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Viewing upcoming talks containing the keyword: 3
Chemical Probes of Natural Product Assemblies: Novel Biosynthetic Insights and Opportunities (EaStCHEM/BSRC Joint Colloquium)
Speaker: Manuela Tosin (Warwick)
Chemical Probes of N atural Product Assemblies : Novel Biosynthetic Insights and O pportunities Manuela Tosin Department of Chemistry, University of Warwick, Coventry, UK E-mail: email@example.com Natural products and their derivatives constitute a ma jor source of treatments for h uman, animal and plant diseases. A comprehensive mechanistic and temporal elucidation of natural product biosynthetic pathways is of the highest priority, as it paves the way to the generation of novel high -value molecules via enzyme and metabolic engineering . In our group we have devised a chem ical approach for the detailed investigation of polyketide and nonribosomal peptide product assembly : this consists in the use of chemical probes capable of ‘capturing ’ transient biosyn thetic intermediates in a readily analysable form .1 The knowledge of biosynthetic processing has allowed us to envisage new chemoenzymatic routes to natural product derivatives, such as to unnatural polyethers (Fig. 1). 2 Herein I will present our latest chemical tool development for the study of natural product enzymatic assemblies 3-6 and discuss key findings in view of their exploitation .
Figure 1 : Fuctionalised chemical probes ( 1) capable of reacting with polyketide synthase -bound intermediates 4 can be utilised for in vivo polyketide diversification. 2 Representative publications :
1. M. Tosin, * L. Smith, P. F. Leadlay, Angew. Chem. Int. Ed. 2011 , 50 , 11930 -11933. 2. E. Riva, I. Wilkening, S. Gazzola, W. M. A. Li, L. Smith, P. F. Leadlay, M. Tosin ,* Angew. Chem. Int. Ed. 2014 , 53 , 11944 -11949 . 3. J. S. Parascan dolo, J. Havemann, H. K. Potter, F. Huang, E. Riva, J. Connolly, I. Wilkening, L. Song, P. F. Leadlay, M. Tosin ,* Angew. Chem. Int. Ed . 2016 , 55, 3463 -7. 4. I. Wilkening, S. Gazzola, J. S. P arascandolo, E. Riva, L. Song, M. Tosin ,* Chem. Commun . 2016 , 52, 10392 -10395. 5. J. Havemann, M. E. Yurkovich, R. Jenkins, S. Harringer, W. Tao, S. Wen, Y. Sun, P. F. Leadlay, M. Tosin,* Chem. Commun . 2017 , 53 , 1912 -1915. 6. Y. T. C. Ho, D. J. Leng, F. Ghiringhelli, I. Wilkening, D. P. Bushell, O. Kostner, E. Riva, J. Havemann, D. Passarella, M. Tosin ,* Chem. Commun . 2017 , 53 , 7088 -7091 . Fermentation and Staudinger Fermentation and ‘Click’ Download PDF
On: November 22, 2017 From: 15h30 To: 16h30View talk
Cond Mat Seminars
Speaker: Marina Filip (University of Oxford)
Perovskite solar cells are emerging as one of the most promising photovoltaic technologies, havingexceeded the performance of thin-film silicon devices (beyond 21%) in only 5 years of development.This performance is exclusively due to the optimum optoelectronic properties of the prototypical organic-inorganic lead-halide perovskite, methylammonium lead-iodide (CH 3 NH 3 PbI 3 ), and related lead halides.The fast-paced development of the perovskite solar cells has not only fueled a growing interest into thefundamental physical properties of lead-halide perovskites, but has also been stimulating the design ofnew functional perovskites with tailor-made properties.
In the first part of my talk I will focus on the computational modelling of the optoelectronic propertiesof CH 3 NH 3 PbI 3 . I will give a brief introduction into the state-of-the-art first principles methods usedin our work, such as the density functional theory (DFT) and the GW approximation. I will presentour calculations of the quasiparticle band structure, band gap and charge carrier effective masses ofCH 3 NH 3 PbI 3 [1,2], and show that the GW approach is essential in the accurate description of theoptoelectronic properties of CH 3 NH 3 PbI 3 . Furthermore, I will show that by substituting the CH 3 NH 3cation with CH(NH 2 ) 2 , Cs, or Rb, the band gap of the lead-halide perovskites can be fine-tuned in thevisible range by engineering the steric interactions between the central cation and the inorganic PbI 6network .
In the second part of my talk I will present some of our most recent efforts into the computationaldesign of lead-free metal-halide perovskites for optoelectronics. In this part I will briefly outline thehigh-throughput computational strategy we have used in our search , and discuss the main outcomeof this screening, the computational discovery of two new lead-free semiconducting metal-halide doubleperovskites, Cs 2 BiAgCl 6 and Cs 2 BiAgBr 6 [6,7]. Filip, M.R., Verdi, C. and Giustino, F. J. Phys. Chem. C, 119 (45), 25209 (2015) Filip, M.R. and Giustino, F. J. Phys. Rev. B, 90 (24), 245145 (2014) Davies, C. L., Filip, M.R., Patel, J. B., Verdi, C., Milot, R. L., Giustino, F., Johnston, M. B. andHerz, L. M., Under Review (2017) Filip, M.R., Eperon, G. E., Snaith, H. J. and Giustino, F. J. Nat. Commun. 5, 5757 (2014) Filip, M.R. and Giustino, F. J. Phys. Chem. C, 120 (1), 166 (2016) Volonakis, G., Filip, M. R., Haghighirad, A. A., Sakai, N., Wenger, B., Snaith, H.J. and Giustino, F.,J Phys Chem Lett 7 (7) 1254-1259 (2016) Filip, M.R., Hillman, S., Haghighirad, A. A., Snaith, H. J. and Giustino, F., J. Phys. Chem. Lett. 7(13), 4554-4562 (2016)
On: November 22, 2017 From: 12h00 To: 13h00View talk
History of Mathematics
Speaker: Tony Royle (Open University)
Early aeronautical research in Britain was advanced by a decision to allow a number of the nation’s finest mathematicians to train as pilots and conduct airborne experiments using full-scale aircraft. Given that many would subsequently perish in flying accidents, what justified the risk?
On: November 22, 2017 From: 16h00 To: 17h00View talk
Physics and Astronomy Colloquia
Speaker: Kirsten von Bergmann (University of Hamburg)
Magnetic skyrmions are particle-like knots in the magnetization. They are envisioned asthe basis for future spintronic devices and can be stabilized by a favorable interplay ofmagnetic exchange, Dzyaloshinskii-Moriya interaction (DMI), anisotropy and Zeemanenergy. The Fe/Ir(111) interface is known to exhibit strong DMI  and serves as anideal basis to build up materials that host single skyrmions on the nanometer lengthscale. Such small magnetic objects can be imaged, characterized and manipulated using(spin-resolved) scanning tunneling microscopy (STM) .Building upon the Fe/Ir(111)-interface a fine-tuning of the relevant magnetic energies isperformed by adding metallic overlayers, by adorption of hydrogen, or by a variation ofthe strain within the magnetic film. Magnetic field dependent STM measurements canbe used to obtain the specific material parameters . In addition, spectroscopy using anon-magnetic tip electrode reveales the correlation between the local magnetoresistanceand the non-collinearity of the spin texture . Such a read-out of the local magneticstate could be combined with the demonstated reversible switching between skyrmionand ferromagnet by local electric fields . S. Heinze et al., Nature Phys. 7, 718 (2011). K. von Bergmann et al., J. Phys.: Condens. Matter 26, 394002 (2014). N. Romming et al., Phys. Rev. Lett. 114, 177203 (2015). C. Hanneken et al., Nature Nanotech. 10, 1039 (2015). P.-J. Hsu et al., Nature Nanotech. 12, 123 (2017).
On: November 24, 2017 From: 10h00 To: 11h00View talk
Physics and Astronomy Colloquia
Speaker: Elizabeth Blackburn (University of Birmingham)
The high-temperature superconductors were discovered just over 30 years ago. The initial observation was accompanied by an explosion of results probing and examining how they behaved, establishing some ground rules for the type of superconductivity observed – similar but different to the well-known BCS model for superconductivity. Over the last 5 years, there have been a number of breakthroughs in understanding the background from which the superconducting state develops. In this colloquium, I will pull together structural information, quantum oscillation, transport data and dynamical studies to describe the new observations, and look at how that helps with understanding high-temperature superconductivity, closing with the (many) open questions remaining.
On: December 1, 2017 From: 10h00 To: 11h00View talk
Physics and Astronomy Colloquia
Speaker: Ryan Hickox (University of Dartmouth)
At the heart of essentially every large galaxy in the Universe lies a supermassive black hole. In the past decade, surveys of the extragalactic sky have made great progress in understanding the cosmic growth of these black holes, as they "eat" surrounding material and radiate as active galactic nuclei (AGN). However, our picture of black hole evolution has remained incomplete, due to the challenges of detecting black holes that are highly obscured by gas and dust or hidden beneath thelight of their host galaxies. With the advent of new resources including hard X-ray observations from NuSTAR, mid-infrared data from WISE, and new insights from theoretical models, we can now identify millions of these “hidden” growing black holes across much the sky, and characterize the nature of their obscuration and their role in the formation of galaxies. I will describe recent efforts to characterize these "hidden” black holes, particularly highlighting work by our group at Dartmouth, and will present evidence that (at least some) powerful obscured AGN represent an evolutionary phase in the evolution of their host galaxies. Finally, I will point to the exciting potential for future of AGN population studies with the next generation of extragalactic surveys, including with NASA's Lynx concept X-ray mission.
On: December 8, 2017 From: 10h00 To: 11h00View talk