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991.
In this paper, we utilized the instinct peroxidase-like property of Fe3O4 magnetic nanoparticles (MNPs) to establish a new fluorometric method for determination of hydrogen peroxide and glucose. In the presence of Fe3O4 MNPs as peroxidase mimetic catalyst, H2O2 was decomposed into radical that could quench the fluorescence of CdTe QDs more efficiently and rapidly. Then the oxidization of glucose by glucose oxidase was coupled with the fluorescence quenching of CdTe QDs by H2O2 producer with Fe3O4 MNPs catalyst, which can be used to detect glucose. Under the optimal reaction conditions, a linear correlation was established between fluorescence intensity ratio I0/I and concentration of H2O2 from 1.8 × 10−7 to 9 × 10−4 mol/L with a detection limit of 1.8 × 10−8 mol/L. And a linear correlation was established between fluorescence intensity ratio I0/I and concentration of glucose from 1.6 × 10−6 to 1.6 × 10−4 mol/L with a detection limit of 1.0 × 10−6 mol/L. The proposed method was applied to the determination of glucose in human serum samples with satisfactory results. 相似文献
992.
Syed Shahed Ali 《中国化学快报》2011,22(7):793-796
Various 2-phenylimidazo[4,5-f][1,10]phenanthrolines were synthesized from potassium ferro-cyanide trihydrate(KFCT) complex catalyzed three component reaction of 1,10-phenanthroiine-5,6-dione,aromatic aldehydes and ammonium acetate at room temperature in excellent isolated yield.This is a simple and straight forward,high yielding,not involving any hazardous or expensive catalyst method. 相似文献
993.
Clospore: a liquid medium for producing high titers of semi-purified spores of Clostridium difficile
Clostridium difficile continues to cause infections in healthcare and other settings. Its spores survive well indoors and require sporicidal chemicals for infection control. However, proper testing of disinfectants is impeded due to difficulties in obtaining viable spores of high enough quality and titers to meet current regulations for sporicidal claims. A new liquid medium (Clospore) has been developed, based on a systematic review of the compositions of 20 other available media. C. difficile spores grown in the new medium and treated with a mixture of lysozyme and trypsin yielded final suspensions with > 10(9) CFU/mL of viable spores, with a purity of > 91% as tested by spore-staining and phase-contrast microscopy. The spores showed a biological decay rate of about 0.1 log10/month when dried on metal disks and stored indoors (air temperature 23 +/- 2 degrees C; relative humidity 52.76 +/- 15.08%). Heating the purified spore suspensions to 70 degrees C for 10 min to inactivate any vegetative cells showed no spore activation or inactivation. The spores could be stored for at least 14 months either refrigerated (4 degrees C) or frozen (-20 or -80 degrees C) in 50% (v/v) ethanol with virtually no loss in viability. The resistance of the enzyme-treated spores to three levels of sodium hypochlorite (1000, 3000, and 5000 ppm), using a standardized quantitative carrier test, was almost identical to that of the spores concentrated by centrifugation alone. The described procedure has been successfully applied to four standard (ATCC) and six clinical strains of C. difficile. 相似文献
994.
Radiocomplexation of fleroxacin (FXN) with technetium-99m and its characterization in terms of in vitro stability in saline
and serum solutions, in vitro binding with live and heat-killed Escherichia coli, and biodistribution in male Wistar rats (MWR) artificially infected with live and heat-killed E. coli was studied. The 99mTc-FXN complex showed a radiochemical purity (RCP) yield of 98.10 ± 0.24% at 30 min using 125 μg of stannous fluoride, 74 MBq
of sodium pertechnetate, and 2 mg of FXN. The complex was found to be more than 90% stable up to 4 h after constitution in
normal saline. In serum, the emergence of 16.50% undesirable species was observed within 16 h of incubation at 37 °C. The
99mTc-FXN complex showed saturated in vitro binding with E. coli with a maximum value of 65.00% at 90 min. A fivefold increase in uptake of the complex was noted in the infected when compared
with the inflamed and normal muscle of the MWR infected with live E. coli. The stable radiochemical profile in saline and serum, saturated in vitro binding with E. coli and increased uptake in the infected muscle, confirmed the potential of the 99mTc-FXN complex as an E. coli infection imaging agent. 相似文献
995.
In situ photoexcitation of silver-doped titania nanopowders for activity against bacteria and yeasts
Kowal K Wysocka-Król K Kopaczyńska M Dworniczek E Franiczek R Wawrzyńska M Vargová M Zahoran M Rakovský E Kuš P Plesch G Plecenik A Laffir F Tofail SA Podbielska H 《Journal of colloid and interface science》2011,362(1):50-57
Photocatalytic and in situ microbial activity of the amorphous and annealed states of Ag-doped and un-doped titania were examined. Studies on their structure, morphology, composition, and the photo-absorption characteristics of these materials were performed. These results were correlated with the photocatalytic and microbial activity against methicillin resistant Staphylococcus aureus K324 (MRSA), methicillin susceptible S. aureus ATCC 25923 (MSSA), Escherichia coli PA 170, and yeasts Candida albicans ATCC 90028. The annealed powders containing anatase form of titania exhibited relatively higher photocatalytic activity,corresponding to activity against MRSA,when exposed to UV-A radiation. In comparison, amorphous powders exhibited low photoactivity and showed poor antibacterial performance against MRSA under UV-A exposure. Doping of amorphous titania with Ag resulted in an anti-MRSA effect without exposure to UV radiation. In the Ag-doped crystalline anatase samples, the size of Ag primary nanocrystallites increased, which led to the decrease in the surface concentration of Ag and detriment anti-MRSA activity. 相似文献
996.
In this paper, the global asymptotic stability problem of Takagi–Sugeno (TS) fuzzy Cohen–Grossberg Bidirectional Associative Memory neural networks (FCGBAMNNs) with discrete and distributed time-varying delays is considered. A novel LMI-based stability criterion is obtained by using Lyapunov functional theory to guarantee the asymptotic stability of FCGBAMNNs which are represented by TS fuzzy models. Our results can be easily verified and are also less restrictive than previously known criteria and can be applied to Cohen–Grossberg neural networks, recurrent neural networks and cellular neural networks. Finally, the proposed stability conditions are demonstrated with a numerical example. 相似文献
997.
Given a convex polyhedron P of n vertices inside a sphere Q, we give an O(n
3)-time algorithm that cuts P out of Q by using guillotine cuts and has cutting cost O(log2
n) times the optimal. 相似文献
998.
Syed?Muhammad?Jawwad?RiazEmail author Azad?A.?Siddiqui 《General Relativity and Gravitation》2011,43(4):1167-1178
In this paper we present non-singular coordinates for the rotating BTZ (Banados–Teitelboim–Zanelli) black hole. The approach
is further extended to construct non-singular coordinates for different cases of general circularly symmetric black holes
in 2 + 1 dimensions. 相似文献
999.
Rastegari Arezoo Safavi Maliheh Vafadarnejad Fahimeh Najafi Zahra Hariri Roshanak Bukhari Syed Nasir Abbas Iraji Aida Edraki Najmeh Firuzi Omidreza Saeedi Mina Mahdavi Mohammad Akbarzadeh Tahmineh 《Molecular diversity》2022,26(1):409-428
Molecular Diversity - Alzheimer’s disease (AD) is now ranked as the third leading cause of death after heart disease and cancer. There is no definite cure for AD due to the multi-factorial... 相似文献
1000.
In this article, a novel (G'/G)-expansion method is proposed to search for the traveling wave solutions of nonlinear evolution equations. We construct abundant traveling wave solutions involving parameters to the Boussinesq equation by means of the suggested method. The performance of the method is reliable and useful, and gives more general exact solutions than the existing methods. The new (G'/G)-expansion method provides not only more general forms of solutions but also cuspon, peakon, soliton, and periodic waves. 相似文献