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The dysfunction of cholinergic neurons is a typical hallmark in Alzheimer's disease (AD). In animal models of AD, fragments of amyloid beta protein (Aβ) and Tau protein are thought to interfere with central cholinergic transmission, specifically with synthesis and release of acetylcholine. Thus, we aimed to investigate whether the cerebrospinal fluid (CSF) levels of Aβ42 and Tau proteins in AD patients could influence physiological central cholinergic activity. In AD patients (n = 19), central cholinergic function was evaluated in vivo by using short afferent latency inhibition (SLAI), and compared to age-matched healthy controls. In the same AD patients, CSF samples were collected through lumbar puncture to obtain individual levels of Aβ42, total Tau (t-Tau) and phosphorylated Tau (p-Tau) (Thr181). SLAI was decreased in AD patients in comparison to age-matched healthy controls. We found that in patients there was a negative correlation between the individual amount of cholinergic activity assessed by SLAI and the CSF levels of Aβ42. On the other hand, there was a positive correlation between the levels of SLAI and CSF p-Tau. No correlation was found when SLAI was analysed together with t-Tau. These results demonstrate that mechanisms of cortical cholinergic activity are altered in patients bearing a pathological CSF hallmark of AD, suggesting that these peptides may have some influence on the cholinergic dysfunction in AD. We suggest that coupling of CSF biomarkers with neurophysiological parameters of central cholinergic function could be important to better detect ongoing mechanisms of neural degeneration in vivo.

Objective: Cortico-cortical circuits originating from the posterior parietal cortex (PPC) of the intact left hemisphere (LH) may become hyperexcitable in patients with hemispatial neglect due to a right hemispheric (RH) stroke. Methods: In the current randomized, double-blind, sham-controlled study, we investigated safety and efficacy of continuous theta-burst stimulation (cTBS) in 10 sessions over 2 weeks applied over the intact PPC of the LH in subacute ischemic stroke patients. Severity of neglect was assessed through the standardized Behavioral Inattention Test (BIT). We also measured, by means of bifocal transcranial magnetic stimulation (TMS), how cTBS modified the excitability of the parieto-frontal functional connections in the intact LH. Results: We found that 2 weeks of cTBS, but not sham cTBS, were effective in improving neglect symptoms as measured by BIT score. BIT scores improved by 16.3% after 2 weeks of cTBS and 22.6% at 1 month follow-up. We also found that hyperexcitability of LH parieto-frontal circuits was reduced following treatment with real but not sham cTBS. Conclusion: These findings suggest that a 2-week course of cTBS over the LH PPC may be a potential effective strategy in accelerating recovery from visuospatial neglect in subacute stroke patients, possibly counteracting the hyperexcitability of LH parieto-frontal circuits. Classification of evidence: This study provides Class III evidence that left posterior parietal cortex theta-burst stimulation improves hemispatial neglect for up to 2 weeks after treatment.

Visuospatial abilities are preferentially mediated by the right hemisphere. Although this asymmetry of function is thought to be due to an unbalanced interaction between cerebral hemispheres, the underlying neurophysiological substrate is still largely unknown. Here, using a method of trifocal transcranial magnetic stimulation, we show that the right, but not left, human posterior parietal cortex exerts a strong inhibitory activity over the contralateral homologous area by a short-latency connection. We also clarify, using diffusion-tensor magnetic resonance imaging, that such an interaction is mediated by direct transcallosal projections located in the posterior corpus callosum. We argue that this anatomo-functional network may represent a possible neurophysiological basis for the ongoing functional asymmetry between parietal cortices, and that its damage could contribute to the clinical manifestations of neglect.

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Lo studio rilegge e reinterpreta il canto V dell' "Orlando Furioso" in base a nuove fonti e a nuovi modelli intertestuali. Si sofferma inoltre sulla peculiarità della struttura narrativa e sulle modalità di rappresentazione dei personaggi.

The aim of this study was to develop a packed bed reactor (PBR) process for the on-site aerobic cometabolic bioremediation of a groundwater contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). With regard to the growth substrate selection, the comparison of the CAH degradation performances obtained with 5 candidate substrates led to the selection of butane and to the development from the site’s indigenous biomass of a suspended-cell consortium capable to degrade TCE (TCE first-order constant = 96 L gprotein-1 d-1 at 30 °C and 4.3 L gprotein-1 d-1 at 15 °C) with a 90% mineralization of the organic Cl. Based on PCR-DGGE analysis of the 16S rRNA genes followed by band excision and sequencing, the microbial consortium enriched was mainly composed of Bacteroidetes and Alpha- and Beta-Proteobacteria that were distantly related to known CAH-cometabolizing bacteria. The low TeCA degradation rate by the developed consortium suggested the introduction of a chemical pre-treatment based on the TeCA to TCE conversion via -elimination, a very fast reaction at alkaline pH. The choice of the best-performing carrier was made by means of a 2-level procedure: the 1st level consisted of batch tests, operated both at 30 and 15 °C, whereas the 2nd level consisted of continuous-flow tests, operated at 30 °C. A porous ceramic carrier named Biomax resulted the best-performing one. On the basis of the kinetic parameters relative to TCE aerobic cometabolic biodegradation by the selected consortium, a 31-L packed-bed reactor, consisting of 14 columns connected in series, packed with Biomax and immerged in a temperature-controlled bath, was designed and set-up. The preliminary data, obtained by operating the plant with a 4-day residence time, indicate the attainment of a 0.1 mg L-1 d-1 TCE biodegradation rate.

A procedure for the design of a packed bed reactor (PBR) process for the on-site aerobic cometabolic bioremediation of a groundwater contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA) was developed. The comparison of the CAH degradation performances obtained with five substrates led to the selection of butane and to the development from the site’s indigenous biomass of a consortium capable to degrade TCE, with a 90% mineralization of the organic Cl. A porous ceramic carrier (Biomax) resulted the best option for the PBR process. On the basis of the kinetic analysis, a 31-L PBR, consisting of 14 columns connected in series, was designed.

This work is aimed at evaluating the feasibility of a cost-effective process of biological H2 production from food industry wastes under thermophilic conditions. The H2-producing performances of 4 Thermotoga strains (T. neapolitana, T. petrophila, T. naphtophila, T. maritima) were compared at 77 °C by means of tests conducted in 120-mL batch bioreactors containing a nutrient-rich growth medium (ATCC 1977; Van Ooteghem et al., Biotechnol. Lett., 2004, 26:1223) additioned with glucose, molasses or cheese whey as carbon source. For all the substrates tested, T. neapolitana resulted the best-performing strain under suspended-cell conditions, with a 0.9-1.9 mmol / L medium / h H2 production rate at an 8-10 g/L initial substrate concentration, and a 1.6-2.6 mmol H2 / mmol monosaccharide consumed yield. To compare the 4 strains also under attached-growth conditions, preliminary tests were conducted with glucose-growing T. neapolitana, with the goal to select the best biomass carrier among 4 porous materials utilized in biofiltration applications. The best results were obtained with the carrier characterized by the highest interfacial area, equal to 2.1 m2 g-1. Also under attached-growth conditions, T. neapolitana resulted the best strain for all the 3 substrates tested, with a 1.2-1.8 mmol / L medium / h H2 production rate. Further tests, aimed at simplifying the growth medium composition, led to encouraging results. For example, in the case of molasses a minimum medium composed only by NH4Cl, K2HPO4, NaCl, buffer and cysteine resulted – in comparison with the ATCC 1977 complete medium – in a 73% reduction of medium cost and in a 12% increase of the H2/substrate yield. Finally, the process scale-up to a 19-L reactor is in progress. The preliminary results indicate that, in the scale-up of batch H2 production from glucose by T. neapolitana, the values of the three monitored yields (H2/substrate, organic acids/substrate, biomass/substrate) did not show significant variations, whereas the H2 volumetric production and the initial H2 production rate resulted to be significantly affected by the concentration of the initial inoculum.

Bio-hydrogen production from organic residues is an attractive process that combines energy generation with waste treatment. This work describes hydrogen production from glucose, molasses and cheese whey by 4 hyperthermophilic Thermotoga strains. In experiments with glucose-fed T. neapolitana, the best H2 rate was obtained with the biofilm support characterized by the highest specific surface. All the 4 Thermotoga strains examined (T. neapolitana, T. maritima, T. naphtophila, T. petrophila) could produce H2 from glucose, molasses and cheese whey under both suspended- and attached-cell conditions. With all the three substrates, T. neapolitana resulted the best H2 producer. The best H2 production rate was higher on molasses (1.7 mmol H2 / L medium / h) than on cheese whey (0.94 mmol H2 / L medium / h), whereas the highest H2/substrate yields were similar between the two substrates.

This work focuses on the enrichment of a trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA) cometabolizing aerobic microbial consortium from a contaminated site in Northern Italy, for the development of an on-site bioremediation treatment. The goals were: (i) to select the best growth substrate and the best-performing consortium in terms of contaminant degradation capability; (ii) to perform a preliminary suspended-cell kinetic test; (iii) to perform a preliminary evaluation of the feasibility of the co-metabolic treatment of the tested groundwater in a packed-bed reactor operating at the site’s temperature (15°C). The best degradation results were obtained with a butane-growing consortium. At 15° C, the selected culture resulted in short lag-times for the onset of butane utilization (< 1 day) and TCE and TeCA degradation (< 1 - 8 days). Once immobilized on 4 different porous carriers, the selected consortium was able to grow and form a stable biofilm. The TCE and TeCA degradation rates resulted similar for the 4 carriers tested. Further experiments are in progress to estimate the kinetic parameters of the co-metabolic processes and to understand which carrier leads to the best performances in a continuous-flow packed-bed reactor process.

Chlorinated aliphatic hydrocarbons (CAHs) are toxic and environmental hazardous solvents increasingly detected in soil and groundwater for which new and most effective biormemdiation approaches are needed. In this context, the European project MINOTAURUS is aiming to develop groundwater bioremediation robust and reliable strategies based on the use of immobilized biocatalysts. This work was focused on the enrichment of aerobic trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA) co-metabolizing microbial cultures from a contaminated site in Rho (MI, Italy), their preliminary characterization both as freely suspended and immobilized biomass on different carrier materials (Biomax®, Biopearl®, Biomech®, Cerambios®) and the selection of the best performing culture to be employed in a continuous Packed Bed Reactor (PBR) process. The best performing culture was obtained through serial enrichment on filter sterilized site-water or a similar synthetic water in the presence of butane (2 mg/L) as carbon and energy source and TCE (10 mg/L) plus TeCA (3 mg/L). The structure and composition of the microbial population was carried out through denaturing gradient gel electrophoresis (DGGE) analysis of the 16S rRNA genes. The DGGE analysis outlined that the structure of the suspended microbial community changed remarkably throughout the enrichment with the exception of the most prominent phylotype. However, according to the Dice similarity coefficient, lower changes occurred during the last sub-culturing step, indicating a gradual stabilization of the community structure. When immobilized on different carriers, the most prominent phylotype previously detected represented a minor fraction of the immobilized community; conversely, several of the minor bands occurring in the suspended culture became dominant within the biofilm. Such a drastic change in the structure of the microbial community was evidenced by the separate clustering of the DGGE profiles from suspended cell cultures and biofilms. Furthermore, the high similarity indexes between the communities immobilized on different carriers (57.3% to 73.7%) suggest that the evolved consortium is quite stable and that the material and shape of the carrier do not affect remarkably its composition. Complementary information obtained from degradation kinetic tests showed that the selected culture immobilized on Biomax® retained the highest degrading activity. Identification of the community members via band sequencing and phylogenetic analysis is in progress and will allow to obtain key information on the potential TCE and TeCA co-metabolizing species both in the suspended and in the immobilized communities.

Today there is growing a search for renewable, low-cost and low-emission energy sources. This work is aimed at assessing the technical and economic feasibility of a biological process of H2 production from food industry waste in thermophilic conditions. The production of H2 by 4 strains of the genus Thermotoga (T. neapolitana, T. petrophila, T. naphtophila, T. maritima) was studied at 77°C in batch bioreactors (120 mL) with glucose, molasses and whey as carbon sources. With all the substrates tested, T. neapolitana gave the best results, with an initial H2 production rate of 1.2–1.9 mmol Lmedium-1 h-1 and a selectivity of 1.6–2.6 mmolH2 mmolmonosaccharide consumed-1. Using T. neapolitana, further studies were conducted with cells immobilized on 4 types of porous supports (3 vitreous ones and a ceramic one). The best results were obtained with the ceramic support, characterized by the maximum interfacial area (2.1 m2 g−1). Further tests, aimed at simplifying the composition of the growth medium, gave encouraging results. For example, in the case of molasses a minimal medium composed only of NH4Cl, K2HPO4, NaCl, buffer and cysteine was identified. In comparison with the complete medium, the minimal medium was characterized by a 73% cost reduction and a 12% increase of the H2/substrate yield. Finally, the process scale-up to a 19-L reactor is in progress. Preliminary results indicate that, in the scale-up of the production of H2 from glucose with T. neapolitana, the values of the three monitored yields (H2/substrate, organic acids/substrate and biomass/substrate) showed no significant changes.

BACKGROUND: Bio-hydrogen production from organic residues is an attractive process that combines energy generation with waste treatment. This work describes hydrogen production from molasses and cheese whey by biofilm and suspended-cells of four hyperthermophilicThermotoga spp. For the best performing strain, a preliminary process optimization was performed. RESULTS: In experiments with glucose-fed T.neapolitana, HEPES was the best-performing buffer, whereas the highest H2 rate was obtained with the biofilm support exposing the highest specific surface. All the Thermotoga strains tested (T.neapolitana, T.maritima, T.naphtophila, T.petrophila) were able to produce H2 from glucose, molasses and cheese whey under both suspended- and attached-cell conditions. T.neapolitana was the best H2 producer with all three substrates. The best H2 production rate was higher on molasses (1.7 mmolH2 L −1 medium h −1 ) than on cheese whey (0.94 mmolH2 L −1 medium h −1 ), whereas the highestH2/substrateyieldsweresimilarforthetwosubstrates(2.95 molH2 mol −1 monosaccharide consumed onmolassesand2.50 molH2 mol −1 monosaccharide consumed on cheese whey). With both wastes, the progressive growth medium simplification allowed a drastic reduction of medium cost, without significant losses of process performance. CONCLUSION: Both molasses and cheese whey are suitable substrates for H2 production by suspended- and attached-cells of Thermotoga species. c � 2012 Society of Chemical Industry Supportinginformationmaybefoundintheonlineversionofthisarticle.

The aim of this work was to develop a high-performing microbial consortium capable to degrade trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA) via aerobic co-metabolism in packed bed reactors (PBRs). To this goal, five groundwaters were sampled from different monitoring wells in an aquifer contaminated by TCE and TeCA, and 25 119-mL batch tests were set up to test five different growth substrates: methane, propane, butane, pentane and phenol. Substrate and oxygen were periodically re-added. TCE and TeCA were spiked at increasing concentrations in order to select microorganisms able to rapidly degrade TCE and TeCA. Preliminary DGGE analysis showed appreciable differences in the microbial populations enriched. Butane was identified as the best-performing growth substrate, and a high-performing butane-growing consortium (B4) was selected for the subsequent continuous-flow tests. The selection was made on the basis of the substrate, TCE and TeCA specific biodegradation rates. Consortium B4 showed a specific rate of 129 L/g protein/day for TCE and 2.6 L/g protein/day for TeCA. The first value is comparable to the rates attainable in active carbons adsorption processes, with the great advantage of the total mineralization of the chlorinated hydrocarbons (Segar et al., Water Environ. Res. 1995;67:764-774). The highest co-metabolized concentrations were 10 mg/L for TCE and 3 mg/L for TeCA. Specific tests aimed at developing and calibrating a kinetic model of substrate consumption and TCE/TeCA degradation are in progress. Attached-cell preliminary tests showed the ability of consortium B4 to form a stable biofilm on porous carriers. The attached biomass was able to utilize butane as carbon source and to biodegrade TCE and TeCA. In order to select the most suitable biofilm carrier for TCE/TeCA aerobic cometabolism by B4 in a PBR, 4 1-L glass columns were filled with 4 types of porous biofilm carriers. Fluid dynamics tests were performed with oxygen, TCE and TeCA in order to estimate the longitudinal dispersivity, the effective porosity and the TCE/TeCA retardation factor of each tested carrier. Four liters of a suspension of consortium B4 were produced in a fermentor in order to colonize the 4 glass columns. Continuous-flow tests of TCE and TeCA cometabolism by biofilms of consortium B4 are in progress, and will be utilized to select the best-performing carrier.

The general purpose of this study was to develop an aerobic cometabolic process in a packed bed reactor to treat groundwater contaminated by trichloroethylene (TCE) and 1,1,2,2-tetrachloroethane (TeCA). The specific goals were to select the best performing microbial consortium for the cometabolic process and the best support for biofilm formation. Groundwater samples taken from 5 wells of the contaminated site were fed with 5 candidate growth substrates. Butane was selected as the best substrate. The first-rate constants obtained with butane were 130 L / g protein / d for TCE and 2.6 L / g protein / d for TeCA. As a result of a study conducted both in batch and continuous bioreactors, Biomax® resulted the best carrier among 4 candidate porous carriers.