Methods of high current magnetic field generator for transcranial magnetic stimulation application

This paper describes the design procedures and underlying concepts of a novel High Current Magnetic Field Generator (HCMFG) with adjustable pulse width for transcranial magnetic stimulation applications. This is achieved by utilizing two different switching devices, the MOSFET and insulated gate bipolar transistor (IGBT). Results indicate that currents as high as ± 1200 A can be generated with inputs of +/-20 V. Special attention to tradeoffs between field generators utilizing IGBT circuits (HCMFG1) and MOSFET circuits (HCMFG2) was considered. The theory of operation, design, experimental results, and electronic setup are presented and analyzed

Low velocity quantum reflection of Bose-Einstein condensates

We studied quantum reflection of Bose-Einstein condensates at normal incidence on a square array of silicon pillars. For incident velocities of 2.5-26 mm/s observations agreed with theoretical predictions that the Casimir-Polder potential of a reduced density surface would reflect slow atoms with much higher probability. At low velocities (0.5-2.5 mm/s), we observed that the reflection probability saturated around 60% rather than increasing towards unity. We present a simple model which explains this reduced reflectivity as resulting from the combined effects of the Casimir-Polder plus mean field potential and predicts the observed saturation. Furthermore, at low incident velocities, the reflected condensates show collective excitations.Comment: 4 figure

Setting international standards for patient and parent involvement and engagement in childhood, adolescent and young adult cancer research: A report from a European Collaborative Workshop

BACKGROUND: Patient and Public Involvement and Engagement (PPIE) in research, advocates for research conducted ‘with’ not ‘for’ the affected population. In paediatric oncology research, the parents of children, adolescents and young adults affected by cancer are represented by the term ‘public’ in the acronym PPIE. Patients (those with cancer and cancer survivors) are also passionate advocates who drive forward the research priorities of children, adolescents and young adults throughout the entire research process. AIMS: A workshop was held at an international professional meeting in 2019 with the aim to define Patient and Parent Involvement and Engagement (PPIE); capture PPIE activities on a European level; and to explore the role of PPIE in non-interventional research. A proposed framework for a European PPIE strategy for childhood, adolescent and young adult cancers was also discussed. METHODS: The 60-minute workshop was attended by health care professionals, researchers, scientists, parents, survivors and charity/support organisations. A presentation to define PPIE, including the difference in terminology for PPIE in the context of childhood, adolescent, and young adult cancers was discussed. Best practice examples from the United Kingdom (UK) helped to demonstrate the positive impact of PPIE in paediatric oncology research. Three breakout groups then explored themes relating to PPIE, namely PPIE priorities, PPIE mapping for Europe, and PPIE in non-interventional research and data-linkage. RESULTS: Disparity in PPIE activities across Europe was evident, with ambiguity surrounding terminology and expected roles for PPIE representatives in paediatric oncology research. A lack of PPIE activity in Eastern Europe correlated with a lack of availability for clinical trials and poorer survival rates for paediatric oncology patients. There was unanimous support for PPIE embedded research in all areas, including in non-interventional studies. CONCLUSION: A European-level definition of PPIE for paediatric oncology research is needed. Further exploration into the role and responsibilities of patients, parents, and professionals when undertaking PPIE related activities is also recommended. Best practice examples from the UK, France, Germany, The Netherlands and Belgium demonstrated a preliminary evidence base from which a European PPIE strategy framework can be designed, inclusive of the patient and parent voice

Infrared activity of hydrogen molecules trapped in Si

The rovibrational-translational states of a hydrogen molecule moving in a cage site in Si, when subjected to an electrical field arising from its surroundings, are investigated. The wave functions are expressed in terms of basis functions consisting of the eigenfunctions of the molecule confined to move in the cavity and rovibrational states of the free molecule. The energy levels, intensities of infrared and Raman transitions, effects of uniaxial stress, and a neighboring oxygen defect are found and compared with existing experimental data

Long Phase Coherence Time and Number Squeezing of two Bose-Einstein Condensates on an Atom Chip

We measured the relative phase of two Bose-Einstein condensates confined in an radio frequency induced double well potential on an atom chip. We observed phase coherence between the separated condensates for times up to 200 ms after splitting, a factor of 10 beyond the phase diffusion limit expected for a coherent state in our experimental conditions (20 ms). The enhanced coherence time is attributed to number squeezing of the initial state by a factor of 10. In addition, we demonstrated a rotationally sensitive (Sagnac) geometry for a guided atom interferometer by propagating the split condensates.Comment: 5 pages, 5 figure

Randomized Benchmarking using Non-Destructive Readout in a 2D Atom Array

Neutral atoms are a promising platform for scalable quantum computing, however prior demonstration of high fidelity gates or low-loss readout methods have employed restricted numbers of qubits. Using randomized benchmarking of microwave-driven single-qubit gates, we demonstrate single qubit gate errors of $8(2)\times10^{-5}$ on 225 atoms using conventional, destructive readout. This exceeds the threshold for fault-tolerance. We further demonstrate suppression of measurement errors via low-loss, non-destructive and state-selective readout on 49 atoms. This enables post-selection for atom loss, which is a primary source of errors in present setups.Comment: 6 pages, 4 figures plus Supplementary Materia

Background and design of a qualitative study on globally responsible decision-making in civil engineering

Organizations that regulate civil engineering have been pressing for integration of 'global responsibility' into higher education curricula since around 2006, with a goal of achieving environmental sustainability and social justice. In an effort led by the American Society of Civil Engineers (ASCE, 2007, 2009), a global vision for civil engineering was identified. Within the UK, the Institution of Civil Engineers (ICE) has been leading the way alongside non-governmental organizations (Bourn & Neal, 2008). Via the in-progress study reported here, a UK-based research team is now studying the effects of ACSE and ICE initiatives. The team seeks to benchmark how global responsibility is perceived and enacted in civil engineering in the UK today and how engineering graduates have learned about and experienced globally responsible decision-making. Findings will hold value for the global community, as achieving sustainability is crucial to humanity, and indeed all life on Earth

Prognostic significance of histopathological response to preoperative chemotherapy in unilateral Wilms' tumor: An analysis of 899 patients treated on the SIOP WT 2001 protocol in the UK-CCLG and GPOH studies

In the SIOP Wilms' tumor (WT) studies, preoperative chemotherapy is used as primary treatment, and tumors are classified thereafter by pathologists. Completely necrotic WTs (CN-WTs) are classified as low-risk tumors. The aim of the study was to evaluate whether a subset of regressive type WTs (RT-WTs) (67%-99% chemotherapy-induced changes [CIC]) showing an exceptionally good response to preoperative chemotherapy had comparably excellent survivals as CN-WTs, and to establish a cut-off point of CIC that could define this subset. The study included 2117 patients with unilateral, nonanaplastic WTs from the UK-CCLG and GPOH-WT studies (2001-2020) treated according to the SIOP-WT-2001 protocol. There were 126 patients with CN-WTs and 773 with RT-WTs, stages I-IV. RT-WTs were subdivided into subtotally necrotic WTs (>95% CIC) (STN-WT96-99) (124 patients) and the remaining of RT-WT (RR-WT67-95) (649 patients). The 5-year event-free survival (EFS) and overall survival (OS) for CN-WTs were 95.3% (±2.1% SE) and 97.3% (±1.5% SE), and for RT-WTs 85.7% (±1.14% SE, P < .01) and 95.2% (±0.01% SE, P = .59), respectively. CN-WT and STN-WT96-99 groups showed significantly better EFS than RR-WT67-95 (P = .003 and P = .02, respectively), which remained significantly superior when adjusted for age, local stage and metastasis at diagnosis, in multivariate analysis, whereas OS were superimposable (97.3 ± 1.5% SE for CN-WT; 97.8 ± 1.5% SE for STN-WT96-99; 94.7 ± 1.0% SE for RR-WT67-95). Patients with STN-WT96-99 share the same excellent EFS and OS as patients with CN-WTs, and although this was achieved by more treatment for patients with STN-WT96-99 than for patients with CN-WT, reduction in postoperative treatment of these patients may be justified