1,623 research outputs found
Full Phase-Space Analysis of Particle Beam Transport in the Thermal Wave Model
Within the Thermal Wave Model framework a comparison among Wigner function,
Husimi function, and the phase-space distribution given by a particle tracking
code is made for a particle beam travelling through a linear lens with small
aberrations. The results show that the quantum-like approach seems to be very
promising.Comment: 15 pages, plain LaTeX, + 3 uuencoded figures, to be published in
Phys. Lett.
Intramyocardial hemorrhage: An enigma for cardiac MRI?
Cardiovascular magnetic resonance (CMR) is a useful noninvasive technique for determining the presence of microvascular obstruction (MVO) and intramyocardial hemorrhage (IMH), frequently occurring in patients after reperfused myocardial infarction (MI). MVO, or the so-called no-reflow phenomenon, is associated with adverse ventricular remodeling and a poor prognosis during follow-up. Similarly, IMH is considered a severe damage after revascularization by percutaneous primary coronary intervention (PPCI) or fibrinolysis, which represents a worse prognosis. However, the pathophysiology of IMH is not fully understood and imaging modalities might help to better understand that phenomenon. While, during the past decade, several studies examined the distribution patterns of late gadolinium enhancement with different CMR sequences, the standardized CMR protocol for assessment of IMH is not yet well established. The aim of this review is to evaluate the available literature on this issue, with particular regard to CMR sequences. New techniques, such as positron emission tomography/magnetic resonance imaging (PET/MRI), could be useful tools to explore molecular mechanisms of the myocardial infarction healing process
Kinematics signature of a giant planet in the disk of AS 209
[abridged] ALMA observations of dust in protoplanetary disks are revealing
the existence of sub-structures such as rings, gaps and cavities. Such
morphology are expected to be the outcome of dynamical interaction between the
disk and planets. However, other mechanisms are able to produce similar dust
sub-structures. A solution is to look at the perturbation induced by the planet
to the gas surface density and/or to the kinematics. In the case of the disk
around AS 209, a prominent gap has been reported in the surface density of CO
at au. Recently, Bae et al. (2022) detected a localized velocity
perturbation in the CO emission along with a clump in CO
at nearly 200 au, interpreted as a gaseous circumplanetary disk. We
report a new analysis of ALMA archival observations of CO and CO
J=2-1. A clear kinematics perturbation (kink) is detected in multiple channels
and over a wide azimuth range in both dataset. We compared the observed
perturbation with a semi-analytic model of velocity perturbations due to
planet-disk interaction. The observed kink is not consistent with a planet at
200\,au as this would require a low gas disk scale height () in
contradiction with previous estimate ( at au). When
we fix the disk scale height to 0.118 (at au) we find instead that a
planet of 3-5 M at 100 au induces a kinematics perturbation similar
to the observed one. Thus, we conclude that a giant protoplanet orbiting at au is responsible of the large scale kink as well as of the
perturbed dust and gas surface density previously detected. The position angle
of the planet is constrained to be between 60-100. Future
observations with high contrast imaging technique in the near- and mid-
infrared are needed to confirm the presence and position of such a planet.Comment: Accepted by A&
Effects of strategic anthelmintic treatments on the milk production of dairy sheep naturally infected by gastrointestinal strongyles
Neutrophil-tumor cell phagocytosis (cannibalism) in human turoms: an update and literature review
The recognition and removal of apoptotic cells by tissue macrophages and nonprofessional phagocytes, in a process called efferocytosis, is critical for development, tissue homeostasis and resolution of inflammation. Apoptotic bodies arising in tumor tissue are ingested by viable neoplastic cells and by resident macrophages. We described tumor cell phagocytosis of apoptotic neutrophils in human gastric carcinomas. This phenomenon is analogous to neutrophil efferocytosis performed by macrophages and by nonprofessional phagocytes during inflammatory reaction but is distinct by other types of cell-in-cell phenomena including emperipolesis and entosis both cytologically and biologically. In this review, we discussed them in their ultrastructural morphology, physiological roles, and clinicopathologic implications. This article is part of a Special Issue entitled “Apoptosis: Four Decades Later”
Chronic venous insufficiency strengthens the thrombo-embolic risk in congestive heart failure in elderly patients
B anomalies and muon g - 2 from Dark Matter
Motivated by the result of the Muon g-2 experiment and the long-standing anomalies in semileptonic 퐵 meson decays, we systematically build a class of minimal models that can address both experimental results thanks to the contributions of a set of new fields that include a thermal Dark Matter candidate. This talk is mainly based on Refs
X-Shooter study of accretion in Chamaeleon I
DF acknowledges support from the Italian Ministry of Science and Education (MIUR), project SIR (RBSI14ZRHR) and from the ESTEC Faculty Visiting Scientist Programme.We present the analysis of 34 new VLT/X-Shooter spectra of young stellar objects in the Chamaeleon I star-forming region, together with four more spectra of stars in Taurus and two in Chamaeleon II. The broad wavelength coverage and accurate flux calibration of our spectra allow us to estimate stellar and accretion parameters for our targets by fitting the photospheric and accretion continuum emission from the Balmer continuum down to ~700 nm. The dependence of accretion on stellar properties for this sample is consistent with previous results from the literature. The accretion rates for transitional disks are consistent with those of full disks in the same region. The spread of mass accretion rates at any given stellar mass is found to be smaller than inmany studies, but is larger than that derived in the Lupus clouds using similar data and techniques. Differences in the stellar mass range and in the environmental conditions between our sample and that of Lupus may account for the discrepancy in scatter between Chamaeleon I and Lupus.Complete samples in Chamaeleon I and Lupus are needed to determine whether the difference in scatter of accretion rates and the lack of evolutionary trends are not influenced by sample selection.PostprintPeer reviewe
Reproductive factors and the risk of invasive and intraepithelial cervical neoplasia.
The relation between reproductive factors and cervical neoplasia was evaluated in a case-control study of 528 cases of invasive cancer compared with 456 control subjects in hospital for acute conditions unrelated to any of the established or suspected risk factors for cervical cancer, and of 335 cases of cervical intraepithelial neoplasia compared with 262 outpatient controls. The risk of invasive cervical cancer increased with number of livebirths, the estimated multivariate relative risk (RR) being 4.39 in women with five or more births compared with nulliparous women. There was also an inverse relation with age at first livebirth (RR = 0.42 for greater than or equal to 30 vs. less than 20 years) which, however, disappeared after inclusion of parity in multiple logistic regression analysis. Likewise, cases of invasive cervical cancer tended more frequently to report induced abortions. However, this association was not statistically significant after allowance for confounding factors, including parity. No relation emerged with number of spontaneous abortion and age at last pregnancy. When the interaction between parity and sexual habits was analysed, the relative risk increased in subsequent strata of parity with increasing number of sexual partners or decreasing age at first intercourse, thus suggesting an independent effect of sexual and reproductive factors, and hence multiplicative on the relative risk of invasive cervical cancer. No consistent association emerged between the risk of intraepithelial cervical neoplasm and parity, number of abortions and age at first or last birth
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