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Synthesis of 3-stannyl and 3-silyl propargyl phosphanes and the formation of a phosphinoallene
The group 14 chloropropargyls R3ECCCH2Cl (R3E = Bu3Sn, Ph3Sn, Me2PhSi, iPr3Si, nPr3Si, nBu3Si), obtained by a modified literature procedure, react with LiPPh2 to afford the novel propargyl phosphanes Ph2PCH2CCER3 in high yield, as viscous oils; (Me3Si)2PCH2CCSiPhMe2 is similarly obtained from LiP(SiMe3)2. In contrast, the reaction of PhCCCH2MgCl with ClP(NEt2)2 fails to produce a comparable propargyl phosphane, but generates preferentially (>70%) the novel phosphinoallene (Et2N)2PC(Ph)=C=CH2, which is characterised spectroscopically, and through its reaction with HCl. The coordination chemistry of representative phosphanes is explored with respect to platinum and palladium for the first time
Room temperature self-assembly of mixed nanoparticles into complex material systems and devices
The ability to manufacture nanomaterials with complex and structured
composition using otherwise incompatible materials increasingly underpins the
next generation of technologies. This is translating into growing efforts
integrating a wider range of materials onto key technology platforms1 - in
photonics, one such platform is silica, a passive, low loss and robust medium
crucial for efficient optical transport2. Active functionalisation, either
through added gain or nonlinearity, is mostly possible through the integration
of active materials3, 4. The high temperatures used in manufacturing of silica
waveguides, unfortunately, make it impossible to presently integrate many
organic and inorganic species critical to achieving this extended
functionality. Here, we demonstrate the fabrication of novel waveguides and
devices made up of complex silica based materials using the self-assembly of
nanoparticles. In particular, the room temperature fabrication of silica
microwires integrated with organic dyes (Rhodamine B) and single photon
emitting nanodiamonds is presented.Comment: Key words: nanotechnology, nanoparticles, self-assembly, quantum
science, singel photon emitters, telecommunications, sensing, new materials,
integration of incompatible materials, silica, glass, breakthrough scienc
Lentiviral manipulation of gene expression in human adult and embryonic stem cells
Human stem cells could revolutionize the field of medicine by providing a diverse range of cell types for tissue replacement therapies and drug discovery. To achieve this goal, genetic tools need to be optimized and developed for controlling and manipulating stem cells ex vivo. Here we describe a lentiviral delivery system capable of high infection rates in human mesenchymal and embryonic stem cells. The lentiviral backbone was modified to express mono- and bi-cistronic transgenes and was also used to deliver short hairpin ribonucleic acid for specific silencing of gene expression in human stem cells. We show that lentiviral transduction can be used to alter gene expression without altering the genes' ability to differentiate in vitro. These vectors will enable rapid analysis of gene function in stem cells and permit the generation of knock-in / knock-out models of human disease in the rapidly developing field of gene therapy
Wind turbine blade design
A detailed review of the current state-of-art for wind turbine blade design is presented, including theoretical maximum efficiency, propulsion, practical efficiency, HAWT blade design, and blade loads. The review provides a complete picture of wind turbine blade design and shows the dominance of modern turbines almost exclusive use of horizontal axis rotors. The aerodynamic design principles for a modern wind turbine blade are detailed, including blade plan shape/quantity, aerofoil selection and optimal attack angles. A detailed review of design loads on wind turbine blades is offered, describing aerodynamic, gravitational, centrifugal, gyroscopic and operational conditions
Improving the quality of written feedback using written feedback
Background: Educational feedback is amongst the most powerful of all learning interventions. Research questions: (1) Can we measure the quality of written educational feedback with acceptable metrics? (2) Based on such a measure, does a quality improvement (QI) intervention improve the quality of feedback? Study design: We developed a QI instrument to measure the quality of written feedback and applied it to written feedback provided to medical students following workplace assessments. We evaluated the measurement characteristics of the QI score using generalisability theory. In an uncontrolled intervention, QI profiles were fed back to GP tutors and pre and post intervention scores compared. Study results: A single assessor scoring 6 feedback summaries can discriminate between practices with a reliability of 0.82.The quality of feedback rose for two years after the introduction of the QI instrument and stabilised in the third year. The estimated annual cost to provide this feedback is £12 per practice. Interpretation and recommendations: It is relatively straightforward and inexpensive to measure the quality of written feedback with good reliability. The QI process appears to improve the quality of written feedback. We recommend routine use of a QI process to improve the quality of educational feedback
Who the hell was that? Stories, bodies and actions in the world
This article explores a two-way relationship between stories and the experiential actions of bodies in the world. Through an autoethnographic approach, the article presents a series of interlinked story fragments in an effort to show and evoke a feel for the ways in which stories, bodies, and actions influence and shape each other over time. It offers some reflections on the experiences the stories portray from the perspective of a social constructionist conception of narrative theory and suggest that while stories exert a powerful influence on the actions of our bodies, our bodies intrude on or ‘talk back’ to this process because bodies have an existence beyond stories
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