ABSTRACT Purpose: Stroke is an acute cerebrovascular disease. Astragaloside IV (AS-IV) is an active ingredient extracted from Astragalus membranaceus with an established therapeutic effect on central nervous system diseases. This study examined the neuroprotective properties and possible mechanisms of AS-IV in stroke-triggered early brain injury (EBI) in a rat transient middle cerebral artery occlusion (MCAO) model. Methods: The neurological scores and brain water content were analyzed. 2,3,5-triphenyl tetrazolium chloride (TTC) staining was utilized to determine the infarct volume, neuroinflammatory cytokine levels, and ferroptosis-related genes and proteins, and neuronal damage and molecular mechanisms were evaluated by terminal deoxynucleotidyl transferase dutp nick-end labeling (TUNEL) staining, western blotting, and real-time polymerase chain reaction. Results: AS-IV administration decreased the infarct volume, brain edema, neurological deficits, and inflammatory cytokines TNF-α, interleukin-1β (IL-1β), IL-6, and NF-κB, increased the levels of SLC7A11 and glutathione peroxidase 4 (GPX4), decreased lipid reactive oxygen species (ROS) levels, and prevented neuronal ferroptosis. Meanwhile, AS-IV triggered the Nrf2/HO-1 signaling pathway and alleviated ferroptosis due to the induction of stroke. Conclusions: Hence, the findings of this research illustrate that AS-IV administration can improve delayed ischemic neurological deficits and decrease neuronal death by modulating nuroinflammation and ferroptosis via the Nrf2/HO-1 signaling pathway.

The first years of teaching are often discussed with reference to all teachers. More studies focusing on early career content specialists are needed in order to ensure that teachers are supported adequately as they learn to teach in their content area. In this study, we followed 76 newly hired secondary science teachers to determine how their teaching beliefs and knowledge changed over a three-year period. This study used qualitative and quantitative data collection and analysis techniques. Interviews and classroom observations were collected and analyzed quantitatively using teachers as a group and the teachers' induction programs as a subgroup. The findings from this study suggest that over time new teachers are more influenced by their school cultures than by their induction programs. However, from the data it is evident that beliefs and practices are malleable, but that they are impacted differently and by different factors. As a result of this study, we suggest new directions for science teacher educators in their work and potential research regarding newly hired science teachers.

Los primeros años de enseñanza son a menudo discutidos con referencia a todos los profesores, no con relación a aquellos que imparten un nuevo contenido. Se requieren más estudios diseñados para los especialistas en contenidos de carrera temprana, para asegurar que están apoyados adecuadamente conforme aprenden a enseñar en su nueva área de contenido. En este estudio seguimos a 76 maestros de ciencia de la secundaria para determinar cómo sus creencias y conocimientos se transformaban durante un periodo de tres años. En él se utilizaron técnicas de análisis y colecta de datos tanto cualitativas como cuantitativas. También se emplearon entrevistas y observaciones de clase, y estos datos se analizaron cuantitativamente con el uso del grupo de los profesores y los programas de inducción de los profesores como subgrupo. Los hallazgos de este estudio sugieren que los nuevos profesores están muy influidos por la cultura de su escuela. No obstante, a partir de los datos resulta evidente que sus creencias y prácticas son maleables, pero que se ven impactadas de forma variada por diferentes factores. A partir de este estudio se sugieren nuevas recomendaciones para los educadores de profesores de ciencia, tanto para su trabajo como para su investigación potencial, con relación a profesores de ciencia recién contratados.