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Introduction: Platelets play an important role in the pathogenesis of COVID-19. Therefore, their parameters vary in different stages of the disease. The importance of plateletcrit in COVID-19 is not well known. Objective: To examine the diagnostic value of plateletcrit in COVID-19. Methods: From January to March and September-December 2021. during their initial visit to the COVID outpatient clinic at the Primary Healthcare Center Nis, we examined 440 patients who were experiencing possible COVID-19 symptoms. Following the examination, a complete blood count was performed, and they tested positive for COVID-19. We analyzed the plateletcrit in every lab sample collected during their first visit. The control group consisted of 60 patients from the "green zone" from January to December 2021, as well as 48 patients from the pre-COVID period, before 2020. Results: Lower plateletcrit was found in 48,4% of women and 63,3% of men in the first period. Out of the total of 111 patients, lower plateletcrit was found in 54,9%. in the second period lower plateletcrit was found in 72,2% of women and 85% of men. Out of the total number of 329 patients, lower plateletcrit was found in 78,7%. In the control group, from the "green zone" lower plateletcrit was found in 8,3% of 60 patients, and no decrease in plateletcrit levels was observed in 48 patients from the pre-COVID-19 era. Conclusion: Plateletcrit levels are decreased in many patients during their initial visit due to COVID-19. Symptoms. Therefore, variations in plateletcrit levels could raise concerns about potential COVID-19 infection.

The reproductive efficiency of the cows was monitored after two resynchronization protocols: Ovsynch (OVS) and Double Ovsynch (DOS). The research initially included 70 HF cows who entered the first synchronization protocol – Presynch. Cows that did not conceive after the first synchronization were divided into two groups and introduced to two resynchronization protocols. In the first group of cows (n=35), the DOS protocol began with the application of GnRH on day 22 after the Presynch TAI (Timed Artificial Insemination), and seven days later pregnancy check-up was done and PGF2α was applied only to non-pregnant cows (n=23), which remained in the study. In the second group of cows, the OVS protocol started on day 32 after Presynch TAI only in non-pregnant animals (n=20). Progesterone (P4) concentration was determined at the time of application of GnRH1, PGF2α and GnRH2 in both groups of cows, and then 30 days after Resynch TAI, ultrasound pregnancy diagnosis was done. A higher percentage of pregnant cows were recorded in the OVS group compared to the DOS group (45% and 35%, respectively). The concentration of P4 in the serum of cows in the DOS group during the first measurement (GnRH1) was significantly higher than the value in cows that did not conceive (p

Depopulation of mountains has been an intense and lengthy process in Serbia. This paper will analyze the potential of Kopaonik mountain for the development of tourism, which can be one of the key factors for the demographic revitalization of the entire mountain. In tourism development so far, Kopaonik mountain stands out as one of the most important carriers of mountain tourism in Serbia. The limiting factor in the development so far is the pronounced seasonality of tourism promotion. The aim of the research in the paper will be to identify the factors that influence seasonality phenomena as the main limiting factor for achieving better economic effects.

A load angle limiter was implemented as an additional function in the existing excitation system to enable the operation of the synchronous generator in the entire P-Q diagram according to the recommendation of the manufacturer of the unit B2 synchronous generator in the "Nikola Tesla B" TPP. The analysis of dynamic performance presented in this paper consists of determining the time responses and frequency characteristics of the excitation control system when the load angle limiter is active, based on which the values of the dynamic performance indexes were obtained. In addition, the paper also provides a brief description of the implementation of the limiter, as well as a description of the computer models used in the analysis.

Five Artemisia species (seven A. alba Turra samples and twelve samples of each four remaining species: A. absinthium L., A. annua L., A. vulgaris L. and A. scoparia Waldst. & Kit.) from Serbia were studied from the aspect of essential oil chemical composition, and potential correlations between essential oil composition with soil type determined using World Reference Base for Soil Resources (WRB). A great variety in essential oil composition was observed for A. alba, A. absinthium and A. vulgaris samples, while in the case of A. annua, as well as A. scoparia, the composition of the examined essential oils was more uniform. Principal component analysis (PCA) and agglomerative hierarchical clustering (AHC) showed that there is no significant effect of soil type on the Artemisia essential oil composition while Mantel test showed that there is a correlation between samples within A. vulgaris, as well as A. scoparia and the geographical distances of the localities from which these samples were collected.

Introduction/Objective Diabetic ketoacidosis (DKA) is a common and most severe acute complication of diabetes. It is a severe metabolic disorder with a high morbidity rate. This article aims to examine patients hospitalized for DKA during a one-year timeframe, present their findings and determine the precipitating factors for the occurrence of DKA. Methods The retrospective study included 63 patients with DKA. The research was performed using descriptive statistics based on demographic data (age and gender) and laboratory findings (blood sugar value, pH value and blood bicarbonate level). Results The obtained results show that out of 63 patients, 20 (31.74%) were male and 43 (68.26%) female. The average age of male patients was 56.25 ±18.25 SD years and the average age of female patients 49.75 ± 14.42 SD years. The total average was 53.71±15.58 SD years. The total number of Type 1 diabetes patients was 29 (46.03%), 12 of which were male and 17 female. The total number of Type 2 diabetes patients was 34 (53.97%), 8 of which were male and 26 female. Blood sugar values on admission were 24.36±7.68 SD mmol/L, ph values 7.14±0.12 SD and bicarbonate values 11.2±3.76 SD mmol/L. Ketone bodies were measured qualitatively in urine samples marked as “+” to “+++” and therefore not included in the statistics. The patients had been diagnosed with diabetes for 15.2 ±8.3 SD years before hospitalization and their hospitalization lasted 7.89 ±2.87 SD days. The required time for resolving ketoacidosis was 16.21±12.02 SD hours. The time required to begin the administration of the GIK (glucose, potassium, insulin) regimen as a form of therapy was 4.88 ±2.33 SD hours. Blood sugar levels when switching to the GIK solution were 10.9±0.32 SD mmol/L. The most common precipitating factor for DKA was infection (48.32%), followed by the absence of insulin in therapy (43.13%), while other causes accounted for 8.55% of the cases. Conclusion Treating patients with DKA was based on current therapeutic algorithms. Our oneyear study presents their findings and treatment protocols. Since the incidence of diabetes mellitus is on the rise, its complications are also becoming more frequent which is why prevention is much needed.

In this paper a load angle estimation method of round rotor synchronous generator is presented, for load angle limiter in AVR systems design purpose. To get information of load angle, it is necessary to have values of the one terminal voltage, one phase current and q-axis reactance Xq. Mentioned values are acquired by synchronous sampling technique and processed by discrete Fourier transformation. The accuracy of presented method highly depends on quality of zero-crossing detection of the input voltage signal and on the calculation estimation of the fundamental frequency. This method is of reduced sensitivity to higher harmonics presence contence in voltages and current waveforms. Another advantage, when compared to other dq or ab based calculations estimations, is the necessity of use only two measurement channels. Drawback of described approach is lack of immunity to current asymmetry. However, a solution to overcome this problem is offered by introducing the additional measurements into the algorithm to extract the synchronous sampled direct components of all three phase currents.

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Among radionuclides in the soil deposited after Chernobyl accident, 137Cs poses considerable environmental and radiological problems because of its relatively long half-life (30.17 y), its abundance in the fallout, high mobility and similarity to potassium as the major plant nutrient. In this study the samples of undisturbed surface soil (n=250) were taken from 70 regions in Belgrade, during 2006-2010. The specific activities of 137Cs were measured by gamma-ray spectrometry. Based on obtained results external effective dose rates were calculated according to the internationally accepted activity to dose rate conversion equations. The specific activities of 137Cs were geographically mapped. The presence of 137Cs has been detected in all soil samples, with high variability of its specific activity, ranging from 3 Bq kg-1 to 87 Bq kg-1. The mean specific activity of 137Cs was 23 Bq kg-1 and the corresponding absorbed dose was 1.5 nSv h-1. The observed range reflects the inhomogeneity of the deposition process following the Chernobyl accident. It could also be attributed to topographic differences and spatial differences in physicochemical and biological soil properties, soil type and vegetation cover. The results of the present study could be valuable database for future estimations of the impact of radioactive pollution.

In the common industry and especially in military industry there is a growing need for production of highly effective protective structures. For that purposes the most used materials are armor steels. They belong into a group of the fine-grained, increased strength steels, which are manufactured by intensive thermo-mechanical treatment at high temperatures and later quenching and low-tempering. Combination of the heat and mechanical treatments provides for the fine grains and exceptionally good properties of these steels, while the low-tempering enables relatively high hardness and good ballistic properties. However, sometimes there is a need to weld these steels in order to manufacture some specific assemblies. Since the way these steels are produced this is why the welding can negatively affect the material properties in specific zones of the welded joint, what could lead to worsening of the material's ballistic properties, as well. The aim of this paper was to determine influence of the welding procedure on that mechanical and ballistic properties. In that order the model plates were welded with the specially prescribed technology in three types of the joints: the butjoint, corner joint and the corner joint with the shielding plate. After the welding the test plates were subjected to the ballistic tests which consisted of shooting with three types of live ammunition at different types of the welded joints. At the end the comparative analysis of the results is given. [ABSTRACT FROM AUTHOR]

Background: A rapid increase in the turnover of malignant cells modulates the enzymes level in circulation and may be a prognostic sign of disease progression. We evaluated the activity of serum lactate dehydrogenase and superoxide dismutase in erythrocytes of breast cancer patients immediately after surgery and before adjuvant therapy. Methods: Fourteen newly operated breast cancer patients were included in the study. Lactate dehydrogenase and superoxide dismutase activity were estimated using standard tests for evaluation of enzyme activity. Results: Activity of lactate dehydrogenase was in normal range in all but one sample obtained from patient at clinical status IIIB. Superoxide dismutase activity was elevated in 11 out of 14 patients, and was 2 to 8 fold higher compare to control values. The highest activity of superoxide dismutase was found in samples of two patients at clinical status I. Conclusion: Determination of lactate dehydrogenase and superoxide dismutase activity might be useful in clinical follow up of breast cancer patients.