Influence of blue light spectrum filter on short-wavelength and standard automated perimetries

The spectrum of light significantly influences the growth of plants cultivated in closed systems. Five lettuce cultivars with different leaf colours were grown under white light (W, 170 μmol m−2 s−1) and under white light with the addition of red (W + R) or blue light (W + B) (230 μmol m−2 s−1). The plants were grown until they reached the seedling phase (30 days). Each cultivar reacted differently to the light spectrum applied. The red-leaved cultivar exhibited the strongest plasticity in response to the spectrum. The blue light stimulated the growth of the leaf surface in all the plants. The red light negatively influenced the length of leaves in the cultivars, but it positively affected their number in red and dark-green lettuce. It also increased the relative chlorophyll content and fresh weight gain in the cultivars containing anthocyanins. When the cultivars were grown under white light, they had longer leaves and higher value of the leaf shape index. The light-green cultivars had a greater fresh weight. Both the addition of blue and red light significantly increased the relative chlorophyll content in the dark-green cultivar. The spectrum enhanced with blue light had positive influence on most of the parameters under analysis in butter lettuce cultivars. These cultivars were also characterised by the highest absorbance of blue light.

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Blue as an Underrated Alternative to Green: Photoplethysmographic Heartbeat Intervals Estimation under Two Temperature Conditions

Sensors ◽

10.3390/s21124241 ◽

2021 ◽

Vol 21 (12) ◽

pp. 4241

Author(s):

Evgeniia Shchelkanova ◽

Liia Shchapova ◽

Alexander Shchelkanov ◽

Tomohiro Shibata

Keyword(s):

Blue Light ◽

Characteristic Point ◽

Biological Effects ◽

Green Light ◽

Estimation Accuracy ◽

Lower Sensitivity ◽

Light Spectrum ◽

Cardiovascular Parameter ◽

Temperature Conditions ◽

Characteristic Points

Since photoplethysmography (PPG) sensors are usually placed on open skin areas, temperature interference can be an issue. Currently, green light is the most widely used in the reflectance PPG for its relatively low artifact susceptibility. However, it has been known that hemoglobin absorption peaks at the blue part of the spectrum. Despite this fact, blue light has received little attention in the PPG field. Blue wavelengths are commonly used in phototherapy. Combining blue light-based treatments with simultaneous blue PPG acquisition could be potentially used in patients monitoring and studying the biological effects of light. Previous studies examining the PPG in blue light compared to other wavelengths employed photodetectors with inherently lower sensitivity to blue, thereby biasing the results. The present study assessed the accuracy of heartbeat intervals (HBIs) estimation from blue and green PPG signals, acquired under baseline and cold temperature conditions. Our PPG system is based on TCS3472 Color Sensor with equal sensitivity to both parts of the light spectrum to ensure unbiased comparison. The accuracy of the HBIs estimates, calculated with five characteristic points (PPG systolic peak, maximum of the first PPG derivative, maximum of the second PPG derivative, minimum of the second PPG derivative, and intersecting tangents) on both PPG signal types, was evaluated based on the electrocardiographic values. The statistical analyses demonstrated that in all cases, the HBIs estimation accuracy of blue PPG was nearly equivalent to the G PPG irrespective of the characteristic point and measurement condition. Therefore, blue PPG can be used for cardiovascular parameter acquisition. This paper is an extension of work originally presented at the 42nd Annual International Conference of the IEEE Engineering in Medicine and Biology Society.

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Photosynthetic Physiology of Blue, Green, and Red Light: Light Intensity Effects and Underlying Mechanisms

Frontiers in Plant Science ◽

10.3389/fpls.2021.619987 ◽

2021 ◽

Vol 12 ◽

Author(s):

Jun Liu ◽

Marc W. van Iersel

Keyword(s):

Blue Light ◽

Interactive Effect ◽

Red Light ◽

Green Light ◽

Photosynthetic Photon Flux Density ◽

Interactive Effects ◽

Photon Flux ◽

Photon Flux Density ◽

Light Spectrum ◽

Response Curves

Red and blue light are traditionally believed to have a higher quantum yield of CO2 assimilation (QY, moles of CO2 assimilated per mole of photons) than green light, because green light is absorbed less efficiently. However, because of its lower absorptance, green light can penetrate deeper and excite chlorophyll deeper in leaves. We hypothesized that, at high photosynthetic photon flux density (PPFD), green light may achieve higher QY and net CO2 assimilation rate (An) than red or blue light, because of its more uniform absorption throughtout leaves. To test the interactive effects of PPFD and light spectrum on photosynthesis, we measured leaf An of “Green Tower” lettuce (Lactuca sativa) under red, blue, and green light, and combinations of those at PPFDs from 30 to 1,300 μmol⋅m–2⋅s–1. The electron transport rates (J) and the maximum Rubisco carboxylation rate (Vc,max) at low (200 μmol⋅m–2⋅s–1) and high PPFD (1,000 μmol⋅m–2⋅s–1) were estimated from photosynthetic CO2 response curves. Both QYm,inc (maximum QY on incident PPFD basis) and J at low PPFD were higher under red light than under blue and green light. Factoring in light absorption, QYm,abs (the maximum QY on absorbed PPFD basis) under green and red light were both higher than under blue light, indicating that the low QYm,inc under green light was due to lower absorptance, while absorbed blue photons were used inherently least efficiently. At high PPFD, the QYinc [gross CO2 assimilation (Ag)/incident PPFD] and J under red and green light were similar, and higher than under blue light, confirming our hypothesis. Vc,max may not limit photosynthesis at a PPFD of 200 μmol m–2 s–1 and was largely unaffected by light spectrum at 1,000 μmol⋅m–2⋅s–1. Ag and J under different spectra were positively correlated, suggesting that the interactive effect between light spectrum and PPFD on photosynthesis was due to effects on J. No interaction between the three colors of light was detected. In summary, at low PPFD, green light had the lowest photosynthetic efficiency because of its low absorptance. Contrary, at high PPFD, QYinc under green light was among the highest, likely resulting from more uniform distribution of green light in leaves.

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Role of Short-wavelength Blue Light in the Formation of Cataract and Expression of Caspase-1, -11 and Gasdermin D in rat Lens Epithelium Cells: Insight into the Novel Pathogenesis of Cataract.

10.21203/rs.2.18560/v1 ◽

2019 ◽

Author(s):

Yamin Wang ◽

Min Zhang ◽

Ying Sun ◽

Xiaohui Wang ◽

Zhaowei Song ◽

...

Keyword(s):

Blue Light ◽

Short Wavelength ◽

Light Exposure ◽

The Novel ◽

Blue Led ◽

Caspase 1 ◽

Epithelium Cells ◽

Experimental Group ◽

Insight Into

Abstract Background Cataracts have been verified to be associated with a number of risk factors. The sun and artificial light sources, including light-emitting diode (LED) and fluorescent light tubes, are the primary sources of short-wavelength blue light. With the increasing popularity of blue-rich LED-backlit display devices, our eyes are now exposed to more short-wavelength blue light than they were in the past. The goal of this study was to evaluate the role of short-wavelength blue light in the formation of cataract. Additionally, the pathogenesis of cataracts after short-wavelength light exposure was investigated.Methods SD rats were randomly divided into 2 main groups: a control group (10 rats each for the 4-, 8-, and 12-week groups) and an experimental group (10 rats each for the 4-, 8-, and 12-week groups). The rats in the experimental group were exposed to a short-wavelength blue LED lamp for 12 hours per day. After exposure to the blue LED lamp, the rats were maintained in total darkness for 12 hours, after which a 12-hour light/dark cycle was resumed. The intensity of the lamp was 3000 lux. At the end of the short-wavelength blue LED lamp exposure (for 4, 8, and 12 weeks), the expression levels of caspase-1, caspase-11 and gasdermin D (GSDMD) in rat epithelium cells (LECs) were examined in rat epithelial cells (LECs) using qRT-PCR and Western blotting analyses. Results After 6 weeks, cataracts had developed in the experimental rats (4/20 eyes). The clarity of the lens then gradually worsened with the duration of exposure. Twelve weeks later, all of the rat eyes had developed cataracts. Then the expression levels of caspase-1, caspase-11 and GSDMD at 4, 8, and 12 weeks were significantly higher in samples from rats exposed to a short-wavelength blue LED lamp than samples from control rat (p˂0.05). Conclusion The data indicate that pyroptosis play a key role of in cataracts induced by short-wavelength blue light exposure, highlighting caspase-1, caspase-11 and GSDMD as possible therapeutic targets for cataract treatment. This study might provide new insight into the novel pathogenesis of cataracts.

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Prior Light Exposure Enhances the Pupil Response to Subsequent Short Wavelength (Blue) Light

Journal of Clinical & Experimental Ophthalmology ◽

10.4172/2155-9570.1000152 ◽

2011 ◽

Vol 02 (05) ◽

Cited By ~ 6

Author(s):

Michael Stormly Hansen ◽

Birgit Sander ◽

Aki Kawasaki ◽

Adam Elias Brøndsted ◽

Claus Nissen

Keyword(s):

Blue Light ◽

Short Wavelength ◽

Light Exposure ◽

Pupil Response

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Role of short-wavelength blue light in the formation of cataracts and the expression of caspase-1, caspase-11, Gasdermin D in rat lens epithelial cells: insights into a novel pathogenic mechanism of cataracts

BMC Ophthalmology ◽

10.1186/s12886-020-01565-z ◽

2020 ◽

Vol 20 (1) ◽

Author(s):

Yamin Wang ◽

Min Zhang ◽

Ying Sun ◽

Xiaohui Wang ◽

Zhaowei Song ◽

...

Keyword(s):

Epithelial Cells ◽

Blue Light ◽

Short Wavelength ◽

Pathogenic Mechanism ◽

Lens Epithelial Cells ◽

Caspase 1

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Antibacterial Activity of Blue Light against Nosocomial Wound Pathogens Growing Planktonically and as Mature Biofilms

Applied and Environmental Microbiology ◽

10.1128/aem.00756-16 ◽

2016 ◽

Vol 82 (13) ◽

pp. 4006-4016 ◽

Cited By ~ 49

Author(s):

Fenella D. Halstead ◽

Joanne E. Thwaite ◽

Rebecca Burt ◽

Thomas R. Laws ◽

Marina Raguse ◽

...

Keyword(s):

Blue Light ◽

Mammalian Cells ◽

Wide Spectrum ◽

Great Promise ◽

Bacterial Biofilms ◽

Light Spectrum ◽

Biofilm Growth ◽

Content Type ◽

Elizabethkingia Meningoseptica

ABSTRACTThe blue wavelengths within the visible light spectrum are intrinisically antimicrobial and can photodynamically inactivate the cells of a wide spectrum of bacteria (Gram positive and negative) and fungi. Furthermore, blue light is equally effective against both drug-sensitive and -resistant members of target species and is less detrimental to mammalian cells than is UV radiation. Blue light is currently used for treating acnes vulgaris andHelicobacter pyloriinfections; the utility for decontamination and treatment of wound infections is in its infancy. Furthermore, limited studies have been performed on bacterial biofilms, the key growth mode of bacteria involved in clinical infections. Here we report the findings of a multicenterin vitrostudy performed to assess the antimicrobial activity of 400-nm blue light against bacteria in both planktonic and biofilm growth modes. Blue light was tested against a panel of 34 bacterial isolates (clinical and type strains) comprisingAcinetobacter baumannii,Enterobacter cloacae,Stenotrophomonas maltophilia,Pseudomonas aeruginosa,Escherichia coli,Staphylococcus aureus,Enterococcus faecium,Klebsiella pneumoniae, andElizabethkingia meningoseptica. All planktonic-phase bacteria were susceptible to blue light treatment, with the majority (71%) demonstrating a ≥5-log10decrease in viability after 15 to 30 min of exposure (54 J/cm2to 108 J/cm2). Bacterial biofilms were also highly susceptible to blue light, with significant reduction in seeding observed for all isolates at all levels of exposure. These results warrant further investigation of blue light as a novel decontamination strategy for the nosocomial environment, as well as additional wider decontamination applications.IMPORTANCEBlue light shows great promise as a novel decontamination strategy for the nosocomial environment, as well as additional wider decontamination applications (e.g., wound closure during surgery). This warrants further investigation.

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Transparent Schottky Photodiodes: Transparent Schottky Photodiode Based on AgNi NWs/SrTiO 3 Contact with an Ultrafast Photoresponse to Short‐Wavelength Blue Light and UV‐Shielding Effect (Adv. Funct. Mater. 46/2019)

Advanced Functional Materials ◽

10.1002/adfm.201970319 ◽

2019 ◽

Vol 29 (46) ◽

pp. 1970319

Author(s):

Wei Yang ◽

Yong Zhang ◽

Yujia Zhang ◽

Wanjun Deng ◽

Xiaosheng Fang

Keyword(s):

Blue Light ◽

Short Wavelength ◽

Shielding Effect ◽

Uv Shielding ◽

Schottky Photodiode

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Blue light reduces organ injury from ischemia and reperfusion

Proceedings of the National Academy of Sciences ◽

10.1073/pnas.1515296113 ◽

2016 ◽

Vol 113 (19) ◽

pp. 5239-5244 ◽

Cited By ~ 14

Author(s):

Du Yuan ◽

Richard D. Collage ◽

Hai Huang ◽

Xianghong Zhang ◽

Benjamin C. Kautza ◽

...

Keyword(s):

Blue Light ◽

Ischemia Reperfusion ◽

High Mobility ◽

Kidney Injury ◽

Organ Injury ◽

Fluorescent Light ◽

Protective Mechanism ◽

Hepatocellular Injury ◽

Light Spectrum ◽

Bright Blue

Evidence suggests that light and circadian rhythms profoundly influence the physiologic capacity with which an organism responds to stress. However, the ramifications of light spectrum on the course of critical illness remain to be determined. Here, we show that acute exposure to bright blue spectrum light reduces organ injury by comparison with bright red spectrum or ambient white fluorescent light in two murine models of sterile insult: warm liver ischemia/reperfusion (I/R) and unilateral renal I/R. Exposure to bright blue light before I/R reduced hepatocellular injury and necrosis and reduced acute kidney injury and necrosis. In both models, blue light reduced neutrophil influx, as evidenced by reduced myeloperoxidase (MPO) within each organ, and reduced the release of high-mobility group box 1 (HMGB1), a neutrophil chemotactant and key mediator in the pathogenesis of I/R injury. The protective mechanism appeared to involve an optic pathway and was mediated, in part, by a sympathetic (β3 adrenergic) pathway that functioned independent of significant alterations in melatonin or corticosterone concentrations to regulate neutrophil recruitment. These data suggest that modifying the spectrum of light may offer therapeutic utility in sterile forms of cellular injury.

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Short-Wavelength Blue Light Contributes to Pyroptosis of Human Lens Epithelial Cells (hLECs) by Caspase-1-GSDMD Signalling Axis Activation

10.21203/rs.3.rs-44771/v1 ◽

2020 ◽

Author(s):

Zhaowei Song ◽

Xiaohui Wang ◽

Huazhang Li ◽

Ying Sun ◽

Kexin Liu ◽

...

Keyword(s):

Flow Cytometry ◽

Cell Death ◽

Epithelial Cells ◽

Blue Light ◽

Short Wavelength ◽

Human Lens ◽

Lens Epithelial Cells ◽

Expression Levels ◽

Human Lens Epithelial Cells ◽

Caspase 1

Abstract Backgroud: To examine the effects of short-wavelength blue light (SWBL) on cultured human lens epithelial cells (hLECs). The nosogenesis of cataracts after SWBL exposure was discussed. Methods: HLE-B3 hLECs were divided into 3 groups randomly: A: normal control group, which consisted of hLECs cultured in the dark; B: the caspase-1 inhibitor group; and C: the SWBL exposure group. After the SWBL (2500 lux) irradiation (for 8, 16, 24, and 32 h), the caspase-1 and gasdermin D (GSDMD) expression levels in HLE-B3 hLECs were examined using ELISA, immunofluorescence, and Western blotting analyses. Double-positive staining of HLE-B3 hLECs for activated and inhibited caspase-1 was used to confirm pyroptosis in hLECs by flow cytometry. Results: SWBL can cause cell death in HLE-B3 hLECs, but a caspase-1 inhibitor suppressed cell death. The flow cytometry results also confirmed the does-dependent of short-wavelength blue light irradiation on pyroptotic death of hLECs. Caspase-1 and GSDMD expression levels of all hLECs groups changed with short-wavelength blue light exposure times (8, 16, 24, and 32 h) and were higher in groups B and C than group A. The immunofluorescence results demonstrated that the expression of GSDMD-N was higher in the cell membrane in both the B and C groups than in the A group.Conclusion: The data indicate that SWBL induces pyroptotic programmed cell death by activation of the GSDMD signalling axis in HLE-B3 hLECs. These results provide new insights into the exploitation of new candidates for the prevention of cataracts.

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