Probing the mechanism of benzaldehyde reduction to chiral hydrobenzoin on the CNT surface under near-UV light irradiation

Metal-free CNTs exhibit high activity (conversion rate 99.6%, 6 h) towards the synthesis of chiral hydrobenzoin from benzaldehyde under near-UV light irradiation (320–400 nm). The CNT structure before and after the reaction, the interaction between the molecule and the CNT surface, the intermediate products, the substitution effect and the influence of light on the reaction were examined using various techniques. A photo-excited conduction electron transfer (PECET) mechanism for the photocatalytic reduction using CNTs has been proposed. This finding provides a green photocatalytic route for the production of hydrobenzoin and highlights a potential photocatalytic application of CNTs.

Surface-mediated selective photocatalytic aerobic oxidation reactions on TiO2 nanofibres

N-doped TiO2 nanofibres were observed to possess lower aerobic oxidation activity than undoped TiO2 nanofibres in the selective photocatalytic aerobic oxidation of enzylamine and 4-methoxybenzyl alcohol. This was attributed to the reduction free energy of O2 adsorption in the vicinity of nitrogen dopant sites, as indicated by density functional theory (DFT) calculations when three-coordinated oxygen atoms are substituted by nitrogen atoms. It was found that the activity recovered following a controlled calcination of the N-doped NFs in air. The dependence of the conversion of benzylamine and 4-methoxybenzyl alcohol on the intensity of light irradiation confirmed that these reactions were driven by light. Action spectra showed that the two oxidation reactions are responsive to light from the UV region through to the visible light irradiation range. The extended light absorption wavelength range in these systems compared to pure TiO2 materials was found to result from the formation of surface complex species following adsorption of reactants onto the catalysts' surface, evidenced by the in situ IR experiment. Both catalytic and in situ IR results reveal that benzaldehyde is the intermediate in the aerobic oxidation of benzylamine to N-benzylidenebenzylamine process.

Heterojunctions between amorphous and crystalline niobium oxide with enhanced photoactivity for selective aerobic oxidation of benzylamine to imine under visible light

The formation of heterojunctions between two crystals with different band gap structures, acting as a tunnel for the unidirectional transfer of photo-generated charges, is an efficient strategy to enhance photocatalytic performance in semiconductor photocatalysts. The heterojunctions may also promote the photoactivity in the visible-light-response of any surface complex catalysts by influencing the transfer of photo-generated electrons. Herein, Nb2O5 microfibers, with a high surface area of interfaces between an amorphous phase and crystalline phase, were designed and synthesised by the calcination of hydrogen-form niobate while controlling the crystallization The photoactivity of these microfibers towards selective aerobic oxidation reactions was investigated. As predicted, the Nb2O5 microfibres containing heterojunctions exhibited the highest photoactivity. This could be due to the band gap difference between the amorphous phase and the crystalline phase, which shortened the charge mobile distance and improved the efficiency.

Inflammatory meditated mechanisms of cisplatin resistance in non-small cell lung cancer

The majority of non-small cell lung cancer (NSCLC) patients present with advanced stage disease, where chemotherapy is usually the most common treatment option. While somewhat effective, patients treated with cisplatin-based chemotherapy will eventually develop resistance. Multiple pathways have been implicated in chemo-resistance, however the critical underlying mechanisms have yet to be elucidated. The aim of this project is to determine the role of inflammatory mediators in cisplatin resistance.

Advances in mesoporous molecular sieve MCM-41

The discovery of mesoporous molecular sieves, MCM-41, which possesses a regular hexagonal array of uniform pore openings, aroused a worldwide resurgence in this field. This is not only because it has brought about a series of novel mesoporous materials with various compositions which may find applications in catalysis, adsorption, and guest-host chemistry, but also it has opened a new avenue for creating zeotype materials. This paper presents a comprehensive overview of recent advances in the field of MCM-41. Beginning with the chemistry of surfactant/silicate solutions, progresses made in design and synthesis, characterization, and physicochemical property evaluation of MCM-41 are enumerated. Proposed formation mechanisms are presented, discussed, and identified. Potential applications are reviewed and projected. More than 100 references are cited.

trans-Polyacetylene on sodium and cesium mordenites: a resonance Raman spectroscopic study

Sodium and cesium mordenite (denoted NaM and CsM, respectively) were investigated as potential catalysts for the synthesis of polyacetylene ((CH) x). Both were successful in initiating polymerization of purified gaseous acetylene at room temperature as evidenced by Raman spectroscopic studies. The polyacetylene synthesised in this way exhibited resonance enhancement of the polyene skeletal vibrations. trans-Polyacetylene, but no cis-(CH) x, was detected. As no apparent coloration of the NaM and CsM substrates accompanied the formation of trans-(CH) x it was concluded that only small quantities of the polymer were present. The number of conjugated double bonds was estimated from the frequencies of the Raman active C-C and C=C stretching vibrations, and it was shown that the trans-(CH) x formed on CsM has a distribution of conjugation lengths ranging from less than 6 to at least 30 double bonds. The polyacetylene formed on NaM was significantly shorter and was produced in lower yields than that synthesized on CsM. "Sliced" resonance excitation profiles of polyacetylene formed on CsM were obtained using nearly 40 different excitation wavelengths and these confirmed that the adsorbed trans-(CH) x was composed of segments having a distribution of conjugated lengths. The architecture of the mordenite pore system permitted only a single polymer molecule per channel, thereby preventing cross-linking. Raman spectroscopic studies of the effects of exposure to air revealed that progressive oxidative degradation occurred with a reduction in the number of conjugated double bond

Liquid metal/metal oxide frameworks

A new platform described as the liquid metal/metal oxide (LM/MO) framework is introduced. The constituent spherical structures of these frameworks are made of micro- to nanosized liquid metal spheres and nanosized metal oxides, combining the advantages of both materials. It is shown that the diameters of the spheres and the stoichiometry of the structures can be actively controlled. Additionally, the liquid suspension of these spheres demonstrates tuneable plasmon resonances. These spherical structures are assembled to form LM/MO frameworks which are capable of demonstrating high sensitivity towards low concentrations of heavy metal ions, and enhanced solar light driven photocalalytic activities. These demonstrations imply that the LM/MO frameworks are a suitable candidate for the development of future high performance electronic and optical devices.

Liquid metal/metal oxide frameworks with incorporated Ga2O3 for photocatalysis

Solvothermally synthesized Ga2O3 nanoparticles are incorporated into liquid metal/metal oxide (LM/MO) frameworks in order to form enhanced photocatalytic systems. The LM/MO frameworks, both with and without incorporated Ga2O3 nanoparticles, show photocatalytic activitydue to a plasmonic effect where performance is related to the loading of Ga2O3 nanoparticles. Optimum photocatalytic efficiency is obtained with 1 wt% incorporation of Ga2O3 nanoparticles. This can be attributed to the sub-bandgap states of LM/MO frameworks, contributing to pseudo-ohmic contacts which reduce the free carrier injection barrier to Ga2O3.

The role of organisational culture, trust and mechanisms in inter-project knowledge sharing

Knowledge has been recognised as a powerful yet intangible asset, which is difficult to manage. This is especially true in a project environment where there is the potential to repeat mistakes, rather than learn from previous experiences. The literature in the project management field has recognised the importance of knowledge sharing (KS) within and between projects. However, studies in that field focus primarily on KS mechanisms including lessons learned (LL) and post project reviews as the source of knowledge for future projects, and only some preliminary research has been carried out on the aspects of project management offices (PMOs) and organisational culture (OC) in KS. This study undertook to investigate KS behaviours in an inter-project context, with a particular emphasis on the role of trust, OC and a range of knowledge sharing mechanisms (KSM) in achieving successful inter-project knowledge sharing (I-PKS). An extensive literature search resulted in the development of an I-PKS Framework, which defined the scope of the research and shaped its initial design. The literature review indicated that existing research relating to the three factors of OC, trust and KSM remains inadequate in its ability to fully explain the role of these contextual factors. In particular, the literature review identified these areas of interest: (1) the conflicting answers to some of the major questions related to KSM, (2) the limited empirical research on the role of different trust dimensions, (3) limited empirical evidence of the role of OC in KS, and (4) the insufficient research on KS in an inter-project context. The resulting Framework comprised the three main factors including: OC, trust and KSM, demonstrating a more integrated view of KS in the inter-project context. Accordingly, the aim of this research was to examine the relationships between these three factors and KS by investigating behaviours related to KS from the project managers‘ (PMs‘) perspective. In order to achieve the aim, this research sought to answer the following research questions: 1. How does organisational culture influence inter-project knowledge sharing? 2. How does the existence of three forms of trust — (i) ability, (ii) benevolence and (iii) integrity — influence inter-project knowledge sharing? 3. How can different knowledge sharing mechanisms (relational, project management tools and process, and technology) improve inter-project knowledge sharing behaviours? 4. How do the relationships between these three factors of organisational culture, trust and knowledge sharing mechanisms improve inter-project knowledge sharing? a. What are the relationships between the factors? b. What is the best fit for given cases to ensure more effective inter-project knowledge sharing? Using multiple case studies, this research was designed to build propositions emerging from cross-case data analysis. The four cases were chosen on the basis of theoretical sampling. All cases were large project-based organisations (PBOs), with a strong matrix-type structure, as per the typology proposed by the Project Management Body of Knowledge (PMBoK) (2008). Data were collected from project management departments of the respective organisations. A range of analytical techniques were used to deal with the data including pattern matching logic and explanation building analysis, complemented by the use of NVivo for data coding and management. Propositions generated at the end of the analyses were further compared with the extant literature, and practical implications based on the data and literature were suggested in order to improve I-PKS. Findings from this research conclude that OC, trust, and KSM contribute to inter-project knowledge sharing, and suggest the existence of relationships between these factors. In view of that, this research identified the relationships between different trust dimensions, suggesting that integrity trust reinforces the relationship between ability trust and knowledge sharing. Furthermore, this research demonstrated that characteristics of culture and trust interact to reinforce preferences for mechanisms of knowledge sharing. This means that cultures that facilitate characteristics of Clan type are more likely to result in trusting relationships, hence are more likely to use organic sources of knowledge for both tacit and explicit knowledge exchange. In contrast, cultures that are empirically driven, based on control, efficiency, and measures (characteristics of Hierarchy and Market types) display tendency to develop trust primarily in ability of non-organic sources, and therefore use these sources to share mainly explicit knowledge. This thesis contributes to the project management literature by providing a more integrative view of I-PKS, bringing the factors of OC, trust and KSM into the picture. A further contribution is related to the use of collaborative tools as a substitute for static LL databases and as a facilitator for tacit KS between geographically dispersed projects. This research adds to the literature on OC by providing rich empirical evidence of the relationships between OC and the willingness to share knowledge, and by providing empirical evidence that OC has an effect on trust; in doing so this research extends the theoretical propositions outlined by previous research. This study also extends the research on trust by identifying the relationships between different trust dimensions, suggesting that integrity trust reinforces the relationship between ability trust and KS. Finally, this research provides some directions for future studies.

A comprehensive dual-scale wood torrefaction model : application to the analysis of thermal run-away in industrial heat treatment processes

A dual-scale model of the torrefaction of wood was developed and used to study industrial configurations. At the local scale, the computational code solves the coupled heat and mass transfer and the thermal degradation mechanisms of the wood components. At the global scale, the two-way coupling between the boards and the stack channels is treated as an integral component of the process. This model is used to investigate the effect of the stack configuration on the heat treatment of the boards. The simulations highlight that the exothermic reactions occurring in each single board can be accumulated along the stack. This phenomenon may result in a dramatic eterogeneity of the process and poses a serious risk of thermal runaway, which is often observed in industrial plants. The model is used to explain how thermal runaway can be lowered by increasing the airflow velocity, the sticker thickness or by gas flow reversal.

Integrative genomic profiling reveals conserved genetic mechanisms for tumorigenesis in common entities of non-Hodgkin's lymphoma

Recent developments in genomic technologies have resulted in increased understanding of pathogenic mechanisms and emphasized the importance of central survival pathways. Here, we use a novel bioinformatic based integrative genomic profiling approach to elucidate conserved mechanisms of lymphomagenesis in the three commonest non-Hodgkin's lymphoma (NHL) entities: diffuse large B-cell lymphoma, follicular lymphoma, and B-cell chronic lymphocytic leukemia. By integrating genome-wide DNA copy number analysis and transcriptome profiling of tumor cohorts, we identified genetic lesions present in each entity and highlighted their likely target genes. This revealed a significant enrichment of components of both the apoptosis pathway and the mitogen activated protein kinase pathway, including amplification of the MAP3K12 locus in all three entities, within the set of genes targeted by genetic alterations in these diseases. Furthermore, amplification of 12p13.33 was identified in all three entities and found to target the FOXM1 oncogene. Amplification of FOXM1 was subsequently found to be associated with an increased MYC oncogenic signaling signature, and siRNA-mediated knock-down of FOXM1 resulted in decreased MYC expression and induced G2 arrest. Together, these findings underscore genetic alteration of the MAPK and apoptosis pathways, and genetic amplification of FOXM1 as conserved mechanisms of lymphomagenesis in common NHL entities. Integrative genomic profiling identifies common central survival mechanisms and highlights them as attractive targets for directed therapy.