Col4a3-/- Mice on Balb/C Background Have Less Severe Cardiorespiratory Phenotype and SGLT2 Over-Expression Compared to 129x1/SvJ and C57Bl/6 Backgrounds

Alport syndrome (AS) is a hereditary renal disorder with no etiological therapy. In the preclinical Col4a3^-/- model of AS, disease progression and severity vary depending on mouse strain. The sodium-glucose cotransporter 2 (SGLT2) is emerging as an attractive therapeutic target in cardiac/renal pathologies, but its application to AS remains untested. This study investigates cardiorespiratory function and SGLT2 renal expression in Col4a3^-/- mice from three different genetic backgrounds, 129x1/SvJ, C57Bl/6 and Balb/C. male Col4a3^-/- 129x1/SvJ mice displayed alterations consistent with heart failure with preserved ejection fraction (HFpEF). Female, but not male, C57Bl/6 and Balb/C Col4a3^-/- mice exhibited mild changes in systolic and diastolic function of the heart by echocardiography. Male C57Bl/6 Col4a3^-/- mice presented systolic dysfunction by invasive hemodynamic analysis. All strains except Balb/C males demonstrated alterations in respiratory function. SGLT2 expression was significantly increased in AS compared to WT mice from all strains. However, cardiorespiratory abnormalities and SGLT2 over-expression were significantly less in AS Balb/C mice compared to the other two strains. Systolic blood pressure was significantly elevated only in mutant 129x1/SvJ mice. The results provide further evidence for strain-dependent cardiorespiratory and hypertensive phenotype variations in mouse AS models, corroborated by renal SGLT2 expression, and support ongoing initiatives to develop SGLT2 inhibitors for the treatment of AS.     

Thematic labelling from hyperspectral remotely sensed imagery: trade-offs in image properties

The effect of spatial, spectral and noise degradations on the accuracy of two highly contrasting thematic labelling scenarios was investigated. The study used hyperspectral imagery of a site near Falmouth, UK, to assess the effect of the data degradations on the accuracy of supervised classification when the H-resolution scene model was applicable and on labelling when an L-resolution scene model was applicable and no ground data were available. In both scenarios, the spatial, spectral and noise degradations affected the accuracy of labelling. However, over the range of degradations investigated, the noise content of the data was consistently noted to be a major variable affecting the accuracy of labelling.     

The importance of choosing attractors for optimizing chaotic communications

In this brief, we consider methods to improve the performance of chaotic communication schemes. We study a system using a receiver which explicitly includes the presence of noise in the channel. We show how the choice of chaotic dynamical system generating the transmitted signal is crucial. We observe a large variation in bit error rate performance of the system as parameters in the maps are changed, and we propose a simple explanation for this variation.     

Helical-core ytterbium-doped fibre laser

An Yb-doped fibre laser with a helical core trajectory in the cladding material has been demonstrated for the first time. The laser yields 350 mW of linearly-polarised, single-spatial-mode output at 1047 nm from a multimode core of diameter, 26 /spl mu/m, and numerical aperture, 0.14, when core-pumped by an Yb:YAG laser at 1030 nm.     

应用于暂时粘结、基片保护和MOEMS封装的新型材料

随着微电子制造商持续缩小晶体管基极和其他元件的尺寸,集成电路的密度不断增大,电路连接工艺中开始使用低k介电质和铜导电体。为了进一步提高电路整体性能与射电频率性能、缩小体积、降低电源损耗、提高散热效率,承载电路的基片的厚度正在持续变薄。常规的工艺已经无法加工先进的超薄基片。为了解决这个工艺中的难题,BrewerScience利用自己先进的材料、工艺、机械设备的研究开发水平,正在开发一套崭新的超薄基片的加工操作流程。介绍用于将超薄基片暂时粘结到另一载体的系列材料和流程,完成加工以后,基片和载体可以很容易地分离。另外,对用于保护基片的新型涂料也进行了介绍。在对基片进行薄化和切割的时候,这种涂料可以对基片提供有效的保护。最后,介绍了高透明高折射材料,这些材料用在高亮度发光二极管(HB-LED)和微光电机械系统(MOEMS)中,可以降低由封装引起的光损耗。     

Mechanisms of Sn Hillock Growth in Vacuum by In Situ Nanoindentation in a Scanning Electron Microscope (SEM)

Nanoindentation is an excellent technique to quantitatively probe the Sn film surface and to introduce controlled compressive stresses. In this work, we have conducted a long-term study of whisker growth in Sn films plated on Cu. In situ indentations were conducted in a scanning electron microscope under vacuum, to elucidate the effect of whiskering without significant oxidation. The evolution of whisker growth up to 1500 h was studied. Measurements of whisker height and width were used to determine the relationship between nodule volume and time. Extensive nodule growth was observed at indentations. Competing mass flow between indentations was observed, with some indentations exhibiting extensive growth, while the growth of others arrested within 100 h. It can be postulated that, when stresses are relieved slowly, hillock heights grow nearly linearly over time. When stress is relieved quickly, a sigmoidal-type curve (arresting growth) is predicted.     

High performance AlyGa1−yAs-GaAs-lrxGa1−xAs quantum well lasers defined by silicon-oxygen impurity-induced layer disordering

In these experiments impurity-induced layer disordering (IILD) utilizing chemical reduction of SiO₂ by Al (from Al_0.8Ga_0.2As) is employed to generate Si and O to effect layer disordering. The SiO₂-Al_0.8Ga_0.2As reaction is studied with respect to annealing ambient. By controlling the extent of disordering via As₄ overpressure, closely spaced (∼1μm) Si-O IILD buried heterostructure lasers can be optically coupled or uncoupled. Direct observation of O incorporation into the buried layers is shown using secondary ion mass spectroscopy (SIMS). The thermal stability of separate-confinement Al_yGa_1−yAs-GaAs-In_xGa_1−xAs quantum well heterostructure (QWH) laser crystals is investigated using SIMS, transmission electron microscopy (TEM), and photoluminescence (PL) measurements. The data show that the thermal stability of a strained-layer In_0.1Ga_0.9As quantum well (QW) is strongly dependent upon: (1) the layer thickness and heterointerfaces of the Al_yGa_1−yAs-GaAs waveguide layers located directly above and below the QW, (2) the type of surface encapsulant employed, and (3) the annealing ambient. Narrow single-stripe (<2μm) lasers fabricated via Si-O diffusion and layer disordering exhibit low threshold currents (I_th ∼ 4 mA) and differential quantum efficiencies,η, of 22% per facet under continuous (cw) room-temperature operation.     

消费电子主导电源管理开发

追求无止境,这不单是现代人对工作的要求,也是摩登时代时尚人士生活的座右铭.消费者的期望就是商家开发新品的风向标,于是融合多种功能的消费类电子产品层出不穷,而纷繁复杂的电源管理犹如一柄达摩克利斯之剑悬挂在设计工程师的头上.AnalogicTech致力于研发电源管理芯片及其解决方案,将在本刊连续发布其专注于电源方面的见解,有望为众多工程师拨开迷雾,把握电源市场的潮流.