Polymerization of hexachlorocyclotriphosphazene by sulphur and selenium

The thermal bulk polymerization of hexachlorocyclotriphosphazine is described. The possibility of obtaining soluble polymer using sulphur and selenium as catalysts was investigated. It was found that the catalytic activity of selenium was much lower than that of sulphur. Monomeric sulphur may be acting as a chlorine-attractive agent for hexachlorocyclotriphosphazine.     

Seawater desalting by electrodialysis

A 120 M³/day electrodialysis plant for municipal seawater desalting was constructed by Asahi Chemical Industry Co., Ltd. for the city of Hofu, Japan, with operation beginning in September, 1974. The performance and maintenance for the first year of operation is discussed. The fully automatic system is inspected once per week by an operator and is serviced twice per year. Membrane replacement after 16 months of operation is less than one percent. Desalacion del agua de mar por electrodialisis     

Asbestos fiber analysis in seven asbestosis cases

OBJECTIVE: Smoking is a risk factor for the development of thyroid-associated ophthalmopathy, an inflammatory process primarily affecting the fibroblasts in extraocular muscles. We wished to determine whether the extraocular muscle fibroblasts are more sensitive than dermal fibroblasts to T-cell derived cytokines, as a reason for this anatomical localization, and whether hypoxia alters fibroblast function, as one explanation for the susceptibility conferred by smoking. DESIGN: Fibroblasts derived from the skin or extraocular muscles of healthy subjects were cultured with cytokines under normal (5% CO2:95% air) and hypoxic (5% CO2:95% N2) conditions. MEASUREMENTS: Glycosaminoglycan, protein and DNA synthesis were measured by assessing incorporation of D-6-3H-glucosamine, 3H-amino acids, and 3H-thymidine respectively. RESULTS: alpha-interferon and interleukin-6 had no effect on fibroblasts. gamma-interferon, tumour necrosis factor and interleukin-1 stimulated glycosaminoglycan synthesis; this effect was greater in orbital than in dermal fibroblasts with gamma-interferon and interleukin-1 (P < 0.05). The same cytokines stimulated total protein with a greater response in orbital fibroblasts with gamma-interferon. Interleukin-1 inhibited DNA synthesis in orbital fibroblasts but stimulated DNA synthesis in dermal fibroblasts (P < 0.01); tumour necrosis factor also displayed a differential effect (P < 0.01). Hypoxia caused a significant increase in glycosaminoglycan, protein and DNA synthesis in both types of fibroblasts, under both basal and cytokine-treated conditions (P < 0.05). CONCLUSIONS: Extraocular muscle fibroblasts respond differently from dermal fibroblasts following cytokine stimulation, which may explain in part the anatomical localization of ophthalmopathy. Hypoxia stimulates fibroblasts and this could contribute, as an enhancing factor, to the adverse effects of smoking on thyroid eye disease.     

Suppression of prostaglandin E receptor signaling by the variant form of EP1 subtype

A cDNA clone of prostaglandin (PG) E receptor EP1 subtype (rEP1) was isolated from a rat uterus cDNA library. It encodes 405 amino acid residues with seven transmembrane-spanning domains and couples to Ca2+ mobilization. In addition, three cDNA clones encoding a variant form of rEP1 were isolated. The open reading frame can code a 366-amino acid protein carrying a specific change of 49 amino acids from the middle of transmembrane segment VI to COOH terminus; it possesses a transmembrane segment VII-like structure lacking an intracellular COOH-terminal tail. Southern blot analysis of rat genomic DNA and genomic polymerase chain reaction demonstrated that these cDNAs were derived from a single copy gene. Northern blot analysis and ribonuclease protection assay revealed that both rEP1 and rEP1-variant receptor mRNAs were highly expressed in the kidney. Immunoblot with an antibody directed toward the specific region of rEP1-variant receptor showed that rEP1-variant receptor protein was expressed in the membrane of the kidney and Chinese hamster ovary (CHO) cells transfected with rEP1-variant cDNA. Thus, the rEP1-variant receptor is translated from mRNA which is not spliced at nucleotide position 952 in the segment VI transmembrane region. rEP1-variant receptor retained the ligand binding activity with affinity and specificity similar to rEP1 receptor, but lost the coupling of signal transduction systems by itself. However, when rEP1-variant receptor was stably co-expressed with rEP1 receptor in CHO cells, the Ca2+ mobilization mediated by EP1 receptor was significantly suppressed. Furthermore, when rEP1-variant receptor was expressed in CHO cells, cAMP formation by activation of endogenous EP4 receptor was strongly blocked. These results suggest that the rEP1-variant receptor may affect the efficiency of signal coupling of PGE receptors and attenuate the action of PGE2 on tissues.     

Positive association between dietary fat intake and risk of gastric stump carcinoma in rats

Effect of high- and low-fat diets on gastric stump carcinogenesis was experimentally investigated. A total of 130 Wistar male rats weighing 250-300 g received either sham operation or Billroth II partial gastrectomy, the resection of the distal two-thirds glandular stomach and reconstruction of gastro-jejunostomy. After surgery, each group of rats was switched from a standard diet (CRF-1) to a special diet containing either 15% soybean oil (high-fat) or 0.5% soybean (low-fat), fed ad libitum and tap water, and were killed 50 weeks after surgery. Gastric tumours were observed only in the animals that underwent gastrectomy while no tumours were detected in the animals following the sham operation. Tumours located invariably at the gastrojejunostoma, were carcinomas or adenomas in histology. Carcinomas developed in 12 of 29 gastrectomy animals (41%) fed the high-fat diet and 4 of 27 gastrectomy animals (15%) fed the low-fat diet. The difference was significant (P < 0.05). The incidence of adenoma was also significantly higher in the gastrectomy animals fed the high-fat diet (38%) than that in those fed the low-fat diet (15%) (P < 0.05). A daily faecal output of bile acids was significantly greater in the gastrectomy animals fed the high-fat diet (19.0 +/- 16.4 micromol/day) than that in those fed the low-fat diet (11.2 +/- 6.2 [micromol/day; P < 0.05). This study suggests that increased fat intake is associated with a high risk of gastric stump carcinoma.     

Plant designing of ion exchange chemical uranium enrichment and its non-proliferation aspects

The chemical uranium enrichment using ion exchanger had been developed mainly in Japan, but now only the academic studies have been continued at Tokyo Tech. For the purpose of revaluation as the alternative production process of the low enriched uranium for nuclear power plants, the plant design and the non-proliferation aspects of redox ion exchange chemical uranium enrichment (Redox Ion Exchange Method) were studied.The conceptual design of a commercial enrichment plant with a scale of 1400 tSWU/Y was newly performed based on data reported. It is composed of seven enrichment units with two enrichment columns with an inner diameter of 6.5 m and a height of 11 m and redox systems. It is evaluated as having the site area of 97,200 m² including the vacancy to double the production with subsidiary sections of pre-treatment and post-treatment of uranium or the like, a construction cost is 218 billion Japanese yen(JPY), and a cost per enrichment work is 18,000 JPY/kgSWU. As for the nuclear proliferation resistance of this process, it is suggested that the production of highly enriched uranium for weapon use is difficult from the view point of nuclear fission criticality and the lengthy equilibrium time mentioned as following. It is difficult to operate the enrichment plant for the production of highly enriched uranium of 50 wt% of ²³⁵U or higher, because the effective neutron multiplication factor (k_eff) in the enrichment columns becomes 1 or above depending on the enrichment conditions. And the required time for the production of highly enriched uranium of 90 wt% of ²³⁵U is estimated 10 thousands days or more, this means substantially impossible to get highly enriched uranium under the safeguard of IAEA by the Redox Ion Exchange Method.The Redox Ion Exchange Method is suggested to be a promising candidate for an alternative enrichment process to obtain low enriched uranium in the range 3-5 wt% ²³⁵U for nuclear power plant in the world. Furthermore, for the future prospective fuel cycle without UF₆, new front-end system coupled with uranium from seawater and chemical enrichment is proposed.     

Identification of activity stop locations in GPS trajectories by density-based clustering method combined with support vector machines

The identification of activity locations in continuous GPS trajectories is an essential preliminary step in obtaining person trip data and for activity-based transportation demand forecasting. In this research, a two-step methodology for identifying activity stop locations is proposed. In the first step, an improved density-based spatial clustering of applications with noise (DBSCAN) algorithm identifies stop points and moving points; then in the second step, the support vector machines (SVMs) method distinguishes activity stops from non-activity stops among the identified stop points. A time sequence constraint and a direction change constraint are applied as improvements to DBSCAN (yielding an improved algorithm known as C-DBSCAN). Then three major features are extracted for use in the SVMs method: stop duration, mean distance to the centroid of a cluster of points at a stop location, and the shorter of distances from current location to home and to the workplace. The proposed methodology was tested using GPS data collected from mobile phones in the Nagoya area of Japan. The C-DBSCAN algorithm achieves an accuracy of 90 % in identifying stop points in the first step, while the SVMs method is 96 % accurate in distinguishing the locations of activity stops from non-activity stops in the second step. Compared to other variants of DBSCAN used to identify activity locations from GPS trajectories, this two-step method is generally superior.

     

Vibration-assisted upconversion of molecular luminescence induced by scanning tunneling microscopy

We investigate the effects of coupling between a molecular exciton, which consists of an electron and a hole in a molecule, and a surface plasmon (exciton-plasmon coupling) on the electron transitions of the molecule using nonequilibrium Green’s function method. Due to the exciton-plasmon coupling, excitation channels of the molecule arise in the energy range lower than the electronic excitation energy of the molecule. It is found that the electron transitions via these excitation channels give rise to the molecular luminescence and the vibrational excitations at the bias voltage lower than the electronic excitation energy of the molecule. Our results also indicate that the vibrational excitations assist the emission of photons, whose energy exceeds the product of the elementary charge and the bias voltage, (upconverted luminescence).     

Sex Pheromone Components of the Pear Fruit Moth, <Emphasis Type="Italic">Acrobasis pyrivorella</Emphasis> (Matsumura)

We analyzed the sex pheromone of the pear fruit moth, Acrobasis pyrivorella, by means of gas chromatography–electroantennographic detection (GC-EAD) and GC–mass spectrometry. Two EAD-active compounds were detected in the pheromone gland extract of females. They were identified as (Z)-9-pentadecenyl acetate (Z9-15:OAc) and pentadecyl acetate (15:OAc). The amounts per female gland (mean ± standard error) of these compounds were 12.9 ± 2.8 and 0.8 ± 0.1 ng, respectively. Synthetic Z9-15:OAc (300 μg) attracted conspecific males in field trapping experiments. When 15:OAc (21 μg; 7% of Z9-15:OAc quantity) was added, the number of males trapped increased significantly. Catch in traps baited with the mixture of these compounds was greater than that in traps baited with 1–3-day-old virgin females. We, therefore, conclude that Z9-15:OAc and 15:OAc are sex pheromone components of this species.