The study of viscoelastic behavior of blood vessels

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The mechanical properties of surfactant and the effects on the lung respiration.

The surfactans in the lungs prevent water droplets from blocking airways. High surface tension would tend to decrease the surface area of the lungs, thus making it harder to absorb air. The surface tension of pure water is about 70 mN/m. With lung surfactant, it can drop lower than 2 mN/m. The Mechanical Properties of the Surfactant are considered and investigated for the physiological effects generated during the process of respiration in the lung

La meccanica del parto

La cardiotocografia uterina è utile per rilevare la principali anomalie della contrattilità uterina. In base ai tracciati ottenuti dalle registrazioni relative alle contrazioni uterine del travaglio del parto è possibile rappresentare tale processo attraverso un modello matematico espresso dalla step function. Osservando così il parto come sequenza temporale di condizioni regolate da leggi fisiche si può descrivere l' intero processo come funzione del tempo espressa da un modello matematic

Study on the Mechanical Properties of the Tissues of the Great Arteries

The studies on cardiovascular system introduced by Max Anliker and coll have been very important because have opened a new method to look to determine the mechanical properties of the wall of the large vessels. The data have given the constant phase velocities for the pressure, axial and torsion waves, also the laws of attenuation of these waves were egual with exponential law with a negative constant multiplied by proportion of distance and wavelength. The law of attenuation has open a great problem of discussion, because the biological tissues have viscous-elastic properties but not linear as everybody who knows such materials knows. Now if a biological soft tissue has a deformation to return to the original condition is not given by a curve of presenting an egual shape but the presence of Coulomb resistance to deformation gives the particular low damping of the return to original dimension. The Knopoff theory has been used to arrive to a solution and explication of the experimental results by Anliker. We do not discuss now the mathematical problems and the equations connected to this theoretical biomechanical analysis, but if somebody is interested to discuss we have no problems of fit, because wee must see the interest of this medical people present now. When a transplant of organ is made we have the arteries of two different persons are connected and we are in presence of two similar but not egual wall are sutured, if the second is more soft then the previous part, will generate to a short period of time a stenosis due to a turbulent movement of the blood in the initial part of the new artery, with the process of sedimentation of the blood cells and obviously the sutured part is closed, the blood has at first difficulty to enter in the donor organs and day by day the blood stops and the donor organ is out owing to a necrosis. We have seen how this process can arrive to interest tilt 10% of patient, when the different age between patient and donor is of 15 years and the donor is younger in kidney transplantation. The definition of this effect was called Bononiensis Control Parameter (BCP). In conclusion, the importance of the determination of the viscous-elastic properties of the great vessels of cardiovascular system of a patient is very important to define and know when a transplant is necessary, looking for and selecting the more similar condition of the donor vessels or prosthesis

Drug Delivery Nanoparticles in Skin Cancers

Nanotechnology involves the engineering of functional systems at nanoscale, thus being attractive for disciplines ranging from materials science to biomedicine. One of the most active research areas of the nanotechnology is nanomedicine, which applies nanotechnology to highly specific medical interventions for prevention, diagnosis, and treatment of diseases, including cancer disease. Over the past two decades, the rapid developments in nanotechnology have allowed the incorporation of multiple therapeutic, sensing, and targeting agents into nanoparticles, for detection, prevention, and treatment of cancer diseases. Nanoparticles offer many advantages as drug carrier systems since they can improve the solubility of poorly water-soluble drugs, modify pharmacokinetics, increase drug half-life by reducing immunogenicity, improve bioavailability, and diminish drug metabolism. They can also enable a tunable release of therapeutic compounds and the simultaneous delivery of two or more drugs for combination therapy. In this review, we discuss the recent advances in the use of different types of nanoparticles for systemic and topical drug delivery in the treatment of skin cancer. In particular, the progress in the treatment with nanocarriers of basal cell carcinoma, squamous cell carcinoma, and melanoma has been reported

5-Fluorouracil resistant colon cancer cells are addicted to OXPHOS to survive and enhance stem-like traits

Despite marked tumor shrinkage after 5-FU treatment, the frequency of colon cancer relapse indicates that a fraction of tumor cells survives treatment causing tumor recurrence. The majority of cancer cells divert metabolites into anabolic pathways through Warburg behavior giving an advantage in terms of tumor growth. Here, we report that treatment of colon cancer cell with 5-FU selects for cells with mesenchymal stem-like properties that undergo a metabolic reprogramming resulting in addiction to OXPHOS to meet energy demands. 5-FU treatment-resistant cells show a de novo expression of pyruvate kinase M1 (PKM1) and repression of PKM2, correlating with repression of the pentose phosphate pathway, decrease in NADPH level and in antioxidant defenses, promoting PKM2 oxidation and acquisition of stem-like phenotype. Response to 5-FU in a xenotransplantation model of human colon cancer confirms activation of mitochondrial function. Combined treatment with 5-FU and a pharmacological inhibitor of OXPHOS abolished the spherogenic potential of colon cancer cells and diminished the expression of stem-like markers. These findings suggest that inhibition of OXPHOS in combination with 5-FU is a rational combination strategy to achieve durable treatment response in colon cancer