An increased incidence of apolipoprotein E2/E2 and E4/E4 in retinitis pigmentosa

Previous studies from our laboratory have shown that retinitis pigmentosa (RP), a family of hereditary retinal degenerations, is often accompanied by abnormal levels of cholesterol or polyunsaturated fatty acids. The requirement of the retina for n−3 fatty acids is well known, and a defect in the supply of these lipids (e.g., by apolipoproteins) could affect the course of the disease. The present study confirms and extends a report on apolipoprotein E (apo E) isoforms in German RP patients [Jahn, Oette, Esser, Bergmann, and Leiss, (1987)Ophthalmic Res. 19, 285–288] which showed a tenfold increased frequency of the E2/E2 phenotype compared to the average German population. In our study, apo E phenotypes were determined in the probands of 100 Scottish RP families. The findings revealed a 4-fold increase in the incidence of E2/E2 and an 8-fold increase in E4/E4 compared to a Scottish control population. These increases were statistically significant at theP<0.05 andP<0.01 levels, respectively. To investigate the possibility that some of these apparent E2/E2 or E4/E4 phenotypes might actually be new apo E mutations, we examined the behavior of the apo E on sodium dodecyl sulfate-polyacrylamide gels (E2 migrates anomalously) and on isoelectric focusing gels following cysteamine modification of cysteines. These studies showed that two RP patients possibly had new apo E mutations, though amino-terminal sequence analysis revealed no changes in the sequence of the first 19 residues; further sequence analysis is obviously warranted.     

Use of Lactobacillus rossiae DC05 for bioconversion of the major ginsenosides Rb1 and Re into the pharmacologically active ginsenosides C-K and Rg2

Rb1 and Re are the major ginsenosides in protopanaxadiol and protopanaxatriol with contents of 38.89 and 13.34%, respectively. β-Glucosidase-producing food grade Lactobacillus rossiae DC05 was isolated from kimchi using esculin-MRS agar and an enzyme of L. rossiae DC05 was used for bioconversion of the major ginsenosides Rb1 and Re. Strain DC05 showed strong activity in converting ginsenosides Rb1 and Re into the minor ginsenosides compound-K and Rg2, respectively. Within 4 days, 100% of ginsenoside Rb1 was decomposed and converted into C-K, while 85% of Re was decomposed and converted into Rg2 after 6 days of incubation. The biosynthesis rate of ginsenoside C-K was 72.88%, and the biosynthesis rate of Rg2 was 53.94%. Strain DC05 hydrolyzed ginsenosides Rb1 and Re along the pathway Rb1→Rd→F2→CK and the pathway Re→Rg2, respectively. The optimum temperature and pH of the enzyme were 30°C and 7.0, respectively.     

22 nm silicon nanowire gas sensor fabricated by trilayer nanoimprint and wet etching

In this work, we demonstrate the fabrication of silicon nanowires down to 22 nm wide using trilayer nanoimprint lithography and wet etching. Using the same template prepared by E-beam lithography (EBL), nanowires with top width of 22 nm and 75 nm are fabricated on boron-doped top silicon layer of SOI substrate. The two samples are tested in 250 ppm NO₂ ambient for gas detection. The 22 nm wide one shows a much higher relative sensitivity than the 75 nm wide one. The simulation which calculates the carrier density by solving Poisson equation was carried out and the results well explain the sensitivity disparity between the two samples.     

The Systematic Refinement for the Phase Change and Conversion Reactions Arising from the Lithiation of Magnetite Nanocrystals

Nanostructured materials can exhibit phase change behavior that deviates from the macroscopic phase behavior. This is exemplified by the ambiguity for the equilibrium phases driving the first open‐circuit voltage (OCV) plateau for the lithiation of Fe₃O₄ nanocrystals. Adding complexity, the relaxed state for Li_xFe₃O₄ is observed to be a function of electrochemical discharge rate. The phases occurring on the first OCV plateau for the lithiation of Fe₃O₄ nanocrystals have been investigated with density functional theory (DFT) through the evaluation of stable, or hypothesized metastable, reaction pathways. Hypotheses are evaluated through the systematic combined refinement with X‐ray absorption spectroscopy (XAS), X‐ray diffraction (XRD) measurements, neutron‐diffraction measurements, and the measured OCV on samples lithiated to x = 2.0, 3.0, and 4.0 in Li_xFe₃O₄. In contrast to the Li–Fe–O bulk phase thermodynamic pathway, Fe⁰ is not observed as a product on the first OCV plateau for 10–45 nm nanocrystals. The phase most consistent with the systematic refinement is LiFe₃O₄, showing Li+Fe cation disorder. The observed equilibrium concentration for conversion to Fe⁰ occurs at x = 4.0. These definitive phase identifications rely heavily on the systematic combined refinement approach, which is broadly applicable to other nano‐ and mesoscaled systems that have suffered from difficult or crystallite‐size‐dependent phase identification.     

Nanocellulose-Based Composites and Bioactive Agents for Food Packaging

Global environmental concern, regarding the use of petroleum-based packaging materials, is encouraging researchers and industries in the search for packaging materials from natural biopolymers. Bioactive packaging is gaining more and more interest not only due to its environment friendly nature but also due to its potential to improve food quality and safety during packaging. Some of the shortcomings of biopolymers, such as weak mechanical and barrier properties can be significantly enhanced by the use of nanomaterials such as nanocellulose (NC). The use of NC can extend the food shelf life and can also improve the food quality as they can serve as carriers of some active substances, such as antioxidants and antimicrobials. The NC fiber-based composites have great potential in the preparation of cheap, lightweight, and very strong nanocomposites for food packaging. This review highlights the potential use and application of NC fiber-based nanocomposites and also the incorporation of bioactive agents in food packaging.