Dysregulated autophagy is associated with many pathological disorders such as cardiovascular diseases. Emerging evidence has suggested that circular RNAs (circRNAs) have important roles in some ...biological processes. However, it remains unclear whether circRNAs participate in the regulation of autophagy. Here we report that a circRNA, termed autophagy-related circular RNA (ACR), represses autophagy and myocardial infarction by targeting Pink1-mediated phosphorylation of FAM65B. ACR attenuates autophagy and cell death in cardiomyocytes. Moreover, ACR protects the heart from ischemia/reperfusion (I/R) injury and reduces myocardial infarct sizes. We identify Pink1 as an ACR target to mediate the function of ACR in cardiomyocyte autophagy. ACR activates Pink1 expression through directly binding to Dnmt3B and blocking Dnmt3B-mediated DNA methylation of Pink1 promoter. Pink1 suppresses autophagy and Pink1 transgenic mice show reduced myocardial infarction sizes. Further, we find that FAM65B is a downstream target of Pink1 and Pink1 phosphorylates FAM65B at serine 46. Phosphorylated FAM65B inhibits autophagy and cell death in the heart. Our findings reveal a novel role for the circRNA in regulating autophagy and ACR-Pink1-FAM65B axis as a regulator of autophagy in the heart will be potential therapeutic targets in treatment of cardiovascular diseases.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Environment‐friendly lead‐free piezoelectric ceramics have been studied extensively in the past decade with great progress particularly in systems based on a niobate perovskite compound formulated as ...(K, Na)NbO3 (abbreviated as KNN). A comprehensive review on the latest development of KNN‐based piezoelectric ceramics is presented in this article, including the phase structure, property enhancement approaches, and sintering processes as well as the status of some promising applications. The phase structure of KNN was reexamined and associated with the effect of chemical modification on its tetragonal‐to‐orthorhombic transition. Then, a special focus is placed on the temperature dependence of piezoelectric properties of KNN‐based ceramics, followed by reviewing the recent approaches devoted to the temperature‐stability enhancement. The processing fundamentals related to the sintering of KNN‐based ceramics are also presented with an emphasis on compositional and microstructural control. Finally, this review introduces several industrial attempts of traditional piezoceramic products using KNN‐based ceramics and the studies on some promising application in authors' laboratory.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
High piezoelectricity of (K,Na)NbO3 (KNN) lead‐free materials benefits from a polymorphic phase transition (PPT) around room temperature, but its temperature sensitivity has been a bottleneck ...impeding their applications. It is found that good thermal stability can be achieved in CaZrO3‐modified KNN lead‐free piezoceramics, in which the normalized strain d
33* almost keeps constant from room temperature up to 140 °C. In situ synchrotron X‐ray diffraction experiments combined with permitivity measurements disclose the occurrence of a new phase transformation under an electrical field, which extends the transition range between tetragonal and orthorhombic phases. It is revealed that such an electrically enhanced diffused PPT contributed to the boosted thermal stability of KNN‐based lead‐free piezoceramics with high piezoelectricity. The present approach based on phase engineering should also be effective in endowing other lead‐free piezoelectrics with high piezoelectricity and good temperature stability.
A material concept of electrically enhanced diffused polymorphic phase transition (EED‐PPT) is developed to resolve the long‐standing issue of temperature‐sensitivity in lead‐free (K,Na)NbO3 piezoelectrics. Experimental and theoretical studies reveal that EED‐PPT can remarkbaly boost the temperature stability of (K,Na)NbO3, where the normalized strain d33* almost keeps constant from room temperature up to 140 °C.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The electrical properties of ferroelectric materials depend on their crystal orientations. The 〈001〉 and 〈111〉 textured 0.90Pb(Mg1/3Nb2/3)O3–0.10PbTiO3 (PMN‐10PT) ceramics were synthesized using a ...template grain growth method and conventional solid sintering process. The Lotgering factors of the 〈001〉 and 〈111〉 textured PMN‐10PT ceramics with 5% anisotropic BaTiO3 (BT) precursors were 95% and 87%, respectively. The influence of grain orientation direction on dielectric properties was investigated, revealing that the permittivity of textured PMN‐10PT ceramics (εr〈001〉 = 12200, εr〈111〉 = 11800) was lower than that of random ceramics (εr = 18700). Electrocaloric (EC) responses of the random and textured samples were analyzed using an indirect polarization‐deduced method based on Maxwell's equations. When the applied field was 50 kV cm−1, the 〈111〉 textured ceramics exhibited an enhanced adiabatic temperature change of 1.30 K, which was 20% higher than that of the random samples. In addition, the EC performance of the 〈111〉 oriented samples was significantly improved compared to that of the 〈001〉 oriented ones. This work characterizes the grain‐orientation‐dependent EC responses in the PMN‐PT system, which would be a promising approach to EC response improvement in ferroelectric ceramics.
The |ΔT| values of different EC ceramics when E = 50 kV cm−1.
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BFBNIB, DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, UILJ, UKNU, UL, UM, UPUK
Rational design and controlled fabrication of efficient and cost-effective electrodes for the oxygen evolution reaction （OER） are critical for addressing the unpre- cedented energy crisis. ...Nickel-iron layered double hydroxides （NiFe-LDHs） with specific interlayer anions （i.e. phosphate, phosphite, and hypophosphite） were fabricated by a co-predpitation method and investigated as oxygen evolution electrocatalysts. Intercalation of the phosphorus oxoanion enhanced the OER activity in an alkaline solution; the optimal performance （i.e., a low onset potential of 215 mV, a small Tafel slope of 37.7 mV/dec, and stable electrochemical behavior） was achieved with the hypophosphite-intercalated NiFe-LDH catalyst, demonstrating dramatic enhancement over the traditional carbonate-intercalated NiFe-LDH in terms of activity and durability. This enhanced performance is attributed to the interaction between the intercalated phosphorous oxoanions and the edge-sharing MO6 （M = Ni, Fe） layers, which modifies the surface electronic structure of the Ni sites. This concept should be inspiring for the design of more effective LDH-based oxygen evolution electrocatalvsts.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OBVAL, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
The ongoing new coronavirus pneumonia (Corona Virus Disease 2019, COVID-19) outbreak is spreading in China, but it has not yet reached its peak. Five million people emigrated from Wuhan before ...lockdown, potentially representing a source of virus infection. Determining case distribution and its correlation with population emigration from Wuhan in the early stage of the epidemic is of great importance for early warning and for the prevention of future outbreaks.
The official case report on the COVID-19 epidemic was collected as of January 30, 2020. Time and location information on COVID-19 cases was extracted and analyzed using ArcGIS and WinBUGS software. Data on population migration from Wuhan city and Hubei province were extracted from Baidu Qianxi, and their correlation with the number of cases was analyzed.
The COVID-19 confirmed and death cases in Hubei province accounted for 59.91% (5806/9692) and 95.77% (204/213) of the total cases in China, respectively. Hot spot provinces included Sichuan and Yunnan, which are adjacent to Hubei. The time risk of Hubei province on the following day was 1.960 times that on the previous day. The number of cases in some cities was relatively low, but the time risk appeared to be continuously rising. The correlation coefficient between the provincial number of cases and emigration from Wuhan was up to 0.943. The lockdown of 17 cities in Hubei province and the implementation of nationwide control measures efficiently prevented an exponential growth in the number of cases.
The population that emigrated from Wuhan was the main infection source in other cities and provinces. Some cities with a low number of cases showed a rapid increase in case load. Owing to the upcoming Spring Festival return wave, understanding the risk trends in different regions is crucial to ensure preparedness at both the individual and organization levels and to prevent new outbreaks.
Abstract
Aims
Naturally secreted nanovesicles, known as exosomes, play important roles in stem cell-mediated cardioprotection. We have previously demonstrated that atorvastatin (ATV) pretreatment ...improved the cardioprotective effects of mesenchymal stem cells (MSCs) in a rat model of acute myocardial infarction (AMI). The aim of this study was to investigate if exosomes derived from ATV-pretreated MSCs exhibit more potent cardioprotective function in a rat model of AMI and if so to explore the underlying mechanisms.
Methods and results
Exosomes were isolated from control MSCs (MSC-Exo) and ATV-pretreated MSCs (MSCATV-Exo) and were then delivered to endothelial cells and cardiomyocytes in vitro under hypoxia and serum deprivation (H/SD) condition or in vivo in an acutely infarcted Sprague-Dawley rat heart. Regulatory genes and pathways activated by ATV pretreatment were explored using genomics approaches and functional studies. In vitro, MSCATV-Exo accelerated migration, tube-like structure formation, and increased survival of endothelial cells but not cardiomyocytes, whereas the exosomes derived from MSCATV-Exo-treated endothelial cells prevented cardiomyocytes from H/SD-induced apoptosis. In a rat AMI model, MSCATV-Exo resulted in improved recovery in cardiac function, further reduction in infarct size and reduced cardiomyocyte apoptosis compared to MSC-Exo. In addition, MSCATV-Exo promoted angiogenesis and inhibited the elevation of IL-6 and TNF-α in the peri-infarct region. Mechanistically, we identified lncRNA H19 as a mediator of the role of MSCATV-Exo in regulating expression of miR-675 and activation of proangiogenic factor VEGF and intercellular adhesion molecule-1. Consistently, the cardioprotective effects of MSCATV-Exo was abrogated when lncRNA H19 was depleted in the ATV-pretreated MSCs and was mimicked by overexpression of lncRNA H19.
Conclusion
Exosomes obtained from ATV-pretreated MSCs have significantly enhanced therapeutic efficacy for treatment of AMI possibly through promoting endothelial cell function. LncRNA H19 mediates, at least partially, the cardioprotective roles of MSCATV-Exo in promoting angiogenesis.
Graphical Abstract
Graphical Abstract
In early January 2012, the Longjiang River was subjected to a serious cadmium (Cd) pollution accident, which led to negatively environmental and social impacts. A series of measures of emergency ...treatment were subsequently taken to reduce water Cd level. However, little information was available about the change of Cd level in environmental matrices and long-term effect of this pollution accident to aquatic ecosystem. Thus, this study investigated the distribution of Cd in water and sediment of this river for two years since pollution accident, as well as assessed its ecological risk to aquatic ecosystem of Longjiang River. The results showed that it was efficient for taking emergency treatment measures to decrease water Cd concentration to below the threshold value of national drinking water quality standard of China. There was high risk (HQ > 1) to aquatic ecosystem in some of reaches between February and July 2012, but low or no risk (HQ < 1) between December 2012 to December 2013. Cd concentration in sediment in polluted reaches increased after pollution accident and emergency treatments in 2012, but decreased in 2013. During flood period, the sediment containing high concentration of Cd in Longjiang River was migrated to downstream Liujiang River. Cd content in sediment was reduced to background level after two years of the pollution accident occurrence. The study provides basic information about Cd levels in different media after pollution accident, which is helpful in evaluating the effectiveness of emergency treatments and the variation of ecological risk, as well as in conducting water management and conservation.
•Ecological risks (ERs) of cadmium-contaminated water and sediment were assessed.•ER decreased in water, but increased in sediment after emergent treatments.•Recovery for water occurred approximately one month later, but two years for sediment.•ER in sediment after accident decreased during flood period.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Antiferroelectric (AFE) materials owing to their double-loop-shaped electric-field (E) dependent polarization (P) are considered quite promising for energy-storage capacitors. Among the large family ...of AFE materials, the AgNbO3 composition is attractive not only because it is environmentally friendly, but also because it has high recoverable energy storage density (Wrec). However, the reported values of Wrec < 4 J cm−3 in Ag(Nb0.85Ta0.15)O3 multilayer capacitors are lower than that of the corresponding monolithic ceramic. This is attributed to high leakage current density (J) and inferior breakdown strength (BDS) in multilayer structures. Here we demonstrate that MnO2 doping not only effectively reduces the J value and results in slim P–E loops, but also enhances the breakdown strength (BDS). Multilayer capacitors with composition Ag(Nb0.85Ta0.15)O3 + 0.25 wt% MnO2 (ANT + Mn) demonstrated an excellent Wrec = 7.9 J cm−3 and efficiency η = 71%. Extensive investigations were conducted on ANT + Mn multilayer capacitors to demonstrate the role of strain engineering in enhancing the maximum polarization (Pmax) and ΔP values. Results reveal the effect of built-in stress in the active layers of multilayer capacitors on the magnitude of Pmax, remanent polarization (Pr) and Wrec, and provide guidance towards the development of high energy storage density in multilayer capacitors.
•A series of diiron azadithiolate models with bulky a bridgehead were prepared.•All the complexes were well characterized and for some by X-ray crystallography.•Phosphine ligands exhibit diverse ...coordination modes in model complexes.•The electrochemical and electrocatalytic properties of these model complexes were studied.
To further explore the function of azadithiolate (ADT) bridges in diiron complexes and to develop new biomimics for the active site of FeFe-H2ases, here a new model complex Fe2{(μ-SCH2)2NCHPh2}(CO)6 (1), featuring a bulky bridgehead (CHPh2) was prepared by condensation reaction of Fe2(μ-SCH2OH)2(CO)6 and NH2CHPh2. The corresponding monophosphine-substituted diiron azadithiolate complexes, Fe2{(μ-SCH2)2NCHPh2}(CO)5 L (2–7) L = PPh3, PPh2(2-C5H4N), PPh2(C6H11), P(C6H4–4-CH3)3, P(C6H4–4–OCH3)3, P(2-C4H3O)3, were prepared via the one-pot method that involves Fe2(μ-SCH2OH)2(CO)6, phosphine ligand and NH2CHPh2. The diphosphine-substituted complexes, Fe2{(μ-SCH2)2NCHPh2}(CO)5(κ1-dppm) dppm = CH2(PPh2)2 (8), Fe2{(μ-SCH2)2NCHPh2} (CO)4{(κ2-Ph2P)2NCH2C6H5} (9), Fe2{(μ-SCH2)2NCHPh2}(CO)4(μ-dppm) (10) and Fe2{(μ-SCH2)2NCHPh2}(CO)4{(μ-Ph2P)2NCH2Ph} (11) were synthesized using either Me3NO-assisted oxidative decarbonylation reaction or thermal reaction. All the new complexes were fully structurally characterized by elemental analysis, spectroscopies, and particularly for 2–10 by X-ray crystallography. Furthermore, the electrochemical and electrocatalytic properties of these model complexes were investigated by cyclic voltammetry, demonstrating their ability to catalyze the reduction of protons to produce H2 when acetic acid was used as the proton source.
A series of diiron azadithiolate models with a bulky bridgehead (CHPh2) were prepared and structurally characterized. The phosphine ligands in these model complexes show a variety of coordination patterns including monodentate, chelated and bridged. Display omitted
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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