1,434 research outputs found

    Towards clinical translation of raman spectroscopy for tumor cell identification

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    In the modern world, cancer is one of the leading causes of death, and its early diagnostics remains one of the big challenges. Since cancer starts as a malfunction on the cellular level, the diagnostic techniques have to deal with single cells. Detection of circulating tumor cells (CTCs), which are present in the patient's blood, holds promise for the future theranostic applications, as CTCs represent the actual state of the primary tumor. Raman spectroscopy is a label-free technique capable of non-destructive and chemically-specific characterization of individual cells. In contrast to marker-based methods, the CTCs detected by Raman can be reused for more specific single-cells biochemical analysis methods. This thesis focuses on technological developments for Raman-based CTC identification, and encompasses the whole chain of involved methods and processes, including instrumentation and microfluidic cell handling, automation of spectra acquisition and storage, and chemometric data analysis. It starts with a design of custom application-specific instruments that we used to evaluate and optimize different experimental parameters. A major part is software development for automated acquisition and organized storage of spectral data in a database. With the automated measurement systems and the database in place, we were able to collect about 40.000 Raman spectra of more than 15 incubated cancer cell lines, healthy donor leukocytes, as well as samples originating from clinical patients. Additionally, the thesis gives an overview of data analysis methods and provides an insight into the underlying trends of the dataset. Although the cell identification models could not reliably differentiate between individual cancer cell lines, they were able to recognize tumor cells among healthy leukocytes with prediction accuracy of more than 95%. This work demonstrated an increase in the throughput of Raman-based CTC detection, and provides a basis for its clinical translation

    Quantum repeater via entangled phase modulated multimode coherent states

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    We present a scheme of quantum repeater that uses entangled multimode coherent states which are obtained by electro-optic modulation of symmetric and antisymmetric Schr\"odinger cat states. In this method subcarrier modes of the phase modulated states generated by the remote parties are sent to a symmetric beam splitter at the central node. The entangled coherent states are heraldedly prepared by photon counting measurements at the output channels of the beam splitter. We study how the effects of decoherence in the quantum channel affect statistics of photocounts and corresponding fidelity. We show how the proposed scheme can be useful for extending range of quantum key distribution with sub carrier wave encoding by exploiting quantum teleportation with the generated entanglement.Comment: 14 pages, 8 figure

    Theoretical analysis of quantum key distribution systems when integrated with a DWDM optical transport network

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    A theoretical research and numerical simulation of the noise influence caused by spontaneous Raman scattering, four-wave mixing, and linear channel crosstalk on the performance of QKD systems was conducted. Three types of QKD systems were considered: coherent one-way (COW) QKD protocol, subcarrier-wave (SCW) QKD system, and continuous-variable (CV) QKD integrated with classical DWDM channels. We calculate the secure key generation rate for the systems mentioned addressing different channel allocation schemes (i.e., configurations). A uniform DWDM grid is considered with quantum channel located in C-band and O-band (at 1310 nm) of a telecommunication window. The systems' performance is analyzed in terms of the maximal achievable distance values. Configurations for the further analysis and investigation are chosen optimally, i.e., their maximal achievable distances are the best

    Tungstate and Carbonate Ions Sorption Using Anion Exchangers AV-17-8 and Purolite A400

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    The current paper shows the results of tungstate and carbonate ion sorption using strongly basic anion exchangers AV-17-8 and Purolite A400. It has been established that anion exchanger AV-17-8 in the chloride form with parameters of 168 g of tungstate ion and 157 g of carbonate ion per 1 kg of anion exchanger has the maximum capacity for the tungstate and carbonate ions

    Data transmission in long-range dielectric-loaded surface plasmon polariton waveguides

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    In this paper we report successful transmission of 10 Gbit/s on-off-keying (OOK) modulated signal through the LR-DLSPPWs with almost negligible degradation of the data flow consistenc
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