10 research outputs found
Dynamical torque in CoxFe3–xO4 nanocube thin films characterized by femtosecond magneto-optics : a π-shift control of the magnetization precession
RT and PA would like to thank the Nuffield Foundation (ref. URB40673), the Physics Trust, and the Student Council of the School of Physics and Astronomy at St Andrews to support RT’s research internships. IB and PA acknowledge support from the Engineering and Physical Sciences Research Council (EPSRC, ref. EP/H010033/1).For spintronic devices excited by a sudden magnetic or optical perturbation, the torque acting on the magnetization plays a key role in its precession and damping. However the torque itself can be a dynamical quantity via the time dependent anisotropies of the system. A challenging problem for applications is then to disentangle the relative importance of various sources of anisotropies in the dynamical torque, such as the dipolar field, the crystal structure or the shape of the particular interacting magnetic nanostructures. Here, we take advantage of a range of colloidal cobalt ferrite nano-cubes assembled in 2D thin films under controlled magnetic fields to demonstrate that the phase φprec of the precession carries a strong signature of the dynamical anisotropies. Performing femtosecond magneto-optics, we show that φprec displays a π-shift for a particular angle θH of an external static magnetic field H. θH is controlled with the cobalt concentration, the laser intensity as well as the inter-particles interactions. Importantly it is shown that the shape anisotropy, which strongly departs from the one of equivalent bulk thin films or individual non-interacting nanoparticles, reveals the essential role played by the interparticles collective effects. This work shows the reliability of a non-invasive optical approach to characterize the dynamical torque in high density magnetic recording media made of organized and interacting nanoparticles.Publisher PDFPeer reviewe
Structure-guided design and optimization of small molecules targeting the protein-protein interaction between the von hippel-lindau (VHL) E3 ubiquitin ligase and the hypoxia inducible factor (HIF) alpha subunit with in vitro nanomolar affinities
E3 ubiquitin ligases are attractive targets in the ubiquitin-proteasome system, however, the development of small-molecule ligands has been rewarded with limited success. The von Hippel-Lindau protein (pVHL) is the substrate recognition subunit of the VHL E3 ligase that targets HIF-1α for degradation. We recently reported inhibitors of the pVHL:HIF-1α interaction, however they exhibited moderate potency. Herein, we report the design and optimization, guided by X-ray crystal structures, of a ligand series with nanomolar binding affinities
A hybrid architecture (CO-CONNECT) to facilitate rapid discovery and access to data across the United Kingdom in response to the COVID-19 pandemic: development study
Dynamical Torque in CoxFe3xO4 Nanocube Thin Films Characterized by Femtosecond Magneto-Optics: A Shift Control of the Magnetization Precession
Dynamical Torque in Co<sub><i>x</i></sub>Fe<sub>3–<i>x</i></sub>O<sub>4</sub> Nanocube Thin Films Characterized by Femtosecond Magneto-Optics: A π‑Shift Control of the Magnetization Precession
For spintronic
devices excited by a sudden magnetic or optical perturbation, the
torque acting on the magnetization plays a key role in its precession
and damping. However, the torque itself can be a dynamical quantity
via the time-dependent anisotropies of the system. A challenging problem
for applications is then to disentangle the relative importance of
various sources of anisotropies in the dynamical torque, such as the
dipolar field, the crystal structure or the shape of the particular
interacting magnetic nanostructures. Here, we take advantage of a
range of colloidal cobalt ferrite nanocubes assembled in 2D thin films
under controlled magnetic fields to demonstrate that the phase, ϕ<sub>Prec</sub>, of the precession carries a strong signature of the dynamical
anisotropies. Performing femtosecond magneto-optics, we show that
ϕ<sub>Prec</sub> displays a π-shift for a particular angle
θ<sub>H</sub> of an external static magnetic field, <b>H</b>. θ<sub>H</sub> is controlled with the cobalt concentration,
the laser intensity, as well as the interparticle interactions. Importantly,
it is shown that the shape anisotropy, which strongly departs from
those of equivalent bulk thin films or individual noninteracting nanoparticles,
reveals the essential role played by the interparticle collective
effects. This work shows the reliability of a noninvasive optical
approach to characterize the dynamical torque in high density magnetic
recording media made of organized and interacting nanoparticles
Data underpinning: Dynamical torque in CoxFe3–xO4 nanocube thin films characterized by femtosecond magneto-optics
Data used in the publication Dynamical torque in CoxFe3–xO4 nanocube thin films characterized by femtosecond magneto-optic
A Hybrid Architecture (CO-CONNECT) to Facilitate Rapid Discovery and Access to Data Across the United Kingdom in Response to the COVID-19 Pandemic: Development Study.
BACKGROUND: COVID-19 data have been generated across the United Kingdom as a by-product of clinical care and public health provision, as well as numerous bespoke and repurposed research endeavors. Analysis of these data has underpinned the United Kingdom's response to the pandemic, and informed public health policies and clinical guidelines. However, these data are held by different organizations, and this fragmented landscape has presented challenges for public health agencies and researchers as they struggle to find relevant data to access and interrogate the data they need to inform the pandemic response at pace. OBJECTIVE: We aimed to transform UK COVID-19 diagnostic data sets to be findable, accessible, interoperable, and reusable (FAIR). METHODS: A federated infrastructure model (COVID - Curated and Open Analysis and Research Platform [CO-CONNECT]) was rapidly built to enable the automated and reproducible mapping of health data partners' pseudonymized data to the Observational Medical Outcomes Partnership Common Data Model without the need for any data to leave the data controllers' secure environments, and to support federated cohort discovery queries and meta-analysis. RESULTS: A total of 56 data sets from 19 organizations are being connected to the federated network. The data include research cohorts and COVID-19 data collected through routine health care provision linked to longitudinal health care records and demographics. The infrastructure is live, supporting aggregate-level querying of data across the United Kingdom. CONCLUSIONS: CO-CONNECT was developed by a multidisciplinary team. It enables rapid COVID-19 data discovery and instantaneous meta-analysis across data sources, and it is researching streamlined data extraction for use in a Trusted Research Environment for research and public health analysis. CO-CONNECT has the potential to make UK health data more interconnected and better able to answer national-level research questions while maintaining patient confidentiality and local governance procedures
CO-CONNECT: A hybrid architecture to facilitate rapid discovery and access to UK wide data in the response to the COVID-19 pandemic
BACKGROUND: COVID-19 data have been generated across the United Kingdom as a by-product of clinical care and public health provision, as well as numerous bespoke and repurposed research endeavors. Analysis of these data has underpinned the United Kingdom's response to the pandemic, and informed public health policies and clinical guidelines. However, these data are held by different organizations, and this fragmented landscape has presented challenges for public health agencies and researchers as they struggle to find relevant data to access and interrogate the data they need to inform the pandemic response at pace. OBJECTIVE: We aimed to transform UK COVID-19 diagnostic data sets to be findable, accessible, interoperable, and reusable (FAIR). METHODS: A federated infrastructure model (COVID - Curated and Open Analysis and Research Platform [CO-CONNECT]) was rapidly built to enable the automated and reproducible mapping of health data partners' pseudonymized data to the Observational Medical Outcomes Partnership Common Data Model without the need for any data to leave the data controllers' secure environments, and to support federated cohort discovery queries and meta-analysis. RESULTS: A total of 56 data sets from 19 organizations are being connected to the federated network. The data include research cohorts and COVID-19 data collected through routine health care provision linked to longitudinal health care records and demographics. The infrastructure is live, supporting aggregate-level querying of data across the United Kingdom. CONCLUSIONS: CO-CONNECT was developed by a multidisciplinary team. It enables rapid COVID-19 data discovery and instantaneous meta-analysis across data sources, and it is researching streamlined data extraction for use in a Trusted Research Environment for research and public health analysis. CO-CONNECT has the potential to make UK health data more interconnected and better able to answer national-level research questions while maintaining patient confidentiality and local governance procedures.</p