168 research outputs found

    The Predictive Role of Materialistic Values on Learning Burnout by Pre-service Teachers: A Parallel Channel Model

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    This study set out to explore the relationship between materialistic values (MVS), ontological security threat (OST), gratitude, and learning burnout (LB) among pre-service teachers enrolled in the Free Teacher Education program in China. MVS, adolescent student burnout, gratitude, and OST questionnaires were administered to 801 pre-service teachers. Data processing was conducted using IBM SPSS 26.0 and AMOS 24.0. The SPSS macro program Model 4 was used to identify mediating mechanisms. Study findings were as follows: (1) MVS was positively correlated with both OST and LB, but negatively correlated with gratitude. (2) OST was positively correlated with LB, while gratitude was negatively correlated with LB. (3) The impact of MVS on pre-service teachers' LB was simultaneously mediated by OST and gratitude. MVS not only directly predicts pre-service teachers' LB, but also influences LB through the independent mediators of OST and gratitude

    The influence of gratitude on pre-service teachersā€™ career goal self-efficacy: Chained intermediary analysis of meaning in life and career calling

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    ObjectiveThe aim of the study was to explore the relationship among gratitude, meaning in life (MIL), career calling, and career goal self-efficacy (CGSE) of the pre-service teachers in the Free Teacher Education program in China and the internal mechanism of action.MethodsIn this study, gratitude, MIL, career calling, and CGSE questionnaires were used to investigate 801 pre-service teachers. IBM SPSS 25.0 and AMOS 24.0 were used for data processing, and SPSS macro program Model 6 was used for the mediating mechanism.Results(1) Gratitude was positively correlated with MIL and career calling. MIL was positively correlated with career calling. Gratitude, MIL, and career calling were significantly and positively associated with CGSE. (2) Gratitude influences pre-service teachersā€™ CGSE mainly through the independent intermediary of MIL and career calling, and the chain intermediary of MILā†’career calling, three indirect effects.ConclusionGratitude indirectly predicts CGSE of pre-service teachers not only through the independent intermediary of MIL and career calling but also through the chain intermediary of MIL and career calling

    Reconstruction of dissolved oxygen in the Indian Ocean from 1980 to 2019 based on machine learning techniques

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    Oceanic dissolved oxygen (DO) decline in the Indian Ocean has profound implications for Earthā€™s climate and human habitation in Eurasia and Africa. Owing to sparse observations, there is little research on DO variations, regional comparisons, and its relationship with marine environmental changes in the entire Indian Ocean. In this study, we applied different machine learning algorithms to fit regression models between measured DO, ocean reanalysis physical variables, and spatiotemporal variables. We utilized the Extremely Randomized Trees (ERT) model with the best performance, inputting complete reanalysis data and spatiotemporal information to reconstruct a four-dimensional DO dataset of the Indian Ocean during 1980ā€“2019. The evaluation results showed that the ERT-based DO dataset was superior to the DO simulations in Earth System Models across different time and space. Furthermore, we assessed the spatiotemporal variations in reconstructed DO dataset. DO decline and oxygen-minimum zone (OMZ) expansion were prominent in the Arabian Sea, Bay of Bengal, and Equatorial Indian Ocean. Through correlation analysis, we found that temperature and salinity changes related to solubility primarily control the oxygen decrease in the middle and deep sea. However, the complicated factors with solubility change, vertical mixing, and circulation govern the oxygen increase in the upper and middle sea. Finally, we conducted a volume integral to estimate the oxygen content in the Indian Ocean. Overall, a deoxygenation trend of āˆ’141.5 Ā± 15.1 Tmol decāˆ’1 was estimated over four decades, with a slowdown trend of āˆ’68.9 Ā± 31.3 Tmol decāˆ’1 after 2000. Under global warming and climate change, OMZ expanding and deoxygenation in the Indian Ocean are gradually mitigating. This study enhances our understanding of DO dynamics of the Indian Ocean in response to deoxygenation

    BlyS is up-regulated by hypoxia and promotes migration of human breast cancer cells

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    <p>Abstract</p> <p>Background</p> <p>The role of B Lymphocyte Stimulator (BLyS) in the survival of malignant B cells and the maintenance of normal B cell development and homeostasis has been intensively studied in the literature. However, the influence of BLyS on breast cancer progression remains unclear. The study aimed to investigate the effect of hypoxia on BLyS regulation, cell migratory response to BLyS and the possible molecular mechanisms.</p> <p>Methods</p> <p>In this study, we examined the role of BLyS in the migration of human breast cancer cells by transwell assay. We also explored whether BLyS and its receptors expressed in human breast cancer cell lines by immunofluorescence and Western Blotting. Then we detected the expression level of BLyS in both normoxic and hypoxic conditions by real time-PCR and Western Blotting. Pathways involved were confirmed by Western Blotting, immunofluorescence, transwell assay and luciferase assay.</p> <p>Results</p> <p>According to our study, the expression level of BlyS was increased in human breast cancer cell lines in hypoxic conditions. Up-regulation of this protein led to activation and nuclear translocation of NF-kappa B p65. We also found that the number of migrated cells was increased in the presence of BLyS and inhibition of phosphorylation of Akt attenuated the enhanced migratory response.</p> <p>Conclusions</p> <p>It suggested that better understanding of BLyS, an immunopotentiator, may offer a potential therapeutic target for the treatment of human breast cancers. In addition, BLyS promoted breast cancer cells migration, underscoring the necessity of appropriate applications of immunopotentiators to cancer treatment.</p

    Enhancing flame retardancy, anti-impact, and corrosive resistance of TPU nanocomposites using surface decoration of Ī±-ZrP

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    The development of polyurethane composites with significant flame retardancy and corrosion resistance for widening its practical application is a great importance. In this study, supramolecular wrapped Ī±ā€ZrP (MCP@ZrP) was prepared via selfā€assembly of melamine, cobalt ions (Co Ā²āŗ ) and phytic acid (PA) on the surfaces of Ī±ā€zirconium phosphate (Ī±ā€ZrP). It was found that both compatibility and dispersion of Ī±ā€ZrP sheets in thermoplastic polyurethane (TPU) matrices were improved with the incorporation of organic supramolecular components in TPU/MCP@ZrP nanocomposites. Moreover, their fireā€retardant characteristic was significantly enhanced, along with effective suppression of smoke and toxic gas emission. By adding 5 wt% MCP@ZrP, peak heat release rate, total heat release, total smoke production, and total CO production of such nanocomposites were reduced by 35.66%, 18.01%, 15.52%, and 41.42%, respectively. The generation of a continuous and dense char layer benefited from wellā€dispersed MCP@ZrP nanohybrids, which resulted in tortuous effect to impede heat diffusion and prevent the evaporation of volatile gasses. By means of the barrier effect of ZrP, TPU/MCP@ZrP composite films also showed improved anticorrosion performance. Effective interfacial adhesion, achieved by combining MCP supermolecules and Ī±ā€ZrP sheets, offers a viable approach to improve protective properties of TPU nanocomposites. Highlights Supramolecularā€wrapped Ī±ā€ZrP was prepared via selfā€assembly strategy. MCP@ZrP showed good dispersion and interface adhesion within TPU matrices. MCP@ZrP enhanced the flame retardancy and mechanical performance of TPU. MCP@ZrP preventing smoke and toxic gas evaporation

    Early tissue and healing responses after maxillary sinus augmentation using horizontal platelet rich fibrin bone blocks.

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    BACKGROUND The effects of horizontal platelet-rich fibrin (H-PRF) bone block on the healing and immune response during sinus augmentation have not been fully investigated histologically at early time points. METHODS Eighteenth male New Zealand white rabbits underwent bilateral sinus augmentation and were divided into two groups: deproteinized bovine bone mineral (DBBM) alone and H-PRFā€‰+ā€‰DBBM (H-PRF bone block) group. Maxilla samples were collected at 3, 7 and 14 days post sinus augmentation procedures and analyzed using histological staining for the number of inflammatory cells, new blood vessels and evidence for early osteoclast bone turnover/remodeling. Furthermore, the effects of H-PRF bone blocks on the migration of osteoblasts and THP-1 macrophages were evaluated using a Transwell assay in vitro. RESULTS A higher number of immune cells were found in the H-PRF bone block group at 3 and 7 days post-surgery when compared to the DBBM alone group,most notably in the regions close to the mucosal lining and bone plates. Furthermore, a significantly greater number of new blood vessel formations and early signs of osteoclast development were found in the H-PRF bone block group at 14 days. The in vitro transwell assay further confirmed that culture medium from H-PRF bone block markedly promote the migration of osteoblasts and THP-1 macrophages. CONCLUSIONS The findings from this study have shown that H-PRF bone block is capable of increasing early immune cell infiltration leading to the acceleration of neovascularization and speeding the process of bone metabolism in vivo following maxillary sinus grafting with DBBM

    Original Article Phase II clinical trial of palonosetron combined with tropisetron in preventing chemotherapy-induced nausea and vomiting

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    Abstract: The purpose of the study was to evaluate the efficacy and toxicity of palonosetron combined with tropisetron in preventing chemotherapy-induced nausea and vomiting. A total of 82 non-small cell lung cancer patients undergoing Docetaxel combined with Cisplatin were randomly divided into group A and group B. The patients were received palonosetron combined with tropisetron (group A, n = 42) or tropisetron alone (group B, n = 40) before initiation of chemotherapy. The nausea degree, antiemetic efficacy and safety after chemotherapy were evaluated. Patients were administered for rescue therapy if needed. Results showed no significant difference in complete remission rate (CRR) during acute phase (0-24 h post chemotherapy) between group A and group B (90.48% versus 75%, P &gt; 0.05). The CRR of group A during delayed (24-120 h post chemotherapy) and overall phases (0-120 h post chemotherapy) were 83.33% and 78.57%, higher than group B (50% and 42.50%, P &lt; 0.05). AS for the improvement rate of nausea during delayed phase, group A is better than group B (57.14% versus 35%, P &lt; 0.05). The adverse drug reactions of two groups were mild and generally well tolerated, including headache, constipation and abdominal distension, and no statistically significant differences were observed. In conclusions, compared to tropisetron alone, the therapy of palonosetron plus tropisetron is more effective and safer in controlling of nausea and vomiting induced by high emetic risk chemotherapy

    A method to achieve spectral beam combining based on a novel symmetric grating

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    A symmetric grating is proposed to obtain higher output power in spectral beam combination by increasing the number of lasers and spectral utilization. The grating allows laser beams to be incident from both sides of the grating normal to achieve coaxial beam combining, so the number of beams and the combined output power are doubled compared with the traditional grating under the same spectral line-width. The grating is designed with the central wavelength of 4.65Ā Ī¼m, and the calculation results show that this grating is very advantageous for spectral beam combining, especially for the light waves in the range 4.55ā€“4.71Ā Ī¼m, where their diffraction efficiencies are high (over 80%) and correspond to a wide and linear range of incidence angles. Meanwhile, based on the symmetric gratings we further propose a circular grating to achieve the same frequency spectral beam combining. This beam combining design will not increase the laser spectral line width while enhancing the laser power, reducing the requirements for the unit laser spectral line width, which is very meaningful in some application fields and will further enrich the research of spectral beam combining
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