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1.
Plant Cell Environ ; 47(11): 4383-4397, 2024 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38988259

RESUMO

Loss of Lon1 led to stunted plant growth and accumulation of nuclear-encoded mitochondrial proteins including Lon1 substrates. However, an in-depth label-free proteomics quantification of mitochondrial proteins in lon1 revealed that the majority of mitochondrial-encoded proteins decreased in abundance. Additionally, we found that lon1 mutants contained protein aggregates in the mitochondrial that were enriched in metabolic enzymes, ribosomal subunits and PPR-containing proteins of the translation apparatus. These mutants exhibited reduced general mitochondrial translation as well as deficiencies in RNA splicing and editing. These findings support the role of Lon1 in maintaining a functional translational apparatus for mitochondrial-encoded gene translation. Transcriptome analysis of lon1 revealed a mitochondrial unfolded protein response reminiscent of the mitochondrial retrograde signalling dependent on the transcription factor ANAC017. Notably, lon1 mutants exhibited transiently elevated ethylene production, and the shortened hypocotyl observed in lon1 mutants during skotomorphogenesis was partially alleviated by ethylene inhibitors. Furthermore, the short root phenotype was partially ameliorated by introducing a mutation in the ethylene receptor ETR1. Interestingly, the upregulation of only a select few target genes was linked to ETR1-mediated ethylene signalling. Together this provides multiple steps in the link between loss of Lon1 and signalling responses to restore mitochondrial protein homoeostasis in plants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Mitocôndrias , Proteínas Mitocondriais , Resposta a Proteínas não Dobradas , Arabidopsis/genética , Arabidopsis/metabolismo , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Biossíntese de Proteínas , Regulação da Expressão Gênica de Plantas , Agregados Proteicos , Mutação , Transdução de Sinais , Etilenos/metabolismo , Proteômica , Proteases Dependentes de ATP/metabolismo , Proteases Dependentes de ATP/genética , Serina Endopeptidases , Fatores de Transcrição
2.
Sensors (Basel) ; 24(1)2024 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-38203136

RESUMO

Most single-object trackers currently employ either a convolutional neural network (CNN) or a vision transformer as the backbone for object tracking. In CNNs, convolutional operations excel at extracting local features but struggle to capture global representations. On the other hand, vision transformers utilize cascaded self-attention modules to capture long-range feature dependencies but may overlook local feature details. To address these limitations, we propose a target-tracking algorithm called CVTrack, which leverages a parallel dual-branch backbone network combining CNN and Transformer for feature extraction and fusion. Firstly, CVTrack utilizes a parallel dual-branch feature extraction network with CNN and transformer branches to extract local and global features from the input image. Through bidirectional information interaction channels, the local features from the CNN branch and the global features from the transformer branch are able to interact and fuse information effectively. Secondly, deep cross-correlation operations and transformer-based methods are employed to fuse the template and search region features, enabling comprehensive interaction between them. Subsequently, the fused features are fed into the prediction module to accomplish the object-tracking task. Our tracker achieves state-of-the-art performance on five benchmark datasets while maintaining real-time execution speed. Finally, we conduct ablation studies to demonstrate the efficacy of each module in the parallel dual-branch feature extraction backbone network.

3.
Int J Mol Sci ; 25(10)2024 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-38791463

RESUMO

Mitochondrial protein homeostasis is crucially regulated by protein degradation processes involving both mitochondrial proteases and cytosolic autophagy. However, it remains unclear how plant cells regulate autophagy in the scenario of lacking a major mitochondrial Lon1 protease. In this study, we observed a notable downregulation of core autophagy proteins in Arabidopsis Lon1 knockout mutant lon1-1 and lon1-2, supporting the alterations in the relative proportions of mitochondrial and vacuolar proteins over total proteins in the plant cells. To delve deeper into understanding the roles of the mitochondrial protease Lon1 and autophagy in maintaining mitochondrial protein homeostasis and plant development, we generated the lon1-2atg5-1 double mutant by incorporating the loss-of-function mutation of the autophagy core protein ATG5, known as atg5-1. The double mutant exhibited a blend of phenotypes, characterized by short plants and early senescence, mirroring those observed in the individual single mutants. Accordingly, distinct transcriptome alterations were evident in each of the single mutants, while the double mutant displayed a unique amalgamation of transcriptional responses. Heightened severity, particularly evident in reduced seed numbers and abnormal embryo development, was observed in the double mutant. Notably, aberrations in protein storage vacuoles (PSVs) and oil bodies were evident in the single and double mutants. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses of genes concurrently downregulated in lon1-2, atg5-1, and lon1-2atg5-1 unveiled a significant suppression of genes associated with brassinosteroid (BR) biosynthesis and homeostasis. This downregulation likely contributes to the observed abnormalities in seed and embryo development in the mutants.


Assuntos
Proteínas de Arabidopsis , Arabidopsis , Autofagia , Brassinosteroides , Regulação da Expressão Gênica de Plantas , Mitocôndrias , Sementes , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/crescimento & desenvolvimento , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Autofagia/genética , Sementes/crescimento & desenvolvimento , Sementes/genética , Sementes/metabolismo , Mitocôndrias/metabolismo , Brassinosteroides/metabolismo , Proteases Dependentes de ATP/metabolismo , Proteases Dependentes de ATP/genética , Mutação , Proteínas Mitocondriais/metabolismo , Proteínas Mitocondriais/genética , Regulação para Baixo , Fenótipo , Serina Endopeptidases
4.
Neurochem Res ; 47(8): 2198-2210, 2022 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-35513760

RESUMO

The antiknock additive methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic manganese(Mn) compound. Mn neurotoxicity caused by occupational Mn exposure (mostly inorganic MnCl2) is associated with motor and cognitive disturbances, referred to as Manganism. However, the impact of environmentally relevant Mn exposure on MMT-induced Manganism is poorly understood. In this investigation, we studied the effects of MMT on motor function and brain structure, and compared its effects with those of inorganic MnCl2. After adaptive feeding for 7 days, male and female Sprague-Dawley (SD) rats in the MMT-treated groups and positive control group were treated for 8 weeks with MMT (1, 2 and 4 mg/kg/i.g.) or MnCl2·4H2O (200 mg/kg/i.g.). Mn content in blood, liver, spleen and distinct brain regions was determined by inductively coupled plasma-mass spectrometer (ICP-MS). We found that MMT and MnCl2 exposure led to slower body-weight-gain in female rats, impaired motor and balance function and spatial learning and memory both in male and female rats. HE staining showed that MMT and MnCl2 led to altered structure of the substantia nigra pars compacta (SNpc), and Nissl staining corroborated MMT's propensity to damage the SNpc both in male and female rat. In addition, Immunostaining of the SNpc showed decreased TH-positive neurons in MMT- and MnCl2-treated rats, concomitant with Iba1 activation in microglia. Moreover, no statistically significant difference was noted between the rats in the H-MMT and MnCl2 groups. In summary, these findings suggest that MMT and MnCl2 exposure cause ultrastructural changes in the SNpc neurons culminating in altered motor behavior and cognition, suggesting that altered SNpc structure and function may underline the motor and cognitive deficits inherent to Manganism, and accounting for MMT and MnCl2's manifestations of atypical parkinsonism.


Assuntos
Intoxicação por Manganês , Manganês , Animais , Cloretos , Feminino , Masculino , Manganês/toxicidade , Compostos de Manganês , Ratos , Ratos Sprague-Dawley , Substância Negra
5.
Phys Chem Chem Phys ; 24(3): 1760-1769, 2022 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-34985063

RESUMO

Sulfonated N-heterocyclic poly(aryl ether) proton-exchange membranes have potential applications in the fuel-cell field due to their favorable proton conduction capacity and stability. This paper investigates the changes in mass and performance decay, such as proton conduction and mechanical strength, of sulfonated poly(ether ether ketone)s (SPEEKs) and three sulfonated N-heterocyclic poly(aryl ether ketone) (SPPEK, SPBPEK-P-8, and SPPEKK-P) membranes in Fenton's oxidative experiment. The SPEEK membrane exhibited the worst oxidative stability. The oxidative stability of the SPPEK membrane is enhanced due to the introduction of phthalazinone units in the chains. The SPPEKK-P and SPBPEK-P-8 membranes exhibit better radical tolerance than the SPPEK membrane, with proton conductivity retention rates of 66% and 73% for 1 h oxidative treatment, respectively. In addition, the molecular chains of SPPEKK-P and SPBPEK-P-8 exhibit relatively little disruption. The pendant benzenesulfonic groups enhance the steric effects for reducing radical attacks on the ether bonds and reduce the hydration of molecular chains. The introduction of phthalazinone units decreases the rupture points in the main chain. Therefore, the radical tolerance of the membranes is improved. These results provide a reference for the design of highly stable sulfonated heterocyclic poly(aryl ether) membranes.

6.
Chem Biodivers ; 19(7): e202200383, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35739622

RESUMO

We used UV-guided method to isolate and identify 12 secondary metabolites from Meehania fargesii var. Radicans for the first time, including eight triterpenoids (1-8), two phenylpropanoid derivatives (9-10) and two flavone glycosides (11-12). Their structures were identified by NMR spectroscopic methods, as well as literature comparison. The identified compounds and positive drugs (amoxicillin, omeprazole and clarithromycin) were further analyzed for their in silico docking interactions with HtrA using igemdock. Docking studies revealed the high binding affinity of phytochemicals at significant sites with HtrA, compounds 11 and 12 exhibiting stronger binding ability than standard drug, 1 and 3-10 demonstrating comparable docking capacity to standard drugs. The chemotaxonomic relationships were carried out to exploring the possibilities of other medicinal plants against Hp-induced gastric carcinoma. The results demonstrated there are closely chemotaxonomic similarity among several genera of the Lamiaceae family as well as among Lamiaceae, Actinidiaceae and Rosaceae families, indicating a similar chemical compositions and anti-Hp-induces gastric carcinoma activity among them.


Assuntos
Carcinoma , Infecções por Helicobacter , Helicobacter pylori , Lamiaceae , Antibacterianos/farmacologia , Carcinoma/tratamento farmacológico , Infecções por Helicobacter/tratamento farmacológico , Humanos , Simulação de Acoplamento Molecular , Compostos Fitoquímicos/farmacologia
7.
Phys Chem Chem Phys ; 22(41): 23474-23481, 2020 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-33111732

RESUMO

Rational and purposeful designs of amorphous materials with desirable structures are difficult to implement due to the complex and unordered nature of such materials. In this work, a modelling algorithm was proposed for amorphous covalent triazine-based polymers to construct atomistic representative models that can reproduce the experimentally measured properties of experimental samples. The constructed models were examined through comparisons of simulated and experimental properties, such as surface area, pore volume, and structure factor, and further validated by the good consistency observed among these properties. To assess the predictive capability of the modelling algorithm, we used a new covalent triazine-based polymer and predicted its porosity by constructing a simulated model. The predicted results on the surface area and pore volume of the simulated model were quantitatively consistent with the experimental data derived from the experimentally synthesized sample. This consistency reveals the predictive capacity of the proposed modelling algorithm. The algorithm could be a promising approach to predict and develop advanced covalent triazine-based polymers for multiple applications.

8.
J Environ Manage ; 262: 110339, 2020 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-32250816

RESUMO

Water temperature is an important factor that affects the number and variety of river species. After a reservoir is built, a river's thermal regime changes significantly. Analyzing and evaluating river water temperature variation trends caused by damming can provide scientific support for developing effective water management strategies for reservoirs. This paper aimed to construct an index system of water temperatures in high and cold areas of the Upper Yellow River, and a method was proposed for identifying river water temperature variation based on principal component analysis (PCA). The variation degree in the river water temperature caused by large reservoirs was analyzed quantitatively. A three-dimensional water temperature model was developed to simulate the effect of a stratified intake on the alleviation of low-temperature water. The results indicated that (1) the water temperature decreased in summer and increased in winter, seasonal temperature changes decreased, there was a time delay in water temperature processes and a time fluctuation in the temperature threshold. (2) Certain indices were obtained that considered fish spawning and breeding, thermal condition changes and interactions between the organisms influenced by the reservoirs. (3) A stratified intake has a good effect on mitigating the impact of low water temperatures on fish spawning to some extent. The index system of the water temperature and its gradient changes effectively analyzed the influence of the reservoirs on river water temperature variations.


Assuntos
Rios , Água , Animais , China , Monitoramento Ambiental , Análise de Componente Principal , Estações do Ano , Temperatura
9.
J Comput Chem ; 39(15): 889-900, 2018 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-29330902

RESUMO

The conformational structures and properties of the anticancer drug docetaxel (DTX) are studied theoretically. A total of 3888 trial structures were initially generated by all combinations of internal single-bond rotamers and screened with the B3LYP/3-21G* method. A total of 31 unique conformers were further optimized at the B3LYP/6-311G* method. Their relative energies, dipole moments, rotational constants, and harmonic vibrational frequencies were predicted. Single-point relative energies were then determined at the M06-L/6-311G(2df,p) level. The UV spectrum of the lowest-lying DTX conformer in methanol was investigated with the TD-CAM-B3LYP/6-311 + G(2df,p) method. The 31 unique DTX structures are mainly docked at three different sites within ß-tubulin. Based on the results of molecular docking and double-float MD simulations, the lowest-lying DTX conformer consistently exhibits good docking performance with ß-tubulin. We identified the residues LYS299, ARG215, GLN294, LEU275, THR216, GLU290, PRO274, and THR276 on ß-tubulin as active sites forming a binding pocket responsible for locking DTX within ß-tubulin to make the combination more stable. The RMSD values show that the predicted complexes are favorable, and the SASA analysis shows that the hydrophilic properties of DTX are better than paclitaxel. © 2018 Wiley Periodicals, Inc.


Assuntos
Antineoplásicos/química , Teoria da Densidade Funcional , Docetaxel/química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Conformação Molecular
10.
Chemphyschem ; 19(13): 1579-1583, 2018 07 05.
Artigo em Inglês | MEDLINE | ID: mdl-29603849

RESUMO

Graphene oxide has become an attractive electrode-material candidate for supercapacitors thanks to its higher specific capacitance compared to graphene. The quantum capacitance makes relative contributions to the specific capacitance, which is considered as the major limitation of graphene electrodes, while the quantum capacitance of graphene oxide is rarely concerned. This study explores the quantum capacitance of graphene oxide, which bears epoxy and hydroxyl groups on its basal plane, by employing density functional theory (DFT) calculations. The results demonstrate that the total density of states near the Fermi level is significantly enhanced by introducing oxygen-containing groups, which is beneficial for the improvement of the quantum capacitance. Moreover, the quantum capacitances of the graphene oxide with different concentrations of these two oxygen-containing groups are compared, revealing that more epoxy and hydroxyl groups result in a higher quantum capacitance. Notably, the hydroxyl concentration has a considerable effect on the capacitive behavior.

11.
J Chem Phys ; 149(7): 074312, 2018 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-30134706

RESUMO

The vibrationally resolved fluorescence spectrum of a narrow-line single-molecule transducer, fused 5,15-(diphenyl)-10,20-(dibromo)porphyrin (fused-H2P) molecule, has been calculated by time-dependent density functional theory with the inclusion of both Franck-Condon and Herzberg-Teller contributions. Analytical transition dipole derivatives are used for the calculations of Herzberg-Teller terms to eliminate the possible errors caused by numerical differentials. The performance of different exchange-correlation functionals including B3LYP, ωB97X-D, and M06-2X has been examined. The comparison with the high-resolution experimental emission spectrum indicates that all three functionals can satisfactorily describe the fluorescence spectral profile, while ωB97X-D and M06-2X give slightly better excitation energy than B3LYP. Detailed analysis shows that the fluorescence spectrum is dominated by the Franck-Condon contribution, while the Herzberg-Teller term contributes mostly to its low energy tail. It is found that the size of the basis set has limited influence on the fluorescence spectrum, and a standard 6-31G(d, p) basis set is adequate for the purpose. The substitution of terthiophene side chains is found to have minor effects on the fluorescence spectrum. Our study provides unambitious assignments for all the vibronic structures in the experimental spectrum.

12.
Biochem Biophys Res Commun ; 473(4): 1100-1105, 2016 05 13.
Artigo em Inglês | MEDLINE | ID: mdl-27074580

RESUMO

Onion (Allium cepa L.) is one of the important vegetable crops in the world, usually with a two-year life cycle. The bulbs form in the first year after sowing, then bolting and flowering are induced by low temperature in the following year. Previous studies have shown that LEAFY gene is an inflorescence tissue specific gene, and that it is also the ultimate collection channel of all flowering pathway. In this study, using homologous gene cloning and reverse transcription-PCR (RT-PCR), we isolated an inflorescence meristem specific LEAFY cDNA, AcLFY (JX275962), from onion. AcLFY contains a 1119 bp open reading frame, which encodes a putative protein of 372 amino acids, with ∼70% homology to the daffodils LEAFY and >50% homology to LEAFY proteins from other higher plants. Fluorescence quantitative results showed that AcLFY gene has the highest expression level in inflorescence meristem during early bolting, and is still expressed in leaves after the formation of flower organs. Overexpression of AcLFY gene in Arabidopsis thaliana induced early bolting and flowering, whereas knockdown of the endogenous LEAFY gene by RNAi caused a significant delay in bolting. In addition, transgenic plants also exhibited significant morphological changes in rosette leaves, branches, and plant height.


Assuntos
Proteínas de Arabidopsis/química , Proteínas de Arabidopsis/fisiologia , Arabidopsis/fisiologia , Flores/crescimento & desenvolvimento , Cebolas/fisiologia , Sementes/crescimento & desenvolvimento , Fatores de Transcrição/química , Fatores de Transcrição/fisiologia , Clonagem Molecular/métodos , Plantas Geneticamente Modificadas/fisiologia
13.
J Comput Chem ; 37(13): 1214-22, 2016 05 15.
Artigo em Inglês | MEDLINE | ID: mdl-26833761

RESUMO

The genetic algorithm (GA) is an intelligent approach for finding minima in a highly dimensional parametric space. However, the success of GA searches for low energy conformations of biomolecules is rather limited so far. Herein an improved GA scheme is proposed for the conformational search of oligopeptides. A systematic analysis of the backbone dihedral angles of conformations of amino acids (AAs) and dipeptides is performed. The structural information is used to design a new encoding scheme to improve the efficiency of GA search. Local geometry optimizations based on the energy calculations by the density functional theory are employed to safeguard the quality and reliability of the GA structures. The GA scheme is applied to the conformational searches of Lys, Arg, Met-Gly, Lys-Gly, and Phe-Gly-Gly representative of AAs, dipeptides, and tripeptides with complicated side chains. Comparison with the best literature results shows that the new GA method is both highly efficient and reliable by providing the most complete set of the low energy conformations. Moreover, the computational cost of the GA method increases only moderately with the complexity of the molecule. The GA scheme is valuable for the study of the conformations and properties of oligopeptides. © 2016 Wiley Periodicals, Inc.


Assuntos
Algoritmos , Aminoácidos/química , Dipeptídeos/química , Modelos Genéticos , Oligopeptídeos/química , Conformação Proteica
14.
Zhongguo Zhong Xi Yi Jie He Za Zhi ; 35(12): 1501-4, 2015 Dec.
Artigo em Zh | MEDLINE | ID: mdl-26882615

RESUMO

OBJECTIVE: To study pharmacokinetic effect of Aikeqing Granule (AG) by different medication ways on zidovudine (AZT) in highly active antiretroviral therapy ( HAART) of rats. METHODS: Totally 36 rats were administered with corresponding medications by gastrogavage, group I [HAART: AZT 31.5 mg/kg +3TC 31.5 mg/kg + Efavirenz (EFV) 63.0 mg/kg], group II (HAART+AG525 mg/kg), group III (HAART and AG 525 mg/kg after a 2-h interval). Drug concentrations of AZT were determined by high performance liquid chromatography-mass spectroscopy (HPLC-MS) before HAART, and at 0.5, 1, 2, 3, 4, 6, 8, 10, 12 h after HAART, respectively. Pharmacokinetic parameters [such as t1/2, Tmax, Cmax, AUCo-t, plasma clearance rate (CL)] were calculated by DAS2.0 Software. RESULTS: The-equation of linear regression of AZT was good, with the precision, coefficient of recovery, and stability definitely confirmed. AUC in group II and III was larger than that of group I. There was no statistical difference in t1/2, Tmax, Cmax, AUC0-12 h, or AUC0-∞ among groups (P > 0.05). CONCLUSION: AG combined HAART could enhance the Cmax of AZT.


Assuntos
Medicamentos de Ervas Chinesas/farmacocinética , Zidovudina/farmacocinética , Alcinos , Animais , Terapia Antirretroviral de Alta Atividade , Benzoxazinas , Cromatografia Líquida de Alta Pressão , Ciclopropanos , Medicamentos de Ervas Chinesas/farmacologia , Espectrometria de Massas , Ratos , Zidovudina/farmacologia
15.
Heliyon ; 10(3): e24500, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38317906

RESUMO

In recent years, the centrifugal casting material Cr35Ni45Nb has been widely used in cracking furnace tubes. The common failure forms in the service process are carburizing cracking, bending, bulging, creep cracking, thermal fatigue cracking, thermal shock cracking, and oxidation, among which the inner wall oxidation and carburization of cracking furnace tubes cause the largest proportion of material failure. In this paper, we will discuss the inner wall oxidation behavior of cracking furnace tubes and its influence on the lasting strength of the furnace tubes. Several groups of endurance tests were designed for service furnace tubes, and the oxidation characteristics, oxide film rupture damage, and its influence on the endurance life of furnace tubes in different service times were analyzed by means of XRD, SEM, and so on. The results show that the oxide layer of the furnace tube is divided into two layers, the outer layer is repeatedly destroyed and rebuilt. With the continuous evolution of material structure, its properties also deteriorate, and its tensile strength, yield strength, elongation, and durable life all decrease significantly.

16.
Molecules ; 18(7): 7873-85, 2013 Jul 04.
Artigo em Inglês | MEDLINE | ID: mdl-23884124

RESUMO

The potential energy surfaces (PES) for the reaction of 1-bromo-3,3,3-trifluoropropene (CF3CHCBrH) with hydroxyl (OH) free radicals is probed theoretically at the CCSD/aug-cc-pVDZ//B3LYP/6-311++G(d,p) level of theory. All the possible stationary and first-order saddle points along the reaction paths were verified by the vibrational analysis. The calculations account for all the product channels. Based on the calculated CCSD/aug-cc-pVDZ potential energy surface, the possible reaction mechanism is discussed. Six distinct reaction pathways of 1-bromo-3,3,3-trifluoropropene (BTP) with OH are investigated. The geometries, reaction enthalpies and energy barriers are determined. Canonical transition-state theory with Wigner tunneling correction was used to predict the rate constants for the temperature range of 290-3,000 K without any artificial adjustment, and the computed rate constants for elementary channels can be accurately fitted with three-parameter Arrhenius expressions. OH addition reaction channel and the H atom abstraction channels related to the carbon-carbon double bond are found to be the main reaction channels for the reaction of 1-bromo-3,3,3-trifluoropropene (CF3CHCBrH) with hydroxyl (OH) free radicals while the products leading to CF3CHCH + BrOH and COHF2CHCBrH + F play a negligible role.


Assuntos
Clorofluorcarbonetos/química , Radical Hidroxila/química , Teoria Quântica , Termodinâmica , Carbono/química , Radicais Livres/química , Hidrogênio/química , Modelos Químicos , Modelos Teóricos , Temperatura
17.
Sci Rep ; 13(1): 18592, 2023 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-37903981

RESUMO

Cracking furnaces, operating under high temperatures and in a hydrocarbon medium, subject their tubes to complex stresses such as internal pressure, self-weight, fatigue, and thermal shock during start-up and shutdown. As a result, these furnace tubes frequently experience failures characterized by cracks and corrosion perforation. The high-temperature environment, constantly evolving structure of the tubes, and the close arrangement of the cracks within the tube box hinder detecting the cracks using conventional single-detection methods is challenging. This paper breaks through the limitations of the traditional single detection method and studies the effectiveness of the combination of ultrasonic-guided wave and low-frequency electromagnetic detection methods. The experiment was carried out by deliberately making cracks and thinning defects caused by corrosion on the cracking furnace tube of Cr35Ni45Nb after two years of service. The experimental results show that the ultrasonic guided wave detection technology can quickly detect the defects running through the whole furnace tube and effectively identify the manufacturing defects. On the other hand, low-frequency electromagnetic detection makes it possible to scan suspicious local defects and make qualitative and quantitative analyses of defect signals. The combination of ultrasonic guided wave and low-frequency electromagnetic detection can realize the rapid location and comprehensive qualitative and quantitative analysis of furnace tube defects, thus making up for the defects missed detection caused by the lack of effectiveness of single detection and the resulting safety problems. The research results have great popularization value in practical engineering applications.

18.
Nat Prod Res ; 37(2): 348-353, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34396839

RESUMO

The phytochemical investigation on the leaves of Psidium guajava Linn. led to the isolation and identification of 18 compounds, including six guavinoside (1-6), four flavonoids (7-10), eight triterpenoids (11-17) and one lignans (18). All chemical structures were elucidated via NMR spectroscopic methods, and further supported by comparison with literature data. Compounds 12, 14, 16 and 18 was isolated from the Myrtaceae family for the first time. The chemotaxonomic significance of these compounds was also discussed based on their structure types, as well as compounds-genus/family network analysis. The results showed that there were close chemotaxonomic relationships among the Myrtaceae, Asteraceae, and Lamiaceae families. Guavinosides A-F could be considered as valuable chemotaxonomic markers of Myrtaceae family, while guavinosides C-F might serve as chemotaxonomic markers for distinguishing the P. guajava.


Assuntos
Myrtaceae , Psidium , Humanos , Psidium/química , Folhas de Planta/química , Extratos Vegetais/química , Flavonoides/química
19.
Heliyon ; 9(11): e22254, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-38058623

RESUMO

In the domestic petrochemical industry, mounded storage tanks (MSTs) are widely used to store hazardous chemicals. The shell of the mounded storage tank is completely covered by soil to effectively mitigate the effect of the external environment and prevent thermal-expansion-induced explosion of the stored material. Because mounded storage tanks are mostly underground, they are highly safe, provide effective land utilization, and are highly energy efficient. Furthermore, the impact radius in case of an explosion is less than that of aboveground tanks. However, adequate regulations and standards for safety management are yet to be established. This study established a novel method for the integrity management of mounded storage tanks through database construction, risk assessment, applicability monitoring, and testing. At the same time, the risk assessment method for mounded storage tank characteristics is constructed for the first time.

20.
Front Microbiol ; 14: 1111965, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36876084

RESUMO

Peanut stem rot, caused by Sclerotium rolfsii, considerably affects crop productivity. Application of chemical fungicides harms the environment and induces drug resistance. Biological agents are valid and eco-friendly alternatives to chemical fungicides. Bacillus spp. are important biocontrol agents that are now widely used against several plant diseases. This study aimed to evaluate the efficacy and mechanism of a potential biocontrol agent Bacillus sp. for controlling peanut stem rot caused by S. rolfsii. Here, we isolated a strain of Bacillus from pig biogas slurry that considerably inhibits the radial growth of S. rolfsii. The strain CB13 was identified as Bacillus velezensis on the basis of morphological, physiological, biochemical characteristics and phylogenetic trees based on the 16S rDNA and gyrA, gyrB, and rpoB gene sequences. The biocontrol efficacy of CB13 was evaluated on the basis of colonization ability, induction of defense enzyme activity, and soil microbial diversity. The control efficiencies of B. velezensis CB13-impregnated seeds in four pot experiments were 65.44, 73.33, 85.13, and 94.92%. Root colonization was confirmed through green fluorescent protein (GFP)-tagging experiments. The CB13-GFP strain was detected in peanut root and rhizosphere soil, at 104 and 108 CFU/g, respectively, after 50 days. Furthermore, B. velezensis CB13 enhanced the defense response against S. rolfsii infection by inducing defense enzyme activity. MiSeq sequencing revealed a shift in the rhizosphere bacterial and fungal communities in peanuts treated with B. velezensis CB13. Specifically, the treatment enhanced disease resistance by increasing the diversity of soil bacterial communities in peanut roots, increasing the abundance of beneficial communities, and promoting soil fertility. Additionally, real-time quantitative polymerase chain reaction results showed that B. velezensis CB13 stably colonized or increased the content of Bacillus spp. in the soil and effectively inhibited S. rolfsii proliferation in soil. These findings indicate that B. velezensis CB13 is a promising agent for the biocontrol of peanut stem rot.

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