Journal of Photochemistry and Photobiology最新文献

Photobiomodulation (PBM) is a noninvasive photonic-based therapy, capable of dealing with immune-inflammatory, neurological, and musculoskeletal disorders, as well as healing oral and chronic skin wounds. During PBM light is applied at a specific wavelength, either in the visible or near-infrared (NIR) ranges. Photophysical and photochemical processes might stimulate or inhibit various biological processes, depending on the target tissue, the wavelength of light, irradiance, fluence, repetition rate (pulse frequency), spot size, optical data of the tissue to be irradiated and treatment regimen. There are several randomized clinical studies demonstrating the PBM benefits as main or adjuvant therapies. Of importance to this review, there is a large piece of evidence in the management of skin or venous ulcers, and diabetic foot. In this review, the PBM´s efficacy as adjuvant therapy to deal with chronic human ulcers were discussed concerning the photophysical parameters and clinical aspects. Beside, we overview the state-of-the-art regarding the cellular and molecular modulatory mechanisms photoactivated by red and NIR light.

The present work investigates the disinfection of dialysate water used in hemodialysis through the application of bioinspired W/WO₃ electrodes constructed on microbial biofilm from C. parapsilosis by electrochemical anodization. The bioinspired electrode was photoactivated by UV/Vis or visible irradiation, and the photocurrent was found to be at least twice higher than that obtained for nanoporous W/WO₃ electrode in the dialysate water. Under optimized conditions, the photo-electrocatalytic analysis conducted on the bioinspired electrode at E_app = 1.5 V and under UV/Vis irradiation led to complete fungi inactivation (5 min) and up to 70% of total organic carbon removal monitored during cell lysis after 120 min of treatment. The results show the bioinspired electrode maintains the structural print of the fungi and works as fungus recognition material. The proposed electrode is also found to exhibit higher surface area, which improves adsorption of microorganisms, leading to faster and more efficient degradation compared to nanoporous W/WO₃ electrode, with a 30% increase in the degradation of organic matter present in the medium. The findings show that the bioinspired electrode has outstanding advantages when compared with other materials investigated; these advantages include controlled morphology, good reproducibility, higher adsorption on the electrode surface, and higher efficiency in the disinfection of C. parapsilosis, an agent of several cases of contamination in dialysate.

Photoelectrochemical (PEC) water splitting is an emerging technology to store the solar energy in the chemical bonds of molecular hydrogen. Among several photo electrodes used for PEC water splitting, α-Fe₂O₃ is a promising material due to its suitable bandgap, chemical stability, and abundance. Despite these, the position of its conduction band does not allow spontaneous movement of photo-generated electrons to cause the water reduction. This demands the application of a minimum electrical bias of ∼1.5 V vs. SHE to increase the energy of the conduction band such that it will be energetically above the H₂O/H₂ redox level. We show that by utilizing the energy of neutralization, the minimum electrical voltage required for PEC water splitting can be brought down to ∼0.8 V. By employing an OH⁻/H⁺dual-ion configuration. OH⁻/H⁺dual-ion assisted PEC water splitting required only 0.95 V to produce a current density of 10 mA/cm², and for achieving the same rate in a conventional symmetric ion configuration, at least a doubling of the applied electrical bias (∼1.8 V) is required.

Hole-transport materials (HTMs) contribute an important function in perovskite solar cells (PSCs) for achieving favourable photovoltaic performance with durability. In this work, we designed and synthesized a series of porphyrin based hydrophobic HTMs based on donor-π-donor (D-π-D) tactic in which triphenylimidazole as donor and either free-base porphyrin (H2LD) or metalloporphyrin (Cu, CuLD or Zn, ZnLD) as π-spacer for PSCs. All three HTMs were characterized by a variety of spectroscopic and electrochemical methods. Optical and electrochemical properties propose that the highest occupied molecular orbital (HOMO) energy levels were healthily aligned with the valence band of MAPbI₃ perovskite. Among these HTMs, CuLD exhibited higher hole mobility of 7.39 × 10^-5 cm²V^-1s^-1, when compared to ZnLD 5.77 × 10^-5 cm²V^-1s^-1, and H2LD 2.7 × 10^-5 cm²V^-1s^-1. We fabricated PSCs with these HTMs and among them the CuLD based PSCs showed highest power conversion efficiency of 12.44%. The better PCE for the PSCs fabricated with CuLD could be attributed to the higher conductivity and better hole mobility which could be correlated to the better film formation.

We have demonstrated three LY-HTMs for perovskite solar cells in this report. These LY-HTMs embed cyclopentadithiophene (CPT) core that incorporates 2∼4 triphenylamine electron donor units. Designing LY-HTMs with Lewis-basic property of carbonyl or imine, can effectively passivate the defects of insufficiently coordinated Pb²⁺ in the perovskite layer. The LY-HTMs have good thermal stability and enhanced intermolecular interaction, thereby dense packing, due to the sulfur-sulfur interaction in the dithiophene structure. Moreover, the sulfur-sulfur interaction achieves a deeper HOMO energy level that can be well-matched to perovskite solar cells (PSCs). It also improves the charge mobility to enhance Voc and Jsc values. The best performance using LY-1 as a HTM in PSCs exhibited a Jsc of 23.1 mA∙cm⁻², a Voc of 1.06 V, and a fill factor of 0.78, corresponding to an overall conversion efficiency of 19.12% (the control device of spiro-OMeTAD, 17.69%). In addition, the PCEs of the LY-1 PSC devices underwent decays of only 90% and 74.8% of their original values after 10 and 30 days, respectively, under an Ar atmosphere.

Electron donor–acceptor (EDA) complexes are interesting chemical species that function as molecular complexes. In this context, chemists have actively studies the use of halogen bonding as a noncovalent interaction in photochemistry. This study focused on developing a direct arylation reaction using aryl radicals generated by photoinduced electron transfer (PET) through halogen-bonding interactions. The study also involves optimizing reaction conditions for a photo induced direct arylation reaction using phenols as halogen bonding acceptor and plausible reaction mechanism. Our results demonstrated that this method provides a facile and efficient approach for synthesizing complex biaryls containing heteroarens using readily available heteroarenes.

This review presents the main metrics developed so far to correlate physical properties of light and its effects on melatonin suppression. Melatonin is a hormone secreted at night and its production is suppressed by exposure to light. In this context, the negative effects of lighting at night and high exposure to light raise the need for a better quantification of these impacts on health. Different light action spectroscopy methodologies have been recently used to characterize the circadian response mediated by melatonin in humans, but there is so far no consensus on a main validated model. While complementary studies are still necessary to reach such an ideal model, here we analyze and compare the results of works that developed and tested metrics based on the absorption curves of human melanopsin, rods and cones, and on the dynamics of melatonin suppression in different light regimes. These studies reveal how the spectral composition, irradiance and temporality of light modulate the function of human melatonin. We present milestones in this research field, together with discussion on the advances, limitations and perspectives of application for distinct available models. Applied to different contexts, this knowledge can bring favorable changes to health in environmental lighting projects, production of ophthalmic lenses, screens, filters, films, and other optical devices.

Photocatalytic systems consisting of 2-substituted benzimidazoliums (BI⁺–R, R = polycyclic aryl, triarylamine or phenyl-sulfate) and stoichiometric hydride donor reagents were developed. Light emitting diode irradiation of these photocatalysts in the presence of NaBH₄ or picoline borane promotes desulfonylation reactions of an N-sulfonyl indole, N-sulfonyl amide and α-sulfonyl ketone. Absorption spectroscopic and redox potential measurements as well as density functional theory calculations were carried out to gain mechanistic information. Benzimidazolines (BIH–R), generated in situ by hydride reduction of BI⁺–R, serve as both an electron and hydrogen atom donor photocatalysts in these reductive desulfonylation reactions, which contrasts to ordinary reducing photocatalysts that simply donate electrons.

Mammals use social thermoregulation to maintain the core body temperature (Tc) at a lower energy cost. Brown adipose tissue (BAT) plays a crucial role in thermoregulation. This study tested the hypothesis that social isolation induces alterations in thermogenesis and metabolism to maintain the rhythm of Tc throughout the day. Adult male mice (C57BLJ/6) were maintained in groups of 4–5 (group-housed) or isolated (single-housed) for 28 days. Telemetric probes recorded spontaneous locomotor activity (SLA) and Tc to analyze SLA and Tc daily rhythms. Body weight was measured weekly. VO2 consumption was analyzed at zeitgeber time (ZT) 1–3 (beginning of light phase) or ZT10–14 (beginning of dark phase). The expression of thermogenic-related and clock genes in the BAT occurred at ZT2, ZT8, ZT14, and ZT20. The β3 adrenergic agonist CL-316,243 was i.p. injected in the group- or single-housed mice. Social isolation increased the amplitude of Tc rhythm but decreased the amplitude of SLA oscillation. Nevertheless, in single-housed mice, the circadian peak of Tc and SLA was unaltered, with reduced body weight gain, increased VO2 consumption, and BAT Ucp1 expression at ZT14. Isolation advanced the BAT Rev-erb-ɑ peak of expression and phased-shift the peak of expression in BAT Bmal1, while it abolished the daily BAT Per2 oscillation. Isolation also abolished the BAT Ucp1 and hormone-sensitive lipase (Hsl) expression induced by stimulation of the β3ADR, but it increased Rev-erb-ɑ and Pgc1α. Thus, alterations in Ucp1, Reverb-α, Bmal1, and Per2 daily expression may favor an increased metabolic rate at the beginning of the dark, which, in turn, contributes to maintaining the daily Tc rhythm at the expense of reduced body weight gain in isolated mice. In addition, at least at the transcription level, the response of BAT from isolated mice to adrenergic agonist seems to be via a non-canonical mechanism involving Rev-erb-α and Pgc1α.

The electron transfer reaction between C₆₀ and SWCNTs in D₂O was investigated. Repeated laser irradiation of water-soluble C₆₀ encapsulated in γ-cyclodextrin and SWCNTs with carboxymethylcellulose dispersed in D₂O resulted in the accumulation of C₆₀ anion radicals and a decrease in the E₁₁ absorption band of SWCNTs, strongly suggesting electron transfer between C₆₀ and SWCNTs. Transient absorption techniques revealed that this electron transfer occurred through the excited triplet of C₆₀.