HRVATSKI ŠPORTSKOMEDICINSKI VJESNIK – 30 GODINA IZLAŽENJA

HRVATSKI ŠPORTSKOMEDICINSKI VJESNIK – 30 GODINA IZLAŽENJ

HRVATSKI ŠPORTSKOMEDICINSKI VJESNIK – 30 GODINA IZLAŽENJA

HRVATSKI ŠPORTSKOMEDICINSKI VJESNIK – 30 GODINA IZLAŽENJ

Bis-Pyrene Photo-Switch Open- and Closed-Form Differently Bind to ds-DNA, ds-RNA and Serum Albumin and Reveal Light-Induced Bioactivity

Newly designed and synthesized diarylethene (DAE) derivatives with aliphatic amine sidearms and one with two pyrenes, revealed excellent photo-switching property of central DAE core in MeOH and water. The only exception was bis-pyrene analogue, its DAE core very readily photochemically closed, but reversible opening completely hampered by aromatic stacking interaction of pyrene(s) with cyclic DAE. In this process, pyrene fluorescence showed to be a reliable monitoring method, an open form characterized by strong emission at 480 nm (typical for pyrene-aggregate), while closed form emitted weakly at 400 nm (typical for pyrene-DAE quenching). Only open DAE-bis-pyrene form interacted measurably with ds-DNA/RNA by flexible insertion in polynucleotide grooves, while self-stacked closed form did not bind to DNA/RNA. For the same steric reasons, flexible open DAE-bis-pyrene form was bound to at least three different binding sites at bovine serum albumin (BSA), while rigid, self-stacked closed form interacted dominantly with only one BSA site. Preliminary screening of antiproliferative activity against human lung carcinoma cell line A549 revealed that all DAE-derivatives are non-toxic. However, bis-pyrene analogue efficiently entered cells and located in the cytoplasm, whereby irradiation by light (315–400 nm) resulted in a strong, photo-induced cytotoxic effect, typical for pyrene-related singlet oxygen species production

Photochemical Reactivity of Naphthol-Naphthalimide Conjugates and Their Biological Activity

Quinone methide precursors 1a–e, with different alkyl linkers between the naphthol and the naphthalimide chromophore, were synthesized. Their photophysical properties and photochemical reactivity were investigated and connected with biological activity. Upon excitation of the naphthol, Förster resonance energy transfer (FRET) to the naphthalimide takes place and the quantum yields of fluorescence are low (ΦF ≈ 10−2). Due to FRET, photodehydration of naphthols to QMs takes place inefficiently (ΦR ≈ 10−5). However, the formation of QMs can also be initiated upon excitation of naphthalimide, the lower energy chromophore, in a process that involves photoinduced electron transfer (PET) from the naphthol to the naphthalimide. Fluorescence titrations revealed that 1a and 1e form complexes with ct-DNA with moderate association constants Ka ≈ 105–106 M−1, as well as with bovine serum albumin (BSA) Ka ≈ 105 M−1 (1:1 complex). The irradiation of the complex 1e@BSA resulted in the alkylation of the protein, probably via QM. The antiproliferative activity of 1a–e against two human cancer cell lines (H460 and MCF 7) was investigated with the cells kept in the dark or irradiated at 350 nm, whereupon cytotoxicity increased, particularly for 1e (>100 times). Although the enhancement of this activity upon UV irradiation has no imminent therapeutic application, the results presented have importance in the rational design of new generations of anticancer phototherapeutics that absorb visible light

The 1,3-diaryltriazenido(p-cymene)ruthenium(II) complexes with a high in vitro anticancer activity ☆

1,3-Diaryltriazenes (1) were let to react with [RuCl 2 (p-cymene)] 2 in the presence of trimethylamine to give neutral 1,3-diaryltriazenido(p-cymene)ruthenium(II) complexes, [RuCl(p-cymene)(ArNNNAr)] (2). The molecular composition of the products 2 was confirmed by NMR spectroscopy and mass spectrometry. The structures of the selected complexes were confirmed by a single crystal X-ray analysis. All triazenido-ruthenium complexes were highly cytotoxic against human cervical carcinoma HeLa cells with IC 50 below 6 μM, as determined by a spectrophotometric MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide) method. The most active was [RuCl(p-cymene)(ArNNNAr)] (Ar = 4-Cl-3-(CF 3 )-C 6 H 3 ) (2g) with IC 50 of 0.103 ± 0.006 μM. In comparison with the data for the non-coordinated triazenes 1, the triazenido-ruthenium complexes 2 exhibited up to 560-times higher activity. Three selected complexes were highly cytotoxic also against several tumor cell lines: laryngeal carcinoma HEp-2 cells and their drug-resistant HEp-2 subline (7 T), colorectal carcinoma HCT-116 cells, lung adenocarcinoma H460 cells, and mammary carcinoma MDA-MB-435 cells. The compounds 2g and [RuCl(p-cymene)(ArNNNAr)] (Ar = 4-I-C 6 H 4 ) (2j) were similarly cytotoxic against parental and drug-resistant cells. Time and dose dependent accumulation of the cells in the S phase of the cell cycle was induced by the compound 2g, triggering apoptosis. Our preliminary results indicate triazenido-ruthenium complexes as promising anticancer drug candidates

Nanokristalliner Sensor zur Erfassung von lokalen Induktionswerten in laminierten Magnetkernen

Abweichender Titel nach Übersetzung der Verfasserin/des VerfassersMagnetic cores of transformers, shunt reactors, electric motors, generators, rotating machines etc. exhibit very complex flux distributions. As it is well known, the variations of the local inductions, but also fluxes in normal and transverse direction tend to influence the core losses and the magnetostriction in a very significant way. For improvements and optimizations of the magnetic cores, aiming lower losses and audible noise, the evaluations of the local induction values are an inevitable task. Furthermore, the correct detection of the induction out of the rolling direction for assessment of the rotational magnetization is of a great significance for industry, in particular for transformer core manufacturers. Established methods of local induction measurement, such as drilling holes in the laminations and inserting pick up coils, are extremely laborious as well as destructive for the cores. In the current work, a novel tangential induction sensor was manufactured and is presented. With this sensor, non-destructive measurements, not only on the surface, but also in core interior should be possible. Contrary to the traditional tangential H-sensors, the current sensor possess a very thin nanocrystalline ribbon as a 'dummy' core. Around the ribbon a thin wire ( - 50 µm) is wounded. Placed in a location of a laminated core with unknown induction B, the sensor is magnetized with Bs. In most likely case, both inductions deviate from each other, on one hand side due to the different permeabilities and on the other due to existing demagnetizing field. However, using a priori calibrated function B(Bs), the unknown induction can be evaluated. A very important part of the concept of the tangential induction sensor is the calibration of the sensor. The sensor can be calibrated in an Epstein frame, or in a region of laminated core of well known induction. However, in the current work, measurements not only in the rolling direction, but also for two other important directions were performed for assessment of rotational magnetization. Therefore, an individual sensor was not sufficient. For that aim, in the current work, a set of sensors was used placed on a thin kapton foil, attached to the surface of a hexagonal grain oriented sample. The sensors were placed in rolling direction, in transverse direction (TD) and in 30° angle to the RD. The calibration was performed by means of a Vienna Rotational Single Sheet Tester. As shown in a previous work, the resolution of the nanocrystalline sensors depend strongly on the used geometry. For that purpose, three sensor sets with different lengths and widths of the nanocrystalline ribbons are prepared, tested and compared with each other. In an individual set, all three sensors are of the same dimensions. The longest set of sensors tend to be not useful at all, even for low induction values B. Due to the high length of the sensor, the demagnetizing effect tend to be very weak, and it reaches saturation for B > 0.6 T, due to the extremely high initial permeability values of the nanocrystalline material (µr - 100000) . The sensor set of middle length exhibits excellent resolution for low induction values B, but is not effective for a magnetisation above 1.1 T due to saturation effects. On the other side, the widest and shortest set of sensors tend to exhibit the best results, good resolution for high B, and sufficient resolution for low B. The presented sets of sensors were tested in a 3-phase, 3-limb transformer core. The sensor shows good results of the measured induction for the rolling direction. However, it was not very effective for the transverse direction, mainly due to saturation effects. For the interpretation of the achieved results, numerical simulations are presented. They are performed by a novel MACC (Multi-directionally non-linear magnetic equivalent circuit calculation) method, developed by our group.3

Jesuit talars as a source of inspiration for the manufacture of formal academical gown for the University of Zagreb

Jesuit talars were used as a source of Inspiration for the Manufacture of Formal Academical Gown for the University of Zagreb

A 3D Vizualization and Simulation of the Individual Human Jaw

A new biomechanical three-dimensional (3D) model for the human mandible based on computer-generated virtual model is proposed. Using maps obtained from the special kinds of photos of the face of the real subject, it is possible to attribute personality to the virtual character, while computer animation offers movements and characteristics within the confines of space and time of the virtual world. A simple twodimensional model of the jaw cannot explain the biomechanics, where the muscular forces through occlusion and condylar surfaces are in the state of 3D equilibrium. In the model all forces are resolved into components according to a selected coordinate system. The muscular forces act on the jaw, along with the necessary force level for chewing as some kind of mandible balance, preventing dislocation and loading of nonarticular tissues. In the work is used new approach to computer-generated animation of virtual 3D characters (called »Body SABA«), using in one object package of minimal costs and easy for operation