In vitro propagation of Maytenus ilicifolia (Celastraceae) as potential source for antitumoral and antioxidant quinomethide triterpenes production. A rapid quantitative method for their analysis by reverse-phase high-performance liquid chromatography

Cell culture of Maytenus ilicifolia were established in order to produce and to quantify the antitumoral and antioxidant quinonemethide triterpenes. In vitro calli were induced from leaf explants of native plants and cultured in semi-solid medium under controlled conditions of humidity, temperature and photoperiod. The quinonemethide triterpenes showed maximum accumulation in the logarithmic phase growth of the cell culture. A rapid, sensitive and reliable reverse-phase HPLC method was used for quantitative determination of the antitumoral and antioxidant quinonemethide triterpenes, 22β-hydroxymaytenin and maytenin in callus of Maytenus ilicifolia. Well resolved peaks with good detection response and linearity in the range 1.0 - 100 μg/mL were obtained. This quantitative work was performed by an external standard method.

Determination of flutamide in tablets by high-performance liquid chromatography

Flutamide is a potent antiandrogen used for the treatment of prostatic cancer. A simple, sensitive and accurate high-performance liquid Chromatographic (HPLC) method is presented for quantitative determination of flutamide in tablets, using a reversed-phase technique and UV detection at 240 nm. The isocratic elution was used to quantify the analyte. The samples were chromatographed on Luna-C18 column and the mobile phase was 0.05 M phosphate buffer pH 4.0 - acetonitrile (50:50, v/v). The method was linear between 2.9 - 11.6 mg L -1. Over the tested concentration range the intra-day relative standard deviation for replicate analysis in tablets ranged from 0.44 to 0.78%. It was also found that the excipients in the commercial tablets did not interfere with the method.

A load cell for grain-propelled ballistic rocket thrust measurement

A 1000-kgf resistive strain-gauge load cell has been developed for quality testing of rocket propellant grain. A 7075-T6 aluminum alloy has been used for the elastic column, in which 8 uniaxial, 120-Ω strain gauges have been bonded and connected to form a full Wheatstone bridge to detect the strain. The chosen geometry makes the transducer insensitive to moments and, also, to the temperature. Experimental tests using a universal testing machine to imposed compression force to the load cell have demonstrated that its behavior is linear, with sensitivity of 2.90 μV/kgf ± 0.34%, and negligible hysteresis. The designed force transducer response to a dynamic test has been comparable to that of a commercial load cell. © 2005 IEEE.

Microstructural and electrical properties of the sofc anode precursor YSZ/NiO composite prepared by A liquid mixture technique

A detailed study of the microstructural and electrical properties of the yttria-stabilized zirconia/nickel oxide (YSZ/NiO) composite was performed. This material is the precursor to the solid oxide fuel cell anode cermet YSZ/Ni. A liquid mixture technique was developed to produce the YSZ/NiO composite to fabricate high-performance SOFC anodes. This technique resulted in fine and homogeneous powders and specimens with high electrical conductivity. The combined results showed that this technique is suitable for the production of the anode cermet.

High-performance liquid chromatography determination of praziquantel in tablets and raw materials

A specific and sensitive high-performance liquid chromatographic method was developed for the assay of praziquantel in raw materials and tablets. It was also found that the excipients in the commercial tablet preparation did not interfere with the assay in the wavelenght selected. The method validation yielded good results and included the range, linearity, precision, accuracy, specificity and recovery.