909 research outputs found
Diagnostic Value of Prenatal MR Imaging in the Detection of Brain Malformations in Fetuses before the 26th Week of Gestational Age
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Rare-earth doped glasses and light managing in solar cells
Glasses doped with rare earth elements possess unique photoluminescence properties. They find application in several devices, such as lasers, optical amplifiers, and sensors. More recently, rare-earth doped glass thin films have been the subject of investigation for the development of frequency-converting layers able to increase the efficiency of silicon solar cells. Another approach to the improvement of the performance of a solar cell is based on the capture of a larger flux of light by the detector, which can be obtained by surface texture, plasmonics, or waveguide structures. Here, the recent advances in this area will be briefly reviewed
Imaging of a Case of Extramedullary Solitary Plasmacytoma of the Trachea
We describe a case of
extramedullary tracheal plasmacytoma that was
incidentally discovered in a 73-year-old man on a PET
scan performed for assessing the extent of colon
cancer. CT scan showed the tumor; multiplanar
reformation coupled with virtual bronchoscopy allowed
proper treatment planning. The tracheal tumor was
resected during rigid bronchoscopy. Relevant
investigations excluded multiple myeloma. Follow-up CT
showed persistent thickening of the tracheal wall, but
there has been no recurrence after one-year
followup
Variability of Forebrain Commissures in Callosal Agenesis: A Prenatal MR Imaging Study
BACKGROUND AND PURPOSE: Agenesis of the corpus callosum, even when isolated, may be characterized by anatomic variability. The aim of this study was to describe the types of other forebrain commissures in a large cohort of randomly enrolled fetuses with apparently isolated agenesis of the corpus callosum at prenatal MR imaging. MATERIALS AND METHODS: All fetuses with apparent isolated agenesis of the corpus callosum undergoing prenatal MR imaging from 2004 to 2014, were evaluated for the presence of the anterior or a vestigial hippocampal commissure assessed in consensus by 2 pediatric neuroradiologists. RESULTS: Overall, 62 cases of agenesis of the corpus callosum were retrieved from our data base. In 3/62 fetuses (4.8%), no forebrain commissure was visible at prenatal MR imaging, 23/62 fetuses (37.1%) presented with only the anterior commissure, and 20/62 fetuses (32.3%) showed both the anterior commissure and a residual vestigial hippocampal commissure, whereas in the remaining 16/62 fetuses (25.8%), a hybrid structure merging a residual vestigial hippocampal commissure and a rudiment of the corpus callosum body was detectable. Postnatal MR imaging, when available, confirmed prenatal forebrain commissure findings. CONCLUSIONS: Most fetuses with apparent isolated agenesis of the corpus callosum showed at least 1 forebrain commissure at prenatal MR imaging, and approximately half of fetuses also had a second commissure: a vestigial hippocampal commissure or a hybrid made of a hippocampal commissure and a rudimentary corpus callosum body. Whether such variability is the result of different genotypes and whether it may have any impact on the long-term neurodevelopmental outcome remains to be assessed. AC : anterior commissure ACC : agenesis of the corpus callosum CC : corpus callosum GA : gestational age HC : hippocampal commissure HS : hybrid structur
Magnetodielectric coupling of a polar organic-inorganic hybrid Cr(II) phosphonate
Cr[(H(3)N-(CH(2))(2)-PO(3))(Cl)(H(2)O)] represents a rare example of a polar organic-inorganic hybrid material that exhibits a canted antiferromagnetic order below T(N)=5.5 K. The unusual coexistence of a polar crystal structure and magnetic order triggered our investigation of the magnetodielectric coupling. The coupling is evidenced by an anomaly in the temperature dependence of the dielectric constant epsilon below the Neel temperature. The magnetocapacitance is enhanced by one order of magnitude below T(N). The main characteristics of the magnetodielectic response are interpreted by Landau theoretical coupling terms
Ground deformation and associated hazards in NW peloponnese (Greece)
In the last decades, ground deformations were investigated, analysed and monitored using several methods. As a consequence of a spreading urbanization, several phenomena, e.g. landslide and subsidence, were emphasized or triggered causing not only socio-economic damages, but, in some cases, also casualties. The investigation and mapping of these phenomena are important for both local authorities and civil protection in order to promote a higher conscientious urban planning and to highlight the more hazardous areas. Furthermore, the information are a key point for social development connected to the awareness of the environment and the related risk. The Achaia prefecture, in the north-eastern Peloponnese (Greece), close to the Gulf of Patras, is an area strongly affected by subsidence and landslides. Furthermore, this is an earthquake-prone area, a factor that can trigger some mass movements. For this region, a landslide inventory was realized with the help of the interpretation of Persistent Scatterers data, for the period 1992–2008, and high-resolution optical satellite images, available until 2016, in addition to the investigation of the landslide State of Activity. Moreover, for the coastal area, a section was investigated to evidence subsidence
Nickel(II) 3,4;9,10-Perylenediimide bis-Phosphonate Pentahydrate: A Metal−Organic Ferromagnetic Dye
The new metal−organic compound nickel(II) 3,4;9,10-
perylenediimide bis-phosphonate pentahydrate, i.e. Ni2[(PDI-BP)-
(H2O)2]·3H2O (1), has been synthesized and its structural and magnetic
properties have been studied. Reaction of 3,4;9,10-perylenediimide bisphosphonate
(PDI-BP, hereafter) ligand and nickel chloride in water resulted
in the precipitation of a red and poorly crystalline solid (1). As the solid shows
a poor crystalline organization of aggregates, the energy dispersive X-ray
diffraction analysis (EDXD) technique has been used to obtain short-range
order structural information of the single nanoaggregates by radial distribution
function analysis. The overall structure of the compound is characterized by
layers containing perylene planes shifted in the direction perpendicular to the
stacking axes in such a way that only the outer rings overlap. The edges of the
perylene planes are connected to the phosphonate groups through an imido
group. The oxygen atoms of the [−PO3]2‑ group and those of the water
molecules are bonded to the nickel ions resulting in a [NiO6] octahedral coordination sphere. The Ni−O bond lengths are 0.21
± 0.08 nm and the Ni−O−Ni angles of aligned moieties are 95 ± 2°. The oxygen atoms of the water molecules and the nickel
atoms are nearly planar and almost perpendicular to the perylene planes forming chains of edge-sharing octahedra. The magnetic
properties of (1) show the presence of intrachain ferromagnetic Ni−Ni interactions and a long-range ferromagnetic order below
21 K with a canting angle and with a spin glasslike behavior due to disorder in the inorganic layer. Hysteresis cycles show a
coercive field of ca. 272 mT at 2 K that decreases as the temperature is increased and vanishes at ca. 20 K
Medullary sponge kidney: unusual finding in kidney transplant recipient
Background: Medullary sponge kidney is generally considered a benign condition, gold standard for the diagnosis is urography but it has almost been replaced by UroCT that did not present the same sensibility. Although it is really rare, our sonography's findings were consistent with medullary sponge kidney in the transplanted kidneys.Case presentation: A 45-year-old woman with a long history of double-kidney transplantation complained of frequent urinary tract infections, a history of vague loin pain and came to our attention for sonography follow-up. Her kidney function was normal, we did not find signs of infections in the transplanted kidneys and urinary findings were normal. Curiously, the transplanted kidneys came from a newborn and the patient received a double-kidney transplantation in order to guarantee a satisfactory renal function.Conclusions: Despite a long history of kidney transplantation, genetic disease should not be forgotten when symptoms and images recall to specific inherited alterations. Sonography has to be considered in diagnostic path of kidney cystic disease
Prenatal Brain MR Imaging: Reference Linear Biometric Centiles between 20 and 24 Gestational Weeks
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