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1.
Environ Sci Pollut Res Int ; 31(24): 35069-35082, 2024 May.
Article in English | MEDLINE | ID: mdl-38714619

ABSTRACT

The increasing concentration of CO2 and CH4 in the environment is a global concern. Tri-reforming of methane (TRM) is a promising route for the conversion of these two greenhouse gases to more valuable synthesis gas with an H2/CO ratio of 1.5-2. In this study, a series of Zr-MOF synthesized via the solvothermal method and impregnation technique was used to synthesize the nickel impregnated on MOF-derived ZrO2 catalyst. The catalyst was characterized by various methods, including N2-porosimetry, X-ray diffraction (XRD), temperature programmed reduction (TPR), CO2-temperature programmed desorption (CO2-TPD), thermo-gravimetric analysis (TGA), chemisorption, field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). Characterization results confirmed the formation of the Zr-MOF and nickel metal dispersed on MOF-derived ZrO2. Further, the tri-reforming activity of the catalyst developed was evaluated in a downflow-packed bed reactor. The various catalysts were screened for TRM activity at different temperatures (600-850 °C). Results demonstrated that TRM was highly favorable over the NZ-1000 catalyst due to its desirable physicochemical properties, including nickel metal surface area (2.3 m2/gcat-1), metal dispersion (7.1%), and nickel metal reducibility (45%), respectively. Over the NZ-1000 catalyst, an optimum H2/CO ratio of ~ 1.6-2 was achieved at 750 °C, and it was stable for a longer period of time.


Subject(s)
Methane , Nickel , Zirconium , Methane/chemistry , Catalysis , Nickel/chemistry , Zirconium/chemistry , Metal-Organic Frameworks/chemistry , Carbon Dioxide/chemistry , X-Ray Diffraction
2.
Proc Natl Acad Sci U S A ; 117(35): 21527-21535, 2020 09 01.
Article in English | MEDLINE | ID: mdl-32817520

ABSTRACT

Given the known neuroreparative actions of IL-33 in experimental models of central nervous system (CNS) injury, we predicted that compounds which induce IL-33 are likely to promote remyelination. We found anacardic acid as a candidate molecule to serve as a therapeutic agent to promote remyelination. Addition of anacardic acid to cultured oligodendrocyte precursor cells (OPCs) rapidly increased expression of myelin genes and myelin proteins, suggesting a direct induction of genes involved in myelination by anacardic acid. Also, when added to OPCs, anacardic acid resulted in the induction of IL-33. In vivo, treatment of with anacardic acid in doses which ranged from 0.025 mg/kg to 2.5 mg/kg, improved pathologic scores in experimental allergic encephalitis (EAE) and in the cuprizone model of demyelination/remyelination. Electron microscopic studies performed in mice fed with cuprizone and treated with anacardic acid showed lower g-ratio scores when compared to controls, suggesting increased remyelination of axons. In EAE, improvement in paralytic scores was seen when the drug was given prior to or following the onset of paralytic signs. In EAE and in the cuprizone model, areas of myelin loss, which are likely to remyelinate, was associated with a greater recruitment of IL-33-expressing OPCs in mice which received anacardic acid when compared to controls.


Subject(s)
Anacardic Acids/pharmacology , Interleukin-33/biosynthesis , Remyelination/drug effects , Animals , Central Nervous System/drug effects , Central Nervous System/metabolism , Demyelinating Diseases/drug therapy , Demyelinating Diseases/metabolism , Female , Interleukin-33/metabolism , Male , Mice , Mice, Inbred C57BL , Myelin Basic Protein/metabolism , Myelin Proteins/metabolism , Myelin Sheath/metabolism , Oligodendrocyte Precursor Cells/drug effects , Oligodendrocyte Precursor Cells/metabolism , Oligodendroglia/metabolism , Remyelination/physiology , Stem Cells/metabolism
3.
Sci Rep ; 6: 34464, 2016 10 05.
Article in English | MEDLINE | ID: mdl-27703261

ABSTRACT

Calotropis procera is a medicinal plant of immense importance due to its pharmaceutical active components, especially cardiac glycosides (CG). As genomic resources for this plant are limited, the genes involved in CG biosynthetic pathway remain largely unknown till date. Our study on stage and tissue specific metabolite accumulation showed that CG's were maximally accumulated in stems of 3 month old seedlings. De novo transcriptome sequencing of same was done using high throughput Illumina HiSeq platform generating 44074 unigenes with average mean length of 1785 base pair. Around 66.6% of unigenes were annotated by using various public databases and 5324 unigenes showed significant match in the KEGG database involved in 133 different pathways of plant metabolism. Further KEGG analysis resulted in identification of 336 unigenes involved in cardenolide biosynthesis. Tissue specific expression analysis of 30 putative transcripts involved in terpenoid, steroid and cardenolide pathways showed a positive correlation between metabolite and transcript accumulation. Wound stress elevated CG levels as well the levels of the putative transcripts involved in its biosynthetic pathways. This result further validated the involvement of identified transcripts in CGs biosynthesis. The identified transcripts will lay a substantial foundation for further research on metabolic engineering and regulation of cardiac glycosides biosynthesis pathway genes.


Subject(s)
Calotropis , Cardiac Glycosides , Genes, Plant , Metabolome/physiology , Transcriptome/physiology , Calotropis/genetics , Calotropis/metabolism , Cardiac Glycosides/biosynthesis , Cardiac Glycosides/genetics
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