Highly reversible capacity at the surface of a lithium-rich manganese oxide: a model study using an epitaxial film system.

Epitaxial films of Li2MnO3 were synthesized using pulsed laser deposition. A 12.6 nm film exhibited a high discharge capacity of over 300 mA h g(-1) following its fiftieth cycle and better stability than 29.8 and 47.8 nm films. The surfaces of such films are intrinsically active at the electrochemical interface.

Quantitative MAS NMR characterization of the LiMn(1/2)Ni(1/2)O(2) electrode/electrolyte interphase.

The conditions in which degradation processes at the positive electrode/electrolyte interface occur are still incompletely understood and traditional surface analytical techniques struggle to characterize and depict accurately interfacial films. In the present work, information on the growth and evolution of the interphases upon storage and cycling as well as their electrochemical consequences are gathered in the case of LiNi(1/2)Mn(1/2)O(2) with commonly used LiPF(6) (1M in EC/DMC) electrolyte. The use of (7)Li, (19)F and (31)P MAS NMR, made quantitative through the implementation of empirical calibration, is combined with transmission electron microscopy (TEM) and electron energy loss spectroscopy (EELS) to probe the elements involved in surface species and to unravel the inhomogenous architecture of the interphase. At room temperature, contact with the electrolyte leads to a covering of the oxide surface first by LiF and lithiated organic species are found on the outer part of the interphase. At 55°C, not only the interphase proceeds in further covering of the surface but also thickens resulting in an increase of 240% of lithiated species and the presence of -POF(2) fluorophosphates. The composition gradient within the interphase depth is also strongly affected by the temperature. In agreement with the electrochemical performance, quantitative NMR surface analyses show that the use of LiBOB-modified electrolyte results in a Li-enriched interphase, intrinsically less resistive than the standard LiPF(6)-based interphase, comprised of a mixture of resistive LiF with non lithiated species.

Neoclassical toroidal viscosity calculations in tokamaks using a δf Monte Carlo simulation and their verifications.

Neoclassical toroidal viscosities (NTVs) in tokamaks are investigated using a δf Monte Carlo simulation, and are successfully verified with a combined analytic theory over a wide range of collisionality. A Monte Carlo simulation has been required in the study of NTV since the complexities in guiding-center orbits of particles and their collisions cannot be fully investigated by any means of analytic theories alone. Results yielded the details of the complex NTV dependency on particle precessions and collisions, which were predicted roughly in a combined analytic theory. Both numerical and analytic methods can be utilized and extended based on these successful verifications.

Dose-dependent requirement of patched homologue 1 in mouse pancreatic beta cell mass.

AIMS/HYPOTHESIS: Ectopic activation of hedgehog (HH) signalling in pancreas induces various abnormal morphogenetic events in the pancreas. This study analysed the dose-dependent requirement of patched homologue 1 (PTCH1), a negative regulator of HH signalling on pancreatic development. METHODS: We used a recessive spontaneous mutant mouse denoted as mes which carries a mutated Ptch1 resulting in deletion of the most carboxy-terminal cytoplasmic domain of the PTCH1 protein. In this study, we analysed pancreatic morphology in Ptch1 ( +/+ ), Ptch1 ( +/mes ), Ptch1 (+/-), Ptch1 ( mes/me ) (s) and Ptch1 (-/mes ) mouse embryos, as well as the islet mass in adult Ptch1 (+/+), Ptch1 (+/mes ) and Ptch1 (+/-) mice. RESULTS: Until embryonic day (E) 12.5, no obvious abnormality of pancreas was observed in any of the Ptch1 mutants. The levels of PDX1 and glucagon were also not evidently different among the mice genotypes studied. Thereafter, morphological abnormalities appeared in the Ptch1 mutant mice. The beta, alpha and exocrine cell masses decreased at E18.5 in parallel with increased HH signalling, with beta cell mass showing the highest sensitivity to HH signalling with a significant decrease even in Ptch1 (+/mes ) mice. Adult Ptch1 (+/-) mice also showed a significant decrease in beta cell mass compared with wild-type mice. CONCLUSIONS/INTERPRETATION: Our findings indicate that the carboxy-terminal domain of Ptch1 is essential for pancreatic development. In addition, the loss of Ptch1 function decreases both the endocrine and exocrine cell mass in a dose-dependent manner, with beta cells particularly sensitive to changes in HH signalling.

Spin gap in Tl2Ru2O7 and the possible formation of Haldane chains in three-dimensional crystals.

Dimensionality is one of the most important parameters of physical phenomena. Only two things determine the universality class of a phase transition: the dimensionality of a given system and the symmetry of the order parameter. In most cases, the dimensionality of a substance is predetermined by its crystal structure. Examples in which the effective dimensionality is reduced are quite rare. Here we show that the three-dimensional cubic system of Tl(2)Ru(2)O(7) most probably evolves into a one-dimensional spin-one Haldane system with a spin gap below 120 K, accompanied by anomalies in the structure, resistivity and susceptibility. We argue that these anomalies are due to an orbital ordering of Ru 4d electrons, with a strong coupling among three degrees of freedom: orbital, spin and lattice. Our work provides a unique example of the spontaneous formation of Haldane system with an insight into the intriguing interplay of different degrees of freedom.

Structure, backbone dynamics and interactions with RNA of the C-terminal RNA-binding domain of a mouse neural RNA-binding protein, Musashi1.

Musashi1 is an RNA-binding protein abundantly expressed in the developing mouse central nervous system. Its restricted expression in neural precursor cells suggests that it is involved in the regulation of asymmetric cell division. Musashi1 contains two ribonucleoprotein (RNP)-type RNA-binding domains (RBDs), RBD1 and RBD2. Our previous studies showed that RBD1 alone binds to RNA, while the binding of RBD2 is not detected under the same conditions. Joining of RBD2 to RBD1, however, increases the affinity to greater than that of RBD1 alone, indicating that RBD2 contributes to RNA-binding. We have determined the three-dimensional solution structure of the C-terminal RBD (RBD2) of Musashi1 by NMR. It folds into a compact alpha beta structure comprising a four-stranded antiparallel beta-sheet packed against two alpha-helices, which is characteristic of RNP-type RBDs. Special structural features of RBD2 include a beta-bulge in beta2 and a shallow twist of the beta-sheet. The smaller 1H-15N nuclear Overhauser enhancement values for the residues of loop 3 between beta2 and beta3 suggest that this loop is flexible in the time-scale of nano- to picosecond order. The smaller 15N T2 values for the residues around the border between alpha2 and the following loop (loop 5) suggest this region undergoes conformational exchange in the milli- to microsecond time-scale. Chemical shift perturbation analysis indicated that RBD2 binds to an RNA oligomer obtained by in vitro selection under the conditions for NMR measurements, and thus the nature of the weak RNA-binding of RBD2 was successfully characterized by NMR, which is otherwise difficult to assess. Mainly the residues of the surface composed of the four-stranded beta-sheet, loops and C-terminal region are involved in the interaction. The appearance of side-chain NH proton resonances of arginine residues of loop 3 and imino proton resonances of RNA bases upon complex formation suggests the formation of intermolecular hydrogen bonds. The structural arrangement of the rings of the conserved aromatic residues of beta2 and beta3 is suitable for stacking interaction with RNA bases, known to be one of the major protein-RNA interactions, but a survey of the perturbation data suggested that the stacking interaction is not ideally achieved in the complex, which may be related to the weaker RNA-binding of RBD2.

mel-18 negatively regulates cell cycle progression upon B cell antigen receptor stimulation through a cascade leading to c-myc/cdc25.

mel-18 is a mammalian Polycomb group gene encoding a transcriptional repressor with tumor suppressive activity. Overexpression of mel-18 in mice results in cell cycle arrest of B cells upon B cell receptor stimulation with downregulation of c-myc. This phenotype is rescued in mel-18/c-myc double-transgenic mice, suggesting that c-myc locates downstream of mel-18. In mel-18 transgenic mice, the downregulation of cyclins D2 and E; CDK4, -6, and -7; and CDC25A causes the impairment in the activities of cyclin-dependent kinases, resulting in hypophosphorylation of the retinoblastoma protein. In contrast, the upregulation of c-Myc, CDC25, and CDC2/CDK2 kinase activities results in the augmentation of B cell proliferation in mel-18-deficient mice. We therefore propose that mel-18 negatively regulates the cell cycle through a c-myc/cdc25 cascade.

Mammalian Polycomb group genes are categorized as a new type of early response gene induced by B-cell receptor cross-linking.

Polycomb group (PcG) genes were initially described in Drosophila melanogaster as regulators of the homeobox gene. Four mammalian homologues, mel-18, bmi-1, M33 and rae-28, are analyzed in this study. They not only regulate mammalian homeotic genes by analogy with their Drosophila counterparts, but also have some influence on the growth and differentiation of B lymphocytes. Here we report that these four mammalian PcG genes are rapidly induced after antigen-receptor cross-linking in B cells. Thus we would like to propose that mammalian PcG genes can be categorized as a new type of immediate early gene.

Clinicopathologic features of local and metastatic recurrences in primary lung adenocarcinoma.

We attempted to construct the contour of recurrence in primary lung adenocarcinoma with clinicopathologic variables based on data of 131 patients with completely resected primary lung adenocarcinoma. In univariate analysis, tumor size (more or less 3 cm in diameter), p-T, p-N, pathological stage, differentiation, ly factor and v factor were chosen for prognostic predictors. In multivariate analysis, v factor and p-N were independent variables of local recurrence and metastatic recurrence, respectively. The examination of significant correlation among clinicopathologic variables in terms of 5-year survival rates of patients showed that tumor size, p-T, ly factor and v factor were profoundly related to local recurrence, whereas ly factor, differentiation and p-N were linked to distant metastasis. We therefore examined an additive effect of tumor size, differentiation and vascular invasion on recurrence. The results demonstrated that neither local nor metastatic recurrences were found in patients with well differentiated adenocarcinoma less than 3 cm in diameter if vascular invasion was negative. We conclude that vascular (ly factor and v factor) is central to lung adenocarcinoma recurrence. The vascular invasion is a powerful predictor of recurrence in less than 3 cm diameter, well differentiated adenocarcinoma of the lung.

[Recurrent thymic carcinoid tumor with multiple endocrine neoplasia syndrome--a case report].

A 55-year-old male with multiple endocrine neoplasia syndrome accompanied by hyperparathyroidism and hypergastrinemia was admitted because of local recurrence of thymic carcinoid tumor and a parathyroid adenoma. The recurrent thymic carcinoid tumor replaced anterior mediastinum, invaded brachiocephalic vein and superior vena cava, a disseminated nodule was found at pericardium. After induction chemotherapy using carboplatin and etoposide the operation was performed. The parathyroid tumor and recurrent thymic carcinoid tumor were removed completely together with brachiocephalic vein, superior vena cava, pericardium and anterior chest wall. Superior vena cava was replaced with synthetic graft and chest wall was reconstructed. The patient is alive and well 22 months after surgery without recurrence. Immunohistochemistry of removed specimens revealed parathormone and gastrin secreted from the parathyroid adenoma but not from the carcinoid tumor. Careful survey of systemic endocrine organs is necessary in case of thymic carcinoid tumor. Aggressive surgery in locally recurrent thymic carcinoid without distant metastasis must be considered.

On the linearization of eruption series of the permanent teeth.

In order to confirm the linearization of permanent eruption, Masuyama's linearization method was applied to the data of Kitamura's study. At first, we considered the eruption age t alpha i of permanent teeth T alpha, where alpha corresponds a tooth of every description, and examined the linear regression of Y alpha i = log10 t alpha i on m(y) alpha (the mean of Y alpha i with respect to i), but the result was not good. For the correlation coefficient r between two variables in linear regression, the percentage of subjects with r > or = 0.970 was only 10.3% in males and 28.8% in females in Kitamura's study. Next we took notice of the eruption age u beta i of each tooth, which is the beta-th in order of eruption. The fitness of the linear regression of Z beta i = log10 u beta i on mz beta (the mean of Z beta i) was very good. The percentage of subjects with r > or = 0.970 increased to 80.0% in males and 86.0% in females. Then we used m(y) (beta) (rearranged m(y) alpha in order of increasing size) instead of mz beta as an independent variable in the linear regression. The degree of the linearization was slightly inferior to that using mz beta. In every linearization, a quasi-fixed point with coordinates (C, C) existed on the linearized dentition plot, where the value of C was almost equal in each way, i.e., C = 10.23 (years) for males and C = 8.91 (years) for females in Kitamura's data. This linearized dentition plot will be useful in detecting certain growth disturbances. The existence of a quasi-fixed point may be useful in forecasting the age of the eruption of subsequent teeth, once the first eruption is observed.

Development of Valpha4+ NK T cells in the early stages of embryogenesis.

The majority of T lymphocytes start to develop at around day 15 of gestation (d15)-d17 in the thymus and comprise the peripheral repertoire characterized by the expression of polymorphic T-cell antigen receptors (TCRs). Contrary to these conventional T cells, a subset of T cells, called natural killer (NK) T cells (most of them expressing an invariant TCR encoded by the Valpha14Jalpha281 gene with a 1-nt N-region), preferentially differentiates extrathymically and dominates the peripheral T-cell population at a high frequency (5% in splenic T cells and 40% in bone marrow T cells). Here, we investigated the development of NK T cells and found that the invariant Valpha14+ TCR transcripts and the circular DNA created by Valpha14 and Jalpha281 gene rearrangements can be detected in the embryo body at d9.5 of gestation and in the yolk sac and the fetal liver at d11.5-d13.5 of gestation, but not in the thymus, whereas T cells with Valpha1+ TCR expression, a major population in the thymus, were not observed at these early stages of gestation. Fluorescence-activated cell sorter analysis also demonstrated that there exist CD3+ alpha beta+ T cells, almost all of which are Valpha14/Vbeta8+ NK+ T cells, during early embryogenesis. To our knowledge, this demonstrates for the first time that a T lymphocyte subset develops in extrathymic tissues during the early stages of embryogenesis.

Cloning and characterization of two transcripts generated from the mel-13 gene positioned adjacent to the mammalian Polycomb group-related gene mel-18.

We previously isolated the mel-18 gene, a mammalian Polycomb group (PcG)-related gene with homology to bmi-1 oncogene. We show in this paper the existence of a new gene, mel-13, which overlapped with the mel-18 anti-oncogene. We discuss the relationships between mel-13 and the mel-18, bup, and Su(z)2 genes.

Dental health indicator based on a questionnaire.

Dentistry has lacked an effective indicator of the impact of dental problems on a person's daily life. Subjective factors in dental health need to be included in order to improve current indicators. The purpose of this research was to develop a new type of indicator recorded from a questionnaire which takes account of subjective factors in dental health. The indicator we constructed has the following advantages. 1. Calculation process is simple in practice. 2. The indicator values range from 0 to 100, with values closer to 100 indicating a more favorable condition for the individual. 3. The distribution of indicator values is similar to the normal distribution. 4. The score of each item is reflected on the indicator, suggesting the individual's characteristics in terms of dental health. 5. Although it is principally an indicator for individuals, it can also be applied to groups. This study will also provide a model for the preparation of a dental health indicator.

Predominant expression of invariant V alpha 14+ TCR alpha chain in NK1.1+ T cell populations.

A novel T cell subset characterized by cell surface NK1.1+ TCR alpha beta+ expression was investigated for its TCR alpha usage, particularly that of invariant V alpha 14 TCR, which was found to be preferentially used in peripheral CD4-CD8- T cells developed at extrathymic sites. We found that NK+ alpha beta T cell subsets account for 0.4% in thymocytes, 5% in the splenic T cells and 40.5% in the bone marrow T cells. Among these NK+ alpha beta T cells, two distinct subsets were detected; cell surface TCR V alpha 14+ and V alpha 14- subpopulations. Almost all of NK+ alpha beta thymocytes express V alpha 14 mRNA; however, only < 20% were positive, while > 80% were negative or undetectable for V alpha 14 TCR expression on the cell surface in the thymus. Similarly, approximately 50% of NK+ alpha beta T cells in spleen and bone marrow are V alpha 14+ as revealed by FACS. TCR repertoire analysis by nucleotide sequences on inverse PCR products demonstrated that most NK+ alpha beta T cells express an invariant TCR encoded by the V alpha 14J alpha 281 gene with a 1 base N-region in all tissues. Thus, invariant V alpha 14 TCR is uniquely expressed on NK T cells, and can be a marker to distinguish NK, NK T and T cells.

Extrathymic development of V alpha 14-positive T cells.

It is known that rearrangement of the T cell antigen receptor (TCR) gene occurs in the thymus during T cell development and consequently results both in the deletion of DNA between the variable (V) and diversity/joining segments and in the formation of a circular DNA with recombination signal sequences. Here, we provide evidence that V alpha 14+ TCR gene rearrangements take place in extrathymic sites, such as bone marrow, liver, and intestine, but not in spleen, because we were able to detect frequent productive and nonproductive V alpha 14+ coding and signal sequences as a result of TCR rearrangements in extrathymic sites. Similar findings were also detected in athymic mice. Quantitative analysis shows that the relative amounts of V alpha 14 gene-mediated signal sequences in extrathymic tissues are higher than those in thymus. On the contrary, TCR rearrangements of V alpha 1.1 T cells, which are known to develop in the thymus, were mainly detected in the thymus, Peyer's patch, and spleen, but not in other extrathymic tissues, showing patterns distinct from V alpha 14 TCR rearrangements. These findings are evidence of extrathymic development of V alpha 14+ T cells. Differential characteristic TCR rearrangement patterns also indicate that distinct TCR repertoires are generated in different lymphoid tissues.

[A study of the right ventricular load at the unilateral pulmonary artery occlusion test after pneumonectomy].

After pneumonectomy, it is recognized that the absolute reduction of the pulmonary vascular bed makes the right ventricular afterload increase and can cause right heart failure in patients with low cardiopulmonary reserve. Therefore, we investigated how the right ventricular load was predicted by UPAO test, comparing hemodynamics at the time of the test with those after pneumonectomy in patients with lung cancer. At the test, the absolute reduction of the pulmonary vascular bed made the right ventricular afterload increase but the right ventricular pump function was maintained at the preoperative level by the increase of the right ventricular work load, namely, by the contraction of the right ventricle. After pneumonectomy, the absolute reduction of the vascular bed did not always make the afterload increase and in spite of the decreased preload the pump function was maintained at the preoperative level by increased heart rate. Additionally, the increase of the right ventricular work load improved during early postoperative days. It was concluded that UPAO test was apt to overestimate the right ventricular load of the postoperative day because it was done under the condition of the different compensatory function from the postoperative hypovolemic change.