An Analytical Mechanics Model for the Rotary Sliding Triboelectric Nanogenerator.

In recent years, global attention towards new energy has surged due to increasing energy demand and environmental concerns. Researchers have intensified their focus on new energy, leading to advancements in technologies like triboelectrification, which harnesses energy from the environment. The invention of the triboelectric nanogenerator (TENG) has led to new possibilities, with the rotary sliding TENG standing out for its superior performance. However, understanding its mechanical behavior remains a challenge, potentially leading to structural issues. This paper introduces a novel analytical mechanics model to analyze the mechanical performance of the stator of the rotary sliding TENG, offering a new analytical solution. The solution also presents an innovative approach to solving axisymmetric problems in elasticity theory since it challenges a traditional assumption that the stress function depends solely on the radial coordinate, proposing a new stress function to derive a more general solution, supplementing the classical approach in the theory of elasticity. Through the obtained solutions, the mechanical characteristics of the rotary sliding TENG during operation are analyzed. A clearer relationship between mechanical characteristics and electrical output is expected to provide a theoretical basis for the design of the rotary sliding TENG.

Bioresorbable Multilayer Organic-Inorganic Films for Bioelectronic Systems.

Bioresorbable electronic devices as temporary biomedical implants represent an emerging class of technology relevant to a range of patient conditions currently addressed with technologies that require surgical explantation after a desired period of use. Obtaining reliable performance and favorable degradation behavior demands materials that can serve as biofluid barriers in encapsulating structures that avoid premature degradation of active electronic components. Here, this work presents a materials design that addresses this need, with properties in water impermeability, mechanical flexibility, and processability that are superior to alternatives. The approach uses multilayer assemblies of alternating films of polyanhydride and silicon oxynitride formed by spin-coating and plasma-enhanced chemical vapor deposition , respectively. Experimental and theoretical studies investigate the effects of material composition and multilayer structure on water barrier performance, water distribution, and degradation behavior. Demonstrations with inductor-capacitor circuits, wireless power transfer systems, and wireless optoelectronic devices illustrate the performance of this materials system as a bioresorbable encapsulating structure.

Ultrathin, Transferred Layers of Silicon Oxynitrides as Tunable Biofluid Barriers for Bioresorbable Electronic Systems.

Bio/ecoresorbable electronic systems create unique opportunities in implantable medical devices that serve a need over a finite time period and then disappear naturally to eliminate the need for extraction surgeries. A critical challenge in the development of this type of technology is in materials that can serve as thin, stable barriers to surrounding ground water or biofluids, yet ultimately dissolve completely to benign end products. This paper describes a class of inorganic material (silicon oxynitride, SiON) that can be formed in thin films by plasma-enhanced chemical vapor deposition for this purpose. In vitro studies suggest that SiON and its dissolution products are biocompatible, indicating the potential for its use in implantable devices. A facile process to fabricate flexible, wafer-scale multilayer films bypasses limitations associated with the mechanical fragility of inorganic thin films. Systematic computational, analytical, and experimental studies highlight the essential materials aspects. Demonstrations in wireless light-emitting diodes both in vitro and in vivo illustrate the practical use of these materials strategies. The ability to select degradation rates and water permeability through fine tuning of chemical compositions and thicknesses provides the opportunity to obtain a range of functional lifetimes to meet different application requirements.

α-Ketoglutarate improves cardiac insufficiency through NAD+-SIRT1 signaling-mediated mitophagy and ferroptosis in pressure overload-induced mice.

BACKGROUND: In heart failure (HF), mitochondrial dysfunction and metabolic remodeling lead to a reduction in energy productivity and aggravate cardiomyocyte injury. Supplementation with α-ketoglutarate (AKG) alleviated myocardial hypertrophy and fibrosis in mice with HF and improved cardiac insufficiency. However, the myocardial protective mechanism of AKG remains unclear. We verified the hypothesis that AKG improves mitochondrial function by upregulating NAD+ levels and activating silent information regulator 2 homolog 1 (SIRT1) in cardiomyocytes. METHODS: In vivo, 2% AKG was added to the drinking water of mice undergoing transverse aortic constriction (TAC) surgery. Echocardiography and biopsy were performed to evaluate cardiac function and pathological changes. Myocardial metabolomics was analyzed by liquid chromatography‒mass spectrometry (LC‒MS/MS) at 8 weeks after surgery. In vitro, the expression of SIRT1 or PINK1 proteins was inhibited by selective inhibitors and siRNA in cardiomyocytes stimulated with angiotensin II (AngII) and AKG. NAD+ levels were detected using an NAD test kit. Mitophagy and ferroptosis levels were evaluated by Western blotting, qPCR, JC-1 staining and lipid peroxidation analysis. RESULTS: AKG supplementation after TAC surgery could alleviate myocardial hypertrophy and fibrosis and improve cardiac function in mice. Metabolites of the malate-aspartate shuttle (MAS) were increased, but the TCA cycle and fatty acid metabolism pathway could be inhibited in the myocardium of TAC mice after AKG supplementation. Decreased NAD+ levels and SIRT1 protein expression were observed in heart of mice and AngII-treated cardiomyocytes. After AKG treatment, these changes were reversed, and increased mitophagy, inhibited ferroptosis, and alleviated damage in cardiomyocytes were observed. When the expression of SIRT1 was inhibited by a selective inhibitor and siRNA, the protective effect of AKG was suppressed. CONCLUSION: Supplementation with AKG can improve myocardial hypertrophy, fibrosis and chronic cardiac insufficiency caused by pressure overload. By increasing the level of NAD+, the SIRT-PINK1 and SIRT1-GPX4 signaling pathways are activated to promote mitophagy and inhibit ferroptosis in cardiomyocytes, which ultimately alleviates cardiomyocyte damage.

Facile H2O-Contributed O2 Activation Strategy over Mn-Based SCR Catalysts to Counteract SO2 Poisoning.

Mn-based catalysts preferred in low-temperature selective catalytic reduction (SCR) are susceptible to SO2 poisoning. The stubborn sulfates make insufficient O2 activation and result in deficient reactive oxygen species (ROS) for activating reaction molecules. H2O has long been regarded as an accomplice to SO2, hastening catalyst deactivation. However, such a negative impression of the SCR reaction was reversed by our recent research. Here, we reported a H2O contribution over Mn-based SCR catalysts to counteract SO2 poisoning through accessible O2 activation, in which O2 was synergistically activated with H2O to generate ROS for less deactivation and more expected regeneration. The resulting ROS benefited from the energetically favorable route supported by water-induced Ea reduction and was actively involved in the NH3 activation and NO oxidation process. Besides, ROS maintained high stability over the SO2 + H2O-deactivated γ-MnO2 catalyst throughout the mild thermal treatment, achieving complete regeneration of its own NO disposal ability. This strategy was proven to be universally applicable to other Mn-based catalysts.

Hesperetin, a Promising Dietary Supplement for Preventing the Development of Calcific Aortic Valve Disease.

BACKGROUND: No effective therapeutic agents for calcific aortic valve disease (CAVD) are available currently. Dietary supplementation has been proposed as a novel treatment modality for various diseases. As a flavanone, hesperetin is widely abundant in citrus fruits and has been proven to exert protective effects in multiple diseases. However, the role of hesperetin in CAVD remains unclear. METHODS: Human aortic valve interstitial cells (VICs) were isolated from aortic valve leaflets. A mouse model of aortic valve stenosis was constructed by direct wire injury (DWI). Immunoblotting, immunofluorescence staining, and flow cytometry were used to investigate the roles of sirtuin 7 (Sirt7) and nuclear factor erythroid 2-related factor 2 (Nrf2) in hesperetin-mediated protective effects in VICs. RESULTS: Hesperetin supplementation protected the mice from wire-injury-induced aortic valve stenosis; in vitro, hesperetin inhibited the lipopolysaccharide (LPS)-induced activation of NF-κB inflammatory cytokine secretion and osteogenic factors expression, reduced ROS production and apoptosis, and abrogated LPS-mediated injury to the mitochondrial membrane potential and the decline in the antioxidant levels in VICs. These benefits of hesperetin may have been obtained by activating Nrf2-ARE signaling, which corrected the dysfunctional mitochondria. Furthermore, we found that hesperetin could directly bind to Sirt7 and that the silencing of Sirt7 decreased the effects of hesperetin in VICs and potently abolished the ability of hesperetin to increase Nrf2 transcriptional activation. CONCLUSIONS: Our work demonstrates that hesperetin plays protective roles in the aortic valve through the Sirt7-Nrf2-ARE axis; thus, hesperetin might be a potential dietary supplement that could prevent the development of CAVD.

Alpha-ketoglutarate ameliorates pressure overload-induced chronic cardiac dysfunction in mice.

Increasing evidence indicates the involvement of myocardial oxidative injury and mitochondrial dysfunction in the pathophysiology of heart failure (HF). Alpha-ketoglutarate (AKG) is an intermediate metabolite of the tricarboxylic acid (TCA) cycle that participates in different cellular metabolic and regulatory pathways. The circulating concentration of AKG was found to decrease with ageing and is elevated after acute exercise and resistance exercise and in HF. Recent studies in experimental models have shown that dietary AKG reduces reactive oxygen species (ROS) production and systemic inflammatory cytokine levels, regulates metabolism, extends lifespan and delays the occurrence of age-related decline. However, the effects of AKG on HF remain unclear. In the present study, we explored the effects of AKG on left ventricular (LV) systolic function, the myocardial ROS content and mitophagy in mice with transverse aortic constriction (TAC). AKG supplementation inhibited pressure overload-induced myocardial hypertrophy and fibrosis and improved cardiac systolic dysfunction; in vitro, AKG decreased the Ang II-induced upregulation of ß-MHC and ANP, reduced ROS production and cardiomyocyte apoptosis, and repaired Ang II-mediated injury to the mitochondrial membrane potential (MMP). These benefits of AKG in the TAC mice may have been obtained by enhanced mitophagy, which cleared damaged mitochondria. In summary, our study suggests that AKG improves myocardial hypertrophy remodelling, fibrosis and LV systolic dysfunction in the pressure-overloaded heart by promoting mitophagy to clear damaged mitochondria and reduce ROS production; thus, AKG may have therapeutic potential for HF.

New analytic bending, buckling, and free vibration solutions of rectangular nanoplates by the symplectic superposition method.

New analytic bending, buckling, and free vibration solutions of rectangular nanoplates with combinations of clamped and simply supported edges are obtained by an up-to-date symplectic superposition method. The problems are reformulated in the Hamiltonian system and symplectic space, where the mathematical solution framework involves the construction of symplectic eigenvalue problems and symplectic eigen expansion. The analytic symplectic solutions are derived for several elaborated fundamental subproblems, the superposition of which yields the final analytic solutions. Besides Lévy-type solutions, non-Lévy-type solutions are also obtained, which cannot be achieved by conventional analytic methods. Comprehensive numerical results can provide benchmarks for other solution methods.

Iron deficiency is an independent risk factor of increased myocardial energy expenditure in chronic heart failure patients.

BACKGROUND: Chronic heart failure (CHF) is a major public health burden and is associated with high morbidity, mortality, and cost. Recent studies demonstrated iron metabolism and myocardial energy metabolism were altered in CHF patients. In this study, we aimed to analyze the effects and correlations of iron metabolism on myocardial energy metabolism in CHF. METHODS: One hundred and thirty patients with CHF [age: 66.2±11.5 years, males: 58.5% and New York Heart Association (NYHA) class (II/III/IV): 67/43/20] were included. Serum concentrations of ferritin, transferrin saturation (Tsat), and soluble transferrin receptor (sTfR) were quantified as the indexes of iron metabolism, and echocardiography was used to assess myocardial energy expenditure (MEE) levels. Iron deficiency (ID) was defined as ferritin <100 or 100-300 µg/L with Tsat <20%. RESULTS: Patients with CHF were divided into two groups based on iron status. The prevalence of ID in CHF was 36.9%, and increased with the severity of CHF, reaching 80.0% in those with NYHA class IV (NYHA class II/III/IV: 17.9% vs. 46.5% vs. 80.0%, P=0.000). The demographic characteristics [age, sex, body mass index (BMI), blood pressure, and heart rate] and hemoglobin (HGB) concentrations in two groups were similar (all P>0.05). MEE was significantly higher in the ID group (92.7±23.0 vs. 65.6±20.8 cal/min, P=0.000), while NYHA classes II and III was significantly higher in the ID group (71.6±16.4 vs. 60.3±14.8 cal/min, P=0.022; 88.9±10.4 vs. 69.1±20.1 cal/min, P=0.000). In univariable linear regression models, the presence of ID, higher NYHA class, increased N-terminal pro-B-type natriuretic peptide (NT-proBNP), sTfR, left ventricular internal diastolic diameter (LVIDd), as well as reduced ferritin, Tsat levels, and lower left ventricular ejection fraction (LVEF) were associated with elevated MEE levels (all P<0.05). In multivariable regression models, the presence of ID, reduced Tsat. and increased sTfR remained independent predictors of elevated MEE levels after adjustment for all variables that showed a significant association with MEE (all P<0.05). CONCLUSIONS: The prevalence of ID is high in CHF and is associated with the severity of cardiac dysfunction. The presence of ID as well as reduced Tsat and increased sTfR concentrations are associated with elevated MEE levels in CHF.

Apigenin attenuates myocardial infarction-induced cardiomyocyte injury by modulating Parkin-mediated mitochondrial autophagy.

We aimedto detect whether the effect of apigenin (Apig) on themyocardial infarction-induced cardiomyocyte injury of mouse myocardial cells and acute myocardial infarction (AMI) mice was through regulating Parkin expression via miR-103-1-5p. The myocardial infarction cardiomyocyte model (Hypoxia/reoxygenation) was first constructed, then the mouse myocardial cells were treated with Apig, and the expression of miR-103-1-5p was decreased and the expression of Parkin was increased by qRT-PCR and Western blot. It was confirmed by miRNA pulldown and luciferase reporter system that miR-103-1-5p in mouse myocardial cells can bind to Parkin mRNA and inhibit Parkin expression.Next, a lentiviral vector silenced Parkin and overexpressingmiR-103-1-5pwas constructed and transfected into Apig-treated cells. Autophagy was detected by mitochondrial autophagy marker proteins [atypical protein kinase C (aPKC)-interacting protein (p62) and bcl-2/Adenovirus E1B 19-kd interacting protein 3 (BNIP3)] viaWestern blot, mitochondrial function was detected by JC-1 probe, and apoptosis was detected by flow cytometry. It was confirmed that Apig regulated mitochondria autophagy through miR-103-1-5p and Parkin, which ultimately affected cardiomyocyte death. Finally, an AMI mouse model was constructed, and then the mice were treated with Apig. The infarct size was detected by triphenyl tetrazolium chloride (TTC) staining, and the Apig relieved the myocardial infarction. The expression of miR-103-1-5p was decreased and the expression of Parkin was increased by qRT-PCR andWestern blot. The above results simplified that the cardio protection of Apig and miR-103-1-5p against injury of myocardial infarction cardiomyocyte by targeting Parkin. These results provided a novel treatment againstmyocardial infarction cardiomyocyte.

Ferulic acid increases intestinal Lactobacillus and improves cardiac function in TAC mice.

Ferulic acid, a main ingredient of Ligusticum, exhibits anti-oxidant and anti-inflammation effects in heart diseases. Some studies indicate that gut microbiome is associated with the generation of ferulic acid. Whether the beneficial effect of ferulic is raised by the alteration of gut microbiota is still unknown. This study examined the effect of sodium ferulate on gut microbiome and cardiac function in TAC mice. Cell Counting Kit-8 (CCK8) assay verified that ferulic acid has low toxicity in vitro and that ferulic acid inhibited the up-regulation of ß-MHC and ANP induced by Angiotensin II. In addition, daily supplement of 50 mg/kg sodium ferulate improved the ejection fraction and changed the gut microbiota composition of TAC mice. Relative abundance of Lactobacillus and Parabacteroides are increased in TAC mice gavaged with sodium ferulate. In addition, Lactobacillus is negatively correlated with HW/BW and LW/BW ratio. These results suggest that the beneficial effect of ferulic in TAC mice is probably through the regulation of gut microbiota.

Mitofusin 2 Participates in Mitophagy and Mitochondrial Fusion Against Angiotensin II-Induced Cardiomyocyte Injury.

BACKGROUND: Mitochondrial dynamics play a critical role in mitochondrial function. The mitofusin 2 (MFN2) gene encodes a mitochondrial membrane protein that participates in mitochondrial fusion to maintain and operate the mitochondrial network. Moreover, MFN2 is essential for mitophagy. In Ang II-induced cardiac remodeling, the combined effects of MFN2-mediated mitochondrial fusion and mitophagy are unclear. This study was designed to explore a novel strategy for preventing cardiomyocyte injury via modulation of mitochondrial dynamics. METHODS: We studied the function of MFN2 in mitochondrial fusion and mitophagy in Ang II-stimulated cardiomyocyte injury. Cardiomyocyte injury experiments, including reactive oxygen species (ROS) production, mitochondrial membrane potential (MMP), and apoptosis rate of cardiomyocytes were performed. The mitochondrial morphology in cardiomyocytes was examined via transmission electron microscopy (TEM) and confocal microscopy. Autophagic levels in response to Ang II were examined by immunoblotting of autophagy-related proteins. Moreover, PINK1/MFN2/Parkin pathway-related proteins were examined. RESULTS: With stimulation by Ang II, MFN2 expression was progressively reduced. MFN2 deficiency impaired mitochondrial quality, resulting in exacerbated mitochondrial damage induced by Ang II. The Ang II-induced increases in ROS production and apoptosis rate were alleviated by MFN2 overexpression. Moreover, MFN2 alleviated the Ang II-induced reduction in MMP. MFN2 promoted mitochondrial fusion, and MFN2 promoted Parkin translocation and phosphorylation, leading to mitochondrial autophagy. The effects of MFN2 overexpression were reversed by autophagy inhibitors. CONCLUSION: Mitofusin 2 promotes Parkin translocation and phosphorylation, leading to mitophagy to clear damaged mitochondria. However, the beneficial effects of MFN2 were reversed by autophagy inhibitors. Additionally, MFN2 participates in mitochondrial fusion to maintain mitochondrial quality. Thus, MFN2 participated in mitophagy and mitochondrial fusion against Ang II-induced cardiomyocyte injury.

Metformin Increases Cardiac Rupture After Myocardial Infarction via the AMPK-MTOR/PGC-1α Signaling Pathway in Rats with Acute Myocardial Infarction.

BACKGROUND Cardiac rupture often occurs after acute myocardial infarction due to complex and unclear pathogenesis. This study investigated whether metformin increases the incidence of cardiac rupture after myocardial infarction through the AMPK-MTOR/PGC-1α signaling pathway. MATERIAL AND METHODS An acute myocardial infarction (MI) mouse model was established. A series of experiments involving RT-qPCR, Western blot, TUNEL staining, and Masson staining were performed in this study. RESULTS Myocardial infarction occurred, resulting in the cardiac rupture, and the expression level of PGC-1α increased in the cardiac myocardium. Meanwhile, the proportion of myocardial NT-PGC-1α/PGC-1α decreased. The expression level of myocardial PGC-1α in MI mice with cardiac rupture after MI was significantly higher than that in the mice without cardiac rupture, and the ratio of myocardial NT-PGC-1α/PGC-1α was low. In addition, increasing the dose of metformin significantly increased the incidence of cardiac rupture after myocardial infarction in MI mice. High-dose metformin caused cardiac rupture in MI mice. Moreover, high-dose metformin (Met 2.0 nM) reduces the proportion of NT-PGC-1α/PGC-1α in primary cardiomyocytes of SD mice (SD-NRVCs [Neonatal rat ventricular cardiomyocytes]), and its effect was inhibited by Compound C (AMPK inhibitor). Further, after 3 days of treatment with high-dose metformin in MI mice, myocardial fibrin synthesis decreased and fibrosis was significantly inhibited. Meanwhile, cardiomyocyte apoptosis increased significantly. With the increase in metformin concentration, the expression level of myocardial LC3b gradually increased in MI mice, suggesting that metformin enhances the autophagy of cardiomyocytes. CONCLUSIONS These results suggest that metformin increases cardiac rupture after myocardial infarction through the AMPK-MTOR/PGC-1α signaling pathway.

White-coat hypertension is a risk factor for cardiovascular diseases and total mortality.

BACKGROUND: Whether white-coat hypertension (WCH) is an innocent phenomenon is controversial. METHOD: In this study, we evaluated the association of WCH and the risk of cardiovascular diseases (CVDs) and mortality, stratified by baseline antihypertensive treatment status. Databases (PubMed, EMBASE, CINAHL Plus, Scopus, and Google Scholar) were searched for prospective studies with data on CVD and total mortality associated with WCH. The primary outcomes were the risk of CVD and total mortality associated with WCH stratified by antihypertensive treatment status. The relative risks of events compared with normotension were calculated. RESULTS: A total of 23 cohorts (20 445 individuals), 11 cohorts (8656 individuals), and 12 cohorts (21 336 individuals) were included for analysis of cardiovascular risk associated with WCH in patients without baseline antihypertensive treatment (untreated), or under antihypertensive treatment (treated) or mixed population (including both untreated and treated patients), respectively. In untreated cohorts, WCH was associated with a 38 and 20% increased risk of CVD and total mortality compared with normotension, respectively. In the mixed population, WCH was associated with a 19 and 50% increased risk of CVD and total mortality. However, in the treated patients, neither the risk of CVD, nor total mortality was increased in WCH. Meta-regression analyses indicated that neither differences of clinic blood pressure, nor out-of-office blood pressure variables were correlated with risk of CVD in WCH. CONCLUSION: We concluded that WCH is associated with long-term risk of CVD and total mortality in patients without antihypertensive treatment. Close follow-up should be performed in WCH patients.