Academic literature on the topic 'Methylene oxidation'

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Journal articles on the topic "Methylene oxidation"

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Urgoitia, Garazi, Raul SanMartin, María Herrero, and Esther Domínguez. "Recent Advances in Homogeneous Metal-Catalyzed Aerobic C–H Oxidation of Benzylic Compounds." Catalysts 8, no. 12 (December 8, 2018): 640. http://dx.doi.org/10.3390/catal8120640.

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Csp3–H oxidation of benzylic methylene compounds is an established strategy for the synthesis of aromatic ketones, esters, and amides. The need for more sustainable oxidizers has encouraged researchers to explore the use of molecular oxygen. In particular, homogeneous metal-catalyzed aerobic oxidation of benzylic methylenes has attracted much attention. This account summarizes the development of this oxidative strategy in the last two decades, examining key factors such as reaction yields, substrate:catalyst ratio, substrate scope, selectivity over other oxidation byproducts, and reaction conditions including solvents and temperature. Finally, several mechanistic proposals to explain the observed results will be discussed.
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Lupaşcu, T., M. Ciobanu, V. Boţan, and A. Nistor. "Catalytic Oxidation of Methylene Blue." Chemistry Journal of Moldova 5, no. 2 (December 2010): 37–40. http://dx.doi.org/10.19261/cjm.2010.05(2).04.

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The intact activated carbon CAN-8, obtained from nutshells by activation with water vapours, in the presence of oxygen and at relatively low temperatures, possesses catalytic activity, caused by the presence of alkaline functional groups on its surface, as well as by the formation, in these experimental conditions, of the OH radical, which has a high oxidation potential. After 25 cycles of the process of methylene blue oxidation, the data of chromatographic analyses indicate the presence of three organic components in the solution.
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Zhao, Jinpeng, Takeshi Nanjo, Emilio C. de Lucca, and M. Christina White. "Chemoselective methylene oxidation in aromatic molecules." Nature Chemistry 11, no. 3 (December 17, 2018): 213–21. http://dx.doi.org/10.1038/s41557-018-0175-8.

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Lupaşcu, T., M. Ciobanu, O. Bogdevici, and V. Boţan. "Products Derived from Catalytic Oxidation of Methylene Blue." Chemistry Journal of Moldova 6, no. 1 (June 2011): 77–80. http://dx.doi.org/10.19261/cjm.2011.06(1).07.

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It was established that the process of catalytic oxidation of methylene blue, at low concentrations (20 mg/L), i.e. in real solutions, gives sulfates and nitrates and new product, which can be categorized, in their vast majority, as impurities, probably got from the vacuum distillation unit, which make up for only ~ 10 % of methylene blue used in the experiment. Methylene blue adsorption at the interface occurs in real solutions. In case of performing the process at methylene blue concentration of 120 mg/L, hemi-micelles are adsorbed at the interface and the OH• radical acts more effectively due to the presence at the interface of a greater number of dye molecules.
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KANG, M. "Methylene chloride oxidation on oxidative carbon-supported chromium oxide catalyst." Applied Catalysis A: General 266, no. 2 (July 2004): 163–72. http://dx.doi.org/10.1016/j.apcata.2004.02.041.

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Stoyanova, Maria, and Stoyanka Christoskova. "Catalytic degradation of methylene blue in aqueous solutions over Ni- and Co- oxide systems." Open Chemistry 9, no. 6 (December 1, 2011): 1000–1007. http://dx.doi.org/10.2478/s11532-011-0086-7.

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AbstractThe oxidative catalytic degradation of the cationic dye methylene blue (MB) with NaOCl in aqueous solutions was studied using individual and iron modified Ni- and Co-oxide systems as catalysts. The adsorption extent and the contribution of the uncatalyzed oxidation on the overall degree of MB were determined. The results indicate that methylene blue—a representative of a class of dyestuffs resistant to biodegradation—could be successfully decolorized and degraded using nickel and cobalt oxide catalysts at room temperature. The highest catalytic activity manifests in the Co-oxide system which is consistent with the adsorption data. The oxidative degradation reaction proceeds via first-order kinetics. Temperature has a relatively small effect on the methylene blue degradation kinetics. The results obtained reveal that the catalysts investigated are suitable for oxidative destruction of methytlene blue dye in wastewaters.
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Perez-Benito, Joaquin F., and Donald G. Lee. "Oxidation of hydrocarbons. 15. A study of the oxidation of alkenes by methyltributylammonium permanganate." Canadian Journal of Chemistry 63, no. 12 (December 1, 1985): 3545–50. http://dx.doi.org/10.1139/v85-582.

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A study of the reduction of methyltributylammonium permanganate by a large number of alkenes in methylene chloride has dispelled a current uncertainty concerning the nature of the inorganic product obtained. It is colloidal manganese dioxide and not a manganate(V) cyclic diester as previously supposed. This product is stabilized in methylene chloride solutions by adsorption of the alkene, which decreases its polarity at the solvent interphase. The solubility of the colloid is therefore a function of both the concentration and the identity of the alkene. In certain (atypical) cases, where acidic compounds are present, the product is further reduced to manganese(III).
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Sodeau, John R., and Lynden J. Whyte. "Oxidation of methylene in low-temperature matrices." Journal of the Chemical Society, Faraday Transactions 87, no. 23 (1991): 3725. http://dx.doi.org/10.1039/ft9918703725.

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Casarotto, Marco G., and Gerald J. Smith. "Methylene-blue-sensitized photo-oxidation of terpenes." Journal of Photochemistry 40, no. 1 (September 1987): 87–91. http://dx.doi.org/10.1016/0047-2670(87)87047-8.

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Shafikova, Elza U., Elena M. Tsyrlina, Leonid V. Spirikhin, Alsu A. Balandina, Shamil K. Latypov, Marat S. Yunusov, and Oleg G. Sinyashin. "Oxidative Transformations of Lappaconitine and 19-Oxolappaconine, Structural Revision of an obtained 8,9-Seco Product." Natural Product Communications 3, no. 10 (October 2008): 1934578X0800301. http://dx.doi.org/10.1177/1934578x0800301001.

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The oxidative transformations of lappaconitine and 19-oxolappaconine were studied. The product of oxidation of the latter with K2Cr2O7/30% H2SO4 in methylene chloride was proved to be 10,12-dihydro-8,9-seco-19-oxolappaconine in contrast to the earlier proposed structure of this compound.
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Dissertations / Theses on the topic "Methylene oxidation"

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Smith, Kristen Colleen. "Surface processes ruthenium film growth, silicon nanocrystal synthesis, and methylene partial oxidation /." Access restricted to users with UT Austin EID Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3035980.

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Meyer, Jerry Christopher. "Oxidation chemistry and kinetics of model compounds in supercritical water : glucose, acetic acid, and methylene chloride." Thesis, Massachusetts Institute of Technology, 1993. http://hdl.handle.net/1721.1/12396.

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Acerson, Mark Jeffrey. "Synthesis of 4'-Ester Resveratrol Analogues, Chromium Trioxide Oxidation of Terpenes, and Synthesis of Mimics of (-)-Englerin A." BYU ScholarsArchive, 2014. https://scholarsarchive.byu.edu/etd/5458.

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4’ -ester analogues of resveratrol were synthesized using reaction conditions developed to produce mono-ester products in the presence of two other unprotected phenols. Basic conditions were employed to deprotonate the most acidic 4’ phenol followed by addition of anhydrides or acid chlorides to give the ester product. The reaction favored 4’-ester formation in polar aprotic solvents with DMSO being the optimal solvent. (—)-Englerin A is a guaiane-type sesquiterpene containing two ester side chains. Mimics of (—)-englerin A were proposed that retained the ester side chains while replacing the non-polar core with less complicated structures. These proposed mimic cores would maintain the three-dimensional positioning of the esters which are responsible for the anti-cancer activity of (—)-englerin A. Three mimics were synthesized using the bicyclic terpenes borneol and fenchol. Installation of the second ester on the terpene core was accomplished throught the development and optimization of a unique methylene oxidation using chromium trioxide in glacial acetic acid. These mimics were screened against two kidney cancer cell lines. The compounds were shown to have IC50 (inhibitory concentration for 50 % of cells) values above 30 µM.
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Polshakov, Dmitrii Arkadyevich. "Ultrafast spectroscopy and dynamics of nitrenes and carbenes." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1130968887.

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Muritu, John Waititu. "Oxidative addition reactions and methylene-bridged diiridium complexes." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape3/PQDD_0013/MQ59855.pdf.

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Dias, Gustavo Carvalho. "Geração de linhagens celulares HEK293 knockdown para as proteínas p53, ATM, mTOR e PGC1α e estudo do papel de p53 na resposta ao estresse oxidativo provocado por azul de metileno." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-29042014-143702/.

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O DNA é um alvo constante de modificações químicas, as quais resultam na ativação dos programas de reparo de danos no DNA. O DNA mitocondrial (DNAmt), uma molécula circular contendo aproximadamente 16,6 kb de extensão, é constantemente exposto às espécies reativas de oxigênio (EROs) devido a sua proximidade da cadeia transportadora de elétrons, presente na membrana mitocondrial interna. Quase todas as vias de reparo de DNA presentes no núcleo atuam também na mitocôndria, entretanto, a regulação das vias mitocondriais não é bem compreendida. As proteínas p53, ATM, mTOR e PGC1α participam, dentre outros papéis, do controle do metabolismo energético e das respostas a lesões no DNA nuclear. Dessa forma, decidimos gerar linhagens celulares com níveis reduzidos dessas proteínas como uma ferramenta para o estudo dos seus papéis na manutenção do DNAmt. Para isso, foram geradas linhagens celulares de HEK293 expressando constitutivamente shRNAs alvo-específicos, cuja diminuição da expressão das proteínas alvo foi confirmada através de western blotting. Neste trabalho, também foi estudado o papel de p53 na resposta ao estresse oxidativo mitocondrial provocado por azul de metileno (AM). O AM é um corante fotoativo capaz de atravessar membranas biológicas e, em células de mamíferos, se acumula em organelas, tais como a mitocôndria. Uma vez que p53 participa de diversas funções celulares e transloca para a mitocôndria sob condições de estresse, onde pode induzir apoptose ou modular o reparo de DNAmt, nós investigamos se p53 está envolvido na indução de morte celular após tratamento com AM fotoativado. Para isso, foram utilizados 2 clones com níveis reduzidos de p53 obtidos na primeira etapa deste trabalho. Sob condições normais, foi demonstrado que o silenciamento de p53 induziu uma forte redução do número de cópias de DNAmt e estimulou a proliferação celular quando fornecemos glicose ou galactose como substratos energéticos. A depleção de p53, ou a sua inibição farmacológica, resultaram em uma ligeira proteção quando as células foram submetidas ao tratamento com AM. Também foi demonstrado que AM provoca morte celular apoptótica de uma maneira dependente de p53, uma vez que a depleção dessa proteína protegeu a população do acúmulo de células em sub-G1. Portanto, nossos resultados sugerem que AM induz morte celular apoptótica em células HEK293, de uma maneira dependente de p53. Esse efeito pode ser mediado diretamente por p53, ou ainda, pelo seu papel na manutenção do número de cópias do DNAmt.
DNA is constantly being chemically modified, which results in activation of the DNA damage response program. The mitochondrial DNA (mtDNA), a circular molecule of 16.6 kb in length, is primary target of reactive oxygen species (ROS) due its proximity to the electron transport chain, in the mitochondrial inner membrane. Almost all known DNA damage repair pathways operating in the nucleus were also found in the mitochondrion; however, their regulation remains not well understood. The proteins p53, ATM, mTOR e PGC1α have many cellular functions, including control of energy metabolism and cell fate after stress. Thus, we hypothesized that those proteins could participate in maintaining of mtDNA, through direct or indirect roles. To test this hypothesis, we generated isogenic knockdown cell lines to further use them to study their role in the mtDNA damage response. For that, were generated HEK293 knockdown cell lines that stably express target-specific shRNAs. Efficient knockdown was checked using western blotting. Here, we also studied the role of p53 in the cellular response to mitochondrial oxidative stress induced by methylene blue (MB). MB is a photoactive dye that crosses biological membranes due to its lypophylic character and, in mammalian cells, accumulates in organelles such as mitochondria; however, its cytotoxic mechanism is not well understood. As the p53 protein participates in several cellular functions and translocates to mitochondria under stress conditions, where it can induce apoptosis or modulate mtDNA repair, we investigated whether p53 was involved in MB + light-induced cell death using p53 knockdown clones selected from the cell lines generated in the first phase of this work. Under normal conditions, p53 knockdown caused a decrease in mtDNA copy number and stimulated cellular growth supported by either glucose or galactose. After MB treatment, p53-kd cells showed a slight decrease in cell death compared to scrambled shRNA controls. Evaluation of cell death after MB treatment, using flow cytometry analysis, indicated that MB was able to induce significant levels of apoptotic cell death, which was dependent on p53 levels. Taken together, our results suggest that MB induces cell death, probably via apoptosis, in a p53 dependent manner. This effect may be mediated by p53 directly or by its role in mtDNA copy number maintenance.
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Okolongo, Gauthier Nganda. "Advanced oxidative water treatment process using an electrohydraulic discharge reactor and TiO2 immobilised on nanofibres." Thesis, University of Western Cape, 2013. http://hdl.handle.net/11394/3329.

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Philosophiae Doctor - PhD
The aim of this study was to design and build an electrohydraulic discharge reactor in such a way that the synthetic immobilized TiO2 nanophotocatalytic components could be integrated, for the production of active species such as OH radicals, ozone and hydrogen peroxide, as a cocktail to clean drinking water without the addition of chemicals. The research objectives include: • To design and construct the different AOP prototypes based on various electrode configurations and compare their operation. • To optimize the discharge parameters and conditions of the best AOP system. • To determine the effectiveness of the best prototype for the degradation of methylene blue as model pollutant. • To compare the designed AOP system with the Sodis method for the disinfection of contaminated river water. • To prepare supported TiO2 nanoparticles via electro spinning, followed by combustion and study the effect on the morphology of TiO2 nanoparticles. • To determine the stability and robustness of composite nano-crystalline TiO2 photocatalysts by sonication • To determine the enhanced effect of combining the composite TiO2 in the AOP system on degradation of methylene blue under the same conditions. • To detect the active species promoting disinfection.
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Barin, Luisa Machado. "PAPEL DA TERAPIA FOTODINÂMICA ANTIMICROBIANA ADJUVANTE AO TRATAMENTO PERIODONTAL SOB PARÂMETROS DE ESTRESSE OXIDATIVO PLASMÁTICO E COMPORTAMENTO VASCULAR." Universidade Federal de Santa Maria, 2015. http://repositorio.ufsm.br/handle/1/6159.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
The aim of this study was to evaluate the effects of methylene blue (MB) photosensitizer (PS) solubilized in ethanol in antimicrobial photodynamic therapy (aPDT) as an adjuvant periodontal treatment, at oxidative stress (OS) parameters and vascular behavior in rat model. Besides, investigate greater involvement of angiogenesis at the destruction or healing stages of periodontal disease (PD). One hundred and twenty male adult Wistar rats were divided randomly into five groups. The control groups were negative control (NC) (no PD, n=15) and positive control (PC) (with PD, without any treatment, n=15). The other groups had PD and underwent different types of treatment, such as scaling and root planing (SRP) and irrigation with 1mL of saline solution (SRP, n=30); SRP and aPDT with MB solubilized in water (aPDT I, n=30); SRP and aPDT with MB containing ethanol (aPDT II, n=30). The PD was induced via the installation of a ligature around the mandibular right first molar. After 7 days, the ligature was removed and animals received treatment. At 7, 15 and 30 days, rats were euthanized and the gingival tissue surrounding the induction area was removed for histomorphometric analysis of the number and diameter of blood vessels by staining with hematoxylin and eosin (H&E). The collected blood was centrifuged and the plasma was used to determine lipid peroxidation by quantifying thiobarbituric acid reactive substances (TBARS), vitamin C (VIT C) and glutathione reduced (GSH) levels. The oxidative status showed higher TBARS levels in PC group in 7, 15 and 30 days, and indicated a protective influence of aPDT II on plasma observed from lower lipid peroxidation. GSH levels were consumed in PC, aPDT I and aPDT II groups throughout the experiment. Furthermore, aPDT II also increased antioxidant defenses in plasma: i) higher levels of GSH, and ii) increased levels of VIT C. Interestingly, the VIT C plasmatic levels were restored in the aPDT II group in the 30th experimental day. Histomorphometric findings in 7 days showed that treated groups (SRP, aPDT I and aPDT II) showed higher number of blood vessels, and the aPDT II group showed the highest values among them. From these results, aPDT modifies PD course, reducing oxidative systemic damage and stimulating the antioxidant defense system, thus protecting the areas closely affected by PD in rats. Moreover, was observed a relationship between increased expression of angiogenesis and repair stage of the PD. In summary, we suggest that the aPDT with MB solubilized in ethanol provides better therapeutic responses in periodontal treatment.
O objetivo deste estudo foi avaliar os efeitos do fotossensibilizador (Fs) azul de metileno (AM) solubilizado em etanol na terapia fotodinâmica antimicrobiana (TFDa) como um tratamento periodontal adjuvante, sob parâmetros de estresse oxidativo (EO) e de comportamento vascular em modelo de rato. Bem como, investigar o maior envolvimento da angiogênese no estágio de avanço ou reparo da doença periodontal (DP). Cento e vinte ratos Wistar adultos machos foram randomizados e divididos em cinco grupos. Os grupos controles eram controle negativo (CN) (sem DP, n = 15) e controle positivo (CP) (com DP, sem qualquer tratamento, n = 15). Os demais grupos apresentavam DP e foram submetidos a diferentes tipos de tratamentos, como raspagem e alisamento radicular (RAR) e irrigação com 1 mL de solução salina (RAR, n = 30); RAR e TFDa com AM solubilizado em água (TFDa I, n = 30); RAR e TFDa com AM contendo etanol (TFDa II, n = 30). A DP foi induzida através da colocação de uma ligadura ao redor do primeiro molar inferior direito. Após 7 dias, a ligadura foi removida e os animais receberam tratamento. Aos 7, 15 e 30 dias, os ratos foram eutanasiados e o tecido gengival circundante à área de indução foi removido para análise histomorfométrica do número e diâmetro dos vasos sanguíneos através da coloração com Hematoxilina e Eosina (HE). O sangue recolhido foi centrifugado e o plasma foi utilizado para determinar os níveis de peroxidação lipídica mensurados pelas substâncias reativas ao ácido tiobarbitúrico (TBARS), vitamina C (VIT C) e glutationa reduzida (GSH). O status oxidativo demostrou maiores níveis de TBARS no grupo CP em 7, 15 e 30 dias, e indicou uma influência protetora da TFDa II no plasma observada a partir de menor peroxidação lipídica. Níveis de GSH foram consumidos nos grupos CP, TFDa I e TFDa II durante o experimento. Ainda, TFDa II também aumentou as defesas antioxidantes no plasma: a) níveis mais elevados de GSH, e b) aumento dos níveis de VIT C. Interessantemente, os níveis plasmáticos de VIT C foram restaurados no grupo TFDa II no trigésimo dia experimental. Os achados histomorfométricos mostraram em 7 dias que os grupos tratados (RAR, TFDa I e TFDa II) apresentaram elevado número de vasos sanguíneos, e o grupo TFDa II apresentou os maiores valores entre eles. A partir destes resultados, fica evidente que TFDa modifica a DP, reduzindo o dano oxidativo sistêmico, e estimula o sistema de defesa antioxidante, protegendo, assim, as zonas afetadas intimamente pela DP em ratos. Além disso, foi observado uma relação entre a maior expressão da angiogênese e o estágio de reparo da DP. Em síntese, sugerimos que a TFDa com AM solubilizado em etanol proporciona melhores respostas terapêuticas no tratamento periodontal.
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Santos, Nayra Fernandes. "Relação entre estresse oxidativo fotoinduzido e morte celular autofágica." Universidade de São Paulo, 2014. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-01102014-090745/.

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A Terapia Fotodinâmica (TFD) é uma modalidade terapêutica promissora que tem mostrado resultados clínicos efetivos, a lém de custo benefício favorável ao sistema de saúde. Embora a TFD esteja associada à indução de morte celular por necrose e, ou apoptose, pesquisas recentes comprovam a ativação da autofagia. Visando entender a relação entre a quantidade de espécies reativas de oxigênio (EROs), produzidas após fotoativação dos fotossensibilizadores (FSs), com a indução de morte autofágica, foram utilizados os FSs fenotiazínicos estruturalmente semelhantes, azul de metileno (MB) e 1,9-dimetil azul de metileno (DMMB); as linhagens celulares HeLa e HaCat, como modelos biológicos e LEDs emitindo em 633 nm, como fonte luminosa. Os ensaios de viabilidade em função da dose de luz e da concentração dos FSs verificaram que o aumento de morte celular está diretamente relacionado ao aumento da concentração e ao aumento da dose de luz, para ambos FSs. Verificou-se que nas condições de IC50 a concentração do DMMB (10 nmol/L) é menor que a do MB (2,0 µmol/L) em duas ordens de grandeza, e essa diferença também se reflete no grau de desbalanço oxidativo gerado após fotossensibilização. Foi verificado que para o MB, a elevada geração de EROs está fortemente correlacionada com a perda de viabilidade, enquanto que para o DMMB essa correlação é fraca, uma vez que há perda de sobrevida sem grandes gerações de EROs. No entanto, a diminuição de sobrevida causada pelo DMMB se correlaciona forte e significativamente ao aumento da autofagia, indicando ocorrência de morte celular autofágica tanto em células HaCaT quanto em células HeLa. As análises de dano em organelas indicaram que ambos FSs, após serem fotoativados, causam danos em lisossomas e em mitocôndrias de células HaCaT. E confirmou-se, por ensaio de localização subcelular, que ambos FSs estão nessas organelas. Uma vez que a localização subcelular do FS influencia no mecanismo de morte celular foto desenvolvido, verificou-se que o MB nas mesmas concentrações nanomolares do DMMB não induz autofagia, pois o mesmo encontra-se fotoquimicamente inativo nas mitocôndrias, devido à redução pelas coenzimas presentes nesta organela. O DMMB possui um potencial de redução menor que o MB, o que impede a redução deste FS nas mitocôndrias, e, mesmo em baixas concentrações, o DMMB é capaz de comprometer a integridade de mitocôndrias e lisossomas, e induz ir autofagia como um mecanismo de morte celular. As condições em que o MB não se encontra totalmente reduzido no ambiente celular são em concentrações mais elevadas, nas quais a geração do nível de estresse oxidativo é maior e não se observa resposta autofágica após fotossensibilização. Esses resultados mostram que a eficiência de morte celular causada por TFD não está necessariamente relacionada ao nível de estresse oxidativo gerado, uma vez que o DMMB induziu estresse oxidativo em menor extensão do que MB e, no entanto, induziu morte celular em maior extensão. Confirmou-se o conceito de que, fotossensibilizadores mais eficazes para a TFD devem resultar da melhoria na especificidade das reações de fotossensibilização nos alvos celulares e não apenas em melhoria na eficiência de geração de ERO.
Photodynamic Therapy (PDT) is a promising therapeutic modality that has shown effective clinical outcomes and benefits in terms of costs to the national health system. Although PDT is associated with induction of cell death by necrosis or apoptosis, recent data suggest the activation of autophagy. In order to understand the relationship between reactive oxygen species (ROS), generated after light activation of photosensitizers (PSs), and the autophagic cell death induction, we have used two phenothiazines with similar structure - methylene blue (MB) and 1,9-dimethyl methylene blue (DMMB); HaCaT and HeLa cells were used as biological models and LEDs emitting at 633 nm were used as light source. Cell viability assays as function of light dose and PS concentration showed that the increase in cell death was directly proportional to the PS concentration and light dose, to the both PSs. At IC50 was verified that DMMB concentration (10 nmol/L) is lower than MB concentration (2,0 µmol/L) in two order of magnitude, and this difference is reflected in degree of oxidative stress promoted by photosensitizers . Only for MB the amount of detected ROS is highly correlated with loss of cell viability, while for DMMB this correlation is weak, because there is loss of viability without large generation of ROS. Nevertheless, the viability decreased for DMMB is highly correlated with the increase of autophagy, indicating occurrence of autophagic cell death in both HaCaT cells and in HeLa cells. The analyses of damaged cell organelles indicated that both PSs, after be photoactivated, induce lysosomal and mithochondrial damage in HaCaT cells. And the subcellular localization assay confirmed that DMMB and MB are localized in these organelles. Because the subcellular localization of PSs influences cell death mechanisms, this research identified that MB, in the same nanomolar concentration of DMMB, does not induce autophagy, because it is photochemically inactive in mitochondria due the reducing coenzymes present in this organelle. DMMB has a lower reduction potential than MB, which hinders PS reduction in mitochondria, and possibly generate a mild oxidative stress that compromise the integrity of mitochondria and lysosomes, and justify autophagy induction as a cell death mechanism. The conditions that MB is not fully reduced in the cellular environment are at higher concentrations, in which was detected high level of oxidative stress and autophagic cell death was not observed after photosensitization. These results show that the efficiency of cell death induced by PDT is not necessarily related with oxidative stress level, since the oxidative stress induced by DMMB was lesser than by MB, however, the cell death was greater. This research confirms the concept that more effective photosensitizers for PDT means greater specificity of photosensitization reactions, and not only improvement of the efficiency of ROS generation.
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Checchia, Robert Garcia. "Estudo de propriedades biofísicas de membrana sob estresse oxidativo e a interação com proteínas formadoras de poros." Universidade de São Paulo, 2019. http://www.teses.usp.br/teses/disponiveis/43/43134/tde-21032019-171115/.

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Neste trabalho investigamos efeitos de fotoirradiação e toxinas sob membranas celulares miméticas. Foram utilizadas, como modelo de membranas lipídicas, vesiculas unilamelares gigantes (GUVs) compostas pro lipídeos oxidados e não oxidados observadas por microscopia ótica de contraste de fase. Inicialmente estudamos a foto-resposta de membranas compostas por POPC e POPG dispersas em solução contendo azul de metileno (MB). Na sequência, estudamos o efeito de toxinas formadoras de poros, Esticolisina I (ST I) e Esticolisina II (ST II), em membranas contendo lipídeos oxidados e não oxidados. Os resultados de MB (10 µM) disperso em solução de membranas compostas por POPC e o lipídeo aniônico POPG indicaram que o aumento da densidade de carga negativa nas membranas das GUVs, que favorece a ligação da moléculas positivamente carregadas como MB nas membranas, tem como consequência um aumento de permeabilidade da membrana muito mais rápído em relação a membranas compostas apenas por POPC. Isto se deve ao fato que a localização preferencial do MB na membrana de POPC:POPG favorece a formação de oxigênio singlete próximo a dupla ligação da cadeia alquílica, dando início a reação de peroxidação lipídica de maneira mais efetiva que em membrana de POPC. Os resultados da ação das toxinas STI e STII (21 nM) em GUVs contendo lipídeos não oxidados PC e esfingomielina evidenciam que apenas STII é capaz de permear estas membranas a esta concentração. Mais ainda, nossos resultados sugerem que a existência de separação de fases fluida-gel na bicamada lipidica composta por PC:SM (razão molar 1:1) favorece a ação da toxina StII. Ao analisarmos membranas contendo lipídeos hidroperoxidados (POPC-OOH) dispersas em solução contendo STII (21 nM) observamos um aumento de permeabilidade na membrana num conjunto de GUVs, associado a formação de poros, apenas em bicamadas lipídicas formadas por misturas de lipídeos oxidados (POPC) e não oxidados (POPC-OOH). Quanto maior a concentração de lipídeos oxidados na membrana mais rapidamente ocorre o aumento de permeabilidade.
In this work we investigate the effects of photoirradiation and toxins on mimetic cell membranes. As a model of lipid membranes, giant unilamellar vesicles (GUVs) composed of oxidized and oxidized pro-lipids were observed by optical phase contrast microscopy. Initially we studied the photo-response of membranes composed of POPC and POPG dispersed in solution containing methylene blue (MB). Following, we studied the effect of pore-forming toxins, Sticolysin I (ST I) and Sticolysin II (ST II), on membranes containing oxidized and non-oxidized lipids. The results of MB (10 M) dispersed in solution of membranes composed of POPC and the anionic lipid POPG indicated that the increase in the negative charge density in the membranes of GUVs, which favors the binding of positively charged molecules as MB in the membranes, consequently increases membrane permeability in regard to membranes composed only of POPC. This is due to the fact that the preferred location of the MB in the POPC: POPG membrane favors the formation of singlet oxygen near the double bond of the alkyl chain, initiating the lipid peroxidation reaction more effectively than in the POPC membrane. The results of the action of the STI and STII toxins (21 nM) on GUVs containing non oxidised lipids PC and sphingomyelin show that only STII is able to permeate these membranes at this concentration. Moreover, our results suggest that the existence of fluid-gel phase separation in the lipid bilayer composed of PC:SM (molar ratio 1:1) favors the action of the StII toxin. When analyzing membranes containing hydroperoxidized lipids (POPC-OOH) dispersed in solution containing STII (21 nM) we observed an increase in membrane permeability in a set of GUVs, associated with pore formation, only in lipid bilayers formed by mixtures of oxidized lipids (POPC-OOH) and non-oxidized ones. The higher the concentration of oxidized lipids in the membrane, the faster the permeability increases.
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Book chapters on the topic "Methylene oxidation"

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Shaw, Henry, Yi Wang, Tia-Chiang Yu, and Anthony E. Cerkanowicz. "Catalytic Oxidation of Trichloroethylene and Methylene Chloride." In ACS Symposium Series, 358–79. Washington, DC: American Chemical Society, 1993. http://dx.doi.org/10.1021/bk-1993-0518.ch017.

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Marrone, Philip A., Russell P. Lachance, Joanna L. DiNaro, Brian D. Phenix, Jerry C. Meyer, Jefferson W. Tester, William A. Peters, and K. C. Swallow. "Methylene Chloride Oxidation and Hydrolysis in Supercritical Water." In Innovations in Supercritical Fluids, 197–216. Washington, DC: American Chemical Society, 1995. http://dx.doi.org/10.1021/bk-1995-0608.ch013.

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Hamidani, Meriem, Souad Djerad, and Lakhdar Tifouti. "Oxidation of Methylene Blue by Copper via a Heterogeneous Fenton-Like Process." In Recent Advances in Environmental Science from the Euro-Mediterranean and Surrounding Regions (2nd Edition), 219–23. Cham: Springer International Publishing, 2021. http://dx.doi.org/10.1007/978-3-030-51210-1_37.

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Tallapaka, Ajit Kumar, Jyothi Thati, and Sailu Chintha. "Oxidative Photocatalytic Degradation of Methylene Blue in Wastewater." In Recent Trends in Waste Water Treatment and Water Resource Management, 119–27. Singapore: Springer Singapore, 2020. http://dx.doi.org/10.1007/978-981-15-0706-9_12.

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Sobkowiak, Andrzej, Aimin Qiu, Xiu Liu, Antoni Llobet, and Donald T. Sawyer. "Copper(I)/(t-BuOOH)-Induced Activation of Dioxygen for the Ketonization of Methylenic Carbons." In The Activation of Dioxygen and Homogeneous Catalytic Oxidation, 481. Boston, MA: Springer US, 1993. http://dx.doi.org/10.1007/978-1-4615-3000-8_72.

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Landais, Y., and J. M. Vincent. "Oxidation of Active Methylene Compounds." In Ketones, 1. Georg Thieme Verlag KG, 2005. http://dx.doi.org/10.1055/sos-sd-026-00591.

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Black, D. StC. "Oxidation of α-Methylene Substituents." In Fully Unsaturated Small-Ring Heterocycles and Monocyclic Five-Membered Hetarenes with One Heteroatom, 1. Georg Thieme Verlag KG, 2001. http://dx.doi.org/10.1055/sos-sd-009-00660.

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Murphy, P. J. "Oxidation of 4-Methylene-4-telluropyrans." In Six-Membered Hetarenes with One Chalcogen, 1. Georg Thieme Verlag KG, 2003. http://dx.doi.org/10.1055/sos-sd-014-01179.

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Taber, Douglass F. "Oxidation and Reduction." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0011.

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Kiyotomi Kaneda of Osaka University devised (Angew. Chem. Int. Ed. 2010, 49, 5545) gold nanoparticles that efficiently deoxygenated an epoxide 1 to the alkene 2. Robert G. Bergman of the University of California, Berkeley, and Jonathan A. Ellman, now of Yale University, reported (J. Am. Chem. Soc. 2010, 132, 11408) a related protocol for deoxygenating 1,2-diols. Dennis A. Dougherty of Caltech established (Org. Lett. 2010, 12, 3990) that an acid chloride 3 could be reduced to the phosphonate 4. Pei-Qiang Huang of Xiamen University effected (Synlett 2010, 1829) reduction of an amide 5 by activation with Tf2O followed by reduction with NaBH4. André B. Charette of the Université de Montreal described (J. Am. Chem. Soc. 2010, 132, 12817) parallel results with Tf2O/Et3SiH. David Milstein of the Weizmann Institute of Science devised (J. Am. Chem. Soc. 2010, 132, 16756) a Ru catalyst for the alternative reduction of an amide 7 to the amine 8 and the alcohol 9. Shi-Kai Tian of the University of Science and Technology of China effected (Chem. Commun. 2010, 46, 6180) reduction of a benzylic sulfonamide 10 to the hydrocarbon 11. Thirty years ago, S. Yamamura of Nagoya University reported (Chem. Commun. 1967, 1049) the efficient reduction of a ketone to the corresponding methylene with Zn/HCl. Hirokazu Arimoto of Tohoku University established (Tetrahedron Lett. 2010, 51, 4534) that a modified Zn/TMSCl protocol could be used following ozonolysis to effect conversion of an alkene 12 to the methylene 13. José Barluenga and Carlos Valdés of the Universidad de Oviedo effected (Angew. Chem. Int. Ed. 2010, 49, 4993) reduction of a ketone to the ether 16 by way of the tosylhydrazone 14. Kyoko Nozaki and Makoto Yamashita of the University of Tokyo and Dennis P. Curran of the University of Pittsburgh found (J. Am. Chem. Soc. 2010, 132, 11449) that the hydride 18 (actually a complex dimer) could effect the direct reduction of a halide 17 and also function as the hydrogen atom donor for free radical reduction and as the hydride donor for the Pd-mediated reduction of an aryl halide.
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Taber, Douglass F. "Best Synthetic Methods: Oxidation." In Organic Synthesis. Oxford University Press, 2013. http://dx.doi.org/10.1093/oso/9780199965724.003.0009.

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Karl A. Scheidt of Northwestern University described (Organic Lett. 2009, 11, 1651) the oxidation of primary alcohols such as 1 in the presence of an indole 2. The product 3, an active acylating agent, is readily converted to other esters and amides. K. Rajender Reddy of the Indian Institute of Chemical Technology, Hyderabad, developed (Tetrahedron Lett. 2009, 50, 2050) a protocol for the direct oxidation of a primary amine 4 to the corresponding nitrile 5. In the presence of ammonia, the same procedure converted aldehydes and primary alcohols into the nitriles. Several catalytic methods for the oxidation of alcohols to aldehydes and ketones have recently been put forward. René Grée of the Université de Rennes 1 found ( Tetrahedron Lett. 2009, 50, 1493) that ZnBr2 catalyzed the oxidation of alcohols with diethyl azodicarboxylate. Tsutomu Katsuki of Kyushu University designed (Tetrahedron Lett. 2009, 50, 3432) a Ru catalyst for the air oxidation of primary alcohols to aldehydes. Kazuaki Ishihara of Nagoya University showed (J. Am. Chem. Soc. 2009, 131, 251) that 1 mol % of 10 was sufficient to catalyze the oxidation of 6 to 7. With excess oxidant, 7 was carried on cleanly to 11. Nitroxyl radicals such as TEMPO have long been used to catalyze oxidations. Yoshiharu Iwabuchi of Tohoku University developed (J. Org. Chem. 2009, 74, 4619) a simple preparation of 13 , the most efficient such catalyst reported so far. This catalyst should also be useful for the oxidation reported by Professor Iwabuchi (Chem. Commun. 2009, 1739) of primary alcohols and aldehydes to the corresponding carboxylic acids. David S. Forbes of the University of South Alabama prepared (Tetrahedron Lett. 2009, 50, 1855) 16 by combining thioanisole with N-bromosuccinimide. The reagent 16 efficiently sulfenylated active methylene compounds. Jiri Srogl of the Academy of Sciences of the Czech Republic established (Organic Lett. 2009, 11, 843) conditions for the oxidation of primary and secondary amines to aldehydes and ketones. Olga A. Ivanova of Moscow State University demonstrated (Tetrahedron Lett. 2009, 50, 2793) that DMDO 21 could oxidize a sensitive amino cyclopropane such as 20 to the corresponding nitro compound.
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Conference papers on the topic "Methylene oxidation"

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Zhang, Yi, Yan Luo, Jian-Qiang Hu, Tao Zhang, and Yun-Yun Xu. "Study on Antioxidation Properties of the Complex of Dithiocarbamate With Tolutriazole Antioxidant." In ASME/STLE 2007 International Joint Tribology Conference. ASMEDC, 2007. http://dx.doi.org/10.1115/ijtc2007-44020.

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The antioxidation properties of methylene bis(di-n-butyldithiocarbamate) (V 7723) - and tolutriazole derivative (V 887) - containing poly-a-olefin (PAO)-derived lubricants were evaluated by differential scanning calorimetry (DSC) and modified penn state micro-oxidation test (PMOT). DSC test measures incipient oxidation temperature (OT) and oxidation induction time (IT) of the lubricant at high temperatures and the oxidation stability of oil weight loss is measured by PMOT test. DSC test shows that OT and IT of V 7723-containing PAO were improved significantly by V 887 addition. PMOT test indicates that when combining with V 7723 antioxidants, V 887 can also effectively reduce the increase in weight loss of PAO. In addition, FTIR results from PMOT test confirm that addition of V 887 can significantly enhance the oxidation induction time of oils. These results suggest that the V 7723 shows a good oxidative synergism with V 887 antioxidant.
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Qing, Li. "Kinetic Mechanism of Photo-catalytic Oxidation for Soluble Methylene Blue by Iron-doped TiO2." In 2012 International Conference on Computer Distributed Control and Intelligent Environmental Monitoring (CDCIEM). IEEE, 2012. http://dx.doi.org/10.1109/cdciem.2012.99.

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Rokhima, Ummu, Henry Setiyanto, Muhammad Zulfikar, Vienna Saraswaty, and Nandang Mufti. "Study of Methylene Blue Degradation Using Mediated Electrochemical Oxidation With Ce (IV) Ions: Effect of Supporting Electrolyte, Ce (III) Concentration, and Oxidation Potential." In Proceedings of the 7th Mathematics, Science, and Computer Science Education International Seminar, MSCEIS 2019, 12 October 2019, Bandung, West Java, Indonesia. EAI, 2020. http://dx.doi.org/10.4108/eai.12-10-2019.2296387.

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Chou, P., K. Lee, and IM Adcock. "Oxidative Stress Induces Nuclear Export of the Histone Methylase Suv39H1 a Glucocorticoid Receptor Co-Repressor Protein." In American Thoracic Society 2009 International Conference, May 15-20, 2009 • San Diego, California. American Thoracic Society, 2009. http://dx.doi.org/10.1164/ajrccm-conference.2009.179.1_meetingabstracts.a1957.

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Lei, Wen, Chao Ren, Tao Huang, and Lei Lei. "Enhancement of thermo-oxidative aging resistance of ramie fiber/HDPE composites using tetrakis[methylene(3,5-di-tert-butyl-4-hydroxyhydrocinnamate)]methane as antioxidant." In 2011 International Conference on Consumer Electronics, Communications and Networks (CECNet). IEEE, 2011. http://dx.doi.org/10.1109/cecnet.2011.5769261.

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Zheng, Mary Minyi, Britney Harris, James Woods, David Colby, and Julia Kirshner. "Abstract B30: 15-Methylene-Eburnamonine: A preventative agent against breast to brain metastases by targeting circulating tumor cells and cancer stem cells through induction of oxidative stress." In Abstracts: Twelfth Annual AACR International Conference on Frontiers in Cancer Prevention Research; Oct 27-30, 2013; National Harbor, MD. American Association for Cancer Research, 2013. http://dx.doi.org/10.1158/1940-6215.prev-13-b30.

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