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Temperature (T)-dependence of electrical resistivity (µ) and magnetization curves have been observed for Fe and Si nano-particle (NP) composite assemblies prepared using a double-source-plasma-gas-condensation cluster deposition system. With increasing T, µ monotonically decreases for the Fe composition, cFe 0.6, where the Fe NP networks are formed (a metallic conduction). With increasing cFe, saturation magnetization monotonically increases, while magnetic coercivity increases for cFe 0.6. In these Fe and Si NP composite assemblies, magnetic dipole interactions between Fe NPs are reinforced by reductions in inter-particle distances though they are averaged by random configurations of Fe and Si NPs, and random orientations of magnetic moments of Fe NPs. Magnetic exchange interactions are also induced but not much enhanced with cFe due to loose contacts between Fe NPs. [doi:10.2320/matertrans.M2014434]

Random assemblies of Fe and Si clusters have been prepared using a dual source plasma gas condensation cluster deposition system and their conductivities were measured for various compositional ratios. The size distributions of Fe and Si clusters are obtained by transmission electron microscopy (TEM) observations and the volume fraction of Fe clusters, f Fe , is estimated from the chemical analysis and packing fraction of cluster assemblies. Electrical conductivity, a, of Fe and Si cluster assemblies obeys a power law of f Fe . The dramatic change at around f Fe = f c , indicates that the percolation of Fe clusters takes place at the threshold value, f c = 0.16. It is consistent with the Links-Nodes-Blobs model calculated for a three dimensional percolation network.

最長24週間リン酸緩衝液中に浸漬したポリ (L-乳酸) の破壊靭性を計測し, 破壊靭性に及ぼす加水分解の影響について調べた. その結果, 非晶化試料と結晶化試料ともに加水分解の影響を受け破壊靭性は次第に低下するが, 結晶化試料の方が低下率は大きく, 加水分解試験開始後わずか1週間で破壊靭性は大きく低下した. 加水分解試験後の試料ならびに破面の顕微鏡観察の結果, 加水分解による分子鎖の切断が原因と考えられる球晶界面でのき裂生成などの劣化が生じ破壊靭性が低下したことが明らかになった.

Poly (lactic acid) was molded under four different kinds of condition to obtain samples with different microstructures. A single crystal was not observed in the specimen molded at 0°C. The size of spherulites became larger with increase of molding temperature. The density of spherulites increased with increase of molding time. Mode I fracture toughness, KIC was measured at a static (1 mm/min) and an impact loading rate (1 m/s). KIC became lower with increase of degree of crystallization at the static loading rate. This is mainly due to suppression of craze formation in the vicinity of crack-tip. On the other hand, at the impact loading rate, KIC increased with increase of degree of crystallization. Thus, the results showed that crystallization has significant influence on KIC, and its effect on the static KIC was different from that on the impact one. Relationship between fracture toughness and fracture micromechanism was discussed on the basis of the results of fracture tests and microscopies.

Cell growth of anaerobic protozoan Tritrichomonas foetus was analyzed. This protozoan usually proliferates in extremely high density, but protozoan parasites were dispersed uniformly in F-bouillon medium and cell division stopped temporarily. However, nuclear fission continued and giant polynucleated cells formed. Later, cell division resumed and cells returned to normal form. In conditioned medium, cytokinesis of the dispersed parasites did not stop. Results indicated that T. foetus cells secreted an extra-cellular factor that influenced cytokinesis.

Objective: To determine the safety and usefulness of antegrade hypothermic cerebral perfusion in conjunction with mild hypothermic (tepid) visceral perfusion (so-called cool head‐warm body perfusion; CHWB) in aortic surgery; the clinical outcomes and perioperative data on this new technique were retrospectively analyzed. Methods: From January 1990 to March 1999, 59 patients underwent ascending aorta or aortic arch surgery using antegrade selective cerebral perfusion (SCP). Three perfusion techniques, differentiated by perfusion temperature, were used, those being deep hypothermia (DH; nasopharyngeal temperature of 208C, na 14), moderate hypothermia (MH; nasopharyngeal temperature of 288C, na 17) and CHWB (nasopharyngeal temperature of 258C and bladder temperature of 328C, na 28). Selection of the technique largely followed a chronological pattern, in this order: DH, MH and, more recently, CHWB. The three groups were retrospectively compared in terms of operative outcome, duration of cardiopulmonary bypass (CPB) and operation, and intraoperative blood loss. Results: The early (within 30 days after surgery) mortality/hospital mortality (including operative mortality) was 7.1/21.4, 5.9/11.8 and 3.6/7.1% in the DH, MH and CHWB groups, respectively. The rate of stroke was 7.1, 6.3 and 3.6% in the DH, MH and CHWB groups, respectively. No statistical difference was found in early or hospital mortality, or in the rate of stroke among the three groups. The CPB time, especially the time for rewarming, was significantly shorter in the CHWB than in the DH group. Likewise, the operation time, especially the time after CPB, was significantly shorter in the CHWB than in the DH and MH groups. Blood loss was significantly less in the CHWB than in the DH group. Conclusion: Our data suggest that CHWB perfusion in aortic surgery is a safe and useful technique in shortening the operation time and reducing blood loss, but further prospective study is necessary. q 2000 Elsevier Science B.V. All rights reserved.

The non-specific immunostimulation and adjuvant effects of Vibrio anguillarum bacterin (VAB), M-glucan, chitin and Freund's complete adjuvant (FCA) against pasteurellosis were examined in yellowtail, Seriola quinqueradiata. Control fish were injected intraperitoneally with 0.1 ml of sterile phosphate buffered saline (PBS). Experimental fish were injected similarly with either vaccine (lipopolysaccharide-mixed chloroform-killed Pasteurella piscicida, LPS-CKC), an immunostimulant or mixture of the vaccine and an immunostimulant.All fish were subsequently challenged by the same but live P. piscicida strain using an immersion method at 15, 25, 35 and 45 days post-inoculation. Immunostimulants alone were found to slightly increase the protectionagainst Pasteurella infection, but the effects were not statistically significant. The most effective adjuvant wasFCA, however the enhanced protection was not statistically different from that of fish inoculated with LPS-CKCalone. However, the relative percent survival (RPS) of fish vaccinated with M-glucan, chitin or Vibrio bacterinas adjuvant was lower than that of fish vaccinated with only LPS-CKC bacterin alone. Thus, M-glucan, chitin and Vibrio bacterin had no positive adjuvant effects on the P. piscicida vaccine.

Sn and Pb-Sn plating steels are generally used as solderable outer-packaging materials for electrical machinery. Short-circuiting of electric machine parts due to the growth of Sn whiskers and the adverse influence of poisonous Pb on the environment arising with such materials have become increasingly serious problems.Electrogalvanized steels have been used as replacements even though their solderability is not as good as that of Sn and Pb-Sn plating steels.To improve solderability, we have studied Ni, Fe, and Sn preplating on electrogalvanized steels. In this report, we investigated solder spreadability, wettability, and peeling strength.Ni or Fe preplating under the Zn plating layer effectively improved solderability. Ni preplating showed a particularly excellent value for solder peeling strength.It was found that, while Zn gradually dissolved in solder, preplated Ni or Fe did not. This prevented the surface of the base steel from being exposed. Ni or Fe also formed Ni3Sn2, Ni3Sn, or FeSn2 with solder. These improve steel solderability.

Metal molds and machine parts for die-casting need excellent corrosion resistance against molten metals. In this study, we investigated corrosion resistance of various kinds of boride base hard materials ( Mo2FeB2-Fe, Mo2NiB2-Ni, WCoB-Co, W-Mo2NiB2-TiB2 base cermets and TiB2 ceramic ) against a molten Al alloy (JIS ADC10), a Zn alloy (JIS D-2) and soft solders (JIS H5A and H70A). The corrosion resistances of these materials were estimated by measuring the dimensional changes after dipping in the molten metals.The results indicated that the boride base hard materials, especially TiB2 containing materials had higher corrosion resistance than. conventional materials, such as WC-20mass%Co, SKD61 and SK1151. SEM micrographs showed that the binder phases comprising Fe, Co and Ni in the boride base hard materials react with the molten metals, prior to the boride phase. The boride base hard materials are consequently promising candidates for the die-casting machine parts and molds.

BACKGROUND Hypothermia has been an essential technique in aortic arch surgery for protecting the brain. To reduce the adverse effect caused by hypothermia, we modified the perfusion technique in aortic arch surgery. Initial results using this modified technique are reviewed. METHODS Nineteen patients were operated on for aortic aneurysm involving the aortic arch. Fifteen patients had nondissecting aneurysm and four patients had type A dissecting aneurysm including three with acute dissection. While on the hypothermic (25 degrees C to 28 degrees C of nasopharyngeal temperature) antegrade selective cerebral perfusion (SCP) was performed by direct cannulation to the brachiocephalic and left common carotid arteries, visceral perfusion via the femoral artery or graft was performed with tepid or normothermia (34 degrees C to 36 degrees C). RESULTS Hospital mortality rate was 5.3% (1/19 patients). None of the 19 patients suffered from stroke postoperatively. Duration of total cardiopulmonary bypass and SCP was 144 +/- 36 minutes and 90 +/- 34 minutes, respectively. Eighteen surviving patients were extubated at 9.4 +/- 13.2 hours and stayed in the intensive care unit (ICU) for 3.0 +/- 1.8 days after the surgery. CONCLUSIONS Our initial experience revealed that the modified technique using simultaneous hypothermic cerebral perfusion and tepid or normothermic visceral perfusion can be a useful adjunct during aortic arch surgery providing quick recovery.

To establish a safe and reliable method for cerebral protection in aortic arch surgery, the authors attempted antegrade selective cerebral perfusion (SCP) based on the characteristics of jugular venous oxygen saturation (SjO2). Twenty patients were divided into two groups: a control group and SCP group. In the control group, in 13 adult patients undergoing cardiac surgery using standard hypothermic cardiopulmonary bypass, the relationship between SjO2 and nasopharyngeal temperature (NPT) during rewarming showed an inverse linear correlation:SjO2 = -2.3 NPT + 133 (r = 0.616). In the SCP group, seven patients with aortic arch aneurysm underwent surgery using SCP performed through direct cannulation of the innominate and left carotid arteries. While on SCP (83 +/- 24 min), the blood was warmed from 28 to 36 degrees C. Cerebral perfusion pressure of 40-60 mm Hg was necessary to maintain the SjO2 equal to the value in the control group at each NPT during SCP in all seven patients. None of the patients had any post operative complications. Our experience suggests that SCP can be safely performed at both mild hypothermia and normothermia under monitoring of perfusion pressure and SjO2 in aortic arch surgery.

To clarify the formation mechanism of work-hardened surface layer introduced at the time of abrasive working, (001) single crystal surfaces of Cu were scratched with diamond cone styluses, and the examinations were made around the end of scratch-grooves and also around the cross and vertical-sections of grooves by means of X-ray microbeam technique, TEM, etching and micro-hardness measurements. It was found that the three dimensional extent of deformed region around the groove varies with the scratch direction. And from the analysis of Laue asterisms on X-ray diffraction patterns, the distribution of the activated slip systems contributing to the scratch deformation was estimated. The explanation was made about the work-hardening process around the groove considering the interactions of each slip deformation processes. The dislocation structure near the surface of groove end shows the corresponding variation to the deformation processes, and besides, the anisotropy of hardness distribution beneath the groove can be explained from the difference of the deformation processes.

The third case of infant botulism in Japan is reported. A four-month-old baby boy suddenly had weakness of suckling force, constipation and generalized hypotonicity. He was the product of normal gestation, labor and delivery. Growth and development were normal until he was nineteen weeks old. He received fruit-juice and honey daily. By bacteriological examination, Clostridium botulism type A was isolated from his feces and the honey which he had received. Type A toxin was detected from his feces but not from his serum.

An outbreak of acute enteritis in children aged one to thirty-three months occurred from June 10th to 23rd, 1986, at a private orphanage in Matsuyama City. Twenty-two out of 23 children suffered from diarrhea. Nine of the 22 children excreted bloody stool. Fever and vomiting were observed with a few patients. One of them, a 33-month-old girl, developed hemolytic uremic syndrome, and died twelve days after the admission. Escherichia coli O111:H- was isolated from fecal specimens of 7 out of 15 patients. The culture filtrate of the isolate caused fluid accumulation in ligated ileal loops in a rabbit, and was lethal to mice. It was found that all isolates produced two kinds of Vero toxins (VT1 and VT2, or shiga-like toxin I and II). The amount of VT2 produced in vitro was about 10 times more than that of VT1.

Since periodical survey of the sewage entering the sewage-farm in Matsuyama City revealed a high incidence of Salmonella typhi of different phage types, attempts were made to trace the upstream reservoir. It was found that S. typhi was drained into a particular manhole at a distance of about 5 km from the sewage-farm. Two members of two families were found to be carriers. Further investigation detected other 25 carriers. The 27 carriers were all pupils of the same primary school. Ten of them showed mild symptoms such as fever, abdominal pain and diarrhea; the remaining 17 were asymptomatic. The phage type of 24 isolates was of Vi degraded approaching phage type A [degraded Vi(A)] and that of the other three was of type 53. The results coincided with those of the isolates from sewage.