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Trung DQ, Quang NV, Tran MT, Du NV, Tu N, Hung ND, Viet DX, Anh DD, Huy PT. Single-composition Al 3+-singly doped ZnO phosphors for UV-pumped warm white light-emitting diode applications. Dalton Trans 2021; 50:9037-9050. [PMID: 34160493 DOI: 10.1039/d1dt00971k] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Abstract
The development of full-visible-spectrum phosphors is essential for next-generation light-emitting devices with better light quality. Herein, we report on a novel broad-band-emitting phosphor based on single-composition Al-doped ZnO phosphors. Under the UV excitation of 325 nm, the ZnO : Al phosphor exhibits a full spectrum emission in the visible wavelength range from 400 to 800 nm with a CIE chromaticity coordinate of (0.42, 0.48), a quantum efficiency of 43%, a color rendering index (CRI) of 74, a correlated color temperature (CCT) value of 3873 K and an activation energy of 0.22 eV. A prototype of a UV-pumped warm WLED with a high CRI of 87 and a CCT of 4067 K has been achieved by using only this broad-band-emitting Al3+-doped ZnO phosphor. The obtained results indicate that the single-composition Al3+-singly doped warm white emitting phosphor is a promising candidate for UV-pump warm white light-emitting diodes.
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Affiliation(s)
- D Q Trung
- Phenikaa Institute for Advanced Study (PIAS), Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam. and Phenikaa Research and Technology Institute (PRATI), Phenikaa University, 167 Hoang Ngan, Hanoi 10000, Vietnam and Faculty of Fundamental Sciences, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
| | - N V Quang
- Faculty of Materials Science, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam and Department of Chemistry, Hanoi Pedagogical University 2, Phuc Yen, Vinh Phuc, Vietnam
| | - M T Tran
- Phenikaa Research and Technology Institute (PRATI), Phenikaa University, 167 Hoang Ngan, Hanoi 10000, Vietnam and Faculty of Materials Science, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
| | - N V Du
- Phenikaa Research and Technology Institute (PRATI), Phenikaa University, 167 Hoang Ngan, Hanoi 10000, Vietnam and Faculty of Materials Science, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
| | - N Tu
- Phenikaa Institute for Advanced Study (PIAS), Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam. and Phenikaa Research and Technology Institute (PRATI), Phenikaa University, 167 Hoang Ngan, Hanoi 10000, Vietnam and Faculty of Fundamental Sciences, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
| | - N D Hung
- Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology (HUST), N0 01 Dai Co Viet, Hanoi, Vietnam
| | - Dao Xuan Viet
- Advanced Institute of Science and Technology (AIST), Hanoi University of Science and Technology (HUST), N0 01 Dai Co Viet, Hanoi, Vietnam
| | - D D Anh
- Faculty of Materials Science, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
| | - P T Huy
- Phenikaa Research and Technology Institute (PRATI), Phenikaa University, 167 Hoang Ngan, Hanoi 10000, Vietnam and Faculty of Materials Science, Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Vietnam
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Suzuki M, Thiem VD, Yanai H, Matsubayashi T, Yoshida LM, Tho LH, Minh TT, Anh DD, Kilgore PE, Ariyoshi K. Association of environmental tobacco smoking exposure with an increased risk of hospital admissions for pneumonia in children under 5 years of age in Vietnam. Thorax 2009; 64:484-9. [PMID: 19158124 DOI: 10.1136/thx.2008.106385] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND The association between environmental tobacco smoking (ETS) and childhood pneumonia has not been established in developed or developing countries. A study was conducted to assess the effect and impact of ETS exposure on pneumonia among children in central Vietnam. METHODS A population-based large-scale cross-sectional survey was conducted covering all residents of 33 communes in Khanh Hoa Province, the central part of Vietnam. Information on demographics, socioeconomic status and house environment, including smoking status of each household member, was collected from householders. Hospital admissions for pneumonia among children aged <5 years in each household in the previous 12 months were recorded based on caregiver's report. RESULTS A total of 353 525 individuals living in 75 828 households were identified in the study areas. Of these, 24 781 (7.0%) were aged <5 years. The prevalence of ETS was 70.5% and the period prevalence of hospital admissions for pneumonia was 2.6%. Multiple logistic regression analysis showed that exposure to ETS was independently associated with hospital admissions for pneumonia (adjusted odds ratio 1.55, 95% CI 1.25 to 1.92). The prevalence of tobacco smoking was higher among men than women (51.5% vs 1.5%). It is estimated that 28.7% of childhood pneumonia in this community is attributable to ETS. CONCLUSIONS Children in Vietnam are exposed to substantial levels of ETS which results in 44 000 excess hospital admissions due to pneumonia each year among children aged <5 years.
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Affiliation(s)
- M Suzuki
- Center for International Collaborative Research, Nagasaki University, Nagasaki, Japan
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Kennedy WA, Chang SJ, Purdy K, LE T, Kilgore PE, Kim JS, Anh DD, Huong PLT, Dong BQ, Tan DM, Clemens JD, Ward JI. Incidence of bacterial meningitis in Asia using enhanced CSF testing: polymerase chain reaction, latex agglutination and culture. Epidemiol Infect 2007; 135:1217-26. [PMID: 17274856 PMCID: PMC2870670 DOI: 10.1017/s0950268806007734] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To enhance the detection of bacterial meningitis in an East Asian surveillance study, we employed cerebrospinal fluid (CSF) bacterial culture, latex agglutination (LA) and polymerase chain reaction-enzyme immunoassay (PCR-EIA) testing for Haemophilus influenzae type b (Hib) and Streptococcus pneumoniae (Sp). The sensitivity and specificity of CSF PCR-EIA testing was compared to LA and culture. A meningitis case was defined by one positive result for any of the three tests. The sensitivity of H. influenzae CSF PCR-EIA, LA, and culture was 100%, 40% and 57.5% respectively; and for Sp CSF PCR-EIA, LA and culture, the sensitivity was 100%, 58.3% and 66.7%, respectively. Hib and Sp specificity was 100% by each method. CSF PCR-EIA was more sensitive than culture or LA for the detection of Hib and Sp meningitis cases increasing their incidence by 74% and 50% compared to culture respectively. CSF PCR-EIA should be included for the detection of bacterial meningitis in surveillance studies.
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Affiliation(s)
- W A Kennedy
- Department of Paediatrics, UCLA School of Medicine and the Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, USA.
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Anh DD, Minh TT, Tho LH, Slack MPE, Jodar L, Batmunkh N, Kilgore PE, Talarico CA. Hospital-Based Surveillance for Invasive Pneumococcal Disease in Khanh Hoa Province, Vietnam: Epidemiologic Characteristics and Justification for a Pneumococcal Vaccine. Am J Epidemiol 2006. [DOI: 10.1093/aje/163.suppl_11.s203-a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
To assess whether the Mycobacterium tuberculosis Beijing genotype is emerging in Vietnam, we analyzed 563 isolates from new cases by spoligotyping and examined the association between the genotype and age, resistance, and BCG vaccination status. Three hundred one (54%) patients were infected with Beijing genotype strains. The genotype was associated with younger age (and hence with active transmission) and with isoniazid and streptomycin resistance, but not with BCG vaccination.
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Affiliation(s)
- D D Anh
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
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Trao VT, Huong PL, Thuan AT, Anh DD, Trach DD, Rook GA, Wright EP. Changes in cellular response to mycobacterial antigens and cytokine production patterns in leprosy patients during multiple drug therapy. Immunol Suppl 1998; 94:197-206. [PMID: 9741341 PMCID: PMC1364205 DOI: 10.1046/j.1365-2567.1998.00485.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Changes in Mycobacterium leprae-induced lymphoproliferative responses and mediator release by leprosy patients' lymphocytes were followed during multiple drug therapy (MDT). At the time of diagnosis, multibacillary (MB) patients who did not develop reactions responded to both sonicated M. leprae and synthetic disaccharide coupled to bovine serum albumin (ND-BSA) antigens, but those who would later develop reactions did not respond, even in the presence of added cytokines. The paucibacillary (PB) group initially had high responses to sonicated M. leprae but no response to ND-BSA, even in the presence of added cytokines. In the first year of treatment, the supernatants of PB patients' cell cultures contained factors that enhanced the phytohaemagglutinin (PHA) response of normal cells. In contrast, those MB patients who did not develop reactions at a later stage produced culture supernatants that were inhibitory. Interestingly, the MB patients who later developed reactions during treatment, and did not initially respond to M. leprae, produced supernatants containing enhancing factors, like those of the PB group. Later on in the treatment, all patients had the same patterns: when response to M. leprae decreased from its highest level, inhibitory factors were produced. Further studies revealed that the supernatants which inhibited the PHA response of normal cells contained the active form of transforming growth factor-beta 1, (TGF-beta 1), whatever the disease type or treatment status of the donor. These TGF-beta 1 levels correlated directly with the degree of inhibition. Similarly supernatants that neither inhibited nor enhanced PHA responses contained the highest levels of interleukin-10 (IL-10), while those from treated patients that enhanced contained the lowest levels of interleukin-4 (IL-4) and interferon-gamma (IFN-gamma). These cytokine correlations transcended the conventional disease classification, and imply that all patients pass through a sequence of patterns of immune response during treatment. These treatment-induced changes may explain occasional reports of response patterns at variance with the 'immunological spectrum' of leprosy.
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Affiliation(s)
- V T Trao
- National Institute of Hygiene and Epidemiology, Hanoi, Vietnam
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