Search results for "Ultra"
showing 10 items of 4451 documents
[Diagnosis, prognosis and treatment of "myocardial bridging": state of the art and unresolved issues].
2013
The current gold standard for the diagnosis of myocardial bridging is conventional coronary angiography; however, it shows only indirect signs of the disease, due to the systolic compression of the artery caused by the myocardial bridge with narrowing of the lumen and diastolic relaxation. On the other hand, computed tomography coronary angiography, even though exposing to radiation, clearly demonstrates the intramural course, the overlying muscular bands and the surrounding tissues also in asymptomatic patients and in absence of systolic compression. The prognosis of patients with myocardial bridge is usually good, but further studies are needed to evaluate the long-term prognosis of these…
Coronary Artery Shape and Flow Changes Induced by Myocardial Bridging.
1993
Changes in coronary shape and blood flow induced by myocardial bridging were analyzed in a 56-year-old patient with symptoms of unstable angina after the exclusion of other heart disease. Coronary angiography demonstrated a 1.8-cm long myocardial bridge in the middle part of the left anterior descending coronary artery. In systole, an eccentric compression of the artery occurred, resulting in a stenosis that occupied 86% of the diameter and 96% of the area. Intraluminal ultrasound was performed with a 20-MHz transducer in a 4.8-Fr catheter sheath (Boston Scientific Corp.) connected to an ultrasound console (Diasonics Inc.). A side saddle catheter was introduced into the left anterior descen…
Derivatization of amphetamine and methamphetamine with 1,2-naphthoquinone 4-sulfonic acid into solid-phase extraction cartridges. Determination of am…
1997
The derivatization of amphetamine and methamphetamine with 1,2-naphthoquinone-4-sulfonate (NQS) into solid-phase extraction cartridges (C 18 ) is described. Optimum conditions were the use of carbonate–hydrogencarbonate buffer of pH 10, a 10 min reaction time at 25 °C and an NQS concentration of 9.6 × 10 - 3 M. The accuracy and the precision of the method were tested. The results obtained with the proposed liquid–solid procedure were compared with those obtained with a traditional liquid–liquid extraction with hexane–ethyl acetate. The procedure was used to measure amphetamine in pharmaceutical and urine samples
Ligand removal from soluble CdTe nanocrystals evidenced by time-resolved photoluminescence spectroscopy
2008
We present experimental studies on the effect of pyridine treatment on the optical properties of ligand-stabilized colloidal CdTe nanocrystals. We demonstrate, by quasi-stationary and time-resolved photoluminescence (PL) spectroscopy, a drastic reduction in the PL lifetime and a concomitant decrease in the PL yield by more than 90% when dissolving the nanocrystals in pyridine. The pyridine solvent efficiently removes the ligand shell and thus enables a rapid energy transfer from the quantum dot to optically dark surface states or into the solvent. The demonstrated removal of the ligand shell is a key step towards integrating such CdTe nanocrystals in hybrid organic/inorganic nanocomposites,…
Room-temperature efficient light detection by amorphous Ge quantum wells
2013
In this work, ultrathin amorphous Ge films (2 to 30 nm in thickness) embedded in SiO2 layers were grown by magnetron sputtering and employed as proficient light sensitizer in photodetector devices. A noteworthy modification of the visible photon absorption is evidenced due to quantum confinement effects which cause both a blueshift (from 0.8 to 1.8 eV) in the bandgap and an enhancement (up to three times) in the optical oscillator strength of confined carriers. The reported quantum confinement effects have been exploited to enhance light detection by Ge quantum wells, as demonstrated by photodetectors with an internal quantum efficiency of 70%. © 2013 Cosentino et al.
Rectal perforation during defecography: extraluminal barium impaction removed by TEM (Transanal Endoscopic Microsurgery).
2016
Defecography is the standard diagnostic technique for the diagnosis of functional disorders of the posterior pelvic compartment. However it has some limits as radiation exposure, low-contrast resolution, some degrees of embarrassment and discomfort for the patients. Furthermore it often fails to directly visualize the changes that affect the pararectal space. Here we present a never described case of rectal perforation after defecography with barium impaction removed by TEM (Transanal Endoscopic Microsurgery).We present a case of a 50 years old woman with extraluminal barium impaction due to perforation occurred during defecography. Both pelvic MR and endoanal ultrasound confirmed the prese…
Ultrasound-assisted extraction for food and environmental samples
2013
Abstract In recent years, ultrasound-assisted extraction (UAE) has attracted growing interest, as it is an effective method for the rapid extraction of a number of compounds from food and environmental samples, with extraction efficiency comparable to that of classical techniques. In particular, recently, numerous analytical applications of this technique dealt with the extraction of natural compounds and pollutants from food and environmental samples. This review gives a brief presentation of the theory of UAE, discusses recent advances that influence its efficiency, and summarizes the main results in selected applications published in the period 2010–12. There is discussion of the advanta…
Feinstruktur der Cheliceren-Dr�se von Nemastoma dentigerum Canestrini (Opiliones, Nemastomatidae)
1973
1. Nemastoma dentigerum Canestrini besitzt als sekundares mannliches Geschlechtsmerkmal eine Apophyse auf dem ersten Chelicerenglied, die eine Druse enthalt. 2. Die einzelnen Drusenzellen schliesen sich jeweils zu Dreiergruppen zusammen, deren distales Ende immer von 3 Hullzellen umfast wird. Diese 6 Zellen bilden eine funktionelle Einheit innerhalb des komplexen Drusenorgans. Jede Drusenzelle gliedert sich in 3 Abschnitte: 1. in den basalen kernhaltigen Teil, 2. in den mittleren sehr langen Drusenzellschlauch und 3. in den distalen Kopf mit Mikrovilli-Becher. 3. An der Sekretion beteiligen sich 2 Zelltypen: die 3 Drusenzellen und die innere Hullzelle (H1). Das Sekret beider Zelltypen gelan…
Ultrastructure, development, and moulting of the aesthetascs of Neomysis integer and Idotea baltica (Crustacea, Malacostraca)
1983
The development of the aesthetascs of Neomysis integer (Malacostraca, Mysidacea) and Idotea baltica (Malacostraca, Isopoda) were investigated by electron microscope methods. Basically the aesthetascs of both species develop according to the same pattern. The newly formed sensillar shafts lie invaginated within the epidermal tissue. They are formed by numerous enveloping cells, which are arranged telescopically one by one. Each enveloping cell secretes a definite portion of the new shaft cuticle. The innermost enveloping cell extends furthest distally and deposits the cuticle of the future shaft tip. The outer enveloping cells produce the cuticle of the more proximal shaft portions. Whereas …
Usefulness of SonoVue in the identification of sentinel nodes in patients with breast cancer
2013
Purpose Methods and Materials Results Conclusion References Personal Information