Interparticle interaction effect on magnetization dynamics of multicore iron oxide particles in alternating magnetic field

Magnetic multicore iron oxide particles are nowadays intensively studied for application in magnetic hyperthermia. These particles compose of superparamagnetic iron oxide cores densely packed due to magnetic interactions. The magnetic interaction leads to the increase of energy barrier of magnetization reversal and therefore the heating losses in alternating magnetic field can be enhanced. However, the magnetization dynamics of such systems in alternating magnetic field remains still unclear. Apparently, the main parameters influencing the interaction with magnetic field are the morphology of single cores and multicore particles as well as the intercore and interparticle magnetic interactions. In the current work, we investigate the effect of interparticle interactions between the multicore particles on the heating efficiency of magnetic dispersions in alternating magnetic field. Two types of multicore particles were prepared: naked multicore particles displaying dipole-dipole interactions and multicore particles with surface coating preventing the interaction of multicores. Both types of multicore particles were composed of 13 nm iron oxide cores and have the hydrodynamic size of about 85 nm. To study the absorption of AMF energy, multicore particles were dispersed in media with different viscosity (water and agarose). It was demonstrated that covered multicore particles display significantly higher heating efficiency in both media than naked particles, which is associated with the elimination of dipole-dipole interaction between multicores.ERDF, European Regional Development FundMinistry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504]; Operational Program Research and Development for Innovations - European Regional Development Fund (ERDF); national budget of the Czech Republic [CZ.1.05/2.1.00/19.0409

Magneto-responsive hyaluronan hydrogel for hyperthermia and bioprinting: Magnetic, rheological properties and biocompatibility

Magneto-responsive soft hydrogels are used for a number of biomedical applications, e.g., magnetic hyperthermia, drug delivery, tissue engineering, and neuromodulation. In this work, this type of hydrogel has been fabricated from hyaluronan (HA) filled with a binary system of Al2O3 nanoparticles and multicore magnetic particles (MCPs), which were obtained by clustering of superparamagnetic iron oxide FeOx NPs. It was established that the presence of diamagnetic Al2O3 has several positive effects: it enhances the hydrogel storage modulus and long-term stability in the cell cultivation medium; prevents the magnetic interaction among the MCPs. The HA hydrogel provides rapid heating of 0.3 °C per min under exposure to low amplitude radio frequency alternating magnetic field. Furthermore, the magneto-responsive hydrogel was successfully used to encapsulate cells and extrusion-based 3D printing with 87±6% cell viability, thus providing a bio-ink. The combination of high heating efficiency, softness, cytocompatibility, and 3D printability of magnetic HA hydrogel leads to a material suitable for biomedical applications.DKRVO, (RP/CPS/2022/003, RP/CPS/2022/005); Program Multilateral Scientific and Technological Cooperation in the Danube Region, (8X20041); Tomas Bata University in Zlin, TBU, (22–33307S, CZ.02.2.69/0.0/0.0/19_073/0016941, IGA/FT/2023/006); Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT; Grantová Agentura České Republiky, GA ČR, (RP/CPS/2022/001)Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/003, RP/CPS/2022/005]; Program Multilateral Scientific and Technological Cooperation in the Danube Region [8X20041]; TBU [IGA/FT/2023/006]; Czech Science Foundation [22-33307S]; Ministry of Education, Youth and Sports of the Czech Republic [RP/CPS/2022/001

The fingerprint of the summer 2018 drought in Europe on ground-based atmospheric CO2 measurements

During the summer of 2018, a widespread drought developed over Northern and Central Europe. The increase in temperature and the reduction of soil moisture have influenced carbon dioxide (CO2) exchange between the atmosphere and terrestrial ecosystems in various ways, such as a reduction of photosynthesis, changes in ecosystem respiration, or allowing more frequent fires. In this study, we characterize the resulting perturbation of the atmospheric CO2 seasonal cycles. 2018 has a good coverage of European regions affected by drought, allowing the investigation of how ecosystem flux anomalies impacted spatial CO2 gradients between stations. This density of stations is unprecedented compared to previous drought events in 2003 and 2015, particularly thanks to the deployment of the Integrated Carbon Observation System (ICOS) network of atmospheric greenhouse gas monitoring stations in recent years. Seasonal CO2 cycles from 48 European stations were available for 2017 and 2018.The UK sites were funded by the UK Department of Business, Energy and Industrial Strategy (formerly the Department of Energy and Climate Change) through contracts TRN1028/06/2015 and TRN1537/06/2018. The stations at the ClimaDat Network in Spain have received funding from the ‘la Caixa’ Foundation, under agreement 2010-002624

Experience of stigma and discrimination in families of persons with schizophrenia in the Czech Republic

Rationale: Mental health-related stigma and discrimination not only affect persons living with schizophrenia but also their whole families. Stigma and discrimination reduction is key to respond to the unmet needs of persons with mental illness. The local context is of particular importance in this endeavor, as stigma and its manifestations depend on the specific conditions of the target population and across cultures and settings. Evidence on effective approaches to reduce stigma is sparse and lacking from Central and Eastern Europe, including from the Czech Republic. Objective: Our aim was to inform an anti-stigma campaign undertaken in the framework of the national mental health reform in the Czech Republic. Methods: We conducted a qualitative study based on semi-structured in-depth interviews with relatives of patients diagnosed with schizophrenia in the Czech Republic. Initial respondents were identified through local mental health services and users’ organizations with a consecutive chain-referral sampling. Transcribed narratives were thematically analyzed within a pre-developed four-level thematic framework to comprehensively identify experiences of stigma and discrimination in all areas of the respondents’ lives. Results: Stigma experiences of 25 diverse family members of persons living with schizophrenia spanned four levels of respondents’ lives (macro-, meso-, micro-, and intro-level). The overarching issues were: (1) general lack of understanding and misconceptions about mental illness; (2) structural discrimination and paucity of governmental and public support system; (3) burden of “pervasive and unlimited” care and inability of independent living. Conclusions: We identified several features of mental health related stigma and the ensuing discrimination in Czech Republic experienced by persons with severe mental illness and their relatives. We developed a set of recommendations for policy-makers aimed at reducing ignorance and prejudice amongst the public and professionals, improving health and social services—including employment, housing and community integration—and the provision of family support

Size dependent heating efficiency of multicore iron oxide particles in low-power alternating magnetic fields

Aggregates of superparamagnetic nanoparticles, so called multicore particles get much attention due to collective magnetic behaviour. Despite the fact that saturation magnetization and coercivity of multicore particles are lower than for single particles of comparable size, they can generate large amount of heat in alternating magnetic field. This makes them promising for magnetic hyperthermia. However, correlation between internal magnetic structure of multicore particles and their heating ability in alternating magnetic fields are not clear yet. Detailed experimental investigations are required to determine the optimal sizes of multicore particles and the alternating magnetic field parameters to obtain maximal heat. In this study, we demonstrated how hydrodynamic size of multicore particles influences alternating magnetic field energy absorption. Dense aggregates composed of bare magnetic iron oxide nanoparticles of 13 nm were obtained by coprecipitation. Further peptization allowed to gain aqueous dispersions of multicore particles with various hydrodynamic size, varing from 85 to 170 nm, due to electrostatic stabilization. Multicore particles dispersions have saturation magnetization of 40 A m(2)/kg(Fe3O4) and coercivity of 79.6 A/m regardless of their size. Dispersion of 85 nm multicore particles is stable and provides specific loss power of 42 W/g(Fe). Further increase of hydrodynamic size leads to low stability and loss of the ability to generate heat in alternating magnetic field.Ministry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504