查找使用阿拉丁产品的科研文献

Spectra stable deep-blue light-emitting diodes based on cryolite-like cerium(III) halides with nanosecond d-f emission

Qingxun Guo,Liang Wang,Longbo Yang,Jiashun Duan,Hainan Du,Guoqi Ji,Nian Liu,Xue Zhao,Chao Chen,Ling Xu,Liang Gao,Jiajun Luo,Jiang Tang

Next-generation wide color gamut displays require the development of efficient and toxic-free light-emitting materials meeting the crucial Rec. 2020 standard. With the rapid progress of green and red perovskite light-emitting diodes (PeLEDs), blue PeLEDs remain a central challenge because of the undesirable color coordinates and poor spectra stability. Here, we report Cs 3 CeBr x I 6− x ( x  = 0 to 6) with the cryolite-like structure and stable and tunable color coordinates from (0.17, 0.02) to (0.15, 0.04). Further encouraged by the short exciton lifetime (26.1 ns) and high photoluminescence quantum yield (~76%), we construct Cs 3 CeBr x I 6− x -based rare-earth LEDs via thermal evaporation. A seed layer strategy is conducted to improve the device’s performance. The optimal Cs 3 CeI 6 device achieves a maximum external quantum efficiency of 3.5% and a luminance of 470 cd m −2 with stable deep-blue color coordinates of (0.15, 0.04). Our work opens another avenue to achieving efficient and spectrally stable deep-blue LEDs.

Polymer composites with enhanced thermal conductivity via oriented boron nitride and alumina hybrid fillers assisted by 3-D printing

Mengjing Liu,Sun-Wai Chiang,Xiaodong Chu,Jia Li,Lin Gan,Yanbing He,Baohua Li,Feiyu Kang,Hongda Du

Herein, oriented boron nitride (BN)/alumina (Al 2 O 3 )/polydimethylsiloxane (PDMS) composites were obtained by filler orientation due to the shear-inducing effect via 3-D printing. The oriented BN platelets acted as a rapid highway for heat transfer in the matrix and resulted in a significant increase in the thermal conductivity along the orientation direction. Extra addition of spherical Al 2 O 3 enhanced the fillers networks and resulted in the dramatic growth of slurry viscosity. This, together with filler orientation induced the synergism and provided large increases in the thermal conductivity . A high orientation degree of 90.65% and in-plane thermal conductivity of 3.64 W/(m∙K) were realized in the composites with oriented 35 wt% BN and 30 wt% Al 2 O 3 hybrid fillers. We attributed the influence of filler orientation and hybrid fillers on the thermal conductivity to the decrease of thermal interface resistance of composites and proposed possible theoretical models for the thermal conductivity enhancement mechanisms.

MXene quantum dots induced Ni site d-band center self-optimization for advanced photovoltaic-driven urea-assisted water splitting

Yufeng Jiang,Shaobin Li,Li Zhang,Yang Yang,Kun Cheng,Fengbo Li,Xiaoqing Lv

Urea-assisted electrolytic water splitting for hydrogen production represents an effective contemporary strategy for generating green hydrogen. The sluggish kinetics of the anodic urea oxidation reaction (UOR) and cathodic hydrogen evolution reaction (HER) limit their practical application. The MXene quantum dots (MQDs) promote pronounced d-d orbital hybridization between Ni and Mo sites. The constructed heterostructures facilitate electron transfer and modulate charge redistribution. The extensive formation of heterostructures between numerous quantum dots and nickel molybdate results in the emergence of flower-like clusters at the tips of rod-like NiMoO 4 particles. The augmentation of the specific surface area results in the exposure of a larger quantity of active sites, which facilitates the redistribution of charge across these active sites, consequently enhancing the hydrolytic activity. The electrocatalyst exhibits remarkable performance in both the UOR and HER, achieving 1.31 V and 55 mV at 10 mA cm –2 , respectively. The catalyst for urea–assisted water electrolysis requires only 1.38 V at 10 mA cm –2 . The prepared catalyst can be employed for seawater splitting and photovoltaic-driven hydrogen production. In-situ Raman spectrum confirms that Ni sites on the NiMoO 4 /MQDs surface transform into Ni–OOH under hydrolysis and subsequently govern the hydrolytic reaction. This work indicates that d-d orbital hybridization can provide pathways for electronic transitions, thereby enhancing charge-transfer efficiency and effectively lowering reaction energy barriers.

Honokiol-Loaded β-D-Glucan/Chitosan Nanoparticles with Antibacterial and Anti-Inflammatory Activities for Promoting MRSA-Infected Wound Healing

Background:Methicillin-resistantStaphylococcus aureus(MRSA) wound infections are a major clinical concern due to their high prevalence and the growing risk of antimicrobial resistance. Therefore, it is imperative to develop safe and effective therapeutic strategies.Methods: Herein, we fabricated a novel antibiotic-free nanodrug delivery system (HNK/DG-COS NPs) by loading honokiol (HNK), a hydrophobic natural antimicrobial agent, onto a dual-polysaccharide carrier composed of chitosan (COS) and β-D-glucan (DG), for the treatment of MRSA-infected wounds. COS endows the nanoparticles with synergistic antibacterial activity together with HNK, while DG improves their anti-inflammatory and tissue repair capacities. The physicochemical characteristics of nanoparticles, as well as their in vitro antibacterial and anti-inflammatory activities, were systematically evaluated. Furthermore, an MRSA-infected wound model was constructed to verify their therapeutic efficacy.Results: HNK/DG-COS NPs exhibited a spherical morphology with a uniform particle size of approximately 200 nm. In vitro experiments have shown that HNK/DG-COS NPs can significantly kill MRSA and inhibit biofilm formation. Scanning electron microscopy further revealed that the nanoparticles exerted antibacterial effects by disrupting the integrity of bacterial cell membranes. In LPS-stimulated RAW264.7 macrophages, treatment with HNK/DG-COS NPs significantly mitigated pro-inflammatory cytokine levels. Cell migration assays confirmed that nanoparticles effectively enhanced L929 cell migration. In vivo, treatment with HNK/DG-COS NPs significantly accelerated MRSA-infected wound healing in mice, mitigated inflammatory damage, stimulated collagen production and repaired damaged tissues.Conclusions: HNK/DG-COS NPs represent a promising antibiotic-free candidate for intervention against early-stage MRSA-infected wounds.

Continuous-Flow Kinetic Analysis of TBD-Catalyzed Aminolysis of d-(−)-Pantolactone Using Flow-Rate Ramping and Inline FTIR Spectroscopy

Zhu Jianxiang,Li Jiahui,Shen Runqiu,Song Yuwei,Xie Yuanyuan,Duan Hongliang,Su An

The development of efficient and sustainable amide-bond-forming processes, together with their quantitative kinetic characterization, is of major significance to the fine chemical and pharmaceutical industries. In this study, the aminolysis of d -(−)-pantolactone (DPL) with pyrrolidine (Pyr), catalyzed by 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD), was investigated in a continuous-flow microreactor equipped with inline Fourier transform infrared (FTIR) spectroscopy. For the first time, a flow-rate-ramp transient kinetic method was applied to an organobase-catalyzed aminolysis system. A multiresponse FTIR–PLS quantitative model was developed using Latin hypercube sampling (LHS) for calibration-set design, thereby effectively reducing the collinearity inherent in conventional calibration samples distributed along the reaction stoichiometric line. An analytical mapping between experimental time and the actual residence time of fluid elements under dynamic flow conditions was established, making it possible to extract continuous kinetic data over a residence-time range of 2–40 min from just one 83.1 min flow-rate-ramp experiment. The reaction orders with respect to DPL, Pyr, and TBD were determined to be 1, 1, and 0.85, respectively, via the isolation and initial-rate methods. An explicit analytical expression for DPL conversion was derived based on a plug-flow reactor model. Arrhenius analysis yielded an activation energy of 26.26 kJ·mol –1 and a pre-exponential factor of 2.96 × 10 5 L 1.85 ·mol –1.85 ·min –1 . The resulting model demonstrated good predictive accuracy when applied to temperatures and initial concentrations outside the fitting range. This work provides a reliable kinetic basis for the design and scale-up of continuous DPL aminolysis processes and offers a rapid and resource-efficient strategy for kinetically characterizing related metal-free organocatalytic systems.

Engineering P450 Peroxygenase Overoxidation Promiscuity Enables Concise and High-Yielding Biocatalytic Synthesis of d-Amino Acids from Fatty Acids

Xing Yu,Peng Deng,Sheng Gu,Bu-Bing Zeng,Hui-Lei Yu,Jian-He Xu,Zhi-Jun Zhang

Direct asymmetric α-C−H bond amination of carboxylic acids is an attractive route to optically active α-amino acids from inexpensive, renewable starting materials. However, traditional chemical methods suffer from expensive catalysts and environmental concerns, while recently developed multienzyme cascades are limited by complex auxiliary enzyme requirements and narrow substrate scope. Here, we report an engineered P450 peroxygenase (P450CLA-M5) with enhanced overoxidation promiscuity that enables the direct conversion of fatty acids to α-keto acids. Coupling this enzyme with d-amino acid dehydrogenase and formate dehydrogenase establishes a biocatalytic cascade for the C−H amination of fatty acids to d-amino acids. Saturated, unsaturated, and aromatic fatty acids were converted to the corresponding d-amino acids with yields up to 94% and >99% ee. Specifically, the yield of d-2-aminodecanoic acid represents a 15-fold improvement over previous biocatalytic approaches. This work demonstrates how engineering increased enzyme promiscuity can enhance cascade efficiency for the synthesis of valuable chiral d-amino acids from renewable feedstocks.

Construction of Fully Biodegradable Poly(L-Lactide-Co-Caprolactone) Random Copolymer/Poly(D-Lactide) Blend: Crystallization, Toughness, and Biodegradability

Lei Gong,Yuesheng Zhang,Enyang Xu,Hongtao Lu,Junrui Duan,Jianna Bao

In this work, poly(L-lactide-co-ε-caprolactone) (PLCL) copolymers with varying ε-caprolactone (ε-CL) contents that ranged from 0% to 10% were synthesized via ring-opening polymerization of L-lactide and ε-CL at 170°C for 1 h. Fully biodegradable PLCL/poly(D-lactide) (PDLA) blends with stereocomplex (SC) crystallites were fabricated through a solution blending approach. The effects of ε-CL content in PLCL on the crystallization behavior, thermal properties, mechanical performance, and degradation behavior of PLCL/PDLA blends were systematically investigated. The successful synthesis of PLCL was confirmed by 1 H NMR and FTIR analyses. The melting peaks observed in the high-temperature region and the characteristic diffractions in WAXD patterns provided evidence for the formation of SC crystallites in PLCL/PDLA blends. Compared with PLCL, the incorporation of PDLA significantly enhanced the crystallization rate, due to the nucleation function of SC crystallites. With increasing ε-CL content in the copolymer system, the T g and crystallinity of PLCL gradually reduced, and the melting peaks of HC and SC crystals shifted toward lower temperatures due to the reduced sequence regularity. A pronounced improvement in deformability was achieved by the presence of ε-CL segments. As the ε-CL content increased from 1.5% to 10%, the elongation at break rose from 12% to 192%, with the morphology of elongated fibrils. Higher ε-CL contents accelerated enzymatic degradation, with mass loss exceeding 75% after 7 days at 10% ε-CL, because the increased chain mobility may facilitate the penetration of water and Proteinase K into the blend, thereby promoting enzymatic erosion. Overall, high-performance PLA-based composites with excellent biodegradability were achieved via SC crystallization and modulation of ε-CL comonomer content. Summary PLCL copolymers with tunable ε-CL content were prepared and characterized. SC crystallization regulated the crystallization and thermal behavior. ε-CL segments enhance chain mobility and improve blend deformability. Enzymatic degradation kinetics were accelerated as ε-CL content increased.

Tuning the d-Band center of High-Entropy oxides for selective aromatic oxidation and viscosity reduction in heavy oil

Lian Chen,Zhaofei Ma,Yu Jiang,Yuanzhu Mi,Yancheng Zheng,Xuemin Yan

Despite abundant global reserves, the industrial utilization of heavy oil is severely limited by its extremely high viscosity, primarily caused by the aggregation of polycyclic aromatic hydrocarbons (PAHs). In this study, we propose a novel viscosity reduction strategy using spinel-structured high-entropy oxides (HEOs) as low-temperature catalysts requiring no additional oxidants, representing a significant departure from conventional thermal and oxidative methods. By tuning the d-band centers of multicomponent metal sites, the electronic structure of HEOs is optimized to selectively activate and moderately oxidize aromatic-rich asphaltenes. This catalytic process disrupts π–π stacking and introduces oxygen-containing functional groups, triggering a fundamentally new, irreversible viscosity reduction mechanism driven by molecular fragmentation and polarity modulation. Experimental validations, including rheological measurements, spectroscopic analysis, and model compound studies, reveal a substantial viscosity reduction of ∼ 75.05%. Mechanistically, the partial oxidation of asphaltenes promotes molecular disorder, releases trapped light components from the condensed matrix, and facilitates the penetration of surfactants, thereby lowering the oil–water interfacial tension. Overall, this work establishes HEOs as a next-generation catalytic platform and presents a new pathway for efficient and sustainable heavy oil mobility enhancement.

Ophiopogonin D reprograms the polarization of macrophages through modulating PPM1K-mediated branched-chain amino acids catabolism to delay atherogenesis

Shangmin Yu,Jiaqi Liu,Shan Liu

Background Atherosclerosis (AS) is a chronic inflammatory vascular disease. Macrophage reprogramming plays a crucial role in the progression of AS. Ophiopogonin D (OP-D), a bioactive constituent of Ophiopogon japonicus , has exhibited potent anti-atherosclerotic property. However, whether OP-D exerts its atheroprotective effect via reprogramming macrophage remains unclear. This study aimed to investigate the effect of OP-D on AS and elucidate its underlying mechanism. Methods The atheroprotective effect of OP-D on atherosclerotic mice was evaluated by histological and molecular assays. The crucial role of macrophage in OP-D's atheroprotective effect was detected by flow cytometry and verified through macrophage depletion/infusion. The direct effect of OP-D on macrophages were assessed in vitro by RT-qPCR, flow cytometry, and immunofluorescence. RNA sequencing and amino acid-targeted metabolomics analysis were employed to identify the associated amino acid metabolic pathways. In addition, PPM1K deficient was established to validate the role of branched-chain amino acids (BCAAs) in macrophage reprogramming and OP-D's therapeutic effect. Results Our results demonstrated that OP-D attenuated the progression of AS and directly prevented the M1-like polarization of macrophages. Meanwhile, the therapeutic benefits of OP-D were abolished after macrophages depletion, suggesting macrophage was a crucial mediator of OP-D's therapeutic effect. Further mechanistic studies revealed that dysregulated BCAAs metabolism-mediated macrophage polarization underlay the anti-atherosclerotic effect of OP-D. Conclusion This study elucidated that OP-D reprogrammed the polarization of macrophages through modulating BCAAs catabolism to delay atherogenesis. These findings will deepen the understanding of OP-D's atheroprotective mechanisms and provide a potential therapeutic target for AS.

Chiisanoside Ameliorates d-Galactose-Induced Age-Related Hearing Loss by Modulating Autophagy and Ferroptosis via the SESN2/AMPK Axis

Wang Haijing,Gao Jie,Bai Xuefei,Liu Xiaofeng,Qu Shurong,Gao Yugang,Zhao Yan,Teng Hongbo

Age-related hearing loss (ARHL) is a pervasive sensorineural deficit lacking effective pharmacological interventions. Although Eleutherococcus senticosus fruit extracts exhibit otoprotective potential, their precise bioactive constituents and underlying molecular mechanisms remain elusive. Using network pharmacology and transcriptomic analysis as hypothesis-generating tools, followed by experimental validation, this study identifies chiisanoside (CSS) as a key bioactive compound mitigating d -galactose-induced cellular senescence and auditory impairment, with an optimal effective dose of 25 μM in vitro (HEI-OC1 cells) and 50 mg/kg/day in vivo (oral gavage in C57BL/6 mice). Mechanistically, the in vitro and in vivo models demonstrate that CSS suppresses age-related auditory decline primarily by targeting the SESN2/AMPK signaling axis. Specifically, CSS upregulates SESN2 to activate AMPK, which not only enhances autophagy via the mTOR/ULK1 pathway but also concurrently inhibits the HIF-1α/TFRC/FTH1 cascade. These findings provide mechanistic insights supporting the potential of CSS as a therapeutic candidate in ARHL.

Gold nanoparticles with surface-anchored chiral poly(acryloyl-L(D)-valine) induce differential response on mesenchymal stem cell osteogenesis

Deng Jun,Zheng Honghao,Zheng Xiaowen,Yao Mengyun,Li Zheng,Gao Changyou

Chirality is one of the most distinctive biochemical signatures of life, and plays crucial roles in maintaining normal functions of living cells or organisms. Pioneering work from another group has demonstrated the dependency of cell differentiation on the chirality of nano-coated substrates, but the effect of the chiral surface of nanoparticles on stem cell fates has not been investigated. In this study, the influence of molecular chiral poly(acryloyl-L(D)-valine) (L(D)- PAV)-anchored gold nanoparticles (L(D)-PAV-AuNPs) on the differentiation of mesenchymal stem cells (MSCs) was investigated. Though osteogenic differentiation of MSCs was not affected by D-PAV-AuNPs, it was significantly promoted by L-PAV-AuNPs in terms of calcium deposition, alkaline phosphatase (ALP) activity, and expression of collagen type I and osteocalcin (OCN) at both mRNA and protein levels. L-PAV-AuNPs could activate the P38 mitogen-activated protein kinase (MAPK) pathway, and may exert mechanical stress on MSCs because of high amounts of internalization. These results provide new insights on surface chirality at the nanoscale as a direct regulator to guide the differentiation of MSCs, and the use of these nanomaterials for strategic regenerative medicine.

D-serine Ameliorates Motor and Cognitive Impairments in β-amyloid 1-42 Injected Mice by Inhibiting JNK Signaling Pathway

Hongqing Liu,Shiqi Li,Cuizhu Yang,Hui Jia,Ziting Gu,Xing Tu,Sumin Tian,Jing Liu,Guoying Li,Yuxin Ma

The senile plaque formed by β-amyloid (Aβ) deposition in the brain is one of the main pathological features of Alzheimer’s disease (AD), and the c-Jun N-terminal kinase (JNK) signaling pathway plays an important role in the pathogenesis of AD. This study aimed to investigate that D-serine may ameliorate motor and cognitive impairment in Aβ injected mice by inhibiting JNK signaling pathway. Firstly, Kunming mice were injected intrahippocampally with Aβ 1-42 to build AD model. The mice were injected intraperitoneally with saline, D-serine, D-amino acid oxidase (DAAO), and Sodium benzoate (BE) for 10 consecutive days, respectively. Subsequently, the motor and cognitive functions of mice were detected by behavioral tests. The silver staining and immunohistochemical methods were used to detect the distributions of Aβ in the hippocampus of mice. 18 F-2-Fluro-D-deoxy-glucose positron emission tomography/computed tomography ( 18 F-FDG PET/CT) scans were performed to detected glucose metabolism of Aβ 1-42 induced lesions. The expressions of relative JNK factors were detected by immunohistochemistry and Western blot methods. These results showed that Aβ severely impaired the motor and memory abilities of mice. The expressions of glial fibrillary acidic protein (GFAP), tumor necrosis factor (TNF-α), N-methyl-D-aspartate receptor 1 (NMDAR1), phospho-JNK (p-JNK), p-c-Jun and activating transcription factor 2 (ATF2) increased significantly. After D-serine treatment, the abilities of movement and memory of mice were improved, and the clearance rate of Aβ was accelerated. The expressions of GFAP, TNF-α, NMDAR1, p-JNK, p-c-Jun and ATF2 decreased significantly. DAAO and BE were administered to further validate these results. Therefore, this study showed that D-serine could alleviate the cognitive impairment of Aβ 1-42 injected mice by inhibiting JNK signaling pathway. These results provide more evidences for the effect of D-serine on AD and relevant mechanism to treat AD.