Effect of Lubrication and Forging Load on Surface Roughness, Residual Stress, and Deformation of Cold Forging Tools

Cold forging is a metal forming that which uses localized compressive force at room temperature. During the cold forging process, the tool is subjected to extremely high loads and abrasive wear. Lubrication plays an important role in cold forging to improve product quality and tool life by preventing direct metallic contact. Surface roughness and residual stress also greatly affects the service life of a tool. In this study, variations in surface roughness, residual stress, and specimen deformation with the number of cold forging cycles were investigated under different forging conditions. Specimens that were made of heat-treated SKH51 (59-61 HRC), a high-speed tool steel with a polished working surface, were used. The specimens were subjected to an upsetting process. Compressive residual stress, surface roughness, and specimen deformation showed a positive relationship with the number of forging cycles up to a certain limit and became almost constant in most of the forging conditions. A larger change in residual stress and surface roughness was observed at the center of the specimens in all the forging conditions. The effect of the magnitude of the forging load on the above discussed parameters is large when compared to the effect of the lubrication conditions

Low-lying magnon excitations in integer-spin ladders and tubes

We consider low-energy excitation structures of N-leg integer-spin ladder and tube systems with an antiferromagnetic (AF) intrachain coupling and a uniform external field. The tube means the ladder with the periodic boundary condition along the interchain (rung) direction. Odd-leg AF-rung tubes have the frustration. In order to analyze all systems including frustrated tubes, we apply a field-theoretical method based on the nonlinear sigma model. We mainly focus on the systems without any external fields. In this case, it is shown that the lowest bands of frustrated tubes always consist of six-fold degenerate magnon excitations, while those of all other systems are triply degenerate. This result implies that the ground states of frustrated tubes (all non-frustrated systems) become a two (one)-component Tomonaga-Luttinger liquid, when a sufficiently strong uniform field is applied.Comment: 4 pages, 5 figures, published version (Proceedings of ISSP-9). See also cond-mat/050604

Alpha lipoic acid selectively inhibits proliferation and adhesion to fibronectin of v-H-ras-transformed 3Y1 cells

Here, we focused on the effects of racemic α-lipoic acid on proliferation and adhesion properties of 3Y1 rat fibroblasts and the v-H-ras-transformed derivative, HR-3Y1-2 cells. Racemic α-lipoic acid inhibited proliferation of HR-3Y1-2 but not 3Y1 cells at 0.3 and 1.0 mM. R-(+)-α-lipoic acid also inhibited proliferation of HR-3Y1-2 cells equivalent to that of racemic α-lipoic acid. In addition, racemic α-lipoic acid decreased intracellular reactive oxygen species levels in HR-3Y1 cells but not 3Y1 cells. Next, we evaluated the effects of racemic α-lipoic acid on cell adhesion to fibronectin. The results indicated that racemic α-lipoic acid decreased adhesive ability of HR-3Y1-2 cells to fibronectin-coated plates. As blocking antibody experiment revealed that β1-integrin plays a key role in cell adhesion in this experimental system, the effects of racemic α-lipoic acid on the expression of β1-integrin were examined. The results indicated that racemic α-lipoic acid selectively downregulated the expression of cell surface β1-integrin expression in HR-3Y1-2 cells. Intriguingly, exogenous hydrogen peroxide upregulated cell surface β1-integrin expression in 3Y1 cells. Taken together, these data suggest that reduction of intracellular reactive oxygen species levels by α-lipoic acid could be an effective means of ameliorating abnormal growth and adhesive properties in v-H-ras transformed cells

D0-branes in an H-field Background and Noncommutative Geometry

It is known that if we compactify D0-branes on a torus with constant B-field, the resulting theory becomes SYM theory on a noncommutative dual torus. We discuss the extension to the case of a H-field background. In the case of constant H-field on a three-torus, we derive the constraints to realize this compactification by considering the correspondence to string theory. We carry out this work as a first step to examine the possibility to describe transverse M5-branes in Matrix theory.Comment: 15 pages, LaTeX; some comments added, typos corrected, to appear in Nucl. Phys.

In Silico Study of Rett Syndrome Treatment-Related Genes, MECP2, CDKL5, and FOXG1, by Evolutionary Classification and Disordered Region Assessment

Rett syndrome (RTT), a neurodevelopmental disorder, is mainly caused by mutations in methyl CpG-binding protein 2 (MECP2), which has multiple functions such as binding to methylated DNA or interacting with a transcriptional co-repressor complex. It has been established that alterations in cyclin-dependent kinase-like 5 (CDKL5) or forkhead box protein G1 (FOXG1) correspond to distinct neurodevelopmental disorders, given that a series of studies have indicated that RTT is also caused by alterations in either one of these genes. We investigated the evolution and molecular features of MeCP2, CDKL5, and FOXG1 and their binding partners using phylogenetic profiling to gain a better understanding of their similarities. We also predicted the structural order–disorder propensity and assessed the evolutionary rates per site of MeCP2, CDKL5, and FOXG1 to investigate the relationships between disordered structure and other related properties with RTT. Here, we provide insight to the structural characteristics, evolution and interaction landscapes of those three proteins. We also uncovered the disordered structure properties and evolution of those proteins which may provide valuable information for the development of therapeutic strategies of RTT

Constraining Light Gravitino Mass from Cosmic Microwave Background

We investigate the possibilities of constraining the light gravitino mass m_{3/2} from future cosmic microwave background (CMB) surveys. A model with light gravitino with the mass m_{3/2}<O(10) eV is of great interest since it is free from the cosmological gravitino problem and, in addition, can be compatible with many baryogenesis/leptogenesis scenarios such as the thermal leptogenesis. We show that the lensing of CMB anisotropies can be a good probe for m_{3/2} and obtain an expected constraint on m_{3/2} from precise measurements of lensing potential in the future CMB surveys, such as the PolarBeaR and CMBpol experiments. If the gravitino mass is m_{3/2}=1 eV, we will obtain the constraint for the gravitino mass as m_{3/2} < 3.2 eV (95% C.L.) for the case with Planck+PolarBeaR combined and m_{3/2}=1.04^{+0.22}_{-0.26} eV (68% C.L.) for CMBpol. The issue of Bayesian model selection is also discussed.Comment: 22 pages, 6 figures, 7 tables, references are added, accepted for publication in JCA

Findings from recent studies by the Japan Aerospace Exploration Agency examining musculoskeletal atrophy in space and on Earth

The musculoskeletal system provides the body with correct posture, support, stability, and mobility. It is composed of the bones, muscles, cartilage, tendons, ligaments, joints, and other connective tissues. Without effective countermeasures, prolonged spaceflight under microgravity results in marked muscle and bone atrophy. The molecular and physiological mechanisms of this atrophy under unloaded conditions are gradually being revealed through spaceflight experiments conducted by the Japan Aerospace Exploration Agency using a variety of model organisms, including both aquatic and terrestrial animals, and terrestrial experiments conducted under the Living in Space project of the Japan Ministry of Education, Culture, Sports, Science, and Technology. Increasing our knowledge in this field will lead not only to an understanding of how to prevent muscle and bone atrophy in humans undergoing long-term space voyages but also to an understanding of countermeasures against age-related locomotive syndrome in the elderly

Clinical characteristics and course of sporadic non-ampullary duodenal adenomas A multicenter retrospective study

Sporadic non-ampullary duodenal adenoma (SNADA) is a rare disease, and therefore, its clinical characteristics have not been comprehensively investigated. Furthermore, owing to the high complication rates and severity of endoscopic resection, treatment strategies vary among facilities. In the present study, we aimed to clarify the clinical characteristics and course of SNADA. We extracted clinical and histological records of SNADA cases diagnosed in 11 hospitals between September 1999 and August 2014. The patients were divided into "no-resection" and "resection" groups based on the initial treatment approach. We investigated the long-term outcome of the "no-resection" group and treatment results of the "resection" group, with particular interest in endoscopic resection. Overall, 299 patients were diagnosed with SNADA. The median age at diagnosis was 67 years (range, 31-88 years), with approximately twice as many men as women. The median tumor size was 8.0 mm (2-60 mm). In total, 161 patients were initially selected for no-resection and 138 underwent resection. Age >70 years and the presence of either severe illness or poor performance status were significantly related to opting for no-resection. In the no-resection group, 101 patients underwent endoscopic follow-up for at least 1 year. During the observational period (2.5 +/- 2.2 years), 27 lesions (27%) disappeared following cold forceps biopsy, and 13 lesions (14%) presented lateral growth. Four lesions (4%) changed to mucosal carcinoma, 3 were treated endoscopically, and 1 was surgically resected. Nineteen patients died; however, no one died of duodenal carcinoma. In the endoscopic resection group, en bloc resection was achieved in 78% of patients. However, the complication rate for perforation was 7%, and endoscopic submucosal dissection was associated with a 36% perforation rate. With the low incidence of cancer development and no disease specific death, the strategy of initially not performing resection could be considered especially for the older adults, poor-prognosis patients, or small lesions

Relationships between thermic effect of food, insulin resistance and autonomic nervous activity

Background: The thermic effect of food (TEF) is higher in lean than in obese human subjects. Objective: Relationships between TEF and insulin resistance during meals, from the point of view of autonomic nervous activity, were evaluated. Methods : Autonomic nervous activity was evaluated in 20 young adults using the spectral analysis of heart rate variability from one hour before to two hours after a meal. Heart rate data were analyzed based on low frequency components (LF power, 0.04 - 0.15Hz),high frequency components (HF power, 0.15-0.40 Hz), and LF/HF ratios. Energy expenditure and the TEF were measured 30 min after a meal. Homeostasis model of insulin resistance index (HOMA-IR) was also measured. Results : The LF/HF ratio was significantly increased 30minafter a meal (p<0.05).No correlation between LF power and HF power with TEF was found, but the LF/HF ratio was significantly and positively correlated with TEF(r＝＋0.56,p<0.05). Moreover, a significant negative correlation was found between the HOMA-IR and TEF (r＝－0.601, p<0.05). Conclusions : The findings suggest that a reduction in insulin sensitivity induces a poor response of sympathetic nervous activity in the postprandial phase and a reduction in postprandial energy expenditure

Factors Predicting a Favorable Disease Course Without Anti-TNF Therapy in Crohn’s Disease Patients

Determining factors that predict a favorable disease course without anti-tumor necrosis factor (TNF) agents would help establish a more cost-effective strategy for Crohn’s disease (CD). A retrospective chart review was performed for CD patients with disease durations > 10 years who had not received anti-TNF agents as first-line therapy. Patients were divided into 2 groups: those who received neither anti-TNF agents nor bowel resection (G1), and those who had received an anti-TNF agent and/or bowel resection (G2). The patient backgrounds, therapies and clinical courses were compared between the groups. A total of 62 CD patients met the inclusion criteria (males: 71%; median duration of follow-up: 19 years). Six patients were included in G1; they were significantly less likely to have upper gastrointestinal lesions than G2 (p=0.007). A multivariate analysis revealed that the significant factors for avoidance of bowel resection without anti-TNF treatment were non-stricturing and non-penetrating behaviors, and absence of upper gastrointestinal lesions at the diagnosis (hazard ratios 0.41 and 0.52; p=0.004 and 0.04, respectively). In consideration of the long treatment course of CD, patients with non-stricturing and non-penetrating behaviors and no upper gastrointestinal lesions should not be treated with anti-TNF agents as first-line therapy