2,595 research outputs found
Prevalence of internet addiction disorder in Chinese university students: A comprehensive meta-analysis of observational studies
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
Near-Infrared (NIR) Luminescent Homoleptic Lanthanide Salen Complexes Ln(4)(Salen)(4) (Ln = Nd, Yb Or Er)
The series of homoleptic tetranuclear [Ln(4)(L)(2)(HL)(2)(NO3)(2)(OH)(2)]center dot 2(NO3) (Ln = Nd, 1; Ln = Yb, 2; Ln = Er, 3; Ln = Gd, 4) have been self-assembled from the reaction of the Salen-type Schiff-base ligand H2L with Ln(NO3)(3)center dot 6H(2)O (Ln = Nd, Yb, Er or Gd), respectively (H2L: N, N'-bis(salicylidene) cyclohexane-1,2-diamine). The result of their photophysical properties shows that the strong and characteristic NIR luminescence for complexes 1 and 2 with emissive lifetimes in microsecond ranges are observed and the sensitization arises from the excited state (both (LC)-L-1 and (LC)-L-3) of the Salen-type Schiff-base ligand with the flexible linker.National Natural Science Foundation 21173165, 20871098Ministry of Education of China NCET-10-0936Higher Education of China 20116101110003State Key Laboratory of Structure Chemistry 20100014Education Committee Foundation of Shaanxi Province 11JK0588Hong Kong Research Grants Council, P. R. of China HKBU 202407, FRG/06-07/II-16)Hong Kong Research Grants Council, Robert A. Welch Foundation F-816Texas Higher Education Coordinating Board ARP 003658-0010-2006Petroleum Research Fund 47014-AC5Chemistr
Tribological Behavior of Si 3
The tribological performance of Si3N4 ball sliding against Ti3SiC2 disc lubricated by lithium-based ionic liquids (ILs) was investigated using an Optimol SRV-IV oscillating reciprocating friction and wear tester at room temperature (RT) and elevated temperature (100°C). Glycerol and the conventional imidazolium-based IL 1-hexyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (L-F106) were used as references under the same experimental conditions. The results show that the lithium-based ILs had higher thermal stabilities than glycerol and lower costs associated with IL preparation than L-F106. The tribotest results show that the lithium-based ILs were effective in reducing the friction and wear of Si3N4/Ti3SiC2 contacts. [Li(urea)]TFSI even produced better tribological properties than glycerol and L-F106 both at RT and 100°C. The SEM/EDS and XPS results reveal that the excellent tribological endurance of Si3N4/Ti3SiC2 contacts lubricated by lithium-based ILs was mainly attributed to the formation of surface protective films composed of various tribochemical products
Y-STR Haplotypic Polymorphisms for the Hakka Population in West China and Its Phylogenic Comparison with Other Chinese Populations
The Hakkas, undergone a series of great migrations, are usually identified with people who speak the Hakka language or share at least same Hakka ancestry. As the largest Hakka dialect island in West China, the Dongshan region was closely linked with the great migration wave of Hakka. However, the paternal genetic profiles of Dongshan Hakka have never been revealed. In the present study, 41 Y-chromosomal short tandem repeat (Y-STR) loci included in the SureID® PathFinder Plus Kit were analyzed in 353 unrelated male individuals (171 Hakka and 182 Han) of Sichuan Province, China. By analyzing 166 different haplotypes among Dongshan Hakkas and 176 different haplotypes among Sichuan Han males, haplotype diversity (HD) of the Hakka population was calculated as 0.9997 with a discrimination capacity (DC) of 0.9708. HD and DC were 0.9996 and 0.9670 for the Sichuan Han population, respectively. Most of the Y-STR loci were highly informative in both populations except DYS645. The genetic relationships were evaluated by comparing the Hakka population with 11 other groups that are relevant to the migration routes of Hakkas. The results of the MDS plot and phylogenetic tree indicate that the Dongshan Hakka population was closely related to Han nationalities from Anhui, Jiangxi, and Fujian Provinces
Effect of genotyping error in model-free linkage analysis using microsatellite or single-nucleotide polymorphism marker maps
Errors while genotyping are inevitable and can reduce the power to detect linkage. However, does genotyping error have the same impact on linkage results for single-nucleotide polymorphism (SNP) and microsatellite (MS) marker maps? To evaluate this question we detected genotyping errors that are consistent with Mendelian inheritance using large changes in multipoint identity-by-descent sharing in neighboring markers. Only a small fraction of Mendelian consistent errors were detectable (e.g., 18% of MS and 2.4% of SNP genotyping errors). More SNP genotyping errors are Mendelian consistent compared to MS genotyping errors, so genotyping error may have a greater impact on linkage results using SNP marker maps. We also evaluated the effect of genotyping error on the power and type I error rate using simulated nuclear families with missing parents under 0, 0.14, and 2.8% genotyping error rates. In the presence of genotyping error, we found that the power to detect a true linkage signal was greater for SNP (75%) than MS (67%) marker maps, although there were also slightly more false-positive signals using SNP marker maps (5 compared with 3 for MS). Finally, we evaluated the usefulness of accounting for genotyping error in the SNP data using a likelihood-based approach, which restores some of the power that is lost when genotyping error is introduced
Sam50 Regulates PINK1-Parkin-Mediated Mitophagy by Controlling PINK1 Stability and Mitochondrial Morphology
PINK1 and Parkin mediate mitophagy, the cellular process that clears dysfunctional mitochondria. Mitophagy is regulated by mitochondrial dynamics, but the molecules linking these two processes remain poorly understood. Here, we show that Sam50, the core component of the sorting and assembly machinery (SAM), is a critical regulator of mitochondrial dynamics and PINK1-Parkin-mediated mitophagy. In response to Sam50 depletion, normal tubular mitochondria are first fragmented and subsequently merged into large spheres. Sam50 interacts with PINK1 to facilitate its processing and degradation. Depletion of Sam50 results in PINK1 accumulation, Parkin recruitment, and mitophagy. Interestingly, Sam50 deficiency induces a piecemeal mode of mitophagy that eliminates mitochondria “bit by bit” but spares mtDNA. In C. elegans, the Sam50 homolog gop-3 is required for the maintenance of mitochondrial morphology and mass. Our findings reveal that Sam50 directly links mitochondrial dynamics and mitophagy and that Sam50 depletion induces elimination of mitochondria without affecting mtDNA content
Successful treatment of Giant keloid on the right toes using trepanation combined with superficial radiotherapy (SRT-100): a case report with literature review
In dermatology, a keloid is one of the most common skin morphological abnormalities caused by excessive proliferation of fibroblasts. Keloids that are large or occur near important joint sites often cause varying degrees of physiological dysfunction in patients, therefore requiring medical treatment. A boy with congenital syndactyly developed huge keloids at the surgical site after undergoing surgical correction treatment. After treatment using trepanation combined with superficial radiotherapy (SRT-100) in our hospital, most of the boy’s keloids shrank and flattened. The affected foot returned to its normal appearance, and the boy could wear shoes normally. The boy did not complain of pain, numbness, or any other distinctive discomfort after completing the treatment. This suggested that the combination of trepanation and SRT-100 may be one of the options for treating hypertrophic keloids that cannot be treated by surgical excision
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Homoprejudiced Violence Experiences and High-Risk Sexual Behaviors among Chinese Men Who Have Sex with Men: Depression Severity and Recreational Drug Usage as Potential Mediators
Homoprejudiced violence is a type of aggression against an individual or a community based on their actual or perceived sexual orientation. It may be linked to risks of acquiring HIV/STI via psychosocial variables. This study explored the association between homoprejudiced violence experiences and high-risk sexual behaviors, and potential psychosocial mediators. Using cross-sectional survey data collected in China through Blued among men who have sex with men (MSM) in January 2021, this study conducted multiple mediation analyses. Standard instruments were used to collect data on depressive symptoms in the last two weeks (PHQ-9), recreational drug usage in the last three months, and ever experiencing homoprejudiced violence (12-item survey instrument). Dependent variables were having condomless anal sex and having three or more sexual partners in the last three months. Among 1828 MSM, nearly half (847, 46%) had experienced homoprejudiced violence. Twenty-three percent (427) reached a score that suggested moderate or severe depression and 35% (644) had used recreational drugs. In the last three months, 40% (731) had condomless anal sex and 34% (626) had three or more sexual partners. The indirect mediational coefficients through depression on condomless anal sex and multiple sexual partners were 0.04 (95% CI: [0.02, 0.07]) and 0.02 (95% CI: [0.001, 0.05]), respectively. The indirect mediational coefficient of homoprejudiced violence experience on multiple sexual partners through recreational drug use was 0.05 (95% CI: [0.03, 0.08]). These findings suggest that more comprehensive interventions are needed to address the syndemic of homoprejudiced violence, mental health issues, and HIV/STI-related risks
Jammed disks in narrow channel: criticality and ordering tendencies
A system of identical disks is confined to a narrow channel, closed off at
one end by a stopper and at the other end by a piston. All surfaces are hard
and frictionless. A uniform gravitational field is directed parallel to the
plane of the disks and perpendicular to the axis of the channel. We employ a
method of configurational statistics that interprets jammed states as
configurations of floating particles with structure. The particles interlink
according to set rules. The two jammed microstates with smallest volume act as
pseudo-vacuum. The placement of particles is subject to a generalized Pauli
principle. Jammed macrostates are generated by random agitations and specified
by two control variables. One is a measure of the intensity of random
agitations at given pressure. The other is a measure of the change in
gravitational potential energy in units of compression work when one particle
is excited. In this two-dimensional space of variables there exists a critical
point. The jammed macrostate realized at the critical point depends on the path
of approach. We describe all jammed macrostates by volume and entropy. Both are
functions of the average population densities of particles. Approaching the
critical point in an extended space of control variables generates two types of
jammed macrostates: states with random heterogeneities in mass density and
states with domains of uniform mass density.Comment: 16 pages, 6 figures, 3 tables, new revised version due to publicatio
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