This book is a comprehensive reference and practical guide on the technology and application of ultrasound to the musculoskeletal system. It is organized into two main sections. The first is devoted ...to general aspects, while the second provides a systematic overview of the applications of musculoskeletal ultrasound in different areas of the body. Each chapter of the second section provides an introduction on clinical anatomy and the essentials of clinical history and physical examination. Thereafter, performance of the ultrasound study is explained and the normal and pathological anatomy is reviewed. To assist in understanding, the ultrasound scans are correlated with drawings, photographs, images obtained using other modalities, and anatomic specimens. There is a generous complement of high-quality illustrations based on high-end equipment. This book contains a wealth of invaluable information.
Aims. During the bright outburst in 2011, the black hole candidate IGR J17091-3624 exhibited strong quasi-periodic flare-like events (on timescales of tens of seconds) in some characteristic states, ...the so-called heartbeat state. From the theoretical point of view, these oscillations may be modeled by the process of accretion disk instability, driven by the dominant radiation pressure and enhanced heating of the plasma. Although the mean accretion rate in this source is probably below the Eddington limit, the oscillations will still have large amplitudes. As the observations show, the source can exhibit strong wind outflow during the soft state. This wind may help to partially or even completely stabilize the heartbeat. Methods. Using our hydrodynamical code GLADIS, we modeled the evolution of an accretion disk responsible for X-ray emission of the source. We accounted for a variable wind outflow from the disk surface. We examined the data archive from the Chandra and XMM-Newton satellites to find the observed limitations on the wind physical properties, such as its velocity and ionization state. We also investigated the long-term evolution of this source, which lasted over about 600 days of observations, using the data collected by the Swift and RXTE satellites. During this long period, the oscillations pattern and the observable wind properties changed systematically. Results. We found that this source probably exhibits observable outbursts of appropriate timescales and amplitudes as a result of the disk instability. Our model requires a substantial wind component to explain the proper variability pattern, and even complete suppression of flares in some states. The wind mass-loss rate extracted from the data agrees quantitatively well with our scenario.
Pregnancy outcome and uterine fibroids Parazzini, Fabio, MD; Tozzi, Luca, MD; Bianchi, Stefano, MD
Best practice & research. Clinical obstetrics & gynaecology,
07/2016, Volume:
34
Journal Article
Peer reviewed
Myomas are observed in about 3–12% of pregnant women. Uterine fibroids may affect the outcome of pregnancy. The presence of myomas – in particular of myomas that distort the uterine cavity and larger ...intramural myomas – has been associated with infertility. In the case of pregnancy, it has been linked to an increased risk of spontaneous abortion, fetal malpresentation, placenta previa, preterm birth, cesarean section, and peripartum hemorrhage. Although fibroids may negatively affect pregnancy outcome, the impact of their treatment, particularly in quantitative terms, is unclear. Hysteroscopic myomectomy is the treatment of choice for submucous fibroids. The comparative efficacy of laparoscopic, laparotomic, or new modalities of treatment of intramural fibroids is not known. Up to date the choice and modalities of treatment of submucous fibroids should not be based on sound evidence but on clinical concerns and the skill of each center.
The quest for binary and dual supermassive black holes (SMBHs) at the dawn of the multi-messenger era is compelling. Detecting dual active galactic nuclei (AGN) – active SMBHs at projected ...separations larger than several parsecs – and binary AGN – probing the scale where SMBHs are bound in a Keplerian binary – is an observational challenge. The study of AGN pairs (either dual or binary) also represents an overarching theoretical problem in cosmology and astrophysics. The AGN triggering calls for detailed knowledge of the hydrodynamical conditions of gas in the imminent surroundings of the SMBHs and, at the same time, their duality calls for detailed knowledge on how galaxies assemble through major and minor mergers and grow fed by matter along the filaments of the cosmic web. This review describes the techniques used across the electromagnetic spectrum to detect dual and binary AGN candidates and proposes new avenues for their search. The current observational status is compared with the state-of-the-art numerical simulations and models for formation of dual and binary AGN. Binary SMBHs are among the loudest sources of gravitational waves (GWs) in the Universe. The search for a background of GWs at nHz frequencies from inspiralling SMBHs at low redshifts, and the direct detection of signals from their coalescence by the Laser Interferometer Space Antenna in the next decade, make this a theme of major interest for multi-messenger astrophysics. This review discusses the future facilities and observational strategies that are likely to significantly advance this fascinating field.
Abstract Seyfert galaxy NGC 5252 harbors enormously extended ionization cones that have been previously detected in the optical and X-ray band, offering a unique opportunity to investigate the ...interaction between the central active galactic nucleus (AGN) and the surrounding gas in the AGN host galaxy. We present deep Chandra imaging spectroscopy of NGC 5252 with a total exposure time of 230 ks. The morphology in the soft X-rays shows resolved extended structure from the nucleus to a large radial distance, and for the first time we detect the outermost X-ray arc at ∼20 kpc. The X-ray cone mostly follows the direction of the optical ionization cones in the southeast and northwest directions, about 20° misaligned with the major axis of the galactic disk of NGC 5252. Fitting the spectra extracted from radial sectors with photoionization models supports that extended emission is mainly photoionized by the central AGN. We also examine the variation of the photoionization parameter along the radial extension and infer a decreasing ionizing continuum of the central engine by a factor of ∼50 over the past 64,000 yr. These findings are consistent with previous suggestions that NGC 5252 resembles a quasar relic with an M ∼ 10 9 M ⊙ supermassive black hole that went through a minor merger event and switched to a low accretion rate state.
Ultrasonography of fractures in sports medicine Hoffman, Douglas F; Adams, Erik; Bianchi, Stefano
British Journal of Sports Medicine,
02/2015, Volume:
49, Issue:
3
Journal Article, Book Review
Peer reviewed
High-resolution ultrasound is emerging as an important imaging modality in fracture assessment due to its availability, ease of use and multiplanar capabilities. Its usefulness includes injury ...assessment for the presence of a fracture when obtaining radiographs is not immediately available, detecting occult fractures not revealed on radiographs, and diagnosing bone stress injury before radiographic changes. Sonographic evaluation of bone, however, has limitations and should always be coupled with radiographs and possibly advanced imaging modalities such as CT and MR when clinically indicated.
Thickening and elevation of the periosteum from the underlying bone cortex, defined as a periosteal reaction, can be associated with several bone disorders. Although ultrasound (US) has limited ...possibilities in assessing bones, it can depict a periosteal reaction earlier than plain radiography, thus indicating underlying bone disorders. This pictorial essay aims to illustrate the normal and pathologic US appearances of the periosteum in both children and adults. Several disorders are discussed, such as pediatric bone trauma, infections and tumors, as well as trauma, overuse, including medial tibial stress syndrome, and finally certain seronegative spondyloarthropathies in adults. Whenever US depicts a periosteal reaction, a correlation with clinical and laboratory data is mandatory to differentiate different bone disorders. Computed tomography or magnetic resonance imaging must be performed when an infection or a tumor is suspected based on both US and the clinical presentation.
We report the discovery of a luminosity distance estimator using active galactic nuclei (AGNs). We combine the correlation between the X-ray variability amplitude and the black hole (BH) mass with ...the single-epoch spectra BH mass estimates which depend on the AGN luminosity and the line width emitted by the broad-line region. We demonstrate that significant correlations do exist that allow one to predict the AGN (optical or X-ray) luminosity as a function of the AGN X-ray variability and either the H beta or the Pa beta line widths. In the best case, when the Pa beta is used, the relationship has an intrinsic dispersion of ~0.6 dex. Although intrinsically more disperse than supernovae Ia, this relation constitutes an alternative distance indicator potentially able to probe, in an independent way, the expansion history of the universe. With respect to this, we show that the new mission concept Athena should be able to measure the X-ray variability of hundreds of AGNs and then constrain the distance modulus with uncertainties of 0.1 mag up to z ~ 0.6. We also discuss how our estimator has the prospect of becoming a cosmological probe even more sensitive than the current supernovae Ia samples by using a new dedicated wide-field X-ray telescope able to measure the variability of thousands of AGNs.
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