Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
Más filtros












Base de datos
Intervalo de año de publicación
1.
Front Plant Sci ; 15: 1297812, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38434433

RESUMEN

Introduction: The potato (Solanum tuberosum L.), one of the most vital food crops worldwide, is sensitive to salinity. Brassinosteroids (BRs) are crucial in tolerance to various abiotic stresses. The constitutive photomorphogenesis and dwarf (CPD) gene encodes C-3 oxidase, which is a rate-limiting enzyme that controls the synthesis of BRs. Methods: In this study, we used StCPD gene overexpression (T) and un-transgenic (NT) plants obtained from our former research to illustrate adaptive resistance to salt stress at levels of phenotype; cell ultrastructure, physiology, and biochemistry; hormone; and transcription. Results: Results showed the accumulation of 2,4-epibrassionolide (EBL) in T potatoes. We found that under high salt situations, the changed Na+/K+ transporter gene expression was linked with the prevalent ionic responses in T plants, which led to lower concentrations of K+ and higher concentrations of Na+ in leaves. Furthermore, RNA-sequencing (RNA-seq) data elucidated that gene expressions in NT and T plants were significantly changed with 200-mM NaCl treatment for 24 h and 48 h, compared with the 0-h treatment. Functional enrichment analysis suggested that most of the differentially expressed genes (DEGs) were related to the regulation of BR-related gene expression, pigment metabolism process, light and action, and plant hormone signal transduction. Discussion: These findings suggested that StCPD gene overexpression can alleviate the damage caused by salt stress and enhance the salt resistance of potato plantlets. Our study provides an essential reference for further research on BR regulation of plant molecular mechanisms in potatoes with stress tolerance.

2.
Sci Rep ; 14(1): 5026, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38424248

RESUMEN

In this article, an engineering problem of three co-rotating exciters with the circular distribution in a vibrating system is investigated. The dynamical model constructed by the motion differential equations is established. By introducing the small parameter averaged method in the dynamic equation, the synchronization and stability conditions of the electromechanical coupling dynamical model is derived. To illustrate the necessity of the controlling method, the self-synchronization of the vibrating system is firstly analyzed with the theory, numerical simulations and experiments. With the self-synchronization results, it is indicated that the ellipse trajectory which is needed in the industry can't be realizefd by the self-synchronization motion of the vibrating system. And then, a fuzzy PID controlling method based on the master-slave controlling strategy is introduced in the vibrating system to realize the controlled synchronization. The Lyapunov stability criterion is given to certify the stability of the controlling system. Through some simulations and experiments, the effectiveness of controlled synchronization is illustrated in the discussion. Finally, the present work illuminates the feasibility and practicality for designing some new types of vibrating screens in the industry.

3.
J Org Chem ; 89(3): 1465-1472, 2024 02 02.
Artículo en Inglés | MEDLINE | ID: mdl-38251869

RESUMEN

Enzyme-catalyzed dynamic kinetic resolution was applied to the one-pot regio- and enantioselective synthesis of 2,5-disubstituted tetrazole hemiaminal esters, among which 72% of the products were obtained in excellent enantiopurities (99% ees). Tunable stereoselectivity was achieved by using different types of enzymes during the synthesis of a key intermediate for a clinic drug candidate. Successful preparation of tetrazole ester prodrugs and high catalyst recyclability further demonstrated the potential practical application of this protocol.


Asunto(s)
Ésteres , Tetrazoles , Estereoisomerismo , Biocatálisis , Catálisis
4.
PLoS One ; 18(11): e0294726, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37988368

RESUMEN

With a requirement of miniaturization in modern vibrating screens, the vibration synchronization method can no longer meet the process demand, so the controlled synchronization method is introduced in the vibrating screen to achieve zero phase error state and realize the purpose of increasing the amplitude. In this article, the controlled synchronization of a vibrating screen driven by two motors based on improved sliding mode controlling method is investigated. Firstly, according to the theory of mechanical dynamics, the motion state of the vibrating screen is simplified as the electromechanical coupling dynamical model of a vibrating system driven by two inductor motors. And then the synchronization conditions and stability criterion of the vibrating system are derived and numerically analyzed. Based on a master-slave controlling strategy, the controllers of two motors are respectively designed with Super-Twisting sliding mode control (ST-SMC) and backstepping second-order complementary sliding mode control (BSOCSMC), while the uncertainty is estimated by an adaptive radial basis function neural network (ARBFNN). In addition, Lyapunov stability analysis is performed on the two controllers to prove their stability theoretically. Finally, simulation analysis is conducted based on the dynamics model in this paper.


Asunto(s)
Redes Neurales de la Computación , Vibración , Simulación por Computador , Movimiento (Física) , Incertidumbre
5.
Clin Nucl Med ; 48(12): e614-e616, 2023 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-37883213

RESUMEN

ABSTRACT: A 31-year-old man with multiple intrahepatic inflammatory myofibroblastoma tumor was referred to nuclear medicine department to assess its malignant potential. Multiple lesions in the liver exhibited 68 Ga-FAPI uptake at different degrees. Instead, there was no abnormal 18 F-FDG activity in the other hepatic lesions under the normal liver background except for the puncture site. This case reflects tumor heterogeneity of the disease and shows the potential value of 68 Ga-FAPI PET/CT for the evaluation of hepatic inflammatory myofibroblastoma tumor.


Asunto(s)
Neoplasias Hepáticas , Neoplasias de Tejido Muscular , Masculino , Humanos , Adulto , Fluorodesoxiglucosa F18 , Tomografía Computarizada por Tomografía de Emisión de Positrones , Tomografía de Emisión de Positrones
6.
ACS Omega ; 8(34): 31246-31255, 2023 Aug 29.
Artículo en Inglés | MEDLINE | ID: mdl-37663515

RESUMEN

During the production process of coalbed methane, the generation and migration of coal fines can obstruct fractures in coal reservoirs and reduce their permeability. In order to investigate the effects of coal fines migration on the porosity and permeability of coal reservoirs, we conducted core water flooding experiments, low-field nuclear magnetic resonance (NMR), and low-temperature N2 adsorption experiments to study the variations in porosity and permeability of cataclastic coal during coal fines migration and the impact of coal fines migration on porosity and permeability. The experimental results reveal that the initial porosity ratio of cataclastic coal exhibits the characteristics of micropore > macropore > transitional pore > mesopore, with the pore types being predominantly fissured. The porosity of pores larger than 1000 nm and those larger than 10,000 nm exhibit consistent trends before and after water flooding, indicating that the blockage or unblocking of pores with radius larger than 10,000 nm by coal fines can also cause blockage or unblocking of some interconnected macropore. The early stage of flooding is the main period for coal fines migration and production in cataclastic coal, during which the mass concentration of coal fines production is higher and some macropores and fractures become blocked, resulting in a larger decrease in porosity. The higher the initial permeability of cataclastic coal samples with a larger end-face fracture density, the more similar the variations in porosity and permeability of pores larger than 10,000 nm during the flooding experiment, indicating that coal fines mainly block interconnected pores and fractures with radius larger than 10,000 nm through migration, thereby reducing permeability. This study provides a theoretical basis for the efficient production of coalbed methane.

7.
Micromachines (Basel) ; 14(5)2023 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-37241627

RESUMEN

Diamond wire sawing is the main processing method for hard and brittle materials, but the unreasonable matching of process parameters will reduce its cutting ability and stability. In this paper, the asymmetric arc hypothesis of a wire bow model is proposed. Based on this hypothesis, an analytical model of the wire bow between the process parameters and the wire bow parameters was established and verified with a single-wire cutting experiment. The model considers the asymmetry of the wire bow in diamond wire sawing. The tension at both ends of the wire bow is called the endpoint tension; by calculating the difference in tension between the two ends, a reference for the cutting stability and a tension range for the selection of the diamond wire were provided. The model was used to calculate the wire bow deflection and the cutting force, providing theoretical guidance for the matching of process parameters. Based on the theoretical analysis of the cutting force, endpoint tension and wire bow deflection, the cutting ability, cutting stability, and the risk of wire cutting were predicted.

8.
Foods ; 12(7)2023 Mar 29.
Artículo en Inglés | MEDLINE | ID: mdl-37048262

RESUMEN

The effects of drying temperature and air velocity on the drying characteristics, color, bioactive compounds, rehydration ratio, and microstructure of Ophiopogonis Radix during hot air impingement drying (HAID) were explored in the current study. The experimental results showed that the drying temperature and air velocity had a significant impact on the drying characteristics and quality attributes of dried products except for the rehydration ratio. The drying time decreased from 720 to 240 min with the increase of drying temperature from 50 to 70 °C. Increasing the air velocity from 6 to 12 m/s enhanced the drying process of Ophiopogonis Radix, while the extension of air velocity to 15 m/s lowered the drying rate. The samples that were dried at a lower drying temperature obtained lower color difference. Properly increasing the drying temperature or air velocity could increase the total polysaccharide and flavonoid contents of dried products. Additionally, a back-propagation neural network (BPNN) model was developed to predict the moisture ratio of Ophiopogonis Radix during the drying process. The optimal BPNN with 3-11-1 topology were obtained to predict the moisture ratio of Ophiopogonis Radix during HAID and performed with an acceptable performance.

9.
Foods ; 12(6)2023 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-36981240

RESUMEN

Effects of vacuum freeze drying (VFD), air impingement drying (AID), hot air drying based on temperature and humidity control (TH-HAD), pulsed vacuum drying (PVD), and medium- and short-wave infrared radiation drying (MSIRD) on the drying characteristics and physicochemical properties of garlic slices were investigated in the current work. Based on the experimental results, the Weibull model fitted the experimental results better (R2 > 0.99) than the Wang and Singh model. Samples dried with PVD showed the smallest color difference (ΔE*), better rehydration capacity and desirable reducing sugar content. In response to thermal effects and pressure pulsations, the cell walls gradually degraded, and the cell and organelle membranes ruptured. The allicin and soluble pectin contents of garlic slices treated with PVD were higher by 8.0-252.3% and 49.5-92.2%, respectively, compared to those of the samples dried by other techniques. VFD maintained a complete garlic slice structure with the minimum shrinkage and the best appearance. The MSIRD process produced the densest structure, and caused an additional loss of color and phytochemical contents. The findings in current work implied that PVD could be a promising drying technique for garlic slices.

10.
Sci Rep ; 13(1): 2467, 2023 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-36774384

RESUMEN

In this article, multifrequency controlled synchronization of four inductor motors by the fixed frequency ratio method in a vibration system is investigated. The electromechanical coupling dynamical model of the vibrating system is established. The synchronous condition of the vibrating system is obtained with the small parameter method. Through the theoretical derivation and numerical simulation, multifrequency self-synchronization of four induction motors in the vibration system can't be realized. To achieve the purpose of multifrequency synchronization motion, the method of multifrequency controlled synchronization is proposed, and a fuzzy PID controlling method is introduced. The stability of the controlling system is certified by the Lyapunov criterion. An arbitrariness of the proposed controlling method which is applied to the vibration system is presented. To certify the accuracy of the theory and simulation, a vibrating test bench is constructed. Some experiments are operated to validate the effectiveness and the proposed controlled synchronization method.

11.
Micromachines (Basel) ; 13(11)2022 Nov 19.
Artículo en Inglés | MEDLINE | ID: mdl-36422455

RESUMEN

Diamond wire sawing is the main machining technology for slicing various brittle materials, such as crystalline silicon, SiC, and NdFeB. Due to their high hardness and high brittleness, as well as the ease with which the surfaces of machined materials are damaged, it is difficult to further improve the sawing efficiency and the surface quality based on research conducted on the original machining method. In this paper, a vibration-assisted diamond wire sawing method is proposed. We analyzed the impact of load on the ingot, motion trajectory, and sawing depth of the abrasive particles, and a macroscopic sawing force prediction model for the vibration-assisted sawing method was established and verified via experiments. Based on the single-wire-sawing experiment and prediction model, the influences of the vibration parameters and sawing parameters on the sawing force were determined. The influences of vibration assistance on the surface quality, including the roughness profile, waviness profile, thickness profile, Ra, and Rz, were explored through single-wire-sawing experiments, and the influences of vibration assistance on the geometric parameters of slices, such as the total thickness variation (TTV) and warp, were explored through multi-wire-sawing experiments. It was found that vibration-assisted sawing can reduce sawing force and improve surface quality.

12.
Int J Mol Sci ; 23(21)2022 Nov 04.
Artículo en Inglés | MEDLINE | ID: mdl-36362305

RESUMEN

As a highly conserved family of plant-specific proteins, SIMILAR-TO-RCD-ONE (SROs) play an essential role in plant growth, development and response to abiotic stresses. In this study, six StSRO genes were identified by searching the PARP, RST and WWE domains based on the genome-wide data of potato database DM v6.1, and they were named StSRO1-6 according to their locations on chromosomes. StSRO genes were comprehensively analyzed using bioinformatics methods. The results showed that six StSRO genes were irregularly distributed on five chromosomes. Phylogenetic analysis showed that 30 SRO genes of four species were distributed in three groups, while StSRO genes were distributed in groups II and III. The promoter sequence of StSRO genes contained many cis-acting elements related to hormones and stress responses. In addition, the expression level of StSRO genes in different tissues of doubled monoploid (DM) potato, as well as under salt, drought stresses and hormone treatments, was analyzed by RNA-seq data from the online database and quantitative real-time polymerase chain reaction (qRT-PCR) analysis. Furthermore, the expression level of StSRO genes was analyzed by transcriptome analysis under mild, moderate and severe salt stress. It was concluded that StSRO genes could respond to different abiotic conditions, but their expression level was significantly different. This study lays a foundation for further studies on the biological functions of the StSRO gene family.


Asunto(s)
Solanum tuberosum , Solanum tuberosum/metabolismo , Regulación de la Expresión Génica de las Plantas , Filogenia , Familia de Multigenes , Proteínas de Plantas/metabolismo , Estrés Fisiológico/genética , Perfilación de la Expresión Génica
13.
Plants (Basel) ; 11(19)2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36235366

RESUMEN

In order to explore an alternative drying method to enhance the drying process and quality of persimmon slices, pulsed vacuum drying (PVD) was employed and the effects of different drying temperatures (60, 65, 70, and 75 °C) on drying kinetics, color, rehydration ratio (RR), microstructure, bioactive compounds, and the antioxidant capacity of sliced persimmons were investigated in the current work. Results showed that the rehydration ratio (RR) of the samples under PVD was significantly higher than that of the traditional hot air-dried ones. Compared to the fresh samples, the dried persimmon slices indicated a decrease in the bioactive compounds and antioxidant capacity. The total phenolic content (TPC) of PVD samples at 70 °C was 87.96% higher than that of the hot air-dried persimmon slices at 65 °C. Interestingly, at 70 °C, the soluble tannin content and TPC of the PVD samples reached the maximum values of 6.09 and 6.97 mg GAE/g, respectively. The findings in the current work indicate that PVD is a promising drying method for persimmon slices as it not only enhances the drying process but also the quality attributes.

14.
J Sci Food Agric ; 102(13): 5965-5973, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35445406

RESUMEN

BACKGROUND: Okra pods contain heat-sensitive substances, such as phenolic compounds and other phytochemicals that can be degraded when okra pods are subjected to heat treatment. The understanding of the impact of high humidity hot air impingement blanching (HHAIB) on the changes in physicochemical properties of polysaccharides and phytochemicals of okra pods is of great importance because over-blanching may result in cell membrane disruption and changes in biologically active compounds under prolonged exposure to the thermal treatment. Therefore, the present study aimed to investigate the effect of HHAIB on the changes in physicochemical properties of pectins and phytochemicals extracted from okra pods. RESULTS: Both the HHAIB time and method of extraction influenced their physicochemical characteristics and biological activity. Pectin fractions subjected to HHAIB were composed of polygalacturonic acid, rhamnogalacturonan, glucomannan, galactan, mannose, arabinose, rhamnose, calcium pectate and arabinogalactan. The contents of total phenolics, total flavonoids and antioxidant activity of extracts mostly increased during HHAIB (i.e. up to 19.0%, 13.2% and 35.3%, respectively). However, HHAIB reduced the chlorophyll-a (up to 55.7%) and lycopene (up to 52.6%) contents of okra pods. CONCLUSION: The acquired knowledge may be useful for better understanding and optimization of technologies based on HHAIB treatment. The HHAIB treated okra can be a promising natural alternative in different applications, including its use as a replacement of some ingredients in food or non-food systems as a result of richness in polysaccharides and polyphenols, as well as high antioxidant properties. © 2022 Society of Chemical Industry.


Asunto(s)
Abelmoschus , Abelmoschus/química , Antioxidantes/química , Pared Celular/metabolismo , Calor , Humedad , Fitoquímicos/análisis , Polisacáridos/química
15.
J Environ Manage ; 309: 114689, 2022 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-35182981

RESUMEN

Understanding the environmental and economic impacts of copper hydrometallurgy throughout the whole life cycle is necessary for sustainable development of the copper industry. In this study, the environmental impacts and economic costs throughout the two major copper hydrometallurgical routes in China, including heap leaching and heap-agitation leaching, are analyzed and compared using the life cycle assessment (LCA) and life cycle cost (LCC) technique. The life cycle inventory compiled from the annual statistics of the Muliashi Copper Mine, and the data regarding energy and materials process are based on the GaBi databases. The environmental impacts are quantified into 12 indicators. The results show that compared with heap leaching route, heap-agitation leaching route reduces 36.8% of abiotic depletion potential (ADP elements), but increases over half of cumulative energy demand (CED), marine aquatic ecotoxicity potential (MAETP) and human toxicity potential (HTP). Furthermore, the stage of electrowinning and agitation leaching contributes the largest environmental impact to heap leaching and heap-agitation leaching route, respectively. This is mainly due to huge consumption of electricity and sulfuric acid. The analysis of economic cost reveals that heap leaching route needs internal cost of $3225/t Cu and external cost of $426/t Cu. Compared with heap leaching route, heap-agitation leaching route increased the internal and external cost by 18.9% and 54.2%, respectively. But the economic return from heap-agitation leaching is double that from heap leaching. Together, these results indicate heap-agitation leaching has a larger environmental impact and higher economic benefit than heap leaching, which is helpful for the government to design ecological compensation policies in the balance between ecological environment and economic development.


Asunto(s)
Cobre , Minería , Animales , China , Costos y Análisis de Costo , Electricidad , Humanos , Estadios del Ciclo de Vida
16.
Carbohydr Polym ; 222: 114980, 2019 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-31320051

RESUMEN

Effects of ripeness (four stages from the lowest to highest degree-I, II, III, and IV) on the physicochemical properties, pectin contents and nanostructure, and drying kinetics of apricots were investigated. The color values (L*, a*, and b*) and total soluble solid content increased during ripening, while the titratable acidity content and hardness decreased. The water-soluble pectin content increased as ripening progressed, but the chelate- and sodium carbonate-soluble pectin contents gradually declined. Atomic force microscopy imaging indicated that the pectin depolymerization occurred during ripening. Fruits at stage III obtained the highest drying rate, and the drying time was reduced by 27.27%, 17.24%, and 7.69% compared to those of stage I, II and IV, respectively. Results showed that the ripeness had significant influence on the drying kinetics, which is related to the modification of physicochemical and pectic properties. The ripeness classification is an essential operation for achieving effective drying process.

17.
Sci Rep ; 8(1): 8255, 2018 May 29.
Artículo en Inglés | MEDLINE | ID: mdl-29844488

RESUMEN

The Precambrian sedimentary strata on the southern margin of the North China Craton are well developed and widely exposed, making the region ideal for the study of depositional processes. However, because of the length of the depositional history and the lack of biogenic criteria, interpretations of the sedimentary environments of the Precambrian strata are often based on the tectonic background, geographical environment, rock type and sedimentary structures, resulting in controversies in the literature. In this study of the Bingmagou Formation in the Ruyang Group on the southern margin of the North China Craton, analysis of petrologic features, palaeocurrents and sedimentary facies is combined with regional correlation of relevant strata and the reconstruction of ancient landforms to explain the depositional environments and environmental transitions. Dominated by marine deposits on the southern margin of the North China Craton, the sedimentary strata of the Ruyang Group unconformably overlie the Archean crystalline basement or Proterozoic Xionger Group. As the lowermost unit of the Ruyang Group, the Bingmagou Formation, which was depositionally controlled by topography and faults and received abundant detrital material, is a highly distinctive set of sedimentary strata and represents an environmental transition from alluvial fan to sandy coast.

18.
Biochim Biophys Acta Mol Basis Dis ; 1864(1): 1-10, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-28986310

RESUMEN

Inflammation has emerged as a critical biological process contributing to hypertensive cardiac remodeling. Effective pharmacological treatments targeting the cardiac inflammatory response, however, are still lacking. Prior studies suggested that the serum- and glucocorticoid-inducible kinase (SGK1) plays a key role in inflammation and cardiac remodeling. Recently, a highly selective SGK1 inhibitor, EMD638683, was developed, though whether EMD638683 can prevent hypertension-induced cardiac fibrosis and the mechanisms by which this inhibitor may alter the disease process remain unknown. Using a murine Angiotension II (Ang II) infusion-induced hypertension model we found that EMD638683 treatment inhibited cardiac fibrosis and remodeling, with significant abatement of cardiac inflammation. EMD638683 was shown to suppress Ang II infusion-induced interleukin (IL)-1ß release, and substantially reduce nucleotide-binding oligomerization domain-like receptor with pyrin domain 3 (NLRP3) expression and caspase-1 activation in cardiac tissues. In vitro experiments revealed that EMD638683 ameliorated Ang II-stimulated IL-1ß secretion in macrophages by blocking NLRP3 inflammasome activation. By reducing IL-1ß production in macrophages, the transformation of fibroblasts to myofibroblasts was inhibited. The effects of EMD638683 on cardiac fibrosis were abolished by supplementation with exogenous IL-1ß. Administration of the NLRP3 inflammasome inhibitor MCC950 indicated that EMD638683 attenuated Ang II-induced cardiac inflammation and fibrosis by inhibiting the NLRP3 inflammasome/IL-1ß secretion axis. These findings indicate that the SGK1 inhibitor EMD638683 can negatively regulate NLRP3 inflammasome activation, and may represent a promising approach to the treatment of hypertensive cardiac damage.


Asunto(s)
Angiotensina II/farmacología , Benzamidas/farmacología , Corazón/efectos de los fármacos , Hidrazinas/farmacología , Inflamasomas/efectos de los fármacos , Miocarditis/prevención & control , Miocardio/patología , Proteína con Dominio Pirina 3 de la Familia NLR/metabolismo , Animales , Cardiotónicos/farmacología , Células Cultivadas , Citoprotección/efectos de los fármacos , Fibrosis/prevención & control , Inflamasomas/metabolismo , Inflamación/prevención & control , Ratones , Ratones Endogámicos C57BL , Miocarditis/patología
19.
Mol Cell Biochem ; 445(1-2): 67-78, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29243066

RESUMEN

Excessive mechanical stretch induces production of proinflammatory mediators in cardiac fibroblasts, which could act as inflammatory supporter cells in heart failure. Accumulation evidence and our previous studies suggest that serum-glucocorticoid-regulated kinase 1 (SGK1) contributes to cardiac remodeling and fibrosis, development of heart failure. However, the role and mechanism of SGK1 in mechanical stretch-induced inflammation of cardiac fibroblasts remain unclear. Here, cardiac fibroblasts isolated from wild-type (WT) and SGK1 knockout (SGK1-/-) mice were stimulated by 18% cyclic stretch, under static condition as the control. The results showed that mechanical stretch increased SGK1 expression and activation in WT cardiac fibroblasts but not its isoform, SGK2 or SGK3 expression. Bio-Plex array revealed hyperstretch could enhance chemokines release in WT cardiac fibroblasts, but SGK1 knockout significantly attenuated chemokines production through blocking activation of nuclear factor-kappa B (NF-κB). Moreover, supernatants from WT cardiac fibroblasts subjected to hyperstretch promoted macrophage migration, enhanced expression of macrophage-derived profibrotic mediators, whereas supernatants from SGK1 deficiency suppressed these effects. Although SGK1 did not directly affect mechanical stretch-induced myofibroblast differentiation, SGK1 activation of cardiac fibroblasts facilitated myofibroblast differentiation through the upregulation of the profibrotic mediators secreted by macrophages. These results suggest that SGK1 may play a critical role in the inflammatory cascade of cardiac fibroblasts triggered by mechanical stretch; SGK1 could be used as a potential target for treatment of cardiac fibrosis and heart failure.


Asunto(s)
Fibroblastos/citología , Proteínas Inmediatas-Precoces/fisiología , Inflamación/fisiopatología , Miocardio/enzimología , Proteínas Serina-Treonina Quinasas/fisiología , Estrés Mecánico , Animales , Células Cultivadas , Quimiocinas/biosíntesis , Medios de Cultivo , Activación Enzimática , Fibroblastos/enzimología , Fibrosis/patología , Insuficiencia Cardíaca/patología , Proteínas Inmediatas-Precoces/genética , Proteínas Inmediatas-Precoces/metabolismo , Mediadores de Inflamación/metabolismo , Macrófagos/citología , Macrófagos/metabolismo , Masculino , Ratones , Ratones Noqueados , Miocardio/citología , Proteínas Serina-Treonina Quinasas/genética , Proteínas Serina-Treonina Quinasas/metabolismo
20.
Waste Manag ; 68: 319-328, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-28662844

RESUMEN

Nitrous oxide (N2O) is a strong greenhouse gas, and its emissions from microbial nitrification (NF) and denitrification (DNF) are a threat to the environment. In the present study, a combined approach consisting of 15N stable isotope and molecular biology (qPCR) was used to determine the contributions of autotrophic nitrification (ANF), heterotrophic nitrification (HNF), and DNF to N2O emissions in laboratory incubations of aged refuse for different ammonia (NH4+-N) loads (200, 400, and 800mg·NH4+-N/kg·aged refuse) and incubation times (2-144h). Experimental results showed that the N2O emissions increased with the increase in applied amount of NH4+-N substrates. Simultaneous nitrification and denitrification (SND) were demonstrated to be present in the incubations of aged refuse. The results of 15N stable isotope labelling experiment indicated that NF (54.60%-68.8%) and DNF (83.38%-85.90%) contributed to majority of N2O emissions in the incubations of 24h and 72h, respectively. The results of functional genes (amoA and nosZ) quantification experiments indicated that the high gene copies of amoA and nosZ were present at 24h and 72h, respectively. The study also demonstrated the utility of a combined stable isotope and molecular biology approach. The approaches not only provide similar inferences about the N2O emissions, but also enable the determination of relative contributions of ANF, HNF, and DNF to N2O emissions. The results of the study are important in providing guidance to artificially optimize the operating conditions for alleviating N2O emissions in aged refuse bioreactors.


Asunto(s)
Reactores Biológicos , Desnitrificación , Amoníaco , Nitrificación , Óxido Nitroso
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...