181 research outputs found
Nearfield Acoustic Holography using sparsity and compressive sampling principles
Regularization of the inverse problem is a complex issue when using
Near-field Acoustic Holography (NAH) techniques to identify the vibrating
sources. This paper shows that, for convex homogeneous plates with arbitrary
boundary conditions, new regularization schemes can be developed, based on the
sparsity of the normal velocity of the plate in a well-designed basis, i.e. the
possibility to approximate it as a weighted sum of few elementary basis
functions. In particular, these new techniques can handle discontinuities of
the velocity field at the boundaries, which can be problematic with standard
techniques. This comes at the cost of a higher computational complexity to
solve the associated optimization problem, though it remains easily tractable
with out-of-the-box software. Furthermore, this sparsity framework allows us to
take advantage of the concept of Compressive Sampling: under some conditions on
the sampling process (here, the design of a random array, which can be
numerically and experimentally validated), it is possible to reconstruct the
sparse signals with significantly less measurements (i.e., microphones) than
classically required. After introducing the different concepts, this paper
presents numerical and experimental results of NAH with two plate geometries,
and compares the advantages and limitations of these sparsity-based techniques
over standard Tikhonov regularization.Comment: Journal of the Acoustical Society of America (2012
GESTION DES DECHETS BIOMEDICAUX A BRAZZAVILLE CAPITALE DU CONGO
The biomedical garbage (DBM) represents a major risk for the human health and constitutes a public power preoccupation. The present survey has for objective to contribute to the improvement of the management of the biomedical garbage in Congo. It is a prospective survey led in four sanitary structures of Brazzaville. It is about the hospitals of basis of Talangaï and Makélékélé, of the National Center of Blood Transfusion and the National Laboratory of Public Health. The Protocol consisted in an observation, a cross-examination through a questionnaire under - tense by a card of investigation to value the following variables: typology of the garbage, fashion of elimination of the garbage, incidents or accidents of manipulation, formation of the staff. The results are constituted of 36% of positive answer on the production of the syringes for the cutting and pungent garbage, and of 19, 61% of blood for the infectious garbage. 30, 48% of positive answers have been expressed concerning the use of the incinerator for the elimination of the garbage. 71, 13% of positive answers have been expressed concerning the existence of accidents of manipulation of the biomedical garbage. On the other hand 44, 29% of positive answers signaled the existence of the vicinal cover and that 54, 29% of the agents had received a formation on the biomedical garbage management. The biomedical garbage treatment in the studied public sanitary structures is even rudimentary and requires the setting up of a real national plan of biomedical garbage management
Etude Et Essai De Fabrication D’un Béton Géopolymère A Base Des Matériaux Locaux Qui Résiste A Une Température Elevée (Réfractaire)
Pour minimiser l'impact négatif sur l'environnement lors de la fabrication du ciment, l'une des solutions consiste à remplacer partiellement, voire totalement, le ciment standard par une nouvelle génération de liants minéraux connus sous le nom de ciments géopolymères, qui présentent des propriétés similaires aux ciments classiques. Ces liants sont obtenus par l'activation alcaline de matériaux siliceux ou aluminosilicates.Depuis la découverte des géopolymères, cette nouvelle génération de matériaux trouve des applications dans tous les domaines de l'industrie et du génie civil. En plus de leurs bonnes performances mécaniques, les bétons géopolymères résistent aux hautes températures. L'objectif de ce travail est de valoriser les matières premières locales telles que la bauxite, le kaolin et la cendre de balle de riz, et de formuler un béton géopolymère capable de supporter des températures élevées, grâce à une nouvelle formulation. Nous avons synthétisé la cendre de balle de riz et une solution de soude pour obtenir le liant géopolymère. L'ajout de bauxite calcinée ou de métakaolin au béton, avec la cendre de balle de riz, assure la réfractarité.Au cours de cette étude, de nombreux essais ont été effectués pour déterminer si les caractéristiques des bétons ainsi produits conviennent exactement à nos objectifs. Les valeurs de résistance à la compression avant traitement thermique atteignent 12,56 MPa en 7 jours pour le béton-MK et 11,02 MPa en 7 jours pour le béton-BX, tandis que, après traitement thermique à 1000°C, elles sont de 10,04 MPa pour le béton-MK et de 8,17 MPa pour le béton-BX.On peut affirmer que ces bétons offrent les meilleures performances thermiques et mécaniques, et que l'utilisation du liant géopolymère dans ces bétons contribue à réduire les émissions de dioxyde de carbone
Diagnosis, treatment and recurrence of a mandibular Langerhans cell histiocytosis: a three-year follow-up case report
Introduction: Langerhans cell histiocytosis (LCH) is an abnormal clonal proliferation of Langerhans cells secondary to immune process, mutation of oncogene or genetic predispositions. It preferentially affects bone, lung and skin. The incidence is 2–6 cases per million per year. Prognosis is variable and depends on number and location of lesions, and impact of the initial treatment. Oral lesions may be the first sign of LCH as illustrated by the present case. Observation: A 24-year-old male consulted first for severe gingival inflammation, teeth mobilities and alveolar bone loss with a suspicion of LCH. A pulmonary involvement was secondarily revealed by tomodensitometry. Histological examination, from gingival biopsy, confirmed the diagnostic of LCH, showing cells positive for the anti-CD1A antibody. The patient was managed by oral surgery and chemotherapy approaches. Alveolar bone loss significantly reduced. But 2 years and a half after the diagnosis, a recurrence was noted and managed by surgical approach. After a three-year follow-up, no recurrence was noted. Conclusion: Oral lesions can be inaugural manifestations of LCH. The dentist has an essential role in the early detection of these lesions
GESTION DES DECHETS BIOMEDICAUX A BRAZZAVILLE CAPITALE DU CONGO
The biomedical garbage (DBM) represents a major risk for the human health and constitutes a public power preoccupation. The present survey has for objective to contribute to the improvement of the management of the biomedical garbage in Congo. It is a prospective survey led in four sanitary structures of Brazzaville. It is about the hospitals of basis of Talangaï and Makélékélé, of the National Center of Blood Transfusion and the National Laboratory of Public Health. The Protocol consisted in an observation, a cross-examination through a questionnaire under - tense by a card of investigation to value the following variables: typology of the garbage, fashion of elimination of the garbage, incidents or accidents of manipulation, formation of the staff. The results are constituted of 36% of positive answer on the production of the syringes for the cutting and pungent garbage, and of 19, 61% of blood for the infectious garbage. 30, 48% of positive answers have been expressed concerning the use of the incinerator for the elimination of the garbage. 71, 13% of positive answers have been expressed concerning the existence of accidents of manipulation of the biomedical garbage. On the other hand 44, 29% of positive answers signaled the existence of the vicinal cover and that 54, 29% of the agents had received a formation on the biomedical garbage management. The biomedical garbage treatment in the studied public sanitary structures is even rudimentary and requires the setting up of a real national plan of biomedical garbage management
Safety of a fixed-dose combination of artesunate and amodiaquine for the treatment of uncomplicated Plasmodium falciparum malaria in real-life conditions of use in Côte d’Ivoire
Additional file 2. Adverse-event reporting as a function of the interval between treatment initiation and the home visit
Enhancing and neutralizing anti-coxsackievirus activities in serum samples from patients prior to development of type 1 diabetes
Abstract Studies in prospective cohorts have suggested that enterovirus infections are associated with the appearance of islet autoantibodies that precede later appearance of type 1 diabetes (T1D). It was shown that in addition to an antibody-mediated anti-coxsackievirus (CV)-B neutralizing activity of serum from patients with T1D, there was also enhancing anti-CV-B activity in vitro. In this study the patterns of enhancing and neutralizing anti-CV activities were analyzed from consecutive serum samples collected from children who were followed from birth until they developed T1D in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study and compared to those in non-diabetic control children. The titers of serum neutralizing activity were analyzed against those CVs which were detected in the stools in these children (CV-B3, CV-B5 or CV-A4) using plaque assay. The enhancing activity of these serum samples was analysed by measuring interferon-alpha (INF-α) production in cultures of peripheral blood mononuclear cells (PBMC) inoculated with a mixture of these viruses and diluted serum. A sustained anti-CV enhancing activity was observed in consecutive serum samples in patients with T1D. The pattern of responses differed between children who developed T1D and control children. In patients, the anti-CV enhancing activity was predominant or even exclusive over the neutralizing activity, whereas in controls the enhancing and neutralizing activities were more balanced or the neutralizing activity was largely predominant. In conclusion, evaluating the anti-enterovirus neutralizing and enhancing activity of serum samples can be useful to investigate further the relationship between enteroviruses and the development of T1D. This article is protected by copyright. All rights reserved.Peer reviewe
Enhancing and neutralizing anti-coxsackievirus activities in serum samples from patients prior to development of type 1 diabetes
Abstract Studies in prospective cohorts have suggested that enterovirus infections are associated with the appearance of islet autoantibodies that precede later appearance of type 1 diabetes (T1D). It was shown that in addition to an antibody-mediated anti-coxsackievirus (CV)-B neutralizing activity of serum from patients with T1D, there was also enhancing anti-CV-B activity in vitro. In this study the patterns of enhancing and neutralizing anti-CV activities were analyzed from consecutive serum samples collected from children who were followed from birth until they developed T1D in the Finnish Type 1 Diabetes Prediction and Prevention (DIPP) study and compared to those in non-diabetic control children. The titers of serum neutralizing activity were analyzed against those CVs which were detected in the stools in these children (CV-B3, CV-B5 or CV-A4) using plaque assay. The enhancing activity of these serum samples was analysed by measuring interferon-alpha (INF-α) production in cultures of peripheral blood mononuclear cells (PBMC) inoculated with a mixture of these viruses and diluted serum. A sustained anti-CV enhancing activity was observed in consecutive serum samples in patients with T1D. The pattern of responses differed between children who developed T1D and control children. In patients, the anti-CV enhancing activity was predominant or even exclusive over the neutralizing activity, whereas in controls the enhancing and neutralizing activities were more balanced or the neutralizing activity was largely predominant. In conclusion, evaluating the anti-enterovirus neutralizing and enhancing activity of serum samples can be useful to investigate further the relationship between enteroviruses and the development of T1D. This article is protected by copyright. All rights reserved.Peer reviewe
Chronic pain is a risk factor for incident Alzheimer’s disease: a nationwide propensity-matched cohort using administrative data
IntroductionChronic pain (CP) is one of the most disabling conditions in the elderly and seems to be a risk factor for the development of Alzheimer’s disease and related dementias (ADRD). Only one study, using national administrative health databases, assessed and demonstrated that chronic pain (all types of pain) was a risk factor for dementia, but without assessing the impact of pain medications.MethodTo assess the impact of all types of chronic pain and the long-term use of pain medications on the person-years incidence of ADRD, a retrospective nationwide healthcare administrative data study was performed using the national inter-regime health insurance information system (SNIIRAM) to the French national health data system (SNDS). Incident people >50 years old with chronic pain, defined by at least 6-months duration analgesics treatment or by a diagnosis/long-term illness of chronic pain between 2006 and 2010, were included. Chronic pain individuals were matched with non-CP individuals by a propensity score. Individuals were followed up from 9 to 13 years to identify occurrences of ADRD from 2006.ResultsAmong 64,496 French individuals, the incidence of ADRD was higher in the chronic pain population than control (1.13% vs. 0.95%, p <0.001). Chronic pain increases the risk of ADRD (HR = 1.23) and the incidence of ADRD was higher for women and increased significantly with age.DiscussionOur study highlights the importance of prevention, diagnosis, and management of chronic pain in elderly to reduce the risk of development and/or worsening of dementia
Neurotrophins are expressed in giant cell arteritis lesions and may contribute to vascular remodeling
International audienceIntroduction: Giant cell arteritis (GCA) is characterized by intimal hyperplasia leading to ischaemic manifestations that involve large vessels. Neurotrophins (NTs) and their receptors (NTRs) are protein factors for growth, differentiation and survival of neurons. They are also involved in the migration of vascular smooth muscle cells (VSMCs). Our aim was to investigate whether NTs and NTRs are involved in vascular remodelling of GCA.Methods: We included consecutive patients who underwent a temporal artery biopsy for suspected GCA. We developed an enzymatic digestion method to obtain VSMCs from smooth muscle cells in GCA patients and controls. Neurotrophin protein and gene expression and functional assays were studied from these VSMCs. Neurotrophin expression was also analysed by immunohistochemistry in GCA patients and controls.Results: Whereas temporal arteries of both GCA patients (n = 22) and controls (n = 21) expressed nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B (TrkB) and sortilin, immunostaining was more intense in GCA patients, especially in the media and intima, while neurotrophin-3 (NT-3) and P75 receptor (P75NTR) were only detected in TA from GCA patients. Expression of TrkB, a BDNF receptor, was higher in GCA patients with ischaemic complications. Serum NGF was significantly higher in GCA patients (n = 28) vs. controls (n = 48), whereas no significant difference was found for BDNF and NT-3. NGF and BDNF enhanced GCA-derived temporal artery VSMC proliferation and BDNF facilitated migration of temporal artery VSMCs in patients with GCA compared to controls.Conclusions: Our results suggest that NTs and NTRs are involved in vascular remodelling of GCA. In GCA-derived temporal artery VSMC, NGF promoted proliferation and BDNF enhanced migration by binding to TrkB and p75NTR receptors. Further experiments are needed on a larger number of VSMC samples to confirm these results
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