58 research outputs found

    State transfer in dissipative and dephasing environments

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    By diagonalization of a generalized superoperator for solving the master equation, we investigated effects of dissipative and dephasing environments on quantum state transfer, as well as entanglement distribution and creation in spin networks. Our results revealed that under the condition of the same decoherence rate γ\gamma, the detrimental effects of the dissipative environment are more severe than that of the dephasing environment. Beside this, the critical time tct_c at which the transfer fidelity and the concurrence attain their maxima arrives at the asymptotic value t0=π/2λt_0=\pi/2\lambda quickly as the spin chain length NN increases. The transfer fidelity of an excitation at time t0t_0 is independent of NN when the system subjects to dissipative environment, while it decreases as NN increases when the system subjects to dephasing environment. The average fidelity displays three different patterns corresponding to N=4r+1N=4r+1, N=4r1N=4r-1 and N=2rN=2r. For each pattern, the average fidelity at time t0t_0 is independent of rr when the system subjects to dissipative environment, and decreases as rr increases when the system subjects to dephasing environment. The maximum concurrence also decreases as NN increases, and when NN\rightarrow\infty, it arrives at an asymptotic value determined by the decoherence rate γ\gamma and the structure of the spin network.Comment: 12 pages, 6 figure

    Teleportation of the one-qubit state with environment-disturbed recovery operations

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    We study standard protocol P0\mathcal{P}_0 for teleporting the one-qubit state with both the transmission process of the two qubits constitute the quantum channel and the recovery operations performed by Bob disturbed by the decohering environment. The results revealed that Bob's imperfect operations do not eliminate the possibility of nonclassical teleportation fidelity provided he shares an ideal channel state with Alice, while the transmission process is constrained by a critical time t0,ct_{0,c} longer than which will result in failure of P0\mathcal{P}_0 if the two qubits are corrupted by the decohering environment. Moreover, we found that under the condition of the same decoherence rate γ\gamma, the teleportation protocol is significantly more fragile when it is executed under the influence of the noisy environment than those under the influence of the dissipative and dephasing environments.Comment: 8 pages, 4 figure

    Various correlations in a Heisenberg XXZ spin chain both in thermal equilibrium and under the intrinsic decoherence

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    In this paper we discuss various correlations measured by the concurrence (C), classical correlation (CC), quantum discord (QD), and geometric measure of discord (GMD) in a two-qubit Heisenberg XXZ spin chain in the presence of external magnetic field and Dzyaloshinskii-Moriya (DM) anisotropic antisymmetric interaction. Based on the analytically derived expressions for the correlations for the cases of thermal equilibrium and the inclusion of intrinsic decoherence, we discuss and compare the effects of various system parameters on the correlations in different cases. The results show that the anisotropy Jz is considerably crucial for the correlations in thermal equilibrium at zero temperature limit but ineffective under the consideration of the intrinsic decoherence, and these quantities decrease as temperature T rises on the whole. Besides, J turned out to be constructive, but B be detrimental in the manipulation and control of various quantities both in thermal equilibrium and under the intrinsic decoherence which can be avoided by tuning other system parameters, while D is constructive in thermal equilibrium, but destructive in the case of intrinsic decoherence in general. In addition, for the initial state Ψ1(0)>=12(01>+10>)|\Psi_1(0) > = \frac{1}{\sqrt{2}} (|01 > + |10 >), all the correlations except the CC, exhibit a damping oscillation to a stable value larger than zero following the time, while for the initial state Ψ2(0)>=12(00>+11>)|\Psi_2(0) > = \frac{1}{\sqrt{2}} (|00 > + |11 >), all the correlations monotonously decrease, but CC still remains maximum. Moreover, there is not a definite ordering of these quantities in thermal equilibrium, whereas there is a descending order of the CC, C, GMD and QD under the intrinsic decoherence with a nonnull B when the initial state is Ψ2(0)>|\Psi_2(0) >.Comment: 8 pages, 7 figure

    Experimental characterisation of textile compaction response: A benchmark exercise

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    This paper reports the results of an international benchmark exercise on the measurement of fibre bed compaction behaviour. The aim was to identify aspects of the test method critical to obtain reliable results and to arrive at a recommended test procedure for fibre bed compaction measurements. A glass fibre 2/2 twill weave and a biaxial (±45°) glass fibre non-crimp fabric (NCF) were tested in dry and wet conditions. All participants used the same testing procedure but were allowed to use the testing frame, the fixture and sample geometry of their choice. The results showed a large scatter in the maximum compaction stress between participants at the given target thickness, with coefficients of variation ranging from 38% to 58%. Statistical analysis of data indicated that wetting of the specimen significantly affected the scatter in results for the woven fabric, but not for the NCF. This is related to the fibre mobility in the architectures in both fabrics. As isolating the effect of other test parameters on the results was not possible, no statistically significant effect of other test parameters could be proven. The high sensitivity of the recorded compaction pressure near the minimum specimen thickness to changes in specimen thickness suggests that small uncertainties in thickness can result in large variations in the maximum value of the compaction stress. Hence, it is suspected that the thickness measurement technique used may have an effect on the scatter

    Sensing behavior of metal-free porphyrin and zinc phthalocyanine thin film towards xylene-styrene and hcl vapors in planar optical waveguide

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    The sensing behavior of a thin film composed of metal-free 5, 10, 15, 20-tetrakis (p-hydroxy phenyl) porphyrin and zinc phthalocyanine complex towards m-xylene, styrene, and HCl vapors in a homemade planar optical waveguide (POWG), was studied at room temperature. The thin film was deposited on the surface of potassium ion-exchanged glass substrate, using vacuum spin-coating method, and a semiconductor laser light (532 nm) as the guiding light. Opto-chemical changes of the film exposing with hydrochloric gas, m-xylene, and styrene vapor, were analyzed firstly with UV-Vis spectroscopy. The fabricated POWG shows good correlation between gas exposure response and absorbance change within the gas concentration range 10–1500 ppm. The limit of detection calculated from the logarithmic calibration curve was proved to be 11.47, 21.08, and 14.07 ppm, for HCl gas, m-xylene, and styrene vapors, respectively. It is interesting to find that the film can be recovered to the initial state with trimethylamine vapors after m-xylene, styrene exposures as well as HCl exposure. The gas-film interaction mechanism was discussed considering protonation and π-π stacking with planar aromatic analyte molecules

    In vitro antifungal susceptibility of Trichophyton violaceum isolated from tinea capitis patients

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    PubMedID: 25492394Objectives: Trichophyton violaceum is an anthropophilic dermatophyte that is endemic to parts of Africa and Asia and is sporadic in Europe. T. violaceum mainly causes tinea capitis in both children and adolescents. Although the infections caused by T. violaceum are of considerable medical importance, its antifungal susceptibility profile remains poorly examined. Methods: In this study, we tested the in vitro antifungal susceptibility of a set of clinical T. violaceum isolates obtained from tinea capitis patients, using the CLSI broth microdilution method. We tested eight antifungals and used isolates collected from Western China (21), Eastern China (12), the Middle East (1), Europe (20), South Africa (7) and Canada (1). Results: The geometric means of the MICs of the antifungals for all isolates were as follows (in increasing order): posaconazole, 0.021 mg/L; terbinafine, 0.023 mg/L; voriconazole, 0.062 mg/L; amphotericin B, 0.20 mg/L; itraconazole, 0.34 mg/L; caspofungin, 0.56 mg/L; fluconazole, 4.23 mg/L; and flucytosine, 8.46 mg/L. No statistically significant differences in the susceptibility profiles of T. violaceum were detected within the geographical regions tested. Conclusions: Posaconazole, terbinafine and voriconazole were shown to be the most potent antifungal agents against T. violaceum isolates obtained from tinea capitis patients worldwide. These results might help clinicians in developing appropriate therapies that have a high probability of successfully treating tinea capitis due to T. violaceum. © The Author 2014.Islamic Azad University 2012211A063This study was supported in part by Program 973 (2013CB531601, 2013CB531606) and Fund 2013ZX10004612 of Severe Infectious Disease of China, and the Xinjiang Nature Science Fund No. 2012211A063 of China; and by the CBS-KNAW Fungal Biodiversity Centre, Utrecht, The Netherlands, and the Department of Medical Microbiology, Radboudumc, Nijmegen, The Netherlands, and the Department of Medical Mycology and Parasitology, Faculty of Medicine and Medical Sciences, Islamic Azad University, Ardabil Branch, Ardabil, Iran

    The Potential of a CT-Based Machine Learning Radiomics Analysis to Differentiate Brucella and Pyogenic Spondylitis

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    Parhat Yasin,1 Muradil Mardan,2 Dilxat Abliz,3 Tao Xu,1 Nuerbiyan Keyoumu,4 Abasi Aimaiti,4 Xiaoyu Cai,1 Weibin Sheng,1 Mardan Mamat1 1Department of Spine Surgery, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 830054, People’s Republic of China; 2School of Medicine, Tongji University, Shanghai, 200092, People’s Republic of China; 3Department of Orthopedic, The Eighth Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 830054, People’s Republic of China; 4Department of Anesthesiology, The First Affiliated Hospital of Xinjiang Medical University, Urumqi, Xinjiang, 830054, People’s Republic of ChinaCorrespondence: Mardan Mamat, Tel +86 0991-4365316, Email [email protected]: Pyogenic spondylitis (PS) and Brucella spondylitis (BS) are common spinal infections with similar manifestations, making their differentiation challenging. This study aimed to explore the potential of CT-based radiomics features combined with machine learning algorithms to differentiate PS from BS.Methods: This retrospective study involved the collection of clinical and radiological information from 138 patients diagnosed with either PS or BS in our hospital between January 2017 and December 2022, based on histopathology examination and/or germ isolations. The region of interest (ROI) was defined by two radiologists using a 3D Slicer open-source platform, utilizing blind analysis of sagittal CT images against histopathological examination results. PyRadiomics, a Python package, was utilized to extract ROI features. Several methods were performed to reduce the dimensionality of the extracted features. Machine learning algorithms were trained and evaluated using techniques like the area under the receiver operating characteristic curve (AUC; confusion matrix-related metrics, calibration plot, and decision curve analysis to assess their ability to differentiate PS from BS. Additionally, permutation feature importance (PFI; local interpretable model-agnostic explanations (LIME; and Shapley additive explanation (SHAP) techniques were utilized to gain insights into the interpretabilities of the models that are otherwise considered opaque black-boxes.Results: A total of 15 radiomics features were screened during the analysis. The AUC value and Brier score of best the model were 0.88 and 0.13, respectively. The calibration plot and decision curve analysis displayed higher clinical efficiency in the differential diagnosis. According to the interpretation results, the most impactful features on the model output were wavelet LHL small dependence low gray-level emphasis (GLDN).Conclusion: The CT-based radiomics models that we developed have proven to be useful in reliably differentiating between PS and BS at an early stage and can provide a reliable explanation for the classification results.Keywords: Brucella spondylitis, Pyogenic spondylitis, machine learning, radiomics, model interpretatio

    In vitro antifungal susceptibility of Trichophyton violaceum isolated from tinea capitis patients

    No full text
    OBJECTIVES: Trichophyton violaceum is an anthropophilic dermatophyte that is endemic to parts of Africa and Asia and is sporadic in Europe. T. violaceum mainly causes tinea capitis in both children and adolescents. Although the infections caused by T. violaceum are of considerable medical importance, its antifungal susceptibility profile remains poorly examined. METHODS: In this study, we tested the in vitro antifungal susceptibility of a set of clinical T. violaceum isolates obtained from tinea capitis patients, using the CLSI broth microdilution method. We tested eight antifungals and used isolates collected from Western China (21), Eastern China (12), the Middle East (1), Europe (20), South Africa (7) and Canada (1). RESULTS: The geometric means of the MICs of the antifungals for all isolates were as follows (in increasing order): posaconazole, 0.021 mg/L; terbinafine, 0.023 mg/L; voriconazole, 0.062 mg/L; amphotericin B, 0.20 mg/L; itraconazole, 0.34 mg/L; caspofungin, 0.56 mg/L; fluconazole, 4.23 mg/L; and flucytosine, 8.46 mg/L. No statistically significant differences in the susceptibility profiles of T. violaceum were detected within the geographical regions tested. CONCLUSIONS: Posaconazole, terbinafine and voriconazole were shown to be the most potent antifungal agents against T. violaceum isolates obtained from tinea capitis patients worldwide. These results might help clinicians in developing appropriate therapies that have a high probability of successfully treating tinea capitis due to T. violaceum
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