The Encounter with Aori-ika, and Meeting with Remarkable Persons in the University

東京海洋大学名誉教

Ambipolar transport in bulk crystals of a topological insulator by gating with ionic liquid

We report that the ionic-liquid gating of bulk single crystals of a topological insulator can control the type of the surface carriers and even results in ambipolar transport. This was made possible by the use of a highly bulk-insulating BiSbTeSe2 system where the chemical potential is located close to both the surface Dirac point and the middle of the bulk band gap. Thanks to the use of ionic liquid, the control of the surface chemical potential by gating was possible on the whole surface of a bulk three-dimensional sample, opening new experimental opportunities for topological insulators. In addition, our data suggest the existence of a nearly reversible electrochemical reaction that causes bulk carrier doping into the crystal during the ionic-liquid gating process.Comment: 7 pages, 6 figures, 2 tables; significantly expanded version to fully discuss the gating process and its side effects; published in PR

Early Ontogeny of the Japanese Common Squid Todarodes pacificus (Cephalopoda, Ommastrephidae) with Special Reference to its Characteristic Morphology and Ecological Significance

Early ontogeny of the Japanese Common Squid Todarodes pacificus was described for artificially inseminated and collected specimens to present new criteria for developmental stages in relation to its ecological adaptation. For the purpose, details for formation of the following organs and tissues were observed with special attention: cilia on the integument, mouth part, shell sac and stellate ganglia, visceral mass, funnel-collar complex, statocysts, eye parts, and ventral photosensitive vesicles. At the embryonic stage (i.e., pre-hatching), various types of epidermal cilia that seem to work as the embryonic rotation were detected. At the early postembryonic stage (i.e., post-hatching), the epidermal lines were characteristically arranged at the scattered condition on arms, tentacles, head, and funnel. Novel strong muscle fibers were distinct in the base of tentacles and funnel retractor muscles at the early postembryonic stage, which is clearly related to the head withdrawal behavior of the paralarvae. The lip cilia and toothed beak developed at the early postembryonic stage, but disappeared later; these apparatus were considered to be related with a change of unique feeding mode in the paralarval life. Based on such morphological features, four distinct stages, namely, paralarval stage 1, 2, 3, and juvenile stage are proposed. The present observations are discussed in relation to survival strategy at early life of T. pacificus and they are compared with those in other cephalopods

The effect of nitric oxide synthase inhibitor on reperfusion injury of the brain under hypothermic circulatory arrest

AbstractObjective: The objective of this study was to investigate the protective effects of nitric oxide synthase inhibitor, Ng-nitro-l-arginine methyl ester hydrochloride, on reperfusion injury of the brain under hypothermic circulatory arrest. Methods: After cardiopulmonary bypass was established using 12 piglets each weighing about 30 kg, the animals were cooled to a brain temperature of 20° C and circulatory arrest was performed for 90 minutes followed by reperfusion for 120 minutes. The level of nitric oxide within the brain was measured with a needle electrode inserted into the brain. In the treatment group, Ng-nitro-l-arginine methyl ester hydrochloride was administered with an intravenous injection of 1.5 mg/kg at the onset of the reperfusion followed by a 60-minute continuous venous infusion of 1.5 mg/kg/hr. Results: In the control group, nitric oxide levels within the brain increased not during ischemia but during reperfusion, and the level after 120 minutes of reperfusion increased significantly compared with that of before circulatory arrest. But in the treatment group, Ng-nitro-l-arginine methyl ester hydrochloride administered at the onset of reperfusion inhibited nitric oxide production during reperfusion. A significant difference was observed between the groups regarding the nitric oxide level after 120 minutes of reperfusion. Regarding cerebral blood flow, excess lactate, and cerebral tissue water content, no significant difference was observed between the groups. However, recovery of somatosensory evoked potential after 120 minutes of reperfusion was detected in all six animals in the treatment group, but none in the control group (p = 0.001). Conclusion: These data suggest that Ng-nitro-l-arginine methyl ester hydrochloride protects the brain against reperfusion injury under hypothermic circulatory arrest. (J Thorac Cardiovasc Surg 1998;115:925-30

Electrochemical synthesis and superconducting phase diagram of Cu_xBi2Se3

The superconducting Cu_xBi_2Se_3 is an electron-doped topological insulator and is a prime candidate of the topological superconductor which still awaits discovery. The electrochemical intercalation technique for synthesizing Cu_xBi2Se3 offers good control of restricting Cu into the van-der-Waals gap and yields samples with shielding fractions of up to ~50%. We report essential details of this synthesis technique and present the established superconducting phase diagram of T_c vs x, along with a diagram of the shielding fraction vs x. Intriguingly, those diagrams suggest that there is a tendency to spontaneously form small islands of optimum superconductor in this material.Comment: 6 pages, 4 figure

Biliary ICG Concentrations as an Indicatr of the Effect of Biliary Decompressions : Peak and two-hour ICG Concentrations

To quantitate the effects of biliary decompression on hepatic functional reserve prior to a definitive operation in patients with obstructive jaundice, indocyanine green (ICG) concentration in the bile was measured before and at 15 minute intervals for six hours following its administration. The maximal excretion rate of ICG in the bile as a function of time (ICG Bmax) was calculated by the following equation : ICG Bmax=loge (loge(10Xpeak concentration)] peak concentration time Determination of ICG Bmax has a shortcoming in that it requires prolonged restriction of the patients. Therefore, for the purpose of simplification, the natural logarithm of the ICG concentration two hours after ICG administration (ICG B2hr) was obtained : ICG B2hr=loge (biliary ICG concentration at two hours) There was a significant correlation between ICG Bmax and ICG B2hr\u27 with a correlation coefficient of 0.865 as determined in 131 subjects. ICG Bmax is a reliable indicator in the assessment of hepatic functional reserve in jaundiced patients after biliary decompression and prior to further surgical interventions ICG B2hr assessment is a simplified method of ICG Bmax assessment. ICG B2hr values of less than 0.5 are considered to be contraindication for surgery, with a high probability of prolonged jaundice and poor prognosis. Values of more than 0.5 indicate the advisability of surgery, while those between -0.5 and 0.5 also indicate this if there is a trend to improvement

Gender with marital status, cultural differences, and vulnerability to hypertension: Findings from the national survey for noncommunicable disease risk factors and mental health using WHO STEPS in Bhutan

Cardiovascular disease is the leading cause of death in the Kingdom of Bhutan. Thus, the early detection and prevention of hypertension is critical for reducing cardiovascular disease. However, the influence of sociocultural factors on vulnerability to hypertension needs further investigation. This study performed secondary data analysis on 1, 909 individuals in a cross-sectional study (the National survey for noncommunicable disease risk factors and mental health using World Health Organization (WHO) STEPS approach in Bhutan– 2014). Multivariate logistic regression demonstrated a significant association between gender with marital status and hypertension. Women had a higher odds ratio than men (Ref) when married (AOR: 1.27, 95% confidence intervals (CI): 1.23–1.31), and when separated, divorced, or widowed (AOR: 1.18, 95% CI: 1.12–1.26). People who speak the Tshanglakha language scored the highest odds (AOR: 1.24, 95% CI: 1.20–1.27), followed by Lhotshamkha (AOR: 1.09, 95% CI: 1.06–1.12) and Dzongkha (Ref) after adjusting for various social and biomedical factors. Additionally, tobacco use displayed decreased odds for hypertension. To promote the early detection and prevention of hypertension, these cultural factors should be considered even within small geographic areas, such as Bhutan. It is necessary to strengthen hypertension preventive strategies for people who speak Tshanglakha and Lhotshamkha. Furthermore, careful consideration should be given to preventing hypertension among adults aged 40 years or more, women who are married, separated, divorced, or widowed, and men who never married in Bhutan

Predictive Evaluation of the Effects of Biliary Decompression by Biliary ICG Clearance Test (ICG Bmax) for Patients with Obstructive Jaundice

To quantitate the effects of biliary decompression on hepatic functional reserve before operation in patietns with obstructive jaundice, we developed a new method of maximal hepatic removal of indocyanine green in the bile (ICG Bmax). This was calculated from the peak ICG concentration in the bile and the peak concentration time after its administration via antecubital vein using regression analysis. This study involved 13 normal controls and 26 jaundiced patients. ICG Bmax of the normal controls indicated more than 0.5. Among the jaundiced patients. 17 showed an ICG Bmax value of more than -0.5 early during biliary decompression and 87% of them satisfactorily tolerated further radical operation. The remaining patients in whom ICG Bmax initially showed less than -0.5, but 67% of them had an unfavorable outcome postoperatively. Six of the nine patients whose ICG Bmax was less than -0.5 prior to operation suffered severe postoperative complication, and three of whom died from hepatic failure. These results indicated that ICG Bmax evaluation during an early period of biliary decompression provided a reliable asseessment of the effects and a prediction of biliary drainage. ICG Bmax evaluation is also useful to the timely decision of radical operation

Seasonal variations in abundance of pico- and nano-plankton in Lagoon Notoro-ko adjacent to the southwestern Okhotsk Sea

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　国立極地研究所１階交流アトリウ

Population dynamics of Pseudocalanus newmani in the coastal area of southwestern Okhotsk Sea

第6回極域科学シンポジウム[OB] 極域生物圏11月16日（月）　国立極地研究所１階交流アトリウ