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Photochemistry and Photobiology

Tianye Wang, Shuang Zhong, Shuang Zou, Fuhuan Jiang, Limin Feng, Xiaosi Su
Novel Bi2 WO6 coupled Fe3 O4 magnetic photocatalysts with excellent and stable photocatalytic activity for degrading tetracycline hydrochloride and RhB were successfully synthesized via a facile solvothermal route. Through the characterization of the as-prepared magnetic photocatalysts by XRD, SEM, TEM, XPS, UV-vis diffuse reflectance spectra, it was found that the as-prepared magnetic photocatalysts were synthesized by the coupling of Bi2 WO6 and Fe3 O4 , and introduction of appropriated Fe3 O4 can improved nanospheres morphology and visible-light response...
February 15, 2017: Photochemistry and Photobiology
Irena Maliszewska, Barbara Lisiak, Katarzyna Popko, Katarzyna Matczyszyn
This study reports on successful photodynamic inactivation of planktonic and biofilm cells of Candida albicans using Rose Bengal (RB) in combination with biogenic gold nanoparticles synthesized by the cell-free filtrate of Penicillium funiculosum BL1 strain. Monodispersed colloidal gold nanoparticles coated with proteins were characterized by a number of techniques including SEM-EDS, TEM, UV-Vis absorption and fluorescence spectroscopy, as well as Fourier transform infrared spectroscopy to be 24±3 nm spheres coated with proteins...
February 12, 2017: Photochemistry and Photobiology
Nathalia Quintero Ruiz, Yuri Cordoba Campo, Elena E Stashenko, Jorge Luis Fuentes
The antigenotoxicity against ultraviolet radiation (UV) -induced DNA damage of essential oils (EO) from Lippia species was studied using SOS Chromotest. Based on the minimum concentration that significantly inhibits genotoxicity, the genoprotective potential of EO from highest to lowest was L. alba, citral -rich chemotype (RC) > L. graveolens, thymol-RC ≈ L. origanoides, thymol-RC ≈ L. origanoides, carvacrol-RC > L. micromera, thymol-RC ≈ L. citriodora, citral-RC > L. alba, myrcenone-RC > L...
February 8, 2017: Photochemistry and Photobiology
Mary D Boudreau, Frederick A Beland, Robert P Felton, Peter P Fu, Paul C Howard, Paul W Mellick, Brett T Thorn, Greg R Olson
Cosmetic products that contain retinyl palmitate are popular as anti-aging skin treatments; however, recent studies suggest a risk for enhanced skin tumor development with topical retinyl palmitate applications and exposure to solar ultraviolet radiation (UVR). In this study, we investigated the potential of retinyl palmitate to enhance UVR-induced photo co-carcinogenesis. Groups of 36 male and 36 female SKH-1 hairless mice were exposed to simulated solar light (SSL) and treated with the control cream or creams containing retinyl palmitate, five days per week for 40 weeks...
January 28, 2017: Photochemistry and Photobiology
Israr Ahmad, Kashiff M Muneer, Michelle E Chang, Hana M Nasr, Jacqueline M Clay, Conway C Huang, Nabiha Yusuf
Basal cell carcinomas (BCCs) account for majority of skin malignancies in the United States. The incidence of BCCs is strongly associated with exposure of ultraviolet (UV) radiation. Nucleotide-binding domain, leucine-rich-repeat-containing family, pyrin domain-containing 3 (NLRP3) inflammasome plays an important role in innate immune responses. Different stimuli such as toxins, microorganisms, and particles released from injured cells activate the NLRP3 inflammasome. Activated NLRP3 results in activation of caspase-1, which cleaves pro-IL-1β to active IL-1β...
January 25, 2017: Photochemistry and Photobiology
Arpit Dheeraj, Cynthia M Rigby, Cindy L O'Bryant, Chapla Agarwal, Rana P Singh, Gagan Deep, Rajesh Agarwal
Basal cell carcinoma (BCC) is the most common skin malignancy. Deregulated hedgehog signaling plays a central role in BCC development; therefore hedgehog inhibitors have been approved to treat locally advanced or metastatic BCC. However, the development of resistance to hedgehog inhibitors is the major challenge in effective treatment of this disease. Herein, we evaluated the efficacy of a natural agent silibinin to overcome resistance with hedgehog inhibitors (Sant-1 and GDC-0449) in BCC cells. Silibinin (25-100 μM) treatment for 48 hrs strongly inhibited growth and induced death in ASZ001, Sant-1 resistant (ASZ001-Sant-1) and GDC-0449 resistant (ASZ001-GDC-0449) BCC cells...
January 25, 2017: Photochemistry and Photobiology
Saman Hosseinkhani, Elaheh Emamgholi Zadeh, Fatemeh Sahebazzamani, Farangis Ataei, Roohullah Hemmati
Contribution of Luciferin-Regenerating Enzyme (LRE) for in vitro recycling of D-luciferin has been reported. According to crystal structure of LRE, it is a beta-propeller protein which is a type of all-β protein architecture. In this overview, reinvestigation of the luciferase-based LRE assays and its function is reported. Until now, sequence of LRE genes from 4 different species of firefly has been reported. In spite of previous reports, T-LRE (from Lampyris turkestanicus) was cloned and expressed in E...
January 25, 2017: Photochemistry and Photobiology
Xi Peng, Jie Yang, Yang Gao
UV-C's effects on the physiological and biochemical processes of cyanobacteria have been well characterized. However, the molecular mechanisms of cyanobacteria's tolerance to UV-C still needs further investigation. This research attempts to decode the variation in protein abundances in cyanobacteria after UV-C stress. Different expression levels of proteins in the cytoplasm of Synechococcus sp. PCC7942 under UV-C stress were investigated by using a comparative proteomic approach. Forty-seven UV-C-regulated proteins were identified by MALDI-TOF analysis and classified by Gene Ontology (GO)...
January 25, 2017: Photochemistry and Photobiology
Sebastian Sinnecker, Wolfgang Lubitz
In reaction centers (RCs) of photosynthesis a light-induced charge separation takes place creating radical cations and anions of the participating cofactors. In photosynthetic bacteria different bacteriochlorophylls (BChl) are involved in this process. Information about the electronic structure of the BChl radical cations and anions can be obtained by measuring the electron spin density distribution via the electron-nuclear hyperfine interaction using EPR and ENDOR techniques. In this communication we report isotropic hyperfine coupling constants (hfcs) of the BChl b and g radical cations and anions, calculated by density functional theory, and compare them with the more common radical ions of BChl a and with available experimental data...
January 25, 2017: Photochemistry and Photobiology
Jennifer K Vanos, Grant R McKercher, Kylie Naughton, Marc Lochbaum
Childhood exposure to ultraviolet radiation (UVR) is a major risk factor for the development of melanoma later in life. However, it is challenging to accurately determine personal outdoor exposure to UVR, specifically erythemally-weighted UVR (UVEry ), due to technological constraints, variable time-activity patterns, and the influence of outdoor environmental design. To address this challenge, the current study utilized mobile and stationary techniques to examine the UVEry exposures of 14 children in a schoolyard in Lubbock, TX in spring 2016...
January 18, 2017: Photochemistry and Photobiology
Maurício da Silva Baptista, Jean Cadet, Paolo Di Mascio, Ashwini A Ghogare, Alexander Greer, Michael R Hamblin, Carolina Lorente, Silvia Cristina Nunez, Martha Simões Ribeiro, Andrés H Thomas, Mariana Vignoni, Tania Mateus Yoshimura
Here, ten guidelines are presented for a standardized definition of type I and II photosensitized oxidation reactions. Because of varied notions of reactions mediated by photosensitizers, a checklist of recommendations is provided for their definitions. Type I and type II photoreactions are oxygen-dependent and involve unstable species such as the initial formation of radical cation or neutral radicals from the substrates and/or singlet oxygen ((1) O2(1) ∆g ) by energy transfer to molecular oxygen. In addition, superoxide anion radical (O2(•-) ) can be generated by a charge transfer reaction involving O2 or more likely indirectly as the result of O2 -mediated oxidation of the radical anion of type I photosensitizers...
January 13, 2017: Photochemistry and Photobiology
Luca Cevenini, Maria M Calabretta, Antonia Lopreside, Bruce R Branchini, Tara L Southworth, Elisa Michelini, Aldo Roda
Bioluminescent (BL) cell-based assays based on two-dimensional (2D) monolayer cell cultures represent well-established bioanalytical tools for pre-clinical screening of drugs. However, cells in 2D cultures do not often reflect the morphology and functionality of living organisms, thus limiting the predictive value of 2D cell-based assays. Conversely, 3D cell models have the capability to generate the extracellular matrix and restore cell-to-cell communications; thus, they are the most suitable model to mimic in vivo physiology...
January 13, 2017: Photochemistry and Photobiology
Stefan Rakete, Ram H Nagaraj
Whether ascorbate oxidation is promoted by UVA light in human lenses and whether this process is influenced by age and GSH levels are not known. In this study, we used paired lenses from human donors. One lens of each pair was exposed to UVA light whereas the other lens was kept in the dark for the same period of time as the control. Using LC-MS/MS analyses, we found that older lenses (41 to 73 years) were more susceptible to UVA-induced ascorbate oxidation than younger lenses (18 to 40 years). Approximately 36% of the ascorbate (relative to control) was oxidized in older lenses compared to ~16% in younger lenses...
January 13, 2017: Photochemistry and Photobiology
Haixia Qiu, Michele M Kim, Rozhin Penjweini, Jarod C Finlay, Theresa M Busch, Tianhao Wang, Wenshen Guo, Keith A Cengel, Charles B Simone, Eli Glatstein, Timothy C Zhu
This preclinical study examines light fluence, PDT dose, and "apparent reacted singlet oxygen", [(1) O2 ]rx , to predict local control rate (LCR) for Photofrin-mediated photodynamic therapy (PDT) of radiation-induced fibrosarcoma (RIF) tumors. Mice bearing RIF tumors were treated with in-air fluences (50-250 J/cm(2) ) and in-air fluence rates (50-150 mW/cm(2) ) at Photofrin dosages of 5 and 15 mg/kg and a drug-light interval of 24 hours using a 630nm 1-cm diameter collimated laser. A macroscopic model were used to calculate [(1) O2 ]rx and PDT dose based on in vivo explicit dosimetry of the drug concentration, light fluence, and tissue optical properties...
January 13, 2017: Photochemistry and Photobiology
Rebecca Justiniano, Joshua D Williams, Jessica Perer, Ahn Hua, Jessica Lesson, Sophia L Park, Georg T Wondrak
UVA-driven photooxidative stress in human skin may originate from excitation of specific endogenous chromophores acting as photosensitizers. Previously, we have demonstrated that 3-hydroxypyridine-derived chromophores including B6 -vitamers (pyridoxine, pyridoxamine, and pyridoxal) are endogenous photosensitizers that enhance UVA-induced photooxidative stress in human skin cells. Here, we report that the B6 -vitamer pyridoxal is a sensitizer of genotoxic stress in human adult primary keratinocytes (HEKa) and reconstructed epidermis...
January 13, 2017: Photochemistry and Photobiology
Karen A Hanley, Edith A Widder
Three major hypotheses have been proposed to explain why dinoflagellate bioluminescence deters copepod grazing: startle response, aposematic warning, and burglar alarm. These hypotheses propose dinoflagellate bioluminescence (A) startles predatory copepods, (B) warns potential predators of toxicity, and (C) draws the attention of higher-order visual predators to the copepod's location. While the burglar alarm is the most commonly accepted hypothesis, it requires a high concentration of bioluminescent dinoflagellates to be effective, meaning the bioluminescence selective advantage at lower, more commonly observed, dinoflagellate concentrations may result from another function (e...
January 7, 2017: Photochemistry and Photobiology
Natalja S Rodionova, Emilia Rota, Aleksandra S Tsarkova, Valentin N Petushkov
Even though bioluminescent oligochaetes rarely catch people's eyes due to their secretive lifestyle, glowing earthworms sighting reports have come from different areas on all continents except Antarctica. A major breakthrough in the research of earthworm bioluminescence occurred in the 1960s with the studies of the North American Diplocardia longa. Comparative studies conducted on 13 earthworm species belonging to six genera showed that N-isovaleryl-3-aminopropanal (Diplocardia luciferin) is the common substrate for bioluminescence in all examined species, while luciferases appeared to be responsible for the color of bioluminescence...
January 7, 2017: Photochemistry and Photobiology
Mary Katherine Montes de Oca, Ross L Pearlman, Sarah F McClees, Rebecca Strickland, Farrukh Afaq
Ultraviolet (UV) exposure has an array of damaging effects and is the main cause of skin cancer in humans. Non-melanoma skin cancer (NMSC), including basal cell carcinoma and squamous cell carcinoma, is the most common type of cancer. Incidence of NMSC has increased due to greater UV radiation, increased life expectancy, and other changes in lifestyle; the annual cost of skin cancer treatment in the United States has increased concurrently to around eight billion dollars. Because of these trends, novel approaches to skin cancer prevention have become an important area of research to decrease skin cancer morbidity and defray the costs associated with treatment...
January 7, 2017: Photochemistry and Photobiology
Qian Gao, Fang Wang, Liwen Hu, Jiaming Yu, Rong Liu, Yang Wang, Yang Liu
Changes in time-activity patterns may influence personal exposure to various environmental factors and affect individual health. However, few studies have investigated the changes in patterns of time spent outdoors. To investigate the trends in outdoor activity in recent decades in China, a retrospective questionnaire was used to examine the amount and pattern of time spent outdoors during the day by 2076 subjects in four geographically distinct rural regions of China. Rural Chinese people spent less time outdoors than they used to because of the economic development, increase in education, and changes in working conditions that occurred over time...
January 7, 2017: Photochemistry and Photobiology
Vasilisa V Krasitskaya, Ludmila P Burakova, Anastasia A Komarova, Eugenia E Bashmakova, Ludmila A Frank
Color variants of Ca(2+) -regulated photoprotein obelin were shown to be an important tool for dual-analyte binding assay. To provide site-directed conjugation with biospecific molecules, several obelin color mutants carrying unique cysteine residues were obtained and characterized for their novel properties. A pair of obelins Y138F,A5C and W92F,H22E,D12C was found to be most suitable (in terms of high bioluminescent activity and stability) as reporters in simultaneous assay of two targets in a sample. Availability of SH-groups, accessible for chemical modification essentially simplifies the synthesis of biospecific conjugates, increases their yield and conserves obelins' bioluminescence activity...
January 7, 2017: Photochemistry and Photobiology
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