17 research outputs found

    Two decades of studies on learning management system in higher education: A bibliometric analysis with Scopus database 2000-2020

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    Over the past twenty years, using learning management systems in higher education has attracted increasing interest from researchers around the globe. In this context, the current study aimed to explore the volume, growth trajectory, and geographic distribution of learning management systems in higher education literature, along with identifying impactful authors, sources, and publications, and highlight emerging research issues. The authors conducted bibliometric analysis on 1334 documents, related to the use of learning management systems in the context of higher education, extracted from Scopus database. The findings show a rapidly growing knowledge base on learning management systems in higher education, especially intensely in the years 2015-2020 and primarily from research in developed societies. This flourishing is consistent with the development trend of international education and the strong development of technology. In addition, the core literature was identified based on the volume of publications and citations. The results also reveal the emerging intellectual structure of the field and provide points of reference for scholars studying the discipline. This paper offers a knowledge map for future research assessments of learning management systems in higher education

    Targeting effect of folate on cancer cell through curcumin carrier nano-system

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    Folate receptor (FR) is well known for its overexpression on surface of various cancer cell lines, which is identical to normal tissue. Folic-based targeting drug delivery systems, therefore, are one of the most effective targeting carriers that effectively bind to FR up-regulated cancer cells. Curcumin was used both for labeling and chemotherapy. The materials were characterized and structurally confirmed by FT-IR spectra, fluorescent images and FE-SEM images. Bioassays were conducted on HeLa and HT29 cancer cell lines after 4 and 12 hours. Results show that folic acid significantly enhanced both targeting efficiency and internalization of curcumin to FR-expressing cancer cells

    The application of (Y,Gd)BO3:Tb3+ and CaGa2S4:Mn2+ phosphors to remote white light-emitting diodes

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    The remote phosphor structure is superior to the conformal phosphor and the in-cup phosphor in terms of lighting efficiency; however, managing the color quality of the remote phosphor structure has been a nuisance to the manufacturers. To address this problem, many researches were conducted and the results suggested that using dual-layer phosphor structure and triple-layer phosphor structure could improve the color quality in remote phosphor structures. The purpose of this article is to study which one between the two configurations mentioned above allows multi-chip white LEDs (WLEDs) to reach highest indexes in color rendering index (CRI), color quality scale (CQS), luminous flux (LF), and color uniformity. The color temperature of the WLEDs used for the experiments in this article is 8500 K. The result of this research shows that the triple-layer phosphor configuration has higher CRI, CQS, and LE and also able to reduce color deviation resulting in better color uniformity. This conclusion can be verified by analyzing the scattering features of the phosphor layers using the Mie-theory. Being verifiable increases the reliability of the research result and makes it a valuable reference for producing better quality WLEDs

    Enhancing the CRI and lumen output for the 6600 K WLED with convex-dual-layer remote phosphor geometry by applying red-emitting MGSR3SI2O8:EU2+,MN2+ phosphor

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    The traditional white LED product established with a single chip and a single phosphor results in a low color rendering index (CRI). The upgrade of LED package is comprised of two chips and one phosphor material and gives the higher CRI while keeping high luminous efficiency. Based on previous findings, the research paper performs the application of the two chips and two phosphors to enhance the color tunability of LEDs with different amounts and intensities of the two employed phosphors. Additionally, a color design model is built to serve the purpose of bettering the color fine-tuning of the white-light LED module. The maximum value of the difference between the measured CIE 1931 color coordinates and that of the simulated model is approximately 0.0063 around the 6600 K correlated color temperature (CCT). From the results, this study offers a quick approach to achieve the color fine tuning of a white-light LED module with a high CRI and luminous efficiency

    Dual-layer remote phosphor structure: a novel technique to enhance the color quality scale and luminous flux of WLEDs

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    The effects of red light-emitting phosphor CaMgSi2O6:Eu2+,Mn2+ on the optical properties of single-layer remote phosphor structure (SRPS) and dual-layer remote phosphor structure (DRPS) are the focus of this study. The differences in color quality and luminous flux (LF) of white light-emitting diodes (WLEDs) between these two structures are also revealed and demonstrated based on the Mie theory. SRPS consists of one mixed phosphor layer betweenCaMgSi2O6:Eu2+,Mn2+ andYAG:Ce3+particles, while DRPS includes two separated layers: red phosphor layer and yellow phosphor layer. In this work, 5% SiO2 is added into the phosphor layers to increase scattering abilities. Discrepancies in structures greatly affect the optical characteristics of WLEDs. The results showed that the color rendering index (CRI) increased with the concentration in both structures with nearly equal values. Meanwhile, color quality scale (CQS) of DPRS is 74 at ACCTs ranging from 5600K to 8500K, higher than CQS of SRPS which is only 71 at 8500K. In addition, the luminous flux of DRPS is significantly higher than SRPS at 2% -14% of CaMgSi2O6:Eu2+,Mn2+. In summary, DRPS is better for color quality and lumen outputin comparison to SRPS and adding the right amount of red phosphor can enhance CQS and LF

    The Status of Educational Sciences In Vietnam: A Bibliometric Analysis From Clarivate Web Of Science Database Between 1991 And 2018

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    Since 2013, Vietnam has implemented a plan to reform the whole education sector. However, there is little understanding on the status of educational research in Vietnam, which may lay the foundation for such plan. Thus, this research aims to analyze the whole picture of educational research from Vietnam, as seen from the Clarivate Web of Science (WOS) database: 215 publications were recorded, ranging from 1991 to 2018. These 215 publications were further analyzed from five perspectives: 1) number of publications by year; 2) research fields and levels of education; 3) top institutions with the highest number of publications; 4) international collaboration; and 5) quality. Some of the most notable results are: 1) the educational sciences in Vietnam have been still under-developed until recently; 2) among different research topics research among educational sciences, some (e.g., Vocational Education and Training or Early Childhood Education) seemed to be overlooked whereas others (e.g., Higher Education and Teaching and Learning) seemed to receive more attention from educational scholars; 3) all the most major education – specialized universities did not appear among the top five institutions with highest number of publications; 4) Australia, Thailand, the USA, New Zealand and China were the countries with the highest number of co-publications with Vietnamese researchers; and 5) The majority of publications belonged to low-ranked journals. Implications would be withdrawn for Vietnamese policymakers, education leaders, educational researchers and teachers in order to adjust their policies and/or action plans; thus, enhancing the performance and impacts of educational research in the future

    Targeting effect of folate on cancer cell through curcumin carrier nano-system

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    Folate receptor (FR) is well known for its overexpression on surface of various cancer cell lines, which is identical to normal tissue. Folic-based targeting drug delivery systems, therefore, are one of the most effective targeting carriers that effectively bind to FR up-regulated cancer cells. Curcumin was used both for labeling and chemotherapy. The materials were characterized and structurally confirmed by FT-IR spectra, fluorescent images and FE-SEM images. Bioassays were conducted on HeLa and HT29 cancer cell lines after 4 and 12 hours. Results show that folic acid significantly enhanced both targeting efficiency and internalization of curcumin to FR-expressing cancer cells

    Safety and efficacy of fluoxetine on functional outcome after acute stroke (AFFINITY): a randomised, double-blind, placebo-controlled trial

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    Background Trials of fluoxetine for recovery after stroke report conflicting results. The Assessment oF FluoxetINe In sTroke recoverY (AFFINITY) trial aimed to show if daily oral fluoxetine for 6 months after stroke improves functional outcome in an ethnically diverse population. Methods AFFINITY was a randomised, parallel-group, double-blind, placebo-controlled trial done in 43 hospital stroke units in Australia (n=29), New Zealand (four), and Vietnam (ten). Eligible patients were adults (aged ≥18 years) with a clinical diagnosis of acute stroke in the previous 2–15 days, brain imaging consistent with ischaemic or haemorrhagic stroke, and a persisting neurological deficit that produced a modified Rankin Scale (mRS) score of 1 or more. Patients were randomly assigned 1:1 via a web-based system using a minimisation algorithm to once daily, oral fluoxetine 20 mg capsules or matching placebo for 6 months. Patients, carers, investigators, and outcome assessors were masked to the treatment allocation. The primary outcome was functional status, measured by the mRS, at 6 months. The primary analysis was an ordinal logistic regression of the mRS at 6 months, adjusted for minimisation variables. Primary and safety analyses were done according to the patient's treatment allocation. The trial is registered with the Australian New Zealand Clinical Trials Registry, ACTRN12611000774921. Findings Between Jan 11, 2013, and June 30, 2019, 1280 patients were recruited in Australia (n=532), New Zealand (n=42), and Vietnam (n=706), of whom 642 were randomly assigned to fluoxetine and 638 were randomly assigned to placebo. Mean duration of trial treatment was 167 days (SD 48·1). At 6 months, mRS data were available in 624 (97%) patients in the fluoxetine group and 632 (99%) in the placebo group. The distribution of mRS categories was similar in the fluoxetine and placebo groups (adjusted common odds ratio 0·94, 95% CI 0·76–1·15; p=0·53). Compared with patients in the placebo group, patients in the fluoxetine group had more falls (20 [3%] vs seven [1%]; p=0·018), bone fractures (19 [3%] vs six [1%]; p=0·014), and epileptic seizures (ten [2%] vs two [<1%]; p=0·038) at 6 months. Interpretation Oral fluoxetine 20 mg daily for 6 months after acute stroke did not improve functional outcome and increased the risk of falls, bone fractures, and epileptic seizures. These results do not support the use of fluoxetine to improve functional outcome after stroke

    55 Khoa học Giáo dục Việt Nam

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    “55 năm khoa học giáo dục Việt Nam - một phân tích từ dữ liệu Scopus ” là cuốn sách được trình bày dưới dạng báo cáo trắc lượng thư mục khoa học về công bố quốc tế trong lĩnh vực khoa học giáo dục của các tác giả và cơ sở nghiên cứu Việt Nam. Dựa trên dữ liệu thu được từ cơ sở Scopus, cuốn sách khắc họa bức tranh tổng thể về số lượng, cộng đồng nghiên cứu, các nguồn tạp chí, mạng lưới hợp tác, các đơn vị nghiên cứu, các chủ đề và lĩnh vực nghiên cứu được công bố trên các tạp chí khoa học uy tín của các nhà khoa học Việt Nam. Cùng với đó, cuốn sách đưa ra những nhận định về xu hướng tương lai của lĩnh vực này và điểm qua những công trình tiêu biểu nhất đánh dấu các bước tiến trong chặng đường phát triển của lĩnh vực

    Physical activity and social support are associated with quality of life in middle-aged women

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    Purposes: This cross-sectional study assessed the quality of life and related factors of Vietnamese women during perimenopause in terms of vasomotor, psychosocial, physical, and sexual aspects. Materials and methods: A cross-sectional study on 400 middle-aged women was conducted in Hung Yen, a delta province in Vietnam. Data about socioeconomic characteristics, daily activity patterns, quality of life in terms of vasomotor, psychosocial, physical, and sexual aspects, and level of social support were collected. Tobit multivariate regression model was used to identify factors related to the quality of life among participants. Results: The symptoms of perimenopause appeared to worsen with the increase of age and the existence of such health issues as migraine and diabetes. Meanwhile, exercises, recreational activities, and social support appeared to alleviate the negative impact of perimenopausal symptoms on women. Conclusions: It is important to address the care needs of women during perimenopausal age, especially their sexual well-being, and development of specific healthcare services and programs focusing on sport, entertainment, and support for women in perimenopause should be facilitated
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