105 research outputs found
Influence of Inclusion Type on Internal Fatigue Fracture under Cyclic Shear Stress
AbstractFour kinds of high carbon chromium steel were conducted to ultrasonic torsional fatigue test and the fracture surfaces and the cross-sections of fracture origin were observed. Internal fatigue fracture was occurred from oxide inclusion and MnS, and ODA was found surrounding inclusion. The behaviors of the crack initiation and propagation were different depending on inclusion types. Thus the characteristics of inclusion influence to fatigue properties
Examination of High-Torque Sandwich-Type Spherical Ultrasonic Motor Using with High-Power Multimode Annular Vibrating Stator
Spherical ultrasonic motors (SUSMs) that can operate with multiple degrees of freedom (MDOF) using only a single stator have high holding torque and high torque at low speed, which makes reduction gearing unnecessary. The simple structure of MDOF-SUSMs makes them useful as compact actuators, but their development is still insufficient for applications such as joints of humanoid robots and other systems that require MDOF and high torque. To increase the torque of a sandwich-type MDOF-SUSM, we have not only made the vibrating stator and spherical rotor larger but also improved the structure using three design concepts: (1) increasing the strength of all three vibration modes using multilayered piezoelectric actuators (MPAs) embedded in the stator, (2) enhancing the rigidity of the friction driving portion of the stator for transmitting more vibration force to the friction-driven rotor surface, and (3) making the support mechanism more stable. An MDOF-SUSM prototype was tested, and the maximum torques of rotation around the X(Y)-axis and Z-axis were measured as 1.48 N?m and 2.05 N?m, respectively. Moreover, the values for torque per unit weight of the stator were obtained as 0.87 N?m/kg for the X(Y)-axis and 1.20 N?m/kg for the Z-axis. These are larger than values reported for any other sandwich-type MDOF-SUSM of which we are aware. Hence, the new design concepts were shown to be effective for increasing torque. In addition, we measured the transient response and calculated the load characteristics of rotation around the rotorâs three orthogonal axes
Development of electromagnetic and piezoelectric hybrid actuator system
An ordinal force-feedback device typically uses an electromagnetic motor (EMM), which provides an excellent expression of elasticity. However, it is not easy to express the sense of hardness and roughness because the response of the current is delayed due to the inductance of the armature winding. On the contrary, a piezoelectric actuator, which has a rapid response, is good at expressing the sense of hardness and roughness. Thus, if different types of actuators are used in the same actuator system (AS), the weaknesses of each type can be compensated for. In this study, as an ideal force-feedback device, a hybrid actuator system combining an EMM with an ultrasonic motor (USM) and a piezoelectric clutch/brake (piezo-clutch/brake) is proposed and examined. This AS can expand the range of representable feelings. This paper describes the construction of a hybrid AS and some experimental results of a force-feedback display. In this experiment, the feelings of roughness, friction, and elasticity were represented. The feeling of roughness was represented by the on-off control of the piezo-brake at defined positions. The feeling of friction was represented by the PID control of braking using the piezo-clutch. The feeling of elasticity was represented by two methods: the use of the EMM and brake and the use of a combination of the USM, clutch, and brake. As a result, the hardness feeling was realistically represented by the piezo-brake, and the elastic feeling was represented by either the EMM or the USM
A simplified PCR assay for fast and easy mycoplasma mastitis screening in dairy cattle
A simplified polymerase chain reaction (PCR) assay was developed for fast and easy screening of mycoplasma mastitis in dairy cattle. Species of major mycoplasma strains [Mycoplasma (M.) bovis, M. arginini, M. bovigenitalium, M. californicum, M. bovirhinis, M. alkalescens and M. canadense] in cultured milk samples were detected by this simplified PCR-based method as well as a standard PCR technique. The minimum concentration limit for detecting mycoplasma by the simplified PCR was estimated to be about 2.5 Ă 103 cfu/mL and was similar to that of the standard PCR. We compared the specificity and sensitivity of the simplified PCR to those of a culture method. Out of 1,685 milk samples cultured in mycoplasma broth, the simplified PCR detected Mycoplasma DNA in 152 that were also positive according to the culture assay. The sensitivity and specificity of the simplified PCR were 98.7% and 99.7%, respectively, for detecting mycoplasma in those cultures. The results obtained by the simplified PCR were consistent with ones from standard PCR. This newly developed simplified PCR, which does not require DNA purification, can analyze about 300 cultured samples within 3 h. The results from our study suggest that the simplified PCR can be used for mycoplasma mastitis screening in large-scale dairy farms
Support vector machines as multivariate calibration model for prediction of blood glucose concentration using a new non-invasive optical method named pulse glucometry
éæȹ性ćŠçć·„ç 究ćæ©æą°ć·„ćŠçł»A novel optical non-invasive in vivo blood glucose concentration (BGL) measurement technique, named "Pulse Glucometry", was combined with a kernel method; support vector machines. The total transmitted radiation intensity (Iλ) and the cardiac-related pulsatile changes superimposed on Iλ in human adult fingertips were measured over the wavelength range from 900 to 1700 nm using a very fast spectrophotometer, obtaining a differential optical density (ÎOD λ) related to the blood component in the finger tissues. Subsequently, a calibration model using paired data of a family of ÎODλs and the corresponding known BGLs was constructed with support vector machines regression instead of using calibration by a conventional partial least squares regression (PLS). Our results show that the calibration model based on the support vector machines can provide a good regression for the 183 paired data, in which the BGLs ranged from 89.0-219 mg/dl (4.94-12.2 mmol/l). The resultant regression was evaluated by the Clarke error grid analysis and all data points fell within the clinically acceptable regions (region A: 93%, region B: 7%). © 2007 IEEE.
Suzaku Observations of the Centaurus Cluster: Absence of Bulk Motions in the Intracluster Medium
The Centaurus cluster (z=0.0104) was observed with the X-ray Imaging
Spectrometer (XIS) onboard the Suzaku X-ray satellite in three pointings, one
centered on the cluster core and the other two offset by +-8' in declination.
To search for possible bulk motions of the intracluster medium, the central
energy of He-like Fe-K line (at a rest-frame energy of 6.7 keV) was examined to
look for a positional dependence. Over spatial scales of 50 kpc to 140 kpc
around the cluster core, the central line energy was found to be constant
within the calibration error of 15 eV. The 90% upper limit on the line-of-sight
velocity difference is |Delta_v|< 1400 km/s, giving a tighter constraint than
previous measurements. The significant velocity gradients inferred from a
previous Chandra study were not detected between two pairs of rectangular
regions near the cluster core. These results suggest that the bulk velocity
does not largely exceed the thermal velocity of the gas in the central region
of the Centaurus cluster. The mean redshift of the intracluster medium was
determined to be 0.0097, in agreement with the optical redshift of the cluster
within the calibration uncertainty. Implications of the present results for the
estimation of the cluster mass are briefly discussed.Comment: 9 pages, 4 figures. Accepted for publication in PASJ. Version with
high-quality color figures at
http://cosmic.riken.jp/ota/publications/index.htm
Successful intrathecal chemotherapy combined with radiotherapy followed by pomalidomide and low-dose dexamethasone maintenance therapy for a primary plasma cell leukemia patient
Primary plasma cell leukemia (PPCL) is a rare aggressive variant of plasma cell disorder and frequently presents with extramedullary disease. Central nervous system (CNS) involvement with PPCL has an extremely poor prognosis. We describe a 46-year-old man with PPCL treated with a combination of lenalidomide, bortezomib, and dexamethasone as induction therapy following upfront allogeneic stem cell transplantation (allo-SCT). Despite achieving a very good partial response, the patient suffered from an isolated CNS relapse 12 months after allo-SCT. He was immediately started on concurrent intrathecal chemotherapy (IT) and cranial irradiation (RT). Subsequently, pomalidomide and low-dose dexamethasone (Pd) were given as maintenance therapy. He has been without CNS recurrence for more than 18 months. Our case suggests that concurrent IT and RT followed by Pd maintenance therapy may be an effective option to control CNS relapse of PPCL after allo-SCT
Detection of epidermal growth factor receptor mutations in exhaled breath condensate using droplet digital polymerase chain reaction
The detection of certain oncogenic driver mutations, including those of epidermal growth factor receptor (EGFR), is essential for determining treatment strategies for advanced nonâsmall cell lung cancer (NSCLC). The current study assessed the feasibility of testing exhaled breath condensate (EBC) for EGFR mutations by droplet digital PCR (ddPCR). Samples were collected from 12 patients with NSCLC harboring EGFR mutations that were admitted to Okayama University Hospital between June 1, 2014 and December 31, 2017. A total of 21 EBC samples were collected using the RTubeâą method and EGFR mutations (L858R, exon 19 deletions or T790M) were assessed through ddPCR analysis (EBCâddPCR). A total of 3 healthy volunteer samples were also tested to determine a threshold value for each mutation. Various patient characteristics were determined, including sex (3 males and 9 females), age (range 54â81 years; median, 66 years), smoking history (10 had never smoked; 2 were former smokers), histology (12 patients exhibited adenocarcinoma), clinical stage (9 patients were stage IV; 3 exhibited postâoperative recurrence) and EGFR mutation type (4 had L858R; 8 had exon 19 deletions; 8 had T790M). EBCâddPCR demonstrated positive droplets in 8 of the 12 patients. The sensitivity and specificity of each mutation was as follows: 27.3 and 80.0% for EGFR L858R, 30.0 and 90.9% for EGFR Ex19del, and 22.2 and 100% for EGFR T790M. EBCâddPCR analysis of EGFR mutations exhibited modest sensitivity and acceptable specificity. EBCâddPCR is a minimally invasive and replicable procedure and may be a complementary method for EGFR testing in patients where blood or tissue sampling proves difficult
Phase I clinical study of anti-apoptosis protein, survivin-derived peptide vaccine therapy for patients with advanced or recurrent colorectal cancer
Survivin is a member of the inhibitor of apoptosis protein (IAP) family containing a single baculovirus IAP repeat domain. It is expressed during fetal development but becomes undetectable in terminally differentiated normal adult tissues. We previously reported that survivin and its splicing variant survivin-2B was expressed abundantly in various types of tumor tissues as well as tumor cell lines and was suitable as a target antigen for active-specific anti-cancer immunization. Subsequently, we identified an HLA-A24-restricted antigenic peptide, survivin-2B80-88 (AYACNTSTL) recognized by CD8+ cytotoxic T lymphocytes (CTLs). We, therefore, started a phase I clinical study assessing the efficacy of survivin-2B peptide vaccination in patients with advanced or recurrent colorectal cancer expressing survivin. Vaccinations with survivin-2B peptide were given subcutaneously six times at 14-day intervals. Of 15 patients who finished receiving the vaccination schedule, three suffered slight toxicities, including anemia (grade 2), general malaise (grade 1), and fever (grade 1). No severe adverse events were observed in any patient. In 6 patients, tumor marker levels (CEA and CA19-9) decreased transiently during the period of vaccination. Slight reduction of the tumor volume was observed in one patient, which was considered a minor responder. No changes were noted in three patients while the remaining eleven patients experienced tumor progression. Analysis of peripheral blood lymphocytes of one patient using HLA-A24/peptide tetramers revealed an increase in peptide-specific CTL frequency from 0.09% to 0.35% of CD8+ T cells after 4 vaccinations. This phase I clinical study indicates that survivin-2B peptide-based vaccination is safe and should be further considered for potential immune and clinical efficacy in HLA-A24-expression patients with colorectal cancer
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