Hydraulic Characteristics of Perforated Hose for Spray Irrigation and Mathematical Model for Calculating Spray Distribution

散水灌漑用多孔ホースの水理特性を調べるために実験を行った. このホースはポリエチレン製であるが,流水中のゴミによる目詰り対策用の特殊フィルタが取り付けられている. まず,ホース細孔の流量係数をc,その細孔の断面積をaとして,係数caを圧力の一次式で表した. また,横断方向の散水分布をガンマ分布で近似した. その形状母数は一定値としたが,尺度母数は圧力の関数として表した. 次に,ホース内の流れを水理学的に定式化し,HAZEN-WILLIAMS平均流速公式の係数CHの値をシミュレーション的に調べてCH=60を得た. また流量･水圧および2次元的散水分布を計算できる水理モデルを提示するとともに,これが実際の現象をよく再現できることを示した

Bragg x-ray ptychography of a silicon crystal: Visualization of the dislocation strain field and the production of a vortex beam

We experimentally demonstrate the visualization of nanoscale dislocation strain fields in a thick silicon single crystal by a coherent diffraction imaging technique called Bragg x-ray ptychography. We also propose that the x-ray microbeam carrying orbital angular momentum is selectively produced by coherent Bragg diffraction from dislocation singularities in crystals. This work not only provides us with a tool for characterizing dislocation strain fields buried within extended crystals but also opens up new scientific opportunities in femtosecond spectroscopy using x-ray free-electron lasers.Yukio Takahashi, Akihiro Suzuki, Shin Furutaku, Kazuto Yamauchi, Yoshiki Kohmura, and Tetsuya Ishikawa, Phys. Rev. B 87, 121201, 2013

High-resolution and high-sensitivity phase-contrast imaging by focused hard x-ray ptychography with a spatial filter

We demonstrate high-resolution and high-sensitivity x-ray phase-contrast imaging of a weakly scattering extended object by scanning coherent diffractive imaging, i.e., ptychography, using a focused x-ray beam with a spatial filter. We develop the x-ray illumination optics installed with the spatial filter to collect coherent diffraction patterns with a high signal-to-noise ratio. We quantitatively visualize the object with a slight phase shift ([formula omitted]) at spatial resolution better than 17 nm in a field of view larger than [formula omitted]. The present coherent method has a marked potential for high-resolution and wide-field-of-view observation of weakly scattering objects such as biological soft tissues.Yukio Takahashi, Akihiro Suzuki, Shin Furutaku, Kazuto Yamauchi, Yoshiki Kohmura, and Tetsuya Ishikawa, "High-resolution and high-sensitivity phase-contrast imaging by focused hard x-ray ptychography with a spatial filter", Appl. Phys. Lett. 102, 094102 (2013) https://doi.org/10.1063/1.4794063

High-resolution multislice X-ray ptychography of extended thick objects

We report the first demonstration of hard x-ray ptychography using a multislice approach, which can solve the problem of the limited spatial resolution under the projection approximation. We measured ptychographic diffraction patterns of a two-layered object with a 105 μm gap using 7 keV focused coherent x rays. We successfully reconstructed the phase map of each layer at ∼50 nm resolution using a multislice approach, while the resolution was worse than ∼192 nm under the projection approximation. The present method has the potential to enable the three-dimensional high-resolution observation of extended thick specimens in materials science and biology.Akihiro Suzuki, Shin Furutaku, Kei Shimomura, Kazuto Yamauchi, Yoshiki Kohmura, Tetsuya Ishikawa, and Yukio Takahashi, Phys. Rev. Lett. 112, 053903, 2014

Development of a mouse iron overload-induced liver injury model and evaluation of the beneficial effects of placenta extract on iron metabolism

Hepatic iron deposition is seen in cases of chronic hepatitis and cirrhosis, and is a hallmark of a poorer prognosis. Iron deposition is also found in non-alcoholic steatohepatitis (NASH) patients. We have now developed a mouse model of NASH with hepatic iron deposition by combining a methione- and choline-deficient (MCD) diet with an iron-overload diet. Using this model, we evaluated the effects of human placenta extract (HPE), which has been shown to ameliorate the pathology of NASH. Four-week-old male C57BL/6 mice were fed the MCD diet with 2% iron for 12 weeks. In liver sections, iron deposition was first detected around the portal vein after 1 week. From there it spread throughout the parenchyma. Biliary iron concentrations were continuously elevated throughout the entire 12-week diet. As a compensatory response, the diet caused elevation of serum hepcidin, which accelerates excretion of iron from the body. Accumulation of F4/80-positive macrophages was detected within the sinusoids from the first week onward, and real-time PCR analysis revealed elevated hepatic expression of genes related inflammation and oxidative stress. In the model mice, HPE treatment led to a marked reduction of hepatic iron deposition with a corresponding increase in biliary iron excretion. Macrophage accumulation was much reduced by HPE treatment, as was the serum oxidation-reduction potential, an index of oxidative stress. These data indicate that by suppressing inflammation, oxidative stress and iron deposition, and enhancing iron excretion, HPE effectively ameliorates iron overload-induced liver injury. HPE administration may thus be an effective strategy for treating NASH.ArticleHeliyon 5(5) : e01637-(2019)journal articl

Placental extract suppresses cardiac hypertrophy and fibrosis in an angiotensin II-induced cachexia model in mice

Cachexia is an intractable metabolic disorder that causes extreme weight loss. It is a symptom of many chronic diseases, including cancer, liver failure, congestive heart failure and chronic kidney disease, and there is as yet no effective treatment. While the mechanisms underlying cachexia are complex, it is often accompanied by elevated angiotensin II (Ang II). Human placental extract (HPE) is a source of numerous biologically active molecules and has been used clinically to treat chronic hepatitis, liver cirrhosis and other chronic diseases. Here, we investigated the effects of HPE in an Ang II-induced cachexia model in mice. HPE treatment preserved both fat mass and lean body mass and suppressed weight loss in the cachexia model, though food intake was unaffected. Ang II infusion also caused cardiac hypertrophy and fibrosis. HPE suppressed these effects as well as Ang II-induced cardiac expression of genes related to heart failure and cardiac remodeling. HPE also reversed Ang II-induced downregulation of mitochondria-related molecules and suppressed cardiac inflammation and oxidative stress. HPE administration may thus be an effective approach to the treatment of cachexia, cardiac hypertrophy and fibrosis.ArticleHeliyon 5(10) : e02655-(2019)journal articl