61 research outputs found

    Serpentinite Carbonation for CO2 Sequestration in the Southern Apennines: Preliminary Study

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    Abstract During "Mineral CO2 sequestration" the CO2 is chemically stored in solid carbonates by the carbonations of minerals. The sequestration of CO2 is permanent and safe. Mineral carbonation is an exothermic reaction and occurs naturally in the subsurface as a result of fluid–rock interactions within serpentinite. In situ carbonation aims to promote these reactions by injecting CO2 into porous, subsurface geological formations. In the northern sector of the Pollino Massif (southern Italy) extensively occur serpentinites; they are the subject of a project devoted to their possible use for in situ geological sequestration of CO2

    Hydrogeochemistry and Groundwater Quality Assessment in the High Agri Valley (Southern Italy)

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    The High Agri Valley (southern Italy) is one of the largest intermontane basin of the southern Apennines affected by intensive agricultural and industrial activities. The study of groundwater chemical features provides much important information useful in water resource management. In this study, hydrogeochemical investigations coupled with multivariate statistics, saturation indices, and stable isotope composition (δD and δ18O) were conducted in the High Agri Valley to determine the chemical composition of groundwater and to define the geogenic and anthropogenic influences on groundwater quality. Twenty-four sampling point ( including well and spring waters) have been examined. The isotopic data revealed that groundwater has a meteoric origin. Well waters, located on recent alluvial-lacustrine deposits in shallow porous aquifers at the valley floor, are influenced by seasonal rainfall events and show shallow circuits; conversely, spring waters from fissured and/or karstified aquifers are probably associated to deeper and longer hydrogeological circuits. The R -mode factor analysis shows that three factors explain 94% of the total variance, and F1 represents the combined effect of dolomite and silicate dissolution to explain most water chemistry. In addition, very low contents of trace elements were detected, and their distribution was principally related to natural input. Only two well waters, used for irrigation use, show critical issue for NO3- concentrations, whose values are linked to agricultural activities. Groundwater quality strongly affects the management of water resources, as well as their suitability for domestic, agricultural, and industrial uses. Overall, our results were considered fulfilling the requirements for the inorganic component of the Water Framework Directive and Italian legislation for drinking purposes. The water quality for irrigation is from "good to permissible" to "excellent to good" although salinity and relatively high content of Mg2+ can occasionally be critical

    Mineralogy and heavy metal assessment of the Pietra del Pertusillo reservoir sediments (Southern Italy)

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    The Pietra del Pertusillo freshwater reservoir is a major artificial lake of environmental, biological, and ecological importance located in the Basilicata region, southern Italy. The reservoir arch-gravity dam was completed in 1963 for producing hydroelectric energy and providing water for human use, and nearby there are potential sources of anthropogenic pollution such as urban and industrial activities. For the first time, the minero-chemistry of the lake and fluvio-lacustrine sediments of the reservoir have been evaluated to assess the environmental quality. Moreover, the composition of fluvial sediments derived from the peri-lacual zone of the reservoir and of local outcropping bedrock were also studied to understand the factors affecting the behavior of elements in the freshwater reservoir, with particular attention paid to heavy metals. In Italy, specific regulatory values concerning the element threshold concentration for lake and river sediments do not exist, and for this reason, soil threshold values are considered the standard for sediments of internal waters. The evaluation of the environmental quality of reservoir sediments has been performed using enrichment factors obtained with respect to the average composition of a reconstructed local upper continental crust. We suggest this method as an innovative standard in similar conditions worldwide. In the studied reservoir sediments, the trace elements that may be of some environmental concern are Cr, Cu, Zn, As, and Pb although, at this stage, the distribution of these elements appears to be mostly driven by geogenic processes. However, within the frame of the assessment and the preservation of the quality of aquatic environments, particular attention has to be paid to As (which shows median value of 10 ppm, reaching a maximum value of 26 ppm in Quaternary sediments), constantly enriched in the lacustrine samples and especially in the fine-grained fraction (median = 8.5 ppm)

    Petrography and Geochemistry of the Leucocratic Rocks in the Ophiolites from the Pollino Massif (Southern Italy)

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    In the Tethyan realm, leucocratic rocks were recognized as dikes and layers outcropping in the ophiolitic rocks of the Western Alps, in Corsica, and in the Northern Apennines. Several authors have suggested that the origin of leucocratic rocks is associated with partial melting of cumulate gabbro. Major and trace elements composition and paragenesis provided information about the leucocratic rocks genetic processes. This research aims at disclosing, for the first time, the petrographical and geochemical features of Timpa delle Murge leucocratic rocks, Pollino Massif (southern Italy), in order to discuss their origin and geodynamic significance through a comparison with other Tethyan leucocratic rocks. These rocks are characterized by high amounts of silica with moderate alumina and iron-magnesium contents showing higher potassium contents than plagiogranites, due to plagioclase alteration to sericite. Plagioclase fractionation reflects negative Eu anomalies indicating its derivation from gabbroic crystal mushes. The chondrite normalized REEs patterns suggest the participation of partial melts derived from a metasomatized mantle in a subduction environment. The results reveal some similarities in composition with other Tethyan leucocratic rocks, especially those concerning Corsica and the Northern Alps. These new data provide further clues on the origin of these leucocratic rocks and the Tethyan area geodynamic evolutio

    New diagnostic criteria for metopic ridges and trigonocephaly:a 3D geometric approach

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    Background: Trigonocephaly occurs due to the premature fusion of the metopic suture, leading to a triangular forehead and hypotelorism. This condition often requires surgical correction for morphological and functional indications. Metopic ridges also originate from premature metopic closure but are only associated with mid-frontal bulging; their surgical correction is rarely required. Differential diagnosis between these two conditions can be challenging, especially in minor trigonocephaly. Methods: Two hundred seven scans of patients with trigonocephaly (90), metopic rigdes (27), and controls (90) were collected. Geometric morphometrics were used to quantify skull and orbital morphology as well as the interfrontal angle and the cephalic index. An innovative method was developed to automatically compute the frontal curvature along the metopic suture. Different machine-learning algorithms were tested to assess the predictive power of morphological data in terms of classification. Results: We showed that control patients, trigonocephaly and metopic rigdes have distinctive skull and orbital shapes. The 3D frontal curvature enabled a clear discrimination between groups (sensitivity and specificity &gt; 92%). Furthermore, we reached an accuracy of 100% in group discrimination when combining 6 univariate measures. Conclusion: Two diagnostic tools were proposed and demonstrated to be successful in assisting differential diagnosis for patients with trigonocephaly or metopic ridges. Further clinical assessments are required to validate the practical clinical relevance of these tools.</p

    New diagnostic criteria for metopic ridges and trigonocephaly:a 3D geometric approach

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    Background: Trigonocephaly occurs due to the premature fusion of the metopic suture, leading to a triangular forehead and hypotelorism. This condition often requires surgical correction for morphological and functional indications. Metopic ridges also originate from premature metopic closure but are only associated with mid-frontal bulging; their surgical correction is rarely required. Differential diagnosis between these two conditions can be challenging, especially in minor trigonocephaly. Methods: Two hundred seven scans of patients with trigonocephaly (90), metopic rigdes (27), and controls (90) were collected. Geometric morphometrics were used to quantify skull and orbital morphology as well as the interfrontal angle and the cephalic index. An innovative method was developed to automatically compute the frontal curvature along the metopic suture. Different machine-learning algorithms were tested to assess the predictive power of morphological data in terms of classification. Results: We showed that control patients, trigonocephaly and metopic rigdes have distinctive skull and orbital shapes. The 3D frontal curvature enabled a clear discrimination between groups (sensitivity and specificity &gt; 92%). Furthermore, we reached an accuracy of 100% in group discrimination when combining 6 univariate measures. Conclusion: Two diagnostic tools were proposed and demonstrated to be successful in assisting differential diagnosis for patients with trigonocephaly or metopic ridges. Further clinical assessments are required to validate the practical clinical relevance of these tools.</p

    Comparison of Internal and External Distraction in Frontofacial Monobloc Advancement:A Three-Dimensional Quantification

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    Background: Crouzon syndrome is characterized by complex craniosynostosis and midfacial hypoplasia. Where frontofacial monobloc advancement (FFMBA) is indicated, the method of distraction used to achieve advancement holds an element of equipoise. This two-center retrospective cohort study quantifies the movements produced by internal or external distraction methods used for FFMBA. Using shape analysis, this study evaluates whether the different distraction forces cause plastic deformity of the frontofacial segment, producing distinct morphologic outcomes. Methods: Patients with Crouzon syndrome who underwent FFMBA with internal distraction [HĂ´pital Necker-Enfants Malades (Paris, France)] or external distraction [Great Ormond Street Hospital for Children (London, United Kingdom)] were compared. Digital Imaging and Communications in Medicine files of preoperative and postoperative computed tomographic scans were converted to three-dimensional bone meshes and skeletal movements were assessed using nonrigid iterative closest point registration. Displacements were visualized using color maps and statistical analysis of the vectors was undertaken. Results: Fifty-one patients met the strict inclusion criteria. Twenty-five underwent FFMBA with external distraction and 26 with internal distraction. External distraction provides a preferential midfacial advancement, whereas internal distractors produce a more positive movement at the lateral orbital rim. This confers good orbital protection but does not advance the central midface to the same extent. Vector analysis confirmed this to be statistically significant (P &lt; 0.01). Conclusions: Morphologic changes resulting from monobloc surgery differ depending on the distraction technique used. Although the relative merits of internal and external distraction still stand, it may be that external distraction is more suited to addressing the midfacial biconcavity seen in syndromic craniosynostosis. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, III.</p

    Experienced Use of Dexmedetomidine in the Intensive Care Unit: A Report of a Structured Consensus

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    OBJECTIVE: Management of pain, agitation and delirium (PAD) remains to be a true challenge in critically ill patients. The pharmacological proprieties of dexmedetomidine (DEX) make it an ideal candidate drug for light and cooperative sedation, but many practical questions remain unanswered. This structured consensus from 17 intensivists well experienced on PAD management and DEX use provides indications for the appropriate use of DEX in clinical practice. METHODS: A modified RAND/UCLA appropriateness method was used. In four predefined patient populations, the clinical scenarios do not properly cope by the current recommended pharmacological strategies (except DEX), and the possible advantages of DEX use were identified and voted for agreement, after reviewing literature data. RESULTS: Three scenarios in medical patients, five scenarios in patients with acute respiratory failure undergoing non-invasive ventilation, three scenarios in patients with cardiac surgery in the early postoperative period and three scenarios in patients with overt delirium were identified as challenging with the current PAD strategies. In these scenarios, the use of DEX was voted as potentially useful by most of the panellists owing to its specific pharmacological characteristics, such as conservation of cognitive function, lack of effects on the respiratory drive, low induction of delirium and analgesia effects. CONCLUSION: DEX might be considered as a first-line sedative in different scenarios even though conclusive data on its benefits are still lacking

    A European multicenter outcome study on the different perioperative airway management policies following midface surgery in syndromic craniosynostosis:a proposal for a Standard Operating Procedure

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    BACKGROUND: Perioperative airway management following midface advancements in children with Apert and Crouzon/Pfeiffer syndrome can be challenging, and protocols often differ. This study examined airway management following midface advancements and postoperative respiratory complications.METHODS: A multicenter, retrospective cohort study was performed to obtain information about the timing of extubation, perioperative airway management, and respiratory complications after monobloc / le Fort III procedures.RESULTS: Ultimately, 275 patients (129 monobloc and 146 Le Fort III) were included; 62 received immediate extubation and 162 delayed extubation; 42 had long-term tracheostomies and nine perioperative short-term tracheostomies. Short-term tracheostomies were in most centers reserved for selected cases. Patients with delayed extubation remained intubated for three days (IQR 2 - 5). The rate of no or only oxygen support after extubation was comparable between patients with immediate and delayed extubation, 58/62 (94%) and 137/162 (85%) patients, respectively. However, patients with immediate extubation developed less postoperative pneumonia than those with delayed, 0/62 (0%) versus 24/161 (15%) (P = 0.001), respectively. Immediate extubation also appeared safe in moderate/severe OSA since 19/20 (95%) required either no or only oxygen support after extubation. The odds of developing intubation-related complications increased by 21% with every extra day of intubation.CONCLUSIONS: Immediate extubation following midface advancements was found to be a safe option, as it was not associated with respiratory insufficiency but did lead to fewer complications. Immediate extubation should be considered routine management in patients with no/mild OSA and should be the aim in moderate/severe OSA after careful assessment.</p

    A European multicenter outcome study on the different perioperative airway management policies following midface surgery in syndromic craniosynostosis:a proposal for a Standard Operating Procedure

    Get PDF
    BACKGROUND: Perioperative airway management following midface advancements in children with Apert and Crouzon/Pfeiffer syndrome can be challenging, and protocols often differ. This study examined airway management following midface advancements and postoperative respiratory complications.METHODS: A multicenter, retrospective cohort study was performed to obtain information about the timing of extubation, perioperative airway management, and respiratory complications after monobloc / le Fort III procedures.RESULTS: Ultimately, 275 patients (129 monobloc and 146 Le Fort III) were included; 62 received immediate extubation and 162 delayed extubation; 42 had long-term tracheostomies and nine perioperative short-term tracheostomies. Short-term tracheostomies were in most centers reserved for selected cases. Patients with delayed extubation remained intubated for three days (IQR 2 - 5). The rate of no or only oxygen support after extubation was comparable between patients with immediate and delayed extubation, 58/62 (94%) and 137/162 (85%) patients, respectively. However, patients with immediate extubation developed less postoperative pneumonia than those with delayed, 0/62 (0%) versus 24/161 (15%) (P = 0.001), respectively. Immediate extubation also appeared safe in moderate/severe OSA since 19/20 (95%) required either no or only oxygen support after extubation. The odds of developing intubation-related complications increased by 21% with every extra day of intubation.CONCLUSIONS: Immediate extubation following midface advancements was found to be a safe option, as it was not associated with respiratory insufficiency but did lead to fewer complications. Immediate extubation should be considered routine management in patients with no/mild OSA and should be the aim in moderate/severe OSA after careful assessment.</p
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