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Replica symmetry breaking (RSB) has been introduced in a random laser to investigate the interactions between disorder and fluctuations. In this work, the dynamic difference between four non-energy transfer and Förster resonance energy transfer (FRET)-assisted random laser systems is investigated based on RSB. It is found that FRET is one of the key factors influencing RSB, and it is demonstrated that RSB in a random laser is not robust. This dynamic difference can be attributed to the different disorders induced by the gain mechanism in different random laser systems. This provides experimental evidence and theoretical support for the classification feasibility of RL with different emission mechanisms employing RSB.
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A sound-induced flash illusion (SiFI) is a multisensory illusion dominated by auditory stimuli, in which the individual perceives that the number of visual flashes is equal to the number of auditory stimuli when visual flashes are presented along with an unequal number of auditory stimuli. Although the mechanisms underlying fission and fusion illusions have been documented, there is not yet a consensus on how they vary according to the different eccentricities. In the present study, by incorporating the classic SiFI paradigm into four different eccentricities, we aimed to investigate whether the SiFI varies under the different eccentricities. The results showed that the fission illusion varied significantly across the four eccentricities, with the perifovea (7°) and peripheral (11°) illusions being greater than the fovea and parafovea (3°) illusions. In contrast, the fusion illusion did not vary significantly across the four eccentricities. Our findings revealed that SiFI was affected by different visual fields and that there were differences between the fission and the fusion illusions. Furthermore, by examining the SiFI of eccentricity across visual fields, this study also suggests that bottom-up factors affect the SiFI.
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Ilusões , Humanos , Campos Visuais , Percepção Auditiva , Estimulação Acústica/métodos , Estimulação Luminosa/métodos , Percepção VisualRESUMO
Chitosan nanoparticles (NPs) serve as useful multidrug delivery carriers in cancer chemotherapy. Chitosan has considerable potential in drug delivery systems (DDSs) for targeting tumor cells. Doxorubicin (DOX) has limited application due to its resistance and lack of specificity. Chitosan NPs have been used for DOX delivery because of their biocompatibility, biodegradability, drug encapsulation efficiency, and target specificity. In this review, various types of chitosan derivatives are discussed in DDSs to enhance the effectiveness of cancer treatments. Modified chitosan-DOX NP drug deliveries with other compounds also increase the penetration and efficiency of DOX against tumor cells. We also highlight the endogenous stimuli (pH, redox, enzyme) and exogenous stimuli (light, magnetic, ultrasound), and their positive effect on DOX drug delivery via chitosan NPs. Our study sheds light on the importance of chitosan NPs for DOX drug delivery in cancer treatment and may inspire the development of more effective approaches for cancer chemotherapy.
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Quitosana , Nanopartículas , Neoplasias , Humanos , Sistemas de Liberação de Medicamentos , Doxorrubicina/farmacologia , Doxorrubicina/uso terapêutico , Neoplasias/tratamento farmacológicoRESUMO
BACKGROUND AND OBJECTIVES: Green tea is reported to have wide benefits on psychological states and cognitive functions. Studies that focus on the underlying neural mechanisms of green tea are limited to its single composition while people usually benefit from green tea water that contains various composition. In this study, we examined the human brain activity changes after drinking natural green tea by using regional homogeneity and functional connectivity based on the resting-state functional MRI technique. METHODS AND STUDY DESIGN: Fifteen healthy volunteers participated in two imaging sessions: a control (water) session and a green tea session, each session comprised a predrinking, drinking, and postdrinking section, during the drinking section, the subject consumed 200 mL of green tea infusion or water in 3 to 5 minutes. Then the post-tea and post-water imaging data were selected for regional homogeneity and functional connectivity analysis. RESULTS: Our results revealed that, compared with the control group, the green tea group exhibited an increased regional homogeneity in the frontal, parietal, and occipital areas of the brain, decreased regional homogeneity values in the left cuneus and left lingual gyrus, mainly a decreased functional connectivity in the default mode network, somatosensory, visual cortex, and parieto-frontal areas and enhanced functional connectivity in brain regions associated with memory. CONCLUSIONS: This result indicates that green tea consumption impacts the brain activity during resting state.
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Encéfalo/efeitos dos fármacos , Encéfalo/fisiologia , Imageamento por Ressonância Magnética , Chá , Adolescente , Adulto , Feminino , Humanos , Masculino , Adulto JovemRESUMO
The discovery of a new type of soliton occurring in periodic systems is reported. This type of nonlinear excitation exists at a Dirac point of a photonic band structure, and features an oscillating tail that damps algebraically. Solitons in periodic systems are localized states traditionally supported by photonic bandgaps. Here, it is found that besides photonic bandgaps, a Dirac point in the band structure of triangular optical lattices can also sustain solitons. Apart from their theoretical impact within the soliton theory, they have many potential uses because such solitons are possible in both Kerr material and photorefractive crystals that possess self-focusing and self-defocusing nonlinearities. The findings enrich the soliton family and provide information for studies of nonlinear waves in many branches of physics.
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The large absolute photonic bandgaps of two-dimensional (2D) anisotropic magnetic plasma photonic crystals with hexagonal and square lattices are obtained by introducing tellurium dielectric rods using the modified plane wave expansion method. Equations for calculating the band structures in the irreducible part of the first Brillouin zone are theoretically deduced. The modulation properties indicate that the location and bandwidth of the absolute photonic bandgaps (PBGs) could be tuned by filling factor, plasma frequency, and magnetic field. The effective tunable ranges and critical values of these parameters are found. These results could be helpful in designing 2D anisotropic PPCs with large absolute PBGs.
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Optical cavities and waveguides are critical parts of modern optical devices. Traditionally, optical cavities and waveguides rely on photonic bandgaps, or total internal reflection, to achieve light trapping. It has been reported that a novel light trapping, which exists in triangular and honeycomb lattices, is attributed to the so-called Dirac point. Our analysis reveals that 2D triangular Archimedean-like lattice photonic crystals also can support this Dirac mode with similar characteristics. This is a new type of localized mode with a different algebraic field profile at a different specified Dirac frequency, which is also beyond any complete photonic bandgap. The new wave localization has different features and can be applied to the design of new optical devices.
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BACKGROUND: Hepatic pregnancy is a very rare form of ectopic pregnancy, potentially life-threatening for the mother. CASE: A 33-year-old woman presented with intermittent pain in the upper abdomen of 5 days' duration. An abdominopelvic ultrasound scan was performed, which demonstrated hepatic pregnancy. Later, abdominal computed tomography (CT) and magnetic resonance imaging (MRI) in coronal and axial confirmed the findings and delineated exactly the regional anatomy before surgery. Laparotomy was successfully performed according to the preoperative diagnosis. CONCLUSION: The application of imaging techniques (ultrasound, CT, and MRI scan) is very useful in hepatic pregnancy for defining the regional anatomy in greater detail and is critical in minimizing surgical injury.
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Fígado , Gravidez Ectópica/diagnóstico , Gravidez Ectópica/cirurgia , Diagnóstico Pré-Natal/métodos , Adulto , Feminino , Idade Gestacional , Humanos , Imageamento por Ressonância Magnética , Gravidez , Gravidez Ectópica/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Ultrassonografia Pré-NatalRESUMO
A particular photonic crystal fiber (PCF) designed with all circle air holes is proposed. Its characteristics are studied by full-vector finite element method (FEM) with anisotropic perfectly matched layer (PML). The simulation results indicated that the proposed PCF can realize high birefringence (up to 10(-2)), high nonlinearity (50W(-1)·km(-1) and 68W(-1)·km(-1) in X and Y polarizations respectively) and low confinement loss (less than 10(-3)dB/km at 1.55um wavelength).
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A polarization splitter based on a new type of dual-core photonic crystal fiber (DC-PCF) is proposed. The effects of geometrical parameters of the DC-PCF on performances of the polarization splitter are investigated by finite element method (FEM). The numerical results demonstrate that the polarization splitter possesses ultra-short length of 119.1 µm and high extinction ratio of 118.7 dB at the wavelength of 1.55 µm. Moreover, an extinction ratio greater than 20 dB is achieved over a broad bandwidth of 249 nm, i.e., from 1417 nm to 1666 nm, covering the S, C and L communication bands.
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Background: Freezing of gait (FOG) is common in the late stage of Parkinson's disease (PD), which can lead to disability and impacts the quality of life. Therefore, early recognition is crucial for therapeutic intervention. We aimed to explore the abnormal regional homogeneity (ReHo) and functional connectivity (FC) in FOG converters and evaluate their diagnostic values. Methods: The data downloaded from the Parkinson's Disease Progression Markers Project (PPMI) cohort was subdivided into PD-FOG converters (n = 16) and non-converters (n = 17) based on whether FOG appeared during the 3-year follow-up; 16 healthy controls were well-matched. ReHo and FC analyses were used to explore the variations in spontaneous activity and interactions between significant regions among three groups of baseline data. Correlations between clinical variables and the altered ReHo values were assessed in FOG converter group. Last, logistic regression and receiver operating characteristic curve (ROC) were used to predict diagnostic value. Results: Compared with the non-converters, FOG converters had reduced ReHo in the bilateral medial superior frontal gyrus (SFGmed), which was negatively correlated with the postural instability and gait difficulty (PIGD) score. ReHo within left amygdala/olfactory cortex/putamen (AMYG/OLF/PUT) was decreased, which was correlated with anxiety and autonomic dysfunction. Also, increased ReHo in the left supplementary motor area/paracentral lobule was positively correlated with the rapid eye movement sleep behavior disorder screening questionnaire. FOG converters exhibited diminished FC in the basal ganglia, limbic area, and cognitive control cortex, as compared with non-converters. The prediction model combined ReHo of basal ganglia and limbic area, with PIGD score was the best predictor of FOG conversion. Conclusion: The current results suggested that abnormal ReHo and FC in the basal ganglia, limbic area, and cognitive control cortex may occur in the early stage of FOG. Basal ganglia and limbic area dysfunction combined with higher PIGD score are useful for the early recognition of FOG conversion.
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This study aimed to form a novel emulsion gel (EG) through structured oil phase of natural component beeswax (BW), together with ovalbumin (OVA), and to investigate the mechanism of its formation and stabilization in terms of microstructure and processing properties. Confocal laser scanning microscopy (CLSM) demonstrated that the EG formed a continuous double network structure since the superior crystallinity of the oil phase was given by BW. Fourier transform infrared spectroscopy (FT-IR) illustrated that the acylation of the phenolic hydroxyl group in BW with an amide bond in OVA, increased the hydrogen bonding of EG. Furthermore, the immobilization of the oil phase results in better thermal and freeze-thaw stability of EG. Finally, EG was used as a curcumin delivery system, and the presence of BW significantly improved its adaptability to multiple environmental factors. In summary, our study would provide valuable ideas for developing the design of finely structured functional food.
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Ceras , Emulsões/química , Ovalbumina/química , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
BACKGROUND AND OBJECTIVES: Pathologic progression across the cortex is a key feature of Parkinson disease (PD). Cortical gyrification is a morphologic feature of human cerebral cortex that is tightly linked to the integrity of underlying axonal connectivity. Monitoring cortical gyrification reductions may provide a sensitive marker of progression through structural connectivity, preceding the progressive stages of PD pathology. We aimed to examine the progressive cortical gyrification reductions and their associations with overlying cortical thickness, white matter (WM) integrity, striatum dopamine availability, serum neurofilament light (NfL) chain, and CSF α-synuclein levels in PD. METHODS: This study included a longitudinal dataset with baseline (T0), 1-year (T1), and 4-year (T4) follow-ups and 2 cross-sectional datasets. Local gyrification index (LGI) was computed from T1-weighted MRI data to measure cortical gyrification. Fractional anisotropy (FA) was computed from diffusion-weighted MRI data to measure WM integrity. Striatal binding ratio (SBR) was measured from 123Ioflupane SPECT scans. Serum NfL and CSF α-synuclein levels were also measured. RESULTS: The longitudinal dataset included 113 patients with de novo PD and 55 healthy controls (HCs). The cross-sectional datasets included 116 patients with relatively more advanced PD and 85 HCs. Compared with HCs, patients with de novo PD showed accelerated LGI and FA reductions over 1-year period and a further decline at 4-year follow-up. Across the 3 time points, the LGI paralleled and correlated with FA (p = 0.002 at T0, p = 0.0214 at T1, and p = 0.0037 at T4) and SBR (p = 0.0095 at T0, p = 0.0035 at T1, and p = 0.0096 at T4) but not with overlying cortical thickness in patients with PD. Both LGI and FA correlated with serum NfL level (LGI: p < 0.0001 at T0, p = 0.0043 at T1; FA: p < 0.0001 at T0, p = 0.0001 at T1) but not with CSF α-synuclein level in patients with PD. In the 2 cross-sectional datasets, we revealed similar patterns of LGI and FA reductions and associations between LGI and FA in patients with more advanced PD. DISCUSSION: We demonstrated progressive reductions in cortical gyrification that were robustly associated with WM microstructure, striatum dopamine availability, and serum NfL level in PD. Our findings may contribute biomarkers for PD progression and potential pathways for early interventions of PD.
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Doença de Parkinson , alfa-Sinucleína , Humanos , Imageamento por Ressonância Magnética , Doença de Parkinson/diagnóstico por imagem , Doença de Parkinson/patologia , Estudos Transversais , Dopamina , Córtex Cerebral/patologia , BiomarcadoresRESUMO
Background: Obstructive Sleep Apnea (OSA) characteristically leads to nocturnal hypoxia and sleep disturbance. Despite clear evidence of OSA-induced cognitive impairments, the literature offers no consensus on the relationship between these pathophysiological processes and brain structure alterations in patients. Objective: This study leverages the robust technique of structural equation modeling to investigate how hypoxia and sleep disturbance exert differential effects on gray matter structures. Methods: Seventy-four Male participants were recruited to undergo overnight polysomnography and T1-weighted Magnetic Resonance Imaging. Four structural outcome parameters were extracted, namely, gray matter volume, cortical thickness, sulcal depth, and fractal dimension. Structural equation models were constructed with two latent variables (hypoxia, and sleep disturbance) and three covariates (age, body mass index, and education) to examine the association between gray matter structural changes in OSA and the two latent variables, hypoxia and sleep disturbance. Results: The structural equation models revealed hypoxia-associated changes in diverse regions, most significantly in increased gray matter volume, cortical thickness and sulcal depth. In contrast, sleep disturbance. Was shown to be largely associated with reduce gray matter volume and sulcal depth. Conclusion: This study provides new evidence showing significant effects of OSA-induced hypoxia and sleep disturbance on gray matter volume and morphology in male patients with obstructive sleep apnea. It also demonstrates the utility of robust structural equation models in examining obstructive sleep apnea pathophysiology.
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Background and purpose: Obstructive sleep apnoea is associated with excessive daytime sleepiness due to sleep fragmentation and hypoxemia, both of which can lead to abnormal brain morphology. However, the pattern of brain structural changes associated with excessive daytime sleepiness is still unclear. This study aims to investigate the effects of excessive daytime sleepiness on cortical thickness in patients with obstructive sleep apnoea. Materials and methods: 61 male patients with newly diagnosed obstructive sleep apnoea were included in the present study. Polysomnography and structural MRI were performed for each participant. Subjective daytime sleepiness was assessed using the Epworth Sleepiness Scale score. Surface-based morphometric analysis was performed using Statistical Parametric Mapping 12 and Computational Anatomy 12 toolboxes to extract cortical thickness. Results: Using the median Epworth Sleepiness Scale score, patients were divided into the non-sleepiness group and the sleepiness group. The cortical thickness was markedly thinner in the sleepiness group in the left temporal, frontal, and parietal lobe and bilateral pre- and postcentral gyri (pFWE < 0.05). There was a significant negative correlation between the cortical thickness and the Epworth Sleepiness Scale score. After adjusting for age, body mass index, and obstructive sleep apnoea severity, the Epworth Sleepiness Scale score remained an independent factor affecting the cortical thickness of the left middle temporal lobe, transverse temporal and temporal pole. Conclusion: Subjective daytime sleepiness is associated with decreased cortical thickness, and the Epworth Sleepiness Scale score may be of utility as a clinical marker of brain injury in patients with obstructive sleep apnoea.
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OBJECTIVE: We evaluated the effect of short-term and long-term heroin abstinence on brain responses to heroin-related cues using functional magnetic resonance imaging (fMRI). METHODS: Eighteen male heroin addicts following short-term abstinence and 19 male heroin addicts following long-term abstinence underwent fMRI scanning while viewing heroin-related and neutral images. Cue-elicited craving and withdrawal symptoms in the subjects were measured. RESULTS: Following short-term abstinence, greater activation was found in response to heroin cues compared to neutral cues in bilateral temporal, occipital, posterior cingulate, anterior cingulate, thalamus, cerebellum, and left hippocampus. In contrast, activations in bilateral temporal and occipital and deactivations in bilateral frontal, bilateral parietal, left posterior cingulate, insula, thalamus, dorsal striatum, and bilateral cerebellum were observed following long-term abstinence. Direct comparisons between conditions showed greater brain reactivity in response to smoking cues following short-term abstinence. In addition, short-term abstinence had more serious withdrawal symptoms than the long-term. CONCLUSION: The present findings indicate that compared to short-term, long-term abstinence manifests less serious withdrawal symptoms and significantly decreases neural responses to heroin-related cues in brain regions subserving visual sensory processing, attention, memory, and action planning. These findings suggest that long-term abstinence can decrease the salience of conditioned cues, thereby reducing the risk of relapses. The study's limitations are noted.
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Encéfalo/metabolismo , Sinais (Psicologia) , Dependência de Heroína/fisiopatologia , Dependência de Heroína/psicologia , Síndrome de Abstinência a Substâncias/psicologia , Adulto , China , Humanos , Imageamento por Ressonância Magnética , Masculino , Estimulação Luminosa/métodos , Projetos Piloto , Fatores de TempoRESUMO
The sound-induced flash illusion (SiFI) is a robust auditory-dominated multisensory integration phenomenon that is used as a reliable indicator to assess multisensory integration. Previous studies have indicated that the SiFI effect is correlated with perceptual sensitivity. However, to date, there is no consensus regarding how it corresponds to sensitivity with long-term training. The present study adopted the classic SiFI paradigm with feedback training to investigate the effect of a week of long-term training on the SiFI effect. Both the training group and control group completed a pretest and a posttest before and after the perceptual training; however, only the training group was required to complete 7-day behavioral training. The results showed that (1) long-term training could reduce the response of fission and fusion illusions by improving perceptual sensitivity and that (2) there was a "plateau effect" that emerged during the training stage, which tended to stabilize by the fifth day. These findings demonstrated that the SiFI effect could be modified with long-term training by ameliorating perceptual sensitivity, especially in terms of the fission illusion. Therefore, the present study supplements perceptual training in SiFI domains and provides evidence that the SiFI could be used as an assessment intervention to improve the efficiency of multisensory integration.
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Ilusões , Estimulação Acústica , Percepção Auditiva/fisiologia , Humanos , Ilusões/fisiologia , Estimulação Luminosa/métodos , Percepção Visual/fisiologiaRESUMO
Cell membranes are heterogeneous and consist of liquid-ordered (Lo) and liquid-disordered (Ld) phases due to phase separation. Membrane regulation of egg white peptides (LCAY and QVPLW) was confirmed in our previous study. However, the underlying mechanism of phase regulation by the peptides has not been elucidated. This study aimed to explore the effect of LCAY and QVPLW on the membrane phase separation and illustrate their mechanism by giant unilamellar vesicles (GUVs). Based on phase separation visualization, LCAY and QVPLW were found to increase the Lo phase by rearranging lipids and ordering the Ld phase. LCAY and QVPLW can bind to the GUVs and localize in the amphiphilic region of the membrane. By hydrogen bonds and hydrophobic interactions, LCAY and QVPLW may play a cholesterol-like role in regulating phase separation.
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Clara de Ovo , Lipossomas Unilamelares , Membrana Celular , Colesterol , PeptídeosRESUMO
Cyperus esculentus starch was treated by pullulanase debranching and nanoprecipitation to prepare resistant starch nanoparticles. Amylose contents, rheological properties of debranched starch and the size, crystalline structure, resistant starch contents of the prepared starch nanoparticles were investigated. The results of amylose contents showed that enzymatic hydrolysis 4 h was the most appropriate enzymatic hydrolysis time. Dynamic light scattering analysis and scanning electron microscopy observations showed that when the starch solution was added to the ethanol, the larger the amount of ethanol, the more conducive to the formation of small size starch nanoparticles. When volume ratio of starch solution/ethanol was 1/5, the particle size was 271.1 nm, the content of resistant starch was higher (15.28%). X-ray diffraction results indicated that resistant starch nanoparticles had V-type crystalline structure. Pullulanase debranching and nanoprecipitation can be utilized to prepare smaller size of Cyperus esculentus resistant starch with higher efficiency.
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Nanopartículas , Amido Resistente , Amilose , Tamanho da Partícula , Amido , Difração de Raios XRESUMO
Purpose: This study aimed to develop machine learning models for the diagnosis of Parkinson's disease (PD) using multiple structural magnetic resonance imaging (MRI) features and validate their performance. Methods: Brain structural MRI scans of 60 patients with PD and 56 normal controls (NCs) were enrolled as development dataset and 69 patients with PD and 71 NCs from Parkinson's Progression Markers Initiative (PPMI) dataset as independent test dataset. First, multiple structural MRI features were extracted from cerebellar, subcortical, and cortical regions of the brain. Then, the Pearson's correlation test and least absolute shrinkage and selection operator (LASSO) regression were used to select the most discriminating features. Finally, using logistic regression (LR) classifier with the 5-fold cross-validation scheme in the development dataset, the cerebellar, subcortical, cortical, and a combined model based on all features were constructed separately. The diagnostic performance and clinical net benefit of each model were evaluated with the receiver operating characteristic (ROC) analysis and the decision curve analysis (DCA) in both datasets. Results: After feature selection, 5 cerebellar (absolute value of left lobule crus II cortical thickness (CT) and right lobule IV volume, relative value of right lobule VIIIA CT and lobule VI/VIIIA gray matter volume), 3 subcortical (asymmetry index of caudate volume, relative value of left caudate volume, and absolute value of right lateral ventricle), and 4 cortical features (local gyrification index of right anterior circular insular sulcus and anterior agranular insula complex, local fractal dimension of right middle insular area, and CT of left supplementary and cingulate eye field) were selected as the most distinguishing features. The area under the curve (AUC) values of the cerebellar, subcortical, cortical, and combined models were 0.679, 0.555, 0.767, and 0.781, respectively, for the development dataset and 0.646, 0.632, 0.690, and 0.756, respectively, for the independent test dataset, respectively. The combined model showed higher performance than the other models (Delong's test, all p-values < 0.05). All models showed good calibration, and the DCA demonstrated that the combined model has a higher net benefit than other models. Conclusion: The combined model showed favorable diagnostic performance and clinical net benefit and had the potential to be used as a non-invasive method for the diagnosis of PD.