33 research outputs found

    Snail Trails and Cell Microcrack Impact on PV Module Maximum Power and Energy Production

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    —This paper analyzes the impact of the snail trail phenomena on photovoltaic (PV) module performances and energy production. Several tests (visual inspection, maximum power determination, dielectric withstand, wet leakage current, and electroluminescence test) were carried out on 31 PV modules located in a PV plant in Italy. The electroluminescence test highlighted the strong correlation between the appearance of snail trails and presence of damaged cells in PV modules. The daily energy produced by four PV modules affected by snail trails ranged between 68% and 88% of the energy produced by a damage free commercial PV module over the same period

    Angulation and curvature of aortic landing zone affect implantation depth in transcatheter aortic valve implantation

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    : In transcatheter aortic valve implantation (TAVI), final device position may be affected by device interaction with the whole aortic landing zone (LZ) extending to ascending aorta. We investigated the impact of aortic LZ curvature and angulation on TAVI implantation depth, comparing short-frame balloon-expanding (BE) and long-frame self-expanding (SE) devices. Patients (n = 202) treated with BE or SE devices were matched based on one-to-one propensity score. Primary endpoint was the mismatch between the intended (HPre) and the final (HPost) implantation depth. LZ curvature and angulation were calculated based on the aortic centerline trajectory available from pre-TAVI computed tomography. Total LZ curvature ( kLZ,tot ) and LZ angulation distal to aortic annulus ( αLZ,Distal ) were greater in the SE compared to the BE group (P < 0.001 for both). In the BE group, HPost was significantly higher than HPre at both cusps (P < 0.001). In the SE group, HPost was significantly deeper than HPre only at the left coronary cusp (P = 0.013). At multivariate analysis, αLZ,Distal was the only independent predictor (OR = 1.11, P = 0.002) of deeper final implantation depth with a cut-off value of 17.8°. Aortic LZ curvature and angulation significantly affected final TAVI implantation depth, especially in high stent-frame SE devices reporting, upon complete release, deeper implantation depth with respect to the intended one

    Awake Fiberoptic Intubation Protocols in the Operating Room for Anticipated Difficult Airway: A Systematic Review and Meta-analysis of Randomized Controlled Trials

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    Awake fiberoptic intubation is one of the recommended strategies for surgical patients with anticipated difficult airway, especially when concurrent difficult ventilation is expected. We performed the first systematic review of randomized controlled trials assessing different protocols for awake fiberoptic intubation in anticipated difficult airway, including studies investigating elective awake fiberoptic intubation for scheduled surgery; randomized controlled trials comparing different methods for performing awake fiberoptic intubation; and adult patients with anticipated difficult airway. We excluded studies in the nonoperating theater settings, randomized controlled trials comparing awake fiberoptic intubation with other techniques, and studies based on simulation. Primary outcomes were success rate and death; secondary outcomes were major adverse events. Thirty-seven randomized controlled trials evaluating 2045 patients and 4 areas were identified: premedication, local anesthesia, sedation, and ancillary techniques to facilitate awake fiberoptic intubation. Quality of evidence was moderate-low and based on small-sampled randomized controlled trials. Overall, 12 of 2045 intubation failures (0.59%) and 7 of 2045 severe adverse events (0.34%) occurred, with no permanent consequences or death. All evaluated methods to achieve local anesthesia performed similarly well. No differences were observed in success rate with different sedatives. Dexmedetomidine resulted in fewer desaturation episodes compared to propofol and opioids with or without midazolam (relative risk, 0.51 [95% CI, 0.28-0.95]; P = .03); occurrence of desaturation was similar with remifentanil versus propofol, while incidence of apnoea was lower with sevoflurane versus propofol (relative risk, 0.43 [95% CI, 0.22-0.81]; P = .01). A high degree of efficacy and safety was observed with minimal differences among different protocols; dexmedetomidine might offer a better safety profile compared to other sedatives

    Motion and dosimetric criteria for selecting gating technique for apical lung lesions in magnetic resonance guided radiotherapy

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    IntroductionPatients treatment compliance increases during free-breathing (FB) treatment, taking generally less time and fatigue with respect to deep inspiration breath-hold (DIBH). This study quantifies the gross target volume (GTV) motion on cine-MRI of apical lung lesions undergoing a SBRT in a MR-Linac and supports the patient specific treatment gating pre-selection.Material and methodsA total of 12 patients were retrospectively enrolled in this study. During simulation and treatment fractions, sagittal 0.35 T cine-MRI allows real-time GTV motion tracking. Cine-MRI has been exported, and an in-house developed MATLAB script performed image segmentation for measuring GTV centroid position on cine-MRI frames. Motion measurements were performed during the deep inspiration phase of DIBH patient and during all the session for FB patient. Treatment plans of FB patients were reoptimized using the same cost function, choosing the 3 mm GTV-PTV margin used for DIBH patients instead of the original 5 mm margin, comparing GTV and OARs DVH for the different TP.ResultsGTV centroid motion is <2.2 mm in the antero-posterior and cranio-caudal direction in DIBH. For FB patients, GTV motion is lower than 1.7 mm, and motion during the treatment was always in agreement with the one measured during the simulation. No differences have been observed in GTV coverage between the TP with 3-mm and 5-mm margins. Using a 3-mm margin, the mean reduction in the chest wall and trachea–bronchus Dmax was 2.5 Gy and 3.0 Gy, respectively, and a reduction of 1.0 Gy, 0.6 Gy, and 2.3% in Dmax, Dmean, and V5Gy, respectively, of the homolateral lung and 1.7 Gy in the contralateral lung Dmax.DiscussionsCine-MRI allows to select FB lung patients when GTV motion is <2 mm. The use of narrower PTV margins reduces OARs dose and maintains target coverage

    A Systematic Review and International Web-Based Survey of Randomized Controlled Trials in the Perioperative and Critical Care Setting: Interventions Reducing Mortality

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    The authors aimed to identify interventions documented by randomized controlled trials (RCTs) that reduce mortality in adult critically ill and perioperative patients, followed by a survey of clinicians’ opinions and routine practices to understand the clinicians’ response to such evidence. The authors performed a comprehensive literature review to identify all topics reported to reduce mortality in perioperative and critical care settings according to at least 2 RCTs or to a multicenter RCT or to a single-center RCT plus guidelines. The authors generated position statements that were voted on online by physicians worldwide for agreement, use, and willingness to include in international guidelines. From 262 RCT manuscripts reporting mortality differences in the perioperative and critically ill settings, the authors selected 27 drugs, techniques, and strategies (66 RCTs, most frequently published by the New England Journal of Medicine [13 papers], Lancet [7], and Journal of the American Medical Association [5]) with an agreement ≥67% from over 250 physicians (46 countries). Noninvasive ventilation was the intervention supported by the largest number of RCTs (n = 13). The concordance between agreement and use (a positive answer both to “do you agree” and “do you use”) showed differences between Western and other countries and between anesthesiologists and intensive care unit physicians. The authors identified 27 clinical interventions with randomized evidence of survival benefit and strong clinician support in support of their potential life-saving properties in perioperative and critically ill patients with noninvasive ventilation having the highest level of support. However, clinician views appear affected by specialty and geographical location

    Lunar Gravitational-Wave Antenna

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    Monitoring of vibrational eigenmodes of an elastic body excited by gravitational waves was one of the first concepts proposed for the detection of gravitational waves. At laboratory scale, these experiments became known as resonant-bar detectors first developed by Joseph Weber in the 1960s. Due to the dimensions of these bars, the targeted signal frequencies were in the kHz range. Weber also pointed out that monitoring of vibrations of Earth or Moon could reveal gravitational waves in the mHz band. His Lunar Surface Gravimeter experiment deployed on the Moon by the Apollo 17 crew had a technical failure rendering the data useless. In this article, we revisit the idea and propose a Lunar Gravitational-Wave Antenna (LGWA). We find that LGWA could become an important partner observatory for joint observations with the space-borne, laser-interferometric detector LISA, and at the same time contribute an independent science case due to LGWA's unique features. Technical challenges need to be overcome for the deployment of the experiment, and development of inertial vibration sensor technology lays out a future path for this exciting detector concept.Comment: 29 pages, 17 figure

    Monitoring of Gait Parameters in Post-Stroke Individuals: A Feasibility Study Using RGB-D Sensors

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    Stroke is one of the most significant causes of permanent functional impairment and severe motor disability. Hemiplegia or hemiparesis are common consequences of the acute event, which negatively impacts daily life and requires continuous rehabilitation treatments to favor partial or complete recovery and, consequently, to regain autonomy, independence, and safety in daily activities. Gait impairments are frequent in stroke survivors. The accurate assessment of gait anomalies is therefore crucial and a major focus of neurorehabilitation programs to prevent falls or injuries. This study aims to estimate, using a single RGB-D sensor, gait patterns and parameters on a short walkway. This solution may be suitable for monitoring the improvement or worsening of gait disorders, including in domestic and unsupervised scenarios. For this purpose, some of the most relevant spatiotemporal parameters, estimated by the proposed solution on a cohort of post-stroke individuals, were compared with those estimated by a gold standard system for a simultaneous instrumented 3D gait analysis. Preliminary results indicate good agreement, accuracy, and correlation between the gait parameters estimated by the two systems. This suggests that the proposed solution may be employed as an intermediate tool for gait analysis in environments where gold standard systems are impractical, such as home and ecological settings in real-life contexts

    Radiomics to predict immunotherapy efficacy in advanced renal cell carcinoma: A retrospective study

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    Immunotherapy has become a cornerstone for the treatment of renal cell carcinoma. Nevertheless, some patients are resistant to immune checkpoint inhibitors. The possibility to identify patients who cannot benefit from immunotherapy is a relevant clinical challenge. We analyzed the association between several radiomics features and response to immunotherapy in 53 patients treated with checkpoint inhibitors for advanced renal cell carcinoma. We found that the following features are associated with progression of disease as best tumor response: F_stat.range (p < .0004), F_stat.max (p < .0007), F_stat.var (p < .0016), F_stat.uniformity (p < .0020), F_stat.90thpercentile (p < .0050). Gross tumor volumes characterized by high values of F_stat.var and F_stat.max (greater than 60,000 and greater than 300, respectively) are most likely related to a high risk of progression. Further analyses are warranted to confirm these results. Radiomics, together with other potential predictive factors, such as gut microbiota, genetic features or circulating immune molecules, could allow a personalized treatment for patients with advanced renal cell carcinoma

    Correction to: Tracheal intubation in critically ill patients: a comprehensive systematic review of randomized trials

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    In the publication of this article [1], there was an error in a contributors Family Name. This has now been updated in the original article

    Tracheal intubation in patients at risk for cervical spinal cord injury: A systematic review

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    BACKGROUND Tracheal intubation in patients at risk for secondary spinal cord injury is potentially difficult and risky. OBJECTIVES To compare tracheal intubation techniques in adult patients at risk for secondary cervical spinal cord injury undergoing surgery. Primary outcome was first-attempt failure rate. Secondary outcomes were time to successful intubation and procedure complications. DESIGN Systematic review and meta-analysis of randomized controlled trials (RCTs) with trial sequential analysis (TSA). DATA SOURCES Databases searched up to July 2019. ELIGIBILITY Randomized controlled trials comparing different intubation techniques. RESULTS We included 18 trials enrolling 1972 patients. Four studies used the "awake" approach, but no study compared awake versus non-awake techniques. In remaining 14 RCTs, intubation was performed under general anesthesia. First-attempt failure rate was similar when comparing direct laryngoscopy or fiberoptic bronchoscopy versus other techniques. A better first-attempt failure rate was found with videolaryngoscopy and when pooling all the fiberoptic techniques together. All these results appeared not significant at TSA, suggesting inconclusive evidence. Intubating lighted stylet allowed faster intubation. Postoperative neurological complications were 0.34% (no significant difference among techniques). No life-threatening adverse event was reported; mild local complications were common (19.5%). The certainty of evidence was low to very low mainly due to high imprecision and indirectness. CONCLUSIONS Videolaryngoscopy and fiberoptic-assisted techniques might be associated with higher first-attempt failure rate over controls. However, low to very low certainty of evidence does not allow firm conclusions on the best tracheal intubation in patients at risk for cervical spinal cord injury
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