Dietary intake of essential and long-chain polyunsaturated fatty acids in pregnancy

The dietary intake of EFA and long-chain PUFA (LCPUFA) by women with (n=14) and without (n=31) gestational diabetes mellitus (GDM) was determined by repeated 24-h recalls. Women with GDM consumed significantly more energy as fat compared with women who had uncomplicated pregnancies; absolute dietary fat did not differ. Dietary n−3 LCPUFA was substantially lower than the current recommendation for pregnancy, whereas intake of saturated FA (SFA) exceeded it. We conclude that replacing dietary sources of SFA with those of EFA and LCPUFA, especially n−3 LCPUFA, would benefit the dietary fat profiles of all pregnant women.     

Effect of nanocellulose fibers and acetylated nanocellulose fibers on properties of poly(ethylene‐co‐vinyl acetate) foams

Cellulose nanofibers are promising materials in the development of polymeric foams, because they act as heterogeneous nucleation sites for the growth of cells during foaming. In this research, we studied the incorporation of cellulose nanoparticles in poly(ethylene‐co‐vinyl acetate)‐EVA foams. The foams were produced with different fiber contents. We observed the effect of a chemical treatment by acetylation on the cellulose fibber, that is, we evaluated the use of hydrophilic and hydrophobic cellulose nanofibers in EVA foams. The main results indicate that with the addition of only 1% of cellulose nanofibers, cell density significantly reduces when compared with the pure EVA foams. On the other hand, by increasing the cellulose content, the agglomeration of nanofibers also increases, which results in heterogeneous cell sizes. The same phenomenon was observed in the foams produced with acetylated cellulose nanofibers, regardless of the fiber content used. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44760.     

Correlating Molecular Structure to the Behavior of Linear Styrene–Butadiene Viscosity Modifiers

The effect of linear styrene–butadiene polymer structure on the temperature–viscosity behavior of model polymer-base oil solutions is investigated using molecular dynamics simulations. Simulations of alternating, random, and block styrene–butadiene polymers in a dodecane solvent are used to calculate viscosity at 40 and 100 °C, reference temperatures for characterizing their function as viscosity modifiers. Mechanisms underlying this function are explored by quantifying the radius of gyration and intramolecular interactions of the polymers at the same reference temperatures. The block styrene–butadiene configuration exhibits the least change in viscosity with temperature, characteristic of a good viscosity modifier or viscosity index improver, and the behavior is correlated to the ability of this structure to form smaller coils with more intramolecular interactions at lower temperatures and then expand as temperature is increased. The results indicate that there is a correlation between styrene–butadiene polymer structure, additive function, and the mechanisms underlying that function.     

Effects of molybdenum on the pitting of ferritic- and austenitic-stainless steels in bromide and chloride solutions

The effect of Mo on the pitting potential, dissolution kinetics, and repassivation behavior of high purity ferritic stainless steels, Fe-18%Cr-x%Mo, and austenitic stainless steels, Fe-18%Cr-12-15%Ni-x%Mo, was studied in solutions of bromide and of chloride. Large increases in the pitting potential of Fe-18%Cr-x%Mo in chloride solution were found with increasing Mo content, compared with the distinctly smaller increases in bromide solution. There was an excellent correlation between the increase in pitting potentials of ferritic alloys between Fe-18%Cr-2% and 5%Mo in the chloride and bromide solutions with the increased dissolution overvoltages in the saturated solution of dissolved products within artificial pits. Austenitic stainless steels also showed larger increases in pitting potential in chloride solution than in bromide solution. Higher pitting potentials were recorded for the austenitic than the ferrite steels with the same Mo content. For austenitic steels, the pitting potentials in bromide and chloride solutions were not attributable solely to the difference in dissolution rates or repassivation characteristics in saturated solution of the dissolved products. It was concluded that initiation processes play an important role in the pitting of austenitic stainless steels.     

Discovery of Adamantyl Ethanone Derivatives as Potent 11β‐Hydroxysteroid Dehydrogenase Type 1 (11β‐HSD1) Inhibitors

11β‐Hydroxysteroid dehydrogenases (11β‐HSDs) are key enzymes regulating the pre‐receptor metabolism of glucocorticoid hormones. The modulation of 11β‐HSD type 1 activity with selective inhibitors has beneficial effects on various conditions including insulin resistance, dyslipidemia and obesity. Inhibition of tissue‐specific glucocorticoid action by regulating 11β‐HSD1 constitutes a promising treatment for metabolic and cardiovascular diseases. A series of novel adamantyl ethanone compounds was identified as potent inhibitors of human 11β‐HSD1. The most active compounds identified ( 52 , 62 , 72 , 92 , 103 and 104 ) display potent inhibition of 11β‐HSD1 with IC₅₀ values in the 50–70 nM range. Compound 72 also proved to be metabolically stable when incubated with human liver microsomes. Furthermore, compound 72 showed very weak inhibitory activity for human cytochrome P450 enzymes and is therefore a candidate for in vivo studies. Comparison of the publicly available X‐ray crystal structures of human 11β‐HSD1 led to docking studies of the potent compounds, revealing how these molecules may interact with the enzyme and cofactor.     

Decreasing the Linoleic Acid to α-Linolenic Acid Diet Ratio Increases Eicosapentaenoic Acid in Erythrocytes in Adults

The n-6/n-3 fatty acid (FA) ratio has increased in the Western-style diet to ~10–15:1 during the last century, which may have contributed to the rise in cardiovascular disease (CVD). Prior studies have evaluated the effects on CVD risk factors of manipulating the levels of n-6 and n-3 FA using food and supplements or investigated the metabolic fate of linoleic acid (LNA) and α-linolenic acid (ALA) by varying the n-6/n-3 ratios. However, no previous studies have investigated the potential interaction between diet ratios and supplementation with eicosapentaenoic acid (EPA, 20:5n-3) and docosahexaenoic acid (DHA, 22:6n-3). We used a factorial design approach with adults (n = 24) in a controlled feeding trial to compare the accretion of EPA and DHA into red blood cell membranes (RBC) by adding a direct source (algal oil supplement) of EPA and DHA in a diet with a 10:1 versus 2:1 ratio of n-6/n-3 FA. Subjects were randomized into 8-week crossover diet sequences and each subject consumed three of four diets [10:1, 10:1 plus supplement (10:1 + S), 2:1 and 2:1 + S]. LNA and ALA intakes were 9.4 and 7.7%, and 1.0 and 3.0% during the low and high ALA diets, respectively. Compared to the Western-style 10:1 diet, the 2:1 diet increased EPA by 60% (P < 0.0001) in RBC membranes without the direct EPA source and a 34% increase (P = 0.027) was observed with the 10:1 + S diet; however, DHA levels increased in both diet ratios only with a direct DHA source. Shifting towards a 2:1 diet is a valid alternative to taking EPA-containing supplements.     

Novel Bacterial Production of Two Different Bioactive Forms of Human Stem-Cell Factor

Human stem-cell factor (hSCF) stimulates the survival, proliferation, and differentiation of hematopoietic cells by binding to the c-Kit receptor. Various applications of hSCF require the efficient and reliable production of hSCF. hSCF exists in three forms: as two membrane-spanning proteins hSCF248 and hSCF229 and truncated soluble N-terminal protein hSCF164. hSCF164 is known to be insoluble when expressed in Escherichia coli cytoplasm, requiring a complex refolding procedure. The activity of hSCF248 has never been studied. Here, we investigated novel production methods for recombinant hSCF164 and hSCF248 without the refolding process. To increase the solubility of hSCF164, maltose-binding protein (MBP) and protein disulfide isomerase b’a’ domain (PDIb’a’) tags were attached to the N-terminus of hSCF164. These fusion proteins were overexpressed in soluble form in the Origami 2(DE3) E. coli strain. These solubilization effects were enhanced at a low temperature. His-hSCF248, the poly-His tagged form of hSCF248, was expressed in a highly soluble form without a solubilization tag protein, which was unexpected because His-hSCF248 contains a transmembrane domain. hSCF164 was purified using affinity and ion-exchange chromatography, and His-hSCF248 was purified by ion-exchange and gel filtration chromatography. The purified proteins stimulated the proliferation of TF-1 cells. Interestingly, the EC₅₀ value of His-hSCF248 was 1 pg/mL, 100-fold lower than 9 ng/mL hSCF164. Additionally, His-hSCF248 decreased the doubling time, increased the proportion of S and G2/M stages in the cell cycle, and increased the c-Myc expression at a 1000-fold lower concentration than hSCF164. In conclusion, His-hSCF248 was expressed in a soluble form in E. coli and had stronger activity than hSCF164. The molecular chaperone, MBP, enabled the soluble overexpression of hSCF164.     

Low/intermediate temperature pyrolyzed polysiloxane derived ceramics with increased carbon for electrical applications

This study focuses on the chemistry, thermal stability, and electrical conductivity of low/intermediate pyrolysis temperature (700?900 °C) polysiloxane derived ceramics. These ceramics were modified with additional carbon derived from divinylbenzene (DVB) added to the precursor. Their electrical properties were investigated for potential uses in micro-electrical mechanical systems (MEMS) and anodes for lithium batteries. The microstructure and chemical composition was investigated by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), Raman spectroscopy, and x-ray photoelectron spectroscopy (XPS); thermogravimetric analysis (TGA) provided insight into the thermal stability; and electrochemical impedance spectroscopy (EIS) into the electrical properties of the material. The increase of pyrolysis temperature and carbon content lead to an enhancement of the electrical conductivity, higher than previously reported values for intermediate pyrolysis temperature SiOC polymer derived ceramics. A limit of the amount of DVB that can be added to PHMS to produce a hybrid precursor has also been obtained.