Superficial lymph nodes involved by lymphoma in modern gray-scale ultrasound imaging

Background: Clinical evaluation by palpation of superficial lymph nodes involved by lymphoproliferative process is not sufficient. Ultrasound is a useful method of the initial differential diagnosis of lymph nodes. The aim was to assess the spectrum of ultrasound features of superficial lymphomatous nodes and possible diagnostic pitfalls. Material/Methods: Fifty five lymph nodes in 55 patients were prospectively examined in ultrasound with application of blood flow imaging modes and modern imaging techniques. Only forty lymph nodes with histopathologically proven lymphoma were selected for this analysis (3 Hodgkin, 37 non-Hodgkin). Results: 27.5% of the examined lymph nodes were longitudinal; 42.5% had an oval or round shape; 30% were oval-lobulated or lobulated. 32.5% of the nodes did not show an echogenic hilum, 20% had a normal hilum, and 25% - evidently abnormal. 12.5% of the nodes were anechoic. The general ultrasound impression of a reactive lymph node was presented by 37.5% of the lymphomatous nodes; 45% were suspicious. Among 26 patients with non-Hodgkin lymphoma with multiple lymph nodes involved, in 15 (58%) lymph nodes were modeling on each other. Conclusions: Lymphomatous nodes reveal diverse ultrasound presentations: from appearances indistinguishable from benign reactive lymph nodes to features typical of metastases. Ultrasound internal structure of lymphomatous nodes may be anechoic, causing the possibility of confusion with a cyst, especially in case of a single lymphomatous node. Multiple lymphomatous nodes with non-Hodgkin lymphoma often model on each other assuming geometrical shapes

Photo-acoustic response of active biological systems

Two samples from a biologically active system, Trunculariopsis trunculus, were used in thick film form: one damp and the other dry. In both cases intense and broad absorption bands appeared in the visible region of the electromagnetic spectrum near yellow, as well as below 330 nm, attributed to charge transfer transitions. The damp sample produced a higher response signal at about 570 nm. The Photo-acoustic spectra contain all the bands of radiation vital for maintenance of activity in a living system with a distinctive prominence of the yellow part of the spectrum. © 2007 Elsevier B.V. All rights reserved

Thermal characterization of polymer composites with nanocrystalline maghemite

Samples of multiblock poly(ether-ester) copolymer doped with magnetic γFe2O3 nanoparticles (at small concentrations of 0.1 wt. % and 0.3 wt. %) have been investigated by DSC method to study the melting and crystallization behavior. Two forms of magnetic γFe2O 3 nanoparticle filler were used: solid-state grains and a suspension of γFe2O3 with palmitic acid in toluene. Application of the solid filler caused formation of agglomerates of size of about 20 μm while in the suspension form separate nanoparticles were in the range 10-20 run. The thermal and thermo-oxidative stability of composites was analyzed by conventional TGA analysis. The DSC results showed that crystallization and, to a smaller extent, melting, were considerably affected by the introduction of magnetic nanoparticles. The main influence is a shift in the crystallisation temperature up to 20 °C and melting/glass transition shift up to 6 °C. Thermogravimetric analysis showed significant enhancement of thermal and thermo-oxidative stability of the composites with respect to pure PEE. The dependence of thermal parameters on the concentration of magnetic filler has shown that the largest agglomerates produced the biggest change in all thermal parameters

Influence of maghemite concentration on magnetic interactions in maghemite/PTT-block-PTMO nanocomposite

Temperature dependence of dc magnetization and ferromagnetic resonance (FMR) of two samples containing γ-Fe2O3 (maghemite) magnetic nanoparticles dispersed at low concentration (0.1 and 0.3 wt%) in a nanocomposite based on a poly(ether-ester) multiblock copolymer (PTT-block-PTMO) matrix was investigated. The polymer filler was in a powder form consisting of small-sized magnetic nanoparticles arranged in agglomerates 2-3 μm long and 100 nm thick. The studied samples were characterized by SEM spectroscopy. The SEM showed that the concentration of magnetic nanoparticles was homogenous in both samples The temperature dependence of the dc magnetization revealed that the blocking was about 100 K and the ZFC (zero-field cooling) mode at low magnetic fields uncovered the presence of magnetic interactions between magnetic nanoparticles depending on the properties of the matrix. FMR measurements were carried out in the temperature range 4.2-300 K. An intense resonance absorption line attributed to γ-Fe2O3 nanoparticles was recorded with a slightly asymmetric lineshape. At room temperature the resonance line was centered at Hr = 3241(2) and 3253(2) G, with linewidths of ΔH = 1069(1) and 1070(1) G for samples with concentrations of 0.1 and 0.3 wt%, respectively. All FMR parameters showed an anomalous behavior at matrix critical temperatures. It was shown that the difference in concentration of magnetic nanoparticles could be responsible for the observed differences in the thermal behavior of the FMR spectra. © 2008 Elsevier B.V. All rights reserved