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1.
In vivo near-infrared Raman spectroscopy: demonstration of feasibility during clinical gastrointestinal endoscopy 总被引:7,自引:0,他引:7
Raman spectroscopy (RS) has potential for disease classification within the gastrointestinal tract (GI). A near-infrared (NIR) fiber-optic RS system has been developed previously. This study reports the first in vivo Raman spectra of human gastrointestinal tissues measured during routine clinical endoscopy. This was achieved by using this system with a fiber-optic probe that was passed through the endoscope instrument channel and placed in contact with the tissue surface. Spectra could be obtained with good signal-to-noise ratio in 5 s. The effects on the spectra of varying the pressure of the probe tip on the tissue and of the probe-tissue angle were determined and shown to be insignificant. The limited set of spectra from normal and diseased tissues revealed only subtle differences. Therefore, powerful spectral-sorting algorithms, successfully implemented in prior ex vivo studies, are required to realize the full diagnostic potential of RS for tissue classification in the GI. 相似文献
2.
Cini R Tamasi G Defazio S Corsini M Zanello P Messori L Marcon G Piccioli F Orioli P 《Inorganic chemistry》2003,42(24):8038-8052
The reaction of trans-[RuCl(2)(PPh(3))(3)] (Ph = C(6)H(5)) with 2-thio-1,3-pyrimidine (HTPYM) and 6-thiopurines (TPs) produced mainly crystalline solids that consist of cis,cis,trans-[Ru(PPh(3))(2)(N,S-TPYM)(2)] (1) and cis,cis,trans-[Ru(PPh(3))(2)(N(7),S-TPs)(2)]X(2) (X = Cl(-), CF(3)SO(3)(-)). In the case of TPs, other coordination isomers have never been isolated and reported. Instead, the mother liquor obtained after filtration of 1 produced red single crystals of trans,cis,cis-[Ru(PPh(3))(2)(N,S-TPYM)(2)].2H(3)O(+).2Cl(-) (2.2H(3)O(+).2Cl(-)). Selected ruthenium(II)-thiobase complexes were studied for their structural, reactivity, spectroscopic, redox, and cytotoxic properties. Single crystals of 1 contain thiopyrimidinato anions chelated to the metal center via N and S. The Ru[bond]N bonds are significantly elongated for 1 [2.122(2) and 2.167(2) A] with respect to 2 [2.063(3) A] because of the trans influence from PPh(3). The coordination pseudo-octahedron for 2 is significantly elongated at the apical sites (PPh(3) ligands). Solutions of cis,cis,trans isomers in air are stable for weeks, whereas those of 2 turn green within 24 h, in agreement with the respective redox potentials. cis,cis,trans- and trans,cis,cis-[Ru(PH(3))(2)(N,S-TPYM)(2)], as optimized through the DFT methods at the Becke3LYP level are in good agreement with experimental geometrical parameters (1 and 2), with cis,cis,trans being more stable than trans,cis,cis by 3.88 kcal. The trend is confirmed by molecular modeling based on semiempirical (ZINDO/1) and molecular mechanics (MM) methods. Cytotoxic activity measurements for cis,cis,trans-[Ru(PPh(3))(N-THZ)(N(7),S -H(2)TP)(2)]Cl(2) (4) (THZ = thiazole, H(2)TP = 6-thiopurine) and cis,cis,trans-[Ru(PPh(3))(2)(N(7),S-HTPR)2]Cl(2) (5) (HTPR = 6-thiopurine riboside) against ovarian cancer cells A2780/S gave IC(50) values of 17 +/- 1 and 29 +/- 9 microM, respectively. Furthermore, the spectral analysis of HTPYM, TPs, and their Ru(II) complexes in solution shows that intense absorptions occur in the UVA/vis region of light, whereas standard nucleobases absorb in the UVB region. 相似文献
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Dr. Viktor Pfeifer Marie Certiat Dr. Donia Bouzouita Dr. Alberto Palazzolo Sébastien Garcia-Argote Elodie Marcon David-Alexandre Buisson Dr. Philippe Lesot Prof. Laurent Maron Dr. Bruno Chaudret Dr. Simon Tricard Dr. Iker del Rosal Prof. Romuald Poteau Dr. Sophie Feuillastre Dr. Grégory Pieters 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(22):4988-4996
Ruthenium nanocatalysis can provide effective deuteration and tritiation of oxazole, imidazole, triazole and carbazole substructures in complex molecules using D2 or T2 gas as isotopic sources. Depending on the substructure considered, this approach does not only represent a significant step forward in practice, with notably higher isotope uptakes, a broader substrate scope and a higher solvent applicability compared to existing procedures, but also the unique way to label important heterocycles using hydrogen isotope exchange. In terms of applications, the high incorporation of deuterium atoms, allows the synthesis of internal standards for LC-MS quantification. Moreover, the efficacy of the catalyst permits, even under subatmospheric pressure of T2 gas, the preparation of complex radiolabeled drugs owning high molar activities. From a fundamental point of view, a detailed DFT-based mechanistic study identifying undisclosed key intermediates, allowed a deeper understanding of C−H (and N−H) activation processes occurring at the surface of metallic nanoclusters. 相似文献
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Yang VX Munce N Pekar J Gordon ML Lo S Marcon NE Wilson BC Vitkin IA 《Optics letters》2004,29(15):1754-1756
High-resolution optical coherence tomography demands a large detector bandwidth and a high numerical aperture for real-time imaging, which is difficult to achieve over a large imaging depth. To resolve these conflicting requirements we propose a novel multifocus fiber-based optical coherence tomography system with a micromachined array tip. We demonstrate the fabrication of a prototype four-channel tip that maintains a 9-14-microm spot diameter with more than 500 microm of imaging depth. Images of a resolution target and a human tooth were obtained with this tip by use of a four-channel cascaded Michelson fiber-optic interferometer, scanned simultaneously at 8 kHz with geometric power distribution across the four channels. 相似文献
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Richard P. Brinn Jaydione Marcon Marcos Tavares-Dias Ira M. Brinn 《Photochemistry and photobiology》2009,85(1):358-364
The fluorescence spectra of the tropical fish, Cardinal Tetra ( Paracheirodon axelrodi ), originating in the Amazon region of Brazil, were determined. These spectra were then treated using factor analysis, generating two contributing spectra and separating out the noise. Time-resolved fluorescence results indicated that the fluorescent system in the epidermis undergoes excited state reaction. Excited state proton transfer is suggested as being present. Both intentionally stressed and nonstressed individuals were used and some small differences were noted in the contributions of the two calculated contributing spectra to the experimental spectra, presumably as a function of stress. The results are compared with those obtained by the standard determination of cortisol level using the whole body extraction method and it is suggested that the method could be tested as an improved, nondestructive way to determine stress in this species, which is a necessary step in the development of "best management practices" of methods for storage and transport of the fish. 相似文献
8.
Barbara Perez Gonçalves Silva Rodrigo Oliveira Marcon Sergio Brochsztain 《Journal of inclusion phenomena and macrocyclic chemistry》2010,68(3-4):313-322
Fluorescence spectroscopy was used to characterize inclusion compounds between 4-amino-1,8-naphthalimides (ANI) derivatives and different cyclodextrins (CDs). The ANI derivatives employed were N-(12-aminododecyl)-4-amino-1,8-naphthalimide (mono-C12ANI) and N,N′-(1,12-dodecanediyl)bis-4-amino-1,8-naphthalimide (bis-C12ANI). The CDs used here were α-CD, β-CD, γ-CD, HP-α-CD, HP-β-CD and HP-γ-CD. The presence of CDs resulted in pronounced blue-shifts in the emission spectra of the ANI derivatives, with increases in emission intensity. This behavior was parallel to that observed for the dyes in apolar solvents, indicating that inclusion complexes were formed between the ANI and the CDs. Mono-C12ANI formed inclusion complexes of 1:1 stoichiometry with all the CDs studied. Complexes with the larger CDs (HP-β-CD, HP-γ-CD and γ-CD) were formed by inclusion of the chromophoric ANI ring system, whereas the smaller CDs (α-CD, HP-α-CD and β-CD) formed complexes with mono-C12ANI by inclusion of the dodecyl chain. Bis-C12ANI formed inclusion complexes of 1:2 stoichiometry with HP-β-CD, HP-γ-CD and γ-CD, but did not form inclusion complexes with α-CD, HP-α-CD and β-CD. The data were treated in the case of the large CDs using a Benesi-Hildebrand like equation, giving the following equilibrium constants: mono-C12ANI:HP-β-CD (K 11 = 50 M?1), mono-C12ANI:HP-γ-CD (K 11 = 180 M?1), bis-C12ANI:HP-β-CD (K 12 = 146 M?2), bis-C12ANI:HP-γ-CD (K 12 = 280 M?2). 相似文献
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Determination of the geographical origin of Brazilian wines by isotope and mineral analysis 总被引:1,自引:0,他引:1
Dutra SV Adami L Marcon AR Carnieli GJ Roani CA Spinelli FR Leonardelli S Ducatti C Moreira MZ Vanderlinde R 《Analytical and bioanalytical chemistry》2011,401(5):1575-1580
In the present research, we studied wines from three different south Brazilian winemaking regions with the purpose of differentiating
them by geographical origin of the grapes. Brazil's wide territory and climate diversity allow grape cultivation and winemaking
in many regions of different and unique characteristics. The wine grape cultivation for winemaking concentrates in the South
Region, mainly in the Serra Gaúcha, the mountain area of the state of Rio Grande do Sul, which is responsible for 90% of the
domestic wine production. However, in recent years, two new production regions have developed: the Campanha, the plains to
the south and the Serra do Sudeste, the hills to the southeast of the state. Analysis of isotopic ratios of 18O/16O of wine water, 13C/12C of ethanol, and of minerals were used to characterize wines from different regions. The isotope analysis of δ18O of wine water and minerals Mg and Rb were the most efficient to differentiate the regions. By using isotope and mineral
analysis, and discrimination analysis, it was possible to classify the wines from south Brazil. 相似文献
10.
Modulation of the quantum electromagnetic excitations in bismuth is reported. The effect is shown as peculiar of these excitations and an explanation in terms of a previous theory is given. 相似文献