Evaluation of physicochemical parameters as indicators of diesel adulteration.

Diesel adulteration not only reduces engine performance and lifespan but also has a stiffening effect on the economy. Therefore, regulatory agencies and petroleum laboratories are constantly adopting various methods to ensure that commercial diesel is pure and of good quality. Despite the introduction of solvent tracer analysis as a reliable means of detecting adulteration, most laboratories still depend on the physicochemical parameters of diesel as an indicator of adulteration. This research aimed to document the feasibility of using quality parameters to detect diesel adulteration. Neat diesel samples were mixed with some common adulterants (kerosene, premix, and condensate) at varying concentrations. The quality of each admixture was analysed using the ERASPEC fuel analyser and physicochemical parameters including density, kinematic viscosity, cetane index, and flashpoint were recorded. A negative correlation was observed between adulteration and all quality parameters. At low levels of adulteration, physicochemical parameters were within the required range. However, diesel with adulterants above 20 % v/v had cetane index, density, and flashpoint values not conforming with quality standards. Kinematic viscosity of diesel remained within the required limits despite the levels of adulteration. Physicochemical parameters, though generally accepted as good indicators of fuel quality, were not reliable indicators of diesel adulteration, especially at low levels. At higher levels of adulteration, the type of adulterant present must be considered if physicochemical parameters are to be used to predict adulteration. However, it is recommended that physicochemical parameters be used in combination with other techniques to detect diesel adulteration.

Potential insect threats to pennycress, Thlaspi arvense (Brassicales: Brassicaceae), an emerging oilseed cover crop.

Pennycress (Thlaspi arvense L.) is an annual plant in temperate regions that often grows as a weed. Pennycress is being domesticated as a new winter cover crop and oilseed crop for incorporation in the Midwest United States corn-soybean rotation, where it could offer economic and environmental benefits. While pennycress is gaining attention as a promising new crop, there remains a significant gap in understanding its interaction with insect communities and agroecosystems. This review compiles available information on insect herbivores (potential pests) and beneficial insects associated with pennycress growing in the wild (natural areas) or as a weed in agricultural areas. The limited knowledge on the response of pennycress to stressors (defoliation, stem injury and stand loss) similar to injury that could be caused by insects is also compiled here. By shedding light on the insects associated with pennycress and how pennycress might respond to injury from insect pests, this review sets the stage for further research and development of integrated pest management programs for insect pests of this new crop.

Immature development and adult longevity of the soybean tentiform leafminer (Lepidoptera: Gracillariidae).

The leaf-mining microlepidopteran, Macrosaccus morrisella (Fitch) (Lepidoptera: Gracillariidae), has emerged as a new pest of soybean, Glycine max (L.) Merrill (Fabales: Fabaceae), in Canada and the United States, but little is known about its life history traits. Thus, this study was conducted to assess the immature developmental rate of M. morrisella, from egg to adult emergence, on soybean at different temperatures, and the longevity of adults supplied with water and/or honey at different temperatures. The time to 50% emergence of adults was 71.90, 36.33, 24.62, and 17.83 days at 15, 20, 25, and 30 °C, respectively. The lower developmental threshold of M. morrisella was estimated at 8.96 °C, with 425.04 degree-days required for egg-to-adult development. For adult longevity, time to 50% mortality at 25 °C was 15.00, 4.00, and 2.00 days when adults were provided with 25% (v/v) honey-water solution, water, or nothing, respectively. In a follow-up experiment, time to 50% mortality at 25 °C was 24.00, 6.00, 3.00, and 3.00 days when adults were provided with honey and water (offered separately), honey, water, or nothing, respectively, with a synergistic effect when honey and water were offered simultaneously as opposed to honey or water alone. Finally, when fed 25% (v/v) honey-water solution and maintained at 20, 25, and 30 °C, time to 50% mortality of adults was 26.50, 15.00, and 15.00 days. These results inform the understanding of the basic biology of M. morrisella and will help inform the future development of management programs for this insect in soybean.

Threat directionality modulates defensive reactions in humans: cardiac and electrodermal responses.

Features of threatening cues and the associated context influence the perceived imminence of threat and the defensive responses evoked. To provide additional knowledge about how the directionality of a threat (i.e. directed-towards or away from the viewer) might impact defensive responses in humans, participants were shown pictures of a man carrying a gun (threat) or nonlethal object (neutral) directed-away from or towards the participant. Cardiac and electrodermal responses were collected. Compared to neutral images, threatening images depicting a gun directed-towards the participant induced sustained bradycardia and an increased electrodermal response, interpreted as immobility under attack. This defensive immobility reaction is evoked by high perceived threat and inescapable situations and indicates intense action preparation. Pictures of guns directed-away from the participant induced shorter bradycardia and no significant modulation of the electrodermal response compared to neutral pictures, which might be consistent with the perception of a less threatening situation. The results show that the directionality of threat stimuli is a key factor that prompts different patterns of defensive responses.

Bias against parents in science hits women harder.

Worldwide, parenthood remains a major driver for the reduced participation of women in the job market, where discrimination stems from people's biases against mothers, based on stereotypes and misconceptions surrounding the vision of motherhood in our society. In academia, parenthood may be perceived as negatively affecting scientists' commitment and dedication, especially women's. We conducted a survey amongst Brazilian scientists and found that mothers self-reported a higher prevalence of negative bias in their workplace when compared to fathers. The perception of a negative bias was influenced by gender and career status, but not by race, scientific field or number of children. Regarding intersections, mothers with less than 15 years of hiring reported having suffered a higher rate of negative bias against themselves. We discuss implications of these results and suggest how this negative bias should be addressed in order to promote an equitable environment that does not harm women in science.

Accurate Reduced Models for the pH Oscillations in the Urea-Urease Reaction Confined to Giant Lipid Vesicles.

This theoretical study concerns a pH oscillator based on the urea-urease reaction confined to giant lipid vesicles. Under suitable conditions, differential transport of urea and hydrogen ion across the unilamellar vesicle membrane periodically resets the pH clock that switches the system from acid to basic, resulting in self-sustained oscillations. We analyze the structure of the phase flow and of the limit cycle, which controls the dynamics for giant vesicles and dominates the pronouncedly stochastic oscillations in small vesicles of submicrometer size. To this end, we derive reduced models, which are amenable to analytic treatments that are complemented by numerical solutions, and obtain the period and amplitude of the oscillations as well as the parameter domain, where oscillatory behavior persists. We show that the accuracy of these predictions is highly sensitive to the employed reduction scheme. In particular, we suggest an accurate two-variable model and show its equivalence to a three-variable model that admits an interpretation in terms of a chemical reaction network. The faithful modeling of a single pH oscillator appears crucial for rationalizing experiments and understanding communication of vesicles and synchronization of rhythms.

Examining the utility of a photorealistic virtual ear in otologic education.

BACKGROUND: Otolaryngology-head and neck surgical (OHNS) trainees' operating exposure is supplemented by a combination of didactic teaching, textbook reading, and cadaveric dissections. Conventional teaching, however, may not adequately equip trainees with an understanding of complex visuospatial relationships of the middle ear. Both face and content validation were assessed of a novel three-dimensional (3D) photorealistic virtual ear simulation tool underwent face and content validation as an educational tool for OHNS trainees. METHODS: A three-dimensional mesh reconstruction of open access imaging was generated using geometric modeling, which underwent global illumination, subsurface scattering, and texturing to create photorealistic virtual reality (VR) ear models were created from open access imaging and comiled into a educational platform. This was compiled into an educational VR platform which was explored to validate the face and content validity questionnaires in a prospective manner. OHNS post-graduate trainees were recruited from University of Toronto and University of Calgary OHNS programs. Participation was on a voluntary basis. RESULTS: Total of 23 OHNS post-graduate trainees from the two universities were included in this study. The mean comfort level of otologic anatomy was rated 4.8 (± 2.2) out of 10. Senior residents possessed more otologic surgical experience (P < 0.001) and higher average comfort when compared to junior residents [6.7 (± 0.7) vs. 3.6 (± 1.9); P = 0.001]. Face and content validities were achieved in all respective domains with no significant difference between the two groups. Overall, respondents believed OtoVIS was a useful tool to learn otologic anatomy with a median score of 10.0 (8.3-10.0) and strongly agreed that OtoVIS should be added to OHNS training with a score of 10.0 (9.3-10.0). CONCLUSIONS: OtoVIS achieved both face and content validity as a photorealistic VR otologic simulator for teaching otologic anatomy in the postgraduate setting. As an immersive learning tool, it may supplement trainees' understanding and residents endorsed its use.

Deposition of Thick SiO2 Coatings to Carbonyl Iron Microparticles for Thermal Stability and Microwave Performance.

Thick dielectric SiO2 shells on the surface of iron particles enhance the thermal and electrodynamic parameters of the iron. A technique to deposit thick, 500-nm, SiO2 shell to the surface of carbonyl iron (CI) particles was developed. The method consists of repeated deposition of SiO2 particles with air drying between iterations. This method allows to obtain thick dielectric shells up to 475 nm on individual CI particles. The paper shows that a thick SiO2 protective layer reduces the permittivity of the 'Fe-SiO2-paraffin' composite in accordance with the Maxwell Garnett medium theory. The protective shell increases the thermal stability of iron, when heated in air, by shifting the transition temperature to the higher oxide. The particle size, the thickness of the SiO2 shells, and the elemental analysis of the samples were studied using a scanning electron microscope. A coaxial waveguide and the Nicholson-Ross technique were used to measure microwave permeability and permittivity of the samples. A vibrating-sample magnetometer (VSM) was used to measure the magnetostatic data. A synchronous thermal analysis was applied to measure the thermal stability of the coated iron particles. The developed samples can be applied for electromagnetic compatibility problems, as well as the active material for various types of sensors.

Comparison of mid-term clinical results between lag screw fixation and Kirschner wire fixation after close reduction in adolescent triplane distal tibia epiphyseal fracture.

OBJECTIVE: To compare the mid-term clinical results of lag screw and Kirschner wire fixation(KWF) for close reduction in triplane distal tibia epiphyseal fracture. METHODS: A retrospective analysis of 25 cases of triplane fractures of the distal tibia treated in our department from Jan 2017 to Dec 2019 was performed, Lag screw fixation(LSF) was used in 14 cases and Kirschner wire fixation in 11 cases, the clinical results were evaluated by premature epiphyseal closure(PPC) rate, the American Orthopaedic Foot and Ankle Score (AOFAS) Ankle-hindfoot foot scoring system, the lateral distal tibial angle (LDTA) from X-ray. RESULTS: All the 25 children were followed up for a mean of 34(ranging 26-52) months. AOFAS scores improved from a mean of 33(ranging 29-43) pre-op, to 82(ranging 77-88) at three month follow up, to 92 (ranging 88-98) at last follow-up in all 25 cases. Till last follow up there was no cases premature physeal closure in LSF group but 4 cases in KWF group, LDTA in both groups at last follow up shows no ankle varus or valgus deformity, and the ankle joint function was not limited in all cases. CONCLUSION: Lag screw and Kirschner wire fixation methods can both achieve good clinical effects for triplane distal tibia epiphyseal fracture. Lag screw fixation provide lower PPC rate but Kirschner wire fixation save one anesthesia and surgery.

Non-sterile gloves and dressing versus sterile gloves, dressings and drapes for suturing of traumatic wounds in the emergency department: a non-inferiority multicentre randomised controlled trial.

BACKGROUND: Patients with traumatic wounds frequently present to the ED. Literature on whether to treat these wounds sterile or non-sterile is sparse. Non-sterile treatment has the advantage of saving resources and costs, and could be of value in health settings where sterile materials are not readily available. Our objective was to compare the rate of wound infection after suturing traumatic lacerations with non-sterile gloves and dressings versus sterile gloves, dressings and drapes in the ED. We hypothesised that non-sterile gloves and dressings would be non-inferior to sterile gloves, dressings and drapes. The non-inferiority margin was set at 2%. METHODS: A multicentre single-blinded randomised controlled trial testing for non-inferiority of non-sterile gloves and dressings versus sterile gloves, dressings and drapes for suturing of traumatic wounds was performed in 3 EDs in The Netherlands. Adults with uncomplicated wounds were included from July 2012 to December 2016. At the time of treatment, patient and wound characteristics and management were documented. The outcome was wound infection, which was identified during follow-up in the treating ED at 5-14 days postprocedure. RESULTS: From 2468 eligible patients, 1480 were randomised in a sterile (n=747) or non-sterile (n=733) protocol. Baseline characteristics were similar in both study arms. The observed wound infection rate in the non-sterile group was 5.7% (95% CI 4.0% to 7.5%) vs 6.8% (95% CI 5.1% to 8.8%) in the sterile group. The mean difference of the wound infection rate of the two groups was -1.1% (95% CI -3.7% to 1.5%). CONCLUSION: Although recruitment ceased prior to reaching our planned sample size, the findings suggest that there is unlikely to be a large difference between the non-sterile gloves, dressings and sterile gloves, dressings and drapes for suturing of traumatic wounds in the ED. TRIAL REGISTRATION NUMBER: NL 34798.078.11, NTR3541.

Lack of Evidence for Fitness Costs in Soybean Aphid (Hemiptera: Aphididae) With Resistance to Pyrethroid Insecticides in the Upper Midwest Region of the United States.

Twenty years after the arrival of soybean aphid, Aphis glycines Matsumura (Hemiptera: Aphididae), in the United States, it remains the most economically important arthropod pest of soybean in the Upper Midwest Region. After years of repeated and sustained insecticidal pressures placed on the aphid, resistance to the pyrethroid class of insecticides has been documented in multiple years over a large geographic area. In this study, the fitness of aphid isolates displaying resistant and susceptible phenotypes to λ-cyhalothrin were compared within several experiments over three soybean-growing seasons. Rates of population increase were evaluated on whole plants in the greenhouse, intrinsic rates of increase were calculated from leaf discs in the laboratory, and aphid size and asymmetry were compared through tibial measurements. No evidence of a fitness cost associated with the resistant phenotype was seen in any of our experiments. In contrast, individual resistant isolates occasionally supported significantly higher fitness values than some susceptible isolates. Additionally, a pooled analysis comparing resistant and susceptible phenotypes across years and isolates revealed that, on average, the resistant phenotype had significantly higher fitness values than the susceptible phenotype in most experiments. The lack of reproductive fitness costs associated with the pyrethroid-resistant phenotype raises concerns for longevity of pyrethroid use in soybean aphid management.

Change-point analysis of lambda-cyhalothrin efficacy against soybean aphid (Aphis glycines Matsumura): identifying practical resistance from field efficacy trials.

BACKGROUND: Soybean aphid (Aphis glycines Matsumura) remains the most economically important arthropod pest of soybean in the Upper Midwest Region of the USA. Soybean aphid resistance to the pyrethroid insecticides emerged in 2015; however, the reduction in the efficacy of field applications of pyrethroid insecticides has not been quantified. Based on time-series data from insecticide efficacy trials at two locations, a novel approach of continuous two-phase change point-regression models was used to indicate whether a change in percent control had occurred, and to provide an indication of when and to what degree the percent control had changed. RESULTS: At both locations examined in this study, a significant change point for percent control of λ-cyhalothrin was detected in 2014, thus marking the onset of practical resistance in the soybean aphid. Percent control decreased at a rate of 4.30% and 19.90% per year at these locations. By contrast, percent control for chlorpyrifos remained high over time with no significant change point. CONCLUSION: This research demonstrates that retrospective time-series analysis of insecticide efficacy data can identify the onset and magnitude of practical resistance in the field. This further validates and compliments the other lines of evidence related to pyrethroid resistance in soybean aphid. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Linear Support Vector Machine Classification of Plant Stress From Soybean Aphid (Hemiptera: Aphididae) Using Hyperspectral Reflectance.

Spectral remote sensing has the potential to improve scouting and management of soybean aphid (Aphis glycines Matsumura), which can cause yield losses of over 40% in the North Central Region of the United States. We used linear support vector machines (SVMs) to determine 1) whether hyperspectral samples could be classified into treat/no-treat classes based on the economic threshold (250 aphids per plant) and 2) how many wavelengths or features are needed to generate an accurate model without overfitting the data. A range of aphid infestation levels on soybean was created using caged field plots in 2013, 2014, 2017, and 2018 in Minnesota and in 2017 and 2018 in Iowa. Hyperspectral measurements of soybean canopies in each plot were recorded with a spectroradiometer. SVM training and testing were performed using 15 combinations of normalized canopy reflectance at wavelengths of 720, 750, 780, and 1,010 nm. Pairwise Bonferroni-adjusted t-tests of Cohen's kappa values showed four wavelength combinations were optimal, namely model 1 (780 nm), model 2 (780 and 1,010 nm), model 3 (780, 1,010, and 720 nm), and model 4 (780, 1,010, 720, and 750 nm). Model 2 showed the best overall performance, with an accuracy of 89.4%, a sensitivity of 81.2%, and a specificity of 91.6%. The findings from this experiment provide the first documentation of successful classification of remotely sensed spectral data of soybean aphid-induced stress into threshold-based classes.

Synovial chondromatosis combine with synovial tuberculosis of knee joint: a case report.

BACKGROUD: Synovial chondromatosis is a rare synovial-derived metaplasia disease that comes from the formation of cartilage nodules within the synovial connective tissue of the joint. Knee tuberculosis is a disease caused mostly by the pulmonary tuberculosis and a few by tuberculosis of the digestive tract and lymphatic. tube. CASE PRESENTATION: Herein we report a 3-year-old child admitted by intermittent swelling of left knee joint with lameness for half a year, the patient received surgical treatment. The loose bodies filled in the joint cavity was taken out and the degenerative synovium was excised. Biopsy confirmed as synovial chondromatosis combined with synovial tuberculosis of knee joint. After 6 months follow-ups, knee swelling and claudication get totally recovered and the gait of patient recover back to normal. CONCLUSION: Careful investigation of children with knee pain is recommended to avoid misdiagnosis, Synovial chondromatosis combine with tuberculosis should be considered a differential diagnosis in a child with knee pain.

Evidence base for point-of-care ultrasound (POCUS) for diagnosis of skull fractures in children: a systematic review and meta-analysis.

BACKGROUND: Blunt head trauma is a common presentation to emergency departments (EDs). Identifying skull fractures in children is important as they are known factor of risk for traumatic brain injury (TBI). Currently, CT is the reference standard for diagnosing skull fractures and TBIs in children. Identifying skull fractures with point-of-care ultrasound (POCUS) may help risk-stratify children for TBI following blunt trauma. The purpose of this study is to evaluate the sensitivity, specificity, positive predictive value and negative predictive value of POCUS in identifying skull fractures in children. METHODS: A systematic search was performed on 17 July 2020 in Ovid Medline, Cochrane Library, Google Scholar, Web of Science and Embase. Prospective studies reporting skull fractures diagnosed with ultrasound in children younger than 18 years due to blunt head injury were included. Studies that did not confirm the fracture with CT were excluded. The quality of studies was evaluated using the QUADAS-2 tool. Data were extracted from the eligible studies to calculate outcomes such as sensitivity and specificity; when possible overall outcomes were calculated. RESULTS: Seven studies were included. All eligible studies included patients for whom the decision to perform a CT scan was made in advance. Overall, the included studies demonstrated low risk of bias or had minor concerns regarding risk of bias. The pooled data (n=925) demonstrated a sensitivity of 91%, specificity of 96%, positive predictive value of 88% and negative predictive value of 97%. CONCLUSION: The included studies demonstrate minor methodological limitations. Overall, the evidence suggests that POCUS is a valid option for diagnosing skull fractures in children visiting the ED after blunt head injury.

Effects of feeding injury from Popillia japonica (Coleoptera: Scarabaeidae) on soybean spectral reflectance and yield.

Remote sensing has been shown to be a promising technology for the detection and monitoring of plant stresses including insect feeding. Popillia japonica Newman, is an invasive insect species in the United States, and a pest of concern to soybean, Glycine max (L.) Merr., in the upper Midwest. To investigate the effects of P. japonica feeding injury (i.e., defoliation) on soybean canopy spectral reflectance and yield, field trials with plots of caged soybean plants were established during the summers of 2020 and 2021. In each year, field-collected P. japonica adults were released into some of the caged plots, creating a gradient of infestation levels and resulting injury. Estimates of injury caused by P. japonica, ground-based hyperspectral readings, total yield, and yield components were obtained from the caged plots. Injury was greatest in the upper canopy of soybean in plots infested with P. japonica. Overall mean canopy injury (i.e., across lower, middle, and upper canopy) ranged from 0.23 to 6.26%, which is representative of injury levels observed in soybean fields in the Midwest United States. Feeding injury from P. japonica tended to reduce measures of soybean canopy reflectance in near infra-red wavelengths (~700 to 1000 nm). These results indicate that remote sensing has potential for detection of injury from P. japonica and could facilitate scouting for this pest. Effects of P. japonica injury on total yield were not observed, but a reduction in seed size was detected in one of the two years. The threat to soybean yield posed by P. japonica alone appears minimal, but this pest adds to the guild of other defoliating insects in soybean whose combined effects could threaten yield. The results of this research will guide refinement of management recommendations for this pest in soybean and hold relevance for other cropping systems.

Stochastic pH Oscillations in a Model of the Urea-Urease Reaction Confined to Lipid Vesicles.

The urea-urease clock reaction is a pH switch from acid to basic that can turn into a pH oscillator if it occurs inside a suitable open reactor. We numerically study the confinement of the reaction to lipid vesicles, which permit the exchange with an external reservoir by differential transport, enabling the recovery of the pH level and yielding a constant supply of urea molecules. For microscopically small vesicles, the discreteness of the number of molecules requires a stochastic treatment of the reaction dynamics. Our analysis shows that intrinsic noise induces a significant statistical variation of the oscillation period, which increases as the vesicles become smaller. The mean period, however, is found to be remarkably robust for vesicle sizes down to approximately 200 nm, but the periodicity of the rhythm is gradually destroyed for smaller vesicles. The observed oscillations are explained as a canard-like limit cycle that differs from the wide class of conventional feedback oscillators.

Thermally active nanoparticle clusters enslaved by engineered domain wall traps.

The stable assembly of fluctuating nanoparticle clusters on a surface represents a technological challenge of widespread interest for both fundamental and applied research. Here we demonstrate a technique to stably confine in two dimensions clusters of interacting nanoparticles via size-tunable, virtual magnetic traps. We use cylindrical Bloch walls arranged to form a triangular lattice of ferromagnetic domains within an epitaxially grown ferrite garnet film. At each domain, the magnetic stray field generates an effective harmonic potential with a field tunable stiffness. The experiments are combined with theory to show that the magnetic confinement is effectively harmonic and pairwise interactions are of dipolar nature, leading to central, strictly repulsive forces. For clusters of magnetic nanoparticles, the stationary collective states arise from the competition between repulsion, confinement and the tendency to fill the central potential well. Using a numerical simulation model as a quantitative map between the experiments and theory we explore the field-induced crystallization process for larger clusters and unveil the existence of three different dynamical regimes. The present method provides a model platform for investigations of the collective phenomena emerging when strongly confined nanoparticle clusters are forced to move in an idealized, harmonic-like potential.

Deposition of a SiO2 Shell of Variable Thickness and Chemical Composition to Carbonyl Iron: Synthesis and Microwave Measurements.

Protective SiO2 coating deposited to iron microparticles is highly demanded both for the chemical and magnetic performance of the latter. Hydrolysis of tetraethoxysilane is the crucial method for SiO2 deposition from a solution. The capabilities of this technique have not been thoroughly studied yet. Here, two factors were tested to affect the chemical composition and the thickness of the SiO2 shell. It was found that an increase in the hydrolysis reaction time thickened the SiO2 shell from 100 to 200 nm. Moreover, a decrease in the acidity of the reaction mixture not only thickened the shell but also varied the chemical composition from SiO3.0 to SiO8.6. The thickness and composition of the dielectric layer were studied by scanning electron microscopy and energy-dispersive X-ray analysis. Microwave permeability and permittivity of the SiO2-coated iron particles mixed with a paraffin wax matrix were measured by the coaxial line technique. An increase in thickness of the silica layer decreased the real quasi-static permittivity. The changes observed were shown to agree with the Maxwell Garnett effective medium theory. The new method developed to fine-tune the chemical properties of the protective SiO2 shell may be helpful for new magnetic biosensor designs as it allows for biocompatibility adjustment.

MORPHOLOGICAL FEATURES OF RATS' HEARTS AFTER INTRAFETAL INJECTION OF DEXAMETHASONE.

OBJECTIVE: The aim: Is to study the morphological features of rats' hearts after prenatal administration of glucocorticoids. PATIENTS AND METHODS: Materials and methods: In this study we used histological, immunohistochemical, electron-microscopic and statistical research methods. RESULTS: Results: It is found that at 30th day after birth in rats after intrafetal introduction of dexamethasone in myocardium a relative area occupied by arterial vessels is significantly smaller in comparison with control. Absolute and relative number of Ki-67+-cardiomyocytes in the myocardium of experimental rats is reduced throughout the second week after birth and is significantly less compared to the control group. In the nuclei of cardiomyocytes of experimental rats is rendered the greater amount of heterochromatin in comparison with cardiomyocytes of the control group where euchromatin prevails. CONCLUSION: Conclusions: After intrafetal injection of dexametazone changes in dynamics and significantly smaller index of relative area occupied by arterial vessels in ventricular myocardium at the 30th day after birth are observed; the absolute and relative number of Ki-67+ -cardiomyocytes in myocardium decreases during the second week after birth and is significantly lower compared to the control group; in the nuclei of cardiomyocytes of experimental rats a greater amount of heterochromatin is visualized, and in cardiomyocytes of the control group - euchromatin.