Multidisciplinary investigations of a karst reservoir for managed aquifer recharge applications on the island of Vis (Croatia)

Managed aquifer recharge (MAR) refers to a suite of methods by which excess surface water or non-conventional water is stored underground for subsequent recovery or environmental purposes. MAR solutions have been largely used in unconsolidated aquifers, while their application in karst aquifers is rare. This research presents the first results of a MAR viability study on the island of Vis, a small karstic island in the Adriatic Sea. Favorable geological and hydrogeological conditions enable the formation of karst aquifers, making the island autonomous in terms of water supply. The island's main aquifer, exploited in the Korita well field, is protected from seawater intrusion by several hydrogeological barriers. However, climate change and high seasonal pressures related to tourism pose a threat to the future availability of freshwater. Multidisciplinary field and laboratory investigations were carried out to detail the geological and hydrogeological setting of the island and its groundwater resource. Field analyses consisted of groundwater monitoring and sampling, geophysical investigations (i.e., electrical resistivity tomography), and structural measurements. Laboratory analyses included measurements of principal cations and anions and tritium activity. Despite low precipitation during the observation period (September 2019 - December 2020), the groundwater resource at the Korita site showed stable trends of physico-chemical parameters with a good storage potential and a long-term reserve. Geophysical investigations evidenced a relatively homogeneous sequence of the rock mass at a larger scale, while structural analyses indicated the occurrence of E-W karstified and open fractures that could represent a preferential flow path in the carbonate aquifer. A MAR solution for the Vis island was proposed combining an infiltration pond scheme with the direct injection of the accumulated waters into the aquifer using available wells. The potential water source could be represented by the runoff collected in an old artificial channel and the associated pond system in Korita

Measuring TFP: Growth Accounting for the Real Sector of the Economy in the Republic of Srpska

ABSTRACT: This paper shows the results of research on contribution of Total Factor Productivity to the growth of the real sector in the Republic of Srpska. Total factor productivity is analytical tool which  enables researchers to determine the contribution of supply-side production factors to economic growth. For the Republic of Srpska, which has a transition economy, it is a very difficult to construct a production function with stable and unbiased parameters, mostly because the lack of sufficiently long and dependable data series. Considering  this, growth accounting enables us to identify the basic sources and direction of influences. The calculations that have been made enable researchers to identifies the Total Factor Productivity as the main driving force of economic growth for the real sector in the Republic of Srpska</em

Correlation of structural defects in the ascending aortic wall to ultrasound parameters: benefits for decision-making process in aortic valve surgery

Abstract Background Histopathological changes in the ascending aorta wall in patients with severe tricuspid aortic valve (TAV) stenosis were graded and correlated to echocardiographic parameters. Objective was to associate threshold echocardiographic values with structural defects in the ascending aorta providing a tool to improve decision-making process in cases when simultaneous aortic valve replacement (AVR) and ascending aorta replacement is considered. Methods Biopsies from 108 TAV stenosis patients subjected to AVR were graded into three grades according to severity of aortic wall changes. Echocardiographic parameters obtained preoperatively and correlated to grade, age, gender and risk factors, were diameters of ventriculo-aortic junction (AA), sinus Valsalva (SV), sinotubular junction (STJ), the largest diameter of the visualized ascending aorta (AscA) as well as indexes: sinus Valsalva (SVI), sinotubular junction (STJI), AscA/AA and STJ/AA. Results Two echocardiographic parameters portrayed grades with statistical significance: STJ (F = 5.417; p = 0.006 (p  3.3 cm, while Grade 3 is identified in patients with values of AscA > 3.5 cm, STJ > 2.9 cm and STJI > 1. Conclusions Hemodynamic stress induced by TAV stenosis leads to elastic lamellae disruption in the aortic wall. Those changes could be graded and correlated with echocardiographic parameters of the aortic root and ascending aorta, providing a tool for decision to replace ascending aorta concomitantly with AVR

Natural history of the aortic wall changes in adults with the degenerative tricuspid aortic valve stenosis: The morphometric proofs and implications for echocardiography

Background/Aim. So far, no study has been focused exclusively on the tricuspid aortic valve stenosis (TAV) in the aorta without severe dilatation and none has aimed at correlating the high mycroscopy findings with the echocardiographic parameters. This research was conducted on the postulate that detecting the histopathological changes of different severity in the aortic wall could tailor decision about an aortic surgery. The aim of this study was to grade the histopathological changes in the wall of the nonseverely dilated ascending aorta in patients with the severe, calcific TAV stenosis and to correlate them with the echocardiographic parameters in order to analyze when the ascending aorta should be replaced simultaneously with the aortic valve replacement (AVR). Methods. The samples from 37 patients subjected to the AVR and the samples from the control group were analyzed morphologically. The echocardiographic parameters obtained in the TAV stenosis patients were preoperatively correlated with the morphological data, age and gender, diameters of the ventriculo-aortic junction (AA), the sinus Valsalvae (SV) and sinotubular junction (STJ), the largest diameter of the visualized ascending aorta (AscA), the sinus Valsalvae index (SVI) and AscA/AA index. Results. We confirmed morphometrically the exact region of the hemodynamic stress influence with the mathematical distinction in comparison to the controls. In this region, the gradual elastic lamellae disruption was proved by a statistically significant difference through the 3 grades. The elastic skeleton alterations were potentiated with aging and in females. The morphometric parameters of the ascending aorta wall statistically significantly correlated with the echocardiographic parameters: AA, SV, AscA and SVI. The echocardiographic parameters tended to be higher in the most severe grade 3, in the patients younger than 65 years of age. The AscAof more than 4.5 cm was associated with the irreversible morphological defects in these patients. Conclusion. The hemodynamic stress induced by the TAV stenosis leads to the ascending aorta elastic lamellae disruption that could be histopathologically graded and correlated with the echocardiographic parameters of the ascending aorta providing a potential tool for decision-making process in cases when the ascending aorta replacement is considered simultaneously with the AVR. [Projects of the Serbian Ministry of Education, Science and Technological Development, Grant no. 175005, Grant no. 175061, Grant no. III45005, Grant no. III41002, Grant no. III41022

Structural features of arterial grafts important for surgical myocardial revascularization: Part II - Histology of the radial, inferior epigastric, and right gastroepiploic arteries

[Projekat Ministarstva nauke Republike Srbije, br. 175005, 175061, III41002, III45005 i 41022

Structural features of arterial grafts important for surgical myocardial revascularization: Part I - Histology of the internal thoracic artery

[Projekat Ministarstva nauke Republike Srbije, br. 175005, 175061, III41002, III45005 i 41022

Fullerenol/doxorubicin nanocomposite mitigates acute oxidative stress and modulates apoptosis in myocardial tissue

Fullerenol (C-60(OH)(24)) is present in aqueous solutions in the form of polyanion nanoparticles with particles size distribution within the range from 15 to 42 nm. In this research it is assumed that these features could enable fullerenol nanoparticles (FNPs) to bind positively charged molecules like doxorubicin (DOX) and serve as drug carriers. Considering this, fullerenol/doxorubicin nanocomposite (FNP/DOX) is formed and characterized by ultra-performance liquid chromatography tandem mass spectrometry, dynamic light scattering, atomic force microscopy and transmission electron microscopy. Measurements have shown that DOX did not significantly affect particle size (23 nm). It is also assumed that FNP/DOX could reduce the acute cardiotoxic effects of DOX in vivo (Wistar rats treated i.p.). In this study, quantitative real time polymerase chain reaction results have shown that treatment with DOX alone caused significant increase in mRNA levels of catalase (p LT 0.05) enzyme indicating the presence of oxidative stress. This effect is significantly reduced by the treatment with FNP/DOX (p LT 0.05). Furthermore, mRNA levels of antiapoptotic enzyme (Bcl-2) are significantly increased (p LT 0.05) in all treated groups, particularly where FNP/DOX was applied, suggesting cell resistance to apoptosis. Moreover, ultrastructural analysis has shown the absence of myelin figures within the mitochondria in the heart tissue with FNP/DOX treatment, indicating reduction of oxidative stress. Hence, our results have implied that FNP/DOX is generally less harmful to the heart compared to DOX

Effects of a fullerenol/doxorubicin nanocomposite on the heart tissue of healthy rats

40th Congress of the Federation-of-European-Biochemical-Societies (FEBS) - The Biochemical Basis of Life, Jul 04-09, 2015, Berlin, German

Effects of a fullerenol/doxorubicin nanocomposite on the heart tissue of healthy rats

40th Congress of the Federation-of-European-Biochemical-Societies (FEBS) - The Biochemical Basis of Life, Jul 04-09, 2015, Berlin, German