We explored whether medical health workers had more psychosocial problems than nonmedical health workers during the COVID-19 outbreak.
An online survey was run from February 19 to March 6, 2020; a ...total of 2,182 Chinese subjects participated. Mental health variables were assessed via the Insomnia Severity Index (ISI), the Symptom Check List-revised (SCL-90-R), and the Patient Health Questionnaire-4 (PHQ-4), which included a 2-item anxiety scale and a 2-item depression scale (PHQ-2).
Compared with nonmedical health workers (n = 1,255), medical health workers (n = 927) had a higher prevalence of insomnia (38.4 vs. 30.5%, p < 0.01), anxiety (13.0 vs. 8.5%, p < 0.01), depression (12.2 vs. 9.5%; p< 0.04), somatization (1.6 vs. 0.4%; p < 0.01), and obsessive-compulsive symptoms (5.3 vs. 2.2%; p < 0.01). They also had higher total scores of ISI, GAD-2, PHQ-2, and SCL-90-R obsessive-compulsive symptoms (p ≤ 0.01). Among medical health workers, having organic disease was an independent factor for insomnia, anxiety, depression, somatization, and obsessive-compulsive symptoms (p < 0.05 or 0.01). Living in rural areas, being female, and being at risk of contact with COVID-19 patients were the most common risk factors for insomnia, anxiety, obsessive-compulsive symptoms, and depression (p < 0.01 or 0.05). Among nonmedical health workers, having organic disease was a risk factor for insomnia, depression, and obsessive-compulsive symptoms (p < 0.01 or 0.05).
During the COVID-19 outbreak, medical health workers had psychosocial problems and risk factors for developing them. They were in need of attention and recovery programs.
Organic single‐crystalline semiconductors with long‐range periodic order have attracted much attention for potential applications in electronic and optoelectronic devices due to their high carrier ...mobility, highly thermal stability, and low impurity content. Molecular doping has been proposed as a valuable strategy for improving the performance of organic semiconductors and semiconductor‐based devices. However, a fundamental understanding of the inherent doping mechanism is still a key challenge impeding its practical application. In this study, solid evidence for the “perfect” substitutional doping mechanism of the stacking mode between the guest and host molecules in organic single‐crystalline semiconductors using polarized photoluminescence spectrum measurements and first‐principles calculations is provided. The molecular host–guest doping is further exploited for efficient color‐tunable and even white organic single‐crystal‐based light‐emitting devices by controlling the doping concentration. The clarification of the molecular doping mechanism in organic single‐crystalline semiconductor host–guest system paves the way for their practical application in high‐performance electronic and optoelectronic devices.
A fundamental understanding of the molecular doping mechanism in organic single‐crystalline semiconductors is provided using polarized PL spectrum measurement and first‐principles calculations. Color‐tunable and white single‐crystal‐based organic light‐emitting devices with high performance are realized, which have important implications for the practical application of organic single‐crystalline semiconductors.
With growing concern over world environmental problems and increasing legislative restriction on using lead and lead-containing materials, a feasible replacement for lead-based piezoceramics is ...desperately needed. Herein, we report a large piezoelectric strain (d 33*) of 470 pm/V and a high Curie temperature (T c) of 243 °C in (Na0.5K0.5)NbO3-(Bi0.5Li0.5)TiO3-BaZrO3 lead-free ceramics by doping MnO2. Moreover, excellent temperature stability is also observed from room temperature to 170 °C (430 pm/V at 100 °C and 370 pm/V at 170 °C). Thermally stimulated depolarization currents (TSDC) analysis reveals the reduced defects and improved ferroelectricity in MnO2-doped piezoceramics from a macroscopic view. Local poling experiments and local switching spectroscopy piezoresponse force microscopy (SS-PFM) demonstrates the enhanced ferroelectricity and domain mobility from a microscopic view. Distinct grain growth and improvement in phase angle may also account for the enhancement of piezoelectric properties.
Covalent organic frameworks (COFs) have recently drawn intense attention due to their potential applications in photocatalysis. Herein, we report a multifunctional COF which consists of ...triphenylamine (TPA) and 2,2′‐bipyridine (2, 2′‐bipy) entities. The obtained TAPA−BPy−COF is a heterogeneous photocatalyst and can efficiently catalyze the oxidative coupling of thiols to disulfides. In addition, TAPA−BPy−COF can be further metalated by Pd(II) via 2,2′‐bipy−metal coordination. The generated Pd@TAPA−BPy−COF can highly promote photocatalytic synthesis of 3‐cyanopyridines via cascade addition/cyclization of arylboronic acids with γ‐ketodinitriles in heterogeneous way. This work has demonstrated the way for the rational design and preparation of more efficient photoactive COFs for photocatalysis.
A photoactive TAPA−BPy−COF and its metalated Pd@TAPA−BPy−COF, which can both serve as the efficient reusable photocatalysts for photocatalytic applications, are reported.
PbTe‐based alloys have been widely used as mid‐temperature thermoelectric (TE) materials since the 1960s. Years of endeavor spurred the tremendous advances in their TE performance. The breakthroughs ...for n‐type PbTe have been somewhat less impressive, which limits the overall conversion efficiency of a PbTe‐based TE device. In light of this obstacle, an n‐type Ga‐doped PbTe via an alternative thermodynamic route that relies on the equilibrium phase diagram and microstructural evolution is revisited. Herein, a plateau of zT = 1.2 is achieved in the best‐performing Ga0.02Pb0.98Te in the temperature range of 550–673 K. Notably, an extremely high average zTave = 1.01 is obtained within 300 − 673 K. The addition of gallium optimizes the carrier concentration and boosts the power factor PF = S2ρ−1. Meanwhile, the κL of Ga‐PbTe reveals a significantly decreasing tendency owing to the defect evolution that changes from dislocation loop to nano‐precipitation with increasing Ga content. The pathway for both the κL reduction and defect evolution can be probed by an equilibrium phase diagram, which opens up a new avenue for locating high zT TE materials.
A synergic approach, including defect engineering and carrier concentration optimization, to the fabrication of Ga‐doped PbTe thermoelectrics elicits reduced thermal conductivity and an enhanced power factor. It results in an extraordinary n‐type Ga0.02Pb0.98Te alloy, whose peak zT achieves 1.3 at 673 K. A phase diagram probes the best compositional region for the n‐type Ga‐PbTe alloys, in which the dislocation loop or nano‐precipitate forms.
Abstract
The detailed information on the surface structure and binding sites of oxide nanomaterials is crucial to understand the adsorption and catalytic processes and thus the key to develop better ...materials for related applications. However, experimental methods to reveal this information remain scarce. Here we show that
17
O solid-state nuclear magnetic resonance (NMR) spectroscopy can be used to identify specific surface sites active for CO
2
adsorption on MgO nanosheets. Two 3-coordinated bare surface oxygen sites, resonating at 39 and 42 ppm, are observed, but only the latter is involved in CO
2
adsorption. Double resonance NMR and density functional theory (DFT) calculations results prove that the difference between the two species is the close proximity to H, and CO
2
does not bind to the oxygen ions with a shorter O···H distance of approx. 3.0 Å. Extensions of this approach to explore adsorption processes on other oxide materials can be readily envisaged.
•Remote estimation of soil organic matter content (SOMC) in the Sanjiang Plain.•Optimal band algorithm (OBA) was developed for assessing SOMC using spectral data.•Grey relational analysis (GRA) was ...used to select the sensitive spectral parameters.•We compared the performance of proposed models using GRA-ANN and OBA.•Combining different algorithms may improve SOMC estimations on a regional scale.
Soil organic matter content (SOMC) is an important factor that reflects soil fertility, land production capacity, and the degree of soil degradation. The objectives of this study were to (i) test various regression models for estimating SOMC based on published spectral parameters in the Sanjiang Plain, (ii) develop optimal band difference, ratio, and normalized difference algorithms for assessing SOMC using spectral data, and (iii) compare the performance of the proposed models using grey relational analysis-artificial neural networks (GRA-ANN) and the band difference algorithm. The SOMC data and concurrent spectral parameters were acquired in the Sanjiang Plain of Northest China in 2006. For the GRA-ANN model, GRA was used to select the sensitive spectral parameters and ANN was established to estimate SOMC. The results showed that reflectance (R) gradually decreased with increasing SOMC and the regression equations based on the spectral parameter 1/R588, Diff (1/R835), R610, R654, R550, and R520 could be used to estimate SOMC, respectively. The SOMC model based on the optimal difference index (ODI; R2=0.63 and RMSE=1.43%) outperformed those based on the optimal ratio vegetation index (ORVI; R2=0.48 and RMSE=1.82%) and normalized difference vegetation index (ONDVI, R2=0.57 and RMSE=1.56%). The GRA-ANN model presented better SOMC estimation results (R2=0.90 and RMSE=0.88%). Thus, the GRA-ANN model has great potential for SOMC estimations; however, the ODI also has merit, especially when taking into consideration the simplicity of its application. Combining different algorithms may improve SOMC estimations on a regional scale.
There is a growing concern about the effects of nanoplastics on biological safety and human health because of their global ubiquity in the environment. Methodologies for quantitative analysis of ...nanoplastics are important for the critical evaluation of their possible risks. Herein, a sensitive yet simple and environmentally friendly extraction approach mediated by protein corona is developed and coupled to pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS) for nanoplastic determination in environmental waters. The developed methodology involved the formation of protein corona by addition of bovine serum albumin (BSA) to samples and protein precipitation via salting out. Then, the resulting extract was directly introduced to Py-GC/MS for nanoplastic mass quantification. Taking 50 nm polystyrene (PS) particles as a model, the highest extraction efficiency for nanoplastics was achieved under the extraction conditions of BSA concentration of 20 mg/L, equilibration time of 5 min, pH 3.0, 10% (w/v) NaCl, incubation temperature of 80 °C, and incubation period of 15 min. The extraction was confirmed to be mediated by the protein corona by transmission electron microscopy (TEM) analysis of the extracted nanoplastics. In total, 1.92 and 2.82 μg/L PS nanoplastics were detected in river water and the influent of wastewater treatment plant (WWTP), respectively. Furthermore, the feasibility of the present methodology was demonstrated by applying to extract PS and poly(methyl methacrylate) (PMMA) nanoplastics from real waters with recoveries of 72.1–98.9% at 14.2–50.4 μg/L spiked levels. Consequently, our method has provided new insights and possibilities for the investigation of nanoplastic pollution and its risk assessment in the environment.
Interactions of γ‐alumina with water are important in controlling its structure and catalytic properties. We apply solid‐state multinuclear NMR spectroscopy to investigate these interactions by ...monitoring 1H and 17O spectra in real‐time. Surface‐selective detection is made possible by adsorbing 17O‐enriched water on γ‐alumina nanorods. Structural evolution on the surface was selectively probed by 1H/17O double resonance NMR and 27Al NMR at ultrahigh 35.2 T magnetic field. Formation of hydroxyl species on the surface of nanorods is rapid upon the exposure of water, which involves low coordinated aluminum ions with doubly bridging and isolated hydroxyl species being generated first. Fast exchange occurs between oxygen atoms in the water molecules and bare surface sites, indicating high reactivity of these oxygen species. These results provide new insights into the structure and dynamics on the surface of γ‐alumina and the methods applied here can be extended to study the interaction of other oxides with water.
Solid‐state NMR: Time‐resolved multinuclear solid‐state NMR spectroscopy in combination with 27Al NMR spectroscopy at an ultrahigh magnetic field were used to investigate the interaction of γ‐ alumina with water.
Background and Aims
Trimethylation of Lys36 on histone 3 (H3K36me3) catalyzed by histone methyltransferase SET domain‐containing 2 (SETD2) is one of the most conserved epigenetic marks from yeast to ...mammals. SETD2 is frequently mutated in multiple cancers and acts as a tumor suppressor.
Approach and Results
Here, using a liver‐specific Setd2 depletion model, we found that Setd2 deficiency is sufficient to trigger spontaneous HCC. Meanwhile, Setd2 depletion significantly increased tumor and tumor size of a diethylnitrosamine‐induced HCC model. The mechanistic study showed that Setd2 suppresses HCC not only through modulating DNA damage response, but also by regulating lipid metabolism in the liver. Setd2 deficiency down‐regulated H3K36me3 enrichment and expression of cholesterol efflux genes and caused lipid accumulation. High‐fat diet enhanced lipid accumulation and promoted the development of HCC in Setd2‐deficient mice. Chromatin immunoprecipitation sequencing analysis further revealed that Setd2 depletion induced c‐Jun/activator protein 1 (AP‐1) activation in the liver, which was trigged by accumulated lipid. c‐Jun acts as an oncogene in HCC and functions through inhibiting p53 in Setd2‐deficient cells.
Conclusions
We revealed the roles of Setd2 in HCC and the underlying mechanisms in regulating cholesterol homeostasis and c‐Jun/AP‐1 signaling.
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