Short ingestion tests as alternative proposal for conventional range finding assays with Thamnocephalus platyurus and Brachionus calyciflorus

The goal of this study was to evaluate whether short 1 h sublethal assays may predict the results of 24 h lethality assays with rotifers Brachionus calyciflorus and anostracan crustaceans Thamnocephalus platyurus . The test bionts were hatched from cysts. Inhibition of ingestion was observed after 15 min of incubation of rotifers and crustaceans with the suspension of carmine and latex beads, respectively. Nine compounds with different modes of action were used as toxicants zinc ions, sodium dodecyl sulphate, p-nitrophenol, 3, 5-dichlorophenol and pharmaceuticals propranolol, fluoxetine, abamectin, doramectin and ivermectin. The toxicity values observed in the ingestion tests were very close to the mortality values over a wide range of toxicity from a low toxic surfactant to very toxic avermectins. The ratio between the 1 h EC50’s in the ingestion test and the 24 h LC50’s in the lethality test was below 2 in all cases for rotifers, and 7 in 9 cases for crustaceans. The toxicity of zinc and 3,5-dichlorophenol in the Thamnotoxkit F™ was 15-fold higher and 10 fold lower than in the ingestion test, respectively. The 24 h LC50 values are within the range of 25-400 % of the 1 h EC50 values for almost all toxicants tested with the exception of p-nitrophenol for B. calyciflorus and zinc and 3, 5-dichlorophenol for T. platyurus. Short, 1 h ingestion assays Rotoxrapid and Rapidtoxkit are good predictors of the mortality over the next 24 h and can be used as a range finding tests for representatives of pharmaceuticals and surfactants

Preliminary evaluation of cytotoxicity of the biomedical poly(ε-caprolactone)s obtained in the presence of tin octanoate

Otrzymano szereg próbek biomedycznego poli(ε-kaprolakton)u (PCL) stosując metodę polimeryzacji z otwarciem pierścienia katalizowanej 2-etyloheksanianem cyny (II). Uzyskane produkty polireakcji poddano operacji oczyszczania z pozostałości po katalizatorze cynoorganicznym. Zawartość metalu w otrzymanych polimerach oznaczano za pomocą elektrotermicznej absorpcyjnej spektrometrii atomowej. Toksyczność uzyskanych polimerów oceniano w odniesieniu do bakterii luminescencyjnych oraz dwóch pierwotniaków. Wstępne wyniki zaprezentowane w niniejszym artykule sugerują, że zastosowane operacje oczyszczania redukują zawartość cyny w polimerach bez ich degradacji. Można również stwierdzić, że polimery o zredukowanej zawartości cyny nie wykazują toksyczności w stosunku do bakterii luminescencyjnych V. fischeri oraz pierwotniaków S. ambiguum i T. termophila.A series of biomedical poly(ε-caprolactone)s were synthesized by the ring-opening polymerization of ε-caprolactone in the presence of tin(II) 2-ethylhexanoate. The obtained products were subjected to the purification procedures for removing the residual of tin catalyst. The metal content in the received polymers were determined using the Electrothermal Atomic Absorption Spectrometry. The toxicity of the resulted polymers was evaluated using bacterial luminescence test and two protozoan assays. The preliminary studies presented in this paper suggest that the purification of the polymers reduces tin concentration in the final products without causing product degradation. It was found that the purified polymers are not toxic relative to luminescent bacteria V. fischeri and two ciliated protozoans S. ambiguum and T. termophila

Examination of nuclear chirality with a magnetic moment measurement of the I = 9 isomeric state in 128^{128}Cs

International audienceThe g factor of the isomeric I=9+ bandhead of the yrast states in 128Cs is obtained from the time differential perturbed angular distribution measurement performed with the electromagnet at IPN Orsay. An external magnetic field of 2.146 T at the target position was attained with GAMIPE reaction chamber surrounded by four high-purity germanium detectors, of which two were low-energy photon spectrometer type. The results are in accordance with πh11/2⊗νh−111/2I=9+ bandhead assignment and are discussed in the context of chiral interpretation of the 128Cs nucleus as a composition of the odd proton, odd neutron, and even-even core with their angular momentum vectors. The obtained g-factor value was compared with predictions of the particle-rotor model. The experimental g factor corresponds to the nonchiral geometry of the isomeric bandhead. This observation indicates the existence of the chiral critical frequency in 128Cs and may explain the absence of the chiral doublet members for I<13

Analytical, Toxicological And Kinetic Investigation Of Decomposition Of The Drug Diclofenac In Waters And Wastes Using Gamma Radiation

The radiolytic decomposition of the drug diclofenac (DCF), and in limited extent, also two other widely used drugs, ibuprofen and carbamazepine, was examined using liquid chromatography (LC) methods. The efficiency of DCF decomposition was examined in function of the absorbed dose of gamma radiation, and also in the presence of selected scavengers of radicals, which are commonly present in natural waters and wastes. Three different tests were employed for the monitoring of toxicity changes in the irradiated DCF solutions. The LC/mass spectrometry (MS) was used for the determination of products of DCF radiolysis. Using pulse-radiolysis method with the spectrophotometric detection, the rate constant values were determined for reactions of DCF with the main products of water radiolysis: hydroxyl radicals (1.24 ± 0.02) × 1010 M−1 s−1 and hydrated electrons (3.1 ± 0.2) × 109 M−1 s−1. Their values indicate that both oxidative and reductive processes in radiolytic decomposition of DCF can take place in irradiated diluted aqueous solutions of DCF. The possibility of decomposition of all examined analytes was investigated in samples of river water and hospital waste. Compared to the previous studies, the conducted measurements in real samples were carried out at the concentration levels, which are close to those reported earlier in environmental samples., Graphical abstract ᅟPubMedWoSScopu