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A Pilot Study of F-18 FP-CIT PET Imaging in Early-onset Patients with Parkinson’s Disease: Parkin versus Non-parkin Mutation
摘要： Striatal dopaminergic dysfunction in early-onset Parkinson’s disease (PD) remains to be further elucidated. Thus, as a preliminary study, we aimed to investigate detailed patterns of dopaminergic depletion in five early-onset PD patients with dynamic N-(3-[(18) F]fluoropropyl)-2-carbomethoxy-3-(4-iodophenyl) nortropane (FP-CIT) positron emission tomography (PET) scans. Two patients with parkin mutation showed more symmetric decrease of dopamine transporter (DAT) density in the putamen, whereas others displayed asymmetric reduction of DAT density in the putamen. Notably, only those with parkin mutation revealed more severe dopaminergic deficits in the anteroventral putamen rather than the posterodoral putamen. Our observation suggests, among PD patients, patients with parkin mutation may exhibit the different pattern of striatal dopaminergic depletion.
关键词： Parkinson’s Disease,Parkin Mutation,Early-Onset,Dopamine Depletion
更新于2025-09-23 15:23:52
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Robust conductive micropatterns on PTFE achieved via selective UV- induced graft copolymerization for flexible electronic applications
摘要： Fabrication of stable and functional patterns on the surface of polytetrafluoroethylene (PTFE) remains a great technical challenge owing to its inertness and high hydrophobicity. Here, we report for the first time the fabrication of functional micro-patterns on the PTFE surface by selectively irradiating plasma-treated PTFE coated with the monomer solution. A series of uniform, highly dense polydopamine methacrylamide (denoted as PDMA) line patterns with the line/pitch width 20μm/20μm and 50μm/50μm were fabricated on the surface of PTFE (denoted as PDMA-p/PTFE) using dopamine methacrylamide (DMA) as the monomer. The surface graft copolymerization occurs attributed to the universal adsorption of DMA and the low grafting energy barrier, comparing with the polymerization energy barrier, which is also demonstrated by the density functional theory (DFT) calculations. Further, robust, well-defined metal Ag or Cu patterns with the strong adhesion strength are fabricated on the surface the PTFE film by electroless deposition, and demonstrated for applications in flexible electronics. The approach is demonstrated to be versatile for fabrication of PDMA micropatterns onto a wide range of polymeric substrates including polypropylene (PP), and acrylonitrile butadiene styrene (ABS).
关键词： dopamine methacrylamide,UV irradiation,graft copolymerization,metal patterns,Surface grafting,PTFE
更新于2025-09-23 15:23:52
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Lack of cone mediated retinal function increases susceptibility to form-deprivation myopia in mice
摘要： Retinal photoreceptors are important in visual signaling for normal eye growth in animals. We used Gnat2 cplf3/cplf3 (Gnat2-/-) mice, a genetic mouse model of cone dysfunction to investigate the influence of cone signaling in ocular refractive development and myopia susceptibility in mice. Refractive development under normal visual conditions was measured for Gnat2-/- and age-matched Gnat2+/+ mice, every 2 weeks from 4 to 14 weeks of age. Weekly measurements were performed on a separate cohort of mice that underwent monocular form-deprivation (FD) in the right eye from 4 weeks of age using head-mounted diffusers. Refraction, corneal curvature, and ocular biometrics were obtained using photorefraction, keratometry and optical coherence tomography, respectively. Retinas from FD mice were harvested, and analyzed for dopamine (DA) and 3,4-dihydroxyphenylacetate (DOPAC) using high-performance liquid chromatography. Under normal visual conditions, Gnat2+/+ and Gnat2-/- mice showed similar refractive error, axial length, and corneal radii across development (p>0.05), indicating no significant effects of the Gnat2 mutation on normal ocular refractive development in mice. Three weeks of FD produced a significantly greater myopic shift in Gnat2-/- mice compared to Gnat2+/+ controls (-5.40 ± 1.33 D vs -2.28 ± 0.28 D, p=0.042). Neither the Gnat2 mutation nor FD altered retinal levels of DA or DOPAC. Our results indicate that cone pathways needed for high acuity vision in primates are not as critical for normal refractive development in mice, and that both rods and cones contribute to visual signalling pathways needed to respond to FD in mammalian eyes.
关键词： mouse,form-deprivation,dopamine,Gnat2,Refractive error,cone photoreceptors
更新于2025-09-23 15:23:52
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Poly(dopamine) and Ag nanoparticle-loaded TiO <sub/>2</sub> nanotubes with optimized antibacterial and ROS-scavenging bioactivities
摘要： Aim: To create polydopamine (PDA) and Ag nanoparticle-loaded TiO2 nanotubes coating on titanium (Ti) alloy. Materials & methods: TiO2-PDA-Ag coating was fabricated on Ti implants by electrochemical anodization. The in vitro and in vivo bactericidal and antibiofilm activities were tested. Intracellular reactive oxygen species (ROS) and antioxidative capability were measured, and cell proliferation, adhesion and cell morphology were characterized. Results: TiO2-PDA-Ag coating showed satisfactory bactericidal and antibiofilm activities in vitro and in vivo, improved Ag release pattern, evident ROS scavenging properties and enhanced cell adhesion and proliferation. Conclusion: Our study successfully fabricated a PDA and Ag nanoparticle-loaded TiO2 nanotubes coating on Ti alloy. The improved Ag release kinetics and ROS-scavenging properties achieve an optimal balance between antibacterial ability and biocompatibility.
关键词： antibacterial,nanotubular structures,enhanced adhesion,ROS scavenging,poly(dopamine)
更新于2025-09-23 15:22:29
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Dopamine Binding and Analysis in Undiluted Human Serum and Blood by the RNA-Aptamer Electrode
摘要： Specific analysis of such neurotransmitters as dopamine by the aptamer electrodes in biological fluids is detrimentally affected by non-specific adsorption of media, particularly pronounced at positive charges of the electrode surface at which dopamine oxidizes. Here, we show that dopamine analysis at the RNA-aptamer/cysteamine-modified electrodes is strongly inhibited in undiluted human serum and blood due to non-specific interfacial adsorption of serum and blood components. We demonstrate that non-specific adsorption of serum proteins (but not of blood components) could be minimized when analysis is performed in a flow and injections of serum samples are followed by washing steps in a phosphate buffer solution (PBS) carrier. Under those conditions, the dopamine-aptamer binding affinity in whole human serum of (1.9±0.3)×104 M-1 s-1 was comparable to (3.7±0.3)×104 M-1 s-1 found in PBS, and the dopamine oxidation signal linearly depended on the dopamine concentration, providing the sensitivity of analysis of 73 ± 3 nA μM-1 cm-2 and the LOD of 114 ± 8 nM. The flow-injection apatmer-electrode system was used for direct analysis of basal levels of dopamine in undiluted human serum samples, without using any physical separators (membranes) or filtration procedures. The results suggest a simple strategy for combatting biosurface fouling most pronounced at positive electrode potentials and assist in designing more efficient antifouling strategies for biomedical applications.
关键词： Human serum,Blood,Surface fouling,RNA aptamer electrode,Dopamine,Chronoamperometry,Electrochemical Impedance,Flow-through cell
更新于2025-09-23 15:22:29
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Silver nanoflowers-enhanced Tb(III)/La(III) co-luminescence for the sensitive detection of dopamine
摘要： A sensitive fluorescent analytical method for the detection of dopamine (DA) was developed based on surface-enhanced Tb(III)/La(III) co-luminescence using silver nanoflowers (AgNFs). Anisotropic AgNFs show strong surface-enhanced fluorescence effect owing to the abundant sharp tips. Tb(III)/La(III)-DA complexes mainly bind to the sharp tips of AgNFs and thus shorten the distance between the complexes. The shortened distance gives rise to obvious surface-enhanced Tb(III)/La(III) co-luminescence effect. In this work, AgNFs offer many superior properties, such as enhanced intrinsic green fluorescence of Tb(III) (λex/λem = 310/546 nm), increased fluorescence lifetime, and improved energy transfer efficiency. Under the optimum conditions, the fluorescence intensity is linearly correlated with the concentration of DA in the range of 0.80–10 nM (R2 = 0.9970), and the detection limit is 0.34 nM (S/N = 3). The fluorescent nanoprobe was successfully applied to the determination of DA in human serum samples with recoveries ranging from 99.1 to 102.6%.
关键词： Co-luminescence,Anisotropic nanoparticles,Surface-enhanced fluorescence,Rare earth elements,Dopamine,Silver nanoflowers
更新于2025-09-23 15:22:29
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A high-performance fluorescent probe for dopamine detection based on g-C3N4 nanofibers
摘要： A novel fluorescent sensor based on g-C3N4 nanofibers for the sensitive detection of dopamine (DA) has been proposed. We synthesized g-C3N4 nanofibers by directly hydrolyzing bulk g-C3N4 in the alkaline atmosphere (3 M NaOH). The obtained ultrathin g-C3N4 nanofibers were verified by characterizations of Transmission electronic microscope (TEM), X-ray diffractometer (XRD), Fourier transformation-infrared (FT-IR) and X-Ray photoelectron spectroscopy (XPS). It was found that the fluorescence intensity of g-C3N4 nanofibers was obviously quenched by DA. Fluorescence resonance energy transfer (FRET) between DA and g-C3N4 nanofibers led to the fluorescence reduction of g-C3N4 nanofibers. The fluorescent probe based on g-C3N4 nanofibers exhibits linear responses to the concentration of DA in the range from 0 to 4 μM and 4 to 20 μM, the limit of detection is 17 nM. The fluorescent probe shows excellent stability, good selectivity with its application in serums.
关键词： dopamine,g-C3N4 nanofibers,quenching,fluorescent probe
更新于2025-09-23 15:22:29
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[IEEE 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Budapest (2018.7.1-2018.7.5)] 2018 IEEE 2nd International Conference on Dielectrics (ICD) - Improving Surface flashover Performance of LDPE by Dopamine Based on Bionic Technology
摘要： In this paper, dc vacuum surface flashover properties of low density polyethylene (LDPE) film covered with dopamine (Dp)-silver (Ag)-Dopamine (Dp) sandwich structure on the surface by immersing LDPE in dopamine solution(6h), silver nitrate (0.5h, 1h, 2h, 4h) and dopamine (24h) solution in order was researched. Scanning electron microscopic (SEM), surface potential decay (SPD) and Keithley 6517B were used as characterization methods to evaluate surface morphology, surface trap distribution and surface conductivity separately. These parameters may reveal the influence mechanism of Dp-Ag-Dp sandwich structure on samples surface. SEM images shows that nano-Ag particles attaching on the surface of samples and their size and quantity become larger with silver nitrate solution immersing time prolonging. SPD results indicates that both shallow and deep trap depth move to the deeper direction with increasing modification time, while shallow trap and deep trap density decreases first and then increases with the increase of treating time. Surface conductivity enlarges over silver nitrate processing time. For dc vacuum surface flashover voltage, the results presents that its value increases with silver nitrate treatment time when the samples were soaked in silver nitrate solution for less than 2h. It can be concluded that by modifying surface parameters like trap distribution and surface conductivity covering LDPE film surface with dopamine-silver-dopamine sandwich structure can change dc vacuum surface flashover performance.
关键词： trap distribution,dc surface flashover,dopamine
更新于2025-09-23 15:22:29
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In-situ synthesis of gold nanocrystals anchored graphene oxide and its application in biosensor and chemical sensor
摘要： This research demonstrated the development of graphene oxide (GO)-gold nanocrystals (AuNCs) composite-modified glassy carbon electrode (GCE) for the sensitive detection of dopamine (DA), uric acid (UA), and 4-aminophenol (4-AP). The GO was synthesized by modified Hummer’s method, which was utilized to prepare GO-AuNCs composites by in situ synthesis method using sodium L(-) malate as a reducing agent. Morphological, X-ray diffraction, and spectral analysis revealed the homogeneous formation of AuNCs with high crystallinity and purity on the GO surface and the sizes of the NCs were decreased with increasing the concentrations of sodium L(-) malate. The optimal GCE/GO-AuNCs sensor exhibited excellent electrocatalytic activity towards the oxidation of DA, UA, and 4-AP. The sensor showed interference-free and selective detection of DA and UA with sensitivities of ca. 30.3 and 17.28 μA/cm2/μM, respectively, and detection limits of ca. 28 and 50 nM, respectively, with wider dynamic ranges, measured by differential pulse voltammetry (DPV) technique. Whereas, it displayed a sensitivity and detection limit of ca. 5.70 μA/cm2/mM and 0.017 nM, respectively, for the detection of 4-AP, using current density (J)-voltage (V) measurement method. The sensor also revealed excellent stability, reproducibility, and recoveries of DA, UA, and 4-AP in real samples.
关键词： dopamine,4-aminophenol,Graphene Oxide-Au nanocrystals,uric acid,electrochemical detection
更新于2025-09-23 15:22:29
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Optimization of Parameters for Quantitative Analysis of <sup>123</sup> I-ioflupane SPECT Images for Monitoring of Progression of Parkinson's Disease
摘要： Objectives: Quantitative assessment of dopamine transporter (DAT) imaging can aid in diagnosing Parkinson’s disease (PD) and assessing disease progression in the context of therapeutic trials. Previously, the software program SBRquant was applied to 123I-ioflupane SPECT images acquired on healthy controls and subjects with PD. Earlier work on optimization of the parameters for differentiating between controls and subjects with dopaminergic deficits is extended here for maximizing change measurements associated with disease progression on longitudinally acquired scans. Methods: Serial 123I-ioflupane SPECT imaging for 51 subjects with PD (conducted approximately 1 year apart) were downloaded from the Parkinson’s Progression Markers Initiative database. The software program SBRquant calculates the Striatal Binding Ratio (SBR) separately for the left and right caudate and putamen regions of interest (ROI). Parameters were varied to evaluate the number of summed transverse slices and the positioning of the striatal ROIs for determining signal to noise associated with their annual rate of change in SBR. The parameters yielding the largest change of the lowest putamen's SBR from scan 1 to scan 2 were determined. Results: For the change from scan 1 to scan 2 in the 51 subjects, the largest annual change was observed when the putamen ROI was placed 3 pixels away from the caudate and by summing 5 central striatal slices. This resulted in an 11.2 ± 4.3% annual decrease in the lowest putamen's SBR for the group. Conclusions: Quantitative assessment of DAT imaging for assessing progression of PD requires specific, optimal parameters different than those for diagnostic accuracy.
关键词： Parkinson's Disease,Dopamine Transporter Imaging,Disease Progression,Quantitative Analysis,123I-ioflupane SPECT
更新于2025-09-23 15:21:21