Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 122
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Chaos ; 33(3): 033137, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37003825

RESUMO

We study a way to set the natural frequency of a newly added oscillator in a growing network to enhance synchronization. Population growth is one of the typical features of many oscillator systems for which synchronization is required to perform their functions properly. Despite this significance, little has been known about synchronization in growing systems. We suggest effective growing schemes to enhance synchronization as the network grows under a predetermined rule. Specifically, we find that a method based on a link-wise order parameter outperforms that based on the conventional global order parameter. With simple solvable examples, we verify that the results coincide with intuitive expectations. The numerical results demonstrate that the approximate optimal values from the suggested method show a larger synchronization enhancement in comparison with other naïve strategies. The results also show that our proposed approach outperforms others over a wide range of coupling strengths.

2.
Chaos ; 31(12): 123127, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34972349

RESUMO

Complex network analyses have provided clues to improve power-grid stability with the help of numerical models. The high computational cost of numerical simulations, however, has inhibited the approach, especially when it deals with the dynamic properties of power grids such as frequency synchronization. In this study, we investigate machine learning techniques to estimate the stability of power-grid synchronization. We test three different machine learning algorithms-random forest, support vector machine, and artificial neural network-training them with two different types of synthetic power grids consisting of homogeneous and heterogeneous input-power distribution, respectively. We find that the three machine learning models better predict the synchronization stability of power-grid nodes when they are trained with the heterogeneous input-power distribution rather than the homogeneous one. With the real-world power grids of Great Britain, Spain, France, and Germany, we also demonstrate that the machine learning algorithms trained on synthetic power grids are transferable to the stability prediction of the real-world power grids, which implies the prospective applicability of machine learning techniques on power-grid studies.

3.
J Neurol Neurosurg Psychiatry ; 90(1): 30-37, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30361296

RESUMO

OBJECTIVE: In this multicentre open-label trial, we compared behavioural and neuropsychiatric symptoms in Parkinson's disease (PD) patients with impulse control disorders (ICD) treated with dopamine agonists before and 12 weeks after substituting dopamine agonists with an equivalent dose of levodopa/carbidopa slow-release formulation. METHODS: Baseline characteristics of 50 PD patients with ICD were compared with those of 60 medicated and 40 drug-naive PD control groups. Neuropsychiatric trait changes in the PD-ICD group were investigated 12 weeks after the intervention. ICD behaviours were assessed via modified Minnesota Impulsive Disorders Interview (mMIDI), whereas parkinsonian severity and neuropsychiatric characters were systematically assessed with the Unified PD Rating Scale (UPDRS) and a predefined neuropsychological assessment battery. RESULTS: At baseline, ICD patients showed higher scores in the Neuropsychiatric Inventory and anxiety, anger and obsessive-compulsive traits compared with both PD control groups. In contrast, the three PD groups showed indifference in the impulsivity scales. At 12 weeks post intervention, ICD behaviours significantly improved (p<0.001, Δ modified MIDI score=‒5.27 ± 5.75) along with the UPDRS II daily activity scores (p=0.02, Δ=‒2.07 ± 4.53). Behavioural disinhibition tended to improve (p=0.06), although no significant changes were observed in the Neuropsychiatric Inventory and personality trait scores. Dopamine agonist withdrawal syndrome developed in 5.3% of the PD-ICD group. CONCLUSIONS: This study provides class IV evidence suggesting that switching from dopamine agonists to levodopa/carbidopa slow-release formulations alleviated ICD behaviours in PD patients leading to improvement in daily activities whereas neuropsychiatric traits associated with ICD persisted after the 12-week therapy. TRIAL REGISTRATION NUMBER: NCT01683253.


Assuntos
Antiparkinsonianos/uso terapêutico , Carbidopa/uso terapêutico , Transtornos Disruptivos, de Controle do Impulso e da Conduta/tratamento farmacológico , Agonistas de Dopamina/uso terapêutico , Levodopa/uso terapêutico , Doença de Parkinson/tratamento farmacológico , Adulto , Idoso , Idoso de 80 Anos ou mais , Transtornos Disruptivos, de Controle do Impulso e da Conduta/etiologia , Transtornos Disruptivos, de Controle do Impulso e da Conduta/psicologia , Combinação de Medicamentos , Substituição de Medicamentos , Feminino , Humanos , Indóis/uso terapêutico , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Doença de Parkinson/psicologia , Pramipexol/uso terapêutico
4.
Chaos ; 29(10): 103132, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31675814

RESUMO

In electric power systems delivering alternating current, it is essential to maintain its synchrony of the phase with the rated frequency. The synchronization stability that quantifies how well the power-grid system recovers its synchrony against perturbation depends on various factors. As an intrinsic factor that we can design and control, the transmission capacity of the power grid affects the synchronization stability. Therefore, the transition pattern of the synchronization stability with the different levels of transmission capacity against external perturbation provides the stereoscopic perspective to understand the synchronization behavior of power grids. In this study, we extensively investigate the factors affecting the synchronization stability transition by using the concept of basin stability as a function of the transmission capacity. For a systematic approach, we introduce the integrated basin instability, which literally adds up the instability values as the transmission capacity increases. We first take simple 5-node motifs as a case study of building blocks of power grids, and a more realistic IEEE 24-bus model to highlight the complexity of decisive factors. We find that both structural properties such as gate keepers in network topology and dynamical properties such as large power input/output at nodes cause synchronization instability. The results suggest that evenly distributed power generation and avoidance of bottlenecks can improve the overall synchronization stability of power-grid systems.

5.
Nature ; 490(7419): 235-9, 2012 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-23034653

RESUMO

Grain boundaries in graphene are formed by the joining of islands during the initial growth stage, and these boundaries govern transport properties and related device performance. Although information on the atomic rearrangement at graphene grain boundaries can be obtained using transmission electron microscopy and scanning tunnelling microscopy, large-scale information regarding the distribution of graphene grain boundaries is not easily accessible. Here we use optical microscopy to observe the grain boundaries of large-area graphene (grown on copper foil) directly, without transfer of the graphene. This imaging technique was realized by selectively oxidizing the underlying copper foil through graphene grain boundaries functionalized with O and OH radicals generated by ultraviolet irradiation under moisture-rich ambient conditions: selective diffusion of oxygen radicals through OH-functionalized defect sites was demonstrated by density functional calculations. The sheet resistance of large-area graphene decreased as the graphene grain sizes increased, but no strong correlation with the grain size of the copper was revealed, in contrast to a previous report. Furthermore, the influence of graphene grain boundaries on crack propagation (initialized by bending) and termination was clearly visualized using our technique. Our approach can be used as a simple protocol for evaluating the grain boundaries of other two-dimensional layered structures, such as boron nitride and exfoliated clays.

6.
Neurodegener Dis ; 17(1): 31-37, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-27614955

RESUMO

AIMS: To elucidate different patterns of progression of midbrain atrophy in patients with Richardson's syndrome (RS), progressive supranuclear palsy-parkinsonism (PSP-P), and Parkinson's disease (PD) using magnetic resonance imaging (MRI)-based visual rating indexes. METHODS: We recruited 12 patients with PSP-RS, 12 with PSP-P, and 23 with PD for whom MRIs had been followed up for at least 2 years (mean ± SD, 4.9 ± 1.6 years) after the initial MRI. MRI-based visual rating indexes were used to estimate midbrain atrophy, including the ratio of the pontine to midbrain tegmental areas (P/M ratio) on a midsagittal image, the length between the interpeduncular fossa and the center of the cerebral aqueduct at the midmammillary-body level (MTEGM) on axial images, and the morning glory sign. RESULTS: Initially, there were no differences in MRI-based visual rating indexes between PSP-P and PD, while PSP-RS showed a higher P/M ratio and lower MTEGM compared with PSP-P and PD. In PD, the P/M ratio and MTEGM remained stable with disease progression. However, the extent of changes between initial and follow-up indexes was similarly greater for both PSP-RS and PSP-P than for PD. Finally, PSP-P showed a higher P/M ratio and lower MTEGM compared with PD in the follow-up, while PSP-RS still exhibited the most profound changes. CONCLUSIONS: Midbrain atrophy progresses differentially in patients with PSP-RS, PSP-P, and PD. Longitudinal measurements of midbrain atrophy using MRI-based visual rating indexes can help distinguish patients with PSP-P from those with PSP-RS and PD.


Assuntos
Mesencéfalo/diagnóstico por imagem , Transtornos Parkinsonianos/diagnóstico por imagem , Paralisia Supranuclear Progressiva/diagnóstico por imagem , Idoso , Atrofia , Diagnóstico Diferencial , Progressão da Doença , Feminino , Seguimentos , Humanos , Estudos Longitudinais , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Índice de Gravidade de Doença
7.
J Clin Ultrasound ; 45(6): 337-342, 2017 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-28401995

RESUMO

OBJECTIVES: Orthostatic hypotension (OH) is controversially regarded as the cause of orthostatic dizziness in Parkinson's disease (PD). We sought to evaluate whether cerebral autoregulation is an alternative cause for orthostatic dizziness in PD patients, using transcranial Doppler monitoring during head-up tilting. METHODS: Forty-five PD patients with dizziness, 13 PD patients without dizziness, and 10 age-matched healthy controls were enrolled. Participants were divided into the following four groups: patients with dizziness and OH (group 1, n = 22), patients with dizziness but no OH (n = 23, group 2), patients without dizziness (n = 11, group 3), and age-matched healthy controls (n = 10, group 4). All participants underwent transcranial Doppler and blood pressure monitoring for 10 minutes during the head-up tilt test. Changes in the cerebral blood flow velocity (CBFV) in the middle cerebral artery and the mean blood pressure (mBP) within 3 minutes after head-up tilting were compared between groups. RESULTS: Group 1 showed a significantly higher change in mBP (-16.3 ± 10.8 mmHg) than groups 2 (-2.6 ± 4.9), 3 (-2.2 ± 3.6), or 4 (1.8 ± 6.0) (p < 0.001). However, groups 3 (4.6 ± 3.0 cm/s) and 4 (-4.2 ± 2.5) showed a significantly smaller change in CBFV than groups 1 (-9.0 ± 4.2) and 2 (-8.1 ± 5.1) (p < 0.01). CONCLUSIONS: Our results suggest that cerebral hypoperfusion contributes to dizziness in PD patients despite a lack of OH. Transcranial Doppler monitoring during head-up tilting may be a useful tool for evaluating dizziness in PD patients with or without OH. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 45:337-342, 2017.


Assuntos
Circulação Cerebrovascular/fisiologia , Tontura/fisiopatologia , Artéria Cerebral Média/fisiopatologia , Doença de Parkinson/fisiopatologia , Ultrassonografia Doppler Transcraniana/métodos , Idoso , Pressão Sanguínea/fisiologia , Estudos Transversais , Feminino , Homeostase/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Artéria Cerebral Média/diagnóstico por imagem , Estudos Retrospectivos , Teste da Mesa Inclinada
8.
Can J Neurol Sci ; 43(3): 390-7, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26853109

RESUMO

BACKGROUND: Patients diagnosed with Parkinson's disease (PD) on clinics who subsequently turn out to have normal dopamine transporter images have been referred to as scans without evidence of dopaminergic deficits (SWEDDs) patients. Cardiovascular autonomic dysfunction has frequently been reported in PD. In this study, we determined the similarities and differences in cardiac autonomic dysfunction between SWEDDs and PD patients. This study investigated whether 24-hour ambulatory blood pressure monitoring (24-hour ABPM) can help identify possible cases with SWEDDs. METHODS: We enrolled 28 SWEDDs patients, 46 patients with PD, and 30 healthy controls. To evaluate cardiac autonomic function, 24-hour ABPM was performed on all subjects. Cardiac metaiodobenzylguanidine (MIBG) scintigraphy was performed on the SWEDDs and PD subjects. RESULTS: The percentage nocturnal decline in blood pressure differed significantly among SWEDDs patients, PD patients, and controls (p<0.05). In addition to the abnormal nocturnal BP, regulation (nondipping and reverse dipping) was significantly higher in SWEDDs and PD subjects than in the control subjects (p<0.05). There was no significant correlation between the % nocturnal blood pressure reduction and parameters of cardiac MIBG uptake ratio. However, orthostatic hypotension was significant correlated with the nocturnal blood pressure dip (%), nocturnal blood pressure patterns, and the cardiac MIBG uptake ratio (early and late) in combined SWEDDs and PD subjects. CONCLUSIONS: Pathologic nocturnal blood pressure regulation and nocturnal hypertension, known characteristics of PD, are also present in SWEDDs. Moreover, cardiac sympathetic denervation should not be attributed to cardiac autonomic dysfunction in SWEDDs patients. As with PD patients, the SWEDDs patients studied here tended to have cardiac autonomic dysfunction.


Assuntos
Monitorização Ambulatorial da Pressão Arterial/métodos , Pressão Sanguínea/fisiologia , Dopamina/deficiência , Doença de Parkinson/metabolismo , Doença de Parkinson/fisiopatologia , 3-Iodobenzilguanidina/farmacocinética , Idoso , Proteínas da Membrana Plasmática de Transporte de Dopamina/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/diagnóstico por imagem , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/farmacocinética , Estudos Retrospectivos , Tomógrafos Computadorizados
9.
Neurodegener Dis ; 16(3-4): 199-205, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26735311

RESUMO

BACKGROUND AND OBJECTIVES: Gastrointestinal dysfunction is a common non motor symptom in Parkinson's disease (PD). However, the potential association between vitamin D and gastroparesis in PD has not been previously investigated. The aim of this study was to compare vitamin D levels between drug-naive de novo PD patients with normal gastric emptying and those with delayed gastric emptying. METHODS: Fifty-one patients with drug-naive de novo PD and 20 age-matched healthy controls were enrolled in this study. Gastric emptying time (GET) was assessed by scintigraphy, and gastric emptying half-time (T1/2) was determined. The PD patients were divided into a delayed-GET group and a normal-GET group. RESULTS: The serum 25-hydroxyvitamin D3 levels were decreased in the delayed-GET group compared with the normal-GET and control groups (11.59 ± 4.90 vs. 19.43 ± 6.91 and 32.69 ± 4.93, respectively, p < 0.01). In the multivariate model, the serum 25-hydroxyvitamin D3 level was independently associated with delayed gastric emptying in PD patients. CONCLUSIONS: Vitamin D status may be an independent factor for gastric dysmotility in PD. Although the underlying mechanism remains to be characterized, vitamin D status may play a role in the pathogenesis of delayed gastric emptying in drug-naive PD.


Assuntos
Calcifediol/sangue , Esvaziamento Gástrico/fisiologia , Doença de Parkinson/fisiopatologia , Deficiência de Vitamina D/fisiopatologia , Idoso , Análise Química do Sangue , Estudos Transversais , Feminino , Grelina/sangue , Humanos , Masculino , Entrevista Psiquiátrica Padronizada , Análise Multivariada , Doença de Parkinson/diagnóstico por imagem , Índice de Gravidade de Doença , Fatores de Tempo , Deficiência de Vitamina D/diagnóstico por imagem
10.
Mov Disord ; 30(2): 206-13, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25476727

RESUMO

We aimed to compare Dysport (abobotulinumtoxinA, Ipsen Biopharm, Slough, UK) and Botox (onabotulinumtoxinA, Allergan, Irvine, CA, USA) at a 2.5:1 ratio in the treatment of cervical dystonia (CD). A Dysport/Botox ratio of lower than 3:1 was suggested as a more appropriate conversion ratio, considering its higher efficacy and more frequent incidence of adverse effects not only in the treatment of CD but also in other focal movement disorders. A randomized, double-blind, multicenter, non-inferiority, two-period crossover study was done in CD, with a duration of at least 18 months. Patients were randomly assigned to treatment for the first period with Dysport or Botox, and they were followed up for 16 weeks after the injection. After a 4-week washout period, they were switched to the other formulation and then followed up for 16 weeks. The primary outcome was the changes in the Tsui scale between the baseline value and that at 1 month after each injection. A total of 103 patients were enrolled, and 94 completed the study. Mean changes in the Tsui scale between baseline and 4 weeks after each injection tended to favor Botox; however, this was not statistically significant (4.0 ± 3.9 points for the Dysport treatment vs. 4.8 ± 4.1 points for Botox; 95% confidence interval, -0.1-1.7; P = 0.091). The mean change of the Toronto western spasmodic torticollis rating scale score, the proportion of improvement in clinical global impression and patient global impression, and the incidences of adverse events were not significantly different between the two treatments. With regard to safety and efficacy, Dysport was not inferior to Botox in patients with CD at a conversion factor of 2.5:1. [clinicaltrial.gov: NCT00950664]


Assuntos
Inibidores da Liberação da Acetilcolina/uso terapêutico , Toxinas Botulínicas Tipo A/uso terapêutico , Torcicolo/tratamento farmacológico , Adulto , Idoso , Método Duplo-Cego , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Dor/etiologia , Medição da Dor , Torcicolo/complicações , Resultado do Tratamento , Adulto Jovem
11.
Nanotechnology ; 25(22): 225301, 2014 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-24833169

RESUMO

Silica nanostructures were fabricated on glass substrate using a microwave assisted direct patterning (MADP) process, which is a variety of soft lithography. During the MADP process using polydimethylsiloxane (PDMS), mold and microwave heating are performed simultaneously. Blanket thin film and micro- to nano-sized structures, including moth-eye patterns of SiO2, which consisted of coalesced silica nanoparticles, were formed on glass substrates from SiO2 nano-particle dispersed solutions with varied microwave heating time. Optical properties and surface morphologies of micro-sized hemisphere, nano-sized pillar, moth-eye and 50 nm sized line/space silica patterns were measured using UV-vis and a scanning electron microscope. X-ray diffraction analysis of SiO2 thin films with and without microwave heating was also carried out.

12.
Nanomaterials (Basel) ; 14(4)2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38392707

RESUMO

Ferromagnetic materials have been attracting great interest in the last two decades due to their application in spintronics devices. One of the hot research areas in magnetism is currently the two-dimensional materials, transition metal dichalcogenides (TMDCs), which have unique physical properties. The origins and mechanisms of transition metal dichalcogenides (TMDCs), especially the correlation between magnetism and defects, have been studied recently. We investigate the changes in magnetic properties with a variation in annealing temperature for the nanoscale compound MoS2. The pristine MoS2 exhibits diamagnetic properties from low-to-room temperature. However, MoS2 compounds annealed at different temperatures showed that the controllable magnetism and the strongest ferromagnetic results were obtained for the 700 °C-annealed sample. These magnetizations are attributed to the unpaired electrons of vacancy defects that are induced by annealing, which are confirmed using Raman spectroscopy and electron paramagnetic resonance spectroscopy (EPR).

13.
J Clin Neurol ; 20(5): 487-492, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39227331

RESUMO

BACKGROUND AND PURPOSE: The wearing-off (WO) phenomenon is the most common motor complication in advanced Parkinson's disease (PD), but its identification remains challenging. The 9- and 19-item Wearing-off Questionnaires (WOQ-9 and WOQ-19) are self-assessment tools for motor and nonmotor symptoms that are widely used for WO screening. We produced Korean versions of the WOQ-19 and WOQ-9 (K-WOQ-19 and K-WOQ-9) and investigated their validity and reliability. METHODS: We used the translation-back translation method to produce K-WOQ-19 and K-WOQ-9, which were self-administered by 124 patients with PD. We conducted in-depth 10-minute interviews for confirming the presence of the WO phenomenon, and then stratified the participants into groups with and without WO. Diagnostic accuracy was assessed byanalyzing receiver operating characteristic curves. Concurrent validity was assessed using the Movement Disorder Society-Unified Parkinson's Disease Rating Scale (MDS-UPDRS) andthe Hoehn and Yahr stage with Spearman's rank correlation analysis. Reliability was assessedbased on test-retest Cohen's kappa (κ) values and intraclass correlation coefficients (ICCs). RESULTS: The optimal cutoff scores on the K-WOQ-19 and K-WOQ-9 for WO screening were 4 and 2, respectively. The test-retest ICCs of K-WOQ-19 and K-WOQ-9 were 0.943 and 0.938, respectively. Nineteen of the combined 20 items in K-WOQ-19 and K-WOQ-9 showed moderate-to-substantial agreement (κ=0.412-0.771, p<0.001). The scores on the translated scales were significantly correlated with MDS-UPDRS IV scores. CONCLUSIONS: K-WOQ-19 and K-WOQ-9 are reliable and valid tools for detecting WO, with optimal cutoff scores of 4 and 2, respectively.

14.
ACS Appl Mater Interfaces ; 16(28): 36204-36214, 2024 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-38973635

RESUMO

Although the Li metal has been gaining attention as a promising anode material for the next-generation high-energy-density rechargeable batteries owing to its high theoretical specific capacity (3860 mAh g-1), its practical use remains challenging owing to inherent issues related to Li nucleation and growth. This paper reports the fabrication of a lithiophilic multichannel layer (LML) that enables the simultaneous control of Li nucleation and growth in Li-metal batteries. The LML, composed of lithiophilic ceramic composite nanoparticles (Ag-plated Al2O3 particles), is fabricated using the electroless plating method. This LML provides numerous channels for a uniform Li-ion diffusion on a nonwoven separator. Furthermore, the lithiophilic Ag on the Li metal anode surface facing the LML induces a low overpotential during Li nucleation, resulting in a dense Li deposition. The LML enables the LiNi0.8Co0.1Mn0.1O2|| Li cells to maintain a capacity higher than 75% after 100 cycles, even at high charge/discharge rates of 5.0 C at a cutoff voltage of 4.4 V, and achieve an ultrahigh energy density of 1164 Wh kg-1. These results demonstrate that the LML is a promising solution enabling the application of Li metal as an anode material in the next-generation Li-ion batteries.

15.
Anim Cells Syst (Seoul) ; 28(1): 428-438, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39246418

RESUMO

Burn injuries, affecting local skin disruption as well as inducing systemic inflammatory responses, are presented as a global public health problem. To enhance the effects of burn wound healing, treatment must simultaneously regulate both re-epithelialization and hyperinflammation. Extracts of Sargassum horneri (S. horneri) have shown a potential to enhance skin wound healing through antioxidative properties, immune enhancement, and modulation of inflammatory responses. However, despite its promising application for burn wound healing, specific investigation into S. horneri-derived compounds for enhancing wound healing has not yet been conducted. In this research, we investigated the burn wound-healing effect of the low-temperature pulverization-specific S. horneri extract (LPSHE), which could not be detected using the room-temperature grinding method. In a mouse burn model with third-degree burn injuries, LPSHE accelerated re-epithelialization by promoting the increase in F-actin formation and reduced burn-induced ROS levels. Additionally, LPSHE significantly regulated hyperinflammation by reducing pro-inflammatory cytokines. Further investigation into molecular mechanisms using HaCaT keratinocytes also demonstrated beneficial effects on burn wound healing. Taken together, our findings suggested that LPSHE is a promising therapeutic candidate for enhancing burn wound healing. Furthermore, this research underscored the importance of low-temperature pulverization in discovering novel natural compounds from marine organisms.

16.
J Mov Disord ; 17(3): 328-332, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38566308

RESUMO

OBJECTIVE: The Scales for Outcomes in Parkinson's Disease-Cognition (SCOPA-Cog) was developed to assess cognition in patients with Parkinson's disease (PD). In this study, we aimed to evaluate the validity and reliability of the Korean version of the SCOPACog (K-SCOPA-Cog). METHODS: We enrolled 129 PD patients with movement disorders from 31 clinics in South Korea. The original version of the SCOPA-Cog was translated into Korean using the translation-retranslation method. The test-retest method with an intraclass correlation coefficient (ICC) and Cronbach's alpha coefficient were used to assess reliability. Spearman's rank correlation analysis with the Montreal Cognitive Assessment-Korean version (MOCA-K) and the Korean Mini-Mental State Examination (K-MMSE) were used to assess concurrent validity. RESULTS: The Cronbach's alpha coefficient was 0.797, and the ICC was 0.887. Spearman's rank correlation analysis revealed a significant correlation with the K-MMSE and MOCA-K scores (r = 0.546 and r = 0.683, respectively). CONCLUSION: Our. RESULTS: demonstrate that the K-SCOPA-Cog has good reliability and validity.

17.
Clin Auton Res ; 23(4): 221-4, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23843160

RESUMO

In our work, we investigated thyroid and cardiac MIBG uptake as potential differential markers. We observed reduced cardiac uptake of MIBG in PD and diabetic CAN, in agreement with the previous studies. However, there was a significant difference between the PD and diabetic cardiac autonomic neuropathy groups with respect to early and delayed thyroid MIBG uptake, in that reduced thyroid MIBG uptake was seen in PD but not in diabetic autonomic neuropathy. We therefore propose that this parameter could be a marker for identifying parkinsonism when it presents together with DM.


Assuntos
3-Iodobenzilguanidina/farmacocinética , Complicações do Diabetes/diagnóstico por imagem , Doença de Parkinson/diagnóstico por imagem , Compostos Radiofarmacêuticos/farmacocinética , Glândula Tireoide/diagnóstico por imagem , Glândula Tireoide/metabolismo , Idoso , Neuropatias Diabéticas/diagnóstico por imagem , Neuropatias Diabéticas/metabolismo , Feminino , Coração/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Miocárdio/metabolismo , Doença de Parkinson/complicações , Tomografia por Emissão de Pósitrons
18.
Neurol Sci ; 34(1): 75-8, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22198649

RESUMO

Cognitive deficits may contribute to falls in Parkinson's disease (PD) and these deficits may be risk factors for falls. However, their association with falls has been generally studied in patients with continuous gait problems. There have been few studies in PD patients without postural instability. In addition, the effectiveness of various simple bedside cognitive tests in predicting falls has not been established. In this study, we investigated the effectiveness of three bedside cognitive tests in consecutive patients with PD without postural instability. Of the 119 patients, 39 experienced falls during the follow-up period. Of the bedside cognitive assessment methods examined, only the Montreal Cognitive Assessment (MoCA) score was significantly lower in the group of fallers than in the group of non-fallers. This result suggests that the MoCA is effective as a bedside test for evaluating the risk of falls.


Assuntos
Acidentes por Quedas , Testes Neuropsicológicos , Doença de Parkinson/psicologia , Sistemas Automatizados de Assistência Junto ao Leito , Idoso , Idoso de 80 Anos ou mais , Antiparkinsonianos/efeitos adversos , Antiparkinsonianos/uso terapêutico , Cognição , Interpretação Estatística de Dados , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Doença de Parkinson/complicações , Estudos Prospectivos , Escalas de Graduação Psiquiátrica , Risco
19.
Neurol Sci ; 34(8): 1375-82, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23179185

RESUMO

Dopamine transporter scans of some patients who have been clinically diagnosed with Parkinson's disease (PD) fail to reveal abnormal dopaminergic functioning and are referred to as scans without evidence of dopaminergic deficits (SWEDDs). In this study, we investigated the differences between SWEDDs patients and PD patients using (123)I-metaiodobenzylguanidine (MIBG) scans. This study enrolled 20 patients with SWEDDs, 30 patients with early PD and 50 healthy controls. Cardiac (123)I-MIBG scans were performed on all subjects, and parameters including the early and delayed heart-to-mediastinum ratios (H/M) and the washout rate were compared among the three groups. The mean delayed H/M ratio in the PD group (mean ± standard deviation, 1.45 ± 0.23) was the lowest of the three groups, and the scans in the group without evidence of dopaminergic deficits exhibited a lower mean delayed H/M ratio (2.15 ± 0.48) than the control group (2.56 ± 0.55) (p < 0.05). The intermediate status of cardiac MIBG uptake in the SWEDDs patients in our study may have been due to the heterogeneity of the SWEDDs patients; some of these patients had Parkinsonism with unknown characteristics, some may have had early PD with false-negative dopamine transporter imaging, and some have had primary dystonia that was misdiagnosed as PD. These uncharacterised SWEDDs patients accounted for a larger proportion of the heterogeneous SWEDDs than observed in previous studies, but our results suggest that cardiac (123)I-MIBG scans may help to differentiate patients with SWEDDs from patients with PD.


Assuntos
Proteínas da Membrana Plasmática de Transporte de Dopamina/análise , Coração/inervação , Doença de Parkinson/diagnóstico por imagem , Sistema Nervoso Simpático/patologia , 3-Iodobenzilguanidina/administração & dosagem , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/administração & dosagem
20.
Polymers (Basel) ; 15(6)2023 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-36987184

RESUMO

With the International Maritime Organization (IMO) reinforcing environmental regulations on the shipbuilding industry, the demand for fuels, such as liquefied natural gas (LNG) and liquefied petroleum gas (LPG), has soared. Therefore, the demand for a Liquefied Gas Carrier for such LNG and LPG also increases. Recently, CCS carrier volume has been increasing, and damage to the lower CCS panel has occurred. To withstand liquefied gas loads, the CCSs should be fabricated using a material with improved mechanical strength and thermal performance compared with the conventional material. This study proposes a polyvinyl chloride (PVC)-type foam as an alternative to commercial polyurethane foam (PUF). The former material functions as both insulation and a support structure primarily for the LNG-carrier CCS. To investigate the effectiveness of the PVC-type foam for a low-temperature liquefied gas storage system, various cryogenic tests, namely tensile, compressive, impact, and thermal conductivity, are conducted. The results illustrate that the PVC-type foam proves stronger than PUF in mechanical performance (compressive, impact) across all temperatures. In the tensile test, there are reductions in strength with PVC-type foam but it meets CCS requirements. Therefore, it can serve as insulation and improve the overall CCS mechanical strength against increased loads under cryogenic temperatures. Additionally, PVC-type foam can serve as an alternative to other materials in various cryogenic applications.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA