The relationship between self-esteem and mobile phone addiction among college students: The chain mediating effects of social avoidance and peer relationships

IntroductionMobile phone addiction has a negative impact on the physical and mental health of college students, which has attracted extensive attention from scholars.MethodsIn this study, we investigated the mechanism of the influence of self-esteem on mobile phone addiction among 694 college students using the Self-Esteem Scale, the Mobile Phone. Addiction Scale, the Peer Relationship Scale and the Social Avoidance and Distress Scale.ResultsThe results showed that (1) self-esteem significantly and negatively predicted mobile phone addiction; (2) self-esteem influenced mobile phone addiction through the mediating effect of social avoidance; (3) self-esteem influenced mobile phone addiction through the mediating effect of peer relationships; and (4) social avoidance and peer relationships played a chain mediating role in the influence of self-esteem on mobile phone addiction.DiscussionThese findings can help researchers and educators better understand the underlying mechanisms of the relationship between self-esteem and mobile phone addiction and to provide practical and effective operational suggestions for the prevention and intervention of mobile phone addiction among college students

A single-amino-acid substitution in the HA protein changes the replication and pathogenicity of the 2009 pandemic A (H1N1) influenza viruses in vitro and in vivo

BACKGROUND: The novel pandemic A (H1N1) virus was first identified in Mexico in April 2009 and since then it spread world wide over a short period of time. Although the virus infection is generally associated with mild disease and a relatively low mortality, it is projected that mutations in specific regions of the viral genome, especially within the receptor binding domain of the hemagglutinin (HA) protein could result in more virulent virus stains, leading to a more severe pandemic. RESULTS: Here, we found that a single amino acid substitution of Asp-to-Gly at position 222 in the HA protein of the A (H1N1) virus occurred after two passage propagation in the allantoic cavities of chicken embryonated eggs, and this single residue variation dramatically increased the viral replication ability in MDCK cells and pathogenicity in BALB/c mice. CONCLUSIONS: A substitution of Asp-to-Gly at position 222 in the HA protein was prone to occur under positive selection pressures, and this single amino acid mutation could dramatically increase the virus replication ability in vitro and pathogenicity in vivo. Our finding offers a better understanding of the transmission and evolution of the 2009 pandemic A (H1N1) virus and brings attention to further potentially severe influenza pandemic that may result from cross-host evolution of the influenza viruses

A method for identifying G protein-coupled receptor dimers and their interfaces

The G protein-coupled receptor (GPCR) dimer interface plays an important role in the formation and stabilization of the dimer. Therefore, identifying the potential receptor-receptor interface is an important part of studying GPCRs. Various strategies have been employed to study the GPCR dimer interface and explore its functional significance, but experimental methods lack robustness and calculations are laborious. Herein, we report a combined optimized experimental and calculation approach for identifying and structurally characterizing GPCR dimer interfaces, and constructing atomic resolution models. Using a transmembrane domain (TM) peptide containing a human immunodeficiency virus trans-acting transcriptional activator (HIV-TAT) protein transduction motif, matrix-assisted laser desorption tandem time-of-flight mass spectrometry (MALDITOF-MS), and bioluminescence resonance energy transfer (BRET), we successfully identified Apelin receptor (APJ)/Nociceptin receptor 1 (ORL1) and APJ/Vasopressin receptor 2 (V2R) heterodimer interfaces, and two key sites mediating dimerization. This method can identify dimer interfaces of GPCR homodimers and heterodimers

Helpful to Live Healthier? Intermittent Hypoxic/Ischemic Training Benefits Vascular Homeostasis and Lipid Metabolism with Activating SIRT1 Pathways in Overweight/Obese Individuals

Introduction: The present study aimed to investigate whether and how normobaric intermittent hypoxic training (IHT) or remote ischemic preconditioning (RIPC) plus normoxic training (RNT) has a synergistic protective effect on lipid metabolism and vascular function compared with normoxic training (NT) in overweight or obese adults. Methods: A total of 37 overweight or obese adults (36.03 ± 10.48 years) were randomly assigned to 3 groups: NT group (exercise intervention in normoxia), IHT group (exercise intervention in normobaric hypoxic chamber), and RNT group (exercise intervention in normoxia + RIPC twice daily). All participants carried out the same 1-h exercise intervention for a total of 4 weeks, 5 days per week. Physical fitness parameters were evaluated at pre- and postexercise intervention. Results: After training, all three groups had a significantly decreased body mass index (p < 0.05). The IHT group had reduced body fat percentage, visceral fat mass (p < 0.05), blood pressure (p < 0.01), left ankle-brachial index (ABI), maximal heart rate (HRmax) (p < 0.05), expression of peroxisome proliferator-activated receptor-γ (PPARγ) (p < 0.01) and increased expression of SIRT1 (p < 0.05), VEGF (p < 0.01). The RNT group had lowered waist-to-hip ratio, visceral fat mass, blood pressure (p < 0.05), and HRmax (p < 0.01). Conclusion: IHT could effectively reduce visceral fat mass and improve vascular elasticity in overweight or obese individuals than pure NT with the activation of SIRT1-related pathways. And RNT also produced similar benefits on body composition and vascular function, which were weaker than those of IHT but stronger than NT. Given the convenience and economy of RNT, both intermittent hypoxic and ischemic training have the potential to be successful health promotion strategies for the overweight/obese population

Construction, Expression, and Characterization of a Recombinant Immunotoxin Targeting EpCAM

Epithelial cell adhesion molecule (EpCAM) is a type I transmembrane glycoprotein overexpressed in human epithelioma but with relatively low expression in normal epithelial tissues. To exploit this differential expression pattern for targeted cancer therapy, an EpCAM-targeted immunotoxin was developed and its antitumor activity was investigated in vitro. An immunotoxin (scFv2A9-PE or APE) was constructed by genetically fusing a truncated form (PE38KDEL) of Pseudomonas aeruginosa exotoxin with an anti-EpCAM single-chain variable fragment (scFv). ELISA and flow cytometry were performed to verify immunotoxin (scFv2A9-PE or APE) antigen-binding activity with EpCAM. Cytotoxicity was measured by MTT assay. Confocal microscopy was used to observe its cellular localization. The results of ELISA and flow cytometry revealed that the immunotoxin efficiently recognized recombinant and natural EpCAM. Its antigen-binding activity was relatively lower than 2A9. MTT assay confirmed potent reduction in EpCAM-positive HHCC (human hepatocellular carcinoma) cell viability (IC50 50 pM). Immunofluorescence revealed that the immunotoxin localized to endoplasmic reticulum 24 h later. In conclusion, we described the development of an EpCAM-targeted immunotoxin with potent activity against tumor cells, which may lay the foundation for future development of therapeutic antibody for the treatment of EpCAM-positive tumors

Biochar induces mineralization of soil recalcitrant components by activation of biochar responsive bacteria groups

Amendment of soil with biochar induces a shift in microbial community structure and promotes faster mineralization of soil organic carbon (SOC), thus offsetting C sequestration effects. Whether biochar induces losses of labile or persistent SOC pools remains largely unknown, and the responsible decomposers await identification. Towards addressing these ends, a C3 soil was amended with Biochar500 or Biochar600 (pyrolyzed at 500 ◦C and 600 ◦C, respectively) produced from a C4-maize feedstock and incubated for 28 days. Combination of stable isotope 13C techniques, high-throughput sequencing and Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR MS) allowed changes in soil chemodiversity and biodiversity, as well as their interactive effects on biochar induced SOC mineralization to be elucidated. Results indicated that: i) biochar addition shifted the bacterial community towards dominance of Gemmatimonadetes, Bacteroidia, Alphaproteobacteria and Gammaproteobacteria classes, and coincidence with recalcitrant C components and neutral pH soil; ii) the persistent DOM components (such as condensed aromatics and tannin) were depleted in biochar amended soils, while labile DOM components (such as unsaturated hydrocarbons, lipids, carbohydrates and proteins/amino sugar) were relatively enriched, and; iii) Biochar600 promoted additional soil derived CO2 carbon loss over 28 days (93 mg C kg− 1 soil). Collectively, these results suggested that the majority of soil derived CO2 efflux in biochar amended soils originated from recalcitrant components that were mineralized by the persistent organic matter decomposers. This research highlights the significance of biochar responsive taxa in changes of DOM chemodiversity and potential loss of SOC via mineralization