Aims and objectives
This study aimed to portray the prevalence and associated factors of psychological distress among frontline nurses during COVID‐19 outbreak.
Background
The COVID‐19 outbreak has ...posed great threat to public health worldwide. Nurses fighting against the epidemic on the frontline might be under great physical and psychological distress. This psychological distress was predominantly described as sleep disturbance, symptoms of anxiety and depression, post‐traumatic stress, inability to make decisions and even somatic symptoms.
Design
Cross‐sectional study.
Methods
Frontline nurses from designated hospitals for COVID‐19 patients were invited to complete an online survey by convenience sampling, and the survey included six main sections: the General Health Questionnaire, the Perceived Social Support Scale, the Simplified Coping Style Scale, the Impact of Event Scale‐Revised, socio‐demographic, occupation and work history. Multiple logistic analysis was used to identify the potential risk factors of psychological distress. The study methods were compliant with the STROBE checklist.
Results
Of the 263 frontline nurses, 66 (25.1%) were identified as psychological distress. Multiple logistic analysis revealed that working in emergency department, concern for family, being treated differently, negative coping style and COVID‐19‐related stress symptom were positive related to psychological distress. Perceived more social support and effective precautionary measures were negatively associated with psychological distress.
Conclusions
The study demonstrated that COVID‐19 had a significant psychological impact on frontline nurses. Early detection of psychological distress and supportive intervention should be taken according to the associated factors to prevent more serious psychological impact on frontline nurses.
Relevance to clinical practice
This study highlighted that the frontline nurses were suffering from varying degrees of psychological distress, which needed early screening and supportive intervention for preventing more serious psychological impact on frontline nurses. Beside, more specific measurement should be combined with the GHQ‐12 to assess the varying degrees of psychological distress in frontline nurses.
All‐polymer solar cells (all‐PSCs) have attracted immense attention in recent years due to their advantages of tunable absorption spectra and electronic energy levels for both donor and acceptor ...polymers, as well as their superior thermal and mechanical stability. The exploration of the novel n‐type conjugated polymers (CPs), especially based on aromatic diimide (ADI), plays a vital role in the further improvement of power conversion efficiency (PCE) of all‐PSCs. Here, recent progress in structure modification of ADIs including naphthalene diimide (NDI), perylene diimide (PDI), and corresponding derivatives is reviewed, and the structure–property relationships of ADI‐based CPs are revealed.
Aromatic‐diimide‐based polymers have emerged as the most promising n‐type semiconductors and their photovoltaic performance has been significantly improved in the past decade. The recent exciting progress is highlighted and the structure–property relationship of aromatic‐diimde‐based photovoltaic polymers is revealed, which could provide important guidelines for the further design of n‐type photovoltaic polymers.
Direction of arrival (DOA) estimation for coprime multiple-input multiple-output radar is studied, and a combined unitary estimation of signal parameters via rotational invariance technique ...(ESPRIT)-based algorithm is proposed. The transmitter and the receiver adopt coprime arrays, which are sparse but still uniform. Therefore, unitary ESPRIT is first used to obtain arbitrary ambiguous DOA estimations based on the rotational invariances of transmit and receive arrays, respectively. After recovering all the other estimations, unique DOA estimation is achieved by finding the coincide results from transmit and receive arrays based on the coprimeness. The proposed algorithm obtains more accurate DOA estimation, achieves higher angle resolution, and identifies more targets than conventional methods. Multiple simulations are conducted to verify the improvement of the proposed algorithm.
Direction of arrival (DOA) estimation using coprime array is studied, and an extended-aperture unitary root multiple signal classification (MUSIC)-based method is proposed. The geometry of prototype ...coprime array is modified through some translations, which enable one subarray of the coprime array to achieve aperture extension after unitary transformation. Then, the aperture of the other subarray can also be extended based on the rotational invariance of the extended subarray, and 2-D parameter estimations from the two extended subarrays can be achieved in succession via 1-D root MUSIC-based technique. Finally, unique DOA is determined from the intersection of the two automatically paired and coprime estimations. In contrast to the partial search MUSIC method, the estimation of signal parameters via rotational invariance technique based method, the root MUSIC-based method, and the real-valued cross covariance matrix based method, the proposed method gives better DOA estimation results and manages more sources. Furthermore, it has low complexity for the real-valued decomposition. Simulation results verify the improvement of the proposed approach.
Agricultural field burning plays an important role in atmospheric pollution and climate change. This work aims to develop a detailed emission inventory for agricultural burning in China with a high ...spatial and temporal resolution. Province-specific statistical data, distributed by the Chinese national government, and results from scientific literature were utilized to estimate the total emissions for the base year 2006. Emissions were allocated to a 1 km grid and a 10-day interval by using the Moderate Resolution Imaging Spectroradiometer (MODIS) Thermal Anomalies/Fire product (MOD/MYD14A1). The estimated annual emission ranges, with a 90% confidence interval, are 68 (51–85) Tg CO2 yr−1, 4 (2–7) Tg CO yr−1, 0.25 (0.08–0.46) Tg CH4 yr−1, 2.2 (1.08–3.46) Tg NMOCs yr−1, 0.23 (0.08–0.41) Tg NOx yr−1, 0.09 (0.03–0.17) Tg NH3 yr−1, 0.02 (0.01–0.03) Tg SO2 yr−1, 0.03 (0.01–0.05) Tg BC yr−1, 0.1 (0.04–0.17) Tg OC yr−1, 0.27 (0.13–0.42) Tg PM2.5 yr−1, 0.31 (0.12–0.53) Tg PM10 yr−1. Provinces with the highest emissions are Anhui, Guizhou and Hunan. Spatially, agricultural fires are mostly located in the North China Plain, where the occurrence of fires is concentrated in early and late June (over 75% of the whole year) with another smaller peak in early October. This pattern corresponds with sowing and harvesting times for the main crops: wheat and maize. The temporal fire variation of two other agricultural zones in northeast China and south China are also detailed in our study. Our inventory, with a relatively high spatiotemporal resolution (1 km grid and 10 days), could meet the need of global and regional air quality simulations.
► Emission estimation for crop residue field burning in China. ► Relatively high spatiotemporal resolution: 1 km and 10 days. ► 8-year MODIS Thermal Anomalies/Fire products were used to allocate the emissions. ► Detailed discussion of spatiotemporal distribution of agricultural open fire.
Hydrosilylation of alkynes generally yield vinylsilanes, which are inert to the further hydrosilylation because of the steric effects. Reported here is the first successful dihydrosilylation of aryl‐ ...and silyl‐substituted internal alkynes enabled by a rare‐earth ate complex to yield geminal bis‐ and tris(silanes), respectively. The lanthanum bis(amido) ate complex supported by an ene‐diamido ligand proved to be the ideal catalyst for this unprecedented transformation, while the same series of yttrium and samarium alkyl and samarium bis(amido) ate complexes exhibited poor activity and selectivity, indicating significant effects of the ionic size and ate structure of the rare‐earth catalysts.
Big metal magic: Dihydrosilylation of aryl‐ and silyl‐substituted internal alkynes is successfully achieved by a lanthanum bis(amido) ate complex to yield geminal bis‐ and tris(silanes), respectively. The high activity could be attributed to the large lanthanum ion and anionic nature of the catalyst.
Black phosphorus (BP) as a novel class of two-dimension (2D) materials has recently attracted enormous attention as a result of its unique physical and chemical features. The remarkably strong ...light-matter interaction and tunable direct band-gap at a wide range make it an ideal candidate especially in the mid-infrared wavelength region as the saturable absorber (SA). In this paper, the simple and effective liquid phase exfoliation (LPE) method was used to fabricate BP. By introducing the same BP SA into two specifically designed rare earth ions doped fluoride fiber lasers at mid-infrared wavebands, Q-switching with the pulse energy of 4.93 μJ and mode-locking with the pulse duration of 8.6 ps were obtained, respectively. The operation wavelength of ~2970 nm for generated pulse is the reported longest wavelength for BP SA based fiber lasers.
It is of great importance to understand the origin of high oxygen-evolving activity of state-of-the-art multimetal oxides/(oxy)hydroxides at atomic level. Herein we report an evident improvement of ...oxygen evolution reaction activity via incorporating iron and vanadium into nickel hydroxide lattices. X-ray photoelectron/absorption spectroscopies reveal the synergistic interaction between iron/vanadium dopants and nickel in the host matrix, which subtly modulates local coordination environments and electronic structures of the iron/vanadium/nickel cations. Further, in-situ X-ray absorption spectroscopic analyses manifest contraction of metal-oxygen bond lengths in the activated catalyst, with a short vanadium-oxygen bond distance. Density functional theory calculations indicate that the vanadium site of the iron/vanadium co-doped nickel (oxy)hydroxide gives near-optimal binding energies of oxygen evolution reaction intermediates and has lower overpotential compared with nickel and iron sites. These findings suggest that the doped vanadium with distorted geometric and disturbed electronic structures makes crucial contribution to high activity of the trimetallic catalyst.
The growing season normalized difference vegetation index (NDVIGS) of vegetation and their responses to climate extremes are critical in assessing the resistance and resilience of the terrestrial ...ecosystem. Using satellite-derived NDVIGS and widely used Standardized Precipitation and Evapotranspiration Index (SPEI) datasets of 18 sites in cold steppe, humid temperate and temperate dry steppe ecoregions for the period of 1982–2012, the NDVIGS response, resistance, and resilience to climate extreme intensity were assessed. The results showed that the mean NDVIGS varied significantly across ecoregions, where higher mean NDVIGS was observed in humid temperate and lower was in temperate dry steppe. The NDVIGS at most sites in three ecoregions showed significantly positive correlations with increasing SPEI. The responses of NDVIGS to climate extreme intensity revealed that moderate and extreme dry events decreased NDVIGS, while moderate and extreme wet events increased NDVIGS in all ecoregions. The results showed that vegetation resistance and resilience were highly dependent on climate extreme intensity. Resistance and resilience to moderate wet, extreme wet, moderate dry and extreme dry events in all ecoregions varied significantly, where vegetation in cold steppe and humid temperate ecoregions showed lower resistance but higher resilience to moderate and extreme dry events, and higher resistance but lower resilience to moderate and extreme wet events. Vegetation in temperate dry steppe showed higher resistance to moderate dry and higher resilience to moderate wet events. The study results suggest that more productive ecosystems (i.e. higher NDVIGS in cold steppe and humid temperate ecoregions) generally provide a lower (higher) resistance but higher (lower) resilience to dry (wet) events. Knowledge from this study also implies that less productive ecosystem (i.e. lower NDVIGS in temperate dry steppe) provides higher resistance to moderate dry and higher resilience after moderate wet events. This study highlights the impacts of climate extremes on NDVIGS, and improves our understanding of the resistance and resilience of vegetation to climate extreme intensity, which is of importance in the face of climate change.
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•Mean NDVIGS was highest in humid temperate and lowest in temperate dry steppe.•Growing-season climate was the better predictor of NDVIGS than the annual climate.•Across ecoregions, significant loss (gain) of NDVIGS resulted from extreme dry (wet) events.•Productive ecosystems showed lower (higher) resistance but higher (lower) resilience to dry (wet) events.•In temperate dry steppe, vegetation showed higher resistance (resilience) to moderate dry (wet) events.
ABSTRACT
This study examines the temporal variations and spatial distributions of annual precipitation over Central Asia during the periods of 1901–2013, 1951–2013, and 1979–2013 using the latest ...version of Global Precipitation Climatology Centre (GPCC) full data reanalysis version 7 (GPCC V7) data set. The linear trend and multiperiods of the precipitation over the entire region and plain and mountainous area separately are analysed by linear least square method and ensemble empirical mode decomposition method. An overall increasing trend 0.66 mm (10 years)−1 is found for the entire region during 1901–2013, which is smaller than that of 1951–2013. The regional annual precipitation exhibits multi‐decadal variations, with a sharp decline during 1901–1944, followed by an increase until 1980s, and a fluctuation thereafter. During 1979–2013, the mountainous area shows a greater increasing trend than the entire region. Furthermore, the regional annual precipitation has exhibited high‐frequency variations with 3‐year and 6‐year quasiperiods and a low‐frequency variation with 28‐year quasiperiods. In terms of the spatial distribution, increasing trend in the annual precipitation is found in Xinjiang and decreasing trends appear over the five countries of Central Asia during 1951–2013. Empirical orthogonal function results show that the mountainous area is the large variability centre of the annual precipitation. The dominant mode of interannual variability in Central Asia annual precipitation is related to El Niño‐Southern Oscillation, which explains about 17% of the interannual variance during 1951–2013. The results of this study describe the long‐term variation in the annual precipitation over Central Asia as well as its relationship with some key climate indices in great detail, which will benefit the understanding and the prediction of the climate variations in this region.
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