Effects Of Different Lights Research Articles

The Effect of Different Light Curing Modes on the Microhardness Value of Different Composite Resins

The Effect of Different Light Curing Modes on the Microhardness Value of Different Composite Resins

New Perspectives in Overcoming Bulk-Fill Composite Polymerization Shrinkage: The Impact of Curing Mode and Layering.

The purpose of this study was to investigate the effect of different light curing modes on the polymerization shrinkage of a bulk-fill composite and to evaluate the impact of two layering techniques on the cuspal deflection. Nine different light curing modes were tested on bulk-fill composite samples in aluminum MOD cavities. Intensity, duration, and illumination distance were the factors that changed during the different curing modes. The digital image correlation method was used to visually represent the displacement of carbon particles on the materials' surface caused by shrinkage along both the horizontal and vertical axes. For simulating cuspal deflection, a separate protocol was used, with a bulk and horizontal layering technique. The results showed that the largest horizontal displacements were present in the soft start group (6.00 ± 0.82 µm) and in the X-tra power group (5.67 ± 1.21 µm). The smallest horizontal displacements were detected in normal curing modes (4.00 ± 1.58 µm; 4.00 ± 2.68 µm). The largest vertical displacements, at the bottom layer, were present in the normal curing mode group with a 20 s curing time (5.22 ± 1.56 µm), while the smallest vertical displacements were shown in the X-tra power group (2.89 ± 0.60 µm). The observed particle displacements showing the shrinkage of the composite were correlated with the curing mode. The bulk-fill group showed less cuspal deflection than the horizontal layering group did, but the difference was not statistically significant (p = 0.575). Within the limitations of this in vitro study, it can be concluded that lower intensities of curing lights (1200 mW/cm2) may perform better from the point of view of material shrinkage than high and extreme light intensities do. The pulse delay mode might be recommended in the case of bulk-fill materials. The number of layers did not significantly affect the cuspal deflection in the case of the studied composite.

Effects of different light and heavy rare-earth compositions on structure and magnetic properties of high-entropy garnet ceramics

Effects of different light and heavy rare-earth compositions on structure and magnetic properties of high-entropy garnet ceramics

A modeling approach shows the effects of different light–dark schemes on the entrainment ability of the suprachiasmatic nucleus

A modeling approach shows the effects of different light–dark schemes on the entrainment ability of the suprachiasmatic nucleus

Farklı LED ışıklar altında yetiştirilen köksüz su mercimeğinin (Wolffia arrhiza) Dumas yöntemi kullanılarak ham protein içeriğinin belirlenmesi

Rootless duckweed (Wolffia spp.) has the potential high-protein food source for humans. Wolffia is a member of the Lemnaceae family and is the world's smallest spermatophyte, with reduced roots, stems, and leaves. Scientific research on Wolffia species is relatively new, and this species is believed to be rare in Turkey. The phytochemicals and nutritional composition of plants are significantly affected by environmental factors in the natural or cultivated medium. In this study, Wolffia arrhiza was collected and cultured from a local area in Yeşilırmak Delta (Samsun) grown under controlled conditions using different LED lights. The Dumas method was used to determine the amount of crude protein. The protein content, calculated by multiplying the nitrogen (%) content by the standard conversion factor 6.25, was also evaluated by using different conversion factors in the literature. The results showed that rootless duckweed can be successfully grown under artificial lighting conditions with different light spectrums. The protein content of rootless duckweed, which was around 10% in the natural environment, increased considerably under red LED light (41.6% protein). The effect of different lights on protein content of W. arrhiza was observed as red LED > blue LED > purple LED > fluorescent. With its high protein content, environmentally friendly and sustainable production, Wolffia has the potential to quickly take place in the plant-based protein and functional food market as an alternative to traditional crops in the near future.

Effect of different light on microalgae growth and its integration with carbon dioxide sequestration technologies with emphasis on biofixation by microalgae

The increase in concentration of carbon dioxide in the atmosphere over several years has led to surge in global catastrophe. The average carbon dioxide concentration reported in 2021 was 416.45 parts per million (ppm) with decadal average growth rate of 2.43 ppm per year. To mitigate global climate change, increase in carbon dioxide and other greenhouse gases have become a matter of concern. Thus, carbon capture and storage (CCS) is a promising method for reducing carbon dioxide from the atmosphere. Various CCS technologies have been discussed with emphasis on biofixation of CO2. Microalgae have been studied and tested for several years due to many of its advantages. One of its benefits is consuming CO2 for its growth and converting them into biomass leading to reduction of CO2 in a sustainable manner and thereby producing several value-added products. The vision of this paper is to study the potentials of various microalgae for fixing CO2. By a combination of various research studies this article aims for a more sustainable approach by using microalgae and its mechanism that can naturally utilize CO2.

The Effect of Different Light Curing Units and Tip Distances on Translucency Parameters of Bulk fill Materials

ObjectivesTo evaluate the effect of light curing unit (LCU) types and distance from light curing unit tip on the translucency parameters (TP) of bulk fill composite materials. Materials and MethodsTwo bulk-fill resin composites and one nanohybrid composite were used in this study. The specimens were divided into groups based on the type of curing unit used, and further subdivided based on the distance of the curing source to the surface of the resin composite. Translucency was evaluated at 4 mm thickness (for the bulk-fill) and 2 mm thickness (for nanohybrid) after curing using two different light curing units at zero, 2 mm, and 4 mm distance. The results were analyzed using two-way ANOVA at the significance level of a p-value of < 0.05. ResultsAmong all the tested materials, Filtek Bulk Fill Posterior RBC showed the highest TP at 0 mm distance when cured with Blue phase G2 LED LCU and it was the least affected by the differences in distances. However, Filtek Z350 nanohybrid composite had no significant differences between the three distances when cured with Blue phase G2 LCU. ConclusionTranslucency values among the studied bulk-fill materials are affected by material composition, curing units and the distance of the tip of the light source to the restoration surface.

Effect of Different Light Curing Distances on Surface Hardness of Two Different Bulk-Fill Flowable Resin-Based Composite Materials

Effect of Different Light Curing Distances on Surface Hardness of Two Different Bulk-Fill Flowable Resin-Based Composite Materials

Effects of Different Light and Temperature Treatments on Seed Germination and Seedling Growth of Vegetables

Vegetable refers to a kind of plant or fungus that can be used for cooking and becoming food. It provides a variety of vitamins, minerals and other nutrients necessary for human body. It is an important cash crop for people. Plant growth and development is greatly affected by light and temperature conditions, especially vegetables will directly affect the economic benefits. To explore light temperature conditions on the vegetable seed crop growth and development, the influence of this experiment will by creating the light of the different temperature conditions on the Thai water convolvulus, Tianjin 60 Chinese cabbage, Celandine wheat and precocious 8, four kinds of vegetable seeds processing, temperature different light on the conditions of the four kinds of vegetable seeds and seedling bud rate, root weight. Two experiments, respectively, set up four controls, the results showed that different vegetable seeds need appropriate illumination and temperature conditions vary, but most of the germination rate and grew well in about 25 °C, 18 hours of light and dark 6 hours under the condition of the most suitable for their growth.

Effect of Different Light on Wheat (Triticum aestivum L) Growth and Role of Phytochrome

Among the various naturally occurring abiotic factors regulating plant development, different types of light play an important role in them. Photosynthesis, photoperiodism, and photo morphogenesis. In this trial the effects of different colors of light on (seed) germination, phytochrome conversion, length of seedling, biomass production in wheat varieties Shalkot and Tandojam. The rate of germination data indicates white 96%, Red 100%, far-red 95%, Blue 95%, and dark 64%, in Shalkot. In Tandojam rate of germination 94% White, 93% red, 82% far red, 92% blue, and 50% dark, were observed. Root and shoot length were higher in Shalkot under white light. Difference between dry and fresh weight in Shalkot under white, red, far-red, blue, dark, 1.66g, 0.94g, 0.98g, 0.97g, 0.6g, respectively. In Tandojam difference between dry and fresh weight observed under white, red, far-red, blue, dark, 1.48g, 0.92g, 0.70g, 0.97g, 0.4g respectively. By using bioinformatics tools identified some light-harvesting genes in wheat (Triticum aestivum) by using model plant Arabidopsis thaliana. The identified light-harvesting genes include cl02879, cl25816, cl33336, cl31857, cl28913.

Transcriptome analysis of flowering regulated by red and blue light in Jasminum sambac

Jasminum sambac is a perennial evergreen shrub plant. With fragrant and aroma, and often used as a raw material for natural spices. In this study, we used white light as the control group, red-light and blue-light as the treatment to study effects of different light on jasmine flowering. Red- light promoted jasmine flowering in advance and increased the number of flower buds, whereas blue-light delayed jasmine flowering and decreased the number of flower buds. There was significant difference on the number of flower buds among the three groups. The top buds' transcriptomes of different light were sequenced by the Illumina Hiseq/Miseq 2000 high-throughput sequencing technology. In total 2 452 457 Unigenes were generated by transcriptome sequencing, of which 1 760 723 Unigenes were annotated into GO, COG, KEGG, KOG, NR, Pfam, Swiss-Prot, NOG databases. There were 894 DEGs in the control group vs red-light group, 2 690 DEGs in the control group vs blue-light group, and 3 828 DEGs in the red-light group vs blue-light group. KEGG Enrichment analysis reveals that the significant enrichment pathways had 6 pathways, including secondary metabolite biosynthesis, phenylpropanoid biosynthesis, indole alkaloid biosynthesis, photosynthesis, plant hormone signaling, and plants-pathogen interactions, and 24 related DEGs were detected by RT-qPCR, the result of which was significantly correlated with the transcriptome data. Through further analysis of transcriptome data, a large number of flowering-related hormones (IAA, ETH, GA, CTK, ABA, SA, JA) signal transduction genes and flowering pathway-related regulatory genes (PHY, CRY1, FPA, AGL and SOC1) and transcription factor (bHLH, MYB, WKRY) family genes were found. The study will help elucidate the differential expression mechanism of different light regulation of jasmine flowering.

Light and irrigation effects on chlorophyll fluorescence depend on seedling provenance in Magnolia pugana endemic of Mexico

In riparian forests, light and water are two important factors for plant acclimation to different environments. We evaluated the effect of different light and irrigation regimes on the effective quantum yield of photosystem II (фPSII), the maximum quantum efficiency of photosystem II (Fv/Fm), and the electron transfer rate (ETR) of Magnolia pugana seedlings that come from wild and cultivated plants, under greenhouse conditions. Rapid light curves (RLCs) were performed to obtain the maximum apparent electron transport rate and the saturating photosynthetic photon flux density for PSII. Effective quantum yield of PSII was higher at afternoon for cultivated and wild provenances, but in the latter decreased in longest water deficit treatment at noon. The combined water deficit and high light stress in the morning decreased фPSII; however, фPSII recovered in the afternoon, suggesting dynamic photoinhibition. Furthermore, фPSII of wild and cultivated seedlings in all irrigation levels showed dynamic photoinhibition as well. The electron transfer rate was higher for seedlings grown under high light than in shade. ETR results suggest that wild seedlings showed greater tolerance to water deficit conditions than cultivated ones. Rapid light curves indicate that photosystem II of M. pugana seedlings grown in high light conditions requires higher light intensities to reach saturation. In conclusion, wild and cultivated populations of Magnolia pugana seedlings showed photochemical adjustments to tolerate water deficit and light stress. This study offers new insights into the physiology of endangered plants and valuable guidance for conservation efforts designed at protecting in situ and ex situ wild Magnolia species.

High Melatonin Conditions by Constant Darkness and High Temperature Differently Affect Melatonin Receptor mt1 and TREK Channel trek2a in the Brain of Zebrafish.

Ambient light and temperature affect reproductive function by regulating kisspeptin and gonadotrophin-releasing hormone (GnRH) in vertebrates. Melatonin and melatonin receptors, as well as the two-pore domain K+ channel-related K+ (TREK) channels, are affected by light and/or temperature; therefore, these molecules could modulate kisspeptin and GnRH against ambient light and temperature. In this study, we investigated the effect of light and temperature, which affect melatonin levels in gene expression levels of TREK channels, kisspeptin, and GnRH. We first investigated the effects of different light and temperature conditions on brain melatonin concentrations by ELISA. Fish were exposed to either constant darkness, constant light, high temperature (35°C), or low temperature (20°C) for 72 h. Brain melatonin levels were significantly high under constant darkness and high temperature. We further investigated the effects of high brain melatonin levels by constant darkness and high temperature on gene expression levels of melatonin receptors (mt1, mt2, and mel1c), TREK channels (trek1b, trek2a, and trek2b), gnrh3, and kiss2 in the adult zebrafish brain by real-time polymerase chain reaction. Fish were exposed to constant darkness or elevated temperatures (35°C) for 72 h. trek2a, kiss2, and gnrh3 levels were increased under constant darkness. High temperature decreased gene expression levels of mt1, mt2, mel1c, and gnrh3 in the preoptic area, whereas other genes remained unchanged. Melatonin receptors, TREK channels, gnrh3, and kiss2 responded differently under high melatonin conditions. The melatonin receptors and the TREK channels could play roles in the regulation of reproduction by environmental cues, especially ambient light and temperature.

Effect of Different light Curing Techniques on Color Stability of Two Resin Composites (An in vitro study)

Effect of Different light Curing Techniques on Color Stability of Two Resin Composites (An in vitro study)

Effect of different light-dark schedules on estrous cycle in mice, and implications for mitigating the adverse impact of night work.

Approximately 20% of workers in developed countries are involved in night work. Nevertheless, many studies have strongly suggested that night-work-induced chronic circadian misalignment increases the risk of a diverse range of health problems. Although a relation between night work and irregular menstrual cycles has been indicated epidemiologically, a direct causal link remains elusive. Here, we report that repetitive reversal of light-dark (LD) cycles triggers irregular estrous cycles in mice. The findings showed that the estrous cycle remained irregular for more than four weeks after the mice were returned to regular LD cycles. Importantly, the magnitude of the negative impact of reversed LD cycles on the estrous cycle, or more specifically the decreased number of normal estrous cycles during the observation period, was dependent on the difference in the frequency of LD reversal. Presently, no clear solution to prevent night-work-mediated menstrual abnormalities is available, and reducing night work in modern society is difficult. Our findings indicate that optimizing work schedules could significantly prevent menstrual problems without reducing total night-work time.

Differential impact in young and older individuals of blue-enriched white light on circadian physiology and alertness during sustained wakefulness

We tested the effect of different lights as a countermeasure against sleep-loss decrements in alertness, melatonin and cortisol profile, skin temperature and wrist motor activity in healthy young and older volunteers under extendend wakefulness. 26 young [mean (SE): 25.0 (0.6) y)] and 12 older participants [(mean (SE): 63.6 (1.3) y)] underwent 40-h of sustained wakefulness during 3 balanced crossover segments, once under dim light (DL: 8 lx), and once under either white light (WL: 250 lx, 2,800 K) or blue-enriched white light (BL: 250 lx, 9,000 K) exposure. Subjective sleepiness, melatonin and cortisol were assessed hourly. Skin temperature and wrist motor activity were continuously recorded. WL and BL induced an alerting response in both the older (p = 0.005) and the young participants (p = 0.021). The evening rise in melatonin was attentuated under both WL and BL only in the young. Cortisol levels were increased and activity levels decreased in the older compared to the young only under BL (p = 0.0003). Compared to the young, both proximal and distal skin temperatures were lower in older participants under all lighting conditions. Thus the color temperature of normal intensity lighting may have differential effects on circadian physiology in young and older individuals.

Effects of light curing modes and ethanol-wet bonding on dentin bonding properties

This study explored the effects of different light curing modes and ethanol-wet bonding on dentin bonding strength and durability. A total of 54 molars were randomly divided into three groups: Single Bond 2, Gluma Comfort Bond, and N-Bond. Based on the three light-curing modes and presence or absence of ethanol pretreatment, the samples were assigned to six subgroups: high-light mode, ethanol pretreatment+high-light mode, soft-start mode, ethanol pretreatment+soft-start mode, standard mode, and ethanol pretreatment+standard mode. All samples were bonded with resin based on the experimental groups. After 24 h and 6 months of water storage, a universal testing machine was used to measure microtensile bond strength. Scanning electron microscopy (SEM) was applied to observe mixed layer morphology. The 24-h and 6-month microtensile bond strengths of the ethanol pretreatment groups were significantly higher than those of the non-ethanol pretreatment groups at the same light modes (P<0.05). With or without ethanol pretreatment, the microtensile bond strengths of the high-light modes were significantly lower than those of the soft-start modes and standard modes (P<0.05). The microtensile bond strengths of samples from the 6-month water storage group significantly decreased compared with those of samples from the 24-h water storage group (P<0.05). The soft-start groups and standard groups formed better mixed layers than the high-light mode groups, whereas the ethanol pretreatment groups formed more uniform mixed layers than those without ethanol pretreatment. Ethanol-wet bonding technique, soft-start, and standard modes could improve dentin bonding properties.

IMPACT OF LIGHT AND SUGAR-FREE BEVERAGES ON DENTIN EROSION - AN IN VITRO STUDY

AIM: To compare the erosive effect of different light and sugar free beverages in relation to their regular version, on dentin. MATERIALS AND METHODS: Bovine root dentin samples were randomized into 9 different types of drinks (each n=12): Coca-cola®, Light Coca-cola®, Coca-cola® Zero, Guaraná Antartica®, Guaraná Antartica® Zero, Sprite®, Sprite® Zero, Del Valle® Passion fruit juice and Del Valle® Light Passion fruit juice. During each one of the 10 experimental days, the samples were subjected to 3 erosive demineralization (by immersion of the sample in the studied drink) and remineralization (by immersion of the sample in artificial saliva) cycles. Profilometry was evaluated at the end of the 1st, 5th and 10th days. For each type of drink, the data were tested using 2 way ANOVA and Bonferroni test (p&lt;0.05). RESULTS: Erosive cycling with regular cola resulted in a higher wear on the first day, on the 5th day the regular drink was similar to zero and greater than light version, on the 10th day there was no difference between the versions of cola drink. For the Sprite drink there was difference between the versions just in the 10th day, in which the higher wear was promoted by the zero version. For guaraná and juice beverages there was no differences between versions in relation to the resulted erosive wear. CONCLUSION: Erosive tooth wear promoted by light and sugar-free or regular versions of soft drinks and juices showed distinct behaviours over the cycling time.

Learning and Working Memory In Mice Under Different Lighting Conditions

Objective. This study aimed to investigate the effect of different light/ dark cycles and light intensity during behavioral tests of learning and working memory in Swiss mice. Method. Fifty-seven Swiss mice were kept in a housing room in either a 12:12h light/dark cycle (LD), constant light (LL), or constant darkness (DD). The animals were then tested in Lashley maze and Object recognition task under either 500 or 0 lux illumination, resulting in six treatments (LD-500, LD-0, LL500, LL-0, DD-500, and DD-0). Results. There were no significant differences between the conditions of light/dark, or between tests at 500 and 0 lux. Animals kept in constant darkness and tested at 0 lux (DD-0) had learning and working memory impaired, as demonstrated by slower learning in Lashley III maze, and no object recognition in Object recognition task. Conclusion. Continuous darkness throughout the experiment affected the learning and working memory of Swiss mice.

Learning and Working Memory In Mice Under Different Lighting Conditions

Objective. This study aimed to investigate the effect of different light/ dark cycles and light intensity during behavioral tests of learning and working memory in Swiss mice. Method. Fifty-seven Swiss mice were kept in a housing room in either a 12:12h light/dark cycle (LD), con­stant light (LL), or constant darkness (DD). The animals were then tested in Lashley maze and Object recognition task under either 500 or 0 lux illumination, resulting in six treatments (LD-500, LD-0, LL- 500, LL-0, DD-500, and DD-0). Results. There were no significant differences between the conditions of light/dark, or between tests at 500 and 0 lux. Animals kept in constant darkness and tested at 0 lux (DD-0) had learning and working memory impaired, as demon­strated by slower learning in Lashley III maze, and no object recogni­tion in Object recognition task. Conclusion. Continuous darkness throughout the experiment affected the learning and working mem­ory of Swiss mice.