233 research outputs found

    Crystal chemistry of barian titanian phlogopite from a lamprophyre of the gargano promontory (Apulia, Southern Italy)

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    This study is focused on a barian titanian phlogopite found in an alkaline ultramafic dyke transecting Mesozoic limestones of the Gargano Promontory (Apulia, Italy). The rock containing the barian titanian phlogopite, an olivine-clinopyroxene-rich lamprophyre with nepheline and free of feldspars, has been classified as monchiquite. The present study combines chemical analyses, single crystal X-ray diffraction and Raman spectroscopy. Chemical variations suggest that the entry of Ba into the phlogopite structure can be explained by the exchange Ba + Al = K + Si. The crystal structure refinement indicates that the Ti uptake is consistent with the Ti–oxy exchange mechanism. The structural parameters associated with the oxy substitution mechanism are extremely enhanced and rarely reported in natural phlogopite: (a) displacement of M2 cation toward the O4 site (~0.7); (b) M2 octahedron bond-length distortion (~2.5); (c) very short c cell parameter (~10.14 Å). Raman analysis showed most prominent features in the 800–200 cm−1 region with the strongest peaks occurring at 773 and 735 cm−1. Only a weak, broad band was observed to occur in the OH-stretching region. As concerns the origin of the barian titanian phlogopite, the rock textural features clearly indicate that it crystallized from pockets of the interstitial melt. Here, Ba and Ti enrichment took place after major crystallization of olivine under fast-cooling conditions, close to the dyke margin

    HP-LT metamorphism in Elba Island: Implications for the geodynamic evolution of the inner Northern Apennines (Italy)

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    The inner Northern Apennines belt (i.e., northern Tyrrhenian Sea and Tuscany) is an Alpine chain affectedby high-P metamorphic conditions during its evolution. Although Elba Island is structurally located closeto the Adria-Europe suture zone, for several authors it represents a sector of the orogen affected bylow-P metamorphism. The involvement of Elba Island tectonic units in high-P metamorphism was onlysuspected for the sparse presence of phengitic white mica in the metasedimentary rocks. This paperpresents the first clear evidence of high-P and low-T metamorphism found in metabasite rocks embed-ded in the Cretaceous calcschist of eastern Elba Island. Mineral composition of metabasite includesGln + Cpx + Ep + Ab + Act + Qtz + Ilm ± Ti-oxide ± Spn and is indicative of a former equilibration in the epi-dote blueschist subfacies and subsequent retrogression in the greenschist facies. Recorded metamorphicconditions are P = 0.9–1.0 GPa and T = 330–350◦C. Tectonic discrimination using immobile elements inthe metabasite does not point to an oceanic setting. As a consequence, the metasedimentary succes-sion containing metabasite is explained as belonging to the Tuscan continental domain and not to theLigurian-Piedmont Ocean, as previously interpreted. Our results have two significant implications: (i)it is confirmed and strengthened that the tectonic stacking of the Elba Island units did not occur in alow-pressure context; (ii) Elba Island is now completely reconciled in the tectonic and metamorphicevolution of the inner Northern Apennines

    Late Palaeozoic tectonics in Central Mediterranean: a reappraisal

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    A revision of late Palaeozoic tectonics recorded in Tuscany, Calabria and Corsica is here presented. We propose that, in Tuscany, upper Carboniferous-Permian shallow-marine to continental sedimentary basins, characterized by unconformities and abrupt changes in sedimentary facies, coal-measures, red fanglomerate deposits and felsic magmatism, may be related with a transtensional setting where upper-crustal splay faults are linked with a mid-crustal shear zone. The remnants of the latter can be found in the deep-well logs of Pontremoli and Larderello-Travale in northern and southern Tuscany respectively. In Calabria (Sila, Serre and Aspromonte), a continuous pre-Mesozoic crustal section is exposed, where the lower-crustal portion mainly includes granulites and migmatitic paragneisses, together with subordinate marbles and metabasites. The mid-crustal section, up to 13 km-thick, includes granitoids, tonalitic to granitic in composition, emplaced between 306 and 295 Ma. They were progressively deformed during retrograde extensional shearing, with a final magmatic activity, between 295 ± 1 and 277 ± 1 Ma, when shallower dykes were emplaced in a transtensional regime. The section is completed by an upper crustal portion, mainly formed by a Palaeozoic sedimentary succession deformed as a low-grade fold and thrust belt, and locally overlaying mediumgrade paragneiss units. As a whole, these features are reminiscent of the nappe zone domains of the Sardinia Variscan Orogen. In Corsica, besides the well-known effusive and intrusive Permian magmatism of the “Autochthonous” domain, the Alpine Santa Lucia Nappe exposes a kilometer-scale portion of the Permian lower to mid-crust, exhibiting many similarities to the Ivrea Zone. The distinct Mafic and Granitic complexes characterizing this crustal domain are juxtaposed through an oblique-slip shear zone named Santa Lucia Shear Zone. Structural and petrological data witness the interaction between magmatism, metamorphism and retrograde shearing during Permian, in a temperature range of c. 800–400 °C. We frame the outlined paleotectonic domains within a regional-scale, strain–partitioned, tectonic setting controlled by a first-order transcurrent/transtensional fault network that includes a westernmost fault (Santa Lucia Fault) and an easternmost one (East Tuscan Fault), with intervening crustal domains affected by extensional to transtensional deformation. As a whole, our revision allows new suggestions for a better understanding of the tectonic framework and evolution of the Central Mediterranean during the late Palaeozoic

    Permeability and hydraulic condictivity of faulted micashist in the Eastern Elba Island exhumed geothermal system (Tyrrhenian sea, Italy): insights from Cala Stagnone

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    Estimating values of permeability (k), ef cient porosity (P) and hydraulic conductivity (K) by analysing eld outcrops as analogue of geothermal reservoirs, is a timely theme useful for predictions during geothermal ex- ploration programs. In this paper we present a methodology providing k, P and K values, based on geomet- ric analysis of quartz-tourmaline faults-vein arrays hosted in micaschist exposed in south-eastern Elba Island (Tuscan Archipelago, Italy), considered as the analogue of rock hosting the so-called “deep reservoir” in the Larderello geothermal eld. The methodology is based on the integration among structural geology, uid inclu- sions results and numerical analyses. Through a detailed structural mapping, scan-lines and scan-boxes analy- ses, we have reconstructed three superposed faulting events, developed in an extensional setting and framed in the Neogene evolution of inner Northern Apennines. Geometrical data of the fault-veins array were processed by reviewing the basic parallel-plate-model-equation for k evaluation. Fluid inclusion analyses provided those salinity and pressure-temperature values necessary for de ning density and viscosity of the parent geothermal uids. Then, permeability, density and viscosity were joined to get hydraulic conductivity (K). Permeability is estimated between 5 × 10− 13 and 5 × 10− 17 m2 with variations among the different generation of faults, while the hydraulic conductivity is encompassed between 1.31 × 10− 8 and 2.4 × 10− 13 m/s. The obtained permeabil- ity and hydraulic conductivity values are comparable with those from several geothermal areas, and in particular from the Larderello geothermal eld. The main conclusion is that the proposed integrated approach provides a reliable methodology to obtain crucial values, normally obtained after drilling, for developing numerical ow models of geothermal uid path in active geothermal systems by eld and laboratory analyses of analogue, ex- humed, geothermal systems

    Healthcare professionals’ perspectives on the use of PCSK9 inhibitors in cardiovascular disease: an in-depth qualitative study

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    Aims Injectable medicines such as PCSK9 inhibitors are increasingly used to manage risk factors for cardiovascular events with little information around the perceptions of healthcare professionals (HCPs) on the administrative and clinical practicalities. The aim was to identify the facilitators and barriers on the use of injectable therapies with cardiovascular benefits through interviews with HCPs.Methods and results Qualitative interviews were conducted in the UK (London and Leeds) and Italy (Rome and Milan) in 2021. Coding was undertaken using NVivo and thematic analysis performed. A total of 38 HCPs were interviewed, 19 in each country composing of physicians (n = 18), pharmacists (n = 10), nurses (n = 9), and pharmacy technician (n = 1). Four themes emerged: (i) clinicians' previous experiences with injectable therapies, (ii) challenges with patients' behaviours and beliefs, (iii) clinicians' knowledge of injectable therapies and therapeutic inertia, and (iv) organizational and governance issues. The behaviour and beliefs from HCPs focused on facilitating behaviour change as well as the poor interdisciplinary working and collaboration. Therapeutic inertia was raised where physicians either lacked awareness of injectable therapies or were unwilling to prescribe them. The importance of facilitating patient education on injection techniques was highlighted, while organizational and governance issues identified the lack of guidance to inform practice. Clear pathways are required to identify those who were eligible for injectable therapies as well as on how injectables should be prescribed.Conclusion If medicine optimization is to be achieved, there need to be structured processes in place to identify eligible patients and the development of educational material.Graphical Abstrac

    Patients' perceptions on the facilitators and barriers using injectable therapies in dyslipidaemia: An empirical qualitative descriptive international study

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    Background: Injectable medicines are increasingly used to manage abnormal levels of lipids, which is a major risk factor for cardiovascular events. Enhancing our understanding of patients' perceptions of these injectables, can inform practice with the aim of increasing uptake and medication adherence. Aim: To explore patient's experiences of using injectables and to identify potential facilitators and barriers to using injectable therapies in dyslipidaemia. Design: A qualitative descriptive study using semi-structured interviews was conducted with patients who were using injectables to manage their cardiovascular conditions. Methods: A total of 56 patients, 30 from the United Kingdom and 26 from Italy, were interviewed online from November 2020 to June 2021. Interviews were transcribed and schematic content analysis performed. Results: Four distinct themes emerged from interviews with patients and caregivers: (i) Their behaviours and personal beliefs; (ii) Knowledge and education about injectable medication; (iii) Clinical skills and previous experiences and (iv) Organizational and governance. Participants expressed initial fears such as needle phobia, and their concerns about commencing therapy were compounded by a lack of accessible information. However, patients' pre-existing knowledge of lipid lowering medication, previous experience with statins and history of adverse side effects informed their decision-making regarding using injectables. Organization and governance-related issues were primarily around the distribution and management of medication supply within primary care, and the lack of a standardized clinical support monitoring system. Conclusion: Changes are needed in clinical practice to better educate and support patients to improve the uptake of injectables and optimize their use of these medications in the management of dyslipidaemia. Impact: This study suggests that injectable therapies were acceptable to people with cardiovascular disease. However, healthcare professionals need to play a key role in improving education and providing support to aid patients' decision-making regarding commencing and adhering to injectable therapies. Reporting method: The study adhered to the Consolidated Criteria for Reporting Qualitative Research. Patient or public contribution: There was no patient or public contribution

    Effectiveness of motivational interviewing on health-service use and mortality: a secondary outcome analysis of the MOTIVATE-HF trial

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    Aims Intense health-care service use and high mortality are common in heart failure (HF) patients. This secondary analysis of the MOTIVATE-HF trial investigates the effectiveness of motivational interviewing (MI) in reducing health-care service use (e.g. emergency service use and hospitalizations) and all-cause mortality.Methods and results This study used a randomized controlled trial. Patients and caregivers were randomized to Arm 1 (MI for patients), Arm 2 (MI for patients and caregivers), or Arm 3 (control group). Data were collected at baseline and at 3, 6, 9, and 12 months. Face-to-face MI plus three telephone calls were performed in Arms 1 and 2. The sample consisted of 510 patient (median age 74 years, 58% male patients) and caregiver dyads (median age 55 years, 75% female patients). At 12 months, 16.1%, 17%, and 11.2% of patients used health-care services at least once in Arms 1, 2, and 3, respectively, without significant difference. At 3 months, 1.9%, 0.6%, and 5.1% of patients died in Arms 1, 2, and 3, respectively. Mortality was lower in Arm 2 vs. Arm 3 at 3 months [hazard ratio (HR) = 0.112, 95% CI: 0.014-0.882, P = 0.04]; no difference was found at subsequent follow-ups. Mortality was lower in Arm 1 vs. Arm 3 at 3 months but did not reach statistical significance (HR = 0.38, 95% CI: 0.104-1.414, P = 0.15).Conclusion This study suggests that MI reduces mortality in patients with HF if caregivers are included in the intervention. Further studies with a stronger intervention and longer follow-up are needed to clarify the benefits of MI on health-care service use and mortality

    The relationship between caregiver contribution to self-care and patient quality of life in heart failure: A longitudinal mediation analysis

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    Background: Patients with heart failure may experience poor quality of life due to a variety of physical and psychological symptoms. Quality of life can improve if patients adhere to consistent self-care behaviors. Patient outcomes (i.e., quality of life) are thought to improve as a result of caregiver contribution to self-care. However, uncertainty exists on whether these outcomes improve as a direct result of caregiver contribution to self-care or whether this improvement occurs indirectly through the improvement of patient heart failure self-care behaviors. Aims: To investigate the influence of caregiver contribution to self-care on quality of life of heart failure people and explore whether patient self-care behaviors mediate such a relationship. Methods: This is a secondary analysis of the MOTIVATE-HF randomized controlled trial (Clinicaltrials.gov registration number: NCT02894502). Data were collected at baseline and 3 months. An autoregressive longitudinal path analysis model was conducted to test our hypotheses. Results: We enrolled a sample of 510 caregivers [mean age = 54 (±15.44), 24% males)] and 510 patients [mean age = 72.4 (±12.28), 58% males)]. Patient self-care had a significant and direct effect on quality of life at three months (β = 0.20, p < .01). Caregiver contribution to self-care showed a significant direct effect on patient self-care (β = 0.32, p < .01), and an indirect effect on patient quality of life through the mediation of patient self-care (β = 0.07, p < .001). Conclusion: Patient quality of life is influenced by self-care both directly and indirectly, through the mediation of caregiver contribution to self-care. These findings improve our understanding on how caregiver contribution to self-care improves patient outcomes
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