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https://www.readbyqxmd.com/read/27915172/dark-chilling-induces-substantial-structural-changes-and-modifies-galactolipid-and-carotenoid-composition-during-chloroplast-biogenesis-in-cucumber-cucumis-sativus-l-cotyledons
#1
Joanna Skupień, Joanna Wójtowicz, Łucja Kowalewska, Radosław Mazur, Maciej Garstka, Katarzyna Gieczewska, Agnieszka Mostowska
Plants in a temperate climate are often subject to different environmental factors, chilling stress among them, which influence the growth especially during early stages of plant development. Chloroplasts are one of the first organelles affected by the chilling stress. Therefore the proper biogenesis of chloroplasts in early stages of plant growth is crucial for undertaking the photosynthetic activity. In this paper, the analysis of the cotyledon chloroplast biogenesis at different levels of plastid organization was performed in cucumber, one of the most popular chilling sensitive crops...
November 28, 2016: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/27915030/the-effect-of-anionic-dicephalic-surfactants-on-fabrication-of-varied-core-nanocarriers-for-sustained-release-of-porphyrin-photosensitizers
#2
Urszula Bazylińska, Renata Frąckowiak, Zbigniew Brzózka, Kazimiera A Wilk
Double-headed anionic surfactants could provide a profound group of efficient stabilizers of new template-mediated nanocarriers for effective encapsulation and sustained release of highly hydrophobic photosensitizers, and therefore their improved therapeutic activity in photodynamic therapy (PDT) protocols. We have thus encapsulated porphyrin-origin dyes, i.e., verteporfin (VP) and meso-tetraphenylporphyrin (TPP) in different types of sodium alkyliminobisacetates, Cn(COONa)2-stabilized nanosystems including biocompatible poly(l-glutamic acid)/poly(l-lysine) - PGA/PLL, multilayer nanocapsules (NCs)...
November 19, 2016: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/27915023/anisotropic-noble-metal-nanoparticles-synthesis-surface-functionalization-and-applications-in-biosensing-bioimaging-drug-delivery-and-theranostics
#3
REVIEW
Gokul Paramasivam, Namitharan Kayambu, Arul Maximus Rabel, Ashok K Sundramoorthy, Anandhakumar Sundaramurthy
Anisotropic nanoparticles have fascinated scientists and engineering communities for over a century because of their unique physical and chemical properties. In recent years, continuous advances in design and fabrication of anisotropic nanoparticles have opened new avenues for application in various areas of biology, chemistry and physics. Anisotropic nanoparticles have the plasmon absorption in the visible as well as near-infrared (NIR) region, which enable them to be used for crucial applications such as biological imaging, medical diagnostics and therapy ("theranostics")...
November 30, 2016: Acta Biomaterialia
https://www.readbyqxmd.com/read/27914582/photochemistry-of-nanoporous-carbons-perspectives-in-energy-conversion-and-environmental-remediation
#4
REVIEW
Alicia Gomis-Berenguer, Leticia F Velasco, Inmaculada Velo-Gala, Conchi O Ania
The interest in the use of nanoporous carbon materials in applications related to energy conversion and storage, either as catalysts or additives, has grown over recent decades in various disciplines. Since the early studies reporting the benefits of the use of nanoporous carbons as inert supports of semiconductors and as electron acceptors that enhance the splitting of the photogenerated excitons, many researchers have investigated the key role of carbon matrices coupled to all types of photoactive materials...
November 16, 2016: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/27914257/photosensitized-degradation-of-acetaminophen-in-natural-organic-matter-solutions-the-role-of-triplet-states-and-oxygen
#5
Yanyun Li, Yanheng Pan, Lushi Lian, Shuwen Yan, Weihua Song, Xin Yang
The photolysis of acetaminophen, a widely used pharmaceutical, in simulated natural organic matter solutions was investigated. The triplet states of natural organic matter ((3)NOM*) were found to play the dominant role in its photodegradation, while the contributions from hydroxyl radicals and singlet oxygen were negligible. Dissolved oxygen (DO) plays a dual role. From anaerobic to microaerobic (0.5 mg/L DO) conditions, the degradation rate of acetaminophen increased by 4-fold. That suggests the involvement of DO in reactions with the degradation intermediates...
November 22, 2016: Water Research
https://www.readbyqxmd.com/read/27910074/evolutional-characterization-of-photochemically-induced-stroke-in-rats-a-multimodality-imaging-and-molecular-biological-study
#6
Nai-Wei Liu, Chien-Chih Ke, Yonghua Zhao, Yi-An Chen, Kim-Chuan Chan, David Tat-Wei Tan, Jhih-Shian Lee, You-Yin Chen, Tun-Wei Hsu, Ya-Ju Hsieh, Chi-Wei Chang, Bang-Hung Yang, Wen-Sheng Huang, Ren-Shyan Liu
Photochemically induced cerebral ischemia is an easy-manipulated, reproducible, relatively noninvasive, and lesion controllable model for translational study of ischemic stroke. In order to longitudinally investigate the characterization of the model, magnetic resonance imaging, (18)F-2-deoxy-glucose positron emission tomography, fluorescence, and bioluminescence imaging system were performed in correlation with triphenyl tetrazolium chloride (TTC), hematoxylin-eosin staining, and immunohistochemistry examinations of glial fibrillary acidic protein, CD68, NeuN, von willebrand factor, and α-smooth muscle actin in the infarct zone...
December 1, 2016: Translational Stroke Research
https://www.readbyqxmd.com/read/27909300/cyanobacterial-photoprotection-by-the-orange-carotenoid-protein
#7
REVIEW
Diana Kirilovsky, Cheryl A Kerfeld
In photosynthetic organisms, the production of dangerous oxygen species is stimulated under high irradiance. To cope with this stress, these organisms have evolved photoprotective mechanisms. One type of mechanism functions to decrease the energy arriving at the photochemical centres by increasing thermal dissipation at the level of antennae. In cyanobacteria, the trigger for this mechanism is the photoactivation of a soluble carotenoid protein, the orange carotenoid protein (OCP), which is a structurally and functionally modular protein...
December 2, 2016: Nature Plants
https://www.readbyqxmd.com/read/27908242/participation-of-two-carbonic-anhydrases-of-the-alpha-family-in-photosynthetic-reactions-in-arabidopsis-thaliana
#8
E M Zhurikova, L K Ignatova, N N Rudenko, V A Mudrik, D V Vetoshkina, B N Ivanov
The expression of genes of two carbonic anhydrases (CA) belonging to the α-family, α-CA2 and α-CA4 (according to the nomenclature in N. Fabre et al. (2007) Plant Cell Environ., 30, 617-629), was studied in arabidopsis (Arabidopsis thaliana, var. Columbia) leaves. The expression of the At2g28210 gene coding α-CA2 decreased under increase in plant illumination, while the expression of the At4g20990 gene coding α-CA4 increased. Under conditions close to optimal for photosynthesis, in plants with gene At2g28210 knockout, the effective quantum yield of photosystem 2 and the light-induced accumulation of hydrogen peroxide in leaves were lower than in wild type plants, while the coefficient of non-photochemical quenching of leaf chlorophyll a fluorescence and the rate of CO2 assimilation in leaves were higher...
October 2016: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/27904946/chlorophyll-fluorescence-lifetime-imaging-provides-new-insight-into-the-chlorosis-induced-by-plant-virus-infection
#9
Rong Lei, Hongshan Jiang, Fan Hu, Jin Yan, Shuifang Zhu
Leaf chlorosis induced by plant virus infection has a short fluorescence lifetime, which reflects damaged photosynthetic complexes and degraded chloroplasts. Plant viruses often induce chlorosis and necrosis, which are intimately related to photosynthetic functions. Chlorophyll fluorescence lifetime measurement is a valuable noninvasive tool for analyzing photosynthetic processes and is a sensitive indicator of the environment surrounding the fluorescent molecules. In this study, our central goal was to explore the effect of viral infection on photosynthesis by employing chlorophyll fluorescence lifetime imaging (FLIM), steady-state fluorescence, non-photochemical quenching (NPQ), transmission electron microscopy (TEM), and pigment analysis...
November 30, 2016: Plant Cell Reports
https://www.readbyqxmd.com/read/27903435/lack-of-effect-of-selected-sunscreens-applied-on-ex-vivo-human-skin-for-5-methyl-aminolevulinic-acid-penetration-and-protoporphyrin-ix-photoactivation
#10
Hanan Osman-Ponchet, Karine Sevin, Alexandre Gaborit, Magali Kouidhi, Johanna Hanaizi, Pierre Comby, Bernard Ruty, Guy Bouvier
BACKGROUND: Photodynamic therapy (PDT) is a successful treatment for non-melanoma skin cancers. Methyl-aminolevulinate (MAL) is metabolized to protoporphyrin IX (PpIX) which accumulates in the skin lesion and which generates a painful photochemical toxic reaction upon red light exposure. PDT using daylight (DL) exposure is now used to reduce pain and subjects are advised to protect the areas with sunscreen. This work investigated the effect of sunscreen on MAL penetration and PpIX photoactivation in ex vivo human skin...
November 26, 2016: Photodiagnosis and Photodynamic Therapy
https://www.readbyqxmd.com/read/27901024/coding-and-decoding-libraries-of-sequence-defined-functional-copolymers-synthesized-via-photoligation
#11
Nicolas Zydziak, Waldemar Konrad, Florian Feist, Sergii Afonin, Steffen Weidner, Christopher Barner-Kowollik
Designing artificial macromolecules with absolute sequence order represents a considerable challenge. Here we report an advanced light-induced avenue to monodisperse sequence-defined functional linear macromolecules up to decamers via a unique photochemical approach. The versatility of the synthetic strategy-combining sequential and modular concepts-enables the synthesis of perfect macromolecules varying in chemical constitution and topology. Specific functions are placed at arbitrary positions along the chain via the successive addition of monomer units and blocks, leading to a library of functional homopolymers, alternating copolymers and block copolymers...
November 30, 2016: Nature Communications
https://www.readbyqxmd.com/read/27900830/enyne-4-4-cycloaddition-oxidation-ring-contraction-via-cyclopropanones-and-their-anionic-ring-opening-reactions
#12
Svitlana Kulyk, Buddha B Khatri, Scott McN Sieburth
Irradiation of a 1,3-enyne tethered to a 2-pyridone, in the presence of oxygen, leads to formation of a seven-membered ring product, an overall [4+4-1] reaction. This transformation involves two unstable intermediates and a sequence of unusual reactions. An initial [4+4] photocycloaddition of the enyne with the pyridone yields a 1,2,5-cyclooctatriene. Photooxidation of this triene forms a cyclopropanone and subsequent photoextrusion of carbon monoxide gives the observed 1,4-cycloheptadiene product. The first-formed cyclooctatriene and the cyclopropanone could be observed and characterized spectroscopically...
November 30, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27899930/ability-to-remove-na-and-retain-k-correlates-with-salt-tolerance-in-two-maize-inbred-lines-seedlings
#13
Yong Gao, Yi Lu, Meiqin Wu, Enxing Liang, Yan Li, Dongping Zhang, Zhitong Yin, Xiaoyun Ren, Yi Dai, Dexiang Deng, Jianmin Chen
Maize is moderately sensitive to salt stress; therefore, soil salinity is a serious threat to its production worldwide. Here, excellent salt-tolerant maize inbred line TL1317 and extremely salt-sensitive maize inbred line SL1303 were screened to understand the maize response to salt stress and its tolerance mechanisms. Relative water content, membrane stability index, stomatal conductance, chlorophyll content, maximum photochemical efficiency, photochemical efficiency, shoot and root fresh/dry weight, and proline and water soluble sugar content analyses were used to identify that the physiological effects of osmotic stress of salt stress were obvious and manifested at about 3 days after salt stress in maize...
2016: Frontiers in Plant Science
https://www.readbyqxmd.com/read/27898827/identification-of-genomic-loci-associated-with-the-photochemical-reflectance-index-by-genome-wide-association-study-in-soybean
#14
Matthew Herritt, Arun Prabhu Dhanapal, Felix B Fritschi
The photochemical reflectance index (PRI) is determined from canopy spectral reflectance measurements and can provide important information about photosynthesis. The PRI can be used to assess the epoxidation state of xanthophyll pigments, which provides information on nonphotochemical quenching (NPQ) and the amount of energy used for photosynthesis. Genome-wide association analyses were conducted to identify single-nucleotide polymorphisms (SNPs) and genomic loci associated with PRI using data from a soybean [ (L...
July 2016: Plant Genome
https://www.readbyqxmd.com/read/27896004/photolysis-of-a-peptide-with-n-peptidyl-7-nitroindoline-units-using-two-photon-absorption
#15
Kevin A Hatch, Alfredo Ornelas, Kaitlyn N Williams, Thomas Boland, Katja Michael, Chunqiang Li
N-acyl-7-nitroindolines have been used as caged compounds to photorelease active molecules by a one- or two-photon excitation mechanism in biological systems. Here, we report the photolysis of a polypeptide that contains 7-nitroindoline units as linker moieties in its peptide backbone for potential materials engineering applications. Upon two-photon excitation with femtosecond laser light at 710 nm the photoreactive amide bond in N-peptidyl-7-nitroindolines is cleaved rendering short peptide fragments. Thus, this photochemical process changes the molecular composition at the laser focal volume...
November 1, 2016: Biomedical Optics Express
https://www.readbyqxmd.com/read/27895261/photochemistry-of-framework-supported-m-diimine-co-3x-complexes-in-three-dimensional-lithium-carboxylate-metal-organic-frameworks-monitoring-the-effect-of-framework-cations
#16
Thomas J Reade, Thomas S Murphy, James A Calladine, Raphael Horvath, Ian P Clark, Gregory M Greetham, Michael Towrie, William Lewis, Michael W George, Neil R Champness
The structures and photochemical behaviour of two new metal-organic frameworks (MOFs) are reported. Reaction of Re(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Cl or Mn(2,2'-bipy-5,5'-dicarboxylic acid)(CO)3Br with LiCl or LiBr, respectively, produces single crystals of {Li2(DMF)2 [(2,2'-bipy-5,5'-dicarboxylate)Re(CO)3Cl]}n ( RELI: ) or {Li2(DMF)2[(2,2'-bipy-5,5'-dicarboxylate)Mn(CO)3Br]}n ( MNLI: ). The structures formed by the two MOFs comprise one-dimensional chains of carboxylate-bridged Li(I) cations that are cross-linked by units of Re(2,2'-bipy-5,5'-dicarboxylate)(CO)3Cl ( RELI: ) or Mn(2,2'-bipy-5,5'- dicarboxylate)(CO)3Br ( MNLI: )...
January 13, 2017: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
https://www.readbyqxmd.com/read/27895208/diurnal-solar-energy-conversion-and-photoprotection-in-rice-canopies
#17
Katherine Georgina Meacham, Xavier Sirault, W Paul Quick, Susanne von Caemmerer, Robert T Furbank
Genetic improvement of photosynthetic performance of cereal crops and increasing the efficiency with which solar radiation is converted into biomass has recently become a major focus for crop physiologists and breeders. The pulse amplitude modulated chlorophyll fluorescence technique (PAM) allows quantitative leaf level monitoring of the utilization of energy for photochemical light conversion and photo-protection in natural environments, potentially over the entire crop lifecycle. Here the diurnal relationship between electron transport rate (ETR) and irradiance was measured in five cultivars of Oryza sativa in canopy conditions with PAM fluorescence under natural solar radiation...
November 28, 2016: Plant Physiology
https://www.readbyqxmd.com/read/27895203/a-palmitic-acid-elongase-affects-eicosapentaenoic-acid-and-plastidal-monogalactosyldiacylglcerol-levels-in-nannochloropsis
#18
Lina Juana Dolch, Camille Rak, Giorgio Perin, Guillaume Tourcier, Richard Broughton, Marina Leterrier, Tomas Morosinotto, Frédérique Tellier, Jean-Denis Faure, Denis Falconet, Juliette Jouhet, Olga Sayanova, Frederic Beaudoin, Eric Marechal
Nannochloropsis species are oleaginous eukaryotes containing a plastid limited by four membranes, deriving from a secondary endosymbiosis. In Nannochloropsis, thylakoid lipids including monogalactosyldiacylglycerol (MGDG) are enriched in eicosapentaenoic acid (EPA). The need for EPA in MGDG is not understood. Fatty acids are de novo synthesized in the stroma, then converted into very-long-chain polyunsaturated fatty acids at the ER. The production of MGDG relies therefore on an EPA supply from the ER to the plastid, following an unknown process...
November 28, 2016: Plant Physiology
https://www.readbyqxmd.com/read/27892553/photochemical-co2-reduction-in-water-using-a-co-immobilised-nickel-catalyst-and-a-visible-light-sensitiser
#19
Gaia Neri, Mark Forster, James J Walsh, C M Robertson, T J Whittles, Pau Farràs, Alexander J Cowan
A dye-sensitised CO2 reduction photocatalyst that operates in water is reported. Transient spectroscopy demonstrates that the facile co-immobilisation of a Ru dye and a Ni CO2 reduction electrocatalyst enables efficient on-particle electron transfer leading to photocatalytic activity that greatly exceeds the equivalent solution based system.
November 28, 2016: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/27892544/boron-doped-diamond-semiconductor-electrodes-efficient-photoelectrochemical-co2-reduction-through-surface-modification
#20
Nitish Roy, Yuiri Hirano, Haruo Kuriyama, Pitchaimuthu Sudhagar, Norihiro Suzuki, Ken-Ichi Katsumata, Kazuya Nakata, Takeshi Kondo, Makoto Yuasa, Izumi Serizawa, Tomoaki Takayama, Akihiko Kudo, Akira Fujishima, Chiaki Terashima
Competitive hydrogen evolution and multiple proton-coupled electron transfer reactions limit photoelectrochemical CO2 reduction in aqueous electrolyte. Here, oxygen-terminated lightly boron-doped diamond (BDDL) thin films were synthesized as a semiconductor electron source to accelerate CO2 reduction. However, BDDL alone could not stabilize the intermediates of CO2 reduction, yielding a negligible amount of reduction products. Silver nanoparticles were then deposited on BDDL because of their selective electrochemical CO2 reduction ability...
November 28, 2016: Scientific Reports
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