The lake deposits in Płock Basin (case studies of Lakes Rakutowskie and Żłoby)
Reconstruction of development of Lakes Rakutowskie and Żłoby in the late Pleistocene and Holocene was the aim of this research. Analysis of content of calcium carbonate, organic matter and C14 datings (7 samples) were done for two cores of sediments of 750 cm long. An average rate of accumulation was counted. Sediments of Lake Rakutowskie show homogeneity along the core which indicates similarity of sedimentation conditions. Sediments of Lake Żłoby were diversified and show variety related to cyclic changes. A common feature is a thick layer of fine sand without carbonate deposited during the older dryas, shown in both cores. The difference in sediment features of both lakes (which have similar depths) indicates that the Lake Żłoby is the more dynamic, filtering element, preceding Lake Rakutowskie in system of water catchment.
Xerothermic grasslands are veritable botanical gems of the Ponidzie region, located in the upland zone of Poland. Most of these exceptional plant communities have been formed as a result of deforestation, in habitats characterized by specific climatic, hydrological and soil conditions. The result of the natural reserve protection of the xerothermic grassland, however, is opposite to the desired result. The survival of the xerothermic grassland depends on the change in the approach to their protection. Xerothermic grasslands are an excellent example of the difficulties with maintaining very valuable, but semi-natural and anthropogenic communities, related to a large extent to traditional, extensive forms of agriculture. Similar problems occur in the case of gladiolus meadows in lower subalpine forest zones or of once-mown molinion meadows in river valleys.
Motor organ injuries are one of the most common consequences of trauma, out of which comminuted fractures with a bone loss are the most challenging. Numerous methods are applied to treat these injuries; however, still in many cases we are unable to suggest successful medical treatment. Therefore, treating these injuries using elastic and surgically handleable bone replacement materials was started at Trauma Surgery and Emergency Medicine of Medical University of Lublin (provided for the experiments by Medical Inventi Lt). Preliminary assessment based on the results of treatment with bone replacement materials of two patients with comminuted fractures of femur was promising. Bone union was achieved without any adverse effects.
Introduction: Quercetin is a polyphenolic flavonoid which has been used in traditional Chinese medicine as a natural therapeutic agent with a broad spectrum of activities (antioxidant, anticancer, neuroprotective, anti-inflammatory, antiviral and antibacterial). The aim of this study was to develop and validate a rapid and simple ultra-high-performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) method for the determination of quercetin in milk.
Material and Methods: Sample preparation was based on a liquid-liquid extraction with 0.5% formic acid in acetonitrile. The chromatographic separation was performed on a ZORBAX SB-C18 column with methanol and 0.5% formic acid as a mobile phase.
Results: The procedure was successfully validated. The mean recovery of the analyte was 98%, with the corresponding intra- and inter-day variation less than 10% and 15%, respectively, and the repeatability and reproducibility were in the range of 3%–7.2% and 6.1%–12%, respectively. The lowest level of quantification was 1.0 μg/kg.
Conclusion: The proposed method was successfully applied in evaluating the pharmacokinetics of quercetin in milk obtained from dairy cows with clinical mastitis after intramammary administration.
Introduction: There are many veterinary products containing β-lactam antibiotics which are used for mastitis treatment in cows. The aim of the study was to determine whether mastitis could have any effect on amoxicillin (AMX) or penicillin G procaine (PEN) withdrawal period from milk, in the context of current maximum residue limits established by the European Commission.
Material and Methods: The study was conducted on 17 dairy Black and White cows with clinical mastitis during the lactation period. The first group (n = 8) received 200 mg of amoxicillin (AMX), whereas the second group (n = 9) received 200,000 IU/mg of penicillin G procaine (PEN) by intramammary administration. For the measurement of AMX and PEN concentrations in milk, the liquid chromatography tandem mass spectrometry method was applied. Pharmacokinetic calculations were performed using Phoenix WinNonlin 6.4 software.
Results: The determined AMX and PEN half-life values in the mammary gland suggest that the drug withdrawal is at a level of 99.9% within 81 h (≈3.5 days) and 116 h (≈5 days) after administration of AMX and PEN, respectively. The present research indicates that, at 60 h after administration, the average PEN concentration in the milk from cows with clinical signs of mastitis may still reach 4.96 g/kg and that of AMX can even be 6.92 g/kg.
Conclusion: The results obtained confirm that, in mastitis cases, a 72-h withdrawal period is sufficient for elimination of AMX to a lower level than the established maximum residue limit (MRL) values. However, in the case of PEN, at 69 h after administration, the drug concentration may be close to that of the determined MRL.
The aim of this study was to determine the correlation between lipophilicity and maximum residue limit (MRL) value specified for veterinary drugs in the fatty tissue of various animal species. The analysis was performed on a group of 73 compounds with different modes of action and MRL values determined for the fatty tissue of animals. Additionally, the logarithm of water/organic phase partition ratio (LogP) and the ratio of ionised and unionised substance in buffer with pH 7.4 (LogD7.4) were calculated. The main analysis was performed after the division of the whole group into six fractions. The linear correlation and regression analysis were used to determine the indirect relationship between the mean arithmetic value of LogP or LogD7.4 in selected fractions and related LogMRL of the drugs tested. The calculations revealed a linear correlation between fractioned lipophilicity and LogMRL values for the analysed compounds. The existence of indirect relationship between lipophilicity and MRL values determined for fatty tissue was confirmed.