26 research outputs found

    Generating scalable graph states in an atom-nanophotonic interface

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    Scalable graph states are essential for measurement-based quantum computation and many entanglement-assisted applications in quantum technologies. Generation of these multipartite entangled states requires a controllable and efficient quantum device with delicate design of generation protocol. Here we propose to prepare high-fidelity and scalable graph states in one and two dimensions, which can be tailored in an atom-nanophotonic cavity via state carving technique. We propose a systematic protocol to carve out unwanted state components, which facilitates scalable graph states generations via adiabatic transport of a definite number of atoms in optical tweezers. An analysis of state fidelity is also presented, and the state preparation probability can be optimized via multiqubit state carvings and sequential single-photon probes. Our results showcase the capability of an atom-nanophotonic interface for creating graph states and pave the way toward novel problem-specific applications using scalable high-dimensional graph states with stationary qubits.Comment: 5 figures with supplemental materia

    Diffusion-weighted MRI, (11)C-choline PET and (18)F-fluorodeoxyglucose PET for predicting the Gleason score in prostate carcinoma

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    Objectives To evaluate the accuracy of transrectal ultrasoundguided (TRUS) biopsy, diffusion-weighted (DW) magnetic resonance imaging (MRI), ¹¹C-choline (CHOL) positron emission tomography (PET), and 18F-fluorodeoxyglucose (FDG) PET in predicting the prostatectomy Gleason risk (GR). Methods The study included 21 patients who underwent TRUS biopsy and multi-technique imaging before radical prostatectomy. Values from five different tests (TRUS biopsy, DW MRI, CHOL PET, FDG PET, and combined DW MRI/ CHOL PET) were correlated with the prostatectomy GR using Spearman’s ρ. Tests that were found to have significant correlations were used to classify patients into GR groups. Results The following tests had significant correlations with prostatectomy GR: TRUS biopsy (ρ=0.617, P =0.003), DW MRI (ρ=–0.601, P =0.004), and combined DW MRI/CHOL PET (ρ=–0.623, P =0.003). CHOL PET alone and FDG PET only had weak correlations. The correct GR classification rates were 67 % with TRUS biopsy, 67 % with DW MRI, and 76 % with combined DW MRI/CHOL PET. Conclusions DW MRI and combined DW MRI/CHOL PET have significant correlations and high rates of correct classification of the prostatectomy GR, the strength and accuracy of which are comparable with TRUS biopsy. Key Points • Accurate determination of the Gleason score is essential for prostate cancer management. • DW MRI ± CHOL PET correlated significantly with prostatectomy Gleason score. • These correlations are similar to that between TRUS biopsy and prostatectomyJoe H. Chang, Daryl Lim Joon, Sze Ting Lee, Chee-Yan Hiew, Stephen Esler, Sylvia J. Gong, Morikatsu Wada, David Clouston, Richard O, Sullivan, Yin P. Goh, Henri Tochon-Danguy, J. Gordon Chan, Damien Bolton, Andrew M. Scott, Vincent Khoo, Ian D. Davi

    Comparison of [(11)C]choline positron emission tomography with T2- and diffusion-weighted magnetic resonance imaging for delineating malignant intraprostatic lesions

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    Purpose: To compare the accuracy of ¹¹C-choline (CHOL) positron emission tomography (PET) with the combination of T2-weighted (T2W) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for delineating malignant intraprostatic lesions (IPLs) for guiding focal therapies and to investigate factors predicting the accuracy of CHOL-PET. Methods and Materials: This study included 21 patients who underwent CHOL-PET and T2W-/DW-MRI prior to radical prostatectomy. Two observers manually delineated IPL contours for each scan, and automatic IPL contours were generated on CHOL-PET based on varying proportions of the maximum standardized uptake value (SUV). IPLs identified on prostatectomy specimens defined the reference standard contours. The imaging-based contours were compared with the reference standard contours using Dice similarity coefficient (DSC), sensitivity and specificity. Factors that could potentially predict the DSC of the best contouring method were analyzed using linear models. Results: The best automatic contouring method, SUV60, had similar correlations (DSC 0.59) with the manual PET contours (DSC 0.52, P=0.127) and significantly better correlations than the manual MRI contours (DSC 0.37, P<0.001). The sensitivity and specificity values were 72% and 71% for SUV60; 53% and 86% for PET manual contouring; and 28% and 92% for MRI manual contouring. The tumor volume and transition zone pattern could independently predict the accuracy of CHOL-PET. Conclusions: CHOL-PET is superior to the combination of T2W- and DW-MRI for delineating IPLs. The accuracy of CHOL-PET is insufficient for gland-sparing focal therapies, 3 however may be accurate enough for focal boost therapies. The transition zone pattern is a new classification that may predict for how well CHOL-PET delineates IPLs.Joe H. Chang, Daryl Lim Joon, Ian D. Davis, Sze Ting Lee, Chee-Yan Hiew, Stephen Esler, Sylvia J. Gong, Morikatsu Wada, David Clouston, Richard O'Sullivan, Yin P. Goh, Damien Bolton, Andrew M. Scott, Vincent Kho

    The Advancement of Biomaterials in Regulating Stem Cell Fate.

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    Stem cells are well-known to have prominent roles in tissue engineering applications. Embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) can differentiate into every cell type in the body while adult stem cells such as mesenchymal stem cells (MSCs) can be isolated from various sources. Nevertheless, an utmost limitation in harnessing stem cells for tissue engineering is the supply of cells. The advances in biomaterial technology allows the establishment of ex vivo expansion systems to overcome this bottleneck. The progress of various scaffold fabrication could direct stem cell fate decisions including cell proliferation and differentiation into specific lineages in vitro. Stem cell biology and biomaterial technology promote synergistic effect on stem cell-based regenerative therapies. Therefore, understanding the interaction of stem cell and biomaterials would allow the designation of new biomaterials for future clinical therapeutic applications for tissue regeneration. This review focuses mainly on the advances of natural and synthetic biomaterials in regulating stem cell fate decisions. We have also briefly discussed how biological and biophysical properties of biomaterials including wettability, chemical functionality, biodegradability and stiffness play their roles

    Preprocessing of Fingerprint Images Captured with a Digital Camera

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    Reliable touch-less fingerprint recognition still remains a challenge nowadays as the conventional techniques that used to preprocess the optical or capacitance sensor acquired fingerprint image, for segmentation, enhancement and core point detection, are inadequate to serve the purpose. The problems of the touch-less fingerprint recognition are the low contrast between the ridges and the valleys in fingerprint images, defocus and motion blur. However, it imposes a competency for a further advancing of this biometric modality since it frees from the problems in terms of hygienic, maintenance and latent fingerprints. In this paper, the digital camera is opted as the device to capture the fingerprint image in RGB format and the procedures to segment, enhance and detect the core point of the fingerprint image are outlined

    Palmprint verification with moments

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    Palmprint verification is an approach for verifying a palmprint input by matching the input to the claimed identity template stored in a database. If the dissimilarity measure between the input and the claimed template is below the predefined threshold value, the palmprint input is verified possessing same identity as the claimed identity template. This paper introduces an experimental evaluation of the effectiveness of utilizing three well known orthogonal moments, namely Zernike moments, pseudo Zernike moments and Legendre moments, in the application of palmprint verification. Moments are the most commonly used technique in character feature extraction. The idea of implementing orthogonal moments as palmprint feature extractors is prompted by the fact that principal features of both character and palmprint are based on line structure. These orthogonal moments are able to define statistical and geometrical features containing line structure information about palmprint. An experimental study about verification rate of the palmprint authentication system using these three orthogonal moments as feature descriptors has been discussed here. Experimental results show that the performance of the system is dependent on the moment order as well as the type of moments. The orthogonal property of these moments is able to characterize independent features of the palmprint image and thus have minimum information redundancy in a moment set. Pseudo Zernike moments of order of 15 has the best performance among all the moments. Its verification rate is 95.75%, which also represents the overall performance of this palmprint verification system
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