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Introduction/Objective. Although cardiac tumors in the pediatric population are found infrequently, their occurrence is constant and with occasional variations. The purpose of this study is to show our experience with surgical options of these masses in two leading national university-level pediatric centers over four decades. Methods. This retrospective study is presenting a total number of 24 surgically treated pediatric patients who have been operated on 1998?2020. There were 16 children with primary masses and eight children with metastatic cardiac tumors. Two patients with tumor-like intracardiac masses were not included in the series but had been mentioned as diagnostic challenges. Our patients did not have cardiac transplantation options. Results. The average age of our patients was five and a half years, and the most frequent operated tumor was the cardiac myxoma. Four children had neurological symptoms. There were two deaths, one in the primary tumor group and one metastatic patient misdiagnosed as a primary tumor in the early ages of our department. We had two recurrent cases, a girl with Carney complex, and an infant with an extremely rare form of cardiac malignancy after a myxoma extraction. One child required a permanent pacemaker insertion. Conclusion. Although rare, the pediatric cardiac tumors can be a source of different life-threatening conditions and lifelong sequelae. Therefore, special considerations should be paid to the diagnostic and surgical modalities of their treatment.

Background/Aim. Chronic microbial infections of the root canal are a common issue. This process very often causes an immune reaction in the root canal system that results in forming of chronic periapical lesions (PLs). The aim of this study was to determine the quantitative expression of the bacterial heat shock protein (HSP), chaperonin 60 (cpn60), and the pro-inflammatory and anti-inflammatory cytokines in periapical tissue obtained from individuals with chronic PLs and to determine if there is a correlation between the expression of the bacterial HSP and the expression of these cytokines. Methods. The study was performed on 18 PLs and 6 control samples of healthy periapical tissue, taken at the Department of Dentistry, Faculty of Medicine, University of Pristina/Kosovska Mitrovica. The levels of messenger ribonucleic acid (mRNA) expression of pro- and anti-inflammatory cytokines and bacterial HSP were determined by quantitative real-time polymerase chain reaction (RT-PCR) and quantified by comparing to the internal control gene for glyceraldehyde 3-phosphate dehydrogenase (GAPDH). Results. Analysis revealed significantly higher mRNA levels of tumor necrosis factor-alpha (TNF-a) and cpn60 in the tissue of PLs compared with normal periapical tissue (p < 0.05). Contrary to these results, the mRNA expression of anti-inflammatory interleukin-10 (IL-10) was significantly higher in the samples of normal periapical tissue compared with the mRNA levels of this cytokine in the tissue of PLs (p < 0.001). Expression of cpn60 is in strong correlation with TNF-a expression in PLs. Conclusion. cpn60 released from bacteria in periapical tissue could be a strong stimulator of inflammatory response and one of the important players in the pathogenesis of PLs.

Let G = (V, E), V = {v1, v2,..., vn}, be a simple graph without isolated vertices, with the sequence of vertex degrees d1 ? d2 ?...? dn > 0, di = d(vi). If vertices vi and vj are adjacent in G, we write i ~ j, otherwise we write i ~/ j. The inverse degree topological index of G is defined to be ID(G) = ?ni=1 1/di = ? i~j (1/d2i + 1/d2j), and the inverse degree coindex ?ID(G) = ? i~/j(1/d2i + 1/d2j). We obtain a number of inequalities which determine bounds for the ID(G) and ?ID(G) when G is a tree.

The zeroth-order general Randic index, 0R?(G), of a connected graph G, is defined as 0 P R?(G) = ni =1 d?i , where di is the degree of the vertex vi of G and ? arbitrary real number. We consider linear combinations of the 0R?(G) of the form 0R?(G) ? (? + ?)0R??1(G) + ?? 0R??2(G) and 0R?(G) ? 2a 0R??1(G) + a2 0R??2(G), where a is an arbitrary real number, and determine their bounds. As corollaries, various upper and lower bounds of 0R?(G) and indices that represent some special cases of 0R?(G) are obtained.

Let G = (V, E), V = {v1, v2,..., vn}, be a simple connected graph of order n and size m, without isolated vertices. Denote by d1 ? d2 ?... ? dn, di = d(vi) a sequence of vertex degrees of G. The general zeroth-order Randic index is defined as 0R?(G) = ?ni =1 d?i, where ? is an arbitrary real number. The corresponding general zeroth-order Randic coindex is defined via 0R??(G) = ?ni=1(n?1?di)d?i. Some new bounds for the general zeroth-order Randic coindex and relationship between 0R??(G?) and 0R???1(G?) are obtained. For a particular values of parameter ? a number of new bounds for different topological coindices are obtained as corollaries.

The goal of this paper is to study the properties of zeros of some special quaternionic polynomials with restricted coefficients, namely coefficients whose real and imaginary components satisfy suitable inequalities. We extend the well-known Enestr?m-Kakeya theorem and its various generalizations from complex to the quaternionic setting. The main tools used to derive the bounds for the zeros of these polynomials are the maximum modulus theorem and the structure of the zero sets established in the newly developed theory of regular functions and polynomials of a quaternionic variable.

Introduction. The aim of our research is to determine the breakdown value of vitamin B12 in the blood that causes mild cognitive impairment. Material and Methods. Two hundred respondents participated in this research. Using screening tests, mild cognitive impairment was found in 50 patients, while in 150 patients the cognitive function was preserved. Borderline values and units of vitamin B12 concentration were determined according to the standards of the local laboratory and their reference values ranged from 138.00 to 652.00 pmol/l. Results. Using the t-test for independent samples, it was determined that there was a statistically significant difference in the values of vitamin B12 in relation to whether or not the respondents had mild cognitive impairment (? = 0.000), i.e. that respondents with mild cognitive impairment - 225.66 had significantly lower values of vitamin B12 than those without mild cognitive impairment - 421.06. The statistic analysis revealed that the area under the receiver operating characteristic curve was significantly above 0,5 (0.968) and this result was statistically significant (? < 0.0005). The breakdown value of vitamin B12 was determined as the maximum product between sensitivity and specificity. Conclusion. In this research, we determined that there was a statistically significant difference in the values of vitamin B12 in relation to whether or not the respondents had mild cognitive impairment. Being a significant risk factor for mild cognitive impairment, we defined the breakdown value of vitamin B12 which induces mild cognitive impairment of 300.5 pmol/l.

This study investigates the effects of successive neutron and gamma radiation on the parameters of commercial solar cells. Several solar panels have been exposed to neutron radiation and then, after 30 days of recovery, to gamma radiation. A series of measurements of solar cell parameters have been undertaken to determine the reliability of solar cells in the condition of successive irradiation of different types of rays. Solar cell parameters have been measured before and after every step of irradiation. The process of annealing has also been observed. This paper aims to present the effects of both neutron and gamma radiation on the same solar cell sample.

In this study, we used leaf geometric morphometrics to quantify the differences among Quercus cerris L. and Quercus frainetto Ten. and their populations in the Sumadija region in Serbia. We sampled 2200 leaves from eight populations and on each leaf recorded 13 landmarks. To analyze how leaf morphology varies across species and populations, we used Procrustes ANOVA, a two-block partial least-squares analysis, a principal component analysis and a canonical variate analysis. The results showed a clear discrimination between species, followed by different levels of leaf shape variability in Q. cerris and Q. frainetto. The leaves of Q. cerris displayed higher levels of variability and higher differences among populations compared to Q. frainetto. The patterns of population grouping in the two species greatly differed, indicating that in these species different factors contribute to intraspecific variability. This study provides preliminary results of the leaf morphometric variability of oak species in the Sumadija region in Serbia. Future studies should include genetic and environmental analyses to understand the origins of phenotypic differences between species and populations, and to fully recognize which factors mostly determine relationships between taxa.

It is well-known that there is no PLAN-DO-CHECK-ACT (PDCA) approach that is used by electricity distribution network operators and asset managers of power cable systems. Accordingly, this paper proposes a novel application of the PDCA approach to thermal aging management of underground power cables in electricity distribution networks. Another novelty of the proposed approach is that the finite element method (FEM) is used in combination with the traditional Arrhenius model to calculate the unknown temperature of cable conductors under service conditions. In particular, this means that the FEM-based Arrhenius model can involve the effects of other heat sources, wind, solar irradiation, etc., in procedures for qualification of underground power cables. The Arrhenius model is applied to an actual hot spot of a 110 kV underground cable line of most importance to reliable operation of the electricity distribution network of the city of Belgrade. In the hot spot, the 110 kV cable line is installed in parallel with the group of 35 kV cables and crosses an underground heating pipe-line. The proposed approach is successfully validated using the existing experimental data on cross-linked polyethylene insulation. Finally, it is found that the hot spot effect can shorten the expected total service lifespan of the 110 kV cables in the hot spot area by 36.84%, as well as that the largest consumption of total thermal lifespan occurs in the presence of all the existing thermal effects.

The paper presents the results of the genetic diversity analysis of Sessile oak populations from the area of outstanding natural beauty (AONB) "Avala" which were obtained using SSR markers. Genomic DNA was isolated from leaf tissue of 50 test trees from two populations. Genotyping was performed using microsatellite markers QpZAG110, QpZAG15, QpZAG1/2, QpZAG3/64, QpZAG36, QpZAG1/5, and QrZAG108. All loci were polymorphic with the high mean value of PIC (0.934). The total number of alleles determined in the studied population was 127. The range of alleles varies from 15 (QpZAG1/5, QpZAG1/2) to 23 (QpZAG110) with an average of 18.14 alleles per locus. The number of effective alleles ranges from 8.273 (QpZAG1/5) to 13.830 (QrZAG108). The mean value of the gene flow (Nm) was 8.522 with a range from 5.548 to 14.876. Overall genetic diversity was high (He = 0.909) and ranged from 0.879 to 0.928. Due to the excess of homozygotes observed at most loci, a significant inbreeding coefficient was detected (Fis = 0.796). The Analysis of Molecular Variance (AMOVA) confirmed that genetic diversity was more pronounced within populations (77.5%) than between them (1.6%). The average allele frequency (Q) of the studied populations shows that the individuals originate from two or more populations. The obtained results can be used for the adoption of appropriate plans for the management of protected natural resources and the management of this ecologically and economically important tree species. Also, the obtained results enable the adoption of the necessary measures for the conservation of sessile oak genetic resources by in-situ and ex-situ methods. Based on the research results, the use of this important species can be recommended for its reintroduction in optimal microclimatic conditions, as well as in the selection of the best individuals for the reintroduction.

Introduction. Angiosarcomas (ASs) arising from vascular tissue, account for 3.3% of all sarcomas and have a poor prognosis. Radiation-induced AS is a rare late complication of radiotherapy (RT) treatment and is characterized by a gene expression profile such as amplification of the MYC oncogene, by which we can distinguish primary from secondary induced tumor. Case report. For a 77-year-old female patient with early-stage endometrial adenocarcinoma, a radical hysterectomy with bilateral salpingo-oophorectomy was initially done. According to pathological risk factors, the postoperative external beam conformal RT (CRT) of the pelvis was administered with concomitant brachytherapy. Six years after the treatment, on the anterior abdominal wall, in the region of the postoperative irradiation field and surgical scar, an infiltrative AS of the skin and subcutaneous adipose tissue was histologically confirmed. The patient received six cycles of mono-adriamycin chemotherapy with verified partial regression. Additional immunohistochemical analysis (IHC) of c-MYC, Ki67, and CD34 expression showed a high proliferative index (Ki67 around 60%) and c-MYC positivity indicating the molecular pattern of radiation-induced AS. Furthermore, the high proliferative index could explain the positive response to chemotherapy. Conclusion. The novel postoperative RT techniques provide better survival and local control in risk-endometrial cancer groups with a decrease in irradiation complications. These patients with longer survival are at a higher risk of developing radiation-induced tumors as late side-effects of RT. When assessing the probability of radiation-induced AS, IHC analysis of c-MYC expression could distinguish secondary from other AS if Cahan?s criteria are fulfilled.

Leaf morphology is at a certain level defined by the ways in which plants adapt to different habitats, especially in large trees. In this study, morphological variations in leaf size and shape of the Hungarian oak (Quercus frainetto Ten.) growing on different soil types (lithic leptosol, vertisol, cambisol) were investigated in the central part of Serbia (Sumadija). The information on soil type was obtained using a digitalized soil map of the Republic of Serbia, while leaf traits were characterized by geometric morphometric methods. Landmark analysis and leaf measurements showed significant differences among the analyzed groups, with individuals growing on nutrient-poor, shallow soils having smaller leaves with greater lobation. The observed differences suggest that the levels of soil productivity influence variations in leaf patterns. More studies on a larger sample size and along a broader spatial scale are needed to fully understand the differences in the patterns of leaf morphological variation in Q. frainetto.

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Background/Aim: Numerous histopathological parameters, such as cartilage penetration, perineural and lymphovascular invasion, presence of metastatic tissue in regional lymph nodes, extranodal extension of nodal metastases, as well as presence of cancer tissue on resection borders, are all important factors influencing survival in patients with laryngeal squamous cell carcinoma. A retrospective study was conducted in order to determine association between cancer surface area and these histopathological characteristics. Presence of extranodal extension of metastatic tissue in regional lymph nodes was also investigated. Methods: We revised 140 cases of laryngeal squamous cell carcinoma, processed after total laryngectomy, that were found in archives of Histopathology laboratory of Clinic for Otorhinolaryngology and Maxillofacial Surgery, Clinical Centre of Serbia. Results: A significant difference in cancer surface area was found depending on penetration of thyroid cartilage, perineural invasion and positive resection margins. Cancers with greater surface area were more commonly of higher T stage. Metastases were found in 36 out of 72 neck lymph node samples submitted to evaluation (50%). Difference in cancer surface area was also found depending on presence of metastatic tissue in regional lymph nodes. Extranodal extension was present in 69.4% of involved lymph nodes, and it was more frequent in lymph nodes 3cm in size or larger. Conclusions: There is a significant difference in cancer surface area depending on presence of cartilage penetration, perineural invasion, presence of cancer tissue on resection borders and presence of metastases in regional lymph nodes. Bigger cancers tend to be of a bigger T stage. Extranodal extension is more common in lymph nodes 3cm in size or larger.

Let G = (V,E), V = {v1, v2,..., vn}, be a simple connected graph of order n and size m, with vertex degree sequence d1 ? d2 ? ...? dn. A graph G is said to be regular if d1 = d2 =... = dn. Otherwise it is irregular. In many applications and problems it is important to know how irregular a given graph is. A quantity called degree deviation S(G) = ?ni=1 |di-2m/n| can be used as an irregularity measure. Some new lower bounds for S(G) are obtained. A simple formula for computing S(G) for connected bidegreed graphs is derived also. Besides, two novel irregularity measures are introduced.

Let G = (V,E), V = {1,2,...,n}, be a simple connected graph of order n, size m with vertex degree sequence d1 ? d2 ? ... ? dn > 0, di = d(vi). The geometric-arithmetic topological index of G is defined as GA(G) = ? i~j 2? didj/di+dj, whereas the geometric-arithmetic coindex as GA?(G) = ? i~/j 2 ? didj/di+dj . New lower bounds for GA(G) and GA(G) in terms of some graph parameters and other invariants are obtained.

Let G be a simple connected graph of order n and size m, vertex degree sequence d1 ? d2 ?...? dn > 0, and let ?1 ? ? 2 ? ... ? ?n-1 > ?n = 0 be the eigenvalues of its Laplacian matrix. Laplacian energy LE, Laplacian-energy-like invariant LEL and Kirchhoff index Kf, are graph invariants defined in terms of Laplacian eigenvalues. These are, respectively, defined as LE(G) = ?n,i=1 |?i-2m/n|, LEL(G) = ?n-1 i=1 ??i and Kf (G) = n ?n-1,i=1 1/?i. A vertex-degree-based topological index referred to as degree deviation is defined as S(G) = ?n,i=1 |di- 2m/n|. Relations between Kf and LE, Kf and LEL, as well as Kf and S are obtained.

This paper deals with the problem of finding some upper bound estimates for the maximum modulus of a univariate complex polynomial on a disk under certain constraints on the zeros and on the functions involved. A variety of interesting results follow as special cases from our general results.

Introduction/Objective. Vocal folds are the most common primary site of laryngeal carcinoma. Advancement in diagnostic and therapeutic modalities have provided better prognosis for patients with early glottic carcinoma. We aimed to report the role of videolaryngostroboscopy (VLS) in early diagnosis of vocal fold carcinoma. Methods. Prospective controlled study included 300 dysphonic patients admitted to the tertiary medical center for microlaryngoscopy with biopsy. All patients underwent stroboscopic examination prior to biopsy. VLS findings were classified according to Hirano into four stages, with an adynamic vocal fold segment and absence of vocal fold vibration, suspected for vocal fold carcinoma at stage IV. Histopathological findings have been graded according to Ljubljana classification into simple hyperplasia, abnormal hyperplasia, atypical hyperplasia, and carcinoma in situ. Results. Analysis of VLS findings showed that 41.67% of patients (n = 125/300) had asymmetrical and irregular vocal fold vibration with a mucosal wave reduction (VLS stage III), while an adynamic vocal fold segment and absence of vocal fold vibration (VLS stage IV), suspected for vocal fold carcinoma, was noticed in 17.33% of patients (n = 52/300). Histopathology report showed that vocal fold carcinoma was verified in 5.6% of patients in VLS stage III (n = 7/125), while VLS stage IV carcinoma was detected in 26.92% of patients (n = 14/52). Adynamic segment or entire nonvibrating vocal fold finding predicts early glottic carcinoma with a sensitivity of 66.77%, specificity of 86.4%, and moderate diagnostic accuracy (AUC = 0.844). Conclusion. VLS plays an important role as a timely indicator for microlaryngoscopy with biopsy in diagnosis of vocal fold carcinoma.

In this work, the extraction by supercritical carbon dioxide of grapeseed oil from five red grape varieties was investigated. Apart from an indigenous variety Prokupac, as the domestic, and Merlot and Cabernet Sauvignon, as international grape varieties the most represented in the Republic of Serbia, Pinot Noir and Gamay were studied as well. Extraction conditions were: temperature of 50?C, 250 bar pressure, and 0.3 kg/h flow rate of CO2. It was shown that the extraction kinetics of international grape varieties, mutually similar differ significantly from the domestic one. The obtained oil yields were in the range of 8.3% w/w (Gamay) to 10.4% w/w (Pinot Noir) for the international varieties and 5.0% w/w for the domestic variety. The mathematical model ?Sovova? was applied to define transport parameters regulating the oil mass transfer inside the seed particles and determine the agreement between experimental and model curves. The interpretation of results took into account the differences of grade seed morphologies (outer surfaces and inner layers) which was investigated by SEM analysis.

In this paper, we obtain certain sharp estimates for the maximal modulus of a rational function with prescribed poles. The proofs of the obtained results are based on the new version of the Schwarz lemma for regular functions which was suggested by Osserman. The obtained results produce several inequalities for polynomials as well.

Introduction. The left main stem coronary artery (MSCA) thrombosis is a rare, but potentially lethal manifestation of the acute coronary syndrome. The standard approach in treating such patients is the primary percutaneous coronary intervention or coronary artery bypass graft surgery. In some cases, depending on the morphological appearance of the thrombus, findings and flow rates assessed on coronary angiography, clinical conditions, and cardiologist?s experiences, another method of treatment may be a conservative approach using the antithrombotic therapy. Case report. A 37 year-old male was admitted to the emergency room with symptoms of an acute myocardial infarction with an ST-elevation in diaphragmal localization. Using emergency coronary angiography we have visualized a thrombus at the ostial and proximal part of the left MSCA, with no complete obstruction of the blood flow. Initially, dual antithrombotic therapy (ticagrelor and acetylsalycilic acid) was applied, and in the further procedure , it was decided to introduce glycoprotein (GP) IIb/IIIa platelet receptor inhibitor (tirofiban) as an intracoronary bolus (0.3 ?g/kg) and later as continuous infusion (0.1 ?g /kg/min). Four days later, a control angiography and intravascular echocardiography were performed, and it was decided to continue the treatment using conservative therapy, without a pPCI procedure. The patient was discharged in a good condition with no signs of illness on the eighth day after hospital admission for home recovery, with planned frequent follow-ups in the future. Conclusion. In the case of non-obstructive thrombotic masses without significant atherosclerotic stenotic lesions, conservative treatment modality with the use of aggressive antithrombotic therapy may be considered.

Let G=(V,E), V={v1, v2,..., vn}, be a simple connected graph with n vertices, m edges and vertex degree sequence ? = d1?d2 ?...? dn = ? > 0, di = d(vi). General zeroth-order Randic index of G is defined as 0R?(G) = ?ni =1 d?i , where ? is an arbitrary real number. In this paper we establish relationships between 0R?(G) and 0R?-1(G) and obtain new bounds for 0R?(G). Also, we determine relationship between 0R?(G), 0R?(G) and 0R2?-?(G), where ? and ? are arbitrary real numbers. By the appropriate choice of parameters ? and ?, a number of old/new inequalities for different vertex-degree-based topological indices are obtained.