Experimental Crystallization of a High-K Arc Basalt: the Golden Pumice, Stromboli Volcano (Italy)

International audienceThe near-liquidus crystallization of a high-K basalt (PST-9 golden pumice, 49·4 wt % SiO2, 1·85 wt % K2O, 7·96 wt % MgO) from the present-day activity of Stromboli (Aeolian Islands, Italy) has been experimentally investigated between 1050 and 1175°C, at pressures from 50 to 400 MPa, for melt H2O concentrations between 1·2 and 5·5 wt % and {Delta}NNO ranging from –0·07 to +2·32. A drop-quench device was systematically used. AuPd alloys were used as containers in most cases, resulting in an average Fe loss of 13% for the 34 charges studied. Major crystallizing phases include clinopyroxene, olivine and plagioclase. Fe–Ti oxide was encountered in a few charges. Clinopyroxene is the liquidus phase at 400 MPa down to at least 200 MPa, followed by olivine and plagioclase. The compositions of all major phases and glass vary systematically with the proportion of crystals. Ca in clinopyroxene sensitively depends on the H2O concentration of the coexisting melt, and clinopyroxene Mg-number shows a weak negative correlation with {Delta}NNO. The experimental data allow the liquidus surface of PST-9 to be defined. When used in combination with melt inclusion data, a consistent set of pre-eruptive pressures (100–270 MPa), temperatures (1140–1160°C) and melt H2O concentrations is obtained. Near-liquidus phase equilibria and clinopyroxene Ca contents require melt H2O concentrations <2·7–3·6 and 3 ± 1 wt %, respectively, overlapping with the maximum frequency of glass inclusion data (2·5–2·7 wt % H2O). For olivine to crystallize close to the liquidus, pressures close to 200 MPa are needed. Redox conditions around {Delta}NNO = +0·5 are inferred from clinopyroxene compositions. The determined pre-eruptive parameters refer to the storage region of golden pumice melts, which is located at a depth of around 7·5 km, within the metamorphic arc crust. Golden pumice melts ascending from their storage zone along an adiabat will not experience crystallization on their way to the surface

PLANT EXTRACTS AS GREEN POTENTIAL STRATEGIES TO CONTROL THE BIODETERIORATION OF CULTURAL HERITAGE

The biodeterioration of historic-artistic manufacts is related to several biological systems, including fungi and bacteria, whose metabolic activities and vegetative development have a direct consequence on the conservation of cultural assets. Generally, different chemical compounds are utilized as biocides in order to control biodeteriogens growth, but recently the attention has been focused on potential risks of their use towards human health (operators, visitors) and the environment. In order to develop alternative methods, various natural products have been tested, particularly to control the colonization by fungi and bacteria. In this study, antimicrobial activity of three different plant products, Tea tree essential oil, Calamintha nepeta and Allium sativum L. extracts, has been evaluated against Bacillus subtilis, Micrococcus luteus, Penicillium chrysogenum and Aspergillus spp. (previously isolated from colonized artworks) through three different in vitro antimicrobial assays (micro-dilution in microtiter plates, well plates diffusion and agar disc diffusion method). The bioassays show a different microbial susceptibility to plant extracts, establishing for each bacteria and fungi the Minimum Inhibitory Concentration (MIC) and defining the diameter of the growth inhibition area. This result supports the data reported in literature and shows an important potential suggestion for the possible use in the control of biodeterioration of cultural heritage, safe both for human health and environment

Ascent of Stromboli yellow pumice magmas : experimental simulation at P<=4 KB.

Stromboli volcano is characterised by a persistent, mildly explosive activity producing a crystal-rich HK- basaltic scoria. The normal activity is periodically interrupted by more energetic explosions during which a crystal-poor HK basaltic pumice is emitted (yellow pumice), often intermingled with the crystal-rich scoria. We experimentally investigated the ascent path of the yellow pumice from the inferred depth of segregation ˜12 km to a very shallow level, where it interacts with the already degassed resident magma

Proton Zemach radius from measurements of the hyperfine splitting of hydrogen and muonic hydrogen

While measurements of the hyperfine structure of hydrogen-like atoms are traditionally regarded as test of bound-state QED, we assume that theoretical QED predictions are accurate and discuss the information about the electromagnetic structure of protons that could be extracted from the experimental values of the ground state hyperfine splitting in hydrogen and muonic hydrogen. Using recent theoretical results on the proton polarizability effects and the experimental hydrogen hyperfine splitting we obtain for the Zemach radius of the proton the value 1.040(16) fm. We compare it to the various theoretical estimates the uncertainty of which is shown to be larger that 0.016 fm. This point of view gives quite convincing arguments in support of projects to measure the hyperfine splitting of muonic hydrogen.Comment: Submitted to Phys. Rev.

THE VALUE OF DIAGNOSTIC ULTRASOUND FOR DETECTING OCCULT INGUINAL HERNIA IN PATIENTS WITH GROIN PAIN

Aims: chronic groin pain caused by an occult hernia can be a difficult clinical diagnosis and may require additional investiga- tive modalities. The aim of this study was to demonstrate the accuracy of ultrasound in diagnosing occult hernia in patients with recurrent inguinal pain and a negative clinical examination. Patients and methods: over a period of three years, a total of 76 patients were referred for ultrasound examination with clini- cally suspected occult inguinal hernia. Patients with positive US scans were offered surgery, while those with negative US findings were offered further imaging or other diagnostic tests. The ultrasound examination of the inguinal region was conducted using a 5- 10 MHz linear probe. The scan was performed with the patient in the supine and erect positions, in a relaxed state, as well as during coughing and during a Valsalva manoeuvre. Results: overall, ultrasound diagnosed 31 inguinal hernias and all 31 patients with positive scans underwent surgery. Surgery confirmed the ultrasound diagnosis in 30 patients, having only 1/31 no hernia at operation (100% ultrasound sensitivity and 96.9% specificity). Patients undergoing surgery showed complete symptom resolution at a three-month follow-up. Conclusions: this study confirms that ultrasound is capable of accurately diagnosing groin hernia and this may justify its use in patients with chronic groin pain due to a suspected occult herni

Antibiotic-Induced Liver Injury in Paediatric Outpatients: A Case-Control Study in Primary Care Databases

Introduction: Antibiotics are the most commonly prescribed drug class in children. Real-world data mining on the paediatric population showed potential associations between antibiotic use and acute liver injury. Objective: We assessed risk estimates of liver injury associated with antibiotic use in children and adolescent outpatients. Methods: A large, multi-database, population-based, case-control study was performed in people <18 years of age from two European countries (Italy and The Netherlands) during the period 2000–2008. All potential cases of liver injury were automatically extracted from three databases and then manually validated based on Council for International Organizations of Medical Sciences (CIOMS) criteria and by exclusion of all competing causes for liver injury. Up to 100 control participants were sampled for each case and were matched on index date of the event, age, sex and database. Based on prescription data, antibiotic exposure was categorized as current, recent or past use by calculating the time period between the end of prescription and the index date. Multivariate conditional logistic regression analyses were applied to calculate odds ratios (ORs) as a measure of the association (with 95% confidence interval [CI]). Results: We identified 938 cases of liver injury and matched to 93,665 controls. Current use of overall antibiotics is associated with a threefold increased risk of liver injury compared with past use (adjusted OR [ORadj] 3.22, 95% CI 2.57–4.03). With regard to individual antibiotics, the risk is significantly increased for current use of each antibiotic (p < 0.005), except for azithromycin. Risk estimates vary from the lowest ORadj of 1.86 (95% CI 1.08–3.21) for amoxicillin to the highest ORadj of 24.16 (95% CI 11.78–49.54) for cotrimoxazole (i.e. sulphamethoxa

THE VALUE OF DIAGNOSTIC ULTRASOUND FOR DETECTING OCCULT INGUINAL HERNIA IN PATIENTS WITH GROIN PAIN

Aims: chronic groin pain caused by an occult hernia can be a difficult clinical diagnosis and may require additional investiga- tive modalities. The aim of this study was to demonstrate the accuracy of ultrasound in diagnosing occult hernia in patients with recurrent inguinal pain and a negative clinical examination. Patients and methods: over a period of three years, a total of 76 patients were referred for ultrasound examination with clini- cally suspected occult inguinal hernia. Patients with positive US scans were offered surgery, while those with negative US findings were offered further imaging or other diagnostic tests. The ultrasound examination of the inguinal region was conducted using a 5- 10 MHz linear probe. The scan was performed with the patient in the supine and erect positions, in a relaxed state, as well as during coughing and during a Valsalva manoeuvre. Results: overall, ultrasound diagnosed 31 inguinal hernias and all 31 patients with positive scans underwent surgery. Surgery confirmed the ultrasound diagnosis in 30 patients, having only 1/31 no hernia at operation (100% ultrasound sensitivity and 96.9% specificity). Patients undergoing surgery showed complete symptom resolution at a three-month follow-up. Conclusions: this study confirms that ultrasound is capable of accurately diagnosing groin hernia and this may justify its use in patients with chronic groin pain due to a suspected occult herni

THE NUCK'S CYST: A DISEASE EASILY CONFUSED FOR INGUINAL HERNIA. A CASE REPORT.

Nuck's canal cyst is a blind end adult residual of the fetal peritoneum. These rare cyst formations are usually found in the inguinal canal and can easily be mistaken for hernia, or enlarged limph nodes. Clinically, a Nuck's canal cyst appears as a painless or moderately painful swelling in inguinal area. We report the case of a 40 years-old woman with a painless swelling in her left inguinal region, believed a groin hernia but diagnosed as a Nuck's canal cyst only after intervention. Intraoperatively, the cyst was opened and sebsequently excised, closing the abdominal wall without the use of any sort of syntetic prostetic material

Haemodynamics and oxygenation improvement induced by high frequency percussive ventilation in a patient with hypoxia following cardiac surgery: a case report

<p>Abstract</p> <p>Introduction</p> <p>High frequency percussive ventilation is a ventilatory technique that delivers small bursts of high flow respiratory gas into the lungs at high rates. It is classified as a pneumatically powered, pressure-regulated, time-cycled, high-frequency flow interrupter modality of ventilation. High frequency percussive ventilation improves the arterial partial pressure of oxygen with the same positive end expiratory pressure and fractional inspiratory oxygen level as conventional ventilation using a minor mean airway pressure in an open circuit. It reduces the barotraumatic events in a hypoxic patient who has low lung-compliance. To the best of our knowledge, there have been no papers published about this ventilation modality in patients with severe hypoxaemia after cardiac surgery.</p> <p>Case presentation</p> <p>A 75-year-old Caucasian man with an ejection fraction of 27 percent, developed a lung infection with severe hypoxaemia [partial pressure of oxygen/fractional inspiratory oxygen of 90] ten days after cardiac surgery. Conventional ventilation did not improve the gas exchange. He was treated with high frequency percussive ventilation for 12 hours with a low conventional respiratory rate (five per minute). His cardiac output and systemic and pulmonary pressures were monitored.</p> <p>Compared to conventional ventilation, high frequency percussive ventilation gives an improvement of the partial pressure of oxygen from 90 to 190 mmHg with the same fractional inspiratory oxygen and positive end expiratory pressure level. His right ventricular stroke work index was lowered from 19 to seven g-m/m²/beat; his pulmonary vascular resistance index from 267 to 190 dynes•seconds/cm⁵/m²; left ventricular stroke work index from 28 to 16 gm-m/m²/beat; and his pulmonary arterial wedge pressure was lowered from 32 to 24 mmHg with a lower mean airway pressure compared to conventional ventilation. His cardiac index (2.7 L/min/m²) and ejection fraction (27 percent) did not change.</p> <p>Conclusion</p> <p>Although the high frequency percussive ventilation was started ten days after the conventional ventilation, it still improved the gas exchange. The reduction of right ventricular stroke work index, left ventricular stroke work index, pulmonary vascular resistance index and pulmonary arterial wedge pressure is directly related to the lower respiratory mean airway pressure and the consequent afterload reduction.</p