ABSTRACT
Modeling of drug transport within capillaries and tissue remains a challenge, especially in tumors and cancers where the capillary network exhibits extremely irregular geometry. Recently introduced Composite Smeared Finite Element (CSFE) provides a new methodology of modeling complex convective and diffusive transport in the capillary-tissue system. The basic idea in the formulation of CSFE is in dividing the FE into capillary and tissue domain, coupled by 1D connectivity elements at each node. Mass transport in capillaries is smeared into continuous fields of pressure and concentration by introducing the corresponding Darcy and diffusion tensors. Despite theoretically correct foundation, there are still differences in the overall mass transport to (and from) tissue when comparing smeared model and a true 3D model. The differences arise from the fact that the smeared model cannot take into account the detailed non-uniform pressure and concentration distribution in the vicinity of capillaries. We introduced a field of correction function for diffusivity through the capillary walls of smeared models, in order to have the same mass accumulation in tissue as in case of true 3D models. The parameters of the numerically determined correction function are: ratio of thickness and diameter of capillary wall, ratio of diffusion coefficient in capillary wall and surrounding tissue; and volume fraction of capillaries within tissue domain. Partitioning at the capillary wall - blood interface can also be included. It was shown that the correction function is applicable to complex configurations of capillary networks, providing improved accuracy of our robust smeared models in computer simulations of real transport problems, such as in tumors or human organs.
ABSTRACT
Colour changes in Gradia Direct™ composite after immersion in tea, coffee, red wine, Coca-Cola, Colgate mouthwash, and distilled water were evaluated using principal component analysis (PCA) and the CIELAB colour coordinates. The reflection spectra of the composites were used as input data for the PCA. The output data (scores and loadings) provided information about the magnitude and origin of the surface reflection changes after exposure to the staining solutions. The reflection spectra of the stained samples generally exhibited lower reflection in the blue spectral range, which was manifested in the lower content of the blue shade for the samples. Both analyses demonstrated the high staining abilities of tea, coffee, and red wine, which produced total colour changes of 4.31, 6.61, and 6.22, respectively, according to the CIELAB analysis. PCA revealed subtle changes in the reflection spectra of composites immersed in Coca-Cola, demonstrating Coca-Cola's ability to stain the composite to a small degree.
Subject(s)
Color , Composite Resins/chemistry , Principal Component Analysis/methods , Staining and Labeling/methods , Carbonated Beverages , Coffee/chemistry , Mouthwashes/chemistry , Spectrophotometry , Tea/chemistry , Water/chemistry , WineABSTRACT
Behcet's disease is a recurrent, systemic inflammatory disease of the vasculitides group. It has been most frequently diagnosed in Japan and east Mediterranean countries. Its clinical picture is characterised by multiple organ and systemic defects indicating vasculitis. In addition to triple symptom of complex (recurrent ulcerations of the oral cavity and genital organs, eye lesions in the form of episcleritis, uveitis and hypopyon), other symptoms and signs are also frequent. Aetiology of the disease has not yet been completely elucidated. Immunosuprressive agents, as a single therapy or combined with glycocorticoid drugs, are used in treatment of Behcet's disease. As for the prognosis of the Behcet's disease, chronic exacerbation of the symptoms and signs is typical, and insufficiently aggressively treated posterior uveitis usually results in blindness. The prognosis is also poor in case of central nervous system and large arterial blood vessels lesions.
Subject(s)
Behcet Syndrome , Behcet Syndrome/diagnosis , Behcet Syndrome/therapy , HumansABSTRACT
We reviewed a complex nuclear medical method's application for investigating venous circulation of lower extremities--radionuclide venography (RVG) in explaining a case of suspective ileofemoral thrombosis. Suffering from pain and swelling of the right leg, patient T.J. wanted a checkup. After the physical examination, vascular surgeon suspected phlebothrombosis of the right ileofemoral region and immediately sent her to have a radionuclide venography (RVG) (because by Doppler-ultrasonography certain data confirming presence of thrombus in the pelvic region couldn't be gained). On the basis of gathered results vascular surgeon can make a final diagnosis (phlebothrombosis of the right vein femoralis), so that in this case flebography was not necessary. Although performing RVG is complex and requires engagement of experts of different profiles, gathered data are valuable because they cover the shortage of existing diagnostic methods which are most often used in routine work (Doppler-ultrasonography and phlebography). Applying RVG phlebography can be avoided in all patients who are not expected to have operative treatment, and in cases where thrombosis is suspected in deep veins of pelvis, RVG can be performed right away, without Doppler ultrasonography.
Subject(s)
Femoral Vein/diagnostic imaging , Iliac Vein/diagnostic imaging , Thrombosis/diagnostic imaging , Adult , Female , Humans , Radionuclide ImagingABSTRACT
Two groups of patients with chronic pulmonary tuberculosis are presented. The first group of 92 patients were unsuccessfully treated according to current principles of treatment of chronic, resistant pulmonary tuberculosis. In the second group of 11 patients, unsuccessfully treated according to current methods, a new combination of drugs was applied so that a drug of the aminoglycoside group or chinolon group (Amikacin 1000 mg every second day or Ciprofloxacin 750 mg daily) was added to conventional therapy. Applying such therapy during 4 months encouraging results have been obtained.
