The aim of this paper is to discuss on the roles of plant extract in the synthesis of metallic nanoparticles. Synthesis of metallic nanoparticles has started few decades ago through physical and chemical methods. Recently, green technology through biosynthesis method has drawn great attention compared to the physical and chemical method. Biosynthesis was found to be more energy efficient and able to eliminate the use of hazardous chemicals. The biosynthesis studies involved the application of fungi, bacteria, yeast, algae and plant extract. Plant extract has several advantages since the use of microorganism required stringent control on cell culture. Furthermore, the reaction rate is much faster as compared to that of the microorganism methods. The important compounds in the plant extract are hydroxyl and carbonyl groups. Both functional groups allowed plant extract to act as reducing agent as well as stabilizing agent. Several studies have been carried out to optimize the extraction of these compounds such as plant drying technique, extraction temperature and type of extractions solvent. The common method used to quantify the concentration of reducing agents in the extract is through Folin-Ciocalteu method. Utilization of plant extract not only capable of producing well dispersed monometallic nanoparticles, but also bimetallic nanoparticles. Previous studies revealed that concentration of plant extract has significant effect on particle size and shape as well as particle distribution.
A series of experiments were conducted in water to study mixing in the field of a single, two-dimensional vortex. The experimental configuration is that of a laminar line vortex initiated along a diffusion layer between two streams of different scalar concentrations. Measurements of passive scalars in inert and chemically reactive environments were made using a planar laser-induced fluorescence technique. A fast acid/base isothermal reaction was utilized to highlight the molecular mixing. The experimental results show that the mixing enhancement in the presence of a vortex is linearly dependent on the vortex strength and the time elapsed since vortex initiation. In particular, the mixedness, defined as the spatially integrated second moment of concentration field in the vortex, and the spatially averaged scalar dissipation are found to follow this dependence. This variation is mainly attributed to the contact area generation along the diffusion layers between the two streams as a result of inviscid deformations in the vortical flow field. The results presented pertain to mixing in liquids and in the limit of high Schmidt numbers.
ObjectiveTo determine whether pre-treatment with high-dose ulinastatin provides enhanced postoperative oxygenation in patients who have undergone aortic valve surgery with moderate hypothermic cardiopulmonary bypass (CPB).MethodsPatients who underwent aortic valve surgery with moderate hypothermic CPB were retrospectively evaluated. In total, 94 of 146 patients were included. The patients were classified into one of two groups: patients in whom ulinastatin (10,000 U/kg followed by 5,000 U/kg/h) was administered during CPB (Group U, n = 38) and patients in whom ulinastatin was not administered (Group C, n = 56). The PaO2/FiO2 ratio was calculated at the following time points: before CPB (pre-CPB), 2 h after weaning from CPB (post-CPB), and 6 h after arrival to the intensive care unit (ICU-6). The incidence of a low PaO2/FiO2 ratio was also compared among the time points.ResultsGroup U showed a significantly higher PaO2/FiO2 ratio (F(4, 89.0) = 657.339) and a lower incidence of lung injury (PaO2/FiO2 ratio < 300) than Group C at the post-CPB and ICU-6 time points.ConclusionHigh-dose ulinastatin improved pulmonary oxygenation after CPB and in the early stages of the ICU stay in patients undergoing aortic valve surgery with CPB.
-The hydroxyl groups of the polyphenols are capable to act as reducing agent for reduction reaction. The effect of drying temperature, extraction temperature and extraction duration were evaluated using central composite design which consists of 20 experimental runs. Response surface methodology (RSM) was used to estimate the optimum parameters in extracting polyphenols from the palm leaves. The correspondence analysis of the results yielded a quadratic model which can be used to find optimum conditions of extraction process. The optimum extraction condition of drying temperature, extraction temperature and extraction duration are 70°C, at 70°C of 10 minutes, respectively. Total polyphenols were determined by application of the Folin-Ciocalteu micro method and the extract was found contain of 8 mg GAE/g dry palm leaves at optimum conditions.
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