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Three Schiff base Cu(II) complexes, (N,N’-bis(acetylacetone)propylenediimine) copper(II) complex, [Cu(acac2pn)] (1), (N,N'-bis-(benzoylacetone) propylenediimine)copper(II) complex, [Cu(phacac2pn)] (2) and (N,N’-bis- -(trifluoroacetylacetone)propylenediimine)copper(II) complex, [Cu(tfacac2pn)] (3), were used to investigate the interactions with calf thymus DNA (ct-DNA) and bovine serum albumin (BSA) using the electronic absorption and spectroscopic fluorescence methods. UV–Vis absorption studies showed that studied complexes interact with DNA molecule and exhibit moderate binding affinity. Fluorescence studies of complexes 1–3 also showed a possibility for DNA intercalation as well as a relatively high binding ability toward BSA. Among the tested complexes, the highest affinity for DNA and BSA molecules was shown by complex 1. Cytotoxic analyses, performed on human colorectal carcinoma HCT-116 and healthy lung fibroblast MRC-5 cell lines, showed that complex 2 exhibited activity on both cell lines, while complexes 1 and 3 did not show any activity.

This retrospective study provides an insight into the levels of radiation exposure of six nuclear medicine (NM) staff (four technologists and two nurses) performing routine diagnostic 18F-fluorodeoxyglucose (18F-FDG) positron emission tomography-computed tomography (PET/CT) at the University Clinical Centre of the Republic of Srpska, Department of Nuclear Medicine and Thyroid Disorders, Banja Luka, Bosnia and Herzegovina. Data analysis included monthly staff exposure measured with personal thermoluminescent dosimeters (TLD) between June and December 2018, quantified in terms of normalised dose for the whole body [Hp(10)] and dominant hand [Hp(0.07)] and their comparison between each staff member and between the two groups (technologists and nurses). The study goal was to establish how our Department compared with reports from other PET/CT centres worldwide in terms of annual number of procedures and exposure limits and whether there could be room for further improvements in radiation protection. The number of procedures rose considerably from 208 in 2016 to 876 in 2019 and was 423 in the observed seven-month period. Mean individual whole-body exposure dose per GBq of injected 18F-FDG activity, [Hp(10)/A] was 18.55 μSv/GBq for the four technologists and 15.61 μSv/GBq for the two nurses. Mean dominant-hand exposure dose per GBq of injected 18F-FDG activity [Hp(0.07)/A] was 16.99 μSv/GBq and 25.44 μSv/GBq for the two groups, respectively. The average annual cumulative dose for all staff was (1.06±0.29) mSv for Hp(10) and (1.15±0.32) mSv for Hp(0.07). These results are comparable with those of similar studies. Staff doses were well below the annual limits. Nurses received slightly higher extremity doses than technologists. In view of the increasing trends in the number of PET/CT procedures, dose monitoring should be continued to identify exposure hotspots and maintain doses as low as possible.

In this paper we reported the kinetics of the disproportionation reaction of iodous acid (HOIO) in aqueous sulfuric acid solutions (0.18 mol/dm3) studied by spectrophotometrical measurements of the absorbance at suitable wavelength. The changes of the absorbance were caused because the absorbing I2 molecule species were generated during the reaction. The disproportionation rate constants are calculated at the temperature range between 285 and 303 K with average values: k285 = (0.90 ± 0.08) dm3mol-1s-1, k291 = (1.10 ± 0.10) dm3mol-1s-1, k298 = (1.30 ± 0.07) dm3mol-1s-1 and k303 = (1.50 ± 0.10) dm3mol-1s-1, respectively. The corresponding activation energy was determined, for the chosen temperature interval, by a graphical method. In addition, obtained value of activation energy is Ea = 38 ± 5 kJ/mol. The negative value of Gibbs energy change and other thermodynamical parameters show that is the disproportionation reaction thermodynamically feasible.

Introduction: The difficulties during airway management can lead to iatrogenic tracheal injury. Conservative and surgical treatments are possible treatments. We present the case of a patient with iatrogenic tracheal injury treated conservatively. Case report: 55 years old female patient was transferred to our intensive care unit from a regional health center. Edema compromised airway as a consequence of anaphylactic shock was difficult to establish. Three days after tracheal injury the patient was transported to our institution. At admission, patient was under sedation with trachea intubated with tracheal tube and mechanically ventilated. Physical examination revealed subcutaneous emphysema in the region of head, neck, chest and upper extremities. Multi slice computerized tomography and tracheo-bronchoscopic exploration revealed longitudinal gap localized at posterior wall of the trachea, approximately 5 cm long, with distal end 1.5 cm above the tracheal carina. Tracheal split was completely closed after 13 days. The patient was discharged from the hospital after 22 days. Conclusion: Iatrogenic tracheal injury can be treated successfully using conservative measures after appropriate patient assessment and treatment planning. .

The present study was conducted in order to evaluate efficiency of a personal body cooling system based on passive evaporative technologies and its effects on test subjects psycho-physiological suitability during exertional heat stress in hot environment. Performed results are based on conducted tests in climatic chamber in the Military Medical Academy Institute of Hygiene in Belgrade. Ten male test subjects were subjected to exertional heat stress test consisted of walking on motorized treadmill at a speed of 5 km/h in hot environment. Tests were performed with and without cooling system. As a physiological strain indicator the following parameters have been determined: mean skin temperature, tympanic temperature, heart rate and sweat rate. Results confirmed that cooling vest worn over the clothes was able to attenuate the physiological strain levels during exercise, when compared to identical exposure without the cooling system.

In this work, the matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectra of two cationic complexes, i.e., [PdCl(dien)]Cl and [Ru(en)2Cl2]Cl, acquired under different conditions were analyzed. The spectra were recorded with three matrices with or without trifluoroacetic acid (TFA), i.e., two traditional matrices, i.e., 2,5-dihydroxybenzoic acid and α-cyano-hydroxycinnamic acid, and one flavonoid, quercetin. The spectra acquired with quercetin appeared to be the simplest, whereas in the spectra obtained with other matrices, peaks arising either from the addition of matrix molecules or from the fragmentation products were detectable. Addition of TFA did not complicate the spectra of the Pd(II) and Ru(III) complexes when the traditional matrices were used. On the other hand, the spectra of Pd complex were simpler, whereas the addition of TFA in the case of the Ru complex resulted in a higher number of peaks, some of which could not be identified. Taken together, the results of this study once more emphasize the differences arising in the MALDI-TOF mass spectra of transition metal complexes in dependence on the applied matrix.

Two new complexes of Pd(II), [Pd(L1)Cl]Cl (Pd1) and [Pd(L2)Cl]Cl (Pd2), (where L1 = N2,N6-bis(5-methylthiazol-2-yl)pyridine-2,6-dicarboxamide and L2 = N2,N6-di(benzo[d]thiazol-2-yl)pyridine-2.6-dicarboxamide) were synthesized. Characterization of the complexes was performed using elemental analysis, IR, 1H NMR spectroscopy and MALDI-TOF mass spectrometry. The nucleophilic substitution reactions of complexes with L -Methionine (L -Met), L -Cysteine (L -Cys) and guanosine-5′-monophosphate (5′-GMP) were studied by stopped-flow method at physiological conditions (pH = 7.2 and 37 °C). Complex Pd1 was more reactive than Pd2 in all studied reactions, while the order of reactivity of the selected ligands was: L -Met > L -Cys > 5′-GMP. The interaction of complexes with calf thymus-DNA (CT-DNA) was studied by Uv–Vis absorption and fluorescence emission spectroscopy. Competitive binding studies with intercalative agent ethidium bromide (EB) and minor groove binder Hoechst 33258 were performed as well. Both complexes interacted with DNA through intercalation and minor groove binding, where the latter was preferred. Additionally, the interaction of Pd1 and Pd2 complexes with human serum albumin (HSA) was studied employing fluorescence quenching spectroscopy. The results indicate a moderate binding affinity of complexes, with slightly stronger binding of the Pd1. Fluorescence competition experiments with site-markers (eosin Y and ibuprofen) for HSA were used to locate the binding site of Pd1 to the HSA. Additionally, the interaction with DNA and HSA was studied by molecular docking and the revealed results were in good agreement with the experimentally obtained ones. Pd1 complex exhibited cytotoxicity toward human (HCT116) and mouse cell lines (CT26) of colorectal cancer, mouse (4T1) and human (MDA-MB468) breast cancer lines and non-cancerous mouse mesenchymal stem cells (mMSC). In addition, Pd1 complex demonstrated significant selectivity towards cancer cells over non-cancerous mMSC, indicating a high potential to eliminate malignant cells without affecting normal cells. It induced apoptosis in CT26 cells, effectively arrested the cell cycle in the S phase, and selectively down-regulated cyclin D and cyclin E. Moreover, it can alter the expression of cell cycle regulators by increasing p21 and decreasing p-AKT. These findings confirm its ability to disrupt key tumor cell survival signals and suggest that the Pd1 complex is a potent candidate for effective cancer treatment. [ABSTRACT FROM AUTHOR]

This aimed to develop a comprehensive theoretical protocol for examining substitution reaction processes. The researchers used a theoretical quantum-mechanical protocol based on the QM-ORSA approach, which estimates the kinetic parameters of thermodynamically favourable reaction pathways. This theoretical protocol was validated by experimentally investigating substitution mechanisms in two previously synthesised Pd(II) complexes: chlorido-[(3-(1-(2-hydroxypropylamino)ethylidene)chroman-2,4-dione)]palladium(II) (C1) and chlorido-[(3-(1-(2-mercaptoethylamino)-ethylidene)-chroman-2,4dione)]palladium(II) (C2), along with biologically relevant nucleophiles, namely L -cysteine (L -Cys), L -methionine (L -Met), and guanosine-5′-monophosphate (5′-GMP). Reactions were investigated under pseudo-first-order conditions, monitoring nucleophile concentration and temperature changes using stopped-flow UV-vis spectrophotometry. All reactions were conducted under physiological conditions (pH = 7.2) at 37 °C. The reactivity of the studied nucleophiles follows the order: L -Cys > L -Met > 5′-GMP, and the reaction mechanism is associative based on the activation parameters. The experimental and theoretical data showed that C2 is more reactive than C1, confirming that the complexes' structural and electronic properties greatly affect their reactivity with selected nucleophiles. The study's findings have confirmed that the primary interaction occurs with the acid–base species L -Cys, mostly through the involvement of the partially negative sulfur atom (87.2%). On the other hand, C2 has a higher propensity for reacting with L -Cys−, primarily through the partially negative oxygen atom (92.6%). The implementation of this theoretical framework will significantly restrict the utilization of chemical substances, hence facilitating cost reduction and environmental protection. [ABSTRACT FROM AUTHOR]

The kinetics of the substitution reactions between bifunctional Au(III) complexes, [AuCl2(bipy)]+, [AuCl2(dach)]+ and [AuCl2(en)]+ (bipy = 2,2″-bipyridine, dach = (1 R,2R)-1,2-diaminocyclohexane, en = ethylenediamine), with biologically relevant ligands such as glutathione (GSH), L-methionine (L-Met) and L-cysteine (L-Cys) is determined. All kinetic studies are performed in 25 mM Hepes buffer (pH = 7.2) in the presence of NaCl (25 mM) to prevent hydrolysis of the complexes. The reactions were followed under pseudo-first-order conditions using stopped-flow UV–Vis spectrophotometry at determined working wavelengths at three different temperatures (288.2, 298.1, and 309.8 K). DFT theoretical approach was applied to calculate thermodynamic and kinetic parameters that determined an operative mechanism of substitution reactions for all complexes and L-Cys as a selected model substituent. The obtained kinetic data showed that all complexes have similar reactivity; [AuCl2(bipy)]+ is the most reactive while [AuCl2(en)]+ is the least reactive. The second step of the substitution reaction is much faster than the first. The reactivity of the studied nucleophiles decreases in order L-Met > L-Cys > GSH. According to the values of the activation parameters determined experimentally and theoretically, all substitutions follow an associative model. [ABSTRACT FROM AUTHOR]

The pioneer in clarification of the substitution reactions between platinum(II), palladium(II) and gold(III) complexes with biomolecules such as guanosine-5'-monophosphate (5'-GMP), glutathione (GSH) and L-methionine (L-Met) was Professor Dr. Živadin D. Bugarčić and his research group. In this minireview we highlight the important results of his research in the field of studying mechanisms of the substitution reactions of various transition metal complexes with square-planar geometry. Knowledge of the kinetic coordination chemistry of these transition metal ions helps to clarify the mechanism of action of metallodrugs for development of complexes with potent antitumor activity. The results are presented comparatively to aid in the future development of novel antitumor agents with unique mechanisms of action. [ABSTRACT FROM AUTHOR]