RESUMO
We develop a first-principle equation of state of salt-free polyelectrolyte solution in the limit of infinitely long flexible polymer chains in the framework of a field-theoretical formalism beyond the linear Debye-Hueckel theory and predict a liquid-liquid phase separation induced by a strong correlation attraction. As a reference system, we choose a set of two subsystems-charged macromolecules immersed in a structureless oppositely charged background created by counterions (polymer one component plasma) and counterions immersed in oppositely charged background created by polymer chains (hard-core one component plasma). We calculate the excess free energy of polymer one component plasma in the framework of modified random phase approximation, whereas a contribution of charge densities' fluctuations of neutralizing backgrounds we evaluate at the level of Gaussian approximation. We show that our theory is in a very good agreement with the results of Monte Carlo and MD simulations for critical parameters of liquid-liquid phase separation and osmotic pressure in a wide range of monomer concentration above the critical point, respectively.
RESUMO
Morbidity and mortality from pancreatic cancer is steadily increasing. Resectable cases are not more than 20%. Conventional schemes of chemoradiation and radiation therapy are durable over the time, have toxicity and low treatment outcomes. Many foreign authors consider as promising the technique of stereotactic radiotherapy, which is often used in pancreatic cancer and permit achieving high local control. At our institution there has been developed and introduced into clinical practice a method of stereotactic radiotherapy for the palliative treatment of patients with pancreatic cancer, which improved not only the duration but also the quality of life of patients.
