Active and reactive power in stochastic resonance for energy harvesting

A power allocation to active and reactive power in stochastic resonance is discussed for energy harvesting from mechanical noise. It is confirmed that active power can be increased at stochastic resonance, in the same way of the relationship between energy and phase at an appropriate setting in resonance.Comment: 3 pages, 4 figure

Oxidation mechanisms of ZRB2-based ultra high temperature ceramic matrix composites

Ultra-high temperature ceramics (UHTCs) are expected as the materials for the nose cones and leading edges for hypersonic and re-entry vehicles. Zirconium diboride (ZrB2) and its composites are a widely studied class of UHTCs. The oxidation of monolithic ZrB2 forms ZrO2 and B2O3. B2O3 acts as a surface protective layer; however, it evaporates above 1200℃. SiC particles are considered effective additives because the SiO2 formed by the oxidation of SiC protects the unreacted region. Simultaneously, excessive pores are formed under the surface in the SiC particle-dispersed ZrB2 matrix (hereafter denoted ZS) composites in a wide temperature range by the preferential oxidation of SiC (active oxidation of SiC) because solid SiO2 is not formed; instead, gaseous SiO forms by active oxidation because of the low oxygen partial pressure relative to that of the surface. The pore-rich porous layer is denoted the “SiC-depleted layer”. The SiC-depleted layer leads to spallation and delamination of the oxidized regions on the surface because strength and stiffness of this layer are quite low. Thus, excessive pore formation in ZS composites should be prevented to improve the oxidation resistance. The objective of this study is to understand oxidation mechanisms of ZrB2-based composites and to propose the way to prevent the formation of SiC-depleted layer in ZS composites. In the present study, we fabricated monolithic ZrB2, ZS, and ZrB2-SiC-ZrC (ZSZ) ternary composites by spark plasma sintering (SPS) technique. In addition, carbon fiber-reinforced ZSZ matrix (C/ZSZ) composites was also fabricated by Si melt infiltration (MI) process. Oxidation resistance of monolithic ZrB2, ZS, ZSZ, and C/ZSZ have specially designed fast heating system in order to characterize oxidation resistance above 2000℃. Please click Additional Files below to see the full abstract

日本におけるAtorella vanhoeffeni(刺胞動物門,鉢虫綱,カンムリクラゲ目)の広範囲な地理的分布

Medusae of a rare, small scyphomedusa, Atorella vanhoeffeni Bigelow, 1909 (Cnidaria, Scyphozoa, Coronatae), were collected and/or photographed at three sites in Japan: Notojima, Ishikawa Prefecture, in the Sea of Japan; Osezaki, Shizuoka Prefecture, on the Pacific coast; and Yonaguni Island, Okinawa Prefecture, in the East China Sea. In Japanese waters this species has been previously reported only from Kakeroma Island, Kagoshima Prefecture. The detailed morphology is described based on a medusa from Yonaguni Island

Mirtazapine exerts astrocyte-mediated dopaminergic neuroprotection

Mirtazapine, a noradrenergic and specific serotonergic antidepressant (NaSSA), is known to activate serotonin (5-HT) 1A receptor. Our recent study demonstrated that stimulation of astrocytic 5-HT1A receptors promoted astrocyte proliferation and upregulated antioxidative property in astrocytes to protect dopaminergic neurons against oxidative stress. Here, we evaluated the neuroprotective effects of mirtazapine against dopaminergic neurodegeneration in models of Parkinson's disease (PD). Mirtazapine administration attenuated the loss of dopaminergic neurons in the substantia nigra and increased the expression of the antioxidative molecule metallothionein (MT) in the striatal astrocytes of 6-hydroxydopamine (6-OHDA)-injected parkinsonian mice via 5-HT1A receptors. Mirtazapine protected dopaminergic neurons against 6-OHDA-induced neurotoxicity in mesencephalic neuron and striatal astrocyte cocultures, but not in enriched neuronal cultures. Mirtazapine-treated neuron-conditioned medium (Mir-NCM) induced astrocyte proliferation and upregulated MT expression via 5-HT1A receptors on astrocytes. Furthermore, treatment with medium from Mir-NCM-treated astrocytes protected dopaminergic neurons against 6-OHDA neurotoxicity, and these effects were attenuated by treatment with a MT-1/2-specific antibody or 5-HT1A antagonist. Our study suggests that mirtazapine could be an effective disease-modifying drug for PD and highlights that astrocytic 5-HT1A receptors may be a novel target for the treatment of PD

A successful rechallenge with cetuximab for a case with metastatic rectal cancer

　A 55-year-old man who had been diagnosed with rectal cancer with multiple liver metastases and lymph node metastases on colonoscopy and computed tomography (CT) was referred to Okayama University Hospital for treatment. Based on the diagnosis of non-curative rectal cancer, we planned to perform systematic chemotherapy after surgical resection. We performed a low anterior resection of a 36×35 mm upper rectal moderately differentiated adenocarcinoma with wil-type KRAS. After the resection, a FOLFIRI regimen with cetuximab was given as the first-line chemotherapy. Although metastatic lesions in the liver showed shrinkage, we decided to switch regimens because of intolerable adverse events. A modified FOLFOX6 regimen with bevacizumab was administered as the second-line treatment. There were no signs of disease progression until eight months later, when positron emission tomography (PET)/CT scans revealed that the new metastatic lesions appeared. As the third-line treatment, an irinotecan with cetuximab regimen was administered, leading to a good response for over 12 months. 　We experienced a successful rechallenge with cetuximab for a case with metastatic rectal cancer. For patients with wild-type KRAS colorectal cancer, rechallenge with cetuximab-based chemotherapy can be an effective therapeutic option