• For maximum PTT/PDT synergistic efficacy, the concentration of photosensitizers and nanogold required optimization, besides the wavelength of the light matching the absorption peak of PS and nanogold, and the sequential order of PTT and PDT process. (crimsonpublishers.com)
  • External supply of either photosensitizers or oxygen concentration will significantly improve the anti-cancer efficacy via type-II PDT. (crimsonpublishers.com)
  • We covered topics going from the photochemical mechanisms involved, the different cell death mechanisms being triggered by a myriad of photosensitizers up to the more recent-on-going clinical trials. (oaepublish.com)
  • The origin of widely used division of photodynamic processes into type I and type II and the relation of these processes to the nature of the primary photochemical reactions of photosensitizers are discussed. (msu.ru)
  • When photosynthetic antenna pigments such as chlorophyll are excited by light absorption, unproductive reactions may occur by charge transfer to molecules with unpaired electrons. (wikipedia.org)
  • The main way to improve photosynthetic efficiency is to optimize the light reactions, including increasing light absorption and conversion, accelerating the recovery of non-photochemical quenching, modifying enzymes in the Calvin cycle, introducing carbon concentration mechanisms into C 3 plants, rebuilding the photorespiration pathway, de novo synthesis, and changing stomatal conductance. (encyclopedia.pub)
  • The process of photosynthesis can be basically divided into two stages: light and dark reactions. (encyclopedia.pub)
  • The light reactions of photosynthesis are the starting points of the whole photosynthesis process, providing adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide phosphate (NADPH) as the energy sources for the subsequent dark reactions, and part of the ATP and NADPH generated enters the photorespiratory pathway. (encyclopedia.pub)
  • Photodynamic therapy (PDT) involves the use of photochemical reactions mediated through the interaction of photosensitizing agents, light, and oxygen for the treatment of malignant or benign diseases. (medscape.com)
  • Excited-state proton transfer reactions II. (typeset.io)
  • Excited-state intramolecular proton transfer reactions are reviewed. (typeset.io)
  • In Type I, light energy passes from excited molecules to biomolecules through electron/hydrogen transfer (radical mechanism) in direct-contact reactions [Figure 1] and culminates in specific damage to biomolecules and in the initiation of radical chain reactions. (oaepublish.com)
  • Successful time-resolved crystallography studies have used the pump-probe approach, and the light-induced X-ray crystallographic difference densities have been assigned to reactions and excited-state processes. (nature.com)
  • B) The use of photochemical reagents to carry out site-specific reactions on DNA, in particular those involving photo-induced electron transfer. (tcd.ie)
  • This review presents the recent progress of oxygen functionalization reactions based on non-electrochemical (conventional organic synthesis) and electrochemical methods. (rsc.org)
  • We hope to direct the attention of readers to the latest breakthroughs of traditional oxygen functionalization reactions and to the potential of electrochemistry for the transformation of organic substrates to useful end products. (rsc.org)
  • During his postdoctoral research at the Massachusetts Institute of Technology (MIT), he studied the electrochemical oxygen functionalization reactions. (rsc.org)
  • His research focuses on the fundamental understanding of electrochemical reactions and organic electrosynthesis including various oxygen-atom functionalization catalysis, asymmetric synthesis, biochemical reactions. (rsc.org)
  • New definitions of these reactions are proposed on the basis of the mechanisms of oxygen photoactivation. (msu.ru)
  • The author has contributed to research in topics: Triplet state & Phosphorescence. (typeset.io)
  • Transfer of Triplet State Energy in Fluid Solutions. (typeset.io)
  • I. Sensitized Phosphorescence and Its Application to the Determination of Triplet State Lifetimes. (typeset.io)
  • Photoprotection is the biochemical process that helps organisms cope with molecular damage caused by sunlight. (wikipedia.org)
  • Because singlet oxygen does not travel very far within a cell, the molecular effects are influenced by the intracellular localization of the photosensitizer at the time of light exposure. (medscape.com)
  • REVIEW: Primary Mechanisms of Photoactivation of Molecular Oxygen. (msu.ru)
  • Then, the discovery of photodynamic action is described, which was shown to result from pigment photosensitized activation of molecular oxygen. (msu.ru)
  • A conception stating that molecular oxygen is chemically rather passive and special activation mechanisms are needed to involve it into chemical and biological processes appeared in the scientific literature in the middle of XIX century. (msu.ru)
  • We represent how these fascinating advertisements assign from high download Financial Derivatives: Pricing and Risk Management of the buffalo to the years, and assist natural, single physics for Looking this different industry in reactive Molecular uncertainties ranks. (pikespeakconstruction.com)
  • error and molecular great textbook of a due behavior is precomputed which permits used by a reactive 5-Inch excipient of initial applications. (pikespeakconstruction.com)
  • The dramatic history of mechanistic studies of oxygen photoactivation is reviewed starting from the Bach-Engler peroxidation theory to the hypothesis of moloxide, discovery of singlet oxygen and free radicals and, then, to modern views on the primary photoactivation processes. (msu.ru)
  • The structural dynamics that result from femtosecond optical excitation have contributions from vibrational and electronic processes and from reaction dynamics that involve the crossing through a conical intersection. (nature.com)
  • However, we demonstrate that the measured motions are not part of the photoisomerization reaction but instead arise from impulsively driven coherent vibrational processes in the electronic ground state. (nature.com)
  • Absorption of blue light by the dark-adapted state (D 450 ) prompts the LOV receptor to traverse short-lived excited singlet (S 1 ) and triplet (T 1 ) states before assuming the light-adapted state (S 390 ), which is characterized by a thioadduct between the flavin atom C4a and the sidechain of a conserved cysteine. (nature.com)
  • Electrons released in this process are transferred to carbon dioxide and lead to synthesis of carbohydrates. (boloji.com)
  • Atmospheric carbon dioxide gets fixed in the biological system as energy-rich carbohydrates As a result carbon dioxide content of the atmosphere in the prebiotic era came down and oxygen content increased to stabilize at the present level. (boloji.com)
  • Photosynthesis refers to the process in which autotrophs convert light energy from the sun into chemical energy to convert inorganic carbon into complex organic carbon and release oxygen. (encyclopedia.pub)
  • Carbon assimilation is the carbon-reaction stage of photosynthesis, which is essentially a process of inorganic carbon fixation and conversion to organic carbon. (encyclopedia.pub)
  • Trends in the SOA oxygen to carbon ratio (O : C) for OFR and SC were related to different OH exposures, but divergences in the H : C remained unexplained. (copernicus.org)
  • The particles became highly reactive chemically in the presence of the energy of electromagnetic rays and high temperature. (boloji.com)
  • Photosynthesis is the largest mass- and energy-conversion process on Earth, and it is the material basis for almost all biological activities. (encyclopedia.pub)
  • Fuels formed by biological processes and transformed into solid or fluid minerals over geological time. (encyclopedia.com)
  • S pilled oil is transported, and its composition and character altered, by a variety of physical, chemical, and biological processes ( Figure 4-1 ). (nationalacademies.org)
  • Oxygen atom functionalization has played an indispensable role in industrial applications and biological processes. (rsc.org)
  • Perovskite-type semiconductor materials present excellent photocatalytic properties due to sufficient oxygen vacancies and variable metal valence. (biomedcentral.com)
  • Likely via a radical-pair mechanism 12 , T 1 reacts within microseconds to the signaling state, characterized by a covalent thioadduct between a highly conserved cysteine residue in the LOV photosensor and the C4a atom of the flavin isoalloxazine ring system. (nature.com)
  • In eukaryotic phototrophs, these mechanisms include non-photochemical quenching mechanisms such as the xanthophyll cycle, biochemical pathways which serve as "relief valves", structural rearrangements of the complexes in the photosynthetic apparatus, and use of antioxidant molecules. (wikipedia.org)
  • The photo-chemical properties of this radiation had enriched the covering layer of the earth with highly reactive molecules which were kept far away from a state of chemical equilibrium. (boloji.com)
  • Among these reactive particles, arose such groups of molecules, in very small quantities, which were autocatalytic. (boloji.com)
  • Oxygen released as a consequence of breakup of water molecules got dispersed in the atmosphere. (boloji.com)
  • The process in which pigment molecules produce electrons by capturing solar energy is called photosynthetic electron transport (PET). (encyclopedia.pub)
  • A term peroxide I apply to those oxygen-containing compounds whose function is similar to that of hydrogen peroxide and whose molecules contain at least one -O-O- group. (msu.ru)
  • Mechanisms may also act on a longer time-scale, such as up-regulation of stress response proteins or down-regulation of pigment biosynthesis, although these processes are better characterized as "photoacclimatization" processes. (wikipedia.org)
  • In this paper, the intrinsic processes and mechanisms of proton transfer in relation to the nature of the intramolecular hydrogen bond ring are reviewed. (typeset.io)
  • But the authors focus on the intrinsic process and not the mechanisms of transfer. (typeset.io)
  • Special emphasis is given to the intrinsic processes and to the mechanisms of proton transfers in relation to the nature of the intramolecular hydrogen bond ring. (typeset.io)
  • As previously stated, PDT involves the photosensitized oxidation of biomolecules which can be separated in two mechanisms. (oaepublish.com)
  • The peroxidation theory formulated independently by A. N. Bach and C. Engler in 1897 was an important step in understanding mechanisms of oxygen activation [ 2 - 4 ]. (msu.ru)
  • Initially, Bach was interested in mechanisms of CO 2 fixation and oxygen evolution in photosynthesis. (msu.ru)
  • In organisms that perform oxygenic photosynthesis, excess light may lead to photoinhibition, or photoinactivation of the reaction centers, a process that does not necessarily involve chemical damage. (wikipedia.org)
  • Optimizing the process of photosynthesis is essential for survival when environmental conditions are ideal and acclimation when environmental conditions are severe. (wikipedia.org)
  • Photosynthetic activity has enabled a large accumulation of organic matter and oxygen on Earth. (encyclopedia.pub)
  • Atmospheric processing was simulated using the PSI mobile smog chamber (SC) and the potential aerosol mass oxidation flow reactor (OFR). (copernicus.org)
  • Presence of Oxygen was doubtful. (boloji.com)
  • Presence of oxygen in the atmosphere led to the development of ozone layer. (boloji.com)
  • The second step involves the activation of the photosensitizer in the presence of oxygen with a specific wavelength of light directed toward the target tissue. (medscape.com)
  • Thus a oxidation-reduction process resulting into transfer and storage of energy got entrenched in the system. (boloji.com)
  • Activation of oxygen might occur due to intermediate formation of peroxides, which always appear during slow oxidation processes, no matter what is the nature of the oxidizing compound. (msu.ru)
  • Signaling without glutamine appears intrinsic to light-oxygen-voltage receptors, which pertains to biotechnological applications and suggests evolutionary descendance from redox-active flavoproteins. (nature.com)
  • The progress of electrochemical methods toward oxygen functionalization is presented by an in-depth discussion of different types of electrically driven-chemical organic synthesis, with particular attention to recently developed electrochemical systems and catalyst designs. (rsc.org)
  • For example, epoxides are versatile chemical intermediates that have been mainly produced from the oxygen functionalization of olefin substrates. (rsc.org)
  • In these processes, a tricoordinate boronic ester initially serves as a protective group for a sugar-derived 1,2- or 1,3-diol motif, permitting functionalization of free OH groups. (acs.org)
  • In a second step, addition of a Lewis base generates a tetracoordinate adduct, which serves as an activating group, enabling functionalization of one of the boron-bound oxygen atoms by a second electrophile. (acs.org)
  • Metastasis are characterized by a sequential and complex process during which cancer cells invade specific organs including lung, liver, brain, and bone [ 3 ] . (oaepublish.com)
  • Processes for site-selective, sequential functionalizations of carbohydrate derivatives are described. (acs.org)
  • Similar SMLM techniques include Photoactivated Localization Microscopy ( PALM) and Ground State Depletion Individual Molecule Return ( GSDIM) , among many others. (microscopyu.com)
  • The transformation from passive to active oxygen can only occur owing to decomposition of the oxygen molecule (O=O). It is obvious that destruction of one of these bonds and transformation of O=O into -O-O- requires less energy than the destruction of two bonds [ 2 ]. (msu.ru)
  • Public Health and Emerging Carcinogens: Recent changes to the disinfection processes fundamental to drinking and recreational water safety are creating a host of highly toxic byproducts linked to bladder cancer. (stanford.edu)
  • We seek to understand how these compounds form so we can adjust the disinfection process to prevent their formation. (stanford.edu)
  • Fig. 1: Photochemistry of light-oxygen-voltage receptors and sequences of proteins under study. (nature.com)
  • Corral, I. "Disclosing the role of C4-oxo substitution in the photochemistry of DNA and RNA pyrimidine monomers: Formation of photoproducts from the vibrationally-excited ground state", J. Phys. (case.edu)
  • Structures of a light-oxygen-voltage paradigm at around 1 Å resolution revealed highly similar light-induced conformational changes, irrespective of whether the glutamine is present. (nature.com)
  • Electrons located in the outer orbit of such particles got excited by the solar energy and were displaced from their orbitals and were transferred to such catalytic particles, which were able to accept electrons from relatively higher energy level. (boloji.com)
  • Combustion processes create tiny particles called particulate matter (PM) that is classified as fine (PM 2.5 ) when it is 2.5-0.1 micrometers in diameter. (nih.gov)
  • from this stage, the excited electron may undergo a spin flip in a process known as intersystem crossing (ISC, S 1 → T 1 ) to form a triplet excited state. (encyclopedia.pub)
  • and to eliminate all process wastewater discharges into the Sound. (scienceagogo.com)
  • Presence of free oxygen in the atmosphere was a fatal pollution for the then organisms which were anaerobes. (boloji.com)
  • Other flavin-associated proteins may also be excited by visible light and could contribute to either light sensing and signaling or light toxicity, the latter through photosensitization and ROS production [ 11 , 12 ]. (biomedcentral.com)
  • As a result, he claimed the following: Organic food products--carbohydrates, lipids, and proteins--which are consumed by a living organism are fully oxidized in it by oxygen during a relatively short time. (msu.ru)
  • This proved to be a development of far reaching consequence Processes of conversion of simple inorganic compounds to an array of complex organic compounds were established. (boloji.com)
  • The singlet oxygen threshold dose for PDT and cell viability are governed by the product of PS concentration and light dose. (crimsonpublishers.com)
  • In nature as in biotechnology, light-oxygen-voltage photoreceptors perceive blue light to elicit spatiotemporally defined cellular responses. (nature.com)
  • In its absence, several light-oxygen-voltage receptors invariably retained productive, if often attenuated, signaling responses. (nature.com)
  • Naturally occurring, glutamine-deficient light-oxygen-voltage receptors likely serve as bona fide photoreceptors, as we showcase for a diguanylate cyclase. (nature.com)
  • a Photocycle of light-oxygen-voltage (LOV) receptors. (nature.com)
  • Crespo-Hernández, C. E. "Excited State Dynamics of Dibenzothiophene Derivatives", J. Phys. (case.edu)
  • Crespo-Hernández, C. E. "Excited State Dynamics of Dibenzothiophene Derivatives", ChemRxiv 2023, https://doi.org/10.26434/chemrxiv-2023-kwwr2. (case.edu)
  • Crespo-Hernández, C. E., "Excited State Dynamics of 2'-Deoxyisoguanosine and Isoguanosine in Aqueous Solutions", Phys. (case.edu)
  • submitted as part of the Special Issue "Ultrafast Dynamics in Chemical Processes" . (case.edu)
  • For example, most cyanobacteria possess an Orange Carotenoid Protein (OCP), which serves as a novel form of non-photochemical quenching. (wikipedia.org)
  • In this paper, the decay of donor luminescence in a rigid solution when modified by electronic energy transfer by the exchange mechanism is treated theoretically, and the rate constant for the elementary process of energy transfer is taken to be of the Dexter form, const exp(−2R/L), where R is the donor-acceptor distance and L is a positive constant. (typeset.io)
  • The rate constant for the elementary process of energy transfer is taken to be of the Dexter form, const exp(−2R/L), where R is the donor-acceptor distance and L is a positive constant. (typeset.io)
  • A form of precipitation that is significantly more acidic than neutral water, often produced as the result of industrial processes. (encyclopedia.com)
  • To educate and train students to have a sound knowledge of chemical compounds and processes. (edu.ng)
  • However, these organic compounds are almost indifferent to free or passive oxygen. (msu.ru)
  • This shop contains to the energy of the business of problem regulation 2D studies via the ppb of Photochemical Metal Organic Deposition( PMOD). (taido-hannover.de)
  • An equally conserved, proximal glutamine processes the resultant flavin protonation into downstream hydrogen-bond rearrangements. (nature.com)
  • Her research interests include the advanced materials processing of ideal electrode materials for electrochemical energy storage system applications such as supercapacitor, water splitting process, direct methanol fuel cells, and hydrogen generation. (rsc.org)
  • must have a mechanism that causes activation of oxygen, which comes from the atmosphere. (msu.ru)
  • substances will Join Lagrangian to be each processing, working a periodic protonolysis as for the call of it, they may account standard both real and shock-fitted, they may Then as isolate toward subsiding a concentration and was themselves. (taido-hannover.de)
  • NIEHS research uses state-of-the-art science and technology to investigate the interplay between environmental exposures, human biology, genetics, and common diseases to help prevent disease and improve human health. (nih.gov)
  • The atmosphere is a mixture of gases that includes about 78% nitrogen and 21% oxygen at Earth's surface. (encyclopedia.com)
  • Other fluorinated gases-such as sulfur hexafluoride that has escaped from applications in electric power equipment and perfluorocarbons that have escaped from aluminum processing and the manufacture of semiconductors-are also found in trace amounts in the atmosphere. (encyclopedia.com)
  • b) Strong laser excitation pushes most fluorophores to a dark state, from which single fluorophores may stochastically return to an emissive state (highlighted in yellow), the centroid position identified (illustrated by black crosses), and finally mapped in a single composite super-resolution reconstruction (f). (microscopyu.com)
  • A coherent-control experiment using a two-colour and two-pulse optical excitation strongly amplifies the X-ray crystallographic difference density, while it fully depletes the photoisomerization process. (nature.com)
  • Use of chemical dispersants changes the relative importance of these processes, affecting the fate of the oil, and altering subsequent ecological effects. (nationalacademies.org)
  • and (4) industrial process control. (nsf.gov)
  • STORM and other SMLMs are conceptually similar techniques: the photochemical properties of the fluorophore are exploited to induce a weakly emissive or non-emissive "dark" state. (microscopyu.com)
  • We seek to understand ways of engineer this process in ways to minimize harmful byproduct formation. (stanford.edu)
  • In the latter case, excited-state motion may not contribute substantially to measurements made with short observation delays, because the product accumulates thermally by barrier crossing throughout the excited-state lifetime. (nature.com)