查找使用阿拉丁产品的科研文献

Efficient removal of boron acid by N-methyl-d-glucamine functionalized silica–polyallylamine composites and its adsorption mechanism

Xin Li,Ru Liu,Shan Wu,Jiong Liu,Shushan Cai,Dongsheng Chen

A novel boron adsorbent was fabricated by grafting a boric acid chelating group, i.e., N-methyl- d -glucamine, onto the hydrophilic silica–polyallylamine composites (SPC). The boron adsorbent was characterized by scanning electron microscopy (SEM) and TGA method. The adsorption experiment indicated a maximum boron load capacity of ca. 1.55   mmol   g −1 . The high load capacity was attributed to specific chemical affinity and physical adsorption. Highly effective removal of boric acid from aqueous solution was observed for the adsorbent even in the synthetic seawater containing high concentration of foreign ions. Analysis of adsorption thermodynamic and kinetics revealed a spontaneous sorption process that is driven by enthalpy change and limited by chemical reaction. The exhausted adsorbent was regenerated for repeated use by treating with 3% HCl solution, followed by neutralizing with 3% NH 3 ·H 2 O at ambient temperature. Only 7% capacity loss was observed after five continuous adsorption–regeneration cycles.

Development of a pair of differential H/D isotope-coded derivatization reagents d0/d3-4-(1-methyl-1H-phenanthro[9,10-d]imidazol-2-yl)phenlamine and its application for determination of aldehydes in selected aquatic products by liquid chromatography–tandem mass spectrometry

Zhiwei Sun,Xiaoxiang Wang,Yiping Cai,Junqing Fu,Jinmao You

A new pair of derivatization reagents, d 0 -4-(1-methyl-1 H -phenanthro[9,10- d ]imidazol-2-yl)phenlamine (d 0 -MPIA) and d 3 -4-(1-methyl-1 H -phenanthro[9,10- d ]imidazol-2-yl)phenlamine (d 3 -MPIA) have been designed and synthesized. It was successfully used to label aliphatic aldehydes and the aldehyde derivatives were analyzed by high-performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS). The new isotope-coded reagents could easily label aldehydes under acidic conditions in the presence of NaCNBH 3 . The target derivatives exhibited intense [M+H] + and regular product ions with electrospray ionization source in positive mode. The d 0 /d 3 -MPIA-aldehydes were monitored by the transitions of [M+H] + → m/z 322 and [M+H] + → m/z 165, and the obtained detection limits were in the range of 0.18–15.9   pg/mL at signal to noise ratio of 3. The global isotope internal standard technology was employed for quantification analysis with d 3 -MPIA-aldehyde as internal standard for corresponding d 0 -MPIA-aldehyde. Excellent linear responses for relative quantification were observed in the range of 1/10–10/1 with coefficients >0.998. The developed method has been applied to the quantification of aliphatic aldehydes in selected aquatic products with RSD<3.6% and recoveries >85.2%.

Enhanced CO2 hydrate formation via biopromoter coupled with initial stirring activation

Yongtao Zhang,Fulin Chen,Yan He,Fei Wang

CO 2 sequestration based on hydrate technology is considered to be the most promising long-term CO 2 sequestration technology. In this study, a method of using initial stirring to activate CO 2 hydrate formation process was proposed in the aim of saving energy and avoiding the problem of stirring shaft stuck, where the stirring only played a role in activating hydrate formation process. Two amino acids, l -Methionine and d -leucine, were chosen as promoters for improving the formation kinetics of CO 2 hydrates, and l -Methionine presents better than d -leucine. When the concentration of l -methionine solution is equal to or greater than 4 mmol/L, even with the initial stirring of 10 rpm within 8 min, T 90 can be shortened to close to or less than 40 min with a high gas consumption of more than 7.3 mmol gas/mL water, where the promoting effect is similar to the condition of continuous stirring of about 100 min, indicating that about 90 % of the energy consumed for mechanical stirring can be saved. Moreover, an interesting phenomenon was observed that CO 2 hydrates firstly nucleated inside the l -methionine solution, and a large number of small hydrate floccules rapidly formed and filled the entire solution under the action of magnetic stirring, which proved the instantaneous excitation effect of stirring on hydrate formation. This work contributes to rethinking the promoting roles of stirring and promoters in CO 2 hydrate formation.

Phosphorus-induced d-p orbital hybridization in PtFeCoCuMo alloys: Regulating active hydrogen supply to enhance alkaline hydrogen evolution reaction

Zixuan Deng,Shuang Zhang,Fudong Li,Yue Zhu,Changsheng Shan,Yuanmeng Zhao

Rationally designing electrocatalyst/electrolyte interfaces with excellent active hydrogen supply capability is crucial for the hydrogen evolution reaction (HER), a core step in alkaline anion exchange membrane water electrolysis (AEMWE). Herein, phosphorus (P)-surface-coordinated PtFeCoCuMo quinary alloys are synthesized via a two-step wet-chemical method. P-induced d-p orbital hybridization enables the synergistic regulation of two key factors: it optimizes the hydrogen adsorption free energy (ΔG H∗ ) and water dissociation barrier (thermodynamic modulation), while tailoring the potential of zero charge (PZC) to accelerate proton transport (kinetic modulation). The optimized P 16 -PtFeCoCuMo catalyst exhibits outstanding alkaline HER activity, with a turnover frequency (TOF) 5-fold and 3-fold higher than those of commercial Pt/C and pristine PtFeCoCuMo alloy, respectively. This work overcomes thermodynamic and kinetic limitations simultaneously through heteroatom doping, providing a promising strategy for the design of high-performance alkaline HER catalysts.

Hyaluronic acid-ethylenediamine-cinnamic acid attenuates IBS-D via regulating 5-hydroxytryptamine signaling pathway, intestinal barrier and gut microbiota

Li Cui,Rongling Zhong,Wanqiu Peng,Zhenhai Zhang,Zhentao An,Hui Li

Current clinical management of diarrhea-predominant irritable bowel syndrome (IBS-D) faces substantial challenges due to the limited efficacy of existing therapeutic strategies. This study aimed to synthesize and characterize the hyaluronic acid-ethylenediamine-cinnamic acid conjugate (HA-EDA-CA), investigate its oral bioavailability and colonic tissue distribution, and validate its therapeutic potential along with underlying mechanisms of action in IBS-D models. Following oral administration of free CA or HA-EDA-CA, the colon concentration of CA released from the derivative was significantly higher than that of free CA alone. Both free and conjugated forms of CA likely contributed to the therapeutic effects against IBS-D. The IBS-D model was established by a combination of senna decoction administration and physical restraint stress. After HA-EDA-CA intervention, IBS-D model mice showed marked improvements in stool consistency, fecal water content, stool output, body weight, visceral hypersensitivity, and colon length. ELISA results indicated significant reduction in enteric neurotransmitter levels, including 5-hydroxytryptamine, substance P, and vasoactive intestinal peptide, after oral gavage administration of HA-EDA-CA. Additionally, intestinal permeability assessment and immunofluorescence analyse revealed that HA-EDA-CA improved intestinal barrier function. Western blot analysis indicated HA-EDA-CA inhibited 5-hydroxytryptamine signaling pathway. Furthermore, HA-EDA-CA modulated gut microbiota composition. These findings suggested the potential of HA-EDA-CA as a promising therapeutic candidate for IBS-D treatment. Key novelties: (i) First colon-targeted CA-HA conjugate: We developed and characterized the first hyaluronic acid-based conjugate specifically designed for colon-targeted delivery of cinnamic acid. (ii) Multi-mechanism rescue: The conjugate simultaneously restores gut homeostasis by modulating the 5-hydroxytryptamine signaling pathway, enhancing intestinal barrier function, and rebalancing gut microbiota. (iii) Enhanced therapeutic efficacy: HA-EDA-CA demonstrates superior colonic drug accumulation and integrated therapeutic outcomes compared to free cinnamic acid or simple drug mixtures. (iv) Open-source data availability: All relevant data and analysis scripts supporting the findings are publicly accessible to ensure reproducibility and further research.

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.