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Background: Reports from countries severely hit by the COVID-19 pandemic suggest a decline in acute coronary syndrome (ACS)-related hospitalizations. The generalizability of this observation on ACS admissions and possible related causes in countries with low COVID-19 incidence are not known.

Chemical bonding is a fundamental but complex topic, which has traditionally been associated with learning difficulties, misunderstandings, and misconceptions. This paper reviews some previous studies, concerning students’ conceptual difficulties and reports the findings from a research study with Greek students, which set out to examine their knowledge and understanding of a number of key concepts related to bonding. Three student samples were studied; one consisted of tenth-grade students from three public schools, the second contained first-year chemistry and biology students at the beginning of their university courses, and the third involved tenth-grade students from a prestigious private school. The students generally exhibited limited knowledge and possessed certain misconceptions, with the private school and the university students demonstrating better knowledge than the public school students. A quasi-experimental research design was employed using students from the private school, with some students used as a control group and others as a treatment group. The control group was taught using the standard Greek chemistry textbook, while the treatment group used enriched teaching material. It was found that while the two groups demonstrated similar performance for many bonding concepts, the treatment group did show superior knowledge with respect to a number of issues, such as the role of electrostatic interactions, electronegativity, and bond polarity.

One way of checking tο what extent instructional textbooks achieve their aim is to evaluate the questions they contain. In this work, we analyze the questions that are included in the chapters on chemical bonding of ten general chemistry textbooks. We study separately the questions on intraand on intermolecular bonding, with the former outnumbering the latter by far. Two aspects of the questions are examined: their form (closed or open type, including their various forms), and the kind of knowledge they test (declarative or procedural knowledge). Questions were further partitioned into four categories, following Pearson and Johnson's and Raphael's schemes of Question-Answer Relationship (QAR) in which: (1) text-centered questions are divided into (a) 'precisely there', and (b) 'think and search'; and (2) cognition-centered questions that are divided into 'you and the author' and 'on your own'. The following conclusions were drawn: closed-type questions outnumber by far the open-type ones, and are mainly of the 'short answer' category; the majority test for declarative knowledge, with fewer questions testing for procedural knowledge; there was complete lack of metacognitive questions; no questions were found that deal with relevant experimental processes. Implications for textbook authors and teachers are discussed.

This study investigated the impact of television violence on memory for advertising, taking into account the possible role of vicwcr hostility arousal in this context. Experimental participants were exposed to advertising placed within a violent or a nonviolent film clip.One advertisement had 2 versions-violent and nonviolent-and was presented with 2 other nonviolent filler advertisements. Participants completed a mood questionnaire before and after being exposed to the television material, tested for memory for the embedded advertising and asked to rate the film clips and the advertisements using a set of evaluative scales. The nonviolent version of the target advertisement was less well remembered when placed in the violent film than in the nonviolent film, supporting Bushman and Bonacci (2002). In contrast, the violent version of the target advertisement was remembered much better than the nonviolent version when placed in the violent film scqucncc. Participants' hostility scores were higher only after watching the violent film, and associated with an impairment in the memory of the nonviolent advertisements, while enhancing the memory of the violent advertisement, thus providing some support for Bushman's (1 998a) hostile-thought hypothesis.