420 research outputs found
The VITROVAC Cavity for the TERA/PIMMS Medical Synchrotron
A proton and light-ion medical synchrotron is characterised by a large frequency swing for the RF between the injection and the top energy. For this purpose, a VITROVAC®-loaded RF cavity has been developed for the Proton-Ion Medical Machine Study (PIMMS) at CERN, and for TERA, the Italian project of a proton and light-ion synchrotron for cancer therapy, based on the PIMMS study. The main features are a large frequency swing, particularly extended to the low frequency range, a very large relative permeability and a low Q factor. The total power needed is less than 100 kW, while a very small bias power is required for the frequency tuning. The main mechanical characteristics are compactness (less than 1.5 m), and simplicity of construction. As a result, the requirements of the medical synchrotron are comfortably satisfied, namely: 0.4 to 3 MHz swing, 3 kV peak voltage at a repetition rate of less than 1 s
What determines auditory similarity? The effect of stimulus group and methodology.
Two experiments on the internal representation of auditory stimuli compared the pairwise and grouping methodologies as means of deriving similarity judgements. A total of 45 undergraduate students participated in each experiment, judging the similarity of short auditory stimuli, using one of the methodologies. The experiments support and extend Bonebright's (1996) findings, using a further 60 stimuli. Results from both methodologies highlight the importance of category information and acoustic features, such as root mean square (RMS) power and pitch, in similarity judgements. Results showed that the grouping task is a viable alternative to the pairwise task with N > 20 sounds whilst highlighting subtle differences, such as cluster tightness, between the different task results. The grouping task is more likely to yield category information as underlying similarity judgements
Topoisomerase II alpha and TLE3 as predictive markers of response to anthracycline and taxane-containing regimens for neoadjuvant chemotherapy in breast cancer.
PURPOSE: Anthracyclines and taxanes are considered the standard for neoadjuvant chemotherapy of breast cancer, although they are often associated with serious side effects and wide variability of individual response. In this study, we analyzed the value of topoisomerase II alpha (TOP2A) and transducin-like enhancer of split 3 (TLE3) as predictive markers of response to therapy with anthracyclines and taxanes. MATERIALS AND METHODS: TOP2A and TLE3 protein expressions were evaluated using immunohistochemistry on 28 samples, obtained by core needle biopsy in patients with locally advanced breast carcinoma, subsequently subjected to epirubicin- and paclitaxel-based neoadjuvant chemotherapy. The immunohistochemical staining was correlated with the clinical response measured by the tumor size reduction evaluated by breast magnetic resonance imaging, prior and after chemotherapy, and by pathologic evaluation of the surgical specimen. RESULTS: Neoadjuvant chemotherapy achieved a size reduction in 26/28 tumors (92.9%), with an average percentage decrease of 45.6%. A downstaging was achieved in 71.4% of the cases of locally advanced carcinoma. TOP2A positivity was correlated with a greater reduction in tumor diameter (P=0.06); negative staining for TLE3 was predictive of a better response to neoadjuvant chemotherapy (P=0.07). A higher reduction in tumor diameter (P=0.03) was also found for tumors that were concurrently TLE3-negative and TOP2A-positive. CONCLUSION: TOP2A and TLE3 showed a correlation with response to neoadjuvant chemotherapy. While TOP2A is a well-known marker of response to anthracyclines-based chemotherapy, TLE3 is a new putative predictor of response to taxanes. Data from the current study suggest that TOP2A and TLE3 warrant further investigation in a larger series as predictors of response to neoadjuvant chemotherapy for locally advanced breast carcinoma
Preventing acute infection in total hip prostheses implanted after external fixation of the femur: is there a need for a staged procedure?
We report two cases of acute infection of an uncemented femoral component in a hip prosthesis implanted after external fixation of a femoral fracture. In both cases, the surgical access did not cross over the pin scars. When the prosthesis was implanted the stem crossed one or more pin tracts. The preoperative clinical examination, laboratory tests and bone scintigraphy with marked granulocytosis did not show signs of local infection in either case. We suggest that every patient destined to receive a prosthesis after external fixation should be treated with a staged procedure, the first step being excision of the soft tissues around the pin tracts and curettage or drilling of the bony holes, followed by prosthesis implant
Vocal imitations and the identification of sound events
International audienceIt is commonly observed that a speaker vocally imitates a sound that she or he intends to communicate to an interlocutor. We report on an experiment that examined the assumption that vocal imitations can e ffectively communicate a referent sound, and that they do so by conveying the features necessary for the identifi cation of the referent sound event. Subjects were required to sort a set of vocal imitations of everyday sounds. The resulting clusters corresponded in most of the cases to the categories of the referent sound events, indicating that the imitations enabled the listeners to recover what was imitated. Furthermore, a binary decision tree analysis showed that a few characteristic acoustic features predicted the clusters. These features also predicted the classi fication of the referent sounds, but did not generalize to the categorization of other sounds. This showed that, for the speaker, vocally imitating a sound consists of conveying the acoustic features important for recognition, within the constraints of human vocal production. As such vocal imitations prove to be a phenomenon potentially useful to study sound identifi cation
Spatially resolved X-ray excited optical luminescence
Spatially resolved luminescence distributions in semiconductor heterostructures were investigated by core level excitation using hard X-ray (sub-) microbeams. Compact and mobile XEOL instruments have been developed and well adapted on the hard X-ray beamline ID22 of the European Synchrotron Radiation Facility for different wavelength collection ranges: UV-VIS and NIR. Linked by multimode optical fibers, their special designs provide precise scanning microscopy and allow easy access for multiple detection modes. Based on the hard X-ray microprobe station of ID22, details of the equipments, spectral data and representative examples are briefly described. Data collections from InAs and InGaN quantum heterostructures support the excellent performance of the optical devices. © 2011 Elsevier B.V. All rights reserved.This work was partially supported by the NANOWIRING Marie Curie ITN (EU project No. PITN-GA-2010-265073).Peer Reviewe
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Discovery of Unusual Minerals in Paleolithic Black Pigments from Lascaux (France) and Ekain (Spain)
Analyses of archaeological materials aim to rediscover the know-how of Prehistoric people by determining the nature of the painting matter, its preparation mode, and the geographic origin of its raw materials. This study deals with identification of manganese oxides in black pigments by micro-XANES (X-ray absorption near-edge structure) based on previous TEM (transmission electron microscopy) studies. Complex mixtures of the manganese oxides studied are present in some of mankind's oldest known paintings, namely those from the caves of Lascaux (Dordogne, France) and Ekain (Basque country, Spain). Scarce manganese oxide minerals, including groutite, hausmannite, and manganite, were found for the first time in Paleolithic art at these archaeological sites. Because there are no known deposits of such minerals in these areas, more distant origins and trade routes are inferred. The closest known Mn-rich geological province for Lascaux is the central Pyrenees, which is {approx} 250 km from the Dordogne area
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