Lipidomic Analysis of Plasma from Healthy Men and Women Shows Phospholipid Class and Molecular Species Differences between Sexes

The phospholipid composition of lipoproteins is determined by the specificity of hepatic phospholipid biosynthesis. Plasma phospholipid 20:4n-6 and 22:6n-3 concentrations are higher in women than in men. We used this sex difference in a lipidomics analysis of the impact of endocrine factors on the phospholipid class and molecular species composition of fasting plasma from young men and women. Diester species predominated in all lipid classes measured. 20/54 Phosphatidylcholine (PtdCho) species were alkyl ester, 15/48 phosphatidylethanolamine (PtdEtn) species were alkyl ester, and 12/48 PtdEtn species were alkenyl ester. There were no significant differences between sexes in the proportions of alkyl PtdCho species. The proportion of alkyl ester PtdEtn species was greater in women than men, while the proportion of alkenyl ester PtdEtn species was greater in men than women. None of the phosphatidylinositol (PtdIns) or phosphatidylserine (PtdSer) molecular species contained ether-linked fatty acids. The proportion of PtdCho16:0_22:6, and the proportions of PtdEtn O-16:0_20:4 and PtdEtn O-18:2_20:4 were greater in women than men. There were no sex differences in PtdIns and PtdSer molecular species compositions. These findings show that plasma phospholipids can be modified by sex. Such differences in lipoprotein phospholipid composition could contribute to sexual dimorphism in patterns of health and disease.     

The coagulation of a kaolinite suspension with aluminium sulphate

A study has been made of the coagulation of a 50 mg l⁻¹ aqueous suspension of kaolinite for a range of aluminium sulphate and hydrogen ion concentrations. The rate of flocculation was determined from jar tests after stirring for 1 h. The data permitted a stability limit diagram to be drawn from which some indication of the coagulation mechanisms of the system could be ascertained.     

Compositional heterogeneity may limit the usefulness of some commercial naphthenic acids for toxicity assays

Naphthenic acids are considered variously as monocarboxylic acids fitting the formula C_nH_2n + zO₂ (where z is a zero or negative even integer), as only alicyclic (i.e. non-aromatic) monocarboxylic acids fitting this formula (z ≤ 0), or simply as those carboxylic acids occurring in petroleum products or crude oils that have been formed through biodegradation of hydrocarbons. Such acids are known constituents of the process-affected water associated with some expanding oil sands industries, of some immature and biodegraded crude oils, of produced water discharges from oil production platforms and are used as biocides and as components in the manufacture of steel radial tyres.As a result of these potential vectors of the acids into the environment, various naphthenic acid mixtures which are available commercially have been used for a range of toxicity studies. However, as some manufacturers make clear, but which is not often emphasised in the toxicity studies, a range of different quality naphthenic acids is produced commercially. It has been suggested previously, and we showed recently and elucidate further herein, that such commercial mixtures therefore sometimes contain toxic components other than carboxylic acids. For example, we identify herein by two-dimensional comprehensive gas chromatography-mass spectrometry, a range of C_0-6 alkylphenols in a batch of commercial naphthenic acids. Since these compounds are known toxicants, the contribution of such non-carboxylic acids, if any, to the toxicity attributed previously to the acids, should also be considered. This will be reflected in the concentrations and effective toxicities of such components. In order to establish the toxicity of the acids per se, assays of pure synthetic carboxylic acids of the type now known to be present in naphthenic acids from petroleum or oil sands may be more appropriate than tests of the toxicity of largely unknown, heterogeneous, mixtures.     

Improved phase stability and electrochemical performance of (Y,In,Ca)BaCo3ZnO7+δ cathodes for intermediate temperature solid oxide fuel cells

With an aim to combine the performance-enhancing properties of Ca with the stability-promoting properties of In in the swedenborgite YBaCo₄O_7+δ-based cathodes for solid oxide fuel cells (SOFC), cation-substituted Y_1−x−yIn_xCa_yBaCo₃ZnO_7+δ (0.2 ≤ (x + y) ≤ 0.5) oxides have been explored. All samples presented in this work are stable in air after 120 h exposure to 600, 700, and 800 °C. Increasing In content shows a negligible impact on polarization resistances (R_p), but causes an increase in the activation energies (E_a) of (Y,In,Ca)BaCo₃ZnO_7+δ + Gd_0.2Ce_0.8O_1.9 (GDC) composite cathodes on 8 mol% yttria-stabilized zirconia (8YSZ) electrolyte supported symmetric cells. Increasing Ca content shows a decrease in R_p and an increase in E_a on similar electrochemical cells. All (Y,In,Ca)BaCo₃ZnO_7+δ samples investigated here show superior performance compared to the unsubstituted YBaCo₃ZnO_7+δ + GDC cathode in the range of 400–800 °C. Especially, the Y_0.5In_0.1Ca_0.4BaCo₃ZnO_7+δ + GDC composite cathode exhibits good performance on GDC electrolytes in the range of 400–600 °C. With superior phase stability and electrochemical performance, the (Y,In,Ca)BaCo₃ZnO_7+δ series of oxides are attractive cathode candidates for intermediate temperature SOFCs.     

Electrochemical detection of 14 common munitions constituents

Electrochemical detections of 14 munitions constituents (MCs) listed on the Environmental Protection Agency hazardous waste list were examined using square wave voltammetry. Of the MCs that showed peak resolution in the scanned range, the reduction potential, limit of detection and limit of quantitation are reported here. The MCs tested are in three groups: nitrobenzenes, nitrotoluenes, and other nitro-aromatics: tetryl, HMX, and RDX. There was a correlation between peak resolution and the number of nitro groups for the nitrobenzenes and nitrotoluenes. The nitro group distance from the methyl for the nitrotoluenes with two nitro groups showed some correlation to the ability to detect as well. Some mixture experiments were conducted in which MCs with three and two nitro groups were detected simultaneously. While tetryl readily displayed two peaks, RDX and HMX did not show such clear peak resolution.     

An analytical method for the analysis of trihalomethanes in ambient air using solid‐phase microextraction gas chromatography‐mass spectrometry: An application to indoor swimming pool complexes

A simple method for the collection and analysis of the four brominated and chlorinated trihalomethanes (THMs) in air samples is described. Ambient air samples were collected in pre‐prepared glass vials, with THM analysis performed using solid‐phase microextraction gas chromatography‐mass spectrometry, where the need for chemical reagents is minimized. Analytical parameters, including oven temperature program, solvent volume, incubation time, vial agitation, extraction time and temperature, as well as desorption time and temperature, were evaluated to ensure optimal method performance. The developed method allows for point‐in‐time quantification (compared to an average concentration measured over extended periods of time), with detection limits between 0.7 to 2.6 µg/m³. Excellent linearity (r² > 0.99), repeatability (3% to 11% RSD), and reproducibility (3% to 16% RSD) were demonstrated over a concentration range from 2 to 5000 µg/m³. The method was validated for the analysis of THMs in indoor swimming pool air and was used to investigate the occurrence of THMs in the air above 15 indoor swimming pools. This is the first study to report the occurrence of THMs in swimming pool air in Australia, and concentrations higher than those previously reported in other countries were measured.     

Output Characteristics of an Optical Fibre Ring Resonator Using a Planar or Nonplanar 3 × 3 Fibre Coupler: A Comparison

Abstract

A comparison is made between the output characteristics of type 1 optical fibre ring resonators with a different type of 3 × 3 fibre coupler, that is a planar or a nonplanar coupler. Three different nonplanar couplers are formed when the central fibre 1 of a loosely coupled planar 3 × 3 fibre coupler is displaced normally from the common plane. Such a 3 × 3 fibre coupler can be identified by the value of its relative coupling ratio m ₃. The dependence of the output intensities of the ring resonator on the coupling length kd and the relative coupling ratio m ₃ of the 3 × 3 fibre coupler is investigated. The former dependence can be used as a guide to obtain suitable output characteristics of a fibre ring resonator for a specific application, while the latter can be used to choose the right type of 3 × 3 fibre coupler to build a fibre ring resonator. It is found that the output characteristics of a fibre ring resonator with a 3 × 3 planar (m ₃ = 0) or an equilateral triangular (m ₃ = 1) fibre coupler are usually better than those of the others.     

An improved hybrid classifier

Abstract. A new hybrid classifier is proposed which utilizes the advantages of the maximum likelihood classifier and the parallelepiped classifier. The new hybrid classifier reduces the processing time more substantially than the conventional one by introducing a lower boundary for each class. The rate of misclassification is comparable to that of maximum likelihood classifier. Performance of the conventional and the new method are compared by an example.     

A role for whey-derived lactoferrin and immunoglobulins in the attenuation of obesity-related inflammation and disease

Obesity is a strong predictive factor in the development of chronic disease and has now superseded undernutrition as a major public health issue. Chronic inflammation is one mechanism thought to link excess body weight with disease. Increasingly, the gut and its extensive population of commensal microflora are recognized as playing an important role in the development of obesity-related chronic inflammation. Obesity and a high fat diet are associated with altered commensal microbial communities and increased intestinal permeability which contributes to systemic inflammation as a result of the translocation of lipopolysaccharide into the circulation and metabolic endotoxemia. Various milk proteins are showing promise in the prevention and treatment of obesity and chronic low-grade inflammation via reductions in visceral fat, neutralization of bacteria at the mucosa and reduced intestinal permeability. In this review, we focus on evidence supporting the potential antiobesogenic and anti-inflammatory effects of bovine whey-derived lactoferrin and immunoglobulins.     

水冷和风冷型喷油螺杆空压机能效规定值的比较分析

将能效标准规定的水冷和风冷螺杆空压机的能效值绘制成曲线,进行取值的变化趋势分析;将水冷输入比功率和风冷输入比功率进行差值对比分析,提出能效标准规定值的欠合理内容,目的在于实现标准取值的合理化。