New technologies in interventional cardiology

1993 ◽  
Vol 8 (4) ◽  
pp. 637-644 ◽  
Author(s):  
Donald S. Baim
2021 ◽  
Vol 94 (1117) ◽  
pp. 20200774
Author(s):  
Roberto M Sanchez ◽  
Eliseo Vano ◽  
Pablo Salinas ◽  
Nieves Gonzalo ◽  
Javier Escaned ◽  
...  

Objectives: In fluoroscopy-guided interventional practices, new dose reduction systems have proved to be efficient in the reduction of patient doses. However, it is not clear whether this reduction in patient dose is proportionally transferred to operators’ doses. This work investigates the secondary radiation fields produced by two kinds of interventional cardiology units from the same manufacturer with and without dose reduction systems. Methods: Data collected from a large sample of clinical procedures over a 2-year period (more than 5000 procedures and 340,000 radiation events) and the DICOM radiation dose structured reports were analysed. Results: The average cumulative Hp(10) per procedure measured at the C-arm was similar for the standard and the dose reduction systems (452 vs 476 μSv respectively). The events analysis showed that the ratio Hp(10)/KAP at the C-arm was (mean ± SD) 5 ± 2, 10 ± 4, 14 ± 4 and 14 ± 6 μSv·Gy−1·cm−2 for the beams with no added filtration, 0.1, 0.4 and 0.9 mm Cu respectively and suggested that the main cause for the increment of the ratio Hp(10)/KAP vs the “standard system” is the use of higher beam filtration in the “dose reduction” system. Conclusion: Dose reduction systems are beneficial to reduce KAP in patients and their use should be encouraged, but they may not be equally effective to reduce occupational doses. Interventionalists should not overlook their own personal protection when using new technologies with dose reduction systems. Advances in knowledge: Dose reduction technology in interventional systems may increase scatter dose for operators. Personal protection should not be overlooked with dose reduction systems.


1994 ◽  
Vol 9 (4) ◽  
pp. 493
Author(s):  
Andonis G. Violaris ◽  
Patrick W. Serruys

1992 ◽  
Vol 7 (4) ◽  
pp. 634-642 ◽  
Author(s):  
Nicolas A.F. Chronos ◽  
Ulrich Sigwart

Author(s):  
Klaus-Ruediger Peters

Only recently it became possible to expand scanning electron microscopy to low vacuum and atmospheric pressure through the introduction of several new technologies. In principle, only the specimen is provided with a controlled gaseous environment while the optical microscope column is kept at high vacuum. In the specimen chamber, the gas can generate new interactions with i) the probe electrons, ii) the specimen surface, and iii) the specimen-specific signal electrons. The results of these interactions yield new information about specimen surfaces not accessible to conventional high vacuum SEM. Several microscope types are available differing from each other by the maximum available gas pressure and the types of signals which can be used for investigation of specimen properties.Electrical non-conductors can be easily imaged despite charge accumulations at and beneath their surface. At high gas pressures between 10-2 and 2 torr, gas molecules are ionized in the electrical field between the specimen surface and the surrounding microscope parts through signal electrons and, to a certain extent, probe electrons. The gas provides a stable ion flux for a surface charge equalization if sufficient gas ions are provided.


2019 ◽  
Vol 47 (5) ◽  
pp. 1247-1257 ◽  
Author(s):  
Mateusz Dyla ◽  
Sara Basse Hansen ◽  
Poul Nissen ◽  
Magnus Kjaergaard

Abstract P-type ATPases transport ions across biological membranes against concentration gradients and are essential for all cells. They use the energy from ATP hydrolysis to propel large intramolecular movements, which drive vectorial transport of ions. Tight coordination of the motions of the pump is required to couple the two spatially distant processes of ion binding and ATP hydrolysis. Here, we review our current understanding of the structural dynamics of P-type ATPases, focusing primarily on Ca2+ pumps. We integrate different types of information that report on structural dynamics, primarily time-resolved fluorescence experiments including single-molecule Förster resonance energy transfer and molecular dynamics simulations, and interpret them in the framework provided by the numerous crystal structures of sarco/endoplasmic reticulum Ca2+-ATPase. We discuss the challenges in characterizing the dynamics of membrane pumps, and the likely impact of new technologies on the field.


2020 ◽  
Vol 64 (2) ◽  
pp. 251-261
Author(s):  
Jessica E. Fellmeth ◽  
Kim S. McKim

Abstract While many of the proteins involved in the mitotic centromere and kinetochore are conserved in meiosis, they often gain a novel function due to the unique needs of homolog segregation during meiosis I (MI). CENP-C is a critical component of the centromere for kinetochore assembly in mitosis. Recent work, however, has highlighted the unique features of meiotic CENP-C. Centromere establishment and stability require CENP-C loading at the centromere for CENP-A function. Pre-meiotic loading of proteins necessary for homolog recombination as well as cohesion also rely on CENP-C, as do the main scaffolding components of the kinetochore. Much of this work relies on new technologies that enable in vivo analysis of meiosis like never before. Here, we strive to highlight the unique role of this highly conserved centromere protein that loads on to centromeres prior to M-phase onset, but continues to perform critical functions through chromosome segregation. CENP-C is not merely a structural link between the centromere and the kinetochore, but also a functional one joining the processes of early prophase homolog synapsis to late metaphase kinetochore assembly and signaling.


Sign in / Sign up

Export Citation Format

Share Document