A quantitative analysis of a trace amount of hydrogen in high temperature heat-treated carbons

A technique to determine a trace amount of hydrogen in carbon materials heat-treated above 1000 °C was developed. Three types of carbons prepared from poly(furfulyl alcohol), poly(vinyl chloride) and mesophase carbon microbeads were heat-treated at various temperatures ranging from 1000 to 1800 °C. Then they were gasified by O₂ in a fixed bed flow reactor, and the H₂O gases formed during the gasification processes were carefully monitored with a Karl Fischer moisture analyzer. As a result, this method makes it possible to determine the hydrogen contents in the carbons down to three places of decimals as a weight percent and can detect even a trace amount of hydrogen as low as 0.002 wt.%. A possible chemical structure of carbon edge sites was also discussed based on the experimentally determined hydrogen contents.     

Desmin and troponin T are degraded faster in type IIb muscle fibers than in type I fibers during postmortem aging of porcine muscle

A novel approach was applied in this study to directly evaluate the effect of muscle fiber type on postmortem protein degradation. Porcine muscle fibers were isolated from longissimus muscle at day 1, 3, and 6 postmortem. Fibers were sorted by immunochemical myosin heavy chain isoform typing. Western blot analysis of fibers pooled separately into type I or IIb showed that the relative amounts of 39- and 50-kDa desmin degradation fragments at day 6, and 28- to 31-kDa fragments of troponin T fast type isoform (fTnT) at day 1 and 6 postmortem were higher in type IIb than in type I fibers. At day 6 troponin T slow type isoform (sTnT) was less degraded than fTnT in type I fibers. These results indicated greater rate and extent of proteolysis in type IIb than in type I fibers and higher susceptibility of fTnT to proteolysis than that of sTnT isoform.     

Ionic liquid enables simple and rapid sample preparation of human culturing cells for scanning electron microscope analysis

Ionic liquid is a kind of salt that stays in a molten state even at room temperature. It does not vaporize at all in vacuum and facilitates electrical conductivity to the sample surfaces for observations with a scanning electron microscope (SEM). In this study, we used an ionic liquid in SEM for the first time to observe fixed human culture cells. The condition for the cell culture using wrapping sheets and SEM settings were varied to elucidate the optimized protocol. Compared to samples prepared by the conventional way, the ionic liquid‐treatment of samples gave SEM images of the cellular ultra structures in more detail, enabling observation of microvilli that made bridges between separated cells. In addition, the ionic liquid treatment is less time consuming as well as less laborious compared with the conventional way that includes dehydration, drying, and conductivity treatments. Totally, we concluded the ionic liquid is a useful reagent for SEM sample preparation. Microsc. Res. Tech., 2011. © 2010 Wiley‐Liss, Inc.     

Mathematics based on incremental learning—Excluded middle and inductive inference

Learning theoretic aspects of mathematics and logic have been studied by many authors. They study how mathematical and logical objects are algorithmically “learned” (inferred) from finite data. Although they study mathematical objects, the objective of the studies is learning. In this paper, a mathematics whose foundation itself is learning theoretic will be introduced. It is called Limit-Computable Mathematics. It was originally introduced as a means for “Proof Animation”, which is expected to make interactive formal proof development easier. Although the original objective was not learning theoretic at all, learning theory is indispensable for our research. It suggests that logic and learning theory are related in a still unknown but deep new way.     

Amae in Japan and the United States: An exploration of a "culturally unique" emotion.

The experience of an emotion considered to be culturally unique (i.e., Japanese Amae) was tested in the United States, where there is no word to describe the concept. North American and Japanese participants read scenarios in which a friend made an inappropriate request (Amae), made no request, or made the request to another friend. Both American and Japanese participants felt more positive emotion and perceived the requester as feeling closer to them in the Amae condition than in the other two conditions. However, Americans felt more in control when asked for a favor than when not asked, a pattern that did not emerge among the Japanese. Cultural specificity of hypocognized emotions is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Role of Stripes in Spin and Charge Dynamics of Underdoped La2−x Sr x CuO4

We investigate the electronic states of underdoped La _2–x Sr _x CuO ₄ (LSCO) by using a microscopic model, i.e., t-t-t-J model, containing charge stripes. The numerically exact diagonalization calculation is employed on small clusters. The physical properties observed in the angle-resolved photoemission and optical conductivity experiments are consistently explained in the model with vertical stripes, but not diagonal ones. These results demonstrate a crucial role of the vertical stripes in underdoped LSCO.     

Far-infrared laser oscillation due to cyclotron emission in p-type germanium

Far-infrared laser oscillation due to cyclotron emission in the light hole band of p-type germanium was observed under crossed electric and magnetic fields. The wavelength is inversely proportional to magnetic fields with a cyclotron mass ofm _c =0.048m _c . Numerical calculations based on Luttinger Hamiltonian show that mixing of wavefunctions between the light and heavy hole bands causes population inversion betweenn=0 andn=1 light-hole Landau levels. It is also shown that non-equidistant energy spacing of light-hole Landau levels is essential to yield net amplification.     

A theoretically reproduced phase diagram for vinylidene fluoride and trifluoroethylene copolymers

The phase diagram of ferroelectric copolymers of vinylidene fluoride and trifluoroethylene is reproduced theoretically using a simple model for ferroelectric polymers. The copolymerization ratio dependencies of the intramolecular interaction and the intermolecular interaction are induced to reproduce the phase diagram. These interactions have the following effects on the ferroelectric phase transition of the copolymers. The intermolecular interaction between vinylidene fluoride segments is dominant in the ferroelectric phase transition. The intramolecular interaction, discriminating between different chain conformations, gives the phase transition a variety of characters, including first and second order phase transitions. The copolymerization ratio dependence of the intermolecular interaction is also numerically estimated by summing the interaction energy between all atoms. Comparing these two results, we discuss the size of a segment carrying an elementary process of the phase transition.     

Direct projections from the entorhinal cortical layers to the dentate gyrus, hippocampus, and subicular complex in the cat

Projections from each layer of the entorhinal cortex (EC) of the cat were traced to the dentate gyrus (DG), Ammon's horn (CA), prosubiculum (ProSb), subiculum (Sb), presubiculum (PreSb) and parasubiculum (ParaSb); the anterograde or retrograde labeling method was used after stereotaxic injection of wheat germ agglutinin-horseradish peroxidase, cholera toxin B subunit, or Phaseolus vulgaris leucoagglutinin. On the side ipsilateral to the tracer-injection, layer II of the EC projected most abundantly to the outer half of the molecular layer (ML) of the DG, less abundantly to the almost entire thickness of the stratum lacunosum-moleculare (SLM) of CA2-3, moderately to the almost entire thickness of the SLM of CA1, and less to the outer part of the ML of the ProSb and Sb. Layer III projected abundantly to the almost entire thickness of the SLM of CA1 and outer part of the ML of the ProSb and Sb, and sparsely to the SLM of CA2-3. Layer IV projected sparsely to the pyramidal cell layer of the ProSb and Sb; Layer IV of the medial part (toward the ParaSb) of the EC projected further to the ML of the DG. Layer VI projected sparsely to the outer part of the ML of the DG, almost entire thickness of the SLM of CA1-3, and outer part of the ML of the ProSb and Sb. More temporal parts of the hippocampal region received the projections from progressively more medial and more rostral parts of layers II and III, and from progressively more rostral parts of layers IV and VI. The ML of the PreSb and ParaSb received projections from all layers of the medial part of the ipsilateral EC. The SLM of CA1 and ML of the ProSb, Sb and ParaSb received projections from layer II and/or III of the contralateral medial entorhinal area.     

Two distinct patterns of peritoneal involvement shown by in vitro and in vivo ovarian cancer dissemination models

We established an in vitro peritoneal dissemination model using six ovarian cancer cell lines and cultured mesothelial cells. Ovarian cancer cells were classified into two types, invasive or adhesive, on the basis of their interaction with the mesothelial cell monolayer. The ovarian cancer cell lines derived from mucinous cystadenocarcinoma, poorly differentiated adenocarcinoma and undifferentiated carcinoma, which belonged to the invasive type, began to invade beneath the mesothelial monolayer from several hours after seeding in vitro, expelling the mesothelial cells at the periphery and forming colonies directly on the dish surface. On the other hand, cancer cell lines of clear cell carcinoma, which belonged to the adhesive type, showed colony formation with adhesion on the mesothelial monolayer even 18 h after seeding. Invasive-type cell lines invaded into the mesothelial monolayer at various rates in vitro, and the degree of invasiveness showed good correlation with the degree of peritoneal dissemination in vivo after intraperitoneal injection of cancer cells into nude mice. Adhesive-type cells showed rather higher dissemination rates in vivo. Microscopic observation of in vivo peritoneal dissemination at one day after inoculation also revealed two patterns of peritoneal involvement similar to those in vitro. In the in vitro model, anti-integrin alpha 2- and beta 1-antibodies inhibited the infiltration of invasive-type cells into the mesothelial monolayer, but did not affect colony formation by adhesive-type cells on the monolayer, indicating that invasion by both cell types was mediated by different molecules. This in vitro model is thought to be useful for analysis of the molecular mechanisms of peritoneal dissemination.