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1.
Phys Chem Chem Phys ; 26(17): 13182-13197, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38630138

RESUMEN

The gasification of carbon with O2, CO2, and H2O oxidants plays an important role in several energy-based applications. As most of the industrial gasification processes are conducted under mixed-atmosphere conditions, the oxidation of carbon in binary oxidant mixtures becomes crucially important. Using reactive force-field (ReaxFF) potentials, extensive MD simulations were carried out on the oxidation behavior of graphene in mixed O2/H2O and O2/CO2 environments for a range of gas compositions and temperatures. A graphene sheet with a line defect comprising of eight and four-membered rings was used as the starting carbon structure. In addition to enhanced carbon gasification with oxygen additions, MD simulations showed synergistic interactions between different oxidants and their net influence on the overall reactivities. The gasification levels achieved under the binary system were higher than the linear combination of contributions from individual oxidants. The addition of ∼40% O2 in the binary mix was identified as the region with the highest reactivity during the initial stages of gasification. The oxidation reactions with oxygen were found to start instantaneously in the presence of H2O or CO2 instead of the usual initial delay. A very fast reaction kinetics was also observed in the initial stages in the presence of oxygen. Our results show that the gasification reactions under H2O and CO2 started at lower temperatures than O2 thereby creating a partially oxidized structure. Due to the presence of a large number of activation sites, very high rates of gasification were achieved with oxygen. These findings could help identify optimal oxidant compositions towards maximizing carbon gasification and minimizing CO2 emissions.

2.
Phys Chem Chem Phys ; 23(34): 19071-19082, 2021 Sep 14.
Artículo en Inglés | MEDLINE | ID: mdl-34612444

RESUMEN

More attention needs to be drawn to the high application value of the gasification reaction between carbonaceous materials and water in industry. In this study, density functional theory is used to investigate the adsorption and reaction mechanism of water molecules on graphene surfaces with various kinds of defects. The desorption mechanism of the reaction product is also analyzed. The optimal and stable physical adsorption configuration of water molecules on the pristine graphene and various defects graphene surface has been determined. Chemisorption configurations of a single water molecule and double water molecules on the graphene surface with single vacancy defects are discussed and used as reaction precursors to explore the reaction path of water molecules in the process of desorbing hydrogen at active sites. The whole process of the reaction is largely exothermic and the thermodynamic advantages of double water molecules participating in the reaction are determined. The two reaction mechanisms of two-steps or co-adsorption and desorption of double water molecules are compared, and the lowest energy barrier advantage of the latter is determined.

3.
J Ultrasound Med ; 40(12): 2655-2663, 2021 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-33615538

RESUMEN

OBJECTIVES: Skeletal muscle dysfunction is one of the most common comorbidities in chronic obstructive pulmonary disease (COPD). The occurrence of respiratory failure in COPD is common and leads to the patient's death. The diaphragm is the most important muscle in the respiratory system and plays a key role in the onset of respiratory failure. This study explores the feasibility of ultrasound shear wave elastography (SWE) to measure diaphragmatic stiffness and evaluates its changes in COPD patients. METHODS: In total, 77 participants (43 patients with stable COPD and 34 healthy controls) were enrolled. All subjects underwent complete diaphragmatic ultrasound SWE measurements and pulmonary function tests. The diaphragmatic stiffness was indicated via diaphragmatic shear wave velocity (SWV) at functional residual capacity (FRC). A trained operator performed the ultrasound SWE examinations of the first 15 healthy controls thrice to assess the reliability of diaphragmatic SWE. RESULTS: A good to excellent reliability was found in diaphragmatic SWV at FRC (ICC = 0.93, 95%CI 0.82-0.98). As compared to the control group, the diaphragmatic SWV at FRC was considerably high in the COPD group (median 2.5 m/s versus 2.1 m/s, P = .008). Diaphragmatic SWV at FRC was linked to forced expiratory volume in one second (r = -0.30, P = .009), forced vital capacity (r = -0.33, P = .003), modified Medical Research Council score (r = 0.30, P = .001), and COPD assessment test score (r = 0.48, P < .001). CONCLUSIONS: Ultrasound SWE may be employed as an effective tool for quantitative evaluation of diaphragm stiffness and can help in personalized management of COPD, such as treatment guidance and follow-up monitoring.


Asunto(s)
Diagnóstico por Imagen de Elasticidad , Enfermedad Pulmonar Obstructiva Crónica , Diafragma/diagnóstico por imagen , Humanos , Proyectos Piloto , Enfermedad Pulmonar Obstructiva Crónica/complicaciones , Enfermedad Pulmonar Obstructiva Crónica/diagnóstico por imagen , Reproducibilidad de los Resultados
4.
Molecules ; 21(10)2016 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-27706063

RESUMEN

Koumine is a kind of alkaloid extracted from Gelsemium elegans (G. elegans). Benth, which has shown promise as an anti-tumor, anxiolytic, and analgesic agent. In our present study, the effect of koumine on lipopolysaccharide (LPS)-mediated RAW 264.7 cell apoptosis was evaluated. MTT assays showed that koumine obviously increased cell viability in LPS-mediated RAW 264.7 macrophages. Preincubation with koumine ameliorated LPS-medicated apoptosis by decreasing reactive oxygen species (ROS) production, which resulted in a significant decrease in the levels of nitric oxide (NO) and inducible nitric oxide synthase (iNOS). In addition, koumine-pretreated RAW 264.7 macrophages exhibited reduction of LPS-induced levels of TNF-α, IL-1ß, and IL-6 mRNA. Furthermore, pretreatment with koumine suppressed LPS-mediated p53 activation, loss of mitochondrial membrane potential, caspase-3 activation, decrease of Bcl-2 expression, and elevation of Bax and caspase-3 expressions, suggesting that koumine might act directly on RAW 264.7 cells to inhibit LPS-induced apoptosis. It seems as though the mechanism that koumine possesses is the anti-apoptotic effect mediated by suppressing production of ROS, activation of p53, and mitochondrial apoptotic pathways in RAW 264 cells. Koumine could potentially serve as a protective effect against LPS-induced apoptosis.


Asunto(s)
Apoptosis/efectos de los fármacos , Alcaloides Indólicos/farmacología , Lipopolisacáridos/toxicidad , Mitocondrias/metabolismo , Transducción de Señal/efectos de los fármacos , Animales , Regulación de la Expresión Génica/efectos de los fármacos , Ratones , Monocinas/biosíntesis , Óxido Nítrico/biosíntesis , Proteínas Proto-Oncogénicas c-bcl-2/biosíntesis , Células RAW 264.7
5.
Phytother Res ; 29(5): 770-6, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25712886

RESUMEN

Xylaria nigripes (XN) is a medicinal fungus with a high-economic value. The aim of this study was to explore the hypoglycemic effects and mechanisms of the XN aqueous extract in steroid-induced insulin-resistant (SIIR) rats. Significant hypoglycemic effects were observed 60 min after administration of XN aqueous extract. In normal Wistar, hypoglycemic effects were 21% (the plasma glucose level decreased from 128.6 ± 12.5 to 100.9 ± 10.7 mg/dL). In SIIR, hypoglycemic effects were 26% (the plasma glucose level decreased from 177.6 ± 12.5 to 133.3 ± 29.7 mg/dL) rats refer to their baseline. The signaling proteins for insulin-receptor substrate-1 and glucose transporter-4 increased 0.51-fold and 1.12-fold, respectively, as determined by Western blotting; the increase in the proteins was 13% and 9%, respectively, as determined by immunohistochemistry. The serotonin antagonist, α-p-chlorophenylalanine, effectively blocked the hypoglycemic effects and increased the signaling protein levels. After XN administration, none of the animals showed significant changes in plasma-free fatty acids in 60 min. In summary, the XN extract may have hypoglycemic effects in normal Wistar and SIIR rats that may have a serotonin-related hypoglycemic effect and enhance insulin sensitivity in the SIIR rats.


Asunto(s)
Productos Biológicos/farmacología , Hipoglucemiantes/farmacología , Resistencia a la Insulina , Serotonina/metabolismo , Xylariales/química , Animales , Glucemia/efectos de los fármacos , Ácidos Grasos no Esterificados/sangre , Fenclonina/farmacología , Transportador de Glucosa de Tipo 4/metabolismo , Insulina/sangre , Proteínas Sustrato del Receptor de Insulina/metabolismo , Ratas , Ratas Wistar , Antagonistas de la Serotonina/farmacología
6.
Dig Dis Sci ; 58(6): 1581-9, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23314859

RESUMEN

BACKGROUND: The first identified lysine-specific demethylase, LSD1, plays an important role in the metastatic progression of several types of cancer. AIMS: The aim of this study was to investigate LSD1, E-cadherin, and N-cadherin expression in colon cancer specimens and their clinical significance. METHODS: The expression of LSD1, E-cadherin, and N-cadherin in colon cancer specimens was determined by immunohistochemistry, and the relationship between the expression of the respective molecules and clinicopathological characteristics was analyzed. RESULTS: The positive expression rates of LSD1, E-cadherin, and N-cadherin in colon cancer specimens were 66.7 % (72/108), 85.2 % (92/108), and 41.7 % (45/108), respectively. LSD1 was significantly more highly expressed in colon cancer specimens classified as high TNM stage lesions and with distant metastasis (P < 0.05). Further analysis demonstrated that LSD1 expression was positively correlated with lymph node and distant metastases (P < 0.05). However, E-cadherin expression was significantly downregulated in colon cancer specimens classified as high TNM stage lesions and with distant metastasis (P < 0.05), whereas the expression of N-cadherin did not differ significantly according to clinical and pathological characteristics (P > 0.05). Correlation analysis revealed that LSD1 expression was negatively correlated with E-cadherin expression (r s = -0.318, P = 0.001), but not evidently correlated with N-cadherin expression (r s = 0.182, P = 0.06). Colon cancer specimens with positive LSD1 expression and negative E-cadherin expression were correlated with significantly lower overall survival. CONCLUSIONS: LSD1 showed a significantly higher expression, in contrast to the significantly lower expression of E-cadherin, in colon cancer specimens classified as high TNM stage lesions and with distant metastasis. Positive expression of LSD1 and negative expression of E-cadherin may be predictors of a worse colon cancer prognosis.


Asunto(s)
Antígenos CD/metabolismo , Biomarcadores de Tumor/metabolismo , Cadherinas/metabolismo , Neoplasias del Colon/metabolismo , Histona Demetilasas/metabolismo , Adulto , Anciano , Estudios de Casos y Controles , Neoplasias del Colon/mortalidad , Neoplasias del Colon/patología , Regulación hacia Abajo , Femenino , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Metástasis Linfática , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Tasa de Supervivencia , Regulación hacia Arriba
7.
J Mol Model ; 29(4): 116, 2023 Mar 27.
Artículo en Inglés | MEDLINE | ID: mdl-36973451

RESUMEN

CONTEXT: A steam-rich environment is a more promising application scenario for future coal-fired processes, while active sites are the key factor that determines the reactivity of carbonaceous fuels. The steam gasification process of carbon surfaces with different numbers of active sites (0, 12, 24, 36) was simulated using reactive molecular dynamics in the present study. The temperature for the decomposition of H2O and the gasification of carbon is determined using temperature-increasing simulation. The decomposition of H2O was influenced by two driving forces, thermodynamics and active sites on the carbon surface, which dominated the different reaction stages, leading to the observed segmentation phenomenon of the H2 production rate. The existence and number of initial active sites have a positive correlation with both two stages of the reaction, greatly reducing the activation energy. Residual OH groups play an important role in the gasification of carbon surfaces. The supply of OH groups through the cleavage of OH bonds in H2O is the rate-limiting step in the carbon gasification reaction. The adsorption preference at carbon defect sites was calculated using density functional theory. Two stable configurations (ether & semiquinone groups) can be formed with O atoms adsorbed on the carbon surface according to the number of active sites. This study will provide further insights into the tuning of active sites for advanced carbonaceous fuels or materials. METHODS: The large-scale atomic/molecule massively parallel simulator (LAMMPS) code combined with the reaction force-field method was used to carry out the ReaxFF molecular dynamics simulation, where the ReaxFF potentials were taken from Castro-Marcano, Weismiller and William. The initial configuration was built using Packmol, and the visualization of the calculation results was realized through Visual Molecular Dynamics (VMD). The timestep was set to 0.1 fs to detect the oxidation process with high precision. PWscf code in QUANTUM ESPRESSO (QE) package, was used to evaluate the relative stability of different possible intermediate configurations and the thermodynamic stability of gasification reactions. The projector augmented wave (PAW) and the generalized gradient approximation of Perdew-Burke-Ernzerhof (PBE-GGA) were adopted. Kinetic energy cutoffs of 50 Ry and 600 Ry, and a uniform mesh of 4 × 4 × 1 k-points were used.

8.
Nanomaterials (Basel) ; 13(14)2023 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-37513062

RESUMEN

The hydrogen-based direct reduction of iron ores is a disruptive routine used to mitigate the large amount of CO2 emissions produced by the steel industry. The reduction of iron oxides by H2 involves a variety of physicochemical phenomena from macroscopic to atomistic scales. Particularly at the atomistic scale, the underlying mechanisms of the interaction of hydrogen and iron oxides is not yet fully understood. In this study, density functional theory (DFT) was employed to investigate the adsorption behavior of hydrogen atoms and H2 on different crystal FeO surfaces to gain a fundamental understanding of the associated interfacial adsorption mechanisms. It was found that H2 molecules tend to be physically adsorbed on the top site of Fe atoms, while Fe atoms on the FeO surface act as active sites to catalyze H2 dissociation. The dissociated H atoms were found to prefer to be chemically bonded with surface O atoms. These results provide a new insight into the catalytic effect of the studied FeO surfaces, by showing that both Fe (catalytic site) and O (binding site) atoms contribute to the interaction between H2 and FeO surfaces.

9.
J Mol Model ; 29(12): 372, 2023 Nov 13.
Artículo en Inglés | MEDLINE | ID: mdl-37955718

RESUMEN

CONTEXT: An atomistic coke carbon model was constructed to simulate the structural evolution in the gasification and stretching process. The coke model was placed in a box with different CO2/H2O content to investigate the evolution of the atomistic structure of coke during the gasification. It was found that different atmospheric concentrations had different effects on the structure and reaction sites of the coke model. The CO2 molecules tended to dissolve on the surface of coke and disrupt its surface structure, while H2O molecules were more likely to enter the coke model to disrupt the internal structure. For tensile simulation, it was found that CO2 and H2O had different effects on the tensile resistance of the coke model. Controlling the composition content of the reaction gas can effectively influence the tensile strength of the coke model. By revealing the behavior of coke model at the micro scale, it provides a theoretical basis for the industrial coke application process. METHODS: Large-scale Atomic/Molecular Massively Parallel Simulator (LAMMPS) was used to conduct the molecular dynamics using the reactive force field (ReaxFF). The atomistic model of coke carbon was constructed using the well-known annealing and quenching method, and its composition is determined according to the element analysis of industrial coke. The structural evolution in the gasification with CO2/H2O and the stretching process were analyzed in detail. Molecular dynamics simulations with reactive force field (ReaxFF-MD) were used to simulate the coke dissolution reaction under CO2/H2O atmosphere and the coke stretching process. The atmosphere ratio was modified to investigate the changes in coke structure under different atmosphere conditions. The Packmol software was used to place gas and coke models into the same box. During the reaction process, the Ovito software was used to perform corresponding visualization analysis on the changes in the atomic structure of coke.

10.
ACS Omega ; 8(40): 37043-37053, 2023 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-37841130

RESUMEN

In this study, ReaxFF-MD was used to construct a large-molecule model of coke containing 3000 atoms, and the sp2 bond content of the model was controlled by changing the heating and cooling rates. The increase of the sp2 bond content led to a significant difference in the reactivity of coke. The presence of the sp2 bond caused the carbon atoms inside the coke to change into a circular structure, making it more difficult for the gaseous atoms to adsorb on the surface of the coke. It significantly reduced the gasification reaction rate of coke in the CO2 and H2O atmospheres. In the tensile simulation experiment, it was found that the stretching process of coke was mainly divided into three stages: an elastic stretching stage, a plastic stretching stage, and a model fracture stage. During the stretching process, the carbon ring structure would undergo a C-C bond fracture while generating carbon chains to resist stress. The results indicated that the presence of sp2 bonds can effectively reduce the phenomenon of excessive local stress on coke to improve its tensile resistance. The method developed in this paper may provide further ideas and platforms for the research on coke performance.

11.
Bioresour Technol ; 368: 128338, 2023 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-36403908

RESUMEN

The lignin hydrothermal processing is an important option but a full understanding of the role played by the water molecules in the depolymerization of lignin is still lacking. In order to clarify the role of the water molecules in the depolymerization of lignin, the evolution of chemical bonds, microstructural changes, and possible mechanisms of product generation were compared during the pyrolysis process under vacuum and water conditions using Reactive Molecular Dynamics Simulation. Compared with vacuum conditions, the role of water changes with temperature, identifying three stages: promotion (1200-1800 K)-inhibition (2100-2400 K)-promotion (2700-3000 K). Also compared with vacuum conditions, hydrothermal processing can promote the cleavage of the ether bonds while inhibiting the destruction of carbocycles. Water molecules promote the depolymerization of lignin into more C4-molecules, thereby generating more combustible gas resources. Based on the research results, the pyrolysis conditions of lignin can be flexibly controlled to obtain solids, liquids or gases.


Asunto(s)
Simulación de Dinámica Molecular , Pirólisis , Lignina , Agua , Gases
12.
Nanoscale ; 15(25): 10740-10748, 2023 Jun 30.
Artículo en Inglés | MEDLINE | ID: mdl-37323016

RESUMEN

Recent experiments have revealed multiple borophene phases of distinct lattice structures, suggesting that the unit cells of ν1/6 and ν1/5 boron sheets, namely α and ß chains, serve as building blocks to assemble into novel borophene phases. Motivated by these experiments, we present a theoretical study of electron transport along two-terminal quasiperiodic borophene nanoribbons (BNRs), with the arrangement of the α and ß chains following the generalized Fibonacci sequence. Our results indicate that the energy spectrum of these quasiperiodic BNRs is multifractal and characterized by numerous transmission peaks. In contrast to the Fibonacci model that all the electronic states should be critical, both delocalized and critical states appear in the quasiperiodic BNRs, where the averaged resistance saturates at the inverse of one conductance quantum for the delocalized states in the large length limit and contrarily exhibits a power-law dependence on the nanoribbon length for the critical states. Besides, the self-similarity is observed from the transmission spectrum, where the conductance curves overlap at different energy regions of two quasiperiodic BNRs of different Fibonacci indices and the resistance curves are analogous to each other at different energy scales of a single quasiperiodic BNR. These results complement previous studies on quasiperiodic systems where the multifractal energy spectrum and the self-similarity are observed by generating quasiperiodic potential energies, suggesting that borophene may provide an intriguing platform for understanding the structure-property relationships and exploring the physical properties of quasiperiodic systems.


Asunto(s)
Nanotubos de Carbono , Transporte de Electrón , Boro , Electrónica
13.
Int J Med Mushrooms ; 25(9): 43-61, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37824405

RESUMEN

Phellinus linteus is a famous medicinal mushroom which exhibits various biological activities. This study aimed to investigate the effects of solid-state fermentation by Ph. linteus on the yield of bioactive compounds and antioxidant activities of beans. Four bean substrates were prepared and inoculated with inoculum of three strains of Ph. linteus, respectively. During the cultivation, the harvested samples were dried, grounded, extracted, and determined the contents of bioactive compounds and antioxidant activities. The results indicated that the mung bean fermented by Ph. linteus 04 had the highest polysaccharide content (98.8 mg/g). The highest total phenolic and flavonoid contents were in fermented soybeans by Ph. linteus 03 (15.03 mg gallic acid equivalents/g and 63.24 mg rutin equivalents/g, respectively). The 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities of hot water extracts were higher than those of ethanolic extracts for fermented beans by three Ph. linteus strains. However, the superoxide anion radical scavenging ability of ethanolic extracts was higher than those of hot water extracts in the fermented beans of the three strains. The ferrous ion (Fe2+)-chelating abilities of hot water extracts were higher than those of ethanolic extracts in fermented beans by Ph. linteus 03 and 04. In contrast, ethanolic extracts were higher than hot water extracts in fermented beans by Ph. linteus 06. Overall, these results indicate that the fermentation by Ph. linteus strains increased the bioactive compounds and antioxidant activities of four beans.


Asunto(s)
Antioxidantes , Basidiomycota , Antioxidantes/química , Fermentación , Basidiomycota/metabolismo , Agua
14.
J Mol Model ; 28(5): 118, 2022 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-35412080

RESUMEN

Much research has been done on reactions of a single CO2 molecule with a graphene surface. In this paper, density functional theory calculations are used to investigate the adsorption and reaction of double CO2 on the surface of single vacancy (SV) and divacancy (DV) defect graphene. The study found that due to the mutual repulsion between CO2 and the size of the SV defect, it is difficult for two CO2 molecular to be adsorbed directly above the SV defect at the same time. Regardless of SV or DV, the adsorption of the first CO2 in the defect center will have a beneficial effect on the adsorption of the second CO2. In addition, the transition state calculation of the CO2 reaction on the DV plane was carried out, and the adsorption behavior was analyzed and studied. This in-depth study is helpful to the understanding of the reaction behavior of CO2 on graphene, and further exploration in the direction of the effective application of graphene to the reaction and adsorption of CO2. Our work explores the adsorption behavior of CO2 on graphene surfaces, the physical and chemical adsorption of double CO2 at the defect was studied and analyzed.

15.
Int J Med Mushrooms ; 24(3): 77-90, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35467808

RESUMEN

This study aimed 1) to screen a high hispidin production strain from 12 strains of genus Phellinus and 2) to evaluate the effects of liquid inoculum conditions and grain medium on this strain's hispidin production levels after solid-state fermentation. The results showed that Ph. linteus 04 led to the highest hispidin production; this strain was then selected to elucidate the optimal liquid inoculum conditions and grain medium for hispidin production. Various liquid inoculum conditions were evaluated, and the highest hispidin yield, specific productivity of hispidin, and total content of hispidin were found to be optimal at 1 week of liquid inoculum culture time, cultured with potato dextrose broth, and using a 10% inoculum rate, with each condition resulting in 0.350, 0.325, and 0.328 mg/g dry weight of mycelium, 0.352, 0.251, and 0.249 µg/mg of specific productivity per week, and 57.90, 60.23, and 61.77 mg/kg dry weight of brown rice medium, respectively. These liquid inoculum conditions were then used to determine the appropriate grain medium for hispidin production. The highest hispidin yield and total content of hispidin were observed in pearl barley (1.107 mg/g dry weight of mycelium and 199.76 mg/kg dry weight of pearl barley), which led to results that were 4.73-fold and 5.35-fold higher than those of the control (brown rice medium). Overall, this study shows that Ph. linteus hispidin production can be enhanced by solid-state fermentation using optimal liquid inoculum conditions and the appropriate grain medium.


Asunto(s)
Basidiomycota , Oryza , Basidiomycota/química , Medios de Cultivo/química , Grano Comestible , Fermentación , Phellinus , Pironas/química
16.
Materials (Basel) ; 15(23)2022 Nov 23.
Artículo en Inglés | MEDLINE | ID: mdl-36499813

RESUMEN

With the aim to find the best simulation routine to accurately predict the ground-state structures and properties of iron oxides (hematite, magnetite, and wustite) using density functional theory (DFT) with Hubbard-U correction, a significant amount of DFT calculations were conducted to investigate the influence of various simulation parameters (energy cutoff, K-point, U value, magnetization setting, smearing value, etc.) and pseudopotentials on the structures and properties of iron oxides. With optimized simulation parameters, the obtained equation of state, lattice constant, bulk moduli, and band gap is much closer to the experimental values compared with previous studies. Due to the strong coupling between the 2p orbital of O and the 3d orbital of Fe, it was found that Hubbard-U correction obviously improved the results for all three kinds of iron oxides including magnetite which has not yet been tested with U correction before, but the U value should be different for different oxides (3 ev, 4 ev, 4 ev for hematite, magnetite, and wustite, respectively). Two kinds of spin magnetism settings for FeO are considered, which should be chosen according to different calculation purposes. The detailed relationship between the parameter settings and the atomic structures and properties were analyzed, and the general principles for future DFT calculation of iron oxides were provided.

17.
Biology (Basel) ; 11(2)2022 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-35205200

RESUMEN

Oyster shell waste has led to many problems, including displeasing odors, pollution of the seaside, and harm to the environment. Using calcined oyster shells as a natural preservative might solve the problem of oyster shell waste. We studied the use of calcined oyster shell powder (COSP) as a natural preservative for improving shrimp shelf-life over 12 days under refrigerated conditions. As compared with the control, COSP treatment effectively retarded pH change, reduced the formation of total volatile basic nitrogen, and inhibited bacterial growth during refrigerated storage. In addition, shrimp muscle lipid oxidation measured by peroxide value (PV) and thiobarbituric acid (TBA) was decreased during storage. The quality was preserved up to 12 days with 2.0-4.0% COSP treatment as compared with only 6 days for un-treated shrimp. The development of preservatives for aquatic products is expected to delay growth of and spoilage by microorganisms in the refrigerated state, thus providing more barrier protection for aquatic food safety.

18.
J Pept Sci ; 17(5): 383-6, 2011 May.
Artículo en Inglés | MEDLINE | ID: mdl-21412957

RESUMEN

Calcitonin gene-related peptide (CGRP), a potent dilator of cerebral and dural vasculature, is known to be elevated in plasma and cerebral spinal fluid during migraine attacks. Selective blockade of the CGRP receptor offers the promise of controlling migraine headache more effectively and without the side-effects associated with the use of triptans. Our efforts to develop a novel, peptide-based CGRP antagonist focused on the C-terminal portion of the peptide which is known to bind the receptor but lack agonist properties. Extensive SAR studies of the C-terminal CGRP (27-37) region identified a novel cyclic structure: Bz-Val-Tyr-cyclo[Cys-Thr-Asp-Val-Gly-Pro-Phe-Cys]-Phe-NH(2) (23) with a kb value of 0.126 nM against the cloned human CGRP receptor. Additional SAR studies directed at enhancement of potency and improvement of physicochemical properties yielded a series of analogs with kb values in the 0.05-0.10 nM range.


Asunto(s)
Antagonistas del Receptor Peptídico Relacionado con el Gen de la Calcitonina , Péptidos/química , Péptidos/farmacología , Humanos
19.
Int J Med Mushrooms ; 13(2): 193-9, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-22135896

RESUMEN

Cultivation of the culinary-medicinal Lung Oyster mushroom, Pleurotus pulmonarius, on the stalks of three grass plants, i.e., Panicum repens, Pennisetum purpureum, and Zea mays were investigated. The effects of various combinatorial substrates on mushroom mycelial growth and yield calculated as biological efficiency (BE) were determined. Among 9 experimental substrates, the most suitable substrate for mycelial growth was 45ZMS:45S, followed by 45PRS:45S; their mycelial growth rates were obviously quicker than that of the control substrate. The BEs of all the experimental substrates respectively containing P. repens stalk, P. purpureum stalk and Z. mays stalk were higher than that of the control (39.55%) during the 2.5 months of cultivation period. The best substrate in terms of BE was 60ZMS:30S (58.33%), followed by 45PRS:45S (57.16%), 45ZMS:45S (49.86%), and 30ZMS:60S (47.20%). Based on the BE of the tested substrates, Z mays stalk appeared to be the best alternative material for the production of P. pulmonarius.


Asunto(s)
Panicum/microbiología , Pennisetum/microbiología , Pleurotus/crecimiento & desarrollo , Zea mays/microbiología , Agricultura , Micelio/crecimiento & desarrollo , Madera/microbiología
20.
Medicine (Baltimore) ; 100(42): e27510, 2021 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-34678884

RESUMEN

BACKGROUND: Infliximab (IFX) and adalimumab (ADA) refer to the classic drugs to treat moderate-severe inflammatory bowel disease (IBD), which have been proven to be effective to control IBD. However, the side effects exerted by IFX and ADA should be monitored in therapies, especially the paradoxical reaction of the skin system (e.g., psoriasis). Psoriasis is recognized as the most common skin lesion, capable of significantly affecting the quality of patients' life. METHODS: This study searched literatures published in English language with the qualifications on PubMed, Embase, Web of Science, Google, and Geenmedical databases. Over 2 co-authors assessed the quality of the articles and extracted the data independently. The data acquired were statistically analyzed with the statistical software of Revman and Stata. RESULTS: The ADA Group achieved a higher incidence of psoriasis (odds ratio [OR] = 0.658, 95% confidence interval [CI] [0.471-0.919]); Females achieved a higher incidence of psoriasis than males (OR = 1.941, 95%CI [1.326-2.843], P < .05); Smoking up-regulated the incidence of psoriasis (OR = 1.679, 95%CI [1.237-2.279], P < .05); The interval of medication was over 1 year, and the interval of medication applying IFX was longer than that of the ADA Group; most cases could be relieved by using local hormone, phototherapy, or systemic hormone therapy under the strategy of biological agents. CONCLUSIONS: The frequency of reported in IBD exceeds those of other autoimmune diseases, and the ADA treatment for IBD is safer than IFX. Psoriasis is more common in females than in males. Smoking refers to one of risk factors of psoriasis.


Asunto(s)
Fármacos Gastrointestinales/uso terapéutico , Enfermedades Inflamatorias del Intestino/tratamiento farmacológico , Enfermedades Inflamatorias del Intestino/epidemiología , Psoriasis/epidemiología , Fumadores/estadística & datos numéricos , Inhibidores del Factor de Necrosis Tumoral/uso terapéutico , Adalimumab/uso terapéutico , Fármacos Gastrointestinales/administración & dosificación , Fármacos Gastrointestinales/efectos adversos , Humanos , Incidencia , Infliximab/uso terapéutico , Psoriasis/tratamiento farmacológico , Factores de Riesgo , Distribución por Sexo , Inhibidores del Factor de Necrosis Tumoral/administración & dosificación , Inhibidores del Factor de Necrosis Tumoral/efectos adversos
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