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Netto CG, Toma HE, Andrade LH. Superparamagnetic nanoparticles as versatile carriers and supporting materials for enzymes. ACTA ACUST UNITED AC 2013. [DOI: 10.1016/j.molcatb.2012.08.010] [Citation(s) in RCA: 177] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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52
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Burrows MC, Zamarion VM, Filippin-Monteiro FB, Schuck DC, Toma HE, Campa A, Garcia CRS, Catalani LH. Macromol. Biosci. 12/2012. Macromol Biosci 2012. [DOI: 10.1002/mabi.201290042] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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53
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Netto CG, Nakamura M, Andrade LH, Toma HE. Improving the catalytic activity of formate dehydrogenase from Candida boidinii by using magnetic nanoparticles. ACTA ACUST UNITED AC 2012. [DOI: 10.1016/j.molcatb.2012.03.021] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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54
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Burrows MC, Zamarion VM, Filippin-Monteiro FB, Schuck DC, Toma HE, Campa A, Garcia CRS, Catalani LH. Hybrid Scaffolds Built From PET and Collagen as a Model For Vascular Graft Architecture. Macromol Biosci 2012; 12:1660-70. [DOI: 10.1002/mabi.201200154] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2012] [Revised: 07/23/2012] [Indexed: 11/11/2022]
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55
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Parussulo ALA, Iglesias BA, Toma HE, Araki K. Sevenfold enhancement on porphyrin dye efficiency by coordination of ruthenium polypyridine complexes. Chem Commun (Camb) 2012; 48:6939-41. [PMID: 22673846 DOI: 10.1039/c2cc31173a] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Sevenfold enhancement of photoconversion efficiency was achieved by incorporation of peripheral ruthenium complexes to a porphyrin dye, generating supramolecular effects capable of playing several key roles (e.g., transferring energy to, inhibiting aggregation, and accepting the hole generated in the porphyrin center after electron injection), providing new insights for the design of better DSSC photosensitizers.
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Lalli PM, Iglesias BA, Toma HE, de Sa GF, Daroda RJ, Silva Filho JC, Szulejko JE, Araki K, Eberlin MN. Protomers: formation, separation and characterization via travelling wave ion mobility mass spectrometry. JOURNAL OF MASS SPECTROMETRY : JMS 2012; 47:712-719. [PMID: 22707163 DOI: 10.1002/jms.2999] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Travelling wave ion mobility mass spectrometry (TWIM-MS) with post-TWIM and pre-TWIM collision-induced dissociation (CID) experiments were used to form, separate and characterize protomers sampled directly from solutions or generated in the gas phase via CID. When in solution equilibria, these species were transferred to the gas phase via electrospray ionization, and then separated by TWIM-MS. CID performed after TWIM separation (post-TWIM) allowed the characterization of both protomers via structurally diagnostic fragments. Protonated aniline (1) sampled from solution was found to be constituted of a ca. 5:1 mixture of two gaseous protomers, that is, the N-protonated (1a) and ring protonated (1b) molecules, respectively. When dissociated, 1a nearly exclusively loses NH(3) , whereas 1b displays a much diverse set of fragments. When formed via CID, varying populations of 1a and 1b were detected. Two co-existing protomers of two isomeric porphyrins were also separated and characterized via post-TWIM CID. A deprotonated porphyrin sampled from a basic methanolic solution was found to be constituted predominantly of the protomer arising from deprotonation at the carboxyl group, which dissociates promptly by CO(2) loss, but a CID-resistant protomer arising from deprotonation at a porphyrinic ring NH was also detected and characterized. The doubly deprotonated porphyrin was found to be constituted predominantly of a single protomer arising from deprotonation of two carboxyl groups.
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Iglesias BA, Hörner M, Toma HE, Araki K. 5-(1-(4-phenyl)-3-(4-nitrophenyl)triazene)-10,15,20-triphenylporphyrin: a new triazene-porphyrin dye and its spectroelectrochemical properties. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424612004501] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The new triazene-porphyrin dye 5-(1-(4-phenyl)-3-(4-nitrophenyl)triazene)-10,15,20-triphenylporphyrin, encompassing a reactive protonated triazene moiety, was prepared starting from meso-tetraphenylporphyrin ( H2TPP ), first converting it to the 5-(4-nitrophenyl)-10,15,20-triphenylporphyrin, then reducing to the 5-(4-aminophenyl)-10,15,20-tri(phenyl)porphyrin intermediate, and reacting with the diazonium salt of 4-nitroaniline; and characterized by spectroscopic and electrochemical methods. The absorption spectrum of the neutral species resembled the sum of H2TPP and of 1,3-bis(4-nitrophenyl)triazene spectrum, but the deprotonated anionic species showed more delocalized frontier orbitals, behaving as a push-pull system exhibiting triazenide-to-porphyrin charge-transfer transitions.
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58
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Deda DK, Pavani C, Caritá E, Baptista MS, Toma HE, Araki K. Correlation of photodynamic activity and singlet oxygen quantum yields in two series of hydrophobic monocationic porphyrins. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424611004336] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The photodynamic properties of eight hydrophobic monocationic methyl and ruthenium polypyridine complex derivatives of free-base and zinc(II) meso-triphenyl-monopyridylporphyrin series were evaluated and compared using HeLa cells as model. The cream-like polymeric nanocapsule formulations of marine atelocollagen/xanthan gum, prepared by the coacervation method, exhibited high phototoxicity but negligible cytotoxicity in the dark. Interestingly, the formulations of a given series presented similar photodynamic activities but the methylated free-base derivatives were significantly more phototoxic than the respective ruthenated photosensitizers, reflecting the higher photoinduced singlet oxygen quantum yields of those monocationic porphyrin dyes.
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Toma SH, Santos JJ, Velho RG, Nakamura M, Toma HE, Araki K. Electrochemically activated coordenative assembly of a triruthenium cluster metallopolymer. Electrochim Acta 2012. [DOI: 10.1016/j.electacta.2012.01.098] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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60
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Huila MFG, Lukin N, Parussulo ALA, Oliveira PV, Kyohara PK, Araki K, Toma HE. Unraveling the Mysterious Role of Palladium in Feigl bis(dimethylglyoximate)nickel(II) Spot Tests by Means of Confocal Raman Microscopy. Anal Chem 2012; 84:3067-9. [DOI: 10.1021/ac3003352] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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61
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Lalli PM, Iglesias BA, Deda DK, Toma HE, de Sa GF, Daroda RJ, Araki K, Eberlin MN. Resolution of isomeric multi-ruthenated porphyrins by travelling wave ion mobility mass spectrometry. RAPID COMMUNICATIONS IN MASS SPECTROMETRY : RCM 2012; 26:263-268. [PMID: 22223311 DOI: 10.1002/rcm.5314] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The ability of travelling wave ion mobility mass spectrometry (TWIM-MS) to resolve cationic meta/para and cis/trans isomers of mono-, di-, tri- and tetra-ruthenated supramolecular porphyrins was investigated. All meta isomers were found to be more compact than the para isomers and therefore mixtures of all isomeric pairs could be properly resolved with baseline or close to baseline peak-to-peak resolution (R(p-p)). Di-substituted cis/trans isomers were found, however, to present very similar drift times and could not be resolved. N(2) and CO(2) were tested as the drift gas, and similar α but considerably better values of R(p) and R(p-p) were always observed for CO(2).
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62
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de Paula LR, Parussulo AL, Araki K, Toma HE. Evaluation of Sun Protection Factor of Cosmetic Formulations by a Simple Visual In Vitro Method Mimicking the In Vivo Method. J Pharm Sci 2012; 101:726-32. [DOI: 10.1002/jps.22797] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/02/2011] [Accepted: 10/07/2011] [Indexed: 11/08/2022]
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63
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Gargalaka J, Couto RAA, Constantino VRL, Toma HE, Araki K. Influence of the relative amounts of crystalline and amorphous phases on the mechanical properties of polyamide-6 nanocomposites. J Appl Polym Sci 2012. [DOI: 10.1002/app.36509] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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64
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Mayer I, Nakamura K, Srinivasan A, Furuta H, Toma HE, Araki K. Spectroelectrochemical behavior of N-confused dioxohexaphyrins. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424605000927] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Doubly N -confused dioxohexaphyrins were characterized by cyclic voltammetry and spectroelectrochemistry in the -2.5 to +2.0 V vs Ag | Ag + (0.10 M, in CH3CN) range. Six reversible monoelectronic processes were found suggesting that the rich electrochemistry of porphyrin systems was preserved in that expanded macrocycle. However, the electronic and electrochemical properties of the free-base, Cu(II) and Ni(II) species were shown to be sensitive to the coordinated transition metal ions and solvent revealing a quite complex behavior, probably reflecting the higher flexibility and strong conformational effects on the energy levels and stability of those complexes.
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Engelmann FM, Losco P, Winnischofer H, Araki K, Toma HE. Synthesis, electrochemistry, spectroscopy and photophysical properties of a series of meso-phenylpyridylporphyrins with one to four pyridyl rings coordinated to [Ru(bipy)2Cl]+ groups. J PORPHYR PHTHALOCYA 2012. [DOI: 10.1142/s1088424602000063] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
A series of meso-phenylpyridylporphyrins and their respective supermolecular species obtained by the coordination of [ Ru ( bipy )2 Cl ]+ groups to the pyridyl substituents was synthesized and characterized. Their spectroscopic and electrochemical behavior were similar to that observed for the meso-tetra(4-pyridyl)porphyrin derivative, but the redox potential of the Ru (III/II) redox pair was about 70 mV more negative. The porphyrin centered fluorescence quantum yield exhibited a linear decrease as a function of the number of pyridyl substituents on the porphyrin ring. Efficient intramolecular energy transfer processes from the 3 MLCT state of the ruthenium complexes to the porphyrin center were observed at 77K in ethanol glass.
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66
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Santos JJ, Toma SH, Lalli PM, Riccio MF, Eberlin MN, Toma HE, Araki K. Exploring the coordination chemistry of isomerizable terpyridine derivatives for successful analyses of cis and trans isomers by travelling wave ion mobility mass spectrometry. Analyst 2012; 137:4045-51. [DOI: 10.1039/c2an35320b] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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67
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Toma HE. Profa. Dra. Judith Felcman - sua vida acadêmica e contribuição à ciência. QUIM NOVA 2012. [DOI: 10.1590/s0100-40422012000400039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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68
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Condomitti U, Zuin A, Silveira AT, Toma SH, Araki K, Toma HE. Superparamagnetic Carbon Electrodes: A Versatile Approach for Performing Magnetic Coupled Electrochemical Analysis of Mercury Ions. ELECTROANAL 2011. [DOI: 10.1002/elan.201100278] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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69
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Parussulo ALA, Huila MFG, Araki K, Toma HE. N3-dye-induced visible laser anatase-to-rutile phase transition on mesoporous TiO2 films. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2011; 27:9094-9099. [PMID: 21707061 DOI: 10.1021/la201838z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Titanium dioxide has been extensively used in photocatalysis and dye-sensitized solar cells, where control of the anatase-to-rutile phase transformation may allow the realization of more efficient devices exploiting the synergic effects at anatase/rutile interfaces. Thus, a systematic study showing the proof of concept of a dye-induced morphological transition and an anatase-to-rutile transition based on visible laser (532 nm) and nano/micro patterning of mesoporous anatase (Degussa P25 TiO(2)) films is described for the first time using a confocal Raman microscope. At low laser intensities, only the bleaching of the adsorbed N3 dye was observed. However, high enough temperatures to promote melting/densification processes and create a deep hole at the focus and an extensive phase transformation in the surrounding material were achieved using 1s laser pulses of 25-41 mW/cm(2), in resonance with the MLCT band. The dye was shown to play a key role, being responsible for the absorption and efficient conversion of the laser light into heat. As a matter of fact, the dye is photothermally decomposed to amorphous carbon or to gaseous species (CO(x), NO(x), and H(2)O) under a N(2) or O(2) atmosphere, respectively.
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70
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Rocha MA, Winnischofer H, Araki K, Anaissi FJ, Toma HE. A new insight on the preparation of stabilized alpha-nickel hydroxide nanoparticles. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2011; 11:3985-3996. [PMID: 21780396 DOI: 10.1166/jnn.2011.3872] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nickel hydroxide can provide an outstanding cathode material in alkaline secondary batteries, however the progressive decrease of the charge capacity as a function of the number of oxidation/reduction cycles is a challenging problem to be solved. New improvements on the electrochemical properties of electrode materials can be achieved by exploiting the much better performance of alpha-nickel hydroxide. Such materials were obtained in a stable form by sol-gel method and characterized by thermogravimetric analyses, UV-Vis spectroscopy, X-ray diffractometry, scanning and transmission electron microscopy, cyclic voltammetry and electrochemical quartz crystal microbalance techniques. The results revealed not only the formation of the alpha-Ni(OH)2 phase, but also a much better electrochemical reversibility and stability as compared with similar materials obtained by electrochemical precipitation method.
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71
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Bagatin IA, Araki K, Toma HE. Sensing hazardous metal ions using a fluoroionophore calix[4]arene species containing two 8-oxyquinoline groups. CAN J CHEM 2011. [DOI: 10.1139/v11-021] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The interaction of a calix[4]arene-based species containing two 8-oxyquinoline chromophore pendants with hazardous metal ions has been investigated using optical absorption and fluorimetric techniques. In the presence of Hg2+, Cd2+, and Pb2+ ions, there is only a small decrease of the calixarene absorption band at 283 nm. The main changes are associated with the absorption band of the 8-oxyquinoline group at 315 nm, undergoing a systematic bathochromic shift to above 350 nm. In addition, a systematic decrease of the oxyquinoline emission at λem = 392 nm (λexc = 315 nm) has been observed. These observations are consistent with the coordination of the metal ions to the quinoline groups attached to the calixarene ligand, providing a useful fluoroinophore species for analytical purposes.
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72
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Netto CGCM, Nakamatsu EH, Netto LES, Novak MA, Zuin A, Nakamura M, Araki K, Toma HE. Catalytic properties of thioredoxin immobilized on superparamagnetic nanoparticles. J Inorg Biochem 2011; 105:738-44. [PMID: 21470550 DOI: 10.1016/j.jinorgbio.2011.02.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2010] [Revised: 02/14/2011] [Accepted: 02/15/2011] [Indexed: 10/18/2022]
Abstract
Thioredoxin (Trx1), a very important protein for regulating intracellular redox reactions, was immobilized on iron oxide superparamagnetic nanoparticles previously coated with 3-aminopropyltriethoxysilane (APTS) via covalent coupling using the EDC (1-ethyl-3-{3-dimethylaminopropyl}carbodiimide) method. The system was extensively characterized by atomic force microscopy, vibrational and magnetic techniques. In addition, gold nanoparticles were also employed to probe the exposed groups in the immobilized enzyme based on the SERS (surface enhanced Raman scattering) effect, confirming the accessibility of the cysteines residues at the catalytic site. For the single coated superparamagnetic nanoparticle, by monitoring the enzyme activity with the Ellman reagent, DTNB=5,5'-dithio-bis(2-15 nitrobenzoic acid), an inhibitory effect was observed after the first catalytic cycle. The inhibiting effect disappeared after the application of an additional silicate coating before the APTS treatment, reflecting a possible influence of unprotected iron-oxide sites in the redox kinetics. In contrast, the doubly coated system exhibited a normal in-vitro kinetic activity, allowing a good enzyme recovery and recyclability.
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73
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Toma SH, Santos JJ, Araki K, Toma HE. Supramolecular Approach to Gold Nanoparticle/Triruthenium Cluster Hybrid Materials and Interfaces. Eur J Inorg Chem 2011. [DOI: 10.1002/ejic.201001118] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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74
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Nakamura M, Araki K, Toma HE. Probing magnetic and gold nanoparticles by using MAClevers® as ultrasensitive sensors. NANOSCALE 2010; 2:2583-2586. [PMID: 20981361 DOI: 10.1039/c0nr00533a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Magnetic AFM probes known as MAClevers® were employed for sensing picogram amounts of magnetic nanoparticles, based on the cantilever frequency shifts resulting from the magnetically induced adsorption of mass. By using organothiol functionalized magnetic nanoparticles, this analytical strategy was successfully extended to the detection of gold nanoparticles, as confirmed by confocal Raman microscopy.
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75
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Grasseschi D, Zamarion VM, Araki K, Toma HE. Surface Enhanced Raman Scattering Spot Tests: A New Insight on Feigl’s Analysis Using Gold Nanoparticles. Anal Chem 2010; 82:9146-9. [DOI: 10.1021/ac102238f] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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76
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Nikolaou S, Formiga ALB, Toma HE. Probing the electronic delocalization in a cyclic pyrazine ruthenium cluster hexamer. INORG CHEM COMMUN 2010. [DOI: 10.1016/j.inoche.2010.06.003] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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77
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Barros TC, Toma SH, Toma HE, Bastos EL, Baptista MS. Polymethine cyanine dyes in β-cyclodextrin solution: multiple equilibria and chemical oxidation. J PHYS ORG CHEM 2010. [DOI: 10.1002/poc.1692] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
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78
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Toma HE, Araki K, Formiga ALB, Alexiou ADP, Nunes GS. Electrocatalytic oxidation of methanol by the [Ru3O(OAc)6(py)2(CH3OH)]3+cluster: improving the metal-ligand electron transfer by accessing the higher oxidation states of a multicentered system. QUIM NOVA 2010. [DOI: 10.1590/s0100-40422010001000008] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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79
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Rebelo LP, Netto CGCM, Toma HE, Andrade LH. Enzymatic kinetic resolution of (RS)-1-(Phenyl)ethanols by Burkholderia cepacia lipase immobilized on magnetic nanoparticles. J BRAZIL CHEM SOC 2010. [DOI: 10.1590/s0103-50532010000800019] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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80
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Toma HE, Zamarion VM, Toma SH, Araki K. The coordination chemistry at gold nanoparticles. J BRAZIL CHEM SOC 2010. [DOI: 10.1590/s0103-50532010000700003] [Citation(s) in RCA: 79] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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81
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Parussulo ALA, Bonacin JA, Toma SH, Araki K, Toma HE. Unravelling the chemical morphology of a mesoporous titanium dioxide interface by confocal Raman microscopy: new clues for improving the efficiency of dye solar cells and photocatalysts. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2009; 25:11269-11271. [PMID: 19719164 DOI: 10.1021/la902551k] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
The presence of anatase and rutile domains on nanocrystalline films of P25 TiO2, as well as the distinct coordination modes of carboxylates on those phases, were revealed by confocal Raman microscopy, a technique that showed to be suitable for imaging the chemical morphology down to submicrometric size.
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Netto CG, Andrade LH, Toma HE. Enantioselective transesterification catalysis by Candida antarctica lipase immobilized on superparamagnetic nanoparticles. ACTA ACUST UNITED AC 2009. [DOI: 10.1016/j.tetasy.2009.08.022] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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83
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Deda DK, Uchoa AF, Caritá E, Baptista MS, Toma HE, Araki K. A new micro/nanoencapsulated porphyrin formulation for PDT treatment. Int J Pharm 2009; 376:76-83. [PMID: 19409465 DOI: 10.1016/j.ijpharm.2009.04.024] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2009] [Revised: 04/17/2009] [Accepted: 04/20/2009] [Indexed: 10/20/2022]
Abstract
The highly hydrophobic 5,10,15-triphenyl-20-(3-N-methylpyridinium-yl)porphyrin (3MMe) cationic species was synthesized, characterized and encapsulated in marine atelocollagen/xanthane gum microcapsules by the coacervation method. Further reduction in the capsule size, from several microns down to about 300-400 nm, was carried out successfully by ultrasonic processing in the presence of up to 1.6% Tween 20 surfactant, without affecting the distribution of 3MMe in the oily core. The resulting cream-like product exhibited enhanced photodynamic activity but negligible cytotoxicity towards HeLa cells. The polymeric micro/nanocapsule formulation was found to be about 4 times more phototoxic than the respective phosphatidylcholine lipidic emulsion, demonstrating high potentiality for photodynamic therapy applications.
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84
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Munoz RA, Toma SH, Toma HE, Araki K, Angnes L. Investigation of interfacial processes at tetraruthenated zinc porphyrin films using electrochemical surface plasmon resonance and electrochemical quartz crystal microbalance. Electrochim Acta 2009. [DOI: 10.1016/j.electacta.2008.12.020] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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85
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Toma HE, Araki K. Exploring the Supramolecular Coordination Chemistry-Based Approach for Nanotechnology. ACTA ACUST UNITED AC 2009. [DOI: 10.1002/9780470440124.ch5] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
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86
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Toma SH, Alexiou ADP, Toma HE, Araki K, Eberlin MN. Can mass dissociation patterns of transition-metal complexes be predicted from electrochemical data? JOURNAL OF MASS SPECTROMETRY : JMS 2009; 44:361-367. [PMID: 18942068 DOI: 10.1002/jms.1513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Cooks kinetic method has been very convenient to correlate the relative dissociation rates obtained by collision-induced fragmentation experiments with the energies of two related bonds in molecules and complexes in the gas phase. Reliable bond energy data are, however, not always available, particularly for polynuclear transition-metal complexes, such as the triruthenium acetate clusters of the general formula [Ru(3) (micro(3)-O)(micro-CH(3)COO)(6)(py)(2)(L)](+), where L = ring substituted N-heterocyclic ligands. Accordingly, their gas-phase collision-induced tandem mass spectrometry (CID MS/MS) dissociation patterns have been analyzed pursuing a relationship with the more easily accessible redox potentials (E(1/2)) and Lever's E(L) parameters. In fact, excellent linear correlations of ln(1/2A(L)/A(py)), where A(py) and A(L) are the abundance of the fragments retaining the pyridine (py) and L ligand, respectively, with E(1/2) and E(L) were found. This result shows that those electrochemical parameters are correlated with bond energies and can be used in the analysis of the dissociation data. Such modified Cooks method can be used, for example, to determine the electronic effects of substituents on the metal-ligand bonds for a series of transition-metal complexes.
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87
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Naue JA, Toma SH, Bonacin JA, Araki K, Toma HE. Probing the binding of tetraplatinum(pyridyl)porphyrin complexes to DNA by means of surface plasmon resonance. J Inorg Biochem 2009; 103:182-9. [DOI: 10.1016/j.jinorgbio.2008.10.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2008] [Revised: 09/26/2008] [Accepted: 10/06/2008] [Indexed: 10/21/2022]
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88
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Matsumoto MY, Toyama MM, Mayer I, Winnischofer H, Araki K, Toma HE. Electronic conduction and electrocatalysis by supramolecular tetraruthenated copper porphyrazine films. J BRAZIL CHEM SOC 2009. [DOI: 10.1590/s0103-50532009000400016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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89
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Bonacin JA, Engelmann FM, Severino D, Toma HE, Baptista MS. Singlet oxygen quantum yields (Φd) in water using beetroot extract and an array of LEDs. J BRAZIL CHEM SOC 2009. [DOI: 10.1590/s0103-50532009000100006] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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90
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Souza VR, Rechenberg HR, Bonacin JA, Toma HE. Spectroscopic and electrochemical properties of iron(II) complexes of polydentate Schiff bases containing pyrazine, pyridine and imidazole groups. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2008; 71:1296-1301. [PMID: 18511338 DOI: 10.1016/j.saa.2008.04.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/23/2007] [Revised: 04/01/2008] [Accepted: 04/10/2008] [Indexed: 05/26/2023]
Abstract
We report the synthesis and spectroscopic/electrochemical properties of iron(II) complexes of polydentate Schiff bases generated from 2-acetylpyridine and 1,3-diaminopropane, acetylpyrazine and 1,3-diaminopropane, and from 2-acetylpyridine and L-histidine. The complexes exhibit bis(diimine)-iron(II) chromophores in association with pyrazine, pyridine or imidazole groups displaying contrasting pi-acceptor properties. In spite of their open geometry, their properties are much closer to those of macrocyclic tetraimineiron(II) complexes. An electrochemical/spectroscopic correlation between E degrees (FeIII/II) and the energies of the lowest MLCT band has been observed, reflecting the stabilization of the HOMO levels as a consequence of the increasing backbonding effects in the series of compounds. Mössbauer data have also confirmed the similarities in their electronic structure, as deduced from the spectroscopic and theoretical data.
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91
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Nunes GS, Alexiou AD, Toma HE. Catalytic oxidation of hydrocarbons by trinuclear μ-oxo-bridged ruthenium-acetate clusters: Radical versus non-radical mechanisms. J Catal 2008. [DOI: 10.1016/j.jcat.2008.10.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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92
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Nikolaou S, Tomazela DM, Eberlin MN, Toma HE. Synthesis and characterization of the [Ru3O(CH3COO)6(py)2(BPE)Ru(bpy)2Cl](PF6)2 dimer. TRANSIT METAL CHEM 2008. [DOI: 10.1007/s11243-008-9156-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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93
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Nikolaou S, Toma HE. A Convergent Approach for the Generation of Dendrimers Containing the [Ru3O(CH3COO)6] Electroactive Core. Eur J Inorg Chem 2008. [DOI: 10.1002/ejic.200800079] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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94
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Zamarion VM, Timm RA, Araki K, Toma HE. Ultrasensitive SERS Nanoprobes for Hazardous Metal Ions Based on Trimercaptotriazine-Modified Gold Nanoparticles. Inorg Chem 2008; 47:2934-6. [DOI: 10.1021/ic800122v] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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95
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Ravanat JL, Cadet J, Araki K, Toma HE, Medeiros MHG, Mascio PD. Supramolecular Cationic Tetraruthenated Porphyrin and Light-Induced Decomposition of 2-Deoxyguanosine Predominantly Via a Singlet Oxygen-Mediated Mechanism. Photochem Photobiol 2008. [DOI: 10.1111/j.1751-1097.1998.tb02532.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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96
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Bonifacio LS, Gordijo CR, Constantino VRL, Silva DO, Kiyohara PK, Araki K, Toma HE. Optical changes and writing on hydrotalcite supported gold nanoparticles. JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY 2008; 8:274-279. [PMID: 18468071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Gold nanoparticles (AuNP) incorporated into hydrotalcite (HT), provide an interesting type of pigment in which temperature can modulate the plasmon resonance and the aggregation phenomenon. As inferred from microscopy techniques, the preferential binding sites are located at the border of the HT external basal surface, leading to aggregates of gold nanoparticles displaying characteristic plasmon resonance and interference bands around 520 and 700 nm, respectively. The thermally induced color changes in the HT-supported gold material arise from the competition between of nanoparticles aggregation and fusion processes, as characterized by TEM and STM. A laser beam can also induce such changes, allowing the writing of optical information on this type of material.
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97
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Toma SH, Bonacin JA, Araki K, Toma HE. Controlled Stabilization and Flocculation of Gold Nanoparticles by Means of 2-Pyrazin-2-ylethanethiol and Pentacyanidoferrate(II) Complexes. Eur J Inorg Chem 2007. [DOI: 10.1002/ejic.200700151] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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98
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Engelmann FM, Mayer I, Gabrielli DS, Toma HE, Kowaltowski AJ, Araki K, Baptista MS. Interaction of cationic meso-porphyrins with liposomes, mitochondria and erythrocytes. J Bioenerg Biomembr 2007; 39:175-85. [PMID: 17436065 DOI: 10.1007/s10863-007-9075-0] [Citation(s) in RCA: 83] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2006] [Accepted: 12/18/2006] [Indexed: 02/08/2023]
Abstract
Two series of cationic porphyrins meso-(3N-methylpyridinium)phenylporphyrin (3P1, 3P2c, 3P2t, 3P3 and 3P4) and meso-(4N-methylpyridinium)phenylporphyrin (4P1, 4P2c, 4P2t, 4P3 and 4P4) were studied to obtain a comprehensive understanding of factors that influence the binding of cationic porphyrins to liposomes and mitochondria, as well as their photodynamic efficiencies in erythrocytes. Binding and photodynamic efficiency were found to be inversely proportional to the number of positively charged groups and directly proportional to n-octanol/water partition coefficients (log P(OW)), except for the cis molecules 3P2c and 4P2c. In the cis molecules, binding and photodynamic efficiency were much higher than expected, indicating that specific interactions not accounted by log P(OW) enhance photodynamic efficiency. The effect of mitochondrial transmembrane electrochemical potentials on cationic porphyrin binding constants was estimated to be as large as 15%, and may be useful to selectively target this organelle when promoting photodynamic therapy to induce apoptosis.
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99
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Antunes A, Gozzo FV, Nakamura M, Safatle AMV, Morelhão SL, Toma HE, Barros PSM. Analysis of the healthy rabbit lens surface using MAC Mode atomic force microscopy. Micron 2007; 38:286-90. [PMID: 16797183 DOI: 10.1016/j.micron.2006.04.006] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2005] [Revised: 04/14/2006] [Accepted: 04/15/2006] [Indexed: 10/24/2022]
Abstract
In this investigation healthy rabbit crystalline lenses were characterized by atomic force microscopy (AFM). The lenses were cut in slices with thickness with 1mm and thus, put after cortex distinct regions of nucleus and cortex for AFM examination. AFM analysis were carried out using a PicoSPM I operating in Mac Mode. We obtained topographic images of rabbit lenses and a quantitative analysis of the width and height of fibers for nucleus and cortex regions. The longitudinal section analysis of fibers in the nucleus region indicated structures with an average width of 200nm and average height of 200nm. The intershells distance was determined as 4microm. Fiber cell cross-section dimensions, longitudinal and transverse widths, could be estimated in these regions from the AFM images. Structures with average widths as small as 1.0microm are observed in the nucleus; the intershell distance is 4.0microm. In cortical regions, hexagonal structures with average longitudinal and transverse widths of 5.0mum and 3.0mum, respectively, were identified. Three-dimensional images of tissue sections with resolution on a nanometer scale were obtained. The potential of AFM analysis for characterizing healthy and pathologic lens tissues is discussed.
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100
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Toma SH, Toma HE. Self assembled rotaxane and pseudo-rotaxanes based on beta-cyclodextrin inclusion compounds with trans-1,4-bis[(4-pyridyl)ethenyl]benzene-pentacyanoferrate(II) complexes. J BRAZIL CHEM SOC 2007. [DOI: 10.1590/s0103-50532007000200006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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