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1.
Int J Pharm ; 660: 124303, 2024 Jun 05.
Article in English | MEDLINE | ID: mdl-38848801

ABSTRACT

Although the combination of anti-vascular strategy plus immunotherapy has emerged as the optimal first-line treatment of hepatocellular carcinoma, lack of tumor targeting leads to low antitumor efficacy and serious side effect. Here, we report an ultra-pH-sensitive nanoparticle of gambogenic acid (GNA) encapsulated by poly(ethylene glycol)-poly(2-azepane ethyl methacrylate) (PEG-PAEMA) for tumor-targeting combined therapy of anti-vascular strategy plus immunotherapy. PEG-PAEMA-GNA nanoparticle was quite stable at pH 7.4 for 30 d. In contrast, it exerted size shrinkage, charge reversal and the release of GNA at pH 6.7 within 24 h. Moreover, PEG-PAEMA-GNA significantly enhanced the anti-vascular activity, membrane-disruptive capability and pro-apoptosis when pH changed from 7.4 to 6.7. Western blot analysis exhibits that PEG-PAEMA and its GNA nanoparticle facilitated the phosphorylation of STING protein. In vivo assays show that PEG-PAEMA-GNA not only displayed much higher tumor inhibition of 92 % than 37 % of free GNA, but also inhibited tumor vasculature, promoted the maturation of dendritic cells and recruited more cytotoxic t-lymphocytes for sufficient anti-vascular therapy and immunotherapy. All these results demonstrate that PEG-PAEMA-GNA displayed tumor-targeting combined treatment of anti-vascular therapy and immunotherapy. This study offers a simple and novel method for the combination of anti-vascular therapy and immunotherapy with high selectivity towards tumor.

2.
Asian J Androl ; 2024 May 03.
Article in English | MEDLINE | ID: mdl-38722110

ABSTRACT

ABSTRACT: Ejaculation is regulated by the central nervous system. However, the central pathophysiology of primary intravaginal anejaculation (PIAJ) is unclear. The present study aimed to examine the changes in regional brain activity and functional connectivity underlying PIAJ. A total of 20 PIAJ patients and 16 healthy controls (HCs) were enrolled from September 2020 to September 2022 in the Department of Andrology, Nanjing Drum Tower Hospital (Nanjing, China). Magnetic resonance imaging data were acquired from all participants and then were preprocessed. The measures of fractional amplitude of low-frequency fluctuation (fALFF), regional homogeneity (ReHo), and functional connectivity (FC) were calculated and compared between the groups. PIAJ patients showed increased fALFF values in the left precuneus compared with HCs. Additionally, PIAJ patients showed increased ReHo values in the left precuneus, left postcentral gyrus, left superior occipital gyrus, left calcarine fissure, right precuneus, and right middle temporal gyrus, and decreased ReHo values in the left inferior parietal gyrus, compared with HCs. Finally, brain regions with altered fALFF and ReHo values in PIAJ patients showed increased FC with widespread cortical regions, which included the frontal, parietal, temporal, and occipital regions, compared with HCs. In conclusion, increased regional brain activity in the parietal, temporal, and occipital regions, and increased FC between these brain regions, may be associated with PIAJ occurrence.

3.
Chemistry ; : e202400803, 2024 May 16.
Article in English | MEDLINE | ID: mdl-38752562

ABSTRACT

To meet the demand for higher energy density in lithium-ion batteries and expand their application range, coupling lithium metal anodes with high-voltage cathodes is an ideal solution. However, the compatibility between lithium metal batteries and electrolytes affects their applicability. In this study, proposes a locally concentrated electrolyte based on ethyl acetate (EA) as the solvent, lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) as the lithium salt, and lithium difluorooxoborate (LiDFOB) as a sacrificial agent to enhance the low-temperature and high-voltage endurance of Li//Lithium cobalt oxide (LCO) batteries. The Li//LCO battery can operate within the voltage range of 3 to 4.5 V, with an initial discharge specific capacity of 174.5 mAh g-1 at 20 oC. At -40 oC, after 200 cycles, the capacity retention rate is 87.7%. It can operate under extreme conditions of -70 oC, with a discharge specific capacity of 112.6 mAh g-1. Additionally, LCO//HC batteries using this electrolyte demonstrate excellent performance. Present work provides a new perspective for the optimization of electrolytes for low-temperature lithium-ion batteries.

4.
J Biomater Sci Polym Ed ; : 1-25, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38769597

ABSTRACT

Docetaxel (Doc), as a first-line chemotherapy drug for prostate cancer (PC), often loses its therapeutic efficacy due to acquired resistance and lack of targeting specificity. Therefore, there is a need to develop a novel drug that can overcome Doc resistance and enhance its targeting ability to inhibit PC progression. In this study, we prepared Au/Doc/Quer@PDA/A10-3.2 nanoparticles (NPs) composite drug by encapsulating Doc and quercetin (Quer) within polydopamine (PDA)-coated Au NPs and further modifying them with RNA oligonucleotide aptamer A10-3.2. A10-3.2 was used for specific targeting of prostate-specific membrane antigen (PSMA)-positive PC cells (LNCaP). Quer was employed to reverse the resistance of Doc-resistant cell line (LNCaP/R) to Doc. Physical characterization using ultraviolet-visible spectroscopy (UV-vis), transmission electron microscopy (TEM), dynamic light scattering (DLS), X-ray photoelectron spectroscopy (XPS), and Fourier-transform infrared spectroscopy (FTIR) confirmed the successful preparation of Au/Doc/Quer@PDA/A10-3.2 NPs. Fluorescence imaging and flow cytometry experiments demonstrated the targeting ability of Au/Doc/Quer@PDA/A10-3.2 NPs towards PSMA-positive LNCaP/R cells. Cell proliferation, apoptosis, invasion, and migration experiments revealed that Quer reversed the resistance of LNCaP/R cells to Doc. Immunoblotting experiments further confirmed the mechanism behind sensitization of chemotherapy by Quer. Finally, we evaluated the therapeutic efficacy of Au/Doc/Quer@PDA/A10-3.2 NPs in a mouse model of PC. In conclusion, this study synthesized and validated a novel nano-composite drug (Au/Doc/Quer@PDA/A10-3.2 NPs) for combating Doc-resistant PC, which could potentially be applied in clinical treatment of PC.

6.
BMC Med ; 22(1): 206, 2024 May 20.
Article in English | MEDLINE | ID: mdl-38769523

ABSTRACT

BACKGROUND: Numerous studies have been conducted to investigate the relationship between ABO and Rhesus (Rh) blood groups and various health outcomes. However, a comprehensive evaluation of the robustness of these associations is still lacking. METHODS: We searched PubMed, Web of Science, Embase, Scopus, Cochrane, and several regional databases from their inception until Feb 16, 2024, with the aim of identifying systematic reviews with meta-analyses of observational studies exploring associations between ABO and Rh blood groups and diverse health outcomes. For each association, we calculated the summary effect sizes, corresponding 95% confidence intervals, 95% prediction interval, heterogeneity, small-study effect, and evaluation of excess significance bias. The evidence was evaluated on a grading scale that ranged from convincing (Class I) to weak (Class IV). We assessed the certainty of evidence according to the Grading of Recommendations Assessment, Development, and Evaluation criteria (GRADE). We also evaluated the methodological quality of included studies using the A Measurement Tool to Assess Systematic Reviews (AMSTAR). AMSTAR contains 11 items, which were scored as high (8-11), moderate (4-7), and low (0-3) quality. We have gotten the registration for protocol on the PROSPERO database (CRD42023409547). RESULTS: The current umbrella review included 51 systematic reviews with meta-analysis articles with 270 associations. We re-calculated each association and found only one convincing evidence (Class I) for an association between blood group B and type 2 diabetes mellitus risk compared with the non-B blood group. It had a summary odds ratio of 1.28 (95% confidence interval: 1.17, 1.40), was supported by 6870 cases with small heterogeneity (I2 = 13%) and 95% prediction intervals excluding the null value, and without hints of small-study effects (P for Egger's test > 0.10, but the largest study effect was not more conservative than the summary effect size) or excess of significance (P < 0.10, but the value of observed less than expected). And the article was demonstrated with high methodological quality using AMSTAR (score = 9). According to AMSTAR, 18, 32, and 11 studies were categorized as high, moderate, and low quality, respectively. Nine statistically significant associations reached moderate quality based on GRADE. CONCLUSIONS: Our findings suggest a potential relationship between ABO and Rh blood groups and adverse health outcomes. Particularly the association between blood group B and type 2 diabetes mellitus risk.


Subject(s)
ABO Blood-Group System , Meta-Analysis as Topic , Observational Studies as Topic , Rh-Hr Blood-Group System , Systematic Reviews as Topic , Humans , Systematic Reviews as Topic/methods , Observational Studies as Topic/methods
7.
Phys Chem Chem Phys ; 26(20): 14832-14838, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38721813

ABSTRACT

Magnetic molecules are promising candidates for quantum information processing (QIP) due to their tunable electron structures and quantum properties. A high spin Co(II) complex, CoH2dota, is studied for its potential to be used as a quantum bit (qubit) utilizing continuous wave (CW) and pulsed electron paramagnetic resonance (EPR) spectroscopy at low temperature. On the X-band microwave energy scale, the system can be treated as an effective spin 1/2 with a strongly anisotropic g-tensor resulting from the significant spin-orbital coupling. An experimental and theoretical study is conducted to investigate the anisotropic Rabi oscillations of the two magnetically equivalent spin centres with different orientations in a single crystal sample, which aims to verify the relationship between the Rabi frequency and the orientation of the g-tensor. The findings of this study show that an effective quantum manipulation method is developed for orthorhombic spin systems.

8.
Genetica ; 2024 May 24.
Article in English | MEDLINE | ID: mdl-38789817

ABSTRACT

The Universal Stress Protein (USP) primarily participates in cellular responses to biotic and abiotic stressors, playing a pivotal role in plant growth, development, and Stress responses to adverse environmental conditions. Totals of 23, 26 and 26 USP genes were recognized in Arabidopsis thaliana, Zea mays, and Oryza sativa, respectively. According to USP genes physicochemical properties, proteins from USP I class were identified as hydrophilic proteins with high stability. Based on phylogenetic analysis, USP genes family were classified into nine groups, USP II were rich in motifs. Additionally, members of the same subgroup exhibited similar numbers of introns/exons, and shared conserved domains, indicating close evolutionary relationships. Motif analysis results demonstrated a high degree of conservation among USP genes. Chromosomal distribution suggested that USP genes might have undergone gene expansion through segmental duplication in Arabidopsis thaliana, Zea mays, and Oryza sativa. Most Ka/Ks ratios were found to be less than 1, suggesting that USP genes in Arabidopsis thaliana, Zea mays, and Oryza sativa have experienced purifying selection. Expression profile analysis revealed that USP genes primarily respond to drought stress in Oryza sativa, temperature, and drought stress in Zea mays, and cold stress in Arabidopsis thaliana. Gene collinearity analysis can reveal correlations between genes, aiding subsequent in-depth investigations. This study sheds new light on the evolution of USP genes in monocots and dicots and lays the foundation for a better understanding of the biological functions of the USP genes family.

9.
Sci Total Environ ; 935: 173382, 2024 Jul 20.
Article in English | MEDLINE | ID: mdl-38777050

ABSTRACT

With the development of monitoring technology, the variety of ozone precursors that can be detected by monitoring stations has been increased dramatically. And this has brought a great increment of information to ozone prediction and explanation studies. This study completes feature mining and reconstruction of multi-source data (meteorological data, conventional pollutant data, and precursors data) by using a machine learning approach, and built a cross-stacked ensemble learning model (CSEM). In the feature engineering process, this study reconstructed two VOCs variables most associated with ozone and found it works best to use the top seven variables with the highest contribution. The CSEM includes three base models: random forest, extreme gradient boosting tree, and LSTM, learning the parameters of the model under the integrated training of cross-stacking. The cross-stacked integrated training method enables the second-layer learner of the ensemble model to make full use of the learning results of the base models as training data, thereby improving the prediction performance of the model. The model predicted the hourly ozone concentration with R2 of 0.94, 0.97, and 0.96 for mild, moderate, and severe pollution cases, respectively; mean absolute error (MAE) of 4.48 µg/m3, 5.01 µg/m3, and 8.71 µg/m3, respectively. The model predicted ozone concentrations under different NOx and VOCs reduction scenarios, and the results show that with a 20 % reduction in VOCs and no change in NOx in the study area, 75.28 % of cases achieved reduction and 15.73 % of cases got below 200 µg/m3. In addition, a comprehensive evaluation index of the prediction model is proposed in this paper, which can be extended to any prediction model performance comparison and analysis. For practical application, machine learning feature selection and cross-stacked ensemble models can be jointly applied in ozone real-time prediction and emission reduction strategy analysis.

10.
EBioMedicine ; 104: 105155, 2024 May 13.
Article in English | MEDLINE | ID: mdl-38744109

ABSTRACT

BACKGROUND: Despite numerous studies having evaluated the associations between human papillomavirus (HPV) infection and risk of specific cancers other than anogenital tract and oropharyngeal, the findings are inconsistent and the quality of evidence has not been systematically quantified. We aimed to summarise the existing evidence as well as to evaluate the strength and credibility of these associations. METHODS: We conducted an umbrella review of systematic reviews and meta-analyses of observational studies. PubMed, EMBASE, and Web of Science were searched from inception to March 2024. Studies with systematic reviews and meta-analyses that examined associations between HPV or HPV-associated genotypes infection and specific cancers were eligible for this review. The quality of the methodology was evaluated using A Measurement Tool to Assess systematic Reviews (AMSTAR). The credibility of the evidence was assessed using GRADE. The protocol was preregistered with PROSPERO (CRD42023439070). FINDINGS: The umbrella review identified 31 eligible studies reporting 87 associations with meta-analytic estimates, including 1191 individual studies with 336,195 participants. Of those, 29 (93.5%) studies were rated as over moderate quality by AMSTAR. Only one association indicating HPV-18 infection associated with an increased risk of breast cancer (odds ratio [OR] = 3.48, 95% confidence interval [CI] = 2.24-5.41) was graded as convincing evidence. There were five unique outcomes identified as highly suggestive evidence, including HPV infection increased the risk of oral squamous cell carcinoma (OR = 7.03, 95% CI = 3.87-12.76), oesophageal cancer (OR = 3.32, 95% CI = 2.54-4.34), oesophageal squamous cell carcinoma (OR = 2.69, 95% CI = 2.05-3.54), lung cancer (OR = 3.60, 95% CI = 2.59-5.01), and breast cancer (OR = 6.26, 95% CI = 4.35-9.00). According to GRADE, one association was classified as high, indicating that compared with the controls in normal tissues, HPV infection was associated with an increased risk of breast cancer. INTERPRETATION: The umbrella review synthesised up-to-date observational evidence on HPV infection with the risk of breast cancer, oral squamous cell carcinoma, oesophageal cancer, oesophageal squamous cell carcinoma, and lung cancer. Further larger prospective cohort studies are needed to verify the associations, providing public health recommendations for prevention of disease. FUNDING: National Key Research and Development Program of China, Natural Science Foundation of China, Outstanding Scientific Fund of Shengjing Hospital of China Medical University, and 345 Talent Project of Shengjing Hospital of China Medical University.

11.
Food Chem ; 453: 139637, 2024 Sep 30.
Article in English | MEDLINE | ID: mdl-38781897

ABSTRACT

Herein, a novel multifunctional enzyme ß-glucosidase/xylanase/feruloyl esterase (GXF) was constructed by fusion of ß-glucosidase and bifunctional xylanase/feruloyl esterase. The activities of ß-glucosidase, xylanase, feruloyl esterase and acetyl xylan esterase displayed by GXF were 67.18 %, 49.54 %, 38.92 % and 23.54 %, respectively, higher than that of the corresponding single functional enzymes. Moreover, the GXF performed better in enhancing aroma and quality of Longjing tea than the single functional enzymes and their mixtures. After treatment with GXF, the grassy and floral odors of tea infusion were significantly improved. Moreover, GXF treatment could improve concentrations of flavonoid aglycones of myricetin, kaempferol and quercetin by 68.1-, 81.42- and 77.39-fold, respectively. In addition, GXF could accelerate the release of reducing sugars, ferulic acid and xylo-oligosaccharides by 9.48-, 8.25- and 4.11-fold, respectively. This multifunctional enzyme may have potential applications in other fields such as food production and biomass degradation.


Subject(s)
Camellia sinensis , Carboxylic Ester Hydrolases , Tea , beta-Glucosidase , Carboxylic Ester Hydrolases/chemistry , Carboxylic Ester Hydrolases/metabolism , beta-Glucosidase/chemistry , beta-Glucosidase/metabolism , Camellia sinensis/chemistry , Camellia sinensis/enzymology , Tea/chemistry , Endo-1,4-beta Xylanases/chemistry , Endo-1,4-beta Xylanases/metabolism , Odorants/analysis
13.
Appl Opt ; 63(8): 1962-1970, 2024 Mar 10.
Article in English | MEDLINE | ID: mdl-38568636

ABSTRACT

In this paper, a dual-band terahertz metamaterial sensor based on aluminum and silicon is proposed and simulated. The aluminum surface, which is deposited on a silicon substrate, is made of a C-shaped frame resonator, a rectangular beam, and a cross. The device is insensitive to the change of incident angle in the range of 0°-30°, which shows the great transmission stability of the sensor. By examining the resonance frequency shift, it is shown that 98.3 and 237.5 GHz/RIU refractive index sensitivity can be obtained near 1.76 and 2.404 THz transmission dips of the proposed structure, respectively. The two dips can be used to sense analytes in different refractive index ranges, respectively. For Dip 1 at 1.76 THz, the range is 1.0-1.6. For Dip 2 at 2.404 THz, the range is 1.6-2.0. Different from traditional multi-band metamaterial sensors, two dips generated by the proposed device can measure continuous and non-multiplexed refractive index ranges, respectively. Because the resonance frequencies of matters are different, such a characteristic enables the device to measure different types of analyte using the appropriate resonant peak. A central-relief design is then proposed based on perturbation theory to further improve its sensing performance. The aluminum cross is covered by polyimide, which can interfere with the scattering field on the metal surface and affect the transmission results. For both transmission dips, the optimized structure realizes higher sensitivities of 111.7 GHz/RIU and 262.5 GHz/RIU, respectively. More significantly, the optimized structure also has the characteristic of a wide and non-multiplexed refractive index range. In addition, the effects of analyte thickness and polyimide layer thickness on sensor performance are also discussed. The proposed structure opens up new prospects in the design of multiple-band terahertz metamaterial sensors. It can also meet the sensing needs of biomedical, environmental monitoring, and industrial manufacturing.

15.
Comput Biol Med ; 174: 108450, 2024 May.
Article in English | MEDLINE | ID: mdl-38608325

ABSTRACT

Magnetic resonance imaging (MRI) is a non-invasive medical imaging technique that provides high-resolution 3D images and valuable insights into human tissue conditions. Even at present, the refinement of denoising methods for MRI remains a crucial concern for improving the quality of the images. This study aims to improve the prefiltered rotationally invariant non-local principal component analysis (PRI-NL-PCA) algorithm. We relaxed the original restrictions using particle swarm optimization to determine optimal parameters for the PCA part of the original algorithm. In addition, we adjusted the prefiltered rotationally invariant non-local mean (PRI-NLM) part by traversing the signal intensities of voxels instead of their spatial positions to reduce duplicate calculations and expand the search volume to the whole image when estimating voxels' signal intensities. The new method demonstrated superior denoising performance compared to the original approach. Moreover, in most cases, the new algorithm ran faster. Furthermore, our proposed method can also be applied to process Gaussian noise in natural images and has the potential to enhance other NLM-based denoising algorithms.


Subject(s)
Algorithms , Magnetic Resonance Imaging , Signal-To-Noise Ratio , Magnetic Resonance Imaging/methods , Humans , Principal Component Analysis , Brain/diagnostic imaging , Image Processing, Computer-Assisted/methods
16.
Article in English | MEDLINE | ID: mdl-38577897

ABSTRACT

BACKGROUND: Trio exome sequencing can be used to investigate congenital abnormalities identified on pregnancy ultrasound, but its use in an Australian context has not been assessed. AIMS: Assess clinical outcomes and changes in management after expedited genomic testing in the prenatal period to guide the development of a model for widespread implementation. MATERIALS AND METHODS: Forty-three prospective referrals for whole exome sequencing, including 40 trios (parents and pregnancy), two singletons and one duo were assessed in a tertiary hospital setting with access to a state-wide pathology laboratory. Diagnostic yield, turn-around time (TAT), gestational age at reporting, pregnancy outcome, change in management and future pregnancy status were assessed for each family. RESULTS: A clinically significant genomic diagnosis was made in 15/43 pregnancies (35%), with an average TAT of 12 days. Gestational age at time of report ranged from 16 + 5 to 31 + 6 weeks (median 21 + 3 weeks). Molecular diagnoses included neuromuscular and skeletal disorders, RASopathies and a range of other rare Mendelian disorders. The majority of families actively used the results in pregnancy decision making as well as in management of future pregnancies. CONCLUSIONS: Rapid second trimester prenatal genomic testing can be successfully delivered to investigate structural abnormalities in pregnancy, providing crucial guidance for current and future pregnancy management. The time-sensitive nature of this testing requires close laboratory and clinical collaboration to ensure appropriate referral and result communication. We found the establishment of a prenatal coordinator role and dedicated reporting team to be important facilitators. We propose this as a model for genomic testing in other prenatal services.

17.
Front Oncol ; 14: 1345576, 2024.
Article in English | MEDLINE | ID: mdl-38577327

ABSTRACT

Objective: To evaluate the value of a nomogram combined MRI Diffusion Weighted Imaging (DWI) and clinical features to predict the treatment response of Neoadjuvant Chemotherapy (NAC) in patients with osteosarcoma. Methods: A retrospective analysis was conducted on 209 osteosarcoma patients admitted into two bone cancer treatment centers (133 males, 76females; mean age 16.31 ± 11.42 years) from January 2016 to January 2022. Patients were classified as pathological good responders (pGRs) if postoperative histopathological examination revealed ≥90% tumor necrosis, and non-pGRs if <90%. Their clinical features were subjected to univariate and multivariate analysis, and features with statistically significance were utilized to construct a clinical signature using machine learning algorithms. Apparent diffusion coefficient (ADC) values pre-NAC (ADC 0) and post two chemotherapy cycles (ADC 1) were recorded. Regions of interest (ROIs) were delineated from pre-treatment DWI images (b=1000 s/mm²) for radiomic features extraction. Variance thresholding, SelectKBest, and LASSO regression were used to select features with strong relevance, and three machine learning models (Logistic Regression, RandomForest and XGBoost) were used to construct radiomics signatures for predicting treatment response. Finally, the clinical and radiomics signatures were integrated to establish a comprehensive nomogram model. Predictive performance was assessed using ROC curve analysis, with model clinical utility appraised through AUC and decision curve analysis (DCA). Results: Of the 209patients, 51 (24.4%) were pGRs, while 158 (75.6%) were non-pGRs. No significant ADC1 difference was observed between groups (P>0.05), but pGRs had a higher ADC 0 (P<0.01). ROC analysis indicated an AUC of 0.681 (95% CI: 0.482-0.862) for ADC 0 at the threshold of ≥1.37×10-3 mm²/s, achieving 74.7% sensitivity and 75.7% specificity. The clinical and radiomics models reached AUCs of 0.669 (95% CI: 0.401-0.826) and 0.768 (95% CI: 0.681-0.922) respectively in the test set. The combined nomogram displayed superior discrimination with an AUC of 0.848 (95% CI: 0.668-0.951) and 75.8% accuracy. The DCA suggested the clinical utility of the nomogram. Conclusion: The nomogram based on combined radiomics and clinical features outperformed standalone clinical or radiomics model, offering enhanced accuracy in evaluating NAC response in osteosarcoma. It held significant promise for clinical applications.

18.
J Agric Food Chem ; 72(14): 8140-8148, 2024 Apr 10.
Article in English | MEDLINE | ID: mdl-38563232

ABSTRACT

Rebaudioside (Reb) M is an important sweetener with high sweetness, but its low content in Stevia rebaudiana and low catalytic capacity of the glycosyltransferases in heterologous microorganisms limit its production. In order to improve the catalytic efficiency of the conversion of stevioside to Reb M by Saccharomyces cerevisiae, several key issues must be resolved including knocking out endogenous hydrolases, enhancing glycosylation, and extending the enzyme catalytic process. Herein, endogenous glycosyl hydrolase SCW2 was knocked out in S. cerevisiae. The glycosylation process was enhanced by screening glycosyltransferases, and UGT91D2 from S. rebaudiana was identified as the optimum glycosyltransferase. The UDP-glucose supply was enhanced by overexpressing UGP1, and co-expressing UGT91D2 and UGT76G1 achieved efficient conversion of stevioside to Reb M. In order to extend the catalytic process, the silencing information regulator 2 (SIR2) which can prolong the growth cycle of S. cerevisiae was introduced. Finally, combining these modifications produced 12.5 g/L Reb M and the yield reached 77.9% in a 5 L bioreactor with 10.0 g/L stevioside, the highest titer from steviol glycosides to Reb M reported to date. The engineered strain could facilitate the industrial production of Reb M, and the strategies provide references for the production of steviol glycosides.


Subject(s)
Diterpenes, Kaurane , Stevia , Trisaccharides , Saccharomyces cerevisiae/genetics , Uridine Diphosphate , Hydrolases , Glucosides , Glycosyltransferases/genetics , Glycosides , Plant Leaves
19.
Sci Total Environ ; 927: 172468, 2024 Jun 01.
Article in English | MEDLINE | ID: mdl-38615762

ABSTRACT

Aqueous trivalent manganese [Mn(III)], an important reactive intermediate, is ubiquitous in natural surface water containing humic acid (HA). However, the effect of low-molecular-weight organic acids (LMWOAs) on the formation, stability and reactivity of Mn(III) intermediate is still unknown. In this study, six LMWOAs, including oxalic acid (Oxa), salicylic acid (Sal), catechol (Cat), caffeic acid (Caf), gallic acid (Gal) and ethylene diamine tetraacetic acid (EDTA), were selected to investigate the effects of LMWOAs on the degradation of BPA induced by in situ formed Mn(III)-L in the HA/Mn(II) system under light irradiation. The chromophoric constituents of HA could absorb light radiation and generate superoxide radical to promote the oxidation of Mn(II) to form Mn(III), which was further involved in transformation of BPA. Our results implied that different LMWOAs did significantly impact on Mn(III) production and its degradation of BPA due to their different functional group. EDTA, Oxa and Sal extensively increased the Mn(III) concentration from 50 to 100 µM compared to the system without LMWOAs, following the order of EDTA > Oxa > Sal, and also enhanced the degradation of BPA with the similar patterns. In contrast, Cat, Caf and Gal had an inhibitory effect on the formation of Mn(III), which is likely because they consumed the superoxide radicals generated from irradiated HA, resulting in the inhibition of Mn(II) oxidation and further BPA removal. The product identification and theoretical calculation indicated that a single electron transfer process occurred between Mn(III)-L and BPA, forming BPA radicals and subsequent self-coupling products. Our results demonstrated that the LMWOAs with different structures could alter the cycling process of Mn via complexation and redox reactions, which would provide new implications for the removal of organic pollutants in surface water.

20.
Food Chem ; 451: 139435, 2024 Sep 01.
Article in English | MEDLINE | ID: mdl-38678660

ABSTRACT

This study aimed to assess the antioxidant activity of golden chlorella (GoC) and grape pomace (GrP) extracts both in vitro and in pea protein-based extrudates. We hypothesized that GoC/GrP would limit oxidation of proteins in the extrudates compared with commercial antioxidants. The results showed that GoC extract was effective in metal chelation and GrP extract possessed excellent radical scavenging activity and reducing power. Protein oxidation inevitably occurred after low-moisture extrusion in terms of elevated level of protein carbonyls and the gradual loss of thiols. LC-MS/MS revealed that the monoxidation and 4-hydroxynonenal adduction were the major oxidative modifications, and legumin was the most susceptible globulin for oxidation. The GoC/GrP extracts effectively retarded the oxidation progress in extrudates by lower intensity of oxidized peptides, whereas protein electrophoretic profiles remained unaffected. This study highlighted the great potential of GoC/GrP as natural antioxidants in plant-based foods.


Subject(s)
Antioxidants , Oxidation-Reduction , Pisum sativum , Plant Extracts , Proteomics , Antioxidants/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Pisum sativum/chemistry , Vitis/chemistry , Pea Proteins/chemistry , Chlorella/chemistry , Chlorella/metabolism , Tandem Mass Spectrometry , Plant Proteins/chemistry , Plant Proteins/metabolism
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