Super-resolution and apodization with discrete adaptive optics.

High-resolution imaging is of great importance in various fields. The use of pupil phase-only filters (PPF) exceeds the diffraction limit of the imaging system in a simple way. When dealing with distorted wavefronts, however, PPF require that aberrations be compensated for. In this paper, we introduce a novel technique consisting of the use of discrete adaptive optics with PPFs so that the compensating device implements the PPF at the same time. Analysis of the theory for point spread function reshaping using PPFs has enabled us to develop a new approach to characterizing apodizing filters. A validation experiment has been carried out, the first of its kind to our knowledge, in which a number of PPFs were combined with two levels of compensation. Our experimental results are discussed.

Microfiltración apical entre tres cementos utilizados en obturación retrógrada / Apical microfiltration between three cements used in retrograde obturation

Objetivo: Determinar la microfiltración apical de tres cementos utilizados en obturación retrógrada. Métodos: 45 piezas unirradiculares estandarizadas a 16 mm de longitud se instrumentaron con sistema ProTaper ® manual e irrigaron con NaClO al 5,25%. Las muestras fueron obturadas con cono principal ProTaper ® F3 y accesorios Denstply ® #A y #B; se realizó la recesión apical de 3 mm, posteriormente se desobturó 3 mm con ultrasonido (Satelec Acteon) con punta s12/70D; se dividió la muestra en tres grupos para realizar obturación retrógrada con diferentes cementos de obturación cada uno. Las muestras se incubaron a 37 °C por 3 días; se cubrieron con barniz de uñas excepto 2 mm apicales para ser sumergidas en azul de metileno al 1% por 48 horas, se lavaron y reali- zaron un corte longitudinal con disco de diamante #2 para su análisis en el estereomi- croscopio (EduBlue ED 1402S), con la ayuda de un micrómetro (Stainless Hardened) se obtuvieron diferentes valores de cada grupo, mismos que fueron analizados por medio de la comparación de medias y pruebas paramétricas. Resultados: La valoración media de la microfiltración que produce la obturación retrógrada indica que: el MTA ® presentó un valor de 87,33 ± 9,61 µm (14,57%), seguido del Biodentine ® con 136 ± 12,42 µm (22,69%), con respecto al IRM ® con mayor cantidad de microfiltración con un valor de 376 ± 12,98 µm (62,74%). Conclusiones: Al comparar las medias y porcentajes de la microfiltración apical que presentan los cementos IRM ® , Biodentine ® y MTA ® , se evidenció que el MTA ® presentó el menor valor de microfiltración

Objective: To determine the apical microfiltration of three cements used in retrograde obturation. Methods: 45 monoradicular pieces standardized to 16 mm in length were instrumented with manual ProTaper ® system and irrigated with 5.25% NaClO. The samples were sealed with ProTaper ® F3 main cone and Denstply ® accessories #A and #B; an apical recession of 3 mm was performed, subsequently a 3 mm of obturation was removed with ultrasound (Satelec Acteon) using tip s12/70D; the samples were divided into three groups to perform retrograde filling, each with different sealing cements. The samples were incubated at 37°C for 3 days; then covered with nail varnish except 2 mm apical to be immersed in 1% methylene blue for 48 hours, washed and longitudinally cut with #2 diamond disc for analysis in the stereo microscope (EduBlue ED 1402S), with the help of a micrometer (Stainless Hardened); different values of each group were obtained, then analyzed through comparison of means and parametric tests. Results: The average evaluation of the microfiltration produced by the retrograde filling indicates that: the MTA ® presented a value of 87.33 ± 9.61 µm (14.57%), followed by the Bio- dentine ® with 136 ± 12.42 µm ( 22.69%), compared to the IRM ® with the highest amount of microfiltration with a value of 376 ± 12.98 µm (62.74%). Conclusions: When comparing the means and percentages of the apical microfiltration of the IRM ® , Biodentine ® and MTA ® cements; it was evident that the MTA ® showed the lowest microfiltration value.

Amplitude image processing by diffractive optics.

In contrast to the standard digital image processing, which operates over the detected image intensity, we propose to perform amplitude image processing. Amplitude processing, like low pass or high pass filtering, is carried out using diffractive optics elements (DOE) since it allows to operate over the field complex amplitude before it has been detected. We show the procedure for designing the DOE that corresponds to each operation. Furthermore, we accomplish an analysis of amplitude image processing performances. In particular, a DOE Laplacian filter is applied to simulated astronomical images for detecting two stars one Airy ring apart. We also check by numerical simulations that the use of a Laplacian amplitude filter produces less noisy images than the standard digital image processing.

Ossifying neuropathy of the median nerve at level of the distal forearm and carpal tunnel in a patient with familial history of heterotopic calcification.

We report an uncommon case of heterotopic ossification affecting the median nerve at the level of the distal forearm and carpal tunnel with some unusual features: its length, the concomitant involvement of the ulnar nerve at Guyon's canal and a positive family history of heterotopic ossification.

New diterpenes from the marine pulmonate Trimusculus peruvianus.

The family Trimusculidae produce labdane diterpenes, which differ in the degree and type of esterification with acetoxy and isovaleroyl ester, predominantly. In this article, we describe the isolation from the marine pulmonate Trimusculus peruvianus, collected on intertidal rocks of Chilean coasts, of two new labdane diterpenes closely related to the above mentioned characteristics. Their structures were determined by spectroscopic data and correspond to 6beta-hydroxy-labda-8, 13-dien-15-ol and 3, 19-isovaleroyl-6beta, 9alpha-dihydroxylabda-Delta(8,17), 13-dien-15-oic acid.

[An unusual manifestation of osteo-articular, tendinous and nervous involvement secondary to tophaceous gout of the hand. A report of two cases]. / Rare manifestation de lésion ostéoarticulaire, tendineuse et neurologique par goutte tophacée de la main. Deux cas cliniques.

Tophaceous gout of the hand is a rare condition, but possible in chronic cases. We report two cases (three hands) with a long history of hyperuricemia and serious lesions due to deposition of sodium urate crystals. In these cases we point out several fundamental aspects: the abnormal size of the tophi, the destruction of triquetum and pisiform, the digital joint instability due to ligamentous lesions, the tenosynovitis and digital flexion contracture secondary to intratendinous deposition of urates, and the presence of a double ipsilateral tunnel syndrome of the median and ulnar nerves at the wrist. After neurolysis and tophus resection, a rapid and very substantial relief of paraesthesiae was seen. Recovery of partial active wrist and finger movements required a variety of surgical interventions. The results are analysed after 2 years for the first case, and 8 months for the second.

Bone remodelling after total hip arthroplasty using an uncemented anatomic femoral stem: a three-year prospective study using bone densitometry.

PURPOSE: To evaluate the clinical, radiological, and densitometric changes in the bone-remodelling patterns of femoral stems aligned in neutral, valgus, or varus positions. METHODS: Between February and October 2000, 70 patients underwent unilateral total hip arthroplasty for primary osteoarthritis using an uncemented Anatomique Benoist Girard (ABG) II stem. 69 patients (30 males and 39 females) with a mean age of 59 years (range, 38-76 years) and a mean body weight of 79.3 kg (range, 29-110 kg) completed 3 years' follow-up on bone remodelling. The clinical, radiological, and densitometric changes of the neutral, valgus, and varus groups were evaluated, and the difference in bone-remodelling patterns between the 3 groups was analysed. RESULTS: 54 patients had neutrally placed stems, while varus and valgus malalignment occurred in 6 and 9 patients, respectively. Clinical and radiological evaluations were very similar among the 3 groups. Only densitometry could detect traceable changes resulting from the differing biomechanics of the neutral, varus, and valgus stem alignments. CONCLUSION: The ABG II stem design made moderate errors in alignment biomechanically tolerable. Alignment defects had no clinical consequences and resulted in minimal differences in bone remodelling.

Cambios en el remodelado óseo periprotésico tras el rediseño del vástago ABG: estudio densitométrico / Changes in periprosthetic bone remodelling after redesigning the ABG stem: densitometric study

Objetivo. Determinar la variación de masa ósea en dos versiones del mismo modelo de vástago femoral no cementado con objeto de cuantificar las diferencias atribuibles a un rediseño del implante con anclaje eminentemente metafisario. Material y método. Estudio prospectivo, controlado, en el que se analizan densitométricamente, durante un año, dos grupos de 36 pacientes afectos de coxartrosis primaria, con características biológicas semejantes, distribuidos según el equipo quirúrgico que llevó a cabo la intervención. Cada equipo utilizó uno de los implantes. Resultados. Las modificaciones introducidas en el vástago ABG-II consiguieron un patrón de remodelado óseo con mayor conservación del capital óseo en todas las zonas estudiadas. Las cifras de pérdida ósea son semejantes a las obtenidas con implantes hechos a medida. Conclusiones. El vástago ABG-II, de anclaje estrictamente metafisario, consigue un adecuado anclaje capaz de transmitir cargas al fémur proximal y minimizar la pérdida ósea por puenteo de fuerzas (stress shielding) (AU)

Tratamiento quirúrgico de las pseudoartrosis del húmero proximal mediante osteosíntesis con placa e injerto / Surgical treatment of nonunion of the proximal humerus by plate and bone graft

Objetivo. Evaluar el resultado del tratamiento de las pseudoartrosis del húmero proximal con placa e injerto.Material y método. Se han revisado retrospectivamente 8 pacientes con pseudoartrosis del cuello quirúrgico del húmero tratados mediante osteosíntesis con placa atornillada y autoinjerto de cresta ilíaca. Fueron 7 hombres y 1 mujer. La edad media fue de 54,8 años. La placa utilizada fue en 5 casos una placa AO en T, en 1 caso una placa Epiunion, y en 2 casos una placa Titania con dos tornillos dirigidos a la cabeza humeral. Los resultados funcionales fueron valorados según la escala de Constant-Murley y la escala de la Asociación Americana de Cirujanos del Hombro y del Codo (AASES).Resultados. La consolidación se obtuvo en todos los casos en una media de 12,1 semanas. Los resultados funcionales fueron satisfactorios en 4 casos. En otros 4 hubo una limitación de la movilidad y dolor subacromial (3 de ellos eran pacientes en los que se había utilizado una placa en T). Hubo un caso de pérdida de reducción en un paciente tratado con una placa Titania, aunque finalmente consolidó en varo.Conclusión. Aunque la serie es muy pequeña, la osteosíntesis con placa añadiendo injerto parece ser un método efectivo para conseguir la consolidación de la pseudoartrosis del cuello humeral. Las placas en T pueden producir frecuentemente un conflicto subacromial (AU)

Abdominal hernia through a defect in the iliac bone after resection of a chondrosarcoma of the pelvis.

Chondrosarcoma is a malignant tumor with, generally, a better prognosis than osteogenic sarcoma; it usually calls for surgical treatment with a wide margin of resection, in view of its marked resistance to chemo- and radiotherapy, but this may be difficult or impossible in one of its most frequent locations, i.e. the pelvis. Herniation of abdominal contents through a surgical defect in the iliac bone is a rare complication, and is almost always associated with bone graft harvesting from the iliac crest. We present the case of a male patient operated for a chondrosarcoma of the ilium, with wide resection of the tumor. During follow-up in the outpatient department, the existence of a hernia with intestinal contents through the defect created in the ilium was noted. The patient has now been followed for 10 years, and there have been no clinical repercussions of the hernia. No recurrence of the tumoral lesion has been observed. We review the cases published and discuss the treatments recommended.

Changes in the morphology of hip fractures within a 10-year period.

The objective of this study was to find out whether the morphology of various types of hip fractures and the mean ages of the patients had changed in a recent 10-year period. All patients aged 65 years or more with acute hip fracture admitted to Miguel Servet University Hospital in 1989-1990 (n = 457) and in 1999-2000 (n = 518) were studied. The results showed a significant increase in the incidence of displaced cervical fractures (P < 0.001) and a decrease in the incidence of nondisplaced cervical fractures (P < 0.001) in women. The incidence of different types of trochanteric fractures did not vary. No change was observed in the mean age of patients with cervical fractures, but the mean age of women with A12 trochanteric fractures was significantly higher in 1999-2000 than in 1989-1990 (P < 0.05).

Exoplanet detection using a nulling interferometer.

The detection of extra solar planets is a topic of growing interest, which stretches current technology and knowledge to their limits. Indirect measurement confirms the existence of a considerable number. However, direct imaging is the only way to obtain information about the nature of these planets and to detect Earth-like planets, which could support life. The main problem for direct imaging is that planets are associated with a much brighter source of light. Here, we propose the use of the nulling interferometer along with a photon counting technique called Dark Speckle. Using a simple model the behavior of the technique is predicted. The signal-to-noise ratio estimated confirms that it is a promising way to detect faint objects.

Non-Gaussian speckle statistics in adaptive-optics partial compensation.

Wave fronts distorted by the atmosphere can be partially reconstructed by use of adaptive-optics systems. The intensity statistics at the image plane is a function of the ratio D/r(0) and of the level of compensation performed by the adaptive-optics system. We show that a non-Gaussian statistics is obtained when the aperture diameter is slightly greater than the Fried parameter. This situation can frequently be found when one is working in the IR. The light statistics is obtained by use of a simple model to describe the atmosphere and application of the same procedure used in the analysis of scattered light. Special attention is paid to very high- and very low-compensation regimes.

Rician distribution to describe speckle statistics in adaptive optics.

Adaptive optics systems allow us to retrieve high-spatial-frequency information that is preserved in the wave fronts distorted by the atmosphere. Although wave-front correction should be as complete as possible, only partial compensation is attainable in the visible. We provide a procedure that uses the Rician distribution to predict the intensity statistics of the light at the image center as a function of the number of corrected Zernike polynomials.

Speckle statistics in partially corrected wave fronts.

Wave fronts distorted by the atmosphere preserve high-spatial-frequency information. This information can be retrieved by use of adaptive optics systems to correct the incoming wave front. This correction should be as nearly complete as possible. In experiments performed in the visible, only partial compensation is attainable. We provide a theoretical model to predict the intensity statistics of the light in the image center as a function of the number of Zernike polynomials corrected.