QKD in Standard Optical Telecommunications Networks

To perform Quantum Key Distribution, the mastering of the extremely weak signals carried by the quantum channel is required. Transporting these signals without disturbance is customarily done by isolating the quantum channel from any noise sources using a dedicated physical channel. However, to really profit from this technology, a full integration with conventional network technologies would be highly desirable. Trying to use single photon signals with others that carry an average power many orders of magnitude bigger while sharing as much infrastructure with a conventional network as possible brings obvious problems. The purpose of the present paper is to report our efforts in researching the limits of the integration of QKD in modern optical networks scenarios. We have built a full metropolitan area network testbed comprising a backbone and an access network. The emphasis is put in using as much as possible the same industrial grade technology that is actually used in already installed networks, in order to understand the throughput, limits and cost of deploying QKD in a real network

Tilted Photoalignment of a Nematic Liquid Crystal Induced by a Magnetic Field

Nematic liquid crystal cells with polyvinyl cinnamate coated substrates were subjected to ultraviolet light. When this was done in the presence of an oblique magnetic field the photoalignment was found to be temporally and thermally robust, with a large pretilt angle and weak polar anchoring. Moreover, two easy axes with equal and opposite pretilt angle were obtained, such that a magnetic field could switch the director from one easy axis to the other. (C) 1998 American Institute of Physics.</p

Determinants of Early and Late In-Hospital Mortality After Acute Myocardial Infarction: A Subanalysis of the OBTAIN Registry

Predictors of in-hospital mortality after myocardial infarction (MI) have been reported dichotomously: survival vs death. Predictors of time from admission to death have not been reported. A total of 7335 patients were enrolled in a prospective multicentre registry of acute MI. In-hospital mortality was classified by time from admission as acute (≤ 2 days), subacute (3 to 7 days), late (8 to 14 days), and very late (≥ 15 days) to identify factors associated with time to death in patients who died before discharge. Patient and MI characteristics, in-hospital interventions, and electrocardiographic findings were screened for differences in time to in-hospital death. In-hospital death affected 351 patients (4.8%). Mean age was 72.0 ± 12.4 years, and 40.5% were female patients. Median survival was 5 days (interquartile range: 2-12), and 41% of in-hospital deaths occurred after 1 week. Cardiac biomarkers and ejection fraction were not related to time to in-hospital death. Previous MI, systolic blood pressure, pharmacologic therapy, and interventional treatments were different among the 4 groups. The factors associated with late in-hospital death were coronary artery bypass graft surgery (CABG), new-onset atrial fibrillation or flutter, heart failure or pulmonary edema, bleeding, and lung disease. Acute and subacute in-hospital death was associated with ST-elevation MI, lower systolic blood pressure, and cardiac arrest on admission. CABG was performed in 12% of post-MI patients who died in hospital. Clinical risk factors for in-hospital mortality evolve over time immediately after acute MI. Understanding the time-dependent risk factors may allow for the development of new approaches to curtail the “later” in-hospital mortality. Les facteurs prédictifs de mortalité hospitalière après un infarctus du myocarde (IM) sont présentés en fonction de la dichotomie survie/décès. Les facteurs prédictifs du temps écoulé entre l’admission à l’hôpital et le décès des patients sont omis. Au total, 7 335 patients ont été inscrits dans un re-gistre prospectif multicentrique de cas d’IM aigu. La mortalité hospitalière, ventilée en fonction du temps écoulé depuis l’admission à l’hôpital, pouvait être aiguë (2 jours ou moins), subaiguë (3 à 7 jours), tardive (8 à 14 jours) ou très tardive (15 jours ou plus). Cette ventilation visait à cerner les facteurs associés au temps écoulé avant les décès hospitaliers. Les caractéristiques individuelles et celles de l’IM, les interventions intrahospitalières et les résultats électrocardiographiques ont fait l’objet d’un examen visant à déceler des différences au chapitre du temps écoulé avant les décès hospitaliers. Au total, 351 patients (4,8 %) sont décédés à l’hôpital. L’âge moyen était de 72,0 ± 12,4 ans et 40,5 % des patients étaient des femmes. La survie médiane était de cinq jours (intervalle interquartile : 2-12) et 41 % des décès hospitaliers sont survenus après une semaine. Les biomarqueurs cardiaques et la fraction d’éjection n’étaient pas liés au temps écoulé avant les décès hospitaliers. Des différences exis-taient entre les quatre groupes en ce qui concerne les antécédents d’IM, la pression artérielle systolique, la pharmacothérapie et les traitements interventionnels. Les facteurs associés à la mortalité hospitalière tardive comprenaient le pontage aortocoronarien (PAC), la fibrillation auriculaire ou le flutter auriculaire d’apparition récente, l’insuffisance cardiaque ou l’œdème pulmonaire, le saignement et les pneumopathies. La mortalité hospitalière aiguë et subaiguë était associée à l’IM avec élévation du segment ST, à l’abaissement de la pression artérielle systolique et à l’arrêt cardiaque à l’admission. Un PAC avait été pratiqué après l’IM chez 12 % des patients décédés à l’hôpital. Les facteurs de risque cliniques de mortalité hospitalière évoluent au fil du temps immédiatement après un IM aigu. La connaissance des facteurs de risque chronodépendants peut permettre l’élaboration de nouvelles approches visant à limiter la mortalité hospitalière « tardive ». [Display omitted

Clinical profile and prognostic value of anemia at the time of admission and discharge among patients hospitalized for heart failure with reduced ejection fraction: findings from the EVEREST trial

Anemia has been associated with worse outcomes in patients with chronic heart failure (HF). We aimed to characterize the clinical profile and postdischarge outcomes of hospitalized HF patients with anemia at admission or discharge