Enantioselective Photochemical Reactions Enabled by Triplet Energy Transfer.

For molecules with a singlet ground state, the population of triplet states is mainly possible (a) by direct excitation and subsequent intersystem crossing or (b) by energy transfer from an appropriate sensitizer. The latter scenario enables a catalytic photochemical reaction in which the sensitizer adopts the role of a catalyst undergoing several cycles of photon absorption and subsequent energy transfer to the substrate. If the product molecule of a triplet-sensitized process is chiral, this process can proceed enantioselectively upon judicious choice of a chiral triplet sensitizer. An enantioselective reaction can also occur in a dual catalytic approach in which, apart from an achiral sensitizer, a second chiral catalyst activates the substrate toward sensitization. Although the idea of enantioselective photochemical reactions via triplet intermediates has been pursued for more than 50 years, notable selectivities exceeding 90% enantiomeric excess (ee) have only been realized in the past decade. This review attempts to provide a comprehensive survey on the various photochemical reactions which were rendered enantioselective by triplet sensitization.

Photoinduced B-Cl Bond Fission in Aldehyde-BCl3 Complexes as a Mechanistic Scenario for C-H Bond Activation.

In concert with carbonyl compounds, Lewis acids have been identified as a versatile class of photocatalysts. Thus far, research has focused on activation of the substrate, either by changing its photophysical properties or by modifying its photochemistry. In this work, we expand the established mode of action by demonstrating that UV photoexcitation of a Lewis acid-base complex can lead to homolytic cleavage of a covalent bond in the Lewis acid. In a study on the complex of benzaldehyde and the Lewis acid BCl3, we found evidence for homolytic B-Cl bond cleavage leading to formation of a borylated ketyl radical and a free chlorine atom only hundreds of femtoseconds after excitation. Both time-dependent density functional theory and transient absorption experiments identify a benzaldehyde-BCl2 cation as the dominant species formed on the nanosecond time scale. The experimentally validated B-Cl bond homolysis was synthetically exploited for a BCl3-mediated hydroalkylation reaction of aromatic aldehydes (19 examples, 42-76% yield). It was found that hydrocarbons undergo addition to the C═O double bond via a radical pathway. The photogenerated chlorine radical abstracts a hydrogen atom from the alkane, and the resulting carbon-centered radical either recombines with the borylated ketyl radical or adds to the ground-state aldehyde-BCl3 complex, releasing a chlorine atom. The existence of a radical chain was corroborated by quantum yield measurements and by theory. The photolytic mechanism described here is based on electron transfer between a bound chlorine and an aromatic π-system on the substrate. Thereby, it avoids the use of redox-active transition metals.

Novel Oxidative Ugi Reaction for the Synthesis of Highly Active, Visible-Light, Imide-Acridinium Organophotocatalysts.

A newly designed class of acridinium-based organophotocatalysts bearing an imide group at the C9-position is presented. To achieve these unprecedented structures, a synthetic strategy based on a novel straightforward oxidative Ugi-type reaction at the benzylic position of C9-unsubstituted acridanes was developed. The introduction of the imide-unit affords a notable photocatalytic activity enhancement, allowing efficient transformations in different oxidative and reductive visible-light catalytic reactions.

Visible-Light Photocatalytic Intramolecular Cyclopropane Ring Expansion.

Described herein is a new visible-light photocatalytic strategy for the synthesis of enantioenriched dihydrofurans and cyclopentenes by an intramolecular nitro cyclopropane ring expansion reaction. Mechanistic studies and DFT calculations are used to elucidate the key factors in this new ring expansion reaction, and the need for the nitro group on the cyclopropane.

Nursing performance under high workload: a diary study on the moderating role of selection, optimization and compensation strategies.

AIMS: The aim of this study was to investigate whether selective optimization with compensation constitutes an individualized action strategy for nurses wanting to maintain job performance under high workload. BACKGROUND: High workload is a major threat to healthcare quality and performance. Selective optimization with compensation is considered to enhance the efficient use of intra-individual resources and, therefore, is expected to act as a buffer against the negative effects of high workload. DESIGN: The study applied a diary design. Over five consecutive workday shifts, self-report data on workload was collected at three randomized occasions during each shift. Self-reported job performance was assessed in the evening. Self-reported selective optimization with compensation was assessed prior to the diary reporting. METHODS: Data were collected in 2010. Overall, 136 nurses from 10 German hospitals participated. Selective optimization with compensation was assessed with a nine-item scale that was specifically developed for nursing. The NASA-TLX scale indicating the pace of task accomplishment was used to measure workload. Job performance was assessed with one item each concerning performance quality and forgetting of intentions. RESULTS: There was a weaker negative association between workload and both indicators of job performance in nurses with a high level of selective optimization with compensation, compared with nurses with a low level. Considering the separate strategies, selection and compensation turned out to be effective. CONCLUSION: The use of selective optimization with compensation is conducive to nurses' job performance under high workload levels. This finding is in line with calls to empower nurses' individual decision-making.

Evaluation of two study demands-resources-based interventions: a randomized controlled trial.

Introduction: Higher education students experience significant levels of exhaustion in their studies, yet there are limited evidence-based support programs available. Therefore, this study evaluated a novel intervention approach by testing the effectiveness of two online interventions based on the study demands-resources framework. These interventions aimed to balance demands and resources. Derived from the theoretical assumptions of the framework, we hypothesized that the interventions would increase study and personal resources, engagement, and study crafting, and decrease study demands, exhaustion, and self-undermining. Additionally, we hypothesized that demands and resources would mediate the effects of the intervention on engagement, exhaustion, study crafting, and self-undermining. Methods: Conducted as a randomized controlled trial with a waitlist control group (n = 71), the study involved participants in two intervention groups who engaged with the interventions for 2 weeks. Intervention group 1 (n = 64) focused on adapting demands, while intervention group 2 (n = 70) focused on increasing resources. The design allowed for a comparison of the effectiveness of these different approaches. Participants completed questionnaires before and after the intervention, and at a 5-week follow-up. Results: Results of the analyses of variance with repeated measures revealed that the interventions had significant positive effects on the personal resource mindfulness, two study crafting strategies, self-undermining, and exhaustion. Notably, intervention group 2 exhibited more positive outcomes. The hypothesized mediation effects through mindfulness were partially supported. Discussion: The study demonstrates the considerable potential of interventions based on the study demands-resources framework for higher education institutions in supporting student well-being.

The association between health behaviours and academic performance moderated by trait mindfulness amongst university students: an observational study.

Objectives: To target health communication at less health-conscious groups, evidence on health behaviours' effects on non-health-related outcomes - such as academic performance - is necessary. Recent research has highlighted the associations of various health behaviours on academic performance of university students. However, there is a lack of research investigating the most predominant health behaviours simultaneously and their association with academic performance, as well as the factors that potentially influence the direction or strength of these associations. Therefore, this study investigated (I) which of the predominant health behaviours (physical activity, healthy diet, sleep, sedentary behaviour, alcohol consumption, smoking, drug use) are most associated with academic performance and (II) whether the personal resource of trait mindfulness moderates these associations. Methods: An online survey was conducted amongst university students during the 2021 summer semester. Group differences in academic performance regarding health behaviours were analysed using ANOVA (N = 1,049). A first linear regression model (N = 571), considering all selected health behaviours simultaneously, assessed their association with academic performance. A second model (N = 540) assessed interaction effects of health behaviours and trait mindfulness. Separate regressions assessed each interaction's association with academic performance. Results: Sleep, fruit and vegetable consumption, and gender were significantly associated with academic performance. The second model showed no significant interaction effects. Conclusion: Targeting sleep and fruit and vegetable consumption might be the most promising strategies for elevating students' academic performance, thereby enabling health communication strategies to reach groups driven by performance improvements rather than health benefits.

Conditional reciprocal stressor-strain effects in university students: a cross-lagged panel study in Germany.

University students worldwide are facing increasing mental health challenges. Traditional stress models, like the Job/Study Demand-Resources Model, link stressors directly to strain. Yet, recent studies suggest the influence of strain on stressors may be even stronger. Our research explored these reciprocal dynamics among university students, considering social support and mindfulness as potential moderators. We conducted a two-wave panel study with 264 university students. We ran separate cross-lagged panel structural equation analyses for three key health outcomes-emotional exhaustion, depression, and well-being-each paired with perceived study stressors, specifically workload and work complexity. Findings revealed significant stressor and strain effects, with social support notably moderating the impact of emotional exhaustion on workload. These insights challenge traditional stress theories and underscore the importance of mental health support and effective stress management strategies for students, emphasizing the need for proactive mental health initiatives in academic environments.

Dealing with information overload: a comprehensive review.

Information overload is a problem that is being exacerbated by the ongoing digitalization of the world of work and the growing use of information and communication technologies. Therefore, the aim of this systematic literature review is to provide an insight into existing measures for prevention and intervention related to information overload. The methodological approach of the systematic review is based on the PRISMA standards. A keyword search in three interdisciplinary scientific databases and other more practice-oriented databases resulted in the identification of 87 studies, field reports, and conceptual papers that were included in the review. The results show that a considerable number of papers have been published on interventions on the behavioral prevention level. At the level of structural prevention, there are also many proposals on how to design work to reduce information overload. A further distinction can be made between work design approaches at the level of information and communication technology and at the level of teamwork and organizational regulations. Although the identified studies cover a wide range of possible interventions and design approaches to address information overload, the strength of the evidence from these studies is mixed.

Hindrance demands as a boundary condition to the appraisal of challenge demands.

BACKGROUND AND OBJECTIVES: Studies show that prototypical challenge demands can be appraised as challenging, hindering and threatening. Yet, to date there exists no clear reasoning as to why these different appraisals occur. Drawing on transactional stress theory, we propose that co-occurring hindrance demands likely affect the day-specific appraisal of challenge demands (i.e., time pressure and complexity). DESIGN AND METHOD: To test this proposition we conducted a daily diary study with 432 employees. We tested our hypotheses using multi-level latent interaction analyses at the within-person level. RESULTS: Results revealed that on days when individuals experienced more hindrance demands, they were less likely to appraise time pressure and complexity as challenging and more likely to appraise them as hindering or threatening. CONCLUSION: The results outline the need to consider co-occurring hindrance demands when assessing appraisal patterns associated with challenge demands.

Fostering study crafting to increase engagement and reduce exhaustion among higher education students: A randomized controlled trial of the STUDYCoach online intervention.

The study demands-resources framework states that study demands increase exhaustion and study resources increase engagement. Study crafting describes a student's proactive adaption to demands and resources. To date, no intervention in the higher education context has aimed to foster study crafting. Accordingly, this study developed and evaluated the STUDYCoach online intervention, which aimed to increase engagement and reduce exhaustion by promoting study crafting. The study was a randomized controlled trial with a waiting-list control group. All participants (N = 209) completed a questionnaire before (T1) and after (T2) the intervention and at a 20-week follow-up (T3). Participants in the intervention group (n = 149) used the STUDYCoach over three consecutive weeks. Results showed that overall study crafting, decreasing hindering demands, and engagement significantly increased in the intervention group compared to the control group after the intervention. All effects remained stable at follow-up. Notably, exhaustion decreased significantly in the intervention group from T1 to T3 and T2 to T3. Study crafting mediated the intervention's effect on engagement and exhaustion. Our study extends the study demands-resources framework and the literature on job crafting by confirming that study crafting interventions can be effective in higher education.

Validation of the irritation scale on a representative German sample: new normative data.

The irritation scale is a widely used and reliable self-report scale for measuring cognitive and emotional strain related to the work environment. It extends existing measures by providing a sensitive assessment for pre-clinical stress at work. Existing normative data are based on convenience samples and are therefore not representative. This study provides new normative data for the irritation scale based on a representative German sample (N = 1480). The new normative data indicate that the overall level of irritation in the German workforce is significantly lower compared to previously published data. Convergent and discriminant validity is confirmed by correlations with depression and anxiety (Patient Health Questionnaire-4 for Depression and Anxiety), somatic symptom scales (Bodily Distress Syndrome 25 checklist, Somatic Symptom Scale-8, Giessen Subjective Complaints List-8, comorbidity), psychological functioning (Mini-ICF rating for activity and participation disorders in mental illness), work-related stressors (overcommitment and bullying) and individual resources (self-efficacy). The results confirm the utility of the irritation scale and provide new benchmarks that avoid an underestimation of the levels of irritation in future studies.

Sedentary time of university students before and during the COVID-19 pandemic: Risk groups and pre-pandemic predictors using cross-sectional and longitudinal data.

Background: The present study aimed to (1) assess and compare sedentary time (ST) of university students before and during the COVID-19 pandemic, (2) examine risk groups with regard to ST and the "extent of change" in ST (from before to during the pandemic) in association with sociodemographic (gender, age), study-related (degree aspired to, field of study, semester), and pre-pandemic physical health-related [pre-pandemic physical activity (PA) and ST levels, pre-pandemic BMI class] variables, and (3) investigate whether the change in ST was predicted by these variables. Methods: Two online surveys were conducted among students at the University of Mainz, Germany-the first in 2019 (before the pandemic) and the second in 2020 (during the pandemic). Participants of both surveys were included in a longitudinal sample. With the longitudinal sample's data, paired t-tests, single factor, and mixed analyses of variances were used to examine group differences in ST and the "extent of change" in ST. A linear regression analysis was computed to investigate the influence of the abovementioned sociodemographic, study-related, and pre-pandemic physical health-related variables on the change in ST. Results: Of the N = 4,351 (pre-pandemic) and N = 3,066 (in-pandemic) participants of the online surveys, N = 443 entered the longitudinal sample. ST increased by 1.4 h/day to critical levels (≥8 h/day) in all subgroups analyzed-even among students who were highly physically active before the pandemic. Students with a low pre-pandemic ST had the largest increase in ST. Pre-pandemic PA level negatively predicted the change in ST. Conclusion: Even during a global pandemic lockdown, individuals who were previously more physically active and had less ST showed more health-promoting behavior in terms of ST. Therefore, it can be stated that efforts to promote PA and reduce ST are always valuable. Since ST increased and was worryingly high in all subgroups analyzed, all university students should be targeted by multidimensional approaches to tackle ST and promote their health.

Mental health state and its determinants in German university students across the COVID-19 pandemic: findings from three repeated cross-sectional surveys between 2019 and 2021.

Background: Students were at an increased risk for elevated mental symptoms during the first year of the COVID-19 pandemic compared to pre-pandemic levels. As universities remained closed much longer than anticipated, the mental burden was expected to persist through the second year of the pandemic. The current study aimed to investigate the prevalence of mental distress from 2019 through 2021 and identify risk factors for elevated mental burden, focusing on gender. Methods: We analyzed three cross-sectional online surveys among students at the University of Mainz, conducted in 2019 (n = 4,351), 2020 (n = 3,066), and 2021 (n = 1,438). Changes in the prevalence of depressive symptoms, anxiety, suicidal ideation, and loneliness were calculated using Pearson's chi-square tests and analyses of variance. Multiple linear regressions yielded associated risk factors. Results: The proportion of students with clinically relevant depressive symptoms was significantly higher during the pandemic (38.9% in 2020, and 40.7% in 2021), compared to pre-pandemic (29.0% in 2019). Similarly, more students reported suicidal ideation and generalized anxiety during the pandemic with a peak in the second pandemic year (2021). The level of loneliness was significantly higher in 2020, compared to 2019, and remained at a high level in 2021 (p < 0.001, ηp2 = 0.142). Female and diverse/open gender, being single, living alone, and being a first-year student were identified as risk factors associated with mental burden during the pandemic. Discussion: Mental burdens remained elevated among students through the second year of the pandemic and were associated with socio-demographic risk factors and pandemic-related concerns. Future research should monitor recovery and evaluate the need for psychosocial support.

Cigarette Smoking, Risky Alcohol Consumption, and Marijuana Smoking among University Students in Germany: Identification of Potential Sociodemographic and Study-Related Risk Groups and Predictors of Consumption.

(1) Background: Cigarette smoking, risky alcohol consumption, and marijuana smoking are the most common behaviors related to legal and illicit drug use worldwide, including among university students. To plan effective evidence-based programs to prevent the risky consumption of these substances among university students, the present study aimed to identify potential sociodemographic and study-related risk groups and predictors of consumption. (2) Methods: A cross-sectional online health survey with approximately 270 health-related items was conducted among students at the University of Mainz, Germany. Cigarette smoking, risky alcohol consumption (AUDIT-C score: female ≥ 4, male ≥ 5), and marijuana smoking were chosen as dependent variables. Of the 270 health-related items, 56 were chosen as independent variables and collated into five groups (sociodemographic, psychological, study-related psychosocial, general psychosocial and health behavior). The prevalence of cigarette smoking, risky alcohol consumption, and marijuana smoking was assessed using established and validated instruments. Pearson's chi-square test was used to analyze the differences in prevalence between the sociodemographic and study-related groups, and binary logistic regression was used for analyses with stepwise inclusion of the five variable groups. (3) Results: Of the 3991 university students who entered the analyses, 14.9% reported smoking cigarettes, 38.6% reported risky alcohol consumption, and 10.9% reported smoking marijuana. The prevalence of these differed between genders, fields of study, and aspired degree level, among other factors. Binary logistic regression analyses revealed nine significant predictors (p ≤ 0.05) of cigarette smoking (Nagelkerke R2 = 0.314), 18 significant predictors of risky alcohol consumption (Nagelkerke R2 = 0.270), and 16 significant predictors of marijuana smoking (Nagelkerke R2 = 0.239). (4) Conclusions: This study showed cigarette smoking, risky alcohol consumption, and marijuana smoking among university students in Germany to be associated with multiple factors, especially health behaviors. Furthermore, each of the substances was highly associated with each of the two other substances we examined. Other variable groups, such as psychological or psychosocial variables, seemed to play a rather minor role. Therefore, our recommendation for future prevention programs is that substance use among university students should be addressed as a whole, not just in terms of specific substances.

Bicyclo[2.1.1]hexanes by Visible Light-Driven Intramolecular Crossed [2 + 2] Photocycloadditions.

Bicyclo[2.1.1]hexanes have become increasingly popular building blocks in medicinal chemistry as bridged scaffolds that provide unexplored chemical space. We herein report a visible light-driven approach to these compounds that relies on an intramolecular crossed [2 + 2] photocycloaddition of styrene derivatives enabled by triplet energy transfer. Bicyclo[2.1.1]hexanes were obtained in good to high yields (19 examples, 61%-quantitative yield) and allowed for further functionalizations by consecutive reactions, thereby opening different pathways to decorate the aliphatic core structure.

Examining how different social account timings influence stress resolution in the aftermath of a psychological contract breach.

A great deal of empirical research on the consequences of a psychological contract breach (PCB) has overlooked the role of time in understanding individuals' reactions to a PCB. Moreover, psychological contract research primarily focuses on how employees react to perceptions of a PCB, while questions regarding how the organization's responsiveness (i.e., social account) might impact these reactions remain unanswered. We aimed to enhance the understanding of stress reactions and recovery that are triggered by PCB perceptions and stimulate empirical research that treats psychological contracts as a dynamic phenomenon. Drawing on the conservation of resources theory, we investigated how social account delivery timing-and its subjective experience-influences individuals' stress resolution processes in the aftermath of a PCB. To this end, we used an experimental design and assessed participants' physiological (i.e., heart rate) and psychological (i.e., self-report) stress reactions after inducing a breach. Our results underscore that a PCB is experienced as a stressful event. In addition, we find that social account timing influences heart rate recovery following a PCB. We discuss the theoretical and practical implications of our findings and offer recommendations for practitioners.

The ups and downs of the week: A person-centered approach to the relationship between time pressure trajectories and well-being.

This study extends previous research on time pressure and well-being by investigating the relevance of distinct time pressure trajectories for indicators of well-being at the end of the working week and start of the next week. Drawing on the Effort-Recovery Model and Conservation of Resources theory, we applied latent class growth analyses and a manual stepwise Bolck-Croon-Hagenaar approach to examine (a) which latent classes of time pressure trajectories occur for employees and (b) how these classes differ from each other regarding indicators of well-being at the end of the working week and the following Monday. Using data on 254 employees in a daily diary study across five consecutive workdays, the findings revealed a four-class solution characterized by qualitatively different time pressure trajectories: a low stable time pressure trajectory and three trajectories with changing time pressure levels (high unstable, medium unstable, and increasing unstable time pressure). Further, the trajectories exhibited class-specific differences in Friday evening and Monday morning positive valence, calmness, and energetic arousal, in addition to Friday night sleep quality. The results indicated that not only did the level of time pressure matter regarding well-being but also the temporal pattern of change across one working week. The present article provides a first step towards understanding different temporal dynamics of time pressure and their relationship to well-being. Additionally, the findings are discussed from the perspective of resource loss and gain, providing practical recommendations for job design, leadership behavior, as well as individual coping with job demands. (PsycInfo Database Record (c) 2022 APA, all rights reserved).