Publications by authors named "Polishchuk I"

Molybdenum is an essential micronutrient, but because of its toxicity at high concentrations, its accumulation in living organisms has not been widely demonstrated. In this study, we report that the marine sponge accumulates exceptionally high levels of molybdenum (46,793 micrograms per gram of dry weight) in a wide geographic distribution from the northern Red Sea to the reefs of Zanzibar, Indian Ocean. The element is found in various sponge body fractions and correlates to selenium.

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  • - The study explores the use of crystallographic defects, particularly twin boundaries, in gold (Au) substrates to enhance the growth of semiconductor nanocrystals like gold(I)-cyanide (AuCN), which have various applications.
  • - It discusses how twin boundaries create ledges that expose new crystal facets, facilitating the directed growth of AuCN on these surfaces in specific orientations.
  • - The findings suggest that controlling this growth could lead to nanoscale patterning of semiconductors, allowing adjustments to their properties, especially the band gap, which is crucial for electronic and optical applications.
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  • Lead-free perovskite nanocrystals are appealing for their nontoxicity and potential use in displays, but modifying their optical properties is challenging due to the complexities of exciton emissions.
  • This study explores how doping silver-based double perovskite nanocrystals with Bi and Sb can enhance their photoluminescence quantum yield, revealing that the two dopants impact the optical properties in distinct ways due to differences in electronic levels and ionic sizes.
  • The findings underscore the significance of ionic size and microstraining, particularly highlighting that Bi's larger size makes its optical properties more sensitive to doping concentration compared to Sb, suggesting ways to optimize these materials for future applications.
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This case report describes the occurrence of hyperbilirubinemia as a complication of metastatic melanoma. A 72-year-old male patient was diagnosed with BRAF V600E-mutated melanoma with metastases in the liver, lymph nodes, lungs, pancreas, and stomach. Due to a lack of clinical data and specific guidelines for the treatment of mutated metastatic melanoma patients with hyperbilirubinemia, a conference of specialists debated between initiating treatment or providing supportive care.

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Superhydrophobicity is a well-known wetting phenomenon found in numerous plants and insects. It is achieved by the combination of the surface's chemical properties and its surface roughness. Inspired by nature, numerous synthetic superhydrophobic surfaces have been developed for various applications.

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  • * This study reveals that adding single amino acids to manganese (II) carbonate alters its magnetic properties, particularly reducing magnetic susceptibility at room temperature.
  • * Below the Néel temperature, the magnetic susceptibility increases, indicating changes in orbital overlap and interactions, suggesting a new way to manipulate the magnetic characteristics of crystals using amino acids.
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The SARS-CoV-2 virus emerged at the end of 2019 and rapidly developed several mutated variants, specifically the Delta and Omicron, which demonstrate higher transmissibility and escalating infection cases worldwide. The dominant transmission pathway of this virus is via human-to-human contact and aerosols which once inhaled interact with the mucosal tissue, but another possible route is through contact with surfaces contaminated with SARS-CoV-2, often exhibiting long-term survival. Here we compare the adsorption capacities of the S1 and S2 subunits of the spike (S) protein from the original variant to that of the S1 subunit from the Delta and Omicron variants on self-assembled monolayers by Quartz Crystal ​Microbalance.

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Organisms deposit various biominerals in the course of their biomineralisation. The most abundant of these is calcium carbonate, which manifests itself in several polymorphs. While organisms possess the ability to control the specific polymorph deposited, the exact mechanism by which polymorph selection takes place is not yet fully understood.

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  • Many organisms use high-Mg nanoparticles within lower-Mg calcite matrices as a strategy to increase the strength of their skeletons during biomineralization.
  • This phase separation process occurs through spinodal decomposition of an amorphous Mg-calcite precursor and is influenced by the organism's Mg content rather than its biological type.
  • Evidence shows that only organisms with a magnesium content above 14 mol % exhibit these nanoparticles, highlighting their role in enhancing fracture resistance and hardness in biomineralized materials.
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This study investigates the effects of long-term exposure to OA on skeletal parameters of four tropical zooxanthellate corals naturally living at CO seeps and adjacent control sites from two locations (Dobu and Upa Upasina) in the Papua New Guinea underwater volcanic vent system. The seeps are characterized by seawater pH values ranging from 8.0 to about 7.

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Dislocations in metals affect their properties on the macro- and the microscales. For example, they increase a metal's hardness and strength. Dislocation outcrops exist on the surfaces of such metals, and atoms in the proximity of these outcrops are more loosely bonded, facilitating local chemical corrosion and reactivity.

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Soft corals (Cnidaria, Anthozoa, Octocorallia, Alcyonacea) produce internal sclerites of calcium carbonate previously shown to be composed of calcite, the most stable calcium carbonate polymorph. Here we apply multiple imaging and physical chemistry analyses to extracted and in-vivo sclerites of the abundant Red Sea soft coral, Ovabunda macrospiculata, to detail their mineralogy. We show that this species' sclerites are comprised predominantly of the less stable calcium carbonate polymorph vaterite (> 95%), with much smaller components of aragonite and calcite.

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Biominerals formed by organisms in the course of biomineralization often demonstrate complex morphologies despite their single-crystalline nature. This is achieved owing to the crystallization via a predeposited amorphous calcium carbonate (ACC) phase, a precursor that is particularly widespread in biominerals. Inspired by this natural strategy, we used robocasting, an additive manufacturing three-dimensional (3D) printing technique, for printing 3D objects from novel long-term, Mg-stabilized ACC pastes with high solids loading.

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Strategies to capitalize on enolate intermediates generated from stereoselective conjugate borylation to α,β-unsaturated carbonyl systems are surprisingly rare despite the ubiquity of Michael acceptors, and the potential to generate valuable scaffolds bearing multiple stereocenters. Herein, we report a mild and stereoselective copper-catalyzed conjugate borylation/Mannich cyclization reaction. This strategy is feasible with a broad range of Michael acceptors, and can be leveraged to generate versatile borylated tetrahydroquinoline scaffolds bearing three contiguous stereocenters.

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  • The calcareous alga Jania sp. is a complex articulated coralline red seaweed found in shallow ocean waters, showing a hierarchical structure that enhances compliance.
  • New findings reveal that its cell wall consists of layers with varying magnesium and calcium content, which helps prevent fractures from cracks.
  • This study introduces the idea of Mg-rich nanoparticles in Jania sp. and its similarity to another species, Corallina sp., highlighting potential applications for improving material design based on biological strategies.
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Systemic capillary leak syndrome (SCLS) is a life-threatening disease. It is characterized by severe capillary hyperpermeability to proteins resulting in hemoconcentration, hypoalbuminemia and hypovolemic shock. Its treatment remains supportive, and the prognosis is generally poor.

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Understanding how marine taxa will respond to near-future climate changes is one of the main challenges for management of coastal ecosystem services. Ecological studies that investigate relationships between the environment and shell properties of commercially important marine species are commonly restricted to latitudinal gradients or small-scale laboratory experiments. This paper aimed to explore the variations in shell features and growth of the edible bivalve Chamelea gallina from the Holocene sedimentary succession to present-day thanatocoenosis of the Po Plain-Adriatic Sea system (Italy).

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Half-sandwich iridium complexes bearing bidentate urea-phosphorus ligands were found to catalyze the direct reductive amination of aromatic and aliphatic ketones under mild conditions at 0.5 mol % loading with high selectivity towards primary amines. One of the complexes was found to be active in both the Leuckart-Wallach (NH CO H) type reaction as well as in the hydrogenative (H /NH AcO) reductive amination.

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  • Carbohydrates, particularly acidic monosaccharides like glucuronic and galacturonic acids, significantly affect the formation of calcite crystals during biomineralization.
  • In this study, it was found that these monosaccharides not only change the size and shape of calcite crystals but also become part of the crystal structure, causing distortions in the lattice.
  • High-resolution X-ray diffraction techniques were used to accurately analyze these changes, highlighting the potential importance of saccharides in biomineralization processes.
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A versatile and highly stereoselective borylative cyclization to generate polyfunctionalized γ-lactams has been developed. The stereoselective synthesis of these key ring systems is crucial due to their ubiquity in natural products. We report the diastero- and enantioselective construction of di- and trisubstituted γ-lactam cores, with examples containing an enantioenriched quaternary carbon.

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  • The study investigated how sex affects the presentation, causes, and outcomes of infective endocarditis (IE) by analyzing data from 214 adult patients.
  • Significant differences were noted in the types of bacteria causing IE in males versus females, particularly with coagulase-negative staphylococcus and culture-negative endocarditis.
  • Although in-hospital mortality rates were similar, females had a higher overall mortality rate compared to males, indicating that sex might influence the microbial profile and outcomes of IE.
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A process of atomic layer deposition (ALD) combined with self-assembled monolayers (SAMs) was used to investigate the possible modification of the wetting properties of polyurethane (PUR) paint surfaces without altering their original hue. First, we used an ALD process to produce thin and uniform AlO coatings of these surfaces at temperatures as low as 80 °C. We then successfully achieved the addition of 16-phosphono-hexadecanoic acid (16-PHA) SAMs to the AlO-coated paint samples.

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Through controlled biomineralization, organisms yield complicated structures with specific functions. Here, sp., an articulated coralline red alga that secretes high-Mg calcite as part of its skeleton, is in focus.

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Background: There is a lack of information regarding acute pancreatitis in Israel. However, the most prevalent worldwide etiologic causes of acute pancreatitis are biliary stones and alcohol abuse.

Objectives: To delineate the prevalence, main causes, rate of recurrence, mortality, and complications of acute pancreatitis in southern Israel.

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Reef-building corals, the major producers of biogenic calcium carbonate, form skeletons in a plethora of morphological forms. Here we studied skeletal modifications of Stylophora pistillata (clade 4) colonies that adapt to increasing depths with decreasing ambient light. The coral show characteristic transitions from spherical morphologies (shallow depths, 5 m deep) to flat and branching geometries (mesophotic depths, 60 m deep).

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