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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...
March 8, 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. Here, we devise a programmable matrix of light-emitting diodes 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...
January 31, 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 was relatively low and equalled only 0.42% of the light-to-H2 energy conversion efficiency. Herein, we report that only 0.5 v% dimethyl sulfoxide in an aqueous environment significantly enhanced the H2 yield produced by the aggregated Chlorella, reaching 0...
January 27, 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...
January 4, 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
Xiao Pudroma, Gongsang Duoji, Mantas Grigalavicius, Duan Jie, Asta Juzeniene
Cutaneous melanoma is a deadly skin cancer, resulting from malignant transformation of melanocytes. Long-wave ultraviolet radiation (315-400 nm) is able to damage DNA, cause mutations, and induce melanoma. However, the exact mechanisms of UVA-induced cutaneous melanoma remain a matter of debate. In this review, we give a brief characterization of the most important elements in the photobiology of UVA in melanomagenesis.
2017: Journal of Environmental Pathology, Toxicology and Oncology
Daniel Morgado-Carrasco, Xavier Fustà-Novell, Sebastian Podlipnik, Andrea Combalia, Paula Aguilera
BACKGROUND: Solar urticaria (SU) is a rare photodermatosis. Treatment is challenging, and outcomes are often disappointing. Omalizumab is an anti-IgE, currently approved for treatment of chronic spontaneous urticaria. We sought to evaluate therapy with omalizumab in refractory SU and describe predictive factors for response. MATERIALS/METHODS: Patients with refractory SU under treatment with omalizumab were included in this study. Clinical outcome was evaluated using the Urticaria Activity Score 7 (UAS7), Dermatology Life Quality Index (DLQI) and Pruritus Visual Analogue Scale (VAS)...
November 24, 2017: Photodermatology, Photoimmunology & Photomedicine
Bo-Sen Wu, Mark G Lefsrud
Light emitting diodes have slowly gained market share as horticultural lighting systems in greenhouses due to their rapid improvement in color performances and light outputs. These advancements have increased the availability of the full spectrum of visible wavelengths and the corresponding irradiance outputs available to plants. However, light emitting diodes owners have limited information on the proper options for personal eyewear protection as the irradiance levels have increased. The objective of this study was to measure the light transmittance performance of 12 eyewear protection including welding goggles, safety goggles, polarized glasses and sunglasses across the human visible spectrum (380-740 nm) up to an irradiance level of 1500 W·m(-2) from high-irradiant light emitting diodes assemblies...
November 20, 2017: Journal of Occupational and Environmental Hygiene
Luisa Christensen, Amanda Suggs, Elma Baron
The effects of ultraviolet radiation on human skin have been studied for years, and both its harmful and therapeutic effects are well known. Exposure to UV light can lead to sunburn, immunosuppression, skin aging, and carcinogenesis, and photoprotection is strongly advocated. However, when used under controlled conditions, UV radiation can also be helpful in the diagnosis and treatment of many skin conditions.
2017: Advances in Experimental Medicine and Biology
Anzhela Galstyan, Johannes Putze, Ulrich Dobrindt
Development of antimicrobial photodynamic therapy (aPDT) is highly dependent on the development of suitable photosensitizers (PS): ideally affinity of PS towards bacterial cells should be much higher than towards mammalian cells. Cationic charge of PS may lead to selective binding of PS to bacteria mediated by electrostatic interaction; however, the photodynamic outcome is highly dependent on the lipophilicity of PS. Herein we report the aPDT effect of silicon(IV)phthalocyanine derivatives bearing four positive charges and methyl, phenyl or naphthyl substituents on the periphery of the macrocycle...
November 8, 2017: Chemistry: a European Journal
Brian L Diffey, Peter M Farr
The earliest contribution made by Jan van der Leun to the field of photobiology was studying the mechanism of UV-induced erythema in human skin - a subject he chose for his PhD in the 1960s. His contribution to this topic encouraged us to continue this work and over a number of years in the 1980s and 1990s, we carried out several studies on quantitative aspects of UV erythema. A major part of Jan's thesis focused on diffusion processes in UV erythema and his observations led him to conclude that erythema induced by radiation with wavelengths of around 300 nm was due to the actions of a diffusing mediator arising in the epidermis, whereas radiation at shorter wavelengths around 254 nm, caused erythema by exerting a direct effect on the dermal blood vessels...
October 26, 2017: Photochemical & Photobiological Sciences
Masamitsu Wada
Plant cells connected to adjacent cells with rigid cell wall cannot change their position, so that appropriate nuclear positioning according to nuclear movement is indispensable for cellular development involving unequal cell division. Sessile plants are severely affected by fluctuating environmental conditions, so that movement of organelles including nucleus is fundamental to accomplish physiological functions. The mechanisms of nuclear movement and their purposes studied recently with Arabidopsis thaliana, the model plants for genetics and molecular biology, and the nuclear behavior in fern gametophytes, an apical growing protonemal cell and a two-dimensional prothallus of Adiantum capillus-veneris, the model plants for cell biology and photobiology are described in this review...
October 17, 2017: Seminars in Cell & Developmental Biology
Dimitri D Deheyn
No abstract text is available yet for this article.
October 26, 2017: Nature
Ana Luiza Ribeiro de Souza, Ethan LaRochelle, Kayla Marra, Jason Gunn, Scott C Davis, Kimberley S Samkoe, M Shane Chapman, Edward V Maytin, Tayyaba Hasan, Brian W Pogue
BACKGROUND: Sunlight can activate photodynamic therapy (PDT), and this is a proven strategy to reduce pain caused byconventional PDT treatment, but assessment of this and other alternative low dose rate light sources, and their efficacy, has not been studied in an objective, controlled pre-clinical setting. This study used three objective assays to assess the efficacy of different PDT treatment regimens, using PpIX fluorescence as a photophysical measure, STAT3 cross-linking as a photochemical measure, and keratinocyte damage as a photobiological measure...
December 2017: Photodiagnosis and Photodynamic Therapy
Lars Kohler, Leona Nease, Pascal Vo, Jenna Garofolo, David K Heidary, Randolph P Thummel, Edith C Glazer
Light-activated compounds are powerful tools and potential agents for medical applications, as biological effects can be controlled in space and time. Ruthenium polypyridyl complexes can induce cytotoxic effects through multiple mechanisms, including acting as photosensitizers for singlet oxygen ((1)O2) production, generating other reactive oxygen species (ROS), releasing biologically active ligands, and creating reactive intermediates that form covalent bonds to biological molecules. A structure-activity relationship (SAR) study was performed on a series of Ru(II) complexes containing isomeric tetramethyl-substituted bipyridyl-type ligands...
September 26, 2017: Inorganic Chemistry
Suleyman I Allakhverdiev, Sergey K Zharmukhamedov, Margarita V Rodionova, Vladimir A Shuvalov, Charles Dismukes, Jian-Ren Shen, James Barber, Göran Samuelsson, Govindjee
Vyacheslav Vasilevich (V.V.) Klimov (or Slava, as most of us called him) was born on January 12, 1945 and passed away on May 9, 2017. He began his scientific career at the Bach Institute of Biochemistry of the USSR Academy of Sciences (Akademy Nauk (AN) SSSR), Moscow, Russia, and then, he was associated with the Institute of Photosynthesis, Pushchino, Moscow Region, for about 50 years. He worked in the field of biochemistry and biophysics of photosynthesis. He is known for his studies on the molecular organization of photosystem II (PSII)...
September 18, 2017: Photosynthesis Research
Mayumi Hatakeyama, Atsushi Fukunaga, Ken Washio, Kumiko Taguchi, Yoshiko Oda, Kanako Ogura, Chikako Nishigori
UV radiation, particularly UVB, is the major risk factor for the induction of skin cancer, and it induces skin inflammation and immunosuppression. Although reports documented that Langerhans cells (LCs) play various roles in photobiology, little is known about whether they contribute to UVB-induced cutaneous inflammation. Recently, the anti-inflammatory effect of apoptotic cells was noted. This study focuses on the roles of LCs and apoptotic cells in UVB-induced cutaneous inflammation. We show that LCs are essential for resolution of UVB-induced cutaneous inflammation...
October 15, 2017: Journal of Immunology: Official Journal of the American Association of Immunologists
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