Spores of puffball fungus Lycoperdon pyriforme as a reference standard of stable monodisperse aerosol for calibration of optical instruments

Advanced air quality control requires real-time monitoring of particulate matter size and concentration, which can only be done using optical instruments. However, such techniques need regular calibration with reference samples. In this study, we suggest that puffball fungus (Lycoperdon pyriforme) spores can be utilized as a reference standard having a monodisperse size distribution. We compare the Lycoperdon pyriforme spores with the other commonly used reference samples, such as Al2O3 powder and polystyrene latex (PSL) microspheres. Here we demonstrate that the puffball spores do not coagulate and, thus, maintain the same particle size in the aerosol state for at least 15 minutes, which is enough for instrument calibration. Moreover, the puffball mushrooms can be stored for several years and no agglomeration of the spores occurs. They are also much cheaper than other calibration samples and no additional devices are needed for aerosol generation since the fungal fruiting body acts as an atomizer itself. The aforementioned features make the fungal spores a highly promising substance for calibration and validation of particle size analyzers, which outperforms the existing, artificially produced particles for aerosol sampling. Furthermore, the L. pyriforme spores are convenient for basic research and development of new optical measurement techniques, taking into account their uniform particle size and absent coagulation in the aeroso

Making big steps in trajectories

We consider the solution of initial value problems within the context of hybrid systems and emphasise the use of high precision approximations (in software for exact real arithmetic). We propose a novel algorithm for the computation of trajectories up to the area where discontinuous jumps appear, applicable for holomorphic flow functions. Examples with a prototypical implementation illustrate that the algorithm might provide results with higher precision than well-known ODE solvers at a similar computation time

Specific features of Bazhenov suite sediments in south-eastern Nurolsk sedimentary basin (Tomsk Oblast)

The specific sediment features in Georgiev (J[3]kmgr), Bazhenov (J3vbg) and Kulomzin (K1bkl) suites, exposed by drilling in the S-E Nurolsk depression (Tomsk Oblast), were defined and described via petrographic, X-ray diffraction and fluorescence-microscopy analysis methods. The classification of agrillites was identified, the structure-texture features, composition, voids and bitumen types and their distribution were determined. It was defined that Bazhenov suite argillites are characteristic of fine-dispersion, high biogenic silica content and scattered organic matter, enriched multi-composite syngenetic bitumen (from light to resin-asphaltine), as well as fractured surface where the migration of light bitumen occurs

Black-hole concept of a point-like nucleus with supercritical charge

The Dirac equation for an electron in the central Coulomb field of a point-like nucleus with the charge greater than 137 is considered. This singular problem, to which the fall-down onto the centre is inherent, is addressed using a new approach, based on a black-hole concept of the singular centre and capable of producing cut-off-free results. To this end the Dirac equation is presented as a generalized eigenvalue boundary problem of a self-adjoint operator. The eigenfunctions make complete sets, orthogonal with a singular measure, and describe particles, asymptotically free and delta-function-normalizable both at infinity and near the singular centre $r=0$. The barrier transmission coefficient for these particles responsible for the effects of electron absorption and spontaneous electron-positron pair production is found analytically as a function of electron energy and charge of the nucleus. The singular threshold behaviour of the corresponding amplitudes substitutes for the resonance behaviour, typical of the conventional theory, which appeals to a finite-size nucleus.Comment: 22 pages, 5 figures, LATEX requires IOPAR

Relativistic theory of inverse beta-decay of polarized neutron in strong magnetic field

The relativistic theory of the inverse beta-decay of polarized neutron, $\nu _{e} + n \to p + e ^{-}$, in strong magnetic field is developed. For the proton wave function we use the exact solution of the Dirac equation in the magnetic filed that enables us to account exactly for effects of the proton momentum quantization in the magnetic field and also for the proton recoil motion. The effect of nucleons anomalous magnetic moments in strong magnetic fields is also discussed. We examine the cross section for different energies and directions of propagation of the initial neutrino accounting for neutrons polarization. It is shown that in the super-strong magnetic field the totally polarized neutron matter is transparent for neutrinos propagating antiparallel to the direction of polarization. The developed relativistic approach can be used for calculations of cross sections of the other URCA processes in strong magnetic fields.Comment: 41 pages in LaTex including 11 figures in PostScript, discussion on nucleons AMM interaction with magnetic field is adde

The role of herpes virus infection in development of arrhythmias in children

ECG' peculiarities and titers of anticardial antibodies (ACAB) were studied in 44 children with herpes virus infection: 63% of patients were infected by herpes virus type IV, V, VI; the rest ones - herpes virus type I,II in addition. ECG has revealed dysfunction of sinus node, conductive disturbances and changes of repolarization in 1/3 of children, 20% of patients has signs of myocardial electric instability. Part of children has increased titers of ACAB to conductive system and cardiomyocytes

Cardiovascular status and echocardiographic changes in survivors of COVID-19 pneumonia three months after hospital discharge

Coronavirus disease 2019 (COVID-19) affects the function of all organs and systems. Today, studying the effect of COVID-19 on cardiovascular system, including on echocardiographic characteristics, is relevant.Aim. To study the prevalence of symptoms, cardiovascular disease and changes in echocardiographic data in persons after documented COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients after documented COVID-19 pneumonia. The patients underwent a comprehensive examination during hospitalization and 3 months±2 weeks after discharge from the hospital. The mean age of participants was 47±16 years (19-84 years); 49% of subjects were women.Results. Three months after hospital discharge, the symptoms persisted in 86% of examined patients. There were significant echocardiographic changes as follows: a decrease in LV end-diastolic, end-systolic and stroke volume (113,8±26,8 ml vs 93,5±29,4 ml; 37,7±13,0 ml vs 31,3±14,2 ml; 77,2±17,8 ml vs 62,2±18,7 ml, respectively, p<0,001 for all). The right ventricular anteroposterior dimension and the pulmonary trunk diameter decreased over time (26,0 [24,0-29,3] mm vs 25,0 [23,0-27,0] mm, p=0,004; 21,7±3,6 mm vs 18,7±2,5 mm, p<0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] m><0,001), the same as the pulmonary artery systolic pressure, estimated by tricuspid regurgitation gradient (28,0 [25,0-32,25] mm Hg vs 21,5 [17,0-25,0] mm Hg). The right atrial volume (42,0 [37,0-50,0] ml vs 31,0 [22,0-36,5] ml, p<0,001) a><0,001) and maximum width (36,1±4,6 mm vs 34,5±6,5 mm, p=0,023) decreased, while the right atrial maximum length increased (46,7±6,8 mm vs 48,6±7,1 mm, p=0,021).Conclusion. In survivors of COVID-19 pneumonia three months after hospital discharge, complaints persisted in 86% of cases. Cardiovascular diseases were detected in 52% of participants, including hypertension in 48,1% and coronary artery disease in 15,1%. Compared with in-hospital data, the echocardiographic characteristics improved, which was expressed mainly in a decrease in right heart load

Recent Advances in Σ-definability over Continuous Data Types

The purpose of this paper is to survey our recent research in computability and definability over continuous data types such as the real numbers, real-valued functions and functionals. We investigate the expressive power and algorithmic properties of the language of Sigma-formulas intended to represent computability over the real numbers. In order to adequately represent computability we extend the reals by the structure of hereditarily finite sets. In this setting it is crucial to consider the real numbers without equality since the equality test is undecidable over the reals. We prove Engeler's Lemma for Sigma-definability over the reals without the equality test which relates Sigma-definability with definability in the constructive infinitary language L_{omega_1 omega}. Thus, a relation over the real numbers is Sigma-definable if and only if it is definable by a disjunction of a recursively enumerable set of quantifier free formulas. This result reveals computational aspects of Sigma-definability and also gives topological characterisation of Sigma-definable relations over the reals without the equality test. We also illustrate how computability over the real numbers can be expressed in the language of Sigma-formulas

Echocardiographic characteristics of COVID-19 pneumonia survivors three months after hospital discharge

Coronavirus disease 2019 (COVID-19) is an infectious disease that affects almost all organs and systems. The main target is the respiratory system, but cardiovascular involvement is also common. Today, it is relevant to study the effect of complicated COVID-19 course on the patient’s cardiovascular system after hospital discharge — in particular, echocardiographic parameters.Aim. To study the echocardiographic parameters of patients with COVID-19 pneumonia 3 months after discharge from the hospital.Material and methods. The study included 106 patients with documented COVID-19 pneumonia. Patients underwent a comprehensive examination during hospitalization and 3 months ± 2 weeks after hospital discharge. The mean age of participants was 47±16 years (from 19 to 84 years), while 49% were women.Results. Three months after discharge, the average body mass index of the subjects was 28,2±5,7 kg/m2. Obesity was noted in 37,1%, cardiovascular diseases — in 52%. According to echocardiography, the prevalence of right ventricular (RV) dilatation was 2,9%, a decrease in tricuspid annular plane systolic excursion (TAPSE) — 9,5%, grade ≥2 tricuspid regurgitation — 1,9%, pulmonary hypertension (pulmonary artery systolic pressure >36 mm Hg) — 3,8%. The mean value of RV global longitudinal myocardial strain (GLMS RV) and global longitudinal myocardial strain (GLES RV) was 19,6±4,5 and 20,6±4,6, respectively. We found moderate correlations between GLMS RV and blood flow time through the left ventricular outflow tract (OT) (r=-0,436), through the mitral valve (r=-0,390; both p<0,0001) and through the RVOT (r=-0,348; р=0,004), with cardiac index (CI) (r=0,316; p=0,009), as well as between GLES RV and blood flow time through the LVOT (r=-0,411; p<0,0001) and RVOT (r=-0,300; p=0,005), and with CI (r=0,302; p=0,004). At the same time, the correlation of GLES RV with RV fractional area change (FAC) was weak (r=-0,283; p=0,007), while there was no correlation with the TAPSE. In addition, correlation of GLMS RV with these parameters were not defined.Conclusion. Three months after COVID-19 pneumonia, RV strain parameters were shown to have stronger relationships with time characteristics of flows in LVOT and RVOT, as well as with CI, than with such generally accepted characteristics of RV function as FAC and TAPSE

Возможности применения полисахаридов при лечении ран

The article contains information about applying bio-engineering potential of the natural origin polymer systems, based on biodegradable polysaccharides, for the wound treatment. The unique biological and physicochemical properties of polysaccharides is a promising direction for atraumatic, controlled restoration of the damaged tissues with extensive acquired defects.В статье представлены материалы, отражающие биоинженерный потенциал полимерных систем природного происхождения на основе биодеградируемых полисахаридов, которые могут применяться в создании современных средств для местного лечения ран. Использование уникальных биологических и физико-химических свойств полисахаридов – перспективное направление для атравматичного управляемого восстановления целостности поврежденных тканей при обширных приобретенных дефектах