Search

The recent ωLH22t range-separated local hybrid (RSLH) is shown to provide outstanding accuracy for the notorious benchmark problem of the two lowest excited-state potential energy curves for the amino group twist in 4-(dimethylamino)benzonitrile (DMABN). However, the design of ωLH22t as a general-purpose functional resulted in less convincing performance for triplet excitations, which is an important advantage of previous LHs. Furthermore, ωLH22t uses 8 empirical parameters to achieve broad accuracy. In this work, the RSLH ωLH23ct-sir is constructed with minimal empiricism by optimizing its local mixing function prefactor and range-separation parameter for only 8 excitation energies. ωLH23ct-sir maintains the excellent performance of ωLH22t for the DMABN twist and charge-transfer benchmarks but significantly improves the errors for triplet excitation energies (0.17 vs 0.24 eV). Additional test calculations for the AE6BH6 thermochemistry test set and large dipole moment and static polarizability test sets confirm that the focus on excitation energies in the optimization of ωLH23ct-sir has not caused any dramatic errors for ground-state properties. Although ωLH23ct-sir cannot replace ωLH22t as a general-purpose functional, it is preferable for problems requiring a universally good description of localized and charge-transfer excitations of both singlet and triplet multiplicity. Current limitations on the application of ωLH23ct-sir and other RSLHs to the study of singlet-triplet gaps of emitters for thermally activated delayed fluorescence are discussed. This work also includes the first systematic analysis of the influence of the local mixing function prefactor and the range-separation parameter in an RSLH on different types of excitations. [ABSTRACT FROM AUTHOR]

In this paper, three neutral heterocycle-triazolotriazine compounds featuring multiple amino groups and nitro groups were designed and synthesized. Among them, compounds 2 and 6 exhibit high detonation performance (Dv = 8180 m s−1, 8650 m s−1; P = 26.40 GPa, 31.5 GPa), low sensitivities (IS > 40 J, FS > 360 N) and high thermal stabilities (Td = 319 °C, 320 °C) suggesting their potential as alternatives to the traditional thermal-stable explosive HNS (Dv = 7612 m s−1, P = 24.3 GPa, IS = 5 J, FS = 240 N; Td = 318 °C). Meanwhile, compound 4 displays excellent properties (Dv = 8810 m s−1, IS = 15 J, FS = 240 N, Td = 215 °C, ρ = 1.84 g cm−3) which is superior to traditional explosive RDX (Dv = 8795 m s−1, IS = 7.5 J, FS = 120 N, Td = 208 °C, ρ = 1.80 g cm−3) making it a promising candidate as a novel secondary explosive. This research not only advances the field of triazolotriazine-based energetic materials but also explores their potential applications as heat-resistant or high-energy explosives. [ABSTRACT FROM AUTHOR]

In this study, peptide‐calcium chelate was screened from antler bone hydrolysate, and its bioactivity on MC3T3‐E1 cells and its chelating mechanism were investigated. In vitro experiments showed that peptide‐calcium chelate promoted the differentiation and mineralization of MC3T3‐E1 cells. Subsequently, three novel calcium‐chelating peptides were obtained from antler bone hydrolysate using hydroxyapatite chromatography (HAC), Sephadex G‐25 gel filtration chromatography, and reversed‐phase high‐performance liquid chromatography (RP‐HPLC). Meanwhile, this work determined peptides' amino acid sequences as TKLGTQLQL, LETVILGLLKT, and KMVFLMDLLK based on LC–MS/MS. Then the present work prepared the three peptides, with the corresponding calcium‐chelating rates being verified as 87.68 ± 2.86%, 80.72 ± 0.93%, and 67.96 ± 0.98%, respectively. Fourier transform infrared (FTIR) spectroscopy, ultraviolet–visible absorption (UV–vis) spectroscopy, X‐ray diffraction (XRD), circular dichroism (CD), zeta potential, and molecular dynamics (MD) simulations were adopted to investigate the chelating mode of peptides with calcium ions. As a result, oxygen in the carboxyl group and the nitrogen in the amino group were related to calcium binding. In addition, the chelation site preferred the negatively charged carboxylate groups of Leu or Thr. The present work revealed that antler bone might be the new calcium‐chelating peptide source and elucidated their positive role in osteogenesis. [ABSTRACT FROM AUTHOR]

At present, the regulation mechanism of the number and type of amino groups in the precursor and the number of alkyl chains in amine compounds on afterglow performance is not clear. To address this problem, a series of amine compounds as carbon sources is designed and utilized AlPO‐5 zeolite as the matrix to create a range of carbon dots@zeolite composite materials (CDs@AlPO‐5). N heteroatoms not only increase the potential for triplet emission but also introduce more N/O (C═O/C═N/N─H bonds) into the system as the number of amino groups increases. The introduction of abundant active groups and the strong interaction between carbon dots (CDs) and molecular sieve matrix induces a red shift in the afterglow emission wavelength and an increase in lifetime. The quantum yields (QYs) of CDs@AlPO‐5 are affected by the type of amino groups and the number of alkyl chains in the carbon source. The higher activity of the amino reaction site and the reduction in the number of alkyl chains help to regulate the afterglow emission behavior. Intelligent selection of the type and number of amino groups is an important step toward broadening the basis for controllable preparation of highly efficient afterglow materials based on CDs. [ABSTRACT FROM AUTHOR]

The zinc (Zn) anode in zinc‐ion batteries suffers from potential defects such as wild dendrite growth, severe Zn corrosion, and violent hydrogen evolution reaction, inducing erratic interfacial charge transfer kinetics, which eventually leads to electrochemical failure. Here, collagen, a biomacromolecule, is added to achieve the reconstruction of the electrolyte hydrogen‐bonding network and the modification of the derived Zn interface. Benefiting from the electronegativity advantage of amino groups (‐NH2) in collagen, the Zn (002) crystal plane is preferentially exposed and the solid electrolyte interface (SEI) rich in ZnF2 and Zn3N2 promotes the rapid charge transfer of Zn anode. Thence, an impressive cumulative capacity of 7,500 mAh cm−2 at 30 mA cm−2 is achieved and the assembled Zn|VO2 cell exhibited robust cycle reversibility even when subject to a maximum current of 100 A g−1 and an ultra‐long cycle life of 20,000 cycles at 50 A g−1, with a single‐cycle capacity loss as low as 0.0021%. Such a convenient strategy of solvent sheathing regulation and derived interfacial manipulation opening up a promising universal approach toward long‐life and high‐rate Zn anodes. [ABSTRACT FROM AUTHOR]

Context: Inspired by the recent successful synthesis of the energetic compound 2,4,6-triamino-5-nitropyrimidine-1,3-dioxide (ICM-102), which displayed a good balance between high energy and sensitivity, the response of the structure and decomposition behaviors of ICM-102 to high pressure was systematically investigated using first principle calculations. ICM-102 exhibited a graphite-like layer structure, with the c-axis and the a-axis mainly contributing to the distance between the molecular planes. As the pressure increased from 1 atm to 10 GPa, this distance decreased from 3.166 to 2.689 Ǻ. The hydrogen bonds had the most contribution to the non-covalent interactions within the same molecular planes, resulting in the b-axis discontinuity. However, van der Waals interactions gradually appeared between molecular planes as the pressure increased to 2.5 GPa. Based on the analysis of crystal orbitals, the distribution of π bonds and the Laplacian bond order (LBO), it was determined that the generation mechanism of H2O molecules involved the cleavage of N-Oc (coordinated oxygen atoms), followed by intermolecular hydrogen transfer reactions, and ultimately the formation of H2O molecules through competition with H atoms in the amino groups within the same molecules. More importantly, the pressure dependence of LBO values for N-Oc revealed that high pressure could inhibit the ICM-102 decomposition process due to reinforcing hydrogen bonds and van der Waals interactions. This work will deepen our understanding of the stability of ICM-102 under high pressure and provide a helpful reference for its potential detonation applications. Methods: All simulations, including geometry optimization and vibration analysis under quasi-hydrostatic pressure, were conducted using the CP2K code. The PBE function and the Goldk-Teter-Hutter (GTH) pseudopotential with the double-ζ-with-polarization (DZVP) basis set were employed. Additionally, the semiempirical dispersion correction D3 (BJ) was used to account for the intermolecular dispersion force. The simulations were performed under periodic boundary conditions, with a finest grid level cutoff set to 400 Ry for the Γ point. The Broyden-Flecher-Goldfarb-Shanno (BFGS) optimization method was used, with tighter convergence criteria applied for the subsequent calculations of infrared spectra. Finally, the wave-function analysis, such as non-covalent interaction and LBO, was conducted using the Multiwfn and VMD packages. [ABSTRACT FROM AUTHOR]

Proteins frequently undergo covalent modification at the post‐translational level, which involves the covalent attachment of chemical groups onto amino acids. This can entail the singular or multiple addition of small groups, such as phosphorylation; long‐chain modifications, such as glycosylation; small proteins, such as ubiquitination; as well as the interconversion of chemical groups, such as the formation of pyroglutamic acid. These post‐translational modifications (PTMs) are essential for the normal functioning of cells, as they can alter the physicochemical properties of amino acids and therefore influence enzymatic activity, protein localization, protein–protein interactions and protein stability. Despite their inherent importance, accurately depicting PTMs in experimental studies of protein structures often poses a challenge. This review highlights the role of PTMs in protein structures, as well as the prevalence of PTMs in the Protein Data Bank, directing the reader to accurately built examples suitable for use as a modelling reference. [ABSTRACT FROM AUTHOR]

To investigate the impact of plasticizer functional groups on starch plasticization, three distinct plasticizers were selected in this study: ethylene glycol (EG), ethylenediamine (EDA), and ethylenebisformamide (EBF). Three models of the plasticizer/starch system were constructed using molecular dynamics (MD) simulations, and the analysis encompassed the computation of mean square displacement (MSD), radial distribution function (RDF), and hydrogen bonding energy for each system. Additionally, the proportions of simulation were used to prepare thermoplastic starch films, which were subsequently subjected to examinations such as DSC, XRD, FT-IR, SEM, and mechanical property testing. Comparative analysis of the simulation data from the three systems and the properties of the manufactured thermoplastic starch (TPS) established that the diverse functional groups of plasticizers significantly influenced starch plasticization. In different plasticizer functional group types, it was observed that hydroxyl groups in EG and amino groups in EDA predominantly form hydrogen bonds with hydroxyl groups in starch molecular chain. In contrast, amide groups in EBF can establish hydrogen bonds not only with hydroxyl groups of starch but also with ether bonds on the starch main chain, thereby resulting in more effective starch plasticization. [ABSTRACT FROM AUTHOR]

Summary: Alpha‐lactalbumin (α‐LA) is one of the allergens in cow's milk. Glycation modifications can be used to modulate the allergenicity of α‐LA and to clarify the effects of glycation of three reducing sugars (D‐fructose, D‐ribose, and D‐xylose) on the structure and immunoglobulin G (IgG)‐binding capacity of α‐LA. In this study, the colorimetric and spectroscopic methods reflect the degree of glycation. The structural properties of the glycation products were characterised using spectroscopic and chromatographic methods. The IgG‐binding capacity was determined by an indirect competitive enzyme‐linked immunosorbent assay. The results showed a decrease in free amino groups content, an increase in molecular weight. The α‐helix content was reduced, but the β‐sheet and irregular coil content increased, resulting in a more loosened protein structure. All three reducing sugar glycation products had higher IgG‐binding capacity, suggesting that glycation has the potential to enhance α‐LA allergenicity. This study provides different perspectives on the allergenicity of cow's milk allergens modified by different sugar glycations. [ABSTRACT FROM AUTHOR]

Here we report the development of a concise and efficient synthetic protocol for the preparation of 1H-perimidin-2-amine derivatives that contain an N-(2,2,2-trichloroethyl)carboxamide substituent near the amino group. These compounds' synthesis method is based on the interaction of naphthalene-1,8-diamine with N-(2,2,2-trichloro-1-isothiocyanatoethyl)carboxamides under reflux in acetonitrile medium for 15 minutes. This transformation is likely to pass through the stage of formation of the intermediate thiourea, which further eliminates hydrogen sulfide, which is accompanied by the closure of the perimidine cycle. Using the developed protocol, we synthesized nine new 1H-perimidin-2-amine derivatives. The yield of synthesized compounds was 67-82%. IR,1H NMR,13C NMR, 1H-1H COSY, 1H-13C HSQC, and 1H-13C HMBC spectroscopy data proved their structures. [ABSTRACT FROM AUTHOR]

BACKGROUND: Anthocyanins are polyphenolic pigments that have hypoglycemic, antioxidation, anti‐aging, and other effects. Research has shown that polyphenols can optimize the processing of dough and improve the texture and nutritional characteristics of dough products. The formation of gluten networks is decisive for the quality of flour products. The effects of purple cabbage anthocyanin (PCA) extract on the structure, microscopic morphology, and network formation of gluten protein were studied, and the types of cross‐linking between PCA and gluten protein are discussed. RESULTS: The results show that PCA extract increased the free sulfhydryl (SH) group content and the free amino group of gluten proteins, stimulated an increase in the β‐sheet ratio and the decrease of α‐helix ratio, and increased the gluten index significantly (P < 0.05). The PCA extract also induced gluten protein aggregation, increased the height of protein molecular chains, and stimulated the formation of gluten networks. When PCA extract concentrations were 4 g kg−1 and 8 g kg−1, the gluten network was more homogeneous, continuous, and dense. CONCLUSION: Appropriate anthocyanins have a positive effect on the properties of gluten and promote the formation of gluten networks. Excessive anthocyanins destroy gluten protein interaction and harm gluten cross‐linking. This study may provide a useful source of data for the production of functional flour products rich in anthocyanins. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Based on the Thermal Decomposition of Xishan coal Experiments and ReaxFF MD Simulations, the study investigated the processes and product changes in the thermal decomposition of coal and the pyrolysis of coal with Na2SO4. The results indicate that the initial temperature of thermal decomposition of Xishan coal is around 300 °C in experiments and approximately 1600 K in molecular simulations. The addition of Na2SO4 advances the initial pyrolysis temperature and promotes the generation of total number and types of products. Xishan coal pyrolysis generates a large number of small molecular gases and free radicals, and the addition of Na2SO4 promotes the generation of CO, CH4, and H2S, as well as the accumulation of a significant number of free radicals. Free Na mainly affects the evolution of N elements, promoting the formation of N into amino groups, and Na easily combines with sulfur-containing intermediates. Through the extraction of sulfur-containing intermediates and the analysis of the influence of free radicals, it was found that S elements Xishan coal ultimately forms H2S. This study microscopically confirms that in the coal with Na2SO4 system, H2S originates from the hybridised sulfur atoms in the carbon chain and free ${\rm SO}_4^{2-}$ SO 4 2 − . [ABSTRACT FROM AUTHOR]

Friction remains as the primary mode of energy dissipation and components wear, and achieving superlubricity shows high promise in energy conservation and lifetime wear protection. The results in this work demonstrate that direct superlubricity combined with superlow wear can be realized for steel/Si3N4 contacts on engineering scale when polyhydroxy alcohol solution was selectively modified by amino group. Macroscopic direct superlubricity occurs because 3-amino-1,2-propanediol molecules at the friction interface could be induced to rotate and adsorb vertically on the friction surface, forming in-situ thick and dense molecular films to passivate the asperity contacts. Furthermore, amino modification is also conducive to improving the lubrication state from boundary to mixed lubrication regime by strengthening the intermolecular hydrogen bonding interaction, presenting enhanced load-bearing capability and reduced direct solid asperity contacts. Thus, direct superlow average friction of 0.01 combined with superlow wear are achieved simultaneously. The design principle of direct superlubricity and superlow wear in this work indeed offers an effective strategy to fundamentally improve energy efficiency and provide lifetime wear protection for moving mechanical assemblies. [ABSTRACT FROM AUTHOR]

Carbon dots (CDs) have been widely adopted as optical materials because of their excellent luminescent properties. However, most of the reported synthetic methods are conducted in solvents, especially hydrothermal/solvothermal reactions, leading to intractable problems such as toxic and flammable solvents, complex and inseparable by-products, and dangerously high pressures and temperatures. Solid-phase synthesis of CDs in air is an effective solution to overcome the above issues, but solid reactions always result in uncontrolled growth and agglomeration of nanoparticles. In this study, some inorganic salts are selected as catalysts for synthesizing CDs in solid states and air, which also play as dispersants to hinder CDs aggregation. In the meantime, some aromatic derivatives containing hydroxyl and amino groups are chosen as carbon sources, ground with the optimized catalyst, and then heated together in air. The production yields are affected by the reaction time and reactant ratio, while the graphitization degrees of the CDs are determined by the reaction temperature. The IG/ID value of their Raman spectra increases from 0.59 to 0.85, and the particle size decreases from 2.5 to 1.4 nm when the synthesis temperature is increased from 200 to 280 °C. The as-prepared CDs show emission peaks ranging from 366 to 606 nm, with the photoluminescence (PL) quantum yield up to 53%. Their emission color variation mainly results from different carbon sources, which can be ascribed to the differences in the element composition, functional groups, and graphitic nitrogen content of these CDs. By dispersing CDs of different concentrations into polyvinyl alcohol (PVA) and combining them with blue LEDs, cold, standard, and warm white light emitting devices (WLEDs) are prepared, with a color rendering index (CRI) up to 84. Since the as-prepared CDs have antioxidant ability at high temperature, the as-prepared WLEDs have long lifespans, remaining the effective white luminescence after 72 h continuous work. [ABSTRACT FROM AUTHOR]

Bacterial cellulose (BC) is a polymer structurally like plant cellulose, but with superior physicochemical properties. BC and the several functionalization possibilities exhibited by cellulosic polymers have led to new versatile multifunctional materials. Several studies have investigated modifications to the BC surface to make it effective, for example, in antibacterial and adsorption terms, so, BC was functionalized with the silanes 3-Aminopropyltriethoxysilane and 3-glycidyloxypropyltrimethoxysilane in three different proportions. Although the diffractograms of the modified samples did not exhibit significant changes, this indicates FTIR spectra, with primary amino groups and stretching the vibration of Si–O–Si. Regarding drug adsorption kinetics, the samples exhibited a better fit with the pseudo-second-order model the increase in pH value promoted an increase in the maximum amount of adsorption, with values of q = 98.92 mg g−1 for Ibuprofen and q = 98.50 mg g−1 for Ketoprofen. In the in vitro release tests using gastric fluid, the release rate achieved higher values compared to PBS environments. The highest release values were observed with the samples modified by method 2 and particularly, the BC70-A sample showed the highest percentage of drug release. Controlled release can provide a smoother and prolonged release profile, resulting in a more stable response to the medication. Silanized BC showed greater inhibition for Staphylococcus aureus. [ABSTRACT FROM AUTHOR]

Based on the Thermal Decomposition of Xishan coal Experiments and ReaxFF MD Simulations, the study investigated the processes and product changes in the thermal decomposition of coal and the pyrolysis of coal with Na2SO4. The results indicate that the initial temperature of thermal decomposition of Xishan coal is around 300 °C in experiments and approximately 1600 K in molecular simulations. The addition of Na2SO4 advances the initial pyrolysis temperature and promotes the generation of total number and types of products. Xishan coal pyrolysis generates a large number of small molecular gases and free radicals, and the addition of Na2SO4 promotes the generation of CO, CH4, and H2S, as well as the accumulation of a significant number of free radicals. Free Na mainly affects the evolution of N elements, promoting the formation of N into amino groups, and Na easily combines with sulfur-containing intermediates. Through the extraction of sulfur-containing intermediates and the analysis of the influence of free radicals, it was found that S elements Xishan coal ultimately forms H2S. This study microscopically confirms that in the coal with Na2SO4 system, H2S originates from the hybridised sulfur atoms in the carbon chain and free ${\rm SO}_4^{2-}$ SO 4 2 − . [ABSTRACT FROM AUTHOR]

ABSTRACT The Maillard reaction is a reaction between sugar and the amino group of proteins. Herein, Nα‐acetyl lysine (Ac‐Lys) and fructose were the model compounds. Structural information of the intermediates and products of the reaction at pH 7.4 and 37°C was obtained using UV–Vis absorption, fluorescence, and 785‐nm excited non‐resonance Raman spectroscopy. In the 6‐h reaction, three independent components in the spectroscopic data were attributed to the solvated reactants (A), their complex (B), and a covalent‐bonded product (C). The rate constant of the change in the fraction from A to B and B to C were (9.9 ± 0.1) × 10−3 and (3.3 ± 0.1) × 10−3 min−1, respectively. Polymeric Maillard reaction products were not yet formed. The structures of the solute molecules in each state were discussed based on the spectroscopic data. [ABSTRACT FROM AUTHOR]

Degradation of heparan sulfate (HS), a glycosaminoglycan (GAG) comprised of repeating units of N-acetylglucosamine and glucuronic acid, begins in the cytosol and is completed in the lysosomes. Acetylation of the terminal non-reducing amino group of α-D-glucosamine of HS is essential for its complete breakdown into monosaccharides and free sulfate. Heparan-α-glucosaminide N-acetyltransferase (HGSNAT), a resident of the lysosomal membrane, catalyzes this essential acetylation reaction by accepting and transferring the acetyl group from cytosolic acetyl-CoA to terminal α-D-glucosamine of HS in the lysosomal lumen. Mutation-induced dysfunction in HGSNAT causes abnormal accumulation of HS within the lysosomes and leads to an autosomal recessive neurodegenerative lysosomal storage disorder called mucopolysaccharidosis IIIC (MPS IIIC). There are no approved drugs or treatment strategies to cure or manage the symptoms of, MPS IIIC. Here, we use cryo-electron microscopy (cryo-EM) to determine a high-resolution structure of the HGSNATacetyl-CoA complex, the first step in the HGSNAT-catalyzed acetyltransferase reaction. In addition, we map the known MPS IIIC mutations onto the structure and elucidate the molecular basis for mutation-induced HGSNAT dysfunction. [ABSTRACT FROM AUTHOR]

Ultralong organic phosphorescence (UOP) is essential for potential applications in bioelectronics and optoelectronics. However, the precise design of UOP materials remains a formidable challenge. Herein, a facile strategy is presented to confine dimeric chromophores for triggering UOP emission, based on the manipulation of the carbonyl, sulfonyl, and amino groups within organic phosphors. The experimental data reveal that saccharin analogs in crystals containing dimeric chromophores, confined by the (3D) hydrogen‐bonded networks, exhibit ultralong emission lifetime of up to 635 ms under ambient conditions. Whereas for saccharin analogue crystals lacking dimeric chromophores, the lifetime decreases to 54 ms, resulting in the absence of UOP emission. Moreover, the non‐toxic saccharin crystals with UOP have succeeded in drug anti‐counterfeiting. These findings will open a novel avenue for the design UOP materials and broaden the domain of UOP to diverse applications. [ABSTRACT FROM AUTHOR]

Photocatalysis-self-Fenton system, integrating photocatalysis with Fenton technology, emerge as promising approaches for environmental remediation. In this study, we introduced K, Na doped g-C 3 N 4 /FeOCl (DCN/FeOCl) catalyst, where amino groups on the DCN surface interacted with unsaturated Fe on FeOCl, forming Fe–N bonds and a Z-scheme heterojunction. The resulting DCN/FeOCl demonstrated efficient H 2 O 2 production and rapid tetracycline (TC) degradation under visible light. The Z-scheme heterojunction and nitrogen vacancy enhanced electron-hole pair separation and O 2 adsorption. Additionally, we proposed a mechanism for dual-channel photocatalytic H 2 O 2 production. This work presents a novel strategy for in-situ H 2 O 2 production and activation, facilitating water decontamination. [Display omitted] • DCN/FeOCl was successfully synthesized using multi-step methods. • Effective TC degradation was achieved in photocatalysis-self-Fenton system. • Synergistic effects enhanced photocatalytic H 2 O 2 production. • Z-scheme heterojunction enabled dual-channel pathway for H 2 O 2 production. [ABSTRACT FROM AUTHOR]

Metal particle on a support material should be small and homogeneous in size, which is desirable when using it as a catalyst. In this study, we investigated to introduce Pd nanoparticles (NPs) with narrow size distribution into NH2‐MIL‐53, which was prepared by the reaction of aluminum(III) nitrate with 2‐aminoterephthalic acid. Only by immersing it in an aqueous PdCl2 solution, followed by the reduction with NaBH4, Pd NPs of about 2 nm with unform distribution were formed in NH2‐MIL‐53 up to 3.5 wt.% Pd loadings. Amino group on the linkers in NH2‐MIL‐53 played a critical role for the introduction of (PdCl3)− as a precursor for Pd NPs, while no Pd was introduced into MIL‐53 without amino group. The obtained catalysts (Pd@NH2‐MIL‐53) showed high catalytic performance for reduction of nitrite in water. The specific activity per Pd site exposed on the surface changed greatly depending on the Pd loadings despite the size of Pd NPs unchanged. Pd@NH2‐MIL‐53 with low Pd loadings showed higher specific activity (TOF=2.9×102 h−1), which might be due to the preferential exposure of Pd(111) facet on Pd NPs. [ABSTRACT FROM AUTHOR]

A new nickel catalyzed cross‐electrophile coupling for accessing γ‐lactams (isoindolinones) as well as γ‐lactones (isobenzofuranones) via carbonylation with CO2 is documented. The protocol exploits the synergistic role of redox‐active Ni(II) complexes and AlCl3 as a CO2 activator/oxygen scavenger, leading to the formation of a wide range of cyclic amides and esters (28 examples) in good to high yields (up to 87 %). A dedicated computational investigation revealed the multiple roles played by AlCl3. In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO2‐AlCl3 adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway. [ABSTRACT FROM AUTHOR]

Background: Acute kidney injury (AKI) is a serious and common complication of cardiac surgery, for which reduced kidney perfusion is a key contributing factor. Intravenous amino acids increase kidney perfusion and recruit renal functional reserve. However, the efficacy of amino acids in reducing the occurrence of AKI after cardiac surgery is uncertain. Methods: In a multinational, double-blind trial, we randomly assigned adult patients who were scheduled to undergo cardiac surgery with cardiopulmonary bypass to receive an intravenous infusion of either a balanced mixture of amino acids, at a dose of 2 g per kilogram of ideal body weight per day, or placebo (Ringer's solution) for up to 3 days. The primary outcome was the occurrence of AKI, defined according to the Kidney Disease: Improving Global Outcomes creatinine criteria. Secondary outcomes included the severity of AKI, the use and duration of kidney-replacement therapy, and all-cause 30-day mortality. Results: We recruited 3511 patients at 22 centers in three countries and assigned 1759 patients to the amino acid group and 1752 to the placebo group. AKI occurred in 474 patients (26.9%) in the amino acid group and in 555 (31.7%) in the placebo group (relative risk, 0.85; 95% confidence interval [CI], 0.77 to 0.94; P = 0.002). Stage 3 AKI occurred in 29 patients (1.6%) and 52 patients (3.0%), respectively (relative risk, 0.56; 95% CI, 0.35 to 0.87). Kidney-replacement therapy was used in 24 patients (1.4%) in the amino acid group and in 33 patients (1.9%) in the placebo group. There were no substantial differences between the two groups in other secondary outcomes or in adverse events. Conclusions: Among adult patients undergoing cardiac surgery, infusion of amino acids reduced the occurrence of AKI. (Funded by the Italian Ministry of Health; PROTECTION ClinicalTrials.gov number, NCT03709264.). [ABSTRACT FROM AUTHOR]

Herein, we report the synthesis of a novel intramolecular donor‐acceptor (D−A) system ([12]CPP‐8TPAOMe) based on cycloparaphenylenes (CPPs) grafted with eight di(4‐methoxyphenyl)amino groups (TPAOMe) as donors. Compared to [12]CPP, D−A nanohoop exhibited significant changes in physical properties, including a large redshift (>78 nm) in the fluorescence spectrum and novel positive solvatofluorochromic properties with a maximum peak ranging from 484 nm to 546 nm. The potential applications of [12]CPP‐8TPAOMe in electron‐ and hole‐transport devices were further investigated, and its bipolar behavior as a charge transport active layer was clearly observed. [ABSTRACT FROM AUTHOR]

A new nickel catalyzed cross‐electrophile coupling for accessing γ‐lactams (isoindolinones) as well as γ‐lactones (isobenzofuranones) via carbonylation with CO2 is documented. The protocol exploits the synergistic role of redox‐active Ni(II) complexes and AlCl3 as a CO2 activator/oxygen scavenger, leading to the formation of a wide range of cyclic amides and esters (28 examples) in good to high yields (up to 87 %). A dedicated computational investigation revealed the multiple roles played by AlCl3. In particular, the simultaneous transient protection of the pendant amino group of the starting reagents and the formation of the electrophilically activated CO2‐AlCl3 adduct are shown to concur in paving the way for an energetically favorable mechanistic pathway. [ABSTRACT FROM AUTHOR]

The occurrence of peritendinous adhesion, which hampers the quality and function of the healed tendon, is strongly linked to oxidative stress, inflammatory, and infection that occur after surgery. Tendon damage and repair provide a considerable obstacle for regenerative medicine owing to the absence of patches that possess comprehensive functionality, including self‐healing capacity, anti‐inflammatory and anti‐bacterial properties, as well as tissue repair guidance. A dual dynamic crosslinked network is created by coordination bonds between catechol groups in protocatechuic aldehyde (PA) and Fe3+, as well as a dynamic Schiff base reaction between amino groups in hyaluronic acid‐adipic acid dihydrazide (HA‐ADH) and aldehyde groups in PA. The HA‐ADH@PA/Fe hydrogel exhibits self‐healing ability, tissue adhesion, anti‐bacterial activity, regulation of macrophage polarization via the NF‐κB signaling, oxidative stress elimination, and anti‐inflammation. In addition, a dual‐layer Janus patch is created, taking inspiration from the anatomy and disease progression of tendon adhesion. The inner layer of the patch, which is in direct contact with the operated tendon, is a multifunctional HA‐ADH@PA/Fe hydrogel, encircled further by a poly(ɛ‐caprolactone) (PCL) electrospinning membrane outer layer facing the surrounding tissue. The PCL@HA‐ADH@PA/Fe hydrogel patch reduced tendon adhesion and supported tissue regeneration by stimulating macrophages polarization into an anti‐inflammatory phenotype and resolving both local and systemic inflammation. This research showcased the PCL@HA‐ADH@PA/Fe hydrogel patch as an alternative therapeutic method for preventing the development of adhesions around tendons. [ABSTRACT FROM AUTHOR]

This research developed a novel composite of MOF-NH2 and graphene oxide (GO) for enhanced CO2 capture. Employing the response surface methodology-central composite design (RSM-CCD) for experiments design, various MOF-NH2/GO samples with GO loadings from 0 to 30 wt% were synthesized. The results of SEM, XRD, EDS, and BET analysis revealed that the materials maintained their MOF crystal structure, confirmed by X-ray diffraction, and exhibited unique texture, high porosity, and oxygen-enriched surface chemistry. The influence of temperature (25–65 °C) and pressure (1–9 bar) on CO2 adsorption capacity was assessed using a volumetric adsorption system. Optimum conditions were obtained at weight percent of 22.6 wt% GO, temperature of 25 °C, and pressure of 9 bar with maximum adsorption capacity of 303.61 mg/g. The incorporation of amino groups enhanced the CO2 adsorption capacity. Isotherm and kinetic analyses indicated that Freundlich and Fractional-order models best described CO2 adsorption behavior. Thermodynamic analysis showed the process was exothermic, spontaneous, and physical, with enthalpy changes of − 16.905 kJ/mol, entropy changes of − 0.030 kJ/mol K, and Gibs changes energy of − 7.904 kJ/mol. Mass transfer diffusion coefficients increased with higher GO loadings. Regenerability tests demonstrated high performance and resilience, with only a 5.79% decrease in efficiency after fifteen cycles. These findings suggest significant potential for these composites in CO2 capture technologies. [ABSTRACT FROM AUTHOR]

A new variant of Fisher indole synthesis involving Bronsted acid-catalyzed hydrohydrazination of unactivated terminal and internal acetylenes with arylhydrazines is reported. The use of polyphosphoric acid alone either as the reaction medium or in the presence of a co-solvent appears to provide the required balance for activating the C–C triple bond towards the nucleophilic attack of the hydrazine moiety without unrepairable reactivity loss of the latter due to competing amino group protonation. Additionally, the formal hydration of acetylenes to the corresponding ketones occurs under the same conditions, making it an alternative approach for generating carbonyl groups from alkynes. [ABSTRACT FROM AUTHOR]

The reaction steps involved in the 5‐hydroxymethylfurfural to 2,5‐furandicarboxylic acid conversion by means of H2O2 were investigated employing a dedicated computational protocol based on density functional theory. The catalytic environment of choice was a molecular model representing a portion of the halloysite nanotube outer surface, functionalized by an organosilane, the 3‐aminopropyltriethoxysilane, whose amino group bonds one gold atom. At this stage of the investigation, the process was fully detailed in terms of the interactions between the reaction intermediates and the catalyst, and the reaction standard free energies. In addition, the energy barriers of the elementary steps involving the hydrogen migration from the adsorbed organic species to the gold atom were analyzed. On the basis of the interaction geometries, a certain distinction among the preferred reaction path can be inferred as a function of the net negative charge characterizing the catalyst outer surface. Since the inner surface of halloysite can represent the acid environment needed to obtain 5‐hydroxymethylfurfural through dehydration of fructose, the present study is framed in a wider research field where the possibility to consider functionalized halloysite as one‐pot reactor for the valorization of biomass is explored. [ABSTRACT FROM AUTHOR]

Copyright of Shipin Kexue/ Food Science is the property of Food Science Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Coumarins still remain one of the most widely explored fluorescent dyes, with a broad spectrum of applications spanning various fields, such as molecular imaging, bioorganic chemistry, materials chemistry, or medical sciences. Their fluorescence is strongly based on a push‐pull mechanism involving an electron‐donating group (EDG), mainly located at the C7 or C8 positions of the dye core. Unfortunately, up to now, these positions have been very limited to hydroxyl or amino groups. In this study, we present in detail the synthesis of the first series of coumarins bearing a vinyl sulfide as the EDG at the C7 position. These derivatives were prepared by thiol‐yne reaction, promoted by ruthenium‐ or porphyrin‐based photoredox catalysis, enabling rapid late‐stage diversification. We also functionalized coumarins with short peptides, and BSA protein as a proof‐of‐concept study, in a single‐step process. This strategy, capable of proceeding under aqueous conditions, overcomes the protection/deprotection steps usually required by traditional methods, which also use strong bases and organic solvents. Moreover, the photophysical properties such as absorption and emission of obtained coumarins (for 3‐CF3, 3‐benzothiazole, 6–8‐difluoro derivatives), predominantly exhibited large Stokes shifts (up to 204 nm) and maintained intramolecular charge transfer (ICT) characteristics. [ABSTRACT FROM AUTHOR]

The development of an efficient alternative to the widely employed Balz‐Schiemann deaminative fluorination method (i. e. without using aryl diazonium tetrafluoroborate salt) is a challenging task. Herein, we report a convenient one‐pot method for the FeCl3‐nanocellullose mediated mechanochemical synthesis of fluoroarenes through the selective substitution of an aromatic amino group by fluorine group using pyrylium tetrafluoroborate (Pyry‐BF4) and sodium fluoride (NaF) via in situ formation of pyridinium salt intermediate. The scope of the present protocol includes synthesis of thirty‐four organofluorine compounds with excellent yields via a selective substitution (SNAr) of an amino group by fluorine. The presented concise methodology opens a pathway to access new chemical spaces for the late‐stage functionalization in pharmaceutical industries. [ABSTRACT FROM AUTHOR]

Tracer antibodies, which are labelled with fluorescent or other type of reporter molecules, are widely employed in diagnostic immunoassays. Time-resolved fluorescence immunoassay (TRFIA), recognized as one of the most sensitive immunoassay techniques, utilizes tracers labelled with lanthanide ion (Ln) chelates. The conventional approach for conjugating isothiocyanate (ITC) Ln-chelates to antibodies involves random chemical targeting of the primary amino group of Lys residues, requiring typically overnight exposure to an elevated pH of 9–9.3 and leading to heterogeneity. Moreover, efforts to enhance the sensitivity of the assays by introducing a higher number of Ln-chelates per tracer antibody are associated with an elevated risk of targeting critical amino acid residues in the binding site, compromising the binding properties of the antibody. Herein, we report a method to precisely label recombinant antibodies with a defined number of Ln-chelates in a well-controlled manner by employing the SpyTag/SpyCatcher protein ligation technology. We demonstrate the functionality of the method with a full-length recombinant antibody (IgG) as well as an antibody fragment by producing site-specifically labelled antibodies for TRFIA for cardiac troponin I (cTnI) detection with a significant improvement in assay sensitivity compared to that with conventionally labelled tracer antibodies. Overall, our data clearly illustrates the benefits of the site-specific labelling strategy for generating high-performing tracer antibodies for TRF immunoassays. [ABSTRACT FROM AUTHOR]

A series of grafted polybenzimidazoles with ratios of flexible links and rigid structures in side chains based on amino polybenzimidazole (AmPBI) was successfully prepared by simple N-substitution reaction. Due to the adequate number of amino groups on the AmPBI backbone, sufficient N–H sites reduce consumption of imidazole group during grafting reactions, while simultaneously elevating the number of proton transfer site. The grafted polybenzimidazole membranes with ratios of flexible links and rigid structures in side chains have excellent properties especially in the phosphoric acid (PA) uptake, pretty swelling ratio and proton conductivity. Importantly, PA uptake, swelling ratio, mechanical property, proton conductivity and power density can be controlled by changing the ratios of flexible links and rigid structures. The grafted membrane (AmPBI-P3) with the longer flexible link in the side chain shows a low swelling ratio of 128.62%, which is lower than that of other AmPBI-PX and AmPBI. Moreover, AmPBI-P3 shows a high proton conductivity of 126.9 mS cm−1 which is about 1.74 times higher than pure AmPBI (73.1 mS cm−1) and still reaches 91.4 mS cm−1 at 180 °C after the PA retention capacity test under 160 °C/0%RH for 240 h. A great power density of 738.5 mW/cm2 at 180 °C with dry H 2 –O 2 and no backpressure is impressive among many reported membranes. [Display omitted] • A series of grafted polybenzimidazoles was successfully prepared. • The proton conductivity of AmPBI-P3 under 180℃ is about 1.74 times higher than AmPBI. • AmPBI-P3 shows pretty retention capacity after the PA retention capacity test under 160 ℃/0%RH for 240 h. • Great power density (738.5 mW/cm2) under 180 °C implies the potential applications in HT-PEMFCs. [ABSTRACT FROM AUTHOR]

1. In order to compare the difference between different derivatisations for amino acids determination of foie gras via, reversed phase high performance liquid chromatography (HPLC), O-phthalaldehyde and 9-fluorenyl-methyl chloroformate (OPA-FMOC group), phenylisothiocyanate (PITC group) and 6-Aminoquinolyl-N-hydrox-ysuccinimidyl Carbamate (AQC group) were applied to derivatisation reagent in this current experiment. The determination results of automatic amino acid analyser were applied, and 17 amino acids were detected by these three derivatisation methods.2. The running times of OPA-FMOC group, PITC group and AQC group were 18, 45 and 35 min, respectively. There was a large difference between the results of OPA-FMOC group and results from the automatic amino acid analyser, although the difference between the results from PITC and the automatic amino acid analyser was minimal.3. In conclusion, the running time of OPA-FMOC group was shorter than that of PITC group and AQC group; the accuracy of the former was better than the OPA-FMOC group and AQC group for the determination of amino acid of foie gras. [ABSTRACT FROM AUTHOR]

For the efficient utilization of CO2 into valuable product, the attractive carbon nitride catalysts have been widely studied. In this work, heptazine‐related materials with varying degree of polymerization were designed by an intrinsically modification strategy and employed in the cycloaddition of CO2 with the bisepoxide 1, 4‐butanediol diglycidyl ether (BDODGE). We initially figured out that the sample prepared at 450 °C contained more melem hydrate, exhibiting the best performance. The epoxides conversion and corresponding cyclic carbonates selectivity could achieve 93.1 % and 99.3 % at 140 °C for 20 h without any cocatalyst and solvent, respectively. Results of the catalytic tests suggested that the high catalytic activity was dependent on big size porous structure and the synergetic effect of active amino groups and −OH groups. The role of water in maintaining the specific structure and providing active site has been proved. Moreover, the CN‐450‐W catalyst exhibited outstanding recycling stability. And finally, a plausible reaction mechanism was proposed. [ABSTRACT FROM AUTHOR]

In this study, carbon-carbon double bonds and catechol groups modified oligochitosan (OCS)/photocurable polyurethane composite films (OPU) were prepared for wound dressing application. Methacrylic anhydride (MA) was used to modify oligochitosan. The effect of the ratio of amino groups on OCS to MA on the properties of the composite films was investigated. The results showed that the OPU films possessed the best overall performance in hydrophilicity, mechanical strength, adhesion properties, and antibacterial activity when the ratio of amino groups on OCS to MA was 4:2. The prepared films may show potential application as wound dressings. [ABSTRACT FROM AUTHOR]

Due to their excellent biocompatibility and biodegradability, aliphatic polyesters are widely used in the biomedical, packaging and agricultural fields, which are usually accessed by the ring-opening polymerization (ROP) of lactones and the catalysts particularly play an important role. Herein a series of quinolinyl-urea catalysts have been synthesized via the reaction between isocyanate and aminoquinoline with an amino group at different substitution positions and characterized. In combination with 7-methyl-1, 5, 7-triazabicyclo[4,4,0]dec-5-ene (MTBD) as a cocatalyst and benzyl alcohol (BnOH) as an initiator, 1-(3,5-bis(trifluoromethyl)phenyl)-3-(quinolin-3-yl)urea (3-QU) was observed to be most active for the ROP of δ-valerolactone (δ-VL). The polymerization conditions were optimized by varying the type of organic base, catalyst concentration and reaction temperature. By changing the ratio of [M]0/[I], linear polyvalerolactones (PVLs) with different molecular weights and narrow molecular weight distribution were prepared. The kinetic and chain extension experiments were carried out to prove the "living"/controllable feature. And the NMR experiments were used to support the proposal of possible mechanism. [ABSTRACT FROM AUTHOR]

Two derivatization regents were reacted with bisoprolol (BIS), followed by liquid-chromatography-mass spectrometric analysis. 3-Bromomethyl-propyphenazone (BMP) and dansyl-chloride (Dns-Cl) were reacted via the secondary amino group using a catalyst to accelerate the reaction progress and completeness with minimal reaction byproducts. The sensitivity and the ionization efficiency of both BIS-methyl-propyphenazone (BIS-MP) and BIS-Dns via electrospray ionization were studied. The sensitivity of BIS-MP was superior to BIS-Dns. The derivatization procedure, extraction procedure, and LC-MS method were optimized and validated to achieve the monitoring of BIS in rat serum at a picogram scale. The calibration curve showed a regression coefficient value of 0.999 within a concentration spanning a range of 10–500 pg/mL. The detection limit and quantitation were 4 and 10 pg/mL, respectively. The intraday and inter-day precision values (% relative standard deviation) ranged from 0.53 to 6.91%, whereas the accuracy values (expressed as % error) ranged from −4.20 to −0.77%. The pharmacokinetic parameters were: 15,280 pg/mL for a maximum concentration of BIS (C max) at the maximum time (T max) of 1 h. BIS's elimination half-life (t 1/2) was determined to be 3 h. The value of the area under the concentration-time curve (AUC0 − t ) was 34,370 pg/mL h. [ABSTRACT FROM AUTHOR]

Mesoporous silica SBA-15 has emerged as a promising adsorbent and separation material due to its unique structural and physicochemical properties. To further enhance its performance, various surface modification strategies, including metal oxide and noble metal incorporation for improved catalytic activity and stability, organic functionalization with amino and thiol groups for enhanced adsorption capacity and selectivity, and inorganic–organic composite modification for synergistic effects, have been extensively explored. This review provides a comprehensive overview of the recent advances in the surface modification of SBA-15 for adsorption and separation applications. The synthesis methods, structural properties, and advantages of SBA-15 are discussed, followed by a detailed analysis of the different modification strategies and their structure–performance relationships. The adsorption and separation performance of functionalized SBA-15 materials in the removal of organic pollutants, heavy metal ions, gases, and biomolecules, as well as in chromatographic and solid–liquid separation, is critically evaluated. Despite the significant progress, challenges and opportunities for future research are identified, including the development of low-cost and sustainable synthesis routes, rational design of SBA-15-based materials with tailored properties, and integration into practical applications. This review aims to guide future research efforts in developing advanced SBA-15-based materials for sustainable environmental and industrial applications, with an emphasis on green and scalable modification strategies. [ABSTRACT FROM AUTHOR]

The pH‐dependent UV/Vis absorption and fluorescence of several analogs of the marine natural product ageladine A were investigated. Besides ageladine A itself, its BF2 complex and the corresponding debrominated analogs were included, as were the chloro analog of the debromoageladine‐BF2 complex, an imidazolone analog, and a triazole derivative, which lack the free amino group. Importantly, the pH‐dependence of the fluorescence of the chloro analog closely resembles that of the natural product ageladine A, but with about 25‐fold higher fluorescence intensity and a maximum between pH 3 and 6. The imidazolone derivative behaves in a complementary manner and shows fluorescence only above pH 6, but with less intensity than ageladine A. The calculated Stokes shifts agree well with the experiment, which underlines the accuracy of the DFT calculation method (ωB97XD/TApr‐cc‐pVDZ, PCM). The conformational fixation of arylated imidazo[4,5‐c]pyridines by BF2 units seems to be promising with regard to the development of novel, pH‐dependent fluorescent probes. [ABSTRACT FROM AUTHOR]

Two phenothiazine‐based electroactive compounds were synthesized by Buchwald‐Hartwig cross‐coupling reaction. The compounds consist of pyridine‐ or benzonitrile accepting moiety and phenothiazine donor fragments linked through tertiary amino linkage. The resulting electroactive compounds showed high thermal stability with 10 % weight loss temperatures of 270 and 308 °C. Both the compounds showed reversible oxidation after repeated scans of cyclic voltammetry. Experimental results in combination with the outcomes of TD‐DFT calculations, were employed to examine the emission nature of the target compounds. By demonstrating the correct choice of acceptor moiety and linking topology, the synthesized compounds were found to be emitters exhibiting efficient RTP. With emission lifetime reaching 26.04 ms and spin‐orbit coupling value of the triplet states with the singlet ground state of 18.72 cm−1, the radiative recombination of the triplet state is ensured. Having lifetimes of 26 ms and strong sensitivity to oxygen, the benzonitrile‐containing phenothiazine derivative demonstrated fast oxygen response with the quenching constant of 4.97*10−4 ppm−1 at low oxygen concentrations that is comparable to the corresponding characteristics of reported RTP‐based sensors. [ABSTRACT FROM AUTHOR]

Isoreticular metal-organic framework-3 (IRMOF-3), a porous coordination polymer, is an MOF material with the characteristics of a large specific surface area and adjustable pore size. Due to the existence of the active amino group (-NH2) on the organic ligand, IRMOF-3 has more extensive research and application potential. Herein, the main preparation methods of IRMOF-3 in existing research were compared and discussed first. Second, we classified and summarized the functionalization modification of IRMOF-3 based on different reaction mechanisms. In addition, the expanded research and progress of IRMOF-3 and their derivatives in catalysis, hydrogen storage, material adsorption and separation, carrier materials, and fluorescence detection were discussed from an application perspective. Moreover, the industrialization prospect of IRMOF-3 and the pressing problems in its practical application were analyzed and prospected. This review is expected to provide a reference for the design and application of more new nanomaterials based on IRMOF-3 to develop more advanced functional materials in industrial production and engineering applications. [ABSTRACT FROM AUTHOR]

Polyamines are molecules with multiple amino groups that are essential for cellular function. The major polyamines are putrescine, spermidine, spermine, and cadaverine. Polyamines are important for posttranscriptional regulation, autophagy, programmed cell death, proliferation, redox homeostasis, and ion channel function. Their levels are tightly controlled. High levels of polyamines are associated with proliferative pathologies such as cancer, whereas low polyamine levels are observed in aging, and elevated polyamine turnover enhances oxidative stress. Polyamine metabolism is implicated in several pathophysiological processes in the nervous, immune, and cardiovascular systems. Currently, manipulating polyamine levels is under investigation as a potential preventive treatment for several pathologies, including aging, ischemia/reperfusion injury, pulmonary hypertension, and cancer. Although polyamines have been implicated in many intracellular mechanisms, our understanding of these processes remains incomplete and is a topic of ongoing investigation. Here, we discuss the regulation and cellular functions of polyamines, their role in physiology and pathology, and emphasize the current gaps in knowledge and potential future research directions. [ABSTRACT FROM AUTHOR]

Context: Amino acids are a highly effective and environmentally friendly adsorbent for SO2. However, there has been no comprehensive study of the binding modes between amino acids and SO2 at the molecular level. In this paper, the binding modes of three amino acids (Asp, Lys, and Val) with SO2 are studied comprehensively and in detail using quantum chemical calculations. The results indicate that each amino acid has multiple binding modes: 22 for Asp, 49 for Lys, and 10 for Val. Both the amino and carboxyl groups in amino acids, as well as those in side chains, can serve as binding sites for chalcogen bonds. The binding energies range from − 6.42 to − 1.06 kcal/mol for Asp, − 12.43 to − 1.63 kcal/mol for Lys, and − 7.42 to − 0.60 kcal/mol for Val. Chalcogen and hydrogen bonds play a crucial role in the stronger binding modes. The chalcogen bond is the strongest when interacting with an amino group, with an adiabatic force constant of 0.475 mDyn/Å. Energy decomposition analysis indicates that the interaction is primarily electrostatic attraction, with the orbital and dispersive interactions dependent on the binding mode. Methods: Amino acids and complexes of amino acids with SO2 were used to do semi-empirical MD using Molclus combined with xtb at the GFN2 level. Optimization and frequency calculations of the structures were conducted using density-functional theory (DFT) B3LYP/6-311G* (with DFT-D3 correction). Single-point energy calculations were performed for all structures using DLPNO-CCSD(T)/aug-cc-pVTZ with tightPNO. Further analysis of the structures was conducted using ESP, AIM, IGMH, and sob-EDA to gain a deeper understanding of the interactions between amino acids and SO2. [ABSTRACT FROM AUTHOR]

The silk fabrics were matching dyed with three natural edible pigments (red rice red, ginger yellow and gardenia blue). By investigating the dyeing rates and lifting properties of these pigments, it was observed that their compatibilities were excellent in the dyeing process: dye dosage 2.5% (omf), mordant alum dosage 2.0% (omf), dyeing temperature 80 °C and dyeing time 40 min. The silk fabrics dyed with secondary colors exhibited vibrant and vivid color owing to the remarkable lightness and chroma of ginger yellow. However, gardenia blue exhibited multiple absorption peaks in the visible light range, resulting in significantly lower lightness and chroma for the silk fabrics dyed with tertiary colors, thus making it suitable only for matte-colored fabrics with low chroma levels. In addition, the silk fabrics dyed with these three pigments had a color fastness that exceeded grade 3 in resistance to perspiration, soap washing and light exposure, indicating acceptable wearing properties. The dyeing process described in this research exhibited a wide range of potential applications in matching dyeing of protein-based textiles with natural colorants. [ABSTRACT FROM AUTHOR]

Conjugated polymers exhibit significant potential for use in gas sensors owing to their flexibility and straightforward preparation. However, the performance of organic gas sensors based on such materials is currently suboptimal owing to their poor charge‐transport properties and limited selectivity. To address this limitation, a novel strategy that involves blending a chemically modified metal–organic framework (MOF) material, UiO‐66, with a conjugated polymer is developed. The MOF porous material is chemically modified with polar nitrogen‐containing functional groups (amino and nitro groups) to create gas molecule adsorption sites. To evaluate the impact of these modifications on the sensing performance, experiments that combined the sensing performance with a density functional theory simulation are conducted. The findings reveal that gas sensors fabricated using an amine‐functionalized MOF blended with conjugated polymers exhibit significantly higher sensitivity than home polymer devices, the sensing performance of the UiO‐66‐NH2/P3HT blend film improved by a factor of two with a sensitivity of ≈2%/ppm and an LOD of 0.001 ppt. Additionally, these devices exhibit exclusive NO2‐sensing performance for other gases such as CO2 and SO2. [ABSTRACT FROM AUTHOR]

The convenient and sensitive detection of metabolites is of great significance for understanding human health status and drug development. Solid-phase electrochemiluminescence (ECL) enzyme electrodes show great potential in metabolite detection based on the enzyme-catalyzed reaction product hydrogen peroxide (H2O2). Herein, a solid-phase ECL enzyme sensor was fabricated based on a confined emitter and an immobilized enzyme using electrostatic nanocage array, constructing a platform for the sensitive detection of cholesterol. The electrostatic cage nanochannel consists of a bipolar and bilayer vertically aligned mesoporous silica film (bp-VMSF). The upper layer of bp-VMSF is an amino-modified, positively charged VMSF (p-VMSF), and the lower layer is a negatively charged VMSF (n-VMSF). The most commonly used ECL probe tris(bipyridine)ruthenium(II) (Ru(bpy)32+) is fixed in n-VMSF by electrostatic adsorption from n-VMSF and electrostatic repulsion from the upper p-VMSF, generating significantly enhanced and stable ECL signals. The successful preparation of the electrostatic cage was characterized by scanning electron microscopy (SEM) and electrochemical methods. After amino groups on the outer surface of bp-VMSF were derivatized with aldehyde, cholesterol oxidase (ChOx) molecules were covalently immobilized. The successful construction of the enzyme electrode was characterized by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). When the corresponding enzyme substrate, cholesterol, was present in the solution, the ECL signal of Ru(bpy)32+ was quenched by the enzyme-catalyzed reaction product H2O2, enabling the high-sensitivity detection of cholesterol. The linear range for detecting cholesterol was from 0.05 mM to 5.0 mM, with a limit of detection (LOD) of 1.5 μM. [ABSTRACT FROM AUTHOR]

Benzotrifuroxan (BTF) is a powerful energetic material (EM) with high density that can be used both as a primary and a secondary explosive. However, high mechanical sensitivity limits its application prospects. To actualize its potential, cocrystallization was introduced into BTF-based EMs for insensitivity improvement in the current work. A novel cocrystal explosive composed of BTF and a non-energetic molecule (2-Nitroaniline (ONA)) was prepared with a molar ratio of 1:1. The possible mechanism of cocrystal formation was studied by the analysis and characterization of its crystal structure, and the crystal structure, thermal decomposition, and energetic properties were investigated. The results indicate that the formation of the BTF/ONA cocrystal is mainly attributed to the strong interactions of the hydrogen bonds formed between the hydrogen on the amino group in the ONA molecule and the oxygen and nitrogen atoms in BTF. The impact sensitivity of BTF/ONA is obviously reduced, with the drop height of 50% explosion probability (H50) increasing from 56.0 to 90.0 cm. The calculated detonation velocity and detonation pressure of the BTF/ONA cocrystal are 7115.26 m/s and 20.51 GPa, respectively. The decomposition peak temperature of the BTF/ONA cocrystal (191.1 °C) decreases by about 90.9 °C compared to BTF (282.0 °C). This suggests that cocrystallization could effectively reduce its impact sensitivity and produce an explosive with excellent comprehensive properties. [ABSTRACT FROM AUTHOR]