Computer adaptive testing (CAT) has been shown to shorten the test length and increase the precision of latent trait estimates. Oftentimes, test takers are asked to respond to several items that are ...related to the same passage. The purpose of this study is to explore three CAT item selection techniques for items of the same passages and to provide recommendations and guidance for item selection methods that yield better latent trait estimates. Using simulation, the study compared three models in CAT item selection with passages: (a) the testlet-effect model (T); (b) the passage model (P); and (c) the unidimensional IRT model (U). For the T model, the bifactor model with testlet-effect or constrained multidimensional IRT model was applied. For each of the three models, three procedures were applied: (a) no item exposure control; (b) item exposure control of rate 0.2 ; and (c) item exposure control of rate 1. It was found that the testlet-effect model performed better than passage or unidimensional models. The P and U models tended to overestimate the precision of the theta or latent trait estimates.
•Medical staff experience mental health disturb during the COVID-19 pandemic.•Direct and indirect exposure to COVID-19 affects the mental health profoundly.•Psychological materials and resources ...provide some protection.•Interventions with appropriate level are urgent.
The severe 2019 outbreak of novel coronavirus disease (COVID-19), which was first reported in Wuhan, would be expected to impact the mental health of local medical and nursing staff and thus lead them to seek help. However, those outcomes have yet to be established using epidemiological data. To explore the mental health status of medical and nursing staff and the efficacy, or lack thereof, of critically connecting psychological needs to receiving psychological care, we conducted a quantitative study. This is the first paper on the mental health of medical and nursing staff in Wuhan. Notably, among 994 medical and nursing staff working in Wuhan, 36.9% had subthreshold mental health disturbances (mean PHQ-9: 2.4), 34.4% had mild disturbances (mean PHQ-9: 5.4), 22.4% had moderate disturbances (mean PHQ-9: 9.0), and 6.2% had severe disturbance (mean PHQ-9: 15.1) in the immediate wake of the viral epidemic. The noted burden fell particularly heavily on young women. Of all participants, 36.3% had accessed psychological materials (such as books on mental health), 50.4% had accessed psychological resources available through media (such as online push messages on mental health self-help coping methods), and 17.5% had participated in counseling or psychotherapy. Trends in levels of psychological distress and factors such as exposure to infected people and psychological assistance were identified. Although staff accessed limited mental healthcare services, distressed staff nonetheless saw these services as important resources to alleviate acute mental health disturbances and improve their physical health perceptions. These findings emphasize the importance of being prepared to support frontline workers through mental health interventions at times of widespread crisis.
The construction of new semiconductor photocatalysts toward high-efficiency splitting water has played an important role in developing sustainable and clean hydrogen energy. In this work, new type of ...micro/nano-sized hybrids were synthesized based on the assembly of 0D Cd0.5Zn0.5S quantum dots (QDs, size: ca. 5nm) onto 2D graphitic carbon nitride (g-C3N4) ultrathin microribbons (thickness: ca. 4nm) via an in-situ growth hydrothermal method. The Cd0.5Zn0.5S 32wt%@C3N4 composite exhibits the highest visible-light-driven H2-generation rate of 33.41mmolh−1g−1 without any noble-metal as cocatalyst, and the apparent quantum efficiency is 46.65% at 450nm. Such H2-generation rate is higher than the pristine g-C3N4 and Cd0.5Zn0.5S by a factor of 27.39 and 9.18 respectively, which is significantly enhanced compared with most as-reported noble-metal-free semiconductor catalysts to date. In addition, compared with the pristine Cd0.5Zn0.5S, the photocatalytical stability of Cd0.5Zn0.5S QDs@C3N4 is highly improved. The enhanced H2-generation performance can be attributed to the well-matched energy level and strong electronic coupling between two components at the g-C3N4 interface as well as enhanced visible-light absorption. The uniform dispersion of Cd0.5Zn0.5S QDs onto the g-C3N4 ultrathin microribbons also facilitates the depression of electron-hole recombination from potential aggregation of Cd0.5Zn0.5S. Therefore, this work supplies an effective way to obtain promising 2D micro/nanostructures for high-efficiency visible light-induced H2-generation.
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•New type of g-C3N4 microribbons were synthesized vis pyrolysis, thermal exfoliation and liquid exfoliation process.•0D CdZnS quantum dots were localized on 2D g-C3N4 ultrathin microribbons, which show high efficient H2-generation under visible-light irritation without any noble-metal.•Compared with pure CdZnS, the composite photocatalyst of CdZnS quantum dots and g-C3N4 ultrathin microribbons displayed excellent photocatalytic stability.
Multidimensional computer adaptive testing (MCAT) can provide higher precision and reliability or reduce test length when compared with unidimensional CAT or with the paper-and-pencil test. This ...study compared five item selection procedures in the MCAT framework for both domain scores and overall scores through simulation by varying the structure of item pools, the population distribution of the simulees, the number of items selected, and the content area. The existing procedures such as Volume (Segall in Psychometrika, 61:331–354,
1996
), Kullback–Leibler information (Veldkamp & van der Linden in Psychometrika 67:575–588,
2002
), Minimize the error variance of the linear combination (van der Linden in J. Educ. Behav. Stat. 24:398–412,
1999
), and Minimum Angle (Reckase in Multidimensional item response theory, Springer, New York,
2009
) are compared to a new procedure, Minimize the error variance of the composite score with the optimized weight, proposed for the first time in this study. The intent is to find an item selection procedure that yields higher precisions for both the domain and composite abilities and a higher percentage of selected items from the item pool. The comparison is performed by examining the absolute bias,
correlation
,
test reliability
,
time used
, and
item usage
. Three sets of item pools are used with the item parameters estimated from real live CAT data. Results show that Volume and Minimum Angle performed similarly, balancing information for all content areas, while the other three procedures performed similarly, with a high precision for both domain and overall scores when selecting items with the required number of items for each domain. The new item selection procedure has the highest percentage of
item usage
. Moreover, for the overall score, it produces similar or even better results compared to those from the method that selects items favoring the general dimension using the general model (Segall in Psychometrika 66:79–97,
2001
); the general dimension method has low precision for the domain scores. In addition to the simulation study, the mathematical theories for certain procedures are derived. The theories are confirmed by the simulation applications.
A novel adsorbent of N-doped carbonized microspheres were developed from chitin (N-doped CM-chitin) for adsorption of Congo red (CR). The N-doped CM-chitin showed spherical shape and consisted of ...carbon nanofibers with 3D hierarchical architecture. There were many micro/nano-pores existing in N-doped CM-chitin with high surface area (455.703 m
g
). The N element was uniformly distributed on the carbon nanofibers and formed with oxidize-N graphitic-N, pyrrolic-N, and pyridinic-N. The N-doped CM-chitin showed excellent adsorption capability for CR and the maximum adsorption amount was approximate 954.47 mg g
. The π-π/n-π interaction, hydrogen-bond interactions, and pore filling adsorption might be the adsorption mechanisms. The adsorption of N-doped CM-chitin was considered as a spontaneous endothermic adsorption process, and which well conformed to the pseudo-second-order kinetic and Langmuir isotherm model. The N-doped CM-chitin exhibited an effective adsorption performance for dynamic CR water with good reusability. Therefore, this work provides new insights into the fabrication of a novel N-doped adsorbent from low-cost and waste biomasses.
This meta-analysis was conducted to estimate the overall association between maternal exposure to pesticides and risk of ASD in offspring. PubMed, EMBASE, Web of Science, and the PsycINFO were ...searched until December 30, 2020 to include eligible studies. Eight studies with 50,426 participants, 5810 of whom had ASD, were involved in the study. Overall, the summary OR (95% confidence interval) of ASDs in offspring for maternal exposure to pesticide estimated by residential proximity measures and self-report was 1.88 (1.10–3.20). However, maternal exposure to pesticide measured by biomarkers was not associated with an increased risk of ASDs (pooled OR 1.13; 95% CI 0.83–1.54). Further well-designed studies are needed to confirm our findings.
In educational assessment, overall scores obtained by simply averaging a number of domain scores are sometimes reported. However, simply averaging the domain scores ignores the fact that different ...domains have different score points, that scores from those domains are related, and that at different score points the relationship between overall score and domain score may be different. To report reliable and valid overall scores and domain scores, I investigated the performance of four methods using both real and simulation data: (a) the unidimensional IRT model; (b) the higher-order IRT model, which simultaneously estimates the overall ability and domain abilities; (c) the multidimensional IRT (MIRT) model, which estimates domain abilities and uses the maximum information method to obtain the overall ability; and (d) the bifactor general model. My findings suggest that the MIRT model not only provides reliable domain scores, but also produces reliable overall scores. The overall score from the MIRT maximum information method has the smallest standard error of measurement. In addition, unlike the other models, there is no linear relationship assumed between overall score and domain scores. Recommendations for sizes of correlations between domains and the number of items needed for reporting purposes are provided.
Major depressive disorder (MDD) is a common mental health disorder that brings severe disease burden worldwide. Traditional antidepressants are mainly targeted at monoamine neurotransmitters, with ...low remission rates and high recurrence rates. Ketamine is a noncompetitive glutamate
-methyl-
-aspartate receptor (NMDAR) antagonist, and its rapid and powerful antidepressant effects have come to light. Its antidepressant mechanism is still unclarified. Research found that ketamine had not only antagonistic effect on NMDAR but also strong immunomodulatory effect, both of which were closely related to the pathophysiology of MDD. Although there are many related studies, they are relatively heterogeneous. Therefore, this review mainly describes the immune mechanisms involved in MDD and how ketamine plays an antidepressant role by regulating peripheral and central immune system, including peripheral inflammatory cytokines, central microglia, and astrocytes. This review summarizes the related research, finds out the deficiencies of current research, and provides ideas for future research and the development of novel antidepressants.
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