35 research outputs found
Сhemical composition of bottom sediments in small mountain rivers (Altai, the Russian Federation)
No full textThe article deals with the chemical composition of bottom sediments in the small mountain rivers Aktru, Tyute, and Uznezya (Altai, Russia). It is established that as compared to small and middle plain rivers in Taiga zone, Siberia bottom sediments of the Aktru River contain less amount of K, Na, V, Cr, Mn, Ni, Al, Si, Ti, Sr, approximately the same – Fe, Co, Cu, Zn, Pb and more – As, Ca, Mg. It is suggested that there is a sharp increase of relative Al, Na, K and Si shares from the upland to lowland due to both weathering products accumulation of primary alumosilicates in bottom sediments and export of Ca and Mg from them when dissolving carbonate minerals. Composition transformations of bottom sediments is non-linear and considerably depends on composition of underlying and water-bearing rocks and water exchange intensity that manages time, conditions, and stages of interactions in “water – organic matter – rock” system
Chemical Composition of Bottom Sediments in Small Mountain Rivers (Altai, the Russian Federation)
No full textThe article deals with the chemical composition of bottom sediments in the small mountain rivers Aktru, Tyute, and Uznezya (Altai, Russia). It is established that as compared to small and middle plain rivers in Taiga zone, Siberia bottom sediments of the Aktru River contain less amount of K, Na, V, Cr, Mn, Ni, Al, Si, Ti, Sr, approximately the same - Fe, Co, Cu, Zn, Pb and more - As, Ca, Mg. It is suggested that there is a sharp increase of relative Al, Na, K and Si shares from the upland to lowland due to both weathering products accumulation of primary alumosilicates in bottom sediments and export of Ca and Mg from them when dissolving carbonate minerals. Composition transformations of bottom sediments is non-linear and considerably depends on composition of underlying and water-bearing rocks and water exchange intensity that manages time, conditions, and stages of interactions in "water - organic matter - rock" system
Predictors of complications when transferring postoperative cardiac patients from the intensive care unit
No full textAim. Emphasis in the study was placed on the evaluation of predictors of complications when transferring postoperative cardiac patients from the intensive care unit (ICU).Methods. 60 patients after cardiac surgery were included into this prospective observational study, with 41 of them undergoing off-pump coronary artery bypass grafting (CABG). Before the transfer from ICU, echocardiographical criteria of their systolic and diastolic dysfunction, parameters of oxygenation, hemodynamic and metabolism status, as well as postoperative complications and duration of hospitalization were evaluated. Results. Preoperatively, the patients had a moderate degree of heart failure and preserved ejection fraction. Those patients who had undergone valvular and combined procedures using cardiopulmonary bypass had higher Euroscore II values, more severe heart failure, prolonged duration of surgery, respiratory support and hospitalization in ICU and in hospital. The echocardiographical criteria of diastolic dysfunction before transfer from ICU were recorded in 14-77% patients. Despite a normal range of blood pressure, the systolic function of the left ventricle and preload (left atrial pressure), oxygenation and metabolic status, venous to arterial carbon dioxide difference (Pv-aCO2) and left ventricle performance index (Tei) exceeded the normal values before transfer from ICU. The correlation analysis revealed a relationship between duration of ICU and hospital stay and the criteria of heart failure severity (left atrial pressure [rho = 0.27, 95% CI 0.02–0.48, p = 0.04]) and left ventricle dysfunction (e’ [rho = 0.41, 95% CI 0.17–0.59, p<0.01]) before the transfer. The increase in fluid balance during ICU stay after off-pump coronary artery bypass surgery tended to result in a complicated postoperative period (AUC = 0.73, p = 0.02) and a higher risk of atrial fibrillation.Conclusion. The impairment of the left ventricle diastolic function before transferring from ICU correlates with the duration of hospitalization. A positive fluid balance during ICU period after off-pump surgery might bring about postoperative complications and atrial fibrillation, thus predicting their onset.Received 5 April 2017. Revised 10 August 2017. Accepted 15 August 2017.Funding: The study did not have sponsorship.Conflict of interest: The authors declare no conflict of interest.AcknowledgementThe authors express their gratitude for patience and support during the study to the staff of Cardiac Surgery Department and Resuscitation Department.</p
Synthesis of Diaminoacetic Acid Derivatives as a Promising Scaffold for the Synthesis of Polyheterocyclic Cage Compounds
No full textHere,
we explored
in detail an acid-catalyzed condensation of glyoxylic
acid or its ethyl ester with several carboxamides of different basicity,
or with mesyl amide, to furnish diaminoacetic acid derivatives. The
most suitable synthesis conditions and the reaction catalysts were
identified. Properties such as structure and basicity of the starting
amides were demonstrated to influence the condensation process. Elemental
iodine was used for the first time herein as an acid catalyst for
the condensation of glyoxylic acid or its ester, which gave access
to diaminoacetic acid derivatives in higher yields in most cases,
as opposed to p-toluenesulfonic acid (PTSA). An abnormally high activity
of mesyl amide when condensed with ethyl glyoxylate was noticed, which
may evidence a special impact of the sulfonyl moiety in the amide
molecule on the condensation
Synthesis of new N-polysubstituted oxaazaisowurtzitanes by acid-catalyzed condensation of sulfonamides with glyoxal
No full textOxaazatetracyclo[5.5.0.03, 10.05, 8]Dodecanes – a Promising Foundation for the Design of Thermally Stable, High-Density Energetic Compounds
No full textPredictors of complications when transferring postoperative cardiac patients from the intensive care unit
Get PDF<p><strong>Aim.</strong> Emphasis in the study was placed on the evaluation of predictors of complications when transferring postoperative cardiac patients from the intensive care unit (ICU).<br /><strong>Methods.</strong> 60 patients after cardiac surgery were included into this prospective observational study, with 41 of them undergoing off-pump coronary artery bypass grafting (CABG). Before the transfer from ICU, echocardiographical criteria of their systolic and diastolic dysfunction, parameters of oxygenation, hemodynamic and metabolism status, as well as postoperative complications and duration of hospitalization were evaluated. <br /><strong>Results.</strong> Preoperatively, the patients had a moderate degree of heart failure and preserved ejection fraction. Those patients who had undergone valvular and combined procedures using cardiopulmonary bypass had higher Euroscore II values, more severe heart failure, prolonged duration of surgery, respiratory support and hospitalization in ICU and in hospital. The echocardiographical criteria of diastolic dysfunction before transfer from ICU were recorded in 14-77% patients. Despite a normal range of blood pressure, the systolic function of the left ventricle and preload (left atrial pressure), oxygenation and metabolic status, venous to arterial carbon dioxide difference (Pv-aCO2) and left ventricle performance index (Tei) exceeded the normal values before transfer from ICU. The correlation analysis revealed a relationship between duration of ICU and hospital stay and the criteria of heart failure severity (left atrial pressure [rho = 0.27, 95% CI 0.02–0.48, p = 0.04]) and left ventricle dysfunction (e’ [rho = 0.41, 95% CI 0.17–0.59, p&lt;0.01]) before the transfer. The increase in fluid balance during ICU stay after off-pump coronary artery bypass surgery tended to result in a complicated postoperative period (AUC = 0.73, p = 0.02) and a higher risk of atrial fibrillation.<br /><strong>Conclusion.</strong> The impairment of the left ventricle diastolic function before transferring from ICU correlates with the duration of hospitalization. A positive fluid balance during ICU period after off-pump surgery might bring about postoperative complications and atrial fibrillation, thus predicting their onset.</p><p>Received 5 April 2017. Revised 10 August 2017. Accepted 15 August 2017.</p><p><strong>Funding:</strong> The study did not have sponsorship.</p><p><strong>Conflict of interest:</strong> The authors declare no conflict of interest.</p><p><strong>Acknowledgement</strong><br />The authors express their gratitude for patience and support during the study to the staff of Cardiac Surgery Department and Resuscitation Department.</p></jats:p
Chemical Composition of Bottom Sediments in Small Mountain Rivers (Altai, the Russian Federation)
No full textThe article deals with the chemical composition of bottom sediments in the small mountain rivers Aktru, Tyute, and Uznezya (Altai, Russia). It is established that as compared to small and middle plain rivers in Taiga zone, Siberia bottom sediments of the Aktru River contain less amount of K, Na, V, Cr, Mn, Ni, Al, Si, Ti, Sr, approximately the same – Fe, Co, Cu, Zn, Pb and more – As, Ca, Mg. It is suggested that there is a sharp increase of relative Al, Na, K and Si shares from the upland to lowland due to both weathering products accumulation of primary alumosilicates in bottom sediments and export of Ca and Mg from them when dissolving carbonate minerals. Composition transformations of bottom sediments is non-linear and considerably depends on composition of underlying and water-bearing rocks and water exchange intensity that manages time, conditions, and stages of interactions in “water – organic matter – rock” system
ESTIMATION OF CURRENT DYNAMICS AND FORECAST OF GLACIOLOGICAL CHARACTERISTICS OF THE MALYI AKTRU GLACIER (CENTRAL ALTAI)
Get PDFIn the context of global and regional climatic changes in the Altai mountain region, observations performed in 1949–2014 demonstrated evident rises of air temperatures, both annual and seasonal means. Relative to the climatic norm (1949–1985), mean annual temperature (averaged for the period 1986–2014) had risen by 0.8– 1.9 °С. The most significant warming took place in winter and spring. In winter, the positive difference with the mean value is approximately equal to 0.9–3.8 °C, while in spring 0.9 and 1.7 °C. Air temperatures in summer and autumn periods were rising as well. Changes in annual and seasonal precipitations were more variable. The autumn and winter periods are characterized by a decrease in precipitation. On average, it is respectively 17% and 6%. In the spring and summer seasons, the tendency is opposite since these periods are characterized by a weak increase in precipitation. On average for the whole territory, the increase in the mean climatic amount of seasonal precipitation was equal to 2% and 4% relative the climatic norm for 1966–1985, for spring and summer respectively. The amount of annual precipitation on theterritoryofGorny Altairemained unchanged. Under current climate conditions which are characterized by decreasing in winter precipitation, the air temperature rise during all seasons, and longer warm period the mass balance of the Malyi Aktru Glacier becomes drastically negative. Total accumulation decreases, the ablation increases, and as a result, the negative mass balance grows. Using the methods of exponential smoothing, given the type of the trend component in series of meteorological quantities, a forecast of a 10‑year mean air temperature and the amount of atmospheric precipitation was made for the period 2021–2030. Using the appropriate regression equations, this allowed calculating predictive mean values of accumulation, ablation, and mass balance of the Malyi Aktru Glacier for the third decade of the XXI centur
