The magnetic \(H\)-\(T\) phase diagram and magnetocaloric effect in the recently discovered high-temperature heavy-fermion compound YbCoC\(_2\) have been studied. With the increase in the external ...magnetic field YbCoC\(_2\) experiences the metamagnetic transition and then transition to the ferromagnetic state. The dependencies of magnetic entropy change -\(\Delta S_m (T)\) have segments with positive and negative magnetocaloric effects for \(\Delta H \leq 6\)~T. For \(\Delta H = 9\)~T magnetocaloric effect becomes positive with a maximum value of -\(\Delta S_m (T)\) is 4.1 J / kg K and a refrigerant capacity is 56.6 J / kg.
Abstract
Background
It has been demonstrated that low operator and institutional volume is associated with poorer procedural and long-term clinical outcomes in general population of patients treated ...with percutaneous coronary interventions (PCI).
Purpose
The aim of the current study was to assess the relationship between operator volume and procedural outcomes of patients treated with PCI within chronic total occlusion (CTO).
Methods
Data for conducting the current analysis were obtained from the national registry of percutaneous coronary interventions (ORPKI) maintained in cooperation with the Association of Cardiovascular Interventions (AISN) of the Polish Cardiac Society. The study covered data obtained from the registry from January 2014 to December 2020. To investigate the association between operator and all periprocedural complications, coronary artery perforation (CAP) and TIMI flow grade 2/3 after PCI in the presence of confounding and clustering effects, we used multivariable, mixed effects logistic regression modelling.
Results
During the investigated period, there were 162 active CathLabs, at which 747,033 PCI procedures were performed during the time of observation. Of those 14,924 were CTO-PCI procedures. Considering the number of CTO-PCIs performed annually by individual operators during the analyzed 7 years we assessed differences between four groups (≤10; >10≤20; >20≤30 and >30 procedures). We demonstrated by nonlinear relationship with annualised CTO-PCI operator volume that operators performing more than 40 PCI with CTO per year have lower number of the overall periprocedural complications (Fig. 1) including CAP, as well greater procedural success rates (Fig. 2) compared to operators performing less procedures (p<0.0001).
Conclusions
High-volume CTO operators achieve a greater procedural success with a lower frequency of periprocedural complications. This study suggests that the cut-off of 50 CTO-PCIs per year recommended in the EuroCTO Consensus remains a reasonable compromise to optimize outcome and maintain local availability. Special CTO training programs and a higher annual case load might increase the overall quality of CTO PCI.
Funding Acknowledgement
Type of funding sources: None.
Background. There has been a significant amount of research on the effects of nicotine on vascular biology; however, little is known about the effects of cotinine, the metabolic product of nicotine. ...This study used a novel vascular perfusion system to study the effects of nicotine and cotinine on the vascular endothelial cell function.
Methods. Porcine common carotid arteries were cultured in a novel vascular perfusion system with nicotine or cotinine or as controls. After 24 h, vessels were precontracted with norepinephrine and subsequently relaxed with acetylcholine. Vessel diameters were recorded and analyzed. After culture, samples were taken for en face, immunohistochemistry, and RT-PCR for eNOS. Porcine coronary arteries were incubated as controls or with nicotine or cotinine and tested on a myograph system to measure contraction and relaxation.
Results. Porcine carotid arteries treated with nicotine and cotinine showed a 27.2% and a 41.2% reduction in endothelial-dependent relaxation, respectively, as compared to control vessels (P < 0.05). Rings of coronary arteries treated with nicotine relaxed similarly to control rings while cotinine-treated rings failed to relax to endothelial-dependent stimulation. RT-PCR for eNOS mRNA showed a 23.2 and a 24.1% reduction in eNOS expression for nicotine- and cotinine-treated vessels, respectively (P < 0.01). Additionally, immunohistochemical staining for eNOS showed less dense staining on nicotine- and cotinine-treated vessels as compared to controls. En face preparations showed normal endothelial cell morphology in all groups, but cell density decreased slightly in vessels treated with nicotine and cotinine.
Conclusion. These results indicate that cotinine may have even more effect on the impairment of endothelial-dependent vasorelaxation than nicotine for the regulation of vessel tone in porcine carotid and coronary arteries.
A muscle-stimulating material made of polyacrylamide gel (PAG) for testing various kinds of hyperthermia applicators was investigated. The permittivity and conductivity dispersion of PAG, as well as ...an internal wavelength and penetration depth, were in good agreement with those of actual muscle at frequencies between 500 MHz and 3 GHz. A single formula for PAG covering three ISM bands, most commonly used for hyperthermia, 433, 915 and 2450 MHz, is presented. The physical properties of the PAG phantom allow any desired form or shape to be moulded, including shapes conforming to the actual geometry of an interstitial or intracavitary applicator. Utilization of a multilayer phantom makes possible the generation of experimental three-dimensional specific absorption rate (SAR) distributions composed from several two-dimensional SAR images at different depths or radial distances from the applicator. Spatial resolution of 1 mm can be achieved. The two-dimensional SAR distributions at different depth values for commercial superficial applicator, an interstitial antenna and a new oesophageal applicator are presented.
Dissociation of a 240 MeV/u beam of 6He, incident on carbon and lead targets, has been studied in kinematically complete experiments to investigate low-lying excitation modes in the halo nucleus 6He. ...It is shown that alignment effects characterize the inelastic scattering and allow an unambiguous assignment of the spin of a narrow resonance observed in the excitation energy spectrum. The differential cross sections for the 6He inelastic scattering on carbon and lead targets were deduced from the measured momenta of the two neutrons and the α-particle. An analysis of these distributions shows that quadrupole and, possibly, monopole excitations characterize the hadronic interaction, while the dipole mode is dominating in Coulomb dissociation. Neither theoretically predicted new resonance states in 6He nor nuclear excitation of a dipole mode were found. Direct evidence has been obtained for strong suppression of Coulomb post-acceleration in direct Coulomb breakup in a lead target.
Peripheral fragmentation of a 240 MeV/nucleon beam of the halo nucleus He-6 incident on carbon target has been studied in a kinematically complete experiment. It is found that one-neutron stripping ...to the unbound nucleus He-5 is the dominant fragmentation mechanism and that it leads to a spin alignment of He-5 in a plane perpendicular to the He-5 momentum vector. This is expected to be a common feature for all neutron halo nuclei.
Momentum distributions and invariant mass spectra from the breakup of He-6 ions with an energy of 240 MeV/u interacting with a carbon target have been studied. The data were used to extract ...information about the reaction mechanism which is influenced by the structure of He-6. It is found that the dominant reaction mechanism is a two-step process: knock out of one neutron followed by the decay of the He-5 resonance. The shape of the (alpha+n) two-body invariant mass spectrum is interpreted as mainly reflecting the 5He ground state which is a J(pi) = 3/2(-) resonance. However, no evidence for correlations between cu particles and neutrons is observed in the momentum widths of the distributions. It is demonstrated that a combined analysis of the two-body invariant mass spectrum and an appropriate correlation function may be used to determine the properties of the intermediate resonance. (C) 1998 Elsevier Science B.V.
N-(4'-pyridoxyl)sphingosine was synthesized and characterized as a stable compound for specialized delivery of a bioactive lipid. It was found to be facilely taken up by hepatocytes although by a ...mechanism more typical for lipids than the one used by natural vitamin B6. Some of the N-(4'-pyridoxyl)sphingosine was metabolically acted upon inside the cell to release pyridoxal 5'-phosphate and sphingosine, but formation of pyridoxal 5'-phosphate from the synthetic compound was poor compared with natural vitamin forms of B6, which may partly be due to entrapment within cell membranes and to constraints at the level of cytosolic pyridoxal kinase which is responsible for phosphorylation of the vitamin. Unlike the parent long-chain base, the B6 conjugate was not particularly cytotoxic. Furthermore, the compound was neither an activator nor inhibitor of the respiratory burst of human neutrophils. These findings identify N-(4'-pyridoxyl)sphingosine as an interesting tool for studies of the cellular transport, metabolism, and functions of both vitamin B6 and sphingosine.
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