Nuclear Emulsion Film Detectors for Proton Radiography: Design and Test of the First Prototype

Proton therapy is nowadays becoming a wide spread clinical practice in cancer therapy and sophisticated treatment planning systems are routinely used to exploit at best the ballistic properties of charged particles. The information on the quality of the beams and the range of the protons is a key issue for the optimization of the treatment. For this purpose, proton radiography can be used in proton therapy to obtain direct information on the range of the protons, on the average density of the tissues for treatment planning optimization and to perform imaging with negligible dose to the patient. We propose an innovative method based on nuclear emulsion film detectors for proton radiography, a technique in which images are obtained by measuring the position and the residual range of protons passing through the patient's body. Nuclear emulsion films interleaved with tissue equivalent absorbers can be fruitfully used to reconstruct proton tracks with very high precision. The first prototype of a nuclear emulsion based detector has been conceived, constructed and tested with a therapeutic proton beam at PSI. The scanning of the emulsions has been performed at LHEP in Bern, where a fully automated microscopic scanning technology has been developed for the OPERA experiment on neutrino oscillations. After track reconstruction, the first promising experimental results have been obtained by imaging a simple phantom made of PMMA with a step of 1 cm. A second phantom with five 5 x 5 mm^2 section aluminum rods located at different distances and embedded in a PMMA structure has been also imaged. Further investigations are in progress to improve the resolution and to image more sophisticated phantoms.Comment: Presented at the 11th ICATPP Conference on Astroparticle, Particle, Space Physics, Detectors and Medical Physics Applications, Como (Italy), October 200

Biparametrische versus multiparametrische MRT der Prostata im Rahmen der Planung einer roboterassistierten Fusionsbiopsie

Zentrale Fragestellung dieser Dissertation ist der Stellenwert der Kontrastmittel-gestützten Sequenz (DCE) in der multiparametrischen Befundung im Hinblick auf die Diagnostik maligner Läsionen der Prostata. Innerhalb des „Prostate Imaging Reporting and Data System“ (PI-RADS) spielt die Kontrastmitteldynamik für die Einordnung von Läsionen eine Rolle, die in der peripheren Zone liegen und bei denen die Diffusionsbildgebung als PI-RADS Kategorie 3 eingeordnet wurde. Wenn die Kontrastmitteldynamik für solche Läsionen positiv gewertet wird, erfolgt ein Upgrade in einen PI-RADS 4 Befund, womit eine höhere Wahrscheinlichkeit für ein klinisch signifikantes Prostatakarzinom angegeben wird und damit die Erwägung einer bioptischen Sicherung verstärkt wird. Neuere Studien stellen jedoch die Rolle der DCE zur Diskussion, auch mit Blick auf Kontrastmittel-assoziierte Nebenwirkungen und Risiken sowie Kostenaspekte und Umweltaspekte. Eine mögliche Indikation für den Verzicht auf die DCE stellt ein klinisches Hochrisikokollektiv dar. Daher wurde in dieser Arbeit der Ansatz einer multiparametrischen Bildgebung (mpMRT) mit dem einer biparametrischen (bpMRT) ohne DCE vor geplanter roboterassistierter Fusionsbiopsie retrospektiv verglichen

cenários em disputa

O objetivo deste texto versa em problematizar a concepção de família socialmente legitimada e sua incidência sobre a formulação das políticas sociais em um cenário apregoado pelas ideologias conservadoras e neoliberais. Com as análises realizadas pelo presente texto, percebe-se que aspectos sócio-históricos do capitalismo vão moldando o conceito de família e que este, consequentemente, incide sobre o modelo de política social. Na mesma proporção, as políticas sociais vão moldando e disseminando concepções de família, tendo em vista que são importantes aportes do Estado na reprodução do capitalismo e no fortalecimento da sociedade de classes

A Renormalization Proof of the KAM Theorem for Non-Analytic Perturbations

We shall use a Renormalization Group (RG) scheme in order to prove the classical KAM result in the case of a non-analytic perturbation (the latter will be assumed to have continuous derivatives up to a sufficiently large order). We shall proceed by solving a sequence of problems in which the perturbations are analytic approximations of the original one. We shall finally show that the sequence of the approximate solutions will converge to a differentiable solution of the original problem.Comment: 33 pages, no figure

The Impacts of Modeling Choices on the Inference of the Circumgalactic Medium Properties from Sunyaev-Zeldovich Observations

As the signal-to-noise of Sunyaev-Zeldovich (SZ) cross-correlation measurements of galaxies improves our ability to infer properties about the circumgalactic medium (CGM), we will transition from being limited by statistical uncertainties to systematic uncertainties. Using thermodynamic profiles of the CGM created from the IllustrisTNG (The Next Generation) simulations we investigate the importance of specific choices in modeling the galaxy sample. These choices include different sample selections in the simulation (stellar vs. halo mass, color selections) and different fitting models (matching by the shape of the mass distribution, inclusion of a two-halo term). We forward model a mock galaxy sample into projected SZ observable profiles and fit these profiles to a generalized Navarro-Frenk-White profile using forecasted errors of the upcoming Simons Observatory experiment. We test the number of free parameters in the fits and show that this is another modeling choice that yields different results. Finally, we show how different fitting models can reproduce parameters of a fiducial profile, and show that the addition of a two-halo term and matching by the mass distribution of the sample are extremely important modeling choices to consider.Comment: 22 pages, 9 figures, comments welcom

A novel blue fluorescent chlorophyll catabolite accumulates in senescent leaves of the peace lily and indicates a split path of chlorophyll breakdown

AbstractColorless, non-fluorescent Chl-catabolites (NCCs) are the typical, ubiquitous products of chlorophyll (Chl)-breakdown in senescent leaves. However, a fluorescent Chl-catabolite (FCC) accumulated in de-greened leaves of Spathiphyllum wallisii (Peace Lily), which showed a weak blue luminescence. The FCC, named Sw-FCC-62, was ‘hypermodified’ with an unprecedented 6-(2-[3,4-dihydroxy-phenyl]-ethyl)-β-glucopyranosidyl ester at the propionyl group. Such esters stabilize FCCs against their typical and rapid, spontaneous isomerization to NCCs. Chl-breakdown in Sp. wallisii thus branches off from the ‘common’ path in leaves, and furnishes unique and ‘persistent’ FCCs. Our findings on ‘hypermodified’ FCCs also call for attention as to possible physiological roles of Chl-catabolites in plants

Cross-cultural adaptation and translation into Brazilian Portuguese of the instruments Sick Control One Stone Fat Food Questionnaire (SCOFF), Eating Disorder Examination Questionnaire (EDE-Q) and Clinical Impairment Assessment Questionnaire (CIA)

Introduction: Eating disorders (EDs) affect up to 13% of young people and are associated with significant morbidity and mortality. Nevertheless, important, internationally recognized instruments for brief ED screening (Sick Control One Stone Fat Food Questionnaire [SCOFF]), symptom severity assessment and diagnosis (Eating Disorder Examination Questionnaire [EDE-Q]) and assessment of ED-associated psychosocial impairment (Clinical Impairment Assessment Questionnaire [CIA]) were not yet available in Brazilian Portuguese. Our objective was to perform the cross-cultural adaptation and translation into Brazilian Portuguese of the instruments SCOFF, EDE-Q and CIA. Method: The process involved a series of standardized steps, as well as discussions with experts. First, the relevance and adequacy of the scales’ items to our culture and population were extensively discussed. Then, two independent groups translated the original documents, creating versions that were compared. With the participation of external ED experts (i.e., who did not take part in the translation process), synthesized versions were produced. The syntheses were then applied to a focal group of patients with ED (n = 8). After that step, a preliminary version of the three scales in Brazilian Portuguese was produced and sent for back-translation by two English native speakers, who worked independently. A synthesis of the back-translations, along with the preliminary versions in Brazilian Portuguese, were sent to the original authors. Results: The Brazilian Portuguese versions of SCOFF, EDE-Q and CIA were approved by the original authors and are now available for use. Conclusion: This study provides important tools for the ED research field in Brazil

Redox‐Mediated Amination of Pyrogallol‐Based Polyphenols

Flavonoids are known to covalently modify amyloidogenic peptides by amination reactions. The underlying coupling process between polyphenols and N-nucleophiles is assessed by several in vitro and in silico approaches. The coupling reaction involves a sequence of oxidative dearomatization, amination, and reductive amination (ODARA) reaction steps. The C6-regioselectivity of the product is confirmed by crystallographic analysis. Under aqueous conditions, the reaction of baicalein with lysine derivatives yields C−N coupling as well as hydrolysis products of transient imine intermediates. The observed C−N coupling reactions work best for flavonoids combining a pyrogallol substructure with an electron-withdrawing group attached to the C4a-position. Thermodynamic properties such as bond dissociation energies also highlight the key role of pyrogallol units for the antioxidant ability. Combining the computed electronic properties and in vitro antioxidant assays suggests that the studied pyrogallol-containing flavonoids act by various radical-scavenging mechanisms working in synergy. Multivariate analysis indicates that a small number of descriptors for transient intermediates of the ODARA process generates a model with excellent performance (r=0.93) for the prediction of cross-coupling yields. The same model has been employed to predict novel antioxidant flavonoid-based molecules as potential covalent inhibitors, opening a new avenue to the design of therapeutically relevant anti-amyloid compounds

A Chlorophyll-Derived Phylloxanthobilin Is a Potent Antioxidant That Modulates Immunometabolism in Human PBMC

Phyllobilins are natural products derived from the degradation of chlorophyll, which proceeds via a common and strictly controlled pathway in higher plants. The resulting tetrapyrrolic catabolites-the phyllobilins-are ubiquitous in nature;despite their high abundance, there is still a lack of knowledge about their physiological properties. Phyllobilins are part of human nutrition and were shown to be potent antioxidants accounting with interesting physiological properties. Three different naturally occurring types of phyllobilins-a phylloleucobilin, a dioxobilin-type phylloleucobilin and a phylloxanthobilin (PxB)-were compared regarding potential antioxidative properties in a cell-free and in a cell-based antioxidant activity test system, demonstrating the strongest effect for the PxB. Moreover, the PxB was investigated for its capacity to interfere with immunoregulatory metabolic pathways of tryptophan breakdown in human blood peripheral mononuclear cells. A dose-dependent inhibition of tryptophan catabolism to kynurenine was observed, suggesting a suppressive effect on pathways of cellular immune activation. Although the exact mechanisms of immunomodulatory effects are yet unknown, these prominent bioactivities point towards health-relevant effects, which warrant further mechanistic investigations and the assessment of the in vivo extrapolatability of results. Thus, phyllobilins are a still surprisingly unexplored family of natural products that merit further investigation