Hierarchical macroporous-mesoporous SBA-15 sulfonic acid catalysts for biodiesel synthesis

Hierarchical macroporous-mesoporous SBA-15 silicas have been synthesised via dual-templating routes employing liquid crystalline surfactants and polystyrene beads. These offer high surface areas and well-defined, interconnecting macro- and mesopore networks with respective narrow size distributions around 300 nm and 3-5 nm for polystyrene:tetraethoxysilane ratios ≥2:1. Subsequent functionalisation with propylsulfonic acid yields the first organized, macro-mesoporous solid acid catalyst. The enhanced mass transport properties of these new bi-modal solid acid architectures confer significant rate enhancements in the transesterification of bulky glyceryl trioctanoate, and esterification of long chain palmitic acid, over pure mesoporous analogues. This paves the way to the wider application of hierarchical catalysts in biofuel synthesis and biomass conversion. © 2010 The Royal Society of Chemistry.

Pore-expanded SBA-15 sulfonic acid silicas for biodiesel synthesis

Here we present the first application of pore-expanded SBA-15 in heterogeneous catalysis. Pore expansion over the range 6-14 nm confers a striking activity enhancement towards fatty acid methyl ester (FAME) synthesis from triglycerides (TAG), and free fatty acid (FFA), attributed to improved mass transport and acid site accessibility.

Efficacy of memantine for agitation in Alzheimer's dementia:a randomised double-blind placebo controlled trial

Background - Agitation in Alzheimer’s disease (AD) is common and associated with poor patient life-quality and carer distress. The best evidence-based pharmacological treatments are antipsychotics which have limited benefits with increased morbidity and mortality. There are no memantine trials in clinically significant agitation but post-hoc analyses in other populations found reduced agitation. We tested the primary hypothesis, memantine is superior to placebo for clinically significant agitation, in patients with moderate-to-severe AD. Methods and Findings - We recruited 153 participants with AD and clinically significant agitation from care-homes or hospitals for a double-blind randomised-controlled trial and 149 people started the trial of memantine versus placebo. The primary outcome was 6 weeks mixed model autoregressive analysis of Cohen-Mansfield Agitation Inventory (CMAI). Secondary outcomes were: 12 weeks CMAI; 6 and 12 weeks Neuropsychiatric symptoms (NPI), Clinical Global Impression Change (CGI-C), Standardised Mini Mental State Examination, Severe Impairment Battery. Using a mixed effects model we found no significant differences in the primary outcome, 6 weeks CMAI, between memantine and placebo (memantine lower -3.0; -8.3 to 2.2, p = 0.26); or 12 weeks CMAI; or CGI-C or adverse events at 6 or 12 weeks. NPI mean difference favoured memantine at weeks 6 (-6.9; -12.2 to -1.6; p = 0.012) and 12 (-9.6; -15.0 to -4.3 p = 0.0005). Memantine was significantly better than placebo for cognition. The main study limitation is that it still remains to be determined whether memantine has a role in milder agitation in AD. Conclusions - Memantine did not improve significant agitation in people with in moderate-to-severe AD. Future studies are urgently needed to test other pharmacological candidates in this group and memantine for neuropsychiatric symptoms.

The dynamics of global sourcing : perspectives and practices:6th global sourcing workshop 2012, Courchevel, France, March 12-15, 2012, revised selected papers

This edited book is intended for use by students, academics and practitioners who take interest in the outsourcing and offshoring of information technology and business services and processes. The book offers a review of the key topics in outsourcing and offshoring, populated with practical frameworks that serve as a tool kit for practitioners, academics and students. The range of topics covered in this book is wide and diverse, and represents both client and supplier perspectives on sourcing of global services. Various aspects related to the decision making process (e.g., asset transfer), learning mechanisms and organizational practices for managing outsourcing relationships are discussed in great depth. Contemporary sourcing models, including cloud services, are examined. Client dependency on the outsourcing provider, and social aspects, such as identity, are discussed in detail. Furthermore, resistance in outsourcing and failures are investigated to derive lessons as to how to avoid them and improve efficiency in outsourcing. Topics discussed in this book combine theoretical and practical insights regarding challenges that both clients and vendors face. Case studies from client and vendor organizations are used extensively throughout the book. Last but not least, the book examines current and future trends in outsourcing and offshoring, placing particular attention on the centrality of innovation in sourcing arrangements, and how innovation can be realized in outsourcing. The book is based on a vast empirical base brought together through years of extensive research by leading researchers in information systems, strategic management and operations.

Downregulation of ubiquitin-dependent proteolysis by eicosapentaenoic acid in acute starvation

A number of acute wasting conditions are associated with an upregulation of the ubiquitin-proteasome system in skeletal muscle. Eicosapentaenoic acid (EPA) is effective in attenuating the increased protein catabolism in muscle in cancer cachexia, possibly due to inhibition of 15-hydroxyeicosatetraenoic acid (15-HETE) formation. To determine if a similar pathway is involved in other catabolic conditions, the effect of EPA on muscle protein degradation and activation of the ubiquitin-proteasome pathway has been determined during acute fasting in mice. When compared with a vehicle control group (olive oil) there was a significant decrease in proteolysis of the soleus muscles of mice treated with EPA after starvation for 24 h, together with an attenuation of the proteasome 'chymotryptic-like' enzyme activity and the induction of the expression of the 20S proteasome α-subunits, the 19S regulator and p42, an ATPase subunit of the 19S regulator in gastrocnemius muscle, and the ubiquitin-conjugating enzyme E214k. The effect was not shown with the related (n-3) fatty acid docosahexaenoic acid (DHA) or with linoleic acid. However, 2,3,5trimethyl-6-(3-pyridylmethyl)1,4-benzoquinone (CV-6504), an inhibitor of 5-, 12- and 15-lipoxygenases also attenuated muscle protein catabolism, proteasome 'chymotryptic-like' enzyme activity and expression of proteasome 20S α-subunits in soleus muscles from acute fasted mice. These results suggest that protein catabolism in starvation and cancer cachexia is mediated through a common pathway, which is inhibited by EPA and is likely to involve a lipoxygenase metabolite as a signal transducer. © 2001 Academic Press.

Tunable KIT-6 mesoporous sulfonic acid catalysts for fatty acid esterification

We report the first catalytic application of pore-expanded KIT-6 propylsulfonic acid (PrSO H) silicas, in fatty acid esterification with methanol under mild conditions. As-synthesized PrSO H-KIT-6 exhibits a 40 and 70% enhancement in turnover frequency (TOF) toward propanoic and hexanoic acid esterification, respectively, over a PrSO H-SBA-15 analogue of similar 5 nm pore diameter, reflecting the improved mesopore interconnectivity of KIT-6 over SBA-15. However, pore accessibility becomes rate-limiting in the esterification of longer chain lauric and palmitic acids over both solid acid catalysts. This problem can be overcome via hydrothermal aging protocols which permit expansion of the KIT-6 mesopore to 7 nm, thereby doubling the TOF for lauric and palmitic acid esterification over that achievable with PrSO H-SBA-15. © 2012 American Chemical Society.

Octyl co-grafted PrSO3H/SBA-15:tunable hydrophobic solid acid catalysts for acetic acid esterification

Propylsulfonic acid (PrSO3H) derivatised solid acid catalysts have been prepared by post modification of mesoporous SBA-15 silica with mercaptopropyltrimethoxysilane (MPTMS), with the impact of co-derivatisation with octyltrimethoxysilane (OTMS) groups to impart hydrophobicity to the catalyst investigated. Turn over frequencies (TOF) for acetic acid esterification with methanol increase with PrSO3H surface coverage across both families suggesting a cooperative effect of adjacent acid sites at high acid site densities. Esterification activity is further promoted upon co-functionalisation with hydrophobic octyl chains, with inverse gas chromatography (iGC) measurements indicating increased activity correlates with decreased surface polarity or increased hydrophobicity.