Investigation of Ag and Cu Filament Formation Inside the Metal Sulfide Layer of an Atomic Switch Based on Point-Contact Spectroscopy.

The atomic switches have attracted wide attention owing to their applications in nonvolatile electric devices. The atomic switch is operated by the formation and dissipation of a metallic filament inside a metal sulfide film, which is controlled by a solid electrochemical reaction. Although the metallic filament is considered to consist of metal atoms, the chemical species of the metallic filament are difficult to be identified due to challenges in observing the metallic filament inside the solid. In this study, we report the investigation on the metallic filament in the atomic switch with metal sulfide based on point-contact spectroscopy (PCS). By cooling the atomic switch, the switch voltage increased to 1 V, which allowed for the PCS measurement. The PCS revealed that the metallic filament was composed of Ag atoms in the case of the Pt/Ag2S/Ag atomic switch. We applied this technique to the Pt/Cu2S/Ag and Pt/Ag2S/Cu atomic switches to uncover the formation process of the metallic filament. In both atomic switches, the chemical species of the metallic filament were Ag. The metal atoms were supplied from both the metal electrode and the sulfide layer.

Investigation on the formation process of metal atomic filament for metal sulfide atomic switches by electrical measurement.

We have studied the formation process of the metal atomic filament for metal sulfide atomic switches by electrical measurement. The switching between ON and OFF states of the atomic switch is controlled by the application of the bias voltage for the atomic switches. The SET (OFF â†’ ON) and RESET (ON â†’ OFF) voltages were investigated for the atomic switch where the Ag2S or Cu2S layer were sandwiched between the Pt and Ag or Cu electrodes. The SET and RESET voltages of the Ag/Cu2S/Pt and Cu/Ag2S/Pt were close to those of the Ag/Ag2S/Pt atomic switch, and different from those of the Cu/Cu2S/Pt atomic switch. These results indicated that the dominant chemical species of the making and breaking part of the metal filament was Ag, and that the source of the metal filament was both the sulfide layer and the metal electrode.

Clinical results of modified Mitchell's osteotomy for hallux valgus augmented with oblique lesser metatarsal osteotomy.

PURPOSE: To evaluate postoperative results of modified Mitchell's osteotomy and its combination with oblique metatarsal osteotomy for the treatment of hallux valgus. METHODS: A total of 93 feet of 53 patients (2 men and 51 women) with hallux valgus underwent modified Mitchell's osteotomy and were followed up for at least 5 years. Patients' age ranged from 17 to 83 years, and the duration of follow-up ranged from 5 years one month to 18 years 4 months. Modified Mitchell's osteotomy was performed on 53 feet in 31 patients (group A), whereas modified Mitchell's osteotomy augmented with oblique lesser metatarsal osteotomy was performed to the remaining 40 feet in 22 patients (group B). Postoperative results were assessed using a clinical assessment system developed by the Tokyo Medical University based on 5 categories: pain in the first metatarsophalangeal, deformity of the metatarsophalangeal, plantar callosity and/or metatarsalgia of lesser metatarsals, the use of commercially available shoes, and local inflammatory symptoms. RESULTS: Mean total score improved from 3.8 to 7.9 on a 10-point scale. Scores for 2 categories--plantar callosity and/or metatarsalgia and the use commercially available shoes--were significantly higher in group B at postoperative 5 years. Before surgery, at postoperative 3 weeks, and at postoperative 5 years, respectively, the mean hallux valgus angles were 34.2, 12.0, and 17.1 degrees; mean M1-M2 angles were 16.7, 7.4, and 8.7 degrees; mean M1-M5 angles were 34.9, 25.8, and 26.6 degrees; and mean sesamoid bone shifts were 8.7 mm, 4.3 mm, and 5.9 mm. CONCLUSION: Modified Mitchell's osteotomy shortens the length of the first metatarsal bone and thus relieves tension in soft tissues such as the adductor hallucis. Nonetheless, the procedure can induce metatarsophalangeal joint malalignment and metatarsalgia, and plantar callosity may develop or persist after surgery. Combining oblique metatarsal osteotomy of the lesser metatarsal bones is useful in patients with uneven metatarsal bone lengths and metatarsophalangeal joint malalignment.

Platelet-activating factor antagonist, SM-12502, attenuates experimental glomerular thrombosis in rats.

Platelet-activating factor (PAF) is involved in many pathologic conditions through its potent proinflammatory and vasoactive effects. Using a specific PAF antagonist, SM-12502, we investigated the role of PAF in rat experimental glomerular thrombosis. In this model, sequential injections of nephrotoxic serum (NTS) and lipopolysaccharide (LPS) selectively induce glomerular fibrin deposition accompanied by neutrophil accumulation. SM-12502, when injected simultaneously with either NTS or LPS, strongly inhibited glomerular fibrin deposition in a dose-dependent manner. In contrast, neutrophil invasion was similar in both SM-12502-injected and uninjected rats, suggesting that the antithrombotic effect was not mediated by inhibition of neutrophil migration. However, serum myeloperoxidase activity, a marker of neutrophil activation, was significantly suppressed by treatment with SM-12502. From a previous finding supporting the indispensable role of neutrophils in this model and the current observations, SM-12502 is suggested to attenuate glomerular thrombosis by inhibiting neutrophil activation. Thus, the present findings suggest an involvement of PAF in this glomerular thrombosis model.

Treatment of adult Still's disease with dexamethasone, an alternative to prednisolone.

We successfully treated three cases of adult Still's disease (ASD) with dexamethasone. High dose prednisolone, which was initially used to treat these patients, failed to remit the disease in all cases. Although they were resistant to prednisolone, all these patients had remarkable improvements in clinical and laboratory findings after switching to an equivalent dose of dexamethasone. We propose using dexamethasone as an alternative for treating ASD before adding immunosuppressants or disease modifying anti-rheumatic drugs (DMARD), when prednisolone therapy does not suppress disease activity sufficiently.

Therapeutic effects of ulinastatin on experimental crescentic glomerulonephritis in rats.

Ulinastatin is a potent protease inhibitor purified from the human urine that has been used clinically to treat acute pancreatitis and circulatory shock. In the current study, we evaluated the therapeutic effects of Ulinastatin in a rat model of crescentic glomerulonephritis (CrGN) and investigated its putative mechanisms. Wistar-Kyoto rats were injected with nephrotoxic serum and received daily intraperitoneal injection of Ulinastatin. Ulinastatin treatment significantly reduced proteinuria and glomerular crescentic formation. Moreover, glomerular infiltration of neutrophils and ED1+ cells (monocytes/macrophages) was significantly suppressed by Ulinastatin. In contrast, the glomerular deposition of heterologous (rabbit) and autologous (rat) antibodies was not changed. Neither serum complement activation nor the anti-rabbit immune response was affected by Ulinastatin administration. Our results suggest that Ulinastatin has preventive effects on rat experimental CrGN, mediated at least in part by inhibiting intraglomerular infiltration of inflammatory cells.

A case of bilioduodenal fistula treated with a self-expandable metallic stent.

We report the case of a 72 year-old female patient who suffered from biliary fistulae. The biliobiliary and bilioduodenal fistulae appeared after an operation for biliary bleeding. Conventional therapy for biliary fistula would be the disconnection of the fistula by either conservative or operative treatment. In the present case, however, it was preferable to enlarge the fistula to drain bile juice into the duodenum, rather than to close the fistula because it would have been difficult to achieve a tight adhesion with this operation. The enlargement by a plastic tube stent failed to drain the bile juice into the duodenum, because the sludge made the tube stenotic. Therefore, a self-expandable metallic stent was applied in this case. An expandable stent was used because a large final caliber is necessary to prevent stenosis of the fistula by sludge and mucosal hyperplasia. After insertion of a self-expandable metallic stent by the percutaneous transhepatic biliary drainage route, the patient has not suffered from cholestasis and cholangitis for the last 30 months. It can therefore be concluded that enlargement of the fistula by a self-expandable metallic stent is a convenient therapy for such biliointestinal fistulae.

[Diagnosis of prosthetic mitral valve regurgitation by Doppler color flow imaging using right parasternal approach: a comparative study with transesophageal method].

Doppler color flow imaging is a useful tool in evaluating mitral regurgitation (MR). However, it is frequently difficult to assess prosthetic valve MR by the conventional transthoracic approach using left parasternal or apical echo-windows, because of the interception of ultrasound by the prosthesis or artifacts produced by its motion. The purpose of this study is to determine the usefulness of the "right" parasternal approach (RPA) in the echo diagnosis of prosthetic MR. Six patients with pathological prosthetic MR determined by transesophageal approach (TEA) were studied. Transthoracic echo was performed using both the RPA and the conventional approach, and the presence or absence and the extent of MR signals by these transthoracic approaches were compared with those by TEA. Prosthetic MR was detected in five of six patients by the RPA and the extent of MR signals by the RPA was very similar to that by TEE in each of the five patients. MR could not be detected by the RPA only in one patient, whose MR was estimated to be very mild by TEE. By the conventional approach, MR could not be detected in three patients and the degree of MR was significantly underestimated in two of the remaining three patients. Thus, the transthoracic RPA is often as useful as TEA in diagnosing prosthetic MR, which is often undetectable or underestimated by the conventional approach. Because the RPA is less invasive than TEA, the RPA should be encouraged in patients with suspected prosthetic mitral valve dysfunction.

[Efficacy of UFT in advanced gastric carcinoma under comparative study of MMC + UFT and MMC + tegafur therapies].

Antitumor effect of MMC + UFT(A) and MMC + tegafur(B) therapies for advanced gastric carcinoma was compared from February 1985 to March 1988. UFT and tegafur were orally given at dose of 400 mg/m2 daily, and MMC was intravenously administered at dose of 6-8 mg/m2 every two weeks. The following results were obtained. 1. Twenty-nine cases entered in this study were divided into A or B therapies at random. All cases entered were eligible. Fourteen of 29 cases were randomized into A therapy and 15 cases into B therapy. One case treated with B was evaluated as incomplete. 2. There were no differences in the characteristics of patients between A and B therapies. 3. Among 29 eligible cases, a partial response was obtained in 3 out of 14 cases (21.4%) treated with A and in 3 out of 15 cases (20.0%) treated with B. Among 28 cases evaluated completely, a partial response was obtained in 3 out of 14 cases (21.4%) treated with each A and B. 4. Response rate with every ps or for every lesion did not differ between A and B therapies. 5. Median survival day treated with A and B therapies was 223 and 181 days, respectively. The survival curve did not differ significantly between the two therapies. 6. The frequency of adverse reactions within eight weeks after beginning the therapy was 64.2 and 73.3% with A and B therapies, respectively. From the results mentioned, it was concluded that the antitumor effect of UFT was not superior to that of tegafur for advanced gastric carcinoma.

Intussusception of the appendix with a calcified fecalith.

We treated a patient with a complete invagination of the appendix which contained one large laminated calcified fecalithy. Colonofiberscopy showed a dimpling submucosal tumor, which was palpated as a bony hard tumor at laparotomy. This finding suggested that the fecalith caused an intussusception of the appendix and that such an intussusception should be suspected when there is a bony hard dimpling submucosal tumor in the cecum.