Modification of the Interface Nanostructure and Magnetic Properties in Nd-Fe-B Thin Films.

The effects of Nd2Fe14B grain size and Nd coating on the coercivity in sputter-deposited Nd-Fe-B/Nd thin films have been investigated in order to gain an insight into the coercivity mechanism of Nd-Fe-B magnets. Highly textured Nd2Fe14B particles were grown successfully on the MgO(100) single-crystal substrate with the Mo underlayer. As the Nd-Fe-B layer thickness t NFB was decreased from 70 to 5 nm, the coercivity H c increased gradually from 6.5 to 16 kOe. By depositing the Nd overlayer onto these films and post-annealing at 500 °C, the H c value further increased from 17.5 kOe (t NFB=70 nm) to 26.2 kOe (t NFB=5 nm). The amount of H c increase by the combination of the Nd coating and post-annealing was about 10 kOe irrespective of the t NFB value. These results therefore suggest an independence of size and interface effects on the coercivity of Nd-Fe-B magnets.

Scanning electron microscope observation of dislocations in semiconductor and metal materials.

Scanning electron microscope (SEM) image contrasts have been investigated for dislocations in semiconductor and metal materials. It is revealed that single dislocations can be observed in a high contrast in SEM images formed by backscattered electrons (BSE) under the condition of a normal configuration of SEM. The BSE images of dislocations were compared with those of the transmission electron microscope and scanning transmission electron microscope (STEM) and the dependence of BSE image contrast on the tilting of specimen was examined to discuss the origin of image contrast. From the experimental results, it is concluded that the BSE images of single dislocations are attributed to the diffraction effect and related with high-angle dark-field images of STEM.

Variations in contrast of scanning electron microscope images for microstructure analysis of Si-based semiconductor materials.

Image contrasts of Si-based semiconducting materials have been investigated by using the latest scanning electron microscope with various detectors under a range of experimental conditions. Under a very low accelerating voltage (500 V), we obtained a good image contrast between crystalline SiGe whiskers and the amorphous matrix using an in-lens secondary electron (SE) detector, while the conventional topographic SE image and the compositional backscattered electron (BSE) image gave no distinct contrast. By using an angular-selective BSE (AsB) detector for wide-angle scattered BSE, on the other hand, the crystal grains in amorphous matrix can be clearly visualized as 'channelling contrast'. The image contrast is very similar to that of their transmission electron microscope image. The in-lens SE (true SE falling dots SE1) and the AsB (channelling) contrasts are quite useful to distinguish crystalline parts from amorphous ones.

[Economic aspect of alcohol-related disabilities in patients of gastroenterology and hepatology].

Alcoholic patients frequently visit a medical center with the alcohol-related organ damage. The medical utilization and expenses of these patients is not only for the treatment of alcohol dependence, but also mainly for the treatment of alcohol-related organ diseases. This study was conducted to clarify the influence of alcohol dependence on the medical expense of internal medicine, especially of gastroenterology and hepatology. Forty four patients who visited the department of gastroenterology and hepatology of our institute since November 2001 were included in the study. All of the patients were heavy drinkers and were suffered from alcohol damages in various organs. Medical expenses of these patients were calculated from the amount of the claim for health insurance system record of our hospital. Average cumulative number of the patients per month was 15.5 +/- 2.8 in out patient and 4.2 +/- 2.4 in hospitalized patient. Medical expenses in these patients, however, were lower in out patients than in hospitalized patients. Cumulative medical expense per month was 238,000 +/- 66,000 yen and 1,801,000 +/- 1,338,000 yen respectively. Alcoholic liver cirrhosis is one of the most frequently encountered disorder related to heavy drinking and needs hospitalization for the treatment of complications of this end stage liver disease. 13 patients (29.5%) were diagnosed as having alcoholic liver cirrhosis in this study. Some of the patients successfully abstained, but irreversible liver damage necessitated repeated hospitalization for the treatment of decompensated cirrhosis. As a result, cumulative medical expense per patient with alcoholic liver cirrhosis was significantly larger than those with noncirrhotic patient. These results suggest that abstinence from alcohol in early stage of alcoholic liver disease, before development of cirrhosis, is important from economic point of view.

Application of FIB microsampling technique to long-period ordered TiAl single crystal with composition gradient.

Metastable long-period superstructures in an L10-TiAl single crystal with a composition gradient were observed successfully by transmission electron microscopy with a focused ion beam (FIB) microsampling technique. The composition gradient from 54.7 to 75 at.% Al with approximately 6 microm width was detected by electron probe microanalysis and foil specimens containing the composition-gradient area were fabricated by the FIB microsampling method. The foil specimens clearly exhibit sequential changes in long-period superstructure depending on the Al concentration.

HRTEM image contrast and atomistic microstructures of long-period ordered Al-rich TiAl alloys.

Long-period superstructures formed in off-stoichiometric L 1(0)-TiAl alloys were investigated by high-resolution transmission electron microscopy (HRTEM). The HRTEM analysis combined with multislice simulation and image processing was carried out to clarify atomistic microstructures of Al5Ti3 and h-Al2Ti ordered states and a short-range ordered (SRO) state in Ti-62.5 at.% Al alloys. Aluminium atoms in the (002) Ti layers form square-, lean rhombus- and fat rhombus-type ordered clusters in the SRO state. The ordered clusters are in contact with each other and form microdomains of various long-period superstructures. The ordered clusters are tiled periodically in a long range to form Al5Ti3 or h-Al2Ti domains and characteristic antiphase boundary structures.

Effect of in vitro interferon-beta administration on hepatitis C virus in peripheral blood mononuclear cells as a predictive marker of clinical response to interferon treatment for chronic hepatitis C.

AIM: To test whether in vitro incubation of peripheral blood mononuclear cells (PBMC) with interferon (IFN) could efficiently decrease hepatitis C virus-RNA (HCV-RNA) amount and to analyze whether this effect was associated with clinical response to IFN. METHODS: Twenty-seven patients with histologically proven chronic hepatitis C were given intravenous administration of 6 million units (MU) IFN-beta daily for 6 weeks followed by three times weekly for 20 weeks. PBMC collected before IFN therapy were incubated with IFN-beta and HCV-RNA in PMBC was semi-quantitatively determined. RESULTS: Twenty-five patients completed IFN therapy. Eight patients (32%) had sustained loss of serum HCV-RNA with normal serum ALT levels after IFN therapy (complete responders). HCV-RNA in PBMC was detected in all patients, whereas it was not detected in PBMC from healthy subjects. In vitro administration of IFN-beta decreased the amount of HCV-RNA in PMBC in 18 patients (72%). Eight of these patients obtained complete response. On the other hand, none of the patients whose HCV-RNA in PBMC did not decrease by IFN-beta was complete responders. Multiple logistic regression analysis revealed that the decrease of HCV-RNA amount in PBMC by IFN-beta was the only independent predictor for complete response (P<0.05). CONCLUSION: The effect of in vitro IFN-beta on HCV in PBMC reflects clinical response and would be taken into account as a predictive marker of IFN therapy for chronic hepatitis C.

Hemophagocytic syndrome in ileum-origin B-cell lymphoma.

A 56 year-old-man was admitted due to upper abdominal tumor and was diagnosed as having stage IVb diffuse B-cell malignant lymphoma that originally developed in the terminal ileum. The first and the second administrations of CHOP (cyclophosphamide, 750 mg/m(2); adriamycin, 50 mg/m(2); vincristine, 1.4 mg/m(2); and prednisolone, 100 mg/day) therapy were effective; however, the third course of therapy was postponed because of an episode of massive hematochezia. After this episode, lymph nodes began to enlarge and progressive pancytopenia occurred. Bone marrow smear showed the proliferation of reactive histiocytic cells which phagocytized red blood cells, white blood cells, and platelets. B-cell lymphoma-associated hemophagocytic syndrome (B-LAHS) was diagnosed. This case is extremely rare because: (1) LAHS occurred in an ileum-origin B-cell lymphoma, and (2) LAHS developed during an interval after chemotherapy.