Red Light Group Research Articles

Histological Characteristics of Follicles, Reproductive Hormones and Transcriptomic Analysis of White King Pigeon Illuminated with Red Light.

Red light (RL) has been observed to enhance egg production in pigeons, yet the underlying histological characteristics and molecular mechanisms remain less understood. This study included fifty-four pigeons to assess follicular histology, reproductive hormones, and ovarian transcriptomics on the third day of the laying interval under RL and white light (WL). The results showed that the granulosa cell layer was significantly thicker under RL (p < 0.05), whereas the theca cell and connective tissue layers showed no significant differences (p > 0.05). Higher plasma estradiol (E2) levels were recorded in the RL group (p < 0.05), as well as follicle stimulating hormone (FSH), although progesterone (P4) levels were higher under WL (p < 0.05). Moreover, P4 concentrations in follicle yolk significantly decreased under RL (p < 0.01), with higher FSH and E2 levels in F1 yolk and similar increases in SF1 yolk (p < 0.01). Transcriptomic analysis revealed 4991 differentially expressed genes in the pigeon ovary. The protein-protein interaction network highlighted genes like HSD11B1, VEGFD, WNT6, SMAD6, and LGR5 as potential contributors to hierarchical follicle selection under RL. This research provides new insights into the molecular basis by which RL may promote hierarchical follicle selection and improve egg production in pigeons.

Research Note: Effects of different light-emitting diode lights during egg incubation on hatching performance and embryo development in White King pigeons

The light provide during incubation can influence hatching characteristics (hatching time, hatchability, etc.) and embryo development in chickens, geese, and turkeys. However, relevant studies on this factor in pigeons are lacking. This study investigated the effects of in ovo photostimulation during embryogenesis on hatching performance, squab quality, and embryo development in pigeons. 400 eggs from paired- bred pigeons were randomly distributed into 4 incubation lighting treatments, with 2 replicates per treatment. The treatments included dark as a control (NL), 12-h light, and 12-h dark photoperiods of white light (WL), red light (RL), and green light (GL) (100 lx at egg level) during the first 15 d of incubation. A total of 1,600 eggs in 4 batches from White King pigeons were used. The results showed that hatching time of the WL group was significantly shorter than that of the dark light group (P < 0.05). The hatchability of fertile eggs in the WL group was significantly higher (P < 0.05), whereas the hatchability of fertile eggs in the RL group was significantly lower (P < 0.05) than that of in the control group. Light stimulation had no effect on time to 90% hatching or average hatching time (P > 0.05). In addition, the hatch window was not extended by light stimulation (P > 0.05). The group incubated under GL showed an increase in embryo weight and relative leg muscle on embryonic d 14 and the hatching day compared to the dark incubation (P < 0.05). Green light stimulated the heart and liver development during the early and middle stages of embryogenesis. It was concluded that white light stimulation during embryogenesis accelerated the hatching process, whereas monochromatic green light had a positive effect on embryo development. Our findings provide important guidance for developing light protocols for pigeon egg incubation.

CircRNAs involved in the red light of effect on follicle selection in pigeons

Red light (RL) can enhance egg production in poultry. CircRNAs play a crucial role by serving as transcriptional regulators. However, their role in influencing follicle development in White King pigeons remains unexplored. In this study, 54 paired White King pigeons were chosen and divided into RL and white light (WL) groups, each with 3 subgroups. The egg production of paired pigeons in each replicate was recorded for 45 d, and the characteristics of follicle development were monitored during the laying interval (LI). The granulosa cell layer from follicles of the second-largest follicle (F2) was collected, and high-throughput sequencing was performed to elucidate the molecular mechanism of follicle development in pigeons. The study confirmed that RL enhances egg production in pigeons. Additionally, under RL, the F2 follicle was selected, while under WL, small follicles were kept on the third day (LI3). A total of 5,510 circRNAs were identified across all samples, revealing differentially expressed circRNAs (DECs) in various comparisons: 627 in RF1 vs. WF1, 900 in RF2 vs. WF2, 606 in RF1 vs. RF2, and 937 in WF1 vs. WF2. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis indicated that host genes of DECs were enriched in pathways like steroid hormone biosynthesis, oocyte meiosis, GnRH signaling pathway, and apoptosis pathway. Moreover, circRNA_5497, circRNA_2016, and circRNA_3328 were common DECs across 4 groups, sharing miRNA binding sites with follicle selection-associated genes. In conclusion, our findings suggest that RL promotes egg production by stimulating follicle selection during LI, offering insights into the regulatory mechanisms of circRNAs in follicle selection under RL. This knowledge can help enhance the reproductive performance of pigeons.

Effects of Light Spectrum on Survival, Growth, Physiological, and Biochemical Indices of Redclaw Crayfish (Cherax quadricarinatus) Juveniles

The spectrum is a key environmental factor, and light-emitting diodes (LEDs) can influence the growth and development of crustaceans by altering the composition of the spectrum. This study conducted a 30-day experiment to investigate the effects of five LED spectra (red, yellow, blue, green, and white light) on the growth, antioxidant and immune enzyme activities, stress hormone levels, and the expression of α-amylase (α-AMY), ecdysone receptor (EcR) and retinoid X receptor (RXR) genes in juvenile redclaw crayfish (Cherax quadricarinatus). The results show that the survival rate of juveniles is markedly higher in the yellow and red-light groups than in the other three groups (P&lt;0.05). The green light group exhibits the lowest survival rate, yet it demonstrates the highest weight gain rate and specific growth rate. Regarding enzyme activity and hormone levels, the yellow light group shows the lowest malondialdehyde content, with higher superoxide dismutase and acid phosphatase activity than the other groups; no significant differences are observed in lysozyme activity among the groups (P&gt;0.05). The melatonin content in the green and blue light groups is significantly higher than that in the other three groups (P&lt;0.01). In terms of growth gene expression, the expression of α-AMY, EcR, and RXR in juvenile C. quadricarinatus is regulated by the spectrum. In conclusion, when raised under the yellow light spectrum, juvenile C. quadricarinatus displays elevated survival rates, rapid growth, and robust antioxidant and immune defenses. This study provides important technical parameters for optimizing and enhancing the industrial cultivation of juvenile C. quadricarinatus.

Effects of Light Color on the Growth, Feeding, Digestion, and Antioxidant Enzymes of Tripneustes gratilla (Linnaeus, 1758).

To study the effects of light color on sea urchin (Tripneustes gratilla), blue light (B, λ450nm), yellow light (Y, λ585-590nm), red light (R, λ640nm), green light (G, λ510nm), white light (W, λ400-780nm), and darkness (H) groups were established in a recirculating seawater aquaculture system. Six different LED light color treatment groups with a photoperiod of 12 L:12 D were tested for 30 days to investigate the effects of different light colors on the feeding, growth, and enzyme activities of T. gratilla (142.45 ± 4.36 g). We found that using different LED light colors caused significantly different impacts on the feeding, growth, and enzyme activity of T. gratilla. Notably, the sea urchins in group B exhibited better growth, with a weight gain rate of 39.26%, while those in group R demonstrated poorer growth, with a weight gain rate of only 26%. The feeding status differed significantly (p < 0.05) between groups B and R, with group B consuming the highest daily intake (6.03 ± 1.69 g) and group R consuming the lowest (4.54 ± 1.26 g). Throughout the three phases, there was no significant change in the viability of the α-amylase (p > 0.05). Conversely, the pepsin viability significantly increased (p < 0.05) in group B. The lipase viability consistently remained at the lowest level, with no notable differences between group W and group B. In group R, both the α-amylase and pepsin viabilities remained lower, whereas the lipase viability was noticeably greater in each phase than in group B (p < 0.05). Among the antioxidant enzymes, group R exhibited a trend of initial increase followed by decreases in catalase, superoxide dismutase, and glutathione peroxidase activities, particularly during the third stage (15-30 days), during which a significant decrease in antioxidant enzyme activity was observed (p < 0.05). Taken together, these findings suggest that blue light positively affects the growth, feeding, digestion, and antioxidant capacity of T. gratilla in comparison with those in other light environments, whereas red light had an inhibitory effect. Furthermore, T. gratilla is a benthic organism that lives on shallow sandy sea beds. Thus, as short wavelengths of blue and green light are more widely distributed on the seafloor, and long wavelengths of red light are more severely attenuated on the seafloor, shorter wavelengths of light promote the growth of bait organisms of sea urchins, which provide better habitats for T. gratilla.

Low-energy LED red light inhibits the NF-κB pathway and promotes hPDLSCs proliferation and osteogenesis in a TNF-α environment in vitro.

There are few studies on the effect of low-energy LED red light on periodontal tissue regeneration in an inflammatory environment. In this study, Cell Counting Kit-8(CCK-8) assays were used to detect the effects of TNF-α at three different concentrations (0, 10ng/ml, and 20ng/ml) on the proliferation of human periodontal ligament stem cells (hPDLSCs), and 10ng/ml was selected as the subsequent experimental stimulation concentration. CCK-8 assays were used to detect the effect of LED red light with energy density of 1J/ cm2, 3J/ cm2, and 5J/cm2 on the proliferation of hPDLSCs. The promotion effect of energy density of 5J/cm2 on the proliferation of hPDLSCS was the most obvious (p < 0.05). Set CON group, ODM group, ODM + 10ng/ml TNF-α group, and ODM + 10ng/ml TNF-α + 5J/ cm2 LED red light group. Alkaline phosphatase staining and activity detection, alizarin red staining and calcium nodules quantitative detection of osteoblast differentiation products, real-time fluorescence quantitative PCR detection of osteoblast gene expression (Runx2, Col-I, OPN, OCN). The results showed that ODM showed the strongest osteoblast ability, followed by ODM + 10ng/ml TNF-α + 5J/ cm2 LED red light group. The osteoblast ability of ODM + 10ng/ml TNF-α was decreased, but was not found in CON group. Western blot was used to detect the expression of NF-κB pathway protein and osteoblast-related proteins (Runx2, Col-I, OPN, OCN) after addition of PDTC inhibitor. The results showed that the expression of p-IκBα was increased and the expression of IκBα was decreased (p < 0.05). The expression of osteoblast protein increased after the addition of inhibitor (p < 0.05). Therefore, in an inflammatory environment constructed by 10ng/ml TNF-α, 5J/cm2 LED red light can upregulate the proliferation and osteogenesis of hPDLSCs by inhibiting NF-κB signaling pathway.

Effects of monochromatic light on hepatic glycogen and lipid synthesis in broilers

Animal growth is closely related to glycolipid metabolism, and the liver is the main organ for glycogen storage and fat synthesis in birds, but whether monochromatic light affects glycogen and lipid synthesis in the liver is unclear. Therefore, in this study, a total of 96 Arbor Acre (AA) broilers at posthatching d 0 (P0) were raised under 4 kinds of light-emitting diode (LED) lights, white light (WL), red light (RL), green light (GL), and blue light (BL), to posthatching d 21 (P21) and 35 (P35). The results showed that the liver, abdominal fat, and abdominal fat indices gradually increased with increasing age under monochromatic light treatments. The liver glycogen and triglyceride (TG) contents also showed an increasing trend. Furthermore, compared with those at P21, the mRNA levels of glycogen synthase (GS), glycogen synthase kinase-3β (GSK-3β), and protein kinase B (AKT1) in the liver were increased in the WL and RL groups at P35, and the mRNA levels of acetyl-CoA carboxylase (ACC) and apolipoprotein B (APOB) increased in all groups at P35. At the same time, the total antioxidant capacity (T-AOC) and liver superoxide dismutase (SOD) contents increased in all groups at P35 compared with those at P21. In addition, at P21, compared with WL, GL and BL promoted the serum glucose (GLU) and TG contents by increasing the mRNA levels of GS, GSK-3β, glucose-6-phosphatase (G6PC), ACC, and fatty acid synthase (FAS), but no effect on the proliferative ability and damage of hepatocytes. At P35, RL promoted the hepatic glycogen and TG contents by increasing GSK-3β, AKT1, ACC, and APOB mRNA levels, and the serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were increased than in the WL group. These results suggest that the effects of light color on liver glycogen and lipid synthesis in broilers changed with age, and also provide a theoretical guidance for scientific use of color of light information to improve productive performance in broilers.

Effects of light quality and intensity on the juvenile physiological metabolism of Babylonia areolata

Babylonia areolata lives in bottom sediments during the day and emerges at night to forage. This study examined how different light qualities (blue, white, green, and red light) and intensities (0 and 2–32 μmol·m s−1) influence the growth and physiological activity of B. areolate juveniles. Changes in the activity of digestive enzymes, such as pepsin (PPS), lipase (LPS), and amylase (AMS), as well as energy metabolic enzymes, such as hexokinase (HK), pyruvate kinase (PK), lactic dehydrogenase (LDH) and succinic dehydrogenase (SDH), were also studied. The result showed that juveniles exhibited substantial variations under different light conditions. Specifically, the maximum bodyweight specific growth rates (SGR) under green, blue, red, and white light conditions were 3.56 ± 0.45 %·d−1, 3.03 ± 0.68 %·d−1, 3.01 ± 0.72 %·d−1 and 2.99 ± 0.73 %·d−1 at light intensities of 2 μmol·m−2·s−1, 4 μmol·m−2·s−1, 8 μmol·m−2·s−1 and 2 μmol·m−2·s−1, respectively. The shell length SGR, shell width SGR and body weight SGR in the dark group were not statistically different from those in the red light group at 2 μmol·m−2·s−1 (p > 0.05), while the body weight SGR of the dark group was significantly lower than that in other groups (p < 0.05). At the light intensity of 2 μmol·m−2·s−1, the activity of PPS in green and blue light was significantly higher than in red light (p < 0.05). The activity of HK in green light was considerably higher than that in darkness (p < 0.05), and there was no significant difference in the activity of LDH between the dark group and the red light group (p > 0.05), although the results of both groups were significantly higher than those of the blue and white light (p < 0.05). In addition, the activity of PPS, AMS, HK, PK, and LDH was considerably higher in darkness than in other light qualities (p < 0.05). Under different light qualities, the activity of all enzymes at the low light intensity was significantly higher than that at the high light intensity (p < 0.05), which coincided with growth characteristics. Therefore, blue and green light promoted the growth of juveniles at low light intensity (2 μmol·m−2·s−1), but darkness inhibited their growth. The findings of this study could be used as a foundation for optimizing lighting conditions and figuring out the optimum conditions for the growth and survival of B. areolata. Furthermore, this study could help explain how to control lighting conditions in real-world breeding situations.

Illumination of different light wavelengths on growth performance and physiological response of juvenile sweetfish, Plecoglossus altivelis

Light-emitting diodes (LEDs) have gained increasing popularity in fish farming because certain wavelengths of light may promote the growth and innate immune system of fish. In this study, we reported the effects of different LED wavelengths on growth performance, antioxidant defense, and innate immune responses in sweetfish. According to the results, the blue-light group showed significantly increased body weight and length after 12 weeks. In contrast, the red-light group showed significantly inhibited growth performance and decreased feeding motivation. There was no difference in survival rate among the groups during the 12-week experiment. The antioxidant defense analysis results showed that red light may cause increased splenic oxidative stress. Splenic tnf-α mRNA expression increased in the blue-light group at weeks 4, 8, and 12; however, in the red-light group, this increase was significant only at week 12. il-1β mRNA level increased at week 4 in both groups. The lysozyme mRNA expression was downregulated in the blue-light group after 4 weeks, but it decreased only at week 12 in the red-light group. Histological sections of the ovary in the blue-light group showed a higher synchronization of oocyte development compared with the red-light group. In summary, light wavelength in a captivity environment can influence the physiological response of sweetfish. This study thus demonstrated that blue LED has a positive effect on fish growth performance, antioxidant ability, innate immunity, and reproduction.

Effects of light on growth, feeding rate, digestion, and antioxidation in juvenile razor clams Sinonovacula constricta

In the present study, we explored the effects of seven light treatments (white, violet, blue, cyan, green, yellow, and red) on juvenile Sinonovacula constricta (length, 693.79 ± 82.91 μm), employing dark treatment as a control. A rearing experiment was conducted for one week in which the feeding rate was examined daily, e.g., one, two and three h after feeding. At the conclusion of the experiment, overall growth was calculated, and enzymatic activity related to digestion, superoxide dismutase, catalase, and glutathione peroxidase pertaining to antioxidant biomarkers, as well as expression levels of genes related to antioxidation and stress response, were examined. The results showed that the highest growth rates were observed in the yellow light group, while the lowest growth rates were found in the violet and blue light groups; on the other hand, no significant differences were found among the other groups. Meanwhile, when exposed to white, yellow, or green light, juveniles exhibited high feeding rates, while those in the violet and blue light groups showed low feeding rates. Regarding enzymatic activity related to digestion, those of α-amylase, lipase, pepsin, and trypsin were relatively higher in the yellow light group than in the other groups. Regarding oxidative stress, the yellow light group showed higher superoxide dismutase, catalase, and glutathione peroxidase activities than the other groups. In contrast, the lowest malonaldehyde level was found in the white light group, followed by yellow light, while there were no significant differences among the other groups. In addition, the expression levels of genes related to antioxidation and stress response (heat shock protein 70 and glucose-regulated protein 78) in juveniles generally exhibited higher levels in the red light group, whereas they showed relatively lower levels in the yellow light group. Collectively, these results suggest that the application of yellow light may facilitate the growth of juvenile S. constricta, while red and violet light have opposite effects.

Effects of Different LED Light Spectra on Growth and Immunity of the Japanese Eel (Anguilla japonica) and Giant Mottled Eel (A. marmorata).

Indoor recirculating aquaculture systems make light control possible and enable the usage of specific coloured lights to promote the growth and immunity of aquaculture species. Five different LED wavelengths (white light [460 nm], red light [622 nm], green light [517 nm], blue light [467 nm], and the dark) were used in this study to evaluate growth and immunity in the glass eel stage of two high-valued anguillid species, Japanese eel (Anguilla japonica) and giant mottled eel (A. marmorata). There were no significant differences in growth of the Japanese eel among the groups after 12 weeks of feeding (p > 0.05); the survival rate of each group was over 95%. The giant mottled eel showed better growth in total length and body weight in the red light and dark groups (p < 0.05). Expression levels of immune-related genes were not significantly different between each group of the Japanese eel and the giant mottled eel (p > 0.05). The growth of the Japanese glass eel was not significantly sensitive to different LED wavelengths, while the giant mottled glass eel showed better growth under red light and dark environments. Neither eel species showed significant differences in innate immunity under different LED wavelengths.

Effects of light color, photoperiod, and growth-related gene interference or overexpression on the survival, growth, or physiological and biochemical indices of red claw crayfish juveniles

To determine the optimal light color and photoperiod conditions for red claw crayfish juveniles, we studied the effects of these factors on their survival, growth, monoamine content, antioxidant capacity, nonspecific immune index, and the expression of EcR and α-AMY genes. Experiments involving five light color groups (red, green, blue, yellow, and white light), five photoperiod groups (0 L:24D, 6 L:18D, 12 L:12D, 18 L:6D, and 24 L:0D), besides, we also studied the effects of interference and overexpression of these genes on growth, survival, and their expression. (1) The red light group showed the highest survival rate, while the blue light group showed the fastest growth rate. Further, the red light group showed significantly higher superoxide dismutase [SOD], acid phosphatase [ACP], and alkaline phosphatase [AKP] activities, but significantly lower malondialdehyde [MDA], serotonin [5-HT], noradrenaline [NE], and dopamine [DA] concentrations. The yellow light group presented significantly higher SOD activity, and lower DA concentration. The blue light group showed the highest α-AMY expression level, while the EcR expression levels corresponding to the yellow and red light groups were significantly higher. (2) The 0 L:24D and 6 L:18D photoperiod groups showed significantly higher survival rates than the 24 L:0D group. Additionally, the SOD and ACP activities corresponding to the 6 L:18D and 0 L:24D group were significantly higher, while its MDA and DA concentrations were significantly lower. (3) The 6 L:18D, 12 L:12D, and 0 L:24D groups showed significantly higher α-AMY expression levels, while EcR expression was significantly higher in the 6 L:18D and 0 L:24D groups. (4) EcR or α-AMY gene interference or overexpression had no significant effect on juvenile crayfish survival. However, interfering with ECR expression reduced juvenile growth rate, while ECR or α-AMY gene overexpression enhanced their growth rate. Overall, red claw crayfish juveniles showed higher survival rates, greater antioxidant and immune activities, and lower monoamine contents under red light, 6 L:18D or 0 L:24D conditions. Thus, these conditions possibly improved digestion and absorption and also promoted molting in the juveniles. Additionally, ECR and α-AMY expression could reflect the growth rate of the juveniles, but not their survival.

Comparison of red light and blue light therapies for mild-to-moderate acne vulgaris: A randomized controlled clinical study.

Red and blue light therapies are safe and effective treatments for mild-to-moderate acne vulgaris. However, very few previous studies have directly compared the characteristics of these two methods. To compare the efficacy and side effects of red light (RL) and blue light (BL) for acne vulgaris and to assess these two therapies in different types of lesions. A total of 28subjects with mild-to-moderate acne vulgaris were randomized into the RL group or the BL group. Subjects in each group received different light treatments, and they were followed up regularly until 2weeks after the last treatment. The improvement rates of different types of acne lesions were compared between the 2groups, as well as the incidence of adverse reactions. At the 2-week follow-up, the average improvement rate of total acne lesions was 36.2% in the RL group and 30.7% in the BL group (p>.05). The average improvement rate of inflammatory and non-inflammatory lesions was 51.5% and 17.3% in the RL group, compared with 26.4% and 10.0% in the BL group (all p>.05). Treatment-related adverse reactions were observed distinctly in the BL group. Red light and BL therapies have similar efficacy in mild-to-moderate acne vulgaris, especially for inflammatory lesions. RL had advantages with fewer adverse reactions compared with BL.

CircRNA expression in chicken granulosa cells illuminated with red light

Red light (RL) can improve egg production in Jinghai Yellow hens. Circular RNAs (circRNAs) are novel, non-coding RNAs, but the molecular mechanism underlying circRNA function during follicular development in hens under monochromatic light has not been established. Herein, we compared expression profiles of granulosa cells (GCs) from small yellow follicles (SYFs) from hens under RL and white light (WL). A total of 2,468 circRNAs were identified, of which 22 were differentially expressed (DE) in the RL and WL groups. DE circRNA host genes were enriched in ovarian steroidogenesis, and MAPK and PI3K-Akt signaling pathways. Furthermore, DE circRNA_0320 and circRNA_0185 interacted with miR-143-3p, which targets the follicle-stimulating hormone receptor and is essential for GC differentiation and follicle development. These findings will facilitate further analysis of the molecular mechanism leading to GC development in hens raised under monochromatic light, which could lead to increased egg production.

Effects of different LED light colors on growth performance and harmful gas emission of broilers breeding in a digital rearing chamber

Refined management is an inevitable trend in the development of livestock husbandry. Accurate acquisition of breeding environment parameters is beneficial to improve breeding efficiency while reducing the environmental pollution. Light is an important breeding environmental factor during broiler breeding. In this study, a short-term broiler breeding experiment was conducted with different light color illumination environments in a digital breeding chamber under lab conditions. According to experimental results, the Red Light (RL) group was conducive to the growth of broilers at 30 d of age with low NH3 emission concentration; the Green Light (GL) group inhibited the broiler growth; the Yellow Light (YL) group showed the highest average emission concentration of NH3 and lowest daily average emission concentration of CO2. According to the analysis of moisture content, pH value, and C/N in the broiler manure, it can be concluded that the physical and chemical properties of broiler defecation quantities were different under various light color illuminations, resulting in the difference in broiler growth conditions and harmful gas emissions. The study results could provide a research basis and ideas of reference to establish a relationship between LED illumination information, broiler growth performance, and harmful gas emission. Keywords: broiler, growth properties, harmful gas, ammonia, illumination environment DOI: 10.25165/j.ijabe.20221504.6766 Citation: Jie D F, Zhang Z X, He J C, Zhou Y F, Zhu G Y. Effects of different LED light colors on growth performance and harmful gas emission of broilers breeding in a digital rearing chamber. Int J Agric & Biol Eng, 2022; 15(4): 71–78.

The Effects of Monochromatic Lighting on Hatch Window and Hatching Performance in Broiler Breeder Eggs

In this study, the effects of monochromatic lighting on egg weight loss, embryonic mortality, hatch window and hatching performance were investigated. The number of eggs used in the experiment was a total of 780 (Ross-308 genotype). Eggs were randomly assigned to 3 groups. 1) Control group: Eggs were incubated in dark, 2) Green light group: 560 nm (wavelength from 535 to 585 nm), 3) Red light group: 670 nm (wavelength from 640 to 690 nm). During the first 18 days of the incubation period, continuous illumination of 0.1-0.2 lx intensity was provided with LEDs placed on both sides of the trays. The light transmission was prevented by blank trays coated with greenhouse covering material which has 75% shading feature placed among experiment groups. In this way, light transmission to other trays and any possible hitches of air circulation was prevented. There was no difference between examined egg weights of the treatment groups in the experiment, but it’s found that significant difference in egg weight loss for both colours of light. Red light and control groups (15.00% and 11.92%) show a similar embryonic mortality rate, while the green light group has a lower embryonic mortality rate (5.00%) than these groups. The effects of monochromatic lighting on the hatching time were significant (Chi-square<0.05). Although there was no significant difference between hatching performance parameters of the control and red light treatment groups in the experiment, the green light group had better hatching efficiency than the other groups. The findings of this research were carried out with two different light wavelengths are remarkable for showing that the significant effects of the monochromatic illumination on hatching results.

Application of red light therapy for moderate-to-severe acne vulgaris: A systematic review and meta-analysis.

Photodynamic therapy had made great progress in the treatment of acne vulgaris. However, there is no meta-analysis on the effectiveness and safety of red light therapy for acne vulgaris. To assess the efficiency and safety of red light therapy for acne vulgaris. PubMed, Cochrane Library, EMBASE, and Web of Science were retrieved to identify related studies. The outcomes were expressed as improvement in the average percentages of inflammatory acne lesions (MPRI) and non-inflammatory acne lesions (NMPRI), as well as the improvement of acne lesions respectively after treatment. 13 randomized controlled trials (RCTs) consisting of 422 participants were included. There was no significant difference in the average number of non-inflammatory lesions (weighted mean difference (WMD=-0.527; 95% CI,-3.055~2.001; p=0.683). Moreover, there was no statistically significant difference in the average number of inflammatory lesions (WMD =0.701; 95% CI, -0.809~2.212; p =0.363). In the subgroup analysis of the outcome changes in comedones, pustules, papules, and total lesions, it was found that red light therapy elicited no significant superiority compared with other conventional treatment methods (WMD=-1.125; 95% CI, -3.122~0.873; p=0.270). Adverse events of the red light group were generally mild or even completely non-existent. There was no statistically significant difference between red light therapy and traditional therapies in terms of efficacy. However, due to the heterogeneity of the researches and the lack of large sample size, the result of this study needs to be interpreted with caution.

Blue light regulates the expression of brain derived neurotrophic factor in the habenula nucleus of depression-like rats induced by light deprivation

Objective: To investigate the regulatory effect of blue light on the expression of brain derived neurotrophic factor (BDNF) in the habenula nucleus of depression-like rats induced by light deprivation. Methods: male SD rats were exposed to white light (white light control group, 20 rats) and constant darkness (depression model group, 60 rats), respectively. 18 days later rats in depression model group were randomly divided into three groups: depression model group (treated with constant darkness), blue light group (treated with blue light) and red light group (treated with red light). Rats in white light control group were kept in white light. All rats exposed to light were in a standard 12∶12 h Light/Dark condition at 20 lx for 36 days. Sucrose preference test was applied to evaluate depression-like symptoms of rats. The c-fos+cells in the habenula nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus were detected. The phosphoylation of cAMP-response element binding protein (CREB) and the relative BDNF protein level in the habenula nucleus were measured. Results: Sucrose intake per kg body weight increased in rats exposed to blue light and returned to the level of control group (P>0.05). Sucrose intake per kg body weight in red light group and depression model group were lower than control group (P<0.05). More c-fos+cells were detected in the habenula nucleus, intergeniculate leaflet and ventral lateral geniculate nucleus from blue light group than those from depression model group (P<0.05). The relative BDNF protein level and the phosphoylation of CREB in the habenula nucleus from blue light group were higher than those from depression model group (P<0.05). Conclusion: Blue light could relieve depression-like symptoms in light-deprived rats. Exposure to blue light could activate neurons in the habenula nucleus to which intrinsically photosensitive retinal ganglion cells projected. Blue-light-mediated antidepressant effect might involve in the activation of CREB/BDNF signal transduction pathways in the habenula nucleus.

Effects of LED Light Withering on the Quality of White Tea

Fresh leaves were used to evaluate the effects of LED light on the main contents of white tea during the withering process. According to the results, the content of tea water extract was increased by LED light withering; tea polyphenols in blue light group was the lowest compared to other treatments; amino acids in red-light group was the highest. LED light withering had obvious effect on the appearance, aroma and taste of white Tea. The tea in red and blue light treatments had natural shape, dark green color, fresh aroma, mellow taste, and in the red-light treatment had flower fragrance; however, the tea in the green light treatment had pure aroma and mellow taste; the sensory evaluation results showed that the quality of the light group was better than that of the control group, and the sensory quality of the comprehensive evaluation was the best.

The effect of LED photobiomodulation on the proliferation and osteoblastic differentiation of periodontal ligament stem cells: in vitro

The aim of this study was to investigate the influence of three different light-emitting diode (LED) wavelengths on the proliferation and osteoblastic differentiation of periodontal ligament stem cells (PDLSCs) in vitro. PDLSCs seeded on 96- and 24-well plates, for proliferation and osteoblastic differentiation, respectively, were irradiated daily by LED light with peak emission wavelengths of 630, 680, and 830 nm at constant energy densities of 3.5 J/cm2. Cultures were grown for 8 days for the proliferation assay, 10 days for the alkaline phosphatase (ALP) assay, and 28 days for Alizarin red staining. Mitochondrial activity, ALP enzyme level, and the ability to form calcium phosphate deposits were measured and compared across cultures. Results obtained from statistical analysis of the experimental data indicated that the rate of proliferation (P < 0.05) in 830-nm irradiated cultures were significantly higher than the control samples at day 6 and 8; whereas, for the 630- and 680-nm groups, test results showed lower proliferation rates at day 8. For osteoblastic differentiation, significantly greater mineralization than the control samples was detected in the red-light groups (630 and 680 nm) during the late differentiation period (P < 0.001), which was supported by a higher ALP activity of the 630- and 680-nm groups in the early stage (P < 0.01). The results of this study demonstrate that the PDLSCs responded differently to specific LED wavelengths. For enhancing cellular proliferation, 830-nm LED irradiation was more effective. On the other hand, the wavelengths of 630 and 680 nm were better for stimulating osteoblastic differentiation.