LED Light Research Articles

Effects of LED polarized and vortex light on growth and photosynthetic characteristics of pepper (Capsicum annuum L.)

Most studies currently focus on traditional illuminant regulating plant growth, while less attention has been given to the LED internal luminescence. This study examined how polarized and vortex light affect the growth and photosynthetic traits of pepper plants, with LED light used as the control. The findings indicated that circular polarized light significantly increased the aboveground biomass of pepper. Additionally, both polarized and vortex light treatment significantly influenced the root development of pepper. In comparison to the control group, the chlorophyll content was highest under circular polarized light, while the Pn, Sc, Tr, and Ci values were highest under linear polarized light, and the enzyme activity of Rubisco was increased. Circular polarized light notably increased the activities of POD, CAT, and SOD, the activity of SOD reached its peak under the left vortex light. Moreover, the content of MDA was observed to be the lowest under linear and right vortex light treatments. The expressions of key genes for chlorophyll synthesis (CaHEMA1 and CaCAO) and antioxidant enzyme synthesis (CaPOD, CaSOD, and CaMDHAR) were significantly altered under varying polarized light conditions, The latter genes, which play crucial roles in antioxidant enzyme activity, also showed significant variations in response to different polarized light treatments. In conclusion, polarized light significantly impacts the growth of pepper and is anticipated to be utilized for plant growth, setting the stage for future research in this area.

Blue Light-Induced Accelerated Formation of Melanolipofuscin-Like Organelles in Japanese Quail RPE Cells: An Electron Microscopic Study.

The retinal pigment epithelium (RPE) is a monolayer of epithelial cells essential for photoreceptor function and viability. Quail Coturnix japonica is a convenient experimental animal model for the study of age and pathological retina processes to an accelerated time regime. The three main types of pigment granules present in the RPE are melanin-containing melanosomes, lipofuscin-containing lipofuscin granules, and mixed melanolipofuscin granules containing both melanin and lipofuscin. The purpose of this work was to study the process of melanolipofuscinogenesis during aging and under light exposure. We examined melanolipofuscin granules in "macular" areas, the area of the retina containing oxycarotenoids, as a function of the macula in humans, of the quail retina by transmission electron microscopy in young, middle-aged, and old birds, and in middle-aged birds irradiated with blue LED light (450 nm, 4 J/cm2). It has been shown that during photo-oxidative stress caused by the action of blue light on the quail eye, active fusion of melanosomes and lipofuscin granules occurs with formation of various types, including giant, mixed melanolipofuscin-like granules. Increased accumulation of melanolipofuscin-like granules was also observed in non-irradiated old birds. It is assumed that the decrease in the number of melanosomes in the RPE during aging and photo-oxidative stress is associated with their fusion with lipofuscin granules and subsequent degradation of melanin by reactive oxygen species formed in melanolipofuscin-like granules. The disappearance of melanin deprives the RPE cells of light-filtering and antioxidant protection, and significantly increases the risk of their oxidative stress.

Assessment of the onset of analgesia and length of analgesia following the use of PBM with different wavelengths: a clinical study

This clinical study assessed photobiomodulation (PBM) induced analgesic effects of diode lasers and an LED light source on the dental pulp. Baseline responses to electric pulp testing (EPT) were recorded in 93 healthy unrestored premolar teeth in 26 adults (age range 22–63 years) attending a private dental practice. The teeth were irradiated on buccal and lingual aspects of the crown, by placing the tips on the middle third of the crown of the teeth, on separate days for each of 4 different light sources (660, 808, or 904 nm diode lasers, or a novel multi-wavelength LED light source (700–1100 nm)) using comparable parameters (100 mW, 30 s, 6 J). EPT scores were measured after a further 1-, 2-, 5- and 20-min. Discomfort caused by PBM therapy was recorded using the Wong-Baker scale. EPT changes were tracked over time using repeated measures analysis of variance. Baseline EPT scores were very consistent between different days (linear regression r2 0.9422–0.9648). All PBM devices caused a significant elevation in EPT at 5 min, with an earlier onset at 2 mins for 904 nm and LED. The LED was the only light source that elevated scores at 20 min. Across 2–20 min, when ranked by effectiveness, the greatest EPT elevations were seen for LED, followed by 904 nm, then 660 nm and finally 808 nm. Discomfort during PBM was most common with 904 nm, followed by 808 nm. No discomfort occurred from the LED. Among the light sources utilized, the LED multi-wavelength system demonstrated the largest increase in EPT readings, suggesting its potential as a non-pharmacological alternative for achieving dental analgesia compared to diode lasers.

Optimization of the Design of a Greenhouse LED Luminaire with Immersion Cooling

Modern agriculture, with the use of artificial lighting, requires high-intensity LED luminaires with compact dimensions. In this regard, new approaches to the design of LED luminaires using both new materials and technical solutions have been considered. The theoretical evaluation of the influence of different materials on the efficiency of removal of thermal energy from LEDs was shown. A new material PMS-5 is proposed and evaluated as an immersion liquid, which can be used as an effective heat sink in the lower part of the luminaire up to the level of LEDs located in the top light LED luminaires. The proposed polymethylsiloxane PMS-5 liquid has more than twice the thermal conductivity (0.167 W/(m·K)) of HFE7200 and NS15 liquids used in immersion-cooled LED luminaires. Based on the theoretical evaluation, the requirements for parameters, such as metal profile area, immersion liquid volume, wall thickness area, and external area of the cylinder, are highlighted and shown. The noted parameters have a key role in the design of an efficient top light LED luminaire. It has been shown that the design of the metal profile significantly affects the efficiency of the removal of thermal energy from LEDs and it is necessary to use specialized profiles optimized for the diameter of the LED luminaire cylinder. A number of LED luminaire designs were proposed, depending on the thermal properties of the construction materials, technical and economic performance, as well as actual operating and installation conditions. The analysis of the presented theoretical evaluations allowed overlay of the design basis of LED luminaires within the presented concept and top light.

ANALISIS PENGARUH HARGA, KUALITAS, DAN PROMOSI TERHADAP KEPUTUSAN PEMBELIAN YANG DIMEDIASI OLEH MINAT BELI LAMPU PANDAWA LED

This quantitative study aims to analyze the effect of price, quality, and promotion on purchasing decisions mediated by buying interest in Pandawa Led lamps. The population in this study were consumers of Pandawa LED lamps at the Gema Lawu Elektronik Plaosan store, from which data was taken in part with a Likert-scale questionnaire. The sampling technique in this study was non probability sampling with a purposive sampling approach. The data analysis technique used in this study is to use PLS-SEM analysis consisting of two Outer model and Inner model. The results showed that price, product quality and promotion had a positive and significant effect on purchasing decisions. Likewise, price, product quality and promotion have a positive and significant effect on purchase intention. The same results on the mediating variable can be explained that buying interest mediates the influence between price, product quality and promotion variables on purchasing decisions.

Stability and photophysical study of bright day light fluorescent material and its fabrication in laser patterning and LED application

Developing aggregation-induced emission (AIE) active highly visible fluorescent dyes is of great importance because of its numerous applications. We have successfully developed and synthesized two novel napthalimide based molecules PU1 and PU2, that exhibit bright greenish yellow in day light and vivid green emission when exposed to UV light. Compounds PU1 and PU2 exhibit variable emission behavior at different solvent polarities. Upon raising the solvent polarity from ether to DMF, emission maxima of PU1 and PU2 underwent a bathochromic shift. Additionally, compounds PU1 and PU2 show signs of AIE, which cause a restriction in intramolecular mobility. A distinct self-assembled structure was generated at 30 % aqueous DMF solution following aggregation, as demonstrated by experiments using dynamic light scattering and field emission scanning electron microscopy. Compounds PU1 and PU2 have been blended with poly(urethane) to develop a polymeric film. Tensile strain studies, and TGA, DSC analyses were used to examine the thermal/mechanical stability of PU films. The photostability of PU1 and PU2 in both solution and polymeric film was examined using a 5-h UV-beam irradiation. Furthermore, in the presence of trifluoroacetic acid, the blended polymeric film and 365 nm LED light coated material exhibits distinct colorimetric and fluorimetric transformations. Finally, laser-induced periodic surface structure (LIPSS) pattern processing on PU1 coated substrates can be extended for optical applications.

Designing a high-efficiency broadband cyan phosphor for low-blue full-spectrum LED lighting

Efficient cyan-emitting phosphor plays an important role in the development of solid-state lighting, which is indispensable to filling the cyan gap for full-spectrum warm-white light-emitting diodes (WLEDs) with high color rendering index (CRI). Herein, a novel highly efficient broadband cyan phosphor Ce3+-doped Ca3HfAl2Si2O12 (CHASO: Ce3+) garnet compound was developed by the substitution of Lu3+-Al3+ with Ca2+-Hf4+/Si4+ in Lu3Al5O12. The crystal structure and photoluminescence (PL) properties of CHASO: Ce3+ were investigated in detail. Notably, CHASO: Ce3+ phosphor can be effectively excited by violet light (390 – 430 nm) and exhibited bright cyan emissions around 490 nm with high PL internal quantum yields of 89.2 %. Moreover, the integrated PL intensity of the phosphor at 423 K was 66.3 % of that at room temperature. Finally, by incorporating CHASO: 11 %Ce3+ with commercial blue/yellow/red phosphor onto a violet LED chip (400 nm), the prototype full-spectrum WLEDs device exhibits warm white light with high color rendering index (CRI, Ra and R9 > 90) and low correlated color temperature 3301 K. These results suggest the highly efficient phosphor CHASO: Ce3+ is promising for low-blue full-spectrum healthy lighting.

Accurate Low Complexity Quadrature Angular Diversity Aperture Receiver for Visible Light Positioning.

Despite the many potential applications of an accurate indoor positioning system (IPS), no universal, readily available system exists. Much of the IPS research to date has been based on the use of radio transmitters as positioning beacons. Visible light positioning (VLP) instead uses LED lights as beacons. Either cameras or photodiodes (PDs) can be used as VLP receivers, and position estimates are usually based on either the angle of arrival (AOA) or the strength of the received signal. Research on the use of AOA with photodiode receivers has so far been limited by the lack of a suitable compact receiver. The quadrature angular diversity aperture receiver (QADA) can fill this gap. In this paper, we describe a new QADA design that uses only three readily available parts: a quadrant photodiode, a 3D-printed aperture, and a programmable system on a chip (PSoC). Extensive experimental results demonstrate that this design provides accurate AOA estimates within a room-sized test chamber. The flexibility and programmability of the PSoC mean that other sensors can be supported by the same PSoC. This has the potential to allow the AOA estimates from the QADA to be combined with information from other sensors to form future powerful sensor-fusion systems requiring only one beacon.

The Analysis Of Ultrasonic Sensors In Smart Trash Bin Technology Based On Arduino Nano Microcontroller

Waste is an environmental problem that is increasing along with population growth and public consumption. To solve this problem, an automatic device that controls the opening and closing of the trash can without direct touch is developed using an Arduino Nano microcontroller, HC-SR04 ultrasonic sensor, VL53L0X LIDAR, and MG996R servo motor. This research aims to evaluate the responsiveness of the sensor in detecting objects, the effect of the interaction of distance, angle, and object thickness on the sensor response time and aims to determine the effect of garbage volume on the response time of the indicator LED light. The test was conducted using the experimental method of distance variation of 20 cm, 30 cm, 40 cm, and 50 cm; angle variation of 0°, 10°, and 20°; and thickness variation of 10 mm, 65 mm, and 120 mm. Data analysis using multiple linear regression research methods shows a P-Value of 0.409 for the ultrasonic sensor with ɑ of 0.05, if the P-Value > ɑ, then H0 is accepted and H1 is rejected which mean that there is no significant effect of the interaction between distance, angle, and thickness of the object on the response time of the trash can lid opening sensor.

The impact of light adjustment versus tuneable white mode on ICU staff’s circadian rhythms

ABSTRACT The significance of lighting design in intensive care units (ICUs) for healthcare professionals’ demanding work and its profound impact on health, visual comfort and overall well-being cannot be overstated. This study investigates the potential of controlling luminous flux and spectral characteristics to enhance ICU lighting environments. It aims to determine whether modifying the lighting spectrum positively affects health without compromising visual comfort and colour discrimination. Two distinct LED lighting configurations were tested. The first adjusted only light levels, providing insights into staff responses. The second used tuneable white lighting, allowing changes in spectral content and colour temperature throughout shifts, resembling natural light variations. Effects were assessed via subjective perception surveys and objective colour rendering tests. Physiological impacts were evaluated through urine and blood samples, analysing melatonin suppression and cortisol levels, crucial for regulating rhythms and stress. Results offer valuable insights into lighting’s impact on ICU occupants’ well-being, highlighting the potential benefits of spectral adjustments while maintaining visual comfort and colour discrimination. This holistic approach to lighting design in critical care settings emphasizes the importance of balancing health benefits with lighting quality.

Modulation of Photosensitizing Responses in Cell Culture Environments by Different Medium Components.

Many cell culture experiments are performed under light to evaluate the photodynamic or photosensitizing efficacy of various agents. In this study, the modulation of photosensitizing responses and phototoxicity under cell culture conditions by different medium components was investigated. The significant levels of reactive oxygen species (ROS) generated from DMEM, RPMI 1640, and MEM were observed under the irradiation of fluorescent light (FL) and white and blue LEDs, indicating that these media have their own photosensitizing properties; DMEM showed the most potent property. Phenol red-free DMEM (Pf-D) exhibited a stronger photosensitizing property than normal DMEM by 1.31 and 1.25 times under FL and blue LEDs, respectively; phenol red and riboflavin-free DMEM (PRbf-D) did not show any photosensitizing properties. The inhibitory effect on light transmission was more pronounced in DMEM than in RPMI, and the interference effect on green LED light was greatest at 57.8 and 27.4%, respectively; the effect disappeared in Pf-D. The media containing riboflavin induced strong phototoxicity in HaCaT keratinocytes by generating H2O2 under light irradiation, which was quenched by sodium pyruvate in the media. The presence of serum in the media was also reduced the phototoxicity; H2O2 levels in the media decreased serum content dependently. The phototoxicity of erythrosine B and protoporphyrin IX under FL was more sensitively pronounced in PRbf-D than in DMEM. The present results indicate that several medium components, including riboflavin, phenol red, sodium pyruvate, and serum, could modulate photosensitizing responses in a cell culture system by inducing photosensitizing activation and by interfering with irradiation efficacy and ROS generation.

Novel Tm3+/Dy3+ co-doped CaMoO4 transparent glass-ceramic phosphor for white LED applications

To develop new inorganic luminescent materials, a set of Dy3+/Tm3+ co-doped molybdate precursor glasses (PGs) were manufactured using the conventional melting method, and a novel CaMoO4 transparent fluorescent glass-ceramic (GC700-2 h) was achieved via controlled crystallization of PG at 700 ℃ for 2 h. The luminescent color of the glass phosphor was facilely modulated by varying the doping levels of Dy3+ and Tm3+. The glass phosphor with optimal doping concentration of 0.6Dy3+ and 0.6Tm3+ exhibits a color coordinate of (0.3334, 0.3107). Compared with PG, the luminous intensity and quantum yield of GC700-2 h sample is obviously increased, and GC720-2 h sample displays the color coordinate (0.3292, 0.2852), belonging to the standard white light region. Moreover, GC720-2 h sample possesses good thermal stability in fluorescence property. The white LED lamp encapsulated with GC720-2 h exhibits color temperature of 7564 K and color rendering index of 75.3. These results clearly show that the 0.6Dy3+/0.6Tm3+ co-doped glass and CaMoO4 glass-ceramic could be used as potential candidate material in the field of white light-emitting diodes.

Light sensitivity of the circadian system in the social Highveld mole-rat Cryptomys hottentotus pretoriae.

Highveld mole-rats (Cryptomys hottentotus pretoriae) are social rodents that inhabit networks of subterranean tunnels. In their natural environment, they are rarely exposed to light, and consequently their visual systems have regressed over evolutionary time. However, in the laboratory they display nocturnal activity, suggesting that they are sensitive to changes in ambient illumination. We examined the robustness of the Highveld mole-rat circadian system by assessing its locomotor activity under decreasing light intensities. Mole-rats were subjected to seven consecutive light cycles commencing with a control cycle (overhead fluorescent lighting at 150lx), followed by decreasing LED lighting (500, 300, 100, 10 and 1lx) on a 12h light:12h dark (L:D) photoperiod and finally a constant darkness (DD) cycle. Mole-rats displayed nocturnal activity under the whole range of experimental lighting conditions, with a distinct spike in activity at the end of the dark phase in all cycles. The mole-rats were least active during the control cycle under fluorescent light, locomotor activity increased steadily with decreasing LED light intensities, and the highest activity was exhibited when the light was completely removed. In constant darkness, mole-rats displayed free-running rhythms with periods (τ) ranging from 23.77 to 24.38 h, but was overall very close to 24 h at 24.07 h. Our findings confirm that the Highveld mole-rat has a higher threshold for light compared with aboveground dwelling rodents, which is congruent with previous neurological findings, and has implications for behavioural rhythms.

The role of spectral matching in enhancing photocatalytic performance with TiO2-rGO catalysts for metronidazole wastewater elimination

The role of spectral matching in enhancing the photocatalytic degradation of metronidazole using TiO2-reduced graphene oxide (TiO2-rGO) systems is investigated in this study. A rapid, one-step microwave synthesis method was utilized to produce TiO2-rGO composites with varying proportions of graphene oxide. Characterization techniques, including X-ray diffraction (XRD), Raman spectroscopy, and transmission electron microscopy (TEM), were employed to elucidate the morphological and structural attributes of the photocatalysts, thereby facilitating their application in photocatalysis. Spectral matching between the photocatalytic material and the irradiation source was identified as critical to the methodology. Experiments conducted under LED light tailored to the absorption spectra of the catalysts demonstrated that the TiO2-rGO system with a 2 % GO composition achieved the highest metronidazole degradation efficiency, reaching 95 % degradation after 120 min of irradiation. Furthermore, the catalyst maintained high reusability, with only a 5 % decrease in efficiency after five cycles of reuse. The Electrical Energy per Order (EEO) was determined to be 3.51 kWh/m3, indicating the system’s high energy efficiency. The study emphasizes the real-world applicability of TiO2-rGO composites for wastewater treatment, particularly in terms of environmental sustainability and operational cost-effectiveness.

Scrutiny of pseudoplastic nanofluid flow under the influence of magnetic hydrodynamics with chemical reaction across the cylinder with slip boundary condition

Buoyantly induced flows possess diversified utilizations in numerous engineering processes for instance, reactor cooling through passive strategy, LED lights, pipes manufacturing, ship funnel and many more. Galvanized sheets sticked to form a hollow cylinder is used for fast cooling in naval ship and chimney of steam power plant. In view of such mesmerizing significance of flow and thermal attributes of fluid over vertical cylinder, current effort is articulated. For this purpose, Williamson fluid model is accounted and nanoparticles are also induced to envision advanced thermal features in the flow over vertically oriented cylinder. Physical effectiveness of magnetic field implications and chemical reactive species are entertained to notice change in hydrothermal and mass fields. Slip boundary constraint along with stagnant flow at the surface of cylinder is considered to inspect behavior in free stream region. The fundamental governing equations of problem are attained in the sense of PDEs by utilizing the concept of boundary layer approximation and converted into coupled nonlinear ODEs by substituting specific similar variables. Numerically the resulting ODEs are resolved by making the use of bvp4c built in MATLAB routine, the outcomes are attained and arranged in graphical and tabular manner. The influence of pertinent flow parameters such as (0.1 ≤ We ≤ 1.0), (1.0 ≤ M ≤ 3.0), (1.0 ≤ Pr ≤ 11), thermophoresis parameter (0.5 ≤ Tp ≤ 4.5), (1.0 ≤ Bp ≤ 5.0), (0.05 ≤ Nr ≤ 0.7), and (0.5 ≤ Kc ≤ 5.0) are examined on the momentum, thermal and concentration distributions. It is manifested that the velocity distribution depreciates by uplifting magnetic field strength. Increment in magnitude of wall drag and convective heat transfer is perceived by enhancing Prandtl number. It is inferred that friction coefficient in absolute sense and heat flux coefficient tends to exceed against elevation in (We). From comprehensive analysis, declination in velocity and thermal field is depicted versus Reynold number whereas, contrary aspects are visualized in concentration. Enhancement in the value of surface drag and thermal flux is revealed versus (Re).

Bioactivity of Amphidinol-Containing Extracts of Amphidinium carterae Grown Under Varying Cultivation Conditions.

Microalgae are of great interest due to their ability to produce valuable compounds, such as pigments, omega-3 fatty acids, antioxidants, and antimicrobials. The dinoflagellate genus Amphidinium is particularly notable for its amphidinol-like compounds, which exhibit antibacterial and antifungal properties. This study utilized a two-stage cultivation method to grow Amphidinium carterae CCAP 1102/8 under varying conditions, such as blue LED light, increased salinity, and the addition of sodium carbonate or hydrogen peroxide. After cultivation, the biomass was extracted and fractionated using solid-phase extraction, yielding six fractions per treatment. These fractions were analyzed using Liquid Chromatography-High-Resolution Mass Spectrometry (LC-HRMS/MS) to identify their chemical components. Key amphidinol compounds (AM-B, AM-C, AM-22, and AM-A) were identified, with AM-B being the most abundant in Fraction 4, followed by AM-C. Fraction 5 also contained a significant amount of AM-C along with an unknown compound. Fraction 4 returned the highest antimicrobial activity against the pathogens Staphylococcus aureus, Enterococcus faecalis, and Candida albicans, with Minimal Biocidal Concentrations (MBCs) ranging from 1 to 512µg/mL. Results indicate that the modulation of both amphidinol profile and fraction bioactivity can be induced by adjusting the cultivation parameters used to grow two-stage batch cultures of A. carterae.

Synthesis and Spectroscopic Study of a Homogenous Bimetallic Os(II) Complex as a New Gastric Cancer Photosensitizer.

A homogenous dinuclear Os(II) complex bisOs was synthesized and fully characterized. The electrochemical cyclic voltammetry study, and density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations were performed to investigate the electronic property. bisOs showed an obvious interaction with lipase and BSA, and can generate singlet oxygen under blue and red LED light irradiation, with a singlet oxygen quantum yield (ФΔ) of 0.36 in comparison to that of [Ru(bpy)3]Cl2 in acetonitrile. bisOs exhibited moderate to great photocytotoxicity against HGC-27 human gastric cancer cells under blue LED light irradiation, giving the IC50 value as low as 1.83 µM (PI value is 9.7), while was almost non-cytotoxic in the dark. The cellular singlet oxygen detection in HGC-27 cancer cells exhibited a concentration-dependent manner, and cell uptake of bisOs in A549 cells was as high as 120 ng/106 cells, subcellular colocalization study indicated that bisOs was not accumulated in nucleus, and less likely to target mitochondria. This work provides a new example of dinuclear osmium complex as potential photosensitizer candidate for gastric treatment.

Low-Cost, High-Efficiency Aluminum Zinc Oxide Synaptic Transistors: Blue LED Stimulation for Enhanced Neuromorphic Computing Applications.

Neuromorphic devices are electronic devices that mimic the information processing methods of neurons and synapses, enabling them to perform multiple tasks simultaneously with low power consumption and exhibit learning ability. However, their large-scale production and efficient operation remain a challenge. Herein, we fabricated an aluminum-doped zinc oxide (AZO) synaptic transistor via solution-based spin-coating. The transistor is characterized by low production costs and high performance. It demonstrates high responsiveness under UV laser illumination. In addition, it exhibits effective synaptic behaviors under blue LED illumination, indicating high-efficiency operation. The paired-pulse facilitation (PPF) index measured from optical stimulus modulation was 179.6%, indicating strong synaptic connectivity and effective neural communication and processing. Furthermore, by modulating the blue LED light pulse frequency, an excitatory postsynaptic current gain of 4.3 was achieved, demonstrating efficient neuromorphic functionality. This study shows that AZO synaptic transistors are promising candidates for artificial synaptic devices.

Investigating the influence of varied ratios of red and far-red light on lettuce (Lactuca sativa): effects on growth, photosynthetic characteristics and chlorophyll fluorescence.

Far red photon flux accelerates photosynthetic electron transfer rates through photosynthetic pigments, influencing various biological processes. In this study, we investigated the impact of differing red and far-red light ratios on plant growth using LED lamps with different wavelengths and Ca1.8Mg1.2Al2Ge3O12:0.03Cr3+ phosphor materials. The control group (CK) consisted of a plant growth special lamp with 450 nm blue light + 650 nm red light. Four treatments were established: F1 (650 nm red light), F2 (CK + 730 nm far-red light in a 3:2 ratio), F3 (650 nm red light + 730 nm far-red light in a 3:2 ratio), and F4 (CK + phosphor-converted far-red LED in a 3:2 ratio). The study assessed changes in red and far-red light ratios and their impact on the growth morphology, photosynthetic characteristics, fluorescence characteristics, stomatal status, and nutritional quality of cream lettuce. The results revealed that the F3 light treatment exhibited superior growth characteristics and quality compared to the CK treatment. Notably, leaf area, aboveground fresh weight, vitamin C content, and total soluble sugar significantly increased. Additionally, the addition of far-red light resulted in an increase in stomatal density and size, and the F3 treatments were accompanied by increases in net photosynthetic rate (Pn), transpiration rate (Tr), intercellular CO2 concentration (Ci), and stomatal conductance (Gs). The results demonstrated that the F3 treatment, with its optimal red-to-far-red light ratio, promoted plant growth and photosynthetic characteristics. This indicates its suitability for supplementing artificial light sources in plant factories and greenhouses.

Assessment of the carbon footprint of total hip arthroplasty and opportunities for emission reduction in a UK hospital setting.

This study aimed to assess the carbon footprint associated with total hip arthroplasty (THA) in a UK hospital setting, considering various components within the operating theatre. The primary objective was to identify actionable areas for reducing carbon emissions and promoting sustainable orthopaedic practices. Using a life-cycle assessment approach, we conducted a prospective study on ten cemented and ten hybrid THA cases, evaluating carbon emissions from anaesthetic room to recovery. Scope 1 and scope 2 emissions were considered, focusing on direct emissions and energy consumption. Data included detailed assessments of consumables, waste generation, and energy use during surgeries. The carbon footprint of an uncemented THA was estimated at 100.02 kg CO2e, with a marginal increase to 104.89 kg CO2e for hybrid THA. Key contributors were consumables in the operating theatre (21%), waste generation (22%), and scope 2 emissions (38%). The study identified opportunities for reducing emissions, including instrument rationalization, transitioning to LED lighting, and improving waste-recycling practices. This study sheds light on the substantial carbon footprint associated with THA. Actionable strategies for reducing emissions were identified, emphasizing the need for sustainable practices in orthopaedic surgery. The findings prompt a critical discussion on the environmental impact of single-use versus reusable items in the operating theatre, challenging traditional norms to make more environmentally responsible choices.