Effect of 8 MeV electron irradiation on electrical properties of CuInSe2 thin films

Radiation damages due to 8 MeV electron irradiation in electrical properties of CuInSe₂ thin films have been investigated. The n-type CuInSe₂ films in which the carrier concentration was about 3×10¹⁶ cm⁻³, were epitaxially grown on a GaAs(0 0 1) substrate by RF diode sputtering. No significant change in the electrical properties was observed under the electron fluence <3×10¹⁶ e cm⁻². As the electron fluence exceeded 10¹⁷ e cm⁻², both the carrier concentration and Hall mobility slightly decreased. The carrier removal rate was estimated to be about 0.8 cm⁻¹, which is slightly lower than that of III–V compound materials.     

Accelerator Analysis of Tributyltin Adsorbed onto the Surface of a Tributyltin Resistant Marine Pseudoalteromonas sp. Cell

Tributyltin (TBT) released into seawater from ship hulls is a stable marine pollutant and obviously remains in marine environments. We isolated a TBT resistant marine Pseudoalteromonas sp. TBT1 from sediment of a ship’s ballast water. The isolate (10^{9.3 ± 0.2} colony-forming units mL⁻¹) adsorbed TBT in proportion to the concentrations of TBTCl externally added up to 3 mM, where the number of TBT adsorbed by a single cell was estimated to be 10^8.2. The value was reduced to about one-fifth when the lysozyme-treated cells were used. The surface of ethanol treated cells became rough, but the capacity of TBT adsorption was the same as that for native cells. These results indicate that the function of the cell surface, rather than that structure, plays an important role to the adsorption of TBT. The adsorption state of TBT seems to be multi-layer when the number of more than 10^6.8 TBT molecules is adsorbed by a single cell.     

Suppression of photo-induced dilation in cyanide treated hydrogenated amorphous silicon films

Effects of cyanide (CN) treatment with hydrogenated amorphous silicon (a-Si:H) films have been investigated. The decrease of ΔV/V was observed in cyanide treated a-Si:H films and the successive thermal annealing at 200°C after CN treatment induced the further reduction of the ΔV/V. XPS spectra show the indirect evidence that the cyanide species is present within 10 nm from the hydrogenated amorphous silicon surface. The results of CN treatment with a-Si:H solar cells are demonstrated.     

Failure to reject an allografted tumor after elimination of macrophages in mice

After an i.p. transplantation of an allogeneic tumor (Meth A) to C57BL/6 mice, a macrophage (M phi)-rich, non-T, non-NK cell population is induced as the major infiltrate and cytotoxic cells. We here evaluated the role of the M phi s in the rejection of allografted Meth A cells and characterized the M phi s in comparison with other well-known M phi s. At all time intervals after transplantation, the highest cytotoxic activities against Meth A tumor were obtained with the M phi-rich population. In addition, the lymphocyte-rich population had a significant but low cytotoxic activity, whereas two other population types, granulocytes and large granular cells, were inactive. When the M phi-rich or the T cell-depleted M phi-rich population was i.p. transplanted simultaneously with Meth A cells into untreated C57BL/6 mice, the tumor cells were rejected without growth. After specific elimination of M phi s by in vivo application of dichloromethylene diphosphonate-containing liposomes, the cytotoxic activity against Meth A cells was hardly induced at the transplantation site of Meth A cells and the allografted Meth A tumor continued to grow, indicating that a type of M phi is the effector cell essential for the rejection. In contrast to other well-known M phi s, the cytotoxic activity against Meth A cells was cell-to-cell contact dependent and soluble factor (e.g., NO and TNF-alpha) independent. Moreover, the cytotoxic activity of the M phi s (H-2b) against 51Cr-labeled Meth A (H-2d) cells was inhibited by the addition of unlabeled H-2d, but not H-2b, H-2k or H-2h, lymphoblasts as well as Meth A cells, implying the specific interaction of the M phi s with H-2d cells.     

Ectopic accumulation of 99mTc-HMDP in primary lung cancer in comparison with CT findings

Hypertension attributable to pheochromocytoma is a very attractive model for the elucidation of the pathogenesis of hypertension. Sixteen different point mutations in the RET proto-oncogene and 30 mutations in the Von Hippel-Lindau (VHL) tumor suppressor gene have been identified so far associated with expression of pheochromocytoma. Each of these mutations initiates either the syndrome of multiple endocrine neoplasia type 2 (MEN 2) (MEN 2A and MEN 2B) or the VHL disease. Certain mutations in both genes are associated with the presence of pheochromocytoma. In general, these pheochromocytomas produce catecholamines that result in hypertension. Therefore, analysis for germline mutations in these genes are of practical value, because susceptibility to these diseases can be predicted in as yet clinically unaffected relatives.     

Structural study of degraded ZnMgSSe blue light emitters

Using electroluminescence (EL) topography and transmission electron microscopy (TEM), we investigated the nonluminescent regions which form while current is being injected into ZnMgSSe/ZnSSe/ZnCdSe-based blue light emitters. Small dark spots were observed just after turn-on and spread out forming rough nonluminescent triangles in the <100> directions in the EL image of the active region. TEM studies showed that the small dark spots are pre-existing stacking faults originating at the substrate/epitaxial layer interface. The nonluminescent triangles were found to be a dense region of dislocation dipoles and dislocation loops. Each dipole was aligned along two <110> directions in the {111} planes. The Burgers vectors were of the type a/2<011> inclined at 45° to the (001) junction plane.     

Peptide separation in normal phase liquid chromatography

A new method is established for separating peptides in normal phase liquid chromatography using TSK gel Amide-80, carbamoyl groups bonded to a silica gel matrix, and an acetonitrile-water solution containing 0.1% trifluoroacetic acid. Peptide retention time increased with acetonitrile concentration in the initial eluent. Hydrophilic peptides with no retention in a reversed phase column were retained and separated in the present method. Separation selectivities in the present and reversed phase methods differed significantly. Two-dimensional separation of protein digest using reversed and normal phases was conducted, taking advantage of the differences in selectivities. All peptides obtained from the digest could be separated completely. The present method is useful for separating peptide mixtures in conjunction with reversed phase liquid chromatography. Peptide recovery from the Amide-80 column exceeded 80%, as with the reversed phase column, and repeatability and reproducibility were satisfactory.     

Differential regulation by hematopoietic growth factors of apoptosis and mitosis in acute myeloblastic leukemia cells

We evaluated the effects of various hematopoietic growth factors (HGFs) on the prevention of apoptosis in blasts from 19 patients with acute myeloblastic leukemia (AML) by assessing DNA ladder formation. After incubation without HGF, apoptosis was noted in all but two patients. HGFs prevented, did not affect, or enhanced apoptosis in 39 (60%), 14 (22%), or 12 (18%) of 65 suspension cultures, respectively. HGFs that prevented apoptosis also stimulated and/or synergized blast colony formation in 35 of 39 corresponding methylcellulose cultures. HGFs that alone stimulated colony formation also prevented apoptosis in all but two of 28 corresponding suspension cultures. In contrast, HGFs that did not prevent apoptosis also failed to stimulate growth in 17 of 26 corresponding methylcellulose cultures. HGFs that enhanced apoptosis alone never stimulated colony formation. After incubation, we noted enhanced c-fos and cjun genes as well as induction of p21 protein. An appropriate dose of HGF elevated c-fos, reduced c-jun and p21, induced G1/S transition, and inhibited apoptosis. In two patients, apoptosis was not induced after incubation. Cells not treated with HGF expressed no c-fos, c-jun, or c-myc, and remained in G0/G1. Taken together, our results support the conclusion that not only c-fos, cjun, and c-myc, but also p53 and p21 are required for blast apoptosis. HGF differentially prevents apoptosis and induces mitosis, and both events seem to be integral to the self-renewal of AML clonogenic cells.     

Late complications in traumatic coronary artery fistula: report of a case requiring surgical repair after 8 years

A full-length cDNA clone for a progesterone membrane binding protein from porcine vascular smooth muscle cells was isolated and the complete nucleotide sequence determined. The cDNA encodes a protein of 194 amino acids with a transmembrane segment. This protein is likely to represent the first steroid membrane receptor or a part of it for which sequence information is available.