Pd1Cu Single-Atom Alloys for High-Current-Density and Durable NO-to-NH3 Electroreduction.

Electrochemical reduction of NO to NH3 (NORR) offers a prospective method for efficient NH3 electrosynthesis. Herein, we first design single-atom Pd-alloyed Cu (Pd1Cu) as an efficient and robust NORR catalyst at industrial-level current densities (>0.2 A cm-2). Operando spectroscopic characterizations and theoretical computations unveil that Pd1 strongly electronically couples its adjacent two Cu atoms (Pd1Cu2) to enhance the NO activation while promoting the NO-to-NH3 protonation energetics and suppressing the competitive hydrogen evolution. Consequently, the flow cell assembled with Pd1Cu exhibits an unprecedented NH3 yield rate of 1341.3 µmol h-1 cm-2 and NH3-Faradaic efficiency of 85.5% at an industrial-level current density of 210.3 mA cm-2, together with an excellent long-term durability for 200 h of electrolysis, representing one of the highest NORR performances on record.

Exosomal transfer of activated neutrophil-derived lncRNA CRNDE promotes proliferation and migration of airway smooth muscle cells in asthma.

Activated neutrophil-derived exosomes reportedly contribute to the proliferation of airway smooth muscle cells (ASMCs), thereby aggravating the airway wall remodeling during asthma; however, the specific mechanism remains unclear. Lipopolysaccharide (LPS)-EXO and si-CRNDE-EXO were extracted from the media of human neutrophils treated with LPS and LPS + si-CRNDE (a siRNA targets long non-coding RNA CRNDE), respectively. Human ASMCs were co-cultured with LPS-EXO or si-CRNDE-EXO, and cell viability, proliferation and migration were measured. The interplay of colorectal neoplasia differentially expressed (CRNDE), inhibitor of nuclear factor kappa B kinase subunit beta (IKKß) and nuclear receptor subfamily 2 group C member 2 (TAK1) was explored using RNA immunoprecipitation (RIP) and Co-IP assays. A mouse model of asthma was induced using ovalbumin. CRNDE was upregulated in LPS-EXO and successfully transferred from LPS-treated neutrophils to ASMCs through exosome. Mechanically, CRNDE loaded in LPS-EXO reinforced TAK1-mediated IKKß phosphorylation, thereby activating the nuclear factor kappa B (NF-κB) pathway. Functionally, silencing CRNDE in LPS-EXO, an IKKß inhibitor, and an NF-κB inhibitor all removed the upregulation of cell viability, proliferation and migration induced by LPS-EXO in ASMCs. In the end, the in vivo experiment demonstrated that CRNDE knockdown in neutrophils effectively reduced the thickness of bronchial smooth muscle in a mouse model for asthma. Activated neutrophils-derived CRNDE was transferred to ASMCs through exosomes and activated the NF-κB pathway by enhancing IKKß phosphorylation. The latter promoted the proliferation and migration of ASMCs and then contributed to airway remodeling in asthma.

Evaporation Dynamics of Macro- and Nanodroplets on Heated Hydrophilic Rough Substrates: The Effect of Roughness and Scale.

Droplet evaporation on rough substrates plays an essential role in cooling and micro/nanoparticle assembly. Currently, there are numerous macroscopic experiments and theoretical models to investigate the droplet evaporation behavior on rough substrates. However, due to the complexity of this phenomenon, understanding its mechanisms solely through macroscale studies is difficult. To this end, molecular dynamics simulations of the models with distinct roughness factors are performed, and the obtained results are compared with those of relevant experiments of droplet evaporation on three hydrophilic substrates with different roughness average of 0.1, 0.15, and 0.2 µm, respectively. In this way, we assess the evaporation on these rough systems and the effect of scale on macro- and nanodroplets, which allows us to explore deeper the mechanism of droplet evaporation on rough hydrophilic substrates. In particular, we find that in the case of macroscale droplets, the evaporation mode remains the same with increasing roughness, pointing to a combined mixed and constant-contact-radius (CCR) mode. In the case of nanoscale droplets, the evaporation model is the constant-contact-angle mode when the roughness factor r = 1, while the mixed and CCR modes are found for r = 1.5 and 2, respectively. The scale effect has significant influence on the evaporation pattern of droplets on rough hydrophilic substrates. Moreover, it is also found that increasing the roughness of substrates expands the substrate-droplet contact area on both the macro- and nanoscale, which in turn enhances the heat transfer from the substrate toward the droplet. We anticipate that this first systematic analysis of scale effects provides further insights into the evaporation dynamics of droplets on rough hydrophilic substrates and has significant implications for the advancement of nanotechnology.

Promoting Nitrite-to-Ammonia Electroreduction over Amorphous CoS2 Nanorods.

Electrocatalytic nitrite reduction to ammonia (NO2RR) emerges as a promising route to simultaneously attain harmful NO2- removal and green NH3 synthesis. In this study, amorphous CoS2 nanorods (a-CoS2) are first demonstrated as an effective NO2RR catalyst, which exhibits the maximum FENH3 of 88.7% and NH3 yield rate of 438.1 µmol h-1 cm-2 at -0.6 V vs RHE. Detailed experimental and computational investigations reveal that the high NO2RR performance of a-CoS2 originates from the amorphization-induced S vacancies to facilitate NO2- activation and hydrogenation, boost the electron transport kinetics, and inhibit the competitive hydrogen evolution.

Tuning microscopic structure of La-MOFs via ligand engineering effect towards enhancing phosphate adsorption.

The selection of different organic ligands when synthesizing metal organic framework (MOFs) can change their effects on the adsorption performance. Here, four La-MOFs adsorbents (La-SA, La-FA, La-TA and La-OA) with different organic ligands and structures were synthesized by solvothermal method for phosphate adsorption, and the relationship between their adsorption properties and structures was established. Among four La-MOFs, their phosphate adsorption capacities and adsorption rates followed La-SA > La-FA > La-TA > La-OA. The results indicated that average pore diameter played a key role in phosphate adsorption and there was a positive correlation between average pore diameter and adsorption capacity (R2 = 0.86). Coexisting ion experiments showed that phosphate adsorptions on three La-MOFs (La-SA, La-FA and La-TA) were inhibited in the presence of CO32- and HCO3-. The inhibition of CO32- was the most pronounced and the results of redundancy analysis pointed out that it was mainly due to the change of pH value. In contrast, La-OA showed enhanced phosphate adsorption in the presence of CO32- and HCO3-, and the combination of pH experiments showed that phosphate adsorption by La-OA was increased under alkaline conditions. Further combined with FT-IR, XRD, high resolution energy spectra of XPS (La 3d, P 2p and O 1s) and XANES, the adsorption mechanisms were derived electrostatic attraction, chemical precipitation and inner sphere complexation, and the last two were identified as the main mechanisms. Moreover, it can be identified from XPS 2p that the phosphate adsorption on La-FA and La-OA were mainly in the LaPO4 state, while La-SA and La-TA mainly existed in the form of LaPO4·xH2O crystals and inner sphere complexes. From the perspective of material morphology, this work provides a thought for the rational design of MOFs with adjustable properties for phosphate adsorption.

A Rapid and Accurate UHPLC Method for Determination of Monosaccharides in Polysaccharides of Different Sources of Radix Astragali and Its Immune Activity Analysis.

With the escalating demand for Astragalus polysaccharides products developed from Radix Astragali (RA), the necessity for quality control of polysaccharides in RA has become increasingly urgent. In this study, a specific method for the simultaneous determination of seven monosaccharides in polysaccharides extracted from Radix Astragali (RA) has been developed and validated using ultra-performance liquid chromatography equipped with an ultraviolet detector (UHPLC-UV) for the first time. The 1-phenyl-3-methyl-5-pyrazolone (PMP) derivatizations were separated on a C18 column (Waters ACQUITYTM, Milfor, MA, USA, 1.8 µm, 2.1 × 100 mm) using gradient elution with a binary system of 5 mm ammonium formate (0.1% formic acid)-acetonitrile for 24 min. Additionally, seven monosaccharides showed good linear relationships (R2, 0.9971-0.9995), adequate precision (RSD < 4.21%), and high recoveries (RSD < 4.70%). The established method was used to analyze 109 batches of RA. Results showed that the Astragalus polysaccharides (APSs) mainly consist of mannose (Man), rhamnose (Rha), glucose (Glu), galactose (Gal), arabinose (Ara), xylose (Xyl); and fucose (Fuc); however, their composition was different among RA samples from different growth patterns, species, growth years, and origins, and the growth mode of RA and the age of wild-simulated RA can be accurately distinguished by principal component analysis (PCA). In addition, the immunological activity of APSs were also evaluated jointly by measurement of the NO release with RAW264.7, with the results showing that APSs have a promoting effect on the release of NO and exhibit a significant correlation with Man, Glu, Xyl, and Fuc contents. Accordingly, the new established monosaccharides analytical method and APS-immune activity determination in this study can provide a reference for quality evaluation and the establishment of quality standards for RA.

Vanadium Diboride (VB2) for NO Electroreduction to NH3.

We report VB2 as an efficient electrocatalyst for NO-to-NH3 electroreduction (NORR), showing the highest NH3-Faradaic efficiency of 89.6% with the corresponding NH3 yield rate of 198.3 µmol h-1 cm-2 at -0.5 V vs RHE. Theoretical calculations demonstrate that B sites of VB2 act as the key active centers which can facilitate the NORR protonation energetics and inhibit the competitive hydrogen evolution, boosting both NORR activity and selectivity.

PdP2 Nanoparticles on Reduced Graphene Oxide: A Catalyst for the Electrocatalytic Reduction of Nitrate to Ammonia.

Palladium phosphides are explored as efficient catalysts for the electrocatalytic reduction of nitrate to ammonia (NRA). The explored PdP2 nanoparticles on reduced graphene oxide exhibit the maximum NH3 Faradaic efficiency of 98.2% with a corresponding NH3 yield rate of 7.6 mg h-1 cm-2 at -0.6 V (RHE). Theoretical calculations reveal that a PdP2 (011) surface can not only effectively activate and hydrogenate NO3- via a NOH pathway but also retard H adsorption to inhibit the competitive hydrogen evolution reaction.

Iron Diboride (FeB2) for the Electroreduction of NO to NH3.

We report iron diboride (FeB2) as a high-performance metal diboride catalyst for electrochemical NO-to-NH3 reduction (NORR), which shows a maximum NH3 yield rate of 289.3 µmol h-1 cm-2 and a NH3-Faradaic efficiency of 93.8% at -0.4 V versus reversible hydrogen electrode. Theoretical computations reveal that Fe and B sites synergetically activate the NO molecule, while the protonation of NO is energetically more favorable on B sites. Meanwhile, both Fe and B sites preferentially absorb NO over H atoms to suppress the competing hydrogen evolution.

Life cycle assessment of greenhouse gas emissions of typical sewage sludge incineration treatment route based on two case studies in China.

The rapidly increasing amount of municipal sewage sludge generated in China necessitates a thorough examination and evaluation of available treatment options. In recent years, thermal-drying and incineration technology has gained popularity, however, it may lead to significant greenhouse gas (GHG) emissions. Nevertheless, the differences in boundary conditions and technological characteristic across various cases may affect emission levels significantly. Therefore, this study utilizes a life cycle assessment to estimate the GHG emissions associated with two typical sludge incineration routes in China: direct thermal-drying combined with coal co-incineration incinerator in Case 1 and indirect thermal-drying and self-sustain combustion in Case 2. The entire treatment processes, containing different functional units, were comprehensively investigated. The results demonstrate that Case 1 and Case 2 produce 1133.33 and 350.89 kg CO2-eq/tDS (sludge dry solid) of GHG emissions, respectively. In Case 1, coal co-incineration produces 828.63 kg CO2-eq/tDS of GHG emissions, accounting for 73.1% of the total GHG emissions. Moreover, the exhaust gas treatment is a significant GHG emission source, accounting for 9.2% and 16.9% of the total GHG emissions in Case 1 and Case 2, respectively. Additionally, the sludge thickening and dewatering unit in Case 2 produces 213.75 kg CO2-eq/tDS of GHG emissions, accounting for 60.9% of the total GHG emissions. Analysis of energy flow and heat balance characteristics indicate that the indirect heat transfer method used in thermal-drying leads to significant heat loss, which limits heat recovery potential and hinders GHG emission reduction. This study proposed a scenario case based on Case 2, addressing the issues with the improvement of heat transfer process and reduction of electricity consumption, potentially reducing GHG emissions by 8.8%. Additionally, applying an exhaust gas heat recovery system could further offset up to 22.8% of the total GHG emission.

Dynamic characteristics of net anthropogenic phosphorus input to the upper Yangtze River Basin from 1989 to 2019: Focus on the phosphate ore rich area in China.

Phosphorus (P), a non-renewable essential resource, faces heavy exploitation and contributes to eutrophication in aquatic environments. Assessing P input is vital for a healthier P cycle in the Upper Yangtze River (UYR), a phosphate ore rich basin, where P mining and P chemical enterprises have prominent pollution problems. This study modified the net anthropogenic phosphorus input (NAPI) model to include ore mining P input (Pore). We analyzed the evolutionary characteristics of P input in five sub-basins of UYR from 1989 to 2019 using prefecture-level data, and assessed the uncertainty of the data. NAPI in all sub-basins exhibited an upward and then downward trend during 1989-2019, with the inflection point occurring in 2015 or 2016, showing a net increase of about 1.1 times (568-1162 kg P km-2 yr-1) in the whole UYR basin. Among the components of NAPI, P fertilizer inputs (Pfer) and food/non-food and feed P inputs (Pf/nf&feed) contributed comparably, though the growth rate of Pfer was most notable basin-wide. Pore proportion increased significantly (about 3-fold), with a peak of 20%, especially in Wujiang sub-basin. The multi-year (1989-2019) average NAPI in UYR rose sequentially from west to east, with hotspot areas mainly concentrated in the Sichuan-Chongqing urban agglomeration and cities of Hubei province. The regional P input closely related to the population density and the level of agricultural development, certainly the phosphate mining was also unignorable. This study emphasizes that based on current status of NAPI development in UYR, targeted management for different regions should focus on improving agricultural P use efficiency and rational exploitation of P mineral resources.

Bioremediation system consisted with Leclercia adecarboxylata and nZVI@Carbon/Phosphate for lead immobilization: The passivation mechanisms of chemical reaction and biological metabolism in soil.

Bioremediation is one of the most promising strategies for heavy metal immobilization. A new remediation system was demonstrated in this research, which combined phosphate solubilizing bacteria (PSB) with nZVI@Carbon/Phosphate (nZVI@C/P) composite to remediate lead contaminated soil. Experimental results indicated that the new system (nZVI@C/P + PSB) could effectively convert the labile Pb into the stable fraction after 30 days of incubation, which increased the maximum residual fraction percentage of Pb by 70.58%. The characterization results showed that lead may exist in the forms of Pb5(PO4)3Cl, PbSO4 and 3PbCO3·2Pb(OH)2·H2O in the soil treated with nZVI@C/P + PSB. Meanwhile, soil enzyme activities and Leclercia abundance were enhanced in the treated soil compared with CK during the incubation time. In addition, the specialized functions (e.g. ABC transporters, siderophore metabolism, sulfur metabolism and phosphorus metabolism) in PSB and nZVI@C/P + PSB group were also enhanced. These phenomena proved that the key soil metabolic functions may be maintained and enhanced through the synergistic effect of incubated PSB and nZVI@C/P. The study demonstrated that this new bioremediation system provided feasible way to improve the efficacy for lead contaminated soil remediation.

Discrimination of Radix Astragali from Different Growth Patterns, Origins, Species, and Growth Years by an H1-NMR Spectrogram of Polysaccharide Analysis Combined with Chemical Pattern Recognition and Determination of Its Polysaccharide Content and Immunological Activity.

The fraud phenomenon is currently widespread in the traditional Chinese medicine Radix Astragali (RA) market, especially where high-quality RA is substituted with low-quality RA. In this case, focused on polysaccharides from RA, the classification models were established for discrimination of RA from different growth patterns, origins, species, and growth years. 1H Nuclear Magnetic Resonance (H1-NMR) was used to establish the spectroscopy of polysaccharides from RA, which were used to distinguish RA via chemical pattern recognition methods. Specifically, orthogonal partial least squares discriminant analysis (OPLS-DA) and linear discriminant analysis (LDA) were used to successfully establish the classification models for RA from different growth patterns, origins, species, and growth years. The satisfactory parameters and high accuracy of internal and external verification of each model exhibited the reliable and good prediction ability of the developed models. In addition, the polysaccharide content and immunological activity were also tested, which was evaluated by the phagocytic activity of RAW 264.7. And the result showed that growth patterns and origins significantly affected the quality of RA. However, there was no significant difference in the aspects of origins and growth years. Accordingly, the developed strategy combined with chemical information, biological activity, and multivariate statistical method can provide new insight for the quality evaluation of traditional Chinese medicine.

Effect of nitrite on hydrolysis-acidification, biogas production and microbial community in semi-continuous two-phase anaerobic digestion of sewage sludge.

Previous study found that the pre-treatment of sewage sludge with nitrite improves the biogas production during the mono/two-phase anaerobic digestion (AD) using batch biochemical methane potential tests. In this study, the effects of nitrite on hydrolysis-acidification, biogas production, volatile solids destruction and microbial composition in semi-continuous two-phase AD of sewage sludge were investigated. The addition of nitrite promotes sludge organic matter solubilization (+484%) and VFAs production (+98.9%), and causes an increase in the VS degradation rate during the AD process (+8.7%). The comparison of biogas production from the acidogenic and methanogenic reactors with or without the addition of nitrite implies that the nitrite has no significant effect on the overall biogas production of two-phase sludge AD process. High-throughput sequencing analysis shows that the microbial communities of bacteria and archaea in two-phase AD reactors significantly changes after the addition of nitrite. Vulcanibacillus (bacteria) and Candidatus Methanofastidiosum (archaea) become the dominant genera in the acidogenic and methanogenic reactors with the nitrite respectively. These findings provide new insights about using nitrite to promote the organic matter degradation of sewage sludge in a semi-continuous two-phase AD system.

Insights into multisource sludge distributed in the Yangtze River basin, China: Characteristics, correlation, treatment and disposal.

Sludge is the by-product of wastewater treatment process. Multisource sludge can be defined as sludge from different sources. Based on the sludge properties of five typical cities in the Yangtze River basin, including Jiujiang, Wuhu, Lu'an, Zhenjiang and Wuhan, this study investigated and summarized the characteristic variations and distribution differences of multiple indicators and substances from municipal sludge, dredged sludge, and river and lake sediments. The results demonstrated pH of multisource sludge was relatively stable in the neutral range. Organic matter and water content among municipal sludge were high and varied considerably between different wastewater treatment plants. Dredged sludge had an obviously higher sand content and wider particle distribution, which could be considered for graded utilization depending on its size. The nutrients composition of river and lake sediments was usually stable and special, with lower nitrogen and phosphorus content but higher potassium levels. The sources of heavy metals and persistent organic pollutants in multisource sludge were correlated, generally much higher among municipal sludge than dredged sludge and river and lake sediments, which were the most important limitation for final land utilization. Despite various properties of multisource sludge, the final fate and destination have some overall similarities, which need to be supplemented and improved by standards and laws. The study provided a preliminary analysis of suitable technical routes for municipal sludge, dredged sludge, river and lake sediments based on their different characteristics respectively, which was of great significance for multisource sludge co-treatment and disposal in the future of China.

Tandem Electrocatalytic Nitrate Reduction to Ammonia on MBenes.

We demonstrate the great feasibility of MBenes as a new class of tandem catalysts for electrocatalytic nitrate reduction to ammonia (NO3 RR). As a proof of concept, FeB2 is first employed as a model MBene catalyst for the NO3 RR, showing a maximum NH3 -Faradaic efficiency of 96.8 % with a corresponding NH3 yield of 25.5 mg h-1 cm-2 at -0.6 V vs. RHE. Mechanistic studies reveal that the exceptional NO3 RR activity of FeB2 arises from the tandem catalysis mechanism, that is, B sites activate NO3 - to form intermediates, while Fe sites dissociate H2 O and increase *H supply on B sites to promote the intermediate hydrogenation and enhance the NO3 - -to-NH3 conversion.

Association of SLC22A1 rs622342 and ATM rs11212617 polymorphisms with metformin efficacy in patients with type 2 diabetes.

Metformin is the first-choice oral anti-hyperglycemic drug for type 2 diabetes mellitus (T2DM) patients. There are controversies about the association of SLC22A1 rs622342, which was not reported in the Chinese population, and ataxia-telangiectasia mutated (ATM) rs11212617 polymorphisms with metformin efficacy in T2DM. Our study was to investigate the effects of the two single nucleotide polymorphisms on the efficacy of metformin in T2DM of Han nationality in Chaoshan China. After enrollment, 82 newly diagnosed T2DM patients went on 2-month metformin monotherapy. According to BMI before treatment, the patients were divided into a normal weight group (≥18.5 and <25 kg/m2) and an overweight group (BMI ≥ 25 and <30 kg/m2). T-test, Pearson χ2 test, and regression analysis, which adjusted for age, BMI, sex, the dose of metformin, education, tea drink, smoking, and sweet, were used to evaluate the effects of rs622342 and rs11212617 on several variables, such as fasting plasma glucose (FPG). Compared with the AA or CC genotype, patients with AC genotype of rs622342 achieved greater reduction in Δ60FPG and Δ(60-30)FPG (P = 0.00820, 0.00089, respectively). For 11212617, the reduction in Δ30FPG and Δ60FPG was significantly different among patients with the AC genotype (P = 0.00026, 0.00820, respectively). Our results indicated that common variants of SLC22A1 rs622342 and ATM rs11212617 were associated with the efficacy of metformin in T2DM of Han nationality in Chaoshan China.

SRSF1 promotes ASMC proliferation in asthma by competitively binding CCND2 with miRNA-135a.

BACKGROUND: Asthma is an inflammatory syndrome characterized by airway hyperresponsiveness, bronchial inflammation, and airway remodeling. Abnormal proliferation of airway smooth muscle cells (ASMCs) is the main pathological feature of asthma. This study investigated the function and mechanism of serine arginine-rich splicing factor 1 (SRSF1) in ASMC proliferation in asthma. METHODS: SRSF1 expressions in the bronchi of ovalbumin-induced asthmatic mice and IgE-treated mouse ASMCs (mASMCs) were evaluated using quantitative real-time PCR and Western blot. The localization and expression of SRSF1 in the bronchi of asthmatic mice were assessed by immunohistochemistry. Functionally, gain- and loss-of-function assays, flow cytometry, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assays were conducted. Mechanistically, RNA degradation assay, RNA immunoprecipitation, RNA pull-down, and dual-luciferase reporter gene assays were carried out. RESULTS: SRSF1 was highly expressed in the bronchi of ovalbumin-induced asthma mice and IgE-treated mASMCs and was mainly located in the nucleus. Experiments on the function of SRSF1 showed that the silencing of SRSF1 induced the cell cycle of mASMC arrest and restrained mASMC proliferation. Investigations into the mechanism of SRSF1 revealed that SRSF1 and miR-135a are competitively bound to the 3'UTR region of Cyclin D2 (CCND2). SRSF1 overexpression repressed the degradation of CCND2 mRNA, and miR-135a negatively regulated CCND2 expression. Furthermore, SRSF1 knockdown inhibited ASMC proliferation in asthma mouse models by regulating the levels of miR-135a and CCND2. CONCLUSION: SRSF1 knockdown repressed ASMC proliferation in asthma by regulating miR-135a/CCND2 levels.

Ectopic Expression of JcCPL1, 2, and 4 Affects Epidermal Cell Differentiation, Anthocyanin Biosynthesis and Leaf Senescence in Arabidopsis thaliana.

The CAPRICE (CPC)-like (CPL) genes belong to a single-repeat R3 MYB family, whose roles in physic nut (Jatropha curcas L.), an important energy plant, remain unclear. In this study, we identified a total of six CPL genes (JcCPL1-6) in physic nut. The JcCPL3, 4, and 6 proteins were localized mainly in the nucleus, while proteins JcCPL1, 2, and 5 were localized in both the nucleus and the cytoplasm. Ectopic overexpression of JcCPL1, 2, and 4 in Arabidopsis thaliana resulted in an increase in root hair number and decrease in trichome number. Consistent with the phenotype of reduced anthocyanin in shoots, the expression levels of anthocyanin biosynthesis genes were down-regulated in the shoots of these three transgenic A. thaliana lines. Moreover, we observed that OeJcCPL1, 2, 4 plants attained earlier leaf senescence, especially at the late developmental stage. Consistent with this, the expression levels of several senescence-associated and photosynthesis-related genes were, respectively, up-regulated and down-regulated in leaves. Taken together, our results indicate functional divergence of the six CPL proteins in physic nut. These findings also provide insight into the underlying roles of CPL transcription factors in leaf senescence.

PdFe Single-Atom Alloy Metallene for N2 Electroreduction.

Single-atom alloys hold great promise for electrocatalytic nitrogen reduction reaction (NRR), while the comprehensive experimental/theoretical investigations of SAAs for the NRR are still missing. Herein, PdFe1 single-atom alloy metallene, in which the Fe single atoms are confined on a Pd metallene support, is first developed as an effective and robust NRR electrocatalyst, delivering exceptional NRR performance with an NH3 yield of 111.9 µg h-1 mg-1 , a Faradaic efficiency of 37.8 % at -0.2 V (RHE), as well as a long-term stability for 100 h electrolysis. In-depth mechanistic investigations by theoretical computations and operando X-ray absorption/Raman spectroscopy indentify Pd-coordinated Fe single atoms as active centers to enable efficient N2 activation via N2 -to-Fe σ-donation, reduced protonation energy barriers, suppressed hydrogen evolution and excellent thermodynamic stability, thus accounting for the high activity, selectivity and stability of PdFe1 for the NRR.