446 research outputs found
Static and dynamic behavior of multiplex networks under interlink strength variation
It has recently been suggested \cite{Radicchi2013} that in a two-level
multiplex network, a gradual change in the value of the "interlayer" strength
can provoke an abrupt structural transition. The critical point at
which this happens is system-dependent. In this article, we show in a similar
way as in \cite{Garrahan2014} that this is a consequence of the graph Laplacian
formalism used in \cite{Radicchi2013}. We calculate the evolution of as
a function of system size for ER and RR networks. We investigate the behavior
of structural measures and dynamical processes of a two-level system as a
function of , by Monte-Carlo simulations, for simple particle diffusion and
for reaction-diffusion systems. We find that as increases there is a smooth
transition from two separate networks to a single one. We cannot find any
abrupt change in static or dynamic behavior of the underlying system.Comment: 8 pages, 5 figure
Updates in the diagnosis and management of small-bowel Crohn's disease
Crohn's disease (CD) can affect any part of the GI tract, but small bowel (SB) involvement is present in 80% of patients with CD; 30% have exclusive SB disease [1] presenting a diagnostic challenge due to the inaccessibility of standard endoscopic techniques.
Accurate assessment of treatment response [2] and regular monitoring are crucial to prevent surgery and to identify patients at risk of relapse and/or complications before the onset of clinical symptoms [3]. Ileocolonoscopy (IC) is considered the gold standard for evaluating mucosal healing (MH) in CD, but it is invasive and costly [4] and only allows visualization of the terminal ileum (TI). The CALM study has demonstrated that C-reactive protein (CRP) and faecal calprotectin (FCP) can be effective surrogate markers of MH and help guide treatment [5]. Nonetheless, their efficacy is limited [6] as approximately 30% of patients do not present with elevated CRP levels during relapse [7] and the correlation between FCP and active SB disease is weak [8].
Thus, CD requires a multidisciplinary approach. We aim to provide an overview of recent advances in the diagnosis and management of small bowel CD
An unusual pattern of three major components of the cardiovascular system: multimodality imaging and review of the literature
INTRODUCTION: Coronary artery anomalies are found in 0.4% to 1.4% of patients who undergo coronary angiography. Anomalous origin of left coronary artery from the right sinus of Valsava is the rarest, with a reported prevalence of 0.02 –0.03% according to angiographic studies. CASE PRESENTATION: We present the rare case of a 42-year-old-man suffering from stable angina with unusual development of 3 major components of the cardiovascular system Coronary angiography revealed an anomalous origin of the left coronary artery from the ostium of the right coronary artery. Magnetic resonance angiography depicted an anomalous origin of the left common carotid artery from the innominate artery and an aneurysm of descending thoracic aorta. Coronary computed tomography angiography revealed the course of left coronary artery between aortic root and conus arteriosus at the level of the right ventricular outflow tract. In this report we attempt to highlight the rarity of this vascular anatomy. CONCLUSION: Anomalous origins of the coronary arteries are rare, but may cause myocardial ischemia and sudden death. Thus, their reliable identification is a matter of paramount importance possibly evaluating the effects of therapeutic intervention. Newer imaging modalities improve the illumination of vascular system anatomy, shedding light to diagnostic dilemmas that come up in daily medical practice
Investigation of the styloid process length in a Greek population
Background: The styloid process (SP) is a slender cylindrical bony projection of the temporal bone with 2 ligaments and 3 muscles attached to it. Symptomatic SP elongation is also referred to, as Eagle’s syndrome. The aim of the present study is to investigate the distribution of the SP length in a young adult Greek population.
Materials and methods: Moreover, we provide a comparison of the results by using two different methods for assessing SP elongation, as described in the lite- rature. Finally, we explore the possibility of using orthopantomograms (OPGs), as a diagnostic aid by investigating inter-examiner, intra-examiner and inter-exami- nation variability and we propose a limit for SP elongation measurable in OPGs.
Results: The sample comprised 805 digital OPGs, taken from student pilots and engineers entering the Hellenic Air Force Academy, from 2008 onwards. Two measuring approaches were selected, one using the temporal bone, as a cranial landmark and the other, using the external auditory meatus. The end tip of the process was always the caudal landmark. The mean SP length was 28.42 ± ± 8.48 mm in males and 26.04 ± 7.69 mm in females, when measured from the temporal bone. The mean SP length was 38.35 ± 8.90 mm in males and 34.24 ± ± 8.63 mm in females, when measured from the external auditory meatus. The length of 30 mm is most commonly used as a starting point for SP elongation. In the total sample, 30.6% of the measured SPs exceeded the length of 30 mm. In males, 33.12% of the SPs were elongated; while in females the corresponding incidence was 20%. One hundred and nineteen (14.8%) SPs were not traceable.
Conclusions: The SP is typically detectable and measurable in OPGs. An elonga- ted SP should be kept in mind, since symptoms of elongation may overlap with clinical manifestations of temporomandibular joint disorders.
Superficial brachial artery traversing a median nerve loop in the arm associated with other vascular and muscular anomalies: case report and clinical implications
Knowledge of the various morphological patterns of the brachial artery and median nerve in the upper limb area is of considerable clinical and surgical importance to physicians intervening with these areas. In the current study, in the right upper limb of a male cadaver a rare variation of a superficial brachial artery associated with a median nerve loop in the upper arm is presented. The artery gave off a deep brachial artery in the arm and normally bifurcated in the cubital fossa. Additionally, a muscular bundle from the brachialis muscle was also present, overlapping the median nerve along with the deep brachial artery above the elbow. To the best of our knowledge such a combination of arterial, neural and muscular anatomical variations is extremely rare. Since brachial plexus and brachial artery variations are more prone to injury, their surgical, diagnostic and interventional importance are valuable to radiologists in interpreting images and to vascular surgeons, neurosurgeons and orthopedic surgeons involved in compressive peripheral neuropathy treatment. The relevant clinical and surgical implications are discussed as well
Historical considerations regarding the first descriptions of pancreas’ anatomy
The descriptions of the term “pancreas” as well the macroscopic anatomy of the pancreas throughout Antiquity, Byzantium, Middle Ages and Renaissance are displayed. In particular, the original phrases of famous physicians of that period as regards the anatomy of the pancreas are presented: Hippocrates, Aristotle, Herophilus, Galen, Rufus of Efesus, Julius Pollux, Oribasius, Bartolomeo Eustachio, Andreas Vesalius, Gabriel Fallopius, Johann Georg Wirsung, Francis Glisson, Giovanni Domenico Santorini
Ultra-Low-loss Reconfigurable Phase-shifting Metasurface in V band:A Multi-objective Optimization Approach
Future generations of satellite and mobile communications at mm-wave frequencies require the use of low-loss and wideband phase-shifting components. Pixelated metasurfaces provide large design versatility and constitute an attractive solution for wave manipulation, such as shifting the phase of an incident wave. However, their design often implies the simultaneous tuning of a large number of geometrical parameters. This article employs an enhanced multi-objective optimization algorithm to design a dynamically reconfigurable metasurface providing ultra-low losses and linear phase response. The presented methodology can be easily employed for different objective functions or technologies, constituting a versatile design strategy for electromechanically reconfigurable devices based on pixelated metasurfaces. A prototype is fabricated based on the optimization outcome, achieving a phase shifter capable of providing a continuous phase shift up to 180∘ between 50 and 65 GHz. A piezo-electric actuator is used to dynamically adjust the phase shift with respect to the position of a metallic ground plane placed in front of the metasurface. A linear evolution of the phase w.r.t. the ground plane displacement is obtained while maintaining the losses around 1 dB for the whole frequency range
- …