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https://www.readbyqxmd.com/read/30196211/mercury-mobility-and-effects-in-the-salt-marsh-plant-halimione-portulacoides-uptake-transport-and-toxicity-and-tolerance-mechanisms
#1
Maria Teresa Cabrita, Bernardo Duarte, Rute Cesário, Ricardo Mendes, Holger Hintelmann, Kevin Eckey, Brian Dimock, Isabel Caçador, João Canário
The plant Halimione portulacoides, an abundant species widely distributed in temperate salt-marshes, has been previously assessed as bioindicator and biomonitor of mercury contamination in these ecosystems. The present study aims to assess uptake and distribution of total mercury (THg) and methylmercury (MMHg) within H. portulacoides, potential mercury release by volatilization through leaves, and toxicity and tolerance mechanisms by investigating plant photochemical responses. Stem cuttings of H. portulacoides were collected from a salt-marsh within the Tagus estuary natural protected area, and grown under hydroponic conditions...
August 28, 2018: Science of the Total Environment
https://www.readbyqxmd.com/read/30109759/rapamycin-for-refractory-discoid-lupus-erythematosus
#2
Mitchell Herold, Nicholas A Richmond, Michael A Montuno, Stanton K Wesson, Kiran Motaparthi
Generalized discoid lupus erythematosus can pose a therapeutic challenge for dermatologists. Current treatment emphasizes photoprotection, topical and systemic steroids, and steroid-sparing immunosuppressive agents if necessary. Rapamycin, also known as sirolimus, selectively inhibits mammalian target of rapamycin, a regulatory kinase responsible for multiple signal transduction pathways. Mammalian target of rapamycin inhibition reduces cell division, lymphocyte proliferation, cytokine release, and downstream pathways unique from other classes of immunomodulatory drugs...
August 14, 2018: Dermatologic Therapy
https://www.readbyqxmd.com/read/30102774/effects-and-mechanism-of-nicotinamide-against-uva-and-or-uvb-mediated-dna-damages-in-normal-melanocytes
#3
Gagan Chhabra, Debra R Garvey, Chandra K Singh, Charlotte A Mintie, Nihal Ahmad
Melanoma incidences are increasing rapidly, and ultraviolet (UV) radiation from the sun is believed to be its major contributing factor. UV exposure causes DNA damage in skin which may initiate cutaneous skin cancers including melanoma. Melanoma arises from melanocytes, the melanin-producing skin cells, following genetic dysregulations resulting into hyperproliferative phenotype and neoplastic transformation. Both UVA and UVB exposure to the skin are believed to trigger melanocytic hyperplasia and melanomagenesis...
August 13, 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/30086234/polarizable-embedding-combined-with-the-algebraic-diagrammatic-construction-tackling-excited-states-in-biomolecular-systems
#4
Maximilian Scheurer, Michael F Herbst, Peter Reinholdt, Jógvan Magnus Haugaard Olsen, Andreas Dreuw, Jacob Kongsted
We present a variant of the algebraic diagrammatic construction (ADC) scheme by combining ADC with the polarizable embedding (PE) model. The presented PE-ADC method is implemented through second and third order and is designed with the aim of performing accurate calculations of excited states in large molecular systems. Accuracy and large-scale applicability are demonstrated with three case studies, and we further analyze the importance of both state-specific and linear-response-type corrections to the excitation energies in the presence of the polarizable environment...
September 11, 2018: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/30056500/effects-of-cadmium-stress-on-the-antioxidant-system-and-chlorophyll-fluorescence-characteristics-of-two-taxodium-clones
#5
Ying-Li Ma, Hui-Fang Wang, Ping Wang, Chao-Guang Yu, Si-Qian Luo, Yu-Feng Zhang, Yin-Feng Xie
The T.118 and T.406 seedlings showed strong adaptability under Cd concentrations ≤ 50 µM. The mechanisms of photoprotection in T.118 and T.406 differed in high-Cd concentrations. To explore the physiological response characteristics of Taxodium hybrids to cadmium (Cd) stress and provide basis for screening of Cd-tolerant species, the hydroponic cultivation of T.118 and T.406 seedlings was conducted to demonstrate the effects of Cd stress on seedling growth, antioxidant system, and chlorophyll fluorescence parameters...
July 28, 2018: Plant Cell Reports
https://www.readbyqxmd.com/read/30032070/the-roles-of-arabidopsis-proteins-of-lhcb4-lhcb5-and-lhcb6-in-oxidative-stress-under-natural-light-conditions
#6
Yang-Er Chen, Jie Ma, Nan Wu, Yan-Qiu Su, Zhong-Wei Zhang, Ming Yuan, Huai-Yu Zhang, Xian-Yin Zeng, Shu Yuan
Under light conditions, highly reactive oxygen species (ROS) can be generated in the antenna systems and the reaction center of photosystems (PS). The protective roles of Lhcb4 (CP29), Lhcb5 (CP26) and Lhcb6 (CP24), three minor chlorophyll binding antenna proteins during photoinhibition have been well studied. However, their regulatory mechanisms against oxidative damages under natural light conditions remain unknown. Here we investigated their specific roles in oxidative stress responses and photosynthetic adaptation by using the Arabidopsis thaliana knockout lines grown in the field condition...
September 2018: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/30008155/rapid-regulation-of-excitation-energy-in-two-pennate-diatoms-from-contrasting-light-climates
#7
Allen K Derks, Doug Bruce
Non-photochemical quenching (NPQ) is a fast acting photoprotective response to high light stress triggered by over excitation of photosystem II. The mechanism for NPQ in the globally important diatom algae has been principally attributed to a xanthophyll cycle, analogous to the well-described qE quenching of higher plants. This study compared the short-term NPQ responses in two pennate, benthic diatom species cultured under identical conditions but which originate from unique light climates. Variable chlorophyll fluorescence was used to monitor photochemical and non-photochemical excitation energy dissipation during high light transitions; whereas whole cell steady state 77 K absorption and emission were used to measure high light elicited changes in the excited state landscapes of the thylakoid...
July 14, 2018: Photosynthesis Research
https://www.readbyqxmd.com/read/29998107/oral-photoprotection-effective-agents-and-potential-candidates
#8
REVIEW
Concepción Parrado, Neena Philips, Yolanda Gilaberte, Angeles Juarranz, Salvador González
Electromagnetic radiation in the ultraviolet, visible, and infrared ranges produces biologic effects in humans. Where some of these effects are beneficial, others are harmful to the skin, particularly those stemming from ultraviolet radiation (UVR). Pharmacological photoprotection can be topical or systemic. Systemic photoprotection is often administered orally, complementing topical protection. New and classic oral agents (e.g., essential micronutrients as vitamins, minerals, polyphenols, carotenoids) are endowed with photoprotective and anti-photocarcinogenic properties...
2018: Frontiers in Medicine
https://www.readbyqxmd.com/read/29946165/specialized-proteomic-responses-and-an-ancient-photoprotection-mechanism-sustain-marine-green-algal-growth-during-phosphate-limitation
#9
Jian Guo, Susanne Wilken, Valeria Jimenez, Chang Jae Choi, Charles Ansong, Richard Dannebaum, Lisa Sudek, David S Milner, Charles Bachy, Emily Nahas Reistetter, Virginia A Elrod, Denis Klimov, Samuel O Purvine, Chia-Lin Wei, Govindarajan Kunde-Ramamoorthy, Thomas A Richards, Ursula Goodenough, Richard D Smith, Stephen J Callister, Alexandra Z Worden
Marine algae perform approximately half of global carbon fixation, but their growth is often limited by the availability of phosphate or other nutrients1,2 . As oceans warm, the area of phosphate-limited surface waters is predicted to increase, resulting in ocean desertification3,4 . Understanding the responses of key eukaryotic phytoplankton to nutrient limitation is therefore critical5,6 . We used advanced photo-bioreactors to investigate how the widespread marine green alga Micromonas commoda grows under transitions from replete nutrients to chronic phosphate limitation and subsequent relief, analysing photosystem changes and broad cellular responses using proteomics, transcriptomics and biophysical measurements...
July 2018: Nature Microbiology
https://www.readbyqxmd.com/read/29782823/changing-the-site-energy-of-per-614-in-the-peridinin-chlorophyll-a-protein-does-not-alter-its-capability-of-chlorophyll-triplet-quenching
#10
Alessandro Agostini, Jens Niklas, Tim Schulte, Marilena Di Valentin, Marco Bortolus, Eckhard Hofmann, Wolfgang Lubitz, Donatella Carbonera
The peridinin-chlorophyll-a protein (PCP) is a water-soluble light harvesting protein of the dinoflagellate Amphidinium carterae, employing peridinin (Per) as the main carotenoid to fulfil light harvesting and photo-protective functions. Per molecules bound to the protein experience specific molecular surroundings which lead to different electronic and spectral properties. In the refolded N89 L variant PCP (N89 L-RFPCP) a significant part of the intensity on the long wavelength side of the absorption spectrum is shifted to shorter wavelengths due to a significant change in the Per-614 site energy...
August 2018: Biochimica et biophysica acta. Bioenergetics
https://www.readbyqxmd.com/read/29768722/genoprotective-effect-of-phyllanthus-orbicularis-extract-against-uva-uvb-and-solar-radiation
#11
Marioly Vernhes Tamayo, André Passaglia Schuch, Teiti Yagura, Luis Baly Gil, Carlos Frederico Martins Menck, Angel Sánchez-Lamar
One approach to protect the human skin against harmful effects of solar ultraviolet (UV) radiation was to use natural products as photoprotectors. In this work, the extract from specie Phyllanthus orbicularis K was evaluated as a protective agent against the photodamage by UVB, UVA artificial lamps, and environmental sunlight exposure. The plasmid DNA solutions were exposed to radiations using the DNA dosimeter system in the presence of plant extract. The DNA repair enzymes, Escherichia coli Formamidopyrimidine-DNA glycosylase (Fpg) and T4 bacteriophage endonuclease V (T4-endo V), were employed to discriminate oxidized DNA damage and cyclobutane pyrimidine dimers (CPD), respectively...
September 2018: Photochemistry and Photobiology
https://www.readbyqxmd.com/read/29697102/differential-reorganisation-of-cutaneous-elastic-fibres-a-comparison-of-the-in-vivo-effects-of-broadband-ultraviolet-b-versus-solar-simulated-radiation
#12
Nisamanee Charoenchon, Lesley E Rhodes, Suzanne M Pilkington, Mark D Farrar, Rachel E B Watson
Long-term exposure of human skin to ultraviolet radiation (UVR) in sunlight negatively impacts its appearance and function with photoaged skin having a characteristic leathery, rough appearance, with deep wrinkles. These clinical features of photodamage are thought to result from UVR-induced remodelling of the dermal extracellular matrix, particularly the elastic fibre system. There are few in vivo human data on the impact of acute UVR exposure on this fibre system and particularly solar-simulated radiation (SSR)-mediated effects...
July 11, 2018: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/29679619/a-global-perspective-on-carotenoids-metabolism-biotechnology-and-benefits-for-nutrition-and-health
#13
REVIEW
Manuel Rodriguez-Concepcion, Javier Avalos, M Luisa Bonet, Albert Boronat, Lourdes Gomez-Gomez, Damaso Hornero-Mendez, M Carmen Limon, Antonio J Meléndez-Martínez, Begoña Olmedilla-Alonso, Andreu Palou, Joan Ribot, Maria J Rodrigo, Lorenzo Zacarias, Changfu Zhu
Carotenoids are lipophilic isoprenoid compounds synthesized by all photosynthetic organisms and some non-photosynthetic prokaryotes and fungi. With some notable exceptions, animals (including humans) do not produce carotenoids de novo but take them in their diets. In photosynthetic systems carotenoids are essential for photoprotection against excess light and contribute to light harvesting, but perhaps they are best known for their properties as natural pigments in the yellow to red range. Carotenoids can be associated to fatty acids, sugars, proteins, or other compounds that can change their physical and chemical properties and influence their biological roles...
April 2018: Progress in Lipid Research
https://www.readbyqxmd.com/read/29672054/correlated-molecular-structural-motions-for-photoprotection-after-deep-uv-irradiation
#14
Longteng Tang, Yanli Wang, Liangdong Zhu, Che Lee, Chong Fang
Exposure to ultraviolet (UV) light could cause photodamage to biomolecular systems and degrade optoelectronic devices. To mitigate such detrimental effects from the bottom up, we strategically select a photosensitive molecule pyranine and implement femtosecond electronic and Raman spectroscopies to elucidate its ultrafast photoprotection mechanisms in solution. Our results show that pyranine undergoes excited-state proton transfer in water, while this process is blocked in methanol regardless of excitation wavelengths (267, 400 nm)...
May 3, 2018: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29665756/photoprotection-awareness-and-practices-among-patients-with-systemic-lupus-erythematosus-and-its-association-with-disease-activity-and-severity
#15
W D Abdul Kadir, A Jamil, S Sazliyana Shaharir, N Md Nor, A H Abdul Gafor
Objective The objective of this paper is to determine photoprotection awareness, knowledge, practices, and its relationship with disease activity and damage in patients with systemic lupus erythematosus (SLE). Methods A cross-sectional study was performed. Data were acquired from in-person interviews and medical records. Results A total of 199 (89.6%) females and 23 (10.4%) males were recruited. Median age was 39.00 (interquartile range (IQR) 18) years, disease duration 12.12 (IQR 8) years, Fitzpatrick skin phototype III 119 (53...
July 2018: Lupus
https://www.readbyqxmd.com/read/29625778/-the-epidermal-barrier
#16
R Abdayem, M Haftek
The skin acts as an interface between the body and its surrounding environment. The epidermis, the surface layer of the skin, is chiefly responsible for this interactive protective function. The epidermal barrier may be subdivided into three defensive systems: the photoprotective barrier, the immune barrier, and the physical and chemical barrier of the stratum corneum or horny layer. To protect against harmful ultraviolet radiation, the epidermis has absorption factors such as melanin, produced by melanocytes, and urocanic acid, which is a degradation product of filaggrin...
April 2018: Annales de Dermatologie et de Vénéréologie
https://www.readbyqxmd.com/read/29565294/in-vitro-assessment-of-total-phenolic-and-flavonoid-contents-antioxidant-and-photoprotective-activities-of-crude-methanolic-extract-of-aerial-parts-of-capnophyllum-peregrinum-l-lange-apiaceae-growing-in-algeria
#17
Mostefa Lefahal, Nabila Zaabat, Radia Ayad, El Hani Makhloufi, Lakhdar Djarri, Merzoug Benahmed, Hocine Laouer, Gema Nieto, Salah Akkal
Background: Capnophyllum peregrinum (L.) Lange (Apiaceae) is the unique taxon of capnophyllum genus in Algerian flora. It has never been investigated in regards to its total phenolic and flavonoid contents and antioxidant and photoprotective activities. Methods: C. peregrinum aerial parts extracted with absolute methanol. The total flavonoid and phenolic contents of the extract were evaluated to determine their correlation with the antioxidant and photoprotective activities of the extract. Results: The methanolic extract demonstrated a significant amount of phenolics and flavonoids (74...
March 22, 2018: Medicines (Basel, Switzerland)
https://www.readbyqxmd.com/read/29564230/vitamin-b12-determination-in-milk-whey-and-different-by-products-of-ricotta-cheese-production-by-ultra-performance-liquid-chromatography-coupled-with-tandem-mass-spectrometry
#18
Adele Repossi, Elisa Zironi, Teresa Gazzotti, Andrea Serraino, Giampiero Pagliuca
Vitamin B12 (cobalamin) is a metal complex composed of a central cobalt ion bonded to six ligands. It is essential for major biological functions such as protein, fat and carbohydrate metabolism, the maintenance of the central nervous system, and the formation of red blood cells. Since mammals cannot synthesize cobalamin, dietary intake represents the only natural source for humans. Dairy products can provide significant levels of cobalamin; moreover, the European Food Safety Authority (EFSA) panel has set the recommended intake at 4 μg/day for adults...
October 20, 2017: Italian Journal of Food Safety
https://www.readbyqxmd.com/read/29547525/sunscreen-based-photocages-for-topical-drugs-a-photophysical-and-photochemical-study-of-a-diclofenac-avobenzone-dyad
#19
Isabel Aparici-Espert, Miguel A Miranda, Virginie Lhiaubet-Vallet
Photosensitization by drugs is a problem of increasing importance in modern life. This phenomenon occurs when a chemical substance in the skin is exposed to sunlight. Photosensitizing drugs are reported to cause severe skin dermatitis, and indeed, it is generally advised to avoid sunbathing and to apply sunscreen. In this context, the nonsteroidal anti-inflammatory drug (NSAID) diclofenac is a photosensitive drug, especially when administered in topical form. In this work, efforts have been made to design and study an innovative pro-drug/pro-filter system containing diclofenac and the UVA filter avobenzone in order to develop a safer use of this topical drug...
March 16, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29524381/functional-interaction-of-low-homology-frps-from-different-cyanobacteria-with-synechocystis-ocp
#20
Yury B Slonimskiy, Eugene G Maksimov, Evgeny P Lukashev, Marcus Moldenhauer, Cy M Jeffries, Dmitri I Svergun, Thomas Friedrich, Nikolai N Sluchanko
Photosynthesis requires a balance between efficient light harvesting and protection against photodamage. The cyanobacterial photoprotection system uniquely relies on the functioning of the photoactive orange carotenoid protein (OCP) that under intense illumination provides fluorescence quenching of the light-harvesting antenna complexes, phycobilisomes. The recently identified fluorescence recovery protein (FRP) binds to the photoactivated OCP and accelerates its relaxation into the basal form, completing the regulatory circle...
May 2018: Biochimica et biophysica acta. Bioenergetics
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