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Betsy Marydasan, Bollapalli Madhuri, Shirisha Cherukommu, Jedy Jose, Mambattakkara Viji, Suneesh C Karunakaran, Tavarekere K Chandrashekar, Kunchala Sridhar Rao, Ch Mohan Rao, Danaboyina Ramaiah
With an objective to develop efficient sensitizers for therapeutical applications, we synthesized a water soluble, 5,10,15,20-tetrakis(3,4-dihydroxyphenyl)chlorin (TDC), and investigated its in vitro and in vivo biological efficacy and compared with the commercially available sensitizers. TDC showed high water solubility (6-fold), when compared to Foscan and exhibited excellent triplet excited state () and singlet oxygen () yields. In vitro photobiological investigations in human ovarian cancer cell lines SKOV-3 showed high photocytotoxicity, negligible dark toxicity, rapid cellular uptake and specific localization of TDC in neoplastic cells as assessed by flow cytometric cell-cycle and propidium iodide staining analysis...
May 16, 2018: Journal of Medicinal Chemistry
Peter Vaupel, Helmut Piazena, Werner Müller, Markus Notter
Thermography-controlled, water-filtered infrared-A (wIRA) is a novel, effective and approved heating technique listed in the ESHO quality assurance guidelines for superficial hyperthermia clinical trials (2017). In order to assess the special features and the potential of wIRA-hyperthermia (wIRA-HT), detailed and updated information about its physical and photobiological background is presented. wIRA allows for (a) application of high irradiances without skin pain and acute grade 2-4 skin toxicities, (b) prolonged, therapeutically relevant exposure times using high irradiances (150-200 mW/cm2 ) and (c) faster and deeper heat extension within tissues...
May 10, 2018: International Journal of Hyperthermia
Eren Canbay, Ayse Kose, Suphi S Oncel
Hydrogen photoproduction from microalgae has been an emerging topic for biofuel development. However, low yield for large-scale cultivations seems to be the main challenge. Immobilization seems to be an alternative method for sustainable hydrogen generation. In this study we examined the bead stability, bead diameter and immobilization method in accordance with photobioreactors (PBR). 2.1 mm diameter beads were selected for PBR experiments. CSTR, tubular and panel type PBRs give important results to develop suitable immobilization matrixes and techniques for mass production in scalable PBR systems...
May 2018: 3 Biotech
Myles Robinson, Palak Shah, Yanhong Cui, Yu-Ying He
N6 -methyladenosine (m6 A) is the most abundant internal RNA modification among numerous post-transcriptional modifications identified in eukaryotic mRNA. m6 A modification of RNA is catalyzed by the "writer" m6 A methyltransferase enzyme complex, consisting of METTL3, METTL14, WTAP, and KIAA1429. The m6 A modification is reversible, and can be removed by "eraser" m6 A demethylase enzymes, namely, FTO and ALKBH5. The biological function of m6 A modification on RNA is carried out by RNA-binding effector proteins called "readers"...
May 4, 2018: Photochemistry and Photobiology
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No abstract text is available yet for this article.
May 3, 2018: Photochemical & Photobiological Sciences
Mario Migliario, Maurizio Sabbatini, Carmen Mortellaro, Filippo Renò
Lasers devices are widely used in various medical fields (e.g. surgery, dermatology, dentistry, rehabilitative medicine, etc) for different applications, ranging from surgical ablation of tissues to biostimulation and pain relief. Laser is an electromagnetic radiation which effects on biological tissues strongly depends on a number of physical parameters. Laser wavelength, energy output, irradiation time and modality, temperature and tissue penetration properties have to be set up according to the clinical target tissue and the desired effect...
May 2, 2018: Journal of Biophotonics
Mark Lucock, Patrice Jones, Charlotte Martin, Zoe Yates, Martin Veysey, John Furst, Emma Beckett
This review explores contemporary ideas about the relationship between light exposure and vitamin biology. Nutritional biochemistry has long recognized the relationship between vitamins A and D and light exposure, but in recent years other vitamins have also been implicated in photoresponsive biological mechanisms that influence health, well-being, and even evolutionary processes. Interactions between light and vitamins can modify genotype-phenotype relationships across the life cycle, providing a basis for interesting new explanations relevant to wide aspects of human biology...
April 28, 2018: Nutrition Reviews
Johannes W Goessling, Yanyan Su, Paulo Cartaxana, Christian Maibohm, Lars F Rickelt, Erik C L Trampe, Sandra L Walby, Daniel Wangpraseurt, Xia Wu, Marianne Ellegaard, Michael Kühl
The optical properties of diatom silicate frustules inspire photonics and nanotechnology research. Whether light interaction with the nano-structure of the frustule also affects diatom photosynthesis has remained unclear due to lack of information on frustule optical properties under more natural conditions. Here we demonstrate that the optical properties of the frustule valves in water affect light harvesting and photosynthesis in live cells of centric diatoms (Coscinodiscus granii). Microscale cellular mapping of photosynthesis around localized spot illumination demonstrated optical coupling of chloroplasts to the valve wall...
April 19, 2018: New Phytologist
Christine Guzman, Xue Han, Eiichi Shoguchi, Sile Nic Chormaic
The partnership between coral and its algal symbionts, Symbiodinium, is crucial to the global environment. Yet, the regulatory process within the photosynthetic machinery of Symbiodinium is still not clearly understood. Here, we studied the influence of light stress from focused red and blue lasers on single Symbiodinium cells. Fluorescence signals were measured to show cell response. Increasing the incident laser power or the exposure time resulted in an increase followed by a decline in fluorescence intensity...
March 29, 2018: Methods and Applications in Fluorescence
Claudia Scalfi-Happ, Zhenxin Zhu, Susanna Graefe, Arno Wiehe, Anastasia Ryabova, Victor Loschenov, Rainer Wittig, Rudolf W Steiner
BACKGROUND: Organic crystalline nanoparticles (NPs) are not fluorescent due to the crystalline structure of the flat molecules organized in layers. In earlier experiments with Aluminum Phthalocyanine (AlPc)-derived NPs, the preferential uptake and dissolution by macrophages was demonstrated [3]. Therefore, inflamed tissue or cancer tissue with accumulated macrophages may exhibit specific fluorescence in contrast to healthy tissue which does not fluoresce. The present study addresses the photobiological effects of NP generated from Temoporfin (mTHPC), a clinically utilized photosensitizer belonging to the chlorin family...
March 19, 2018: Photodiagnosis and Photodynamic Therapy
Valéria Nagy, Anna Podmaniczki, André Vidal-Meireles, Roland Tengölics, László Kovács, Gábor Rákhely, Alberto Scoma, Szilvia Z Tóth
Background: Photobiological H2 production has the potential of becoming a carbon-free renewable energy source, because upon the combustion of H2 , only water is produced. The [Fe-Fe]-type hydrogenases of green algae are highly active, although extremely O2 -sensitive. Sulphur deprivation is a common way to induce H2 production, which, however, relies substantially on organic substrates and imposes a severe stress effect resulting in the degradation of the photosynthetic apparatus. Results: We report on the establishment of an alternative H2 production method by green algae that is based on a short anaerobic induction, keeping the Calvin-Benson-Bassham cycle inactive by substrate limitation and preserving hydrogenase activity by applying a simple catalyst to remove the evolved O2 ...
2018: Biotechnology for Biofuels
Cynthia Al Hageh, Majd Al Assaad, Zeinab El Masri, Nawar Samaan, Mirvat El-Sibai, Christian Khalil, Rony S Khnayzer
Copper is an earth-abundant and a biologically essential metal that offers a promising alternative to noble metals in photochemistry and photobiology. In this work, a series of sterically encumbered Cu(i) bis-phenanthroline complexes were investigated for their use in photochemotherapy (PCT). It was found that Cu(dsbtmp)2+ [dsbtmp = 2,9-disec-butyl-3,4,7,8-tetramethyl-1,10-phenanthroline] (compound 3), which possessed the longest excited state lifetime, exhibited significant in vitro photocytotoxicity on A375 (human malignant melanoma) and A549 (human lung carcinoma) cell lines...
March 20, 2018: Dalton Transactions: An International Journal of Inorganic Chemistry
Pedro Jorge Louro Crugeira, Gustavo M Pires-Santos, Susana C P S de Oliveira, Fernando José Pires Sampaio, Neandder Andrade Correia, Sandra R C de A Fagnani, Fabio Alexandre Chinalia, Paulo Fernando de Almeida, Antônio L B Pinheiro
Cellulose has a highly diversified architecture and its enzymatic complexes are studied for achieving an efficient conversion and a high level of efficiency in the deconstruction of cellulolytic biomass into sugars. The aim of this investigation was to evaluate the effect of Laser or LED light in the cellulolytic activity (CMCase) and on the proliferation of the thermophilic microbial consortium used on the degradation process of a lignocellulosic biomass of green coconut shell. The irradiation protocol consisted of six Laser irradiations (λ660 ηm, 40 mW, 270 s, 13 J/cm2 ) or LED (λ632 ± 2 ηm, 145 mW, 44 s, 13 J/cm2 ) with 12- h time intervals in nutrient deprivation conditions...
April 2018: Journal of Photochemistry and Photobiology. B, Biology
H Nassan, R S Dawe, H Moseley, S H Ibbotson
Background The Scottish Photobiology Service is the national referral pathway for patients with cutaneous photosensitivity diseases in Scotland. We reviewed the pattern of diagnosis of photosensitivity diseases and investigations performed between 1989 and 2015. Methods and Results Data were collected from the Photodiagnostic Database, annual reports and paper records. The total number of patients assessed each year was stable over the period studied (median 242 [range 231-266]), with most being new patients (median 69 [range 62-73]%)...
December 2017: Journal of the Royal College of Physicians of Edinburgh
Julia Hennemann, Roman S Iwasaki, Tamara N Grund, Ralph P Diensthuber, Florian Richter, Andreas Möglich
Sensory photoreceptors evoke numerous adaptive responses in nature and serve as light-gated actuators in optogenetics to enable the spatiotemporally precise, reversible, and noninvasive control of cellular events. The output of optogenetic circuits can often be dialed in by varying illumination quality, quantity, and duration. A programmable matrix of light-emitting diodes has been devised to efficiently probe the response of optogenetic systems to intermittently applied light of varying intensity and pulse frequency...
February 14, 2018: Chembiochem: a European Journal of Chemical Biology
Bruno de Moraes Prianti, Giovanna Figueiredo Novello, Tamires de Souza Moreira Prianti, Davidson Ribeiro Costa, Diego Rodrigues Pessoa, Renata Amadei Nicolau
Various therapies for the treatment of sprains have emerged as advances occur in biomedical engineering and photobiology. Therapy with coherent and non-coherent light is a treatment modality for various musculoskeletal injuries. The main certified phototherapy benefits are the reduction of nociceptive processes and the modulation of the inflammatory process, among others. The objective of this study was to analyse the changes caused by the use of light-emitting diodes (LED) (λ627 ± 10 nm) with an energy density of 10 J/cm2 in 40 subjects divided into two groups (20 placebo and 20 LED)...
February 8, 2018: Lasers in Medical Science
Elena Zvereva, Javier Segarra-Martí, Marco Marazzi, Johanna Brazard, Artur Nenov, Oliver Weingart, Jérémie Léonard, Marco Garavelli, Ivan Rivalta, Elise Dumont, Xavier Assfeld, Stefan Haacke, Antonio Monari
Benzophenone (BP) despite its relatively simple molecular structure is a paradigmatic sensitizer, featuring both photocatalytic and photobiological effects due to its rather complex photophysical properties. In this contribution we report an original theoretical approach to model realistic, ultra-fast spectroscopy data, which requires describing intra- and intermolecular energy and structural relaxation. In particular we explicitly simulate time-resolved pump-probe spectra using a combination of state-of-the art hybrid quantum mechanics/molecular mechanics dynamics to treat relaxation and vibrational effects...
March 14, 2018: Photochemical & Photobiological Sciences
Lei Shu, Wei Xiong, Changyu Shao, Tingting Huang, Pengqiang Duan, Kun Liu, Xurong Xu, Weimin Ma, Ruikang Tang
Photobiological hydrogen production plays a vital role in generating clean renewable energy owing to its low energy consumption and environmental friendliness. Although materials-induced Chlorella aggregates have been developed to achieve sustained photobiological hydrogen production under normal aerobic conditions, the yield is relatively low and equals only 0.42 % of the light-to-H2 energy-conversion efficiency. Herein, we report that only 0.5 vol % dimethyl sulfoxide in an aqueous environment significantly enhances the H2 yield produced by aggregated Chlorella, reaching 0...
April 4, 2018: Chembiochem: a European Journal of Chemical Biology
Isabel Aparici-Espert, Guillermo Garcia-Lainez, Inmaculada Andreu, Miguel Angel Miranda, Virginie Lhiaubet-Vallet
In this work, the attention is focused on UVA-photosensitized reactions triggered by a DNA chromophore-containing lesion, namely 5-formyluracil. This is a major oxidatively generated lesion that exhibits an enhanced light absorption in the UVB-UVA region. The mechanistic study combining photochemical and photobiological techniques shows that irradiation of 5-formyluracil leads to a triplet excited state capable of sensitizing formation of cyclobutane pyrimidine dimers in DNA via a triplet-triplet energy transfer...
March 16, 2018: ACS Chemical Biology
Brian C Thomas
We investigated the potential biological impacts at Earth's surface of stratospheric O3 depletion caused by nearby supernovae known to have occurred about 2.5 and 8 million years ago at about 50 pc distance. New and previously published atmospheric chemistry modeling results were combined with radiative transfer modeling to determine changes in surface-level solar irradiance and biological responses. We find that UVB irradiance is increased by a factor of 1.1 to 2.8, with large variation in latitude, and seasonally at high-latitude regions...
December 28, 2017: Astrobiology
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