Red LED Light Research Articles

Daylight photodynamic therapy in Scotland.

Chronic sun-induced dysplastic skin changes (actinic keratoses) are extremely common in fair-skinned people in Scotland. These changes are a major cause of morbidity and may develop into skin cancer. Actinic keratoses are often extensive and pose a therapeutic challenge as field-directed treatment is required for chronic disease management. One such treatment approach is hospital-based photodynamic therapy, which is a well-established treatment in Scotland for actinic keratoses, using a photosensitiser pro-drug and red LED light irradiation. However, photodynamic therapy using daylight as the activating light source is increasingly and effectively used in continental Europe, but had not been explored in Scotland until we initiated this in 2013. We report our experience of daylight photodynamic therapy in 64 patient-treatment courses and demonstrate that this can be an effective, well-tolerated treatment, which is liked by patients. Our most recent data show that most patients (73%) achieved clearance or at least a good response to treatment and had high levels of satisfaction with daylight photodynamic therapy. Daylight exposure measurements indicated that treatment is feasible in Scotland between April to September. Daylight photodynamic therapy is an important advancement in treatment options for Scottish patients with extensive pre-cancerous field changes and provides opportunities for home-based treatment and increased efficiency of photodynamic therapy services.

Simultaneity judgment using olfactory-visual, visual-gustatory, and olfactory-gustatory combinations.

Vision is a physical sense, whereas olfaction and gustation are chemical senses. Active sensing might function in vision, olfaction, and gustation, whereas passive sensing might function in vision and olfaction but not gustation. To investigate whether each sensory property affected synchrony perception, participants in this study performed simultaneity judgment (SJ) for three cross-modal combinations using visual (red LED light), olfactory (coumarin), and gustatory (NaCl solution) stimuli. We calculated the half-width at half-height (HWHH) and point of subjective simultaneity (PSS) on the basis of temporal distributions of simultaneous response rates in each combination. Although HWHH did not differ significantly among three cross-modal combinations, HWHH exhibited a higher value in cross-modal combinations involving one or two chemical stimuli than in combinations of two physical stimuli, reported in a previous study. The PSS of the olfactory–visual combination was approximately equal to the point of objective simultaneity (POS), whereas the PSS of visual–gustatory, and olfactory–gustatory combinations receded significantly from the POS. In order to generalize these results as specific to chemical senses in regard to synchrony perception, we need to determine whether the same phenomena will be reproduced when performing SJ for various cross-modal combinations using visual, olfactory, and gustatory stimuli other than red LED light, coumarin, and NaCl solution.

Regulation of Organogenesis via PGRs and LEDs light technology for Jatropha curcas L. Plants

Because of the increased interest in the potential of Jatropha as a biofuel plant, more attention is given to methods that allow the mass production of elite material. A simple and efficient protocol has been developed for high frequency regeneration using nodal explants of Madagascar and Ecuador Jatropha curcas lines. The optimum shoot growth with high number and without callus formation was observed using MS medium supplemented with 1.0 mg/l BA in both lines within a period of 30-40 days which shows 3.8 and 3.4 shoot buds in Madagascar and Ecuador lines, respectively. Healthy elongated shoots were harvested and cultured on ½ strength MS basal salts without vitamins medium containing different concentrations of IBA individual or in combination with IAA or 2,4-D. Moreover, the optimum rooting medium with good root formation (46.6 and 40%) in both Jatropha lines and (3.0 – 2.4) roots per shoot containing half-strength MS supplemented with 0.5 mg/l IBA. In the present study, different light sources like cool white fluorescent, warm white fluorescent and different high- brightness LEDs (red – blue – white) were used to monitor the root initiation of in vitro Jatropha shoots. Red LED light provided the most favorable growth conditions inducing a rooting response in 66.6% of the shoots in Madagascar Jatropha and 56.5% in Ecuador Jatropha which produced on average 4.2 and 3.5 roots per shoot, respectively in both lines. Thus, white LED light was more effective on root elongation than all studied light treatments that recorded (5.6 and 4.4 cm) root length in both lines. Therefore, well developed healthy in vitro rooted plantlets after 6 weeks were successfully acclimatized and the survival rate of in vitro propagated plantlets after transplanting was 40-60% and they grew as normal plants in the greenhouse.

Methylene blue, curcumin and ion pairing nanoparticles effects on photodynamic therapy of MDA-MB-231 breast cancer cell

PurposeThe aim of current study was to use methylene blue-curcumin ion pair nanoparticles and single dyes as photosensitizer for comparison of photodynamic therapy (PDT) efficacy on MDA-MB-231 cancer cells, also various light sources effect on activation of photosensitizer (PS) was considered. MethodIon pair nanoparticles were synthesized using opposite charge ions precipitation and lyophilized. The PDT experiments were designed and the effect of PSs and light sources (Red LED (630nm; power density: 30mWcm−2) and blue LED (465nm; power density: 34mWcm−2)) on the human breast cancer cell line were examined. The effect of PS concentration (0–75μg.mL−1), incubation time, irradiation time and light sources, and priority in irradiation of blue or red lights were determined. ResultsThe results show that the ion pairing of methylene blue and curcumin enhance the photodynamic activity of both dyes and the cytotoxicity of ion pair nanoparticles on the MDA-231 breast cancer cell line. Blue and red LED light sources were used for photo activation of photosensitizers. The results demonstrated that both dyes can activate using red light LED better than blue light LED for singlet oxygen producing. ConclusionNano scale ion pair precipitating of methylene blue-curcumin enhanced the cell penetrating and subsequently cytotoxicity of both dyes together.

While continuous white LED lighting increases chlorophyll content (SPAD), green LED light reduces the infection rate of lettuce during storage and shelf-life conditions

The aim of this study is to prevent postharvest quality losses and enhance storage and shelf life of leaf lettuce using LED light treatments. For this purpose, four different colors of (white, green, red, and blue) LED light and darkness conditions were used. Lettuce was stored at a temperature of 5 °C ± 1 °C for 21 days, and after storage, it was kept at room temperature for 96 hr. This study demonstrated that white LED light showed up the best application in terms of maintaining green color, reducing chlorophyll degradation, and increasing the total soluble solid content of lettuce. While the weight loss was reduced by red LED light treatment, the green LED light was effective in reducing the decay rate of lettuce. It was concluded that white, red and green LED lighting treatments are useful for enhancing the storage life of leaf lettuce, whereas the blue LED light treatment showed negative effects. Practical applications Light-emitting diodes (LEDs) is used in horticultural production to increase yield by photosynthesis over decades. In postharvest storage stage, lighting of LED provided some advantages such as reducing of the growth of microorganism, especially citrus varieties. Leafy vegetables are identified susceptible because it contains large amount of water. Also they lose their green color very quickly after harvest. So, postharvest storage life of these type vegetable is quite short. As a result of the present study, chlorophyll (SPAD) content of leaf lettuce was increased by white LED light treatment both during storage and shelf life conditions. Therefore, by this technology, the shelf life of leaf lettuce would be increased by lighting of shelf in the supermarket by white LED, at least.

Effects of blue and red LED lights on soilless cultivated strawberry growth performances and fruit quality

Effects of blue and red LED lights on soilless cultivated strawberry growth performances and fruit quality

Effect of Spectral Quality of Monochromatic LED Lights on the Growth of Artichoke Seedlings.

Indoor farming is becoming a popular alternative approach in food production to meet the demand of a growing world population. Under this production system, artificial light provides the main source of illumination in sustaining plant growth and development. The use of light-emitting diodes (LEDs) is a popular source of artificial light for indoor farms due to its narrow light spectra, modular design and energy efficiency. This study purposely assessed the effect of monochromatic LED light quality on the growth of three varieties of artichoke seedlings compared to greenhouse condition. Spectral quality assessment showed that photosynthetic photon flux density (PPFD) was highest under red LED light, but only a third of the total PPFD under natural light. Seedlings grown under red light showed 60–100% more shoot dry weight and were 67–115% taller than seedlings grown in the greenhouse. However, seedlings under blue or white light conditions showed 67–76% less in biomass compared to greenhouse-grown seedlings. Overall, plant response of seedlings under red light condition was much better compared to greenhouse-grown seedlings emphasizing the importance of red light spectral quality in plant growth and development.

Effect of Methyl Aminolevulinate Photodynamic Therapy With and Without Ablative Fractional Laser Treatment in Patients With Microinvasive Squamous Cell Carcinoma

Surgical excision is the standard treatment for cutaneous squamous cell carcinoma (SCC). However, microinvasive SCC (Clark level II) is limited to the papillary dermis, and it should be differentiated from invasive SCC. Ablative fractional laser-primed photodynamic therapy (AFL-PDT) may have enhanced efficacy. To compare 1 session of AFL-PDT with 2 sessions of conventional methyl aminolevulinate-PDT (MAL-PDT) for the treatment of microinvasive SCC. A 2-armed, randomized, single-blind, comparative trial of 45 patients with histologically proven microinvasive SCC. Twenty-one patients were randomized to treatment with a single AFL-PDT session, and 24 patients were randomized to 2 MAL-PDT sessions with a 1-week interval between sessions using a computer-generated program. Standard pretreatment such as curettage was not performed prior to PDT owing to a tendency to bleed. The efficacy, recurrence rate, cosmetic outcomes, and safety were assessed 1 week, 3, 12, and 24 months after the last treatment. AFL was performed with an ablation depth of 550 µm to 600 µm, coagulation level of 1, treatment density of 22%, and a single pulse. Then, MAL cream was applied under occlusion for 3 hours and illuminated by using a red light-emitting diode light at 37 J/cm2. A second session of MAL-PDT was administered after 7 days. The primary outcome measures were the lesion response at 3 and 12 months, and the recurrence rate 12 months after the last treatment. Twenty-one patients (6 men, 15 women) with a mean (SD) age of 76 (6) years were randomized to treatment with a single AFL-PDT session, and 24 patients (11 men, 13 women) with a mean (SD) age of 75 (6) years were randomized to 2 MAL-PDT sessions. The overall complete response rates 3 months after treatment were 84.2% with AFL-PDT and 52.4% with MAL-PDT (P = .03). These differences in efficacy remained significant at the 24-month follow-up. The recurrence rate was significantly lower with AFL-PDT (12.5%) than with MAL-PDT (63.6%) at 24 months (P = .006). AFL-PDT and MAL-PDT did not differ significantly with respect to the cosmetic outcomes, adverse events, or pain intensity. AFL-PDT can be used as an alternative treatment option for patients with microinvasive SCC who are not suitable for surgical treatment. clinicaltrials.gov Identifier: NCT02666534.

Homogeneous photosensitized degradation of pharmaceuticals by using red light LED as light source and methylene blue as photosensitizer

Research on employing advanced oxidation processes (AOPs) for pharmaceuticals removal is gaining interests. However, detrimental effects of background water constituents in complex water matrices are limiting their implementation. In this study, we report red light induced methylene blue photosensitization (MB/Red-light) as a promising alternative for pharmaceuticals removal from wastewater, because of its potential to overcome detrimental effects of background water constituents as experienced in other AOP technologies. In this study, the efficacy of MB/Red-light on degradation of four pharmaceutical compounds, i.e. diclofenac (DFN), metoprolol (MTP), propranolol (PRP) and sulfamethoxazole (SFZ), was investigated. The MB/Red-light photosensitization enabled degradation of three model compounds, i.e. DFN, PRP and SFZ. Degradation rates followed the order of DFN＞PRP＞SFZ. Singlet oxygen was found to be crucial in pharmaceuticals degradation, and another additional mechanism, i.e. a direct reaction with triplet MB, also contributed to DFN degradation. The presence of two DFN degradation mechanisms were confirmed by UV–vis light absorbance spectra measurement as well as the identification of degradation products by LC–MS/MS. Effects of three common back ground water constituents were examined to assess the applicability of MB/red-light system in complex water matrices, which suggests that the MB/red-light system has great potential to be used in real wastewater. Higher pH was found to impose positive impact on the efficacy of the proposed system. Last but not least, red light LED is an optimum light source for the proposed MB/Red-light system, because the light emission spectrum of the LED used in this study fits well with the light absorption spectrum of the photosensitizer-methylene blue.

Erratum to: Contrasting effects of blue and red LED irradiations on the growth of Sargassum horneri during the germling and immature stages

The brown seaweed Sargassum horneri (Sargassaceae) is important for marine environment conservation. It could be used for a food material, medical applications, and future biofuel production. We compared the growth of S. horneri cultures under single wavelength blue and red light during the germling and immature stages. The growth rate based on the thallus area of S. horneri during the germling stage was faster under blue LED light than under red LED light. Furthermore, based on the wet weight of S. horneri, during the immature stage, blue LED light resulted in a faster growth rate than red LED light. Moreover, during the immature stage, compared with red LED light, blue LED light tended to increase the content of photosynthetic pigments. We conclude that use of blue LED light in indoor tanks during the germling and immature stages will improve the efficiency of S. horneri culture.

An RNA-Seq Analysis of Grape Plantlets Grown in vitro Reveals Different Responses to Blue, Green, Red LED Light, and White Fluorescent Light

Using an RNA sequencing (RNA-seq) approach, we analyzed the differentially expressed genes (DEGs) and physiological behaviors of “Manicure Finger” grape plantlets grown in vitro under white, blue, green, and red light. A total of 670, 1601, and 746 DEGs were identified in plants exposed to blue, green, and red light, respectively, compared to the control (white light). By comparing the gene expression patterns with the growth and physiological responses of the grape plantlets, we were able to link the responses of the plants to light of different spectral wavelengths and the expression of particular sets of genes. Exposure to red and green light primarily triggered responses associated with the shade-avoidance syndrome (SAS), such as enhanced elongation of stems, reduced investment in leaf growth, and decreased chlorophyll levels accompanied by the expression of genes encoding histone H3, auxin repressed protein, xyloglucan endotransglycosylase/hydrolase, the ELIP protein, and microtubule proteins. Furthermore, specific light treatments were associated with the expression of a large number of genes, including those involved in the glucan metabolic pathway and the starch and sucrose metabolic pathways; these genes were up/down-regulated in ways that may explain the increase in the starch, sucrose, and total sugar contents in the plants. Moreover, the enhanced root growth and up-regulation of the expression of defense genes accompanied with SAS after exposure to red and green light may be related to the addition of 30 g/L sucrose to the culture medium of plantlets grown in vitro. In contrast, blue light induced the up-regulation of genes related to microtubules, serine carboxypeptidase, chlorophyll synthesis, and sugar degradation and the down-regulation of auxin-repressed protein as well as a large number of resistance-related genes that may promote leaf growth, improve chlorophyll synthesis and chloroplast development, increase the ratio of chlorophyll a (chla)/chlorophyll b (chlb), and decrease the ratio of carbohydrates to proteins in plants. Although exposure to red and green light seems to impose “shade stress” on the plantlets, growth under blue light is comparable to growth observed under white or broad-spectrum light.

Characterization, catalyzed water oxidation and anticancer activities of a NIR BODIPY-Mn polymer

To obtain near-IR absorbing biomaterials as fluorescence cellular imaging and anticancer agents for hypoxic cancer cell, a nano NIR fluorescence Mn(III/IV) polymer (PMnD) was spectroscopically characterized. The PMnD shows strong emission at 661nm when excited with 643nm. Furthermore, PMnD can catalyze water oxidation to generate dioxygen when irradiated by red LED light (10W). In particular, the PMnD can enter into HepG-2 cells and mitochondria. Both anticancer activity and the inhibition of the expression of HIF-1α for PMnD were concentration dependent. Our results demonstrate that PMnD can be developed as mitochondria targeted imaging agents and new inhibitors for HIF-1 in hypoxic cancer cells.

Parameterization of a light distribution model for green cell growth of microalgae: Haematococcus pluvialis cultured under red LED lights

A light distribution model is a prerequisite for establishing an algal growth model. Based on approaches to account for light intensity, algal productivity models can be divided into three types, Type I models predict the rate of photosynthesis, Type II models computes productivity and Type III models considers the impacts of both light gradients and short light cycles. Among these, Type II models may offer the best compromise between accuracy and practicability for full-scale engineering applications. Addressing the need for examining indoor seed preparation of Haematococcus pluvialis under red LED irradiation, this study advanced a Type II model based on light distribution. The model was parameterized for green cell growth of Haematococcus pluvialis using the Gauss-Newton and bootstrap methods. The parameters k1 and k2 from the hyperbolic Beer-Lambert law of the two-flux model were 118.8±5.2m−1 and 0.25±0.04gL−1, with 95% confidence intervals of (111.6, 129.8) and (0.20, 0.33), respectively. The parameterized model was validated against experimental results, with the largest error and relative error of 0.08μmol/m2/s and 10.5%, respectively. Validation results demonstrate that the established model was reliable and could accurately predict the light intensity for indoor cultivation of Haematococcus pluvialis in the green stage. This study demonstrated that the effectiveness of using the bootstrap method to accurately estimate the parameters in these types of models. It provided information on model parameters, including standard deviation and 95% confidence intervals. This model also applied many more data points (89 in this study) to estimate parameters to reduce error. The results filled a technological gap for modeling the light distribution of indoor seed preparation of Haematococcus pluvialis under red LED lights. The approach can be used to estimate the values of parameters from parametric models for other similar applications using the bootstrap method.

Effects of different light quality on growth, photosynthetic characteristic and chloroplast ultrastructure of upland cotton (Gossypium hirsutum L.) seedlings

In this work, we evaluated our results showed that the mixture blue plus red LED light might be propitious to upland cotton seedling growth and can be used as a primary lights for cotton seedling cultivation. This study might be the first paper of determining different light qualities on growth, photosynthetic characteristic and chloroplast ultra-structure of upland cotton cultivar Sumian 22. The mixture blue plus red (BR1:8) LEDs light might be propitious and necessary to upland cotton seedling growth and can be used as a primary lights for cotton seedling cultivation.

赤色光がミカンキイロアザミウマの植物に対する行動に及ぼす影響評価

We used light-emitting diodes (LEDs) to examine the effect of red light on the behavioral responses of melon thrips, Flankliniella occidentalis. We allowed adults to choose between tomato plants exposed and unexposed to red LED light under ambient fluorescent lighting conditions. Thrips were less attracted to plants exposed to red LED light during 8- as well as 24-h exposure.

Produção de mudas de alface, pepino e pimentão em função da qualidade do espectro luminoso

The response of lettuce (Lactuca sativa), cucumber (Cucumis sativus) and sweet pepper (Capsicum annuum) seedlings to light spectral quality when grown under continuous illumination was investigated in relation to the growth, dry matter, and seedling quality index. Different light quality treatments were applied during the germination and plant growth steps, using cool-white fluorescent bulbs (CWF) or red and blue light-emitting diodes (LEDs) at an fluence of 30 and 25 μmol m-2 s-1 photosynthetic photon flux density (PPFD), respectively. Treatments were arranged in a completely randomized design in a 3×2 factorial: three vegetable species (lettuce, cucumber and sweet pepper) and two light quality treatments (white fluorescent light or red and blue LEDs), with four replications. Results showed that the vegetables had distinct growth responses to different light-quality treatments. Number of leaves was significantly greater under blue and red LEDs light compared to the CWF lighting, for the three vegetable species. Shoot length and root collar diameter of lettuce and sweet pepper were significantly greater under blue and red LEDs light compared to the CWF light, while cucumber seedlings showed no significant differences. Root length, root dry matter and Dickson quality index (DQI) of the cucumber seedlings was significantly greater under blue and red LEDs light compared to the CWF light, while lettuce and sweet pepper seedlings showed no significant differences. Shoot dry matter (SDM) and total dry matter (TDM) of the lettuce and cucumber seedlings were greater when grown under blue and red LEDs light. The lighting with blue and red wavelengths from LEDs resulted in better quality cucumber seedlings compared to the cool-white fluorescent light. The shoot growth rate of lettuce seedlings was favored by blue and red LEDs light. Different spectral qualities have little effect on growth and development of sweet pepper seedlings.

Contrasting effects of blue and red LED irradiations on the growth of Sargassum horneri during the germling and immature stages

The brown seaweed Sargassum horneri (Sargassaceae) is important for marine environment conservation. It could be used for a food material, medical applications, and future biofuel production. We compared the growth of S. horneri cultures under single wavelength blue and red light during the germling and immature stages. The growth rate based on the thallus area of S. horneri during the germling stage was faster under blue LED light than under red LED light. Furthermore, based on the wet weight of S. horneri, during the immature stage, blue LED light resulted in a faster growth rate than red LED light. Moreover, during the immature stage, compared with red LED light, blue LED light tended to increase the content of photosynthetic pigments. We conclude that use of blue LED light in indoor tanks during the germling and immature stages will improve the efficiency of S. horneri culture.

Micropropagation of Gerbera (<i>Gerbera jamesonii Bolus</i>) under Different Color of Light-Emitting Diodes

In present research, the effects of light quality on micropropagation of gerbera were investigated. The MS medium containing 1 mg L -1 BAP and 0.1 mg L -1 NAA was used in proliferation stage and the MS medium containing 0.05 mg L -1 IBA was used in rooting stage of the study. Cultured plants were grown in cabinets illuminated with red, blue, daylight LED lamps separately and their various mixtures. Cool white fluorescent lamp was used as control treatment in the study. The highest ratio of explant with new shoots, the number of shoots per explant and shoot length values were obtained from cool white fluorescent lamps (90%, 5.35 shoots and 2.63 cm, respectivey), 100% blue LED lamp (95%, 5.24 shoots and 2.40 cm, respectively), 100% cool white LED lamp (90%, 4.18 shoots and 2.21 cm, respectively) and 70% red + 30% blue LED lamp treatments (80%, 4.14 shoots and 2.21cm, respectively) in the proliferation stage of the study. These treatments also yielded the highest values in terms of plant fresh and dry weight. While the highest rooting percentage (75%) was obtained from 100% cool white LED light treatment, the differences between the treatments except for 100% red LED light were not significant. Rooted plants were successfully acclimatized to outdoor conditions with 84% survival rate in peat + perlite mixture (2:1).

Light-Emitting Diode Spectral Sensitivity Relationship with Growth, Feed Intake, Meat, and Manure Characteristics in Broilers

Abstract. Light-emitting diode (LED) light sources have high potential for replacing traditional incandescent lamps in broiler production. LEDs with short wavelengths (480 and 560 nm) have been reported to stimulate broiler growth. However, short-wavelength stimuli might also have potential negative effects on husbandry workers, which has restricted the application of LED technology to broiler production. In this study, we investigated the effect of human-friendly yellow LED light (580 nm), which is close to the wavelength of 560 nm and acceptable for humans, on broiler growth response. We further evaluated the effects of various LED lights on the feed intake and manure characteristics of broilers. The following seven light treatments were tested: red LED light (R group), yellow LED light (Y group), green LED light (G group), blue LED light (B group), purple LED light (P group), white LED light (W group), and incandescent bulb light (I group). We used a 12:12 light:dark cycle, as described in our previous study. The feed and water usage of each group were recorded daily, while body weight and manure weight were determined weekly. Manure from each group was sampled for subsequent analysis. We found that the effects of the LEDs on broiler growth were age-related. Broilers in the Y, G, and B groups had similar body weights. However, the relative body weight gain ratio of broilers in the Y group was always greater than those of broilers in the other groups, particularly those in the I group (p = 0.003). The mass ratio of water usage to feed consumption was highest in the R group, whereas the Y group had the lowest mass ratio. Analysis of manure characteristics showed that manure production was positively correlated with feed intake, and broilers in the Y group produced the lowest amount of manure. The water intake of the broilers and the moisture content of the manure were also positively correlated, suggesting that the lower moisture content of the Y group manure might be caused by decreased water intake. These findings suggest that human-friendly yellow LED light might be a good alternative to green LED, blue LED, and incandescent lamps and can successfully be applied to broiler production.

Stimulation of Stevioside Accumulation on Stevia rebaudiana (Bertoni) Shoot Culture Induced with Red LED Light in TIS RITA® Bioreactor System

Stimulation of Stevioside Accumulation on Stevia rebaudiana (Bertoni) Shoot Culture Induced with Red LED Light in TIS RITA® Bioreactor System