Ultraviolet radiations (UVR) produce harmful entities and reactive oxygen species (ROS) in skin cells, leading to skin photoaging. Caviar extract (CE) showed outstanding effects in delaying skin aging, but the underlying mechanism remains largely unknown. In this study, we prepared CE with acid protease and examined the anti-skin photoaging effects. The results showed that CE performed no cytotoxicity to HaCaT cells. For antioxidant properties, the EC50 values of DPPH and ABTS radical scavenging activity for CE were 1.27 and 5.20 mg/mL, respectively. It significantly reduced NF-κB, MMP-3 and MMP-9 protein expression levels, and increased IκB and TIMP-1 expression level in UVA-irradiated HaCaT cells. In the skin aging mice model, CE reduced the degree of UV-induced skin photoaging. Histological study confirmed that CE can ameliorate the adverse effects of UV exposure on the skin. Moreover, we found that CE could enhance the activities of Superoxide dismutase (SOD), and increased the contents of hydroxyproline (HYP) in photoaged mice skin. And CE elevated the protein expression level of COL17A1, KRT10, and KRT14 in mice skin. Taken together, our results bright systemic and new insights of CE into preventing UV-induced skin photoaging.

The advent of chatbots raises the possibility of a paradigm shift across society including the most technical of fields with regard to access to information, generation of knowledge, and dissemination of education and training. Photochemistry is a scientific endeavor with roots in chemistry and physics and branches that encompass diverse disciplines ranging from astronomy to zoology. Here, five chatbots have each been challenged with 13 photochemically relevant queries. The chatbots included ChatGPT 3.5, ChatGPT 4.0, Copilot, Gemini Advanced, and Meta AI. The queries encompassed fundamental concepts (e.g., "Why is the fluorescence spectrum typically the mirror image of the absorption spectrum?"), practical matters (e.g., "What is the inner filter effect and how to avoid it?"), philosophical matters ("Please create the most important photochemistry questions."), and specific molecular features (e.g., "Why are azo dyes non-fluorescent?"). The chatbots were moderately effective in answering queries concerning fundamental concepts in photochemistry but were glaringly deficient in specialized queries for dyes and fluorophores. In some instances, a correct response was embedded in verbose scientific nonsense whereas in others the entire response, while grammatically correct, was utterly meaningless. The unreliable accuracy makes present chatbots poorly suited for unaided educational purposes and highlights the importance of domain experts.

The Mimosa pudica leaf has motor organs allowing movements driven by cell osmotic changes in the parenchyma cells in response to various stimuli. Short white light pulses induce rapid and large seismonastic-like movements (denoted "photostimulation") of the primary pulvini in various leaves within 120 s after the onset of light. An early event recorded is a wavelength-related modification of the plasma membrane difference: potential depolarization under white, blue, green, and red wavelengths, and hyperpolarization under far red wavelengths (and also in darkness). The photoreactivity of the pulvini is controlled by a circadian rhythm and modulated by the applied diurnal photoperiod cycle (photophase ranging from 6 to 18 h). The reactivity varied among plants and even between leaves on the same plant. The level of reactivity is related to the photon fluence rate in the range from 10 to 140 μmol m s under white light and to the experimental temperature in the range 15°C-35°C. An "accommodation" to light supply is evidenced by a modulation of the reactivity in relation to the schedule of light application under low fluence rates and the introduction of short darkness intervals during the first 30-s light pulse. The blue light-induced photostimulation is under phytochrome control.

Photobiomodulation (PBM) shows beneficial effects on obesity-related alterations. It is not known if dual- is more beneficial than single-wavelength, nor the dose-response effect of such treatments. The effects of different doses of single- and dual-wavelength whole-body PBM on metabolic parameters in obese mice were evaluated. Male Swiss albino mice were fed with standard (Chow) or a cafeteria (CAF) diet and allocated into Sham (lights off), and PBM (whole-body blanket (140 cm) composed of 20 LED clusters, 2.14 mW/cm/cluster, for 67 or 133 s: 1 or 2 J per cluster; 20 and 40 J total energy; and 0.143 and 0.286 J/cm) with 660 nm (660), 850 (850) nm, or 660 nm + 850 nm (660/850). CAF induced insulin resistance that was inhibited in 660-1, 660-2, 850-1, and 660/850-2. CAF increased serum total cholesterol that was inhibited in 660-1, 660-2, 850-1, 660/850-1, and 660/850-2. There were no PBM-induced changes in other variables assessed. The effects of whole-body PBM in metabolic paraments in obese mice were wavelength and dose dependent: increasing the dose for 660 did not affect the outcomes; increasing the dose for 850 negatively affected the outcomes, and increasing the dose for 660/850 was mostly beneficial on the outcomes.

Water decreases the brightness of the peroxyoxalate chemiluminescence partially due to the hydrolysis of the oxalate reagent. Here, we show that encapsulation of an oxalate ester and the fluorescent activator in microspheres of cellulose esters increases the emission intensity 30 times compared to the same reaction in water without encapsulation, whereas the emission intensity decay rate constants are considerably lower. Emission intensities, rate constants and chemiluminescence quantum yields increase with increasing hydrogen peroxide concentrations. These results expand the potential of application of chemiluminescence, contributing for the development of ultrasensitive analytical methods.

The green-light driven photocatalytic N-deethylation reaction of Rhodamine B (RhB) on a TiO film was investigated by UV-vis absorption and fluorescence emission spectroscopies, in addition to HPLC and HR-MS, to ascertain the nature of the reaction products. The evolution of the photocatalytic reaction was chemometrically analyzed using Multivariate Curve Resolution-Alternating Least Squares (MCR-ALS) of the spectroscopic data to obtain the kinetic and spectral decomposition of the RhB derivatives involved in the reaction. This was then compared with the results obtained by standard HPLC analysis. The MCR-ALS analysis yielded satisfactory spectral and kinetic profiles for RhB and the fully deethylated product, Rhodamine 110. However, the spectral profiles for the N-triethyl (3EtRh) and the mixture of the two isomeric N-diethyl (2EtRh) derivatives exhibited some spectral distortions due to significant spectral overlap between these compounds. In contrast to the HPLC analysis, the MCR-ALS could not resolve the N-ethylrhodamine (EtRh) derivative. The deethylation reactions occurred via independent zero-order steps at the surface of TiO, indicating that the RhB degradation reaction is governed by the adsorption-desorption equilibrium of the dye and derivatives on the photocatalyst surface, thereby enhancing the diffusion of compounds on the surface.

Guidance on maximal limits for ultraviolet (UV) exposure has been developed by national and international organizations to protect against adverse effects on human skin and eyes. These guidelines consider the risk of both acute effects (i.e., erythema and photokeratitis) and delayed effects (e.g., skin and ocular cancers) when determining exposure limits, and specify the dose a person can safely receive during an 8-h period without harmful effects. The determination of these exposure limits relies on the action spectra of photobiological responses triggered by UV radiation that quantify the effectiveness of each wavelength at eliciting each of these effects. With growing interest in using far-UVC (200-235 nm) radiation to control the spread of airborne pathogens, recent arguments have emerged about revisiting exposure limits for UV wavelengths. However, the standard erythema action spectrum, which provides some of the quantitative basis for these limits, has not been extended below 240 nm. This study assists to expand the erythema action spectrum to far-UVC wavelengths using a hairless albino mice model. We estimate that inducing acute effects on mouse skin with 222 nm radiation requires a dose of 1162 mJ/cm, well above the current ACGIH skin exposure limit of 480 mJ/cm.

This study aims to evaluate and compare the effect of fibroblastic growth factor 2 (FGF-2) and photobiomodulation, solely or in combination, in angiogenic differentiation of human periodontal ligament stem cells (hPDLSCs). The study comprises the following groups: control group (hPDLSCs only), FGF-2 (50 ng/mL) group, two photobiomodulation groups with a 4 J/cm energy density of 808 nm diode laser (1-Session or 2-Session), and two groups with the combination of each 1-Session or 2-Session photobiomodulation with FGF-2 (50 ng/mL). The 4',6-diamidino-2-phenylindole (DAPI) staining, and Methyl Thiazolyl Tetrazolium (MTT) assay were undertaken on days 2, 4, and 6. Quantitative Real-time Polymerase Chain Reaction (RT-qPCR) analysis on days 2, 4, 6, 8, and 11 was conducted to investigate VEGF-A and ANG-I genes. Coherently, the results of the DAPI and MTT showed the Laser (2-Session) group had higher cell viability than others on day 6. All groups demonstrated a growth pattern in the expression of VEGF-A and ANG-I from day 2 to 8 and, afterward, a significant downgrowth to day 11 (p < 0.05). The most amounts of expression of VEGF-A and ANG-I on day 8 were seen in the Laser (2-Session) group. Two-time application of photobiomodulation using a diode laser with 808 nm wavelength after 2 and 4 days of cell seeding can be associated with higher cell viability and angiogenic differentiation of hPDLSCs compared to the one-time application of photobiomodulation and administration of FGF-2.

To elucidate the inhibition effects of Zn and Cd on the luciferin-luciferase reaction, we performed quantitative measurements of quantum yields and spectral shapes for in vitro firefly bioluminescence in aqueous solutions containing ZnSO, ZnCl, CdSO, and CdCl at different concentrations. Particular care was taken toward the equilibrium between metal ions and enzyme proteins, anion difference, solubility, and uncertainty evaluation. The bioluminescence quantum yields decreased almost linearly to the concentration of Zn and Cd below 0.25 mM. No obvious difference was found between the chloride and sulfate anion solutions. We defined inhibition sensitivity as the decrease in relative quantum yield versus the concentration of metal ions, and they were determined to be 1.48 ± 0.13 and 1.13 ± 0.16/mM for Zn and Cd, respectively. We estimated the detection limit of inhibition effects as the concentration of metal ions that decrease relative quantum yields by 10%, which were 0.07 mM (4 ppm) and 0.09 mM (10 ppm) for Zn and Cd, respectively. The shape of the bioluminescence spectra changed sensitively with the increase in Zn concentrations. The bioluminescence peak energy for 0.10-mM Zn was ~2.2 eV, while that for 0.25-mM Zn was ~2.0 eV. The shape of the spectra changed less sensitively with the increase in Cdconcentrations, and the peak energy was at ~2.2 eV for Cd concentrations of 0.10 and 0.25 mM.

Mitochondria play an important role in cellular function, not only as a major site of adenosine triphosphate (ATP) production but also by regulating energy expenditure, apoptosis signaling, control of the cell cycle, cellular growth, cell differentiation, transportation of metabolites, and production of reactive oxygen species. Interaction with electromagnetic waves can lead to dysregulation or alterations in the patterns of energy activities in the mitochondria. Ultraviolet light (UV) can be found in sunlight and artificial sources, such as lamps. UV radiation can cause damage to DNA, proteins, and lipids. Besides that, UV radiation is largely used in microorganism disinfection. To establish possible alterations in mitochondrial bioenergetics, this study proposes to investigate the UV (at two distinct intervals) effects on isolated mitochondria from mice liver to obtain direct responses and selective permeability of the internal membrane information. UVA-371 and UVC-255 nm lamps were used to irradiate, at different doses varying from 22.5 to 756 mJ/cm, isolated mitochondria samples. Mitochondrial respiration pathways were investigated by high-resolution respirometry, and possible mitochondrial membrane damages were evaluated by mitochondrial swelling by spectrophotometer analysis. UVC irradiation results (in the higher dose) indicate decrease in 75% of mitochondrial bioenergetics capacity, such as limitation of oxidative phosphorylation in 60% and increased energy dissipation in 30%. Mitochondrial swelling experiments (spectrophotometer) indicated inner membrane damage, and consequently a loss of selective permeability. Direct correlation between irradiation and effect responses was observed, mitochondrial bioenergetics is severely affected by UVC radiation, but (UVA) radiation did not present bioenergetic alterations. These alterations can contribute to improving the knowledge behind the cell death mechanism in disinfection UV light and UV therapy such as phototherapy.

Rose bengal (RB) is a widely used photosensitizer for determining quantum yields of singlet oxygen generation. While it is known to aggregate in polar environments at concentrations above 2 μM, the relationship between RB concentration and singlet oxygen photogeneration remains unclear. This study investigates the shift from monomeric to dimeric RB with increasing concentration and its impact on singlet oxygen generation in DO-based solutions and DMPC liposomes. Absorbance maxima for RB were observed at 514 nm (dimer) and 549 nm (monomer), with ionic environments influencing aggregation rates. Singlet oxygen phosphorescence showed non-linear dependency above 2 μM, indicating the effects of aggregation. Results suggest that RB concentrations should be kept at 1 μM or lower in photochemical studies to avoid aggregation-related discrepancies in singlet oxygen yield determination. These findings highlight the importance of considering RB aggregation in photochemical research and medical applications.

Spectroradiometry, radiometry, and dosimetry are employed for the measurement of ultraviolet radiation (UVR) irradiance and non-ionizing exposure. Different types of UVR dosimeter have been developed for measuring personal and environmental UVR exposures since film dosimetry was pioneered in the 1970s. An important type of dosimeter is the thin film variant, which contains materials that undergo changes in optical absorbance when exposed to UVR. These changes can be measured at a specific wavelength using a spectrophotometer. Thin film dosimeters allow UVR exposure measurements on humans at various body sites during daily activities, as well as on plants, animals, and any sites of interest when utilized in a field environment. This review examines the properties and applications of five types of thin film UVR dosimeter that have different dynamic exposure limits and spectral responses. Polysulphone, with a spectral response approximating the human erythema action spectrum, was one of the first materials employed in thin film form for the measurement of UVR exposures up to 1 day, and up to 6 days with an extended dynamic range filter. Polyphenylene oxide has been characterized and employed for personal UVR exposure measurements up to approximately four summer days and has also been used for long-term underwater UVR exposures. Phenothiazine and 8-methoxypsoralen have been reported as suitable for the measurement of longer wavelength UVA exposures. Finally, polyvinyl chloride with an extended dynamic exposure range of over 3 weeks has been shown to have predominantly a spectral response in the UVB and extending up to 340 nm.

Superhydrophobic antimicrobial photodynamic therapy (SH-aPDT) is advantageous wherein airborne singlet oxygen (O) is delivered from a device tip to kill a biofilm with no photosensitizer exposure and no bacterial selectivity (Gram + or Gram -). For effective treatment of periodontitis, the frequency of treatment as well as the optical light fluence required is not known. Thus, we sought to determine whether single or repeated SH-aPDT treatments would work best in vivo using two fluence values: 60 and 125 J/cm. We assessed the efficacy of three protocols: single treatment; interval treatments (days 0, 2, and 7); and consecutive treatments (days 0, 1, and 2). After 30 days of evaluation, we found that, SH-aPDT in 3 consecutive treatments significantly decreased Porphyromonas gingivalis levels compared to single and interval SH-aPDT treatments, as well as SRP-chlorhexidine (CHX) controls (p < 0.05). Notably, clinical parameters also improved (p < 0.05), and histological and stereometric analyses revealed that consecutive SH-aPDT treatments were the most effective for promoting healing and reducing inflammation. Our study shows what works best for SH-aPDT, while also demonstrating SH-aPDT advantages to treatment of periodontitis including no bacterial selectivity (Gram + or Gram -) and preventing the development of bacterial resistance.

Photodynamic therapy (PDT) effectively kills cancer cells and initiates immune responses that promote anticancer effects locally and systemically. Primarily developed for local and regional cancers, the potential of PDT for systemic antitumor effects [in situ photo-vaccination (ISPV)] remains underexplored. This study investigates: (1) the comparative effectiveness of paclitaxel (PTX) prodrug [Pc-(L-PTX)] for PDT and site-specific PTX effects versus its pseudo-prodrug [Pc-(NCL-PTX)] for PDT combined with checkpoint inhibitors; (2) mechanisms driving systemic antitumor effects; and (3) the prophylactic impact on preventing cancer recurrence. A bilateral tumor model was established in BALB/c mice through subcutaneous injection of CT26 cells. Mice received the PTX prodrug (0.5 μmole kg, i.v.), and tumors were treated with a 690-nm laser (75 mW cm for 30 min, drug-light interval 0.5 h, light does 135 J cm), followed by anti-CTLA-4 (100 μg dose, i.p.) on days 1, 4, and 7. Notable enhancement in both local and systemic antitumor effectiveness was observed with [Pc-(L-PTX)] compared to [Pc-(NCL-PTX)] with checkpoint inhibitor. Immune cell depletion and immunohistochemistry confirmed neutrophils and CD8+ T cells are effectors for systemic antitumor effects. Treatment-induced immune memory resisted newly rechallenged CT26, showcasing prophylactic benefits. ISPV with a PTX prodrug and anti-CTLA-4 is a promising approach for treating metastatic cancers and preventing recurrence.

This study was designed to determine the effect of photobiomodulation therapy on dental implant stability. A complete systematic search was performed in PUBMED/MEDLINE, COCHRANE library databases, EMBASE, SCOPUS, and Google Scholar databases on articles published until June 2024. All the RCTs and CCTs reported the solo impact of photobiomodulation on dental implant stability in humans were included. The means and standard deviation for implant stability and sample size were extracted for the meta-analysis. The statistical analysis was conducted using Stata 17 software, and random effect models were applied to assess the source of heterogeneity. The I2 statistic was used to estimate the significance of any discrepancies in the therapy result. After a full-text inspection, 17 articles were qualified for systematic review, and 14 were included in the meta-analysis. Statically significant differences in implant stability were observed between the laser and the control groups on weeks 2 in ISQ reporting groups (p = 0.01, CI 95%) and weeks 4 and 8 in PTV reporting groups (p < 0.001, CI 95%). Despite limitations, the study suggests that PBM therapy benefits patients with dental implants at different periods, particularly during the early phases of healing.

Dental fear and phobia are prevalent worldwide, with local anesthesia being the most feared procedure. This study aimed to determine whether photobiomodulation therapy (PBMT), used as a pre-anesthetic, could modulate puncture pain and enhance the effectiveness of local anesthesia. In this controlled, randomized, double-blind study, 49 participants were divided into an experimental group (n = 24), which received infrared laser therapy (100 mW, at 808 nm, 8 J, 80 s at a single point) immediately before standard anesthesia; and control group (n = 25), which received the standard anesthetic technique and sham laser. Pain levels were measured using the visual analog scale, and anesthetic efficacy was assessed through electrical tests (latency), percentage of failures, and cartridge usage. Anxiety levels were evaluated using the Beck Anxiety Inventory. Cardiovascular parameters were evaluated through blood pressure, oxygen levels, and heart rate. This randomized, double-blind study found no difference between groups in these experimental conditions. The bias toward a positive PBMT result was sufficiently removed. Autonomic responses of the PBMT group were maintained stable during the procedure.

Thirty years ago, the Global Solar UV Index (UVI) has been introduced as a health promotion instrument to improve sun protection. We assessed systematically global levels of awareness and use of the UVI as a prerequisite for the preventive effectiveness of this public health tool. We conducted a comprehensive literature search across 10 databases, including PubMed, Scopus and Web of Science Core Collection, as well as clinical trial registries and gray literature databases. The risk of bias of studies was evaluated using the Joanna Briggs Institute checklist for prevalence studies. In addition to narrative and descriptive analysis, we performed meta-analyses with geographical subgroup analyses to statistically summarize the results. In total, we identified 40 publications from 39 different studies across multiple global regions. However, the number of studies in the analyses varies depending on the outcome. The results, especially the awareness of the UVI, were largely dependent on the specific geographical location of the studies. While the prevalence of awareness of the UVI is high among Australian populations, there is considerable variability in levels of awareness across other global regions. At the same time, the use of the UVI is at a low level across all regions, demonstrating the need for enhanced dissemination of knowledge about the perils associated with ultraviolet radiation and the advantages of using the UVI.

Consuming microbiologically-contaminated water is the primary cause of many water-borne diseases and deaths worldwide. Governments aim at providing drinking water for vulnerable populations, especially through low-cost interventions. Therefore, the solar disinfection (SODIS) of such pathogens provides a simple and cost-effective way to obtain good quality water. In this procedure, PET bottles are filled with contaminated water and exposed to sunlight for 1-2 days. To accelerate decontamination, methylene blue (MB) dye added as a photocatalyst, boosts singlet oxygen generation upon absorbing red-band sunlight. This study explores the use of a Sunlight Simulator (SSL) device to research and standardize the SODIS method with a vital dye as MB. PET bottles were filled with artificially-contaminated water with Streptococcus epidermidis and Deinococcus radiodurans Gram-positive bacteria, Escherichia coli and Salmonella typhimurium Gram-negative bacteria, or bacteriophage λ as well. In all experiments, 50 ng/mL MB ensued a synergistic lethal effect after SSL exposure. The results indicate that bacterial and bacteriophage inactivation can be achieved in shorter times with MB-SSL treatment compared to SSL without MB. In this sense, when compared to previous sunlight-SODIS results, the SSL source is a reliable tool to study the parameters of both SODIS and MB-SODIS protocols, and also a feasible tool to afford assays whenever there are unfavorable climate conditions.

This study assessed the effects of red and green LEDs on mast cells (MCs) in third-degree burns in 75 Wistar rats, divided into control, red LED (RED), and green LED (GREEN) groups. Animals were irradiated daily with RED (630 nm, 300 mW, 0.779 W/cm, 9 J/cm, 30 s) and GREEN (520 nm, 180 mW, 0.467 W/cm, 60 J/cm, 30 s). Histological sections stained with toluidine blue were analyzed for total and subtype MCs. Standardized MC counting was performed across the viable lesion area, considering lesion margins, through intact connective tissue and the integrity of skin appendages. No statistically significant differences in MCs 2 (with released granules and intact cell border) were found between groups. Irradiated groups showed increased total MCs at 7, 14, and 21 days (p < 0.05), with a decrease in MCs 1 (intact MCs) at all time points compared to control (p < 0.05). Significant changes in MCs 3 (with massive degranulation and partial or complete disintegration of the cell border) degranulation were noted in RED at 7, 14, and 21 days (p < 0.009) and in GREEN at 14 (p < 0.009) and 32 days (p < 0.028). Results suggest red and green LEDs modulate MC recruitment and degranulation in third-degree burns.

Photoexcitation of cellular as well as isolated DNAs upon exposure to the UV portion of sunlight or other UV sources can lead to the covalent dimerization of adjacent intra-strand stacked pyrimidine nucleobase rings (i.e., at 5'-Py-p-Py-3' sites). These modifications generate, in mammalian DNA as well as the DNA of all other forms of life, lesions such as cyclobutane pyrimidine dimers (CPDs) and pyrimidine (6-4) pyrimidone photoproducts (6-4PPs); and, in bacterial endospores, spore photoproducts (SPs). Importantly, the lesions formed in higher organisms can lead to disease states including cancer. While the formation, structure, and biological outcomes of pyrimidine dimer lesions have been the focus of much research, less has been known about their fundamental chemical properties until recently. Such an understanding of these lesions may lead to novel means to chemically identify and quantitate their presence in the genome. This review is intended to provide an overview of intra-strand pyrimidine dimer lesions derived from 5'-T-p-T sites with a focus on presenting what is currently known about their individual in vitro alkaline chemical reactivities. Included here are descriptions of investigations of the DNA lesions CPD, 6-4PP, and SP, and, for comparison, the monomeric pyrimidine lesion 5,6-dihydo-2'-deoxyuridine (dHdU). Of interest, the alkaline hydrolyses of these various lesions are all found to be centered on the loss of aromaticity of a lesion Py ring (T) leading to a carbonyl "hot spot," the focal point of initial hydrolytic attack.