Correlated fluorescence lifetime and spectral measurements in living cells

Studies of proteins' interaction in cells by FRET can take benefit from two important photo-physical properties describing fluorescent proteins: fluorescence emission spectrum and fluorescence lifetime. These properties provide specific and complementary information about the tagged proteins and their environment. However, none of them taken individually can completely quantify the involved fluorophore characteristics due to their multiparametric dependency with molecular environment, experimental conditions, and interpretation complexity. A solution to get a better understanding of the biological process implied at the cellular level is to combine the spectral and temporal fluorescence data acquired simultaneously at every cell region under investigation. We present the SLiM-SPRC160, an original temporal/spectral acquisition system for simultaneous lifetime measurements in 16 spectral channels directly attached to the descanned port of a confocal microscope with two-photon excitation. It features improved light throughput, enabling low-level excitation and minimum invasivity in living cells studies. To guarantee a fairly good level of accuracy and reproducibility in the measurements of fluorescence lifetime and spectra on living cells, we propose a rigorous protocol for running experiments with this new equipment that preserves cell viability. The usefulness of SLiM approach for the precise determination of overlapping fluorophores is illustrated with the study of known solutions of rhodamine. Then, we describe reliable FRET experiments in imaging mode realized in living cells using this protocol. We also demonstrate the benefit of localized fluorescence spectrum-lifetime acquisitions for the dynamic study of fluorescent proteins. proteins.     

Simple characterisation of a deformable mirror inside a high numerical aperture microscope using phase diversity

We present a simple and versatile scheme for characterising amplitude and phase modulation by an active element, such as a deformable mirror, in the pupil plane of a high NA microscope. By placing a mirror in the vicinity of the focal plane of the objective and recording images of the reflected focal spot on a camera, we show that reliable measurements of the influence function of the mirror actuators in the pupil plane of the objective can be obtained using an iterative electric field retrieval algorithm. Compared to direct wavefront sensors, the proposed method allows characterisation for a variety of objectives with different NA and pupil sizes without modification of the setup, requires minimal space inside the microscope, and can be used with pulsed sources such as used for multiphoton microscopy. In order to validate our method, we compare our data to the results obtained with a Shack-Hartmann wavefront sensor, and show that comparable precision is achieved.     

“江苏省造纸学会第十一届学术年会”隆重召开

2011年12月15日，由人民网举办的“2011造纸行业节能减排高层研讨会”在北京举行。研讨会上，山东亚太森博浆纸有限公司副董事长高德武、环保部华北督查中心处长刘恩东、中国轻工业环境保护研究所所长程言君、     

利用芳磺酸提高无液鞣革中的铬消耗

转鼓鞣制过程需要消耗大量的水和化学试剂,它们大多最终成为废水。本文探讨了一种可以在工业化条件下的替代传统浸酸铬鞣法的鞣革新方法。新方法用芳磺酸代替甲酸和硫酸,由于不用浴液,因此可以大幅度的减少盐和红矾钾盐的添加量,并可以提高鞣制过程最后阶段的温度。从环保角度看,新方法有更大的优势。例如,鞣革时无需添加浴液,另外,氯化物和铬的排放量分别减少了94%和99%,同时,残留浴液也减少了75%。新方法的经济效益也比传统方法节省42%。     

Single crystal silicon nanopillars, nanoneedles and nanoblades with precise positioning for massively parallel nanoscale device integration

Arrays of precisely positioned single crystal silicon nanopillars, nanoneedles, and nanoblades with minimum feature sizes as small as 30 nm are fabricated using entirely scalable top-down fabrication techniques. Using the same scalable technologies, devices consisting of electrically connected silicon nanopillars with multiple addressable electrodes for each nanostructure are realized. The arrays of nanopillars, nanoneedles, and nanoblades are shown to exhibit Raman signal enhancement on 1,2-benzenedithiol monolayers, opening a path to nanodevices that manipulate, position, detect and analyze molecules.     

海与船

正我觉得大家应该都喜欢船只吧,或许吸引我们的只是模型船上精美的涂装和高超的制作技巧。大多数时候看到这类作品,我们都会激动得浑身起鸡皮疙瘩。由于新挑战迫在眉睫,最近我一直在关注并阅读各种和模型船有关的一切。其中有一些被展示在海体上,而做出动感海洋的作品则少之又少。有些作者真的很有天赋,我受他们作品的鼓舞良多,也接受了不少很好的建议。要做好一艘船并不简单,但相信通过我们的技巧再加上一些小窍门就可以做出很好的作品。     

巴黎国立工艺美术酒店

正巴黎国立工艺美术酒店坐落于Marais区与Montorgueil街区之间,是CléGroup集团最新落成的酒店。该项目由耶路撒冷独立设计师Raphael Navot担任艺术指导,其独特大胆的设计向传统的制造工艺表达了敬意,同时也为人们提供了一种全新的巴黎生活体验。酒店的内部设计十分精致考究,尤其注重各个空间材料的选用。酒店共有66间不同风格的客房,位于一楼的餐厅和酒吧是该酒店的亮点。作为酒店的一部分,餐厅与酒吧位于巨大的玻璃屋顶之下,连接起了saint Martin与Reaumur两条大街。设计师结合Julien Cohen、Jean-Pierre Lopes与Thomas Delafon三位艺术家的美学理念,将这里变成了烹饪美食的理想之所。     

Lorentz Force Velocimetry for Local Velocity Measurement

Standard flow measurement techniques fail for liquid metals due to their high temperatures,opaqueness and aggressiveness.However,recent developments in the measurement of volumetric fluxes of industrially relevant metal melts have been made.One of these methods,Lorentz Force Velocimetry(LFV)is based on the measurement of Lorentz forces generated when an electrically conducting fluid moves through a magnetic field.Our aim is to extend the working range of this method to the measurement of local flow velocities.To resolve local velocity fluctuations we reduce the size of the permanent magnet that produces the magnetic field.We use the fundamental setup of a square duct filled with the eutectic alloy GalnSn and having a cross-section of 5 cm by 5 cm.The magnet cube employed has an edge length of 1 cm.For this setup,we investigate both experimentally and numerically the interaction between the liquid metal flow and the non-uniform magnetic field.The results help in understanding the effect of flow dynamics on the total Lorentz force.     

Noise Feedback Coding Revisited： Refurbished Legacy Codecs and New Coding Models

Noise feedback coding(NFC) has attracted renewed interest with the recent standardization of backward-compatible enhancements for ITU-T G.711 and G.722.It has also been revisited with the emergence of proprietary speech codecs,such as BV16,BV32,and SILK,that have structures different from CELP coding.In this article,we review NFC and describe a novel coding technique that optimally shapes coding noise in embedded pulse-code modulation(PCM) and embedded adaptive differential PCM(ADPCM).We describe how this new technique was incorporated into the recent ITU-T G.711.1,G.711 App.III,and G.722 Annex B(G.722B) speech-coding standards.