Publications by authors named "Brzozowski R"

This study explores the controlled, continuous production of thin carbon rods between graphite electrodes (continued electrode deposits) during an arc discharge of high voltage alternating current with a frequency of 50 Hz in liquid paraffin, along with in situ doping of the resulting material using a suspension of liquid paraffin and iron powder ( <10 μm). The surface morphology of the obtained carbon rod nanomaterials was characterized using scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX), scanning transmission electron microscopy (STEM) with EDX chemical composition analysis, X-ray microtomography (micro-CT), and atomic force microscopy (AFM). The AFM technique in scanning thermal microscopy (SThM) and conductive probe (CP) modes was employed to determine the temperature and electrical conductivity of the obtained nanostructures.

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Ovine footrot is an infectious disease with important contributions from and . Footrot is characterized by separation of the hoof from underlying tissue, and this causes severe lameness that negatively impacts animal wellbeing, growth, and profitability. Large economic losses result from lost production as well as treatment costs, and improved genetic tools to address footrot are a valuable long-term goal.

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Purpose: During hostilities, gunshot wounds are the most common cause of penetrating injuries. In 8-10% of abdominal injuries kidneys are involved. The treatment method include surgical or conservative treatment (fluids + blood components).

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Staphylococcus aureus is a public health threat due to the prevalence of antibiotic resistance and the capacity of this organism to infect numerous organs in vertebrates. To generate energy needed to proliferate within tissues, S. aureus transitions between aerobic respiration and fermentation.

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Monitoring the extracellular environment for danger signals is a critical aspect of cellular survival. However, the danger signals released by dying bacteria and the mechanisms bacteria use for threat assessment remain largely unexplored. Here we show that lysis of cells releases polyamines that are subsequently taken up by surviving cells via a mechanism that relies on Gac/Rsm signaling.

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The article presents the method of producing gold nanoparticles using a high voltage arc discharge of alternating current with a frequency of 50 Hz in distilled water. The equipment necessary to carry out the process is described, including the construction of the reactor and the power source of a very simple design necessary to generate a high-voltage arc discharge between the electrodes. Arc discharge processes were carried out two times for 2 and 5 minutes, respectively, in ambient conditions without thermostating the reactor, at medium temperature varying in the range of 25-70 °C.

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Acinetobacter baumannii is a formidable opportunistic pathogen that is notoriously difficult to eradicate from hospital settings. This resilience is often attributed to a proclivity for biofilm formation, which facilitates a higher tolerance toward external stress, desiccation, and antimicrobials. Despite this, little is known regarding the mechanisms orchestrating A.

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Bacteria and their viruses (bacteriophages or phages) interact antagonistically and beneficially in polymicrobial communities such as the guts of animals. These interactions are multifaceted and are influenced by environmental conditions. In this review, we discuss phage-bacteria interactions as they relate to the complex environment of the gut.

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Through our continuous effort in developing a new class of foldamers, we have both designed and synthesized homogenous sulfono-γ-AApeptides using tetraphenylethylene (TPE) moieties attached to the backbone as luminogenic sidechains. Based on previous crystal structures, we have found that these foldamers adopted a left-handed 4-helix. Due to the constraint of the helical scaffold, the rotation of the TPE moieties were restricted, leading to fluorescent emissive properties with high quantum yields not only at the aggregate state but also in solution.

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The timely knowledge and prescription of the most suitable antibiotic to treat bacterial infections is critical for the recovery of patients battling life-threatening bacterial infections. Unfortunately, current standard-of-care approaches relies on the empiric prescription of an antibiotic, as determination of the most effective antibiotic requires multiple time-consuming steps. These steps often include culturing of the bacterium responsible for infection and subsequent antibiotic susceptibility testing.

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Although many bacterial cell division factors have been uncovered over the years, evidence from recent studies points to the existence of yet-to-be-discovered factors involved in cell division regulation. Thus, it is important to identify factors and conditions that regulate cell division to obtain a better understanding of this fundamental biological process. We recently reported that in the Gram-positive organisms and , increased production of YpsA resulted in cell division inhibition.

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Investigations of factors influencing cell division and cell shape in bacteria are commonly performed in conjunction with high-resolution fluorescence microscopy as observations made at a population level may not truly reflect what occurs at a single cell level. Live-cell timelapse microscopy allows investigators to monitor the changes in cell division or cell morphology which provide valuable insights regarding subcellular localization of proteins and timing of gene expression, as it happens, to potentially aid in answering important biological questions. Here, we describe our protocol to monitor phenotypic changes in Bacillus subtilis and Staphylococcus aureus using a high-resolution deconvolution microscope.

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Three dimensional (3D) supramolecules with giant cavities are attractive due to their wide range of applications. Herein, we used pentatopic terpyridine ligands with three types of coordination moieties to assemble two giant supramolecular hexagonal prisms with a molecular weight up to 42 608 and 43 569 Da, respectively. Within the prisms, two double-rimmed Kandinsky Circles serve as the base surfaces as well as the templates for assisting the self-sorting during the self-assembly.

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Aminoglycoside antibiotics require proton motive force (PMF) for bacterial internalization. In non-respiring populations, PMF drops below the level required for drug influx, limiting the utility of aminoglycosides against strict and facultative anaerobes. We recently demonstrated that rhamnolipids (RLs), biosurfactant molecules produced by Pseudomonas aeruginosa, potentiate aminoglycoside activity against Staphylococcus aureus.

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Aggregation-induced emission (AIE) was intensively studied because of packing of small molecules and polymers; however, mid-molecular-weight (1000-3000) molecular scaffold containing a precise number of AIE luminogens is rare. Herein, we report the investigation of three tetraphenylethylene (TPE)-modified sulfono-γ-AApeptides in which multiple TPE moieties are conjugated to the chiral right-handed helical peptidomimetic backbone as functional side chains. The crystal structure of the TPE-α/sulfono-γ-AA peptide demonstrates that because of the rigid helical scaffold of the TPE-α/sulfono-γ-AA peptides, the intramolecular rotations of the TPE with short linker are restricted, therefore leading to the boosted fluorescent emission in solution.

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Bacteria adapt to different environments by regulating cell division and several conditions that modulate cell division have been documented. Understanding how bacteria transduce environmental signals to control cell division is critical in understanding the global network of cell division regulation. In this article we describe a role for YpsA, an uncharacterized protein of the SLOG superfamily of nucleotide and ligand-binding proteins, in cell division.

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Binary fission has been well studied in rod-shaped bacteria, but the mechanisms underlying cell division in spherical bacteria are poorly understood. Rod-shaped bacteria harbor regulatory proteins that place and remodel the division machinery during cytokinesis. In the spherical human pathogen , we found that the essential protein GpsB localizes to mid-cell during cell division and co-constricts with the division machinery.

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Nested concentric structures widely exist in nature and designed systems with circles, polygons, polyhedra, and spheres sharing the same center or axis. It still remains challenging to construct discrete nested architecture at (supra)molecular level. Herein, three generations (G2-G4) of giant nested supramolecules, or Kandinsky circles, have been designed and assembled with molecular weight 17,964, 27,713 and 38,352 Da, respectively.

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Background: Application of a tourniquet in a tactical environment is implemented in two ways: the so-called self-aid, which is the application of a tourniquet by the injured, and the so-called buddy aid, which is the application of a tourniquet by the person provide aid. This study aimed to test the quality of tourniquet use in a simulated situation, close quarter battle.

Methods: The study involved 24 injured operators and 72 operators in the whole simulation, implying 12 sections of six individuals.

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The oral microbiome is a dynamic environment inhabited by both commensals and pathogens. Among these is Streptococcus mutans, the causative agent of dental caries, the most prevalent childhood disease. Carolacton has remarkably specific activity against S.

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Natural products commonly produced as secondary metabolites of various plants and micro-organisms represent a diverse chemical space of compounds. The diversity of natural products makes them an attractive target for interrogation by both chemists and biologists alike. Indeed, the study of 12-membered macrolactones has already led to the discovery of lead drug compounds and new biological targets, which has motivated the development of diverted total synthetic routes to libraries of analogs.

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It is assumed that tactical medicine encompasses all therapeutic activities performed by a military medical service during military and humanitarian missions. Its scope is only apparently limited by the standards which, when referred to the NATO member countries, have been collected in the Joint Theater Trauma System - Clinical Practice Guidelines. The stage-structured character of medical assistance and treatment of the wounded, injured and sick patients assumes that the scope of therapeutic activities performed at each stage is limited only to essential actions.

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A synthesis of carolacton, a myxobacterial natural product that has profound effects on Streptococcus mutans biofilms, is reported. The synthesis proceeds via a longest linear sequence of 14 steps from an Evans β-ketoimide and enabled preliminary evaluations of the effects of late-stage intermediates on S. mutans biofilms.

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In this study, a method of supercritical fluid extraction (SFE) with carbon dioxide of polyisoprenoids from plant photosynthetic tissues is described. SFE was an effective extraction method for short- and medium-chain compounds with even higher yield than that observed for the "classical extraction" method with organic solvents. Moreover, SFE-derived extracts contained lower amounts of impurities (e.

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