A Method for Magma Viscosity Assessment by Lava Dome Morphology

Lava domes form when a highly viscous magma erupts on the surface. Several types of lava dome morphology can be distinguished depending on the flow rate and the rheology of magma: obelisks, lava lobes, and endogenic structures. The viscosity of magma nonlinearly depends on the volume fraction of crystals and temperature. Here we present an approach to magma viscosity estimation based on a comparison of observed and simulated morphological forms of lava domes. We consider a two-dimensional axisymmetric model of magma extrusion on the surface and lava dome evolution, and assume that the lava viscosity depends only on the volume fraction of crystals. The crystallization is associated with a growth of the liquidus temperature due to the volatile loss from the magma, and it is determined by the characteristic time of crystal content growth (CCGT) and the discharge rate. Lava domes are modeled using a finite-volume method implemented in Ansys Fluent software for various CCGTs and volcanic vent sizes. For a selected eruption duration a set of morphological shapes of domes (shapes of the interface between lava dome and air) is obtained. Lava dome shapes modeled this way are compared with the observed shape of the lava dome (synthesized in the study by a random modification of one of the calculated shapes). To estimate magma viscosity, the deviation between the observed dome shape and the simulated dome shapes is assessed by three functionals: the symmetric difference, the peak signal-to-noise ratio, and the structural similarity index measure. These functionals are often used in the computer vision and in image processing. Although each functional allows to determine the best fit between the modeled and observed shapes of lava dome, the functional based on the structural similarity index measure performs it better. The viscosity of the observed dome can be then approximated by the viscosity of the modeled dome, which shape fits best the shape of the observed dome. This approach can be extended to three-dimensional case studies to restore the conditions of natural lava dome growth

A Method for Magma Viscosity Assessment by Lava Dome Morphology

Abstract: Lava domes form when a highly viscous magma erupts on the surface. Several types of lava dome morphology can be distinguished depending on the flow rate and the rheology of magma: obelisks, lava lobes, and endogenic structures. The viscosity of magma nonlinearly depends on the volume fraction of crystals and temperature. Here we present an approach to magma viscosity estimation based on a comparison of observed and simulated morphological forms of lava domes. We consider a two-dimensional axisymmetric model of magma extrusion on the surface and lava dome evolution, and assume that the lava viscosity depends only on the volume fraction of crystals. The crystallization is associated with a growth of the liquidus temperature due to the volatile loss from the magma, and it is determined by the characteristic time of crystal content growth (CCGT) and the discharge rate. Lava domes are modeled using a finite-volume method implemented in Ansys Fluent software for various CCGTs and volcanic vent sizes. For a selected eruption duration a set of morphological shapes of domes (shapes of the interface between lava dome and air) is obtained. Lava dome shapes modeled this way are compared with the observed shape of the lava dome (synthesized in the study by a random modification of one of the calculated shapes). To estimate magma viscosity, the deviation between the observed dome shape and the simulated dome shapes is assessed by three functionals: the symmetric difference, the peak signal-to-noise ratio, and the structural similarity index measure. These functionals are often used in the computer vision and in image processing. Although each functional allows to determine the best fit between the modeled and observed shapes of lava dome, the functional based on the structural similarity index measure performs it better. The viscosity of the observed dome can be then approximated by the viscosity of the modeled dome, which shape fits best the shape of the observed dome. This approach can be extended to three-dimensional case studies to restore the conditions of natural lava dome growth. © 2021, The Author(s).We are grateful to two anonymous reviewers for their constructive comments. Numerical experiments were carried out on the Uran computing cluster (Institute of Mathematics and Mechanics, Ural Branch of the Russian Academy of Sciences, Yekaterinburg). The work was supported by the Russian Science Foundation (project no. 19-17-00027)

Lipidomic profile of seminal plasma in non-obstructive azoospermia with sperm maturation arrest

Introduction. The difference between obstructive and non-obstructive azoospermia with sperm maturation arrest is important for the choice of treatment tactics and adequate counseling of a married couple.Purpose of the study. The study aimed to assess the semen lipid profile in patients with sperm maturation arrest. Materials and methods. Samples of seminal plasma for lipid composition of 24 men with normozoospermia and 64 men with azoospermia were studied. Patients with azoospermia underwent microdissection testicular biopsy followed by the detection of testicular tissue pathology. Lipid extracts were analyzed by liquid chromatography with mass spectrometry. Lipid data were compared with the results of pathomorphological studies.Results. Comparison of two groups revealed a statistically significant concentration differences for 22 lipids detected in positive-ion mode and 11 lipids detected in negative-ion mode. Those lipids mainly belong to the classes hexosylceramides, sphingomyelins and phosphatidylcholines — simple ethers and oxidized lipids. In multivariate analysis, the following lipids were found to be statistically significant predictors of sperm maturation arrest: PC 16: 0_22: 6 lipid (β-coefficient: -0.73; 95% confidence interval (95% CI): -1.42 to -0.27; odds ratio (OR): 0.48; OR CI: 0.24 to 0.76; Wald's test: -2.58; p = 0.01), SM d20: 1/22:2 lipid (β-coefficient 4.96; 95% CI 2.29 to 9.13; OR: 142.31; OR CI: 9.90 to 9.22^103; Wald's test: 2.93; p = 0.003); PG 20:3_22: 6 lipid (β-coefficient 2.52; 95% CI 1.13 to 4.49; OR: 12.37; OR CI: 3.10 to 89.27; Wald's test: 3.02; p = 0.002); PC O- 16: 1/16:0 lipid (β-coefficient 1.96; 95% CI -4.12 to 0.27; OR: 0.14; OR CI: 0.02 to 0.76; Wald's test: -2.05; p = 0.04). The prediction model characteristics of sperm maturation arrest, obtained during cross-validation in the positiveion mode composed: sensitivity 91%, specificity 85%; in negative-ion mode: sensitivity 75%; specificity 81%.Conclusions. Even though early stages of spermatogenesis are equally preserved in both fertile men and men with homogeneous sperm maturation arrest, the semen in the studied group of patients differed in its lipid profile. Patients with non-obstructive azoospermia, associated with meiosis arrest, may have unique lipidomic characteristics of seminal plasma, which in the future will make it possible to differentiate various variants of severe male infertility using non-invasive methods

The course of fluorine intoxication

The purpose of the study is to study of the features of the modern clinic of chronic fluorine intoxication in workers.Цель исследования – изучение особенностей современной клиники хронической фтористой интоксикации у рабочих, подвергавшихся действию фтора

СРАВНИТЕЛЬНЫЙ ПРОТЕОМНЫЙ АНАЛИЗ КОНДЕНСАТА ВЫДЫХАЕМОГО ВОЗДУХА У ПАЦИЕНТОВ С РАКОМ ЛЕГКОГО МЕТОДОМ МАСС-СПЕКТРОМЕТРИИ ВЫСОКОГО РАЗРЕШЕНИЯ

Analysis of exhaled breath condensate (EBC) is a promising non-invasive method to diagnose respiratory diseases. Most researchers emphasize the importance of proteomic analysis of EBC for early diagnosis of certain respiratory diseases including lung cancer. This study was aimed at identification of potential biomarkers of neoplastic disorders in EBC of patients with lung cancer using high-performance liquid chromatography and high resolution mass-spectrometry. The study involved 26 patients with lung carcinoma (21 males, 5 females, mean age 57 ± 12 years) and 23 healthy non-smokers (19 males, 4 females, mean age 30 ± 7 years). EBC samples were collected using a disposable portable condenser R-Tube. The most of proteins identified (65 %) belonged to keratin family including type 1 (1; 2; 5 and 6А) and type 2 (9; 10; 14; 16 and 17) cytoskeletal keratins and transport proteins (albumin, lipocalin-1). Keratin family proteins (5, 6 and 14) prevailed in lung cancer patients compared to controls (p < 0.05). Other 6 proteins were also detected predominantly in lung cancer patients including b-subunit and a-subunit of haemoglobin, nuclear ubiquitous casein (NUCKS), high-mobility group proteins (HMG-I/HMG-Y), and lactoferrin. Most of these proteins could be used as a diagnostic panel to detect lung cancer. Further investigations are needed to estimate diagnostic values of these biomarkers and their role in pathogenesis of lung cancer.Анализ конденсата выдыхаемого воздуха (КВВ) является перспективным неинвазивным методом оценки состояния дыхательной системы. Многие исследователи указывают на важность анализа протеома КВВ для раннего выявления заболеваний респираторного тракта, в т. ч. диагностики рака легкого (РЛ). В исследовании, в которое были включены 2 группы доноров: основная – больные РЛ (n = 26; 21 мужчина, 5 женщин; средний возраст – 56,5 ± 11,5 года) и контрольная (n = 23; 19 мужчин, 4 женщины; средний возраст – 30,0 ± 7,0 года) – здоровые некурящие добровольцы, у больных РЛ методом высокоэффективной жидкостной хроматографии и тандемной масс-спектрометрии была проведена идентификация потенциальных белков-онкомаркеров в КВВ. Образцы КВВ были собраны с помощью одноразового портативного конденсора R-Tube. Основную часть (65 %)  идентифицированных белков составили белки кератиновой группы, в т. ч. кератины цитоскелетные 1-го (1, 2, 5 и 6А) и 2-го (9, 10, 14, 16 и 17) типов, а также группа транспортных белков (альбумин, липокалин-1). Было показано, что группа кератинов (5, 6 и 14) более значительно выражена (р < 0,05) у онкологических больных по сравнению со здоровым контролем. Также 6 белков были преимущественно определены в КВВ доноров основной группы, в т. ч. b- и a-субъединицы гемоглобина, ядерный убиквитиновый казеин (NUCKS), белки группы высокой мобильности (HMG-I/HMG-Y), лактоферрин. Большинство выявленных белков может быть предложено в качестве панели для диагностики РЛ. Однако необходимы дальнейшие исследования для определения диагностической значимости предложенных биомаркеров и их роли в патогенезе РЛ

Educational needs and preferences of young European clinicians and physician researchers working in the field of rheumatology

Funding Information: CB: Grant BE 5191/1-1 of the Deutsche Forschungsgemeinschaft.Objectives: To understand the educational needs and preferences of young clinicians and physician researchers in the field of rheumatology in Europe. Methods: An international online survey was performed as a joint venture of ESCET and EMEUNET. The survey assessed the acceptance of and the access to the current European League Against Rheumatism (EULAR) educational portfolio, as well as the unmet educational needs and learning preferences among individuals below the age of 40 years working in rheumatology in Europe. Results: Among 568 European clinicians and physician researchers, 65% indicated that the existing EULAR educational portfolio adequately covers their educational needs. Within the EULAR portfolio, the online course on rheumatic diseases and the postgraduate course were the most appreciated. Participants were very much in favour of new educational courses on imaging techniques, and 63% of participants indicated a particular interest in musculoskeletal ultrasound. A strong interest in refresher (60%) and general review (55%) courses was observed. Lack of funding was considered the major obstacle to participating in existing EULAR programmes. Finally, participants showed diverse preferences regarding learning modalities with common interests in live courses and conferences. Conclusions: EULAR's training opportunities are well appreciated among young clinicians and physician researchers in rheumatology. The results from this survey will help to develop EULAR's future educational portfolio.publishersversionPeer reviewe

Synthesis of γ-, δ-, and ε-Lactams by Asymmetric Transfer Hydrogenation of N-(tert-Butylsulfinyl)iminoesters

Highly enantiomerically enriched γ- and δ-lactams have been prepared by a simple and very efficient procedure that involves the asymmetric transfer hydrogenation of N-(tert-butylsulfinyl)iminoesters followed by desulfinylation of the nitrogen atom and spontaneous cyclization to the desired lactams during the basic workup procedure. Five- and six-membered ring lactams bearing aromatic, heteroaromatic, and aliphatic substituents have been obtained in very high yields and ee’s up to >99%. A slight modification of the procedure also allowed the preparation of ε-lactams in good yields and very high enantioselectivities. Both enantiomers of the final lactams could be prepared with equal efficiency by changing the absolute configuration of the sulfinyl chiral auxiliary

Glycosylation of Erythrocyte Spectrin and Its Modification in Visceral Leishmaniasis

Using a lectin, Achatinin-H, having preferential specificity for glycoproteins with terminal 9-O-acetyl sialic acid derivatives linked in α2-6 linkages to subterminal N-acetylgalactosamine, eight distinct disease-associated 9-O-acetylated sialoglycoproteins was purified from erythrocytes of visceral leishmaniaisis (VL) patients (RBCVL). Analyses of tryptic fragments by mass spectrometry led to the identification of two high-molecular weight 9-O-acetylated sialoglycoproteins as human erythrocytic α- and β-spectrin. Total spectrin purified from erythrocytes of VL patients (spectrinVL) was reactive with Achatinin-H. Interestingly, along with two high molecular weight bands corresponding to α- and β-spectrin another low molecular weight 60 kDa band was observed. Total spectrin was also purified from normal human erythrocytes (spectrinN) and insignificant binding with Achatinin-H was demonstrated. Additionally, this 60 kDa fragment was totally absent in spectrinN. Although the presence of both N- and O-glycosylations was found both in spectrinN and spectrinVL, enhanced sialylation was predominantly induced in spectrinVL. Sialic acids accounted for approximately 1.25 kDa mass of the 60 kDa polypeptide. The demonstration of a few identified sialylated tryptic fragments of α- and β-spectrinVL confirmed the presence of terminal sialic acids. Molecular modelling studies of spectrin suggest that a sugar moiety can fit into the potential glycosylation sites. Interestingly, highly sialylated spectrinVL showed decreased binding with spectrin-depleted inside-out membrane vesicles of normal erythrocytes compared to spectrinN suggesting functional abnormality. Taken together this is the first report of glycosylated eythrocytic spectrin in normal erythrocytes and its enhanced sialylation in RBCVL. The enhanced sialylation of this cytoskeleton protein is possibly related to the fragmentation of spectrinVL as evidenced by the presence of an additional 60 kDa fragment, absent in spectrinN which possibly affects the biology of RBCVL linked to both severe distortion of erythrocyte development and impairment of erythrocyte membrane integrity and may provide an explanation for their sensitivity to hemolysis and anemia in VL patients