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The 90° reorientation of Er3+ spins in ErFeO3 have been directly observed using optical spectroscopy. The peculiarities of the absorption spectrum of ErFeO3 in the region of the 4 I 15/2 → 4 F 9/2 transition of the Er3+ ion in the temperature range of ac-spin reorientation have been studied. It is shown that the spin reorientation phase transition (SRPT) is accompanied by splitting of the ground and excited states into Kramers doublets in the iron exchange field. This fact is a direct evidence of purely magnetic origin of SRPT. The experimental results were used to analyze the magnetic properties of ErFeO3. This analysis showed that the order of magnitude of the magnetic moment, its variation in the SRPT region, and the existence of T comp can be interpreted in terms of the single-ion model, taking into account the influence of the crystal field and the molecular field produced by the iron subsystem ions. [ABSTRACT FROM AUTHOR]

An intermediate state revealed upon a first-order metamagnetic phase transition in a magnetic field aligned parallel to the Ising c axis of Er3+ ions in crystals of erbium ferrite ErFeO3 at a temperature of 1.6 K is visualized for the first time. The region of existence of the intermediate state and the parameters of the domain structure are determined, and the possible conditions providing for visualization of the intermediate state and its specific features are analyzed. A thermodynamic model is proposed for the stabilization of the intermediate state. It is shown that theoretical results are in good agreement with experimental data. [ABSTRACT FROM AUTHOR]

The aim of the work was to estimate the intensity and tissue distribution of proapoptogen p53 expression in duodenal mucosa in patients with acute bleeding caused by peptic ulcers. In 31 patients (1st group) the healing of ulcer was detected after effective endoscopic hemostasis and in 15 patients rebleeding took place (2nd group). Performed immunocytochemical investigation allow to determine that acute ulcer bleeding was associated with activation of marginal zone cells apoptosis which was maximal in covering epithelium, vascular endothelium and regions infiltrated by lymphocytes. In patients with rebleeding the higher values of р53 expression were detected in crypts epithelium and in endothelium of dilatating vessels accompanied with intensive edema and lymphocytes infiltration of lamina propria and muscularis mucosae with perifocal activation of cells death. Additionally to apoptosis in 2nd group duodenum the necrosis of cells and epithelium desquamation were found, reflecting the tissue disintegration of duodenal mucosa.

This review summarizes the currently known biochemical neuroadaptive mechanisms of remote ischemic conditioning. In particular, it focuses on the significance of the pro-adaptive effects of remote ischemic conditioning which allow for the prevention of the neurological and cognitive impairments associated with hippocampal dysregulation after brain damage. The neuroimmunohumoral pathway transmitting a conditioning stimulus, as well as the molecular basis of the early and delayed phases of neuroprotection, including anti-apoptotic, anti-oxidant, and anti-inflammatory components, are also outlined. Based on the close interplay between the effects of ischemia, especially those mediated by interaction of hypoxia-inducible factors (HIFs) and steroid hormones, the involvement of the hypothalamic-pituitary-adrenocortical system in remote ischemic conditioning is also discussed.

Context.—: Because of restrictions as a result of the COVID-19 pandemic, medical educators rapidly transitioned to an online curriculum for pathology resident education. The benefits and challenges of the shift to online learning, as well as strategies to maximize learning, are yet to be fully elucidated., Objective.—: To assess learner perception and satisfaction with the move to online learning. Understanding the benefits of online learning will allow future curricular changes to most effectively incorporate online learning. Understanding the common challenges will allow our current learning strategies to rapidly adapt and ideally mitigate these challenges as online learning is incorporated into medical education., Design.—: This was a survey-based study distributed by email to pathology residents nationwide in Canada in anatomic pathology, general pathology, neuropathology, and hematopathology. Thirty residents participated, from anatomic pathology (n = 23; 76%), from general pathology (n = 5; 16%), and 1 participant each from hematopathology and neuropathology., Results.—: All participants indicated that their program had transitioned to online learning at least in part. The majority of participants (n = 16; 53%) did not feel their pathology education was negatively affected by the transition to online learning; however, a significant minority (n = 6; 20%) felt their education had been negatively affected. Convenience and less intimidation were rated as benefits of online learning. Negative effects included technical issues and decreased engagement; we identified a number of strategies used by programs and pathology residents to mitigate these negative effects., Conclusions.—: Our survey points to a need to use adaptations and best-practice recommendations to maximize the benefits of online learning moving forward., (© 2023 College of American Pathologists.)

Autophagy is a regulated mechanism of degradation of misfolded proteins and organelles in the cell. Neurons are highly differentiated cells with extended projections, and therefore, their functioning largely depends on the mechanisms of autophagy. For the first time in an animal model using immunohistochemistry, dot analysis, and qRT-PCR, the autophagy (macroautophagy) activity in neurons of two brain regions (hippocampus and neocortex) under normoxia and after exposure to hypoxia was studied. It was found that under normoxia, the autophagic activity was higher in the hippocampal neurons than in the neocortex of rats. In the hippocampus, the exposure of rats to hypoxia resulted in a decrease in the content of autophagy markers LC3 and p62, which was followed by activation of the autophagy-related gene expression. In the neocortex, no changes in these marker proteins were observed after the exposure to hypoxia. These data indicate that the neurons in the hippocampus and neocortex differ in the autophagy response to hypoxia, which may reflect the physiological and functional differences of the pyramidal cells of these brain regions and may to some extent account for the extreme vulnerability of the CA1 hippocampal neurons and relatively high resistance of the neocortical neurons to hypoxia.

The coronavirus disease 2019 pandemic resulted in a dramatic change in the Royal College of Physicians and Surgeons of Canada assessment process through elimination of the oral and practical components of the 2020 Anatomical Pathology examination. Our study sought to determine stakeholder opinions and experiences on these changes in the context of the 2019 implementation of competency-based medical education. Surveys were designed for residents and practicing pathologists. In total, 57 residents (estimated response rate 29%) and 185 pathologists (estimated response rate 19%) participated across Canada; 67% of pathologists disagreed with the 2020 Royal College examination changes, compared with 30% for residents (P = <.00001). When asked whether the Royal College examination should be eliminated, 95% of pathologists indicated they would be against this, compared to only 34% of residents (P = <.00001). Perceptions on changes to and importance of different components of assessment in competency-based medical education were similar between pathologists and residents, with participants perceiving assessment practices to have changed fairly little since its implementation, with the exception of more frequent feedback. Analysis of narrative comments identified several common themes around assessment, including the need for objectivity and standardization and the problem of failure-to-fail. However, residents identified numerous elements of their performance that can be assessed only through longitudinal evaluation. Pathologists, on the other hand, tended to view these aspects of performance as laden with bias. Our results will hopefully help guide future innovation in assessment by characterizing different stakeholder perspectives on key issues in medical education., Competing Interests: Declaration of Conflicting Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article., (© The Author(s) 2021.)