Background: Video-assisted thoracic surgery (VATS) for both minor and major thoracic procedures has become routine practice worldwide. In this study, we present our experience with multiportal and uniportal VATS (MVATS and UVATS) in Bosnia and Herzegovina (B&H). MVATS and UVATS procedures were performed in two B&H Clinical Centers: Tuzla and Sarajevo. The first MVATS procedure at Tuzla Clinical Center was conducted in 2004, and the first UVATS lobectomy was performed in 2019. At Sarajevo Clinical Center, the initial MVATS took place in 2005, and the first UVATS lobectomy was carried out in 2020. Methods: We retrospectively analyzed 401 VATS procedures with prospective data, collected between 06/2017 and 04/2023. The VATS technique was employed for wedge resections, partial resections, lobectomies, and other types of resections, including metastasectomy. Results: Out of the 401 patients, 242 (60.34%) were male, and 159 (39.66%) were female, with a mean age of 57.2±23 years. The procedures consisted of 231 UVATS and 170 MVATS. Lobectomy was performed in 61 (15.21%) cases, wedge resections in 216 (51.37%), partial resections in 85 (21.19%), and other types of resections in 39 (9.72%) patients. The median duration of the procedure was 210 minutes for lobectomy, and 77.5 minutes for wedge and other types of resections. Major complications, such as bronchopleural fistula in 22 (5.49%) cases, wound infections in 20 (4.99%), atelectasis in 19 (4.74%), lung infiltrations in 15 (3.74%), and bleeding in 15 (3.74%) patients, were observed. The overall mean hospital stay for all procedures was 6.45 days. Conclusion: Uniportal and multiportal VATS techniques are feasible and safe for various indications in thoracic surgery. VATS can be performed in middle-income countries such as Bosnia and Herzegovina with acceptable results, by thoracic surgeons experienced in general thoracic surgery

Background: This research paper is an expression of a desire to view COVID 19 from the perspective of a spontaneous hemorrhage induced on different organ systems. Introduction of a stratified approach to the problem of hemorrhage has become an imperative in medical treatment. Aim: To determine the real figure of spontaneous hemorrhage cases in severe forms of infections caused by Covid 19.Material and methods: The research included 745 patients that suffered from severe forms of infections caused by Covid 19 who were treated in a Respiratory clinic in Tuzla University Clinical Center during 2020 and 2021. The spontaneous hemorrhage was determined on the grounds of laboratory parameters of blood counts and CRP, hemodynamic monitoring of TA and pulse, and CT imagining diagnostic technique.Results: The study presents information about the medical treatment outcome in the case of 5 patients (0,67%) who experienced spontaneous hemorrhage as a part of Covid 19 infection in relation to the total number of 745 patients who were treated during that period in the Respiratory clinic as Covid patients with severe forms of infection. Out of 5 patients who acquired spontaneous hemorrhage 3 were operated. For 4 patients the outcome was lethal. One of the female patients who was in the group of those who were not operated and who had undergone a conservative treatment has survived. In our group of analyzed patients two patients suffered from the hematoma of the front abdominal wall, two had retroperitoneal hematoma and one patient acquired hemorrhage in the abdomen and thoracic with the developing DIC.Conclusion: Relatively low percentage of cases developing spontaneous hemorrhage 5 (0, 67%) but relatively high mortality rate in the cases where it did occur, 4 out of 5 monitored patients, requires certain suggestions that are being presented in this study as to how to approach the cases of spontaneous hemorrhage in the severe forms of Covid 19 infections in more consistent manner in order to improve the outcome of the medical treatment of these cases.

The development of science is essential when it comes to the development of society, while the mathematics necessary for the development of science. The fact that the children are all clearer, more capable and versatile, and their mathematical knowledge smaller and worse, motivated me to this research.How would our society be better you need to choose talented and creative young people who will represent the same company. One way of selecting children, and choosing the best are just competitions. In this work, attention will be focused on additional classes and competitions of teaching mathematics, as well as their importance in the education and development of children in schools.When it comes to gifted students, one of the main events where they can demonstrate their knowledge and skills are the competition.The overall objective of this research is to determine the extent to which the additional classes represented in schools and how many students go to additional classes and competitions in mathematics.The study included 103 primary school students in the municipality of Ilijaš. The results obtained in this study mostly on the representation of additional teaching of mathematics in schools or with, a small number of students. Because the necessary mathematical talent, the will and desire to learn mathematics. Viewed from the perspective that the disciples mathematics not so favorite subject, these are the expected results.

This paper presents a new approach for solving decentralized bi-level multi-objective linear fractional programming problems. The main goal was to find a simple algorithm with high confidence of decision-makers in the results. First, all the linear fractional programming models on the given set of constraints were solved separately. Next, all the linear fractional objective functions were linearized, membership functions of objective functions and decision variables controlled by decision-makers at the highest level calculated, and a fuzzy multi-objective linear programming model formed and solved as linear goal programming problem by using simplex algorithm. The efficiency of the proposed algorithm was investigated using an economic example, and the obtained results compared with those obtained using an existing method.

In this study, we analyzed the emotional and conative characteristics of fourth grade students of elementary school as follows: motivation for learning math, situational interest in learning mathematics during teaching, mathematics anxiety, self-esteem in relation to academic achievement and attributions of success and failure in mathematics. In a sample of 200 students and 20 teachers were analyzed emotional and conative characteristics capable of above-average and below average in math-age students. The study used the descriptive method, a questionnaire and a test. The research results are presented graphically and in tabular form with an explanation and discussion. In the conclusion are set the directions which should further improve this insufficiently studied area.

Contemporary learning processes in schools and universities could not be imagined without the use of computers and calculators. Naturally, all is good if they are used in order to acquire new knowledge or solve problems from expert subjects in technical schools, which demand large quantity of simple mathematical operations. However, what if frequent use of calculators, either pocket or those installed on every home and school computer, becomes an addiction in students who begin using them while calculating simple mathematical operations, such as multiplying or adding and detracting one-digit numbers or numbers smaller than 20, when they should know this by heart? We arrived at this hypothesis during knowledge tests for students after regular demonstrations and elaborations of Mathematics subject matter. In order to confirm or deny this hypothesis, generic/developmental method, that is, survey was used as one of research techniques (Selimović, 2013., p. 104). The survey was conducted in March during academic 2016/2017 and the sample consisted of 59 students in 2nd grade of Grammar School Tešanj.

This paper presents and analyzes the applicability of three linearization techniques used for solving multi-objective linear fractional programming problems using the goal programming method. The three linearization techniques are: (1) Taylor’s polyno-mial linearization approximation, (2) the method of variable change, and (3) a modification of the method of variable change proposed in [20]. All three linearization techniques are presented and analyzed in two variants: (a) using the optimal value of the objective functions as the decision makers’ aspirations, and (b) the decision makers’ aspirations are given by the decision makers. As the criteria for the analysis we use the efficiency of the obtained solutions and the difficulties the analyst comes upon in preparing the linearization models. To analyze the applicability of the linearization techniques incorporated in the linear goal programming method we use an example of a financial structure optimization problem.

Fractions represent the manner of writing parts of whole numbers (integers). Rules for operations with fractions differ from rules for operations with integers. Students face difficulties in understanding fractions, especially operations with fractions. These difficulties are well known in didactics of Mathematics throughout the world and there is a lot of research regarding problems in learning about fractions. Methods for facilitating understanding fractions have been discovered, which are essentially related to visualizing operations with fractions.