Using a grating pattern of parallel nitride and oxide stripes on the silicon surface, self-interstitial concentration at the Si/SiO2 interface is accurately determined by means of oxidation-induced stacking fault growth observation. The results show that the interstitial concentration at the interface is found to be determined by the oxidation of interstitials in the oxide rather than self-interstitial diffusion in bulk silicon. A newly proposed physical model incorporates the balance among the generation rate of interstitials at the oxidizing interface, the annihilation rate of interstitials due to surface regrowth, and the rate at which they diffuse into the oxide and react with incoming oxidants. For higher oxidation rates, the model predicts that the interstitial concentration follows a 0.5 power dependence on oxidation rate. For slower oxidation rates, the concentration at the interface becomes lower than the equilibrium interstitial concentration, leading to the oxidation-retarded diffusion of dopants with a high fractional interstitialcy diffusion component.

Fucoidan is a sulfated poly(L-fucopyranose) present in brown marine algae. In this study, we examined the effect of native and chemically oversulfated fucoidans (NF and OSF) on the tube structure formation by human umbilical vein endothelial cells (HUVEC) on the basement membrane preparation, Matrigel. Unlike NF, OSF significantly decreased the tube formation: maximal inhibition (50% of control) was obtained with 25 micrograms/ml. The OSF effect was mediated, at least in part, through the inhibition of HUVEC migration, as determined by the ability to block chemotaxis in a Transwell chamber assay. Quantitative immunoreactive assays for tissue-type plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) in the culture media indicated that OSF (25 micrograms/ml) increased the accumulation of PAI-1 antigen, but not of t-PA antigen, 2.7-fold compared with control. The release of both antigens by HUVEC was slightly affected by the addition of NF. Determination of the media levels of type IV collagenase activity and tissue inhibitor of metalloproteinase-1 (TIMP-1) antigen showed that OSF (25 micrograms/ml) decreased the collagenolytic activity by 50% compared to the control, without alteration of the TIMP antigen level. However, the collagenase inhibition by OSF was not observed in an assay system using purified enzyme. NF had no effect on collagenase activity or TIMP-1 antigen levels. These results indicate that the introduction of sulfate groups into NF enables it to effectively inhibit the formation of capillary-like structures by HUVEC on Matrigel by reducing the basement membrane destruction and cell migration. It is involved as at least one of the mechanisms by which the OSF-induced increase in HUVEC PAI-1 decreases plasmin formation and suppresses the following pro-collagenase activation.

A high MCV value may be used as a simple index of the risk of colorectal adenomas, regardless of alcohol consumption.

No abstract

Since there were no available data about colonic diverticular bleeding in extremely elderly patients (>80 years old) treated with direct oral anticoagulants (DOACs), we tried to determine clinical characteristics in those with colonic diverticular bleeding taking DOACs and to compare clinical outcomes of those in DOAC-treated to those in warfarin-treated . We enrolled DOAC-treated ( n = 20) and warfarin-treated ( n = 23) extremely elderly patients with diverticular bleeding diagnosed by colonoscopy. We performed a retrospective review of patients’ medical charts and endoscopic findings. We classified colonic diverticular bleeding based on endoscopic features due to modified previous study following three groups, type A (active bleeding), type B (non-active bleeding) and type C (bleeding suspected). Clinical outcomes such as number of recurrent bleeding, thrombotic events and mortality were estimated. There were no differences in endoscopical features and clinical characteristics between patients treated with DOAC and warfarin therapy. However, the number of recurrent bleeding, frequency of required blood transfusions and units of blood transfusion in warfarin-treated patients were significantly higher ( p <0.05) compared to those in DOAC-treated groups. In addition, mortality and thrombotic events did not differ between DOAC- and warfarin-treated patients. Clinical outcomes suggest that DOACs can be recommended for extremely elderly patients with colonic diverticular disease.