The change of surface wind in the north Western Siberia since 1966

The statistical analysis of near-surface wind characteristics has been performed in the territory of the North of Western Siberia. The conclusion on wind speed decrease of different intensity for different directions and increase of calmness frequency is made. The maximum changes in wind speed are observed in winter and summer seasons, in transitional seasons these values are lower. The most intensive changes in wind direction frequency occur in summer; the less intensive ones are typical for winter

An accurate simplified data treatment for the initial adsorption kinetics in conditions of laminar convection in a slit: Application to protein adsorption

We present the derivation of a simple approximation for the original expression of the adsorption rate [Langmuir 10 (1994) 3898] in conditions of laminar flow in a slit, to relate the measured initial kinetic constant k with the interfacial kinetic constant ka and the transport-limited Lévêque constant kLev. The same method of derivation is applied here to get a simple approximation of the average kinetic constant 〈k〉 [Biomaterials 20 (1999) 1621]. For the local value, at distance x from the entrance of the slit, we propose k(x)/ka=(u-1)(au-1)/(bu+1), where u=k(x)/kLev, a=0.452, b=-0.625, with a maximal error of 1% in comparison with the exact solution. For the average value over the length of the slit, we propose 〈k〉/ka=(U-1)(AU-1)/(BU+1), where U=〈k〉/〈kLev〉, A=0.203, B=-0.273, with a maximal error of 0.03%. These approximations lead to an easy determination of the adsorption constant and diffusion coefficient D of the solute, as appropriate plots of experimental data provide ka and D2/3 as the intercepts of the curve with the ordinate and abscissa axes, respectively. It is pointed out that the linear approximation k-1=ka -1+kLev -1 would lead to the overestimation of both the diffusion coefficient and adsorption kinetic constant. As an example, the application to the analysis of experimental data for adsorption of α-chymotrypsin onto mica plates is provided. © 2003 Elsevier B.V. All rights reserved

Adsorption of α-chymotrypsin onto mica in laminar flow conditions. Adsorption kinetic constant as a function of tris buffer concentration at pH 8.6

We examined the adsorption kinetics of α-chymotrypsin (pH 8.6,10 -2 to 0.5 M Tris buffer) on muscovite mica in conditions of laminar flow through a slit. The range of buffer concentrations is between two limits: (i) no adsorption in 1 M Tris and (ii) no desorption in 10-3 M Tris. Studying the dependence of adsorption kinetics on the wall shear rate leads to the determination of the interfacial adsorption kinetic constant ka. and the diffusion coefficient. The obtained value for the diffusion coefficient is close to the one expected from the molecular size of α-chymotrypsin. The interfacial adsorption kinetic constant of a-chymotrypsin decreases when ionic strength increases, while the initial desorption constant (over a part of all the adsorbed population) shows the contrary. Although α-chymotrypsin is almost at its isoelectric point, the effect of ionic strength on the adsorption kinetics suggests the importance of electrostatic interactions between the protein and mica. We observed an increase in the adsorption rate, at a surface coverage near 0.14 ug cm-2, for adsorption in 10-2 M Tris and the low wall shear rates (300 s-1). This change in the adsorption rate suggests a structural transition, that we assume again to be due to electrostatic interactions, but between proteins. The large dipole moment of the protein may induce this transition, illustrated here by the ferroelectric/antiferroelectric pattern. The variation of the ζ potential with interfacial concentration seems to be in agreement with such a model

Kinetics of adsorption, desorption, and exchange of α-chymotrypsin and lysozyme on poly(ethyleneterephthalate) tracked film and track-etched membrane

Adsorption kinetics of 125I-radiolabeled α-chymotrypsin at pH 8.6 was studied in a laminar regime between two walls of poly(ethyleneterephthalate) tracked films and membranes. Adsorption kinetics in the presence of solution (10 μg/mL), desorption by rinsing with buffer, and the following exchange of proteins by flowing unlabeled solution were measured. At pH 8.6, α-chymotrypsin is almost neutral and can be mostly removed from the film surface, contrary to positive lysozyme adsorbed at pH 7.4. Results suggest that α-chymotrypsin is irreversibly adsorbed in pores, while desorption and exchange occur on membrane flat faces. A method is proposed to determine adsorption kinetics in the pores. Kinetics of desorption and exchange of α-chymotrypsin from the film surface can be described by stretched exponential functions in the examined time domain with the same exponent, β ≈ 0.62, which does not depend also on the former adsorption duration. However, the mean residence time at the interface is about 2.5 times greater in the presence of only the buffer than that in the presence of solution. This effect could be explained by a fast exchange at the arrival of unlabeled solution for a part of the adsorbed population

Results of a study of soybean source material for breeding purposes under the conditions of Primorsky Territory

Background. A study of the soybean gene pool adapted to the conditions of Primorsky Territory in search of useful agronomic traits is essential for further use in breeding programs.Materials and methods. Soybean accessions from the germplasm collection were tested in 2019–2021 at the Federal Scientific Center of Agricultural Biotechnology of the Far East named after A.K. Chaika. The study included 213 accessions of various origin. Cv. ‘Primorskaya 4’ served as the reference. An objective assessment of the potential of the said research material was made.Results. Three years of experiments resulted in selecting promising soybean genotypes with a set of important agronomic traits for breeding programs. Compared to the reference ‘Primorskaya 4’, an increase of more than 35% in productivity was observed in the cultivars ‘Mestnaya’ (Russia), ‘Jilin’ (China), ‘Montreal’ (France), and ‘XP 977-1.9’ (USA). Cvs. ‘No. 075-2’ (USA), ‘K0152’ (Ukraine), ‘Muzanze Stamm M 4789/74’, ‘SOJA 1065’ and ‘Adsoi’ (Germany) were characterized by earliness (100 days). Cvs. ‘Mestnaya’ and ‘HS Atlas’ may be interesting for breeders due to their highest oil content: 25.9% and 26.0%, respectively. The highest protein content was found in cvs. ‘Zhuravushka’ (39.2%), ‘XN 4’ (41.9%), ‘Torlitsa’ (41.9%) and ‘XP 977-1.9’ (39.5%). Cvs. ‘Pi 6D 4182’, ‘XN 4’, ‘Skelya’ and ‘HS Atlas’ manifested resistance to Septoria brown spot. The results of the assessment for adaptability potential showed that the following cultivars of different origin had the highest resistance to environmental stresses: ‘Primorskaya 4’ (–2.5), ‘Torlitsa’ (–2.0) and ‘Kassidi’ (–3.0)

Self-diffusion of water-ethanol mixture in chitosan membranes obtained by pulsed-field gradient nuclear magnetic resonance technique

The self-diffusion of water and ethanol for crosslinked and uncrosslinked chitosan membranes have been investigated by pulsed-field gradient nuclear magnetic resonance (NMR) spectroscopy. It has been shown that during diffusion processes, water and ethanol are localized in different parts of the chitosan membrane. In the crosslinked membrane, the self-diffusion coefficient for water is higher, but that for ethanol is essentially lower, than those for the uncrosslinked membrane. For this reason, the mobility selectivity is essentially higher in crosslinked membrane as compared to the uncrosslinked. The sorption selectivity are the same for these two types of membranes. | The self-diffusion of water and ethanol for crosslinked and uncrosslinked chitosan membranes have been investigated by pulsed-field gradient nuclear magnetic resonance (NMR) spectroscopy. It has been shown that during diffusion processes, water and ethanol are localized in different parts of the chitosan membrane. In the crosslinked membrane, the self-diffusion coefficient for water is higher, but that for ethanol is essentially lower, than those for the uncrosslinked membrane. For this reason, the mobility selectivity is essentially higher in crosslinked membrane as compared to the uncrosslinked. The sorption selectivity are the same for these two types of membranes

Foeto-foetal transfusion syndrome in dichorionic diamniotic twins: a clinical case

Background. Management of multiple gestation complicated by the foeto-foetal transfusion syndrome is among most intricate modern obstetric issues. The syndrome develops in 10–20% of monochorionic diamniotic twins leading to 80–100% mortality in one or both twins if left uncorrected, especially in early syndrome cases. Although foeto-foetal transfusion usually develops with monochorionic placentae, there are notable exceptions of vascular placental anastomoses reported with dichorionic monozygotic twins. The disease supposedly entails from an imbalanced blood interflow between dichorionic twins due to placental vascular anastomoses.Clinical Case Description. Patient S., 32 yo, visited perinatal diagnostics at the Territorial Perinatal Centre of the Children’s Territorial Clinical Hospital with a preliminary diagnosis: 22 weeks and 5 days’ pregnancy. Dichorionic diamniotic twins. Threat of extremely preterm birth. Two caesarean uterine scars. Gestational diabetes mellitus.Medical files: patient history, pregnancy calendar. Pregnancy was regularly monitored with main ultrasound foetometry, foeto-foetal transfusion dynamics control and Doppler velocimetry.Ultrasonographic signs of abnormal haemodynamics underlying the foeto-foetal transfusion syndrome were detected at the first scan at 11–13 weeks 6 days’ term as collar space thickening in one foetus. Hydramnios in one foetus and oligohydramnios in the other were diagnosed at 28 weeks’ gestation conclusively indicating the foeto-foetal transfusion syndrome. This evidence suggested the formation of placental anastomoses, which was confirmed morphologically in placenta examination.Conclusion. A timely diagnosis and correction of emerging complications allowed prolongation of pregnancy in hospital conditions to 33–34 weeks. Both boys were live-born with Apgar score 7–8

Innovative technologies in the treatment of short bowel syndrome

Introdiction. In recent years, many new technologies for the management of patients with short bowel syndrom (SBS), including SBS-IF (short bowel syndrom with intestinal failor), have appeared. The implemented surgical techniques are aimed at slowing down the progress of intestinal contents (antiperistaltic inserts, the creation of artificial valves in the small intestine, loops or pockets from the small intestine, etc.); surgical elongation of the small intestine (the most common STEP, Bianchy technique); intestinal transplantation. At the same time, when the intestine is shortened to 1.5–2,0 m, the adaptive rearrangements are still able to provide (albeit suppressed), but partially preserved absorption processes (in 80% of cases, the surface of the intestine is sufficient for slow transport of nutrients from the intestine to the blood). Therefore, it is important to increase the efficiency of adaptive rearrangements in any conservative way shown.Аim. Тo evaluate the role of hormonal stimulation of adaptive rearrangements in the residual bowel stump.Materials and methods. Рarameters of the well-known alimentary-volemic diagnosis, assessment of adaptive changes in the gastrointestinal tract (performed by determining citruline and GLP-2, as well as by morphological method). To stimulate the regulation of adaptive processes, a hormone preparation GLP-2 (teduglutide) was used in the nutritional support program.Results. It was shown that the length of the intestinal stump up to 1.5–2.0 m allows for digestive and transport processes due to adaptive rearrangements of the intestinal epithelium. With a super-short intestine, it is advisable to choose surgical methods of correction.Conclusion. For conservative correction of adaptive processes in the intestine, it is advisable to use a GLP-2 hormone preparation, in particular, teduglutide