Ранние особенности кровообращения у больных с неблагоприятным исходом абдоминального сепсиса (предварительное сообщение)

Aim: to study characteristics of the central hemodynamics (CHD) in patients with severe abdominal sepsis with different outcomes of the disease.Materials and Methods. 18 patients with abdominal sepsis, aged 50.2±3, with the APACHE II and SOFA severity scoring of 13.7±0.8 and 8.4±0.5, respectively, were enrolled in the retrospective study. The CHD was studied using the transpulmonary thermodilution. The following groups were identified: Group 1 (deceased, n=9) and Group 2 (survivors, n=9). The groups did not differ (P>0.05) in age, sex, and the severity of the condition at admission to the ICU. The significance of differences was assessed using the t-test and the chi-squared test. The prognostic value of the parameters was studied using the ROC analysis.Results. On Day 1, the intergroup differences included the average blood pressure (BPav) (85.3±3.3 and 101.6±4.6 mmHg, respectively (P<0.05)) and the cardiac power index (CPI) (306±22 and 429.9±48.9 W/m2, respectively) (Р<0.05). The intergroup difference in the CPI and the global ejection fraction (GEF) persisted on Day 3: 22.3±2.3 and 29.3±1.5%, respectively (P<0.05); there was no other difference. The intergroup difference in the GEF remained on Day 5. On Day 7, the CHD parameters demonstrated no intergroup difference. The SOFA severity scoring in Group 1 patients became greater than that in Group 2 starting from Day 5. According to ROC analysis, BPav (95 mmHg, sensitivity: 88.9%, specificity: 88.9%), CPI (373 W/m2, sensitivity: 88.9%, specificity: 77.8%), and GEF (26.1%, sensitivity: 66.7%, specificity: 77,8%) were the most important predictors of the lethal outcome on Days 1—3 (areas under ROC curves: 0.765—0.840; P<0.05). On days 5—7, the SOFA scoring >7 (sensitivity: 88.9%, specificity: 88.9%) was the most important predictor of the lethal outcome (areas under ROC curves: 0.957—0.994; P<0.05).Conclusion: during the first five days of the intensive treatment of severe sepsis in patients with unfavorable prognosis, a moderate decrease in the cardiac power index and overall cardiac systolic function was registered. The prognostic significance of such parameters as CPI and GEF may become obvious within the first 3 days of the intensive treatment.Цель исследования: изучить особенности центральной гемодинамики (ЦГД) у больных тяжелым абдоминальным сепсисом при различных исходах заболевания.Материалы и методы. В ретроспективное исследование включили 18 больных абдоминальным сепсисом в возрасте 50,2±3 лет с тяжестью состояния по шкале APACHE II 13,7±0,8 балла, SOFA — 8,4±0,5 балла. ЦГД изучали с помощью транспульмональной термодилюции. Выделили группы больных: 1-я (умершие, n=9) и 2-я (выжившие , n=9). Группы не различались (p>0,05) по возрасту, половому составу и тяжести состояния больных при поступлении в отделение реаниматологии. Достоверность отличий оценивали по критерию t-критерию Стьюдента и критерию Хи-квадрат. Прогностическую значимость показателей изучали с помощью ROC-анализа.Результаты. В 1-е сутки межгрупповые отличия выявлены в уровне среднего артериального давления (АДср.) — 85,3±3,3 и 101,6±4,6 мм рт. ст. (р<0,05) и индекса мощности сердца (ИМС) — 306±22 и 429,9±48,9 Вт/м2 (р<0,05). На 3-и сутки сохранялись межгрупповые отличия значений ИМС, проявлялись отличия величины глобальной фракции изгнания сердца (ГФИС) — 22,3±2,3 и 29,3±1,5% (р<0,05); других отличий не было. На 5-е сутки сохранялось межгрупповое отличие значений ГФИС. На 7-е сутки показатели ЦГД не имели межгрупповых отличий. Тяжесть состояния по SOFA у больных 1-й группы становилась больше, чем во 2-й, начиная с 5-х суток. По данным ROC-анализа в 1-3-и сутки наиболее значимыми предикторами летального исхода (площади под ROC-кривыми 0,765—0,840; p<0,05) явились АДср. (95 мм рт. ст., чувствительность 88,9%, специфичность 88,9%), ИМС (373 Вт/м2, чувствительность 88,9%, специфичность 77,8%) и ГФИС (26,1%, чувствительность 66,7%, специфичность 77,8%). На 5—7-е сутки наиболее значимым предиктором летальности (площади под ROC-кривой 0,957—0,994; p<0,05) становилась тяжесть состояния по шкале SOFA >7 баллов (чувствительность 88,9%, специфичность 88,9%).Заключение: в течение первых 5-и суток интенсивного лечения тяжелого сепсиса у больных с неблагоприятным прогнозом заболевания отмечено умеренное снижение показателей мощности и общей систолической функции сердца. Прогностическая значимость таких показателей, как ИМС и ГФИС, может проявляться в первые трое суток интенсивного лечения

Eddies in the Western Arctic Ocean From Spaceborne SAR Observations Over Open Ocean and Marginal Ice Zones

The Western Arctic Ocean is a host to major ocean circulation systems, many of which generate eddies that can transport water masses and corresponding tracers over long distances from their formation sites. However, comprehensive observations of critical eddy characteristics are currently not available and are limited to spatially and temporally sparse in situ observations. Here we use high‐resolution spaceborne synthetic aperture radar measurements to detect eddies from their surface imprints in ice‐free sea surface roughness, and in sea ice patterns throughout marginal ice zones. We provide the first estimate of eddy characteristics extending over the seasonally ice‐free and marginal ice zone regions of the Western Arctic Ocean, including their locations, diameters, and monthly distribution. Using available synthetic aperture radar data, we identified over 4,000 open ocean eddies, as well as over 3,500 eddies in marginal ice zones from June to October in 2007, 2011, and 2016. Eddies range in size between 0.5 and 100 km and are frequently found over the shelf and near continental slopes but also present in the deep Canada Basin and over the Chukchi Plateau. We find that cyclonic eddies are twice more frequent compared to anticyclonic eddies at the surface, distinct from the dominating anticyclonic eddies observed at depth by in situ moorings and ice‐tethered profilers. Our study supports the notion that eddies are ubiquitous in the Western Arctic Ocean even in the presence of sea ice and emphasizes the need for improved ocean observations and modeling at eddy scales

Eddies in the Western Arctic Ocean From Spaceborne SAR Observations Over Open Ocean and Marginal Ice Zones

The Western Arctic Ocean is a host to major ocean circulation systems, many of which generate eddies that can transport water masses and corresponding tracers over long distances from their formation sites. However, comprehensive observations of critical eddy characteristics are currently not available and are limited to spatially and temporally sparse in situ observations. Here we use high‐resolution spaceborne synthetic aperture radar measurements to detect eddies from their surface imprints in ice‐free sea surface roughness, and in sea ice patterns throughout marginal ice zones. We provide the first estimate of eddy characteristics extending over the seasonally ice‐free and marginal ice zone regions of the Western Arctic Ocean, including their locations, diameters, and monthly distribution. Using available synthetic aperture radar data, we identified over 4,000 open ocean eddies, as well as over 3,500 eddies in marginal ice zones from June to October in 2007, 2011, and 2016. Eddies range in size between 0.5 and 100 km and are frequently found over the shelf and near continental slopes but also present in the deep Canada Basin and over the Chukchi Plateau. We find that cyclonic eddies are twice more frequent compared to anticyclonic eddies at the surface, distinct from the dominating anticyclonic eddies observed at depth by in situ moorings and ice‐tethered profilers. Our study supports the notion that eddies are ubiquitous in the Western Arctic Ocean even in the presence of sea ice and emphasizes the need for improved ocean observations and modeling at eddy scales

Use of Microwave Radiometry to Monitor Thermal Denaturation of Albumin

This study monitored thermal denaturation of albumin using microwave radiometry. Brightness Temperature, derived from Microwave Emission (BTME) of an aqueous solution of bovine serum albumin (0.1 mM) was monitored in the microwave frequency range 3.8–4.2 GHz during denaturation of this protein at a temperature of 56°C in a conical polypropylene cuvette. This method does not require fluorescent or radioactive labels. A microwave emission change of 1.5–2°C in the BTME of aqueous albumin solution was found during its denaturation, without a corresponding change in the water temperature. Radio thermometry makes it possible to monitor protein denaturation kinetics, and the resulting rate constant for albumin denaturation was 0.2 ± 0.1 min−1, which corresponds well to rate constants obtained by other methods

New Details of HCV NS3/4A Proteinase Functionality Revealed by a High-Throughput Cleavage Assay

Background: The hepatitis C virus (HCV) genome encodes a long polyprotein, which is processed by host cell and viral proteases to the individual structural and non-structural (NS) proteins. HCV NS3/4A serine proteinase (NS3/4A) is a noncovalent heterodimer of the N-terminal,,180-residue portion of the 631-residue NS3 protein with the NS4A co-factor. NS3/ 4A cleaves the polyprotein sequence at four specific regions. NS3/4A is essential for viral replication and has been considered an attractive drug target. Methodology/Principal Findings: Using a novel multiplex cleavage assay and over 2,660 peptide sequences derived from the polyprotein and from introducing mutations into the known NS3/4A cleavage sites, we obtained the first detailed fingerprint of NS3/4A cleavage preferences. Our data identified structural requirements illuminating the importance of both the short-range (P1–P19) and long-range (P6-P5) interactions in defining the NS3/4A substrate cleavage specificity. A newly observed feature of NS3/4A was a high frequency of either Asp or Glu at both P5 and P6 positions in a subset of the most efficient NS3/4A substrates. In turn, aberrations of this negatively charged sequence such as an insertion of a positively charged or hydrophobic residue between the negatively charged residues resulted in inefficient substrates. Because NS5B misincorporates bases at a high rate, HCV constantly mutates as it replicates. Our analysis revealed that mutations do not interfere with polyprotein processing in over 5,000 HCV isolates indicating a pivotal role of NS3/4A proteolysis in the viru

Tunneling-assisted impact ionization fronts in semiconductors

We propose a novel type of ionization front in layered semiconductor structures. The propagation is due to the interplay of band-to-band tunneling and impact ionization. Our numerical simulations show that the front can be triggered when an extremely sharp voltage ramp ($\sim 10 {\rm kV/ns}$) is applied in reverse direction to a Si $p^+-n-n^+-$structure that is connected in series with an external load. The triggering occurs after a delay of 0.7 to 0.8 ns. The maximal electrical field at the front edge exceeds $10^6 {\rm V/cm}$. The front velocity $v_f$ is 40 times faster than the saturated drift velocity $v_s$. The front passes through the $n-$base with a thickness of $100 {\mu m}$ within approximately 30 ps, filling it with dense electron-hole plasma. This passage is accompanied by a voltage drop from 8 kV to dozens of volts. In this way a voltage pulse with a ramp up to $500 {\rm kV/ns}$ can be applied to the load. The possibility to form a kilovolt pulse with such a voltage rise rate sets new frontiers in pulse power electronics.Comment: 12 pages, 6 figure

Randomness in Classical Mechanics and Quantum Mechanics

The Copenhagen interpretation of quantum mechanics assumes the existence of the classical deterministic Newtonian world. We argue that in fact the Newton determinism in classical world does not hold and in classical mechanics there is fundamental and irreducible randomness. The classical Newtonian trajectory does not have a direct physical meaning since arbitrary real numbers are not observable. There are classical uncertainty relations, i.e. the uncertainty (errors of observation) in the determination of coordinate and momentum is always positive (non zero). A "functional" formulation of classical mechanics was suggested. The fundamental equation of the microscopic dynamics in the functional approach is not the Newton equation but the Liouville equation for the distribution function of the single particle. Solutions of the Liouville equation have the property of delocalization which accounts for irreversibility. The Newton equation in this approach appears as an approximate equation describing the dynamics of the average values of the position and momenta for not too long time intervals. Corrections to the Newton trajectories are computed. An interpretation of quantum mechanics is attempted in which both classical and quantum mechanics contain fundamental randomness. Instead of an ensemble of events one introduces an ensemble of observers.Comment: 12 pages, Late

Laser doppler spectrum decomposition applied in diagnostics of microcirculatory disturbances

Laser Doppler flowmetry (LDF) is widely used to study blood microcirculation in the skin. However, during tradition signal processing based on the integral estimations of the power spectrum of detector photocurrent, the significant part of the information about the skin blood ow is lost. In this study, we propose to analyse the distribution of the blood perfusion over the Doppler shift frequencies, which correlate with the RBC velocity. This approach provides localisation of the blood ow oscillations in different subranges of the Doppler shift. The method applied together with the wavelet analysis has been tested in healthy volunteers and patients with psoriasis on the unaffected surface of the skin. It was revealed, that the significant difference in the amplitude of myogenic oscillations is allocated in the region of the low frequency Doppler shift (1-200 Hz). This frequency region can be associated with the signal from slow components of the skin microcirculation, that can point out on a different state of the lymphatic system of the skin in psoriasis