemical cell consisting of a W:BiVO photoanode top absorber and a CuBiO photocathode bottom absorber for overall solar water splitting. We show that the W:BiVO photoanode oxidizes water and produces oxygen at potentials ≥0.7 V vs RHE when CoPi is added as a cocatalyst.

Evaluation of AA-CVD deposited phase pure polymorphs of SnS for thin films solar cells.

Six different thin film solar cells consisting of either orthorhombic (α-SnS) or cubic (π-SnS) tin(ii) sulfide absorber layers have been fabricated, characterized and evaluated. Absorber layers of either π-SnS or α-SnS were selectively deposited by temperature controlled Aerosol Assisted Chemical Vapor Deposition (AA-CVD) from a single source precursor. α-SnS and π-SnS layers were grown on molybdenum (Mo), Fluorine-doped Tin Oxide (FTO), and FTO coated with a thin amorphous-TiO layer (am-TiO -FTO), which were shown to have significant impact on the growth rate and morphology of the as deposited thin films.

Photocurrent Enhancement by Spontaneous Formation of a p-n Junction in Calcium-Doped Bismuth Vanadate Photoelectrodes.

The application of bismuth vanadate (BiVO ) photoelectrodes for solar water splitting is hindered by the poor carrier transport. To overcome this, multiple donor-doping strategies (e.g.

Tin guanidinato complexes: oxidative control of Sn, SnS, SnSe and SnTe thin film deposition.

A family of tin(ii) guanidinate complexes of the general form [{RNC(NMe2)NR}2Sn] (R = iPr (6), Cy (7), Tol (9) and Dipp (10)) and [{tBuNC(NMe2)NtBu}Sn{NMe2}] (8) have been synthesised and isolated from the reaction of tin(ii) bis-dimethylamide and a series of carbodiimides (1-5). The cyclic poly-chalcogenide compounds [{CyNC(NMe2)NCy}2Sn{Chx}] (Ch = S, x = 4 (11); Ch = Se, x = 4 (12), and Ch = S, x = 6 (13)) with {SnChx} rings were prepared by the oxidative addition of elemental sulfur and selenium to the heteroleptic stannylene complex [{CyNC(NMe2)NCy}2Sn] (7) in THF at room temperature. Similarly, reaction of compounds 6 and 7 with an equimolar amount of the chalcogen transfer reagents (SC3H6 and Se[double bond, length as m-dash]PEt3, respectively) led to the formation of the chalcogenide tin(iv) complexes [{RNC(NMe2)NR}Sn(Ch)] (R = Cy: Ch = S (14); R = iPr, Ch = Se (15); R = Cy, Ch = Se (16)) with terminal Sn[double bond, length as m-dash]Ch (14 and 16) and dimeric bridged seleno-tin {Sn2Se2} rings (15), respectively.

Mammalian γ2 AMPK regulates intrinsic heart rate.

AMPK is a conserved serine/threonine kinase whose activity maintains cellular energy homeostasis. Eukaryotic AMPK exists as αβγ complexes, whose regulatory γ subunit confers energy sensor function by binding adenine nucleotides. Humans bearing activating mutations in the γ2 subunit exhibit a phenotype including unexplained slowing of heart rate (bradycardia).

Facile Bulk Synthesis of π-Cubic SnS.

The cubic modification of binary tin sulfide (SnS) has gained significant interest as an earth-abundant, low-toxicity solar absorber material with a band gap close to the optimal value for the conversion of sunlight. We herein report a simple synthesis for the metastable material, which will allow more elaborate characterization methods to be used on this material, and present a full powder refinement of the material along with some preliminary results on the optical and thermal stability properties.

Long-term low dose dietary resveratrol supplement reduces cardiovascular structural and functional deterioration in chronic heart failure in rats.

A short-term exposure to resveratrol at high dosages exerts a remarkable cardioprotective effect. Whether a long-term exposure to resveratrol at low dosages that can be obtained through consumption of a resveratrol-rich diet is beneficial to heart diseases is unknown. We tested the effects of a resveratrol-enriched diet on cardiovascular remodeling of chronic heart failure (CHF) in rats resulting from permanent ligation of left coronary artery.

A Rat Carotid Balloon Injury Model to Test Anti-vascular Remodeling Therapeutics.

The rat carotid balloon injury is a well-established surgical model that has been used to study arterial remodeling and vascular cell proliferation. It is also a valuable model system to test, and to evaluate therapeutics and drugs that negate maladaptive remodeling in the vessel. The injury, or barotrauma, in the vessel lumen caused by an inflated balloon via an inserted catheter induces subsequent neointimal growth, often leading to hyperplasia or thickening of the vessel wall that narrows, or obstructs the lumen.

Deterioration of autonomic neuronal receptor signaling and mechanisms intrinsic to heart pacemaker cells contribute to age-associated alterations in heart rate variability in vivo.

We aimed to determine how age-associated changes in mechanisms extrinsic and intrinsic to pacemaker cells relate to basal beating interval variability (BIV) reduction in vivo. Beating intervals (BIs) were measured in aged (23-25 months) and adult (3-4 months) C57BL/6 male mice (i) via ECG in vivo during light anesthesia in the basal state, or in the presence of 0.5 mg mL(-1) atropine + 1 mg mL(-1) propranolol (in vivo intrinsic conditions), and (ii) via a surface electrogram, in intact isolated pacemaker tissue.

Delayed emergence of methamphetamine's enhanced cardiovascular effects in nonhuman primates during protracted methamphetamine abstinence.

Background: Methamphetamine abuse is linked with brain abnormalities, but its peripheral effects constitute an integral aspect of long-term methamphetamine use.

Methods: Eight male rhesus monkeys with long histories of intravenous methamphetamine self-administration were evaluated 1 day, and 1, 4, 12, 26, and 52 weeks after their last methamphetamine self-administration session. On test days, isoflurane-anesthetized animals received a 0.

Vessel ultrasound sonographic assessment of soluble receptor for advanced glycation end products efficacy in a rat balloon injury model.

Objective: We aimed to assess the therapeutic efficacy of differentially modified soluble receptor for advanced glycation end products (sRAGE) in vivo using vessel ultrasound sonography and to compare the sonography data with those from postmortem histomorphologic analyses to have a practical reference for future clinical applications.

Methods: Vessel ultrasound sonography was performed in a sRAGE-treated rat carotid artery balloon injury model at different time points after the surgery, and therapeutic efficacy of different doses of sRAGE produced in Chinese hamster ovary cells and with different N-glycoform modifications were assessed.

Results: Vessel ultrasound sonography found that sRAGE produced in Chinese hamster ovary cells with complex N-glycoform modifications is highly effective, and is consistent with our recent findings in the same model assessed with histology.

Synchronization of sinoatrial node pacemaker cell clocks and its autonomic modulation impart complexity to heart beating intervals.

Background: A reduction of complexity of heart beating interval variability that is associated with an increased morbidity and mortality in cardiovascular disease states is thought to derive from the balance of sympathetic and parasympathetic neural impulses to the heart. However, rhythmic clocklike behavior intrinsic to pacemaker cells in the sinoatrial node (SAN) drives their beating, even in the absence of autonomic neural input.

Objective: To test how this rhythmic clocklike behavior intrinsic to pacemaker cells interacts with autonomic impulses to the heart beating interval variability in vivo.