Water-gas shift reaction was applied to upcycle a waste-derived synthesis gas, which contains sulfur as an impurity. Pt/CeO2 was chosen as an appropriate catalyst through a metal and support ...screening study. The Pt/CeO2 catalyst showed stable catalytic activity without any deactivation for 100 h when the H2S was injected to 100 ppm, and still showed a sulfur tolerance even after 1,000 ppm of H2S was injected. In particular, the catalytic activity was fully regenerated when the H2S injection was stopped, regardless of the H2S concentration. The high sulfur tolerance and regeneration rate of Pt/CeO2 catalyst was due to the high oxygen storage capacity. This accelerates the redox mechanism of the water-gas shift reaction, and also helps the removal of the adsorbed sulfur on the Pt through the oxidation reaction with the mobile oxygen originated from the CeO2.
•Waste-derived syngas includes sulfur, which act as a poison to catalyst.•Active metal and support screening study was conducted.•Pt/CeO2 catalyst showed high sulfur tolerance and regeneration rate.•High oxygen storage capacity of the Pt/CeO2 was the key of superior performance.•Mobile oxygen attacked the adsorbed sulfur, resulting to the catalyst regeneration.
Waste to energy technology is attracting attention to overcome the upcoming environmental and energy issues. One of the key-steps is the water-gas shift (WGS) reaction, which can convert the ...waste-derived synthesis gas (H2 and CO) to pure hydrogen. Co–CeO2 catalysts were synthesized by the different methods to derive the optimal synthetic method and to investigate the effect of the preparation method on the physicochemical characteristics of Co–CeO2 catalysts in the high-temperature water-gas shift (HTS) reaction. The Co–CeO2 catalyst synthesized by the sol-gel method featured a strong metal to support interaction and the largest number of oxygen vacancies compared to other catalysts, which affects the catalytic activity. As a result, the Co–CeO2 catalyst synthesized by the sol-gel method exhibited the highest WGS activity among the prepared catalysts, even in severe conditions (high CO concentration: ~38% in dry basis and high gas hourly space velocity: 143,000 h−1).
The existence of tumorspheres (TSs) might confer treatment resistance to pineoblastoma (PB). The existence of PB TSs with cellular immortalization potential has not yet been reported. We developed a ...procedure for isolating TSs from recurrent PB (rPB) and tested whether their properties made them suitable for use as a patient-derived xenograft (PDX). Immunocytochemical staining, RT-PCR and quantitative real-time PCR showed that, among stemness proteins, CD133, musashi and podoplanin were expressed at elevated levels in rPB TSs, but nestin was not. rPB TSs cultured under neuro-glial differentiation conditions expressed TUBB3, but not GFAP, MBP or NeuN. Unlike glioblastoma TSs, rPB TSs showed no clear evidence of invasion in 3D invasion assay or increased expression of genes associated with epithelial-mesenchymal transition. An orthotopic xenograft showed that tumor xenografts replicated the histopathological features of the patient tumor and expressed similar genome profiles, as determined by short tandem repeat genotyping. These data demonstrate the isolation and the characterization of rPB TSs for the first time. Using an orthotopic xenograft, we showed that rPB TSs could replicate the patient tumor, demonstrating their potential as a PDX for precision medicine.
Purpose
Advancements in photodynamic diagnosis (PDD) and photodynamic therapy (PDT) as a standard care in cancer therapy have been limited. This study is aimed to investigate the clinical ...availability of 5-aminolevulinic acid (5-ALA)-based PDD and PDT in glioblastoma (GBM) patient-derived tumorspheres (TSs) and mouse orthotopic xenograft model.
Methods
PDT was performed using a 635 nm light-emitting diode (LED). Transcriptome profiles were obtained from microarray data. For knockdown of C5α, siRNA was transfected into tumor mesenchymal stem-like cells (tMSLCs). The invasiveness of TSs was quantified using collagen-based 3D invasion assays.
Results
Treatment with 1 mM 5 ALA induced distinct protoporphyrin IX (PpIX) fluorescence in GBM TSs, but not in non-tumor cells or tissues, including tMSLCs. These observations were negatively correlated with the expression levels of
FECH
, which catalyzes the conversion of accumulated PpIX to heme. Furthermore, the 5-ALA-treated GBM TSs were sensitive to PDT, thereby significantly decreasing cell viability and invasiveness. Notably, the effects of PDT were abolished by culturing TSs with tMSLC-conditioned media. Transcriptome analysis revealed diverse tMSLC-secreted chemokines, including C5α, and their correlations with the expression of stemness- or mesenchymal transition-associated genes. By adding or inhibiting C5α, we confirmed that acquired resistance to PDT was induced via tMSLC-secreted C5α.
Conclusions
Our results show substantial therapeutic effects of 5-ALA-based PDT on GBM TSs, suggesting C5α as a key molecule responsible for PDT resistance. These findings could trigger PDT as a standard clinical modality for the treatment of GBM.
The loading amount of Ba promoter in the 15 wt% Co/CeO2 catalyst system was varied from 0 wt% to 3 wt%, and the resulting catalysts were used for the high-temperature water-gas shift (HTS) reaction. ...The catalysts were prepared by the incipient wetness co-impregnation method and studied through various characterization techniques such as X-ray diffraction, Brunauer–Emmet–Teller measurements, CO–chemisorption, H2–temperature programmed reduction, X-ray photoelectron spectroscopy, and transmission electron microscopy. The doping of Ba as a promoter in the optimal amount (1–2 wt%) improves the reducibility of the catalyst and enhances its sintering resistance. However, the doping of an excessive amount (≥3 wt%) of the promoter lowers the reducibility of the catalyst, resulting in the instability of the active phase (Co0). Overall, the 1% BaCo/CeO2 catalyst exhibited the best performance even at a severe reaction condition (CO conc. = 38%, GHSV = 143,000 h−1) owing to the strong resistance to the sintering and high stability of the active phase.
Determination of the primary factors deciding the stability of the BaCo/CeO2 catalyst for water-gas shift reaction using waste-derived synthesis gas. Display omitted
•BaCo/CeO2 catalysts with various Ba loading were applied to the HTS reaction.•The feed gas of HTS reaction in this study is waste-derived synthesis gas.•Doping of Ba promoter enhanced sintering resistance and phase stability of Co0.•1–2 wt% was found to be the appropriate range for doping Ba promoter.•Among them, 1% BaCo/CeO2 showed the best catalytic performance.
Phenotypic heterogeneity of glioblastomas is a leading determinant of therapeutic resistance and treatment failure. However, functional assessment of the heterogeneity of glioblastomas is lacking. We ...developed a self-assembly-based assessment system that predicts inter/intracellular heterogeneity and phenotype associations, such as cell proliferation, invasiveness, drug responses, and gene expression profiles. Under physical constraints for cellular interactions, mixed populations of glioblastoma cells are sorted to form a segregated architecture, depending on their preference for binding to cells of the same phenotype. Cells distributed at the periphery exhibit a reduced temozolomide (TMZ) response and are associated with poor patient survival, whereas cells in the core of the aggregates exhibit a significant response to TMZ. Our results suggest that the multicellular self-assembly pattern is indicative of the intertumoral and intra-patient heterogeneity of glioblastomas, and is predictive of the therapeutic response.
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•Biofuel was produced by deoxygenation of oleic acid over Ni-Ce0.6Zr0.4O2.•The Ni-loaded Ce0.6Zr0.4O2 catalyst containing 20 wt% Ni loading was optimal.•20 wt% Ni-Ce0.6Zr0.4O2 ...exhibited 98.3% conversion and 33.9% selectivity.•Furthermore, this catalyst showed a superior oxygen removal rate (95.7%).•The biofuel produced via this catalyst showed a high calorific value (10213 cal/g).
Ni-loaded Ce0.6Zr0.4O2 catalysts were prepared by a co-precipitation method and subsequently employed in the deoxygenation of oleic acid under solvent-free conditions. Among the prepared catalysts, the 20 wt% Ni-Ce0.6Zr0.4O2 catalyst exhibited the highest catalytic activity, i.e., 98.3% oleic acid conversion, with 33.9% C9-C17 selectivity, and a 95.7% oxygen removal rate. The basic fuel properties of the obtained products were then examined to determine their potential for use in a diesel engine. The product produced using the 20 wt% Ni-Ce0.6Zr0.4O2 catalyst exhibited a particularly high calorific value (i.e., 10213 cal/g, similar to that of commercial diesel, i.e., 10220 cal/g), the lowest viscosity (25.2cP), and the lowest solidification temperature (−15 °C).
Enhanced catalytic performance is required to increase the efficiency of hydrogen production from waste-derived synthesis gas via the high-temperature water-gas shift reaction (HT-WGSR). Herein, the ...effects of barium, zirconium, and neodymium doping on the physico-chemical properties of a Ce/Cu/Al2O3 catalyst as well as its catalytic performance for HT-WGSR are investigated. Ce/Cu/Al2O3 catalysts with various additives (barium, zirconium, and neodymium) prepared via a sequential impregnation method have been characterized by using N2 adsorption-desorption isotherms, X-ray powder diffraction (XRPD), N2O-titration, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and hydrogen temperature-programmed reduction (H2-TPR). Advantageously, barium and zirconium addition enhance the HT-WGSR activity and stability of the Ce/Cu/Al2O3 catalyst, whereas neodymium doping has a negative effect. Regarding the correlation of catalytic performance with the characterization results, it was found that catalytic activity and stability strongly depended on their oxygen vacancy concentration and strong-metal to support interaction.
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•Ba, Zr, or Nd affects the catalytic performance of Ce/Cu/Al2O3 in WGS reaction.•Ba or Zr doping improves O vacancy and metal-support interaction of Ce/Cu/Al2O3.•Ba or Zr addition enhances the catalytic activity and stability of Ce/Cu/Al2O3.•Nd doping enhances reducibility but the catalytic performance is diminished.
A one-step reverse precipitation method has been developed to prepare nano-sized ceria (CeO2) support with controlled physicochemical properties for low temperature water-gas shift (LT-WGS) reaction. ...The nano-sized CeO2 support prepared by reverse precipitation method has a high Brunauer-Emmett-Teller (BET) surface area of 162.8 m2/g. To compare catalytic activity with that of CeO2 prepared by normal precipitation method, 5 wt% Cu was employed as the active metal, coupled to the CeO2 support. The catalytic activity of CeO2 supported Cu catalyst prepared by reverse precipitation method was evaluated for the first time in LT-WGS reaction. Notably, the CeO2 – R supported Cu catalyst, prepared by reverse precipitation method, showed higher CO conversion and turnover frequency (TOF) values than CeO2–N supported Cu catalyst prepared by normal precipitation method.
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•Nano-sized CeO2 is synthesized by a simple/one-step reverse precipitation method.•The titration sequence affected the physicochemical properties of the Cu/CeO2 catalysts.•Cu/CeO2–R prepared by reverse precipitation method exhibited the higher catalytic activity.•Cu/CeO2–R is suitable for large-scale applications.
Purpose
Glioblastoma (GBM) is the most aggressive type of brain tumor and has poor survival outcomes, even after a combination of surgery, radiotherapy, and chemotherapy. Temozolomide is the only ...agent that has been shown to be effective against GBM, suggesting that combination of temozolomide with other agents may be more effective. Niclosamide, an FDA approved anthelmintic agent, has shown anti-cancer effects against human colon, breast, prostate cancers as well as GBM. However, the efficacy of the combination of niclosamide with temozolomide against GBM tumorspheres (TSs) has not been determined. We hypothesized that the combined treatment could effectively suppress GBM TSs.
Methods
GBM TSs (TS15-88, GSC11) were treated with niclosamide and/or temozolomide. Combined effects of two drugs were evaluated by measuring viability, neurosphere formation, and 3D-invasion in collagen matrix. Transcriptional profiles of GBM TS were analyzed using RNA sequencing. In vivo anticancer efficacy of combined drugs was tested in a mouse orthotopic xenograft model.
Results
Combination treatment of niclosamide and temozolomide significantly inhibited the cell viability, stemness, and invasive properties of GBM TSs. This combined treatment significantly down-regulated the expression of epithelial mesenchymal transition-related markers, Zeb1,
N
-cadherin, and
β
-catenin. The combined treatment also significantly decreased tumor growth in orthotopic xenograft models.
Conclusion
The combination of niclosamide and temozolomide effectively decreased the stemness and invasive properties of GBM TSs, suggesting that this regimen may be therapeutically effective in treating patients with GBM.
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