Preparation of radioidinated L-α-methyl tyrosine by the oxidative radioiodination using chloramine-T (CAT) and iodogen (1,3,4,6-tetrachloro,-3α,
6α-diphenyl glycoluril) to generate electrophilic radioiodine has been carried out. The factors affecting the labeling yield
such as pH of the medium, reaction time, substrate and oxidizing agent concentrations have been investigated to optimize the
conditions for the preparation of radioiodinated L-α-methyl tyrosine in high radiochemical yields. Side product impurities
were observed at long reaction times and high oxidizing agent concentrations. Maximum radiochemical yields of 89.7±1.5% and
87.8±1.6% were obtained in case of CAT and iodogen, respectively. Separation and purification by high pressure liquid chromatography
(HPLC) resulted in radiochemically pure products. Using high specific activity123I, the SPECT brain imaging agent can be prepared. 相似文献
The extraction of Co3+ from 0.1M aqueous acetate medium buffered to pH 5.3 by thenoyltrifluoroacetone (HTTA) in benzene and by 8-quinolinol (HQ) also in benzene at various temperatures has been studied. The species formed were Co(OH)2 (TTA)·(HTTA)2 and Co(Q3)·2HQ, respectively. 1,10-phenanthroline (Phen) as a base was also mixed with HTTA to form the species Co(OH)2(TTA)·(HTTA). Phen and Co(OH)2 (TTA)(HTTA)·2Phen. No synergism was observed upon the addition of Phen to HQ. 相似文献
We describe models and exact solutions approaches for an integrated aircraft fleeting and routing problem arising at TunisAir.
Given a schedule of flights to be flown, the problem consists of determining a minimum cost route assignment for each aircraft
so as to cover each flight by exactly one aircraft while satisfying maintenance activity constraints. We investigate two tailored
approaches for this problem: Benders decomposition and branch-and-price. Computational experiments conducted on real-data
provide evidence that the branch-and-price approach outperforms the Benders decomposition approach and delivers optimal solutions
within moderate CPU times. On the other hand, the Benders algorithm yields very quickly high quality near-optimal solutions. 相似文献
Two new 5‐substituted 1,3,4‐thiadiazole‐2‐carboxylate esters have been synthesized via ring closure of appropriate tricarbonyl precursors using Lawesson's reagent. The chemistry described is the first report of such methodology in the organic literature. The new materials display broad smectic C phases and show considerable potential for use in electrooptic display devices. 相似文献
Nonlinear Dynamics - Jaya algorithm is one of the recent algorithms developed to solve optimization problems. The basic concept of this algorithm consists in moving the obtained solution, for a... 相似文献
We answer a question of E. Kirchberg (personal communication): does the relative commutant of a separable C∗-algebra in its ultrapower depend on the choice of the ultrafilter? 相似文献
A new method for obtaining strong S-boxes based on chaotic map and Teaching–Learning-Based Optimization (TLBO) is presented in this paper. Our method presents eight rounds; each round contains two transformations: row left shifting and columnwise rotation. The vectors for the transformations are different from one round to another, and they are controlled by two keys to the logistic map. These two keys are optimized by using TLBO which aims to construct a strong S-box that satisfies to the criteria set in advance. Test for the following criteria such as bijectivity, nonlinearity, strict avalanche criteria, equiprobable inputs/outputs XOR distribution is analyzed. Additionally, we will provide many comparisons with other S-boxes and test of the sensitivity to keys. The results of performance test show that the proposed design S-boxes presents good cryptography proprieties and can resist to several attacks. 相似文献
We study the local and global well-posedness of the periodic boundary value problem for the nonlinear Schrödinger-Boussinesq system. The existence of periodic traveling-wave solutions as well as the orbital stability of such solutions are also considered. 相似文献
The need for some economic strategies for increased growth and nutraceuticals of medicinal plants is well acknowledged now. It was hypothesized that external magnetic field treatment (MFT) of seeds affecting internal magnet of cells may affect growth and metabolism. In this study, seeds were subjected to pre-sowing magnetic field (50 mT at 5 mm for 5 s). At vegetative stage, the leaf growth, chlorophyll content, catalase (CAT), peroxidase (POD), amino acids, proteins, flavonoids, soluble sugars, total soluble phenolics, carotenoids, anthocyanins, phenolic profile (HPLC based), and antimicrobial activity of leaves (in terms of the minimum inhibitory concentration against Staphylococcus aureus and Pseudomonas aeruginosa) were studied. Yield was evaluated for nutritive components in fruit (peel+pulp) and peel. MFT improved germination percentage, growth, leaf chlorophyll, antimicrobial activity, peel amino acids, phenolics, and POD with negligible effect on fruit nutritive value. Moreover, photosynthetic pigments and cinnamic acid exhibited direct correlation with antimicrobial potential against both pathogens. However, sinapic acid showed positive correlation against Staphylococcus aureus only. Cinnamic acid, coumaric acid, syringic acid, and quercetin were in direct correlation against Pseudomonas aeruginosa; it was directly correlated with total flavonoids too. In conclusion, magnetic field can be used to manipulate plant cell metabolism promising improvement of growth, antimicrobial activity, and phenolics of interest.
In this study, a controlled-release formulation of duplex herbicides, namely, 2,4,5-trichlorophenoxybutyric acid (TBA) and 3,4-dichlorophenoxy-acetic acid (3,4D), was simultaneously embedded into Zn-Al-layered double hydroxides (LDHs). The resulting nanohybrid Zinc-Aluminium-3,4D-TBA (ZADTX) was composed of a well-ordered crystalline layered structure with increasing basal spacing from 8.9 Å to 20.0 Å in the Powder X-ray Diffraction (PXRD) with 3,4D and TBA anions located in the gallery of LDHs with bilayer arrangement. The release of 3,4D and TBA fit the pseudo-second-order model. This duplex nanohybrid possessed a well-controlled release property (53.4% release from TBA and 27.8% release from 3,4D), which was highly effective, requiring the use of a small quantity and, hence, environmentally safer. 相似文献