Measurements of gamma-ray emission probabilities in the decay of americium-244g

ABSTRACT

Accurate data of gamma-ray emission probabilities are frequently needed when one quantitatively determines the amount of isotope by gamma-ray measurements or obtains neutron capture cross-sections using them. Americium-243, one of the most important minor actinides, produces ²⁴⁴Am after neutron capture. The 744-keV gamma-ray decaying from the ground state of ²⁴⁴Am has a relatively large gamma-ray emission probability about 66%; however, its uncertainty is as large as 29%. The uncertainty of the gamma-ray emission probability leads to a major factor of the systematic uncertainty on determining an amount of isotope, and therefore the gamma-ray emission probability was measured by using an activation method and an examined level structure of ²⁴⁴Cm. In this study, the emission probability of 744-keV gamma-ray was derived as 66.5 ± 1.1%, and its uncertainty was improved from 29% to 2%.     

Immunoglobulin-secreting cells in primary immunodeficiency diseases

To assess immunoglobulin production in vivo, the numbers of immunoglobulin-secreting cells were measured in uncultured peripheral blood mononuclear cells (PBMCs) of patients with primary immunoglobulin deficiency. The numbers of immunoglobulin-secreting cells were found to be variable, and they were well correlated with the serum concentrations of all three major immunoglobulin classes. Our results suggest that measurement of immunoglobulin-secreting cells in PBMCs is useful in the assessment of the ability to produce immunoglobulin in vivo.     

T1ρ study of pitch softening

Proton rotating frame spin-lattice relaxation time (T_1ρ) measurements have been made in 10 samples of pitch from room temperature to 673 K to obtain information about the mechanisms of pitch softening. The T_1ρ minimum of pitch was found to occur at approximately the same temperature as the softening point. This result suggests that the softening phenomenon of pitch can be detected at the molecular level by T_1ρ measurements. Laboratory frame spin-lattice relaxation time (T₁) measurements were also made on pitches to obtain information about the molecular motion of pitch in the high frequency ranges.     

Effective adoptive immunotherapy by T-LAK cells retargeted with bacterial superantigen-conjugated antibody to MUC1 in xenografted severe combined immunodeficient mice

To reinforce cytotoxic activity and the targeting ability of lymphokine-activated killer cells with a T-cell phenotype (T-LAK) for adoptive immunotherapy against human bile duct carcinoma (BDC), staphylococcal enterotoxin A (SEA) was conjugated chemically with MUSE11 monoclonal antibody (MUSE11 mAb), directed to the MUC1 antigen, using N-succinimidyl 3-(2-pyridyldithio) propionate and 2-iminothiolane HCl. Both SEA-conjugated MUSE11 mAb (SEA-MUSE11) and the F(ab')2 of MUSE11 mAb (SEA-F(ab')2) showed significant enhancement of T-LAK cell tumor neutralization for MUC1 positive-target tumor cells, even with a concentration of 0.01 microg/ml at an E:T ratio of 5:1 in vitro. In this in vitro test, MUC1-positive BDC cells were observed to attach to surrounding T-LAK cells in the presence of SEA-MUSE11 or SEA-F(ab')2. Remarkable tumor growth inhibition was observed in BDC-grafted severe combined immunodeficient mice to which 2 x 10(7) T-LAK cells preincubated with 2 microg of SEA-MUSE11 or SEA-F(ab')2, together with recombinant interleukin 2 (500 IU), were administered i.v. for 4 consecutive days, when tumor size was 5 mm in diameter. These results point to a promising adoptive immunotherapy for patients with BDC.     

Circadian rhythms in the incorporation and secretion of 3H-proline by odontoblasts in relation to incremental lines in rat dentin

Circadian incremental lines are universally found in the dentin of animals. They are believed to be caused by functional changes in odontoblasts over 24 hrs. However, the mechanism of rhythmic dentin formation has not yet been elucidated. In the present study, we investigated whether there is a 24-hour rhythm in the collagen-synthetic and secretory activities of odontoblasts by radioautography with 3H-proline as a tracer. Six different groups of rats were injected with 3H-proline at 0000, 0400, 0800, 1200, 1600, or 2000 after the animals had become acclimated to a 12/12-hour light-dark illumination cycle for 2 wks. One hour after the injection, the maxillary incisors were removed and processed for radioautographic study. The silver grains of 3H-proline were most intense over odontoblasts and predentin during the environmental light period, while the nadir occurred during the dark period. The peak value was approximately two-fold higher than the minimum value. Moreover, in the dentin from rats that had been infused with 3H-proline continuously for 10 days by means of osmotic minipumps, silver grains of 3H-proline were heavily distributed over the dark hematoxylin-stained incremental lines. Thus, we demonstrated that odontoblasts show circadian rhythm with regard to collagen synthesis and secretion. These rhythms in odontoblastic function may be responsible for circadian incremental lines in dentin.     

Simplified rapid non-radioactive PCR-SSCP method applied to K-ras mutation analysis

A newly modified non-RI, PCR-SSCP method is presented and applied to K-ras analysis of colorectal tumors. It comprises five steps: (1) sampling of tiny pieces of fresh solid tissue by scraping with disposable bamboo combs (thin bars made of bamboo, 3 x 3 x 120 mm in size); (2) one-step DNA extraction with lysis buffer containing proteinase K, Nonidet P-40 and Tween 20; (3) PCR with 108 bp, c-ki-ras 2 gene primers; (4) SSCP analysis with 10% formamide-added polyacrylamide gels; and (5) detection with silver staining. In comparison with conventional RI- or non-RI-PCR-SSCP, It can give reliable and clear results in a much shorter time (within a total of 6 h). This novel approach should allow more frequent use of molecular diagnosis in biopsies and surgical pathology.     

High‐luminous‐efficacy structure for plasma tubes

Abstract— The plasma‐tube‐array display is expected to become a wall‐sized display with very high luminous efficacy. The cell design for high luminous efficacy was investigated. Also, discharging in the plasma tube was observed in order to investigate the structure for high luminous efficacy. As the result, a high luminous efficacy of 5.4 lm/W was achieved.     

Optical scanning holography

This paper provides a tutorial on the principles of holography, followed by a review of a newly developed 3-D imaging technique in which 3-D optical information of an object cam be extracted by a 2-D optical scan of the object. The technique is called optical scanning holography (OSH). In the context of optical scanning holography, we discuss some of its potential applications such as holographic information transmission and television (TV) system, 3-D image coding and decoding, 3-D microscopy, and 3-D optical remote sensing. In most cases, feasibility has been proven but awaits broader application     

Characterization of the hemorrhagic reaction caused by Vibrio vulnificus metalloprotease, a member of the thermolysin family

Vibrio vulnificus is an opportunistic human pathogen causing wound infections and septicemia, characterized by hemorrhagic and edematous damage to the skin. This human pathogen secretes a metalloprotease (V. vulnificus protease [VVP]) as an important virulence determinant. When several bacterial metalloproteases including VVP were injected intradermally into dorsal skin, VVP showed the greatest hemorrhagic activity. The level of the in vivo hemorrhagic activity of the bacterial metalloproteases was significantly correlated with that of the in vitro proteolytic activity for the reconstituted basement membrane gel. Of two major basement membrane components (laminin and type IV collagen), only type IV collagen was easily digested by VVP. Additionally, the immunoglobulin G antibody against type IV collagen, but not against laminin, showed sufficient protection against the hemorrhagic reaction caused by VVP. Capillary vessels are known to be stabilized by binding of the basal surface of vascular endothelial cells to the basement membrane. Therefore, specific degradation of type IV collagen may cause destruction of the basement membrane, breakdown of capillary vessels, and leakage of blood components including erythrocytes.