Familial pseudoxanthoma elasticum with nephrocalcinosis: a case report

Pseudoxanthoma elasticum (PXE) is an autosomal recessive genetic disorder characterized by progressive calcification and fragmentation of elastic fibres. PXE commonly involves the reticular dermis, the Bruch membrane of the eye, and blood vessels. PXE is caused by mutations in the ABCC6 gene. More than 300 pathogenic ABCC6 mutations are known. Two of these mutations are common: p.R1141X in exon 24, with a prevalence of 30%, and the Alu–mediated deletion of exons 23 to 29 (EX23_29del; p.A999_S1403del) found in 10-20% of patients. Homozygosity is rare. A 40-year-old female with a previous diagnosis of PXE was admitted in Nephrology Outpatient Clinic for nephrocalcinosis. She has two sisters, one of which also has a diagnosis of PXE and nephrocalcinosis. Physical examination revealed the presence of typical skin and ocular abnormalities. Microscopic and gross hematuria was reported in both affected sisters. Abdominal ultrasound confirmed bilateral cortico-medullar nephrocalcinosis. Calcium and phosphorus levels in blood and urine were normal. Hyperparathyroidism, renal tubular acidosis, hypervitaminosis D and hyperoxaluria were excluded. Renal biopsy showed only minor glomerular abnormalities. Medullary sponge kidney was identified by excretory urography. Genomic DNA was used as a template for PCR amplification of the region spanning introns 22 to 29 of ABCC6 [Pfendner et al., J Med Genet 2007;44:621-8]. The oligonucleotide cocktail used generated a 552bp PCR product for the normal sequence, and a 652bp product for the deletion mutation. Both sisters with PXE were homozygous for the EX23_29del mutation. The third sister did not carry this deletion. There are occasional reports of diffuse visceral calcifications (testis, mammary gland) in PXE. PXE-associated nephrocalcinosis was previously noted in four patients belonging to different families. This is the first report of familiar co-occurrence of PXE and nephrocalcinosis with medullary sponge kidney. These sisters’ peculiar phenotype could be due to their unusual genotype, or other shared genetic and environmental factors

Inter-laminar shear stress in hybrid CFRP/austenitic steel

Bolted joints are the most common solution for joining composite components in aerospace structures. Critical structures such as wing to fuselage joints, or flight control surface fittings use bolted joining techniques. Recent research concluded that higher bearing strengths in composite bolted joints can be achieved by a CFRP/ Titanium hybrid lay-up in the vicinity of the bolted joint. The high costs of titanium motivate a similar research with the more cost competitive austenitic steel. An experimental program was performed in order to compare the apparent inter-laminar shear stress (ILSS) of a CFRP reference beam with the ILSS of hybrid CFRP/Steel beams utilizing different surface treatments in the metallic ply. The apparent ILSS was determined by short beam test, a three-point bending test. Finite element models using cohesive elements in the CFRP/Steel interface were built to simulate the short beam test in the reference beam and in the highest interlaminar shear stress hybrid beam. The main parameters for a FEM simulation of inter laminar shear are the cohesive elements damage model and appropriate value for the critical energy release rate. The results show that hybrid CFRP/Steel have a maximum ILSS very similar to the ILSS of the reference beam. Hybrid CFRP/Steel is a competitive solution when compared with the reference beam ILSS. FEM models were able to predict the maximum ILSS in each type of beam

Integration of GMR sensors with different technologies

Less than thirty years after the giant magnetoresistance (GMR) effect was described, GMR sensors are the preferred choice in many applications demanding the measurement of low magnetic fields in small volumes. This rapid deployment from theoretical basis to market and state-of-the-art applications can be explained by the combination of excellent inherent properties with the feasibility of fabrication, allowing the real integration with many other standard technologies. In this paper, we present a review focusing on how this capability of integration has allowed the improvement of the inherent capabilities and, therefore, the range of application of GMR sensors. After briefly describing the phenomenological basis, we deal on the benefits of low temperature deposition techniques regarding the integration of GMR sensors with flexible (plastic) substrates and pre-processed CMOS chips. In this way, the limit of detection can be improved by means of bettering the sensitivity or reducing the noise. We also report on novel fields of application of GMR sensors by the recapitulation of a number of cases of success of their integration with different heterogeneous complementary elements. We finally describe three fully functional systems, two of them in the bio-technology world, as the proof of how the integrability has been instrumental in the meteoric development of GMR sensors and their applications.Peer ReviewedPostprint (published version

3D-nanostructured Au electrodes for the event-specific detection of MON810 transgenic maize

In the present work, the development of a genosensor for the event-specific detection of MON810 transgenic maize is proposed. Taking advantage of nanostructuration, a cost-effective three dimensional electrode was fabricated and a ternary monolayer containing a dithiol, a monothiol and the thiolated capture probe was optimized to minimize the unspecific signals. A sandwich format assay was selected as a way of precluding inefficient hybridization associated with stable secondary target structures. A comparison between the analytical performance of the Au nanostructured electrodes and commercially available screen-printed electrodes highlighted the superior performance of the nanostructured ones. Finally, the genosensor was effectively applied to detect the transgenic sequence in real samples, showing its potential for future quantitative analysis

Magnetic states of granular layered CoFe-Al\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e3\u3c/sub\u3e

The granular layered magnetic system Co80Fe20(t)/Al2 O3 (3 nm), where the Co80Fe20 layers of nominal thickness t form separate, almost spherical magnetic granules of typical diameter 2-3 nm between the Al2O3 spacers, was studied. We discuss measurements of the dc and ac magnetic susceptibility χ for 1 n

Magnetic field strength and orientation effects on co-fe discontinuous multilayers close to percolation

International audienceMagnetization and magnetoresistance in function of the magnitude and orientation of applied magnetic field were studied in Co-Fe discontinuous multilayers close to their structural percolation. The high pulsed magnetic fields up to 33 T were used in the 120–310 K temperature range. Comparison between longitudinal and transverse with respect to the film plane field configurations was made in the low-field and high-field regimes in order to clarify the nature of the measured negative magnetoresistance. Coexistence of two distinct magnetic fractions, superparamagnetic SPM, consisting of small spherical Co-Fe granules and superferromagnetic SFM, by bigger Co-Fe clusters, was established in this system. These fractions were shown to have different relevance for the system magnetization and magnetotransport. While the magnetization is almost completely up to 97% defined by the SFM contribution and practically independent of temperature in this range, the magnetoresistance experiences a crossover from a regime dominated by Langevin correlations suppressed with temperature between neighbor SPM and SFM moments at low fields, to that dominated by spin scattering enhanced with temperature of charge carriers within SFM clusters at high fields. Also, the demagnetizing effects, sensitive to the field orientation, were found to essentially define the low-field behavior and characteristic crossover field

Integration of magnetoresistive biochips on a CMOS circuit

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