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Abstract: VO x /SiO2 catalysts were prepared through an innovative flame pyrolysis (FP) technique and tested for the oxidative dehydrogenation of propane. The samples, of different V loadings, were characterized by electron paramagnetic resonance (EPR), micro-Raman, and FT-IR spectroscopy to assess the nature of the vanadium active sites in comparison with a sample prepared by impregnation. The active sites of the FP-prepared catalysts appeared as highly dispersed V5+O groups partly incorporated into the silica matrix and interacting poorly with one another. Lower dispersion can be achieved at the same V loading with the catalyst prepared by impregnation. EPR revealed V4+O groups pointing out normally from the catalyst surface and sitting in the center of a surface array of oxygen atoms. These V4+ groups helped demonstrate the difference in catalytic behavior of the various samples. Catalytic activity measured under both aerobic and anaerobic conditions revealed a promisingly high selectivity with the FP-prepared samples. The best results were obtained with a 10 wt% V loading, which provided the best propylene yield among the samples, especially under anaerobic conditions (up to 80% selectivity at 10% propane conversion). This is likely related to the much higher dispersion of the VO x species in the FP-prepared samples, which also helps reduce the coke formation triggered by exposed surface acid sites. [Copyright &y& Elsevier]

A set of La1− x A′ x Co1− y Fe y O3±δ samples (A′ = Ce,Sr; x = 0.1, 0.4, y = 0, 0.5, 0.8, 1) was prepared by means of the sol–gel citrate method and characterised through X-ray diffraction (XRD), N2 adsorption/desorption and temperature programmed desorption–reduction (TPD-TPR). Their activity for the catalytic flameless combustion of methane was tested and the results interpreted focusing on the effect of doping at A and/or B position. It was found that Ce doping of lanthanum ferrite catalysts could suppress suprafacial activity and slightly enhance intrafacial activity, due to the change of oxygen mobility. However, catalytic activity seems independent of the type of electronic conductivity ( p- or n-type), the activity of an analogously Sr-doped sample being similar to that of the Ce-doped one. Mixed B-metal composition can help in modulating both oxygen mobility and catalyst stability under reducing reaction conditions. High Fe content allows to optimise this last parameter. However, depression of oxygen mobility and hence of activity has to be prevented by proper doping at A-position. [ABSTRACT FROM AUTHOR]

Abstract: The activity of honeycomb supported LaBO3±δ (B=Fe, Mn and Co) and La2NiO4 was tested for the catalytic flameless combustion (CFC) of methane and compared with their catalytic behaviour in powder form. Catalyst supporting brought about some modifications, mainly the complete loss of the suprafacial activity. Furthermore, thermal resistance of supported samples was checked through accelerated deactivation tests and showed to strongly depend on the nature of the B ion. Structural and morphological properties of fresh and aged catalysts, both in powder form (either pure or mixed with the primer precursor) and as honeycomb-supported samples, were compared to investigate the effect of each step of the dip-coating procedure. This allowed to shed light on the causes of the structural and chemical changes occurring during the wash-coating and leading to more or less severe decrease of performance and of thermal resistance of the final catalyst. [Copyright &y& Elsevier]

Abstract: Several samples of Sr1–x Ag x TiO3±δ (, 0.1) perovskite-structured catalysts were prepared and tested for the title reaction under lean-burn conditions. For the same overall nominal composition, catalyst activity and durability depend strongly on the method of preparation and, for the samples prepared by the same method, mainly on temperature and on the residence time at such a temperature during preparation. In Sr0.9Ag0.1TiO3±δ catalysts Ag is present either as intra-crystalline Ag2+, likely substituting for Sr2+ in the perovskite lattice, or as inter-crystalline metallic Ag. The catalytic activity of Sr0.9Ag0.1TiO3±δ is connected with the presence of , , and ; of , O−/Sr2+; or of O−/Ti4+ species, depending on preparation method and conditions. Furthermore, inter-crystalline metallic Ag plays an important role in improving catalyst resistance to sintering; the most durable samples are those calcined for a sufficient residence time at the highest temperature during preparation, that is, under conditions more favourable to the segregation of this metal from the perovskite lattice. [Copyright &y& Elsevier]

Abstract: To understand better the effect of La2O3 as primer for the preparation of honeycomb supported La0.9Ce0.1CoO3±δ catalyst, some samples were prepared starting from different La-precursors. Physical and morphological properties of both the primer-coated honeycomb and its precursors (as-prepared and after thermal treatment at different temperature) have been investigated by TGA, TPD–MS, XRD and SEM. Calcination at high temperature brought about a rearrangement of both primer and active phase morphology. When La acetate was used as precursor, such a transformation seemed not to alter substantially the morphology of the primer layer, leading to a poorer anchoring to the support, with deep cracking and exfoliation of the La oxide platelets so formed. By contrast, when the primer precursor was La nitrate, the higher reactivity of the hydroxynitrates, forming during calcination, with respect to both the active phase and the honeycomb, led to a more uniform and compact La2O3 layer, anchoring much better the perovskite to the monolith support. [Copyright &y& Elsevier]

Abstract: A set of LaMnO3 and LaCoO3 catalysts was prepared through different synthesis procedures. The selected techniques included the sol–gel method, flame hydrolysis from aqueous solution, complexation through EDTA and solid-state reaction. The last was accomplished through reactive grinding by ball-milling either in a vibration mill or in a planetary mill. EDTA complexation was applied for LaCoO3 only and did not improve significantly catalyst activity or stability, with respect to other techniques. Ball-milling never allowed obtaining a pure perovskitic phase, at least under the most energetic grinding conditions permitted by our apparatus. The highest activity for the catalytic flameless combustion of methane was obtained with the sol–gel prepared samples, though thermal resistance revealed insufficient for high temperature applications. A bit lower activity, but coupled with good thermal stability was obtained with the samples prepared through flame hydrolysis. [Copyright &y& Elsevier]

Background: Serotonin (5-HT) is a well-known modulator of eating behavior. However, the molecular mechanisms linking its action to body weight balance have been only partially elucidated. Since platelets are a suitable peripheral model to study 5-HT transport, metabolism and release, we herein evaluated the expression of the platelet 5-HT re-uptake system (SERT) by [3H]-paroxetine binding assay. A cohort of 114 unrelated individuals (34 males, 80 females; age, mean ± SD: 38.57 ± 12.47 years) without major psychiatric disorders, was recruited following a naturalistic design regarding age or gender and classified accordingly to their body mass index (BMI). Subjects were divided into 5 groups: normal-weight (NW), overweight (OW) and grade I-III obese (OB) individuals. For gender analyses, data were transformed into [3H]-paroxetine density (Bmax)/BMI ratios to overcome both the disparity of women vs. men number and anthropometric differences between sexes., Results: [3H]-paroxetine Bmax (SERT density, fmol/mg proteins) was reduced in platelet membranes of grade II (p < 0.01) and III (p < 0.001) obese subjects vs. controls and in overweight subjects (p < 0.05) vs. grade III obese individuals. Considering all patients together, a strong negative correlation between Bmax and BMI (r = -0.449; P < 0.0001) was demonstrated. Conversely, [3H]-paroxetine KD (dissociation constant, nM) did not differ among groups. No gender-related variation concerning Bmax/BMI ratios was observed in this cohort of subjects., Conclusions: The down-regulation of SERT in platelet membranes of severe human obesity (BMI > 35 Kg/m2) confirms the involvement of 5-HT system in body weight gain. Moreover, this findings may help to elucidate those monoamine-endocrine networks acting on fat storage, adipocyte signaling and energy balance. Targeting 5-HT/5-HT-related markers will possibly uncover the existence of human obesity subtypes.

The amount of the trace elements As, Ba, Cd, Cr, Cu, Hg, Li, Mn, Ni, Pb, Rb, Se, Sr, and Zn was measured in top soils and edible mushrooms, Boletus edulis, Macrolepiota procera, collected at five distinct green microhabitats inside the Lucca province, North-Central Italy (years 2008-2009). Results showed a top soil element content within the Italian statutory limits. Concerning the amount of mushroom elements, we observed significant species-differences obtaining higher levels of Ni, Rb, and Se in B. edulis or As, Pb, Cu in M. procera. Bioaccumulation factors (BCFs: element in mushroom/element in soil) resulted species-dependent and element-selective: in particular, B. edulis preferentially accumulated Se (BCFs varying from 14 to 153), while M. procera mainly concentrated Cu (BCFs varying from 5 to 15). As well, both species displayed between-site BCF differences. By a multivariate principal component approach, cluster analysis (CA), we could resolve two main clusters of soil element composition, corresponding to the most ecologically divergent sites. Besides, CA showed no cluster relating to element contents of B. edulis at the different collection sites, while a separation in groups was found for M. procera composition with respect to harvesting locations, suggesting uptake systems, in this saprotrophic species, sensitive to microhabitat. Regarding consumer safety, Cd, Hg, Pb levels resulted sometime relevant in present samples, never reaching values from current literature on mushrooms collected in urban-polluted areas. Our findings encourage a deeper assessment of the molecular mechanisms of metal intake by edible mushrooms, encompassing genetic biochemical and geo-ecological variables, with particular awareness to element bioavailability in soils and fungi.

Background: An ever growing body of evidences is emerging concerning metabolism hormones, neurotransmitters or stress-related biomarkers as effective modulators of eating behavior and body weight in mammals. The present study sought at examining the density and affinity of two proteins related to neurotransmission and cell metabolism, the serotonin transporter SERT and the cholesterol import-benzodiazepine site TSPO (translocator protein), in a rodent leptin-lacking mutant, the obese ob/ob mouse. Binding studies were thus carried out in brain or peripheral tissues, blood platelets (SERT) and kidneys (TSPO), of ob/ob and WT mice supplied with a standard diet, using the selective radiochemical ligands [3H]-paroxetine and [3H]-PK11195., Results: We observed comparable SERT number or affinity in brain and platelets of ob/ob and WT mice, whilst a significantly higher [3H]-PK11195 density was reported in the brain of ob/ob animals. TSPO binding parameters were similar in the kidneys of all tested mice. By [3H]-PK11195 autoradiography of coronal hypothalamic-hippocampal sections, an increased TSPO signal was detected in the dentate gyrus (hippocampus) and choroids plexus of ob/ob mice, without appreciable changes in the cortex or hypothalamic-thalamic regions., Conclusions: These findings show that TSPO expression is up-regulated in cerebral regions of ob/ob leptin-deficient mice, suggesting a role of the translocator protein in leptin-dependent CNS trophism and metabolism. Unchanged SERT in mutant mice is discussed herein in the context of previous literature as the forerunner to a deeper biochemical investigation.

Background and Purpose: β₂-Adrenoceptor agonists are important therapeutic agents in the treatment of asthma and chronic obstructive pulmonary disease. The regular use of these drugs has been associated with proasthmatic-like changes that limit their efficacy and increase the risk of severe adverse reactions. We investigated whether the peroxisome-proliferator-activated receptor (PPAR)γ agonist rosiglitazone modulated salbutamol-induced β₂-adrenoceptor desensitization in vivo and in vitro., Experimental Approach: An in vivo model of homologous β₂-adrenoceptor desensitization, established in guinea-pigs by administering salbutamol continuously, was used to study the ability of rosiglitazone to prevent β₂-adrenoceptor tolerance. In vitro experiments on human bronchial smooth muscle cells were performed to increase the clinical relevance of the study., Key Results: In tracheal smooth muscle tissues from desensitized animals, we observed a decrease in the protective effect of salbutamol on carbachol-induced contraction, a hyperresponsiveness to cholinergic stimuli, a modest underexpression of β₂-adrenoceptor gene and a marked decrease in β-adrenoceptor number, relative to control values. Treatment with rosiglitazone preserved salbutamol relaxant activity, mitigated carbachol hyperresponsiveness and partially restored β₂-adrenoceptor binding sites in tracheal tissues from homologously desensitized animals. The highly selective PPARγ agonist, GW1929, reproduced the effect of rosiglitazone, in vivo. In vitro β₂-adrenoceptor desensitization decreased salbutamol-mediated cAMP production, without affecting forskolin responses and β₂-adrenoceptor expression. Rosiglitazone and 15-deoxy-Δ¹²(,)¹⁴-prostaglandin J₂ restored salbutamol sensitivity in homologously desensitized cells., Conclusions and Implications: These data suggest a potential pharmacodynamic interaction between PPARγ agonists and salbutamol on airway smooth muscle responsiveness, supporting the therapeutic potential of this combination in chronic airway disease., (© 2010 The Authors. British Journal of Pharmacology © 2010 The British Pharmacological Society.)

The formation of social bonding is fundamental for several animals, including humans, for its relevant and obvious impact upon reproduction and, thus, survival of the species. Recent data would suggest that oxytocin might be one of the mediators of this process. Given the paucity of data on the possible involvement of oxytocin in human attachment, the present study was aimed to explore the possible relationships between the plasma levels of this neuropeptide and romantic attachment in healthy subjects. Forty-five healthy subjects who volunteered for the study, were included in the study. The romantic attachment was assessed using the Italian version of the so-called "Experiences in Close Relationships" (ECR), a self-report questionnaire for measuring this parameter in adults. The results showed that attachment anxiety and oxytocin are positively linked in romantic attachment to a statistically significant degree (r = 0.30, p = 0.04), that is, the higher the oxytocin levels the higher the score on the anxiety scale of the ECR. The authors suggest the hypothesis that this link represents one of the biological processes resulting in those rewarding emotions related to romantic attachment.

The aim of the study was to evaluate the kinetic parameters of a specific serotonin transporter (SERT) and serotonin uptake in a mentally healthy subset of patients with fibromyalgia. Platelets were obtained from 40 patients and 38 healthy controls. SERT expression and functionality were evaluated through the measurement of [3H]paroxetine binding and the [3H]serotonin uptake itself. The values of maximal membrane binding capacity (Bmax) were statistically lower in the patients than in the healthy volunteers, whereas the dissociation constant (Kd) did not show any statistically significant variations. Moreover, a decrease in the maximal uptake rate of SERT (Vmax) was demonstrated in the platelets of patients, whereas the Michaelis constant (Km) did not show any statistically significant variations. Symptom severity score (tiredness, tender points index and Fibromyalgia Impact Questionnaire) were negatively correlated with Bmax and with Vmax, and positively correlated with Km. A change in SERT seems to occur in fibromyalgic patients, and it seems to be related to the severity of fibromyalgic symptoms.