323,032 research outputs found
Helix breakage during left bundle pacing area implantation
No full textA left bundle pacing stimulation pacemaker was implanted using stylet driver lead. The screw incarceration occurred after positioning of the lead. The screw rupture occurred during lead retraction; the distal portion of the screw remained incarcerated at the interventricular septum. © 2024 Wiley Periodicals LLC
Lumenless and Stylet-Driven Leads for Left Bundle Branch Area Pacing: Materials, Techniques, Benefits, and Trade-Offs of the Two Approaches
No full textLeft bundle branch area pacing (LBBPa) is an innovative technique for physiological pacing. Compared with His bundle pacing, LBBPa provides better pacing thresholds, lower rates of macrodislodgment, and a reliable strategy for cardiac resynchronization. LBBPa traditionally employs lumenless leads (LLL), which are characterized by small lead bodies and a fixed helix design. These features guarantee stability, avoid helix retraction, and facilitate easier septal penetration, all contributing to an advantageous learning curve. On the other hand, stylet-driven pacing leads (SDL) have shown comparable success rates related to lumenless pacing leads, although they carry risks of helix retraction and lead fracture. SDL have been increasingly employed with favorable results, as they provide good maneuverability and support during implantation with continuous monitoring of ECG-paced morphology. Different manufacturers are offering a variety of SDL, and new dedicated tools are being developed to simplify lead implantation. In this review, we examine the procedural techniques, advantages, and limitations of the most commonly used pacing leads and tools for LBBPa, and we summarize the complications associated with both lumenless leads (LLL) and stylet-driven leads (SDL). © 2024 by the authors
High-speed imaging of Strombolian explosions: The ejection velocity of pyroclasts
No full textExplosive volcanic eruptions are defined as the violent ejection of gas and hot fragments from a vent in the Earth's crust. Knowledge of ejection velocity is crucial for understanding and modeling relevant physical processes of an eruption, and yet direct measurements are still a difficult task with largely variable results. Here we apply pioneering high-speed imaging to measure the ejection velocity of pyroclasts from Strombolian explosive eruptions with an unparalleled temporal resolution. Measured supersonic velocities, up to 405 m/s, are twice higher than previously reported for such eruptions. Individual Strombolian explosions include multiple, sub-second-lasting ejection pulses characterized by an exponential decay of velocity. When fitted with an empirical model from shock-tube experiments literature, this decay allows constraining the length of the pressurized gas pockets responsible for the ejection pulses. These results directly impact eruption modeling and related hazard assessment, as well as the interpretation of geophysical signals from monitoring networks. Citation: Taddeucci, J., P. Scarlato, A. Capponi, E. Del Bello, C. Cimarelli, D. M. Palladino, and U. Kueppers (2012), High-speed imaging of Strombolian explosions: The ejection velocity of pyroclasts, Geophys. Res. Lett., 39, L02301, doi:10.1029/2011GL050404
Chondrodermatitis nodularis chronica helicis and photodynamic therapy: a new therapeutic option?
No full textChondrodermatitis nodularis chronica helicis (CNCH) is a fairly frequent disorder of unknown etiology. Although the elective therapy is surgery, local application of topical steroids, antibiotic ointments, intralesional injection of collagen, cryotherapy, curettage followed by diathermy, and CO2 laser treatment have also been proposed. The aim of the study was to test the utility of photodynamic therapy (PDT) for CNCH. Two patients with painful CNCH underwent PDT with a 635 nm light source for 20 minutes (70 J/cm2) after application of cream containing 20% 5-aminolevulinic acid (5-ALA) and occlusion for 3 hours. The lesions decreased considerably in size and pain ceased within a few weeks. The results suggest that this method can be useful for treating CNCH, especially in patients with contraindications for surgery
Cardiac resynchronization therapy with conduction system pacing in a long-term heart transplant recipient: A case report
No full textWe performed cardiac resynchronization therapy by means of conduction system pacing in a heart transplant patient suffering from heart failure with reduced ejection fraction and atrial fibrillation with conduction disturbance (bifascicular block and QRS >160 ms). ECG monitoring showed paroxysmal atrioventricular block. Biventricular pacing was not feasible due to the absence of a suitable coronary sinus branch for pacing. His bundle pacing was performed, and an implantable cardioverter-defibrillator was implanted due to severe left ventricular dysfunction. Cardiac allograft vasculopathy was excluded. During follow-up, the patient's left ventricular function improved, and symptoms allev
Constraints on magma-wall rock thermal interaction during explosive eruptions from textural analysis of cored bombs
No full textCored bombs, a kind of pyroclast consisting of a lithic core surrounded by a chilled shell of juvenile material, record the thermal interaction of magma with wall rocks. We performed textural analysis of cored bombs, solid-melt heat-transfer theoretical modelling, and high-temperature coating experiments to put temporal and intensity constraints on the thermal interaction of potassic magma feeder systems with carbonate wall rocks during explosive eruptions in the Quaternary, Colli Albani Volcanic District (Roman Province). It appears that the degree of thermal alteration of lithic cores records the duration of magma-core heat transfer, whereas the core/shell size ratio records the initial entrainment temperature of the lithic fragment. Both parameters appear to vary significantly with the eruptive style, magnitude and vent location. Specifically, small-scale (similar to 0.1-1 km(3) DRE) hydromagmatic eruptions show magma-core heat-transfer durations of 0.1-10 s and entrainment temperatures in the range of 100-300 degrees C in the case of a monogenetic maar located in the Colli Albani peripheral area, while entrainment temperature is as high as to 800 degrees C for a polygenetic maar in a high-enthalpy geothermal system at the margins of the main Colli Albani magma chamber. A large-scale (similar to 30 km(3) DRE) caldera-forming explosive event shows magma-core heat-transfer duration in the order of 10(2)-10(3)s and temperature of 100-500 degrees C at the initial magma-wall rock contact. On these grounds, we derived the cooling rate of magmas as a function of the initial temperature, mass and size distribution of lithic clasts entrained. Magma cooling by lithic entrainment may have occurred on the same time-scale as that of eruptive pulses (seconds to hours), implying that lithic entrainment may effect changes in magma physico-chemical properties on a short time-scale and, consequently, affect eruptive conduit dynamics. (C) 2010 Elsevier B.V. All rights reserved
Diffusive author(s), cohesive author: Analysis of S/N (1994)
No full textThis study indicates the ways in which various aspects of the author(s) are brought forth in Dumb type’s performance art, the S/N production. Previous research has suggested a non-hierarchical organization of Dumb type and the absence of a “privileged author” in Dumb type’s collaborative work, S/N. However, the results that I have investigated from member’s interviews on the creative process of S/N along with my analysis of the recorded images of S/N, indicate a different aspect of the author(s). First, S/N was created through, so to speak, the collective ideas of the members of Dumb type. Further, S/N has at least nine quotations from previous performances, installations, and printed writings, besides the work-in-progress technique. Explicating one of the “author functions” as given by Michel Foucault, each text has plural subjects of the author. However, it has been revealed from members’ interviews that Teiji Furuhashi had a decision-making role in selecting the members’ ideas within the performance. Since then, S/N has had plural subjects of creation; however, Furuhashi is one of the subjects of creation along with the “privileged author.” S/N has plural authors (diffusive authors) yet at the same time, it has a “privileged author,” Teiji Furuhashi (cohesive author)
Exploring collaborative practices for chronic disease management: Results from a new survey to primary care physicians and specialists in Italy
No full textBackground: Non-communicable diseases (NCDs) represent a global health challenge that requires coordination across various healthcare settings. Purpose: This study in Tuscany, Italy, investigates professional integration between primary care physicians (PCPs) and specialists in NCD management. Research Design: A self-developed survey was used to explore professionals’ views on clinical and organizational collaboration, accountability, and service improvement. Study Sample: The study involved primary care physicians (PCPs) and specialists working in the field of NCD management. Data Collection and/or Analysis: The survey gathered data on professionals' perceptions of clinical protocol use, care integration effectiveness, and other aspects of collaboration in NCD management. Results: Findings reveal disparities between PCPs and specialists in clinical protocol use and care integration effectiveness. Conclusions: The study emphasizes the need to reduce bureaucratic obstacles and enhance information sharing. Promoting peer relationships and innovative performance evaluation tools is vital for improving chronic disease management. This survey contributes valuable insights for the development of integrated care models, aiding healthcare decision-makers in enhancing chronic care system performance
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