Synchrotron-based XRD from rat bone of different age groups.

Synchrotron-based XRD spectra from rat bone of different age groups (w, 56 w and 78w), lumber vertebra at early stages of bone formation, Calcium hydroxyapatite (HAp) [Ca10(PO4)6(OH)2] bone fill with varying composition (60% and 70%) and bone cream (35-48%), has been acquired with 15keV synchrotron X-rays. Experiments were performed at Desy, Hamburg, Germany, utilizing the Resonant and Diffraction beamline (P9), with 15keV X-rays (λ=0.82666 A0). Diffraction data were quantitatively analyzed using the Rietveld refinement approach, which allowed us to characterize the structure of these samples in their early stages. Hydroxyapatite, received considerable attention in medical and materials sciences, since these materials are the hard tissues, such as bone and teeth. Higher bioactivity of these samples gained reasonable interest for biological application and for bone tissue repair in oral surgery and orthopedics. The results obtained from these samples, such as phase data, crystalline size of the phases, as well as the degree of crystallinity, confirm the apatite family crystallizing in a hexagonal system, space group P63/m with the lattice parameters of a=9.4328Å and c=6.8842Å (JCPDS card #09-0432). Synchrotron-based XRD patterns are relatively sharp and well resolved and can be attributed to the hexagonal crystal form of hydroxyapatite. All the samples were examined with scanning electron microscope at an accelerating voltage of 15kV. The presence of large globules of different sizes is observed, in small age groups of the rat bone (8w) and lumber vertebra (LV), as distinguished from, large age groups (56 and 78w) in all samples with different magnification, reflects an amorphous phase without significant traces of crystalline phases. Scanning electron microscopy (SEM) was used to characterize the morphology and crystalline properties of Hap, for all the samples, from 2 to 100µm resolution.

[Experimental study on the influence of natural and artificial ventilation on indoor radon concentration]. / Studio sperimentale sull'influenza della ventilazione naturale e artificiale sulla concentrazione di radon indoor.

The study presents the results of a campaign of measurements on the daily radon concentration using a Genitron Alpha Guard spectrometer. All the measurements have been intended to highlight the radon concentration variability during the 24 hours of the day and trying to find correlations with other ambient parameters such as temperature and pressure or local conditions such as the presence or not of a forced ventilation system. The main part of the measurements have been carried in the area of the Nuclear Measurement Laboratory of the Department of Basic and Applied Sciences for Engineering of "Sapienza" University of Rome. Results show a rapid rise of radon concentration in the night, when the artificial ventilation system was off and with door and windows closed. In the morning, after the opening of door and windows, the concentration falls down abruptly. With artificial ventilation system in function concentration never reaches significant values.

Investigation of the distribution of elements in snail shell with the use of synchrotron-based, micro-beam X-ray fluorescence spectrometry.

In this study, synchrotron-based micro-beam was utilized for elemental mapping of a small animal shell. A thin X-ray spot of the order of approximately 10microm was focused on the sample. With this spatial resolution and high flux throughput, the X-ray fluorescent intensities for Ca, Mn, Fe, Ni, Zn, Cr and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive HpGe detector. The sample is scanned in a 'step-and-repeat' mode for fast elemental mapping and generated elemental maps at 8, 10 and 12keV. All images are of 10microm resolution and the measurement time was 1s per point. The accumulation of trace elements was investigated from the soft-tissue in small areas. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other trace elements.

A comparative study for the development of a thermal odoscope for the wearable dynamic thermography monitoring.

BACKGROUND: The need of the reliable continuous monitoring of temperature is rising in many clinical applications. Today the use of thermography has become central for instance in the analysis of breast cancer, for the survey of inflammatory processes and certain skin areas during physical exercise. The core of the problem is the development of an ad hoc instrument, because traditional methodologies such as infrared and liquid crystals are no longer suitable. MATERIAL AND METHODS: We developed a dedicated simulation set-up using Matlab R12 procedures (The Mathworks, USA) and P-spice models (Interlink, USA). We simulated the realisation and use of three different equipment configurations for thermography, one based on PTC sensors, another on thermocouples, a third one on specific integrated silicon components. We also bench tested one prototype. RESULTS: The results showed the feasibility of the realisation of the instrument and the validity of the data obtained by means of the simulation.

A new kernel method for microcalcification detection: Spin Glass-Markov Random Fields.

Mammography associated with clinical breast examination is the only effective method for mass breast screening. Microcalcifications are one of the primary signs for early detection of breast cancer. In this paper we propose a new kernel method for classification of difficult-to-diagnose regions in mammographic images. It consists of a novel class of Markov Random Fields, using techniques developed within the context of statistical mechanics. This method is used for the classification of positive Region of Interest (ROI's) containing clustered microcalcifications and negative ROI's containing normal tissue. The obtained results show that the proposed approach can be successfully employed for detection of microcalcifications

Toward a quantitative analysis of skin lesion images.

Melanoma is the most dangerous form of skin cancer. Skin cancers, and particularly melanomas, can be easily cured if detected early. The regularity of the pigment network structure is a significant sign for early diagnosis of melanoma. We present here a quantitative analysis of the morphology of the pigment network structure. Our method is based on the extraction of the pigment network structure using digital image processing techniques. Once the network is extracted, it is possible to derive statistical indicators relative to its regularity or irregularity. We report experiments on a database of 14 images, showing the effectiveness of our method.

Analysis of periapical lesion using statistical textural features.

In this work we present a quantitative study on different regions of periapical images with a series of textural features, extracted using cooccurrence matrices; those features are used for a pattern recognition analysis by means of an artificial neural network. The obtained results show that it is possible to recognize in an objective way changes in bone pattern.

Comparison of different excitation methods for X-ray spectral analysis: the case of synchrotron radiation.

Different excitation means, protons, photons and electrons (PIXE, XRFA, and EPMA, respectively) have previously been compared with regard to the figures of merit, i.e. detection power, precision and accuracy. The aim in this article is to compare synchrotron radiation SR as another excitation method with the methods mentioned above. From this point of view the evaluation of (SR) was missing as an again independently optimized excitation method and was based as previously on practical problems of trace analysis, in this case on the determinations of traces in lead. The experiment has been performed with thick homogeneous samples of lead, the same samples already used in the former work, so that a direct comparison is possible. The calculation of the figures of merit is based on the measurements of the blank values and their relative standard deviation for the detection limit and on the random errors for the precision. Regarding the thick homogeneous target of lead XRFA still turns out to be the best method, whereas Synchrotron X-Ray Fluorescence SY-XRF compares favorably, at least for larger atomic numbers Z. Even PIXE is inferior to (SY-XRF) in the case of larger Z; when information on the lateral distribution of the elements is of interest, PIXE is indispensable.

Mitogen dose-dependent effect of weak pulsed electromagnetic field on lymphocyte blastogenesis.

The effects of pulsed extremely low frequency electromagnetic fields on human peripheral blood lymphocyte mitogenesis induced by phytohaemoagglutinin, concanavalin A or calcium ionophore A23187 were studied. The dependence of the field effect on mitogen concentrations was investigated. Field exposure produced strong inhibition of DNA synthesis when optimal doses of mitogens were used, confirming our previous findings. Opposite effects were observed at suboptimal concentration of mitogens. Experiments performed by exposing cell cultures to the field for short periods indicated that a field application of at least 6 h is needed to influence irreversibly lymphocyte blastogenesis.

A large-angle coherent/Compton scattering method for measurement in vitro of trabecular bone mineral concentration.

In this paper, experiments and related theoretical deductions on coherent/Compton scattering of 59.5-keV Am241 gamma line by bonelike materials are described. In particular, we demonstrate that a photon scattering mineralometer (PSM) can attain the best working conditions when it operates in a backscattering geometry mode. In fact, the large scattering angle we chose, theta = 135 degrees, allowed us to assemble a very compact source-detector device. Further, the relative sensitivity at 135 degrees turns out to be congruent to 1.7 and congruent to 6 times bigger than at 90 degrees and 45 degrees, respectively. The performances of the theta = 135 degrees PSM we assembled were experimentally investigated; i.e., in a measuring time of 10(3) s, a congruent to 5% statistical precision for bonelike materials, such as K2HPO4-water solutions, was obtained. The large-angle PSM device seems therefore to be very promising for trabecular bone mineral density measurements in vivo in peripheral anatomic sites.

A role for Ca2+ in the effect of very low frequency electromagnetic field on the blastogenesis of human lymphocytes.

The DNA synthesis of lymphocytes triggered by phytohemagglutinin or phorbol-myristate-acetate is strongly reduced by the externally applied electromagnetic field (ELF). Ca2+ uptake by stimulated lymphocytes is also reduced by ELF. The effect appears to be synergistic with that of the well-known calcium blocker agent, verapamil.

Reduced mitogenic stimulation of human lymphocytes by extremely low frequency electromagnetic fields.

Blastogenesis of human peripheral blood lymphocytes stimulated in vitro by non-specific mitogens (PHA, ConA, PWM) upon exposure to extremely low frequency EMF has been studied. Different frequencies of square waveforms have been used. PHA-stimulation resulted in strong inhibitions as measured by [3H]thymidine incorporation. A frequency window (3-50 Hz) within which ConA-induced blastogenesis was significantly inhibited has been individuated. The mitogenic effect of PWM was significantly affected only at 3 Hz.

[Analytical findings in the X-ray fluorescence of blood levels of bromine in subjects anesthetized with halothane]. / Indagine analitica mediante tecnica x.r.f. sui livelli ematici di bromo in soggetti sottoposti ad anestesia con halothano.

Bromine concentration in the blood of seven patients anesthetized with Halothane are determined at different time before, during and after anesthetic induction. X.R.F. technique was employed in the analytical determinations using a new background correction method which assume a linear relationship between primary Compton in matrix of monocromathic source radiation and background counts. Mini mun Detectable Limits are of - 5 p.p.m. and accuracy of 3% at 20-30 p.p.m. concentration. 24 h after anesthesia Bromine levels are always significantly high (-20 p.p.m.); the clinical importance of these data are discussed.

[Calcium content of KMnO4 induced granuloma after treatment with 2 combined non-steroidal drugs: indomethacin plus diflunisal]. / Contenuto di calcio in granulomi indotti da KMnO4 dopo trattamento con associazione di due farmaci non steroidei: indometacina e diflunisal.

In this work the authors are concerned with the study of different amounts of calcium in granulomas induced by permanganate and treated with Indomethacin only or with Indomethacin plus Diflunisal. Less calcium was found in granulomas of animals treated with Indomethacin plus Diflunisal.

Calcium content of experimental granuloma as determined by X-ray fluorescence. Influence of non-steroid antiinflammatory drugs.

The deposit of calcium in experimental granulomas as determined by X-ray fluorescence is notably decreased by orally given indomethacin and diflunisal.

Radioisotope X-ray fluorescence technique in the study of joint inflammation.

An X-ray fluorescence technique was employed to study the clearance rate from the knee joint of an intraarticularly injected stable tracer. Clearance curves, determined in two normal volunteers and in three patients with various articular diseases, were found to be of the monoexponential type in agreement with results obtained by authors employing radioactive tracers. Clearance half-time values in basal conditions were higher in the normal knee joint than in the inflamed knee joint. The effect of a corticosteroid suspension injected into the knee joint was also studied. Preliminary results obtained indicate that the X-ray fluorescence technique can be employed, with some advantages compared with the radiotracer technique, for quantitative determination of spontaneous or pharmacologically induced changes in joint inflammation.