Ventricular-arterial coupling assessed by PWV/GLS ratio in hypertensive patients.

OBJECTIVE: The physiological interaction between the left ventricle (LV) and the arterial system, defined as ventricular-arterial coupling (VAC), facilitates the optimal volume of cardiac work and cardiovascular performance. The aim of this study was to evaluate the benefit of PWV/GLS ratio associated with other vascular and cardiac performance parameters in hypertensive patients compared to age-matched healthy controls. PATIENTS AND METHODS: We calculated the ratio of pulse wave velocity (PWV), as a marker of arterial stiffness, to global longitudinal strain (GLS), as a marker of left ventricular function in 135 patients divided in 3 groups, as follows: group 1 (HT + CAD) enrolled 54 hypertensive patients with coronary artery disease, group 2 (HT) enrolled 43 hypertensive patients and group 3 (CON) represented the control group consisting of 38 age-matched healthy subjects. RESULTS: GLS values were significantly reduced in HT+CAD (-17.50±7.2) vs. HT (-17.95±5.3) vs. control (-20.13±4.6) (p-value <0.001). PWV values were higher in HT+CAD (9.90±3.1) and HT (9.70±2.5) vs. control (7.85±3.2) (p-value <0.001). VA coupling measured by the PWV/GLS ratio showed significantly lower values in HT+CAD and HT vs. control (p-value <0.001). The ROC curve identified a threshold of -0.054 of the PWV/GLS ratio to detect altered ventricular-arterial coupling AUROC = 0.836, 95% CI [0.762; 0.909]. CONCLUSIONS: This study demonstrated that assessment of the PWV/GLS ratio represents a useful tool to detect altered ventricular-arterial coupling in hypertensive patients. The perspectives of future use could include monitoring of earlier development of multiple organ damage in hypertensive patients and the efficacy of the different hypertensive medications. Extensive prospective studies are needed to confirm this hypothesis.

COVID-19 and cardiovascular manifestations.

OBJECTIVE: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), also known as COVID-19, a viral outbreak that started in December 2019, eventually lead to a worldwide pandemic. COVID-19 usually presents with flu-like symptoms, such as headaches, dry cough, fever, fatigue, myalgia, shortness of breath, diarrhea and loss of smell or taste. However, it can also have major effects on the cardiovascular system. Based on the available relevant literature, we aimed to elaborate the possible mechanisms influencing cardiovascular damage, myocardial injury and thromboembolic disease process in particular. MATERIALS AND METHODS: After considering our inclusion and exclusion criteria, the systematic review included 8 studies in total. RESULTS: In general, underlying cardiovascular diseases were associated with poorer clinical outcomes. This may be due to immunological dysregulation. The disease outcomes were also positively correlated with the severity of the disease, especially with myocardial injury. Thus, cardiac biomarkers, such as Troponin T, CK-MB and myoglobin could be utilized in prediction algorithms for deciphering the clinical outcome in COVID-19 patients. CONCLUSIONS: Venous thromboembolisms were commonly encountered complications despite the administration of thromboprophylaxis, and they mostly presented as pulmonary embolisms, warranting the need for relevant investigations in hemodynamically unstable patients. However, more studies need to be conducted to better understand the mechanisms at play and the ensuing complications, to better treat COVID-19 patients.

Adaptive Control of Nonlinear MIMO System With Orthogonal Endocrine Intelligent Controller.

In this article, a new intelligent hybrid controller is proposed. The controller is based on the combination of the orthogonal endocrine neural network (OENN) and orthogonal endocrine ANFIS (OEANFIS). The orthogonal part of the controller consists of Chebyshev orthogonal functions, which are used because of their recursive property, computational simplicity, and accuracy in nonlinear approximations. Artificial endocrine influence on the controller is achieved by introducing excitatory and inhibitory glands to the OENN part of the structure, in the form of postsynaptic potentials. These potentials provide a network with the capability of additional self-regulation in the presence of external disturbances. The intelligent structure is trained using a developed learning algorithm, which consists of both offline and online learning procedures: online learning for fitting OENN substructure and offline learning for adjusting OEANFIS parameters. The learning process is expanded by introducing the learning rate adaptation algorithm, which bases its calculations on the sign of the error difference. Finally, the proposed intelligent controller was experimentally tested for control of a nonlinear multiple-input-multiple-output two rotor aerodynamical system. During the test phase, an additional four related intelligent control logics and default PID-based controllers were used, and tracking performance comparisons were performed. The proposed controller showed notably better online results in comparison to other control algorithms. The major deficiencies of the structure are complexity and noticeably large training computation time, but these drawbacks can be neglected if tracking performances of a dynamical system are of the highest importance.

Mt-Keima detects PINK1-PRKN mitophagy in vivo with greater sensitivity than mito-QC.

PINK1 and PRKN, which cause Parkinson disease when mutated, form a quality control mitophagy pathway that is well-characterized in cultured cells. The extent to which the PINK1-PRKN pathway contributes to mitophagy in vivo, however, is controversial. This is due in large part to conflicting results from studies using one of two mitophagy reporters: mt-Keima or mito-QC. Studies using mt-Keima have generally detected PINK1-PRKN mitophagy in vivo, whereas those using mito-QC generally have not. Here, we directly compared the performance of mito-QC and mt-Keima in cell culture and in mice subjected to a PINK1-PRKN activating stress. We found that mito-QC was less sensitive than mt-Keima for mitophagy, and that this difference was more pronounced for PINK1-PRKN mitophagy. These findings suggest that mito-QC's poor sensitivity may account for conflicting reports of PINK1-PRKN mitophagy in vivo and caution against using mito-QC as a reporter for PINK1-PRKN mitophagy.Abbreviations: DFP: deferiprone; EE: exhaustive exercise; FBS: fetal bovine serum; OAQ: oligomycin, antimycin, and Q-VD-OPH; OMM: outer mitochondrial membrane; PBS: phosphate-buffered saline; PD: Parkinson disease; UPS: ubiquitin-proteasome system.

Mixture of Graphene Oxide/Phosphoric Acid/Melamine as Coating for Improved Fire Protective Performance and Enhancement of Surface Electrical Properties on Wood Chipboard.

Looking for multifunctional materials, an assessment of the performances both as fire retardant and generator of electrically conductive surfaces for a three component mixture of graphene oxide, phosphoric acid and melamine applied on wood chipboard was performed. A simple approach was used to investigate the intumescent char formation and quantify the loss mass during vertical burning tests, in which the prepared samples were exposed for a certain time interval to a flame generated by an ethanol lamp in ambient conditions. Moreover, mass loss evolution and structural changes that occur during the burning process were more comprehensive investigated by differential thermal and thermogravimetric (DTA/TGA) techniques. By comparing the performances between the wood chipboard samples without any coverage and those covered with one or multiple component mixture, an increase of protection against the fire action was noticed when the three component mixture was used. Also, an improvement of the electrical properties was observed, after flame exposure of the samples covered with multiple layers (i.e., two and three), when the three component mixture was used. Morphological and structural investigations by microscopy (optical and electronic-SEMEDX), X-ray diffraction (XRD) and spectral (Raman, FTIR) methods are described. An assessment of market potential is also discussed.

Mathematical Model of Sound Absorption by Lungs with Acoustic Stimulation of the Respiratory System.

According to the results of theoretical and experimental analysis of the characteristics of the propagation of acoustic vibrations in the respiratory system, it is necessary to determine the resonant frequency of the respiratory tract to increase the vital capacity of the lungs by opening reserve alveoli by acoustic stimulation of the respiratory system and then to affect the respiratory system with scanning tonal sounds in the maximum sound absorption range (at a level of ±3 dB of the maximum absorption coefficient value).

Markers of proliferation and cytokeratins in the differential diagnosis of jaw cysts.

We conducted a retrospective study to analyze the histologic and immunohistochemical findings in three main types of odontogenic cyst. We studied 90 archived cystic jaw lesions: 30 dentigerous cysts, 30 keratocystic odontogenic tumors, and 30 radicular cysts. The cyst types were identified on the basis of clinical, radiologic, and histopathologic findings. Immunohistochemical analyses included staining with Ki-67, p53, epidermal growth factor receptor (EGFR), cytokeratin (CK) 8, CK14, CK17, and CK18. Cell immunopositivity was evaluated for the entire epithelium. The criteria for Ki-67 and p53 positivity were dense and/or faint nuclear staining, and cells were considered EGFR-positive if they exhibited membrane staining and/or cytoplasm staining. For the cytokeratins, cells exhibiting cytoplasm staining were considered positive. Five representative fields of each lesion were selected and identified in each of the Ki-67- and p53-stained slides. We found a statistically significant difference in the ratio of Ki-67-positive cells in the entire layer between the keratocystic odontogenic tumors and both the dentigerous cysts and the radicular cysts. A statistically significant difference was observed in the ratio of p53-positive cells between the keratocystic odontogenic tumors and the radicular cysts. Cytokeratins proved to be useful in differentiating radicular cysts from other types of cystic jaw lesions because of their CK8-positive and CK17-negative immunolabeling.

Determination of heavy metals in muscle tissue of six fish species with different feeding habits from the Danube River, Belgrade-public health and environmental risk assessment.

The aim of this study was to investigate the presence of heavy metals/metalloids (Pb, Cd, Hg, Cu, Fe, Zn, As) in the muscle tissue of fish from the Danube River (two locations: Zemun and Grocka). For the purpose of heavy metal determination in fish muscle, 120 samples of six different fish species, Prussian carp, barbel, bream, carp, pike perch, and catfish were collected. For determining heavy metals, we used microwave oven digestion and atomic absorption spectrometer methods. The highest average content of Pb (0.084 ± 0.004 mg kg-1), Cd (0.082 ± 0.003 mg kg-1), Hg (0.466 ± 0.006 mg kg-1), and As (0.333 ± 0.007 mg kg-1) was found in the muscle of carp (an omnivorous fish) from Grocka, while the highest average level of Fe (13.60 ± 0.03 mg kg-1) was deposited in bream (also omnivorous) from Zemun. Also, the average Cu level (1.62 ± 0.13 mg kg-1) was the highest in catfish muscle (a carnivorous fish) from Grocka, while the highest Zn content (11.16 ± 0.17 mg kg-1) was determined in muscle of Prussian carp (an omnivorous fish) from Zemun. The highest content of heavy metals (Cu, Fe, and Zn, respectively) in muscle of the six different types of fish from both locations was symmetrically arranged by species (catfish, barbel, and Prussian carp, respectively). Concentrations of Pb, Hg, and As in the Danube River fish muscle were under the maximum residual levels prescribed by the European Union (EU) and the maximum allowed concentrations (MAC) for Serbia. On the other hand, in all fish muscle from both locations (Zemun and Grocka), higher concentrations of Cd than prescribed (MAC) were found, with the exception of bream and pike perch.

Adaptive PID control based on orthogonal endocrine neural networks.

A new intelligent hybrid structure used for online tuning of a PID controller is proposed in this paper. The structure is based on two adaptive neural networks, both with built-in Chebyshev orthogonal polynomials. First substructure network is a regular orthogonal neural network with implemented artificial endocrine factor (OENN), in the form of environmental stimuli, to its weights. It is used for approximation of control signals and for processing system deviation/disturbance signals which are introduced in the form of environmental stimuli. The output values of OENN are used to calculate artificial environmental stimuli (AES), which represent required adaptation measure of a second network-orthogonal endocrine adaptive neuro-fuzzy inference system (OEANFIS). OEANFIS is used to process control, output and error signals of a system and to generate adjustable values of proportional, derivative, and integral parameters, used for online tuning of a PID controller. The developed structure is experimentally tested on a laboratory model of the 3D crane system in terms of analysing tracking performances and deviation signals (error signals) of a payload. OENN-OEANFIS performances are compared with traditional PID and 6 intelligent PID type controllers. Tracking performance comparisons (in transient and steady-state period) showed that the proposed adaptive controller possesses performances within the range of other tested controllers. The main contribution of OENN-OEANFIS structure is significant minimization of deviation signals (17%-79%) compared to other controllers. It is recommended to exploit it when dealing with a highly nonlinear system which operates in the presence of undesirable disturbances.

Experimental study of displays in contralateral acoustic reflex auditory stimulation.

The results of an experimental study of manifestations of the acoustic reflex with contralateral auditory stimulation at a frequency of 1 kHz are presented, and the principal possibility and informativeness of its use for diagnosing the diseases of the organ of hearing are demonstrated. The principal difference of the developed approach is the use of polyharmonic signal for measuring acoustic reflex manifestations during contralateral stimulation, which allows accelerating the examination procedure.

Acute effects of nandrolone decanoate on cardiodynamic parameters in isolated rat heart.

Despite worldwide use of anabolic steroids in last decades, there is still contradictory information about their acute influence on myocardium. The aim of this study was to examine the acute effects of nandrolone decanoate (ND) on cardiodynamics and coronary flow in isolated rat heart. The hearts of male Wistar albino rats (n = 48, 12 per group, age 8 weeks, body mass 180-200 g) were excised and perfused according to the Langendorff technique at gradually increased coronary perfusion pressures (40-120 cmH2O). After the control sets of experiments, the hearts in different groups were perfused with different doses of ND (1, 10, or 100 µmol/L separately). Using a sensor placed in the left ventricle, we registered maximum and minimum rate of pressure development in the left ventricle (dP/dtmax and dP/dtmin), systolic and diastolic left ventricular pressure (SLVP and DLVP), and heart rate (HR). Coronary flow (CF) was measured flowmetrically. The results clearly show the depression in cardiac function caused by higher doses of ND. The highest concentration of ND (100 µmol/L) induced the most deleterious impact on the myocardial function and perfusion of the heart (coronary circulation), which could be of clinical significance.

[Occupational deafness in workers of locomotive crew and its association with risk factors].

The authors studied relationship between occupational neurosensory deafness and risk factors in locomotive crew workers. Examination covered 173 locomotive crew workers divided into 2 groups: group 1--with occupational neurosensory deafness (n = 85) and group 2--without occupational neurosensory deafness (n = 88). Study covered occupational factors and calculated effective dose connected to length of service for exposure assessment. Complex clinical and laboratory study was performed. For signs structure analysis, principal components method and chances ratio were used. Occupational neurosensory deafness appeared to be reliably connected with length of service, arterial hypertension, dyslipidemia--with OR equals 5.7 (95% CI: 2.98-11.00), 1.88 (95% CI: 1.03-3.43) and 2.79 (95% CI: 1.5-5.18) respectively. That necessitates correction of hypertension and dyslipidemia.

Unusual venous bullet embolism - Case report.

Bullet embolism is rare complication of penetrating gunshot trauma. We are presenting a case of a single gunshot with entrance wound located on external side of a left thigh. The upward directed trajectory extends to the left lateral side of the neck, but the bullet has been recovered from right external iliac vein. The bullet migration was explained due to one rare variation of the mouth of vena cava superior and inferior.

Outage capacity of FSO link with pointing errors and link blockage.

In this paper, we analyze the outage capacity performance of free-space optical (FSO) systems. More precisely, taking the stochastic temporary blockage of the laser beam, atmospheric turbulence, misalignment between transmitter laser and receiver photodiode and path loss into account, we derive novel accurate analytical expressions for the outage capacity. The intensity fluctuations of the received signal are modeled by a Gamma-Gamma distribution with parameters directly related to the wide range of atmospheric conditions. The analytical results are validated by Monte Carlo simulations. Furthermore, when the intensity fluctuations are caused only by atmospheric turbulence, derived expressions are reduced to the simpler forms already presented in literature. The numerical and simulation results show that the link blockage causes appearance of the outage floor that is a significant energetic characteristic of an FSO system. The results also show that there exists an optimal value of the laser beam radius at the waist for minimizing outage probability in order to achieve the specified outage capacity. This optimal value depends on atmospheric turbulence strength and standard deviation of pointing errors, but it is also strongly dependent on the probability of link blockage.

A new approach to the study of impedance characteristics of tympanic membrane.

A new approach to studying the tympanic membrane impedance characteristics, based on the analysis of polyharmonic acoustic signals reflected by the tympanic membrane, is described. For this purpose, the acoustic pressure and the phase difference between the acoustic vibrations in two sections of a waveguide sealingly connecting the external auditory meatus and a generator of polyharmonic audio signals is measured. By processing the results of measurements, the estimates of the frequency-dependent reflection coefficients, absorption coefficients, and components of the acoustic impedance of the tympanic membrane are calculated. The features that principally distinguish the developed approach from other approaches are the absence of the necessity to create a positive pressure in the external auditory meatus, the absence of ultrasonic radiation into the external auditory meatus and a high-intensity sound, and the possibility of direct measurement of the tympanic membrane impedance in the audio frequency range with any step.

Mathematical justification of the acoustic method for measuring the impedance of the respiratory tract.

A new method for measuring a complex frequency-dependent acoustic impedance of the respiratory tract based on two-microphone method was developed. The measuring device consists of a waveguide connected through a mouthpiece to the patient's mouth. A sound field with a frequency range from 5 to 100 Hz is created in the waveguide. The impedance of the respiratory tract is determined at free respiration of the patient in the set frequency range; the duration of examination does not exceed 15 s. The criteria for the recognition of respiratory tract pathologies are proposed.

Biphasic response of cardiodynamic adaptations to swimming exercise in rats.

The aim of research was to assess exercise-induced changes in mechanics of hearts isolated from rats, as well as time-course of those changes. Wistar rats (n = 42) were divided into control, moderately trained (swimming 1 hour, 5 days a week for 9 or 12 weeks) and strenuously trained (swimming 2, 3 and 4 times a day for an hour in weeks 10, 11 and 12, respectively) groups. After sacrificing, hearts (weight: 1480.82 ± 145.38 mg) were isolated and perfused on a Langendorff apparatus. Coronary perfusion pressure (CPP) was gradually increased (from 40 to 120 cm H(2)O) in order to establish coronary autoregulation. Parameters of cardiac contractility were recorded: maximum and minimum rate of change of pressure in the left ventricle (dp/dt max and dp/dt min), systolic and diastolic left ventricular pressure (SLVP and DLVP), heart rate (HR) and coronary flow (CF). Nine weeks of moderate exercise induced slight depression of coronary function (decrease of dp/dt max, dp/dt min, SLVP and DLVP), while 3 additional weeks of moderate training improved hearts function, but not to the extent that the strenuous training program did. The results of our study add evidence about beneficial effects of regular moderate exercise on heart, and furthermore, show that exercising frequently, if the intensity stays within moderate range, may not have detrimental effects on cardiodynamics.

Polyphenols-rich natural products for treatment of diabetes.

Currently, experimental and clinical evidences showed that polyphenols-rich natural products, like nutraceuticals and food supplements, may offer unique treatment modalities in type 2 diabetes mellitus (DM), due to their biological properties. Natural products modulate the carbohydrate metabolism by various mechanisms, such as restoring beta-cells integrity and physiology, enhancing insulin releasing activity, and the glucose using. Sea buckthorn berries, red grapes, bilberries, chokeberries and popular drinks like cocoa, coffee and green tea are all rich in polyphenols and may decrease the insulin response, offer in g a natural alternative of treatment in diabetes. Therefore, researches are now focused on potential efficacies of different types of polyphenols, including flavonoids, phenolic acids, lignans, anthocyans and stilbenes. Animal and human studies showed that polyphenols modulate carbohydrate and lipid metabolism, decrease glycemia and insulin resistance, increase lipid metabolism and optimize oxidative stress and inflammatory processes. It is important to understand the proper dose and duration of supplementation with polyphenols-rich extracts in order to guide effective therapeutic interventions in diabetic patients.