Effect of Catheter-Based Patent Foramen Ovale Closure on the Occurrence of Arterial Bubbles in Scuba Divers

ObjectivesThis study sought to evaluate the effect of catheter-based patent foramen ovale (PFO) closure on the occurrence of arterial bubbles after simulated dives.BackgroundPFO is a risk factor of decompression sickness in divers due to paradoxical embolization of bubbles. To date, the effectiveness of catheter-based PFO closure in the reduction of arterial bubbles has not been demonstrated.MethodsA total of 47 divers (age 35.4 ± 8.6 years, 81% men) with a PFO (PFO group) or treated with a catheter-based PFO closure (closure group) were enrolled in this case-controlled observational trial. All divers were examined after a simulated dive in a hyperbaric chamber: 34 divers (19 in the PFO group, 15 in the closure group) performed a dive to 18 m for 80 min, and 13 divers (8 in the PFO group, 5 in the closure group) performed a dive to 50 m for 20 min. Within 60 min after surfacing, the presence of venous and arterial bubbles was assessed by transthoracic echocardiography and transcranial color-coded sonography, respectively.ResultsAfter the 18-m dive, venous bubbles were detected in 74% of divers in the PFO group versus 80% in the closure group (p = 1.0), and arterial bubbles were detected in 32% versus 0%, respectively (p = 0.02). After the 50-m dive, venous bubbles were detected in 88% versus 100%, respectively (p = 1.0), and arterial bubbles were detected in 88% versus 0%, respectively (p < 0.01).ConclusionsNo difference was observed in the occurrence of venous bubbles between the PFO and closure groups, but the catheter-based PFO closure led to complete elimination of arterial bubbles after simulated dives. (Nitrogen Bubble Detection After Simulated Dives in Divers With PFO and After PFO Closure; NCT01854281

Monitoring of Dips and Deformations of the Gas Pipeline in the Area Affected by Mining Activities in the Locality Životice - Karviná

Tato diplomová práce pojednává o činnostech spjatých se sledováním posunů a deformací na kompenzátorech plynovodu, který se nachází na poddolovaném území. Skládá se z pěti kapitol, ve kterých jsou postupně rozebrány pohyby hornin vlivem poddolování, měření posunů a deformací, kompenzátory a jejich bodová pole, polohopisné a výškopisné zaměření podrobných bodů a tvorba dokumentace a porovnání s předchozími etapami měření. První polovina práce je spíše teoretická, ve druhé polovině jsou popsány činnosti, které proběhly během měření prakticky.This thesis is about activities related to monitoring of dips and deformations on gas pipeline compensators which are located in undermined area. It consists of five chapters, in which are described rock movements due to undermining, measuring of dips and deformations, compensators and their point field, topography and altimetry measuring of the particular points and making of documentation and comparison with previous measurings. First half of the thesis is more theoretical, in the second half are described all the activities, which happend during measuring practically.544 - Katedra geodézie a důlního měřictvívýborn

Úloha foramen ovale patens v patofyziologii vzniku dekompresní choroby.

Foramen ovale patens (PFO) je spojováno se zvýšeným rizikem vzniku dekompresní choroby potápěčů (DCS). Patofyziologicky je tento jev vysvětlován paradoxní embolizací dusíkových bublin do systémového oběhu s následnou obturací kapilár vedoucí k ischemickému poškození tkání. Tato hypotéza, ač vyslovena již v 80. letech 20. století, je stále diskutována a doposud chyběla experimentální a prospektivní klinická data, která by ji podporovala. Její význam přitom není zdaleka jen teoretický. Průkaz PFO jako etiologického faktoru vzniku DCS a zejména nevyprovokované DCS (bez porušení dekompresních pravidel), by mělo zásadní význam i v terapii a prevenci této choroby, která představuje potenciální riziko pro miliony potápěčů na celém světě. V našem výzkumu si klademe za cíl ozřejmit úlohu PFO v patofyziologii vzniku DCS a zjistit, zda prevence paradoxní embolizace dusíkových bubIin, povede k snížení incidence nevyprovokované DCS. Provedli jsme screening přítomnosti PFO pomocí transkraniální duplexní ultrasonografie u 489 potápěčů. V retrospektivní analýze jsme zjistili, že incidence nevyprovokované DCS byla 7% a že PFO bylo jediným rizikovým faktorem. V dalším výzkumu jsme se zaměřili na detekci venózních a arteriálních dusíkových bublin po simulovaných ponorech v hyperbarické komoře. Zjistili jsme, že ponory...Patent foramen ovale (PFO) has been associated with an increased risk of decompression sickness (DCS) in divers. Pathophysiologicaly this has been ascribed to paradoxical embolization of nitrogen bubbles from venous blood to systemic circulation, resulting in obstruction of peripheral capillaries and ischemic injury. However, the role of PFO has been largely debated and experimental and prospective clinical data has been missing. It is of note, that this hypothesis is not only of theoretical importance. The proof of PFO as a causative factor of DCS and, importantly, of unpredictable events (unprovoked DCS) could affect millions of divers worldwide through improved therapy and prevention. In our research we aimed to describe the pathophysiological role of PFO in decompression sickness and to determine whether the prevention of arterialization of post-dive venous gas emboli (VGE) would decrease the incidence of unprovoked DCS in divers. We have screened 489 scuba divers for the presence of PFO by means of transcranial color-coded Doppler ultrasonography. In a retrospective analysis we found that the incidence of unprovoked decompression sickness was 7% among these divers and that PFO was the only risk factor. Subsequently, we have studied the occurrence of VGE and arterial gas emboli (AGE) in divers with...Ústav patologické fyziologie 1. LF UK v PrazeInstitute of Pathological Physiology First Faculty of Medicine Charles University in PragueFirst Faculty of Medicine1. lékařská fakult

Prostorové modelování báze dubňanské sloje v moravské ústřední prohlubni (česká část Vídeňské pánve)

This paper deals with the methodology of modelling the Dubňany lignite seam base and its tectonic failure. Tectonic pattern of the Vienna Basin has been subject of many studies. Opinions on its origin have been developing. Coal seams in the South Moravian Lignite Coalfield were modelled under the project of the example modern evaluation of the coal deposit. Designed software with application of modern mathematical, statistical and geostatistical methods and SURFER program were used for coal seam modelling. Input data were taken from detailed mining, deposit and well exploration carried out for more than 50 years.Příspěvek je věnován metodice digitálního modelování báze dubňanské lignitové sloje a jejího tektonického porušení. Tektonická stavba vídeňské pánve je předmětem mnoha studií a názory na její genezi se stále vyvíjejí. Podrobné modelování slojí jihomoravského lignitového revíru bylo provedeno v rámci vzorového komplexního hodnocení uhelného ložiska v prostředí programu SURFER a pomocí účelově sestaveného programového systému s využitím moderních matematických, statistických a geostatistických metod. Vstupní data tvořily údaje o sloji a jejím okolí získané v minulosti během více než padesátiletého podrobného důlního, ložiskového a vrtného průzkumu

Characterization of two low-charge vermiculites after hydrochloric acid treatment

Two natural vermiculites (Ver) with very similar chemical composition but slightly different low charge on the layers were investigated to find an answer the question, how to change their structural and chemical properties after exposure to different concentrations of HCl solutions. Vermiculite from Bulgaria (Ver-B) with the layer charge 0.47 eq/O10(OH)2 and from Brazil (Ver-SL) with the layer charge 0.36 eq/O10(OH)2 were studied on their particle size fraction less than 40 μm after treatment at different HCl concentrations (0.5 M HCl and 1 M HCl). Both samples represent a mixed-layer structure after incomplete transformation of mica (biotite) to vermiculite. Based on the XRD patterns, Ver-B may be considered as the mixed-layer vermiculite interstratified with small proportion of mica layers and Ver-SL as the mixed-layer mica-vermiculite. The leaching with 0.5 M HCl increased SA of Ver-B from 29.5 m2.g-1 to 261 m2.g-1 at Ver-B05 in comparison with the SA of Ver-SL from 14.0 m2.g-1 to 191 m2.g-1 in Ver-SL05. It can be assumed that the acidification was more effective to: (1) leaching of Mg2+ cations at incomplete vermiculated sample Ver-SL and (2) Fe2+and Fe3+ from octahedra and Al3+ from the tetrahedra at vermiculite sample Ver-B and (3) increasing SA at Ver-B.Web of Science12330629

Polyvinyl nanocomposites with carbon particles for membrane

Import 02/11/2016Tato diplomová práce je zaměřena na optimalizaci přípravy a charakterizaci nanokompozitních filmů typu polymer/uhlíkaté plnivo. Práce obsahuje teoretickou a praktickou část. Teoretická část se věnuje vlastnostem a použití polymeru (polyvinylacetátu) a~uhlíkatých nanoplniv (nanovlákna, nanotrubičky a grafenové vrstvy). Praktická část se věnuje přípravě nanokompozitních filmů typu polyvinylacetát/uhlíkaté plnivo, jejich charakterizaci pomocí skenovací elektronové mikroskopie, mikroskopie atomárních sil, rentgenové difrakční analýzy a světelné mikroskopie. Cílem bylo připravit a~charakterizovat nanokompozitní film sestávající z~různých uhlíkatých nanoplniv.This master's is focused on optimizing the preparation and characterization of nanocomposite films based on polymer/carbon filler. The thesis contains theoretical and practical part. The theoretical part describes properties and use of polymer (polyvinyl acetate) and carbon nanofillers (nanofibers, nanotubes and graphene sheets). The practical part deals with preparation of nanocomposite films based on polyvinyl acetate/carbon filler, their characterization by electron scanning microscopy, atomic force microscopy, x-ray diffraction analysis and light microscopy. The aim of this work was to obtain and characterise nanocomposite film composed of various carbon nanofillers.9360 - Centrum nanotechnologiívýborn

Rate of development of predatory insects is dependent on that of their prey

In this study we analyzed data in the literature on the rates of development of parasitoids that parasitize aphids and coccids. The objective was to determine whether their rates of development, as is well documented for ladybirds, are also dependent on that of their prey. The analysis revealed that, like ladybirds, parasitoids that parasitize aphids develop faster than those that parasitize coccids. Parasitoids and ladybird predators show the same pattern in their rates of development: those attacking aphids develop faster than those attacking coccids. This is strong evidence that we are dealing with a general response rather than one specific to ladybirds. It also lends support to the concept that the development rates of these natural enemies are evolutionarily conserved rather than phylogenetically constrained

Can native geographical range, dispersal ability and development rates predict the successful establishment of alien ladybird (Coleoptera: Coccinellidae) species in Europe?

A list of alien ladybird (Coleoptera: Coccinellidae) species to Europe was prepared and the history and circumstances of their introductions were determined. Currently there are twelve alien ladybird species in Europe, originating from Australian, Oriental, Nearctic, Palearctic and Afrotropical regions. All of the species were intentionally released as biological control agents and most are coccidophagous species. The aphidophagous Harmonia axyridis is the only ladybird regarded as invasive in Europe. The main factors leading to successful establishment were food relationship, living in different habitats in different geographical regions and geographic origin. We found that successful invaders, in their native areas, showed adaptability to a wide range of conditions compared to non-invasive species. Larger aphidophagous alien ladybirds were found to develop as fast as native species. Characteristics that did not differ between native and alien species are thermal requirements for development, fecundity and body size. However, unlike other alien ladybirds, H. axyridis had higher potential dispersal ability

The Invasive Box Tree Moth Five Years after Introduction in Slovakia: Damage Risk to Box Trees in Urban Habitats

The box tree moth Cydalima perspectalis (Walker, 1859) (Lepidoptera: Crambidae) is an invasive species in Europe and a serious pest of box trees (Buxus spp.). In Slovakia, Central Europe, it was first reported in 2012 within the low elevation region with a warm climate. We hypothesize that the cold mountain region of Slovakia would provide less suitable conditions for the spread of this species, indicated by no or only slight damage to box trees. Five years after C. perspectalis was first recorded in Slovakia, we assessed the probability of occurrence of the moth and the probability of damage to box trees (Buxus sempervirens) by its larvae, using temperature and altitude data as predictors. In June and July 2017, at 156 locations (towns and villages) between the altitudes of 109 and 888 m, we recorded damage and categorized the intensity of damage to box trees by C. perspectalis using a four-point scale. Box trees infested by C. perspectalis were recorded in most locations at altitudes between 110 and 400 m with the mean annual temperature varying between 10.5 and 7.9 °C. High damage to box trees was found in locations up to 340 m a.s.l. characterized by mean annual temperatures above 8.5 °C. Our results suggested high probability (>60%) of any damage to box trees for the area up to approximately 300 m a.s.l. (mean annual temperature above 8.4 °C), and high probability (>60%) of high damage for the area up to approximately 250 m a.s.l. (mean annual temperature above 9 °C). The area where damage to box trees was predicted using the altitude showed great overlap with the area predicted using the mean annual temperature. The area with the probability of any damage was only slightly larger than the area with the probability of high damage

Antagonistic interactions between an invasive alien and a native coccinellid species may promote coexistence

1. Despite the capacity of invasive alien species to alter ecosystems, the mechanisms underlying their impact remain only partly understood. Invasive alien predators, for example, can significantly disrupt recipient communities by consuming prey species or acting as an intraguild predator (IGP). 2. Behavioural interactions are key components of interspecific competition between predators,yet these are often overlooked invasion processes. Here, we show how behavioural, nonlethal IGP interactions might facilitate the establishment success of an invading alien species. 3. We experimentally assessed changes in feeding behaviour (prey preference and consumption rate) of native UK coccinellid species (Adalia bipunctata and Coccinella septempunctata),whose populations are, respectively, declining and stable, when exposed to the invasive intraguild predator, Harmonia axyridis. Using a population dynamics model parameterized with these experimental data, we predicted how intraguild predation, accommodating interspecific behavioural interactions, might impact the abundance of the native and invasive alien species over time. 4. When competing for the same aphid resource, the feeding rate of A. bipunctata significantly increased compared to the feeding in isolation, while the feeding rate of H. axyridis significantly decreased. This suggests that despite significant declines in the UK, A. bipunctata is a superior competitor to the intraguild predator H. axyridis. In contrast, the behaviour of non-declining C. septempunctata was unaltered by the presence of H. axyridis. 5. Our experimental data show the differential behavioural plasticity of competing native and invasive alien predators, but do not explain A. bipunctata declines observed in the UK. Using behavioural plasticity as a parameter in a population dynamic model for A. bipunctata and H. axyridis, coexistence is predicted between the native and invasive alien following an initial period of decline in the native species. We demonstrate how empirical and theoretical techniques can be combined to understand better the processes and consequences of alien species invasions for native biodiversity