Ruthenium atoms anchored on oxygen-modified molybdenum disulfide with strong interfacial coupling as efficient and stable catalysts for lithium-oxygen batteries.

Rechargeable non-aqueous lithium-oxygen batteries (LOBs) have garnered increasing attention owing to their high theoretical energy density. However, their slow cathodic kinetics hinder efficient battery reactions. Nanoscale catalysts can effectively enhance electrocatalytic activity and atomic utilization efficiency. However, the agglomeration of nanoscale catalysts (such as cluster and single atoms) during continuous discharge/charge cycles leads to decreased electrochemical performance and poor cyclic stability. Herein, the ruthenium (Ru) atomic sites anchored on an O-doped molybdenum disulfide (O-MoS2) catalyst (designated as Ru/O-MoS2) was fabricated using a facile impregnation and calcination method. Strong Ru-O coupling between Ru atoms and the O-MoS2 substrate optimizes the localized electronic structure, resulting in improved electrochemical performance and enhanced resistance to Ostwald ripening. When employed as a cathode catalyst for LOBs, Ru/O-MoS2 catalyst exhibits a high reversible specific capacity (18700.5 (±59.8) mAh g-1), good rate capability, and enhanced long-term stability (115 cycles, 1200 h). This study encourages facile and efficient strategies for the development of effective and stable electrocatalysts for use in LOBs.

Plasma Induced Atomic-Scale Soldering Enhanced Efficiency and Stability of Electrocatalysts for Ampere-Level Current Density Water Splitting.

Industrial water electrolysis typically operates at high current densities, the efficiency and stability of catalysts are greatly influenced by mass transport processes and adhesion with substrates. The core scientific issues revolve around reducing transport overpotential losses and enhancing catalyst-substrate binding to ensure long-term performance. Herein, vertical Ni-Co-P is synthesized and employed plasma treatment for dual modification of its surface and interface with the substrate. The (N)Ni-Co-P/Ni3N cathode exhibits an ultra-low overpotential of 421 mV at 4000 mA cm-2, and the non-noble metal system only requires a voltage of 1.85 V to reach 1000 mA cm-2. When integrated into an anion exchange membrane (AEM) electrolyzer, it can operate stably for >300 h at 500 mA cm-2. Under natural light, the solar-driven AEM electrolyzer operates at a current density up to 1585 mA cm-2 with a solar-to-hydrogen efficiency (SHT) of 9.08%. Density functional theory (DFT) calculations reveal that plasma modification leads to an "atomic-scale soldering" effect, where the Ni3N strong coupling with the Co increases free charge density, simultaneously enhancing stability and conductivity. This research offers a promising avenue for optimizing ampere-level current density water splitting, paving the way for efficient and sustainable industrial hydrogen production.

A highly reactive soybean oil-based superhydrophobic polyurethane film with long-lasting antifouling and abrasion resistance.

Superhydrophobic polyurethanes offer robust hydrophobicity and corrosion resistance. However, it is essential to consider the durability and environmental constraints associated with these materials. This study prepared a bio-based superhydrophobic polyurethane coating film using epoxidized soybean oil, superhydrophobically modified silica nanoparticles, and OH-PDMS-OH as surface modifiers. The coating film exhibited sustained super-hydrophobicity and an excellent antifouling effect for pu-erh tea and edible oils, among other substances, after 14 days of immersion in solutions with different pH values, 28 days of exposure to air, and 2000 abrasion cycles. This finding can be applied to the development of daily indoor and outdoor antifouling protective coatings and provides a new method for the preparation of green and durable superhydrophobic antifouling coating films.

Room-Temperature Quantum Coherence of Reversible Photo-generated Radical and Its Film.

Electron spin qubits are becoming an important research direction in the field of quantum computing and information storage. However, the quantum decoherence has seriously hindered the development of this field. So far, few qubits exhibit long phase memory time (Tm), and even fewer qubits that can reach room temperature. Some reports show that the coherence times of radicals are generally long, so radicals may be the preferred spin carriers for qubits. Here, we demonstrate the qubit properties of a photogenerated radical (1a) based on 2,4,6-Tri(4-pyridyl)-1,3,5-triazine (tpt, 1). More importantly, the photogenerated radical is a spin self-diluting complex, which the dilution is generally used in the investigation of qubits to reduce the interference of environment on qubits in order to overcome the decoherence of qubits. It is surprised that radical tpt has a stable Tm = 1.1 µs above 20 K, even keep it to room temperature. In addition, the tpt-film prepared by the vacuum evaporation is significantly increase the T1 and Tm at low temperature.

Pseudoginsenoside-F11 reduces cognitive impairment and white matter injury in vascular dementia by alleviating autophagy-lysosomal pathway deficiency.

BACKGROUND: Vascular dementia (VaD) resulting from chronic cerebral hypoperfusion (CCH) induces cognitive impairment and white matter injury (WMI). We previously found that CCH induces dysfunction of the autophagy-lysosomal pathway (ALP) in white matter (WM) of rats. Enhancing oligodendrocyte autophagy to counteract ALP deficiency is beneficial for cognitive recovery. Pseudogenoside-F11 (PF11), a saponin extracted from Panax quinquefolium l., provides neuroprotective benefits in many animal models of cerebral ischemia and dementia. PURPOSE: To investigate how PF11 affects cognitive deterioration in rats with VaD induced by two vessel occlusion (2VO), and to determine if PF11 regulates ALP dysfunction in WM. METHODS: CCH-related VaD was induced in rats using the 2VO method. PF11 (6, 12, 24 mg/kg, intragastric administration) was given continuously for 4 weeks postoperatively. Behavioral tests related to cognitive function were performed on the 28th day following 2VO. Transmission electron microscopy, immunofluorescence, western blotting and Luxol fast blue staining were used to assess the WMI and the mechanism of action of PF11 in 2VO-induced VaD. RESULTS: PF11 (12 mg/kg) ameliorated 2VO-induced cognitive impairment. PF11 also alleviated WMI on the 28th day following 2VO, as characterized by reduction of neuronal axonal demyelination and axonal loss. Furthermore, PF11 prevented mature oligodendrocytes death by attenuating ALP deficiency in WM on the 14th day following 2VO, as manifested by enhancement of mechanistic target of rapamycin-mediated autophagy and lysosomal function, thereby reducing the aberrant accumulation of autophagy substrates and increasing the level of autophagosomes in WM. In addition, PF11 also prevented microglia and astrocytes from activating in WM on the 28th day following 2VO. CONCLUSION: PF11 significantly ameliorates cognitive impairment and WMI, and the mechanism is at least partly related to lessening ALP dysfunction in WM by enhancing autophagy and reducing lysosomal defects in oligodendrocytes.

Genomics- and Transcriptomics-Guided Discovery of Clavatols from Arctic Fungi Penicillium sp. MYA5.

Clavatols exhibit a wide range of biological activities due to their diverse structures. A genome mining strategy identified an A5cla cluster from Penicillium sp. MYA5, derived from the Arctic plant Dryas octopetala, is responsible for clavatol biosynthesis. Seven clavatols, including one new clavatol derivate named penicophenone F (1) and six known clavatols (2-7), were isolated from Penicillium sp. MYA5 using a transcriptome mining strategy. These structures were elucidated by comprehensive spectroscopic analysis. Antibacterial, aldose reductase inhibition, and siderophore-producing ability assays were conducted on compounds 1-7. Compounds 1 and 2 demonstrated inhibitory effects on the ALR2 enzyme with inhibition rates of 75.3% and 71.6% at a concentration of 10 µM, respectively. Compound 6 exhibited antibacterial activity against Staphylococcus aureus and Escherichia coli with MIC values of 4.0 µg/mL and 4.0 µg/mL, respectively. Additionally, compounds 1, 5, and 6 also showed potential iron-binding ability.

Antimicrobial Nonisocyanate Polyurethane Foam Derived from Lignin for Wound Healing.

Medical dressings, as a cover for wounds, can replace damaged skin in the wound healing process to play a temporary barrier role, avoid or control wound infection, and provide a favorable environment for wound healing. Therefore, there is an urgent need for medical antimicrobial dressings for the treatment of chronic wounds. Although traditional polyurethane foam has been widely used in medical dressings, conventional polyurethane foams are primarily prepared using nonbiocompatible isocyanate-based compounds, which are potentially hazardous for both operators and applications in the medical field. Here, we propose nonisocyanate polyurethane foams naturally derived from lignin by enzymatic lignin alkylation, cyclic carbonation modification, and polymerization with diamine and the addition of a blowing agent. Silver nanoparticle solution was added during foaming to confer antimicrobial properties. This lignin-based nonisocyanate polyurethane/silver composite foam (named NIPU foam-silver) using a green synthesis method has good mechanical properties, which can be used to manufacture polyurethane/silver foams, and thermal and antimicrobial properties. Notably, NIPU foam-Ag showed more than 95% bactericidal efficacy against both Escherichia coli and Staphylococcus aureus within 4 h. Evaluation of in vitro wounds in mice showed that this antimicrobial composite foam rapidly promotes wound healing and repairs damaged tissue. This suggests that this biobased biodegradable antimicrobial foam has significant scope for clinical applications in wound management.

Sustainable Janus lignin-based polyurethane biofoams with robust antibacterial activity and long-term biofilm resistance.

Conventional antibiotic therapies have been becoming less efficient due to increasingly, and sometimes fully, antibiotic-resistant bacterial strains, sometimes known as "superbacteria" or "superbugs." Thus, novel antibacterial materials to effectively inhibit or kill bacteria are crucial for humanity. As a broad-spectrum antimicrobial agent, silver nanoparticles (Ag NPs) have been the most widely commercialized of biomedical materials. However, long-term use of significant amounts of Ag NPs can be potentially harmful to human health through a condition known as argyria, in addition to being toxic to many environmental systems. It is, thus, highly necessary to reduce the amount of Ag NPs employed in medical treatments while also ensuring maintenance of antimicrobial properties, in addition to reducing the overall cost of treatment for humanitarian utilization. For this purpose, naturally sourced antimicrobial polylysine (PL) is used to partially replace Ag NPs within the materials composition. Accordingly, a series of PL, Ag NPs, and lignin-based polyurethane (LPU) composite biofoams (LPU-PL-Ag) were prepared. These proposed composite biofoams, containing at most only 2 % PL and 0.03 % Ag NPs, significantly inhibited the growth of both Gram-positive and Gram-negative bacteria within 1 h and caused irreversibly destructive bactericidal effects. Additionally, with a layer of polydimethylsiloxane (PDMS) on the surface, PDMS-LPU-PL(2 %)-Ag(0.03 %) can effectively prevent bacterial adhesion with a clearance rate of about 70 % for both bacterial biofilms within three days and a growth rate of more than 80 % for mouse fibroblasts NIH 3 T3. These lignin-based polyurethane biofoam dressings, with shorter antiseptic sterilization times and broad-spectrum antibacterial effects, are extremely advantageous for infected wound treatment and healing in clinical use.

Spin Qubit in a 2D GdIII NaI -Based Oxamato Supramolecular Coordination Framework.

Qubits are the basic unit of quantum information and computation. To realize quantum computing and information processing, the decoherence times of qubits must be long enough. Among the studies of molecule-based electron spin qubits, most of the work focused on the ions with the spin S=1/2, where only single-bit gates can be constructed. However, quantum operations require the qubits to interact with each other, so people gradually carry out relevant research in ions or systems with S>1/2 and multilevel states. In this work, a two-dimensional (2D) oxygen-coordinated GdIII NaI -based oxamato supramolecular coordination framework, Na[Gd(4-HOpa)4 (H2 O)] ⋅ 2H2 O (1, 4-HOpa=N-4-hydroxyphenyloxamate), was selected as a possible carrier of qubit. The field-induced slow magnetic relaxation shows this system has phonon bottleneck (PB) effect at low temperatures with a very weak magnetic anisotropy. The pulse electron paramagnetic resonance studies show the spin-lattice and spin-spin relaxation times are T1 =1.66 ms at 4 K and Tm =4.25 µs at 8 K for its diamagnetically diluted sample (1Gd0.12 %). It suggested that the relatively long decoherence time is mainly ascribed to its near isotropic and the PB effect from resonance phonon trapped for pure sample, while the dilution further improves its qubit performance.

High-Performance, Light-Stimulation Healable, and Closed-Loop Recyclable Lignin-Based Covalent Adaptable Networks.

In this work, high-performance, light-stimulation healable, and closed-loop recyclable covalent adaptable networks are successfully synthesized from natural lignin-based polyurethane (LPU) Zn2+ coordination structures (LPUxZy). Using an optimized LPU (LPU-20 with a tensile strength of 28.4 ± 3.5 MPa) as the matrix for Zn2+ coordination, LPUs with covalent adaptable coordination networks are obtained that have different amounts of Zn. When the feed amount of ZnCl2 is 9 wt%, the strength of LPU-20Z9 reaches 37.3 ± 3.1 MPa with a toughness of 175.4 ± 4.6 MJ m-3 , which is 1.7 times of that of LPU-20. In addition, Zn2+ has a crucial catalytic effect on "dissociation mechanism" in the exchange reaction of LPU. Moreover, the Zn2+ -based coordination bonds significantly enhance the photothermal conversion capability of lignin. The maximum surface temperature of LPU-20Z9 reaches 118 °C under the near-infrared illumination of 0.8 W m-2 . This allows the LPU-20Z9 to self-heal within 10 min. Due to the catalytic effect of Zn2+ , LPU-20Z9 can be degraded and recovered in ethanol completely. Through the investigation of the mechanisms for exchange reaction and the design of the closed-loop recycling method, this work is expected to provide insight into the development of novel LPUs with high-performance, light-stimulated heal ability, and closed-loop recyclability; which can be applied toward the expanded development of intelligent elastomers.

Enhancement of oligodendrocyte autophagy alleviates white matter injury and cognitive impairment induced by chronic cerebral hypoperfusion in rats.

Cognitive impairment caused by chronic cerebral hypoperfusion (CCH) is associated with white matter injury (WMI), possibly through the alteration of autophagy. Here, the autophagy-lysosomal pathway (ALP) dysfunction in white matter (WM) and its relationship with cognitive impairment were investigated in rats subjected to two vessel occlusion (2VO). The results showed that cognitive impairment occurred by the 28th day after 2VO. Injury and autophagy activation of mature oligodendrocytes and neuronal axons sequentially occurred in WM by the 3rd day. By the 14th day, abnormal accumulation of autophagy substrate, lysosomal dysfunction, and the activation of mechanistic target of rapamycin (MTOR) pathway were observed in WM, paralleled with mature oligodendrocyte death. This indicates autophagy activation was followed by ALP dysfunction caused by autophagy inhibition or lysosomal dysfunction. To target the ALP dysfunction, enhanced autophagy by systemic rapamycin treatment or overexpression of Beclin1 (BECN1) in oligodendrocytes reduced mature oligodendrocyte death, and subsequently alleviated the WMI and cognitive impairment after CCH. These results reveal that early autophagy activation was followed by ALP dysfunction in WM after 2VO, which was associated with the aggravation of WMI and cognitive impairment. This study highlights that alleviating ALP dysfunction by enhancing oligodendrocyte autophagy has benefits for cognitive recovery after CCH.

Oral administration of heat-inactivated Escherichia coli during suckling alleviated Salmonella typhimurium-derived intestinal injury after rat weaning.

Introduction: Newly weaned animals are susceptible to a wide range of microbial infections taking a high risk of developing post-weaning diarrhea. Trained immunity is the capacity of the innate immune system to produce a stronger and non-specific response against a secondary infection after the inflammatory response caused by previous stimulus has returned to normal state. The objective of this study was to evaluate if the heat-inactivated Escherichia coli (IEC) as an immunostimulant on suckling pups elicits a protective effect on the intestine of post-weaning rats challenged with Salmonella Typhimurium (S.Typhimurium). We adapted a newborn rat model for this purpose. Methods: Sixty newborn pups were randomly separated into two groups: IEC group (n =30) orally administrated IEC during suckling, while the CON group received orally the same dose of saline. Both of the two group challenged with various doses of S.Typhimurium after experiencing a 4-week resting period. Twelve of individuals were selected to detect the survival rate, and ten of the rest were necropsied 48 hours post-challenge. Results and Discussion: The results showed that oral administration of IEC during suckling alleviated the injury in ileal morphology induced by post-weaning S.Typhimurium infection via increasing the levels of two tight junction proteins [zonula occluden-1 (ZO-1) and Occludin-1] and several secreted proteins (Lysozyme, Mucin-2, and SIgA) in the intestinal mucosa. Furthermore, the pre-stimulation with IEC significantly increased cytokines tumor necrosis factor-alpha (TNF- α) and interleukin-1 beta (IL-1 ß) expressions in an enhanced secondary reaction way after experiencing a 4-week resting period. This implicated the possible involvement of trained immunity. The 16S rDNA sequence results showed that pre-stimulation with IEC decreased the abundance of Clostridia, Prevotella, Christensenellaceae_R-7_group and Parabacteroides after intestinal infection of S.Typhimurium. Our results confirmed that the previous oral administration of IEC had a protective effect on S.Typhimurium-induced intestinal injury in weaned rats by inducing a robust immune response. The present study suggested a new strategy for preventing intestinal infection of newborn animals.

Two temperature-induced 1D CuII chain enantiomeric pairs showing different magnetic properties and nonlinear optical responses.

At different reaction temperatures, using Cu(NO3)2·3H2O to react with enantiomerically pure N-donor ligands (LS/LR), respectively, two pairs of chiral one-dimensional (1D) CuII chain enantiomers formulated as [Cu(µ2-NO3)(NO3)(LS)]n/[Cu(µ2-NO3)(NO3)(LR)]n (S-1-Cu/R-1-Cu, formed at 40 °C with an NO3- group as a sole bridging ligand) and [Cu(µ2-LS)(NO3)2]n/[Cu(µ2-LR)(NO3)2]n (S-2-Cu/R-2-Cu, formed at 25 °C with LS or LR as a bridging ligand) were prepared, where LS/LR = (+)/(-)-4,5-pinenepyridyl-2-pyrazine. Interestingly, such a disparity in bridging ligands leads not only to their distinct structural features but also to their completely different magnetic couplings together with a large difference in their nonlinear optical responses. S-1-Cu with a 1D helical structure shows weak ferromagnetic coupling between CuII ions, while S-2-Cu with a 1D stairway-like structure presents weak antiferromagnetic coupling. In particular, they simultaneously possess both second- and third-harmonic generation (SHG and THG) responses in one molecule with large strength differences. More remarkably, S-1-Cu exhibits a very large THG response (162 × α-SiO2), which is 22.5 times that of S-2-Cu, and the SHG strength of S-1-Cu is more than 3 times that of S-2-Cu. This work demonstrates that reaction temperature has a great impact on the self-assembled structures of coordination polymers and subsequently results in their large performance differences.

Two Chiral YbIII Enantiomeric Pairs with Distinct Enantiomerically Pure N-Donor Ligands Presenting Significant Differences in Photoluminescence, Circularly Polarized Luminescence, and Second-Harmonic Generation.

Using enantiomerically pure bidentate and tridentate N-donor ligands (1LR/1LS and 2LR/2LS) to replace two coordinated H2O molecules of Yb(tta)3(H2O)2, respectively, two eight- and nine-coordinated YbIII enantiomeric pairs, namely, Yb(tta)31LR/Yb(tta)31LS (Yb-R-1/Yb-S-1) and [Yb(tta)32LR]·CH3CN/[Yb(tta)32LS]·CH3CN (Yb-R-2/Yb-S-2), were isolated, in which Htta = 2-thenoyltrifluoroacetone, 1LR/1LS = (-)/(+)-4,5-pinene-2,2'-bipyridine, and 2LR/2LS = (-)/(+)-2,6-bis(4',5'-pinene-2'-pyridyl)pyridine. Interestingly, they not only present distinct degrees of chirality but also show large differences in near-infrared (NIR) photoluminescence (PL), circularly polarized luminescence (CPL), and second-harmonic generation (SHG). Eight-coordinated Yb-R-1 with an asymmetric bidentate 1LR ligand has a high NIR-PL quantum yield (1.26%) and a long decay lifetime (20 µs) at room temperature, being more than two times those (0.48%, 8 µs) of nine-coordinated Yb-R-2 with a C2-symmetric tridentate 2LR ligand. In addition, Yb-R-1 displays an efficient CPL with a luminescence dissymmetry factor glum = 0.077, being 4 × Yb-R-2 (0.018). In particular, Yb-R-1 presents a strong SHG response (0.8 × KDP), which is 8 × Yb-R-2 (0.1 × KDP). More remarkably, the precursor Yb(tta)3(H2O)2 exhibits a strong third-harmonic generation (THG) response (41 × α-SiO2), while the introduction of chiral N-donors results in the switching of THG to SHG. Our interesting findings provide new insights into both the functional regulation and switching in multifunctional lanthanide molecular materials.

Boosting Hydrogen Evolution Reaction Activity of Amorphous Molybdenum Sulfide Under High Currents Via Preferential Electron Filling Induced by Tungsten Doping.

The lack of highly efficient, durable, and cost-effective electrocatalysts for the hydrogen evolution reaction (HER) working at high current densities poses a significant challenge for the large-scale implementation of hydrogen production from renewable energy. Herein, amorphous molybdenum tungsten sulfide/nitrogen-doped reduced graphene oxide nanocomposites (a-MoWSx /N-RGO) are synthesized by plasma treatment for use as high-performance HER catalysts. By adjusting the plasma treatment duration and chemical composition, an optimal a-MoWSx /N-RGO catalyst is obtained, which exhibits a low overpotential of 348 mV at a current density of 1000 mA cm-2 and almost no decay after 24 h of working at this current density, outperforming commercial platinum/carbon (Pt/C) and previously reported heteroatom-doped MoS2 -based catalysts. Based on density functional theory (DFT) calculations, it is found that with a reasonable tungsten doping level, the catalytic active site (2S2 - ) shows excellent catalytic performance working at high current densities because extra electrons preferentially fill at 2S2 - . The introduction of tungsten tends to lower the electronic structure energy, resulting in a closer-to-zero positive Δ G H ∗ $\Delta {G}_{{{\rm{H}}}^{\rm{*}}}$ . Excessive tungsten introduction, however, can lead to structural damage and a worse HER performance under high current densities. The work provides a route towards rationally designing high-performance catalysts for the HER at industrial-level currents using earth-abundant elements.

Integrative Analysis of Metabolome and Transcriptome Reveals the Mechanism of Flavonoid Biosynthesis in Lithocarpus polystachyus Rehd.

Lithocarpus polystachyus Rehd has received great attention because of its pharmacological activities, such as inhibiting oxidation and lowering blood glucose and blood pressure, and flavonoids are one of its main pharmacodynamic components. It is important to understand the mechanisms of the flavonoid biosynthetic pathway of L. polystachyus, but the regulation of flavonoid biosynthesis is still unclear. In this study, differentially expressed genes and differentially accumulated metabolites in L. polystachyus were studied by integrating transcriptomics and metabolomics technologies. We confirmed the key genes involved in the flavonoid biosynthesis of L. polystachyus, including LpPAL3, LpCHS1, LpCHS2, LpCHI2, and LpF3H, which had consistent expression patterns with their upstream and downstream metabolites, and there is a significantly positive correlation between them. Compared to mature leaves, stems and young leaves are higher in the expression levels of key structural genes. We deduced that the MYB and bHLH transcription factors regulated the biosynthesis of different flavonoid metabolites and their regulatory patterns. Among them, LpMYB2, LpMYB20, LpMYB54, LpMYB12, and LpWD40-113 positively regulated the biosynthesis of flavones and flavanones. This discovery preliminarily revealed the pathways and key genes of flavonoid biosynthesis in L. polystachyus, which provided a reference for further study on flavonoid biosynthesis.

Metabolome and transcriptome analysis of eleutheroside B biosynthesis pathway in Eleutherococcus senticosus.

Eleutheroside B (syringin) is a medicinal active ingredient extracted from Eleutherococcus senticosus (Ruper. et Maxim.) Maxim with high clinical application value. However, its synthesis pathway remains unknown. Here, we analyzed the eleutheroside B biosynthesis pathway in E. senticosus. Consequently, metabolomic and transcriptomic analyses identified 461 differentially expressed genes (DEGs) and 425 metabolites. Further, we identified 7 DEGs and 67 metabolites involved in the eleutheroside B biosynthetic pathway in the eleutheroside B high and low plants. The correlation between the gene and metabolites was explored using the pearson correlation coefficient (PCC) analysis. Caffeoyl-CoA O-methyltransferase, caffeic acid-O-methyltransferase, ß-amyrin synthase (ß-AS) genes, NAC5, and HB5 transcription factors were identified as candidate genes and transcription factors related to the eleutheroside B synthesis. Eleutheroside B content was the highest at the young stage of the leaves both in the high and low eleutheroside B plants. Quantitative real-time polymerase chain reaction revealed that phenylalanine ammonia-lyase1, cinnamate 4-hydroxylase, ß-AS, and leucoanthocyanidin reductase gene had higher expression levels at the young stage of the leaves in the low eleutheroside B plants but lower expression levels in the high eleutheroside B plants. In the present study, we complemented the eleutheroside B biosynthetic pathway by analyzing the expression levels of relevant genes and metabolite accumulation patterns.

Integrative analysis of transcriptome and metabolome reveals the effect of DNA methylation of chalcone isomerase gene in promoter region on Lithocarpus polystachyus Rehd flavonoids.

Metabolite biosynthesis is regulated by gene expression, which is altered by DNA methylation in the promoter region. Chalcone isomerase (CHI) gene encodes a key enzyme in the Lithocarpus polystachyus Rehd flavonoid pathway, and the expression of L. polystachyus CHI (LpCHI) is closely related to the synthesis of flavonoid metabolites. In this study, we analyzed the DNA methylation site of the LpCHI promoter and its effect on gene expression and metabolite accumulation. The proportions of three types of LpCHI promoter DNA methylation are 7.5%, 68.75%, 18.75%, determined by bisulfite sequencing. Transcriptome sequencing shows that LpCHI is strongly up-regulated in LpCHI promoter methylation Type A but down-regulated in LpCHI promoter methylation Type B and Type C. The expression of LpCHI shows no significant difference between Type B and Type C. Moreover, nine kinds of differentially expressed transcription factors (DETFs) bind to seven CpG-sites of the LpCHI promoter region to regulate LpCHI expression. The results of metabolomics show that differentially accumulated flavonoids are higher in LpCHI promoter methylation Type A than in LpCHI promoter methylation Type B and Type C. Additionally, a positive correlation was found between the LpCHI expression and flavonoids accumulation. These results show that the effect of CpG site-specificity on gene transcription is great than that of overall promoter DNA methylation on gene transcription. The mechanisms of flavonoid genes regulating metabolite accumulation are further revealed.

Modulating Two Pairs of Chiral DyIII Enantiomers by Distinct ß-Diketone Ligands to Show Giant Differences in Single-Ion Magnet Performance and Nonlinear Optical Response.

Using Dy(dbm)3(H2O) and Dy(btfa)3(H2O)2 to react with enantiopure N-donors, (-)/(+)-4,5-pinenepyridyl-2-pyrazine (LR/LS), respectively, two pairs of chiral DyIII enantiomers, Dy(dbm)3LR/Dy(dbm)3LS (R-1-Dy/S-1-Dy) and Dy(btfa)3LR/Dy(btfa)3LS (R-2-Dy/S-2-Dy) were obtained, wherein one of the benzene rings of dbm- (dibenzoylmethanate) in R-1-Dy/S-1-Dy is displaced by the -CF3 group of btfa- (4,4,4-trifluoro-1-phenyl-1,3-butanedionate) in R-2-Dy/S-2-Dy. Interestingly, this substitution results not only in giant differences in their single-ion magnetic (SIM) performances but also in their completely different nonlinear optical (NLO) responses. R-1-Dy presents a large effective energy barrier (Ueff = 265.47 K) under zero applied field, being more than 4 × R-2-Dy (61.40 K). The discrepancy on their magnetic performances has been further elucidated by ab initio calculations. Meanwhile, R-1-Dy/S-1-Dy display the strongest third-harmonic generation responses (35/33 × α-SiO2) among the known lanthanide NLO-active coordination compounds (CCs). On the contrary, R-2-Dy/S-2-Dy exhibit moderate second-harmonic generation responses (0.65/0.70 × KDP). These results not only give the first example of the CCs with both SMM/SIM behavior and a THG response but also provide an efficient strategy for achieving the function regulation and switch in multifunctional CCs.