[Trends in endovascular treatment and prevention of portal bleeding]. / Tendentsii v rentgenendovaskulyarnom lechenii i profilaktike portal'nykh krovotechenii (obzor literatury).

Bleeding from esophageal and gastric varices is a major factor of mortality in patients with portal hypertension. The gold standard for diagnosis of portal hypertension is hepatic venous pressure gradient determining the treatment algorithms and risk of recurrent bleeding. Combination of endoscopic methods and therapy is limited by varix localization and not always effective. In these cases, endovascular bypass and decoupling techniques are preferred. Early endovascular treatment of portal bleeding is effective for hemostasis and higher transplantation-free survival of patients. Early transjugular intrahepatic portosystemic bypass should be associated with 8-mm covered stents of controlled dilation. Combination of endovascular techniques reduces the complications of each technique and potentiates their positive effect. Endovascular treatment and prevention of portal bleeding should be determined by anatomical features of portal venous system.

A black-box approach to the construction of metal-radical multispin systems and analysis of their magnetic properties.

An interaction of M(hfac)2 (M = Mn or Ni) with N-(bis(4,4,5,5-tetramethyl-3-oxido-1-oxyl-4,5-dihydro-1H-imidazol-2-yl)methylene)-2-methyl-propan-2-amine oxide (a nitronyl nitroxide diradical with the >C[double bond, length as m-dash]N(O)-tert-Bu coupler) was investigated under various conditions. It was found that prolongation of reaction time caused transformation of the initial diradical into new diradicals with the unique >C[double bond, length as m-dash]N-OH coupling unit and formation of binuclear Mn(ii) and Ni(ii) complexes, which were characterized by X-ray diffraction analysis. The resulting binuclear heterospin complexes have a complicated magnetic structure with six paramagnetic centers and a number of exchange interaction channels between them, as well as between neighboring complexes. To adequately describe the magnetic properties of these complexes, high-level ab initio calculations of their electronic structure and parameters of the spin-Hamiltonian were carried out. The accuracy of the conventional broken-symmetry density functional theory approach in the calculation of the exchange interaction parameters was also verified.