Oil spills in the Barents Sea: The results of multiyear monitoring with synthetic aperture radar.

This paper presents the results of multiyear satellite monitoring of oil pollution in the Barents Sea conducted in 2015-2020. Monitoring was based on synthetic aperture radar (SAR) images from the European Space Agency's Sentinel-1A and Sentinel-1B satellites. During monitoring, more than 26,000 SAR images were collected and analyzed for oil pollution in the form of oil spills. A geographic information system (GIS) and a conventional interactive technique were used to efficiently analyze a substantial number of SAR images covering the Barents Sea. Our approach employed online geoportal based on GIS technology with a large volume of additional information (oceanographic, physical-geographical, and industrial) about the marine basin, including those for offshore oil and gas infrastructure. As a result, multiyear oil spill distribution map was generated and analyzed, and the most oil-polluted regions of the sea and natural seeps were identified. The analysis focused on the general characteristics of the spatial and temporal distribution and the main sources of oil pollution of the Barents Sea. Sources of oil spills with areas ranging from 0.5 to 90 km2 were interpreted based on data from the automatic ship identification systems used to monitor shipping and fishing. Based on the monitoring results, the general level of oil pollution in the Barents Sea is established, statistics were calculated, and risk zones identified. The most polluted marine areas are in the southern part of the sea, where maritime shipping continuous; moderate levels of pollution appear in the fishing zones in the central part of the sea. Finally, the study results show that overall oil pollution in the Barents Sea is still relatively low compared to other marginal and inland seas of Europe.

[Surgical treatment of large and giant vertebrobasilar aneurysms manifested by brainstem compression symptoms]. / Khirurgicheskoe lechenie krupnykh i gigantskikh anevrizm vertebrobaziliarnogo basseina, proiavliaiushchikhsia simptomatikoi kompressii stvola golovnogo mozga.

The study aim was to analyze the results of surgical treatment of vertebrobasilar (VB) aneurysms manifested by brainstem compression symptoms. MATERIAL AND METHODS: The study included 8 patients operated on in the period between 2014 and 2017. All patients underwent intravascular intervention; two patients had open surgery at the second stage. RESULTS AND CONCLUSION: Intravascular intervention, both alone and in combination with open surgery, is effective treatment of VB aneurysms whose clinical picture is manifested by brainstem compression symptoms. The use of flow-diverting stents in most cases has provided good radicalness in the long-term period, without worsening the functional outcome. Treatment of fusiform aneurysms of the basilar artery trunk requires separate consideration and an individual approach due to a high risk of thrombosis of short branches feeding the brainstem.

[Extrapontine myelinolysis developed after aneurysmal subarachnoid hemorrhage (a case report and literature review)]. / Ekstrapontinnyi mielinoliz, razvivshiisya posle anevrizmaticheskogo subarakhnoidal'nogo krovoizliyaniya (sluchai iz praktiki i obzor literatury).

TOPICALITY: Central pontine and extrapontine myelinolysis is a rare and dangerous form of the demyelinating process of undefined origin, the development of which is associated with a very low sodium level in the blood (hypernatremia). OBJECTIVE: To describe a rare case of extrapontine myelinolysis as a complication occurring in the hemorrhagic period of anterior communicating artery aneurysm rupture as well as to demonstrate that this condition can be diagnosed intravitally. CONCLUSION: Clinical vigilance of extrapontine myelinolysis may promote the timely diagnosis and treatment of this disease, which is a potential cause of death. Pulse-therapy with glucocorticoids provides the opportunity to achieve regression of neurological symptoms and to stabilize the patient's condition.

[Effect of a vascular event on drug regimen compliance in patients with coronary atherosclerosis].

In order to assess the effect of a vascular event on adherence to treatment we examined a total of 68 patients presenting with coronary atherosclerosis. The patients' age varied from 31 to 84 years (mean 57.1±8.7). There were 55 (81.1%) men and 13 (18.9%) women. Drug regimen compliance was evaluated by means of the Morisky-Green Medication Adherence Questionnaire before and after the vascular event. Of the 68 examined patients, 15 (22.1%) had not taken any therapeutic agents before the vascular event occurred, despite existing arterial hypertension. Drug regimen compliance prior to the vascular event was low in 82.4% of cases. The number of patients with coronary atherosclerosis and low compliance to treatment before the vascular event decreased significantly thereafter (p=0.0012). After the vascular event, the number of patients adhering to the doctor's recommendations on medicamentous therapy increases considerably. At the same time, a sufficiently great number of patients [about 30% of patients after endured myocardial infarction (MI) and 18% after transcutaneous coronary intervention (TCI)] still remain in the category of those "having low drug regimen compliance" and, accordingly, have high risk for the development of recurrent vascular events. Endured TCI increases patient compliance more significantly than MI, which requires additional study of a psychological component of the given fact.

Wide-aperture TeO2 AOTF at low temperatures: operation and survival.

The effect of temperature on the performance in a wide-angle paratellurite acousto-optic tunable filter (AOTF) is analyzed on the example of two different AOTF configurations. The present study is a by-product of the AOTF characterization for space-borne applications. The two AOTFs serve as dispersion elements in spectrometers for Moon and Mars space missions. The operation of the AO filters was tested in the range of -50° to+40°C; we have also demonstrated the survival of an AOTF device at -130°C. The phase matching ultrasound frequency varies with temperature within 2.5×10(-5) K(-1) and 6.6×10(-5) K(-1). We link this temperature shift to elastic characteristics of the TeO2, and demonstrate that it is mostly explained by the temperature modification of the slow acoustic wave velocity. We point out the best reference describing experimental results (Silvestrova et al., 1987). A generalization is made for all wide-angle acousto-optic tunable filters based on tellurium dioxide crystal.

Single dust-particle rotation in glow-discharge plasma.

Rotation of a single dust granule (spin) is investigated experimentally in a stratified glow discharge. We employ the technique of measurement of the angular velocity, which is based on coordinate tracing of the light scattered by a hollow transparent particle. The angular velocity measured in the experiment is about 1-2 orders of magnitude higher than observed in previous experiments. We found that the angular velocity depends linearly on the discharge current. The mechanism of rotation of the granule is also described.

Efflux of potassium ions from cells and spheroplasts of Saccharomyces cerevisiae yeast treated with silver and copper ions.

Silver ions induce the efflux of potassium from cells of the yeast Saccharomyces cerevisiae but have no such effect on spheroplasts. Copper ions and the natural fungicide 2-O-3-hydroxyhexanoyl-beta-D-glucopyranosyl-(1-->4)-(6-O-acetyl-beta-D-glucopyranosyl-(1-->16)-2,15,16-trihydroxyhexadecanoic acid) induce the efflux of potassium ions from both cells and spheroplasts of S. cerevisiae. Silver and copper ions inhibit the activity of the plasma membrane H+-ATPase during the treatment of both cells and spheroplasts. It is supposed that the inability of silver ions to stimulate potassium efflux from spheroplasts results from damage to some components of K+ transport systems during preparation of spheroplasts.

Rotational motion of dusty structures in glow discharge in longitudinal magnetic field.

The investigation of dust structure formed in glow discharge in an external longitudinal magnetic field with induction up to 400 G applied is presented in this work. The dust structure starts to rotate in the magnetic field. The angular-velocity magnitude is one to two orders larger than one in other discharge types. Its dependence on the magnetic field is nonmonotonic. The rotation direction inverses with an increase of the magnetic induction value up to a certain magnitude B0. In close range of induction around B0 and under certain conditions the rotation of the upper and lower parts of the structure in the opposite direction is observed. Rotation is caused by the ion-drag force. The inversion of rotation direction relates with the change of plasma flows in the area of their formation in stratum with the magnetic field applied. The effect of ion flows was investigated in two additional experiments on the observation of structure rotation onset and on gravity-driven probing of stratum. The angular-velocity unhomogeniety allowed us to investigate shearing and to observe melting of the dust crystal. The correlation functions approach showed the occurrence of structure transformation and its phase transition of the meltinglike type in the magnetic field.

Conformational structures and vibrational spectra of isolated pyrimidine nucleosides: Fourier transform infrared matrix isolation study of 2-deoxyuridine.

The conformational structures of 2-deoxyuridine (dU) were investigated using Fourier transform infrared (FTIR) matrix isolation spectroscopy. For the first time the FTIR spectra of dU in Ar matrices were obtained in the range 4000-200 cm(-1). The stabilities of conformers were estimated by the methods HF/3-21G (p), HF/6-31G (d,p) and MP2/6-31G (d,p). Ab initio calculations of the infrared spectra were performed by the methods HF/3-21G (p) and HF/6-31G (d,p). The actual occupancy of conformational isomers in matrix samples was determined. It was shown that anti-conformers of dU are dominant. The ribose rings of the main anti-conformers dU _a0, dU _a1 are in the C2'-endo conformation, but the ribose rings of minor anti-conformers dU_a2, dU_a3 have the C3'-endo conformation, stabilized by intramolecular hydrogen bonds O3'H...O5' and O5'H...O3', accordingly. Syn-conformers of dU are stabilized by the intramolecular hydrogen bond O5'H...O2 and the dominant conformation of the ribose ring is C2'-endo.