Anticancer activity of flavonoids accompanied by redox state modulation and the potential for a chemotherapeutic strategy

Since researchers began studying the mechanism of flavonoids’ anticancer activity, little attention has been focused on the modulation of redox state in cells as a potential chemotherapeutic strategy. However, recent studies have begun identifying that the anticancer effect of flavonoids occurs both in their antioxidative activity which scavenges ROS and their prooxidative activity which generates ROS. Against this backdrop, this study attempts to achieve a comprehensive analysis of the individual and separate study findings regarding flavonoids’ modulation of redox state in cancer cells. It focuses on the mechanism behind the anticancer effect, and mostly on the modulation of redox potential by flavonoids such as quercetin, hesperetin, apigenin, genistein, epigallocatechin-3-gallate (EGCG), luteolin and kaempferol in both in vitro and animal models. In addition, the clinical applications of and bioavailability of flavonoids were reviewed to help build a treatment strategy based on flavonoids’ prooxidative potential.     

Enhanced transduction coefficient in piezoelectric PZT ceramics by mixing powders calcined at different temperatures

Large transduction coefficient ($d_{33}\times g_{33}$) is difficult to obtain in piezoelectric ceramics because these two parameters show opposite trends with compositional modifications. Herein, the Pb(Zr_0.53Ti_0.47)O₃ ceramic powders were calcinated under different temperatures (A:830 °C, B:860 °C, and C:890 °C), and then mixed together according to different weight ratios (1A:1B:1C, 1A:2B:1C, 1A:2B:3C and 3A:2B:1C) for ceramics preparation. Both d₃₃ and g₃₃ are improved successfully, and the transduction coefficient with the weight ratio of 1A:2B:3C reaches up to 17,500 × 10⁻¹⁵ m²/N, which is 60 % higher than that with the powders calcinated under 830 °C, and at least twice those of commercial PZT-4, PZT-5A and PZT-8 ceramics. The improved transduction coefficient is owing to the enhanced piezoelectric constant and spontaneous polarization resulted from the increased grain size, relative density and the fraction of tetragonal phase. These results indicate that this is a simple but effective way to tailor the transduction coefficient in piezoelectric ceramics.     

基于CVSD编码的无线语音系统方案的设计

简要介绍了连续可变斜率增量(CVSD)调制的原理。与目前应用较为广泛的其它语音编码方式相比较,CVSD拥有更优的数字特性。着重介绍了由CML公司研制开发的基于CVSD的语音编码芯片———CMX649的特点及相关的应用方式。CMX649能够成功地应用在广泛的语音编码系统中,尤其适合无线语音系统应用。在此基础上,给出了一种实用性很强的低成本、低功耗无线语音系统的设计与应用方案。该方案可提供清晰可靠的语音传输,可广泛应用于农村地区,具有广阔的市场空间。     

浅析医药包装

随着市场经济的深入，医药包装正成为我国经济发展的朝阳产业，文中意在介绍先进的医药包装材料。分析其应用情况及发展趋势和动态。     

一种新型注入剖面组合测井仪及其应用

为了提高注入剖面测井的准确性，研制了一种新型注入剖面组合测井仪。该仪器由流量处理单元、伽马处理单元、井温处理单元、磁性定位处理单元、调制式传输、电源电路六部分组成。一次下井可同时测取流量、伽马、井温、磁性定位四组参数。具有测取资料精度高、单芯电缆传输、流量可单点测量也可连续测量以厦现场监测和维修方便等特点。     

基于服务器端会话追踪的Web查询服务的研究

在探讨了Web查询服务的典型模型后,论文阐述了服务器端会话追踪机制的实现方式,设计了基于服务器端会话追踪的Web查询服务的典型解决方案。该设计方案可以较为安全地保存和维护客户的上下文信息,可靠地跟踪用户查询所处的状态,有效地实现有状态的Web查询服务。     

BOC调制技术研究

伽利略卫星导航系统是欧洲自主的、独立的全球多模式卫星定位导航系统，提供高精度、高可靠性的定位服务，同时它实现完全非军方控制、管理。伽利略系统采用BOC调制方式。现介绍BOC调制的性质及和BPSK调制方式相比较的优点。     

复合材料层合曲梁分层问题的解析解法

根据叠加原理将含有分层的复合材料层合曲梁在横向载荷作用下的受力状态分解为在面受力状态与出面受力状态,再将出面受力状态分解为无分层曲梁受横向载荷状态与含分层曲梁承受附加剪切载荷状态。将分层问题归结为在附加剪切载荷状态中,层合梁附加位移与附加应力的分析,并据此建立了一个简单的力学模型。最后得到了由分层引起的附加位移与应力的解析解答,并用能量释放率方法确定了应力强度因子。     

Sequential Spectrum Analysis of the Sideband Components of Digital Amplitude-Modulated Signals

It is shown that, for the spectrum analysis of digital quasi-periodic signals, one must use a procedure based on approximating the sequence of data readouts by a first-order trigonometric polynomial with a varying frequency of its harmonic functions.     

基于C6711处理器cdma2000 1X系统前向信道信号的处理

在cdma20001x前向信道中,要对一段信号进行传送,一般选用QPSK调制,因为QPSK调制比QAM更适合噪音环境。采用TI6000系列的TMS320C6711芯片处理前向信道信号,可以对复杂性和实时性较高的信号做采集、量化、编码、调制等实时处理,主要功能通过软件编程实现,从而使系统具有结构灵活、可靠性高、可扩展等优点。