Applications of 95Mo NMR. 5—substituent effects in the 95Mo and 13C NMR spectra of benzyltricarbonyl(η5‐cyclopentadienyl)molybdenum(II) derivatives

A systematic study has been made of the effects of substituent induced chemical shifts in [(η‐CH)(CO)Mo(CHCHR)] compounds. Both Mo and C NMR shifts in the aromatic ring are reported. The (η‐CH)(CO)MoCH group is a reasonably strong resonance donor (σ° = −0.21) and weak inductive donor (σ = −0.07). The molybdenum chemical shifts are extremely sensitive to the effects of distant substituents (range c. 40 ppm). Since the shift correlates well with substituent constants in this series, it is suggested that the chemical shift is controlled by the paramagnetic term for this spin 5/2 nucleus

Biocrude yield and productivity from the hydrothermal liquefaction of marine and freshwater green macroalgae

Six species of marine and freshwater green macroalgae were cultivated in outdoor tanks and subsequently converted to biocrude through hydrothermal liquefaction (HTL) in a batch reactor. The influence of the biochemical composition of biomass on biocrude yield and composition was assessed. The freshwater macroalgae Oedogonium afforded the highest biocrude yield of all six species at 26.2%, dry weight (dw). Derbesia (19.7% dw) produced the highest biocrude yield for the marine species followed by Ulva (18.7% dw). In contrast to significantly different yields across species, the biocrudes elemental profiles were remarkably similar with higher heating values of 33–34 MJ kg−1. Biocrude productivity was highest for marine Derbesia (2.4 g m−2 d−1) and Ulva (2.1 g m−2 d−1), and for freshwater Oedogonium (1.3 g m−2 d−1). These species were therefore identified as suitable feedstocks for scale-up and further HTL studies based on biocrude productivity, as a function of biomass productivity and the yield of biomass conversion to biocrude

Pre- and post-harvest treatment of macroalgae to improve the quality of feedstock for hydrothermal liquefaction

Three species of macroalgae were treated with the aim of reducing nitrogen, sulfur and ash within the biomass prior to hydrothermal processing. The treatments were the nutrient starvation of cultures and post-harvest washing of biomass in freshwater. Subsequently, hydrothermal liquefaction (HTL) of macroalgae was carried out in a batch reactor heated for 8 min with a maximum temperature of 345 °C. Nutrient starvation effectively reduced nitrogen and sulfur levels within the biomass, which led to a reduction in nitrogen by 51–59 wt.% and sulfur by 64–88 wt.% within the biocrude. The yield of biocrude was highest for Derbesia at 38.6–41.7 wt.% and Oedogonium at 35.6–38.8 wt.% when not starved, but was reduced by up to 19 wt.% when the biomass was starved. The washing of biomass consistently reduced the ash content for all species by 7–83 wt.%. The removal of ash affected neither the quality nor the quantity of biocrude produced. The two treatments demonstrate that macroalgal biomass can be effectively manipulated in the production process to modify the composition of the feedstock and, consequently, improve the quality of biocrude. Additionally, reducing the ash content of biomass minimizes its potential impact on HTL processing equipment

Neuronal sorting protein-related receptor sorLA/LR11 regulates processing of the amyloid precursor protein

sorLA (sorting protein-related receptor) is a type-1 membrane protein of unknown function that is expressed in neurons. Its homology to sorting receptors that shuttle between the plasma membrane, endosomes, and the Golgi suggests a related function in neuronal trafficking processes. Because expression of sorLA is reduced in the brain of patients with Alzheimer\u27s disease (AD), we tested involvement of this receptor in intracellular transport and processing of the amyloid precursor protein (APP) to the amyloid β-peptide (Aβ), the principal component of senile plaques. We demonstrate that sorLA interacts with APP in vitro and in living cells and that both proteins colocalize in endosomal and Golgi compartments. Overexpression of sorLA in neurons causes redistribution of APP to the Golgi and decreased processing to Aβ, whereas ablation of sorLA expression in knockout mice results in increased levels of Aβ in the brain similar to the situation in AD patients. Thus, sorLA acts as a sorting receptor that protects APP from processing into Aβ and thereby reduces the burden of amyloidogenic peptide formation. Consequently, reduced receptor expression in the human brain may increase Aβ production and plaque formation and promote spontaneous AD. © 2005 by The National Academy of Sciences of the USA