76 research outputs found

    Optimization of the preparation process and antioxidant activity analysis of blueberry juice by wet ultrafine grinding process and compound enzymolysis method

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    Objective: This study aimed to optimize the preparation process of blueberry juice and improve its antioxidant activity. Methods: Blueberry juice was prepared using a wet ultrafine grinding process and compound enzymolysis method. Response surface methodology was used to optimize the process parameters and analyze the antioxidant activity of blueberry juice. Results: There were significant differences in the juice yield and active substance content of blueberry juice under different solid-liquid ratios, crushing times, compound enzyme contents, and enzymatic hydrolysis times, with enzymatic hydrolysis time having the most significant impact on juice yield and anthocyanin content. The optimal process parameters for the wet ultrafine grinding process and compound enzymolysis method are solid-liquid ratio of 1∶1.7 (g/g), pulverization time of 8.00 min, compound enzyme content of 0.15%, and enzymatic hydrolysis time of 127 min. Under the control of these process conditions, the blueberry juice yield was 87.89%, with the contents of anthocyanin, total flavonoid and total phenol were 612.04 mg/L, 2.96 g/L and 3.43 g/L, respectively, and its antioxidant capacity was equivalent to 0.3% vitamin C when the addition amount is 1.6 mL. Conclusion: The wet ultrafine grinding process and compound enzymolysis method can improve the juice yield of blueberry juice, maximize the retention of its active substances, and enhance its antioxidant capacity

    Confocal Raman microscopy for assessing effects of preservation methods on symbiotic deep-sea mussel gills

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    Confocal Raman microscopy (CRM) is a powerful tool for biological research, which can provide information regarding the composition and distribution of biomolecules in an in situ, label-free, non-destructive manner and with high spatial resolution. Sample preservation is often an unavoidable step, especially for symbiotic deep-sea samples. Moreover, protocols for the preservation of samples for CRM have not been established and specific effects of different preservation methods on biomolecules have not been studied for relevant samples. In this study, we used deep-sea mussel Gigantidas platifrons, an ideal model in the study of deep-sea symbiosis and investigated the effect of four common preservation methods on the results of CRM imaging and signals. The methods included snap-freeze (SF), SF followed by rapid fixation in methanol (SF-MeOH), 2.5% glutaraldehyde and 2% paraformaldehyde fixation (SF-GP), and 4% paraformaldehyde and alcohol fixation (PS-PA). The results of this study indicate that SF was the most effective method for the comprehensive analysis of the biomolecular composition although the sectioning success rate was relatively low. Moreover, SF-MeOH was found to be effective when SF is not sufficient in obtaining good morphology in sections, or when the effect of chemical bonding on the composition of biomolecules upon SF-MeOH can be neglected. Finally, SF-GP and PS-PA were found to be the most effective methods considering the overall morphological observation. However, they were less suitable for metabolic studies. We believe our results can provide guidance for further studies of Raman on symbiotic deep-sea biological samples. It is of great importance for the wide application of Raman technique

    Determination of abietic acid compounds in poultry by ultra performance liquid chromatography-quadrupole time-of-flight mass spectrometry coupled with dispersive solid phase extraction

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    Objective: An ultra performance liquid chromatography-quadrupole/time-of-flight mass spectrometry (UPLC-Q-TOF/MS) method was established for the determination of abietic acids in poultry. Methods: The samples were extracted with acetonitrile, then salted out and stratified. The supernatant was purified by C18 solid phase extractant and finally determined by UPLC-Q-TOF/MS in ESI negative mode. Results: Abietic acid compounds exhibited a good linear relationship in the concentration range of 10~500 μg/L with good correlation coefficient R2>0.998. The average recoveries of three abietic acid compounds were experiments, the average recovery rate was 87.8%~98.5% with relative standard deviations (RSDs, n=6) of 1.99%~6.71%, at the spiked level of 20, 40, 200 μg/kg. The limits of detection (LODs) were 10 μg/kg and the method limits of quantification (LOQs) were 20 μg/kg. Conclusion: This method was convenient operation, rapid, high recovery and sensitivity and good precision that could meet the determination requirements of three abietic acids in poultry

    Role of the ISKpn element in mediating mgrB gene mutations in ST11 hypervirulent colistin-resistant Klebsiella pneumoniae

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    BackgroundColistin has emerged as a last-resort therapeutic against antibiotic-resistant bacterial infections, particularly those attributed to carbapenem-resistant Enterobacteriaceae (CRE) like CRKP. Yet, alarmingly, approximately 45% of multidrug-resistant Klebsiella pneumoniae strains now manifest resistance to colistin. Through our study, we discerned that the synergy between carbapenemase and IS elements amplifies resistance in Klebsiella pneumoniae, thereby narrowing the existing therapeutic avenues. This underscores the instrumental role of IS elements in enhancing colistin resistance through mgrB disruption.MethodsFrom 2021 to 2023, 127 colistin-resistant Klebsiella pneumoniae isolates underwent meticulous examination. We embarked on an exhaustive genetic probe, targeting genes associated with both plasmid-mediated mobile resistance-encompassing blaKPC, blaNDM, blaIMP, blaVIM, blaOXA-48-like, and mcr-1 to mcr-8-and chromosome-mediated resistance systems, including PhoP/Q, PmrA/B, and mgrB. PCR amplification revealed the presence of virulence-associated genes from the pLVPK plasmid, such as rmpA, rmpA2, iucA, iroB, and peg344. mgrB sequencing was delegated to Sangon Biotech, Shanghai, and the sequences procured were validated using BLAST. Our search for IS elements was navigated through the IS finder portal. Phenotypically, we harnessed broth microdilution (BMD) to ascertain the MICs of colistin. To sketch the clonal lineage of mgrB-mutated CoR-Kp isolates, sophisticated methodologies like MLST and PFGE were deployed. S1-PFGE unraveled the intrinsic plasmids in these isolates. Our battery of virulence assessment techniques ranged from the string test and capsular serotyping to the serum killing assay and the Galleria mellonella larval infection model.ResultsAmong the 127 analyzed isolates, 20 showed an enlarged mgrB PCR amplicon compared to wild-type strains. These emerged over a three-year period: three in 2021, thirteen in 2022, and four in 2023. Antimicrobial susceptibility tests revealed that these isolates consistently resisted several drugs, notably TCC, TZP, CAZ, and COL. Additionally, 85% resisted both DOX and TOB. The MICs for colistin across these strains ranged between 16 to 64 mg/L, with a median of 40 mg/L. From a genetic perspective, MLST unanimously categorized these mgrB-mutated CoR-hvKp isolates as ST11. PFGE further delineated them into six distinct clusters, with clusters A and D being predominant. This distribution suggests potential horizontal and clonal genetic transmission. Intriguingly, every mgrB-mutated CoR-hvKP isolate possessed at least two virulence genes akin to the pLVPK-like virulence plasmid, with iroB and rmpA2 standing out. Their virulence was empirically validated both in vitro and in vivo. A pivotal discovery was the identification of three distinct insertion sequence (IS) elements within or near the mgrB gene. These were:ISKpn26 in eleven isolates, mainly in cluster A, with various insertion sites including +74, +125, and an upstream −35.ISKpn14 in four isolates with insertions at +93, −35, and two upstream at −60.IS903B present in five isolates, marking positions like +74, +125, +116, and −35 in the promoter region. These diverse insertions, spanning six unique locations in or near the mgrB gene, underscore its remarkable adaptability.ConclusionOur exploration spotlights the ISKpn element’s paramount role in fostering mgrB gene mutations in ST11 hypervirulent colistin-resistant Klebsiella pneumoniae. Employing MLST and PFGE, we unearthed two primary genetic conduits: clonal and horizontal. A striking observation was the ubiquitous presence of the KPC carbapenemase gene in all the evaluated ST11 hypervirulent colistin-resistant Klebsiella pneumoniae strains, with a majority also harboring the NDM gene. The myriad mgrB gene insertion locales accentuate its flexibility and the overarching influence of IS elements, notably the pervasive IS5-like variants ISKpn26 and IS903B. Our revelations illuminate the escalating role of IS elements in antibiotic resistance within ST11 hypervirulent colistin-resistant Klebsiella pneumoniae, advocating for innovative interventions to counteract these burgeoning resistance paradigms given their profound ramifications for prevailing treatment modalities

    Incorporation of a machine learning pathological diagnosis algorithm into the thyroid ultrasound imaging data improves the diagnosis risk of malignant thyroid nodules

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    ObjectiveThis study aimed at establishing a new model to predict malignant thyroid nodules using machine learning algorithms.MethodsA retrospective study was performed on 274 patients with thyroid nodules who underwent fine-needle aspiration (FNA) cytology or surgery from October 2018 to 2020 in Xianyang Central Hospital. The least absolute shrinkage and selection operator (lasso) regression analysis and logistic analysis were applied to screen and identified variables. Six machine learning algorithms, including Decision Tree (DT), Extreme Gradient Boosting (XGBoost), Gradient Boosting Machine (GBM), Naive Bayes Classifier (NBC), Random Forest (RF), and Logistic Regression (LR), were employed and compared in constructing the predictive model, coupled with preoperative clinical characteristics and ultrasound features. Internal validation was performed by using 10-fold cross-validation. The performance of the model was measured by the area under the receiver operating characteristic curve (AUC), accuracy, precision, recall, F1 score, Shapley additive explanations (SHAP) plot, feature importance, and correlation of features. The best cutoff value for risk stratification was identified by probability density function (PDF) and clinical utility curve (CUC).ResultsThe malignant rate of thyroid nodules in the study cohort was 53.2%. The predictive models are constructed by age, margin, shape, echogenic foci, echogenicity, and lymph nodes. The XGBoost model was significantly superior to any one of the machine learning models, with an AUC value of 0.829. According to the PDF and CUC, we recommended that 51% probability be used as a threshold for determining the risk stratification of malignant nodules, where about 85.6% of patients with malignant nodules could be detected. Meanwhile, approximately 89.8% of unnecessary biopsy procedures would be saved. Finally, an online web risk calculator has been built to estimate the personal likelihood of malignant thyroid nodules based on the best-performing ML-ed model of XGBoost.ConclusionsCombining clinical characteristics and features of ultrasound images, ML algorithms can achieve reliable prediction of malignant thyroid nodules. The online web risk calculator based on the XGBoost model can easily identify in real-time the probability of malignant thyroid nodules, which can assist clinicians to formulate individualized management strategies for patients

    The effect of parenting styles on adolescent bullying behaviours in China: The mechanism of interpersonal intelligence and intrapersonal intelligence

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    Bullying is a problematic public behaviour of great concern worldwide, which occurs commonly in China. Parenting and emotional intelligence have previously been verified as crucial aspects in determining the bullying behaviours of adolescents. However, evidence of the interactive effect of these vital factors needs to be more extensive. This study attempts to analyze the relationships and mechanisms of parenting on bullying through emotional intelligence, which consists of interpersonal and intrapersonal intelligence. Based on Chinese education panel survey data of 8730 adolescents, this paper used OLS regression and SEM methods to estimate the impact and mechanisms of parenting styles on bullying behaviours among adolescents. High-demand and responsive parenting styles can significantly reduce adolescents' bullying behaviours. Intrapersonal and interpersonal intelligence are important mediating variables, and parenting with high demandingness and high responsiveness can significantly improve the interpersonal intelligence of adolescents, thereby reducing children's bullying behaviour. Although low levels of intrapersonal intelligence would increase bullying behaviours in adolescents, high demandingness and high responsiveness of parenting can significantly improve adolescents' intrapersonal intelligence. Parents can reduce adolescents' bullying behaviours by increasing emotional responses and normative requirements. This result provides a new perspective on the solution to the problem of youth bullying

    Anti-Oxidant and Anti-Melanogenic Properties of Essential Oil from Peel of Pomelo cv. Guan Xi

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    Here, we investigated the anti-oxidant and anti-melanogenic effects of pomelo peel essential oil (PPEO) from pomelo cv. Guan Xi. The volatile chemical composition of PPEO was analyzed with gas chromatography–mass spectrometry (GC/MS). The most abundant component of PPEO was limonene (55.92%), followed by β-myrcene (31.17%), and β-pinene (3.16%). PPEO showed strong anti-oxidant activities against 1,1-diphenyl-2-picryhydrazyl (DPPH) (,2,2'-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) (, and superoxide anion free radicals. Based on the B16 melanoma cell system, the effects of PPEO on the viability and morphology of B16 cells and the production of melanin were evaluated. The results revealed that PPEO at concentrations below 50 μg/mL could decrease the melanin content without affecting cell viability and morphology. Intracellular tyrosinase (TYR) activity and Western blot analysis showed that PPEO could down-regulate the expression level of TYR in B16 cells and dose-dependently inhibit TYR activity (by a maximum of 64.54%). Meanwhile, the main active components responsible for the effect are citral and β-myrcene. In conclusion, PPEO has good anti-oxidant and anti-melanogenic activity, and thus can be widely used as a natural antioxidant in the food, pharmaceutical, and cosmetic industries
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