Ferromagnetism induced in anisotropic stacked kagome-lattice antiferromagnet Cs2_2Cu3_3CeF12_{12}

The magnetic properties of Cs$_2$Cu$_3$CeF$_{12}$ were investigated through magnetization and specific heat measurements. Cs$_2$Cu$_3$CeF$_{12}$ is composed of a buckled kagome lattice of Cu$^{2+}$, which is stacked along the b axis. The exchange network in the buckled kagome lattice is strongly anisotropic. Consequently, Cs$_2$Cu$_3$CeF$_{12}$ can be divided into two subsystems: alternating Heisenberg chains with strong antiferromagnetic exchange interactions and dangling spins. The dangling spins couple with one another via effective exchange interactions, which are mediated by chain spins. The dangling spins are further divided into two subsystems, DS1 and DS2. The dangling spins in DS1 undergo three-dimensional ferromagnetic ordering at 3.14 K, while those in DS2 remain paramagnetic down to 0.35 K. The effective interaction between the DS1 spins is approximately expressed by the ferromagnetic $XXZ$ model with the $z$ direction parallel to the crystallographic c axis. A magnetic phase diagram for $H {\parallel} c$ was obtained and was analyzed within the framework of the molecular field approximation. With increasing magnetic field, the dangling spins are polarized and the magnetization curve exhibits a wide plateau at one-third of the saturation magnetization.Comment: 10 pages, 12 figure

Effective reduction of magnetisation losses in copper-plated multifilament coated conductors using spiral geometry

We wound copper-plated multifilament coated conductors spirally on a round core to decouple filaments electromagnetically under ac transverse magnetic fields and measured their magnetisation losses. Although the coated conductors were plated with copper, which connects all filaments electrically and allows current sharing among them, the spiral geometry decoupled filaments similar to the twist geometry, and the magnetisation loss was reduced effectively by the multifilament structure. The measured magnetisation loss of a 4 mm wide, 10-filament coated conductor with a 20 μm thick copper wound spirally on a 3 mm core was only 7% of that of the same 10-filament coated conductor with a straight shape under an ac transverse magnetic field with an amplitude and frequency of 100 mT and 65.44 Hz, respectively. We separated the measured magnetisation losses into hysteresis and coupling losses and discussed the influence of filament width, copper thickness, and core diameter on both losses. We compared the hysteresis losses with the analytical values given by Brandt and Indenbom and compared the coupling losses with the values calculated using a general expression of coupling loss with the coupling time constants and geometry factors

Human Papillomavirus Genome in Oral Carcinoma and Their Metastatic Cervical Lymph Node Tissues.

Twenty cases of oral squamous cell carcinoma (SCC) with cervical lymph node metastasis were investigated. Both primary lesions and metastatic lymph nodes were analyzed for the involvement of human papillomavirus (HPV) DNAs utilizing the polymerase chain reaction (PCR) method and dot blot hybridization. HPV DNAs were detected in five cases. Four primary lesions contained HPV-16 DNA, and one contained both HPV-16 and HPV-18 DNAs out of 20 cases examined. No HPV DNAs were detected in metastatic lymph node tissues in cases where HPV DNAs could not be detected in primary cancer tissues. The same types of HPV DNAs as those found in primary lesions were detected in metastatic lymph nodes including those with HPV-16 and HPV-18

Detection of Human Papillomavirus (HPV) DNA Sequences in Normal Oral Scrapes Using the Nested PCR.

We investigated the prevalence rate of HPV DNAs in normal mucosa in the oral region. The nested PCR method was utilized to detect target DNA sequences using HPV E6/E7 consensus primer pairs. Of 56 patients examined, HPV 6 and HPV 16 DNA sequences were detected in a 46-year-old male and a 35-year-old female, respectively. These results suggest that HPVs are uncom-mon in normal oral epithelium, and that we should carry out careful follow-up in HPV DNA-positive cases

Composite structural motifs of binding sites for delineating biological functions of proteins

Most biological processes are described as a series of interactions between proteins and other molecules, and interactions are in turn described in terms of atomic structures. To annotate protein functions as sets of interaction states at atomic resolution, and thereby to better understand the relation between protein interactions and biological functions, we conducted exhaustive all-against-all atomic structure comparisons of all known binding sites for ligands including small molecules, proteins and nucleic acids, and identified recurring elementary motifs. By integrating the elementary motifs associated with each subunit, we defined composite motifs which represent context-dependent combinations of elementary motifs. It is demonstrated that function similarity can be better inferred from composite motif similarity compared to the similarity of protein sequences or of individual binding sites. By integrating the composite motifs associated with each protein function, we define meta-composite motifs each of which is regarded as a time-independent diagrammatic representation of a biological process. It is shown that meta-composite motifs provide richer annotations of biological processes than sequence clusters. The present results serve as a basis for bridging atomic structures to higher-order biological phenomena by classification and integration of binding site structures.Comment: 34 pages, 7 figure

Changes in Cerebral Hemodynamics during Complex Motor Learning by Character Entry into Touch-Screen Terminals

Introduction Studies of cerebral hemodynamics during motor learning have mostly focused on neurorehabilitation interventions and their effectiveness. However, only a few imaging studies of motor learning and the underlying complex cognitive processes have been performed. Methods We measured cerebral hemodynamics using near-infrared spectroscopy (NIRS) in relation to acquisition patterns of motor skills in healthy subjects using character entry into a touchscreen terminal. Twenty healthy, right-handed subjects who had no previous experience with character entry using a touch-screen terminal participated in this study. They were asked to enter the characters of a randomly formed Japanese syllabary into the touchscreen terminal. All subjects performed the task with their right thumb for 15 s alternating with 25 s of rest for 30 repetitions. Performance was calculated by subtracting the number of incorrect answers from the number of correct answers, and gains in motor skills were evaluated according to the changes in performance across cycles. Behavioral and oxygenated hemoglobin concentration changes across task cycles were analyzed using Spearman\u27s rank correlations. Results Performance correlated positively with task cycle, thus confirming motor learning. Hemodynamic activation over the left sensorimotor cortex (SMC) showed a positive correlation with task cycle, whereas activations over the right prefrontal cortex (PFC) and supplementary motor area (SMA) showed negative correlations. Conclusions We suggest that increases in finger momentum with motor learning are reflected in the activity of the left SMC. We further speculate that the right PFC and SMA were activated during the early phases of motor learning, and that this activity was attenuated with learning progress

ELECTRON MICROSCOPIC STUDY OF PERIOSTEAL HYPEROSTOSIS IN RATS WITH LATHYRISM INDUCED BY AMINOACETONITRILE

In various mesenchymal tissue alterations in lathyrism, as the lesions of cartilage and connective tissue and dissecting aneurysm of the aorta, a defect in formation of collagen fibers and mucopolysaccharide has been considered as an essential basic change. The present electron microscopic study was made on the ultrastructures of the bone matrix forming cells and the newly formed bone matrices in the aminoacetonitrile induced lathyrism, in order to see if the defect mentioned above is also found in the periosteal hyperostosis. The present investigation revealed following points: (1) The basic changes in the lathyric periosteal hyperostosis consist of a failure in development of the cytoplasmic organellae of the bone matrix forming cells, and a defect in formation of the collagen fibers as well as the ground substance of the newly formed bone matrix, resulting in characteristic mineralization disturbance in mottled pattern. (2) Of these basic changes the defect in formation of the collagen fibers as well as the ground substance, probably mucopolysaccharide, seems to be the same as those in the other mesenchymal tissue. (3) The failure in development of the cytoplasmic organellae, especially the granular endoplasmic reticulum of the bone matrix forming cells may be related to the defect in formation of the collagen fibers and the ground substance. (4) The defect in formation of the bone matrix may be responsible for the characteristic disturbance of mineralization in the newly formed bone matrix