08:15 am (Brazilian time) / 11:15 am (UK time) :

Unveiling Drug Delivery Systems using Small Angle Scattering Techniques 

Speaker: ​Fabiano Yokaichiya (University of Parana, PR, Brazil), 

Abstract: The study of drug delivery systems involves the use of techniques such as small-angle neutron scattering (SANS, VSANS, and USANS) and small-angle X-ray scattering (SAXS, USAXS), which can provide information about complex systems such as poloxamers, lipids, cyclodextrins, alginates, and their combinations (poloxamers + poloxamers, poloxamers + cyclodextrins, and poloxamers + lipids, lipids + cyclodextrins). These techniques reveal the changes these systems undergo with the addition of drugs, as well as their behavior in response to temperature. Studies have been conducted on drug delivery systems for pain treatment (such as tramadol, lidocaine, tetracaine, bupivacaine, and ropivacaine), for migraine treatment (such as sumatriptan), for cancer and autoimmune disease treatment (doxorubicin, sulforaphane, docetaxel, paclitaxel, cyclosporine), and for oral use (ibuprofen, ketoprofen, diclofenac, prednisone, paracetamol), using SAXS through laboratory instruments (LORXI) and large facilities like synchrotrons, as well as SANS/USANS through large facilities such as research reactors and scattering sources. The use of inelastic neutron scattering is particularly interesting as it enables the acuisition of information about the dynamics of components in these systems, such as water movement (structural or confined) and drug-carrier interactions.​.​

11:00 (Brazilian time) / 14:00 (UK time) :

How to write successful ISIS proposals 

Speaker: ​Helen Walker (ISIS)

Abstract: The current ISIS proposal round has just opened, and so now i​s the ideal time to discuss how to write successful proposals before the next deadline of 16 April. I will cover how the proposal system works and provide an opportunity to ask for advice about how to optimise the success of your beamtime application.​ 

13:00 (Brazilian time) / 16:00 (UK time) :

CuSb2O6: a quasi-1D antiferromagnet with orbital degeneracy

Speaker: ​Eduardo Granado (University of Campinas, SP, Brazil)

Abstract: Quasi-1D magnetism with enhanced quantum fluctuation effects can be found in 3D materials showing dominant exchange interactions along one direction. The CuSb2O6 cuprate with trirutile structure is an example, where the magnetic susceptibility curve with a broad maximum at ~60 K is well modeled by a 1D Bonner and Fisher model [1] with J ~ -100 K, associated with antiferromagnetic Cu-O-O-Cu superexchange interaction along a specific direction. Previous DFT calculations suggested that this behavior is driven by an unusual ordering of half-filled 3d 3z2-r2 orbitals [2]. Here, the magnetism and orbital configuration of CuSb2O6 is investigated by Resonant Inelastic X-Ray Scattering (RIXS) experiments in the magnetically correlated state at T~20 K, complementing previous neutron diffraction investigations [3]. The investigated d-d excitations comprise a broad peak at E=0.45 eV due to eg-eg excitations and three sharper excitations in the range E ~1.1-1.5 eV due to t2g-eg excitations. We demonstrate that a simple orbital ordering scenario considering either 3z2-r2 or x2-y2 orbitals oriented with respect to the chain direction cannot explain the observed RIXS spectra. Substantial improvement in the comparison with experimental data is obtained if a combination of these orthogonal orbital configurations is assumed, indicating an unexpected orbital mixing for this system. Remarkably, our results indicate that the spin quantization axis is along the 1D chain direction. Implications of these results to the 1D magnetism of CuSb2O6 will be discussed.
References
[1] J. C. Bonner and M. E. Fisher, Phys. Rev. 135, A640 (1964).
[2] D. Kasinathan, K. Koepernik and H. Rosner, Phys. Rev. Lett. 100, 237202 (2008).
[3] A.M. Nakua and J.E. Greedan, J. Sol. State Chem.118, 199 (1995)..​