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1.
Eur Rev Med Pharmacol Sci ; 27(23): 11383-11401, 2023 Dec.
Article in English | MEDLINE | ID: mdl-38095387

ABSTRACT

OBJECTIVE: The aim of this study was to assess and compare the therapeutic effects of allogenic and xenogeneic bone marrow-derived mesenchymal stem cells (BM-MSCs) on a rat model for treating experimental lung inflammation, oxidative stress, and apoptosis. MATERIALS AND METHODS: Male Wistar rats were randomly divided into four groups. Group 1 received an intraperitoneal injection of olive oil vehicle (2 mL/kg body weight) for 8 weeks. Group 2 received an intraperitoneal injection of carbon tetrachloride (CCl4) (0.5 mL/kg body weight, twice/week) dissolved in olive oil for 8 weeks. Groups 3 and 4 received the CCl4 similar to group 2, followed by the intravenous injection of rat and mouse BM-MSCs (1 × 106 cells/rat twice/week into a lateral tail vein), respectively, for 4 weeks. Subsequently, the rats were sacrificed, and lung tissues were excised for molecular, histological, and ultrastructural investigations. RESULTS: Fibrosis, interstitial bleeding, dilatation and congestion of blood vessels, intra-alveolar edema, damaged alveoli, scattered mononuclear leucocytic infiltrates, and an increased number of apoptotic cells and apoptotic remnants were observed in the lungs of rats exposed to CCl4; the treatment with rat and mouse BM-MSCs attenuated these changes. The effects of CCl4 on the increase in collagen fibers in the lungs and the expression levels of cyclooxygenase-2, tumor necrosis factor-α, and apoptotic protein p53 were considerably reduced following treatment with the BM-MSCs. The higher levels of lipid peroxidation, the lower-level glutathione content, and the activities of superoxide dismutase, glutathione peroxidase, and glutathione-S-transferase in CCl4-injected rats were significantly improved by treatments with rat and mouse BM-MSCs. CONCLUSIONS: These findings indicate that mouse and rat BM-MSCs, which were more potent, can protect against CCl4-induced lung damage and fibrosis by reducing inflammation, apoptosis, and oxidative stress and boosting the antioxidant defense system.


Subject(s)
Bone Marrow , Mesenchymal Stem Cells , Rats , Male , Mice , Animals , Bone Marrow/metabolism , Olive Oil , Rats, Wistar , Lung/pathology , Oxidative Stress , Fibrosis , Glutathione/metabolism , Apoptosis , Inflammation/metabolism , Mesenchymal Stem Cells/metabolism , Body Weight , Liver/pathology
2.
Waste Manag ; 82: 249-257, 2018 Dec.
Article in English | MEDLINE | ID: mdl-30509587

ABSTRACT

Environment-friendly and sustainable routes for municipal solid waste (MSW) incineration bottom ash (IBA) recycling and utilization is one of the major concerns for the urbanized countries like Singapore. In this research paper, the possibility of bulk utilization of MSW-IBA as a catalyst support material has been explored for sustainable syn-gas production. The change in the texture of the IBA with simple hydrothermal treatment using NaOH has also been investigated. Furthermore, with hydrothermal treatment for 24 h at 180 °C, the texture of raw IBA with respect to basicity, surface area, total pore volume and reducibility was greatly improved. These textural properties are highly significant for a material to be utilized as a catalyst or catalytic supports for reforming applications. Ni supported on hydrothermally treated IBA was tested for steam reforming of biomass tar reforming reaction between 700 °C and 800 °C at relatively low steam-to-carbon ratio of 2. Among all the catalysts, Ni supported on IBA hydrothermally treated for 24 h gave stable toluene conversion (of 40%) at 700 °C with reduced coke formation (of 7.5 mgC/g·h) than other catalysts. The superior catalytic performance of this catalyst is mainly due to the presence of high amounts of surface Ni° species and improved reducibility and basicity properties among all. The Raman, DT/TGA and XRD analyses on spent catalysts revealed the deposited carbon during steam reforming of tar reaction is majorly amorphous. Due to this, the deposition of carbon did not show any kind of deactivation within the catalyst testing period.


Subject(s)
Incineration , Solid Waste , Biomass , Coal Ash , Nickel , Singapore
3.
Dalton Trans ; 41(46): 14197-203, 2012 Dec 14.
Article in English | MEDLINE | ID: mdl-23047727

ABSTRACT

We demonstrate a much green synthesis method for highly selective synthesis of 6,8-di-t-butylated flavan (6,8-DTBF) by liquid phase alkylation of 2,4-di-t-butylphenol (2,4-DTBP) with cinnamyl alcohol (Cin-OH) over mesoporous Zn-Al-MCM-41 catalysts synthesized under direct basic hydrothermal method. The main alkylated product, 6,8-DTBF is importantly used as an intermediate in the manufacture of biosynthetic organic compounds. The recyclable mesoporous Zn-Al-MCM-41 catalysts have also been reused in this reaction to study their catalytic activities. The influences of various reaction parameters such as temperature, time, ratios of reactant (2,4-DTBP-to-Cin-OH) have been extensively investigated for the synthesis of 6,8-DTBF. In addition, dimethyl sulfoxide (DMSO) has also been used as a solvent in this catalytic reaction. The mesoporous Zn-Al-MCM-41(75) gives excellent catalytic activity with 6,8-DTBF selectivity (86.0%) and 2,4-DTBP conversion (63.1%), and these catalytic results have also compared with that obtained using other mesoporous and microporous catalysts. On the basis of catalytic activity obtained by using the all catalysts, the Zn-Al-MCM-41(75) catalyst is found to be a highly active, recyclable and eco-friendly heterogeneous catalyst in the liquid-phase alkylation of 2,4-DTBP.

4.
Dalton Trans ; 41(46): 14204-10, 2012 Dec 14.
Article in English | MEDLINE | ID: mdl-23064633

ABSTRACT

We approach a green method in the production of alkylaromatic ketones over hexagonally ordered mesoporous CrSBA-15 catalysts, which were used, in green routes, in the liquid-phase oxidation of alkylaromatics. A promising chemical treatment method was used with ammonium acetate solution to remove the toxic nature of non-framework chromium oxides deposited on the surface of calcined CrSBA-15(8), and the obtained green mesoporous CrSBA-15(8) catalyst was used to find its catalytic activity while the recyclability of mesoporous CrSBA-15 catalysts was also studied. Particularly, the mesoporous CrSBA-15 catalysts synthesized with a variety of chromium contents were extensively used in the production of acetophenone (AP=O) with various reaction parameters. On the basis of all catalytic results, the mesoporous CrSBA-15(8) catalyst produced a higher selectivity of alkylaromatic ketones (76-100%) as compared to other CrSBA-15 catalysts and was found to be a highly active, recyclable and promising heterogeneous catalyst for selective synthesis of alkylaromatic ketones.

5.
Dalton Trans ; 41(32): 9633-8, 2012 Aug 28.
Article in English | MEDLINE | ID: mdl-22797675

ABSTRACT

Well hexagonally ordered NbSBA-15 catalysts synthesized by an efficient hydrothermal method were used, for the first time, for the selective synthesis of vitamin K(3) by liquid-phase oxidation of 2-methyl-1-naphthol (2MN1-OH) under various reaction conditions. The recyclable NbSBA-15 catalysts were also reused to find their catalytic activities. To investigate the leaching of non-framework niobium species on the surface of silica networks, the results of original and recyclable NbSBA-15 catalysts were correlated and compared. To find an optimum condition for the selective synthesis of vitamin K(3), the washed NbSBA-15(2.2pH) was extensively used in this reaction with various reaction parameters such as temperature, time and ratios of reactant (2M1N-OH to H(2)O(2)), and the obtained results were also demonstrated. Additionally, the liquid-phase oxidation of 2M1N-OH was carried out with different solvents to find the best solvent with a good catalytic activity. Based on the all catalytic studies, the vitamin K(3) selectivity (97.3%) is higher in NbSBA-15(2.2pH) than that of other NbSBA-15 catalysts, and the NbSBA-15(2.2pH) is found to be a highly active and eco-friendly heterogeneous catalyst for the selective synthesis of vitamin K(3).


Subject(s)
Naphthols/chemistry , Niobium/chemistry , Silicon Dioxide/chemistry , Vitamin K 3/chemical synthesis , Catalysis , Oxidation-Reduction , Porosity , Temperature
6.
Nanotechnology ; 19(25): 255706, 2008 Jun 25.
Article in English | MEDLINE | ID: mdl-21828666

ABSTRACT

A high-yield synthesis of SnO(2) nanoparticles via a facile, economical and easily scalable solid-state molten salt synthesis method has been demonstrated. The inorganic additive, molar ratios of chemicals and annealing temperature were found to control the size and porosity of the SnO(2) nanoparticles. The synthesized SnO(2) nanostructures were uniform, well dispersed and exhibited high crystallinity. Hydrogen sensors made from the SnO(2) nanoparticles were found to possess high sensitivity and stability. Other than tailoring the material's structure in terms of size and porosity, another potential method of enhancing the gas sensitivity is functionalization with noble Pd metal.

7.
Chem Commun (Camb) ; (42): 4396-8, 2007 Nov 14.
Article in English | MEDLINE | ID: mdl-17957298

ABSTRACT

Amine-functionalized mesoporous SBA-15 silica loaded with bovine serum albumin (BSA) has been successfully encapsulated with a thin layer coating of poly(acrylic acid) PAA, with the entrapped BSA being released from the PAA-encapsulated SBA-15 at the higher pH value of 7.4 rather than at the lower pH value of 1.2. This novel drug delivery system has a potential application in the release of protein drug to the site of higher pH value, such as small intestine or colon.


Subject(s)
Drug Compounding/methods , Drug Delivery Systems , Hydrogels/chemistry , Pharmaceutical Preparations/chemistry , Silicon Dioxide/chemistry , Acrylic Resins/chemistry , Circular Dichroism , Hydrogen-Ion Concentration , Microscopy, Electron, Transmission , Proteins/chemistry , Serum Albumin, Bovine/chemistry , Tetrazolium Salts , Thiazoles
8.
Langmuir ; 21(21): 9568-75, 2005 Oct 11.
Article in English | MEDLINE | ID: mdl-16207037

ABSTRACT

Mesoporous SBA-15 materials were functionalized with amine groups through postsynthesis and one-pot synthesis, and the resulting functionalized materials were investigated as matrixes for controlled drug delivery. The materials were characterized by FTIR, N(2) adsorption/desorption analysis, zeta potential measurement, XRD, XPS, and TEM. Ibuprofen (IBU) and bovine serum albumin (BSA) were selected as model drugs and loaded onto the unmodified and functionalized SBA-15. It was revealed that the adsorption capacities and release behaviors of these model drugs were highly dependent on the different surface properties of SBA-15 materials. The release rate of IBU from SBA-15 functionalized by postsynthesis is found to be effectively controlled as compared to that from pure SBA-15 and SBA-15 functionalized by one-pot synthesis due to the ionic interaction between carboxyl groups in IBU and amine groups on the surface of SBA-15. However, SBA-15 functionalized by one-pot synthesis is found to be more favorable for the adsorption and release of BSA due to the balance of electrostatic interaction and hydrophilic interaction between BSA and the functionalized SBA-15 matrix.


Subject(s)
Diazepam/chemistry , Drug Carriers , Ibuprofen/chemistry , Serum Albumin, Bovine/chemistry , Silicon Dioxide/chemistry , Drug Interactions , Drug Therapy/methods , Microscopy, Electron , Models, Molecular , Spectroscopy, Fourier Transform Infrared , Surface Properties , X-Ray Diffraction
9.
Langmuir ; 21(4): 1171-4, 2005 Feb 15.
Article in English | MEDLINE | ID: mdl-15697256

ABSTRACT

Thin films of silicate MCM-41 and silicate MCM-48 have been prepared on porous ceramic supports by the hydrothermal method. A comparative study of template removal has been made on supported thin films and on powder. By supercritical fluid extraction (SFE) with CH(3)OH-modified CO(2), at least 78% of the template can be removed from as-synthesized materials at 85 degrees C. X-ray diffraction (XRD) observations indicate that the resulting supported thin films after SFE are structurally stable and ordered with a weak pore contraction. The advantages of SFE over calcination in template removal are presented with a series of results obtained on supported thin films and on powder by XRD and N(2) adsorption-desorption.

10.
Talanta ; 66(4): 943-51, 2005 May 15.
Article in English | MEDLINE | ID: mdl-18970076

ABSTRACT

Extraction of cationic surfactant templates from MCM-41, MCM-48, SBA-1 and SBA-3 has been conducted using CH(3)OH-modified CO(2) supercritical fluid. The supercritical fluid extraction (SFE) has been integrated with thermogravimetry (TG), X-ray diffraction (XRD) and N(2) adsorption-desorption to evaluate extraction efficiency and structural stability of mesoporous materials. Experiments of optimization indicate that the conditions of 90bar, 85 degrees C, CH(3)OH/CO(2)=0.1/1.0ml/min and 3h are most suitable for the SFE of cationic templates. 76-95% of the cationic templates can be extracted from the mesoporous materials. XRD and N(2) adsorption-desorption studies illustrate that SFE possesses some advantages over calcination in maintaining mesoporous uniformity and structural stability when used to remove templates. The impact of curing on mesoporous structure is also dealt with.

11.
Langmuir ; 20(21): 9130-7, 2004 Oct 12.
Article in English | MEDLINE | ID: mdl-15461497

ABSTRACT

Moderate basic sites could be created onto mesoporous Si-MCM-41 materials by postsynthesis modification with highly dispersed La2O3. The La2O3-modified MCM-41 materials (designated here as LaM) have been characterized by Fourier transform infrared spectroscopy, temperature-programmed desorption, X-ray photoelectron spectroscopy, X-ray diffraction (XRD), and N2 adsorption/desorption and have been tested as model adsorbents for CO2 adsorption. XRD and N2 adsorption results showed that all LaM materials still maintained their uniform hexagonal mesoporous structure even after postsynthesis modification with La2O3 loading up to 20 wt %. Although the surface area, pore size, and pore volume of LaM materials decreased with increasing La2O3 loading, their capacity for CO2 storage could be significantly improved when La2O3 loading was increased from 0 to 10 wt %. Unidentate and bidentate carbonates have been identified by in situ FTIR as the two types of CO2 species adsorbed on LaM surface. The LaM material also possesses good thermal stability, allowing the model adsorbent to be regenerated at high temperature and recyclable.


Subject(s)
Carbon Dioxide/chemistry , Lanthanum/chemistry , Membranes, Artificial , Organosilicon Compounds/chemistry , Oxides/chemistry , Silicon/chemistry , Adsorption , Particle Size , Surface Properties , Temperature
12.
Talanta ; 45(4): 759-66, 1998 Feb.
Article in English | MEDLINE | ID: mdl-18967059

ABSTRACT

Mesoporous SnO(2) with high surface areas were synthesized using a cationic surfactant (N-cetyl-N,N,N-trimethylammonium bromide) as a synthetic template. Acidity of the starting synthesis slurry was used as one of the controlling parameters for the synthesis. After the SnO(2) was synthesized at pH 7.15, it was calcined at 723 K for 10 h in air. It had a BET surface area of 156.8 m(2) g(-1) with a pore diameter of 38.4 A. Infrared spectroscopy (FTIR) and thermal analysis techniques (thermogravimetry and differential thermal analysis) showed that the surfactant was incorporated in the mesopores of SnO(2) and calcination in air at 673-723 K was needed to remove the surfactant completely from the mesopores. The effects of SnO(2) surface area on its gas sensing properties were also investigated. It was observed that SnO(2) with higher surface areas had much higher sensitivities to hydrogen at 573 K.

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