Kaválny filter umožňuje zabrániť pľúcnej embólii mechanickým zachytením embolu v dolnej dutej žile. Mal by byť prísne indikovaný a implantovaný len vo vybranej skupine pacientov s hlbokou žilovou trombózou. Avšak zavedenie plejády relatívnych indikácií významne zvýšilo mieru implantácie kaválneho filtra v poslednej dekáde, čo samozrejme viedlo aj k neúmernému nárastu komplikácií. Účelom tohto článku je zosumari- zovať možné komplikácie súvisiace s používaním kaválneho filtra, predstaviť čitateľovi ich klinickú manifestáciu, nakoľko sú často prehliadané, a zároveň ukázať možnosti riešenia a liečby jednotlivých komplikácií.

The inferior vena cava filter prevents pulmonary embolism by mechanically trapping the embolus in the inferior vena cava. It should be strictly indicated and implanted only in a selected group of patients with deep vein thrombosis. However, the introduction of a plenty relative indications significantly increased the rate of caval filter implantation in the last decade and it led consequently to dramatic increase of complications rate, too. The purpose of this article is to summarize the possible complications related to the use of the caval filter, to present the reader clinical manifestation of these complications, as they are often overlooked, and to show the possibilities of solving and treating individual complications.

• MeSH
• antikoagulancia terapeutické užití   MeSH
• diagnostické zobrazování metody   MeSH
• kavální filtry * škodlivé účinky   MeSH
• krvácení etiologie   MeSH
• lidé MeSH
• migrace cizích těles etiologie   MeSH
• plicní embolie prevence a kontrola   MeSH
• pooperační komplikace prevence a kontrola   MeSH
• ruptura etiologie   MeSH
• žilní tromboembolie * komplikace   terapie   MeSH
• Check Tag
• lidé MeSH

Na(+)/H(+) antiporters may recognize all alkali-metal cations as substrates but may transport them selectively. Plasma-membrane Zygosaccharomyces rouxii Sod2-22 antiporter exports Na(+) and Li(+), but not K(+). The molecular basis of this selectivity is unknown. We combined protein structure modeling, site-directed mutagenesis, phenotype analysis and cation efflux measurements to localize and characterize the cation selectivity region. A three-dimensional model of the ZrSod2-22 transmembrane domain was generated based on the X-ray structure of the Escherichia coli NhaA antiporter and primary sequence alignments with homologous yeast antiporters. The model suggested a close proximity of Thr141, Ala179 and Val375 from transmembrane segments 4, 5 and 11, respectively, forming a hydrophobic hole in the putative cation pathway's core. A series of mutagenesis experiments verified the model and showed that structural modifications of the hole resulted in altered cation selectivity and transport activity. The triple ZrSod2-22 mutant T141S-A179T-V375I gained K(+) transport capacity. The point mutation A179T restricted the antiporter substrate specificity to Li(+) and reduced its transport activity, while serine at this position preserved the native cation selectivity. The negative effect of the A179T mutation can be eliminated by introducing a second mutation, T141S or T141A, in the preceding transmembrane domain. Our experimental results confirm that the three residues found through modeling play a central role in the determination of cation selectivity and transport activity in Z. rouxii Na(+)/H(+) antiporter and that the cation selectivity can be modulated by repositioning a single local methyl group.

• MeSH
• bodová mutace MeSH
• draslík metabolismus   MeSH
• fungální proteiny chemie   genetika   metabolismus   MeSH
• hydrofobní a hydrofilní interakce MeSH
• kationty metabolismus   MeSH
• konformace proteinů MeSH
• lithium metabolismus   MeSH
• molekulární modely MeSH
• molekulární sekvence - údaje MeSH
• Na(+)-H(+) antiport chemie   genetika   metabolismus   MeSH
• sekvence aminokyselin MeSH
• sodík metabolismus   MeSH
• substrátová specifita MeSH
• Zygosaccharomyces chemie   genetika   metabolismus   MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Proper respiratory tract protection is the key factor to limiting the rate of COVID-19 spread and providing a safe environment for health care workers. Traditional N95 (FFP2) respirators are not easy to regenerate and thus create certain financial and ecological burdens; moreover, their quality may vary significantly. A solution that would overcome these disadvantages is desirable. In this study a commercially available knit polyester fleece fabric was selected as the filter material, and a total of 25 filters of different areas and thicknesses were prepared. Then, the size-resolved filtration efficiency (40-400 nm) and pressure drop were evaluated at a volumetric flow rate of 95 L/min. We showed the excellent synergistic effect of expanding the filtration area and increasing the number of filtering layers on the filtration efficiency; a filter cartridge with 8 layers of knit polyester fabric with a surface area of 900 cm2 and sized 25 × 14 × 8 cm achieved filtration efficiencies of 98% at 95 L/min and 99.5% at 30 L/min. The assembled filter kit consists of a filter cartridge (14 Pa) carried in a small backpack connected to a half mask with a total pressure drop of 84 Pa at 95 L/min. In addition, it is reusable, and the filter material can be regenerated at least ten times by simple methods, such as boiling. We have demonstrated a novel approach for creating high-quality and easy-to-breathe-through respiratory protective equipment that reduces operating costs and is a green solution because it is easy to regenerate.

• MeSH
• aerosoly MeSH
• COVID-19 * prevence a kontrola   MeSH
• design vybavení MeSH
• filtrace metody   MeSH
• lidé MeSH
• masky MeSH
• polyestery MeSH
• prostředky na ochranu dýchání * MeSH
• testování materiálů metody   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Potassium ion (K+) uptake in yeast is mediated mainly by the Trk1/2 proteins that enable cells to survive on external K+ concentration as low as a few μM. Fungal Trks are related to prokaryotic TRK and Ktr and plant HKT K+ transport systems. Overall sequence similarity is very low, thus requiring experimental verification of homology models. Here a refined structural model of the Saccharomyces cerevisiae Trk1 is presented that was obtained by combining homology modeling, molecular dynamics simulation and experimental verification through functional analysis of mutants. Structural models and experimental results showed that glycines within the selectivity filter, conserved among the K-channel/transporter family, are not only important for protein function, but are also required for correct folding/membrane targeting. A conserved aspartic acid in the PA helix (D79) and a lysine in the M2D helix (K1147) were proposed earlier to interact. Our results suggested individual roles of these residues in folding, structural integrity and function. While mutations of D79 completely abolished protein folding, mutations at position 1147 were tolerated to some extent. Intriguingly, a secondary interaction of D79 with R76 could enhance folding/stability of Trk1 and enable a fraction of Trk1[K1147A] to fold. The part of the ion permeation path containing the selectivity filter is shaped similar to that of ion channels. However below the selectivity filter it is obstructed or regulated by a proline containing loop. The presented model could provide the structural basis for addressing the long standing question if Trk1 is a passive or active ion-translocation system.

• MeSH
• buněčná membrána chemie   metabolismus   MeSH
• draslík metabolismus   MeSH
• gating iontového kanálu * MeSH
• glycin MeSH
• kinetika MeSH
• konformace proteinů MeSH
• konzervovaná sekvence MeSH
• kyselina asparagová MeSH
• lysin MeSH
• molekulární sekvence - údaje MeSH
• mutace MeSH
• mutageneze cílená MeSH
• permeabilita buněčné membrány MeSH
• proteiny přenášející kationty chemie   genetika   metabolismus   MeSH
• Saccharomyces cerevisiae - proteiny chemie   genetika   metabolismus   MeSH
• sbalování proteinů MeSH
• sekvence aminokyselin MeSH
• simulace molekulární dynamiky MeSH
• stabilita proteinů MeSH
• výpočetní biologie MeSH
• vztahy mezi strukturou a aktivitou MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

Cíl: Používání filtroventrilačních systémů v městských autobusech ve vyspělých zemích zvyšuje komfort a kvalitu vnitřního ovzduší v prostředcích pozemní dopravy. Mikrobiální kontaminace byla studována na výstupních a vstupních plochách 5 vzduchových filtrů vyjmutých z klimatizačního systému městských autobusů při pravidelné údržbě. Materiál a metodika: K získání vzorků z výstupní i vstupní strany filtrů byla použita technika suchého stěru. Kultivace byla provedena na různých selektivních nebo selektivně-diagnostických půdách pro kultivaci životaschopných bakterií. K identifikaci bakteriálních druhů bylo použito barvení podle Grama a imerzní mikroskopie. Vybrané kolonie byly rovněž podrobeny proteomické studii. Po identifikaci byly bakterie kvantifikovány. Výsledky: Na vstupním i výstupním povrchu filtrů převažovaly bakterie rodu Bacillus – Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus. Identifikovány byli také bakterie rodů Staphylococcus, Brevibacillus, Peribacillus a Paenibacillus. Kvantifikace ukázala nízkou kontaminaci výstupních povrchů filtrů 1 a 2. Kontaminace vstupní a výstupní strany filtrů 3, 4 a 5 a odhalila téměř stejnou kontaminaci vstupních a výstupních ploch. Závěry: Podle nalezených výsledků doporučujeme buď častější výměnu filtrů, nebo volbu filtrů s nižší porozitou.

The use of HVAC in urban buses in developed countries increases the comfort and indoor air quality in the means of ground transportation. The microbial contamination was studied on outlet and inlet surfaces of 5 air filters removed from the urban buses HVAC during regular maintenance. To acquire samples from both the outlet and the inlet sides of the filters, dry swabbing technique was used. Cultivation was performed on different selective or selective-diagnostic agars, to cultivate viable bacteria. To identify the bacterial species, Gram stain and immerse microscopy was used. Selected colonies underwent the proteomic study (MALDI-TOF) as well. After identification, bacteria were quantified. The bacteria of the genus Bacillus – Bacillus cereus, Bacillus subtilis, Bacillus licheniformis, Bacillus pumilus, Bacillus flexus prevailed on both inlet and outlet surfaces of the filters. The members of genera Staphylococcus, Brevibacillus, Peribacillus or Paenibacillus were also identified. The quantification of colony forming units showed low contamination of the outlet surfaces of filters 1 and 2. The contamination of inlet and outlet sides of filters 3, 4, and 5 was comparable, revealed nearly the same contamination of inlet and outlet surfaces. In the case of filters 3, 4 and 5 we recommend more frequent filter changing or more efficient filter choice.

• MeSH
• Bacillus patogenita   MeSH
• doprava * MeSH
• klimatizace * škodlivé účinky   MeSH
• lidé MeSH
• Staphylococcus patogenita   MeSH
• vzduchové filtry MeSH
• zdraví ve městech MeSH
• znečištění ovzduší * MeSH
• Check Tag
• lidé MeSH

This paper is focused on the design, implementation and verification of a novel method for the optimization of the control parameters of different hybrid systems used for non-invasive fetal electrocardiogram (fECG) extraction. The tested hybrid systems consist of two different blocks, first for maternal component estimation and second, so-called adaptive block, for maternal component suppression by means of an adaptive algorithm (AA). Herein, we tested and optimized four different AAs: Adaptive Linear Neuron (ADALINE), Standard Least Mean Squares (LMS), Sign-Error LMS, Standard Recursive Least Squares (RLS), and Fast Transversal Filter (FTF). The main criterion for optimal parameter selection was the F1 parameter. We conducted experiments using real signals from publicly available databases and those acquired by our own measurements. Our optimization method enabled us to find the corresponding optimal settings for individual adaptive block of all tested hybrid systems which improves achieved results. These improvements in turn could lead to a more accurate fetal heart rate monitoring and detection of fetal hypoxia. Consequently, our approach could offer the potential to be used in clinical practice to find optimal adaptive filter settings for extracting high quality fetal ECG signals for further processing and analysis, opening new diagnostic possibilities of non-invasive fetal electrocardiography.

• MeSH
• algoritmy MeSH
• elektrokardiografie * metody   MeSH
• lidé MeSH
• metoda nejmenších čtverců MeSH
• monitorování plodu metody   MeSH
• plod fyziologie   MeSH
• počítačové zpracování signálu * MeSH
• těhotenství MeSH
• Check Tag
• lidé MeSH
• těhotenství MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

• MeSH
• filtrace MeSH
• látky znečišťující vzduch v pracovním prostředí analýza   MeSH
• mikroskopie fázově kontrastní MeSH
• monitorování životního prostředí metody   MeSH

• Konspekt
• Lékařské vědy. Lékařství
• NLK Obory
• environmentální vědy
• pracovní lékařství
• technika lékařská, zdravotnický materiál a protetika
• environmentální vědy
• NLK Publikační typ
• publikace WHO

Portable household air purifiers are widely used devices designed to maintain a high-quality level of indoor air. Portable air purifiers equipped with the high-efficiency air (HEPA) filter served 100 h in a household space occupied by two adults without any symptoms of respiratory tract infection. The main objective of the study was to determine microbial contamination on the HEPA filter and to investigate if the selected nanotextile monolayer made of polyamide 6 (PA6) nanofibers can capture potential microorganisms when installed downstream of the HEPA filter as the final filtration medium. Samples were taken from the inlet and outlet surfaces. Samples from the nanotextile were collected in the same manner as from the HEPA filter. QIAStat DX® 1.0 Analyzer using the Respiratory SARS CoV-2 Panel multiplex PCR detection system was selected for microorganism detection. Adenovirus was detected on the inlet surface of the HEPA filter. The outlet surface of the filter contained no viruses included in the Respiratory SARS CoV-2 Panel portfolio. The nanotextile monolayer was replaced twice during the 100 h of operation, so three pieces were used and all contained coronavirus 229 E. Coronavirus 229 E was then detected in the nasopharynx of one of the members of the household as well. It may be assumed that the selected nanotextile is capable of capturing a virus of a small size.

• MeSH
• filtrace MeSH
• lidé MeSH
• pilotní projekty MeSH
• SARS-CoV-2 MeSH
• syndrom akutního respiračního selhání * MeSH
• vzduchové filtry * MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH

• MeSH
• algoritmy MeSH
• elektrokardiografie MeSH
• kardiopulmonální resuscitace MeSH
• počítačová simulace MeSH
• počítačové zpracování signálu MeSH

• Klíčová slova
• kavální filtr, sdružená operace,
• MeSH
• chirurgie operační * metody   MeSH
• kavální filtry využití   MeSH
• laparoskopie MeSH
• lidé MeSH
• metastázy nádorů MeSH
• nádory ledvin * chirurgie   MeSH
• nefrektomie MeSH
• trombóza chirurgie   komplikace   MeSH
• vena cava inferior chirurgie   MeSH
• výběr pacientů MeSH
• Check Tag
• lidé MeSH