The Playground Shade Index: A New Design Metric for Measuring Shade and Seasonal Ultraviolet Protection Characteristics of Parks and Playgrounds
AbstractCurrent shading strategies used to protect outdoor playgrounds from harmful solar radiation include the placement of artificial cloth weaves or permanent roofing over a playground site, planting trees in proximity to playground equipment, and using vegetation or surface texture variations to cool playground surfaces. How and where an artificial shade structure is placed or a tree is planted to maximize the shade protection over specific playground areas, requires careful assessment of local seasonal sun exposure patterns. The Playground Shade Index (PSI) is introduced here as a design metric to enable shade and sol...
Source: Photochemistry and Photobiology - November 21, 2022 Category: Science Authors: Nathan Downs,
Nawin Raj,
Jennifer Vanos,
Alfio V. Parisi,
Harry Butler,
Ravinesh Deo,
Damien Igoe,
Benjamin Dexter,
Melanie Beckman ‐Downs,
Joanna Turner,
Stijn Dekeyser Tags: Method Article Source Type: research
Amount of Melanin Granules in Human Hair Defines the Absorption and Conversion to Heat of Light Energy in the Visible Spectrum
AbstractOne of the known important functions of hair is protection from extensive sunlight. This protection is accomplished in large part due to natural hair pigmentation which is known to reflect the number of melanin granules (melanosomes) in the hair shaft, and melanin variants. Melanin takes in excessive light energy and converts it to heat in a process called absorption; heat is then dissipated into the environment as infrared radiation, thereby protecting the underlying skin. We used transmission electron microscopy (TEM) to visualize the melanosome counts in samples of human hair, and used thermal microscopy to meas...
Source: Photochemistry and Photobiology - November 20, 2022 Category: Science Authors: Joshua Roldan ‐Kalil,
Lidia Zueva,
Janaina Alves,
Vassiliy Tsytsarev,
Priscila Sanabria,
Mikhail Inyushin Tags: Research Article Source Type: research
Issue Information
(Source: Photochemistry and Photobiology)
Source: Photochemistry and Photobiology - November 11, 2022 Category: Science Tags: Issue Information Source Type: research
Biological Impact of Shorter Wavelength Ultraviolet Radiation ‐C
AbstractLife on earth has constantly coped with the impact of solar radiation, especially solar ultraviolet radiation (solar UV). Various biological mechanisms protect us from solar UV. New devices emitting shorter wavelengths UV-C, i.e.,<254 nm emitted by conventional UV germicidal lamps, have emerged. These shorter wavelength UV-C emitting devices are useful for various purposes, including microorganism inactivation. However, since solar UV-C does not reach the earth surface, biological impacts of UV-C has been studied by using 254 nm-germicidal lamps, and those by using shorter wavelength UV-C is rarely known. To bal...
Source: Photochemistry and Photobiology - November 10, 2022 Category: Science Authors: Chikako Nishigori,
Nozomi Yamano,
Makoto Kunisada,
Aiko Nishiaki ‐Sawada,
Hiroyuki Ohashi,
Tatsushi Igarashi Tags: Special Issue Invited Review Source Type: research
Diketopyrrolopyrrole Derivatives as Photosensitizing Agents against Staphylococcus Aureus
AbstractDiketopyrrolopyrrole (DPP) derivatives containing sulfonamide (Sulfonamide-DPP), pyridyl (Dipyridyl-DPP) andN-methylpyridyl (MePyridyl-DPP) substituents were assessed as antibacterial photosensitizers. Non-charged DPPs showed an intense absorption band centered at about 480 nm and green fluorescence emission ( ΦF ~ 0.7) in acetonitrile. The absorption ofMePyridyl-DPP was bathochromically shifted at 510 nm, with decreased fluorescence emission.Sulfonamide-DPP andDipyridyl-DPP photosensitized the formation of O2(1Δg) ( ΦΔ ~ 0.15−0.17), while the production induced byMePyridyl-DPP was at least 10 times low...
Source: Photochemistry and Photobiology - November 7, 2022 Category: Science Authors: Mar ía E. Pérez,
Vitor A. S. Almodovar,
Javier E. Durantini,
Natalia S. Gsponer,
Andrés M. Durantini,
Augusto C. Tomé,
Edgardo N. Durantini Tags: Research Article Source Type: research
Pyrroloquinolones, a New Platform for Developing Organic Photosensitizers: When Synthetic Methodology Meets Photophysics
AbstractNew molecular architectures with triplet sensitization properties can have a big impact in photochemistry and photobiology. In their recent work, de Bonfilset al. have tackled this challenge in a very systematic way using a powerful synthetic strategy. This consists in an elegant yet practical organocatalyzed cyclization/oxidation rearrangement sequence which they now apply to the synthesis of pyrroloquinolones, a new scaffold for photosensitizers. However, beyond this new class of compounds, the strategy has potential to produce a myriad of compact organic chromophores with promising photoinduced intersystem cross...
Source: Photochemistry and Photobiology - November 6, 2022 Category: Science Authors: Zacharias Amara Tags: Highlight Article (Invited) Source Type: research
Far ‐UVC Light at 222 nm is Showing Significant Potential to Safely and Efficiently Inactivate Airborne Pathogens in Occupied Indoor Locations
This article reviews both the safety of far-UVC, which has a clear mechanistic underpinning, and its efficacy, both in the laboratory and in full-sized rooms. Highlighted is the paper by Maet al. in this issue ofPhotochemistry and Photobiology which addresses the efficacy of far-UVC light (in this case at 222 nm) against a broad spectrum of common pathogens including SARS-CoV-2 and influenza viruses. From their data, and based on our understanding of the largely random nature of UVC-induced damage within the genome, far UVC would be expected to be effective against the next pandemic virus, if and when it emerges. (Source: ...
Source: Photochemistry and Photobiology - November 5, 2022 Category: Science Authors: David J. Brenner Tags: Highlight Article (Invited) Source Type: research
A Lock ‐and‐Kill Anticancer Photoactivated Chemotherapy Agent
AbstractPhotosubstitutionally active ruthenium complexes show high potential as prodrugs for the photoactivated chemotherapy (PACT) treatment of tumors. One of the problems in PACT is that the localization of the ruthenium compound is hard to trace. Here, a ruthenium PACT prodrug, [Ru(3)(biq)(STF-31)](PF6)2, (where3 = 3-([2,2’:6’,2”-ter- pyridin]-4’-yloxy)propyl-4-(pyren-1-yl)butanoate) and biq = 2,2’-biquinoline), has been prepared, in which a pyrene tracker is attachedvia an ester bond. The proximity between the fluorophore and the ruthenium center leads to fluorescence quenching. Upon hydrolysis of the es...
Source: Photochemistry and Photobiology - October 31, 2022 Category: Science Authors: E. P. Geest,
S. K. G ötzfried,
D. M. Klein,
N. Salitra,
S. Popal,
Y. Husiev,
C. Van der Griend,
X. Zhou,
M. A. Siegler,
G. F. Schneider,
S. Bonnet Tags: Special Issue Research Article Source Type: research
Insights into the Ultrafast Photodissociation Dynamics of Isoprene Derived Criegee Intermediates
AbstractIsoprene is the most abundant non-methane volatile organic compound emitted into the troposphere by terrestrial vegetation. Reaction with ozone represents an important isoprene removal process from the troposphere and is a well-known source of Criegee intermediates (CIs), which are reactive carbonyl oxides. Three CIs, formaldehyde oxide (CH2OO), methyl vinyl ketone oxide (MVK-oxide), and methacrolein oxide (MACR-oxide) are formed during isoprene ozonolysis. All three CIs contain strongly absorbing ππ* states, electronic excitation to which leads to dissociation to form aldehyde/ketone + oxygen products. Here, we ...
Source: Photochemistry and Photobiology - October 30, 2022 Category: Science Authors: Ernest Antwi,
Niamh A. Packer,
Jordyn M. Ratliff,
Barbara Marchetti,
Tolga N. V. Karsili Tags: Research Article Source Type: research
Exposed Body Surface Area – A determinate for UV Radiant Energy in Human UV Exposure studies
AbstractSolar ultraviolet (UV) exposure of people and related health risk is mainly examined by estimating the received UV radiant exposure. However, for several effects such as DNA-damage, vitamin D photosynthesis or the probability of developing skin cancer, UV radiant energy is important and with that the size of exposed skin area. There is also a complex interaction between body shape and behavior like sun exposure habits, so that careful analysis is necessary when estimating health effects from UV exposure. In this paper, knowledge on body shape and methods of calculating the total body surface area (BSA) are summariz...
Source: Photochemistry and Photobiology - October 29, 2022 Category: Science Authors: Alois W. Schmalwieser,
Susanne S. Schmalwieser Tags: Invited Review Source Type: research
Solar Light Responsive Graphitic Carbon Nitride Coupled Porphyrin Photocatalyst that Uses for Solar Fine Chemical Production
AbstractPhotocatalysis is a defendable manner for production of several organic chemicals, energy, and its storage from solar energy. For the evolution of metal free, cost-effective catalyst a 2D composite has been appear as a photocatalyst. Here, we had reported the synthesis of a light harvesting composite as a photocatalyst which was assembled by a poly-condensation mechanism between graphitic carbon nitride and tetrakis(4nitrophenyl) porphyrin and the resulting composite manifest the excellent light harvesting properties, suitable energy band and low charge recombination. The photocatalyst [(NO2)4TPP@g-C3N4] enables th...
Source: Photochemistry and Photobiology - October 23, 2022 Category: Science Authors: Shaifali Mishra,
Rajesh K Yadav,
Satyam Singh,
Surabhi Chaubey,
Pooja Singh,
Chandani Singh,
Sarvesh Kumar Gupta,
Shivani Gupta,
Dhanesh Tiwary,
Tae Wu Kim Tags: Research Article Source Type: research
Benzo[A]Pyrene and Benzo[E]Pyrene: Photoreactivity and Phototoxicity toward Human Keratinocytes
In this study, quantum yield and action spectra of singlet oxygen photogeneration by BaP and BeP were measured by time-resolved near-infrared phosphorescence, and the ability of both compounds to photogenerate superoxide anion was assessed by electron paramagnetic resonance (EPR) spin-trapping. The measurements revealed high efficiency of benzopyrenes to photogenerate singlet oxygen and their ability to photogenerate superoxide anion. Using HaCaT cells as single-layer skin model, we demonstrated concentration-dependent and light-dependent cytotoxicity of BaP and BeP. The compounds induced damage to the cell mitochondria an...
Source: Photochemistry and Photobiology - October 20, 2022 Category: Science Authors: Krystian Mokrzy ński,
Grzegorz Szewczyk,
Tadeusz Sarna Tags: Research Article Source Type: research
UV Inactivation of Common Pathogens and Surrogates Under 222 nm Irradiation from KrCl* Excimer Lamps
This study provides fundamental information for pathogen disi nfection when employing KrCl* excimers. (Source: Photochemistry and Photobiology)
Source: Photochemistry and Photobiology - October 20, 2022 Category: Science Authors: Ben Ma,
Kelly Bright,
Luisa Ikner,
Christian Ley,
Saba Seyedi,
Charles P. Gerba,
Mark D. Sobsey,
Patrick Piper,
Karl G. Linden Tags: Research Article Source Type: research
Singlet Oxygen's Potential Role as a Nonoxidative Facilitator of Disulfide S –S Bond Rotation
A density functional theory study provides evidence that singlet oxygen binds to 1,2-dimethyldisulfane to form a peroxy intermediate. Mechanistic detail is provided for the singlet oxygen reaction, where a reduced energy for rotation about the S–S bond is found prior to departure of molecular oxygen. Notably, this disulfide O2-capture and release reaction is reminiscent of alkenes and polyenes that form peroxy intermediates, thereby facilitating their cis-trans isomerizations. AbstractThe role of singlet oxygen potentially mediating increased conformational flexibility of a disulfide was investigated. Density function...
Source: Photochemistry and Photobiology - October 19, 2022 Category: Science Authors: Oliver Turque,
Ryan M. O'Connor,
Alexander Greer Tags: Special Issue Research Article Source Type: research
Senolytic Drug Quercetin Rescues Survival from Blue Light Toxicity in Drosophila Model
In this study, Drosophila melanogaster was used as a model organism to investigate the protective effect of the senolytic drug quercetin on blue light toxicity. As one of the first senolytic drugs discovered, quercetin not only has antioxidant properties, but also has been used to treat various neurological disorders. Our study shows that quercetin can effectively prolong the survival of flies under blue light irradiation, and it significantly increases the egg production of female flies under blue light. In addition, after flies intaking quercetin under blue light, both the spontaneous activity and nutrient metabolism sho...
Source: Photochemistry and Photobiology - October 19, 2022 Category: Science Authors: Dake Zhang,
Jianying Shan,
Boying Liang,
Lichao Zhong,
Hao Tang,
Yifan Xu,
Hui Jin,
Yinfei Chen,
Jie Shen Tags: Research Article Source Type: research
