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1.
ACS Appl Mater Interfaces ; 14(40): 45516-45525, 2022 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-36173040

RESUMO

Developing catalysts to obtain high space time yield (STY) of gasoline-range hydrocarbons via Fischer-Tropsch synthesis (FTS) is a huge challenge due to the restriction of Anderson-Schulz-Flory distribution. Herein, a nitrogen doped biochar-based iron catalyst was synthesized by a one-step method using sugar cane bagasse as carbon precursor, which exhibited an excellent gasoline STY of 8.65 gC5-12 gFe-1 h-1, exceeding most reported catalysts. A strong positive relationship between the amount of pyrrolic N and long-chain hydrocarbons selectivity was displayed. The characterization results indicated that pyrrolic N configuration on anchor sites tuned effectively the dispersion of iron species and metal-support interaction as well as CO adsorption, improving the FTS performance.

2.
iScience ; 24(7): 102715, 2021 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-34258552

RESUMO

Exploiting new carbon supports with adjustable metal-support interaction and low price is of prime importance to realize the maximum active iron efficiency and industrial-scale application of Fe-based catalysts for Fischer-Tropsch synthesis (FTS). Herein, a simple, tunable, and scalable biochar support derived from the sugarcane bagasse was successfully prepared and was first used for FTS. The metal-support interaction was precisely controlled by functional groups of biosugarcane-based carbon material and different iron species sizes. All catalysts synthesized displayed high activities, and the iron-time-yield of Fe4/C bio even reached 1,198.9 µmol gFe -1 s-1. This performance was due to the unique structure and characteristics of the biosugarcane-based carbon support, which possessed abundant C-O, C=O (η1(O) and η2(C, O)) functional groups, thus endowing the moderate metal-support interaction, high dispersion of active iron species, more active ε-Fe2C phase, and, most importantly, a high proportion of FexC/Fesurf, facilitating the maximum iron efficiency and intrinsic activity of the catalyst.

3.
RSC Adv ; 10(18): 10723-10730, 2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-35492905

RESUMO

Although numerous studies have been conducted in the field of converting syngas to value-added fuels, selectively converting syngas to gasoline-range hydrocarbons (C5-12 hydrocarbons) remains a big challenge. Alkali metal (namely, K, Na and Li)-modified Fe@C core-shell catalysts were synthesized by a one-step hydrothermal method for Fischer-Tropsch synthesis. An optimized selectivity of 56% for the C5-12 hydrocarbons with a higher CO conversion of about 95% was obtained for the FeNa2.0@C catalyst compared to that for other alkali metal-modified Fe@C catalysts. According to the characterization results, the incorporation of alkali metals into Fe@C enhanced the conversion of FeCO3 to Fe3O4, which promoted the formation of the FTS active phase iron carbides. In particular, the strongest interaction of Fe-alkali metal and the highest amount of surface carbon layers were observed after adding an Na promoter into Fe@C in contrast to that observed for K and Li promoters, which strengthened the synergistic effect of Fe-Na metals and the spatial confinement of the core-shell structure, further improving the C5-12 hydrocarbon selectivity.

4.
Oncol Res ; 21(2): 111-20, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24406047

RESUMO

Glioblastoma (GBM) is the most common primary brain tumor and the leading cause of tumor-related death in the central nervous system. To date, the mechanisms of GBM genesis remain elusive. Forkhead box protein C2 (FOXC2) is a transcription factor that has been reported in many cancers, but its function in GBM tumorigenesis is not clearly elucidated. This study found that FOXC2 was overexpressed in GBM cell lines and GBM tissues. The proliferation and invasive potential of GBM cells were significantly increased by ectopic expression of FOXC2 but significantly decreased by RNA interference targeting FOXC2. EGFR expression was modulated by FOXC2 both in mRNA and protein levels. EGFR inhibition by siRNA reversed the FOXC2-induced proliferation and invasion. These findings suggested that FOXC2 expressed in GBM has a function in GBM cell proliferation and invasion and may be partly associated with the EGFR overexpression.


Assuntos
Neoplasias Encefálicas/metabolismo , Neoplasias Encefálicas/patologia , Fatores de Transcrição Forkhead/biossíntese , Glioblastoma/metabolismo , Glioblastoma/patologia , Neoplasias Encefálicas/genética , Processos de Crescimento Celular/fisiologia , Linhagem Celular Tumoral , Movimento Celular/fisiologia , Receptores ErbB/metabolismo , Fatores de Transcrição Forkhead/genética , Glioblastoma/genética , Humanos , Invasividade Neoplásica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo
5.
Oncol Lett ; 6(3): 781-784, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24137410

RESUMO

The aim of the present study was to determine the efficacy of microsurgery treatment for parasagittal meningioma in the central gyrus region. A microsurgical technique was used to treat 26 patients with large parasagittal meningioma in the central gyrus region. The Rolandic and draining veins and the peritumoral normal brain tissue were retained, and the associated sagittal sinus was appropriately protected. A Simpson grade I, II or III resection was performed in 8 (30.8%), 12 (46.2%) and 6 (23.1%) patients, respectively, with no post-operative mortalities. Following treatment, 9 patients exhibited hemiparalysis. No tumor recurrence was found in 21 patients during the follow-up examination. The treatment protocol described in the current study included sufficient pre-operative imaging evaluations, a skilled microsurgical technique, improved protection of the Rolandic vein and treatment of the sagittal sinus, and was found to significantly increase the total tumor removal rate and decrease post-operative recurrence.

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