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1.
Phys Chem Chem Phys ; 23(5): 3588-3594, 2021 Feb 07.
Artigo em Inglês | MEDLINE | ID: mdl-33522522

RESUMO

The thermodynamics of phosphorus (P) doping to spinel Co3O4, for both bulk cases and (100) and (110) surface cases, is studied using first principles calculations. The doping energies of the P atom at different doping sites are carefully calculated and compared. It is shown that P doping at Co sites, at either tetrahedral or octahedral sites, is energetically favorable, while P doping and replacing O atoms are energetically unfavorable. The doping energy difference is large enough to conclude that P doping has a very strong preference to take the Co sites, rather than the O sites in spinel Co3O4. Even when O-vacancy is available, P doping and taking the O-vacancy site is thermodynamically unfavorable. The physical/chemical mechanism behind this phenomenon is carefully analyzed. Electronic structure analysis shows that P doping and replacing the Co atom brings excess electrons to the Co3O4 system, which is beneficial to enhance the electrochemical and catalytic performance of the spinel Co3O4. Our results clarified the misleading results of P doping and replacing O atoms in spinel Co3O4 reported in the literature.

2.
Phys Chem Chem Phys ; 22(35): 19623-19630, 2020 Sep 21.
Artigo em Inglês | MEDLINE | ID: mdl-32856670

RESUMO

In this paper, H solution behaviors are systematically studied under varied external tensile/compressive strains in bcc W using first-principles calculations. The results show that the H solution energy is not only dependent on the ground state energy of the W lattice, but also strongly dependent on the entropy effect. The entropy effect includes not only the contribution from lattice vibrations, but also the configurational entropy of the H distribution in the interstitial sites. As the entropy effect is directly associated with the temperature, the H solubility in W is strongly dependent on the temperature and the magnitude of the H solubility is increased from 3 × 10-18 at 300 K to 1.1 × 10-3 at 1800 K under strain free conditions. The results also show that external strain can also play an important role in changing the H solution behavior in W. Tensile strain promotes the H solubility while compressive strain suppresses the solution of H.

3.
Phys Chem Chem Phys ; 22(16): 8864-8869, 2020 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-32285889

RESUMO

A first-principles calculation was performed to investigate the switchable CO2 capture on χ3-borophene by injecting/removing the extra electrons. The results show that the CO2 adsorption energy on the neutral χ3-borophene is 0.150 eV. After extra 2.5 e are injected, the adsorption energy is raised up to 0.802 eV, showing a significant enhancement with the change from the physical adsorption to chemical adsorption. Furthermore, both the CO2 capture and release processes are exothermic reactions involving injecting/removing extra electrons. χ3-borophene possesses a metallic electronic structure, which is conducive to the injection of extra electrons. The minimum charge density for CO2 capture on the negatively charged χ3-borophene is 1.6 × 1014 e cm-2. The CO2 capture capacity of χ3-borophene is 4.09 × 1014 cm-2. Finally, we study the selectivity of negatively charged χ3-borophene. The results show that the negatively-charged χ3-borophene possesses a high selectivity for CO2 from its mixtures with CO, CH4, NH3, N2, H2S, and H2. χ3-borophene is a new promising charge-modulated switchable CO2 capture material with good stability, high CO2 capture capacity, high selectivity, and excellent electrical conductivity.

4.
Biol Pharm Bull ; 38(6): 862-8, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26027825

RESUMO

Berberine is a natural product that shows benefits for metabolic syndrome (MS). However, the effects of berberine on the improvement of vascular inflammation and remodeling in MS remain unclear. This study aimed to investigate whether berberine could prevent vascular remodeling and inflammation in the MS condition. A rat model of MS was established, and MS rats were divided into two groups: MS group without berberine treatment, and MSB group with berberine treatment (each group n-10). Ten normal Wistar rats were used as controls (NC group). Vascular damage was examined by transmission electron microscopy and pathological staining. Compared to the NC group, the secretion of inflammatory factors was increased and the aortic wall thicker in the MS group. The MSB group exhibited decreased secretion of inflammatory factors and improved vascular remodeling, compared to the MS group. In addition, the levels of p38 mitogen-activated protein kinase (p38 MAPK), activating transcription factor 2 (ATF-2) and matrix metalloproteinase 2 (MMP-2) were significantly decreased in the MSB group compared to the MS group. In conclusion, our data show that berberine improves vascular inflammation and remodeling in the MS condition, and this is correlated with the ability of berberine to inhibit p38 MAPK activation, ATF-2 phosphorylation, and MMP-2 expression.


Assuntos
Berberina/uso terapêutico , Inflamação/prevenção & controle , Síndrome Metabólica/tratamento farmacológico , Fitoterapia , Extratos Vegetais/uso terapêutico , Remodelação Vascular/efeitos dos fármacos , Fator 2 Ativador da Transcrição/metabolismo , Animais , Aorta/efeitos dos fármacos , Aorta/patologia , Berberina/farmacologia , Modelos Animais de Doenças , Inflamação/metabolismo , Mediadores da Inflamação/metabolismo , Masculino , Metaloproteinase 2 da Matriz/metabolismo , Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Síndrome Metabólica/patologia , Fosforilação , Extratos Vegetais/farmacologia , Ratos Wistar , Transdução de Sinais , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 2): o347, 2011 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-21523028

RESUMO

In the title compound, C(23)H(20)N(4)OS, the two phenyl rings of the diphenyl-propanone fragment form a dihedral angle of 86.8 (1)°, and the third phenyl ring attached to the triazole ring is twisted from the latter at 40.1 (1)°. In the crystal, mol-ecules are paired into centrosymmetric dimers via pairs of inter-molecular N-H⋯O and N-H⋯S hydrogen bonds.

6.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): o1609, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21837017

RESUMO

In the title mol-ecule, C(16)H(16)N(4)O(2)S, the plane of the 1,2,4-triazole ring forms dihedral angles of 77.9 (2) and 30.0 (2)° with the planes of the furyl and phenyl rings, respectively. Weak inter-molecular N-H⋯S and C-H⋯O hydrogen bonds consolidate the crystal packing.

7.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 7): o1794, 2011 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-21837167

RESUMO

In the title mol-ecule, C(23)H(19)ClN(4)OS, the 1,2,4-triazole ring forms dihedral angles of 46.5 (2), 87.4 (2) and 80.9 (2) Šwith the three six-membered rings. Weak inter-molecular N-H⋯S and C-H⋯O hydrogen bonds consolidate the crystal packing.

8.
Acta Crystallogr Sect E Struct Rep Online ; 66(Pt 12): o3085, 2010 Nov 06.
Artigo em Inglês | MEDLINE | ID: mdl-21589392

RESUMO

The asymmetric unit of the title compound, C(17)H(12)N(4)S(4), contains one half-mol-ecule situated on a twofold rotational axis. In the mol-ecule, the thia-diazole and attached phenyl rings are twisted by 5.8 (3)°.

9.
Aging (Albany NY) ; 12(7): 6018-6029, 2020 04 07.
Artigo em Inglês | MEDLINE | ID: mdl-32259795

RESUMO

To ameliorate multidrug resistance (MDR) observed in leukemia cells, nanomicelles modified by transferrin (Tf-M-DOX/PSO), coencapsulating doxorubicin (DOX) and psoralen (PSO), were designed, synthesized and tested in K562 and doxorubicin-resistant K562 (K562/DOX) cells. In vitro drug release kinetics for constructed nanomicelles were measured using high-performance liquid chromatography. Characterization of the produced nanomicelles was completed using transmission electron microscopy and dynamic light scattering. Uptake of the nanomicelles in K562 cells was investigated using both confocal microscopy and flow cytometry. Apoptosis levels as well as the expression of glycoprotein (P-gp) were analyzing by western blotting and flow cytometry. Cellular cytotoxicity resulting from the exposure of nanomicelles was evaluated using MTT assays. The nanomicelles all showed mild release of DOX in PBS solution. In K562/DOX cells, Tf-M-Dox/PSO exhibited higher uptake compared to the other nanomicelles observed. Furthermore, cellular cytotoxicity when exposed to Tf-M-Dox/PSO was 2.8 and 1.6-fold greater than observed in the unmodified DOX and Tf-nanomicelles loaded with DOX alone, respectively. Tf-M-Dox/PSO strongly increased apoptosis of K562/DOX cells. Finally, the reversal of the drug resistance when cells are exposed to Tf-M-DOX/PSO was associated with P-gp expression inhibition. The Tf-M-Dox/PSO nanomicelle showed a reversal of MDR, with enhanced cellular uptake and delivery release.


Assuntos
Apoptose , Doxorrubicina/farmacocinética , Resistência a Múltiplos Medicamentos , Resistencia a Medicamentos Antineoplásicos , Ficusina/farmacocinética , Leucemia/tratamento farmacológico , Nanoestruturas , Transferrina/farmacocinética , Membro 1 da Subfamília B de Cassetes de Ligação de ATP/análise , Antibióticos Antineoplásicos/farmacocinética , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Encapsulamento de Células , Sobrevivência Celular/efeitos dos fármacos , Sistemas de Liberação de Medicamentos , Humanos , Células K562 , Teste de Materiais/métodos
10.
RSC Adv ; 9(47): 27378-27385, 2019 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-35529228

RESUMO

Searching for electrode materials for non-lithium metal ion batteries (NLMIBs) is key to the success of NLMIBs. In this work, we investigated the scientific feasibility of using g-Mg3N2, which is a novel 2D graphene-like material, as an anode for non-lithium metal-ions (Na, K, Mg, Ca and Al) batteries based on density functional theory calculations. The sequential adsorption energy, Bader charge, intercalation voltage, energy-storage capacity, electronic conductivity and metal-ion diffusion energy barrier are calculated. Results show that the metal-ion intercalation potentials and diffusion energy barriers are suitable for battery application. The maximum specific capacities for Na-, K-, Mg-, Ca- and Al-ion on g-Mg3N2 are predicted to be 797, 797, 531, 1594 and 797 mA h g-1, respectively. The excellent structural stability of g-Mg3N2 is good for the cycling performance. Moreover, the electronic structure of the g-Mg3N2 changes from semiconductor to metal upon metal-ion adsorption, as well as relatively low metal-ion diffusion energy barriers (except for Al-ion diffusion), are beneficial to the charge/discharge rate of the g-Mg3N2 anode.

11.
Nanoscale Res Lett ; 14(1): 260, 2019 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-31363867

RESUMO

From first principles calculations, a novel pentagonal Si/C complexity is predicted to have potential applications as a promising anode material for Li-ion batteries. It is found that the structural and thermal stability of the penta-siligraphene (P-Si2C4) is better than penta-graphene that is composed of C atoms only. Electronic band structure analysis shows that the empty C-2pz state in the P-Si2C4 provides space to accommodate and stabilize electrons from Li, which makes Li storage energetically favorable. As a result, four Li atoms can be stored by one formula unit of the P-Si2C4, corresponding to a theoretical gravimetric Li storage capacity of 1028.7 mAhg-1. The metallic electronic structures of the Li-adsorbed P-LixSi2C4 as well as very small Li migration energy barriers are beneficial for fast charge/discharge performance of the battery. The mechanism on the Li adsorption interaction on the P-Si2C4 is discussed. These results demonstrate a novel strategy to design two-dimensional Si/C complex anode materials for high-performance Li-ion batteries.

12.
Medicine (Baltimore) ; 97(21): e10861, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29794786

RESUMO

Asthma has been the most common chronic disease in children that places a major burden for affected people and their families.An integrated analysis of microarrays studies was performed to identify differentially expressed genes (DEGs) in childhood asthma compared with normal control. We also obtained the differentially methylated genes (DMGs) in childhood asthma according to GEO. The genes that were both differentially expressed and differentially methylated were identified. Functional annotation and protein-protein interaction network construction were performed to interpret biological functions of DEGs. We performed q-RT-PCR to verify the expression of selected DEGs.One DNA methylation and 3 gene expression datasets were obtained. Four hundred forty-one DEGs and 1209 DMGs in childhood asthma were identified. Among which, 16 genes were both differentially expressed and differentially methylated in childhood asthma. Natural killer cell mediated cytotoxicity pathway, Jak-STAT signaling pathway, and Wnt signaling pathway were 3 significantly enriched pathways in childhood asthma according to our KEGG enrichment analysis. The PPI network of top 20 up- and downregulated DEGs consisted of 822 nodes and 904 edges and 2 hub proteins (UBQLN4 and MID2) were identified. The expression of 8 DEGs (GZMB, FGFBP2, CLC, TBX21, ALOX15, IL12RB2, UBQLN4) was verified by qRT-PCR and only the expression of GZMB and FGFBP2 was inconsistent with our integrated analysis.Our finding was helpful to elucidate the underlying mechanism of childhood asthma and develop new potential diagnostic biomarker and provide clues for drug design.


Assuntos
Asma/genética , Proteínas de Transporte/genética , Metilação de DNA/genética , Perfilação da Expressão Gênica/métodos , Biomarcadores/metabolismo , Criança , Redes Reguladoras de Genes/imunologia , Humanos , Proteínas Nucleares , Mapas de Interação de Proteínas , RNA Mensageiro/genética , Transdução de Sinais/genética
13.
J Phys Condens Matter ; 30(34): 345501, 2018 Aug 30.
Artigo em Inglês | MEDLINE | ID: mdl-30020082

RESUMO

It was reported by Hu et al (2015 ACS Appl. Mater. Interfaces 7 24016) that Li adsorption on the Ca2N monolayer is energetically unfavorable, although it was found to be a good candidate for Na storage. In this paper, from first-principles calculations, it is shown that compressive stain can greatly enhance the interactions between Li adsorbate and the Ca2N host, which is beneficial to prevent Li from clustering on the surface and thus Li storage becomes possible. Charge distribution analysis further shows that the enhanced Li-adsorption is a result of the increased surface charge density and the more confined charge distribution under compressive strain. Inspired by this observation, several electron-donor-doped Ca2N materials are considered as anode materials for Li-ion batteries. Results show that the O and F doped Ca2N have the best performance, with predicted Li storage capacity reaching about 567.9 and 565.9 mAh g-1 for O and F doped cases, respectively. It is also demonstrated that electron-donor doping does not change the metallic electronic structures and the low Li-ion migration energy barriers on the surface of the Ca2N monolayer, and thus the rate performance of the doped Ca2N can be as good as the undoped case. Our study offers a deep understanding of the Li interactions with 2D materials and provides an approach of material modification to 2D electrides for battery applications.

14.
Acta Crystallogr E Crystallogr Commun ; 71(Pt 12): o1080-1, 2015 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-26870508

RESUMO

The title compound, C32H28N4O2S, crystallizes as a racemate. In the mol-ecule, the bond-angle sum at the C atom of the sulfanyl-idene entity bound to the triazole ring is 360°, with an annular N-C-N bond angle of 102.6 (2)° and two larger N-C-S angles of 127.3 (2) and 130.1 (2)°. The essentially planar 1,2,4-triazole ring (r.m.s. deviation = 0.013 Å) is nearly perpendicular to the phenylpropanone and methoxyphenyl rings , making dihedral angles of 76.9 (2) and 85.2 (2)°, respectively and subtends dihedral angles of 17.6 (2) and 40.3 (2)° with the tolyl and benzylideneamino rings, respectively. There is no π-π stacking between the mol-ecules. The crystal packing is dominated by weak C-H⋯O and C-H⋯N inter-actions, leading to a three-dimensional network structure. An intra-molecular C-H⋯S inter-action also occurs.

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