79 research outputs found
In-situ upgrading of Napier grass pyrolysis vapour over microporous and hierarchical mesoporous zeolites
This study presents in-situ upgrading of pyrolysis
vapour derived from Napier grass over microporous and
mesoporous ZSM-5 catalysts. It evaluates effect of process
variables such catalyst–biomass ratio and catalyst type in
a vertical fixed bed pyrolysis system at 600 °C, 50 °C/min
under 5 L/min nitrogen flow. Increasing catalyst–biomass
ratio during the catalytic process with microporous structure
reduced production of organic phase bio-oil by approximately
7.0 wt%. Using mesoporous catalyst promoted
nearly 4.0 wt% higher organic yield relative to microporous
catalyst, which translate to only about 3.0 wt% reduction
in organic phase compared to the yield of organic phase
from non-catalytic process. GC–MS analysis of bio-oil
organic phase revealed maximum degree of deoxygenation
of about 36.9% with microporous catalyst compared to
the mesoporous catalysts, which had between 39 and 43%.
Mesoporous catalysts promoted production olefins and
alkanes, normal phenol, monoaromatic hydrocarbons while
microporous catalyst favoured the production of alkenes
and polyaromatic hydrocarbons. There was no significant increase in the production of normal phenols over microporous catalyst due to its inability to transform the methoxyphenols and methoxy aromatics. This study demonstrated that upgrading of Napier grass pyrolysis vapour over mesoporous ZSM-5 produced bio-oil with improved physicochemical properties
TAF10 interacts with GATA1 transcription factor and controls mouse erythropoiesis
The ordered assembly of a functional pre-initiation complex (PIC), composed of general transcription factors (GTFs), is a prerequisite for the transcription of protein-coding genes by RNA polymerase II. TFIID, comprised of the TATA binding protein (TBP) and 13 TBP-associated factors (TAFs), is the GTF that is thought to recognize the promoter sequences allowing site-specific PIC assembly. Transcriptional cofactors, such as SAGA, are also necessary for tightly regulated transcription initiation. The contribution of the two TAF10-containing complexes (TFIID, SAGA) to erythropoiesis remains elusive. By ablating TAF10 specifically in erythroid cells in vivo we observed a differentiation block accompanied by deregulated GATA1 target genes, including Gata1 itself, suggesting functional crosstalk between GATA1 and TAF10. Additionally, we analyzed the composition of TFIID and SAGA complexes by mass spectrometry in mouse and human cells and found that their global integrity is maintained, with minor changes, during erythroid differentiation and development. In agreement with our functional data, we show that TAF10 interacts directly with GATA1 and that TAF10 is enriched on the GATA1 locus in human fetal erythroid cells. Thus, our findings demonstrate a crosstalk between canonical TFIID and SAGA complexes and cell-specific transcription activators during development and differentiation.status: publishe
- …