An economically viable ionic liquid for the fractionation of lignocellulosic biomass

Cost-effective fractionation (pretreatment) of lignocellulosic biomass is necessary to enable its large-scale use as a source of liquid fuels, bio-based materials and bio-derived chemicals. While a number of ionic liquids (ILs) have proven capable of highly effective pretreatment, their high cost presents a barrier to commercial viability. In this study, we investigate in detail the application of the low-cost (ca. $1 kg−1) ionic liquid triethylammonium hydrogen sulfate for the fractionation of the grass Miscanthus x giganteus into a cellulose rich pulp, a lignin and a distillate. We found that up to 85% of the lignin and up to 100% of the hemicellulose were solubilized into the IL solution. The hemicellulose dissolved mainly in monomeric form, and pentoses were partially converted into furfural. Up to 77% of the glucose contained in the biomass could be released by enzymatic saccharification of the pulp. The IL was successfully recovered and reused four times. A 99% IL recovery was achieved each time. Effective lignin removal and high saccharification yields were maintained during recycling, representing the first demonstration that repeated IL use is feasible due to the self-cleaning properties of the non-distillable solvent. We further demonstrate that furfural and acetic acid can be separated quantitatively from the non-volatile IL by simple distillation, providing an easily recoverable, valuable co-product stream, while IL degradation products were not detected. We further include detailed mass balances for glucose, hemicellulose and lignin, and a preliminary techno-economic estimate for the fractionation process. This is the first demonstration of an efficient and repeated lignocellulose fractionation with a truly low-cost IL, and opens a path to an economically viable IL-based pretreatment process

Does modafinil enhance activity of patients with myotonic dystrophy?: A double-blind placebo-controlled crossover study

We performed a double-blind placebo-controlled crossover study in 13 patients with myotonic dystrophy to address the question whether modafinil, known to improve hypersomnolence in myotonic dystrophy, may improve levels of activity as well. We used the Epworth Sleepiness Scale as a measure of hypersomnolence and a structured interview of the patient and the partner or housemate as a measure of activity. We additionally used a restricted form of the RAND-36 to relate a possible improvement of activity to perceived general health. We confirmed earlier positive findings of modafinil regarding reduced somnolence (p = 0.015), but no significant effects were seen regarding activity levels (p = 0.2 for patients’ self-reports and 0.5 for partners’ reports)

Fractionation by sequential antisolvent precipitation of grass, softwood, and hardwood lignins isolated using low-cost ionic liquids and water

In this study, fractionation by sequential antisolvent precipitation was applied to ionoSolv lignins for the first time. Pretreatment with the aqueous low-cost protic ionic liquid N,N-dimethylbutylammonium hydrogen sulfate ([DMBA][HSO4], 80 wt % in water) was applied to Miscanthus (herbaceous), willow (hardwood), and pine (softwood) to extract lignin. Then, lignin was sequentially precipitated by the addition of water as an antisolvent. Fractionation appeared to be controlled by the molecular weight of lignin polymers. Fractions isolated with minimal water volumes were shown to have high molecular weight, polydispersity, thermal stability, and Tg (178 °C). Later precipitates were more monodisperse and had high phenolic and total hydroxyl content and lower thermal stability and Tg (136 °C). Addition of 1 g of water per gram of dry IL was able to precipitate up to 90 wt % of lignin. Fractional precipitation represents a novel lignin isolation technique that can be performed as part of the lignin recovery procedure enabling a high degree of control of lignin properties. The effect of the fractionation on lignin structural, chemical, and thermal properties was thoroughly examined by two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance, gel permeation chromatography, thermogravimetric analysis, and differential scanning calorimetry and compared to the unfractionated lignin precipitate obtained by addition of an excess of water

Microglial activation, white matter tract damage, and disability in MS

ObjectiveTo investigate the relationship of in vivo microglial activation to clinical and MRI parameters in MS.MethodsPatients with secondary progressive MS (n = 10) or relapsing-remitting MS (n = 10) and age-matched healthy controls (n = 17) were studied. Microglial activation was measured using PET and radioligand [C-11](R)-PK11195. Clinical assessment and structural and quantitative MRI including diffusion tensor imaging (DTI) were performed for comparison.Results[C-11](R)-PK11195 binding was significantly higher in the normal-appearing white matter (NAWM) of patients with secondary progressive vs relapsing MS and healthy controls, in the thalami of patients with secondary progressive MS vs controls, and in the perilesional area among the progressive compared with relapsing patients. Higher binding in the NAWM was associated with higher clinical disability and reduced white matter (WM) structural integrity, as shown by lower fractional anisotropy, higher mean diffusivity, and increased WM lesion load. Increasing age contributed to higher microglial activation in the NAWM among patients with MS but not in healthy controls.ConclusionsPET can be used to quantitate microglial activation, which associates with MS progression. This study demonstrates that increased microglial activity in the NAWM correlates closely with impaired WM structural integrity and thus offers one rational pathologic correlate to diffusion tensor imaging (DTI) parameters

Rac1 Is Required for Pathogenicity and Chm1-Dependent Conidiogenesis in Rice Fungal Pathogen Magnaporthe grisea

Rac1 is a small GTPase involved in actin cytoskeleton organization and polarized cell growth in many organisms. In this study, we investigate the biological function of MgRac1, a Rac1 homolog in Magnaporthe grisea. The Mgrac1 deletion mutants are defective in conidial production. Among the few conidia generated, they are malformed and defective in appressorial formation and consequently lose pathogenicity. Genetic complementation with native MgRac1 fully recovers all these defective phenotypes. Consistently, expression of a dominant negative allele of MgRac1 exhibits the same defect as the deletion mutants, while expression of a constitutively active allele of MgRac1 can induce abnormally large conidia with defects in infection-related growth. Furthermore, we show the interactions between MgRac1 and its effectors, including the PAK kinase Chm1 and NADPH oxidases (Nox1 and Nox2), by the yeast two-hybrid assay. While the Nox proteins are important for pathogenicity, the MgRac1-Chm1 interaction is responsible for conidiogenesis. A constitutively active chm1 mutant, in which the Rac1-binding PBD domain is removed, fully restores conidiation of the Mgrac1 deletion mutants, but these conidia do not develop appressoria normally and are not pathogenic to rice plants. Our data suggest that the MgRac1-Chm1 pathway is responsible for conidiogenesis, but additional pathways, including the Nox pathway, are necessary for appressorial formation and pathogenicity

Long term survival after coronary endarterectomy in patients undergoing combined coronary and valvular surgery – a fifteen year experience

<p>Abstract</p> <p>Background</p> <p>Coronary Endarterectomy (CE) in patients undergoing coronary artery bypass graft (CABG) surgery has been shown to be beneficial in those with diffuse coronary artery disease. There are no published data on its role and benefit in patients undergoing more complex operations. We present our experience with CE in patients undergoing valve surgery with concomitant CABG.</p> <p>Materials and methods</p> <p>Between 1989 and 2003, 237 patients underwent CABG with valve surgery under a single surgeon at our institution. Of these, 41 patients needed CE. Data was retrospectively obtained from hospital records and database. Further follow-up was obtained by telephone interview. All variables were analyzed by univariate analysis for significant factors relating to hospital mortality. Morbidity and long term survival was also studied. There were 29 males and 12 females with a mean age of 67.4 ± 8.1 and body mass index of 26.3 ± 3.3. Their mean euroscore was 7.6 ± 3.2 and the log euro score was 12.2 ± 16.1.</p> <p>Results</p> <p>Thirty-two patients were discharged from the intensive therapy unit within 48 hours after surgery. Average hospital stay was 12.7 ± 10.43 days. Thirty day mortality was 9.8%. Six late deaths occurred during the 14 year follow up. Ten year survival was 57.2% (95% CL 37.8%–86.6%). Three of the survivors had Class II symptoms, with one requiring nitrates. None required further percutaneous or surgical intervention. We compared the result with the available mortality figure from the SCTS database.</p> <p>Conclusion</p> <p>Compared to the SCTS database for these patients, we have observed that CE does not increase the mortality in combined procedures. By accomplishing revascularization in areas deemed ungraftable, we have shown an added survival benefit in this group of patients.</p