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1.
Phys Chem Chem Phys ; 26(20): 14980-14990, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38739457

RESUMO

In this paper, a new GaSe/ZnS van der Waals heterostructure (vdWH) was constructed and a systematic analysis of the electronic structure, interfacial properties, and transport and photocatalytic capacity of the GaSe/ZnS vdWH was performed by using first-principles calculations. It was found that the heterostructure exhibited excellent photocatalytic performance for water splitting. The direct band gap of the heterostructure calculated using the hybrid HSE06 functional was 2.19 eV, which had a good visible light absorption ability. The electronic structure of the type-II band arrangement effectively reduced the recombination of electron-hole pairs. The heterostructure also showed excellent transport ability, and the carrier mobility of electrons and holes along different directions was greatly improved. Additionally, as the electric field strength increased, the band gap width of the GaSe/ZnS vdWH narrowed and the heterostructure characteristics transitioned from semiconductor to metal properties, which were attributed to the appearance of near-free electronic (NFE) states induced by the strong electric field. Meanwhile, the optical absorption capacity of the heterostructure was greatly improved compared to the ZnS monolayer, reaching 1.44 × 105 cm-1 at an incident photon energy of 8.65 eV. Therefore, the GaSe/ZnS vdWH was proved to be an excellent photocatalytic material for water splitting in the present study.

2.
Patient Prefer Adherence ; 18: 917-929, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38685912

RESUMO

Purpose: Advancements in electronic health (eHealth) technology have profoundly impacted patient engagement. This study aimed to develop and validate the Electronic Patient Engagement Behavior (EPEB) scale to measure the conceptual and underlying framework of patient engagement behaviors in an eHealth context. Patients and Methods: Initial measurement items were generated based on a literature review and qualitative research. Two rounds of surveys, a pilot survey and validation survey, were conducted to evaluate the psychometric properties of the scale. Results: The EPEB scale consists of 15 items in four dimensions: disease information search, physician-patient interaction, social interaction between patients, and disease self-monitoring. In the pilot survey, the exploratory factor analysis revealed a four-factor model, explaining 69.411% of variance. In the validation survey, the Cronbach's α coefficient of each sub-scale was 0.865, 0.904, 0.904, and 0.900 respectively. The Spearman-Brown split coefficient of the scale was 0.963. The results of the cross-sex measurement equivalence test indicate that all fit indices met the measurement criteria. The confirmatory factor analysis indicated second-order 4-factor model fit the data well. The EPEB has a good reliability and validity. Conclusion: The EPEB scale provides a reliable tool for measuring patient engagement behaviors in the eHealth context. The utilization of this scale may yield valuable insights into strategies for enhancing patient engagement and optimizing health outcomes.

3.
ACS Nano ; 18(13): 9486-9499, 2024 Apr 02.
Artigo em Inglês | MEDLINE | ID: mdl-38497998

RESUMO

Agrichemical losses are a severe threat to the ecological environment. Additionally, some agrichemical compounds contain abundant salt, which increases the instability of formulations, leading to a lower agrichemical utilization and soil hardening. Fortunately, the biological amphiphilic emulsifier sodium deoxycholate alleviates these problems by forming stable Janus core-shell emulsions through salinity-driven interfacial self-assembly. According to the interfacial behavior, dilational rheology, and molecular dynamics simulations, Janus-emulsion molecules are more closely arranged than traditional-emulsion molecules and generate an oil-water interfacial film that transforms into a gel film. In addition, at the same spray volume, the deposition area of the Janus emulsion increased by 37.70% compared with that of the traditional emulsion. Owing to the topology effect and deformation, the Janus emulsion adheres to rice micropapillae, achieving better flush resistance. Meanwhile, based on response of the Janus emulsion to stimulation by carbon dioxide (CO2), the emulsion lost to the soil can form a rigid shell for inhibiting the release of pesticides and metal ions from harming the soil. The pyraclostrobin release rate decreased by 50.89% at 4 h after the Janus emulsion was exposed to CO2. The Chao1 index of the Janus emulsion was increased by 12.49% as compared to coconut oil delivery in soil microbial community. The Janus emulsion ingested by harmful organisms can be effectively absorbed in the intestine to achieve better control effects. This study provides a simple and effective strategy, which turns waste into treasure, by combining metal ions in agrichemicals with natural amphiphilic molecules to prepare stable emulsions for enhancing agrichemical rainfastness and weakening environmental risk.


Assuntos
Agroquímicos , Salinidade , Emulsões/química , Dióxido de Carbono , Íons , Solo
4.
Neurol Sci ; 45(6): 2845-2851, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38228940

RESUMO

AIM: The aim of this study was to determine the usefulness of magnetic resonance imaging (MRI) characteristics in discriminating H3 K27M-mutant gliomas from wildtype gliomas in the spinal cord. MATERIALS AND METHODS: Fifty-eight patients with spinal cord gliomas were enrolled in this study. The H3 K27 gene status was identified by Sanger sequencing or immunohistochemistry test of resection tumor specimens. The MR imaging characteristics were evaluated and compared between H3 K27M-mutant and wildtype gliomas using the χ2 test and the Mann-Whitney U test. RESULTS: Of 58 recruited patients, 23 (39.7%) were diagnosed with H3 K27M-mutant glioma. The H3 K27M-mutant gliomas were found to more likely occur in men compared with wildtype gliomas (87.0% vs. 42.9%, p = 0.001). On T2-weighted MR images, the signal-to-noise ratio (SNR) of H3 K27M-mutant gliomas was significantly lower than that of wildtype gliomas (103.9 ± 72.0 vs. 168.9 ± 86.8, p < 0.001). Of 35 wildtype tumors, 60% showed well-defined margin but this feature was not found in all mutant tumors (p < 0.001). The SNR of tumors on contrast-enhanced T1-weighted images of the H3 K27M-mutant gliomas was significantly lower than that of wildtype gliomas (187.7 ± 160.4 vs. 295.1 ± 207.8, p = 0.006). Receiver operating-characteristic analysis revealed that area under curve (AUC) of combination of 1/SNR on T2-weighted images, 1/SNR on contrast-enhanced T1-weighted images, ill-defined margin, and sex reached 0.937 (95% CI, 0.873-1.000) in discriminating H3 K27M-mutant gliomas. CONCLUSIONS: The MR imaging characteristics are valuable in discriminating H3 K27M-mutant from wildtype gliomas in the spinal cord and the combination of these imaging features with sex had a high strength in this discrimination.


Assuntos
Glioma , Histonas , Imageamento por Ressonância Magnética , Mutação , Neoplasias da Medula Espinal , Humanos , Masculino , Glioma/genética , Glioma/diagnóstico por imagem , Glioma/patologia , Feminino , Imageamento por Ressonância Magnética/métodos , Neoplasias da Medula Espinal/genética , Neoplasias da Medula Espinal/diagnóstico por imagem , Neoplasias da Medula Espinal/patologia , Adulto , Pessoa de Meia-Idade , Histonas/genética , Adulto Jovem , Idoso , Adolescente , Medula Espinal/diagnóstico por imagem , Medula Espinal/patologia
5.
Int J Neural Syst ; 34(1): 2450002, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38084473

RESUMO

Functional MRI (fMRI) is a brain signal with high spatial resolution, and visual cognitive processes and semantic information in the brain can be represented and obtained through fMRI. In this paper, we design single-graphic and matched/unmatched double-graphic visual stimulus experiments and collect 12 subjects' fMRI data to explore the brain's visual perception processes. In the double-graphic stimulus experiment, we focus on the high-level semantic information as "matching", and remove tail-to-tail conjunction by designing a model to screen the matching-related voxels. Then, we perform Bayesian causal learning between fMRI voxels based on the transfer entropy, establish a hierarchical Bayesian causal network (HBcausalNet) of the visual cortex, and use the model for visual stimulus image reconstruction. HBcausalNet achieves an average accuracy of 70.57% and 53.70% in single- and double-graphic stimulus image reconstruction tasks, respectively, higher than HcorrNet and HcasaulNet. The results show that the matching-related voxel screening and causality analysis method in this paper can extract the "matching" information in fMRI, obtain a direct causal relationship between matching information and fMRI, and explore the causal inference process in the brain. It suggests that our model can effectively extract high-level semantic information in brain signals and model effective connections and visual perception processes in the visual cortex of the brain.


Assuntos
Mapeamento Encefálico , Córtex Visual , Humanos , Mapeamento Encefálico/métodos , Teorema de Bayes , Semântica , Encéfalo , Imageamento por Ressonância Magnética/métodos , Córtex Visual/diagnóstico por imagem
6.
Chemosphere ; 350: 140992, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38141676

RESUMO

Carbofuran, a widely used carbamate insecticide, is frequently detected in water. In this study, a high-performance adsorbent (WAB4) for carbofuran was obtained from laboratory-synthesized biochars. The maximum adsorption of carbofuran by WAB4 reaches 113.7 mg/g approximately. The adsorption of carbofuran by biochar was a multi-molecular layer and the adsorption process conforms to the pseudo-second-order kinetic model (R2 = 0.9984) and Freundlich isotherm model (R2 = 0.99). Importantly, an in vivo rat model was used to assess the combined toxicological effects of biochar-carbofuran complexes. The toxicity of the complexes (LD50 > 12 mg/kg) is lower than that of carbofuran (LD50 = 7.9 mg/kg) alone. The damage of biochar-carbofuran complex on rat liver and lung is significantly less than that of carbofuran. The Cmax and bioavailability of carbofuran were found to be reduced by 64% and 68%, respectively, when biochar was present, by UPLC-MS/MS analysis of carbofuran in rat plasma. Furthermore, it was confirmed that the biochar-carbofuran complex is relatively stable in the gastrointestinal tract, by performing a carbofuran release assay in artificial gastrointestinal fluids in vitro. Collectively, biochar is a bio-friendly material for the removal of carbofuran from water.


Assuntos
Carbofurano , Poluentes Químicos da Água , Animais , Ratos , Carbofurano/toxicidade , Adsorção , Água , Cromatografia Líquida , Espectrometria de Massas em Tandem , Carvão Vegetal , Cinética , Poluentes Químicos da Água/toxicidade , Poluentes Químicos da Água/análise , Concentração de Íons de Hidrogênio
7.
J Hazard Mater ; 463: 132848, 2024 02 05.
Artigo em Inglês | MEDLINE | ID: mdl-37924702

RESUMO

In this study, two strains of symbiotic bacteria (SOB-1 and SOB-2) were isolated from Scenedesmus obliquus, and various algal-bacterial mutualistic systems were established under acetochlor (ACT) stress conditions. Following exposure to varying ACT concentrations from 2.0 to 25.0 µg/L, the capacity for co-cultured bacteria to degrade ACT was enhanced in 7 days by up to 226.9% (SOB-1) and 193.0% (SOB-2), compared with axenic algae, although bacteria exposed to higher ACT concentrations exacerbated algal metabolic stress, oxidative states, apoptosis and cellular lysis. ACT reduced carbohydrates in the phycosphere by up to 31.5%; compensatory nutrient plunder and structural damage by bacteria were the potential exploitation pathways determined based on the inhibition of bacterial infection using a glucanase inhibitor. The ACT-induced reduction in algal antimicrobial substances, including fatty acids and phenolics (by up to 58.1% and 56.6%, respectively), also facilitated bacterial exploitation of algae. ACT-dependent interspecific interaction coefficients between algae and bacteria generated from long-term symbiosis cultures implied that bacteria moved from mutualism (0 and 2.0 µg/L ACT) to exploitation (7.9 and 25.0 µg/L ACT). The population dynamic model under incremental ACT-concentration scenarios inferred that theoretical systematic extinction may occur in algal-bacterial systems earlier than in axenic algae. These outcomes provide interspecific insights into the distortion of algal-bacterial reciprocity due to the ecotoxicological effects of ACT.


Assuntos
Clorofíceas , Microalgas , Microalgas/metabolismo , Simbiose , Bactérias
8.
Ultrason Sonochem ; 101: 106683, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37948893

RESUMO

In this study, we aimed to investigate the impact of various ultrasound durations on the structure and bioactivity of sweet corncob polysaccharides treated with ultrasound-assisted degradation using hydrogen peroxide and ascorbic acid (H2O2-Vc). We subjected sweet corncob polysaccharides to ultrasound treatment for 0, 30, 60, and 90 min alongside the H2O2-Vc method. We then analyzed their chemical composition and structure. Additionally, we administered these polysaccharides to mice with type 2 diabetes (T2DM) through gavage at a dosage of 200 mg/kg/day. The results indicated a significant reduction in the molecular weight of the degraded sweet corncob polysaccharides, while their composition remained relatively stable. However, the basic structure of the polysaccharides was retained. In vivo experiments demonstrated that ultrasound-assisted degradation of these polysaccharides had a positive impact on T2DM, particularly the 60-minute ultrasound treatment (UH-DSCBP-60 min), which effectively controlled blood glucose levels by regulating glycolipid metabolism in the livers of mice with T2DM. This approach also reduced inflammation and oxidative stress levels and inhibited disaccharide activity in the small intestine. We demonstrated that ultrasound can positively affect the sweet corncob polysaccharides hypoglycemic activity. The findings of our study provide a theoretical foundation for the valuable utilization of sweet corncob polysaccharides.


Assuntos
Ácido Ascórbico , Diabetes Mellitus Tipo 2 , Animais , Camundongos , Ácido Ascórbico/química , Diabetes Mellitus Tipo 2/tratamento farmacológico , Peróxido de Hidrogênio/química , Zea mays/química , Polissacarídeos/química
9.
Environ Sci Pollut Res Int ; 30(39): 91199-91206, 2023 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-37474856

RESUMO

Dimethachlon, a dicarboximide fungicide, has gained widespread usage in Asian countries. While considered a low-toxicity fungicide, concerns regarding potential health effects, such as nephrotoxicity, have emerged. To date, neither China nor other countries have established maximum residue limit (MRL) for dimethachlon on grapes, and exposure risk assessment of dimethachlon is lacking. Here, we developed a QuEChERS method coupled with gas chromatography-mass spectrometry (GC-MS) to investigate the dissipation rates and terminal residues of dimethachlon in grapes, along with an assessment of dietary risk to consumers. Our results indicated that the average recoveries of dimethachlon in grapes ranged from 74 to 76%. The limit of quantification (LOQ) was 0.050 mg/kg. After undergoing 112 days of storage at -18 °C, the dissipation rate of dimethachlon in grapes was found to be less than 30%, suggesting a state of stable storage. In the context of good agricultural practice (GAP) guidelines, the half-lives of dimethachlon in grapes were 14.3-18.1 days, which is notably longer compared to the reported values for other crops. The terminal residues of dimethachlon in grapes at 14 and 21 days were found to be < 0.05-0.53 mg/kg and < 0.05-0.29 mg/kg, respectively. Regarding the dietary risk assessment, the calculated risk quotient (RQ) value was significantly below 100%, indicating a negligible chronic risk of dimethachlon in grapes at the recommended dosage. This study provides an important reference for the analysis of dimethachlon and offers valuable empirical data to support the establishment of MRL.


Assuntos
Fungicidas Industriais , Resíduos de Praguicidas , Vitis , Fungicidas Industriais/análise , Resíduos de Praguicidas/análise , Vitis/química , Contaminação de Alimentos/análise , Meia-Vida , Medição de Risco , China
10.
Int J Neural Syst ; 33(7): 2350035, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37314000

RESUMO

Zero-shot detection (ZSD) aims to locate and classify unseen objects in pictures or videos by semantic auxiliary information without additional training examples. Most of the existing ZSD methods are based on two-stage models, which achieve the detection of unseen classes by aligning object region proposals with semantic embeddings. However, these methods have several limitations, including poor region proposals for unseen classes, lack of consideration of semantic representations of unseen classes or their inter-class correlations, and domain bias towards seen classes, which can degrade overall performance. To address these issues, the Trans-ZSD framework is proposed, which is a transformer-based multi-scale contextual detection framework that explicitly exploits inter-class correlations between seen and unseen classes and optimizes feature distribution to learn discriminative features. Trans-ZSD is a single-stage approach that skips proposal generation and performs detection directly, allowing the encoding of long-term dependencies at multiple scales to learn contextual features while requiring fewer inductive biases. Trans-ZSD also introduces a foreground-background separation branch to alleviate the confusion of unseen classes and backgrounds, contrastive learning to learn inter-class uniqueness and reduce misclassification between similar classes, and explicit inter-class commonality learning to facilitate generalization between related classes. Trans-ZSD addresses the domain bias problem in end-to-end generalized zero-shot detection (GZSD) models by using balance loss to maximize response consistency between seen and unseen predictions, ensuring that the model does not bias towards seen classes. The Trans-ZSD framework is evaluated on the PASCAL VOC and MS COCO datasets, demonstrating significant improvements over existing ZSD models.


Assuntos
Aprendizagem , Redes Neurais de Computação
11.
Molecules ; 28(9)2023 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-37175171

RESUMO

Although dicofol has been widely banned all over the world as a kind of organochlorine contaminant, it still exists in the environment. This study developed a high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS/MS) detection technique for dicofol, an environmental pollutant, for the first time using in-source fragmentation. The results confirmed that m/z 251 was the only precursor ion of dicofol after in-source fragmentation, and m/z 139 and m/z 111 were reasonable product ions. The main factors triggering the in-source fragmentation were the H+ content and solution conductivity when dicofol entered the mass spectrometer. Density functional theory can be used to analyze and interpret the mechanism of dicofol fragmentation reaction in ESI source. Dicofol reduced the molecular energy from 8.8 ± 0.05 kcal/mol to 1.0 ± 0.05 kcal/mol, indicating that the internal energy release from high to low was the key driving force of in-source fragmentation. A method based on HPLC-MS/MS was developed to analyze dicofol residues in environmental water. The LOQ was 0.1 µg/L, which was better than the previous GC or GC-MS methods. This study not only proposed an HPLC-MS/MS analysis method for dicofol for the first time but also explained the in-source fragmentation mechanism of compounds in ESI source, which has positive significance for the study of compounds with unconventional mass spectrometry behavior in the field of organic pollutant analysis and metabonomics.

12.
Int Rev Financ Anal ; 88: 102684, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-37197059

RESUMO

This study demonstrates the positive role of geographic dispersion in corporate resilience to the COVID-19 pandemic in the context of China. This association is more pronounced when firms are highly dependent on the domestic market, less likely to obtain enough financing, highly apply digital technology, and have low customer concentration. This association is attributable to the following three channels: a diversified portfolio, the maintenance of business relationships, and access to non-local resources. Overall, our findings provide a more nuanced picture of the potential impacts of corporate diversification on corporate resilience.

13.
Anal Chem ; 95(18): 7076-7081, 2023 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-37114824

RESUMO

The light-up aptamer-dimethylindole red (DIR) complexes have been applied in biochemistry analysis as promising signal transduction tools. However, the unfavorable repulsions between DIR and the long-sequence aptamer switch hinder the complex's further development, and it is urgent to engineer a feasible and efficient strategy for synchronously and rationally adjusting the DIR chemical structure and the DIR aptamer performance. Herein, we communicate a versatile docking-guided rational tailoring strategy to effectively upgrade a DNA aptamer which specifically turns on the fluorescence of a synthesized amino-functionalized DIR analogue (NH2-DIR). After optimizing with three-level tailoring strategies including molecule docking-guided tailoring, coarse tailoring, and fine tailoring, the NH2-DIR aptamer switch with higher binding affinity and specificity, considerable fluorescence-activation ability, and 40% shortened length was obtained. Integrating the experimental and docking results, the binding mechanism between NH2-DIR and the tailored aptamer was deciphered via three types of interactions.


Assuntos
Aptâmeros de Nucleotídeos , Corantes Fluorescentes , Corantes Fluorescentes/química , Carbocianinas/química , Indóis , Aptâmeros de Nucleotídeos/química
14.
Food Sci Biotechnol ; 32(6): 833-845, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-37041811

RESUMO

This study evaluates the stability of lycopene in the presence of the prepared nanostructured lipid carriers (NLCs) under different environments and food systems and the in vitro and in vivo antioxidant activity of the lycopene nanostructured lipid carriers (Lyco-NLCs) was studied. As observed in the stability experiment, Lyco-NLCs have good storage stability within 30 days. Food additives have little effect on its stability except for metal ions. Compared with free lycopene, Lyco-NLCs showed an improved antioxidant property. In in-vitro experiments, the DPPH radical scavenging rate, hydroxyl radical scavenging capacity, and ferric reducing capacity of Lyco-NLCs increased by 90.47%, 47.43%, and 45.12%, respectively. The animal experiments showed that the activities of catalase in the kidney, superoxide dismutase in the heart, and glutathione peroxidase in the liver increased by 31.48%, 42.50%, and 21.47%, respectively. The content of malondialdehyde in serum decreased by 14.13%. The results have some significance for the practical application of lycopene.

15.
Food Chem ; 421: 136149, 2023 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-37086520

RESUMO

Bifenazate is widely recognized as an effective acaricide for citrus production in various regions. Detecting both the parent compound of bifenazate and its metabolite, bifenazate-diazene, simultaneously can be challenging owing to their tendency to undergo chemical interconversion. Current methods developed for detecting bifenazate or bifenazate-diazene residues often involve lengthy incubation periods and may not effectively separate the two compounds. In this study, we developed a convenient and fast method based on a modified QuEChERS method assisted by oxidants to concurrently detect bifenazate and bifenazate-diazene. Based on preliminary analysis, it appears that ferric chloride has the ability to react with a reducing substance present in citrus, which may prevent the reduction of bifenazate-diazene. The method was validated and applied in a field trial. This work reports a novel strategy to establish a balanced 'neutral' condition to create a potential method for efficient determination of bifenazate acaricide residues in fruit matrices.


Assuntos
Acaricidas , Citrus , Resíduos de Praguicidas , Acaricidas/análise , Frutas/química , Resíduos de Praguicidas/análise
16.
Molecules ; 28(7)2023 Mar 26.
Artigo em Inglês | MEDLINE | ID: mdl-37049724

RESUMO

This study aimed to enhance the utilization value of sweet corn cob, an agricultural cereal byproduct. Sweet corn cob polysaccharide-ron (III) complexes were prepared at four different temperatures (40 °C, 50 °C, 60 °C, and 70 °C). It was demonstrated that the complexes prepared at different temperatures were successfully bound to iron (III), and there was no significant difference in chemical composition; and SCCP-Fe-C demonstrated the highest iron content. The structural characterization suggested that sweet corn cob polysaccharide (SCCP) formed stable ß-FeOOH iron nuclei with -OH and -OOH. All the four complexes' thermal stability was enhanced, especially in SCCP-Fe-C. In vitro iron (III) release experiments revealed that all four complexes were rapidly released and acted as iron (III) supplements. Moreover, in vitro antioxidant, α-glucosidase, and α-amylase inhibition studies revealed that the biological activities of all four complexes were enhanced compared with those of SCCP. SCCP-Fe-B and SCCP-Fe-C exhibited the highest in vitro antioxidant, α-glucosidase, and α-amylase inhibition abilities. This study will suggest using sweet corn cobs, a natural agricultural cereal byproduct, in functional foods. Furthermore, we proposed that the complexes prepared from agricultural byproducts can be used as a potential iron supplement.


Assuntos
Antioxidantes , Zea mays , Zea mays/química , alfa-Glucosidases , Ferro/química , Polissacarídeos/farmacologia , Polissacarídeos/química , alfa-Amilases , Digestão
17.
RSC Adv ; 13(13): 8765-8778, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936844

RESUMO

Tricyclazole, propiconazole, imidacloprid, and thiamethoxam are commonly used pesticides in paddy fields. It is necessary and practical to remove pesticides from the water environment because the low utilization rate of pesticides will produce residues in the water environment. It is known that there are few studies on the preparation of biochar adsorption pesticides by the walnut shell and few studies on the removal of tricyclazole and propiconazole. Based on this, this paper used the walnut shell as raw material and boric acid as an activator to prepare biochar by the one-step method. The boric acid modified walnut shell biochar (WAB4) with a specific surface area of 640.6 m2 g-1, exhibited the high adsorption capacity of all four pesticides (>70%) at pH 3-9. The adsorption capacities of tricyclazole, propiconazole, imidacloprid, and thiamethoxam were 171.67, 112.27, 156.40, and 137.46 mg g-1, respectively. The adsorption kinetics fitted the pseudo-second-order kinetic model and the adsorption isotherm curves conformed to the Freundlich isotherm model. The adsorption of pesticides by WAB4 was associated with hydrogen bonding, pore filling, hydrophobic effects, and π-π interactions. More significantly, WAB4 has excellent adsorption capacity compared to other adsorbents for real water samples. Finally, walnut shell biochar has no significant acute toxicity to Daphnia magna. This work shows that walnut shell-based biochar has a good effect on the removal of pesticides at a wide range of pH and is economical and safe, providing a new idea for the removal of pesticides in water.

18.
Int J Biol Macromol ; 237: 124186, 2023 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-36990401

RESUMO

Biochar materials have been widely employed for adsorption of pollutants, which necessitates further consideration of their efficiency and safety in environmental remediation. In this study, a porous biochar (AC) was prepared through the combination of hydrothermal carbonization and in situ boron doping activation to effectively adsorb neonicotinoids. The adsorption process was shown to be a spontaneous endothermic physical adsorption process, where the predominant interaction forces between the acetamiprid and AC were electrostatic and hydrophobic interactions. The maximum adsorption capacity was 227.8 mg g-1for acetamiprid and the safety of AC was verified by simulating the situation where the aquatic organism (D. magna) was exposed to the combined system (AC & neonicotinoids). Interestingly, AC was observed to reduce the acute toxicity of neonicotinoids owing to the reduced bioavailability of acetamiprid in D. magna and the newly generated expression of cytochrome p450. Thus, it enhanced the metabolism and detoxification response in D. magna, which reducing the biological toxicity of acetamiprid. This study not only demonstrates the potential application of AC from a safety perspective, but also provides insight into the combined toxicity caused by biochar after adsorption of pollutants at the genomic level, which fills the gap in related research.


Assuntos
Boro , Poluentes Químicos da Água , Adsorção , Celulose , Carvão Vegetal/química , Neonicotinoides/química , Poluentes Químicos da Água/química , Cinética
20.
Molecules ; 28(2)2023 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-36677701

RESUMO

The effects of Steam Flash-Explosion (SFE) on the physicochemical properties and molecular structure of high-temperature denatured defatted rice bran protein isolate (RBPI) were investigated. The mechanism of SFE treatment on high-temperature denatured defatted RBPI was revealed. The analysis of the physical and chemical properties of RBPI showed that the surface hydrophobicity, characteristic viscosity, and thermal stability of rice bran protein isolate were significantly affected by the pressure of saturated steam and pressure holding time. Under the conditions of 2.1 MPa and 210 s, the surface hydrophobicity index decreased significantly from 137.5 to 17.5, and the characteristic viscosity increased significantly. The peak temperature of denaturation decreases from 114.2 to 106.7 °C, and the enthalpy of denaturation decreases from 356.3 to 231.4 J/g. The higher structure (circular dichroic spectrum and endogenous fluorescence spectrum) of rice bran protein isolate was analyzed by volume rejection chromatography (SEC). The results showed that steam flash treatment could depolymerize and aggregate RBPI, and the relative molecular weight distribution changed greatly. The decrease in small molecules with poor solubility was accompanied by the increase in macromolecules (>550 kDa) soluble aggregates, which were the products of a Maillard reaction. The contents of free sulfhydryl and disulfide bonds in high-temperature rice bran meal protein isolate were significantly increased, which resulted in the increase in soluble aggregates containing disulfide bonds. Circular dichroism (CD) analysis showed that the α-helix content of the isolated protein was significantly decreased, the random curl content was increased, and the secondary structure of the isolated protein changed from order to disorder. The results of endogenous fluorescence spectroscopy showed that the high-temperature rice bran meal protein isolate was more extended, tryptophan was in a more hydrophilic microenvironment, the fluorescence intensity was reduced, and the tertiary structure was changed. In addition, the mean particle size and net surface charge of protein isolate increased in the aqueous solution, which was conducive to the development of the functional properties of the protein.


Assuntos
Oryza , Vapor , Oryza/química , Temperatura , Explosões , Dissulfetos
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