A randomized controlled trial to evaluate utilization of physical activity recommendations among patients of cardiovascular healthcare centres in Eastern Slovakia:study design and rationale of the AWATAR study

BACKGROUND: Guidelines on modifiable risk factors regarding cardiological patients are poorly implemented in clinical practice perhaps due to low health literacy. Several digital tools for improving lifestyle and behavioural intervention were developed. Our primary aim is to evaluate the effectiveness of a digital exercise prescription tool on the adherence to physical activity recommendations among patients with cardiovascular diseases. METHODS: A randomized controlled trial will be realized in cooperation with Cardiovascular Health Centres in Eastern Slovakia. Patients recruited through their cardiologists, will be randomised at 1:1 ratio to the three-months' experimental condition or control condition. The experimental group will receive standard lifestyle consultation leading to individually optimized prescription of physical activity. The control group will receive standard, usual-cardio-care lifestyle counselling, also in the domain of physical activity. The digital system will be used for optimized exercise prescription. The primary outcome is a change in the patient's adherence to exercise recommendations. Data will be collected in both groups prior to consultation and after 3 months. DISCUSSION: This study protocol presents background and design of a randomized control trial to investigate the effectiveness of a digital system-provide exercise prescription tool on the adherence to physical activity recommendations. An optimized exercise prescription that better reflects patient's diagnosis, comorbidities and medication can have a significant impact on secondary prevention of cardiovascular disease. This trial can provide important evidence about the effectiveness of digital exercise guidance in everyday practice of cardiovascular healthcare. TRIAL REGISTRATION: The study was registered on 1st November, 2017 and is available online at ClinicalTrials.gov (ID: NCT03329053 )

Roots alterations in presence of phenanthrene may limit co-remediation implementation with Noccaea caerulescens

Co-phytoremediation of both trace elements and polycyclic aromatic hydrocarbons (PAH) is an emerging technique to treat multi-contaminated soils. In this study, root morphological and structural features of the heavy metal hyperaccumulator Noccaea caerulescens, exposed to a model PAH phenanthrene (PHE) in combination with cadmium (Cd), were observed. In vitro cultivated seedlings were exposed to 2 mM of PHE and/or 5 mu M of Cd for 1 week. Co-phytoremediation effectiveness appeared restricted because of a serious inhibition (about 40%) of root and shoot biomass production in presence of PHE, while Cd had no significant adverse effect on these parameters. The most striking effects of PHE on roots were a decreased average root diameter, the inhibition of cell and root hair elongation and the promotion of lateral root formation. Moreover, endodermal cells with suberin lamellae appeared closer to the root apex when exposed to PHE compared to control and Cd treatments, possibly due to modified lateral root formation. The stage with well-developed suberin lamellae was not influenced by PHE whereas peri-endodermal layer development was impaired in PHE-treated plants. Many of these symptoms were similar to a water-deficit response. These morphological and structural root modifications in response to PHE exposition might in turn limit Cd phytoextraction by N. caerulescens in co-contaminated soils

Relationship between root structure and root cadmium uptake in maize

A clear description of the mechanism of root cadmium absorption is required in order to understand how this toxic metal is phytoaccumulated. An experiment was carried out in order to test the hypotheses that (1) the Cd uptake is higher for maize roots grown in hydroponics than for those grown in aeroponics, (2) this difference is due to the fact that in aeroponics, root apoplastic barriers are developed more extensively than in hydroponics and (3) the structure of maize roots grown in aeroponics is closer to the structure of roots grown in soil. Apoplastic and symplastic cadmium uptake was measured by exposing the roots to a radio-labelled Cd solution and by the physical fractionation of the metal in the roots. Maturation of the exodermis and endodermis as well as their distance from the root tip were assessed through fluorescent staining and microscopy of successive sections along the main root. The results obtained support the initial hypotheses. Both symplastic absorption and apoplastic adsorption of Cd were higher for maize roots grown in hydroponics than in aeroponics. This can be explained by the fact that the beginning of the barrier formation took place on average at a distance of 12.46% of the root length from its tip, while in aeroponics, root apoplastic barriers developed much earlier, at 2.72% of the root length. Since the characteristics of maize plants roots cultivated in aeroponics were much closer to those cultivated in soil, their kinetic parameters may be considered to be more representative when measuring uptake than those of hydroponically grown plants

Effect and localization of phenanthrene in maize roots

International audiencePolycyclic aromatic hydrocarbons (PAHs) have a toxic effect on plants, which limits the efficiency of phytomanagement of contaminated soils. The mechanisms underlying their toxicity are not fully understood. A cultivation experiment was carried out with maize, used as model plant, exposed to sand spiked with phenanthrene (50 or 150 mg kg(-1) dw). Epi-fluorescence microscopic observation of root sections was used to assess suberization of exodermis and endodermis and phenanthrene localization along the primary root length. For 10 days of cultivation, exodermis and endodermis suberization of exposed maize was more extensive. However, after 20 days of exposure, exodermis and endodermis of non-exposed roots were totally suberized, whilst PHE-exposed roots where less suberized. Early extensive suberization may act as barrier against PHE penetration, however longer exposure inhibits root maturation. Phenanthrene patches were located only near suberized exodermis and endodermis, which may therefore act as retention zones, where the hydrophobic phenanthrene accumulates during its radial transport

Effect of phenanthrene exposure on apoplastic barriers formation in maize

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