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.
Long-term peritoneal dialysis is associated with the development of peritoneal membrane alterations, both in morphology and function. Impaired ultrafiltration (UF) is the most important functional change, and peritoneal fibrosis is the major morphological alteration. Both are caused by the continuous exposure to dialysis solutions that are different from plasma water with regard to the buffer substance and the extremely high-glucose concentrations. Glucose has been incriminated as the major cause of long-term peritoneal membrane changes, but the precise mechanism has not been identified. We argue that glucose causes the membrane alterations by peritoneal pseudohypoxia and by the formation of advanced glycosylation end products (AGEs). After a summary of UF kinetics including the role of glucose transporters (GLUT), and a discussion on morphologic alterations, relationships between function and morphology and a survey of the pathogenesis of UF failure (UFF), it will be argued that impaired UF is partly caused by a reduction in small pore fluid transport as a consequence of AGE-related vasculopathy and - more importantly - in diminished free water transport due to pseudohypoxia, caused by increased peritoneal cellular expression of GLUT-1. The metabolism of intracellular glucose will be reviewed. This occurs in the glycolysis and in the polyol/sorbitol pathway, the latter is activated in case of a large supply. In both pathways the ratio between the reduced and oxidised form of nicotinamide dinucleotide (NADH/NAD+ ratio) will increase, especially because normal compensatory mechanisms may be impaired, and activate expression of hypoxia-inducible factor-1 (HIF-1). The latter gene activates various profibrotic factors and GLUT-1. Besides replacement of glucose as an osmotic agent, medical treatment/prevention is currently limited to tamoxifen and possibly Renin/angiotensis/aldosteron (RAA) inhibitors.
- MeSH
- Dialysis Solutions adverse effects metabolism MeSH
- Glucose adverse effects metabolism MeSH
- Glycosylation MeSH
- Humans MeSH
- Peritoneal Dialysis * adverse effects MeSH
- Peritoneum metabolism MeSH
- Ultrafiltration MeSH
- Water metabolism MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
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
- Filtration MeSH
- Humans MeSH
- Pilot Projects MeSH
- SARS-CoV-2 MeSH
- Severe Acute Respiratory Syndrome * MeSH
- Air Filters * MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
In this study, we investigated the clinical effects of blood ultrafiltration therapy in patients with acute decompensated chronic heart failure. We enrolled 78 patients with acute decompensated chronic heart failure who were admitted to a hospital from September 2017 to December 2021, and divided them into two groups based on the digital randomization method. The FQ-16 heart failure ultrafiltration dehydrating device blood ultrafiltration therapy was administered to the observation group (39 patients) for 8-16 hours, while the control group (39 patients) received the stepped drug therapy. Echocardiography was used to assess the changes in cardiac function of the patients in both groups before and after treatment. The changes in urine volume, N-terminal pro-B-type natriuretic peptide (NT-proBNP), plasma renin, and serum creatinine levels were measured before and after the treatment to compare the overall response rate of the patients in both groups. The differences in left ventricular end-systolic dimension and left ventricular end-diastolic dimension and the ejection fraction between the groups before treatment were not statistically significant (P > 0.05), however, the left ventricular end-diastolic dimension in the observation group was significantly lower and the ejection fraction was significantly higher (P < 0.05) compared with that before treatment; the urine volume, N-terminal pro-B-type natriuretic peptide (NT-proBNP), plasma renin, and serum creatinine were significantly improved in both groups after treatment compared with that before treatment. All indexes in the observation group were better than those in the control group (P < 0.05), 74.36%. The overall response rate of the observation group was 94.87%, x2 = 4.843 and the difference between groups was statistically significant (P < 0.05). Blood ultrafiltration therapy for patients with acute decompensated chronic heart failure can improve their cardiac and renal functions, reduce NT-proBNP, reduce volume load, and enhance efficacy while ensuring high safety.
- MeSH
- Biomarkers MeSH
- Diuretics therapeutic use MeSH
- Ventricular Function, Left physiology MeSH
- Creatinine MeSH
- Humans MeSH
- Natriuretic Peptide, Brain * MeSH
- Peptide Fragments MeSH
- Renin MeSH
- Heart Failure * MeSH
- Stroke Volume physiology MeSH
- Ultrafiltration MeSH
- Treatment Outcome MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article 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
- Aerosols MeSH
- COVID-19 * prevention & control MeSH
- Equipment Design MeSH
- Filtration methods MeSH
- Humans MeSH
- Masks MeSH
- Polyesters MeSH
- Respiratory Protective Devices * MeSH
- Materials Testing methods MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
Hyaluronan (HA) is widely used for eye drops as lubricant to counteract dry eye disease. High and low molecular weight HA are currently used in ophthalmology. However, a large portion of the current literature on friction and lubrication addresses articular (joint) cartilage. Therefore, eye drops compositions based on HA and its derivatized forms are extensively characterized providing data on the tribological and mucoadhesive properties. The physiochemical properties are investigated in buffers used commonly in eye drops formulations. The tribological investigation reveals that amphiphilic HA-C12 decreases the friction coefficient. At the same time, the combination of trehalose/HA or HAC12 enhances up to eighty-fold the mucoadhesiveness. Thus, it is predicted a prolonged residence time on the surface of the eye. The incorporation of trehalose enhances the protection of human keratinocytes (HaCaT) cells, as demonstrated in an in-vitro cell-desiccation model. The presence of trehalose increases the friction coefficient. Medium molecular weight HA shows significantly lower friction coefficient than high molecular weight HA. This research represents a first, wide array of features of diverse HA forms for eye drops contributing to increase the knowledge of these preparations. The results here presented also provide valuable information for the design of highly performing HA-formulations addressing specific needs before preclinic.
- MeSH
- Adhesiveness MeSH
- HaCaT Cells MeSH
- Filtration MeSH
- Mucus drug effects MeSH
- Hyaluronic Acid chemical synthesis chemistry pharmacology MeSH
- Drug Delivery Systems * MeSH
- Humans MeSH
- Lubrication * MeSH
- Nephelometry and Turbidimetry MeSH
- Eye drug effects MeSH
- Ophthalmic Solutions pharmacology MeSH
- Proton Magnetic Resonance Spectroscopy MeSH
- Rheology MeSH
- Sterilization MeSH
- Friction MeSH
- Viscosity MeSH
- Desiccation MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Research Support, Non-U.S. Gov't MeSH
39 stran : ilustrace, tabulky ; 30 cm
Směrnice ISO, které se zaměřují na filtraci a použití vyčištěné šedé a srážkové vody v budovách.
- MeSH
- Housing MeSH
- Rain MeSH
- Filtration MeSH
- Water Quality MeSH
- Wastewater MeSH
- Recycling MeSH
- Water standards MeSH
- Water Supply MeSH
- Publication type
- Guideline MeSH
- Conspectus
- Metrologie. Standardizace
- NML Fields
- environmentální vědy
- technika
30 stran : ilustrace, tabulky ; 30 cm
Směrnice ISO, které se zaměřují na filtraci a použití vyčištěné šedé vody v budovách.
- MeSH
- Housing MeSH
- Filtration MeSH
- Water Quality MeSH
- Wastewater MeSH
- Recycling MeSH
- Water standards MeSH
- Water Supply MeSH
- Publication type
- Guideline MeSH
- Conspectus
- Metrologie. Standardizace
- NML Fields
- environmentální vědy
- technika
