Search

Grazing incidence x-ray reflectivity (GIXRR) technique is commonly used for structural investigation of layered structures. In case of complex x-ray waveguide structure it is difficult to obtain structural parameters using GIXRR technique owing to narrowly spaced Kiessig fringes. We used GIXRR and soft x-ray reflectivity (SXR) technique to study the x-ray waveguide structure composed of 4 layers Al/ZrC/Al/W on a Si substrate. Structural parameters of the stacks, density, thickness and roughness of the layers, are determined through fitting of SXR data. Advantages of SXR over GIXRR for such layered structure are shown.

The results of experimental investigation of parametric radiation generated by 5.7 MeV electrons in a multilayer structure consisting of 100 Cr/Sc bi-layers deposited on a Si[3]N[4] membrane are presented. The multilayer structure was specially created for generation of parametric radiation with photon energy in "water-window" spectral range. First test measurements of angular distributions of radiation have been done and discussed.

Granulocytic sarcoma (GS) is a rare extramedullary tumor frequently associated with acute myeloblastic leukemia (AML). We report 3 cases of pediatric granulocytic sarcomas with various locations: skin, orbit, and bowel. Cases 1 and 2 were associated with AML; case 3 was isolated. In all 3 cases, the diagnosis was delayed or initially missed. Pathology and immunohistochemistry data identified the disease. GS is treated with chemotherapy, like AML. The prognosis of GS seems better than that of isolated AML.

Objectives Retrospective analysis of the efficiency of a protocol for care of chronic vegetative states (CVS) and minimally conscious state (MCS) in Lorraine. Material and method Two indicators are used: protocol activity (number of patients hospitalized between 1988 and 2006, number of admissions per year, of requests per year, origin of requests, waiting time) and the epidemiological data (age, sex ratio, etiology, length of stay, geographic origin, number of deaths, number of hospital discharges). The number of CVS and MCS and patients having progressed towards arousal is specified as well as the technical procedures (orthopedic surgery, number of tracheotomies). Results Forty-seven patients (30 males and 17 females) were hospitalized in a 12-bed unit. The number of admissions per year was 2.4, and the annual number of requests varied between five and 15. Hospitalization times ranged from six to 18 months. The average length of hospitalization was 41 months. Eighty-eight percent of the cases were residents of Lorraine. The etiology was traumatic (53%), vascular (38% including 12% anoxia), miscellaneous (9%). Fifteen percent rate of return to arousal (average time period: 28.41 months, traumatic etiology) with hospital discharge in four cases. Conclusion The protocol is managed as part of a local scheme and enables an appropriate response to a specific clinical profile by providing up-to-date multidiscipline follow-up care and a rapid solution should intercurrent events occur (signs of arousal, orthopedic deterioration, change of environment). Typical limitations are geographical remoteness and difficulties with family support care.

Hip dynamics in the intact limb during the beginning of stance phase in unilateral trans-tibial amputees (TTA) was studied to evaluate its contribution to compensatory function. We hypothesized (1) an increase in hip total work during H1 power phase (0-30% of gait cycle) including an initial negative phase and (2) an intensification of the hip work in response to uncomfortable gait induced by prosthesis misalignment. Three-dimensional gait analysis was conducted in 17 unilateral TTA and 15 healthy subjects walking at the same self-selected speed in three prosthetic alignments: initial alignment (IA); IA altered either by 6 degrees of internal rotation (IR) or by 6 degrees of external rotation. Patients reported best comfort of gait in IA condition and discomfort mainly in IR condition. During the H1 power phase, in intact limbs a consistent initial flexion movement of the hip (0-8% gait cycle) was associated to negative work and was followed by hip extension and positive work whereas in both prosthetic and control limbs only hip extension and positive work occurred (except in one healthy individual). Absolute value of hip work during H1 phase was significantly higher in intact and prosthetic limbs compared to control limbs in IA condition and was further significantly increased in IR condition only in intact limbs demonstrating a compensatory function of the latter. In intact limbs, early hip negative work contributed to energy absorption in addition to the knee joint probably to compensate the lower energy absorption exerted by the prosthetic limbs.

Nocardiosis is a rare infectious disease in children. We report here a disseminated nocardiosis in a child with acute lymphoblastic leukemia. The patient presented prolonged febrile neutropenia and nodular pneumopathy. Based on the amplification of a 16S rDNA, a PCR assay detected Nocardia sp. in the patient's bronchoalveolar lavage (BAL) fluid. Culture of BAL samples yielded Nocardia nova colonies after 2 weeks of incubation. Hepatic, splenic, renal and cerebral localisations were detected on extension checkup. trimethoprime-sulfamethoxazole and amikacine were started given the results of PCR assay, with a good response. Improvement of the patient's general condition led to complete chemotherapy under ciprofloxacine and ceftriaxone treatment, without nocardiosis reactivation. Nocardiosis is a rare complication in children with acute lymphoblastic leukemia. trimethoprime-sulfamethoxazole prophylaxis is widely used to prevent Pneumocystis jiroveci infection in children with haematologic malignancies. As Nocardia species are usually sensible, trimethoprime-sulfamethoxazole could play a role in Nocardia prophylaxis in such population. In our patient, compliance with trimethoprime-sulfamethoxazole had been low. Nocardia species are relatively fastidious growth bacteria and are difficult to isolate with classical bacteriological techniques. Molecular methods are now available, with a good sensitivity and fast results allowing to start an appropriate antibiotherapy before culture results, as early treatment is a major prognosis factor in nocardiosis. Nocardia infection should be suspected in case of nodular pneumopathy in immunocompromised children. An extension checkup should be performed to detect secondary localisations.

Etched and coated multilayer gratings and simple multilayers are investigated by means of x-ray scattering (XRS) and grazing x-ray reflectivity (XRR). Two types of gratings are studied: one lamellar grating coated by a La/B4C stack and two lamellar gratings etched in a Mo/B4C multilayer structure with different cyclic ratios. XRS measurements are presented as reciprocal space mappings or Q-mapping and the origin of the different structures observed in the Q-mapping are discussed in terms of typical coherent and diffuse scattering processes (Bragg spots, grating-Bragg spots, Bragg sheets, grating diffuse sheets, Yoneda wings, etc). From the XRS and XRR measurements, some structural parameters of the mirrors and gratings such as periods and roughness characteristics are estimated.

Artificially fabricated multilayers that exploit the effect of Bragg diffraction at long wavelengths are used as X-ray optical components. Periodic ultrathin bilayer stacks of, alternatingly, a metallic reflection layer and a non-metallic spacer layer prepared as @mm-scaled surface grating promise particularly high performance in applications as X-ray filters for high-resolution spectroscopy. Such gratings can be prepared by multilayer deposition onto Si(001) gratings or by coating flat Si(011) substrate surfaces with a multilayer, followed by subsequent etching of a grating structure. The structural quality of ultrathin multilayer gratings of both types has been characterized quantitatively combining TEM bright-field imaging of specimen cross-sections and applying a geometric phase method. The geometric phase method has been originally developed for the analysis of local displacement fields from HREM images and allows to obtain the relevant structure parameters. The application of this method to the characterization of Mo/B"4C and La/B"4C multilayer systems shows that the functionally decisive structure parameters, such as layer perfection, layer periodicity, and layer orientation, can be obtained with high precision from evaluation of TEM bright-field images. The essential role of such data analyses for a quantitative characterization of multilayer systems and for optimising the layer deposition techniques in the fabrication of X-ray optical layer systems will be demonstrated and discussed.

Multilayer interference mirrors (MIMs) are widely used as low-resolution monochromators for soft x-ray wavelength dispersive spectrometry (WDS). It is now possible to fabricate multilayer monochromators with medium resolution by etching MIMs with a large number of bilayers according to the profile of a lamellar grating. It will be shown both theoretically and experimentally that these multilayer gratings with appropriate characteristics can be used as monochromators for soft x-rays, whose spectral resolving power is considerably improved with respect to mere interference mirrors. Moreover, tunable soft x-ray sources based on the interaction of medium-energy electron beams with periodic multilayer structures are presently being developed in several countries. The physical processes involved in this type of sources belong to the class of quasi-Cerenkov emission. Among them are resonant transition radiation and parametric radiation. We present the basic concepts and the first experimental results concerning this new type of sources which should be very interesting for WDS.

Degenerative osteoarthritis in subtalar and midtarsal joints occurring after tibiotalar arthrodesis may be related to biomechanical factors. For patients with tibiotalar arthrodesis walking with their everyday shoes, the ground reaction force is posterior at heel-off and the maximal foot-tibia dorsiflexion is at its upper limit. We hypothesized that increasing the instep of the shoes would improve these abnormalities. Three-dimensional gait analysis was done in nine patients with ankle arthrodesis fused in the neutral position and for 10 control subjects. Four conditions of walking were tested: barefoot, wearing everyday shoes, wearing everyday shoes with the instep increased by 1 cm, and wearing everyday shoes with the instep increased by 2 cm. In the arthrodesis group, the two modified delayed heel-off shoe conditions shifted the ground reaction force closer to the metatarsal heads at heel-off to a normal range, and reduced the maximal foot and tibia dorsiflexion angle. Based on these results, patients with a tibiotalar arthrodesis in the neutral sagittal position may be advised to choose shoes with an instep of approximately 25 mm.

Publié dans The European Physical Journal - Applied Physics 31, 147 (2005); International audience; A new laboratory apparatus devoted to the characterization of various devices for the X-UV range (100-5000 eV), such as mirrors, diffraction gratings, spectrometers or detectors is described. The apparatus includes open x-ray tubes as x-ray sources, a two-crystal monochromator for wavelength selection and a goniometer. Various examples of its use are presented : dispersive mode where the radiation coming from the x-ray tube is dispersed by the two-crystal monochromator, spectrometric mode where the goniometer is used as a plane x-ray spectrometer and reflectometric mode where a selected wavelength is used to perform absolute reflectivity measurements.

Paysant J, Andre J-M, Martinet N, Beis J-M, Datie A-M, Henry S, Dap F. Transcranial magnetic stimulation for diagnosis of residual limb neuromas. Arch Phys Med Rehabil 2004;85:737–42. Objective To analyze the mechanism and examine the potential diagnostic contribution of transcranial magnetic stimulation (TMS) in diagnosing painful, clonic, and/or autonomic manifestations in amputees' residual limbs. Design Prospective study. Setting Regional rehabilitation institute at a medical school in France. Participants Thirty-four amputees (24 with myoclonus, stump pain, or trophic skin disorders; 10 controls with no stump symptoms). Interventions Not applicable. Main Outcomes Measures TMS performed before and after correcting prosthesis adaptation. Results TMS induced pain in 12 amputees, clonic manifestations in 4, and autonomic manifestations in 2. Twelve patients underwent magnetic resonance imaging that showed neuromas in all 12. After neuroma resection in 9 amputees, TMS no longer provoked abnormal manifestations. TMS did provoke abnormal manifestations after resection in 3 patients who had postoperative recurrent neuromas. The response to TMS was negative in subjects with a clinically silent neuroma (n=7). The response was also negative in all patients with other stump anomalies whose clinical manifestations fully regressed after conservative treatment. There was a highly significant correlation between the presence of a pathologic neuroma and TMS-induced abnormal manifestations ( P Conclusions TMS can provoke symptoms in patients who experience spontaneous or evoked symptoms related to a neuroma. Induced symptoms are proportional to spontaneous symptoms. Removing the neuroma can stop stump symptoms and reverse the TMS effect. The response to TMS was negative in the control subjects with clinically silent neuromas; conservative treatment was successful in these cases. TMS-induced abnormal manifestations underlying mechanisms are discussed (ephaptic transmission in neuromas).

Foisneau-Lottin A, Martinet N, Henrot P, Paysant J, Blum A, Andre J-M. Bursitis, adventitious bursa, localized soft-tissue inflammation, and bone marrow edema in tibial stumps: the contribution of magnetic resonance imaging to the diagnosis and management of mechanical stress complications. Arch Phys Med Rehabil 2003;84:770-7 Objective: To assess the contribution of magnetic resonance imaging (MRI) in the diagnosis of tibial stump bursitis, in the establishment of differential diagnosis, and in the therapeutic management prosthetic-stump interface, mainly by adaptation of the prosthetic device. Design: Two-year, prospective, consecutive series. Setting: University-affiliated prosthetic and rehabilitation center and university department of radiology. Participants: A group of 17 persons with stump problems identified from a total of 139 consecutive below-knee amputees with prosthesis problems. Interventions: Not applicable. Main Outcome Measures: Clinical symptoms and MRI. Results: Clinical symptoms (variable stump volume, fluctuating mass at palpation with or without mechanical pain) were suggestive of bursitis in 10 patients. MRI confirmed bursitis in 9 and identified 1 in whom clinical signs suggested neuroma, giving an incidence of 10 of 139 amputees (7.2%). MRI identified 13 sites of bursitis (adventitious bursa, 11; synovial bursitis, 2) and 5 localized areas of soft tissue inflammation. MRI showed diffuse muscular edema at 1 site of clinically suspected bursitis, and bursitis at another site of suspected neuroma. Calcified bursitis was observed in 1 case. Bone abnormalities associated with bursitis (n=7) included osteophytes or fracture (n=4) or bone marrow edema (n=3). Two asymptomatic neuromas were also identified. MRI-guided modifications of the prosthetic interface led to favorable outcome in all cases. Conclusion: Bursitis, adventitious bursae, and areas of localized soft-tissue inflammation are different aspects of the same disorder resulting from a mechanical conflict between the stump and the prosthesis socket. Besides contributing to diagnosis, MRI provides a precise assessment necessary for correcting the prosthesis-stump interface in a way that reduces mechanical stress and subsequently cures bursitis.

Resume OBJECTIF : Evaluer les benefices apportes par une chirurgie precoce des escarres pelviennes par rapport a la cicatrisation dirigee dans une population de sujets medullo-leses. MATERIEL ET METHODE : La population etudiee est constituee de 53 patients (62 escarres) repartis en deux groupes : le groupe 1 comprend 30 patients (34 escarres) presentant des escarres pelviennes de stade III ou IV (NPUAP) traitees en premiere intention chirurgicalement, inclus consecutivement pendant une periode de 2 ans ; le groupe 2 comprend 23 patients (28 escarres) inclus de facon retrospective presentant des escarres pelviennes de stade III ou IV traitees en premiere intention par cicatrisation dirigee par la meme equipe de soins. Les criteres de jugement retenus sont le delai de cicatrisation et le delai de reprise de la station assise au fauteuil. L’analyse statistique fait appel au calcul de l’ecart reduit. RESULTATS : Dans le groupe 1 le delai moyen de cicatrisation quelle que soit la localisation de l’escarre est de 42 jours et le delai moyen de remise au fauteuil de 39 jours. Dans le groupe 2 la cicatrisation ne peut etre obtenue medicalement que dans 13 cas et dans un delai moyen de 180 jours. Les differences sont statistiquement significatives (p DISCUSSION - CONCLUSION : L’originalite de cette etude resulte dans la comparaison de deux traitements au sein de deux groupes de patients ayant des caracteristiques demographiques proches. Elle demontre clairement l’interet de la chirurgie precoce de l’escarre par rapport a la cicatrisation dirigee et illustre la necessite de filieres medico-reeducatives specialisees.

We realized a laterally-d graded multilayer interference mirror using a special configuration of a sputtering deposition system. Metrology of this device was done (we have found the variation of period versus the lateral position) on the SB3 beamline, a CEA calibration station located at the ‘Laboratoire pour l’Utilisation du Rayonnement Electromagnetique’ in Orsay. A wide set of applications was shown by studying transmission of X-ray radiation transmitted through copper metal foil, especially spectral analysis in the L absorption edge. This analysis was simply realized by translating the laterally-d graded multilayer interference mirror at a fixed glancing angle.

We propose a method to reduce the bandpass of soft x-ray multilayer Bragg reflectors. It consists in etching down to the substrate a multilayer mirror having a large number of bilayers in order to get a lamellar grating with a multilayer bar width representing only 10%–30% of the grating period. The grating is used at the zeroth diffraction order. Once designed, this monochromator was tested with the Lα,β spectra of iron and copper.

The influence of the number of bilayers on the optical performances of actual X-UV multilayer interferential mirrors (MIMs) has been studied in order to emphasize the experimental restrictions in the designing of “thick” mirrors used for the development of etched multilayer gratings. Several sets of samples (W/C, Mo/Si) with increasing number of bilayers have been manufactured in the very same conditions by means of a sputtering technique. X-ray diffraction characterization at Cu-Kαradiation (λ = 1.54018 A) exhibits technical constraints in the achievement of multilayer structures with large number of bilayers. We obtain a gradual loss of reflectivity for deposition times greater than 1h 30 min to 2h without significant drift of the MIM's geometrical parameters (period and division parameter). In the same time, absolute reflectivity measurements at Cu-Lαradiation (λ = 1.333 nm) emphasize satisfying optical and spectroscopic performances of W/C thick samples (150 bilayers).

This paper was published in Chinese Optics Letters and is made available as an electronic reprint with the permission of OSA. The paper can be found at the following URL on the OSA website: http://www.col.org.cn/abstract.aspx?id=COL201311S10601-04. Systematic or multiple reproduction or distribution to multiple locations via electronic or other means is prohibited and is subject to penalties under law.; International audience; We use complementary analysis techniques to determine the structure of nanometric periodic multilayers and particularly their interfaces. We focus on Co-based multilayer which can be used as efficient optical component in the extreme ultraviolet (EUV) range. The samples are characterized using reflectivity measurements in order to determine the thickness and roughness of the various layers, X-ray emission and nuclear magnetic resonance (NMR) spectroscopies to identify the chemical state of the atoms present within the stack and know if they interdiffuse. Results are validated through the use of destructive techniques such as transmission electron microscopy or secondary ion mass spectrometry.

Multilayer gratings developed since the end of the ninethies are now used for various purposes in x-uv optics: polychromator, narrow bandpass monochromators…We have implemented the Coupled-Mode Theory (CMT) to calculate the performances of these devices (efficiencies, bandwidths…) especially for quasi-lamellar gratings with different shapes of the multilayer pitch. We have fabricated such gratings and compared CMT calculations with measurements obtained at the BEAR beamline of ELETTRA.

B4C/W multilayer mirrors designed for an x‐ray beamline at the MEGAJOULE facility are susceptible to x‐ray damage. The OCTAL laser was implemented to generate a gold plasma with a continuous x‐ray spectrum (0.1 to 1.5 keV) used to irradiate the mirror. The fluence on the sample is 0.05 J/cm2 per shot. The pulse duration is about 1 ns. The temporally integrated spectrum reflected by the mirror is analyzed by a bent crystal spectrometer and recorded on photographic film. The spectral analysis suggests that an increase of the mean period of the multilayer happens during the second shot. This expansion is estimated to be 5% with respect to the unexposed mirror. After the second shot, destruction of the multilayer coating in the central part of the sample and irreversible damages in the other part characterized by a decrease of Bragg reflectivity have been observed.

We study a periodic Co/Mo2C multilayer prepared by magnetron sputtering. The period is 4.1 nm and the sample is designed to work around 778 eV, i.e. close to the Co 2p3/2 threshold, at a glancing angle of 11°. In this condition, strong x-ray standing waves set up within the sample. In order to probe different depths within the stack, particularly the interfaces, the glancing angle is moved along the first Bragg peak, while, the B 1s, C 1s, Mo 3d or O 1s photoelectron spectra, the Co Lα x-ray spectrum as well as the drain current of the sample are measured. Boron is present in the 3.5 nm B4C capping layer and oxygen is from surface contamination. The photoelectrons bring information from the superficial zone, i.e. the 5 first nm, while the characteristic x-rays probe the whole stack. Clear modulations of the intensity of the studied signals as well as core level shifts are observed when going through the Bragg peak. In order to understand what happens in the multilayer calculations of depth distributions of the electric field and the energy loss by the radiation are made with the IMD and OPAL codes, respectively. The combination of experimental results and theoretical simulations will enable us to determine from which place originate the various signals and to know if some interaction exists between the Co and Mo2C layers.

We describe an instrument designed for studying the electronic structure of bulk, surface, and deep solid–solid interface. The analysis is made by soft‐x‐ray emission spectroscopy induced by electron bombardment. The target is placed under ultrahigh vacuum and can be prepared and treated in situ. High resolution is achieved both as concerns the photon energy and the electron‐beam energy. Tests have been made in the dispersive mode and in the characteristic isochromat mode. In both cases experimental resolution is in good agreement with the expected one.

The principle of Bragg-Fresnel multilayer lenses is given. The techniques of manufacturing are summarized. The performances of these optics are discussed. Examples of application and perspectives concerning their development are presented.

Study design: Prospective study. Objectives: To determine the mechanisms of body illusions in paraplegia patients as compared with the amputee phantom phenomena. Methods: A vestibular caloric stimulation was performed in 10 consecutive patients with complete section of the spinal cord. Perception of body, before and after stimulation, was classed as illusion of a normal body (lower limbs with normal morphological, postural and kinetic characteristics perceived as before spinal injury), normal phantom (overly vivid perception of all or part of the lower limbs), deformed phantom (perception of all or part of the limbs below the injury level as abnormal in shape, posture, movement or even number), or painful phantom. Results: After vestibular caloric stimulation, nine out of 10 patients stated their perception of body segments below the injury level had changed to normal phantoms or to deformed phantoms (morphological, postural or kinetic changes). Among the four patients who initially had painful limbs, two stated the stimulation greatly relieved their pain. Conclusion: The normal or deformed phantom evoked by vestibular stimulation would result from use of identity data or instantaneous data as is observed in amputees. Cerebral remapping following deafferentation could be the origin of the deformed phantoms. Illusions corresponding to phenomena perceived at the time of the accident corresponding to autobiographical engrammes do not appear to be evoked by vestibular stimulation, as is also the case in amputees. Spinal Cord (2001) 39, 85–87.

A new material combination namely Co/Mg multilayer designed for optics applications in the EUV range, is reported. Simulations show that reflectivity value of the Co/Mg multilayer can reach a reflectivity of 55% at 25.2 nm (49.2 eV), when the grazing incidence angle is set to 45° and s polarization is considered. The introduction of additional materials, e.g., Y and Zr can improve the reflectivity to 61%. Co/Mg and Co/Mg/B4C multilayers have been deposited following the parameters deduced from the simulations. The introduction of a B4C barrier layer would in principle increase the multilayer reflectivity to 61%. In fact the reflectivity measurements at 0.154 nm show that the introduction of B4C does not improve the structural quality of the multilayers.

New x‐ray optics based on multidimensional diffraction are now available and have specific properties and potentials. Some characteristics of multilayer laminar amplitude gratings are presented in this work and exemplified with Mo/C multilayer etched gratings (1000 lines/mm) and (4166 lines/mm) for use in the 250 eV region and the 1 keV, respectively. The fabrication, tests of the gratings, and modeling of their diffractive performances are reported. Possible applications are discussed.

Mâaref K, Martinet N, Grumillier C, Ghannouchi S, Andre JM, Paysant J. Kinematics in the terminal swing phase of unilateral transfemoral amputees: microprocessor-controlled versus swing-phase control prosthetic knees. Objectives To analyze the spatiotemporal parameters in the terminal swing phase of the prosthetic limb in unilateral transfemoral amputees (TFAs) compared with a group of asymptomatic subjects, and to identify a latency period (LP) in the TFA between the full extension of the prosthetic knee and the initial ground contact of the ipsilateral foot. To study the correlation between the LP and the duration of the swing phase. To evaluate the influence of the type of knee, the time since amputation, and the amputation level on the latency period. Design Three-dimensional gait analysis with an optoelectronic device. Setting Gait analysis laboratory of a re-education and functional rehabilitation service. Participants TFA (n=29) and able-bodied (n=15) subjects. Interventions Not applicable. Main Outcome Measures Spatiotemporal and kinematics gait parameters. Results The swing phase and the LP of the prosthetic limb, associated with a consequently longer single-limb stance phase in the intact limb, were significantly longer than those measured in the intact limbs of these subjects, as well as those measured on both lower limbs of the able-bodied subjects ( P P r 2 =.58 between the LP and the swing phase on the TFA's prosthetic side. The LP measured in the prosthetic limb of TFA with a swing-phase control prosthetic knee is significantly greater than in those using the microprocessor-controlled prosthetic knee ( P Conclusions Of negligible duration in able-bodied subjects and in the intact limb of TFA, the LP is significantly greater in the prosthetic limb. It can explain the lengthened swing phase on the prosthetic side of those subjects. The use of a microprocessor-controlled prosthetic knee allows the LP to be reduced. This LP appears to be necessary to insure the stability of the prosthetic knee. We suggest calling this time "confidence time."

This study evaluated the asymmetry of knee kinetics during uncomfortable gait induced by prosthesis misalignment to further demonstrate the compensatory function of the knee joint of the intact limb during gait. Three-dimensional gait analysis including knee kinematics and kinetics at the beginning of stance phase was conducted in 15 healthy subjects and 17 unilateral trans-tibial amputees (TTA) walking at self-selected speed in three conditions of prosthetic alignment: initial alignment (IA); initial alignment altered either by 6 degrees of internal rotation (IR) or by 6 degrees of external rotation (ER) applied on the pylon. Patients reported best comfort of gait in IA condition and discomfort mainly in IR condition. Maximum knee flexion and knee total work at power phases K0-K2 were significantly higher in intact limbs compared to prosthetic and control limbs. In intact limbs, these variables had significantly higher values (+10-35%, p

We give the principle of a soft x-ray fluorescence spectrometer based on a multilayer interferential transmission plate. When using photographic films or charge coupled device arrays, the apparatus does not require mechanical displacement. We illustrate the method with the Kα emission line of silicon and aluminum samples.

OBJECTIVE: Violence to disabled persons constitutes a major ethical problem. The European Academy of Rehabilitation Medicine has debated the matter; it presents this short report to alert a wider audience to the problem, with the aim of provoking debate and facilitating prevention. DESIGN: The Academy has produced a full report on the literature. The present short report summarizes the essential features of this and significant references to violence. This is defined, types described, and risk factors and signs identified with the aim of informing rehabilitation practitioners. CONCLUSION: Violence may take many forms, often being subtle, insidious and difficult to recognize. However, the members of the rehabilitation team may be able to provide significant help and act preventively as they work towards the better social integration of the disabled individual helping them gain more control of their lives. European legislation may help us in this task; we are reminded that our roles are set within the context of our civic duties of respect for and tolerance of all.

To evaluate the feasibility and safety of totally robotic laparoscopic cystoprostatectomy for neurogenic bladder, with intracorporeal ileal-conduit urinary diversion in tetraplegic patients with severe neurogenic bladder complications.Two men, 41 and 38 years old, with complete post-traumatic C7-C8 quadriplegia and poor lower urinary-tract condition underwent totally transperitoneally performed cystoprostatectomy and ileal-conduit urinary diversion with robotic assistance (Da Vinci).The procedures were completed without open conversion. The total surgical time was 9.25 and 6.75 hours, respectively. There were no intraoperative complications. In the postoperative period, both patients had mild complications (pulmonary and urinary infections) that were treated successfully medically. The postoperative hospital stay was 13 days in both cases.Our results demonstrate the safety and feasibility of robot-assisted laparoscopic cystoprostatectomy with ileal-conduit urinary diversion in two tetraplegic patients.

International audience; A tunable monochromatic x-ray source covering the 1-20 keV energy range is described. The initial x-ray beam is obtained from a dedicated windowless x-ray tube. The energy selection is performed through a cylindrically bent crystal, used either in the reflection (Johann geometry) or in the transmission (Cauchois geometry) mode, by rotating the crystal holder by a 90° angle. Contrary to conventional geometries where the x-ray tube is fixed, here the direction of the exit beam impinging the x-ray detector is fixed. This setup is shown to be useful for various studies: high-resolution spectrometry, characterization of the response function and the efficiency of detectors and optical components, determination of transmission characteristics of different materials. Observations of the Lα line and Kα doublet from a copper anode are presented, that demonstrate the performance of this new setup.; Une source de rayons X monochromatique accordable dans le domaine de (1 à 20) keV est décrite. Le rayonnement est produit par un tube à rayons X sans fenêtre, fonctionnant entre (1 et 50) kV. La sélection en énergie est réalisée à l'aide d'un spectromètre à cristal courbé cylindriquement utilisable, soit dans le mode réflexion (géométrie Johann), soit dans le mode transmission (géométrie Cauchois). Le passage de l'une à l'autre de ces géométries se fait par simple rotation du cristal. La direction du faisceau monochromatique est fixe. Cet appareillage est utilisable à la fois comme spectromètre à haute résolution et comme monochromateur. Il a été spécialement conçu pour des études de métrologie, telles que la caractérisation de détecteurs et d'optiques du domaine X.

Objective. To assess the effect of internal foot progression angle (inturning) on knee dynamics in children with treated clubfeet. Design. Prospective study dividing a population of clubfeet according to the factor inturning. Background. Excessive internal or external foot progression angle increases knee flexion by a backward shift of the ground reaction force to the knee joint in children with cerebral palsy. Similarly, inturning in clubfeet was hypothesized to shift the ground reaction force backwards with reference to the knee joint, increasing the external knee flexion moment and the maximal knee flexion at stance. Methods. Three-dimensional gait analysis was performed on 20 children with surgically treated clubfeet (n=28) to assess alterations of knee dynamics related to inturning (>7°) and on 13 normal children. Results. Inturning occurred in 46% of the clubfeet and was associated during stance, at maximal knee flexion, to an increase in maximal knee flexion (+7°), external knee flexion moment (+60%) and related lever arm to the knee (+100%) and at minimal knee flexion, to a reduction in external knee extension moment (−62%) and related lever arm (−58%). Inturning was associated with a more frequent prolongation of internal knee extension moment and of rectus femoris activity exceeding 50% of stance. Conclusion. Inturning in clubfeet is associated with knee dynamics alteration, which might contribute to the long-term development of knee osteoarthritis. Relevance The therapeutic correction of inturning in clubfeet would be of importance if the consecutive knee dynamics alteration is shown by further studies to contribute to long-term degenerative knee pathology.

We report on the intensity modulation of the Si Κα line emitted from a Mo/Si multilayer as a function of the exit angle of the photons. The observation takes place around the direction corresponding to the Bragg diffraction of Si Κα by the multilayer. The sample is irradiated by an electron beam whose the energy is varied between 2 and 6 keV. An important intensity variation is observed within the angular range corresponding to the diffraction pattern of the emitting structure. A 15 % enhancement of the emitted radiation is measured in the Bragg direction of the multilayer, whatever the incident electron energy. This amplification is interpreted on the basis of the reciprocity theorem. A possible application as x‐ray resonator is suggested.

Foot anatomy and lower limb function were analyzed in 11 children (aged 6.5-12.5 y) 5 years after removal of one or two second toes for digital reconstruction. In addition to physical examination and x-rays, postural balance and three-dimensional measurements of gait were analyzed. Among the 15 operated feet, five had bridle scars, three had claw deformities of the third toe, five had pain in the first intermetatarsal space, and seven had overt or early-stage hallux valgus (including five after unilateral toe removal). Hallux valgus deformation was also observed in three nonoperated feet. Maintenance of balance and rate of displacement of the center of pressure when standing on one foot with eyes closed were significantly altered for operated limbs compared with nonoperated limbs. Gait was rapid because of increased step cadence. Foot progression angle and ankle and knee joint sagittal kinematics during walking were normal. Although children appeared to not be affected in their daily life by the removal of the second toe(s), related foot anatomic and functional modifications require further follow-up.

The difficulties confronted by amputees during overground walking are rarely investigated. In this study, we evaluated, in real-world situations, the influence of ground surface on walking in young, active amputees by measuring temporal and spatial gait parameters (free walking speed [FWS], step length [SL], step rate), energy expenditure (EE) (e.g., oxygen uptake, oxygen cost [O(2)C]), and Rating of Perceived Exertion (RPE). Ten active transtibial amputees and ten nondisabled control subjects walked at self-selected speeds on three types of ground surface (asphalt, mown lawn, and high grass). No significant differences were observed between the two groups on asphalt and mown lawn. Differences between nondisabled subjects and amputees occurred for FWS (p = 0.03) and O(2)C (p = 0.04) on asphalt and mown lawn and for all variables in high grass. When amputees (even though very active) were exposed to a particularly difficult environment, their FWS decreased (p = 0.008) and their EE and RPE increased (p = 0.005) compared with nondisabled subjects. In high grass, both groups reduced their self-selected speeds (-15% for control subjects and -16% for amputees). Control subjects reduced their velocity by reducing both SL (-8.7%) and cadence (-7.1%), whereas amputees reduced their velocity by reducing SL (-17%) only.

Urinary diversion is a therapeutic option in quadriplegic patients with poor lower urinary tract conditions, but it is an invasive procedure. Laparoscopic techniques are less invasive, but are technically demanding, and only a few surgical teams are able to complete such a complex procedure endoscopically. Robotics bring an unprecedented control of surgical instruments, shorten the learning curve, and allow open surgeons to apply more easily their technical skill to the laparoscopic approach. This complex case of laparoscopic ileal conduit in a quadriplegic woman was completed by our team with the Da Vinci system after 6 months of clinical experience in robotic surgery.

We apply a recursive propagation method to the modal theory of diffraction by laminar amplitude multilayer gratings (LAMG’s). We compute the reflection efficiency in the X-UV domain of several LAMG’s and show the numerical stability of this method with respect to a nonrecursive one.

A dynamical theory is given for calculating the performances of stratified Fresnel linear zone plates (SFLZP’s). The Born expansion extended to the Fresnel diffraction is used to prove a fundamental theorem giving the diffraction efficiency and the diffraction pattern of transmission or reflection SFLZP’s. The method is valuable as long as the wavelength is smaller than the characteristic parameter of the zone plate. It allows us to evaluate the performances of reflection multilayer SFLZP’s, i.e., the so-called Bragg–Fresnel optics recently developed for x-ray optics.

New devices combining the Bragg reflection from periodic multilayer structures with Fraunhofer or Fresnel diffraction arising from lateral patterning of the multilayer are now available for x-ray optics. Using the Green’s-function method, we establish an integral equation for the scattered amplitude that is valid in the framework of both Fraunhofer and Fresnel diffraction. The scattered amplitude is given in the first and the second Born approximations for multilayer mirrors, laminar and sawtooth-profile multilayer gratings, and linear multilayer zone plates. The main diffractive properties of these devices are deduced. The efficiencies are computed in the first and/or in the second Born approximation and are compared with efficiencies obtained from a rigorous electromagnetic theory when they are available.

Le granulome eosinophile de l'estomac est une affection rare a distribution geographique particuliere. Les auteurs rapportent un cas de granulome eosinophile a forme nodulaire, revele par une hemorragie digestive. L'interet de l'endoscopie est envisage dans la forme nodulaire de la maladie, la forme diffuse restant d'une approche diagnostique plus delicate.

A versatile X‐UV spectrogoniometer based on a modular system is described. The heart of the apparatus is a computer‐controlled θ‐2θ goniometer with 1.8 arcs θ angular resolution. This main unit can be connected to with a (+1, −1) double‐crystal premonochromator and a double‐mirror high‐frequency rejector. The dispersive performance of a multilayer interference mirror (MIM) and a lead stearate pseudocrystal are compared at three wavelengths: 13.3 A (Cu‐Lα), 44.8 A (C‐Kα), and 67.7 A (B‐Kα). The MIM appears as a useful dispersing device for a low resolution flat ‘‘one‐crystal’’ spectrometer in this spectral region.