The Zn-Pb-(Ag) epithermal mineralization of Mazarrón (Spain). A preliminary isotope study

Versión preprintGoldschmidt 2010: "Earth, energy and the environment". June 13-18, Knoxville (Tennessee)The Volcanic Field of SE Spain hosts several precious/base-metal epithermal volcanic-hosted deposits[1]. Among them, Mazarron comprises several volcanic centers of high-K calc-alkaline/shoshonitic composition which show pervasive hydrothermal alteration and related Zn-Pb-Ag mineralization. Deposits occur as stockworks and vein systems of sphalerite, silver-rich galena, pyrite and marcasite with quartz and carbonates. Common Fe-Al sulfates are found in a thick net of decimetre to submillimetre sizeveins. Barite veins are also present. Preliminary sulfur isotope study for the base-metal sulfides show a δ34S range between 5 and 13‰. In contrast, pyrite-marcasite values show a wider δ34S range: between -3 to 29‰, with depleted sulfur in earlier crystals. Barite exhibits a bimodal δ34S distribution: from +14 to +18‰ and around +54‰. δ18Obarite is more homogeneous: between +12 to +17‰); Fe-Al sulfates, show significant variations in isotopic signature of S (2-14‰), O (3 to 13‰ in SO4 and 1 to 11‰ in OH group) and D (-54 to -115‰). O isotope equilibrium between SO4 and OH in these minerals is only established in one case, yielding a temperature of 150ºC and pointing to a typical low-temperature hydrothermal environment. The range in sulfide sulfur isotopic is suggestive of thermochemical sulfate reduction of sea water. The extremely enriched sulfur signatures (pyrite-marcasite and barite) indicating closed system conditions. Isotopic (e.g. depleted deuterium values) and geological evidence also support a magmatic fluid input. The Fe-Al sulfate mineralizing event may represent the waning stage of the hydrothermal system, rather than a supergene event as is invoked in other epithermal deposits with similar sulfur signatures[1]. These data therefore suggest a marine-magmatic origin for the Mazarrón ore-fluids. Mazarron in an unusual and tantalising deposit, the origin of which involved complex mineralizing processes, not typical of epithermal volcanic-hosted deposits.Departamento de Mineralogía y Petrología (Universidad de Granada). Departamento de Mineralogía y Petrología (Universidad del País Vasco). Departamento de Didáctica de las Ciencias Experimentales (Universidad de Granada). Instituto Andaluz de Ciencias de la Tierra (Universidad de Granada- Centro Superior de Investigaciones Científicas

Anomalous basal ganglia connectivity and obsessive-compulsive behaviour in patients with Prader Willi syndrome

BACKGROUND: Prader Willi syndrome is a genetic disorder with a behavioural expression characterized by the presence of obsessive-compulsive phenomena ranging from elaborate obsessive eating behaviour to repetitive skin picking. Obsessive-compulsive disorder (OCD) has been recently associated with abnormal functional coupling between the frontal cortex and basal ganglia. We have tested the potential association of functional connectivity anomalies in basal ganglia circuits with obsessive-compulsive behaviour in patients with Prader Willi syndrome. METHODS: We analyzed resting-state functional MRI in adult patients and healthy controls. Whole-brain functional connectivity maps were generated for the dorsal and ventral aspects of the caudate nucleus and putamen. A selected obsessive-compulsive behaviour assessment included typical OCD compulsions, self picking and obsessive eating behaviour. RESULTS: We included 24 adults with Prader Willi syndrome and 29 controls in our study. Patients with Prader Willi syndrome showed abnormal functional connectivity between the prefrontal cortex and basal ganglia and within subcortical structures that correlated with the presence and severity of obsessive-compulsive behaviours. In addition, abnormally heightened functional connectivity was identified in the primary sensorimotor cortex-putamen loop, which was strongly associated with self picking. Finally, obsessive eating behaviour correlated with abnormal functional connectivity both within the basal ganglia loops and between the striatum and the hypothalamus and the amygdala. LIMITATIONS: Limitations of the study include the difficulty in evaluating the nature of content of obsessions in patients with Prader Willi Syndrome and the risk of excessive head motion artifact on brain imaging. CONCLUSION: Patients with Prader Willi syndrome showed broad functional connectivity anomalies combining prefrontal loop alterations characteristic of OCD with 1) enhanced coupling in the primary sensorimotor loop that correlated with the most impulsive aspects of the behaviour and 2) reduced coupling of the ventral striatum with limbic structures for basic internal homeostasis that correlated with the obsession to eat

Doped TiO2 anodic layers of enhanced antibacterial properties

Ti-6Al-4V joint replacement implants foster uncemented fixation in orthopaedic surgery. However, bacterial colonization competes with host cells and ultimately may produce implant-related difficult-to-treat infections, justifying the efforts to obtain infection-resistant materials. In a previous work, the authors demonstrated the antibacterial properties of anodic fluoride-TiO2 nanostructured layers on Ti-6Al-4V alloy. In this work, the anodizing bath has been modified in order to grow fluoride-TiO2 barrier layers (FBL). A bacterial adherence protocol, run with reference and six different clinical strains of Staphylococcus aureus and Staphylococcus epidermidis, showed a statistically significant decrease in the percentage of covered surface (p<0.0001, Kruskal-Wallis test) for FBL specimens when compared with non fluoride-containing specimens, i.e. chemically polished Ti-6Al-4V and F-free TiO2 barrier layers. The results obtained on the F-barrier layers allowed discrimination between the effects of the presence of fluoride in the layer and the layer nanostructure on bacterial adhesion. © 2013 Elsevier B.V.Peer Reviewe

Multidimensional Evaluation of Awareness in Prader-Willi Syndrome

There are no studies about insight or awareness of illness in patients with Prader-Willi Syndrome (PWS). The objective of this study was to explore the level of awareness of the disorder, of the need for medication, and of the social consequences of the disease, as well as of its main symptoms in PWS. We also aimed to explore relationships between awareness and sociodemographic and clinical characteristics, and to compare all data with a matched sample of patients with psychosis. Insight was assessed by an Adapted version of the Scale of Unawareness of Mental Disorder in a cross-sectional pilot study at a University Hospital. Thirty-six individuals with PWS (58.3% women) were included. Results showed that PWS patients had a good awareness of the illness and of the effects of medication, in contrast to a lack of awareness of illness' social consequences. Awareness of obesity/overweight was excellent, as was the awareness of excessive appetite. Awareness of excessive food intake was only mild. Insight correlated with age and functionality, but not with BMI. PWS patients showed a better insight into the illness but a similar awareness of the effects of the medication and of the social consequences of the disease as compared to schizophrenia-spectrum patients. This profile of insight may have relevant clinical implications

Social Responsiveness and Psychosocial Functioning in Adults with Prader&ndash;Willi Syndrome

Although various studies have investigated symptoms of autism spectrum disorder (ASD) in Prader&ndash;Willi syndrome (PWS), little is known about the consequences of these symptoms, especially in psychosocial function. We aimed to explore ASD symptoms in adults with PWS with special attention to psychosocial functionality. This cross-sectional study included 26 adults (15 women) with PWS who attended a reference unit for rare diseases. Participants&rsquo; primary caregivers completed the Social Responsiveness Scale (SRS), and clinicians assessed multidimensional functioning with the Personal and Social Performance Scale (PSP). Impaired social responsiveness was identified in 20 (76.9%) participants, and manifest to marked difficulties in social functioning were identified in 13 (50%). Participants with impaired social responsiveness (SRS &ge; 60) had significantly worse scores in functionality measured with the PSP (U = 12.5; p = 0.009) and with three of the four PSP main areas. Moreover, scores for the Social Cognition domain of the SRS correlated positively with the Socially useful activities (p &lt; 0.05) and Personal and social relationships (p &lt; 0.01) main areas of the PSP. These results suggest that difficulties in social skills should be assessed in all psychosocial evaluations of patients with PWS

Determinants of Severity in Acute Pancreatitis : A Nation-wide Multicenter Prospective Cohort Study

OBJECTIVE: The aim of this study was to compare and validate the different classifications of severity in acute pancreatitis (AP) and to investigate which characteristics of the disease are associated with worse outcomes. SUMMARY OF BACKGROUND DATA: AP is a heterogeneous disease, ranging from uneventful cases to patients with considerable morbidity and high mortality rates. Severity classifications based on legitimate determinants of severity are important to correctly describe the course of disease. METHODS: A prospective multicenter cohort study involving patients with AP from 23 hospitals in Spain. The Atlanta Classification (AC), Revised Atlanta Classification (RAC), and Determinant-based Classification (DBC) were compared. Binary logistic multivariate analysis was performed to investigate independent determinants of severity. RESULTS: A total of 1655 patients were included; 70 patients (4.2%) died. RAC and DBC were equally superior to AC for describing the clinical course of AP. Although any kind of organ failure was associated with increased morbidity and mortality, persistent organ failure (POF) was the most significant determinant of severity. All local complications were associated with worse outcomes. Infected pancreatic necrosis correlated with high morbidity, but in the presence of POF, it was not associated to higher mortality when compared with sterile necrotizing pancreatitis. Exacerbation of previous comorbidity was associated with increased morbidity and mortality. CONCLUSION: The RAC and DBC both signify an advance in the description and differentiation of AP patients. Herein, we describe the complications of the disease independently associated to morbidity and mortality. Our findings are valuable not only when designing future studies on AP but also for the improvement of current classifications