Preparative isolation of (+)-beta-eudesmol fromAmyris balsamifera

Summary Optically pure (+)-beta-eudesmol is a possible starting material for the synthesis of several termite defense compounds. A two step procedure for the isolation of gram quantities of (+)-beta-eudesmol from commercially availableAmyris balsamifera oil (syn. West Indian sandalwood oil), containing 8% beta-eudesmol, was developed. Step one consisted of an efficient vacuum distillation of the total oil. Step two was a medium pressure LC separation with an AgNO₃ impregnated silica gel stationary phase. Several other separation procedures failed due to the presence of many closely related sesquiterpene alcohols (75% of the oil).     

Constraint isomorphism and correction algorithms for violations

When a problem can be characterized by different parameter sets, constraints imposed on one parameter set must be consistent with, or isomorphic to, constraints imposed on other parameter sets. When mapping among the parameter sets is not so visibly obvious, one might overlook consistency violations, which have occurred in the past. This paper examines such violations and possible correction algorithms. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)     

Sol–gel preparation and photoluminescence properties of Ce-activated Y3Al5O12 nano-sized powders

Trivalent cerium-doped yttrium aluminum garnet (YAG:Ce³⁺) nanoparticles were successfully prepared by a facile sol–gel technique. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and photoluminescence (PL) spectroscopy were used to characterize the as-prepared phosphors. Well-crystallized fine nanoparticles were obtained at 1000 °C. Single-crystal nanoparticles with irregular shapes were obtained, with crystallite sizes ranging between 20 and 60 nm. PL intensity of the particles increased monotonically with decreasing Ce doping concentration and showed the maximum value at 0.1 at%.     

Investigations into beam monitors at the AEg ̄ IS experiment

Detailed diagnostic of antiproton beams at low energies is required for essentially all experiments at the Antiproton Decelerator (AD), but will be particularly important for the future Extra Low ENergy Antiproton ring (ELENA) and its keV beam lines to the different experiments. Many monitors have been successfully developed and operated at the AD, but in particular beam profile monitoring remains a challenge. A dedicated beam instrumentation and detector test stand has recently been setup at the AE \(\bar {g}\) IS experiment (Antimatter Experiment: Gravity, Interferometry, Spectroscopy). Located behind the actual experiment, it allows for parasitic use of the antiproton beam at different energies for testing and calibration. With the aim to explore and validate different candidate technologies for future low energy beam lines, as well as the downstream antihydrogen detector in AE \(\bar {g}\) IS, measurements have been carried out using Silicon strip and pixel detectors, a purpose-built secondary emission monitor and emulsions. Here, results from measurements and characterization of the different detector types with regard to their future use at the AD complex are presented.     

The effects of gum arabic oral treatment on the metabolic profile of chronic renal failure patients under regular haemodialysis in Central Sudan

This study aimed at assessing the effect of gum arabic (Acacia senegal) oral treatment on the metabolic profile of chronic renal failure (CRF) patients. A total of 36 CRF patients (under regular haemodialysis) and 10 normal subjects participated in this study. The patients were randomly allocated into three groups-group A: 12 CRF patients under low-protein diet (LPD) (<40 g day(-1)) and gum arabic (50 g day(-1)) treatment; group B: 14 CRF patients under LPD and gum arabic, iron (ferrous sulphate, 200 mg day(-1)) and folic acid (5 mg day(-1)) treatment; group C (control group): 10 CRF patients under LPD and iron and folic acid treatment and group D: 10 normal volunteers (on normal diet) under daily dose of 50 g gum arabic. Each of the above treatments was continued for three consecutive months. Blood samples were collected from each subject before treatment and twice per month "pre-dialysis" for 3 months. Biochemical parameters measured were: serum urea, serum creatinine, serum uric acid, serum calcium and serum phosphorus. By the end of the 3 months of treatment, serum urea levels significantly decreased by 31.2 and 44.18% for group A and B, respectively, compared with the baseline (0.01 < p < 0.001) and control group (p < 0.05). Serum creatinine levels significantly decreased in the groups of gum users (A, B and D) by 9.94, 12.65 and 11.7%, respectively, compared with the control group (p < 0.001). There was a significant decrease (p < 0.05) in serum uric acid levels by 14 and 19.9% for group A and B, respectively, compared with the baseline. Serum calcium levels increased by 12.64, 15.75 and 8.75% for group A, B and D, respectively, and these increases were significantly different (0.05 < p < 0.001) from baseline and control group for groups A and B. Serum phosphorus levels significantly decreased by 22.54% for group A, 17.69% for group B and 7.71% for group D, compared with the baseline (0.05 < p < 0.001). From this study, we conclude that oral administration of gum arabic could conceivably alleviate adverse effects of CRF.