Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 76
Filtrar
1.
Carbohydr Polym ; 332: 121905, 2024 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-38431412

RESUMO

Glycosaminoglycans (GAGs), as a class of biopolymers, play pivotal roles in various biological metabolisms such as cell signaling, tissue development, cell apoptosis, immune modulation, and growth factor activity. They are mainly present in the colon in free forms, which are essential for maintaining the host's health by regulating the colonization and proliferation of gut microbiota. Therefore, it is important to explain the specific members of the gut microbiota for GAGs' degradation and their enzymatic machinery in vivo. This review provides an outline of GAGs-utilizing entities in the Bacteroides, highlighting their polysaccharide utilization loci (PULs) and the enzymatic machinery involved in chondroitin sulfate (CS) and heparin (Hep)/heparan sulfate (HS). While there are some variations in GAGs' degradation among different genera, we analyze the reputed GAGs' utilization clusters in lactic acid bacteria (LAB), based on recent studies on GAGs' degradation. The enzymatic machinery involved in Hep/HS and CS metabolism within LAB is also discussed. Thus, to elucidate the precise mechanisms utilizing GAGs by diverse gut microbiota will augment our understanding of their effects on human health and contribute to potential therapeutic strategies for diseases.


Assuntos
Microbioma Gastrointestinal , Lactobacillales , Humanos , Glicosaminoglicanos/metabolismo , Bacteroides/metabolismo , Lactobacillales/metabolismo , Heparina , Heparitina Sulfato
2.
Nanomicro Lett ; 16(1): 164, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38546948

RESUMO

Aqueous Zn2+-ion batteries (AZIBs), recognized for their high security, reliability, and cost efficiency, have garnered considerable attention. However, the prevalent issues of dendrite growth and parasitic reactions at the Zn electrode interface significantly impede their practical application. In this study, we introduced a ubiquitous biomolecule of phenylalanine (Phe) into the electrolyte as a multifunctional additive to improve the reversibility of the Zn anode. Leveraging its exceptional nucleophilic characteristics, Phe molecules tend to coordinate with Zn2+ ions for optimizing the solvation environment. Simultaneously, the distinctive lipophilicity of aromatic amino acids empowers Phe with a higher adsorption energy, enabling the construction of a multifunctional protective interphase. The hydrophobic benzene ring ligands act as cleaners for repelling H2O molecules, while the hydrophilic hydroxyl and carboxyl groups attract Zn2+ ions for homogenizing Zn2+ flux. Moreover, the preferential reduction of Phe molecules prior to H2O facilitates the in situ formation of an organic-inorganic hybrid solid electrolyte interphase, enhancing the interfacial stability of the Zn anode. Consequently, Zn||Zn cells display improved reversibility, achieving an extended cycle life of 5250 h. Additionally, Zn||LMO full cells exhibit enhanced cyclability of retaining 77.3% capacity after 300 cycles, demonstrating substantial potential in advancing the commercialization of AZIBs.

3.
Biotechnol Adv ; 71: 108323, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38346597

RESUMO

CRISPR-Cas (Clustered regularly interspaced short palindromic repeats-CRISPR associated proteins) systems are widely distributed in lactic acid bacteria (LAB), contributing to their RNA-mediated adaptive defense immunity. The CRISPR-Cas-based genetic tools have exhibited powerful capability. It has been highly utilized in different organisms, accelerating the development of life science. The review summarized the components, adaptive immunity mechanisms, and classification of CRISPR-Cas systems; analyzed the distribution and characteristics of CRISPR-Cas system in LAB. The review focuses on the development of CRISPR-Cas-based genetic tools in LAB for providing latest development and future trend. The diverse and broad applications of CRISPR-Cas systems in food/probiotic industry are introduced. LAB harbor a plenty of CRISPR-Cas systems, which contribute to generate safer and more robust strains with increased resistance against bacteriophage and prevent the dissemination of plasmids carrying antibiotic-resistance markers. Furthermore, the CRISPR-Cas system from LAB could be used to exploit novel, flexible, programmable genome editing tools of native host and other organisms, resolving the limitation of genetic operation of some LAB species, increasing the important biological functions of probiotics, improving the adaptation of probiotics in complex environments, and inhibiting the growth of foodborne pathogens. The development of the genetic tools based on CRISPR-Cas system in LAB, especially the endogenous CRISPR-Cas system, will open new avenues for precise regulation, rational design, and flexible application of LAB.


Assuntos
Bacteriófagos , Lactobacillales , Sistemas CRISPR-Cas/genética , Tecnologia de Alimentos , Edição de Genes , Bacteriófagos/genética , Lactobacillales/genética
4.
Environ Pollut ; 346: 123660, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38417602

RESUMO

Immobilizing Fe-based nanoparticles on electron-rich biochar has becoming an attractive heterogeneous Fenton-like catalysts (Fe/BC) for wastewater decontamination. However, the insufficient graphitization of biochar causing low electron transfer and by slow H2O2 activation limited its application. Herein, we firstly constructed FeS/biochar composite through all-solid molten salt method (Fe/MSBCs), which can provide strong polarization force and liquid reaction environment to improve carbonization. As expected, the obtained Fe/MSBCs exhibits high surface area and fast interfacial electron transfer between FeS and biochar. More importantly, the partially oxidized FeS (001) facet facilitate H2O2 adsorption and thermodynamically easily decomposition into •OH. Such a synergistic effect endowed them excellent photo-Fenton degradation performance for methyl orange (MO) with large kinetic rate constants (0.079 min-1) and high H2O2 utilization efficiency (95.9%). This study first demonstrated the critical regulatory role of molten salt method in iron-based biochar composites, which provide an alternative for H2O2 activator in water pollutant control.


Assuntos
Elétrons , Peróxido de Hidrogênio , Compostos Ferrosos , Carvão Vegetal , Oxirredução
5.
Angew Chem Int Ed Engl ; 63(11): e202318928, 2024 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-38189767

RESUMO

The Zn//V2 O5 system not only faces the incontrollable growth of zinc (Zn) dendrites, but also withstands the cross-talk effect of by-products produced from the cathode side to the Zn anode, inducing interelectrode talk and aggravating battery failure. To tackle these issues, we construct a rapid Zn2+ -conducting hydrogel electrolyte (R-ZSO) to achieve Zn deposition modulation and side reaction inhibition in Zn//V2 O5 full cells. The polymer matrix and BN exhibit a robust anchoring effect on SO4 2- , accelerating Zn2+ migration and enabling dense Zn deposition behavior. Therefore, the Zn//Zn symmetric cells based on the R-ZSO electrolyte can operate stably for more than 1500 h, which is six times higher than that of cells employing the blank electrolyte. More importantly, the R-ZSO hydrogel electrolyte effectively decouples the cross-talk effects, thus breaking the infinite loop of side reactions. As a result, the Zn//V2 O5 cells using this modified hydrogel electrolyte demonstrate stable operation over 1,000 cycles, with a capacity loss rate of only 0.028 % per cycle. Our study provides a promising gel chemistry, which offers a valuable guide for the construction of high-performance and multifunctional aqueous Zn-ion batteries.

6.
World J Microbiol Biotechnol ; 39(11): 301, 2023 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-37688654

RESUMO

The exopolysaccharides (EPSs) of lactic acid bacteria (LAB) have presented various bioactivities and beneficial characteristics, rendering their vast commercial value and attracting a broad interest of researchers. The diversity of EPS structures contributes to the changes of EPS functions. However, the low yield of EPS of LAB has severely limited these biopolymers' comprehensive studies and applications in different areas, such as functional food, health and medicine fields. The clarification of biosynthesis mechanism of EPS will accelerate the synthesis and reconstruction of EPS. In recent years, with the development of new genetic manipulation techniques, there has been significant progress in the EPS biosynthesis mechanisms in LAB. In this review, the structure of LAB-derived EPSs, the EPS biosynthesis basic pathways in LAB, the EPS biosynthetic gene cluster, and the regulation mechanism of EPS biosynthesis will be summarized. It will focus on the latest progress in EPS biosynthesis regulation of LAB and provide prospects for future related developments.


Assuntos
Lactobacillales , Medicina , Alimento Funcional , Técnicas Genéticas , Lactobacillales/genética , Família Multigênica
7.
J Colloid Interface Sci ; 652(Pt A): 1016-1027, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37639924

RESUMO

Photothermal nanoreactor with rapid charge transfer and improved spectral utilization is a key point in photocatalysis research. Herein, silver sulfide quantum dots (Ag2S QDs) were coating on the surface of porous graphitic carbon nitride nano vesicles (PCNNVs) to form Ag2S/PCNNVs nanoreactors by a simple calcination method for obtaining efficient photothermal-assisted photocatalytic hydrogen (H2) evolution under simulated/real sunlight irradiation. In particularly, the as-prepared optimal 3% Ag2S/PCNNVs sample exhibited the H2 production rate of 34.8 mmol h-1 g-1, which was 3.5 times higher than that of bare PCNNVs. The enhancement of photothermal-assisted activity over the Ag2S/PCNNVs composite system is mainly attributed to the coupling of the photothermal conversion performance of Ag2S QDs and the thermal insulation performance of PCNNVs based on the plasmonic coupling-boosted photothermal nanoreactor. This study presents a promising strategy for the development of high-efficient photothermal-assisted photocatalysts.

8.
Mater Horiz ; 10(5): 1479-1538, 2023 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-37040188

RESUMO

Li7La3Zr2O12 (LLZO)-based solid-state Li batteries (SSLBs) have emerged as one of the most promising energy storage systems due to the potential advantages of solid-state electrolytes (SSEs), such as ionic conductivity, mechanical strength, chemical stability and electrochemical stability. However, there remain several scientific and technical obstacles that need to be tackled before they can be commercialised. The main issues include the degradation and deterioration of SSEs and electrode materials, ambiguity in the Li+ migration routes in SSEs, and interface compatibility between SSEs and electrodes during the charging and discharging processes. Using conventional ex situ characterization techniques to unravel the reasons that lead to these adverse results often requires disassembly of the battery after operation. The sample may be contaminated during the disassembly process, resulting in changes in the material properties within the battery. In contrast, in situ/operando characterization techniques can capture dynamic information during cycling, enabling real-time monitoring of batteries. Therefore, in this review, we briefly illustrate the key challenges currently faced by LLZO-based SSLBs, review recent efforts to study LLZO-based SSLBs using various in situ/operando microscopy and spectroscopy techniques, and elaborate on the capabilities and limitations of these in situ/operando techniques. This review paper not only presents the current challenges but also outlines future developmental prospects for the practical implementation of LLZO-based SSLBs. By identifying and addressing the remaining challenges, this review aims to enhance the comprehensive understanding of LLZO-based SSLBs. Additionally, in situ/operando characterization techniques are highlighted as a promising avenue for future research. The findings presented here can serve as a reference for battery research and provide valuable insights for the development of different types of solid-state batteries.

9.
Biotechnol Lett ; 45(5-6): 639-654, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37010620

RESUMO

OBJECTIVE: Its eps gene cluster, the antioxidant activity and monosaccharide composition of exopolysaccharides, the expression levels of related genes at different fermentations were analyzed for clarifying the exopolysaccharide biosynthesis mechanism of Lactobacillus delbrueckii subsp. bulgaricus LDB-C1. RESULTS: The comparison analysis of eps gene clusters indicated that the gene clusters present diversity and strain specificity. The crude exopolysaccharides from LDB-C1 exhibited a good antioxidant activity. Compared with glucose, fructose, galactose, and fructooligosaccharide, inulin significantly improved the exopolysaccharide biosynthesis. The structures of EPSs were significantly different under different carbohydrate fermentation conditions. Inulin obviously increased the expressions of most EPS biosynthesis related genes at fermentation 4 h. CONCLUSION: Inulin accelerated the beginning of the exopolysaccharide production in LDB-C1, and the enzymes promoted by inulin was beneficial for the accumulation of exopolysaccharide at the whole fermentation process.


Assuntos
Lactobacillus delbrueckii , Lactobacillus delbrueckii/genética , Inulina/metabolismo , Polissacarídeos Bacterianos/metabolismo , Lactobacillus/genética , Antioxidantes/metabolismo , Fermentação
10.
Technol Cancer Res Treat ; 22: 15330338231168763, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37050884

RESUMO

Objective: To compare the 6-dimensional errors of different immobilization devices and body regions based on 3-dimensional cone beam computed tomography for image-guided radiotherapy and to further quantitatively evaluate the impact of rotational corrections on translational shifts and dose distribution based on anthropomorphic phantoms. Materials and Methods: Two hundred ninety patients with cone beam computed tomographies from 3835 fractions were retrospectively analyzed for brain, head & neck, chest, abdomen, pelvis, and breast cases. A phantom experiment was conducted to investigate the impact of rotational errors on translational shifts using cone beam computed tomography and the registration system. For the dosimetry study, pitch rotations were simulated by adjusting the breast bracket by ±2.5°. Roll and yaw rotations were simulated by rotating the gantry and couch in the planning system by ±3.0°, respectively. The original plan for the breast region was designed in the computed tomography image space without rotation. With the same planning parameters, the original plan was transplanted into the image space with different rotations for dose recalculation. The effect of these errors on the breast target and organs at risk was assessed by dose-volume histograms. Results: Most of the mean rotational errors in the breast region were >1°. A single uncorrected yaw of 3° caused a change of 2.9 mm in longitudinal translation. A phantom study for the breast region demonstrated that when the pitch rotations were -2.5° and 2.5° and roll and yaw were both 3°, the reductions in the planning target volumes-V50 Gy were 20.07% and 29.58% of the original values, respectively. When the pitch rotation was +2.5°, the left lung V5 Gy and heart Dmean were 7.49% and 165.76 Gy larger, respectively, than the original values. Conclusions: Uncorrected rotations may cause changes in the values and directions of translational shifts. Rotational corrections may improve the patient setup and dose distribution accuracy.


Assuntos
Radioterapia Guiada por Imagem , Humanos , Radioterapia Guiada por Imagem/métodos , Planejamento da Radioterapia Assistida por Computador/métodos , Estudos Retrospectivos , Tomografia Computadorizada de Feixe Cônico , Tomografia Computadorizada por Raios X/métodos , Erros de Configuração em Radioterapia/prevenção & controle
11.
ACS Appl Mater Interfaces ; 15(14): 18323-18332, 2023 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-37000020

RESUMO

Succinonitrile (SN)-based electrolytes have a great potential for the practical application of all-solid-state lithium-metal batteries (ASSLMBs) due to their high room-temperature ionic conductivity, broad electrochemical window, and favorable thermal stability. Nevertheless, the poor mechanical strength and low stability toward Li metal hinder the further application of SN-based electrolytes to ASSLMBs. In this work, the LiNO3-assisted SN-based electrolytes are synthesized via an in situ thermal polymerization method. With this method, the mechanical problem is negligible, and the stability of the electrolyte enhances tremendously toward Li metal due to the addition of LiNO3. The LiNO3-assisted electrolytes exhibit a high ionic conductivity of 1.4 mS cm-1 at 25 °C, a wide electrochemical window (0-4.5 V vs Li+/Li), and excellent interfacial compatibility with Li (stable for over 2000 h at a current density of 0.1 mA cm-1). The LiFePO4/Li cells with the LiNO3-assisted electrolytes present significantly enhanced rate capability and cycling performance compared to the control group. NCM622/Li batteries also exhibit good cycling and rate performances with a voltage range of 3.0 to 4.4 V. Furthermore, ex situ SEM and XPS are employed. A compact interface is observed on Li anode after cycling, and the polymerization of SN is found to be suppressed. This paper will promote the development of practical application of SN-based ASSLMBs.

12.
Biochem Biophys Res Commun ; 638: 155-162, 2023 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-36459879

RESUMO

Moderate acute stress responses are beneficial for adaptation and maintenance of homeostasis. Exposure of male rat to stress induces effects in the bed nucleus of the stria terminalis (BNST), for it can be activated by the same stimuli that induce activation of the hypothalamic-pituitary-adrenal axis. However, the underlying mechanism of the BNST on male stress reactivity remains unclear. In this study, we explored whether systematic administration of dexmedetomidine (DEXM) altered the acute stress reactivity through its effect on the BNST. Male Sprague-Dawley rats in the stress (STRE) group, DEXM group, and the DEXM + GSK-650394 (GSK, an antagonist of serum- and glucocorticoid-inducible kinase 1 (SGK1)) group, except those in the vehicle (VEH) group, underwent 1-h restraint plus water-immersion (RPWI) exposure. All the rats proceeded the open field test (OFT) 24 h before RPWI and 1 h after RPWI. After the second OFT, the rats received VEH, DEXM (75 µg/kg i.p.), or were pretreated with GSK (2 µM i.p.) 0.5 h ahead of DEXM respectively. The third OFT was conducted 6 h after drug administration and then the rats were sacrificed. The rats that experienced RPWI showed dramatically elevated serum corticosterone (CORT), multiplied neuronal nitric oxide synthase (nNOS) and SGK1 in the BNST, and terrible OFT behavior. We discovered when the nNOS and SGK1 were decreased in the rat BNST through DEXM treatment, the serum CORT was reduced and the OFT manifestation was ameliorated, whereas these were restrained by GSK application. Our results reveal that modest interventions to SGK1 and nNOS in the BNST improve the male rat reactivity to acute stress, and DEXM was one modulator of these effects.


Assuntos
Dexmedetomidina , Núcleos Septais , Ratos , Masculino , Animais , Núcleos Septais/metabolismo , Glucocorticoides/farmacologia , Ratos Sprague-Dawley , Óxido Nítrico Sintase Tipo I/metabolismo , Dexmedetomidina/farmacologia , Sistema Hipotálamo-Hipofisário/metabolismo , Estresse Psicológico , Sistema Hipófise-Suprarrenal/metabolismo , Corticosterona
13.
Adv Mater ; 35(8): e2209210, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36482825

RESUMO

Primary lithium fluorinated graphite (Li/CFx ) batteries with superior energy density are an indispensable energy supply for multiple fields but suffer from sluggish reaction kinetics of the CFx cathode. Designing composite cathodes emerges as a solution to this problem. Despite the optimal composite component for CFx , the manganese oxide family represented by MnO2 is still faced with an intrinsic electronic conductivity bottleneck, which severely limits the power density of the composite cathode. Here, a cation-induced high-dimensional constraining strategy from the perspective of ligand-field stacking structure topological design, which breaks the molecular orbital hybridization of pristine semiconductive oxides to transform them into the high-conductivity metallic state while competitively maintaining structural stability, is proposed. Through first-principles phase diagram calculations, mixed-valent Mn5 O8 ( Mn 2 2 + Mn 3 4 + O 8 ${\rm{Mn}}_2^{2 + }{\rm{Mn}}_3^{4 + }{{\rm{O}}_8}$ ) is explored as an ideal high-dimensional constraining material with satisfied conductivity and large-scale production feasibility. Experiments demonstrate that the as-proposed CFx  @ Mn5 O8 composite cathode achieves 2.36 times the power density (11399 W kg-1 ) of pristine CFx and a higher CFx conversion ratio (86%). Such a high-dimensional field-constraining strategy is rooted in the established four-quadrant electronic structure tuning framework, which fundamentally changes the orbital symmetry under the ligand field to overcome the common conductivity challenge of wide transition metal oxide materials.

14.
Turk J Pediatr ; 64(4): 632-639, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36082637

RESUMO

BACKGROUND: To find the predictor of optimal surgical timing for neonatal necrotizing enterocolitis (NEC) patients by analyzing the risk factors of conservative treatment and surgical therapy. METHODS: Data were collected from 184 NEC patients (Surgery, n=41; conservative treatment, n=143) between the years 2015 and 2019. Data were analyzed by univariate analysis, and multivariate binary logistic regression analysis. RESULTS: Univariate analysis showed that statistically significant differences between the surgery and conservative treatment groups. The results of multivariate Logistic regression analysis indicated intestinal wall thickening by B-ultrasound and gestational age were independent factors to predict early surgical indications of NEC (p < 0.05). The true positive rate, false positive rate, true negative rate and false negative rate in the diagnosis of necrotic bowel perforation guided by DAAS (Duke abdominal X-ray score) ≥7 and MD7 (seven clinical metrics of metabolic derangement) ≥3 were 12.8%, 0.0%, 100.0% and 87.2%, respectively. CONCLUSIONS: In summary, the ultrasound examination in NEC children showing thickening intestinal wall and poor intestinal peristalsis indicated for early operation.


Assuntos
Enterocolite Necrosante , Doenças do Recém-Nascido , Perfuração Intestinal , Criança , Enterocolite Necrosante/diagnóstico por imagem , Enterocolite Necrosante/cirurgia , Idade Gestacional , Humanos , Recém-Nascido , Doenças do Recém-Nascido/diagnóstico por imagem , Doenças do Recém-Nascido/cirurgia , Perfuração Intestinal/diagnóstico por imagem , Perfuração Intestinal/cirurgia , Radiografia Abdominal , Estudos Retrospectivos
15.
Biomed Res Int ; 2022: 5053204, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35761975

RESUMO

Prostate carcinoma (PC) is a disease of the male genitourinary system and a relatively common malignant tumor. In order to investigate the disparities in the expression of microRNA-323 (miR-323), microRNA-409-3p (miR-409-3p), and vascular endothelial growth factor (VEGF) in prostate carcinoma with different clinicopathological features and analyze their correlation with prognosis. Thirty-two sufferers with prostate carcinoma and forty-three sufferers with benign prostatic hyperplasia are included. The results show that the detection of miR-323, miR-409-3p, and VEGF scales can provide reference value for clinical guidance of prostate carcinoma prognosis.


Assuntos
Carcinoma , MicroRNAs , Neoplasias da Próstata , Fator A de Crescimento do Endotélio Vascular , Proliferação de Células , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , MicroRNAs/genética , Prognóstico , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/genética , Ultrassonografia , Fator A de Crescimento do Endotélio Vascular/genética
16.
Ying Yong Sheng Tai Xue Bao ; 33(6): 1686-1692, 2022 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-35729148

RESUMO

In recent years, a variety of important fishery resources in China's coastal waters have declined. Octopus ocellatus has the characteristics of short life cycle and rapid growth, with great contributions to fisheries of China's coastal waters. However, we know little about the habitat distribution characteristics of O. ocellatus and its relationship with environmental factors, which is not conducive to better protection and utilization of its resources. Here, we analyzed the distribution characteristics of O. ocellatus and its relationship with environmental factors using three machine learning methods, i.e., random forest model, artificial neural network model, and generalized boosted regression models, based on the survey data of fishery resources and habitat in Haizhou Bay during spring of 2011 and 2013-2017. Among the three models, random forest model had great advantages in the fitting effect and prediction ability. The model analysis results showed that sea bottom temperature, seawater depth and sea bottom salinity had significant effects on the habitat distribution of O. ocellatus. The relative resource density of O. octopus increased first and then decreased with the increases of sea bottom temperature, seawater depth, and sea bottom salinity. Based on environmental data simulated by the FVCOM model, we predicted the habitat distribution of O. ocellatus in Haizhou Bay using random forest model and found that O. ocellatus was mainly distributed in the area between 34.5°-35.8° N and 119.7°-121° E.


Assuntos
Octopodiformes , Animais , Baías , China , Ecossistema , Pesqueiros , Estações do Ano
17.
J Sci Food Agric ; 102(12): 5321-5332, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35318677

RESUMO

BACKGROUND: Food grade Streptococcus thermophilus produces biological exopolysaccharides (EPSs) with great potential with respect to catering for higher health-promoting demands; however, how S. thermophilus regulates the biosynthesis of EPS is not completely understood, decelerating the application of these polymers. In our previous study, maltose, soy peptone and initial pH were three key factors of enhancing EPS yield in S. thermophilus CS6. Therefore, we aimed to investigate the regulating mechanisms of EPS biosynthesis in S. thermophilus CS6 via the method of comparative transcriptome and differential carbohydrate metabolism. RESULTS: Soy peptone addition (58.6 g L-1 ) and a moderate pH (6.5) contributed to a high bacterial biomass and a high EPS yield (407 mg L-1 ). Maltose, soy peptone and initial pH greatly influenced lactose utilization in CS6. Soy peptone addition induced a high accumulation of mannose and arabinose in intracellular CS6, differential monosaccharide composition (mannose, glucose and arabinose) in EPS and high radical [2,2-diphenyl-1-picrylhydrazyl, superoxide and 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)] scavenging activities. Carbohydrate transportation, sugar activation and eps cluster-associated genes were differentially expressed to regulate EPS biosynthesis. Correlation analysis indicated high production of EPSs depended on high expression of lacS, galPMKUTE, pgm, gt2-5&4-1 and epsLM. CONCLUSION: The production of antioxidant EPS in S. thermophilus CS6 depended on the regulation of galactose metabolism cluster and eps cluster. The present study recommends a new approach for enhancing EPS production by transcriptomic regulation for further food and health application of EPS. © 2022 Society of Chemical Industry.


Assuntos
Streptococcus thermophilus , Transcriptoma , Antioxidantes/metabolismo , Arabinose , Perfilação da Expressão Gênica , Maltose , Manose/metabolismo , Peptonas/metabolismo , Polissacarídeos Bacterianos/química , Streptococcus thermophilus/genética , Streptococcus thermophilus/metabolismo
18.
J Colloid Interface Sci ; 614: 677-689, 2022 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-35124295

RESUMO

The enhancement of the self-cleaning ability of photocatalytic membranes and their degradation efficiency over tetracycline (TC) still remains a challenge. In this study, an alternative silver vanadate quantum dots (AgVO3 QDs) doped reduced graphene oxide (RGO) and graphitic carbon nitride (C3N4) nanocomposites modified polyvinylidene fluoride (PVDF) membrane (AgVO3/RGO/C3N4-PVDF) was successfully fabricated to enhance the photocatalytic activity. The AgVO3/RGO/C3N4 nanocomposites were functioned as the active component for the photocatalytic membrane. The unique Z-scheme heterostructure of AgVO3/RGO/C3N4 and the porous PVDF framework synergistically enhanced the separation and transport efficiency of photogenerated carriers and facilitated the interaction between the photocatalyst and the pollutant. As a result, the degradation efficiency of TC for the AgVO3/RGO/C3N4-PVDF reached 88.53% within 120 min, which was higher than those of the binary component membranes (64.8% for RGO/C3N4-PVDF and 79.18% AgVO3/C3N4-PVDF). In addition, AgVO3/RGO/C3N4-PVDF exhibited high permeability (1977 L·m-2·h-1·bar-1) and excellent antifouling activity. Under visible-light irradiation, the flux recovery rate (FRR) increased from 92.4% to 99.1%. Furthermore, AgVO3/RGO/C3N4-PVDF could reject 97.4% of Escherichia coli (E. coli) owning to its self-cleaning capacity, and eliminated the E. coli under visible-light irradiation trough the photogeneration of h+. This study highlights a highly efficient photocatalytic membrane based on a Z-scheme heterostructure, which may have a great potential application in practical wastewater treatment.


Assuntos
Pontos Quânticos , Catálise , Escherichia coli , Polímeros de Fluorcarboneto , Grafite , Compostos de Nitrogênio , Polivinil , Compostos de Prata , Vanadatos
19.
Brain Res Bull ; 180: 31-37, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-34979237

RESUMO

An ongoing global pandemic, the coronavirus disease 2019 is posing threat to people all over the world. The association between COVID-19 and the risk of ischemic stroke remains unclear. This study systematically reviewed published studies and conducted meta-analysis to evaluate the association between the risk of ischemic stroke and COVID-19. This study was conducted according to guidelines from the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The protocol used in this study had been registered in the International Prospective Register of Systematic Reviews. EMBASE, PubMed, Cochrane Library and Web of Science were searched from 1st December 2019-19th February 2021. This systematic review and meta-analysis analysed the combined effect estimations based on odds ratios (OR) with the random-effects model. Four studies were screened from 31,634 participants including 171 COVID-19 positive patients with ischemic stroke were included. The mean age of COVID-19 positive patients with ischemic stroke was 69.45 years (Range: 63-77 years) and the male patients were 56%. Countries covered by these articles were USA, Italy and France. Three of the articles were retrospective cohort studies and one was prospective cohort study. Our analysis revealed that the risk of ischemic stroke (combined OR: 2.41; 95% CI: 1.08-5.38) was significantly increased. Four included studies were significantly heterogeneous (I2 = 75.2%, P = 0.007). Significant association between the risk of ischemic stroke and COVID-19 was observed in the North America group (combined OR: 2.90; 95% CI: 0.45-18.80, I2 = 89.60%, P = 0.002). This study found that the risk for ischemic stroke was increased in COVID-19 patients, especially in patients from North America. Further studies with larger sample sizes that include different ethnic populations are required to confirm our analysis.


Assuntos
Isquemia Encefálica/epidemiologia , COVID-19/epidemiologia , AVC Isquêmico/epidemiologia , Idoso , Isquemia Encefálica/diagnóstico , COVID-19/diagnóstico , Feminino , Humanos , AVC Isquêmico/diagnóstico , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Fatores de Risco
20.
Int J Mol Sci ; 22(24)2021 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-34948249

RESUMO

Lactiplantibacillus plantarum has a strong carbohydrate utilization ability. This characteristic plays an important role in its gastrointestinal tract colonization and probiotic effects. L. plantarum LP-F1 presents a high carbohydrate utilization capacity. The genome analysis of 165 L. plantarum strains indicated the species has a plenty of carbohydrate metabolism genes, presenting a strain specificity. Furthermore, two-component systems (TCSs) analysis revealed that the species has more TCSs than other lactic acid bacteria, and the distribution of TCS also shows the strain specificity. In order to clarify the sugar metabolism mechanism under different carbohydrate fermentation conditions, the expressions of 27 carbohydrate metabolism genes, catabolite control protein A (CcpA) gene ccpA, and TCSs genes were analyzed by quantitative real-time PCR technology. The correlation analysis between the expressions of regulatory genes and sugar metabolism genes showed that some regulatory genes were correlated with most of the sugar metabolism genes, suggesting that some TCSs might be involved in the regulation of sugar metabolism.


Assuntos
Metabolismo dos Carboidratos/fisiologia , Lactobacillus plantarum/metabolismo , Fermentação , Lactobacillaceae/metabolismo , Lactobacillus/metabolismo , Probióticos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...