44 research outputs found

    Influence of structural changes of Co78Si9B13 metallic glass on magnetic properties

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    The primary crystallization of Co78Si9B13 metallic glass starts at 648 K and as a consequence of this the ε-Co(Si) phase with needle morphology is created. The second stage of crystallization (at 773 K) is the eutectic and as a result of this α-Co(Si) and boron phases: (Co,Si)3B, (Co,Si)2B are formed. The crystallites of these phases have layer morphology. These characteristic morphologies in the first and second stages lead to the increase in coercivity

    Occurrence of arbuscular mycorrhizal fungi in the roots of two grapevine cultivars in response to bioproducts

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    The aim of this study was to determine the influence of different bioproducts on the occurrence of arbuscular mycorrhizal fungi (AMF) in the roots of ‘Solaris’ and ‘Regent’ grapevine cultivars. The following bioproducts were used, alone or with mineral fertilization (NPK): Ausma, Bioilsa, manure and BF Ekomix. The highest mycorrhizal frequency was recorded in the roots of ‘Solaris’ after applying the bioproduct Ausma. For the ‘Regent’ cultivar, the highest mycorrhizal frequency was found in the plants treated with Ausma, BF Ekomix and manure. Colonization of grapevine roots by AM fungi was limited bymineral fertilization. After the combined use of bioproducts and mineral fertilizers, there was observed a tendency for minimized negative effect of mineral fertilization on the formation of arbuscular mycorrhizal fungi

    An update on the epidemiology, imaging and therapy of brain metastases

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    Introduction.The incidence of brain metastases (BM) is rapidly increasing, with most cases occurring in patients aged 50–80 years and in 10–40% of patients with systemic neoplastic disease. The Graded Prognostic Assessment (GPA) is the most impartial prognostic method, according to which the average survival rate of patients with brain metastases is only 7.18 months. Purpose.To present a systematic review of the currently available evidence-based literature on the epidemiology, dia­gnosis, and treatment of BM. Methods.The authors searched PubMed up to March 2020 using the phrases “brain metastases”, “brain metastasis surgery”, and “brain metastases treatment”, which returned 65 citations. Conclusions.The choice of imaging and therapy for brain metastases remains a significant clinical problem. MRI, including T1, T1 + C, T2, FLAIR, and SWI sequences, is the most sensitive method for solitary BM detection, while other techniques such as spectroscopy, perfusion imaging, or fractional anisotropy contribute to diagnosis precision and neurological deficit avoidance in cases eligible for surgery. According to current treatment algorithms, three main methods are used to mana­ge BM: surgery, chemotherapy, and radiotherapy, depending on the expected effect and the patient’s clinical condition. Surgery is most often used, offering neurological deficit remission in 60 to 90% of patients. Most chemotherapeutics do not cross the blood-brain barrier, so immunotherapy with antibodies such as pembrolizumab and ipilimumab, as well as antineoplastic vaccines, are a promising therapeutic prospect

    Cryopreservation of Plant Tissues in Poland: Research Contributions, Current Status, and Applications

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    Cryopreservation of vegetatively propagated plant material is an increasingly widely used method for the efficient and safe storage of germplasm resources around the world. In Poland, there are currently four cryobanks in use for long-term plant protection programs. However, plant tissues propagated in vitro constitute only a small portion of the accessions stored in them. To date, cryogenic storage techniques have been developed and adopted in this country for ornamental plants (roses, chrysanthemums, and geophytes), crop species (potato and garlic), forest tree species (the genera Quercus and Fraxinus), and some ferns. Polish researchers have used suspension cultures of Gentiana spp. and shoot tips of Lamprocapnos spectabilis to improve cryopreservation knowledge. A better understanding of the benefits of cryopreservation and its widespread implementation in plant biodiversity conservation programs is required. The objective of this review is to provide a concise synthesis of the scientific contributions, current status, and applications of cryogenic techniques for the conservation of in vitro culture-derived plant tissues in Poland. First, the results contributing to research that has been achieved using cell suspensions and advances related to the use of nanoparticles and plant extracts to improve cryopreservation efficiency are discussed. Then, the applications and advances in cryopreservation of ornamental plants (roses, radiomutants, plant chimeras, Lamprocapnos spp., and geophytes), crop species (potato and garlic), forest trees, and ferns are summarized

    Prenatal diagnosis of Smith-Lemli-Opitz syndrome – case report

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    Abstract Smith-Lemli-Opitz syndrome (SLOS) is a hereditary, autosomal recessive abnormality of cholesterol metabolism, leading to malformations of multiple organs. It is probably one of the most frequent metabolic disorders but variable clinical presentation makes the diagnosis of the syndrome difficult. The authors of the following work present a case report of prenatal diagnosis of SLOS in fetus with malformations of multiple organs and negative family history

    Holoprosencephaly – a case report

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    Abstract Holoprosencephaly is a brain malformation caused by abnormal division of the forebrain into two separate hemispheres. Abnormal structures of the central nervous system often occur with other midline forebrain and face failures. In this report we present a case of a prenatal diagnosis of holoprosencephaly

    The Stereochemistry of the Reduction of Cyclic Enaminones

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    B Chromosomes and Cytogenetic Characteristics of the Common Nase Chondrostoma nasus (Linnaeus, 1758)

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    Supernumerary B chromosomes (Bs) are very promising structures, among others, in that they are an additional genomic compartment for evolution. In this study, we tested the presence and frequency of B chromosomes and performed the first cytogenetic examination of the common nase (Chondrostoma nasus). We investigated the individuals from two populations in the Vistula River basin, in Poland, according to the chromosomal distribution of the C-bands and silver nucleolar organizer regions (Ag-NORs), using sequential staining with AgNO3 and chromomycin A3 (CMA3). Furthermore, we analyzed the chromosomal localization of two rDNA families (45S and 5S rDNA) using fluorescence in situ hybridization (FISH) with rDNA probes. Chondrostoma nasus individuals showed a standard (A) chromosome set consisting of 2n = 50: 12 metacentric, 32 submetacentric, and 6 acrocentric chromosomes (NF = 94). Fourteen out of the 20 analyzed individuals showed 1–2 mitotically unstable submetacentric B chromosomes of different sizes. Six of them, in 14.1% of the analyzed metaphase plates, had a single, medium-sized submetacentric B (Bsm) chromosome (2n = 51) with a heterochromatic block located in its pericentromeric region. The other seven individuals possessed a Bsm (2n = 51) in 19.4% of the analyzed metaphase plates, and a second Bsm chromosome (2n = 52), the smallest in the set, in 15.5% of metaphase plates, whereas one female was characterized by both Bsm chromosomes (2n = 52) in 14.3% of the analyzed metaphase plates. AgNORs, GC-rich DNA sites, and 28S rDNA hybridization sites were observed in the short arms of two submetacentric chromosome pairs of A set. The constitutive heterochromatin was visible as C bands in the centromeric regions of almost all Chondrostoma nasus chromosomes and in the pericentromeric region of several chromosome pairs. Two 5S rDNA hybridization sites in the pericentromeric position of the largest acrocentric chromosome pair were observed, whereas two other such sites in co-localization on a smaller pair of NOR chromosomes indicate a species-specific character. The results herein broaden our knowledge in the field of B chromosome distribution and molecular cytogenetics of Chondrostoma nasus: a freshwater species from the Leuciscidae family

    Weak Interactions in the Structures of Newly Synthesized (–)-Cytisine Amino Acid Derivatives

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    Eight new (–)-(N-[(AA)-(N-phtaloyl)]cytisines (where AA is amino acid: glycine, β-alanine, D,L-valine, L-valine, L-isoleucine, L-leucine, D-leucine and D,L-phenyloalanine), were synthesized and fully spectroscopically characterized (NMR, FTIR and MS). For two of these compounds, N-[glycine-(N-phtaloyl)]cytisine and N-[L-isoleucine-(N-phtaloyl)]cytisine, X-ray crystal structures were obtained and used as the basis for an in-depth analysis of intermolecular interactions and packing energies. The structural geometrical data (weak hydrogen bonds, π···π interactions, etc.) were compared with the energies of interactions and the topological characteristics (electron density, Laplacian at the appropriate critical point) based on the atoms-in-molecules theory. The results suggest that there is no straightforward connection between the geometry of point-to-point interactions and the molecule-to-molecule energies. Additionally, the usefulness of the transfer of multipolar parameters in estimating of critical points’ characteristics have been confirmed
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