Evaluation of the efficacy of foam sclerosant after addition of glycerine on human great saphenous vein: histological and immunohistochemical study.

INTRODUCTION: Several treatment modalities have been postulated to improve the efficacy of varicose vein treatment. Addition of glycerine to the sclerosing material has been documented to increase its viscosity and subsequently prolong the duration of stability, in addition to the direct sclerosing effect of glycerine. This histological and immunohistochemical study investigated the efficacy of addition of glycerine 72% to sclerotherapy on the human varicose vein. METHODS: After surgical stripping of great saphenous veins, three equal segments were resected between two clamps. Specimen 1 was injected with saline only, specimen 2 was exposed to foam sclerosant 2%, and specimen 3 was exposed to a mixture of foam sclerosant 2% and glycerine 72%. All segments were left for 5min. Vein segments were then processed for histological and immunohistochemical study. RESULTS: Microscopically, haematoxylin and eosin-stained specimen 1 showed endothelial swelling, cytoplasmic eosinophilia and pyknotic nuclei. The media showed sarcoplasm vacuolisation and necrosis. Specimen 3 showed hypereosinophilic sarcoplasm of the smooth muscle fibres. Oedema was less evident, with a relative decrease in the thickness of the wall compared with specimen 2. Immunohistochemically, the expression of smooth muscle actin was weak in specimen 3 compared with specimens 1 and 2. Expression of CD31 antibody was much reduced in specimen 2 which showed conserved islands of endothelial cells. By contrast, there was a complete loss of endothelial cells in specimen 3. CONCLUSION: Addition of glycerine 72% to foam sclerosant has a more damaging effect on human vein wall.

A new method for measurement of moisture transport in porous media based on forward and backward scattering of epithermal neutrons.

We present a new method for determining the spatial distribution and transport of water in porous media. It is based on the detection of both forward and backward scattered neutrons from the wet regions of the samples under investigation. The experimental set-up is based on a Pu-Be neutron source and He-3 neutron detector assemblies. The results obtained showed that back scattered neutrons are more sensitive than the forward scattered neutrons to determine water content. Moreover, both forward and back scattered neutrons are more sensitive than either back or forward neutrons for determining water content. The method was used to measure moisture transport in sand columns and brick samples. Forward and backward scattered neutrons from different wet regions along the water flow path (x) are recorded as the sample absorbs water. Water saturates the regions of the samples tested near the inlet of water faster than the others. The water front positions were found to follow the square root behavior of the absorption time, and capillary penetration coefficients were determined for the samples investigated. The developed method can be used to investigate water absorption at various flow rates in porous samples of various sizes.

Extracorporeal shock wave lithotripsy for distal ureteric stones: which is the ideal approach?

OBJECTIVE: To compare the safety and efficacy of different approaches using ESWL for management of distal ureteric stone in an attempt to select the ideal one. PATIENTS AND METHODS: This is a prospective randomized single-center study conducted on patients with lower third single radiopaque ureteric stone with size less than 15 mm. Patients were randomized into three groups, group A: Supine transgluteal, group B: Modified prone and group C: Prone position (80 patients each). The success of the procedure was assessed by NCCT and is defined as complete stone removal or had only clinically insignificant fragments (< 3 mm) for a maximum of three sessions. The success rate, rate of complications, pain intensity by visual pain scale and patients' satisfaction rate were compared among the three study groups. RESULTS: Data of 240 patients were analyzed (80 in each group). Overall, no significant difference has been observed among all groups regarding demographic data, stone and treatment characteristics. The overall success rates for treatment after the last session were 86.3%, 65% and 62.5% in the three study groups, respectively, with a statistically significant difference for group A. Regarding pain perception and complication rate, all groups were comparable. Patient satisfaction is significantly better in group A versus the other two groups. CONCLUSION: Our study has confirmed better efficacy profile and patients' satisfaction rate of ESWL in the supine position (transgluteal approach) than other different known approaches for the treatment of distal ureteral stones.

Determination of moisture distributions in porous building bricks by neutron radiography.

Water transport into construction building materials is an important subject since it may deteriorate them because it can carry harmful biological and chemical substances. Some of the reported results in literature for moisture transport in construction building materials follow Fick's law of diffusion while others show anomalous diffusion. There is not enough reliable and accurate data in the literature to discuss this issue. Therefore, in the present work moisture transport into four different kinds of brick samples was studied using the real time neutron radiography method. Neutron radiography images were registered continuously during the moisture absorption process. Simple procedures based on the Cd-umbrella method were used for the first time to correct for the neutron scattering during the water absorption process. The images showed clearly that the absorption process is different from one sample to another. The water content distribution along the flow direction, x (profiles) and positions of water front as the time of moisture absorption elapses were determined from the images obtained. The results obtained showed that the water front positions do not scale with the square root of the absorption time. It was shown that moisture diffusion processes in the samples investigated could be described by an anomalous diffusion approach of the sub-diffusive type. The moisture diffusivities were determined for every sample. The neutron radiography method and the neutron scattering correction procedures used are proven to be a powerful and effective for studying transport process in porous media.

A method for measuring macroscopic cross-sections for thermal neutrons.

A method was proposed for measuring macroscopic absorption and scattering cross-sections for thermal neutrons. It is based on a Pu-Be neutron source and He-3 neutron detectors assembly. A beam of neutrons was obtained from the source imbedded in a water tank. The He-3 detectors oriented inside the sample and at 180° and 0° with respect to the incident neutron beam were used to register neutrons after interaction with the samples. Neutron count rates (detectors responses) were obtained for large (5.5l) as well as small (1.3l) volumes of standard samples. Sensitivities of the results obtained for the large and small samples were compared. A semi-empirical model was proposed to fit the results. It describes the relative detector responses in terms of a dimensionless variable which depends on the geometrical parameters and cross section of the standard samples used. The model successfully fits the results obtained. Advantages and limitations of the method were discussed.

A method for moisture measurement in porous media based on epithermal neutron scattering.

A method for moisture measurement in porous media was proposed. A wide beam of epithermal neutrons was obtained from a Pu-Be neutron source immersed in a cylinder made of paraffin wax. (3)He detectors (four or six) arranged in the backward direction of the incident beam were used to record scattered neutrons from investigated samples. Experiments of water absorption into clay and silicate bricks, and a sand column were investigated by neutron scattering. While the samples were absorbing water, scattered neutrons were recorded from fixed positions along the water flow direction. It was observed that, at these positions scattered neutrons increase as the water uptake increases. Obtained results are discussed in terms of the theory of macroscopic flow in porous media. It was shown that, the water absorption processes were Fickian and non Fickian in the sand column and brick samples, respectively. The advantages of applying the proposed method to study fast as well as slow flow processes in porous media are discussed.

A method for determination mass absorption coefficient of gamma rays by Compton scattering.

A method was proposed for determination mass absorption coefficient of gamma rays for compounds, alloys and mixtures. It is based on simulating interaction processes of gamma rays with target elements having atomic numbers from Z=1 to Z=92 using the MCSHAPE software. Intensities of Compton scattered gamma rays at saturation thicknesses and at a scattering angle of 90° were calculated for incident gamma rays of different energies. The obtained results showed that the intensity of Compton scattered gamma rays at saturations and mass absorption coefficients can be described by mathematical formulas. These were used to determine mass absorption coefficients for compound, alloys and mixtures with the knowledge of their Compton scattered intensities. The method was tested by calculating mass absorption coefficients for some compounds, alloys and mixtures. There is a good agreement between obtained results and calculated ones using WinXom software. The advantages and limitations of the method were discussed.

Experimental determination of moisture distributions in fired clay brick using a 252Cf source: a neutron transmission study.

A neutron transmission method was proposed to study liquid transport in porous media. It was applied to study water penetration into two kinds of fired clay bricks. The results showed that the diffusion processes in the investigated samples are different. Water diffusivities and capillary absorption coefficients characterizing both the flow process and the brick samples were determined and compared. The proposed method is simple, accurate and reliable in studying water diffusion in porous media, in real time.

Measurement of the fission neutron spectrum averaged cross sections for the 95Mo(n, p)95Nb, 92Mo(n, alpha)89Zr, 90Zr(n, 2n)89Zr and 60Ni(n, p)60Co reactions.

The average cross-sections in a fission-type reactor neutron spectrum are determined experimentally for the reactions: (92)Mo (n, a) (89)Zr, (90)Zr (n, 2n) (89)Zr and (60)Ni (n, p) (60)Co. The determined cross sections are in the ranges of the reported values in literature. A method for determining the cross sections in relative way is introduced. It replaces the cross sections and the nuclear data by a composite nuclear data constant which can be calculated and determined experimentally. It is shown that the uncertainties of determining these constants experimentally are mainly lower than the calculated ones. The consequences of using this constant in neutron activation analysis are briefly discussed.

Neutron radiography determination of water diffusivity in fired clay brick.

The real time neutron and gamma radiography station at Maria reactor, Institute of Atomic Energy, Swierk, Poland, was used to investigate the isothermal water absorption into fired clay brick samples. The investigated brick is different from the bricks reported in El Abd and Milczarek [2004. Neutron radiology study of water absorption in porous building materials: anomalous diffusing analysis. J. Phys. D: Appl. Phys. 37, 2305-2313] in density and chemical composition. Neutron radiography images were acquired regularly as the absorption time elapses. The water content, theta, along the flow direction, x, namely the water profiles theta(x,t) and the water front position as a function of the absorption time, t, were extracted from neutron radiography images. The results were discussed in terms of the macroscopic theory of water infiltration in unsaturated porous media. It was shown that the water front position followed the square root t-scaling (x(m)=phi(m) square root t) and the profiles (theta-phi) converged to a universal one master curve. The water diffusivity was analytically determined from the experimental results. It has the so-called hypo-diffusive character, namely its gradient with respect to the water content is positive. Neutron radiography is a powerful method to distinguish among the unsaturated flow in different porous construction materials.