435 research outputs found

    Modulation-frequency encoded multi-wavelength fluorescence analysis

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    We introduce a principle of parallel optical processing: modulation-frequency-encoded multi-wavelength laser excitation, fluorescence detection with a single detector, and Fourier analysis decoding. As an example, we demonstrate simultaneous detection of DNA fragments from different origins

    Multi-color fluorescent DNA analysis in an optofluidic chip

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    Modulation-frequency-encoded fluorescence excitation enables the identification of end-labeled DNA samples of different genetic origin during their electrophoretic separation, opening perspectives for intrinsic size calibration, malign / healthy sample comparison, and exploitation of multiplex ligation-dependent probe amplification

    Multimode interference devices for focusing in microfluidic channels

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    Low-cost, compact, automated optical microsystems for chemical analysis, such as microflow cytometers for identification of individual biological cells, require monolithically integrated microlenses for focusing in microfluidic channels, to enable high-resolution scattering and fluorescence measurements. The multimode interference device (MMI), which makes use of self-imaging in multimode waveguides, is shown to be a simple and effective alternative to the microlens for microflow cytometry. The MMIs have been designed, realized, and integrated with microfluidic channels in a silica-based glass waveguide material system. Focal spot sizes of 2.4 µm for MMIs have been measured at foci as far as 43.7 µm into the microfluidic channel

    Sub-base-pair resolution during DNA separation in an optofluidic chip

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    DNA sequencing in a lab-on-a-chip aims at providing cheap, high-speed analysis of low reagent volumes to, e.g., identify genomic deletions or insertions associated with genetic illnesses. Detecting single base-pair insertions or deletions from DNA fragments in the diagnostically relevant range of 150-1000 base-pairs requires a sizing accuracy of S < 10^-3, while only S < 10^-2 were reported. Here we demonstrate a sizing accuracy of S = 4 x 10^-4, thereby paving the way for the envisaged applications

    Malware Defense in Mobile Network using Dynamic Analysis of Android Application

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    Today Android has the biggest market share as compared to other operating system for smart phone. As users are continuously increasing day by day the Security is one of the main concerns for Smartphone users. As the features and power of Smartphone are increase, so that they has their vulnerability for attacks by Malwares. But the android is the operating system which is more secure than any other operating systems available for Smart phones. The Android operating system has very few restrictions for developers and it will increase the security risk for end users. I am proposing an android application which is able to perform dynamic analysis on android program. To perform this analysis i have to deploy the android application, In this proposed system I am going to deploy android application on a cloud. This application executes automatically without any human interaction. It automatically detects malware by using pattern matching algorithm. If malware get detected then user get inform that particular application is malicious and restrict the user from installing application. DOI: 10.17762/ijritcc2321-8169.150315

    Review of Malware Defense in Mobile Network using Dynamic Analysis of Android Application

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    Today Android has the biggest market share as compared to other operating system for smart phone. As users are continuously increasing day by day the Security is one of the main concerns for Smartphone users. As the features and power of Smartphone are increase, so that they has their vulnerability for attacks by Malwares. But the android is the operating system which is more secure than any other operating systems available for Smart phones. The Android operating system has very few restrictions for developers and it will increase the security risk for end users. In this paper we have reviewed android security model, application level security in android and its security issues

    Integrated optics sensors for multi-sensing platforms

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    An overview is presented of research projects on optical sensing, in the Integrated Optical MicroSystems group of the MESA+ Institute for Nanotechnology at the University of Twente

    Characterization of femtosecond laser written waveguides for integrated biochemical sensing

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    Fluorescence detection is known to be one of the most sensitive among the different optical sensing techniques. This work focuses on excitation and detection of fluorescence emitted by DNA strands labeled with fluorescent dye molecules that can be excited at a specific wavelength. Excitation occurs via optical channel waveguides written with femtosecond laser pulses applied coplanar with a microfluidic channel on a glass chip. The waveguides are optically characterized in order to facilitate the design of sensing structures which can be applied for monitoring the spatial separation of biochemical\ud species as a result of capillary electrophoresis

    Optical sensing in microchip capillary electrophoresis by femtosecond laser written waveguides

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    Capillary electrophoresis separation in an on-chip integrated microfluidic channel is typically monitored with bulky, bench-top optical excitation/detection instrumentation. Optical waveguides allow confinement and transport of light in the chip directing it to a small volume of the microfluidic channel and collecting the emitted/transmitted radiation. However, the fabrication of optical waveguides or more complex photonic components integrated with the microfluidic channels is not a straightforward process, since it requires a localized increase of the refractive index of the substrate.\ud Recently, a novel technique has emerged for the direct writing of waveguides and photonic circuits in transparent glass substrates by focused femtosecond laser pulses.\ud In this work we demonstrate the integration of femtosecond laser written optical waveguides into a commercial microfluidic chip. We fabricate high quality waveguides intersecting the microchannels at arbitrary positions and use them to optically address with high spatial selectivity their content. In particular, we apply our technique to integrate optical detection in microchip capillary electrophoresis. Waveguides are inscribed at the end of the separation channel in order to optically excite the different plugs reaching that point; fluorescence from the labelled biomolecules crossing the waveguide output is efficiently collected at a 90° angle by a high numerical aperture optical fiber. The sensitivity of the integrated optical detection system was first evaluated filling the chip with a dye solution, obtaining a minimum detectable concentration of 40 pM. \ud After dynamic coating of the microchannels with an EPDMA polymer we demonstrate electrophoresis of an oligonucleotide plug with concentration down to 1 nM and wavelength-selective monitoring of on-chip separation of three fluorescent dyes. Work is in progress on separation and detection of fluorescent-labeled DNA fragments, targeting specific, diagnostically relevant regions of a template DNA, for application to the detection of chromosome aberrations

    Role of immigrant males and muzzle contacts in the uptake of a novel food by wild vervet monkeys.

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    The entry into and uptake of information in social groups is critical for behavioral adaptation by long-lived species in rapidly changing environments. We exposed five groups of wild vervet monkeys to a novel food to investigate the innovation of processing and consuming it. We report that immigrant males innovated in two groups, and an infant innovated in one group. In two other groups, immigrant males imported the innovation from their previous groups. We compared uptake between groups with respect to the initial innovator to examine the extent to which dispersing males could introduce an innovation into groups. Uptake of the novel food was faster in groups where immigrant males ate first rather than the infants. Younger individuals were more likely overall, and faster, to subsequently acquire the novel food. We also investigated the role of muzzle contact behavior in information seeking around the novel food. Muzzle contacts decreased in frequency over repeated exposures to the novel food. Muzzle contacts were initiated the most by naïve individuals, high rankers, and juveniles; and were targeted most towards knowledgeable individuals and high rankers, and the least towards infants. We highlight the potential importance of dispersers in rapidly exploiting novel resources among populations
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