Time course and progression of wild type α-Synuclein accumulation in a transgenic mouse model

Background

Progressive accumulation of α-synuclein (α-Syn) protein in different brain regions is a hallmark of synucleinopathic diseases, such as Parkinson’s disease, dementia with Lewy bodies and multiple system atrophy. α-Syn transgenic mouse models have been developed to investigate the effects of α-Syn accumulation on behavioral deficits and neuropathology. However, the onset and progression of pathology in α-Syn transgenic mice have not been fully characterized. For this purpose we investigated the time course of behavioral deficits and neuropathology in PDGF-β human wild type α-Syn transgenic mice (D-Line) between 3 and 12 months of age.

Results

These mice showed progressive impairment of motor coordination of the limbs that resulted in significant differences compared to non-transgenic littermates at 9 and 12 months of age. Biochemical and immunohistological analyses revealed constantly increasing levels of human α-Syn in different brain areas. Human α-Syn was expressed particularly in somata and neurites of a subset of neocortical and limbic system neurons. Most of these neurons showed immunoreactivity for phosphorylated human α-Syn confined to nuclei and perinuclear cytoplasm. Analyses of the phenotype of α-Syn expressing cells revealed strong expression in dopaminergic olfactory bulb neurons, subsets of GABAergic interneurons and glutamatergic principal cells throughout the telencephalon. We also found human α-Syn expression in immature neurons of both the ventricular zone and the rostral migratory stream, but not in the dentate gyrus.

Conclusion

The present study demonstrates that the PDGF-β α-Syn transgenic mouse model presents with early and progressive accumulation of human α-Syn that is accompanied by motor deficits. This information is essential for the design of therapeutical studies of synucleinopathies.     

In situ reactive compatibilization of polypropylene/epoxidized natural rubber blends by electron induced reactive processing: novel in‐line mixing technology

Blends of polypropylene (PP) and epoxidized natural rubber (ENR) were prepared by an in‐line electron induced reactive processing technique. The mixing was done in a Brabender mixing chamber coupled with an electron accelerator. The effect of sequence of electron treatment on the compatibilization of non‐polar PP and polar ENR was investigated in the presence of triallyl cyanurate (TAC). Finally, the resulting blends were characterized by different techniques, namely, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), dynamic mechanical analysis (DMA), differential scanning calorimetry (DSC), tensile tests, and rheological studies. Generation of phase coupling and chemical compatibilization were observed from FTIR analysis. DMA studies showed enhanced high‐temperature modulus (above the glass transition temperature of both components) followed up by lowering in the tan δ peak. Rheological studies showed increase in modulus at low frequencies. Electron treatment and incorporation of rubber phase into PP showed significant effect on the degree of crystallinity of the blends, which was characterized by DSC study. The results obtained from FTIR, DMA, SEM, rheological studies, and tensile tests strongly affirmed that electron induced reactive processing of PP in presence of TAC before adding of ENR performed the best amongst all samples modified with electrons investigated in this study. Copyright © 2010 John Wiley & Sons, Ltd.     

Spectroscopic Characterization of a Steam Arc Cutting Torch

Optical emission spectroscopy has been used to investigate the characteristics of a plasma jet produced by a steam arc cutting torch operated in air at atmospheric pressure. A procedure has been developed for simultaneous determination of temperature and pressure in the plasma jet as well as an effective nonequilibrium factor. It is based on comparison of a few experimental and simulated spectral quantities. The experimental data were obtained from the spectrum of H_β and OII lines centred at 480 nm. The existence of the shock wave structure characteristic of an underexpanded jet can clearly be deduced from the measured properties. In the first expansion region, the centreline pressure drops from about 1.4 atm at the nozzle exit to about 0.7 atm a few tenths of millimeter downstream. On the contrary, the centreline temperature remains almost unchanged within this region and reaches the value of about 23,000 K.     

Mutual diffusion in binary mixtures of ionic liquids and molecular liquids by dynamic light scattering (DLS)

The present study shows that dynamic light scattering (DLS) is capable of measuring mutual diffusion coefficients for binary mixtures of ionic liquids (ILs) with different molecular liquids over the complete composition range. Evidence is given that the light scattering signals are related to true molecular binary diffusion. The method stands out due to its ability to work non-invasively in macroscopic thermodynamic equilibrium with reasonable accuracy and within convenient measurement periods. Compared with other techniques, mixtures with distinctly higher viscosities can be probed. For exemplary binary mixtures of 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO(4)]) with acetone, acetonitrile, dichloromethane, ethanol, or water as well as of 1-ethyl-3-methylimidazolium methanesulfonate ([EMIM][MeSO(3)]) with acetone, water, or methanol, mutual diffusivity data were measured over a wide range of composition at a temperature of 293.15 K. In general, the mutual diffusivity increases with increasing mole fraction of the molecular liquid and similarities to aqueous solutions of classical inorganic salts can be found. The characteristic behavior of the mutual diffusion coefficients is influenced by the nature of the chosen molecular liquid. For IL water mixtures, low light scattering intensities were observed despite the large refractive index difference of the pure components. The reason for this behavior may be the existence of water clusters in the mixtures. Additional measurements for IL acetone mixtures at temperatures ranging from 278.15 K to 323.15 K showed that the temperature dependence of the mutual diffusivity can be represented by Arrhenius functions and is increasing for decreasing mole fractions of acetone.     

Facile synthesis of Ag@Pd satellites-Fe3O4 core nanocomposites as efficient and reusable hydrogenation catalysts

Well-dispersed Ag@Pd supported on magnetite nanoparticles have been obtained through a simple colloidal impregnation method. The as-synthesised nanocomposite exhibits greatly enhanced catalytic reactivity and reusability towards 4-nitrophenol hydrogenation.     

Synthesis,characterization, and antibacterial activities of copper(I) bromide complexes of thioureas: X-ray structure of [Cu(Metu)<Subscript>4</Subscript>]Br

Copper(I) complexes of thioureas having the general formulae [CuL_nBr] and [CuL_n]Br [where, n = 1 − 4 and L = thiourea (Tu), N-methylthiourea (Metu), N-ethylthiourea (Ettu), N,N^′-dipropylthiourea (Dprtu), N,N^′-dibutylthiourea (Dbtu) or N,N^′-diphenylthiourea (Dphtu)] were prepared and characterized by elemental analysis, IR, and NMR (¹H and ¹³C) spectroscopy. The crystal structure of one of them, [Cu(Metu)₄]Br (1), was determined by X-ray crystallography. The X-ray structure of 1 describes a tetrahedral geometry around copper(I) with all Metu ligands binding through sulfur atoms. An upfield shift in the ¹³C NMR and downfield shift in the ¹H NMR spectra are consistent with the thione coordination to copper(I). Antimicrobial activities of the complexes were evaluated by the minimum inhibitory concentration method. The results showed that only [Cu(Ettu)₃Br] was effective in inhibiting the growth of all the tested organisms (gram-positive, gram-negative bacteria, and Candida sp.), while the other complexes were not effective against all the organisms.     

Effort on calibration of infrared spark ablation of copper with synthetic copper standards

Two types of copper samples, compact certified copper reference materials and calibration samples prepared from liquid doped, pressed copper powders, were studied in terms of accuracy of obtained calibration functions originating from infrared spark ablation. Additionally, corresponding particle size distributions of the aerosols from infrared spark ablation were recorded. It is shown that the differences in quantification results, originating from the two sets of calibration functions, could not mainly be ascribed to different particle size distributions of the two copper sample types. Possible other causes, as different ablation rates, parts of melting and differences of the chemical constitutions of the two sample types were explored.     

Analysis and design of photobioreactors for microalgae production II: experimental validation of a radiation field simulator based on a Monte Carlo algorithm

In a previous study, we developed a methodology to assess the intrinsic optical properties governing the radiation field in algae suspensions. With these properties at our disposal, a Monte Carlo simulation program is developed and used in this study as a predictive autonomous program applied to the simulation of experiments that reproduce the common illumination conditions that are found in processes of large scale production of microalgae, especially when using open ponds such as raceway ponds. The simulation module is validated by comparing the results of experimental measurements made on artificially illuminated algal suspension with those predicted by the Monte Carlo program. This experiment deals with a situation that resembles that of an open pond or that of a raceway pond, except for the fact that for convenience, the experimental arrangement appears as if those reactors were turned upside down. It serves the purpose of assessing to what extent the scattering phenomena are important for the prediction of the spatial distribution of the radiant energy density. The simulation module developed can be applied to compute the local energy density inside photobioreactors with the goal to optimize its design and their operating conditions.