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https://www.readbyqxmd.com/read/28513845/claud-s-rupert-1919-2017-the-father-of-dna-repair
#1
Aziz Sancar
Claud Stanley Rupert Jr, a founding father of the field of DNA repair, died of natural causes in Dallas, Texas, on February 2(nd) , 2017. Dr. Rupert was highly respected by the photobiology and DNA repair communities. In 1964, he received the Finsen Medal, the highest recognition given by International Union of Photobiology. He was elected to the American Association for the Advancement of Science in 1966. In 1971, he was named to the Johns Hopkins University Society of Scholars. This article is protected by copyright...
May 17, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28500709/the-expanded-red-green-cyanobacteriochrome-lineage-an-evolutionary-hot-spot
#2
Keiji Fushimi, Masahiko Ikeuchi, Rei Narikawa
This article highlights the paper by Rockwell et al. in the current issue of Photochemistry and Photobiology. Rockwell et al. describe the discovery of novel two-Cys photocycles within the "expanded red/green" (XRG) cyanobacteriochrome (CBCR) lineage. Comprehensive phylogenetic analysis revealed that several XRG CBCRs possess a second Cys residue in the DXCF (Asp-Xaa-Cys-Phe) motif conserved among the DXCF CBCR lineage. Spectral studies identified that these CBCRs showed green/blue or ultraviolet/blue reversible photoconversion abilities...
May 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28480921/electronic-relaxation-pathways-of-the-biologically-relevant-pterin-chromophore
#3
R M DiScipio, R Y Santiago, D Taylor, C E Crespo-Hernández
Pterin derivatives are endogenous photosensitizers common to every biological kingdom and are involved in numerous photobiological processes for which they have received widespread attention. Despite the photobiological relevance of the pterin compounds, their excited-state dynamics have not been investigated rigorously-an undertaking that must begin with a thorough understanding of the photophysics of the common core chromophore, 2-amino-1H-pteridin-4-one (a.k.a. pterin). In this contribution, direct observation of the ultrafast excited-state dynamics of pterin in aqueous borate buffered solution at pH 10...
May 8, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28463378/the-photochemistry-and-photobiology-of-vitamin-b12
#4
Alex R Jones
Biologically active derivatives of vitamin B12 are organometallic cobalt-corrinoid complexes crucial for the healthy function of humans, animals and microbes. Their role as cofactors to numerous, thermally-driven metabolic enzymes is well described, and varies depending on the nature of the upper axial ligand. This ligand also significantly influences the photophysics and photochemistry of B12. In this Perspective I will discuss the various aspects of B12 photochemistry, from its dynamic spin chemistry to the considerable potential it has for biotechnology applications...
May 2, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28386667/dynamic-modeling-of-temperature-change-in-outdoor-operated-tubular-photobioreactors
#5
Dominic Deo Androga, Basar Uyar, Harun Koku, Inci Eroglu
In this study, a one-dimensional transient model was developed to analyze the temperature variation of tubular photobioreactors operated outdoors and the validity of the model was tested by comparing the predictions of the model with the experimental data. The model included the effects of convection and radiative heat exchange on the reactor temperature throughout the day. The temperatures in the reactors increased with increasing solar radiation and air temperatures, and the predicted reactor temperatures corresponded well to the measured experimental values...
April 6, 2017: Bioprocess and Biosystems Engineering
https://www.readbyqxmd.com/read/28383082/outstanding-reviewers-for-photochemical-photobiological-sciences-in-2016
#6
EDITORIAL
(no author information available yet)
No abstract text is available yet for this article.
April 6, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28370264/novel-osmium-based-coordination-complexes-as-photosensitizers-for-panchromatic-photodynamic-therapy
#7
Savo Lazic, Pavel Kaspler, Ge Shi, Susan Monro, Tariq Sainuddin, Sarah Forward, Kamola Kasimova, Robie Hennigar, Arkady Mandel, Sherri McFarland, Lothar Lilge
Cancer remains a major global malaise requiring the advent of new, efficient, and low-cost treatments. Photodynamic therapy, which combines a photosensitizer and photons to produce cytotoxic reactive oxygen species, has been established as an effective cancer treatment but has yet to become mainstream. One of the main limitations has been the paucity of photosensitizers that are effective over a wide range of wavelengths, can exert their cytotoxic effects in hypoxia, are easily synthesized, and produce few if any side effects...
April 3, 2017: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/28341348/the-impact-of-oral-polypodium-leucotomos-extract-on-ultraviolet-b-response-a-human-clinical-study
#8
Indermeet Kohli, Rubina Shafi, Prescilia Isedeh, James L Griffith, Mohammed S Al-Jamal, Narumol Silpa-Archa, Bradford Jackson, Mohammed Athar, Nikiforos Kollias, Craig A Elmets, Henry W Lim, Iltefat H Hamzavi
BACKGROUND: There is a rationale for adding systemic photoprotective agents to the current photoprotection regimen. OBJECTIVE: This study was designed to objectively evaluate the molecular and photobiologic effects of oral administration of Polypodium leucotomos extract (PLE). METHODS: In all, 22 subjects with Fitzpatrick skin phototype I to III were enrolled. On day 1, subjects were irradiated with visible light, ultraviolet (UV) A1, and UVB (using 308-nm excimer laser)...
March 21, 2017: Journal of the American Academy of Dermatology
https://www.readbyqxmd.com/read/28329062/comparison-of-demographic-and-photobiological-features-of-chronic-actinic-dermatitis-in-patients-with-lighter-vs-darker-skin-types
#9
Ki-Wei Tan, Ann K Haylett, Tsui C Ling, Lesley E Rhodes
Importance: Chronic actinic dermatitis (CAD) is classically described in older, white men, although increasing reports describe younger patients with darker skin types, particularly South Asians. Photocontact allergy occurs in CAD but is less studied than contact allergy in this exquisitely photosensitive condition. Objective: To evaluate for differences in demographic and photobiological features between persons with darker and lighter skin types who have CAD. Design, Setting, and Participants: This retrospective review included 70 consecutive adult patients (≥18 years) undergoing investigation for photosensitivity who were diagnosed with CAD from November 1, 2000, through August 31, 2015, at the specialist Photobiology Unit of a tertiary academic referral center...
March 22, 2017: JAMA Dermatology
https://www.readbyqxmd.com/read/28322269/a-ras-gtpase-associated-protein-is-involved-in-the-phototropic-and-circadian-photobiology-responses-in-fungi
#10
Silvia Polaino, José M Villalobos-Escobedo, Viplendra P S Shakya, Alejandro Miralles-Durán, Suman Chaudhary, Catalina Sanz, Mahdi Shahriari, Eva M Luque, Arturo P Eslava, Luis M Corrochano, Alfredo Herrera-Estrella, Alexander Idnurm
Light is an environmental signal perceived by most eukaryotic organisms and that can have major impacts on their growth and development. The MadC protein in the fungus Phycomyces blakesleeanus (Mucoromycotina) has been postulated to form part of the photosensory input for phototropism of the fruiting body sporangiophores, but the madC gene has remained unidentified since the 1960s when madC mutants were first isolated. In this study the madC gene was identified by positional cloning. All madC mutant strains contain loss-of-function point mutations within a gene predicted to encode a GTPase activating protein (GAP) for Ras...
March 21, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28316830/crystal-structure-of-a-photobiologically-active-brominated-angular-pyran-ocoumarin-bromo-hy-droxy-seselin
#11
A K Bauri, Sabine Foro, A F M Mustafizur Rahman
The title compound, C14H13BrO3 [systematic name: rac-(9S,10R)-9-bromo-10-hy-droxy-8,8-dimethyl-9,10-di-hydro-2H,8H-pyrano[2,3-f]chromen-2-one], is a substituted pyran-ocoumarin, obtained by bromination of seselin [8,8-dimethyl-2H,8H-pyrano[2,3-f]chromen-2-one], which was isolated from the Indian herb Trachyspermum stictocarpum (Aajmod). The pyrano ring has a distorted half-chair conformation and its mean plane is inclined to the coumarin mean plane by 1.6 (2)°. In the crystal, mol-ecules are linked by pairs of O-H⋯O hydrogen bonds, forming inversion dimers with an R(2)2(16) ring motif...
March 1, 2017: Acta Crystallographica. Section E, Crystallographic Communications
https://www.readbyqxmd.com/read/28301148/synthesis-and-photobiological-activity-of-ru-ii-dyads-derived-from-pyrrole-2-carboxylate-thionoesters
#12
Deborah A Smithen, Huimin Yin, Michael H R Beh, Marc Hetu, T Stanley Cameron, Sherri A McFarland, Alison Thompson
The synthesis and characterization of a series of heteroleptic ruthenium(II) dyads derived from pyrrole-2-carboxylate thionoesters are reported. Ligands bearing a conjugated thiocarbonyl group were found to be more reactive toward Ru(II) complexation compared to analogous all-oxygen pyrrole-2-carboxylate esters, and salient features of the resulting complexes were determined using X-ray crystallography, electronic absorption, and NMR spectroscopy. Selected complexes were evaluated for their potential in photobiological applications, whereupon all compounds demonstrated in vitro photodynamic therapy effects in HL-60 and SK-MEL-28 cells, with low nanomolar activities observed, and exhibited some of the largest photocytotoxicity indices to date (>2000)...
April 3, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28263079/%C3%AF-expansive-heteroleptic-ruthenium-ii-complexes-as-reverse-saturable-absorbers-and-photosensitizers-for-photodynamic-therapy
#13
Li Wang, Huimin Yin, Mohammed A Jabed, Marc Hetu, Chengzhe Wang, Susan Monro, Xiaolin Zhu, Svetlana Kilina, Sherri A McFarland, Wenfang Sun
Five heteroleptic tris-diimine ruthenium(II) complexes [RuL(N^N)2](PF6)2 (where L is 3,8-di(benzothiazolylfluorenyl)-1,10-phenanthroline and N^N is 2,2'-bipyridine (bpy) (1), 1,10-phenanthroline (phen) (2), 1,4,8,9-tetraazatriphenylene (tatp) (3), dipyrido[3,2-a:2',3'-c]phenazine (dppz) (4), or benzo[i]dipyrido[3,2-a:2',3'-c]phenazine (dppn) (5), respectively) were synthesized. The influence of π-conjugation of the ancillary ligands (N^N) on the photophysical properties of the complexes was investigated by spectroscopic methods and simulated by density functional theory (DFT) and time-dependent DFT...
March 6, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28260501/in-vitro-skin-models-for-the-evaluation-of-sunscreen-based-skin-photoprotection-molecular-methodologies-and-opportunities
#14
Françoise Bernerd, Claire Marionnet
Identifying and understanding the biological events that occur following ultraviolet (UV) exposure are mandatory to elucidate the biological and clinical consequences of sun exposure, and to provide efficient and adequate photoprotection strategies. The main UV-induced biological features (markers related to sunburn, cancer, photoaging immunosuppression, pigmentation), characterized in human skin in vivo, could be reproduced in adapted models of reconstructed skin in vitro, attesting their high relevance in the field of photobiology...
March 3, 2017: Current Medicinal Chemistry
https://www.readbyqxmd.com/read/28245932/characterisation-of-a-smartphone-image-sensor-response-to-direct-solar-305nm-irradiation-at-high-air-masses
#15
D P Igoe, A Amar, A V Parisi, J Turner
This research reports the first time the sensitivity, properties and response of a smartphone image sensor that has been used to characterise the photobiologically important direct UVB solar irradiances at 305nm in clear sky conditions at high air masses. Solar images taken from Autumn to Spring were analysed using a custom Python script, written to develop and apply an adaptive threshold to mitigate the effects of both noise and hot-pixel aberrations in the images. The images were taken in an unobstructed area, observing from a solar zenith angle as high as 84° (air mass=9...
February 25, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28213283/pyrrolo-3-2-6-7-cyclohepta-1-2-b-pyridines-with-potent-photo-antiproliferative-activity
#16
Virginia Spanò, Daniele Giallombardo, Vincenzo Cilibrasi, Barbara Parrino, Anna Carbone, Alessandra Montalbano, Ilaria Frasson, Alessia Salvador, Sara N Richter, Filippo Doria, Mauro Freccero, Stella Cascioferro, Patrizia Diana, Girolamo Cirrincione, Paola Barraja
Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines were synthesized as a new class of tricyclic system in which the pyridine ring is annelated to a cycloheptapyrrole scaffold, with the aim of obtaining new photosensitizing agents with improved antiproliferative activity and lower undesired toxic effects. A versatile synthetic pathway was approached, which allowed the isolation of derivatives of the title ring system with a good substitution pattern on the pyrrole moiety. Photobiological studies revealed that the majority of the new compounds showed a potent cytotoxic effect upon photoactivation with light of the proper wavelength, especially when decorated with a 2-ethoxycabonyl group and a N-benzyl substituted moiety, with EC50 values reaching the submicromolar level...
March 10, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28211524/epigenetic-and-genetic-dissections-of-uv-induced-global-gene-dysregulation-in-skin-cells-through-multi-omics-analyses
#17
Yao Shen, Milda Stanislauskas, Gen Li, Deyou Zheng, Liang Liu
To elucidate the complex molecular mechanisms underlying the adverse effects UV radiation (UVR) on skin homeostasis, we performed multi-omics studies to characterize UV-induced genetic and epigenetic changes. Human keratinocytes from a single donor treated with or without UVR were analyzed by RNA-seq, exome-seq, and H3K27ac ChIP-seq at 4 h and 72 h following UVR. Compared to the relatively moderate mutagenic effects of UVR, acute UV exposure induced substantial epigenomic and transcriptomic alterations, illuminating a previously underappreciated role of epigenomic and transcriptomic instability in skin pathogenesis...
February 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28195487/sequential-proton-coupled-electron-transfer-mediates-excited-state-deactivation-of-a-eumelanin-building-block
#18
Juan J Nogueira, Alice Corani, Amal El Nahhas, Alessandro Pezzella, Marco d'Ischia, Leticia González, Villy Sundström
Skin photoprotection is commonly believed to rely on the photochemistry of 5,6-dihydroxyindole (DHI)- and 5,6-dihydroxyindole-2-carboxylic acid (DHICA)-based eumelanin building blocks. Attempts to elucidate the underlying excited-state relaxation mechanisms have been partly unsuccessful due to the marked instability to oxidation. We report a study of the excited-state deactivation of DHI using steady-state and time-resolved fluorescence accompanied by high-level quantum-chemistry calculations including solvent effects...
February 16, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/28153588/positively-charged-phthalocyanine-arginine-conjugates-as-efficient-photosensitizer-for-photodynamic-therapy
#19
Ao Wang, Rongrong Zhou, Lin Zhou, Kang Sun, Jianchun Jiang, Shaohua Wei
Positively charged drugs usually have enhanced water solubility, cellular uptake efficiency and anticancer activity. However, the common quaternized and protonated cationic photosensitizers both have some drawbacks such as needing potentially dangerous agents for preparation and easily being deprotonated in alkaline circumstance. Arginine is unique among the amino acids as its guanidine group has exceptionally high basicity in aqueous solution, which may make it positively charged in a wide range of pH. In this paper, two arginine substituted zinc phthalocyanines (ArgEZnPc and ArgZnPc) were reported...
March 1, 2017: Bioorganic & Medicinal Chemistry
https://www.readbyqxmd.com/read/28152530/the-preventive-effect-of-coffee-compounds-on-dermatitis-and-epidermal-pigmentation-after-ultraviolet-irradiation-in-mice
#20
Yurika Yamate, Keiichi Hiramoto, Eisuke F Sato
BACKGROUND: Ultraviolet (UV) irradiation is well known to promote inflammation and pigmentation of skin. UVB mainly affects dermatitis and pigmentation. Coffee contains a number of polyphenols, such as caffeic acid (CA) and chlorogenic acid (CGA) but their in vivo bioactivity for photobiology remains unclear. METHODS: C57BL/6j male mice were irradiated with UVB (1.0 kJ/m2/day) for 3 days. Five days after the final session of UVB irradiation, the dorsal skin, ear epidermis, and blood samples were analyzed to investigate the inflammatory factors, melanogenesis factors and related hormones...
2017: Skin Pharmacology and Physiology
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