Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 58
Filtrar
Mais filtros

Base de dados
País/Região como assunto
Tipo de documento
País de afiliação
Intervalo de ano de publicação
1.
Small ; 20(1): e2305161, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-37641192

RESUMO

Single-atom catalysts (SACs) are promising cathode materials for addressing issues faced by lithium-sulfur batteries. Considering the ample chemical space of SACs, high-throughput calculations are efficient strategies for their rational design. However, the high throughput calculations are impeded by the time-consuming determination of the decomposition barrier (Eb ) of Li2 S. In this study, the effects of bond formation and breakage on the kinetics of SAC-catalyzed Li2 S decomposition with g-C3 N4 as the substrate are clarified. Furthermore, a new efficient and easily-obtained descriptor Li─S─Li angle (ALi─S─Li ) of adsorbed Li2 S, different from the widely accepted thermodynamic data for predicting Eb , which breaks the well-known Brønsted-Evans-Polanyi relationship, is identified. Under the guidance of ALi─S─Li , several superior SACs with d- and p-block metal centers supported by g-C3 N4 are screened to accelerate the sulfur redox reaction and fix the soluble lithium polysulfides. The newly identified descriptor of ALi─S─Li can be extended to rationally design SACs for Na─S batteries. This study opens a new pathway for tuning the performance of SACs to catalyze the decomposition of X2 S (X = Li, Na, and K) and thus accelerate the design of SACs for alkaline-chalcogenide batteries.

2.
Nucleic Acids Res ; 50(8): e43, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-34986249

RESUMO

Here, we introduce scMAGIC (Single Cell annotation using MArker Genes Identification and two rounds of reference-based Classification [RBC]), a novel method that uses well-annotated single-cell RNA sequencing (scRNA-seq) data as the reference to assist in the classification of query scRNA-seq data. A key innovation in scMAGIC is the introduction of a second-round RBC in which those query cells whose cell identities are confidently validated in the first round are used as a new reference to again classify query cells, therefore eliminating the batch effects between the reference and the query data. scMAGIC significantly outperforms 13 competing RBC methods with their optimal parameter settings across 86 benchmark tests, especially when the cell types in the query dataset are not completely covered by the reference dataset and when there exist significant batch effects between the reference and the query datasets. Moreover, when no reference dataset is available, scMAGIC can annotate query cells with reasonably high accuracy by using an atlas dataset as the reference.


Assuntos
Análise de Célula Única , Análise de Sequência de RNA/métodos , Análise de Célula Única/métodos , Sequenciamento do Exoma
3.
Sensors (Basel) ; 24(3)2024 Jan 28.
Artigo em Inglês | MEDLINE | ID: mdl-38339567

RESUMO

The point cloud segmentation method plays an important role in practical applications, such as remote sensing, mobile robots, and 3D modeling. However, there are still some limitations to the current point cloud data segmentation method when applied to large-scale scenes. Therefore, this paper proposes an adaptive clustering segmentation method. In this method, the threshold for clustering points within the point cloud is calculated using the characteristic parameters of adjacent points. After completing the preliminary segmentation of the point cloud, the segmentation results are further refined according to the standard deviation of the cluster points. Then, the cluster points whose number does not meet the conditions are further segmented, and, finally, scene point cloud data segmentation is realized. To test the superiority of this method, this study was based on point cloud data from a park in Guilin, Guangxi, China. The experimental results showed that this method is more practical and efficient than other methods, and it can effectively segment all ground objects and ground point cloud data in a scene. Compared with other segmentation methods that are easily affected by parameters, this method has strong robustness. In order to verify the universality of the method proposed in this paper, we test a public data set provided by ISPRS. The method achieves good segmentation results for multiple sample data, and it can distinguish noise points in a scene.

4.
Plant Foods Hum Nutr ; 79(1): 98-105, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38085440

RESUMO

A water-soluble polysaccharide (EP) was purified from edible algae Enteromorpha prolifera. Gel permeation chromatography (GPC), ion chromatography (IC), and fourier transform infrared (FT-IR) were performed to characterize its structure. EP was defined as a low molecular weight (6625 Da) composed of rhamnose, glucose, glucuronic acid, xylose, galactose, arabinose, and mannose. Moreover, it was a sulfated polysaccharide with a degree of substitution (DS) of 1.48. Then, the high-fat diet/streptozotocin (HFD/STZ) induced diabetic mouse model was established to support evidence for a novel hypoglycemic mechanism. Results showed that blood glucose (47.32%), liver index (7.65%), epididymal fat index (16.86%), serum total cholesterol (26.78%) and triglyceride (37.61%) in the high-dose EP (HEP) group were significantly lower than those in the HFD group. Noticeably, the content of liver glycogen in the HEP group was significantly higher (62.62%) than that in the HFD group, indicating the promotion of glycogen synthesis. These beneficial effects were attributed to significantly increased protein kinase B (AKT) phosphorylation and its downstream signaling response. Further studies showed that diabetic mice exhibited excessive O-GlcNAcylation level and high expression of O-linked ß-D-N-acetylglucosamine transferase (OGT), which were decreased by 62.21 and 30.43% in the HEP group. This result suggested that EP had a similar effect to OGT inhibitors, which restored AKT phosphorylation and prevented pathoglycemia. This work reveals a novel hypoglycemic mechanism of EP, providing a theoretical basis for further studies on its pharmacological properties in improvement of T2DM.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Algas Comestíveis , Ulva , Animais , Camundongos , Diabetes Mellitus Tipo 2/prevenção & controle , Proteínas Proto-Oncogênicas c-akt , Sulfatos , Diabetes Mellitus Experimental/tratamento farmacológico , Espectroscopia de Infravermelho com Transformada de Fourier , Hipoglicemiantes/farmacologia , Polissacarídeos/farmacologia
5.
Biol Chem ; 404(6): 619-631, 2023 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-36780323

RESUMO

MicroRNA (miR)-143-3p is a potential regulatory molecule in myocardial ischemia/reperfusion injury (MI/RI), wherein its expression and pathological effects remains controversial. Thus, a mouse MI/RI and cell hypoxia/reoxygenation (H/R) models were built for clarifying the miR-143-3p's role in MI/RI. Following myocardial ischemia for 30 min, mice underwent reperfusion for 3, 6, 12 and 24 h. It was found miR-143-3p increased in the ischemic heart tissue over time after reperfusion. Cardiomyocytes transfected with miR-143-3p were more susceptible to apoptosis. Mechanistically, miR-143-3p targeted B cell lymphoma 2 (bcl-2). And miR-143-3p inhibition reduced cardiomyocytes apoptosis upon H/R, whereas it was reversed by a specific bcl-2 inhibitor ABT-737. Of note, miR-143-3p inhibition upregulated bcl-2 with better mitochondrial membrane potential (Δψm), reduced cytoplasmic cytochrome c (cyto-c) and caspase proteins, and minimized infarction area in mice upon I/R. Collectively, inhibition of miR-143-3p might alleviate MI/RI via targeting bcl-2 to limit mitochondria-mediated apoptosis. To our knowledge, this study further clarifies the miR-143-3p's pathological role in the early stages of MI/RI, and inhibiting miR-143-3p could be an effective treatment for ischemic myocardial disease.


Assuntos
MicroRNAs , Isquemia Miocárdica , Traumatismo por Reperfusão Miocárdica , Traumatismo por Reperfusão , Camundongos , Animais , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo , Traumatismo por Reperfusão Miocárdica/patologia , MicroRNAs/metabolismo , Isquemia Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Apoptose , Mitocôndrias/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Traumatismo por Reperfusão/metabolismo
6.
Crit Rev Biotechnol ; 43(8): 1129-1149, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36170978

RESUMO

The increased presence of xenobiotics affects living organisms and the environment at large on a global scale. Microbial degradation is effective for the removal of xenobiotics from the ecosystem. In natural habitats, biofilms are formed by single or multiple populations attached to biotic/abiotic surfaces and interfaces. The attachment of microbial cells to these surfaces is possible via the matrix of extracellular polymeric substances (EPSs). However, the molecular machinery underlying the development of biofilms differs depending on the microbial species. Biofilms act as biocatalysts and degrade xenobiotic compounds, thereby removing them from the environment. Quorum sensing (QS) helps with biofilm formation and is linked to the development of biofilms in natural contaminated sites. To date, scant information is available about the biofilm-mediated degradation of toxic chemicals from the environment. Therefore, we review novel insights into the impact of microbial biofilms in xenobiotic contamination remediation, the regulation of biofilms in contaminated sites, and the implications for large-scale xenobiotic compound treatment.


Assuntos
Ecossistema , Xenobióticos , Biofilmes , Percepção de Quorum/fisiologia
7.
Artigo em Inglês | MEDLINE | ID: mdl-37725099

RESUMO

A Gram-negative, yellow-pigmented, aerobic and rod-shaped bacterium, designated as strain BaP3T, was isolated from the soil. Strain BaP3T grew at 16-37℃ (optimum, 30 °C) and pH 6.0-8.0 (optimum, pH 7.0). Additionally, strain BaP3T could tolerate NaCl concentrations in the range 0-6 % (optimum, 1%). Moreover, strain BaP3T was motile by flagella. The phylogenetic analysis of 16S rRNA sequences showed that strain BaP3T belonged to the genus Pseudomonas, and the sequence was most closely related to Pseudomonas oryzihabitans CGMCC 1.3392T and Pseudomonas psychrotolerans DSM 15758T, with 99.66 % sequence similarity. Pseudomonas rhizoryzae RY24T was the next closely related species, exhibiting 99.38 % 16S rRNA gene sequence similarity. The DNA-DNA hybridization and average nucleotide identity values between strain BaP3T and its closely related types were below 50 and 92 %, respectively. Both results were below the cut-off for species distinction. The genomic DNA G+C content of strain BaP3T was 65.30 mol%. The predominant quinone in strain BaP3T was identified as ubiquinone Q-9. The major cellular fatty acids were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and C16 : 0. These results indicated that strain BaP3T represents a novel species in the genus Pseudomonas. The type strain is BaP3T (CCTCC AB 2022379T=JCM 35914T), for which the name Pseudomonas benzopyrenica sp. nov. is proposed.


Assuntos
Benzo(a)pireno , Solo , Composição de Bases , Ácidos Graxos/química , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , DNA Bacteriano/genética , Técnicas de Tipagem Bacteriana , Pseudomonas/genética
8.
Environ Res ; 236(Pt 1): 116699, 2023 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-37481057

RESUMO

For a long time, the well-known Gram-positive bacterium Bacillus thuringiensis (Bt) has been extensively studied and developed as a biological insecticide for Lepidoptera and Coleoptera pests due to its ability to secrete a large number of specific insecticidal proteins. In recent years, studies have found that Bt strains can also potentially biodegrade residual pollutants in the environment. Many researchers have isolated Bt strains from multiple sites polluted by exogenous compounds and characterized and identified their xenobiotic-degrading potential. Furthermore, its pathway for degradation was also investigated at molecular level, and a number of major genes/enzymes responsible for degradation have been explored. At present, a variety of xenobiotics involved in degradation in Bt have been reported, including inorganic pollutants (used in the field of heavy metal biosorption and recovery and precious metal recovery and regeneration), pesticides (chlorpyrifos, cypermethrin, 2,2-dichloropropionic acid, etc.), organic tin, petroleum and polycyclic aromatic hydrocarbons, reactive dyes (congo red, methyl orange, methyl blue, etc.), and ibuprofen, among others. In this paper, the biodegrading ability of Bt is reviewed according to the categories of related pollutants, so as to emphasize that Bt is a powerful agent for removing environmental pollutants.


Assuntos
Bacillus thuringiensis , Clorpirifos , Poluentes Ambientais , Inseticidas , Bacillus thuringiensis/genética , Poluentes Ambientais/metabolismo , Clorpirifos/metabolismo , Ibuprofeno , Proteínas de Bactérias , Endotoxinas
9.
Environ Res ; 235: 116570, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37423356

RESUMO

Sulfonylurea herbicides have been widely used worldwide and play a significant role in modern agricultural production. However, these herbicides have adverse biological effects that can damage the ecosystems and harm human health. As such, rapid and effective techniques that remove sulfonylurea residues from the environment are urgently required. Attempts have been made to remove sulfonylurea residues from environment using various techniques such as incineration, adsorption, photolysis, ozonation, and microbial degradation. Among them, biodegradation is regarded as a practical and environmentally responsible way to eliminate pesticide residues. Microbial strains such as Talaromyces flavus LZM1, Methylopila sp. SD-1, Ochrobactrum sp. ZWS16, Staphylococcus cohnii ZWS13, Enterobacter ludwigii sp. CE-1, Phlebia sp. 606, and Bacillus subtilis LXL-7 can almost completely degrade sulfonylureas. The degradation mechanism of the strains is such that sulfonylureas can be catalyzed by bridge hydrolysis to produce sulfonamides and heterocyclic compounds, which deactivate sulfonylureas. The molecular mechanisms associated with microbial degradation of sulfonylureas are relatively poorly studied, with hydrolase, oxidase, dehydrogenase and esterase currently known to play a pivotal role in the catabolic pathways of sulfonylureas. Till date, there are no reports specifically on the microbial degrading species and biochemical mechanisms of sulfonylureas. Hence, in this article, the degradation strains, metabolic pathways, and biochemical mechanisms of sulfonylurea biodegradation, along with its toxic effects on aquatic and terrestrial animals, are discussed in depth in order to provide new ideas for remediation of soil and sediments polluted by sulfonylurea herbicides.


Assuntos
Herbicidas , Humanos , Herbicidas/análise , Ecossistema , Compostos de Sulfonilureia/toxicidade , Compostos de Sulfonilureia/química , Compostos de Sulfonilureia/metabolismo , Sulfonamidas , Agricultura , Biodegradação Ambiental
10.
Environ Res ; 218: 114953, 2023 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-36504008

RESUMO

Neonicotinoids (NEOs) are fourth generation pesticides, which emerged after organophosphates, pyrethroids, and carbamates and they are widely used in vegetables, fruits, cotton, rice, and other industrial crops to control insect pests. NEOs are considered ideal substitutes for highly toxic pesticides. Multiple studies have reported NEOs have harmful impacts on non-target biological targets, such as bees, aquatic animals, birds, and mammals. Thus, the remediation of neonicotinoid-sullied environments has gradually become a concern. Microbial degradation is a key natural method for eliminating neonicotinoid insecticides, as biodegradation is an effective, practical, and environmentally friendly strategy for the removal of pesticide residues. To date, several neonicotinoid-degrading strains have been isolated from the environment, including Stenotrophomonas maltophilia, Bacillus thuringiensis, Ensifer meliloti, Pseudomonas stutzeri, Variovorax boronicumulans, and Fusarium sp., and their degradation properties have been investigated. Furthermore, the metabolism and degradation pathways of neonicotinoids have been broadly detailed. Imidacloprid can form 6-chloronicotinic acid via the oxidative cleavage of guanidine residues, and it is then finally converted to non-toxic carbon dioxide. Acetamiprid can also be demethylated to remove cyanoimine (=N-CN) to form a less toxic intermediate metabolite. A few studies have discussed the neonicotinoid toxicity and microbial degradation in contaminated environments. This review is focused on providing an in-depth understanding of neonicotinoid toxicity, microbial degradation, catabolic pathways, and information related to the remediation process of NEOs. Future research directions are also proposed to provide a scientific basis for the risk assessment and removal of these pesticides.


Assuntos
Inseticidas , Praguicidas , Abelhas , Animais , Inseticidas/toxicidade , Inseticidas/análise , Neonicotinoides/toxicidade , Neonicotinoides/análise , Insetos/metabolismo , Nitrocompostos/toxicidade , Nitrocompostos/metabolismo , Produtos Agrícolas/metabolismo , Biodegradação Ambiental , Mamíferos/metabolismo
11.
Postgrad Med J ; 99(1172): 605-612, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37319156

RESUMO

OBJECTIVE: To investigate the predictive value of age, creatinine and ejection fraction (ACEF) II score for the incidence of major adverse cardiovascular and cerebrovascular events (MACCEs) in patients with coronary heart disease (CHD) after percutaneous coronary intervention (PCI). METHODS: A total of 445 patients with CHD who underwent PCI were consecutively enrolled. The receiver operating characteristic (ROC) curve was used to analyse the power of the ACEF II score in predicting MACCE. Kaplan-Meier survival curves and log-rank tests were chosen for survival analysis of adverse prognosis between groups. Finally, multivariate Cox proportional risk regression analysis was used to investigate independent risk factors for MACCEs in patients with CHD after PCI. RESULTS: There was a significantly higher incidence of MACCEs in patients with high ACEF II scores. The area under the ROC curve of ACEF II score was 0.718, suggesting it had ideal predictive value for MACCE risks. The ACEF II score had a best cut-off value of 1.461 (sensitivity 79.4%, specificity 53.7%). Survival analysis indicated that patients in the high-score group had a significantly lower cumulative MACCE-free survival rate. Multivariate Cox regression analysis showed that ACEF II scores ≥1.461, Gensini scores ≥61.5, age, cardiac troponin I and previous PCI were independent risk factors of MACCE in patients with CHD after PCI, while the utilisation of statins was an independent protective factor. CONCLUSIONS: The ACEF II score has an ideal capacity for risk stratification in patients with CHD undergoing PCI and offers good predictive value for MACCE in the long term.


Assuntos
Doença da Artéria Coronariana , Doença das Coronárias , Intervenção Coronária Percutânea , Humanos , Intervenção Coronária Percutânea/efeitos adversos , Volume Sistólico , Fatores de Risco , Prognóstico , Doença da Artéria Coronariana/cirurgia , Medição de Risco , Resultado do Tratamento , Estudos Retrospectivos
12.
Biomed Chromatogr ; 37(6): e5627, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36932688

RESUMO

In order to achieve the long-term management of endometriosis, a more economical and environmentally friendly material, ethylene vinyl acetate (EVA), was used to prepare a intravaginal ring with anastrozole (ATZ). This paper has compared the pharmacokinetic parameters with oral tablets (Aida®) in mini pigs and evaluated the uterine targeted effect and mucosal irritation of the ring. A bioassay method was developed and validated for the determination of ATZ in mini pigs. The determination of ATZ was achieved by LC-MS/MS using terfenadine as the internal standard. Separation was achieved on a Kinetex-C18 110A chromatographic column (3 × 30 mm, 2.6 µm; Phenomenex) with a gradient mobile phase consisting of methanol (0.1% formic acid) and water (0.1% formic acid). The method has been proved to be scientific and sensitive through methodological validation and can be easily and quickly applied to the determination of the content of anastrozole in mini pigs. The pharmacokinetic test results show that there was no significant difference in pharmacokinetic parameters between the two formulations. The intravaginal ring has a passive targeting effect on the uterus, and its mucosal irritation is acceptable. The intravaginal ring provides a new method for long-term management of endometriosis.


Assuntos
Endometriose , Suínos , Feminino , Humanos , Animais , Anastrozol/farmacocinética , Cromatografia Líquida , Endometriose/tratamento farmacológico , Espectrometria de Massas em Tandem/métodos , Porco Miniatura , Reprodutibilidade dos Testes
13.
Ecotoxicol Environ Saf ; 255: 114810, 2023 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-36948015

RESUMO

Increasing evidence has shown that gut microbes play an important role in the reproductive endocrine system and the development of polycystic ovary syndrome (PCOS). However, whether environmental factors are involved in these gut microbiota alterations has seldom been studied. In this study, we aimed to explore the crucial role of an imbalanced gut microbiota on abnormal ovarian follicle development induced by Cu. A 1:1 matched case-control study with 181 PCOS patients and 181 controls was conducted using a propensity score matching protocol. Information regarding dietary Cu intake was obtained from a face-to-face dietary intake interview. Alterations in the gut microbiota were detected by high-throughput 16 S rDNA sequencing. The results showed that dietary Cu intake was positively correlated with the risk of PCOS, and the risk threshold was approximately 1.992 mg/d. Compared with those with dietary Cu intakes lower than 1.992 mg/d, those who had a higher dietary Cu intake had a 1.813-fold increased risk of PCOS (OR=1.813, 95% CI: 1.150-2.857). PCOS patients had a lower relative abundance of Bacteroides than controls (P = 0.003), and Bacteroides played a partial mediating role between dietary Cu exposure and PCOS (Pindirect effect=0.026, 95% CI: 0.002-0.072). In addition, an animal model of Cu exposure through the diet showed that Cu can induce gut microbiota disorder; increase serum levels of LPS, MDA, and IL-6; and alter host ovarian steroidogenesis to affect ovarian follicle development. Staphylococcus played a partial mediating role between Cu exposure and CYP17A1 (Pg_Staphylococcus=0.083, 95% CI: 0.001-0.228). Overall, this study shows that long-term exposure to high dietary Cu levels can affect the composition of the gut microbiota, cause inflammation and oxidative stress, and then interfere with hormone signaling, ultimately affecting ovarian follicle development.


Assuntos
Microbioma Gastrointestinal , Síndrome do Ovário Policístico , Feminino , Humanos , Animais , Cobre/toxicidade , Estudos de Casos e Controles , Folículo Ovariano
14.
Sensors (Basel) ; 23(13)2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-37447907

RESUMO

With the rapid development of Lidar technology, the use of Lidar for underwater terrain detection has become feasible. There is still a challenge in the process of signal resolution: the underwater laser echo signal is different to propagating in the air, and it is easy to produce weak waves and superimposed waves. However, existing waveform decomposition methods are not effective in processing these waveform signals, and the underwater waveform signal cannot be correctly decomposed, resulting in subsequent data-processing errors. To address these issues, this study used a drone equipped with a 532 nm laser to detect a pond as the study background. This paper proposes an improved inflection point selection decomposition method to estimate the parameter. By comparing it with other decomposition methods, we found that the RMSE is 2.544 and R2 is 0.995975, which is more stable and accurate. After estimating the parameters, this study used oscillating particle swarm optimization (OPSO) and the Levenberg-Marquardt algorithm (LM) to optimize the estimated parameters; the final results show that the method in this paper is closer to the original waveform. In order to verify the processing effect of the method on complex waveform, this paper decomposes and optimizes the simulated complex waveforms; the final RMSE is 0.0016, R2 is 1, and the Gaussian component after decomposition can fully represent the original waveform. This method is better than other decomposition methods in complex waveform decomposition, especially regarding weak waves and superimposed waves.


Assuntos
Algoritmos , Luz , Distribuição Normal
15.
Int J Mol Sci ; 24(20)2023 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-37895002

RESUMO

Polycyclic aromatic hydrocarbons (PAHs) are common carcinogens. Benzo(a)pyrene is one of the most difficult high-molecular-weight (HMW) PAHs to remove. Biodegradation has become an ideal method to eliminate PAH pollutants from the environment. The existing research is mostly limited to low-molecular-weight PAHs; there is little understanding of HMW PAHs, particularly benzo(a)pyrene. Research into the biodegradation of HMW PAHs contributes to the development of microbial metabolic mechanisms and also provides new systems for environmental treatments. Pseudomonas benzopyrenica BaP3 is a highly efficient benzo(a)pyrene-degrading strain that is isolated from soil samples, but its mechanism of degradation remains unknown. In this study, we aimed to clarify the high degradation efficiency mechanism of BaP3. The genes encoding Rhd1 and Rhd2 in strain BaP3 were characterized, and the results revealed that rhd1 was the critical factor for high degradation efficiency. Molecular docking and enzyme activity determinations confirmed this conclusion. A recombinant strain that could completely mineralize benzo(a)pyrene was also proposed for the first time. We explained the mechanism of the high-efficiency benzo(a)pyrene degradation ability of BaP3 to improve understanding of the degradation mechanism of highly toxic PAHs and to provide new solutions to practical applications via synthetic biology.


Assuntos
Hidrocarbonetos Policíclicos Aromáticos , Poluentes do Solo , Biodegradação Ambiental , Benzo(a)pireno/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Simulação de Acoplamento Molecular , Hidrocarbonetos Policíclicos Aromáticos/metabolismo , Poluentes do Solo/metabolismo
16.
Int J Mol Sci ; 24(2)2023 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-36674714

RESUMO

7-Hydroxytropolone (7-HT) is a unique iron scavenger synthesized by Pseudomonas donghuensis HYS that has various biological activities in addition to functioning as a siderophore. P. donghuensis HYS is more pathogenic than P. aeruginosa toward Caenorhabditis elegans, an observation that is closely linked to the biosynthesis of 7-HT. The nonfluorescent siderophore (nfs) gene cluster is responsible for the orderly biosynthesis of 7-HT and represents a competitive advantage that contributes to the increased survival of P. donghuensis HYS; however, the regulatory mechanisms of 7-HT biosynthesis remain unclear. This study is the first to propose that the ECF σ factor has a regulatory effect on 7-HT biosynthesis. In total, 20 ECF σ factors were identified through genome-wide scanning, and their responses to extracellular ferrous ions were characterized. We found that SigW was both significantly upregulated under high-iron conditions and repressed by an adjacent anti-σ factor. RNA-Seq results suggest that the SigW/RsiW system is involved in iron metabolism and 7-HT biosynthesis. Combined with the siderophore phenotype, we also found that SigW could inhibit siderophore synthesis, and this inhibition can be relieved by RsiW. EMSA assays proved that SigW, when highly expressed, can directly bind to the promoter region of five operons of the nfs cluster to inhibit the transcription of the corresponding genes and consequently suppress 7-HT biosynthesis. In addition, SigW not only directly negatively regulates structural genes related to 7-HT synthesis but also inhibits the transcription of regulatory proteins, including of the Gac/Rsm cascade system. Taken together, our results highlight that the biosynthesis of 7-HT is negatively regulated by SigW and that the SigW/RsiW system is involved in mechanisms for the regulation of iron homeostasis in P. donghuensis HYS. As a result of this work, we identified a novel mechanism for the global negative regulation of 7-HT biosynthesis, complementing our understanding of the function of ECF σ factors in Pseudomonas.


Assuntos
Ferro , Sideróforos , Ferro/metabolismo , Sideróforos/metabolismo , Proteínas de Bactérias/metabolismo , Fator sigma/genética , Fator sigma/metabolismo , Pseudomonas/genética , Pseudomonas/metabolismo , Regulação Bacteriana da Expressão Gênica
17.
Postgrad Med J ; 98(1161): e8, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33541926

RESUMO

PURPOSE: Lifestyle plays an important role in the development of ischaemic stroke (IS). The objective of this study was to evaluate the association between combined lifestyle factors and the risk of IS in an eastern Chinese population. METHODS: We collected lifestyle information from 191 patients with IS admitted to the second affiliated hospital of Soochow University and 575 control subjects from community clinics using a structured questionnaire. After division into training and test datasets, regularised stepwise logistic regression, least absolute shrinkage and selection operator regression and genetic algorithm models were used to identify lifestyle factors associated with IS. The improved discriminative ability by adding the lifestyle factors was determined by c-index and reclassification analysis. The final model was validated in the test dataset. RESULTS: After controlling for conventional cardiovascular disease (CVD) risk factors, preferences for fruits (OR (95% CI): 0.29 (0.18-0.46), p<0.001) and soy products (0.47 (0.29-0.75), p=0.002) were negatively associated with IS, while lower life satisfaction (mildly satisfied: 2.15 (1.27-3.63), p=0.004; not satisfied: 6.39 (1.76-25.44), p=0.006) was positively associated with IS. Adding these factors to a basic CVD risk model improved the c-index (0.825 vs 0.753, p<0.001) and reclassification for IS (net reclassification index (95% CI): 18.49% (7.90%-29.08%), integrated discrimination index (95% CI): 0.11% (0.08%-0.14%), p<0.001). The model with lifestyle factors achieved a c-index of 0.813 and good calibration in the test dataset. CONCLUSIONS: Our results showed that combined lifestyle factors including dietary pattern and life satisfaction are independently associated with the risk of IS.


Assuntos
Isquemia Encefálica , Doenças Cardiovasculares , AVC Isquêmico , Acidente Vascular Cerebral , Isquemia Encefálica/epidemiologia , Isquemia Encefálica/etiologia , China/epidemiologia , Humanos , Estilo de Vida , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/etiologia
18.
Biochem Biophys Res Commun ; 544: 60-64, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33516883

RESUMO

As fluorescence in the second near-infrared window (NIR-II, 1000-1400 nm) could image deep tissue with high signal-to-noise ratios compared with that in NIR-I (750-900 nm), Ag2Se quantum dots (QDs) with fluorescence in the NIR-II could be ideal fluorophores. Here, we described a biosynthesis method to prepare the Ag2Se QDs by using temporally coupling the irrelated biochemical reactions, whose photoluminescence (PL) emission can reach NIR-II. The nanoparticles were characterized by transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (XRD). The results showed that the nanoparticles obtained by extracellular purification were Ag2Se QDs with a uniform size of 3.9 ± 0.6 nm. In addition, the fluorescence intensity of Saccharomyces cerevisiae was improved successfully by nearly 4-fold by constructed engineering strain. In particular, the biosynthesis of Ag2Se QDs had good biocompatibility because it was capped by protein. Furthermore, investigating the toxicity of Ag2Se on cells and NIR images of nude mice showed that the Ag2Se synthesized using S. cerevisiae had low toxicity and could be used for in vivo imaging. In this work, the synthesis pathway of biocompatible Ag2Se was broadened and laid a foundation for the enlarged applicability of bioimaging in the biosynthesis of NIR-II QDs.


Assuntos
Raios Infravermelhos , Teste de Materiais/métodos , Pontos Quânticos/química , Saccharomyces cerevisiae/metabolismo , Selênio/química , Prata/química , Animais , Células Cultivadas , Fluorescência , Masculino , Camundongos , Camundongos Nus , Microscopia Eletrônica de Transmissão/métodos , Pontos Quânticos/toxicidade , Selênio/toxicidade , Prata/toxicidade
19.
Bioorg Chem ; 114: 105115, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34175725

RESUMO

Transient receptor potential vanilloid 3 (TRPV3) channel as a member of thermo TRPV subfamily is primarily expressed in the keratinocytes of the skin and sensory neurons, and plays critical roles in various physiological and pathological processes such as inflammation, pain sensation and skin disorders. However, TRPV3 studies have been challenging, in part due to a lack of research tools such as selective antagonists. Recently, we synthesized a series of cinnamate ester derivatives and evaluated their inhibitory activities on human TRPV3 channels expressed in HEK293 cells using whole-cell patch clamp recordings. And, we identified two potent TRPV3 antagonists 7c and 8c which IC50 values were 1.05 µM and 86 nM, respectively. It also showed good selectivity to other subfamily members of TRPV, such as TRPV1 and TRPV4.


Assuntos
Cinamatos/farmacologia , Desenho de Fármacos , Ésteres/farmacologia , Canais de Cátion TRPV/antagonistas & inibidores , Cinamatos/síntese química , Cinamatos/química , Relação Dose-Resposta a Droga , Ésteres/síntese química , Ésteres/química , Células HEK293 , Humanos , Estrutura Molecular , Relação Estrutura-Atividade
20.
Mol Ther ; 28(10): 2111-2119, 2020 10 07.
Artigo em Inglês | MEDLINE | ID: mdl-32910911

RESUMO

Cardiovascular diseases (CVDs) remain the leading cause of death and disability worldwide, despite marked improvements in prevention, diagnosis, and early intervention. There is an urgent need to discover more effective therapeutic strategies, which would be facilitated by a more in-depth understanding of CVDs and their underlying molecular mechanisms. Recent advances in knowledge about epigenetic mechanisms, especially RNA methylation, have revealed a close relationship between epigenetic modifications and CVDs and have brought to potential novel targets for diagnosis and treatment. Here, we provide a review of recent studies exploring RNA N6-methyladenosine (m6A) modification, with particular emphasis on its role in CVDs, such as coronary heart disease, hypertension, cardiac hypertrophy, and heart failure. We also introduce the "life cycle" of m6A and its dominant function in several biological processes. Finally, we highlight the prospects of treatment based on interfering with m6A, which could have a transformative effect on clinical medicine.


Assuntos
Adenosina/análogos & derivados , Doenças Cardiovasculares/etiologia , RNA/metabolismo , Adenosina/metabolismo , Doenças Cardiovasculares/diagnóstico , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/metabolismo , Suscetibilidade a Doenças , Epigênese Genética , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Metilação , Terapia de Alvo Molecular , RNA/genética
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA