36 research outputs found

    DNA damage strength modulates a bimodal switch of p53 dynamics for cell-fate control

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    Background: The p53 pathway is differentially activated in response to distinct DNA damage, leading to alternative phenotypic outcomes in mammalian cells. Recent evidence suggests that p53 expression dynamics play an important role in the differential regulation of cell fate, but questions remain as to how p53 dynamics and the subsequent cellular response are modulated by variable DNA damage. Results: We identified a novel, bimodal switch of p53 dynamics modulated by DNA-damage strength that is crucial for cell-fate control. After low DNA damage, p53 underwent periodic pulsing and cells entered cell-cycle arrest. After high DNA damage, p53 underwent a strong monotonic increase and cells activated apoptosis. We found that the damage dose-dependent bimodal switch was due to differential Mdm2 upregulation, which controlled the alternative cell fates mainly by modulating the induction level and pro-apoptotic activities of p53. Conclusions: Our findings not only uncover a new mode of regulation for p53 dynamics and cell fate, but also suggest that p53 oscillation may function as a suppressor, maintaining a low level of p53 induction and pro-apoptotic activities so as to render cell-cycle arrest that allows damage repair.BiologySCI(E)10ARTICLEnull1

    Study on the Dynamics of Differential Metabolites of Pu-erh Tea Fermented by Exogenous Added Bacteria

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    In order to explore the role of exogenous bacteria in the fermentation process of Pu-erh tea and its impact on tea quality, the present study aimed to explore the differences in metabolite changes during fermentation of Pu-erh tea treated with different bacterial strains. To achieve this, non-targeted metabolomics technology was employed, which was combined with multivariate statistical analysis and differential heat maps. The study analyzed the flavonoids, alkaloids, and terpenoids present in the tea samples. The H group was found to have a fruity and sweet aroma, a bright red soup color, and a strong and sweet taste. The A group had a strong floral and honey aroma, a bright red soup color, and a strong and sweet aftertaste. The R group had a fruity and milky aroma, a bright yellow soup color, and a strong but astringent and bitter taste. These differences in quality were found to be related to the levels of metabolites such as malvidin, genkwanin, catechins, caffeine, and lactucin. The study provided preliminary insights into the differences in metabolite content during the fermentation of Pu-erh tea with different bacterial strains, which can have varying effects on the taste, aroma, and soup color of the tea. The findings of this study could provide theoretical assistance for future Pu-erh tea fermentation

    Isolation and extraction of glansreginin A from walnut meal and its effect on the proliferation of 3T3-L1 cells

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    Abstract Glansreginin A is an indicative component in walnut and is abundant in walnut meal. The aim of this study was to isolate and purify glansreginin A from the walnut meal, and to investigate the weight loss and lipid-lowering potential of glansreginin A by studying the effect of glansregin A on the proliferation of 3T3-L1 preadipocytes. Firstly, the response surface methodology was used to effectively improve the extraction yield of glansreginin A. The maximum extraction rate of glansreginin A was 0.363%, and the optimal extraction process conditions were determined. In addition, the lipid-lowering activity of glansreginin A was investigated by cell experiments. The results showed that glansreginin A could inhibit the proliferation of 3T3-L1 preadipocytes in a dose-dependent manner. And cell cycle of different groups of cells treated with glansreginin A was also measured using flow cytometry. The results showed most of the cells were blocked in G0/G1 phase and significantly decreased in S phase. These results suggest that glansreginin A could inhibit the proliferation of 3T3-L1 preadipocytes by causing cell cycle arrest. These findings provided a theoretical basis for the future research of glansreginin A and the development of slimming and fat-reducing foods

    Expression and characterization of a protease-resistant β-d-fructofuranosidase BbFFase9 gene suitable for preparing invert sugars from soybean meal

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    A novel gene (BbFFase9), with an ORF of 1557 bp that encodes β-d-fructofuranosidase from Bifidobacteriaceae bacterium, was cloned and expressed in Escherichia coli. The recombinant protein (BbFFase9) was successfully purified and showed a single band with a molecular mass of 66.2 kDa. This was confirmed as a β-d-fructofuranosidase and exhibited a high specific activity of 209.2 U/mg. Although BbFFase9 was a soluble protein, it exhibited excellent tolerance to proteases such as pepsin, trypsin, acidic protease, neutral protease and Flavourzyme®, indicating its potential applicability in different fields. BbFFase9 exhibited typical invertase activity, and highly catalyzed the hydrolysis of the α1↔2β glycosidic linkage in molecules containing fructosyl moieties but with no detectable fructosyltransferase activity. It was optimally active at pH 6.5 and 50 °C and stable between pH 6.0 and 9.0 at a temperature of up to 45 °C for 30 min BbFFase9 could also effectively hydrolyze galacto-oligosaccharides, which are a flatulence factor in soybean meal, thus releasing new types of product such as melibiose and mannotriose, or degrading them into invert sugars, the sweeter fructose and glucose. This study is the first to report the application of this type of β-d-fructofuranosidase

    A hybrid adaptive-prediction maximum power point tracking method for the smart city with massive photovoltaic

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    The partial shadow condition seriously affects the efficiency of the photovoltaic system in the modern city with dense built and other occlusions. From this, the characteristic curve of the photovoltage system shows multi-peak, which further increases the difficulty of getting photovoltaic systems to operate at maximum efficiency. As an efficient technique, the intelligent optimized maximum power point tracking method relies on initialization information and is difficult to balance the tracking performance. Therefore, a hybrid adaptive-prediction maximum power tracking method is proposed in this paper. Firstly, the neighborhood range of the maximum power points is located by the fuzzy predicted mechanism at the upper layer. Secondly, on the bottom layer, based on improving the Cuckoo search algorithm, the proposed method uses an interpolation function fitting curve to guide the particles to converge accurately on the bottom layer. At the same time, the output voltage of the system under an open loop is directly controlled by the duty cycle of the control signal, which improves the universality of the method. Finally, the simulation results show that the proposed method is superior to other advanced methods in tracking speed and with smaller power oscillations and comparable tracking accuracy, for which the proposed method is suitable for the city with complex environments and dense buildings

    Antibacterial Regularity Mining Beneath the Systematic Activity Database of Lipopeptides Brevilaterins: An Instructive Activity Handbook for Its Food Application

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    Bacterial contamination is a primary threat to food safety. Therefore, the persistent development of natural antibacterial agents has become essential work. The present essay attempts to establish a systematic antibacterial activity database to instruct the food application of brevilaterins, promising antibacterial lipopeptides from Brevibacillus laterosporus S62-9. Minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) were systematically collected from 43 species of standard bacteria and 140 strains of isolated bacteria (food spoilage bacteria and antibiotic-resistant bacteria) using a broth dilution method. The results showed that brevilaterins performed a broad-spectrum inhibitory (0.5~128 μg/mL) and bactericidal activity (1~256 μg/mL), especially efficient against Gram-positive bacteria and spoilage bacteria from grain products. Moreover, brevilaterins not only inhibit and kill multiple antibiotic-resistant bacteria but do not readily develop resistance, with a small specific value of MBC/MIC (1~8). Furthermore, brevilaterins would interact with negatively charged sodium dodecyl sulfate and bind amphipathic soybean phospholipid with an affinity constant of KD = 4.70 × 10−4 M. No significant activity difference was found between brevilaterin B and brevilaterin C. Collectively, this work contributed rich antibacterial data of brevilaterins and revealed the antibacterial regularity beneath these data, which can be used as an activity handbook to instruct their application in food safety

    Conventional dendritic cell 2 links the genetic causal association from allergic asthma to COVID-19: a Mendelian randomization and transcriptomic study

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    Abstract Recent evidence suggests that allergic asthma (AA) decreases the risk of Coronavirus Disease 2019 (COVID-19). However, the reasons remain unclear. Here, we systematically explored data from GWAS (18 cohorts with 11,071,744 samples), bulk transcriptomes (3 cohorts with 601 samples), and single-cell transcriptomes (2 cohorts with 29 samples) to reveal the immune mechanisms that connect AA and COVID-19. Two-sample Mendelian randomization (MR) analysis identified a negative causal correlation from AA to COVID-19 hospitalization (OR = 0.968, 95% CI 0.940–0.997, P = 0.031). This correlation was bridged through white cell count. Furthermore, machine learning identified dendritic cells (DCs) as the most discriminative immunocytes in AA and COVID-19. Among five DC subtypes, only conventional dendritic cell 2 (cDC2) exhibited differential expression between AA/COVID-19 and controls (P < 0.05). Subsequently, energy metabolism, intercellular communication, cellular stemness and differentiation, and molecular docking analyses were performed. cDC2s exhibited more differentiation, increased numbers, and enhanced activation in AA exacerbation, while they showed less differentiation, reduced number, and enhanced activation in severe COVID-19. The capacity of cDC2 for differentiation and SARS-CoV-2 antigen presentation may be enhanced through ZBTB46, EXOC4, TLR1, and TNFSF4 gene mutations in AA. Taken together, cDC2 links the genetic causality from AA to COVID-19. Future strategies for COVID-19 prevention, intervention, and treatment could be stratified according to AA and guided with DC-based therapies. Graphical Abstrac

    Dietary Effect of <i>Brevibacillus laterosporus</i> S62-9 on Chicken Meat Quality, Amino Acid Profile, and Volatile Compounds

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    Probiotics are being used in diets to improve the quality of chicken meat. The aim of the study was to investigate the effects of dietary supplementation with Brevibacillus laterosporus S62-9 microbial agent on the meat quality, amino acids, and volatile compounds of chicken. The experiment was carried out with 160 1-day-old Arbor Acres male broiler chickens, rearing for 42 d. The chickens were randomly divided into two groups of 8 replicates each, with 10 chickens in each group. No supplement was added to the basal diet in the control group and Brevibacillus laterosporus S62-9 microbial agent was added to the diet of the experimental group. At the end of the experiment, the meat quality, meat chemical composition, amino acid composition, and volatile compounds of chicken were determined. The results showed that pH (p p p p p p Brevibacillus laterosporus S62-9 microbial agent can be used as a novel and effective feed supplement to improve the nutritional quality and flavor characteristics of broilers

    Prevalence and burden of illness of treated hemolytic neonatal hyperbilirubinemia in a privately insured population in the United States

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    Abstract Background Prevalence of hemolytic neonatal hyperbilirubinemia (NHB) is not well characterized, and economic burden at the population level is poorly understood. This study evaluated the prevalence, clinical characteristics, and economic burden of hemolytic NHB newborns receiving treatment in U.S. real-world settings. Methods This cohort study used administrative claims from 01/01/2011 to 08/31/2017. The treated cohort had hemolytic NHB diagnosis and received phototherapy, intravenous immunoglobulin, and/or exchange transfusions. They were matched with non-NHB newborns who had neither NHB nor related treatments on the following: delivery hospital/area, gender, delivery route, estimated gestational age (GA), health plan eligibility, and closest date of birth within 5 years. Inferential statistics were reported. Results The annual NHB prevalence was 29.6 to 31.7%; hemolytic NHB, 1.8 to 2.4%; treated hemolytic NHB, 0.46 to 0.55%, between 2011 and 2016. The matched analysis included 1373 pairs ≥35 weeks GA. The treated hemolytic NHB cohort had significantly more birth trauma and hemorrhage (4.5% vs. 2.4%, p = 0.003), vacuum extractor affecting newborn (1.9% vs. 0.8%, p = 0.014), and polycythemia neonatorum (0.8% vs. 0%, p = 0.001) than the matched non-NHB cohort. The treated hemolytic NHB cohort also had significantly longer mean birth hospital stays (4.5 vs. 3.0 days, p < 0.001), higher level 2–4 neonatal intensive care admissions (15.7% vs. 2.4, 15.9% vs. 2.8 and 10.6% vs. 2.5%, respectively, all p < 0.001) and higher 30-day readmission (8.7% vs. 1.7%, p < 0.001). One-month and one-year average total costs of care were significantly higher for the treated hemolytic NHB cohort vs. the matched non-NHB cohort, 14,405vs.14,405 vs. 5527 (p < 0.001) and 21,556vs.21,556 vs. 12,986 (p < 0.001), respectively. The average costs for 30-day readmission among newborns who readmitted were 13,593forthetreatedhemolyticNHBcohortand13,593 for the treated hemolytic NHB cohort and 3638 for the matched non-NHB cohort, p < 0.001. The authors extrapolated GA-adjusted prevalence of treated hemolytic NHB in the U.S. newborn population ≥ 35 weeks GA and estimated an incremental healthcare expenditure of $177.0 million during the first month after birth in 2016. Conclusions The prevalence of treated hemolytic NHB was 4.6–5.5 patients per 1000 newborns. This high-risk hemolytic NHB imposed substantial burdens of healthcare resource utilization and incremental costs on newborns, their caregivers, and the healthcare system
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