Preliminary Study of the Significance of Reverberation by IVUS Detection for Patients With Severe Calcified Lesions

Objectives―To explore the potential significance of the reverberation of calcification by comparing both intravascular ultrasound (IVUS) and optical coherence tomography (OCT) measurement post manual coregistration.Background―The reverberation phenomenon is often detected by IVUS for severe calcified lesions post rotational atherectomy (RA), which is thought to be due to the glassy and smooth inner surfaces of calcifications. Because of the poor penetration of IVUS, it is impossible to measure the thickness of calcifications, and the relationship between multiple reverberations and the thickness of calcification lesions has not been reported before.Methods―A total of forty-nine patients with severe calcified coronary lesions that were detected by IVUS and OCT simultaneously were enrolled in our retrospective study. If reverberation phenomena were detected by IVUS, intravascular imaging (IVI) data (including distance between the IVUS catheter center and the inner surface of the reverberation signal, the intervals between all adjacent reverberation signals, the number of layers of reverberation in IVUS, and the thickness of the calcification in OCT) were measured at the same position and same direction (each cross-section had 4 mutually perpendicular directions) at 1-mm intervals. If the observational point (direction) had a reverberation signal, it was an effective observational point that would be enrolled in our study; otherwise, it would be regarded as an invalid observational point and excluded from this study. The correlation between each reverberation observational value and OCT data was the primary target in this retrospective study. Results―Four hundred twenty-eight valid observational points were analyzed simultaneously by IVUS and OCT; among them, 300 points had a single layer of reverberation, 83 had double layers of reverberation and 42 had multiple layers (≥3 layers) of reverberation by IVUS detection post-RA. Multivariate logistic regression analysis showed that the number of layers of reverberation by IVUS was significantly related to the thickness of calcifications by OCT at the same point and in the same direction (p<0.001). Single, double, and multiple layers of reverberation in IVUS correspond to median calcification thicknesses (interquartile ranges (IQRs)) of 0.620 mm (0.520–0.720), 0.950 mm (0.840–1.040) and 1.185 mm (1.068–1.373), respectively, by OCT detection. No correlation was found between the distance between the IVI catheter center and the inner surface of the reverberation signal or the interval between every adjacent reverberation signal and the thickness of the calcification.Conclusions―The number of layers of reverberation signal detected by IVUS is positively correlated with the thickness of calcifications measured by OCT post-RA.

Bits and Pieces

Covid19-pandemic has had a profound impact on the way we live and on the social reality in the world around us. Except for the enormous strain on public and health of individuals, it has affected social functioning to great extent, at least temporarily. It has sped up digitalization and forced social activities to transfer to the digital realm to an unprecedented level. It has simultaenously confined social actors to their geographical localities. In all of this, it has offered an opportunity of different observational point of human being in the world in the context of late modernity. It is possible to assume that this kind of social situation has the potential to affect the sense of ontological security of social actors, as well as their experience of space. The contradictory implications of the transfer of the social activitiy to the digital communicative spaces to current extent are also discussed.

The Torsional Response of Civil Engineering Structures during Earthquake from an Observational Point of View

This paper discusses the origins of torsion and its effect on the response of structures with a focus on the contribution of experimental data. The fact that torsion increases the stresses in structures, augmenting strain and damage during earthquakes, was confirmed in the 1960s. Over the years, the torsional response of structures has mainly been analysed through numerical studies, because few buildings are equipped with translational sensors, and even fewer are equipped with rotational sensors. This is likely to change as building instrumentation becomes more widespread and new generations of rotational sensors are developed. Therefore, this paper focusses on a number of scientific questions concerning the rotational response of structures during earthquakes and the contribution of experimental data to the understanding of this phenomenon.

Viscous effects in the dark sector of the Universe

Viscous properties are attributed to the dark sector of the Universe. They contribute to the accelerated expansion phase of the Universe and can alleviate existing tensions in the [Formula: see text]CDM model at small scales. We provide a short review of recent efforts on this topic. Different viscous models for the dark sector are analysed both from theoretical and observational point of view.

Placemaking, livability and public spaces. Achieving sustainability through happy places

<p>Livability of places is set by many factors which are in turn influenced by a variety of elements - both tangible and intangible - concerning the area in question and its surroundings. One of these factors is constituted by urban happiness, which, together with the term sustainability meant in its wide meaning, constitutes a key concept in placemaking. In this respect, a new attention to urban happiness has been given but often in terms of theoretical sense or from an observational point of view. Aim of this study is to present the Happy place mapping, a method of analysis specifically devoted to the identification of factors that influence the perception of happiness from the urban point of view. To illustrate the method, the emblematic HafenCity case study carried out in Hamburg is showed. A long process of urban regeneration is interesting this area and the new public spaces are changing the identity of the city, making it more livable and agreeable both for locals and visitors. The discussion on questions related to methods that concern intangible aspects and on Happy place mapping conclude the paper.</p>

Research of blazars at the Astronomical observatory of Belgrade

At the beginning of 2013, we have a team of scientists at the Astronomical Observatory of Belgrade, focusing on observations and research of blazars. At the same time, we established a cooperation with the Astronomical Observatory of Torino (Osservatorio Astrofisico di Torino), center for the Whole Earth Blazar Telescope (WEBT) international collaboration. In this paper, we describe the WEBT project, present our equipment as well as some preliminary results. We also point to some issues that we have encountered during the one year experience and found important from the observational point of view.

Magnetic fields in Proto Planetary Nebulae

The role of magnetic field in late type stars such as proto-planetary and planetary nebulae (PPNe/PNe), is poorly known from an observational point of view. We present submillimetric observations realized with the Submillimeter Array (SMA) which unveil the dust continuum polarization in the envelopes of two well known PPNe: CRL 618 and OH 231.8+4.2. Assuming the current grain alignment theory, we were then able to trace the geometry of the magnetic field.

The Co-Evolution of Supermassive Black Holes and Galaxies: Observational Constraints

The connection between the growth of supermassive black holes (SMBHs) and the assembly of their host galaxies is termed ‘co-evolution’. Understanding co-evolution is one of the most fundamental issues in modern astrophysics. In this contribution, we review recent progress in addressing how the growth of SMBHs is linked to the properties of their host galaxies in the context of galaxy evolution, from the observational point of view. Although a coherent picture has not yet emerged, multiple pathways of co-evolution appear to be favored with a probable dependence on AGN luminosity and redshift.