electron spin resonance spectroscopy of singlet oxygen

Theo lý thuyết cộng hưởng ngẫu nhiên (SR) trong hệ xử lý thông tin thính giác ở động vật có vú, khi tiếng ồn nội tại được thêm vào tín hiệu dưới ngưỡng, tín hiệu ồn được tạo ra không chỉ có thể được phát hiện mà còn có thể phục hồi hoàn toàn thông tin mà tín hiệu mang theo. Tuy nhiên, với mức năng lượng tổng của tín hiệu dưới ngưỡng và tiếng ồn nội tại, rất khó để giải thích SR khi sự tăng thêm về năng lượng không đủ để nâng tín hiệu ngưỡng lên mức ngưỡng. Do đó, một giả thuyết nảy sinh là điều chế thông tin đóng một vai trò nhất định trong một số dạng SR trong hệ thống cảm giác. Tuy nhiên, cơ chế điều chế thông tin dường như không khả thi trong thính giác của động vật có vú vì đòi hỏi phải hiểu biết trước đáng kể về các đặc điểm của tín hiệu. Chúng tôi đề xuất rằng không thể chỉ dựa vào năng lượng của tín hiệu dưới ngưỡng và tiếng ồn nội tại hoặc điều chế thông tin mà phải phân tích SR. Chúng tôi lưu ý rằng một hệ thống thính giác của động vật có vú sử dụng năng lượng vào việc xử lý tín hiệu ồn. Do đó, một phần năng lượng sử dụng có thể được chuyển vào tín hiệu đã phục hồi, nâng tín hiệu lên trên ngưỡng. Chúng tôi đề xuất một mô hình biểu thị theo cách toán học chặt chẽ quan điểm lý thuyết mới này về SR trong hệ thống thính giác của động vật có vú và giải thích về mặt sinh lý cho mô hình này. Kết quả của chúng tôi cho thấy hệ thống thính giác của động vật có vú có thể chủ động hơn so với những gì trước đây đã trình bày trong tài liệu. Như đã nhận ra trước đây, khi tiếng ồn nội tại được sử dụng để tạo ra tín hiệu ồn, năng lượng mang theo bởi tiếng ồn sẽ được thêm vào tín hiệu dưới ngưỡng ban đầu. Hơn nữa, mô hình của chúng tôi dự đoán rằng, bản thân hệ thống sẽ phải đưa năng lượng bổ sung vào tín hiệu đã phục hồi. Năng lượng bổ sung được sử dụng khi xử lý tín hiệu ồn để phục hồi tín hiệu dưới ngưỡng ban đầu.

Ngày tải lên: 13/08/2014, 16:21

... Site-selective spin labelling Stochastic spin labelling Electron paramagnetic resonance Binding interaction Size exclusion chromatography Use of spin labels to study structures of polymers has ... lines represent the saturation point of molar ratio between ASP and monosaccharide of the electron spin with the strongly coupled nuclear spin of 14N (nu­ clear spin 1, ms = − 1, 0, +1) In solution ... typical for the spin probe 2.2.6 Calculation of labelling efficiency For reducing end spin labelled fibers, the spin labelling efficiency P is defined as: P= Cspin • 100% Cfiber (2) where Cspin is the

Ngày tải lên: 01/01/2023, 14:03

... timing of the examination in the investigated time window, hence could be potentially independent of postnatal age We consider the contemplation of the time-dependence of brain metabolites as one of ... enhances prediction of term infants at risk for persistent encephalopathy Pediatrics 2003;111(2):351–7 23 Blüml S Magnetic resonance spectroscopy: basics In: MR spectroscopy of pediatric brain ... kinetics of lactate production and clearance in a rat model of forebrain ischemia Biochem Cell Biol 1998;76:503–9 32 Chan KWY, Chow AM, Chan KC, Yang J, Wu EX Magnetic resonance spectroscopy of the

Ngày tải lên: 01/02/2020, 21:26

... fractions because of the low rates of electron flow through PSI in the absence of an electron donor system (Fig. 1). As P700 + is known to be a very efficient quencher of exci- ted singlet states of Chls ... produced from reactions of 1 O 2 or • OH with organic molecules [36,37]. Generation of singlet oxygen by Chl is expected dur- ing strong illumination as it depends on the population of excited Chls molecules ... DA 830 signal remained stable during the first 4 h of strong light treatment of PSI submembrane fractions in the absence of active oxygen scavengers. It indicated an unchanged amount of photooxidizable P700 during this

Ngày tải lên: 16/03/2014, 18:20

... and in the presence of CDs, diffusion coefficient of  and CDs and diffusion coefficients of water (DOH) Values of percentages of complexed 5FU with CDs 252 Magnetic Resonance Spectroscopy Studies ... and in the presence of CDs, diffusion coefficient of ,  and CDs and diffusion coefficients of water (DOH) Values of percentages of complexed MNX with CDs It turns out that D of HOD, free CD and ... Character of Benzofuroxans - Case Examples of the Reactions of Nitrobenzofuroxans with Dienes and Nucleophiles 183 M Sebban, P Sepulcri, C Jovene, D Vichard, F Terrier and R Goumont Chapter 11 NMR Spectroscopy

Ngày tải lên: 17/03/2014, 02:20

... Department of Biology, Faculty of Science, Tokyo University of Science, Tokyo, Japan 2 Institute of Biological Science, University of Tsukuba, Japan 3 Department of Biology, Faculty of Science, ... to reduce CO 2 with an endless supply of reducing equiva- lents. The release of oxygen as the byproduct of the water-splitting reaction has not only created an oxygen atmosphere but also the ozone ... appearance of oxygenic photosynthetic organisms was a key event in the evolution of our green bio- sphere. The organisms developed the machinery using solar energy to oxidize water into oxygen and

Ngày tải lên: 23/03/2014, 15:21

... The values of DG0 translat and DGrot Nrot consider the loss of translational and rotational freedom of the entire ligand molecule and the freezing of rotational degrees of freedom of the ligand ... the rate of electron transfer between two molecules depends on three factors: the overlap of the electron densities (wavefunctions) of the two molecules, the difference in redox potential of the ... interactions of the electrostatic quadrupole of aromatic rings with permanent dipoles (for example of amide bonds), the quadrupoles of other aromatic rings and the induced dipoles of methyl groups)

Ngày tải lên: 31/03/2014, 21:21

... analysis by CD and NMR spectroscopy of a peptide encompassing the amphipathic domain of YopD from Yersinia Tobias Tengel 1 , Ingmar Sethson 1 and Matthew S. Francis 2 1 Departments of Organic Chemistry ... domain of YopD. The peptide structures were examined using CD spectroscopy and 2D homonuclear/heteronuclear NMR spectroscopy. Using these peptides, the interaction between the amphipathic domain of ... an integration time of 2 s. Three spectra per sample were acquired and averaged, followed by subtraction of the CD signal of the solvent. Ellipticity is expressed in terms of mean residue molar

Ngày tải lên: 31/03/2014, 21:21

... Institute of Molecular Medicine, University of Helsinki, Finland Full list of author information is available at the end of the article options are needed To this end, gene therapy has been of interest ... main disadvantage of the current adenoviral therapies is that the efficacy of tumor transduction limits the efficacy of treatment In particular, intravenous administration of the vector does ... study 21 days after intrasplenic injection of HCT116 cells, × 10e10 VP of AdTL, AdTLGR, or AdTLRGDK in 150 μl of PBS were injected through the tail vein of NMRI nude mice After 48 hours, mice (n

Ngày tải lên: 18/06/2014, 16:20

... performed using the GraphPad Prism software (version 5.0 for Windows; GraphPad Software Inc., La Jolla, CA) Quantification of reactive oxygen species To measure the amount of free radicals generated, ... characteristics of Mexico City have a significant impact on the health of the inhabitants [12,13] In view of the mechanisms that have previously been proposed for health effects of pollution, we ... center in the city The samplers were located on the roof of a four-story building the time of the experiment; none were smokers On the morning of the experiment, patients and healthy volunteers

Ngày tải lên: 20/06/2014, 00:20

... University of Montreal Hospital Centre, Notre-Dame Hospital, Department of Medicine, University of Montreal, Montreal, Quebec, Canada of Montreal Hospital Centre, Notre-Dame Hospital, Department of Radiology, ... Radiology, University of Montreal, Montreal, Quebec, Canada 3University of Montreal Hospital Centre, Notre-Dame Hospital, Department of Physics and Biomedical Engineering, University of Montreal, Montreal, ... Therefore, the use of JSW changes in knee OA studies is such that a minimum follow-up of at least 24 months and a cohort of several thousands is necessary to establish the effect of pharmacological

Ngày tải lên: 09/08/2014, 07:20

... the extent of FcγRIIIb involvement is subject to debate. Allelic specificity of FcγRIIIb affects the efficiency of phagocy- tosis of opsonised bacteria [21,22]. FcγRIIIb exists as one of three ... minutes of the addi- tion of the dye. In addition to trypan blue staining, the apoptotic state of cells was assessed by the determination of hypodip- loid DNA, because DNA breakdown is a hallmark of ... effusion [6,7]. Depletion of neutrophils in an experi- mental model of the disease prevents the development of inflammation and decreases it once it has ensued [8]. Activa- tion of neutrophils leads

Ngày tải lên: 09/08/2014, 10:20

... stem of 100% oxygen resuscitated groups, GABAB receptors showed a significant decrease compared to control One hundred percentage of oxygen generated abnormally high levels of reactive oxygen ... protein concentration of 0.1 - 0.2 mg In saturation binding experiments, nM to 40 nM concentrations of [3H]baclofen was incubated with and without excess of unlabelled baclofen (100 μM) were used ... consequences of this on neonatal brain development [60] We observed that 100% oxygen resuscitation for neonatal hypoxia is not as effective as the combination of glucose and oxygen or administration of

Ngày tải lên: 10/08/2014, 05:21

... the mechanism of spinal cord injury after ischemia-reperfusion consists of progressive loss of motor neurons accompanied with a steady decline of motor function [3] The complexity of this mechanism ... severe oxidative stress for the spinal cord In this study we examined the influence of Amifostine, a triphosphate free oxygen scavenger, on oxidative stress of spinal cord ischemiareperfusion ... University of Patras, Patras, Greece, 2Biology Department, University of Patras, Patras, Greece, 3Department of Anaesthesiology and Critical Care Medicine, School of Medicine, University of Patras,

Ngày tải lên: 10/08/2014, 10:20

... indicating primary events of 1O2 06 0$ 6$ KRXUV KRXUV KRXUV KRXUV Figure Visualization of singlet oxygen detected with the SOSG fluorescent probe Visualization of singlet oxygen detected with the ... signalling are discussed Results Patterns of accumulation of singlet oxygen, superoxide radical and hydrogen peroxide The transfer of plantlets after weeks of growth to control and treatment media, ... the course of atrazine treatment despite the high accumulation of singlet oxygen (Fig and Additional file 1) The analysis of 1O2 responses by Gadjev et al [64] was based on studies of the Arabidopsis

Ngày tải lên: 12/08/2014, 03:20

... Merged Control Profile of fluorescence intensities Mean of fluorescence intensity (Arbitrary units) *** 0 50 100 150 200 Control BLV Analysis of DNA oxidative damageFigure 3 Analysis of DNA oxidative ... intensity of chloromethyldichlorofluorescein (CM-DCF) was detected at a wavelength of 530 nm after a laser excitation beam of 480 nm. B cell specific staining was measured at a wavelength of 650 ... through induction of apoptosis, we investigated the involvement of ROS in VPA therapy. As control, we first analyzed histone H3 acetylation in presence of a thera- peutic dose of 1 mM VPA as previously

Ngày tải lên: 12/08/2014, 23:22

... result of NADH oxidation was measured One unit of enzyme activity was defined as the reduction of lmolÆmin)1 of NADH (corresponding to the carboxylation of lmolÆmin)1 of acetyl-CoA) Quantification of ... the addition of CoA solution) The Km value for CoA of the OGOR enzyme is reported to be 80 lm [30] Thus, decarboxylation of 2-oxoglutarate can proceed as a result of CoA contamination of the acetyl-CoA ... radical is generated by one -electron transfer; one of the two electrons that are generated during decarboxylation of pyruvate remains on the TPP intermediate, and the other electron moves to the intramolecular...

Ngày tải lên: 16/02/2014, 09:20

... activation of nuclear genes by plastid signals Singlet oxygen produced in the chloroplast of the conditional fluorescent (flu) mutant was shown to stimulate the expression of a set of genes which ... 0.48 0 rel singlet oxygen production at 500 μmol photons m-2 s-1 Figure Correlation of 1O2 production and GPXH expression Singlet oxygen production was measured with SOSG in each of the 20 gox ... of singlet oxygen in vivo using a new fluorescent sensor, Singlet Oxygen Sensor Green® J Exp Bot 2006, 57:1725-1734 Baruah A, Simkova K, Apel K, Laloi C: Arabidopsis mutants reveal multiple singlet...

Ngày tải lên: 11/08/2014, 11:21

... Omission of the rose bengal, photolysis in the absence of O2, or incubation of complete samples in the absence of light, resulted in peroxide concentrations of < lM (data not shown) Stability of peptide ... inactivation of GAPDH and GR occurs via oxidation of nonactive site residues, that bring about loss of functional integrity, the stoichiometry of inactivation (i.e the loss of two molecules of thiol ... Production of singlet oxygen by eosinophils activated in vitro by C5a and leukotriene B4 FEBS Lett 453, 265268 Steinbeck, M.J., Khan, A.U & Karnovsky, M.J (1993) Extracellular production of singlet oxygen...

Ngày tải lên: 21/02/2014, 03:20

... and the magnetic moment of the unpaired electron spin In most cases, these are too small to be resolved in the EPR spectrum The electron- spin density at the positions of magnetic nuclei can be ... signals of this tensor are easily detected in proton-ENDOR spectroscopy on flavins [31,48–51] and are considered to be sensitive probes of the electron- spin density on the outer xylene ring of the ... [2] tion, the sign of the resonances directly reflects the emissive or enhanced absorptive polarization of the EPR transitions, which arises due to the generation of the electron- spin state with...

Ngày tải lên: 16/03/2014, 02:20