Specific Wavelength Research Articles

Untethered wavelength-selective multi-shape programmable hybrid soft robot

Untethered stimuli-responsive soft robotics is a promising field with potential applications in healthcare, automation, and human-robot interaction. However, current limitations restrict many soft robots to binary shape actuation, limiting their functionality to a single mechanical task. In this study, we introduce an untethered wavelength-selective multi-shape programmable soft robot using silicone/hydrogel materials. By leveraging metal nanoparticle-embedded silicone elastomer, our robot achieves reversible shape transformations in response to specific light wavelengths. We also engineered multiple distinct stiffness in key components like hinges and panels, enabling origami-like folding actuation. Our fabricated robot demonstrates four distinct shape morphologies controlled by two light wavelengths. This innovative combination of materials and selective actuation mechanism lays a strong foundation for advanced soft robotic systems capable of diverse mechanical tasks.

Multispectral Land Surface Reflectance Reconstruction Based on Non-Negative Matrix Factorization: Bridging Spectral Resolution Gaps for GRASP TROPOMI BRDF Product in Visible

In satellite remote sensing, mixed pixels commonly arise in medium- and low-resolution imagery, where surface reflectance is a combination of various land cover types. The widely adopted linear mixing model enables the decomposition of mixed pixels into constituent endmembers, effectively bridging spectral resolution gaps by retrieving the spectral properties of individual land cover types. This study introduces a method to enhance multispectral surface reflectance data by reconstructing additional spectral information, particularly in the visible spectral range, using the TROPOMI BRDF product generated by the Generalized Retrieval of Atmosphere and Surface Properties (GRASP) algorithm. Employing non-negative matrix factorization (NMF), the approach extracts spectral basis vectors from reference spectral libraries and reconstructs key spectral features using a limited number of wavelength bands. The comprehensive test results show that this method is particularly effective in supplementing surface reflectance information for specific wavelengths where gas absorption is strong or atmospheric correction errors are significant, demonstrating its applicability not only within the 400–800 nm range but also across the broader spectral range of 400–2400 nm. While not a substitute for hyperspectral observations, this approach provides a cost-effective means to address spectral resolution gaps in multispectral datasets, facilitating improved surface characterization and environmental monitoring. Future research will focus on refining spectral libraries, improving reconstruction accuracy, and expanding the spectral range to enhance the applicability and robustness of the method for diverse remote sensing applications.

The Combination of Active-Targeted Photodynamic Therapy and Photoactivated Chemotherapy for EnhancedCancer Treatment.

Scientists have been actively investigating novel therapies that can effectively eradicate cancer cells with negligible side effects in normal tissues when used alone or in a combinatorial approach. Photodynamic therapy has emerged as a promising non-invasive therapy that integrates photosensitizer, oxygen, and a specific wavelength of light for the treatment of cancer. Despite encouraging outcomes yielded by PDT, conventional PSs are faced with longstanding challenges such as poor water solubility, a short half-life, and off-target toxicity. Development of nanotherapeutics has shown great potential in overcoming this issue. The tumor microenvironment is inherently hypoxic, and this promotes tumor resistance to PDT, as it is oxygen-dependent. Photoactivated chemotherapy, an oxygen-independent light-based therapy, utilizes chemotherapeutic regimens that remain inert until exposed to light, allowing target-specific activation while minimizing off-target toxicity. Integration of these techniques can improve selectivity and yield synergistic cytotoxic effects that could improve cancer treatment.

Multiple pyrazolyazoindole/indazoles scaffolds-based visible-light photoswitches with versatile controlled photophysical properties.

Azoheteroarenes-based photoswitches with high bidirectional isomerization and long thermal half-life (t1/2) have attracted widespread attention from researchers. The diversity of molecular scaffolds has a profound impact on photoswitching performance, herein, we incorporated dynamic connection sites and scaffold optimization to construct a series of pyrazolyazoindole/indazoles (PAIs)-based photoswitches with adjustable photoswitching properties and versatile photophysical properties upon the irradiation of special wavelength, among them 4Z-H can be switched between states "lock" and "unlock" by Cu2+ ion and EDTA. Thermal stability of series 3Z and 4Z was more stable than other PAIs photoswitches for their intramolecular forces, while the steric effect weakened the thermal stability of series 5D, these results clarified the relationship between the PAIs scaffolds and their photoswitching properties. More importantly, ionic photoswitches (4D-N+) synthesized by modification of quaternary ammonium salt fragment exhibited excellent reversible photoswitching properties in aqueous solution with alkaline condition and concentrated glutathione (GSH). The assembly of fluorescence group (triphenylamine) endowed the PAIs scaffolds with optically controlled fluorescence properties. This research elucidated the relationship of scaffold-modification-function of PAIs and would inevitably provide a reliable foundation for the development of intelligent organic materials with photoswitching systems.

Photodynamic therapy for treating vulvar lichen sclerosus

Vulvar lichen sclerosus (VLS) is a chronic inflammatory dystrophic disease affecting the external genitalia, significantly deteriorating the woman’s quality of life and producing an extremely negative effect at her mental status. In case of inefficacy and/or contraindications to traditional pharmacological therapy, modern non-invasive apparatus-based treatment can serve as an alternative. Among them is photodynamic therapy (PDT) which affects targeting tissues with a proper photosensitizing agent and a direct irradiation with light of a specific wavelength. The authors describe their experience in treating 28 patients with VLS who had a course of three PDT sessions. As a result, 82 % of them had a complete symptom remission with no serious adverse effects and excellent therapy tolerance.

Photoacoustic Imaging for Image-Guided Gastric Tube Placement: Ex Vivo Characterization.

Over 250,000 gastrostomy tubes (G-tubes) are placed annually in the United States. Percutaneous endoscopic gastrostomy (PEG) is the most widely used clinical method for placing G-tubes within the stomach. However, endoscope detectability is limited due to the scattering of light by tissues. Poor organ visibility and low sensitivity of the palpation techniques cause blind needle insertions, which cause colon/liver perforations, abdominal bleeding, and gastric resections. Additionally, imaging artifacts and the poor distinguishability between water-filled tissues make ultrasound (US) imaging-based techniques incompatible with G-tube placement. The risk of ionizing radiation exposure and the confinement of fluoroscopy to radiology suites limits its bedside utility in patients. Considering these limitations, we propose to design a safe, point-of-care integrated US and photoacoustic (PA) imaging system for accurate G-tube placement procedures, for a broad spectrum of patients, and to characterize the system's effectiveness. Our proposed technology utilizes a clinically safe contrast agent and a dual-wavelength approach for precise procedures. Our ex vivo tissue studies indicated that PA imaging accurately differentiates the different organs at specific wavelengths. Our characterization studies revealed that PA imaging could detect lower concentrations of Indocyanine Green (ICG) dye coating the colon wall, minimizing the risk of ICG dye-related toxicity and providing safer G-tube placements.

Efficacy of Light-Emitting Diode-Mediated Photobiomodulation in Tendon Healing in a Murine Model

The application of light-emitting diode (LED)-dependent photobiomodulation (PBM) in promoting post-tendon injury healing has been recently reported. Despite establishing a theoretical basis for ligament restoration through PBM, identifying effective LED wavelength combinations and ensuring safety in animal models remain unresolved challenges. In our previous study, we demonstrated that combined irradiation at 630 nm and 880 nm promotes cell proliferation and migration, which are critical processes during the early stage of tendon healing in human-derived tendon fibroblasts. Based on this, we hypothesized that 630/880 nm LED-based PBM might promote rapid healing during the initial phase of tendon healing, and we aimed to analyze the results after PBM treatment in a murine model. Migration kinetics were analyzed at two specific wavelengths: 630 and 880 nm. The Achilles tendon in the hind limbs of Balb/c mice was severed by Achilles tendon transection. Subsequently, the mice were randomized into LED non-irradiation and LED irradiation groups. Mice with intact tendons were employed as healthy controls. The total number of mice was 13 for the healthy and injured groups and 14 for the LED-irradiated injured group, and the data presented in this manuscript were obtained from one representative experiment (n = 4–5 per group). The wounds were LED-irradiated for 20 min daily for two days. Histological properties, tendon healing mediators, and inflammatory mediators were screened on day 14. The roundness of the nuclei and fiber structure, indicating the degree of infiltrated inflammatory cells and severity of fiber fragmentation, respectively, were lower in the LED irradiation group than in the LED non-irradiation group. Immunohistochemical analysis depicted an increase in tenocytes (SCX+ cells) and recovery of wounds with reduced fibrosis (lower collagen 3 and TGF-β1) in the LED irradiation group during healing; conversely, the LED non-irradiation group exhibited tissue fibrosis. Overall, the ratio of M2 macrophages to total macrophages in the LED irradiation group was higher than that in the injured group. LED-based PBM in the Achilles tendon rupture murine model facilitated a rapid restoration of histological and immunochemical outcomes. These findings suggest that LED-based PBM presents remarkable potential as an adjunct therapeutic approach for tendon healing and warrants further research to standardize various parameters to advance and establish it as a reliable treatment regimen.

Light-based technologies in immunotherapy: advances, mechanisms and applications.

Light-based immunotherapy uses specific wavelengths of light to activate or modulate immune responses. It primarily employs two mechanisms: direct activation of immune cells and indirect modulation of the tumor microenvironment (TME). Several light-based technologies are under investigation or clinical use in immunotherapy, including photodynamic immunotherapy (PDIT) and photothermal therapy (PTT). Optogenetic tools have the potential to precisely control T-cell receptor activation, cytokine release, or the activity of other immune effector cells. Light-based technologies present innovative opportunities within the realm of immunotherapy. The ability to precisely regulate immune cell activation via optogenetics, alongside the improved targeting of cancer cells through photoimmunotherapy, signifies a transformative shift in our strategies for immune modulation. Although many of these technologies remain in the experimental stage for various applications, initial findings are encouraging, especially concerning cancer treatment and immune modulation. Continued research and clinical trials are essential to fully harness the capabilities of light technology in the context of immune cell therapy.

Determining Fluorescence Quantum Yield for 5-(2-(Dimethylamino)-6-Methoxypyrimidin-4-yl)-Furan-2-Carbaldehyde Using Simultaneous Absorption and Fluorescence Emission (SAFE) Method.

Quantum yield (QY) is a fundamental parameter in luminescence study. This paper introduces a novel SAFE method for determining the fluorescence quantum yield of 5-(2-(dimethylamino)-6-methoxypyrimidin-4-yl)-furan-2-carbaldehyde, which was synthesized from pyrimidine derivatives through the Suzuki cross-coupling reaction. A key contribution of this study is integrating measuring tools into a single device, as opposed to using two separate devices typically found in commercial applications. The study utilizes a commercial fluorescence spectrometer capable of recording absorption and emission spectra simultaneously, ensuring precise and efficient measurements. The fluorescence quantum yields of anthracene, quinine sulfate, tyrosine, and the synthesized pharmacological compound were investigated. Quinine sulfate (QS), dissolved in 0.05M sulfuric acid, served as the reference standard on a traceable fluorometer. Measurements were conducted using laboratory-designed quantum yield measurement software based on the SAFE method, yielding results with high accuracy relative to standard values. The quantum yields for tyrosine in water, anthracene, and 5-(2-(dimethylamino)-6-methoxypyrimidin-4-yl)-furan-2-carbaldehyde in ethanol were determined at specific excitation wavelengths. For the first set of excitation wavelengths (λ₁) at 270, 330, and 385nm, the QY values were found to be 13.089, 28.51, and 27.126, respectively. In a second set of excitation wavelengths (λ₂) at 273, 335, and 397nm, the corresponding QY values were determined to be 13.091, 29.153, and 27.354, with quinine sulfate serving as the reference standard at λ₁ (299nm) and λ₂ (310nm). These findings demonstrate the effectiveness of the SAFE method in accurately determining fluorescence quantum yields, offering significant utility for characterizing luminescent compounds and evaluating pharmacological substances.

Fungal derived dye as potential photosensitizer for antimicrobial photodynamic therapy.

Fungal derived dye as potential photosensitizer for antimicrobial photodynamic therapy.

Tree diversity shapes the spectral signature of light transmittance in developing forests.

Greater tree diversity often increases forest productivity by increasing the fraction of light captured and the effectiveness of light use at the community scale. However, light may shape forest function not only as a source of energy or a cause of stress but also as a context cue: Plant photoreceptors can detect specific wavelengths of light, and plants use this information to assess their neighborhoods and adjust their patterns of growth and allocation. These cues have been well documented in laboratory studies, but little studied in diverse forests. Here, we examined how the spectral profile of light (350-2200 nm) transmitted through canopies differs among tree communities within three diversity experiments on two continents (200 plots each planted with one to 12 tree species, amounting to roughly 10,000 trees in total), laying the groundwork for expectations about how diversity in forests may shape light quality with consequences for forest function. We hypothesized-and found-that the species composition and diversity of tree canopies influenced transmittance in predictable ways. Canopy transmittance-in total and in spectral regions with known biological importance-principally declined with increasing leaf area per ground area (LAI) and, in turn, LAI was influenced by the species composition and diversity of communities. For a given LAI, broadleaved angiosperm canopies tended to transmit less light with lower red-to-far-red ratios than canopies of needle-leaved gymnosperms or angiosperm-gymnosperm mixtures. Variation among communities in the transmittance of individual leaves had a minor effect on canopy transmittance in the visible portion of the spectrum but contributed beyond this range along with differences in foliage arrangement. Transmittance through mixed species canopies often deviated from expectations based on monocultures, and this was only partly explained by diversity effects on LAI, suggesting that diversity effects on transmittance also arose through shifts in the arrangement and optical properties of foliage. We posit that differences in the spectral profile of light transmitted through diverse canopies serve as a pathway by which tree diversity affects some forest ecosystem functions.

Determination of the Enantiomerization Barrier of Midazolam in Aqueous Conditions by Electronic Circular Dichroism and Dynamic Enantioselective HPLC/UHPLC

Midazolam is a benzodiazepine that is utilized for the induction of anesthesia and the facilitation of procedural sedation. Despite the absence of stereogenic centers, the non-planar seven-membered ring devoid of reflection symmetry elements confers planar stereogenicity to the molecule. Due to the rapid conformational inversion of the Rp and Sp enantiomers, which occurs via a simple ring flip, high-performance liquid chromatography (HPLC) enantiomeric separation is restricted to sub-room temperature conditions. In this study, the energy barriers for the racemization of midazolam at five distinct temperatures and in acetonitrile/water mixtures were determined by monitoring the decay of the circular dichroism signal at a specific wavelength over time. The kinetic and thermodynamic data obtained were compared with those determined by dynamic enantioselective high-performance liquid chromatography using the Chiralpak IG-3 chiral stationary phase, which contains the amylose tris(3-chloro-5-methylphenylcarbamate) as the selector. The temperature-dependent dynamic HPLC of midazolam was carried out at the same temperatures and with the same aqueous mixtures used in parallel kinetic off-column experiments. To simulate dynamic chromatographic profiles, a lab-made computer program based on a stochastic model was utilized. The results indicated that the moderate influence of the stationary phase resulted in a slight increase in the activation barriers, which was more pronounced as the time spent in the column increased. This phenomenon was found to be mitigated when switching from a 250 mm × 4.6 mm, 3 µm, Chiralpak IG-3 column to a 50 mm × 4.6 mm, 1.6 µm, Chiralpak IG-U UHPLC column. The outcomes obtained under UHPLC conditions were found to be more closely aligned with those obtained through the ECD technique, with a discrepancy of only 0.1 kcal/mol or less, indicating a high degree of concordance between the two methods.

Tailoring Hole‐Blocking Layers Enables a Versatile Approach for Fast Photomultiplication‐Type Organic Photodetectors

AbstractOrganic photodetectors (OPDs) are promising for various applications due to their cost‐effectiveness in fabrication, flexibility, and tunable response to specific wavelengths. Their excellent sensitivity enables multiple applications in imaging, healthcare, and security monitoring. Notably, photomultiplication‐type organic photodetectors (PM‐OPDs) offer distinct advantages due to their internal amplification mechanism. In this work, a strategy is presented for employing two hole‐blocking layers (HBLs) to improve the photodetection capabilities of PM‐OPDs. A systematic exploration of the HBL material combination reveals the importance of shallow lowest unoccupied molecular orbital (LUMO) and deep highest occupied molecular orbital (HOMO) levels for optimal performance. Utilizing HBLs with deep HOMO levels, HAT(CN)6 and C60, leads to enhanced hole accumulation, resulting in a distinct photomultiplication effect. Optimized devices exhibit an impressive external quantum efficiency (EQE) surpassing 1290%, shot‐noise limited specific detectivity of 1.7 × 1012 Jones (2.4 × 1011 Jones based on noise measurements), and a rapid cutoff frequency exceeding 40 kHz, representing a significant advancement in PM‐OPD capabilities. Moreover, this device architecture surpasses current limitations by ensuring compatibility with various photoactive layers with balanced donor‐acceptor stoichiometry. Our results confirm this universal approach, which enables high‐gain PM‐OPDs across spectral ranges while maintaining fast response speeds.

Killing effect of antibacterial photodynamic therapy with long-term exposure against young and mature Enterococcus faecalis biofilms in dentin

BackgroundThe main cause of pulpal and periapical diseases is bacterial infection, but mechanical and chemical preparation in root canal therapy is difficult to completely remove the bacterial microorganism. Antibacterial photodynamic therapy (aPDT) is a medical method that kills microorganisms by activating a photoactive agent or photosensitizer by exposure to visible light of a specific wave-length in the presence of oxygen. The present study aimed to evaluate the killing in vitro effect of aPDT with 0.01% methylene blue (MB) against young and mature Enterococcus faecalis (E. faecalis) biofilms in bovine and human dentin with the long-term exposure using confocal laser scanning microscopy (CLSM).MethodsPrepared bovine and human dentin blocks and their structure were observed by scanning electron microscopy (SEM). Semicylindrical bovine dentin blocks and human root canal dentin blocks were inoculated with E. faecalis and incubated in air to form 1- and 3-week-old biofilms. The biofilms in dentin were subjected to aPDT with 0.01% MB, 5% NaOCl and saline with the exposure of 3, 12 and 30 min. The dead portions of bacterial cells in E. faecalis biofilms were analyzed with using LIVE/DEAD bacteria viability staining and CLSM.ResultsA clean dentin surface in bovine dentin blocks were verified with SEM. In bovine and human dentin blocks, significantly more bacteria were dead when aPDT with MB and 5% NaOCl were used with the long exposure time (12 and 30 min) than with 3 min (P < 0.05). The speed of killing was fastest during the first 3 min, and few more bacterial cells were killed after 12 min in the disinfection groups. 5% NaOCl exhibited the highest effectiveness of bacterial killing in dentin at each time point than aPDT with MB groups (P < 0.05). The proportion of killed bacteria was higher in young biofilms than in mature biofilms in aPDT with MB and NaOCl groups (P < 0.05). Moreover, there were no clearly visible changes in structure of bovine dentin surfaces subjected to aPDT with MB for 30 min.ConclusionaPDT with 0.01% MB has the capability to kill bacterial cells in E. faecalis biofilms on bovine and human dentin blocks. Young E. faecalis biofilms in dentin canals were more susceptible to disinfection approaches than mature biofilms.

Planck’s constant from Stefan’s radiation law: a study of gray radiations of tungsten filament bulb

Abstract This study introduces a straightforward approach to determine Planck’s constant in an undergraduate course at the college or university level through the analyses the current–voltage (I–V) characteristic of a tungsten filament bulb. Unlike conventional methods, this analysis does not require the use of a color filter or an additional photodiode to select a specific wavelength or measure the emitted energy density from the filament. The temperature of the filament was computed by measuring the resistance of the filament. The obtained temperature and the input power of the filament are then used to estimate the emissivity of the filaments using Stefan–Boltzmann’s law, which is found to be lower than that of a perfect black body, i.e. unity. Therefore, the radiation emitted from the tungsten filament can be classified as gray radiation. The maximum energy density (intensity) of the emitted radiation is determined by calculating the consumed power of the filament. Finally, the obtained values of temperature, Stefan’s constant, and the intensity of the emitted radiations are used to calculate Planck’s constant. The calculated value of Planck’s constant is found to be 6.102 × 10−34 Js, which closely matches the standard value of Planck’s constant (6.626 × 10−34 Js). This close correlation between the two values validates the effectiveness of the present method.

A Meticulous Focus on the Determination of Critical Micelle Concentration Employing Fluorescence Spectroscopy.

Micelles are small spherical structures formed by one or a combination of amphiphilic structures known as surfactants. Surfactants are amphiphilic molecules with both hydrophilic and hydrophobic regions and can self-assemble into micelles above the critical micelle concentration, with the hydrophobic tails oriented inwards and hydrophilic head outwards. In this review article, critical micelle concentration determination using the fluorescence spectroscopy technique is described for both single and mixed micellar systems with the preparation of samples, working principle, and also about theoretical aspects. Fluorescence measurements using direct i.e. intrinsic fluorescence of surfactant molecule and indirect i.e. using extrinsic fluorescence probes have been discussed. Fluorescence spectroscopy offers a sensitive and valid approach for the characterization of surfactant behaviors in aqueous solutions. Various fluorescence parameters are measured at specific wavelengths with an increase in surfactant concentration and a plot is generated from which the critical micelle concentration is determined. Furthermore, the calculation of critical packing parameter is also described which gives an idea about the geometrical arrangement of the surfactant molecules in a micellar structure. This value also provides valuable insights into the micelle's shape and structure. In conclusion, the effectiveness of the fluorescence spectroscopy technique in determining the critical micelle concentration and the critical packing parameter is described in detail in this review article.

Engineering in NIR‐responsive photothermal materials and their application in wound healing administration

AbstractWound healing is a complex process that involves multiple stages and is susceptible to various challenges, such as infection, insufficient blood flow, and the body's inadequate response to the healing process, which can be life‐threatening for the patient. In the current medical landscape, traditional treatments often struggle to meet the high standards of modern medical care. Therefore, it is crucial to actively explore and develop new drugs or advanced technologies that can enhance the healing of bacterially infected wounds. In recent years, several physical methods that effectively accelerate wound healing have garnered widespread attention and interest. Among these, Photothermal therapy (PTT) has been extensively utilized in the treatment of bacterial infections and wound healing due to its non‐invasive, low toxicity, and ease of use. The photothermal agents (PTAs) serve as the core material in PTT, and their efficacy is significantly influenced by the specific PTAs employed. Selecting the appropriate PTAs is essential for achieving the desired therapeutic effect. This treatment relies on the PTAs's ability to efficiently convert specific wavelengths of light energy into heat upon absorption, thereby generating a thermal effect at the wound site. Consequently, the properties of the PTAs, including photothermal conversion efficiency, biocompatibility, and stability within the organism, are critical factors that determine the therapeutic outcome. This review introduces organic, inorganic, and organic‐inorganic hybrid PTAs for PTT in wound healing, highlighting their main properties and applications in wound management in recent years. Finally, we briefly discuss the limitations and prospects of this field.

Localisation method of strawberry nursery greenhouse robots based on visual infrared beacons

ABSTRACT Achieving accurate localisation of mobile robots in greenhouse environments is challenging due to interfering factors, such as iron seedbeds, steel frame structures, and fluctuating ambient light conditions. This study proposes a localisation method using monocular vision and infrared LED beacons, which employ specific wavelengths to reduce ambient light impact. In addition, a combination of threshold segmentation and region-growing segmentation is used to extract the infrared LED beacons rapidly from the background. The monocular vision ranging principle is adopted to determine the relative distance between the camera mounted on a mobile platform and the beacons. Also, a trilateral localisation mechanism is used to calculate the mobile platform’s position. Experimental tests on a tracked mobile robot verified the proposed method. In the static localisation experiments, the proposed method has an average absolute error of 5.5 cm and a maximum absolute error of 8.1 cm. In dynamic localisation experiments, at robot speeds of 0.2 m/s and 0.4 m/s, the maximum drift errors are 5.7 cm and 6.0 cm, with average absolute drift errors of 2.0 cm and 2.2 cm, respectively. The results confirm the effectiveness of the proposed method in the precise localisation of robots in challenging greenhouse environments.

Ultraviolet narrowband all-dielectric metasurface absorber with an ultra-thin absorption layer.

Ultraviolet (UV, 200-400 nm) detection with high efficiency and excellent spectral resolution is essential in spectral analysis. This Letter proposes a UV narrowband all-dielectric metasurface absorber with an ultra-thin absorption layer. The design incorporates lossless Al2O3 resonators placed on a thin (20 nm) lossy Ga2O3 film, which enhances the absorption intensity at a specific wavelength. The near-perfect narrowband absorption enhancement results from the spectral overlap of the magnetic dipole (MD) and the electric dipole (ED) absorption modes by surface lattice resonance (SLR). The proposed absorber exhibits high-efficiency and high-quality (Q) absorption performance (A > 95%, Q ∼ 231) and allows for flexible control over the absorption wavelength through simple parameter adjustments. These features make it ideal for narrowband emission, spectrum detection, and multispectral sensing.

Impact of short wavelength light exposure on body weight, mobility, anxiety like behaviour and cytokine expression

Mitochondria absorb short wavelengths around 420 nm. This is associated with reduced ATP and restricted mobility. The 420–450 nm range is a significant element of LED lighting and computer monitors. Here we expose freely moving mice to 420–450 nm lighting and show rapidly weight gain within a week. This may be due to reduced mitochondrial demand for circulating carbohydrates. Both groups displayed marked shifts in serum cytokines. Open field mobility was examined. The distance travelled was similar between both experimental groups and their controls. However, both experimental groups showed avoidance of central regions consistent with anxiety-like behaviours. This was significant in the 420 nm group whose wavelength exposure is closer to peak mitochondrial absorbance. These data demonstrate the potential hazards of exposure to specific short wavelengths in the visual range now common in the built environment. Data are consistent with a wider literature on systemic problems arising from exposure to short wavelength light.