This work presents a detailed modeling-based analysis of integrated micro-ring resonators used for absorption spectroscopy. Generally, sensors based on micro-ring resonators detect changes in the ...real part of the sensing medium refractive index, at critical coupling. In absorption spectroscopy, however, micro-ring resonators are used to measure changes in the imaginary part of the index and are most sensitive away from critical coupling, with separate maxima in the under- and over-coupled regimes. In this work, we present a detailed analysis of the under-coupled regime, explaining the relationships between sensitivity, mode confinement, and losses. The analysis is based on reverse-symmetry waveguides to increase the proportion of mode power in the sensing medium and incorporates a realistic model of propagation losses based on experimental measurements of sidewall roughness. The analysis demonstrates that the resonant nature of the sensor is most effective at small radii compared to a non-resonant structure of equal size and shows a behavior of diminishing returns at larger device sizes regarding sensitivity and elevated proportions of mode power in the evanescent field.
Abstract Introduction Trochlear dysplasia is one of the main elements of patellofemoral instability. Although correction by trochleoplasty seems logical, the long-term outcome of this procedure is ...unknown and the progression to osteoarthritis has not been clarified. Thus, we performed a retrospective study of a series of sulcus deepening trochleoplasties with a 15-year follow-up whose goal was to (1) evaluate the long-term clinical outcome and radiological rate of osteoarthritis, and (2) define the results in relation to the type of instability and the grade of dysplasia. Hypothesis Sulcus deepening trochleoplasty is an effective procedure to stabilize the patellofemoral joint that does not increase the risk of osteoarthritis. Patients and methods This retrospective study analyzed 34 sulcus deepening trochleoplasties based on clinical scores (IKS, Lille, Kujala and Oxford scores) and radiological results (stage of osteoarthritis according to the Iwano score) after a mean follow-up of 15 years (12–19 years). An Insall procedure was systematically associated with an anterior tibial tubercle transfer in 17 cases (7 prior tibial transfers). Results No recurrent objective instability was observed. Seven knees had additional surgery after a mean follow-up of 7 years (2–16): 7 underwent conversion to total knee arthroplasty because of progression of osteoarthritis and one knee had tibial tubercle transfer for pain and episodes of the knee giving way. The mean Lille, Kujala and IKS scores increased from 53.3 (30–92), 55 (13–75) and 127 (54–184) to 61.5 (25–93), 76 (51–94) and 152.4 (66–200) respectively between preoperative and follow-up assessment ( P < 0.05) (revisions included). Functional outcome was significantly better for dysplasia with supratrochlear spurs (IKS score 168 127–200 versus 153 98–198 and Kujula score 81.5 51–98 versus 76 51–94 P < 0.05). Patients were satisfied in 65% of the cases and the total mean Oxford score was 24.1/60 (12–45 points). Occasional pain was present in 53% of the cases. The trochlear prominence decreased from 4.9 mm (3–9 mm) to −1.2 mm (−7–4 mm). Ten cases of preoperative patellofemoral osteoarthritis were identified, but none with > Iwano 2, while osteoarthritis was present in 33/34 cases at the final follow-up with 20 cases > Iwano 2 (65%). Discussion Sulcus deepening trochleoplasty corrects patellofemoral stability even in patients with severe dysplasia and the long-term functional outcome is better in this group. It does not prevent patellofemoral osteoarthritis. It should be limited to severe dysplasia with supratrochlear spurs and associated with procedures to realign the extensor apparatus. Level of evidence IV, retrospective cohort study.
Summary Introduction Results of unicompartmental knee arthroplasty (UKA) revision are known but the severity of bone loss and the need for reconstruction are not detailed for different tibial ...implants. Hypothesis Metal-backing UKA revision exposes the patient to more severe tibial bone loss and requires more substantial reconstruction procedures than cemented polyethylene UKA revision. Materials and methods This retrospective series of 23 revisions of UKA to total knee arthroplasty (TKA) compared 11 all-polyethylene UKAs with 12 metal-backing UKAs. Factors that contributed to failure were aseptic loosening ( n = 12) and osteoarthritis evolution ( n = 11). Both groups were similar regarding the demographic and clinical features. We reported bone loss and the reconstruction procedure to fill it according to the initially used tibial implant. The results were evaluated with the IKS score to a follow-up of 37 months (range, 24–67 months). Results There were more tibial segmental bone loss (10 versus 3) and more metal wedges (8/12 versus 2/11) in metal-backing UKA revision ( P < 0.05). Tibial stems were more often used in metal-backing UKA revision (12/12 versus 7/11) ( P = 0.04). The results of TKA at follow-up did not differ according to whether the revised tibial implant was all polyethylene (IKS = 155 range, 107–195) or metal-back (IKS = 155 range, 127–172). Discussion This study suggests that metal-backing UKA revision exposes the patient to more severe tibial bone loss requiring more substantial reconstruction. These results must be confirmed on a larger population, but surgeons should be alerted to this kind of revision surgery, which warrants having available a revision knee prothesis. Level of evidence Level III, case-control study.
Deux cas de luxation dorsale bipolaire simultanée des articulations interphalangiennes de l’auriculaire d’origine traumatique sont ici présentés. Dans les deux cas un traitement orthopédique par ...simple syndactylisation, après réduction par manœuvre externe, associée à une autoréeducation immédiate a été réalisé. À la revue, on ne notait aucune complication. Les mobilités articulaires à distance étaient comprises dans les limites de la normale.
Two cases of simultaneous traumatic dorsal dislocation of the interphalangeal joints of the little finger are described. In both cases the patients were managed by closed reduction and neighbour strapping followed by immediate mobilisation. At review, no complications were noted. The range of movements of all the affected joints was normal.
Two cases of simultaneous traumatic dorsal dislocation of the interphalangeal joints of the little finger are described. In both cases the patients were managed by closed reduction and neighbour ...strapping followed by immediate mobilisation. At review, no complications were noted. The range of movements of all the affected joints was normal.
P124 - Maladie de Gorham-Stout : à propos d’un cas Klein, C.; Rouanet, T.; Nectoux, E. ...
Archives de pédiatrie : organe officiel de la Société française de pédiatrie,
6/2010, Letnik:
17, Številka:
6
Journal Article
Recenzirano
La maladie de Gorham-Stout ou « ostéolyse massive idiopathique » est une maladie rare d’étiologie inconnue. Moins de deux cents cas sont décrits dans la littérature. Nous rapportons le cas d’une ...patiente de 8 ans, sans antécédent. Elle présentait une douleur brutale de la main gauche sans notion de traumatisme ni de contexte infectieux. La radiographie retrouvait une lésion ostéolytique, diaphysaire du 4
e métacarpien. La scintigraphie objectivait un foyer d’hyperfixation localisé à la main et l’IRM une atteinte des métacarpiens adjacents. Le bilan biologique ainsi que la biopsie ne retrouvaient pas d’argument pour une étiologie infectieuse, inflammatoire, tumorale ou endocrinienne. La confrontation des données cliniques, radiologiques et histologiques a permis de retenir le diagnostic de maladie de Gorham-Stout. Une simple surveillance a été décidée, mettant en évidence une ostéolyse s’étendant en tâche d’huile à toute la main puis à l’avant-bras. Des cures de biphosphonates (Zometa
®) bisannuelles ont été réalisées. À 8 ans de recul, la patiente présente une infiltration lymphoedémateuse des tissus mous indolores ainsi qu’une perte progressive de la fonction la main, avec une évolution qui semble stabilisée.
•The food industry uses silver nanoparticles as sensors, dietary supplements, additives, and in packaging.•They represent a potential risk of toxicity to the consumer, the intestinal tract and liver ...being their main targets.•Silver nanoparticles can produce free radicals and cause oxidative stress in cells, inducing oxidative damage.•Oxidative stress mediates toxicity by triggering inflammatory reactions and death by necrosis or apoptosis.
Because of their antimicrobial properties, the use of silver nanoparticles (AgNPs) is increasing fast in industry, food, and medicine. In the food industry, nanoparticles are used in packaging to enable better conservation products such as sensors to track their lifetime, and as food additives, such as anti-caking agents and clarifying agents for fruit juices. Nanoemulsions, used to encapsulate, protect and deliver additives are also actively developed. Nanomaterials in foods will be ingested and passed through the digestive tract. Those incorporated in food packaging may also be released unintentionally into food, ending up in the gastrointestinal tract. It is therefore important to make a risk assessment of nanomaterials to the consumer. Thus, exposure to AgNPs is increasing in quantity and it is imperative to know their adverse effects in man. However, controversies still remain with respect to their toxic effects and their mechanisms. Understanding the toxic effects and the interactions of AgNPs with biological systems is necessary to handle these nanoparticles and their use. They usually generate reactive oxygen species resulting in increased pro-inflammatory reactions and oxidative stress via intracellular signalling pathways. Here, we mainly focus on the routes of exposure of AgNPs, toxic effects and the mechanisms underlying the induced toxicity.
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