92 research outputs found

    Deposition of Hard Chrome Coating onto Heat Susceptible Substrates by Low Power Microwave Plasma Spray

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    Microwave plasma spray requires relatively low power, which is lower than 1 kW in comparison to other plasma spraying method. Until now, we are able to deposit Cu and Hydroxyapatite coating onto heat susceptible substrate, CFRP which are difficult for conventional plasma spray due to the excessive heat input. In this paper, a hard chromium coating was deposited onto SUS304 and CFRP by a low power microwave plasma spray technique. By controlling the working gas flow rate and spraying distance, a hard chrome coating with thickness of approximately 30 μm was successfully deposited onto CFRP substrate with hardness of 1110 Hv0.05. Furthermore, the coating produced here is higher than that produced by hard chrome plating

    大腸癌における神経成長因子の発現

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    取得学位:博士(医学), 学位番号:医博甲第1380号,学位授与年月日:平成11年7月31日,学位授与年:199

    Preparation and Evaluation of Ordinary Attritor Milled Ti-Al Powders and Corresponding Thermal Sprayed Coatings

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    Ordinary attritor milling of elemental metallic powders under atmospheric condition was utilized to prepare desirable amount of powders for thermal spraying. The effect of different BPR (Ball to Powder weight Ratio) has been investigated in terms of nitridation during milling. To investigate the effect of heat treatment on the formation of dispersed phases, heat treatment to the powder was performed as well. Titanium aluminide coatings with carbonitride dispersed phases were successfully fabricated by low pressure plasma spraying. The hardness and specific wear of the coatings prepared by the powders with different milling conditions was measured so as to investigate the effect of the content of dispersed titanium based carbonitride phases. Experimental results show that the formation of dispersed carbonitride phases depends strongly on milling condition, irrespective of heat treated powders or thermal sprayed coatings, and directly affects the mechanical properties of the coatings. Compared with the phase composition of heated powders and corresponding thermal sprayed coatings, it seems that the temperature of processing the MA powders is also a decisive factor on the phase formation, especially carbonitride phases and oxide phase

    Influence of Annealed Aluminum Properties on Adhesion Bonding of Cold Sprayed Titanium Dioxide Coating

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    It is well known that cold spraying ceramic materials can be difficult because cold spraying requires plastic deformation of the feedstock particles for adhesion to the substrate. The challenge lies in the difficulty of plastically deforming hard and brittle ceramic materials, such as TiO2. Previous studies have reported the possibility of cold spraying thick pure TiO2 but the bonding mechanism of cold sprayed TiO2 is not fully understood. The factor like substrate condition as oxide film thickness and mechanical properties may also affect cold spray deposition but not fully understood in cold spraying ceramic. The aim of the present research is to investigate the correlation between the oxide thickness and substrate deformation with the adhesion strength of cold-sprayed TiO2 coatings toward the bonding mechanism involved. Relevant experiments were executed using Al 1050, subjected to various annealing temperatures and cold-sprayed with TiO2 powder. The results indicate a decreasing trend of coating adhesion strength with increasing annealed substrate temperature from room temperature to 400°C annealed. Metallurgical bonding is pronounced as bonding mechanism involved between TiO2 particle and annealed 1050 substrate

    Concordance of acquired mutations between metastatic lesions and liquid biopsy in metastatic colorectal cancer

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    Aim: To evaluate whether PCR-reverse sequence-specific oligonucleotide can examine the concordance between liquid biopsy and metastatic lesions with acquired resistance. Materials & methods: We examined acquired mutations in chemoresistant lesions and blood obtained from four patients with RAS wildtype metastatic colorectal cancer who underwent treatment with anti-epidermal growth factor receptor antibodies. Results: In one patient, metastatic lesions harbored diverse acquired mutations in KRAS in all seven metastases; the two acquired mutations were detectable in blood collected after the patient acquired resistance. None of the other patients exhibited liquid biopsy mutations, except one, with a BRAF mutation confirmed in primary tumor and peritoneal dissemination. Conclusion: Liquid biopsy based on PCR-reverse sequence-specific oligonucleotide is a successful procedure for capturing acquired mutations with precise information on the RAS mutational spectrum

    Epigenetic biomarkers for prediction of sensitivity to chemotherapeutic drugs in multiple myeloma

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    Multiple myeloma continues to be a lethal malignancy despite the development of treatments such as high-dose chemotherapy combined with stem cell transplantation. Multiple myeloma arises through an accumulation of multiple genetic anges, including immunoglobulin gene rearrangements involved in Cyclin D. The main difficulties in multiple myeloma treatments are drug-resistance. DNA methylation of the5\u27 CpG islands of genes is often found in multiple myeloma. To screen for he genes involved in tumorigenesis of multiple myeloma, which are silenced by DNA methylation, we performed cDNA microarray analysis using multiple myeloma cell lines treated with demethylating agent5-aza-2-deoxycytidine (DAC), and entified RASD1, a dexamethasone (Dex)-inducible gene, as one of the targets of epigenetic changes. Inactivation of RASD1 was found to correlate with resistance to Dex, and treatment of multiple myeloma cells with DAC restored sensitivity to Dex. These findings suggest the involvement of epigenetic gene silencing in multiple myeloma progression and drug-resistance, and the usefulness of demethylation therapy for multiple myeloma treatment. Furthermore, DNA methylation can be an epigenetic biomarker for multiple myeloma

    ADAR1 is a promising risk stratification biomarker of remnant liver recurrence after hepatic metastasectomy for colorectal cancer

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    Adenosine-to-inosine RNA editing is a process mediated by adenosine deaminases that act on the RNA (ADAR) gene family. It has been discovered recently as an epigenetic modification dysregulated in human cancers. However, the clinical significance of RNA editing in patients with liver metastasis from colorectal cancer (CRC) remains unclear. The current study aimed to systematically and comprehensively investigate the significance of adenosine deaminase acting on RNA 1 (ADAR1) expression status in 83 liver metastatic tissue samples collected from 36 patients with CRC. The ADAR1 expression level was significantly elevated in liver metastatic tissue samples obtained from patients with right-sided, synchronous, or RAS mutant-type CRC. ADAR1-high liver metastasis was significantly correlated with remnant liver recurrence after hepatic metastasectomy. A high ADAR1 expression was a predictive factor of remnant liver recurrence (area under the curve = 0.72). Results showed that the ADAR1 expression level could be a clinically relevant predictive indicator of remnant liver recurrence. Patients with liver metastases who have a high ADAR1 expression requires adjuvant chemotherapy after hepatic metastasectomy

    Association between the examination rate of treatment-resistant schizophrenia and the clozapine prescription rate in a nationwide dissemination and implementation study

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    Background: The decision to initiate clozapine treatment should be made on an individual basis and may be closely related to the early detection of treatment-resistant schizophrenia (TRS), although there is evidence that the early use of clozapine results in a better response to treatment. Therefore, we investigated the relationship between the examination rate of TRS and the prescription rate of clozapine. Methods: After attending a 1-day educational program on schizophrenia based on the "Guidelines for the Pharmacological Treatment of Schizophrenia," we asked the participating facilities to submit records of whether or not TRS was evaluated for each patient. We calculated the clozapine prescription rate from the schizophrenic patients prescribed clozapine and all of the schizophrenic patients. Forty-nine facilities in 2017 were included in the study. Results: There were dichotomous distributions in the examination rate of TRS and a non-normal distribution in the prescription rate of clozapine. There was a significant correlation between the prescription rate of clozapine and the examination rate of TRS (r s = 0.531, P = 1.032 × 10−4). A significant difference was found in the prescription rate of clozapine between the three groups of facilities according to the examination rate of TRS. Conclusion: As a preliminary problem for the use of clozapine, in Japan, the examination rate of TRS varies, and there are many facilities that typically do not consider the possibility of TRS; this trend leads to a low rate of clozapine use. Clearly, further clinician training is needed for the early detection and appropriate management of TRS that includes an explanation of TRS and how to introduce clozapine therapy to patients and their families
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