The effect of passengers on a railway vehicle is usually considered as additional mass in designing a carbody. However, previous studies by means of stationary excitation tests or running tests using ...actual vehicles indicate that passengers behave not as mass but as damping. In this paper, the authors examined the passengers' damping effect under controlled excitation conditions on a roller rig through a series of excitation tests using a commuter-type vehicle. Large and multi-modal reductions of flexural vibrations of the carbody were observed when passengers existed. Influences of the number of passengers, distributions and postures of passengers were investigated. The authors also tried to mimic the damping effect by passengers using flexible tanks filled with fluids. Three kinds of fluids which have different viscosities have been tested. As a result of the excitation tests, good vibration reduction effects were observed by applying those tanks, and it has been found that the flexible tanks filled with fluids bring about vibration reduction effect (including multi-modal reduction) which is equal to or rather better than the case of similar mass of passengers in the carbody; the difference of viscosity gave little affect on the damping abilities. From these measurement results, a possibility of realising effective damping devices against flexural vibrations of railway vehicle carbodies representing passengers damping effect, in a simple, economical and environmental friendly way, has been demonstrated.
Yaw damper represents a major source of excitation for flexural vibration of the railway carbody. In order to reduce transmissibility of such undesired excitation, yaw damper should allow for large ...force transmission at low working frequencies, but should behave as vibration isolator at high working frequencies. Unfortunately, the yaw oil damper (OD), which is nowadays in service, has poor intrinsic elastic capabilities and provides damping forces varying as a power function versus the piston speed. Since colloidal damper (CD) has intrinsic elastic capabilities and larger damping forces at lower excitation frequencies, it occurs as an attractive alternative solution to traditional yaw dampers. In this work, a yaw CD destined to carbody suspension of a bullet train was designed and manufactured; then, its dynamic characteristics, produced by both the frictional and colloidal effects, were evaluated from the experimental results, obtained during horizontal vibration tests, performed on a ball-screw shaker. Compared to the corresponding classical yaw OD, the trial yaw CD allowed for: weight reduction of 31.6%; large damping force, dissipated energy and spring constant at long piston stroke under low excitation frequency; low damping force, dissipated energy and spring constant at short piston stroke under high excitation frequency. Elastic properties were justified by introducing a model for the spring constant that included the effect of pore size distribution.
In some countries, the red fox Vulpes vulpes has been rapidly expanding its range into urban and suburban areas, where it is referred to as the ‘urban fox’. In the city of Sapporo, northern Japan, ...the population of urban foxes has been increasing since the 1990s. Because the red fox carries several zoonoses, it is important to understand its population structure and migration status in urban areas, for not only basic biology but also public health. In this study, to clarify population genetic structure and gene flow, we examined the genotypes of nine microsatellite loci for 578 road‐killed foxes collected in and around residential areas of Sapporo from 2002 to 2014 (except for 2009 and 2010). Based on the genotype data and spatial information for the sampled animals, we detected three subpopulations within the urban fox population. Boundaries separating the three subpopulations were a river and a railway crossing in central Sapporo. The subpopulations separated by the railway were more genetically differentiated than those separated by the river, and the railway, which is surrounded by crowded roads, may have had a greater effect on gene flow and genetic differentiation. Levels of genetic differentiation among the subpopulations in Sapporo, however, were lower than those of urban fox populations studied in other countries. Our results suggest that there is weak gene flow among the subpopulations in Sapporo.
The urban fox (Vulpes vulpes) has been rapidly expanding its range in Sapporo, northern Japan. Our population genetic study using microsatellite genotypes revealed that the boundaries separating three subpopulations are a river and a railway crossing in central Sapporo although there is weak gene flow, leading to a low level of genetic differentiation among them. Photo credit: Kohji Uraguchi.
Abstract Natriuretic peptide receptor A (NPRA) is one of the natriuretic peptide receptors. NPRA has been reported to play a role in the carcinogenesis of various tumours, as well as functional roles ...in renal, cardiovascular, endocrine, and skeletal homeostasis. The clinicopathological significance of NPRA in tongue squamous cell carcinoma (TSCC) was examined in this study. The overexpression of NPRA was more frequent in TSCC (21/58, 36.2%) than in the normal oral epithelium (0/10, 0%) ( P < 0.05). It was also more frequently observed in cancers with higher grades according to the pattern of invasion (grades 1–2 vs. grades 3–4, P < 0.01). Additionally, there was a tendency towards an association between the N classification and NPRA expression (N0 vs. N1–2, P = 0.06). Significant correlations were also observed between the expression of NPRA and that of VEGF-A ( P < 0.001) and VEGF-C ( P < 0.001). The high-NPRA expression group had a significantly poorer prognosis, with a 5-year disease-specific survival rate of 39.7%, compared to 97.0% in the low-expression group ( P < 0.001). Multivariate analysis suggested that the overexpression of NPRA may also be an independent prognostic factor ( P < 0.05). In conclusion, NPRA is associated with VEGF expression levels, invasion, and metastasis, and may be a prognostic factor in TSCC patients.
Children frequently suffer transient cerebral ischaemia during cardiac surgery. We measured cerebral ischaemia in children during cardiac surgery by combining two methods of monitoring.
We studied 65 ...children aged between 5 months and 17 yr having surgery to correct non-cyanotic heart disease using hypothermic cardiopulmonary bypass (CPB). During surgery, we measured the Bispectral Index (BIS) and regional cerebral haemoglobin oxygen saturation (SrO2) with near-infrared spectroscopy (NIRS). Cerebral ischaemia was diagnosed if both SrO2 and BIS decreased abruptly when acute hypotension occurred. In each patient, the relationship between SrO2 and arterial blood pressure (AP) was indicated by a plot of mean SrO2 against simultaneous mean AP.
We noted 72 episodes of cerebral ischaemia in 38 patients. Sixty-three ischaemic events were during CPB. Cerebral ischaemia was less frequent in older patients. Cerebral ischaemia was more common and more frequent in children under 4 yr old. Haematocrit during CPB was lower and SrO2 was more dependent on AP in children under 4 yr.
Children less than 4 yr of age are more likely to have cerebral ischaemia caused by hypotension during cardiac surgery. Ineffective cerebral autoregulation and haemodilution during CPB may be responsible.
An analytical method to investigate the three-dimensional (3D) flexural vibration of railway vehicle car bodies is presented in this article. In the method, a car body is modeled as a box-type ...structure consisting of plates and beams. The condition to connect components is satisfied by introducing artificial springs at their joints. The detailed analytical procedure is described. Some numerical calculations are carried out employing a commuter vehicle, which has a stainless steel car body, as an example. The numerical results are compared with the measured data to evaluate the validity of the model. Although the target vehicle has complicated mode shapes, it is shown that the analytical model can express such 3D vibration mode shapes successfully. It is also demonstrated that a good agreement is observed between the calculation results by the above method and the measured data for both stationary excitation and running test.
Post-operative concurrent chemoradiotherapy significantly improves the rates of locoregional control and disease-free survival in high-risk patients but has significant adverse effects. Percutaneous ...endoscopic gastrostomy and opioid-based pain control increase treatment completion rates but can result in dysphagia.
The rate and duration of use of prophylactically placed percutaneous endoscopic gastrostomies were evaluated in 43 patients who underwent post-operative radiotherapy or chemoradiotherapy from April 2007 through March 2010. All patients completed treatment and received 60 Gy or more of radiotherapy.
Thirty four of 43 patients (79.1%) used percutaneous endoscopic gastrostomies, which could later be removed in 25 of 34 patients. The median period of use was 108 days. Only one disease-free patient was permanently dependent on percutaneous endoscopic gastrostomy feeding. The frequency of percutaneous endoscopic gastrostomy use among patients with oral, oropharyngeal and hypopharyngeal cancer was 91.7, 100 and 54.5%, respectively.
Prolonged percutaneous endoscopic gastrostomy use is not required in patients receiving post-operative chemoradiotherapy and will not lead to dysphagia.
The spatial resolution along the pad-row direction was measured with a GEM-based TPC prototype for the future linear collider experiment in order to understand its performance for tracks with finite ...projected angles with respect to the pad-row normal. The degradation of the resolution due to the angular pad effect was confirmed to be consistent with the prediction of a simple calculation taking into account the cluster-size distribution and the avalanche fluctuation.
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