Carbon quantum dots(CQDs) with a quantum yield of 11% were synthesized via a simple, low-cost and green hydrothermal treatment using dried lemon peel as carbon source. The obtained CQDs showed a strong emission at the wavelength of 505 nm with an optimum excitation of 425 nm. Carmine with maximum absorption wavelength at 508 nm could selectively quench the fluorescence of CQDs. Based on this principle, a fluorescence probe was developed for carmine determination. The quenching mechanism of CQDs was elucidated. A linear relationship was found in the carmine concentration range of 0.20—30.00 mg/L with the detection limit(3σ/k) of 0.16 mg/L. Satisfactory results were achieved when the method was applied for the determination of carmine in soft drinks.

Immune cells are essential components of the human immune system, playing a critical role in maintaining human health and defending against diseases. Changes in nutritional metabolism influence the activation, proliferation, apoptosis, differentiation direction, and other behaviors of immune cells, affecting immune function. Amino acids, fundamental nutrients in all living organisms, are crucial for maintaining redox balance, regulating energy, supporting biosynthesis, and preserving homeostasis. The availability of amino acids influences the behaviors and functions of immune cells significantly. Therefore, understanding the intricate relationship between amino acid metabolism and immune cell behavior leads to identifying unique therapeutic targets and improving clinical outcomes. The review summarizes the impact of different types of amino acid metabolism on the behaviors of dendritic cells and T cells, hoping to provide a valuable reference for researchers and clinicians in related fields.

Chiral organocatalysts of 4-adamantane amide based on L-proline with double hydrogen potential were synthesized and used in asymmetric aldol reactions. The reactions were evaluated in toluene under‒20 °C. A series of aldol products was obtained from moderate to good yields(up to 98%) with excellent diastereoselectivities(up to >99:1) and enantioselectivities(up to >99%). The aldol products in the system were separated by α-cyclodextrin via host-guest interaction and determined by chiral HPLC. The catalyst could be reused up to five times. The 4-substitution position played an important role in diastereoselectivity and enantioselectivity.

The gene(ABK51908) from Acidothermus cellulolyticus encodes a mature protein of 484 residues with a calculated molecular mass of 53.0 kDa. Sequence analysis revealed that the protein had 59% identity to the β-glucosidases CAA82733, which belongs to glycoside hydrolase family 1(GH1). We cloned and expressed the gene in Escherichia coli BL21-Gold(DE3). The recombinant protein(AcBg) had an optimal pH and temperature of 7.0 and 70 °C, respectively. The specific activities of AcBg under optimal conditions were 290 and 33 U/mg for p-nitrophenyl-β-D-glucopyranoside(pNPG) and cellobiose, respectively. AcBg hydrolyzed the oligosaccharide sequentially from the non-reducing end to produce glucose units according to the results of HPLC analysis. AcBg showed high salt tolerance and monosaccharide-stimulation properties. Its activity rose more than 2-fold when 5 mol/L NaCl/KCl were added. The activity of the β-glucosidase was remarkably enhanced in the presence of 0.2 mol/L D-glucose(increased more than 1.9-fold), 0.1 mol/L α-methyl-D-glucose(increased more than 1.4-fold) and 1.0 mol/L D-xylose(increased more than 1.9-fold). The catalysis kinetics and structural changes in various concentrations of glucose were determined. The results indicate that glucose reduces substrate affinity and causes conformational changes.

An oligo-fluoropolymer(PFM) with functional cycloaliphatic epoxy and fluorinated groups was obtained via free radical polymerization and applied to the modification of cycloaliphatic epoxy resins(CE). The chemical structure of PFM was characterized by Fourier transform infrared(FTIR) spectroscopy, gel permeation chromatogra-phy(GPC) and nuclear magnetic resonance(NMR) spectroscopy, and the effects of different PFM concentra-tions(0.5%—6%, mass fraction) on the thermal resistance, mechanical properties, surface dewettability, light trans-mission, refractive index and various cured polymer properties were studied in detail. The DSC and TGA results demonstrate that the modified epoxy resins possess a higher thermal resistance than the neat epoxy resin. The im-provements in the surface dewettability and water resistance are caused by the high crosslinking density and the enrichment of the oligo-fluorinated random copolymers dispersed in the matrix. The fracture surface morphologies of the thermosets were investigated by scanning electron microscopy(SEM) and transmission electron microsco-py(TEM). It was observed that the optical transmittance of the composites was maintained even though microphase separation occurred during the curing process. With respect to the corresponding properties of the neat epoxy resins, the 2 phr(parts per hundreds of resin) PFM thermoset exhibited relatively better comprehensive properties, making the cured material a good candidate for light-emitting diode(LED) encapsulation.

Two novel energetic alkalic metal salts of 3,6-bis(1H-1,2,3,4-tetrazol-5-yl-amino)-1,2,4,5-tetrazine (BTATz), Li₂(BTATz)·6H₂O(compound 1) and Na₂(BTATz)·2H₂O(compound 2), have been synthesized by the reac-tion of BTATz with lithium hydroxide or sodium hydroxide in dimethylsulfoxide(DMSO) solution, respectively, and their structures were characterized by means of elemental analysis and Fourier transform infrared spectrometry(FTIR). Moreover, the single-crystal structure of compound 1 was determined by single crystal X-ray diffraction. It crystal-lizes in the monoclinic space group P1/c. Furthermore, their thermal decomposition behaviors were investigated by means of differential scanning calorimetry(DSC) and thermogravimetry-differential thermal gravimetry(TG-DTG). The results show that the exothermic decomposition peak temperatures for compounds 1 and 2 were 642.65 and 644.46 K, respectively, and the kinetic equations of the main exothermic decomposition were also derived from non-isothermal method. Additionally, the thermal safety of the two compounds was evaluated by calculating self-accelerating decomposition temperature(T _SADT) and critical temperature of thermal explosion(T _b). The results(the TSADT and T _b values are 605.43 and 635.69 K for compound 1; 607.38 and 638.96 K for compound 2) reveal that the two compounds exhibit better thermal safety than BTATz.

This study introduces an innovative method for synthesizing mordenite (MOR) by employing a combination of water glass and fumed silica as the silica source. The zeolite produced through this method exhibits a smaller grain size, a larger specific surface area, and a greater number of Brønsted acid sites compared to the conventionally synthesized mordenite using silica sol. Furthermore, the chemical environment of framework Al in MOR zeolites is influenced by different silica sources, leading to varied acid properties between the two MOR zeolites, which results in an enhanced activity of dimethyl ether carbonylation from 50% to over 83%.

A series of fluorine modified TAPO-5 molecular sieves was synthesized by one-pot method using ammo-nium hexafluorotitanate as titanium and fluorine sources. The XPS and DRS UV-Vis results indicated that the exis-tence of F could promote the formation of tetrahedrally coordinated framework Ti and Al, meanwhile, inhibit the formation of anatase TiO₂ in TAPO-5 sieves due to the unique role of F in the sol-gel process of metal ions. Further-more, TG, contact angle test, Py-FTIR and ²⁷Al MAS NMR results revealed that fluorine modification increased the surface hydrophobicity and the Lewis acidity of Ti active sites through forming Al _xF _y units in the neighborhood. All these factors make these fluorine modified TAPO-5 sieves exhibit good catalytic performance in the ammoximation of cyclohexanone.

Various imidazolium and choline-based functional ionic liquids(ILs) comprising different cations and anions were grafted onto Burkholderiacepacia lipase(BCL) through surface amino acids coupling. The catalytic ac-tivity, thermostability, organic solvent tolerance and adaptability to temperature and pH changes of the modified BCL were then evaluated in olive oil hydrolysis reaction. The results showed that different combinations of cations and anions in ILs had important influence on the catalytic performance of the modified lipases. BCL modified with IL [Choline][H₂PO₄] was the most improved lipase, in which increases by 1.2 folds in relative activity, 2.5 folds in typi-cal proton solvent(10% methanol, volume fraction), and 1.4 folds in thermostability(after incubation at 70 °C for 2 h) were achieved in relative toits native form. BCL modified with [HOOCEPEG₃₅₀IM][BF₄] had higher optimal tempe- rature and pH, and better thermosability compared with the native and other modified BCLs. The conformational changes of BCLs were also confirmed by fluorescence spectroscopy and circular dichroism spectroscopy.

The photocatalytic CO₂ cycloaddition to prepare high value-added chemicals, such as cyclic carbonates (CCs) under mild conditions is an effective strategy to realize carbon neutrality. Herein, through a three-step reaction, the porphyrin-based covalent organic polymer with bimetallic active sites (Fe-COP-Zr) is successfully obtained by coordinating Fe²⁺ and Zr⁴⁺ with porphyrin and bipyridine (Bpy), respectively. Owing to excellent photosensitivity of porphyrin moieties, Fe-COP-Zr exhibits outstanding visible light absorption, which is very important for the production of photogenerated carriers. Consequently, Fe-COP-Zr shows high photocatalytic performance towards CO₂ cycloaddition with a yield of 12.1 mmol/h, which is 6 times higher than that of pure covalent organic polymer (COP) and 3 times higher than that of monometallic Fe-COP. The reason for this excellent photocatalytic CO₂ cycloaddition performance may be ascribed to the synergistic effect of Fe and Zr sites. The photogenerated electrons are easily injected into epichlorohydrin (ECH) through Fe—O bonds to form affluent electron transition state, and interact with Zr⁴⁺ as Lewis acid sites for the ring-opening of ECH, which is the rate-determining step for the visible light boosted chemical fixation of CO₂ into CCs. This work might provide some insights for design and preparation of COPs with multiple active sites to modulate their photocatalytic activities.

We design and synthesize five novel diazocine derivatives, using diazocine as the core, amide or imine bonds as the connecting units attached with different peripheral substituents. The photoisomerization yield and thermal stability of these derivatives are tested by ¹H NMR and UV-Vis absorption spectroscopy. Among them, the imine-linked derivative exhibits the lowest photoisomerization efficiency, while the amide-linked ones show an elevated switching efficiency in transitioning from the cis to the trans configuration, compared to the unmodified 3,3′-diamino-diazocine. Furthermore, based on experiments together with density functional theory (DFT) calculations, we find that the thermal stability of these derivatives is associated with the electron cloud density and steric hindrance of their substituents. Owing to these unique photophysical properties, diazocine derivatives provide a foundation for the development and application of molecular optical switches.

The preparation of zeolite utilizing commercially available organic compounds instead of complex and expensive ones is of practical significance. Herein, we report the synthesis of germanosilicate zeolite with UOS framework by utilizing a simple and commercially available compound 3-diethylamino-1-propanol (DEAP) as organic structure-directing agent (OSDA) under fluoride condition. The synthesis has been optimized by rational modification of the variables, including the Si/Ge molar ratios, the amount of DEAP and F⁻ anions, the concentration of the synthesis gel and crystallization temperature. UOS zeolite materials were prepared with Si/Ge ratio in the range of 1–4. The physicochemical properties, including crystallinity, crystal morphology, chemical environment of framework elements, textural properties and acidity were characterized by multiple techniques. Ge atoms are proved to preferentially occupy the T sites in the double-four-ring (D4Rs) units. Compared to the isostructural IM-16 zeolite, the UOS zeolites prepared herein are of similar textural properties, such as specific surface area and micropore volume. The simple structure and commercial availability of DEAP endow this synthesis with a cost advantage over the conventional preparation of UOS zeolite, where an expensive imidazolium derivative is employed.

The removal of cadmium(Cd) from synthetic solutions by batch adsorption process was performed using eggshell powder, which is mainly composed of calcite(CaCO₃). In order to optimize the adsorption process, a re-sponse surface methodology(RSM) based on Central Composite Design(CCD) was applied. Developed model for Cd remo- val yields(R, %) response was statistically validated by variance analysis(ANOVA) which showed a high de-termination coefficient value(R ²=0.9889). According to Minitab software, the optimal conditions were found at tem-perature of 44 °C, eggshell adsorbent dose of 2.98 g, initial Cd concentration of 36.74 mg/L and initial pH of 7. Un-der these conditions, the Cd removal yield was 98.76%. The deviation value of 1.24% confirms the validity of the model for the adsorption process optimization. The adsorption isotherm has been described by a Freundlich model. In addition, the predominant sorption mechanisms are the chemisorptions or precipitation(non-reversible) and ion ex-change(reversible).

The equilibrium structures, formation energy, mechanical properties and electronic properties of Co-Sn intermetallics have been systemically studied by first-principles study. The results show that the CoSn phase is more thermodynamically stable than any other stoichiometry of Co-Sn intermetallics. With the increasing of Co content in Co-Sn intermetallics, the mechanical properties change into brittle behavior from ductility character. Adding proper amount of Co to Co-Sn intermetallics can improve the cycle performance for lithium ion battery anode. However, high Co content will lead to a poor cycle performance for Co-Sn intermetallics.

The C₃N₄/Ag composite nanosheets were facilely prepared via an in situ reduction process and Ag nanoparticles were well dispersed on the surface of C3N4 nanosheets. The unique two-dimensional structure and strong interactions between C₃N₄ nanosheets and Ag nanoparticles contributed the good surface-enhanced Raman scattering(SERS) property due to the electromagnetic field enhancement. In addition, the as-prepared C₃N₄/Ag composite nanosheets could be used as catalysts or photocatalyst for the degradation of methylene blue(MB) in the presence of NaBH₄ or under visible light. Therefore, a facile SERS monitoring of the catalytic and photocatalytic degradation process of MB and the determination of the reaction kinetics were developed.

In the paper, folic acid(FA)-mediated and β-cyclodextrin(β-CD) derivatives functionalized magnetic Fe₃O₄ nanoparticles(MNPs) were successfully prepared as drug carriers for the targeted delivery and controlled release of water-insoluble anticancer drug. FA-sulfobutyl ether-β-CD-MNPs(FA-SBE-β-CD-MNPs), FA-hydroxypropyl-β-CD-MNPs(FA-HP-β-CD-MNPs) and FA-carboxymethyl-β-CD-MNPs(FA-CM-β-CD-MNPs) were fabricated, and the loading efficiency and relative entrapment rate of curcumin are 12.04 mg/g, 95.56% for FA-SBE-β-CD-MNPs, 9.6 mg/g, 81.63% for FA-HP-β-CD-MNPs and 7.88 mg/g, 85.28% for FA-CM-β-CD-MNPs, respectively. Meanwhile, at pH=5.0, the optimal release rate of curcumin is about 46.07% for FA-SBE-β-CD-MNPs in 5 h. Cellular uptake indicates that curcumin can be selectively transported to targeting site and released from the internalized carriers. The in vitro cytotoxicity reveals that non-toxic FA-SBE-β-CD-MNPs have excellent biocompatibility on HepG2 cells in the tested concentrations. Therefore, FA-SBE-β-CD-MNPs could provide a promising platform for the targeting delivery of water insoluble anti-cancer drugs for different treatment needs of cancer therapy.

A simple and efficient colorimetric biosensing for hydrogen peroxide and glucose with peroxidase-like vitamin C(V_c) functionalized Fe₃O₄ magnetic nanoparticles(V_cFe₃O₄ MNPs) as a catalyst is reported. Compared with Fe₃O₄ MNPs and other catalysts, V_cFe₃O₄ MNPs exhibited superior catalytic properties. Kinetic studies indicated that vitamin C incorporated on Fe₃O₄ MNPs improved the affinity toward H₂O₂. As low as 0.29 μmol/L H₂O₂ can be detected with a wide linear range of 0.5―100 μmol/L H₂O₂; moreover, as low as 0.288 μmol/L glucose can be detected with a linear range of 0.5―25 μmol/L glucose. The detection method was highly sensitive in sensing H₂O₂ and glucose. The robustness of V_cFe₃O₄ MNPs rendered them suitable for wide ranging applications.

Herein, a turn-on fluorescent probe for the detection of lead ions was developed using 7-diethylaminocoumarin as the fluorophore and dibenzo-18-crown-6 as the recognition unit. The response performance to lead ions was systematically studied. The probe showed specific selectivity and high sensitivity to lead ions, with fluorescence intensity at 496 nm increasing linearly with lead ion concentration (R²=0.995) over the range of 1.0×10⁻⁷–1.0×10⁻⁶ mol/L, and an LOD of 11.4 nmol/L. Job’s plot revealed that the probe forms a 1:1 stoichiometry complex with lead ions during the recognition process. Furthermore, the sensing mechanism of the probe was confirmed by density functional theory calculations, indicating that the recognition mechanism is based on photoinduced electron transfer (PET). The introduction of lead ions blocks PET, resulting in fluorescence enhancement. Finally, it was applied in the detection of practical water samples and bioimaging, demonstrating high application value in the field of chemosensors.

In this study, Pepsin@AuNPs (Pep@AuNPs) and Trypsin@AuNPs (Try@AuNPs) were synthesized by a microfluidic droplet system using Pepsin and Trypsin as protection reagents and NaOH as reducing reagents. Compared to the synthesis method in a flask, the AuNPs synthesized by the microfluidic droplet system demonstrated uniform nucleation, superior ultraviolet absorption performance, high stability and short preparation cycles (15 min). The detection range of Cu(II) by Pep@AuNPs was 1.0–100.0 µmol/L and the detection limit was 0.3 µmol/L. The detection range of L-Cysteine by Try@AuNPs was 0.3–250.0 mmol/L and the detection limit was 0.1 mmol/L. This universal method provides an effective strategy for the detection of bioactive molecules, such as metal ions and amino acids by AuNPs with protein as a protective agent.

Indole derivatives, especially bisindolylesters, have attracted intense attention due to their important applications in medicinal chemistry and organic synthesis. Here we develop a Lewis acid-catalyzed efficient and regioselective strategy to prepare a series of symmetric and unsymmetric bisindolylesters in high to excellent yields under mild conditions. The systematic investigations, which include stoichiometric nuclear magnetic resonance (NMR) experiments and structural characterization of intermediates, have provided insights into the possible reaction mechanism for this B(C₆F₅)₃-catalyzed addition reaction. Moreover, the sequential employment of Al(C₆F₅)₃ and B(C₆F₅)₃ as catalysts enabled us to successfully prepare the unsymmetric bisindolyl-compounds in one-pot two-step manner without the separation step.