30 research outputs found
Elemental composition of plankton exometabolites (mucous macroaggregates): Control by biogenic and lithogenic components
Among the various exometabolitic effects of marine microorganisms, massive mucilage events in the coastal zones of temperate and tropical seas are the most spectacular and environmentally important. Abundant mucilage material in the form of aggregates appears in late spring/early summer in the water column of the Adriatic Sea. These macroaggregate biopolymers originate mainly from plankton exometabolites, with both autochthonous and allochthonous components, and strongly impact the tourism, fisheries, and economy of coastal countries. In contrast to extensive studies on the structural and chemical nature of macroaggregates performed over past decades, the full elemental composition of these substances remains poorly known, which does not allow for a complete understanding of their origin, evolution, and necessary remediation measures. Here, we report the results of comprehensive analyses of 55 major and trace elements in the composition of macro aggregates collected at the surface and in the water column during massive mucilage events. Through normalization of the elemental chemical composition of the upper earth crust (UCC), river suspended material (RSM), mean oceanic plankton, and mean oceanic particulate suspended material, we demonstrate that the water column macroaggregates reflect a superposition of the signal from plankton and marine particulate matter. The surface macroaggregates were preferentially enriched in lithogenic component, and carried the signature of planktonic material. The rare earth element (REE) signal was strongly dominated by plankton and, to a lesser degree, by oceanic particulate matter, while at the same time being strongly (>80 times) impoverished compared with UCC and RSM. Taken together, the elemental composition of macroaggregates allows for distinguishing the lithogenic and biogenic impacts on the occurrence of these unique large-scale mucilage events, linked to the exometabolism of marine plankton combined with the input of allochthonous inorganic material
Recurrent amelanotic melanoma of nasal cavity: Biological variability and unpredictable behavior of mucosal melanoma. A case report
The aim of this report is to present a case of a patient with a recurrent nasal cavity amelanotic melanoma (AM), with emphasis on diagnosis and therapy options of this clinical entity. A 65-year-old female patient presented with pain in the right cheek region and nasal obstruction. In 2013, she was diagnosed with mucosal melanoma (MM) of the left nasal cavity. After endoscopic surgery and radiotherapy, the patient was followed by the oncology team. Five years after the initial diagnosis, rhinoscopy showed a tumorous formation in the right nasal cavity. The tumor mass was without black discoloration and was the same color as the surrounding nasal mucosa. Microscopic examination after biopsy of the tumor confirmed amelanotic MM. The patient underwent an additional endoscopic surgery. A complete standard diagnostic workup for MM found metastases in head and neck lymph nodes, on both sides. MMs of head and neck are uncommon malignancies. Unique biology of MM cells causes a high rate of recurrences. This report presents an example of recurrent AM of the nasal cavity, in treatment with checkpoint inhibitor (pembrolizumab), which could provide a good therapy option for patients with MM
Nature and Lability of Northern Adriatic Macroaggregates
The key organic constituents of marine macroaggregates (macrogels) of prevalently phytoplankton origin, periodically occurring in the northern Adriatic Sea, are proteins, lipids and especially polysaccharides. In this article, the reactivity of various macroaggregate fractions in relation to their composition in order to decode the potentially »bioavailable« fractions is summarized and discussed. The enzymatic hydrolysis of the macroaggregate matrix, using α-amylase, β-glucosidase, protease, proteinase and lipase, revealed the simultaneous degradation of polysaccharides and proteins, while lipids seem largely preserved. In the fresh surface macroaggregate samples, a pronounced degradation of the α-glycosidic bond compared to β-linkages. Degradation of the colloidal fraction proceeded faster in the higher molecular weight (MW) fractions. N-containing polysaccharides can be important constituents of the higher MW fraction while the lower MW constituents can mostly be composed of poly- and oligosaccharides. Since the polysaccharide component in the higher MW fraction is more degradable compared to N-containing polysaccharides, the higher MW fraction represents a possible path of organic nitrogen preservation. Enzymatic hydrolysis, using α-amylase and β-glucosidase, revealed the presence of α- and β-glycosidic linkages in all fractions with similar decomposition kinetics. Our results indicate that different fractions of macroaggregates are subjected to compositional selective reactivity with important implications for macroaggregate persistence in the seawater column and deposition
Poland, Slovenia, the World : Challenges of present-day education
Publikacja recenzowana / Peer-reviewed publicationTransformations of education in changing Europe are multifaceted. One of the latter is the process of strengthening the cooperation among universities in this part of the world. This cooperation is carried out in many fields – from joint projects and researches – to joint analyses, discourses and publications. This monograph – a collection of reflections, thoughts and polemics deriving from theoretical and empirical researches, carried out as a part of a joint research project simultaneously undertaken at both these universities under the name “Problems and challenges of modern education” – constitutes one of the fruits of the cooperation between Andrzej Frycz Modrzewski Cracow University and the University of Ljubljana
Chemical characterisation of stromatolitic "petola" layer (Sečovlje salt-pans,Slovenia) using FT-IR spectroscopy
At Sečovlje salt-pans (Gulf of Trieste, northern Adriatic), the stromatolitic microbial mat named "petola" is crucial element in old mediaeval manner of salt-production, so the understanding of its chemistry is highly significant for the preservation and progress of this activity. The infrared spectra (FT-IR) of homogenized bulk samples were recorded to investigate the petola composition and modifications..
Healing mud from Secovlje saltpans
The Secovlje saltpans are the northernmost in the Adriatic Sea. Salt is recovered from sea by solar evaporation and during this process two side products are produced - salt pan mud and brine, both of which havehealing effects. Due to its balneological features, healing mud (peloid) is used to threat various diseases and to improve general health and well-being. In orderto determine the composition of the mud to be used for pelotherapy different chemical and mineralogical analysis were performed
Petola-stromatolitic basement for manual gathering of salt in Secovlje salina
In Secovlje salina (Gulf of Trieste, northern Adriatic), the stromatolitic microbial mat named "petola" is a crucial element in old mediaeval manner of salt-production so the understanding of its chemistry is very important for the preservation and progress of this activity. The chemical study (FT-IR, supp.13C-NMR, elemental analyses) was performed to investigate the petola composition and its transformations during salt-making processes
Chemical composition of natural sea salt from the Sečovlje salina (Gulf of Trieste, northern Adriatic)
In our research the concentrations of major and minor elements were determined in natural sea salts from the Sečovlje salina (Piran salts, Slovenia) and compared to those of selected samples of commercially available unrefined salts with different geographical origins (Croatia, Austria, Italy, Portugal, India, and Pakistan). In the case of major element contents such as sodium (Na), iron (Fe), aluminum (Al), manganese (Mn), and titanium (Ti) many similarities were observed among the analysed salt samples. On the other hand, Piran salts are characterized by lower silicon (Si) values. Among the salts from the Sečovlje salina, the salt with the trade name Piran salt has a higher Mg content while Flower of salt has a lower concentration of calcium (Ca). In Slovenian samples the majority of trace element values were lower than 0.5 μg g–1, which was comparable to the results from commercially available unrefined salts. The salt composition differences observed indicate area-specific signatures related to geographic origin and diverse salt production processes. The quality of the studied salt samples is in accordance with standards established by the Codex Alimentarius Commission and the Piran salts are also suitable regarding issues of national food control