Methyl formate (MF) is one of the most important chemical commodities, which has a wide range of applications. Due to environmental friendliness, mild reaction conditions, and easy operations, ...electrosynthesis of MF has garnered increasing attention in recent years. In this work, we reported an electrosynthesis route toward MF in a halide‐containing methanol solution. The thorough mechanistic investigations point out that electrosynthesis of MF is accomplished by instant reaction between aldehyde from anodic methanol oxidation, and methoxy bromide (CH3OBr) that is in‐situ generated by reaction of Br2 from anodic oxidation of Br− with methoxide (CH3O−) from cathodic reduction of methanol. This method features high atomic economy only producing valuable MF and hydrogen gas, and shows distinct advantages compared to the reported MF electrosynthesis methods. Even at 200 mA/cm2, the faradaic efficiency (FE) of MF remains consistently around 60 % at the anode while a 100 % FE hydrogen gas is produced at the cathode.
Efficient electrosynthesis of methyl formate is achieved through the facile reaction between formaldehyde produced from anodic methanol oxidation, and methoxy bromide which is in‐situ generated by reaction of Br2 from anodic oxidation of Br− and methoxide from cathodic methanol reduction. This method features high atomic economy only producing valuable methyl formate and hydrogen gas.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Osteoarthritis (OA) is the most common joint disease and is the leading cause of chronic disability among older people. Chondrocyte death and extracellular matrix (ECM) degradation was involved in OA ...pathogenesis. Ferroptosis was an iron-dependent cell death associated with peroxidation of lipids. Here, we proved that ferroptosis exists in OA and identified glutathione peroxidase 4 (GPX4) as an important regulator of OA.
Ferroptosis-related alterations were analyzed in human OA and undamaged cartilage. Expression of GPX4 was examined in 55 paired human OA samples. Ferrostatin-1 (Fer-1) and Deferoxamine (DFO) were used to treat OA, in vitro and in vivo. Alterations of GPX4-mediated signaling pathway were identified by RNA-seq analysis. AAV-Gpx4-shRNA were used to downregulate GPX4 expression in vivo.
Transcriptomic, biochemical, and microscopical analyses indicated that ferroptosis was closely associated with OA. Expression of GPX4 in the OA cartilage from 55 OA patients were significantly lower than undamaged cartilage. Fer-1 and DFO could protect OA in a necroptosis-independent manner, suggesting that ferroptosis exists in OA prog. Importantly, GPX4 downregulation could increase the sensitivity of chondrocytes to oxidative stress and aggravate ECM degradation through the MAPK/NFκB pathway. Furthermore, downregulation of GPX4 expression by AAV-Gpx4 shRNA aggravated OA in vivo.
Ferroptosis contributes to OA pathogenesis and GPX4 was the intersection of two mechanisms in regulating OA progression: ferroptosis and ECM degradation.
This work was supported by the Projects of International Cooperation and Exchanges of National Natural Science Funding of China (Grant no. 81820108020), the National Key Research and Development Project of China (Grant no. 2018YFC1106300) and the Basic Science Program of Shanghai Jiao Tong University Affiliated Sixth People's Hospital (Grant no. ynms202102).
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In recent years, the chaos-based cryptographic algorithms have attracted a lot of attention. Specially, chaotic tent map (CTM)-based schemes show some good performances in randomness properties and ...security level. However, several shortcomings still can be found from them. In this paper, based on the security analysis of the pure CTM-based scheme, we propose a novel image encryption algorithm by using the combination of the rectangular transform and the CTM principle. It encrypts the three channels of the plain image at the same time, and these channel encryptions associate with each other. In addition, by generating the key streams related to both the secret keys and the plain image, its key-sensitivity has been further improved. The security of the proposed scheme has been verified by security analysis and experimental evaluations, and our results show that many drawbacks of pure CTM-based schemes have been overcome.
Abstract
Air quality is concerned with pollutants in both the gas phase and solid or liquid phases. The latter are referred to as aerosols, which are multifaceted agents affecting air quality, ...weather and climate through many mechanisms. Unlike gas pollutants, aerosols interact strongly with meteorological variables with the strongest interactions taking place in the planetary boundary layer (PBL). The PBL hosting the bulk of aerosols in the lower atmosphere is affected by aerosol radiative effects. Both aerosol scattering and absorption reduce the amount of solar radiation reaching the ground and thus reduce the sensible heat fluxes that drive the diurnal evolution of the PBL. Moreover, aerosols can increase atmospheric stability by inducing a temperature inversion as a result of both scattering and absorption of solar radiation, which suppresses dispersion of pollutants and leads to further increases in aerosol concentration in the lower PBL. Such positive feedback is especially strong during severe pollution events. Knowledge of the PBL is thus crucial for understanding the interactions between air pollution and meteorology. A key question is how the diurnal evolution of the PBL interacts with aerosols, especially in vertical directions, and affects air quality. We review the major advances in aerosol measurements, PBL processes and their interactions with each other through complex feedback mechanisms, and highlight the priorities for future studies.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
This paper reports our current material research and development for advanced intermediate temperature (IT, 400–700
°C) solid oxide fuel cells (SOFCs). The materials reported in this work are based ...on ceria–salt-composites, which have super function, e.g. displaying ionic conductivity of 0.01–1
S
cm
−1 in the IT region. They are functional ceramic materials for advanced ITSOFC applications. When these new composites are used as ITSOFC electrolytes, a performance of 300–800
mW
cm
−2 between 400 and 650
°C has been demonstrated.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
A
bstract
Detections of non-gravitational interactions of massive dark matter (DM) with visible sector so far have given null results. The DM may communicate with the ordinary matter only through ...gravitational interaction. Besides, the majority of traditional direct detections have poor sensitivities for light DM because of the small recoil energy. Thanks to the high energy cosmic rays (CRs), the light DM can be boosted by scattering with CRs and thus may be detected in the ongoing experiments. In this work, we derive the exclusion limits on the cosmic ray boosted sub-GeV DM with gravitational mediator from the Xenon1T data. It turns out that a sizable region of such a cosmic ray boosted DM can be excluded by the current data.
We revisit the Simple Extension of the Standard Model (SESM), which can account for various tentative new physics anomalies and dark matter. The B physics anomalies, muon anomalous magnetic moment, ...and dark matter can be explained already in SESM. In this work, we study the unitarity constraint on this model and comment the parameter space on the edge of unitarity bounds. Besides, the complete scalar potential is considered which is needed to address the W boson anomaly and more dark matter (co-)annihilation processes are discussed. We perform a systematic study, and find the viable parameter space which can explain these anomalies and evade all the current experimental constraints.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In this paper, we explore the ranking methods with hesitant fuzzy preference relations (HFPRs) in the group decision making environments. As basic elements of hesitant fuzzy sets, hesitant fuzzy ...elements (HFEs) usually have different numbers of possible values. In order to compute or compare HFEs, we have two principles to normalize them, i.e., the α-normalization and the β-normalization. Based on the α-normalization, we develop a new hesitant goal programming model to derive priorities from HFPRs. On the basis of the β-normalization, we develop the consistency measures of HFPRs, establish the consistency thresholds to measure whether or not an HFPR is of acceptable consistency, and then use the hesitant aggregation operators to aggregate preferences in HFPRs to obtain the ranking results.
Exploring the realm of Dark Matter research, Light DM, which has a mass in the range of 1 MeV to 1 GeV, is a fascinating topic both theoretically and experimentally. We assume that the light dark ...matter is composed of complex scalars and produced from semi-annihilation, which is close to the scale of the MeV Gamma-ray satellite, allowing us to explore the implications of this hypothesis. The experimental data we used to constrain the scenario is from five different sources: the COMPTEL, EGRET, INTEGRAL, Fermi Gamma-ray Space Telescope, and the e-ASTROGAM future reach. We use the analytical formula to measure the X-ray spectra allowing us to determine the annihilation cross-section bounds from 10−28cm3/s to 10−22cm3/s for different combinations of dark matter and mediator masses. We found that the MeV gamma-ray provides valuable insight into the structure of the semi-annihilation dark matter, where EGRET contributes to the stringent constraint to the semi-annihilation, and the e-ASTROGAM future reach could probe the whole parameter space of the model.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Catalytic oxidation is a promising manner to produce 2,5-furandicarboxylic acid (FDCA) from 5-Hydroxymethylfurfural (HMF). This review summarizes the progress in the thermocatalysis, ...electrocatalysis, and photocatalysis for FDCA production, including catalyst screening, synthesis processes, and reaction mechanism.
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Biomass conversion to value-added chemicals has received tremendous attention for solving global warming issues and fossil fuel depletion. 5-Hydroxymethylfurfural (HMF) is a key bio-based platform molecule to produce many useful organic chemicals by oxidation, hydrogenation, polymerization, and ring-opening reactions. Among all derivatives, the oxidation product 2,5-furandicarboxylic acid (FDCA) is a promising alternative to petroleum-based terephthalic acid for the synthesis of biodegradable plastics. This review analytically discusses the recent progress in the thermocatalytic, electrocatalytic, and photocatalytic oxidation of HMF into FDCA, including catalyst screening, synthesis processes, and reaction mechanism. Rapid fundamental advances may be possible in non-precious metal and metal-free catalysts that are highly efficient under the base-free conditions, and external field-assisted processes like electrochemical or photoelectrochemical cells.
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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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