Search results for "Diffusion"
showing 10 items of 1615 documents
Diffusion equations with negentropy applied to denoise mammographic images.
2006
Mammography is a radiographic technique used for the detection of breast lesions. The analysis of the digital image normally requires a previous application of filters as a preprocessing step to reduce the noise level of the image, while preserving important details to carry out a suitable diagnostic. In the literature, there are a large amount of denoising techniques applied to different medical images. In this work we have studied the performance of a diffusive filter with a stopping condition based on the statistical concept of negentropy, applied to denoise mammographic images. The negentropy has been succesfully prove with other denoising methods as independent component analysis by th…
Role of apparent diffusion coefficient values in prostate diseases characterization on diffusion-weighted magnetic resonance imaging.
2019
BACKGROUND: To evaluate if normal and pathological prostate tissue can be distinguished by using apparent diffusion coefficient (ADC) values on magnetic resonance imaging (MRI) and to understand if it is possible to differentiate among pathological prostate tissues using ADC values.METHODS:Our population consisted in 81 patients (mean age 65.4 years) in which 84 suspicious areas were identified. Regions of interest were placed over suspicious areas, detected on MRI, and over areas with normal appearance, and ADC values were recorded. Statistical differences between ADC values of suspicious and normal areas were evaluated. Histopathological diagnosis, obtained from targeted biopsy using MRI-…
Diagnostic performance and reproducibility of T2w based and diffusion weighted imaging (DWI) based PI-RADSv2 lexicon descriptors for prostate MRI.
2017
To examine the diagnostic performance of PI-RADSv2 T2w and diffusion weighted imaging (DWI) based lexicon descriptors, inter-observer agreement for descriptor assignment and diagnostic accuracy of the PI-RADSv2 assessment categories for multiparametric prostate MRI.176 lesions in 79 consecutive patients are analyzed, lesions are histopathologically verified by MRI-ultrasound fusion biopsy. All lesions are rated according to the PI-RADSv2 lexicon, descriptors for T2w and DWI sequences and resulting assessment categories are assigned by two independent blinded radiologists. We perform receiver-operating-characteristic analysis using the assessment categories. To analyze inter-observer agreeme…
Sponge aggregation factor and sponge hemagglutinin: possible relationships between two different molecules.
1979
Abstract A lectin from the marine sponge GEODIA CYDONIUM was isolated and characterized. GEODIA lectin (GL) agglutinates human red blood cells irrespective of the ABO blood group and precipitates with a variety of D -galactose containing glycosubstances, i.e. certain snail galactans, bovine erythrocyte glycoprotein and PNEUMOCOCCUS type XIV polysaccharide. The only simple sugars inhibiting the GL-mediated hemagglutination were lactose and n -acetyl- D -galactosamine. GL was purified by affinity chromatography on Sepharose 4B almost to homogeneity as tested by polyacrylamide disc gel electrophoresis. Positive staining of the lectin band with Coomassie brilliant blue and PAS suggest that GL i…
Proteins in preterm and term milk from mothers delivering appropriate or small-for-gestational age infants.
1986
The concentrations of total protein, secretory immunoglobulin A (IgA), lactotransferrin (LTF) and serum albumin (SA) were measured in sequential samples of colostrum, transitional and mature milk from 53 mothers divided into four groups according to gestational age and birthweight of their infants. Individual proteins were determined by single radial immunodiffusion. From the covariance analysis of data controlling for the day of lactation and the milk volume it was found that these covariables were significantly negative correlated with total protein and IgA. The concentration of LTF was also significantly negative correlated with the day but positively with the volume; whereas the contrar…
In situ measurements of molecular iodine in the marine boundary layer: the link to macroalgae and the implications for O<sub>3</…
2010
Abstract. Discrete in situ atmospheric measurements of molecular iodine (I2) were carried out at Mace Head and Mweenish Bay on the west coast of Ireland using diffusion denuders in combination with a gas chromatography-mass spectrometry (GC-MS) method. I2, IO and OIO were also measured by long-path differential optical absorption spectroscopy (LP-DOAS). The simultaneous denuder and LP-DOAS I2 measurements were well correlated (R2=0.80) but the denuder method recorded much higher concentrations. This can be attributed to the fact that the in situ measurements were made near to macroalgal sources of I2 in the intertidal zone, whereas the LP-DOAS technique provides distance-averaged mixing rat…
Diffusion and Reactions of Hydrogen inF2-Laser-IrradiatedSiO2Glass
2002
The diffusion and reactions of hydrogenous species generated by single-pulsed F2 laser photolysis of SiO-H bond in SiO2 glass were studied in situ between 10 and 330 K. Experimental evidence indicates that atomic hydrogen (H0) becomes mobile even at temperatures as low as approximately 30 K. A sizable number of H0 dimerize by a diffusion-limited reaction into molecular hydrogen (H2) that may migrate above approximately 200 K. Activation energies for the diffusion, inherently scattered due to the structural disorder in glass, are separated into three bands centered at approximately 0.1 eV for free H0, approximately 0.2 eV presumably for shallow-trapped H0, and approximately 0.4 eV for H2.
Inclusive Design for Alzheimer’s Disease: Low-cost Treatments, Design and ICT
2019
Inability to acquire new memories, difficulty to remember recent events and to recognize objects, places and people, visual-spatial disorientation, these are some of the disorders with which who is affected by neurological diseases must learn to live with. In a continuously evolving society, where the decreasing birth rate and the drops in mortality are consistent, the job of Architecture is precisely to interpret the requirements and needs of people who have lost the canonical relationship with the world and give them the possibility to recover it or maintain it through communication channels that use their remaining ability to understand. The indoors and outdoors acquire a “prosthesis fun…
Diffusion dialysis for HCl and heavy metals separation from highly concentrated pickling solutions
2019
Disposal of pickling waste solutions strongly affects hot-dip galvanizing industries’ economics and environmental footprint. Thus, the recovery of acid is an important step to enhance the process sustainability. Diffusion dialysis (DD) can be used to separate acids and heavy metals (e.g. iron and zinc) from pickling waters, promoting the circular use of such raw materials. In the present work, two DD modules, a laboratory scale unit operating in batch and a continuous operated large unit, equipped with Fumasep anionic exchange membranes were tested. Results obtained show that zinc and iron affect HCl recovery in opposite way, however reaching high recovery values. In particular, zinc consid…