Core-level photoemission spectra of Mo0.3Cu0.7Sr2ErCu2Oy, a superconducting perovskite derivative. Unconventional structure-property relationships.

Detailed studies of the electronic states for Mo(0.3)Cu(0.7)Sr(2)ErCu(2)Oy samples with different oxygen contents are presented here. The influence of oxygenation on the electronic states for the Mo(0.3)Cu(0.7)Sr(2)ErCu(2)Oy system from the semiconducting to the superconducting state has been investigated by means of X-ray photoelectron spectroscopy (XPS). The XPS studies show that Mo is in a mixed Mo(V) and Mo(VI) oxidation state and Mo(V) is predominant over the Mo(VI) in the as-prepared (AP) sample. Yet annealing under an oxygen atmosphere enhances the Mo(VI) state. At the same time, a reduction in the copper species is observed. In the Cu 2p spectra, a larger energy separation between the satellite and main peaks (E(S)-E(M)) and a lower intensity ratio (I(S)/I(M)) are found to correlate with higher values of the superconducting transition temperature (T(C)). Analysis of these spectra within the Configuration Interaction (CI) model suggests that higher values of TC are related to lower values of the O 2p-Cu 3d charge transfer energy. The change in the Sr 3d and O 1s core level spectra correlates with the oxygen insertion in the (Mo/Cu)O(1+δ) chain site, after oxygenation. The hole concentration (Ph) in the copper plane has been obtained using the room temperature thermoelectric power (TEP) value; this shows an increasing tendency with increasing T(C), after oxygenation. From these experimental results, one observes that T(C)increases with decreasing charge transfer energy. This is, indeed, opposite to the accepted views and occurs in parallel with the shortening of the apical copper-oxygen distance (Cu(2)-O(2)) and the increasing of the CuO(2) plane buckling angle.

Huperzia saururus Lam. Trevis. (Lycopodiaceae) facilitates ejaculation in spinal cord transected male rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Huperzia saururus (Lam.) Trevis. has an extensive ethnopharmacological use, mainly because of its aphrodisiac properties. The species is consumed as decoctions or infusions in traditional medicine. The purpose of the present research was to determine if Huperzia saururus is able to increase sexual potency by evaluating the ejaculatory response, in the presence of a decoction in spinal cord transected male rats. MATERIALS AND METHODS: The fictive ejaculation model to record the rhythmic contractions of the bulbospongiosus muscles that accompany ejaculation as an indicator of ejaculation occurrence was used. Sexually experienced male Wistar rats were used. The activation of the fictive ejaculation by the i.v. administration of a decoction was tested, as well as the effects of the oxytocinergic, cholinergic, adrenergic and nitrergic antagonism upon the pro-ejaculatory activity of Huperzia saururus. RESULTS: Decoction (3µg/animal) was able to activate the fictive ejaculation in spinal male rats, producing a statistically significant diminution on the latency of discharge parameter and a statistically significant augment for the number of discharges. Moreover, when sequential treatments using antagonists plus decoction were administered, the effects produced showed that prazosin prevent the pro-ejaculatory effect of the decoction and that the four antagonists assayed blocked the facilitatory effect of Huperzia saururus since the facilitation in the latency of response was prevented, and the number of discharges was reduced. Together these findings support the notion that the decoction exerts an aphrodisiac effect influencing the ejaculatory potency which is partially mediated by oxytocinergic, cholinergic, adrenergic and nitrergic spinal mechanisms. CONCLUSION: In agreement to the ethnopharmacological uses, Huperzia saururus decoction has aphrodisiac properties by influence on the ejaculatory potency.

Accumulation trends of petroleum hydrocarbons in commercial shellfish from the Galician coast (NW Spain) affected by the Prestige oil spill.

Aliphatic and aromatic hydrocarbons were determined in three species of commercial shellfish, namely razor shells (Ensis arcuatus and Ensis siliqua), goose barnacle (Pollicipes cornucopia) and sea urchin (Paracentrotus lividus), living in different habitats and exhibiting different feeding behaviors. The samples were collected monthly, from January 2003 to October 2004, in three stations of the Galicia coast (NW Spain), following the Prestige oil spill, with the aim of assessing their response to the spill and, therefore, their suitability for monitoring purposes. The aliphatic fractions were mostly dominated by biogenic hydrocarbons, reflecting the diet composition of the organisms and their low metabolic capacity. The presence of oil was assessed by the determination of chemical markers. The analysis of the aromatic fractions revealed the occurrence of 3-6 ring parent and alkylated PAHs, consistent with a mixed petrogenic-pyrolytic origin, with the common feature of the predominance of chrysene in all samples collected after the spill. However, the distributions exhibited both temporal and interspecies variations. The PAH concentrations (Sigma13) increased significantly after the spill and decreased 6-7 months later close to background levels for the region. One year after the accident, the median values were: 58 microg/kg for razor shells, 26 microg/kg for barnacles, and 25 microg/kg for sea urchins. The temporal evolution of the PAH concentrations along the survey period was used to estimate loss rates for bioavailable PAHs in barnacles and sea urchins after the spill. Half-life values were in the order of 30 and 60 d, respectively. The results of the study demonstrate that barnacles can be suitable species for oil spill monitoring.

Spatial and temporal trends of petroleum hydrocarbons in wild mussels from the Galician coast (NW Spain) affected by the Prestige oil spill.

Polycyclic aromatic hydrocarbons (PAHs) were determined in tissues of wild mussels (Mytilus galloprovincialis) from the Galicia coast (NW Spain) in order to assess the extent of the environmental impact caused by the Prestige oil spill (November 13, 2002). Three sampling campaigns were carried out in February, June and November 2003 at 24 stations along the Galicia coast, from La Guardia (Pontevedra) to Ribadeo (Lugo). The spatial distribution of PAHs found in the first sampling period, clearly revealed the central area (Costa da Morte) as the most affected by the oil spill. In these stations, concentrations up to 7780 microg/kg dw of the sum of 13 parent PAHs were found 2-3 months after the spill. Molecular parameters within the aliphatic and aromatic fractions confirmed the presence of the Prestige oil in these samples. The levels markedly decreased at most of the stations in the second sampling and recovered to levels found before the spill in November 2003, 1 year after the accident (29-279 microg/kg dw, av. 133+/-83 microg/kg dw). However, a certain increase was observed in some sites which could be related to the remobilization of oil residues from still unclean intertidal spots or sediments due to the winter marine weather conditions.

Antiobesity effects of the novel in vivo neutral cannabinoid receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-hexyl-1H-1,2,4-triazole--LH 21.

The present study evaluates the pharmacological profile of the new neutral cannabinoid CB1 receptor antagonist 5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-3-hexyl-1H-1,2,4-triazole -LH-21- on feeding behavior and alcohol self-administration in rats, two behaviors inhibited by cannabinoid CB1 receptor antagonists. Administration of LH-21 (0.03, 0.3 and 3 mg/kg) to food-deprived rats resulted in a dose-dependent inhibition of feeding. Subchronic administration of LH-21 reduced food intake and body weight gain in obese Zucker rats. Acute effects on feeding were not associated with anxiety-like behaviors, or induction of complex motor behaviors such as grooming or scratching sequences, usually observed after central administration of cannabinoid receptor blockers with inverse agonist properties. LH-21 did not markedly reduce alcohol self-administration (30% reduction observed only at a high dose of 10 mg/kg). This pharmacological pattern partially overlaps that of the reference cannabinoid CB1 receptor antagonist N-piperidino-5-(4-chlorophenyl)-1-(2,4-dichlorophenyl)-4-methylpyrazole-3-carboxamide, SR141716A, (0.3, 1 and 3 mg/kg) that reduced feeding and alcohol self-administration with similar efficacy. In vitro analysis of blood-brain barrier permeability using a parallel artificial membrane permeation assay demonstrated that LH-21 has lower permeation through membranes than SR141716A. That was confirmed in vivo by studies showing lower potency of peripherally injected LH-21 when compared to SR141716A to antagonize motor depression induced by intracerebroventricular administration of the CB1 agonist CP55,940. The neutral antagonist profile and the lower penetration into the brain of LH-21 favour this class of antagonists with respect to reference inverse agonists for the treatment of obesity because they potentially will display reduced side effects.