Ultrasonic Cleaner using Two Transducers for Ship Hull Cleaning Robot

Fuel consumption of the ship gets worse by barnacles and stains put on its bottom, so that the ship hull should be cleaned regularly. Usual methods such as cleaning by special divers and cleaning after pulling up to the dock are not used frequently due to those high cost and the heavy burden on cleaners. We proposed a cleaning method using underwater vehicle with brushes, however there is a possibility to remove paints on the hull. To improve cleaning performance of the underwater vehicle, the ultrasonic cleaner is developed by using cavitation occurred by sound waves of the acoustic transduces. The cleaner generates sound waves with sound pressure of 0.2MPa or more required to occur cavitation at the point where sound waves from two transducers overlap. In experimental results, the cleaner occurred cavitation enough to make two holes in the aluminum foil located 50mm away from transducers.The 2022 International Conference on Artificial Life and Robotics (ICAROB 2022), January 20-23, 2022, on line, Oita, Japa

Evolution of Nonlinear Acoustics during Creep in ASME Grade 91 Steel Welded Joint

ASME Grade 91 (9Cr-1Mo-MnVNb) has been used for boiler components in ultra-supercritical (USC) thermal power plants at approximately 873 K. The creep life of the welded joints in this steel decreased as a result of Type IV creep damage that forms in the heat-affected zone (HAZ) under long-term use at high temperatures [1]. In this study, we investigated the relationship between microstructural change and the evolutions of two nonlinear acoustic characterizations with electromagnetic acoustic resonance (EMAR) [2] throughout the creep life in the welded joints and the correlation between two nonlinear acoustic characterizations. One was resonant frequency shift [3] and other three-wave mixing [4, 5]. EMAR was a combination of the resonant acoustic technique with a non-contact electromagnetic acoustic transducer (EMAT) [2]. We used a bulk-wave EMAT, which transmits and receives shear wave propagating in thickness direction of a plate specimen. Creep tests of thick welded joints specimens were interrupted at several time steps at 873 K and 90 MPa. Two nonlinear acoustic parameters and ultrasonic attenuation decreased from the start to 20% of creep life. They gradually increased from 50% of creep life to rupture. We interpreted these phenomena in terms of dislocation recovery, recrystallization, and restructuring related to the initiation and growth of creep void, with support from the SEM and TEM observation. This noncontact resonance-EMAT measurement can monitor the evolution of nonlinear acoustics throughout the creep life and has a potential to assess the Type IV creep damage advance and to predict the creep life of high Cr ferritic heat resisting steels

Impaired CD4 + T-cell proliferation and effector function correlates with repressive histone methylation events in a mouse model of severe sepsis

Immunosuppression following severe sepsis remains a significant human health concern, as long-term morbidity and mortality rates of patients who have recovered from life-threatening septic shock remain poor. Mouse models of severe sepsis indicate this immunosuppression may be partly due to alterations in myeloid cell function; however, the effect of severe sepsis on subsequent CD4 + T-cell responses remains unclear. In the present study, CD4 + T cells from mice subjected to an experimental model of severe sepsis (cecal ligation and puncture (CLP)) were analyzed in vitro . CD4 + CD62L + T cells from CLP mice exhibited reduced proliferative capacity and altered gene expression. Additionally, CD4 + CD62L + T cells from CLP mice exhibit dysregulated cytokine production after in vitro skewing with exogenous cytokines, indicating a decreased capability of these cells to commit to either the T H 1 or T H 2 lineage. Repressive histone methylation marks were also evident at promoter regions for the T H 1 cytokine IFN-Γ and the T H 2 transcription factor GATA-3 in naÏve CD4 + T cells from CLP mice. These results provide evidence that CD4 + T-cell subsets from post-septic mice exhibit defects in activation and effector function, possibly due to chromatin remodeling proximal to genes involved in cytokine production or gene transcription.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71365/1/998_ftp.pd

Experimental cerebral malaria progresses independently of the Nlrp3 inflammasome

Cerebral malaria is the most severe complication of Plasmodium falciparum infection in humans and the pathogenesis is still unclear. Using the P. berghei ANKA infection model of mice, we investigated a potential involvement of Nlrp3 and the inflammasome in the pathogenesis of cerebral malaria. Nlrp3 mRNA expression was upregulated in brain endothelial cells after exposure to P. berghei ANKA. Although Β-hematin, a synthetic compound of the parasites heme polymer hemozoin, induced the release of IL-1Β in macrophages through Nlrp3, we did not obtain evidence for a role of IL-1Β in vivo . Nlrp3 knock-out mice displayed a delayed onset of cerebral malaria; however, mice deficient in caspase-1, the adaptor protein ASC or the IL-1 receptor succumbed as WT mice. These results indicate that the role of Nlrp3 in experimental cerebral malaria is independent of the inflammasome and the IL-1 receptor pathway.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/69193/1/764_ftp.pd

Insight into the origin of carbon corrosion in positive electrodes of supercapacitors

While activated carbons are used as electrode materials in commercial supercapacitors, they are not stable under high voltage operation especially at a positive-electrode side, and this limits the working voltage of supercapacitors to about 2.8 V in organic electrolytes. Thus, revealing the specific carbon chemical structures causing the corrosion is of great significance to come up with ideas of avoiding the corrosion reactions and eventually to achieve high energy density by expanding the working voltage. In this work, a variety of carbon materials are analyzed with many characterization techniques such as X-ray diffraction, Raman spectroscopy, N2 adsorption, magnetic susceptibility measurement, and temperature programmed desorption up to 1800 °C, to find out the origin of corrosion reactions in an organic electrolyte. While carbon crystallinity and porosity are not directly related to the positive-electrode corrosion, a good correlation is found between the corrosion charge and the number of carbon edge sites terminated by H and oxygen-functional groups which are decomposed and release CO. It is thus concluded that the H-terminated edge sites, phenol, ether and carbonyl groups are electroactive sites for the carbon materials used in the positive electrode of supercapacitors.This work was supported by JSPS KAKENHI (grant no. 15H01999 and 17H01042); the Dynamic Alliance for Open Innovation Bridging Human, Environment, and Materials program; and the Network Joint Research Centre for Materials and Devices. R. T. acknowledges the China Scholarship Council for the financial support. MINECO and FEDER (CTQ2015-66080-R MINECO/FEDER) are acknowledged for financial support

Toll-like receptor 9 mediates innate immune activation by the malaria pigment hemozoin

Malaria parasites within red blood cells digest host hemoglobin into a hydrophobic heme polymer, known as hemozoin (HZ), which is subsequently released into the blood stream and then captured by and concentrated in the reticulo-endothelial system. Accumulating evidence suggests that HZ is immunologically active, but the molecular mechanism(s) through which HZ modulates the innate immune system has not been elucidated. This work demonstrates that HZ purified from Plasmodium falciparum is a novel non-DNA ligand for Toll-like receptor (TLR)9. HZ activated innate immune responses in vivo and in vitro, resulting in the production of cytokines, chemokines, and up-regulation of costimulatory molecules. Such responses were severely impaired in TLR9−/− and myeloid differentiation factor 88 (MyD88)−/−, but not in TLR2, TLR4, TLR7, or Toll/interleukin 1 receptor domain–containing adaptor-inducing interferon β−/− mice. Synthetic HZ, which is free of the other contaminants, also activated innate immune responses in vivo in a TLR9-dependent manner. Chloroquine (CQ), an antimalarial drug, abrogated HZ-induced cytokine production. These data suggest that TLR9-mediated, MyD88-dependent, and CQ-sensitive innate immune activation by HZ may play an important role in malaria parasite–host interactions

Effect of KAATSU training on thigh muscle size and safety for a patient with knee meniscectomy over 3 years

[Objective] It is well known that knee meniscectomy is one of the major knee surgeries, which induces thigh muscle atrophy. However, it is unclear whether thigh muscle size after knee meniscectomy can be improved with KAATSU training. We examined effect of KAATSU training on thigh muscle size and safety for a patient with knee meniscectomy.[Methods] The patient was a 57-year-old woman (standing height 159 cm and body weight 52 kg). The KAATSU training composed of 7 types of resistance exercise and one type of cycling exercise was provided for a total of 125 sessions over approximately 3 years. Transverse scans were carried out for mid-thigh length. Thigh muscle cross-sectional area (CSA) in affected-leg and unaffected-leg was measured by the CT scan before, 63 weeks, and 152 weeks after the training.[Results] Thigh muscle CSA was highly increased for affected-leg, and the attained level was exactly similar for both legs after the 152 weeks training period.[Conclusion] The long-term KAATSU exercises were a highly safe and effective training method for a patient with knee meniscectomy

Serologic Markers in Relation to Parasite Exposure History Help to Estimate Transmission Dynamics of Plasmodium vivax

Plasmodium vivax infection has been gaining attention because of its re-emergence in several parts of the world. Southeastern Turkey is one of the places in which persistent focal malaria caused exclusively by P. vivax parasites occurs. Although control and elimination studies have been underway for many years, no detailed study has been conducted to understand the mechanisms underlying the ineffective control of malaria in this region. Here, for the first time, using serologic markers we try to extract as much information as possible in this region to get a glimpse of P. vivax transmission. We conducted a sero-immunological study, evaluating antibody responses of individuals living in Sanliurfa to four different P. vivax antigens; three blood-stage antigens (PvMSP119, PvAMA1-ecto, and PvSERA4) and one pre-erythrocytic stage antigen (PvCSP). The results suggest that a prior history of malaria infection and age can be determining factors for the levels and sustainability of naturally acquired antibodies. Significantly higher antibody responses to all the studied antigens were observed in blood smear-negative individuals with a prior history of malaria infection. Moreover, these individuals were significantly older than blood smear-negative individuals with no prior history of infection. These data from an area of sole P. vivax-endemic region may have important implications for the global malaria control/elimination programs and vaccine design