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1.
Small ; 20(23): e2308011, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38152965

RESUMO

Sodium-ion batteries (SIBs) have emerged as a promising alternative to lithium-ion batteries for large-scale energy storage systems due to the abundance and low price of sodium. Until recently, the low theoretical capacities of intercalation-type cathodes less than 250 mAh g-1 have limited the energy density of SIBs. On the other hand, iron oxyfluoride (FeOF) has a high theoretical capacity of ≈885 mAh g-1 as a conversion-type cathode material for SIBs. However, FeOF suffers from poor cycling stability, rate capability, and low initial Coulombic efficiency caused by its low electrical conductivity and slow ionic diffusion kinetics. To solve these problems, doping aliovalent Ni2+ on FeOF electrodes is attempted to improve the electronic conductivity without using a carbon matrix. The ionic conductivity of FeOF is also enhanced due to the formation of oxygen defects in the FeOF crystal structure. The FeOF-Ni1 electrode shows an excellent cycling performance with a reversible discharge capacity of 450.4 mAh g-1 at 100 mAh g-1 after 100 cycles with a fading rate of 0.20% per cycle. In addition, the FeOF-Ni1//hard carbon full cell exhibited a high energy density of 876.9 Wh kg-1 cathode with a good cycling stability.

2.
J Nanosci Nanotechnol ; 19(2): 1180-1183, 2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30360229

RESUMO

Monoacrylate-poly(ethylene glycol) grafted poly(3-hydroxyoctanoate) (PEGMA-g-PHO) copolymer was obtained by UV irradiation and ibuprofen (IBU) loaded nanoparticles with PHO or PEGMA-g-PHO polymers were successfully prepared by a single emulsion process. Size of IBU-loaded nanoparticles was about 300 nm based on particle size measurement. Their shapes were spherical. To study drug release properties, IBU release from nanoparticles were performed with FBS buffer. Higher burst release of IBU was observed with the highest graft density of PEGMA groups and 100% drug release was found in 3, 6, and 12 days for PHO, PEGMA-g-PHO0.05, and PEGMA-g-PHO0.15, respectively. Our results suggest that hydrophobic PHO and more hydrophilic PEGMA-g-PHO could be regarded as good candidates of drug release carriers.


Assuntos
Ibuprofeno , Nanopartículas , Portadores de Fármacos , Tamanho da Partícula , Polietilenoglicóis , Polímeros
3.
Water Sci Technol ; 79(6): 1029-1041, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31070583

RESUMO

In the present work, the performance of spent coffee grounds (SCG) as an adsorbent in the treatment of real soil washing wastewater (SWW) was evaluated. Scanning electron microscopy, Fourier transform infrared spectroscopy, zeta potential measurement and Brunauer-Emmett-Teller analysis were utilized to determine the physicochemical characteristics of SCG. Maximum removal efficiency of 68.73% for Cu(II), 57.23% for Pb(II) and 84.55% for Zn(II) was attained at 2.5 g SCG, 300 min and 328 K. Error analysis was performed using root mean square error (RMSE) and sum of square error (SSE). Equilibrium data correlated well with the Langmuir isotherm for Pb(II) adsorption and Freundlich model for the removal of Cu(II) and Zn(II). The kinetic study shows that adsorption of the heavy metals using SCG can be satisfactorily described using the pseudo-second order equation (R2 ≥ 0.9901; RMSE ≤ 15.0539; SSE ≤ 145.1461). Activation parameters including activation energy, change in free energy of activation, activation entropy change (ΔS*) and activation enthalpy change (ΔH*) were determined using Arrhenius and Eyring equations. Thermodynamic studies show that adsorption of the heavy metals using SCG is spontaneous, endothermic (ΔH° ≥ 9.80 kJ/mol·K) and results in increased randomness at the solid/solution interface (ΔS° ≥ 2.28 J/mol).


Assuntos
Metais Pesados/química , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Adsorção , Café/química , Cobre/análise , Cobre/química , Recuperação e Remediação Ambiental , Concentração de Íons de Hidrogênio , Cinética , Chumbo/química , Metais Pesados/análise , Solo/química , Termodinâmica , Águas Residuárias/química , Poluentes Químicos da Água/análise , Zinco/química
4.
BMC Genomics ; 19(1): 481, 2018 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-29921221

RESUMO

BACKGROUND: Face morphology is strongly determined by genetic factors. However, only a small number of genes related to face morphology have been identified to date. Here, we performed a two-stage genome-wide association study (GWAS) of 85 face morphological traits in 7569 Koreans (5643 in the discovery set and 1926 in the replication set). RESULTS: In this study, we analyzed 85 facial traits, including facial angles. After discovery GWAS, 128 single nucleotide polymorphisms (SNPs) showing an association of P < 5 × 10- 6 were selected to determine the replication of the associations, and meta-analysis of discovery GWAS and the replication analysis resulted in five genome-wide significant loci. The OSR1-WDR35 [rs7567283, G allele, beta (se) = -0.536 (0.096), P = 2.75 × 10- 8] locus was associated with the facial frontal contour; the HOXD1-MTX2 [rs970797, A allele, beta (se) = 0.015 (0.003), P = 3.97 × 10- 9] and WDR27 [rs3736712, C allele, beta (se) = 0.293 (0.048), P = 8.44 × 10- 10] loci were associated with eye shape; and the SOX9 [rs2193054, C allele, beta (se) (ln-transformed) = -0.007 (0.001), P = 6.17 × 10- 17] and DHX35 [rs2206437, A allele, beta (se) = -0.283 (0.047), P = 1.61 × 10- 9] loci were associated with nose shape. WDR35 and SOX9 were related to known craniofacial malformations, i.e., cranioectodermal dysplasia 2 and campomelic dysplasia, respectively. In addition, we found three independent association signals in the SOX9 locus, and six known loci for nose size and shape were replicated in this study population. Interestingly, four SNPs within these five face morphology-related loci showed discrepancies in allele frequencies among ethnic groups. CONCLUSIONS: We identified five novel face morphology loci that were associated with facial frontal contour, nose shape, and eye shape. Our findings provide useful genetic information for the determination of face morphology.


Assuntos
Loci Gênicos/genética , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único/genética , Idoso , Feminino , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Genótipo , Proteínas de Homeodomínio/genética , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Fatores de Transcrição SOX9/genética
5.
Phys Chem Chem Phys ; 19(20): 13010-13021, 2017 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-28480933

RESUMO

The elucidation of catalyst surface-plasma interactions is a challenging endeavor and therefore requires thorough and rigorous assessment of the reaction dynamics on the catalyst in the plasma environment. The first step in quantifying and defining catalyst-plasma interactions is a detailed kinetic study that can be used to verify appropriate reaction conditions for comparison and to discover any unexpected behavior of plasma-assisted reactions that might prevent direct comparison. In this paper, we provide a kinetic evaluation of CH4 activation in a dielectric barrier discharge plasma in order to quantify plasma-catalyst interactions via kinetic parameters. The dry reforming of CH4 with CO2 was studied as a model reaction using Ni supported on γ-Al2O3 at temperatures of 790-890 K under atmospheric pressure, where the partial pressures of CH4 (or CO2) were varied over a range of ≤25.3 kPa. Reaction performance was monitored by varying gas hourly space velocity, plasma power, bulk gas temperature, and reactant concentration. After correcting for gas-phase plasma reactions, a linear relationship was observed in the log of the measured rate constant with respect to reciprocal power (1/power). Although thermal catalysis displays typical Arrhenius behavior for this reaction, plasma-assisted catalysis occurs from a complex mixture of sources and shows non-Arrhenius behavior. However, an energy barrier was obtained from the relationship between the reaction rate constant and input power to exhibit ≤∼20 kJ mol-1 (compared to ∼70 kJ mol-1 for thermal catalysis). Of additional importance, the energy barriers measured during plasma-assisted catalysis were relatively consistent with respect to variations in total flow rates, types of diluent, or bulk reaction temperature. These experimental results suggest that plasma-generated vibrationally-excited CH4 favorably interacts with Ni sites at elevated temperatures, which helps reduce the energy barrier required to activate CH4 and enhance CH4 reforming rates.

6.
Biochem Biophys Res Commun ; 478(4): 1609-16, 2016 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-27586274

RESUMO

Treatment of Jurkat T cells with the dynamin inhibitor, myristyl trimethyl ammonium bromides (MiTMAB) caused cytokinesis impairment and apoptotic DNA fragmentation along with down-regulation of anti-apoptotic BAG3 and Mcl-1 levels, Bak activation, mitochondrial membrane potential (Δψm) loss, activation of caspase-9 and -3, and PARP cleavage, without accompanying necrosis. Bcl-xL overexpression completely abrogated these MiTMAB-induced mitochondrial damage and resultant caspase cascade activation, except for impaired cytokinesis and down-regulated BAG3 and Mcl-1 levels. Additionally, autophagic responses including Akt-mTOR pathway inhibition, formation of acridine orange-stainable acidic vesicular organelles, LC3-I/II conversion, and p62/SQSTM1 down-regulation were detected regardless of Bcl-xL overexpression. The autophagy inhibitors 3-methyladenine and LY294002 enhanced MiTMAB-induced apoptotic sub-G1 peak, BAG3 and Mcl-1 down-regulation, Bak activation, Δψm loss, and caspase activation. These results indicate that MiTMAB-caused cytokinesis failure leads to concomitant induction of apoptosis and cytoprotective autophagy, and suggest that inhibition of autophagy is a promising strategy to augment antitumor activity of MiTMAB.


Assuntos
Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Dinaminas/antagonistas & inibidores , Mitocôndrias/metabolismo , Compostos de Trimetil Amônio/farmacologia , Proteína Killer-Antagonista Homóloga a bcl-2/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Anexina A5/metabolismo , Caspases/metabolismo , Ciclo Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cromonas/farmacologia , Fragmentação do DNA/efeitos dos fármacos , Dinaminas/metabolismo , Citometria de Fluxo , Fluoresceína-5-Isotiocianato/metabolismo , Humanos , Células Jurkat , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Morfolinas/farmacologia
7.
Int J Neurosci ; 126(8): 739-48, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26010211

RESUMO

PURPOSE: The purpose was to clarify the influence of frequency and exposure time of pulsed electromagnetic fields (PEMF) on the peripheral nerve regeneration. MATERIALS AND METHODS: Immortalized rat Schwann cells (iSCs) (1 × 10(2)/well) were exposed at four different conditions in 1 mT (50 Hz 1 h/d, 50 Hz 12 h/d, 150 Hz 1 h/d and 150 Hz 12h/d). Cell proliferation, mRNA expression of S100 and brain-derived neurotrophic factor (BDNF) were analyzed. Sprague-Dawley rats (200-250 g) were divided into six groups (n = 10 each): control, sham, 50 Hz 1 h/d, 50 Hz 12 h/d, 150 Hz 1 h/d and 150 Hz 12 Hr/d. Mental nerve was crush-injured and exposed at four different conditions in 1 mT (50 Hz 1 Hr/d, 50 Hz 12 Hr/d, 150 Hz 1 h/d and 150 Hz 12 h/d). Nerve regeneration was evaluated with functional test, histomorphometry and retrograde labeling of trigeminal ganglion. RESULTS: iSCs proliferation with 50 Hz, 1 h/d was increased from fourth to seventh day; mRNA expression of S100 and BDNF was significantly increased at the same condition from first week to third week (p < .05 vs. control); difference score was increased at the second and third week, and gap score was increased at the third under 50 Hz 1 h PEMF compared with control while other conditions showed no statistical meaning. Axon counts and retrograde labeled neurons were significantly increased under PEMF of four different conditions compared with control. Although there was no statistical difference, 50 Hz, 1 h PEMF showed highest regeneration ability than other conditions. CONCLUSION: PEMF enhanced peripheral nerve regeneration, and that it may be due to cell proliferation and increase in BDNF and S100 gene expression.


Assuntos
Magnetoterapia/métodos , Regeneração Nervosa/fisiologia , Traumatismos dos Nervos Periféricos/terapia , Células de Schwann/fisiologia , Animais , Técnicas de Cultura de Células , Masculino , Traumatismos dos Nervos Periféricos/metabolismo , Traumatismos dos Nervos Periféricos/fisiopatologia , Ratos , Ratos Sprague-Dawley
8.
Biochim Biophys Acta ; 1840(1): 322-31, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24080406

RESUMO

BACKGROUND: Nonsteroidal anti-inflammatory drugs (NSAIDs) are well known for treating inflammatory disease and have been reported to have anti-tumorigenic effects. Their mechanisms are not fully understood, but both cyclooxygenase (COX) dependent and independent pathways are involved. Our goal was to shed further light on COX-independent activity. METHODS: Human colorectal cancer cells were observed under differential interference contrast microscopy (DICM), fluorescent microscopy, and micro-impedance measurement. Microarray analysis was performed using HCT-116 cells treated with sulindac sulfide (SS). PCR and Western blots were performed to confirm the microarray data and immunohistochemistry was performed to screen for Nesprin-2 expression. Micro-impedance was repeating including Nesprin-2 knock-down by siRNA. RESULTS: HCT-116 cells treated with SS showed dramatic morphological changes under DICM and fluorescent microscopy, as well as weakened cellular adhesion as measured by micro-impedance. Nesprin-2 was selected from two independent microarrays, based on its novelty in relation to cancer and its role in cell organization. SS diminished Nesprin-2 mRNA expression as assessed by reverse transcriptase and real time PCR. Various other NSAIDs were also tested and demonstrated that inhibition of Nesprin-2 mRNA was not unique to SS. Additionally, immunohistochemistry showed higher levels of Nesprin-2 in many tumors in comparison with normal tissues. Further micro-impedance experiments on cells with reduced Nesprin-2 expression showed a proportional loss of cellular adhesion. CONCLUSIONS: Nesprin-2 is down-regulated by NSAIDs and highly expressed in many cancers. GENERAL SIGNIFICANCE: Our data suggest that Nesprin-2 may be a potential novel oncogene in human cancer cells and NSAIDs could decrease its expression.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Biomarcadores Tumorais/metabolismo , Adesão Celular/efeitos dos fármacos , Neoplasias Colorretais/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Proteínas dos Microfilamentos/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Proteínas Nucleares/metabolismo , Sulindaco/análogos & derivados , Biomarcadores Tumorais/genética , Western Blotting , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/metabolismo , Neoplasias Colorretais/patologia , Impedância Elétrica , Feminino , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Masculino , Proteínas dos Microfilamentos/antagonistas & inibidores , Proteínas dos Microfilamentos/genética , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/genética , Proteínas Nucleares/antagonistas & inibidores , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Estabilidade de RNA/efeitos dos fármacos , RNA Mensageiro/genética , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sulindaco/farmacologia , Análise Serial de Tecidos , Células Tumorais Cultivadas
9.
Int J Mol Sci ; 16(4): 9017-36, 2015 Apr 22.
Artigo em Inglês | MEDLINE | ID: mdl-25913380

RESUMO

Three quinary polar intermetallic compounds in the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 (x = 0.66, y = 0.03) and the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) (x = 0.66, 0.68; y = 0.13, 0.27) phases have been synthesized using the molten In-metal flux method, and the crystal structures are characterized by powder and single-crystal X-ray diffractions. Two orthorhombic structural types can be viewed as an assembly of polyanionic frameworks consisting of the In(Ge/Sn)4 tetrahedral chains, the bridging Ge2 dimers, either the annulene-like "12-membered rings" for the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 series or the cis-trans Ge/Sn-chains for the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) series, and several Eu/Ca-mixed cations. The most noticeable difference between two structural types is the amount and the location of the Sn-substitution for Ge: only a partial substitution (11%) occurs at the In(Ge/Sn)4 tetrahedron in the (Eu(1-x)Ca(x))9In8(Ge(1-y)Sn(y))8 series, whereas both a complete and a partial substitution (up to 27%) are observed, respectively, at the cis-trans Ge/Sn-chain and at the In(Ge/Sn)4 tetrahedron in the (Eu(1-x)Ca(x))3In(Ge(3-y)Sn(1+y)) series. A series of tight-binding linear muffin-tin orbital calculations is conducted to understand overall electronic structures and chemical bonding among components. Magnetic susceptibility measurement indicates a ferromagnetic ordering of Eu atoms below 5 K for Eu1.02(1)Ca1.98InGe2.87(1)Sn1.13.


Assuntos
Complexos de Coordenação/química , Ligas/química , Cálcio/química , Cristalografia por Raios X , Európio/química , Germânio/química , Fenômenos Magnéticos , Conformação Molecular , Difração de Pó , Estanho/química
10.
RSC Adv ; 14(2): 1051-1055, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38174243

RESUMO

Metal-amino acid complexes are important compounds for the human body. Their nutritional value and anticancer, antibacterial, and catalytic properties are the focus of several studies. Density functional theory (DFT) can be used to predict their properties by optimizing their structures and performing electron population analyses. However, conventional computational methods cannot adequately determine the parameters of polymeric metal-amino acid complexes. Therefore, intermolecular interactions of polymers must be considered to correctly predict the properties of metal-amino acid and related metal complexes. In this study, different DFT protocols were used to acquire the infrared spectra and determine interatomic distances of two zinc-amino acid complexes, Zn(Gly)2 and Zn(Met)2. The results were compared to spectroscopic and X-ray crystallographic data, revealing that the M06 and M06-L functionals and the 6-311++G(d,p) basis set produced the smallest computational errors. Our results provide a foundation for future theoretical studies on other metal-amino acid and metal-organic complexes.

11.
Opt Express ; 21(6): 7139-47, 2013 Mar 25.
Artigo em Inglês | MEDLINE | ID: mdl-23546097

RESUMO

Magnetomotive optical coherence tomography (MM-OCT) is a functional extension of OCT which utilizes magnetically responsive materials that are modulated by an external magnetic field for contrast enhancement and for elastography to assess the structural and viscoelastic properties of the surrounding tissues. Traditionally, magnetomotive contrast relies on the interaction between the displacement of magnetic particles induced by an external magnetic field and the micro-environmental restoring (elastic) force acting on the particles. When the restoring force from a sample containing magnetic particles is weak or non-existent, the MM-OCT signal-to-noise ratio (SNR) can degrade significantly. We have developed a novel solenoid configuration to enable MM-OCT imaging in samples that do not have an elastic restoring force, such as liquids. This coil configuration may potentially enable real-time MM-OCT imaging.


Assuntos
Técnicas de Imagem por Elasticidade/instrumentação , Aumento da Imagem/instrumentação , Magnetismo/instrumentação , Soluções/análise , Soluções/química , Tomografia de Coerência Óptica/instrumentação , Desenho de Equipamento , Análise de Falha de Equipamento , Campos Magnéticos
12.
J Hazard Mater ; 460: 132278, 2023 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-37619273

RESUMO

NOX rarely binds with labile oxygens of catalytic solids, whose Lewis acidic (LA) species possess higher binding strengths with NH3 (ENH3) and H2O than Brönsted acidic counterparts (BA--H+; -OH), oftentimes leading to elevate energy barrier (EBARRIER) and weaken H2O tolerance, respectively. These limit NH3-assisted wet NOX reduction via Langmuir-Hinshelwood-type or Eley-Rideal (ER)-type model on LA species, while leaving ER-type analogue on BA--H+ species proper to reduce wet NOX. Given hard-to-regulate strength/amount of -OH species and occasional association between ENH3 and EBARRIER, Ni1V2O6 (Ni1) was rationally chosen as a platform to isolate mono-dentate SO32-/SO42- species for use as BA--H+ bonds via protonation to increase collision frequency (k'APP,0) alongside with disclosure of advantages of SO32-/SO42--functionalized Ni1V2O6 (Ni1-S) over Ni1 in reducing wet NOX. Ni1-S outperformed Ni1 in achieving a larger BA--H+ quantity (k'APP,0↑), increasing H2O tolerance, and elevating oxygen mobility, thus promoting NOX reduction activity/consequences under SO2-excluding gases. V2O5-WO3 composite simulating a commercial catalyst could isolate mono-dentate SO32-/SO42- species and served as a control (V2O5-WO3-S) for comparison. Ni1-S was superior to V2O5-WO3-S in evading ammonium (bi-)sulfate (AS/ABS) poison accumulation and expediting AS/ABS pyrolysis efficiency, thereby improving AS/ABS resistance under SO2-including gases, while enhancing resistance against hydro-thermal aging.

13.
Biomolecules ; 13(1)2023 01 09.
Artigo em Inglês | MEDLINE | ID: mdl-36671516

RESUMO

Poly(3-hydroxybutyrate) (PHB) is a versatile thermoplastic with superior biodegradability and biocompatibility that is intracellularly accumulated by numerous bacterial and archaeal species. Priestia sp. strain JY310 that was able to efficiently biotransform reducing sugars in d-xylose-rich rice husk hydrolysate (reducing sugarRHH) to PHB was isolated from the soil of a rice paddy. Reducing sugarRHH including 12.5% d-glucose, 75.3% d-xylose, and 12.2% d-arabinose was simply prepared using thermochemical hydrolysis of 3% H2SO4-treated rice husk for 15 min at 121 °C. When cultured with 20 g/L reducing sugarRHH under optimized culture conditions in a batch bioreactor, Priestia sp. strain JY310 could produce PHB homopolymer up to 50.4% of cell dry weight (6.2 g/L). The melting temperature, heat of fusion, and thermal decomposition temperature of PHB were determined to be 167.9 °C, 92.1 J/g, and 268.1 °C, respectively. The number average and weight average molecular weights of PHB with a broad polydispersity index value (4.73) were estimated to be approximately 16.2 and 76.8 kg/mol, respectively. The findings of the present study suggest that Priestia sp. strain JY310 can be exploited as a good candidate for the low-cost production of low molecular weight PHB with improved biodegradability and reduced brittleness from inexpensive agricultural waste hydrolysates.


Assuntos
Bacillaceae , Oryza , Ácido 3-Hidroxibutírico , Xilose/metabolismo , Solo , Hidroxibutiratos/metabolismo , Oryza/metabolismo , Peso Molecular , Bacillaceae/metabolismo , Bactérias/metabolismo , Biotransformação
14.
J Hazard Mater ; 416: 125780, 2021 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-33865113

RESUMO

TiO2-supported antimony oxide-vanadium oxide-cerium oxide (SVC) imparts Lewis acidic (L)/Brönsted acidic (B) sites, labile (Oα)/mobile oxygens (OM), and oxygen vacancies (OV) for selective catalytic NOX reduction (SCR). However, these species are harmonious occasionally, readily poisoned by H2O/sulfur/phosphorus/carbon, thus limiting SCR performance of SVC. Herein, a synthetic means is reported for immobilizing HSOA-/SOA2- (A= 3-4) or H3-BPO4B- (B= 1-3) on the L sites of SVC to form SVC-S and SVC-P. HSOA-/SOA2-/H3-BPO4B- acted as additional B sites with distinct characteristics, altered the properties of Oα/OM/OV species, thereby affecting the SCR activities and performance of SVC-S and SVC-P. SVC-P activated Langmuir-Hinshelwood-typed SCR better than SVC-S, as demonstrated by a greater Oα-directed pre-factor and smaller binding energy between Oα and NO. Meanwhile, SVC-S provided a larger B-directed pre-factor, thereby outperforming SVC-P in activating Eley-Rideal-typed SCR that dictated the overall SCR activities. Compared with SVC-S, SVC-P contained fewer OV species, yet, had higher OM mobility, thus enhancing the overall redox cycling feature, while providing greater Brönsted acidity. Consequently, the resistance of SVC-P to H2O or soot were greater than or similar to that of SVC-S. Conversely, SVC-S revealed greater tolerance to hydro-thermal aging and SO2 than SVC-P. This study highlights the pros and cons of HSOA-/SOA2-/H3-BPO4B- functionalities in tailoring the properties of metal oxides in use as SCR catalysts.

15.
J Hazard Mater ; 411: 125144, 2021 06 05.
Artigo em Inglês | MEDLINE | ID: mdl-33858104

RESUMO

Sulfur doped metal oxides were synthesized using a two-step precipitation method. When reacted against neat 2-CEES (2-chloroethyl-ethyl sulfide, a mustard gas simulant) under ambient conditions, sulfur doped mesoporous zinc oxide (MS-Zn) showed higher catalytic activity than the other metal oxides with 92.7% overall conversion in 24 h for a 2.5 µL neat 2-CEES droplet added on top of 2 × 2 cm large 400 mg catalyst layer. The reaction proceeded mainly by hydrolysis and further solvolysis reaction also occurred depending on the extracting solvents. Cyclic sulfonium ion intermediate reaction was thought to be involved in this reaction, and metal oxide surfaces were thought to facilitate the formation of sulfonium ions from adsorbed 2-CEES. All other by-products were also found to form via sulfonium ions, reconfirming the well-known importance of this intermediate species for the degradation reaction to proceed. The sulfur content for MS-Zn was varied and tested for degradation of neat 2-CEES. This modification showed that there is an optimal amount of sulfur content for the peak catalytic activity of MS-Zn for 2-CEES degradation. Adsorption energy of a 2-CEES molecule was calculated on model sulfur doped and non doped zinc oxide surfaces and the different adsorption energy levels were correlated with the catalytic activity of sulfur doped zinc oxide.

16.
JACS Au ; 1(8): 1158-1177, 2021 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-34467355

RESUMO

NO3 • can compete with omnipotent •OH/SO4 •- in decomposing aqueous pollutants because of its lengthy lifespan and significant tolerance to background scavengers present in H2O matrices, albeit with moderate oxidizing power. The generation of NO3 •, however, is of grand demand due to the need of NO2 •/O3, radioactive element, or NaNO3/HNO3 in the presence of highly energized electron/light. This study has pioneered a singular pathway used to radicalize surface NO3 - functionalities anchored on polymorphic α-/γ-MnO2 surfaces (α-/γ-MnO2-N), in which Lewis acidic Mn2+/3+ and NO3 - served to form •OH via H2O2 dissection and NO3 • via radical transfer from •OH to NO3 - (•OH → NO3 •), respectively. The elementary steps proposed for the •OH → NO3 • route could be energetically favorable and marginal except for two stages such as endothermic •OH desorption and exothermic •OH-mediated NO3 - radicalization, as verified by EPR spectroscopy experiments and DFT calculations. The Lewis acidic strength of the Mn2+/3+ species innate to α-MnO2-N was the smallest among those inherent to α-/ß-/γ-MnO2 and α-/γ-MnO2-N. Hence, α-MnO2-N prompted the rate-determining stage of the •OH → NO3 • route (•OH desorption) in the most efficient manner, as also evidenced by the analysis on the energy barrier required to proceed with the •OH → NO3 • route. Meanwhile, XANES and in situ DRIFT spectroscopy experiments corroborated that α-MnO2-N provided a larger concentration of surface NO3 - species with bi-dentate binding arrays than γ-MnO2-N. Hence, α-MnO2-N could outperform γ-MnO2-N in improving the collision frequency between •OH and NO3 - species and in facilitating the exothermic transition of NO3 - functionalities to surface NO3 • analogues per unit time. These were corroborated by a greater efficiency of α-MnO2-N in decomposing phenol, in addition to scavenging/filtration control runs and DFT calculations. Importantly, supported NO3 • species provided 5-7-fold greater efficiency in degrading textile wastewater than conventional •OH and supported SO4 •- analogues we discovered previously.

17.
ACS Appl Mater Interfaces ; 13(3): 3782-3792, 2021 Jan 27.
Artigo em Inglês | MEDLINE | ID: mdl-33461292

RESUMO

Metal organic frameworks (MOFs) have been suggested as promising materials for application in the degradation of chemical warfare agents, with the majority of studies to date focusing on nerve agents. One of the most prominent MOFs used in the detoxification of nerve agents is UiO-66, which is of interest as a future nerve agent decontaminant. However, blister agents, which constitute one of the most toxic and highly reactive categories of chemical agents, are yet to be examined as gas-phase decontamination targets using MOF structures. In this study, a novel type of UiO-66 with a smaller particle size, namely, UiO-66S, was used as a decontaminant for the blister agent simulant, 2-chloroethyl ethyl sulfide (2-CEES). The gas-phase chemical adsorption and decomposition of 2-CEES were demonstrated for the first time, with an estimated t1/2 of 1.34 h. This value is the highest reported value for an MOF in gas-phase reaction conditions. The obtained nontoxic degradation products were identified, and the reaction mechanism was studied using density functional theory calculations. Furthermore, the synthesized UiO-66S catalyst also exhibits superior catalytic ability toward nerve agent simulants (diisopropyl fluorophosphate).The results of the study provide a firm basis for the use of UiO-66S as a future decontaminant for both nerve and blister agents.

18.
World J Gastroenterol ; 27(23): 3342-3356, 2021 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-34163116

RESUMO

BACKGROUND: Inflammatory bowel diseases (IBD) is related to uncontrolled immune response. Currently, there is no successful treatment for significant improvement in IBD. Stem cells display their therapeutic effects through their repopulating capacity or secreting factors. AIM: To investigate the effects of conditioned mouse adipose-derived stem cells (mADSCs) secretome on colitis-induced mice. METHODS: mADSCs were isolated from adipose tissue of C57BL/6 mice. Conditioned mADSCs secrectome was obtained by culturing of mADSCs with lipopolysaccharides (LPS, 1 µg/mL) for 24 h. Acute colitis was induced by 2% dextran sulfate sodium (DSS) drinking water for 7 d and then normal drinking water for 4 d. The mice were treated with normal culture medium (NM group), conditioned mADSCs secretome (CM group) or mADSCs (SC group). The length of colon and histopatholgy of colon tissues were evaluated. The mRNA expression levels of inflammatory cytokines in colon tissue and the serum interleukin (IL)-6 levels were determined. RESULTS: The isolated mADSCs maintained the mADSCs specific gene expression profiles during experiment. The conditioned mADSCs secretome released by the treatment of mADSCs with LPS contained mainly inflammatory chemokines, colony-stimulating factors and inflammatory cytokines. The loss of body weight and reduction in colon length were ameliorated in the CM group. The conditioned mADSCs secretome reduced the histological score in colon tissue. The expression of IL-1b and IL-6 mRNAs in colon tissues significantly inhibited in the CM group compared to SC group and NM group, respectively. The elevation of serum IL-6 levels was also ameliorated in the CM group. These results indicate that the conditioned mADSCs secretome suppressed the synthesis of inflammatory cytokines in damaged colon tissue and the elevation of serum IL-6 concentration in DSS-induced mice. CONCLUSION: Conditioned mADSCs secretome might play regenerative roles by the suppression of IL-6 in serum and tissue during acute colitis, and may be more effective than stem cells themselves in the regeneration of colon tissue.


Assuntos
Colite , Tecido Adiposo , Animais , Colite/induzido quimicamente , Colite/terapia , Colo , Citocinas , Sulfato de Dextrana/toxicidade , Modelos Animais de Doenças , Camundongos , Camundongos Endogâmicos C57BL , Células-Tronco
19.
J Am Chem Soc ; 132(47): 16825-40, 2010 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-21053901

RESUMO

Iron phosphates (FePO(4)) are among the most promising candidate materials for advanced Li-ion battery cathodes. This work reports upon a combined nuclear magnetic resonance (NMR) experimental and periodic density functional theory (DFT) computational study of the environments and electronic structures occurring in a range of paramagnetic Fe(III) phosphates comprising FePO(4) (heterosite), monoclinic Li(3)Fe(2)(PO(4))(3) (anti-NASICON A type), rhombohedral Li(3)Fe(2)(PO(4))(3) (NASICON B type), LiFeP(2)O(7), orthorhombic FePO(4)·2H(2)O (strengite), monoclinic FePO(4)·2H(2)O (phosphosiderite), and the dehydrated forms of the latter two phases. Many of these materials serve as model compounds relevant to battery chemistry. The (31)P spin-echo mapping and (7)Li magic angle spinning NMR techniques yield the hyperfine shifts of the species of interest, complemented by periodic hybrid functional DFT calculations of the respective hyperfine and quadrupolar tensors. A Curie-Weiss-based magnetic model scaling the DFT-calculated hyperfine parameters from the ferromagnetic into the experimentally relevant paramagnetic state is derived and applied, providing quantitative finite temperature values for each phase. The sensitivity of the hyperfine parameters to the composition of the DFT exchange functional is characterized by the application of hybrid Hamiltonians containing admixtures 0%, 20%, and 35% of Fock exchange. Good agreement between experimental and calculated values is obtained, provided that the residual magnetic couplings persisting in the paramagnetic state are included. The potential applications of a similar combined experimental and theoretical NMR approach to a wider range of cathode materials are discussed.

20.
Mol Carcinog ; 49(10): 913-21, 2010 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-20721975

RESUMO

Based on the important role of microRNA (miRNA) biosynthesis genes in carcinogenesis, we hypothesized that polymorphisms in the miRNA biosynthesis genes may modulate susceptibility to lung cancer. To test this hypothesis, we conducted a two-stage study to evaluate the associations between single nucleotide polymorphisms (SNPs) in the miRNA biosynthesis genes and the risk of lung cancer. In stage 1 of the study, 24 SNPs in the 11 miRNA biosynthesis genes (DROSHA, DGCR8, RAN, XPO5, DICER, AGO1, AGO2, HIWI, GEMIN3, GEMIN4, and TRBP) were genotyped in 100 lung cancer patients and 100 healthy controls using a sequenome mass spectrometry-based genotyping assay. One promising SNP (AGO1 rs636832A > G) was selected for stage 2 of the study, and genotyped by a melting-curve analysis using fluorescence-labeled hybridization probes in an independent set of 552 cases and 552 controls. The AGO1 rs636832A > G exhibited highly consistent results between the two stages of the study. In combined analysis, the 636832A > G was associated with a significantly decreased risk of lung cancer in a dose-dependent manner (P(trend) = 6.0 × 10(-4)). Individuals with at least one rs636832G allele were at a significantly decreased risk of lung cancer compared with those with the AA genotype (adjusted odds ratio = 0.67, 95% confidence interval = 0.53-0.84, P = 4.0 × 10(-4)). This finding suggests that the AGO1 rs636832A > G might be a useful marker for determining the susceptibility to lung cancer and that the AGO1 gene might be involved in the development of lung cancer.


Assuntos
Fatores de Iniciação em Eucariotos/genética , Neoplasias Pulmonares/genética , Polimorfismo de Nucleotídeo Único/genética , Idoso , Proteínas Argonautas , Estudos de Casos e Controles , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Risco , Fumar
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