Blue Light Spectrum Research Articles

Evaluating the Association between Artificial Light-at-Night Exposure and Breast and Prostate Cancer Risk in Spain (MCC-Spain Study).

Background:Night shift work, exposure to light at night (ALAN) and circadian disruption may increase the risk of hormone-dependent cancers.Objectives:We evaluated the association of exposure to ALAN during sleeping time with breast and prostate cancer in a population based multicase–control study (MCC-Spain), among subjects who had never worked at night. We evaluated chronotype, a characteristic that may relate to adaptation to light at night.Methods:We enrolled 1,219 breast cancer cases, 1,385 female controls, 623 prostate cancer cases, and 879 male controls from 11 Spanish regions in 2008–2013. Indoor ALAN information was obtained through questionnaires. Outdoor ALAN was analyzed using images from the International Space Station (ISS) available for Barcelona and Madrid for 2012–2013, including data of remotely sensed upward light intensity and blue light spectrum information for each geocoded longest residence of each MCC-Spain subject.Results:Among Barcelona and Madrid participants with information on both indoor and outdoor ALAN, exposure to outdoor ALAN in the blue light spectrum was associated with breast cancer [adjusted odds ratio (OR) for highest vs. lowest tertile, ; 95% CI: 1.00, 2.17] and prostate cancer (; 95% CI: 1.38, 3.03). In contrast, those exposed to the highest versus lowest intensity of outdoor ALAN were more likely to be controls than cases, particularly for prostate cancer. Compared with those who reported sleeping in total darkness, men who slept in “quite illuminated” bedrooms had a higher risk of prostate cancer (; 95% CI: 1.55, 5.04), whereas women had a slightly lower risk of breast cancer (; 95% CI: 0.39, 1.51).Conclusion:Both prostate and breast cancer were associated with high estimated exposure to outdoor ALAN in the blue-enriched light spectrum. https://doi.org/10.1289/EHP1837

Exposure to Artificial Light-at-Night and Breast and Prostate Cancer Risk in Spain (MCC-Spain study)

Background/Aim: Night shift work, exposure to light-at-night and the consequent circadian disruption may increase the risk of hormone-dependent cancers. We evaluated the association of exposure to artificial light at night (ALAN) during sleeping time with breast and prostate cancer in a population based multicase-control study (MCC-Spain), among subjects who had never worked at night. We took into account chronotype, a characteristic that may relate to adaptation to light-at-night. Methods: We enrolled 1219 breast cancer cases, 1385 female controls, 623 prostate cancer cases and 879 male controls from 11 Spanish regions, 2008-2013. Indoor-ALAN information was obtained through questionnaires and outdoor-ALAN was analyzed using images from the International Space Station (ISS) available for Barcelona and Madrid, including data of remotely sensed upward light intensity and blue light spectrum information for each geocoded longest residence of each MCC-Spain subject. Results: Among participants with information on both indoor and outdoor ALAN, exposure to higher levels of blue light spectrum (outdoor-ALAN) was associated with an increased risk of breast (adjusted odds ratio OR=1.54, 95%CI 1.0-2.4) and prostate cancer (OR=1.90, 95%CI 1.2-2.9). Overall light intensity (outdoor-ALAN) was not associated with cancer risk. Those sleeping in more illuminated bedrooms (indoor-ALAN) had a higher risk of prostate cancer [OR=2.82, 95%CI 1.5-5.3] while there was no clear association for breast cancer (OR=1.19, 95%CI 0.6-2.6). Evening types tended to have slightly higher prostate cancer risks. Conclusions: Both indoor and outdoor ALAN and particularly blue enriched light spectrum were associated with an increased risk of breast and prostate cancer.

Abstract 13: The Effect of Circadian Light on Depressive Mood in Post Stroke Patient During Admission for Rehabilitation

Introduction: Stroke is a major cause of acquired cerebral disability among adults, frequently accompanied by depression. New ways of intervention to prevent post stroke depression is therefore needed. The blue light spectrum is the strongest zeitgeber (time-giver) and is known to stabilize the circadian rhythm. Patients admitted for rehabilitation are often lacking the blue light in daytime due to the long indoor admission; furthermore, they are often exposed to blue light in the evenings, as blue light is contained in standard lightning. Hypothesis: Circadian light will reduce depressive mood in stroke patients admitted for rehabilitation. Methods: The study is a prospective parallel longitudinal randomized controlled study (quasi randomization). Stroke patients in need of rehabilitation were included at the acute stroke unit and randomized to either the intervention unit (IU)(circadian lighting) or the control unit (CU)(standard lighting). The circadian light was installed in the entire IU (Cromaviso, Denmark). Examination was done in the acute unit and at discharge after at least 2 weeks in the IU/CU. Change in depressive mood was measured by the Hamilton Rating Scale for Depression (HAM-D 6 ) and The Major Depression Inventory scale (MDI). Results: Patients were included over a year (N=90), 6 did not reach randomization, 45 were randomized to the IU, and 39 to the CU. A sample of 59 and 62 patients were able to answer the HAM-D 6 (N=30IU;N=29CU) and MDI (N=30IU;N=29CU) score, respectively. Both scores were significantly lower in the intervention group at discharged compared with the control group (ANCOVA, antidepressants medicine was included as a confounder, HAM-D 6 , P=0.018, Estimate=-2.25;SEM=0.92, MDI, P=0.009, Estimate=-4.72;SEM=1.74). Conclusion: Our findings show for the first time circadian light as a beneficial intervention on depressive mood on long-term hospitalized patients in a real hospital setting. The circadian lightning should be considered as an integrated segment in the environment of rehabilitation units.

Effect of LEDs Light Spectrum on Success of Fragmentation and Growth of Leather Coral <i>Sarcophyton</i> spp.

The increasing demand for soft corals is reflected on the high attention of the scientific community during the last decades, with several studies focus on production techniques and optimization of coral husbandry. However, coral culture success is influenced by the interaction of different factors, such as water movement, temperature, nutrients, heterotrophic feeding and light conditions. Light plays a key role in the growth, reproduction and physiology of corals that host phototrophic symbionts and it has been found that the photoresponse of corals is species-specific. Several studies have already focused on the effects of irradiance on coral and its algal symbionts. Although, only a few works have investigated the role of the spectral quality of light on coral photobiology, physiology and growth. In the present study, we hypothesize that light spectrum can influence the growth performance of Leather Coral Sarcophyton spp.when exposed at identical intensities of photosynthetically active radiation (PAR). To test our hypothesis we evaluated the effect of contrasting light spectra with an identical PAR of 70 ± 10 μmol quantam −2 .s −1 emitted by T8 fluorescent lamps (used as a control treatment) and three different colours of Light Emitting Diode (LED), white, blue and red. It was evaluated survival and growth rates of Sarcophyton spp., an important soft coral in the marine aquarium trade and for the bioprospecting of marine natural compounds. Replicated coral fragments were obtained from two mother colonies and were exposed to the four types of light spectrum for a period of 30 days. At the end of the experiment period, the results showed 100% of survival in coral fragments, and specific growth rate (SGR) of 0,055 ± 0,09%/day in control group and 0,091 ± 0,019 %/day, 0,210 ± 0,031%/day and 0,380 ± 0,245%/day in, white, blue and red light, respectively. Moreover, in all treatments at end of experiment the zooxanthellae density was ±, ± and ± for white, blue and red light spectrum, respectively showing that all light promotes conditions for zooxanthellae growth. The results also showed a positive role of use a specific light spectrum in coral growth, namely blue and red spectrum. The use of light with specific light spectrum that increasing the growth and health of corals will minimizing the production costs, increasing the feasibility of ex situ production of ornamental corals and this study identify the best LED`s light spectrum for the growth of the leather coral Sarcophyton spp.

The Influence of Internal Coloured Surfaces on the Circadian Efficiency of Indoor Daylight

The discovery of circadian stimulation by daylight has changed our understanding of the important effect the daylight has on our health and wellbeing. The new medical facts that emerged during the last decade have proven that a long-term absence of circadian light stimulation may be associated with sleep disturbance, tiredness and increased incidence of chronic depression, bipolar disorder, and seasonal affective disorder. The reason is the difference between the visual and biological (circadian) response to light and how it is being perceived by human beings: while the visual perception represented by the luminous efficiency function peaks at the wavelength of 555 nm, the circadian photoreception curve peaks in the blue light spectrum at ~450 nm. The primary circadian stimulation by daylight depends on the properties of light impinging on the retina. An experimental study was designed to quantify the effect of internal coloured surfaces on our circadian stimulation by daylight. Four identical models of a standard office were manufactured, equipped by wallpapers of different colours, and exposed to daylight. Illuminance and spectral distribution of light were measured at different positions along the room and the potential circadian stimulation was evaluated by an established model. The measurements have proven that although the visual comfort may be satisfactory, circadian stimulation may be inhibited, especially when room´s surfaces are yellow. Thus, proper choice of internal surfaces´ colours is important to prevent the potential negative health consequences.

Optical absorption and photoluminescence studies of Dy3+ doped alkaline earth bismuth borate glasses

Dy3+ doped alkaline earth bismuth borate glasses were prepared by the conventional melt-quenching method. The prepared glasses were characterized by absorption, excitation, emission and decay curves. Judd–Ofelt parameters were obtained from the absorption spectra recorded at 400–2000nm. All the samples were excited at different wavelengths from UV (350 nm) to blue (450--470 nm) light and respective emission spectra are recorded. The intensity ratio of yellow to blue (Y/B) indicates that Dy3+ ions are present in low symmetry site. B2O3–Bi2O3RO (R = Ba, Sr & Ca) glasses emit efficient white light under different excitation wavelengths, which match well with the emission of commercial GaN-based blue LEDs and InGaN-based LEDs respectively. CIE coordinates were calculated from the emission spectra and found that they fall in white light region. Decay curves show single exponential nature up to 1mol% of Dy3+ concentrations and then turn into non-exponential for 2mol% of Dy3+ ions. Lifetime of these glasses decreases with increase of Dy3+ ion concentration.

The Protective Effect of Anti‐blue Lens Against Photo‐induced Cell Death

PurposeAnti‐blue lenses that selectively block the harmful portion of the blue light spectrum become commercially available recently. This study aimed to evaluate the protective effect of anti‐blue lens on cultured porcine primary retinal pigmented epithelial (RPE) cells against photo‐irradiation.MethodsPrimary RPE cells were isolated from porcine eyes and cultured to confluence. The cells were characterised by RPE65 using Western Blot. White and blue light emitting diode (LED) light sources as well as the transmittance of the anti‐blue and anti‐UV lenses were characterised by a spectroradiometer. The RPE cells were exposed to ~1.8 × 104 cd/m2 white (peak wavelength at 443 and 533 nm) or blue (peak wavelength at 448 and 523 nm) LED light for 16 hours, with anti‐blue, anti‐UV lens or without lens. Control cells were incubated in the dark. Cellular viability under the different lighting conditions with the anti‐blue or anti‐UV lenses were compared using trypan blue staining and MTT assay.ResultsTrypan blue staining showed that the RPE cellular viability under no light, white light and blue light conditions without any lenses were 94.8 ± 0.4%, 93.7 ± 1.1% and 88.7 ± 2.0% respectively. Blue light irradiation significantly induced more cell death when compared to no light (p = 0.001) and white light (p = 0.005) conditions. MTT assay also revealed significant difference under blue light when compared to no light (p = 0.002) and white light (p = 0.014) conditions. When comparing the effect of anti‐blue and anti‐UV lenses on cell survival, we found that anti‐blue lens showed significantly elevated viability (93.4 ± 1.4% vs 90.6 ± 1.4%) using trypan blue (p = 0.022) and MTT assay (p = 0.029).ConclusionsBlue light exposure induced significant cytotoxicity on RPE cells. The anti‐blue lens significantly reduced the harmful blue spectrum and showed protective effect on RPE cell survival.

The protective effect of anti‐blue lens against photo‐induced cell death

PurposeAnti‐blue lenses that selectively block the harmful portion of the blue light spectrum become commercially available recently. This study aimed to evaluate the protective effect of anti‐blue lens on cultured porcine primary retinal pigmented epithelial (RPE) cells against photo‐irradiation.MethodsPrimary RPE cells were isolated from porcine eyes and cultured to confluence. The cells were characterised by RPE65 using Western Blot. White and blue light emitting diode (LED) light sources as well as the transmittance of the anti‐blue and anti‐UV lenses were characterised by a spectroradiometer. The RPE cells were exposed to ~1.8 × 104 cd/m2 white (peak wavelength at 443 and 533 nm) or blue (peak wavelength at 448 and 523 nm) LED light for 16 hours, with anti‐blue, anti‐UV lens or without lens. Control cells were incubated in the dark. Cellular viability under the different lighting conditions with the anti‐blue or anti‐UV lenses were compared using trypan blue staining and MTT assay.ResultsTrypan blue staining showed that the RPE cellular viability under no light, white light and blue light conditions without any lenses were 94.8 ± 0.4%, 93.7 ± 1.1% and 88.7 ± 2.0% respectively. Blue light irradiation significantly induced more cell death when compared to no light (p = 0.001) and white light (p = 0.005) conditions. MTT assay also revealed significant difference under blue light when compared to no light (p = 0.002) and white light (p = 0.014) conditions. When comparing the effect of anti‐blue and anti‐UV lenses on cell survival, we found that anti‐blue lens showed significantly elevated viability (93.4 ± 1.4% vs 90.6 ± 1.4%) using trypan blue (p = 0.022) and MTT assay (p = 0.029).ConclusionsBlue light exposure induced significant cytotoxicity on RPE cells. The anti‐blue lens significantly reduced the harmful blue spectrum and showed protective effect on RPE cell survival.

EFFECT OF RED LIGHT-BLUE AND NITROGEN STARVATION ON GROWTH OF MICROALGAE Tetraselmis sp.

<p>Microalgae has many benefits for human being. Microalgae is potential source for biodiesel and bioethanol, but the biomass produced from the culture is relatively low. So that, the research has to be done to improve the productivity of the microalgae. Red light and blue light spectrum are known as effective spectrums for the photosynthesis process. Then nitrogen starvation medium is usually performed in order to improve the lipid content. However, nitrogen starvation treatment will decrease microalgae biomass. Therefore, this research aims to study the effect of red and blue light and nitrogen starvation on the growth of Tetraselmis sp. The parameters measured were the cells number, dry weight and chlorophyll a and b. In this study, microalgae Tetraselmis sp. was treated using red and blue light for 7 days. Then, followed by nitrogen starvation treatment with concentration 100%, 50%, and 0% of the f/2 normal medium until day 14. The number of the cells was counted every day for 14 days using a haemocytometer and dry weights were counted at day 0, 1, 5, 7 and 14. Chlorophyll contents were calculated by Jeffrey and Humphrey’s Trichromatic Equations method at absorbance 664 nm, 647 nm, 630 nm, and 750 nm. The results indicated that the red light increased the number of cells to twice as normal, while the blue light increased the number of cells to 1,5 times as normal. Furthermore, the 50% of nitrogen treatment under the red and blue light increased the dry weight to 25% and 60%. </p><p><strong>Keywords</strong>: Microalgae, Tetraselmis sp., Nitrogen Starvation, Blue and Red light</p>

Transparent Mg–α/β-Sialon:Eu2+ ceramics as a yellow phosphor for pc-WLED

Thin transparent yellow phosphor Sialon ceramics were fabricated by hot pressed sintering method. The fabricated Sialon ceramics were co-doped with Eu2O3 and its yellow luminescence was observed around 570nm wavelength when excited by UV to blue light spectrum. Furthermore, the white light was observed when thin yellow phosphor Sialon plates were coupled with blue led (455nm). From XRD patterns, major α-Sialon phase and a minor β-Sialon phase were observed with the addition of Eu2O3. The microstructure revealed that the average grain size was below 500nm and other phases like AlN polytypoids exists as minor phase. Small amount of Y2O3 addition significantly increased the luminescence intensity as compared to only Eu2O3 addition. Sialon ceramics are generally known as advanced ceramics for high temperature applications; the fabricated transparent yellow Sialon phosphor also exhibits good mechanical properties and suitable for remote phosphor.

Light extraction improvement of blue light-emitting diodes with a Metal-distributed Bragg reflector current blocking layer

The p-electrode of blue light-emitting diodes (LED) chips has a low transmittance on the blue light spectrum. The blue light emitted from the quantum wells under the p-electrode will be severely absorbed by p-electrode, which cause a decrease in blue light extraction efficiency (LEE). In this study, we first designed a current blocking layer (CBL) structure with the blue light reflection through the simulation software. The simulation results show that this structure can effectively improve blue LEE, and then, this structure was verified by experiment. Electroluminescence measurement results show that LED with Metal-distributed Bragg reflector (M-DBR) CBL exhibited better optical performance than the LED with SiO2 CBL and DBR CBL. It was found that M-DBR CBL can effectively increase the blue light reflectivity and prevent the light absorption from the metal p-electrode to improve LED’ blue LEE.

Precise Simulation of Spectrum for Green Emitting Phosphors Pumped by a Blue LED Die

This paper proposes an effective approach for spectrum shaping in the optical modeling of phosphor-converted white light-emitting diodes (LEDs) in which overlapping of the absorption and emission spectra of the phosphor are considered. The spectrum shaping method was applied to explore the wavelength-dependent absorption effect and reabsorption by the green phosphor. The experimental results indicated that the adjustment factor for blue light can enable the blue light spectrum to fit well with the measured spectrum. The adjustment factor was linearly related to the transmission ratio of the blue light. The blue light emitted by the blue die and the green light emitted by the phosphor were simulated and predicted in an accurate way as compared with the experimental measurements. The enhanced accuracy in assessing the spectra resulted in enhanced precision of chromaticities. In the experiments, the color differences were one order smaller in CIE 1931 chromaticity (Δx, Δy) than in models without spectrum shaping and were almost imperceptible to the human eye. The novel optical modeling of green phosphor pumped by a blue die facilitates the application of these materials in high-color rendering in white LEDs and projection displays.

The effect of visible blue light on the differentiation of dendritic cells in vitro

Visible blue light (BL) spectrum ranges from 400 nm to 475 nm, peaking at 420 nm. Various biological effects have been shown to be exerted by visible light (VIS) (wavelengths (λ): 400-700 nm), including erythema, pigmentation and generation of reactive oxygen species. Due to the sequential position along the electromagnetic radiation (EMR) spectrum, BL biological effects could be theoretically compared to the UVA ones (λ: 320-400 nm). In the present study we investigated the effects of BL on differentiation, maturation and cytokine production of monocytes derived dendritic cells (MDDCs), through the irradiation of their precursors. MDDC precursors (CD14(+)cells) were isolated from the blood of healthy donors and subsequently irradiated with increasing doses of BL. Differentiation as well as maturation process was assessed by flow cytometry, analyzing CD1a, CD83 and CD86 positive cells. Moreover, intracytoplasmatic immunofluorescence, in irradiated vs unirradiated derived cells, was performed to evaluate IL-6 and TNF-α production. Our findings have shown that BL treatment of MDDCp: i) did not affect the generation of iDCs, ii) did not interfere with terminal differentiation of MDDCs (from iDCs to mDCs) and iii) decreased IL-6 and TNF-α production by MDDCs in a dose-dependent manner. We concluded that BL is unable to interfere with MDDC differentiation and maturation, whereas it is effective in reducing the production of IL-6 and TNF-α.

Blue light toxic action spectrum on A2E‐loaded RPE cells in sunlight normalized conditions

AbstractPurpose Sunlight exposure is supposed to induce cumulative damage to the retina in retinal pathologies, such as AMD. The high energy visible spectrum between 380 nm and 500 nm (blue light) is incriminated. The goal of this study was to identify the spectrum of retinal toxicity induced by sunlight in physiological irradiance conditions.Methods RPE cells incubated for 6 hours with 0, 12.5, 20 and 40 µM of A2E were exposed for 18 hours to 10 nm illumination bands with the first band centered at 390 nm and going up to 520 nm. Light irradiances were normalized with respect to the natural sunlight reaching the retina after filtering by the eye ocular media. Six hours after light exposure, cell viability, necrosis and caspase‐3/7 activity were assessed using the Apotox‐Glo Triplex Assay.Results A2E‐loaded RPE cells presented fluorescent bodies within the cytoplasm with a similar spectrum to that of A2E. Exposure to the 10 nm illumination bands induced morphological changes associated to a loss in cell viability. Light toxicity was dependant of A2E concentration and was higher in the blue spectral range with maxima in a specific 30 to 40 nm bandwidth. In addition, caspase‐3/7 activity, indicative of cell apoptosis, was highly induced by the same narrow range whereas necrosis was not significantly different to that of cells maintained in darkness.Conclusion We described for the first time the precise spectrum of light toxicity in physiological irradiance conditions on an in vitro model of AMD. The 415‐455 nm narrow spectral range generated the greatest phototoxic risk to RPE cells. This provides new information for designing selective protective filters, without disrupting visual and non‐visual functions.

Comparative performance of light emitting plasma (LEP) and light emitting diode (LED) in ex situ aquaculture of scleractinian corals

Ex situ aquaculture of scleractinian corals is considered as a sustainable solution to fulfill the growing demand of these highly priced organisms by the marine aquarium industry. The economic feasibility of ex situ coral aquaculture is strongly dependent on the trade-offs achieved between coral production and energy costs, namely those directly resulting from the need to employ artificial lighting systems. In the present study, we hypothesize that light spectrum can influence the growth performance of cultured scleractinian corals when these are exposed to identical photosynthetically active radiation (PAR) intensities. To test our hypothesis we evaluated the effect of contrasting light spectra delivering an identical PAR of 250±10μmol quanta m−2s−1emitted by T5 fluorescent lamps (used as a control treatment), Light Emitting Plasma (LEP) and Light Emitting Diode (LED) on the photobiology, growth, and protein concentration of two commercially important scleractinian corals: Acropora formosa and Stylophora pistillata. Replicated coral fragments of both species were exposed to the three types of illumination for a period of 5months after which the following features were determined: maximum quantum yield of PSII (Fv/Fm) (monitored non-intrusively through Pulse Amplitude Modulation fluorometry, PAM), chlorophyll a content (also determined non-destructively by using the spectral reflectance index Normalized Difference Vegetation Index, NDVI), growth and protein content. Coral fragments of both species cultured under LEP lighting, presented significantly higher values of Fv/Fm when compared intraspecifically with coral fragments cultured with T5 or LED lighting. Fragments of S. pistillata cultured under LEP illumination presented significantly higher NDVI values than fragments grown with T5 or LED. No significant differences were found on the protein concentration of A. formosa under different light treatments, while fragments of S. pistillata grown with LED illumination presented a significantly higher concentration of protein than those cultured with T5 or LEP illumination. Both LED and LEP technologies have shown to be interesting alternatives to provide artificial lighting for coral aquaculture ex situ, with the blue light spectrum of LED promoting high growth performances for both coral species and a lower energetic cost per m2 of production area (0.71€m−2day−1 for T5, 0.38€m−2day−1 for LEP, and 0.28€m−2day−1 for LED).

Atividade da catalase e da lactato desidrogenase em tilápias submetidas a estresse de confinamento: efeito da cor do ambiente

Avaliaram-se os efeitos da cor do ambiente sobre o crescimento e a atividade da enzima antioxidante catalase (CAT) e da lactato desidrogenase (LDH) em tilápias do Nilo (n=24; 36,2±3,6g). Oito exemplares foram mortos para determinação da atividade basal das enzimas e os demais permaneceram isolados durante 14 dias sob espectro de luz branca ou azul (n=8 peixes/tratamento). A seguir os peixes foram submetidos a um estresse diário de confinamento de 90 minutos (15° ao 28° dia) e pesados semanalmente para cálculo da taxa de crescimento específico (TCE). A TCE negativa confirmou que o confinamento provocou estresse nos peixes, independentemente da cor do ambiente. O aumento da atividade da LDH no músculo vermelho dos peixes mantidos sob luz branca ou azul indicou mudança do metabolismo aeróbio para anaeróbio. O estresse reduziu a atividade da CAT no músculo branco dos peixes mantidos sob a luz branca ou azul. Na musculatura vermelha, esta redução ocorreu apenas nos animais mantidos sob a luz branca. O confinamento aumenta os processos metabólicos anaeróbios e é adequado para estudos sobre os efeitos do estresse. O espectro de luz azul não evita a redução do crescimento e a demanda energética anaeróbia em situações de estresse, mas preserva a atividade da CAT, contribuindo para o bem-estar da tilápia.

Breast Cancer Therapy Based on Melatonin

The usefulness of melatonin and melatoninergic drugs in breast cancer therapy is based on its Selective Estrogen Receptor Modulator (SERM) and Selective Estrogen Enzyme Modulator (SEEM) properties. Because of the oncostatic properties of melatonin, its nocturnal suppression by light-at-night (LAN) has been considered a risk-factor for breast cancer. Melatonin's SERM actions include modulation of estrogen-regulated cell proliferation, invasiveness and expression of proteins, growth factors and proto-oncogenes (hTERT, p53, p21, TGFβ, E-cadherin, etc.). These actions are observable with physiologic doses of melatonin only in cells expressing ERα, and mediated by MT1 melatonin receptors. Melatonin acts like a SEEM, inhibiting expression and activity of P450 aromatase, estrogen sulfatase and type 1, 17β- hydroxysteroid dehydrogenase, but stimulating that of estrogen sulfotransferase. This double action mechanism (SERM and SEEM), and the specificity for ERα bestows melatonin with potential advantages for breast cancer treatments, associated with other antiestrogenic drugs, and idea already patented. LAN enhances the growth of rat mammary tumors by decreasing or suppressing melatonin production. Epidemiologic studies have also described increased breast cancer risk in women exposed to LAN. Since the strongest suppression of nocturnal melatonin occurs with wavelength light of the blue spectral region, optical and lightening devices filtering the blue light spectrum have been proposed to avoid the risks of light-induced suppression of nocturnal melatonin.

Comparison of Blue Light-Filtering IOLs and UV Light-Filtering IOLs for Cataract Surgery: A Meta-Analysis

BackgroundA number of published randomized controlled trials have been conducted to evaluate visual performance of blue light-filtering intraocular lenses (IOL) and UV light-filtering intraocular lenses (IOL) after cataract phacoemulsification surgery. However, results have not always been consistent. Therefore, we carried out a meta-analysis to compare the effectiveness of blue light-filtering IOLs versus UV light-filtering IOLs in cataract surgery.Methods and FindingsComprehensive searches of PubMed, Embase, Cochrane Library and the Chinese BioMedical literature databases were performed using web-based search engines. Fifteen trials (1690 eyes) were included for systematic review, and 11 of 15 studies were included in this meta-analysis. The results showed that there were no significant differences in postoperative mean best corrected visual acuity, contrast sensitivity, overall color vision, or in the blue light spectrum under photopic light conditions between blue light-filtering IOLs and UV light-filtering IOLs [WMD = −0.01, 95%CI (−0.03, 0.01), P = 0.46; WMD = 0.07, 95%CI (−0.04, 0.19), P = 0.20; SMD = 0.14, 95%CI (−0.33, 0.60), P = 0.566; SMD = 0.20, 95%CI (−0.04, 0.43), P = 0.099]. However, color vision with blue light-filtering IOLs was significantly reduced in the blue light spectrum under mesopic light conditions [SMD = 0.74, 95%CI (0.29, 1.18), P = 0.001].ConclusionThis meta-analysis demonstrates that postoperative visual performance with blue light-filtering IOLs is approximately equal to that of UV light-filtering IOLs after cataract surgery, but color vision with blue light-filtering IOLs demonstrated some compromise in the blue light spectrum under mesopic light conditions.

Comparison of visual performance with blue light–filtering and ultraviolet light–filtering intraocular lenses

To compare the contrast sensitivity, glare, color perception, and visual acuity at different light intensities with yellow-tinted and clear intraocular lenses (IOLs) by different manufacturers. Ludwig Boltzmann Institute of Retinology and Biomicroscopic Laser-Surgery, Department of Ophthalmology, Rudolf Foundation Clinic, Vienna, Austria. Comparative case series. Eyes were randomized to 1 of the following IOLs: AF-1 (UY) (yellow tinted), AcrySof SN60AT (yellow tinted), AF-1 (UV) (clear), or AcrySof SA60AT (clear). One week and 2 months postoperatively, monocular contrast sensitivity function and color discrimination were tested and the corrected distance and near visual acuities were evaluated. All tests were performed under different light intensities (10 to 1000 lux). Of the 80 patients enrolled, 76 completed the study; there were 37 eyes in the yellow-tinted IOL group and 39 in the clear IOL group. There were no significant differences between yellow-tinted IOLs and clear IOLs except in color vision under mesopic conditions (10 lux). Patients with a yellow-tinted IOL made significantly more mistakes in the blue-light spectrum than patients with clear IOLs (P = .00015). There was no significant difference under photopic conditions (1000 lux). The yellow-tinted IOLs were equivalent to the clear IOLs in postoperative contrast sensitivity, visual acuity, and color perception under photopic conditions. Patients with yellow-tinted IOLs made statistically significantly more mistakes in the blue range under dim light than patients with clear IOLs.

A novel method for imaging internal growth patterns in marine mollusks: A fluorescence case study on the aragonitic shell of the marine bivalve Arctica islandica (Linnaeus)

In this article, we explore the use of fluorescence spectroscopy to image growth patterns in the marine bivalve Arctica islandica (L.). The method presented here does not require any chemical treatment of the polished shell section and yields results comparable to acetate peels of acid‐etched shell sections and Mutveitreated shell sections. Further, our results indicate that the annual growth lines in A. islandica fluoresce in the blue light spectrum (450–490 nm), thus an ultraviolet source (mercury lamp) is not required. The reflected light entering the digital camera was filtered (510–540 nm) and later enhanced to emphasize the annual growth patterns. The fluorescence of annual growth lines was consistent among the four animals used in this study. Additionally, we measured growth increments in the umbo section of one A. islandica shell using both the traditional acetate method and fluorescence imaging. The two sets of measurements were highly correlated (r = 0.97; P < 0.0001). We suggest that the fluorescence imaging method presented here is a viable option for increment identification and measurement in this key marine archive. It is likely that the methods demonstrated here for A. islandica can easily be used/modified for other bivalve (mollusk) taxa. Fluorescence microscopy permits rapid analysis of shell growth patterns with minimal pretreatment and offers an objective method of determination of annual growth increments and lines.