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1.
J Acoust Soc Am ; 154(3): 1526-1538, 2023 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-37695297

RESUMEN

Fishes, including elasmobranchs (sharks, rays, and skates), present an astonishing diversity in inner ear morphologies; however, the functional significance of these variations and how they confer auditory capacity is yet to be resolved. The relationship between inner ear structure and hearing performance is unclear, partly because most of the morphological and biomechanical mechanisms that underlie the hearing functions are complex and poorly known. Here, we present advanced opportunities to document discontinuities in the macroevolutionary trends of a complex biological form, like the inner ear, and test hypotheses regarding what factors may be driving morphological diversity. Three-dimensional (3D) bioimaging, geometric morphometrics, and finite element analysis are methods that can be combined to interrogate the structure-to-function links in elasmobranch fish inner ears. In addition, open-source 3D morphology datasets, advances in phylogenetic comparative methods, and methods for the analysis of highly multidimensional shape data have leveraged these opportunities. Questions that can be explored with this toolkit are identified, the different methods are justified, and remaining challenges are highlighted as avenues for future work.


Asunto(s)
Oído Interno , Peces , Animales , Filogenia , Oído Interno/diagnóstico por imagen , Análisis de Elementos Finitos , Audición
2.
Phys Rev Lett ; 129(13): 137701, 2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36206432

RESUMEN

The metal-oxide-semiconductor (MOS) capacitor is one of the fundamental electrical components used in integrated circuits. While much effort is currently being made to integrate new dielectric or ferroelectric materials, capacitors of silicon dioxide on silicon remain the most prevalent. It is perhaps surprising therefore that the electric field within such a capacitor has never been measured, or mapped out, at the nanoscale. Here we present results from operando electron holography experiments showing the electric potential across a working MOS nanocapacitor with unprecedented sensitivity and reveal unexpected charging of the dielectric material bordering the electrodes.

3.
Osteoarthr Cartil Open ; 2(1): 100029, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36474556

RESUMEN

Objective: The juvenile equine medial femoral condyle (MFC) is frequently affected with radiographic changes (sclerosis and subchondral lucencies) that arise at a similar site to juvenile osteochondritis dissecans (JOCD) in children. There is little information on maturation of the MFC. To describe the normal development of the equine MFC osteochondral unit from birth to 2 years. Methods: Micro CT, histology and immunohistochemistry were performed on healthy equine MFCs (n = 29) at sites where lesions occur. Parameters assessed included: cartilage thickness; the epiphyseal growth plate cartilage organization; the osteochondral junction and progression of endochondral ossification. Results: From 0 to 6 months, chondrocytes near the articular surface are small and flat and have a characteristic hypertrophic appearance near the osteochondral junction but are not arranged in columns like physeal growth plates. The osteochondral junction is also crossed by cartilage canals containing vessels giving a porous appearance on 3D µCT images. At 7 months of age, a subchondral bone plate compact structure emerged histologically coincident with the end of endochondral ossification (absence of type X collagen immunostain and chondrocyte hypertrophy). Conclusion: New information is provided on MFC osteochondral unit maturation that will improve our understanding of the development of juvenile equine orthopaedic disease. Equine MFC endochondral ossification is complete at 6 months of age. The immature osteochondral junction may be structurally fragile because of its microarchitecture and susceptible to focal traumatic events that induce developmental lesions.

4.
Osteoporos Int ; 30(3): 555-563, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30519756

RESUMEN

We performed a study to identify potential causes and risk factors of vertebral fracture cascade. Vertebral fracture cascade is a severe clinical event in patients with bone fragility. Only half of patients have an identified cause of secondary osteoporosis. INTRODUCTION: Vertebral fracture (VF) is the most common osteoporotic fracture, and a strong risk factor of subsequent VFs leading to VF cascade (VFC). We prompted a study to identify potential causes and risk factors of VFC. METHODS: VFC observations were collected retrospectively between January 2016 and April 2017. VFC was defined as an occurrence of at least three VFs within 1 year. RESULTS: We included in 10 centers a total of 113 patients with VFC (79.6% of women, median age 73, median number of VFs in the cascade, 5). We observed 40.5% and 30.9% of patients with previous major fractures and a previous VF, respectively, and 68.6% with densitometric osteoporosis; 18.9% of patients were currently receiving oral glucocorticoids and 37.1% in the past. VFC was attributed by the physician to postmenopausal osteoporosis in 54% of patients. A secondary osteoporosis associated with the VFC was diagnosed in 52 patients: glucocorticoid-induced osteoporosis (25.7%), non-malignant hemopathies (6.2%), alcoholism (4.4%), use of aromatase inhibitors (3.6%), primary hyperparathyroidism (2.7%), hypercorticism (2.7%), anorexia nervosa (2.7%), and pregnancy and lactation-associated osteoporosis (1.8%). A total of 11.8% of cases were reported following a vertebroplasty procedure. A total of 31.5% patients previously received an anti-osteoporotic treatment. In six patients, VFC occurred early after discontinuation of an anti-osteoporotic treatment, in the year after the last dose effect was depleted: five after denosumab and one after odanacatib. CONCLUSION: The results of this retrospective study showed that only half of VFC occurred in patients with a secondary cause of osteoporosis. Prospective studies are needed to further explore the determinants of this severe complication of osteoporosis.


Asunto(s)
Fracturas Osteoporóticas/etiología , Fracturas de la Columna Vertebral/etiología , Anciano , Anciano de 80 o más Años , Conservadores de la Densidad Ósea/uso terapéutico , Femenino , Francia/epidemiología , Glucocorticoides/efectos adversos , Humanos , Masculino , Persona de Mediana Edad , Osteoporosis/complicaciones , Osteoporosis/tratamiento farmacológico , Osteoporosis/epidemiología , Osteoporosis Posmenopáusica/complicaciones , Osteoporosis Posmenopáusica/tratamiento farmacológico , Osteoporosis Posmenopáusica/epidemiología , Fracturas Osteoporóticas/epidemiología , Recurrencia , Estudios Retrospectivos , Factores de Riesgo , Fracturas de la Columna Vertebral/epidemiología
5.
Nat Commun ; 9(1): 1814, 2018 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-29720590

RESUMEN

The original version of this Article contained an error in the last sentence of the first paragraph of the Introduction and incorrectly read 'A proper electron beam control is one of the main challenges towards the Graal of developing a compact alternative of X-ray free-electron lasers by coupling LWFA gigaelectron-volts per centimetre acceleration gradient with undulators in the amplification regime in equation 11, nx(n-ß) x ß: n the two times and beta the two times should be bold since they are vectorsin Eq. 12, ß should be bold as well.' The correct version is 'A proper electron beam control is one of the main challenges towards the Graal of developing a compact alternative of X-ray free-electron lasers by coupling LWFA gigaelectron-volts per centimetre acceleration gradient with undulators in the amplification regime.'This has been corrected in both the PDF and HTML versions of the Article.

6.
Nat Commun ; 9(1): 1334, 2018 04 06.
Artículo en Inglés | MEDLINE | ID: mdl-29626187

RESUMEN

With gigaelectron-volts per centimetre energy gains and femtosecond electron beams, laser wakefield acceleration (LWFA) is a promising candidate for applications, such as ultrafast electron diffraction, multistaged colliders and radiation sources (betatron, compton, undulator, free electron laser). However, for some of these applications, the beam performance, for example, energy spread, divergence and shot-to-shot fluctuations, need a drastic improvement. Here, we show that, using a dedicated transport line, we can mitigate these initial weaknesses. We demonstrate that we can manipulate the beam longitudinal and transverse phase-space of the presently available LWFA beams. Indeed, we separately correct orbit mis-steerings and minimise dispersion thanks to specially designed variable strength quadrupoles, and select the useful energy range passing through a slit in a magnetic chicane. Therefore, this matched electron beam leads to the successful observation of undulator synchrotron radiation after an 8 m transport path. These results pave the way to applications demanding in terms of beam quality.

7.
J Synchrotron Radiat ; 21(Pt 3): 502-6, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24763639

RESUMEN

In order to improve the efficiency of X-ray absorption data recording, a fast scan method, the Turboscan, has been developed on the DEIMOS beamline at Synchrotron SOLEIL, consisting of a software-synchronized continuous motion of the monochromator and undulator motors. This process suppresses the time loss when waiting for the motors to reach their target positions, as well as software dead-time, while preserving excellent beam characteristics.

9.
Int J Rehabil Res ; 23(2): 81-9, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10929660

RESUMEN

Four studies have been recently undertaken at the Centre for International Child Health on the collaboration between the stakeholders of disability policies, in Southern and Northern countries. Informed by the literature, the authors have explored the roles disabled people's organizations, non-governmental organizations, government and professionals play in the design, provision and evaluation of services for disabled people. They also highlight the different forms participation can take and their most relevant features. The main factors influencing collaboration processes are then classified in three different categories: social factors, ideology-related factors and project-related factors. They are subsequently analysed. The first group encompasses the societal framework in which collaboration may take place, while the identity of the stakeholders is reflected in the ideology-related factors. The nature of the activities undertaken by stakeholders is characterized by the third group of factors. In the conclusion it is suggested that stakeholders, and especially disabled people's counterparts, should increase their awareness of the social model of disability, adopt participatory practices and promote participation at higher levels. However, they should acknowledge that it implies more trust between partners and an alteration of their structures.


Asunto(s)
Redes Comunitarias/organización & administración , Países Desarrollados , Países en Desarrollo , Personas con Discapacidad/legislación & jurisprudencia , Sector Privado/organización & administración , Redes Comunitarias/legislación & jurisprudencia , Participación de la Comunidad/legislación & jurisprudencia , Conducta Cooperativa , Gobierno , Política de Salud , Humanos , Relaciones Interinstitucionales , Inversiones en Salud , Sector Privado/legislación & jurisprudencia
10.
Gastroenterol Clin Biol ; 23(1): 105-13, 1999 Jan.
Artículo en Francés | MEDLINE | ID: mdl-10219611

RESUMEN

AIMS: This study was performed to compare the sensitivity of ultrasonography, computerized tomography during arterial portography, delayed computerized tomography, and magnetic resonance imaging to detect focal liver lesions. Forty three patients with primary or secondary malignant liver lesions were studied prior to surgical intervention. METHODS: The results of the imaging studies were compared with intraoperative examination of the liver, intraoperative ultrasonography and pathology results (29 patients). In the non-operated (14 patients) group, we compared the number of lesions detected by each technique. RESULTS: One hundred and forty six lesions were detected. There was 84% sensitivity with computerized tomography during arterial portography, 61.3% with delayed scan, 63.3% with magnetic resonance imaging and 51% with ultrasonography in operated patients. In patients who did not undergo surgery, magnetic resonance imaging was more sensitive in detecting lesions. CONCLUSIONS: In operated and non-operated patients series, CT during arterial portography had the highest sensitivity, but magnetic resonance imaging had the most consistent overall results.


Asunto(s)
Neoplasias Hepáticas/diagnóstico por imagen , Neoplasias Hepáticas/diagnóstico , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Evaluación como Asunto , Femenino , Humanos , Neoplasias Hepáticas/cirugía , Masculino , Persona de Mediana Edad , Portografía , Sensibilidad y Especificidad , Factores de Tiempo , Ultrasonografía
11.
Schweiz Med Wochenschr ; 126(29): 1251-7, 1996 Jul 20.
Artículo en Francés | MEDLINE | ID: mdl-8765943

RESUMEN

Percutaneous drainage of abscesses and other abnormal fluid collections is a recent development of interventional radiology. The indications and results of these treatments are presently well established, as is their place relative to the standard of care, surgical drainage. This paper reviews in particular the technical aspects of percutaneous fluid collection drainage and highlights the practical experience of the authors. The following points are discussed: patient selection and preparation, advantages and shortcomings of the different imaging techniques available for drainage guidance, an outline of the different puncture methods according to difficulty of collection access, choice of drain type, clinical and imaging follow-up of the drained collection, and finally specific precautions in some common clinical situations. The pitfalls and complications of these methods are also discussed.


Asunto(s)
Absceso/terapia , Drenaje/métodos , Radiología Intervencionista/métodos , Fístula/diagnóstico por imagen , Fístula/terapia , Fluoroscopía , Humanos , Selección de Paciente , Tomografía Computarizada por Rayos X , Ultrasonografía
13.
J Thorac Imaging ; 11(1): 39-45, 1996.
Artículo en Inglés | MEDLINE | ID: mdl-8770825

RESUMEN

Dynamic computed tomography (CT) is frequently performed to assess the mediastinum in trauma patients with a suspected thoracic aortic rupture. Its usefulness lies in demonstrating a mediastinal hematoma. However, many patients still undergo conventional aortography despite a normal chest. CT, because of a perceived insensitivity of this technique for diagnosing aortic rupture. One application of helical CT is CT angiography, in which multiple thin sections are acquired through a blood vessel during the injection of iodinated contrast. Good demonstration of vascular pathology can be achieved, especially with 3-D reconstructions. This article reviews a series of four surgically proven thoracic aortic ruptures studied using helical CT, and one case proven to be false-positive by both helical CT angiography and conventional angiography. Correlation between conventional and helical CT angiography was excellent, with similar findings and the same interpretation pitfalls. Helical CT is fast and noninvasive. Combined examination of other anatomical areas can be performed in the same procedure in major trauma patients. Helical CT may potentially decrease the need for aortography in these acutely injured patients.


Asunto(s)
Aorta Torácica/lesiones , Rotura de la Aorta/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Heridas no Penetrantes/diagnóstico por imagen , Adulto , Anciano , Aorta Torácica/cirugía , Rotura de la Aorta/cirugía , Aortografía , Humanos , Masculino , Estudios Retrospectivos , Heridas no Penetrantes/cirugía
14.
Am J Respir Crit Care Med ; 150(5 Pt 1): 1355-62, 1994 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-7952564

RESUMEN

The effectiveness of intermittent administration of rifapentine (RPT), with or without isoniazid (INH), for preventive therapy of tuberculosis was evaluated in immunocompetent (normal) and nude mice. After infection with a small inoculum of Mycobacterium tuberculosis H37Rv, normal mice developed a chronic and nonfatal infection, and the bacterial population became relatively stable after an initial period of limited multiplication. On the other hand, nude mice developed an acute and fatal infection, and all untreated mice died within 5 wk, with very high colony-forming-unit (CFU) counts in their organs. Various degrees of bactericidal activity were shown in normal mice after daily treatment with rifampin (RMP) plus pyrazinamide (PZA) for 13 wk, INH daily for 26 wk, or RPT once weekly for 13 or 26 wk or once fortnightly for 26 wk. The activity of RPT was significantly enhanced when INH was added at the same dosing frequency. In nude mice the response of M. tuberculosis infection to certain regimens was less favorable than that in normal mice, suggesting that preventive therapy may be less effective in severely immunodeficient hosts even during treatment. After chemotherapy was stopped, virtually all nude mice relapsed within 12 wk regardless of the regimen administered, whereas no or very few relapses were observed in normal mice that had been treated with RMP+PZA daily for 13 wk, or RPT alone or RPT+INH once weekly for 26 wk. The latter three regimens and RPT+INH once weekly for 13 wk may be applied for fixed-duration preventive therapy in human immunodeficiency virus (HIV)-negative subjects.(ABSTRACT TRUNCATED AT 250 WORDS)


Asunto(s)
Antituberculosos/uso terapéutico , Rifampin/análogos & derivados , Tuberculosis/inmunología , Tuberculosis/prevención & control , Animales , Ensayo de Unidades Formadoras de Colonias , Quimioterapia Combinada , Femenino , Inmunidad , Isoniazida/administración & dosificación , Ratones , Ratones Desnudos , Pirazinamida/administración & dosificación , Rifampin/administración & dosificación , Rifampin/uso terapéutico , Tuberculosis/patología
15.
J Hepatol ; 19(3): 383-4, 1993 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-8151098

RESUMEN

In this paper, three cases of grand mal seizures are reported as a complication of pefloxacin at usual doses (400 mg twice a day) in patients with cirrhosis. Grand mal seizures occurred from 12 h to 8 days after the onset of pefloxacin treatment. In 1 case, seizures recurred after inadvertent rechallenge with the drug. Elevated pefloxacin serum levels were demonstrated in 2 cases. Brain computed tomography in all 3 cases and cerebrospinal fluid examination showed normal results. No etiology other than pefloxacin overdose was found. After pefloxacin withdrawal, no recurrence of seizures were observed. Therefore, when pefloxacin treatment is indicated for cirrhotic patients, a reduced dosage and/or careful monitoring of pefloxacin serum levels should be recommended.


Asunto(s)
Epilepsia Tónico-Clónica/inducido químicamente , Cirrosis Hepática/tratamiento farmacológico , Pefloxacina/efectos adversos , Niño , Femenino , Humanos , Cirrosis Hepática/complicaciones , Persona de Mediana Edad , Pefloxacina/administración & dosificación
16.
Schweiz Med Wochenschr ; 123(43): 2015-22, 1993 Oct 30.
Artículo en Francés | MEDLINE | ID: mdl-8272777

RESUMEN

Aortic dissection requires a prompt diagnosis and must be treated without delay in order to reduce the mortality rate. Whereas aortic dissection involving the ascending aorta (type A) requires immediate surgery, aortic dissection involving the descending aorta (type B) will usually be treated conservatively. This review article reevaluates the respective efficiency of conventional and modern radiological means offered in a well equipped university hospital.


Asunto(s)
Aneurisma de la Aorta Abdominal/diagnóstico , Aneurisma de la Aorta Torácica/diagnóstico , Disección Aórtica/diagnóstico , Disección Aórtica/cirugía , Aneurisma de la Aorta Abdominal/cirugía , Aneurisma de la Aorta Torácica/cirugía , Aortografía , Humanos , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X
17.
Pediatr Radiol ; 23(3): 198-9, 1993.
Artículo en Inglés | MEDLINE | ID: mdl-8332408

RESUMEN

We report the case of a boy with Budd-Chiari syndrome. At 3 years of age a meso-atrial shunt was inserted for thrombosis of the hepatic veins with associated inferior vena cava occlusion by an enlarged caudate lobe. Seven uneventful years later, the patient was reassessed because of concern about insufficient length of the synthetic shunt. Ultrasound with color Doppler imaging (CDI) and magnetic resonance imaging (MRI) with magnetic resonance angiography (MRA) clearly depicted a patent graft, without kinking, stenosis or other sign of graft dysfunction. Conventional selective angiography confirmed the patency of the shunt. MRI with MRA and CDI are less invasive and less expensive than conventional angiography and might replace this technique for assessment of meso-atrial shunt patency.


Asunto(s)
Síndrome de Budd-Chiari/cirugía , Derivación Portosistémica Quirúrgica , Angiografía de Substracción Digital , Niño , Preescolar , Oclusión de Injerto Vascular/diagnóstico , Humanos , Imagen por Resonancia Magnética , Masculino , Arteria Mesentérica Superior/diagnóstico por imagen , Ultrasonido , Grado de Desobstrucción Vascular , Vena Cava Inferior/diagnóstico por imagen
18.
Neuroradiology ; 33(5): 403-6, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1749469

RESUMEN

Computed tomography (CT) is the gold standard for exact delineation of inflammatory sinus disease, especially before endoscopic surgical treatment, and in cases of postoperative recurrences. In routine CT studies, the radiation dose to the patient is not negligible. Therefore, the authors evaluated prospectively the CT scans of 44 patients with inflammatory disease of the paranasal sinuses, to define the imaging ability of low-dose CT (i.e. 60 mA-3 s, 30 mA-3 s, and 30 mA-2 s), comparatively with the standard mAs settings (130 mA-3 s). In all cases, the exact extent of the disease was correctly assessed on each of the low-dose settings, with no false negative study. The increasing graininess of low mAs sections did not induce errors of interpretation, despite a less pleasant appearance to the eyes. In cases of extensive sinus disease, the thickness and integrity of the ethmoid septa were sometimes more difficult to evaluate on low-dose CT sections. The authors recommend the use of low mAs settings in the evaluation of inflammatory disease of the sinuses, complemented, if necessary, in cases of extensive abnormalities, by one or two sections obtained with standard mAs settings, focused on questionably abnormal bone septa.


Asunto(s)
Senos Paranasales/diagnóstico por imagen , Sinusitis/diagnóstico por imagen , Tomografía Computarizada por Rayos X/métodos , Adulto , Estudios de Evaluación como Asunto , Femenino , Humanos , Masculino , Estudios Prospectivos , Dosis de Radiación , Protección Radiológica , Sinusitis/epidemiología
19.
Pediatr Radiol ; 21(7): 515-7, 1991.
Artículo en Inglés | MEDLINE | ID: mdl-1771119

RESUMEN

A 10-day-old girl who initially presented with fever developed over five days a complete paresis of both upper arms and swallowing difficulty. After emergency drainage of a retropharyngeal abscess, cervical US demonstrated a cervical anterior epidural mass compressing the cord. MRI confirmed the diagnosis of spinal epidural abscess secondary to C4-C5 spondylodiscitis. Surgical removal of the abscess was followed by complete disappearance of the neurologic symptoms after six months of follow-up. This is the first case of spinal epidural abscess in a newborn to be diagnosed by US and MRI preoperatively. The advantages of these non-invasive imaging modalities are discussed, and compared to myelography.


Asunto(s)
Absceso/diagnóstico , Imagen por Resonancia Magnética , Enfermedades de la Médula Espinal/diagnóstico , Infecciones Estafilocócicas/diagnóstico , Absceso/diagnóstico por imagen , Vértebras Cervicales/diagnóstico por imagen , Discitis/complicaciones , Femenino , Humanos , Recién Nacido , Radiografía , Enfermedades de la Médula Espinal/diagnóstico por imagen , Infecciones Estafilocócicas/diagnóstico por imagen , Ultrasonografía
20.
J Radiol ; 71(8-9): 489-94, 1990.
Artículo en Francés | MEDLINE | ID: mdl-2266521

RESUMEN

Two hundred ninety five consecutive brain CT examinations of asymptomatic adults were studied prospectively for detection of nontumoral paranasal sinus abnormalities. CT alterations were found in 104 cases (35.3%), localized to the ethmoid cells in 83 cases, the maxillary sinuses in 56 cases, the sphenoid sinuses in 19 cases, and the frontal sinuses in 18 cases. The relationships between ethmoid cells disease and alterations of the large paranasal cavities are analysed, and the association with previous sinusitis or rhinitis is evaluated. Frontal sinus disease is associated in more than two-thirds of the cases with pathologic meatic and/or unciform ethmoid cells, but such an association could not be demonstrated for the other cavities.


Asunto(s)
Encéfalo/diagnóstico por imagen , Enfermedades de los Senos Paranasales/epidemiología , Adolescente , Adulto , Anciano , Sinusitis del Etmoides/diagnóstico por imagen , Sinusitis del Etmoides/epidemiología , Femenino , Sinusitis Frontal/diagnóstico por imagen , Sinusitis Frontal/epidemiología , Humanos , Masculino , Sinusitis Maxilar/diagnóstico por imagen , Sinusitis Maxilar/epidemiología , Persona de Mediana Edad , Enfermedades de los Senos Paranasales/diagnóstico por imagen , Estudios Prospectivos , Estudios Retrospectivos , Sinusitis del Esfenoides/diagnóstico por imagen , Sinusitis del Esfenoides/epidemiología , Tomografía Computarizada por Rayos X
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