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Sintering of active metal species often happens during catalytic reactions, which requires redispersion in a reactive atmosphere at elevated temperatures to recover the activity. Herein, we report a simple method to redisperse sintered Cu catalysts via O 2 -H 2 O treatment at room temperature. In-situ spectroscopic characterizations reveal that H 2 O induces the formation of hydroxylated Cu species in humid O 2 , pushing surface diffusion of Cu atoms at room temperature. Further, surface OH groups formed on most hydroxylable support surfaces such as γ-Al 2 O 3 , SiO 2 , and CeO 2 in the humid atmosphere help to pull the mobile Cu species and enhance Cu redispersion. Both pushing and pulling effects of gaseous H 2 O promote the structural transformation of Cu aggregates into highly dispersed Cu species at room temperature, which exhibit enhanced activity in reverse water gas shift and preferential oxidation of carbon monoxide reactions. These findings highlight the important role of H 2 O in the dynamic structure evolution of supported metal nanocatalysts and lay the foundation for the regeneration of sintered catalysts under mild conditions. Redispersion of sintered metal species requires high temperatures in reactive atmospheres. Here, the authors report room temperature redispersion of supported Cu particles via formation of mobile hydroxylated Cu species induced by gaseous H 2 O and anchoring of the Cu species by surface OH groups.

Relationships between leaf traits and carbon assimilation rates are commonly used to predict primary productivity at scales from the leaf to the globe. We addressed how the shape and magnitude of these relationships vary across temporal, spatial and taxonomic scales to improve estimates of carbon dynamics. Photosynthetic CO2 and light response curves, leaf nitrogen (N), chlorophyll (Chl) concentration and specific leaf area (SLA) of 25 grassland species were measured. In addition, C3 and C4 photosynthesis models were parameterized using a novel hierarchical Bayesian approach to quantify the effects of leaf traits on photosynthetic capacity and parameters at different scales. The effects of plant physiological traits on photosynthetic capacity and parameters varied among species, plant functional types and taxonomic scales. Relationships in the grassland biome were significantly different from the global average. Within-species variability in photosynthetic parameters through the growing season could be attributed to the seasonal changes of leaf traits, especially leaf N and Chl, but these responses followed qualitatively different relationships from the across-species relationship. The results suggest that one broad-scale relationship is not sufficient to characterize ecosystem condition and change at multiple scales. Applying trait relationships without articulating the scales may cause substantial carbon flux estimation errors.

Ion secretion facilitates recretohalophytes to tolerate saline and drought conditions but its relative contribution to the survival of many species remains poorly understood. Tamarix chinensis has high potential for restoration of saline deteriorated lands. The water management and high salt tolerance of the plant have highlighted the need to determine the strategies that govern these mechanisms. Here we report the selectivity of this halophyte to transport, utilize, and secrete different cations and anions under various NaCl (0, 100, 200 and 400 mM) concentrations. Plant growth, photosynthesis and antioxidant defense responses were also determined to relate them with the function of ion secretion. Results reflected two different sets of strategies adopted by plants to survive low and high salinities. Exposure to highly saline conditions caused reduction in photosynthesis due to stomatal and biochemical limitations. The decreased content of photosynthetic pigments exposed plants to excessive light energy that accelerated production of ROS (i.e., hydrogen peroxide H2O2) and caused damage to cellular membranes. The increased activities of anti-oxidative enzymes (superoxide-dismutase, catalase, ascorbate-peroxidase, and glutathione-reductase) were insufficient to detoxify H2O2. In contrast, plants treated with low salinity did not face stomatal limitations while the photosynthetic pigments increased. As no damage to membranes was detected, the increased content of H2O2 was postulated for its messenger role. The assimilation of essential nutrients was affected due to increased content of toxic ions (Na+ and Cl−) in the growing medium and within the plants. However, the ability to regulate K+ facilitated plants to improve water use efficiency under hyper-osmotic environment. The removal of toxic ions from the photosynthesizing tissues demands high energy, which was evident in the compromised growth of plants. This study offers a window to physiological mechanisms, e.g., potassium retention that ensure salt secretion as a beneficial strategy for prolonged survival of T. chinensis.

Small mammal species play an important role influencing vegetation primary productivity and plant species composition, seed dispersal, soil structure, and as predator and/or prey species. Species which experience population dynamics cycles can, at high population phases, heavily impact agricultural sectors and promote rodent-borne disease transmission. To better understand the drivers behind small mammal distributions and abundances, and how these differ for individual species, it is necessary to characterise landscape variables important for the life cycles of the species in question. In this study, a suite of Earth observation derived metrics quantifying landscape characteristics and dynamics, and in-situ small mammal trapline and transect survey data, are used to generate random forest species distribution models for nine small mammal species for study sites in Narati, China and Sary Mogul, Kyrgyzstan. These species distribution models identify the important landscape proxy variables driving species abundance and distributions, in turn identifying the optimal conditions for each species. The observed relationships differed between species, with the number of landscape proxy variables identified as important for each species ranging from 3 for Microtus gregalis at Sary Mogul, to 26 for Ellobius tancrei at Narati. Results indicate that grasslands were predicted to hold higher abundances of Microtus obscurus , E . tancrei and Marmota baibacina , forest areas hold higher abundances of Myodes centralis and Sorex asper , with mixed forest—grassland boundary areas and areas close to watercourses predicted to hold higher abundances of Apodemus uralensis and Sicista tianshanica . Localised variability in vegetation and wetness conditions, as well as presence of certain habitat types, are also shown to influence these small mammal species abundances. Predictive application of the Random Forest (RF) models identified spatial hot-spots of high abundance, with model validation producing R 2 values between 0.670 for M . gregalis transect data at Sary Mogul to 0.939 for E . tancrei transect data at Narati. This enhances previous work whereby optimal habitat was defined simply as presence of a given land cover type, and instead defines optimal habitat via a combination of important landscape dynamic variables, moving from a human-defined to species-defined perspective of optimal habitat. The species distribution models demonstrate differing distributions and abundances of host species across the study areas, utilising the strengths of Earth observation data to improve our understanding of landscape and ecological linkages to small mammal distributions and abundances.

Background  Type 2 diabetes (T2D) is an independent risk factor for Alzheimer's disease (AD). Exendin-4 (Ex-4), a widely used glucagon-like peptide-1 receptor agonist drug in the treatment of T2D, has been demonstrated the therapeutic effects on diabetic encephalopathy (DE). Especially, the Ex-4 ameliorates the tau hyperphosphorylation and cognitive impairment in DE. And these crucial alterations are also important bridge between T2D and AD. However, its unique mechanism is unclear. Methods  The db/db mice, high-fat-diet (HFD) / streptozotocin (STZ)—induced diabetic (HF-diabetic) mice, and high-glucose-damaged (HGD) HT-22 hippocampal cells were enrolled to examine the effects of Ex-4 on AD-like changes in T2D. The Novel object recognition test (NORT) and Morris water maze test (MWMT) were conducted to evaluate the cognitive impairment. The Dickkopf-1 (DKK1) was employed to weaken the activation of the Wnt/β-catenin pathway to explore the mechanism of Ex-4 in protecting the brain functions. The JASPAR was based to predict the interaction between NeuroD1 and the promoter region of Ins2 . Moreover, the chromatin immunoprecipitation coupled with quantitative polymerase chain reaction (ChIP-qPCR) and luciferase reporter assays were performed. Results  Ex-4 alleviated the tau hyperphosphorylation, increased the brain-derived insulin, and improved the PI3K/AKT/GSK3-β signalling in db/db mice, HF-diabetic mice, and HGD HT-22 hippocampal neuronal cells. The NORT and MWMT indicated that Ex-4 alleviated the learning and memory deficits in HF-diabetic mice. The inhibitor Dickkopf-1 (DKK1) of the Wnt/β-catenin pathway significantly blocked the protective effects of Ex-4. Regarding further molecular mechanisms, NeuroD1 was affected by Ex-4 in vivo and in vitro, and the knockdown or overexpression of NeuroD1 suggested its crucial role in promoting the brain insulin by Ex-4. Meanwhile, the ChIP‒qPCR and luciferase reporter assays confirmed the combination between NeuroD1 and the promoter region of the insulin-encoding gene  Ins2 . And this interaction could be promoted by Ex-4. Conclusions Our study proposes that Ex-4 alleviates tau hyperphosphorylation and cognitive dysfunction by increasing  Ins2 -derived brain insulin through the Wnt/β-catenin/NeuroD1 signaling in T2D. And its also show new lights on part of the progress and mechanism on treatment targets for the DE in T2D.

In relapsed/refractory acute myeloid leukemia (R/R-AML), hypoxia-driven chemoresistance is orchestrated by HIF-1α-induced P-glycoprotein (P-gp) overexpression and subsequent lysosomal sequestration of anthracyclines. Nuclear-cytoplasmic shuttling of the HIF-1α prolyl-hydroxylase PHD2 is controlled by chromosome region maintenance 1 (CRM1), which is frequently up-regulated in AML; however, whether pharmacologic CRM1 inhibition restores PHD2 nuclear availability to accelerate HIF-1α degradation and reverse chemoresistance remains undefined. AML cell lines (MV4-11 and MOLM13) were cultured under normoxic or hypoxic conditions. The effects of hypoxia on drug sensitivity, intracellular drug distribution, and protein expression were assessed using CCK-8 assays, immunofluorescence, Western blot, and flow cytometry. Genetic and pharmacological inhibition of P-gp, HIF-1α, and CRM1 was performed to validate their roles in chemoresistance. Hypoxia-adapted zebrafish CHT xenografts were employed for validation. Hypoxia reduced AML cell sensitivity to DNR, increased HIF-1α and P-gp expression, and promoted lysosomal sequestration of DNR. Inhibition of P-gp or HIF-1α reversed these effects. CRM1 and PHD2 expression increased under hypoxia, but nuclear accumulation of PHD2 decreased. Selinexor restored PHD2 nuclear localization, promoted HIF-1α degradation, reduced P-gp expression, and enhanced DNR nuclear accumulation. Combination treatment with Selinexor and DNR significantly increased apoptosis and DNA damage and reduced leukemia burden in zebrafish xenografts. CRM1 inhibition by Selinexor re-establishes nuclear PHD2 residency, increases the degradation of HIF-1α in hypoxia, abrogates P-gp-mediated lysosomal anthracycline trapping, and confers potent and chemosensitization. These data provide mechanistic rationale for integrating Selinexor into salvage regimens for R/R-AML.

ZnCrO x oxides coupled with zeolites (OXZEO) allow direct conversion of syngas into light olefins, while active sites in the composite oxides remain elusive. Herein, we find that ZnO particles physically mixed with ZnCr 2 O 4 spinel particles can be well dispersed onto the spinel surfaces by treatment in syngas and through a reduction-evaporation-anchoring mechanism, forming monodispersed ZnO x species with uniform thickness or dimension on ZnCr 2 O 4 up to a dispersion threshold ZnO loading of 16.0 wt% (ZnCr 2 O 4 @ZnO x ). A linear correlation between CO conversion and surface ZnO loading clearly confirms that the ZnO x overlayer on ZnCr 2 O 4 acts as the active structure for the syngas conversion, which can efficiently activate both H 2 and CO. The obtained ZnCr 2 O 4 @ZnO x catalyst combined with SAPO-34 zeolite achieves excellent catalytic performance with 64% CO conversion and 75% light olefins selectivity among all hydrocarbons. Moreover, the ZnO x overlayer is effectively anchored on the ZnCr 2 O 4 spinel, which inhibits Zn loss during the reaction and demonstrates high stability over 100 hours. Thus, a significant interface confinement effect is present between the spinel surface and the ZnO x overlayer, which helps to stabilize ZnO x active structure and enhance the catalytic performance. Identifying active sites on oxide catalysts is often challenging. Here, the authors introduce a syngas-induced dispersion method to anchor ZnO species onto ZnCr 2 O 4 , forming monodispersed ZnO x active sites that enhance catalytic performance in direct syngas conversion to light olefins.

Hydrogen spillover has been extensively studied in heterogeneous catalysis, whereas the analogous migration of metal species remains largely underexplored. Here, we report a spillover phenomenon for metal species, exemplified by copper, which spontaneously migrates across physically contacted hydrophilic supports under humid ambient conditions. This process is facilitated by water adlayers on support surfaces, which act as molecular bridges to enable surface and interfacial migration of cooper species via hydroxylated intermediates. The phenomenon is universal across diverse supports, including oxides, carbides, and sulfides, and extends to metals such as ruthenium, cobalt, and nickel. Remarkably, catalysts prepared via this spillover approach exhibit substantially enhanced low-temperature activity in reactions including carbon monoxide oxidation, reverse water-gas shift, selective catalyst reduction with ammonia, and hydrogen cyanide oxidation, outperforming counterparts prepared by conventional impregnation. This work redefines the spillover phenomenon by extending it to metal species through water adlayer-mediated migration, opening new avenues for the design of dynamic catalysts. While hydrogen spillover has been widely investigated in heterogeneous catalysis, the migration of metal species via a similar mechanism remains poorly understood. Here, the authors reveal a metal-species spillover process enabled by water adlayers on support surfaces.

Boron (B) fertilization significantly increased soybean seed yields and is an indispensable micronutrient in soybean growth. However, it is difficult to absorb in soil, which can seriously affect soybean growth. In this study, soybeans were planted under B deficiency and B sufficiency conditions, then physiological and biochemical indicators of soybean seedlings were measured. The results indicated that the antioxidant enzyme activity (SOD, POD, CAT, APX) and malondialdehyde content increased considerably compared with their controls in the leaves and roots, respectively. Among these, the difference in the roots was more significant than in the leaves, suggesting that the root system was more sensitive. Therefore, soybean roots under B stress for 12 hours and 8 days were selected to construct the miRNA library for sequencing. In the three comparison groups, 55 miRNAs were differentially expressed in response to B stress, 22 known miRNAs, and 33 novel miRNAs were identified. Through mRNA-miRNA meta-analysis, miRNA-objective gene pairs consisting of 21 DEGs and 11 miRNAs were identified. The GO functional annotation indicated that stress response genes were mostly concentrated in the items of enzyme activity, ion transport, and metabolic processes, etc. In KEGG of 8d, the objective genes were drastically enriched cyanoamino acid metabolism, glycine, serine and threonine metabolism, phenylalanine metabolism, etc. We further constructed the pathway for cyanide amino acid metabolism under B stress and found that miR408c-5p targeted the gene controlling β -glucosidase 18, and the expression level was notably decreased. It was speculated that B stress hindered soybean growth by inhibiting amino acid metabolism and affecting other metabolic pathways. This study combined miRNAs and mRNAs to identify DEMs and metabolic pathways correlated to B stress. This study provides information that will help elucidate the complex mechanism of the B stress response in soybeans. Moreover, candidate miRNAs and mRNAs could yield new strategies for the development of B-tolerant soybean breeding.