Placenta is Capable of Protecting the Male Fetus from Exposure to Environmental Bisphenol A

Embryo-fetal exposure to bisphenol A (BPA) could be related to poor male reproductive parameters in rodents, but this concept has not been convincingly confirmed in humans. We investigated the association of environmental BPA exposure of pregnant women with selected endocrine and anthropometric parameters of male newborns. We analyzed plasma BPA from pregnant mothers, umbilical cord, and placental tissues (n = 117/each group) by liquid chromatography and mass spectrometry. LH, FSH, AMH, TGF beta 2, inhibin B, and selected sex steroids were measured in cord plasma. The infant anthropometric parameters included anogenital distance, stretched penile length, head circumference, birthweight, and length. The median BPA concentrations in maternal and umbilical cord plasma, and in placental tissue were 19.0, 8.0, and 22.2 nmol/L, respectively, the levels thus being over twofold lower in the fetal circulation than in the mother or placenta. The BPA concentrations measured were 100-1000-fold lower than those demonstrated in animal experiments to have endocrine disrupting effects. Multivariable regression analysis indicated no significant correlations between the maternal/fetal/placental BPA concentrations and any of the hormone levels or anthropometric parameter measured. Plasma concentrations of BPA confirmed both maternal, placenta, and fetal exposure to environmental BPA, but the concentrations were orders of magnitude lower than those with documented endocrine disrupting activity. Moreover, the maternal/fetal concentration gradient as well as the lack of correlations of BPA levels with any major endocrine or anthropometric parameters measured in the newborns suggest a protective role for the placenta in reducing fetal exposure to the environmental BPA

N-heterocyclic carbenes : synthesis and applications

N-Heterocyclic carbenes (NHCs) are powerful tools in organic chemistry, with numerous applications in academic and industrial laboratories. They are usually defined as singlet carbenes, in which the divalent carbonic centre is connected directly to at least one nitrogen atom in the heterocycle [1]. They have played an important role in organic chemistry ever since the first evidence of their existence. The isolation of stable, free 1,3‑diadamantylimidazol-2-ylidene (IAd, Fig. 1) by Arduengo et al. in 1991 was a milestone in the chemistry of carbenes [2]. From the beginnings as academic curiosities, N‑heterocyclic carbenes today are very useful compounds in a variety of organic transformations (Fig. 13). NHCs are neutral σ-donors, which form very strong bonds with the majority of transition metals (stronger than phosphines). These compounds are easy-to-make ligands with great potential in homogeneous catalysis (mainly ruthenium and palladium complexes) for large number of reactions, including the coupling reactions (Heck, Negishi, Stille, Suzuki or Sonogashira reactions) and olefin metathesis [3]. Moreover, they are very useful as organocatalysts used in the benzoin condensation, the Stetter reaction and ring-opening polymerization (ROP) or transesterification [4]. In this review, we aim to give an overview of the properties and applications of NHCs, which we expect will be a useful introduction for chemists interested in studying and applying these important compounds. The first part of this review is devoted to the main synthetic routes to NHCs, their properties and reactivity. In the second part we describe the metal complexes with NHCs as homogeneous catalysts and their applications in various types of reactions. At the end of this part of the paper the use of NHCs as organocatalysts is presented

Economic consequences of the 2016 storm in the Supraśl Forest District

The purpose of the article is to determine the value of losses resulting from salvage cutting of stands and to estimate the amount of extraordinary costs and profits from the sale of removed wood in forests damaged by a wind−storm that occurred on June 17, 2016 in the Supraśl Forest District (NE Poland). We obtained the following data from the State Forests Information System: the size of disaster area, the volume and structure of harvested wood in the affected area, extraordinary costs as a result of damage caused by a wind−storm, average sales price of downed or broken wood separated into individual recipients and entrepreneurs. The renewal of the disaster area has not been completed as for June 5, 2019. To determine the value of losses due to salvage felling of stands, formulas included in the Regulation of the Minister of the Environment of 20 June 2002 on one−time compensation for salvage felling of stands were used. Tables of stand value indicators developed by the Forest Research Institute in 2013 were used for the calculations. The total area of forests damaged by a wind−storm in the Supraśl Forest District was 329 ha. The area in which harvesting was carried out using a clear−cutting method covered 284 ha, the removal of damage in the remaining area was performed in accidental cuts. The total extraordinary costs incurred by the Supraśl Forest District as a result of a wind−storm amounted to over PLN 10.9 million, the largest group were costs related to harvesting and skidding of trees in disaster areas (nearly PLN 9.5 million). The total value of sales of large− and medium−sized wood assortments to retail customers was approximately PLN 1.93 million and to entrepreneurs over PLN 44.7 million. The value of small−sized assortments was at the level of PLN 37.5 thousand for retail customers and PLN 39.8 thousand for entrepreneurs. The value of forests damaged by a wind−storm was estimated at over PLN 20.3 million. A comprehensive analysis of the economic effects of the natural disaster in the Supraśl Forest District has not been completed; it requires research conducted in subsequent years, as the consequences and related costs of the hurricane will be experienced in the near future

Body mass analysis in patients with Hashimoto thyroiditis

Introduction: Hashimoto thyroiditis (HT) is one of the most common autoimmune thyroid disorders and o the most common cause of hypothyroidism, but the relation between TSH and body mass is still unclear. Material and methods: The group studied consisted of 53 patients with HT in euthyreosis and 28 healthy individuals. All the patients underwent thyroid ultrasonography and body mass analysis with the use of a medical analyzer INBODY 200. Blood samples were also analyzed for TSH and anti-thyroid antibodies. Results: The patients with HT had higher body mass (p=0.008), body mass index (BMI) (p=0.02), Waist-Hip Ratio (WHR) (0.01) and fat mass (p=0.02) than had the controls. In HT group increased body mass was observed in 72% of the patients (overweight in 38% and obesity in 35% of them), as compared with 38% of overweight/obesity in the control group. Thyroid volume was significantly lower (p=0.01) and anti-peroxidase antibodies level was two times higher in the group with the treatment period > 2 years, but the patients with relatively short treatment period were 7 kg heavier and their fat mass was 6 kg higher than in the subjects treated longer than 2 years. Conclusions: Our results suggest that the patients with HT, even in euthyreosis, have significantly higher body mass, BMI, WHR and fat mass than healthy individuals, which is probably associated with previous disturbances that led to the increase in fat mass at the stage of hypothyroidism. The observed changes tend to normalize during L-thyroxine replacement therapy

Three-dimensional organization of pyrrolo[3,2-b]pyrrole-based triazine framework using nanostructural spherical carbon: enhancing electrochemical performance of materials for supercapacitors

Abstract Covalent triazine-based frameworks have attracted much interest recently due to their high surface area and excellent thermal and electrochemical stabilities. This study shows that covalently immobilizing triazine-based structures on spherical carbon nanostructures results in the organization of micro- and mesopores in a three-dimensional manner. We selected the nitrile-functionalized pyrrolo[3,2-b]pyrrole unit to form triazine rings to construct a covalent organic framework. Combining spherical carbon nanostructures with the triazine framework produced a material with unique physicochemical properties, exhibiting the highest specific capacitance value of 638 F g−1 in aqueous acidic solutions. This phenomenon is attributed to many factors. The material exhibits a large surface area, a high content of micropores, a high content of graphitic N, and N-sites with basicity and semi-crystalline character. Thanks to the high structural organization and reproducibility, and remarkably high specific capacitance, these systems are promising materials for use in electrochemistry. For the first time, hybrid systems containing triazine-based frameworks and carbon nano-onions were used as electrodes for supercapacitors

Healing efficiency of polystyrene electrospun nanofibers with Grubbs' catalyst in thermosetting composite

The study presents a novel method for the protection of Grubbs' catalyst, by incorporation in polystyrene fibres via electrospinning technique. Epoxy-glass fibre composite with embedded self-healing agents (polystyrene fibres with Grubbs' and microcapsules with dicyclopentadiene) was processed. Fibres retained pale purple colour during processing, revealing that fibres provided good protection of the catalyst from the amine hardener. The influence of self-healing agents' content and thermal treatment on self-healing efficiency was investigated. Fourier transform infrared spectroscopy revealed that a polydicyclopentadiene formed at the healed interface. Thermal analysis revealed that bleed' at the healing sites from different samples had similar concentration of polydicyclopentadiene, indicating that the same amount of the catalyst has been provided to dicyclopentadiene for polymerization. This finding lead to assumption that electrospun polymer fibres enabled good dispersion of the catalyst in the composites. The low energy impact tests of the samples showed a recovery of 90% after 24h at room temperature and up to 111% after repeated heating cycles