Trajectories and influencing factors in adolescent procrastination behavior throughout the COVID-19 pandemic: a four-wave prospective longitudinal study.

Background: Despite the growing attention given to adolescent behavior problems, little is known about the trajectories and factors that have influenced adolescent procrastination during the COVID-19 pandemic. This study monitors changes in procrastination behavior among Chinese adolescents during the pandemic and identifies vulnerable groups. Methods: A four-wave study using a representative sample of 11-to 18-year-olds in China was conducted, with baseline data collected in June 2020 (n = 4,156; 49% girls) and follow-ups in December 2020 (n = 3,392; 50% girls), August 2021 (n = 2,380; 48% girls), and October 2021 (n = 1,485; 49% girls). Procrastination behavior was assessed using the General Procrastination Scale. Latent growth curve models, latent growth mixture modes, and multivariate logistic regression models were used to describe the trajectory of procrastination and identify predictors of deterioration. Results: The proportion and overall trends of adolescent procrastination increased with the pandemic. Higher parental over-protection was a contributing factor to the higher baseline levels leading to the faster growth of adolescent procrastination. The model identified three distinct trajectories of low-increasing [including 2,057 participants (49.5%)], moderate-stable [including 1,879 participants (45.2%)], and high-decreasing procrastination [including 220 participants (5.3%)]. More daily leisure screen-time, lower frequency of exercise weekly, and dissatisfaction with distance learning were the top three risk factors for moderate-stable and high-decreasing procrastination compared to low-increasing procrastination. Adolescents with mothers with a higher level of education were more liable to be high-decreasing procrastination than moderate-stable procrastination. Conclusion: The proportion and overall trends of adolescent procrastination increased with the pandemic. The categories of procrastination among adolescents during that time period were probed. Also, the study further clarified the risk factors for severe and moderate procrastination relative to no procrastination. Thus, effective procrastination prevention and intervention strategies need to be implemented to support adolescents, particularly those at risk.

Relationship between psychological capital and depression in Chinese physicians: The mediating role of organizational commitment and coping style.

Background: It is well known that the medical profession is a high-risk practice, with intense work and complex situations. The physicians are prone to suffer from depression due to occupational stress under high workloads for long periods of time. Depression not only impairs physicians' mental health, but also affects the quality of health services, so it is important to explore the factors and mechanisms affecting depression among physicians. Methods: In this cross-sectional study, 1,139 physicians from Heilongjiang Province were surveyed by cluster sampling procedures. The questionnaires included Psychological Capital Questionnaire, Chinese Employee Organizational Commitment Questionnaire, Trait Coping Style Questionnaire and Self-rating Depression Scale. Pearson correlation analysis and Bootstrap were used for statistical analysis. Results: This study found that 41.6% of physicians suffering from depression. Among them, 17.0% of physicians showed moderate depression, and 2.6% of physicians exhibited severe depression. The serial-multiple mediation of organizational commitment and positive coping styles in the relationship between psychological capital and depression was significant. Conclusion: The results showed that the psychological capital was sequentially associated with increased organizational commitment, and then increased positive coping styles, which resulted in reduced depression among physicians.

Serum soluble DR5 predicts mortality risk in patients with HBV-related hepatocellular carcinoma.

Introduction: Death receptor 5 (DR5) is significantly upregulated in various human tumor tissues; however, the relationship between serum levels of soluble DR5 (sDR5) and the mortality risk of hepatocellular carcinoma (HCC) is not understood. Our aim is to investigate the prognostic value of serum sDR5 in HCC patients. Methods: A total of 170 patients with HBV-HCC were recruited, with 82 and 88 patients as derivation and validation cohorts, respectively. sDR5 levels were analyzed using ELISA. The predictive factors for mortality were selected using LASSO regression analysis. Cox regression analysis was used to analyze the independent factors affecting mortality in 2 years. A nomogram based on the interquartile range of the sDR5 values predicted mortality rates. Results: Serum sDR5 level was identified as an independent risk factor for mortality in patients with HBV-HCC. The 2-year cumulative mortality rates of HBV-HCC were 10, 28.57, 38.10, and 95% across the sDR5 quartiles, respectively (p < 0.001). The sDR5 had an AUROC of 0.851 (95% CI: 0.755-0.920) in the derivation cohort. When the cut-off value was 30.06pg/mL, the AUROC of sDR5 was 0.778 (95% CI 0.677-0.860) in the validation cohort. The calibration curves fit well, and the decision curves showed that sDR5 had a high standardized net benefit. sDR5 predicted the prognosis of HBV-HCC patients most accurately. Further, serum sDR5 level was significantly positively associated with BCLC stage and the presence or absence of ascites. Conclusion: sDR5 showed high predictive accuracy in patients with HBV-HCC; thus, it is considered a new serological biomarker.

Bioavailability and toxicity of silver nanoparticles: Determination based on toxicokinetic-toxicodynamic processes.

Determining the bioavailability and toxicity mechanism of silver nanoparticles (AgNPs) is challenging as Ag+ is continuously released by external or internal AgNP dissolution in the actual exposure system (regardless of the laboratory or the natural environment). Here a novel pulsed-gradient Ag+ (AgNO3) exposure was conducted with zebrafish (Danio rerio) larvae to simulate dissolved gradient concentrations of Ag+ from polyvinylpyrrolidone (PVP)-coated AgNPs. The accumulation and toxicity of the pulsed-gradient Ag+ (AgNO3) and, in the meantime, the released Ag+ from PVP-AgNPs were predicted using a toxicokinetic-toxicodynamic (TK-TD) model with obtained Ag+ parameters. In order to further understand the possible mechanism of PVP-AgNP releasing Ag+ in the body, subcellular fractions (S9) of zebrafish were also used to incubate with AgNPs in vitro to mimic the realistic in vivo scenarios. In the TK process, in vivo analysis showed that AgNPs released around twice as many Ag+ into the body than were detected with a single Ag+ pulse-exposure system; this was supported by evidence that subcellular S9 fractions might cause the PVP-AgNPs to lose the capping agent and favor Ag+ release. In the TD process, toxicity (survival rate) was predicted by the total bodily Ag(I) concentration, suggesting that AgNP toxicity in larvae was mainly due to gradually released Ag+ rather than AgNPs themselves. This study helps clarify the role of Ag+ in AgNP toxicity and offers a novel framework by which to investigate the toxicity of metal nanoparticles and corresponding metal ions in biological systems.

Phosphonium-based deep eutectic solvent coupled with vortex-assisted liquid-liquid microextraction for the determination of benzoylurea insecticides in olive oil.

In this study, a novel method using a phosphonium-based deep eutectic solvent coupled with vortex-assisted liquid-liquid microextraction was investigated for the enrichment and separation of five benzoylurea insecticides in olive oil. The experimental factors affecting the extraction efficiency, including the extractant type, deep eutectic solvent volume, extraction time, and extraction mode, were optimized. Under optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r) ranging from 0.9971 to 0.9998; the limits of detection were in the range of 1.5 to 7.5 µg/L, and the recoveries of analytes using the proposed method ranged between 66.9 and 111.0%. The simple, rapid, and effective method was successfully applied for detecting target analytes in olive oil sample.

Dispersive micro-solid phase extraction based on a graphene/polydopamine composite for the detection of pyrethroids in water samples.

In this study, a simple, rapid, precise, and environmentally friendly microextraction named dispersive micro-solid phase extraction based on a graphene/polydopamine composite as a sorbent was investigated for the analysis of four pyrethroids (fenpropathrin, cyhalothrin, etofenprox and bifenthrin) in water samples. The graphene/polydopamine composite was successfully synthesized using a one-step method, and was characterized by scanning electron microscopy, transmission electron microscopy, energy-dispersive spectroscopy and X-ray photoelectron spectroscopy. The simplicity and rapidity of dispersive micro-solid phase extraction and the high surface area and adsorptivity of the graphene/polydopamine composite were combined in the proposed method. Several main parameters, including the amount of the sorbent, extraction time, ionic strength and desorption conditions, were independently optimized and the results were compared to find the best extraction setup for dispersive micro-solid phase extraction. Under the optimal conditions, good linearity was observed for all the target analytes, with the coefficient of determination ranging from 0.9997 to 0.9999. The extraction recoveries obtained using the proposed method ranged from 76.81% to 85.29%, and the limits of detection varied from 1.5 to 3 µg L-1. In addition, the relative standard deviation values for the intra-day precision were between 0.41% and 3.00%, while the inter-day precision showed relative standard deviation values ranging from 1.61% to 5.59%. Overall, the figures of merit of the entire procedure showed that this technique could produce satisfactory results in the detection of pyrethroids in water samples or other organic pollutants in the future.

Preparation of a magnetic graphene/polydopamine nanocomposite for magnetic dispersive solid-phase extraction of benzoylurea insecticides in environmental water samples.

A magnetic graphene/polydopamine (MG/PDA) nanocomposite has been prepared and used as sorbent for magnetic dispersive solid-phase extraction (MDSPE) of four benzoylurea insecticides in environmental water samples. The obtained nanocomposites were characterized by transmission electron microscopy, scanning electron microscopy, vibrating sample magnetometry, powder X-ray diffraction, fourier transform infrared spectroscopy, surface area and porosity analysis and thermogravimetric analysis. To investigate the adsorption performance of MG/PDA for target analytes, various parameters affecting the MG/PDA-based MDSPE procedure were optimized. Under the optimal conditions, the established method exhibits good linearity (R2 ≥ 0.9988) in the concentration range 2.5-500 µg L-1. A low limit of detection (0.75 µg L-1, signal/noise = 3:1), a low limit of quantification (2.50 µg L-1, signal/noise = 10:1), and good precision (intraday relative standard deviation ≤3.6%, interday relative standard deviation ≤4.5%) are also achieved. Finally, the simple, fast, and sensitive sample preparation technique was successfully used to determine benzoylurea insecticides in environmental water samples.

Dispersive liquid-liquid microextraction based on the solidification of deep eutectic solvent for the determination of benzoylureas in environmental water samples.

We present a novel dispersive liquid-liquid microextraction method based on the solidification of deep eutectic solvent coupled with high-performance liquid chromatography with a variable-wavelength detection for the detection of five benzoylureas in real water samples. In this work, a green solvent consisting of 1-octyl-3-methylimidazolium chloride and 1-dodecanol was used as an extraction solvent, yielding the advantages of material stability, low density, and a suitable freezing point near room temperature. Parameters that significantly affect extraction efficiency were optimized by the one-factor-at-a-time approach. Under optimal conditions, the recoveries of five target compounds were obtained ranging from 87.39 to 98.05% with correlation coefficients ranging from 0.9994 to 0.9997 for pure water. The limits of detection were in the range of 0.09-0.16 µg/L. The enrichment factors were in the range of 171-188. Linearities were achieved in the range of 0.5-500 µg/L. The proposed method was successfully applied to determine benzoylureas in environmental water samples with a satisfactory recovery of approximately 81.38-97.67%.

Magnetic mixed hemimicelles dispersive solid-phase extraction based on ionic liquid-coated attapulgite/polyaniline-polypyrrole/Fe3O4 nanocomposites for determination of acaricides in fruit juice prior to high-performance liquid chromatography-diode array detection.

In this research, a novel method using magnetic mixed hemimicelles dispersive solid-phase extraction (MMHDSPE) based on C16mimBr-coated attapulgite/polyaniline-polypyrrole/Fe3O4 (ATP/PANI-PPY/Fe3O4) nanocomposites were investigated for enrichment and separation of three acaricides in fruit juice. In this method, we combined the simplicity and speed of dispersive solid-phase extraction, the advantages of mixed hemimicelles and the facility of the phase separation of the magnetic nanoparticles to develop a simple, rapid, sensitive, and effective method for detecting target analytes from the juice samples. ATP/PANI-PPY/Fe3O4 nanocomposites were successfully synthesized using a one-pot method. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The experimental factors affecting the extraction efficiency including the sorbent type, amount of ATP/PANI-PPY/Fe3O4 nanocomposites, volume of ILs, sonication time, pH, and desorption conditions were optimized. Under the optimal conditions, good linearity was observed for all target analytes, with correlation coefficients (r2) ranging from 0.9994 to 0.9999; the limits of detection (LOD) were in the range of 0.16-0.57µgL-1, and the recoveries of analytes using the proposed method ranged between 88.67% and 95.10%. The sorbents exhibited excellent repeatability in the range of 1.83-4.24% in extracting the three target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.19-6.24% and 2.23-8.36%, respectively. The method was successfully applied to analyze fruit juice samples by rapid preconcentration of acaricides.

Facile synthesis of multifunctional attapulgite/Fe3O4/polyaniline nanocomposites for magnetic dispersive solid phase extraction of benzoylurea insecticides in environmental water samples.

In this study, the superparamagnetic attapulgite/Fe3O4/polyaniline (ATP/Fe3O4/PANI) nanocomposites were successfully synthesized by a one-pot method. Fe (III) was applied as both the oxidant for the oxidative polymerization of aniline and the single iron source of Fe3O4 formed by the redox reaction between aniline and Fe (III). The ATP/Fe3O4/PANI was used as sorbent for magnetic dispersive solid phase extraction (MDSPE) of benzoylurea insecticides (BUs) in environmental water samples. The as-prepared nanocomposite sorbents were characterized by Fourier transform infrared spectra (FT-IR), X Ray diffraction (XRD), scanning electron microscopy(SEM), transmission electron microscopy (TEM), and vibrating sample magnetometry. Various experimental parameters affecting the ATP/Fe3O4/PANI-based MDSPE procedure, including the composition of the nanocomposite sorbents, amount of ATP/Fe3O4/PANI nanocomposites, vortex time, pH, and desorption conditions were investigated. Under the optimal conditions, a good linearity was observed for all target analytes, with correlation coefficients (r(2)) ranging from 0.9985 to 0.9997; the limits of detection (LOD) were in the range of 0.02-0.43 µg L(-1), and the recoveries of analytes using the proposed method ranged between 77.37% and 103.69%. The sorbents exhibited an excellent reproducibility in the range of 1.52-5.27% in extracting the five target analytes. In addition, the intra-day and inter-day precision values were found to be in the range of 0.78-6.86% and 1.66-8.41%, respectively. Finally, the proposed ATP/Fe3O4/PANI-based MDSPE method was successfully applied to analyze river water samples by rapid preconcentration of BUs.