A porous heterostructure catalyst for oxygen evolution: synergy between IrP2nanocrystals and ultrathin P,N-codoped carbon nanosheets.

Designing efficient and robust oxygen evolution reaction (OER) electrocatalysts is of great importance for various electrochemical energy storage and conversion applications. Herein, we developed IrP2nanocrystals uniformly anchored in P,N-codoped carbon nanosheets (IrP2@PNC-NS) as highly active OER electrocatalysts. The ultrathin PNC-NS reconstructs an agaric-like porous structure, which can inhibit the agglomeration of the IrP2nanocrystals effectively. Moreover, thein-situphosphatization leads to the formation of a strong electron interaction between PNC-NS and IrP2nanocrystals, endowing the heterostructure materials with satisfying synergistic effects. Benefiting from the collaborative advantages of ideal configuration structure and favorable synergistic effects, IrP2@PNC-NS exhibits excellent OER performance with a low overpotential of 221 mV at 10 mA cm-2, and a small Tafel slope of 37.5 mV dec-1. DFT calculations reveal that the synergistic effects derived from the IrP2/PNC interfaces, which can effectively tune the activation barriers towards facilitating the oxygen evolution process. This work provides new insight into the design of heterostructure materials for advanced OER electrocatalysts.

The Stabilization Effect of CO2 in Lithium-Oxygen/CO2 Batteries.

The lithium (Li)-air battery has an ultrahigh theoretical specific energy, however, even in pure oxygen (O2 ), the vulnerability of conventional organic electrolytes and carbon cathodes towards reaction intermediates, especially O2 - , and corrosive oxidation and crack/pulverization of Li metal anode lead to poor cycling stability of the Li-air battery. Even worse, the water and/or CO2 in air bring parasitic reactions and safety issues. Therefore, applying such systems in open-air environment is challenging. Herein, contrary to previous assertions, we have found that CO2 can improve the stability of both anode and electrolyte, and a high-performance rechargeable Li-O2 /CO2 battery is developed. The CO2 not only facilitates the in situ formation of a passivated protective Li2 CO3 film on the Li anode, but also restrains side reactions involving electrolyte and cathode by capturing O2 - . Moreover, the Pd/CNT catalyst in the cathode can extend the battery lifespan by effectively tuning the product morphology and catalyzing the decomposition of Li2 CO3 . The Li-O2 /CO2 battery achieves a full discharge capacity of 6628 mAh g-1 and a long life of 715 cycles, which is even better than those of pure Li-O2 batteries.

Circulating circRNA expression profile and its potential role in late recurrence of paroxysmal atrial fibrillation post catheter ablation.

BACKGROUND: Catheter-based pulmonary vein isolation (PVI) is an effective and well-established intervention for symptomatic paroxysmal atrial fibrillation (PAF). Nevertheless, late recurrences of atrial fibrillation (LRAF) occurring during 3 to 12 months are common, and the underlying mechanisms remain elusive. Circular RNAs (circRNAs) in atrial tissue have been linked to the pathophysiological mechanisms and progression of PAF in a few studies. However, their expression patterns in peripheral blood and regulatory function in LRAF are not clear. METHODS: In the present study, the expression profile of circulating circRNAs in three paired nonvalvular PAF patients with or without LRAF was investigated by high-throughput sequencing and validated by quantitative real-time polymerase chain reaction (qRT-PCR). Bioinformatics analyses, including Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis, and circRNA/miRNA regulatory network, were performed to predict the functions and potential regulatory roles of differentially expressed (DE) circRNAs. RESULTS: A total of 12,834 circRNAs, comprising 5,491 down-regulated and 7,343 up-regulated circRNAs, were found to be DE in blood smaples from the two groups in peripheral blood between LRAF and non-recurrence control individuals. The most enriched GO categories in terms of molecular function, biological process, and cellular component features were catalytic activity, cellular metabolic process, and intracellular part, respectively. The KEGG enrichment study revealed that the most important metabolic process controlled by DE circRNAs is endocytosis. In the circRNA/microRNAs interaction network, four up-regulated circRNAs (hsa_circ_0002665, hsa_circ_0001953, hsa_circ_0003831, and hsa_circ_0040533) and one down-regulated circRNA (hsa_circ_0041103) were predicted to play potential regulatory roles in the pathogenesis of LRAF. CONCLUSIONS: This investigation discovered the expression pattern of circulating circRNAs that is indicative of PAF late recurrence, which may serve as risk markers or therapeutic targets for LRAF after PVI.

Hybrid solid electrolyte enabled dendrite-free Li anodes for high-performance quasi-solid-state lithium-oxygen batteries.

The dendrite growth of Li anodes severely degrades the performance of lithium-oxygen (Li-O2) batteries. Recently, hybrid solid electrolyte (HSE) has been regarded as one of the most promising routes to tackle this problem. However, before this is realized, the HSE needs to simultaneously satisfy contradictory requirements of high modulus and even, flexible contact with Li anode, while ensuring uniform Li+ distribution. To tackle this complex dilemma, here, an HSE with rigid Li1.5Al0.5Ge1.5(PO4)3 (LAGP) core@ultrathin flexible poly (vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) shell interface has been developed. The introduced large amount of nanometer-sized LAGP cores can not only act as structural enhancer to achieve high Young's modulus but can also construct Li+ diffusion network to homogenize Li+ distribution. The ultrathin flexible PVDF-HFP shell provides soft and stable contact between the rigid core and Li metal without affecting the Li+ distribution, meanwhile suppressing the reduction of LAGP induced by direct contact with Li metal. Thanks to these advantages, this ingenious HSE with ultra-high Young's modulus of 25 GPa endows dendrite-free Li deposition even at a deposition capacity of 23.6 mAh. Moreover, with the successful inhibition of Li dendrites, the HSE-based quasi-solid-state Li-O2 battery delivers a long cycling stability of 146 cycles, which is more than three times that of gel polymer electrolyte-based Li-O2 battery. This new insight may serve as a starting point for further designing of HSE in Li-O2 batteries, and can also be extended to various battery systems such as sodium-oxygen batteries.

In Situ Designing a Gradient Li+ Capture and Quasi-Spontaneous Diffusion Anode Protection Layer toward Long-Life Li-O2 Batteries.

Lithium metal is the only anode material that can enable the Li-O2 battery to realize its high theoretical energy density (≈3500 Wh kg-1 ). However, the inherent uncontrolled dendrite growth and serious corrosion limitations of lithium metal anodes make it experience fast degradation and impede the practical application of Li-O2 batteries. Herein, a multifunctional complementary LiF/F-doped carbon gradient protection layer on a lithium metal anode by one-step in situ reaction of molten Li with poly(tetrafluoroethylene) (PTFE) is developed. The abundant strong polar C-F bonds in the upper carbon can not only act as Li+ capture site to pre-uniform Li+ flux but also regulate the electron configuration of LiF to make Li+ quasi-spontaneously diffuse from carbon to LiF surface, avoiding the strong Li+ -adhesion-induced Li aggregation. For LiF, it can behave as fast Li+ conductor and homogenize the nucleation sites on lithium, as well as ensure firm connection with lithium. As a result, this well-designed protection layer endows the Li metal anode with dendrite-free plating/stripping and anticorrosion behavior both in ether-based and carbonate ester-based electrolytes. Even applied protected Li anodes in Li-O2 batteries, its superiority can still be maintained, making the cell achieve stable cycling performance (180 cycles).

Prevention of dendrite growth and volume expansion to give high-performance aprotic bimetallic Li-Na alloy-O2 batteries.

Rechargeable aprotic alkali metal (Li or Na)-O2 batteries are the subject of great interest because of their high theoretical specific energy. However, the growth of dendrites and cracks at the Li or Na anode, as well as their corrosive oxidation lead to poor cycling stability and safety issues. Understanding the mechanism and improving Li/Na-ion plating and stripping electrochemistry are therefore essential to realizing their technological potential. Here, we report how the use of a Li-Na alloy anode and an electrolyte additive realizes an aprotic bimetal Li-Na alloy-O2 battery with improved cycling stability. Electrochemical investigations show that stripping and plating of Li and Na and the robust and flexible passivation film formed in situ (by 1,3-dioxolane additive reacting with the Li-Na alloy) suppress dendrite and buffer alloy anode volume expansion and thus prevent cracking, avoiding electrolyte consumption and ensuring high electron transport efficiency and continued electrochemical reactions.

A high temporal-spatial vehicle emission inventory based on detailed hourly traffic data in a medium-sized city of China.

To improve the accuracy and temporal-spatial resolution for a vehicle emission inventory in a medium-sized city with a strip road network, this study was conducted based on detailed hourly traffic-flow data for each day of 2014, and covered all road types and regions in the city of Foshan. Detailed hourly emission characteristics and sources in five regions were analysed. The results showed that the total vehicle emissions of CO, NOX, VOCs, and PM2.5 were 13.10 × 104, 0.23 × 104, 4.46 × 104, and 0.18 × 104 tons, respectively. Motorcycles (MCs) and light passenger cars (LPCs) were the dominant contributors of CO emissions, while buses and heavy passenger cars (HPCs) were the dominant contributors for NOX. As a whole, the daytime contributions to total emissions were close to 80%, and emissions during the peak periods accounted for almost 40%. Specifically, the hourly emissions of each pollutant on workdays were higher than on non-workdays (maximum up to 64.2%), and for some roads the early peak periods changed significantly from workdays to non-workdays. At expressways, artery roads, and local roads, the daily emission intensities of CO, NOx, and PM2.5 in Foshan were close to or even higher than that of Beijing. On a regional scale, the temporal variation of vehicle emissions on workdays at artery roads of different regions were similar. In addition, the higher emission intensities of CO and VOCs were identified in DaLiang-RongGui (DLRG) and that of NOX and PM2.5 were in Central Region (CR). These results are meaningful for decision-makers to help provide more detailed vehicle pollution control measures in Foshan with a strip road network and only one ring road.

Effect of immune modulation therapy on cardiac function and T-bet/GATA-3 gene expression in aging male patients with chronic cardiac insufficiency.

AIM: The aim of this study was to explore the role of immune modulation therapy in regulating the imbalance of Th1/Th2, serum IFN-γ, IL-4 and the T-cell-specific transcription factors T-bet/GATA-3 in peripheral blood in aging male patients with chronic cardiac insufficiency (CCI). PATIENTS & METHODS: In total, 156 participants were divided into three groups: the CCI intervention group, which received regular therapy and thymopetidum (20 mg intramuscular injection, once every other day for 3 months; n = 70), the CCI control group, which received regular therapy (n = 56) and 50 healthy individuals older than 57 years of age, who served as normal controls. RESULTS: Before therapy, in comparison with the control group, levels of left ventricular end diastolic diameter, NT-proBNP, C-reactive protein (CRP), Th1, Th1/Th2, IFN-γ, and T-bet mRNA and T-bet/GATA-3 mRNA all increased, and the level of left ventricular ejection fraction (LVEF), 6MWT, Th2, IL-4, and GATA-3 mRNA also decreased in both the CCI intervention and control groups. Linear correlation analysis indicated that LVEF was inversely correlated with serum NT-proBNP, CRP, Th1/Th2, IFN-γ and T-bet mRNA/GATA-3 mRNA, and was positively correlated with plasma IL-4. After 3 months of therapy, levels of left ventricular end diastolic diameter, NT-proBNP, CRP, Th1, Th1/Th2, IFN-γ, T-bet mRNA and T-bet/GATA-3 mRNA decreased in the two CCI subgroups, but levels in the CCI intervention group were lower in comparison to the control group. Levels of LVEF, 6MWT, Th2 and GATA-3 mRNA increased in the two CCI subgroups, while levels in the CCI intervention group were higher in comparison with the control group. Plasma levels of IL-4 showed no change after treatment. CONCLUSION: Immune modulation improved cardiac function of CCI patients and was associated with amelioration of T-helper superficial transcription factor polarization and its related cytokine imbalance. Immune modulation might be a new treatment strategy for aging CCI patients.

[Lymphocyte GRK2 expression of the very elderly with chronic heart failure].

OBJECTIVE: To explore the correlation of lymphocyte G protein-coupled receptor kinases 2 (GRK2) expression of the very elderly with chronic heart failure (HF) and heart ejection fraction (EF). METHODS: 16 elderly patients with chronic heart failure were divided into 2 groups as following: EF < 45% (n=7), EF > or = 45% (n=9); and health elderly as control (n=8). Lymphocytes were obtained from blood, reverse transcription polymerase chain reaction were used to measure GRK2 mRNA levels. RESULTS: Lymphocyte GRK2 mRNA levels of EF < 45% group were higher than that of EF > 45% group, which were greater than that of control. CONCLUSION: Elevation of lymphocyte GRK2 levels in HF is associated with heart EF, lymphocytes may provide a surrogate for monitoring cardiac GRK2 in human HF.

Determination of critical size defect of minipig mandible.

The critical size defect (CSD) of bone can provide a standard for evaluating the usefulness of bone repair materials or methods. The present study aimed to determine the CSDs of the minipig mandible with and without the periosteum. Ten 18 month-old female minipigs were used. First, the premolars and the first molar in the right mandible of each minipig were extracted. Two months later, the animals were randomly divided into two groups, with six animals in group A and four in group B. In group A, bone segments of 4, 5 and 6 cm were removed from the right mandible and the neighbouring periosteum was preserved. In group B, bone segments of 1 and 2 cm were removed from the right mandible and the periosteum was removed. The defects were retained with two reconstructive titanium plates. The mandibles underwent X-ray examinations at 4, 8 and 12 weeks after the operation. The animals were sacrificed at 12 weeks after the operation, and specimens were evaluated by gross and histological examinations. For defects retained by two reconstructive plates, the CSDs in the minipig mandible models with and without periosteum were determined as 6 and 2 cm, respectively.