Search

The NRF2 transcriptional factor is a member of cellular stress response machinery and is activated in response to oxidative stress caused either by cellular homeostasis imbalance or by environmental challenges. NRF2 levels are stringently controlled by rapid and continuous proteasomal degradation. KEAP1 is a specific NRF2 binding protein that acts as a bridge between NRF2 and the E3 ligase Cullin-3. In this study, we examine model cyclic vinyl sulfone derivatives as potential NRF2 activating probes. Previously, we and other authors have found anti-inflammatory properties of these compounds in in vivo models; however, the mechanism of action remained unknown. Here, we show that the naphthohydroquinone derivative LCB1353 efficiently stabilizes NRF2 protein levels and upregulates its target genes. At low 5-10 µM concentrations LCB1353 protects non-small cell lung cancer H1299 cells from ferroptotic death induced by cytotoxic concentrations of RSL3, reducing cell death from 90 % to 5 %. Thus, we suggest that cyclic vinyl sulfones are promising scaffolds for the design of protective molecules for conditions associated with toxic and inflammatory levels of oxidative stress., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Herein, we describe a diastereoselective and straightforward synthetic approach to polysubstituted spirocyclic bis-lactams bearing both β- and γ-lactam cores with diverse substitution patterns. The method developed is based on a microwave-assisted Wolff rearrangement/Staudinger [2 + 2] cycloaddition sequence involving 3-diazopiperidine-2,4-diones and imines. The corresponding reaction tolerates a wide range of functionalities in both substrates, giving the target bis-lactams in generally high yields. The synthetic utility of the thermally promoted Wolff rearrangement has been extended to the interaction of 3-diazopiperidine-2,4-dione-derived ketenes with various nucleophiles leading to derivatives of 2-oxopyrrolidine-3-carboxylic acids. Our findings potentially pave an avenue for designing new compounds with a high degree of medicinal relevance by means of the processes studied.

Monitored tomographic reconstruction (MTR) is a potentially powerful tool for dose and time reduction in computed tomography scanning. We are the first to study the issue of practical implementation of MTR protocols in current-generation real-life instruments. We propose an empirical quantitative model for calculating acquisition and reconstruction times. It is demonstrated that projection acquisition order has a significant impact on the time and dose of tomographic experiments. The new alternative acquisition most suitable for MTR protocols is proposed. To estimate the restrictions and scope of applicability for MTR four typical commercial setups are studied within a proposed model. We construct an experimental stand for achieving a real-time reconstruction, together with validation of the proposed acquisition time model. We demonstrate that real-time reconstruction may be implemented without slowing down an acquisition process. An optimization of reconstruction from partial data is proposed, which allowed the production of 385 and 440 reconstructions for standard and proposed acquisition orders correspondingly during a single acquisition of 512 projections. The results of the study demonstrate that with proposed optimizations MTR can be effectively utilized for practical applications using the current generation of existing setups in industrial and nano tomography fields., Competing Interests: NO authors have competing interests., (Copyright: © 2024 Gilmanov et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Ring artifacts pose a major barrier to obtaining precise reconstruction in computed tomography (CT). The presence of ring artifacts complicates the use of automatic means of processing CT reconstruction results, such as segmentation, correction of geometric shapes, alignment of reconstructed volumes. Although there are numerous efficient methods for suppressing ring artifacts, many of them appear to be manual. Along with this, a large proportion of the automatic methods cope unsatisfactorily with the target task while requiring computational capacity. The current work introduces a projection data preprocessing method for suppressing ring artifacts that constitutes a compromise among the outlined aspects - automaticity, high efficiency and computational speed. Derived as the automation of the classical sinogram normalization method, the proposed method specific advantages consist in adaptability in relation to the filtered sinograms and the edge-preservation property proven within the experiments on both synthetic and real CT data. Concerning the challenging open-access data, the method has performed superior quality comparable to that of the advanced methods: it has demonstrated 70.4% ring artifacts suppression percentage (RASP) quality metric. In application to our real laboratory CT data, the proposed method allowed us to gain significant refinement of the reconstruction quality which has not been surpassed by a range of compared manual ring artifacts suppression methods.

We employed the selective-area-epitaxy technique using metalorganic chemical vapor deposition to fabricate and study samples of semiconductor heterostructures that incorporate highly strained InGaAs quantum wells (980-990 nm emission wavelength). Selective area epitaxy of InGaAs quantum wells was performed on templates that had a patterned periodic structure consisting of a window (where epitaxial growth occurred) and a passive mask (where epitaxial growth was suppressed), each with a width of 100 µm for every element. Additionally, a selectively grown potential barrier layer was included, which was characterized by an almost parabolic curvature profile of the surface. We conducted a study on the influence of the curvature profile of the growth surface on the optical properties of InGaAs quantum wells and the spatial distribution of composition in an ultrawide window. Our results showed that, under fixed selective-area-epitaxy conditions, the composition of the In x Ga 1- x As and the wavelength of the quantum-well emission changed across the width of the window. Our study demonstrates that increasing the curvature profile of the growth surface of highly strained quantum wells leads to a transition in the photoluminescence wavelength distribution profile across the window, from quasi-parabolic to inverted parabolic.

Video gaming and eSports is a quickly developing industry already involving billions of players worldwide. Gaming and eSports tournaments require strong mental abilities to avoid severe stress and other negative consequences upon completing the game. In this article, we report on the impact of emotions on a team performance. For this reason, we collect audio recordings and game logs from the players in real conditions at an eSports tournament. This data is further used in trained machine learning models for analysis of players' emotional conditions from the voice during the game. We considered recognition of several types of emotions as well as the background sounds. To do this, we trained 92.7% accuracy classifier of six most common classes of emotions and sounds in eSports audio and applied it to eSports data. As a result, we demonstrate that there is an opportunity to measure the eSports team's performance from the players' emotional conditions obtained from the voice communication. We found that there is a strong correlation among the performance of the team, communication between the players, and emotional sentiment of communication. The teams achieve much better results when they had much more internal conversations during the game.

We report a precise measurement of the parity-violating (PV) asymmetry A_{PV} in the elastic scattering of longitudinally polarized electrons from ^{48}Ca. We measure A_{PV}=2668±106(stat)±40(syst) parts per billion, leading to an extraction of the neutral weak form factor F_{W}(q=0.8733  fm^{-1})=0.1304±0.0052(stat)±0.0020(syst) and the charge minus the weak form factor F_{ch}-F_{W}=0.0277±0.0055. The resulting neutron skin thickness R_{n}-R_{p}=0.121±0.026(exp)±0.024(model)  fm is relatively thin yet consistent with many model calculations. The combined CREX and PREX results will have implications for future energy density functional calculations and on the density dependence of the symmetry energy of nuclear matter.

The human olfactory bulb (OB) has a laminar structure. The segregation of cell populations in the OB image poses a significant challenge because of indistinct boundaries of the layers. Standard 3D visualization tools usually have a low resolution and cannot provide the high accuracy required for morphometric analysis. X-ray phase contrast tomography (XPCT) offers sufficient resolution and contrast to identify single cells in large volumes of the brain. The numerous microanatomical structures detectable in XPCT image of the OB, however, greatly complicate the manual delineation of OB neuronal cell layers. To address the challenging problem of fully automated segmentation of XPCT images of human OB morphological layers, we propose a new pipeline for tomographic data processing. Convolutional neural networks (CNN) were used to segment XPCT image of native unstained human OB. Virtual segmentation of the whole OB and an accurate delineation of each layer in a healthy non-demented OB is mandatory as the first step for assessing OB morphological changes in smell impairment research. In this framework, we proposed an effective tool that could help to shed light on OB layer-specific degeneration in patients with olfactory disorder.

We report precision determinations of the beam-normal single spin asymmetries (A_{n}) in the elastic scattering of 0.95 and 2.18 GeV electrons off ^{12}C, ^{40}Ca, ^{48}Ca, and ^{208}Pb at very forward angles where the most detailed theoretical calculations have been performed. The first measurements of A_{n} for ^{40}Ca and ^{48}Ca are found to be similar to that of ^{12}C, consistent with expectations and thus demonstrating the validity of theoretical calculations for nuclei with Z≤20. We also report A_{n} for ^{208}Pb at two new momentum transfers (Q^{2}) extending the previous measurement. Our new data confirm the surprising result previously reported, with all three data points showing significant disagreement with the results from the Z≤20 nuclei. These data confirm our basic understanding of the underlying dynamics that govern A_{n} for nuclei containing ≲50 nucleons, but point to the need for further investigation to understand the unusual A_{n} behavior discovered for scattering off ^{208}Pb.

One of the classical approaches to solving color reproduction problems, such as color adaptation or color space transform, is the use of a low-parameter spectral model. The strength of this approach is the ability to choose a set of properties that the model should have, be it a complete coverage of a color triangle or an accurate description of the addition or multiplication of spectra, knowing only the tristimulus corresponding to them. The disadvantage is that some of the properties of the mentioned spectral models are confirmed only experimentally. This work is devoted to the theoretical substantiation of various properties of spectral models. In particular, we prove that the banded model is the only model that simultaneously possesses the properties of closure under addition and multiplication. We also show that the Gaussian model is the limiting case of the von Mises model and prove that the von Mises model unambiguously covers the color triangle in cases of both convex and non-convex spectral loci.

The BIA primary result sheets as a rule contain one-dimensional graphical scales with a selected area of normal values. In 1994, Piccoli et al . proposed BIVA, an alternative form of BIA data presentation, where two bioimpedance parameters are considered simultaneously as tolerance ellipses: resistance and reactance normalized to height. The purpose of this study is to develop an approach to data analysis in body composition bioimpedance research in two-dimensional representations. The data of 1.124.668 patients aged 5 to 85 years who underwent a bioimpedance study in Russian Health Centers from 2009 to 2015 were used. Statistical programming in the R Studio environment was carried out to estimate two-dimensional distribution densities of pairs of body composition parameters for each year of life. The non-Gaussian distribution is found in most parameters of bioimpedance analysis of body composition for most ages (Lilliefors test, p-value << 0.0001). The slices of the actual two-dimensional distribution pairs of body composition parameters had an irregular shape. The authors of the article propose using the actually observed distribution for populations where numerous bioimpedance studies have already been carried out. Such technology can be called two-dimensional bioimpedance analysis of human body composition (2DBIA). The 2DBIA approach is clearer for practitioners and their patients due to the use of body composition parameters in addition to electrical impedance parameters., Competing Interests: Conflict of interest Authors state no conflict of interest., (© 2021 S. P. Shchelykalina et al., published by Sciendo.)

Aim      To study features of diagnosis and treatment of acute myocardial infarction (AMI) in Russian hospitals, results of the treatment, and early and late outcomes (6 and 12 months after AMI diagnosis); to evaluate the consistence of the treatment with clinical guidelines; and to evaluate patients' compliance with the treatment.Material and methods  The program was designed for 3 years, including 24 months for recruitment of patients to the study. The study will include 10, 000 patients hospitalized with a confirmed diagnosis (I21 according to ICD-10) of ST segment elevation acute myocardial infarction (MI) (STEMI) or non-ST segment elevation MI (NSTEMI) based on criteria of the European Society of Cardiology Guidelines on Forth Universal Definition of Myocardial Infarction (2018). The follow-up period was divided into three stages: observation during the stay in the hospital and at 6 and 12 months following inclusion into the registry. The primary endpoint included cardiac death, nonfatal MI during the hospitalization and after one-year follow-up. Secondary endpoints were 6-months and one-year incidence of repeated MI, heart failure, ischemic stroke, clinically significant hemorrhage, unscheduled revascularization after discharge from the hospital, and the proportion of patients who continue on statins, antiplatelet drugs, and drugs of other groups for 6 months and 1 year.Results The inclusion of patients into the registry started in 2020 and will continue for 24 months. By the time of the article publication (June, 2021), more than 2,000 patients will be included.Conclusion      REGION-MI (Russian rEGIstry Of acute myocardial iNfarction) is a multicenter, retrospective and prospective observational cohort study that excludes any interference with the clinical practice. Results of the registry will help to analyze a real picture of medical care provided to patients with myocardial infarction and to schedule ways to improve the situation.

We report a precision measurement of the parity-violating asymmetry A&#95;{PV} in the elastic scattering of longitudinally polarized electrons from ^{208}Pb. We measure A&#95;{PV}=550±16(stat)±8(syst) parts per billion, leading to an extraction of the neutral weak form factor F&#95;{W}(Q^{2}=0.00616  GeV^{2})=0.368±0.013. Combined with our previous measurement, the extracted neutron skin thickness is R&#95;{n}-R&#95;{p}=0.283±0.071  fm. The result also yields the first significant direct measurement of the interior weak density of ^{208}Pb: ρ&#95;{W}^{0}=-0.0796±0.0036(exp)±0.0013(theo)  fm^{-3} leading to the interior baryon density ρ&#95;{b}^{0}=0.1480±0.0036(exp)±0.0013(theo)  fm^{-3}. The measurement accurately constrains the density dependence of the symmetry energy of nuclear matter near saturation density, with implications for the size and composition of neutron stars.

Selective area epitaxy (SAE) is widely used in photonic integrated circuits, but there is little information on the use of this technique for the growth of heterostructures in ultra-wide windows. Samples of heterostructures with InGaAs quantum wells (QWs) on GaAs (100) substrates with a pattern of alternating stripes (100-μm-wide SiO 2 mask/100-μm-wide window) were grown using metalorganic chemical vapour deposition (MOCVD). It was found that due to a local change in the growth rate of InGaAs QW in the window, the photoluminescence (PL) spectra measured from the edge to the center of the window exhibited maximum blueshifts of 14 and 19 meV at temperatures of 80 K and 300 K, respectively. Using atomic force microscopy, we have demonstrated that the surface morphologies of structures grown using standard epitaxy or SAE under identical MOCVD growth conditions correspond to a step flow growth with a step height of ~1.5 ML or a step bunching growth mode, respectively. In the structures grown with the use of SAE, a strong variation in the surface morphology in an ultra-wide window from its center to the edge was revealed, which is explained by a change in the local misorientation of the layer due to a local change in the growth rate over the width of the window.

This article demonstrates how a combination of well-known tools-a standard 2D detector (CCD (charge-coupled device) camera) and a crystal analyzer-can improve the multimodality of X-ray imaging and tomographic sensing. The use of a crystal analyzer allowed two characteristic lines of the molybdenum anode-Kα and Kβ-to be separated from the polychromatic radiation of the conventional X-ray tube. Thus, as a result of one measurement, three radiographic projections (images) were simultaneously recorded. The projection images at different wavelengths were separated in space and registered independently for further processing, which is of interest for the spectral tomography method. A projective transformation to compensate for the geometric distortions that occur during asymmetric diffraction was used. The first experimental results presented here appear promising.

An external cavity in Littrow configuration based on a reflective diffraction grating and a high-power semiconductor laser based on an asymmetric heterostructure with low optical loss was studied. A continuous-wave optical output power of 13 W with a linewidth of 0.15 nm was achieved for an external-cavity laser. It was shown that a decrease in the length of the laser chip to 1500 µm makes it possible to expand the tuning range of the lasing spectrum to 100 nm, while the maximum side-mode suppression reaches 45 dB, and at the edges of the spectral tuning range it is no worse than 30 dB. It was shown that the main factors in reducing the optical power when tuning the laser spectrum are an increase in the threshold current and internal optical loss of the laser chip.

It is shown that the use of low-voltage GaAs/AlGaAs thyristors as high-speed and high-current switches in vertical stacks with semiconductor lasers ensures the efficient generation of high-power ns-duration laser pulses. The lasing and current dynamics in vertical stacks based on laser diode mini bar emitting at 1060 nm and a single as well as a double thyristor switch is studied. The possibility is demonstrated that a laser diode mini bar (with 3 laser emitters) together with a single thyristor switch can generate laser pulses with a peak power of 6 W with a duration of 950 ps and a peak current of 12 A for an operating voltage of 28 V. The use of a double thyristor switch leads to a broadening of the current pulse due to different delays in turn-on of the thyristor switches, while the peak power and duration of laser pulses increase to 8 W and 1.4 ns, respectively. It is found that the stage of low-speed turn-on of the thyristor limits the efficient generation of current and laser pulses of ns duration at low operating voltages (less than 21V). An efficient generation of current and laser pulses by low-voltage thyristors at control currents of 2-320 mA is ensured by efficient impact ionization in the region of the reverse biased p-n junction at high values of operating voltages (more than 21V).

The response of a graphene-based humidity sensor is considered as a function of film structures. Analysis of the resistance changes due to water molecule adsorption on the graphene or multi-layer graphene (MLG) surface is performed for films with different structures and resistivities from hundreds of ohms/sq to hundreds of kilo-ohms/sq. The results revealed possible increase, decrease and non-monotonous behavior of resistance with changes in film structure. Adsorption of water molecules at grain boundary defects is assumed to lead to an increase in film resistivity due to the donor property of water and the p-type conductivity of graphene. Another type of conductive center with a higher capture cross-section is realized in the case of water molecule adsorption at edge defects in MLG films (the formation of conductive chains with ionic conductivity). If these chains form a continuous network the film resistivity decreases. The result of the competition between the opposite effects of the conductivity compensation and formation of the water-based conductive chains depends on the film structure and determines the response of humidity sensors. Sensor sensitivity is found to increase when only one type of defect determines water adsorption (edge defects or grain boundary defects).

The present report describes development of hexamethonium complexes based on fullerene C60. Hexamethonium has a limited penetration into CNS and therefore can antagonize central effects of nicotine only when given at high doses. In the present studies conducted in laboratory rodents, intraperitoneal administration of hexamethonium-fullerene complexes blocked effects of nicotine (convulsions and locomotor stimulation). When compared to equimolar doses of hexamethonium, complexes of hexamethonium with derivatives of fullerene C60 were 40 times more potent indicating an enhanced ability to interact with central nicotine receptors. Thus, fullerene C60 derivatives should be explored further as potential carrier systems for polar drug delivery into CNS.

Recently, a new high energy proton microscopy facility PRIOR (Proton Microscope for FAIR Facility for Anti-proton and Ion Research) has been designed, constructed, and successfully commissioned at GSI Helmholtzzentrum für Schwerionenforschung (Darmstadt, Germany). As a result of the experiments with 3.5-4.5 GeV proton beams delivered by the heavy ion synchrotron SIS-18 of GSI, 30 μm spatial and 10 ns temporal resolutions of the proton microscope have been demonstrated. A new pulsed power setup for studying properties of matter under extremes has been developed for the dynamic commissioning of the PRIOR facility. This paper describes the PRIOR setup as well as the results of the first static and dynamic proton radiography experiments performed at GSI.

The article presents an approach to the control of a UAV on the basis of 3D landmark observations. The novelty of the work is the usage of the 3D RANSAC algorithm developed on the basis of the landmarks' position prediction with the aid of a modified Kalman-type filter. Modification of the filter based on the pseudo-measurements approach permits obtaining unbiased UAV position estimation with quadratic error characteristics. Modeling of UAV flight on the basis of the suggested algorithm shows good performance, even under significant external perturbations.

A combination of X-ray tomography at different wavelengths and X-ray fluorescence analysis was applied in the study of two types of bone tissue changes: prolonged presence in microgravity conditions and age-related bone growth. The proximal tail vertebrae of geckos were selected for investigation because they do not bear the supporting load in locomotion, which allows them to be considered as an independent indicator of gravitational influence. For the vertebrae of geckos no significant differences were revealed in the elemental composition of the flight samples and the synchronous control samples. In addition, the gecko bone tissue samples from the jaw apparatus, spine and shoulder girdle were measured. The dynamics of structural changes in the bone tissue growth was studied using samples of a human fetal hand. The hands of human fetuses of 11-15 weeks were studied. Autonomous zones of calcium accumulation were found not only in individual fingers but in each of the investigated phalanges. The results obtained are discussed.

A study of the α- and β-dispersion of skin bioimpedance dependence on temperature and micro-hemodynamics is presented. The vascular tone changes during the cold test are verified by the wavelet-analysis of skin temperature signals obtained simultaneously with impedance measurements. Thirty three normal healthy subjects of 28  ±  7 years old were entered into the study. The tetra-polar electrode system was used to record the resistance and reactance; measurements were carried out at 67 frequencies, in a frequency range from 2 Hz to 50 kHz. It has been found that the impedance decreases with vasodilation and increases with vasoconstriction. The high values of correlation among thermal oscillation amplitudes and Nyquist diagram parameters prove the impedance dependence on blood flow in three frequency bands corresponding to the myogenic, neurogenic and endothelial vascular tone regulation mechanisms. Using an equivalent RC circuit, we obtained the changes in the Nyquist diagram matching the experimental data. The proposed descriptive α-dispersion model can be used to study mechanisms responsible for intercellular interaction.

High-energy proton microscopy provides unique capabilities in penetrating radiography including the combination of high spatial resolution and field-of-view, dynamic range of density for measurements, and reconstructing density variations to less than 1% inside volumes and in situ environments. We have recently proposed to exploit this novel proton radiography technique for image-guided stereotactic particle radiosurgery. Results of a first test for imaging biological and tissue-equivalent targets with high-energy (800 MeV) proton microscopy are presented here. Although we used a proton microscope setup at ITEP (Moscow, Russia) optimized for fast dynamic experiments in material research, we could reach a spatial resolution of 150 μm with approximately 10(10) protons per image. The potential of obtaining high-resolution online imaging of the target using a therapeutic proton beam in the GeV energy region suggests that high-energy proton microscopy may be used for image-guided proton radiosurgery., (Copyright © 2012 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.)

This paper presents the results of a comprehensive analysis of structural changes in the caudal vertebrae of Turner's thick-toed geckos by computer microtomography and X-ray fluorescence analysis. We present algorithms used for the reconstruction of tomographic images which allow to work with high noise level projections that represent typical conditions dictated by the nature of the samples. Reptiles, due to their ruggedness, small size, belonging to the amniote and a number of other valuable features, are an attractive model object for long-orbital experiments on unmanned spacecraft. Issues of possible changes in their bone tissue under the influence of spaceflight are the subject of discussions between biologists from different laboratories around the world.

The purpose of the study was to determine the capability of bioimpedance spectroscopy (BIS) to evaluate the hematological and biochemical parameters of blood. BIS readings were estimated on an ABC-01 Medass hardware-computer complex; blood hematological and biochemical parameters (n = 46) were determined on automated analyzers. The BIS readings were found to be closely correlated with packed cell volume and hemoglobin and red blood cell values, but weakly related to plasma biochemical parameters and white blood cell counts. BIS readings may be used to calculate red blood cell counts taken in units of measurement in hematological practice, by applying the multiple regression equations. Thus, the blood BIS technique may be employed to estimate basic hematological parameters (hemoglobin concentration, red blood cell counts, and packed cell volume).

Algebraic Reconstruction Technique (ART) is a widely employed method in computed tomography since it has certain advantages, such as allowing reconstruction of data with missing projections in some angle ranges, over other techniques such as Filtered Back Projection (FBP). Recently, a regularisation technique for ART, RegART, was introduced which provides greatly reduced noise levels. However, a serious drawback of both ART and RegART is the computational complexity of the methods. In this paper, we present a fast version of RegART, which makes use of nVidia's CUDA technology, and show that this approach performs favourably compared to FBP.

The estimation of the smooth pursuit efficiency in healthy young adults by method based on stroboscopic stimulation is given. The influence of manual function asymmetry on smooth pursuit was tested. Subjects were classified as left-handed or right-handed under a well known handedness questionnaire of Annett supplemented by Luria's tests. It was shown that the strong right-handed persons have a high quality of smooth pursuit of stimuli moving horizontally in rightward and leftward directions with the velocities 20 degrees/s and 25 degrees/s. Left-handed persons track similar stimuli, on the average, worse than the strong right-handed ones. It haven't been observed the influence of manual function asymmetry on the dependence of the smooth pursuit efficiency from the moving stimuli direction (left to right or right to left).

The investigation has shown that patients with the diagnosed abdominal aortic aneurysms must be operated, the age being not considered a contraindication to surgical treatment. Five years survival of the patients after resection of the abdominal aortic aneurysm and its prosthesis does not depend on the age and is higher than 70%, while the expectant management leads to rupture of the aneurysm and death of 70% of the patients. A medical algorithm has been developed allowing reduction of lethality of elderly patients with abdominal aortic aneurysms and less frequency of complications.

Maximum magnetic resonance artifacts from stents are often determined by the presence of ferromagnetic compounds in the delivery system. We propose a mathematic model describing artifacts caused by nitinol stents. A method for evaluation of critical radial rigidity of the stents was developed.

A portable two-frequency tetrapolar impedance meter was developed to study the state of liquid compartments of human body under zero-gravity conditions. The portable impedance meter makes it possible to monitor the hydration state of human body under conditions of long-term space flight on board international space station.

The operations of semiclosed endarterecromy of the aortofemoral zone arteries were shown to have a number of advantages over shunting interventions with synthetic transplants. They are quick, not traumatic and have better results of long term patency. However, their application is limited by certain indications. Femoral amputations in patients with lesions of the aorta and iliac arteries independent of the age should not be recommended as a method of treatment of critical ischemia of lower extremities. Reconstructive operations on the vessels of this zone provide longer duration and better quality of life of the patients.

High-energy heavy ions are an ideal tool to generate homogeneously excited, extended volumes of nonthermal plasmas. Here, the high-energy loss (dE/dx) and absolute power deposition of heavy ions interacting with matter has been used to pump an ultraviolet laser. A pulsed 70 MeV/u 238U beam with up to 2.5 x 10(9) particles in approximately 100 ns beam bunches was stopped in a 1.2 m long laser cell filled with a 1.6 bar Ar-Kr-F2 mixture (typically 50%:49.9%:0.1%). Laser effect on the 248 nm KrF* excimer transition is clearly demonstrated.

The subject of high-energy-density (HED) states in matter is of considerable importance to numerous branches of basic as well as applied physics. Intense heavy-ion beams are an excellent tool to create large samples of HED matter in the laboratory with fairly uniform physical conditions. Gesellschaft für Schwerionenforschung, Darmstadt, is a unique worldwide laboratory that has a heavy-ion synchrotron, SIS18, that delivers intense beams of energetic heavy ions. Construction of a much more powerful synchrotron, SIS100, at the future international facility for antiprotons and ion research (FAIR) at Darmstadt will lead to an increase in beam intensity by 3 orders of magnitude compared to what is currently available. The purpose of this Letter is to investigate with the help of two-dimensional numerical simulations, the potential of the FAIR to carry out research in the field of HED states in matter.

Cerebral blood flow and metabolism were studied in 44 patients with acute severe craniocerebral injuries (contusions of the brain and removal of intracranial hematomas) with consciousness depression (moderate coma), hospitalized in intensive neurological care wards. Oxygen supply to the brain was repeatedly evaluated (acid-base status of the jugular vein blood, oxygen arterio-venous difference, oxygen extraction coefficient), oxymetry of the brain was repeatedly carried out, and vital functions were monitored over the entire period of disease. Cerebral blood flow was monitored by rheoencephalography, which helped timely detect the changes in cerebral blood flow in patients with craniocerebral injuries during different ventilation protocols used in intensive care. All studies were carried out during three stages: 1) initial stage, when the patients were brought to intensive neurological care wards after surgical intervention, and during normoventilation (paCO2 36-40 mm Hg; 2) moderate hyperventilation (paCO2 35-26 mm Hg); and 3) pronounced hyperventilation (paCO2 25-20 mm Hg). Specific changes in the cerebral blood flow during the acute period of craniocerebral injury were detected during different ventilation regimens in 2 groups of patients: group 1 with lethal outcomes and group 2 with positive changes.

There were studied 14 children (mean age 5.71 +/- 0.60 years, body weight 18.95 +/- 3.50 kg, height 101.0 +/- 4.03 cm) with initially normal osmotic and volumic status. Plasma osmolarity, blood aldosterone level, aqueous compartments balance were (evaluated by segmented bioimpedance spectrometry), urine osmolarity and diuresis were investigated after bolus injection of x-ray contrast agent (RCA) urografin-60% (mean volume 2 ml/kg for 2-4 sec). A statistically significant gradual decrease in the total volume of water (TVW) in the organism was observed, with 8.53% deficiency of TVW by the second hour after RCA injection in comparison with the initial level. TVW deficiency developed as the result of diuresis which increased 7-fold in the presence of increased plasma osmolarity after injection of RCA bolus. Correction of the volume of circulating blood and plasma was carried out mainly at the expense of intracellular liquid, whose deficiency was actually 4.5 times higher than of extracellular liquid. Bioimpedance spectrometry indicated centralized redistribution of water in the organism, as TVW deficiency was mainly due to water in the limbs. The results indicate the need in infusion therapy after RCA injection in order to correct the resultant water deficit.

The present work was undertaken to examine the effect of 2 month glucocorticoid treatment on estradiol-induced proliferation in the uterus. Ovariectomized rats were treated with long-acting triamcinolone acetonide or saline for 60 days followed by a single injection of estradiol dipropionate or vehicle. Proliferation in the uterus was estimated by the mitotic index, bromodeoxyuridine-labelling index and proliferating cells nuclear antigen-labelling index 24, 36 and 48 h after the injection of estradiol or vehicle. Two month glucocorticoid treatment resulted in an initial decrease in all the parameters for luminal and glandular epithelia followed by an increase to 48 h after estradiol injection, and in a large increase in all proliferative parameters for stromal and myometrial cells at all periods of observation, compared with control rats untreated with glucocorticoid. The 2 month glucocorticoid treatment protocol had no significant effect on the parameters without estradiol administration. Analysis of proliferation for myometrial cells was also performed after 1 month treatment with glucocorticoid followed by estradiol or saline. Results showed no significant influence of 1 month treatment with glucocorticoid on myometrial cells.

Background/aims: It has been shown that acute or short-term treatments with glucocorticoids lead to a marked decrease in proliferation in the stomach and large intestine. The effects of more prolonged glucocorticoid treatment on cell renewal in these organs are not known. The present work was therefore undertaken to examine the proliferative activity in the stomach and colon during 2 months of glucocorticoid treatment in comparison with shorter treatments., Methods: Rats were treated with either the glucocorticoid triamcinolone acetonide or vehicle for 63, 33 or 3 days. Proliferation was assessed in the glandular epithelium of the fundal part of the stomach and in the epithelium of the colonic crypts using three criteria: the mitotic index; the bromodeoxyuridine labelling index, and the proliferating cell nuclear antigen-labelling index (percentage of mitotic or labelled cells)., Results: Treatment with glucocorticoid for 63 days resulted in a very significant increase in all proliferative parameters tested in the gastric mucosa and the colonic crypts. On the contrary, treatments with glucocorticoid for 3 or 33 days had a marked inhibitory influence on proliferation in these tissues., Conclusion: As opposed to treatments for 3 or 33 days, glucocorticoid treatment for 2 months leads to an increase in the number of cycling cells in the gastric and colonic mucosae., (Copyright 2000 S. Karger AG, Basel)

Data about glucocorticoid influence on proliferation in the esophagus and small intestine are very contradictory and need to be reexamined. Moreover, only the effects of acute or short-term treatments with glucocorticoids have been demonstrated, whereas nothing is known about their effects under chronic exposure. This work was therefore carried out to examine proliferative activity in the esophagus and small intestine under conditions of acute and chronic glucocorticoid exposure. Rats were treated with either glucocorticoid triamcinolone acetonide or vehicle for 3, 33, or 63 days. Proliferation was assessed in the basal layer of esophageal epithelium and in the epithelium of jejunal crypts, using three criteria, as the number of mitotic, bromodeoxyuridine-labelled, and proliferating cell nuclear antigen-labelled cells. Treatment with glucocorticoid for 3 days led to a slight decrease in all parameters in the esophageal epithelium and had almost no effect on proliferation in the epithelium of jejunal crypts. Long-term treatment with glucocorticoid for either 33 or 63 days resulted in an increase in all parameters tested in both esophageal and jejunal crypt epithelia. Sixty-three-day treatment had a more prominent and significant (P < 0.05) effect. These results suggest that acute glucocorticoid treatment nonsignificantly reduces the number of cells in the cell cycle in the esophageal epithelium, whereas chronic treatment increases the number of proliferating cells in both esophageal and jejunal crypt epithelia.

A descriptive analysis of birth defects and malformations was performed to assess whether the rates of these defects correlate with the geographic areas of Belarus that received different levels of 137Cs contamination resulting from the Chernobyl catastrophe. Since this accident in 1986, the frequency of both congenital and fetal abnormalities in the Republic of Belarus has apparently increased. This increase is most prominent in areas with at least 555 9Bq/m2 radioactive contamination, although it has not been possible to correlate the individual dose received by a pregnant woman with the incidence of congenital malformations. The types of anomalies that were most increased in frequency were multiple congenital malformations, polydactyly, and reduction limb defects. These malformations are commonly associated with dominant new mutations. Chromosomal disorders such as occur in Down syndrome were not increased in frequency, nor could teratogenic effects be attributed to exposure to ionizing radiation. Preventive measures have apparently reduced the number of births with congenital abnormalities but have had no apparent effect on the frequency of fetal defects. Results of our analysis are consistent with the hypothesis that ionizing radiation released during the Chernobyl accident may have placed fetuses and neonates at risk for congenital malformations. Epidemiological studies are now required to determine whether a mother's radiation dose correlates with congenital malformations in her children.

The requirements for selection of congenital malformations in the system of genetic monitoring as models have been studied. Model malformations have been shown to be easily and reliably diagnosed even in infancy. Their rate should be not less than 1:5000 births. The precise knowledge of the genetics of model forms is needed as well. Down's syndrome registration is the most convenient method for evaluation of mutations in a genome. We recommend registration in total all multiple congenital malformations (without Down's syndrome) for estimation of dominant mutability dynamics, as it was shown that more than 11% of all multiple malformations are caused by sporadic dominant mutations.

The authors propose the methods of measuring the hemodynamic indices on the basis of the impedance rheoplethysmography, electrocardiometer and programming microcalculator. The use of the disk electrodes instead of the circular electrodes makes it possible to take measurements during physical tests, e.g. veloergometric tests.