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Monteiro MLG, Torres Neto L, Mutz YDS, Silva CRD, Conte-Junior CA. Optimizing UVC-LED application to improve the shelf life of vacuum-packed refrigerated stored Nile tilapia (Oreochromis niloticus) fillets. J Food Sci 2024; 89:552-565. [PMID: 38078775 DOI: 10.1111/1750-3841.16874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 10/24/2023] [Accepted: 11/20/2023] [Indexed: 01/15/2024]
Abstract
Although ultraviolet-C light-emitting diode (UVC-LED) has proven antimicrobial effectiveness doses needed to reach it cause adverse effects on the physicochemical quality of fish, and thus, optimization studies are crucial to boost its industrial application. This study aimed to identify optimal UVC-LED conditions for maximum shelf life extension with the least possible quality changes of refrigerated stored tilapia fillets from a central composite rotatable design (CCRD). UVC-LED powers (1, 1.38, and 1.58 mW/cm2 ) and times (500, 1800, and 2700 s) were set on the CCRD, which generated 11 treatments, including three replicate experiments. Treatments were analyzed for total aerobic psychrotrophic count, lipid oxidation, instrumental color, and texture parameters on days 0, 2, 4, 7, 11, and 14. The UVC-LED affected shelf life and physicochemical parameters in a nonlinear fashion. UVC-LED-treated fish had increased shelf life by 2.80-4.76 days and increase or decrease in lipid oxidation (0.025-0.276 mg of malondialdehyde [MDA]/kg), total color change (∆E = 3.47-9.06), and hardness (1.31-8.51 N) over the refrigerated storage depending on specific UVC-LED conditions applied. The optimal UVC-LED condition was 0.97 mW/cm2 with 2503.6 s (2428.50 mJ/cm2 ), which increased the fillet's shelf life by 2.5-fold (2 days) while maintaining quality closer to the original throughout refrigerated storage, resulting in ∆E < 5, an increase of only 0.05 mg of MDA/kg, and preservation of the decrease in hardness by 3.38 N compared to its control counterparts. Therefore, it represents an eco-friendly technology that can easily scaled industrially to enhance the sustainable fish production chain. PRACTICAL APPLICATION: The high fish perishability is a global concern due to food safety risks and waste generation impacting the environment adversely, especially nowadays, where fish production and consumption have increased, and there are more evident efforts to sustainable production. UVC-LED is an eco-friendly technology with proven antimicrobial effectiveness but doses needed to reach this effect enhance oxidative degradation. Despite that, optimization studies concerning the maximum shelf life extension while retaining the physicochemical quality of refrigerated stored fish are a gap in the literature and a barrier to its industrial application. Our findings are helpful in sustainably enhancing the fish production chain.
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Affiliation(s)
- Maria Lúcia Guerra Monteiro
- Graduate Program in Food Science (PPGCAL), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Center for Food Analysis (NAL), Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Laboratory of Advanced Analysis in Biochemistry and Molecular Biology (LAABBM), Department of Biochemistry, Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Graduate Program in Veterinary Hygiene (PPGHV), Faculty of Veterinary Medicine, Fluminense Federal University (UFF), Vital Brazil Filho, Niterói, Brazil
| | - Luiz Torres Neto
- Graduate Program in Food Science (PPGCAL), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Center for Food Analysis (NAL), Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Laboratory of Advanced Analysis in Biochemistry and Molecular Biology (LAABBM), Department of Biochemistry, Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
| | - Yhan da Silva Mutz
- Graduate Program in Food Science (PPGCAL), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Center for Food Analysis (NAL), Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Laboratory of Advanced Analysis in Biochemistry and Molecular Biology (LAABBM), Department of Biochemistry, Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
| | - Carolina Ramos da Silva
- Center for Food Analysis (NAL), Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Laboratory of Advanced Analysis in Biochemistry and Molecular Biology (LAABBM), Department of Biochemistry, Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Graduate Program in Chemistry (PGQu), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
| | - Carlos Adam Conte-Junior
- Graduate Program in Food Science (PPGCAL), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Center for Food Analysis (NAL), Technological Development Support Laboratory (LADETEC), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Laboratory of Advanced Analysis in Biochemistry and Molecular Biology (LAABBM), Department of Biochemistry, Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Graduate Program in Veterinary Hygiene (PPGHV), Faculty of Veterinary Medicine, Fluminense Federal University (UFF), Vital Brazil Filho, Niterói, Brazil
- Graduate Program in Chemistry (PGQu), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
- Graduate Program in Biochemistry (PPGBq), Institute of Chemistry (IQ), Federal University of Rio de Janeiro (UFRJ), Cidade Universitária, Rio de Janeiro, Brazil
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Solís-Cisneros HI, Hu Y, Camas-Anzueto JL, Grajales-Coutiño R, Anwar AR, Martínez-Revuelta R, Hernández-de-León HR, Hernández-Gutiérrez CA. Theoretical and Computational Analysis of a Wurtzite-AlGaN DUV-LED to Mitigate Quantum-Confined Stark Effect with a Zincblende Comparison Considering Mg- and Be-Doping. Nanomaterials (Basel) 2022; 12:4347. [PMID: 36500970 PMCID: PMC9735936 DOI: 10.3390/nano12234347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/08/2022] [Revised: 11/29/2022] [Accepted: 12/02/2022] [Indexed: 06/17/2023]
Abstract
In this work, an AlGaN-based Deep-Ultraviolet Light-Emitting Diode structure has been designed and simulated for the zincblende and wurtzite approaches, where the polarization effect is included. DFT analysis was performed to determine the band gap direct-to-indirect cross-point limit, AlN carrier mobility, and activation energies for p-type dopants. The multiple quantum wells analysis describes the emission in the deep-ultraviolet range without exceeding the direct-to-indirect bandgap cross-point limit of around 77% of Al content. Moreover, the quantum-confined Stark effect on wavefunctions overlapping has been studied, where Al-graded quantum wells reduce it. Both zincblende and wurtzite have improved electrical and optical characteristics by including a thin AlGaN with low Al content. Mg and Be acceptor activation energies have been calculated at 260 meV and 380 meV for Be and Mg acceptor energy, respectively. The device series resistance has been decreased by using Be instead of Mg as the p-type dopant from 3 kΩ to 0.7 kΩ.
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Affiliation(s)
- Horacio I. Solís-Cisneros
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
| | - Yaoqiao Hu
- Department of Materials Science and Engineering, The University of Texas at Dallas, Richardson, TX 75080, USA
| | - Jorge L. Camas-Anzueto
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
| | - Rubén Grajales-Coutiño
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
| | - Abdur-Rehman Anwar
- Laboratory of Nitride Semiconductor Physics, Institute of High-Pressure Physics, Polish Academy of Sciences, Sokolowska 29/37, 01-142 Warsaw, Poland
| | - Rubén Martínez-Revuelta
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
| | - Héctor R. Hernández-de-León
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
| | - Carlos A. Hernández-Gutiérrez
- Optomechatronics Group, Tecnológico Nacional de México Campus Tuxtla Gutiérrez, Carretera Panamericana Km 1080, Tuxtla Gutiérrez 29050, Mexico
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Song H, Dang YM, Ha S, Ha JH. Evaluation of Virucidal Efficacy of Human Norovirus Using Combined Sprayed Slightly Acidic Electrolyzed Water and Ultraviolet C-Light-Emitting Diode Irradiation Treatment Based on Optimized Capture Assay for Quantitative RT-qPCR. Front Microbiol 2022; 13:841108. [PMID: 35547136 PMCID: PMC9082547 DOI: 10.3389/fmicb.2022.841108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Accepted: 02/07/2022] [Indexed: 11/26/2022] Open
Abstract
Slightly acidic electrolyzed water (SAEW), an effective non-thermal virucidal treatment, is used widely to prevent infectious viral cross-contamination. Surface disinfection technologies using ultraviolet C-light-emitting diode (UVC-LED) irradiation have recently attracted considerable attention. The SAEW sprayer technique is an efficient approach to preventing the spread of infectious viral pathogens in the public healthcare sector. Therefore, we investigated a small-scale system comprising sprayed SAEW disinfection combined with UVC-LED irradiation to inactivate the human norovirus (HuNoV) in the environment. A stainless-steel surface was inoculated with a HuNoV genogroup II genotype 4 (GII.4) to achieve maximum reduction values of 3.21 log10 genomic copies. For optimal disinfection conditions, the response surface methodology based on the Box–Behnken design revealed that the specific treatment conditions for inactivation of HuNoV GII.4 were an SAEW droplet volume of 180 μL, 30 ppm available chlorine concentration of SAEW, and a UVC-LED exposure dose of 2 mJ/cm2. The results indicate that the combined disinfection treatment could efficiently prevent the spread of HuNoVs in environment. Furthermore, the quadratic polynomial equations of the 3-D response surface can be employed to predict the effects of combined disinfection treatment on HuNoV contamination on environmental surfaces. Therefore, sprayed SAEW disinfection combined with UVC-LED irradiation proposed in this study may offer insights for designing optimal control strategies and techniques to prevent the transmission of infectious diseases, particularly HuNoV.
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Affiliation(s)
- Hyeyeon Song
- Hygienic Safety and Distribution Research Group, World Institute of Kimchi, Gwangju, South Korea
| | - Yun-Mi Dang
- Hygienic Safety and Distribution Research Group, World Institute of Kimchi, Gwangju, South Korea
| | - Sanghyun Ha
- Hygienic Safety and Distribution Research Group, World Institute of Kimchi, Gwangju, South Korea
| | - Ji-Hyoung Ha
- Hygienic Safety and Distribution Research Group, World Institute of Kimchi, Gwangju, South Korea
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Park E, Park S, Hwang JH, Jung AH, Park SH, Yoon Y. Evaluation of Non-Thermal Decontamination Processes to Have the Equivalence of Thermal Process in Raw Ground Chicken. Food Sci Anim Resour 2022; 42:142-152. [PMID: 35028580 PMCID: PMC8728503 DOI: 10.5851/kosfa.2021.e69] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 10/24/2021] [Accepted: 10/30/2021] [Indexed: 11/19/2022] Open
Abstract
The present study was aimed at examining the antibacterial effects of non-thermal
decontamination processes, which are equivalent to thermal treatment, to ensure
microbiological safety of raw ground chicken. Escherichia coli
or Salmonella were inoculated into 25 g of raw ground chicken
samples. The raw ground chicken samples were non-treated or treated with high
hydrostatic pressure (HHP) at 500 MPa (1–7 min), light-emitting diode
(LED) irradiation at 405 nm wavelength (30–120 min), and heat at
70°C, 90°C (1–60 min), and 121°C (1–15 min).
E. coli and Salmonella cell counts were
enumerated after treatments. Moreover, the color parameters of treated raw
ground chicken were analyzed. HHP treatment reduced E. coli and
Salmonella cell counts by more than 5 Log CFU/g and more
than 6 Log CFU/g after 7 min and 1 min, respectively; these effects were
equivalent to those of thermal treatment. However, LED irradiation reduced
Salmonella cell counts by only 0.9 Log CFU/g after 90 min
of treatment, and it did not reduce E. coli cell counts for 90
min. Compared with those of the non-treated samples, the
ΔE (total color difference) values of the samples
treated with HHP were high, whereas the ΔE values of the
samples treated with LED irradiation were low (1.93–2.98). These results
indicate that despite color change by HHP treatment, HHP treatment at 500 MPa
could be used as a non-thermal decontamination process equivalent to thermal
treatment.
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Affiliation(s)
- Eunyoung Park
- Department of Food and Nutrition, Sookmyung Women's University, Seoul 04310, Korea
| | - Sangeun Park
- Department of Food and Nutrition, Sookmyung Women's University, Seoul 04310, Korea
| | - Jeong Hyeon Hwang
- Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, Korea
| | - Ah Hyun Jung
- Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, Korea
| | - Sung Hee Park
- Department of Food Science and Technology, Seoul National University of Science and Technology, Seoul 01811, Korea
| | - Yohan Yoon
- Department of Food and Nutrition, Sookmyung Women's University, Seoul 04310, Korea.,Risk Analysis Research Center, Sookmyung Women's University, Seoul 04310, Korea
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Fradkin O, Mamane H, Kaplan A, Menashe O, Kurzbaum E, Betzalel Y, Avisar D. UV-LED Combined with Small Bioreactor Platform (SBP) for Degradation of 17α-Ethynylestradiol (EE2) at Very Short Hydraulic Retention Time. Materials (Basel) 2021; 14:ma14205960. [PMID: 34683555 PMCID: PMC8538786 DOI: 10.3390/ma14205960] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/01/2021] [Revised: 10/02/2021] [Accepted: 10/07/2021] [Indexed: 11/16/2022]
Abstract
Degradation of 17α-ethynylestradiol (EE2) and estrogenicity were examined in a novel oxidative bioreactor (OBR) that combines small bioreactor platform (SBP) capsules and UV-LED (ultraviolet light emission diode) simultaneously, using enriched water and secondary effluent. Preliminary experiments examined three UV-LED wavelengths-267, 279, and 286 nm, with (indirect photolysis) and without (direct photolysis) H2O2. The major degradation wavelength for both direct and indirect photolysis was 279 nm, while the major removal gap for direct vs. indirect degradation was at 267 nm. Reduction of EE2 was observed together with reduction of estrogenicity and mineralization, indicating that the EE2 degradation products are not estrogens. Furthermore, slight mineralization occurred with direct photolysis and more significant mineralization with the indirect process. The physical-biological OBR process showed major improvement over other processes studied here, at a very short hydraulic retention time. The OBR can feasibly replace the advanced oxidation process of UV-LED radiation with catalyst in secondary sedimentation tanks with respect to reduction ratio, and with no residual H2O2. Further research into this OBR system is warranted, not only for EE2 degradation, but also to determine its capabilities for degrading mixtures of pharmaceuticals and pesticides, both of which have a significant impact on the environment and public health.
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Affiliation(s)
- Oran Fradkin
- School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel; (O.F.); (H.M.); (Y.B.)
- The Hydrochemistry Laboratory, The Water Research Center, Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel;
| | - Hadas Mamane
- School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel; (O.F.); (H.M.); (Y.B.)
| | - Aviv Kaplan
- The Hydrochemistry Laboratory, The Water Research Center, Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel;
| | - Ofir Menashe
- Water Industry Engineering Department, Achi Racov Engineering School, Kinneret College on the Sea of Galilee, M.P. Emek Ha’Yarden 15132, Israel;
- BioCastle Water Technologies Ltd., Tzemach Industries Central Area, Jordan Valley 15105, Israel
| | - Eyal Kurzbaum
- Shamir Research Institute, University of Haifa, Qatzrin 12900, Israel;
| | - Yifaat Betzalel
- School of Mechanical Engineering, Faculty of Engineering, Tel Aviv University, Tel Aviv 69978, Israel; (O.F.); (H.M.); (Y.B.)
| | - Dror Avisar
- The Hydrochemistry Laboratory, The Water Research Center, Porter School of the Environment and Earth Sciences, Faculty of Exact Sciences, Tel Aviv University, Tel Aviv 69978, Israel;
- Correspondence:
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Wei Y, Zheng W, Li B, Tong Q, Shi H, Li X. Effects of B-Wave Ultraviolet Supplementation Using Light-Emitting Diodes on Caged Laying Hens during the Later Phase of the Laying Cycle. Animals (Basel) 2019; 10:E15. [PMID: 31861728 DOI: 10.3390/ani10010015] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Revised: 12/15/2019] [Accepted: 12/16/2019] [Indexed: 01/11/2023] Open
Abstract
Caged laying hens are prone to calcium deficiencies, resulting in osteoporosis and egg quality deterioration during the later phase of the laying cycle. Fluorescent light and light-emitting diodes (LEDs), which are widely used in poultry houses now, are both deficient in ultraviolet (UV) light, the lack of which is detrimental to chickens' welfare and health. This study was conducted to investigate the effects of UVB light supplementation using LEDs on the bone traits, blood parameters, laying performance, and egg quality for caged laying hens at 68-75 weeks. In total, 120 Jingfen laying hens were randomly assigned to four different groups, with three replicates in each group (10 hens in each cage as a replicate). UVB-LED lamps installed under the feed troughs were used to provide UVB light (296-316 nm) for the birds in the three treatment groups (1 h, 2 h, and 3 h UVB supplementation per day, respectively), while the control group was not exposed to UVB-LED light. Bone traits, egg quality, and amounts of calcium (Ca), phosphorus (P), 25-hydroxyvitamin D3 (25(OH)D3), 1,25-dihydroxyvitamin D3 (1,25(OH)2D3), and 7-dehydrocholesterol (7-DHC) in both the serum and egg yolks were tested during the experiment. The results demonstrated that UVB-LED exposure significantly increased the bone mineral density (BMD), egg production, and yolk 1,25(OH)2D3 concentrations (p < 0.05), and reduced the content of serum 7-DHC (p < 0.05), especially in the 2 h/day group; however, it did not improve egg quality, vitamin D metabolites, or photoproducts in the serum and yolk 25(OH)2D3 concentrations (p > 0.05). This study concluded that UVB supplementation using LEDs had a positive effect on caged laying hens during the later phase of the laying cycle.
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Kim KH, Lee TH, Kim TG. AlN/ITO-Based Hybrid Electrodes with Conducting Filaments: Their Application to Ultraviolet Light-Emitting Diodes. ACS Appl Mater Interfaces 2017; 9:24357-24364. [PMID: 28671809 DOI: 10.1021/acsami.7b06362] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
A hybrid-type transparent conductive electrode (H-TCE) structure comprising an AlN rod array with conducting filaments (CFs) and indium tin oxide (ITO) films is proposed to improve both current injection and distribution as well as optical transmittance in the UV region. These CFs, generated in UV-transparent AlN rod areas using an electric field, can be used as conducting paths for carrier injection from a metal to a semiconductor such as p-(Al)GaN, which allows perfect Ohmic behavior with high transmittance (>95% at 365 nm) to be obtained. In addition, conduction across AlN rods and Ohmic conduction mechanisms are investigated by analyzing AlN rods and AlN rod/p-AlGaN film interfaces. We apply these H-TCEs to three near-UV light-emitting diodes (LEDs) (385 nm LEDs with p-GaN and p-AlGaN terminated surfaces and 365 nm LED with p-AlGaN terminated surface). We confirm that the light power outputs increase by 66%, 79%, and 103%, whereas the forward voltages reduce by 5.6%, 10.2%, and 8.6% for 385 nm p-GaN terminated, 385 nm p-AlGaN terminated, and 365 nm p-AlGaN terminated LEDs with H-TCEs, respectively, compared to LEDs with reference ITOs.
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Affiliation(s)
- Kyeong Heon Kim
- School of Electrical Engineering, Korea University , Seoul 136-701, Republic of Korea
| | - Tae Ho Lee
- School of Electrical Engineering, Korea University , Seoul 136-701, Republic of Korea
| | - Tae Geun Kim
- School of Electrical Engineering, Korea University , Seoul 136-701, Republic of Korea
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Hutchens MP, Drennan SL, Cambronne ED. Calibration of optimal use parameters for an ultraviolet light-emitting diode in eliminating bacterial contamination on needleless connectors. J Appl Microbiol 2015; 118:1298-305. [PMID: 25801979 DOI: 10.1111/jam.12802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/06/2015] [Accepted: 03/14/2015] [Indexed: 11/30/2022]
Abstract
AIMS Needleless connectors may develop bacterial contamination and cause central-line-associated bloodstream infections (CLABSI) despite rigorous application of best-practice. Ultraviolet (UV) light-emitting diodes (LED) are an emerging, increasingly affordable disinfection technology. We tested the hypothesis that a low-power UV LED could reliably eliminate bacteria on needleless central-line ports in a laboratory model of central-line contamination. METHODS AND RESULTS Needleless central-line connectors were inoculated with Staphylococcus aureus. A 285 nm UV LED was used in calibrated fashion to expose contaminated connectors. Ports were directly applied to agar plates and flushed with sterile saline, allowing assessment of bacterial survival on the port surface and in simulated usage flow-through fluid. UV applied to needleless central-line connectors was highly lethal at 0·5 cm distance at all tested exposure times. At distances >1·5 cm both simulated flow-through and port surface cultures demonstrated significant bacterial growth following UV exposure. Logarithmic-phase S. aureus subcultures were highly susceptible to UV induction/maintenance dosing. CONCLUSIONS Low-power UV LED doses at fixed time and distance from needleless central-line connector ports reduced cultivable S. aureus from >10(6) CFU to below detectable levels in this laboratory simulation of central-line port contamination. SIGNIFICANCE AND IMPACT OF THE STUDY Low-power UV LEDs may represent a feasible alternative to current best-practice in connector decontamination.
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Affiliation(s)
- M P Hutchens
- Department of Anesthesiology & Perioperative Medicine, Oregon Health & Science University, Portland, OR, USA
| | - S L Drennan
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
| | - E D Cambronne
- Department of Molecular Microbiology & Immunology, Oregon Health & Science University, Portland, OR, USA
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Ryu HY. Large enhancement of light extraction efficiency in AlGaN-based nanorod ultraviolet light-emitting diode structures. Nanoscale Res Lett 2014; 9:58. [PMID: 24495598 PMCID: PMC3917593 DOI: 10.1186/1556-276x-9-58] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 01/24/2014] [Indexed: 05/16/2023]
Abstract
Light extraction efficiency (LEE) of AlGaN-based nanorod deep ultraviolet (UV) light-emitting diodes (LEDs) is numerically investigated using three-dimensional finite-difference time-domain simulations. LEE of deep UV LEDs is limited by strong light absorption in the p-GaN contact layer and total internal reflection. The nanorod structure is found to be quite effective in increasing LEE of deep UV LEDs especially for the transverse magnetic (TM) mode. In the nanorod LED, strong dependence of LEE on structural parameters such as the diameter of a nanorod and the p-GaN thickness is observed, which can be attributed to the formation of resonant modes inside the nanorod structure. Simulation results show that, when the structural parameters of the nanorod LED are optimized, LEE can be higher than 50% and 60% for the transverse electric (TE) and TM modes, respectively. The nanorod structure is expected to be a good candidate for the application to future high-efficiency deep UV LEDs. PACS: 41.20.Jb; 42.72.Bj; 85.60.Jb.
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Affiliation(s)
- Han-Youl Ryu
- Department of Physics, Inha University, Incheon 402-751, Korea.
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