Autistic Children Exhibit Decreased Levels of Essential Fatty Acids in Red Blood Cells

Omega-6 (n-6) and omega-3 (n-3) polyunsaturated fatty acids (PUFA) are essential nutrients for brain development and function. However, whether or not the levels of these fatty acids are altered in individuals with autism remains debatable. In this study, we compared the fatty acid contents between 121 autistic patients and 110 non-autistic, non-developmentally delayed controls, aged 3–17. Analysis of the fatty acid composition of red blood cell (RBC) membrane phospholipids showed that the percentage of total PUFA was lower in autistic patients than in controls; levels of n-6 arachidonic acid (AA) and n-3 docosahexaenoic acid (DHA) were particularly decreased (p < 0.001). In addition, plasma levels of the pro-inflammatory AA metabolite prostaglandin E2 (PGE2) were higher in a subset of the autistic participants (n = 20) compared to controls. Our study demonstrates an alteration in the PUFA profile and increased production of a PUFA-derived metabolite in autistic patients, supporting the hypothesis that abnormal lipid metabolism is implicated in autism.     

Evidence for two-dimensional solitary sound waves in a lipid controlled interface and its implications for biological signalling

Biological membranes by virtue of their elastic properties should be capable of propagating localized perturbations analogous to sound waves. However, the existence and the possible role of such waves in communication in biology remain unexplored. Here, we report the first observations of two-dimensional solitary elastic pulses in lipid interfaces, excited mechanically and detected by FRET. We demonstrate that the nonlinearity near a maximum in the susceptibility of the lipid monolayer results in solitary pulses that also have a threshold for excitation. These experiments clearly demonstrate that the state of the interface regulates the propagation of pulses both qualitatively and quantitatively. Finally, we elaborate on the striking similarity of the observed phenomenon to nerve pulse propagation and a thermodynamic basis of cell signalling in general.     

Effects of light quality on the accumulation of oil in a mixed culture of Chlorella sp. and Saccharomyces cerevisiae

BACKGROUND: Chlorella strains rather than terrestrial oil crops having higher oil content and shorter generation time have been considered as promising candidates for alternative biodiesel. Since the influence of light quality on oil formation of microalgae in either monoculture or mixed culture has been shown to be either inconsistent or ambiguous, a light‐emitting diode (LED) photo‐bioreactor with different light sources and intensities was used in this study to investigate a cost‐effective lipid production process. RESULTS: The oil accumulation in a mixed culture of Chlorella sp. and Saccharomyces cerevisiae was higher than that in the monoculture under the different light sources used. Results of the influence of light quality on the mixed culture indicated that the optimal light wavelength and intensity for biomass formation was red LED light at 1000 lux, whereas the optimum for oil formation was blue LED light at 1000 lux. A novel two‐stage LED photo‐bioreactor was thus proposed and the highest P_max and productivity in this study were obtained as 261 mg L^?1 and 8.16 mg L^?1 h^?1, respectively. CONCLUSION: A novel two‐stage LED photo‐bioreactor using a mixed culture to optimize microalgal oil production was proposed and successfully demonstrated in this study. Copyright © 2011 Society of Chemical Industry     

求解多尖角区域的声波散射问题的一种方法

受Kress变换启发，得到N个尖角的公式，并利用N个尖角的公式、位势理论和Nys—trom方法求解多尖角区域的声波散射问题．并给出两个数值例子，计算结果表明该方法的可行性和有效性．     

Effectiveness of ethanolic galangal extract (Alpinia galanga Linn.) on inhibition of lipid oxidation in fish muscle systems

Effectiveness of ethanolic galangal extract as an antioxidant in fish mince and fillet was investigated. The extract (5.8 μm gallic acid equivalent; GAE) reduced deoxygenation of sea bass haemoglobin (Lates calcarifer) at pH 6.5. The lag time for TBARs development in washed sea bass mince mediated by the haemoglobin at pH 6.5 was extended from 2 to 8 days by added galangal extract (0.02% w/w GAE). Washing the sea bass fillet with low preformed lipid hydroperoxide (LHP) content by galangal extract solution (0.2% w/v GAE) effectively inhibited the TBARs formation throughout the storage. However, in the longtail tuna fillet (Thunnus tonggol) having a significant content of preformed LHP, there was nonsignificant difference in the reaction lag time of the samples washed with the solution and with water. Thus, galangal extract can be used as an antioxidant in fish if its application is performed before initiation of lipid oxidation.     

Industrial validation of fourier transform infrared trans and lodine value analyses of fats and oils

A Fourier transform infrared (FTIR) edible oil analysis package designed to simultaneously analyze for trans content, cis content, iodine value (IV), and saponification number (SN) of neat fats and oils by using calibrations based on pure triglycerides and derived by application of partial-least-squares (PLS) regression was assessed and validated. More than 100 hydrogenated rapeseed and soybean samples were analyzed by using the edible oil analysis package as well as the newly proposed modification of the AOCS IR trans method with trielaidin in a trans-free oil as a basis for calibration. In addition, ∼1/3 of the samples were subsequently reanalyzed by gas chromatography (GC) for IV and trans content. The PLS approach predicted somewhat higher trans values than the modified AOCS IR method, which was traced to a combination of the inclusion of trilinolelaidin in the calibration set and the effects of baseline fluctuations. Eliminating trilinolelaidin from the triglyceride standards and the use of second-derivative spectra to remove baseline fluctuations produced excellent concurrence between the PLS and modified AOCS IR methods (mean difference of 0.61% trans). Excellent internal consistency was obtained between the IV and cis and trans data provided by the edible oil analysis package, and the relationship was close to that theoretically expected [IV=0.86 (cis + trans)]. The IV data calculated for the GC-analyzed samples matched the PLS IV predictions within 1 IV unit. The trans results obtained by both IR methods were linearly related to the GC data; however, as is commonly observed, the GC values were significantly lower than the IR values, the GC and IR data being related by a slope factor of ∼0.88, with an SD of ∼0.80. The concurrence between the trans data obtained by the two FTIR methods, and between the FTIR and GC-IV data, as well as the internal consistency of the IV, cis and trans FTIR predictions, provides strong experimental evidence that the edible oil analytical package measures all three variables accurately. Co-Director, McGill IR Group.     

Enhancement of arachidonic acid production by Mortierella alpina 1S-4

The effect of mineral addition on arachidonic acid (AA) production by Mortierella alpina 1S-4 was evaluated. At first, the addition of minerals such as sodium, potassium, calcium, and magnesium was examined in flask cultures, and then the addition of phosphorus with the optimal amounts of the minerals was investigated in a 10-L jar-fermenter. As a result, 1.5% soy flour medium with the addition of 0.3% KH₂PO₄, 0.1% Na₂SO₄, 0.05% CaCl₂·2H₂O, and 0.05% MgCl₂·6H₂O was found to enhance the AA yield 1.7-fold over that without mineral addition. When 1% yeast extract with the above mineral mixture was used, the AA yield was enhanced 1.35-fold over that without minerals. We also verified that an increase in the polar lipid content occurred in the case of only KH₂PO₄ addition, and that the above-mentioned increase in the AA yield was due to the minerals themselves, not a pH buffer effect.