New Polarimetric Data for the Galilean Satellites : Europa Observations and Modeling

Peer reviewe

Нарушения системы гемостаза в колоректальной хирургии

This article tells about changes in hemostasis due to various factors (colorectal cancer surgery – 24 patients, 27 patients after radiochemotherapy, simultaneous operations on liver and intestines in patients with metastases of colorectal cancer – 24 patients). The evaluation of hemostatic factors and clinical data could prove instability in hemostasis in various groups and the possibility of either thromboembolic or hemorrhagic complications. The majority of abnormalities was proven to be in simultaneous operations on colon and liver, especially extensive liver resections. The coagulation profile should be continiously monitored when you deal with thromboembolism prophylaxis.В статье обсуждаются изменения в системе гемостаза, обусловленные разными причинами (при хирургическом лечении колоректального рака – 24 больных, операции после химиолучевой терапии – 27 пациента, комбинированные операции с резекцией печени при метастазах колоректального рака – 24 больных). Сравнительная оценка показателей системы гемостаза и клинические данные позволили выявить нестабильность данной системы в разных группах и возможность развития как тромботических осложнений, так и опасности развития периоперационного неуправляемого кровотечения. Наибольшая частота нарушений в системе гемостаза отмечена при комбинированных симультанных вмешательствах и обширной резекции печени. Специфическая антикоагулянтная профилактика требует динамического мониторинга как со стороны свертывающих факторов, так и антикоагулянтов

New Polarimetric Data for the Galilean Satellites: Io and Ganymede Observations and Modeling

New high-precision disk-integrated measurements of the polarization of Io and Ganymede in the UBVRI bands are presented. The observations were obtained using polarimeters mounted on the Crimean Astrophysical Observatory and the Peak Terskol Observatory in 2019–2023. For Io, the negative polarization branch (NPB) reaches a minimum of P _min ≈ −0.25 ± 0.02% in the V band at a phase angle of α _min = 2.°1 ± 0.°5. The inversion angle is α _inv = 26° ± 6° in the V and R bands. The NPB for Ganymede is an asymmetric curve, with P _min = −0.34 ± 0.01% at α _min = 0.°52 ± 0.°06 and α _inv = 8.°5 ± 0.°2 in the V band. Although Io and Europa have similar geometric albedos (0.63 and 0.67, respectively), their NPB shapes differ. The NPB of Ganymede (albedo of 0.43) is morphologically similar to that of Europa, although it is described by different parameter values ( P _min , α _min , and α _inv ). This discrepancy is likely due to the compositions of their surfaces: Europa’s with H _2 O ice, Io’s with sulfuric/silicate composition, and Ganymede’s with H _2 O ice and silicates. Numerical computations using the radiative transfer coherent backscattering method demonstrated a match to the polarimetric observations and to the geometric albedos for Ganymede with the single-scattering albedo ≈ 0.943 and mean free path length kl = 2 πl / λ _eff ≈ 150, where λ _eff is the wavelength. For Io’s regolith, the single-scattering albedo was found to be ≈ 0.979 and kl ≈ 40