In-Situ SEM Observation and DIC Strain Analysis for Deformation and Cracking of Hot-Dip ZnMgAl Alloy Coating

( Naoki Takata ),( Hiroki Yokoi ),( Dasom Kim ),( Asuka Suzuki ),( Makoto Kobashi ) 한국부식방식학회 2024 Corrosion Science and Technology Vol.23 No.2

An attempt was made to apply digital image correlation (DIC) strain analysis to in-situ scanning electron microscopy (SEM) observations of bending deformation to quantify local strain distribution inside a ZnMgAl-alloy coating in deformation. Interstitial-free steel sheets were hot-dipped in a Zn-3Mg-6Al (mass%) alloy melt at 400 ℃ for 2 s. The specimens were deformed using a miniature-sized 4-point bending test machine inside the SEM chamber. The observed in situ SEM images were used for DIC strain analysis. The hot-dip ZnMgAl-alloy coating exhibited a solidification microstructure composed of a threephase eutectic of fine Al (fcc), Zn (hcp), and Zn₂Mg phases surrounding the primary solidified Al phases. The relatively coarsened Zn₂Mg phases were locally observed inside the ZnMgAl-alloy coating. The DIC strain analysis revealed that the strain was localized in the primary solidified Al phases and fine eutectic microstructure around the Zn₂Mg phase. The results indicated high deformability of the multi-phase microstructure of the ZnMgAl-alloy coating.

A Novel Mismatched PCR-Restriction Fragment Length Polymorphism Assay for Rapid Detection of gyrA and parC Mutations Associated With Fluoroquinolone Resistance in Acinetobacter baumannii

Naoki Kakuta,Ryuichi Nakano,Akiyo Nakano,Yuki Suzuki,Ayako Tanouchi,Takashi Masui,Saori Horiuchi,Shiro Endo,Risako Kakuta,Yasuo Ono,Hisakazu Yano 대한진단검사의학회 2020 Annals of Laboratory Medicine Vol.40 No.1

Background: Mutations in the quinolone resistance-determining regions (QRDRs) of Acinetobacter baumannii DNA gyrase (gyrA) and topoisomerase IV (parC) are linked to fluoroquinolone (FQ) resistance. We developed a mismatched PCR-restriction fragment length polymorphism (RFLP) assay to detect mutations in the gyrA and parC QRDRs associated with FQ resistance in A. baumannii. Methods: Based on the conserved sequences of A. baumannii gyrA and parC, two primer sets were designed for mismatched PCR-RFLP to detect mutations in gyrA (codons 83 and 87) and parC (codons 80 and 84) by introducing an artificial restriction enzyme cleavage site into the PCR products. This assay was evaluated using 58 A. baumannii strains and 37 other Acinetobacter strains that have been identified by RNA polymerase β-subunit gene sequence analysis. Results: PCR amplification of gyrA and parC was successful for all A. baumannii strains. In 11 FQ -susceptible strains, the gyrA and parC PCR products were digested by the selected restriction enzymes at the site containing gyrA (codons 83 and 87) and parC (codons 80 and 84). PCR products from 47 FQ-resistant strains containing mutations in gyrA and parC were not digested by the restriction enzymes at the site containing the mutation. As for the non-baumannii Acinetobacter strains, although amplification products for gyrA were obtained for 28 strains, no parC amplification product was obtained for any strain. Conclusions: This assay specifically amplified gyrA and parC from A. baumannii and detected A. baumannii gyrA and parC mutations with FQ resistance.

Arbuscular Mycorrhizal Fungal Diversity Associated with Tea Plant (camelia Sinensis) Roots under Inorganic and Organic Fertilization in Acidic Soil in the East Black Sea Region of Turkey

Kazuki Suzuki,Oguz Can Turgay,Muhittin Onur Akca,Ali Ergul,Naoki Harada,Masanori Nonaka 한국토양비료학회 2014 한국토양비료학회 학술발표회 초록집 Vol.2014 No.6

Magnetic Imaging with Coherent X-rays

Motohiro Suzuki,Tetsuya Nakamura,Naoki Awaji,Masakiyo Tsunoda 한국자기학회 2010 한국자기학회 학술연구발표회 논문개요집 Vol.2010 No.12

Real-Time, in Situ Monitoring of the Oxidation of Graphite: Lessons Learned

Morimoto, Naoki,Suzuki, Hideyuki,Takeuchi, Yasuo,Kawaguchi, Shogo,Kunisu, Masahiro,Bielawski, Christopher W.,Nishina, Yuta American Chemical Society 2017 Chemistry of materials Vol.29 No.5

<P>Graphite oxide (GO) and its constituent layers (i.e., graphene oxide) display a broad range of functional groups and, as such, have attracted significant attention for use in numerous applications. GO is commonly prepared using the 'Hummers method' or a variant thereof in which graphite is treated with KMnO4 and various additives in H2SO4. Despite its omnipresence, the underlying chemistry of such oxidation reactions is not well understood and typically affords results that are irreproducible and, in some cases, unsafe. To overcome these limitations, the oxidation of graphite under Hummers-type conditions was monitored over time using in situ X-ray diffraction and in situ X-ray absorption near edge structure analyses with synchrotron radiation. In conjunction with other atomic absorption spectroscopy, UV vis spectroscopy and elemental analysis measurements, the underlying mechanism of the oxidation reaction was elucidated, and the reaction conditions were optimized. Ultimately, the methodology for reproducibly preparing GO on large scales using only graphite, H2SO4 and KMnO4 was developed and successfully adapted for use in continuous flow systems.</P>

Intestinal Microbiota and the Development of Allergy in Infants

( Yoichi Kohno ),( Shuichi Suzuki ),( Eduardo Campos ),( Naoki Shimojo ) 대한천식알레르기학회 2007 천식 및 알레르기 Vol.27 No.4

We analyzed fecal microbiota in Japanese infants with or without allergy at 6 months using a culture technique. Determination of allergy was based on clinical symptoms, signs, and skin prick test. There were no differences in frequencies or counts of 13 genera and yeast-like organisms at 6 months of age between allergic and non-allergic infants. Bifidobacterium was dominant in all infants irrespective of the presence or absence of allergy. We next investigated the composition of fecal Bifidobacterium species in allergic and non-allergic infants using Bifidobacterium species-specific or group- specific primers based on 16S rDNA sequences at 1, 3 and 6 months of age. At 1 month of age, allergic infants had a higher prevalence of B. catenulatum than non-allergic infants (60.0% vs. 6.3%, P<0.01). At 6 months of age, allergic infants had a higher prevalence of B. bifidum than non-allergic infants (70.0% vs. 12.5%, P<0.01). These differences were not related to feeding methods. Finally, we studied the activity of B. bifidum in comparison with B. adolescentis to induce TNF-α and IL-10 from cord blood mononuclear cells. The results suggest B. bifidum has lower activity to induce both cytokines compared to B. adolescentis, suggesting that colonization of lower cytokine producing Bifidobacterium species or strains may be a risk factor for the development of allergy in infancy. (Korean J Asthma Allergy Clin Immunol 2007;27:220-225)

Interleukin-34 cancels anti-tumor immunity by PARP inhibitor

Takayoshi Nakamura,Nabeel Kajihara,Naoki Hama,Takuto Kobayashi,Ryo Otsuka,Nanumi Han,Haruka Wada,Yoshinori Hasegawa,Nao Suzuki,Ken-ichiro Seino 대한부인종양학회 2023 Journal of Gynecologic Oncology Vol.34 No.3

Objective: Breast cancer susceptibility gene 1 (BRCA1)-associated ovarian cancer patients have been treated with A poly (ADP-ribose) polymerase (PARP) inhibitor, extending the progression-free survival; however, they finally acquire therapeutic resistance. Interleukin (IL)-34 has been reported as a poor prognostic factor in several cancers, including ovarian cancer, and it contributes to the therapeutic resistance of chemotherapies. IL-34 may affect the therapeutic effect of PARP inhibitor through the regulation of tumor microenvironment (TME). Methods: In this study, The Cancer Genome Atlas (TCGA) data set was used to evaluate the prognosis of IL-34 and human ovarian serous carcinoma. We also used CRISPR-Cas9 genome editing technology in a mouse model to evaluate the efficacy of PARP inhibitor therapy in the presence or absence of IL-34. Results: We found that IL34 was an independent poor prognostic factor in ovarian serous carcinoma, and its high expression significantly shortens overall survival. Furthermore, in BRCA1-associated ovarian cancer, PARP inhibitor therapy contributes to anti-tumor immunity via the XCR1+ DC-CD8+ T cell axis, however, it is canceled by the presence of IL-34. Conclusion: These results suggest that tumor-derived IL-34 benefits tumors by creating an immunosuppressive TME and conferring PARP inhibitor therapeutic resistance. Thus, we showed the pathological effect of IL-34 and the need for it as a therapeutic target in ovarian cancer.

Reduction of Bladder Capacity Under Anesthesia Following Multiple Recurrences and Repeated Surgeries of Hunner Lesions in Patients With Interstitial Cystitis

Akira Furuta,Yasuyuki Suzuki,Taro Igarashi,Takahiro Kimura,Shin Egawa,Naoki Yoshimura 대한배뇨장애요실금학회 2022 International Neurourology Journal Vol.26 No.1

Purpose: To investigate the influence of multiple recurrences and repeated surgeries of Hunner lesions on bladder capacity under general anesthesia in patients with interstitial cystitis (IC). Methods: We retrospectively reviewed the clinical records of Hunner-type IC (HIC) patients who underwent transurethral fulguration or resection of Hunner lesions combined with hydrodistension by a single surgeon between 2011 and 2020. Recurrence was defined as reappearance of uncontrolled urinary symptoms in association with new Hunner lesions identified by cystoscopy. Recurrent Hunner lesions were then treated by transurethral surgeries. The recurrence-free rate, potential predictive factors of recurrence, and changes in bladder capacity under anesthesia were examined at each surgical procedure. Results: A total of 92 surgeries were performed in 47 HIC patients, 23 (49%) of whom required multiple procedures (range, 1–5 times). The mean recurrence-free time after the first surgery was 21.7 months. The recurrence-free rate was 53% at 24 months, and decreased to 32% at 48 months. There were no significant differences in age, sex, bladder capacity under anesthesia at the first surgery, duration from symptom onset to the first surgery, O’Leary-Sant questionnaire including symptom and problem indexes, visual analogue scale pain score, and the number of comorbidities between the cases with or without recurrence. Bladder capacity under anesthesia was gradually decreased as the number of surgeries was increased, and bladder capacity at the fourth procedure was significantly decreased to 80% of the capacity at the first surgery. Conclusions: These results suggest that multiple recurrences and repeated surgeries of Hunner lesions result in a reduction of bladder capacity under anesthesia in HIC patients although no predictive factors for recurrence of Hunner lesions were detected

A functional neuron maturation device provides convenient application on microelectrode array for neural network measurement

Han Xiaobo,Matsuda Naoki,Ishibashi Yuto,Odawara Aoi,Takahashi Sayuri,Tooi Norie,Kinoshita Koshi,Suzuki Ikuro 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Microelectrode array (MEA) systems are valuable for in vitro assessment of neurotoxicity and drug efficiency. However, several difficulties such as protracted functional maturation and high experimental costs hinder the use of MEA analysis requiring human induced pluripotent stem cells (hiPSCs). Neural network functional parameters are also needed for in vitro to in vivo extrapolation.In the present study, we produced a cost effective nanofiber culture platform, the SCAD device, for long-term culture of hiPSC-derived neurons and primary peripheral neurons. The notable advantage of SCAD device is convenient application on multiple MEA systems for neuron functional analysis.We showed that the SCAD device could promote functional maturation of cultured hiPSC-derived neurons, and neurons responded appropriately to convulsant agents. Furthermore, we successfully analyzed parameters for in vitro to in vivo extrapolation, i.e., low-frequency components and synaptic propagation velocity of the signal, potentially reflecting neural network functions from neurons cultured on SCAD device. Finally, we measured the axonal conduction velocity of peripheral neurons. Conclusions: Neurons cultured on SCAD devices might constitute a reliable in vitro platform to investigate neuron functions, drug efficacy and toxicity, and neuropathological mechanisms by MEA.

Hemilaminectomy for Removal of Extramedullary or Extradural Spinal Cord Tumors: Medium to Long-Term Clinical Outcomes

Toshitaka Naganawa,Kei Miyamoto,Hideo Hosoe,Naoki Suzuki,Katsuji Shimizu 연세대학교의과대학 2011 Yonsei medical journal Vol.52 No.1

Purpose: Laminectomy is generally the treatment of choice for removal of spinal tumors. However, it has been shown that laminectomy may cause instability due to damage of posterior elements of the spinal column, which may induce subsequent kyphosis in the future. Therefore, to reduce the risk of deformity and spinal instability after laminectomy, hemilaminectomy has been used. However, the medium to long-term effects of hemilaminectomy on spinal sagittal alignment is not well understood. The present study was performed to evaluate the clinical outcomes, including spinal sagittal alignment of patients, associated with spinal cord tumors treated by surgical excision using hemilaminectomy. Materials and Methods: Twenty hemilaminectomy operations at our institute for extramedullary or extradural spinal cord tumors in 19 patients were evaluated retrospectively with an average follow-up of 85 months (range, 40-131 months). Neurological condition was evaluated using the improvement ratio of the Japanese Orthopaedic Association Score (JOA score) for cervical, thoracic myelopathy, or back pain, and sagittal alignment by sagittal Cobb angle of the hemilaminectomied area. Results: The mean improvement ratio of neurological results was 56.7% in the cervical spine (p < 0.01, n = 10), 26.3% in the thoracic spine (not significant, n = 5), and 48.6% in the lumbar spine (NS, n = 5). The sagittal Cobb angle was 4.3 ± 18.0° in the preoperative period and 5.4 ± 17.6° at the latest follow-up, indicating no significant deterioration. Conclusion: Hemilaminectomy is useful for extramedullary or extradural spinal cord tumors in providing fair neurological status and restoration of spinal sagittal alignment in medium to long-term follow-up.