598 research outputs found

    Cell bystander effect induced by radiofrequency electromagnetic fields and magnetic nanoparticles

    Get PDF
    Induced effects by direct exposure to ionizing radiation (IR) are a central issue in many fields like radiation protection, clinic diagnosis and oncological therapies. Direct irradiation at certain doses induce cell death, but similar effects can also occur in cells no directly exposed to IR, a mechanism known as bystander effect. Non-IR (radiofrequency waves) can induce the death of cells loaded with MNPs in a focused oncological therapy known as magnetic hyperthermia. Indirect mechanisms are also able to induce the death of unloaded MNPs cells. Using in vitro cell models, we found that colocalization of the MNPs at the lysosomes and the non-increase of the temperature induces bystander effect under non-IR. Our results provide a landscape in which bystander effects are a more general mechanism, up to now only observed and clinically used in the field of radiotherapy.Comment: 16 pages, 4 figures, submitted to International Journal of Radiation Biolog

    Application of modulated chlorophyll fluorescence and modulated chlorophyll fluorescence imaging to study the environmental stress effect

    Get PDF
    Chlorophyll (Chl) a fluorescence is a widely used tool to monitor the photosynthetic process in plants subjected to environmental stresses. this review reports the theoretical bases of Chl fluorescence, and the significance of the most important Chl fluorescence parameters. it also reports how these parameters can be utilised to estimate changes in photosystem (Ps) ii photochemistry, linear electron flux and dissipation mechanisms. the relation between actual Psii photochemistry and Co2 assimilation is discussed, as is the role of photochemical and non-photochemical quenching in inducing changes in Psii activity. the application of Chl fluorescence imaging to study heterogeneity on leaf lamina is also considered. this review summarises only some of the results obtained by this methodology to study the effects of different environmental stresses, namely water availability, nutrients, pollutants, temperature and salinity

    Errores conceptuales en los modelos atómicos cuánticos

    Get PDF
    SUMMARY We analyze how the basic concepts about atomic models are introduced into the Spanish educational system. We considered the textbooks most currently used in the educational levels from 8th EGB to the 1st University level. We finally discuss the possible sources of misconceptions

    Magnetic hyperthermia enhances cell toxicity with respect to exogenous heating

    Get PDF
    Magnetic hyperthermia is a new type of cancer treatment designed for overcoming resistance to chemotherapy during the treatment of solid, inaccessible human tumors. The main challenge of this technology is increasing the local tumoral temperature with minimal side effects on the surrounding healthy tissue. This work consists of an in vitro study that compared the effect of hyperthermia in response to the application of exogenous heating (EHT) sources with the corresponding effect produced by magnetic hyperthermia (MHT) at the same target temperatures. Human neuroblastoma SH-SY5Y cells were loaded with magnetic nanoparticles (MNPs) and packed into dense pellets to generate an environment that is crudely similar to that expected in solid micro-tumors, and the above-mentioned protocols were applied to these cells. These experiments showed that for the same target temperatures, MHT induces a decrease in cell viability that is larger than the corresponding EHT, up to a maximum difference of approximately 45% at T = 46 °C. An analysis of the data in terms of temperature efficiency demonstrated that MHT requires an average temperature that is 6 °C lower than that required with EHT to produce a similar cytotoxic effect. An analysis of electron microscopy images of the cells after the EHT and MHT treatments indicated that the enhanced effectiveness observed with MHT is associated with local cell destruction triggered by the magnetic nano-heaters. The present study is an essential step toward the development of innovative adjuvant anti-cancer therapies based on local hyperthermia treatments using magnetic particles as nano-heaters

    Movement representation strategies as a tool for educational innovation in physiotherapy students: a randomized single-blind controlled-pilot trial

    Get PDF
    Physiotherapy has a strictly theoretical body of knowledge, but for the most part, the physiotherapist’s learning is practical. The practical part is fundamental to acquire clinical skills that the physiotherapist will later use in professional practice. The main aim of this study was to assess the effectiveness of movement representation strategies (MRS) in the improvement of manual skills of physiotherapy students as an educational innovation strategy. We randomly assigned 30 participants to an action observation practice (AOP), motor imagery practice (MIP), or sham observation (SO) group. A high velocity, low amplitude lumbar manipulation technique that is widely used in clinical physiotherapy practice was taught in one session. The primary outcomes were required time and test score. The secondary outcomes were perceived mental fatigue and perceived difficulty for learning. The outcomes were assessed preintervention and immediately after the intervention (postintervention). The main results showed that both AOP and MIP improved the total time required and the test score, as well as entailed less perceived difficulty for learning. However, both strategies showed a higher level of mental fatigue after the intervention, which was higher in the MIP group. Based on the results obtained, it seems that the application of MRS promotes greater learning of manual motor tasks in physiotherapy students and could be used as educational innovation strategies

    Nurses' protocol-based care decision-making: a multiple case study

    Get PDF
    Aim: To describe and explain nurses' protocol-based care decision-making. Background: Protocol-based care is a strategy to reduce variability in clinical practice. There are no studies looking at protocol-based care decision-making. Understand this process is key to successful implementation. Method: A multiple embedded case study was carried out. Nurses' protocol-based care decision-making was studied in three inpatient wards (medical, surgical and medical-surgical) of a university hospital in northern Spain. Data collection was performed between 2015 and 2016 including documentary analysis, non-participant observations, participant observations and interviews. Analysis of quantitative data involved descriptive statistics and qualitative data was submitted to Burnard's method of content analysis (1996). The data integration comprised the integration of the data set of each case separately and the integration of the findings resulting from the comparison of the cases. The following the thread method of data integration was used for this purpose. The SRQR guideline was used for reporting. Results: The multiple embedded case study revealed protocol-based care decision-making as a linear and variable process that depends on the context and consists of multiple interrelated elements, among which the risk perception is foremost. Conclusion: This study has allowed progress in protocol-based care decision-making characterisation. This knowledge is crucial to support the design of educational and management strategies aimed at implementing protocol-based care. Relevance to clinical practice: Strategies to promote protocol-based care should address the contexts of practice and the ability of professionals' to accurately assess the degree of risk of clinical activity. Hence, it will promote quality of care, patient safety and efficiency in healthcare cost
    • …
    corecore