Convergent-beam and small-area-parallel-beam electron diffraction of icosahedral quasicrystals of a melt-quenched Al-Mn alloy

Intensity distribution in convergent-beam electron diffraction (CBED) patterns obtained from icosahedral quasicrystas of a melt-quenched Al-Mn alloy reveal that the quasicrystals do not have fivefold, threefold and twofold rotation axes and have no inversion center, although ordinary diffraction patterns obtained thus far showed these rotation symmetries. CBED patterns taken from specimen areas of about 3 nm in diameter show a deviation in geometry in spot positions from the fivefold rotation symmetry. Ring patterns due to higher-order Laue zone reflections are not observed in CBED patterns. Kikuchi bands are composed of two sub-bands in the five equivalent directions, and each band has a different intensity profile. Parallel-beam (3 × 10^-5 rad) electron diffraction patterns obtained from specimen areas less than 100 nm in diameter also show a deviation from the fivefold symmetry in spot positions and make clear that each Bragg reflection consists of many fine spots which show no fivefold symmetry. It is proven experimentally that all the observed reflections occur already in the approximation of kinematical diffraction, although their intensities may be modified by dynamical diffraction effect.     

On-line scheduling for adaptive control machine tools in FMS

Adaptive control is available to adjust the operating speed of machine tools in FMS according to the condition of production, but it changes the time of each operation and disturbs the previously determined schedule. In this paper, on-line scheduling which changes the schedule according to the change of operating times is proposed. It is verified by computer simulation that on-line scheduling using SLACK, EDD, or the Look Ahead heuristic rule is available. The Look Ahead rule is the best for decreasing the lateness of due dates. Algorithms to change the adaptive control mode between optimization for cost performance and that for productivity according to the condition of the schedule are proposed, and their validity is verified by computer simulation.     

Low-threshold membrane BH-DFB laser arrays with precisely controlled wavelength over a wide range

We report on the low-threshold operation of membrane buried heterostructure distributed feedback laser arrays. 45 devices were fabricated on a wafer covering a wide wavelength range of 75 nm. The lowest threshold pump power as low as 0.64 mW along with the submode suppression-ratio of over 30 dB at two times the threshold were successfully obtained at room-temperature continuous-wave condition.     

Immunohistochemical detection of K-sam protein in stomach cancer

The K-sam gene, originally isolated as an amplified gene from the stomach cancer cell line KATO-III, is characterized by its preferential amplification in the undifferentiated type (diffuse type) of stomach cancer and encodes one of the receptors for heparin-binding growth factors or fibroblast growth factors. The K-sam gene has been isolated by different methods and has been designated BEK, TK14, and Cek2. The receptor for keratinocyte growth factor was also found to be encoded by the same gene. To examine the expression of the K-sam protein in stomach cancer, polyclonal antibody pK1-2 was raised against the extracellular domain of the gene product. This antibody detected K-sam proteins by Western blot and flow cytometry analyses in stomach cancer cell lines KATO-III and HSC39, in which the K-sam gene is amplified and overexpressed. By immunohistochemical analysis, 20 of 38 cases of the undifferentiated type of advanced stomach cancer were K-sam positive, whereas none of 11 cases of the differentiated or intestinal type revealed K-sam staining. The K-sam product was observed predominantly in diffusely infiltrative lesions. In one autopsy case, the K-sam protein was detected only focally in the primary tumor, whereas markedly increased staining for the K-sam product was detected diffusely in the metastasized tumor in the lymph node and liver. These results suggest that K-sam overexpression is associated with the malignant phenotype of the undifferentiated type of stomach cancer, such as infiltrative growth and metastasis.     

Luminosity monitor for the venus detector at TRISTAN

We constructed a luminosity monitor of the lead-scintillator sandwich type for the VENUS detector at the e⁺e⁻ collider TRISTAN. Photomultiplier tubes with transmissive mesh dynodes could be operated fairly well in a high magnetic field and hence the readout optics system was considerably simplified. We present the performance of the luminosity monitor for e⁺e⁻ collisions at √s = 50 and 52 GeV.     

Suppression of leukotriene formation in RBL-2H3 cells that overexpressed phospholipid hydroperoxide glutathione peroxidase

The overexpression of phospholipid hydroperoxide glutathione peroxidase (PHGPx) by RBL-2H3 cells was used as the basis for an investigation of the effects of PHGPx on the formation of leukotrienes. The rates of production of leukotriene C4 (LTC4) and leukotriene B4 (LTB4) in cells that overexpressed PHGPx were 8 times lower than those in a control line of cells. The reduction in rates of production of leukotrienes apparently resulted from the increase in the PHGPx activity since control rates of formation of leukotrienes could be achieved in PHGPx-overexpressing cells upon inhibition of PHGPx activity by diethyl malate. The conversion of radioactively labeled arachidonic acid to intermediates in the lipoxygenase pathway, such as 5-hydroxyeicosatetraenoic acid (5-HETE), LTC4, and LTB4, was strongly inhibited in PHGPx-overexpressing cells that had been prelabeled with [14C]arachidonic acid. PHGPx apparently inactivated the 5-lipoxygenase that catalyzed the conversion of arachidonic acid to 5-hydroperoxyeicosatetraenoic acid (5-HPETE) since 5-HPETE is a common precursor of 5-HETE, LTC4, and LTB4. The rates of formation of LTC4 and LTB4 in PHGPx-overexpressing cells returned to control rates upon the addition of a small amount of 12-HPETE. Flow cytometric analysis revealed that the rapid burst of formation of lipid hydroperoxides induced by A23187 was suppressed in PHGPx-overexpressing cells as compared with the control lines of cells. Subcellular fractionation analysis showed that the amount of PHGPx associated with nuclear fractions from PHGPx-overexpressing cells was 3.5 times higher than that from the control line of cells. These results indicate that PHGPx might be involved in inactivation of 5-lipoxygenase via reductions in levels of the fatty acid hydroperoxides that are required for the full activation of 5-lipoxygenase. Thus, in addition to its role as an antioxidant enzyme, PHGPx appears to have a novel function as a modulator of the production of leukotrienes.     

Congenital absence and aberrant course of the internal carotid artery

OBJECTIVE: To evaluate the extent of vascularization by assessing vascular surface density in renal cell carcinomas (RCCs) of different nuclear grades, and in normal renal cortex and medulla. MATERIALS AND METHODS: Specimens of 79 RCCs of different nuclear grades (16 of G1, 42 of G2 and 21 of G3) were immunostained with the lectin Ulex europaeus agglutinin-I (UEA I). The vascular surface density of tumour tissue was assessed stereologically using a test grid at x400 magnification and compared to the values obtained in normal renal tissue. RESULTS: G3 tumours had a lower vascular surface density than had G1 and G2 RCCs and normal renal tissue of the cortex and medulla (P < 0.001, respectively). G1 tumours had a significantly higher vessel density than had normal medullary parenchyma and G2 carcinomas (P < 0.001). Vessel density was not significantly different among G1 tumours and cortical parenchyma in controls and among normal medullary tissue and G2 tumours. Statistical analysis showed that the vascular surface density was independent of tumour stage and size and the age and sex of the patients. CONCLUSION: The degree of vascularization in RCCs decreased with their grade of differentiation, suggesting that the extent of neovascularization in tumour tissue reflects the relationship between tumour cell proliferation and vascular growth. The values of vascular surface density in normal renal tissue of the cortex and medulla partially overlapped with those obtained in tumour tissue.