Recently, several treatments for fighting malignant tumors have been designed. However these procedures have well
known inconveniences, depending on their applicability, tumor size and side effects, among others. Magnetic
hyperthermia is a safe, non-invasive method for cancer therapy. This treatment is applied via elevation of target tissue
temperature by dissipation of heat from Magnetic Nanoparticles (MNPs), previously located within the tumor. The
induction of heat causes cell death and therefore the removal of the tumor.
In this work the thermal diffusion in phantoms of agar loaded with magnetic nanoparticles (MNPs) is studied using the
infrared thermography technique, which is widely used in biology/medicine (e.g. skin temperature mapping). Agar is one
of the materials used to simulate different types of body tissues, these samples are known as “phantoms”. Agar is of
natural origin, low cost and high degree of biocompatibility. In this work the agar gel was embedded with MNPs by coprecipitation
and placed in an alternating magnetic field radiation. As a consequence, the energy from the radiation
source is dissipated as heat and then transferred from the MNP to the gel, increasing its temperature.
For the temperature analysis, the samples of agar gel were stimulated by RF magnetic field generated by coils. Heating
was measured with infrared thermography using a Thermovision A20M infrared camera. Thermographic images allowed
obtaining the dependence of thermal diffusion in the phantom as a function of the magnitude of the applied RF magnetic
field and the load of magnetic particles.
One of the most important subjects of interest in dentistry and teeth preservation is related to the effects of bleaching
agents on the integrity of the dental pieces. This is especially crucial when teeth surface has received some damage,
generated by chemical, biological and mechanical agents or weathering in the case of dental pieces recovered from
burial sites. In this work the time evolution of the effects of bleaching agents on the surface of dental pieces is monitored
using diffuse reflectance in the visible spectrum is reported. The effects were monitored in teeth previously subject to
chemical agents. Bleaching was induced using commercial whitening products. It is shown that the time evolution of the
reflectance depends strongly on the condition of the surface as well as on the thickness of enamel. Additionally the
colorimetric analysis of the samples during the bleaching is presented. This is especially useful in for comparing with
previous studies. In order to complement our studies, the effects of the bleaching on the surface of the teeth were
monitored by scanning electron microscopy.
Non destructive analysis of hydroxyapatite materials is an active research area mainly in the study of dental pieces and
bones due to the importance these pieces have in medicine, archeology, dentistry, forensics and anthropology. Infrared
thermography and photothermal techniques constitute highly valuable tools in those cases. In this work the quantitative
analysis of thermal diffusion in bones is presented. The results obtained using thermographic images are compared with
the ones obtained from the photothermal radiometry. Special emphasis is done in the analysis of samples with previous
thermal damage. Our results show that the treatments induce changes in the physical properties of the samples. These
results could be useful in the identification of the agents that induced modifications of unknown origin in hydroxyapatite
structures.
The analysis of the surface of teeth is an important field of research and technological development due to the
importance of dental pieces in health and aesthetics. The presence of cracks as well as the etching effects on
teeth surface, due to different chemical agents, affects not only the appearance of teeth but its integrity. In this
work, laser thermography analysis of dental pieces with damage in the form of cracks is presented. The technique
consists in the illumination of the surface at the center of the sample, using a 300 mW pulsed solid state laser
beam focused with a gradium lens, and monitoring the spatial and temporal distribution of the temperature
field. The heating of the sample is monitored using a focal plane array infrared camera, sensitive in the spectral
range 7.5-13 μm with a noise equivalent temperature difference of 0.12°C. The data acquisition was performed
by the PC firewire port using a PCI-8254R card and a home-made program in Labview 8.0 was used for data
acquisition. The images were processed in a home-made linux program to obtain the experimental table values.
Our results are compared with position and frequency scans obtained by infrared photothermal radiometry. It
is shown that the crack in the tooth appears as an increase in the photothermal signal. In contrast, the thermographic
image shows a more detailed structure in which close to the crack the temperature increases, but at the
crack the signal falls.
In this work the possibilities of infrared thermography for the study of burned human bones of outstanding
interest in archaeology and anthropology are explored. The technique used consisted in the illumination of the
sample using an infrared solid state laser beam and the observation and the monitoring of the surface temperature
with an infrared camera. The bones analyzed were previously thermally treated in a furnace and boiled
in water. It is shown that the effect of the thermal treatments can be observed in the infrared images, from
which the dynamics of the cooling process of the sample is obtained. It is shown that the cooling process of the
samples could be used to identify the possible burning treatment at which a given material could have undergone
previously. As an auxiliary technique X-ray diffraction was used to analyze the crystallization of the material
and to look for a correlation with different thermal treatments.
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