Health is an important topic for everyone and essential to high-quality economic and social development. Recently, some researchers have suggested that older adults' internet use may have a health ...effect.
This study specifically aims to clarify the relationship between internet use and the mental health of older adults, for which other surveys present contradictory results.
Data were obtained from the China Longitudinal Aging Social Survey conducted in 2018. A total of 6648 participants were included. Mental health was assessed by the 12-item Center for Epidemiological Studies Depression Scale. Ordinary least squares regression was adopted to explore the relationship between internet use (independent variable) and the mental health of older adults. Robustness analysis, sensitivity analysis, and heterogeneity analysis were conducted in detail to verify the empirical result. A mediating effect analysis was further conducted to discover the effect mechanism between the dependent and independent variables.
It was found that internet use and smartphone use can significantly improve the mental health of older adults (ordinary least squares, β=.075; P<.001). After endogenous and robustness tests were conducted, the aforementioned conclusion remained robust. In particular, participation in voluntary activities played a mediating role in the relationship between internet use and the mental health of older adults. In addition, younger subjective age enhanced the positive effect of internet use on the mental health of older adults.
Internet users showed higher levels of mental health among Chinese older adults. To improve the mental health of older adults, the government should not only cultivate the ability to use the internet but also encourage greater participation in voluntary activities among older adults.
This research focused on pre-service mathematics teachers’ sharing of knowledge through reciprocal peer feedback. In this study, pre-service teachers were divided into groups of five and engaged in ...an online reciprocal peer feedback activity. Specifically, after creating an individual concept map indicating high school students’ possible solutions to an algebra problem, pre-service teachers shared their individual maps with team members and engaged in online discussion, commenting on the concept maps of other group members and responding to peers’ feedback. Similarities in team members’ knowledge representations before and after this peer feedback activity were compared in order to analyze their knowledge convergence. It was found that a team member’s knowledge was more likely to match that of other team members after the online reciprocal peer feedback activity. Qualitative analysis was also conducted in order to explore the possible influence of a team’s interaction process on members’ knowledge convergence. It was also found that, after engaging in this peer feedback process, pre-service teachers demonstrated greater improvement in their convergence of concepts relating to problem-solving strategies than in the concepts representing problem context and domains.
This paper extends the investigation of deeper learning beyond learning as an individual endeavor by looking at the collaborative achievement of teams. Healthcare students were engaged in ...collaborative concept mapping to solve an authentic, contextually situated problem in triads. Both quantitative and qualitative investigations have been conducted to study specifically the impact of learners' conflict resolution on their deeper learning as measured by knowledge convergence (KC). Knowledge convergence refers the similarity between team members' post-collaboration knowledge representations derived through interaction. To compute learners' KC, team members' post-collaboration individual maps were compared through Pathfinder analysis. Contrary to prior research findings, increased conflict negotiation behaviors by an individual resulted in fewer similarities between his or her second map and other members' maps. Theme analysis revealed both effective interaction strategies and challenges that impacted triad team members' attainment of KC. Findings from this study can inform development of effective instructional support to cultivate the occurrence of deeper learning within the contexts of collaborative concept mapping and healthcare education.
•Healthcare students engaged in collaborative concept mapping to solve a problem.•Occurrence of deeper learning was measured by knowledge convergence (KC).•Learners' engagement in conflict negotiation hindered the achievement of KC.•Interaction strategies during conflict resolution that impacted KC were identified.
Various two-dimensional (2D) side-chain-substituted benzo(1,2-b:4,5-b′)dithiophene (BDT) blocks have been used to construct donor polymers, whereas the size effect of the side chains on the ...photovoltaic performance was overlooked in the past few years. In this work, three size-varied conjugated spaces (benzene, naphthalene, and biphenyl) were introduced into the corresponding polymers PBDB-Ph, PBDB-Na, and PBDB-BPh. This space engineering has a significant impact on the extent of phase separation in the active layer which blended with the polymer and the acceptor ITCPTC and preserved the desired morphology. The varied space size in the side chains lead to distinct balance mobility ratios of holes to electrons (benzene, 0.21; naphthalene, 0.75; and biphenyl, 0.57). Finally, PBDB-Na-based polymer solar cells (PSCs) delivered the highest power conversion efficiency of 12.52% when compared to the PSC performances of PBDB-Ph (8.48%) and PBDB-BPh (11.35%). The method in tailoring the side chain structures could fabricate a balance between phase separation and charge transport, providing an enlightenment for the development of photovoltaic devices.
To obtain a polymer based on benzodithiophene (BDT) owning both a largely extended π-conjugation system and a low-lying highest occupied molecular orbital (HOMO), a polymer (PBDTBzT-DTffBT) ...containing benzothienyl-substituted BDT is designed and synthesized. Compared with the polymer (PBDTT-DTffBT) based on thienyl-substituted BDT, PBDTBzT-DTffBT exhibits better thermal stabilities, red-shifted absorption spectra, and stronger intermolecular interactions. The HOMO and lowest unoccupied molecular orbital (LUMO) in PBDTBzT-DTffBT are decreased by 0.11 and 0.13 eV, respectively, which should be attributed to the contribution of the electron-withdrawing group benzene. Polymer solar cells (PSCs) based on PBDTBzT-DTffBT and 6,6-phenyl-C61-butyric acid methyl ester (PC61BM) exhibit a maximum power conversion efficiency (PCE) of 7.30% with a large open-circuit voltage of 0.90 V under AM 1.5G illumination (100 mW/cm2). The PCE is 36% higher than that of the PSCs derived from PBDTT-DTffBT. These findings provide a new approach to design high-performance conjugated polymers for efficient solution-processed PSCs.
The aggregation structure of dye molecules has a great influence on the properties of dye solutions, especially in high concentration. Here, the dye molecular aggregation structures were investigated ...systemically in aqueous solutions with high concentration using three reactive dyes (O-13, R-24:1 and R-218). O-13 showed stronger aggregation than R-24:1 and R-218. This is because of the small non-conjugate side chain and its β-linked position on the naphthalene of O-13. Compared with R-218, R-24:1 showed relatively weaker aggregation due to the good solution of R-24:1. The change of different aggregate distributions in the solutions were also investigated by splitting the absorption curves. Moreover, it is found that the surface tension of solutions can be modified by the combined effect of both aggregation and the position of the hydrophilic group, which, however, also have an effect on viscosity. This exploration will provide guidance for the study of high concentration solutions.
A new zirconium-based metal-organic polyhedron was successfully synthesized and it possesses considerable reversible iodine sorption performance.
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•A tetrahedral Zr-MOP-1 was ...successfully synthesized under solvothermal condition.•Zr-MOP-1 possesses considerable reversible iodine sorption performance.•The adsorbed I− and I3− in Zr-MOP-1 were identified by crystallographic analyses.
A new zirconium-based metal-organic polyhedron (Zr-MOP-1) was successfully synthesized from Bis(cyclopentadienyl)zirconium dichloride and 2,5-pyridinedicarboxylic acid under solvothermal condition. It was characterized by single-crystal X-ray diffraction, powder X-ray diffraction, thermogravimetric analysis and infrared spectroscopy. Four trinuclear zirconocene building blocks as well as six linear carboxylate ligands give rise to its tetrahedral configuration. Interestingly, Zr-MOP-1 possesses considerable reversible iodine sorption performance in organic phase featuring an optimal adsorption capacity of 283 mg g−1. The related kinetics absorption and desorption process were fully explored in detail by multiple complementary experiments and the adsorbed iodine species (I− and I3−) in Zr-MOP-1 had been further identified through crystallographic analyses. This work provides new possibilities for developing new and functional zirconium-based molecular cages materials.
In textile inkjet printing, the surface tension and viscosity of the reactive dye solution are two important physical properties to control the droplet formation. In this work, surface tensions and ...viscosities of four reactive dye solutions with/without surfactants and organic solvents were tested to investigate the effect of reactive dye structures on them. The results show that on dye molecules the hydrophobic groups not linking to hydrophilic groups or large in size can lead to a decrease in the surface tension and an increase in the viscosity. Moreover, droplet formations of these solutions are observed. It is found that reactive dye structures can also affect the droplet formation through influencing the surface tension and viscosity of dye solutions. This study is significant for adjusting the surface tension and viscosity of the reactive dye solution according to dye structures.
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•Effects of reactive dye structures on the surface tension and viscosity is studied.•Hydrophobic structures affect the surface tension and viscosity of dye solution.•Reactive dye structures also have influence on droplet formation.
Hypoxanthine phosphoribosyl transferase 1 (HPRT1) is traditionally believed to be a housekeeping gene. However, recent reports have indicated that HPRT1 overexpression is associated with a poor ...prognosis in various types of cancers. Using The Cancer Genome Atlas (TCGA), HPRT1 was found to be highly expressed in various cancer types, especially in head and neck squamous cell carcinoma (HNSCC). Therefore, we measured HPRT1 expression in human cancer tissues and adjacent non-carcinoma tissues (ANT) and explored the relationship between HPRT1 expression and clinical pathological factors and prognosis in patients with oral squamous cell carcinoma (OSCC), a common type of HNSCC. We built OSCC cells with stable knockdown and overexpression of HPRT1 to observe its influence on chemoresistance and malignancy in vitro and vivo. We found that highly expressed HPRT1 was associated with a poor prognosis and could promote resistance to cisplatin (CDDP) in OSCC cells in both in vitro and in vivo. An RNA sequence assay was carried out to explore the mechanism of function of HPRT1, we found that HPRT1 could positively regulate the expression of MMP1 and the activation of the PI3K/AKT pathway, to regulate the resistance to CDDP of OSCC. In conclusion, HPRT1 can no longer be simply believed to be a housekeeping gene. HPRT1 overexpression indicates a worse prognosis and can improve CDDP resistance for patients with OSCC by promoting the MMP1/PI3K/Akt axis. HPRT1 may be a potential prognostic biomarker and therapeutic target in OSCC.
The layer-by-layer process method, which had been used to fabricate a bilayer or bulk heterojunction organic solar cell, was developed to fabricate highly efficient ternary blend solar cells in which ...small molecules and polymers act as two donors. The active layer could be formed by incorporating the small molecules into the polymer based active layer via a layer-by-layer method: the small molecules were first coated on the surface of poly(3,4-ethylenedioxy-thiophene):poly(styrenesulfonate) (PEDOT:PSS), and then the mixed solution of polymer and fullerene derivative was spin-coated on top of a small molecule layer. In this method, the small molecules in crystalline state were effectively mixed in the active layer. Without further optimization of the morphology of the ternary blend, a high power conversion efficiency (PCE) of 8.76% was obtained with large short-circuit current density (J sc) (17.24 mA cm–2) and fill factor (FF) (0.696). The high PCE resulted from not only enhanced light harvesting but also more balanced charge transport by incorporating small molecules.
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