Cytotoxic and antioxidant activity of hypericum perforatum L. extracts against human melanoma cells from different stages of cancer progression, cultured under normoxia and hypoxia

Oxidative stress and the hypoxic microenvironment play a key role in the progression of human melanoma, one of the most aggressive skin cancers. The aim of our study was to evaluate the effect of Hypericum perforatum extracts of different origins (both commercially available (HpEx2) and laboratory-prepared from wild grown (HpEx12) and in vitro cultured (HpEx13) plants) and hyperforin salt on WM115 primary and WM266-4 lymph node metastatic human melanoma cells cultured under normoxic and hypoxic conditions. The polyphenol content, radical scavenging activity, and hyperforin concentration were determined in the extracts, while cell viability, apoptosis, ROS production, and expression of NRF2 and HO-1, important oxidative stress-related factors, were analyzed after 24 h of cell stimulation with HpExs and hyperforin salt. We found that cytotoxic, pro-apoptotic and antioxidant effects depend on the extract composition, the stage of melanoma progression, and the oxygen level. Hyperforin salt showed lower activity than H. perforatum extracts. Our study for the first time showed that the anticancer activity of H. perforatum extracts differs in normoxia and hypoxia. Importantly, the composition of extracts of various origins, including in vitro cultured, resulting in their unique properties, may be important in the selection of plants for therapeutic application

Functioning of the Photosynthetic Apparatus in Response to Drought Stress in Oat x Maize Addition Lines

The oat × maize chromosome addition (OMA) lines, as hybrids between C3 and C4 plants, can potentially help us understand the process of C4 photosynthesis. However, photosynthesis is often affected by adverse environmental conditions, including drought stress. Therefore, to assess the functioning of the photosynthetic apparatus in OMA lines under drought stress, the chlorophyll content and chlorophyll a fluorescence (CF) parameters were investigated. With optimal hydration, most of the tested OMA lines, compared to oat cv. Bingo, showed higher pigment content, and some of them were characterized by increased values of selected CF parameters. Although 14 days of drought caused a decrease of chlorophylls and carotenoids, only slight changes in CF parameters were observed, which can indicate proper photosynthetic efficiency in most of examined OMA lines compared to oat cv. Bingo. The obtained data revealed that expected changes in hybrid functioning depend more on the specific maize chromosome and its interaction with the oat genome rather than the number of retained chromosomes. OMA lines not only constitute a powerful tool for maize genomics but also are a source of valuable variation in plant breeding, and can help us to understand plant susceptibility to drought. Our research confirms more efficient functioning of hybrid photosynthetic apparatus than oat cv. Bingo, therefore contributes to raising new questions in the fields of plant physiology and biochemistry. Due to the fact that the oat genome is not fully sequenced yet, the mechanism of enhanced photosynthetic efficiency in OMA lines requires further research

Complex characterization of oat (Avena sativa L.) lines obtained by wide crossing with maize (Zea mays L.)

Background. The oat×maize addition (OMA) lines are used for mapping of the maize genome, the studies of centromere-specific histone (CENH3), gene expression, meiotic chromosome behavior and also for introducing maize C4 photosynthetic system to oat. The aim of our study was the identification and molecular-cytogenetic characterization of oat × maize hybrids. Methods. Oat DH lines and oat × maize hybrids were obtained using the wide crossing of Avena sativa L. with Zea mays L. The plants identified as having a Grande- 1 retrotransposon fragment, which produced seeds, were used for genomic in situ hybridization (GISH). Results. A total of 138 oat lines obtained by crossing of 2,314 oat plants from 80 genotypes with maize cv. Waza were tested for the presence of maize chromosomes. The presence of maize chromatin was indicated in 66 lines by amplification of the PCR product (500 bp) generated using primers specific for the maize retrotransposon Grande-1. Genomic in situ hybridization (GISH) detected whole maize chromosomes in eight lines (40%). All of the analyzed plants possessed full complement of oat chromosomes. The number of maize chromosomes differed between the OMA lines. Four OMA lines possessed two maize chromosomes similar in size, three OMA-one maize chromosome, and one OMA-four maize chromosomes. In most of the lines, the detected chromosomes were labeled uniformly. The presence of six 45S rDNA loci was detected in oat chromosomes, but none of the added maize chromosomes in any of the lines carried 45S rDNA locus. Twenty of the analyzed lines did not possess whole maize chromosomes, but the introgression of maize chromatin in the oat chromosomes. Five of 66 hybrids were shorter in height, grassy type without panicles. Twenty-seven OMA lines were fertile and produced seeds ranging in number from 1-102 (in total 613). Sixty-three fertile DH lines, out of 72 which did not have an addition of maize chromosomes or chromatin, produced seeds in the range of 1-343 (in total 3,758). Obtained DH and OMA lines were fertile and produced seeds. Discussion. In wide hybridization of oat with maize, the complete or incomplete chromosomes elimination of maize occur. Hybrids of oat and maize had a complete set of oat chromosomes without maize chromosomes, and a complete set of oat chromosomes with one to four retained maize chromosomes

Hexaazatriphenylenehexacarbonitrile and its complexes with halide anions: calculations and quantum chemical analysis of the electronic structure and spectroscopic properties.

W ostatnich latach niekowalencyjne oddziaływania między cząsteczkami organicznymicechującymi się deficytem π-elektronowym a anionami (określane mianem oddziaływań anion-π)budzą coraz większe zainteresowanie zarówno grup eksperymentalnych, jak i teoretycznych, zewzględu na ich duże potencjalne znaczenie praktyczne w różnych układach chemicznychi biologicznych. Jedną z najciekawszych cząsteczek cechujących się wspomnianym deficytemelektronowym jest 1,4,5,8,9,11-heksaazatrifenylenoheksakarbonitryl (HAT(CN)6), który – jakpokazują badania eksperymentalne – jest w stanie oddziaływać zarówno z prostymi,jak i złożonymi anionami, tworząc złożone sieci supramolekularne stabilizowane kontaktamitypu anion-π oraz barwne roztwory, w których postuluje się istnienie adduktów o charakterzedonorowo-akceptorowym, z przeniesieniem ładunku (CT) lub z przeniesieniem elektronu (ET)w zależności od rodzaju anionu. W pracy tej wykorzystano metodologię (TD-)DFT w połączeniuz analizą NCI i ETS-NOCV do zbadania strukturalnych, elektronowych i spektroskopowychwłaściwości kompleksów HAT(CN)6 z prostymi anionami reprezentującymi zarówno silne, jaki słabe zasady Lewisa, HAT(CN)6–X- z X- = F-, Cl-, Br-, I-, OH- i CN-. Przeprowadzone badaniaumożliwiły wskazanie preferowanego sposobu koordynacji anionu do receptora w rozważanychukładach, oszacowanie siły występującego w nich oddziaływania anion-π oraz określenie jegonatury ze wskazaniem i wyjaśnieniem w jaki sposób zmieniają się właściwości tych kompleksówze względu na zasadowość wchodzącego w jego skład anionu i jak wpływają one na własnościspektroskopowe (UV-Vis, 13C NMR) danego związku. Wykazano również możliwośćmodulowania siły oddziaływania anion-π poprzez modyfikowanie komponenty elektrostatycznejukładu aromatycznego.In recent years, non-covalent interactions between π-deficient organic molecules andanions (referred to as anion-π interactions) have attracted a growing interest from bothexperimental and theoretical groups, due to their high potential practical importance in variouschemical and biological systems. One of the most interesting π-acidic molecules is 1,4,5,8,9,11-hexaazatriphenylenehexacarbonitrile (HAT(CN)6), which – as shown by experimental studies –is able to interact with both simple and complex anions, forming complex supramolecularnetworks stabilized by anion-π contacts and colored solutions in which the existence of donoracceptor adducts is postulated, of either charge-transfer (CT) or electron-transfer (ET) character,depending on the nature of the anion. In this work the (TD-)DFT methodology in combinationwith NCI and ETS-NOCV analyses were used to study the geometric, electronic andspectroscopic properties of a series of HAT(CN)6 complexes with simple anions that representboth strong and weak Lewis bases, HAT(CN)6–X- with X- = F-, Cl-, Br-, I-, OH- and CN-.The calculations enabled us to indicate the preferred coordination mode of the anion to thereceptor in the considered systems, to assess the strength of the anion-π interaction that arepresent in these complexes and to determine its character. It was shown and explained how thisinteraction changes with the change of the anion's basicity and how its occurrence affectsspectroscopic properties (UV-Vis, 13C NMR) of the compound. Modulation of the strength of theanion-π interaction by tuning the electrostatic component of the aromatic system was alsodemonstrated

Molecular motors – theoretical analysis of selected bis-helicene systems

Heliceny to związki chemiczne zbudowane z π-sprzężonych ze sobą pierścieni. Oddziaływania między nimi powodują helikalne skręcenie struktury, a w efekcie chiralność tych układów pomimo braku centrów chiralnych w ich budowie. Unikalne własności chiralooptyczne helicen sprawiają, że związki te znajdują zastosowanie jako wielofunkcyjne materiały chiralne. W ostatnim czasie duże zainteresowanie grup eksperymentalnych budzi możliwość wykorzystania układów helicenowych jako motory, np. „zawiasy” molekularne. Celem projektu było opracowanie protokołu obliczeniowego opisu rotacji w układach helicenowych w celu wykazania cech pretendujących je do działania jako motory molekularne. Obliczenia wykonano metodą DFT dla układu bis-4-aza[6]heliceny analizując wpływ różnych szczegółów obliczeniowych (baza funkcyjna, funkcjonał DFT, efekty rozpuszczalnika, efekty dyspersji) na otrzymane wyniki. Analiza obliczonych profilów rotacji w badanym związku pokazuje, że uwzględnienie efektów dyspersyjnych metodą D3 powoduje asymetrię przebiegu obrotu z niższą barierą otrzymywaną przy przejściu przez strukturę, w której oba fragmenty helicenowe znajdują się w bezpośrednim sąsiedztwie. Asymetria ta wydaje się być jednak zbyt mała, aby zagwarantować preferencję obrotu i możliwość zastosowania tej bis-heliceny jako molekularnego „zawiasu”. Podobny przebieg profili rotacji obliczonych w fazie gazowej i rozpuszczalniku oraz w różnych bazach sugeruje, że opis rotacji w układach helicenowych można prowadzić z zastosowaniem mniejszej bazy i w fazie gazowej. Określenie znaczenia efektów dyspersyjnych wymaga dalszych badań.Helicenes are compounds composed of ortho-fused π-conjugated aromatic rings that, interacting with each other, lead to helically-shaped molecules. Consequenty, helicenes are chiral, in spite of absence of chiral centers in their structure. The resulting unique, large-magnitude chiroptical properties of these compounds make them promising candidates as optoelectronic materials. Furthermore, a possible application of helicene systems as molecular motors has been recently attracting a great interest. The main goal of the project was to develop a computational protocol to describe a rotation in helicene systems in order to examine their possible applications as molecular motors, using bis-4-aza[6]helicene as an example. Influence of different computational DFT details (basis function, exchange-correlation functional, solvent and dispersion effects) on the results obtained were analyzed. The calculated rotational profiles indicate that inclusion of dispersion effects with the D3 correction leads to an asymmetry of the profile with lower barrier obtained when passing through the structure in which the two helicenic parts are located in the immediate vicinity. This asymmetry seems however to be too small to guarantee the preferential direction of rotation and ability of bis-4-aza[6]helicene to act as molecular “hinge”. Qualitatively similar rotational profiles calculated without and with solvent effects and using different basis sets suggest that a description of the rotation in helicene systems may be performed with a smaller basis set and in the gas phase. Further analysis of dispersion effects is needed

Annual Plants and Thermoplastics in the Production of Polymer and Lignocellulose Boards

This study investigated the mechanical, physical, and thermal properties of three-layer particleboards produced from annual plant straws and three polymers: polypropylene (PP), high-density polyethylene (HDPE), and polylactic acid (PLA). The rape straw (Brassica napus L. var. Napus) was used as an internal layer, while rye (Secale L.) or triticale (Triticosecale Witt.) was applied as an external layer in the obtained particleboards. The boards were tested for their density, thickness swelling, static bending strength, modulus of elasticity, and thermal degradation characteristics. Moreover, the changes in the structure of composites were determined by infrared spectroscopy. Among the straw-based boards with the addition of tested polymers, satisfactory properties were obtained mainly using HDPE. In turn, the straw-based composites with PP were characterized by moderate properties, while PLA-containing boards did not show clearly favorable properties either in terms of the mechanical or physical features. The properties of straw–polymer boards produced based on triticale straw were slightly better than those of the rye-based boards, probably due to the geometry of the strands, which was more favorable for triticale straw. The obtained results indicated that annual plant fibers, mainly triticale, can be used as wood substitutes for the production of biocomposites. Moreover, the addition of polymers allows for the use of the obtained boards in conditions of increased humidity

Hospital Ethical Climate and Job Satisfaction among Nurses: A Scoping Review

The aim of this study was to map and summarize the published research findings on hospital ethical climate and its relationship with nursing staff job satisfaction as well as strategies proposed in the literature for the improvement of hospital ethical climate and job satisfaction through the actions of nursing staff in leadership positions. A scoping review has been performed in accordance with the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis extension scoping reviews statement (PRISMA-ScR). Three electronic bibliographic databases were searched: the SCOPUS, Medline, and CINHAL Complete using a combination of keywords with the range of years 1994–2021. A total of 15 papers out of 235 records identified were eligible for the analysis. The literature review confirmed a significant relationship between ethical climate and job satisfaction of nurses. Furthermore, the interdependence of ethical climate and job satisfaction of nursing staff affects many different aspects including patients, co-workers, an organization and research. Identifying factors that influence ethical climate and job satisfaction as well as the relationship between these variables may help to reduce the dropout concerning a change of profession among nursing staff