Modeling Parkinson’s Disease Neuropathology and Symptoms by Intranigral Inoculation of Preformed Human α-Synuclein Oligomers

The accumulation of aggregated α-synuclein (αSyn) is a hallmark of Parkinson’s disease (PD). Current evidence indicates that small soluble αSyn oligomers (αSynOs) are the most toxic species among the forms of αSyn aggregates, and that size and topological structural properties are crucial factors for αSynOs-mediated toxicity, involving the interaction with either neurons or glial cells. We previously characterized a human αSynO (H-αSynO) with specific structural properties promoting toxicity against neuronal membranes. Here, we tested the neurotoxic potential of these H-αSynOs in vivo, in relation to the neuropathological and symptomatic features of PD. The H-αSynOs were unilaterally infused into the rat substantia nigra pars compacta (SNpc). Phosphorylated αSyn (p129-αSyn), reactive microglia, and cytokine levels were measured at progressive time points. Additionally, a phagocytosis assay in vitro was performed after microglia pre-exposure to αsynOs. Dopaminergic loss, motor, and cognitive performances were assessed. H-αSynOs triggered p129-αSyn deposition in SNpc neurons and microglia and spread to the striatum. Early and persistent neuroinflammatory responses were induced in the SNpc. In vitro, H-αSynOs inhibited the phagocytic function of microglia. H-αsynOs-infused rats displayed early mitochondrial loss and abnormalities in SNpc neurons, followed by a gradual nigrostriatal dopaminergic loss, associated with motor and cognitive impairment. The intracerebral inoculation of structurally characterized H-αSynOs provides a model of progressive PD neuropathology in rats, which will be helpful for testing neuroprotective therapies.     

Increased hydrogen photoproduction by means of a sulfur-deprived Chlamydomonas reinhardtii D1 protein mutant

The photoproduction of H₂ was studied in a sulfur-deprived Chlamydomonas reinhardtii D1 mutant that carried a double amino acid substitution. The leucine residue L159 was replaced by isoleucine, and the asparagine N230 was replaced by tyrosine (L159I-N230Y). Phenotypic characterization of the mutant showed some interesting features compared to its wild type, namely: (1) a lower chlorophyll content; (2) a higher photosynthetic capacity and higher relative quantum yield of photosynthesis; (3) a higher respiration rate; (4) a very high conversion of violaxanthin to zeaxanthin during H₂ production; (5) a prolonged period of H₂ production. In standard conditions, the mutant produced more than 500 ml of H₂, that is, more than one order of magnitude greater than its wild type, and about 5-times greater than the CC124 strain that was used for comparison. The better performance of the mutant was mainly the result of a longer production period. Biogas produced contained up to 99.5% H₂.     

Dielectric response of polymer relaxors

Dielectric response of vinylidene fluoride type ferroelectric polymers is dominated by that of segmental motions in the amorphous phase in temperature range 200–300 K and contributions related to the local mode and ferroelectric–paraelectric transition in the crystalline phase of the polymer at higher temperatures. Diffuse and frequency-dependent dielectric anomaly observed in fast electron irradiated polyvinylidene fluoride-trifluoroethylene P(VDF/TrFE) has been related to relaxor-like behavior induced in the semicrystalline ferroelectric copolymers. As random field and the response of polar nanosize clusters determine the relaxor behavior the effects of disorder and fast electron irradiation (below and above T _C) on the three contributions to the dielectric response of PVDF, P(VDF/TrFE)(75/25) and P(VDF/TrFE)(50/50) are shown. The processes involved in radiation-induced functionalization of PVDF-type polymers are discussed on the basis of results of ESR, IR and Raman spectroscopy studies.     

Synthesis and characterisation of β-TCP/bioglass/zirconia scaffolds

Tricalcium phosphate scaffolds reinforced with bioglass were characterised morphologically, physically, and mechanically. The scaffolds were fabricated through powder technology and the polymer foaming technique using 80?wt-% of β-TCP and 20?wt-% of phosphate-based bioglass doped with zirconia in various amounts (0, 0.25, 0.5, 0.75, and 1.0?wt-%). The foaming agent was varied (1, 1.5, 2, 2.5, and 3?wt-%) to determine the optimal amount that ensured an interconnected porosity and pore size suitable for increasing osteoconduction and cell attachment. Promising samples for tissue engineering applications showed a pore size ranging from 1.41 to 303?μm, total porosity of 50–53%, compressive strength values between 0.6 and 1?MPa, Young’s modulus from 357 to 574?MPa, and excellent interconnectivity.     

Seawater fatty acids and lipid classes in an urban and a rural Nova Scotia inlet

Seawater samples collected in the summer of 1989 in Nova Scotia inlets were analyzed for lipid content to examine water quality. One inlet, the Northwest Arm, is located adjacent to an urban center, while the other, Ship Harbour, is located in an uninhabited area and contains three commercial mollusk farms. Lipids in the dissolved and particulate fractions were measured by Chromarod-Iatroscan thin-layer chromatography with flame ionization detection and by gas chromatography. Samples collected near the urban center had higher levels of particulate hydrocarbons (28±15 μg/L) than those collected in the relatively pristine environment (11±1 μg/L). The urban center samples also had higher levels of particulate free aliphatic alcohols (14±5vs. 8±1 μg/L) and free fatty acids (5±1vs.<0.5 μg/L), suggesting degradation of wax esters and other fatty acid esters. Dissolved and particulate matter fatty acids contained a higher proportion of monounsaturated acids near the urban center (33–35vs. 25–29% of the total fatty acids). The essential fatty acids 20∶5n−3 (eicosapentaenoic acid) and 22∶6n−3 (docosahexaenoic acid), presumably of algal origin, were more prominent in the pristine environment (up to 3.5%), where mollusk aquaculture is practiced. Fatty acid markers of toxic algae were virtually absent (<0.2%) in samples taken from both locations. O.S.C. contribution 173.     

Determination of humic acids content in composts by means of near- and mid-infrared spectroscopy and partial least squares regression models

Humic acids are part of the stable organic matter fraction in soils and composts. Due to their favorable properties for soils and plants, and their role in carbon sequestration, they are considered a quality criterion of composts. Time-consuming chemical extraction of humic acids and the inherent source of errors require alternative approaches for humic acids quantification. Different measurement techniques in the mid-infrared (MIR: KBr pellet technique) and near-infrared (NIR: fiber probe as well as an integrating sphere with a sample rotator) regions were applied. Partial least squares regression (PLSR) models based on infrared spectra were developed to determine humic acids contents in composts. As the wavenumber regions used (NIR: 6105-5380 cm(-1) and 4360-4220 cm(-1), MIR: 1745-1685 cm(-1) and 1610-1567 cm(-1)) represent different molecular vibrations, the importance of the methylene-group-derived vibrations for the NIR models is discussed. The correlation coefficients obtained for the KBr pellet technique, the NIR fiber probe technique, and the NIR integrating sphere (r = 0.94, 0.93, and 0.94) and the root mean square errors of cross-validation (RMSECV = 2.2% organic dry matter (ODM), 2.5% ODM, and 2.2% ODM) make the models appropriate for application in composting practice.     

Preparation of CEL2 glass-ceramic porous scaffolds coated with chitosan microspheres that have a drug delivery function

The present work focused on the preparation of CEL2 bioactive glass (SiO₂–P₂O₅–CaO–MgO–K₂O–Na₂O) scaffolds loaded with chitosan microspheres. Chitosan microspheres, with a mean particle size of 0.55 μm ± 0.25 μm and loaded with acetaminophen, were obtained through the water-in-oil single emulsion solvent evaporation method and were adhered to the surface of the scaffolds by a simple dip-coating technique. The characterization of the microsphere-loaded scaffolds, before and after immersion in simulated body fluid (SBF), was performed by scanning electron microscopy, X-ray diffraction, and infrared spectroscopy. In vitro bioactivity was performed for 21 days. The glass-ceramic microsphere-loaded scaffolds showed more than 70% interconnected porosity and an average compressive strength of 1.2 ± 0.43 MPa after immersion in SBF. They also showed the formation of a hydroxyapatite layer from the first day of immersion in SBF, demonstrating their high bioactivity. The microspheres were shown to be homogeneously dispersed on the scaffold surfaces. After 120 hours, the biologic tests showed good fibroblast cell proliferation onto the scaffolds. The encapsulated drug in the microspheres was released by diffusion in a sustained manner (90% and 99% in 200 hours). The results suggest that scaffolds have a promising role in applications of bone tissue engineering.     

Development of Mechanically Biologically Treated Municipal Solid Waste under Different Vegetation Types

The use of mechanically biologically treated (MBT) waste as cover material for landfills during the aftercare period has gained in importance since the previous decade. The question arises how such materials change their properties under open field conditions. For field experiments, two MBT plants in Austria with related landfills were selected. A cover layer consisting of MBT material was applied on the surface and planted with grass and rape. The development without any vegetation served as a reference. Leaching, mineralization, and humification of waste organic matter were quantified. The impact of time, sampling depth, respective oxygen supply, and vegetation on the material was investigated. Intensive grass vegetation promoted mineralization and humification. Leaching of salts and the transformation of nitrogen were mainly influenced by time and depth. Aerobic conditions advanced degradation of still-reactive material. Under aerobic conditions, the remaining respiration activity was about two times lower than in the anaerobic zones. It was proven that well stabilized MBT material can be used as a cover layer with adequate vegetation.     

探索常见房屋装修设计方案

随着时代的发展和科技的进步,人们在满足基本的物质文化需求的基础上开始更加注重精神上的需求。本文对房屋装修设计的要点和趋势、房屋装修过程中面临的问题以及解决问题的对策等做了详细的分析和系统的阐述。