656 research outputs found

    THE RELATIONSHIP BETWEEN TEACHERS' PERCEPTIONS OF THE PRINCIPAL'S TRANSFORMATIONAL LEADERSHIP AND THEIR JOB SATISFACTION IN WULANCHABU HENGSHUI ZHUOYUAN MIDDLE SCHOOL, CHINA

    Get PDF
    This study aimed to determine the relationship between teachers' perceptions of the principal's transformational leadership and their job satisfaction at Wulan Chabu Hengshui Zhuoyuan Middle School, China. The study surveyed 61 full-time teachers in the academic year of 2020. The findings showed that the teachers' perceptions of the principal's transformational leadership style was high. In contrast, the teachers' job satisfaction level at Wulan Chabu Hengshui Zhuoyuan Middle School was moderate. The correlation analysis result showed a strong positive relationship between teachers' perceptions of the principal's transformational leadership style and their job satisfaction at Wulan Chabu Hengshui Zhuoyuan Middle School, China, as the r = 0.945, p < 0.001

    Anti-trypanosomal effect of Malva sylvestris (Malvaceae) extract on a Trypanosoma brucei brucei-infected mouse model of sleeping sickness

    Get PDF
    Purpose: To evaluate the antitrypanosomal activity of Malva sylvestris (MS) extract in a Trypanosoma brucei brucei-infected  mouse model of sleeping sickness.Methods: Sleeping sickness was induced by the intraperitoneal injection of Trypanosoma brucei brucei infected blood in mice.  Confirmation of parasitaemia was performed by estimating the parasite count in the plasma on the 12th day after inoculation. All the mice were divided into five groups: control group that received neither infection nor treatment; negative control that was  infected with the parasite but did not receive treatment; MS-treated group that receive MS extract (250 and 500 mg/kg, ip) and standard (STD) group that received levamisole (7.5 mg/kg, ip) for 7 days after the development of parasitaemia. A further parasite count was performed in the blood and cerebrospinal fluid (CSF) after the treatment period. Humoral antibody response,  delayed hypersensitivity reaction, and mobilization of leucocytes were determined after the treatment period in SRBC-sensitized mice.Results: The results indicate that treatment with MS significantly decreased body weight and parasite count in the blood and CSF of mice with Trypanosoma brucei brucei-induced sleeping sickness compared with that in the negative control group. There was a significant increase in paw swelling and decrease in secondary antibody in the MS-treated group compared with that in the  negative control group. However, treatment with MS extract also enhanced the mobilization of the total leucocyte count compared with that in the negative control group.Conclusion: The results demonstrate the anti-trypanosomal activity of Malva sylvestris extract via immunomodulation in a  Trypanosoma brucei brucei-infected mouse model of sleeping sickness.Keywords: Malva sylvestris, Trypanosoma brucei brucei, Sleeping sickness, Immunomodulatory activity, Delayed hypersensitivity reactio

    Covalent-linked porphyrin/single-walled carbon nanotube nanohybrids: synthesis and influence of porphyrin substituents on nonlinear optical performance

    Get PDF
    Electron-withdrawing 4-cyanophenyl-, electronically innocent phenyl-, and electron-donating 4-dimethylaminophenyl-functionalized porphyrin/single-walled carbon nanotube (SWCNT) nanohybrids have been synthesized and characterized by ultraviolet–visible absorption, steady-state fluorescence, Fourier transform infrared, and Raman spectroscopies, X-ray photoelectron spectroscopy, scanning electron microscopy, transmission electron microscopy and thermogravimetric analysis. Nonlinear optical (NLO) studies using the Z-scan technique revealed that both the cyano (CN) and the dimethylamino (DMA) substituents have a positive effect in optimizing the optical limiting performance of the SWCNT–porphyrin nanohybrids, owing to increased reverse saturable absorption (RSA) of the porphyrin moieties after functionalization by CN or DMA. In comparison with CN, the DMA group has a more positive influence on the porphyrin excited states and thereby the RSA and NLO activity.This research was financially supported by the National Natural Science Foundation of China (Nos. 51432006 and 51172100), the Ministry of Education and the State Administration of Foreign Experts Affairs for the 111 Project (No. B13025), the Ministry of Education of China for the Changjiang Innovation Research Team (No. IRT14R23), 100 Talents Program of CAS, and the Ministry of Science and Technology of China for International Science Linkages Program (2011DFG52970). M.G.H. and C.Z. thank the Australian Research Council for support

    A Higher Dietary Inflammatory Index Score Is Associated With a Higher Risk of Breast Cancer Among Chinese Women: A Case–Control Study

    Get PDF
    Previous studies have investigated the association between dietary inflammatory potential and the development of cancer. For breast cancer the results have been equivocal. The present study aimed to investigate whether higher Dietary Inflammatory IndexTM (DII) scores were associated with increased risk of breast cancer among Chinese women. A total of 867 cases and 824 controls were recruited into the present case–control study from September 2011 to February 2016. DII scores were computed based on baseline dietary intake assessed by a validated 81-item FFQ. The OR and 95 % CI were assessed by multivariable logistic regression after adjusting for various potential confounders. DII scores in this study ranged from −5·87 (most anti-inflammatory score) to +5·71 (most proinflammatory score). A higher DII score was associated with a higher breast cancer risk (adjusted ORquartile 4 v. 1 2·28; 95 % CI 1·71, 3·03; adjusted ORcontinuous 1·40; 95 %CI 1·25, 1·39). In stratified analyses, positive associations also were observed except for underweight women or women with either oestrogen receptor+ or progesterone receptor+ status (but not both). Results from this study indicated that higher DII scores, corresponding to more proinflammatory diets, were positively associated with breast cancer risk among Chinese women

    Evaluating team-based, lecture-based, and hybrid learning methods for neurology clerkship in China: a method-comparison study

    Get PDF
    BACKGROUND: Neurology is complex, abstract, and difficult for students to learn. However, a good learning method for neurology clerkship training is required to help students quickly develop strong clinical thinking as well as problem-solving skills. Both the traditional lecture-based learning (LBL) and the relatively new team-based learning (TBL) methods have inherent strengths and weaknesses when applied to neurology clerkship education. However, the strengths of each method may complement the weaknesses of the other. Combining TBL with LBL may produce better learning outcomes than TBL or LBL alone. We propose a hybrid method (TBL + LBL) and designed an experiment to compare the learning outcomes with those of pure LBL and pure TBL. METHODS: One hundred twenty-seven fourth-year medical students attended a two-week neurology clerkship program organized by the Department of Neurology, Sun Yat-Sen Memorial Hospital. All of the students were from Grade 2007, Department of Clinical Medicine, Zhongshan School of Medicine, Sun Yat-Sen University. These students were assigned to one of three groups randomly: Group A (TBL + LBL, with 41 students), Group B (LBL, with 43 students), and Group C (TBL, with 43 students). The learning outcomes were evaluated by a questionnaire and two tests covering basic knowledge of neurology and clinical practice. RESULTS: The practice test scores of Group A were similar to those of Group B, but significantly higher than those of Group C. The theoretical test scores and the total scores of Group A were significantly higher than those of Groups B and C. In addition, 100% of the students in Group A were satisfied with the combination of TBL + LBL. CONCLUSIONS: Our results support our proposal that the combination of TBL + LBL is acceptable to students and produces better learning outcomes than either method alone in neurology clerkships. In addition, the proposed hybrid method may also be suited for other medical clerkships that require students to absorb a large amount of abstract and complex course materials in a short period, such as pediatrics and internal medicine clerkships

    Semantics-enhanced Cross-modal Masked Image Modeling for Vision-Language Pre-training

    Full text link
    In vision-language pre-training (VLP), masked image modeling (MIM) has recently been introduced for fine-grained cross-modal alignment. However, in most existing methods, the reconstruction targets for MIM lack high-level semantics, and text is not sufficiently involved in masked modeling. These two drawbacks limit the effect of MIM in facilitating cross-modal semantic alignment. In this work, we propose a semantics-enhanced cross-modal MIM framework (SemMIM) for vision-language representation learning. Specifically, to provide more semantically meaningful supervision for MIM, we propose a local semantics enhancing approach, which harvest high-level semantics from global image features via self-supervised agreement learning and transfer them to local patch encodings by sharing the encoding space. Moreover, to achieve deep involvement of text during the entire MIM process, we propose a text-guided masking strategy and devise an efficient way of injecting textual information in both masked modeling and reconstruction target acquisition. Experimental results validate that our method improves the effectiveness of the MIM task in facilitating cross-modal semantic alignment. Compared to previous VLP models with similar model size and data scale, our SemMIM model achieves state-of-the-art or competitive performance on multiple downstream vision-language tasks.Comment: Accepted to LREC-COLING 202

    Researches on Heat Pump System using Rotary Compressor in Electric Vehicle

    Get PDF
    In China, electric vehicles (EVs) are becoming increasing popular. With several years practical operation experiences, a lot of news reports reveal the existing electrical supplementary heating can dramatically impact the driving range of EVs under cold weather in north China. The high efficient electric heat pump system has become the research hotspot, but previous research show the heat pump operation could supply adequate heating capacity only in mild weather conditions when the working fluid is R134a. Since the user can’t change environment temperature, choose a high pressure working fluid to have better heating performance become a realistic choice. Now the aluminum scroll compressor is wildly used in EVs, but because of the material and structure, it can’t endure the long term high pressure operation. This paper adopted the low cost steel rotary compressor and high pressure working fluid to build the EV heat pump system. The heat pump cycles using R134a, R407c and R290 have been theoretically analyzed; the rotary compressor has been redesigned to respectively apply the R134a, R407c and R290; the heat pump test rig has been build; three combinations (compressor, oil and working fluid) under the same cold weather conditions have been experimentally researched. Results showed the rotary compressor with the high pressure working fluid applied system can generate adequate heating capacity with less energy
    • …
    corecore