Determining surface orientations of transparent objects based on polarization degrees in visible and infrared wavelengths

Techniques for modeling an object through observation are very important in object recognition and virtual reality. A wide variety of techniques have been developed for modeling objects with opaque surfaces, whereas less attention has been paid to objects with transparent surfaces. A transparent surface has only surface reflection; it has little body reflection. We present a new method for obtaining surface orientations of transparent surfaces through analysis of the degree of polarization in surface reflection and emission in visible and far-infrared wavelengths, respectively. This parameter, the polarization degree of reflected light at the visible wavelengths, is used for determining the surface orientation at a surface point. The polarization degree at visible wavelengths provides two possible solutions, and the proposed method uses the polarization degree at far-infrared wavelengths to resolve this ambiguity.     

Ingestion of plasmalogen markedly increased plasmalogen levels of blood plasma in rats

Plasmalogens, a subclass of phospholipids, are widely distributed in human and animals, and are taken into the body as food. However, no data exist on the intestinal absorption or fate of ingested plasmalogen. Here, we determined whether dietary plasmalogen is absorbed and whether blood and tissue concentrations increased in normal male Wistar rats by using four separate experiments. Phospholipids containing more than 20 wt% of plasmalogen extracted from the bovine brain were incorporated into test diets (10–15 wt%). In experiment 1, we estimated the absorption rate by measuring the plasmalogen vinyl ether bonds remaining in the alimentary tract of rats after the ingestion of 2 g of test diet containing 91 μmol plasmalogen. The absorption rate of plasmalogen was nearly 80 mol% after 4 h, comparable to the total phospholipid content in the test diet. In experiment 2, we observed no degradation of the plasmalogen vinyl ether bonds under in vitro conditions simulating those of the stomach and small intestinal lumen. In experiment 3 we confirmed a comparable absorption (36 mol%) by using a closed loop of the upper small intestine in anesthetized rats 90 min after injecting a 10 wt% brain phospholipid emulsion. Feeding a test diet containing 10 wt% brain phospholipids for 7 d increased plasmalogen concentration threefold in blood plasma and by 25% in the liver; however, no increases were seen in blood cells, skeletal muscle, brain, lungs, kidneys, or adipose tissue (experiment 4). We concluded that dietary plasmalogen is absorbed from the intestine and contributes to a large increase in plasmalogen levels in blood plasma.     

The Effects of Insulin on Immortalized Rat Schwann Cells,IFRS1

Schwann cells play an important role in peripheral nerve function, and their dysfunction has been implicated in the pathogenesis of diabetic neuropathy and other demyelinating diseases. The physiological functions of insulin in Schwann cells remain unclear and therefore define the aim of this study. By using immortalized adult Fischer rat Schwann cells (IFRS1), we investigated the mechanism of the stimulating effects of insulin on the cell proliferation and expression of myelin proteins (myelin protein zero (MPZ) and myelin basic protein (MBP). The application of insulin to IFRS1 cells increased the proliferative activity and induced phosphorylation of Akt and ERK, but not P38-MAPK. The proliferative potential of insulin-stimulated IFRS1 was significantly suppressed by the addition of LY294002, a PI3 kinase inhibitor. The insulin-stimulated increase in MPZ expression was significantly suppressed by the addition of PD98059, a MEK inhibitor. Furthermore, insulin-increased MBP expression was significantly suppressed by the addition of LY294002. These findings suggest that both PI3-K/Akt and ERK/MEK pathways are involved in insulin-induced cell growth and upregulation of MPZ and MBP in IFRS1 Schwann cells.     

Development of a strain for efficient degradation of polychlorinated biphenyls by patchwork assembly of degradation pathways

Rhodococcus jostii RHA1 accumulates chlorobenzoates (CBA) during the degradation of polychlorinated biphenyls (PCBs). CBA degradation is considered one of the rate-limiting steps in the complete degradation of PCBs. To reduce the accumulation of CBAs, the upper pathway enzyme genes for PCB degradation of RHA1 were introduced into a CBA-degrading bacterium, Burkholderia sp. NK8. The resulting recombinant strain exhibited no biphenyl 2,3-dioxygenase (BphA) activity encoded by bphAaAbAcAd genes, which encode the large and small subunits of the terminal oxygenase component and the ferredoxin and reductase subunits responsible for electron transfer from NADH to the large subunit. The remaining enzyme genes involved in the transformation of biphenyl to benzoate, bphB2C1D1, which encode dehydrogenase, ring-cleavage dioxygenase and hydrolase, conferred activities to NK8. To obtain the BphA activity of RHA1 in NK8, sets of BphA genes were constructed by combining the bphAaAbAcAd genes of RHA1 and bphA3A4 of Pseudomonas pseudoalcaligenes KF707, encoding the ferredoxin and reductase subunits. Hybrid derivatives of BphA containing the KF707 bphA3 conferred BphA activity to NK8, and a derivative containing the RHA1 bphAaAb and KF707 bphA3A4 genes exhibited the highest BphA activity. A plasmid containing the RHA1 bphAaAb and KF707 bphA3A4 genes plus the RHA1 bphB2C1D1 genes was constructed and introduced into NK8. The resulting recombinant strain efficiently degraded 2-, 3- and 4-chlorobiphenyls with an apparent reduction in CBA accumulation in comparison to the recombinant mutant strain, which had an insertion in the cbeA gene to inactivate CBA dioxygenase.     

Contribution of high p34cdc2 kinase activity to premature chromosome condensation of injected somatic cell nuclei in rat oocytes

The present study was undertaken to clarify the relationship between the p34cdc2 kinase activity of in vitro-aged or enucleated rat oocytes and the premature chromosome condensation (PCC) of microinjected cumulus cell nuclei. Wistar rat oocytes were placed in vitro up to 120 min after the animal was killed. The p34cdc2 kinase activity of the oocytes decreased in a time-dependent manner. The incidence of PCC was higher when nuclear injection into intact oocytes was completed in 15-45 min rather than 46-120 min. When rat oocytes were enucleated for subsequent nuclear injection, the p34cdc2 kinase activity transiently increased soon after enucleation but drastically decreased after 30 min. Removal of the cytoplasm instead of the meta-phase-plate did not affect the p34cdc2 kinase activity even after 60 min. PCC occurred in intact and cytoplasm-removed oocytes but not in enucleated oocytes. In contrast, oocytes from BDF1 mice exhibited a p34cdc2 kinase level twice that of rat oocytes and supported PCC despite enucleation. The p34cdc2 kinase level of intact rat oocytes was reduced to the equivalent level of aged (120 min) or enucleated (+60 min) oocytes by a 45 min treatment with roscovitine, an inhibitor of p34cdc2 kinase. None of the roscovitine-treated oocytes supported PCC while half of the control oocytes did. When rat oocytes were treated with MG132, a proteasome inhibitor, delayed inactivation of the p34cdc2 kinase was observed in the MG132-treated oocytes. A significantly higher proportion of the MG132-treated oocytes supported PCC when compared with the control oocytes. Moreover, a higher proportion of MG132-treated and enucleated oocytes carried two pseudo-pronuclei after cumulus cell injection and developed to the two-cell stage when compared with the enucleated oocytes at the telophase-II stage. These results suggest that the decreased level of p34cdc2 kinase activity in aged or enucleated rat oocytes is responsible for their inability to support PCC of microinjected donor cell nuclei and that inhibition of p34cdc2 kinase inactivation by chemicals such as MG132 is in part effective for rat oocytes to promote PCC and further development.     

Processing of Ultrafine-Grained Materials through the Application of Severe Plastic Deformation

Processing through the application of severe plastic deformation (SPD) has become an absorbing tool because it provides the potential for refining the grain size of polycrystalline bulk metals to the submicrometer or even the nanometer level. Several SPD methods are now available, but the more promising procedures seem to be equal-channel angular pressing (ECAP) and high-pressure torsion (HPT). This report examines these procedures with an emphasis on the principles of grain refinement and the mechanical properties developed at high temperatures in materials after processing by ECAP and the hardness homogeneity and microstructural evolution in materials processed by HPT. Moreover, recent observations on the ECAP and HPT processing also are discussed.     

Different models of hardness evolution in ultrafine-grained materials processed by high-pressure torsion

High-pressure torsion (HPT) is an attractive processing method in severe plastic deformation techniques involving the application of high compressive pressure with concurrent torsional straining. Excellent grain refinement is anticipated when using this technique to average grain sizes of the submicrometer or even nanometer ranges. Because of the significant microstructural changes during processing, there are numerous reports showing evolution in local hardness toward homogeneity throughout a disk diameter with increasing numbers of revolutions. The achieved hardness after HPT is mostly much higher than that in the as-received condition because of exceptional grain refinement although there are a limited number of metals and alloys showing softening or weakening after HPT processing. This paper was initiated to review recent discoveries in the experimental results on hardness evolution toward homogeneity during HPT processing and discuss the different models of hardness developments with respect to imposed equivalent strain by HPT processing for a range of metals and alloys. Moreover, recent results of hardness homogeneity and heterogeneity through thicknesses of the processed disks are discussed toward a complete understanding of hardness evolution in the UFG metals processed by HPT.