693 research outputs found
Solar Reector Design
The design of solar panels is investigated. Different aspects of this problem are presented. A formula averaging the solar energy received on a given location is derived rst. The energy received by the collecting solar panel is then calculated using a specially designed algorithm. The geometry of the device collecting the energy may then be optimised using different algorithms. The results show that for a given depth, devices of smaller width are more energy efficient than those of wider dimensions. This leads to a more economically efficient design
Cutaneous sarcoidosis simulating porokeratosis of Mibelli
We report a skin localization of systemic sarcoidosis, which presented with lesions that resemble porokeratosis of Mibelli. Skin biopsy showed noncaseating sarcoidal granuloma. Whereas cutaneous sarcoidosis is present in up to one-third of cases and may present with a wide variety of lesions, our presentation is uncommon. Partial remission was obtained with hydroxychloroquine and prednison
Collaborative team training in virtual reality is superior to individual learning for performing complex open surgery: a randomised controlled trial
Objective: To assess if multiplayer virtual reality (VR) training was superior to single player training for acquisition of both technical and non-technical skills in learning complex surgery. Summary Background Data: Superior team-work in the operating room (OR) is associated with improved technical performance and clinical outcomes. VR can successfully train OR staff individually, however VR team training has yet to be investigated. Method: Forty participants were randomised to individual or team VR training. Individually-trained participants practiced alongside virtual avatar counterparts, whilst teams trained live in pairs. Both groups underwent five VR training sessions over 6-weeks. Subsequently, they underwent a real-life assessment in which they performed Anterior Approach Total Hip Arthroplasty (AA-THA) surgery on a high-fidelity model with real equipment in a simulated OR. Teams performed together and individually-trained participants were randomly paired up. Videos were marked by two blinded assessors recording the NOTSS, NOTECHS II and SPLINTS scores. Secondary outcomes were procedure time and number of technical errors. Results: Teams outperformed individually-trained participants for non-technical skills in the real-world assessment (NOTSS 13.1±1.5 vs 10.6±1.6, P=0.002, NOTECHS-II score 51.7±5.5 vs 42.3±5.6, P=0.001 and SPLINTS 10±1.2 vs 7.9±1.6, P=0.004). They completed the assessment 28.1% faster (27.2 minutes±5.5 vs 41.8 ±8.9, P<0.001), and made fewer than half the number of technical errors (10.4±6.1 vs 22.6±5.4, P<0.001). Conclusions: Multiplayer training leads to faster surgery with fewer technical errors and the development of superior non-technical skills
Traitement chirurgical des metastases sternales du cancer differencie de la thyroide
Le carcinome folliculaire est la deuxième tumeur maligne la plus fréquente de la thyroïde et l’invasion hématologique est le moyen de propagation le plus courant de ses métastases. Les localisations secondaires à ces cancers siègent principalement au niveau des poumons, suivi par les localisations osseuses, cérébrales et hépatiques. L’irathérapie est classiquement le traitement de choix des métastases des cancers différenciés de la thyroïde ; toutefois les métastases osseuses sont réputées résistantes à cette forme de traitement. La résection chirurgicale des métastases à distance des cancers différenciés de la thyroïde offre de meilleures chances d’obtenir de longues survies et d’espérer une meilleure qualité de vie. Nous rapportons deux cas de métastases sternales d’un carcinome différencié de la thyroïde qui ont été bien contrôlées par un traitement chirurgical impliquant une exérèse partielle du sternum avec reconstruction par suture directe dans un cas et utilisant un lambeau du grand pectoral dans le deuxième cas. Avec un suivi moyen de 28 mois, aucune récidive locale ou à distance n’a été détectée. A travers une revue de la littérature évaluant les caractéristiques de métastases sternales des carcinomes différenciés la thyroïde traitées chirurgicalement, on a démontré qu’une résection radicale de ces métastases peut être réalisée chez des patients ayant un faible pronostic initial afin d’obtenir une rémission et d’optimiser le traitement par l’iode radioactif.Mots clés : Thyroïde, traitement, cancer, métastases sternales, sternectomies
Serum p53 antibodies: predictors of survival in small-cell lung cancer?
Serum p53 antibodies have been shown to be a poor prognostic marker in resected non-small-cell lung cancer (NSCLC), but studies in small-cell lung cancer (SCLC) have been contradictory. We have studied the incidence of p53 antibodies in a large SCLC cohort treated at one oncology centre and correlated the results with survival. 231 patients (63% male, median age 65), diagnosed and treated for SCLC between 1987 and 1994 at The Royal Marsden Hospital NHS Trust, had sera stored pretreatment. All samples were tested for p53 antibodies (p53-Ab) using a standardized ELISA technique with a selection of strongly ELISA positive, weakly ELISA positive and negative samples being confirmed with immunoprecipitation. 54 patients were positive for p53-Ab (23%). The presence of a high titre of p53-Ab (titre ratio >5) appears to be associated with a survival advantage with a relative risk of death of 1.71 (95% CI: 1.14–2.58) in those without the antibody (P = 0.02). This study, the largest homogenous group so far looking at p53-Ab in SCLC, suggests that p53 antibody detection may have a role in predicting outcome in this type of cancer. © 2000 Cancer Research Campaign http://www.bjcancer.co
Sea level changes in the Mediterranean: tectonic implications
The interpretation of sea level variations along the coasts of the Mediterranean region must be accompanied by the evaluation of vertical land movements associated with seismic and volcanic sources. This can be tentatively carried out through seismic strain analysis based on data pertaining the last 2 millennia as well as from the study of maritime archaeological structures.PublishedHersonissos, Crete island, Greece3.3. Geodinamica e struttura dell'interno della Terraope
Sea level changes and vertical land movements in the Mediterranean from historical and geophysical data and modelling
The Mediterranean basin is a natural laboratory for the reconstruction of the sea level variations since paleo-historical times. During the Holocene, sea level variations in this region have been mainly determined by the response of the geoid and of the solid Earth to the melting of remote ice aggregates, which has produced spatially variable signals mostly governed by the effect of ocean loading. An analysis of past and recent sea level variations is possible from various indicators, which provide data on relative sea level and crustal vertical movements on different time scales.PublishedBurlington house, London3.3. Geodinamica e struttura dell'interno della Terraope
A new approach to the modelling of local defects in crystals: the reduced Hartree-Fock case
This article is concerned with the derivation and the mathematical study of a
new mean-field model for the description of interacting electrons in crystals
with local defects. We work with a reduced Hartree-Fock model, obtained from
the usual Hartree-Fock model by neglecting the exchange term. First, we recall
the definition of the self-consistent Fermi sea of the perfect crystal, which
is obtained as a minimizer of some periodic problem, as was shown by Catto, Le
Bris and Lions. We also prove some of its properties which were not mentioned
before. Then, we define and study in details a nonlinear model for the
electrons of the crystal in the presence of a defect. We use formal analogies
between the Fermi sea of a perturbed crystal and the Dirac sea in Quantum
Electrodynamics in the presence of an external electrostatic field. The latter
was recently studied by Hainzl, Lewin, S\'er\'e and Solovej, based on ideas
from Chaix and Iracane. This enables us to define the ground state of the
self-consistent Fermi sea in the presence of a defect. We end the paper by
proving that our model is in fact the thermodynamic limit of the so-called
supercell model, widely used in numerical simulations.Comment: Final version, to appear in Comm. Math. Phy
Challenges to the development of antigen-specific breast cancer vaccines
Continued progress in the development of antigen-specific breast cancer vaccines depends on the identification of appropriate target antigens, the establishment of effective immunization strategies, and the ability to circumvent immune escape mechanisms. Methods such as T cell epitope cloning and serological expression cloning (SEREX) have led to the identification of a number target antigens expressed in breast cancer. Improved immunization strategies, such as using dendritic cells to present tumor-associated antigens to T lymphocytes, have been shown to induce antigen-specific T cell responses in vivo and, in some cases, objective clinical responses. An outcome of successful tumor immunity is the evolution of antigen-loss tumor variants. The development of a polyvalent breast cancer vaccine, directed against a panel of tumor-associated antigens, may counteract this form of immune escape
LESIONS PAPULO-PUSTULEUSES PRURIGINEUSES DU VISAGE ASSOCIEES A UNE CONJONCTIVITE CHRONIQUE
We report a case of face localization of demodecidosis wich presented as papulopustular lesion associated to ocular manifestations (chronic blepharitis, chelazian). Demodecidose is induced by Demodex folliculorum. This parasit can induced various clinical pictures as folliculitis; blepharitis, rosaciformes dermatosis. The diagnosis was made by the presence of the parasit on direct examination of skin prelevement. Cyclines seems to be an interesting alternative to acaricides in the treatment of demodecidosis.Notre patient présente une démodécidose du visage sous forme de lésions papulo-pustuleuses associées à une atteinte oculaire à type de blépharite chronique et de chalazion de l’oeil gauche. La démodécidose est due à Demodex folliculorum. Ce parasite peut être associé à différents tableaux cliniques dont les folliculites, les dermites rosacéiformes ou les blépharites. Le diagnostic est conformé par la présence de parasite à l’examen direct. L’emploi de cyclines semble être une alternative intéressante aux acaricides de contact dans la démodécidose
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