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1.
Sensors (Basel) ; 24(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38793973

RESUMO

Spaceborne synthetic aperture radar (SAR) is an advanced microwave imaging technology that provides all-weather and all-day target information. However, as spaceborne SAR resolution improves, traditional echo signal models based on airborne SAR design become inadequate due to the curved orbit, Earth rotation, and increased propagation distance. In this study, we propose an accurate range model for high-resolution spaceborne SAR by analyzing motion trajectory and Doppler parameters from the perspective of the space geometry of spaceborne SAR. We evaluate the accuracy of existing range models and propose an advanced equivalent squint range model (AESRM) that accurately fits the actual range history and compensates for high-order term errors by introducing third-order and fourth-order error terms while maintaining the simplicity of the traditional model. The proposed AESRM's concise two-dimensional frequency spectrum form facilitates the design of imaging algorithms. Point target simulations confirm the effectiveness of the proposed AESRM, demonstrating significant improvements in fitting accuracy for range histories characterized by nonlinear trajectories. The developed AESRM provides a robust foundation for designing imaging algorithms and enables higher resolution and more accurate radar imaging.

2.
Front Nutr ; 10: 1183501, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37305086

RESUMO

In order to improve the economic utilization of quinoa bran and develop a safe and highly available zinc ion biological supplement. In this study, a four-factor, three-level response surface optimization of quinoa bran soluble dietary fiber (SDF) complexation of zinc was studied. The effect used four factors on the chelation rate was investigated: (A) mass ratio of SDF to ZnSO4.7H2O, (B) chelation temperature, (C) chelation time, and (D) pH. Based on the results of the single-factor test, the four-factor three-level response surface method was used to optimize the reaction conditions. The optimal reaction conditions were observed as mentioned here: the mass ratio of quinoa bran SDF to ZnSO4.7H2O was 1, the reaction temperature was 65°C, the reaction time was 120 min, and the pH of the reaction system was 8.0. The average chelation rate was 25.18%, and zinc content is 465.2 µg/g under optimal conditions. The hydration method rendered a fluffy quinoa bran SDF structure. The intramolecular functional groups were less stable which made the formation of the lone pairs of electrons feasible to complex with the added divalent zinc ions to form a quinoa bran soluble dietary fiber-zinc complex [SDF-Zn(II)]. The SDF-Zn(II) chelate had higher 2,2-diphenylpicrylhydrazyl (DPPH), ABTS+, hydroxyl radical scavenging ability, and total antioxidant capacity. Therefore, metal ion chelation in dietary fiber is of biological importance.

3.
Front Nutr ; 10: 1123075, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36776599

RESUMO

In order to study the nutritional changes of γ-aminobutyric acid (GABA) enrichment in adzuki bean germination, vacuum combined with monosodium glutamate (MSG) was used as the germination stress of adzuki bean. The nutrient transfer before and after GABA enrichment in adzuki bean germination under vacuum combined with MSG stress were studied by means of chromatography and scanning electron microscope (SEM). The antioxidant activity and hypoglycemic effect of different solvent extracts before and after germination of adzuki bean were evaluated by experiments in vitro. The results showed that the nutritional characteristics of adzuki bean rich in GABA changed significantly (P < 0.05), the total fatty acids decreased significantly (P < 0.05), and the 21 amino acids detected increased significantly. After germination, the starch granules of adzuki bean became smaller and the surface was rough Germination stress significantly increased the antioxidant and hypoglycemic activities of the extracts from different solvents (P < 0.05), and the water extracts had the best effect on DPPH and ⋅OH radical scavenging rates of 88.52 and 83.56%, respectively. The results indicated that the germinated adzuki bean rich in GABA was more nutritious than the raw adzuki bean and had good antioxidant activity. It hoped to provide technical reference for rich food containing GABA.

4.
Front Microbiol ; 13: 895975, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35814699

RESUMO

The diversity of fungi in barley in simulated storage environments was analyzed. Barley was stored at different temperatures (15, 25, 35°C) and relative humidity (55, 65, 75, 85 RH) for 180 and 360 days. Alpha diversity, beta diversity, species composition, and species differences were analyzed using Illumina HiSeq technology. The fungal communities in all barley samples before and after storage belonged to 3 phyla, 18 classes, 39 orders, 71 families, 103 genera, and 152 species. The relative abundance of the dominant phylum Ascomycota was 77.98-99.19%. The relative abundance of Basidiomycota was 0.77-21.96%. At the genus level, the dominant genera of fungi in barley initially included Fusarium, Aspergillus, Microdochium, Alternaria, and Epicoccum. After 360 days of storage, the dominant genera became Epicoccum, Alternaria, Bipolar, Cladosporium, Fusarium, and Aspergillus. According to Venn diagrams and principal coordinates analysis, the fungal community diversity in barley initially was much higher than in barley stored at different temperatures and humidity. The application of PLS-DA could accurately distinguish between barley stored for 180 and 360 days. Some high-temperature and high-humidity environments accelerated storage. The dominant genera differed in different storage conditions and constantly changed with increasing storage duration. Epicoccum was one of the dominant genera after longer storage periods. This study provides theoretical support for optimizing safe storage conditions in barley.

5.
Front Nutr ; 9: 846409, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35399678

RESUMO

Studies have shown that inhibiting inflammation and regulating intestinal microflora imbalance is a significant factor in controlling the development of type 2 diabetes mellitus (T2DM). This experiment studied the protective effect of polyphenol extract from germinated mung beans on diabetic C57BL/6 mice. Results: Fasting blood glucose (FBG) was decreased, glucose tolerance was increased, insulin resistance was decreased, serum lipid indexes in T2DM mice were improved, and the enzyme activities of alanine aminotransferase (ALT) and aspartate transaminase (AST) in serum were reduced. Meanwhile, the levels of interleukin 6 (IL-6), tumor necrosis factor-α (TNF-α), and C-reactive protein (CRP) in serum were decreased, the concentration of interleukin 10 (IL-10) in serum was increased, inhibiting the inflammatory reaction induced by diabetes and repairing the morphology of mice liver tissue. At the same time, germinated mung bean polyphenol (GMP) can regulate the main intestinal flora, Firmicutes, Bacteroidetes, and Proteobacteria in diabetic mice and can also regulate species diversity and improve intestinal flora imbalance. Taken together, the experimental conclusion is a certain dose of polyphenol extract from germinated mung beans that can improve mouse T2DM by inhibiting inflammatory reaction and regulating intestinal microflora.

6.
Front Nutr ; 9: 849529, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35237647

RESUMO

OBJECTIVES: In this study, the effects of γ-aminobutyric acid (GABA)-rich sprouted adzuki beans on the glycolipid metabolism and gastrointestinal health were investigated in mice with type 2 diabetes mellitus (T2DM). METHODS: Mice with T2DM were subjected to dietary intervention with different doses of GABA-rich sprouted adzuki beans for 6 consecutive weeks, during which growth indicators, glycolipid metabolism, and the composition and diversity of the gut microbiota changes were observed. RESULTS: A high dietary intake of GABA-rich sprouted adzuki beans had a preventive effect against weight gain, significantly reduced serum levels of FBG, TG, and TC. Additionally, high dietary intake of GABA-rich sprouted adzuki beans increased the abundances of Firmicutes, Bacteroidetes, Verrucomicrobia, and Akkermansia, leading to a shift in the structure of the gut microbiota toward the dominance of probiotics with regulatory effects on glycolipid metabolism. CONCLUSIONS: GABA-rich sprouted adzuki beans can effectively control the bodyweight of mice with T2DM, maintain a balanced blood glucose level, improve glycolipid metabolism and the changes in the microbiota may mediate the anti-diabetic effect of sprouted adzuki beans.

7.
Front Nutr ; 8: 791191, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34970582

RESUMO

Type 2 diabetes mellitus (T2DM) is one of the most common metabolic diseases, and exploring strategies to prevent and treat diabetes has become extremely important. In recent decades the search for new therapeutic strategies for T2DM involving dietary interventions has attracted public attention. We established a diabetic mouse model by feeding mice a high-fat diet combined with injection of low-dose streptozotocin, intending to elucidate the effects and possible mechanisms of different dosages of γ-aminobutyric acid (GABA)-rich germinated adzuki beans on the treatment of diabetes in mice. The mice were treated for 6 weeks either with increasing doses of GABA-enriched germinated adzuki beans, with non-germinated adzuki beans, with GABA, or with the positive control drug metformin. Then, the blood glucose levels and blood lipid biochemical indicators of all the mice were measured. At the same time, serum differential metabolite interactions were explored by UPLC-Q/TOF-MS-based serum metabolomic analysis. The results showed that body weight and fasting blood glucose levels were significantly reduced (P < 0.05). We also report improved levels of total cholesterol, triglycerides, aspartate aminotransferase, alanine aminotransferase, urea, and serum creatinine. We observed a significant improvement in the homeostasis model assessment of the beta cell function and insulin resistance (HOMA-ß and HOMA-IR) scores (P < 0.05) in the group of mice treated with the highest dose of GABA-enriched germinated adzuki beans. In addition, the metabolic profiles of the serum were analyzed, and 31 differential metabolites including amino acids and lipids were obtained. According to the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis, this was found to be correlated with nine significantly enriched metabolic pathways involving the up-regulation of levels of L-serine, SM (d18:1/22:1(13Z)), L-histidine, creatine, and 3-indoleacetic acid. Our data suggest that the hypoglycemic effect of GABA-enriched germinated adzuki beans on diabetic mice may be related to improving tryptophan metabolism, glycerol phospholipid metabolism, sphingosline metabolism, and the glycine, serine, and threonine metabolic pathways. This study provides a reference for the application of GABA-enriched germinated foods in type 2 diabetes and could provide a cue for searching biomarkers to be adopted for T2DM diagnosis.

8.
Front Nutr ; 8: 693862, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34568402

RESUMO

This study aimed to investigate the optimal hypoxic and monosodium glutamate (MSG) stress conditions for the enrichment of γ-Aminobutyric acid (GABA) in germinating adzuki beans and to reveal the potential underlying molecular mechanisms of GABA accumulation. Using single-factor experiments and response surface model, we investigated the effects of germination time, germination temperature, vacuum time, and MSG concentration on GABA contents, and further explored the activity and gene expression of glutamate decarboxylase (GAD) and polyamine oxidase (PAO) critical rate restriction enzymes during GABA synthesis. The optimal soaking temperature, soaking time, and pH conditions were 35°C, 16 h, and 5, respectively. Furthermore, the optimal germination conditions for optimal GABA enrichment were 48 h, 1.99 mg/ml MSG concentration, germination temperature of 31.49°C, and vacuum time of 15.83 h. Under such conditions, the predicted GABA concentration was 443.57 ± 7.18 mg/100 g, with no significant difference between the predicted and experimental data. The vacuum + MSG (FZM) treatment has a maximum contribution rate of GABA to 38.29%, which significantly increase GABA content, and the increase was associated with increased GAD and PAO activity. In addition, MSG in combination with vacuum treatment could significantly induce VaGAD4 and VaGAD6 genes in 2 days germination of adzuki beans. According to the results of the present study, vacuum + MSG treatment is an effective approach to enhancing GABA accumulation in germinating adzuki beans, which could be employed in enhancing the functional quality of germinating adzuki beans.

9.
Chem Sci ; 12(48): 15928-15934, 2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-35024116

RESUMO

Manipulation of the charge transfer in donor-acceptor-type molecules is essential for the design of controllable aggregate luminescent materials. Apart from the traditional through-bond charge transfer (TBCT) systems which suffer from complicated structural design, poor tunability and low quantum efficiency, through-space charge transfer (TSCT) has been proved as an alternative yet facile strategy in tuning photophysical processes. In this work, by simply changing nucleophilic reaction bases, a traditional conjugated acrylonitrile AP1 and an unexpected non-conjugated AP2 with a carboxamide-functionalized oxirane linker could be obtained. The long-range π-π stacking in conjugated AP1 results in mixed intramolecular TBCT plus intermolecular TSCT emission. However, facilitated by the steric hindrance effect of the big oxirane connector and the unique discrete dimer packing, non-conjugated AP2 exhibits pure and efficient intermolecular TSCT emission in both aggregate and crystalline states. The flexibility of the non-conjugated character further leads to better reversible stimuli-responsiveness to mechanical force for AP2 than for the rigid AP1.

10.
Carbohydr Polym ; 233: 115831, 2020 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-32059884

RESUMO

Fibrillar gel of pepsin-solubilized collagen from tilapia skin was prepared by self-assembly in neutral phosphate buffer at 28 °C. Then effects of acidic polysaccharides, such as sodium alginate (SA), chondroitin sulfate (CS), and hyaluronic acid (HA), on the formation and properties of self-assembled fibrillar gel were investigated. SA and CS prolonged gelling time, whereas HA had no obvious effect. SA made fibril network denser, while CS and HA induced the presence of larger ordered structures. All the acidic polysaccharides broadened the D-periodicity of fibrils. SA and HA increased the maximum mechanical strength of gel to 39.64 and 34.49 kN/m2, respectively, significantly higher than that of pure collagen gel (14.53 kN/m2), while that only 17.20 kN/m2 after CS introduced. HA had no evident effect on enzymatic resistance, while SA and CS decreased. Therefore, tilapia skin collagen with HA has a higher potential as a biomaterial than that with CS or SA.


Assuntos
Materiais Biocompatíveis/química , Colágenos Fibrilares/química , Géis/química , Polissacarídeos/química , Alginatos/química , Animais , Sulfatos de Condroitina/química , Ácido Hialurônico/química , Fenômenos Mecânicos , Pele/química , Tilápia
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