Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 79
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
bioRxiv ; 2024 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-38586029

RESUMO

Prostate cancer is an exemplar of an enhancer-binding transcription factor-driven disease. The androgen receptor (AR) enhanceosome complex comprised of chromatin and epigenetic coregulators assembles at enhancer elements to drive disease progression. The paralog lysine acetyltransferases p300 and CBP deposit histone marks that are associated with enhancer activation. Here, we demonstrate that p300/CBP are determinant cofactors of the active AR enhanceosome in prostate cancer. Histone H2B N-terminus multisite lysine acetylation (H2BNTac), which was exclusively reliant on p300/CBP catalytic function, marked active enhancers and was notably elevated in prostate cancer lesions relative to the adjacent benign epithelia. Degradation of p300/CBP rapidly depleted acetylation marks associated with the active AR enhanceosome, which was only partially phenocopied by inhibition of their reader bromodomains. Notably, H2BNTac was effectively abrogated only upon p300/CBP degradation, which led to a stronger suppression of p300/CBP-dependent oncogenic gene programs relative to bromodomain inhibition. In vivo experiments using a novel, orally active p300/CBP proteolysis targeting chimera (PROTAC) degrader (CBPD-409) showed that p300/CBP degradation potently inhibited tumor growth in preclinical models of castration-resistant prostate cancer and synergized with AR antagonists. While mouse p300/CBP orthologs were effectively degraded in host tissues, prolonged treatment with the PROTAC degrader was well tolerated with no significant signs of toxicity. Taken together, our study highlights the pivotal role of p300/CBP in maintaining the active AR enhanceosome and demonstrates how target degradation may have functionally distinct effects relative to target inhibition, thus supporting the development of p300/CBP degraders for the treatment of advanced prostate cancer.

2.
bioRxiv ; 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38562774

RESUMO

Biallelic loss of cyclin-dependent kinase 12 (CDK12) defines a unique molecular subtype of metastatic castration-resistant prostate cancer (mCRPC). It remains unclear, however, whether CDK12 loss per se is sufficient to drive prostate cancer development-either alone, or in the context of other genetic alterations-and whether CDK12-mutant tumors exhibit sensitivity to specific pharmacotherapies. Here, we demonstrate that tissue-specific Cdk12 ablation is sufficient to induce preneoplastic lesions and robust T cell infiltration in the mouse prostate. Allograft-based CRISPR screening demonstrated that Cdk12 loss is positively associated with Trp53 inactivation but negatively associated with Pten inactivation-akin to what is observed in human mCRPC. Consistent with this, ablation of Cdk12 in prostate organoids with concurrent Trp53 loss promotes their proliferation and ability to form tumors in mice, while Cdk12 knockout in the Pten-null prostate cancer mouse model abrogates tumor growth. Bigenic Cdk12 and Trp53 loss allografts represent a new syngeneic model for the study of androgen receptor (AR)-positive, luminal prostate cancer. Notably, Cdk12/Trp53 loss prostate tumors are sensitive to immune checkpoint blockade. Cdk12-null organoids (either with or without Trp53 co-ablation) and patient-derived xenografts from tumors with CDK12 inactivation are highly sensitive to inhibition or degradation of its paralog kinase, CDK13. Together, these data identify CDK12 as a bona fide tumor suppressor gene with impact on tumor progression and lends support to paralog-based synthetic lethality as a promising strategy for treating CDK12-mutant mCRPC.

3.
Foods ; 13(8)2024 Apr 17.
Artigo em Inglês | MEDLINE | ID: mdl-38672904

RESUMO

Epigallocatechin gallate (EGCG), the key constituent of tea polyphenols, presents challenges in terms of its lipid solubility, stability, and bioavailability because of its polyhydroxy structure. Consequently, structural modifications are imperative to enhance its efficacy. This paper comprehensively reviews the esterification techniques applied to EGCG over the past two decades and their impacts on bioactivities. Both chemical and enzymatic esterification methods involve catalysts, solvents, and hydrophobic groups as critical factors. Although the chemical method is cost-efficient, it poses challenges in purification; on the other hand, the enzymatic approach offers improved selectivity and simplified purification processes. The biological functions of EGCG are inevitably influenced by the structural changes incurred through esterification. The antioxidant capacity of EGCG derivatives can be compromised under certain conditions by reducing hydroxyl groups, while enhancing lipid solubility and stability can strengthen their antiviral, antibacterial, and anticancer properties. Additionally, esterification broadens the utility of EGCG in food applications. This review provides critical insights into developing cost-effective and environmentally sustainable selective esterification methods, as well as emphasizes the elucidation of the bioactive mechanisms of EGCG derivatives to facilitate their widespread adoption in food processing, healthcare products, and pharmaceuticals.

4.
Sci Total Environ ; 925: 171726, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38492591

RESUMO

Polycyclic aromatic hydrocarbons (PAHs), a group of seriously hazardous environmental contaminants, have attracted extensive attention due to their carcinogenicity, genotoxicity, mutagenicity, and ubiquity. In this work, the excellent hydrophobic trifluoromethyl-enriched covalent organic framework (CF3-COF) was designed and synthesized as coating of solid-phase microextraction (SPME). The CF3-COF offered a high adsorption selectivity for PAHs, which could be attributed to the multiple interactions between the CF3-COF and PAHs, including hydrophobicity interaction, π-π and H bond interactions. Furthermore, headspace (HS) and direct immersion (DI) dual-mode solid-phase microextraction (HS/DI-SPME) were innovatively integrated as a dual-mode extraction by varying the length of SPME coating on stainless-steel, which could simultaneously and efficiently extract 16 PAHs with different volatile. Amazingly, the proposed strategy achieved fast adsorption for PAHs and shortened the adsorption equilibrium time to 15 min. By further integrating with gas chromatography tandem mass spectrometry (GC-MS/MS), PAHs could be detected in the range of 0.008-0.16 ng mL-1 with a quantitative limit of 0.029-0.47 ng mL-1, respectively. The recoveries of PAHs in water samples ranged from 80.84 to 117.67 %. This work indicates that the dual-mode CF3-COF-SPME is a promising candidate for the enrichment of multiple hazardous substances in complicated samples.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes Químicos da Água , Hidrocarbonetos Policíclicos Aromáticos/análise , Microextração em Fase Sólida/métodos , Espectrometria de Massas em Tandem , Cromatografia Gasosa-Espectrometria de Massas , Poluentes Químicos da Água/análise , Limite de Detecção , Interações Hidrofóbicas e Hidrofílicas , Água/química
6.
Int J Biol Macromol ; 261(Pt 2): 129900, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38316329

RESUMO

The presence of potentially toxic elements and compounds poses threats to the quality and safety of fruit juices. Among these, Hg(II) is considered as one of the most poisonous heavy metals to human health. Traditional chitosan-based and selenide-based adsorbents face challenges such as poor adsorption capacity and inconvenient separation in juice applications. In this study, we prepared nano­selenium functionalized chitosan gel beads (nanoSe@CBs) and illustrated the synergistic promotions between chitosan and nanoSe in removing Hg(II) from apple juice. The preparation conditions, adsorption behaviors, and adsorption mechanism of nanoSe@CBs were systematically investigated. The results revealed that the adsorption process was primarily controlled by chemical adsorption. At the 0.1 % dosage, the adsorbent exhibited high uptake, and the maximum adsorption capacity from the Langmuir isotherm model could reach 376.5 mg/g at room temperature. The adsorbent maintained high adsorption efficiency (> 90 %) across a wide range of Hg(II) concentrations (0.01 to 10 mg/L) and was unaffected by organic acids present in apple juice. Additionally, nanoSe@CBs showed negligible effects on the quality of apple juice. Overall, nanoSe@CBs open up possibilities to be used as a safe, low-cost and highly-efficient adsorbent for the removal of Hg(II) from juices and other liquid foods.


Assuntos
Quitosana , Malus , Mercúrio , Selênio , Poluentes Químicos da Água , Humanos , Sucos de Frutas e Vegetais , Malus/química , Quitosana/química , Adsorção , Cinética , Concentração de Íons de Hidrogênio
7.
Food Chem ; 443: 138537, 2024 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-38309027

RESUMO

Aflatoxin B1 (AFB1) can accumulate in different organs or tissues and seriously harm humans. Traditional magnetic relaxation switching (MRS) sensors have relatively low sensitivity, but are complex to use. Rapid small-trace molecule analysis in complex samples is challenging. In this study, we used a gadolinium-based metal-organic framework (Gd-MOF) and ultra-small superparamagnetic iron oxide (USPIO) assembly to develop a magnetic resonance tuning-magnetic relaxation switching (MRET-MRS) sensor to improve conventional MRS sensor sensitivity and simplify operational steps in complex samples. Importantly, the local magnetic field generated by USPIO interfered with Gd-MOF electron spin fluctuation and directly affected dipole-dipole interactions between Gd electrons and water molecules, thus rendering relaxation signal changes more sensitive. The sensitivity (0.54 pg mL-1) was 833 times more sensitive than that of a conventional MRS sensor (0.45 ng mL-1). Finally, a convenient one-step detection approach can be achieved by mixing antigen/antibody functionalized Gd-MOF/USPIO and target samples.


Assuntos
Dextranos , Nanopartículas de Magnetita , Estruturas Metalorgânicas , Humanos , Gadolínio , Aflatoxina B1 , Espectroscopia de Ressonância Magnética
8.
Food Chem ; 442: 138484, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38271913

RESUMO

Transglutaminase (TGase) induced-crosslinking of soy protein isolate (SPI) was markedly influenced by the substrate aggregation state. Results showed that appropriate heating significantly accelerated the TGase crosslinking, and the 7S and 11S acidic subunits were more susceptible to the enzyme than the 11S basic proteins. The content of ε-(γ-glutamyl)-lysine isopeptide bonds increased from 4.74 to 8.61 µmol/g protein when the heating intensity was increased from 75 °C for 15 min to 95 °C for 30 min, due to sufficient unfolding of the protein structure. Rheological data indicated that the gel formed from the SPI heated at 95 °C for 30 min exhibited the best properties, with a 60 % increase in the storage modulus compared with the unheated sample. However, excessive heating (95 °C, 60-120 min) caused severe aggregation of SPI and formation of insoluble aggregates, resulting in poor crosslinking efficiency and weaker gel properties.


Assuntos
Proteínas de Soja , Transglutaminases , Proteínas de Soja/química , Solubilidade , Transglutaminases/metabolismo
9.
J Hazard Mater ; 465: 133189, 2024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38071772

RESUMO

Due to the complexity of biological sample matrix, the automated and high-throughput pretreatment technology is urgently needed for monitoring the antipsychotic drugs for mental patients. In this study, functionalized magnetic zirconium-based organic framework nanocomposites (Fe3O4@SiO2@Zr-MOFs) were successfully designed and synthesized by the layer-by-layer growth. Among them, Fe3O4@SiO2@UiO-67-COOH showed the best adsorption performance, and at the same time it exhibited excellent water dispersibility, high thermal stability, chemical stability and high hydrophobicity. Results of adsorption kinetics, isotherm and FT-IR showed that the adsorption process was dominated by chemical adsorption (hydrogen bond, electrostatic interaction, π-π interaction) and monolayer adsorption. Moreover, the smaller pore size improved the protein exclusion rate which reached 98.9-99.8%. Based on the above result, the synthesized magnetic nanoparticles were introduced to 96-well automatic extractor, antipsychotic drugs in 96 serum samples were automatically extracted within 9 min, which most greatly saved the time and labor costs and avoided artificial errors. By further integrating with ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS), antipsychotic drugs can be detected in the range of 0.2-3.0 ng mL-1 with a quantitative limit of 0.06-0.9 ng mL-1. The recoveries of antipsychotic drugs and their metabolites in serum ranged from 95.7% to 112.3% within 1.4-6.5% of RSD. These features indicate that the proposed method is promising for high throughput and sensitively monitoring of drugs and other hazardous substances.


Assuntos
Antipsicóticos , Estruturas Metalorgânicas , Nanocompostos , Humanos , Estruturas Metalorgânicas/química , Cromatografia Líquida , Espectrometria de Massas em Tandem , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Extração em Fase Sólida/métodos , Cromatografia Líquida de Alta Pressão , Adsorção , Fenômenos Magnéticos , Nanocompostos/química , Limite de Detecção
10.
Int J Biol Macromol ; 253(Pt 7): 127411, 2023 Dec 31.
Artigo em Inglês | MEDLINE | ID: mdl-37838131

RESUMO

This study investigates the effects of heat treatment before high-pressure homogenization (HHPH) and heat treatment after high-pressure homogenization (HPHH) at different pressures (20, 60, and 100 MPa) on the structural and emulsification properties of soy protein isolate (SPI). The results indicate that HHPH treatment increases the surface hydrophobicity (H0) of the SPI, reduces ß-fold and irregular curls, leading to the formation of soluble aggregates, increased adsorbed protein content, and subsequent improvements in emulsification activity index (EAI) and emulsion stability index (ESI). In contrast, the HPHH treatment promoted the exchange of SH/SS bonds between protein molecules and facilitated the interaction of basic peptides and ß-subunits, leading to larger particle sizes of the soluble aggregates compared to the HHPH-treated samples. However, excessive aggregation in HPHH-treated aggregates leads to decreased H0 and adsorbed protein content, and increased interfacial tension, negatively affecting the emulsification properties. Compared to the HPHH treatment, HHPH treatment at homogenization pressures of 20 to 100 MPa increases EAI and ESI by 5.81-29.6 % and 5.31-25.9 %, respectively. These findings provide a fundamental basis for soybean protein manufacturers to employ appropriate processing procedures aimed at improving emulsification properties.


Assuntos
Temperatura Alta , Proteínas de Soja , Proteínas de Soja/química , Emulsões/química , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula
11.
Molecules ; 28(13)2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37446885

RESUMO

Some food-derived bioactive peptides exhibit prominent immunoregulatory activity. We previously demonstrated that the rice-derived PEP1 peptide, GIAASPFLQSAAFQLR, has strong immunological activity. However, the mechanism of this action is still unclear. In the present study, full-length transcripts of mouse dendritic cells (DC2.4) treated with PEP1 were sequenced using the PacBio sequencing platform, and the transcriptomes were compared via RNA sequencing (RNA-Seq). The characteristic markers of mature DCs, the cluster of differentiation CD86, and the major histocompatibility complex (MHC-II), were significantly upregulated after the PEP1 treatment. The molecular docking suggested that hydrogen bonding and electrostatic interactions played important roles in the binding between PEP1, MHC-II, and the T-cell receptor (TCR). In addition, the PEP1 peptide increased the release of anti-inflammatory factors (interleukin-4 and interleukin-10) and decreased the release of pro-inflammatory factors (interleukin-6 and tumor necrosis factor-α). Furthermore, the RNA-seq results showed the expression of genes involved in several signaling pathways, such as the NF-κB, MAPK, JAK-STAT, and TGF-ß pathways, were regulated by the PEP1 treatment, and the changes confirmed the immunomodulatory effect of PEP1 on DC2.4 cells. This findings revealed that the PEP1 peptide, derived from the byproduct of rice processing, is a potential natural immunoregulatory alternative for the treatment of inflammation.


Assuntos
Oryza , Animais , Camundongos , Oryza/genética , Simulação de Acoplamento Molecular , Peptídeos/farmacologia , Peptídeos/metabolismo , Perfilação da Expressão Gênica , Células Dendríticas
12.
Foods ; 12(11)2023 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-37297348

RESUMO

The Maillard reaction (MR) is a complicated chemical process that has been extensively studied. Harmful chemicals known as advanced glycation end products (AGEs), with complex structures and stable chemical characteristics, are created during the final stage of the MR. AGEs can be formed both during the thermal processing of food and in the human body. The number of AGEs formed in food is much higher compared to endogenous AGEs. A direct connection exists between human health and the build-up of AGEs in the body, which can result in diseases. Therefore, it is essential to understand the content of AGEs in the food we consume. The detection methods of AGEs in food are expounded upon in this review, and the advantages, disadvantages, and application fields of these detection methods are discussed in depth. Additionally, the production of AGEs in food, their content in typical foods, and the mechanisms influencing their formation are summarized. Since AGEs are closely related to the food industry and human health, it is hoped that this review will further the detection of AGEs in food so that their content can be evaluated more conveniently and accurately.

13.
Synth Syst Biotechnol ; 8(2): 323-330, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37168606

RESUMO

d-Mannose is an attractive functional sugar that exhibits many physiological benefits on human health. The demand for low-calorie sugars and sweeteners in foods are increasingly available on the market. Some sugar isomerases, such as d-lyxose isomerase (d-LIase), can achieve an isomerization reaction between d-mannose and d-fructose. However, the weak thermostability of d-LIase limits its efficient conversion from d-fructose to d-mannose. Nonetheless, few studies are available that have investigated the molecular modification of d-LIase to improve its thermal stability. In this study, computer-aided tools including FireProt, PROSS, and Consensus Finder were employed to jointly design d-LIase mutants with improved thermostability for the first time. Finally, the obtained five-point mutant M5 (N21G/E78P/V58Y/C119Y/K170P) showed high thermal stability and catalytic activity. The half-life of M5 at 65 °C was 10.22 fold, and the catalytic efficiency towards 600 g/L of d-fructose was 2.6 times to that of the wild type enzyme, respectively. Molecular dynamics simulation and intramolecular forces analysis revealed a thermostability mechanism of highly rigidity conformation, newly formed hydrogen bonds and π-cation interaction between and within protein domains, and redistributed surface electrostatic charges for the mutant M5. This research provided a promising d-LIase mutant for the industrial production of d-mannose from d-fructose.

14.
Nutrients ; 15(10)2023 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-37242256

RESUMO

The relationship between the structure of peptides LR5 (LHKFR) and YR6 (YGLYPR) and their antioxidant and anti-inflammatory activity remains unclear. Herein, leucine, tyrosine, proline, and phenylalanine at different positions in the peptides were replaced by Alanine (Ala), and two new pentapeptides (AR5 and LAR5) and four hexapeptides (AGR6, YAR6, YLR6, and YGR6) were obtained. The effect of Ala replacement on the hydrophobicity, cytotoxicity, NO inhibition rate, and active oxygen radical scavenging ability of these peptides and their antioxidant and anti-inflammatory abilities were investigated. The results indicated that the hydrophobicity of the peptides was associated with their amino acid composition and their specific sequence. However, hydrophobicity had no significant effect on cytotoxicity. Ala replacement was shown to enhance hydrophobicity and consequently increased the antioxidant and anti-inflammatory activity of the peptides. The molecular docking studies indicated that the amino acid interactions of the peptide with the Keap1 protein influenced the hydrophobicity and thus affected the antioxidant activity of the peptide.


Assuntos
Alanina , Oryza , Alanina/farmacologia , Antioxidantes/farmacologia , Antioxidantes/química , Sequência de Aminoácidos , Simulação de Acoplamento Molecular , Proteína 1 Associada a ECH Semelhante a Kelch , Fator 2 Relacionado a NF-E2 , Peptídeos/farmacologia , Peptídeos/química , Aminoácidos , Anti-Inflamatórios/farmacologia
15.
Foods ; 12(7)2023 Apr 04.
Artigo em Inglês | MEDLINE | ID: mdl-37048344

RESUMO

In this study, soy isoflavones-loaded nanoparticles were prepared using rice proteins (RPs) hydrolyzed by four types of enzyme (alcalase, neutrase, trypsin, and flavorzyme). After optimizing the preparation conditions, the encapsulation efficiency (EE) of the nanoparticles ranged from 61.16% ± 0.92% to 90.65% ± 0.19%. The RPs that were hydrolyzed by flavorzyme with a molecular weight of <5 KDa showed better characters on the formation of nanoparticles, and the formed nanoparticles had the highest EE and loading capacity (9.06%), the smallest particle size (64.77 nm), the lowest polymer dispersity index (0.19), and the lowest zeta potential (-25.64 mV).The results of Fourier transform ion cyclotron resonance, X-ray diffraction, and fluorescence spectroscopy showed that the nanoparticles were successfully encapsulated. The study of interaction showed that the formation of nanoparticles may depend mainly on hydrogen bonds, but other interactions, such as hydrophobic interactions and electrostatic interactions, cannot be ignored. After encapsulation, the pH stability, temperature stability, ionic stability, and oxidation resistance of the nanoparticles were enhanced. Moreover, the in vitro release experiment showed that the encapsulated nanoparticles had a certain protective effect on soybean isoflavones. In summary, rice protein hydrolysates are promising carriers for soybean isoflavones.

16.
Anal Methods ; 15(3): 343-352, 2023 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-36594622

RESUMO

For environmental safety, it is important to establish a simple, rapid, and sensitive method for emerging pollutants. Here, a dispersive solid-phase extraction (d-SPE) method based on an iron-based metal-organic framework (Fe-MIL-88-NH2) combined with high-performance liquid chromatography (HPLC) was developed for tetrabromobisphenol A (TBBPA) in water samples. Fe-MIL-88-NH2 was synthesized using a solvothermal method and completely characterized. Fe-MIL-88-NH2 had good water stability and gave a maximum adsorption capacity of 40.97 mg g-1 for TBBPA. The adsorption of TBBPA on Fe-MIL-88-NH2 followed Langmuir adsorption models and a pseudo-second-order kinetic model. The bromine ion and the hydroxyl group of TBBPA could form strong hydrogen bond interactions with the amino protons around the cavity of Fe-MIL-88-NH2, which was in accord with the molecular simulation calculations. Furthermore, several important d-SPE parameters were optimized, such as the amount of materials, extraction time, pH, ionic strength, elution solvent type, and volume. The established method showed good linearity in the concentration range of 0.005-100 µg g-1 (r2 ≥ 0.9996). This method's limits of detection (LOD) and quantification (LOQ) were 0.001 µg g-1 and 0.005 µg g-1, respectively. The recoveries in spiked water samples ranged from 87.5% to 104.9%. The proposed method was applied successfully to detect TBBPA in environmental water samples.


Assuntos
Estruturas Metalorgânicas , Estruturas Metalorgânicas/química , Adsorção , Ferro/química , Extração em Fase Sólida/métodos , Água
17.
Environ Sci Pollut Res Int ; 30(1): 322-336, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-35902519

RESUMO

The frequent exposure of the widely used dye, basic fuchsin (BF), is seriously threatening the health of human central nervous system. Thus, removing the environmental pollution caused by BF is crucial, and photocatalytic technology recently has been used to degrade the pollutions dye. In this study, the binary composite SrAl2O4:Eu2+, Dy3+/g-C3N4 was prepared by high-temperature calcination and then applied in BF photodegradation. The results confirmed that the composite material had lower band gap value (Eg) and stronger visible light absorption ability. The photocatalytic capacity of the new composite materials was enhanced compared to that of the non-composite materials. By using the new binary-composited materials, 80% of BF could be degraded in 10 min, and the degradation ratio reached 100% in 30 min. More importantly, even the light source was removed, the photocatalytic reaction could continue due to the luminescence of SrAl2O4:Eu2+, Dy3+, and the degradation efficiency of BF could finally reach more than 90% within 3 h. By quenching experiments and electron spin resonance (ESR) spectra analysis, superoxide anion (·O2-) was verified to be the main active substance in this reaction process. Moreover, the excellent stability and recyclability of this catalyst was also proved. Furthermore, the new composite materials were utilized to degrade the BF aqueous solution and actual lake water, and the total organic matter contents (TOC) were measured. TOC values in these two systems decreased after photocatalytic reaction, which indicated that this catalyst has a great development prospect in the removal of organic matter in water. Our study confirmed a new kind of material of high performance with great significance for emergency treatment of water pollution in practical applications.


Assuntos
Grafite , Luminescência , Humanos , Luz , Água , Catálise
18.
J Colloid Interface Sci ; 629(Pt A): 409-421, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36087555

RESUMO

Methylene blue (MB) is a very widely used cationic dye for color cotton and silk products. The harmful MB has a complex aromatic structure that is difficult to be degraded in natural aqueous. In this study for the first time, a novel double Z-type ternary composite long-afterglow/graphitic carbon nitride@metal-organic framework (SrAl2O4:Eu2+,Dy3+/g-C3N4@NH2-UiO-66, SGN) has been synthesized by solvothermal method, and was used as a new photocatalyst for removal of MB. The photocatalytic performance of the composited photocatalyst SGN was largely improved compared to that of the non-composite. After 30 min of photocatalysis, the degradation ratio of SGN was 5.86, 4.04 and 10 times more efficient than that of long-afterglow (SAO), g-C3N4 and NH2-UiO-66, respectively. The high photocatalytic activity of the SGN could be ascribed to the double Z-type electron transfer mechanism. More importantly, due to the luminescence of SAO, the degradation ratio of ternary SGN can reach about 50 % after 5 h in the dark. Superoxide anion (·O2-) was verified to be the main active substance in the photocatalytic process by quenching experiments and electron spin resonance (ESR) spectra analysis. The total organic matter contents (TOC) and partial degradation products were measured, which confirmed that some MB was mineralized into H2O and CO2, and some was degraded into smaller molecules. Moreover, the excellent stability and recyclability of this catalyst were also investigated. Here, a new promising material with high degradation performance for water pollution treatment is presented.


Assuntos
Estruturas Metalorgânicas , Poluentes Químicos da Água , Azul de Metileno/química , Superóxidos , Dióxido de Carbono , Poluentes Químicos da Água/química , Seda
19.
Food Res Int ; 161: 111737, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36192870

RESUMO

To date, the poor solubility of rice protein (RP) has limited its industrial application in food products. This study aimed to prepare high-solubility RP conjugates using ultrasound-assisted glycation between RP and dextran. The conditions of glycation, treatment at 82 °C for 22 min under 600 W ultrasonic power, were optimized using single-factor experiments and response surface analysis. The solubility of the conjugates reached 90.6 %. Compared with traditional wet-heating glycation, ultrasound-assisted treatment brought more high-molecular-weight components, higher degree of graft, and less contents of arginine and lysine, indicating that ultrasound accelerated the glycation reaction. Ultrasound also resulted in a looser and more flexible structure of RP, manifesting in a 10 % reduction in ß-sheets and 10.6 % increase in random coils of conjugates. The analysis of fluorescence and surface hydrophobicity indicated that ultrasound increased the exposure of hydrophobic residues towards aqueous environment. Besides solubility, the foaming and emulsifying properties of RP were improved through conformational changes. In summary, ultrasound-assisted glycation was found to be an efficient and green method for preparing high-solubility RP conjugates.


Assuntos
Oryza , Arginina , Dextranos , Lisina , Solubilidade
20.
RSC Adv ; 12(38): 25041-25047, 2022 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-36199884

RESUMO

The design and construction of a novel magnetic resonance switch (MRS) sensor for cadmium ion (Cd2+) detection is described. Fe3O4@ZIF-8 was synthesized through seed-mediated growth of dimercaptosuccinic acid-coated Fe3O4. Fe3O4@ZIF-8 with high relaxation value (163.086 mM-1 s-1) and large negative zeta potential (-20.69 mV) exhibited good magnetic relaxation performance and water solubility. The successfully synthesized Fe3O4@ZIF-8 was used to develop an immune recognition-based MOFs-MRS sensor for highly sensitive detection of Cd2+. The proposed MRS detected a wide linear range of Cd2+ concentration from 2 to 200 ng mL-1 with a low limit of detection of 0.65 ng mL-1 (S/N = 3), and displayed high selectivity towards matrix interference. The robust sensing system was effective even in a complex sample matrix, enabling the quantitative analysis of Cd2+ content in rice samples and drinking water samples with good reliability. Recoveries of Cd2+ ranged from 91.50 to 112.05% for spiked drinking water and from 95.86 to 110.45% for spiked rice samples. The versatility of Fe3O4@ZIF-8 with customized relaxation responses could allow the adaptation of magnetic resonance platforms for food safety purposes.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...