We first demonstrate the rational design and fabrication of novel atomically thick Co3O4 nanosheets (ATCNs) with a specific facet exposed by topochemical transformation from layered intermediate ...precursors to optimize energy storage. The eminently enhanced lithium storage performance can be attributed not only to the synergistic advantages of inorganic graphene analogues but also the increase of Co(2+) atoms and charge redistribution for ATCNs, which were first revealed by means of synchrotron radiation X-ray absorption near-edge spectroscopy. This work opens the window for the preparation of non-layered atomically thick nanosheets, which will significantly enrich the species of inorganic graphene analogues and optimize energy storage by reasonable materials design and fabrication.
Introducing the synergy effect of magnetic properties and band gap engineering is highly desired for two-dimensional (2D) nanosheets. Here, we prepare metal-free ternary 2D carbon (C) doped boron ...nitride (BN) nanosheets (BCN) with band gap engineering and magnetic properties by a synergetic way. The substitutional occupation of C atoms, as revealed by X-ray absorption spectrum, in BCN nanosheets induces tunable band gap reduction (5.5 eV to 2.6 eV) and intensive intrinsic ferromagnetism at room temperature. First-principle calculations also reveal that substituted C atoms in BCN nanosheets can broaden the light adsorption region and reduce the optical band gap, and ferromagnetic ordering is energetically more favorable than antiferromagnetic. This design opens up new possibility for synergetic manipulation of exchange interactions and band gap engineering in 2D nanostructures.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Abstract The solvent-free selective hydrogenation of nitroaromatics to azoxy compounds is highly important, yet challenging. Herein, we report an efficient strategy to construct individually ...dispersed Co atoms decorated on niobium pentaoxide nanomeshes with unique geometric and electronic properties. The use of this supported Co single atom catalysts in the selective hydrogenation of nitrobenzene to azoxybenzene results in high catalytic activity and selectivity, with 99% selectivity and 99% conversion within 0.5 h. Remarkably, it delivers an exceptionally high turnover frequency of 40377 h –1 , which is amongst similar state-of-the-art catalysts. In addition, it demonstrates remarkable recyclability, reaction scalability, and wide substrate scope. Density functional theory calculations reveal that the catalytic activity and selectivity are significantly promoted by the unique electronic properties and strong electronic metal-support interaction in Co 1 /Nb 2 O 5 . The absence of precious metals, toxic solvents, and reagents makes this catalyst more appealing for synthesizing azoxy compounds from nitroaromatics. Our findings suggest the great potential of this strategy to access single atom catalysts with boosted activity and selectivity, thus offering blueprints for the design of nanomaterials for organocatalysis.
The p53 family consists of p53, p63, and p73, each of which has multiple isoforms due to transcription at two separate promoters and alternative splicing. Although p53 is a bona fide tumor ...suppressor, p63 appears to have a Janus-faced function as a tumor suppressor and an oncogene. To address the two opposing functions of p63, we analyzed its target genes. Here, we found that GPX2, which encodes a glutathione peroxidase, is up-regulated by p63 but not p53. Accordingly, a unique responsive element was found in the promoter of the GPX2 gene that can be activated and bound by p63 but not p53. We also found that upon overexpression, GPX2 alleviates the apoptotic response of MCF7 cells to oxidative stresses. Interestingly, the protective function of GPX2 is p53 dependent. Likewise, we showed that a deficiency in GPX2 renders MCF7 cells susceptible to oxidative stress-induced apoptosis. Given that the ΔN isoform of p63 is frequently overexpressed in tumor cells, the observations here provide an insight into the mechanism by which some isoforms of p63 serve as a pro-survival factor by up-regulating GPX2 to reduce the p53-dependent oxidative stress-induced apoptotic response.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In order to properly manage lithium-ion batteries of electric vehicles (EVs), it is essential to build the battery model and estimate the state of charge (SOC). In this paper, the fractional order ...forms of Thevenin and partnership for a new generation of vehicles (PNGV) models are built, of which the model parameters including the fractional orders and the corresponding resistance and capacitance values are simultaneously identified based on genetic algorithm (GA). The relationships between different model parameters and SOC are established and analyzed. The calculation precisions of the fractional order model (FOM) and integral order model (IOM) are validated and compared under hybrid test cycles. Finally, extended Kalman filter (EKF) is employed to estimate the SOC based on different models. The results prove that the FOMs can simulate the output voltage more accurately and the fractional order EKF (FOEKF) can estimate the SOC more precisely under dynamic conditions.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The effects of testosterone propionate (TP) on the oxidative stress and mitochondrial function, as well as on mitochondria associated apoptotic signaling, were analyzed in the gastric mucosa in ...orchiectomized male rats. The present study showed that testosterone deficiency triggered apoptosis by damaging the mitochondrial function (ROS overload generation, membrane potential loss, ATP depletion, etc.), increasing both the release of mitochondrial cytochrome c (Cyt c) and the Bax/Bcl-2 ratio, and activating caspase-9 and caspase-3. Supplements of testosterone propionate to castrated male rats ameliorated mitochondrial function and confirmed the involvement of the mitochondrial pathway in the gastric mucosa. These results suggest that testosterone could maintain the mitochondrial function of the gastric mucosa and mediate mitochondria-associated apoptotic signaling.
•Testosterone deficiency cause mitochondrial damage in the gastric mucosa of rats.•Testosterone alleviates mitochondrial ROS accumulation in the gastric mucosa of rats.•Testosterone could mediate mitochondria-associated apoptotic signaling.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
The activity of electrocatalyst is dominant by the spin configuration of active sites, which is strongly related to its local structure. Herein, for the first time, the intrinsic relationships among ...local structural distortion, spin configuration and oxygen evolution reaction (OER) activity of the sample are systematically studied by taking the solid solution of transition metal tungstates (CoxFe1-xWO4) with tunable degrees of local structural distortions as a platform, and proposed that the local structural distortion induced spin transition is account for its high catalytic activity. Benefiting from the co-presence of high spin and low spin states, the Co0.708Fe0.292WO4 exhibits the best OER activity among all samples with a small overpotential of 327 mV for 10 mA cm−2 and a large current density of 254 mA cm−2 at 1.825 V (vs RHE) in 1 M KOH solution. This work introduces a deeply understanding on the role of local structural distortion played in OER process.
The local structural distortion induced spin transition could realize optimal spin configuration for electrocatalytic oxygen evolution in solid solution of transition metal tungstates, which introduces a deeply understanding on the role of local structural distortion played in OER process. Display omitted
•We firstly show that the local structural distortion induced spin transition from high spin to low spin states in the solid solution was account for its enhanced electrocatalytic activity.•The eg filling of Co0.708Fe0.292WO4 with the smallest local structural distortion was decreased from 2.0 to near unity, resulting in decreased resistance of the sample.•The Co0.708Fe0.292WO4 with optimal spin configuration exhibits the best OER activity among all samples with 254 mA cm−21.825 V a small overpotential of 327 mV at 10 mA cm−2.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
Since the rise of two-dimensional (2D) semiconductors, it seems that the electronic devices will soon be upgraded with spintronics, in which the manipulation of spin degree of freedom endows it ...obvious advantages over conventional charge-based electronics. However, as the most crucial prerequisite for the above-mentioned expectation, 2D semiconductors with adjustable magnetic interaction are still rare which has greatly hampered the promotion of spintronics. Recently, the transition metal phosphates have attracted tremendous interest due to their intrinsic antiferromagnetism and potential applications in spintronics. Herein, the parasitic ferromagnetism is achieved for the first time by exfoliating the antiferromagnetic chalcogenophosphate to few layers. Taking transition-metal chalcogenophosphate Mn2P2S6 as an example, the antiferromagnetic transition at Néel temperature is completely suppressed and the magnetic behaviors of the as-obtained few-layered Mn2P2S6 are dominated by parasitic ferromagnetism. We experimentally verify an electron redistribution that part of Mn 3d electrons migrate and redistribute on P atoms in few-layered Mn2P2S6 due to the introduced Mn vacancies. The results demonstrated here broaden the tunability of the material's magnetic properties and open up a new strategy to rationally design the magnetic behaviors of 2D semiconductors, which could accelerate the applications of spintronics.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
The development of two-dimensional (2D) magnetic semiconductors with room-temperature ferromagnetism is a significant challenge in materials science and is important for the development of ...next-generation spintronic devices. Herein, we demonstrate that a 2D semiconducting antiferromagnetic Cu-MOF can be endowed with intrinsic room-temperature ferromagnetic coupling using a ligand cleavage strategy to regulate the inner magnetic interaction within the Cu dimers. Using the element-selective X-ray magnetic circular dichroism (XMCD) technique, we provide unambiguous evidence for intrinsic ferromagnetism. Exhaustive structural characterizations confirm that the change of magnetic coupling is caused by the increased distance between Cu atoms within a Cu dimer. Theoretical calculations reveal that the ferromagnetic coupling is enhanced with the increased Cu-Cu distance, which depresses the hybridization between 3
d
orbitals of nearest Cu atoms. Our work provides an effective avenue to design and fabricate MOF-based semiconducting room-temperature ferromagnetic materials and promotes their practical applications in next-generation spintronic devices.
p21, a cyclin-dependent kinase inhibitor, is transcriptionally regulated by the p53 family to induce cell cycle arrest. p21 is also regulated post-transcriptionally upon DNA damage in a p53-dependent ...manner, but the mechanism is uncertain. Here, we found that RNPC1, an RNA-binding protein and a target of the p53 family, is required for maintaining the stability of the basal and stress-induced p21 transcript. Specifically, we showed that RNPC1 is induced by the p53 family and DNA damage in a p53-dependent manner. The RNPC1 gene encodes at least two alternative spliced isoforms, RNPC1a and RNPC1b, both of which contain an intact RNA recognition motif. Interestingly, we found that RNPC1a, but not RNPC1b, induces cell cycle arrest in G1, although both isoforms are expressed in the nucleus and cytoplasm. In addition, we found that while both isoforms directly bind to the 3' untranslated region in p21 transcript, only RNPC1a is able to stabilize both the basal and stress-induced p21 transcripts. Conversely, RNPC1a knockdown destabilizes p21 transcript. Finally, we found that RNPC1a is required to maintain the stability of p21 transcript induced by p53.
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