Search Results (4)

The cultivation of oil palm (Elaeis guineensis Jaq.) and its production generate large quantities of solid wastes annually. Current strategies adopted for tackling oil palm trunks (OPTs), which account for a significant proportion of oil palm waste (OPW), are considered expensive, inefficient, and unsustainable. Analysts posit this scenario could exacerbate efforts to not only effectively dispose and manage OPT but also lower the carbon footprint of the Oleo industry. Hence, immediate and urgent attention is needed to address the challenges posed by current strategies. Biomass torrefaction has recently gained traction as a practical approach for OPW valorisation into biochar. Therefore, this study seeks to (i) characterise the physicochemical characteristics of OPT through ultimate, proximate, and calorific analyses and (ii) examine the thermochemical, degradation, and temperature profile characteristics of OPT as potential torrefaction feedstock using thermal gravimetric analysis (TGA). TGA was performed at torrefaction temperatures; T_t = 200–300 °C (Δ25 °C stepwise increase) under isothermal/non-isothermal conditions of nitrogen (N₂) flowrate 100 mL/min), heating rate 20 °C/min, and 30-min residence time. The results showed that OPT contains high carbon (>45 wt.%), hydrogen (>6 wt.%), volatile matter (>80 wt.%) but low ash (2 wt.%), fixed carbon (5 wt.%), and moisture (10 wt.%) contents. OPT experienced 14.55–60.82 wt.% weight loss during TGA degradation from 200 to 300 °C. The increase in temperature resulted in a corresponding rise in OPT biochar yields ranging from 85.45 to 39.18 wt.% and higher heating values of 20–23 MJ/kg. The DTG plots showed that the TGA torrefaction process occurred in two stages, (i) 100 °C and (ii) >100 to the selected T_t, which could be ascribed to the drying and devolatilization/depolymerisation of OPT, respectively. Overall, this study demonstrated that OPT is a potentially practical feedstock for torrefaction into biochar. Full article

Handroanthus and Tabebuia are known for their ornamental and medicinal value, which are attributed to metabolites. However, the mechanisms underlying the synthesis of these metabolites are poorly understood. In this study, the expression levels of secondary metabolites and the mechanism of flavonoid biosynthesis in the bark and leaves of Handroanthus chrysantha (Jaq.) were examined using transcriptomic and metabolomic techniques. Metabolic analysis identified several differentially accumulated metabolites (DAMs), most of which were flavonoids, isoprenoids, and sterols. Additionally, 30 flavonoids were identified in the bark and leaves of H. chrysantha. Transcriptomic analysis identified 69 genes involved in flavonoid biosynthesis, among which 49 were significantly different between the bark and leaves. qRT-PCR analysis of eight genes involved in flavonoid biosynthesis showed that the expression patterns of the genes were consistent with the transcriptome sequencing data. Integrative transcriptomic and metabolomic analysis showed that 20 differentially expressed genes (DEGs) associated with flavonoid biosynthesis were strongly correlated with seven DAMs, confirming the involvement of the DEGs in flavonoid biosynthesis. These findings considerably contribute to the understanding of the biosynthesis of secondary metabolites in H. chrysantha and serve as a reference for further pharmacological studies. Full article

Glycoprotein (GP) VI is the major platelet collagen receptor and a promising anti-thrombotic target. This was first demonstrated in mice using the rat monoclonal antibody JAQ1, which completely blocks the Collagen-Related Peptide (CRP)-binding site on mouse GPVI and efficiently inhibits mouse platelet adhesion, activation and aggregation on collagen. Here, we show for the first time that JAQ1 cross-reacts with human GPVI (huGPVI), but not with GPVI in other tested species, including rat, rabbit, guinea pig, swine, and dog. We further demonstrate that JAQ1 differently modulates mouse and human GPVI function. Similar to its effects on mouse GPVI (mGPVI), JAQ1 inhibits CRP-induced activation in human platelets, whereas, in stark contrast to mouse GPVI, it does not inhibit the adhesion, activation or aggregate formation of human platelets on collagen, but causes instead an increased response. This effect was also seen with platelets from newly generated human GPVI knockin mice (hGP6^tg/tg). These results indicate that the binding of JAQ1 to a structurally conserved epitope in GPVI differently affects its function in human and mouse platelets. Full article

Platelet collagen interactions at sites of vascular injuries predominantly involve glycoprotein VI (GPVI) and the integrin α2β1. Both proteins are primarily expressed on platelets and megakaryocytes whereas GPVI expression is also shown on endothelial and integrin α2β1 expression on epithelial cells. We recently showed that depletion of GPVI improves stroke outcome without increasing the risk of cerebral hemorrhage. Genetic variants associated with higher platelet surface integrin α2 (ITGA2) receptor levels have frequently been found to correlate with an increased risk of ischemic stroke in patients. However until now, no preclinical stroke study has addressed whether platelet integrin α2β1 contributes to the pathophysiology of ischemia/reperfusion (I/R) injury. Focal cerebral ischemia was induced in C57BL/6 and Itga2^−/− mice by a 60 min transient middle cerebral artery occlusion (tMCAO). Additionally, wild-type animals were pretreated with anti-GPVI antibody (JAQ1) or Fab fragments of a function blocking antibody against integrin α2β1 (LEN/B). In anti-GPVI treated animals, intravenous (IV) recombinant tissue plasminogen activator (rt-PA) treatment was applied immediately prior to reperfusion. Stroke outcome, including infarct size and neurological scoring was determined on day 1 after tMCAO. We demonstrate that targeting the integrin α2β1 (pharmacologic; genetic) did neither reduce stroke size nor improve functional outcome on day 1 after tMCAO. In contrast, depletion of platelet GPVI prior to stroke was safe and effective, even when combined with rt-PA treatment. Our results underscore that GPVI, but not ITGA2, is a promising and safe target in the setting of ischemic stroke. Full article