Consumption of reduced-fat products: effects on parameters of anti-oxidative capacity

Plasma levels of fibrinogen, factor VIIc and prothrombin fragment F1 + 2, a marker of thrombin generation in vivo, were studied in 68 subjects with serum total cholesterol (TC) levels between 135 and 349 mg/dl but without clinical evidence of cardiovascular disease and other atherosclerotic risk factors. F1 + 2 plasma levels were directly correlated with TC (p < 0.0004), low-density lipoprotein cholesterol (LDL-C; p < 0.0018) and factor VIIc (p < 0.024). Thirty-five subjects with TC greater than 249 mg/dl (median value of the whole group) showed higher levels of F1 + 2 (p < 0.0001) and fibrinogen (p < 0.0015) than those with TC lower than 249 mg/dl. In subjects with TC > 249 mg/dl and F1 + 2 > 1.2 nM (median value of the whole group), a cholesterol-lowering drug (simvastatin) was able to reduce F1 + 2 (p < 0.009) as well as TC and LDL-C. This study shows a relationship between serum cholesterol and the rate of thrombin generation supporting the hypothesis that a hypercoagulable state may occur in hypercholesterolemic subjects before the onset of clinical evidence of atherosclerotic cardiovascular disease.     

The clinical relevance of the Waterlow pressure sore risk scale in the ICU

OBJECTIVE: To evaluate whether the Waterlow pressure sore risk (PSR) scale has prognostic significance for intensive care patients. DESIGN: A prospective study. SETTING: The surgical intensive care unit (ICU) of the University Hospital Rotterdam. PATIENTS: Data were evaluated from 594 patients who had been admitted to the ICU during the year 1994. METHODS AND RESULTS: Each patient was assessed daily with respect to their Waterlow PSR score and the development of pressure sores in the sacral region. Actuarial statistical methods were used to analyse the predictive value of the risk score. When a patient had a Waterlow PSR score > 25 on admission, the risk of developing a pressure sore was significantly increased compared to patients with a PSR score < 25. After admission, the daily Waterlow PSR scores obtained were significantly associated with the risk of developing a pressure sore. For each additional point this risk increased by 23% (95% confidence interval 17 to 28%). CONCLUSIONS: The Waterlow PSR scale provides the medical and nursing staff at an early stage with reliable information about the risk patients have in developing a pressure sore.     

Long-term effects of nutrition with fat-reduced foods on energy consumption and body weight

In a 3-month intervention study 70 women (40 < age < 60; 24 < BMI < 29), randomized into two groups, were supplied ad libitum and free of charge with 1) customary fat-reduced foods (D group) or 2) products with normal fat content (K group). After 6 months without any contact to the volunteers food intake and body weight were controlled. Results: During the intervention period fat intake (by 22 g/d) and total energy intake (by 266 kcal/d) of the volunteers in the D group were significantly lower than in the K group. Fat reduction was not accompanied by a compensative increase in the intake of other nutrients. The weight loss was significant in the D group (1.5 kg) and not significant in the K group (0.7 kg). Between the two groups the difference in weight reduction was not significant. In the follow-up a lowered fat and energy intake had been voluntarily retained in the D group and adopted by most of the individuals in the K group. Conclusion: The consumption of low-fat products lowers the energy and fat intake and may be useful for a long-term weight control and health support.     

Volatilization of the pesticides chlorpyrifos and fenpropimorph from a potato crop

Volatilization of pesticides from crops in the field can be an important emission pathway. In a field experiment with characterization of meteorological conditions, the pesticides chlorpyrifos and fenpropimorph were sprayed onto a potato crop, after which concentrations in the air and on/in the plants were measured. Rates of volatilization were estimated with the aerodynamic profile (ADP), energy balance (EB), relaxed eddy accumulation (REA), and plume dispersion (PD) methods. The volatilization rates obtained with the ADP and EB methods were similar, while some rates obtained with the REA and PD methods in the initial period were lower. Cumulative volatilization of chlorpyrifos during daylight hours (ADP and EB methods) was estimated to be about 65% of the dosage. By far the majority of this volatilization occurred in the first few days. Competing processes at the plant surface had a considerable effect on the dissipation of fenpropimorph, so cumulative volatilization during daylight hours was estimated to be only 7% of the dosage. Plant surface residues were higher than would correspond with the volatilization rate, indicating that penetration into the leaves had occurred.     

Catalysis by Gold Nanoparticles

Gold catalysts have superior activity in CO and other oxidations at low temperatures. Both a small (~ 5nm) particle size and the presence of a partly reducible oxide (ceria or a transition metal oxide) have a beneficial effect on the catalyst performance. The present paper reviews our recent studies focused on understanding the specific role of the Au particle size and that of the oxide (MO). Our personal viewpoint on gold catalysis is outlined. The effects of Au particle size and of the oxidic additive are distinguished by using several alumina-supported gold catalysts having different gold particle sizes and various oxidic additives. The most active catalyst in CO oxidation is the multicomponent catalyst Au/MgO/MnOx/Al2O3 with MgO being a stabilizer for the Au particle size and MnOx being the cocatalyst. This catalyst also exhibits good performance in selective oxidation of CO in a hydrogen atmosphere, a reaction relevant for the development of polymer electrolyte fuel cell technology.     

Effects of margarine compared with those of butter on blood lipid profiles related to cardiovascular disease risk factors in normolipemic adults fed controlled diets

Effects of butter and 2 types of margarine on blood lipid and lipoprotein concentrations were compared in a controlled diet study with 23 men and 23 women. Table spreads, added to a common basal diet, provided 8.3% of energy as fat. Diets averaged 34.6% of energy as fat and 15.5% as protein. Each diet was fed for 5 wk in a 3 x 3 Latin-square design. One margarine (TFA-M) approximated the average trans monoene content of trans fatty acid-containing margarines in the United States (17% trans fatty acids by dry wt). The other margarine (PUFA-M) was free of trans unsaturated fatty acids; it contained approximately twice the polyunsaturated fatty acid content of TFA-M (49% compared with 27% polyunsaturated fatty acids). The tub-type margarines had similar physical properties at ambient temperature. Fasting blood lipids and lipoproteins were determined in 2 samples taken from the subjects during the fifth week of each dietary treatment. Compared with butter, total cholesterol was 3.5% lower (P=0.009) after consumption of TFA-M and 5.4% lower (P< 0.001) after consumption of PUFA-M. Similarly, LDL cholesterol was 4.9% lower (P=0.005) and 6.7% lower (P< 0.001) after consumption of TFA-M and PUFA-M, respectively. Neither margarine differed from butter in its effect on HDL cholesterol or triacylglycerols. Thus, consumption of TFA-M or PUFA-M improved blood lipid profiles for the major lipoproteins associated with cardiovascular risk when compared with butter, with a greater improvement with PUFA-M than with TFA-M.     

Deposition of HfO2 on InAs by atomic-layer deposition

Metal–oxide–semiconductor (MOS) capacitors are formed on bulk InAs substrates by atomic-layer deposition (ALD) of HfO₂. Prior to film growth, InAs substrates receive a wet-chemical treatment of HCl, buffered HF (BHF), or (NH₄)₂S. Hafnium dioxide films are grown using 75 ALD cycles with substrate temperatures of 100, 200, and 300 °C. Substrate temperature is found to have a significant influence on the current–voltage (I–V) and capacitance–voltage (C–V) characteristics of the capacitors, while the influence of substrate pretreatment manifests itself in interface trap density, D_it, as measured by the Terman method.     

Fat substitution and food intake: effect of replacing fat with sucrose polyester at lunch or evening meals

The objective of the present study was to determine the effect of replacement of fat by sucrose polyester (SPE) within a lunch or evening meal on subsequent energy intake and appetite control. The 2 x 2 design was intended to examine the effect on appetite of reducing the total energy and fat content of a meal (lunch or dinner) by replacement of natural fat with 55 g SPE. The effects were monitored by measuring motivation to eat or actual food consumption during the remainder of the test day (day 1) and throughout the following day (day 2). The 2 x 2 design yielded four conditions which were a control meal (5192 kJ, 73.2 g fat) and a fat-replaced meal (3305 kJ, 54.6 g SPE, 24 g fat) at midday (lunch) or in the early evening (dinner). No significant differences were seen in ad lib. energy intake after the test meals on day 1 or day 2. Certain differences were detected in fat intake on day 2 but these did not suggest nutrient compensation in response to the fat replacement. Subjective assessment of motivation to eat did not indicate that the fat-reduced meal had a weaker satiating efficiency than the control meal. A reduction in fat content, using fat replacement, did not reduce the satiating efficiency of a test meal given at lunch or dinner. No energy or macronutrient compensation occurred following the reduction in energy or fat intake during the rest of the test day or during the whole of the next day.     

The association of increasing dietary concentrations of fish oil with hepatotoxic effects and a higher degree of aorta atherosclerosis in the ad lib.-fed rabbit

The long-term effects of consumption of marine long-chain n-3 polyunsaturated fatty acids (PUFA) on atherosclerosis in the rabbit were examined. Female Dutch rabbits were fed purified diets, containing 40 energy% total fat, for a period of 2.5 years. To study the dose response relationship between fish oil intake and atherosclerosis, four diets were formulated with fish oil levels being 0, 1, 10 and 20 energy%. A fifth and sixth group were fed an alpha-linolenic acid-(C18:3, n-3) and linoleic acid-(C18:2, n-6) rich diet, respectively. Every 6 weeks, blood samples were taken for determination of clinical chemical parameters, triacylglycerol and total cholesterol levels. Feeding 10 and 20 energy% fish oil containing diets, resulted in an increase of liver enzymes (AST, ALT and ALP). Histological evaluation of the liver also revealed adverse effects of fish oil containing diets. Triacylglycerol blood levels were similar in all groups, and remained constant throughout the study. Total cholesterol levels in blood was significantly lower in the animals fed a linoleic acid-rich diet, as compared with the other five groups. An n-3 long-chain PUFA concentration dependent increase in aorta plaque surface area was observed in the fish oil groups. A significant positive relationship was found between the group mean score for severity of liver pathology and the aorta plaque surface area. These results indicate that the long-chain n-3 polyunsaturated fatty acids in fish oil may be hepatotoxic to the herbivorous rabbit, which may interfere with the outcome of atherosclerosis studies. This finding necessitates the exclusion of liver pathology in experimental studies on atherosclerosis in animal models.     

Sensitivity of narrow- and wideband LNA performance to individual transistor model parameters

Although it is desirable for a transistor model to be as accurate as possible, the extraction of model parameters from fabricated transistors is a time-consuming and often costly process. An investigation of the sensitivity of low-noise amplifier (LNA) performance characteristics to individual parameters of the physics-based standard HBT model HICUM/L2 was, therefore, done to gain a preliminary insight into the most important parameters for transistors used in actual circuits. This can potentially allow less strenuous accuracy requirements on some parameters which would ease the extraction process. Both a narrow- and wideband LNA configuration were investigated. It was found that the series resistance parameters have a large impact on LNA gain, S ₁₁ and noise figure performance in both cases. Since the narrow-band LNA relied heavily on the transistor characteristics to provide a proper matching, it was also very sensitive to changes in the parameters used in modelling the high-frequency current gain and depletion capacitances of the transistor.