Removal of Pesticides by a Combined Ozonation/Attached Biomass Process Sequence

Different combinations of ozonation and biological treatments were tested on an industrial effluent containing high pesticide concentrations. Ozonation was performed in 450 L columns at 1.5 h HRT each. Biological treatment was carried out in a submerged filter (BIOFOR). Ozone was effective in removing herbicides but dosages up to 1000 mg L^?1 were needed. The improved biodegradability of the organic compounds after pre-ozonation was demonstrated by Oxygen Uptake Rates (OUR) tests and by the efficiency of biological treatment towards COD, and pesticides. The Italian discharge limit of 50 ppb total pesticides was achieved by combining pre-ozonation, biological treatment, and post- ozonation.     

Editorial

In this study the Taguchi method is used to find the optimal process parameters for aluminium foam manufacturing. Porous metals are the unique materials used for light weight structural components, for filters and electrodes and for shock or sound absorbing products. Recently, interesting foaming technology developments have proposed metallic foams as a valid commercial chance. Metallic foam manufacturing techniques include solid state powder methods, gas blowing processes, metal deposition onto a polymer precursor and liquid state processing. The aluminium foams presented in this study are produced by the powder metallurgy route starting from aluminium powders with titanium hydride as the foaming agent. During the experimental work, many samples are made by utilizing the combination of process parameters based on Taguchi orthogonal design. Three manufacturing parameters are studied: the silicon carbide content in powder mixture, the compaction pressure and the foaming temperature. The Taguchi method is applied to design an orthogonal experimental array and a multi-objective optimization approach is then proposed by simultaneously minimizing the relative density and maximizing the absorbed energy. Verification test is also performed to prove the effectiveness of the presented technique.     

Shadow Epitaxy for In Situ Growth of Generic Semiconductor/Superconductor Hybrids

Uniform, defect-free crystal interfaces and surfaces are crucial ingredients for realizing high-performance nanoscale devices. A pertinent example is that advances in gate-tunable and topological superconductivity using semiconductor/superconductor electronic devices are currently built on the hard proximity-induced superconducting gap obtained from epitaxial indium arsenide/aluminum heterostructures. Fabrication of devices requires selective etch processes; these exist only for InAs/Al hybrids, precluding the use of other, potentially superior material combinations. This work introduces a crystal growth platform—based on 3D structuring of growth substrates—which enables synthesis of semiconductor nanowire hybrids with in situ patterned superconductor shells. The platform eliminates the need for etching, thereby enabling full freedom in the choice of hybrid constituents. All of the most frequently used superconducting hybrid device architectures are realized and characterized. These devices exhibit increased yield and electrostatic stability compared to etched devices, and evidence of ballistic superconductivity is observed. In addition to aluminum, hybrid structures based on tantalum, niobium, and vanadium are presented.     

Analysis of a second-order sliding-mode algorithm in presence of input delays

In this note, a double integrator system under the action of a second-order sliding-mode control algorithm is considered, and the resulting closed-loop behavior in presence of an input delay is analysed. Due to the delay, in the limit the system trajectories are periodic. Whenever the control modulus is chosen to be constant, the amplitude and period of the resulting oscillations are fixed for any initial value. If the control behaves asymmetrically, it is shown that this is no more true, since the overall dynamical system can admit diverse limit cycles.     

Abnormal cytoskeletal protein expression in cultured skin fibroblasts from type 1 diabetes mellitus patients with nephropathy: A proteomic approach

Diabetic nephropathy (DN) develops in about 40% of insulin-dependent type 1 diabetes mellitus (T1DM) patients, and is associated not only with diabetes duration and metabolic control, but also with a genetic predisposition. Constitutive alterations of cytoskeletal proteins may play a role in the development of DN. We investigated the expression of these proteins in cultured skin fibroblasts, obtained from long-term T1DM patients with and without DN but comparable metabolic control, and from matched healthy subjects, by means of 2-DE electrophoresis and MS-MALDI analyses. In T1DM with DN, compared to the other two groups, quantitative analyses revealed an altered expression of 17 spots (p<0.05-p<0.01), corresponding to 12 unique proteins. In T1DM with DN, beta-actin and three isoforms of tubulin beta-2 chain, tropomodulin-3, and LASP-1 were decreased, whereas two tubulin beta-4 chain isoforms, one alpha actinin-4 isoform, membrane-organizing extension spike protein (MOESIN), FLJ00279 (corresponding to a fragment of myosin heavy chain, non-muscle type A), vinculin, a tropomyosin isoform, and the macrophage capping protein were increased. A shift in caldesmon isoforms was also detected. These results demonstrate an association between DN and the constitutive expression of cytoskeleton proteins in cultured skin fibroblasts from T1DM with DN, which may retain pathophysiologycal implications.     

Post-transplant proteinuria associated with everolimus: Definition of main features with proteomics

Little is known on both the composition and mechanism(s) of proteinuria associated with the use of mTOR inhibitors, in particular of Everolimus (E). We characterized urinary proteins utilizing an integrated proteomics approach (quantitative essays, 2‐DE, MALDI‐TOF, Western blot) in 48 renal transplant recipients who were alternatively treated with E (n = 31) or with enteric coated mycophenolic acid (EC‐MPA) (n = 17). Twelve E patients (39%) developed high (>3 g/day) or intermediate proteinuria (1–3 g) compared to four (23%) of the EC‐MPA group. Urinary proteins (p<0.001), β2 microglobulin (p<0.001) and α1microglobulin (p<0.025) were higher in E than in EC‐MPA, appeared more rapidly and were inversely correlated with the day of treatment. Proteomics showed a marked increase of all urinary components in E and EC‐MPA patients, major changes involving typical components of glomerular damage (albumin, α1‐Zn glycoprotein, α2HS glycoprotein, leucin‐richα2‐glycoprotein) and specific bio‐markers for E (clusters of α1‐antitrypsin fragments and monoclonal λ chains). Finally, inter‐α‐trypsin‐inhibitor heavy chain H4 precursor was decreased in E and EC‐MPA urine compared to normal urine. In conclusion, E induced massive and generalized proteinuria of mixed glomerular and tubular origin that was correlated with the start of treatment and reached a nephrotic range in few cases. Specific urinary markers reflect renal alterations related to the transplant or specific alterations associated with the drug.     

Proteins and protein fragments in nephrotic syndrome: Clusters, specificity and mechanisms

Proteinuria is the hallmark of renal diseases and the characterization of the urinary protein composition may become an important source of information for diagnosis and research. So far, protein analysis in urine has been utilized for a generic individuation of site-specific defects (glomerular vs. tubular) but there is a need for an extension of proteomics to specific urinary biomarkers in selected clinical conditions. The identification of fragments of proteins in plasma and urine may increase the spectrum of urinary biomarkers. The unique speculative application so far proposed for protein fragments is nephrotic syndrome, and specifically focal segmental glomerulosclerosis, in which case they reflect intrinsic proteolysis occurring in plasma and represent surrogate biomarkers of the disease activity. Albumin is probably the most studied protein. Several of the albumin fragments present a peculiar distribution of the fingerprint peptide pattern containing both the N-terminal region and the C-terminal domain with a complete lack of any MS signals for the internal sequence region. Their characterization utilizing new strategies based on 2-D nondenaturing electrophoresis is now in progress. Studies on a direct characterization of proteases in plasma and urine will also define the participation of proteases to the genesis of renal diseases.     

Inhibitive determination of metal ions by an amperometric glucose oxidase biosensor: Study of the effect of hydrogen peroxide decomposition

An amperometric glucose biosensor based on glucose oxidase immobilized in electrosynthesized poly-o-phenylenediamine was successfully applied to the determination of a wide group of heavy metals of environmental interest. The inhibition effects of Hg²⁺, Ag⁺, Cu²⁺, Cd²⁺, Pb²⁺, Cr³⁺, Fe³⁺, Co²⁺, Ni²⁺, Zn²⁺, Mn²⁺ and also CrO₄²⁻ on glucose oxidase were studied. Collected data showed a reversible inhibition mechanism. Results about the quantitative analysis of metal ions in terms of detection limit, linear range, sensitivity and R.S.D. are discussed for each tested metal ion. The biosensor was able to discriminate two different oxidation states of chromium being able to reject Cr³⁺ and to detect the toxic species CrO₄²⁻. Also biosensor storage stability and response reproducibility were investigated.

Moreover, this study represents the first attempt of evaluating the effect of the hydrogen peroxide decomposition by metal ions on the response of an enzymatic biosensor based on the amperometric detection of the hydrogen peroxide. Experiments were performed with the aim to quantitatively evaluate, for any single metal ion, if this process is competitive with the inhibition of enzymatic reaction in the adopted experimental conditions.     

Oxidation efficiency in the electro-Fenton process

An electro-Fenton treatment of a solution containing phosphorus compounds using a graphite electrode is described. Different operating conditions are tested to investigate the influence of the reagent ratio on the oxidative efficiency. Results show that electro-Fentons reagent is able to provide a powerful conversion of the phosphorous compounds into phosphate. As hydrogen peroxide is continuously provided by the cathodic reduction of oxygen, the crucial step appears to be the iron dosage whose optimal concentration is found in the range 50–150 mg l^–1. Quantitative oxidation is not reached for concentration lower than 50 mg l^–1. Nonetheless, an excess of both iron and hydrogen peroxide in the bulk is found to negatively affect the oxidation yield because of the occurrence of undesired side reactions.