•Flow accelerated corrosion rates at an elbow pipe were measured in a test loop.•FAC rates increased as flow velocity increased non-linearly.•FAC rate was not negligible value when the water ...temperature was 50 °C.•The influence of flow velocity was negligible at 50 °C and remarkable over 100 °C.•The combination effect of flow velocity and temperature was strong at the elbow.
Flow accelerated corrosion (FAC) is one of the important issues that must be considered for aging fossil and nuclear power plants. To understand the effect of thermal flow field on FAC, FAC rates at an elbow pipe were measured under different flow velocity and temperature conditions. The elbow test section was made of stainless steel (diameter D = 49.5 mm) and FAC rates were measured using corrosion sensors made of carbon steel. The dissolved oxygen concentration was kept under 0.1 μg/kg, and pH was nearly neutral (about 7.0) at room temperature. The mean cross-sectional velocity was changed from 0.39 to 5.74 m/s (Reynolds number, about 1.0e6). When the water temperature was about 150 °C, the FAC rate was smaller at the intrados of the elbow pipe than at other circumferential locations. This tendency continued downstream. The FAC rates at the elbow pipe were larger than those upstream and downstream from the elbow pipe and the FAC rates downstream from the elbow pipe decreased along the flow direction. FAC rates increased as flow velocity increased and their relationship was not linear. The ratios of the maximum FAC rate at the elbow to the FAC rate in the upstream straight pipe ranged from about 1.7 to 2.9. When temperature decreased to 100 °C, FAC rate at the intrados became the largest of the other circumferential sensors. When temperature decreased further to 50 °C, FAC rate also decreased, but the value was not negligible. The influence of flow velocity was negligibly small at 50 °C and remarkable at 100 °C and 150 °C. The combination effect of flow velocity and temperature was different from place to place and particularly strong at the elbow.
Background
The rapid determination of the fatigue limit using temperature second harmonic, which is the temperature variation with twice the frequency of the cyclic load, is attractive in terms of ...time and cost effectiveness. However, the temperature second harmonic contains non-fatigue-related factors (e.g., internal friction and load second harmonic), in addition to fatigue-related factors (e.g., plastic deformation); therefore, this presents challenges in uniquely determining the fatigue limit.
Objective
An experimental procedure for uniquely determining the fatigue limit based on temperature second harmonic measurements is developed.
Methods
In the developed procedure, the temperature second harmonic amplitude is accurately measured using the present phase double frequency (2
f
) lock-in thermography, and the fatigue limit is then uniquely determined based on the generation mechanism of the temperature second harmonic. The present phase 2
f
lock-in thermography requires only simple post-processing, considering the phase information of both the non-fatigue-related and fatigue-related factors. The fatigue limit estimation accuracies of the developed procedure and four existing methods are quantitatively evaluated in comparison with the actual fatigue limit for heat-treated carbon steel plate specimens subjected to annealing, normalizing, and quenching–tempering.
Results
By performing simple post-processing, the present phase 2
f
lock-in thermography easily eliminates the influence of internal friction and load second harmonic. The developed procedure exhibits the second-best estimation accuracies among all the methods for all the heat-treated specimens.
Conclusions
The developed procedure is validated through its reasonable estimation accuracy.
Anucleate platelets can undergo apoptosis in response to various stimuli, as do nucleated cells. Cardiopulmonary bypass (CPB) causes platelet dysfunction and can also activate platelet apoptotic ...pathways. We therefore evaluated time-dependent changes in blood platelet Bax (a pro-apoptotic molecule) levels and platelet dysfunction after cardiac surgery.
We assessed blood samples obtained from subjects having on-pump or off-pump coronary artery bypass graft surgery (n=20 each). We also evaluated the in vitro effects of platelet Bax increase in eight healthy volunteers.
Thrombin-induced platelet calcium mobilisation and platelet-surface glycoprotein Ib (GPIb) expression were lowest at weaning from CPB and did not recover on postoperative day one. On-pump surgery increased platelet expression of Bax, especially the oligomerised form, along with translocation of Bax from the cytosol to mitochondria and platelet-surface tumour necrosis factor-alpha (TNF-α)–converting enzyme (TACE) expression. In contrast, mitochondrial cytochrome c expression was reduced. While similar in direction, the magnitude of the observed changes was smaller in patients having off-pump surgery. In vitro, a cell-permeable Bax peptide increased platelet Bax expression to the same extent seen during bypass and produced similar platelet changes. These apoptotic-like changes were largely reversed by Bcl-xL pre-administration, and were completely reversed by combined application of inhibitors that stabilise outer mitochondrial membrane permeability and TACE.
CPB increases platelet Bax expression, which contributes to reduced platelet-surface GPIb expression and thrombin-induced platelet calcium changes. These changes in platelet apoptotic signalling might contribute to platelet dysfunction after CPB.
UMIN Clinical Trials Registry (number UMIN000006033).
Several human cancers have been found to contain cancer stem-like cells (CSCs) having cancer-initiating ability. However, only a few reports have shown the existence of CSCs in bone and soft tissue ...sarcomas. In this study, we identified and characterised side population (SP) cells that showed drug-resistant features in human bone sarcoma cell lines.
In seven osteosarcoma cell lines (OS2000, KIKU, NY, Huo9, HOS, U2OS and Saos2) and in one bone malignant fibrous histiocytoma (MFH) cell line (MFH2003), the frequency of SP cells was analysed. Tumourigenicity of SP cells was assessed in vitro and in vivo. Gene profiles of SP cells and other populations (main population; MP) of cells were characterised using cDNA microarrays.
SP cells were found in NY (0.31%) and MFH2003 (5.28%). SP cells of MFH2003 formed spherical colonies and re-populated into SP and MP cells. In an NOD/SCID mice xenograft model, 1 x 10(3) sorted SP cell-induced tumourigenesis. cDNA microarray analysis showed that 23 genes were upregulated in SP cells.
We showed that SP cells existed in bone sarcoma cell lines. SP cells of MFH2003 had cancer-initiating ability in vitro and in vivo. The gene profiles of SP cells could serve as candidate markers for CSCs in bone sarcomas.
Summary
Among the functional disabilities that patients face following maxillectomy, speech impairment is a major factor influencing quality of life. Proper rehabilitation of speech, which may ...include prosthodontic and surgical treatments and speech therapy, requires accurate evaluation of speech intelligibility (SI). A simple, less time‐consuming yet accurate evaluation is desirable both for maxillectomy patients and the various clinicians providing maxillofacial treatment. This study sought to determine the utility of digital acoustic analysis of vowels for the prediction of SI in maxillectomy patients, based on a comprehensive understanding of speech production in the vocal tract of maxillectomy patients and its perception. Speech samples were collected from 33 male maxillectomy patients (mean age 57.4 years) in two conditions, without and with a maxillofacial prosthesis, and formant data for the vowels /a/,/e/,/i/,/o/, and /u/ were calculated based on linear predictive coding. The frequency range of formant 2 (F2) was determined by differences between the minimum and maximum frequency. An SI test was also conducted to reveal the relationship between SI score and F2 range. Statistical analyses were applied. F2 range and SI score were significantly different between the two conditions without and with a prosthesis (both P < .0001). F2 range was significantly correlated with SI score in both the conditions (Spearman's r = .843, P < .0001; r = .832, P < .0001, respectively). These findings indicate that calculating the F2 range from 5 vowels has clinical utility for the prediction of SI after maxillectomy.
In allo-stem cell transplantation (SCT), it is unclear whether donor-specific anti-HLA Abs (DSAs) can actually mediate graft rejection or if they are simply surrogate markers for the cellular ...immunity that causes graft rejection. Here, we first analyzed a case of cord blood allograft rejection in which DSA and cytotoxic T lymphocyte (CTL) specific for donor HLA-B*54:01 were detected at the time of graft rejection. Both the DSA and CTL inhibited colony formation by unrelated bone marrow mononuclear cells sharing HLA-B*54:01, suggesting that the humoral and cellular immune responses were involved in the graft rejection. Interestingly, the DSA and CTL were also detected in cryopreserved pre-transplant patient blood, raising a hypothesis that the presence of anti-HLA Abs could be an indicator for corresponding HLA-specific T cells. We then evaluated the existence of HLA-specific CD8(+) T cells in other patient blood specimens having anti-HLA class I Abs. Interferon-γ enzyme-linked immunospot assays clearly confirmed the existence of corresponding HLA-specific T-cell precursors in three of seven patients with anti-HLA Abs. In conclusion, our data demonstrate that integrated humoral and cellular immunity recognizing the same alloantigen of the donor can mediate graft rejection in DSA-positive patients undergoing HLA-mismatched allo-SCT. Further studies generalizing our observation are warranted.
We sought to determine the incidence of RFDD in patients receiving dupilumab and the rate of resolution of RFDD after expanded series patch testing (ESPT) and allergen avoidance.
This is a ...retrospective chart review of 80 patients with atopic dermatitis who were evaluated for RFDD after treatment with dupilumab. Expanded series patch testing findings and response to allergen avoidance were assessed in the subset of patients with RFDD who subsequently underwent ESPT while continuing to receive dupilumab.
Forty-nine patients (61.3%) experienced facial dermatitis before initiating dupilumab. Thirty-five patients (43.8%) experienced RFDD after starting dupilumab. Of the 14 patients with RFDD who received ESPT, 92.9% had 1 or more relevant positive patch test results, with 50% of such patients being mostly to completely clear of facial dermatitis after allergen avoidance. Importantly, 50.6% of the positive reactions to allergens were not included on the North American Contact Dermatitis Group Core 80.
Many patients with RFDD benefit from patch testing and subsequent allergen avoidance. Expanded series patch testing should be offered to patients who experience RFDD after beginning dupilumab therapy to ensure that such patients have eliminated any exogenous component of their dermatitis, such as concomitant allergic contact dermatitis.
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