”Fulminant” acute pancreatitis: diagnosis, prognosis, treatment

Aim: improving the results treatment of patients with severe acute pancreatitis by early diagnosis fulminant course of the disease and development of individualized treatment tactics based on early surgical interventions with perioperative extracorporeal detoxificationMaterials and methods: In research analyzed the treatment of 232 patients with severe acute pancreatitis: 175 patients were evaluated retrospectively (control group), 57 were included in a prospective study (main group). The severity of the disease was studied using integral scales, necrosis of the pancreas (its localization, depth) and the prevalence of parapancreatitis (gradations according to Ishikawa et al.) - according to CT data. The tactics of treatment at the retrospective stage of the study was based on the current Clinical Recommendations, at the prospective stage - on the developed signs of a "fulminant" course of the disease and included early operations with perioperative extracorporeal detoxification.Results: Criteria for a fulminant course of severe acute pancreatitis were found in 41 (23%) of 175 and 24 (42%) of 57 patients. According to the scale values (APACHE II ≥ 16 Ranson ≥ 8, SOFA ≥ 7 points) in the first 48 hours from the onset of the disease, the presence of aseptic enzymatic peritonitis, the depth of necrosis in the region of the head and body of the pancreas ≥50%, intra-abdominal hypertension of the III-IV degree, significant differences with similar indicators in 134 and 33 patients with severe acute pancreatitis. With fulminant course in the control and main groups, all 5 patients who received only conservative treatment died, 33 (86.8%) and 9 (40.9%) after operations, χ2 = 13.32, p<0.001. Mortality in severe acute pancreatitis, excluding patients with fulminant course, was comparable in the groups, being 15.7% and 15.2%, χ2 = 0.450, p> 0.05.Conclusion: Patients with severe acute pancreatitis represent a heterogeneous group. The morphological substrate of "fulminant" pancreatitis is deep (more than 50%) necrosis with localization in the head and body of the pancreas and widespread parapancreatitis. The developed individualized approach to treatment allows predicting an unfavorable course in the first 48 hours after the onset of the disease. Early operations in the nature of detoxification, decompression and drainage interventions, with perioperative use of extracorporeal detoxification methods allowed to reduce mortality from 86.8% to 40.9%.

Persistence analysis in convective turbulence

&lt;p&gt;Persistence is defined as the probability that the local value of a fluctuating field remains at a particular state for a certain amount of time, before being switched to another state. The concept of persistence has been found to have many diverse practical applications, ranging from non-equilibrium statistical mechanics to financial dynamics to distribution of time scales in turbulent flows and many more. In this study, we carry out a detailed analysis of the statistical characteristics of the persistence probability density functions (PDFs) of velocity and temperature fluctuations in the surface layer of a convective boundary layer, using a field-experimental dataset. Our results demonstrate that for the time scales smaller than the integral scales, the persistence PDFs of turbulent velocity and temperature fluctuations display a clear power-law behavior, associated with a self-similar eddy cascading mechanism. Apart from that, we show that the effects of non-Gaussian temperature fluctuations act only at those scales which are larger than the integral scales, where the persistence PDFs deviate from the power-law and drop exponentially.&lt;/p&gt;&lt;p&gt;To advance our knowledge, we also investigate how the turbulent structures associated with velocity and temperature fluctuations interact to produce the emergent flux signatures, a vexing problem but of paramount importance for a plethora of applications, encompassing both engineering and Earth sciences. We discover that the persistence patterns for heat and momentum fluxes are widely different. Moreover, we uncover the power-law scaling and length scales of turbulent motions that cause this behavior. Furthermore, by separating the phases and amplitudes of flux events, we explain the origin and differences between heat and momentum transfer efficiencies in convective turbulence. In summary, our findings provide a new understanding of the connection between flow organization and flux generation mechanisms, two cornerstones of turbulence research.&lt;/p&gt;

INDICATORS OF ORGAN DEFICIENCY DEVELOPMENT IN ACUTE PANCREATITIS

Today, acute pancreatitis remains one of the three leading reasons for hospitalization of patients in emergency departments. Despite the fact that the material and technical base of medical institutions is improving every year, it is not always possible to timely and adequately assess the severity of the condition of patients with acute pancreatitis. Underestimation of the severity of the condition can end up sadly for the patient, therefore, patients with severe acute pancreatitis should be identified in the early stages of the disease. To predict the severe course of acute pancreatitis in the early stages of the disease, it is necessary to take into account such risk factors as age, concomitant diseases, body mass index, as well as clinical and laboratory markers of severity: hematocrit, neutrophil-lymphocyte coefficient, distribution of erythrocytes by volume, glucose, urea and data from integral scales. Markers such as respiratory failure and oliguria diagnosed upon admission, as well as the level of lactate dehydrogenase, bicarbonates and acid-base balance of the blood, can also be considered prognostically significant markers of severe course. Early identification of patients with an increased risk of complications and their timely adequate therapy can improve treatment outcomes and reduce mortality rates.

Influence of turbulence integral length scale on aerostatic coefficients of bridge sections

This study investigates the influence of turbulence on the aerostatic coefficients of typical bridges by obtaining force measurements via the simulation of turbulence in wind tunnels. The traditional simulation method for turbulence based on spires and grilles cannot be employed for the accurate simulation of the large integral scale of turbulence in an actual wind field. Thus, in this study, the turbulence integral length scale was effectively increased using an active control grid. The wind fields of different turbulence integral scales were generated by controlling the vibration frequency of the active control grid. The aerostatic coefficients of five typical bridge sections (single-box girder, twin-box girder, truss girder, edge girder, and edge-box girder) were measured under turbulent and uniform flow. The test results were compared and analyzed, which revealed that the drag coefficients increased in accordance with a decrease in the reduced turbulence integral length scale, and they were lower under turbulent flow than under uniform flow.

EARLY CLINICAL MARKERS OF SEVERITY OF ACUTE NECROTIC PANCREATITIS

Summary. Acute necrotic pancreatitis carries enough difficulty in diagnosis and treatment. Destructive forms with retroperitoneal tissue damage cause lethality up to 70 %. The aim was to establish early clinical markers of disease severity. Material and methods. The results of surgical treatment of 120 patients with acute pancreatitis were analyzed. Patients were divided into groups: first group – 40 patients without parapancreatitis; second group — 80 patients with parapancreatitis. Peripheral blood reaction, main biochemical indicators, blood electrolytes, general condition by integral scales were evaluated in this groups. Results and discussion. On the admission day, the levels of erythrocytes and hemoglobin in patients in both groups were within normal limits. All patients had leukocytosis. All subjects had high LII rates. In the dynamics of treatment leukocytosis significantly decreased in the second group. Changes in clinical blood tests, urinalysis, ALT, AST, bilirubin, urea, creatinine were not significant. Conclusions. Postoperative mortality was 27.2 %. 67 % of patients had parapancreatitis. It was revealed, that reliable early markers of severity of acute necrotizing pancreatitis are: level of WBC, leucocyte intoxication index, intoxication indicator, organism`s resistance index, reactive neutrophilic response, C-reactive protein and level of calcium. It was proved, that evaluation of patient`s condition by scales ASSES, SAPS II and Ranson objectively reflects the patient`s condition during the course of treatment.

Assessment of turbulent scales over complex terrain in central Spain

&lt;p&gt;In this work, a micrometeorological assessment of Atmospheric Boundary Layer paremeters is carried out in order to determine the characteristic turbulent scales over complex terrain in the Sierra de Guadarrama, a range in central Spain. Observational data series of temperature and wind velocity measured at high frecuency (10 Hz) are available. These data come from two different stations located in the Bosque de La Herrer&amp;#237;a and belonging to GuMNet (2020) (Guadarrama Monitoring Network).&lt;/p&gt;&lt;p&gt;Integral scales, both time and spatial, have been determined for different atmospheric conditions, defined by parameters such as wind direction or stability of stratification. Also, energy cascade phenomenon occurence is assessed. In order to carry this out, different time series analysis tools are used, such as autocorrelation functions in time, and normalised power spectra or wavelets. Results obtained are compared with previous works.&lt;/p&gt;&lt;p&gt;In general, results show that under no synoptic forcing there is a clear dependency on diurnal cycle, giving rise to the development of big integral scales at nighttime, while they are small during the day. When synoptic forcing prevails, the scales are also small, both at daytime and nighttime. Moreover, a correlation patterns method has been implemented for scales obtained at two different heights (4 and 8 meters) on the one hand and at two locations on the other. In the first case, integral scales are highly correlated, exceeding the threshold of 0.5. In the second case, temporal scales show high correlation values, but spatial ones do not. &amp;#160;In addition, the slopes of the spectra in the inertial subrange have&amp;#160; been obtained and compared to those over homogeneous terrain (Kaimal et al., 1972), getting similar results for velocity turbulent components but not in case of vertical kinematic momentum and heat fluxes.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;&lt;strong&gt;References&lt;/strong&gt;&lt;/p&gt;&lt;p&gt;GuMNet: Guadarrama Monitoring Network (UCM), https://www.ucm.es/gumnet/, 2020.&lt;/p&gt;&lt;p&gt;Kaimal, J. C., Wyngaard, J. C., Izumi, Y., and Cot&amp;#233;, O. R.: Spectral characteristics of surface- layer turbulence, Quart. J. R. Met. Soc., 98, 563&amp;#8211;589, 1972.&lt;/p&gt;

Source Flow in Heterogeneous Aquifers with Application to Hydraulic Tomography

&lt;p&gt;Enhanced spreading of contaminants by groundwater (macrodispersion) is governed by advection by the velocity field, whose spatial variability is caused by the heterogeneity of the hydraulic conductivity K. Characterization of K distribution in space is a major topic of research. While considerable knowledge has been accumulated for natural gradient flows, hydraulic tomography methods have been forwarded only recently. A typical setup consists of short segments of a well through which water is pumped (injected) and the head H response is measured by pressure transducers along observation piezometers at different distances and elevations. Attempts in the past were done mainly to derive K from measured H&amp;#160;&amp;#160;by numerical inversion of the flow equation accordingly to a global optimality condition. The present study considers stochastic hydraulic tomography by which measured H are employed in order to identify the statistical parameters of the log-conductivity Y= ln K field (mean, variance, integral scales). As a first step we investigate and present the solution of the steady flow equations relating &amp;#160;H statistical moments to those of the K field for the strongly nonuniform source flow, which approximates the main constitutive element of the tomographic setup. This is achieved by numerical simulations for values of the Y variance up to 4 and the derivation of type curves which helps in the identification of K statistics. Application to identification of logconductivity moments for a hydraulic tomography setup is illustrated by a synthetic example.&lt;/p&gt;

Wave-Turbulence Decomposition Methods Applied to Tidal Energy Site Assessment

High levels of turbulence have been proven to substantially increase the blade loadings on tidal turbines, outlining the need of properly characterizing turbulence parameters in tidal energy sites. The presence of long surface gravity waves may cause a significant bias on the estimation of these parameters, which requires wave-turbulence decomposition methods that are currently missing from guidelines. Here, three techniques of decomposing wave and turbulence are tested: the stopband filter (SB), moving average filter (MA), and synchrosqueezing wavelet transform (SWT). The study site, Banks Strait, Tasmania, is a 16 km wide channel that presents high potential for tidal energy generation. Wave peak periods at the study site were found to vary mostly between 7 and 12 s, with maximum exceeding 15 s. Turbulence intensities (TI), turbulent kinetic energy (TKE), and integral scales are quantified. Our results indicate differences between the estimates obtained from each method. The MA highly underestimates turbulence, resulting in TI values which were nearly 50% lower than those obtained from other decomposition methods. While TI and TKE estimated from the SB and the SWT techniques are quite similar, integral length scales are considerably underestimated by the SB. These findings reveal that the SWT is a more reliable method because of the more accurate estimates of turbulence parameters and indicate the need of establishing guidelines which address wave-turbulence decomposition in tidal stream energy site assessments. Despite having shown to be quite a versatile technique, further investigation of its applicability in data from other prospective tidal energy sites is necessary to fully assess the generality of the SWT technique.