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1.
Small ; : e2401307, 2024 May 27.
Artigo em Inglês | MEDLINE | ID: mdl-38801308

RESUMO

With the guidance of density functional theory (DFT), a high-performance hafnium (Hf) cathode for an air/water vapor plasma torch is designed and the concepts and principles for high performance are elucidated. A quasi-nanocrystalline hexagonal close-packed (HCP) Hf-La2O3 cathode based on these design principles is successfully fabricated via a powder metallurgy route. Under identical voltage and temperature conditions, the thermal emission current density of this quasi-nanocrystalline Hf-La2O3 cathode is ≈20 times greater than that of conventional Hf cathodes. Additionally, its cathodic lifespan is significantly extended. Quasi-nanocrystalline Hf-La2O3 products are manufactured into cathode devices with standard dimensions. This fabrication process is straightforward, requires minimal doped oxides, and is cost-effective. Consequently, the approach offers substantial performance enhancements over traditional Hf melting methods without incurring significantly additional costs.

2.
Zhongguo Zhong Yao Za Zhi ; 49(10): 2783-2797, 2024 May.
Artigo em Chinês | MEDLINE | ID: mdl-38812179

RESUMO

Dihuang Baoyuan Granules is a prescription endorsed by HU Tianbao, a renowned and elderly Chinese medicine practitioner from Beijing, and has demonstrated definite clinical efficacy. The composition of this prescription is intricate as it includes 7 distinct herbal medicines. This study aims to analyze the chemical composition of Dihuang Baoyuan Granules, evaluate its efficacy in the treatment of diabetes and analyze the distribution of the drug components in the plasma, liver, and kidney after administration. The findings will serve as a reference for future research on pharmacodynamic substances of this prescription. UHPLC-LTQ-Orbitrap MS was employed to analyze the main chemical components of Dihuang Baoyuan Granules. A Waters ACQUITY Premier HSS T3 column(2.1 mm×100 mm, 1.8 µm) was used for chromatographic separation with 0.1% formic acid(A)-acetonitrile(B) as the mobile phases in a gradient elution at a flow rate of 0.3 mL·min~(-1). Electrospray ionization(ESI) source was used to acquire data in positive and negative ion modes. Furthermore, a rat model of diabetes mellitus was established by feeding with a high-sugar high-fat diet, and injection with streptozocin at a dose of 35 mg·kg~(-1), and the modeled rats were then administrated with Dihuang Baoyuan Granules. The fasting blood glucose, hemoglobin A1c, and other relevant indicators were measured, and the substances present in the plasma, liver, and kidney were identified. By reference to quasi-molecular ions, MS/MS fragment ions, MS spectra of reference substances, and compound information in available reports, 191 components were identified in Dihuang Baoyuan Granules, including 29 alkaloids, 24 flavonoids, 22 organic acids, 16 amino acids, 12 terpenes, 11 steroid saponins, 9 sugars, 8 phenylethanoid glycosides, 8 nucleosides, 2 phenylpropanoids, and 49 others compounds. Eighty-three chemical components were identified in rat plasma, 109 in the liver, and 98 in the kidney. Component identification and characterization of Dihuang Baoyuan Granules in vitro and in vivo provide efficacy information and guidance for the basic research on the pharmacodynamic substances and further clinical application of this prescription.


Assuntos
Medicamentos de Ervas Chinesas , Ratos Sprague-Dawley , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacocinética , Cromatografia Líquida de Alta Pressão/métodos , Animais , Ratos , Masculino , Humanos , Fígado/efeitos dos fármacos , Fígado/química , Fígado/metabolismo , Espectrometria de Massas/métodos , Rim/efeitos dos fármacos , Rim/química , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus/tratamento farmacológico
3.
Front Nutr ; 11: 1385159, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38628273

RESUMO

Introduction: Functional dyspepsia (FD), also known as non-ulcerative dyspepsia, is a common digestive system disorder. Methods: In this study, an FD model was established using hunger and satiety disorders combined with an intraperitoneal injection of L-arginine. Indices used to evaluate the efficacy of hawthorn in FD mice include small intestinal propulsion rate, gastric residual rate, general condition, food intake, amount of drinking water, gastric histopathological examination, and serum nitric oxide (NO) and gastrin levels. Based on the intestinal flora and their metabolites, short-chain fatty acids (SCFAs), the mechanism of action of Crataegi Fructus (hawthorn) on FD was studied. The fecal microbiota transplantation test was used to verify whether hawthorn altered the structure of the intestinal flora. Results: The results showed that hawthorn improved FD by significantly reducing the gastric residual rate, increasing the intestinal propulsion rate, the intake of food and drinking water, and the levels of gastrointestinal hormones. Simultaneously, hawthorn elevated substance P and 5-hydroxytryptamine expression in the duodenum, reduced serum NO levels, and increased vasoactive intestinal peptide expression in the duodenum. Notably, hawthorn increased the abundance of beneficial bacteria and SCFA-producing bacteria in the intestines of FD mice, decreased the abundance of conditional pathogenic bacteria, and significantly increased the SCFA content in feces. Discussion: The mechanism by which hawthorn improves FD may be related to the regulation of intestinal flora structure and the production of SCFAs.

4.
Materials (Basel) ; 16(13)2023 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-37444926

RESUMO

Tungsten (W), as a promising plasma-facing material for fusion nuclear reactors, exhibits ductility reduction. Introducing high-density coherent nano-dispersoids into the W matrix is a highly efficient strategy to break the tradeoff of the strength-ductility performance. In this work, we performed helium (He) ion irradiation on coherent oxide-dispersoids strengthened (ODS) W to investigate the effect of coherent nanoparticle interfaces on the behavior of He bubbles. The results show that the diameter and density of He bubbles in ODS W are close to that in W at low dose of He ion irradiation. The radiation-induced hardening increment of ODS W, being 25% lower than that of pure W, suggests the involvement of the coherent interface in weakening He ion irradiation-induced hardening and emphasizes the potential of coherent nano-dispersoids in enhancing the radiation resistance of W-based materials.

5.
Materials (Basel) ; 16(11)2023 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-37297056

RESUMO

The AISI 316L austenitic stainless steel fabricated by selective laser melting (SLM) is considered to have great prospects for applications in nuclear systems. This study investigated the He-irradiation response of SLM 316L, and several possible reasons for the improved He-irradiation resistance of SLM 316L were systematically revealed and evaluated by using TEM and related techniques. The results show that the effects of unique sub-grain boundaries have primary contributions to the decreased bubble diameter in SLM 316L compared to that in the conventional 316L counterpart, while the effects of oxide particles on bubble growth are not the dominant factor in this study. Moreover, the He densities inside the bubbles were carefully measured using electron energy loss spectroscopy (EELS). The mechanism of stress-dominated He densities in bubbles was validated, and the corresponding reasons for the decrease in bubble diameter were freshly proposed in SLM 316L. These insights help to shed light on the evolution of He bubbles and contribute to the ongoing development of the steels fabricated by SLM for advanced nuclear applications.

6.
Food Funct ; 11(9): 8354-8368, 2020 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-32930693

RESUMO

Recently, we have proposed that quinoa yoghurt (QY) has the anti-diabetic properties based on an in vitro study. Here, its antidiabetic activity was further validated by investigating its hypoglycemic and hypolipidemic influence in high fat diet/streptozotocin-induced type 2 diabetes mellitus (T2DM) mice. The results showed that QY increased the body weights of and reduced the fasting blood glucose levels in T2DM mice. QY significantly (p < 0.05) reduced the serum levels of total cholesterol, triglyceride and LDL-C, while it increased the HDL-C level. In addition, the hepatic glycogen content, and superoxide dismutase, catalase, and glutathione peroxidase activities were significantly (p < 0.05) increased, while lipid peroxidation was remarkably reduced. Sprouted QY had the highest influence on serum oxidation when compared with non-germinated QY. The level of pro-inflammatory cytokines (TNF-α, IL-6 and IL-1ß) were significantly (p < 0.05) decreased, while the level of anti-inflammatory cytokine IL-10 was increased. Histopathological studies showed that QY protected the tissue structure of the liver of T2DM mice. Immunohistochemistry showed that QY increased AKT-2 and AMPK-α2 expressions, while it suppressed p85. The qRT-PCR analysis indicated that QY exerted its hypoglycemic and anti-hyperlipidemic effects through the AKT/AMPK/PI3K signaling pathway. Germination significantly (p < 0.05) influenced the glucose and lipid homeostasis in T2DM mice in such a way that sprouted QY showed the highest hypoglycemic and cholesterol-lowering effects when compared with non-germinated QY.


Assuntos
Chenopodium quinoa/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Hiperglicemia/dietoterapia , Hipoglicemiantes/metabolismo , Metabolismo dos Lipídeos , Iogurte/análise , Animais , Catalase/metabolismo , Chenopodium quinoa/química , Chenopodium quinoa/crescimento & desenvolvimento , Citocinas/metabolismo , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Glucose/metabolismo , Homeostase , Humanos , Hiperglicemia/metabolismo , Hipoglicemiantes/análise , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Sementes/química , Sementes/crescimento & desenvolvimento , Sementes/metabolismo , Transdução de Sinais , Superóxido Dismutase/metabolismo
7.
Zhongguo Zhong Yao Za Zhi ; 45(10): 2239-2248, 2020 May.
Artigo em Chinês | MEDLINE | ID: mdl-32495576

RESUMO

To analyze the development of coronavirus disease 2019(COVID-19), this study systematically retrieved relevant Chinese and English literatures from both CNKI and Web of Science database platforms by bibliometric research method and CiteSpace 5.5.R2 software to obtain information and visualize relevant literatures. A total of 695 Chinese and 446 English literatures were included in this paper. Statistics showed that China had published most of the literatures and established close cooperation with the United States and the United Kingdom. Through the analysis, Tongji Medical College of Huazhong University of Science and Technology and its affiliated hospitals published the largest number of the publications. Moreover, the highly productive journals including Journal of Traditional Chinese Medicine and The Lancet covered eight major fields, such as medicine, medical virology, radiation medicine, infectious disease, and traditional Chinese medicine. Besides, a total of 35 special COVID-19 funds were recently established to subsidize these studies. The key words and themes analysis indicated that protein structure of COVID-19, receptor targets and mechanisms of action, integration of traditional Chinese and Western medicine, screening and development of antiviral drugs from traditional Chinese medicine and Western medicine, vaccine research as well as epidemiological characteristics and prediction are current study hotspots. This study provides a reference for researchers to rapidly master main study directions of COVID-19 and screen out relevant literatures.


Assuntos
Betacoronavirus , Bibliometria , Infecções por Coronavirus , Pandemias , Pneumonia Viral , COVID-19 , China , Humanos , SARS-CoV-2 , Reino Unido , Estados Unidos
8.
Sci Rep ; 10(1): 5978, 2020 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-32249834

RESUMO

In this paper, we present an innovative electric-field-assisted magnetron-sputtering deposition method for films preparation. By grain boundary-engineering, we successeful obtained the ordered Sb2Te3 film with greatly high figure of merit via controlling external electric field. It has been found that the electric field can induce the change in the angle of intraplanar grain boundaries between (0 1 5) and (0 1 5) planes, which leads to the enhanced holes mobility and maintained low thermal conductivity. The energy filtering takes place at the angular intraplanar grain boundaries. At room temperature, a high ZT value of 1.75 can be achieved in the deposited Sb2Te3 film under 30 V external electric field. This is a very promising approach that the electric field induced deposition can develop high-performance Sb2Te3-based thermoelectric films.

9.
R Soc Open Sci ; 6(9): 191007, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31598317

RESUMO

The structural competing and atomic ordering of the full Heusler compounds Fe2NiSi and Ni2FeSi under uniform and tetragonal strains have been systematically studied by the first-principles calculation. Both Fe2NiSi and Ni2FeSi have the XA structure in cubic phase and they show metallic band structures and large magnetic moments (greater than 3µ B ) at equilibrium condition. Tetragonal distortion can further decrease the total energy, leading to the possible phase transformation. Furthermore, different atom reordering behaviours have been observed: for Fe2NiSi, atoms reorder from cubic XA-type to tetragonal L10-type; for Ni2FeSi, there is only structural transformation without atom reordering. The total magnetic moments of Fe2NiSi and Ni2FeSi are mainly contributed by Fe atoms, and Si atom can strongly suppress the moments of Fe atoms when it is present in the nearest neighbours of Fe atoms. With the applied strain, the distance between Fe and Si atoms play an important role for the magnetic moment variation of Fe atom. Moreover, the metallic band nature is maintained for Fe2NiSi and Ni2FeSi under both uniform and tetragonal strains. This study provides a detailed theoretical analysis about the full Heusler compounds Fe2NiSi and Ni2FeSi under strain conditions.

10.
Materials (Basel) ; 11(11)2018 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-30366417

RESUMO

In this work, we systematically studied the structural, electronic, magnetic, mechanical and thermodynamic properties of the fully compensated spin-gapless inverse Heusler Ti2MnAl compound under pressure strain condition by applying the first-principles calculation based on density functional theory and the quasi-harmonic Debye model. The obtained structural, electronic and magnetic behaviors without pressure are well consistent with previous studies. It is found that the spin-gapless characteristic is destroyed at 20 GPa and then restored with further increase in pressure. While, the fully compensated ferromagnetism shows a better resistance against the pressure up to 30 GPa and then becomes to non-magnetism at higher pressure. Tetragonal distortion has also been investigated and it is found the spin-gapless property is only destroyed when c/a is less than 1 at 95% volume. Three independent elastic constants and various moduli have been calculated and they all show increasing tendency with pressure increase. Additionally, the pressure effects on the thermodynamic properties under different temperature have been studied, including the normalized volume, thermal expansion coefficient, heat capacity at constant volume, Grüneisen constant and Debye temperature. Overall, this theoretical study presents a detailed analysis of the physical properties' variation under strain condition from different aspects on Ti2MnAl and, thus, can provide a helpful reference for the future work and even inspire some new studies and lead to some insight on the application of this material.

11.
Sci Rep ; 7(1): 16183, 2017 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-29170544

RESUMO

In this paper, we have investigated the structural, electronic, magnetic, half-metallic, mechanical, and thermodynamic properties of the equiatomic quaternary Heusler (EQH) compound FeCrRuSi using the density functional theory (DFT) and the quasi-harmonic Debye model. Our results reveal that FeCrRuSi is a half-metallic material (HMM) with a total magnetic moment of 2.0 µB in agreement with the well-known Slater-Pauling rule Mt = Zt - 24. Furthermore, the origin of the half-metallic band gap in FeCrRuSi is well studied through a schematic diagram of the possible d-d hybridization between Fe, Cr and Ru elements. The half-metallic behavior of FeCrRuSi can be maintained in a relatively wide range of variations of the lattice constant (5.5-5.8 Å) under uniform strain and the c/a ratio (0.96-1.05) under tetragonal distortion. The calculated phonon dispersion, cohesive and formation energies, and mechanical properties reveal that FeCrRuSi is stable with an EQH structure. Importantly, the compound of interest has been prepared and is found to exist in an EQH type structure with the presence of some B2 disorder. Moreover, the thermodynamic properties, such as the thermal expansion coefficient α, the heat capacity CV, the Grüneisen constant γ, and the Debye temperature ΘD are calculated.

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