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Analyses of various lipid fractions of sections of cucumbers and of good and bloated dill pickles showed that marked changes occur in all lipid fractions during fermentation. The most striking difference noted was the decrease in the phospholipid fraction. A nearly fourfold increase in free fatty acid, as well as a marked increase in the neutral fat fatty acids and unsaponifiables, occurred. Gas chromatographic analyses of the methyl esters of fatty acids from the various lipid fractions yielded further interesting data. From the analyses, 41 esters were identified; however, 16 of the esters accounted for at least 95% of the acids. Among the marked changes were the increases in linoleic and linolenic acids in good pickles, in contrast to the increase in oleic acid in the bloated pickles. The presence of tridecenoic acid in cucumbers, and its absence in pickles; and the absence of caproic, caprylic, and capric acids in cucumbers, and its presence in pickles, were interesting. The data demonstrated that the lipid alterations that occur during fermentation of cucumbers are analogous to those previously reported for the sauerkraut fermentation.  相似文献   
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Human H ferritin (HuHF) assembles from 24 four-helix bundles to form an approximately 500 kDa protein with an 8 nm internal cavity. HuHF provides a useful model for studying the transport of metal ions in solution to buried reaction sites in proteins. In this study, HuHF was redesigned to facilitate noble metal ion (Au(3+), Ag(+)) binding, reduction, and nanoparticle formation within the cavity. Computationally determined amino acid substitutions were targeted at four external and four internal surface sites. A variant with a total of 96 cysteines and histidines removed from the exterior surface and 96 non-native cysteines added to the interior surface retained wild-type stability and structure, as confirmed by X-ray crystallography, and promoted the formation of silver or gold nanoparticles within the protein cavity. Crystallographic studies with HuHF variants provide insight into how ferritins control access of metal ions to interior residues that perform chemistry.  相似文献   
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Peripheral blood-derived multipotent adult progenitor cells (PBD-MAPCs) are a novel population of stem cells, isolated from venous blood of green fluorescent protein transgenic swine, which proliferate as multicellular non-adherent spheroids. Using a simple differentiation protocol, a large proportion of these cells developed one of five distinct neural cell phenotypes, indicating that these primordial cells have high neurogenic potential. Cells exhibiting neural morphologies developed within 48 h of exposure to differentiation conditions, increased in percentage over 2 weeks, and stably maintained the neural phenotype for three additional weeks in the absence of neurogenic signaling molecules. Cells exhibited dynamic neural-like behaviors including extension and retraction of processes with growth cone-like structures rich in filamentous actin, cell migration following a leading process, and various cell-cell interactions. Differentiated cells expressed neural markers, NeuN, β-tubulin III and synaptic proteins, and progenitor cells expressed the stem cell markers nestin and NANOG. Neurally differentiated PBD-MAPCs exhibited voltage-dependent inward and outward currents and expressed voltage-gated sodium and potassium channels, suggestive of neural-like membrane properties. PBD-MAPCs expressed early neural markers and developed neural phenotypes when provided with an extracellular matrix of laminin without the addition of cytokines or growth factors, suggesting that these multipotent cells may be primed for neural differentiation. PBD-MAPCs provide a model for understanding the mechanisms of neural differentiation from non-neural sources of adult stem cells. A similar population of cells, from humans or xenogeneic sources, may offer the potential of an accessible, renewable and non-tumorigenic source of stem cells for treating neural disorders.  相似文献   
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It is important to understand parental effects on early life history of fish as manifested, for example, in individual fitness of offspring. Immediately after fertilization, parental contributions (both genetic and non‐genetic) to embryos will affect larval ontogeny, physiology, morphology and survival. In marine fish, rates of natural mortality are highest during early life and are negatively correlated with rates of growth and body size. In these early life stages (eggs, larvae, young juveniles) subtle differences in mortality can cause large differences in recruitment and year‐class success. Therefore, it is particularly critical to understand factors that contribute to variability in mortality during early life. This study focuses on evaluating the potential influence of paternity on rates of mortality and development in eggs and larvae of Northwest Atlantic cod, Gadus morhua. To accomplish this 12 males and two females were crossed using a full‐factorial breeding design. Paternity had a strong influence on fertilization success, hatching success, cumulative embryonic mortality, larval standard length, eye diameter, yolk‐sac area, and cumulative larval mortality. Female 1 showed an overall ‘weaker’ performance of offspring than Female 2, indicating that deviances can stem from differences in female quality. Nevertheless, paternal contributions to embryonic and larval development were still evident despite differences in female quality, showing that sire effects on offspring are undeniable and can serve as important sources of variation during early life stages in fishes. Overall, these findings have implications for furthering the understanding of recruitment variability and can be used to optimize reproductive output for the aquaculture industry. In addition, the data suggests that the choice of mate during spawning can play a large role in offspring fitness.  相似文献   
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