Accurate lattice parameters from 3D electron diffraction data. I. Optical distortions

Determination of lattice parameters from 3D electron diffraction (3D ED) data measured in a transmission electron microscope is hampered by a number of effects that seriously limit the achievable accuracy. The distortion of the diffraction patterns by the optical elements of the microscope is often the most severe problem. A thorough analysis of a number of experimental datasets shows that, in addition to the well known distortions, namely barrel-pincushion, spiral and elliptical, an additional distortion, dubbed parabolic, may be observed in the data. In precession electron diffraction data, the parabolic distortion leads to excitation-error-dependent shift and splitting of reflections. All distortions except for the elliptical distortion can be determined together with lattice parameters from a single 3D ED data set. However, the parameters of the elliptical distortion cannot be determined uniquely due to correlations with the lattice parameters. They can be determined and corrected either by making use of the known Laue class of the crystal or by combining data from two or more crystals. The 3D ED data can yield lattice parameter ratios with an accuracy of about 0.1% and angles with an accuracy better than 0.03◦

Kompleksni pristup upravljanju sigurnosti na radu uz računalnu podršku

Requirements of the actual framework of directives of the European Union as well as national legal enactments demand the realization of systematic activities within the scope of risk management; and the task is to export to market such devices for which the value of residual risk is within the range of acceptable risk and to finally realize the steps of technical and human risk valuation in existing workplaces as well. These requests were the incentive for members of the realization team for development of a knowledge system which would be able to realize the selected method of risk valuation as a part of the preparation of production documentation to be realized by the system of computer aid for the technological preparation of the production program Sysklass. This solution realizes the approach of concurrent engineering where together during product development can be realized the steps which reveal the errors that may later appear as the source of an unfavorable event in the form of death, health hazards, technical system damage or environmental damage. Properties of the proposed and created knowledge system predict its usage in both the educational area during student training at our university and in technical praxis in the environment of safety management of smaller and middle-sized companies.Zahtjevi direktiva Europske Unije kao i državnih pravnih akata zahtjevaju realizaciju sistematskih aktivnosti u području upravljanja rizikom. Zadatak je ponuditi tržištu takve uređaje, za koje je vrijednost rezidualnog rizika u rasponu prihvatljivog rizika, i shvaćanje koraka za evaluaciju ljudskog i tehničkog rizika na postojećim radnim mjestima. Ovi zahtjevi su ponukali članove izvršnog tima za razvoj računalnog sustava znanja koji će biti u mogućnosti izvršiti evaluaciju rizika odabranom metodom u toku pripremanja proizvodne dokumentacije sa računalnom podrškom, pomoću programa Sysklass. Ovakvo rješenje objedinjuje pristup koji omogućava pronalaženje grešaka u procesu razvoja proizvoda koje mogu kasnije rezultirati neželjenim učinkom, npr. smrti, opasnosti po zdravlje, tehničkog oštećenja, ili zagađenja okoliša. Predstavljeni računalni sustav se može primjeniti u edukacijske svrhe za obrazovanje studenata, kao i u praksi u smislu rukovanja rizikom u malom i srednjem poduzetništvu

Searching for New Z-DNA/Z-RNA Binding Proteins Based on Structural Similarity to Experimentally Validated Zα Domain.

Z-DNA and Z-RNA are functionally important left-handed structures of nucleic acids, which play a significant role in several molecular and biological processes including DNA replication, gene expression regulation and viral nucleic acid sensing. Most proteins that have been proven to interact with Z-DNA/Z-RNA contain the so-called Zα domain, which is structurally well conserved. To date, only eight proteins with Zα domain have been described within a few organisms (including human, mouse, Danio rerio, Trypanosoma brucei and some viruses). Therefore, this paper aimed to search for new Z-DNA/Z-RNA binding proteins in the complete PDB structures database and from the AlphaFold2 protein models. A structure-based similarity search found 14 proteins with highly similar Zα domain structure in experimentally-defined proteins and 185 proteins with a putative Zα domain using the AlphaFold2 models. Structure-based alignment and molecular docking confirmed high functional conservation of amino acids involved in Z-DNA/Z-RNA, suggesting that Z-DNA/Z-RNA recognition may play an important role in a variety of cellular processes

Unheeded SARS-CoV-2 proteins? A deep look into negative-sense RNA.

SARS-CoV-2 is a novel positive-sense single-stranded RNA virus from the Coronaviridae family (genus Betacoronavirus), which has been established as causing the COVID-19 pandemic. The genome of SARS-CoV-2 is one of the largest among known RNA viruses, comprising of at least 26 known protein-coding loci. Studies thus far have outlined the coding capacity of the positive-sense strand of the SARS-CoV-2 genome, which can be used directly for protein translation. However, it has been recently shown that transcribed negative-sense viral RNA intermediates that arise during viral genome replication from positive-sense viruses can also code for proteins. No studies have yet explored the potential for negative-sense SARS-CoV-2 RNA intermediates to contain protein-coding loci. Thus, using sequence and structure-based bioinformatics methodologies, we have investigated the presence and validity of putative negative-sense ORFs (nsORFs) in the SARS-CoV-2 genome. Nine nsORFs were discovered to contain strong eukaryotic translation initiation signals and high codon adaptability scores, and several of the nsORFs were predicted to interact with RNA-binding proteins. Evolutionary conservation analyses indicated that some of the nsORFs are deeply conserved among related coronaviruses. Three-dimensional protein modeling revealed the presence of higher order folding among all putative SARS-CoV-2 nsORFs, and subsequent structural mimicry analyses suggest similarity of the nsORFs to DNA/RNA-binding proteins and proteins involved in immune signaling pathways. Altogether, these results suggest the potential existence of still undescribed SARS-CoV-2 proteins, which may play an important role in the viral lifecycle and COVID-19 pathogenesis

A Conditioning Sciatic Nerve Lesion Triggers a Pro-regenerative State in Primary Sensory Neurons Also of Dorsal Root Ganglia Non-associated With the Damaged Nerve

The primary sensory neurons of dorsal root ganglia (DRG) are a very useful model to study the neuronal regenerative program that is a prerequisite for successful axon regeneration after peripheral nerve injury. Seven days after a unilateral sciatic nerve injury by compression or transection, we detected a bilateral increase in growth-associated protein-43 (GAP-43) and superior cervical ganglion-10 (SCG-10) mRNA and protein levels not only in DRG neurons of lumbar spinal cord segments (L4-L5) associated with injured nerve, but also in remote cervical segments (C6-C8). The increase in regeneration-associated proteins in the cervical DRG neurons was associated with the greater length of regenerated axons 1 day after ulnar nerve crush following prior sciatic nerve injury as compared to controls with only ulnar nerve crush. The increased axonal regeneration capacity of cervical DRG neurons after a prior conditioning sciatic nerve lesion was confirmed by neurite outgrowth assay of in vitro cultivated DRG neurons. Intrathecal injection of IL-6 or a JAK2 inhibitor (AG490) revealed a role for the IL-6 signaling pathway in activating the pro-regenerative state in remote DRG neurons. Our results suggest that the pro-regenerative state induced in the DRG neurons non-associated with the injured nerve reflects a systemic reaction of these neurons to unilateral sciatic nerve injury

Řešení chodbových výztuží přípravných důlních děl na Dole Dukla v Šardicích

PrezenčníNeuvedenoNeuveden

Příprava, struktura a vlastnosti hybridních nanočástic s jádry perovskitového a spinelového typu

Přírodovědecká fakulta Univerzity Karlovy v Praze katedra anorganické chemie a Univerzita Štrasburk Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague and Université de Strasbourg Příprava nanokompozitů Fezos/Sioz z moleku!árního prekurzoru metodou so! gel a dopování Že|ezitých kationtů jinými trojmocnými kationty Preparation of Fezos/Sioz Nanocomposites from Molecutar Precursor by sol Gel Method and Doping of lron(lll) by Trivalent Metal Cations Souhrn disertačnípráce Summary of Thesis Petr Brázda Šrotitete(Supervisors): RNDr. Danie| NiŽňanský, PhD' Dr. Jean-Luc Rehspringer Praha 2009 Y Abstract Iron (III) oxide fonns two well-known polymorphs - the maghemite (y-Fe2O3), which is in fact a metastable phase, and is transformed into the hematite (cr-Fe2O3) at higher temperatures. At certain conditions, elusive e-Fe2O3 can be obtained as an intermediate between these two phases. e-Fe2O3 crystallizes in orlhorhombic space group Pna\ with lattice constants a: 509.5, b = 87g.9 and c:943.7 pm and is isomophous with r-A12O3, e-Ga2O3, AIFeO: and GaFeO3. Oxygen atoms form close pseudohexagonal packing with layers ABAC. kon cations occupy four different sites, three of them are octahedrally and one is tetrahedrally coordinated. There is eight formula units in unit cell. Structure of...Přírodovědecká fakulta Univerzity Kar|ovy v Praze katedra anorganické chemie a Univerzita Štrasburk Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague and Université de Strasbourg Příprava nanokompozitů Fezos/Sioz z mo!eku|árního prekurzoru metodou sol geI a dopování Že|ezitých kationtů jinými trojmocnými kationty Preparation of Fezog/Sioz Nanocomposites from Motecular Precursor by sol Gel Method and Doping of lron(lll) by Trivalent Metal Cations Souhrn disertačnípráce Summary of Thesis Petr Brázda Škotitele(Supervisors): RNDr. Daniel NiŽňanský, PhD. Dr. Jean-Luc Rehspringer Praha 2009 F Shrnutí oxid že|eziý tvoří dvě dobře známé modifikace - maghemit (y-Fe2o3), kteď je termodynamicky nestálý a pÍecházív hematit (cr-Fe2o3) při vyššíchteplotách. Za urěiých podmínek je možnépřipravit dalšínestálou modifikaci oxidu že|ezrtéhoa to modifikaci e-Fe2o3, na kterou je díky jejím strukturním vlastnostem a způsobu její přípravy nahlíženojako na přechodovou, fázi mezi maghemitem a hematitem' e-Fe2o3 lcystalizuje v ortorombické soustavě, a jeho struktura je popsána prostorovou grupou Pna21' MříŽovéparametry jsou a:509'5, b=878.9 a c=943'7 pm. e-Fe2o3 je izomorfní s r-A12o3, e-Ga2o3, A1Feo3 a GaFeo3. Kyslíkovéatomy tvoří nejtěsnější pseudohexagorrální uspořádání s vrstvením ABAC. Ze|ezité...Department of Inorganic ChemistryKatedra anorganické chemieFaculty of SciencePřírodovědecká fakult

Preparation of Fe2O3/SiO2 Nanocomposites from Molecular Precursor by Sol Gel Method and Doping of Iron(III) by Trivalent Metal Cations

Přírodovědecká fakulta Univerzity Karlovy v Praze katedra anorganické chemie a Univerzita Štrasburk Department of Inorganic Chemistry, Faculty of Science, Charles University in Prague and Université de Strasbourg Příprava nanokompozitů Fezos/Sioz z moleku!árního prekurzoru metodou so! gel a dopování Že|ezitých kationtů jinými trojmocnými kationty Preparation of Fezos/Sioz Nanocomposites from Molecutar Precursor by sol Gel Method and Doping of lron(lll) by Trivalent Metal Cations Souhrn disertačnípráce Summary of Thesis Petr Brázda Šrotitete(Supervisors): RNDr. Danie| NiŽňanský, PhD' Dr. Jean-Luc Rehspringer Praha 2009 Y Abstract Iron (III) oxide fonns two well-known polymorphs - the maghemite (y-Fe2O3), which is in fact a metastable phase, and is transformed into the hematite (cr-Fe2O3) at higher temperatures. At certain conditions, elusive e-Fe2O3 can be obtained as an intermediate between these two phases. e-Fe2O3 crystallizes in orlhorhombic space group Pna\ with lattice constants a: 509.5, b = 87g.9 and c:943.7 pm and is isomophous with r-A12O3, e-Ga2O3, AIFeO: and GaFeO3. Oxygen atoms form close pseudohexagonal packing with layers ABAC. kon cations occupy four different sites, three of them are octahedrally and one is tetrahedrally coordinated. There is eight formula units in unit cell. Structure of..