956 research outputs found
Electronic structure of C60 / graphite
We report temperature-dependent photoelectron spectra for a monolayer of C_60
adsorbed on HOPG, as well as C 1s x-ray absorption. This extends a previous
report which showed the close similarity between the spectrum of the HOMO for
the two-dimensional overlayer and that of C_60 in the gas phase. The present
work shows that intermolecular and molecule-substrate vibrations contribute
strongly to the spectral lineshape at room temperature. Thus, vibrational
effects are shown to be crucial for the proper understanding of photoelectron
spectra, and thus the charge transport properties, for C_60 in contact with
graphite and graphite-like materials.Comment: Proc. of the XV. Int. Winterschool on Electronic Properties of Novel
Materials, Kirchberg/Tirol, Austria, 200
Apoptotic cell death in the lactating mammary gland is enhanced by a folding variant of α-lactalbumin
Apoptosis is essential to eliminate secretory epithelial cells during the involution of the mammary gland. The environmental regulation of this process is however, poorly understood. This study tested the effect of HAMLET (human α-lactalbumin made lethal to tumor cells) on mammary cells. Plastic pellets containing HAMLET were implanted into the fourth inguinal mammary gland of lactating mice for 3 days. Exposure of mammary tissue to HAMLET resulted in morphological changes typical for apoptosis and in a stimulation of caspase-3 activity in alveolar epithelial cells near the HAMLET pellets but not more distant to the pellet or in contralateral glands. The effect was specific for HAMLET and no effects were observed when mammary glands were exposed to native a-lactalbumin or fatty acid alone. HAMLET also induced cell death in vitro in a mouse mammary epithelial cell line. The results suggest that HAMLET can mediate apoptotic cell death in mammary gland tissu
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Aspects of Trope in the Earliest Motets for the Assumption of the Virgin
The feast of the Assumption of the Virgin, observed annually on 15 August, was the most important saint's feast in the liturgical calendar of Notre Dame of Paris in the Middle Ages. In the thirteenth century, this occasion had a level of ceremonial and ritual splendor equaled only on Christmas, Easter, and Pentecost, for only these four feasts were given the highest liturgical rank, that of annuum festum or festum annuale, as it was variously termed in liturgical calendars at Notre Dame. Perhaps the most noteworthy finding of this study is that the earliest motets as tropes do not function in quite the same way as tropes themselves. We are familiar with tropes that make what is implicit in the thing troped more explicit in the trope itself, but these "tropic" motets do not work that way. Instead, they are like good children: they take their cue from their parents and do as the parent chants do. If the chant is unequivocally proper to the feast at hand, as in the case of the Alleluias, so are the offspring motets; if the chant manifests a more general theme, so do the motets. In the case of motets for the Virgin, the most striking feature is the pervasiveness of the idea of Mary as the Mother of Godthe Marian aspect of the Incarnation-whatever the specific feast may be
Image registration between MRI and spot mammograms for X-ray guided stereotactic breast biopsy : preliminary results
Carte sédimentologique et carte annexe du lagon de Nouvelle-Calédonie à 1/50 000 : feuille Nouméa
A Simple Ultrasound Based Classification Algorithm Allows Differentiation of Benign from Malignant Breast Lesions by Using Only Quantitative Parameters.
PURPOSE: We hypothesized that different quantitative ultrasound (US) parameters may be used as complementary diagnostic criteria and aimed to develop a simple classification algorithm to distinguish benign from malignant breast lesions and aid in the decision to perform biopsy or not. PROCEDURES: One hundred twenty-four patients, each with one biopsy-proven, sonographically evident breast lesion, were included in this prospective, IRB-approved study. Each lesion was examined with B-mode US, Color/Power Doppler US and elastography (Acoustic Radiation Force Impulse-ARFI). Different quantitative parameters were recorded for each technique, including pulsatility (PI) and resistive Index (RI) for Doppler US and lesion maximum, intermediate, and minimum shear wave velocity (SWVmax, SWVinterm, and SWVmin) as well as lesion-to-fat SWV ratio for ARFI. Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic performance of each quantitative parameter. Classification analysis was performed using the exhaustive chi-squared automatic interaction detection method. Results include the probability for malignancy for every descriptor combination in the classification algorithm. RESULTS: Sixty-five lesions were malignant and 59 benign. Out of all quantitative indices, maximum SWV (SWVmax), and RI were included in the classification algorithm, which showed a depth of three ramifications (SWVmax ≤ or > 3.16; if SWVmax ≤ 3.16 then RI ≤ 0.66, 0.66-0.77 or > 0.77; if RI ≤ 0.66 then SWVmax ≤ or > 2.71). The classification algorithm leads to an AUC of 0.887 (95 % CI 0.818-0.937, p < 0.0001), a sensitivity of 98.46 % (95 % CI 91.7-100 %), and a specificity of 61.02 % (95 % CI 47.4-73.5 %). By applying the proposed algorithm, a false-positive biopsy could have been avoided in 61 % of the cases. CONCLUSIONS: A simple classification algorithm incorporating two quantitative US parameters (SWVmax and RI) shows a high diagnostic performance, being able to accurately differentiate benign from malignant breast lesions and lower the number of unnecessary breast biopsies in up to 60 % of all cases, avoiding any subjective interpretation bias
Virtual Touch IQ elastography reduces unnecessary breast biopsies by applying quantitative "rule-in" and "rule-out" threshold values.
Our purpose was to evaluate Virtual Touch IQ (VTIQ) elastography and identify quantitative "rule-in" and "rule-out" thresholds for the probability of malignancy, which can help avoid unnecessary breast biopsies. 189 patients with 196 sonographically evident lesions were included in this retrospective, IRB-approved study. Quantitative VTIQ images of each lesion measuring the respective maximum Shear Wave Velocity (SWV) were obtained. Paired and unpaired, non-parametric statistics were applied for comparisons as appropriate. ROC-curve analysis was used to analyse the diagnostic performance of VTIQ and to specify "rule-in" and "rule-out" thresholds for the probability of malignancy. The standard of reference was either histopathology or follow-up stability for >24 months. 84 lesions were malignant and 112 benign. Median SWV of benign lesions was significantly lower than that of malignant lesions (p 98% with a concomitant significant (p = 0.032) reduction in false positive cases of almost 15%, whereas a "rule-in" threshold of 6.5 m/s suggested a probability of malignancy of >95%. In conclusion, VTIQ elastography accurately differentiates malignant from benign breast lesions. The application of quantitative "rule-in" and "rule-out" thresholds is feasible and allows reduction of unnecessary benign breast biopsies by almost 15%
A population-based, cross-sectional study of the prevalence and correlates of sedentary behaviour of adults with intellectual disabilities
Background:
High levels of sedentary behaviour have a negative impact on health and well-being. There is limited evidence on the prevalence and correlates of sedentary behaviour of adults with intellectual disabilities (ID).
Methods:
A population-based sample of adults with ID were invited to take part in a comprehensive health check programme. Demographic and health data were collected during a structured interview and physical examination. Screen time was used as a proxy measure of sedentary behaviour. Bivariate and multivariate statistical modelling examined correlates of screen time.
Results:
Fifty per cent of the 725 participants reported four or more hours of screen time per day. Male gender, higher levels of intellectual ability, mobility problems, obesity, not having hearing impairment and not having epilepsy were all significantly associated with higher screen time in the final multivariate model (R2 = 0.16; Hosmer–Lemeshow goodness of fit statistic P = 0.36).
Conclusions:
This is the first study to publish population-based data on the prevalence and correlates of sedentary behaviour in adults with ID. Compared with adults who do not have ID, adults with ID have higher levels, and different correlates, of sedentary behaviour. A better understanding of the social context of sedentary behaviour will inform the design of effective behaviour change programmes for adults with ID
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