Unveiling the impact of a single parameter on the catalytic descriptor is fundamental to guide rational design principles for high‐activity catalysts. Facets with distinct surface coordination that ...exhibit a central role in the kinetics modulation (reactivity) of surface electrochemistry, have remained elusive in oxygen evolution reactions (OERs). Here, the relationship between the predominant facets and catalytic reactivity is revealed, and it is recognized that facets decisively govern the oxygen evolution activity descriptor in hematite nanocrystals. Specifically, the hematite shows facet‐dependent activity that follows the computed binding energy of surface‐oxygenated intermediates. Moreover, a lower kinetics energy barrier is observed on a highly coordinated surface, both experimentally and computationally, in the light of molecular orbital principles. Consequently, a record‐low overpotential and Tafel slope in iron oxides toward OER are manifested, competing against the benchmark binary transition metal oxide electrocatalysts and expelling the stereotype of the passive oxygen evolution activity of iron oxides. Significantly, the identification of facet‐governing reactivity, construction of favorable facets, and strategic regulation of surface covalency enlighten design strategies for highly active catalysts.
Facet‐governing reactivity toward oxygen evolution is identified in hematites, where three facet‐enclosed nanocrystals show distinct activity that follows computed trends. The favorable high‐index (012) facet hematite nanocrystal exhibits high activity, expelling the stereotype passiveness of iron oxides toward oxygen evolution.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Promoting copper catalysts with C60Ethylene glycol, a commodity chemical used as a feedstock and antifreeze agent, is synthesized industrially from dimethyl oxalate (DMO) by hydrogenation over ...precious-metal palladium catalysts at high pressures (typically 20 bars). Copper-chromium catalysts supported on silica as an alternative have required even high pressures. Zheng et al. show the addition of fullerene (C60) onto copper-silica allows DMO hydrogenation to be performed at ambient pressures with high yield (98%) and without deactivation after 1000 hours (see the Perspective by Gravel and Doris). The use of C60 to stabilize electron-deficient copper species that enhance hydrogen adsorption could likely be applied to other hydrogenation reactions catalyzed by copper. —PDS
B′ is a common type of metastable precipitate in over-aged Al-Mg-Si alloys, which is long regarded as a variation of the Q precipitate in Al-Mg-Si-Cu alloys due to the similarity between their ...lattice parameters. Atomic-resolution high angle annular dark field scanning transmission electron microscopy and energy dispersive X-ray elemental mapping at low beam damage conditions, as well as first-principles calculations were used to explore the atomistic structure of B′. It has a hexagonal unit cell with a space group P6¯ and lattice parameters a= 10.3(1) Å, c = 4.05 Å. The M sites in B′, which are analogous to Cu sites in the Q structure, were inferred with 50% Si atoms and 50% vacancies. The chemical nature of other sites agrees well with the model predicted by Ravi et al. The determined model Al3Mg9Si8 has the lowest formation enthalpy and the smallest lattice misfit with the Al matrix along the 0001 growth direction. Step-like boundaries with alternately arranged Mg-Si-Mg-Si atoms were observed at the coherent interfaces (101¯0)B′ // (5¯10)Al. A layer of defect structures sandwiched in the B′ precipitate was found geometrically necessary to allow both (5¯10)Al interfaces to arrange coherently in 3 dimensions and thus to relieve the strain of the surrounding matrix. The transformation from U1 → U2 → B′ was evidenced and the reverse transformation B′ → U2 nucleating at the incoherent B′/Al interfaces (150)Al is also likely. These results will provide new insight into the aging precipitation and compositional design of Al-Mg-Si(-Cu) alloys.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Autophagic degradation of the endoplasmic reticulum (ER-phagy) is triggered by ER stress in diverse organisms. However, molecular mechanisms governing ER stress-induced ER-phagy remain insufficiently ...understood. Here we report that ER stress-induced ER-phagy in the fission yeast Schizosaccharomyces pombe requires Epr1, a soluble Atg8-interacting ER-phagy receptor. Epr1 localizes to the ER through interacting with integral ER membrane proteins VAPs. Bridging an Atg8-VAP association is the main ER-phagy role of Epr1, as it can be bypassed by an artificial Atg8-VAP tether. VAPs contribute to ER-phagy not only by tethering Atg8 to the ER membrane, but also by maintaining the ER-plasma membrane contact. Epr1 is upregulated during ER stress by the unfolded protein response (UPR) regulator Ire1. Loss of Epr1 reduces survival against ER stress. Conversely, increasing Epr1 expression suppresses the ER-phagy defect and ER stress sensitivity of cells lacking Ire1. Our findings expand and deepen the molecular understanding of ER-phagy.
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•Epr1 is a soluble ER-phagy receptor critical for ER stress-induced ER-phagy•The main role of Epr1 is to bridge the association between Atg8 and VAPs•VAP-mediated ER-plasma membrane contact is important for ER stress-induced ER-phagy•UPR regulator Ire1 contributes to ER stress-induced ER-phagy by upregulating Epr1
Zhao et al. show that the fission yeast protein Epr1 confers resistance to ER stress by promoting the autophagic degradation of the ER (ER-phagy). Epr1 acts as a bridging molecule to mediate the association between Atg8 on the autophagic membrane and the integral membrane proteins VAPs on the ER.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Northeast China is the leading grain production region in China where one-fifth of the national grain is produced; however, consistent and reliable crop maps are still unavailable, impeding crop ...management decisions for regional and national food security. Here, we produced annual 10-m crop maps of the major crops (maize, soybean, and rice) in Northeast China from 2017 to 2019, by using (1) a hierarchical mapping strategy (cropland mapping followed by crop classification), (2) agro-climate zone-specific random forest classifiers, (3) interpolated and smoothed 10-day Sentinel-2 time series data, and (4) optimized features from spectral, temporal, and texture characteristics of the land surface. The resultant maps have high overall accuracies (OA) spanning from 0.81 to 0.86 based on abundant ground truth data. The satellite estimates agreed well with the statistical data for most of the municipalities (R
≥ 0.83, p < 0.01). This is the first effort on regional annual crop mapping in China at the 10-m resolution, which permits assessing the performance of the soybean rejuvenation plan and crop rotation practice in China.
Killer meiotic drivers (KMDs) skew allele transmission in their favor by killing meiotic progeny not inheriting the driver allele. Despite their widespread presence in eukaryotes, the molecular ...mechanisms behind their selfish behavior are poorly understood. In several fission yeast species, single-gene KMDs belonging to the wtf gene family exert selfish killing by expressing a toxin and an antidote through alternative transcription initiation. Here we investigate how the toxin and antidote products of a wtf-family KMD gene can act antagonistically. Both the toxin and the antidote are multi-transmembrane proteins, differing only in their N-terminal cytosolic tails. We find that the antidote employs PY motifs (Leu/Pro-Pro-X-Tyr) in its N-terminal cytosolic tail to bind Rsp5/NEDD4 family ubiquitin ligases, which ubiquitinate the antidote. Mutating PY motifs or attaching a deubiquitinating enzyme transforms the antidote into a toxic protein. Ubiquitination promotes the transport of the antidote from the trans-Golgi network to the endosome, thereby preventing it from causing toxicity. A physical interaction between the antidote and the toxin enables the ubiquitinated antidote to translocate the toxin to the endosome and neutralize its toxicity. We propose that post-translational modification-mediated protein localization and/or activity changes may be a common mechanism governing the antagonistic duality of single-gene KMDs.
Abstract
In this study, we employed a recall test to investigate how memory load affects the learning curve of gesture-letter pairs for younger and older users. The gesture-letter pairs were ...carefully designed to mimic real-world gesture-function/command associations on a touchscreen mobile phone. Both younger and older user groups showed lower recall accuracy as the memory load of gesture-letter pairs increased, and recall performance improved with repeated memory training. More specifically, younger users improved rapidly over repeated memory sessions under all memory loads, whereas older users benefited much less from repeated memory sessions except the lowest memory load of 6 gesture-letter pairs. These results reveal that the memory load differentially modulated younger and older users’ learning curves of gesture-letter pairs. Thus, our work suggests an upper limit when adding new gesture-function associations on mobile phones and special attention should be devoted to old users.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Aptamers are short non-coding, single-stranded oligonucleotides (RNA or DNA) developed through Systematic Evolution of Ligands by Exponential enrichment (SELEX) in vitro. Similar to antibodies, ...aptamers can bind to specific targets with high affinity, and are considered promising therapeutic agents as they have several advantages over antibodies, including high specificity, stability, and non-immunogenicity. Furthermore, aptamers can be produced at a low cost and easily modified, and are, therefore, called "chemical antibodies". In the past years, a variety of aptamers specifically bound to both breast cancer biomarkers and cells had been selected. Besides, taking advantage of nanomaterials, there were a number of aptamer-nanomaterial conjugates been developed and widely investigated for diagnostics and targeted therapy of breast cancer. In this short review, we first present a systematical review of various aptamer selection methods. Then, various aptamer-based diagnostic and therapeutic strategies of breast cancer were provided. Finally, the current problems, challenges, and future perspectives in the field were thoroughly discussed.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Background The neonatal heart maintains its entire regeneration capacity within days after birth. Using quantitative phosphoproteomics technology, we identified that SGK3 (serine/threonine-protein ...kinase 3) in the neonatal heart is highly expressed and activated after myocardial infarction. This study aimed to uncover the function and related mechanisms of SGK3 on cardiomyocyte proliferation and cardiac repair after apical resection or ischemia/reperfusion injury. Methods and Results The effect of SGK3 on proliferation and oxygen glucose deprivation/reoxygenation- induced apoptosis in isolated cardiomyocytes was evaluated using cardiomyocyte-specific SGK3 overexpression or knockdown adenovirus5 vector. In vivo, gain- and loss-of-function experiments using cardiomyocyte-specific adeno-associated virus 9 were performed to determine the effect of SGK3 in cardiomyocyte proliferation and cardiac repair after apical resection or ischemia/reperfusion injury. In vitro, overexpression of SGK3 enhanced, whereas knockdown of SGK3 decreased, the cardiomyocyte proliferation ratio. In vivo, inhibiting the expression of SGK3 shortened the time window of cardiac regeneration after apical resection in neonatal mice, and overexpression of SGK3 significantly promoted myocardial repair and cardiac function recovery after ischemia/reperfusion injury in adult mice. Mechanistically, SGK3 promoted cardiomyocyte regeneration and myocardial repair after cardiac injury by inhibiting GSK-3β (glycogen synthase kinase-3β) activity and upregulating β-catenin expression. SGK3 also upregulated the expression of cell cycle promoting genes G1/S-specific cyclin-D1, c-myc (cellular-myelocytomatosis viral oncogene), and cdc20 (cell division cycle 20), but downregulated the expression of cell cycle negative regulators cyclin kinase inhibitor P 21 and cyclin kinase inhibitor P 27. Conclusions Our study reveals a key role of SGK3 on cardiac repair after apical resection or ischemia/reperfusion injury, which may reopen a novel therapeutic option for myocardial infarction.
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