查找使用阿拉丁产品的科研文献

Constructing heterostructure by co-doping of Ta5+ and F− with carbon nanotubes to improve kinetic properties of Na3V2(PO4)3

Tao Zhou,Yanjun Chen

The advancement of Na 3 V 2 (PO 4 ) 3 has been impeded by its subpar kinetic characteristics, resulting in suboptimal electrochemical performance . In this case, a dual modification strategy involving Ta and F co-doping is employed, along with the incorporation of carbon nanotubes (CNTs), is introduced. Notably, the substitution of high-valence Ta 5+ for V 3+ ions induces an n-type doping effect, thereby increasing the density of free electrons and enhancing electrochemical performance. Moreover, Ta 5+ possesses a comparatively larger ionic radius than V 3+ , which enhances the ease of Na + transport, leading to an increased rate of ionic diffusion. Furthermore, Ta 5+ ions play a crucial role in reinforcing the crystal structure, thereby strengthening the stability of the NVP system. Importantly, during the high-temperature calcination process, the reduction of carbon results in the conversion of Ta 5+ to Ta 3+ , forming a novel conductive TaN phase through its reaction with N 2 . This TaN phase, known for its high conductivity, intercalates into the NVP bulk as interlayers, forming beneficial grain boundaries. Thanks to this unique TaN//NVP heterojunction , the migration of Na + ions is notably accelerated along the grain boundaries rather than within the NVP bulk. The introduction of F contributes to reducing the grain size of active particles, consequently shortening the pathways for Na + migration and improving kinetic properties. Moreover, the presence of carbon layers and the encapsulation of CNTs collaboratively construct a highly conductive cross-linking network, elevating both electronic conductivity and mitigating NVP particle aggregation during high-temperature sintering. Consequently, the modified NVTPF0.07/@CNTs sample exhibits outstanding performance in both half and full cells, underscoring its substantial potential for application in the field of sodium-ion batteries.

Highly effective Ru/CMK-3 catalyst for selective reduction of nitrobenzene derivatives with H2O as solvent at near ambient temperature

Jun Hu,Yue Ding,Haidong Zhang,Peng Wu,Xiaohong Li

At near ambient temperature, Ru nanoparticles entrapped in ordered mesoporous carbons (OMCs) CMK-3 show superior efficiency in the green reduction process of nitrobenzene and its derivatives with hydrazine monohydrate as a hydrogen donor using water as solvent. The Ru/CMK-3 catalyst exhibited much higher activity than a commercial Ru/C catalyst purchased from Alfa Aesar toward the reduction of nitrobenzene with hydrazine monohydrate under the same conditions. The interaction of Ru nanoparticles with CMK-3 and the mesoporous structure of CMK-3 OMCs might play important roles in determining the catalytic performance of the Ru/CMK-3 catalyst. In addition, the catalytic performance of the Ru/CMK-3 catalyst for the reduction of nitrobenzene was also compared using different hydrogen sources. Hydrazine monohydrate was found to be suitable as a hydrogen donor for the reduction of nitrobenzene and its derivatives. Compared with those obtained in the reduction of nitrobenzenes using 4.0 MPa hydrogen, the catalytic activity of the Ru/CMK-3 catalyst obtained using hydrazine monohydrate as hydrogen donor was much higher in most cases.

The early Cambrian (Series 2, Stage 3) burrows from the Nagaur Sandstone, Marwar Supergroup, Rajasthan, India: palaeoenvironmental and palaeoecological considerations

Shamim Ahmad,S. K. Pandey,Mukund Sharma,Ayushi Srivastava

Deciphering the cooperative mechanisms of La doping, temperature, and pressure in NaNbO $$_{3}$$ ceramics: a multi-stimuli Raman spectroscopic study

Jiang Bo,Zhang Zheting,Yu Hang,Dai Kai,Jiang Kai

NaNbO \(_{3}\) , as a typical lead-free perovskite ferroelectric, holds great potential for energy storage and electromechanical applications, whereas the synergistic regulation of lattice dynamics by La doping, temperature, and pressure remains poorly understood. Here, we systematically investigate La \(^{3+}\) -doped NaNbO \(_{3}\) ceramics via Rietveld refinement and multi-stimuli Raman spectroscopy. La \(^{3+}\) substitution induces lattice distortion and oxygen vacancies, driving a structural transition from an ordered orthorhombic ferroelectric phase to a disordered ergodic relaxor state, where \(\textit{x}\) = 0.08 serves as a metastable boundary with maximal lattice disorder and superior external-field sensitivity. Temperature-dependent Raman results reveal a successive \(\textrm{NR} \rightarrow \textrm{ER} \rightarrow \textrm{SPE}\) structural evolution, while variable-pressure Raman identifies a unique B-site order–disorder–reorder transition, with the \(\textit{x}\) = 0.08 composition exhibiting distinctive two-stage softening–hardening behavior. The established temperature–composition phase diagram enables systematic dielectric performance optimization, and the emergent metastable state at \(\textit{x}\) = 0.08 provides a critical structural guideline for designing high-performance lead-free ceramics for energy storage, sensing, and actuation applications.

Valorization of fish oil byproduct methyl esters for omega‑3 polyunsaturated fatty acids production via immobilized CALB lipase‑catalyzed hydrolysis

Shen Ji-Dong,Zhang Meng,Li Meng-Yang,Dong Yu-Qi,Liu Zhi-Qiang,Zheng Yu-Guo

Omega-3 polyunsaturated fatty acids (n-3 PUFAs) offer therapeutic benefits, including triglyceride reduction and management of cardiovascular and neurological disorders. This study investigates the use of fish oil processing by‑products, which consist mainly of fatty acid methyl and ethyl esters, as novel substrates for n‑3 PUFAs production. To overcome the low efficiency of conventional chemical methods and the vulnerability of free lipase to alcohol toxicity and poor reusability, we developed a stable immobilized lipase system. The target enzyme (CALB) was immobilized onto macroporous resin LXTE‑1000 via adsorption‑crosslinking, and optimal hydrolysis conditions were determined. The resulting immobilized enzyme (LXTE‑1000@CALB) showed markedly enhanced thermal and operational stability, retaining approximately 64.21% of its initial hydrolysis degree over ten consecutive batches. This work provides an efficient, green, and sustainable approach for valorizing fish oil by‑products and producing n‑3 PUFAs. Graphical abstract

High-Yield Biosynthesis of 3-Hydroxypropionic Acid from Acetate by Engineering Bicarbonate Supply and Malonyl-CoA Partitioning in Escherichia coli

Junchen He,Yuanchan Luo,Hui Wu

3-Hydroxypropionic acid (3-HP) is a versatile platform chemical with broad applications in biodegradable plastics and superabsorbent polymers. Acetate derived from waste biomass and industrial off-gases can serve as a sustainable C2 feedstock for 3-HP production. However, the efficient conversion of acetate to 3-HP remains constrained by insufficient intracellular bicarbonate supply and competition with fatty acid biosynthesis for malonyl-CoA. To address these issues, carboxylation efficiency was enhanced in E. coli by co-expressing carbonic anhydrase (CA) with sodium-dependent bicarbonate transporters (BicA) and supplementation with sodium bicarbonate. Further overexpression of fabF was used to inhibit the initiation of fatty acid biosynthesis, reducing competition for malonyl-CoA. The engineered strain achieved a 3-HP yield of 0.73 g/g in shake flask culture, approaching the theoretical maximum without chemical inhibitors. In a fed-batch bioreactor, the 3-HP titer reached 20.55 g/L with a yield of 0.56 g/g (0.37 mol/mol), corresponding to 74.67% of the theoretical maximum yield. This bioprocess enables efficient valorization of sustainable C2 feedstocks, offering a promising pathway for the industrial production of bio-based platform chemicals.

Density, Viscosity, Thermodynamic and Excess Properties, and Intermolecular Interactions of a 1,3-Butanediol + 3-Diethylaminopropylamine Binary System for CO2 Absorption

Xuewei Lang,Yuchang Wang,Jiaqi Zang,Xiyue Ma,Zhengtong Zhu,Feng Wei,Yun Li,Jianbin Zhang

Density and viscosity of a 1,3-butanediol (1,3-BDO) and 3-diethylaminopropylamine (DEAPA) binary system with various molar ratios were measured at atmospheric pressure and a temperature range from 298.15 to 318.15 K. Based on density and viscosity data, the relationship between the system’s density and temperature/composition was studied using the Jouyban–Acree model and nonlinear least-squares. To discuss the connection between the viscosity and molar fraction, the McAllister three-body model, the McAllister four-body model, the Eyring–Margules viscosity model, and the Heric viscosity model were used. The dependence of viscosity on temperature is characterized by the Arrhenius equation. Furthermore, the excess properties (excess molar volume, viscosity deviation, and excess activation Gibbs free energy) of the binary system were fitted using the Redlich–Kister equation. Activation thermodynamic properties (Gibbs free energy, enthalpy, and entropy) of the binary system were calculated. As demonstrated by findings from Raman spectroscopy, nuclear magnetic resonance spectroscopy, fluorescence spectroscopy, and density functional theory calculation, further evidence confirms intermolecular hydrogen bonds in the binary system in the form of –OH···N(H2)–. Finally, the CO2 absorption capacities of the pure components and binary system were measured separately, indicating that adding 1,3-BDO to DEAPA significantly enhances CO2 uptake and provides a promising method for CO2 capture.

Direct recovery of low-concentration Au(S2O3) 2 3− from pregnant leach solution using an activated carbon-coated titanium electrode

Zeng Yong,Che Xiyuan,Zhang Lei,Chen Peng,Song Shaoxian,Wang Deshou,Jia Feifei

Thiosulfate gold extraction technology has gained considerable interest owing to its environmental compatibility and broad applicability to diverse ore types. However, the lack of efficient methods to recover Au(S 2 O 3 ) 3− 2 from leaching solutions has hindered its industrial implementation. To address this challenge, this study used a thiosulfate leaching solution from quartz-type gold ores to design an activated carbon-coated titanium electrode (Ti@AC) with a porous surface structure. This electrode facilitated the direct reduction of low-concentration Au(S 2 O 3 ) 3− 2 to metallic gold (Au 0 ) in solution, achieving a gold recovery of 99.58%, surpassing other recovery methods from the leaching solution by 30%–80%. After ten consecutive 200 L pilot-scale tests, the Ti@AC electrode demonstrated remarkable stability, consistently maintaining a recovery >98% and yielding 20.23 g of gold. The porous architecture of the activated carbon (AC) promoted the adsorption of low-concentration Au(S 2 O 3 ) 3− 2 , while its low charge transfer resistance facilitated the efficient conversion of Au(S 2 O 3 ) 3− 2 to Au 0 . Moreover, the reduction reaction generated a concentration gradient near the cathode, promoting the diffusion of Au(S 2 O 3 ) 3− 2 toward the electrode and ensuring an efficient recovery process. This study provides a feasible strategy for the direct reduction of low-concentration precious metal ions to monomers with high recovery and low costs, which is promising for industrial applications.

Regulation of myofibrillar protein gelation by epigallocatechin-3-gallate and carrageenan type: structural and conformational changes associated with gel performance

Can Luo,Yuexing Shi,Muhammad Ramzan,Handan Zhang,Dongyang Jia,Lianhong Guo,Jie Zhu

A concentration-dependent biphasic effect of EGCG on reduced-salt MP gelation was observed. • EGCG-containing MP gels at 0.3 M NaCl were better stabilized by ι-carrageenan. • S–S conformational order was reduced by κ-carrageenan at high EGCG addition. • Raman-derived S–S orderliness was closely associated with gel strength. • EGCG functionality in reduced-salt MP gels was redirected by carrageenan type. Epigallocatechin-3-gallate (EGCG) interacts with muscle proteins, but its concentration-dependent effects on reduced-salt myofibrillar protein (MP) gels and their modulation by carrageenan type remain unclear. This study investigated the effects of κ- and ι-carrageenan on the gelation, cooking loss, molecular structure, and structure–function relationships of MP gels containing 0, 2.5, 5, or 10 μmol/g EGCG. In carrageenan-free MP gels, EGCG exhibited a biphasic effect on gel strength, which peaked at 5 μmol/g (57.13 g mm) but declined at 10 μmol/g (32.61 g mm), accompanied by increased cooking loss (65.84%). Carrageenan type distinctly reshaped this response. Compared with κ-carrageenan, ι-carrageenan showed better compatibility with EGCG-containing MP gels, resulting in lower cooking loss at 10 μmol/g EGCG (59.20% vs. 65.91%) and improved network continuity. Raman and FTIR analyses showed that ι-carrageenan-containing gels exhibited a higher disulfide conformational orderliness index (0.85), together with coordinated amide-region changes including a β-sheet content of 38.8%, whereas κ-carrageenan-containing gels showed lower disulfide orderliness (0.41) and higher cooking loss. Regression analysis identified S–S conformational orderliness as the strongest predictor of gel strength (R 2  = 0.91). These findings indicate that carrageenan does not simply act as a universal gel enhancer in reduced-salt MP systems, but modulates EGCG functionality in a type-dependent manner. This work provides insight into designing reduced-salt meat protein gels using polyphenol–polysaccharide combinations. Carrageenan type directs EGCG modulation of reduced-salt myofibrillar protein gels. Download: Download high-res image (537KB) Download: Download full-size image

Robust artificial interface combining AlF3 coating with carbon layer stimulates stable long lifespan for Na2TiV(PO4)3 in sodium storage

Xinbo Li,Qinghao Cao,Junyang Chen,Chuanpu Zhang,Qiang Ru

Dual-layer artificial interface of carbon/AlF 3 enhances conductivity and Na + transport, suppressing structural degradation. • NTVP@C/AF-1%: 184.58mAh g −1 at 0.1C, 93.66% capacity retention after 2500 cycles at 20C. • NTVP@C/AF-1% full cell: 81.88% capacity retention of after 300 cycles at 1C. The vanadium-based NASICON-type cathodes face challenges of excessive cost and capacity decay induced by structural degradation during cycling. Surface modification has been confirmed as a favorable strategy to purchase a reasonable balance between sodium storage performance and long lifespan for cathodes. A carbon/AlF 3 dual-layer artificial interface was ingeniously engineered to encapsulate the Na 2 TiV(PO 4 ) 3 cathode (NTVP). Through modulating AlF 3 coating content, the NTVP@C/AF-x% series (x = 0.5, 1, 2, 3, 5) were harvested to accelerate Na-ion diffusion and alleviate structural collapse, thereby strengthening the rate capability under high-rate conditions. Furthermore, the dual-layer artificial interface effectively reduces the polarization voltage and boosts the Na-ion diffusion coefficient. The strategy-modified NTVP@C/AF-1% cathode delivers a high specific capacity of 184.58 mAh g −1 at 0.1C, and maintains a capacity retention of 93.66% after 2500 cycles at 20C. Furthermore, the NTVP@C/AF-1% also serves as an anode, demonstrating favorable cycling durability with 91.67% capacity retention after 400 cycles at 1C. The NTVP@C/AF-1% cathode demonstrated excellent compatibility with the hard carbon anode. The assembled NTVP@C/AF-1% full cell exhibits enhanced electrochemical performance with a capacity retention of 81.88% after 300 cycles. This work demonstrates the modified interfacial structures can unlock more possibilities for the further development of NASICON-type cathodes. Download: Download high-res image (101KB) Download: Download full-size image

Limonin alleviates pyroptosis and inflammatory responses in cardiomyocytes of myocardial ischemia-reperfusion mice by inhibiting the caspase-3/GSDME pathway

Jianlong Li,Zhe Li,Pengran Wang,Zhian Jiang

PurposeMyocardial ischemia-reperfusion (I/R) is characterized by myocardial cell death and exacerbated inflammatory responses that seriously affect cardiac function and patient prognosis. Limonin is a natural compound extracted from citrus fruits and has various biological activities, including anti-inflammatory and antioxidant activities. However, the role and mechanism of action of limonin in myocardial I/R injury remain unclear. This study aimed to explore the effects and underlying mechanisms of action of limonin on myocardial cell pyroptosis and inflammatory responses in mouse myocardial I/R injury.MethodsBy analyzing the GSE225105 dataset in the Gene Expression Omnibus database, differentially expressed genes in I/R injury were screened and combined with the target genes of limonin in the Comparative Toxicogenomics Database. In the in vitro experiments, The oxygen-glucose deprivation/reoxygenation (OGD/R) model was used to simulate I/R injury in in vitro experiments.ResultsLimonin significantly inhibited OGD/R-induced pyroptosis and the release of inflammatory factors in AC16 myocardial cells, and these effects could be reversed by the caspase-3/gasdermin E (GSDME) pathway activator triclabendazole. Using in vivo experiments, we established a myocardial I/R model in C57BL/6 mice and found that limonin pretreatment improved cardiac function-related indicators, reduced myocardial tissue damage and inflammatory responses, inhibited apoptosis, and reduced myocardial fibrosis. This mechanism is closely related to the inhibition of caspase-3/GSDME pathway activation.ConclusionThis study revealed the protective effects of limonin in reducing myocardial I/R injury by inhibiting the caspase-3/GSDME pathway, thereby providing a theoretical basis for the development of limonin-based myocardial protection strategies.

Biocatalytic Bamberger Rearrangement for the Synthesis of 3-Amino-2-hydroxyacetophenone via Hydroxylaminobenzene Mutase Engineering and Multi-Enzyme System Assembly

Heng Tang,Tian-Tian Guo,Jin-xing Zhong,Ze-Yu Wu,Xiao-Yu Duan,Yu-Ze Sun,Ya-Ping Xue,Yu-Guo Zheng

The Bamberger rearrangement is a key route to functionalized aminophenols that are widely used in pharmaceutical synthesis. Hydroxylaminobenzene mutase (HabM) catalyzes a Bamberger-type isomerization in the biosynthesis of the Pranlukast intermediate 3-amino-2-hydroxyacetophenone (3AHAP), but its low catalytic efficiency and unknown structure have limited rational improvement. Here, we combine AI-assisted phylogenetic mining, structural elucidation, protein engineering, and metabolic coordination to enhance 3AHAP biosynthesis. Deep learning–guided screening identified the NR Bh -HabM Eo pair as the most effective combination, substantially outperforming previously reported systems. Using an integrated dry-wet strategy involving homology template search, spectroscopy, mutagenesis, Size-Exclusion-Chromatography analysis, and AlphaFold3-assisted modeling, we reveal that HabM Eo is a Fe-dependent tetramer. Rational mutagenesis supported by molecular dynamics simulations yielded a synergistic triple mutant with improved pocket dynamics, optimized Fe-substrate positioning, and markedly enhanced catalytic efficiency. To alleviate reductive limitations, NAD kinase was introduced to strengthen NADPH cycling; however, increased upstream flux led to intermediate accumulation and by-product formation. This was overcome by implementing a RIAD/RIDD-based scaffold to spatially organize NR, HabM, GDH, and NADK, thereby promoting intermediate channeling and suppressing over-reduction. Overall, this study elucidates the structure of HabM and established a successful paradigm for optimizing complex multi-enzyme cascades for sustainable production of high-value biopharmaceutical intermediates.