Green cell association for multimedia transmission in cognitive heterogeneous networks

With the introduction of low‐powered pico/femto‐base stations and relay nodes into the macro‐cell, recent heterogeneous networks provide an attractive approach for future wireless communication. Although it may achieve better coverage and higher capacity, several problems remain unsolved before practical deployment. For example, how to select the proper cell from neighbor low‐powered cells and then occupy the radio resource without interference on macro‐users is both important and challenging, especially for rigorous multimedia applications. The traditional cell access algorithms and quality‐control parameters such as delay or throughput no longer suit well in this complex environment. An effective approach should be pursued. In this paper, we investigate this interesting cell association problem and propose a complete green resolution on the basis of thorough discussions about the multimedia transmission under these concerns. Cognitive radio is introduced to share spectrum between macro‐cell and low‐powered cells while securing the transmission of authorized macro‐users. We also bring forth the concept of ‘interference balance’ to better manage the overall interference and energy consumption in the network. Restless bandit model is formulated on the basis of channel state, data rate, interference control, and the carefully chosen intra‐refreshing rate for multimedia traffic. Then the cell association scheme is designed to be efficient and practical because of the simple index property of our model output. Simulation results have proven the performance of our proposed resolution compared with existing algorithms on interference constraint, multimedia distortion, and overall network energy consumption balance. Copyright © 2013 John Wiley & Sons, Ltd.     

工艺参数对马氏体不锈钢激光冲击区表面轮廓的影响

激光功率密度和搭接率对马氏体不锈钢的激光冲击区的表面轮廓有较大影响.激光功率密度从3.79 GW/cm2到7.25 GW/cm2,冲击区塑性变形程度随功率密度增大而增大,当激光功率密度为6.09 GW/cm2时,冲击区塑性变形程度适中,其残余应力平均值达-569.1 MPa.搭接率试验结果表明,搭接率为33%时,可获得较大面积无挤出的激光冲击区,无挤出区域的塑性均匀,变形深度波动幅度在2μm以内,而且此搭接率下冲击区挤出面积较小,分布具有规律,便于再次冲击以降低冲击区的表面波纹度.     

一种自适应红外图像边缘增强算法

针对红外图像边缘模糊和非均匀性噪声强的特点,提出了一种基于加权的自适应红外图像边缘增强方法。该方法不仅增强红外图像边缘,而且改善了传统边缘增强算法对图像噪声放大的缺点,避免了对强边缘的过渡增强导致图像出现过增强现象,改善了图像质量。实验结果表明,该方法具有良好的前景和实用价值。     

Podocyte-Related Mechanisms Underlying Survival Benefit of Long-Term Angiotensin Receptor Blocker

We previously found that short-term treatment (week 8 to 12 after injury) with high-dose angiotensin receptor blocker (ARB) induced the regression of existing glomerulosclerosis in 5/6 nephrectomy rats. We therefore assessed the effects of long-term intervention with ARB vs. nonspecific antihypertensives in this study. Adult rats underwent 5/6 nephrectomy and renal biopsy 8 weeks later. The rats were then divided into three groups with equivalent renal function and glomerular sclerosis and treated with high-dose losartan (ARB), nonspecific antihypertensive triple-therapy (TRX), or left untreated (Control) until week 30. We found that blood pressure, serum creatinine levels, and glomerulosclerosis were lower at sacrifice in ARB and TRX vs. Control. Only ARB reduced proteinuria and maintained the density of WT-1-positive podocytes. Glomerular tufts showed more double-positive cells for CD44, a marker of activated parietal epithelial cells, and synaptopodin after ARB vs. TRX or Control. ARB treatment reduced aldosterone levels. ARB-treated rats had significantly improved survival when compared with TRX or Control. We conclude that both long-term ARB and triple-therapy ameliorate progression, but do not sustain the regression of glomerulosclerosis. ARB resulted in the superior preservation of podocyte integrity and decreased proteinuria and aldosterone, linked to increased survival in the uremic environment.     

Integrated Analysis of Microarray,Small RNA,and Degradome Datasets Uncovers the Role of MicroRNAs in Temperature-Sensitive Genic Male Sterility in Wheat

Temperature-sensitive genic male sterile (TGMS) line Beijing Sterility 366 (BS366) has been utilized in hybrid breeding for a long time, but the molecular mechanism underlying male sterility remains unclear. Expression arrays, small RNA, and degradome sequencing were used in this study to explore the potential role of miRNA in the cold-induced male sterility of BS366. Microspore observation showed defective cell plates in dyads and tetrads and shrunken microspores at the vacuolated stage. Differential regulation of Golgi vesicle transport, phragmoplast formation, sporopollenin biosynthesis, pollen exine formation, and lipid metabolism were observed between cold and control conditions. Pollen development was significantly represented in the 352 antagonistic miRNA-target pairs in the integrated analysis of miRNA and mRNA profiles. The specific cleavage of ARF17 and TIR1 by miR160 and miR393 were found in the cold-treated BS366 degradome, respectively. Thus, the cold-mediated miRNAs impaired cell plate formation through repression of Golgi vesicle transport and phragmoplast formation. The repressed expression of ARF17 and TIR1 impaired pollen exine formation. The results of this study will contribute to our understanding of the roles of miRNAs in male sterility in wheat.     

Mn、Co掺杂SiC薄膜结构与光致发光性能研究

采用射频磁控溅射技术和复合靶材方法制备了掺Mn,掺Co和Co、Mn共掺的SiC薄膜,经高温退火后进行了光致发光(PL)谱的测量,还用X射线衍射(XRD),傅立叶变换红外光谱(FTIR),扫描电镜(SEM)等表征手段分析了薄膜的相结构和表面形貌,并与光致发光的结果进行了对比研究.结果表明,掺Mn、Co使SiC晶格发生畸变,X射线衍射峰强度下降,Si-C吸收谱变宽,Si-C键振动减弱,Si-O基团的振动增强.样品在室温条件下均呈现出强的紫光发射特性,发光峰均位于414nm(3.0eV),认为414nm处的光致发光峰对应于光激发产生的电子从导带底到Si空位浅受主能级之间的辐射跃迁,其强度取决于Si空位的浓度.     

Hematopoietic–Mesenchymal Signals Regulate the Properties of Mesenchymal Stem Cells

It is well known that the properties of hematopoietic stem/progenitor cells (HSCs), such as their self-renewal ability and multipotency, are maintained through interactions with mesenchymal stem/stromal cells (MSCs). MSCs are rare cells that are present in the bone marrow and are useful for clinical applications due to their functional ability. To obtain the necessary number of cells, MSCs must be cultured to expand, but this causes a remarkable decrease in stem cell properties, such as multipotency and proliferation ability. In this study, we show that the c-Mpl signal, which is related to the maintenance of hematopoietic stem cells, has an important effect on the proliferation and differentiation ability of MSCs. Utilizing a co-culture system comprising MSCs and HSCs, it is suggested that signaling from hematopoietic cells to MSCs supports cell proliferation. Interestingly, the enhanced proliferation ability of the HSCs was decreased in c-Mpl knock-out HSCs (c-Mpl-KO). In addition, the MSCs co-cultured with c-Mpl-KO HSCs had reduced MSC marker expression (PDGFRa and Sca-1) compared to the MSCs co-cultured with c-Mpl-wild-type HSCs. These results suggest that a hematopoietic–mesenchymal signal exists, and that the state of the HSCs is important for the stability of MSC properties.     

扫描电镜法研究硅胶填料的孔结构

硅胶作为色谱分离科学中最常使用的柱填料,其孔结构对色谱的分离性能起决定作用,所以研究填料的孔结构具有重要意义.本文通过对硅胶填料进行包埋切片,然后用扫描电镜观察其孔结构,并将此法与BET法、压汞法等传统方法测得的结果进行了比较,结果表明:此法是这些检测手段的必要补充,并且能为色谱工作者研究填料的孔结构提供更加准确、形象、直观的结构信息.     

2mm HM连接器短路失效分析

通过对2mm HM连接器发生安装短路失效分析发现:连接器端子间多余物是引起该短路故障的主要原因。该多余物为连接器端子冲压时因冲裁不彻底而残留的金属屑。卡在连接器端子与塑胶壳体间的金属屑,在PCBA组装压接过程中,刺破PCB阻焊膜,与顶层铜箔相连,造成短路失效。只有严格控制连接器生产工艺,加强质量检验,才能避免连接器安装短路故障的发生。