• Klíčová slova
• EXPERIMENTAL LAB STUDY *, FORMATES *, MICROSCOPY, ELECTRON *, OXIDOREDUCTASES *, PROTEUS *,
• MeSH
• aldehydoxidoreduktasy * MeSH
• elektronová mikroskopie * MeSH
• elektrony * MeSH
• formiáty * MeSH
• mikroskopie * MeSH
• oxidoreduktasy * MeSH
• Proteus vulgaris * MeSH
• Proteus * MeSH
• výzkum * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldehydoxidoreduktasy * MeSH
• formaldehyde dehydrogenase (glutathione) MeSH Prohlížeč
• formiáty * MeSH
• oxidoreduktasy * MeSH

• Klíčová slova
• EXPERIMENTAL LAB STUDY *, FORMATES *, MICROSCOPY, ELECTRON *, OXIDOREDUCTASES *, PROTEUS *,
• MeSH
• aldehydoxidoreduktasy * MeSH
• elektronová mikroskopie * MeSH
• elektrony * MeSH
• formiáty * MeSH
• mikroskopie * MeSH
• oxidoreduktasy * MeSH
• Proteus vulgaris * MeSH
• Proteus * MeSH
• výzkum * MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aldehydoxidoreduktasy * MeSH
• formaldehyde dehydrogenase (glutathione) MeSH Prohlížeč
• formiáty * MeSH
• oxidoreduktasy * MeSH

This article reports the numerical comparison of the quantities characterizing the extent of electron fluctuation and pair localization in the domains determined by the direct minimization of electron fluctuation with the domains resulting from the partitioning of the molecules based on the topological analysis of the so-called electron localization function (ELF). Such a comparison demonstrates that the ELF partitioning can be regarded as a feasible alternative to computationally much more demanding direct optimization of minimum fluctuation domains. This opened the possibility of the systematic scrutiny of the electron pair model of the chemical bond, and as it was demonstrated, the previous pessimistic claims about the applicability of this model are not completely justified.

• Publikační typ
• časopisecké články MeSH

Lyme borreliosis is a newly recognized systemic infection with protean clinical manifestations. Because the localization of the causative spirochete (Borrelia burgdorferi) in infected tissues is unknown, we used electron microscopy to find spirochetes in the hearts of chronically infected mice. There were three predominant locations for the spirochete in the hearts. In mice infected for one month or less, the spirochetes were mostly in or around blood vessels. They were either in the lumen or in the perivascular space. Mice infected for more than one month had B. burgdorferi in cardiac myocytes as well, often with clear spaces around them. The third area in which spirochetes were common was collagen fibers; the borreliae were wrapped around fibers with their long axis parallel to the fibers. The number of spirochetes was relatively low, but there was no appreciable decrease in numbers of spirochetes with increasing time postinfection. Inflammatory infiltrates were primarily in the endocardium and pericardium, but spirochetes were generally not in or near areas of inflammation. These data are consistent with previously published information that have identified the heart as a site of chronic infection and inflammation in the mouse. The studies extend our understanding of the behavior of the spirochete in vivo by identifying common locations of B. burgdorferi and by noting the disparity between infection and inflammation.

• MeSH
• bazální membrána parazitologie   MeSH
• Borrelia burgdorferi komplex izolace a purifikace   ultrastruktura   MeSH
• cévní endotel parazitologie   MeSH
• elektronová mikroskopie MeSH
• ELISA MeSH
• koronární cévy parazitologie   MeSH
• lymeská nemoc parazitologie   MeSH
• močový měchýř parazitologie   MeSH
• myokard patologie   MeSH
• myši inbrední C57BL MeSH
• myši inbrední DBA MeSH
• myši MeSH
• protilátky bakteriální krev   MeSH
• srdce parazitologie   MeSH
• western blotting MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• protilátky bakteriální MeSH

The location of lipoteichoic acid (LTA) on the surface of group A streptococci was studied by immunoelectron microscopic and ultrastructural cytochemical methods, i.e. by means of LTA antibodies labelled with ferritin, or concanavalin A labelled with ferritin or colloidal gold. All these methods proved the LTA to be located on the outer cell surface of most group A streptococcus strains. The differences in the intensity of labelling paralleled the hydrophobicity of the strains, being substantially higher in the strains exhibiting a high degree of hydrophobicity. Treatment of streptococci with pronase or trypsin led to a complete loss of surface-located LTA. On the other hand, pepsin treatment of streptococci under mild conditions resulted in an increased amount of surface-located LTA in some strains. On the isolated cell walls, LTA could be demonstrated only on the outer surface of the walls. These findings correlated well with the presumed role of group A streptococcus LTA in the adherence of streptococci to the epithelial cells which is accomplished with the aid of surface-located LTA molecules.

• MeSH
• bakteriální adheze MeSH
• buněčná stěna analýza   ultrastruktura   MeSH
• elektronová mikroskopie MeSH
• ferritiny MeSH
• imunohistochemie MeSH
• konkanavalin A MeSH
• kyseliny teichoové analýza   MeSH
• lipopolysacharidy analýza   MeSH
• protoplasty analýza   MeSH
• Streptococcus pyogenes analýza   ultrastruktura   MeSH
• zlato MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• ferritiny MeSH
• konkanavalin A MeSH
• kyseliny teichoové MeSH
• lipopolysacharidy MeSH
• lipoteichoic acid MeSH Prohlížeč
• zlato MeSH

Under electron microscope, the matrix of sectioned mitochondria exhibits ribosomes and an oval, electron-transparent zone which is devoid of ribosomes and is named chondriolite. Fine fibers or clumps of an electron-dense material appeared in this zone after several fixation and contrasting steps and were identified with mitochondrial DNA by cytologists. To verify this assumption, we labeled DNA by a monoclonal antibody and a secondary antibody coupled to immunogold. The label was observed in the nucleus and in the chondriolite zone of sectioned mitochondria. Because the ultrastructure of chondriolites resembles that of nucleoids of prokaryotes, we suggest the term mitochondrial nucleoid for the zone of mitochondrial matrix devoid of ribosomes and containing DNA.

• MeSH
• aspartátkarbamoyltransferasa analýza   MeSH
• DNA fungální analýza   MeSH
• imunoelektronová mikroskopie metody   MeSH
• karbamoylfosfátsynthasa (hydrolyzující glutamin) analýza   MeSH
• mitochondriální DNA analýza   MeSH
• mitochondrie chemie   ultrastruktura   MeSH
• multienzymové komplexy analýza   MeSH
• Saccharomyces cerevisiae - proteiny * MeSH
• Saccharomyces cerevisiae chemie   genetika   ultrastruktura   MeSH
• submitochondriální částice chemie   ultrastruktura   MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aspartátkarbamoyltransferasa MeSH
• DNA fungální MeSH
• karbamoylfosfátsynthasa (hydrolyzující glutamin) MeSH
• mitochondriální DNA MeSH
• multienzymové komplexy MeSH
• Saccharomyces cerevisiae - proteiny * MeSH
• URA2 protein, S cerevisiae MeSH Prohlížeč

The process of electron localization on a cluster of 32 water molecules at 20, 50, and 300 K is unraveled using ab initio molecular dynamics simulations. In warm, liquid clusters, the excess electron relaxes from an initial diffuse and weakly bound structure to an equilibrated, strongly bound species within 1.5 ps. In contrast, in cold, glassy clusters the relaxation processes is not completed and the electron becomes trapped in a metastable surface state with an intermediate binding energy. These results question the validity of extrapolations of the properties of solvated electrons from cold clusters of increasing size to the liquid bulk.

• Publikační typ
• časopisecké články MeSH

Pathogenic yeasts Candida albicans and Candida parapsilosis possess a ß-type carbonic anhydrase Nce103p, which is involved in CO2 hydration and signaling. C. albicans lacking Nce103p cannot survive in low CO2 concentrations, e.g., in atmospheric growth conditions. Candida carbonic anhydrases are orthologous to the Saccharomyces cerevisiae enzyme, which had originally been detected as a substrate of a non-classical export pathway. However, experimental evidence on localization of C. albicans and C. parapsilosis carbonic anhydrases has not been reported to date. Immunogold labeling and electron microscopy used in the present study showed that carbonic anhydrases are localized in the cell wall and plasmatic membrane of both Candida species. This localization was confirmed by Western blot and mass spectrometry analyses of isolated cell wall and plasma membrane fractions. Further analysis of C. albicans and C. parapsilosis subcellular fractions revealed presence of carbonic anhydrases also in the cytosolic and mitochondrial fractions of Candida cells cultivated in shaken liquid cultures, under the atmospheric conditions.

• Klíčová slova
• Candida albicans, Candida parapsilosis, Nce103p, carbonic anhydrase, cell wall, electron microscopy, localization, mass spectrometry,
• MeSH
• buněčná membrána enzymologie   MeSH
• buněčná stěna enzymologie   MeSH
• Candida albicans enzymologie   růst a vývoj   MeSH
• Candida parapsilosis enzymologie   růst a vývoj   MeSH
• cytosol enzymologie   MeSH
• elektronová mikroskopie MeSH
• fungální proteiny metabolismus   MeSH
• hmotnostní spektrometrie MeSH
• karboanhydrasy metabolismus   MeSH
• mitochondrie enzymologie   MeSH
• techniky vsádkové kultivace MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• fungální proteiny MeSH
• karboanhydrasy MeSH

In cryo-electron microscopy, accurate particle localization and classification are imperative. Recent deep learning solutions, though successful, require extensive training datasets. The protracted generation time of physics-based models, often employed to produce these datasets, limits their broad applicability. We introduce FakET, a method based on neural style transfer, capable of simulating the forward operator of any cryo transmission electron microscope. It can be used to adapt a synthetic training dataset according to reference data producing high-quality simulated micrographs or tilt-series. To assess the quality of our generated data, we used it to train a state-of-the-art localization and classification architecture and compared its performance with a counterpart trained on benchmark data. Remarkably, our technique matches the performance, boosts data generation speed 750×, uses 33× less memory, and scales well to typical transmission electron microscope detector sizes. It leverages GPU acceleration and parallel processing. The source code is available at https://github.com/paloha/faket/.

• Klíčová slova
• CryoEM, CryoET, deep learning, domain adaptation, forward model, machine learning, neural style transfer, surrogate model, synthetic data generation, transmission electron microscope,
• MeSH
• algoritmy MeSH
• deep learning * MeSH
• elektronová kryomikroskopie * metody   MeSH
• počítačové zpracování obrazu metody   MeSH
• software MeSH
• tomografie elektronová * metody   MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• aglutinace MeSH
• antigeny analýza   MeSH
• antisérum MeSH
• buněčná stěna imunologie   MeSH
• elektronová mikroskopie MeSH
• ferritiny * MeSH
• Francisella tularensis imunologie   patogenita   MeSH
• gama-globuliny * MeSH
• imunokomplex MeSH
• králíci MeSH
• Listeria monocytogenes imunologie   MeSH
• virulence MeSH
• zvířata MeSH
• Check Tag
• králíci MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny MeSH
• antisérum MeSH
• ferritiny * MeSH
• gama-globuliny * MeSH
• imunokomplex MeSH