Full PIC simulation of a first ACHIP experiment @ SINBAD

In laser illuminated dielectric accelerators (DLA) high acceleration gradients can be achieved due to high damage thresholds of the materials at optical frequencies. This is a necessity for developing more compact particle accelerator technologies. The Accelerator on a CHip International Program (ACHIP) funded by the Gordon and Betty Moore Foundation is researching such devices. DESY Hamburg is part of the collaboration. The dedicated accelerator research facility SINBAD is particularly well suited for DLA experiments at relativistic electron energies. High quality beams and short bunch lengths are anticipated from the ARES linac which is currently under construction at SINBAD. The aim of the experiment is the injection of a short electron bunch from the ARES linac into a DLA. In this study the results of one of the first possible experiments at the facility are estimated via a combination of particle-in-cell (PIC) and tracking simulations. ASTRA is used to simulate an electron bunch from the ARES linac at a suitable working point. The dielectric part of the setup will be simulated using the PIC code from CST Particle Studio incorporating the retrieved bunch from the ASTRA simulation. The energy spectra of the electron bunches are calculated as would be measured from a spectrometer dipole with and without the laser fields

Vergleichende Wertung von Mikro- und Makrometastasen in axillären Sentinel- und non-Sentinel Lymphknoten bei Frauen mit Mammakarzinom

Die SLN-Biopsie hat sich als diagnostische Möglichkeit bei Patienten mit Mammakarzinom und klinisch unauffälligem Lymphknotenstatus etabliert. Mit einer zunehmend detaillierten Aufarbeitung ist es möglich, histopathologisch kleinste Lymphknotenmetastasen zu detektieren. Der Lymphknotenstatus hat einen wichtigen Stellenwert für die weitere Prognose des Krankheitsverlaufs und die Therapieplanung. Unter anderem ist er beispielsweise für die Wahl der adjuvanten Chemotherapie entscheidend. Sowohl die klinische Relevanz, als auch die prognostische Bedeutung insbesondere von sehr kleinen Metastasen im axillären SLN sind weiterhin diskussionswürdig. In der vorliegenden Dissertation mit dem mit dem Titel „Vergleichende Wertung von Mikro- und Makrometastasen in axillären Sentinel- und non-Sentinel Lymphknoten bei Frauen mit Mammakarzinom“ handelt es sich um eine retrospektive Analyse von 599 Patientinnen mit Mammakarzinom, bei denen eine SLN-Biopsie durchgeführt wurde. Die detektierten Mikro- und Makrometastasen in SLN und in non-SLN wurden in ihrer Häufigkeit deskriptiv mit spezifischen Patientinnen- und Tumorcharakteristika analysiert. Mit Hilfe dieser Daten erscheint es möglich, das Risiko für eine weitergehende Metastasierung in den axillären Lymphknoten einzugrenzen und diese Erkenntnis in das individuelle Therapiekonzept für die Patientin einzubinden. Abschließend kann festgestellt werden, dass Prognosen für das Auftreten von unterschiedlichen Größen der Metastasen in SLN existieren.Mit den ausgewerteten Daten konnten signifikante Häufigkeiten erarbeitet werden, mit denen es möglich ist, das Risiko für eine Metastasierung besser vorherzusagen. Dabei scheinen einige der erhobenen Patientencharakteristika signifikant häufig nachweisbar. Mikrometastasen lassen sich signifikant häufiger bei den Patientinnen in der jüngeren Altersgruppe von 36 bis 49 Jahren nachweisen. Zeigt sich ein erhöhtes Vorliegen von Östrogenrezeptoren, treten signifikant häufiger SLN mic auf. Im Stadium GII des Primärtumors besteht ein signifikant hohes Risiko für SLN mic. Außerdem findet sich ein signifikant hohes Risiko für SLN mic im Stadium T1b des Primärtumors. Das Auftreten von Mikrometastasen im SLN nimmt bis zum Stadium T1c des Primarius zu, es wird jedoch dann, bei weiterer Größenzunahme des Primärtumors, durch das erhöhte Vorkommen von Makrometastasen abgelöst. Dies kann durch ein signifikant erhöhtes Auftreten für SLN mak im Stadium T2 des Primärtumors übereinstimmend bestätigt werden. Abschließend kann festgehalten werden, dass GII und lobuläre Primärtumore rein statistisch die höchste Wahrscheinlichkeit für Mikrometastasen haben. GI und GII differenzierte Tumore zeigen eher Mikrometastasen als GIII Tumore und diese eher eine Makrometastasierung. Je größer die Metastasen im SLN sind, desto höher ist das Risiko für weitere Metastasen in der SAD. Mit einer 17 prozentigen Metastasierungswahrscheinlichkeit nach SLN mic gegenüber einer 46,8 prozentigen Metastasierungswahrscheinlichkeit nach SLN mak ist das Risiko für weitere Metastasen nach Makrometastasen im SLN signifikant erhöht. Dieses Ergebnis stimmt mit den aktuellen Therapieleitlinien überein

Simulations and plans for possible DLA experiments at SINBAD

In this work we present the outlines of possible experiments for dielectric laser acceleration (DLA) of ultra-short relativistic electron bunches produced by the ARES linac, currently under construction at the SINBAD facility (DESY Hamburg). The experiments are to be performed as part of the Accelerator on a Chip International Program (ACHIP), funded by the Gordon and Betty Moore Foundation. At SINBAD we plan to test the acceleration of already pre-accelerated relativistic electron bunches in laser-illuminated dielectric grating structures. We present outlines of both the acceleration of ultra-short single bunches, as well as the option to accelerate phase-synchronous sub-fs microbunch trains. Here the electron bunch is conditioned prior to the injection by interaction with an external laser field in an undulator. This generates a sinusoidal energy modulation that is transformed into periodic microbunches in a subsequent chicane. The phase synchronization is achieved by driving both the modulation process and the DLA with the same laser pulse. In addition to the conceptual layouts and plans of the experiments we present start-to-end simulation results for different ARES working points.Comment: EAAC'17 conference proceeding

Renal dimensions measured by ultrasonography in children: variations as a function of the imaging plane and patient position

The purpose of this study was to determine the effect of patient positioning on sonographic renal measurements and to test if the patient position alters the three-dimensional shape of the kidneys. The maximum longitudinal renal length and transverse renal width and depth were measured in the supine and prone position in 100 children (200 kidneys). Age ranged from 6 months to 16 years (mean age 5 years). The results were compared for statistically significant differences. The maximum measured longitudinal renal length was statistically significantly larger in the supine than in the prone position (supine position, left: 8.0cm; right: 7.7cm; prone position, left: 7.9cm, right: 7.6cm; P0.001) and renal volume (P>0.001) in the supine vs. prone positions. Our results show that position-induced reshaping of the kidneys is unlikely to be responsible for the discrepancy in maximum longitudinal renal measurements comparing supine with prone positions. Position-dependent changes in the degree of filling of the renal calyces and pelvis as well as errors in caliper distance measurements for the different scan depths (supine vs. prone) are more likely to be responsible for the encountered differences. Consequently, we recommend to add prone renal length measurements in addition to the supine measurements. In follow-up examinations, renal length measurements should only be compared that have been collected in the same patient positio

Solitary infantile choriocarcinoma of the liver: MRI findings

Infantile hepatic choriocarcinoma is a rare, highly malignant germ-cell tumour believed to result from a choriocarcinoma of the placenta that spreads to the child. Most infants present with a characteristic clinical picture of anaemia, hepatomegaly and precocious puberty. Imaging findings, including conventional MRI, may be non-specific. To improve the accuracy of diagnosis, we present the imaging findings of contrast-enhanced dynamic MRI in a 4.5-month-old boy with infantile hepatic choriocarcinom

Pre- and postnatal imaging of a girl with a cloacal variant

We describe the prenatal MR findings in a 29-week fetus with a cloacal variant (urogenital sinus and anterior placed anus) in combination with an enlarged clitoris and urethral duplication and correlate them with postnatal imaging. Fetal MR imaging permits the diagnosis and characterization of cloacal and urogenital sinus malformations in utero. This information may guide pre-, peri- and postnatal managemen

Estética do futebol: Brasil vs. Alemanha

In September of 1997, a group of German and Brazilian literary critics met at the University of São Paulo, in order to comment on the aesthetics of two great soccer schools. As our "basic text" we chose the match Germany vs Brazil (final score: 3 : 3; half-time score: 0 : 3), which took place in Washington, in June 1993, between the two tripte World Champions. Hans Ulrich Gumbrecht (Stanford University) proposed a philosophical reflection on football/Fußball, combined with a comparative analysis of soccer and American football. In both modalities he identified the magic phenomenon of "production of presence", which expresses itself through three functions: the ontological function (action vs nothing), the "epiphany of form" (the touch of genius) and the oscillation between finality and telos (linked to the mise-en-scène of intention and contingency). These three functions manifest themselves in both American football and soccer, but in different forms. Flávio Aguiar (University of Säo Paulo) pointed out the phenomenon of empty spaces and the occupation of space. Antonio Medina (University of São Paulo) contrasted the somewhat ontologic character of American football with the mimetic character of soccer, especially as played in Brazil, where the paradigm of masters and slaves is still present. José Miguel Wisnik (University of São Paulo) elaborated on the dialectics of production of presence (resistance against interpretation, "no-hermeneutics") and production of sense. In his reply, Gumbrecht explained that the concepts of empty and occupied space imply religious allusions (transcendental emptiness). Willi Bolle (University of São Paulo) raised the question of the extent to which the issue of aesthetics, seen from the perspective of American football and soccer, must be totally reconsidered.Im September 1997 trafen sich deutsche und brasilianische Literaturwissenschaftler in der Universität São Paulo, um den Stil zweier großer Fußball-Schulen zu kommentieren. Als "Textgrundlage" hatten wir das Spiel Deutschland : Brasilien ausgewählt (Endstand: 3 : 3; Halbzeitstand: 0: 3), das im Juni 1993 in Washington zwischen den seinerzeit dreifachen Weltmeistern ausgetragen worden war. Hans Ulrich Gumbrecht (Universität Stanford) schlug eine philosophische Reflexion über den Fußball vor, verbunden mit einer vergleichenden Analyse des Soccer und des American Football. In beiden Ballspielarten beobachtet er das magische Phänomen der "Produktion von Gegenwart". Sie tritt in drei Arten von Funktionen zu Tage – ontologische Funktion (die Aktion gegen das Nichts), die "Epiphanie der Form" (der geniale Spielzug) und Spannung zwischen Finalität und Telos (oder auch Inszenierung von Intentionalität und Kontingenz) –, die sich sowohl im Football wie im Fußball beobachten lassen, aber in ganz verschiedener Zusammensetzung. Flávio Aguiar (Universität São Paulo) hob in seinem Kommentar das Phänomen der leeren Spielräume und der Besetzung des Raums hervor. Antonio Medina (Universität São Paulo) setzte dem eher ontologischen Charakter des American Football den mimetischen Charakter des Fußballs entgegen, der (zumindest in Brasilien) von dem Verhältnis zwischen Herren und Sklaven affiziert wird. Jose Miguel Wisnik (Universität São Paulo) vertiefte die Dialektik zwischen der Herstellung von Gegenwart (Widerstand gegen Interpretation, negative Hermeneutik) und der Produktion von Sinn. In seiner Antwort erläuterte Gumbrecht, dass die Begriffe des leeren und des besetzten Raumes religiöse Tonalitäten mit sich bringen (die transzendentale Leere). Willi Bolle (Universität São Paulo) stellte die Frage, inwiefern eine aus der Perspektive des Massensports Fußball entworfene Ästhetik dazu führen kann, den Begriff der Ästhetik neu zu denken

Developmental nasal midline masses in children: neuroradiological evaluation

Developmental nasal midline masses in children are rare lesions. Neuroimaging is essential to characterise these lesions, to determine the exact location of the lesion and most importantly to exclude a possible intracranial extension or connection. Our objective was to evaluate CT and MRI in the diagnosis of developmental nasal midline masses. Eleven patients (mean age 4.5years) with nasal midline masses were examined by CT and MRI. Neuroimaging was evaluated for (a) lesion location/size, (b) indirect (bifid or deformed crista galli, widened foramen caecum, defect of the cribriform plate) and direct (identification of intracranially located lesion components or signal alterations) imaging signs of intracranial extension, (c) secondary complications and (d) associated malformations. Surgical and histological findings served as gold standard. Nasal dermoid sinus cysts were diagnosed in 9 patients. One patient was diagnosed with an meningocele and another patient with a nasal glioma. Indirect CT and MRI signs correlated with the surgical results in 10 of 11 patients. Direct CT findings correlated with surgery in all patients, whereas the direct MRI signs correlated in 9 of 11 patients. In 2 patients MRI showed an intracranial signal alteration not seen on CT. Neuroimaging corrected the clinical diagnosis in 1 patient. One child presented with a meningitis. In none of the patients was an associated malformation diagnosed. Intracranial extension is equally well detected by CT and MRI using indirect imaging signs. Evaluating the direct imaging signs, MRI suspected intracranial components in 2 patients without a correlate on CT. This could represent an isolated intracranial component that got undetected on CT and surgery. In 9 patients CT and MRI matched the surgical findings. The MRI did not show any false-negative results. These results in combination with the multiplanar MRI capabilities, the different image contrasts that can be generated by MRI and the lack of radiation favour the use of MRI as primary imaging tool in these young patients in which the region of imaging is usually centred on the radiosensitive eye lense

Burkitt's lymphoma with bilateral cavernous sinus and mediastinal involvement in a child

We report a 12-year-old boy who presented with incomplete right ophthalmoplegia, exophthalmos and headache. Initial CT and MRI revealed a mass in the right cavernous sinus. During tumour work-up, CT identified additional tumour within the mediastinum. Biopsy of the mediastinal lesion identified Burkitt's lymphoma. We report on this case because radiologists and clinicians should be alerted to identify sites of primary Burkitt's lymphoma outside of the central nervous system if clinical symptoms indicate, or imaging shows, CNS lesions. Primary CNS involvement in Burkitt's lymphoma is rar

FINEX: A Fast Index for Exact & Flexible Density-Based Clustering (Extended Version with Proofs)*

Density-based clustering aims to find groups of similar objects (i.e., clusters) in a given dataset. Applications include, e.g., process mining and anomaly detection. It comes with two user parameters ({\epsilon}, MinPts) that determine the clustering result, but are typically unknown in advance. Thus, users need to interactively test various settings until satisfying clusterings are found. However, existing solutions suffer from the following limitations: (a) Ineffective pruning of expensive neighborhood computations. (b) Approximate clustering, where objects are falsely labeled noise. (c) Restricted parameter tuning that is limited to {\epsilon} whereas MinPts is constant, which reduces the explorable clusterings. (d) Inflexibility in terms of applicable data types and distance functions. We propose FINEX, a linear-space index that overcomes these limitations. Our index provides exact clusterings and can be queried with either of the two parameters. FINEX avoids neighborhood computations where possible and reduces the complexities of the remaining computations by leveraging fundamental properties of density-based clusters. Hence, our solution is effcient and flexible regarding data types and distance functions. Moreover, FINEX respects the original and straightforward notion of density-based clustering. In our experiments on 12 large real-world datasets from various domains, FINEX frequently outperforms state-of-the-art techniques for exact clustering by orders of magnitude