Article
Chemistry, Multidisciplinary
Toshinobu Nakajo, Jun Kumagai, Shinpei Kusaka, Akihiro Hori, Yuh Hijikata, Jenny Pirillo, Yunsheng Ma, Ryotaro Matsuda
Summary: Triplet carbenes (TCs) are highly reactive species with unique electronic states, making it challenging to balance reactivity and stability. By confining TCs in the nanospace of a metal-organic framework (MOF), it is possible to enhance their thermal stability while maintaining reactivity, allowing for the stabilization of highly reactive species.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2021)
Review
Engineering, Environmental
Liangjie Wang, Ke Xiao, Huazhang Zhao
Summary: This review summarizes the basic properties of singlet oxygen (1O2), its debated role in persulfate-based advanced oxidation processes (PS-AOPs), and the methods and drawbacks of identifying and evaluating its role. The aim is to better understand the role of 1O2 in PS-AOPs and facilitate its rational utilization.
Article
Chemistry, Physical
C. Lakshmi Ranganatha, H. S. Lokesha, K. R. Nagabhushana, B. S. Palakshamurthy
Summary: This study investigates the structure, photoluminescence, thermoluminescence, and optically stimulated luminescence of SrMoO4 phosphor, and analyzes its kinetics. The SrMoO4 sample has a tetragonal structure and agglomerated particles with a size of about 5.8 ± 1.2 μm. Photoluminescence exhibits a broad peak at 490 nm when excited at 288 nm. Thermoluminescence shows two peaks at 365 K and 472 K. The study provides insights into the properties and potential applications of SrMoO4.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Jing-Hang Wu, Fei Chen, Tian-Hao Yang, Han-Qing Yu
Summary: This study introduces a comprehensive kinetic examination method for spin-trapping EPR analysis to monitor the concentration of singlet oxygen (O-1(2)). It can avoid false-positive results and provide insights into the reaction mechanisms in catalytic oxidation processes.
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
(2023)
Article
Biochemistry & Molecular Biology
Yuta Suzuki, Mikio Yagi, Azusa Kikuchi
Summary: In this study, the quantum yields of singlet oxygen generation by quinine and its protonated cations were determined using time-resolved near-IR phosphorescence measurements. It was found that the protonated cations had higher quantum yields of singlet oxygen generation. The nature of the T-1 states of quinine and its protonated cations was studied through transient absorption, phosphorescence, and EPR measurements, and it was observed that the nature of the T-1 state was hardly affected by protonation.
PHOTOCHEMICAL & PHOTOBIOLOGICAL SCIENCES
(2023)
Article
Chemistry, Organic
Ryo Murata, Zhe Wang, Yuki Miyazawa, Ivana Antol, Shigeru Yamago, Manabu Abe
Summary: This study demonstrates the SOMO-HOMO conversion in triplet carbenes embedded in cycloparaphenylene units for the first time. The unique electronic configuration is attributed to the high-lying HOMO from the curved pi-conjugated system and the low-lying SOMO-1 from the small carbene angle. Additionally, planar triplet carbenes like fluorenylidene were also found to exhibit SOMO-HOMO energy-converted electronic configurations.
Article
Optics
Andrea Maurizio Monti, Maksym Buryi, Mauro Fasoli, Marco Martini
Summary: The thermal stability of the 110 degrees C TSL peak of quartz was studied in natural and synthetic samples, and compared with the [GeO4](-) paramagnetic signal with EPR. The decay rate of both signals was found to be significantly different between samples, with a couple of samples showing a drastically increased decay time beyond expected experimental fluctuations.
JOURNAL OF LUMINESCENCE
(2021)
Review
Neurosciences
Inna Gertsenshteyn, Mihai Giurcanu, Peter Vaupel, Howard Halpern
Summary: Measuring molecular oxygen levels in vivo is crucial for understanding the effects of hypoxia in normal tissues and malignant tumors. This article explores various PO2 measurements and imaging techniques, with a focus on the validation of treating hypoxic tumors with a threshold of PO2 <= 10 Torr using EPR imaging. These techniques have significant implications for studying the impact of hypoxia on normal tissues and malignant tumors.
JOURNAL OF PHYSIOLOGY-LONDON
(2021)
Article
Biotechnology & Applied Microbiology
Carolina Ehrenfeld, Valentina Veloso-Gimenez, Rocio Corrales-Orovio, Rolando Rebolledo, Mauricio P. Boric, Jose Tomas Egana
Summary: As animal cells cannot produce oxygen, erythrocytes are responsible for gas interchange, being able to capture and deliver oxygen upon tissue request. Several other cells in nature produce oxygen by photosynthesis, raising the question of whether they could circulate within the vascular networks, acting as an alternative source for oxygen delivery. This study examines the physical and mechanical features of the photosynthetic microalga Chlamydomona reinhardtii and compares them with erythrocytes, finding similarities in size and rheological properties. Furthermore, the biocompatibility of the microalgae is evaluated, showing that they can co-culture with endothelial cells without affecting each other's morphology and viability. Additionally, the systemic injection of high numbers of microalgae in mice does not trigger harmful responses, suggesting their potential as a source of oxygen delivery.
APPLIED MICROBIOLOGY AND BIOTECHNOLOGY
(2023)
Article
Multidisciplinary Sciences
Wojciech J. Nawrocki, Xin Liu, Bailey Raber, Chen Hu, Catherine de Vitry, Doran I. G. Bennett, Roberta Croce
Summary: Photosynthesis relies on sunlight for energy, but excessive light can lead to photoinhibition of the enzyme PSII, limiting photosynthesis. This study investigates the molecular origins of photoinhibition, revealing a quenching process at the PSII reaction center. The findings suggest that PSII damage and quenching may stem from the same event, shedding light on the damage-induced energy dissipation during photosynthesis.
Article
Chemistry, Physical
Osamu Inanami, Wakako Hiraoka, Yuto Goto, Hideo Takakura, Mikako Ogawa
Summary: Photoimmunotherapy (PIT) is a novel cancer therapy that utilizes tumor-specific monoclonal antibodies and a silicon phthalocyanine derivative to induce cell death through NIR-induced formation of IR700 anion radicals. Experimental results confirm the importance of these anion radicals in inducing the aggregation of IR700 and generating O-2(.-) under certain conditions.
Article
Chemistry, Physical
Andrey A. Sukhanov, Huaiman Cao, Xue Zhang, Jianzhang Zhao, Yuri E. Kandrashkin
Summary: Intramolecular charge and energy transfer processes initiated by light absorption can change the photosensitization properties of molecular conjugates. The effect of energy transfer between chromophores in a dimer and the presence of dynamic equilibrium within the dimer have been observed using transient optical and electron paramagnetic resonance (TREPR) spectroscopies.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Analytical
Hideo Utsumi, Toshiki Masumizu, Ryoma Kobayashi, Tomoko Tahira, Fuminori Hyodo, Tatsuya Shimizu, Tatsuya Naganuma, Kazunori Anzai
Summary: Free radicals are key substances in organisms but can also cause oxidative diseases. Dynamic nuclear polarization- magnetic resonance imaging is a noninvasive imaging method that can be used for in vivo free radical imaging.
ANALYTICAL CHEMISTRY
(2021)
Article
Plant Sciences
Marcel Dann, Edgardo M. Ortiz, Moritz Thomas, Arthur Guljamow, Martin Lehmann, Hanno Schaefer, Dario Leister
Summary: Iterative mutagenesis and exposure to increasing light levels led to a significant improvement in the light tolerance of a cyanobacterium strain. Over 100 mutations were identified in proteins involved in various cellular functions, indicating potential adaptations to high light intensities.
Article
Materials Science, Ceramics
J. Hrabovsky, M. Buryi, V. Babin, K. Ridzonova, K. Paurova, D. John
Summary: Charge trapping centers in two types of tellurite glasses were studied using X-ray irradiation and EPR spectroscopy. F+ centers and O- defect were discovered, and their behavior was affected by the presence of BaO. Additionally, the luminescence properties were studied using PL, RL, and TL methods, and the discovered charge trapping centers were found to influence the luminescence properties. The role of BaO was determined to support oxygen leakage.
JOURNAL OF NON-CRYSTALLINE SOLIDS
(2023)
Article
Plant Sciences
Davide Gerna, Daniel Ballesteros, Erwann Arc, Wolfgang Stoeggl, Charlotte E. Seal, Nicki Marami-Zonouz, Chae Sun Na, Ilse Kranner, Thomas Roach
Summary: Seed ageing mechanisms are influenced by the physical state of the cytoplasm. Oxygen promotes lipid peroxidation and seed viability loss when the cytoplasm is glassy, but not when it is fluid. Hypoxic conditions delay seed deterioration, lipid peroxidation, and decline of antioxidants only when the cytoplasm is glassy. When the cytoplasm is fluid, seed deterioration occurs at the same rate regardless of oxygen availability, with limited lipid peroxidation and detoxification of lipid peroxide products.
JOURNAL OF EXPERIMENTAL BOTANY
(2022)
Article
Biotechnology & Applied Microbiology
Thomas Roach, Nina Boeck, Nina Rittmeier, Erwann Arc, Ilse Kranner, Andreas Holzinger
Summary: The study reveals that the desiccation tolerance in Haematococcus pluvialis is related to the color of the cells, with red cells showing better tolerance. The mechanisms of desiccation tolerance include changes in cell ultra-structure and synthesis of astaxanthin-rich lipid bodies. The processes of acclimation to desiccation under low and high light conditions have overlapping components, such as accumulation of fatty acids, lipid bodies, and astaxanthin. Atmospheric exposure alone can trigger acclimation to desiccation, and photosynthesis powers this process, but high light stress and dehydration are not strictly necessary.
ALGAL RESEARCH-BIOMASS BIOFUELS AND BIOPRODUCTS
(2022)
Editorial Material
Plant Sciences
Thomas Roach, Eunchul Kim, Lijin Tian, Bernard Lepetit
FRONTIERS IN PLANT SCIENCE
(2022)
Article
Plant Sciences
Regina Ninoles, Dolores Planes, Paloma Arjona, Carmen Ruiz-Pastor, Ruben Chazarra, Joan Renard, Eduardo Bueso, Javier Forment, Ramon Serrano, Ilse Kranner, Thomas Roach, Jose Gadea
Summary: Understanding the genetic factors involved in seed longevity is crucial in agriculture and ecology. This study investigated the mechanisms behind differing seed longevity in Arabidopsis thaliana, revealing the importance of redox poise and stored mRNA in determining seed viability. Multiple factors contribute to seed longevity, including heat-shock factors and RNA regulation.
PLANT CELL AND ENVIRONMENT
(2022)
Article
Plant Sciences
Moritz Stegner, Johanna Wagner, Thomas Roach
Summary: Cumulative oxidative damage contributes to seed ageing. Antioxidants such as glutathione and tocochromanols can prevent damage, but tocopherol loss does not always accompany seed ageing. The study found that cell redox states were negatively correlated with seed germination, while tocochromanol concentrations were positively correlated.
SEED SCIENCE RESEARCH
(2022)
Article
Microbiology
Davide Gerna, David Clara, Dorothee Allwardt, Birgit Mitter, Thomas Roach
Summary: Seeds provide a niche for endophytic bacteria, but the interaction between seeds and their endophytes is not well understood. This study designed various media to mimic the endosphere of germinating soybean seeds and found that the embryonic axis had higher richness and more unique genera compared to the cotyledons. The use of tailored media helped uncover the trophic adaptation of core taxa. The results also showed that the parental environment influenced seed endophytic diversity. The extended diversity of native seed endophytic bacteria revealed the functional relevance of certain strains to seed germination under salt stress.
MICROBIOLOGY SPECTRUM
(2022)
Meeting Abstract
Biochemistry & Molecular Biology
Nora Went, Carolina Gnaiger, Sabine Schmitt, Rafael Moreno-Sanchez, Thomas Roach, Erich Gnaiger
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2022)
Article
Plant Sciences
Ginga Shimakawa, Anja Krieger-Liszkay, Thomas Roach
Summary: In plants, senescence is associated with the production of reactive oxygen species (ROS) and lipid peroxidation. However, lipid peroxidation is not solely linked to stress, as it also plays a role in plant development. The major polyunsaturated fatty acid (PUFA) in senescing leaves is linolenic acid, which is sensitive to peroxidation. Lipid catabolism during senescence leads to a decrease in PUFA levels and an increase in short-chain saturated fatty acids.
PHYSIOLOGIA PLANTARUM
(2022)
Article
Plant Sciences
Marine Messant, Umama Hani, Thais Hennebelle, Florence Guerard, Bertrand Gakiere, Andrew Gall, Sebastien Thomine, Anja Krieger-Liszkay
Summary: This study investigates the effects of excess and deficiency of manganese on chloroplast ultrastructure and photosynthetic electron transport in the liverwort Marchantia polymorpha, an emerging model system.
Article
Plant Sciences
Richard Peter Beckett, Thomas Roach, Farida Minibayeva, Silke Werth
Summary: The photosynthetic apparatus of lichen photobionts, including cyclic electron flow and photoprotection, was studied using chlorophyll fluorescence analysis and near-infrared absorption. Sun species exhibited lower PSI acceptor side limitation and higher flavodiiron-mediated pseudocyclic electron flow compared to shade species. Melanised lichens had lower Y[NA], higher NDH-2-type cyclic flow, and higher non-photochemical quenching, while shade species displayed faster relaxing NPQ. Cyclic electron flow was a prominent feature in all lichens regardless of habitat.
PHYSIOLOGIA PLANTARUM
(2023)
Article
Biochemistry & Molecular Biology
Thomas Roach, Gilbert Neuner, Ilse Kranner, Othmar Buchner
Summary: Heat and drought stresses are important topics in the context of climate change, especially in the Alps. A study found that alpine plants can gradually adapt to heat and achieve maximum tolerance within a week. The antioxidant mechanisms of Primula minima leaves that were heat hardened without or with additional drought stress were investigated. The results showed a weakened low-molecular-weight antioxidant defense but increased activity of antioxidant enzymes, particularly under drought conditions.
Article
Plant Sciences
Marine Messant, Umama Hani, Thanh-Lan Lai, Adjele Wilson, Ginga Shimakawa, Anja Krieger-Liszkay
Summary: In this study, the role of plastid terminal oxidase PTOX in protecting photosystem I and II was investigated using PTOX mutants in two model plants. The results show that PTOX plays a dual role as both a pro-oxidant and an antioxidant in vivo.
Meeting Abstract
Biochemistry & Molecular Biology
Pablo Albertos, Immaculada Sanchez-Vicente, Jose Manuel Franco, Roberto Solano, David Gerna, Thomas Roach, Wolfgang Stoggl, Ilse Kranner, Julio Salina, Oscar Lorenzo
FREE RADICAL BIOLOGY AND MEDICINE
(2022)
Meeting Abstract
Biochemistry & Molecular Biology
Pablo Albertos, Maria Immaculada Sanchez-Vicente, Jose Manuel Franco, Roberto Solano, David Gerna, Thomas Roach, Wolfgang Stoggl, Ilse Kranner, Julio Salina, Oscar Lorenzo
FREE RADICAL BIOLOGY AND MEDICINE
(2022)
Article
Biochemistry & Molecular Biology
Brandon P. Russell, David J. Vinyard
Summary: The Mn4CaO5 oxygen-evolving complex in Photosystem II is crucial for water oxidation. D1 residue R334 participates in proton release and interacts with PsbO. A D1-R334G mutant destabilizes the OEC but stabilizes the S2 intermediate.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Alexander A. Bulychev, Tatiana S. Strelets
Summary: Excitable cells of higher plants and characean algae respond to stressful stimuli by generating action potentials that influence chlorophyll fluorescence and photosynthesis for an extended period of time. While plant leaves exhibit a reversible depression in the efficiency of photosystem II reaction after an individual action potential, characean algae show long-lasting oscillations of photosystem II reaction efficiency after firing an action potential. This study investigates the possible mechanisms behind these oscillations and suggests that they are a result of metabolic rearrangements in chloroplasts and the cyclosis cessation-recovery cycle induced by calcium influx during action potentials. The findings also indicate that fluidic communications between different cell regions play a role in these oscillations, and the inhibition of oscillations occurs when these communications are restricted or eliminated.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Dmitry Zlenko, Elena A. Protasova, Georgy Tsoraev, Nikolai N. Sluchanko, Dmitry A. Cherepanov, Thomas Friedrich, Baosheng Ge, Song Qin, Eugene G. Maksimov, Andrew B. Rubin
Summary: The conformation of chromophores in isolated phycobiliproteins is heterogeneous, but not in the entire phycobilisome (PBS). Under low-energy excitation, there is no significant uphill energy transfer from the core to the peripheral rods of the PBS, while transfer from the terminal emitters to bulk allophycocyanin chromophores is highly probable.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)
Article
Biochemistry & Molecular Biology
Makio Yokono, Chiyo Noda, Jun Minagawa
Summary: This paper investigates the energy transfer between Photosystem II and Photosystem I in Arabidopsis thaliana, and finds that the fast spillover is reversibly regulated depending on pH.
BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS
(2024)