Photochemical & Photobiological Sciences最新文献

The effects on the growth of basil (Ocimum basilicum L.) due to the presence of arsenic and vanadium, recently incorporated on the soil, were studied. Besides biomass and morphology, particular emphasis was placed in studying the effect on photosynthetic systems by spectroscopical methods, including reflectance and fluorescence (both stationary and variable) measurements. Assays were conducted in quadruplicate in the presence of arsenic, vanadium and both together, as well as control assays. Arsenic showed stronger effect on growth compared with vanadium, whereas both combined almost stopped growth. The presence of arsenic disrupted the photosynthetic machinery in basil, significantly impairing electron transfer processes within the chloroplasts. Notably, the negative effects on plants were most severe under both contaminants jointly, followed by arsenic alone, whereas vanadium alone showed the lesser effect.

Exposure to solar ultraviolet radiation (UVR) during childhood increases the risk of skin cancer later in life. Little is known regarding the extent of UVR exposure in children, particularly those aged 3-6 years. In this exploratory study, we investigated individual UVR exposure among Danish kindergarten children during the summer, by including children from two distinct types of kindergarten: a traditional Danish kindergarten with a playground (n = 17) and a forest kindergarten where children spend the entire day in a forest setting (n = 20). Children wore personal electronic wrist borne dosimeters, and their clothing coverage was recorded from 9:00 to 11:00 h, 11:00-13:00 h, and 13:00-15:00 h. The study included a sunny day and a cloudy day, and a ground station near both kindergartens measured ambient UVR on the same days. On the sunny day, children from the forest kindergarten received 2.4 standard erythema doses (SEDs; range 0.8-3.6; 7.6% of ambient UVR). This was significantly higher than the 1.0 SED (range 0.4-1.8; 3.4% of ambient UVR) received by children from the traditional kindergarten (p = 0.0000073). On the cloudy day, the forest kindergarten children also received significantly more UVR (1.3 SED; range 0.6-2.1; 5.3% of ambient UVR) than the traditional kindergarten children (1.0 SED; range 0.2-1.6; 4.3% of ambient UVR), but it was not significant (p = 0.056). Notably, the forest kindergarten children wore significantly more clothing. Children in both types of kindergarten received relatively high UVR doses. This highlights the importance of implementing sun protection strategies during kindergarten hours.

Posterior capsular opacification (PCO) causes the vision that has been restored after cataract surgery to become blurred again. YAG laser treatment for PCO not only incurs additional costs but also poses risks of complications, including glaucoma and retinal disorders. Effective prevention and management of PCO remain an area requiring active research. Photodynamic therapy (PDT) utilizes a photosensitizer (PS) to transform oxygen into reactive oxygen species (ROS) under specific wavelengths of light, thereby inducing apoptosis. Given its minimal invasiveness and high specificity, PDT has been extensively applied in the treatment of conditions characterized by abnormal cell proliferation, such as tumors. Considering the pathogenesis of PCO, PDT has demonstrated promising clinical application potential in ophthalmic disease treatment. This review examines the impact of photodynamic therapy on the biological behavior of lens epithelial cells (LECs) and its efficacy in treating PCO. It also discusses the advantages and disadvantages of different photosensitizers and their clinical application potential.

In recent years, mycosporine-like amino acids (MAAs) have gained attention in skincare products due to their natural photoprotective and antioxidant properties. These water-soluble compounds effectively absorb ultraviolet A and ultraviolet B radiation, with molecular absorptivity ranging from 12,400 to 58,800 M⁻¹·cm⁻¹. This review analyzes patents filed between January 2014 and December 2024 related to the use of MAAs in skincare, identifying key trends and innovations. A comprehensive search of the European Patent Office yielded 14 relevant patents. These patents showcase the increasing use of MAAs in sunscreens, anti-aging creams, and antioxidant formulations, with features such as enhanced water resistance, increased sun protection factor (SPF), and defense against electromagnetic radiation. China and Denmark led patent filings, reflecting their focus on technological advancements. Additionally, MAA-based products showed improved stability and efficacy, offering natural alternatives to synthetic UV filters. MAA concentrations in products ranged from 0.001 to 15%, and their use in nanoemulsions and self-preserving formulations marked progress in cosmetic applications. This review highlights the potential of MAAs as multifunctional skincare agents and emphasizes the global trend towards incorporating these bioactive compounds into cosmetic products.

Optical trapping at interfaces has emerged as a valuable research topic in the study of colloidal particles and soft matter. Objects are drawn from the irradiated cone-like region toward the laser focus, generating flow patterns beyond the focal area. Localized heating at the focus induces coupled effects on surface tension, capillary forces, and Marangoni convection. Furthermore, optical propagation and scattering of the trapping laser beyond the focus can lead to the formation of large assemblies along the interface, extending well beyond the laser beam itself. For gold nanoparticles, a single large swarming assembly forms, with individual nanoparticles exhibiting vivid fluctuations. In this study, we investigate the swarming assembly as a non-linearly evolving optical matter using a plastic microchannel. The original structure undergoes transformations into pressed, square, unidirectional, triangular, elongated rectangular, or even twisted assemblies. In addition, the photothermal effects of the optical matter are analyzed in the context of a local anisotropic heater. This phenomenon not only suggests potential applications but also offers valuable insights for advancing new technologies.

This study evaluated Candida albicans gene expression and local inflammatory response from mice with oral candidiasis that were treated with DNase I plus antimicrobial photodynamic therapy (aPDT). DNase I was applied, followed by aPDT mediated by Photodithazine® and LED light, singly or combined for five consecutive days. A group was only inoculated with fluconazole-susceptible (CaS) or-resistant (CaR) C. albicans strains. Immediately and 7 days after treatments, C. albicans colonies recovered from mice tongues were used for gene expression evaluation. Tongues from mice killed 24 h and 7 days after treatments were used to evaluate the host's inflammatory cytokines using cytometric bead array. A reduction occurred in the gene expression related to adhesion to the host substrate, the biofilm extracellular matrix, and oxidative stress of CaS and CaR recovered from mice treated with DNAse I plus aPDT. Increased production of IL-6, TNF-α, and MCP-1 occurred in mice infected with CaS but not as much for those infected with CaR in the groups treated with DNase I plus aPDT and aPDT. DNase I plus aPDT decreased the expression of the fungal genes evaluated and increased local inflammatory response, which helped to fight the infection.

Light-matter interactions are fundamental in materials fabrication and property control, with significant applications in broad fields. A notable phenomenon arises when optical forces are exerted among nanoparticles and microparticles, in which optical binding leads to the development of optical matters with a well-patterned structure. This work explores a dynamic optical matter of polystyrene microparticles (PS MPs) prepared at the air/solution interface under optical trapping, specifically focusing on the interactions between 1-µm and 20-µm PS MPs. We report the formation of an unprecedented three-dimensional (3D) bulky assembly where smaller particles form a necklace and belt assembly around the larger particle, created by multiple light scattering. The resulting assembly, which can exceed 50 µm in diameter, elongates light-matter interaction lengths and exhibits reconfigurability tuning optical conditions, forming a unique dynamic optical matter with a random and disordered structure. As a result, we demonstrate amplified spontaneous emissions in the 3D bulky assembly thanks to the feature of randomness and multiple light scattering. These findings present a new approach to the study of reconfigurable and tunable optical matter, opening avenues for novel applications in disordered photonics and material science.

Farmers are exposed chronically to solar ultraviolet radiation. Their chronically exposed skin undergoes alterations in pigmentation, but quantitative measurements have not be done yet. Therefore, we followed skin color and pigmentation in Austrian farming families (male and female farmers, their spouses, and children) for one year by objective tri-stimulus measurements on different body sites. The difference between constitutive and facultative pigmentation was quantified by the "degree-of-tan" (TAN°), which we defined as the difference in individual typology angle between constitutive and facultative pigmentation. Personal sun exposure was measured in parallel. Measurements of skin colour showed that independent of occupation, adult males had a darker red component in skin color of the forehead than adult females and children, with the highest values observed in males only. This difference develops during puberty and adolescence. Even in late winter, an obvious TAN° was found in all groups at continuously and intermittently exposed body sites. TAN° was higher in adults than in children and highest in farmers. The seasonal changes in TAN° were pronounced in all groups on intermittently exposed body sites but less so on the forehead. In conclusion, TAN° increases in farmers on average during their lifetime but not in their spouses, even though many spouses have higher TAN° than farmers of the same age. Such high TAN° is reversible if sun exposure is low in the following seasons. The highest TAN° values were found in farmers older than 50 years.

Visible-light active photocatalysts were obtained by rutile (TiO₂) high-temperature treatment in an inert argon atmosphere with addition of different amounts of melamine. The samples were characterized using X-ray diffraction, transmission and scanning electron microscopy, Fourier-transform infrared and Raman spectroscopy, UV-Vis diffuse reflectance, photoluminescence and X-ray photoelectron spectroscopy, temperature-programmed desorption of NH₃ and CO₂, and Brunauer-Emmett-Teller and thermogravimetric analysis. The effect of varying melamine amount on the crystal phase, crystallite size, and morphological and optical properties of the prepared materials was investigated. The photocatalytic activity was tested in the two types of reactions: photooxidation of dyes and photoreduction of Cr₂O₇^-2 under UV and visible-light irradiation. Rutile with the addition of melamine, annealed in an argon atmosphere, exhibited photocatalytic activity when irradiated with visible light in all the reactions studied. We explain this by a change in its morphological and optical properties, such as the formation of new surface-active centers and increased absorption in the visible range of light.