Alginate Oligosaccharides Alleviate Salt Stress in Rice Seedlings by Regulating Cell Wall Metabolism to Maintain Cell Wall Structure and Improve Lodging Resistance.

Salt stress is one of the major abiotic stresses that damage the structure and composition of cell walls. Alginate oligosaccharides (AOS) have been advocated to significantly improve plant stress tolerance. The metabolic mechanism by which AOS induces salt tolerance in rice cell walls remains unclear. Here, we report the impact of AOS foliar application on the cell wall composition of rice seedlings using the salt-tolerant rice variety FL478 and the salt-sensitive variety IR29. Data revealed that salt stress decreased biomass, stem basal width, stem breaking strength, and lodging resistance; however, it increased cell wall thickness. In leaves, exogenous AOS up-regulated the expression level of OSCESA8, increased abscisic acid (ABA) and brassinosteroids (BR) content, and increased ß-galacturonic activity, polygalacturonase activity, xylanase activity, laccase activity, biomass, and cellulose content. Moreover, AOS down-regulated the expression levels of OSMYB46 and OSIRX10 and decreased cell wall hemicellulose, pectin, and lignin content to maintain cell wall stability under salt stress. In stems, AOS increased phenylalamine ammonia-lyase and tyrosine ammonia-lyase activities, while decreasing cellulase, laccase, and ß-glucanase activities. Furthermore, AOS improved the biomass and stem basal width and also enhanced the cellulose, pectin, and lignin content of the stem, As a result, increased resistance to stem breakage strength and alleviated salt stress-induced damage, thus enhancing the lodging resistance. Under salt stress, AOS regulates phytohormones and modifies cellulose, hemicellulose, lignin, and pectin metabolism to maintain cell wall structure and improve stem resistance to lodging. This study aims to alleviate salt stress damage to rice cell walls, enhance resistance to lodging, and improve salt tolerance in rice by exogenous application of AOS.

Changes in planta K nutrient content altered the interaction pattern between Nicotiana benthamiana and Alternaria longipes.

Potassium (K) fertilisation has frequently been shown to enhance plant resistance against pathogens, though the mechanisms remain elusive. This study investigates the interaction dynamics between Nicotiana benthamiana and the pathogen Alternaria longipes under different planta K levels. On the host side, adding K activated the expressions of three NLR (nucleotide-binding domain and leucine-rich repeat-containing proteins) resistance genes, including NbRPM1, NbR1B23 and NbNBS12. Silencing these NLRs attenuated resistance in high-K (HK, 40.8 g/kg) plant, whereas their overexpression strengthened resistance in low-K (LK, 23.9 g/kg) plant. Typically, these NLRs mainly strengthened plant resistance via promoting the expression of pathogenesis-related genes (PRs), ROS burst and synthesis of antifungal metabolites in HK plant. On the pathogen side, the expression of effectors HKCSP1, HKCSP2 and LKCSP were shown to be related to planta K content. A. longipes mainly expressed effectors HKCSP1 and HKCSP2 in HK plant to interfere host resistance. HKCSP1 physically interacted with NbRPM1 to promote the degradation of NbRPM1, then attenuated related resistance in HK N. benthamiana. Meanwhile, HKCSP2 directly interacted with NbPR5 to suppress resistance in HK plant. In LK plant, A. longipes mainly deployed LKCSP that interacted with NbR1B23 to interfere reduce resistance in N. benthamiana. Overall, our research insights that both pathogen and host mobilise distinct strategies to outcompete each other during interactions in different K nutrient environments.

Budding mutation reprogrammed flavonoid biosynthesis in jujube by deploying MYB41 and bHLH93.

Budding mutations are known to cause metabolic changes in new jujube varieties; however, the mechanisms underlying these changes are still unclear. Here, we performed muti-omics analysis to decipher the detailed metabolic landscape of "Saimisu 1" (S1) and its budding mutation line "Saimisu 2" (S2) at all fruit stages. We found that the genes involved in the biosyntheses of flavonoids, phenylpropanoids, and amino acids were upregulated in S2 fruits at all stages, especially PAL and DFR, resulting in increased accumulation of related compounds in S2 mature fruits. Further co-expression regulatory network analysis showed that the transcription factors MYB41 and bHLH93 potentially regulated the expression of PAL and DFR, respectively, by directly binding to their promoters. Moreover, the overexpression of MYB41 or bHLH93 induced their expression levels to redirect the flux of the flavonoid biosynthetic pathway, eventually leading to high levels of related compounds in S2 fruits. Overall, this study revealed the metabolic variations between S1 and S2 and contributed to the understanding of the mechanisms underlying budding mutation-mediated metabolic variations in plants, eventually providing the basis for breeding excellent jujube varieties using budding mutation lines.

S-ABA Enhances Rice Salt Tolerance by Regulating Na+/K+ Balance and Hormone Homeostasis.

In order to explore the regulating role and the physiological and biochemical mechanisms of trans-abscisic acid (hereinafter referred as S-ABA) in the process of rice growth and development under salt stress, we took Chaoyou 1000 and Yuxiangyouzhan as materials and set up three salt concentration treatments, CK0 (Control treatment), N1 (50 mmol L-1 NaCl), and N2 (100 mmol L-1 NaCl), in potted trials; we aimed to study the mechanism of rice's response to salt stress from the perspective of agricultural traits and physiological biochemicals and to improve rice's resistance to salt stress through exogenously applying the regulating technology of S-ABA. The following results were obtained: Under salt stress, the growth of rice was significantly suppressed compared to CK0, exhibiting notable increases in agricultural indicators, photosynthesis efficiency, and the NA+ content of leaves. However, we noted a significant decrease in the K+ content in the leaves, alongside a prominent increase in NA+/K+ and a big increase in MDA (malondialdehyde), H2O2 (hydrogen peroxide), and O2- (superoxide anion). This caused the cytomembrane permeability to deteriorate. By applying S-ABA under salt stress (in comparison with salt treatment), we promoted improvements in agronomic traits, enhanced photosynthesis, reduced the accumulation of NA+ in leaves, increased the K+ content and the activity of antioxidant enzymes, and reduced the active oxygen content, resulting in a sharp decrease in the impact of salt stress on rice's development. The application of S-ABA decreased the endogenous ABA (abscisic acid) content under salt stress treatment but increased the endogenous GA (gibberellin) and IAA (indole acetic acid) contents and maintained the hormonal homeostasis in rice plants. To summarize, salt stress causes damage to rice growth, and the exogenous application of S-ABA can activate the pouring system mechanism of rice, suppress the outbreak of active oxygen, and regulate NA+/K+ balance and hormone homeostasis in the blades, thus relieving the salt stress.

Application of prohexadione-calcium priming affects Brassica napus L. seedlings by regulating morph-physiological characteristics under salt stress.

Salinity stress imposes severe constraints on plant growth and development. Here, we explored the impacts of prohexadione-calcium (Pro-Ca) on rapeseed growth under salt stress. We designed a randomized block design pot experiment using two rapeseed varieties, 'Huayouza 158R' and 'Huayouza 62'. We conducted six treatments, S0: non-primed + 0 mM NaCl, Pro-Ca+S0: Pro-Ca primed + 0 mM NaCl, S100: non-primed + 100 mM NaCl, Pro-Ca+S100: Pro-Ca primed + 100 mM NaCl, S150: non-primed + 150 mM NaCl, Pro-Ca+S150: Pro-Ca primed + 150 mM NaCl. The morphophysiological characteristics, and osmoregulatory and antioxidant activities were compared for primed and non-primed varieties. Our data analysis showed that salt stress induced morph-physiological traits and significantly reduced the antioxidant enzyme activities in both rapeseed varieties. The Pro-Ca primed treatment significantly improved seedlings, root, and shoot morphological traits and accumulated more dry matter biomass under salt stress. Compared to Huayouza 158R, Huayouza 62 performed better with the Pro-Ca primed treatment. The Pro-Ca primed treatment significantly enhanced chlorophyll content, net photosynthetic rate (Pn), stomatal conductance (Gs), transpiration rate (Tr), and actual photochemical quantum efficiency (ФPSII). Furthermore, the Pro-Ca primed treatment also improved ascorbic acid (ASA) content, superoxide dismutase (SOD), peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) activity, and stimulated the accumulation of soluble proteins. These findings strongly suggested that the Pro-Ca primed treatment may effectively counteract the negative impacts of salinity stress by regulating the morph-physiological and antioxidant traits.

5-ALA, DTA-6, and Nitrogen Mitigate NaCl Stress by Promoting Photosynthesis and Carbon Metabolism in Rice Seedlings.

A large number of dead seedlings can occur in saline soils, which seriously affects the large-scale cultivation of rice. This study investigated the effects of plant growth regulators (PGRs) and nitrogen application on seedling growth and salt tolerance (Oryza sativa L.), which is of great significance for agricultural production practices. A conventional rice variety, "Huang Huazhan", was selected for this study. Non-salt stress treatments included 0% NaCl (CK treatment), CK + 0.05 g N/pot (N treatment), CK + 40 mg·L-1 5-aminolevulinic acid (5-ALA) (A treatment), and CK + 30 mg·L-1 diethylaminoethyl acetate (DTA-6) (D treatment). Salt stress treatments included 0.3% NaCl (S treatment), N + 0.3% NaCl (NS treatment), A + 0.3% NaCl (AS treatment), and D + 0.3% NaCl (DS treatment). When 3 leaves and 1 heart emerged from the soil, plants were sprayed with DTA-6 and 5-ALA, followed by the application of 0.3% NaCl (w/w) to the soil after 24 h. Seedling morphology and photosynthetic indices, as well as carbohydrate metabolism and key enzyme activities, were determined for each treatment. Our results showed that N, A, and D treatments promoted seedling growth, photosynthesis, carbohydrate levels, and the activities of key enzymes involved in carbon metabolism when compared to the CK treatment. The A treatment had the most significant effect, with increases in aboveground dry weight and net photosynthetic rates (Pn) ranging from 17.74% to 41.02% and 3.61% to 32.60%, respectively. Stomatal limiting values (Ls) significantly decreased from 19.17% to 43.02%. Salt stress significantly inhibited seedling growth. NS, AS, and DS treatments alleviated the morphological and physiological damage of salt stress on seedlings when compared to the S treatment. The AS treatment was the most effective in improving seedling morphology, promoting photosynthesis, increasing carbohydrate levels, and key enzyme activities. After AS treatment, increases in aboveground dry weight, net photosynthetic rate, soluble sugar content, total sucrose synthase, and amylase activities were 17.50% to 50.79%, 11.39% to 98.10%, 20.20% to 80.85%, 21.21% to 33.53%, and 22.17% to 34.19%, respectively, when compared to the S treatment. In summary, foliar sprays of 5-ALA, DTA-6, and additional nitrogen fertilizer enhanced rice seedling growth, increased photosynthesis, lowered Ls values, and improved seedling salt tolerance. Spraying two regulators, 5-ALA and DTA-6, quantitatively increased the effect of nitrogen fertilizer, with comparable effects on NaCl stress regulation. This study provides the basis for efficient agricultural production.

Plant growth regulators mitigate oxidative damage to rice seedling roots by NaCl stress.

The aim of this experiment was to investigate the effects of exogenous sprays of 5-aminolevulinic acid (5-ALA) and 2-Diethylaminoethyl hexanoate (DTA-6) on the growth and salt tolerance of rice (Oryza sativa L.) seedlings. This study was conducted in a solar greenhouse at Guangdong Ocean University, where 'Huanghuazhan' was selected as the test material, and 40 mg/L 5-ALA and 30 mg/L DTA-6 were applied as foliar sprays at the three-leaf-one-heart stage of rice, followed by treatment with 0.3% NaCl (W/W) 24 h later. A total of six treatments were set up as follows: (1) CK: control, (2) A: 40 mg⋅ L-1 5-ALA, (3) D: 30 mg⋅ L-1 DTA-6, (4) S: 0.3% NaCl, (5) AS: 40 mg⋅ L-1 5-ALA + 0.3% NaCl, and (6) DS: 30 mg⋅ L-1 DTA-6+0.3% NaCl. Samples were taken at 1, 4, 7, 10, and 13 d after NaCl treatment to determine the morphology and physiological and biochemical indices of rice roots. The results showed that NaCl stress significantly inhibited rice growth; disrupted the antioxidant system; increased the rates of malondialdehyde, hydrogen peroxide, and superoxide anion production; and affected the content of related hormones. Malondialdehyde content, hydrogen peroxide content, and superoxide anion production rate significantly increased from 12.57% to 21.82%, 18.12% to 63.10%, and 7.17% to 56.20%, respectively, in the S treatment group compared to the CK group. Under salt stress, foliar sprays of both 5-ALA and DTA-6 increased antioxidant enzyme activities and osmoregulatory substance content; expanded non-enzymatic antioxidant AsA and GSH content; reduced reactive oxygen species (ROS) accumulation; lowered malondialdehyde content; increased endogenous hormones GA3, JA, IAA, SA, and ZR content; and lowered ABA content in the rice root system. The MDA, H2O2, and O2- contents were reduced from 35.64% to 56.92%, 22.30% to 53.47%, and 7.06% to 20.01%, respectively, in the AS treatment group compared with the S treatment group. In the DS treatment group, the MDA, H2O2, and O2- contents were reduced from 24.60% to 51.09%, 12.14% to 59.05%, and 12.70% to 45.20%. In summary, NaCl stress exerted an inhibitory effect on the rice root system, both foliar sprays of 5-ALA and DTA-6 alleviated damage from NaCl stress on the rice root system, and the effect of 5-ALA was better than that of DTA-6.

Major quality regulation network of flavonoid synthesis governing the bioactivity of black wolfberry.

Black wolfberry (Lycium ruthenicum Murr.) contains various bioactive metabolites represented by flavonoids, which are quite different among production regions. However, the underlying regulation mechanism of flavonoid biosynthesis governing the bioactivity of black wolfberry remains unclear. Presently, we compared the bioactivity of black wolfberry from five production regions. Multi-omics were performed to construct the regulation network associated with the fruit bioactivity. The detailed regulation mechanisms were identified using genetic and molecular methods. Typically, Qinghai (QH) fruit exhibited higher antioxidant and anti-inflammatory activities. The higher medicinal activity of QH fruit was closely associated with the accumulation of eight flavonoids, especially Kaempferol-3-O-rutinoside (K3R) and Quercetin-3-O-rutinoside (rutin). Flavonoid biosynthesis was found to be more active in QH fruit, and the upregulation of LrFLS, LrCHS, LrF3H and LrCYP75B1 caused the accumulation of K3R and rutin, leading to high medicinal bioactivities of black wolfberry. Importantly, transcription factor LrMYB94 was found to regulate LrFLS, LrCHS and LrF3H, while LrWRKY32 directly triggered LrCYP75B1 expression. Moreover, LrMYB94 interacted with LrWRKY32 to promote LrWRKY32-regulated LrCYP75B1 expression and rutin synthesis in black wolfberry. Transgenic black wolfberry overexpressing LrMYB94/LrWRKY32 contained higher levels of K3R and rutin, and exhibited high medicinal bioactivities. Importantly, the LrMYB94/LrWRKY32-regulated flavonoid biosynthesis was light-responsive, showing the importance of light intensity for the medicinal quality of black wolfberry. Overall, our results elucidated the regulation mechanisms of K3R and rutin synthesis, providing the basis for the genetic breeding of high-quality black wolfberry.

Spin Polarization of 2D Weyl Semimetal Fe2Sn Enabling High Hydrogen Evolution Reaction Activity.

It is well known that magnetic field is one of the effective tools to improve the activity of hydrogen evolution reaction (HER), but considering the inconvenient application of an external magnetic field, it is essential to find a ferromagnetic material with high HER activity itself. Fortunately, recent study has shown that the two-dimmention (2D) Fe2Sn monolayer is a stable ferromagnetic topological Weyl semimetal material with high Tc of 433 K. Here, we report the Fe2Sn monolayer can be used as an alternative HER catalyst compared with expensive platinum (Pt). Our first-principles results show that the Gibbs free energy (ΔGH*) value of the spin polarized Fe2Sn monolayer is -0.06 eV, much better than that without considering spin polarization (-1.23 eV). Moreover, the kinetic analysis demonstrates that the HER occurs on the Fe2Sn monolayer according to the Volmer-Tafel mechanism with low energy barriers. Hence, our findings provide obvious evidence for spin-polarization-improved HER activity, paving a new way to design high-performance HER catalysts.

Regulatory effects of Hemin on prevention and rescue of salt stress in rapeseed (Brassica napus L.) seedlings.

BACKGROUND: Salt stress severely restricts rapeseed growth and productivity. Hemin can effectively alleviate salt stress in plants. However, the regulatory effect of Hemin on rapeseed in salt stress is unclear. Here, we analyzed the response and remediation mechanism of Hemin application to rapeseed before and after 0.6% (m salt: m soil) NaCl stress. Experiment using two Brassica napus (AACC, 2n = 38) rapeseed varieties Huayouza 158R (moderately salt-tolerant) and Huayouza 62 (strongly salt-tolerant). To explore the best optional ways to improve salt stress resistance in rapeseed. RESULTS: Our findings revealed that exogenous application of Hemin enhanced morph-physiological traits of rapeseed and significantly attenuate the inhibition of NaCl stress. Compared to Hemin (SH) treatment, Hemin (HS) significantly improved seedlings root length, seedlings height, stem diameter and accumulated more dry matter biomass under NaCl stress. Moreover, Hemin (HS) significantly improved photosynthetic efficiency, activities of antioxidant enzymes such as superoxide dismutase (SOD), peroxidase (POD), ascorbate peroxidase (APX), and decreased electrolyte leakage (EL) and malondialdehyde (MDA) content, thus resulting in the alleviation of oxidative membrane damage. Hemin (HS) showed better performance than Hemin (SH) under NaCl stress. CONCLUSION: Hemin could effectively mitigate the adverse impacts of salt stress by regulating the morph-physiological, photosynthetic and antioxidants traits of rapeseed. This study may provide a basis for Hemin to regulate cultivated rapeseed salt tolerance and explore a better way to alleviate salt stress.

Combined transcriptomic and metabolomic analysis of alginate oligosaccharides alleviating salt stress in rice seedlings.

BACKGROUND: Salt stress is one of the key factors limiting rice production. Alginate oligosaccharides (AOS) enhance plant stress resistance. However, the molecular mechanism underlying salt tolerance in rice induced by AOS remains unclear. FL478, which is a salt-tolerant indica recombinant inbred line and IR29, a salt-sensitive rice cultivar, were used to comprehensively analyze the effects of AOS sprayed on leaves in terms of transcriptomic and metabolite profiles of rice seedlings under salt stress. RESULTS: In this experiment, exogenous application of AOS increased SOD, CAT and APX activities, as well as GSH and ASA levels to reduce the damage to leaf membrane, increased rice stem diameter, the number of root tips, aboveground and subterranean biomass, and improved rice salt tolerance. Comparative transcriptomic analyses showed that the regulation of AOS combined with salt treatment induced the differential expression of 305 and 1030 genes in FL478 and IR29. The expressed genes enriched in KEGG pathway analysis were associated with antioxidant levels, photosynthesis, cell wall synthesis, and signal transduction. The genes associated with light-trapping proteins and RLCK receptor cytoplasmic kinases, including CBA, LHCB, and Lhcp genes, were fregulated in response to salt stress. Treatment with AOS combined with salt induced the differential expression of 22 and 50 metabolites in FL478 and IR29. These metabolites were mainly related to the metabolism of amino and nucleotide sugars, tryptophan, histidine, and ß -alanine. The abundance of metabolites associated with antioxidant activity, such as 6-hydroxymelatonin, wedelolactone and L-histidine increased significantly. Combined transcriptomic and metabolomic analyses revealed that dehydroascorbic acid in the glutathione and ascorbic acid cycles plays a vital role in salt tolerance mediated by AOS. CONCLUSION: AOS activate signal transduction, regulate photosynthesis, cell wall formation, and multiple antioxidant pathways in response to salt stress. This study provides a molecular basis for the alleviation of salt stress-induced damage by AOS in rice.

Sufficient coumarin accumulation improves apple resistance to Cytospora mali under high-potassium status.

Cytospora canker, caused by Cytospora mali, is the most destructive disease in production of apples (Malus domestica). Adding potassium (K) to apple trees can effectively control this disease. However, the underlying mechanisms of apple resistance to C. mali under high-K (HK) status remain unknown. Here, we found that HK (9.30 g/kg) apple tissues exhibited high disease resistance. The resistance was impeded when blocking K channels, leading to susceptibility even under HK conditions. We detected a suite of resistance events in HK apple tissues, including upregulation of resistance genes, callose deposition, and formation of ligno-suberized tissues. Further multiomics revealed that the phenylpropanoid pathway was reprogrammed by increasing K content from low-K (LK, 4.30 g/kg) status, leading to increases of 18 antifungal chemicals. Among them, the physiological concentration of coumarin (1,2-benzopyrone) became sufficient to inhibit C. mali growth in HK tissues, and exogenous application could improve the C. mali resistance of LK apple branches. Transgenic apple calli overexpressing beta-glucosidase 40 (MdBGLU40), which encodes the enzyme for coumarin synthesis, contained higher levels of coumarin and exhibited high resistance to C. mali even under LK conditions. Conversely, the suppression of MdBGLU40 through RNAi reduced coumarin content and resistance in HK apple calli, supporting the importance of coumarin accumulation in vivo for apple resistance. Moreover, we found that the upregulation of transcription factor MdMYB1r1 directly activated MdBGLU40 and the binding affinity of MdMYB1r1 to the MdBGLU40 promoter increased in HK apple tissue, leading to high levels of coumarin and resistance in HK apple. Overall, we found that the accumulation of defensive metabolites strengthened resistance in apple when raising K from insufficient to optimal status, and these results highlight the optimization of K content in fertilization practices as a disease management strategy.

ß-Carboline dimers inhibit the tumor proliferation by the cell cycle arrest of sarcoma through intercalating to Cyclin-A2.

ß-Carbolines are potentially strong alkaloids with a wide range of bioactivities, and their dimers exhibit stronger antitumor activity other than the monomers. However, the detailed mechanisms of the ß-carboline dimers in inhibiting sarcoma (SARC) remain unclear. The results showed that ß-carboline-3-carboxylic acid dimers Comp1 and Comp2, which were synthesized in our lab and modified at the N9 position and linked at the C3 position, exhibited effective inhibition activity on MG-63 proliferation (IC50 = 4.6µM). Meanwhile, the large scale transcriptome profiles of SARC from The Cancer Genome Atlas (TCGA) were analyzed, and found that abnormal expression of genes relevant to apoptosis, cell cycle, and signaling pathways of Hedgehog, HIF, Ras involved in the SARC pathogenesis. Interestingly, both dimers could promote the apoptosis and arrest the cell cycle in S phase to inhibit proliferation of MG-63. Moreover, Comp1 and Comp2 inhibited the expression CDK2, CCNA2, DBF4, and PLK1 associated with various immune cells and cell cycle in MG-63. Remarkably, drug-target interaction network analysis showed that numerous proteins involved in cell cycle were the potential targets of Comp1 and Comp2, especially CCNA2. Further molecular docking, isothermal titration calorimetry (ITC) and Cellular Thermal Shift Assay (CETSA) confirmed that both dimers could directly interact with CCNA2, which is significantly correlated with CD4+ T cells, by strong hydrophobic interactions (Kd=5.821 ×106 N). Meanwhile, the levels of CCNA2 and CDK2 were inhibited to decrease in MG-63 by both dimer treatments at transcription and protein levels, implying that Comp1 and Comp2 blocked the interaction between CCNA2 and CDK2 through competitive binding with CCNA2 to arrest the cell cycle of MG-63 cells in the S phase. Additionally, the transcriptome profiles of ß-carboline-treated mice from Gene Expression Omnibus (GEO) were obtained, and found that similar antitumor mechanism was shared among ß-carboline derivatives. Overall, our results elucidated the antitumor mechanisms of Comp1 and Comp2 through dual-suppressing the function of CCNA2 to profoundly arrest cell cycle of MG-63, then effectively inhibited cell proliferation of MG-63. These results provide new insights into the antitumor mechanism of ß-carboline dimers and new routes of various novel cancer-related drug targets for future possible cancer therapy.

Morphology optimization strategy of flower-like CoNi2S4/Co9S8@MoS2 core@shell nanocomposites to achieve extraordinary microwave absorption performances.

Morphology optimization is an effective strategy to take full advantage of interface polarization for the improvement of electromagnetic wave attenuation capability. Herein, a general route was proposed to produce the flower-like core@shell structured MoS2-based nanocomposites through a simple hydrothermal process. Through the in-situ hydrothermal reaction between the Mo and S sources on the surface of CoNi nanoparticles, flower-like core@shell structured CoNi2S4/Co9S8@MoS2 nanocomposites could be successfully synthesized. By regulating the hydrothermal temperature, the flower-like geometrical morphology of samples could be effectively optimized, and the as-prepared sample (S2) synthesized at 200 °C displayed very excellent flower-like morphology compared to the samples (S1 and S3) obtained at 180 and 220 °C. Owing to the excellent interface polarization effect, the as-prepared S2 presented the evidently superior comprehensive microwave absorption properties in terms of strong aborption capability, wide absorption bandwidth and thin matching thicknesses compared to those of S1 and S3. The as-prepared core@shell structured CoNi2S4/Co9S8@MoS2 sample with very excellent flower-like morphology simultaneously displayed the minimal reflection loss of -50.61 dB with the matching thickness of 2.98 mm, and the effective absorption bandwidth of 8.40 GHz with the matching thickness of 2.36 mm. Therefore, we provided a general route for the production of flower-like core@shell structured MoS2-based nanocomposites, which could make the best of interface polarization to develop high-efficiency microwave absorbers.

Magnetic modulation of core@shell MoS2-based flower-like multicomponent nanocomposites to improve microwave attenuation.

Nanocomposites with a three-dimensional (3D) flower-like geometrical morphology were considered as excellent microwave absorbers (MAs) because of the numerous effective sites for the multiple reflections of electromagnetic (EM) wave. Herein, for optimizing the EM matching characteristic and taking full advantage of interface polarization, a strategy of magnetic modulation was proposed to further improve the EM wave absorption performances (EMWAPs) of MoS2-based nanocomposites. We adopted a simple hydrothermal route and a combined method of hydrothermal treatment/hydrogen reduction to synthesize core@shell CoFe2O4@MoS2 and CoFe@MoO2/MoS2 flower-like nanocomposites, respectively. The obtained results indicated that the hydrogen reduction effectively improved their magnetic properties and magnetic loss capabilities, and their 3D flower-like geometrical morphologies were well maintained during the hydrogen reduction process. The obtained core@shell CoFe@MoO2/MoS2 flower-like nanocomposites presented the extraordinary comprehensive EMWAPs including the optimal reflection loss value of -54.83 dB with the matching thicknesses (dm) value of 2.05 mm and effective absorption bandwidth value of 6.40 GHz with the dm value of 2.59 mm, which were evidently superior to the properties of CoFe2O4@MoS2. Therefore, the findings provided an effective pathway to further improve EMWAPs of MoS2-based core@shell nanocomposites and the as-prepared core@shell CoFe@MoO2/MoS2 flower-like nanocomposites could be utilized as the novel high-efficient MAs.

Functions of 1,25-dihydroxy vitamin D3, vitamin D3 receptor and interleukin-22 involved in pathogenesis of gout arthritis through altering metabolic pattern and inflammatory responses.

BACKGROUND: Gouty arthritis (GA) is a common type of inflammatory arthritis. Recent studies demonstrated that 1,25-dihydroxy vitamin D3 (1,25(OH) 2 VD3) and vitamin D3 receptor (VD-R) play a protective role in acute inflammation, but interleukin-22(IL-22) promotes inflammation, especially for arthritis. However, our understanding of the responses of 1,25(OH) 2VD3 and IL-22 to gout was still unclear. Presently, in-depth metabolomics, bioinformatics and clinical characteristics analyses were performed to elucidate the pathogenesis and valuable clinical indicators of gouty arthritis. METHODS: Peripheral venous blood was taken for investigation. The levels of IL-22 and 1,25(OH)2VD3 were determined in patient's plasma via ELISA, and the mRNA levels of IL-22 and VD-R were measured via qRT-PCR. The interaction network of VD-R and IL22 were constructed by the Search Tool for the Retrieval of Interacting Genes/Proteins (STRING), and the biological function of the related proteins were analyzed by Clusterprofiler Metabolomics were performed to decipher the metabolic variations of GA. RESULTS: The levels of VD-R and 1,25(OH) 2 VD3 were identified to be low. What,s more, GA patients were reported to have high expression of IL-22. And IL-22 levels positively correlated with C-reactiveprotein (CRP) serum levels in the bivariate correlation analysis, whereas the level of 1,25(OH) 2VD3 negatively correlated with that of CRP. GO and KEGG analyses revealed that IL-22 and 1,25(OH) 2 VD3 were involved in stress immunity and inflammatory responses. These pathways are known to play a role in GA pathogenesis. Meanwhile, the metabolic profiles of GA serum showed that the increase in various amino acids and uric acid are involved in GA pathogenesis. Importantly, VD-R and IL22 closely correlated with the level of key metabolites uric acid, whose increase promoted the occurrence of GA. CONCLUSION: GA patients have low levels of VD-R and 1,25(OH) 2 VD3, and high levels of IL-22 together with various amino acids and uric acid. The levels of IL-22 and 1,25(OH) 2VD3 were positively and negatively correlated with C-reactive protein (CRP) serum levels, respectively. Both IL-22 and 1,25(OH) 2 VD3 functioned in GA-related immune and inflammatory responses, and closely correlated with the level of GA-related uric acid. Overall, IL-22, VD-R and 1,25(OH) 2 VD3 play functionally important roles in inflammatory responses and are relevant to gout pathogenesis.

Enhancing the Curie temperature of two-dimensional monolayer CrI3 by introducing I-vacancies and interstitial H-atoms.

The discovery of two-dimensional monolayer CrI3 provides a promising possibility for developing spintronic devices. However, the low Curie temperature is an obstacle for practical applications. Here, based on the consideration of the superexchange interaction of ferromagnetic coupling, we investigate the effect of introducing I-vacancies and interstitial H-atoms on the Curie temperature of monolayer CrI3 by using first-principles calculations and Monte Carlo simulations. Our theoretical conclusions show that the Curie temperature of Cr8I23 (CrI2.875), Cr8I22 (CrI2.75) and Cr8I24H (CrI3H0.125) significantly increases to 97.0, 82.5 and 112.4 K, respectively. Moreover, the magnetic moment of the Cr atom increases from 3.10 to 3.45 and 3.46µB in monolayers Cr8I23 and Cr8I22, respectively. We provide more alternative approaches to effectively enhance the Curie temperature of monolayer CrI3, which will help both theoretical and experimental researchers to directly predict the change in Curie temperature of CrI3 and its analogs through structural information.

Universal Fluorination-Created Edge C-F Groups in Networks of Multidimensional Carbon Materials.

Fluorination can significantly change the physical and chemical properties of carbon materials (CMs). Common sense for the fluorination mechanism for CMs indicates that one basal-plane C-F group (CF group) can form as one fluorine atom bonded to one carbon atom along the out-of-plane carbon networks without creating edge C-F groups (including CF2 and CF3 groups) at vacancies in carbon networks. We report that fluorination can generally create edge C-F groups in multidimensional CMs such as graphite, graphene, carbon nanotubes, and fullerene, and the concentration of edge C-F groups is dependent on both the crystallinity of starting CMs and the fluorination pressure and temperature. As an example, we show the significant differences in the band gap opening, photoluminescence, and magnetic properties between two half-fluorinated graphenes with different concentrations of edge C-F groups. Our findings highlight the importance of fluorination in creating edge C-F groups in the structure and properties and introduce new insight into fluorinated CMs.

Orientational Alignment of Oxygen Vacancies: Electric-Field-Inducing Conductive Channels in TiO2 Film to Boost Photocatalytic Conversion of CO2 into CO.

Oxide semiconductors are widely used in the photocatalytic fields, and introducing oxygen vacancies is an effective strategy to improve their photocatalytic efficiency. However, oxygen vacancies in the bulk often act as the recombination centers of electron-hole pairs, which accelerates the recombination of electron-hole pairs. In this paper, we propose a strategy of electric field treatment and apply it to a TiO2 film with oxygen vacancies to promote the photocatalytic efficiency. After treatment by an electric field, the conductive channels consisting of oxygen vacancies are formed in the TiO2 film, which greatly decreases the resistance by almost 6 × 103 times. The yield of CO can reach up to 1.729 mmol gcat-1 h-1, which is one of the best performances among the reported TiO2-based catalysts. This work provides an effective and feasible way for enhancing photocatalytic activity through an electric field, and this method is promising for wide use in the field of catalysis.

Realization of Strong Room-Temperature Ferromagnetism in Atomically Thin 2D Carbon Nitride Sheets by Thermal Annealing.

The presence of the intrinsic band gap of 3.06 eV makes atomically thin carbon nitride sheets (CNs) a promising spin-based semiconductor material. However, the absence of localized spins makes the pristine CNs intrinsically nonmagnetic. Here we report the realization of strong room-temperature (RT) ferromagnetism with a high Curie temperature of ca. 524.2 K in atomically thin 2D CNs by annealing pristine CNs at 700 °C. In particular, the RT saturated magnetization reaches as high as 0.71 emu/g, which is the highest value reported so far in carbon-based materials. The structural characterization combined with density functional theory calculations reveals that (i) the seven C-C bonds per unit cell were formed after annealing and (ii) the C-C bonds can introduce high-density localized spins and realize the long-range ferromagnetic couplings among these spins.