42 research outputs found

    Sentinel lymph node biopsies in early stage oral and oropharyngeal carcinoma : a retrospective single-centre experience

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    The aim of this retrospective study was to analyse a consecutive series of patients with oral and oropharyngeal carcinoma who had had sentinel lymph node biopsy (SLNB) at our hospital during 2008-2017. A total of 70 patients with clinically and radiologically confirmed primary oral (n = 67) or oropharyngeal (n = 3) carcinoma, with no signs of metastatic lymph nodes preoperatively (clinically N0) were included. Patients' clinical and personal data, characteristics of the tumours, sentinel lymph node (SLN) status and outcomes were recorded. Eight patients had invaded SLN. Two patients with clear sentinel lymph node biopsies had recurrences in the cervical lymph nodes with no new primary tumour as origin. The negative predictive value (NPV) and sensitivity for SLNB were 97% and 80%, respectively. The depth of invasion was an individual predictor for cervical lymph node metastasis (p = 0.043). Single photo emission computed tomography (SPECT) detected fewer SLN in patients with invaded lymph nodes than in patients with clear lymph nodes (p = 0.018). Our data support the use of SLNB as a minimally invasive method for staging the cervical lymph nodes among patients with cN0 oral and oropharyngeal carcinoma. Our results further confirm that greater depth of invasion is associated with cervical lymph node metastases. (c) 2020 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.Peer reviewe

    SUNSTORM 1/X-ray Flux Monitor for CubeSats (XFM-CS) : Instrument characterization and first results

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    SUNSTORM 1 CubeSat was launched to Sun-synchronous low Earth orbit on August 17 2021. The primary purpose of the mission is an in-orbit demonstration of X-ray Flux Monitor (XFM) instrument. XFM is an innovative solar X-ray spectrometer for measuring and characterizing solar flares, which are known to be linked to a variety of space weather phenomena. XFM represents a next generation of solar X-ray flux monitors. It is based on silicon drift detector technology, which provides several notable performance improvements over its predecessors, which are based on Si PIN detectors. Transversal electric field and lower output capacitance allow operation at much faster pulse processing shaping times, allowing the system to achieve about 10 times higher throughput without saturation while also making it less sensitive to the increase of leakage current due to high temperature and/or radiation damage. Thus, XFM instruments can cover a very wide dynamic range of solar X-ray emission from the most quiescent conditions to the strongest X-class solar flares, while maintaining good spectral resolution (Peer reviewe

    Calibration of RADMON radiation monitor onboard Aalto-1 CubeSat

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    RADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the ΔE-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed

    The Finnish psychiatric birth cohort consortium (PSYCOHORTS) - content, plans and perspectives

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    Background: Psychiatric disorders tend to be developmental, and longitudinal settings are required to examine predictors of psychiatric phenomena. Replicating and combining data and results from different birth cohorts, which are a source of reliable data, can make research even more valuable. The Finnish Psychiatric Birth Cohort Consortium (PSYCOHORTS) project combines birth cohorts in Finland. Aim: The aim of this paper is to introduce content, plans and perspectives of the PSYCOHORTS project that brings together researchers from Finland. In addition, we illustrate an example of data harmonization using available data on causes of death. Content: PSYCOHORTS includes eight Finnish birth cohorts. The project has several plans: to harmonize different data from birth cohorts, to incorporate biobanks into psychiatric birth cohort research, to apply multigenerational perspectives, to integrate longitudinal patterns of marginalization and inequality in mental health, and to utilize data in health economics research. Data on causes of death, originally obtained from Finnish Cause of Death register, were harmonized across the six birth cohorts using SAS macro facility. Results: Harmonization of the cause of death data resulted in a total of 21,993 observations from 1965 to 2015. For example, the percentage of deaths due to suicide and the sequelae of intentional self-harm was 14% and alcohol-related diseases, including accidental poisoning by alcohol, was 13%. Conclusions: PSYCOHORTS lays the foundation for complex examinations of psychiatric disorders that is based on compatible datasets, use of biobanks and multigenerational approach to risk factors, and extensive data on marginalization and inequality

    Theory and practice in Finnish teacher education : a rhetorical analysis of changing values from the 1960s to the present day

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    Our aim in this article is to examine the relationship between theory and practice in Finnish teacher education from the 1960s to the present. We identify four different periods to represent this relationship based on our analysis of national committee and evaluation reports. Theory and practice gradually converged, culminating in a research-based agenda that reflects the current situation. This relationship between theory and practice also reflects the ideal teacher of different times and what a teacher's working orientation should be. We use rhetorical analysis and the concept of a 'philosophical pair' introduced by Perelman and Olbrechts-Tyteca to interpret this development.Peer reviewe

    Aalto-1, multi-payload CubeSat: design, integration and launch

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    The design, integration, testing, and launch of the first Finnish satellite Aalto-1 is briefly presented in this paper. Aalto-1, a three-unit CubeSat, launched into Sun-synchronous polar orbit at an altitude of approximately 500 km, is operational since June 2017. It carries three experimental payloads: Aalto Spectral Imager (AaSI), Radiation Monitor (RADMON), and Electrostatic Plasma Brake (EPB). AaSI is a hyperspectral imager in visible and near-infrared (NIR) wavelength bands, RADMON is an energetic particle detector and EPB is a de-orbiting technology demonstration payload. The platform was designed to accommodate multiple payloads while ensuring sufficient data, power, radio, mechanical and electrical interfaces. The design strategy of platform and payload subsystems consists of in-house development and commercial subsystems. The CubeSat Assembly, Integration & Test (AIT) followed Flatsat -- Engineering-Qualification Model (EQM) -- Flight Model (FM) model philosophy for qualification and acceptance.The paper briefly describes the design approach of platform and payload subsystems, their integration and test campaigns, and spacecraft launch. The paper also describes the ground segment & services that were developed by the Aalto-1 team.</p

    FORESAIL-1 cubesat mission to measure radiation belt losses and demonstrate de-orbiting

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    Abstract Today, the near-Earth space is facing a paradigm change as the number of new spacecraft is literally sky-rocketing. Increasing numbers of small satellites threaten the sustainable use of space, as without removal, space debris will eventually make certain critical orbits unusable. A central factor affecting small spacecraft health and leading to debris is the radiation environment, which is unpredictable due to an incomplete understanding of the near-Earth radiation environment itself and its variability driven by the solar wind and outer magnetosphere. This paper presents the FORESAIL-1 nanosatellite mission, having two scientific and one technological objectives. The first scientific objective is to measure the energy and flux of energetic particle loss to the atmosphere with a representative energy and pitch angle resolution over a wide range of magnetic local times. To pave the way to novel model - in situ data comparisons, we also show preliminary results on precipitating electron fluxes obtained with the new global hybrid-Vlasov simulation Vlasiator. The second scientific objective of the FORESAIL-1 mission is to measure energetic neutral atoms (ENAs) of solar origin. The solar ENA flux has the potential to contribute importantly to the knowledge of solar eruption energy budget estimations. The technological objective is to demonstrate a satellite de-orbiting technology, and for the first time, make an orbit manoeuvre with a propellantless nanosatellite. FORESAIL-1 will demonstrate the potential for nanosatellites to make important scientific contributions as well as promote the sustainable utilisation of space by using a cost-efficient de-orbiting technology.Peer reviewe
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