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51.
52.
Correlation Between Autofluorescence Intensity and Tumor Area in Mice Bearing Renal Cell Carcinoma 总被引:3,自引:2,他引:1
Bellini MH Coutinho EL Courrol LC Rodrigues de Oliveira Silva F Vieira Júnior ND Schor N 《Journal of fluorescence》2008,18(6):1163-1168
Protoporphyrin IX (PpIX) is a porphyrin derivative that is accumulated in cancerous tissue in consequence of the tumor-specific
metabolic alterations. The aim of this study was to evaluate the accumulation of PpIX in mice bearing renal cell carcinoma
by spectroscopy analysis. A total of 24 male Balb/c mice, 6 weeks old, were divided into six groups: Normal (without inoculation
of tumor cells) and 4, 8, 13, 16, and 20 days after inoculation of tumor cells. The orthotopic tumor model of renal cancer
was used. Murine renal cell carcinoma (Renca cells) were inoculated into the subcapsular space of the kidney. Normal and tumor-bearing
kidneys in different progression stages were removed and analyzed by ex-vivo spectroscopy and by microscopy, for tumor histometric
analysis. Emission spectra were obtained by exciting the samples at 405 nm. Significant differences between normal and tumor-bearing
kidneys in autofluorescence shape occurred in the 600–700 nm spectral region. A good correlation was found between emission
band intensity at 635 nm and the tumor area. 相似文献
53.
Fatma Chaari Lilia Belghith-Fendri Soumaya Zaouri-Ellouzi Dorra Driss Monia Blibech Fatma Kallel 《Natural product research》2016,30(12):1353-1359
The aim of this study was first to ascertain the chemical composition and the physicochemical properties of cereal extracted β-glucan from barley flour. Secondly, to assess the antioxidant properties and the antibacterial properties of extracted β-glucan hydrolysates. The proximate composition, FT-IR and scanning electron microscopy of extracted β-Glucan were studied. Hydrolysates from extracted β-glucan, obtained by lichenase EGL from Penicillium occitanis, were a mixed linkage beta-oligosaccharides (MLBO) of trisaccharides and tetrasaccharides. MLBO showed a DPPH radical scavenger with IC50 about 1.8 ± 0.01 mg/mL whereas the IC50 of extracted β-glucan was about 5 ± 0.01 mg/mL. MLBO showed a high antioxidative capacity (175 μmol/mL α-tocopherol equivalents) at 5 mg/mL. The antimicrobial activity was confirmed against all tested bacteria especially at 20 mg/mL of MLBO while no inhibition was observed for all the strains used after the addition of either EGL or extracted β-glucan. 相似文献
54.
Versatile low-molecular-weight hydrogelators: achieving multiresponsiveness through a modular design
Milanesi L Hunter CA Tzokova N Waltho JP Tomas S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2011,17(35):9753-9761
Multiresponsive low-molecular-weight hydrogelators (LMWHs) are ideal candidates for the development of smart, soft, nanotechnology materials. The synthesis is however very challenging. On the one hand, de novo design is hampered by our limited ability to predict the assembly of small molecules in water. On the other hand, modification of pre-existing LMWHs is limited by the number of different stimuli-sensitive chemical moieties that can be introduced into a small molecule without seriously disrupting the ability to gelate water. Herein we report the synthesis and characterization of multistimuli LMWHs, based on a modular design, composed of a hydrophobic, disulfide, aromatic moiety, a maleimide linker, and a hydrophilic section based on an amino acid, here N-acetyl-L-cysteine (NAC). As most LMWHs, these gelators experience reversible gel-to-sol transition following temperature changes. Additionally, the NAC moiety allows reversible control of the assembly of the gel by pH changes. The reduction of the aromatic disulfide triggers a gel-to-sol transition that, depending on the design of the particular LMWH, can be reverted by reoxidation of the resulting thiol. Finally, the hydrolysis of the cyclic imide moieties provides an additional trigger for the gel-to-sol transition with a timescale that is appropriate for use in drug-delivery applications. The efficient response to the multiple external stimuli, coupled to the modular design makes these LMWHs an excellent starting point for the development of smart nanomaterials with applications that include controlled drug release. These hydrogelators, which were discovered by serendipity rather than design, suggest nonetheless a general strategy for the introduction of multiple stimuli-sensitive chemical moieties, to offset the introduction of hydrophilic moieties with additional hydrophobic ones, in order to minimize the upsetting of the critical hydrophobic-hydrophilic balance of the LMWH. 相似文献
55.
We report a novel Nb(V)−carboxylate cluster obtained from reaction of niobium(V) ethoxide and pivalic (trimethylacetic) acid. Single crystal X-ray diffraction data reveal a structure composed of 16 Nb(V) ions featuring oxo-, ethoxy- and pivalate moieties. The new cluster exhibits the highest nuclearity among structurally characterized niobium carboxylates reported to date. 相似文献
56.
Guettari Moez Ajroudi Lilia Jouini Karima Tajouri Tahar Herráez José V. 《Journal of solution chemistry》2014,43(8):1414-1420
Journal of Solution Chemistry - The aim of this work is to develop a simple theory to study the effect of the addition of an impurity on the interaction between unlike molecules in mixed liquids.... 相似文献
57.
Gies P Roy C Javorniczky J Henderson S Lemus-Deschamps L Driscoll C 《Photochemistry and photobiology》2004,79(1):32-39
The 2002 revision of the UV index (UVI) issued by the World Health Organisation (WHO), the World Meteorological Office (WMO), the United Nations Environment Programme (UNEP) and the International Commission on Non-Ionizing Radiation Protection (ICNIRP) (World Health Organization [2002] Global Solar UV Index: A Practical Guide. WHO, Geneva) was motivated by the need to further standardize the use and presentation of the UVI. Awareness of the hazards of solar UV radiation (UVR) is generally high in Australia, but more effective use of the UVI will assist in promoting further changes to the population's sun exposure behavior. UVI levels for a number of cities around Australia as measured by the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), covering the time period 1996-2000, are presented. Also shown are UVI forecasts from the Australian Bureau of Meteorology (BOM). Agreement between the BOM data and the measurements varies depending on the location but is within 2 UVI units approximately 75% of the time. UVI levels are supplied to the media, and in summer values in excess of 12-14 are regularly recorded, although the more northerly locations occasionally reach 16 and 17. The factors affecting the solar UVR environment and the measured UVI are also discussed and compared against measurements from the UK. 相似文献
58.
The reaction is investigated between sodium-metallated (NaNH2) phenylacetic acid dialkyl amides and methyl cinnamate or cinnamic acid dialkyl amides. The thermodynamic equilibrium between the diastereomeric 2,3-diphenylglutaric acid amidoesters or diamides is 5/95 in favour of thethreo-isomer. Under kinetic conditions the stereochemistry of the reaction depends on the nature of the donor and the solvent.
Michael Reaktion. V. Stereochemie der durch NaNH2 katalysierten zweistufigen Reaktion zwischen Dialkylamiden der Phenylessigsäure und Methylestern oder Dialkylamiden der Zimtsäure
Zusammenfassung Die Umsetzung zwischen der mit festem NaNH2 gewonnenen Natriumderivaten der Dialkylamiden der Phenylessigsäure und Methylestern oder Dialkylamiden der Zimtsäure wurde untersucht. Das thermodynamischeE/T-Verhältnis zwischen den gewonnenen diastereomeren Amidestern und Diamiden der 2,3-Diphenylglutarsäure beträgt in allen Fällen 5/95. Das stereochemische Ergebnis unter kinetischen Bedingungen hängt von der Natur des Donators und von den Lösungsmitteln ab.相似文献
59.
Lilia Sghaier Christophe B. Y. Cordella Douglas N. Rutledge Mickaël Watiez Sylvie Breton Patrick Sassiat Didier Thiebaut Jrme Vial 《Journal of separation science》2016,39(9):1675-1683
Due to lipid oxidation, off‐flavors, characterized by a fishy odor, are emitted during the heating of rapeseed oil in a fryer and affect the flavor of rapeseed oil even at low concentrations. Thus, there is a need for analytical methods to identify and quantify these products. To study the headspace composition of degraded rapeseed oil, and more specifically the compounds responsible for the fishy odor, a headspace trap gas chromatography with mass spectrometry method was developed and validated. Six volatile compounds formed during the degradation of rapeseed oil were quantified: 1‐penten‐3‐one, (Z)‐4‐heptenal, hexanal, nonanal, (E,E)‐heptadienal, and (E)‐2‐heptenal. Validation using accuracy profiles allowed us to determine the valid ranges of concentrations for each compound, with acceptance limits of 40% and tolerance limits of 80%. This method was then successfully applied to real samples of degraded oils. 相似文献
60.
Gorokhovsky Alexander Saunina Svetlana Maximova Lilia Tretyachenko Elena Goffman Vladimir Escalante-Garcia José Iván Vikulova María 《Research on Chemical Intermediates》2022,48(3):1227-1248
Research on Chemical Intermediates - Potassium polytitanates powders were modified by treatment in aqueous solutions of manganese sulfate at different pH, the obtained intermediates (PPT/Mn) were... 相似文献