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1.
Biol Chem ; 402(10): 1247-1256, 2021 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-34363384

RESUMO

Renal cell carcinoma (RCC) is the third most frequent malignancy within urological oncology. Sunitinib has been used as the standard of treatment for first-line RCC therapy. Understanding mechanisms of sunitinib resistance in RCC cell is important for clinical therapy and drug development. We established sunitinib resistant RCC cells by treating cells with increasing concentrations of sunitinib and named resistant cells as RCC/SR. Lefty A, an important embryonic morphogen, was increased in RCC/SR cells. Targeted inhibition of Lefty via its siRNAs restored the sensitivity of renal resistant cells to sunitinib treatment. It was due to that si-Lefty can decrease the expression of interleukin-8 (IL-8) in RCC/SR cells. Knockdown of IL-8 abolished Lefty-regulated sunitinib sensitivity of RCC cells. Mechanistically, Lefty can regulate IL-8 transcription via activation of p65, one major transcription factor of IL-8. Collectively, our present revealed that Lefty A can regulate sunitinib sensitivity of RCC cells of via NF-κB/IL-8 signals. It indicated that targeted inhibition of Lefty might be a potent approach to overcome sunitinib resistance of RCC.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Sunitinibe , Humanos , Interleucina-8/metabolismo
2.
RSC Adv ; 14(24): 16747-16757, 2024 May 22.
Artigo em Inglês | MEDLINE | ID: mdl-38784407

RESUMO

One of the main obstacles to the development of sustainable biomass feedstocks today is the research of selective hydrogenation of biomass platform compounds for the synthesis of high-value chemicals. This work reports on the synthesis of a Ni/Fe bimetallic catalyst with nitrogen-doped carbon serving as the carrier, hydrogen serving as the primary donor, and isopropanol serving as the reaction medium and serving as a secondary donor. Vanillin was catalytically hydrogenated to produce 4-methylguaiacol, a complete hydrogenation product, under a reaction temperature of 200 °C for four hours. A single product with a good yield (95.26% conversion and selectivity up to 99%) was achieved by the moderate conditions, offering a potential route for the catalytic hydrogenation of biomass platform compounds.

3.
ACS Appl Mater Interfaces ; 15(30): 36201-36213, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37464747

RESUMO

Fe-based MOFs (Fe-MOFs) are deemed promising Fenton-like catalysts due to their well-developed pores and accessible active sites. However, their inferior catalytic activity, iron leaching, and low H2O2 utilization always hinder their application as Fe-based MOF catalysts. In this work, we manipulated the structure of Fe-oxo nodes in MIL-88B(Fe) via a CuI species substitution method, affording a mixed-valence (Cu-incorporated Fe-MOFs) with highly improved Fenton-like performance. It is found that the CuI serves as a shuttle to promote transfer between FeII/FeIII, inducing the formation of a larger amount of stable FeII sites, which was proven by experimental and DFT calculation results. A linear relationship was observed for the Fenton-like performance and the amount of CuI species for the catalysts. The corresponding value of the •OH formation is 2.17 eV for Cu-incorporated MIL-88B(Fe), which is significantly lower than that of MIL-88B(Fe) (2.69 eV). Meanwhile, the enriched CuI species suppress Fe species leaching during the catalytic reaction. The Fe-ion leakage of 0.4Cu@MIL-88B is very tiny (0.01-0.03 mg/L), significantly less than that of MIL-88B (2.00-3.02 mg/L). At the same time, H2O2 utilization for 0.4Cu@ MIL-88B(Fe) is 88%, which is almost 4.4 times that of pure MIL-88B(Fe). This work provides insights into the rational design of Fe-MOFs as promising Fenton-like catalysts for wastewater treatment.

4.
iScience ; 26(9): 107671, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37680471

RESUMO

Deep eutectic solvents (DESs) are increasingly being recognized as sustainable and promising solvents because of their unique properties: low melting point, low cost, and biocompatibility. Some DESs possess high viscosity, remarkable stability, and minimal toxicity, enhancing their appeal for diverse applications. Notably, they hold promise in biomass pretreatment, a crucial step in biomass conversion, although their potential in algal biomass carbohydrates extraction remains largely unexplored. Understanding the correlation between DESs' properties and their behavior in carbohydrate extraction, alongside cellulose degradation mechanisms, remains a gap. This review provides an overview of the use of DESs in extracting carbohydrates from lignocellulosic and algal biomass, explores the factors that influence the behavior of DESs in carbohydrate extraction, and sheds light on the mechanism of cellulose degradation by DESs. Additionally, the review discusses potential future developments and applications of DESs, particularly extracting carbohydrates from algal biomass.

5.
ACS Appl Mater Interfaces ; 15(3): 4184-4193, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36626197

RESUMO

Metal-oxide interaction was widely observed in supported metal catalysts, playing a significant role in tuning the catalytic performance. Here, we reported that the interaction of Ru and MnOx was able to facilitate the hydrodeoxygenation of levulinic acid (LA) to 2-butanol with a high turnover frequency (1.99 × 106 h-1), turnover number (4411), and yield (98.8%). Moreover, this catalyst was capable of removing the hydroxymethyl group of lactones and diol with high yields of products. The high activity of the Ru-MnOx catalyst was due to the strong Ru-MnOx interaction, which facilitated reduction of Ru oxide to Ru0 and Mn oxide to Mn2+. The increased fractions of Ru0 and Mn2+ provided metal and Lewis acid sites, respectively, and therefore facilitated LA hydrodeoxygenation. A linear correlation between the hydrodeoxygenation activity of the Ru-MnOx catalyst and [Mn2+]ln([Ru0]) was observed.

6.
Bioresour Technol ; 372: 128653, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36682474

RESUMO

Aviation fuel is high energy density and is usually produced from refinery in petroleum industry. Production of renewable aviation fuel from biomass eases pressure of carbon emission regulation. The operational processes in this study include steam stripping, hydrolysis of residues, condensation reaction unit, autoclave hydrogenation, fixed-bed hydrodeoxygenation, and oil-upgrading unit. The biomass-derived aviation fuel has a low oxygen content of 0.4 %, while its high heat value is 45.5 MJ/kg. The aviation fuel ranges from C8 âˆ¼ C15, and rich in isoparaffins (50.4 %) while the n-paraffins have a selectivity of 12.2 % and other components are cycloparaffins (19.0 %), aromatic hydrocarbons (11.3 %), and alkenes (5.6 %). The mass yield for aviation fuel from corn stover reaches 10.6 %. This pilot study achieved production of aviation fuel from raw biomass corn stover.


Assuntos
Aviação , Zea mays , Projetos Piloto , Temperatura Alta , Hidrogenação , Biomassa
7.
Bioresour Technol ; 347: 126403, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34826560

RESUMO

Herein, WOx-decorated Ir/SiO2 (W/Ir = 0.06) and HZSM-5 were coupled to selectively convert microcrystalline cellulose (MCC) into C6 alkanes. A 92.8% yield of liquid alkanes including an 85.3% yield of C6 alkanes was produced at 210 °C. Cellulose hydrolysis, glucose hydrogenation and sorbitol hydrodeoxygenation were integrated to produce alkanes via a sorbitol route. Ir-WOx/SiO2 showed high performance for hydrogenation and hydrodeoxygenation reactions after hydrolysis catalyzed by HZSM-5. The intimate contact between WOx and Ir enhanced the synergistic interaction through the electron transfer from Ir to WOx. The interaction strengthened the reduction capability of Ir for hydrogenations, as well as improved the adsorption and activation of C-O bonds on reduced WOx for deoxygenations. The monotungstate WOx species provided moderate Lewis acids to cooperate with Ir to accelerate hydrodeoxygenations with alleviated retro-aldol condensation to yield more C6 alkanes.


Assuntos
Alcanos , Dióxido de Silício , Catálise , Celulose , Irídio , Óxidos , Tungstênio
8.
ACS Omega ; 3(7): 7407-7417, 2018 Jul 31.
Artigo em Inglês | MEDLINE | ID: mdl-31458900

RESUMO

Crystal α-zirconium phosphate (α-ZrP) was prepared by a hydrothermal method and exfoliated into a layered structure by n-hexylamine (C6H13NH2). Ni-based catalyst (Ni/ZrP) was promoted by loading nickel on the layered α-ZrP via ion exchange. The catalyst was performed to catalyze hydrodeoxygenation of 5-hydroxymethylfurfural (HMF) to 2,5-dimethylfuran (DMF), and a 68.1% yield of DMF and 100% conversion of HMF were achieved at 240 °C, 5 MPa H2, and 20 h. The DMF yield can still retain 52.8% after five cycles. The characteristics of the catalyst were investigated via N2 adsorption-desorption, X-ray diffraction, field emission scanning electron microscopy, high-resolution transmission electron microscopy, pyridine-adsorbed Fourier transform infrared (FTIR) spectra, FTIR spectra, inductively coupled plasma mass spectrometry, and thermogravimetric analysis-mass spectrometry, as well as Raman spectroscopy. A pathway from HMF to DMF was found with MF as the intermediate product, and DMF production was preferable via the -CH2OH group hydrogenolysis of HMF over Lewis acidic sites of Ni/ZrP, which is caused by the zirconium vacant orbits.

9.
RSC Adv ; 8(71): 40989-40995, 2018 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-35557899

RESUMO

Novel catalytic material with high catalytic activity and hydrothermal stability plays a key role in the efficient conversion of levulinic acid (LA) to γ-valerolactone (GVL) in water. In this study, mixed oxides Al2O3-TiO2, Al2O3-MoO3 and Al2O3-Co3O4 were synthesized by co-precipitation using aqueous solution of NaOH as precipitant. Ru catalysts supported on mixed oxides were prepared by impregnation method and their catalytic performances were tested in the hydrogenation of LA to GVL on a fixed bed reactor. The physicochemical properties of the catalysts were characterized by XRD, H2-TPR, NH3-TPD, and BET techniques. The TiO2 component significantly affected the acidity of the catalyst, and thus its catalytic activity for the GVL yield was affected. The desired product GVL with a yield of about 97% was obtained over the Ru/Al2O3-TiO2 catalyst under mild conditions (WHSV = 1.8 h-1, T = 80 °C). Moreover, the catalyst Ru/Al2O3-TiO2 exhibited excellent thermal stability in the test period of time.

10.
Bioresour Technol ; 134: 73-80, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23500562

RESUMO

Inexpensive non-sulfided Ni-based catalysts were evaluated for hydrodeoxygenation (HDO) using guaiacol as model compound. SiO2-ZrO2 (SZ), a complex oxide synthesized by precipitation method with different ratio of Si/Zr, was impregnated with Ni(NO3)2·6H2O and calcined at 500°C. Conversion rates and product distribution for guaiacol HDO at 200-340°C were determined. Guaiacol conversion reached the maximum at 300°C in the presence of Ni/SZ-3. When HDO reaction was carried out with real lignin-derived phenolic compounds under the optimal conditions determined for guaiacol, the total yield of hydrocarbons was 62.81%. These hydrocarbons were comprised of cyclohexane, alkyl-substituted cyclohexane and alkyl-substituted benzene. They have high octane number, would be the most desirable components for fungible liquid transportation fuel.


Assuntos
Biotecnologia/métodos , Lignina/química , Níquel/química , Oxigênio/química , Fenóis/química , Dióxido de Silício/química , Zircônio/química , Catálise , Guaiacol/química , Hidrogenação , Porosidade , Espectroscopia de Infravermelho com Transformada de Fourier , Temperatura , Fatores de Tempo , Difração de Raios X
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