Identification of beta-amyloid-binding sites on transthyretin

Transthyretin (TTR) binds to the Alzheimer-related peptide beta-amyloid (Aβ), and may protect against Aβ-induced neurotoxicity. In this work, the specific domains on TTR involved with binding to Aβ were probed. An array was constructed of peptides derived from overlapping sequences from TTR. Strong binding of Aβ to TIAALLSPYSYS (residues 106-117) was detected, corresponding to strand G on the inner β-sheet of TTR. Aβ bound weakly to four contiguous peptides spanning residues 59-83, which includes strand E through the E/F helix and loop. To further pinpoint specific residues on TTR involved with Aβ binding, nine alanine mutants were generated: I68A, I73A, K76A, L82A, I84A, S85A, L17A, T106A and L110A. Aβ binding was significantly inhibited only in L82A and L110A, indicating that Aβ binding to TTR is mediated through these bulky hydrophobic leucines. Aβ binding to L17A and S85A was significantly higher than to wild-type TTR. Enhancement of binding in L17A is postulated to arise from reduced steric restriction to the interior L110 site, since these two residues are adjacent in the native protein. The S85A mutation caused a reduction in TTR tetramer stability; increased Aβ binding is postulated to be a direct consequence of the reduced quaternary stability.     

Removal of ammonium ion from produced waters in petroleum offshore exploitation by a batch single-stage electrolytic process

This work describes a batch single-stage electrochemical process to remove quantitatively the ammonium ion from produced waters from petroleum exploration of the Campos' Basin, seeking to fulfil the directories of the National Brazilian Environmental Council. The anode was made out of titanium covered by a layer of RuO(2)+TiO(2) oxides (Dimensionally Stable Anode), whereas the cathode was made out of pure titanium. Anodic and cathodic compartments were separated by a membrane. The applied current varied from 0.3 to 1.5A. As the current increased NH(4)(+) removal was faster and pH was rapidly decreased to 3. The pH of the anodic compartment increased to approximately 10. When the current was 0.92 A chlorine evolution was observed after 40 min or only 15 min when that current was 1.50 A. In this voltage a deposit containing alkali-earth metal hydroxides/sulphates was formed on the membrane surface of the cathode side, thus suggesting a diffusion process from the anodic to the cathodic compartment. The maximum current applied to the cell must not exceed approximately 0.70 A in order to avoid chlorine evolution. Ammonia removal was over 99.9 wt% at 0.68 A in about 75 min.     

Albumin-Coated Single-Core Iron Oxide Nanoparticles for Enhanced Molecular Magnetic Imaging (MRI/MPI)

Colloidal stability of magnetic iron oxide nanoparticles (MNP) in physiological environments is crucial for their (bio)medical application. MNP are potential contrast agents for different imaging modalities such as magnetic resonance imaging (MRI) and magnetic particle imaging (MPI). Applied as a hybrid method (MRI/MPI), these are valuable tools for molecular imaging. Continuously synthesized and in-situ stabilized single-core MNP were further modified by albumin coating. Synthesizing and coating of MNP were carried out in aqueous media without using any organic solvent in a simple procedure. The additional steric stabilization with the biocompatible protein, namely bovine serum albumin (BSA), led to potential contrast agents suitable for multimodal (MRI/MPI) imaging. The colloidal stability of BSA-coated MNP was investigated in different sodium chloride concentrations (50 to 150 mM) in short- and long-term incubation (from two hours to one week) using physiochemical characterization techniques such as transmission electron microscopy (TEM) for core size and differential centrifugal sedimentation (DCS) for hydrodynamic size. Magnetic characterization such as magnetic particle spectroscopy (MPS) and nuclear magnetic resonance (NMR) measurements confirmed the successful surface modification as well as exceptional colloidal stability of the relatively large single-core MNP. For comparison, two commercially available MNP systems were investigated, MNP-clusters, the former liver contrast agent (Resovist), and single-core MNP (SHP-30) manufactured by thermal decomposition. The tailored core size, colloidal stability in a physiological environment, and magnetic performance of our MNP indicate their ability to be used as molecular magnetic contrast agents for MPI and MRI.     

Production of biodegradable rods of polycaprolactone/olanzapine for potential application in treatment of Schizophrenia

Olanzapine (OLZ) is a commonly antipsychotic used to treat schizophrenia, a mental illness, with fewer side effects when compared with other drugs of the same class. It is commercialized mainly as oral tablets and orally disintegrating tablets. However, this drug oral bioavailability is affected by the first pass effect and low solubility in water. This requires high daily doses that can cause more side effects and poor treatment compliance. Also, the frequency of frequency of tablet intake is commonly related to patients' abandonment of schizophrenia treatment. So, the development of implantable biomaterials for OLZ delivery can be an alternative to solve both problems, since this material can, potentially, be used subcutaneously in less frequent administrations, thus the treatment has a greater chance of success. Therefore, the objective of this work was to produce polycaprolactone (PCL) rods incorporated with OLZ by hot-melt extrusion technique. The rods were characterized by different techniques, which showed an amount of 6.78 ± 0.56 mg of OLZ per rod. The in vitro release studies were performed and they showed a controlled release of the drug that followed the Higuchi's model. These results indicated that the PCL/OLZ rods have potential application in the schizophrenia treatment.     

Evaluation of Pd-TiO2/ZSM-5 catalysts composition effects on hydrogen production by photocatalytic water splitting

The photocatalyst composition can significantly affect their physicochemical properties that are directly related to their photocatalytic activity. In this work, the influence of the Pd-TiO₂/ZSM-5 catalyst composition on hydrogen production by photocatalytic water splitting was studied. The ZSM-5 zeolite was use as support for the active phase of titanium dioxide; palladium was also incorporated as a metallic co-catalyst. The concentrations of TiO₂ and Pd were varied during catalyst synthesis according to a factorial rotational experimental design. The catalysts were characterized and employed in hydrogen production under ultraviolet radiation. Empirical models were obtained for relating physicochemical properties and hydrogen production as functions of palladium and titanium dioxide content. Relative crystallinity of the support and specific surface area were affected only by the titanium dioxide contend while band gap energy and hydrogen production were affected by nominal percentage of metallic co-catalyst and active phase. The most active catalyst was the 1.5%Pd-28%TiO₂/ZSM-5, which promoted hydrogen production rate of 1148 μmol g_cat^?1 h^?1 under low power irradiation font.     

Organic solid waste originating from the meat processing industry as an alternative energy source

The biosolids originating from the wastewater treatment process of two meat processing plants (LFP and LFG) were characterized as a fuel and their potential for utilization as alternative energy sources was assessed through the combustion of LFP in a pilot scale cyclone combustor. A comparative evaluation of the LFP, LFG and SD (sawdust) properties as well as the emissions during the combustion test was performed. The high energy content of LFP (LHV (lower heating value) equal to 25.77 MJ kg⁻¹) and LFG (LHV = 25.89 MJ kg⁻¹), both dry and ash free (daf), combined with the high volatile matter content (85.29 and 85.61 wt%, daf, respectively) improve the ignition and burning of the solids. Also, the fouling and slagging tendencies of the ashes were predicted based on the fuel ash composition and ash fusibility correlations. The emissions of CO, SO₂, and NO_x and total organic carbon (TOC) were compared to guideline limits established by Brazilian and international legislation. The TOC concentrations were below the emission limits. The high level of nitrogen in LFP (9.24 wt%, daf) led to high levels of NO_x. In this regard, further combustion tests are being performed by the authors.     

Investigation on the Geometric Imperfections driven Local Buckling Onset in Composite Conical Shells

Buckling is a critical failure phenomenon for structures, and represents a threat for thin shells subjected to compressive forces. The global buckling load, for a conical structure, depends on the geometry and material properties of the shell, on the stacking sequence, on the type of applied load and on the initial geometric imperfections. Geometric imperfections, occurring inevitably during manufacturing and assembly of thin-walled composite structures, produce a reduction in the carrying load capability with respect to the design value. This is the reason why investigating these defects is of major concern in order to avoid over-conservative design structures. In this paper, the buckling behavior a conical structure with 45° semi-vertical angle is numerically investigated. The initial imperfections are taken into account by using different strategies. At first, the Single Perturbation Load Approach (SPLA), which accounts for defects in the form of a lateral load, normal to the surface, has been adopted. Then, the actual measured defects have been applied to the structure by using the Real Measured Mid-Surface Imperfections (MSI) approach. Investigations on cylindrical shells using the first strategy have already shown the occurrence of a particular phenomenon called “local snap-through”, which represents a preliminary loss of stiffness. In order to better understand this phenomenon for conical shells, both the aforementioned techniques have been used to provide an exhaustive overview of the imperfections sensitiveness in conical composite shells. This study is related to part of the work performed in the frame of the European Union (EU) project DESICOS.     

凭吊查尔斯顿市

查尔斯顿市位于波士顿都市区,曾经是18世纪美国工业革命的摇篮之一,也是新移民与蓝领劳动的家园.如今,查尔斯顿正在转为创意产业的新管理者的地盘.跟随运输轨道就会发现工业区变迁的痕迹,而且这些废墟的空间恰好是中产阶级改造的对象.Regina Schroeder以马萨诸塞州查尔斯顿市已废弃的运输轨道为主题,通过一组略带思古幽情的照片提醒我们:城市更新要么是将历史消灭,要么是以历史作为发展元素.这样不只是厂房关闭,同时也是一代人生的失踪.