Recent Progress on the Involvement of Formaldehyde in the Methanol-to-Hydrocarbons Reaction.

The conversion of methanol-to-hydrocarbons (MTH) over zeolite catalysts has been the subject of intense research since its discovery. Great effort has been devoted to the investigation of four key topics: the initiation of C-C bonds, the establishment of hydrocarbon pool (HCP), the adjustment of product selectivity, and the deactivation process of catalysts. Despite 50 years of study, some mechanisms remain controversial. However, an intermediate species, formaldehyde (HCHO), has recently garnered considerable attention for its influence on the entire MTH process. The discovery of HCHO and its significant role in the MTH process has been facilitated by the application of in situ analytical techniques, such as synchrotron radiation photoionization mass spectrometry (SR-PIMS) and photoelectron photoion coincidence spectroscopy (PEPICO). It is now revealed that HCHO is involved in the initiation, propagation, and termination process of MTH reaction. Such mechanistic understanding of HCHO's involvement has provided valuable insights for optimizing the MTH process.

Unmasking Spatial Heterogeneity in Phytotoxicology Mechanisms Induced by Carbamazepine by Mass Spectrometry Imaging and Multiomics Analyses.

Previous studies have highlighted the toxicity of pharmaceuticals and personal care products (PPCPs) in plants, yet understanding their spatial distribution within plant tissues and specific toxic effects remains limited. This study investigates the spatial-specific toxic effects of carbamazepine (CBZ), a prevalent PPCP, in plants. Utilizing desorption electrospray ionization mass spectrometry imaging (DESI-MSI), CBZ and its transformation products were observed predominantly at the leaf edges, with 2.3-fold higher concentrations than inner regions, which was confirmed by LC-MS. Transcriptomic and metabolic analyses revealed significant differences in gene expression and metabolite levels between the inner and outer leaf regions, emphasizing the spatial location's role in CBZ response. Notably, photosynthesis-related genes were markedly downregulated, and photosynthetic efficiency was reduced at leaf edges. Additionally, elevated oxidative stress at leaf edges was indicated by higher antioxidant enzyme activity, cell membrane impairment, and increased free fatty acids. Given the increased oxidative stress at the leaf margins, the study suggests using in situ Raman spectroscopy for early detection of CBZ-induced damage by monitoring reactive oxygen species levels. These findings provide crucial insights into the spatial toxicological mechanisms of CBZ in plants, forming a basis for future spatial toxicology research of PPCPs.

Ooceraeahainingensis sp. nov.: A new Chinese Ooceraea (Hymenoptera, Formicidae, Dorylinae) species with a dealate queen, closely allied to the queenless clonal raider ant O.biroi.

The clonal raider ant, Ooceraeabiroi, is a queenless species that reproduces asexually, and these traits make it an attractive model system for laboratory research. However, it is unclear where on the ant phylogeny these traits evolved, partly because few closely related species have been described and studied. Here, we describe a new raider ant species, Ooceraeahainingensis sp. nov., from Zhejiang, China. This species is closely related to O.biroi but can be distinguished by the following features: 1) workers of O.hainingensis sp. nov. have an obvious promesonotal suture and a metanotal groove, whereas these characters are ambiguous in O.biroi; and 2) the subpetiolar process of O.hainingensis is prominent and anteroventrally directed like a thumb with sublinear posteroventral margin, while in O.biroi, it is anteroventrally directed but slightly backward-bent. Molecular phylogenetic analyses confirm that O.hainingensis is genetically distinct from O.biroi. Importantly, unlike O.biroi, O.hainingensis has a queen caste with wings and well-developed eyes. This suggests that the loss of the queen caste and transition to asexual reproduction by workers is specific to O.biroi and occurred after that species diverged from closely related congeneric species.

High-Rate and Selective C2H6-to-C2H4 Photodehydrogenation Enabled by Partially Oxidized Pdδ+ Species Anchored on ZnO Nanosheets under Mild Conditions.

Photocatalytic C2H6-to-C2H4 conversion is very promising, yet it remains a long-lasting challenge due to the high C-H bond dissociation energy of 420 kJ mol-1. Herein, partially oxidized Pdδ+ species anchored on ZnO nanosheets are designed to weaken the C-H bond by the electron interaction between Pdδ+ species and H atoms, with efforts to achieve high-rate and selective C2H6-to-C2H4 conversion. X-ray photoelectron spectra, Bader charge calculations, and electronic localization function demonstrate the presence of partially oxidized Pdδ+ sites, while quasi-in situ X-ray photoelectron spectra disclose the Pdδ+ sites initially adopt and then donate the photoexcited electrons for C2H6 dehydrogenation. In situ electron paramagnetic resonance spectra, in situ Fourier transform infrared spectra, and trapping agent experiments verify C2H6 initially converts to CH3CH2OH via ·OH radicals, then dehydroxylates to CH3CH2· and finally to C2H4, accompanied by H2 production. Density-functional theory calculations elucidate that loading Pd site can lengthen the C-H bond of C2H6 from 1.10 to 1.12 Å, which favors the C-H bond breakage, affirmed by a lowered energy barrier of 0.04 eV. As a result, the optimized 5.87% Pd-ZnO nanosheets achieve a high C2H4 yield of 16.32 mmol g-1 with a 94.83% selectivity as well as a H2 yield of 14.49 mmol g-1 from C2H6 dehydrogenation in 4 h, outperforming all the previously reported photocatalysts under similar conditions.

Highly efficient, selective, and stable photocatalytic methane coupling to ethane enabled by lattice oxygen looping.

Light-driven oxidative coupling of methane (OCM) for multi-carbon (C2+) product evolution is a promising approach toward the sustainable production of value-added chemicals, yet remains challenging due to its low intrinsic activity. Here, we demonstrate the integration of bismuth oxide (BiOx) and gold (Au) on titanium dioxide (TiO2) substrate to achieve a high conversion rate, product selectivity, and catalytic durability toward photocatalytic OCM through rational catalytic site engineering. Mechanistic investigations reveal that the lattice oxygen in BiOx is effectively activated as the localized oxidant to promote methane dissociation, while Au governs the methyl transfer to avoid undesirable overoxidation and promote carbon─carbon coupling. The optimal Au/BiOx-TiO2 hybrid delivers a conversion rate of 20.8 millimoles per gram per hour with C2+ product selectivity high to 97% in the flow reactor. More specifically, the veritable participation of lattice oxygen during OCM is chemically looped by introduced dioxygen via the Mars-van Krevelen mechanism, endowing superior catalyst stability.

Imaging and quantification of neuropeptides in mouse pituitary tissue by atmospheric pressure matrix-assisted laser desorption/ionization mass spectrometry.

RATIONALE: Atmospheric pressure matrix-assisted laser desorption/ionization (AP-MALDI) mass spectrometry has enabled the untargeted analysis and imaging of neuropeptides and proteins in biological tissues under ambient conditions. Sensitivity in AP-MALDI can be improved by using sample-specific preparation methods. METHODS: A comprehensive and detailed optimization strategy including instrument parameters, matrix spraying and sample tissue washing pretreatment was implemented to enhance the sensitivity and coverage of neuropeptides in mouse pituitary tissues by commercial AP-MALDI mass spectrometry imaging (MSI). RESULTS: The sensitivity of a commercial AP-MALDI system for endogenous neuropeptides in mouse pituitary was enhanced by up to 15.2-fold by shortening the transmission gap from the sample plate to the inlet, attaching copper adhesive tape to an indium tin oxide-coated glass slide, optimizing the matrix spray solvent and using sample tissue washing pretreatment. Following careful optimization, the distributions of nine endogenous neuropeptides were successfully visualized in the pituitary. Furthermore, the quantitative capability of AP-MALDI for neuropeptides was evaluated and the concentrations of neuropeptides oxytocin and vasopressin in the pituitary posterior lobe were increased approximately twofold under hypertonic saline stress. CONCLUSION: Mouse pituitary neuropeptides have emerged as important signaling molecules due to their role in stress response. This work indicates the potential of modified AP-MALDI as a promising AP MSI method for in situ visualization and quantification of neuropeptides in complex biological tissues.

Microbiome signatures associated with clinical stages of gastric Cancer: whole metagenome shotgun sequencing study.

BACKGROUND: Gastric cancer is one of the global health concerns. A series of studies on the stomach have confirmed the role of the microbiome in shaping gastrointestinal diseases. Delineation of microbiome signatures to distinguish chronic gastritis from gastric cancer will provide a non-invasive preventative and treatment strategy. In this study, we performed whole metagenome shotgun sequencing of fecal samples to enhance the detection of rare bacterial species and increase genome sequence coverage. Additionally, we employed multiple bioinformatics approaches to investigate the potential targets of the microbiome as an indicator of differentiating gastric cancer from chronic gastritis. RESULTS: A total of 65 patients were enrolled, comprising 33 individuals with chronic gastritis and 32 with gastric cancer. Within each group, the chronic gastritis group was sub-grouped into intestinal metaplasia (n = 15) and non-intestinal metaplasia (n = 18); the gastric cancer group, early stage (stages 1 and 2, n = 13) and late stage (stages 3 and 4, n = 19) cancer. No significant differences in alpha and beta diversities were detected among the patient groups. However, in a two-group univariate comparison, higher Fusobacteria abundance was identified in phylum; Fusobacteria presented higher abundance in gastric cancer (LDA scored 4.27, q = 0.041 in LEfSe). Age and sex-adjusted MaAsLin and Random Forest variable of importance (VIMP) analysis in species provided meaningful features; Bacteria_caccae was the most contributing species toward gastric cancer and late-stage cancer (beta:2.43, se:0.891, p:0.008, VIMP score:2.543). In contrast, Bifidobacterium_longum significantly contributed to chronic gastritis (beta:-1.8, se:0.699, p:0.009, VIMP score:1.988). Age, sex, and BMI-adjusted MasAsLin on metabolic pathway analysis showed that GLCMANNANAUT-PWY degradation was higher in gastric cancer and one of the contributing species was Fusobacterium_varium. CONCLUSION: Microbiomes belonging to the pathogenic phylum Fusobacteria and species Bacteroides_caccae and Streptococcus_anginosus can be significant targets for monitoring the progression of gastric cancer. Whereas Bifidobacterium_longum and Lachnospiraceae_bacterium_5_1_63FAA might be protection biomarkers against gastric cancer.

Breaking the Activity-Selectivity Trade-off for CH4-to-C2H6 Photoconversion.

Photocatalytic conversion of methane (CH4) to ethane (C2H6) has attracted extensive attention from academia and industry. Typically, the traditional oxidative coupling of CH4 (OCM) reaches a high C2H6 productivity, yet the inevitable overoxidation limits the target product selectivity. Although the traditional nonoxidative coupling of CH4 (NOCM) can improve the product selectivity, it still encounters unsatisfied activity, arising from being thermodynamically unfavorable. To break the activity-selectivity trade-off, we propose a conceptually new mechanism of H2O2-triggered CH4 coupling, where the H2O2-derived ·OH radicals are rapidly consumed for activating CH4 into ·CH3 radicals exothermically, which bypasses the endothermic steps of the direct CH4 activation by photoholes and the interaction between ·CH3 and ·OH radicals, affirmed by in situ characterization techniques, femtosecond transient absorption spectroscopy, and density-functional theory calculation. By this pathway, the designed Au-WO3 nanosheets achieve unprecedented C2H6 productivity of 76.3 mol molAu-1 h-1 with 95.2% selectivity, and TON of 1542.7 (TOF = 77.1 h-1) in a self-designed flow reactor, outperforming previously reported photocatalysts regardless of OCM and NOCM pathways. Also, under outdoor natural sunlight irradiation, the Au-WO3 nanosheets exhibit similar activity and selectivity toward C2H6 production, showing the possibility for practical applications. Interestingly, this strategy can be applied to other various photocatalysts (Au-WO3, Au-TiO2, Au-CeO2, Pd-WO3, and Ag-WO3), showing a certain universality. It is expected that the proposed mechanism adds another layer to our understanding of CH4-to-C2H6 conversion.

Recycling Valuable Alkylbenzenes from Polystyrene through Methanol-Assisted Depolymerization.

The vast bulk of polystyrene (PS), a major type of plastic polymers, ends up in landfills, which takes up to thousands of years to decompose in nature. Chemical recycling promises to enable lower-energy pathways and minimal environmental impacts compared with traditional incineration and mechanical recycling. Herein, we demonstrated that methanol as a hydrogen supplier assisted the depolymerization of PS (denoted as PS-MAD) into alkylbenzenes over a heterogeneous catalyst composed of Ru nanoparticles on SiO2. PS-MAD achieved a high yield of liquid products which accounted for 93.2 wt % of virgin PS at 280 °C for 6 h with the production rate of 118.1 mmolcarbon gcatal. -1 h-1. The major components were valuable alkylbenzenes (monocyclic aromatics and diphenyl alkanes), the sum of which occupied 84.3 wt % of liquid products. According to mechanistic studies, methanol decomposition dominates the hydrogen supply during PS-MAD, thereby restraining PS aromatization which generates by-products of fused polycyclic arenes and polyphenylenes.

Development of Transmission Ambient Pressure Laser Desorption Ionization/Postphotoionization Mass Spectrometry Imaging.

Laser-based high-resolution mass spectrometry imaging at ambient conditions has promising applications in life science. However, the ion yield during laser desorption/ablation is poor. Here, transmission atmospheric pressure laser desorption ionization combined with a compact postphotoionization (t-AP-LDI/PI) assembly with a krypton discharge lamp was developed for the untargeted imaging of various biomolecules. The spatial distributions of numerous lipid classes, fatty acids, neurotransmitters, and amino acids in the subregions of mouse cerebellum tissue were obtained. Compared with single laser ablation, the sensitivities for most analytes were increased by 1 to 3 orders of magnitude by dopant-assisted postphotoionization. After careful optimization, a spatial resolution of 4 µm could be achieved for the metabolites in mouse hippocampus tissue. Finally, the melanoma tissue slices were analyzed using t-AP-LDI/PI MSI, which revealed the metabolic heterogeneity of the melanoma microenvironment and exhibited the phenomenon of abnormal proliferation and invasion trends in tumor cells.

CO2 Enrichment Boosts Highly Selective Infrared-Light-Driven CO2 Conversion to CH4 by UiO-66/Co9S8 Photocatalyst.

Photocatalytic CO2 reduction to high-value chemicals is an attractive approach to mitigate climate change, but it remains a great challenge to produce a specific product selectively by IR light. Hence, UiO-66/Co9S8 composite is designed to couple the advantages of metallic photocatalysts and porous CO2 adsorbers for IR-light-driven CO2-to-CH4 conversion. The metallic nature of Co9S8 endows UiO-66/Co9S8 with exceptional IR light absorption, while UiO-66 dramatically enhances its local CO2 concentration, revealed by finite-element method simulations. As a result, Co9S8 or UiO-66 alone does not show observable IR-light photocatalytic activity, whereas UiO-66/Co9S8 exhibits exceptional activity. The CH4 evolution rate over UiO-66/Co9S8 reaches 25.7 µmol g-1 h-1 with ca.100% selectivity under IR light irradiation, outperforming most reported catalysts under similar reaction conditions. The X-ray absorption fine structure spectroscopy spectra verify the presence of two distinct Co sites and confirm the existence of metallic Co─Co bond in Co9S8. Energy diagrams analysis and transient absorption spectra manifest that CO2 reduction mainly occurs on Co9S8 for UiO-66/Co9S8, while density functional theory calculations demonstrate that high-electron-density Co1 sites are the key active sites, possessing lower energy barriers for further protonation of *CO, leading to the ultra-high selectivity toward CH4.

Microbiologic surveys for Baijiu fermentation are affected by experimental design.

The traditional Chinese alcoholic beverage Baijiu is produced by spontaneous fermentation of grains under anaerobic conditions. While numerous studies have used metagenomic technology to investigate the microbiome of Baijiu brewing, the microbial succession mechanism of Baijiu brewing has not been fully clarified, and metagenomic strategies for microecology surveys have not been comprehensively evaluated. Using the fermentation process of strong-flavor Baijiu as a model, we compared the data for bacterial communities based on short read 16S rRNA variable regions, V3-V4, and full-length 16S regions, V1-V9, to whole metagenomic shotgun sequencing (WMS) to measure the effect of technology selection on phylogenetic and functional profiles. The results showed differences in bacterial compositions and their relation to volatiles and physicochemical variables between sequencing methods. Furthermore, the percentage of V3-V4 sequences assigned to species level was higher than the percentage of V1-V9 sequences according to SILVA taxonomy, but lower according to NCBI taxonomy (P < 0.05). In both SILVA and NCBI taxonomies, the relative abundances of bacterial communities at both the genus and family levels were more positively correlated with WMS data in the V3-V4 dataset than in the V1-V9 dataset. The WMS identified changes in abundances of multiple metabolic pathways during fermentation (P < 0.05), including "starch and sucrose metabolism," "galactose metabolism," and "fatty acid biosynthesis." Although functional predictions derived from 16S data show similar patterns to WMS, most metabolic pathway changes are uncorrelated (P > 0.05). This study provided new technical and biological insights into Baijiu production that may assist in selection of methodologies for studies of fermentation systems.

Online Exploring the Gaseous Oil Fumes from Oleic Acid Thermal Oxidation by Synchrotron Radiation Photoionization Mass Spectrometry.

Cooking oil fumes are an intricate and dynamic mixture containing a variety of poisonous and hazardous substances, and their real-time study remains challenging. Based on tunable synchrotron radiation photoionization mass spectrometry (SR-PIMS), isomeric/isobaric compounds in the gaseous oil fumes from oleic acid thermal oxidation were determined in real time and distinguished by photoionization efficiency (PIE) curve simulation combined with multiple linear regression (MLR) analysis. A series of common carcinogens such as formaldehyde, acetaldehyde, acrolein, and several unreported chemicals including diethyl ether and formylcyclohexane were successfully characterized. Moreover, time-resolved profiles of certain components in gaseous oil fumes were monitored for 55 h. Distinct evolutionary processes were observed, indicating the consumption and formation of parent molecules, intermediates, and final products.

Research progress on moyamoya disease combined with thyroid diseases.

Moyamoya disease (MMD), also known as abnormal cerebral vascular network disease, is characterized by progressive occlusion or stenosis of the internal carotid and cerebral arteries, as well as the formation of an abnormal cerebral vascular network. It can occur anywhere in the world but is most common in China, Japan, and the Republic of Korea. In recent years, there have been increasing reports on the coexistence of thyroid diseases and MMD, but the mechanism of their coexistence is still unclear. For this article, we used keywords such as "moyamoya disease", "thyroid", "Grave disease", "thyrotoxicosis", and "thyroid autoimmune antibodies" to search for 52 articles that met the requirements in medical databases such as PubMed and Web of Science. This article also reviews the research on the role of thyroid hormone, the mechanism of immune antibodies, the possible correlation between thyroid diseases and MMD disease genes, and the treatment methods, and discusses the possible relationship between MMD and thyroid diseases to provide a reference for the pathogenesis and treatment of MMD with thyroid diseases.

Study on the thermal oxidation of oleic, linoleic and linolenic acids by synchrotron radiation photoionization mass spectrometry.

RATIONALE: Cooking oil fumes contain numerous hazardous and carcinogenic chemicals, posing potential threats to human health. However, the sources of these species remain ambiguous, impeding health risk assessment, pollution control and mechanism research. METHODS: To address this issue, the thermal oxidation of three common unsaturated fatty acids (UFAs), namely oleic, linoleic and linolenic acids, present in vegetable oils was investigated. The volatile and semi-volatile products were comprehensively characterized by online synchrotron radiation photoionization mass spectrometry (SR-PIMS) with two modes, which were validated and complemented using offline gas chromatography (GC)/MS methods. Tunable SR-PIMS combined with photoionization efficiency curve simulation enabled the recognition of isomers/isobars in gaseous fumes. RESULTS: SR-PIMS revealed over 100 products, including aldehydes, alkenes, furans, aromatic hydrocarbons, etc., such as small molecules of formaldehyde, acetaldehyde, acrolein, ethylene and furan, which are not readily detected by conventional GC/MS; and some unreported fractions, e.g. ketene, 4-ethylcyclohexene and cycloundecene(E), were also observed. Furthermore, real-time monitoring of product emissions during the thermal oxidation of the three UFAs via SR-PIMS revealed that linolenic acid may be the major source of acrolein. CONCLUSION: SR-PIMS has been demonstrated as a powerful technique for online investigation of cooking oil fumes. This study achieved comprehensive characterization of volatile and semi-volatile products from the thermal oxidation of oleic, linoleic and linolenic acids, facilitating the traceability of species in cooking fumes and aiding in exploring the thermal reactions of different vegetable oils.

Research Progress of Dihydroquercetin in the Treatment of Skin Diseases.

Skin is a barrier to maintaining the stability of the human environment and preventing the invasion of pathogens. When skin tissue is exposed to the external environment, it will inevitably develop defects due to trauma, injury, burns, ulcers, surgery, and chronic diseases. Rapid skin repair is the key to reducing infection, relieving pain, and improving quality of life. Dihydroquercetin is a kind of flavonoid that has a wide range of pharmacological activities and can improve skin repair, skin inflammation, skin cancer, and so on. In this paper, the application of dihydroquercetin in medical dressings and the research progress in the treatment of skin-related diseases are reviewed, so as to provide reference for further developing dihydroquercetin as a drug for the treatment of skin diseases.

Low-dose LPS alleviates early brain injury after SAH by modulating microglial M1/M2 polarization via USP19/FOXO1/IL-10/IL-10R1 signaling.

BACKGROUND: Low-dose lipopolysaccharide (LPS) protects against early brain injury (EBI) after subarachnoid hemorrhage (SAH). However, the mechanism underlying the neuroprotective roles of low-dose LPS remain largely undefined. METHODS: A SAH mice model was established and the pathological changes of brain were evaluated by wet-dry weight method, HE and Nissl staining, and blood-brain barrier (BBB) permeability assay. Cell apoptosis and inflammation were monitored by TUNEL, flow cytometry and ELISA assays. qRT-PCR, immunofluorescence and Western blot were used to detect the expression of microglial polarization-related or oxidative stress-associated markers. Bioinformatics analysis, luciferase and ChIP assays were employed to detect the direct association between FOXO1 and IL-10 promoter. The ubiquitination of FOXO1 in the in vitro SAH model was detected by co-IP. RESULTS: Low-dose LPS alleviated SAH-induced neurological dysfunction, brain edema, BBB disruption, damage in the hippocampus, neuronal apoptosis and inflammation via modulating microglial M1/M2 polarization by IL-10/IL-10R1 signaling. Mechanistic studies showed that FOXO1 acted as a transcriptional activator of IL-10. USP19 mediated the deubiquitination of FOXO1 to activate IL-10/IL-10R1 signaling, thereby regulating microglial M1/M2 polarization. Functional experiments revealed that low-dose LPS upregulated USP19 to modulate microglial M1/M2 polarization via FOXO1/IL-10/IL-10R1 signaling in SAH mice. CONCLUSION: Low-dose LPS protected against EBI after SAH by modulating microglial M1/M2 polarization via USP19/FOXO1/IL-10/IL-10R1 signaling.

Bioinspired microenvironment modulation of metal-organic framework-based catalysts for selective methane oxidation.

Inspiration from natural enzymes enabling creationary catalyst design is appealing yet remains extremely challenging for selective methane (CH4) oxidation. This study presents the construction of a biomimetic catalyst platform for CH4 oxidation, which is constructed by incorporating Fe-porphyrin into a robust metal-organic framework, UiO-66, furnished with saturated monocarboxylic fatty acid bearing different long alkyl chains. The catalysts demonstrate the high efficiency in the CH4 to methanol (CH3OH) conversion at 50 °C. Moreover, the selectivity to CH3OH can be effectively regulated and promoted through a fine-tuned microenvironment by hydrophobic modification around the Fe-porphyrin. The long-chain fatty acids anchored on the Zr-oxo cluster of UiO-66 can not only tune the electronic state of the Fe sites to improve CH4 adsorption, but also restrict the amount of H2O2 around the Fe sites to reduce the overoxidation. This behavior resembles the microenvironment regulation in methane monooxygenase, resulting in high CH3OH selectivity.

Dual Lewis Acid-Base Sites Regulate Silver-Copper Bimetallic Oxide Nanowires for Highly Selective Photoreduction of Carbon Dioxide to Methane.

Highly selective photoreduction of CO2 to valuable hydrocarbons is of great importance to achieving a carbon-neutral society. Precisely manipulating the formation of the Metal1 ⋅⋅⋅C=O⋅⋅⋅Metal2 (M1 ⋅⋅⋅C=O⋅⋅⋅M2 ) intermediate on the photocatalyst interface is the most critical step for regulating selectivity, while still a significant challenge. Herein, inspired by the polar electronic structure feature of CO2 molecule, we propose a strategy whereby the Lewis acid-base dual sites confined in a bimetallic catalyst surface are conducive to forming a M1 ⋅⋅⋅C=O⋅⋅⋅M2 intermediate precisely, which can promote selectivity to hydrocarbon formation. Employing the Ag2 Cu2 O3 nanowires with abundant Cu⋅⋅⋅Ag Lewis acid-base dual sites on the preferred exposed {110} surface as a model catalyst, 100 % selectivity toward photoreduction of CO2 into CH4 has been achieved. Subsequent surface-quenching experiments and density functional theory (DFT) calculations verify that the Cu⋅⋅⋅Ag Lewis acid-base dual sites do play a vital role in regulating the M1 ⋅⋅⋅C=O⋅⋅⋅M2 intermediate formation that is considered to be prone to convert CO2 into hydrocarbons. This study reports a highly selective CO2 photocatalyst, which was designed on the basis of a newly proposed theory for precise regulation of reaction intermediates. Our findings will stimulate further research on dual-site catalyst design for CO2 reduction to hydrocarbons.

Cytomodulin-10 modified GelMA hydrogel with kartogenin for in-situ osteochondral regeneration.

The incidence of osteochondral defect is increasing year by year, but there is still no widely accepted method for repairing the defect. Hydrogels loaded with bioactive molecules have provided promising alternatives for in-situ osteochondral regeneration. Kartogenin (KGN) is an effective and steady small molecule with the function of cartilage regeneration and protection which can be further boosted by TGF-ß. However, the high cost, instability, and immunogenicity of TGF-ß would limit its combined effect with KGN in clinical application. In this study, a composite hydrogel CM-KGN@GelMA, which contained TGF-ß1 analog short peptide cytomodulin-10 (CM-10) and KGN, was fabricated. The results indicated that CM-10 modified on GelMA hydrogels exerted an equivalent role in enhancing chondrogenesis as TGF-ß1, and this effect was also boosted when combined with KGN. Moreover, it was revealed that CM-10 and KGN had a synergistic effect on promoting the chondrogenesis of BMSCs by up-regulating the expression of RUNX1 and SOX9 at both mRNA and protein levels in vitro. Finally, the composite hydrogel exhibited a satisfactory osteochondral defect repair effect in vivo, showing similar structures close to the native tissue. Taken together, this study has revealed that CM-10 may serve as an alternative for TGF-ß1 and can collaborate with KGN to accelerate chondrogenesis, which suggests that the fabricated CM-KGN@GelMA composite hydrogel can be acted as a potential scaffold for osteochondral defect regeneration. STATEMENT OF SIGNIFICANCE: Kartogenin and TGF-ß have shown great value in promoting osteochondral defect regeneration, and their combined application can enhance the effect and show great potential for clinical application. Herein, a functional CM-KGN@GelMA hydrogel was fabricated, which was composed of TGF-ß1 mimicking peptide CM-10 and KGN. CM-10 in hydrogel retained an activity like TGF-ß1 to facilitate BMSC chondrogenesis and exhibited boosting chondrogenesis by up-regulating RUNX1 and SOX9 when being co-applied with KGN. In vivo, the hydrogel promoted cartilage regeneration and subchondral bone reconstruction, showing similar structures as the native tissue, which might be vital in recovering the bio-function of cartilage. Thus, this study developed an effective scaffold and provided a promising way for osteochondral defect repair.