aHUS caused by complement dysregulation: new therapies on the horizon

Atypical hemolytic uremic syndrome (aHUS) is a heterogeneous disease that is caused by defective complement regulation in over 50% of cases. Mutations have been identified in genes encoding both complement regulators [complement factor H (CFH), complement factor I (CFI), complement factor H-related proteins (CFHR), and membrane cofactor protein (MCP)], as well as complement activators [complement factor B (CFB) and C3]. More recently, mutations have also been identified in thrombomodulin (THBD), an anticoagulant glycoprotein that plays a role in the inactivation of C3a and C5a. Inhibitory autoantibodies to CFH account for an additional 5–10% of cases and can occur in isolation or in association with mutations in CFH, CFI, CFHR 1, 3, 4, and MCP. Plasma therapies are considered the mainstay of therapy in aHUS secondary to defective complement regulation and may be administered as plasma infusions or plasma exchange. However, in certain cases, despite initiation of plasma therapy, renal function continues to deteriorate with progression to end-stage renal disease and renal transplantation. Recently, eculizumab, a humanized monoclonal antibody against C5, has been described as an effective therapeutic strategy in the management of refractory aHUS that has failed to respond to plasma therapy. Clinical trials are now underway to further evaluate the efficacy of eculizumab in the management of both plasma-sensitive and plasma-resistant aHUS

Novel process for the production of 3Y-TZP ceramics: comparison between ageing in artificial saliva and accelerated ageing

The degradation of tetragonal zirconia polycrystalline (3Y-TZP) ceramics prepared by a novel film growth technique, and by sintering at 1400 °C, was evaluated for one year using two processes: (i) degradation under oral conditions in artificial saliva (37 °C and pH 6.8) and (ii) accelerated degradation by autoclaving at 134 °C at 0.2 MPa of pressure. X-ray diffraction analysis of 3Y-TZP ceramics sintered at 1400 °C showed a phase transformation (tetragonal to monoclinic) in 3Y-TZP ceramics after the fifth month in artificial saliva. After 12 months in artificial saliva, there was ∼11% of monoclinic phase present in 3Y-TZP ceramics, but only ∼2% of monoclinic phase in samples that were subjected to accelerated degradation for 5 h. No correlation was found between the level of ageing during accelerated degradation and degradation in artificial saliva. There was no degradation of 3Y-TZP ceramics prepared by a novel film growth technique, independently of the degradation method used, which suggests that this material could be used for dental prosthetics

Iron influence on uranium removal from water using cellulose acetate membranes doped with activated carbon

International audienceUltrafiltration removal of uranium from water was investigated using cellulose triacetate-activated carbon (CTA-AC) composite membranes. Two different approaches were adopted: (i) adding iron chloride to the uranyl solution (FeCl3 at 0.5, 1.0, and 2.0ppm), and (ii) filtration of pure uranyl nitrate throughout composite membranes made of CTA filled with AC doped with iron. The solution to be filtrated was mixed with uranyl nitrate dissolutions at very low concentration (1.2ppm), with pH 6-8. AC was added to CTA using a casting film process to obtain dense membranes. Average uranium removal was 22 +/- 3%. The presence of iron in the membrane, either dissolved or incorporated into the activated carbon, contributed to uranium filtration, allowing reaching up to 50% removal efficiency (RE). The lowest RE value (4%) was obtained using a membrane prepared with AC oxidized with nitric acid (3HNO-AC) which does not present a significant amount of iron. Another parameter driving uranium transport is the pH, as uranium forms high molecular weight compounds in alkaline solutions, and therefore remains trapped into membrane structure. This explains the RE value of 21%, using 3HNO-AC membrane at high pH. AC dispersion also plays an important role during uranium transport. If it is well dispersed into the polymeric matrix, high RE is attained due to the high surface area available into the material. On the contrary, if AC agglomerates, uranium can go throughout the membrane, thereby increasing its permeability

What is the Effect of Critical Surface Tension of PbSO3 Thin Film?

This study focuses on the critical surface tension of lead sulfite (PbSO3) crystalline thin film produced with chemical bath deposition on substrates (commercial glass).The PbSO3 thin films were deposited at room temperature at different deposition times. The structural properties of the films were defined and examined according to X-ray diffraction (XRD) and the XRD results such as dislocation density, average grain size, and no. of crystallites per unit area. Atomic force microscopy was used to measure the film thickness and the surface properties. The critical surface tension of the PbSO3 thin films was measured with an optical tensiometer instrument and calculated using the Zisman method. The results indicated that the critical surface tension of films changed in accordance with the average grain size and film thickness. The film thickness increased with deposition time and was inversely correlated with surface tension. The average grain size increased according to deposition time and was inversely correlated with surface tension

Do the Naica giant crystals deteriorate due to human sction?

Resumen del trabajo presentado al 25th international Congress on X-ray optic and microanalysis (ICXOM), celebrado en EE.UU. del 5 al 9 de agosto de 2019.The support given by CONACYT Project No. 183706 and by SSRL, ELETTRA, ESRF synchrotron facilities is acknowledged. Authors are thankful to Cia. Peñoles and Naica Mine for providing samples