scholarly journals Effects of Changes in Colored Light on Brain and Calf Muscle Blood Concentration and Oxygenation

2011 ◽  
Vol 11 ◽  
pp. 1216-1225
Author(s):  
J. Weinzirl ◽  
M. Wolf ◽  
P. Heusser ◽  
M. Nelle ◽  
U. Wolf
Keyword(s):  
Blue Light ◽  
Blood Volume ◽  
Near Infrared ◽  
Light Exposure ◽  
Red Light ◽  
Light Therapy ◽  
Calf Muscle ◽  
Sequential Order ◽  
Color Changes ◽  
The Brain

Color light therapy is a therapeutic method in complementary medicine. In color therapy, light of two contrasting colors is often applied in a sequential order. The aim of this study was to investigate possible physiological effects, i.e., changes in the blood volume and oxygenation in the brain and calf muscle of healthy subjects who were exposed to red and blue light in sequential order. The hypothesis was that if a subject is first exposed to blue and then red light, the effect of the red light will be enhanced due to the contrastingly different characteristics of the two colors. The same was expected for blue light, if first exposing a subject to red and then to blue light. Twelve healthy volunteers (six male, six female) were measured twice on two different days by near-infrared spectroscopy during exposure to colored light. Two sequences of colored light were applied in a controlled, randomized, crossover design: first blue, then red, and vice versa. For the brain and muscle, the results showed no significant differences in blood volume and oxygenation between the two sequences, and a high interindividual physiological variability. Thus, the hypothesis had to be rejected. Comparing these data to results from a previous study, where subjects were exposed to blue and red light without sequential color changes, shows that the results of the current study appear to be similar to those of red light exposure. This may indicate that the exposure to red light was preponderant and thus effects of blue light were outweighed.

The Efficacy of Blue Light versus the Combination of Blue and Red Light Therapy in the Treatment of Acne Vulgaris

2021 ◽  
Author(s):  
Leila Kharazi ◽  
Sahar Dadkhahfar ◽  
Hoda Rahimi ◽  
Mehdi Gheisari ◽  
Nikoo Mozafari ◽  
...  
Keyword(s):  
Blue Light ◽  
Acne Vulgaris ◽  
Red Light ◽  
Light Therapy

Visible Blue Light Therapy: Molecular Mechanisms and Therapeutic Opportunities

2019 ◽  
Vol 25 (40) ◽  
pp. 5564-5577 ◽  
Author(s):  
Z.C. Félix Garza ◽  
M. Born ◽  
P.A.J. Hilbers ◽  
N.A.W. van Riel ◽  
J. Liebmann
Keyword(s):  
Blue Light ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Near Infrared ◽  
Light Therapy ◽  
Cellular Mechanisms ◽  
Therapeutic Applications ◽  
Cellular Effects ◽  
Inflammatory Skin ◽  
Skin Conditions

Background: Visible light is absorbed by photoacceptors in pigmented and non-pigmented mammalian cells, activating signaling cascades and downstream mechanisms that lead to the modulation of cellular processes. Most studies have investigated the molecular mechanisms and therapeutic applications of UV and the red to near infrared regions of the visible spectrum. Considerably less effort has been dedicated to the blue, UV-free part of the spectrum. Objective: In this review, we discuss the current advances in the understanding of the molecular photoacceptors, signaling mechanisms, and corresponding therapeutic opportunities of blue light photoreception in non-visual mammalian cells in the context of inflammatory skin conditions. Methods: The literature was scanned for peer-reviewed articles focusing on the molecular mechanisms, cellular effects, and therapeutic applications of blue light. Results: At a molecular level, blue light is absorbed by flavins, porphyrins, nitrosated proteins, and opsins; inducing the generation of ROS, nitric oxide release, and the activation of G protein coupled signaling. Limited and contrasting results have been reported on the cellular effects of blue light induced signaling. Some investigations describe a regulation of proliferation and differentiation or a modulation of inflammatory parameters; others show growth inhibition and apoptosis. Regardless of the elusive underlying mechanism, clinical studies show that blue light is beneficial in the treatment of inflammatory skin conditions. Conclusion: To strengthen the use of blue light for therapeutic purposes, further in depth studies are clearly needed with regard to its underlying molecular and cellular mechanisms, and their translation into clinical applications.

scholarly journals Colored Paints Containing NIR-Reflective Pigments Exposed to Accelerated Ultraviolet Radiation Aging with Possible Application as Roof Coatings

Coatings ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1135
Author(s):  
Stefano Rossi ◽  
Hampus Lindmark ◽  
Michele Fedel
Keyword(s):  
Near Infrared ◽  
Light Exposure ◽  
Maximum Temperature ◽  
Potential Candidate ◽  
Light Spectrum ◽  
Ir Camera ◽  
Color Changes ◽  
The Difference ◽  
Steel Panels ◽  
The Stability

This study aims to evaluate the difference in thermal behavior among paints with the presence of traditional and NIR pigments by means of a simple and cheap laboratory-scale test. Considering these goals, the thermal and esthetical properties of two different cool coatings were assessed, highlighting their positive and limited aspects. Two different complex near-infrared inorganic reflective (NIR) pigments with yellow and black respectably colors were mixed in an acrylic waterborne copolymer binder. The paint formulations were applied on steel panels. The thermal performance of the coatings was investigated in the NIR-region of the light spectrum by exposing the samples to an IR-lamp. The outer and inner surface temperatures of the painted panels were recorded using thermocouples and an IR camera. The samples were aged by artificial UV-B light exposure. Color and specular gloss changes at different exposure times were evaluated. The behavior of the cool coatings was compared with that of conventional coatings with similar color characteristics. The black cool coating achieved a maximum temperature decrease, compared to the conventional black one, of approximately 12 °C. The stability for the cool coatings was very similar to that of the conventional coating, indicating that black pigment could be a potential candidate for cool-coating applications. The yellow cool coatings did not show a significant decrease in temperature compared to the conventional paint. The gloss and color changes resulted as influenced by the types and amount of pigments.

scholarly journals 1160 Improved Daytime Sleepiness Following Daily Morning Blue Light Therapy Is Associated With Altered Resting-state Network Connectivity

SLEEP ◽  
2020 ◽  
Vol 43 (Supplement_1) ◽  
pp. A442-A442
Author(s):  
A C Raikes ◽  
N S Dailey ◽  
J R Vanuk ◽  
A Alkozei ◽  
M A Grandner ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Cognitive Control ◽  
Blue Light ◽  
Resting State ◽  
Daytime Sleepiness ◽  
Light Exposure ◽  
Light Therapy ◽  
Post Treatment ◽  
Default Mode ◽  
Positive Effects

Abstract Introduction Light exposure, particularly blue wavelength light, has consistent positive effects on daytime sleepiness following mild traumatic brain injuries (mTBIs). While self-perceived improvements in daytime sleepiness are well-documented, the neurobiological underpinnings are not well understood. The purpose of this study was to localize changes in functional connectivity after daily morning blue light therapy (BLT) and to associate these changes with improvements in post-mTBI daytime sleepiness. Methods 29 individuals with a history of mTBI were randomized to receive either BLT (n=13) or placebo amber light (ALT; n=16). All participants self-reported daytime sleepiness (Epworth Sleepiness Scale (ESS); lower is better) and underwent resting-state functional magnetic resonance imaging at pre- and post-treatment. Whole-brain functional connectivity (FC) was estimated as the correlations between 400 cortical regions of interest (ROIs) assigned to 7 resting-state networks. A two-sample T-test for post-treatment ROI-to-ROI FC identified target connections (FDR corrected p<0.01). Post-treatment ESS scores and FC for these connections were correlated for treatment-related brain-behavior associations (uncorrected p<0.05). Results Lower FC after BLT in 4 ROI-to-ROI connections linking the default mode and visual networks was associated with lower ESS scores. Higher FC after BLT in 9 ROI-to-ROI connections linking attention, cognitive control, and visual networks was also associated with lower ESS scores. Conclusion BLT resulted in decreased self-reported daytime sleepiness, which was associated with decoupling of the default mode and visual networks as well as increased connectivity between and within attention and cognitive control networks, suggesting potentially improved attention to relevant stimuli and cognitive processes and less internal mentation. These associations may contribute to improved alertness, attention, and cognitive performance following a mTBI. Further work is needed to identify the optimal timing and dosage of BLT to maximize these outcomes. Support This study was funded by an award to Dr. Killgore from the US Army Medical Research and Materiel Command (USAMRMC; award number: W81XWH-14-1-0571).

scholarly journals Individual Differences in Hemodynamic Responses Measured on the Head Due to a Long-Term Stimulation Involving Colored Light Exposure and a Cognitive Task: A SPA-fNIRS Study

2021 ◽  
Vol 11 (1) ◽  
pp. 54
Author(s):  
Hamoon Zohdi ◽  
Felix Scholkmann ◽  
Ursula Wolf
Keyword(s):  
Near Infrared ◽  
Light Exposure ◽  
Cognitive Task ◽  
Arterial Oxygen Saturation ◽  
Red Light ◽  
Hemodynamic Response ◽  
Arterial Oxygen ◽  
Intersubject Variability ◽  
Hemodynamic Responses ◽  
Functional Near Infrared Spectroscopy

When brain activity is measured by neuroimaging, the canonical hemodynamic response (increase in oxygenated hemoglobin ([O2Hb]) and decrease in deoxygenated hemoglobin ([HHb]) is not always seen in every subject. The reason for this intersubject-variability of the responses is still not completely understood. This study is performed with 32 healthy subjects, using the systemic physiology augmented functional near-infrared spectroscopy (SPA-fNIRS) approach. We investigate the intersubject variability of hemodynamic and systemic physiological responses, due to a verbal fluency task (VFT) under colored light exposure (CLE; blue and red). Five and seven different hemodynamic response patterns were detected in the subgroup analysis of the blue and red light exposure, respectively. We also found that arterial oxygen saturation and mean arterial pressure were positively correlated with [O2Hb] at the prefrontal cortex during the CLE-VFT independent of the color of light and classification of the subjects. Our study finds that there is substantial intersubject-variability of cerebral hemodynamic responses, which is partially explained by subject-specific systemic physiological changes induced by the CLE-VFT. This means that both subgroup analyses and the additional assessment of systemic physiology are of crucial importance to achieve a comprehensive understanding of the effects of a CLE-VFT on human subjects.

scholarly journals Establishment and initial characterization of a simple 3D wound healing model

2019 ◽  
Vol 5 (1) ◽  
pp. 581-584
Author(s):  
Sabine Hensler ◽  
Claudia Kühlbach ◽  
Jacquelyn Dawn Parente ◽  
Knut Moeller ◽  
Margareta M. Mueller
Keyword(s):  
Wound Healing ◽  
Blue Light ◽  
Wound Closure ◽  
Chronic Wounds ◽  
Wave Length ◽  
Red Light ◽  
Inflammatory Cells ◽  
Light Therapy ◽  
Gm Csf

Abstract Poor wound healing as consequence of malfunctions in the regulation of the healthy tissue repair response affects millions of people worldwide. The number of therapies available to successfully treat chronic wound is still very limited and their development is costly and time consuming. Therefore simple to use 3D systems, reflecting the in vivo tissue complexity, are urgently needed. We introduce a novel 3D organotypic model (OTC) containing the major cell components active during wound healing i.e. keratinocytes, fibroblasts and inflammatory cells that allows to determine the effects of different therapeutic approaches on wound closure, cell differentiation and cytokine secretion in chronic wounds. There are first reports on irradiation with visible light of different wave length (Low Level Light Therapy) as a means to enhance wound closure. However the mechanisms underlying this therapy as well as optimized irradiation wavelength and dose are not clear and were therefore analyzed using our 3D organotypic model. In the standardized OTC model we could demonstrate epithelial closure under control conditions as well as differential effects of red and blue light irradiation with respect to stability of the newly formed epithelium and time until epithelial closure. First results show differential cytokine profiles upon different wavelength irradiation e.g. high expression of TGF beta and IL-1 beta in red light irradiated cultures and increased GM-CSF expression in blue light irradiated and control cultures.

Changes in activity and light exposure rhythms by timed blue light therapy in Alzheimer's disease patients

2019 ◽  
Vol 64 ◽  
pp. S198
Author(s):  
S.J. Kim ◽  
S.H. Lee ◽  
I.B. Suh ◽  
J.-W. Jang ◽  
J.H. Jhoo ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Blue Light ◽  
Light Exposure ◽  
Light Therapy

Effects of Colours on the Insane

1876 ◽  
Vol 22 (97) ◽  
pp. 167
Keyword(s):  
Optic Nerve ◽  
Blue Light ◽  
Red Light ◽  
Lunatic Asylum ◽  
Solar Light ◽  
The Sun ◽  
Violet Light ◽  
Magnetic Perturbations ◽  
The Brain ◽  
Solar Rays

The “Gazette des Hôpitaux” contains a curious article on this subject. Dr. Ponza, director of the lunatic asylum at Alessandria, Piedmont, having conceived the idea that the solar rays might have some curative power in diseases of the brain, communicated his views to Father Secchi, of Rome, who replied in the following terms:—“The idea of studying the disturbed state of lunatics in connection with magnetic perturbations, and with the coloured, especially violet, light of the sun, is of remarkable importance, and I consider it well worth being cultivated.” Such light is easily obtained by filtering the solar rays through a glass of that colour. “Violet,” adds Father Secchi, “has something melancholy and depressive about it, which, physiologically, causes low spirits; hence, no doubt, poets have draped melancholy in violet garments. Perhaps violet light may calm the nervous excitement of unfortunate maniacs.” He then, in his letter, advises Dr. Ponza to perform his experiments in rooms the walls of which are painted of the same colour as the glass panes of the windows, which should be as numerous as possible, in order to favour the action of solar light, so that it may be admissible at any hour of the day. The patients should pass the night in rooms oriented to the east and south, and painted and glazed as above. Dr. Ponza, following the instructions of the learned Jesuit, prepared several rooms in the manner described, and kept several patients there under observation. One of them, affected with morbid taciturnity, became gay and affable after three hours' stay in a red chamber; another, a maniac who refused all food, asked for some breakfast after having stayed twenty-four hours in the same red chamber. In a blue one, a highly excited madman with a straight waistcoat on was kept all day; an hour after he appeared much calmer. The action of blue light is very intense on the optic nerve, and seems to cause a sort of oppression. A patient was made to pass the night in a violet chamber; on the following day he begged Dr. Ponza to send him home, because he felt himself cured, and indeed he has been well ever since. Dr. Ponza's conclusions from his experiments are these:—“The violet rays are, of all others, those that possess the most intense electro-chemical power; the red light is also very rich in calorific rays; blue light, on the contrary, is quite devoid of them, as well as of chemical and electric ones. Its beneficient influence is hard to explain; as it is the absolute negation of all excitement, it succeeds admirably in calming the furious excitement of maniacs,”—English Mechanic, March 3rd, 1876.

Sign in / Sign up

Export Citation Format

Share Document