1,337 research outputs found
Malignant glioma after ependymoma: an unusual secondary malignancy
Purpose : Secondary malignancies (SM) are a known long-‐term problem in children surviving brain tumors. We report on two unusual cases of SM observed after treatment of ependymoma. Case reports : 1. The first case is a female survivor of a low-‐grade ependymoma (Grade II). She had been treated at the age of 3 months with surgery and chemotherapy. A relapse of the primary tumor happened two years later, which was completely removed and treated with local radiotherapy to the posterior fossa. Fifteen years after the first cancer, she developed a pontine glioma near the location of the previous radiotherapy. 2. The second case is a femal survivor of an ependymoma (Grade III) which was removed and irradiated when she was 4 years old. The child developed a pontine glioma near the location of the previous radiotherapy ten years after the diagnosis of the first cancer. Further extension of the disease showed after biopsy PNET-‐ like features. Both patients passed away.
Discussion and Conclusion : Second malignant neoplasia is a rare phenomenon and this risk should not overshadow the great success in treating cancer of childhood. Among the studied risk factors, young age and radiotherapy are well established. The reported patients were followed annually to ensure their remission and both developed symptoms and an unusual unreported secondary cancer a few months after the annual monitoring that was considered as normal. This issue highlights the complexity of monitoring cancer survivors and raises the question of the best way for their long-‐term follow-‐up
Spatiotemporal evolution of runaway electrons from synchrotron images in Alcator C-Mod
In the Alcator C-Mod tokamak, relativistic runaway electron (RE) generation
can occur during the flattop current phase of low density, diverted plasma
discharges. Due to the high toroidal magnetic field (B = 5.4 T), RE synchrotron
radiation is measured by a wide-view camera in the visible wavelength range
(~400-900 nm). In this paper, a statistical analysis of over one thousand
camera images is performed to investigate the plasma conditions under which
synchrotron emission is observed in C-Mod. In addition, the spatiotemporal
evolution of REs during one particular discharge is explored in detail via a
thorough analysis of the distortion-corrected synchrotron images. To accurately
predict RE energies, the kinetic solver CODE [Landreman et al 2014 Comput.
Phys. Commun. 185 847-855] is used to evolve the electron momentum-space
distribution at six locations throughout the plasma: the magnetic axis and flux
surfaces q = 1, 4/3, 3/2, 2, and 3. These results, along with the
experimentally-measured magnetic topology and camera geometry, are input into
the synthetic diagnostic SOFT [Hoppe et al 2018 Nucl. Fusion 58 026032] to
simulate synchrotron emission and detection. Interesting spatial structure near
the surface q = 2 is found to coincide with the onset of a locked mode and
increased MHD activity. Furthermore, the RE density profile evolution is fit by
comparing experimental to synthetic images, providing important insight into RE
spatiotemporal dynamics
Rolle der Zytologie in der hämatopathologischen Diagnostik
Zusammenfassung: Die Zytologie stellt ein wichtiges diagnostisches Instrument in der täglichen Praxis der Hämatopathologie dar. Durch den zytologisch erfolgten Nachweis nichthämatologischer Ursachen einer Knotenbildung (z.B. Speicheldrüsenneoplasien, Tuberkulose, Melanom- oder Karzinommetastasen) besteht seltener die Notwendigkeit einer chirurgischen Exzision. Die kombinierte Anwendung morphologischer, immunphänotypischer sowie molekularer Analysen und der fachliche Austausch machen diese Untersuchungstechnik sicher. Somit stellt die zytologische Untersuchung in verschiedensten Situationen eine Alternative zur Exzisionsbiopsie dar - auch bei primären hämatologischen Erkrankungen und insbesondere bei Rezidive
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Swiss inward FDI and its policy context
Switzerland has constantly sought to build an open economy in which foreign actors have been a crucial element of the economic growth process. The quality of the business environment, the central geographic location in Europe and the stability of the political, legal and social system have traditionally attracted a relatively high-level of inward foreign direct investment (IFDI) to the country. However, this success should not be taken for granted. The current economic crisis and the globalization of the world economy are challenging the attractiveness of Switzerland as a FDI location. In a context of fierce competition among countries to attract FDI, Switzerland has constantly to improve the quality of its business environment in order to remain a competitive location for foreign investors
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Swiss outward FDI and its policy context
Switzerland's outward foreign direct investment (OFDI) has traditionally been relatively high. The small size of the country, a natural resources shortage and the geographical location at the heart of Europe induced Swiss firms constantly to expand their activities abroad. This exposure to global markets is reflected in its OFDI. Although the global financial and economic crisis pushed the country into a recession and triggered a sharp decrease of OFDI flows, the Swiss OFDI stock continued to grow in 2008 and 2009. Thanks to a well-balanced economic structure based on innovation and knowledge and coherent government policies, Switzerland weathered, at least in the short-term, the effects of the crisis and set the path for a sustainable growth of OFDI
Scaling laws for jets of single cavitation bubbles
Fast liquid jets, called micro-jets, are produced within cavitation bubbles
experiencing an aspherical collapse. Here we review micro-jets of different
origins, scales and appearances, and propose a unified framework to describe
their dynamics by using an anisotropy parameter , representing a
dimensionless measure of the liquid momentum at the collapse point (Kelvin
impulse). This parameter is rigorously defined for various jet drivers,
including gravity and nearby boundaries. Combining theoretical considerations
with hundreds of high-speed visualisations of bubbles collapsing near a rigid
surface, near a free surface or in variable gravity, we classify the jets into
three distinct regimes: weak, intermediate and strong. Weak jets
() hardly pierce the bubble, but remain within it throughout the
collapse and rebound. Intermediate jets () pierce the
opposite bubble wall close to the last collapse phase and clearly emerge during
the rebound. Strong jets () pierce the bubble early during the
collapse. The dynamics of the jets is analysed through key observables, such as
the jet impact time, jet speed, bubble displacement, bubble volume at jet
impact and vapour-jet volume. We find that, upon normalising these observables
to dimensionless jet parameters, they all reduce to straightforward functions
of , which we can reproduce numerically using potential flow theory. An
interesting consequence of this result is that a measurement of a single
observable, such as the bubble displacement, suffices to estimate any other
parameter, such as the jet speed. Remarkably, the dimensionless parameters of
intermediate and weak jets only depend on , not on the jet driver. In
the same regime, the jet parameters are found to be well approximated by
power-laws of , which we explain through analytical arguments
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