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https://www.readbyqxmd.com/read/28386667/dynamic-modeling-of-temperature-change-in-outdoor-operated-tubular-photobioreactors
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
#7
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
#8
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
#9
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
#10
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
#11
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
#12
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
#13
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
#14
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
#15
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
#16
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
https://www.readbyqxmd.com/read/28071592/development-and-evaluation-of-zinc-phthalocyanine-nanoemulsions-for-use-in-photodynamic-therapy-for-leishmania-spp
#17
Luciana Betzler de Oliveira de Siqueira, Verônica da Silva Cardoso, Igor Almeida Rodrigues, Ana Lúcia Vazquez-Villa, Elisabete Pereira Dos Santos, Bruno da Costa Leal Ribeiro Guimarães, Cristal Dos Santos Cerqueira Coutinho, Alane Beatriz Vermelho, Eduardo Ricci Junior
Photodynamic therapy (PDT) combines light with photosensitizers (PS) for production of reactive oxygen species (ROS) that can kill infectious microorganisms such as bacteria, fungi and protozoa. The application of nanotechnology has enabled the advancement of PDT because many PS are insoluble in water, necessitating a nanocarrier as a physiologically acceptable carrier. Nanoemulsions are efficient nanocarriers for solubilizing liposoluble drugs, like the PS, in water. Cutaneous (CL) and mucocutaneous leishmaniasis (ML) are caused by different species of the genus Leishmania, transmitted to humans by sandfly bites...
February 10, 2017: Nanotechnology
https://www.readbyqxmd.com/read/28064366/increased-heterocyst-frequency-by-patn-disruption-in-anabaena-leads-to-enhanced-photobiological-hydrogen-production-at-high-light-intensity-and-high-cell-density
#18
Hajime Masukawa, Hidehiro Sakurai, Robert P Hausinger, Kazuhito Inoue
The effects of increasing the heterocyst-to-vegetative cell ratio on the nitrogenase-based photobiological hydrogen production by the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were studied. Using the uptake hydrogenase-disrupted mutant (ΔHup) as the parent, a deletion-insertion mutant (PN1) was created in patN, known to be involved in heterocyst pattern formation and leading to multiple singular heterocysts (MSH) in Nostoc punctiforme strain ATCC 29133. The PN1 strain showed heterocyst differentiation but failed to grow in medium free of combined-nitrogen; however, a spontaneous mutant (PN22) was obtained on prolonged incubation of PN1 liquid cultures and was able to grow robustly on N2...
March 2017: Applied Microbiology and Biotechnology
https://www.readbyqxmd.com/read/28042171/an-overview-of-photosubstitution-reactions-of-ru-ii-imine-complexes-and-their-application-in-photobiology-and-photodynamic-therapy
#19
Jessica K White, Russell H Schmehl, Claudia Turro
This article is a short review that presents a short review of photosubstitution reactions of Ru(II) imine complexes and illustrates their use in the development of therapeutic agents. The review begins with an overview of the photophysical behavior and common photoreactions of Ru(II) imine complexes, with select examples from the literature since the 1960s. It is followed by a more detailed picture of the application of knowledge gained over the years in the development of Ru(II) complexes for photobiology and photodynamic therapy...
January 1, 2017: Inorganica Chimica Acta
https://www.readbyqxmd.com/read/28038885/ultraviolet-radiation-and-the-skin-photobiology-and-sunscreen-photoprotection
#20
Antony R Young, Joël Claveau, Ana Beatris Rossi
The efficacy of sunscreens can be measured by different methods, involving in vitro, ex vivo, or in vivo techniques. There is a need for a worldwide standardization of these methods to avoid misunderstanding and confusion among sunscreen users. The clinical benefits of sunscreens have been demonstrated in randomized controlled trials that established the role of sunscreens in the prevention of actinic keratoses, squamous cell carcinomas, nevi, and melanomas. Sunscreens also prevent photoimmunosuppression and signs of photoaging...
March 2017: Journal of the American Academy of Dermatology
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