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The electrosynthesis of pure urea via the co-reduction of CO 2 and N 2 remains challenging. Here we show that a proton-limited environment established in an electrolyser equipped with porous solid-state electrolyte, devoid of an aqueous electrolyte, can suppress the hydrogen evolution reaction and excessive hydrogenation of N 2 to ammonia. This can instead be conducive to the C–N coupling of *CO 2 with *NHNH (the intermediate from the semi-hydrogenation of N 2 ), thereby facilitating the production of urea. By using nanosheets of an ultrathin two-dimensional metal–azolate framework with cyclic heterotrimetal clusters as catalyst, the Faradaic efficiency of urea production from pretreated flue gas (which contains mainly 85% N 2 and 15% CO 2 ) is as high as 65.5%, and no ammonia and other liquid products were generated. At a low cell voltage of 2.0 V, the current can reach 100 mA, and the urea production rate is as high as 5.07 g g cat −1  h −1 or 84.4 mmol g cat −1  h −1 . Notably, it can continuously produce 6.2 wt% pure urea aqueous solution for at least 30 h, and about 1.24 g pure urea solid was obtained. The use of pretreated flue gas as a direct feedstock significantly reduces input costs, and the high reaction rate and selectivity contribute to a reduction in system scale and operational costs. This study reveals that the synergistic effect of proton-limited environments and multi-site cooperative activation coupling substantially improves the electrocatalytic co-reduction of CO 2 and N 2 towards urea production, enabling gram-scale synthesis.

Clear elucidation of the connection between chemical structure and biological action mechanisms is the key issue preventing the successful development of nanomedicines. Herein, employing essential trace element selenium (Se) as an example, we fabricate organic-inorganic covalent Se hybrid by anchoring Se atom to polyethylene glycol chain during carbonization to form organic Se-C and inorganic Se-Se bonds in one system to integrate the advantages of both species. The weak covalent Se-Se bond breaks down in response to redox stimuli, thus releases organic Se with stronger electron transfer ability to scavenge free radicals, and forms highly active inorganic Se, which further releases free Se atom to trigger selenoprotein synthesis and activation, ultimately reverses reperfusion injury in male-mice ischemic stroke, and improves neurological restoration. This work provides a unique Se atom reprogramming strategy to design highly bioactive hybrid Se species with clear chemical nature and action mechanisms. Developing potent and biocompatible antioxidative nanomedicines is beneficial for reversing ischemic reperfusion injury, but hindered by a lack of understanding of biological action mechanisms. Here, the authors report bioactive organic-inorganic covalent selenium hybrid nanoparticles, and elucidate their mechanisms of action in suppressing reperfusion-induced injury of ischemic stroke.

The α-C-C cleavage coupling of ketones offers a highly challenging yet promising approach for C–C bond formation, particularly given the ubiquity and ready accessibility of ketones as fundamental synthons in organic synthesis. However, the deacylative cross-coupling between two distinct ketones via a single activation mode remains an unmet challenge, although this coupling paradigm could be leveraged to construct C(sp 3 )–C(sp 3 ) linkages with exceptional structural diversity. Herein, we describe a cross-ketone deacylative coupling via nickel-catalyzed bimolecular homolytic substitution (S H 2), in which the synergistic oxidative photocatalysis is combined to produce simultaneously two distinct open-shell carbons from ketone-derived dihydroquinazolinones. This hetero-selective radical-radical coupling protocol enables the construction of quaternary carbon centers through a critical S H 2 displacement mechanism, providing an efficient approach to furnish β-quaternary aliphatic amines. Additionally, a wide array of biorelevant small molecules, including β-amino alcohol, β-diamine and β-aminothiol derivatives, can also be obtained via this cross-double deacylative C 1 -alkylation approach between distinct ketones. The α-C–C cleavage of ketones provides a versatile route for C–C bond formation but remains challenging, particularly for selective cross-coupling between distinct ketones. Here the authors report a nickel- and photocatalysis-enabled deacylative coupling via bimolecular homolytic substitution to forge diverse C(sp³)–C(sp³) bonds.

The synthesis of urea by the electrochemical co-reduction of CO 2 and nitrate is a crucial and challenging task. Catalysts typically suffer from either low Faradaic efficiency (FE) or inadequate current density, leading to a restricted yield rate of urea. Here we report ultrasmall γ-Fe 2 O 3 nanoparticles (<2 nm) encapsulated in the pores of a conductive (40 S cm −1 ) metal–organic framework Ni-HITP (HITP = 2,3,6,7,10,11-hexaaminotriphenylene), resulting in a composite material, γ-Fe 2 O 3 @Ni-HITP. Under neutral conditions, γ-Fe 2 O 3 @Ni-HITP exhibited a state-of-art electrocatalytic performance for urea synthesis through the co-reduction of CO 2 and nitrate in CO 2 -saturated 1 M KHCO 3 and 0.1 M KNO 3 aqueous solutions, achieving a FE urea of 67.2(6)%, a current density of −90 mA cm −2 and an high yield rate of 20.4 ( 2 ) g h − 1 g cat − 1 (7.7(1) mg h −1  cm −2 ), which is about five times higher than the rates of previously reported catalysts. No degradation was observed over 150 h of continuous operation at such a high yield rate. Enlarging the electrode area by 125 times yielded about 1.05(4) g of high-purity urea over 8 h. A mechanistic study revealed that Fe(III) ions in the γ-Fe 2 O 3 nanoparticles exhibit high activity, generating the key intermediates *NH 2 and *COOH. Furthermore, pairs of adjacent Fe(III) ions in the γ-Fe 2 O 3 nanoparticles can act as highly active catalytic sites for catalysing the C–N coupling between *NH 2 and *COOH, resulting in the formation of the subsequent key intermediate *CONH 2 , thereby contributing to the exceptionally high performance of γ-Fe 2 O 3 @Ni-HITP for urea production. Small γ-Fe 2 O 3 nanoparticles (<2 nm) encapsulated in the pores of a conductive metal–organic framework enable the efficient electrosynthesis of urea through the co-reduction of CO 2 and nitrate under neutral conditions.

Juvenile hormone (JH) is a key regulator of larval development in honeybees. Its biosynthesis involves multiple enzymatic steps and is modulated by a complex regulatory network that includes microRNAs (miRNAs). Juvenile hormone acid methyltransferase (JHAMT) catalyzes the final step in JH synthesis. This study demonstrates that the miRNA novel-m0027-3p negatively regulates the expression of the Jhamt gene in Apis mellifera larvae (AmJhamt), thereby mediating JH biosynthesis. Bioinformatics predictions indicate that novel-m0027-3p potentially targets six hormone-related genes (22 mRNAs), including AmJhamt. Dual-luciferase reporter assays and mimics/inhibitor-miRNA feeding confirmed that novel-m0027-3p significantly suppresses the expression of the target gene AmJhamt. In vivo experiments showed that larvae fed with the mimics of novel-m0027-3p exhibited decreased JH titers and significantly downregulated expression of JH signaling downstream genes AmHex70b and AmKr-h1. Conversely, larvae fed with the inhibitors of novel-m0027-3p displayed significantly elevated JH titers and markedly upregulated expression of AmHex70b and AmKr-h1. Our findings provide experimental evidence for the coupling between miRNAs and hormonal pathways in honeybees.

Two-dimensional metal-organic frameworks (2D MOFs), as a new type of 2D materials, have been widely applied in various applications because of their unique structures and exposed active sites. Herein, we reported two low-cost 2D MOFs constructed by a raw chemical succinic acid (SA), M-SA (M = Ni or Co), which served as efficient photocatalysts for the reduction of CO 2 to CO. Taking advantage of the thinness and open metal sites, the ultrathin Ni-SA nanosheets (ca. 3.6 nm) exhibited excellent CO production of 6.96(7) mmol·g −1 h −1 and CO selectivity of 96.6%. Photoelectrochemical tests and theoretical calculations further confirmed the higher charge transfer efficiency and unsaturated metal sites for promoting photocatalytic performances. More importantly, Ni-SA can also be synthesized in large-scale by an energy-saving method under room temperature, strongly suggesting its promising future and potential for practical applications.

Striped stem borer (SSB; Chilo suppressalis Walker) is one of the most destructive pests in rice production. Previous studies have demonstrated that SSB infestation induces transcription of OsT5H (tryptamine‐5‐hydroxylase) and biosynthesis of serotonin, a newly recognised phytohormone, and that disruption of serotonin biosynthesis significantly increases SSB resistance. However, the regulatory module modulating serotonin biosynthesis remains to be identified and characterised. Here, we reveal an OsMYB306‐OsRAV11 module that regulates OsT5H transcription and serotonin biosynthesis in response to SSB infestation in rice. OsMYB306 and OsRAV11 can bind to the OsT5H promoter and repress its transcription. In the module, OsRAV11 interacts with OsMYB306 and enhances its inhibitory effect on OsT5H transcription. CRISPR/Cas9‐generated knockout mutants (myb306, rav11 and myb306 rav11) exhibited elevated OsT5H expression, increased serotonin accumulation and reduced SSB resistance. Conversely, OsRAV11 overexpression reduced OsT5H transcription. Our findings establish a transcriptional regulatory framework for the biosynthesis of serotonin in response to SSB infestation. These findings inform the development of new strategies for producing SSB‐resistant rice by genome editing, potentially reducing reliance on chemical pesticides for SSB control.

Solar photovoltaic (PV) plays a crucial role in China’s pursuit of carbon neutrality. Assessing the PV power potential over China is essential for future energy planning and policy making. Surface solar radiation and panel tilt angle are critical factors influencing PV power generation. However, existing solar radiation datasets cannot fully meet assessment needs due to insufficient temporal coverage and limited accuracy, and the impact of panel tilt angles on PV potential is largely overlooked. This study developed a PV power estimation framework to assess the long-term (1980–2019) PV power potential at 609 stations across China, based on reconstructed high-quality solar radiation and optimized tilt angles. The validation of PV power estimates using ground measured outputs from four operational PV power stations indicated a correlation coefficient of 0.67 and a root mean square error of 0.07 for estimated daily capacity factor (CF). The assessment results revealed that the multi-year mean CF of China is 0.149 ± 0.031, with higher potentials in northern provinces and lower in southern provinces. The mean annual CF shows a declining trend of −7 × 10−4 per decade during 1980–2019, with significant decreases primarily in heavily polluted regions. In addition, we propose an optimal tilt angle estimation model based on diffuse fraction, achieving higher accuracy than previously released models. The estimated optimal tilt angle results in an increase in PV energy yield by 14.9 TWh/year for China compared with latitude-based schemes, based on China’s cumulative PV capacity by 2023 (609 GW). Our findings provide valuable insights for the effective implementation of solar PV projects in China.

Natural polymeric proteins, isolated from scallop gonad, had already shown promise as a potent nutraceutical. The purpose of this study was to fabricate scallop gonad protein isolates (SGPIs) as a natural alternative emulsifier designed for improving the physicochemical stability of β-carotene (BC). The influence of carrier oil, including long- and medium-chain triglycerides (LCT/MCT), on the physicochemical stability of BC emulsions was investigated. The SGPI-stabilized BC emulsions were characterized in terms of viscosity, particle diameter, zeta-potential, atomic force microscopy (AFM), cryogenic scanning electron microscopy (cryo-SEM), and confocal laser scanning microscopy (CLSM). Compared to SGPI-MCT emulsions, SGPI-LCT emulsions had better resistance to high ionic strengths and thermal treatment. During the 30-day storage period, the particle diameter, zeta-potential, and BC degradation of both emulsions had a great change at 37 °C than at 25 or 4 °C, and the variation of SGPI-MCT emulsions was more obvious than that of SGPI-LCT, which could be attributed to the high viscosity of SGPI-LCT emulsions. These results indicate that SGPIs can be applied in protecting lipophilic bioactives by using emulsion-based systems, in which LCT oil was more effective for encapsulating and protecting BC than MCT oil. Graphical abstract

Acne is a serious disfiguring follicular sebaceous gland disorder that negatively affects patients' quality of life and self-image. Chloramphenicol (CAM) is effective against Propionibacterium acnes and Staphylococcus aureus which cause acne, often used as a hospital preparation for acne treatment. However, because of its toxicity and poor water solubility, its use has been restricted. To overcome these limitations, the study focused on developing CAM-loaded binary ethosomes (CAM-BE) and incorporating them into a hydrogel system for transdermal delivery. CAM-BE were prepared and characterized. Following incorporation of the selected formulation into the hydrogel, the formulation's skin-interaction was evaluated using attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy and confocal laser scanning microscopy (CLSM). Furthermore, a rat ear acne model was used to evaluate the formulation's in vivo anti-inflammatory efficacy and ex vivo skin permeability. The optimal formulation contained ethanol/propylene glycol ratios of 3:7 (w/w), exhibited particle size was 97.68 ± 4.9 nm, zeta-potential was -23.5 ± 1.3 mV, and encapsulation efficiency was 60.36 ± 2.12%. The BE hydrogel that was created showed persistent drug release. Additionally, it demonstrated an enhanced flow of 4.374 ± 0.12 μg/cm /hour, permeability coefficient was 3.65 ± 0.09 cm/h×10 , and apparent skin deposition was 17.77 ± 1.13 μg/cm . CLSM and ATR-FTIR confirm that loading CAM into a binary ethosomes enables drugs to pass more easily through the stratum corneum. In vivo testing and histopathological analysis demonstrated that the CAM-BE hydrogel significantly inhibited swelling in the rat auricle, compared to both the free CAM hydrogel and adapalene hydrogel. With their strong anti-inflammatory properties and improved skin penetration, binary ethosomes could be a viable new CAM delivery method. The new formulation was therefore seen as quite promising.