Heavy metals in commercial fish and seafood products and risk assessment in adult population in Bosnia and Herzegovina.

This work investigates the level of exposure to cadmium (Cd), mercury (Hg), and lead (Pb) via fish and seafood products in adult population in Bosnia and Herzegovina (BiH). Metals content was determined in seven commercial species of fish and seafood products widely available and consumed in BiH. Analysis of Cd and Pb was performed by GFAAS (Graphite furnace atomic absorption spectrometry), and analysis of Hg by FIAS AAS (flow injection cold vapour atomic absorption spectrometry) in accredited laboratory for food analysis. The health risk was determined by the estimated weekly intake, hazard index, target hazard quotients, and percent of tolerable weekly intake or percent of benchmark dose lower confidence limit. Concentration above the maximum residue level (MRL) set in the European Union was found in only one sample (Hg in mackerel). Cd content was generally high in squid, approaching the corresponding MRL in two samples. The hazard index was close to 1 in bluefin tuna and mackerel, mostly due to Hg content. These two fish species should be consumed in moderation, especially by pregnant women. While consumption of various fish and seafood on average is not of significant concern, health risk could not be ruled out for high consumers.

A finite element-based machine learning approach for modeling the mechanical behavior of the breast tissues under compression in real-time.

This work presents a data-driven method to simulate, in real-time, the biomechanical behavior of the breast tissues in some image-guided interventions such as biopsies or radiotherapy dose delivery as well as to speed up multimodal registration algorithms. Ten real breasts were used for this work. Their deformation due to the displacement of two compression plates was simulated off-line using the finite element (FE) method. Three machine learning models were trained with the data from those simulations. Then, they were used to predict in real-time the deformation of the breast tissues during the compression. The models were a decision tree and two tree-based ensemble methods (extremely randomized trees and random forest). Two different experimental setups were designed to validate and study the performance of these models under different conditions. The mean 3D Euclidean distance between nodes predicted by the models and those extracted from the FE simulations was calculated to assess the performance of the models in the validation set. The experiments proved that extremely randomized trees performed better than the other two models. The mean error committed by the three models in the prediction of the nodal displacements was under 2 mm, a threshold usually set for clinical applications. The time needed for breast compression prediction is sufficiently short to allow its use in real-time (<0.2 s).

Identification and determination butylmethoxydibenzoylmethane in the presence benzophenone-3 and ethylhexylmethoxycinnamate in suncare preparation.

The protection of sun radiation is a problem on global level for all living organisms on Earth. The need of people for the overexposure to the UV radiation led human population towards finding novel ways of protection of this kind of radiation, in form of cosmetic preparations applied on the skin. So far, the high values of protection factors of preparations and total block preparations with sun protection factor of 50+ were achieved. Physical and chemical filters which absorb radiation are constituents of these preparations. European Union has set regulations as which substances and in what amounts could be used as UV absorbers. American FDA (Food and Drug Administration) also gave its list of the most frequently used UV absorbers in the sunscreen products, as well as their declared concentrations. The most frequently used concentrations of UV filters in cosmetics is between 0.1% and 10%. Concentrations of UV filters in sunscreen products have to be monitored in order to ensure that they are not less from the declared levels, on which depends the efficacy and safety of the product. Butyl methoxydibenzoylmethane (BMDM) is used as a UV-A filter in suncare products. Optimized high performance liquid chromatography method for BMDM determination in the presence of other UV filters in suncare preparations is presented in this paper. Determination was performed on C(8) reversed phase using UV detection at 357 nm and isocratic mobile phase of acetonitrile and 0.5% phosphoric acid (70 : 30 v/v). Proposed method has limit of detection of 0.058 microg mL(-1), limit of quantification 0.193 microg mL(-1) and linearity correlation coefficient of 0.9989. Commercially available products were analysed using the proposed method. All analysed samples complied with EU directives limit of BMDM content to no more than 5%.

Quantification of the modifications in the dominant frequency of ventricular fibrillation under conditions of ischemia and reperfusion: an experimental study.

The characteristics of ventricular fibrillatory signals vary as a function of the time elapsed from the onset of arrhythmia and the maneuvers used to maintain coronary perfusion. The dominant frequency (FrD) of the power spectrum of ventricular fibrillation (VF) is known to decrease after interrupting coronary perfusion, though the corresponding recovery process upon reestablishing coronary flow has not been quantified to date. With the aim of investigating the recovery of the FrD during reperfusion after a brief ischemic period, 11 isolated and perfused rabbit heart preparations were used to analyze the signals obtained with three unipolar epicardial electrodes (E1-E3) and a bipolar electrode immersed in the thermostatized organ bath (E4), following the electrical induction of VF. Recordings were made under conditions of maintained coronary perfusion (5 min), upon interrupting perfusion (15 min), and after reperfusion (5 min). FrD was determined using Welch's method. The variations in FrD were quantified during both ischemia and reperfusion, based on an exponential model deltaFrD = A exp (-t/C). During ischemia deltaFrD is the difference between FrD and the minimum value, while t is the time elapsed from the interruption of coronary perfusion. During reperfusion deltaFrD is the difference between the maximum value and FrD, while t is the time elapsed from the restoration of perfusion. A is one of the constants of the model, and C is the time constant. FrD exhibited respective initial values of 16.20 +/- 1.67, 16.03 +/- 1.38, and 16.03 +/- 1.80 Hz in the epicardial leads, and 15.09 +/- 1.07 Hz in the bipolar lead within the bath. No significant variations were observed during maintained coronary perfusion. The fit of the FrD variations to the model during ischemia and reperfusion proved significant in nine experiments. The mean time constants C obtained on fitting to the model during ischemia were as follows: E1 = 294.4 +/- 75.6, E2 = 225.7 +/- 48.5, E3 = 327.4 +/- 79.7, and E4 = 298.7 +/- 43.9 seconds. The mean values of C obtained during reperfusion, and the significance of the differences with respect to the ischemic period were: E1 = 57.5 +/- 8.4 (P < 0.01), E2 = 64.5 +/- 11.2 (P < 0.01), E3 = 80.7 +/- 13.3 (P < 0.01), and E4 = 74.9 +/- 13.6 (P < 0.0001). The time course variations of the FrD of the VF power spectrum fit an exponential model during ischemia and reperfusion. The time constants of the model during reperfusion after a brief ischemic period are significantly shorter than those obtained during ischemia.

Application of adaptive signal processing for determining the limits of P and T waves in an ECG.

A new algorithm for the determination of the limits of P and T waves is proposed, and its foundations are mathematically analyzed. The algorithm performs an adaptive filtering so that the searched point corresponds to a minimum. Crucial properties of its performance are discussed, i.e., immunity to base line drifts and full adaptation to any cardiological criteria. A series of tests are made involving real registers with different morphologies for P and T-waves.

[The automatic, beat-to-beat determination of the QT interval and analysis of its spontaneous variability under basal conditions]. / Determinación automática, latido a latido, del intervalo QT y análisis de su variabilidad espontánea en condiciones basales.

OBJECTIVES: An analysis is made of the automatic beat-by-beat measurement of QT and other intervals related to ventricular repolarization. The variability pattern of these intervals is investigated in normal subjects at rest, along with their relation to RR cycle variability. MATERIAL AND METHODS: The electrocardiographic signals (LII) from 11 normal subjects (mean age 31 +/- 10 years) were recorded over 5 min and processed by applying specific algorithms to determine beat-by-beat the RR, QT, RT, QTm and RTm intervals (Tm = peak of T wave). An analysis was made of the variability of these intervals in the time (standard deviation, variation coefficient, difference between maximum and minimum values) and frequency domains (spectral analysis applying the Fourier transform). RESULTS: The differences between the automatic measurements and those performed by two observers (n = 110) were respectively -1.3 +/- 6.4 and -3.7 +/- 6.5 ms for QT, - 1.0 +/- 1.4 and -1.0 +/- 2.3 ms for QTm, -0.3 +/- 1.4 and -0.2 +/- 1.8 ms for RTm, and 0.7 +/- 6.5 and -2.8 +/- 10.3 ms for RT. The QT and RT intervals exhibited greater variability (SD = 6 +/- 1 ms) than QTm and RTm (SD = 3 +/- 1 ms, p < 0.0001). These differences persisted on comparing the corresponding variation coefficients. The differences between the maximum and minimum measurements were 45 +/- 24 ms for QT and RT, the values being significantly less in the case of QTm (21 +/- 26 ms, p < 0.05) and RTm (20 +/- 27 ms, p < 0.05). In the frequency domain, the high- (HF) and low-frequency (LF) band energies were low in the series formed by the ventricular repolarization intervals, and the LF band normalized amplitude was significantly lower than in the RR series. There were no significant differences in the frequencies of the maximum values of the LF and HF bands of the RR series with respect to the QT series. The correlations between the RR intervals and the subsequent repolarization intervals obtained in each subject were not significant in 7 of the 11 subjects studied. CONCLUSIONS: The automatic beat-by-beat determination of the ventricular repolarization intervals is precise, particularly when considering the intervals defined by the T wave peak. Repolarization variability during the sinus rhythm at rest is small, and is not linearly related to modifications of the previous RR interval. Neurovegetative and humoral influences are postulated to explain QT variations. The neurovegetative and humoral influences that regulate cardiac cycle and ventricular repolarization variability at rest, are found to be quantitatively different.

[Spectrophotometric determination of atropine-sulfate in eyedrops using bromthymol blue]. / Spektrofotometrijsko odredivanje atropin-sulfata u kapima za oci upotrebom bromtimolplavog.

Content of atropine in eye drops of atropine sulfate were determined colorimetrically and spectrophotometricaly using methods of ion pairs with bromtimolblue. The described method is more convenient for routine analysis then non aqueous titration described in various Pharmacopeas.

[Identification of oxymetholone metabolites in the urine using gas chromatography-mass spectrometry]. / Identifikacija metabolita oksimetolona u urinu metodom gasna hromatografija-spektrometrija masa.

Metabolite of 17-methyl-17-hydroxy-2-(hydroxymethylen)-androstan-3-one (oxymetholane) in urine after a single oral administration was monitored by gas chromatography+mass spectrometry. During the investigation prepared TMS-ethers and TMS-enol-ethers of conjugated steroid fraction two new metabolites of oxymetholone have been identified: tetrahydrooxymetholone and tetrahydro-6-hydroxy-oxymetholone.

[Polycyclic aromatic hydrocarbons in the atmosphere in the town of Zenica]. / Policiklicki aromatski ugljikovodici u atmosferi grada Zenice.

The content of some polycyclic aromatic hydrocarbons in extracts of particulate matter collected in the city of Zenica in December 1987 was analysed. In addition to the presence of proven carcinogens like benzo(a)pyrene, benzo(a)anthracene, chryzene and dibenzo(a,h)anthracene, the contents of naphthalene, fluorene, fenanthrene, anthracene, fluoranthene and pyrene were also determined. Those substances were rightly assumed to be precursors of genotoxic products in reactions with atmospheric nitrogen oxides. The determined average concentration of benzo(a)pyrene was higher than those found in other places in Yugoslavia where similar studies were conducted. At the same time, the measured benzo(a)pyrene concentration exceeded the guidelines for inhabited places according to the standards of the Federal Republic Germany and the Netherlands. The observed high variations in naphthalene concentration of as much as two orders of magnitude in two days were likely due to unsolved technological problems.