The mediating effect of resilience and COVID-19 anxiety on the relationship between social support and insomnia among healthcare workers: a cross-sectional study

BackgroundInsomnia in healthcare workers has become a topic of concern in the health system. The high infectivity and longevity of the COVID-19 pandemic have resulted in great pressure and a high incidence of insomnia among healthcare workers. Insomnia among healthcare workers has a negative impact on high-quality healthcare services in addition to their health. Thus, it's necessary to explore insomnia's underlying mechanisms.ObjectThe present research's aims were threefold: explored the association between social support, resilience, COVID-19 anxiety, and insomnia among healthcare workers during the pandemic, elucidated the underlying mechanism of insomnia, and offered recommendations for improving the health of these workers.Materials and methodsA cross-sectional design was adopted. From May 20 to 30, 2022, 1038 healthcare workers were selected to fill out the Oslo 3-item Social Support Scale, the eight-item Athens Insomnia Scale, the Coronavirus Anxiety Scale, and the Brief Resilience Scale. Descriptive statistics and correlations were analyzed by SPSS 25.0. Mediation analysis was conducted by Mplus 8.3 using 5000 bootstrap samples.ResultsOf the participating 1038 healthcare workers, the prevalence of insomnia was 41.62% (432/1038). Significant associations were found involving insomnia, resilience, COVID-19 anxiety, and social support. Insomnia was directly affected by social support. Moreover, three indirect pathways explain how social support affected insomnia: resilience's mediating role, COVID-19 anxiety's mediating role, and the chain-mediation role of resilience and COVID-19 anxiety.ConclusionThe results validated our hypotheses and supported the opinion of Spielman et al. ‘s three-factor model of insomnia. Social support of healthcare workers has an indirect impact on insomnia in addition to its direct one via independent and chain-mediation effects of resilience and COVID-19 anxiety

Tunable Microwave Pulse Generation Based on an Actively Mode-Locked Optoelectronic Oscillator

A tunable microwave-pulse-generation scheme is proposed and demonstrated by employing an actively mode-locked optoelectronic oscillator (OEO) based on a microwave photonic filter (MPF). The MPF mainly consists of a phase-shifted fiber Bragg grating (PS-FBG) and a phase modulator. The microwave pulse trains with variable repetition rates are achieved by injecting an external signal, of which the frequencies are equal to an integer multiple of the free spectrum range (FSR) of the OEO. The multi-mode oscillation mechanism is discussed in detail theoretically and experimentally. A microwave pulse train with a central frequency of 9.25 GHz and repetition rate of 1.68 MHz is demonstrated by setting the injecting signal frequency to be the same with the FSR of the OEO. A tunable center frequency of the microwave pulses from 5.47 GHz to 18.91 GHz can be easily generated by tuning the laser frequency benefit from adopting the MPF. Furthermore, the microwave pulses with different pulse periods of 297.62 ns, 198.69 ns, and 148.81 ns are also realized by harmonic mode-locking. The proposed tunable microwave-pulse-generation method has potential applications in the pulse Doppler radar and communications

Psychometric properties of the Coronavirus Anxiety Scale based on Classical Test Theory (CTT) and Item Response Theory (IRT) models among Chinese front-line healthcare workers

Abstract Background Since March 2022, the COVID-19 epidemic has rebounded widely and frequently in China. Healthcare workers have faced grand challenges such as soaring COVID-19 patients, being busy with the nucleic acid screening of all the populations in the epidemic areas every day, and testing positive for COVID-19, all of which contributed to anxiety easily according to the Conservation of Resources theory. However, anxiety among healthcare workers is not only associated with personal health but also adversely affects the quality of health services. Therefore, it is crucial to search for suitable tools to monitor the anxiety related to COVID-19 among healthcare workers. The current study aimed to test the Coronavirus Anxiety Scale (CAS) in Chinese healthcare workers. Methods The current study employed a cross-sectional design. The CAS was translated into Chinese. Then, according to Classical Test Theory (CTT) and Item Response Theory (IRT) models, the psychometric properties of the Chinese version were measured among 811 healthcare workers. Results The split‐half reliability was 0.855. The Cronbach’s α coefficient was 0.895. The retest coefficient was 0.901 with 10 days as the retest interval. The content validity index was 0.920. In exploratory factor analysis, one common factor was extracted and explained 72.559% of the total variance. All item load values on the common factor ranged from 0.790 to 0.885, and the communality of each item ranged from 0.625 to 0.784. With confirmatory factor analysis, the single factor model showed an excellent goodness-of-fit, chi-square/degree of freedom (χ 2 /df) = 3.339, goodness of fit index (GFI) = 0.992, adjusted goodness of fit index (AGFI) = 0.975, root-mean-square error of approximation (RMSEA) = 0.054, root mean square residual (RMR) = 0.005, incremental fit index (IFI) = 0.967, Tucker-Lewis index (TLI) = 0.932, and comparative fit index (CFI) = 0.966. The multiple-group confirmatory factor analysis revealed the invariance measuring anxiety of COVID-19 was in similar ways across ages, hospital degrees, and professional titles. With convergent validity, the CAS was positively correlated with post-traumatic stress disorder (r = 0.619, P < 0.001), fear of COVID (r = 0.550, P < 0.001), and depression (r = 0.367, P < 0.001). According to IRT models, the results showed that all item discrimination parameters were higher than 1.70 and difficulty parameters ranged from 1.13 to 2.83. Conclusion The Chinese version of CAS has good psychometric properties in healthcare workers after China adjusted the COVID-19 management measures during the COVID-19 Omicron epidemic, and can be used for assessing the anxiety associated with COVID-19 in Chinese healthcare workers

Data for: Bremsstrahlung emission and plasma characterization driven by moderately relativistic laser–plasma interactions

Relativistic electrons generated by the interaction of petawatt-class short laser pulses with solid targets can be used to generate bright x-rays via bremsstrahlung. The efficiency of laser energy transfer into these electrons depends on multiple parameters including the focused intensity and pre-plasma level. This paper reports experimental results from the interaction of a high intensity petawatt-class glass laser pulses with solid targets at a maximum intensity of 1019 W cm−2. In-situ measurements of specularly reflected light are used to provide an upper bound of laser absorption and to characterize focused laser intensity, the pre-plasma level and the generation mechanism of second harmonic light. The measured spectrum of electrons and bremsstrahlung radiation provide information about the efficiency of laser energy transfer