GPU-acceleration for Moving Particle Semi-Implicit method

The MPS (Moving Particle Semi-implicit) method has been proven useful in computation free-surface hydrodynamic flows. Despite its applicability, one of its drawbacks in practical application is the high computational load. On the other hand, Graphics Processing Unit (GPU), which was originally developed for acceleration of computer graphics, now provides unprecedented capability for scientific computations. The main objective of this study is to develop a GPU-accelerated MPS code using CUDA (Compute Unified Device Architecture) language. Several techniques have been shown to optimize calculations in CUDA. In order to promote the acceleration by GPU, particular attentions are given to both the search of neighboring particles and the iterative solution of simultaneous linear equations in the Poisson Pressure Equation. In this paper, 2-dimensional calculations of elliptical drop evolution and dam break flow have been carried out by the GPU-accelerated MPS method, and the accuracy and performance of GPU-based code are investigated by comparing the results with those by CPU. It is shown that results of GPU-based calculations can be obtained much faster with the same reliability as the CPU-based ones

Latent pH-responsive ratiometric fluorescent cluster based on self-assembled photoactivated SNARF derivatives

We have developed a self-assembled fluorescent cluster comprising a seminaphthorhodafluor (SNARF) derivative protected by a photoremovable o-nitrobenzyl group. Prior to UV irradiation, a colorless and nonfluorescent cluster was spontaneously assembled in aqueous solution. After UV irradiation, the self-assembled cluster remained intact and showed a large enhancement in pH-responsive fluorescence. The unique pH responsive fluorescent cluster could be used as a dual-emissive ratiometric fluorescent pH probe not only in the test tube but also in HeLa cell cultures

テイサンソ ヒョウテキ ヤクザイ ノ メディシナル ブリコラージュ ト ジセダイ イヤクヒン ボロン トレースドラッグ ノ ソウセイ

Hypoxia is now considered a fundamentally important characteristic of the tumor microenvironment. A discovery of the hypoxia inducible factor（HIF）has led to a rapidly increasing understanding of the molecular mechanisms involved in tumor hypoxia. This in turn has led to the current extensive interest in the signal molecules related to tumor hypoxia as potential molecular targets for cancer therapeutics. In this paper we give a medicinal bricolage overview of recent advances in hypoxia-targeting drugs research. These hypoxia-targeting drugs include antiangiogenic- and sugar-hybrid-hypoxic cell radiosensitizers and hypoxic cytotoxins, hypoxia-targeting boron neutron capture therapy（BNCT）drugs. The evaluation of ADME-tox and pharmacokinetic properties of drugs are extremely important and essential in their discovery process and their lifetime. Traditionally, as well known traceable drugs, their radiolabeled compounds have been studied for their purposes. However, there are some inherent problems such as their half-life and regulation of experimental facilities. For the purpose of overcoming these problems and creating drugs with functions required for systems biology or emerging physiology, we designed, as a traceable nextgeneration drug model, wholly innovative drugs named“boron tracedrug,”their architecture of which were embedded boron atom in their scaffold or skeleton. These boron tracedrugs could be detected whenever and wherever you need to access in their lifetime. We called them“honnête homme”drugs. Also utilizing this specific property of boron tracedrugs, we suggested the neutron dynamic therapy（NDT）

Cyclooxygenase Regulates Angiogenesis Induced by Colon Cancer Cells

AbstractTo explore the role of cyclooxygenase (COX) in endothelial cell migration and angiogenesis, we have used two in vitro model systems involving coculture of endothelial cells with colon carcinoma cells. COX-2-overexpressing cells produce prostaglandins, proangiogenic factors, and stimulate both endothelial migration and tube formation, while control cells have little activity. The effect is inhibited by antibodies to combinations of angiogenic factors, by NS-398 (a selective COX-2 inhibitor), and by aspirin. NS-398 does not inhibit production of angiogenic factors or angiogenesis induced by COX-2-negative cells. Treatment of endothelial cells with aspirin or a COX-1 antisense oligonucleotide inhibits COX-1 activity/expression and suppresses tube formation. Cyclooxygenase regulates colon carcinoma-induced angiogenesis by two mechanisms: COX-2 can modulate production of angiogenic factors by colon cancer cells, while COX-1 regulates angiogenesis in endothelial cells

ジェネティック制御下にある発育鶏卵を用いた工学的in vivo 薬剤評価系の開発

The drug discovery research of clinical-use antioxidants, which may control various vascular disorders caused by the oxidative stress, is extremely important. We present the development of an in vivo evaluation system of antioxidants for their vascular protective activities using the chick embryonic chorioallantoic membrane (CAM). In the case of 12-days chick embryos, the topical administration of 2,2'-azobis(2-methylpropionamidine) dihydrochloride (AAPH) induced their vascular injuries against the CAM veins and venous capillaries but without substantial fatal damage. Artepillin C, a potent natural antioxidant, did not show the chick embryo’s venous injury, and pre-treatment with artepillin C would tend to protect the CAM veins injuries induced by the post-administration of AAPH. These results suggest that artepillin C might be able to protect the AAPH-induced vascular injury in in vivo. In conclusion, we showed the possibility of in vivo evaluation system of antioxidants for their vascular protective activities using the chick embryo

Estimation of annual layer thickness from stratigraphical analysis of Dome Fuji deep ice core

Dating of ice cores is of important but is difficult for an ice core where there is low snow accumulation, and also for the deep part because seasonal chemical and isotopic signals are not easily preserved due to vapor migration after snow deposition and molecular diffusion in the deep part of ice sheet. In this paper, an attempt to reveal annual layer thickness is conducted on the basis of precise number density measurement of air bubbles and air hydrates. The annual layer thickness from air bubbles and hydrates agrees well with a calculated value within 10-15% at all depths of the 2500 m deep core. The obtained thickness in the interglacial period according to Eemian period in the Greenland ice core was half of the calculated value

改良型pＨプロ－ブによる細胞内pHの定量的な計測方法の開発

SNARF is one of the most commonly used pH indicators for biological applications, owing to its unique fluorescent characteristics. For intracellular applications, esterase-substrate derivatives of SNARF, such as acetate or acetoxymethyl esters, have been employed previously as a generally accepted strategy to increase cell permeability. Unfortunately such cell-permeable SNARF derivatives retain significant fluorescence in aqueous solution, a property which results in a low signal-to-noise ratio. This in turn can lead to incorrect intracellullar pH measurements. Here we describe UTX-40, a newly designed SNARF derivative that successfully addresses these problems. In aqueous solution, UTX-40 is devoid of fluorescence before ester hydrolysis because it exists in aqueous environment as nano-scaled aggregates. As UTX-40 is converted into SNARF by enzymatic hydrolysis inside the cell, the aggregates become diffused and monomeric SNARF displays its characteristic fluorescent properties. The results of our studies reported in this communication demonstrate clearly the benefits of UTX-40 as an intracellular pH indicator. Since intracellular localized fluorescence was observed without cell-washing, the efficient uptake of intracellular fluorescence was confirmed. In addition, the actual intracellular pH and changes in intracellular pH caused by drug addition were monitored. The low background noise produced by UTX-40 is a property of this new pH probe that should be particularly advantageous for in vivo usage because, for this application, it is difficult to wash out the redundant probe