Preparation of a novel positively charged nanofiltration composite membrane incorporated with silver nanoparticles for pharmaceuticals and personal care product rejection and antibacterial properties.

A novel positively charged N-[(2-hydroxy-3-trimethylammonium)propyl] chloride chitosan (HTCC)-Ag/polyethersulfone (PES) composite nanofiltration membrane was easily prepared by coating the active layer, HTCC, onto PES as the support through epichlorohydrin as the cross-linking reagent and nano-Ag particles as the introduced inorganic components. Scanning election microscopy, X-ray photoelectron spectroscopy, atomic force microscopy, and X-ray diffraction were employed to characterize the morphology of the resultant membranes, of which the molecular weight cut-off was about 941 Da. At 25 °C, the pure water permeability is 16.27 L/h·m(2)·MPa. Our results showed that the rejection of pharmaceuticals and personal care products (PPCPs) followed the sequence: atenolol > carbamazepine > ibuprofen, confirming that the membranes were positively charged. The antibacterial properties of the membranes were compared to elucidate the existence of Ag nanoparticles which help to improve antibacterial activity against Gram-negative Escherichia coli (DH5α, Rosetta) and Gram-positive Bacillus subtilis. The inhibition zone diameters of HTCC-Ag/PES membranes towards E. coli DH5α, E. coli Rosetta and Bacillus subtilis were 17.77, 16.18, and 15.44 mm, respectively. It was found that HTCC-Ag/PES membrane has a better antibacterial activity against E. coli than against Bacillus subtilis, especially for E. coli DH5α.

Bacterial immune interaction in experimental colitis.

OBJECTIVES: This study aimed to analyze the effects of 5-aminosalicylic acid (5-ASA) on intestinal microbiota and immune regulation in inflammatory bowel disease (IBD) and to investigate the correlation between intestinal microbiota and immune factors. METHODS: Colitis in mice was induced by oxazolone. The community composition of luminal and mucosal microbiota was analyzed by a terminal restriction fragment length polymorphism. The expression of occludin, toll-like receptor (TLR)-2, TLR-4 and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) p65 proteins were measured by immunohistochemistry and Western blot. Linear correlation between intestinal microbial community and the severity of the colitis or intestinal microbial community and expressions of immune factors were determined. RESULTS: Protective bacteria decreased while aggressive bacteria increased in the colitis group. The richness and diversity of both luminal and mucosal microbiota decreased in the colitis group the decrease was enhanced in the 5-ASA-treated group. The diversity of mucosal microbiota significantly correlated with the extent of the colitis. Expressions of occludin, TLR-2, TLR-4, tumor necrosis factor-α and NF-κB p65 were significantly correlated with the diversity of mucosal microbiota. CONCLUSIONS: Mucosal microbiota are important in the pathogenesis of IBD. 5-ASA increases protective bacteria but decreases aggressive bacteria, thus inducing the new intestinal microbial homeostasis.

[Adsorption behaviors of chitosan and the analysis of FTIR spectra].

This paper studied the adsorption behavior of lab-made chitosan for acid dyeing waste water and basic dyeing waste waters, based on the effects of adsorbing time, deacetylation degree of chitosan, and pH of waste water. The results showed that the adsorption of basic fuchsin and saffron by the chitosan almost reached equilibrium state in 20 min. The adsorption capacities of the chitosan for dyes was comparable with activated carbon. Moreover, its dosages were only 2/3 of the latter. The adsorption process for Acid Red presented a dynamics character of first order reaction. FTIR spectroscopy was used to analyze the adsorption mechanisms of chitosan for different kinds of dyes. It was found that a great deal of hydroxide radicals in the chitosan molecule participated in the adsorption of basic fuchsin and saffron.

[Studies on spectral characteristics of solid propellant by remote sensing FTIR].

The infrared spectral characteristics of high-intensity IR solid propellant were measured in this paper using a Bruker EQUINOX55 remote sensing FTIR spectrometer. The emission spectra of the combustion flame were recorded in the range of 4700-1800 cm(-1) with a spectral resolution of 4 cm(-1). The combustion temperatures of solid propellant at the burning time of 0, 9, 18, 27 and 36 s calculated from the molecular rotation-vibration spectra were 1992.5, 1610.9, 2294.4, 2361.1 and 1916.9 K, respectively. Moreover, the spectral radiance distributions of the high IR flare material at different times were given, and the combustion product concentrations of HCl, HF, CO2 and CO were determined quantitatively. Results showed that remote sensing FTIR is a potential technology that can be applied to the measurement of IR spectral characteristics, especially to the identification of the IR objects, guidance and anti-guidance in the military, and the modification of the make-up of solid propellant.

Monitoring leaking gases by OP-FTIR remote sensing.

Measurement of leaking gases using Open Path Fourier Transform Infrared (OP-FTIR) spectroscopy was carried out in this study to acquire Path Integrated Concentration (PIC) data. Three hazardous Volatile Organic Compounds (VOCs) namely methylene chloride, chloroform and acetone were analyzed. For the two-component leaking source, the PIC data were easily obtained through ordinary calculation and compared to those obtained from Artificial Neural Network (ANN). When the leaking source was composed of three VOCs whose characteristic peaks interfere with each other, it was necessary to do spectral correction for multicomponent analysis with ANN. The Absorbance-Wavenumber-Time 3D spectra of the leaking sources and concentration variations with the leaking time were plotted. The results showed that OP-FTIR is a good quantitative analytical method for indoor or field air pollution. Further more, the remote sensing OP-FTIR system could be utilized to continuously monitor many more toxic gases and work as an alert system for the real time monitoring of hazardous gases beyond normal working conditions of various kinds of areas, such as living or industrial areas.

[Reconstruction algorithms of computed tomography of remote sensing FTIR].

Reconstruction algorithms of computed tomography-remote sensing fourier transform infrared spectroscopy plays a key role in fast and cost-effective acquirement of gas concentration distribution. Ideally, a reconstruction algorithm can be used to obtain good reconstruction maps only by limited number of measurements and non-symmetric ray configurations, even in the presence of instrument noise, measurement error, poor beam geometry, and variations in the contaminant spatial distribution. Several conventional reconstruction algorithms used to reconstruct two-dimensional concentration maps of the vapor contaminants by remote sensing FTIR, such as ART, MART, SIRT and SBFM, have been reviewed in this paper. Comparing to ART, MART has the advantages of iterative speed and iterative precision, while SIRT overcomes the problem of illegibility and SBFM can reduce the noise sharply.

[Calibration of EQUINOX55 remote sensing FTIR emission system].

In order to obtain the infrared spectral radiance distribution of the emission spectrum or the concentration of the gases, the calibration of FTIR emission system is necessary for obtaining an instrument response function of the system. This paper gives the effect of the temperature of the standard blackbody for calibration of EQUINOX55 remote sensing FTIR emission system on the instrument response function. The result illustrates that the values of the instrument response functions increase as the blackbody temperature increased, and tends to a limit.

[Remote sensing FTIR and computed tomography for air pollution].

Gas concentration mapping with computed tomography-remote sensing fourier transform infrared spectroscopy demonstrates that this system and reconstruction method can be directly applied in many environmental and industrial settings. This development of reconstruction algorithm can greatly broaden the application of CT to obtain rapid reconstruction of ambient air pollution data.

[Comparison of four multivariate calibration methods in simultaneous determination of air toxic organic compounds with FTIR spectroscopy].

The concentration determination abilities of four multivariate calibration methods--classical least squares (CLS), partial least squares (PLS), kalman filter method (KFM) and artificial neural network (ANN) were compared in this paper. Five air toxic organic compounds--1,3-butadiene, benzene, o-xylen, chlorobenzene, and acrolein--whose FTIR spectra seriously overlap each other were selected to compose the analytical objects. The evaluation criterion was according to the mean prediction error (MPE) and mean relative error (MRE). Results showed that PLS was superior to other methods when treating multicomponent analysis problem, while there was no comparable difference between CLS, KFM and ANN.