2,701 research outputs found

    Fluorescent sensors for biological applications.

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    Fluorescence is one of the most important analytical methods used in biological studies. In the past decade or two, instrumentation in this field has greatly advanced, and now it is possible to detect single photons or fluorescent molecules [1,2], or break the Abbe diffraction limit to distinguish two points spaced less than 50 nm apart [3]. Concurrently, the development of improved fluorescent probes, which can be coupled with state-of-the-art instruments, has been equally important. This special issue on "fluorescent biosensors" in Sensors reports recent results from eight research groups in the field of sensor development. It includes three review articles, and six research articles reporting original results. [...]

    Genetically encoded fluorescent redox probes.

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    Redox processes are involved in almost every cell of the body as a consequence of aerobic life. In the past decades, redox biology has been increasingly recognized as one of the key themes in cell signaling. The progress has been accelerated by development of fluorescent probes that can monitor redox conditions and dynamics in cells and cell compartments. This short paper focuses on fluorescent redox probes that are genetically encoded, and discusses their properties, molecular mechanism, advantages and pitfalls. Our recent work on reaction-based encoded probes that are responsive to particular redox signaling molecules is also reviewed. Future challenges and directions are also commented

    Design of ternary signals for MIMO identification in the presence of noise and nonlinear distortion

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    A new approach to designing sets of ternary periodic signals with different periods for multi-input multi-output system identification is described. The signals are pseudo-random signals with uniform nonzero harmonics, generated from Galois field GF(q), where q is a prime or a power of a prime. The signals are designed to be uncorrelated, so that effects of different inputs can be easily decoupled. However, correlated harmonics can be included if necessary, for applications in the identification of ill-conditioned processes. A design table is given for q les 31. An example is presented for the design of five uncorrelated signals with a common period N = 168 . Three of these signals are applied to identify the transfer function matrix as well as the singular values of a simulated distillation column. Results obtained are compared with those achieved using two alternative methods

    Acquirers’ prior related knowledge and post-acquisition integration: Evidences from four Chinese firms

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    Purpose – This paper examines the role of acquirers’ prior related knowledge in the post-acquisition integration process. The purpose of this paper is to identify what constitutes the key prior related knowledge that can contribute to the reverse knowledge transfer following Chinese firms’ outward mergers and acquisitions (M&As) to Europe, and explain how prior related knowledge affects such transfer of knowledge. Design/methodology/approach – The authors employ a multiple case study approach. Semi-structured interviews were conducted from February 2012 to June 2013 with 24 managers. Findings – The authors find that, in addition to knowledge about the target, prior international business experience, R&D capability, and industrial capabilities are key components of acquirers’ prior related knowledge that can contribute to the success of M&A integration and post-acquisition reverse knowledge transfer. Indeed, Chinese acquirers’ prior related knowledge can influence the reverse knowledge transfer from acquired firms to acquirers by directly improving acquirers’ absorptive capacity and building a harmonious organisational climate to facilitate such transfer. Originality/value – This paper contributes to the absorptive capacity and the cross-border M&A literature. It extends the current knowledge on the key components of an acquirer’s prior related knowledge in the outward M&A by Chinese firms. It also uncovers how post-acquisition reverse knowledge transfer is affected by acquirers’ prior related knowledge. Keywords M&A, Chinese firms, Post-acquisition integration, Absorptive capacity, Reverse knowledge transfer, P

    Utjecaj otopine u čvrstom stanju i starenja na mikrostrukturu i mehanička svojstva kompozita čestica SiCp/Al-Si-Cu-Mg

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    The SiC particles (SiCp, mass fraction 30 %) reinforced with the Al-Si-Cu-Mg matrix composite have been prepared using one-way press method, sintering, and hot extrusion. The composite was subjected to solid solution treatment at temperatures of 470 °C, 485 °C, 500 °C, 515 °C, and 530 °C for 4 h. The sample was then subjected to ageing treatment at temperatures of 160 °C and 180 °C during different times after solid solution treatment at 515 °C for 4 h. The microstructure and mechanical properties of the SiCp/Al-Si-Cu-Mg matrix composite under the different ageing and solid solution treatments were tested using SEM and TEM microhardness analysis. The results show that the white granulated metallic compounds of the SiCp/Al-Si-Cu-Mg composite materials, which are formed in the sintering process of composite materials, dissolve back after the solid solution treatment at different temperatures. The higher the solid solution temperature, the more metallic compounds dissolve back. The microhardness of the composites reached maximum after solution treatment at 515 °C for 4 h. Following the ageing treatment and with the prolongation of ageing time, the hardness of the composite material reached “double peak” phenomenon. With the increase in ageing temperature, the hardening speed of the composite material also increased, but at the same time, the hardening ability had reduced. After the ageing treatment, the second phases of the composite are discoid Al5Cu6Mg2. This work is licensed under a Creative Commons Attribution 4.0 International License.Pripravljen je kompozit čestica SiC (SiCp) u masenom udjelom 30 % u matrici Al-Si-Cu-Mg prešanjem, sinteriranjem i ekstrudiranjem. Kompozit je 4 sata bio izložen otapanju u čvrstom stanju pri 470 °C, 485 °C, 500 °C, 515 °C i 530 °C. Nakon toga na uzorak je 4 sata pri 515 °C djelovalo otapanje u čvrstom stanju, a zatim su uzorci starili različito vrijeme pri temperaturama 160 i 180 °C. Mikrostruktura i mehanička svojstva kompozita proučena su tehnikama pretražnom i transmisijskom mikroskopijom te analizom mikrotvrdoće. Pri sinteriranju kompozita SiCp/Al-Si-Cu-Mg nastaje bijeli zrnasti metalni spoj koji se otapa u čvrstu otopinu pri različitim temperaturama. Što je viša temperatura čvrste otopine, više se otopi metalnog spoja. Mikrotvrdoća doseže maksimum pri izlaganju reakcijama u čvrstom stanju pri 515 °C kroz četiri sata. Nakon starenja i s produljenjem starenja tvrdoća materijala pokazuje dvostruki vrh. S povišenjem temperature povećava se brzina očvršćivanja, no istodobno se smanjuje mogućnost očvršćenja. Druga faza kompozita nakon starenja je diskoidni Al5Cu6Mg2. Ovo djelo je dano na korištenje pod licencom Creative Commons Imenovanje 4.0 međunarodna
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