Percutaneous cementoplasty of periprosthetic aseptic hip loosening.

Progressive population aging and improved healthcare have led to a significant increase in patients with hip arthroplasty (HA). In this patient group, the proportion of those who require a new arthroplasty (prosthetic replacement or secondary revision of the hip), has also increased. For this subgroup of patients in whom surgical prosthetic replacement should be considered but is contraindicated, a new technique has been developed since 2010: percutaneous injection of periprosthetic cement under fluoroscopic or CT control ("femoroplasty; FMP") as an alternative and less invasive treatment compared to surgery to stabilize the HA without replacing it, with excellent results on patients' quality of life. In this brief communication, we describe our positive experience regarding FMP, which we have performed for the first time in Spain on four patients (age range between 74-83 years, 2 female and 2 male patients, 3 right HA and 1 left HA), without post-complications. We highlight both the relative simplicity of this technique, which can be incorporated into radiological intervention even in regional hospitals, and the significant clinical improvement observed in all patients. In conclusion, we hope that our experience can contribute to the increased adoption of this innovative technique within the scientific community.

Exchange-bias phenomenon: the role of the ferromagnetic spin structure.

The exchange bias of antiferromagnetic-ferromagnetic (AFM-FM) bilayers is found to be strongly dependent on the ferromagnetic spin configuration. The widely accepted inverse proportionality of the exchange bias field with the ferromagnetic thickness is broken in FM layers thinner than the FM correlation length. Moreover, an anomalous thermal dependence of both exchange bias field and coercivity is also found. A model based on springlike domain walls parallel to the AFM-FM interface quantitatively accounts for the experimental results and, in particular, for the deviation from the inverse proportionality law. These results reveal the active role the ferromagnetic spin structure plays in AFM-FM hybrids which leads to a new paradigm of the exchange bias phenomenon.

SiO2 coating effects in the magnetic anisotropy of Fe3-xO4 nanoparticles suitable for bio-applications.

We present radio frequency transverse susceptibility (TS) measurements on oleic acid-coated and SiO2-coated Fe3-xO4 magnetite nanoparticles. The effects of the type of coating on the interparticle interactions and magnetic anisotropy are evaluated for two different particle sizes in powder samples. On the one hand, SiO2 coating reduces the interparticle interactions as compared to oleic acid coating, the reduction being more effective for 5 nm than for 14 nm diameter particles. On the other hand, the magnetic anisotropy field at low temperature is lower than 1 kOe in all cases and independent of the coating used. Our results are relevant concerning applications in biomedicine, since the SiO2 coating renders 5 and 14 nm hydrophilic particles with very limited agglomeration, low anisotropy, and superparamagnetic behavior at room temperature. The TS technique also allows us to discriminate the influence on the anisotropy field of interparticle interactions from that of the thermal fluctuations.

The fabrication of ordered arrays of exchange biased Ni/FeF2 nanostructures.

The fabrication of ordered arrays of exchange biased Ni/FeF(2) nanostructures by focused ion beam lithography is reported. High quality nano-elements, with controlled removal depth and no significant re-deposition, were carved using small ion beam currents (30 pA), moderate dwell times (1 micros) and repeated passages over the same area. Two types of nanostructures were fabricated: square arrays of circular dots with diameters from 125 +/- 8 to 500 +/- 12 nm and periodicities ranging from 200 +/- 8 to 1000 +/- 12 nm, and square arrays of square antidots (207 +/- 8 nm in edge length) with periodicities ranging from 300 +/- 8 to 1200 +/- 12 nm. The arrays were characterized using scanning ion and electron microscopy, and atomic force microscopy. The effect of the patterning on the exchange bias field (i.e., the shift in the hysteresis loop of ferromagnetic Ni due to proximity to antiferromagnetic FeF(2)) was studied using magneto-transport measurements. These high quality nanostructures offer a unique method to address some of the open questions regarding the microscopic origin of exchange bias. This is not only of major relevance in the fabrication and miniaturization of magnetic devices but it is also one of the important proximity phenomena in nanoscience and materials science.

Surface anisotropy broadening of the energy barrier distribution in magnetic nanoparticles.

The effect of surface anisotropy on the distribution of energy barriers in magnetic fine particles of nanometer size is discussed within the framework of the Tln(t/τ(0)) scaling approach. The comparison between the distributions of the anisotropy energy of the particle cores, calculated by multiplying the volume distribution by the core anisotropy, and of the total anisotropy energy, deduced by deriving the master curve of the magnetic relaxation with respect to the scaling variable Tln(t/τ(0)), enables the determination of the surface anisotropy as a function of the particle size. We show that the contribution of the particle surface to the total anisotropy energy can be well described by a size-independent value of the surface energy per unit area which permits the superimposition of the distributions corresponding to the particle core and effective anisotropy energies. The method is applied to a ferrofluid composed of non-interacting Fe(3-x)O(4) particles of 4.9 nm average size and x about 0.07. Even though the size distribution is quite narrow in this system, a relatively small value of the effective surface anisotropy constant K(s) = 2.9 × 10(-2) erg cm(-2) gives rise to a dramatic broadening of the total energy distribution. The reliability of the average value of the effective anisotropy constant, deduced from magnetic relaxation data, is verified by comparing it to that obtained from the analysis of the shift of the ac susceptibility peaks as a function of the frequency.

Depth profile of uncompensated spins in an exchange bias system.

We have used the unique spatial sensitivity of polarized neutron and soft x-ray beams in reflection geometry to measure the depth dependence of magnetization across the interface between a ferromagnet and an antiferromagnet. The net uncompensated magnetization near the interface responds to applied field, while uncompensated spins in the antiferromagnet bulk are pinned, thus providing a means to establish exchange bias.

Allergic eosinophilic gastroenteritis in a child with Crohn's disease.

A case of a child with Crohn's disease who developed an eosinophilic gastroenteritis is reported. Although symptoms of eosinophilic gastroenteritis at age 8 could mimic those of Crohn's disease, laboratory, radiographic and histologically studies are clearly different. Peripheral blood eosinophilia (7,476 cells per mm3), high serum IgE level (1,050 kU/l) and normal C-reactive protein and erythrocyte sedimentation rate are common in eosinophilic gastroenteritis and uncommon in Crohn's disease. Eosinophilic gastroenteritis was due to bovine serum albumin (BSA) hypersensitivity, confirmed with skin tests, serum levels to specific IgE and a SDS-PAGE IgE-immunoblotting. A strict meat-free diet was started, with progressive relief of symptoms and decrease of eosinophil count twelve months later; the patient became fully symptom-free and eosinophil count was normal.

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[Cervical uterus septus. Atypical malformation as a cause of sterility]. / Utérus cloisonné cervical. Malformation atypique comme une cause de stérilité.

A review of the congenital anomalies of the feminine genital apparatus has been carried out with regard to the infrequent finding of a selective septum in cervix with a single uterine cavity and normal morphology in a patient with primary sterility. Colposcopy, hysterosalpingography and laparoscopy have been made for diagnosis confirmation.

[Bull's eye radiologic lesions in lymphoma of the stomach. Apropos of 2 cases]. / Lesiones radiológicas en ojo de buey en el linfoma gástrico. A propósito de dos casos.

We present two cases of gastric lymphoma with radiologic bull's eye lesions in the stomach. One of the patients also had an intestinal leiomyosarcoma that was resected surgically. We underline the rarity of the occurrence of this type of image as a gastrointestinal manifestation of lymphoma, as well as its scant specificity.

Chromosome abnormalities in peripheral blood lymphocytes from untreated Hodgkin's patients. A possible evidence for chromosome instability.

We describe the presence of a high frequency of spontaneous chromosome aberrations in lymphocytes from six untreated patients with Hodgkin's disease. The characteristics of the chromosome abnormalities observed suggest the existence of a certain degree of chromosome instability in these cases, that could be a predisposing factor for the development of malignancies.