Development of a torsion balance for adhesion measurements

A new torsion balance for study of adhesion in ceramics is discussed. A torsion wire and a linear variable differential transformer are used to monitor load and to measure pull-off force (adhesion force). The investigation suggests that this torsion balance is valuable in studying the interfacial properties of ceramics in controlled environments such as in ultrahigh vacuum. The pull-off forces measured in dry, moist, and saturated nitrogen atmosphere demonstrate that the adhesion of silicon nitride contacts remains low at humidities below 80 percent but rises rapidly above that. The adhesion at saturation is 10 times or more greater than that below 80 percent relative humidity. The adhesion in a saturated atmosphere arises primarily from the surface tension effects of a thin film of water adsorbed on the surface. The surface tension of the water film was 58 x 10 to the minus 5 to 65 x 10 to the minus 5 power. The accepted value for water is 72.7 x 10 to the minus 5 power N/cm. Adhesion characteristics of silicon nitride in contact with metals, like the friction characteristics of silicon carbide to metal contacts, can be related to the relative chemical activity of metals in ultrahigh vacuum. The more active the metal, the higher the adhesion

Visualization of the non-steady state oblique detonation wave phenomena around hypersonic spherical projectile

We studied experimentally the shock waves and combustion waves generated by a hypersonic spherical projectile in an explosive mixture. An acetylene/oxygen mixture diluted with argon (2C2H2 + 5O2 + 7Ar) was used with various initial pressures (detonation cell sizes) to observe optically with a shadowgraph imaging system a shock-induced combustion (SIC), a stable oblique detonation wave (ODW), and a wave called a Straw Hat type consisting of a strong SIC and ODW. The criticality of stabilizing an ODW around a projectile is expressed by the ratio of the projectile diameter, d, to the cell size, λ, as d/λ = 3.63–4.84. Although the Straw Hat type wave in the vicinity of criticality is an unstable phenomena, it has been mainly observed by a single frame picture to date, so that it is difficult to discuss the time history of its wave structure. In this study, it was remarkable to directly carry out continuous optical observations using a high speed video camera which can continuously film 100 pictures with a 1 μs frame speed so as to allow an investigation of the sustaining mechanism of the unstable wave structure. Our results allowed the identification of an increase in unsteadiness in the relative distance between the projectile fronts and the transition points to an ODW as the time increased. They also showed local explosions in the SIC region near transition point transformed the ODW front upstream

Integral Effects of Systemic Nitric Oxide Synthase Inhibition on Carotid Arterial Compliance

Decreased arterial compliance (increased arterial stiffness) is associated with cardiovascular events. Nitric oxide regulates vascular tone, which can influence arterial compliance. We previously investigated the effects of systemic nitric oxide synthase (NOS) inhibition on arterial compliance under the systemic α-adrenergic receptor blocking. In the present study, we investigated the effect of systemic NOS inhibition alone on central arterial compliance (via carotid arterial ultrasound imaging and applanation tonometry). Eighteen apparently healthy young adults (26±1 years) underwent intravenous infusions of NG-monomethyl-L-arginine (L-NMMA) or placebo (saline) on separate days. In the placebo control condition, no significant changes were observed in mean arterial pressure, cross-sectional compliance, and β-stiffness index. Mean arterial pressure increased significantly (84±2 vs. 96±3 mmHg) after the administration of L-NMMA, whereas there were no significant changes in cross-sectional compliance (0.11±0.01 vs. 0.12±0.01 mm2/mmHg), β-stiffness index (6.44±0.37 vs. 5.51±0.41 unit), or isobaric arterial compliance. Theses results in young healthy adults are not consistent with the idea that carotid arterial compliance is modulated by nitric oxide. Grant Support: This work was supported by Grants-in-Aid for Scientific Research from the Ministry of Education, Culture, Sports, Science and Technology of Japan (18300215, 18650186), JSPS Postdoctoral Fellowships for Research Abroad, and NIH grant AG20966

Plasma Pentraxin 3 Concentration Increases in Endurance-Trained Men

Introduction: Pentraxin 3 (PTX3), which is mainly produced by endothelial cells, macrophages, and smooth muscle cells in the atherosclerotic region, has a cardioprotective effect. Endurance exercise training has also been known to offer cardioprotection. However, the effect of regular endurance exercise on PTX3 is unknown. This study aimed to investigate whether plasma PTX3 concentrations increase in endurance-trained men. Ten young endurance-trained men and 12 age- and gender-matched sedentary controls participated in this study.Methods: We measured plasma PTX3 concentrations of the participants in each group. We also determined systemic arterial compliance (SAC) by using simultaneous M-mode ultrasound and arterial applanation tonometry of the common carotid artery and used HDL cholesterol (HDLC) as an index of cardioprotective effect.Results: Maximal oxygen uptake was significantly higher in the endurance-trained men than that in the sedentary controls. SAC and HDLC were significantly higher in the endurance-trained men than that in the sedentary controls (SAC = 1.74 ± 0.11 vs 1.41 ± 0.09 mL·mm Hg−1, P < 0.05; HDLC = 70 ± 5 vs 57 ± 4 mg·dL−1, P < 0.05). Plasma PTX3 concentrations were markedly higher in the endurance-trained men than that in the sedentary controls (0.93 ± 0.11 vs 0.68 ± 0.06 ng·mL−1, P < 0.05). Relationships between plasma PTX3 concentrations and SAC and HDLC were linear.Conclusions: This is the first study revealing that endurance-trained individuals had higher levels of circulating PTX3 than sedentary controls. PTX3 may play a partial role in endurance exercise training-induced cardioprotection

Left Hemihepatectomy for Hepatocellular Carcinoma Following Esophagectomy with Retrosternal Gastric Tube Reconstruction for Esophageal Cancer

Approximately 4% of patients with esophageal cancer develop a second primary malignancy in the upper gastrointestinal trunk. However, hepatectomy following esophagectomy for esophageal cancer has rarely been reported. We report the case of a 70-year-old man who underwent an esophagectomy for esophageal cancer with retrosternal gastric tube reconstruction. Nine years later, he developed hepatocellular carcinoma with tumor thrombus involving the left portal vein, and was successfully treated with left hemihepatectomy. Special attention should be paid to avoiding incidental injury of the gastric tube as well as the right gastroepiploic artery during the hepatectomy

Habitual aerobic exercise increases plasma pentraxin 3 levels in middle-aged and elderly women

Chronic inflammation that occurs with aging is one of the risk factors for cardiovascular disease. Regular exercise may prevent cardiovascular morbidity by decreasing chronic systematic inflammation. Additionally, excess inflammation can be reduced by the anti-inflammatory protein pentraxin 3 (PTX3). Thus, both habitual exercise and PTX3 have an anti-inflammatory effect. However, it is unclear whether regular exercise leads to increased plasma PTX3 concentration. In the present study, we investigated the effects of regular aerobic exercise on plasma PTX3 concentration in middle-aged and elderly women. Twenty-two postmenopausal women (60 ± 6 years) were randomly divided evenly into 2 groups (i.e., exercise intervention and control). Subjects in the exercise group completed 2 months of regular aerobic exercise training (walking and cycling, 30-45 min, 3-5 days·week(-1)). Before and after the intervention, we evaluated plasma PTX3 concentration, peak oxygen uptake, blood chemistry, and arterial distensibility (carotid arterial compliance and β-stiffness) in all participants. There were no significant differences in baseline parameters between the 2 groups. Plasma PTX3 concentration was significantly increased in the exercise group after the intervention (p < 0.05). High-density lipoprotein cholesterol, peak oxygen uptake, and arterial compliance were also significantly increased (p < 0.05), while β-stiffness was markedly decreased (p < 0.01) after the intervention. On the other hand, there was no change in the parameters tested in the control group. This study demonstrates that regular aerobic exercise increases plasma PTX3 concentration with improvement of high-density lipoprotein cholesterol, peak oxygen uptake, and arterial distensibility in postmenopausal women

Direct observation of the washboard noise of a driven vortex lattice in a high-temperature superconductor, Bi2Sr2CaCu2Oy

We studied the conduction noise spectrum in the vortex state of a high-temperature superconductor, Bi2Sr2CaCu2Oy, subject to a uniform driving force. Two characteristic features, a broadband noise (BBN) and a narrow-band noise (NBN), were observed in the vortex-solid phase. The origin of the large BBN was determined to be plastic motion of the vortices, whereas the NBN was found to originate from the washboard modulation of the translational velocity of the driven vortices. We believe this to be the first observation ofComment: 4 pages, 4 figures, to appear in Phys. Rev. Let

Evaluation of transporter-mediated hepatobiliary transport of newly developed ¹⁸F-labeled pitavastatin derivative, PTV-F1, in rats by PET imaging

Quantitative evaluations of the functions of uptake and efflux transporters directly in vivo is desired to understand an efficient hepatobiliary transport of substrate drugs. Pitavastatin is a substrate of organic anion transporting polypeptides (OATPs) and canalicular efflux transporters; thus, it can be a suitable probe for positron-emission tomography (PET) imaging of hepatic transporter functions. To characterize the performance of [¹⁸F]PTV-F1, an analogue of pitavastatin, we investigated the impact of rifampicin (a typical OATP inhibitor) coadministration or Bcrp (breast cancer resistance protein) knockout on [¹⁸F]PTV-F1 hepatic uptake and efflux in rats by PET imaging. After intravenous administration, [¹⁸F]PTV-F1 selectively accumulated in the liver, and the radioactivity detected in plasma, liver, and bile mainly derived from the parent PTV-F1 during the PET study (∼40 min). Coadministration of rifampicin largely decreased the hepatic uptake of [¹⁸F]PTV-F1 by 73%. Because of its lower clearance in rats, [¹⁸F]PTV-F1 is more sensitive for monitoring changes in hepatic OATP1B function that other previously reported OATP1B PET probes. Rifampicin coadministration also significantly decreased the biliary excretion of radioactivity by 65%. Bcrp knockout did not show a significant impact on its biliary excretion.[¹⁸F]PTV-F1 enables quantitative analysis of the hepatobiliary transport system for organic anions

Arterial Stiffness, Physical Activity, and Atrial Natriuretic Peptide Gene Polymorphism in Older Subjects

An increase in arterial stiffness with advancing age is associated with several pathological states, includinghypertension and arteriosclerosis. Regular exercise improves the aging-induced increase in arterial stiffnessand has a protective effect against these diseases. However, not all individuals respond to exerciseto the same extent. Atrial natriuretic peptide (ANP) is involved in the regulation of basal blood pressure,blood flow, and vascular tone. The present study was designed to clarify whether gene polymorphisms inANP-related genes affect exercise-induced improvements in arterial stiffness. We performed a cross-sectionalstudy of 291 healthy middle-aged and older Japanese subjects (63±1 years), examining the relationshipbetween daily physical activity–induced improvements in arterial stiffness, estimated by brachial-anklearterial pulse wave velocity (baPWV), and the gene polymorphisms of valine32methionine (V32M: 664G>A)in exon 1 of ANP and asparagine521aspartic acid (N521D: 1780A>G) in exon 8 of the ANP clearance receptor(NPR-C). The baseline baPWV was significantly lower in the active group, but no differences were seen inblood pressure. Active subjects with the ANP-VV genotype had significantly lower baPWV and higherplasma ANP levels compared with inactive subjects, but there were no variations related to the VM+MMgenotype. Additionally, baPWV and plasma ANP levels were negatively correlated in ANP-VV genotypesubjects, but were not correlated in VM+MM individuals. Our results suggest that ANP polymorphismin older Japanese subjects may affect the cardiovascular response to regular exercise

Estimation of Japanese sandeel (Ammodytes personatus) distribution in the northern coast of Hokkaido, Japan, using a quantitative echo sounder

The Japanese sandeel (Ammodytes personatus) is widely distributed in the coastal area of Japan, and especially in the summer months, they could be found in the northern coast of Hokkaido. Sandeel plays an important role in marine ecosystem and represents one of the most commercial coastal fisheries species in Japan. In order to get a better understanding of the Japanese sandeel distribution in the northern coast of Hokkaido for sandeel abundance estimation and management, fishery-independent method for sandeel distribution estimates is needed. The main objective of this study is to estimate the Japanese sandeel distribution in the northern coast of Hokkaido and the secondary objective is to characterize the suitable condition as sandeel habitat. The study area is located off Wakkanai, in the northern coast of Hokkaido, Japan. Acoustic surveys and measurement of oceanographic conditions were conducted in June 2010 and 2011 respectively. Sandeel distribution was estimated by species identification using the volume backscattering strength (SV) difference method. Target strength (TS) of sandeel was estimated by theoretical TS method (distorted-wave Born approximation, DWBA) and the mean and standard deviation for the tilt angle distribution were substituted into theoretical model. Using this TS values, echo trace of sandeel schools was converted to number of individual per unit area. Spatial patterns of sandeel schools were analyzed based on acoustic data and oceanographic conditions such as temperature, salinity, and depth. In this study, number of sandeel schools in 2010 was 8 and 11 schools in 2011, respectively. Most of sandeel abundance was found in the coastal area of 30 to 50 m in bottom depths, and they existed in the near sea bottom. In relation with oceanographic condition, this study showed that sandeel densities tended to be highest in the specific range of 9 - 10oC in temperature, and 33.8 - 33.9 psu in salinity. Probably, sandeel distribution was affected by the mixed water of Soya Warm Current (SWC) and East Sakhalin Current (ESC). From these results, there is a possibility that the oceanographic condition is an important factor for explaining the spatial distribution of Japanese sandeel in the northern coast of Hokkaido