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Abstract

Background and aims

Compulsivity contributes to the development and maintenance of multiple addictive disorders. However, the relationship between compulsivity-related cognitive features and problematic usage of the internet (PUI), an umbrella term for various internet use disorders/interfering behaviors, remains largely unclear, partly due to the multidimensional nature of compulsivity. This scoping review utilized a four-domain framework of compulsivity to consider this topic and aimed to summarize available evidence on compulsivity-related neuropsychological characteristics in PUI based on this framework.

Methods

A systematic literature search was conducted by applying the combination of search term to the search engines of PubMed, PsycINFO and Web of Science. A four-domain framework of compulsivity, involving cognitive flexibility, set-shifting, attentional bias, and habit learning, was used to consider its complex structure and frequently used tasks. Main findings in related PUI studies were summarized based on this framework. Our secondary aim was to compare compulsivity-related features between different PUI subtypes.

Results

Thirty-four empirical studies were retained, comprising 41 task-results and 35 independent data sets. Overall, individuals with PUI showed more consistent deficits in attentional biases and were relatively intact in set-shifting. Few studies have examined cognitive flexibility and habit learning, and more evidence is thus needed to establish reliable conclusions. Moreover, most studies focused on internet gaming disorder, whereas other PUI sub-types were not sufficiently examined.

Conclusion

This systematic review highlights the use of the four-domain framework for advancing understanding of mechanisms underlying compulsivity in PUI. Related therapeutic implications and future directions are discussed.

Open access
Journal of Behavioral Addictions
Authors:
Haoran Meng
,
Hongjian Cao
,
Ruining Hao
,
Nan Zhou
,
Yue Liang
,
Lulu Wu
,
Lianjiang Jiang
,
Rongzi Ma
,
Beilei Li
,
Linyuan Deng
,
Zhong Lin
,
Xiuyun Lin
, and
Jintao Zhang

Abstract

Background and aims

Previous studies on smartphone use motivation (SUM) and problematic smartphone use (PSU) have been limited in the utilization of regional samples of emerging adults (e.g., college students) and also in the foci on the direct association between SUM and PSU. To address such gaps, using data from a large, national representative sample of Chinese young adolescents and their parents this study examined the associations between adolescents' various types of SUM and their PSU, and also tested the potential mediating roles of smartphone use time (SUT) that adolescents spent on various activities in such associations.

Methods

A nationwide representative sample of 8,261 Chinese adolescents (M age = 12.86 years old, SD = 1.76; 42.6% females) and their parents (49% mothers) participated in this survey study.

Results

Instrumental SUM (i.e., to expand knowledge or acquire information) was associated negatively with PSU via longer SUT spent on learning and shorter SUT spent on entertainment and communication. Self-expression SUM (i.e., to gain acceptance and recognition of others by maintaining or improving self-images) was associated with longer SUT spent on both learning and entertainment, which, in turn, predicted lower and higher levels of PSU, respectively. Last, hedonic SUM (i.e., to gain pleasure) was associated positively with PSU via longer SUT spent on entertainment and communication.

Discussion

These findings contribute to the literature by adding greater specificity in our understanding of the implications of SUM and SUT in the etiology of PSU during the critical life stage of adolescence in a Chinese cultural context.

Open access

Abstract  

Effects of fullerenes including FS, EFS and pure C60 on thermal behaviors of polyethylene glycol (PEG) have been studied by employing thermogravimetry-differential thermogravimetry (TG-DTG), differential scanning calorimeter (DSC) and off-line furnace-type pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS). The products were collected by Cambridge filter pad which was widely used in analyzing the combustion products of cigarette. The results showed that the addition of fullerenes obviously restrained the thermal decomposition of PEG. The initial decomposition temperatures (IDT) and maximum decomposition peak temperatures (MDT) were evidently postponed by the addition of fullerenes. Pyrolysis products with one or two hydroxyl end groups obviously increased with the addition of 10% C60. The reasons of the changes were discussed from the aspects of reaction mechanisms.

Restricted access

Eupatilin, mainly derived from Artemisia asiatica (Asteraceae), is an O-methylated flavone with various bioactivities. In the present study, a validated ultra-performance liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) method was established for the quantification of eupatilin in rat plasma with the internal standard (IS) of tussilagone and the protein precipitation of plasma samples was performed using acetonitrile–methanol (9:1, v/v). The eupatilin and IS were eluted separately on a UPLC BEH C18 column (2.1 mm × 100 mm, 1.7 μm) with the gradient mobile phase consisted of 0.1% formic acid and acetonitrile. The protonated analytes were quantified by multiple reactions monitoring (MRM) mode with an electrospray ionization (ESI) source operated in positive ion mode. The calibration plots were found to be linear over the range from 2 to 1000 ng/mL for eupatilin in rat plasma. Both of the intra-day and inter-day precision variations (RSDs) were ≤13%. The recoveries of eupatilin in rat plasma were between 83.7% and 94.6%, and the accuracy of the method ranged from 95.8% to 107.6%. In addition, the validated method was applied to pharmacokinetic study of eupatilin after an intravenous dose of 2 mg/kg to rats.

Open access

Abstract

Background and aims

The COVID-19 pandemic poses a grim challenge to adolescents’ daily life, including schooling and learning, which has great impacts on their mental and behavioral health. This study aimed to test the roles of stress related to schooling and online learning during COVID-19 (COVID-19 stress) in depression and Internet gaming disorder (IGD) among adolescents and the potential mediators of social support, academic stress, and maladaptive emotion regulation based on the framework of Conservation of Resources theory. Sex differences in these associations were further examined.

Methods

A school-based survey was conducted among Chinese adolescents in 13 secondary schools in Hong Kong (n = 3,136) from September to November 2020 (48.1% males; mean age = 13.6 years old) using stratified random sampling.

Results

The prevalence of probable depression and IGD was 60% and 15%, respectively. Results of structural equation modeling indicated that the proposed model fit the data well (χ2/df = 7.77, CFI = 0.92, IFI = 0.92, RMSEA = 0.05). COVID-19 stress was positively and indirectly associated with both depression and IGD through social support, academic stress, and maladaptive emotion regulation. Multi-group analyses identified that the associations between COVID-19 stress and academic stress, between academic stress and depression, and between social support and depression were stronger among females compared to males.

Discussion and conclusions

Findings highlight the roles of academic stress, poor social support, maladaptive emotion regulation, and sex to understand how disruption and stress caused by COVID-19 increases adolescent depression and IGD. Psychosocial interventions based on these factors are highly warranted.

Open access

Abstract

Background and aims

The study aims to thoroughly understand the causal and precedent modifiable risk or protective factors for Internet Gaming Disorder (IGD), a newly defined and prevalent mental disorder.

Methods

We performed a systematic review on quality-designed longitudinal studies based on five online databases: MEDLINE, PsycINFO, Embase, PubMed, and Web of Science. Studies were included in the meta-analysis if they addressed IGD, adopted longitudinal, prospective, or cohort study designs, presented modifiable factors of IGD, and reported the effect sizes for correlations. Pooled Pearson's correlations were calculated using the random effects model.

Results

Thirty-nine studies with 37,042 subjects were included. We identified 34 modifiable factors, including 23 intrapersonal factors (e.g., gaming time, loneliness, etc.), 10 interpersonal factors (e.g., peer relationship, social support, etc.), and 1 environmental factor (i.e., school engagement). Age, the male ratio, study region, and study years were significant moderators.

Discussion and conclusions

Intrapersonal factors were stronger predictors than interpersonal and environmental factors. It may imply that individual-based theories are more powerful to explain the development of IGD. Longitudinal research on the environmental factors of IGD was lacking; more studies are warranted. The identified modifiable factors would help to guide effective interventions for IGD reduction and prevention.

Open access
Journal of Thermal Analysis and Calorimetry
Authors:
Lin-Quan Liao
,
Hong-Jian Wei
,
Ji-Zhen Li
,
Xue-Zhong Fan
,
Ya Zheng
,
Yue-Ping Ji
,
Xiao-Long Fu
,
Ya-Jun Zhang
, and
Fang-Li Liu

Abstract

The compatibility of poly(3-nitromethyl-3-methyloxetane) (PNIMMO) with some energetic materials are studied by using pressure DSC method in detail. Cyclotetramethylenetetranitroamine (HMX), cyclotrimethylenetrinitramine (RDX), nitrocellulose (NC), nitroglycerine (NG), N-nitrodihydroxyethylaminedinitrate (DINA), and aluminum powder (Al) are used as common energetic materials, and 3,4-dinitrofurzanfuroxan (DNTF), 1,3,3-trinitroazetidine (TNAZ), hexanitrohexazaisowurtzitane (CL-20), 4,6-dinitro-5,7-diaminobenzenfuroxan (CL-14), 1,1-diamino-2,2-dinitroethylene (DADNE), and 4-amino-5-nitro-1,2,3-triazole (ANTZ) are used as new energetic materials. The results show that the binary systems of PNIMMO with HMX, RDX, NC, NG, DINA, Al, CL-14 and DADNE are compatible, with TNAZ, CL-20 and ANTZ are slightly sensitive, and with DNTF is sensitive.

Open access
Journal of Behavioral Addictions
Authors:
Lu Li
,
Dan-Dan Xu
,
Jing-Xin Chai
,
Di Wang
,
Lin Li
,
Ling Zhang
,
Li Lu
,
Chee H. Ng
,
Gabor S. Ungvari
,
Song-Li Mei
, and
Yu-Tao Xiang

Background and aims

Internet addiction disorder (IAD) is common in university students. A number of studies have examined the prevalence of IAD in Chinese university students, but the results have been inconsistent. This is a meta-analysis of the prevalence of IAD and its associated factors in Chinese university students.

Methods

Both English (PubMed, PsycINFO, and Embase) and Chinese (Wan Fang Database and Chinese National Knowledge Infrastructure) databases were systematically and independently searched from their inception until January 16, 2017.

Results

Altogether 70 studies covering 122,454 university students were included in the meta-analysis. Using the random-effects model, the pooled overall prevalence of IAD was 11.3% (95% CI: 10.1%–12.5%). When using the 8-item Young Diagnostic Questionnaire, the 10-item modified Young Diagnostic Questionnaire, the 20-item Internet Addiction Test, and the 26-item Chen Internet Addiction Scale, the pooled prevalence of IAD was 8.4% (95% CI: 6.7%–10.4%), 9.3% (95% CI: 7.6%–11.4%), 11.2% (95% CI: 8.8%–14.3%), and 14.0% (95% CI: 10.6%–18.4%), respectively. Subgroup analyses revealed that the pooled prevalence of IAD was significantly associated with the measurement instrument (Q = 9.41, p = .024). Male gender, higher grade, and urban abode were also significantly associated with IAD. The prevalence of IAD was also higher in eastern and central of China than in its northern and western regions (10.7% vs. 8.1%, Q = 4.90, p = .027).

Conclusions

IAD is common among Chinese university students. Appropriate strategies for the prevention and treatment of IAD in this population need greater attention.

Open access
Cereal Research Communications
Authors:
H. Yu
,
Y. Yang
,
X.Y. Chen
,
G.X. Lin
,
J.Y. Sheng
,
J.Y. Nie
,
Q.J. Wang
,
E.J. Zhang
,
X.R. Yu
,
Z. Wang
, and
F. Xiong

The waxy wheat shows special starch quality due to high amylopectin content. However, little information is available concerning the development and degradation of amyloplast from waxy wheat endosperm. To address this problem, waxy wheat variety, Yangnuo 1, and a non-waxy wheat variety, Yangmai 13, were chosen to investigate the development and degradation of endosperm amyloplast during wheat caryopsis development and germination stage respectively using histochemical staining and light microscopy. Changes of morphology, the soluble sugar and total starch content were indistinguishable in the process of caryopsis development of two wheat varieties. The developing endosperm of non-waxy was stained blue-black by I2-KI while the endosperm of waxy wheat was stained reddish-brown, but the pericarp of waxy and non-waxy wheat was stained blue-black. In contrast to nonwaxy wheat, endosperm amyloplast of waxy wheat had better development status and higher proportion of small amyloplast. During seed germination many small dissolution pores appeared on the surface of endosperm amyloplast and the pores became bigger and deeper until amyloplast disintegrated. The rate of degradation of waxy wheat endosperm amyloplast was faster than non-waxy wheat. Our results may also be helpful to the use of waxy starch in food and nonfood industry.

Restricted access

Abstract

It still remains a great challenge to selectively enrich and sensitively quantify the trace volatile organic compounds (VOCs) in real samples with complex matrix. In this study, an integration method combining a selective enrichment medium of reduced graphene oxide (rGO) with a specially designed micro thermal-assisted purge-and-trap sampling device was developed for efficient enrichment and sensitive quantification of trace tobacco VOCs coupling with thermal desorption (TD)-gas chromatography/mass spectrometry (GC/MS). The prepared rGO has been proved to possess excellent enrichment selectivity and capacity for tobacco polar VOCs with the multi-layer structure, good thermal stability and large specific surface area. The specially designed sampling device was efficient and suitable for enriching and sampling trace polar tobacco VOCs coupling with rGO medium. Under the optimized sampling and analytical conditions, the established analytical method could be actually applied for quantification of typical tobacco polar VOCs with the good recoveries of 72.9–128% and the satisfied RSDs of 1.8–19.9% (n = 3). The results suggested that the developed method was selective, sensitive and reliable for enrichment and quantification of trace tobacco polar VOCs.

Open access