Effects of Ni/Co doping on structural and electronic properties of 122 and 112 families of Eu based iron pnictides.

Superconductivity in high-temperature superconductors such as cuprates or iron pnictides is typically achieved by hole or electron doping and it is of great interest to understand how doping affects their properties leading to superconductivity. To study it we conducted Fe and As K edge x-ray absorption spectroscopy measurements on several electron doped compounds from the 112 and 122 family of Eu-based iron pnictides. XANES and EXAFS results confirm that dopants are located at expected sites. For both families we found an electron charge redistribution between As and Fe occurring with doping. The changes it caused are stronger in the 112 family and they are bigger at As sites, which indicates that doped charges are predominantly localized on the dopant site. However, the results obtained do not provide clues why Ni doping in 122 family does not lead to occurrence of superconductivity.

One-Step Preparation of Highly Stable Copper-Zinc Ferrite Nanoparticles in Water Suitable for MRI Thermometry.

Superparamagnetic ferrite nanoparticles coated with a polymer layer are widely used for biomedical applications. The objective of this work is to design nanoparticles as a magnetic resonance imaging (MRI) temperature-sensitive contrast agent. Copper-zinc ferrite nanoparticles coated with a poly(ethylene glycol) (PEG) layer are synthesized using a one-step thermal decomposition method in a polymer matrix. The resulting nanoparticles are stable in water and biocompatible. Using Mössbauer spectroscopy and magnetometry, it was determined that the grown nanoparticles exhibit superparamagnetic properties. Embedding these particles into an agarose gel resulted in significant modification of water proton relaxation times T 1, T 2, and T 2* determined by nuclear magnetic resonance measurements. The results of the spin-echo T 2-weighted MR images of an aqueous phantom with embedded Cu0.08Zn0.54Fe2.38O4 nanoparticles in the presence of a strong temperature gradient show a strong correlation between the temperature and the image intensity. The presented results support the hypothesis that CuZn ferrite nanoparticles can be used as a contrast agent for MRI thermometry.

Self-Assessed Personality Traits and Adherence to the COVID-19 Lockdown.

Introduction: The COVID-19 pandemic, caused by the SARS-CoV-2 coronavirus, has forced all countries affected by it to introduce quarantine and isolation to prevent the spread of the virus, as well as masking and distancing. Not everyone is equally willing to follow the rules related to limit the extent of the coronavirus epidemic. This might be connected with personality traits, especially openness, positive attitude, and optimism. Materials and Methods: An online survey was created and completed by participants in April-May 2020. Self-assessment of personality traits and adherence to lockdown recommendations were assessed. A total of 7404 participants took part in the study, mainly from Poland (83.6%) and Italy (12.7%). Univariate and multivariate regression analysis was performed. Results: The participants were divided into groups depending on the degree of compliance with the lockdown rules. In the multivariate analysis, variables that increased the odds for stricter lockdown compliance were temporary work suspension OR 1.27 (95% CI 1.10-1.48), income level "we can't handle this situation" OR 1.67 (95%CI 1.20-2.33), and junior high school education OR 1.68 (95% CI 1.13-2.50). Other significant factors included age and place of residence. Each point of self-assessed sociability OR 1.07 (95% CI 1.00-1.13) also increased the likelihood of adhering to lockdown rules. Conclusions: Taking the basic demographic characteristics as well as working and health environment conditions traits into account may be helpful when forecasting epidemiological compliance during a pandemic, as well as in other public health tasks. The key role of self-assessed personality traits was not confirmed in this study. Reliability of the results is limited by significant disproportions in the size of the study groups.

Perceived Stress Levels among Ukrainian Migrant and LGBT+ Minorities in Poland during the COVID-19 Pandemic.

The Coronavirus disease 2019 (COVID-19) pandemic, immigrant status and being a member of the LGBT+ community are all independent factors associated with increased stress levels. Few studies provide more complex analysis on this issue, and there has been no research on the cumulative burden of perceived stress that people belonging to both minorities experience in the current epidemiological situation. The aim of this study was to assess the ability to deal with an external situation during the third wave of the COVID-19 pandemic in Poland in the following groups with different stress levels (total sample n = 370): Polish heterosexual men (n = 202), heterosexual men from Ukraine (n = 131) and homo- and bisexual men (men who have sex with men-MSM) from Ukraine (n = 37). A Perceived Stress Scale (PSS-10) was used. The analysis of the survey did not show statistically significant differences between the three study groups in the general level of perceived stress (24.71, 24.77 and 26.49 points, respectively, p = 0.551), but it revealed numerous differences in coping with various aspects of everyday functioning between these groups. Negative assessment of one's own health proved to be the main factor negatively affecting the level of perceived stress, however specific health risks, medical history or the participants' previous experience have not been taken into account in the study. Our research shows differences in the needs, resources and methods of coping with stress between men who are Polish citizens and migrants from Ukraine, both heterosexual and belonging to the MSM group. Proper identification and addressing of these needs, taking into account different availability of health services, could be the responsibility of NGOs or insurance providers. This should result in the reduction of mental health burdens and the risk of developing serious mental disorders, and consequently in better functioning of persons belonging to minorities and in a reduced burden on the health care system.

Surface Properties and Morphology of Boron Carbide Nanopowders Obtained by Lyophilization of Saccharide Precursors.

The powders of boron carbide are usually synthesized by the carbothermal reduction of boron oxide. As an alternative to high-temperature reactions, the development of the carbothermal reduction of organic precursors to produce B4C is receiving considerable interest. The aim of this work was to compare two methods of preparing different saccharide precursors mixed with boric acid with a molar ratio of boron to carbon of 1:9 for the synthesis of B4C. In the first method, aqueous solutions of saccharides and boric acid were dried overnight at 90 °C and pyrolyzed at 850 °C for 1 h under argon flow. In the second method, aqueous solutions of different saccharides and boric acid were freeze-dried and prepared in the same way as in the first method. Precursors from both methods were heat-treated at temperatures of 1300 to 1700 °C. The amount of boron carbide in the powders depends on the saccharides, the temperature of synthesis, and the method of precursor preparation.

Social Isolation During COVID-19 Pandemic. Perceived Stress and Containment Measures Compliance Among Polish and Italian Residents.

BACKGROUND: In this study, we analyze the association of social isolation in the first phase of the pandemic with perceived stress among residents of Poland and Italy with a look at how these populations adjust to and comply with implemented regulations, guidelines, and restrictions. MATERIALS AND METHODS: Internet survey with Perceived Stress Scale (PSS-10) and questions regarding mobility patterns, attitude, and propensity to adjust toward the implemented measures and current health condition was made among Polish and Italian residents (Cronbach's alpha 0.86 and 0.79, respectively). The sample size was 7,108 (6,169 completed questionnaires in Poland and 939 in Italy). RESULTS: The Polish group had a higher stress level than the Italian group (mean PSS-10 total score 22,14 vs 17,01, respectively; p < 0.01). There was a greater prevalence of chronic diseases among Polish respondents. Italian subjects expressed more concern about their health, as well as about their future employment. Italian subjects did not comply with suggested restrictions as much as Polish subjects and were less eager to restrain from their usual activities (social, physical, and religious), which were more often perceived as "most needed matters" in Italian than in Polish residents. CONCLUSION: Higher activity level was found to be correlated with lower perceived stress, but the causality is unclear. Difference in adherence to restrictions between Polish and Italian residents suggests that introducing similar lockdown policies worldwide may not be as beneficial as expected. However, due to the applied method of convenience sampling and uneven study groups, one should be careful with generalizing these results.

Attitudes and Perceptions of Health Protection Measures Against the Spread of COVID-19 in Italy and Poland.

Background: During the first wave of the COVID-19 pandemic (April to May 2020), 6,169 Polish and 939 Italian residents were surveyed with an online questionnaire investigating socio-demographic information and personality traits (first section) as well as attitudes, position, and efficacy perceptions on the impact of lockdown (second section) and various health protection measures enforced (third section). Methods: The "health protection attitude score" (HPAS), an endpoint obtained by pooling up the answers to questions of the third section of the survey tool, was investigated by multiple linear regression models, reporting regression coefficients (RC) with 95% confidence intervals (95% CI). Results: Concerns for business and health due to COVID-19 were associated with a positive attitude toward risk reduction rules. By contrast, male sex, concerns about the reliability of information available online on COVID-19 and its prevention, along with the feeling of not being enough informed on the transmissibility/prevention of SARS-CoV-2 were associated with a negative attitude toward risk mitigation measures. Discussion: A recent literature review identified two social patterns with different features in relation to their attitude toward health protection rules against the spread of COVID-19. Factors positively associated with adherence to public health guidelines were perceived threat of COVID-19, trust in government, female sex, and increasing age. Factors associated with decreased compliance were instead underestimation of the COVID-19 risk, limited knowledge of the pandemic, belief in conspiracy theories, and political conservativism. Very few studies have tested interventions to change attitudes or behaviors. Conclusion: To improve attitude and compliance toward risk reduction norms, a key intervention is fostering education and knowledge on COVID-19 health risk and prevention among the general population. However, information on COVID-19 epidemiology might be user-generated and contaminated by social media, which contributed to creating an infodemic around the disease. To prevent the negative impact of social media and to increase adherence to health protection, stronger content control by providers of social platforms is recommended.

Impact of sunflower (Helianthus annuus L.) extracts upon reserve mobilization and energy metabolism in germinating mustard (Sinapis alba L.) seeds.

One commonly observed effect of phytotoxic compounds is the inhibition or delay of germination of sensitive seeds. Mustard (Sinapis alba L.) seeds were incubated with aqueous extracts of sunflower (Helianthus annuus L.) leaves. Although sunflower phytotoxins did not influence seed viability, extracts completely inhibited seed germination. Inhibition of germination was associated with alterations in reserve mobilization and generation of energy in the catabolic phase of germination. Degradation of lipids was suppressed by sunflower foliar extracts resulting in insufficient carbohydrate supply. The lack of respiratory substrates and decrease in energy (ATP) generation resulted in suppression of the anabolic phase of seed germination and ultimately growth inhibition.

[Multifocal oscillatory potentials (mfOPs) in patients with central retinal vein occlusion]. / Wieloogniskowe potencjaly oscylacyjne (mOPs) u chorych z zakrzepem zyly srodkowej siatkówki.

PURPOSE: To evaluate usefulness of multifocal oscillatory potentials (mfOPs) in diagnostics in patients with retinal vein occlusions. MATERIAL AND METHODS: The Visual Evoked Imaging System (VERIS, version 4.9) was used to stimulate the visual system to elicit mfOPs from 103 areas subtending the central 70-80 degrees of the retina in three patients with central or branch retinal vein occlusions. Two stimulating conditions were used. For each subject, the mean first- and second-order kernel responses from occlusion area, were analyzed and compared with the fellow eye and control subjects results. RESULTS: In retinal areas without circulatory disturbances in fluorescein angiography all mfOPs components were present. In a patient with branch retinal vein occlusion in the area without capillary perfusion mfOPs responses were not detectable. CONCLUSIONS: The mfOPs are in a large extent dependent on a proper retinal circulation. The recording of mfOPs may be useful in clinical diagnosis, to asses circulatory disturbances in internal layers of the retina and in differentiation of ischemic from non ischemic retinal vein occlusions.

[Multifocal electroretinogram]. / Elektroretinogram wieloogniskowy

The paper presents current state of knowledge regarding multifocal electroretinography (mfERG). The theoretical basis of this technique, procedure, methods and examples of use in clinical diagnostics are presented.