252 research outputs found
On-chip III-V monolithic integration of heralded single photon sources and beamsplitters
We demonstrate a monolithic III-V photonic circuit combining a heralded
single photon source with a beamsplitter, at room temperature and telecom
wavelength. Pulsed parametric down-conversion in an AlGaAs waveguide generates
counterpropagating photons, one of which is used to herald the injection of its
twin into the beamsplitter. We use this configuration to implement an
integrated Hanbury-Brown and Twiss experiment, yielding a heralded second-order
correlation that confirms single-photon
operation. The demonstrated generation and manipulation of quantum states on a
single III-V semiconductor chip opens promising avenues towards real-world
applications in quantum information
Hypocalcémie post-thyroïdectomie
Introduction : LâhypocalcĂ©mie est la complication la plus prĂ©occupante de la thyroĂŻdectomie totale. Elle impose un traitement substitutif et un suivi Ă vie. Objectifs : Le but de cette Ă©tude est dâĂ©valuer lâincidence de lâhypocalcĂ©mie aprĂšs chirurgie et dâĂ©tudier sa corrĂ©lation avec les caractĂ©ristiques cliniques, biologiques et le type de chirurgie pratiquĂ©. MatĂ©riels et mĂ©thodes : Etude rĂ©trospective portant sur 488 cas de thyroĂŻdectomies, opĂ©rĂ©es entre 1992 et 1996. LâhypocalcĂ©mie est dĂ©finie par une calcĂ©mie infĂ©rieure Ă 80 mg/l «2 mmol/l ». Les patients, toujours dĂ©pendants dâun traitement substitutif un an aprĂšs la chirurgie, ont Ă©tĂ© considĂ©rĂ©s comme ayant une hypocalcĂ©mie dĂ©finitive. RĂ©sultats : Dans notre Ă©tude, 368 patients ont eu une thyroĂŻdectomie totale et 120 ont eu une thyroĂŻdectomie subtotale. Le goitre multinodulaire Ă©tait la pathologie la plus frĂ©quente, notĂ© dans 359 cas, suivie des cancers thyroĂŻdiens notĂ© dans 83 cas. LâhypocalcĂ©mie postopĂ©ratoire a Ă©tĂ© retrouvĂ©e chez 54 patients (11,06%) dont 25 Ă©taient asymptomatique. Cette hypocalcĂ©mie sâest rĂ©vĂ©lĂ©e dĂ©finitive chez 14 dâentre eux (2,8%). Nous nâavons pas trouvĂ© de corrĂ©lation statistiquement significative entre lâhypoparathyroĂŻdie dĂ©finitive et les caractĂ©ristiques cliniques biologiques et le type de chirurgie.Conclusion : Dans la plupart des cas, lâhypocalcĂ©mie est liĂ©e Ă un hypoparathyroĂŻdisme transitoire, secondaire au traumatisme ou Ă la dĂ©vascularisation des parathyroĂŻdes. LâhypoparathyroĂŻdie dĂ©finitive est rare, elle est toujours secondaire Ă une lĂ©sion irrĂ©versible des parathyroĂŻdes. Les caractĂ©ristiques cliniques initiales des patients et les examens biologiques prĂ©coces ne permettent pas de prĂ©dire lâĂ©volution.Mots-clĂ©s : ThyroĂŻde, chirurgie, hypocalcĂ©mie, parathyroĂŻde
Recidive tardive d'un sarcome a cellule claire
Introduction : The clear cell sarcoma (melanoma of soft tissue) is a rare tumor of young adults. Hi occur most commonly in the extremities. We report the case of a man of 70 years, with previous history of a malignant melanoma of the cervical trachea treated by radiotherapy, who present 18 years after Tracheo-esophageal tumor. The tumor was totally removed.Final pathologic diagnosis is a recurrence of his sarcoma cell clear. Three years later, the patient has no signs of recurrence. The aim of this work is to study the clinical features, the prognosis of these cancers and the modality of her treatments.Keywords: the clear cell sarcoma, melanoma of soft tissue, radiotherapy, surgery
Recurrent cardiac events in patients with idiopathic ventricular fibrillation, excluding patients with the Brugada syndrome
BACKGROUND: The recurrence of cardiac events in patients with idiopathic ventricular fibrillation (VF) excluding patients with the Brugada syndrome is unclear since this entity remains present in previous studies. METHODS: Since 1992, 18 patients (72% male) with idiopathic VF out of 455 ICD implants were treated with an implantable cardioverter defibrillator (ICD). The mean age at first ICD implantation was 42 ± 14 years. Brugada syndrome, as well as other primary electrical diseases (e.g. long QT), were systematically excluded in all patients by the absence of the typical electrocardiogram (ST elevation in the right precordial leads) at rest and/or after pharmacological tests (ajmaline, flecainide, or procainamide). Recurrence of cardiac events was prospectively assessed. RESULTS: During a mean follow-up period of 41 ± 27 months, VF recurrence with appropriate shock occurred in 7 patients (39%) covering a total of 27 shocks. The median time to first appropriate shock was 12 ± 9 months. There were no deaths. In the electrophysiological study, 39% of patients were inducible, but inducibility failed to predict subsequent arrhythmic events. Forty-four percent of patients suffered 21 inappropriate shocks, which were caused by sinus tachycardia, atrial arrhythmias or lead malfunction. CONCLUSION: Idiopathic ventricular fibrillation patients have a high recurrence rate of potentially fatal ventricular arrhythmias, excluding patients with the Brugada syndrome or other known causes. ICD prevents sudden cardiac death but inappropriate shocks remained a major issue in this young and active population
Comparative methods for PET image segmentation in pharyngolaryngeal squamous cell carcinoma
Several methods have been proposed for the segmentation of ÂčâžF-FDG uptake in PET. In this study, we assessed the performance of four categories of ÂčâžF-FDG PET image segmentation techniques in pharyngolaryngeal squamous cell carcinoma using clinical studies where the surgical specimen served as the benchmark
Rationale, design and population baseline characteristics of the PERFORM Vascular Project: an ancillary study of the Prevention of cerebrovascular and cardiovascular Events of ischemic origin with teRutroban in patients with a history oF ischemic strOke or tRansient ischeMic attack (PERFORM) trial
<p><b>Purpose</b></p>
<p>PERFORM is exploring the efficacy of terutroban
versus aspirin for secondary prevention in patients with a
history of ischemic stroke or transient ischemic attacks
(TIAs). The PERFORM Vascular Project will evaluate the
effect of terutroban on progression of atherosclerosis, as
assessed by change in carotid intima-media thickness
(CIMT) in a subgroup of patients.</p>
<p><b>Methods and results</b></p>
<p>The Vascular Project includes structural
(CIMT, carotid plaques) and functional (carotid
stiffness) vascular studies in all patients showing at least
one carotid plaque at entry. Expected mean follow-up is
36 months. Primary endpoint is rate of change of CIMT.
Secondary endpoints include emergent plaques and assessment
of carotid stiffness. 1,100 patients are required for
90% statistical power to detect treatment-related CIMT
difference of 0.025 mm. The first patient was randomized
in April 2006.</p>
<p><b>Conclusions</b></p>
<p>The PERFORM Vascular Project will investigate
terutrobanâs effect on vascular structure and function in
patients with a history of ischemic stroke or TIAs.</p>
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