A randomized comparison of two weight-reducing diets. Calorie counting versus low-fat carbohydrate-rich ad libitum diet

We compared the importance of rate of initial weight loss for long term outcome in obese patients and the efficacy of two different dietary weight maintenance programmes. An initial weight loss of 12.6 kg was achieved either by eight weeks low energy diet (2 MJ/day) (n = 21) or 17 weeks conventional hypocaloric, high protein diet (5 MJ/day) (n = 22) both supported by an anorectic compound (ephedrine 20 mg and caffeine 200 mg thrice daily). Weight loss rate had no effect on long-term weight maintenance. Randomisation to one year weight maintenance of either an ad lib, low fat, high carbohydrate diet or a fixed energy diet (< 8 MJ/day), both supported by reinforcement sessions 2-3 times monthly, resulted in a maintenance of 13.2 of initial 13.5 kg weight loss in the ad lib group versus 9.7 of 13.8 kg in the fixed energy intake group. At follow-up two years after the initial weight loss, 65% of the ad lib group and only 40% of the fixed energy intake group had maintained a weight loss of > 5 kg.     

Tomato lycopene and low density lipoprotein oxidation: a human dietary intervention study

Increase in low density lipoprotein (LDL) oxidation is hypothesized to be causally associated with increasing risk of atherosclerosis and coronary heart disease. In recent epidemiological studies, tissue and serum levels of lycopene, a carotenoid available from tomatoes, have been found to be inversely related to risk of coronary heart disease. A study was undertaken to investigate the effect of dietary supplementation of lycopene on LDL oxidation in 19 healthy human subjects. Dietary lycopene was provided using tomato juice, spaghetti sauce, and tomato oleoresin for a period of 1 wk each. Blood samples were collected at the end of each treatment. Serum lycopene was extracted and measured by high-performance liquid chromatography using an absorbance detector. Serum LDL was isolated by precipitation with buffered heparin, and thiobarbituric acid-reactive substances (TBARS) and conjugated dienes (CD) were measured to estimate LDL oxidation. Both methods, to measure LDL oxidation LDL-TBARS and LDL-CD, were in good agreement with each other. Dietary supplementation of lycopene significantly increased serum lycopene levels by at least twofold. Although there was no change in serum cholesterol levels (total, LDL, or high-density lipoprotein), serum lipid peroxidation and LDL oxidation were significantly decreased. These results may have relevance for decreasing the risk for coronary heart disease.     

Domain structure analysis of elongation factor-3 from Saccharomyces cerevisiae by limited proteolysis and differential scanning calorimetry

Elongation-factor-3 (EF-3) is an essential factor of the fungal protein synthesis machinery. In this communication the structure of EF-3 from Saccharomyces cerevisiae is characterized by differential scanning calorimetry (DSC), ultracentrifugation, and limited tryptic digestion. DSC shows a major transition at a relatively low temperature of 39 degrees C, and a minor transition at 58 degrees C. Ultracentrifugation shows that EF-3 is a monomer; thus, these transitions could not reflect the unfolding or dissociation of a multimeric structure. EF-3 forms small aggregates, however, when incubated at room temperature for an extended period of time. Limited proteolysis of EF-3 with trypsin produced the first cleavage at the N-side of Gln775, generating a 90-kDa N-terminal fragment and a 33-kDa C-terminal fragment. The N-terminal fragment slowly undergoes further digestion generating two major bands, one at approximately 75 kDa and the other at approximately 55 kDa. The latter was unusually resistant to further tryptic digestion. The 33-kDa C-terminal fragment was highly sensitive to tryptic digestion. A 30-min tryptic digest showed that the N-terminal 60% of EF-3 was relatively inaccessible to trypsin, whereas the C-terminal 40% was readily digested. These results suggest a tight structure of the N-terminus, which may give rise to the 58 degrees C transition, and a loose structure of the C-terminus, giving rise to the 39 degrees C transition. Three potentially functional domains of the protein were relatively resistant to proteolysis: the supposed S5-homologous domain (Lys102-Ile368), the N-terminal ATP-binding cassette (Gly463-Lys622), and the aminoacyl-tRNA-synthase homologous domain (Glu820-Gly865). Both the basal and ribosome-stimulated ATPase activities were inactivated by trypsin, but the ribosome-stimulated activity was inactivated faster.     

Effect of bilateral filtration on fractal estimation of optical images of loaded material surfaces

The influence of adaptive bilateral filtration on the calculation of the fractal dimension of optical images is estimated. Filtration parameters are chosen on the basis of various criteria. The use of the maximum dispersion of the probability as the most effective parameter of estimating the image filtration quality is considered.     

Modification of the structure of powder coatings on nickel and chromium-nickel bases by introducing nanoparticles of titanium diboride during electron-beam welding

Composite materials and coatings that contain titanium diboride in a metal host are widely used with the purpose of fabricating high-strength heat-resistant materials. Due to high hardness as well as heat and corrosion resistance, titanium diboride is a promising compound for use as a wear-resistant component of the composition “metal host-TiB₂.” The structure and mechanical properties of compositions TiB₂-PG-10N-01 and TiB₂-PKh20N80, which were obtained by a three-stage method involving the preliminary mechanical treatment of mixtures of elemental powders, the self-propagating high-temperature synthesis (SHS) reaction initiated in the activated mixture, and the subsequent mechanical treatment of the product of the SHS reaction, are investigated. To form the coatings, the method of electron-beam welding is applied.     

Wear of steel with ultrasound-induced nanostructuring of the surface layer. Part 1. Mechanical properties and wear resistance

The structural modification and change of wear resistance on friction with boundary lubrication is considered for 110Γ13 steel with and without impact ultrasound treatment. The deformational relief formed on the lateral surface of the samples in compression and in frictional loading is found to be the same. On that basis, the factors responsible for the change in wear resistance are discussed.