25(OH)D Is Effective to Repress Human Cholangiocarcinoma Cell Growth through the Conversion of 25(OH)D to 1α,25(OH)2D3

Cholangiocarcinoma (CCA) is a devastating disease without effective treatments. 1α,25(OH)₂D₃, the active form of Vitamin D, has emerged as a new anti-cancer regimen. However, the side effect of hypercalcemia impedes its systemic administration. 25(OH)D is biologically inert and needs hydroxylation by CYP27B1 to form 1α,25(OH)₂D₃, which is originally believed to only take place in kidneys. Recently, the extra-renal expression of CYP27B1 has been identified and in vitro conversion of 25(OH)D to 1α,25(OH)₂D₃ has been found in some cancer cells with CYP27B1 expression. In this study, CYP27B1 expression was demonstrated in CCA cells and human CCA specimens. 25(OH)D effectively represses SNU308 cells growth, which was strengthened or attenuated as CYP27B1 overexpression or knockdown. Lipocalcin-2 (LCN2) was also found to be repressed by 25(OH)D. After treatment with 800 ng/mL 25(OH)D, the intracellular 1α,25(OH)₂D₃ concentration was higher in SNU308 cells with CYP27B1 overexpression than wild type SNU308 cells. In a xenograft animal experiment, 25(OH)D, at a dose of 6 μg/kg or 20 μg/kg, significantly inhibited SNU308 cells’ growth without inducing obvious side effects. Collectively, our results indicated that SNU308 cells were able to convert 25(OH)D to 1α,25(OH)₂D₃ and 25(OH)D CYP27B1 gene therapy could be deemed as a promising therapeutic direction for CCA.     

Low‐latency retransmission control in a wireless communication system for plant instrumentation and control

When wireless communication technology is applied to plant instrumentation and control systems, it is important to ensure real‐time transmission and high reliability of the wireless communication system. However, the wireless communication system is prone to more frequent occurrence of transmission errors than a wired communication system, so that generally retransmission is implemented generically. To reduce retransmission latency, we propose a method of low‐latency retransmission control, which is a data block transmission method with multi‐redundant media access control layer (MAC) headers, to implement a wireless communication system for plant instrumentation and control. We carried out system tests using prototypes with the proposed methods, that is, data block transmission with multi‐redundant MAC headers. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Robust control with pole assignment in a specified region for systems under parameter perturbations; application to a nonlinear system

This paper deals with the problem of determination of feedback gains in order to achieve required performances under linear time invariant perturbations. Based upon the Lagrange multiplier method, the proposed method determines feedback gains that ensure both robust stability and robust performance for a linear uncertain system. It is applied to a nonlinear crane system control design. The nonlinear system is first partitioned into some uncertain linear systems. Then the proposed method is applied to each uncertain linear system. Application is easily demonstrated and, consequently, a nonlinear crane control system can be easily designed. Finally, it is shown in a numerical example that the proposed method is effective.     

Efficiency evaluation of lightning fault inspection in 66‐kV transmission line

A transmission line must be immediately inspected when it is struck by lightning, and damaged parts must be found and changed promptly if the damage is serious. However, such cases are now uncommon owing to the effective design of the lightning protection system now in use. Therefore, it is important to compare data on past lightning events and on transmission lines and to formulate criteria for deciding more precisely in which cases an actual inspection should be carried out. The criteria identified are as follows: (1) the insulator voltage exceeds the critical voltage; (2) the arc current and arc duration exceed the characteristic of insulator breakdown; (3) the number of accident phases is more than 3 ground faults per circuit; (4) the tower foot resistance is 10 ohms or more; (5) the lightning current has a positive characteristic. By using these criteria, the number of lightning fault inspections was reduced by 34%. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 166(2): 15–22, 2009; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20724     

弥散强化合金高温蠕变速度的预测

本文提出了预测弥散强化合金高温蠕变速度的模型。用此模型对第二相粒子分别为热稳定粒子(P)、溶解颗粒(Pd)、溶解并粗化颗粒(PdC)、以及纯Al(M)等4种Al合金的高温蠕变速度ε进行了理论计算。讨论了0.58T_m到0.70T_m(T_m为基体的熔点温度)的温度范围和3.5×10~(-4)E到1.O×10~(-2)E(E为基体的杨氏模量)的应力范围对这些合金状态的高温蠕变速度ε的影响。结果表明,弥散强化是一种有效的高温合金强化方法。     

采用新日铁公司结晶器搅拌技术提高板坯质量

日本工业部门要求钢材生产厂稳定提供高质量板材,为了满足这一要求,板坯表面需要清理.为了减少板坯表面清理率,新日铁公司开发了结晶器搅拌技术,以改善板坯表面质量,本文介绍了这一技术及其效果.     

Focused ion beam fabrication of field-ion microscope specimens from mechanically milled pearlitic steel powder

Sharp needle-like specimens for atom-probe field-ion microscope (APFIM) analysis have been prepared successfully from mechanically milled pearlitic steel powders. Mechanically milled powders were packed in a stainless steel tube with carbonyl steel powders and then consolidated by sheath cold-rolling to obtain a bulk composite. A small square rod was cut out from the bulk and electropolished to a blunt needle. It was then fabricated to a nanometre-sized needle by a focused ion beam technique using an annular gallium ion beam. The tip radius of the specimen was <50 nm, which is suitable for use in APFIM.