Dietary α-linolenic acid alters tissue fatty acid composition,but not blood lipids,lipoproteins or coagulation status in humans

We examined the effect of dietary α-linolenic acid (ALA) on the indices of lipid and coagulation status and on the fatty acid composition of serum and peripheral blood mononuclear cell (PBMNC) lipids in ten healthy men (age 21–37 yr) who consumed all their meals at the Western Human Nutrition Research Center for 126 d. There was a stabilization period of 14 d at the start when all 10 subjects consumed the basal diet (BD) containing 23.4 energy percent (en%) fat and two intervention periods of 56 d each. During the first intervention period, 5 subjects consumed the BD containing 23.4 en% fat, and 5 subjects consumed a diet providing 6.3% calories from α-linolenic acid [flaxseed oil (FSO) diet containing 28.8 en% fat]. Diets were crossed over between the two groups during the second intervention period. Feeding the FSO diet did not nignificantly alter serum triglycerides, cholesterol, highdensity lipoproteins, low-density lipoproteins, apoprotein A-I and apoprotein B when compared to the corresponding values in the subjects fed the BD, nor was there any effect of the FSO diet on the bleeding time, prothrombin time and partial prothrombin time for these subjects. Feeding the ALA-containing diet did cause a significant increase in ALA concentration in serum (P<0.001) and PBMNC lipids (P<0.05). It also caused a significant increase (P<0.05) in the eicosapentaenoic and docosapentaenoic acid contents of PBMNC lipids, and a decrease (P<0.01) in linoleic and eicosatrienoic acid contents of serum lipids. Thus, dietary ALA, fed for 56 d at 6.3% of calories, had no effect on plasma triglyceride or very low density lipoprotein levels or the common risk factors associated with atherosclerosis, although these parameters have been reported by others to be influenced by fatty acids, such as palmitic or linoleic acids, in the diet. Dietary ALA did significantly alter the fatty acid composition of plasma and PBMNC. The views expressed in the paper are those of the authors and do not reflect the official policy or position of the Department of Agriculture or Department of Defense, or the U.S. Government.     

Electrochemical Techniques for Corrosion Rate Determination in Ceramics

Standard electrochemical test procedures have been successfully applied to determine the corrosion rates of SiC-based ceramics in aqueous reagents. Direct-current polarization measurements in HCI solutions indicate that the corrosion rate of α-SiC is 0.0050 ± 0.0002 mil/yr and is fairly independent of HCI concentration. The corrosion rates of α-SiC are significantly lower than those for reaction-sintered SiC in all of the electrolytes used including HCI, HNO₃, H₃, H₃PO₄, and aqua regia. It is believed that the free Si contained in the reaction-sintered SiC is responsible for the higher corrosion rates. It has been shown that electrochemical techniques are reproducible and eminently suitable for determining very low corrosion rates encountered in ceramics.     

An experimental study of the flow of nonspherical grains in a rotating cylinder

The effect of particle aspect ratio on the rheology of the flow of granular materials is studied experimentally in a quasi–two‐dimensional rotating cylinder, using two varieties of prolate spheroidal grains with different aspect ratios. Image analysis of high speed videos is used to obtain the flow profiles near the centre of the cylinder. The dynamic angle of repose and apparent viscosity in the medium show significant increase with increasing aspect ratio. The mean velocity, root mean square velocity and shear rate profiles are qualitatively similar for nonspherical and spherical particles, however, their magnitudes increase with increasing aspect ratio. A simple scaling is shown to predict the maximum thickness of the flowing layer for all the particles. The predictions of a model for the flow match with the measured mean velocity profiles and layer thickness. © 2017 American Institute of Chemical Engineers AIChE J, 63: 4307–4315, 2017     

Effect of reaction parameters on the particle sizes of crosslinked spherical phenolic beads by suspension polymerization of phenol and formaldehyde

The crosslinked spherical phenolic beads (PB) were prepared with phenol and formaldehyde in alkaline medium by suspension polymerization technique. Poly(vinyl alcohol) (PVA) hexamethylenetetramine (HMTA), and triethylamine (TEA) were used as stabilizer, crosslinking agent, and basic catalyst respectively. The resulting PB with higher yield (82.5%) and relatively uniform particle size range (0.2–1.8 mm) were formed at 95–97°C, 550 rpm for 4 h, by using varied amounts of PVA as a stabilizer. The particle size and its distribution could be adjusted by selecting a suitable polymerization medium, consisting of monomer added to water, and by varying their relative amounts, mechanical agitation and stabilizer concentration. The yield % of PB was also varied with the concentration of stabilizer, agitation rate, and monomer‐to‐water ratio. The effects of concentration of the stabilizer, agitation rates, and monomer‐to‐water ratio on PB formation and morphology are described. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2323–2330, 2006     

Low-fat diets do not lower plasma cholesterol levels in healthy men compared to high-fat diets with similar fatty acid composition at constant caloric intake

In most studies reporting the effects of high-fat (HF) and low-fat (LF) diets on human plasma fatty acids (FA) and lipoprotein levels, the design involved adding to the diet an oil that had an FA composition (FAC) very different from the FAC of the control diet. Thus, it is difficult to determine if simply reducing the fat content of the diet without changing the dietary FAC changes the tissue FAC or alters plasma lipid levels. In this study, we fed diets that contained either 22 or 39% of calories from fat, but had no differences in their FAC, for 50 d to a group (n=11) of healthy men (20–35 y). Thus, the polyunsaturated/saturated ratios (1.0) of the diets were identical as were the n−3/n−6 ratio and the monounsaturated-to-total fat ratios. The diets contained (wt% of total fat) approximately 28% saturated FA, 33% monounsaturatedcis-FA, 6% monounsaturatedtrans-FA, 22% n−6 polyunsaturated FA, and 7% n−3 polyunsaturated FA, and 4% other minor FA. The diets consisted of natural foods and were formulated to contain 16 en% protein, either 45 or 62 en% carbohydrate (CHO) and at least the recommended dailyallowance for all micronutrients. Both diets contained 360 mg of cholesterol per day. All subjects were given the HF diet for 20 d, and then six were placed on the LF and the other five remained on the HF diet for 50 d. The two groups were crossedover for the remaining 50 d of the study. The subjects' baseline total cholesterol level was 173 mg/dl, after 50 d on the HF diet it was 177 mg/dl and after 50 d on the LF diet, 173 mg/dl. The differences were not significant, and there were no significant changes in either the LDL or HDL cholesterol levels with either diet. Triglyceride levels, and consequently very low density lipoprotein levels, rose significantly on the LF, higher CHO diet compared to the levels found in the subjects on the HF diet (91.5 and 66.4 mg/dl respectively,P<0.002). The linoleic acid content of the plasma, platelets, and red blood cells was significantly (P<0.05) reduced in the LF diet compared to HF diet, without any obvious physiological effects. Hence, many earlier observations indicating reductions in plasma lipid levels when people are on LF diets may be due to changes in the FAC of the diet, not the reduction in fat calories.     

Detection of adulteration by caprine body fat and mixtures of caprine body fat and groundnut oil in bovine and buffalo ghee using differential scanning calorimetry

Differential scanning calorimetry was used to detect adulteration of pure ghee with caprine body fat when added singly (at 5, 10 and 15%) and in combination with groundnut oil (GNO) (at 5, 10 and 15%). Samples were analysed for transition behaviour in terms of crystallising and melting curves. When compared to pure ghee, adulterated ghee samples showed a shift in the midrange temperature of thermal curves, indicating the presence of foreign fats. The results revealed that the detection of adulteration was possible at the lowest level of the study (5%), irrespective of the nature of the adulterants.     

Reduction of vanadium oxide by carbon in stainless steelmaking slags

Simultaneous reduction of chromium, iron and vanadium oxides by carbon has been studied by conducting experiments on typical stainless steelmaking slags in the temperature range of 1823 to 1923 K. In‐situ gas generated due to the reduction led to several phenomena such as foam/emulsion formation, change in foam height, size of gas bubbles and rate of gas generation. The kinetics of vanadium oxide reduction by carbon are studied under the influence of the above mentioned phenomena and the presence of chromium and iron oxides.     

Accretion of Dietary Docosahexaenoic Acid in Mouse Tissues Did Not Differ between Its Purified Phospholipid and Triacylglycerol Forms

Recent studies suggest that dietary krill oil leads to higher omega-3 polyunsaturated fatty acids (n-3 PUFA) tissue accretion compared to fish oil because the former is rich in n-3 PUFA esterified as phospholipids (PL), while n-3 PUFA in fish oil are primarily esterified as triacylglycerols (TAG). Tissue accretion of the same dietary concentrations of PL- and TAG-docosahexaenoic acid (22:6n-3) (DHA) has not been compared and was the focus of this study. Mice (n = 12/group) were fed either a control diet or one of six DHA (1%, 2%, or 4%) as PL-DHA or TAG-DHA diets for 4 weeks. Compared with the control, DHA concentration in liver, adipose tissue (AT), heart, and eye, but not brain, were significantly higher in mice consuming either PL- or TAG-DHA, but there was no difference in DHA concentration in all tissues between the PL- or TAG-DHA forms. Consumption of PL- and TAG-DHA at all concentrations significantly elevated eicosapentaenoic acid (20:5n-3) (EPA) in all tissues when compared with the control group, while docoshexapentaenoic acid (22:5n-6) (DPA) was significantly higher in all tissues except for the eye and heart. Both DHA forms lowered total omega-6 polyunsaturated fatty acids (n-6 PUFA) in all tissues and total monounsaturated fatty acids (MUFA) in the liver and AT; total saturated fatty acid (SFA) were lowered in the liver but elevated in the AT. An increase in the DHA dose, independent of DHA forms, significantly lowered n-6 PUFA and significantly elevated n-3 PUFA concentration in all tissues. Our results do not support the claim that the PL form of n-3 PUFA leads to higher n-3 PUFA tissue accretion than their TAG form.     

An empirical investigation into the validity of transitivity andnon-satiety assumptions in partial order structures: a note

Research in the area of information acquisition has been based on two key assumptions, namely, nonsatiety (implying more is preferable to less) and transitivity (implying that if A is preferred to B and B to C then A will be preferred to C). While at first glance these assumptions do not seem altogether unjustifiable, they do, in practice, constrain the empirical application of the research models. The primary purpose of the paper is to test the validity of these two key assumptions underlying most theoretical research in information acquisition and resource allocation. We begin by introducing four partial order structures and highlight the assumptions upon which they have been based. We then discuss how these structures could be used in estimating consumer preferences. We also provide a statistical methodology to implement such estimation. In later sections, we implement the empirical model on two data sets and discuss the results and propose generalizations