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2.
BMC Ophthalmol ; 24(1): 203, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38684941

RESUMEN

BACKGROUND: This study aims to investigate the morphologic features of the crystalline lens in Primary Angle Closure Disease (PACD) patients with zonular instability during cataract surgery using the swept-source CASIA 2 Anterior Segment-Optical Coherence Tomography (AS-OCT) system. METHODS: A total of 398 eyes (125 PACD eyes with zonular instability, 133 PACD eyes with zonular stability, and 140 cataract patient controls) of 398 patients who underwent cataract surgery combined or not glaucoma surgery between January 2021 and January 2023 were enrolled. The crystalline lens parameters were measured by CASIA2 AS-OCT. Then, logistic regression was performed to evaluate the risk factors associated with zonular instability. RESULTS: The results revealed that PACD eyes had a more anterior lens equator position, a steeper anterior curvature of lens, shorter Axial Length (AL), shallower Anterior Chamber Distance (ACD), higher Lens Vault (LV) and thicker Lens Thickness (LT), when compared to eyes in the cataract control group. Furthermore, PACD eyes in the zonular instability group had steeper front R, front Rs and Front Rf, flatter back Rf, thicker lens anterior part thickness, higher lens anterior-to-posterior part thickness ratios, shallower ACD, and greater LV, when compared to PACD eyes with zonular stability. The logistic regression analysis, which was adjusted for age and gender, revealed that zonular instability was positively correlated with anterior part thickness, lens anterior-to-posterior part thickness ratio, and LV, but was negatively correlated with lens anterior radius and ACD. CONCLUSION: Steeper anterior curvature, increased lens anterior part thickness, higher anterior-to-posterior part thickness ratio, shallower ACD, and greater LV are the anatomic features of PACD eyes associated with zonular instability.


Asunto(s)
Segmento Anterior del Ojo , Glaucoma de Ángulo Cerrado , Cristalino , Tomografía de Coherencia Óptica , Humanos , Tomografía de Coherencia Óptica/métodos , Glaucoma de Ángulo Cerrado/fisiopatología , Glaucoma de Ángulo Cerrado/diagnóstico , Femenino , Masculino , Anciano , Persona de Mediana Edad , Segmento Anterior del Ojo/diagnóstico por imagen , Segmento Anterior del Ojo/patología , Cristalino/diagnóstico por imagen , Cristalino/patología , Estudios Retrospectivos , Presión Intraocular/fisiología , Agudeza Visual/fisiología
3.
Molecules ; 29(7)2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38611749

RESUMEN

Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer, with a high degree of malignancy and poor prognosis. Tumor-associated macrophages (TAMs) have been identified as significant contributors to the growth and metastasis of TNBC through the secretion of various growth factors and chemokines. Salvianolic acid A (SAA) has been shown to have anti-cancer activities. However, the potential activity of SAA on re-polarized TAMs remains unclear. As there is a correlation between the TAMs and TNBC, this study investigates the effect of SAA on TAMs in the TNBC microenvironment. For that purpose, M2 TAM polarization was induced by two kinds of TNBC-conditioned medium (TNBC-TCM) in the absence or presence of SAA. The gene and protein expression of TAM markers were analyzed by qPCR, FCM, IF, ELISA, and Western blot. The protein expression levels of ERK and p-ERK in M2-like TAMs were analyzed by Western blot. The migration and invasion properties of M2-like TAMs were analyzed by Transwell assays. Here, we demonstrated that SAA increased the expression levels of CD86, IL-1ß, and iNOS in M2-like TAMs and, conversely, decreased the expression levels of Arg-1 and CD206. Moreover, SAA inhibited the migration and invasion properties of M2-like TAMs effectively and decreased the protein expression of TGF-ß1 and p-ERK in a concentration-dependent manner, as well as TGF-ß1 gene expression and secretion. Our current findings for the first time demonstrated that SAA inhibits macrophage polarization to M2-like TAMs by inhibiting the ERK pathway and promotes M2-like TAM re-polarization to the M1 TAMs, which may exert its anti-tumor effect by regulating M1/M2 TAM polarization. These findings highlight SAA as a potential regulator of M2 TAMs and the possibility of utilizing SAA to reprogram M2 TAMs offers promising insights for the clinical management of TNBC.


Asunto(s)
Ácidos Cafeicos , Lactatos , Neoplasias de la Mama Triple Negativas , Humanos , Neoplasias de la Mama Triple Negativas/tratamiento farmacológico , Factor de Crecimiento Transformador beta1 , Microambiente Tumoral , Macrófagos Asociados a Tumores
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(3): 275-281, 2024 Mar 15.
Artículo en Chino | MEDLINE | ID: mdl-38557380

RESUMEN

OBJECTIVES: To investigate the nutritional status of children with cystic fibrosis (CF) and understand the correlation between malnutrition and clinical characteristics as well as lung function. METHODS: A retrospective analysis was performed on clinical data of CF children admitted from January 2016 to June 2023. Clinical characteristics of CF children with different nutritional statuses were compared, and the correlation between malnutrition and lung function was analyzed. RESULTS: A total of 52 CF children were included, comprising 25 boys (48%) and 27 girls (52%), aged between 7 months and 17 years. Respiratory symptoms were the predominant clinical manifestations (96%, 50/52). The prevalence of malnutrition was 65% (34/52), with moderate/severe malnutrition being the most common (65%, 22/34). The malnutrition group had a longer duration of illness, higher proportion of digestive system symptoms, and lower levels of serum albumin (P<0.05). Pulmonary function parameters, including forced expiratory volume in one second as a percentage of the predicted value, ratio of forced expiratory volume in one second to forced vital capacity, forced expiratory flow at 25% of forced vital capacity exhaled, forced expiratory flow at 50% of forced vital capacity exhaled, forced expiratory flow at 75% of forced vital capacity exhaled, and maximum mid-expiratory flow as a percentage of the predicted value, were lower in the malnutrition group compared to the normal nutrition group (P<0.05). Correlation analysis showed body mass index Z-score was positively correlated with the above six pulmonary function parameters (P<0.05). CONCLUSIONS: The prevalence of malnutrition is high in CF children and is associated with decreased lung function. CF children with higher body mass index have better lung function. Therefore, screening and evaluation of nutritional status as well as appropriate nutritional intervention should be emphasized in CF children.


Asunto(s)
Fibrosis Quística , Desnutrición , Niño , Masculino , Femenino , Humanos , Lactante , Estado Nutricional , Estudios Retrospectivos , Fibrosis Quística/complicaciones , Pulmón , Volumen Espiratorio Forzado , Desnutrición/etiología , Desnutrición/complicaciones
5.
Int J Ophthalmol ; 16(7): 1117-1122, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37465503

RESUMEN

AIM: To analyze the differences, agreements, and correlation among total corneal power parameters generated by different instruments after myopic keratorefractive surgery. METHODS: The prospective cross-sectional study included patients who underwent myopic keratorefractive surgery and received measurements of corneal power 3mo after surgery. Automated keratometer was used for the measurement of simulated keratometry (SimK), swept-source optical coherence tomography (SS-OCT) based biometer for total keratometry (TK), anterior segment-OCT for real keratometry (RK), and Scheimpflug keratometer for the true net power (TNP), the total corneal refractive power (TCRP) and equivalent K-readings (EKR). The differences among these parameters were analyzed, and the agreements and correlation between SimK and other total corneal power parameters were investigated. RESULTS: A total of 70 eyes of 70 patients after myopic keratorefractive surgery were included. The evaluated corneal power parameters were as follows: SimK 38.32±1.93 D, TK 37.54±2.12 D, RK 36.64±2.09 D, TNP 36.56±1.97 D, TCRP 36.70±2.01 D, and EKR 37.55±2.00 D. Pairwise comparison showed that there were significant differences (P<0.001) among all parameters except for between TK and EKR, RK and TNP, RK and TCRP (P=1.000, 1.000, 1.000, respectively). The limits of agreement between SimK and TK, RK, TNP, TCPR, and EKR were 1.08, 1.08, 1.43, 1.48, and 1.73 D, respectively. All parameters showed good correlation with SimK, and the correlation coefficients were 0.995, 0.994, 0.983, 0.982, and 0.975. CONCLUSION: Among the corneal power parameters after myopic keratorefractive surgery, the value of SimK is the largest, followed by TK and EKR, with TCRP, RK, and TNP being the smallest. The differences among the parameters may be attributable to the different calculation principles. Correct understanding and evaluation of corneal power parameters can provide a theoretical basis for taking advantage of the total corneal power to improve the accuracy of intraocular lens calculation after keratorefractive surgery.

6.
Biomed Environ Sci ; 36(5): 431-440, 2023 May 20.
Artículo en Inglés | MEDLINE | ID: mdl-37253669

RESUMEN

Objective: To develop a few-shot learning (FSL) approach for classifying optical coherence tomography (OCT) images in patients with inherited retinal disorders (IRDs). Methods: In this study, an FSL model based on a student-teacher learning framework was designed to classify images. 2,317 images from 189 participants were included. Of these, 1,126 images revealed IRDs, 533 were normal samples, and 658 were control samples. Results: The FSL model achieved a total accuracy of 0.974-0.983, total sensitivity of 0.934-0.957, total specificity of 0.984-0.990, and total F1 score of 0.935-0.957, which were superior to the total accuracy of the baseline model of 0.943-0.954, total sensitivity of 0.866-0.886, total specificity of 0.962-0.971, and total F1 score of 0.859-0.885. The performance of most subclassifications also exhibited advantages. Moreover, the FSL model had a higher area under curves (AUC) of the receiver operating characteristic (ROC) curves in most subclassifications. Conclusion: This study demonstrates the effective use of the FSL model for the classification of OCT images from patients with IRDs, normal, and control participants with a smaller volume of data. The general principle and similar network architectures can also be applied to other retinal diseases with a low prevalence.


Asunto(s)
Aprendizaje Profundo , Enfermedades de la Retina , Humanos , Tomografía de Coherencia Óptica , Enfermedades de la Retina/diagnóstico por imagen , Retina/diagnóstico por imagen , Curva ROC
7.
Anal Chim Acta ; 1252: 341056, 2023 Apr 29.
Artículo en Inglés | MEDLINE | ID: mdl-36935154

RESUMEN

Previous researches of covalent organic frameworks (COFs) have shown their potential as fluorescent probes, but the regulation of their optical properties and recognition characteristics still remains a challenge, and most of reports required complicated post-decoration to improve the sensing performance. In this context, we propose a novel in-situ strategy to construct uracil-conjugated COFs and modulate their fluorescence properties for sensitive and selective mercury(II) detection. By using 1,3,6,8-tetrakis(4-formylphenyl)pyrene (TFPPy) and 1,3,6,8-tetrakis(4-aminophenyl)pyrene (TAPPy) as fundamental blocks and 5-aminouraci (5-AU) as the functional monomer, a series of COFs (Py-COFs and Py-U-COFs-1 to Py-U-COFs-5) with tunable fluorescence were solvothermally synthesized through an in-situ Schiff base reaction. The π-conjugated framework serves as a signal reporter, the evenly and densely distributed uracil acts as a mercury(II) receptor, and the regular pores (channels) make the rapid and sensitive detection of the mercury(II) possible. In this research, we manage to regulate the crystalline structure, the fluorescence properties, and the sensing performance of COFs by simply changing the molar ratio of precursors. We expect this research to open up a new strategy for effective and controllable construction of functionalized COFs for environmental analysis.

8.
Phys Rev Lett ; 129(13): 130602, 2022 Sep 23.
Artículo en Inglés | MEDLINE | ID: mdl-36206414

RESUMEN

We investigate the connection between quantum resources and extractable work in quantum batteries. We demonstrate that quantum coherence in the battery or the battery-charger entanglement is a necessary resource for generating nonzero extractable work during the charging process. At the end of the charging process, we also establish a tight link of coherence and entanglement with the final extractable work: coherence naturally promotes the coherent work while coherence and entanglement inhibit the incoherent work. We also show that obtaining maximally coherent work is faster than obtaining maximally incoherent work. Examples ranging from the central-spin battery and the Tavis-Cummings battery to the spin-chain battery are given to illustrate these results.

9.
Phys Rev E ; 102(2-1): 022207, 2020 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32942418

RESUMEN

We develop linear stability analysis (LSA) to quantitatively predict the dynamics of a perturbed plane wave in nonlinear systems. We take a nonintegrable fiber model with purely fourth-order dispersion as an example to demonstrate this method's effectiveness. For a Gaussian-type initial perturbation with cosine-type modulation on a plane wave, its propagation velocities, periodicity, and localization are predicted successfully, and the range of application is discussed. Importantly, the modulation-instability-induced growth of localized perturbation is proved different from the one of purely periodic perturbation and requires the modification of gain value for more accurate prediction. The method offers a needful supplement and improvement for LSA and paves a way to study the dynamics of a perturbed plane wave in more practical nonlinear systems.

10.
Opt Lett ; 45(8): 2399-2402, 2020 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-32287243

RESUMEN

Peregrine rogue wave excitation has applications in gaining high-intensity pulses, etc., and a high-order rogue wave exhibits higher intensity. An exact solution and collision between breathers are two existing ways to excite high-order ones. Here we numerically report a new, to the best of our knowledge, possible method, which is by multi-Gaussian perturbations on a continuous wave. The order and maximal intensity of rogue waves can be adjusted by the number of perturbations. The maximal intensity approaches 63.8 times that of the power of the initial background wave, and it retains a large value under the influence of fiber loss and noise. Our results provide guidance in gaining high-intensity pulses in experiment and understanding the universality of rogue wave generation.

11.
Chaos ; 29(8): 083112, 2019 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-31472492

RESUMEN

We study numerically the evolutions of perturbations at critical points between modulational instability and stability regimes. It is demonstrated that W-shaped solitons and rogue waves can be both excited from weak resonant perturbations at the critical points. The rogue wave excitation at the critical points indicates that rogue wave comes from modulation instability with resonant perturbations, even when the baseband modulational instability is absent. The perturbation differences for generating W-shaped solitons and rogue waves are discussed in detail. These results can be used to generate W-shaped solitons and rogue waves controllably from weak perturbations.

12.
Acta Ophthalmol ; 97(7): e993-e997, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-30963731

RESUMEN

PURPOSE: To find the potential relation between changes in retinal large vessels and terminal vessels using colour Doppler flow imaging (CDFI) and optical coherence tomography angiography (OCTA) and to compare the respective advantages of CDFI and OCTA in evaluating vascular changes in retinitis pigmentosa (RP) patients. METHODS: A prospective series of case study was conducted to enrol RP patients and age-matched controls, who were, respectively, imaged by CDFI and OCTA. Repeatability and reproducibility of both CDFI and OCTA were performed among healthy volunteers. The central retinal artery (CRA) was detected by CDFI analysis to provide parameters of peak systolic velocity (PSV), end-diastolic velocity (EDV) and time-averaged maximum velocity (TAMV). Retinal parameters were evaluated from OCTA images, including vascular area density (VAD) of the superficial vascular layer, the fovea avascular zone (FAZ) area and retinal thickness. RP patients were separated into a high-vision group and a low-vision group, according to median vision (0.3, LogMAR 0.5). Multiple comparisons were used to analyse the data between groups. A correlation analysis was used to determine the correlation between CDFI and OCTA parameters. RESULTS: Twenty RP patients (40 eyes) and thirteen normal volunteers (26 eyes) were enrolled in this study. Repeatability and reproducibility of the measurements by CDFI had higher CVs, from 4.5% to 15.4%, than those measurements by OCTA (<5%). All the CDFI and OCTA parameters examined had significant reductions in RP patients compared to those in the controls (p < 0.01). Compared to the high-vision group, the low-vision group exhibited a statistically significant decrease in vascular parameters of the FAZ area, fovea VAD and parafovea nasal side VAD (p < 0.05); as well as in the parameters of the fovea thickness, and the parafovea nasal, superior and inferior side thickness (p < 0.05). From the correlation analysis, a significant association was found between the vision and CDFI parameters (PSV and time-averaged maximum velocity (TAMX), p < 0.05), and the vision and OCTA parameters (FAZ area, fovea and nasal side VAD, retinal thickness in all sides, p < 0.05). PSV and TAMX of the CRA were closely related to the OCTA superficial VAD in all sides, whereas the CDFI parameters showed poor correlation with retinal thickness. CONCLUSIONS: Colour Doppler flow imaging (CDFI) and OCTA parameters revealed a significant reduction in RP patients when compared to the controls. OCTA can detect vision-related microvascular and thickness changes around the macula between high- and low-vision groups, which happen earlier than the changes in large vessels. In addition to good repeatability and reproducibility, OCTA may have significant utility in the diagnosis and monitoring of disease progression in RP patients.


Asunto(s)
Velocidad del Flujo Sanguíneo/fisiología , Angiografía con Fluoresceína/métodos , Flujo Sanguíneo Regional/fisiología , Vasos Retinianos/diagnóstico por imagen , Retinitis Pigmentosa/diagnóstico , Tomografía de Coherencia Óptica/métodos , Ultrasonografía Doppler en Color/métodos , Adolescente , Adulto , Anciano , Femenino , Estudios de Seguimiento , Fondo de Ojo , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Vasos Retinianos/fisiopatología , Retinitis Pigmentosa/fisiopatología , Agudeza Visual , Adulto Joven
13.
Hua Xi Kou Qiang Yi Xue Za Zhi ; 37(1): 13-18, 2019 Feb 01.
Artículo en Chino | MEDLINE | ID: mdl-30854812

RESUMEN

OBJECTIVE: To investigate the effect of sex determining region Y-box 9 (SOX9) on epithelial mesenchymal transition (EMT) and cloning of oral squamous cell carcinoma (OSCC). METHODS: siRNA control, SOX9 siRNA were transfected into BcaCD885 cells in OSCC. Simultaneously, cells that did not undergo transfection were used as the control. Quantitative real time polymerase chain reaction (qRT-PCR) and Western blot were used to select SOX9 siRNA1 with enhanced interference effect. A cell cloning assay was used to determine the cell's clone formation ability. E-cadherin and Vimentin expressions were detected by immunofluorescence. The expressions of E-cadherin, matrix metalloprotease 2 (MMP-2), Vimentin and matrix metalloprotease 9 (MMP-9) were detected by Western blot. Cell invasion and migration were detected in the Transwell compartment. RESULTS: The levels of SOX9 mRNA and protein in SOX9 siRNA cells were significantly lower than those of the control (P<0.05). An increase in the number of SOX9 siRNA1 cell clonesled to the considerable decrease of the number of cell invasion and migration. In addition, levels of MMP-2 and MMP-9 proteins in cells decreased significantly compared with the control (P<0.05). The level of Vimentin expression in SOX9 siRNA1 cells decreased, and expression level of E-cadherin was elevated. Cell EMT was inhibited compared with the control, and the difference was statistically significant (P<0.05). CONCLUSIONS: Down-regulation of SOX9 inhibited EMT, clonogenic formation, cell invasion and OSCC migration.


Asunto(s)
Carcinoma de Células Escamosas , Transición Epitelial-Mesenquimal , Neoplasias de la Boca , Cadherinas , Línea Celular Tumoral , Movimiento Celular , Regulación hacia Abajo , Humanos , Vimentina
14.
Phys Rev E ; 99(1-1): 012216, 2019 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-30780219

RESUMEN

We study the excitation conditions of antidark solitons and nonrational W-shaped solitons in a nonlinear fiber with both third-order and fourth-order effects. We show that the relative phase can be used to distinguish antidark solitons and nonrational W-shaped solitons. The excitation conditions of these well-known fundamental nonlinear waves (on a continuous-wave background) can be clarified clearly by the relative phase and three previously reported parameters (background frequency, perturbation frequency, and perturbation energy). Moreover, the numerical simulations from the nonideal initial states also support these theoretical results. These results provide an important complement for the studies on relationship between modulation instability and nonlinear wave excitations, and are helpful for controllable nonlinear excitations in experiments.

15.
Sci Rep ; 8(1): 13960, 2018 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-30228294

RESUMEN

We investigate two-copy scenario of quantum teleportation based on Bell measurements. The detailed protocol is presented and the general expression of the corresponding optimal teleportation fidelity is derived, which is given by the two-copy fully entangled fraction that is invariant under local unitary transformations. We prove that under a specific case of the protocol, which is significant for improving the optimal fidelity, the set of states with their two-copy fully entangled fractions bounded by a threshold value that required for useful two-copy teleportation is convex and compact. Hence the witness operators exist to separate states that are useful for two-copy teleportation from the rest ones. Moreover, we show that the optimal fidelity of two-copy teleportation surpasses that of the original one copy teleportation.

16.
Chaos ; 28(8): 083110, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-30180607

RESUMEN

We report an exact link between Zakharov-Gelash super-regular (SR) breathers (formed by a pair of quasi-Akhmediev breathers) with interesting different nonlinear propagation characteristics and modulation instability (MI). This shows that the absolute difference of group velocities of SR breathers coincides exactly with the linear MI growth rate. This link holds for a series of nonlinear Schrödinger equations with infinite-order terms. For the particular case of SR breathers with opposite group velocities, the growth rate of SR breathers is consistent with that of each quasi-Akhmediev breather along the propagation direction. Numerical simulations reveal the robustness of different SR breathers generated from various non-ideal single and multiple initial excitations. Our results provide insight into the MI nature described by SR breathers and could be helpful for controllable SR breather excitations in related nonlinear systems.


Asunto(s)
Modelos Teóricos , Humanos
17.
Biomed Environ Sci ; 31(6): 407-412, 2018 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30025553

RESUMEN

OBJECTIVE: The aim of this study was to determine the repeatability and reproducibility of optical coherence tomography angiography (OCTA) based on optical microangiography (OMAG) measurements of macular vessels in normal eyes. METHODS: In this prospective cohort study, 40 eyes of 40 healthy volunteers underwent repeated OCTA (Cirrus HD-OCT 5000 angiography system, Carl Zeiss Meditec, Inc.) scans on two separate visit days. On each visit day, the eyes were scanned three times. The following parameters were used to quantitatively describe the OCTA images of the superficial vascular network: vessel area density (VAD), vessel skeleton density (VSD), vessel diameter index (VDI), vessel perimeter index (VPI), vessel complexity index (VCI), flux, and foveal avascular zone (FAZ). Coefficient of variation (CV) and intraclass correlation coefficient (ICC) were calculated for evaluating intravisit and intervisit repeatability, as well as interobserver reproducibility. RESULTS: The measurements showed high repeatability [CVs ⪕ 4.2% (intravisit) and ⪕ 4.6% (intervisit)] and interobserver reproducibility (ICCs ⪖ 0.923) for all parameters. CONCLUSION: This study demonstrated good repeatability and reproducibility of OCTA based on OMAG for the measurement of superficial vessel parameters in normal eyes.


Asunto(s)
Angiografía con Fluoresceína/normas , Microvasos/diagnóstico por imagen , Retina/diagnóstico por imagen , Vasos Retinianos/diagnóstico por imagen , Tomografía de Coherencia Óptica/normas , Adulto , Estudios de Cohortes , Estudios de Evaluación como Asunto , Femenino , Voluntarios Sanos , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Reproducibilidad de los Resultados , Adulto Joven
18.
Sci Rep ; 8(1): 11081, 2018 Jul 23.
Artículo en Inglés | MEDLINE | ID: mdl-30038348

RESUMEN

We investigate the behavior of coherence in scattering quantum walk search on complete graph under the condition that the total number of vertices of the graph is significantly larger than the marked number of vertices we are searching, N ≫ v. We find that the consumption of coherence represents the increase of the success probability for the searching, also it is related to the efficiency of the algorithm in oracle queries. If no coherence is consumed or an incoherent state is utilized, the algorithm will behave as the classical blind search, implying that coherence is responsible for the speed-up in this quantum algorithm over its classical counterpart. The effect of noises, in particular of photon loss and random phase shifts, on the performance of algorithm is studied. Two types of noise are considered because they arise in the optical network used for experimental realization of scattering quantum walk. It is found that photon loss will reduce the coherence and random phase shifts will hinder the interference between the edge states, both leading to lower success probability compared with the noise-free case. We then conclude that coherence plays an essential role and is responsible for the speed-up in this quantum algorithm.

19.
Chaos ; 28(1): 013111, 2018 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-29390636

RESUMEN

We investigate linear interference effects between a nonlinear plane wave and bright solitons, which are admitted by a pair-transition coupled two-component Bose-Einstein condensate. We demonstrate that the interference effects can induce several localized waves possessing distinctive wave structures, mainly including anti-dark solitons, W-shaped solitons, multi-peak solitons, Kuznetsov-Ma like breathers, and multi-peak breathers. Specifically, the explicit conditions for them are clarified by a phase diagram based on the linear interference properties. Furthermore, the interactions between these localized waves are discussed. The detailed analysis indicates that the soliton-soliton interaction induced phase shift brings the collision between these localized waves which can be inelastic for solitons involving collision and can be elastic for breathers. These characters come from the fact that the profile of solitons depends on the relative phase between bright solitons and a plane wave, and the profile of breathers does not depend on the relative phase. These results would motivate more discussions on linear interference between other nonlinear waves. Specifically, the solitons or breathers obtained here are not related to modulational instability. The underlying reasons are discussed in detail. In addition, possibilities to observe these localized waves are discussed in a two species Bose-Einstein condensate.

20.
Sci Rep ; 7(1): 14806, 2017 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-29093505

RESUMEN

We investigate the single qubit transformations under several typical coherence-free operations, such as, incoherent operation (IO), strictly incoherent operation (SIO), physically incoherent operation (PIO), and coherence-preserving operation (CPO). Quantitative connection has been built between IO and SIO in single qubit systems. Moreover, these coherence-free operations have a clear hierarchical relationship in single qubit systems: CPO ⊂ PIO ⊂ SIO=IO. A new and explicit proof for the necessary and sufficient condition of single qubit transformation via IO or SIO has been provided, which indicates that SIO with only two Kraus operators are enough to realize this transformation. The transformation regions of single qubits via CPO and PIO are also given. Our method provides a geometric illustration to analyze single qubit coherence transformations by introducing the Bloch sphere depiction of the transformation regions, and tells us how to construct the corresponding coherence-free operations.

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