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1.
J Cell Mol Med ; 28(10): e18398, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38785203

RESUMO

Behçet's disease (BD) is a complex autoimmune disorder impacting several organ systems. Although the involvement of abdominal aortic aneurysm (AAA) in BD is rare, it can be associated with severe consequences. In the present study, we identified diagnostic biomarkers in patients with BD having AAA. Mendelian randomization (MR) analysis was initially used to explore the potential causal association between BD and AAA. The Limma package, WGCNA, PPI and machine learning algorithms were employed to identify potential diagnostic genes. A receiver operating characteristic curve (ROC) for the nomogram was constructed to ascertain the diagnostic value of AAA in patients with BD. Finally, immune cell infiltration analyses and single-sample gene set enrichment analysis (ssGSEA) were conducted. The MR analysis indicated a suggestive association between BD and the risk of AAA (odds ratio [OR]: 1.0384, 95% confidence interval [CI]: 1.0081-1.0696, p = 0.0126). Three hub genes (CD247, CD2 and CCR7) were identified using the integrated bioinformatics analyses, which were subsequently utilised to construct a nomogram (area under the curve [AUC]: 0.982, 95% CI: 0.944-1.000). Finally, the immune cell infiltration assay revealed that dysregulation immune cells were positively correlated with the three hub genes. Our MR analyses revealed a higher susceptibility of patients with BD to AAA. We used a systematic approach to identify three potential hub genes (CD247, CD2 and CCR7) and developed a nomogram to assist in the diagnosis of AAA among patients with BD. In addition, immune cell infiltration analysis indicated the dysregulation in immune cell proportions.


Assuntos
Aneurisma da Aorta Abdominal , Síndrome de Behçet , Biomarcadores , Biologia Computacional , Análise da Randomização Mendeliana , Humanos , Síndrome de Behçet/genética , Síndrome de Behçet/diagnóstico , Síndrome de Behçet/complicações , Aneurisma da Aorta Abdominal/genética , Aneurisma da Aorta Abdominal/diagnóstico , Biologia Computacional/métodos , Curva ROC , Redes Reguladoras de Genes , Predisposição Genética para Doença , Mapas de Interação de Proteínas/genética , Nomogramas , Receptores CCR7
2.
J Cell Mol Med ; 28(6): e18175, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38451044

RESUMO

The study aimed to identify the biomarkers for predicting coronary atherosclerotic lesions progression in patients with inflammatory bowel disease (IBD). Related transcriptome datasets were seized from Gene Expression Omnibus database. IBD-related modules were identified via Weighted Gene Co-expression Network Analysis. The 'Limma' was applied to screen differentially expressed genes between stable coronary artery disease (CAD) and acute myocardial infarction (AMI). Subsequently, we employed protein-protein interaction (PPI) network and three machine-learning strategies to further screen for candidate hub genes. Application of the receiver operating characteristics curve to quantitatively evaluate candidates to determine key diagnostic biomarkers, followed by a nomogram construction. Ultimately, we performed immune landscape analysis, single-gene GSEA and prediction of target-drugs. 3227 IBD-related module genes and 570 DEGs accounting for AMI were recognized. Intersection yielded 85 shared genes and mostly enriched in immune and inflammatory pathways. After filtering through PPI network and multi-machine learning algorithms, five candidate genes generated. Upon validation, CTSD, CEBPD, CYP27A1 were identified as key diagnostic biomarkers with a superior sensitivity and specificity (AUC > 0.8). Furthermore, all three genes were negatively correlated with CD4+ T cells and positively correlated with neutrophils. Single-gene GSEA highlighted the importance of pathogen invasion, metabolism, immune and inflammation responses during the pathogenesis of AMI. Ten target-drugs were predicted. The discovery of three peripheral blood biomarkers capable of predicting the risk of CAD proceeding into AMI in IBD patients. These identified biomarkers were negatively correlated with CD4+ T cells and positively correlated with neutrophils, indicating a latent therapeutic target.


Assuntos
Doença da Artéria Coronariana , Doenças Inflamatórias Intestinais , Infarto do Miocárdio , Humanos , Doença da Artéria Coronariana/genética , Biomarcadores , Biologia Computacional , Doenças Inflamatórias Intestinais/genética , Aprendizado de Máquina
3.
Brief Bioinform ; 22(4)2021 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-33003203

RESUMO

Quorum sensing interference (QSI), the disruption and manipulation of quorum sensing (QS) in the dynamic control of bacteria populations could be widely applied in synthetic biology to realize dynamic metabolic control and develop potential clinical therapies. Conventionally, limited QSI molecules (QSIMs) were developed based on molecular structures or for specific QS receptors, which are in short supply for various interferences and manipulations of QS systems. In this study, we developed QSIdb (http://qsidb.lbci.net/), a specialized repository of 633 reported QSIMs and 73 073 expanded QSIMs including both QS agonists and antagonists. We have collected all reported QSIMs in literatures focused on the modifications of N-acyl homoserine lactones, natural QSIMs and synthetic QS analogues. Moreover, we developed a pipeline with SMILES-based similarity assessment algorithms and docking-based validations to mine potential QSIMs from existing 138 805 608 compounds in the PubChem database. In addition, we proposed a new measure, pocketedit, for assessing the similarities of active protein pockets or QSIMs crosstalk, and obtained 273 possible potential broad-spectrum QSIMs. We provided user-friendly browsing and searching facilities for easy data retrieval and comparison. QSIdb could assist the scientific community in understanding QS-related therapeutics, manipulating QS-based genetic circuits in metabolic engineering, developing potential broad-spectrum QSIMs and expanding new ligands for other receptors.


Assuntos
Bactérias/química , Bases de Dados de Compostos Químicos , Percepção de Quorum , 4-Butirolactona/análogos & derivados , 4-Butirolactona/química , 4-Butirolactona/metabolismo , Bactérias/metabolismo
4.
J Vasc Surg ; 77(6): 1822-1832.e3, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37232176

RESUMO

OBJECTIVE: To compare the risk of mortality and complications between male and female patients undergoing aortic aneurysm repair with fenestrated-branched endovascular aortic repair (FBEVAR). METHODS: The PubMed, Embase, and Scopus databases were searched systematically for observational studies in patients undergoing elective fenestrated branched endovascular repair for aortic aneurysm. The included studies compared outcomes of interest based on the sex of the patients. The pooled effect sizes were reported as odds ratio (OR) and weighted mean difference (WMD). STATA software was used for statistical analysis. RESULTS: The meta-analysis included nine studies. Compared with males, females had a higher risk of perioperative and in-hospital mortality (OR, 3.01; 95% confidence interval [CI], 2.01-4.53), mortality within 1 year postoperatively (OR, 1.79; 95% CI, 1.09-2.93) and mortality at more than 1 year postoperatively (OR, 1.31l 95% CI, 1.02-1.69). Female patients had significantly higher operative time (minutes) (WMD, 33.77; 95% CI, 12.01-55.52), length of hospital stay (days) (WMD, 2.29; 95% CI, 1.52-3.07), and the risk of major complications (OR, 2.93; 95% CI, 1.36-6.32) There was an increased risk of respiratory complications (OR, 1.70; 95% CI, 1.20-2.40), renal complications (OR, 2.68; 95% CI, 1.25-5.74), stroke (OR, 2.74; 95% CI, 1.44-5.22), sepsis (OR, 2.24; 95% CI, 1.23-4.09), and ischemic colitis (OR, 2.63; 95% CI, 1.48-4.68) in female patients, and they were less likely to be discharged home postoperatively (OR, 0.58; 95% CI, 0.43-0.77). CONCLUSIONS: In patients undergoing FBEVAR, female sex is associated with higher risk of mortality and complications. These findings suggest the need for careful supervision and management by multidisciplinary team in females undergoing FBEVAR.


Assuntos
Aneurisma da Aorta Abdominal , Aneurisma da Aorta Torácica , Aneurisma Aórtico , Implante de Prótese Vascular , Procedimentos Endovasculares , Humanos , Masculino , Feminino , Prótese Vascular/efeitos adversos , Aneurisma da Aorta Torácica/cirurgia , Implante de Prótese Vascular/efeitos adversos , Procedimentos Endovasculares/efeitos adversos , Resultado do Tratamento , Complicações Pós-Operatórias , Fatores de Risco , Aneurisma Aórtico/diagnóstico por imagem , Aneurisma Aórtico/cirurgia , Aneurisma Aórtico/complicações , Aneurisma da Aorta Abdominal/diagnóstico por imagem , Aneurisma da Aorta Abdominal/cirurgia , Aneurisma da Aorta Abdominal/complicações
5.
J Nat Prod ; 86(1): 199-208, 2023 01 27.
Artigo em Inglês | MEDLINE | ID: mdl-36635870

RESUMO

Fifteen compounds including nine new diterpenes were isolated from the roots of Croton yunnanensis. By HRESIMS, NMR, ECD data, and X-ray diffraction analysis, the new compounds were characterized as eight neo-clerodane diterpenes (compounds 1-8) and one 15,16-dinor-ent-pimarane diterpene (9). All diterpenes were assayed for their hypoglycemic activities. Compounds 1-4, 6, 7, and 10 promoted glucose uptake activity in insulin-resistant 3T3-L1 adipocytes. Compounds 1 and 6 showed insulin sensitizing activity, potentiating conspicuously their glucose uptake activity at a concentration of 20 µM when treated synergistically with low-concentration insulin at 1 nM.


Assuntos
Croton , Diterpenos Clerodânicos , Diterpenos , Insulinas , Croton/química , Hipoglicemiantes/farmacologia , Diterpenos/farmacologia , Diterpenos/química , Diterpenos Clerodânicos/química , Glucose , Estrutura Molecular
6.
J Nat Prod ; 85(2): 405-414, 2022 02 25.
Artigo em Inglês | MEDLINE | ID: mdl-35080403

RESUMO

Thirty-five tigliane diterpenoids and two ent-kaurane diterpenoids were isolated from the leaves of Croton damayeshu, and, among them, compounds 1-10 were characterized as new tigliane diterpenoids. The structures of compounds 1-10 were determined by analysis of their HRESIMS, NMR, and ECD data and by chemical methods. The isolates were assayed for their larvicidal, antifungal, and α-glucosidase inhibitory activities, and compounds 8-10 were found to possess larvicidal activities against Plutella xylostella with LC50 values of 0.19, 0.16, and 0.26 µM, respectively, comparable to the LC50 of 0.14 µM for the positive control, flubendiamide.


Assuntos
Croton , Diterpenos do Tipo Caurano , Diterpenos , Forbóis , Antifúngicos/farmacologia , Croton/química , Diterpenos/química , Diterpenos do Tipo Caurano/farmacologia , Estrutura Molecular , alfa-Glucosidases
7.
J Environ Manage ; 303: 114140, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34836676

RESUMO

Species diversity plays an essential role in enhancing ecosystem functions (EF) in both natural and plantation forests. However, we do not fully understand whether species diversity could maintain the sustainability of EFs in multiple-rotation plantations. Here, we hypothesized that tree species mixtures could mitigate declines in EFs along successive rotations, but could not maintain ecosystem multifunctionality. To test our hypothesis, we examined the effects of species diversity on four EFs, i.e., aboveground biomass (AGB), soil available nitrogen (SAN) and phosphorus (SAP), and soil organic matter (SOM), based on pure model simulation in plantations of subtropical China. The model fusion framework was set up by the integration of the process-based FORECAST and Multivariate Diversity-Interactions models. In the simulation, four local typical plantation tree species (two conifers, one evergreen broadleaf, and one deciduous N-fixing broadleaf) were selected and combined to form four monoculture and 11 mixture stands, and for each stand, the simulation was made for four 25-year rotations. The results showed that all the four EFs declined with the progress of rotations in both monoculture and mixtures, and the declining range was larger in monoculture than in mixtures in each rotation. Particularly, SAP significantly decreased while AGB, SAN, and SOM increased with diversity evenness from 0 (monoculture) to 1 (four species being equal abundant in the mixture). Overall, SAP and AGB displayed higher sensitivity to the disturbance of successive rotations compared with SAN and SOM. These results suggest that mixing species could not maintain EFs along with successive rotations because it could not alleviate SAP deficiencies in the soils resulted from the disturbances of silvicultural measures.


Assuntos
Ecossistema , Florestas , Biodiversidade , Biomassa , China , Nutrientes , Solo , Árvores
8.
Anal Chem ; 93(38): 12987-12994, 2021 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-34520172

RESUMO

Process analysis of heterogeneous catalytic reactions such as lignin depolymerization is essential to understand the reaction mechanism at the molecular level, but it is always challenging due to harsh conditions. Herein, we report an operando process analysis strategy by combining a microbatch reactor with high-resolution mass spectrometry (MS) via a reactor-integrated electrospray ionization (R-ESI) technique. R-ESI-MS expands the applications of traditional in situ MS to a heterogeneous and high-pressure liquid-phase system. With this strategy, we present the evolution of a series of monomers, dimers, and oligomers during lignin depolymerization under operando conditions (methanol solvent, 260 °C, ∼8 MPa), which is the first experimental elucidation of a progressive depolymerization pathway and evidence of repolymerization of active monomers. The proposed R-ESI-MS is crucial in probing depolymerization intermediates of lignin; it also provides a flexible strategy for process analysis of heterogeneous catalytic reactions under operando conditions.


Assuntos
Lignina , Espectrometria de Massas por Ionização por Electrospray , Catálise , Metanol , Solventes
9.
Metab Eng ; 67: 186-197, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34229080

RESUMO

Quorum sensing (QS) offers cell density dependent dynamic regulations in cell culture through devices such as synchronized lysis circuit (SLC) and metabolic toggle switch (MTS). However, there is still a lack of studies on cocultivation with a combination of different QS-based devices. Taking the production of isopropanol and salidroside as case studies, we have mathematically modeled a comprehensive set of QS-regulated cocultivation schemes and constructed experimental combinations of QS devices, respectively, to evaluate their feasibility and optimality for regulating growth competition and corporative production. Glucose split ratio is proposed for the analysis of competition between cell growth and targeted production. Results show that the combination of different QS devices across multiple members offers a new tool with the potential to effectively coordinate synthetic microbial consortia for achieving high product titer in cross-feeding cocultivation. It is also evident that the performance of such systems is significantly affected by dynamic characteristics of chosen QS devices, carbon source control and the operational settings. This study offers insights for future applications of combinational QS devices in synthetic microbial consortia.


Assuntos
Consórcios Microbianos , Percepção de Quorum , Técnicas de Cocultura
10.
Cell Mol Life Sci ; 77(7): 1319-1343, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31612240

RESUMO

Quorum sensing (QS), a microbial cell-to-cell communication process, dynamically regulates a variety of metabolism and physiological activities. In this review, we provide an update on QS applications based on autoinducer molecules including acyl-homoserine lactones (AHLs), auto-inducing peptides (AIPs), autoinducer 2 (AI-2) and indole in population-level control of bacteria, and highlight the potential in developing novel clinical therapies. We summarize the development in the combination of various genetic circuits such as genetic oscillators, toggle switches and logic gates with AHL-based QS devices in Gram-negative bacteria. An overview is then offered to the state-of-the-art of much less researched applications of AIP-based QS devices with Gram-positive bacteria, followed by a review of the applications of AI-2 and indole based QS for interspecies communication among microbial communities. Building on these general-purpose QS applications, we highlight the disruptions and manipulations of QS devices as potential clinical therapies for diseases caused by biofilm formation, antibiotic resistance and the phage invasion. The last part of reviewed literature is dedicated to mathematical modelling for QS applications. Finally, the key challenges and future perspectives of QS applications in monoclonal synthetic biology and synthetic ecology are discussed.


Assuntos
Bactérias/crescimento & desenvolvimento , Percepção de Quorum , Biofilmes/crescimento & desenvolvimento , Microbioma Gastrointestinal , Lógica , Percepção de Quorum/genética , Especificidade da Espécie
11.
J Insect Sci ; 21(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33394047

RESUMO

Parasites obtain energy and nutrients from the host, and their body size is also usually limited by host size. However, the regulatory mechanisms that control the plasticity of parasite body sizes and the stoichiometric relationships with their hosts remain unclear. Here we investigated the concentrations of 14 elements (C, H, O, N, P, S, K, Na, Ca, Mg, Al, Fe, Mn, and Zn) in the acorns of three oak species (Quercus spp.), in their endoparasitic weevil (Curculio davidi Fairmaire) (Coleoptera: Curculionidae) larvae and in the larval feces, and the weight of weevil larvae within different hosts in a warm-temperate zone of China. Our results showed that the three acorn species exhibited significant differences in C, H, O, P, K, Mg, and Mn concentrations. However, in the weevil larvae, only P, Mn, and C:P ratio revealed significant differences. Weevil larvae preferentially absorbed and retained N, Zn, Na, and P, whereas Mn, K, Ca, and O were passively absorbed and transported. The weevil larvae weight was associated with acorn stoichiometry, and positively correlated with acorn size. Weevil larvae P decreased, but Mn and C:P increased with their weight, implying highly variable in somatic stoichiometry are coupled with the plasticity of body size. Interestingly, weevil larvae weight was negatively correlated with acorn infection rate, indicating small-size parasitic insects might have higher fitness level in parasite-host systems than larger-size ones. Our results suggest that variation in P, Mn, and C:P in parasites may play critical roles in shaping their body size and in improving their fitness.


Assuntos
Cadeia Alimentar , Herbivoria , Nutrientes/fisiologia , Quercus , Gorgulhos/fisiologia , Adaptação Fisiológica , Fenômenos Fisiológicos da Nutrição Animal , Animais , Tamanho Corporal , China , Larva/crescimento & desenvolvimento , Larva/fisiologia , Especificidade da Espécie , Gorgulhos/crescimento & desenvolvimento
12.
Angew Chem Int Ed Engl ; 60(5): 2643-2647, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33090647

RESUMO

The phenolic pool is considered to be an important intermediate during the catalytic conversion of biomass. However, no direct evidence has been reported on its full picture on a molecular level due to the huge challenges in probing the reactive and lowly volatile phenolic oligomers with state-of-the-art technologies. Herein, we report the online detection and structural identification of a phenolic pool by utilizing in-situ atmospheric-pressure photoionization mass spectrometry, demonstrating that the phenolic pool is formed through repolymerization of monomers with an equidistant group pattern and acts as a key mechanistic step for both valuable aromatic products and undesired coke. The exploration of the real reactive species is also of great importance for the rational design and synthesis of advanced catalysts with high activity.

13.
BMC Plant Biol ; 20(1): 389, 2020 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-32842952

RESUMO

BACKGROUND: Phosphorus (P) -rich soils develop in phosphorite residing areas while P-deficient soils are ubiquitous in subtropical regions. Little has been reported that how metabolites participate in the seed development and the processes involved in their coping with contrasting-nutrient environments. RESULTS: Here we quantified the metabolites of Quercus variabilis acorns in the early (July), middle (August), late (September) development stages, and determined element (C, H, O, N, P, K, Ca, Mg, S, Fe, Al, Mn, Na, Zn, and Cu) concentrations of acorns in the late stage, at geologically-derived contrasting-P sites in subtropical China. The primary metabolic pathways included sugar metabolism, the TCA cycle, and amino acid metabolism. Most metabolites (especially C- and N-containing metabolites) increased and then decreased from July to September. Acorns between the two sites were significantly discriminated at the three stages, respectively, by metabolites (predominantly sugars and organic acids). Concentrations of P, orthophosphoric acid and most sugars were higher; erythrose was lower in late-stage acorns at P-rich sites than those at P-deficient sites. No significant differences existed in the size and dry mass of individual acorns between oak populations at the two sites. CONCLUSIONS: Oak acorns at the two sites formed distinct metabolic phenotypes related to their distinct geologically-derived soil conditions, and the late-stage acorns tended to increase P-use-efficiency in the material synthesis process at P-deficient sites, relative to those at P-rich sites.


Assuntos
Fósforo/metabolismo , Quercus/crescimento & desenvolvimento , Quercus/metabolismo , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Solo/química , China , Germinação/fisiologia , Estações do Ano
14.
Biomacromolecules ; 21(6): 2087-2095, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32267674

RESUMO

Zwitterionic peptides are great candidates as antifouling coating materials in many biomedical applications. We investigated the structure and antifouling properties of surface-tethered zwitterionic peptide monolayers with different peptide chain lengths and charge distributions using a combination of surface plasma resonance, atomic force microscopy, and all atomistic molecular dynamics (MD) simulation techniques. Our results demonstrate that zwitterionic peptides with more zwitterionic lysine (K) and glutamic acid (E) repeating units exhibit better antifouling performance. The block charge distributions of the positive and negative charges in the peptides (having multiple positive charges next to the same amount of negative charges), although affecting the structure of the peptide molecules, do not significantly change the antifouling properties of the peptide monolayers in the solutions containing monovalent ions. However, divalent cations, Ca2+ and Mg2+, in solution can significantly alter the structure and lower the antifouling performance of the zwitterionic peptide monolayers, especially with the sequences of block charges. All atomistic MD simulations quantitatively reveal that the divalent cations in solution lead to more interchain electrostatic cross-links between peptide chains, especially for peptides with block charges, which causes dehydration of the zwitterionic peptides and diminishes their antifouling performances.


Assuntos
Incrustação Biológica , Incrustação Biológica/prevenção & controle , Cátions Bivalentes , Íons , Simulação de Dinâmica Molecular , Peptídeos
15.
J Environ Manage ; 241: 293-304, 2019 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-31009817

RESUMO

Livestock production is important for food security, nutrition, and landscape maintenance, but it is associated with several environmental impacts. To assess the risk and benefits arising from livestock production, transparent and robust indicators are required, such as those offered by life cycle assessment. A central question in such approaches is how environmental burden is allocated to livestock products and to manure that is re-used for agricultural production. To incentivize sustainable use of manure, it should be considered as a co-product as long as it is not disposed of, or wasted, or applied in excess of crop nutrient needs, in which case it should be treated as a waste. This paper proposes a theoretical approach to define nutrient requirements based on nutrient response curves to economic and physical optima and a pragmatic approach based on crop nutrient yield adjusted for nutrient losses to atmosphere and water. Allocation of environmental burden to manure and other livestock products is then based on the nutrient value from manure for crop production using the price of fertilizer nutrients. We illustrate and discuss the proposed method with two case studies.


Assuntos
Fertilizantes , Esterco , Agricultura , Animais , Produção Agrícola , Gado
16.
J Insect Sci ; 152015.
Artigo em Inglês | MEDLINE | ID: mdl-25843579

RESUMO

Body size can be an important factor controlling consumer stoichiometry. In holometabolous insects, body size is typically associated with nutrient storage. Consumer stoichiometry is known to vary within species across a range of body sizes; however, the contribution of nutrient storage to this variation is not well understood. We used the fifth-instar larvae of the oak weevil (Coleoptera: Curculio davidi Fairmaire), which is characterized by a high capacity for nutrient storage, to investigate the effect of shifts in nutrient storage with body mass on variations in larva stoichiometry. Our results showed that weevil larvae with larger body mass had a lower carbon (C) content, reflecting decreases in the sequestration rate of C-rich lipids. Larger larvae had elevated concentrations of nitrogen (N), sulfur (S), and protein. The similar patterns of variation in elemental composition and macromolecule storage with body weight indicate that the shift in nutrient storage is the main factor causing the variation in larval stoichiometry with body weight. This finding was further supported by the low variation in residual larval biomass C, N, and S concentrations after lipid extraction. These results help decipher the physiological mechanism of stoichiometric regulation in growing organisms.


Assuntos
Carbono/metabolismo , Proteínas de Insetos/metabolismo , Metabolismo dos Lipídeos , Nitrogênio/metabolismo , Enxofre/metabolismo , Gorgulhos/metabolismo , Animais , Peso Corporal , Diapausa de Inseto , Larva/crescimento & desenvolvimento , Larva/metabolismo , Gorgulhos/crescimento & desenvolvimento
17.
Polymers (Basel) ; 16(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38201826

RESUMO

In order to achieve the high-value utilization of heavy tar for the production of enhanced-performance graphite foam carbon, the carbon mesophase was ready from the heavy component of low-temperature coal tar, and the coal tar was modified by styrene-butadiene-styrene (SBS), polyethylene (PE) and ethylene-vinyl-acetate (EVA) copolymers. The order degree of the carbonite mesophase was analyzed using a polarizing microscope test, Fourier transform infrared spectroscopy and X-ray diffraction to screen out the most suitable copolymer type and addition amount. Furthermore, the mechanism of modification by this copolymer was analyzed. The results showed that adding SBS, PE and EVA to coal tar would affect the order of carbonaceous mesophase; however, at an addition rate of 10.0 wt.%, the linear-structure SBS copolymer with a styrene/butadiene ratio (S/B) of 30/70 exhibited the optimal degree of ordering in the carbonaceous mesophase. Its foam carbon prepared by polymer modification is the only one that forms a graphitized structure, with d002 of 0.3430 nm, and the maximum values of Lc and La are 3.54 nm and 2.22 nm, respectively. This is because, under elevated pressure and high-temperature conditions, SBS underwent chain scission, releasing a more significant number of methyl and other free radicals that interacted with the coal tar constituents. As a result, it reduced the affinity density of heavy coal tar molecules, enhanced fluidity, promoted the stacking of condensed aromatic hydrocarbons and increased the content of soluble carbonaceous mesophase, ultimately leading to a more favorable alignment of the carbonaceous mesophase.

18.
Sci Rep ; 14(1): 9844, 2024 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-38684880

RESUMO

Since the basic rail of the switch needs to have a certain bending angle when the train changes direction, top bending is an important link in the production process of the basic rail. The three-point pressure top bending method is simple, flexible and widely used. In this study, the traditional three-point pressure bending is optimized, the influence of the pick width in the model is considered, a corresponding rebound model is established, and the model is applied to the pressure bending process of the basic rail. The bilinear strengthening model of the material was used to construct the bending moment expressions at different positions during the top bending process, and the relationship between the load and bending deflection in the elastic stage and elastic-plastic stage was obtained. The final top bending prediction model was obtained by combining the load-deflection model in the bending stage and the rebound stage. The correctness of the theoretical mathematical model was verified by establishing finite element simulations, and the theoretical calculation results were compared with the experimental results. The results showed that the top bend prediction optimization model established in this study had high feasibility and met the machining accuracy requirements.

19.
J Cancer ; 15(12): 3809-3824, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38911365

RESUMO

Background: Emerging evidence has indicated that long noncoding RNAs (lncRNAs) are associated with the development and progression of several carcinomas, including hepatocellular carcinoma (HCC). However, the role of LINC01535 in HCC is still unknown. Materials and methods: In this study, RNA-seq, CCK-8, colony formation, wound healing, Transwell and tumor xenograft assays were used to explore the function of LINC01535 in the proliferation and metastasis of HCC in vitro and in vivo. Fluorescence in situ hybridization (FISH) assay, bioinformatics analysis, dual-luciferase assay, quantitative real-time polymerase chain reaction (qRT-PCR), and western blot analysis were used to reveal the interactions of LINC01535, miR-214-3p and VASP. Results: LINC01535 was overexpressed in HCC tissues and HCC cell lines. Gain- and loss-of-function studies revealed that LINC01535 could promote HCC cell proliferation, migration and invasion both in vitro and in vivo. In addition, upregulation of LINC01535 significantly decreased the expression of microRNA-214-3p (miR-214-3p), which was found closely associated with suppressing tumor progression. Moreover, VASP was identified as a direct downstream target gene of miR-214-3p. LINC01535 positively regulated VASP expression by sponging miR-214-3p, and VASP overexpression activated the PI3K/AKT signaling pathway and stimulated epithelial-to-mesenchymal transition (EMT) in HCC. Conclusions: Our study first found that LINC01535 promoted HCC progression by regulating its downstream target, the miR-214-3p/VASP axis, via the PI3K/AKT signaling pathway. The function and novel regulatory mechanism of LINC01535 may provide a valuable target for the diagnosis and treatment of HCC patients.

20.
Materials (Basel) ; 17(7)2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38612128

RESUMO

This study focuses on using activated fly ash to preparate silica aerogel by the acid solution-alkali leaching method and ambient pressure drying. Additionally, to improve the performance of silica aerogel, C6H16O3Si (KH-570) and CH3Si(CH3O)3 (MTMS) modifiers were used. Finally, this paper investigated the factors affecting the desilication rate of fly ash and analyzed the structure and performance of silica aerogel. The experimental results show that: (1) The factors affecting the desilication rate are ranked as follows: hydrochloric acid concentration > solid-liquid ratio > reaction temperature > reaction time. (2) KH-570 showed the best performance, and when the volume ratio of the silica solution to it was 10:1, the density of silica aerogel reached a minimum of 183 mg/cm3. (3) The optimal process conditions are a hydrochloric acid concentration of 20 wt%, a solid-liquid ratio of 1:4, a reaction time of two hours, and a reaction temperature of 100 °C. (4) The optimal performance parameters of silica aerogel were the thermal conductivity, specific surface area, pore volume, average pore size, and contact angle values, with 0.0421 W·(m·K)-1, 487.9 m2·g-1, 1.107 cm3·g-1, 9.075 nm, and 123°, respectively. This study not only achieves the high-value utilization of fly ash, but also facilitates the effective recovery and utilization of industrial waste.

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