Search results for "Nitrobenzene"
showing 10 items of 126 documents
N-Succinyl-chitosan systems for 5-aminosalicylic acid colon delivery: In vivo study with TNBS-induced colitis model in rats
2011
5-Aminosalicylic acid (5-ASA) loaded N-Succinyl-chitosan (SucCH) microparticle and freeze-dried system were prepared as potential delivery systems to the colon. Physicochemical characterization and in vitro release and swelling studies were previously assessed and showed that the two formulations appeared to be good candidates to deliver the drug to the colon. In this work the effectiveness of these two systems in the treatment of inflammatory bowel disease was evaluated. In vitro mucoadhesive studies showed excellent mucoadhesive properties of both the systems to the inflamed colonic mucosa. Experimental colitis was induced by rectal instillation of 2,4,6-trinitrobenzene sulfonic acid (TNB…
Protection against 2,4,6-trinitrobenzenesulphonic acid-induced colonic inflammation in mice by the marine products bolinaquinone and petrosaspongioli…
2005
Proinflammatory mediators, namely eicosanoids, reactive oxygen and nitrogen species and cytokines, are clearly involved in the pathogenesis of intestinal bowel disease. bolinaquinone (BQ) and petrosaspongiolide M (PT), two marine products with potent anti-inflammatory action, have been shown to control the production of mediators in acute and chronic inflammatory processes. Hence, we have tested here the hypothesis that BQ and PT could ameliorate inflammation and oxidative stress parameters in 2,4,6-trinitrobenzenesulphonic acid (TNBS)-induced colitis in Balb/c mice. BQ and PT were given orally in doses of 10 or 20mg/kg/day. Treatment of the animals with BQ or PT at the highest dose signifi…
How important is roaming in the photodegradation of nitrobenzene?
2020
At low excitation energies nitrobenzene photoreleases NO with low translational and rotational energy, while at higher excitation energies NO is photoreleased with both low and high translational and rotational energy. The fast products are formed through a singlet-triplet crossing (STC) region featuring an oxaziridine ring, while a ground state roaming mechanism was suggested to produce the slow molecules. Computing translational and rotational energies performing CASSCF classical dynamics, we here prove how the same oxaziridine STC can account for both fast and slow photoproducts, depending on the region of the seam through which the ground state is populated. A roaming-type STC/CI has al…
Computational flow dynamics in a geometric model of intussusceptive angiogenesis.
2009
Intussusceptive angiogenesis is a process that forms new blood vessels by the intraluminal division of a single blood vessel into two lumens. Referred to as nonsprouting or intussusceptive angiogenesis, this angiogenic process has been described in morphogenesis and chronic inflammation. Mechanical forces are relevant to the structural changes associated with intussusceptive angiogenesis because of the growing evidence that physiologic forces influence gene transcription. To provide a detailed analysis of the spatial distribution of physiologic shear stresses, we developed a 3D finite element model of the intraluminal intussusceptive pillar. Based on geometries observed in adult intussuscep…
MOF-Mediated Synthesis of Supported Fe-Doped Pd Nanoparticles under Mild Conditions for Magnetically Recoverable Catalysis**
2020
Metal–organic framework (MOF)-driven synthesis is considered as a promising alternative for the development of new catalytic materials with well-designed active sites. This synthetic approach is used here to gradually transform a new bimetallic MOF, with Pd and Fe as the metal components, by the in situ generation of aniline under mild conditions. This methodology results in a compositionally homogeneous nanocomposite formed by Fe-doped Pd nanoparticles that, in turn, are supported on iron oxide-doped carbon. The nanocomposite has been fully characterized by several techniques such as IR and Raman spectroscopy, TEM, XPS, and XAS. The performance of this nanocomposite as an heterogeneous cat…
Wavelength-Selective Softening of Hydrogel Networks.
2021
Photoresponsive hydrogels hold key potential in advanced biomedical applications including tissue engineering, regenerative medicine, and drug delivery, as well as intricately engineered functions such as biosensing, soft robotics, and bioelectronics. Herein, the wavelength-dependent degradation of bio-orthogonal poly(ethylene glycol) hydrogels is reported, using three selective activation levels. Specifically, three chromophores are exploited, that is, ortho-nitrobenzene, dimethyl aminobenzene, and bimane, each absorbing light at different wavelengths. By examining their photochemical action plots, the wavelength-dependent reactivity of the photocleavable moieties is determined. The wavele…
Pickering Emulsions of Fluorinated TiO2: A New Route for Intensification of Photocatalytic Degradation of Nitrobenzene
2020
International audience; Fluorination of the TiO2 surface has been often reported as a tool to increase the photocatalytic efficiency due to the beneficial effects in terms of production of oxidizing radicals. Moreover, it is shown that the unique amphiphilic properties of the fluorinated TiO2 (TiO2-F) surface allow one to use this material as a stabilizer for the formulation of Pickering emulsions of poorly soluble pollutants such as nitrobenzene (NB) in water. The emulsions have been characterized in terms of size of the droplets, type of emulsion, possibility of phase inversion, contact angle measurements, and optical microscopy. The emulsified system presents micrometer-sized droplets of…
Pyrazolo[3,4-d]pyrimidine derivatives as COX-2 selective inhibitors: synthesis and molecular modelling studies.
2009
The pyrazolo[3,4-d]pyrimidine system shows a multitude of interesting pharmacological properties. Owing to the potential anti-inflammatory activity of 5-benzamido-pyrazolo[3,4-d]pyrimidin- 4-one derivatives and considering the easy synthesis of this class of compounds, a set of new 5- benzamido-1H-pyrazolo[3,4-d]pyrimidin-4-ones has been prepared in 42-80% yields by reacting 5- aminopyrazole-4(N-benzoyl)carbohydrazide derivatives and the opportune triethylorthoesters. Compounds 8a, b, 10a–d, and 11a, b revealed a superior inhibitory profile against COX-2, when compared to that of reference standards NS398 and indomethacin. Molecular modelling studies confirmed the obtained biological result…
Pyrene-functionalized nanoparticles: two independent sensors, the excimer and the monomer.
2012
The high surface-to-volume ratio of nanoparticles has been used to obtain a high local concentration of pyrene units on their periphery, making the formation of both pyrene emissive species possible using amazingly small pyrene concentrations. The sensing properties of model pyrene-functionalized nanoparticles was investigated by using different nitroaromatic compounds [m-nitroaniline and p-nitroaniline] and nitrobenzenes [nitrobenzene, p-nitrotoluene, 2,4-dinitrotoluene, and 2,6-dinitrotoluene]. The hybrid system acts as a dual-fluorescence sensor, in which the decrease of the pyrene emission, induced by the quencher, is hardly reflected in the pyrene excimer emission. The encapsulation ca…