Search

Background and Objectives : Scuba divers often experience persistent inert gas narcosis (IGN) even after surfacing. This study aimed to test the hypothesis that breathing oxygen (O 2 ) before surfacing can reduce postdive IGN. Materials and Methods : A group of 58 experienced divers underwent a 5 min dive at a depth of 50 m in a multi-place hyperbaric chamber. They were decompressed using air (air group). Another group of 28 divers (O 2 group) breathed 100% O 2 during the end of decompression. Prior to and after the dive, all participants performed the Sharpened Romberg test (SRT) and a modified tweezers test. Results : In the air group, the number of positive SRT results increased postdive (47% vs. 67%), indicating a greater impairment in the vestibular system (Cohen's d = 0.41). In the O 2 group, the percentage of positive SRT results remained constant at 68% both before and after the dive. In terms of the modified tweezers test, the air group showed no significant change in the number of picked beads (40 ± 9 vs. 39 ± 7), while the O 2 group demonstrated an increase (36 ± 7 vs. 44 ± 10) (Cohen's d = 0.34). Conclusion : The results reveal that the SRT revealed a negative effect of nitrogen (N 2 ) on the vestibular system in the air group. The increased number of beads picked in the O 2 group can be attributed to the learning effect, which was hindered in the air group. Consistent with our hypothesis, breathing O 2 during decompression appears to reduce postdive IGN.

Psychosocial stress is widespread worldwide and particularly affects young adults. There is a close and bidirectional relationship between sleep quality and mental health. Sleep duration, which is an important feature of sleep quality, shows both intra-individual variations and inter-individual differences. Internal clocks control individual sleep timing, which, in turn, defines the chronotype. On workdays, however, the end and duration of sleep are largely limited by external factors, such as alarm clocks, especially in later chronotypes. The aim of this study is to investigate whether there is a relationship between sleep timing and duration on workdays and measures for psychosocial stress, such as anxiety and depression; subjective workload; and the subjective impact of a high workload on sleep. We used a combination of Fitbit wearable actigraphy data and a questionnaire survey of young, healthy medical students and calculated correlations between the respective variables. We found that a shorter sleep duration on workdays is associated with a higher subjective workload and a higher subjective impact of a high workload on sleep, which, in turn, are associated with higher measures of anxiety and depression. Our study contributes to understanding the importance of sleep timing/duration and their regularity on weekdays for subjectively perceived psychosocial stress.

The critical flicker fusion frequency (cFFF) refers to the frequency at which a regularly recurring change of light stimuli is perceived as steady. The cFFF threshold is often assessed in clinics to evaluate the temporal characteristics of the visual system, making it a common test for eye diseases. Additionally, it serves as a helpful diagnostic tool for various neurological and internal diseases. In the field of diving/hyperbaric medicine, cFFF has been utilized to determine alertness and cognitive functions. Changes in the cFFF threshold have been linked to the influence of increased respiratory gas partial pressures, although there exist inconsistent results regarding this effect. Moreover, the use of flicker devices has produced mixed outcomes in previous studies. This narrative review aims to explore confounding factors that may affect the accuracy of cFFF threshold measurements, particularly in open-field studies. We identify five broad categories of such factors, including (1) participant characteristics, (2) optical factors, (3) smoking/drug use, (4) environmental aspects, and (5) breathing gases and partial pressures. We also discuss the application of cFFF measurements in the field of diving and hyperbaric medicine. In addition, we provide recommendations for interpreting changes in the cFFF threshold and how they are reported in research studies.

Emerging virus diseases present a global threat to public health. To detect viral pathogens in time-critical scenarios, accurate and fast diagnostic assays are required. Such assays can now be established using mass spectrometry-based targeted proteomics, by which viral proteins can be rapidly detected from complex samples down to the strain-level with high sensitivity and reproducibility. Developing such targeted assays involves tedious steps of peptide candidate selection, peptide synthesis, and assay optimization. Peptide selection requires extensive preprocessing by comparing candidate peptides against a large search space of background proteins. Here we present Purple (Picking unique relevant peptides for viral experiments), a software tool for selecting target-specific peptide candidates directly from given proteome sequence data. It comes with an intuitive graphical user interface, various parameter options and a threshold-based filtering strategy for homologous sequences. Purple enables peptide candidate selection across various taxonomic levels and filtering against backgrounds of varying complexity. Its functionality is demonstrated using data from different virus species and strains. Our software enables to build taxon-specific targeted assays and paves the way to time-efficient and robust viral diagnostics using targeted proteomics., Competing Interests: The authors declare no conflicts of interest.

Medical students are at increased risk of experiencing mental health problems. Certain personality traits may be associated with elevated vulnerability to study-related stress and poor mental health. This study aimed to investigate the relationship between such personality traits and mental health outcomes among medical students. We drew on cross-sectional data from 251 medical students who had been enrolled for one-year at a medical school in Germany. Depressive symptoms were measured using the Patient Health Questionnaire-8 (PHQ-8) and suicidal ideation was assessed by item 9 from the Patient Health Questionnaire-9 (PHQ-9). Personality traits were captured using the Business-Focused Inventory of Personality 6 Factors (BIP-6F). Multivariable logistic regression analyses were used to quantify the associations between work-related personality factors and mental health outcomes, controlling for demographic and social factors. Odds ratios (ORs) as outcome measures with 95% confidence intervals (CIs) were used. After controlling for important confounders, medical students who scored highly on Stability had lower odds of depressive symptoms (OR: 0.19, 95% CI: 0.09⁻0.42, p < 0.001) and suicidality (OR: 0.38, 95% CI: 0.16⁻0.87, p < 0.05) than those with high scores in other work-related personality factors. Findings also showed that those who scored highly on Dominance had greater odds of depressive symptoms (OR: 2.46, 95% CI: 1.22⁻4.97), p < 0.01). Work-related personality-informed interventions, which promote students' mental well-being and reduce academic stress should be considered at various stages of their medical training.